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1
Turcu, Eugen Florin. "Micropatterning and microelectrochemical characterisation of biological recognition elements." [S.l. : s.n.], 2004. http://deposit.ddb.de/cgi-bin/dokserv?idn=973183624.
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Casuso, Páramo Ignacio. "Electrical Characterization of Biological Elements by Atomic Force Microscopy." Doctoral thesis, Universitat de Barcelona, 2008. http://hdl.handle.net/10803/1519.
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The assessment of the electrical properties of biomolecules at the nanoscale becomes necessary for gathering previous basic knowledge and for the control of the biosensor fabrication. I developed instrumentation, protocols, and theoretical frameworks for the nanoscale electrical characterization of biomolecules by AFM. Two novel types of AFM electrical characterizations were developed: electron transport through the biomolecules and dielectric polarization of the biomolecules (each one requires different instrumentation, protocols and theory). I succeeded in obtaining important electrical information on individual biomolecules with implications in electrical biosensor fabrication.KEY WORDS: AFM, Protein, Electrical, Biosensor
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Winkler, Wade C. "RNA elements required for T box antitermination." The Ohio State University, 2002. http://rave.ohiolink.edu/etdc/view?acc_num=osu1381251178.
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GRANT, TYRE D. "ASSESSING THE ENVIRONMENTAL AND BIOLOGICAL IMPLICATIONS OF VARIOUS ELEMENTS THROUGH ELEMENTAL SPECIATION USING INDUCTIVELY COUPLED PLASMA MASS SPECTROMETRY." University of Cincinnati / OhioLINK, 2004. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1085590907.
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Worrasettapong, Watcharapong. "Ultratrace analysis and speciation studies on trace elements in environmental and biological samples." Thesis, University of Sheffield, 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.269381.
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Hutchinson, Robert William. "Measurement of proteins and elements in biological samples by inductively coupled plasma mass spectrometry." Thesis, University of Sheffield, 2008. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.505564.
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Tetreault, Hannah M. "Transposable element contribution and biological consequence of genome size variation among wild sunflower species." Diss., Kansas State University, 2016. http://hdl.handle.net/2097/32897.
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Doctor of PhilosophyDivision of Biology
Mark C. Ungerer
Nuclear genome size varies immensely across flowering plants, spanning nearly 2400-fold. The causes and consequences of this vast amount of variation have intrigued biologists since it became clear that nuclear DNA amount did not reflect organismal complexity (the so-called C-value paradox). In my dissertation I utilize wild sunflower species in the genus Helianthus to examine the role of transposable elements (TEs), and in particular, long terminal repeat (LTR) retrotransposons, in generating genome size variation and whether variation in genome size influences aspects of plant growth and development across multiple organizational levels. The genus Helianthus provides an excellent system for studying these questions given four-fold variation in nuclear DNA content among diploid species and well-resolved phylogenetic relationships. Utilizing short-read Illumina data and sequence information from a diverse panel of Helianthus annuus (common sunflower) full-length LTR retrotransposons, I found that nuclear genome size in Helianthus species is positively correlated with repetitive DNA, and LTR retrotransposon subtypes generally show similar patterns in genomic abundance across taxa. Helianthus species with the largest genomes, however, exhibit large-scale amplification of a small number of LTR retrotransposon subtypes. Measuring aspects of plant growth and development at cell-, organ- and whole plant-levels in a panel of diploid Helianthus species that vary 4-fold in nuclear genome size, I found that genome size is negatively correlated with cell production rate, but that this negative correlation does not persist at higher organizational levels. Taken together, these results provide insights into the mechanisms contributing to genome size evolution in plants and the organizational level at which genome size may impact growth patterns and developmental rates. Genome expansion in wild sunflowers is influenced most significantly by amplification of a small number of TEs and not necessarily by a greater diversity of TEs. Genome size is strongly negatively correlated with cell production rate but this relationship weakens at higher organizational levels, such as that of organ and whole-plant development.
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Yu, Liwen Schwartz Martin. "Computational studies on Group 14 elements (C, Si and Ge) in organometallic and biological compounds." [Denton, Tex.] : University of North Texas, 2007. http://digital.library.unt.edu/permalink/meta-dc-3591.
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Yu, Liwen. "Computational Studies on Group 14 Elements (C, Si and Ge) in Organometallic and Biological Compounds." Thesis, University of North Texas, 2007. https://digital.library.unt.edu/ark:/67531/metadc3591/.
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A series of computational studies were carried out on Group 14 (C, Si and Ge) elements in organometallic and biological compounds. Theoretical studies on classical and H-bridged A3H3+ (A=C, Si and Ge) as p ligands with different organometallic fragments at B3LYP and B3P86 level reveal a reverse charge transfer from ligand to metal in Si and Ge complexes whereas in C complexes there is a small charge transfer from metal to ligand. The H-bridged complexes are more stable than the complexes based on Si3H3+ and Ge3H3+ ligands with terminal hydrogens. The stability of the bridged systems increases from Si to Ge. Corrective scale factors for computed harmonic CºO vibrational frequencies for 31 organometallic complexes have been determined at the HF and B3LYP levels. The scaled B3LYP frequencies exhibit a greater reliability than do HF frequencies. Experimental data have shown that Si/Ge-substituted decapeptides are advantageous over their C analog in vitro and in vivo studies in modern hormone therapy. A computational investigation was carried out on the synthesized decapeptides focusing on position 5 containing Si and Ge. The results have shown that there are some differences in C, Si and Ge-containing analogs. However, further investigations are needed to elucidate the observed advantages of Si/Ge over C analogs.
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Roberts, Sabrina B. "The roles of Correia Repeat Enclosed Elements in regulation of gene expression in the Neisseria spp." Thesis, Kingston University, 2017. http://eprints.kingston.ac.uk/41954/.
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In February 2017, the World Health organization published a list of 12 antibiotic-resistant "priority pathogens" that pose the greatest threat to human health. Amongst these, in the high priority group was 'Neisseria gonorrhoea'. When considering 'N. meningitdis' the highest rates of incidence are seen in infants with peak seen in adolescents and the elderly in some countries. CREE have been indentified near virulence and metabolic genes as well being present in the pathogenic 'Neisseria' species. It was therefore seen as an interesting area to undertake gene expression research. To look at the transcriptome and effective method of RNA extraction needed to be considered. Experiments found that the Qiagen RNeasy kit was the most successful kit to extract RNA from cultures of 'N. gonorrhoeae' and 'N. meningitidis'. This research, in the assessment of the transcriptome, has demonstrated that the presence of CREE is associated with the presence on ncRNAs in the genome. CREE locations in the neisserial genomes are frequently found near or overlapping SIPHT predicted ncRNAs. The transcriptome has also shown that CREE can invert at its location with the potential to impact gene expression. Research set out in this thesis has set the ground work for some interesting areas to be taken up for further investigation.
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ABDEL, AZIM ANNALISA. "From CO2 to CH4 via biological methanation." Doctoral thesis, Politecnico di Torino, 2018. http://hdl.handle.net/11583/2708490.
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The leitmotif of this Ph.D. thesis is represented by carbon dioxide (CO2) recycling via biological production of methane (CH4).
This work particularly focuses on the physiology of three hydrogenotrophic methanogens, Methanothermobacter marburgensis (M. marburgensis), Methanothermococcus okinawensis (M. okinawensis) and Methanococcus maripaludis S2 (M. maripaludis), that can be used as catalysts for biological methane production (BMP) process. This CO2 recycling method is challenging due to an inefficient transfer rate of molecular hydrogen (H2) from the gas phase to the liquid phase. Thus, the biocatalyst performance is limited by H2 availability in the liquid medium. However, several factors, as strain type and media requirements, operating conditions, and reactor design, can contribute to the success of CO2 conversion to CH4. Understanding the physiology of methanogens is a powerful tool for developing a scalable BMP process. Therefore, a novel study on the role of trace metals in pure cultures of M. okinawensis and M. marburgensis respectively is herein proposed. Experimental method of this study included an in silico analysis, closed batch, and fed-batch cultivations. In silico analysis revealed genomic differences among the transport systems and enzymes related to the methanogenesis pathway of these two methanogens. The importance of Fe as metal cofactor in methanogenesis emerged from the in silico analysis and it has been confirmed by the closed batch and fed-batch experiments. M. okinawensis responded to rising concentrations of trace element (TE) by increasing specific growth rate (µ, h-1) and volumetric productivity of methane (MER, mmolL-1h-1) during closed batch cultivation. Furthermore, M. okinawensis shown growth and CH4 in fed-batch cultivation. On the base of fed-batch cultures results, M. marburgensis was prioritized and applied for CO2-based BMP process optimization. It has been proposed a new feeding strategy based on exponential fed-batch cultivation where different medium-, TE- and sulphide dilution rates combinations, and different CO2/H2 inflow rates corresponded to a defined run. The specific setting of each run produced different responses from M. marburgensis. In this context, a MER of 476 mmol L-1 h-1 and µ of 0.69 h-1 were eventually achieved at highest H2/CO2 gassing rate and ratio. However, if these factors mitigate the limitation due to the H2 mass transfer on one side, they also reduce CH4 purity in the offgas on the other side. The combined effect of increasing TE dilution and H2/CO2 gassing rates positively affected the biomass and biomass concentration. Among trace elements, there are heavy metals whose toxicity is higher than others. Heavy metals can seriously affect the functionality of microorganisms, and therefore compromise their performances as biocatalysts of a bio-based process. Not only metals, but also organic compounds, such as carboxylic acids, can damage cells survival. Thus, the second experimental part of this thesis deals with inhibition studies on pure culture of M. maripaludis in closed batch cultivation. Despite the potential applications of M. maripaludis, the knowledge surrounding this strain runs out of lab-scale studies concerning the physiology and toxicology of heavy metals and VFAs. Therefore, M. maripaludis growth and productivity were tested by using copper (Cu), zinc (Zn), acetate (Ac) and propionic acid (Pr) as potential inhibitors of microbial activity. The culture was totally inhibited at concentration of 30, 70 and 100 mgL-1 of Cu and 0.7 and 1 gL-1 of Zn. However, M. maripaludis shows tolerance to 3, 7 and 10 mgL-1 of Cu with different extent. The addition of 0.3 gL-1 of Zn to the medium, rather promoted the biomass build-up of M. maripaludis and cancelled the effect of Cu when used together in the medium. In this study, it has been supported that the inhibition by Cu is due to a reduced or suppressed activity of the CODH/ACS complex producing acetyl-CoA intermediate. Acetyl-CoA is the precursor of many metabolic subsystems (e.g. lipid, amino acids, nucleotides pathways) and its alteration would interfere with them. While CODH/ACS activity is supported by CO2 and methanogenesis intermediate, the other way to produce acetyl-CoA is based on the acetate:CoA ligase. The relevance and the tolerance to rising concentrations of Ac and Pr was also investigated and quantified via HPLC analysis. Concentration of 5 and 10 mgL-1 of acetate did not inhibit nor growth neither productivity. Interestingly, the deprivation of acetate not only impacted on the growth rate but also on methanogenesis in M. maripaludis. In absence of Ac, the same concentrations of Pr caused a slow-down of the growth, while productivity was not touched. This study sheds light on the individual and combined impact of Cu, Zn, acetate and propionic acid on the metabolism of M. maripaludis. Furthermore, an attempt to define a possible mechanism which regulates specific acetate capture is provided in this study and the relevance of acetate:CoA ligase respect to CODH/ACS complex for acetyl-CoA synthesis is herein discussed. The information collected in this study are essential to improve the process efficiency of CO2 conversion to CH4 and extend the knowledge on the physiology of certain compounds. The tendency of these methanogens to adapt to adverse conditions, most of the time, offers the possibility to improve the engineering aspects of a limited process toward an unlimited one. Moreover, as a future activity, this thesis proposed the use of a 10-bar pressure bioreactor which has been projected in the frame of the Ph.D. research with a view to improving the success of biological CH4 production.
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COCCARO, DANIELA M. B. "Estudo da determinacao de elementos - tracos em liquens para monitoracao ambiental." reponame:Repositório Institucional do IPEN, 2001. http://repositorio.ipen.br:8080/xmlui/handle/123456789/10844.
