Dynamical study of the hyperextended scalar-tensor theory in the empty Bianchi type I model

The dynamics of the hyperextended scalar-tensor theory in the empty Bianchi type I model is investigated. We describe a method giving the sign of the first and second derivatives of the metric functions whatever the coupling function. Hence, we can predict if a theory gives birth to expanding, contracting, bouncing or inflationary cosmology. The dynamics of a string inspired theory without antisymetric field strength is analysed. Some exact solutions are found.Comment: 18 pages, 3 figure

The Sources of Wage Variation: An Analysis Using Matched Employer-Employee Data

This paper estimates a wage equation that includes worker- and firm fixed effects simultaneously, using a longitudinal matched employer-employee dataset covering virtually all Portuguese employees over a little more than two-decades. The exercise is performed under optimal conditions by using (a) data covering the whole population of employees and (b) adequate econometric methods and algorithms. The variation in log real hourly wages is then decomposed into six different components related to worker and firm characteristics (either observed or unobserved) and a residual component. It is found that worker heterogeneity is the most important source of wage variation (46.2 percent), due in roughly equal parts to the unobserved component (24.2 percent) and the observed component (22 percent). Firm effects are less important overall (29.6%), although firms’ observed characteristics do play an important role (14.8) in explaining wage differentials.

An Integrated Approach for Characterizing Aerosol Climate Impacts and Environmental Interactions

Aerosols exert myriad influences on the earth's environment and climate, and on human health. The complexity of aerosol-related processes requires that information gathered to improve our understanding of climate change must originate from multiple sources, and that effective strategies for data integration need to be established. While a vast array of observed and modeled data are becoming available, the aerosol research community currently lacks the necessary tools and infrastructure to reap maximum scientific benefit from these data. Spatial and temporal sampling differences among a diverse set of sensors, nonuniform data qualities, aerosol mesoscale variabilities, and difficulties in separating cloud effects are some of the challenges that need to be addressed. Maximizing the long-term benefit from these data also requires maintaining consistently well-understood accuracies as measurement approaches evolve and improve. Achieving a comprehensive understanding of how aerosol physical, chemical, and radiative processes impact the earth system can be achieved only through a multidisciplinary, inter-agency, and international initiative capable of dealing with these issues. A systematic approach, capitalizing on modern measurement and modeling techniques, geospatial statistics methodologies, and high-performance information technologies, can provide the necessary machinery to support this objective. We outline a framework for integrating and interpreting observations and models, and establishing an accurate, consistent, and cohesive long-term record, following a strategy whereby information and tools of progressively greater sophistication are incorporated as problems of increasing complexity are tackled. This concept is named the Progressive Aerosol Retrieval and Assimilation Global Observing Network (PARAGON). To encompass the breadth of the effort required, we present a set of recommendations dealing with data interoperability; measurement and model integration; multisensor synergy; data summarization and mining; model evaluation; calibration and validation; augmentation of surface and in situ measurements; advances in passive and active remote sensing; and design of satellite missions. Without an initiative of this nature, the scientific and policy communities will continue to struggle with understanding the quantitative impact of complex aerosol processes on regional and global climate change and air quality

TrES-2: The First Transiting Planet in the Kepler Field

We announce the discovery of the second transiting hot Jupiter discovered by the Trans-atlantic Exoplanet Survey. The planet, which we dub TrES-2, orbits the nearby star GSC 03549-02811 every 2.47063 days. From high-resolution spectra, we determine that the star has T_eff = 5960 +/- 100 K and log(g) = 4.4 +/- 0.2, implying a spectral type of G0V and a mass of 1.08 +0.11/-0.05 M_sun. High-precision radial-velocity measurements confirm a sinusoidal variation with the period and phase predicted by the photometry, and rule out the presence of line-bisector variations that would indicate that the spectroscopic orbit is spurious. We estimate a planetary mass of 1.28 +0.09/-0.04 M_Jup. We model B, r, R, and I photometric timeseries of the 1.4%-deep transits and find a planetary radius of 1.24 +0.09/-0.06 R_Jup. This planet lies within the field of view of the NASA Kepler mission, ensuring that hundreds of upcoming transits will be monitored with exquisite precision and permitting a host of unprecedented investigations.Comment: Accepted for publication in ApJL. 15 pages, 2 figure

LAVA: An Open-Source Approach To Designing LAMP (Loop-Mediated Isothermal Amplification) DNA Signatures

