Dissertations / Theses on the topic 'SEC Regulations'
To see the other types of publications on this topic, follow the link: SEC Regulations.
Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles
Consult the top 50 dissertations / theses for your research on the topic 'SEC Regulations.'
Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.
You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.
Browse dissertations / theses on a wide variety of disciplines and organise your bibliography correctly.
1
Palma, Kelly. "Hedge funds and the SEC regulation of Hedge Fund Advisers : /." Staten Island, N.Y. : [s.n.], 2006. http://library.wagner.edu/theses/business/2006/thesis_bus_2006_palma_hedge.pdf.
Full text
2
Faribault, Christian. "Should Ontario adopt a regulation similar to the SEC Regulation FD to counter selective disclosure?" Thesis, National Library of Canada = Bibliothèque nationale du Canada, 2001. http://www.collectionscanada.ca/obj/s4/f2/dsk3/ftp05/MQ63301.pdf.
Full text
3
Liu, Zhenfeng. "The Effect of Shortened Reporting Lag on the Usefulness of Form 20-F." FIU Digital Commons, 2016. http://digitalcommons.fiu.edu/etd/2530.
Full textAbstract:
This study examines the impact of the Securities and Exchange Commission’s (SEC) decision to accelerate the Form 20-F (20-F) filing deadline on the usefulness of 20-Fs. I find that only the large and medium firms experienced a significant increase in market reaction when they accelerated their 20-F filing deadlines to four months after the year-end, while no significant change in market reaction is detected for small firms. I also find that the market did not appear to have reacted to firms who voluntarily further shortened their 20-F reporting lag to less than four months after the year-end. Finally, I find that firms that comply with the SEC’s policy to shorten the 20-F filing deadlines are more likely to restate the financial statements, but the 20-F readability and the possibility of amending their 20-Fs do not seem to be different, compared to the matched non-acceleration firms. Taken together, this study provides consistent evidence suggesting that the “four-month” 20-F filing deadline is beneficial for larger firms while causing no burdens to small firms, and that the accelerated 20-F filing deadline may increase the timeliness of 20-Fs at the expense of the reporting quality.
4
Kadri, Sabah. "miRNA Regulation in Development." Research Showcase @ CMU, 2012. http://repository.cmu.edu/dissertations/186.
Full textAbstract:
microRNAs (miRNAs) are small (20-23 nt), non-coding single stranded RNA molecules that play an important role in post-transcriptional regulation of protein-coding genes. miRNAs have been found in all animal lineages, and have been implicated as critical regulators during development in multiple species. The echinoderms, Strongylocentrotus purpuratus (sea urchin) and Patiria miniata (sea star) are excellent model organisms for studying development due to their well-characterized transcriptional gene networks, ease of working with their embryos in the laboratory and phylogenetic position as invertebrate deuterostomes. Literature on miRNAs in echinoderm embryogenesis is limited. It has been shown that RNAi genes are developmentally expressed and regulated in sea urchin embryos, but no study in the sea urchin has examined the expression of miRNAs.
The goal of my work has been to study miRNA regulation in echinoderm developmental gene networks. I have identified developmentally regulated miRNAs in sea urchin and sea star embryos, using a combination of computational and wet lab experimental techniques. I developed a probabilistic model (named HHMMiR) based on hierarchical hidden Markov models (HHMMs) to classify genomic hairpins into miRNA precursors and random stem-loop structures. I then extended this model to make an efficient decoder by introduction of explicit state duration densities. We used the Illumina Genome Analyzer to sequence small RNA libraries in mixed stage population of embryos from one to three days after fertilization of S. purpuratus and P. miniata. We developed a computational pipeline for analysis of these miRNAseq data to reveal the miRNA populations in both species, and study their differential expression. We also used northern blots and whole mount in situ hybridization experimental techniques to study the temporal and spatial expression patterns of some of these miRNAs in sea urchin embryos. By knocking down the major components of the miRNA biogenesis pathway, we studied the global effects of miRNAs on embryo morphology and differentiation genes. The biogenesis genes selected for this purpose are the RNAse III enzyme, Dicer and Argonaute. Dicer is necessary for the processing of mature miRNAs from hairpin structures while Ago is a necessary part of the RISC (RNA interference silencing complex) assembly, which is required for the miRNA to hybridize to its target mRNA site. Knocking down these genes hinders normal development of the sea urchin embryo and leads to loss of the larval skeleton, a novel phenotype not seen in sea stars, as well as abnormal gastrulation. Comparison of differentiation gene marker expression between control and Ago knocked down sea urchin embryos shows interesting patterns of expansion and suppression of adjoining some embryonic territories, while ingression of larval skeletogenesis progenitors does not occur.
5
Kashani, Hossein. "Government intervention and efficiency in the North Sea petroleum industry." Thesis, University of Surrey, 2000. http://epubs.surrey.ac.uk/804404/.
Full text
6
Hochscheid, Sandra. "Thermoregulation, metabolism and buoyancy regulation in sea turtles." Thesis, University of Aberdeen, 2003. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.288349.
Full textAbstract:
1. This study was performed to investigate a mechanism of heat exchange in sea turtles and how temperature and different acclimation time affects their metabolic rates. In another part of this thesis I aimed to test the possibility of a correlation between dive duration and both metabolic rate and state of buoyancy known to be regulated via the gas volume in the lungs of Chelonian sea turtles. 2. All experiments were conducted on captive loggerhead (Caretta caretta) and green turtles (Chelonia mydas) housed in a individual tanks with circulating seawater from the adjacent Gulf of Naples (Western Mediterranean). The total range of body masses of turtles used encompassed 2 to 60 kg. 3. It was demonstrated, using Doppler ultrasound, that sea turtles change blood flow in their appendages in response to external cooling and heating. Although this was efficient to accelerate whole body warming and delay the cooling of the body, turtles eventually equilibrated their body temperatures with that of the surrounding water. 4. The Q10 effect on metabolic rate of sea turtles subject to acute exposure to varying temperatures was 1.3. However, during long term exposure to seasonally decreasing water temperatures turtles showed a more pronounced reducted of metabolic rate (O10 = 5.4). Contemporaneously food intake and general activity were greatly reduced as well and dive durations increased. Body temperatures showed the same seasonal trend as the decreasing water temperatures. 5. Oxygen consumption rates of individual turtles, measured over 24-h-periods, peaked at different times of the day and no specific dynamic action after feeding could be detected.
7
Russ, Robert W. "SEC Regulation of Corporate 10K Filing Dates: The Effect on Earnings Management and Market Recognition." VCU Scholars Compass, 2006. http://scholarscompass.vcu.edu/etd/721.
Full textAbstract:
In November 2002, the Securities and Exchange Commission released a final ruling regarding a filing requirement change. The proposed requiredment change was for domestic companies to file annual and quarterly reports within 60 and 30 days, respectfully. This requirement was recommended for companies with a market value of at least $75 million and would reduce by 30 days the time allowed to file these reports. The Wall Street Journal article announcing this proposal stated the change was an effort to address some of the problems arising from accounting scandals such as the Enron scandal of 2001. A potential added benefit of the SEC rule change might be a reduction in earnings management. The purpose of this study is two fold. The first part is to test the theory that earnings management takes time. The second purpose is to examine the question of market recognition of earnings management. Sloan (1996) and other researchers report that the market does not recognize earnings management in the long term. Xie's (2001) results suggest that the market over prices earnings management. Balsam et al. (2002) found the market reacted negatively to abnormal accruals. The current research study uses a larger sample including firms not suspected of earnings management and fails to confirm the Balsam et al. result. The findings of the current study suggest that the results of the Balsam et al. study are either the result of the data selection process used in that study or the data selection processs used by Balsam et al. controlled for other market fluctuations not included in the current study. The results of this study suggest a positive relationship between earnings management and the time to file annual reports. Thsi finding supports the theory that moving earnings management from a future period to the current period requires time. Thus, the SEC rule change to reduce the time to file annual reports should reduce a company's ability to manipulate earnings.
8
Gong, Zhiyuan. "Regulation of tubulin gene expression in sea urchin embryos." Thesis, McGill University, 1987. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=74267.
Full textAbstract:
Regulation of tubulin gene expression in embryos of the sea urchin Lytechinus pictus has been experimentally investigated by use of cloned recombinant tubulin DNA and anti-tubulin antiserum. Tubulin synthesis appears to be autogenously regulated at the level of tubulin mRNA stability by the level of unpolymerized tubulin; i.e., the more unpolymerized tubulin, the less stable the tubulin mRNA. Destabilization of tubulin mRNA requires continued protein synthesis. Most of tubulin stored in eggs is unpolymerized; during embryogenesis the mass of tubulin per embryo changes little, but unpolymerized tubulin is increasingly polymerized into microtubules. There is a transcriptional stimulation of tubulin genes at the time of ciliogenesis but thereafter autoregulation by the ontogenetic decrease of the level of unpolymerized tubulin plays a predominant role for an increasing accumulation of tubulin mRNA. Deciliation results in a transient enhancement of transcription of tubulin genes, which is independent of the level of unpolymerized tubulin and does not require protein synthesis.
9
Akun, Deniz <1982>. "Banking Regulation in Turkey and Russia: An Economic Analysis." Doctoral thesis, Alma Mater Studiorum - Università di Bologna, 2013. http://amsdottorato.unibo.it/5328/.
Full textAbstract:
The importance of the banks and financial markets relies on the fact that they promote economic efficiency by allocating savings efficiently to profitable investment opportunities.An efficient banking system is a key determinant for the financial stability.The theory of market failure forms the basis for understanding financial regulation.Following the detrimental economic and financial consequences in theaftermath of the crisis, academics and policymakers started to focus their attention on the construction of an appropriate regulatory and supervisory framework of the banking sector.
This dissertation aims at understanding the impact of regulations and supervision on banks’ performance focusing on two emerging market economies, Turkey and Russia. It aims at examining the way in which regulations matter for financial stability and banking performance from a law & economics perspective. A review of the theory of banking regulation, particularly as applied to emerging economies, shows that the efficiency of certain solutions regarding banking regulation is open to debate. Therefore, in the context of emerging countries, whether a certain approach is efficient or not will be presented as an empirical question to which this dissertation will try to find an answer.
10
Papp, Laura V., and n/a. "Multiple Levels of Regulation of Human SECIS Binding Protein 2, SBP2." Griffith University. School of Biomolecular and Biomedical Science, 2006. http://www4.gu.edu.au:8080/adt-root/public/adt-QGU20070208.145623.