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Dissertacao (Mestrado)
IPEN/D
Instituto de Pesquisas Energeticas e Nucleares - IPEN/CNEN-SP
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Grant, Tyre D. "Assessing the environmental and biological implications of various elements through elemntal speciation using inductively coupled plasma mass spectrometry." Cincinnati, Ohio : University of Cincinnati, 2004. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=ucin1085590907.
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Mustafa, Suhad As'ad. "The development of genetically engineered bacterial enzymes as sensor biological recognition elements for the detection of drugs and explosives." Thesis, Bangor University, 2010. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.540409.
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Mountfort, Simon A. "The development of secondary io mass spectrometry for the analysis of aluminium and other trace elements in biological tissue." Thesis, University of Newcastle Upon Tyne, 1993. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.357231.
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Nguyen, Van Dang. "A finite elements method to solve the Bloch-Torrey equation applied to diffusion magnetic resonance imaging of biological tissues." Palaiseau, Ecole polytechnique, 2014. http://pastel.archives-ouvertes.fr/docs/00/95/77/50/PDF/thesis_Dang.pdf.
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L'imagerie de résonance magnétique de diffusion (IRMD) est une technique d'imagerie non-invasive qui donne l'accès aux caractéristiques de diffusion de l'eau dans des tissus biologiques, notamment, dans le cerveau. Les restrictions que la structure cellulaire microscopique impose à la diffusion des molécules d'eau, sont agrégées statistiquement dans un mesurable signal d'IRMD macroscopique. L'inférence de la structure microscopique du tissu à partir du signal d'IRMD permet de détecter des régions pathologiques et d'observer les propriétés fonctionnelles du cerveau. A cet effet, il est important de mieux comprendre la relation entre la microstructure du tissu et le signal d'IRMD ce qui nécessite des nouvelles outils numériques capable de faire les calculs dans des géométries complexes modèles des tissus. Nous proposons une telle méthode numérique basée sur les éléments finis linéaires ce qui permet de décrire précisément des géométries complexes. La discrétisation par des éléments finis est couplée à la méthode adaptative des pas de temps de Runge-Kutta Chebyshev. Cette méthode qui assure la convergence du second ordre à la fois en temps et en espace, est implémentée sous la plateforme FeniCS C++. Nous utilisons aussi le générateur de maillage Salome pour travailler de manière efficace avec des géométries périodiques à plusieurs compartiments. Nous considérons quatre applications de la méthode pour étudier la diffusion dans des modèles à plusieurs compartiments. Dans la première application, nous étudions le comportement au temps long et démontrons la convergence d'un coefficient de diffusion apparent vers un tenseur de diffusion effectif obtenu par l'homogénéisation. La deuxième application vise à vérifier numériquement qu'un modèle à deux compartiments permet d'approximer le modèle à trois compartiments dans lequel le compartiment cellulaire et le compartiment extra-cellulaire sont complétés par un compartiment membranaire. La troisième application consiste à valider le modèle de Karger du signal d'IMRD macroscopique qui prend en compte l'échange entre compartiments. La dernière application se focalise sur le signal d'IMRD issu des neurones isoles. Nous proposons un modèle efficace unidimensionnel pour calculer le signal d'IRMD de manière précise dans un réseau des neurites de rayons variés. Nous testons la validité d'une expression semi-analytique du signal d'IRMD issu des réseaux de neuritesDiffusion magnetic resonance imaging (dMRI) is a non-invasive imaging technique that gives a measure of the diffusion characteristics of water in biological tissues, notably, in the brain. The hindrances that the microscopic cellular structure poses to water diffusion are statistically aggregated into the measurable macroscopic dMRI signal. Inferring the microscopic structure of the tissue from the dMRI signal allows one to detect pathological regions and to monitor functional properties of the brain. For this purpose, one needs a clearer understanding of the relation between the tissue microstructure and the dMRI signal. This requires novel numerical tools capable of simulating the dMRI signal arising from complex microscopic geometrical models of tissues. We propose such a numerical method based on linear finite elements that allows for a more accurate description of complex geometries. The finite elements discretization is coupled to the adaptive Runge-Kutta Chebyshev time stepping method. This method, which leads to the second order convergence in both time and space, is implemented on FeniCS C++ platform. We also use the mesh generator Salome to work efficiently with multiple-compartment and periodic geometries. Four applications of the method for studying the dMRI signal inside multi-compartment models are considered. In the first application, we investigate the long-time asymptotic behavior of the dMRI signal and show the convergence of the apparent diffusion coefficient to the effective diffusion tensor computed by homogenization. The second application aims to numerically verify that a two-compartment model of cells accurately approximates the three-compartment model, in which the interior cellular compartment and the extracellular space are separated by a finite thickness membrane compartment. The third application consists in validating the macroscopic Karger model of dMRI signals that takes into account compartmental exchange. The last application focuses on the dMRI signal arising from isolated neurons. We propose an efficient one-dimensional model for accurately computing the dMRI signal inside neurite networks in which the neurites may have different radii. We also test the validity of a semi-analytical expression for the dMRI signal arising from neurite networks
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Bernhard, Max [Verfasser], Gerhard [Akademischer Betreuer] Thiel, and Bodo [Akademischer Betreuer] Laube. "Binding Proteins and Receptor Binding Domains as Sensor Elements for Biological and Artificial Nanopores / Max Bernhard ; Gerhard Thiel, Bodo Laube." Darmstadt : Universitäts- und Landesbibliothek, 2021. http://d-nb.info/1236344782/34.
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Lam, Rebecca. "Investigation of two solid sample introduction techniques for the analysis of biological, environmental, and pharmaceutical samples by inductively coupled plasma spectrometry." Thesis, McGill University, 2006. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=102993.
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In this thesis, new approaches to direct trace metals analysis of solid samples by inductively coupled plasma spectroscopy were investigated using laser ablation and thermal vaporization systems for solid sample introduction of biological, environmental, and pharmaceutical samples.Laser ablation with inductively coupled plasma atomic emission spectroscopy (ICP-AES) and inductively coupled plasma mass spectrometry (ICP-MS) was applied to pharmaceutical tablets. Precision of analysis depended on laser parameters and could be improved using signal ratios. The feasibility of using laser ablation-ICP-MS for detecting natural levels of mercury along a single human hair strand was also demonstrated.
As well, the use of an induction-heating electrothermal vaporizer (IH-ETV) coupled to an ICP-MS was successful in determining mercury concentrations in a single human hair strand. Methodologies for multielement analysis of powdered hair were also explored using IH-ETV-ICP-MS. While calibration by reference hair materials showed promise, calibration methods by liquid standards were not suitable for any element. Detection limits achieved for most elements were below natural levels found in human hair.
IH-ETV-ICP-AES was also applied to the analysis of analyze-laden chromatographic powder. This study showed potential problems that may arise due to the methodology taken to analyze such materials. Finally, recommendations for future investigations and methodologies for laser ablation and thermal vaporization are discussed.
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CHIADO', ALESSANDRO. "Evaluation of new biorecognition elements for environmental monitoring." Doctoral thesis, Politecnico di Torino, 2013. http://hdl.handle.net/11583/2511708.
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To date, environmental monitoring is mainly focused on traditional chemical techniques, or on the assessment of specific biomarkers. However, these analyses are affected by several limitations: mainly, they are expensive, spot-sampling and time-consuming. In order to overcome these drawbacks, new biological monitoring methods, such as biosensors and biological early warning system (BEWS) are under development. These kinds of devices, built around whole cells, enzymes and antibodies, are well-suited to cooperatively and continuously monitor the environmental conditions. The key-factor of this very promising approach is the biological sensing element. Whole cell systems and enzymes are well suited for environmental monitoring: they are able to determine the bioavailable and toxic concentration of xenobiotics, especially if the source and nature of the compound cannot be predicted. Microorganisms usually detect a broad spectrum of chemicals, and represent a good opportunity for low cost, long shelf-life, and wide range of conditions in which they can be applied. Besides, enzymes are effective when a particular kind of pollutant would be detected because is possible to fine tune their metabolic behaviour by means of protein engineering.
In this work, three biological sensing elements, related to three different index of toxicity were evaluated, in order to develop new biosensors for environmental monitoring: a broad toxicity index associated to the decrease of light emission (EC50 or half effective concentration) of a bioluminescent bacterium, Vibrio fischeri, a metal toxicity connected to the metal-regulated production of a siderophore (pyoverdine) by the soil and water microorganism Pseudomonas fluorescens, and finally an index of toxicity given by PAHs, was related to the metabolization of these compounds by laccase of Trametes versicolor.
One of the first step during the assessment of a new biological sensing element is the study of the effect of physical-chemical parameters. The tested physical-chemical parameters (temperature, pH, inoculum percentage (v/v) and carbon source) influenced both microbial sensible elements (V. fischeri and P. fluorescens), therefore, these sensible elements can be used in a whole-cell biosensor for in-situ application, even if the response is affected by the environmental variables. Furthermore, the light emission of V. fischeri was highly variable, although a more stable bioluminescence was obtained by means of a glucose fed-batch: this is one step towards the direct application of this system, usually tailored for laboratory assays, to estimate the broad acute toxicity directly in situ in a portable device.
Regarding the interaction between P. fluorescens and Fe3+, Cu2+, and Zn2+, the minimum inhibitory concentration (MIC) and the pyoverdine critical concentration (PCC) obtained values were compared to those indicated in the WHO Guidelines for drinking water quality and in European directive 98/83/EC: MICs of Fe3+, Cu2+ and Zn2+ are always above the threshold specified, whilst PCCs are very near to the recommended thresholds for iron and copper. The PCC was not determined for zinc in the tested range of concentration and conditions. These results highlighted that this sensible element should be further investigated for the development of a biosensor able to monitor metals in the environment.
The last and most promising sensing element assessed in this work was the lccβ laccase of T. versicolor. A combination of computational docking (SwissDock) and molecular biology techniques was used to generate rationally engineered laccases with increased ability to process large and persistent PAHs. These mutated isoforms were produced by heterologous expression in P. pastoris, successfully purified, and characterized by means of biochemical assays. The activity of the enzymes was initially tested and characterized with phenolic and non phenolic substrates at different pH (3.0-8.0): the best mutated enzyme F162A/L164A (M1) showed an increased specific activity (UI/mg) in comparison with the wild type, in every tested condition. This result was in agreement with those obtained by computational docking simulations (estimated free binding energy), validating the rational design approach.
Moreover, decolourization assays of large aromatic dyes, used as model compounds, have shown that the mutated enzymes are reactive towards molecules with chemical structure resembling that of aromatic organic pollutants. By means of example, enzyme mutants with a larger binding pocket (e.g. M1) showed higher activity against triphenylmethane dyes (e.g. Methyl Green), especially without a mediator of the reaction (HBT), and high stability under a variety of temperature conditions (4, 22 °C, room temperature). Therefore, the best enzyme should be integrated on an appropriate transducer (e.g. electrode), and coupled to a wireless platform generating a BEWS for environmental monitoring.
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MAIHARA, VERA A. "Avaliacao do conteudo de alguns elementos essenciais e toxicos em dietas de criancas e idosos pelo metodo de analise por ativacao de neutrons." reponame:Repositório Institucional do IPEN, 1996. http://repositorio.ipen.br:8080/xmlui/handle/123456789/10445.
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Tese (Doutoramento)
IPEN/T
Instituto de Pesquisas Energeticas e Nucleares - IPEN/CNEN-SP
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Beach, Andrew C. "Distribution and concentration of trace and major elements in biological specimens using proton induced X-ray emission analysis and photon transmission tomography." Thesis, University of Surrey, 1994. http://epubs.surrey.ac.uk/842826/.
