10,893 research outputs found
Scotin, a novel p53-inducible proapoptotic protein located in the ER and the nuclear membrane
p53 is a transcription factor that induces growth arrest or apoptosis in response to cellular stress. To identify new p53-inducible proapoptotic genes, we compared, by differential display, the expression of genes in spleen or thymus of normal and p53 nullizygote mice after γ-irradiation of whole animals. We report the identification and characterization of human and mouse Scotin homologues, a novel gene directly transactivated by p53. The Scotin protein is localized to the ER and the nuclear membrane. Scotin can induce apoptosis in a caspase-dependent manner. Inhibition of endogenous Scotin expression increases resistance to p53-dependent apoptosis induced by DNA damage, suggesting that Scotin plays a role in p53-dependent apoptosis. The discovery of Scotin brings to light a role of the ER in p53-dependent apoptosis
Heteroquelia em Ucides cordatus (Linnaeus, 1763) (Crustacea, Brachyura, Ocypodidae) na Área de Proteção Ambiental (APA) do Delta do Parnaiba.
Atributos químicos do solo em sistemas agrossilvipastoris do semiárido cearense com a presença do fogo.
Resumo: A análise dos atributos químicos do solo é uma importante ferramenta para se conhecer a qualidade e as deficiências do solo. Objetivou-se avaliar a fertilidade do solo sob Luvissolo Crômico Órtico e Luvissolo Hipocrômico Órtico em sistema agrossilvipastoril. O presente trabalho foi realizado na Embrapa Caprinos e Ovinos, os sistemas avaliados consistiam de diferentes tipos de manejo: agrosilvipastoril, silvipastoril com queima, silvipastoril sem queima, mata nativa com queima, mata nativa sem queima e sistema tradicional. O delineamento foi inteiramente casualizado em parcelas subdivididas, sendo as parcelas, os manejos e as subparcelas as profundidades (0-0,10 e 0,10-0,20 m); com cinco repetições. Houve diferença significativa nos diferentes manejos para todo os atributos químicos, exceto Mg, Al e V. Os ambientes silvipastoril com e sem queima apresentaram maiores valores para os atributos químicos em relação ao sistema tradicional. Os manejos silvipastoril sem e com queima proporcionaram as maiores concentrações para pH e K; e P, Ca e Na, respectivamente. O manejo agrossilvipastoril apresentou os maiores valores para pH, Na e C.E. Para manta nativa sem e com queima, as maiores concentrações foram para M.O., Ntotal, K, C.E., e adicionalmente para a mata sem queima H+Al. O sistema tradicional apresentou maiores concentrações para Na. A camada superior apresentou maiores valores para pH, M.O., Ntotal, K, CTC e CE em relação a camada 0,10-0,20 m. [Soil chemical properties in agrosylvopasture system at semi-arid northeastern Brazil with presence of fire]. Abstract: The analysis of soil chemical properties is an important tool to know the quality and soil deficiencies. The present study which was conducted at Embrapa Goats e Sheeps had as objective to evaluate soil fertility under Luvisols in agrosilvopasture system in a semi-arid zone. The following treatments were evaluated: agrosilvopasture, burnt silvopasture, non-burnt silvopasture, burnt native forest, non-burnt native forest and traditional. The experimental design was completely randomized block with split plots. The plots, the managements, the subplots and the depths (0-0.10 and 0.10-0.20 m) had five replications. There were significant difference in all treatments for all chemical attributes except Mg, Al and V. The treatments burnt and non-burnt silvopasture and agrosilvopasture showed high values for chemical attributes in relation to the traditional system. The agrosilvopasture environment had higher values for pH, Na and EC. As for burnt and non-burnt native vegetation, both had the highest concentration for MO, Ntotal, K, and EC. Besides, the non-burnt native vegetation had the highest concentration for H+Al. The traditional treatment had high concentration of Na. The top layer had higher values for pH, organic matter, total N, K, CEC and EC compared to 0.10-0.20 m layer
The Ratio of Ortho- to Para-H2 in Photodissociation Regions
We discuss the ratio of ortho- to para-H2 in photodissociation regions
(PDRs). We draw attention to an apparent confusion in the literature between
the ortho-to-para ratio of molecules in FUV-pumped vibrationally excited
states, and the H2 ortho-to-para abundance ratio. These ratios are not the same
because the process of FUV-pumping of fluorescent H2 emission in PDRs occurs
via optically thick absorption lines. Thus, gas with an equilibrium ratio of
ortho- to para-H2 equal to 3 will yield FUV-pumped vibrationally excited
ortho-to-para ratios smaller than 3, because the ortho-H2 pumping rates are
preferentially reduced by optical depth effects. Indeed, if the ortho and para
pumping lines are on the ``square root'' part of the curve-of-growth, then the
expected ratio of ortho and para vibrational line strengths is the square root
of 3, ~ 1.7, close to the typically observed value. Thus, contrary to what has
sometimes been stated in the literature, most previous measurements of the
ratio of ortho- to para-H2 in vibrationally excited states are entirely
consistent with a total ortho-to-para ratio of 3, the equilibrium value for
temperatures greater than 200 K. We present an analysis and several detailed
models which illustrate the relationship between the total ratios of ortho- to
para-H2 and the vibrationally excited ortho-to-para ratios in PDRs. Recent
Infrared Space Observatory (ISO) measurements of pure rotational and
vibrational H2 emissions from the PDR in the star-forming region S140 provide
strong observational support for our conclusions.Comment: 23 pages (including 5 figures), LaTeX, uses aaspp4.sty, accepted for
publication in Ap
Desempenho produtivo, composição corporal e parâmetros fisiológicos de pacu alimentado com níveis crescentes de fibra.
