998 resultados para Contains Zooxanthellae
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In this paper, we investigate whether evidence of discriminatory treatment against immigrants in the Spanish mortgage market exists. More specifically, we test whether, ceteris paribus, immigrant borrowers tend to be charged with higher interest rates on their mortgages than their Spanish born counterparts. To do so, we use a unique dataset on granted mortgages that contains information not only regarding the conditions of the loan but also the socio-economic characteristics of the mortgagors. We observe that immigrants are systematically charged with higher interest rates. We apply the well known Oaxaca-Blinder decomposition to measure the extent to which this disparate treatment of lenders in mortgage pricing against immigrants is due to discrimination. Our results indicate that approximately two thirds of the gap in the interest rate between Spanish born and immigrant borrowers can be attributed to discriminatory treatment. Key words: Immigration, discrimination, mortgage pricing, housing market. JEL codes: R21, G21, J14
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Eosinophils, along with mast cells are key cells involved in the innate immune response against parasitic infection whereas the adaptive immune response is largely dependent on lymphocytes. In chronic parasitic disease and in chronic allergic disease, IL-5 is predominantly a T cell derived cytokine which is particularly important for the terminal differentiation, activation and survival of committed eosinophil precursors. The human IL-5 gene is located on chromosome 5 in a gene cluster that contains the evolutionary related IL-4 family of cytokine genes. The human IL-5 receptor complex is a heterodimer consisting of a unique a subunit (predominantly expressed on eosinophils) and a beta subunit which is shared between the receptors for IL-3 & GM-CSF (more widely expressed). The a subunit is required for ligand-specific binding whereas association with the beta subunit results in increased binding affinity. The alternative splicing of the alphaIL-5R gene which contains 14 exons can yield several alphaIL-5R isoforms including a membrane-anchored isoform (alphaIL-5Rm) and a soluble isoform (alphaIL-5Rs). Cytokines such as IL-5 produce specific and non-specific cellular responses through specific cell membrane receptor mediated activation of intracellular signal transduction pathways which, to a large part, regulate gene expression. The major intracellular signal transduction mechanism is activation of non-receptor associated tyrosine kinases including JAK and MAP kinases which can then transduce signals via a novel family of transcriptional factors named signal transducers and activators of transcription (STATS). JAK2, STAT1 and STAT 5 appear to be particularly important in IL-5 mediated eosinophil responses. Asthma is characterized by episodic airways obstruction, increased bronchial responsiveness, and airway inflammation. Several studies have shown an association between the number of activated T cells and eosinophils in the airways and abnormalities in FEV1, airway reactivity and clinical severity in asthma. It has now been well documented that IL-5 is highly expressed in the bronchial mucosa of atopic and intrinsic asthmatics and that the increased IL-5 mRNA present in airway tissues is predominantly T cell derived. Immunocytochemical staining of bronchial biopsy sections has confirmed that IL-5 mRNA transcripts are translated into protein in asthmatic subjects. Furthermore, the number of activated CD 4 + T cells and IL-5 mRNA positive cells are increased in asthmatic airways following antigen challenge and studies that have examined IL-5 expression in asthmatic subjects before and after steroids have shown significantly decreased expression following oral corticosteroid treatment in steroid-sensitive asthma but not in steroid resistant and chronic severe steroid dependent asthma. The link between T cell derived IL-5 and eosinophil activation in asthmatic airways is further strengthened by the demonstration that there is an increased number of alphaIL-5R mRNA positive cells in the bronchial biopsies of atopic and non-atopic asthmatic subjects and that the eosinophil is the predominant site of this increased alphaIL-5R mRNA expression. We have also shown that the subset of activated eosinophils that expressed mRNA for membrane bound alpha IL5r inversely correlated with FEV1, whereas the subset of activated eosinophils that expressed mRNA for soluble alphaIL5r directly correlated with FEV1. Hence, not only does this data suggest that the presence of eosinophils expressing alphaIL-5R mRNA contribute towards the pathogenesis of bronchial asthma, but also that the eosinophil phenotype with respect to alphaIL-5R isoform expression is of central importance. Finally, there are several animal, and more recently in vitro lung explant, models of allergen induced eosinophilia, late airway responses(LARS), and bronchial hyperresponsiveness(BHR) - all of which support a link between IL-5 and airway eosinophila and bronchial hyperresponsiveness. The most direct demonstration of T cell involvement in LARS is the finding that these physiological responses can be transferred by CD4+ but not CD8+ T cells in rats. The importance of IL-5 in animal models of allergen induced bronchial hyperresponsiveness has been further demonstrated by a number of studies which have indicated that IL-5 administration is able to induce late phase