996 resultados para Female plants


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1. Melanin pigments provide the most widespread source of coloration in vertebrates, but the adaptive function of such traits remains poorly known. 2. In a wild population of tawny owls (Strix aluco), we investigated the relationships between plumage coloration, which varies continuously from dark to pale reddish, and the strength and cost of an induced immune response. 3. The degree of reddishness in tawny owl feather colour was positively correlated with the concentration of phaeomelanin and eumelanin pigments, and plumage coloration was highly heritable (h(2) = 0.93). No carotenoids were detected in the feathers. 4. In mothers, the degree of melanin-based coloration was associated with antibody production against a vaccine, with dark reddish females maintaining a stronger level of antibody for a longer period of time compared to pale reddish females, but at a cost in terms of greater loss of body mass. 5. A cross-fostering experiment showed that, independent of maternal coloration, foster chicks reared by vaccinated mothers were lighter than those reared by nonvaccinated mothers. Hence, even though dark reddish mothers suffered a stronger immune cost than pale reddish mothers, this asymmetric cost was not translated to offspring growth. 6. Our study suggests that different heritable melanin-based colorations are associated with alternative strategies to resist parasite attacks, with dark reddish individuals investing more resources towards the humoral immune response than lightly reddish conspecifics.

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ABSTRACTIn contrast to animals, plants cannot move from their place of birth and, therefore, need to adapt to their particular habitat in order to survive. Thus, plant development is remarkably plastic, making plants an ideal system for the isolation of genes that account for intraspecific natural variation and possibly environmental adaptation. However, to date, this approach mostly identified null alleles and missed mutations with subtle effects. For instance, BREVIS RADIX (BRX) has been isolated as a key regulator of root growth through a naturally occurring loss-of-function allele in the Arabidopsis thaliana accession Uk-1 and is the founding member of a highly-conserved plant-specific gene family.In this work, we show that a strong selective pressure is acting on the BRX gene family and dates back before the monocot-dicot divergence. However, functional diversification is observed mainly in dicotyledon BRX family genes and is correlated with acceleration in the evolutionary rates in the N-terminal regions. Population genetic data revealed that BRX is highly conserved across Arabidopsis accessions and presents signatures of adaptation. Interestingly, a seven amino acid deletion polymorphism in BRX sequence was found in a few accessions, which seems to be responsible for their enhanced primary root growth. Nevertheless, BRX might not only be active in the root, as suggested by its expression in the shoot. Indeed, leaves and cotyledons of brx mutants are significantly smaller than wild- type. This phenotype is a direct consequence of the absence of BRX function in the shoot rather than an indirect effect of an altered root system growth. Interestingly, cotyledons of brx plants reflect the same physiological defects as the root. Moreover, phenotypes in BRX gain-of-function plants, such as epinastic leaves and increased epidermal cell size, could be associated with an increase in leaf brassinosteroid content.Collectively, these results indicate that BRX contributes to local adaptation by ubiquitously regulating plant growth, probably through the modulation of brassinosteroid biosynthesis.RÉSUMÉContrairement à la plupart des animaux, les plantes ne peuvent se mouvoir et doivent ainsi s'adapter à leur environnement pour survivre. Pour cette raison, elles représentent un système idéal pour l'identification de gènes contribuant à la variation naturelle intra- spécifique, ainsi qu'à l'adaptation. Cependant, cette approche a, jusqu'à présent, surtout permis d'isoler des allèles nuls et non des mutations conférant des effets plus subtiles. C'est le cas du gène Β REVIS RADIX (BRX), un régulateur clé de la croissance racinaire, qui a été identifié grâce à un allèle non-fonctionnel présent dans l'accession naturelle d'Arabidopsis thaliana Uk-1. BRX et ses homologues des plantes mono- et dicotylédones forment une famille très conservée et spécifique aux plantes.Dans ce travail, nous démontrons que la famille de gènes BRX est soumise à une forte pression de sélection qui remonte avant la divergence entre mono- et dicotylédones. Cependant, une diversification fonctionnelle a été observée chez les gènes des dicotylédones et corrèle avec une accélération de la vitesse d'évolution dans leur région N- terminale. Une analyse génétique de différentes accessions naturelles d'Arabidopsis a révélé que BRX est hautement conservé et présente des signatures d'adaptation. Remarquablement, un polymorphisme de délétion de sept acides aminés a été détecté dans quelques accessions et a pour conséquence une plus forte croissance de la racine primaire. Néanmoins, il semble que le rôle de BRX ne se limite pas qu'à la racine, comme indiqué par son expression dans les parties aériennes de la plante. En effet, les mutants brx présentent des cotylédons et des feuilles significativement plus petits que le type sauvage, une conséquence directe de l'absence d'activité de BRX dans ces organes. Nous avons aussi noté que les cotylédons des mutants brx, à l'instar des racines, ont une perception altérée de l'auxine et peuvent être complémentés par l'application exogène de brassinostéroïdes. De plus, dans des plantes présentant un gain de fonction BRX, les feuilles sont épinastiques et les cellules de leur épiderme plus grandes. Ces phénotypes sont accompagnés d'une augmentation de la concentration de brassinostéroïdes dans les feuilles. Conjointement, ces résultats démontrent que BRX contribue à une adaptation locale de la plante par la régulation générale de sa croissance, probablement en modulant la biosynthèse des brassinostéroïdes.

