Mostrando recursos 1 - 20 de 331.715

  1. Pênfigo vulgar : relato de caso

    Adaime, Ana Martha
    Pênfigo vulgar é uma doença mucocutânea crônica, auto-imune e rara que se caracteriza pela formação de bolhas intra-epiteliais resultantes da perda de adesão entre as células epiteliais pela deposição de auto-anticorpos. Usualmente, acomete indivíduos na faixa etária dos 50 anos de idade e pode exibir predisposição genética. As lesões bucais e cutâneas estão presentes ao mesmo tempo em 90% dos pacientes, além disso, as lesões bucais precedem as de pele em 50% dos casos. Clinicamente, as bolhas rapidamente se rompem deixando úlceras dolorosas com fundo necrótico e halo eritematoso. Porém, a mucosa e a pele normal podem apresentar formação de...

  2. Evolução dos fenótipos e estrutura do pelo em roedores : uma abordagem dos genes MC1r e Edar

    Gonçalves, Gislene Lopes
    A variação morfológica está presente, em alguma maneira, em populações naturais de todos os organismos, sendo particularmente evidenciada na coloração da pelagem e a estrutura de pelos modificados em mamíferos, os quais apresentam grande diversidade e convergências entre as linhagens corresponentes. Neste estudo, é investigado o papel dos genes candidatos Mc1r e Edar na determinação dos fenótipos coloração da pelagem e estrutura espinhenta do pelo, respectivamente, tendo como hipótese o envolvimento de variações estruturais e/ou regulatórias na geração da diversidade morfológica observada. O estudo com o gene Mc1r incluiu a caracterização de variantes genéticas em fenótipos claro, escuro e melânico...

  3. Modelos de investigação etiopatológica de anormalidades do calibre vascular retiniano: integração de fatores epidemiológicos, clínicos e moleculares

    Moreira, Marina Beltrami
    Introdução: Hipertensão arterial sistêmica é um dos principais fatores de risco para doença cardiovascular, que hoje constitui a principal causa de morbimortalidade no Brasil. Além das doenças macrovasculares, a hipertensão também está implicada na etiopatogenia de doenças microvasculares, a retinopatia hipertensiva. Alteração no calibre dos vasos da retina ocorre precocemente. Redução do calibre arteriolar e aumento do calibre venular associaram-se diretamente com incidência de doenças cardiovasculares e mortalidade por qualquer causa em grandes estudos de coorte. Estreitamento arteriolar é capaz de predizer incidência de hipertensão. Além do valor prognóstico, a visualização dos vasos da retina permite o estudo de alterações...

  4. MOIRAE : a computational strategy to predict 3-D structures of polypeptides

    Dorn, Márcio
    Currently, one of the main research problems in Structural Bioinformatics is associated to the study and prediction of the 3-D structure of proteins. The 1990’s GENOME projects resulted in a large increase in the number of protein sequences. However, the number of identified 3-D protein structures have not followed the same growth trend. The number of protein sequences is much higher than the number of known 3-D structures. Many computational methodologies, systems and algorithms have been proposed to address the protein structure prediction problem. However, the problem still remains challenging because of the complexity and high dimensionality of a protein...

  5. A evolução do comportamento canibal e não-canibal em imaturos de Heliconius erato phyllis e evidências da herança do reconhecimento de parentesco lagarta-ovo

    Nardin, Janaína de
    O reconhecimento de parentes é importante para a evolução de comportamentos como o altruísmo e a cooperação. As lagartas recém-eclodidas de Heliconius erato phyllis podem ser canibais e reconhecer ovos irmãos, canibalizando preferencialmente não-parentes quando há a opção de canibalizar um ou outro. A presente Dissertação compreende três artigos relacionados, especificados a seguir. O primeiro enfoque foi buscar responder se o reconhecimento de parentesco observado nessa espécie (demonstrado em artigo publicado em 2011 pela autora) é compatível com o modelo de evolução por seleção de parentesco, o qual postula que o comportamento altruísta teria vantagens sob determinadas condições. Foram feitas...

  6. Tuco-tucos do pampa rio-grandense : a filogeografia de Ctenomys torquatus (rodentia-ctenomyidae) e a descrição de uma nova espécie

    Roratto, Paula Angélica
    O tuco-tuco de colar, Ctenomys torquatus, possui uma das maiores distribuições geográficas entre estes roedores, habitando os campos de baixa altitude em toda metade norte do Uruguai e na porção sul do estado do Rio Grande do Sul, Brasil. A variabilidade cromossômica, comum em espécies deste roedor subterrâneo, ocorre em apenas algumas populações periféricas de C. torquatus, particularmente em regiões na quais grandes cursos d’água separam formas cromossômicas distintas. Com os objetivos de descrever os padrões filogeográficos de C. torquatus, bem como o efeito de grandes rios na estruturação de populações e diferentes cariótipos, o presente estudo fez uso de...

