5,383 research outputs found
Importância da avaliação microbiológica na qualidade e segurança dos alimentos.
Abordagem técnológica. Abordagem metodológica. Relevância econômica, social e ambiental. Referências bibliográficasbitstream/CNPAB-2010/27380/1/doc120.pd
Time-Reversal Symmetry Breaking and Decoherence in Chaotic Dirac Billiards
In this work, we perform a statistical study on Dirac Billiards in the
extreme quantum limit (a single open channel on the leads). Our numerical
analysis uses a large ensemble of random matrices and demonstrates the
preponderant role of dephasing mechanisms in such chaotic billiards. Physical
implementations of these billiards range from quantum dots of graphene to
topological insulators structures. We show, in particular, that the role of
finite crossover fields between the universal symmetries quickly leaves the
conductance to the asymptotic limit of unitary ensembles. Furthermore, we show
that the dephasing mechanisms strikingly lead Dirac billiards from the extreme
quantum regime to the semiclassical Gaussian regime
Glutamate induces autophagy via the two-pore channels in neural cells
NAADP (nicotinic acid adenine dinucleotide phosphate) has been proposed as a second messenger for glutamate in neuronal and glial cells via the activation of the lysosomal Ca2+ channels TPC1 and TPC2. However, the activities of glutamate that are mediated by NAADP remain unclear. In this study, we evaluated the effect of glutamate on autophagy in astrocytes at physiological, non-toxic concentration. We found that glutamate induces autophagy at similar extent as NAADP. By contrast, the NAADP antagonist NED-19 or SiRNA-mediated inhibition of TPC1/2 decreases autophagy induced by glutamate, confirming a role for NAADP in this pathway. The involvement of TPC1/2 in glutamate-induced autophagy was also confirmed in SHSY5Y neuroblastoma cells. Finally, we show that glutamate leads to a NAADP-dependent activation of AMPK, which is required for autophagy induction, while mTOR activity is not affected by this treatment. Taken together, our results indicate that glutamate stimulates autophagy via NAADP/TPC/AMPK axis, providing new insights of how Ca2+ signalling glutamate-mediated can control the cell metabolism in the central nervous system
On the dual equivalence between self-dual and Maxwell-Chern-Simons models with Lorentz symmetry breaking
In this paper, we use gauge embedding procedure and master action approach to
establish the equivalence between the self-dual and Maxwell-Chern-Simons models
with Lorentz symmetry breaking. As a result, new kinds of Lorentz-breaking
terms arise.Comment: 14 pages, minor corrections, version accepted to Physical Review
Freqüência de rinite atrofica em suínos de abate no estado de Santa Catarina.
Estrutura nasais em suínos. Lesões características de renite atrofica em suínos. Desvio do septo nasal
A Remark on Lorentz Violation at Finite Temperature
We investigate the radiatively induced Chern-Simons-like term in
four-dimensional field theory at finite temperature. The Chern-Simons-like term
is temperature dependent and breaks the Lorentz and CPT symmetries. We find
that this term remains undetermined although it can be found unambiguously in
different regularization schemes at finite temperature.Comment: To appear in JHEP, 8 pages, 1 eps figure, minor changes and
references adde
Staphylococcus aureus: importância para a saída pública e aspectos epidemiológicos.
Características do staphylococcus aureus. Intoxicação alimentar: aspectos epidemiólogicos.bitstream/CNPAB-2010/27353/1/doc114.pd
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