978 resultados para DORSAL-HORN
Resumo:
Main developmental programs are highly conserved among species of the animal kingdom. Improper execution of these programs often leads to progression of various diseases and disorders. Here we focused on Drosophila wing tissue morphogenesis, a fairly complex developmental program, one of the steps of which - apposition of the dorsal and ventral wing sheets during metamorphosis - is mediated by integrins. Disruption of this apposition leads to wing blistering which serves as an easily screenable phenotype for components regulating this process. By means of RNAi-silencing technique and the blister phenotype as readout, we identify numerous novel proteins potentially involved in wing sheet adhesion. Remarkably, our results reveal not only participants of the integrin-mediated machinery, but also components of other cellular processes, e.g. cell cycle, RNA splicing, and vesicular trafficking. With the use of bioinformatics tools, these data are assembled into a large blisterome network. Analysis of human orthologues of the Drosophila blisterome components shows that many disease-related genes may contribute to cell adhesion implementation, providing hints on possible mechanisms of these human pathologies.
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Les résultats des recherches contemporaines, montrant notamment l'importance du raisonnement fluide, de la mémoire de travail (IMT) et de la vitesse de traitement (IVT) dans le fonctionnement cognitif, ont conduit les concepteurs de la WAIS-IV à introduire de nouvelles épreuves pour renforcer l'évaluation de ces dimensions cognitives. L'interprétation des scores de la WAIS-IV repose maintenant sur quatre indices factoriels (ICV, IRP, IMT et IVT), ainsi que sur le QIT. Les concepteurs de la WAIS-IV indiquent que l'un des objectifs de la révision consistait à actualiser les fondements théoriques de cette échelle. Pourtant, la structure globale de la WAIS-IV ne correspond que partiellement à celle proposée dans le modèle qui fait consensus aujourd'hui, le modèle de Cattell-Horn-Carroll (CHC). Par exemple, la WAIS-IV ne propose pas d'indice de raisonnement fluide, bien que les constructeurs soulignent l'importance de cette dimension dans le fonctionnement cognitif. Dans cet article, nous proposons, pour la WAIS-IV, les normes francophones de cinq scores composites CHC, à savoir le raisonnement fluide (Gf), compréhension-connaissances (Gc), le traitement visuel (Gv), la mémoire à court terme (Gsm), et l'IVT (Gs). Ces normes ont été établies en utilisant une procédure d'approximation statistique. À l'instar des scores CHC que nous avons proposés pour le WISCIV, ces normes pour la WAIS-IV permettent aux cliniciens de basculer vers une grille d'interprétation basée sur le modèle dominant et d'utiliser les cinq scores composites CHC en complément des quatre indices standard dans le cadre d'analyses normatives et ipsatives.
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A patient is described who presented with myoclonus of the first dorsal interosseus muscle of the right foot. This myoclonus occurred 18 months after trauma of the cutaneous branch of the deep peroneal nerve on the dorsal aspect of the foot. Tactile stimulation in the dermatome of this nerve, or an anaesthetic block of the deep peroneal nerve stopped the myoclonus. The different innervation between the efferent motor activity responsible for the movements and the sensory afference suppressing it points firmly towards involvement of central connections. However, abolition of the movement by anaesthesia suggests the presence of a peripheral ectopic generator. This finding confirms that focal myoclonus can have its origin in the peripheral nervous system and may be modulated by sensory inputs.
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Although many studies have been carried out to verify the involvement of the peripheral nervous system (PNS) in dystrophia myotonica (DM1) patients, the results remain controversial. The generation of DM1 transgenic mice displaying the human DM1 phenotype provides a useful tool to investigate the type and incidence of structural abnormalities in the PNS. In the present study, the morphological and morphometric analysis of semi-thin sections of sciatic and sural nerves, lumbar dorsal root ganglia (DRG) and lumbar spinal cords revealed that in DM1 transgenic mice carrying 300 CTG repeats, there is no change in the number and diameter of myelinated axons compared to wild type. Only a non-significant reduction in the percentage of thin myelinated axons was detected in electron micrographs of ultra-thin sciatic nerve sections. Analysis of the number of neurons did not reveal a loss in number of either sensory neurons in the lumbar DRG or motor neurons in the lumbar spinal cord in these DM1 mice. Furthermore, in hind limb muscle sections, stained with a neurofilament antibody and alpha-bungarotoxin, the intramuscular axon arborization appeared normal in DM1 mice and undistinguishable from that in wild-type mice. Moreover, in DM1 mice, there was no irregularity in the structure or an increase in the endplate area. Also statistical analysis did not show an increase in endplate density or in the concentration of acetylcholine receptors. Altogether, these results suggest that 300 CTG repeats are not sufficient to induce axonopathy, demyelination or neuronopathies in this transgenic mouse model.
