The Major Fraction of Deoxyribonuclease Activity from Human Urinary Proteins Purification and Properties

Peer Reviewe

Bi2Te3Bi_2Te_3: Implications of the rhombohedral k-space texture on the evaluation of the in-plane/out-of-plane conductivity anisotropy

Different computational scheme for calculating surface integrals in anisotropic Brillouin zones are compared. The example of the transport distribution function (plasma frequency) of the thermoelectric Material \BiTe near the band edges will be discussed. The layered structure of the material together with the rhombohedral symmetry causes a strong anisotropy of the transport distribution function for the directions in the basal (in-plane) and perpendicular to the basal plane (out-of-plane). It is shown that a thorough reciprocal space integration is necessary to reproduce the in-plane/out-of-plane anisotropy. A quantitative comparison can be made at the band edges, where the transport anisotropy is given in terms of the anisotropic mass tensor.Comment: 7 pages, 6 figs., subm. to J. Phys. Cond. Ma

Energy Flow in Acoustic Black Holes

We present the results of an analysis of superradiant energy flow due to scalar fields incident on an acoustic black hole. In addition to providing independent confirmation of the recent results in [5], we determine in detail the profile of energy flow everywhere outside the horizon. We confirm explicitly that in a suitable frame the energy flow is inward at the horizon and outward at infinity, as expected on physical grounds.Comment: 8 pages, 9 figures, Comments added to discussion of energy flow and introductory section abbreviate

Thermoelectric transport in strained Si and Si/Ge heterostructures

The anisotropic thermoelectric transport properties of bulk silicon strained in [111]-direction were studied by detailed first-principles calculations focussing on a possible enhancement of the power factor. Electron as well as hole doping were examined in a broad doping and temperature range. At low temperature and low doping an enhancement of the power factor was obtained for compressive and tensile strain in the electron-doped case and for compressive strain in the hole-doped case. For the thermoelectrically more important high temperature and high doping regime a slight enhancement of the power factor was only found under small compressive strain with the power factor overall being robust against applied strain. To extend our findings the anisotropic thermoelectric transport of an [111]-oriented Si/Ge superlattice was investigated. Here, the cross-plane power factor under hole-doping was drastically suppressed due to quantum-well effects, while under electron-doping an enhanced power factor was found. With that, we state a figure of merit of ZT$=0.2$ and ZT$=1.4$ at T=\unit[300]{K} and T=\unit[900]{K} for the electron-doped [111]-oriented Si/Ge superlattice. All results are discussed in terms of band structure features

Tidal Evolution of Close-in Extra-Solar Planets

The distribution of eccentricities e of extra-solar planets with semi-major axes a > 0.2 AU is very uniform, and values for e are relatively large, averaging 0.3 and broadly distributed up to near 1. For a < 0.2 AU, eccentricities are much smaller (most e < 0.2), a characteristic widely attributed to damping by tides after the planets formed and the protoplanetary gas disk dissipated. Most previous estimates of the tidal damping considered the tides raised on the planets, but ignored the tides raised on the stars. Most also assumed specific values for the planets' poorly constrained tidal dissipation parameter Qp. Perhaps most important, in many studies, the strongly coupled evolution between e and a was ignored. We have now integrated the coupled tidal evolution equations for e and a over the estimated age of each planet, and confirmed that the distribution of initial e values of close-in planets matches that of the general population for reasonable Q values, with the best fits for stellar and planetary Q being ~10^5.5 and ~10^6.5, respectively. The accompanying evolution of a values shows most close-in planets had significantly larger a at the start of tidal migration. The earlier gas disk migration did not bring all planets to their current orbits. The current small values of a were only reached gradually due to tides over the lifetimes of the planets. These results may have important implications for planet formation models, atmospheric models of "hot Jupiters", and the success of transit surveys.Comment: accepted to Ap

Neutron star spin-kick velocity correlation effect on binary neutron star coalescence rates and spin-orbit misalignment of the components