responses and BHR and that anti-IL-5 antibody can block allergen induced late phase responses and BHR. In summary, activated T lymphocytes, IL5 production and eosinophil activation are particularly important in the asthmatic response. Human studies in asthma and studies in allergic animal models have clearly emphasised the unique role of IL-5 in linking T lymphocytes and adaptive immunity, the eosinophil effector cell, and the asthma phenotype. The central role of activated lymphocytes and eosinophils in asthma would argue for the likely therapeutic success of strategies to block T cell and eosinophil activation (eg steroids). Importantly, more targeted therapies may avoid the complications associated with steroids. Such therapies could target key T cell activation proteins and cytokines by various means including blocking antibodies (eg anti-CD4, anti-CD40, anti-IL-5 etc), antisense oligonucleotides to their specific mRNAs, and/or selective inhibition of the promoter sites for these genes. Another option would be to target key eosinophil activation mechanisms including the aIL5r. As always, the risk to benefit ratio of such strategies await the results of well conducted clinical trials.
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Somatic copy number aberrations (CNA) represent a mutation type encountered in the majority of cancer genomes. Here, we present the 2014 edition of arrayMap (http://www.arraymap.org), a publicly accessible collection of pre-processed oncogenomic array data sets and CNA profiles, representing a vast range of human malignancies. Since the initial release, we have enhanced this resource both in content and especially with regard to data mining support. The 2014 release of arrayMap contains more than 64,000 genomic array data sets, representing about 250 tumor diagnoses. Data sets included in arrayMap have been assembled from public repositories as well as additional resources, and integrated by applying custom processing pipelines. Online tools have been upgraded for a more flexible array data visualization, including options for processing user provided, non-public data sets. Data integration has been improved by mapping to multiple editions of the human reference genome, with the majority of the data now being available for the UCSC hg18 as well as GRCh37 versions. The large amount of tumor CNA data in arrayMap can be freely downloaded by users to promote data mining projects, and to explore special events such as chromothripsis-like genome patterns.
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We derive necessary and sufficient conditions under which a set of variables is informationally sufficient, i.e. it contains enough information to estimate the structural shocks with a VAR model. Based on such conditions, we suggest a procedure to test for informational sufficiency. Moreover, we show how to amend the VAR if informational sufficiency is rejected. We apply our procedure to a VAR including TFP, unemployment and per-capita hours worked. We find that the three variables are not informationally sufficient. When adding missing information, the effects of technology shocks change dramatically.
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Cette thèse est construite en quatre parties : trois annexes qui présentent six études de cas (env. 800 pages), précédées par une analyse transversale, plus synthétique (env. 150 pages), dont traite ce résumé. Chaque annexe contient une synthèse détaillée des études de cas. Cette thèse aborde la « gestion des ressources naturelles » en affirmant d'emblée que l'appellation est inappropriée, car ce ne sont pas les ressources qui sont gérées, mais leurs usages. Il s'agit donc d'identifier et d'analyser ce qui influence les comportements humains en lien avec la ressource. Cette affirmation fonde la perspective des sciences sociales sur la gestion des ressources naturelles, dans laquelle s'inscrit cette thèse. L'approche néo-institutionnaliste considère que les usages sont influencés par des institutions, qui sont elles-mêmes influencées par les usagers. Ces institutions sont des constructions humaines qui composent le contexte institutionnel dans lequel les acteurs décident de leurs usages (abattre un arbre, prélever de l'eau, etc.). Les usages des ressources ne sont donc jamais libres et il s'agit de comprendre comment ces règles du jeu influencent les pratiques. Elles sont nombreuses, interdépendantes et forment la trame sur laquelle se décident les usages. Pour saisir cette complexité, l'auteur applique le cadre d'analyse des régimes institutionnels des ressources (RIR) qui se limite à l'analyse de deux types de droits d'usages : ceux issues des règles de la propriété (titres de propriété, servitudes, etc.) et ceux issus des politiques publiques (lois, ordonnances, etc.). Le RIR permet d'identifier un « régime institutionnel », spécifique à la ressource étudiée, dont les évolutions peuvent être comparées dans le temps ou entre plusieurs lieux. Dans cette recherche, ce cadre d'analyse a été appliqué au même objet - la gestion forestière dans les zones de captage d'eau souterraine destinée au réseau public - dans trois pays : en France, en Suisse et en Indonésie. Trois années de recherche de terrain ont permis à l'auteur de s'intéresser non seulement aux règles prédéterminées (la réglementation), mais aussi aux règles effectivement activées sur le terrain (la régulation) par les acteurs rencontrés. Les études de cas montrent que les règles prévues sont inégalement activées et que les acteurs privilégient