Information entropy and nucleon correlations in nuclei

The information entropies in coordinate and momentum spaces and their sum ($S_r$, $S_k$, $S$) are evaluated for many nuclei using "experimental" densities or/and momentum distributions. The results are compared with the harmonic oscillator model and with the short-range correlated distributions. It is found that $S_r$ depends strongly on $\ln A$ and does not depend very much on the model. The behaviour of $S_k$ is opposite. The various cases we consider can be classified according to either the quantity of the experimental data we use or by the values of $S$, i.e., the increase of the quality of the density and of the momentum distributions leads to an increase of the values of $S$. In all cases, apart from the linear relation $S=a+b\ln A$, the linear relation $S=a_V+b_V \ln V$ also holds. V is the mean volume of the nucleus. If $S$ is considered as an ensemble entropy, a relation between $A$ or $V$ and the ensemble volume can be found. Finally, comparing different electron scattering experiments for the same nucleus, it is found that the larger the momentum transfer ranges, the larger the information entropy is. It is concluded that $S$ could be used to compare different experiments for the same nucleus and to choose the most reliable one.Comment: 14 pages, 4 figures, 2 table

Mutual information between geomagnetic indices and the solar wind as seen by WIND : implications for propagation time estimates

The determination of delay times of solar wind conditions at the sunward libration point to effects on Earth is investigated using mutual information. This measures the amount of information shared between two timeseries. We consider the mutual information content of solar wind observations, from WIND, and the geomagnetic indices. The success of five commonly used schemes for estimating interplanetary propagation times is examined. Propagation assuming a fixed plane normal at 45 degrees to the GSE x-axis (i.e. the Parker Spiral estimate) is found to give optimal mutual information. The mutual information depends on the point in space chosen as the target for the propagation estimate, and we find that it is maximized by choosing a point in the nightside rather than dayside magnetosphere. In addition, we employ recurrence plot analysis to visualize contributions to the mutual information, this suggests that it appears on timescales of hours rather than minutes

Liquid heat capacity in the approach from the solid state: anharmonic theory

Calculating liquid energy and heat capacity in general form is an open problem in condensed matter physics. We develop a recent approach to liquids from the solid state by accounting for the contribution of anharmonicity and thermal expansion to liquid energy and heat capacity. We subsequently compare theoretical predictions to the experiments results of 5 commonly discussed liquids, and find a good agreement with no free fitting parameters. We discuss and compare the proposed theory to previous approaches.Comment: 8 pages, 6 figure

Parity Violation in Aharonov-Bohm Systems: The Spontaneous Hall Effect

We show how macroscopic manifestations of $P$ (and $T$) symmetry breaking can arise in a simple system subject to Aharonov-Bohm interactions. Specifically, we study the conductivity of a gas of charged particles moving through a dilute array of flux tubes. The interaction of the electrons with the flux tubes is taken to be of a purely Aharonov-Bohm type. We find that the system exhibits a non-zero transverse conductivity, i.e., a spontaneous Hall effect. This is in contrast with the fact that the cross sections for both scattering and bremsstrahlung (soft photon emission) of a single electron from a flux tube are invariant under reflections. We argue that the asymmetry in the conductivity coefficients arises from many-body effects. On the other hand, the transverse conductivity has the same dependence on universal constants that appears in the Quantum Hall Effect, a result that we relate to the validity of the Mean Field approximation.Comment: 12 pages (4 figures available upon request), RevTex, EHU-FT-93/1

Human adipose stromal cell therapy improves survival and reduces renal inflammation and capillary rarefaction in acute kidney injury

Damage to endothelial cells contributes to acute kidney injury (AKI) by causing impaired perfusion, while the permanent loss of the capillary network following AKI has been suggested to promote chronic kidney disease. Therefore, strategies to protect renal vasculature may impact both short-term recovery and long-term functional preservation post-AKI. Human adipose stromal cells (hASCs) possess pro-angiogenic and anti-inflammatory properties and therefore have been tested as a therapeutic agent to treat ischaemic conditions. This study evaluated hASC potential to facilitate recovery from AKI with specific attention to capillary preservation and inflammation. Male Sprague Dawley rats were subjected to bilateral ischaemia/reperfusion and allowed to recover for either two or seven days. At the time of reperfusion, hASCs or vehicle was injected into the suprarenal abdominal aorta. hASC-treated rats had significantly greater survival compared to vehicle-treated rats (88.7% versus 69.3%). hASC treatment showed hastened recovery as demonstrated by lower creatinine levels at 48 hrs, while tubular damage was significantly reduced at 48 hrs. hASC treatment resulted in a significant decrease in total T cell and Th17 cell infiltration into injured kidneys at 2 days post-AKI, but an increase in accumulation of regulatory T cells. By day 7, hASC-treated rats showed significantly attenuated capillary rarefaction in the cortex (15% versus 5%) and outer medulla (36% versus 18%) compared to vehicle-treated rats as well as reduced accumulation of interstitial alpha-smooth muscle actin-positive myofibroblasts. These results suggest for the first time that hASCs improve recovery from I/R-induced injury by mechanisms that contribute to decrease in inflammation and preservation of peritubular capillaries

Slightly Non-Minimal Dark Matter in PAMELA and ATIC

We present a simple model in which dark matter couples to the standard model through a light scalar intermediary that is itself unstable. We find this model has several notable features, and allows a natural explanation for a surplus of positrons, but no surplus of anti-protons, as has been suggested by early data from PAMELA and ATIC. Moreover, this model yields a very small nucleon coupling, well below the direct detection limits. In this paper we explore the effect of this model in both the early universe and in the galaxy.Comment: 7 pages, 6 figures, v3: updated for new data, added discussion of Ferm

Bound states between dark matter particles and emission of gravitational radiation

Bound states of two weakly interactive massive particles are studied. It is assumed that the WIMPonium is formed due to the gravitational interaction, since the weak interaction can sometimes be repulsive. The lifetimes of the spontaneous emission of gravitational radiation and of the WIMPs annihilation into a pair of gravitons are computed, and are shown to be many orders of magnitude larger than the age of the universe.Comment: Accepted for publication in GER