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Trace elements within biological tissues are heterogeneously distributed. This complicates the task of deriving concentrations that represent an organ or specimen as a whole. The derivation of representative concentrations is important in the investigation of tissue health status or exposure to the individual from occupational or man-made pollution sources. Therefore, a knowledge of the elemental dispersions in biological tissues is required. Proton induced X-ray emission (PIXE) analysis is employed in the study of the elemental heterogeneity of porcine liver, kidney, heart and lung. Specimens are analysed in two different modes. One method involves the extraction of sub-samples that are dried, homogenised and manufactured into thick target pellets. This approach however limits the spatial resolution on which elemental distributions may be derived and hence thick specimen sections that can be irradiated directly may be preferred. This type of target though suffers in that surfaces are irregular and proton irradiation and X-ray take-off angles are ill defined. The effect of these surface imperfections upon X-ray yield in PIXE are investigated by the development of simple stylised models. The physical parameters of these models are varied and the elements most affected and dominant factors in modifying X-ray yield are identified. The trace element content for like tissues between targets in the form of pellets and freeze-dried sections are compared and mostly excellent correlation is found. The analysis of specimens in either of these modes stresses the high elemental inhomogeneity of biological samples. A quantitative determination of this elemental heterogeneity is made by the derivation of sampling factors, the minimum mass of material required to reduce elemental variations to a given level of precision. Those sampling factors derived by utilising the data from pelletised targets agree well with the limited values from the literature, whereas a large difference is found for those calculated from thick specimen target sections. This disagreement is thought to be due to the failure of sampling factor theory at the small sampling mass employed in the analysis of the latter targets. Photon transmission tomography was investigated for the ability of the technique to provide a measure of biological specimen heterogeneity, differentiate between different composite tissues and identify regions of interest. This may prove useful for the selection of sub-samples for subsequent trace element analysis. Biological specimens were scanned in fresh and dry states to ascertain the most favourable sample preparation technique to best achieve the above aims, the dry sample states were preferred. Freeze-dried specimens are imaged under differing scanning parameters and their data compared to theoretical values derived from PIXE and Rutherford backscattering (RBS) analysis. Good agreement is found. Regions of interest may be identified in tomographs, this being due to density variations rather than elemental variations, tissues of similar but different composition not being differentiatable due to image noise which is a product of finite counts in reconstructed images. However, with the improvement of photon counting statistics in images, these tissues may be more discernible from one another in tomographs thus making photon transmission tomography a viable technique for the selection of representative sub-samples for subsequent elemental analysis.
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Fuga, Alessandra. "Uso de líquens epifíticos no biomonitoramento da poluição atmosférica da região metropolitana de São Paulo." Universidade de São Paulo, 2006. http://www.teses.usp.br/teses/disponiveis/85/85131/tde-15052012-133838/.
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Devido aos crescentes problemas relacionados com a poluição atmosférica na região metropolitana de São Paulo que atingem o ambiente e a saúde das populações, toma-se de grande interesse o estabelecimento de metodologias tal como a de monitoramento da qualidade do ar usando organismos cosmopolitas. O biomonitoramento é um método experimental que permite avaliar a resposta de organismos vivos à poluição, oferecendo vantagens como custos reduzidos, eficiência no monitoramento de amplas áreas geográficas e de elementos químicos poluentes presentes em baixas concentrações no ambiente e acumulados no biomonitor ao longo de um período. No presente trabalho, o método de análise por ativação neutrônica foi aplicado à determinação de elementos acumulados em amostras do fungo liquenizado Canoparmelia texana coletadas em duas áreas distintas: (1) Parques Estaduais Carlos Botelho (PECB) e Intervales (PEI), área considerada não-poluída pertencente ao ecossistema de Mata Atlântica - SP e (2) área metropolitana de São Paulo em pontos localizados nas proximidades das estações automáticas de monitoramento da Companhia de Tecnologia de Saneamento Ambiental (CETESB). Os liquens coletados dos troncos de árvores foram previamente limpos, moídos e posteriormente irradiados com nêutrons do reator IEA- R1 juntamente com os padrões sintéticos dos elementos. A precisão e exatidão dos resultados analíticos foram avaliadas por meio das análises dos materiais certificados de referência IAEA-336 LICHEN e Mixed Polish Herbs (INCT-MPH-2). Os resultados obtidos nestes materiais de referência foram concordantes com os valores certificados e apresentaram, em geral, uma boa precisão com coeficientes de variação variando de 0,9 a 14,6%. Os resultados das análises de liquens indicaram que os elementos As, Co, Cr, Cs, La, Mo, Sb, Sc, Se e U estão presentes aos níveis de ng g-1, Ba, Br, Cl, Fe, K, Mn, Na, Rb e Zn aos niveis de mg g-1 e Ca aos níveis de μg g-1. Por meio da aplicação das análises de cluster e de discriminate, aos resultados obtidos nas amostras coletadas em áreas com diferentes níveis de poluição, os pontos de amostragens foram agrupados segundo similaridades químicas no que diz respeito às suas composições elementares. Também foi observado que as amostras do PECB e do PEI separaram-se dos grupos e subgrupos formados pelas amostras da região metropolitana e este resultado indica a preservação das áreas consideradas não-poluídas. Os liquens coletados no PEI apresentaram, em geral, concentrações inferiores àquelas obtidas para a região metropolitana de São Paulo principalmente para os elementos relacionados com ações antrópicas. Os mapas de distribuição das concentrações de elementos permitiram a visualização e identificação de pontos que apresentam concentrações de elementos mais altas na região metropolitana. Estes mapas de distribuição também mostraram que a poluição na região metropolitana de São Paulo apresenta perfis diferentes devido às inúmeras fontes de emissão de poluentes. Os elementos determinados nos liquens da área metropolitana indicaram ser de origens industrial, veicular e do solo. Os resultados obtidos neste trabalho mostraram a viabilidade do uso da C. texana na avaliação da poluição no biomonitoramento passivo de diversos elementos contaminantes presentes na atmosfera da região metropolitana de São Paulo.Due to the increasing problems of atmospheric pollution in the Sao Paulo metropolitan region that affect the environment and human health the application of biomonitoring methodologies using cosmopolite organisms has now become relevant. Biomonitoring is a method to evaluate the response of live organisms to pollution. This method offers advantages such as reduced costs, efficient monitoring of large geographic areas and accumulated pollutants over a large period in which low concentrations of chemicals elements in the environment can be evaluated. In the present study, neutron activation analysis method was applied to determine elements accumulated in Canoparmelia texana lichenized fungi. Samples were collected in two distinct areas: Carlos Botelho (PECB) and Intervales (PEI) State Parks that are considered as non-polluted areas and that belong to the Atlantic Forest - SP ecosystem; and Sao Paulo city metropolitan region in sites near automatic monitoring stations of the Environmental Protection Agency of the State of Sao Paulo (CETESB). The lichens collected from the bark of the trees were properly treated, and irradiated with neutrons from IEA-R1 nuclear reactor along with synthetic standards of elements. The precision and the accuracy of the results were evaluated by the analyses of IAEA-336 LICHEN and Mixed Polish Herbs (INCT -MPH-2) certified reference materials. The results obtained for these materials were in accordance with the certified values and presented good precision with variation coefficients ranging from 0.9 to 14.6%. Results obtained for lichens showed that elements As, Co, Cr, Cs, La, Mo, Sb, Sc, Se and U are present at ng g-1 levels, Ba, Br, Cl, Fe, K, Mn, Na, Rb and Zn at μg g-1 and Ca at mg g-1. By applying cluster and discriminant analyses to the results for the lichen samples from areas with different levels of pollution, the sampling sites were grouped according to their chemical similarities and their elemental composition. It was also observed that samples from PECB and PEI were separated from groups and subgroups formed by the samples from the metropolitan region. This result indicates the preservation of PECB and PEI areas considered non-polluted. The lichens collected in the PEI presented, in general, lower concentrations of the elements than those from the metropolitan region of São Paulo in regards to those elements related to anthropogenic actions. The distribution maps of element concentrations allowed identification of sites in the metropolitan region that present higher elemental concentrations. Furthermore the distribution maps also showed that the pollution in the metropolitan region presents different profiles due to many sources and different pollutant emissions. The probable sources of elements determined in lichens from the metropolitan region are industrial, vehicular and soil. Results obtained indicate that the C. texana species can be used as a passive biomonitor of element pollution in the Sao Paulo metropolitan area. This species is abundant in both polluted and non-polluted areas and thus allows to distinguish regions with distinct levels of pollution.
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Liakaitė, Lina. "Biologinių preparatų įtaka žieminių rapsų vystymuisi." Master's thesis, Lithuanian Academic Libraries Network (LABT), 2012. http://vddb.laba.lt/obj/LT-eLABa-0001:E.02~2012~D_20120613_114201-66463.
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Magistrantūros studijų baigiamojo darbo tyrimų tikslas buvo įvertinti skirtingų biologinių preparatų, kaip dirvos aktyvatorių, naudojamų rudenį ant priešsėlio (žieminių kviečių) ražienų, bei pavasarį, rapsams esant butonizacijos tarpsnyje, poveikį žieminių rapsų vystymuisi bei derliaus formavimuisi. Lauko eksperimentas buvo atliktas 2010–2011 m. ASU Bandymų stotyje. Dirvožemis IDg8-k (LVg-p-w-cc) – karbonatingas sekliai glėjiškas išplautžemis (Calc(ar)i-Epihypogleyic Luvisols).
Darbo objektas – Žieminis rapsas (Brassica napus ssp. oleifera), linijinė veislė ‘Sunday’.
Darbo metodai: Žieminių rapsų biometriniai matavimai, sėklų derlingumas bei derliaus struktūros elementai nustatyti tiesioginio matavimo, skaičiavimo ar svėrimo būdu pagal priimtas lauko eksperimento vykdymo metodikas. Tyrimų duomenys statistiškai įvertinti vieno veiksnio arba dviejų veiksnių kiekybinių požymių dispersinės analizės metodais, taikant kompiuterinę programą ANOVA (Tarakanovas, Raudonius, 2003).
Darbo rezultatai. Esmingai didžiausias žieminių rapsų šaknies kaklelio skersmuo (13 mm) prieš augalų žiemojimą nustatytas variante, kur ant žieminių kviečių ražienų buvo išpurkštas biologinių preparatų Azofit (1,0 l ha-1) ir Amalgerol (3,0 l ha-1) derinys. Šiame variante peržiemojo 9,73 % daugiau augalų nei kontroliniame. Esmingai didžiausias žieminių rapsų sėklų derlingumas (3,25 t ha-1) gautas variante, kuriame Azofit (1,0 l ha-1) ir Amalgerol (3,0 l ha-1) derinys išpurkštas rudenį ir pavasarį, tai 1,5 t... [toliau žr. visą tekstą]The main objective of Master thesis research was to evaluate various biological agents, as soil activators, which are used in the fall on the preceding crop (winter wheat) stubble and in spring on rape at bud formation stage, and the impact that these biological agents do to winter rapeseed crop development and formation. Field experiment was conducted in 2010–2011 at ASU Experimental Station. The soil type – Calc(ar)i-Epihypogleyic Luvisols (LVg-p-w-cc). The object – winter rape (Brassica napus ssp. Oleifera) linear sort 'Sunday'. Working methods: biometric measurements of winter rape, seed yield and yield structure elements were determined while using direct measurements, calculations or weighing according field experimental techniques. Research data have been statistically evaluated with a single factor or two factor analysis of variance of quantitative methods of evidence, using a computer program ANOVA (Tarakanovas, Raudonius, 2003). Research results. The biggest winter rape root collar diameter (13 mm) before winter was found in variant, where the winter wheat stubble was sprayed with the combination of biological preparations Azofit (1.0 l ha-1) and Amalgerol (3.0 l ha-1). In this variant 9.73% more plants survived winter than in control field. The biggest winter rapeseed yield (3.25 t ha-1) was obtained in the variant where a combination of Azofit (1.0 l ha-1) and Amalgerol (3.0 l ha-1) was sprayed in the autumn and spring, it was 1.5 t ha -1 higher than in the... [to full text]
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FUGA, ALESSANDRA. "Uso de liquens epifíticos no biomonitoramento da poluição atmosférica da região metropolitana de São Paulo." reponame:Repositório Institucional do IPEN, 2006. http://repositorio.ipen.br:8080/xmlui/handle/123456789/11482.