parfois la négociation directe pour résoudre leurs rivalités d'usages, à la place d'invoquer leurs droits acquis. Ce constat conduit l'auteur à proposer un élargissement de la focale du RIR, qui constitue le coeur de sa thèse. On ne s'intéresse plus seulement à ce qui « est » régulé, mais aussi à ce qui ne l'« est pas » et qui échappe à l'application classique du RIR. Ce renversement de perspective est crucial pour comprendre les usages concrets des ressources dans les régimes peu intégrés, où les pratiques s'expliquent davantage par la marge de manoeuvre laissée aux acteurs que par les règles prédéterminées. Cette relecture, testée avec succès dans cette thèse, permet d'intégrer la marge de manoeuvre à l'analyse au moyen du RIR. Elle se concrétise par l'identification des lacunes et incohérences dans les régimes institutionnels étudiés. Le champ d'application du RIR s'en trouve élargi et sa vulgarisation pour des non-spécialistes est facilitée, notamment pour les environnementalistes. La complémentarité entre les approches s'en trouve renforcée. Les résultats montrent deux choses : premièrement les acteurs disposent toujours d'une marge de manoeuvre pour négocier des régulations ponctuelles, qui sont autant d'alternatives à l'application des règles prévues. Deuxièmement, la conclusion d'accords issus de la négociation bi-/multilatérale dépend directement de la marge de manoeuvre laissée par le contexte institutionnel. Ceci explique pourquoi la négociation entre les propriétaires forestiers et les exploitants de captages s'imposent en Indonésie, est envisageable en France, mais n'aboutit pas en Suisse. Les nombreuses tentatives infructueuses de mise en oeuvre de solutions négociées, notamment sous forme de paiements pour services environnementaux (PSE), trouvent ici une explication. - This thesis (written in French) is built in four parts: three annexes that present six case studies (approx. 800 pages), preceded by a transverse, more conceptual analysis (approx. 150 pages), which this summary is about. Each annexe contains a detailed summary of the case studies. 'Natural resource management' is an inappropriate designation because it is not the resources that are managed but the uses made of them, therefore this thesis addresses the identification and analysis of the influences on human behaviour in relation to the resource. This statement roots the social sciences perspective on the management of natural resources, in which this thesis fits. A neoinstitutionalist approach considers that the uses are influenced by institutions, which are themselves influenced by users. These institutions are human constructions that form the institutional context in which the actors decide on the use of resources (felling a tree, collecting water, etc.). Thus, the uses of resources are never independent from institutional influences and it becomes necessary to understand how these rules of the game affect practices. They are numerous, interrelated and form the basis for the uses of resources. To understand this complexity, the author applies the institutional regime resource framework (IRR) which limits the analysis to two types of use rights: those resulting from the property rights (deeds, easements, etc.) and those from public policies (laws, ordinances, etc.). The IRR identifies an 'institutional regime', specific to the resource, from which developments can be compared over time or between several places. In this research, this analytical framework has been applied to the same topic - forest management in the recharging areas of groundwater piped for public supply - in three countries: France, Switzerland and Indonesia. Three years of field research allow the author to look not only at predetermined rules (rules), but also at regulations that are actually activated on the ground (rules-in-use). The case studies show that the predetermined rules are unevenly applied and that sometimes actors favour direct negotiation to resolve their rivalry of uses, instead of invoking their vested rights. From this observation the author proposes an enlargement of the IRR's scope, forming the core of his thesis. The interest covers not only what 'is' regulated, but what 'is not' and so is beyond the classical application of the IRR. This shift in perspective is crucial to understand the concrete uses of resources in poorly integrated regimes, where practices are explained by the margin of manoeuvre left to the actors rather than predetermined rules. This reinterpretation, tested successfully in this research, allows the margin of manoeuvre to be integrated in the analysis using the IRR and is made concrete by the identification of gaps and inconsistencies in the investigated institutional context. The new interpretation of the IRR in this thesis complements and enhances its classical application. In particular, its use and understanding by non-specialists, especially environmentalists, is facilitated. The results show two things: first the actors always have leeway to negotiate ad hoc regulations, which are alternatives to the application of the predefined rules. Second, the conclusion of bi/multilateral negotiated agreements depends directly on the leeway left by the institutional context. This explains why the negotiation between forest owners and operators of water catchments is needed in Indonesia, is possible in France, but does not succeed in Switzerland. This offers an explanation for many unsuccessful attempts to implement negotiated solutions, notably payments for environmental services (PES).
