Abstract
We report on the properties of eclipsing binaries (EBs) from the Kepler mission with a newly developed photometric modelling code, which uses the light curve, spectral energy distribution of ...each binary, and stellar evolution models to infer stellar masses without the need for radial velocity (RV) measurements. We present solutions and posteriors to orbital and stellar parameters for 728 systems, forming the largest homogeneous catalogue of full Kepler binary parameter estimates to date. Using comparisons to published RV measurements, we demonstrate that the inferred properties (e.g. masses) are reliable for well-detached main-sequence (MS) binaries, which make up the majority of our sample. The fidelity of our inferred parameters degrades for a subset of systems not well described by input isochrones, such as short-period binaries that have undergone interactions, or binaries with post-MS components. Additionally, we identify 35 new systems which show evidence of eclipse timing variations, perhaps from apsidal motion due to binary tides or tertiary companions. We plan to subsequently use these models to search for and constrain the presence of circumbinary planets in Kepler EB systems.
SWISS-MODEL Repository (http://swissmodel.expasy.org/repository/) is a database of 3D protein structure models generated by the SWISS-MODEL homology-modelling pipeline. The aim of the SWISS-MODEL ...Repository is to provide access to an up-to-date collection of annotated 3D protein models generated by automated homology modelling for all sequences in Swiss-Prot and for relevant models organisms. Regular updates ensure that target coverage is complete, that models are built using the most recent sequence and template structure databases, and that improvements in the underlying modelling pipeline are fully utilised. As of September 2008, the database contains 3.4 million entries for 2.7 million different protein sequences from the UniProt database. SWISS-MODEL Repository allows the users to assess the quality of the models in the database, search for alternative template structures, and to build models interactively via SWISS-MODEL Workspace (http://swissmodel.expasy.org/workspace/). Annotation of models with functional information and cross-linking with other databases such as the Protein Model Portal (http://www.proteinmodelportal.org) of the PSI Structural Genomics Knowledge Base facilitates the navigation between protein sequence and structure resources.
A
bstract
We discuss some aspects of critical electric and magnetic fields in a field theory with holographic dual description. We extend the analysis of 1, which finds a critical electric field at ...which the Schwinger pair production barrier drops to zero, to the case of magnetic fields. We first find that, unlike ordinary weakly coupled theories, the magnetic field is not subject to any perturbative instability originating from the presence of a tachyonic ground state in the W-boson spectrum. This follows from the large value of the ’t Hooft coupling λ, which prevents the Zeeman interaction term to overcome the particle mass at high
B
. Consequently, we study the next possible B-field instability, i.e. monopole pair production, which is the S-dual version of the Schwinger effect. Also in this case a critical magnetic field is expected when the tunneling barrier drops to zero. These Schwinger-type criticalities are the holographic duals, in the bulk, to the fields
E
or
B
reaching the tension of F1 or D1 strings respectively. We then discuss how this effect is modified when electric and magnetic fields are present simultaneously and dyonic states in the spectrum can be pair produced by a generic
E
−
B
background. Finally, we analyze finite temperature effects on Schwinger criticalities, i.e. in the AdS-Schwarzshild black hole background.
Since the start of the Wide-angle Search for Planets (WASP) program, more than 160 transiting exoplanets have been discovered in the WASP data. In the past, possible transit-like events identified by ...the WASP pipeline have been vetted by human inspection to eliminate false alarms and obvious false positives. The goal of this paper is to assess the effectiveness of machine learning as a fast, automated, and reliable means of performing the same functions on ground-based wide-field transit-survey data without human intervention. To this end, we have created training and test data sets made up of stellar light curves showing a variety of signal types including planetary transits, eclipsing binaries, variable stars, and non-periodic signals. We use a combination of machine-learning methods including Random Forest Classifiers (RFCs) and convolutional neural networks (CNNs) to distinguish between the different types of signals. The final algorithms correctly identify planets in the test data ∼90 per cent of the time, although each method on its own has a significant fraction of false positives. We find that in practice, a combination of different methods offers the best approach to identifying the most promising exoplanet transit candidates in data from WASP, and by extension similar transit surveys.
Background
The brain oxytocin system is involved in a wide range of addictive behaviors, inhibiting prime- and cue-induced relapse in preclinical models of substance use disorders. Animal studies ...linked oxytocin’s effects on drug ingestion to modulation of neurotransmission in the nucleus accumbens (NAc). We set out to investigate whether oxytocin can modulate alcohol cue-induced functional connectivity between the brain reward system and cortical regions.
Methods
Fifteen male heavy social drinkers were enrolled in a randomized double-blind placebo-controlled cross-over functional magnetic resonance imaging study (fMRI) investigating the effect of 24 IU oxytocin on alcohol cue-modulated functional connectivity.