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More than 246 million individuals worldwide are affected by diabetes mellitus (DM) and this number is rapidly increasing (http://www.eatlas. idf.org). 90% of all diabetic patients have type 2 DM, which is characterized by insulin resistance and b-cell dysfunction. Even though diabetic peripheral neuropathy (DPN) is the major chronic complication of DM its underlying pathophysiological mechanisms still remain unknown. To get more insight into the DPN associated with type 2 DM, we characterized the rodent model of this form of diabetes, the db/db mice. The progression of pathological changes in db/db mice mimics the ones observed in humans: increase of the body weight, insulin insensitivity, elevated blood glucose level and reduction in nerve conduction velocity (NCV). Decreased NCV, present in many peripheral neuropathies, is usually associated with demyelination of peripheral nerves. However, our detailed analysis of the sciatic nerves of db/db mice exposed for 4 months to hyperglycemia, failed to reveal any signs of demyelination in spite of significantly reduced NCV in these animals. We therefore currently focus our analysis on the structure of Nodes of Ranvier, regions of intense axo-glial interactions, which also play a crucial role in rapid saltatory impulse conduction. In addition we are also evaluating molecular changes in somas of sensory neurons projecting through sciatic nerve, which are localized in the dorsal root ganglia. We hope that the combination of these approaches will shed light on molecular alterations leading to DPN as a consequence of type 2 DM.
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The visual cortex in each hemisphere is linked to the opposite hemisphere by axonal projections that pass through the splenium of the corpus callosum. Visual-callosal connections in humans and macaques are found along the V1/V2 border where the vertical meridian is represented. Here we identify the topography of V1 vertical midline projections through the splenium within six human subjects with normal vision using diffusion-weighted MR imaging and probabilistic diffusion tractography. Tractography seed points within the splenium were classified according to their estimated connectivity profiles to topographic subregions of V1, as defined by functional retinotopic mapping. First, we report a ventral-dorsal mapping within the splenium with fibers from ventral V1 (representing the upper visual field) projecting to the inferior-anterior corner of the splenium and fibers from dorsal V1 (representing the lower visual field) projecting to the superior-posterior end. Second, we also report an eccentricity gradient of projections from foveal-to-peripheral V1 subregions running in the anterior-superior to posterior-inferior direction, orthogonal to the dorsal-ventral mapping. These results confirm and add to a previous diffusion MRI study (Dougherty et al., 2005) which identified a dorsal/ventral mapping of human splenial fibers. These findings yield a more detailed view of the structural organization of the splenium than previously reported and offer new opportunities to study structural plasticity in the visual system.
Resumo:
As espécies Fannia pusio Wiedeman, 1830 e Fannia trimaculata Stein, 1898 pertencem ao grupo canicularis e ao subgrupo pusio. Estas espécies são morfologicamente muito similares e geralmente são diferenciadas por uma fileira de cerdas no fêmur do terceiro par de pernas do macho. A análise com microscopia eletrônica de varredura mostrou na estrutura denominada "cellas", menor número de orifícios na superfície dorsal do ovo e, na superfície ventral, foi detectado menor rugosidade, ambos em F. trimaculata. Na larva, o estigma ou espiráculo protorácico é proeminente, onde F. trimaculata apresentou duas expansões tegumentares pequenas e sete longas de igual comprimento. Os machos de F. trimaculata apresentam uma fileira de cerdas localizadas mais externamente na faceta e, outra fileira de cerdas menores, a qual é ausente em machos de F. pusio, porém presente nas fêmeas de ambas as espécies.
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BACKGROUND: The amygdala, hippocampus, medial prefrontal cortex (mPFC) and brain-stem subregions are implicated in fear conditioning and extinction, and are brain regions known to be sexually dimorphic. We used functional magnetic resonance imaging (fMRI) to investigate sex differences in brain activity in these regions during fear conditioning and extinction. METHODS: Subjects were 12 healthy men comparable to 12 healthy women who underwent a 2-day experiment in a 3 T MR scanner. Fear conditioning and extinction learning occurred on day 1 and extinction recall occurred on day 2. The conditioned stimuli were visual cues and the unconditioned stimulus was a mild electric shock. Skin conductance responses (SCR) were recorded throughout the experiment as an index of the conditioned response. fMRI data (blood-oxygen-level-dependent [BOLD] signal changes) were analyzed using SPM8. RESULTS: Findings showed no significant sex differences in SCR during any experimental phases. However, during fear conditioning, there were significantly greater BOLD-signal changes in the right amygdala, right rostral anterior cingulate (rACC) and dorsal anterior cingulate cortex (dACC) in women compared with men. In contrast, men showed significantly greater signal changes in bilateral rACC during extinction recall. CONCLUSIONS: These results indicate sex differences in brain activation within the fear circuitry of healthy subjects despite similar peripheral autonomic responses. Furthermore, we found that regions where sex differences were previously reported in response to stress, also exhibited sex differences during fear conditioning and extinction.