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This study was performed in order to define Schistosoma mansoni antigens able to function as modulator agents in BALB/c mice granulomatous hypersensitivity to parasite egg. The antigens P-24, P-35 and P-97 were purified by affinity chromatography from a fraction of S. mansoni adult worm antigenic preparation, denominated PIII, involved in the inhibition of granulomatous response to eggs. Immunization of mice with these antigens, in the presence of Corynebacterium parvum and Al(OH)3 as adjuvant, induced a significant protection degree against challenge infection, as observed by the decrease on worm burden recovered from portal system. In vitro blastogenesis assays revealed that purified antigens were able to induce significant proliferation of spleen cells from S. mansoni-infected mice. This protection was correlated to significant decrease in granuloma size induced by PIII. From these results, we concluded that PIII preparation contains antigens capable of mediating protective anti-parasite immunity and down-regulating granulomatous hypersensitivity to S. mansoni eggs.
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ABSTRACT : The retina is one of the most important human sensory tissues since it detects and transmits all visual information from the outside world to the brain. Retinitis pigmentosa (RP) is the name given to a group of inherited diseases that affect specifically the photoreceptors present in the retina and in many instances lead to blindness. Dominant mutations in PRPF31, a gene that encodes for a pre-mRNA splicing factor, cause retinitis pigmentosa with reduced penetrance. We functionally investigated a novel mutation, identified in a large family with autosomal dominant RP, and 7 other mutations, substitutions and microdeletions, in 12 patients from 7 families with PRPF31-linked RP. Seven mutations lead to PRPF31 mRNA with premature stop codons and one to mRNA lacking the exon containing the initiation codon. Quantification of PRPF31 mRNA and protein levels revealed a significant reduction in cell lines derived from patients, compared to non carriers of mutations in PRPF31. Allelic quantification of PRPF31 mRNA indicated that the level of mutated mRNA is very low compared to wild-type mRNA. No mutant protein was detected and the subnuclear localization of wild-type PRPF31 remains the same in cell lines from patients and controls. Blocking nonsense-mediated mRNA decay in cell lines derived from patients partially restored PRPF31 mutated mRNA but derived proteins were still undetectable, even when protein degradation pathways were inhibited. Our results demonstrated that the vast majority of PRPF31 mutations result in null alleles, since they are subject to surveillance mechanisms that degrade mutated mRNA and possibly block its translation. Altogether, these data indicate that the likely cause of PRPF31-linked RP is haploinsufficiency, rather than a dominant negative effect. Penetrance of PRPF31 mutations has been previously demonstrated to be inversely correlated with the level of PRPF31 mRNA, since high expression of wild-type PRPF31 mRNA protects from the disease. Consequently, we have investigated the genetic modifiers that control the expression of PRPF31 by quantifying PRPF31 mRNA levels in cell lines derived from 200 individuals from 15 families representative of the general population. By linkage analyses we identified a 8.2Mb-region on chromosome 14q21-23 that contains a gene involved in the modulation of PRPF31 expression. We also assessed apreviously-mapped penetrance factor invariably located on the wild-type allele and linked to the PRPF31 locus in asymptomatic patients from different families with RP. We demonstrated that this modifier increases the expression of both PRPF31 alleles already at the pre-mRNA level. Finally, our data suggest that PRPF31 mRNA expression and consequently the penetrance of PRPF31 mutations is modulated by at least 2 diffusible compounds, which act on both PRPF31 alleles during their transcription.
