14,436 research outputs found
Análise da atividade anti-apoptótica do gene iap-3 de Anticarsia gemmatalis MNPV.
bitstream/CENARGEN/24245/1/bp042.pd
Combining exclusive semi-leptonic and hadronic B decays to measure |V_ub|
The Cabibbo-Kobayashi-Maskawa matrix element |V_ub| can be extracted from the
rate for the semi-leptonic decay B -> pi + l + antineutrino_l, with little
theoretical uncertainty, provided the hadronic form factor for the B -> pi
transition can be measured from some other B decay. In here, we suggest using
the decay B -> pi J\psi. This is a color suppressed decay, and it cannot be
properly described within the usual factorization approximation; we use instead
a simple and very general phenomenological model for the b d J\psi vertex. In
order to relate the hadronic form factors in the B -> pi J\psi and B -> pi + l
+ antineutrino_l decays, we use form factor relations that hold for
heavy-to-light transitions at large recoil.Comment: Latex, 7 pages, no figure
The low dimensional dynamical system approach in General Relativity: an example
In this paper we explore one of the most important features of the Galerkin
method, which is to achieve high accuracy with a relatively modest
computational effort, in the dynamics of Robinson-Trautman spacetimes.Comment: 7 pages, 5 figure
Group Theory analysis of phonons in two-dimensional Transition Metal Dichalcogenides
Transition metal dichalcogenides (TMDCs) have emerged as a new two
dimensional materials field since the monolayer and few-layer limits show
different properties when compared to each other and to their respective bulk
materials. For example, in some cases when the bulk material is exfoliated down
to a monolayer, an indirect-to-direct band gap in the visible range is
observed. The number of layers ( even or odd) drives changes in space
group symmetry that are reflected in the optical properties. The understanding
of the space group symmetry as a function of the number of layers is therefore
important for the correct interpretation of the experimental data. Here we
present a thorough group theory study of the symmetry aspects relevant to
optical and spectroscopic analysis, for the most common polytypes of TMDCs,
i.e. , and , as a function of the number of layers. Real space
symmetries, the group of the wave vectors, the relevance of inversion symmetry,
irreducible representations of the vibrational modes, optical selection rules
and Raman tensors are discussed.Comment: 32 pages, 4 figure
Insights into a dinoflagellate genome through expressed sequence tag analysis
BACKGROUND: Dinoflagellates are important marine primary producers and grazers and cause toxic "red tides". These taxa are characterized by many unique features such as immense genomes, the absence of nucleosomes, and photosynthetic organelles (plastids) that have been gained and lost multiple times. We generated EST sequences from non-normalized and normalized cDNA libraries from a culture of the toxic species Alexandrium tamarense to elucidate dinoflagellate evolution. Previous analyses of these data have clarified plastid origin and here we study the gene content, annotate the ESTs, and analyze the genes that are putatively involved in DNA packaging. RESULTS: Approximately 20% of the 6,723 unique (11,171 total 3'-reads) ESTs data could be annotated using Blast searches against GenBank. Several putative dinoflagellate-specific mRNAs were identified, including one novel plastid protein. Dinoflagellate genes, similar to other eukaryotes, have a high GC-content that is reflected in the amino acid codon usage. Highly represented transcripts include histone-like (HLP) and luciferin binding proteins and several genes occur in families that encode nearly identical proteins. We also identified rare transcripts encoding a predicted protein highly similar to histone H2A.X. We speculate this histone may be retained for its role in DNA double-strand break repair. CONCLUSION: This is the most extensive collection to date of ESTs from a toxic dinoflagellate. These data will be instrumental to future research to understand the unique and complex cell biology of these organisms and for potentially identifying the genes involved in toxin production
Estoque de carbono e quantificação de substâncias húmicas em latossolo submetido a aplicação contÃnua de lodo de esgoto.
Este estudo teve como objetivo avaliar o efeito da aplicação contÃnua de doses de lodo de esgoto oriundo da Estação de Tratamento de Esgoto de Barueri, SP, sobre os teores e estoques de C e sobre as alterações na distribuição de substâncias húmicas em Latossolo Vermelho distroférrico. O experimento foi instalado em 1999, no Campo Experimental da Embrapa Meio Ambiente, em Jaguariúna-SP; os dados foram obtidos após a sexta aplicação de lodo e cultivo sucessivo de milho. Foram utilizadas, nas diferentes parcelas experimentais, as seguintes doses acumuladas de lodo de esgoto (base seca): 0, 30, 60, 120 e 240 Mg ha-1, sendo estudados os tratamentos: (L0) testemunha sem adição de lodo; e aplicação de lodo de esgoto visando fornecer uma (L1), duas (L2), quatro (L4) e oito (L8) vezes a dose de N requerida pelo milho. Foram avaliados os teores e o estoque de C orgânico nas camadas de solo de 0-10, 10-20, 20-40 e 40-60 cm. Os teores de C associados à s substâncias húmicas foram avaliados na camada de solo de 0-10 cm. O teor e o estoque de C orgânico aumentaram com o acréscimo nas doses de lodo de esgoto aplicadas, até a camada de solo de 0-20 cm. A maior parte (50-66 %) do C associado à s substâncias húmicas está presente no solo na forma de humina, seguido por C-fração ácidos fúlvicos e C-fração ácidos húmicos, nesta ordem. A aplicação de lodo de esgoto implica maior acúmulo de substâncias húmicas no solo, mas as proporções de C-humificado da matéria orgânica não são alteradas
CONTAINER FOR THE TRANSPORTATION AND CONSERVATION OF IMMUNOBIOLOGICALS
A container was developed for the transport and conservation of immunological products under low temperatures of between 2 and 8 º C, within a time span of 8 hours. The container is practical, simple and userfriendly, and can be used in places without electric power, and all these advantages are added of low operational costs. The container proposed aims at meeeting the demand of the Programa Nacional de Imunizações (PNI- the National Immunization Program), through Cold Chain, which sets the standards for all the procedures concerning conservation, handling, distribution and transport of the vaccine from the laboratory that produces it to the moment of inoculation.Innitially, the container was specifically developed for Vaccine for Inactive Influenza Virus against flu, which, according to a survey conducted with laboratories, is the most widely consumed, and whose conservation time span is also applicable to other immunobiologicals After the design and construction of the prototype, the container was exhaustively tested under different weather conditions. The results of the experiment are being exposed and discussed in this paper and the prototype lived up to the expectations of the reserachers in terms of the time spans and temperatures foreseen for the conservation of the vaccine selected
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