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Huenemoerder, David, K. Gayley, Wolf-Rainer Hamann, Richard Ignace, J. Nichols, Lidia M. Oskinova, A. M. T. Pollock, and N. Schulz. "High Resolution X-ray Spec- tra of WR 6." Digital Commons @ East Tennessee State University, 2015. https://dc.etsu.edu/etsu-works/2699.
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As WR 6 is a putatively single WN4 star, and is relatively bright (V = 6.9), it is an ideal case for studying the wind mechanisms in these extremely luminous stars. To obtain higher resolution spectra at higher energy (above 1 keV) than previously obtained with the XMM/Newton RGS, we have observed WR 6 with the Chandra High Energy Transmission Grating Spectrometer for 450 ks. We have resolved emission lines of S, Si, Mg, Ne, and Fe, which all show a “fin”-shaped profile, characteristic of a self-absorbed uniformly expanding shell. Steep blue edges gives robust maximal expansion velocities of about 2000 km/s, somewhat larger than the 1700 km/s derived from UV lines. The He-like lines all indicate that X-ray emitting plasmas are far from the photosphere – even at the higher energies where opacity is lowest – as was also the case for the longer wavelength lines observed with XMM-Newton/RGS. Abundances determined from X-ray spectral modeling indicate enhancements consistent with nucleosynthesis. The star was also variable in X-rays and in simultaneous optical photometry obtained with Chandra aspect camera, but not coherently with the optically known period of 3.765 days.
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Langan, Sinéad. "A prospective study of the effects of environmental factors on eczema in children." Thesis, University of Nottingham, 2008. http://eprints.nottingham.ac.uk/11775/.
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Background: Eczema is an important condition as it affects 20% of children in the UK and is associated with significant morbidity for children and their families. Although some progress in understanding factors associated with the occurrence of eczema has been made, very little is known about factors associated with disease worsening. Most textbooks and review articles quote long lists of exacerbating factors but with very little scientific data to support them. Before I could begin to study this topic, I first had to define a disease flare in eczema, systematically review the literature on flare factors in eczema and review available outcome measures for eczema. Objectives: The objectives of the main study described in this thesis were to assess the role of various environmental factors on the severity of eczema in a cohort of children with eczema. Hypotheses: 1. In hot weather, the combination of heat, sweating and grass pollen precipitates increased severity in children with eczema in the UK. 2. In cold weather, the combination of cold weather, indoor aeroallergen exposure and reduced relative humidity from central heating lead to increased severity in children with eczema in the UK. These first two hypotheses were informed by previous research which proposed "summer" and "winter" types of eczema. 3. Detergents (soap, shampoo) increase the propensity to disease flares triggered by other factors at all temperatures, but more in cold weather due to impaired skin barrier function. 4. UK children with filaggrin mutations are more prone to the effects of climatic factors such as cold and heat than individuals who are wild type for filaggrin. 5. Any combination of greater than or equal to three exposures at any time is associated with worsening of eczema. The exposures assessed included: dust, exposure to pets, shampoo, sweating, swimming, nylon clothing next to the skin and a change in mean temperature of more than 3°C from the previous weekly average. Methods: Pilot study: 30 children with moderate to severe eczema aged 0 to 15 years participated in a panel study over a one month period in June 2003 in Cork, Ireland. This study involved daily completion of a paper diary recording eczema severity and exposures. Feasibility of a panel study design was assessed and associations between exposures and disease severity were analysed. Main study: A prospective cohort study (n=60) of children aged up to 15 years with moderate to severe eczema was studied for between six and nine months with overlapping start dates to allow study of seasonal factors. Exposures studied included: temperature, relative humidity, sun exposure, sweating, clothing, cleansing products/ washing, outdoor pollen level, extent and nature of exposure to household pets, dusty environments and swimming. Children or their parents completed daily novel electronic diaries recording eczema severity and exposures. Portable dataloggers were used to record indoor temperature and relative humidity. External meteorological data was obtained from a local monitoring centre. The primary outcome was a daily "bother" score and the secondary outcomes were daily "scratch" scores and flares of eczema. Autoregressive moving average models (ARMA) were used to model the impact of each exposure on eczema severity for each individual. Standard random effects meta-analysis techniques were used to pool estimated coefficients across participants. Heterogeneity of responses as detected using Chi-squared tests represented inter-individual variation. The body site-specificity of reactions was also examined as was the interaction between filaggrin mutations and disease worsening with exposures. Findings. Pilot study: The pilot study highlighted the issue of drop outs and missing data during the study. 83% (n=25) returned the diaries at the end of the study period, and within these, recording of disease severity was good (97% complete). However, there was variability in recording of exposures (65% to 83% complete). Preliminary findings suggested a temporal association between eczema severity and heat (lag 0, i.e. the day of exposure, p=0.04), damp (lag day 2, p=0.03), sweating and stress (lag day 3, p=0.03 and p=0.02 respectively) and damp (lag day 4, p=0.001). Main study: Primary outcome: "bother scores": Increased disease severity was associated with direct contact with nylon clothing (pooled regression coefficient 0.23, 95% CI 0.03 to 0.43), increasing exposure to dust (pooled regression coefficient 0.53, 0.23 to 0.83), exposure to unfamiliar pets (pooled regression coefficient 0.22, 0.10 to 0.34), sweating (pooled regression coefficient 0.24, 0.09 to 0.39) and shampoo exposure (pooled regression coefficient 0.07, 0.01 to 0.13). The association between shampoo use and worsening of eczema was enhanced in cold weather (pooled regression coefficient 0.30, 0.04 to 0.57). Body site specificity was observed for the reactions to nylon clothing, which was greater on covered sites (trunk p=0.02, limbs p=0.03), reactions to wool clothing on truncal covered sites (p=0.03) but not limbs (p=0.62), while worsening of hand eczema was associated with exposure to pets (p<0.001). The only interaction with filaggrin mutations was observed for the 2282del4 mutation and worsening of eczema in summer. Significant heterogeneity of responses between individuals was observed for exposure to grass pollen and outdoor temperature. In regard to the final hypothesis, a combination of any three of seven likely variables was associated with worsening of eczema (pooled regression coefficient 0.41, 0.20 to 0.63). Secondary outcome: "scratch" scores: Increased disease severity was seen associated with swimming (pooled regression coefficient 0.14,0.00 to 0.28), exposure to wool clothing (pooled regression coefficient 0.28, 0.11 to 0.45), sweating (pooled regression coefficient 0.15, 0.04 to 0.26), shampoo (pooled regression coefficient 0.07, 0.01 to 0.13), dust (pooled regression coefficient 0.36, 0.12 to 0.59) and high grass pollen levels (pooled regression coefficient 0.10, 0.01 to 0.73). Secondary outcome: flares of eczema: Only swimming was clearly associated with worsening of eczema using this outcome measure (pooled regression coefficient 0.42, 0.05 to 0.80). Conclusions: The following factors were shown to be associated with disease worsening in children with eczema in this UK study: clothing (wool and nylon), sweating, shampoo, swimming, dust, contact with unfamiliar pets and high grass pollen levels. Relative to the study hypotheses, the association between shampoo exposure and eczema worsening was shown to be increased in cold weather. There was also evidence showing an association between various combinations of exposures and disease worsening. There was insufficient evidence to support the other hypotheses tested in this study but this may be explained by low prevalence of these exposures. The implications of the findings of this study for clinical practice are that for the first time, it has been shown that shampoo exposure may be associated with eczema worsening and that this is more pronounced in cold weather. This study also suggests that worsening of eczema may be more complicated in that multiple exposures acting in concert may be associated with worsening of disease. Future research with increased participant numbers is required to specifically study possible gene-environment interactions with filaggrin mutations and their relevance in relation to disease flares and to look at shampoo formulations in relation to worsening of eczema.
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Eleftheriadou, Viktoria. "Setting priorities and reducing uncertainties for the treatment of vitiligo." Thesis, University of Nottingham, 2013. http://eprints.nottingham.ac.uk/13378/.
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Vitiligo is the most common skin disorder resulting in depigmentation, but high-quality research is lacking. A Cochrane review of interventions for vitiligo published in 2010 highlighted methodological limitations with existing trials; which have generally been too small and heterogeneous to inform clinical recommendations. The objective of this thesis was to improve the evidence base for the treatment of vitiligo. This PhD was funded by the National Institute for Health Research, as part of the research programme called “Setting Priorities and Reducing Uncertainties for people with Skin Diseases”. It includes the following: 1) identifying the most important research priorities for patients and clinicians, thereby informing the research agenda; 2) conducting a systematic review of outcome measures used in vitiligo trials and a survey of the most desirable outcomes for patients and clinicians; and 3) conducting a pilot double blind, randomised controlled trial (RCT) on home hand-held phototherapy in preparation of the first national multi-centre RCT for the treatment of vitiligo. For the prioritisation exercise, a total of 660 treatment uncertainties were submitted by 460 patients and clinicians. The identified priority areas included interventions such as combination of topical agents and phototherapy. The systematic review on outcome measures identified 25 different domains that had been used in previous trials. Although percentage repigmentation was measured in 96%; 48 different scales had been used. In contrast, patients and clinicians favoured the use of “cosmetically acceptable” repigmentation. Finally, a 4-month pilot trial recruited 29 participants and tested the logistics of running a future RCT. This work resulted in a commissioned call and funding of a national RCT on vitiligo (topical corticosteroids in combination with home hand-held phototherapy); the initiation of an international consensus exercise on core outcome measures for use in vitiligo trials; and informed the design and conduct of a future national RCT.
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Simpson, Rosalind C. "Erosive lichen planus affecting the vulva : defining the disease, developing outcome measures and designing a randomised controlled trial." Thesis, University of Nottingham, 2015. http://eprints.nottingham.ac.uk/28301/.
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Erosive lichen planus affecting the vulvovaginal region (ELPV) is a rare chronic inflammatory condition causing painful raw areas that can lead to scarring, at the vaginal entrance. Symptoms considerably impact upon daily function and quality of life. There is risk of cancerous change in affected skin of 1-3%. A Cochrane Systematic Review, published in 2012, found no randomised controlled trials (RCT) on which to base treatment for ELPV. Retrospective case series suggest that super-potent topical corticosteroids are frequently used as first-line therapy, although one third of patients fail to respond adequately and require escalation of therapy. There is clinical uncertainty regarding which second-line therapies should be used. The following steps were taken to inform the design of an RCT to determine optimal second-line therapy for EVLP resistant to topical steroids: • A multi-centre retrospective review and audit of case notes to assess current clinical management in the UK. • A qualitative investigation with UK clinicians to establish their views and principles of management of ELPV. • An international multi-disciplinary electronic-delphi consensus exercise to agree a set of diagnostic criteria for ELPV. • A systematic review to assess existing outcome measure tools that have been used in randomised controlled trials of vulval skin disorders. • Assessment of patients views through a survey of a national patient group and subsequent focus groups with patients. The resulting multi-centre, four-armed, open-label, pragmatic randomised controlled trial will compare hydroxychloroquine, methotrexate and mycophenolate mofetil against a standard care group of clobetasol propionate 0.05% plus a short course of oral prednisolone. This will be the first RCT to test systemic agents for patients with ELPV and will add to the existing evidence base. The methodologies employed to develop the RCT protocol, and the trial design itself, may act as a template for clinical research into the therapeutic management of other rare inflammatory conditions.
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Lansbury, Louise E. "An evidence based approach towards optimising the management of patients with squamous cell carcinoma of the skin." Thesis, University of Nottingham, 2014. http://eprints.nottingham.ac.uk/27747/.
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Cutaneous squamous cell carcinoma (SCC) is a common cancer yet its treatment is under-researched. The objective of this thesis was to develop a proposal for a randomised controlled trial (RCT) to address uncertainties relating to the management of the condition, and to ultimately improve the management of affected patients. Two systematic reviews were initially conducted to appraise the current evidence base for SCC treatments. Only one RCT was eligible for inclusion in the Cochrane systematic review; a small study which found no significant difference in time to recurrence between patients treated with post-operative 13-cis retinoic acid and interferon, and those not receiving adjuvant treatment. Systematic review and meta-analysis of observational studies included 118 studies. Pooled estimates of recurrence were lowest after cryotherapy and curettage and electrodesiccation, although lesions treated by these modalities were mostly small and low-risk. Although pooled recurrence after Mohs surgery appeared lower than after conventional excision or radiotherapy, the differences were not significant with overlapping 95% confidence intervals. For photodynamic therapy, pooled recurrence after apparently successful initial treatment was particularly high (26%). Evidence relating to the effectiveness of topical and systemic treatments was very limited. Estimates of recurrence were used to inform the sample size calculation for the proposed RCT. A survey of healthcare professionals was conducted to establish research priorities and identify clinically important management uncertainties from which initial trial scenarios were formulated. High-risk SCCs were identified as a research priority, with optimal surgical management and the role of adjuvant radiotherapy being key areas of uncertainty. Through multi-disciplinary collaboration, a proposal for a two-stage RCT has been developed; in the first stage, locoregional recurrence after conventional surgery with a controlled excision margin will be compared with Mohs surgery, and in the second stage locoregional recurrence will be compared between patients treated with adjuvant radiotherapy versus those receiving no adjuvant treatment. Feasibility work conducted during the development of the trial has involved: a) A retrospective analysis of SCCs treated over twelve-months to determine the number of patients and types of SCCs potentially eligible for recruitment into the proposed trial and to further inform the sample size calculation. Within five years of treatment 6% of 357 patients experienced local recurrence, 3% had regional recurrence and 1.5% died of their SCC. Comparison of the most recent American Joint Cancer Council (AJCC7) and an alternative Brigham and Women’s Hospital (BWH) classification showed that approximately 50% of SCCs were T2 in both schemes and eligible for entry into the first stage of the proposed trial. However, an additional BHW T2b substage better stratified outcomes dependent on the number of risk features, and indicated that 19% of all SCCs would potentially be also eligible for the second stage of the trial. b) A questionnaire and focus group study to assess the acceptability of the RCT and to identify possible barriers to recruitment. Participants had a desire to be better informed about SCC, wanting information relating to the trial to be provided in a variety of formats. 71% of participants were hypothetically willing to be randomised into the surgical stage of the proposed trial but had more concerns about the second stage involving adjuvant radiotherapy. Lack of equipoise and confusion about the concept of randomisation will need to be carefully addressed when presenting the trial to participants. The proposed trial will be the first to directly compare treatments for the types of SCC seen commonly in clinical practice. For the trial to be adequately powered, an estimated 5400 participants will need to be recruited, so a multi-centre, multi-disciplinary approach will be necessary.
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Pon, Carlos (Carlos Roberto) Carleton University Dissertation Engineering Electronics. "Time warping - waveform relaxation (TW - WR) in a distributed simulation environment." Ottawa, 1995.
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Huenemoerder, David P., K. G. Gayley, Wolf-Rainer Hamann, Richard Ignace, J. S. Nichols, Lidia M. Oskinova, A. M. T. Pollock, Nobert S. Schulz, and Tomer Shenar. "Probing Wolf–Rayet Winds: Chandra/HETG X-Ray Spectra of WR 6." Digital Commons @ East Tennessee State University, 2015. https://dc.etsu.edu/etsu-works/2692.
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With a deep Chandra/HETGS exposure of WR 6, we have resolved emission lines whose profiles show that the X-rays originate from a uniformly expanding spherical wind of high X-ray-continuum optical depth. The presence of strong helium-like forbidden lines places the source of X-ray emission at tens to hundreds of stellar radii from the photosphere. Variability was present in X-rays and simultaneous optical photometry, but neither were correlated with the known period of the system or with each other. An enhanced abundance of sodium revealed nuclear-processed material, a quantity related to the evolutionary state of the star. The characterization of the extent and nature of the hot plasma in WR 6 will help to pave the way to a more fundamental theoretical understanding of the winds and evolution of massive stars.
