Decoherence and entropy of primordial fluctuations II. The entropy budget

We calculate the entropy of adiabatic perturbations associated with a truncation of the hierarchy of Green functions at the first non trivial level, i.e. in a self-consistent Gaussian approximation. We give the equation governing the entropy growth and discuss its phenomenology. It is parameterized by two model-dependent kernels. We then examine two particular inflationary models, one with isocurvature perturbations, the other with corrections due to loops of matter fields. In the first model the entropy grows rapidely, while in the second the state remains pure (at one loop).Comment: 28 page

Developing a Framework to Identify Local Business and Government Vulnerability to Sea-Level Rise: A Case Study of Coastal Virginia

In this paper we develop methods for identifying local business and government vulnerabilities to sea-level rise and the natural hazards associated with it. Unlike the fairly large literature on measuring social vulnerability to natural hazards, there are very few papers that discuss methods for measuring local business or local government vulnerability even though businesses and governments are also differentially affected natural hazards. Our goal is to create measures that are easily replicable using readily available data and that are easy to explain to local planners, policy makers, and citizens. We implement our measures of local business and government vulnerability for our study area, Coastal Virginia. We then combine those measures with a physical vulnerability measure to identify the areas in Coastal Virginia where planners and policy makers need to more closely examine the potential impacts of sea-level rise on their local businesses and government. While our methods are tailored to Coastal Virginia, they could be easily applied in other areas threatened by sea-level rise

South-West extension of the hard X-ray emission from the Coma cluster

We explore the morphology of hard (18-30 keV) X-ray emission from the Coma cluster of galaxies. We analyze a deep (1.1 Ms) observation of the Coma cluster with the ISGRI imager on board the \emph{INTEGRAL} satellite. We show that the source extension in the North-East to South-West (SW) direction ($\sim 17'$) significantly exceeds the size of the point spread function of ISGRI, and that the centroid of the image of the source in the 18-30 keV band is displaced in the SW direction compared to the centroid in the 1-10 keV band. To test the nature of the SW extension we fit the data assuming different models of source morphology. The best fit is achieved with a diffuse source of elliptical shape, although an acceptable fit can be achieved assuming an additional point source SW of the cluster core. In the case of an elliptical source, the direction of extension of the source coincides with the direction toward the subcluster falling onto the Coma cluster. If the SW excess is due to the presence of a point source with a hard spectrum, we show that there is no obvious X-ray counterpart for this additional source, and that the closest X-ray source is the quasar EXO 1256+281, which is located $6.1'$ from the centroid of the excess. The observed morphology of the hard X-ray emission clarifies the nature of the hard X-ray "excess" emission from the Coma cluster, which is due to the presence of an extended hard X-ray source SW of the cluster core.Comment: 7pages, 10 figure

Nutraceutical Intervention with Colostrum Replacer: Can We Reduce Disease Hazard, Ameliorate Disease Severity, and Improve Performance in Preweaned Dairy Calves?

