77 resultados para Regimes previdenciários


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Aleppo pine (Pinus halepensis Mill.) is a relevant conifer species for studying adaptive responses to drought and fire regimes in the Mediterranean region. In this study, we performed Illumina next-generation sequencing of two phenotypically divergent Aleppo pine accessions with the aims of (i) characterizing the transcriptome through Illumina RNA-Seq on trees phenotypically divergent for adaptive traits linked to fire adaptation and drought, (ii) performing a functional annotation of the assembled transcriptome, (iii) identifying genes with accelerated evolutionary rates, (iv) studying the expression levels of the annotated genes and (v) developing gene-based markers for population genomic and association genetic studies. The assembled transcriptome consisted of 48,629 contigs and covered about 54.6 Mbp. The comparison of Aleppo pine transcripts to Picea sitchensis protein-coding sequences resulted in the detection of 34,014 SNPs across species, with a Ka /Ks average value of 0.216, suggesting that the majority of the assembled genes are under negative selection. Several genes were differentially expressed across the two pine accessions with contrasted phenotypes, including a glutathione-s-transferase, a cellulose synthase and a cobra-like protein. A large number of new markers (3334 amplifiable SSRs and 28,236 SNPs) have been identified which should facilitate future population genomics and association genetics in this species. A 384-SNP Oligo Pool Assay for genotyping with the Illumina VeraCode technology has been designed which showed an high overall SNP conversion rate (76.6%). Our results showed that Illumina next-generation sequencing is a valuable technology to obtain an extensive overview on whole transcriptomes of nonmodel species with large genomes.

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1. Dietary conditions affect cognitive abilities of many species, but it is unclear to what extent this physiological effect translates into an evolutionary relationship. 2. A reduction of competitive ability under nutritional stress has been reported as a correlated response to selection for learning ability in Drosophila melanogaster. Here we test whether the reverse holds as well, i.e. whether an evolutionary adaptation to poor food conditions leads to a decrease in learning capacities. 3. Populations of D. melanogaster were: (i) not subject to selection (control), (ii) selected for improved learning ability, (iii) selected for survival and fast development on poor food, or (iv) subject to both selection regimes. 4. There was no detectable response to selection for learning ability. 5. Selection on poor food led to higher survival, faster development and smaller adult size as a direct response, and to reduced learning ability as a correlated response. This study supports the hypothesis that adaptation to poor nutrition is likely to trade off with the evolution of improved learning ability.

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Spatial variation in the pattern of natural selection can promote local adaptation and genetic differentiation between populations. Because heritable melanin-based ornaments can signal resistance to environmentally mediated elevation in glucocorticoids, to oxidative stress and parasites, populations may vary in the mean degree of melanic coloration if selection on these phenotypic aspects varies geographically. Within a population of Swiss barn owls (Tyto alba), the size of eumelanic spots is positively associated with survival, immunity and resistance to stress, but it is yet unknown whether Tyto species that face stressful environments evolved towards a darker eumelanic plumage. Because selection regimes vary along environmental gradients, we examined whether melanin-based traits vary clinally and are expressed to a larger extent in the tropics where parasites are more abundant than in temperate zones. To this end, we considered 39 barn owl species distributed worldwide. Barn owl species living in the tropics displayed larger eumelanic spots than those found in temperate zones. This was, however, verified in the northern hemisphere only. Parasites being particularly abundant in the tropics, they may promote the evolution of darker eumelanic ornaments.