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The Aedes aegypti vector for dengue virus (DENV) has been reported in urban and periurban areas. The information about DENV circulation in mosquitoes in Colombian rural areas is limited, so we aimed to evaluate the presence of DENV in Ae. aegypti females caught in rural locations of two Colombian municipalities, Anapoima and La Mesa. Mosquitoes from 497 rural households in 44 different rural settlements were collected. Pools of about 20 Ae. aegypti females were processed for DENV serotype detection. DENV in mosquitoes was detected in 74% of the analysed settlements with a pool positivity rate of 62%. The estimated individual mosquito infection rate was 4.12% and the minimum infection rate was 33.3/1,000 mosquitoes. All four serotypes were detected; the most frequent being DENV-2 (50%) and DENV-1 (35%). Two-three serotypes were detected simultaneously in separate pools. This is the first report on the co-occurrence of natural DENV infection of mosquitoes in Colombian rural areas. The findings are important for understanding dengue transmission and planning control strategies. A potential latent virus reservoir in rural areas could spill over to urban areas during population movements. Detecting DENV in wild-caught adult mosquitoes should be included in the development of dengue epidemic forecasting models.

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Plants naturally produce the lipid-derived polyester cutin, which is found in the plant cuticle that is deposited at the outermost extracellular matrix of the epidermis covering nearly all aboveground tissues. Being at the interface between the cell and the external environment, cutin and the cuticle play important roles in the protection of plants from several stresses. A number of enzymes involved in the synthesis of cutin monomers have recently been identified, including several P450s and one acyl-CoA synthetase, thus representing the first steps toward the understanding of polyester formation and, potentially, polyester engineering to improve the tolerance of plants to stresses, such as drought, and for industrial applications. However, numerous processes underlying cutin synthesis, such as a controlled polymerization, still remain elusive. Suberin is a second polyester found in the extracellular matrix, most often synthesized in root tissues and during secondary growth. Similar to cutin, the function of suberin is to seal off the respective tissue to inhibit water loss and contribute to resistance to pathogen attack. Being the main constituent of cork, suberin is a plant polyester that has already been industrially exploited. Genetic engineering may be worth exploring in order to change the polyester properties for either different applications or to increase cork production in other species. Polyhydroxyalkanoates (PHAs) are attractive polyesters of 3-hydroxyacids because of their properties as bioplastics and elastomers. Although PHAs are naturally found in a wide variety of bacteria, biotechnology has aimed at producing these polymers in plants as a source of cheap and renewable biodegradable plastics. Synthesis of PHA containing various monomers has been demonstrated in the cytosol, plastids, and peroxisomes of plants. Several biochemical pathways have been modified in order to achieve this, including the isoprenoid pathway, the fatty acid biosynthetic pathway, and the fatty acid β-oxidation pathway. PHA synthesis has been demonstrated in a number of plants, including monocots and dicots, and up to 40% PHA per gram dry weight has been demonstrated in Arabidopsis thaliana. Despite some successes, production of PHA in crop plants remains a challenging project. PHA synthesis at high level in vegetative tissues, such as leaves, is associated with chlorosis and reduced growth. The challenge for the future is to succeed in synthesis of PHA copolymers with a narrow range of monomer compositions, at levels that do not compromise plant productivity. This goal will undoubtedly require a deeper understanding of plant biochemical pathways and how carbon fluxes through these pathways can be manipulated, areas where plant "omics" can bring very valuable contributions.