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This study describes the morphology of the sperm cell of Maja brachydactyla, with emphasis on localizing actin and tubulin. The spermatozoon of M. brachydactyla is similar in appearance and organization to other brachyuran spermatozoa. The spermatozoon is a globular cell composed of a central acrosome, which is surrounded by a thin layer of cytoplasm and a cup-shaped nucleus with four radiating lateral arms. The acrosome is a subspheroidal vesicle composed of three concentric zones surrounded by a capsule. The acrosome is apically covered by an operculum. The perforatorium penetrates the center of the acrosome and has granular material partially composed of actin. The cytoplasm contains one centriole in the subacrosomal region. A cytoplasmic ring encircles the acrosome in the subapical region of the cell and contains the structures-organelles complex (SO-complex), which is composed of a membrane system, mitochondria with few cristae, and microtubules. In the nucleus, slightly condensed chromatin extends along the lateral arms, in which no microtubules have been observed. Chromatin fibers aggregate in certain areas and are often associated with the SO-complex. During the acrosomal reaction, the acrosome could provide support for the penetration of the sperm nucleus, the SO-complex could serve as an anchor point for chromatin, and the lateral arms could play an important role triggering the acrosomal reaction, while slightly decondensed chromatin may be necessary for the deformation of the nucleus.
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The Digital Memory of Catalonia, Consortium of Academic Libraries of Catalonia, contains open-access digitized collections of photographs, drawings, maps, posters, pamphlets, incunabula, ancient Catalan periodicals and many other items with a total of over two million documents related to Catalonia from 18 different institutions (universities, specialized libraries, institutes, archives, etc.).
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Phylogenetic analysis of all 31 described mitochondrial (cytochrome b) haplotypes of Lutzomyia whitmani demonstrated that new material from the State of Rondônia, in southwest Amazônia, forms a clade within a lineage found only in the rain-forest regions of Brazil. This rain-forest lineage also contains two other clades of haplotypes, one from eastern Amazônia and one from the Atlantic forest zone of northeast Brazil (including the type locality of the species in Ilhéus, State of Bahia). These findings do not favour recognizing two allopatric cryptic species of L. whitmani, one associated with the silvatic transmission of Leishmania shawi in southeast Amazônia and the other with the peridomestic transmission of Le. braziliensis in northeast Brazil. Instead, they suggest that there is (or has been in the recent past) a continuum of inter-breeding populations of L. whitmani in the rain-forest regions of Brazil.
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Summary : The canonical Wnt signaling pathway plays key roles in the maintenance of self-renewing tissues, like the gut or the skin. In contrast, the role of this pathway in hematopoiesis remains poorly defined. Wnt ligands transmit signals through ß-catenin which activates gene transcription upon its association with Lymphoid Cell Enhancer/T Cell Factor (LEF/TCF). Currently, v-catenin is the only alternative factor known to transduce canonical Wnt signals. The ß-/γ-catenin bindiná domain in TCF-1 is required to partly rescue thymopoiesis and NK cell development in TCF-1-deficient mice. However, T cell development and hematopoiesis w-as normal in mice deficient of ß-catenin, or of γ-catenin. Surprisingly we found that hematopoiesis and thymopoiesis was also normal in the combined absence of ß- and γ-catenin. Reporter assays showed that double-deficient lymphocytes were still able to transduce canonical wnt signals. These data provided evidence that hematopoietic cells can transduce canonical Wnt signals in the combined absence of ß- and γ-catenin. There exist numerous TCF-1 isoforrns including those that harbor the N-terminal ß-/y-catenin binding domain or that contains a C-terminal CRARF domain whose role in vivo has not been previously tested. We found that the CRARF domain influences lymphocyte development in conjunction with the N-treminal ß-/γ-catenin binding. The presence of the two domains directs thymocytes to the CD8+ T cell lineage whereas NK cell development is abolished. Roles of the canonical Wnt/TCF-1 pathway for lymphocyte function have not been defined. We demonstrate that TCF-1 deficient CDBT T cells mount a normal primary response to viral infection but these T cells fail to expand upon restimulation. The failure of CD8+ T cells to respond to IL-2 during primary infection seems to account for this phenotype. Thus, TCF-1 is essential for programming functional CD8+ T cell memory. Collectively, these data provide significant new insights into the role of Wnt/TCF-1 pathway for lymphocyte development and function and suggest a novel mechanism of Wnt signal transuction in hematopoietic cells. Résumé : La voie de signalisation