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Ignace, Richard, K. Gayley, W. R. Hamann, D. Huenemoerder, L. Oskinova, A. Pollock, and M. McFall. "The XMM-Newton EPIC X-ray Light Curve Analysis of WR 6." Digital Commons @ East Tennessee State University, 2013. https://dc.etsu.edu/etsu-works/6239.
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We obtained four pointings of over 100 ks each of the well-studied Wolf-Rayet star WR 6 with the XMM-Newton satellite. With a first paper emphasizing the results of spectral analysis, this follow-up highlights the X-ray variability clearly detected in all four pointings. However, phased light curves fail to confirm obvious cyclic behavior on the well-established 3.766 d period widely found at longer wavelengths. The data are of such quality that we were able to conduct a search for "event clustering" in the arrival times of X-ray photons. However, we fail to detect any such clustering. One possibility is that X-rays are generated in a stationary shock structure. In this context we favor a co-rotating interaction region (CIR) and present a phenomenological model for X-rays from a CIR structure. We show that a CIR has the potential to account simultaneously for the X-ray variability and constraints provided by the spectral analysis. Ultimately, the viability of the CIR model will require both intermittent long-term X-ray monitoring of WR 6 and better physical models of CIR X-ray production at large radii in stellar winds.
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Eklund, Gerd. "Vrist - brist - rist : utvecklingen av gammalt uddljudande "wr" i nordiska, särskilt svenska, dialekter /." Uppsala : Dialekt- och folkminnesarkivet, 1991. http://catalogue.bnf.fr/ark:/12148/cb35542109m.
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Akademisk avhandling--Humanistiskt-samhällsvetenskapligt centrum--Uppsala, 1991.Mention parallèle de titre ou de responsabilité : Vrist - brist - rist : development of old initial "wr" in Scandinavian, particularly Swedish, dialects. Résumé en anglais.
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Rocha, Juliana Trevisan da. "Atividade hipolipidêmica do disseleneto de difenila na hiperlipidemia induzida por triton wr-1339 em camundongos." Universidade Federal de Santa Maria, 2009. http://repositorio.ufsm.br/handle/1/11115.
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Coordenação de Aperfeiçoamento de Pessoal de Nível SuperiorIn mammals, the liver plays a central role in whole-body lipid metabolism. Unfortunately, dysregulation of these pathways has been implicated in hyperlipidemias. In recent years, a significant association between the trace element selenium and hypercholesterolaemia in human and animals has been reported. This study was designed to investigate a potential hypolipidaemic effect of diphenyl diselenide ((PhSe)2) in Triton WR-1339-induced hyperlipidaemia in mice. Triton was administered intraperitoneally (400 mg/kg) to overnight-fasted mice to develop acute hyperlipidaemia. (PhSe)2 was administered orally (10 mg/kg) 30 min before Triton. At 24 h after Triton injection, blood samples were collected to measure plasma lipid levels. The hepatic thiobarbituric acid reactive substances and ascorbic acid levels as well as catalase and glutathione peroxidase activity were recorded. (PhSe)2 administration significantly lowered total cholesterol, non-high- density lipoprotein-cholesterol and triglycerides,whilst it increased high-density lipoprotein-cholesterol levels in plasma of hyperlipidaemic mice. Neither oxidative stress nor the antioxidant effect of (PhSe)2 was observed in the mouse liver in this experimental protocol. These findings indicated that (PhSe)2 was able to lower plasma lipid concentrations. Further studies are needed to elucidate the exact mechanism by which (PhSe)2 exerted its hypolipidaemic effect in the management of hyperlipidaemia.
Nos mamíferos, o fígado desempenha um papel extremamente importante na manutenção da homeostase do metabolismo dos lipídios plasmáticos. Entretanto, problemas na regulação desses mecanismos têm sido implicados na ocorrência de dislipidemias (alterações na concentração adequada de lipídios no plasma). Nos últimos anos, tem sido evidenciada a existência de uma relação entre os níveis de selênio (Se) e o aumento nas concentrações plasmáticas de lipídios em humanos e animais. Dessa forma, o presente trabalho teve por objetivo investigar um possível efeito hipolipidêmico do (PhSe)2, um composto orgânico de Se, no modelo de hiperlipidemia aguda induzida por Triton WR-1339 em camundongos, bem como investigar se a hiperlipidemia aguda induzida pela administração intraperitonial (i.p.) de Triton WR-1339 altera parâmetros relacionados à ocorrência de dano oxidativo no tecido hepático de camundongos e determinar se o efeito antioxidante do (PhSe)2 está presente nesse processo. Para isso, o Triton WR-1339 foi injetado i.p. (400 mg/kg) em camundongos que estavam em jejum de 12 horas. O (PhSe)2 foi administrado oralmente (10 mg/kg) 30 minutos antes do Triton WR-1339. 24 horas após a injeção do Triton WR-1339, amostras de sangue foram coletadas para dosagem das concentrações de lipídios plasmáticos. Os níveis de espécies reativas ao ácido tiobarbitúrico (TBARS) e ácido ascórbico, bem como a atividade das enzimas catalase e glutationa peroxidase foram determinados no tecido hepático. A administração de (PhSe)2 foi capaz de prevenir o aumento nos níveis de colesterol total, colesterol não-HDL e triglicerídeos bem como aumentar os níveis de HDL-colesterol no plasma de camundongos hiperlipidêmicos. No protocolo experimental utilizado nesse estudo não foram observadas alterações nos parâmetros hepáticos de estresse oxidativo analisados. Conseqüentemente, o efeito antioxidante do (PhSe)2 não pode ser verificado. Os resultados obtidos nesse trabalho encorajam a realização de estudos posteriores no intuito de elucidar o exato mecanismo através do qual o (PhSe)2 exerce seu efeito hipolipidêmico.
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Oskinova, L., W. R. Hamann, A. Feldmeier, Richard Ignace, and Y. H. Chu. "Discovery of X-ray Emission from the Wolf-Rayet Star WR 142 of Oxygen Subtype." Digital Commons @ East Tennessee State University, 2009. https://dc.etsu.edu/etsu-works/6260.
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We report the discovery of weak yet hard X-ray emission from the Wolf-Rayet (WR) star WR 142 with the XMM-Newton X-ray telescope. Being of spectral subtype WO2, WR 142 is a massive star in a very advanced evolutionary stage shortly before its explosion as a supernova or gamma-ray burst. This is the first detection of X-ray emission from a WO-type star. We rule out any serendipitous X-ray sources within approximate to 1 '' of WR 142. WR 142 has an X-ray luminosity of L(X) approximate to 7 x 10(30) erg s(-1), which constitutes only less than or similar to 10(-8) of its bolometric luminosity. The hard X-ray spectrum suggests a plasma temperature of about 100 MK. Commonly, X-ray emission from stellar winds is attributed to embedded shocks due to the intrinsic instability of the radiation driving. From qualitative considerations we conclude that this mechanism cannot account for the hardness of the observed radiation. There are no hints for a binary companion. Therefore the only remaining, albeit speculative explanation must refer to magnetic activity. Possibly related, WR 142 seems to rotate extremely fast, as indicated by the unusually round profiles of its optical emission lines. Our detection implies that the wind of WR 142 must be relatively transparent to X-rays, which can be due to strong wind ionization, wind clumping, or nonspherical geometry from rapid rotation.
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Törnqvist, Josefin. "‘How great!’ : A morpho-syntactic and semantic study on the two roots aA and wr." Thesis, Uppsala universitet, Institutionen för arkeologi och antik historia, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-323643.
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Egyptology is a discipline in which new research and new approaches are continuously necessary and – in most cases – provided. In this constant flow of new research, some subject areas are left untouched. The lemmas aA and wr have continuously had a very homogenous translation although the morphological and syntactical differences are quite visible. The generally accepted translation of both lemmas as ‘great’ is very singular and raises the question of whether aA and wr should be considered synonyms or not. The study consists of two combined parts; a morpho-syntactical analysis of aA and wr and their conjugations and distributions as well as a semantic analysis on different expressions and sentences where both aA and wr occur with the same, or similar, syntactical structure. The aim is to give clarification to the correlation between the lemmas aA and wr and their interpretation. The study is not restricted to a specific time period, but regards linguistic developments as an important factor in the analysis. An important conclusion from this study is the clear, preferred use of wr as a qualifier for physical greatness, as opposed to aA which appears in contexts more related to metaphorical greatness. During Late Egyptian the opacity of the different uses of aA and wr increases and the differentiation becomes quite fuzzy.
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Vale, Richard Thomas Robert. "On category O for the rational Cherednik algebra of the complex reflection group (Z/lZ) wr Sn." Thesis, University of Glasgow, 2007. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.437932.
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Schweickhardt, Jörg. "Analyse hochaufgelöster spektroskopischer Zeitserien der Wolf-Rayet-Doppelsternsysteme g2 [gamma 2] Velorum, WR 22 und HD 5980." [S.l. : s.n.], 2000. http://www.bsz-bw.de/cgi-bin/xvms.cgi?SWB8832580.
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Harris, Melissa. "Left-Right Symmetric Model : Putting lower bounds on the mass of the heavy, charged WR gauge boson." Thesis, Uppsala universitet, Högenergifysik, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-329683.
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In this project I have studied the left-right symmetric model (LRSM) as a candidate beyond standard model theory of particle physics. The most common version of the theory, called the minimal LRSM, has been studied and tested extensively for several decades. I have therefore modied this minimal LRSM by adapting the scalar sector and computing the mass of the charged right-handed gauge bosons WR for this particular scalar sector. I carried out a study of the theory and implemented it into FeynRules, in order to simulate LHC events using MadGraph. This allowed computation of the cross-section for the decay WR to a top and a bottom quark as a function of the mass of WR , which was compared with CMS data for the same decay, with proton-proton collisions at a centre of mass energy of 13 TeV. The final result was a constraint on the mass of WR , with a lower bound of 3 TeV.
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Mather, Jonathan, and Nancy Shaw. "RANGE SAFETY CASE STUDY: WESTERN RANGE CENTRALIZED TELEMETRY PROCESSING SYSTEM (WR CTPS), A LARGE DISTRIBUTED GROUND SYSTEM." International Foundation for Telemetering, 2007. http://hdl.handle.net/10150/604505.
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ITC/USA 2007 Conference Proceedings / The Forty-Third Annual International Telemetering Conference and Technical Exhibition / October 22-25, 2007 / Riviera Hotel & Convention Center, Las Vegas, NevadaThis paper presents a case study of the Western Range Centralized Telemetry Processing Subsystem (WR CTPS). This system was developed by Lockheed Martin Integrated Systems and Global Services and L-3 Communications Telemetry-West as part of the Range Standardization and Automation (RSA) IIA program. Requirements included real-time simultaneous acquisition of 16 PCM streams at rates of up to 30M bits per second; real-time processing; and data display on workstations connected over a gigabit Ethernet network. This system is designed for range safety and needs to be fault-tolerant while maintaining 100 percent data availability in the event of a single failure during an operation. The development of such a system demanded a rigorous Systems Engineering approach to ensure the successful upgrade and deployment onto the range infrastructure. This case study provides an overview of the system technical requirements and its architecture. The summary presents challenges encountered during the development and lessons learned while meeting them.
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Tolentino, Scott A. "An analysis of the relative weight (Wr) of yellow perch from Indiana waters of Lake Michigan, 1984-91." Virtual Press, 1992. http://liblink.bsu.edu/uhtbin/catkey/834610.
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Relative weight (Wr) of yellow perch (Perca flavescens) was evaluated for fish collected from the Indiana waters of Lake Michigan in June, July and August of 1976 and 1984-1991. Computation of Wr was completed for individual fish in 20 mm intervals over the size range from 100-219 mm using Wr = (W/Ws) 100 where W=weight of a fish in grams and Ws=standard weight for a fish of the same length. Length was highly correlated with weight in all years for males, females and sexes combined (r=0.97-0.99). Distributions of predicted weights for fish at 130 mm and 250 mm were at or near modes of the populations used to construct the Ws equation for yellow perch. Relative weights consistently decreased with increasing size in all years for males, females and sexes combined. Using 1976 length-weight data when the yellow perch population was sparse and fast growing as a standard (100%) for comparison, relative condition factors (Q) increased with increasing size in some years and decreased with increasing size in others for males females and sexes combined and it did not appear to be length dependent. When comparing Wr at 100 mm and 200 mm by sex and month, f hales had higher Wr than males at 100 mm in seven of nine years in June, six of nine years in July and only four of nine years in August. Female fish also had higher Wr than males at 200 mm in eight of nine years in June and July and six of nine years in August. There appeared to be no consistent pattern or trend of Wr increasing or decreasing by month for males, females or sexes combined. When Kn was evaluated for 100 mm and 200 mm fish by sex and year, male fish had higher Kn than females at 100 mm in all eight years. Male and female fish at 200 mm were more similar; male fish had higher Kn in three years, lower Kn in three years and equal Kn in two years. No relationships were found at 200 mm comparing Wr or Kn and CPE (quality/ h) for males (r=0.43; r=0.42), females (r=0.12; r=0.13) or sexes combined (r=0.28; r=0.22). Simple linear correlations of proportional stock density (PSD) with Wr and Kn revealed relative weights increased with PSD for 100 mm (r=0.51) and 200 mm (r=0.72) fish. Relative condition factors also increased with PSD for 100 mm fish, however the relationship was weak (r=0.30) but a strong correlation was found between Kn and PSD (r=0.81) for 200 mm fish. Based on these results, it appears that either Kn or Wr may be used inassessing the condition of yellow perch from the Indiana waters of Lake Michigan.Department of Biology
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St-Louis, Nicole, Patrick Tremblay, and Richard Ignace. "Polarization Light Curve Modeling of Corotating Interaction Regions in the Wind of the Wolf-Rayet Star Wr 6." Digital Commons @ East Tennessee State University, 2018. https://dc.etsu.edu/etsu-works/2690.
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The intriguing WN4b star WR 6 has been known to display epoch-dependent spectroscopic, photometric and polarimetric variability for several decades. In this paper, we set out to verify if a simplified analytical model in which corotating interaction regions (CIRs) threading an otherwise spherical wind is able to reproduce the many broad-band continuum light curves from the literature with a reasonable set of parameters. We modified the optically thin model developed by Ignace, St-Louis & Proulx-Giraldeau to approximately account for multiple scattering and used it to fit 13 separate data sets of this star. By including two CIRs in the wind, we obtained reasonable fits for all data sets with coherent values for the inclination of the rotation axis (i0 = 166°) and for its orientation in the plane of the sky, although in the latter case we obtained two equally acceptable values (ψ = 63° and 152°) from the polarimetry. Additional line profile variation simulations using the Sobolev approximation for the line transfer allowed us to eliminate the ψ = 152° solution. With the adopted configuration (i0 = 166° and ψ = 63°), we were able to reproduce all data sets relatively well with two CIRs located near the stellar equator and always separated by ∼90° in longitude. The epoch dependence comes from the fact that these CIRs migrate along the surface of the star. Density contrasts smaller than a factor of 2 and large opening angles for the CIR (β⪆35∘) were found to best reproduce the type of spectroscopic variability reported in the literature.
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Flodman, Mikael. "Building a Sporting Goods Recommendation System." Thesis, KTH, Skolan för datavetenskap och kommunikation (CSC), 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-169711.
