383 resultados para dimorphism


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[EN]GH is main regulator of body growth and composition, somatic development, intermediate metabolism and gender-dependent dimorphism in mammals. The liver is a direct target of estrogens because it expresses estrogen receptors which are connected with development, lipid metabolism and insulin sensitivity, hepatic carcinogenesis, protection from drug-induced toxicity and fertility. In addition, estrogens can modulate GH actions in liver by acting centrally, regulating pituitary GH secretion, and, peripherally, by modulating GHR-JAK2-STAT5 signalling pathway

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Le syndrome de détresse respiratoire du nouveau-né (SDR) est l’une des pathologies les plus fréquentes dont souffrent les bébés prématurés. Le SDR est causé par un déficit dans la synthèse du surfactant pulmonaire en raison de l’immaturité du poumon lors d’une naissance prématurée. Plusieurs éléments régulent le développement pulmonaire notamment les stéroïdes sexuels et les corticostéroïdes. Le sexe est aussi un élément régulateur du développement pulmonaire. En effet, les garçons sont plus atteints que les filles par le SDR. Ce dimorphisme sexuel est attribué aux androgènes. Le traitement anténatal aux glucocorticoïdes est prescrit aux femmes qui sont à risque d’accoucher prématurément. En effet, les corticostéroïdes favorisent la maturation pulmonaire anténatale. Également, il a été démontré que les microARNs sont primordiaux pour le développement pulmonaire. Ceci nous a conduit à étudier l’impact des androgènes sur le profil d’expression des microARNs lors de la transition du stade canaliculaire au stade sacculaire (jour gestationnel (JG)17.0 au JG18.0), période qui coïncide avec la montée de la synthèse et de la sécrétion du surfactant chez la souris. Tout d’abord, nous avons étudié la stabilité des gènes de normalisation (snoRNAs) afin de quantifier les microARNs par qPCR. Cette analyse a été effectuée avec 3 logiciels différents et sur plusieurs stades du développement notamment de la période pseudoglandulaire jusqu’au stade alvéolaire chez les deux sexes. On a identifié les meilleures combinaisons de gènes de normalisation les plus stables pour chaque stade du développement étudié ainsi que pour la période couvrant tous les stades étudiés. Ensuite nous avons analysé à GD17.0 et GD18.0 le profil d’expression des microARNs chez des fœtus mâles dont les mères ont été traitées au flutamide (anti-androgènes pure). Les résultats ont montré que 43 microARNs matures sont modulés par les androgènes à GD17.0 et 35 microARNs à GD18.0. Pour certains microARNs, nous avons identifié des cibles potentielles qui sont inversement modulées par les androgènes par rapport aux microARNs. Ces cibles sont impliquées dans plusieurs processus biologiques tels que le métabolisme des lipides et la prolifération cellulaire ainsi que dans des fonctions moléculaires tels que la liaison des facteurs de transcription. Des expériences de validation ont été effectuées par qPCR. Nos résultats ont montré que les androgènes régulent des processus qui peuvent être impliqués dans la maturation pulmonaire via la régulation des microARNs. En plus de l’intérêt porté aux androgènes dans la maturation pulmonaire, nous avons analysé l’expression d’enzymes de synthèse des corticostéroïdes dans le poumon fœtal humain. L’expression de l’enzyme 21-hydroxylase a été étudiée par qPCR et par immunobuvardage. Également la localisation de l’ARNm de cette enzyme clé de la synthèse des glucocorticoïdes, a été effectuée par hybridation in situ. L’ARNm de CYP21A2 a été détecté par qPCR dans les 34 échantillons analysés et dont les âges variaient entre 17 et 40 semaines de grossesse. Aucune corrélation, avec l’âge gestationnel ou le sexe, n’a été observée. Des niveaux significatifs de la protéine 21-hydroxylase ont été détectés dans nos échantillons. Nous avons investigué l’expression d’autres enzymes impliquées dans la voie de synthèse des glucocorticoïdes notamment CYP11B1, CYP11B2 et CYP17A1. Les ARNm des gènes CYP11B1, CYP11B2 n’ont pas été détectés dans nos échantillons, contrairement à CYP17A1 dont l’ARNm a été détecté dans tous nos tissus fœtaux analysés. La protéine de la 17α-hydroxylase a été détectée à de faibles niveaux. Nos résultats d’hybridation in situ ont montré que l’expression de CYP21A2 est localisée presqu’exclusivement dans l’épithélium pulmonaire distal. Nos résultats suggèrent que les produits de la 21-hydroxylase agiront via une action intracrine sur l’épithélium distal en activant le récepteur des glucocorticoïdes (GR). L’activation du récepteur des minéralocorticoïdes (MR) ne semble pas dépendre de produits de la 21-hydroxylase en raison des quantités importantes d’aldostérone circulante.