canonique Wnt joue un rôle prépondérant dans le renouvellement de tissus, comme l'intestin ou la peau. Son rôle dans l'hématopoïèse est quant à lui mal défini. Le ligand Wnt transmet le signal via la ß-catenin qui active la transcription de gènes cibles quand il est associé avec Lymphoid Cell Enhancer,~T Cell Factor (LEF/TCF). Actuellement, la γ-catenin est le seul autre facteur connu pouvant se substituer à la fonction de la ß-catenin. Un variant de TCF-1 contenant le domaine liant ß-/,~-catenin est capable de restaurer le développement des lymphocytes T et NK en l'absence de TCF-1. Cependant la thymopoïèse et l'hématopoïèse sont normales dans les souris déficientes pour la ß-catenin ou la γ-catenin. De façon surprenante, nous avons trouvé que l'hématopoïèse et le développement des lymphocytes sont normaux lors de l'absence combinée de ß-/γ-catenin. De plus, la transduction des signaux de la voie de signalisation Wnt est maintenue dans des lymphocytes déficients pour ß-/γ-catenin. Ces résultats démontrent que les cellules hématopoïétiques peuvent transmettre les signaux de la voie canonique Wnt lors de l'absence combinée de la ß et la γ -catenin. Il existe de nombreuses isofonnes de TCF-1, y compris certaines qui comprennent un domaine qui lie ß-/γ-catenin du côté N-terminus ou qui contiennent un domaine CRARF du côté C-terminus. Nous montrons ici que le domaine CRARF influence le développement des lymphocytes en conjonction avec le domaine liant ß-/γ-catenin. La présence des deux domaines dirige les thymocytes vers la lignée de cellules T CD8, alors que le développement des cellules NK est aboli. Au-delà de sa fonction sur le développement des lymphocytes, le rôle de la soie de signalisation canonique Wnt/TCF-1 lors d'une infection n'a pas été défini. Nous avons montré que les cellules T CD8, déficientes pour TCF-1, développent une réponse primaire normale à une infection virale, mais qu'elles ne s'accumulent pas après restimulation. L'incapacité des cellules TCD8 à répondre à l'IL-2 durant la réponse primaire peut expliquer ce phénotype. Ainsi; TCF-1 est essentiel pour la programmation de cellules T CD8 mémoires fonctionnelles. L'ensemble de ces résultats fournit de nouveaux aperçus du rôle de la voie de signalisation Wnt/TCF-1 pour le développement et la fonction des lymphocytes et suggèrent un nouveau mécanisme de transduction du signal Wnt dans les cellules hématopoïétiques.
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Recently, the introduction of second generation sequencing and further advance-ments in confocal microscopy have enabled system-level studies for the functional characterization of genes. The degree of complexity intrinsic to these approaches needs the development of bioinformatics methodologies and computational models for extracting meaningful biological knowledge from the enormous amount of experi¬mental data which is continuously generated. This PhD thesis presents several novel bioinformatics methods and computational models to address specific biological questions in Plant Biology by using the plant Arabidopsis thaliana as a model system. First, a spatio-temporal qualitative analysis of quantitative transcript and protein profiles is applied to show the role of the BREVIS RADIX (BRX) protein in the auxin- cytokinin crosstalk for root meristem growth. Core of this PhD work is the functional characterization of the interplay between the BRX protein and the plant hormone auxin in the root meristem by using a computational model based on experimental evidence. Hyphotesis generated by the modelled to the discovery of a differential endocytosis pattern in the root meristem that splits the auxin transcriptional response via the plasma membrane to nucleus partitioning of BRX. This positional information system creates an auxin transcriptional pattern that deviates from the canonical auxin response and is necessary to sustain the expression of a subset of BRX-dependent auxin-responsive genes to drive root meristem growth. In the second part of this PhD thesis, we characterized the genome-wide impact of large scale deletions on four divergent Arabidopsis natural strains, through the integration of Ultra-High Throughput Sequencing data with data from genomic hybridizations on tiling arrays. Analysis of the identified deletions revealed a considerable portion of protein coding genes affected and supported a history of genomic rearrangements shaped by evolution. In the last part of the thesis, we showed that VIP3 gene in Arabidopsis has an evo-lutionary conserved role in the 3' to 5' mRNA degradation machinery, by applying a novel approach for the analysis of mRNA-Seq data from random-primed mRNA. Altogether, this PhD research contains major advancements in the study of natural genomic variation in plants and in the application of computational morphodynamics models for the functional characterization of biological pathways essential for the plant. - Récemment, l'introduction du séquençage de seconde génération et les avancées dans la microscopie confocale ont permis des études à l'échelle des différents systèmes cellulaires pour la caractérisation fonctionnelle de gènes. Le degrés de complexité intrinsèque à