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
Dissertação (Mestrado)
IPEN/D
Instituto de Pesquisas Energeticas e Nucleares - IPEN/CNEN-SP
FAPESP:03/03387-1
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Kangueehi, Grace Nandesora. "Nutrient requirement and distribution of intensively grown 'Brookfield Gala' apple trees /." Thesis, Link to the online version, 2008. http://hdl.handle.net/10019/853.
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SEMMLER, MARILIA G. M. C. "Biomonitoração de Hg, Cd, Pb e outros elementos em áreas costeiras do estado de São Paulo por meio de mexilhão transplantado Perna Perna (LINNAEUS, 1758)." reponame:Repositório Institucional do IPEN, 2007. http://repositorio.ipen.br:8080/xmlui/handle/123456789/11569.
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Tese (Doutoramento)
IPEN/T
Instituto de Pesquisas Energéticas e Nucleares-IPEN-CNEN/SP
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Brockman, John Douglas. "Investigation of K₀ neutron activation analysis at MURR and investigation of the toenail as a biomonitor for Mg, Zn, Cu, Se and Hg." Diss., Columbia, Mo. : University of Missouri-Columbia, 2006. http://hdl.handle.net/10355/5890.
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Thesis (Ph. D.)--University of Missouri-Columbia, 2006.The entire dissertation/thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file (which also appears in the research.pdf); a non-technical general description, or public abstract, appears in the public.pdf file. Title from title screen of research.pdf file (viewed on August 13, 2007) Vita. Includes bibliographical references.
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Virbalytė, Ieva. "Januliškio girininkijos medynų vertinimas biologinės įvairovės požiūriu." Master's thesis, Lithuanian Academic Libraries Network (LABT), 2012. http://vddb.laba.lt/obj/LT-eLABa-0001:E.02~2012~D_20120620_151042-91167.
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Magistro darbe vertinama medynų įvairovė biologinės įvairovės požiūriu ir nustatomos teritorijos palankiausios biologinei įvairovei ir jos apsaugai.
Darbo objektas – VĮ Švenčionėlių miškų urėdijos Januliškio girininkijos teritorija.
Darbo tikslas – įvertinti Januliškio girininkijos medynus biologinės įvairovės požiūriu ir nustatyti palankiausiais biologinei įvairovei ir jos apsaugai teritorijas.
Darbo metodai – 1975 m., 1985 m., 1999 m., ir 2009 m. miškotvarkų duomenų analizavimas ir nustatytų medynų rūšinės įvairovės rodiklių vertinimas, bei remiantis girininkijoje esančiomis saugomomis teritorijomis, kertinėmis miško buveinėmis ir retomis rūšimis, charakterizuojama girininkijos biologinė įvairovė ir nustatomos jos koncentracijos vietos.
Darbo rezultatai. Atlikus tyrimus nustatyta, kad Januliškio girininkijoje tenkančio miško masyvo dalyje 1975 m. augo 6, 1985 m. – 7, o 1999 – 2009 m. po 9 medžių rūšių. Tai lėmė liepos, baltalksnio, ąžuolo, uosio, gluosnio ir maumedžio atsiradimas medynuose. Nagrinėjimu laikotarpiu yra pastebimas pušynų mažėjimas, jie sumažėjo 6,4%, tačiau tuo pačiu laikotarpiu yar fiksuojamas eglynų kiekio didėjimas medynų sudėtyje. Jų kiekis medyne padidėjo 4%. Nagrinėtų įvairovės, proporcingumo bei vyravimo rodiklių dinamika rodo medynų rūšinės įvairovės didėjimą iki 1985 m. ir mažėjimą po 1985 m. Nagrinėjant atskirų augaviečių medynų rūšinės įvairovės dinamiką 1975 – 2009 m., pastebėta, kad didžiausia rūšinė įvairovė buvo Nb, Nc, Lc ir Uc augavietėse... [toliau žr. visą tekstą]In this final master degree work the stands of Januliškis Forestry are evaluated from the perpective of biodiversity and the most favorable environment for biodiversity and it‘s protection is determined. The object of the work – The teritory of SE Švenčionėliai State Forest Januliškis Forestry. The aim of the study – To evaluate Januliškis Forestry stands from the perspective of biodiversity and to determine the most favorable teritories for biodiversity and it‘s protection. Working methods – the analysis of 1975 yr., 1985 yr., 1999 yr., and 2009 yr. data about forest order, the assessment of stands‘ species diversity rates and the characterization of the forestry biological diversity and determination of concentration points based on protected teritories, key biotopes and rare species that are found in the teritory of particular forestry. Study results – The reasearch showed that in the part of the forest which belongs to Juniliškis Forestry in 1975 there were 6 tree species, in 1985 – 7, and in 1999 – 2009 there could be found 9 tree species. This happened due to linden, gray alder, oak, ash, willow and larch stands appearance. In the analyzed period the decrease in number of pines by 6,4% can be observed, on the other hand, at the same time the increase in number of spruces by 4 % is traced. The dynamics of analyzed diversity, proportion and predominance rates indicates the growth of stands‘ species diversity till 1985 and it‘s abatement after 1985. While analysing the... [to full text]
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SEIXAS, TERCIA GUEDES. "INFLUENCE OF ECOLOGICAL AND BIOLOGICAL PARAMETERS ON THE ACCUMULATION OF ESSENTIAL (SE, AS, CU) AND NON-ESSENTIAL ELEMENTS (HG, CD, AG, PB) BY THE LIVER AND KIDNEY OF CETACEANS FROM THE WESTERN SOUTH ATLANTIC OCEAN." PONTIFÍCIA UNIVERSIDADE CATÓLICA DO RIO DE JANEIRO, 2008. http://www.maxwell.vrac.puc-rio.br/Busca_etds.php?strSecao=resultado&nrSeq=12974@1.
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PONTIFÍCIA UNIVERSIDADE CATÓLICA DO RIO DE JANEIROCOORDENAÇÃO DE APERFEIÇOAMENTO DO PESSOAL DE ENSINO SUPERIOR
CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO
Neste estudo, avaliou-se a influência de alguns parâmetros ecológicos e biológicos sobre a acumulação dos elementos- traço e mercúrio orgânico (HgOrg)no fígado e rins de espécies de cetáceos de hábitos costeiros (Pontoporia blainvillei, N = 31; Sotalia guianensis, N = 21) e oceânicos (Stenella coeruleoalba, N = 3; Stenella frontalis, N = 4), acidentalmente capturados em duas áreas distintas da costa brasileira (tropical - litoral do norte do estado do Rio de Janeiro e subtropical - litoral do estado do Rio Grande do Sul). Assim, foram gerados novos dados a respeito das concentrações destes elementos em órgãos de cetáceos marinhos ainda pouco estudados, especialmente em uma região com pouca informação como a porção oeste do Oceano Atlântico Sul. Para tal, foram aplicados métodos analíticos baseados na técnica da espectrometria de absorção atômica (AAS), utilizando a espectrometria de absorção atômica com forno de grafite (GF-AAS) e a espectrometria de absorção atômica com vapor frio (CVAAS), as mais frequentemente aplicadas para a determinação de elementos-traço e mercúrio respectivamente, em amostras biológicas. Estas técnicas apresentaram ótima precisão e exatidão comprovadas através da análise de materiais de referência certificados (CRM) do National Research Council - Canadá (DORM-2, DOLT-2 e TORT-2). Foram observadas diferenças regionais (região tropical e subtropical) e inter-específicas (golfinhos de hábitos costeiro e oceânico) sobre a acumulação dos elementos- traço e HgOrg nos órgãos estudados. As espécies de hábito oceânico apresentaram as maiores concentrações destes elementos em seus órgãos. O sexo dos indivíduos não influiu na bioacumulação dos elementos e HgOrg. Os parâmetros população, comprimento total, e maturidade sexual, influenciaram na acumulação dos elementos-traço e HgOrg em ambos os órgãos, de acordo com a espécie e a área de captura. S. guianensis, co- habita o mesmo ambiente que P. blainvillei, e preferencialmente se alimenta de peixes maiores e predadores, neste estudo, apresentou a razão molar de 1:1 entre o Se e o Hg,mostrando assim, que provavelmente o processo de destoxificação de metilmercúrio hepático esteja ocorrendo. A espécie P. blainvillei se alimenta preferencialmente de cefalópodes e peixes pequenos, e apresentou uma razão molar de 4:1 entre o Se e o Hg no fígado. Os metais de transição Cd e Ag, que também interagem com o Se hepático nos mamíferos, apresentaram correlações significativas no fígado dos cetáceos marinhos estudados. A espécie S. guianensis apresentou correlações significativas entre as concentrações molares de Se e Cd (p = 0,01) e Se e Ag (p < 0,001) no fígado. Para a espécie P. blainvillei, os indivíduos provenientes de ambas as regiões (tropical e subtropical) apresentaram correlações significativas entre as concentrações molares de Se e Hg (p < 0,001) no fígado. Somente os indivíduos de P. blainvillei capturados na região tropical apresentaram correlações significativas entre as concentrações molares de Se e Cd (p < 0,001). Não só as diferentes condições ambientais, mas também, o tempo de vida, o estágio de crescimento e, principalmente a preferência alimentar, influenciaram fortemente sobre a acumulação de elementos- traço e HgOrg nos tecidos dos cetáceos assim como, sobre suas inter-relações.
The present work tested whether ecological and biological parameters have an influence on the accumulation of trace elements and organic mercury (HgOrg) by the liver and kidney of coastal (Pontoporia blainvillei, N = 31; Sotalia guianensis, N = 21) and oceanic (Stenella coeruleoalba, N = 3; Stenella frontalis, N = 4) cetaceans species incidentally caught in fishing nets along two Brazilian coastal areas (tropical - northern Rio de Janeiro State and subtropical -Rio Grande do Sul State). This research added new insight to the existing studies with trace element concentrations in internal organs of marine cetaceans from the southwestern Atlantic Ocean. Few studies have documented trace element concentrations in marine mammals in this area. Analytical methodologies based on atomic absorption spectrometry (AAS), using the graphite furnace (GF-AAS) and cold vapor (CV-AAS) techniques were applied for this purpose. They are the most popular analytical techniques applied for trace element and mercury determination, respectively, in biological samples. Precision and accuracy of the analytical methods were determined and monitored using certified material from National Research Council - Canada (DORM-2, DOLT-2 and TORT- 2). Interspecies (coastal and oceanic cetacean species) and regional (tropical and subtropical regions) differences were observed in the accumulation of trace elements and organic mercury in organs, liver and kidney. The highest concentrations of these elements were observed in the liver of the oceanic cetacean species. However, no gender differences were found on the bioaccumulation of trace elements and also organic mercury. Biological parameters such as, population, body length and sexual maturity influenced on the trace element and organic mercury accumulation by both organs, according to the cetacean species and caught area. S. guianensis, which co- habits the same coastal marine environment that P. blainvillei species, was the only dolphin species that presented a Se:Hg molar ratio close to 1:1, showing that a probable detoxification process can be occurring in the liver of S. guianensis. This dolphin species feeds mainly on predatory fish, while P. blainvillei feeds mainly on fish and cephalopods. P. blainvillei presented a Se:Hg molar ratio close to 4:1. It`s known that transition metals, such as Hg, Cd and Ag, have an interaction with Se in the liver of marine mammals. The molar concentrations of Cd (p = 0.01) and Ag (p < 0.001) presented significant correlations with the hepatic molar Se in the liver of S. guianensis. P. blainvillei from both sampling areas presented a high significant correlation for molar Se to Hg concentrations (p < 0.001) in liver. Meanwhile, only individuals of P. blainvillei from tropical region showed a significant correlation with hepatic Se and Cd (p < 0.001). Based on the results present here, it is possible to conclude that, not only the different environmental conditions, but also life span, growth stage but mainly the feeding habit influenced the accumulation of trace elements and organic mercury by cetacean tissues. These ecological and biological parameters influenced on the inter-element relationships.
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Germanos, Erika. "VARIABILIDADE GENÔMICA DOS ELEMENTOS TRANSPONÍVEIS EM ESPÉCIES DO GRUPO mesophragmatica DO GÊNERO Drosophila." Universidade Federal de Santa Maria, 2005. http://repositorio.ufsm.br/handle/1/5248.
