Conductivity and the current-current correlation measure

We review various formulations of conductivity for one-particle Hamiltonians and relate them to the current-current correlation measure. We prove that the current-current correlation measure for random Schr\"odinger operators has a density at coincident energies provided the energy lies in a localization regime. The density vanishes at such energies and an upper bound on the rate of vanishing is computed. We also relate the current-current correlation measure to the localization length

The chemistry of bromine in the stratosphere: Influence of a new rate constant for the reaction BrO + HO2

The impact of new laboratory data for the reaction BrO + HO2 yields HOBr + O2 in the depletion of global stratospheric ozone has been estimated using a one-dimensional photochemical model taking into account the heterogeneous reaction on sulphate aerosols which converts N2O5 into HNO3. Assuring an aerosol loading 2 times as large as the 'background' and a reaction probability of 0.1 for the above heterogeneous reaction, the 6 fold increase in the measured rate constant for the reaction of BrO with HO2 increases the computed depletion of global ozone produced by 20 ppt of total bromine from 2.01 percent to 2.36 percent. The use of the higher rate constant increases the HOBr mixing ratio and makes the bromine partitioning and the ozone depletion very sensitive to the branching ratio of the potential channel forming HBr in the BrO + HO2 reaction

The atmospheres of the hot-Jupiters Kepler-5b and Kepler-6b observed during occultations with Warm-Spitzer and Kepler

This paper reports the detection and the measurements of occultations of the two transiting hot giant exoplanets Kepler-5b and Kepler-6b by their parent stars. The observations are obtained in the near infrared with Spitzer Space Telescope and at optical wavelengths by combining more than a year of Kepler photometry. The investigation consists of constraining the eccentricities of these systems and of obtaining broad band emergent spectra for individual planets. For both targets, the occultations are detected at 3 sigma level at each wavelength with mid-occultation times consistent with circular orbits. The brightness temperatures of these planets are deduced from the infrared observations and reach T=1930+/-100K and T=1660+/-120K for Kepler-5b and Kepler-6b respectively. We measure optical geometric albedos A_g in the Kepler bandpass and find A_g=0.12+/-0.04 for Kepler-5b and A_g=0.11+/-0.04 for Kepler-6b leading to an upper limit for the Bond albedo of A_B < 0.17 in both cases. The observations for both planets are best described by models for which most of the incident energy is redistributed on the dayside, with only less than 10% of the absorbed stellar flux redistributed to the night side of these planets. The data for Kepler-5b favor a model without a temperature inversion, whereas for Kepler-6b they do not allow distinguishing between models with and without inversion.Comment: 26 pages, 18 figures, 3 tables, submitted to Ap

Low False-Positive Rate of Kepler Candidates Estimated From A Combination Of Spitzer And Follow-Up Observations

(Abridged) NASA's Kepler mission has provided several thousand transiting planet candidates, yet only a small subset have been confirmed as true planets. Therefore, the most fundamental question about these candidates is the fraction of bona fide planets. Estimating the rate of false positives of the overall Kepler sample is necessary to derive the planet occurrence rate. We present the results from two large observational campaigns that were conducted with the Spitzer telescope during the the Kepler mission. These observations are dedicated to estimating the false positive rate (FPR) amongst the Kepler candidates. We select a sub-sample of 51 candidates, spanning wide ranges in stellar, orbital and planetary parameter space, and we observe their transits with Spitzer at 4.5 microns. We use these observations to measures the candidate's transit depths and infrared magnitudes. A bandpass-dependent depth alerts us to the potential presence of a blending star that could be the source of the observed eclipse: a false-positive scenario. For most of the candidates (85%), the transit depths measured with Kepler are consistent with the depths measured with Spitzer as expected for planetary objects, while we find that the most discrepant measurements are due to the presence of unresolved stars that dilute the photometry. The Spitzer constraints on their own yield FPRs between 5-40%, depending on the KOIs. By considering the population of the Kepler field stars, and by combining follow-up observations (imaging) when available, we find that the overall FPR of our sample is low. The measured upper limit on the FPR of our sample is 8.8% at a confidence level of 3 sigma. This observational result, which uses the achromatic property of planetary transit signals that is not investigated by the Kepler observations, provides an independent indication that Kepler's false positive rate is low.Comment: 33 pages, 16 figures, 3 tables; accepted for publication in ApJ on February 7, 201

