bluuebunny/crossref_metadata_2025_split huggingface dataset:
Cosmic infrared background measurements and star formation history from Planck
Authors: Serra Paolo ,   on behalf of the Planck Collaboration
Published: July 2015

AbstractWe present new measurements of Cosmic Infrared Background (CIB) anisotropies using Planck. Combining HFI data with IRAS, the angular auto- and cross-frequency power spectrum is measured from 143 to 3000 GHz. After careful removal of the contaminants (cosmic microwave background anisotropies, Galactic dust and Sunyaev-Zeldovich emission), and a complete study of systematics, the CIB power spectrum is measured with unprecedented signal to noise ratio from angular multipoles ℓ ~ 150 to 2500. The interpretation based on the halo model is able to associate star-forming galaxies with dark matter halos and their subhalos, using a parametrized relation between the dust-processed infrared luminosity and (sub-)halo mass, and it allows to simultaneously fit all auto- and cross- power spectra very well. We find that the star formation history is well constrained up to redshifts around 2, and agrees with recent estimates of the obscured star-formation density using Spitzer and Herschel. However, at higher redshift, the accuracy of the star formation history measurement is strongly degraded by the uncertainty in the spectral energy distribution of CIB galaxies. We also find that the mean halo mass which is most efficient at hosting star formation is log(Meff/M⊙) = 12.6 and that CIB galaxies have warmer temperatures as redshift increases.
On spin scale-discretised wavelets on the sphere for the analysis of CMB polarisation
Authors: McEwen Jason D. , Büttner Martin , Leistedt Boris , Peiris Hiranya V. , Vandergheynst Pierre , Wiaux Yves 
Published: July 2015

AbstractA new spin wavelet transform on the sphere is proposed to analyse the polarisation of the cosmic microwave background (CMB), a spin ± 2 signal observed on the celestial sphere. The scalar directional scale-discretised wavelet transform on the sphere is extended to analyse signals of arbitrary spin. The resulting spin scale-discretised wavelet transform probes the directional intensity of spin signals. A procedure is presented using this new spin wavelet transform to recover E- and B-mode signals from partial-sky observations of CMB polarisation.
Data-mining Based Expert Platform for the Spectral Inspection
Authors: Tian Haijun , Xu Yang , Tu Yang , Zhang Yanxia , Zhao Yongheng , Lei Guohong , He Boliang , Cui Chenzhou , Chen Xuelei 
Published: July 2015

AbstractWe propose and preliminarily implement a data-mining based platform to assist experts to inspect the increasing amount of spectra with low signal to noise ratio (SNR) generated by large sky surveys. The platform includes three layers: data-mining layer, data-node layer and expert layer. It is similar to the GalaxyZoo project and it is VO-compatible. The preliminary experiment suggests that this platform can play an effective role in managing the spectra and assisting the experts to inspect a large number of spectra with low SNR.
Bayesian CMB foreground separation with a correlated log-normal model
Authors: Oppermann Niels , Enßlin Torsten A. 
Published: July 2015

AbstractThe extraction of foreground and CMB maps from multi-frequency observations relies mostly on the different frequency behavior of the different components. Existing Bayesian methods additionally make use of a Gaussian prior for the CMB whose correlation structure is described by an unknown angular power spectrum. We argue for the natural extension of this by using non-trivial priors also for the foreground components. Focusing on diffuse Galactic foregrounds, we propose a log-normal model including unknown spatial correlations within each component and cross-correlations between the different foreground components. We present case studies at low resolution that demonstrate the superior performance of this model when compared to an analysis with flat priors for all components.
Detecting Particle Dark Matter Signatures via Cross-Correlation of Gamma-Ray Anisotropies and Cosmic Shear
Authors: Camera Stefano 
Published: July 2015

AbstractSimilarly to gravitational lensing effects like cosmic shear, cosmological γ-ray emission too is to some extent a tracer of the distribution of dark matter (DM) in the Universe. Intervening DM structures source gravitational lensing distortions of distant galaxy images, and those same galaxies can emit γ rays, either because they host astrophysical sources, or directly by particle DM annihilations or decays occurring in the galactic halo. If such γ rays exhibit correlation with the cosmic shear signal, this will provide novel information on the composition of the extragalactic γ-ray background.
Transformed Auto-correlation
Authors: Zhou Jianfeng , Gao Yang 
Published: July 2015

AbstractA transformed auto-correlation method is presented here, where a received signal is transformed based on a priori reflecting model, and then the transformed signal is cross-correlated to its original one. If the model is correct, after transformation, the reflected signal will be coherent to the transmitted signal, with zero delay. A map of transformed auto-correlation function with zero delay can be generated in a given parametric space. The significant peaks in the map may indicate the possible reflectors nearby the central transmitter. The true values of the parameters of reflectors can be estimated at the same time.
Cross-correlation between cosmological and astrophysical datasets: the Planck and Herschel case
Authors: Bianchini Federico , Lapi Andrea 
Published: July 2015