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Coordenação de Aperfeiçoamento de Pessoal de Nível SuperiorThe mesophragmatica group belongs to the radiation virilis-repleta of the Drosophila subgenus, it was established by Brncic and Koref in 1957. The species of this group present some characteristics of isolated endemic species in some places in Andes. The common ancestral of the species of the group seems to have acquired, for selective pressure, genetics structures better adjusted to each region. Although there is just a few studies involving these species and still have to be done in relation to the presence and evolution of transposable elements in its genomes. In this context, the transposable elements of the families, hobo, Tom/17.6, I, mariner, P, micropia and gypsy had been analyzed in species of Drosophila of the mesophragmatica group using, Dot Blot and PCR. The genomic DNA of species D.viracochi, and one of the D. gasici had presented hybridization for the micropia element when analyzed by Dot Blot. Analysis the presence of the TEs of the families Tom, 17.6, hobo was made by PCR. However, they had not been gotten amplicons for none of these elements. However homologous sequences to element P are found in D. gasici and D. pavani. Using probe of the elements I and mariner they had been carried through Dot Blot not presenting hybridization with genomic DNA of species D. pavani, D. brncici, D. viracochi, D. gasici (three different populations). Genomic DNA of species D. pavani, D. brncici, D. viracochi, D. gasici (three different populations) hybridized with probe of the element gypsy also having amplification for PCR for all the analyzed species. The purify products of PCR had been sequenced. Phylogenetic analysis s confirmed the idea that it has incongruence between the phylogeny of the species and of its TEs due to a standard of complex evolution that involves mechanisms as: random losses, vertical and horizontal transference, ancestral polymorphism, different taxes of evolution. Those mechanisms might be not mutually excludable and probably occur simultaneously.
O grupo mesophragmatica pertence à radiação virilis-repleta do sub-gênero Drosophila, foi estabelecido por Brncic & Koref em 1957. As espécies deste grupo apresentam algumas características de espécies endêmicas isoladas em vários locais nos Andes. O ancestral comum das espécies do grupo parece ter adquirido, por pressão seletiva, estruturas gênicas melhor ajustadas a cada região. Embora existam alguns estudos envolvendo estas espécies pouco se sabe em relação à presença e evolução de elementos transponíveis em seus genomas. Neste contexto, os elementos transponíveis das famílias, hobo, Tom/17.6, I, mariner, P, micropia e gypsy foram analisados em espécies de Drosophila do grupo mesophragmatica usando, Dot Blot e PCR. O DNA genômico das espécies D.viracochi, e uma das linhagens de D. gasici apresentaram hibridização para o elemento micropia quando analisadas por Dot Blot. Análise da presença dos TEs das famílias Tom, 17.6, hobo foi feita por PCR. Porém, não foram obtidos amplicons para nenhum destes elementos. No entanto seqüências homólogas ao elemento P estão presentes em D. gasici e D. pavani. Utilizando sonda dos elementos I e mariner foram realizados Dot Blots não apresentando hibridização com DNA genômico das espécies D. pavani, D. brncici, D. viracochi, D. gasici (três linhagens diferentes). DNA genômico das espécies D. pavani, D. brncici, D. viracochi, D. gasici (três linhagens diferentes) hibridizaram com sonda do elemento gypsy havendo também amplificação por PCR para todos as espécies analisadas. Os produtos de PCR purificados foram seqüenciados. Análise filogenética a partir destas seqüências reforçou a idéia de que haja incongruências entre a filogenia das espécies e de seus TEs devido a um padrão de evolução complexa que envolva mecanismos como: perdas estocásticas, transferência vertical e horizontal, polimorfismo ancestral, diferentes taxas de evolução sendo não mutuamente excludentes e provavelmente ocorram simultaneamente.
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Glugoski, Larissa. "Análise de marcadores cromossômicos em Rineloricaria (Siluriformes: Loricariidae) com ênfase na diversidade cariotípica." UNIVERSIDADE ESTADUAL DE PONTA GROSSA, 2017. http://tede2.uepg.br/jspui/handle/prefix/940.
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Previous issue date: 2017-02-23The Loricariidae family is the largest in the Siluriformes order, being comprised of eight subfamilies. One of these, the Loricariinae subfamily, shows great diversity in respect to the number of chromosomes and karyotype formula, varying in the diploid number (2n) from 36 to 74 chromosomes. This diverse range originated mainly from Robertsonian(Rb) rearrangements. Rineloricaria is the largest genre in the Loricariinae subfamily, its species ranging from 2n = 36 to 70 chromosomes. In spite of this, little is known about which kinds of repetitive DNA gave rise to the events of chromosome fusion or fission. Previous studies have revealed the presence of multiple 5S rDNA sites in specimens of Rineloricaria from the Paraná River Basin, associated to the Robertsonian fission/fusion events. The aim of this work was the molecular characterization of the fragile sites associated to the 5S rDNA, besides localizing in situ marker chromosomes in Rineloricaria latirostris from the Das Pedras River and R. latirostris from the Piumhi River (first described in this work), seeking to understand the 2n diversification in this group. Rineloricaria latirostris from the Pedras River exhibited 2n = 46 chromosomes, while those from the Piumhi River presented 2n = 48 chromosomes, and both had a fundamental number (FN) of 60. Fluorescence in situ hybridization (FISH) assays in R. latirostris from the Piumhi River revealed 2 chromosome pairs with 5S rDNA sites, pair 7 with 18S rDNA, and only terminal staining when subjected to a telomeric probe (TTAGGGn). The population of the Pedras river exhibited 5 pairs with 5S rDNA sites, the metacentric (m) pair 2 marked with 18S rDNA, TTAGGGn markers in the terminal regions of the chromosomes, and the presence of interstitial telomeric sites (ITS) in pairs m 1 and m 3. The latter, in synteny with 5S rDNA, is indicative of Robertsonian fusion events. The isolation, cloning and sequencing of the 5S rDNA revealed clones with high sequence identity to 5S rDNA from other species, in addition to the necessary regions for recognition and transcription by RNA polymerase III. One clone of ~700 bp exhibited a degenerated fragment of hAT transposon in its sequence. It was named degenerated 5S rDNA. The fluorescence in situ hybridization assay highlighted chromosomes with co-localized staining for 5S rDNA/hAT, 5S rDNA/degenerated 5S rDNA, and 5S rDNA/ITS (m 3 pair) in R. latirostris from das Pedras River. In R. latirostris from Piumhi River, there was no detection of degenerated 5S rDNA sites. These results allow us to infer the role of the hAT transposon in the dispersion of 5S rDNA sites in the population, since some studies have indicated a relation between 5S rDNA dispersion and transposons in fish. In conclusion, data obtained by this study indicate a possible association between the hAT and the dispersion of 5S rDNA sites and Robertsonian events in the studied population of R. latirostris. The presence of the 5S rDNA/degenerated 5S rDNA/ITS generates hotspots for chromosomal breakage, contributing to the large karyotype diversity found in Loricariidae.
A família Loricariidae é a mais numerosa dentro da ordem Siluriformes e abrange oito subfamílias. A subfamília Loricarinae apresenta uma grande diversidade no que diz respeito ao número de cromossomos e a fórmula cariotípica, com variação do número diploide (2n) de 36 a 74 cromossomos, sendo os rearranjos Robertsonianos (Rb) considerados os principais mecanismos para explicar esta variação cromossômica. Rineloricaria é o gênero mais numeroso de Loricariinae, com espécies apresentando 2n = 36 - 70 cromossomos. Contudo, pouco ainda se sabe sobre quais os tipos de DNAs repetitivos originaram os eventos de fissão e fusão cromossômica. Estudos anteriores revelaram a presença de sítios múltiplos de rDNA 5S em exemplares de Rineloricaria da bacia do Rio Paraná, associados aos eventos de fissão/fusão Robertsonianos. O objetivo deste trabalho foi a caracterização molecular de sítios frágeis associados ao rDNA 5S, além da localização in situ de marcadores cromossômicos em Rineloricaria latirostris do rio das Pedras e R. latirostris do rio Piumhi (pela primeira vez descrito neste trabalho), visando a compreensão da diversificação do 2n neste grupo. Rineloricaria latirostris do rio das Pedras apresentou 2n = 46 cromossomos, enquanto R. latirostris do rio Piumhi apresentou 2n = 48 cromossomos, ambos com número fundamental (NF) de 60. Ensaios de hibridação in situ fluorescente em R. latirostris do rio Piumhi revelaram 2 pares cromossômicos marcados com rDNA 5S, o par 7 marcado com rDNA 18S, além de apenas marcações terminais utilizando-se a sonda telomérica (TTAGGGn). A população do rio das Pedras apresentou 5 pares portadores de sítios de rDNA 5S, o par metacêntrico (m) 2 marcado com rDNA 18S, marcações de TTAGGGn nas regiões terminais dos cromossomos, além da presença de vestígios de sítios teloméricos intersticiais (interstitial telomeric sites - ITS) nos pares m 1 e m 3, sendo este último em sintenia com o rDNA 5S, indicativo de eventos de fusão Robertsoniana. O isolamento, clonagem e sequenciamento de fragmentos de rDNA 5S, revelaram clones apresentando alta identidade ao rDNA 5S de outras espécies, além das regiões necessárias para o reconhecimento e transcrição pela RNA polimerase III. Um dos clones de ~700 pb apresentou um fragmento do transposon hAT em sua sequência, já em intensa degeneração molecular, sendo denominado de rDNA 5S degenerado. A hibridação in situ fluorescente evidenciou cromossomos com marcações co-localizadas de rDNA 5S/hAT, rDNA 5S/rDNA 5S degenerado e rDNA 5S/ITS (no par m 3) em R. latirostris do rio da Pedras. Em R. latirostris do rio Piumhi, não foram detectados sítios com rDNA 5S degenerado. Estes resultados nos permitem inferir o papel do TE hAT na dispersão dos sítios de rDNA 5S na população estudada, visto que alguns estudos indicam haver uma relação entre a dispersão do rDNA 5S pelo genoma e TEs em peixes. Em conclusão, os dados obtidos neste estudo indicam uma possível associação entre o elemento hAT e a dispersão de sítios de rDNA 5S e eventos Robertsonianos presentes na população de R. latirostris estudada. A presença de rDNA 5S/rDNA 5S degenerado/ITS geram hotspots para as quebras cromossômicas, contribuindo assim para a ampla diversidade cariotípica encontrada em Loricariidae.
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Sturmer, Fabiana de C?ssia Romanha. "Caracteriza??o parcial do elemento CCR em Staphylococcus aureus resistentes ? meticilina isolados no sul do Brasil." Pontif?cia Universidade Cat?lica do Rio Grande do Sul, 2008. http://tede2.pucrs.br/tede2/handle/tede/5325.
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Previous issue date: 2008-08-28Os Staphylococcus aureus resistentes ? meticilina (MRSA) encontram-se entre os principais agentes de infec??o hospitalar, para os quais h? grande dificuldade em se obter antimicrobianos para o seu controle. A resist?ncia ? meticilina ? codificada pelo gene mecA, que est? localizado em um elemento gen?tico m?vel denominado staphylococcal cassette chromosome mec (SCCmec). O SCCmec tamb?m possui o complexo g?nico ccr (ccrA e ccrB ou ccrC) e a regi?o J, que cont?m genes que conferem resist?ncia a drogas n?o beta-lact?micas. S?o conhecidos cinco tipos de SCCmec, os tipos I, II e III predominantes em infec??es nosocomiais, enquanto os tipos IV e V s?o, mais comumente, associados a infec??es adquiridas na comunidade. Neste contexto, este estudo se prop?s a realizar a caracteriza??o fenot?pica e genot?pica da resist?ncia ? meticilina de isolados de S. aureus e fenot?pica da resist?ncia ? vancomicina, bem como a determina??o dos subtipos de ccr associados. Para tanto, foram avaliadas 40 amostras de S. aureus obtidas no Servi?o de Microbiologia do Laborat?rio de An?lises Cl?nicas (LABIMED/Hospital de Caridade Astrogildo de Azevedo Santa Maria/RS). A concentra??o inibit?ria m?nima ?s drogas oxacilina e vancomicina foi determinada pelo m?todo de dilui??o em agar. A detec??o de mecA e dos al?tipos de ccr foi realizada atrav?s da rea??o em cadeia da polimerase (PCR). Todos os isolados testados foram considerados resistentes ? oxacilina. Nenhum dos isolados foi classificado como resistente ? vancomicina; no entanto, 25% (10/40) dos isolados apresentaram resist?ncia intermedi?ria ? vancomicina. O gene mecA foi detectado em todos os isolados. O ccrAB1 foi detectado em nove isolados (22,5%) e o ccrAB3 em 23 (57,5%). Oito isolados foram caracterizados como n?o ccrAB1 e n?o ccrAB3. A propor??o de al?tipos ccrAB3, associado a SCCmec tipo III, sugere que o clone epid?mico brasileiro (BEC) tamb?m possa estar presente nos hospitais do Estado do Rio Grande do Sul (Brasil). Considerando que a caracteriza??o do ccr nunca havia sido relatada a partir de isolados desta regi?o do Brasil, este trabalho pode contribuir para o estudo da din?mica do MRSA na Am?rica do Sul.