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Scanning electron microscope (SEM) was done in order to study dorsal, ventral and lateral sides of 1st, 2nd, 3rd, 4th and 5th nymphal instars of Triatoma arthurneivai. The five nymphal instar can be recognized based on different pronotum, mesonotum and metanotum shapes and characteristics. In the 1st instar collar, hairless areas and tubercles are absent. The 2 nd instar presents collar, hairless areas and tubercles. In the 3rd instar occurs the development of wing pads. In the 4 th instar the four wing pads are expanded, but do not reach the abdomen and in the 5th instar the anterior wing pads almost overlap the posterior ones. At the ventral side, two metasternal glands openings (1+1) were found in all five nymphal instars. Brindley's gland evaporation areas (1+1) are located at the mesopleuron, as well as an evaporation area is located at the propleuron in all nymphal instars (1+1).
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Closely related species may be very difficult to distinguish morphologically, yet sometimes morphology is the only reasonable possibility for taxonomic classification. Here we present learning-vector-quantization artificial neural networks as a powerful tool to classify specimens on the basis of geometric morphometric shape measurements. As an example, we trained a neural network to distinguish between field and root voles from Procrustes transformed landmark coordinates on the dorsal side of the skull, which is so similar in these two species that the human eye cannot make this distinction. Properly trained neural networks misclassified only 3% of specimens. Therefore, we conclude that the capacity of learning vector quantization neural networks to analyse spatial coordinates is a powerful tool among the range of pattern recognition procedures that is available to employ the information content of geometric morphometrics.
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The interpretation of the Wechsler Intelligence Scale for Children-Fourth Edition (WISC-IV) is based on a 4-factor model, which is only partially compatible with the mainstream Cattell-Horn-Carroll (CHC) model of intelligence measurement. The structure of cognitive batteries is frequently analyzed via exploratory factor analysis and/or confirmatory factor analysis. With classical confirmatory factor analysis, almost all crossloadings between latent variables and measures are fixed to zero in order to allow the model to be identified. However, inappropriate zero cross-loadings can contribute to poor model fit, distorted factors, and biased factor correlations; most important, they do not necessarily faithfully reflect theory. To deal with these methodological and theoretical limitations, we used a new statistical approach, Bayesian structural equation modeling (BSEM), among a sample of 249 French-speaking Swiss children (8-12 years). With BSEM, zero-fixed cross-loadings between latent variables and measures are replaced by approximate zeros, based on informative, small-variance priors. Results indicated that a direct hierarchical CHC-based model with 5 factors plus a general intelligence factor better represented the structure of the WISC-IV than did the 4-factor structure and the higher order models. Because a direct hierarchical CHC model was more adequate, it was concluded that the general factor should be considered as a breadth rather than a superordinate factor. Because it was possible for us to estimate the influence of each of the latent variables on the 15 subtest scores, BSEM allowed improvement of the understanding of the structure of intelligence tests and the clinical interpretation of the subtest scores.
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Este trabalho visou descrever a morfologia e o tempo de desenvolvimento das larvas de Chrysomya putoria, um importante díptero para saúde pública e medicina legal. As amostras foram coletadas a cada duas horas e, a partir da 56ª hora, as coletas foram realizadas com intervalos de 12 horas até o abandono das larvas maduras do meio de criação. As larvas de C. putoria apresentaram um tempo total de desenvolvimento de 92 horas quando mantidas a 27 ºC com comprimento médio de 13,42 mm e características morfológicas peculiares que as diferenciam das outras espécies exóticas e autóctones do Brasil. O esqueleto cefalofaringeano das larvas de terceiro ínstar é robusto e esclerotizado; o gancho labial é completamente pigmentado e curvo, a parte posterior é mais larga que a anterior, mostrando-se levemente pontiagudo. Estas larvas não possuem esclerito oral acessório e o corno dorsal e o ventral apresentam áreas menos pigmentadas. Nota-se uma região não pigmentada em continuação aos cornos, destacando-se no tamanho na região do corno ventral com uma incisão média bem demarcada. Apresentam de 10 a 11 ramificações no espiráculo anterior, peritrema incompleto e presença do botão espiracular, a partir do segundo ínstar.