Full textAbstract:
Selenium is an essential trace mineral of fundamental importance to human health. Its beneficial functions are largely attributed to its presence within a group of proteins named selenoproteins in the form of the amino acid selenocysteine (Sec). Recently, it was revealed that the human selenoproteome consists of 25 selenoproteins, and for many of them their function remains unknown. The most prominent known roles of selenoproteins are to maintain the intracellular redox homeostasis, redox regulation of intracellular signalling and thyroid hormone metabolism. Sec incorporation into selenoproteins employs a unique mechanism that involves decoding of the UGA stop codon. The process requires interplay between distinct, intrinsic features such as the Sec Insertion Sequence (SECIS) element, the tRNASec and multiple protein factors. The work presented in this thesis has focused on characterising the regulation of human SECIS binding protein 2, SBP2, a factor central to this process. Experimental approaches combined with bioinformatics analysis revealed that SBP2 is subjected to alternative splicing. A total of nine alternatively spliced transcripts appear to be expressed in cells, potentially encoding five different protein isoforms. The alternative splicing events are restricted to the 5?-region, which is proposed to be dispensable for Sec incorporation. One of the variants identified, contains a mitochondrial targeting sequence that was capable of targetting SBP2 into the mitochondrial compartment. This isoform also appears to be expressed endogenously within the mitochondria in cells. Previous reports have depicted SBP2 as a ribosomal protein, despite the presence of a putative Nuclear Localisation Signal (NLS). In this study it was found that SBP2 subcellular localisation is not restricted to ribosomes. Intrinsic functional NLS and Nuclear Export Signals (NESs), enable SBP2 to shuttle between the nucleus and the cytoplasm via the CRM1 pathway. In addition, the subcellular localisation of SBP2 appears to play an important role in regulating Sec incorporation into selenoproteins. The subcellular localisation of SBP2 is altered by conditions imposing oxidative stress. Several oxidising agents induce the nuclear accumulation of SBP2, which occurs via oxidation of cysteine residues within a novel redox-sensitive cysteine rich domain (CRD). Cysteine residues were to form disulfide bonds and glutathione-mixed disulfides during oxidising conditions, which are efficiently reversed in vitro by the thioredoxin and glutaredoxin systems, respectively. These modifications negatively regulate selenoprotein synthesis. Cells depleted of SBP2 are more sensitive to oxidative stress than control cells, which correlated with a substantial decrease in selenoprotein synthesis after treatment with oxidising agents. These results provide direct evidence that SBP2 is required for Sec incorporation in vivo and suggest that nuclear sequestration of SBP2 under such conditions may represent a mechanism to regulate the expression of selenoproteins. Collectively, these results suggest that SBP2 is regulated at multiple levels: by alternative splicing, changes in subcellar localisation and redox control.
11
Limardi, Michela <1981>. "Trade policy, government and non-State regulation of international labor and environmental standards." Doctoral thesis, Alma Mater Studiorum - Università di Bologna, 2011. http://amsdottorato.unibo.it/4205/.
Full text
12
Sun, Zhongling. "Signal-Dependent Regulation of Skeletogenesis in the Sea Urchin Embryo." Research Showcase @ CMU, 2016. http://repository.cmu.edu/dissertations/687.
Full textAbstract:
Morphogenesis, the process by which the tissues and organs of the embryo are properly shaped, is a fundamental feature of development. In the sea urchin, the formation of the calcified enodoskeleton is a major morphogenetic event. Differentiation of the skeletogenic primary mesenchyme cells (PMCs) has been considered to occur in two phases: the autonomous specification of PMCs followed by signal-dependent patterning of PMCs and the embryonic skeleton they produce. Autonomous specification creates a homogenous population of PMCs, but the later differentiation of these cells is influenced by extrinsic signals that provide essential positional information. Recent studies showed that ectodermal growth factors are critically involved in the guidance of PMC migration and skeletal differentiation. However, a better understanding of the various signaling pathways that regulate skeletogenesis and their role in PMC gene expression remains to be established. This study examines the regulation of morphogenesis by signaling pathways, using skeletogenesis in the sea urchin embryo as a model. The aim of this study was to identify and study the roles of extrinsic signals in regulating PMC gene expression, focusing on the later, signal-dependent phase of PMC differentiation. By analyzing and classifying spatial expression patterns of 39 genes preferentially expressed in PMCs, I find that: 1) these genes are expressed non-uniformly within the PMC syncytium, reflecting a widespread influence of locally activated signals; 2) regions with elevated gene expression correlate with sites of rapid biomineral deposition at each stage; 3) non-uniform expression of genes within the PMC syncytium is controlled by multiple signal in a precise temporal sequence. I also provide evidence that ectoderm-derived VEGF signaling regulates gene expression in PMCs via the MAPK pathway on the ventral side of the embryo. Additionally, my work has identified an essential role for TGF-β signaling in skeletogenesis. Previous studies indicate that a complete repertoire of TGF-β signaling components is present in the sea urchin genome and TgfbrII mRNA is preferentially expressed in PMCs at the early gastrula stage. In this study, I show that TgfbrII mRNA is specifically expressed in the PMC lineage from the hatched blastula to the mid-gastrula stage. Perturbation experiments indicate that TgfbrII is activated by the single, sensu stricto TGF-β ligand in sea urchins and is required for skeletogenesis in the sea urchin embryo. I also show that the late activity of Alk4/5/7, the putative Type I receptor, regulates skeletogenesis in a dose-dependent manner. Isolation and in vitro culture of PMCs demonstrates that both Alk4/5/7 and TgfbrII function cell autonomously in these cells. I provide evidence that TGF-β-TgfbrII signaling is not involved in dorsal-ventral axis patterning or PMC specification; instead, this pathway plays a selective role in later skeletal patterning. Taken as a whole, my research demonstrates that skeletogenesis is regulated by a much more diverse suite of signaling pathways than was previously appreciated. These findings significantly expand our understanding of the complex regulation of skeletal morphogenesis by extrinsic signals during embryonic development.
13
Larman, Mark Graham. "Calcium and MAP kinase regulation during the cell cycle." Thesis, University of Newcastle Upon Tyne, 2001. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.340683.
Full text
14
Syukri, Ahmad. "Regulation and accumulation of metals in selected temperate and tropical anthozoans." Thesis, University of Newcastle Upon Tyne, 1995. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.294523.
Full text
15
Su, Yi-Hsien. "The regulation of sea urchin sperm by cyclic nucleotides and calcium /." Diss., Connect to a 24 p. preview or request complete full text in PDF formate. Access restricted to UC campuses, 2005. http://wwwlib.umi.com/cr/ucsd/fullcit?p3191992.
Full text
16
Broman, Evelina. "Regulation of bacterial production in the Råne estuary, northern Baltic Sea." Thesis, Umeå universitet, Institutionen för ekologi, miljö och geovetenskap, 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-108240.
Full textAbstract:
Earlier studies indicate that the interaction between heterotrophic bacteria and dissolved organic matter is rather different in rivers and estuaries. The aim of my thesis was to elucidate if bacteria are regulated differently in the Råne river and estuary during a spring situation. Surface water was collected at both locations and a bioassay performed to study limiting substances for bacterial production, proportion bio-available dissolved organic carbon (DOC) in the water and bacterial growth efficiencies (BGE). The Carbon, Nitrogen and Phosperous concentrations were all higher in the estuary than in the river. The bioassay showed that nitrogen-phosphorus limited the bacterial production at both locations, while DOC occurred in excess. The bio-available part of the DOC pool was larger in the estuary (~6%) than in the river (~3%). However, the BGE was much higher in the river (~40%) than in the estuary (~5%), indicating that a larger proportion of the consumed DOC was used for respiration in the estuary. I conclude that heterotrophic bacteria are limited by the same substance, but that the bacterial metabolism is quite differently regulated in the river and in the estuary.
17
Hanke, Philip Cosmo <1983>. "Regulating State Aid: Inter-jurisdictional competition, public choice, and corporate governance." Doctoral thesis, Alma Mater Studiorum - Università di Bologna, 2014. http://amsdottorato.unibo.it/6692/.
Full textAbstract:
Depending on the regulatory regime they are subject to, governments may or may not be allowed to hand out state aid to private firms. The economic justification for state aid can address several issues present in the competition for capital and the competition for transfers from the state.
First, there are principal-agent problems involved at several stages. Self-interested politicians might enter state aid deals that are the result of extensive rent-seeking activities of organized interest groups. Thus the institutional design of political systems will have an effect on the propensity of a jurisdiction to award state aid.
Secondly, fierce competition for firm locations can lead to over-spending. This effect is stronger if the politicians do not take into account the entirety of the costs created by their participation in the firm location race.
Thirdly, state aid deals can be incomplete and not in the interest of the citizens. This applies if there are no sanctions if firms do not meet their obligations from receiving aid, such as creating a certain number of jobs or not relocating again for a certain amount of time.
The separation of ownership and control in modern corporations leads to principal-agent problems on the side of the aid recipient as well. Managers might receive personal benefits from subsidies, the use of which is sometimes less monitored than private finance. This can eventually be to the detriment of the shareholders.
Overall, it can be concluded that state aid control should also serve the purpose of regulating the contracting between governments and firms. An extended mandate for supervision by the European Commission could include requirements to disincentive the misuse of state aid. The Commission should also focus on the corporate governance regime in place in the jurisdiction that awards the aid as well as in the recipient firm.
18
Lindberg, Marcus, Per Johansson, and Mikael Joélius. "LNG - Framtidens fartygsbränsle : Vad är det som hämmar utvecklingen av LNG-drift i Sverige?" Thesis, Linnéuniversitetet, Sjöfartshögskolan (SJÖ), 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:lnu:diva-39743.
Full textAbstract:
Sjöfarten står idag inför allt strängare miljökrav. För att uppnå miljövänligare resultat har allt fler rederier börjat se sig om efter ett miljövänligare bränsle. Östersjön är ett stort handelsområde där striktare krav från SECA träder i kraft den 1 januari 2015. Fartyg med LNG-drift diskuteras flitigt som ett alternativt bränsle inom den svenska sjöfartsnärningen, då utsläppen av NOx, svavel och partiklar är mindre än tjockoljan (HFO). Ett av problemen med LNG i Sverige är att det i dagsläget inte finns ett tillräckligt utvecklat infrastrukturnät för flytande naturgas. I denna rapport har vi med hjälp av kvalitativa intervjuer kartlagt svenska aktörer inom LNGs infrastrukturutveckling och vad det är som hämmar utvecklingen. Vår analys av intervjuerna visade att utvecklingen bromsades av att ingen vågat ta första steget. Hamnarna vill inte bygga terminaler om det inte finns en marknad för distribution och rederierna vill inte bygga fartyg om det inte finns tillgänglighet av LNG. Det har också framkommit att intresset från den svenska staten har varit mycket svagt, näst intill obefintligt. Det finns även en del tomrum i de svenska regelverken kring hanteringen av LNG, vilket är en av faktorerna till att LNGs utveckling hämmas.Shipping today faces stricter environmental requirements for pollution from vessels. Shipping companies have started to look for alternative fuel to achieve better environmental outcome. The Baltic Sea today is a major trading area for shipping . On 1 of January 2015 a new set of brand new and stricter regulation is getting implemented and these regulations are called SECA. Vessel running on LNG as an alternative fuel is today discussed extensively within the Swedish Maritime forum where emissions of NOx, sulfur and particles are less recipients than in heavy fuel oil (HFO). One of todays problems with a LNG distribution in Sweden are that the infrastructure is incomplete and outdated. This report has been built upon qualitative interviews with important actors within the Swedish maritime forum and also what impedes the development of the LNG’s infrastructure. The outcome of the interviews showed that the development has been slowed down because none within the Swedish martime forum have dared to take the first step. The ports does not want to develop terminals when there is no market demand and the shipping companies does not want to build vessel that runs on LNG when there is no market for distribution. Swedish governments involvement has been very weak, almost non-existing. There are also gaps in the Swedish regulations and restrictions of LNG cargo handling. This is aslo one of the factors that the development of LNG has been impeded.
19
Summerhill, Robin James. "The sea urchin egg ryanodine receptor and its regulation by cyclic ADP-ribose." Thesis, University of Oxford, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.300145.
Full text
20
Krsmanovic, Dusko <1985>. "A Law and Economics Analysis of Lobbying Regulation Towards an optimal structure through the Cost Indicator Index." Doctoral thesis, Alma Mater Studiorum - Università di Bologna, 2014. http://amsdottorato.unibo.it/6695/.