  7. Genetic Algorithm optimised Chemical Reactors network: A novel technique for alternative fuels emission prediction

    Leong, C.C.; Blakey, S.; Wilson, C.W.
    Sustainability of the conventional jet fuels and climate change has attracted the aviation sector to diversity to alternative fuels. However, fuel diversification requires an assessment of the long term impact to engine performance and engine emissions through the combustion process, as alternative fuels are not as well understood as conventional jet fuel. A detailed experimental study on alternative fuels emissions across the entire aircraft fleet is impractical. Therefore a plausible method of computer modelling combined Genetic Algorithm and Chemical Reactors network was developed to predict alternative fuels gaseous emissions, namely, Carbon Monoxide, Nitrogen Oxides and Unburned Hydrocarbons in aircraft engines....

  8. Characterization of the intestinal microbiota of natural populations of Lutzomyia evansi: vector of visceral Leishmaniasis

    Vivero Gómez, Rafael José
    Abstract: Lutzomyia evansi (Diptera: Psychodidae) is a phlebotomine “sandfly” insect endemic to the Caribbean coast of Colombia with epidemiological significance for being the main vector of leishmaniasis disease, which is caused by Leishmania spp parasites. Sand flies (164 species in Colombia) in general are able to transmit other parasites as Bartonella spp, and virus mostly from vesiculovirus group, affecting human and animal health. This group of insects has been studied in Colombia in relation to vectorial role, geographical distribution and epidemiological importance, but vaccine absence for the most important disease they transmit (leishmaniasis) encourage the implementation of vector control measures as...

  9. Mejora de tiempos de entrega en un flow shop híbrido flexible usando técnicas inteligentes. Aplicación en la industria de tejidos técnicos

    Arango Marín, Jaime Antero
    Se busca aportar herramientas útiles para la programación de producción en la industria de tejidos técnicos. Se parte de las condiciones actuales de la programación de producción en este tipo de industria y de los antecedentes en la literatura científica sobre modelos aplicables a estos entornos. Se propone un modelo de solución por técnicas inteligentes a la problemática de la secuenciación y asignación de tareas en los entornos flow shop híbrido flexible considerando situaciones como: paralelismo entre máquinas no relacionadas, tiempos de montaje dependientes de la secuencia, entrada dinámica de trabajos, restricción de elegibilidad, maleabilidad y lotes de transferencia variables...

  10. PhenoScanner: a database of human genotype-phenotype associations

    Staley, James R.; Blackshaw, James; Kamat, Mihir A.; Ellis, Steve; Surendran, Praveen; Sun, Benjamin B.; Paul, Dirk S.; Freitag, Daniel; Burgess, Stephen; Danesh, John; Young, Robin; Butterworth, Adam S.
    PhenoScanner is a curated database of publicly available results from large-scale genetic association studies. This tool aims to facilitate “phenome scans”, the cross-referencing of genetic variants with many phenotypes, to help aid understanding of disease pathways and biology. The database currently contains over 350 million association results and over 10 million unique genetic variants, mostly single nucleotide polymorphisms. It is accompanied by a web-based tool that queries the database for associations with user-specified variants, providing results according to the same effect and non-effect alleles for each input variant. The tool provides the option of searching for trait associations with proxies...

  11. Population Genetic Patterns of Threatened European Mudminnow (Umbra krameri Walbaum, 1792) in a Fragmented Landscape: implications for Conservation Management

    Takács Péter; Erős Tibor; Specziár András; Sály Péter; Vitál Zoltán; Ferincz Árpád; Molnár Tamás; Szabolcsi Zoltán; Bíró Péter; Csoma Eszter (1978-) (molekuláris biológus, mikrobiológus)

  12. High plasticity of loggerhead nesting site fidelity: from using repeatedly the same small beach during different seasons to deposit consecutive nests in different islands distant more than 100 km

    Abella Pérez, Elena; Sanz, Paula; Loureiro, Nuno de Santos; Cozens, Jacquie; Oujo-Alamo, Carolina; Martins, Samir; Marco, Adolfo; Varo Cruz, Nuria; López-Jurado, Luis Felipe

    [EN] Sea turtles exhibit a strong natal homing associated with a high nesting site philopatry. Mark-recapture and genetic studies confirm these patterns suggesting differences among and within species. In the present study, we have analysed the degree of nest site fidelity of a loggerhead population nesting on the islands of Cape Verde and have evaluated the existence of intrapopulational variability in this trait. The loggerhead is the only sea turtle species that nests in Cape Verde, and 15,000–25,000 nests per season have been estimated for the whole archipelago.


  13. Lost at sea: Genetic, oceanographic and meteorological evidence for storm-forced dispersal

    Monzón Argüello, Catalina; Dell’ Amico, F.; Morinière, P.; Marco, Adolfo; López-Jurado, Luis Felipe; Hays, Graeme; Scott, Rebecca; Marsh, Robert; Lee, Patricia

    [EN] For many species, there is broad-scale dispersal of juvenile stages and/or long-distance migration of individuals and hence the processes that drive these various wide-ranging move- ments have important life-history consequences. Sea turtles are one of these paradigmatic long-distance travellers, with hatchlings thought to be dispersed by ocean currents and adults often shuttling between distant breeding and foraging grounds. Here, we use multi- disciplinary oceanographic, atmospheric and genetic mixed stock analyses to show that juvenile turtles are encountered ‘downstream’ at sites predicted by currents. However, in some cases, unusual occurrences of juveniles are more readily explained by storm events and...

