387 research outputs found
Non Equilibrium Electronic Distribution in Single Electron Devices
The electronic distribution in devices with sufficiently small diemnsions may
not be in thermal equilibrium with their surroundings. Systems where the
occupancies of electronic states are solely determined by tunneling processes
are analyzed. It is shown that the effective temperature of the device may be
higher, or lower, than that of its environment, depending on the applied
voltage and the energy dependence of the tunneling rates. The I-V
characteristics become asymmetric. Comparison with recent experiments is made
EGenBio : a data management system for evolutionary genomics and biodiversity
From The Third Annual Conference of the MidSouth Computational Biology and Bioinformatics Society Baton Rouge, Louisiana. 2–4 March, 2006.© 2006 Nahum et al; licensee BioMed Central Ltd.
This is an open access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0),
which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.EGenBio is a system for manipulation and filtering of large numbers of sequences,
integrating curated sequence alignments and phylogenetic trees, managing evolutionary analyses, and visualizing their output. EGenBio is organized into three conceptual divisions, Evolution, Genomics, and Biodiversity. The Genomics division includes tools for selecting pre-aligned sequences
from different genes and species, and for modifying and filtering these alignments for further
analysis. Species searches are handled through queries that can be modified based on a tree-based navigation system and saved. The Biodiversity division contains tools for analyzing individual sequences or sequence alignments, whereas the Evolution division contains tools involving phylogenetic trees. Alignments are annotated with analytical results and modification history using
our PRAED format. A miscellaneous Tools section and Help framework are also available. EGenBio was developed around our comparative genomic research and a prototype database of mtDNA genomes. It utilizes MySQL-relational databases and dynamic page generation, and calls numerous custom programs.This work was partly funded by the National Institutes of Health (R22/R33
Innovation and Development grant to David Pollock), the National Science
Foundation (CBM2/EPSCOR), and the State of Louisiana (Biological Computation and Visualization Center, Governor's iotechnology Initiative, and startup funds to David Pollock)
The Josephson heat interferometer
The Josephson effect represents perhaps the prototype of macroscopic phase
coherence and is at the basis of the most widespread interferometer, i.e., the
superconducting quantum interference device (SQUID). Yet, in analogy to
electric interference, Maki and Griffin predicted in 1965 that thermal current
flowing through a temperature-biased Josephson tunnel junction is a stationary
periodic function of the quantum phase difference between the superconductors.
The interplay between quasiparticles and Cooper pairs condensate is at the
origin of such phase-dependent heat current, and is unique to Josephson
junctions. In this scenario, a temperature-biased SQUID would allow heat
currents to interfere thus implementing the thermal version of the electric
Josephson interferometer. The dissipative character of heat flux makes this
coherent phenomenon not less extraordinary than its electric (non-dissipative)
counterpart. Albeit weird, this striking effect has never been demonstrated so
far. Here we report the first experimental realization of a heat
interferometer. We investigate heat exchange between two normal metal
electrodes kept at different temperatures and tunnel-coupled to each other
through a thermal `modulator' in the form of a DC-SQUID. Heat transport in the
system is found to be phase dependent, in agreement with the original
prediction. With our design the Josephson heat interferometer yields
magnetic-flux-dependent temperature oscillations of amplitude up to ~21 mK, and
provides a flux-to-temperature transfer coefficient exceeding ~ 60mK/Phi_0 at
235 mK [Phi_0 2* 10^(-15) Wb is the flux quantum]. Besides offering remarkable
insight into thermal transport in Josephson junctions, our results represent a
significant step toward phase-coherent mastering of heat in solid-state
nanocircuits, and pave the way to the design of novel-concept coherent
caloritronic devices.Comment: 4+ pages, 3 color figure
Optimal treatment allocations in space and time for on-line control of an emerging infectious disease
A key component in controlling the spread of an epidemic is deciding where, whenand to whom to apply an intervention.We develop a framework for using data to informthese decisionsin realtime.We formalize a treatment allocation strategy as a sequence of functions, oneper treatment period, that map up-to-date information on the spread of an infectious diseaseto a subset of locations where treatment should be allocated. An optimal allocation strategyoptimizes some cumulative outcome, e.g. the number of uninfected locations, the geographicfootprint of the disease or the cost of the epidemic. Estimation of an optimal allocation strategyfor an emerging infectious disease is challenging because spatial proximity induces interferencebetween locations, the number of possible allocations is exponential in the number oflocations, and because disease dynamics and intervention effectiveness are unknown at outbreak.We derive a Bayesian on-line estimator of the optimal allocation strategy that combinessimulation–optimization with Thompson sampling.The estimator proposed performs favourablyin simulation experiments. This work is motivated by and illustrated using data on the spread ofwhite nose syndrome, which is a highly fatal infectious disease devastating bat populations inNorth America
Composição centesimal, física e sensorial de carne de búfalos terminados em sistema tradicional e silvipastoril na Amazônia Oriental.
The aim of this study was to evaluate the physical and sensory characteristics of buffalo meat ended Traditional Systems and Silvopastoral. The experiments were performed in the Research Units Animal "Senator Álvaro Adolpho", SSP installed and "Dr. Philibert Camargo "(ST), belonging to Embrapa Amazônia Oriental, Belém-Pará. After this period the animals were slaughtered at a commercial packing plant and their carcasses were identified and cooled for 24 hours. The right side carcass was cut between the 12th and 13th ribs and removed the Longissimus dorsi (kebabs), for analysis of pH, texture and color lenses, weight loss by cooking, ability to retain water, determining the composition proximate and sensory evaluation. The experimental design was completely randomized, the data submitted to analysis of variance and means were compared by 't' test at 5%. There were no differences (p> 0.05) in chemical composition and physical analysis between meat derived from animals of the two systems. Among the evaluated sensory only the "aroma" differed statistically. It is still early to suggest the use of either system, just based on the quality of meat produced, should be considered also the environmental, social and economic
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