<p>Abstract</p> <p>Background</p> <p>We developed an extendable open-source Loop-mediated isothermal AMPlification (LAMP) signature design program called LAVA (LAMP Assay Versatile Analysis). LAVA was created in response to limitations of existing LAMP signature programs.</p> <p>Results</p> <p>LAVA identifies combinations of six primer regions for basic LAMP signatures, or combinations of eight primer regions for LAMP signatures with loop primers, which can be used as LAMP signatures. The identified primers are conserved among target organism sequences. Primer combinations are optimized based on lengths, melting temperatures, and spacing among primer sites. We compare LAMP signature candidates for <it>Staphylococcus aureus </it>created both by LAVA and by PrimerExplorer. We also include signatures from a sample run targeting all strains of <it>Mycobacterium tuberculosis</it>.</p> <p>Conclusions</p> <p>We have designed and demonstrated new software for identifying signature candidates appropriate for LAMP assays. The software is available for download at <url>http://lava-dna.googlecode.com/</url>.</p

Improving Stellar and Planetary Parameters of Transiting Planet Systems: The Case of TrES-2

We report on a spectroscopic determination of the atmospheric parameters and chemical abundance of the parent star of the recently discovered transiting planet TrES-2. A detailed LTE analysis of a set of Fe I and Fe II lines from our Keck spectra yields T_(eff) = 5850 ± 50 K, log g = 4.4 ± 0.1, and [Fe/H] = -0.15 ± 0.10. Several independent checks (e.g., additional spectroscopy, line-depth ratios) confirm the reliability of our spectroscopic T_(eff) estimate. The mass and radius of the star, needed to determine the properties of the planet, are traditionally inferred by comparison with stellar evolution models using T_(eff) and some measure of the stellar luminosity, such as the spectroscopic surface gravity. We apply here a new method in which we use instead of log g the normalized separation a/R_* (related to the stellar density), directly measurabele from the light curves of transiting planets with much greater precision. With the a/R_* value from the light-curve analysis of Holman and coworkers and our T_(eff) estimate, we obtain M_* = 0.980 ± 0.062 M_☉ and R_* = 1.000^(+0.036)_(-0.033) R_☉, and an evolutionary age of 5.1^(+2.7)_(-2.3) Gyr, in good agreement with other constraints (Ca II H and K line cores, lithium abundance, and rotation). The new stellar parameters yield improved values for the planetary mass and radius of M_p = 1.198 ± 0.053 M_J and R_p = 1.220^(+0.045)_(-0.042) R_J, confirming that TrES-2 is the most massive among the currently known nearby (d ≲ 300 pc) transiting hot Jupiters. The surface gravity of the planet, log g_p = 3.299 ± 0.016, can be derived independently of the knowledge of the stellar parameters (i.e., directly from observations), and with a very high precision rivaling that of the best known double-lined eclipsing binaries

BeppoSAX-WFC monitoring of the Galactic Center region

We review the results obtained with the Galactic center campaigns of the BeppoSAX Wide Field X-ray Cameras (WFCs). This pertains to the study of luminous low-mass X-ray binaries (LMXBs). When pointed at the Galactic center, the WFC field of view contains more than half of the Galactic LMXB population. The results exemplify the excellent WFC capability to detect brief X-ray transients. Firstly, the WFCs expanded the known population of Galactic thermonuclear X-ray bursters by 50%. At least half of all LMXBs are now established to burst and, thus, to contain a neutron star as compact accretor rather than a black hole candidate. We provide a complete list of all 76 currently known bursters, including the new case 1RXS J170854.4-321857. Secondly, the WFCs have uncovered a population of weak transients with peak luminosities up to ~10^37 erg/s and durations from days to weeks. One is the first accretion-powered millisecond pulsar SAX J1808.4-3658. Thirdly, the WFCs contributed considerably towards establishing that nearly all (12 out of 13) luminous low-mass X-ray binaries in Galactic globular clusters contain neutron stars rather than black holes. Thus, the neutron star to black hole ratio in clusters differs from that in the Galactic disk at a marginal confidence level of 97%.Comment: 10 pages 6 figures, to appear in Proc. "The Restless High-Energy Universe" (2nd BeppoSAX Symposium), eds. E.P.J. van den Heuvel, J.J.M. in 't Zand & R.A.M.J. Wijers, Nucl. Instrum. Meth. B Suppl. Se

Anti-inflammatory effects of a casein hydrolysate and its peptide-enriched fractions on TNFα-challenged Caco-2 cells and LPS-challenged porcine colonic explants