Full textAbstract:
This research primarily represents a contribution to the lobbying regulation research arena. It
introduces an index which for the first time attempts to measure the direct compliance costs of
lobbying regulation. The Cost Indicator Index (CII) offers a brand new platform for qualitative and
quantitative assessment of adopted lobbying laws and proposals of those laws, both in the
comparative and the sui generis dimension. The CII is not just the only new tool introduced in the
last decade, but it is the only tool available for comparative assessments of the costs of lobbying
regulations.
Beside the qualitative contribution, the research introduces an additional theoretical framework for
complementary qualitative analysis of the lobbying laws. The Ninefold theory allows a more
structured assessment and classification of lobbying regulations, both by indication of benefits and
costs. Lastly, this research introduces the Cost-Benefit Labels (CBL). These labels might improve an
ex-ante lobbying regulation impact assessment procedure, primarily in the sui generis perspective.
In its final part, the research focuses on four South East European countries (Slovenia, Serbia,
Montenegro and Macedonia), and for the first time brings them into the discussion and calculates
their CPI and CII scores. The special focus of the application was on Serbia, whose proposal on the
Law on Lobbying has been extensively analysed in qualitative and quantitative terms, taking into
consideration specific political and economic circumstances of the country.
Although the obtained results are of an indicative nature, the CII will probably find its place within
the academic and policymaking arena, and will hopefully contribute to a better understanding of
lobbying regulations worldwide.
21
Novak, Zsofia A. "The role and regulation of Asterless in the centrosome cycle." Thesis, University of Oxford, 2014. http://ora.ox.ac.uk/objects/uuid:4fadaef1-8c9e-4c70-ac59-47f35af3988e.
Full textAbstract:
Centrosomes are the main microtubule organizing centres in animal cells and are formed by a pair of centrioles together with surrounding pericentriolar material (PCM). Cycling cells duplicate their centrosomes strictly once per cell cycle. This process is driven by the semi-conservative duplication of the centrioles that are found at the centrosome core. During the exit from mitosis the two centrioles within the single inherited centrosome separate, and upon the start of S-phase each of these inherited mother centrioles assembles an adjacent daughter at its side. This process results in two complete centrosomes that can form the poles of the mitotic spindle, and thus segregate evenly to the next cell generation. The formation of a daughter centriole suppresses the initiation of new duplication events from the same templating mother centriole until this daughter separates - disengages - at the end of the cell cycle. This regulation - that acts to repress centriole amplification - is summarized in the 'licensing model of centriole duplication' (Tsou and Stearns, 2006). This model states that centriole disengagement provides the license for the re-duplication of mother centrioles. Importantly, experiments show that while abolishing centriole engagement is sufficient to allow mother centrioles to re-duplicate within the same cycle, it is insufficient to allow daughter centrioles the assembly of a granddaughter before they mature into mothers towards the end of their first cell cycle. The molecular nature of this daughter-to-mother transition remains mysterious. In this thesis I show that in Drosophila embryos the essential centriole duplication protein Asl is not incorporated into daughter centrioles as they assemble during S-phase, but is only incorporated once mother and daughter separate at the end of mitosis. The initial incorporation of Asterless (Asl) is irreversible, and is dependent on centriolar DSas-4. Crucially, Asl incorporation is essential for daughter centrioles to mature into mothers that can support centriole duplication. I propose that Asl acts as a permanent primary license that allows new centrioles to duplicate for the first time. Once acquired, this primary license is not lost but rather further regulation is taken over by the reduplication licensing mechanism, disengagement. This work extends the previously proposed licensing model to also explain how new centrioles are licensed for their first duplication event.
22
Orcutt, K. M. "Environmental factors regulating N2 fixation by Trichodesmium spp. in the Sargasso Sea." Thesis, Swansea University, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.638373.
Full textAbstract:
A seasonal study measuring N2 fixation, primary production and biomass of Trichodesmium spp. was conducted on a monthly basis for over two years at the Bermuda Atlantic Time-series Study (BATS) site. Due to seasonal changes in hydrography and meteorology, the BATS site offers a unique opportunity to study the environmental factors regulating N2 fixation by Trichodesmium. Nitrogen fixation was measured using the 15N2 technique and the acetylene reduction assay simultaneously. The geometric mean of the molar ratio between the two techniques was 3:1 but varied by a factor of 40. Measurements of 15N2 incorporation was conducted on single colonies and appeared to be the more sensitive method. Rates of N2 fixation per colony ranged from 0.01-17 ng Ncol-1 H-1. Nitrogen fixation rates were compared to primary production, incorporation of organic and inorganic nitrogen and the iron content of the colonies. The seasonal pattern of N2 fixation was highly correlated to aeolian dust deposition data collected from the AEROCE tower in Bermuda. Single trichomes of Trichodesmium spp. were enumerated and found to develop at the nutricline. Peak abundance of trichomes preceded maximal abundance of colonies in the surface waters at the BATS site in later summer and fall. An annual integrated N2 fixation rate, from the upper 140 m of the water column, was 0.024 mol N m-2 y-1 using an average in situ depth profile of colony distribution, enumerated trichomes and corrected for the effect of reduced light on the rate of N2 fixation. High rates of ectoenzyme activity associated with Trichodesmium colonies showed that the cyanobacteria are also important in regenerated production. The primary environmental factors regulating N2 fixation by Trichodesmium appeared in the following sequence throughout the year: nitrate intrusion during vertical mixing of the water column, increased surface seawater temperature, low wind speed causing stratification and atmospheric deposition of iron. The annual contribution of N2 fixation by Trichodesmium spp. to new production was of the same order or magnitude as recent refined model estimates for the North Atlantic Ocean.
23
Dyer, Alexei. "Acid-base regulation in the sea urchin Parechinus angulosus during CO₂-induced seawater acidification." Bachelor's thesis, University of Cape Town, 2013. http://hdl.handle.net/11427/7631.
Full textAbstract:
Ocean acidification is predicted to have adverse effects on the physiologies of marine organisms, particularly those that produce calcified structures. Extracellular homeostasis is considered to be critical to mediating the effects of ocean acidification. Due to their low metabolic rates and weak ability to regulate ion exchange, sea urchins are thought to be particularly weak acid-base regulators. Recent findings showing species-specific capacities for extracellular pH regulation however suggest that species currently exposed to natural CO₂ elevations, such as upwelling events, may have a higher capacity tolerate elevated CO₂. The sea urchin Parechinus angulosus currently experiences natural CO₂ variations within the Benguela upwelling system and is therefore predicted to possess the capacity to compensate moderate acid-base disturbances. Urchins were submitted to control (8.0), intermediate (7.7) and low (7.4) seawater pH treatments for 14 days to investigate the capacity to regulate extracellular acid-base status. Extracellular pH changes induced by exposure to intermediate (pH 7.7) seawater acidification were fully compensated through the accumulation of approximately 2.0 mmol l-1 of bicarbonate. The bicarbonate accumulation was only sufficient to partially compensate extracellular acid-base status during exposure to low (7.4) seawater pH. Results from acute (24 hour) exposure to low (7.4) seawater pH reveal that bicarbonate accumulation, despite being evident within 24 hours, is not sufficient to compensate extracellular pH. This study provides further support that sea urchins exposed to natural CO₂ variability possess a limited capacity to regulate extracellular acid-base disturbances. P.angulosus may therefore already be adapted to deal with a moderate reduction in seawater pH to 7.7, but lacks the iono-regulatory capacity to accumulate sufficient bicarbonate to deal with a reduction of seawater pH to 7.3. Long-term studies are needed to assess the role of acid-base regulation as a mediator of broader physiological tolerance to ocean acidification, and its consequences at the level of the whole organism.
24
Desogus, Claudia <1980>. "Competition and Innovation in the EU Regulation of Pharmaceuticals: The Case of Parallel Trade." Doctoral thesis, Alma Mater Studiorum - Università di Bologna, 2010. http://amsdottorato.unibo.it/3116/.
Full text
25
Loftus, Sarah Jane. "Regulation of E2F-1 by methylation and NEDDylation." Thesis, University of Oxford, 2012. http://ora.ox.ac.uk/objects/uuid:e0befc5a-76a3-4a35-b768-80a9dda6f307.
Full textAbstract:
E2F-1 has a central role in cell cycle orchestration, and its activity is tightly regulated. One of the ways E2F-1 activity is controlled is by direct modification by post translational modifications such as acetylation, ubiquitination and phosphorylation. Here it was demonstrated that E2F-1 is targeted by two novel modifications, namely methylation by Set7/9 and NEDDylation, both within the DNA binding and heterodimerisation domain of the protein. NEDDylation and methylation of E2F-1 both decrease the stability and diminish the transcriptional activity of E2F-1. Lysine residues in E2F-1 involved in NEDDylation are also targeted by methylation, allowing the potential for interplay between these modifications. Methylation of E2F-1 was demonstrated to be a prerequisite for its NEDDylation and the multi-domain protein UHRF1 implicated in mediating this effect. The results define a new level of control on E2F-1 and suggest a protein code with pleiotropic effects involved in E2F-1 regulation.
26
Lehmkuhl-Dakhwe, K. Virginia. "Regulation of p53, p21, ARF, BIM, and BAX by the Transcription Factor Trip-Br1." Ohio University / OhioLINK, 2007. http://rave.ohiolink.edu/etdc/view?acc_num=ohiou1194549826.
Full text
27
Herriott, Ashleigh Jane. "Regulation of spindle assembly checkpoint (SAC) by phosphorylation and protein-protein interactions in Drosophila melanogaster." Thesis, University of Newcastle Upon Tyne, 2012. http://hdl.handle.net/10443/1736.
Full textAbstract:
Chromosome segregation is a complex, but subsequently error- prone process, who’s accuracy is essential to prevent uneven DNA distribution between mother and daughter cells. Such unequal chromosome segregation can often result in aneuploidy, which is a prevalent phenotype of cancer cells, and so surveillance mechanisms must exist within the cell cycle to detect and correct the cause of such chromosome division errors, before allowing the cell to divide. The Spindle Assembly Checkpoint (SAC) has evolved to monitor the interaction between microtubules, and the point at which they attach sister chromosomes, the kinetochore. By detecting attachment and resulting tension abnormalities, the SAC halts the metaphase to anaphase transition if chromosomes are not aligned correctly at the metaphase plate. By disallowing cell division to occur in the absence of proper chromosome alignment, the SAC minimises the frequency of uneven DNA distribution and the consequent problems this can incur. Silencing of the SAC, and normal cell progression is not promoted until correction mechanisms have achieved proper bioriented chromosome attachments. The target of the SAC is widely accepted to be Cell Division Cycle 20 (Cdc20), which is the activator of the Anaphase Promoting Complex or Cyclosome (APC/C), the E3 ubiquitin ligase that drives cells into anaphase. By inhibiting Cdc20, the activity of the APC/C is halted, and cells are arrested at metaphase. A number of key proteins are believed to be involved in the sequestration of Cdc20, by incorporating it into an inhibitory Mitotic Checkpoint Complex (MCC). This MCC complex is believed to comprise of Cdc20, BubR1, Bub1 and Mad2, although there is speculation as to whether Mad2 is part of the complex, or merely promotes its formation. The proteins involved in the MCC all localise to kinetochores with activation of the SAC, although it remains unclear as to whether the MCC forms at the kinetochore upon localisation of the various components, or can form in part or as a whole, moving to kinetochores upon SAC activation. Sub-complexes of the MCC have been detected outside of mitosis, which provide evidence in favour of a kinetochore-independent MCC formation. However, if this were the case, it could be assumed that modification (such as phosphorylation) to either MCC components or the APC/C itself would need to occur in mitosis or with SAC activation, allowing for APC/C inhibition only with SAC activation, and to prevent IV non-specific inhibition of APC/C by the MCC elsewhere in the cell cycle. These issues still remain unclear. In order to investigate further, the requirement of direct kinetochore localisation of MCC components in the formation of the complex, this thesis aims to provide evidence of the effect of disrupting such kinetochore localisation upon checkpoint function, as well as the impact of removal of Cdc20 modifications on MCC formation. In addition to this, the protein-protein interaction domains between Cdc20 and BubR1, proven essential for SAC function, are investigated within Drosophila melanogaster. Collectively, the data in this thesis provides an insight into the regulation of SAC in Drosophila. The Cdk1/Cyclin B phosphorylation of Fizzy (the Drosophila homologue of Cdc20) is confirmed to have an effect on MCC formation, and can be mapped to three specific sites on the N-terminal of Fizzy, which are conserved across various species. In addition to the effect of Cdk1/Cyclin B phosphorylation on the interaction between Fizzy and other SAC proteins, the importance of the BubR1 KEN box motif on the Fizzy-BubR1-Mad2 interaction is confirmed, implicating another essential domain for MCC formation in Drosophila. With regard to kinetochore localisation of SAC components, a model is achieved in which a dramatic reduction of Mps1, previously shown to disturb kinetochore localisation of Mad1, Mad2 and BubR1 in Xenopus, confirms a role for Mad2 kinetochore localisation in SAC activation, even though Fizzy localisation is unperturbed. Overall, these findings may provide a useful insight into the complex relationships, kinetochore localisation requirements and inter-protein dependencies within the regulation of MCC formation and SAC signalling in Drosophila melanogaster.