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A Síndrome de Down, também conhecida como Trissomia 21, representa a anomalia cromossómica mais comum da espécie humana. Caracteriza-se por um conjunto clássico de sinais e sintomas que afetam o desenvolvimento neuromotor e cognitivo. O diagnóstico da Síndrome de Down baseia-se numa série de sinais e sintomas, sendo a sua confirmação estabelecida através do estudo cromossómico. Nem toda a população afetada apresenta as mesmas características, sendo necessário uma identificação do cariótipo para um diagnóstico definitivo. Embora apresentando diferentes graus de severidade assim como inicio de manifestação dos primeiros sintomas em diferentes alturas, toda a população com SD apresenta morfismo característico da face e do sistema esquelético, alterações do SNC e início precoce da doença de Alzheimer. As características dento-maxilo-faciais afetam o normal funcionamento do sistema estomatognático. A maioria possui um padrão braquifacial com um desenvolvimento mandibular no sentido anti-horário e manifesta má-oclusão sob uma vasta etiologia. Consequentemente ocorrem alterações a nível da estética, postura, mastigação, respiração e fonação. Apresentam inclusive um controlo de placa ineficaz e pobre higienização oral, sendo os procedimentos de prevenção importantes. A Ortodontia tem um papel de relevo no tratamento das má-oclusões que contribuem para as limitações do paciente. Ressalte-se a importância da sensibilização dos familiares para a necessidade de higienização bucal destes pacientes, bem como o conhecimento pelo médico dentista acerca das principais manifestações bucais que acometem os pacientes portadores, para que o tratamento adequado seja oferecido e a qualidade de vida desses indivíduos preservada.

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Wydział Biologii: Instytut Antropologii

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Dissertação (mestrado)—Universidade de Brasília, Faculdade de Ciências da Saúde, Programa de Pós-Graduação em Ciências da Saúde, 2015.

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Dissertação (mestrado)—Universidade de Brasília, Faculdade de Ciências da Saúde, Programa de Pós-Graduação em Ciências da Saúde, 2015.

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without practical results so far. Protocols used in biotechnological cultured aquatic organisms aimed at increasing growth rates and disease resistance, have been studied and perfected. Among the available techniques, the application of chromosomal manipulation, although still nascent, is presented as a tool aimed at mitigating ecological and economical issues in shrimp farming. The polyploidization artificial method already employed in fish and shellfish, has been widely researched for use in farmed shrimp. Some limitations of this method of expansion in shrimp refer to a better knowledge of cytogenetic aspects, the level of sexual dimorphism and performance in growing conditions. To contribute on some of these issues, the present study aimed to characterize cytogenetic species Litopenaeus vannamei (Decapoda) and Artemia franciscana (Anostraca), analyze the effectiveness of methods for detection of ploidy, through the use of flow cytometry in processes of induction polyploidy cold thermal shock at different stages of development of newly fertilized eggs. Additionally, aimed also the qualitative and quantitative comparison of larval development between diploid and polyploid organisms, besides the identification of sexual dimorphism in L. vannamei, through geometric morphometrics. The results provide information relevant to the improvement and widespread use of biotechnological methods applied toward national productivity in shrimp farming