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Rubin, Paloma Menezes. "Análise do Elemento Transponível copia em Espécies de Drosophila." Universidade Federal de Santa Maria, 2008. http://repositorio.ufsm.br/handle/1/5250.
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Transposable elements (TEs) are segments of DNA that have the ability to move up and replicate themselves within the genome. The retrotransposon copia belongs to the superfamily copia and was first sequenced in D. melanogaster. We used in part of this work, which corresponded to a populational analysis of element
copia in the genomes of species of the group willistoni, the portion of 5'LTR-URL for its importance as a regulatory sequence that can give us relevant phylogenetic
information. Data in silico were added to the work which sought in the twelve genomes of Drosophila available the complete sequence of the element copia and the sequence of LTRs that surround the element. The wide distribution of element copia in the genus Drosophila suggests the occurrence of several cases of horizontal transfer, one of them between D. melanogaster and D. willistoni. To investigate this case we amplify by PCR the region 5'LTR-URL of two strains of D. willistoni, which showed a 95 to 98% similarity with the element copia, but the same homology was not detected in the search made by Southern blot. Some assumptions can be considered to explain these results: the copia polymorphism in the host genome, a
small number of copies in a few individuals of the population or the sequence of the copia element could be in a vector. But the data are still inconclusive. The results of the searches showed a wide distribution of element copia in the genome, despite uneven, and some inconsistencies were found related to the phylogenetic analysis of the host species. Of the species examined, only three of subgenus Sophophora and two of subgenus Drosophila did not show sequences related to copia element.Elementos transponíveis (TEs) são segmentos de DNA que têm a capacidade de mover-se e replicar-se dentro dos genomas. O retrotransposon copia pertence à superfamília copia e foi primeiramente seqüenciado em D. melanogaster. Abordamos em parte deste trabalho uma busca por seqüências relacionadas ao elemento copia nos genomas de diversas linhagens de espécies do grupo willistoni. A região estudada corresponde a porção da 5 LTR-URL, escolhida pela sua importância como seqüência regulatória e que pode nos fornecer informações filogenéticas relevantes. Dados in silico foram adicionados ao trabalho onde buscamos nos doze genomas de Drosophila disponíveis a seqüência completa de copia e a seqüência das LTRs que flanqueiam o elemento. A ampla distribuição do elemento copia no gênero Drosophila sugere indícios da ocorrência de vários casos de transferência horizontal, um deles entre D. melanogaster e D. willistoni. Para investigarmos esse caso amplificamos por PCR a região 5 LTR-URL de duas linhagens de D. willistoni, que apresentaram de 95 a 98% de similaridade com o elemento copia, porém a mesma homologia não foi detectada em rastreamentos por Southern Blot. Algumas hipóteses podem ser levadas em consideração para explicarmos tais resultados: o polimorfismo de copia nos genomas hospedeiros, pequeno número de cópias em poucos indivíduos da população ou a seqüência do elemento copia estar em um vetor. No momento não podemos excluir nenhuma dessas hipóteses. Os resultados das buscas nos genomas seqüenciados mostraram uma ampla distribuição do elemento copia, porém desigual, e algumas incongruências foram encontradas com relação à análise filogenética das espécies hospedeiras. Das espécies analisada em somente três do subgênero Sophophora e duas do subgênero Drosophila não foram encontradas seqüências relacionadas a copia.
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Boughattas, Mohamed Hafedh. "Modélisation par éléments finis des effets des médicaments sur la résistance de l’os." Thesis, Orléans, 2017. http://www.theses.fr/2017ORLE2048/document.
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Le système ostéo-articulaire a un rôle de soutien essentiel pour l’ensemble du corps humain. Il supporte les forces de gravité et les efforts produits par les activités quotidiennes. Ainsi l’os optimise et adapte sa masse et sa géométrie à travers le processus de remodelage osseux. Cette régulation spatio-temporelle peut subir des déséquilibres métaboliques comme l’ostéoporose qui conduisent à la survenue de fracture de l’extrémité supérieure du fémur lors d’une chute latérale ou de traumatismes divers. En effet l’ostéoporose se traduit par une diminution au niveau de la densité osseuse et des détériorations au niveau de la microarchitecture du tissu osseux augmentant ainsi le risque de fractures.Dans le cadre de cette thèse une modélisation mécanique du comportement de l’os ainsi qu’une modélisation biologique des activités cellulaires ont été proposées dans un premier temps. Dans un second temps, la pharmacocinétique de quatre médicaments a été modélisé soient l’Alendronate, le Denosumab,le Romosozumab et l’Odanacatib. Finalement, le couplage de ces modèles a permis d’avoir un modèle mécano-biologique couplé aux effets des médicaments contre l’ostéoporose qui permet de prédire l’évolution de la densité minérale osseuse et celle de l’endommagement par fatigue permettant ainsi d’analyser l’évolution de la qualité osseuse. Ce modèle a été implémenté au code de calcul par éléments finis ABAQUS/standard à travers sa routine utilisateur UMAT. Le modèle a été appliqué pour simuler différents scénarii de remodelage sur des fémurs humains (2D et 3D). Différents facteurs ont été analysés tels que l’amplitude des activités physiques, les doses de médicaments injectées, la durée des traitements, etc. les résultats obtenus sont cohérents (qualitativement) avec les études cliniques existantes. En conclusion, le modèle mécano-biologique couplé aux effets des médicaments proposés contribue à l’analyse fine du comportement de l’os et l’application des algorithmes a permis d’effectuer des essais virtuels permettant d’analyser les effets combinés de nombreux facteurs pluridisciplinaires caractérisant la qualité osseuseThe osteo-articular system plays the role of crucial support for the whole human body. It supports the gravity forces as well as the efforts generated by daily activities. Thus the bone optimizes and adapts its mass and its geometry through the process of bone remodeling. This spatio temporal regulation can undergo metabolic imbalances such as osteoporosis which lead to the occurrence of the upper end of the femur fracture during a fall side or various traumas. In fact, osteoporosis is reflected into a decrease in bone density and level of damage at the level of the microarchitecture of bone tissue increasing therefore the risk of fractures. In the framework of this thesis, a mechanical modelling of the behaviour of the os as well as a biological modelling of cellular activities were firstly proposed. Secondly, the pharmacokinetics of four drugs were modeled which are Alendronate, Denosumab, the Romosozumaband the Odanacatib. Finally, the coupling of these models allowed us to have a mechanic-biological model coupled with the effects of drugs against osteoporosis that can predict the evolution of bone mineral density and of damage by fatigue allowing to analyze the evolution of the bone quality. This model has been implemented by finite elements ABAQUS/standard through its user routine UMAT.The model has been applied to simulate different scenarios of remodeling on human femurs (2D and3D). Different factors were analysed such as the range of physical activities, the doses of injected drugs,the duration of treatment, etc. Obtained results are consistent (qualitatively) with existing clinical studies.As a conclusion, the mechanic-biological model coupled with the effects of the proposed drugs contributes to the fine analysis of the bone behaviour and the application of algorithms allowed to conduct virtual tests in order to analyze the combined effects of many multidisciplinary factors characterizing the bone quality
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Larue, Alyssa. "Analysis of elemental concentrations of biologically important elements in caprine milk and commercial caprine milk replacers using instrumental neutron activation analysis." Connect to resource, 2008. http://hdl.handle.net/1811/32108.
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Ortiz, guzman John Erick. "Fast boundary element formulations for electromagnetic modelling in biological tissues." Thesis, Ecole nationale supérieure Mines-Télécom Atlantique Bretagne Pays de la Loire, 2017. http://www.theses.fr/2017IMTA0051/document.
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Cette thèse présente plusieurs nouvelles techniques pour la convergence rapide des solutions aux éléments de frontière de problèmes électromagnétiques. Une attention spéciale a été dédiée aux formulations pertinentes pour les solutions aux problèmes électromagnétiques dans les tissus biologiques à haute et basse fréquence. Pour les basses fréquences, de nouveaux schémas pour préconditionner et accélérer le problème direct de l'électroencéphalographie sont présentés dans cette thèse. La stratégie de régularisation repose sur une nouvelle formule de Calderon, obtenue dans cette thèse, alors que l'accélération exploite le paradigme d'approximation adaptive croisée (ACA). En ce qui concerne le régime haute fréquence, en vue d'applications de dosimétrie, l'attention de ce travail a été concentrée sur l'étude de la régularisation de l'équation intégrale de Poggio-Miller-Chang-Harrington-Wu-Tsai (PMCHWT) à l'aide de techniques hiérarchiques. Le travail comprend une analyse complète de l'équation pour des géométries simplement et non-simplement connectées. Cela a permis de concevoir une nouvelle stratégie de régularisation avec une base hiérarchique permettant d'obtenir une équation pour les milieux pénétrable stable pour un large spectre de fréquence. Un cadre de travail propédeutique de discrétisation et une bibliothèque de calcul pour des thèmes de recherches sur les techniques de Calderon en 2D sont proposés en dernière partie de cette thèse. Cela permettra d'étendre nos recherches à l'imagerie par tomographieThis thesis presents several new techniques for rapidly converging boundary element solutions of electromagnetic problems. A special focus has been given to formulations that are relevant for electromagnetic solutions in biological tissues both at low and high frequencies. More specifically, as pertains the low-frequency regime, this thesis presents new schemes for preconditioning and accelerating the Forward Problem in Electroencephalography (EEG). The regularization strategy leveraged on a new Calderon formula, obtained in this thesis work, while the acceleration leveraged on an Adaptive-Cross-Approximation paradigm. As pertains the higher frequency regime, with electromagnetic dosimetry applications in mind, the attention of this work focused on the study and regularization of the Poggio-Miller-Chang-Harrington-Wu-Tsai (PMCHWT) integral equation via hierarchical techniques. In this effort, a complete analysis of the equation for both simply and non-simply connected geometries has been obtained. This allowed to design a new hierarchical basis regularization strategy to obtain an equation for penetrable media which is stable in a wide spectrum of frequencies. A final part of this thesis work presents a propaedeutic discretization framework and associated computational library for 2D Calderon research which will enable our future investigations in tomographic imaging
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Cañari, Chumpitaz Cristhian. "Selenium a little known element with an important biological role." Revista de Química, 2013. http://repositorio.pucp.edu.pe/index/handle/123456789/100427.
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El selenio (Se) es un micronutriente esencial presente en diversos organismos incluyendo a los seres humanos. Este elemento puede presentarse en diversas formas metabólicas orgánicas e inorgánicas siendo la más importante la selenocisteína (Sec). La incorporación de Sec en las selenoproteínas emplea un mecanismo único que involucra la recodificación del codón UGA. Este proceso requiere la presencia fragmentos extra en el ARNm como la secuencia de inserción de selenocisteína (SECIS). En la actualidad, la función de muchas selenoproteínas se desconoce, aunque algunas están involucradas en la regulación redox de señales intracelulares, homeostasis redox y el metabolismo de la hormona tiroidea. La deficiencia de selenio afecta a la salud humana y se manifiesta en enfermedades como el cáncer, la enfermedad de Keshan y disfunciones hormonales.Selenium is an essential micronutrient present in various organisms including human beings. This element may be found in different organic and inorganic metabolites, and selenocysteine (Sec) is the most important. The insertion of Sec in selenoproteins uses a unique mechanism that involves the recoding of the UGA codon. This process requires new RNA fragments like the selenocysteine insertion sequence (SECIS) in the mRNA. The function of many selenoproteins is not known completely; however, some of them are involved in intracellular redox signaling regulation, redoxhomeostasis and thyroid hormone metabolism. Se deficiency in humans affects human health and results in diseases such as cancer, Keshan disease and hormonal disfunctions.