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Salmonid populations of many rivers are rapidly declining. One possible explanation is that habitat fragmentation increases genetic drift and reduces the populations' potential to adapt to changing environmental conditions. We measured the genetic and eco-morphological diversity of brown trout (Salmo trutta) in a Swiss stream system, using multivariate statistics and Bayesian clustering. We found large genetic and phenotypic variation within only 40 km of stream length. Eighty-eight percent of all pairwise F(ST) comparisons and 50% of the population comparisons in body shape were significant. High success rates of population assignment tests confirmed the distinctiveness of populations in both genotype and phenotype. Spatial analysis revealed that divergence increased with waterway distance, the number of weirs, and stretches of poor habitat between sampling locations, but effects of isolation-by-distance and habitat fragmentation could not be fully disentangled. Stocking intensity varied between streams but did not appear to erode genetic diversity within populations. A lack of association between phenotypic and genetic divergence points to a role of local adaptation or phenotypically plastic responses to habitat heterogeneity. Indeed, body shape could be largely explained by topographic stream slope, and variation in overall phenotype matched the flow regimes of the respective habitats.

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Mountains and mountain societies provide a wide range of goods and services to humanity, but they are particularly sensitive to the effects of global environmental change. Thus, the definition of appropriate management regimes that maintain the multiple functions of mountain regions in a time of greatly changing climatic, economic, and societal drivers constitutes a significant challenge. Management decisions must be based on a sound understanding of the future dynamics of these systems. The present article reviews the elements required for an integrated effort to project the impacts of global change on mountain regions, and recommends tools that can be used at 3 scientific levels (essential, improved, and optimum). The proposed strategy is evaluated with respect to UNESCO's network of Mountain Biosphere Reserves (MBRs), with the intention of implementing it in other mountain regions as well. First, methods for generating scenarios of key drivers of global change are reviewed, including land use/land cover and climate change. This is followed by a brief review of the models available for projecting the impacts of these scenarios on (1) cryospheric systems, (2) ecosystem structure and diversity, and (3) ecosystem functions such as carbon and water relations. Finally, the cross-cutting role of remote sensing techniques is evaluated with respect to both monitoring and modeling efforts. We conclude that a broad range of techniques is available for both scenario generation and impact assessments, many of which can be implemented without much capacity building across many or even most MBRs. However, to foster implementation of the proposed strategy, further efforts are required to establish partnerships between scientists and resource managers in mountain areas.

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This review paper reports the consensus of a technical workshop hosted by the European network, NanoImpactNet (NIN). The workshop aimed to review the collective experience of working at the bench with manufactured nanomaterials (MNMs), and to recommend modifications to existing experimental methods and OECD protocols. Current procedures for cleaning glassware are appropriate for most MNMs, although interference with electrodes may occur. Maintaining exposure is more difficult with MNMs compared to conventional chemicals. A metal salt control is recommended for experiments with metallic MNMs that may release free metal ions. Dispersing agents should be avoided, but if they must be used, then natural or synthetic dispersing agents are possible, and dispersion controls essential. Time constraints and technology gaps indicate that full characterisation of test media during ecotoxicity tests is currently not practical. Details of electron microscopy, dark-field microscopy, a range of spectroscopic methods (EDX, XRD, XANES, EXAFS), light scattering techniques (DLS, SLS) and chromatography are discussed. The development of user-friendly software to predict particle behaviour in test media according to DLVO theory is in progress, and simple optical methods are available to estimate the settling behaviour of suspensions during experiments. However, for soil matrices such simple approaches may not be applicable. Alternatively, a Critical Body Residue approach may be taken in which body concentrations in organisms are related to effects, and toxicity thresholds derived. For microbial assays, the cell wall is a formidable barrier to MNMs and end points that rely on the test substance penetrating the cell may be insensitive. Instead assays based on the cell envelope should be developed for MNMs. In algal growth tests, the abiotic factors that promote particle aggregation in the media (e.g. ionic strength) are also important in providing nutrients, and manipulation of the media to control the dispersion may also inhibit growth. Controls to quantify shading effects, and precise details of lighting regimes, shaking or mixing should be reported in algal tests. Photosynthesis may be more sensitive than traditional growth end points for algae and plants. Tests with invertebrates should consider non-chemical toxicity from particle adherence to the organisms. The use of semi-static exposure methods with fish can reduce the logistical issues of waste water disposal and facilitate aspects of animal husbandry relevant to MMNs. There are concerns that the existing bioaccumulation tests are conceptually flawed for MNMs and that new test(s) are required. In vitro testing strategies, as exemplified by genotoxicity assays, can be modified for MNMs, but the risk of false negatives in some assays is highlighted. In conclusion, most protocols will require some modifications and recommendations are made to aid the researcher at the bench. [Authors]