Full textAbstract:
This thesis report describes an attempt to build a recommender system for recommending sporting goods in an e-commerce setting, using the customer purchase history as the input dataset. Two input datasets were considered, the item purchases dataset and the item-category dataset. Both the datasets are implicit, that is not explicitly rated by the customer. The data is also very sparse that very few users have purchased more than a handful of the items featured in the dataset. The report describes a method for dealing with both the implicit datasets as well as addressing the problem of sparsity. The report introduces SVD (Single Value Decomposition) with matrix factorization as a implementation for recommendation systems. Specifically implementations in the Apache Mahout machine learning framework.Denna rapport beskriver ett tillvägagångssätt för att med kundernas köphistorik bygga ett rekommendationssystem för rekommendation av sportprodukter på en e-handelsplats. Två olika datamängder behandlas, köphistorik per produkt och kund, samt köpfrekvensen per produktkategori per kund i köphistoriken. Båda är implicita datamängder, vilket betyder att kunderna inte har explicit uttryckt en åsikt för eller emot produkten, utan implicit uttrycker preferens genom sitt köp. Datan är även mycket gles, vilket betyder att den enskilda kunden generellt bara köpt en liten del av den totala mängden av sålda varor. Rapporten behandlar en metod som behandlar både den implicita karaktären av data och gleshets problemet. Rapporten introducerar SVD (Single Value Decomposition) med matrisfaktorisering som en metod för att implementera rekommendationssystem. Specifikt implementerat med hjälp av maskininlärningsbiblioteket Apache Mahout.
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Hirata, Mario Hiroyuki. "Efeitos do Triton WR 1339, sulfato de protamina E heparina sobre a lipólise e a remoção plasmática de quilomícrons artificiais em ratos." Universidade de São Paulo, 1985. http://www.teses.usp.br/teses/disponiveis/9/9132/tde-20032008-092759/.
Full textAbstract:
Emulsões artificiais sem proteína simulando quilomicrons e remanescentes de quilomícron foram preparadas por sonicalcação de trioleína, lecitina, colesteril oleato e colesterol em solução aquosa. A seguir foram ultracentrifugadas em gradiente descontínuo de densidade. As emulsões, marcadas com 3H-trioleína e 14C-colesteril oleato foram injetadas via intra-arterial em ratos controle e em ratos tratados com Triton WR1339, sulfato de protamina e heparina, medindo-se a seguir a remoção plasmática do colesteril-ester e dos triglicérides, durante dez minutos. O Triton WR 1339 e a protamina inibiram a lipólise dos quilomícrons artificiais, diminuindo a remoção destas partículas do plasma. O Triton WR 1339 mostrou ser mais efetivo que a protamina nestes efeitos. Por outro lado, a heparina promoveu uma lipólise rápida e brusca nos quilomícrons artificiais, assim como uma aceleração na remoção destas partículas do plasma. Em contraste flagrante com esses resultados, o metabolismo dos remanescentes de quilomícron não foi consideravelmente afetado pelo tratamento com Triton e heparina. Estas experiências indicam que as emulsões artificiais reproduzem o comportamento metabólico dos quilomícrons e remanescentes de quilomícron naturais, em condições em que a atividade da lipase lipoproteica esteja alterada.Protein-free emulsions models of chylomicrons and chylomicron remnants were prepared by sonicating triolein, lecithin., cholesteryl oleate and cholesterol in aqueous saline media, followed by ultracentrifugation in density gradient solution. The 3H-triolein and 14C-cholesteryl oleate labeled emulsions were injected into the carotid artery of control rats and rats treated with Triton WR 1339, protamine sulphate and heparin. Plasma removal of both labels was measured during ten minutes in two minutes intervals. Triton WR 1339 and protamine sulphate strongly inhibited lipolysis of chylomicron-like emulsions leading to delayed removal of the particles from blood. Triton WR 1339 de appeared to be more effective than protamine to elicit these effects. On the other hand, heparin produced instantaneous lipolysis of the chylomicron-like particles markedly enhancing its removal from plasma. Contrarily, chylomicron remnant-like emulsions were not considerably affected either by Triton WR 1339 or by heparin treatment. The above described results obtained with artificial emulsions support current concepts on the metabolic behavior of natural chylomicron and remnant submitted to changes in lipoprotein lipase action.
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Schäfer, Fabian. "Reproductive management and gamete quality in pikeperch (Sander lucioperca)." Doctoral thesis, Humboldt-Universität zu Berlin, Lebenswissenschaftliche Fakultät, 2016. http://dx.doi.org/10.18452/17636.
Full textAbstract:
Der Zander (Sander lucioperca) hat großes Potential für die Aquakultur in Europa. Die Verbreitung wird durch einen Mangel an Satzmaterial erschwert, welcher durch Variabilität der Gametenqualität verursacht wird. Im Gegensatz zu Effekten der ganzjährigen Reproduktion oder der Laicherfahrung, war besonders die Weibchengröße mit Variabilität der Eiqualität assoziiert. Sehr große Weibchen zeigten einen verringerten Reproduktionserfolg. Maternale Faktoren waren mit Aspekten der Eizusammensetzung (bes. Fettsäuren) verknüpft, welche wiederum mit Befruchtungsraten und Embryoüberleben korrelierten. Zusätzlich waren Trockengewicht, Cortisolgehalt und Größe der Eier mit der Fekundität und dem Entwicklungspotential der Eier verknüpft. Ein erheblicher Anteil der Variabilität in der Eientwicklung (47.1% Befruchtung; 58.2% 24 h, 47% 48 h, 43.9% 72 h Embryoüberleben; 46.6% Schlupf; 88.9% geschlüpfte Larven) konnte durch eine Kombination von maternalen Merkmalen und Eiparametern erklärt werden. Obwohl ein hoher Befruchtungserfolg (durchschnittlich 89.2%) verzeichnet wurde, gibt es Möglichkeiten um Befruchtungsprotokolle hinsichtlich der Handhabung männlicher Gameten beim Zander zu optimieren. Die Spermien verschiedener Männchen werden häufig vor der Befruchtung zusammengeführt (Pooling) oder kurz Zeit (Stunden) gelagert bis ovulierte Eier zur Verfügung stehen. Ein Verlust der Spermienqualität (Motilität, Geschwindigkeit) während kurzer Lagerung konnte durch Puffer oder die Zugabe von Melatonin bzw. Progesteron nicht verhindert werden. Die Transfusion von Seminalflüssigkeit zwischen Spermien mit niedriger und hoher Qualität resultierte in einer Abnahme bei Männchen mit anfänglich hoher Spermiengeschwindigkeit. Die Qualität von Spermien mit niedriger Qualität wurde nicht gesteigert. Diese Erkenntnisse liefern Empfehlungen für das Management von Brutbetrieben und zeigen Potential zur Optimierung von Reproduktionsprotokollen bezüglich der in vitro Befruchtung beim Zander auf.The pikeperch (Sander lucioperca) has great potential for European aquaculture diversification, but the propagation is impeded by a shortage of stocking material caused by variability in gamete quality. Here, maternal size rather than out-of-season spawning or spawning experience was associated with variability in egg quality with very large females showing decreasing reproductive performance. Maternal factors were linked to the egg composition mainly in regard to fatty acid (FA) profiles, which in turn were correlated with rates of fertilization and embryo survival. In addition, egg size, dry weight and cortisol content were associated with fecundity and embryo survival until hatching. Consequently, a substantial variability in egg developmental performance could be explained (47.1% fertilization; 58.2% 24 h, 47% 48 h, 43.9% 72 h embryo survival; 46.6% hatching; 88.9% hatched larvae) by a combination of maternal traits and egg quality parameters. Despite the overall high fertilization observed here (89.2% on average), there is still potential for fine tuning of protocols for in vitro fertilization in pikeperch with regard to the management of male gametes. Sperm of different males is often pooled prior to fertilization or stored for short periods (hours) until ovulated eggs become available. A loss of sperm quality (motility, velocity) could not be prevented during short-term storage using sperm extenders and enhancement supplements (melatonin, progesterone). Transfusion of seminal fluid between low and high quality sperm to assess pooling effects resulted in a significant decrease in sperm with high initial velocity, whereas the velocity of low quality sperm could not be improved. These findings deliver valuable management advice for hatcheries and indicate potential for optimization in regard to in vitro reproduction protocols in pikeperch.
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Capriotti, Giuseppe. "Classificazione spettrale delle stelle." Bachelor's thesis, Alma Mater Studiorum - Università di Bologna, 2018. http://amslaurea.unibo.it/16375/.
Full textAbstract:
Tutte le nostre informazioni riguardo le proprietà fisiche delle stelle derivano più o meno direttamente dallo studio dei loro spettri, in particolare attraverso lo studio della variazione delle linee di assorbimento, della temperatura e della composizione. Dopo una rapida definizione di stella e di corpo nero, si passa alla descrizione delle classificazioni di Harvard, di Yerkes e del diagramma H-R. Infine si giunge allo studio degli spettri stellari e all'analisi e al comportamento delle righe di assorbimento che li caratterizzano.
Vengono quindi citate le importanti equazioni di Boltzmann e Saha. Infine si concentra l'attenzione su un peculiare caso astrofisico, le stelle di Wolf-Rayet.
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Hubrig, S., K. Scholz, Wolf-Rainer Hamann, M. Schöller, Richard Ignace, I. Ilyin, K. G. Gayley, and Lidia M. Oskinova. "Searching for a Magnetic Field in Wolf-Rayet Stars Using FORS 2 Spectropolarimetry." Digital Commons @ East Tennessee State University, 2016. https://dc.etsu.edu/etsu-works/2694.
Full textAbstract:
To investigate if magnetic fields are present in Wolf–Rayet stars, we selected a few stars in the Galaxy and one in the Large Magellanic Cloud (LMC). We acquired low-resolution spectropolarimetric observations with the European Southern Observatory FORS 2 (FOcal Reducer low dispersion Spectrograph) instrument during two different observing runs. During the first run in visitor mode, we observed the LMC Wolf–Rayet star BAT99 7 and the stars WR 6, WR 7, WR 18, and WR 23 in our Galaxy. The second run in service mode was focused on monitoring the star WR 6. Linear polarization was recorded immediately after the observations of circular polarization. During our visitor observing run, the magnetic field for the cyclically variable star WR 6 was measured at a significance level of 3.3σ (〈Bz〉 = 258 ± 78 G). Among the other targets, the highest value for the longitudinal magnetic field, 〈Bz〉 = 327 ± 141 G, was measured in the LMC star BAT99 7. Spectropolarimetric monitoring of the star WR 6 revealed a sinusoidal nature of the 〈Bz〉 variations with the known rotation period of 3.77 d, significantly adding to the confidence in the detection. The presence of the rotation-modulated magnetic variability is also indicated in our frequency periodogram. The reported field magnitude suffers from significant systematic uncertainties at the factor of 2 level, in addition to the quoted statistical uncertainties, owing to the theoretical approach used to characterize it. Linear polarization measurements showed no line effect in the stars, apart from WR 6. BAT99 7, WR 7, and WR 23 do not show variability of the linear polarization over two nights.
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Mugodo, James, and n/a. "Plant species rarity and data restriction influence the prediction success of species distribution models." University of Canberra. Resource, Environmental & Heritage Sciences, 2002. http://erl.canberra.edu.au./public/adt-AUC20050530.112801.
Full textAbstract:
There is a growing need for accurate distribution data for both common and rare plant
species for conservation planning and ecological research purposes. A database of more than
500 observations for nine tree species with different ecological and geographical
distributions and a range of frequencies of occurrence in south-eastern New South Wales
(Australia) was used to compare the predictive performance of logistic regression models,
generalised additive models (GAMs) and classification tree models (CTMs) using different
data restriction regimes and several model-building strategies. Environmental variables
(mean annual rainfall, mean summer rainfall, mean winter rainfall, mean annual temperature,
mean maximum summer temperature, mean minimum winter temperature, mean daily
radiation, mean daily summer radiation, mean daily June radiation, lithology and
topography) were used to model the distribution of each of the plant species in the study
area.
Model predictive performance was measured as the area under the curve of a receiver
operating characteristic (ROC) plot. The initial predictive performance of logistic regression
models and generalised additive models (GAMs) using unrestricted, temperature restricted,
major gradient restricted and climatic domain restricted data gave results that were contrary
to current practice in species distribution modelling. Although climatic domain restriction
has been used in other studies, it was found to produce models that had the lowest predictive
performance. The performance of domain restricted models was significantly (p = 0.007)
inferior to the performance of major gradient restricted models when the predictions of the
models were confined to the climatic domain of the species. Furthermore, the effect of data
restriction on model predictive performance was found to depend on the species as shown by
a significant interaction between species and data restriction treatment (p = 0.013). As found
in other studies however, the predictive performance of GAM was significantly (p = 0.003)
better than that of logistic regression. The superiority of GAM over logistic regression was
unaffected by different data restriction regimes and was not significantly different within
species.
The logistic regression models used in the initial performance comparisons were based on
models developed using the forward selection procedure in a rigorous-fitting model-building
framework that was designed to produce parsimonious models. The rigorous-fitting modelbuilding
framework involved testing for the significant reduction in model deviance (p =
0.05) and significance of the parameter estimates (p = 0.05). The size of the parameter
estimates and their standard errors were inspected because large estimates and/or standard
errors are an indication of model degradation from overfilling or effecls such as mullicollinearily.
For additional variables to be included in a model, they had to contribule
significantly (p = 0.025) to the model prediclive performance. An attempt to improve the
performance of species distribution models using logistic regression models in a rigorousfitting
model-building framework, the backward elimination procedure was employed for
model selection, bul it yielded models with reduced performance.
A liberal-filling model-building framework that used significant model deviance reduction at
p = 0.05 (low significance models) and 0.00001 (high significance models) levels as the
major criterion for variable selection was employed for the development of logistic
regression models using the forward selection and backward elimination procedures. Liberal
filling yielded models that had a significantly greater predictive performance than the
rigorous-fitting logistic regression models (p = 0.0006). The predictive performance of the
former models was comparable to that of GAM and classification tree models (CTMs). The
low significance liberal-filling models had a much larger number of variables than the high
significance liberal-fitting models, but with no significant increase in predictive
performance. To develop liberal-filling CTMs, the tree shrinking program in S-PLUS was
used to produce a number of trees of differenl sizes (subtrees) by optimally reducing the size
of a full CTM for a given species. The 10-fold cross-validated model deviance for the
subtrees was plotted against the size of the subtree as a means of selecting an appropriate
tree size. In contrast to liberal-fitting logistic regression, liberal-fitting CTMs had poor predictive performance.
Species geographical range and species prevalence within the study area were used to
categorise the tree species into different distributional forms. These were then used, to
compare the effect of plant species rarity on the predictive performance of logistic regression
models, GAMs and CTMs. The distributional forms included restricted and rare (RR)
species (Eucalyptus paliformis and Eucalyptus kybeanensis), restricted and common (RC)
species (Eucalyptus delegatensis, Eucryphia moorei and Eucalyptus fraxinoides),
widespread and rare (WR) species (Eucalyptus data) and widespread and common (WC)
species (Eucalyptus sieberi, Eucalyptus pauciflora and Eucalyptus fastigata). There were
significant differences (p = 0.076) in predictive performance among the distributional forms
for the logistic regression and GAM. The predictive performance for the WR distributional
form was significantly lower than the performance for the other plant species distributional
forms. The predictive performance for the RC and RR distributional forms was significantly
greater than the performance for the WC distributional form. The trend in model predictive
performance among plant species distributional forms was similar for CTMs except that the
CTMs had poor predictive performance for the RR distributional form.
This study shows the importance of data restriction to model predictive performance with
major gradient data restriction being recommended for consistently high performance. Given
the appropriate model selection strategy, logistic regression, GAM and CTM have similar
predictive performance. Logistic regression requires a high significance liberal-fitting
strategy to both maximise its predictive performance and to select a relatively small model
that could be useful for framing future ecological hypotheses about the distribution of
individual plant species. The results for the modelling of plant species for conservation
purposes were encouraging since logistic regression and GAM performed well for the
restricted and rare species, which are usually of greater conservation concern.