Results
Results of the functional connectivity analyses show that oxytocin application significantly reduced connectivity between the NAc and cuneus and thalamo-occipital connectivity, while enhancing connectivity between the paracingulate gyrus and precentral gyrus (tow-sided seed-level false discovery rate p
FDR
< 0.05). These effects were specific to the alcohol presentation and were absent during processing of neutral pictures. In addition, the NAc-cuneus connectivity significantly correlated with subjective alcohol cue-induced craving during the scanning session (r = 0.538, p = 0.024). Conclusion: Results provide initial evidence for condition-specific and significant attenuation of NAc connectivity by oxytocin in a sample of heavy social drinkers that was related to lower subjective alcohol craving during the fMRI task. Oxytocin-induced attenuation of NAc connectivity was specific to processing alcohol stimuli and might reflect an attenuation of alcohol-cue saliency by oxytocin that could lead to a reduction of the sensitivity towards the appetitive aspects of alcohol cues.
Disclosure
No significant relationships.
Objective: Infiltration by macrophages is a hallmark of obesity-related adipose tissue (AT) inflammation that is tightly linked to insulin resistance. Although CD11c+ AT macrophages (ATMs) have ...recently been shown to promote inflammation in obese mice, the knowledge on phenotype and function of different ATM populations is still very limited. This study aimed at identifying and characterizing ATM populations in obesity. Methods: Isolation of ATM populations defined by CD11c and mannose receptor (MR) expression and analysis of gene expression in high-fat diet-induced obese mice. Results: Obesity provoked a shift from a predominant MR+CD11c− population (‘MR-ATM’) to two MR− populations, namely MR−CD11c+ (‘CD11c-ATM’) and MR−CD11c− (double negative, ‘DN-ATM’). Although CD11c-ATMs were of a clear inflammatory M1 phenotype, DN-ATMs expressed few inflammatory mediators and highly expressed genes for alternative activation (M2) markers involved in tissue repair, such as arginase and YM1. In contrast, MR-ATMs marginally expressed M1 and M2 markers but highly expressed chemokines, including Mcp-1 (Ccl2) and Mcp-3 (Ccl7). Both CD11c-ATMs and DN-ATMs, but not MR-ATM, highly expressed a panel of chemokine receptors (namely Ccr2, Ccr5, Ccr3 and Cx3cr1), whereas the expression of Ccr7 and Ccr9 was selective for CD11c-ATMs and DN-ATMs, respectively. Notably, stressed adipocytes upregulated various chemokines capable of attracting CD11c-ATM and DN-ATM. Conclusion: This study identifies a novel ATM population with a putatively beneficial role in AT inflammation. This DN-ATM population could be attracted to the obese AT by similar chemokines such as inflammatory CD11c-ATM, on which only Ccr7 is uniquely expressed.
The source HD 172555 is a young A7V star surrounded by a debris disk with a gaseous component. Here, we present the detection of variable absorption features detected simultaneously in the Ca II K ...and H doublet lines (at λ3933 Å and λ3968 Å). We identified the presence of these absorption signatures at four different epochs in the 129 HARPS high-resolution spectra gathered between 2004 and 2011. These transient absorption features are most likely due to falling evaporating bodies (FEBs, or exocomets) that produce absorbing gas observed transiting in front of the central star. We also detect a stable Ca II absorption component at the star’s radial velocity. With no corresponding detection in the Na I line, the resulting very low upper limit for the Na I/Ca II ratio suggests that this absorption is due to circumstellar gas.
ABSTRACT We report the discovery of four short-period eclipsing systems in the Kepler light curves, consisting of an A-star primary and a low-mass white dwarf (WD) secondary (dA+WD)-KIC 4169521, ...KOI-3818, KIC 2851474, and KIC 9285587. The systems show BEaming, Ellipsoidal and Reflection (BEER) phase modulations together with primary and secondary eclipses. These add to the 6 Kepler and 18 WASP short-period eclipsing dA+WD binaries that were previously known. The light curves, together with follow-up spectroscopic observations, allow us to derive the masses, radii, and effective temperatures of the two components of the four systems. The orbital periods, of 1.17-3.82 days, and WD masses, of 0.19-0.22 M , are similar to those of the previously known systems. The WD radii of KOI-3818, KIC 2851474, and KIC 9285587 are 0.026, 0.035, and 0.026 R , respectively, the smallest WD radii derived so far for short-period eclipsing dA+WD binaries. These three binaries extend the previously known population to older systems with cooler and smaller WD secondaries. KOI-3818 displays evidence for a fast-rotating primary and a minute but significant eccentricity, ∼1.5 × 10−3. These features are probably the outcome of the mass-transfer process.
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