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We study optimal public rationing of an indivisible good and private sector price responses. Consumers differ in their wealth and costs of provisions. Due to a limited budget, some consumers must be rationed. Public rationing determines the characteristics of consumers who seek supply from the private sector, where a firm sets prices based on consumers' cost information and in response to the rationing rule. We consider two information regimes. In the first, the public supplier rations consumers according to their wealth information. In equilibrium, the public supplier must ration both rich and poor consumers. Supplying all poor consumers would leave only rich consumers in the private market, and the firm would react by setting a high price. Rationing some poor consumers is optimal, and implements price reduction in the private market. In the second information regime, the public supplier rations consumers according to consumers' wealth and cost information. In equilibrium, consumers are allocated the good if and only if their costs are below a threshold. Wealth information is not used. Rationing based on cost results in higher equilibrium total consumer surplus than rationing based on wealth. [Authors]

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Transcriptome analysis is a powerful tool for unveiling the distribution and magnitude of genetic incompatibilities between hybridizing taxa. The nature of such incompatibilities is closely associated with the evolutionary histories of the parental species and may differ across tissues and between the sexes. In eusocial insects, the presence of castes that experience divergent selection regimes may result in additional distinct patterns of caste-specific hybrid incompatibilities. We analysed levels of expression of >14 000 genes in two life stages of each caste in the fire ants Solenopsis invicta and Solenopsis richteri and in their hybrids. We found strong contributions of both developmental stage and caste to gene expression patterns. In contrast, variability in expression was only weakly associated with taxonomic identity, with hybrid scores falling between those of the two parental species. Hybrid incompatibilities were surprisingly modest, with only 32 genes being mis-expressed, indicating low levels of disruption in gene regulation in hybrids; males and workers each mis-expressed at least seven times as many genes as queens. Interestingly, homologues of many of the mis-expressed genes have been implicated in behavioural variation in Drosophila melanogaster. General expression profiles of hybrids consistently were more similar to those of S. richteri than S. invicta, presumably because S. richteri trans-regulatory elements tend to be dominant and/or because there is an overall bias in the genetic composition of the hybrids towards S. richteri. Altogether, our results suggest that selection acting on each caste may contribute differently to interspecific divergence and speciation in this group of ants.

