12,078 research outputs found

    Boletim meteorológico da estação convencional de Cruz das Almas, BA: variabilidade e tendências climáticas.

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    Neste documento reúnem-se análises de dados dos elementos meteorológicos coletados na Estação Meteorológica da Embrapa Mandioca e Fruticultura entre os anos de 1971 e 2010, no município de Cruz das Almas, BA. O conjunto de informações geradas é de relevante importância para o conhecimento do clima da região, da sua variabilidade e das possíveis tendências climáticas, apesar da série de dados de apenas trinta anos. Considerando que todas as atividades sofrem influência do ambiente atmosfera e que o conhecimento dos seus elementos é base para sustentabilidade, a Embrapa Mandioca e Fruticultura atende a grande demanda da comunidade pela busca constante de informações das características climáticas da microrregião e dos seus dados meteorológicos que foram disponibilizados em escala mensal no formato digital. Portanto, uma referência para comunidade do município e importante ferramenta para o planejamento das empresas agrícolas, de ensino, de pesquisa e, principalmente, para o suporte na formulação de políticas públicasbitstream/item/145992/1/Documentos-216-Boletim-Meteorologico.pd

    The Dark Side of the Light: Mechanisms of Photocarcinogenesis

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    Ultraviolet radiation (UVR) can have a beneficial biologic impact on skin, but it is also the most significant environmental risk factor for skin cancer development. Photocarcinogenesis comprises a complex interplay between the carcinogenic UVR, skin, and the immune system. UVB is absorbed by the superficial skin layers and is mainly responsible for direct DNA damage, which, if unrepaired, can lead to mutations in key cancer genes. UVA is less carcinogenic, penetrates deeper in the dermis, and mainly causes indirect oxidative damage to cellular DNA, proteins, and lipids, via photosensitized reactions. UVR not only induces mutagenesis, altering proliferation and differentiation of skin cells, but also has several immunosuppressive effects that compromise tumor immunosurveillance by impairing antigen presentation, inducing suppressive cells, and modulating the cytokine environment. This review focuses upon molecular and cellular effects of UVR, regarding its role in skin cancer development.info:eu-repo/semantics/publishedVersio

    The Role of Δ(1232)\Delta(1232) in Two-pion Exchange Three-nucleon Potential

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    In this paper we have studied the two-pion exchange three-nucleon potential (2πE3NP)(2\pi E-3NP) using an approximate SU(2)×SU(2)SU(2) \times SU(2) chiral symmetry of the strong interaction. The off-shell pion-nucleon scattering amplitudes obtained from the Weinberg Lagangian are supplemented with contributions from the well-known σ\sigma-term and the Δ(1232)\Delta(1232) exchange. It is the role of the Δ\Delta-resonance in 2πE3NP2\pi E-3NP, which we have investigated in detail in the framework of the Lagrangian field theory. The Δ\Delta-contribution is quite appreciable and, more significantly, it is dependent on a parameter Z which is arbitrary but has the empirical bounds Z1/2|Z| \leq 1/2. We find that the Δ\Delta-contribution to the important parameters of the 2πE3NP2\pi E-3NP depends on the choice of a value for Z, although the correction to the binding energy of triton is not expected to be very sensitive to the variation of Z within its bounds.Comment: 14 pages, LaTe

    Gene identification for the cblD defect of vitamin B12 metabolism

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    Background Vitamin B12 (cobalamin) is an essential cofactor in several metabolic pathways. Intracellular conversion of cobalamin to its two coenzymes, adenosylcobalamin in mitochondria and methylcobalamin in the cytoplasm, is necessary for the homeostasis of methylmalonic acid and homocysteine. Nine defects of intracellular cobalamin metabolism have been defined by means of somatic complementation analysis. One of these defects, the cblD defect, can cause isolated methylmalonic aciduria, isolated homocystinuria, or both. Affected persons present with multisystem clinical abnormalities, including developmental, hematologic, neurologic, and metabolic findings. The gene responsible for the cblD defect has not been identified. Methods We studied seven patients with the cblD defect, and skin fibroblasts from each were investigated in cell culture. Microcell-mediated chromosome transfer and refined genetic mapping were used to localize the responsible gene. This gene was transfected into cblD fibroblasts to test for the rescue of adenosylcobalamin and methylcobalamin synthesis. Results The cblD gene was localized to human chromosome 2q23.2, and a candidate gene, designated MMADHC (methylmalonic aciduria, cblD type, and homocystinuria), was identified in this region. Transfection of wild-type MMADHC rescued the cellular phenotype, and the functional importance of mutant alleles was shown by means of transfection with mutant constructs. The predicted MMADHC protein has sequence homology with a bacterial ATP-binding cassette transporter and contains a putative cobalamin binding motif and a putative mitochondrial targeting sequence. Conclusions Mutations in a gene we designated MMADHC are responsible for the cblD defect in vitamin B12 metabolism. Various mutations are associated with each of the three biochemical phenotypes of the disorder

    Aquecimento global e aptidão da bananeira no Estado da Bahia.