Short report: Semi-quantitative scoring of an immunochromatographic test for circulating filarial antigen

The value of a semi-quantitative scoring of the filarial antigen test (Binax Now Filariasis card test, ICT) results was evaluated during a field survey in. the Republic of Congo. One hundred and thirty-four (134) of 774 tests (17.3%) were clearly positive and were scored 1, 2, or 3; and 11 (1.4%) had questionable results. Wuchereria bancrofti microfilariae (mf) were detected in 41 of those 133 individuals with an ICT test score 1 who also had a night blood smear; none of the 11 individuals with questionable ICT results harbored night mf. Cuzick's test showed a significant trend for higher microfilarial densities in groups with higher ICT scores (P < 0.001). The ICT scores were also significantly correlated with blood mf counts. Because filarial antigen levels provide an indication of adult worm infection intensity, our results suggest that semi-quantitative reading of the ICT may be useful for grading the intensity of filarial infections in individuals and populations

Subthalamic lesion or levodopa treatment rescues giant GABAergic currents of PINK1-deficient striatum

Cellular electrophysiological signatures of Parkinson's disease described in the pharmacological 6-hydroxydopamine (6-OHDA) animal models of Parkinson's disease include spontaneous repetitive giant GABAergic currents in a subpopulation of striatal medium spiny neurons (MSNs), and spontaneous rhythmic bursts of spikes generated by subthalamic nucleus (STN) neurons.Weinvestigated whether similar signatures are present in Pink1-/- mice, a genetic rodent model of the PARK6 variant of Parkinson's disease. Although 9- to 24-month-old Pink1-/-mice show reduced striatal dopamine content and release, and impaired spontaneous locomotion, the relevance of this model to Parkinson's disease has been questioned because mesencephalic dopaminergic neurons do not degenerate during the mouse lifespan. We show that 75% of the MSNs of 5- to 7-month-old Pink1-/- mice exhibit giant GABAergic currents, occurring either singly or in bursts (at 40 Hz), rather than the low-frequency (2 Hz), low-amplitude, tonic GABAergic drive common to wild-type MSNs of the same age. STN neurons from 5- to 7-month-old Pink1-/- mice spontaneously generated bursts of spikes instead of the control tonic drive. Chronic kainic acid lesion of the STN or chronic levodopa treatment reliably suppressed the giant GABAergic currents of MSNs after 1 month and replaced them with the control tonic activity. The similarity between the in vitro resting states of Pink1 MSNs and those of fully dopamine (DA)-depleted MSNs of 6-OHDA-treated mice, together with the beneficial effect of levodopa treatment, strongly suggest that dysfunction of mesencephalic dopaminergic neurons in Pink1-/-mice is more severe than expected. The beneficial effect of the STN lesion also suggests that pathological STN activity strongly influences striatal networks in Pink1-/- mic

Detailed Analysis of Nearby Bulgelike Dwarf Stars III. Alpha and Heavy-element abundances

The present sample of nearby bulgelike dwarf stars has kinematics and metallicities characteristic of a probable inner disk or bulge origin. Ages derived by using isochrones give 10-11 Gyr for these stars and metallicities are in the range -0.80< [Fe/H]< +0.40. We calculate stellar parameters from spectroscopic data, and chemical abundances of Mg, Si, Ca, Ti, La, Ba, Y, Zr and Eu are derived by using spectrum synthesis. We found that [alpha-elements/Fe] show different patterns depending on the element. Si, Ca and Ti-to-iron ratios decline smoothly for increasing metallicities, and follow essentially the disk pattern. O and Mg, products of massive supernovae, and also the r-process element Eu, are overabundant relative to disk stars, showing a steeper decline for metallicities [Fe/H] > -0.3 dex. [s-elements/Fe] roughly track the solar values with no apparent trend with metallicity for [Fe/H] < 0, showing subsolar values for the metal rich stars. Both kinematical and chemical properties of the bulgelike stars indicate a distinct identity of this population when compared to disk stars.Comment: 21 pages, 9 figures, to appear in Ap