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Les Pays-Bas et la Suisse sont souvent décrits comme ayant des relations entre travail et capital similaires, marquées par des négociations et le compromis. La conviction est courante dans les deux pays qu'il y a une tendance constante au consensus et au compromis dans l'histoire nationale. Cette thèse livre une comparaison historique du développement des relations de classe dans la 1ers moitié du 20eme siècle. Une attention particulière est donnée aux confrontations sévères et partiellement violentes entre les classes qui ont eu lieu pendant et juste après la Première Guerre Mondiale. Dans la crise des années trente, les deux pays ont longtemps maintenu l'attachement à une politique de déflation, ce qui a mené à une nouvelle accentuation des tensions sociales. Dans ce contexte, loin d'être prêts à faire des concessions au mouvement ouvrier, d'importantes composantes du patronat néerlandais et suisse sympathisaient avec un corporatisme autoritaire comme il était prôné par les mouvements et régimes fascistes. Des alliances entre le mouvement ouvrier socialiste et des fractions importantes des classes moyennes étaient capables d'arrêter cette dérive autoritaire, sans avoir assez de force pour imposer leurs propres alternatives. C'est seulement après l'affaiblissement de la droite dure entre la deuxième moitié des années trente et l'immédiat après-guerre que des premiers fondements pour un compromis de classe stable ont été établis. Généralement, l'approche comparée de la thèse permet de mieux saisir les histoires nationales dans leur contexte européen et global et permet donc de dépasser une vue de l'histoire nationale comme «cas spécial».¦Die Beziehungen zwischen Arbeit und Kapital in Niederlande und die Schweiz werden oft als âhnlich und stark von Verhandlungen und von Kompromissen geprâgt beschrieben. In beiden Lândern ist die Auffassung weitverbreitet, dass es in der nationalen Geschichte eine konstante Tendenz zum Konsens und zum Kompromiss gebe. Diese Dissertation bietet einen historischen Vergleich der Entwicklung der Klassenbeziehungen in der ersten Hâlfte des 20. Jahrhunderts. Thematisiert werden insbesondere die ernsthaften und teilweise gewalttàtigen Zusammenstôsse zwischen den Klassen, die sich wàhrend und unmittelbar nach dem Ersten Weltkrieg ereigneten. In der Krise der Dreissigerjahre hielten beide Staaten lange an der Deflationspolitik fest, was erneut zu einer Verschârfung der sozialen Spannungen fïïhrte. Vor diesem Hintergrund lehnten weite Teile der schweizerischen und niederlândischen Grossunternehmer Konzessionen gegenuber der Arbeiterbewegung ab. Vielmehr sympathisierten sie mit einem autoritàren Korporatismus, wie er von den faschistischen Bewegungen und Regimes vertreten wurde. Allianzen zwischen der sozialistischen Arbeiterbewegung und Teilen der Mittelschichten gelang es zwar, diese autoritàren Tendenzen aufzuhalten, nicht aber ihre eigenen Alteraativkonzepte durchzusetzen. Erst nach der Schwâchung der radikalen Rechten in der Zeit zwischen der zweiten Hàlfte der 1930er Jahre und der unmittelbaren Nachkriegszeit nach dem Zweiten Weltkrieg fand sich eine¦Grundlage fur einen stabilen Klassenkompromiss. Generell ermôglicht es der vergleichende Ansatz der Dissertation, die nationale Geschichte in ihrem europâischen und globalen Kontext zu sehen und so eine Sicht auf die Geschichte eines einzelnen Landes als ,,Sonderfall" zu uberwinden.

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Host-pathogen interactions are a major evolutionary force promoting local adaptation. Genes of the major histocompatibility complex (MHC) represent unique candidates to investigate evolutionary processes driving local adaptation to parasite communities. The present study aimed at identifying the relative roles of neutral and adaptive processes driving the evolution of MHC class IIB (MHCIIB) genes in natural populations of European minnows (Phoxinus phoxinus). To this end, we isolated and genotyped exon 2 of two MHCIIB gene duplicates (DAB1 and DAB3) and 1665 amplified fragment length polymorphism (AFLP) markers in nine populations, and characterized local bacterial communities by 16S rDNA barcoding using 454 amplicon sequencing. Both MHCIIB loci exhibited signs of historical balancing selection. Whereas genetic differentiation exceeded that of neutral markers at both loci, the populations' genetic diversities were positively correlated with local pathogen diversities only at DAB3. Overall, our results suggest pathogen-mediated local adaptation in European minnows at both MHCIIB loci. While at DAB1 selection appears to favor different alleles among populations, this is only partially the case in DAB3, which appears to be locally adapted to pathogen communities in terms of genetic diversity. These results provide new insights into the importance of host-pathogen interactions in driving local adaptation in the European minnow, and highlight that the importance of adaptive processes driving MHCIIB gene evolution may differ among duplicates within species, presumably as a consequence of alternative selective regimes or different genomic context.