28
Lobo, Ana Karla Moreira. "Photosynthesis regulation by sucrose metabolism under water deficit and source-sink alterations in sugarcane." reponame:Repositório Institucional da UFC, 2016. http://www.repositorio.ufc.br/handle/riufc/21479.
Full textAbstract:
LOBO, A. K. M. Photosynthesis regulation by sucrose metabolism under water deficit and source-sink alterations in sugarcane. 2016. 118 f. Tese (Doutorado em Bioquímica)-Universidade Federal do Ceará, Fortaleza, 2016.Submitted by Anderson Silva Pereira (anderson.pereiraaa@gmail.com) on 2017-01-03T20:20:30Z No. of bitstreams: 1 2016_tese_akmlobo.pdf: 4541762 bytes, checksum: e3450d87e286b1a5213eb866921b6c94 (MD5)
Approved for entry into archive by Jairo Viana (jairo@ufc.br) on 2017-01-09T21:32:52Z (GMT) No. of bitstreams: 1 2016_tese_akmlobo.pdf: 4541762 bytes, checksum: e3450d87e286b1a5213eb866921b6c94 (MD5)
Made available in DSpace on 2017-01-09T21:32:52Z (GMT). No. of bitstreams: 1 2016_tese_akmlobo.pdf: 4541762 bytes, checksum: e3450d87e286b1a5213eb866921b6c94 (MD5) Previous issue date: 2016
Water deficit stress is the major limiting factor for plant growth and development, constraining food production. In order to survive in such dry conditions, many biochemical and physiological changes must be triggered by plants. In general, the responses to drought are loss of water content, reductions of stomatal conductance and photosynthesis and increase of carbohydrates. Soluble sugars play a key role in plant metabolism, acting as substrates and modulators of enzyme activity in carbon-related pathways and controlling the expression of different genes related to carbon, lipid and nitrogen routs. However, the mechanisms involved with photosynthesis down-regulation by drought and sugars in C4 plants are not fully understood. The aim of this study was to investigate how drought and source-sink perturbation regulate photosynthesis in sugarcane plants. Therefore, two studies were conducted with sugarcane plants with four months old cultivated under greenhouse conditions. In the first study sugarcane plants (cv. IACSP94-2094) were subjected to water deficit for 5 days (WD) with concomitant spraying of 50 mM exogenous sucrose (WD + Suc). While in the second study source-sink relationship was perturbed in two sugarcane cultivars (cv. IACSP94-2094 and cv. IACSP95-5000) by imposing partial darkness, spraying 50 mM exogenous sucrose and their combination for 5 days. The negative effects of WD in the gas exchange and photochemical parameters were aggravated by exogenous sucrose. Photosynthesis reductions were related to both stomatal and biochemical limitations, but exogenous sucrose intensified metabolic restrictions mainly through down-regulation of Rubisco initial activity and PSII effective quantum efficiency in drought-stressed plants. In addition, Rubisco activation state was decreased by WD + Suc, indicating perhaps that the activity of this enzyme was reduced by tight-binding inhibitors, such as sugars phosphates. Sucrose metabolism enzymes and sugars amount were also differently altered by WD and WD + Suc in leaves, sheath and stalk in WD and WD +Suc plants. Interestingly, Sucrose/hexose ratio decreased in both leaf and sheath whereas it was increased in stalk, suggesting that sucrose and related sugars were intensely metabolized and transported in drought-stressed plants. In well-watered conditions, photosynthesis was inhibited by sucrose spraying in both genotypes, through decreases in maximum Rubisco carboxylation rate (Vcmax), initial slope of A-Ci curve (k), stomatal conductance (gs) and ATP production driven by electron transport (Jatp). The partial darkness and sucrose spraying combination did not change photosynthesis in both genotypes. Significant increases in Vcmax, gs and Jatp and marginal increases in k were noticed when combining partial darkness and sucrose spraying compared with sucrose spraying alone. Altogether, these results suggest that CO2 assimilation impairment is aggravated by exogenous sucrose in drought-stressed plants. This limitation was mainly related to biochemical restrictions, specially associated with Rubisco initial activity and PSII quantum efficiency. In contrast, in vitro PEPCase activity and amount were increased in sucrose-treated plants, suggesting that C4 cycle efficiency was reduced in vivo by C3 cycle inhibition under drought conditions. Moreover, sucrose amount was increased in the stalk, suggesting the feedback regulation from stalk to source leaves in drought-stressed plants. Our data also revealed that increases in sink strength due to partial darkness offset the inhibition of sugarcane photosynthesis caused by sucrose spraying, enhancing the knowledge on endogenous regulation of sugarcane photosynthesis through the source-sink relationship.
A deficiência hídrica é o principal fator limitante para o crescimento e desenvolvimento das culturas. Para sobreviver nessas condições adversas, várias modificações bioquímicas e fisiológicas são desencadeadas pelas plantas. Em geral, os efeitos da seca em plantas são diminuição do status hídrico, reduções da condutância estomática, fotossíntese e crescimentos e aumentos nos níveis de carboidratos. Os açúcares solúveis desempenham papéis chave no metabolismo das plantas, atuando como substratos e moduladores da atividade enzimática em vias relacionadas com o carbono. Além disso, os açúcares controlam a expressão de genes associados com as rotas do metabolismo do carbono, lipídios e nitrogênio. Entretanto, os mecanismos envolvidos com a regulação negativa da fotossíntese por deficiência hídrica e açúcares em plantas C4 não estão totalmente entendidos. O objetivo deste estudo foi investigar como a deficiência hídrica e perturbações na relação fonte-dreno regulam a fotossíntese em plantas de cana-de-açúcar. Dois estudos foram conduzidos com plantas de cana-de-açúcar com quatro meses de idade cultivadas sob condições de casa de vegetação. No primeiro estudo, plantas de cana-de-açúcar (cv. IACSP94-2094) foram submetidas a deficiência hídrica por 5 dias (WD) com subsequente aplicação de sacarose exógena 50 mM (WD + Suc). Enquanto que no segundo estudo a relação fonte-dreno foi perturbada em duas cultivares de cana-de-açúcar (cv. IACSP94-2094 and cv. IACSP95-5000) pela imposição parcial de sombreamento, aplicação de sacarose exógena 50 mM e por suas combinações por 5 dias. Os efeitos negativos de WD nos parâmetros de trocas gasosas e fotoquímicos foram agravados por sacarose exógena. As reduções na fotossíntese foram relacionadas com limitações estomáticas e bioquímicas, porém a sacarose exógena intensificou as restrições bioquímicas principalmente por reduções na atividade inicial de Rubisco e eficiência quântica do PSII em plantas sob seca. Além disso, o estado de ativação de Rubisco foi inibido por WD + Suc, sugerindo que a atividade inicial dessa enzima foi possivelmente reduzida por inibidores que se ligam fortemente em seu sitio ativo, tais como açúcares fosfato. As enzimas do metabolismo de sacarose e a concentração de açúcares foram modificados diferentemente por WD e WD + Suc em folhas, bainha e colmo. Interessantemente, a relação sacarose/hexose decresceu em folhas e bainha, enquanto que no colmo essa relação aumentou, sugerindo que sacarose e outros açúcares relacionados foram intensamente metabolizados e transportados. Em condições irrigadas a fotossíntese foi inibida pela aplicação de sacarose nos dois genótipos, através de decréscimos da taxa máxima de carboxilação de Rubisco (Vcmax), inclinação inicial da curva A-Ci (k), condutância estomática (gs) e produção de ATP direcionada pelo transporte de elétrons (Jatp). A combinação de sombreamento parcial e sacarose não alterou a fotossíntese em ambos os genótipos. Significantes aumentos em Vcmax, gs, Jatp e k foram observados quando sombreamento parcial e sacarose foram combinados em comparação com plantas tratadas apenas com sacarose. Em conclusão, esses resultados sugerem que o impedimento da assimilação de CO2 é agravada por adição de sacarose exógena em plantas sob estresse hídrico. Essa limitação foi relacionada principalmente com restrições bioquímicas, especialmente associadas com reduções na atividade inicial de Rubisco e eficiência quântica do FSII. Em contraste, a atividade in vivo e concentração de PEPCase foram aumentadas em plantas tratadas com sacarose e estresse hídrico, sugerindo que a eficiência do ciclo C4 foi reduzida in vivo por inibições do ciclo C3 sob condições de seca. Além disso, o conteúdo de sacarose aumentou no colmo, indicando uma regulação de feedback do colmo para as folhas em plantas sob seca. Nossos dados revelam ainda que aumentos na força do dreno devido ao sombreamento parcial aliviaram os efeitos inibitórios na fotossíntese de cana-de-açúcar causados pela aplicação de sacarose, aumentando o conhecimento na regulação endógena da fotossíntese de cana-de-açúcar através da relação fonte-dreno.
29
Medina, Henríquez Paula Javiera. "Retinoic acid signaling pathway : gene regulation during the onset of puberty in the European sea bass." Doctoral thesis, Universitat Politècnica de Catalunya, 2019. http://hdl.handle.net/10803/667249.
Full textAbstract:
European sea bass (Dicentrarchus labrax) aquaculture is a thriving industry in Spain where it reached about 23,500 t and a market value of approximately 133 million euros. However, most of the sea bass farms produce a high percentage of males (70-90%) since the rearing temperature is increased during the initial stages of development to speed up development and growth. This is a problem because in this species, generally, females exhibit higher growth rates than males. This situation is aggravated as nearly 30% of these males reach puberty precociously during the first year of life, before attaining commercial size. Puberty is accompanied by a decrease in growth rates as energy diverts towards gonadal growth instead of somatic growth. In addition, it comes along with muscle waste and losses in the organoleptic properties of the meat. Because of these biological responses to captive breeding, there is a great need to understand the reproductive process and its control under intensive production conditions. The main objective of this thesis is to increase the knowledge of European sea bass reproduction. It is focussed on the role of the retinoic acid (RA) signalling pathway during early development and puberty.