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Brisbin, Judith Ann. "EXTRACTION TECHNIQUES FOR TRACE ELEMENT DETERMINATIONS OF BIOLOGICAL AND ENVIRONMENTAL SAMPLES INCLUDING ELEMENTAL SPECIATION OF LOBSTER USING INDUCTIVELY COUPLED PLASMA - MASS SPECTROMETRY." University of Cincinnati / OhioLINK, 2001. http://rave.ohiolink.edu/etdc/view?acc_num=ucin998412111.
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Barbosa, Patrícia. "ELEMENTOS GENÔMICOS REPETITIVOS NO COMPLEXO Astyanax scabripinnis (TELEOSTEI, CHARACIDAE)." UNIVERSIDADE ESTADUAL DE PONTA GROSSA, 2013. http://tede2.uepg.br/jspui/handle/prefix/982.
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Previous issue date: 2013-02-08Coordenação de Aperfeiçoamento de Pessoal de Nível Superior
The most part of the eukaryote genomes is constituted for repetitive DNA or multiple copies DNA, which has already been considered as “junk”, may be associated to the heterochromatin. In this study three Astyanax scabripinnis populations from Pindamonhangaba and Guaratinguetá (SP, Brazil) rivers and stream and one population from Maringá (PR, Brazil) were analyzed about the nucleolar organizing region (NORs), As51 satellite DNA, 18S and 5S rDNA location. Moreover, repetitive sequences were isolated and mapped through Cot-1 technique, which showed homology with UnaL2, a LINE type retrotransposon. The fluorescent in situ hybridization (FISH), with the isolated built retrotransposon probe, evidenced disperse labeled and stronger in centromeric and telomeric chromosomes regions, co-located and interspersed with the 18S DNAr and As51, proven by the fiber-FISH technique. The B chromosome of those populations showed very conspicuous labeled with the LINE probe, also co-located with the As51 sequences. The NORs were actives in a single site of a homologue pair in all three populations, with no evidence that the transposable elements and repetitive DNA have influence in its regulation at the performed analyzes level.
A maior parte do genoma dos eucariotos é constituída por DNA repetitivo ou DNA de múltiplas cópias, o qual já foi considerado “lixo”, podendo estar associado à heterocromatina. Neste estudo foram analisadas três populações de Astyanax scabripinnis provenientes de rios e córregos de Pindamonhangaba e Guaratinguetá (SP, Brasil) e uma população da cidade de Maringá (PR, Brasil) quanto a localização das regiões organizadoras de nucléolo (RONs), DNA satélite As51, DNA ribossomal (DNAr) 18S e DNAr 5S. Ainda, foram isoladas e mapeadas sequências repetitivas por meio da técnica de Cot-1, que mostrou homologia com UnaL2, retrotransposon do tipo LINE. A hibridação in situ fluorescente (FISH), com sonda construída para o retrotransposon isolado, evidenciou marcações dispersas e mais concentradas em regiões centroméricas e teloméricas dos cromossomos, co-localizadas e interespaçadas com DNAr 18S e As51, comprovada pela técnica de fiber-FISH. O cromossomo B das populações mostrou marcações bastante conspícuas com a sonda LINE, também co-localizada com sequências As51. As RONs apresentaram-se ativas em sítios únicos de um par homólogo nas três populações, não havendo indícios de que elementos transponíveis e DNA repetitivo tenham influência na sua regulação ao nível das análises realizadas.
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Easter, Renee N. "The application of elemental tags for biological analyte identification." University of Cincinnati / OhioLINK, 2011. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1307043953.
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Sveinsson, Hrafn Mar. "Constrained Hydrogel swelling in Biological Sensors : A Finite Element Method Approach." Thesis, Norges teknisk-naturvitenskapelige universitet, Institutt for fysikk, 2012. http://urn.kb.se/resolve?urn=urn:nbn:no:ntnu:diva-19103.
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Material models has been developed for anionic and/or cationic hydrogels, with a simulation framework implemented in MATLAB and the finite element software ABAQUS. The geometry of the simulations is a hemispheroidal hydrogel, divided into a core with a shell, covalently attached to an optical fiber. The material models have been used to estimate the chemical parameters of poly-acrylamide hydrogels containing anionic or cationic monomer groups. Simulations comparing free and constrained swelling has been conducted in order to determine the effect of the geometrical constriction to the optical fiber. Constrained hydrogel swelling featuring shells with different properties than the core was also investigated.The aim of the study was to validate the material models and examine the effects of geometrical constrictions together with shell-impregnation. The anionic material model was shown to reproduce experimental swelling data, while the cationic material model only reproduced the data for ionic strength greater than 100 mM. Restricting the hydrogel to an optical fiber resulted in decreased change in volume and an increase in the axial swelling. The model was able to reproduce reported reduction in the swelling for an impregnated anionic hydrogel by using a neutral shell in the simulations, but failed to recreate the shape of the swelling curve. With the reduction of swelling as a basis, a new method for estimating thin-layer properties has been developed.
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Lemaitre, Nolwenn. "Approche multi-proxy (Thorium-234, Baryum en excès) des flux d'export et de reminéralisation du carbone et des éléments nutritifs associés à la pompe biologique océanique." Thesis, Brest, 2017. http://www.theses.fr/2017BRES0009/document.
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L’objectif principal de cette thèse est de mieux comprendre les différents facteurs contrôlant la pompe biologique de carbone en Atlantique Nord et dans l’Océan Austral, à proximité des îles Kerguelen, en utilisant notamment deux approches: le Thorium-234 (234Th) et le baryum biogénique (Baxs).En Atlantique Nord, les flux d’export de carbone organique particulaire (POC) augmentent lorsqu’ils sont associés à des minéraux biogéniques (silice biogénique et carbonate de calcium) et lithogènes, capable de lester les particules. L’efficacité d’export, généralement plus faible que précédemment supposé (< 10%), est inversement corrélée à la production, soulignant un décalage temporel entre production et export. La plus forte efficacité de transfert, i.e. la fraction de POC atteignant 400m, est reliée à des particules lestées par du carbonate de calcium ou des minéraux lithogènes.Les flux de reminéralisation mésopélagique sont similaires ou parfois supérieurs aux flux d’exports et dépendent de l’intensité du développement phytoplanctonique, de la structure en taille, des communautés phytoplanctoniques et des processus physiques (advection verticale).Comme observé pour le POC, l’export des éléments traces est influencé par les particules lithogènes provenant des marges océaniques, mais aussi des différentes espèces phytoplanctoniques.Dans l’Océan Austral, la zone à proximité de l’île de Kerguelen est naturellement fertilisée en fer, augmentant les flux d’export de fer, d’azote et de silice biogénique. Il a été démontré que la variabilité des flux dépendait des communautés phytoplanctoniques dans la zone fertiliséeThe main objective of this thesis is to improve our understanding of the different controls that affect the oceanic biological carbon pump. Particulate export and remineralization fluxes were investigated using the thorium-234 (234Th) and biogenic barium (Baxs) proxies.In the North Atlantic, the highest particulate organic carbon (POC) export fluxes were associated to biogenic (biogenic silica or calcium carbonate) and lithogenic minerals, ballasting the particles.Export efficiency was generally low (< 10%) and inversely related to primary production, highlighting a phase lag between production and export. The highest transfer efficiencies, i.e. the fraction of POC that reached 400m, were driven by sinking particles ballasted by calcite or lithogenic minerals.The regional variation of mesopelagic remineralization was attributed to changes in bloom intensity, phytoplankton cell size, community structure and physical forcing (downwelling). Carbon remineralization balanced, or even exceeded, POC export, highlighting the impact of mesopelagic remineralization on the biological pump with a near-zero, deep carbon sequestration for spring 2014.Export of trace metals appeared strongly influenced by lithogenic material advected from the margins. However, at open ocean stations not influenced by lithogenic matter, trace metal export rather depended on phytoplankton activity and biomass.A last part of this work focused on export of biogenic silica, particulate nitrogen and iron near the Kerguelen Island. This area is characterized by a natural iron-fertilization that increases export fluxes. Inside the fertilized area, flux variability is related to phytoplankton community composition
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Wei, Yu. "Identification and functional characterization of microRNA regulatory elements in Brassicaceae." Doctoral thesis, Università degli studi di Trento, 2016. https://hdl.handle.net/11572/368494.
Full textAbstract:
As a class of short non-coding RNAs, microRNAs can regulate gene expression by a post-transcriptional pathway through repressing or degrading mRNA. In the evolutionary history, many plant microRNAs are highly conserved from green alge to land plants. In recent years, dramatic studies demonstrate that microRNAs play a crucial in plant growth and development, in response to environmental stresses. Some microRNAs can response to plant hormones, while some others are tissue or cell specific. The understanding of how these microRNAs are regulated at the transcriptional level is just initiated. With the aim to understand the regulatory mechanism of plant microRNA in evolutionary tem, and identify the most relevant cisregulatory elements in some microRNAs for improving the agriculture in the future, this study was carried out. microRNA390 is one of the many conserved microRNAs, it can indirectly regulate the ARFs expression level by targeting TAS3, and consequently regulate lateral organ and later root development in plants. In order to understand the regulatory mechanism of microRNAs in an evolutionary term, microRNA390a and microRNA390b in Arabidopsis were chosen and studied. In 16 phylogenetically related species within Brassicaceae, we analyzed the microRNA promoter sequences and identified overall conserved cREs in microRNA390 promoter regions, and accompanied with functional characterization, we obtained a good view of microRNA390 regulatory network. Based on 454 sequencing technique, took the microRNA sequences of sequenced Arabidopsis as reference, by assembling and aligning the microRNA promoter sequences, calculated the PWM and predicted the putative motifs with both MEME program and PlantCARE database, subsequently compared the motif similarities by TOMTOM program, we eventually obtained the putative ones met the required E-value. In the meantime, we reconstructed the phylogenetic trees of both paralogs by MEGA7 program. We identified 6 and 5 overall conserved cREs. Subsequently, we experimentally validated the putative cREs by Arabidopsis transformation and site-specific mutagenesis.
The results we have obtained were as follows:
(1) There were totally 29 microRNA loci in 9 families identified to be highly conserved, and totally 104 putative motifs were predicted in their promoter regions.
(2) The reconstructed phylogenetic trees based on miRNA390a and miRNA390b promoter sequences respectively were compared with the the phylogenetic relationships (species trees) in known Brassicaceae phylogeny. The data derived from both promoter sequences were inconsistent with Brassicaceae phylogeny. This implied that there might be multiple copies of specific cREs in some specific species, hence the promoter sequences evolution of microRNA is not reflective of species phylogeny.
(3) Took Arabidopsis thaliana as model plant, we successfully constructed GUS-fused promoters of miRNA390a and miRNA390b. The GUS histochemical assay indicated that the two paralogs expressed in different tissues in transgenic Arabidopsis. miRNA390a expressed in lateral root primordia, true leaves, cotyledons, as well as in the floral organs, yet it was absent from lateral root tip and shoot apical meristem; whereas miRNA390b specifically expressed on lateral root tips, and a more restricted expression pattern was detected on aerial part of true leaves and floral organ. These differences indicated possible sub-functionalization with respect to their ancestral miR390 during the evolutionary process.
(4) Based on the six putative cREs identified in miRNA390a and the reliable WT constructs, we also constructed six GUS-fused promoters that undergone site-specific mutagenesis. The GUS assay demonstrated that the activity of putative cis-elements varied with distance to TSS. Mutations of proximal sites (m2 and m3) enhanced expression thereby M2 and M3 were likely to be silencers; while mutations of distal elements (m5 and m6) tended to decrease the promoter expression, hence M5 and M6 probably work as enhancers. These evidences suggest there was a specific modular cooperativity of miR390a cREs in regulating gene expression and mediating plant development.