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Ohst, Torsten. "Genetische Einflüsse allochthoner Wasserfrösche auf endemische Wasserfroschpopulationen (R. kl. esculenta Komplex)." Doctoral thesis, Humboldt-Universität zu Berlin, Mathematisch-Naturwissenschaftliche Fakultät I, 2008. http://dx.doi.org/10.18452/15857.
Full textAbstract:
Allochthone Wasserfrösche haben in Deutschland und vielen anderen Ländern Europas zu Faunenverfälschungen geführt. Sie konkurrieren mit einheimischen Tieren und stellen aus genetischer Sicht eine Bedrohung der Bestände dar. In dieser Arbeit wurden die Genotypen von 447 Wasserfroschproben aus Deutschland sowie 460 aus anderen Teilen Europas untersucht. Im Gesamtdatensatz konnten 56 ITS2- und 65 ND3-Genotypen nachgewiesen werden. Unter den 20 in Deutschland gefunden ITS2-Allelen wurden zwei Rana ridibunda-ähnliche Genotypen als autochthon und fünf als allochthon erkannt (Häufigkeit 7 %), der Status weiterer fünf ITS2-Allele war nicht klar zu belegen. Unter den 14 mitochondrialen Genotypen der R. ridibunda-Gruppe befanden sich drei autochthone, zehn allochthone (Häufigkeit 18 %) sowie eine Variante mit unklarem Status. Allochthone Genommerkmale wurden vor allem in Südwestdeutschland entlang des Rheins und im Ruhrtal nachgewiesen. Im Raum Karlsruhe konnte ein mitochondrialer Genotyp mit hohem Anteil festgestellt werden, der typisch für eine bisher nur aus Italien bekannte Art ist (R. bergeri). Da allochthone ITS2-Allele häufig heterozygot mit autochthonen Varianten auftreten, gibt es eindeutige Hinweise auf Hybridisierungen zwischen einheimischen und eingeschleppten Wasserfröschen. Aufzuchtsexperimente zeigten keine reduzierte Überlebenswahrscheinlichkeit von F1-Hybriden aus Kreuzungen zwischen autochthonen R. ridibunda und allochthonen R. cf. ridibunda aus Anatolien. Um die Rolle allochthoner Wasserfrösche bei der Verbreitung von Krankheitserregern beurteilen zu können, wurden Nachweistests für die Amphibien-Chytridiomykose durchgeführt. Die Nachweistests ergaben eine Prävalenz des Erregers (Batrachochytrium dendrobatidis) von 6,3 % unter deutschen Proben. Da die Chytridiomykose überwiegend in Populationen auftrat, in denen auch allochthone Wasserfrösche vorkamen, wird ein Zusammenhang zwischen Einschleppungsereignissen und dem Auftreten des Erregers vermutet.Allochthonous water frogs have been introduced into Germany and other European countries. They compete with autochthonous water frogs and threaten the genetic integrity of native populations. In the present work the genotypes of 447 water frogs collected in Germany as well as 460 samples from various European countries have been determined and compared. In the complete dataset 56 ITS2- and 65 ND3-genotypes were identified. Among the 20 ITS2-alleles found in Germany, two indigenous and five introduced Rana ridibunda-like genotypes (relative frequency 7%) occurred. Five R. ridibunda alleles could not assigned as either indigenous or exotic. Among the 14 mitochondrial genotypes of the R. ridibunda-group three autochthonous and ten introduced (relative frequency 18%) variants could be identified, whereas the status of one mt-genotype remained unclear. Exotic alleles were mainly found in southwest Germany along the river Rhine and along the Ruhr in the Ruhr area. The wide distribution of a mitochondrial genotype previously known from Italian water frogs (R. bergeri) was ascertained in the region surrounding Karlsruhe. Allochthonous ITS2-alleles often occur heterozygously combined with autochthonous alleles. This is a strong evidence for cases of hybridisations between indigenous and introduced water frogs. Crossing experiments between autochthonous R. ridibunda and Anatolian water frogs (R. cf. ridibunda) revealed no reduced viability among the F1-hybrids. To evaluate the possible role of introduced water frogs on the dispersal of infectious diseases, detection tests of the amphibians-chytridiomycosis were carried out. The detection tests for its pathogen, Batrachochytrium dendrobatidis, on the tissue samples collected in Germany showed a prevalence of 6.3%. Most of the infected frogs were found in populations influenced by non-native water frogs. This points towards a possible relationship between introduction events and the occurrence of the pathogen.
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Braun, Katrin. "Comparative study on the nervous system of Tunicata to elucidate tunicate phylogeny and character transformations." Doctoral thesis, Humboldt-Universität zu Berlin, 2019. http://dx.doi.org/10.18452/19930.
Full textAbstract:
Tunicata umfasst 3000 marine Arten, mit sehr unterschiedlichen Lebensstrategien. Als eines der drei großen Taxa innerhalb der Chordata, stellt die Evolution der Tunikaten eine Schlüsselkomponente bei der Aufklärung der Evolution der Chordaten und Cranioten dar. Dafür ist ein Verständnis der Merkmalstransformationen innerhalb der Tunikaten notwendig. Leider sind die internen Verwandtschaftsverhältnisse der fünf großen Tunikatentaxa in verschiedenen molekularphylogenetischen Studien widersprüchlich. Bisher gibt es nur wenige morphologische phylogenetische Analysen. Ein Schwerpunkt dieser Arbeit liegt auf der Untersuchung neuroanatomischer Merkmale, da das Nervensystem wahrscheinlich phylogenetische Informationen enthält. Durch das Anwenden moderner morphologischer Methoden, wie hochauflösende konfokale Laserscan- und Elektronenmikroskopie (REM und TEM), und 3d Rekonstruktionen basierend auf lichtmikroskopischen Schnitten, wurde die Verfügbarkeit neuroanatomischer Daten wesentlich verbessert. Die Ergebnisse zeigen, dass die Variation neuroanatomischer Merkmale größer ist als bisher angenommen und dass sich die Gehirnanatomie und die Verteilung von Neurotransmittern in den zwei Stadien der Thaliaceen unterscheidet. Neue unabhängige Merkmale des Nervensystems wurden in einer Matrix kodiert. Ergänzt mit traditionellen in der Tunikatentaxonomie verwendeten Merkmalen, entstand die bisher umfangreichste morphologische Datenmatrix, die 116 Merkmale für insgesamt 54 Arten umfasst. Die kladistische Analyse ergab monophyletische Tunicata, in denen die Appendicularia die Schwestergruppe der übrigen Tunikaten bildet. Ascidiacea ist monophyletisch, während „Thaliacea“ paraphyletisch ist. Zusätzlich wurde eine kombinierte phylogenetische Analyse basierend auf den morphologischen Daten und 18S rDNA-Sequenzen durchgeführt. Eine stufenweise stärkere Gewichtung phänotypischer Merkmale zeigt, dass die morphologischen Daten das Ergebnis der kladistischen Analyse stark beeinflussen.Tunicata comprises 3000 marine species with diverse life-history strategies. As one of the three major chordate taxa, the evolution of tunicates plays a key role to elucidate chordate and craniate evolution. Therefore, a broader understanding of character transformations within tunicates is essential, but the interrelationships of the five main tunicate subtaxa in previous molecular phylogenetic analyses were contradictory. Morphological phylogenetic analyses are rare. In this comparative study emphasis was given to neuroanatomical characters, as the nervous system probably contains phylogenetic information. Applying modern morphological techniques like high-resolution confocal laser scanning microscopy and electron microscopy (SEM and TEM), serial sectioning for light microscopy, and digital 3d reconstruction, the number of available tunicate neuroanatomical data was considerably increased. It was revealed that the variation of neuroanatomical characters is higher than previously assumed, a specific pattern of serotonin-like immunoreactive cells in ascidians is present, and that brain anatomy and distribution of neurotransmitters in the two thaliacean life-cycle stages differs. Novel independent characters of the central nervous system were coded in a matrix for a cladistic analysis. Including traditional morphological from tunicate literature this effort resulted in the largest morphological data matrix to date, containing 116 phenotypic characters and 54 species. The cladistic analysis resulted in monophyletic Tunicata, with Appendicularia the sister taxon to the remaining tunicates. Furthermore, the monophyly of Ascidiacea is supported, whereas “Thaliacea” are paraphyletic. An additional phylogenetic analysis combining morphological and 18S rDNA-sequence data was performed. A reevaluation of this dataset with a successively increased weighting of the phenotypic data showed that morphological data strongly influence the outcome of the cladistic analysis.
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Yuan, Chao. "Exploratory research for pathogenesis of papulopustular rosacea and skin barrier research in Besançon and Shanghai." Thesis, Bourgogne Franche-Comté, 2017. http://www.theses.fr/2017UBFCE004/document.
Full textAbstract:
La rosacée est une maladie inflammatoire chronique de la peau qui affecte presque exclusivement la peau faciale centrale. Actuellement, la morbidité de la rosacée en Chine augmente. Chaque signe clinique de la rosacée est lié à la pathogenèse de cette maladie cutanée dont la physiopathologie très complexe, implique différents types cellulaires et molécules de la peau et divers sous-types. Selon ces résultats, nous avons pu évaluer le rôle de la barrière cutanée et des microorganismes dans la rosacée. Le premier objectif de cette thèse était de déterminer si un microbiote cutané altéré est le résultat d'une pathophysiologie sous-jacente. Nous avons également comparé la rosacée chez des patients chinois et français en évaluant la fonction de la barrière cutanée. Ces tests aideront au choix de la thérapie la plus adaptée pour traiter des patients atteints de rosacée. A travers ces 4 années de recherche de thèse, nous avons montré que : • La biopsie standard de la surface de la peau est une bonne méthode pratique en clinique pour mesurer la densité de Demodex Folliculorum chez les patients atteints de rosacée et d'acné. Le RCM peut être un meilleur choix que le SSSB en raison de son exactitude, de son exhaustivité et de sa procédure indolore non invasive in vivo. RCM semble être plus sensible que son prédécesseur. D'après les résultats de l'analyse du nombre de Demodex dans les lésions de patients atteints de PPR, nous avons constaté que ce nombre est beaucoup plus élevé à Besançon qu'à Shanghai. Les caractéristiques physiologiques de la rosacée sont fortement associées aux interactions entre l'hôte et les micro-organismes, et nos données indiquent l'importance de la colonisation bactérienne. Dans la pathogenèse de la rosacée, il est donc souhaitable de prendre en compte l'altération du microbiote cutané et des réponses immunitaires.La MRC peut détecter dans la peau sensible et la rosacée, les structures endommagées par l'épidermolyse du patient, y compris la parakératose, le désordre en nid d'abeille. Elle pourrait être utilisée comme nouvelle méthode auxiliaire de détection et de diagnostic.l est important de prendre en compte l'association des microorganismes, des paramètres biophysiques de la peau, du microenvironnement et de la barrière cutanée, y compris les barrières physiques, chimiques et microbiennes, même dans la peau normale, dans la conception des produits de soins de la peau et des médicaments antimicrobiensRosacea is a common chronic inflammatory skin disease that almost exclusively affects the central facial skin. In these years, the morbidity ofrosacea in China has increased significantly. Each clinical signs of rosacea are related by the pathogenesis of this skin disease, and its pathophysiology is very complex, involving various cell types and molecules in the skin, and various subtypes. According these viewpoints, we chose the ERT and PPR patients, and focused on the microorganism and skin barrier to know more about the pathogenesis of rosacea. The first objective of this thesis was to know more about that whether the skin impaired microbiota is a response to changes in the skin microenvironment resulting from rosacea's underlying pathophysiology. And we also interested in the difference between the French rosacea patients and the Chinese patients in the skin barrier function. Another objective was to find the practical non-invasive testing technology to evaluate the rosacea patients'skin barrier damage condition and in the treatment efficacy. Through these testing, we could know more about the skin barrier situation of the patient, which will help us to choose the more suitable therapy approach for the long time treatment period for rosacea patients. Through these 4 years research of this thesis, we have shown that: Standardized Skin Surface Biopsy is a good practical method to measure Demodex Folliculorum density in rosacea and acne patients in clinical experience. RCM may be a better choice than SSSB because of its accuracy, completeness and as an in vivo noninvasive painless procedure. RCM appears to be a more sensitive method which could be used more in research or clinical studies or to follow up treatment or recurrence. According to the results of testing demodex number in les ions of PPR patients, we found that it was much higher in Besancon than Shanghai even ifwe used the same method. The physiological features of rosacea are strongly associated with the interactions between the host and microorganisms, and our data indicate the importance of the bacterial colonization balance on the skin surface. In the pathogenesis ofrosacea, we'd better to care more about the skin dysbiosis with the enhanced immunity responds. RCM can detect in sensitive skin and rosacea patient epidermal damaged structures, including parakeratosis, disarranged honeycomb pattern and reduced honeycomb pattern depth. lt could be used as a new kind of the new auxiliary method in the detection and diagnosis, providing the new mentality for the diagnosis and treatment. It is important that the association of microorganisms, skin biophysical parameters, microenvironment and skin barrier function including physical, chemical and microbial barriers even in normal skin, which is essential for designing skin care products and anti-microbial drugs
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Mohneke, Meike. "(Un)sustainable use of frogs in West Africa and resulting consequences for the ecosystem." Doctoral thesis, Humboldt-Universität zu Berlin, Mathematisch-Naturwissenschaftliche Fakultät I, 2011. http://dx.doi.org/10.18452/16296.
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Amphibien sind global von einem Artenrückgang betroffen, wobei Ausbeutung bestimmter Froscharten einer der Gründe hierfür ist. Die vorliegende Arbeit gibt erstmals Einblick in Form, Umfang und Auswirkungen der extensiven Nutzung von Fröschen in Westafrika. Interviews mit Konsumenten und in den Froschhandel Involvierten ermöglichten die Nutzung und den Handel von Fröschen in Burkina Faso, Benin und Nigeria zu quantifizieren und zu bewerten. Während der Froschhandel in Burkina Faso eher auf lokaler Ebene abläuft, ließ sich im Norden Benins und in Nigeria ein intensiver grenzüberschreitender Handel nachweisen. Um einen möglichen anthropogenen Einfluss auf natürliche Amphibien Gemeinschaften zu ermitteln wurden natürliche Gewässer untersucht. Auf Kaulquappenebene wurden Artenverluste und die sich daraus ergebenen Konsequenzen studiert. Temporäre Savannengewässer wurden in zwei Untersuchungsgebieten in Burkina Faso untersucht, wobei die Gewässer jeweils in Gebieten mit unterschiedlichem Störungsgrad lagen: in Dörfern mit Froschfang, gegenüber in geschützten Gebieten mit Froschfangverbot. Generell konnte in den anthropogen gestörten Gebieten ein niedrigerer Artenreichtum mit gleichzeitig veränderter Zusammensetzung der Artengemeinschaften konstatiert werden. Für diese Unterschiede waren primär anthropogen veränderte Habitatfaktoren verantwortlich. Aber auch das Froschfangen kann Grund für veränderte Kaulquappengemeinschaften sein. Um Voraussagen für mögliche resultierende Konsequenzen treffen zu können ist es wichtig die ökologische Rolle betroffener Arten im System zu kennen. In künstlichen Gewässern wurde die trophische Position von vier Kaulquappenarten mit jeweils unterschiedlicher Nahrungsstrategie und die Konsequenzen ihres Verlustes für die restlichen Kaulquappen und bestimmter Ökosystemfaktoren, wie Moskitolarven, ermittelt. Die vier Kaulquappenarten unterschieden sich in ihrer trophischen Position. Zudem konnten komplexe Interaktionen zwischen den vier Fokusarten aufgedeckt werden, wobei die trophische Position je nach Gemeinschaft wechseln konnte. So konnte ich mit meiner Arbeit zeigen, dass der Verlust nur einer Art essentielle Konsequenzen für Amphibien Gemeinschaften und ökosystemische Prozesse haben kann. Chapter 1 Summary II IAmphibian populations are declining world wide, with overexploitation being one of the main reasons. In Africa frog exploitation has not been in the focus of scientific research yet. Herein I report first investigations of the frogs use from West Africa. Interviews with consumers and participants in the frog trade facilitated to quantify and evaluate the use and trade of frogs in Burkina Faso, Benin and Nigeria. In Burkina Faso the frog trade mainly took place on a local scale, whereas in northern Benin and Nigeria, I detected an intensive cross-border trade. In an empiric approach I examined if a possible anthropogenic impact could be found in natural tadpole communities. In two study regions in Burkina Faso I compared natural freshwater ponds situated of different disturbance regimes: ponds in and around villages, where frogs were collected for consumption, and in protected areas, where frog harvest was prohibited. Species richness was lower and species composition differed in anthropogenic disturbed areas. Anthropogenic altered habitat factors were mainly responsible for these differences. However, harvesting of adult amphibians could have affected tadpole composition and occurrences of particular species as well. To evaluate the effect of the potential loss of a species a better understanding of its ecological role is important. Therefore, I conducted an experiment to investigate the trophic position of four tadpole species and the consequences of species exclusion for the remaining species and on certain ecosystem parameters such as mosquito larvae. Isotopic analyses revealed that tadpole species differed in their trophic position. Various complex interactions between species occurred including shifts in trophic positions due to tadpole species composition. Thus the loss of just one species can have crucial consequences for the remaining amphibian community and furthermore for ecosystem processes. Chapter 1 Summary II I
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Dittrich, Carolin. "Reproductive behaviour of the European Common Frog (Rana temporaria)." Doctoral thesis, Humboldt-Universität zu Berlin, 2020. http://dx.doi.org/10.18452/21476.