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Résumé en français La thèse de doctorat porte, de manière générale, sur le rôle des acteurs administratifs dans la mise en oeuvre de l'action publique. En particulier, dans le contexte de l'implémentation de la politique suisse d'assurance-chômage, la recherche se focalise sur l'étude de la bureaucratie de guichet, à savoir un type spécifique d'administrations et d'agents publics situés aux premières lignes de l'action étatique et qui sont en contact direct et quotidien avec les usagers. La thèse a pour objectif principal d'obtenir une compréhension détaillée des impacts concrets dont sont porteurs deux types de réformes majeures du secteur public : les réformes de Nouvelle Gestion Publique (NGP) et les nouvelles technologies informatiques. Le questionnement central de la recherche consiste en une étude approfondie des effets de ces réformes sur les bureaucraties de guichet, et en particulier sur deux aspects centraux les concernant : d'une part, le niveau de pouvoir discrétionnaire que les agents publics de base disposent dans l'application de la loi fédérale sur l'assurance-chômage, autrement dit leur marge de manoeuvre ; d'autre part, les manières au travers desquelles ces mêmes agents sont appelés à rendre des comptes quant à leurs actions et leurs décisions, à savoir l'enjeu plus large de la redevabilité publique des acteurs administratifs. Ces enjeux ont été analysés au niveau empirique dans le contexte organisationnel d'une caisse publique cantonale de chômage ayant expérimenté les réformes évoquées ci-dessus. L'organisation choisie a été investiguée au travers d'une étude de cas ethnographique approfondie (observation directe du travail quotidien des agents, entretiens semi-directifs, analyse de documents) pendant une période de six mois environ entre 2008 et 2009. L'analyse empirique fournit quatre résultats : a) de manière générale, les taxateurs de la caisse de chômage disposent d'un faible niveau de pouvoir discrétionnaire ; b) le degré de pouvoir discrétionnaire varie selon le type de tâche ; c) les agents sur le terrain rendent des comptes auprès d'une multiplicité d'acteurs, sur une variété d'aspects de leur travail et au travers de différents mécanismes de contrôle ; d) les outils de NGP et les nouvelles technologies informatiques ont peu d'impact sur l'étendue du pouvoir discrétionnaire des agents mais contribuent à influencer le type de redevabilité publique pratiquée à ce niveau. Summary in English This PhD dissertation deals with the role of public administration in policy implementation. In the Swiss context of unemployment insurance policy, it focuses on street-level bureaucracy, a specific type of public organisations and agents located at the frontline of public action, that is to say low-level civil servants who are in direct, daily and face-to-face contact with citizens. The dissertation aims at a deep understanding of what are the concrete impacts of two main important changes touching public sector organizations : New Public Management reforms (NPM) and Information and Communication technologies (ICT). The main research question consists in assessing the impacts of those reforms on two central issues regarding street-level bureaucrats : on the one hand, the effective degree of discretion frontline agents do have in implementing the federal law on unemployment insurance ; on the other hand, the ways through which these bureaucrats are held accountable about their action and decisions, i.e. accountability regimes at the street-level. These issues have been empirically addressed in the organisational context of a cantonal Unemployment Insurance Funds having experienced the above mentioned reforms. The organisation has been investigated through an in-depth ethnographic case-study (direct observation of daily work, semi-structured interwiews, documentary analysis) in 2008 and 2009 for approximately six months. The empirical analysis indicates that a) in general, street-level agents do exert low degree of policy discretion; b) the level of discretion is variable from one specific task to another ; c) frontline workers are held accountable to many actors, on various aspects of their work and through different mechanisms of control ; d) NPM and ICT instruments have few impact on the issue of policy discretion but more on the type of street-level accountability which is concretely practised at this level.