Using a costume-made sea bass oligomicroarray we found several groups of genes that were differentially expressed in testis during the onset of male puberty. One of these groups included genes that belong to the RA signalling pathway. RA is the active form of vitamin A and is known to be essential for the onset of meiosis in tetrapods, although its role in fish is yet to be confirmed. These results prompted us to deepen on the possible role of the RA signalling pathway in gonad development and gametogenesis. An in silico analysis allowed us to describe for the first time the structure, phylogeny and evolutionary history of several genes and proteins involved in the synthesis and degradation of RA in the European sea bass. After an exhaustive histological study of gonad development, we could accurately identify specific stages of ovarian and testicular differentiation in this species. The expression of the main genes of the RA signalling pathway in specific stages of gonad development confirmed its role in the onset of puberty. Finally, an in vitro culture system of testicular explants from juvenile prepubertal fish and of testicular preparations from adult fish were set up to study the role of this pathway in the onset of puberty in sea bass males. The functional responses of genes related to RA transport, synthesis, degradation and receptor signaling were evaluated in the presence of stimulators and an inhibitors of the pathway and in different meiosis scenarios.
The results show that in the sea bass: a) the onset of meiosis coincides with an increase of 11KT levels and involves several pathways, including RA signalling; b) the enzymes related to RA synthesis and degradation have all the structural features to fulfil their specific functions; c) there is a well conserved evolutionary history of the enzymes involved in RA synthesis and degradation; d) the absence of stra8, a meiosis gatekeeper present in vertebrates and also in some fish, suggests that RA signaling in this species does not occur through the transduction of this particular gene; e) the genes involved in the RA signaling pathway are evolutionarily well conserved and play an important role in gonad development and gametogenesis; f) the expression dynamics of cyp26a1 during gonad development makes it an excellent molecular marker for the onset of meiosis.
This thesis increases the understanding of the early molecular and endocrine events leading to puberty in the European sea bass by characterizing the RA signaling pathway. Moreover, it provides new questions and opens a novel research line to study the role of RA in puberty.La acuicultura de la lubina Europea (Dicentrarchus labrax) es una industria pujante en España que alcanza unas 23.500 t y un valor de mercado cercano a 133 millones de euros. Sin embargo, la mayoría de las piscifactorías produce un elevado porcentaje de machos (70-90%) ya que, para acelerar el desarrollo y el crecimiento, se aumentan las temperaturas de cultivo durante las primeras etapas de vida. Esto supone un problema en la lubina ya que generalmente las hembras presentan mayores tasas de crecimiento que los machos y que el 30% de estos alcanza la pubertad precozmente durante el primer año de vida, antes de llegar a la talla comercial. Además, la pubertad está acompañada por una disminución de las tasas de crecimiento somático que implica un desgaste muscular y pérdidas en la calidad organoléptica de la carne. Debido a estas respuestas biológicas, existe una gran necesidad de comprender el proceso reproductivo y su control en condiciones intensivas de producción. El objetivo general de esta tesis es contribuir al conocimiento de la reproducción de la lubina europea, y se centra en el estudio de la ruta de señalización del ácido retinoico (RA) durante estados tempranos del desarrollo y la maduración sexual. La utilización de un oligomicroarray de lubina, indicó la existencia de varios genes con expresión diferencial al inicio de la pubertad en machos. Entre ellos seleccionamos un grupo que incluía genes de la vía de señalización del RA, la forma activa de la vitamina A, fundamental para el inicio de la meiosis en tetrápodos. Un análisis in silico nos permitió describir por primera vez, la estructura, filogenia y la historia evolutiva de genes y proteínas implicados en la síntesis y degradación del RA. Tras un exhaustivo estudio histológico del desarrollo gonadal pudimos identificar con exactitud estados específicos de la diferenciación ovárica y testicular. El estudio de la expresión de los principales genes de la ruta de señalización del RA en estados específicos del desarrollo gonadal sirvió para demostrar su papel en el inicio de la pubertad. Finalmente, se puso a punto un sistema de cultivo in vitro de explantes testiculares de individuos prepúberes tanto juveniles como adultos para el estudio funcional y la determinación del papel de la ruta de señalización del RA en el inicio de la pubertad en machos. Con este fin se evaluó la respuesta funcional de los genes relacionados con el transporte, síntesis, degradación y señalización del RA ante la presencia de estimuladores e inhibidores de la vía y en diferentes escenarios de meiosis. Los resultados de la tesis demuestran que en la lubina: a) el inicio de la meiosis coincide con un aumento en los niveles de 11KT y que involucra varias rutas, entre ellas la de señalización del RA; b) las enzimas relacionadas con la síntesis y degradación del RA poseen todas las características estructurales para poder cumplir su función; c) existe una historia evolutiva bien conservada de las enzimas implicadas en la síntesis y degradación del RA, d) al igual que en otros teleósteos, la ausencia de stra8, marcador específico de meiosis en tetrápodos, sugiere que la señalización del RA en esta especie no ocurre a través de la transducción de este gen en particular; e) los genes implicados en la vía de señalización del RA están conservados, igual que en otros vertebrados, y juegan un papel relevante en el desarrollo gonadal y la gametogénesis, f) la dinámica de expresión del gen cyp26a1 durante el desarrollo gonadal le convierte en un excelente marcador molecular del inicio de la meiosis. Esta tesis contribuye al conocimiento del inicio de la pubertad en la lubina al caracterizar por primera vez la ruta de señalización del RA en esta especie y al proponer herramientas moleculares para su estudio. Además, aporta nuevas preguntas y abre una importante línea de investigación para el estudio del RA en la pubertad
30
Rößl, Dietmar, and Elisabeth Reiner. "The Implementation of the Regulation 1435/2003 on the Statute European Cooperative Society (SCE) in Europe." WU Vienna University of Economics and Business, 2010. http://epub.wu.ac.at/2937/1/SCE_Report_Austria%2Dfinal.pdf.
Full text
31
Klambauer, Eva. "Sex work regulation and legal consciousness : a comparative socio-legal study of England (UK) and New South Wales (Australia)." Thesis, King's College London (University of London), 2018. https://kclpure.kcl.ac.uk/portal/en/theses/sex-work-regulation-and-legal-consciousness(19913efc-81d7-4515-88d2-e4cb34875ef1).html.
Full textAbstract:
The regulation of sex work is a contested, emotive, and polarising policy issue. Sex workers are commonly excluded from the political debate regarding the regulation of sex work. While sex workers’ rights organisations are gaining ground internationally, the voices of sex workers who are not politically active are rarely heard. Yet, the experiences of sex workers provide the most accurate narrative of how the regulation of the sex industry affects those whom sex work policy commonly claims to protect. Drawing on 138 interviews with sex workers and key stakeholders, this study investigates the relationship between sex work, its regulation, and sex workers’ legal consciousness. Based on a socio-legal, interpretivist, and comparative case study of England, which can be classified as a neo-abolitionist legal framework of sex work, and New South Wales (NSW) in Australia, where the sex industry is largely decriminalised, this thesis demonstrates that the legal framework of sex work matters for sex workers’ working conditions, safety, and access to rights far beyond the direct impact of the written law. Despite discrepancies between statute and implementation, the differing degrees of legality of sex work in England and NSW profoundly impact on sex workers’ sense of legal entitlement. Additionally, this study found that sex workers’ grievances differ between sectors of the industry according to their legal and social status. Different groups of sex workers not only put forward diverging, but in many cases also contradicting legal claims. Although decriminalisation is the far more appropriate legal framework for ensuring sex workers’ safety, well-being and autonomy, additional protective measures are crucial for balancing out differences in the bargaining power of street-based, brothel-based and independent indoor workers.
32
Rogers, David. "CIS-REGULATORY ANALYSIS OF THE PIGMENT CELL DIFFERENTIATION GENE POLYKETIDE SYNTHASE." Master's thesis, University of Central Florida, 2008. http://digital.library.ucf.edu/cdm/ref/collection/ETD/id/2701.
Full textAbstract:
The analysis of Gene Regulatory Networks (GRNs) is essential to understanding the complete process of embryo development. Elucidating every gene regulatory circuit from maternal regulatory inputs all the way to the activation of differentiation gene batteries is an important step in increasing our understanding of developmental biology. In this work I study the cis-regulatory architecture of a pigment cell differentiation gene, polyketide synthase (SpPks) in the sea urchin Strongylocentrotus purpuratus. SpPks encodes an enzyme that is responsible for the biosynthesis of the sea urchin pigment echinochrome in larval pigment cells. The analysis of the promoter of a differentiation gene will lead to identifying the direct upstream regulators and ultimately to elucidating the structure of the upstream gene regulatory network, which is mostly uncharacterized. From previous studies the transcription factors SpGcm and SpGatae are predicted to be positive regulators of SpPks. Here, I identify a minimal 1kb promoter region containing putative DNA-binding sites for both GCM and GATAE that is able to recapitulate the expression of SpPks. I further show by mutagenesis that a putative DNA-binding site for GCM located 1,179 base pairs upstream of the start of transcription is a direct target for the positive cis-regulation of SpPks. Quantitative analysis of the transcriptional regulatory function of the GCM-mutagenized construct suggests that GCM is not necessary for the start of SpPks transcription but is required for its maintenance. Several GATA E binding sites have been identified within the minimal promoter for SpPks by means of consensus sequence. My analysis suggests that GATA E may be a direct positive regulator and could potentially be required for the onset of transcription of SpPks, though further experimentation will be necessary to characterize the exact regulatory function of GATA E.M.S.
Department of Biology
Sciences
Biology MS
33
Unsworth, Amanda J. "The role of protein kinase C in platelet activation." Thesis, University of Oxford, 2012. http://ora.ox.ac.uk/objects/uuid:114582b8-185a-41f5-958c-77038fb185df.
Full textAbstract:
The Protein kinase C (PKC) superfamily is a key regulator in platelet activation with individual isoforms playing distinct roles. This thesis focuses on the role of the novel PKC isoforms downstream of several agonists using both pharmacological and genetic approaches and human and mouse platelets. Quantification of the protein levels of PKC isoforms identified different levels of the five major PKC isoforms expressed in human platelets and also differences between levels of the same isoform in human and mouse platelets. Use of a selection of broad spectrum and isoform-specific inhibitors, identified both positive and negative novel roles for PKC in the regulation of human and mouse platelets. A net positive role for PKC was found in GPVI, Clec-2, and PAR receptor signalling, with classical isoforms of PKC playing a major role in aggregation and dense granule secretion. A novel negative regulatory role was also identified in the regulation of ADP-induced platelet activation for PKC~, and both PKCE and PKC~ in human and mouse platelets respectively. Gene knock-out mouse models confirmed a positive regulatory role for PKCe in allb~3 outside-in signalling but identified no other regulatory role for PKCe in agonist induced platelet activation. Despite this relatively minor role, functional redundancy was identified between PKCe and PKCE isoforms in haemostasis, as tail bleeding was significantly increased in mice deficient in both novel isoforms. The work presented here identifies key roles for the PKC superfamily in the complex regulation of platelet activation, with different isoforms supporting and limiting the process of thrombus formation and haemostasis.
34
Riedemann, Johann. "Functional analysis and recombinant expression of a sea urchin G-string binding factor." Thesis, Stellenbosch : Stellenbosch University, 2001. http://hdl.handle.net/10019.1/52277.