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In meiner Dissertation untersuche ich das Paarungs- und Fortpflanzungsverhalten des Europäischen Grasfrosches (Rana temporaria) in einem evolutionären Kontext. Mein Ziel ist es zu verstehen, welche Mechanismen zur Bildung von Paaren führen, ob die Partnerwahl die Paarungsmuster erklärt, die wir beobachten können, und ob es evolutive Vorteile gibt, die sich aus der Paarung mit einem bestimmten Partner ergeben. Die Suche nach und die Konkurrenz um Paarungspartner führt zur Entwicklung verschiedener Paarungssysteme, Strategien und Taktiken, um den Reproduktionserfolg während der gesamten Lebensdauer zu erhöhen. Das Paarungsverhalten wird durch natürliche und sexuelle Selektion beeinflusst, wobei beide in unterschiedliche Richtungen wirken können. Für die meisten Individuen ist das Überleben unerlässlich, um sich so oft wie möglich zu reproduzieren, und dadurch die reproduktive Gesamtfitness zu erhöhen. Andererseits könnte ein auffälliges Verhalten bei der Fortpflanzung das Prädationsrisiko erhöhen. Der Akt der Paarung selbst kann bereits mit Risiken verbunden sein, welche sich auf die Überlebensraten auswirken können. Durch sexuelle Selektion könnten bestimmte sekundäre Geschlechtsmerkmale begünstigt werden, entweder aufgrund von Vorteilen im Wettbewerb innerhalb eines Geschlechts (intrasexuell), oder aufgrund spezifischer Präferenzen zwischen den Geschlechtern (intersexuelle Selektion). Damit sich die Partnerwahl entwickeln kann, muss der gewählte Paarungspartner Vorteile aufweisen, von denen der wählende Partner profitiert, denn die Wahl ist mit energetischen Kosten und zeitlichem Aufwand verbunden. Als Frühlaicher muss der Europäische Grasfrosch mit einem eingeschränktem Paarungszeitraum umgehen. Die Männchen konkurrieren um den Zugang zu Weibchen und es wird angenommen, dass sich Weibchen während der Paarung und Reproduktion passiv verhalten, da der hohe "Männchen-Überschuss" keine Wahl zulassen würde. Aus evolutionärer Sicht sollten Weibchen jedoch das wählerische Geschlecht sein und entscheiden mit wem sie sich paaren, da sie mehr Energie in die Eierproduktion investieren.In my thesis, I examine the mating and reproductive behaviour of the European Common Frog (Rana temporaria) in an evolutionary context. I aim to understand which mechanisms lead to the formation of pairs, if mate choice shapes the patterns of mating that we can observe and if there are benefits derived from pairing with a specific mate. The search and competition for mating partners lead to the evolution of various mating systems, strategies and tactics to increase lifetime reproductive success. The mating behaviour is influenced by natural and sexual selection, whereby both could act in different directions. For most individuals, survival is essential in order to reproduce as often as possible to increase lifetime reproductive fitness. On the other hand, reproduction could increase predation risk due to conspicuous behaviour and risks associated with mating itself. Sexual selection could favour specific secondary sexual traits, either due to advantages in intrasexual competition, or by specific preferences of the choosy sex (intersexual selection). For mate choice to evolve, there need to be benefits associated with the chosen mating partner, because choosiness involves costs in terms of energy and time constraints during mating. As an explosive breeder, the European Common Frog has to deal with time constraints during the short breeding season. The males are competing for the access to females and it is assumed that females are passive during breeding due to a high male-biased operational sex ratio. However, from an evolutionary perspective females should be the choosy sex and should decide with whom to mate, as they invest more energy into the production of eggs.
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Marcou, Alice. "Interactions d’ondes et de bord." Thesis, Bordeaux 1, 2011. http://www.theses.fr/2011BOR14267/document.
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Tout d'abord, des ondes de surface, solutions de problèmes aux limites hyperboliques non linéaires, sont étudiées : on construit une solution BKW sous forme de développement infini en puissance de epsilon. On le justifie rigoureusement, en construisant une solution exacte, qui admet ce développement asymptotique. On montre que la solution n'est pas nécessairement purement localisée sur la frontière, même lorsque le terme source l'est ; l'exemple d'un cas particulier de l'élasticité est traité. Ensuite, on étudie la réflexion d'ondes non linéaires discontinues, pour des problèmes aux limites hyperboliques, faiblement bien posés, ni fortement stables, ni fortement instables. On étudie comment les singularités d'une solution striée sont réfléchies lorsque la solution atteint la frontière. On prouve des estimations striées et en normes infinies. On montre qu'une discontinuité du gradient de la solution à travers un hyperplan peut être réfléchie en une discontinuité de la solution elle-mêmeWe first study surface waves, solutions of hyperbolic nonlinear boundary value problems. We construct BKW solutions in the weakly nonlinear regime with infinite expansion in powers of ε. We rigorously justify this expansion,constructing exact solutions, which admit the asymptotic expansions. We also show that the solution is not necessarily localized at the order O(ε∞) in the interior, even if the data are ; a particular case of elasticity is studied: we prove that fast oscillatory elastic surface waves can produce non trivial internal non oscillatory displacements.Afterwards, we study the reflection of non linear discontinuous waves, for weakly well-posed hyperbolic boundary value problems, satisfying the (WR) condition, which has been introduced in [1, 12], that is in a case where the IBVP is neither strongly stable, nor strongly unstable. We study how the singularities of a striated solution are reflected when the solution hits the boundary. We prove striated estimates and L∞ estimates and observe the loss of one derivative: we show that a discontinuityof the gradient of the solution across an hyperplane can be reflected in a discontinuity across an hyperplane of the solution itself
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Müller, Christina. "Behavioural reactions of cod (Gadus morhua) and plaice (Pleuronectes platessa) to sound resembling offshore wind turbine noise." Doctoral thesis, Humboldt-Universität zu Berlin, Mathematisch-Naturwissenschaftliche Fakultät I, 2008. http://dx.doi.org/10.18452/15725.
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Durch die Zunahme von Offshorewindparks wird der anthropogene Lärmpegel im Meer weiter ansteigen. Deshalb ist es notwendig, mögliche negative Effekte von Windturbinenschall auf Fische zu erkennen und zu minimieren. Um mögliche Effekte des Turbinenschalls auf Kabeljau (Gadus morhua) und Scholle (Pleuronectes platessa) zu untersuchen, wurden die Fische in Laborversuchen verschiedenen tiefen Frequenzen und Schallstärken, wie sie von Windturbinen emittiert werden ausgesetzt. Ein ringförmiges Betonversuchsbecken mit 10 Metern Durchmesser wurde mit Schallisolationwänden in verbundene Viertel unterteilt, wodurch im Becken eine Schalldruckdifferenz von 32-52 dB, abhängig von Frequenz und produziertem Schalldruckpegel erzeugt wurde. Die Fische, die sich frei im Becken bewegen und so, wenn sie wollten, den höchsten Schalldruckpegeln ausweichen konnten, wurden monofrequenten Tönen im Frequenzbereich zwischen 25 und 250 Hz in Schalldruckpegeln von 130 und 140 dB re 1 µPa ausgesetzt. Die Position der Fische im Becken wurde in den 24-Stunden-Phasen vor, während und nach Beschallung verglichen und zeigte in den meisten Versuchen während Beschallung signifikant weniger Kabeljau in der Nähe der Schallquelle, als in den Phasen vor und nach Beschallung. Scholle zeigte uneinheitliche Reaktionen, die teilweise auf Meideverhalten, in anderen Versuchen auf Attraktion durch den Schall hindeuteten. Die Ergebnisse lassen wenigstens kurzzeitige, durch Schall verursachte Verteilungsänderungen von Kabeljau in Offshorewindparks erwarten.The growing number of offshore wind farms will lead to an increase of anthropogenic noise in the sea. Research is therefore necessary to identify and minimize any potentially negative effects of offshore wind turbine noise on fish. To examine the potential impact of offshore wind farm noise emissions on cod (Gadus morhua) and plaice (Pleuronectes platessa), tank experiments were carried out exposing the fishes to different low frequencies at sound levels as emitted by wind turbines An annular concrete tank of 10 m in diameter was divided in connected quarters by sound barriers, so that sound pressure differences of 32 to 52 dB were achieved, depending on frequency and produced sound levels. Pure tones in the frequency range between 25 and 250 Hz were artificially emitted in sound levels of 130 and 140 dB re 1µPa. The experimental fish were free to move around in the tank and therefore could avoid the highest sound levels if they chose to. The location of fish in the 24 hour periods before, during and after sound production were compared and showed significantly lower numbers of cod in the vicinity of the sound source during sound presentation in the majority of the experiments. Reactions of plaice were ambiguous, suggesting both avoidance of, or attraction to the sound. From the results at least short-term changes in distribution of cod related to sound in the vicinity of offshore wind farms could be expected.
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Penner, Johannes. "Macroecology of West African amphibians." Doctoral thesis, Humboldt-Universität zu Berlin, Lebenswissenschaftliche Fakultät, 2014. http://dx.doi.org/10.18452/17035.
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Amphibienpopulationen sind weltweit bedroht. Für fundierte Entscheidungen im Naturschutz ist ein wissenschaftliches Hintergrundwissen notwendig. Eine wichtige Komponente ist die Verbreitung der Arten und die Gründe hierfür. Dies setzt auch Klarheit bezüglich des taxonomischen Status voraus. Vernachlässigte Regionen liegen meist in den Tropen. Um diese Lücke zu füllen, untersucht die vorliegende Arbeit die Makroökologie westafrikanischer Amphibien. Eine neue Art der Familie Phrynobatrachidae wird beschrieben. Anschließend werden die taxonomischen Unterschiede zweier Mitglieder der Familien der Hyperoliidae und der Arthroleptidae untersucht. Dies ebnet den Weg für die Makroökologie. Es wird analysiert, ob Westafrika eine einzigartige biogeographische Region ist. Die Untersuchung zeigen, dass Westafrika in der Tat einzigartig ist. Die Ähnlichkeiten innerhalb der Region sind größer als die innerhalb ähnlicher Habitate aus unterschiedlichen Regionen. Der Cross River ist die wichtigste Barriere. Mehrere geographische Zonierungen innerhalb Westafrikas werden entdeckt. Es wird untersucht, ob der Chytrid Pilz, Batrachochytrium dendrobatidis, (Bd), ein wichtiger Faktor beim Rückgang der Amphibien Populationen, in West Afrika vorkommt. Bisher gibt es keinen positiven Nachweis westlich Nigerias. Dennoch sagen Modelle geeignete Habitate für Bd vorher. Die wahrscheinlichste Erklärung ist, dass die Dahomey Gap als natürliche Barriere die Ausbreitung von Bd verhindert. Als letztes werden die Nischen westafrikanischer Amphibien eruiert. Für die meisten Arten werden Nischenmodelle berechnet. Dies bestätigt bereits bekannte Gebiete hoher Alpha Diversität und zeigt bisher unbekannte Gebiete auf. Des Weiteren werden Erklärungen für unterschiedliche Verbreitungsgebietsgrößen gesucht. Generell wird die Nischenbreite hierfür verantwortlich gemacht. Die vorliegenden Daten lassen allerdings auch den Schluss zu, dass das Ausbreitungsvermögen das beobachtete Muster ebenfalls erklären kann.Amphibian populations are declining globally. For informed conservation decisions a sound scientific background is needed. One major component is species distribution and the underlying causes. This also requires clarity on the taxonomic status. Often neglected regions are located in the tropics. In order to fill this gap, the present thesis examines the macroecology of West African amphibians. A new species of the family Phrynobatrachidae is described. Afterwards, the taxonomic differences between morphologically similar members of the families Hyperoliidae and Arthroleptidae are discussed. Beside other studies, this sets the field for macroecology. It is tested whether West Africa is a unique biogeographic region. The similarity of amphibian assemblages from Sub-Saharan Africa is analysed and it is shown that West Africa contains unique assemblages. Similarities within the region are higher than similarities between habitats across different regions. The main barrier towards Central Africa is the Cross River. Several geographic divisions within West Africa are detected. It is examined whether the chytrid fungus Batrachochytrium dendrobatidis (Bd), one important factor for amphibian population declines in many other regions, occurs in West Africa. So far there is no positive record west of Nigeria. However, models predict that environmental suitability for Bd is high. The most plausible explanation for the absence is that the Dahomey Gap acted as a natural barrier against the spread of the Bd. Finally, the niches of West African amphibians are investigated. For most species environmental niche models are calculated. This confirms previously known areas of high alpha diversity and so far unknown species rich areas are detected. In a further study, explanations for differing range sizes are searched for. Niche breadth is commonly assumed to be the general cause. However, the analysed data also suggests that dispersal ability can also explain the observed pattern.
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Bracamonte, Seraina Emilia. "Immune and metabolic processes jointly contribute to susceptibility to invasive parasites - The case of Anguillicola crassus in eels." Doctoral thesis, Humboldt-Universität zu Berlin, 2020. http://dx.doi.org/10.18452/21074.