ces approches ont requis le développement de méthodologies bioinformatiques et de modèles mathématiques afin d'extraire de la masse de données expérimentale générée, des information biologiques significatives. Ce doctorat présente à la fois des méthodes bioinformatiques originales et des modèles mathématiques pour répondre à certaines questions spécifiques de Biologie Végétale en utilisant la plante Arabidopsis thaliana comme modèle. Premièrement, une analyse qualitative spatio-temporelle de profiles quantitatifs de transcripts et de protéines est utilisée pour montrer le rôle de la protéine BREVIS RADIX (BRX) dans le dialogue entre l'auxine et les cytokinines, des phytohormones, dans la croissance du méristème racinaire. Le noyau de ce travail de thèse est la caractérisation fonctionnelle de l'interaction entre la protéine BRX et la phytohormone auxine dans le méristème de la racine en utilisant des modèles informatiques basés sur des preuves expérimentales. Les hypothèses produites par le modèle ont mené à la découverte d'un schéma différentiel d'endocytose dans le méristème racinaire qui divise la réponse transcriptionnelle à l'auxine par le partitionnement de BRX de la membrane plasmique au noyau de la cellule. Cette information positionnelle crée une réponse transcriptionnelle à l'auxine qui dévie de la réponse canonique à l'auxine et est nécessaire pour soutenir l'expression d'un sous ensemble de gènes répondant à l'auxine et dépendant de BRX pour conduire la croissance du méristème. Dans la seconde partie de cette thèse de doctorat, nous avons caractérisé l'impact sur l'ensemble du génome des délétions à grande échelle sur quatre souches divergentes naturelles d'Arabidopsis, à travers l'intégration du séquençage à ultra-haut-débit avec l'hybridation génomique sur puces ADN. L'analyse des délétions identifiées a révélé qu'une proportion considérable de gènes codant était affectée, supportant l'idée d'un historique de réarrangement génomique modelé durant l'évolution. Dans la dernière partie de cette thèse, nous avons montré que le gène VÏP3 dans Arabidopsis a conservé un rôle évolutif dans la machinerie de dégradation des ARNm dans le sens 3' à 5', en appliquant une nouvelle approche pour l'analyse des données de séquençage d'ARNm issue de transcripts amplifiés aléatoirement. Dans son ensemble, cette recherche de doctorat contient des avancées majeures dans l'étude des variations génomiques naturelles des plantes et dans l'application de modèles morphodynamiques informatiques pour la caractérisation de réseaux biologiques essentiels à la plante. - Le développement des plantes est écrit dans leurs codes génétiques. Pour comprendre comment les plantes sont capables de s'adapter aux changements environnementaux, il est essentiel d'étudier comment leurs gènes gouvernent leur formation. Plus nous essayons de comprendre le fonctionnement d'une plante, plus nous réalisons la complexité des mécanismes biologiques, à tel point que l'utilisation d'outils et de modèles mathématiques devient indispensable. Dans ce travail, avec l'utilisation de la plante modèle Arabidopsis thalicinci nous avons résolu des problèmes biologiques spécifiques à travers le développement et l'application de méthodes informatiques concrètes. Dans un premier temps, nous avons investigué comment le gène BREVIS RADIX (BRX) régule le développement de la racine en contrôlant la réponse à deux hormones : l'auxine et la cytokinine. Nous avons employé une analyse statistique sur des mesures quantitatives de transcripts et de produits de gènes afin de démontrer que BRX joue un rôle antagonisant dans le dialogue entre ces deux hormones. Lorsque ce-dialogue moléculaire est perturbé, la racine primaire voit sa longueur dramatiquement réduite. Pour comprendre comment BRX répond à l'auxine, nous avons développé un modèle informatique basé sur des résultats expérimentaux. Les simulations successives ont mené à la découverte d'un signal positionnel qui contrôle la réponse de la racine à l'auxine par la régulation du mouvement intracellulaire de BRX. Dans la seconde partie de cette thèse, nous avons analysé le génome entier de quatre souches naturelles d'Arabidopsis et nous avons trouvé qu'une grande partie de leurs gènes étaient manquant par rapport à la souche de référence. Ce résultat indique que l'historique des modifications génomiques conduites par l'évolution détermine une disponibilité différentielle des gènes fonctionnels dans ces plantes. Dans la dernière partie de ce travail, nous avons analysé les données du transcriptome de la plante où le gène VIP3 était non fonctionnel. Ceci nous a permis de découvrir le rôle double de VIP3 dans la régulation de l'initiation de la transcription et dans la dégradation des transcripts. Ce rôle double n'avait jusqu'alors été démontrée que chez l'homme. Ce travail de doctorat supporte le développement et l'application de méthodologies informatiques comme outils inestimables pour résoudre la complexité des problèmes biologiques dans la recherche végétale. L'intégration de la biologie végétale et l'informatique est devenue de plus en plus importante pour l'avancée de nos connaissances sur le fonctionnement et le développement des plantes.