Resumo:
Criar mecanismos que produzam e dinamizem o alcance de novos produtos financeiros surge como uma condição necessária para estimular o investimento. Além das condições intrínsecas próprias de uma economia o financiamento é quase que a espinha dorsal para favorecer o desenvolvimento e crescimento económicos. Diversificar as fontes de financiamento para que estas se adaptem à realidade económico-financeira das empresas é essencial, pois não só possibilita o crescimento das empresas nacionais, mas também cria um ambiente de negócios propício ao investimento externo. Convicto da relevância, o presente trabalho tem como escopo uma temática que a nível nacional pouco se tem abordado: trata-se locação financeira que na gíria financeira é entendida por leasing - que de forma sintética se traduz num contrato pelo qual uma das partes concede à outra o gozo temporário de uma coisa contra uma retribuição, e que posteriormente pode ser adquirida, num prazo convencionado, mediante pagamento de um preço determinado ou determinável, nos termos do próprio contrato. O enfoque está em estudar a relevância assumida pelo leasing enquanto fonte de financiamento de médio e longo prazo, no contexto cabo-verdiano, comparativamente à outra fonte – empréstimo bancário de médio e longo prazo. O trabalho reveste-se de uma componente teórica e uma prática. Na componente teórica trata-se do tema no geral, abrangendo uma resenha histórica, o enquadramento legal, das sociedades de locação financeira e dos contratos de locação financeira, tratamento contabilístico, as características específicas que se associam ao tema em apreço e igualmente uma breve análise fiscal. A parte prática desenvolve uma análise comparativa do leasing com o empréstimo bancário de médio e longo prazo onde foram retiradas as conclusões chegadas com o estudo. Resumidamente, pode-se que o leasing é certamente uma das melhores opções de financiamento não só para empresas como igualmente para clientes particulares, sendo, uma opção rápida, simples e vantajosa para o cliente bancário, especialmente se o facto de a propriedade do bem não pertencer ao titular do leasing não causar qualquer incómodo. Create mechanisms that produce and streamline the range of new financial products emerges as a necessary condition to stimulate investment. In addition to its own intrinsic conditions of an economy funding is almost the backbone to promote economic development and growth. Diversify the sources of funding for these adapt to the reality of the economic-financial firms is essential because not only enables the growth of domestic companies, but also creates a business environment conducive to foreign investment. Convinced of the relevance, this work is scoped to a theme that nationally there has been little discussed: it is leasing in slang that is understood by financial leasing - which synthetically translates into a contract whereby one party grants to the another the temporary enjoyment of a thing against retribution, and that can later be acquired within the agreed upon payment of a specified or ascertainable under the contract. The focus is on studying the relevance assumed by leasing as a source of financing medium and long term, the Cape Verdean context, compared to other sources - bank loan of medium and long term. The work has a theoretical and a practical component. In the theoretical part it is the theme in general, covering a historical perspective, the legal framework, the leasing companies and financial leasing contracts, accounting treatment, specific characteristics that are associated to the topic at hand and equally a brief fiscal analysis. The practical part develops a comparative analysis of leasing with bank loan of medium and long term which were withdrawn with the conclusions reached with the study. Briefly, it may be that leasing is certainly one of the best financing options not only by companies as also by private customers, being a fast, simple and profitable for the bank customer, especially if the fact that the ownership of the property does not belong the holder of the lease does not cause any discomfort.
Resumo:
Chinavia Orian é um dos gêneros mais diversos da subfamília Pentatominae, distribuído nas regiões Afrotropical, Neártica e Neotropical. Para o Brasil, são conhecidas 32 espécies, dentre as quais 18 são endêmicas. Do total de espécies com registro para o Brasil, 18 têm algum tipo de registro com plantas-hospedeiras, a maioria delas cultivadas; apenas seis espécies têm os imaturos conhecidos ou algum aspecto de sua biologia estudado. Neste trabalho, é fornecida uma chave pictórica para os adultos das espécies registradas no Brasil, acompanhada da diagnose comparada de cada uma delas, além das informações disponíveis na literatura sobre imaturos e biologia das espécies. Duas novas sinonímias são propostas: Acrosternum (Chinavia) bellum Rolston, 1983 é sinônimo júnior de Chinavia nigrodorsata (Breddin, 1903) e Acrosternum (Chinavia) panizzii Frey-da-Silva & Grazia, 2001 é sinônimo júnior de Chinavia obstinata (Stål, 1860). Chinavia nigritarsis (Stål, 1872), anteriormente considerada sinônimo júnior de Chinavia gravis (Walker, 1867), é revalidada. Fotografias coloridas do aspecto dorsal de todas as espécies são fornecidas, a maioria delas confeccionadas a partir do material-tipo estudado. Novos registros de distribuição geográfica e de associação com plantas-hospedeiras no Brasil são apresentados.
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Datos sobre recuentos vertebrales, branquiales y radios de las aletas dorsal y anal de las anchovetas peruanas. Como las variaciones del numero de vértebras son por lo general más usadas para la diferenciación de poblaciones de peces, en esta primera contribución se presenta el análisis estadísticos del número de vertebras en diferentes localidades, dejando los otros datos para un trabajo futuro.