The objective of this randomized clinical trial was to determine if an intervention with colostrum replacer (CR; Premolac Plus, Zinpro; 125 g/d fed for 3 d) or a placebo milk replacer (Cows Match, Land O\u27Lakes Inc.; 125 g/d for 3 d) following a triggered alarm could ameliorate disease bouts in dairy calves. The alarm was set to detect negative deviations of milk intake (20% reduction) or drinking speed (30% reduction) in relation to a calf\u27s 12-d rolling average feeding behavior. Calves were enrolled on this study (n = 42 CR, n = 42 placebo) when they triggered an alarm from d 14 to 50 on the feeder before weaning. Once calves were enrolled, calves received a bottle of either 125 g of CR or milk replacer mixed with 1 L of water for 3 d. Calves were enrolled on the automated milk feeder at age 4.0 ± 2.0 d (mean ± SD), were offered 10 L/d of the same milk replacer fed as a placebo, and had ad libitum access to calf starter measured by automated feeders. Weaning began at d 50, with 50% reduction of milk replacer across 14 d, and an additional 20% reduction for another 7 d before weaning at d 70. Calves were health scored from birth to 2 wk postweaning (88 ± 2.0 d of age) daily for bovine respiratory disease (BRD) and diarrhea, and were weighed and scored using lung ultrasonography twice weekly. A BRD score ≥ 5 and an area of consolidated lung ≥ 3.0 cm2 was considered BRD positive; diarrhea was defined as a watery fecal consistency that sifted through the bedding. The effect of CR on BRD and diarrhea likelihood were calculated with logistic models; the 7 d before and after an alarm were fixed effects, with milk intake as a covariate. A Cox proportional hazards model evaluated the effect of CR on the hazard of being positive for BRD and diarrhea following enrollment, with sex as a fixed effect in the diarrhea model. The effect of CR on average daily gain the week following intervention was evaluated with linear modeling with repeated measures, and birth date was a random effect. After intervention, placebo calves had 1.64 (95% CI: 1.11–2.43) times greater odds of having a BRD bout compared with CR calves for the 7 d following intervention. Moreover, placebo calves had 1.50 (95% CI: 1.11–2.08) times greater odds of having lobar lung consolidation in the 7 d after intervention than CR calves. No difference was found in the likelihood of diarrhea in the 7 d after intervention (odds ratio: 0.91; 95% CI: 0.71–1.16). However, placebo calves had a 2.38 (95% CI: 1.30–4.33) times greater hazard of incurring BRD in the 14 d after intervention. Average daily gain was not associated with an intervention with CR for the 7 d after intervention (placebo: 0.73 ± 0.07 kg/d; CR: 0.70 ± 0.08 kg/d; LSM ± SEM). These results suggest CR may reduce BRD likelihood but did not influence growth in calves offered high allowances of milk. Future research should examine which properties of CR ameliorate BRD in calves

Local Leaders in Random Networks

We consider local leaders in random uncorrelated networks, i.e. nodes whose degree is higher or equal than the degree of all of their neighbors. An analytical expression is found for the probability of a node of degree $k$ to be a local leader. This quantity is shown to exhibit a transition from a situation where high degree nodes are local leaders to a situation where they are not when the tail of the degree distribution behaves like the power-law $\sim k^{-\gamma_c}$ with $\gamma_c=3$. Theoretical results are verified by computer simulations and the importance of finite-size effects is discussed.Comment: 4 pages, 2 figure

Interacting damage models mapped onto Ising and percolation models

We introduce a class of damage models on regular lattices with isotropic interactions, as e.g. quasistatic fiber bundles. The system starts intact with a surface-energy threshold required to break any cell sampled from an uncorrelated quenched-disorder distribution. The evolution of this heterogeneous system is ruled by Griffith's principle which states that a cell breaks when the release in elastic energy in the system exceeds the surface-energy barrier necessary to break the cell. By direct integration over all possible realizations of the quenched disorder, we obtain the probability distribution of each damage configuration at any level of the imposed external deformation. We demonstrate an isomorphism between the distributions so obtained and standard generalized Ising models, in which the coupling constants and effective temperature in the Ising model are functions of the nature of the quenched-disorder distribution and the extent of accumulated damage. In particular, we show that damage models with global load sharing are isomorphic to standard percolation theory, that damage models with local load sharing rule are isomorphic to the standard Ising model, and draw consequences thereof for the universality class and behavior of the autocorrelation length of the breakdown transitions corresponding to these models. We also treat damage models having more general power-law interactions, and classify the breakdown process as a function of the power-law interaction exponent. Last, we also show that the probability distribution over configurations is a maximum of Shannon's entropy under some specific constraints related to the energetic balance of the fracture process, which firmly relates this type of quenched-disorder based damage model to standard statistical mechanics.Comment: 16 pages, 3 figure