Full textAbstract:
Part of work presented in this thesis has been published: Regulation of gene expressions by GC-rich DNA cis-elements / J.P. Hapgood, J. Riedemann and S.D. Scherer in Cell biology international, vol. 25, 2001.Thesis (MSc)--Stellenbosch University, 2001.
ENGLISH ABSTRACT: The sea urchin G-string binding factor 1 (suGF1) has previously been shown to bind with high affinity and selectivity to stretches of contiguous deoxyguanosine residues, a DNA motif found in the upstream regions of many unrelated genes from several organisms. It has been proposed that suGF1 plays a role in transcriptional regulation. Homopurine.homopyrimidine stretches have been shown to form unusual DNA structures, in vitro. To investigate the potential of the suGF1 binding site to form unusual structures under certain conditions, synthetic oligodeoxyribonucleotides containing the suGF1 poly(dG).(dC) binding site were subjected to circular dichroism (CD) analyses. The CD results indicate that the suGF1 binding site forms a mixture of unusual DNA structures, as deduced by comparison with the spectra obtained for B-DNA, triplex and quadruplex conformations. These results are consistent with the hypothesis that suGF1 specifically recognises G-strings that exhibit unusual structures. Exhaustive database searches showed that suGF1 has no significant homology with any previously identified proteins or cDNAs from any species. Given the relevance of mammalian models to medical science, and since no sea urchin cell lines are currently available, the identification of a mammalian functional homologue would facilitate determination of the in vivo function of such a potentially important, putative, novel DNAbinding protein in mammalian cell lines. In this study sequence analysis tools were used to identify hORFX, a putative human functional homologue of suGF1. Similarities in the domain organisation of the two proteins, prompted an investigation into the DNA-binding properties of hORFX, as well as a more detailed structure prediction analysis, with a view to determining whether hORFX is a functional homologue of suGF1. hORFX was successfully expressed in vitro, but lacked the ability to specifically bind G-strings. Theoretical predictions suggest that suGF1 has a DNA-binding domain belonging to a different family to that predicted for hORFX, consistent with differences in their respective DNA-binding specificities. suGF1 and hORFX were predicted to have helix-turn-helix and helix-loop-helix DNA-binding domains, respectively. Taken together the results do not support the hypothesis that hORFX is a suGF1 homologue. To date, no direct evidence for the in vivo function of suGF1 has been obtained. With a view to performing transactivation assays in the future, the expression of suGF1 in yeast was investigated in this project. An suGF1 expression construct was engineered and transformed into a protease-deficient yeast strain. Nuclear extracts were prepared and subjected to SOS-PAGE and electrophoretic mobility shift assays (EMSAs). suGF1 was shown to be successfully expressed in yeast cells and exhibited similar G-string-binding properties to that of native and in vitro transcribed and translated (IVT) suGF1. The suGF1 eDNA was also subjected to in si/ico expression, which together with the SDSPAGE results of yeast nuclear extracts and IVT suGF1, indicated that the protein might be expressed as multiple truncated products, due to the utilisation of multiple AUG translation start sites. These in vitro results are crucial for the ultimate outcome and correct interpretation of future transactivation experiments and lay the foundation for further investigation into the possible role of suGF1 in transcriptional regulation.
AFRIKAANSE OPSOMMING: In die verlede is bewys dat die seepampoentjie G-string-bindende faktor (suGF1) hoë affiniteit en spesifisiteit vir aaneenlopende volgordes van deoksiguanosien residue besit. Hierdie DNA motief kom algemeen voor in die stroom-op gebiede van verskeie gene in verskillende organismes. Daar is 'n veronderstelling dat suGF1 betrokke is by die regulering van geenuitdrukking. Vroeër is bewys dat homopurien.homopirimidien-ryke areas die vermoë besit om in vitro ongewone DNA-strukture te vorm. Die potentiaal van die suGF1-bindingsetel om ongewone DNA-strukture te vorm is gevolglik deur sirkulêre dikroïsme (SD) analise ondersoek. Vergelyking van die spektra vir B-DNA-, tripleks- en kwadrupleks-strukture met dié van die suGF1-bindingsetel, toon duidelik dat laasgenoemde 'n mengsel van ongewone DNA konformasies, onder die spesifieke eksperimentele omstandigehede, aanneem. Deeglike inspeksie van die beskikbare geen- en proteïendatabasisse vir alle spesies het aangetoon dat suGF1 geen merkbare kDNA- of proteïenhomoloë besit nie. As gevolg van die belang van soogdiermodelsisteme in die mediese wetenskappe, asook die onbeskikbaarheid van seepampoentjie-sellyne, is 'n soektog na 'n funktionele suGF1 homoloog in soogdiere geloods. Die ontdekking van só 'n homoloog sal dit moontlik maak om die rol van hierdie potensiaal belangrike en unieke DNA-bindingsproteïen te ondersoek. Tydens hierdie soektog is spesiale analise-programme gebruik en 'n potensiële menshomoloog van suGF1, hORFX, is geïdentifiseer. Die mees prominente ooreenkoms tussen die twee proteïene is die soortgelyke rangskikking van funksionele motiewe. Gevolglik is die DNA-bindings eienskappe van die hORFX-proteïen ondersoek, insluitende 'n detaileerde struktuur-funksie-voorspelling ten einde vas te stel of dit wél 'n homoloog van suGF1 is. hORFX is suksesvol uitgedruk in vitro, maar besit nie die vermoë om dieselfde G-string waaraan suGF1 spesifiek bind te herken nie. Teoretiese analise het voorspel dat suGF1 en hORFX aan verskillende DNA-bindings proteïen-families behoort, aangesien suGF1 'n heliks-draai-heliks en hORFX 'n heliks-lus-heliks motief bevat. Hierdie inligting, tesame met die eksperimentele resultate, dui aan dat hORFX nie 'n homoloog van suGF1 is nie. Tot op hede is daar niks bekend aangaande suGF1 se funksie in vivo nie. Met die oog op transaktiveringseksperimente in die toekoms, is die ekspressie van suGF1 in gisselle tydens hierdie navorsingsprojek ondersoek. 'n suGF1 ekspressievektor is berei en gebruik om 'n protease-negatiewe gissellyn te transformeer. Kernekstrakte is ondersoek deur SDS-PAGE en elektroforetiese mobiliteitsessais. Daar is gevind dat suGF1 suksesvol uitgedruk is in die gisselle. Die rekombinante suGF1 besit G-volgorde bindingsaktiwiteite soortgelyk aan dié van suGF1 in kernekstrakte van seepampoentjies, asook in vitro getranskribeerde-en getransleerde suGF1. Die kDNA vir suGF1 is ook in silico uitgedruk. Tesame met die SDS-PAGE-resultate het laasgenoemde aangetoon dat die suGF1-kDNA veelvuldige AUG-kodons bevat vir die inisiasie van proteïentranslasie. Dit lei moontlik tot die translasie van 'n reeks proteïenprodukte wat verkort is aan die N-terminale kant, afgesien van die volledige suGF1-proteïen. Die in vitro resultate in geheel is essensieel vir die toekomstige uitvoering en interpretasie van transaktiveringseksperimente. Hierdie projek lê gevolglik die fondasie vir 'n verdere ondersoek na die rol van suGF1 in die regulering van geenuitdrukking.
35
HLEBIK, SVIATLANA. "BASEL III GLOBAL LIQUIDITY RISK REGULATION FOR BANKING SYSTEMS AND THE ECB QUANTITATIVE POLICY." Doctoral thesis, Università Cattolica del Sacro Cuore, 2016. http://hdl.handle.net/10280/12570.
Full textAbstract:
Questa tesi analizza un tema fondamentale e nello stesso tempo controverso: il rischio di liquidità che, dopo la crisi del 2007-2008, sta diventato sempre più importante. Le banche centrali forniscono la liquidità necessaria per ridurre la probabilità di un collasso del sistema finanziario, utilizzando una vasta gamma di strumenti. La tesi in oggetto propone un’analisi della politica quantitativa della Banca Centrale Europea: un’analisi in cui sono state considerate le condizioni di mercato e la loro coerenza con la domanda di liquidità da parte del sistema bancario.
Il quadro normativo internazionale Basilea III ha introdotto nuove regole per la gestione del rischio di liquidità. Questo lavoro presenta una serie di azioni che possono essere applicate per migliorare le capacità di gestione del rischio di liquidità della banca stessa. Applicando al processo decisionale il metodo della simulazione, è stata utilizzata un'analisi di sensitività per determinare l'impatto delle decisioni manageriali sull’indice di liquidità.
Questa tesi mette in evidenza l'importanza del rischio di liquidità e presenta l'analisi empirica che ha permesso l'indagine della relazione che intercorre tra il nuovo requisito introdotto dal Basilea in materia di liquidità (NSFR) e la stabilità del sistema bancario, i fattori macroeconomici e dei mercati finanziari, e le operazioni della banca centrale.This thesis focuses on a crucial and controversial issue - liquidity risk. After the 2007-2008 crisis it became increasingly important. The Central Banks provide required liquidity to minimise the probability of a financial system meltdown by using a wide array of instruments. This thesis proposes an analyses of the European Central Bank quantitative policy, market conditions in which these measures have been taken, and their consistency with the demand for liquidity by the banking system. The Basel III international regulatory framework introduced new liquidity regulations for managing liquidity risk. This study introduces a number of actions that can be performed to improve a bank’s liquidity risk management capabilities. By applying the simulation-based approach to decision making, a sensitivity analysis was used to determine the impact of managerial rulings on liquidity ratio. The present work highlights the importance of the liquidity risk and presents the empirical analysis that allowed the exploration of the relationship between the Basel’s new liquidity requirement (NSFR) and banking stability, macroeconomic and financial markets factors, and central bank operations.
36
Corrigan, Laura. "Regulation and reproductive functions of membrane-bound vesicles secreted by the Drosophila male accessory gland." Thesis, University of Oxford, 2014. http://ora.ox.ac.uk/objects/uuid:673d46a5-ba88-42d2-9361-51f04d61e01b.
Full textAbstract:
Membrane-bound vesicle secretion provides a novel intercellular communication mechanism, whose roles and regulation remain poorly characterised, particularly in vivo. I have identified two classes of lipid-containing, vesicle-like structures secreted into seminal fluid by epithelial cells of the Drosophila male accessory gland (AG). Exosomes, one class of membrane-bound vesicle formed inside late endosomal multivesicular bodies, are specifically secreted by secondary cells (SCs). The unusual cell biology of SCs allowed me to develop a powerful new high resolution in vivo system to characterise the mechanisms underlying intracellular membrane trafficking events underlying exosome biogenesis using real-time live imaging. I characterise how specific ESCRTs (endosomal sorting complexes required for transport) control SC exosome biogenesis, and identify a novel role for BMP signalling in regulating endolysosomal trafficking events necessary for exosome secretion. I also identify roles for epidermal growth factor receptor (EGFR) and phosphatidylinositide 3-kinase (PI3K) signalling in exosome biogenesis. Importantly, SC exosomes are transferred to females during mating. Here, they fuse with sperm, mirroring in vitro interactions between human prostate exosomes and sperm, and interact with the female reproductive tract epithelium. Blocking SC exosome production specifically suppresses post-mating effects on female receptivity to remating, demonstrating that exosomes have an important reproductive signalling function in vivo, directly or indirectly reprogramming female cells. Finally, I show that main cells, the major epithelial AG cell type, shed lipid-containing microvesicle-like structures from their apical surface. Remarkably, these vesicles carry the seminal peptide, sex peptide, into females during mating and also contribute to the anterior mating plug. In summary, my data reveal previously unsuspected roles for exosomes and microvesicles in Drosophila reproduction that may be evolutionarily conserved. Since these vesicles mediate physiological processes previously thought to involve soluble peptides, my work suggests that current models explaining male reprogramming of female behaviours in flies and higher organisms need substantial revision.