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Objetivo: El objetivo del presente estudio descriptivo, fue evaluar la posición del hueso hioides en los diferentes patrones esqueletales de Clase I, II y III mediante el trazado cefalométrico del triángulo hioideo propuesto por Bibby y Preston, estableciendo diferencias entre cada clase esqueletal. Materiales y métodos: La muestra consistió en 161 radiografías cefálicas laterales digitales, correspondientes a individuos de ambos sexos (75 hombres y 86 mujeres), entre edades de 9 y 18 años, las mismas que fueron divididas en tres subgrupos (Clase I, clase II y clase III) de acuerdo a los ángulos ANB y APDI. Se determinó la posición anteroposterior, vertical y angular del hueso hioides mediante el trazado cefalométrico del triángulo hioideo siendo el mentón, la tercera vértebra cervical y el hueso hioides las estructuras anatómicas utilizadas para el trazado del mismo. Se obtuvieron medidas estándar para cada clase esqueletal. Resultados: Se observaron diferencias estadísticamente significativas en la medida de H-Rgn entre clase I y II y entre clase II y III (p<0,005). El valor del ángulo del plano hioidal presentó diferencias estadísticamente significativas entre clase I y III y entre clase II y III (p<0,005). Se evidenciaron diferencias estadísticamente significativas entre hombres y mujeres con clase I esqueletal en la medida H-Rgn (p<0,005). Conclusiones: La posición del hueso hioides varía en los diferentes patrones esqueletales. Sin embargo, su posición en relación a la columna cervical presenta menos variabilidad que su relación con la mandíbula

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The hermit crab Paguras brevidactylus (Crustacea: Anomura: Paguridea) from the infralittoral area of Anchieta Island, Ubatuba, was characterized by population Structure (size, sex ratio, reproduction and recruitment) and growth. Animals were collected monthly during 1999 by SCUBA diving. A total of 1525 individuals was collected (633 males and 892 females), 695 of them were ovigerous females. Overall sex ratio was 0.7:1 in favour of females. The crabs showed a unimodal distribution with males significantly larger than females. Ovigerous females were collected during all months and in high percentages from 1.0 mm of shield length, demonstrating intense and Continuous reproduction. The longevity was approximately 24 months for males and 18 for females, which showed larger growth rate and reached sexual maturity earlier (two months) than males. The low number of males in this Population may be due to the longer life span. Moreover, the sexual dimorphism favours males during the intra- and interspecific fights by shell, food, reproduction and territory. Females demonstrated a short life cycle and intense reproduction.

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Aim: To investigate the existence of sexual dimorphism between the first and second permanent molars. Methods: A cross-sectional, observational, blind study using comparative and statistical descriptive procedures. The sample included 50 pairs of plaster casts from undergraduate dental students (25 men/25 women) from the Federal University of Paraíba, João Pessoa/PB, Brazil, aged 20-26 years. Odontometric measurements of first and second maxillary/mandibular, right/left permanent molars were performed. Mesiodistal (MD) and buccolingual/palatal (BL/BP) widths and the distance between the lingual cusps of corresponding molars in opposite quadrants, were measured. The data were analyzed by Student’s t test and ANOVA with Bonferroni (p≤0.05). Results: The crowns of all first molars were statistically larger in men than in women (p<0.05). Maxillary and mandibular left second molars (#27 and #37) did not differ in their MD widths (p=0.66, p=0.75), whereas mandibular left and right second molars (#37 and #47) showed statistically different BL widths (p=0.007 and p=0.008). As to the distance between the lingual cusps, only the first left-to-right mandibular molars (#36-46) showed no sex dimorphism (p=0.107). Conclusions: Molars are larger in males than in females. Individually, first molars demonstrated higher evidence of sex distinction than second molars.

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Sexual selection theory predicts that, in organisms with reversed sex roles, more polyandrous species exhibit higher levels of sexual dimorphism. In the family Syngnathidae (pipefish, seahorses, and seadragons), males provide all parental care by carrying developing embryos on their ventral surfaces, and females develop secondary sex characters. Syngnathids exhibit a variety of genetic mating patterns, making them an ideal group to test predictions of sexual selection theory. Here, we describe the mating system of the black-striped pipefish Syngnathus abaster, using 4 highly variable microsatellites to analyze parentage of 102 embryos. Results revealed that 1) both sexes mate multiple times over the course of a pregnancy (polygynandrous mating system), 2) eggs are spatially segregated by maternity within each brood pouch, and 3) larger females have higher mating success (Kolmogorov–Smirnov test; P < 0.05). Together with similar studies of other syngnathid species, our results support the hypothesis that the mating system is related to the intensity of sexual dimorphism.