Synchronous Behavior of Two Coupled Electronic Neurons

We report on experimental studies of synchronization phenomena in a pair of analog electronic neurons (ENs). The ENs were designed to reproduce the observed membrane voltage oscillations of isolated biological neurons from the stomatogastric ganglion of the California spiny lobster Panulirus interruptus. The ENs are simple analog circuits which integrate four dimensional differential equations representing fast and slow subcellular mechanisms that produce the characteristic regular/chaotic spiking-bursting behavior of these cells. In this paper we study their dynamical behavior as we couple them in the same configurations as we have done for their counterpart biological neurons. The interconnections we use for these neural oscillators are both direct electrical connections and excitatory and inhibitory chemical connections: each realized by analog circuitry and suggested by biological examples. We provide here quantitative evidence that the ENs and the biological neurons behave similarly when coupled in the same manner. They each display well defined bifurcations in their mutual synchronization and regularization. We report briefly on an experiment on coupled biological neurons and four dimensional ENs which provides further ground for testing the validity of our numerical and electronic models of individual neural behavior. Our experiments as a whole present interesting new examples of regularization and synchronization in coupled nonlinear oscillators.Comment: 26 pages, 10 figure

Modelization of flow electrification in a polymer melt

Flow electrification of polymer melts is an important side effect of polymer processing. The studies dealing with this phenomenon are seldom and most of the scientific work has been focused on flow electrification of aqueous and insulating Newtonian liquids. From that prior art it is well established that the flow electrification in Newtonian liquids is a consequence of the formation of an ionic double layer. Convection of this layer induces the electrification of the liquid at the outlet of the pipe. In those models, the key parameters governing the flow electrification are thus the intrinsic electrical properties of the polymer and the flow characteristics. In this work, we reconsider the assumptions made previously and we propose a new approach to modelise the flow electrification in the particular case of non-Newtonian polymer materials in laminar flow conditions. We establish that, a key parameter for the electrification quantification in the polymer melt is the shape of the velocity profile. Additionally, in some cases, we show that a slip velocity at the polymer/die wall interface must be considered to describe accurately the electrification. As a consequence, we deduce that the slip velocity at the interface can be calculated by measuring the electrification: this work gives an alternative manner to measure the slip velocity during polymer flow

Photonically enabled communication systems beyond 1000 GHz

This paper presents a review of the recent development and research work on InP devices and their associated systems to generate and detect signal beyond 1 THz. The potential of the technology and the remaining challenges are also discussed. The paper will present recent results on laser sources that could be used as the basis of the THz sources as well as a set of potential THz emitters such as the UTC photodiode which has already permitted up to 25 muW to be emitted at 1 THz

A Persistent High-Energy Flux from the Heart of the Milky Way : Integral's view of the Galactic Center

The Ibis/Isgri imager on Integral detected for the first time a hard X-ray source, IGR J17456-2901, located within 1' of Sgr A* over the energy range 20-100 keV. Here we present the results of a detailed analysis of ~7 Ms of Integral observations of the GC. With an effective exposure of 4.7 Ms we have obtained more stringent positional constraints on this HE source and constructed its spectrum in the range 20-400 keV. Furthermore, by combining the Isgri spectrum with the total X-ray spectrum corresponding to the same physical region around SgrA* from XMM data, and collected during part of the Integral observations, we constructed and present the first accurate wide band HE spectrum for the central arcmins of the Galaxy. Our complete analysis of the emission properties of IGR shows that it is faint but persistent with no variability above 3 sigma contrary to what was alluded to in our first paper. This result, in conjunction with the spectral characteristics of the X-ray emission from this region, suggests that the source is most likely not point-like but, rather, that it is a compact, yet diffuse, non-thermal emission region. The centroid of IGR is estimated to be R.A.=17h45m42.5, decl.=-28deg59'28'', offset by 1' from the radio position of Sgr A* and with a positional uncertainty of 1'. Its 20-400 keV luminosity at 8 kpc is L=5.4x10^35 erg/sec. Very recently, Hess detected of a source of ~TeV g-rays also located within 1' of Sgr A*. We present arguments in favor of an interpretation according to which the photons detected by Integral and Hess arise from the same compact region of diffuse emission near the central BH and that the supernova remnant Sgr A East could play an important role as a contributor of very HE g-rays to the overall spectrum from this region.Comment: 14 pages, 11 figures, Accepted for publication in Ap