37
Aljagthmi, Amjad Ahmed. "The regulation of small GTPase Rac1 phosphorylation, activation and subcellular localization by ΔNp63α." Wright State University / OhioLINK, 2021. http://rave.ohiolink.edu/etdc/view?acc_num=wright1629746909185699.
Full text
38
Fujita, Yasuyuki. "Phosphorylation of Munc-18/n-Secl/rbSecl by Protein Kinase C - Its Implication in Regulating the Interaction of Munc-18/n-Secl/rbSecl with Syntaxin." Kyoto University, 1997. http://hdl.handle.net/2433/202212.
Full text
39
Austin, Heather L. (Heather Lara) 1984. "Effect of Hypo-osmotic Stress on Mortality and Regulation of Volume, Osmolality, and Magnesium Ion Concentrations in the Sea Anemone Metridium senile in South Slough, Coos Bay, Oregon." Thesis, University of Oregon, 2009. http://hdl.handle.net/1794/10150.
Full textAbstract:
xv, 151 p. : ill. A print copy of this thesis is available through the UO Libraries. Search the library catalog for the location and call number.The sea anemone Metridium senile occurs along a salinity gradient in the South Slough Estuary, Oregon, where it is subjected to frequent and sometimes large fluctuations in salinity. This study determined how hypo-osmotic stress contributes to the survival and distribution of this population. In the laboratory, chronic exposure ofM. senile to 50% and 75% seawater for twenty-eight days resulted in partial regulation of volume and magnesium ions. Anemones transplanted to the field exhibited increased mortality and partial regulation of volume, osmolality, and magnesium ions with decreased salinity during the wet season (December-February) and less regulation during the dry season (June-August). This pattern of physiological tolerance coincides with observed trends of seasonal abundance and distribution. Previous studies describe M senile as a marine osmoconformer, however this estuarine population is able to withstand moderate hypo-osmotic stress through partial regulation of tissue osmolality and magnesium ions.
Committee in Charge: Dr. Craig M. Young, Chair; Dr. Nora B. Terwilliger; Dr. Steven S. Rumrill; Dr. Caren E. Braby
40
Vallejos, Vidal Eva Carolina. "molecular regulation of the immune function in the gills of gilthead sea bream (sparus aurata) fed with immunostimulant diets." Doctoral thesis, Universitat Autònoma de Barcelona, 2015. http://hdl.handle.net/10803/319686.
Full textAbstract:
En los últimos 10 años, diferentes inmunoestimulantes han sido probados en más de 18 especies de peces, incluyendo carpa, turbot, salmón del atlántico, dorada, trucha, entre otros. Los compuestos que han sido estudiados son muy variados e incluyen componentes bacterianos, polisacáridos, extractos de plantas, algas y animales, factores nutricionales, e incluso hormonas y citoquinas. Sin embargo, a pesar del gran interés que han generado estos estudios, los inmunoestimulantes dietarios comercialmente disponibles contienen principalmente sólo β-glucanos. La mayoría de los estudios están basados en la respuesta celular de los peces, como actividad fagocítica, especies reactivas de oxígeno (ROS), y mediciones en sangres, como contenido de IgM en suero. La gran mayoría de estos estudios han mostrado resultados positivos, pero se sabe muy poco sobre los mecanismos moleculares que hay detrás de la respuesta a la administración de inmunoestimulantes a través de la dieta. Por lo anteriormente mencionado, el objetivo principal de este trabajo es evaluar a respuesta transcriptómica de las branquias de peces alimentados con dietas inmunoestimulantes, utilizando dos acercamientos, el molecular y celular.
Experimentalmente, 360 doradas (Sparus aurata) sanas, de un peso promedio de 38±7.3 g fueron separados en 27 tanques y alimentados con dos dietas inmunoestimulantes manufacturadas por Skretting (Dieta A y Dieta B) y una dieta control (Dieta C, Skretting). Cada dieta fue administrada los peces a una razón del 3% de su masa corporal dos veces al día, con un periodo de pre-aclimatación de 14 días. Muestras de agallas fueron tomadas a 2, 7, 14 y 28 días de administración de la dieta. Todas las muestras fueron divididas en dos para realizar un análisis de microarray (Microarray específico para dorada 44K, diseñado por Agilent) y para un análisis in situ. Los datos de microarray fueron analizados con dos métodos, con un análisis referente al control y un análisis en loop. Los resultados del microarray mostraron la expresión diferencial de genes relacionados a procesos inmunológicos, como inflamación, activación y respuesta de células T, apoptosis, entre otros, sin embargo la intensidad y magnitud de la respuesta no fue muy alta. Los resultados del análisis in situ mostró que algunos de estos transcritos se localizaron en un tipo celular ubicado en la lamela secundaria de las agallas de dorada. Estas células, podrían ser células clorhídricas o linfocitos T, pero más estudios hacen falta para poder confirmar estas hipótesis.Over the past 10 years, different immunostimulants have been tested in more than 18 fish species including: Carp, Yellow croaker, Turbot, Atlantic salmon and Seabream, amongst others. The compounds tested are varied including bacterial components, polysaccharides, animal, plant and algae extract, nutritional factors, and even hormones and cytokines and some synthetics such as Levamisole. However even although a lot of interest and studies have been carried out, commercially available immunostimulant diets mainly contain β-glucans. The majority of the studies reported are based upon cellular response assays such as phagocyte activity and ROS and simple blood measurements such as total serum IgM content. All studies have shown positive results, but little is known about the underlying molecular response to dietary administration of immunostimulants. In order to evaluate the transcriptomic response in gills we analyzed and evaluated gene expression profiles associated with exposure to immunostimulant diets over time, using both a molecular and cellular approach. Experimentally, 360 healthy Gilthead Seabream (Sparus aurata) of average body weight of 38±7.3 g were separated in 27 tanks and fed with two Skretting immunostimulant diets (Diet A and Diet B) and a control diet (Diet C). Each diet were fed at a feeding rate of 3% of body weight twice daily for 28 days with a period of 14 days of pre-acclimation. Gills samples were taken at 2, 7, 14 and 28 days post diet. All samples were divided for microarray analysis (specific Sparus aurata 44K microarray, Agilent custom design) and in situ hybridization (ISH) analysis. A diet dependent and a loop analysis were carried out, with control diet as a reference point. Microarray results shown a differential expression of genes associated to immunological processes such as inflammation, T and B cell response amongst others but the intensity and magnitude of the modulation of these responses was not high. ISH analysis showed localization of immunological transcripts in a specific cellular type in the primary lamellae of gilthead seabream gills.
41
Lung, Tina Kathy. "Analysis of Mouse EKLF/KLF2 E9.5 Double Knockout: Yolk Sac Morphology and Embryonic Erythroid Maturation." VCU Scholars Compass, 2007. http://hdl.handle.net/10156/1821.
Full text
42
Warner, Frendehl Sipaco. "Caught between 'Dublin' and the deep blue sea: 'small' Member States and European Union 'burden-sharing' responses to the unauthorized entry of seabourne asylum seekers in the Mediterranean from 2005-2010." Thesis, University of Canterbury. National Centre for Research on Europe, 2013. http://hdl.handle.net/10092/9231.
Full textAbstract:
The Dublin Regulation determines the Member State responsible for accepting and making a decision on asylum claims lodged in the European Union (‘EU’), Norway and Iceland. It aims to ensure that each asylum claim is examined by one and only one Member State, to put an end to the practice of ‘asylum shopping’ and to prevent repeated applications, both of which have been costly for the receiving Member States and caused severe inefficiencies in the determination processes in the EU in the past.
With the first Member State of entry being the major determinant for the allocation of asylum responsibility under the Dublin Regulation, there has been growing discontent among Member States at the external borders of the EU, particularly the southern Member States in the Mediterranean, over what they see as a system that has unjustly placed disproportionate burdens on them regarding the admission of seaborne asylum seekers and the costs associated with it. As a result of changes in migration rules and consequent adjustments in the entry strategy employed by irregular migrants and people smugglers, the Member States at the EU’s ‘southern frontline’ have unwillingly played the role of reluctant hosts to boatloads of unwelcome asylum seekers.
This thesis aims to examine how the EU has attempted to tackle the challenging situation of the unauthorised migration of asylum seekers into its territory by sea, and in particular, how it has responded to demands from affected Member States for a more equitable system of asylum responsibility allocation in spite of and outside the Dublin framework. It would argue that the ‘small’ EU Member States in the Mediterranean themselves have, over the last five years at least, become the unexpected drivers of the EU’s declared commitment to the principles of ‘solidarity’, ‘fair sharing of responsibility’ and ‘effective multilateralism’.
‘ Small’ as they may be in terms of resources, size or influence vis-à-vis the larger Member States, the former have been able to create their own mark in a global regime that has traditionally been resistant to the idea of burden-sharing. The measures taken by the EU’s ‘southern frontline’ have collectively changed the landscape of a global protection regime where not only is asylum ‘burden sharing’ highly elusive – its terms and conditions are also dictated by the more powerful sovereign states. While the theoretical point of departure in this study is the influence wielded by the ‘small’ EU Member States in the burden-sharing debate, the degree or level of ‘influence’ small Mediterranean Member States can exercise in pushing for cooperative arrangements is itself determined by a system that is biased towards large states, increasingly securitised, and is therefore limited in both nature and scope. Nevertheless, the experience of ‘burden-sharing’ in the EU between 2005 and 2010 demonstrates that the Member States at the periphery have proactively taken the responsibility for the operationalisation of the founding values and principles of the EU, and through active norm advocacy and related strategies, have been able to achieve what has eluded the global protection regime so far – a refugee burden sharing scheme.
43
RUBASHKINA, YANA. "Rigore della Politica Ambientale: Misura ed Effetti." Doctoral thesis, Università Cattolica del Sacro Cuore, 2014. http://hdl.handle.net/10280/5966.
Full textAbstract:
-The PhD thesis is about measurement and effects of environmental policy in the context of the Porter Hypothesis (PH). The first chapter offers a critical review of the large empirical literature on the Porter Hypothesis. The second chapter presents an empirical investigation of the Porter Hypothesis focusing on the manufacturing sectors of European countries between 1997 and 2009. We look at overall innovation and productivity impact that are the most relevant indicators for the “strong” PH. This approach allows us to account for potential opportunity costs of induced innovations. As a proxy of environmental policy stringency we use pollution abatement and control expenditures (PACE), which represent one of the few indicators available at the sectoral level. We remedy upon its main drawback, that of potential endogeneity of PACE, by adopting an instrumental variable estimation approach. The third chapter represents a novel approach, inspired by the literature on multilevel latent models and Item Response Theory, to assessing countries’ environmental and energy policy performance. We use data on energy efficiency policy targeting industrial sectors in 27 EU countries between 2004 and 2009 and rank countries with respect to their ability to implement policy over time. Unlike previous contributions in this respect, our model accounts for the inherent difficulty of a given policy instrument mix. Moreover, the model is extended to deal with the longitudinal data and to adjust the country ranking as a result of economic and institutional observables, which are likely to affect policy design and implementation.
44
Hannesson, Magnus K. "Carriage by sea : the nature of transport documents, carriers and regulation by mandatory conventions; a study in English and Scandinavian law." Thesis, University of Exeter, 1991. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.280665.
