535 research outputs found
Swine Diets Utilizing Wheat
Previous trials have suggested that, when diets were supplemented at the same level and either corn or wheat was used in the same amount as the grain, pig gains were similar. However, pigs fed corn diets were more efficient in terms of both feed use and cost per pound of grain. Wheat diets supplemented at lower levels or assess the value of wheat\u27s higher protein level relative to corn and fed with or without supplemental lysine did not support satisfactory pig performance in terms of gain, feed efficiency or feed cost. Results of these trials suggested that an intermediate level of protein supplementation for wheat should be investigated. The trial reported here was designed with that objective
Wheat in Swine Finishing Rations
The objectives of the trial reported here were: 1. To compare the performance of pigs fed rations with the same proportions of grain and supplement but with the grain corn in one rations and wheat in another ration. 2. To assess the possible feeding value of wheat\u27s greater protein content by use of an all wheat ration in which there was a lower level of supplemental protein. 3. To assess the value of lysine in wheat rations by the effition of lysine to the same ration as used for comparison 2 (above)
Correlation entropy of synaptic input-output dynamics
The responses of synapses in the neocortex show highly stochastic and
nonlinear behavior. The microscopic dynamics underlying this behavior, and its
computational consequences during natural patterns of synaptic input, are not
explained by conventional macroscopic models of deterministic ensemble mean
dynamics. Here, we introduce the correlation entropy of the synaptic
input-output map as a measure of synaptic reliability which explicitly includes
the microscopic dynamics. Applying this to experimental data, we find that
cortical synapses show a low-dimensional chaos driven by the natural input
pattern.Comment: 7 pages, 6 Figures (7 figure files
Bures distance between two displaced thermal states
The Bures distance between two displaced thermal states and the corresponding
geometric quantities (statistical metric, volume element, scalar curvature) are
computed. Under nonunitary (dissipative) dynamics, the statistical distance
shows the same general features previously reported in the literature by
Braunstein and Milburn for two--state systems. The scalar curvature turns out
to have new interesting properties when compared to the curvature associated
with squeezed thermal states.Comment: 3 pages, RevTeX, no figure
Quantifying impacts of short-term plasticity on neuronal information transfer
Short-term changes in efficacy have been postulated to enhance the ability of
synapses to transmit information between neurons, and within neuronal networks.
Even at the level of connections between single neurons, direct confirmation of
this simple conjecture has proven elusive. By combining paired-cell recordings,
realistic synaptic modelling and information theory, we provide evidence that
short-term plasticity can not only improve, but also reduce information
transfer between neurons. We focus on a concrete example in rat neocortex, but
our results may generalise to other systems. When information is contained in
the timings of individual spikes, we find that facilitation, depression and
recovery affect information transmission in proportion to their impacts upon
the probability of neurotransmitter release. When information is instead
conveyed by mean spike rate only, the influences of short-term plasticity
critically depend on the range of spike frequencies that the target network can
distinguish (its effective dynamic range). Our results suggest that to
efficiently transmit information, the brain must match synaptic type, coding
strategy and network connectivity during development and behaviour.Comment: Accepted for publication in Phys Rev E. 42 pages in referee format, 9
figure
IDENTIFICATION OF NONLINEAR BEHAVIOR IN A COMPOSITE STRUCTURE WITH CORE-CRUSHING DAMAGE
ABSTRACT Many damage detection methods that are applied to composite structures rely on nonlinear features in the dynami
Fidelity for Multimode Thermal Squeezed States
In the theory of quantum transmission of information the concept of fidelity
plays a fundamental role. An important class of channels, which can be
experimentally realized in quantum optics, is that of Gaussian quantum
channels. In this work we present a general formula for fidelity in the case of
two arbitrary Gaussian states. From this formula one can get a previous result
(H. Scutaru, J. Phys. A: Mat. Gen {\bf 31}, 3659 (1998)), for the case of a
single mode; or, one can apply it to obtain a closed compact expression for
multimode thermal states.Comment: 5 pages, RevTex, submitted to Phys. Rev.
Broadband Transmission Spectroscopy of the super-Earth GJ 1214b suggests a Low Mean Molecular Weight Atmosphere
We used WIRCam on CFHT to observe four transits of the super-Earth GJ 1214b
in the near-infrared. For each transit we observed in two bands
nearly-simultaneously by rapidly switching the WIRCam filter wheel back and
forth for the duration of the observations. By combining all our J-band (~1.25
microns) observations we find a transit depth in this band of 1.338\pm0.013% -
a value consistent with the optical transit depth reported by Charbonneau and
collaborators. However, our best-fit combined Ks-band (~2.15 microns) transit
depth is deeper: 1.438\pm0.019%. Formally our Ks-band transits are deeper than
the J-band transits observed simultaneously by a factor of 1.072\pm0.018 - a
4-sigma discrepancy. The most straightforward explanation for our deeper
Ks-band depth is a spectral absorption feature from the limb of the atmosphere
of the planet; for the spectral absorption feature to be this prominent the
atmosphere of GJ 1214b must have a large scale height and a low mean molecular
weight. That is, it would have to be hydrogen/helium dominated and this planet
would be better described as a mini-Neptune. However, recently published
observations from 0.78 - 1.0 microns, by Bean and collaborators, show a lack of
spectral features and transit depths consistent with those obtained by
Charbonneau and collaborators. The most likely atmospheric composition for GJ
1214b that arises from combining all these observations is less clear; if the
atmosphere of GJ 1214b is hydrogen/helium dominated then it must have either a
haze layer that is obscuring transit depth differences at shorter wavelengths,
or significantly different spectral features than current models predict. Our
observations disfavour a water-world composition, but such a composition will
remain a possibility until observations reconfirm our deeper Ks-band transit
depth or detect features at other wavelengths. [Abridged]Comment: ApJ accepted. 12 pages, 6 figures, in EmulateApJ forma
There and back again: migration in freshwater fishes
Animal migration is an amazing phenomenon that has fascinated humans for long. Many freshwater fishes also show remarkable migrations, whereof the spectacular mass migrations of salmonids from the spawning streams are the most well known and well studied. However, recent studies have shown that migration occurs in a range of freshwater fish taxa from many different habitats. In this review we focus on the causes and consequences of migration in freshwater fishes. We start with an introduction of concepts and categories of migration, and then address the evolutionary causes that
drive individuals to make these migratory journeys. The basis for the decision of an individual fish to migrate or stay resident is an evaluation of the costs and benefits of different strategies to maximize its lifetime reproductive effort. We provide examples by discussing our own work on the causes behind seasonal migration in a cyprinid fish, roach (Rutilus rutilus (L., 1758)), within this framework. We then highlight different adaptations that allow fish to migrate over sometimes vast journeys across space, including capacity for orientation, osmoregulation, and efficient energy expenditure. Following this we consider the consequences of migration in freshwater fish from ecological, evolutionary, and conservation perspectives, and finally, we detail some of the recent developments in the methodologies used to collect data on fish migration and how these could be used in future research
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