Resumo:
Purpose: Mutations in the ligand-binding domain (LBD) of NR2E3 cause recessively inherited enhanced short wavelength sensitive (S-) cone syndrome (ESCS), Goldmann-Favre syndrome (GFS) and clumped pigmentary retinal degeneration (CPRD). In addition to ligand binding, the LBD contains also essential amino acid sequences for the oligomerization of nuclear receptors. The aim of our studies is to characterize the impact of mutations in the LBD on receptor oligomerization and transcriptional activity of NR2E3. Methods: The different NR2E3 mutants were generated by QuickChange mutagenesis and analyzed in 293T-based transactivation studies and BRET2 (bioluminescence resonance electron transfer) assays. In silico homology modeling of mutant proteins was also performed using available crystallographic data of related nuclear receptors. Results: The mutants p.W234S, p.A256V, p.A256E, p.L263P, p.R309G, p.R311Q, p.R334G, p.L336P, p.L353V, p.R385P and p.M407K, all located in the LBD, showed impaired receptor dimerization at various degrees. Impaired repressor dimerization as assessed by BRET2 assays did not always correlate with impaired repressor function of NR2E3 as assessed by cell-based reporter assays. There were minor differences of transcriptional activity of mutant proteins on mouse S-opsin (opn1sw), mouse cone arrestin (arr3) and human cone arrestin, suggesting that the effect of LBD mutations was independent of the promoter context. Conclusions: Mutational analysis and homology modeling allowed the characterization of potential oligomerization interfaces of the NR2E3 LBD. Additionally, mutations in NR2E3 LBD may cause recessive retinal degenerations by different molecular mechanisms.
Resumo:
L’augment del nombre de persones estrangeres que s’ha produït al llarg dels darrers anys va comportar que l’any 2008 la Direcció General de Recursos i Règim Penitenciari (DGRRP a partir d’ara) plantegés al Centre d’Estudis Jurídics i Formació Especialitzada la necessitat de conèixer més en profunditat aquesta població i les seves característiques i necessitats específiques. Diversos interrogants concrets formaven part d’aquella demanda inicial i van quedar explícitament recollits en els objectius de la recerca que presentarem tot seguit. Un tema destacat va ser des del principi la constatació de les dificultats d’integració social de les persones estrangeres empresonades un cop acomplerta la pena, en el marc del complex context legal que regula l’estrangeria al nostre país. La finalitat d’aquesta recerca és donar un coneixement ampli i global de la realitat dels estrangers als centres penitenciaris catalans i de les seves possibilitats de futur, apuntant recomanacions que puguin ajudar la DGRRP a intervenir amb més eficàcia en aquest tema de gran actualitat i complexitat.
Resumo:
El estudio recoge los perfiles de los extranjeros que se encuentran en las prisiones catalanas, cual ha sido su trayectoria migratoria hasta el momento actual, qué expectativas tienen respecto a su futuro, así como sus opiniones en relación a su situación en prisión y el trato que recibe por parte de las autoridades penitenciarias. También se analiza pormenorizadamente su situación administrativa y de regularización. El estudio termina con 29 recomendaciones para la mejora de todos los ámbitos de la intervención penitenciaria.