We study the effect of the neutron star spin -- kick velocity alignment observed in young radio pulsars on the coalescence rate of binary neutron stars. Two scenarios of the neutron star formation are considered: when the kick is always present and when it is small or absent if a neutron star is formed in a binary system due to electron-capture degenerate core collapse. The effect is shown to be especially strong for large kick amplitudes and tight alignments, reducing the expected galactic rate of binary neutron star coalescences compared to calculations with randomly directed kicks. The spin-kick correlation also leads to a much narrower NS spin-orbit misalignment.Comment: 7 pages, 5 figures, accepted for publiction in MNRA

Global anomalies on Lorentzian space-times

We formulate an algebraic criterion for the presence of global anomalies on globally hyperbolic space-times in the framework of locally covariant field theory. We discuss some consequences and check that it reproduces the well-known global SU(2) anomaly in four space-time dimensions

Structure and Evolution of Giant Cells in Global Models of Solar Convection

The global scales of solar convection are studied through three-dimensional simulations of compressible convection carried out in spherical shells of rotating fluid which extend from the base of the convection zone to within 15 Mm of the photosphere. Such modelling at the highest spatial resolution to date allows study of distinctly turbulent convection, revealing that coherent downflow structures associated with giant cells continue to play a significant role in maintaining the strong differential rotation that is achieved. These giant cells at lower latitudes exhibit prograde propagation relative to the mean zonal flow, or differential rotation, that they establish, and retrograde propagation of more isotropic structures with vortical character at mid and high latitudes. The interstices of the downflow networks often possess strong and compact cyclonic flows. The evolving giant-cell downflow systems can be partly masked by the intense smaller scales of convection driven closer to the surface, yet they are likely to be detectable with the helioseismic probing that is now becoming available. Indeed, the meandering streams and varying cellular subsurface flows revealed by helioseismology must be sampling contributions from the giant cells, yet it is difficult to separate out these signals from those attributed to the faster horizontal flows of supergranulation. To aid in such detection, we use our simulations to describe how the properties of giant cells may be expected to vary with depth, how their patterns evolve in time, and analyze the statistical features of correlations within these complex flow fields.Comment: 22 pages, 16 figures (color figures are low res), uses emulateapj.cls Latex class file, Results shown during a Press release at the AAS meeting in June 2007. Submitted to Ap

Stellar models of evolved secondaries in CVs

In this paper we study the impact of chemically evolved secondaries on CV evolution. We find that when evolved secondaries are included a spread in the secondary mass-orbital period plane comparable to that seen in the data is produced for either the saturated prescription for magnetic braking or the unsaturated model commonly used for CVs. We argue that in order to explain this spread a considerable fraction of all CVs should have evolved stars as the secondaries. The evolved stars become fully convective at lower orbital periods. Therefore, even if there was an abrupt decrease in magnetic braking for fully convective stars (contrary to open cluster data) it would not be expected to produce a sharp break in the period distribution for CVs. We also explore recent proposed revisions to the angular momentum loss rate for single stars, and find that only modest increases over the saturated prescription are consistent with the overall observed spindown pattern. We compare predictions of our models with diagnostics of the mass accretion rate in WDs and find results intermediate between the saturated and the older braking prescription. Taken together these suggest that the angular momentum loss rate may be higher in CV secondaries than in single stars of the same rotation period, but is still significantly lower than in the traditional model. Alternative explanations for the CV period gap are discussed.Comment: 24 pages, 9 figures. Submitted to Ap

Deconvolution of complex G protein-coupled receptor signaling in live cells using dynamic mass redistribution measurements

Label-free biosensor technology based on dynamic mass redistribution (DMR) of cellular constituents promises to translate GPCR signaling into complex optical 'fingerprints' in real time in living cells. Here we present a strategy to map cellular mechanisms that define label-free responses, and we compare DMR technology with traditional second-messenger assays that are currently the state of the art in GPCR drug discovery. The holistic nature of DMR measurements enabled us to (i) probe GPCR functionality along all four G-protein signaling pathways, something presently beyond reach of most other assay platforms; (ii) dissect complex GPCR signaling patterns even in primary human cells with unprecedented accuracy; (iii) define heterotrimeric G proteins as triggers for the complex optical fingerprints; and (iv) disclose previously undetected features of GPCR behavior. Our results suggest that DMR technology will have a substantial impact on systems biology and systems pharmacology as well as for the discovery of drugs with novel mechanisms