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Barraclough and co-workers (in a paper published in 1996) observed that there was a significant positive correlation between the rate of evolution of the rbcL chloroplast gene within families of flowering plants and the number of species in those families. We tested three additional data sets of our own (based on both plastid and nuclear genes) and used methods designed specifically for the comparison of sister families (based on random speciation and extinction). We show that, over all sister groups, the correlation between the rate of gene evolution and an increased diversity is not always present. Despite tending towards a positive association, the observation of individual probabilities presents a U-shaped distribution of association (i.e. it can be either significantly positive or negative). We discuss the influence of both phylogenetic sampling and applied taxonomies on the results.

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This paper compares the procedures of local Brazilian companies (those which have plants in Brazil only) with those of international Brazilian companies (which have plants in at least two countries) regarding the patent management. Although there are a lot more variables to consider when examining the issue of patents in companies, this study presents and analyzes the results of a qualitative research on the decision to patent innovations, the choice of countries where to patent and the strategic significance of patents to the company.

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L’objectiu principal és presentar un nou prototipus d’eina per al disseny de les plantes de tractament d’aigües residuals utilitzant models mecànics dinàmics quantificant la incertesa

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This study explores the role of early-life education for differences in cognitive functioning between men and women aged 60 and older from seven major urban areas in Latin America and the Caribbean. After documenting statistically significant differences in cognitive functioning between men and women for six of the seven study sites, I assess the extent to which these differences can be explained by prevailing male-female differences in education. I decompose predicted male-female differences in cognitive functioning based on various statistical models for later-life cognition and find robust evidence that male-female differences in education are a major driving force behind cognitive functioning differences between older men and women. This study therefore suggests that early-life differences in educational attainment between boys and girls during childhood have a lasting impact on gender inequity in cognitive functioning at older ages. Increases in educational attainment and the closing of the gender gap in education in many countries in Latin America and the Caribbean may thus result in both higher levels and a more gender-equitable distribution of later-life cognition among the future elderly in those countries.

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Most models on introgression from genetically modified (GM) plants have focused on small spatial scales, modelling gene flow from a field containing GM plants into a single adjacent population of a wild relative. Here, we present a model to study the effect of introgression from multiple plantations into the whole metapopulation of the wild relative. The most important result of the model is that even very low levels of introgression and selection can lead to a high probability that the transgene goes to fixation in the metapopulation. Furthermore, the overall frequency of the transgene in the metapopulation, after a certain number of generations of introgression, depends on the population dynamics. If there is a high rate of migration or a high rate of population turnover, the overall transgene frequency is much higher than with lower rates. However, under an island model of population structure, this increased frequency has only a very small effect on the probability of fixation of the transgene. Considering these results, studies on the potential ecological risks of introgression from GM plants should look not only at the rate of introgression and selection acting on the transgene, but also at the metapopulation dynamics of the wild relative.

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The practitioner, as well as specialist such as gynecologist and endocrinologist, may face in their office women with eating disorders, abnormalities of menstrual cycles and low bone mass, which may be the first hints of the female athlete triad. In these situations, the practitioner may search other findings of these triad by looking at some particular physical findings and by using appropriate questionnaire. In some advanced forms of this triad specific abnormalities of eating disorders (anorexia and boulimia) may be present as well as amenorrhea and osteoporosis, which may disturb the well-being and cause health damages of women practising sport either as amateur or in a elite setting. An appropriate handling of such disorders has to be proposed to these women.

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The cuticle is a physical barrier that prevents water loss and protects against irradiation, xenobiotics and pathogens. This classic textbook statement has recently been revisited and several observations were made showing that this dogma falls short of being universally true. Both transgenic Arabidopsis thaliana lines expressing cell wall-targeted fungal cutinase (so-called CUTE plants) or lipase as well as several A. thaliana mutants with altered cuticular structure remained free of symptoms after an inoculation with Botrytis cinerea. The alterations in cuticular structure lead to the release of fungitoxic substances and changes in gene expression that form a multifactorial defence response. Several models to explain this syndrome are discussed.

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Female Juvenile Justice Report from the Iowa Commission on the Status of Women

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Information of Gender-Specific Services for Adolescent Female Offenders produced by the Iowa Commission on the Status of Women.