Furthermore, we treated the 7d-old transgenic seedlings with iron-deficiency, both the GUS assay and qRT-PCR data conferred the iron responsiveness of putative iron-deficiency related E-box M3 and the iron-deficiency responsive cis-element 1 M6.
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Albury, Denise. "Selected applications of proton induced X-ray emission to trace element analysis." Thesis, University of Surrey, 1989. http://epubs.surrey.ac.uk/847192/.
Full textAbstract:
The capabilities of the equipment for proton induced X-ray emission analysis at the University of Surrey were examined with particular reference to the trace element analysis of biological samples. The study of samples arising from the Guildford Breast Screening Project was continued. The requirements for trace element analysis of biological samples are outlined together with a review of the available physical analysis techniques. Detail is given of the factors to be considered in order to establish that the study of elemental concentrations by PIXE is feasible. The apparatus used for PIXE analysis is described in detail together with recent improvements to the equipment. The development of a spectrum analysis code HISTO, which simulates the processes of manual analysis, was undertaken. The performance of the code was compared favorably to that of the Ge(Li) spectrum analysis code SAMPO. A preliminary study of 20 samples of human breast cyst fluid was undertaken. The minimum detection limits for those elements assayed by comparative analysis were calculated. The methodology of sample preparation was improved after the examination of target homogeneity and contamination. During a more detailed study of 30 samples the concentration of 9 elements relative to the concetration of potassium was calculated. Calculation of the minimum recommended sample size for elements with Z ≥ 26 indicated that a much larger sample size would be required for reliable results. The PIXE microprobe facility is described and the alignment and operation procedures are outlined. The microprobe was used to examine tree ring samples; examples of some 1D scans are presented. Recommendation that the spectrum analysis code is developed to include a peak location capability is made. Progress with the breast cyst fluid analysis programme is reviewed. The requirement to improve the proton beam current measurment equipment and the data analysis facilities is noted.
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Arshed, Waheed. "The elemental analysis of biological and environmental materials using a 2MeV proton beam." Thesis, University of Surrey, 1991. http://epubs.surrey.ac.uk/843019/.
Full textAbstract:
A summary of the fundamental principles which form the basis of proton induced X-ray emission (PIXE) analysis, proton induced gamma-ray emission (PIGE) analysis, Rutherford backscattering spectrometry (RBS) and instrumental neutron activation analysis (INAA) has been given which is followed by a brief description of the experimental facilities used in this work and their characterization. Knowledge of optimum experimental conditions is always helpful, therefore a programme has been developed to simulate the PIXE spectra and its uses have been described. Reference materials with certified elemental concentrations play an important role in ensuring the accuracy of the elemental analysis work. The FIXE technique has been applied to the analysis of new biological reference materials which consist of IAEA human diet samples and NIST leaf samples, to be introduced in the future. Homogeneity of these and two existing reference materials that is, IAEA soil-7 and Bowen's kale has also been determined at the mug scale. A subsample representative of a material is ascertained by determination of sampling factors for the elements detected in the material. Use of PIXE has been established in experimentally obtaining sampling factors for the above mentioned materials. PIGE analysis in conjunction with PIXE has been employed to investigate F and other elemental concentrations found in human teeth samples. The mean F concentration in enamel and dentine parts of teeth followed an age dependent model. The lowest F concentrations were observed in two out of three careous teeth. Concentrations of Ca and P were found to be higher in the enamel than in the dentine in all the teeth analyzed. Analysis of blood and its components in the study of elemental models in sickle cell disease in Nigerians has been carried out. A total of eight elements were detected. Comparision was made between controls and diseased groups which revealed that Cl, Ca and Cu were at significantly higher levels whereas K, Fe, Zn and Rb were at significantly lower levels in the whole blood of the sicklers as compared to the controls. Similar results were obtained for the erythrocytes except that Br was also found at significantly higher concentration in erythrocytes of the sicklers. Significantly higher concentrations of Cl, K, Fe and Cu were also observed in plasma of the sicklers as compared to that of the controls. Elemental status of the normal controls was found to be comparable to that of the Uzbekistanians (USSR) and North Americans but was better than that of the Bangladeshi population. PIXE and scanning electron microscopy (SEM) was used in the characterization of the Harmattan dust particulates collected at Kano and Ife, two cities of Nigeria. Most of the elements were found to be at higher concentrations as compared to those found in Recife (Brazil) and Toronto (Canada). The value of total suspended particulate matter (TSPM) at both collection sites was also above the relevant national (USA) air quality standards. FIXE in conjunction with RBS and INAA was employed in the analysis of soil samples taken at various depths from within and around two cement factories in Nigeria thereby detecting 31 elements. The results have been discussed with reference to elemental concentrations and Ca/Si ratio. The latter was found to offer a valid indicator of soil pollution by the cement dust.
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AGUIAR, RODRIGO O. de. "Determinacao de elementos em sangue de hamster dourado usando AAN." reponame:Repositório Institucional do IPEN, 2009. http://repositorio.ipen.br:8080/xmlui/handle/123456789/9354.
Full textAbstract:
Made available in DSpace on 2014-10-09T12:26:12Z (GMT). No. of bitstreams: 0Made available in DSpace on 2014-10-09T14:10:39Z (GMT). No. of bitstreams: 0
Dissertacao (Mestrado)
IPEN/D
Instituto de Pesquisas Energeticas e Nucleares - IPEN-CNEN/SP
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Wei, Yu. "Identification and functional characterization of microRNA regulatory elements in Brassicaceae." Doctoral thesis, University of Trento, 2016. http://eprints-phd.biblio.unitn.it/1826/2/declaimer-YuWei.pdf.
Full textAbstract:
As a class of short non-coding RNAs, microRNAs can regulate gene expression by a post-transcriptional pathway through repressing or degrading mRNA. In the evolutionary history, many plant microRNAs are highly conserved from green alge to land plants. In recent years, dramatic studies demonstrate that microRNAs play a crucial in plant growth and development, in response to environmental stresses. Some microRNAs can response to plant hormones, while some others are tissue or cell specific. The understanding of how these microRNAs are regulated at the transcriptional level is just initiated. With the aim to understand the regulatory mechanism of plant microRNA in evolutionary tem, and identify the most relevant cisregulatory elements in some microRNAs for improving the agriculture in the future, this study was carried out. microRNA390 is one of the many conserved microRNAs, it can indirectly regulate the ARFs expression level by targeting TAS3, and consequently regulate lateral organ and later root development in plants. In order to understand the regulatory mechanism of microRNAs in an evolutionary term, microRNA390a and microRNA390b in Arabidopsis were chosen and studied. In 16 phylogenetically related species within Brassicaceae, we analyzed the microRNA promoter sequences and identified overall conserved cREs in microRNA390 promoter regions, and accompanied with functional characterization, we obtained a good view of microRNA390 regulatory network. Based on 454 sequencing technique, took the microRNA sequences of sequenced Arabidopsis as reference, by assembling and aligning the microRNA promoter sequences, calculated the PWM and predicted the putative motifs with both MEME program and PlantCARE database, subsequently compared the motif similarities by TOMTOM program, we eventually obtained the putative ones met the required E-value. In the meantime, we reconstructed the phylogenetic trees of both paralogs by MEGA7 program. We identified 6 and 5 overall conserved cREs. Subsequently, we experimentally validated the putative cREs by Arabidopsis transformation and site-specific mutagenesis.
The results we have obtained were as follows:
(1) There were totally 29 microRNA loci in 9 families identified to be highly conserved, and totally 104 putative motifs were predicted in their promoter regions.
(2) The reconstructed phylogenetic trees based on miRNA390a and miRNA390b promoter sequences respectively were compared with the the phylogenetic relationships (species trees) in known Brassicaceae phylogeny. The data derived from both promoter sequences were inconsistent with Brassicaceae phylogeny. This implied that there might be multiple copies of specific cREs in some specific species, hence the promoter sequences evolution of microRNA is not reflective of species phylogeny.
(3) Took Arabidopsis thaliana as model plant, we successfully constructed GUS-fused promoters of miRNA390a and miRNA390b. The GUS histochemical assay indicated that the two paralogs expressed in different tissues in transgenic Arabidopsis. miRNA390a expressed in lateral root primordia, true leaves, cotyledons, as well as in the floral organs, yet it was absent from lateral root tip and shoot apical meristem; whereas miRNA390b specifically expressed on lateral root tips, and a more restricted expression pattern was detected on aerial part of true leaves and floral organ. These differences indicated possible sub-functionalization with respect to their ancestral miR390 during the evolutionary process.
(4) Based on the six putative cREs identified in miRNA390a and the reliable WT constructs, we also constructed six GUS-fused promoters that undergone site-specific mutagenesis. The GUS assay demonstrated that the activity of putative cis-elements varied with distance to TSS. Mutations of proximal sites (m2 and m3) enhanced expression thereby M2 and M3 were likely to be silencers; while mutations of distal elements (m5 and m6) tended to decrease the promoter expression, hence M5 and M6 probably work as enhancers. These evidences suggest there was a specific modular cooperativity of miR390a cREs in regulating gene expression and mediating plant development.
Furthermore, we treated the 7d-old transgenic seedlings with iron-deficiency, both the GUS assay and qRT-PCR data conferred the iron responsiveness of putative iron-deficiency related E-box M3 and the iron-deficiency responsive cis-element 1 M6.
48
Son, Ahjeong. "Microbial reduction of perchlorate with elemental iron." Access to citation, abstract and download form provided by ProQuest Information and Learning Company; downloadable PDF file 1.83 Mb., 152 p, 2006. http://gateway.proquest.com/openurl?url_ver=Z39.88-2004&res_dat=xri:pqdiss&rft_val_fmt=info:ofi/fmt:kev:mtx:dissertation&rft_dat=xri:pqdiss:3200522.
Full text
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Sharaf, Jamal Mahmood. "Elemental analysis of biological matrices using emission and transmission tomographic techniques." Thesis, University of Surrey, 1994. http://epubs.surrey.ac.uk/844448/.
Full textAbstract:
The main objective of this study has been to investigate the feasibility of using tomographic techniques for non-destructive analysis. A potentially useful technique with neutrons as probes for material characterisation is presented. The technique combines the principles of reconstructive tomography with instrumental neutron activation analysis (INAA) so that elemental distributions in a section through a specimen can be mapped. Neutron induced gamma-ray emission tomography (NIGET) technique, where prompt or delayed gamma-rays can be detected in a tomographic mode, has been developed for samples irradiated in the core of a nuclear reactor and used in studies of different biological matrices. The capabilities of the technique will be illustrated using a spatial resolution of 1 mm. The quantitative usefulness of NIGET depends on the accuracy of compensation for the effect of scattering and attenuation as well as determination of the tomographic system characteristics which contribute to the intrinsic measurement process. It will be shown how quantitative information about the induced radionuclide concentration distribution in a specimen can be obtained when compensation for scattered gamma-rays is taken into account employing a high resolution semiconductor detector and a method of scattering correction based upon the use of three energy windows to collect emission data. For attenuation correction an iterative method which combined emission and transmission measurements has been implemented and its performance was compared to the performance of a number of other attenuation correction algorithms. The work involved investigation into the role of a number of factors which influence the accuracy of data acquisition. An efficiency-resolution figure of merit as a function of collimator efficiency, system resolution and object diameter has been defined. Further, a number of reconstruction techniques were investigated and compared for accuracy, minimum number of projections required and their ability to handle noise. Reconstruction by filtered back projection was fastest to compute, but performed poorly when compared to iterative techniques.
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Gudla, Prabhakar Reddy. "Texture-based segmentation and finite element mesh generation for heterogeneous biological image data." College Park, Md. : University of Maryland, 2005. http://hdl.handle.net/1903/2395.
Full textAbstract:
Thesis (Ph. D.) -- University of Maryland, College Park, 2005.Thesis research directed by: Biological Resources Engineering. Title from t.p. of PDF. Includes bibliographical references. Published by UMI Dissertation Services, Ann Arbor, Mich. Also available in paper.