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    O Brasil produziu aproximadamente 7 milhões de toneladas de banana no ano de 2008, sendo que o Nordeste é a principal região produtora (40%) e a Bahia o maior produtor nacional (20%), seguido de São Paulo (17%) (IBGE, 2009). O estresse por deficiência de água no solo é o maior limitador da expansão dos cultivos da bananeira em sequeiro, sendo este e o principal critério utilizado nos trabalhos de zoneamento climático no Nordeste brasileiro. A distribuição irregular das chuvas interfere na qualidade e produtividade de frutos e esses riscos podem ser aumentados com as previsões futuras de ocorrência de eventos extremos (seca e enchentes) e dos efeitos diretos da maior restrição hídrica no solo, devido ao aumento da evapotranspiração das culturas, relacionadas ao aquecimento global (Assad & Pinho, 2008; Semenov, 2009).O presente trabalho teve o objetivo de avaliar os impactos do aquecimento global na aptidão climática do estado da Bahia para o cultivo da bananeira em condições de sequeiro.pdf 239

    Corino de Andrade disease: mechanisms and impact on reproduction

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    Familial amyloid polyneuropathy was first described by Corino de Andrade in 1952 in Northern Portugal. It is a fatal autosomal dominant neurodegenerative disorder characterized by a progression of neurologic symptoms, beginning early in the reproductive life. The Transthyretin gene mutation originates a mutated protein that precipitates in the connective tissue as amyloid deposits. This disease is presently named Transthyretin-related hereditary amyloidosis. We performed an extensive review on this disease based on searches in Medical databases and in paper references. In this review, we briefly summarize the epidemiology and the mechanisms involved on amyloid deposition; we detailed how to evaluate the mechanisms implicated on the development of the major signs and symptoms associated with reproductive dysfunction; and we discuss the mechanisms involved in secondary sexual dysfunction after psychological treatments. Treatment of the disease is directed towards relieving specific symptoms in association with liver transplant, and molecular and genetic therapeutics. Although the current clinical trials indicate symptoms relief, no data on the reproductive function was reported. Thus, preimplantation genetic diagnosis is presently the only available technique that eradicates the disease as it avoids the birth of new patients.info:eu-repo/semantics/publishedVersio

    Aquecimento global e favorabilidade de ocorrência de Cosmopolites sordidus no Estado da Bahia.

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    A bananicultura nacional é caracterizada pela diversidade climática em que é explorada, uso de cultivares, forma de comercialização e exigências do mercado consumidor, ressaltando-se ainda, os baixos níveis de investimento e tecnologia adotados (Alves et al., 1995). Em 2008, o Brasil produziu aproximadamente 7 milhões de toneladas de banana no ano de 2008, sendo que o Nordeste é a principal região produtora (40%) e a Bahia o maior produtor nacional (20%), seguido de São Paulo (17%) (IBGE, 2008). Apesar de se destacar entre os maiores produtores mundiais de banana, a produtividade média no Brasil é baixa, devido, entre outros fatores, aos severos problemas fitossanitários da cultura. O conhecimento dos fatores ecológicos que interferem na população de uma praga é fundamental para o desenvolvimento e aplicação de programas de manejo pragas (Luckman & Metcalf, 1994). Adicionalmente, o aquecimento global poderá causar impactos significativos sobre a ocorrência de pragas. Na cultura da bananeira, a broca-do-rizoma, Cosmopolites sordidus (Germ.), é considerada a mais severa praga da bananeira, em razão dos prejuízos causados às plantas e da sua ampla distribuição geográfica (Fancelli & Mesquita, 2008). O presente trabalho teve o objetivo de avaliar os impactos do aquecimento global (aumento de temperatura) na favorabilidade à ocorrência de C. sordidus no Estado da Bahia.pdf 235
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