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Die Einschleppung gebietsfremder Parasiten durch den Menschen ist einer der Hauptgründe für das Auftreten neuer Krankheiten in the letzten Jahrzehnten. Neue Wirte sind oftmals anfälliger für diese invasiven Parasiten als die ursprünglichen Wirte. In schwerwiegenden Fällen können invasive Parasiten zu Massensterben und zum Aussterben ihrer neuen Wirte führen. Der ursprüngliche Wirt des Aalparasiten Anguillicola crassus ist der Japanische Aal. In den frühen 1980er Jahren wurde der Parasit in die Population des Europäischen Aals eingeschleppt. Er ist einer der Faktoren, die für den Populationsrückgang des Europäischen Aals verantwortlich sind. Die molekularen Prozesse, die zur stärkeren Anfälligkeit des Europäischen Aals im Vergleich zum Japanischen Aal führen, sind noch nicht zureichend bekannt. Die Analyse transkriptomweiter differenzieller Genexpression von Immungewebe ergab, dass im Europäischen Aal sowohl Immun- als auch Nichtimmungene differenziell exprimiert waren. Dies war im Japanischen Aal nicht der Fall und deutet darauf hin, dass der Europäische Aal eine ineffiziente und kostspielige Immunantwort auslöst. Die Resultate ensprechen jenen die schon in anderen Wirbeltierwirt-invasiven Parasiten-Systemen beobachtet wurden. Ausserdem stützen diese Resultate die Hypothese, dass neuen Wirten eine wirksame Immunantwort fehlt und sie deuten darauf hin, dass Nichtimmunprozesse wesentlich zur höheren Anfälligkeit von neuen Wirten beitragen. Als Reaktion of die negativen Fitnesseffekte können neue Wirte Abwehrmechanismen entwickeln. Im Europäischen Aal entspricht das der Einkapselung von A. crassus. Einkapselung führte zu eine niedrigere Abundanz adulter A. crassus. Dies deutet darauf hin, dass das Einkapseln sich positiv auf die Gesundheit infizierter Aale auswirkt. Jedoch war die Abundanz zweier nativer Parasiten höher in Aalen, die A. crassus einkapselten. Eine verbesserte Abwehr des eingeschleppten Parasiten könnte daher die Abwehr nativer Parasiten beeinträchtigen.The human-mediated translocation of non-native parasites into foreign regions is one of the primary factors for the emergence of new diseases in recent decades. Novel hosts are often more susceptible to these invasive parasites than the native host. In severe cases, invasive parasites can lead to population declines and extinctions of their novel hosts. The eel parasite Anguillicola crassus is native to the Japanese eel. In the early 1980s it was introduced into the European eel population and is now considered to be one factor contributing to the population decline of its novel host. The underlying molecular processes determining higher susceptibility in the European eel compared to the Japanese eel are not well understood. Using whole-transcriptome differential gene expression analysis of immune organs, I found that genes involved in both immune and non-immune processes were differentially expressed in the European eel but not the Japanese eel, suggestive of an ineffective and costly immune response in the former. These results are in line with those observed between susceptible and resistant hosts in other vertebrate host-invasive parasite systems. Furthermore, the results support the hypothesis that novel hosts lack an effective immune response. The results also suggest that alteration of non-immune processes contributes substantially higher susceptibilities of novel hosts. In response to the negative fitness effects of invasive parasites, novel hosts can evolve coping mechanisms. The European eel has the capacity to encapsulate and kill A. crassus. Using natural infections, I found a lower abundance of adult A. crassus, the most costly parasitic stage in those eels encapsulating the parasite, suggesting that encapsulation can potentially improve health of infected eels. At the same time, the abundance of two native parasites was higher in those eels encapsulating A. crassus. Thus, coping with A. crassus may come at the expense of coping with native parasites.
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Murakaeva, Asiya. "Structure, evolution and expression of the duplicated growth hormone genes of common carp (Cyprinus carpio)." Doctoral thesis, Humboldt-Universität zu Berlin, Mathematisch-Naturwissenschaftliche Fakultät I, 2009. http://dx.doi.org/10.18452/15982.
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Der Karpfen, Cyprinus carpio, ist eine tetraploide Fischart aus der Familie Cyprinidae, die vor 20-50 Mio Jahren entstanden ist. Das Ziel der vorliegenden Arbeit war der Versuch, die funktionelle Rolle der duplizierten GH Gene des Karpfens durch das Studium ihrer Struktur, Evolution und Expression zu verstehen. Die Introns des zweiten GH Gens des Karpfens wurden erstmalig sequenziert und Sequenzvergleiche der kodierenden und nicht-kodierenden Bereiche von Allelen beider GH Gene wurden vorgenommen. Eine phylogenetische Analyse wurde durchgefuhrt, um die Beziehungen der GH Gene des Karpfens zu denen des tetraploiden Goldfischs und anderer diploider Cypriniden zu untersuchen. Zusatzlich wurden weitere duplizierte Gene des Karpfens, von denen einige auch fur das Wachstum von Bedeutung sind, phylogenetisch analysiert. Der Test der relativen Evolutionsrate nach Tajima (1993) zeigte einen statistisch signifikanten Anstieg der Evolutionsrate des GH I Gens beim Karpfen. Es wurden in der vorliegenden Arbeit einige weitere duplizierte Genpaare des Karpfens und Goldfischs gefunden, die ebenfalls eine Lockerung funktioneller Zwange oder sogar Beweise fur positive Darwin?sche Selektion bei einem der beiden Duplikate zeigen. Der Expressionstest hat gezeigt, dass die GH I und GH II Gene auf identischen Niveaus bei Karpfenbrut exprimiert werden, wahrend bei ein Jahr alten Karpfen, drei Jahre alten Mannchen und Weibchen sowie den 10 Monate alten, an kalte Temperaturen (2°C) angepassten Fischen die Expression von GH II statistisch signifikant geringer war als die von GH I. Es wurde eine neue und einfache Methode zur Herstellung von rekombinanten, biologisch aktiven GH-Proteinen ohne Notwendigkeit des Refolding entwickelt. Sie ermoglicht spatere Tests, ob die Aktivitat von unterschiedlichen GH-Varianten des Karpfens gleich oder unterschiedlich ist.The common carp, Cyprinus carpio, is a tetraploid fish species from the family Cyprinidae that arose about 20-50 Myr ago. The aim of the present work was attempting to understand the functional role of the duplicated common carp GH genes by studying their structure, evolution and expression. The introns of the second GH gene of common carp were sequenced for the first time and sequence comparisons of coding and non-coding regions of alleles of both GH genes were carried out. A phylogenetic analysis was done to examine the relationships of common carp GH genes with GH genes of the tetraploid goldfish and other diploid Cyprinids. In addition, phylogenetic analyses were done with other duplicated genes of common carp, some of which also important for growth. The relative rate test of Tajima (1993) showed a statistically significant increase in the evolution rate of the common carp GH I gene. In addition, some other duplicated gene pairs in common carp and goldfish with relaxation of functional constraints or even evidence of positive Darwinian selection in one of the two gene duplicates were found in the present study. The test of expression rates of the two GH genes has shown that the GH I and GH II genes were expressed at similar levels in carp fry. In contrast, the expression of GH II was statistically significantly lower than that of GH I in one year old carp, three years old males and females as well as in 10 months old fish adapted to cold temperature (2°C). To enable testing the hypothesis if activity of GH diverged between different GH variants of common carp a new and simple method for production of recombinant, biologically active GH proteins without the necessity of refolding was developed.
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Goorochurn, Ranesha. "Perte d'homogénéité du teint chez la femme à peau mature : approches biométrologique et cellulaire du lentigo actinique." Thesis, Besançon, 2016. http://www.theses.fr/2016BESA3002/document.
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La couleur de la peau chez un individu, appelée teint ou complexion, évolue au cours du temps et dépend de facteurs extrinsèques et intrinsèques. Une perte de son homogénéité est liée à l'apparition de lésions cutanées hyperpigmentées. Elles sont notamment provoquées par une exposition chronique au soleil et apparaissent avec l'âge, comme dans le cas du lentigo actinique. Si cette lésion hyperpigmentée bénigne est bien caractérisée à l'échelle macroscopique, peu d'études explorent ses fonctions cutanées grâce à des outils non invasifs. À l'échelle cellulaire et moléculaire, cette lésion hyperpigmentée bénigne résulte d'une altération du processus de pigmentation lors de la régulation du phénomène de photo-protection cutané. Si le modèle actuel d'une perte de cette régulation prend en compte l'altération du dialogue fonctionnel entre les couches épidermique et dermique, aucune étude ne décrit les caractéristiques fonctionnelles des cellules primaires extraites du lentigo actinique. Le premier objectif de mon projet a consisté en une exploration fonctionnelle du lentigo actinique par l'utilisation de divers paramètres biométrologiques. L'étude a été réalisée sur une cohorte de 80 femmes dont certaines présentent peu (grade 1) et, d'autres plusieurs, lentigosactiniques (grade 2) sur le visage. Après illustration du grade par une mesure photographique, différentes approches biométrologiques ont quantifié les taux de sébum, de mélanine, d'hémoglobine, d'hydratation, de réflexion de la lumière et de couleur (L *, a*, b* et lT A). Les résultats des analyses statistiques montrent que 1) la quantité de sébum discrimine les territoires cutanés de la joue et du front, 2) les taux de mélanine, d'hémoglobine, de réflexion de la lumière et de couleur sont différentiels entre les zones lésées (lentigo actinique) et non lésées, adjacentes au sein du territoire de la joue chez un volontaire, 3)que la diminution des taux de réflexion de la lumière et d'hémoglobine, ainsi que l'augmentation du taux d'hydratation, est observée au sein de la zone lésée entre les grades I et 2. L'ensemble de ces données ont mis en évidence certains paramètres biométrologiques comme indicateurs du territoire cutané, de la zone lésée vs non lésée et de l'évolution (grade 2 vs I) du lentigo actinique.Le second objectif a porté sur une analyse morphologique et fonctionnelle des fibroblastes primaires du lentigo actinique. L'étude a été réalisée sur une cohorte de 10 volontaires sur lesquels deux biopsies contenant les zones lésées et non lésées, adjacentes ont été prélevées. À partir de ces biopsies, les fibroblastes primaires humains ont été mis en culture. Une approche d'immunotluorescence révèle que les fibroblastes de lentigo actinique (FL) et ceux de la zone saine adjacente (FS) n'ont pas les mêmes caractéristiques morphologiques avec une organisation différentielle de leur cytosquelette d'actine. Une approche fonctionnelle montre que les FL ont une diminution de leur activité métabolique, de leur taux de prolifération et de leur capacité migratoire. À l'inverse, les FL sont dotés d'une augmentation de leur capacité sécrétoire en terme de facteurs solubles. Notre modèle in vitro de fibroblastes primaires (couples FL/FS), qui présentent des similitudes avec les caractéristiques décrites in vivo, représenterait un modèle cellulaire adéquat pour tester des principes actifs dont l'efficacité permettrait de réduire l'hétérogénéité du teint chez les femmes à peaux matures. Ces deux objectifs, qui ont été réalisés par des approches en recherche clinique et translationnelle, ont permis de mettre en évidence des indicateurs et des biomarqueurs du lentigoactinique qui permettront de mieux comprendre l'impact des facteurs intrinsèques et extrinsèques dans la perte d'homogénéité du teint liée au lentigo actiniqueBased on extrinsic and intrinsic factors, skin complexion of an individual evolves in time. The Joss of its homogeneity is linked to the appearance of hyperpigmented les ions. The latters are induced by chronic sun exposure and appear with the age, as in the solar lentigo disorder. Despite its well-known characterization at the macroscopic levels, only few studies explore the skin fonctions of the solar lentigo with non-invasive tools. At the cellular and molecular levels, this lesion results from an altered process of pigmentation that is involved in the regulation of the cutaneous photo-protection. Despite the changes of the functional dialogue between the epiderrnic and derrnic layers, no study describes the functional characteristics of primary ce lis isolated from the solar lentigo. The first aim of my project consisted on a functional exploration of the solar lentigo by the use of diverse biometrological parameters. The study was carried out on a cohort of 80 women, some of them had few (grade l) and others many solar lentiges (grade 2) on their faces. Thanks to photographie measurements to determine the grade, various biometrological approaches had quantified the rates of sebum, melanin, hemoglobin, moisturizing, light reflection and the colour (L *, a*, b* and 1T A). Results of the statistical analyses revealed that the quantity of sebumdiscriminates the skin territories of the cheek and forehead, 2) the rates of melanin, hemoglobin, light reflection and the colour were differential between affected (solar lentigo) and not affected zones, within the volunteers' cheek territory, and 3) decreased rates of light reflection and hemoglobin, as well as, increased rate moisturizing, were observed within the lesional zone between both grades. Altogether, our data highlighted some of the biometrological parameters, as indicators of the skin territory, the lesional vs non lesional areas and the progression (grade 2 vs 1) of solar lentigo The second aim covered morphological and functional analyses of the solar lentigo's primary fibroblasts. This study was carried out on a cohort of 10 volunteers and two biopsies, containing the peri-lesional and lesional areas, were taken from each person. From these biopsies, human primary fibroblasts were isolated and grown. An immunofluorescence approach revealed that the fibroblasts of solar lentigo (FL) and those from adjacent healthy areas (FS) did not depict similar morphological characteristics with a differential organization of their actin cytoskeleton. Functional approaches demonstrated that FL displayed decrease of their metabolic activity, theirproliferation rates and their migration capacity, compared to FS. On the contrary, FL showed increased secretion capacity in terms of soluble factors. Our in vitro mode! of primary fibroblasts(FL/FS), which showed similarities with in vivo fibroblast's characteristics, might be considered as an appropriate cellular mode! to test active principles targeting skin complexion heterogeneity in women with mature skin. Using clinicat and translational research approaches, both objectives highlighted indicators and biomarkers of the solar lentigo. This work contributed to better understand the impact of the intrinsic and extrinsic factors in the Joss of complexion homogeneitv
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Fanian, Ferial. "1-How in vivo cutaneous biometrology could demonstrate skin modifications induced by various methods. 2-In vitro evaluation of phenytoin on the morphology and activity of human primary melanocytes and in vivo repigmentation effect of topical phenytoin." Thesis, Besançon, 2016. http://www.theses.fr/2016BESA3008.
Full textAbstract:
La Biometrogie cutanée est un nouveau spectre de différentes méthodes d'évaluation qui permettent de mesurer les différents paramètres de la peau même en cas des petites modifications. Dans la première partie de nos travaux, nous avons étudié différentes capacités de ces méthodes afin de les corréler avec d'autres données cliniques et histologiques. Ces données nous ont encouragés à découvrir de plus en plus la pigmentation de la peau qui est un peu plus compliquée que les autres paramètres. Par conséquent, sur la deuxième partie, nous nous sommes concentrés sur la biologie cutanée en particulier sur la morphologie et l'activité des mélanocytes. Les travaux de cette thèse ont porté sur les effets de la phénytoïne sur les mélanocytes humains afin de savoir si cette molécule peut être un traitement efficace pour le vitiligo. Dans un premier temps, nous avons évalué deux concepts : tout d'abord et pour la première fois, les effets in vitro des différentes concentrations de phénytoïne sur la morphologie et l'activité des mélanocytes humains, et parallèlement, nous avons mis en place la méthode du transfert de mélanosomes sur les mélanocytes et des kératinocytes humains. Dans un deuxième temps, nous avons procédé à l'évaluation in vivo de la forme topique à différentes concentrations à l'aide d'une étude in vivo sur des cochons d'Inde noirs. Notre travail constitue une étape clé dans la compréhension des mécanismes d'action de la phénytoïne sur les mélanocytes humains qui contribuerait à l'amélioration des pratiques cliniques et donc à la qualité de vie des patients souffrant de troubles pigmentaireCutaneaous Biometrogy is a new vast spectrum of measuring methods wich provide the possibility to measure the différents parameteres of the skin even in the case of small changes. In the first part of this work, we studied various capabilities of these methods in order to correlates them with other clinical and histological data. These data encouraged us to discover more and more the skin pigmentation which is a little more complicated than the other parameters.So, on the second part, we concentrated more on cutaneaous biology particularily on the melanocytes morphology and activity.The work of this thesis focused on the effects of phenytoin on human melanocytes in order to know if this molecule can be eventually an available treatment for vitiligo.Fisrt, we evaluated two concepts : for the first time we evaluated the in vitro effects of the different concentrations of phenytoin on the morphology and activity of human melanocytes and, in parallel, we implemented the method of transfert of melanosomes on human melanocytes and keratinocytes.In a second step, the topical form of phenytoin at different concentrations was evaluated through an in vivo study on black ginea pigs.Our work is a key step on understanding the mechanisms of avtion of phenytoin on human melanocytes which would contribute to the improvement of clinical practices and therefore to the quality of life of patients suffering from depilatory disorders
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Ballegooy, Christoph van. "Endokrine Wirkungen (anti)androgener Substanzen bei der Ploetze (Rutilus rutilus)." Doctoral thesis, Humboldt-Universität zu Berlin, Mathematisch-Naturwissenschaftliche Fakultät I, 2008. http://dx.doi.org/10.18452/15743.