Kepler-93b: A Terrestrial World Measured to within 120 km, and a Test Case for a New Spitzer Observing Mode

We present the characterization of the Kepler-93 exoplanetary system, based on three years of photometry gathered by the Kepler spacecraft. The duration and cadence of the Kepler observations, in tandem with the brightness of the star, enable unusually precise constraints on both the planet and its host. We conduct an asteroseismic analysis of the Kepler photometry and conclude that the star has an average density of 1.652+/-0.006 g/cm^3. Its mass of 0.911+/-0.033 M_Sun renders it one of the lowest-mass subjects of asteroseismic study. An analysis of the transit signature produced by the planet Kepler-93b, which appears with a period of 4.72673978+/-9.7x10^-7 days, returns a consistent but less precise measurement of the stellar density, 1.72+0.02-0.28 g/cm^3. The agreement of these two values lends credence to the planetary interpretation of the transit signal. The achromatic transit depth, as compared between Kepler and the Spitzer Space Telescope, supports the same conclusion. We observed seven transits of Kepler-93b with Spitzer, three of which we conducted in a new observing mode. The pointing strategy we employed to gather this subset of observations halved our uncertainty on the transit radius ratio R_p/R_star. We find, after folding together the stellar radius measurement of 0.919+/-0.011 R_Sun with the transit depth, a best-fit value for the planetary radius of 1.481+/-0.019 R_Earth. The uncertainty of 120 km on our measurement of the planet's size currently renders it one of the most precisely measured planetary radii outside of the Solar System. Together with the radius, the planetary mass of 3.8+/-1.5 M_Earth corresponds to a rocky density of 6.3+/-2.6 g/cm^3. After applying a prior on the plausible maximum densities of similarly-sized worlds between 1--1.5 R_Earth, we find that Kepler-93b possesses an average density within this group.Comment: 20 pages, 9 figures, accepted for publication in Ap

IVOA Recommendation: Observation Data Model Core Components and its Implementation in the Table Access Protocol Version 1.0

This document defines the core components of the Observation data model that are necessary to perform data discovery when querying data centers for observations of interest. It exposes use-cases to be carried out, explains the model and provides guidelines for its implementation as a data access service based on the Table Access Protocol (TAP). It aims at providing a simple model easy to understand and to implement by data providers that wish to publish their data into the Virtual Observatory. This interface integrates data modeling and data access aspects in a single service and is named ObsTAP. It will be referenced as such in the IVOA registries. There will be a separate document to cover the full Observation data model. In this document, the Observation Data Model Core Components (ObsCoreDM) defines the core components of queryable metadata required for global discovery of observational data. It is meant to allow a single query to be posed to TAP services at multiple sites to perform global data discovery without having to understand the details of the services present at each site. It defines a minimal set of basic metadata and thus allows for a reasonable cost of implementation by data providers. The combination of the ObsCoreDM with TAP is referred to as an ObsTAP service. As with most of the VO Data Models, ObsCoreDM makes use of STC, Utypes, Units and UCDs. The ObsCoreDM can be serialized as a VOTable. ObsCoreDM can make reference to more complete data models such as ObsProvDM (the Observation Provenance Data Model, to come), Characterisation DM, Spectrum DM or Simple Spectral Line Data Model (SSLDM).Comment: About the IVOA: http://www.ivoa.net; editors: Doug Tody, Alberto Micol, Daniel Durand, Mireille Louy

The SARS algorithm: detrending CoRoT light curves with Sysrem using simultaneous external parameters

Surveys for exoplanetary transits are usually limited not by photon noise but rather by the amount of red noise in their data. In particular, although the CoRoT spacebased survey data are being carefully scrutinized, significant new sources of systematic noises are still being discovered. Recently, a magnitude-dependant systematic effect was discovered in the CoRoT data by Mazeh & Guterman et al. and a phenomenological correction was proposed. Here we tie the observed effect a particular type of effect, and in the process generalize the popular Sysrem algorithm to include external parameters in a simultaneous solution with the unknown effects. We show that a post-processing scheme based on this algorithm performs well and indeed allows for the detection of new transit-like signals that were not previously detected.Comment: MNRAS accepted. 5 pages, 3 figure