Bioactive milk peptides are reported to illicit a range of physiological benefits and have been proposed as potential functional food ingredients. The objective of this study was to characterize the anti-inflammatory properties of sodium caseinate (NaCAS), its enzyme hydrolysate (EH) and peptide-enriched fractions (5 kDa retentate [R], 1 kDaR and 1 kDa permeate [P]), both in vitro using a Caco-2 cell line, and also ex vivo using a porcine colonic tissue explant system. Caco-2 cells were stimulated with tumour necrosis factor alpha (TNFα) and co-treated with casein hydrolysates for 24 h. Following this, interleukin (IL)-8 concentrations in the supernatant were measured using enzyme-linked immunosorbent assay. Porcine colonic tissue was stimulated with lipopolysaccharide and co-treated with casein hydrolysates for 3 h. The expression of a panel of inflammatory cytokines was measured using qPCR. While dexamethasone reduced the IL-8 concentration by 41.6%, the 1 kDaR and 1 kDaP fractions reduced IL-8 by 68.7% and 66.1%, respectively, relative to TNFα-stimulated Caco-2 cells (P < 0.05). In the ex vivo system, only the 1 kDaR fraction elicited a decrease in IL1-α, IL1-β, IL-8, TGF-β and IL-10 expression (P < 0.05). This study provides evidence that the bioactive peptides present in the 1 kDaR fraction of the NaCAS hydrolysate possess anti-inflammatory properties in vitro and ex vivo. Further in vivo analysis of the anti-inflammatory properties of the 1 kDaR is proposed

Tolvaptan in ADPKD Patients With Very Low Kidney Function

Introduction: Tolvaptan slowed estimated glomerular filtration rate (eGFR) decline in subjects with autosomal dominant polycystic kidney disease (ADPKD) in TEMPO 3:4 and REPRISE trials. Tolvaptan effects in subjects with eGFR 15 to 24 ml/min per 1.73 m2 were not investigated. This post hoc analysis retrospectively investigated eGFR decline in REPRISE versus an open-label, phase 3b extension trial (open-label extension [OLE] NCT02251275) in subjects who received placebo in REPRISE and tolvaptan in OLE with eGFR 15 to 24 and 25 to 29 ml/min per 1.73 m2, respectively. Methods: One data subset comprised subjects with OLE baseline eGFR 15 to 29 ml/min per 1.73 m2 who had received placebo in REPRISE and began tolvaptan in OLE. The second comprised subjects who had received tolvaptan in REPRISE and were matched to REPRISE placebo-treated subjects for REPRISE baseline characteristics. Annualized eGFR slopes in REPRISE versus OLE were compared within the REPRISE placebo (i.e., placebo vs. tolvaptan treatment) and tolvaptan (i.e., 2 periods of tolvaptan treatment) subsets. Results: Mean annualized eGFR slopes (ml/min per 1.73 m2) during tolvaptan treatment in OLE versus placebo treatment in REPRISE were -3.4 versus -5.2 for subjects with OLE baseline eGFR 15 to 29 (difference, 1.7; P < 0.001), -3.6 versus -5.4 with baseline eGFR 15 to 24 (difference, 1.8; P < 0.001), and -3.3 versus -4.9 with baseline eGFR 25 to 29 (difference, 1.6; P < 0.001). In REPRISE tolvaptan subjects who continued tolvaptan in OLE, treatment effect was maintained (no difference between mean annualized eGFR slopes). Conclusion: Initiating or maintaining tolvaptan therapy significantly delayed eGFR decline in subjects with baseline eGFR 15 to 24 and 25 to 29 ml/min per 1.73 m2

A New Spectroscopic and Photometric Analysis of the Transiting Planet Systems TrES-3 and TrES-4

We report new spectroscopic and photometric observations of the parent stars of the recently discovered transiting planets TrES-3 and TrES-4. A detailed abundance analysis based on high-resolution spectra yields [Fe/H] = –0.19 ± 0.08, T_(eff) = 5650 ± 75 K, and log g = 4.4 ± 0.1 for TrES-3, and [Fe/H] = +0.14 ± 0.09, T_(eff) = 6200 ± 75 K, and log g = 4.0 ± 0.1 for TrES-4. The accuracy of the effective temperatures is supported by a number of independent consistency checks. The spectroscopic orbital solution for TrES-3 is improved with our new radial velocity measurements of that system, as are the light-curve parameters for both systems based on newly acquired photometry for TrES-3 and a reanalysis of existing photometry for TrES-4. We have redetermined the stellar parameters taking advantage of the strong constraint provided by the light curves in the form of the normalized separation a/R_* (related to the stellar density) in conjunction with our new temperatures and metallicities. The masses and radii we derive are M_* = 0.928^(+0.028)_(–0.048) M_⊙, R_* = 0.829^(+0.015)_(–0.022) R_⊙, and M_* = 1.404^(+0.066)_(–0.134) M_⊙, R_* = 1.846^(+0.096)_(–0.087) R_⊙ for TrES-3 and TrES-4, respectively. With these revised stellar parameters, we obtain improved values for the planetary masses and radii. We find M_p = 1.910^(+0.075)_(–0.080) M_(Jup), R_p = 1.336^(+0.031)_(–0.036) R_(Jup) for TrES-3, and M_p = 0.925 ± 0.082 M_(Jup), R_p = 1.783^(+0.093)_(–0.086) R_(Jup) for TrES-4. We confirm TrES-4 as the planet with the largest radius among the currently known transiting hot Jupiters