Full text
45
Hustedt, Sina. "A Risk Analysis of New Zealand's Biosecurity Management System along Three Sea Importation Pathways." Thesis, University of Canterbury. School of Forestry, 2010. http://hdl.handle.net/10092/3635.
Full textAbstract:
It is widely acknowledged that international trade is a major pathway for the spread of invasive species. International agreements and domestic legislation aim to reach a balance between facilitating trade and providing nations with the right to protect their
environmental, public and economic health. This is achieved through the development of standards that prescribe procedures that must be followed before a commodity is imported. Under Section 22 of the Biosecurity Act (1993) Biosecurity
New Zealand of the Ministry of Agriculture and Forestry (MAF) develops import health standards for the importation of commodities and sea containers and for the approval and management of transitional facilities.
Under current regulations, before being allowed to enter New Zealand, a sea container must first be accompanied by appropriate documentation for the sea container itself and any contents (this includes cargo manifests, any required treatment certificates for the cargo and cleaning certificates for the sea container itself). Upon arriving in New Zealand the sea container is transported to a transitional facility for inspection and unloaded once biosecurity clearance has been obtained. There are approximately 7,000 transitional facilities (both on and off wharf) throughout New Zealand and
inspections are conducted by persons that have obtained accreditation from MAF for inspections (MAF accredited persons).
Based on current importation procedures and other information made available, mathematical models were developed for three sea importation pathways (sea containers, woodpackaging and used vehicles) that involved the inspection of imported units by MAF accredited persons. These models were designed to predict the effectiveness of the current border inspection policies and procedures. Inspection accuracy was found to have the most influential impact on slippage (the rate at which
contamination passes through border procedures undetected) along the measured pathways. Under current conditions, an estimated 5.75% of all sea containers, 4.12% of all sea containers containing woodpackaging and 1.63% of all used vehicles that
enter New Zealand annually are contaminated in some manner despite having biosecurity clearance. A 3% increase in inspection efficiency reduced slippage to 0.5% of sea containers, 2.16% of woodpackaging and 0.001% of used vehicles
entering New Zealand annually.
Given that the accuracy of the inspection was the most influential aspect of the border management procedures, mathematical models were develop to predict the cost of compliance recovered by MAF if all inspections were conducted by MAF inspectors
as apposed to MAF accredited persons. Under current regulations the cost of compliance (if MAF inspector conducted inspections of all imported units) was estimated to be $117.36 million for sea containers, $35.16 million for woodpackaging
and $5.44 million for used vehicles. Increasing the inspection accuracy to the ideal 100% increased the cost of compliance by 75.36%, 61.96% and 61.92% for sea containers, woodpackaging and used vehicles respectively.
These findings indicate that Government investment in the training of inspectors
throughout New Zealand would improve current border detection rates. Under current regulations, the cost incurred by MAF inspectors inspecting all imported units is recoverable. Currently the cost of compliance is approximately 1% of the value of
annual imports. These costs are seen by the import sector as part of their daily business and understand that these measures are in place for the long term sustainability of their businesses (Anon. 2005).
46
Kihara, Akio. "Identification,characterization,and regulation of the proteolytic system that degrades uncomplexed SecY subunit of protein translocase in the Escherichia coli plasma membrane." 京都大学 (Kyoto University), 1998. http://hdl.handle.net/2433/157158.
Full textAbstract:
本文データは平成22年度国立国会図書館の学位論文(博士)のデジタル化実施により作成された画像ファイルを基にpdf変換したものであるKyoto University (京都大学)
0048
新制・課程博士
博士(理学)
甲第7164号
理博第1938号
新制||理||1043(附属図書館)
UT51-98-G93
京都大学大学院理学研究科化学専攻
(主査)教授 伊藤 維昭, 教授 井上 丹, 教授 三木 邦夫
学位規則第4条第1項該当
47
Månsson, Gustav, and Henrik Stale. "Kosten ombord : Hur vill sjömannen att kostregleringen ska se ut?" Thesis, Linnéuniversitetet, Sjöfartshögskolan (SJÖ), 2013. http://urn.kb.se/resolve?urn=urn:nbn:se:lnu:diva-30420.
Full textAbstract:
Diet is mentioned by many seamen as a subject of joy and aims to give nutritional value and sufficient energy to manage a long working day at sea. The purpose with this investigation is to examine if there is a need among seamen to receive more information about diet regulations onboard and if they wish that it was shaped differently to meet their demands. The study is based on a literature part where diet regulations are examined and an interview part with semi structured qualitative interviews with five seamen. The conclusion of the study indicates that seamen have limited knowledge about the enunciation of the regulation, where it is to be found and consider it to be imprecise. Interviews showed that seamen believe that variety is the most important factor in diet intake and it was this expression that they primarily wanted stated in the regulations. There are legitimate reasons to assume that Livsmedelsverket´s (compare NFA) recommendations also are applicable regarding diet at sea. A good diet is not only good for the individual’s health but also gains including safety and quality of work performed.Kosten anges av många sjömän som ett glädjeämne ombord och ska ge den näring och energi som krävs för att orka med en lång arbetsdag på sjön. Syftet med denna studie var att undersöka om det finns ett behov hos sjömän att få mera information om kostregleringen ombord och om de önskar att den vore utformad annorlunda för att möta deras krav. Arbetet baseras på en litteraturdel där kostregleringen undersöks och en intervjudel med semistrukturerade kvalitativa intervjuer med fem sjömän. Sammanfattningsvis tyder vår undersökning på att sjömän har bristande kännedom om regleringens utformning, var den återfinns samt anser att den är oprecis. Intervjuerna visade att sjömän anser att variation är den viktigaste faktorn i kostintaget och det var också detta uttryck som främst önskades framgå av regleringen. Det finns välmotiverade skäl att utgå från Livsmedelsverkets rekommendationer även på sjön. Ett bra kostintag är inte bara bra för individens hälsa utan ger också vinster i bland annat säkerheten och kvaliteten på utfört arbete.
48
Khan, Faisal Farooq. "Design, implementation and experimental validation of a network-based model to predict mitotic microtubule regulating proteins." Thesis, University of Oxford, 2013. http://ora.ox.ac.uk/objects/uuid:7c27b09b-08c3-43f5-93c3-0580cf5fd103.
Full textAbstract:
The purpose of this thesis was to study mitosis in Drosophila, from a network biology perspective. The primary aim was to develop and test a network-based prediction model that could integrate available data in public databases (like Flybase) and, based on that, predict potential mitotic proteins. The approach taken to design the protein interaction network included the use of a priori knowledge about the microtubule composition of the mitotic spindle and the higher likelihood of microtubule-associated proteins (MAPs) to have a putative mitotic function. The design also included the integration of different complementary datasets, from gene expression and functional RNAi screens to cross species conservation of MAPs for fitting a network-based model for predicting mitotic proteins. I begin with the creation of the MAP interactome based on a MAP dataset in Drosophila. This initial network was extended by transferring homologs and interologues of MAP datasets from four other species, i.e. human, mouse, rat and Arabidopsis. These proteins were then used as seed proteins to conduct a virtual pull-down experiment, by adding indirect interactors into the network, i.e. proteins that directly bind to two or more MAPs within the network, which completed the MAP interactome. Data from genome-wide studies in Drosophila were gathered for each node in the MAP interactome. These ‘layers’ of data were then used as features to fit a prediction model that could score each node in the network, based on the likelihood of its role in mitosis. The final model performed with 96% accuracy after 10-fold cross validation and was used to rank all the proteins in the MAP interactome. By analysing the top 100 high scoring predicted mitotic proteins, a highly connected cluster of 33 proteins was identified that was subject to experimental validation in the lab. The first approach was to conduct an in vitro analysis using an RNAi screen to test for any spindle, chromosome or centrosome phenotypes upon gene knockdown. After two independent RNAi screens, around 80% of the proteins produced mutant mitotic phenotypes strongly supporting the results of the MAP prediction model. The second approach was to conduct an in vivo analysis by expressing GFP- fusion constructs of selected genes from the subcluster. These were expressed in Drosophila early embryos to study their subcellular localization during interphase and mitosis. A variety of localizations were observed ranging from chromatin and microtubules to more generic cytoplasmic localizations. These results suggested not all predicted proteins were co-localizing with microtubules, and therefore might not necessarily be microtubule associated proteins but can possibly be functioning as microtubule associated regulator proteins. Proteomics analysis of a subset of these genes showed a large proportion of false positive interactions but also picked new interactions between member proteins that highlighted a module within the subcluster. The RNAi hits from the in vitro analysis and the members of the module within subcluster-16 from the in vivo analysis provide interesting subjects for further characterization.
49
Buglass, Surahanil Katrin. "Regulating stem cell fate within microenvironmental niches." Thesis, University of Oxford, 2014. http://ora.ox.ac.uk/objects/uuid:75f9498c-30f0-4983-84b2-dd58f2ccf52b.
Full textAbstract:
Improving the repopulation potential of human umbilical cord blood (UCB) haemopoietic stem cells (HSCs) remains a paramount goal in HSC transplantation (HSCT) therapy. This implies enhancing the homing and engraftment potential of UCB-CD34+CD133+ cells to the bone marrow (BM). Although an array of molecules continues to be identified as ‘key’ homing molecules, the molecular mechanisms controlling HSC homing are still not fully understood. The regulatory implications of hypoxia in the BM, with the concomitant stabilisation of hypoxia inducible transcription factor-1α (HIF-1α), are becoming more apparent, yet at the commencement of this thesis no study had explored whether hypoxia induced signalling can be adopted to regulate the homing and engraftment of transplanted HSCs. The aim of this DPhil project was thus to investigate whether hypoxic conditions as detected in the BM influence the adhesion of UBC-CD133+ cells to osteoblasts, BM stromal cells and BM endothelial cells-60 (BMEC-60), as well as their transmigration towards chemokine SDF-1α across BMEC-60. Increasing the exposure of UCB-CD133+ cells to 1.5% O2 doubled the percentage of transmigrating cells (p<0.05), and while hypoxia stimulated UCB-CD133+ cells preferentially adhered to IL-1β stimulated BMEC-60, their adhesion to non-stimulated (BMEC-60) was significantly improved (p<0.001). To help unravel the underlying molecular mechanisms, we attempted to examine the potential involvement of hypoxia regulated scaffolding protein HEF-1/NEDD9/Cas-L (HEF-1) in the increased percentage of migrating UCB-CD133+ cells after hypoxia pre-conditioning. The role of HEF-1 in HSCs is unexplored, and its multifunctional contribution in a variety of processes including cell migration, attachment and invasion make HEF-1 a prime candidate as a contributing homing molecule. After identifying a suitable short-hairpin RNA (shRNA) sequence to knockdown HEF-1, generating lentiviral (LV)-particles in house and optimising transduction protocols, HEF-1 knockdown was achieved in haemopoietic model cell lines KG-1 and KG-1A (KG-1/KG-1A–HEF1). Significantly decreased KG-1A–HEF1 cell adhesion to non-stimulated BMEC-60 was detected. Together, these studies provide a promising platform to further explore the role of HEF-1 in hypoxia induced UCB-CD133+ cell transmigration towards the key homing molecule SDF-1α.
50
Van, Nieuwerburgh Lies. "Experimental Studies on the Regulation of Pigment Dynamics in Phytoplankton and Copepods by Dissolved Inorganic Nutrients." Doctoral thesis, Uppsala : Acta Universitatis Upsaliensis : Univ.-bibl. [distributör], 2004. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-4230.
Full text