O objetivo deste trabalho foi avaliar os efeitos de teores de fibra bruta na dieta sobre o desempenho produtivo, composição centesimal da carcaça e parâmetros fsiológicos de juvenis de pacu. O experimento teve duração de 84 dias, e foram utilizados 360 juvenis de pacu, com peso médio de 23,97±0,59 g, distribuídos aleatóriamente em 30 tanques com 180 L de água, em delineamento inteiramente casualizado, com seis tratamentos (5, 7, 9, 11, 13 e 15% de fibra bruta) e cinco repetições. Dietas com altos teores de fibra (11, 13 e 15%) resultaram em piores taxas de ganho de peso, conversão alimentar e crescimento específco, além de menor efciência proteica e consumo de ração. A composição da carcaça dos animais foi alterada pelo aumento do teor de fibra das dietas. Os teores de proteína e cinza tiveram aumento com o incremento nos teores de fibra. O metabolismo foi alterado com o emprego de teores crescentes de fibra, o que resultou em pequena elevação do colesterol plasmático. Teores de fibra bruta de até 9% não tiveram efeitos negativos no metabolismo; entretanto, teores acima de 11% reduziram o crescimento dos peixes
Infrared scintillation yield in gaseous and liquid argon
The study of primary and secondary scintillations in noble gases and liquids
is of paramount importance to rare-event experiments using noble gas media. In
the present work, the scintillation yield in gaseous and liquid Ar has for the
first time been measured in the near infrared (NIR) and visible region, both
for primary and secondary (proportional) scintillations, using Geiger-mode
avalanche photodiodes (G-APDs) and pulsed X-ray irradiation. The primary
scintillation yield of the fast component was measured to be 17000 photon/MeV
in gaseous Ar in the NIR, in the range of 690-1000 nm, and 510 photon/MeV in
liquid Ar, in the range of 400-1000 nm. Proportional NIR scintillations
(electroluminescence) in gaseous Ar have been also observed; their
amplification parameter at 163 K was measured to be 13 photons per drifting
electron per kV. Possible applications of NIR scintillations in high energy
physics experiments are discussed.Comment: 6 pages, 5 figures. Submitted to Europhysics Letter. Revised Figs. 3
and
Chance long-distance or human-mediated dispersal? How Acacia s.l. farnesiana attained its pan-tropical distribution
Acacia s.l. farnesiana, which originates from Mesoamerica, is the most widely distributed Acacia s.l. species across the tropics. It is assumed that the plant was transferred across the Atlantic to southern Europe by Spanish explorers, and then spread across the Old World tropics through a combination of chance long-distance and human-mediated dispersal. Our study uses genetic analysis and information from historical sources to test the relative roles of chance and human-mediated dispersal in its distribution. The results confirm the Mesoamerican origins of the plant and show three patterns of human- mediated dispersal. Samples from Spain showed greater genetic diversity than those from other Old World tropics, suggesting more instances of transatlantic introductions from the Americas to that country than to other parts of Africa and Asia. Individuals from the Philippines matched a population from South Central Mexico and were likely to have been direct, trans-Pacific introductions. Australian samples were genetically unique, indicating that the arrival of the species in the continent was independent of these European colonial activities. This suggests the possibility of pre-European human- mediated dispersal across the Pacific Ocean. These significant findings raise new questions for biogeographic studies that assume chance or transoceanic dispersal 2 for disjunct plant distributions
3D Position Sensitive XeTPC for Dark Matter Search
The technique to realize 3D position sensitivity in a two-phase xenon time
projection chamber (XeTPC) for dark matter search is described. Results from a
prototype detector (XENON3) are presented.Comment: Presented at the 7th UCLA Symposium on "Sources and Detection of Dark
Matter and Dark Energy in the Universe
Classifying the biodiversity of the Great Barrier Reef World Heritage Area for the classification phase of the representative areas program
This technical report outlines the methods that the Great Barrier Reef Marine Park Authority
used to classify the biodiversity of the marine environs of the Great Barrier Reef World Heritage
Area for the Representative Areas Program. Classification was the first step in the multiphase
Representative Areas Program that eventuated in a new network of no-take areas, free from
extractive activities, in the Great Barrier Reef Marine Park
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