  14. Asynchronous spore germination in isogenic natural isolates of Saccharomyces paradoxus.

    Stelkens, RB; Miller, EL; Greig, D
    Spores from wild yeast isolates often show great variation in the size of colonies they produce, for largely unknown reasons. Here we measure the colonies produced from single spores from six different wild Saccharomyces paradoxus strains. We found remarkable variation in spore colony sizes, even among spores that were genetically identical. Different strains had different amounts of variation in spore colony sizes, and variation was not affected by the number of preceding meioses, or by spore maturation time. We used time-lapse photography to show that wild strains also have high variation in spore germination timing, providing a likely mechanism for...

  15. The detection of chromosomal abnormalities in human oocytes and preimplantation embryos by molecular cytogenetic analysis.

    Fragouli, E.
    Chromosome abnormalities are observed very frequently in humans. Several types of structural chromosome abnormalities have been identified, with chromosome translocations, both reciprocal and Robertsonian, being the most common in the population. Balanced carriers of such rearrangements could be at risk of generating abnormal offspring due to the meiotic segregation of the translocation. Preimplantation Genetic Diagnosis (PGD) has allowed the extensive cytogenetic investigation of embryos from such patients with the application of Fluorescent in situ hybridisation (FISH). The first part of this work involved the development of robust three-colour FISH protocols for their clinical application for the PGD for three reciprocal...

  16. The checkpoint role of Cdc18 in fission yeast.

    Fersht, N.
    The highly conserved eukaryotic checkpoints keep tight control over cell cycle progression, arresting the cell in response to incomplete DNA replication or DNA damage. In fission yeast, Rad3 (functional homologue of ATM, mutated in ataxia telangiectasia, and structural homologue of ATR, ataxia telangiectasia and rad3 related) is necessary for activation of both replication and damage checkpoints. However, despite the identification of many checkpoint genes, the actual sequence of upstream events leading to Rad3 activation remains unclear. The aim of my project was to identify and characterise the Rad3- dependent DNA damage/perturbed replication sensors and checkpoint activators. A genetic screen was...

  17. Efficient chemo-enzymatic gluten detoxification: reducing toxic epitopes for celiac patients improving functional properties

    Ribeiro, Miguel; Nunes, Fernando M.; Guedes, Sofía; Domingues, Pedro; Silva, Amelia M.; Carrillo Becerril, Jose Maria; Rodriguez De Quijano Urquiaga, Marta; Branlard, Gerard; Igrejas, Gilberto
    Protein engineering of gluten, the exogenous effector in celiac disease, seeking its detoxification by selective chemical modification of toxic epitopes is a very attractive strategy and promising technology when compared to pharmacological treatment or genetic engineering of wheat. Here we present a simple and efficient chemo-enzymatic methodology that decreases celiac disease toxic epitopes of gluten proteins improving its technological value through microbial transglutaminase-mediated transamidation of glutamine with n-butylamine under reducing conditions. First, we found that using low concentrations of amine-nucleophile under non-reducing conditions, the decrease in toxic epitopes is mainly due to transglutaminase-mediated cross-linking. Second, using high amine nucleophile concentrations...

  18. Controlled exercise as a tool for preventing obesity and metabolic diseases in Arg64 carrier women.

    Szendrei Szabo, Barbara; Cupeiro Coto, Rocio; Amigo, Teresa; González Lamuno, Domingo; Benito Peinado, Pedro José; Calderon Montero, Francisco Javier
    Genética y ejercicio.

  19. Genetic genealogical models in rare event analysis

    Cérou, Frédéric; Del Moral, Pierre; Le Gland, François; Lezaud, Pascal
    Nous présentons dans cet article un algorithme de particules en interaction de type génétique et un modèle généalogique pour estimer une classe d'événements rares provenant de la physique et de l'analyse des réseaux. Nous exprimons la loi d'un processus de Markov qui atteint un événement rare comme un modèle de Feynman--Kac dans l'espace des trajectoires. Nous montrons comment ces modèles de branchement de particules décrits dans des travaux précédents peuvent être utilisés pour estimer la probabilité d'événements rares, ainsi que la loi du processus dans ce régime. \\ We present in this article a genetic type interacting particle systems algorithm...

  20. A Parallel Hybrid Genetic Algorithm for Protein Structure Prediction on the Computational Grid

    Tantar, Alexandru-Adrian; Melab, Nouredine; Talbi, El-Ghazali; Parent, B.; Horvath, D.
    International audience

Aviso de cookies: Usamos cookies propias y de terceros para mejorar nuestros servicios, para análisis estadístico y para mostrarle publicidad. Si continua navegando consideramos que acepta su uso en los términos establecidos en la Política de cookies.