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Substanzen, die durch ihr hormonell wirksames Potenzial mit dem Hormonsystem interagieren und adverse Effekte auf die Reproduktion von Invertebraten und Vertebraten ausueben koennen, erlangten in den letzten Jahrzehnten große Aufmerksamkeit. Viele dieser Substanzen reduzieren die Fertilitaet oder die Fekunditaet, fuehren zu Abnormalitaeten in der Ontogenese oder im Verhalten der Tiere und haben Einfluss auf die Geschlechterverhaeltnisse. In der vorliegenden Arbeit wurden verschiedene Aspekte dieses Themengebietes bearbeitet. Das in Europa endemisch vorkommende Rotauge (Rutilus rutilus), ein Sueßwasserfisch, wurde als Modelltier fuer den Nachweis von (anti)androgenen Effekten auf aquatisch lebende Organismen etabliert. Zum Nachweis der (anti)androgenen Wirkmechanismen wurden die Tiere mit Modellsubstanzen aus drei verschiedenen Gruppen exponiert. Aus der Gruppe der Substanzen mit potenziell androgener Wirkung wurden Triphenylzinn (TPT) und Methyltestosteron (MT) verwendet, aus der Gruppe der Antiandrogene Vinclozolin (VIN) und Cyproteronazetat (CYP) und aus der Gruppe der Aromatasehemmer, und somit potenziell androgener Wirkung, Letrozol (LET) und Fenarimol (FEN). Feedbackmechanismen auf die Hypothalamus-Hypophysen-Gonaden-Achse (mRNA-Expression des Luteinisierenden Hormons, des Follikel stimulierenden Hormons und der Aromatase), mRNA-Expression potentieller Biomarker in der Leber (Androgen-Rezeptor-mRNA, Oestrogen-Rezeptor-mRNA), Sexsteroidspiegel im Blutplasma (17beta-Oestradiol und 11-keto-Testosteron), Enzymaktivitaeten im Gehirn (Aromatase), Histologie der Gonaden, Totallaenge, Gewicht und Geschlechterverteilung wurden als Endpunkte analysiert, um adverse Effekte auf die Reproduktionsbiologie von R. rutilus zu zeigen. Die untersuchten Endpunkte eigneten sich sehr gut zum Nachweis verschiedener Wirkmechanismen.Substances that are able to interact with the endocrine system and cause adverse effects on the reproduction of invertebrates and vertebrates have gained much attention over the last few decades. Many of these substances reduce fertility or fecundity, lead to developmental abnormalities or abnormalities in the behaviour of animals and have an impact on sex ratios. The present study examines various aspects of these topics. The roach (Rutilus rutilus), a freshwater fish endemic in Europe, was established as a model animal for the detection of (anti)androgenic effects on aquatic organisms. For examination of the (anti)androgenic action, the animals were exposed to model compounds from three different groups: triphenyltin (TPT) and methyltestosterone (MT) from the group of substances with potentially androgenic effect, vinclozolin (VIN) and cyproteronacetate (CYP) from the group of antiandrogens, and letrozol (LET) and fenarimol (FEN) from the group of aromatase inhibitors, which thus have a potentially androgenic effect. Feedback mechanisms on the hypothalamus-pituitary-gonad-axis (mRNA expression of luteinising hormone, follicle stimulating hormone and aromatase), mRNA expression of potential biomarkers in the liver (androgen receptor mRNA, oestrogen receptor mRNA), steroid levels in the blood plasma (17beta-oestradiol and 11-ketotestosterone), enzyme activity in the brain (aromatase), histology of the gonads, total length, weight and sex ratios were analysed as endpoints to show adverse effects on the reproductive biology of R. rutilus. The studied endpoints are suitable for the detection of different modes of action. The histological examination of the gonads proved to be especially sensitive with the exposure to AACs to resulting in fundamental adverse damages to the gonads. It was ascertained that - in the early stages of ontogeny - androgens play as crucial of a role in the development of the gonads as previously attributed primarily to oestrogens.
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Heu, Céline. "Vieillissement des barrières biologiques. : caractérisation morphologique et fonctionnelle d'un modèle de stress environnemntal induit chez la lignée kératinocytaire humaine HaCat." Thesis, Besançon, 2012. http://www.theses.fr/2012BESA0005.
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II existe de nombreuses études mettant en relation le vieillissement et le stress oxydant, mais peu d'entre elles ont caractérisé l'évolution des marqueurs des défenses antioxydantes, notamment au niveau cutané, au cours du vieillissement dit extrinsèque ou environnemental.Nous avons cherché à mimer in vitro le vieillissement extrinsèque cutané, à partir d'un modèle de cellules épidermiques en culture, la lignée de kératinocytes humains HaCaT, soumises à un stress chimique, l'exposition au glyphosate, un principe actif entrant dans la composition de nombreuses formulations pesticides. Ainsi, nous avons exploré notre modèle par une approche multi-échelle originale et innovante: tout d'abord, à l'échelle moléculaire, par une étude protéomique quantitative différentielle des taux d'expression protéique intracytosolique suite à l'induction du stress ; puis, à l'échelle cellulaire en cytomètrie en flux, par la caractérisation fonctionnelle du stress oxydant et de la mort cellulaire qui en découle ; enfin, à l'échelle micro- et nanométrique, en microscopie confocale et à force atomique, par le suivi de l'évolution des propriétés morphologiques et viscoélastiques des kératinocytes stressés.Ce travail de thèse a démontré que le glyphosate altérait signifïcativement l'état et la fonction barrière de l'épiderme humain, ciblant notamment les kératinocytes, dont l'équipement moléculaire et les fonctions vitales d'adhérence et de dynamique membranaire se retrouvent fondamentalement dégradées. L'ensemble de ces résultats constitue un « tableau » qui évoque parfaitement les événements, les signaux et les comportements cellulaires s'installant au cours du vieillissement cutanéNumerous studies relate ageing to oxidative stress. Few of them described thé évolution of markers of antioxidant défenses, in particular at thé cutaneous level, during extrinsic or environmental ageing. We tried to mimic in vitro cutaneous extrinsic ageing, with a model of epidermic cells in culture, thé human kératinocytes cell line HaCaT, subjected to a chemical stress, Glyphosate, an active ingrédient présent in thé composition of numerous pesticide formulations. Indeed, we examined thé effects of induced ageing in thé loss of kératinocytes integrity in culture, by an original and innovative multi-scale approach: Firstly, at thé molecular scale, we assessed thé stress induced modifications of intracytosolic protein expression by a differential quantitative proteomic study; then, at thé .cellular scale, with flow cytometry, by thé functional characterization of thé oxidative stress and resulting cell death; fmally, at thé micro- and nanoscale, with confocal and atomic force microscopy by thé following thé évolution of morphological and viscoelastic properties of stressed kératinocytes. This PhD work demonstrated that glyphosate impaired thé state and thé barrier function of thé human skin, in particular by fundamentally impairing kératinocytes through thé molecular equipment, thé vital adhésion fonctions and membrane dynamics. Ail thèse results give us a global image of events, signais and cell behavior occurring in skin aging
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Demonchaux, Patrice. "Recherche d'agents radioprotecteurs : synthèse et mécanisme d'action de composés de type intercalant-aminothiol." Grenoble 1, 1988. http://www.theses.fr/1988GRE10016.
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Les intercalants utilises sont des amino-9 chloro-6 methoxy-2 acridines des amino-4 chloro-7 quinoleines et des amino-4 chloro-7 methyl-1 quinoleiniums sur lesquels ont ete introduites des chaines analogues a celles de la cysteamine et du wr 2727; etude de l'affinite de ces composes avec l'adn
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Mihailovic, Katarina. "Visions of 1968: Radical Aesthetics in Porcile, WR and Tout va bien." Thesis, 2011. http://spectrum.library.concordia.ca/7453/1/Mihailovic_MA_S2011.pdf.
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In my thesis, I examine the responses of four politically radical filmmakers—Jean-Luc Godard and Jean-Pierre Gorin, Dušan Makavejev, and Pier Paolo Pasolini—to their cultural, ideological and theoretical contexts. I am particularly interested in the filmmakers’ respective conceptions of the politically radical work of art and their understanding of the role of the politically committed intellectual in the aftermath of the 1968 movement. I undertake an analysis of Godard's and Gorin’s Tout va bien (All’s Well, 1972), Makavejev's WR:Misterije organizma (WR: Mysteries of the Organism, 1968-71), and Pasolini's Porcile (Pigsty, 1969), in light of the filmmakers’ political modernist projects. The first chapter establishes the cultural and political contexts in which the filmmakers worked. I pay close attention to the intellectual debates in France, Yugoslavia and Italy that shaped the directors’ understanding of the role of the committed intellectual and the social and political function of art. The second chapter discusses their respective "returns" to the avant-garde aesthetics of Sergei Eisenstein and Bertolt Brecht. I examine Godard-Gorin’s, Makavejev’s and Pasolini’s use of the montage and collage techniques. The third chapter examines understanding of revolution and revolt, highlighting the directors’ different ideological and political positions.
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Lee, Alan Yueh-Luen, and 李岳倫. "Function-Structural Studies on the Lon Protease from Brevibacillus thermoruber WR-249." Thesis, 2004. http://ndltd.ncl.edu.tw/handle/37143254234545757149.
Full textAbstract:
博士國立臺灣大學
生化科學研究所
92
Protein quality control plays key roles in prokaryotic and eukaryotic cells by depicting cellular surveillance systems of structural and functional integrity of proteins inside a cell. Oligomeric ATP-dependent proteases consisting of the chaperone and the protease machinery carry out such quality control. These energy-dependent proteases are especially important under stress conditions because increasing amounts of misfolding and damaged proteins may accumulate during various stresses. A thermostable Lon protease from Brevibacillus thermoruber WR-249 (Bt-Lon) has been cloned and characterized. The Br. thermoruber Lon gene (Bt-lon) encodes an 88-kDa protein characterized with an N-terminal domain, a central ATPase domain including an SSD (sensor- and substrate- discrimination) domain, and a C-terminal protease domain. The Bt-lon is a heat-inducible gene and may be controlled under a putative Bacillus subtilis sA-dependent promoter but in the absence of CIRCE (controlling inverted repeat of chaperone expression). Bt-lon was expressed in E. coli and its protein product was purified. Bt-Lon is a multi-functional enzyme and its functions include the degradation of proteins, ATPase and chaperone-like activities, and DNA binding. The optimal temperature of ATPase activity for Bt-Lon is at 70oC, while the optimal temperature of peptidase and DNA-binding activities is 50oC. The peptidase activity of Bt-Lon increases substantially in the presence of ATP. Furthermore, the substrate specificity of Bt-Lon was found to be different from that of E. coli Lon by using fluorogenic peptides as substrates. Notably, this Bt-Lon protein shows the chaperone-like activity by preventing aggregation of denatured insulin B chain in a dose-dependent and ATP-independent manner. In the thermal denaturation experiments, Bt-Lon was found to display an indicator of thermostability value, Tm of 71.5 oC. Sequence comparison with a mesophilic Lon protease shows differences in the rigidity, electrostatic interactions or hydrogen bonding of Bt-Lon relevant to thermostability. Additionally, the native Br. thermoruber Lon protease (Bt-Lon) showed a hexameric structure as revealed by analytical gel filtration chromatography, and its nature of oligomerization was investigated. The chemical crosslinking experiments revealed that the oligomerization of Bt-Lon proceeds through a dimer « tetramer « hexamer assembly model. Our results also showed that hydrophobic interactions may play important roles in the dimerization of Bt-Lon and that ionic interactions are mainly responsible for hexamer assembly. To identify the roles of individual domains in the oligomerization process and the functional activities, seven truncated mutants of Bt-Lon were designed, expressed and purified. We examined the Bt-Lon mutants using assays that reflect five different aspects of Bt-Lon activity: ATP-independent oligomerization, ATP-dependent proteolysis, ATPase activity, chaperone-like activity, and DNA-binding activity. Our results show that the N-terminal domain is essential for the oligomerization. The truncation of N-terminal domain resulted in the failure of oligomerization and led to the inactivation of proteolytic, ATPase and chaperone-like activities, suggesting that oligomerization of Bt-Lon is a prerequisite for its catalytic and chaperone-like activities. However, the N-terminal region of Bt-Lon is not involved in the interaction with DNA. We further found that the SSD domain with a previously uncertain function is involved in DNA-binding based on gel mobility shift assays (GMSA).
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Huang, Dai-Po, and 黃岱柏. "Function-Structural Studies on the Lon Protease from Meiothermus taiwanensis WR-220." Thesis, 2010. http://ndltd.ncl.edu.tw/handle/24033059837659209408.
Full textAbstract:
碩士臺灣大學
生化科學研究所
98
The Lon proteases had been known as one of the most evolutionarily conserved proteins. According to previous findings, Lon proteases possessed ATPase, protease, peptidase and chaperone activities. Based on these multi-functional Lon proteases, the protein quality control system and the regulation of metabolic process could both work well. In this study, the function-structural characterizations among Mt-LonA1, Mt-LonA2 and Mt-TTC1975 from Meiothermus taiwanensis would be juxtaposed to express the contrast. The Lon protease family could be divided into two subfamilies, LonA and LonB, mainly based on the sources and the domain structures of these proteins. The LonA consisted of a variable N-terminal domain (N domain), a central ATPase domain (A domain), and a C-terminal protease domain (P domain) on a single polypeptide. Depending on the analysis of primary structures of Mt-LonA1, Mt-LonA2 and Mt-TTC1975, This study considered that Mt-LonA1 and Mt-LonA2 both should be classified as the LonA subfamily, for Mt-LonA1 and Mt-LonA2 both possessed the classical LonA-type domains. For Mt-TTC1975, it only possessed a high similarity in protease domain with canonical LonA. Therefore, it should not be classified as the Lon protease. Structural characteristic results by circular dichroism showed that Mt-LonA1, Mt-LonA2 and Mt-TTC1975 possessed mostly α-helical secondary structures and they all possesed well-defined three-dimensional structures. For quaternary structures, the AUC data, Native-PAGE and EM graph revealed that Mt-LonA1 functions mainly as a hexamer; the AUC data and Native-PAGE revealed that Mt-LonA2 might function as a mixture of dimer and pentamer; Native-PAGE revealed that Mt-TTC1975 functions as a hexamer or a heptamer. Functional characteristic results showed that Mt-LonA1 exhibited the ATPase, protease, peptidase and chaperone activity; Mt-LonA2 exhibited the ATPase, protease, peptidase and DNA-binding activity; Mt-TTC1975 exhibited the chaperone activity only. Lastly, the comparison of primary structure of α-domains and the results of homology modeling suggested that the K527 residue and the K-K-R conserved region of Mt-LonA2 might critically influence the DNA-binding activity.
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Aldoretta, Emily. "A study of the large-scale structure of the wind of WR 134." Thèse, 2015. http://hdl.handle.net/1866/13673.
