Astrophysical Journal Supplement Series最新文献

We present the results of a search for EMP, CEMP, and cataclysmic variable stars using a new exploration tool based on linked scatter plots (LSPs). Our approach is especially designed to work with very large spectrum data sets such as the SDSS, LAMOST, RAVE, and Gaia data sets and can be applied to stellar, galaxy, and quasar spectra. As a demonstration, we conduct a search for EMP, CEMP, and cataclysmic variable stars in the SDSS DR10 data set. We first created a 3326-dimensional phase space containing nearly 2 billion measures of the strengths of over 1600 spectral features in 569,738 SDSS stars. These measures capture essentially all the stellar atomic and molecular species visible at the resolution of SDSS spectra. We show how LSPs can be used to quickly isolate and examine interesting portions of this phase space. To illustrate, we use LSPs coupled with cuts in selected portions of phase space to extract EMP stars, C-rich EMP stars, and CV stars. We present identifications for 59 previously unrecognized candidate EMP stars and 11 previously unrecognized candidate CEMP stars. We also call attention to 2 candidate He II emission CV stars found by the LSP approach that have not yet been discussed in the literature.

New emission branching fraction (BF) measurements for 183 lines of the second spectrum of chromium (Cr II) and new radiative lifetime measurements from laser-induced fluorescence for 8 levels of Cr⁺ are reported. The goals of this study are to improve transition probability measurements in Cr II and reconcile solar and stellar Cr abundance values based on Cr I and Cr II lines. Eighteen spectra from three Fourier Transform Spectrometers supplemented with ultraviolet spectra from a high-resolution echelle spectrometer are used in the BF measurements. Radiative lifetimes from this study and earlier publications are used to convert the BFs into absolute transition probabilities. These new laboratory data are applied to determine the Cr abundance log ε in the Sun and metal-poor star HD 84937. The mean result in the Sun is 〈logε (Cr II)〉 = 5.624±0.009 compared to 〈logε(Cr I)〉 = 5.644 ± 0.006 on a scale with the hydrogen abundance log ε(H) = 12 and with the uncertainty representing only line-to-line scatter. A Saha (ionization balance) test on the photosphere of HD 84937 is also performed, yielding 〈logε(Cr II)〉 = 3.417 ± 0.006 and 〈log ε(Cr I, lower level excitation potential E. P. >30 eV)〉 = 3.3743±30.011 for this dwarf star. We find a correlation of Cr with the iron-peak element Ti, suggesting an associated nucleosynthetic production. Four iron-peak elements (Cr along with Ti, V, and Sc) appear to have a similar (or correlated) production history-other iron-peak elements appear not to be associated with Cr.

Rhythmic events in female reproductive physiology, including ovulation, are tightly controlled by the circadian timing system. The molecular clock, a feedback loop oscillator of clock gene transcription factors, dictates rhythms of gene expression in the hypothalamo-pituitary-ovarian axis. Circadian disruption due to environmental factors (eg, shift work) or genetic manipulation of the clock has negative impacts on fertility. Although the central pacemaker in the suprachiasmatic nucleus classically regulates the timing of ovulation, we have shown that this rhythm also depends on phasic sensitivity to LH. We hypothesized that this rhythm relies on clock function in a specific cellular compartment of the ovarian follicle. To test this hypothesis we generated mice with deletion of the Bmal1 locus in ovarian granulosa cells (GCs) (Granulosa Cell Bmal1 KO; GCKO) or theca cells (TCs) (Theca Cell Bmal1 KO; TCKO). Reproductive cycles, preovulatory LH secretion, ovarian morphology and behavior were not grossly altered in GCKO or TCKO mice. We detected phasic sensitivity to LH in wild-type littermate control (LC) and GCKO mice but not TCKO mice. This decline in sensitivity to LH is coincident with impaired fertility and altered patterns of LH receptor (Lhcgr) mRNA abundance in the ovary of TCKO mice. These data suggest that the TC is a pacemaker that contributes to the timing and amplitude of ovulation by modulating phasic sensitivity to LH. The TC clock may play a critical role in circadian disruption-mediated reproductive pathology and could be a target for chronobiotic management of infertility due to environmental circadian disruption and/or hormone-dependent reprogramming in women.

Background: Several interventions have been developed to promote informed consent for participants in clinical trials. However, many of these interventions focus on the content and structure of information (e.g. enhanced information or changes to the presentation format) rather than the process of decision making. Patient decision aids support a decision making process about medical options. Decision aids support the decision process by providing information about available options and their associated outcomes, alongside information that enables patients to consider what value they place on particular outcomes, and provide structured guidance on steps of decision making. They have been shown to be effective for treatment and screening decisions but evidence on their effectiveness in the context of informed consent for clinical trials has not been synthesised.

Objectives: To assess the effectiveness of decision aids for clinical trial informed consent compared to no intervention, standard information (i.e. usual practice) or an alternative intervention on the decision making process.

Search methods: We searched the following databases and to March 2015: Cochrane Central Register of Controlled Trials (CENTRAL), The Cochrane Library; MEDLINE (OvidSP) (from 1950); EMBASE (OvidSP) (from 1980); PsycINFO (OvidSP) (from 1806); ASSIA (ProQuest) (from 1987); WHO International Clinical Trials Registry Platform (ICTRP) (http://apps.who.int/trialsearch/); ClinicalTrials.gov; ISRCTN Register (http://www.controlled-trials.com/isrctn/). We also searched reference lists of included studies and relevant reviews. We contacted study authors and other experts. There were no language restrictions.

Selection criteria: We included randomised and quasi-randomised controlled trials comparing decision aids in the informed consent process for clinical trials alone, or in conjunction with standard information (such as written or verbal) or alongside alternative interventions (e.g. paper-based versus web-based decision aids). Included trials involved potential trial participants, or their guardians, being asked to consider participating in a real or hypothetical clinical trial.

Data collection and analysis: At least two authors independently assessed studies for inclusion, extracted reported data and assessed risk of bias. Findings were pooled where appropriate. We used GRADE to assess the quality of the evidence for each outcome.

Main results: We identified one study (290 randomised participants) that investigated the effectiveness of decision aids compared to standard information in the informed consent process for clinical trials. This study reported two separate decision aid randomised controlled trials (RCTs). The decision aid trials were nested within two different parent trials focusing on breast cancer in postmenopausal women. One tri