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Investigating the ontogeny of niche differentiation enables to determine at which life-stages sexual segregation arises, providing insights into the main factors driving resource partitioning. We investigated the ontogeny of foraging ecology in Antarctic fur seals (Arctocephalus gazella), a highly dimorphic species with contrasting breeding strategies between sexes. Sequential δ(13)C and δ(15)N values of whiskers provided a longitudinal proxy of the foraging niche throughout the whole life of seals, from weaning, when size dimorphism is minimal to the age of 5. Females exhibited an early-life ontogenetic shift, from a total segregation during their first year at-sea, to a similar isotopic niche as breeding females as early as age 2. In contrast, males showed a progressive change in isotopic niche throughout their development such that 5-year-old males did not share the same niche as territorial bulls. Interestingly, males and females segregated straight after weaning with males appearing to feed in more southerly habitats than females. This spatial segregation was of similar amplitude as observed in breeding adults and was maintained throughout development. Such early-life niche differentiation is an unusual pattern and indicates size dimorphism and breeding constraints do not directly drive sexual segregation contrary to what has been assumed in otariid seals.

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This thesis addresses spiritual violence done to queer people in the sacrament of Communion, or Eucharist, in both Protestant and Roman Catholic churches in the U.S. Rooted in the sexual dimorphic interpretation of Genesis, theologians engendered Christianity with sexism and patriarchy, both of which have since developed into intricate intersections of oppressions. Religious abuse is founded on the tradition of exclusionary practices and is validated through narrow interpretations of Scripture that work to reassert the authority of the experiences of the dominant culture. The resultant culture of oppression manifests itself in ritualized spiritual violence. Queer people are deemed “unworthy” to take ‘the body and blood of the Christ’ and, in fact, are excluded altogether. This “unworthiness” is expressed as spiritual violence against queer people who are shunned and humiliated, internalize hateful messages, and are denied spiritual guidance or life-affirming messages. By “queering” Scripture, or reading the Bible anew through a framework of justice, queer people have begun to sacramentalize their experiences and reclaim their place at the table.

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The interactions between host individual, host population, and environmental factors modulate parasite abundance in a given host population. Since adult exophilic ticks are highly aggregated in red deer (Cervus elaphus) and this ungulate exhibits significant sexual size dimorphism, life history traits and segregation, we hypothesized that tick parasitism on males and hinds would be differentially influenced by each of these factors. To test the hypothesis, ticks from 306 red deer-182 males and 124 females-were collected during 7 years in a red deer population in south-central Spain. By using generalized linear models, with a negative binomial error distribution and a logarithmic link function, we modeled tick abundance on deer with 20 potential predictors. Three models were developed: one for red deer males, another for hinds, and one combining data for males and females and including "sex" as factor. Our rationale was that if tick burdens on males and hinds relate to the explanatory factors in a differential way, it is not possible to precisely and accurately predict the tick burden on one sex using the model fitted on the other sex, or with the model that combines data from both sexes. Our results showed that deer males were the primary target for ticks, the weight of each factor differed between sexes, and each sex specific model was not able to accurately predict burdens on the animals of the other sex. That is, results support for sex-biased differences. The higher weight of host individual and population factors in the model for males show that intrinsic deer factors more strongly explain tick burden than environmental host-seeking tick abundance. In contrast, environmental variables predominated in the models explaining tick burdens in hinds.

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Because males and females of a species express many homologous traits, sex-specific selection on these traits can shift the opposite sex away from its phenotypic optimum. This mode of sexually antagonistic selection, known as intralocus sexual conflict (IaSC), arises when the evolution of sexual dimorphism is constrained by the two sexes sharing a common gene pool. As IaSC has been historically overlooked, many outstanding questions remain. For example, what is its contribution in maintaining genetic variation for fitness in populations? What characters underlie this variation in fitness? How does the selection history of the population influence the standing genetic variation? I used the model organism Drosophila melanogaster to attempt to resolve some of these questions. The first part of my Master’s project involved assessing the detectability of sexually antagonistic alleles in populations at different stages of adaptation to the laboratory. For the second part of my Master’s project, I looked for evidence of conflict during the development of body size, a well-known sexually dimorphic trait. While the first part of my thesis proved inconclusive, the second part revealed a surprising source of sexual conflict in pre-adult stages of D. melanogaster.