Full textAbstract:
Diverses méthodes ont été utilisées pour étudier les étoiles Wolf-Rayet (WR) dans le but de comprendre les phénomènes physiques variés qui prennent place dans leur vent dense. Pour étudier la variabilité qui n'est pas strictement périodique et ayant des caractéristiques différentes d'une époque à l'autre, il faut observer pendant des périodes de temps suffisamment longues en adopter un échantillonnage temporel élevé pour être en mesure d'identifier les phénomènes physiques sous-jacents. À l'été 2013, des astronomes professionnels et amateurs du monde entier ont contribué à une campagne d'observation de 4 mois, principalement en spectroscopie, mais aussi en photométrie, polarimétrie et en interférométrie, pour observer les 3 premières étoiles Wolf-Rayet découvertes: WR 134 (WN6b), WR 135 (WC8) et WR 137 (WC7pd + O9). Chacune de ces étoiles est intéressante à sa manière, chacune présentant une variété différente de structures dans son vent. Les données spectroscopiques de cette campagne ont été réduites et analysées pour l'étoile présumée simple WR 134 pour mieux comprendre le comportement de sa variabilité périodique à long terme dans le cadre d'une étude des régions d'interactions en corotation (CIRs) qui se retrouvent dans son vent. Les résultats de cette étude sont présentés dans ce mémoire.Wolf-Rayet stars have been studied using various methods in order to understand the many physical phenomena taking place in their dense outflows. In the case of variability that is not strictly periodic or for epoch-dependant changes, the challenge is to observe for su fficiently long periods of time and with a high enough time sampling to be able to understand the underlying phenomena. During the summer of 2013, professional and amateur astronomers from around the world contributed to a 4-month campaign, mainly in spectroscopy but also in photometry, polarimetry and interferometry, to observe the fi rst 3 Wolf-Rayet stars discovered: WR 134 (WN6b), WR 135 (WC8) and WR 137 (WC7pd+O9). Each of these stars are interesting in their own way, showing a variety of stellar wind structures. The spectroscopic data from this campaign have been reduced and analyzed for the presumably single star WR 134 in order to better understand its behavior and long-term periodicity in the context of corotating interaction regions (CIRs) in the wind. The results of this study are presented in this thesis.
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Eklund, Gerd. "Vrist - brist - rist : Utvecklingen av gammalt uddljudande wr i nordiska, särskilt svenska, dialekter." Doctoral thesis, 1991. http://urn.kb.se/resolve?urn=urn:nbn:se:sprakochfolkminnen:diva-328.
Full textAbstract:
The Germanic initial sound combination wr (e.g. in *wrītan 'write') has not been preserved in any standard language. In the Scandinavian languages the development of this sound combination has resulted in five different initial sounds or sound combinations, namely rw, r, w, br and vr. The aim of this study is to describe the occurrence of these sound combinations, and to explain their age and origin. A limited number of words, mainly from Swedish dialects, has been investigated. The Swedish material has been assembled in a collection that has largely also been mapped, and so has a collection of Norwegian dialect material. The result shows that br is frequent in the Swedish dialects and that it also occurs in Trøndelagen and Østlandet in Norway, and on Jutland. R is widespread in Norway and occurs in Sweden in some words in Norrland, Dalarna, Värmland, Dalsland, Uppland and on the island of Gotland. Rw has been documented in Upper Dalarna, and w in the same area, as well as in the Kalix dialect in northernmost Sweden. The author demonstrates that the Norwegian loss of w might have started already in the 6th century in western Norway. The loss on Gotland is independent and can be demonstrated in Old Gutnish. The metathesis rw is found in Swedish and Norwegian 13-14th century sources from Uppland, Västmanland, Östergötland and southeastern Norway. The developments wr > r and wr > rw probably have their roots in a difference between the west Norwegian wr and the east Norwegian and Swedish war which is documented from PrimScand times. W is a secondary development of rw. The change wr > br can be dated by place-name material to the early 15th century. The change wr > vr appears to have taken place at approximately the same time. The author demonstrates that the result, wr > br or wr > yr, is apparently governed by certain phonetic factors. The failure of the Germanic wr to survive depends on the combination being phonetically complex. The risk that w would be lost was therefore considerable. However, differentiating forces worked for its retention. All developments emanating from wr, apparently disparate, can be seen as features of a larger process where a general linguistic tendency towards a weakening of sounds is confronted by conservative forces, with the above results as a consequence.Doktorsavhandling vid Uppsala universitet 1991
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Lin, Yu-Ching, and 林宇慶. "DNA-binding specificity of the Lon protease α-domain from Brevibacillus thermoruber WR-249." Thesis, 2010. http://ndltd.ncl.edu.tw/handle/04158306371001020663.
Full textAbstract:
博士臺灣大學
生化科學研究所
98
The multi-functional, homo-oligomeric, ATP-dependent Lon protease is highly conserved in prokaryotes and eukaryotic organelles. Previous studies have shown that Lon activity is essential for protein quality control and regulation of metabolic processes. Here we examined the DNA-binding activity of the Lon protease α-domains from Brevibacillus thermoruber, Bacillus subtilis, and Escherichia coli. Gel mobility shift assays indicated that the α-domain from Br. thermoruber has the highest DNA affinity. MALDI-TOF mass spectrometry showed that this α-domain binds to the nucleotide sequence 5’-CTGTTAGCGGGC-3’ (ms1). Surface plasmon resonance and isothermal titration calorimetry showed that a double-stranded DNA fragment of this sequence binds to the α-domain; double-stranded DNA fragments with 0 and 50% identity to the binding sequence had lower affinities for the α-domain. Five mutants of the α-domain from Br. thermoruber carrying single mutations (R537A, R546A, R553A, K580A and R584A) were constructed and showed only 1.2–2.0-fold lower DNA binding affinity; one mutant, R518A, displayed 26-fold lower affinity. The Bt-Lon R518A mutant also has lower affinity to DNA than wild type. These results revealed that Arg 518 of the Bt-Lon from Br. thermoruber plays a critical role in the DNA-binding activity.
46
Hénault-Brunet, Vincent. "Étude de l’étoile Wolf-Rayet variable WR 46 dans l’ultraviolet lointain et les rayons X." Thèse, 2009. http://hdl.handle.net/1866/3208.
Full textAbstract:
L’étoile Wolf-Rayet WR 46 est connue pour sa variabilité complexe sur des échelles de temps relativement courtes de quelques heures et sur des échelles de temps plus longues de plusieurs mois. Des décalages périodiques mais intermittents en vitesse radiale ont déjà été observés dans
ses raies d’émission optiques. Plusieurs périodes photométriques ont aussi été mesurées dans le passé. Des pulsations non-radiales, une modulation liée à la rotation rapide, ou encore la présence d’un compagnon de faible masse dont la présence reste à confirmer ont été proposées pour expliquer le comportement de l’étoile sur des échelles de temps de quelques heures. Dans un effort pour dévoiler sa vraie nature, nous avons observé WR 46 avec le satellite FUSE sur plusieurs cycles de variabilité à court terme. Nous avons trouvé des variations sur une échelle de temps d’environ 7,5 heures dans le continu ultraviolet lointain, dans l’aile bleue de la
composante d’absorption du profil P Cygni du doublet de O vi 1032, 1038, ainsi que dans la
composante d’absorption du profil P Cygni de S vi 933, 944. Nous avons également récupéré
des données archivées de cette étoile obtenues avec le satellite XMM-Newton. La courbe de lumière en rayons X montre des variations sur une échelle de temps similaire aux courbes de lumière du continu ultraviolet et ultraviolet lointain, et le spectre rayons X de WR 46 est très mou avec un pic d’émission à des énergies plus faibles que 1 keV. Nous discutons des différentes contraintes sur la nature de la variabilité de cette étoile que ces nouvelles observations aident à poser. Parmi les scénarios suggérés, nous concluons que celui des pulsations non-radiales est le plus probable, bien que nous soyons encore loin d’une compréhension détaillée de WR 46.The Wolf-Rayet star WR 46 is known to exhibit a very complex variability pattern on relatively short timescales of a few hours and also on longer timescales of months. Periodic but intermittent radial velocity shifts of optical lines as well as multiple photometric periods have been found in the past. Nonradial pulsations, rapid rotational modulation or the presence of a yet-to-be-confirmed low-mass companion have been proposed to explain the short-term behaviour. In an effort to unveil its true nature, we observed WR 46 with FUSE over several short-term variability cycles. We found significant variations on a timescale of about 7.5 hours in the FUV continuum, in the blue edge of the absorption trough of the O vi 1032, 1038 doublet P Cygni profile, and in the S vi 933, 944 P Cygni absorption profile. We also retrieved archival XMM-Newton data of this star. We found the X-ray light-curve to show variations on a timescale similar to the UV and FUV continuum light-curves, and the X-ray spectrum of WR 46 to be very soft with a peak below 1 keV. We discuss the different constraints on the nature of the variability that these new observations help to establish. Among the suggested scenarios, we conclude that non-radial pulsations is the most likely, although we are far from a complete picture.
47
Huang, Shiue-Fang, and 黃雪芳. "Function-Structure Studies on the isolated Domains of Lon Protease from Meiothermus taiwanensis WR-220." Thesis, 2012. http://ndltd.ncl.edu.tw/handle/14238444582167160882.
Full textAbstract:
碩士國立臺灣大學
生化科學研究所
100
ATP-dependent Lon protease has been known as one of the most evolutionarily conserved proteins in living organisms, which is a homo-oligomeric multi-domain enzyme. Lon proteases are divided into two subfamilies, LonA and LonB. Each possesses both ATPase domain, belonging to the AAA+ superfamily and a proteolytic domain (P-domain) with a serine-lysine catalytic dyad. The difference between LonA and LonB is that LonA contains a large N-terminal domain, whereas LonB has a transmembrane domain that anchors the protein to the membrane. Lon proteases are well-known to regulate the metabolic processes and involve in protein quality control system. In this study, we analyzed the primary sequence of MtaLonA1 (793 a.a) and MtaLonA2 (815 a.a) from Meiothermus taiwanensis (WR-220) and constructed the truncated-domain MtaLonA1N (1-312 a.a), MtaLonA1A (313-585 a.a), MtaLonA1α (492-585 a.a), MtaLonA1C (586-793 a.a), MtaLonA1NA (1-585 a.a), MtaLonA1AC (313-793 a.a), MtaLonA2N (1-320 a.a), MtaLonA2A (321-601 a.a), MtaLonA2α (508-601 a.a), MtaLonA2C (602-815 a.a), MtaLonA2NA (1-601 a.a) and MtaLonA2AC (321-815 a.a). MtaLonA1, MtaLonA2 and their truncated proteins are overexpressed and purified to examine the functional and structural properties. The structural characteristic presented by circular dichroism revealed that all constructs were composed of α-helical as the major secondary structures and all possessed well-defined three-dimensional structures. For quaternary structure, MtaLonA1 reveals mainly as hexamer and MtaLonA2 might be as tetramer. In native-PAGE, MtaLonA1N-, A1NA- and MtaLonA2N-, A2NA-domain exhibited polymeric structures. Functional studies demonstrated that MtaLonA1 shows the protease, peptidase, ATPase and chaperone-like activities; whereas MtaLonA2 shows the protease, ATPase, DNA-binding activity and weaker chaperone-like activities than that of MtaLonA1. Among the truncated proteins of MtaLonA2, only MtaLonA2N (N-domain) shows no DNA-binding activity, and the MtaLonA2α-domain) reveals weaker DNA-binding capability compared to MtaLonA1α. Particularly, MtaLonA2AC has peptidase activity, protease activity, but only slight ATPase activity. MtaLonA1N-, MtaLonA1NA-, MtaLonA2N- and MtaLonA2NA domain have chaperone-like activities. These results suggested that N-terminal sequence is essential for oligomerization and chaperone-like activities. We found out the substrate, MtaHU β is specific to the MtaLonA2. Based on these results, we propose that MtaLonA1 and MtaLonA2 may have different functions and it is important to find out the specific natural substrates and crystallize structures of full-length enzymes.
48
Lee, Huai-Cheng. "In vitro Identification and Characterization of DNA Sequences Bound by Brevibacillus thermoruber WR-249 Lon Protease." 2005. http://www.cetd.com.tw/ec/thesisdetail.aspx?etdun=U0001-2306200515192100.
Full text
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Chen, Yu-Da, and 陳昱達. "Elucidation of DNA Recognition Mode for the Lon Protease α-domain from Brevibacillus thermoruber WR-249." Thesis, 2011. http://ndltd.ncl.edu.tw/handle/03258302625355859819.
Full textAbstract:
碩士國立臺灣大學
生化科學研究所
99
Lon protease is a multifunctional enzyme, and it’s functions include the degradation of damaged proteins, ATPase, and chaperone-like activities. It is highly conserved in prokaryotes and eukaryotic organelles. Our previous studies demonstrate the DNA binding ability as a novel function for a thermostable Lon protease from Brevibacillus thermoruber WR-249. However, the physiological role and structure of DNA binding by Lon was still poorly understood. Bioinfomatic analysis reveals that the α-domain of Bt-Lon should be a new member of DNA binding domains with an uncharacterized recognition mode. With the aim of elucidating the DNA recognition mode of Bt-Lon, NMR technique and protein crystallography were employed to determine the structures of free and DNA-bound forms of α-domain. The α-domain was crystallized by the sitting drop, vapor diffusion method. X-ray diffraction data was collected at a synchrotron-radiation source and belonged to space group P23 , with unit cell parameters a = b = c = 93.8 Å , α = 90°, β = 90° , γ = 90° . The Bt-Lon α-domain contains four α helices and two parallel β strands and resembles similar domains found in a variety of ATPases. NMR chemical shift perturbation experiments suggest that there are three major sites responsible for DNA binding : (1) α4 ; (2) the loop between α1 and β1 ; (3) and the loop between α3 and β2. The feasible model of protein-DNA complex was docking with HADDOCK software based on the mutation and NMR perturbation data.
50
Lee, Huai-Cheng, and 李懷正. "In vitro Identification and Characterization of DNA Sequences Bound by Brevibacillus thermoruber WR-249 Lon Protease." Thesis, 2005. http://ndltd.ncl.edu.tw/handle/38970824198741829342.
Full textAbstract:
碩士國立臺灣大學
生化科學研究所
93
Proteins with DNA-binding activity mostly play an important role in the gene expression of a cell. This kind of proteins appears to exert its regulatory function by degrading some transcription factors after it binds to DNA. To investigate what kinds of elements bound by the DNA-binding proteins, identification of the binding site of the DNA must be achieved. A thermostable Lon protease from Brevibacillus thermoruber WR-249 (Bt-Lon) has been cloned and characterized with an N-terminal domain, a central ATPase domain including a SSD (sensor- and substrate- discrimination) domain, and a C-terminal protease domain. Bt-Lon is a multi-functional enzyme and its functions include the degradation of proteins, ATPase, chaperone-like activities, and DNA binding. Gel mobility shift assays revealed that Bt-Lon binds to DNA cooperatively. In line with the previous result, we demonstrated that SSD domain is involved in the DNA-binding activity by recruiting a truncated mutant, Bt-Lon-C289. It was also found that Bt-Lon, as well as the E.coli and human Lon, exhibits a high affinity to the TG-rich DNA. To further investigate whether Bt-Lon binds DNA specifically, DNA fragments bound by Bt-Lon were purified and then subjected to MS analysis and sequence determination by cloning/sequencing on the vector (pCR4Blunt-TOPO). Experimental data revealed that the five fragments bound by Bt-Lon from plasmid pET28a were homologous in sequence with the elements bound by E. coli and human Lon. Furthermore, we selected and cloned the five fragments, encompassing ms1, ms2, lb1, lb2 and lb3 by PCR amplification. Based on the high affinity of these five fragments to Bt-Lon, it is suggested that Lon binds to DNA dependent on the site-specific TG-rich DNA sequences, and the secondary or tertiary structure of the plasmid DNA can enhance the DNA-binding affinity of Bt-Lon.