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PURPOSE OF REVIEW: To review the current experience with angiogenesis inhibitors in the treatment of gliomas. RECENT FINDINGS: Antiangiogenic therapy has recently reached the clinic with the approval of bevacizumab for recurrent glioblastomas. A number of promising antiangiogenic and vasculature-modifying agents are under investigation for newly diagnosed and recurrent malignant gliomas. A recurrence under ongoing or after antiangiogenic therapy is often characterized by a more aggressive and, in particular, invasive phenotype. SUMMARY: Despite impressively high radiological response rates in patients with recurrent malignant glioma, the duration of response is usually short-lived, and the observed effect to a large extent may be due to normalization of the disrupted blood-brain barrier and less due to a direct antitumor effect. Overall survival remains poor. Induction of invasive phenotypes and escape with proangiogenic alternative pathways are contributing to resistance. Investigation of combination regimes targeting several pathways will determine the possibilities to overcome the resistance to antiangiogenic therapy in malignant gliomas. This article summarizes the results of recent clinical trials in this field, points towards mechanisms of resistance arising under angiogenesis inhibition and discusses the challenges for the future.

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BACKGROUND: Tenofovir (TDF) use has been associated with proximal renal tubulopathy, reduced calculated glomerular filtration rates (cGFR) and losses in bone mineral density. Bone resorption could result in a compensatory osteoblast activation indicated by an increase in serum alkaline phosphatase (sAP). A few small studies have reported a positive correlation between renal phosphate losses, increased bone turnover and sAP. METHODS: We analysed sAP dynamics in patients initiating (n = 657), reinitiating (n = 361) and discontinuing (n = 73) combined antiretroviral therapy with and without TDF and assessed correlations with clinical and epidemiological parameters. RESULTS: TDF use was associated with a significant increase of sAP from a median of 74 U/I (interquartile range 60-98) to a plateau of 99 U/I (82-123) after 6 months (P < 0.0001), with a prompt return to baseline upon TDF discontinuation. No change occurred in TDF-sparing regimes. Univariable and multivariable linear regression analyses revealed a positive correlation between sAP and TDF use (P < or = 0.003), but no correlation with baseline cGFR, TDF-related cGFR reduction, changes in serum alanine aminotransferase (sALT) or active hepatitis C. CONCLUSIONS: We document a highly significant association between TDF use and increased sAP in a large observational cohort. The lack of correlation between TDF use and sALT suggests that the increase in sAP is because of the bone isoenzyme and indicates stimulated bone turnover. This finding, together with published data on TDF-related renal phosphate losses, this finding raises concerns that TDF use could result in osteomalacia with a loss in bone mineral density at least in a subset of patients. This potentially severe long-term toxicity should be addressed in future studies.

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Aim Macroevolutionary patterns and processes change substantially depending on levels of taxonomic and ecological organization, and the resolution of environmental and spatial variability. In comparative methods, the resolution of environmental and spatial variability often defines the number of selective regimes used to test whether phenotypic characteristics are adaptively correlated with the environment. Here, we examine how investigator choice of the number of selective regimes, determined by varying the resolution of among-species variability in the species climatic niche (hereafter called ecological scale'), influences trait morphological diversification among Eriogonoideae species. We assess whether adaptive or neutral processes drive the evolution of several morphological traits in these species. Location South-western North America. Methods We applied a phylogenetic framework of three evolutionary models to four morphological traits and the climatic niches of Eriogonoideae (in the buckwheat family, Polygonaceae). We tested whether morphological traits evolve in relation to climate by adaptive or neutral process, and whether the resulting patterns of morphological variability are conserved or convergent across the clade. We inspected adaptive models of evolution under different levels of resolution of among-species variability of the climatic niche. Results We show that morphological traits and climate niches of Eriogonoideae species are not phylogenetically conserved. Further, adaptive evolution of phenotypic traits is specific to climatic niche occupancy across this clade. Finally, the likely evolutionary process and the level of detectable niche conservatism change depending on the resolution of environmental variability of the climatic niche. Main conclusions Our study demonstrates the need to consider both the resolution of environmental variability and alternative evolutionary models to understand the morphological diversification that accompanies divergent adaptive evolution of lineages to climatic conditions.