AbstractWe present the first measurement of the correlation between the map of the CMB lensing potential derived from the Planck nominal mission data and z ≳ 1.5 galaxies detected by Herschel-ATLAS (H-ATLAS) survey covering about 550 deg2. We detect the cross-power spectrum with a significance of ∼ 8.5σ, ruling out the absence of correlation at 9σ. We check detection with a number of null tests. The amplitude of cross-correlation and the galaxy bias are estimated using joint analysis of the cross-power spectrum and the galaxy survey auto-spectrum, which allows to break degeneracy between these parameters. The estimated galaxy bias is consistent with previous estimates of the bias for the H-ATLAS data, while the cross-correlation amplitude is higher than expected for a ΛCDM model. The content of this work is to appear in a forthcoming paper Bianchini, et al. (2014).
Machine-learning in astronomy
Authors: Hobson Michael , Graff Philip , Feroz Farhan , Lasenby Anthony 
Published: July 2015

AbstractMachine-learning methods may be used to perform many tasks required in the analysis of astronomical data, including: data description and interpretation, pattern recognition, prediction, classification, compression, inference and many more. An intuitive and well-established approach to machine learning is the use of artificial neural networks (NNs), which consist of a group of interconnected nodes, each of which processes information that it receives and then passes this product on to other nodes via weighted connections. In particular, I discuss the first public release of the generic neural network training algorithm, calledSkyNet, and demonstrate its application to astronomical problems focusing on its use in the BAMBI package for accelerated Bayesian inference in cosmology, and the identification of gamma-ray bursters. TheSkyNetand BAMBI packages, which are fully parallelised using MPI, are available athttp://www.mrao.cam.ac.uk/software/.
Adapting Predictive Models for Cepheid Variable Star Classification Using Linear Regression and Maximum Likelihood
Authors: Gupta Kinjal Dhar , Vilalta Ricardo , Asadourian Vicken , Macri Lucas 
Published: July 2015

AbstractWe describe an approach to automate the classification of Cepheid variable stars into two subtypes according to their pulsation mode. Automating such classification is relevant to obtain a precise determination of distances to nearby galaxies, which in addition helps reduce the uncertainty in the current expansion of the universe. One main difficulty lies in the compatibility of models trained using different galaxy datasets; a model trained using a training dataset may be ineffectual on a testing set. A solution to such difficulty is to adapt predictive models across domains; this is necessary when the training and testing sets do not follow the same distribution. The gist of our methodology is to train a predictive model on a nearby galaxy (e.g., Large Magellanic Cloud), followed by a model-adaptation step to make the model operable on other nearby galaxies. We follow a parametric approach to density estimation by modeling the training data (anchor galaxy) using a mixture of linear models. We then use maximum likelihood to compute the right amount of variable displacement, until the testing data closely overlaps the training data. At that point, the model can be directly used in the testing data (target galaxy).
Bayesian Inference for Radio Observations - Going beyond deconvolution
Authors: Lochner Michelle , Bassett Bruce , Kunz Martin , Natarajan Iniyan , Oozeer Nadeem , Smirnov Oleg , Zwart Jonathan 
Published: July 2015

AbstractRadio interferometers suffer from the problem of missing information in their data, due to the gaps between the antennae. This results in artifacts, such as bright rings around sources, in the images obtained. Multiple deconvolution algorithms have been proposed to solve this problem and produce cleaner radio images. However, these algorithms are unable to correctly estimate uncertainties in derived scientific parameters or to always include the effects of instrumental errors. We propose an alternative technique called Bayesian Inference for Radio Observations (BIRO) which uses a Bayesian statistical framework to determine the scientific parameters and instrumental errors simultaneously directly from the raw data, without making an image. We use a simple simulation of Westerbork Synthesis Radio Telescope data including pointing errors and beam parameters as instrumental effects, to demonstrate the use of BIRO.
Constraints on Growth Index from LSS
Authors: Pouri Athina , Basilakos Spyros , Plionis Manolis 
Published: July 2015

AbstractWe utilize the clustering properties of the Luminous Red Galaxies (LRGs) and the growth rate data in order to constrain the growth index (γ) of the linear matter fluctuations based on a standard χ2joint likelihood analysis between theoretical expectations and data. We find a value of γ=0.56± 0.05, perfectly consistent with the expectations of the ΛCDM model, and Ωm0=0.29± 0.02, in very good agreement with the latest Planck results. Our analysis provides significantly more stringent growth index constraints with respect to previous studies as indicated by the fact that the corresponding uncertainty is only ∼ 0.09 γ.
Statistical analysis of cross-correlation sample of 3XMM-DR4 with SDSS-DR10 and UKIDSS-DR9
Authors: Zhang Yan-Xia , Zhao Yong-Heng , Wu Xue-Bing , Tian Hai-Jun 
Published: July 2015

AbstractWe match the XMM-Newton 3XMMi-DR4 catalog with the Sloan Digital Sky Survey (SDSS) Data Release 10 and the United Kingdom Infrared Deep Sky Survey (UKIDSS) Data Release 9. Based on this X-ray/optical/infrared catalog, we probe the distribution of various types of X-ray emitters in the multidimensional parameter space. It is found that quasars, galaxies and stars have some kind distribution rule, especially for stars. The result shows that only using the X-ray/optical features, stars are difficult to discriminate from galaxies and quasars, the added information from infrared band is very helpful to improve the classification result of any classifier. Comparing the classification accuracy of random forests with that of rotation forests, rotation forests show better performance.
What are ‘property rights’, and why do they matter? A comment on Hodgson's article
Authors: BARZEL YORAM 
Published: July 2015

AbstractThis comment divides ‘property rights’ into ‘legal rights’ and ‘economic rights’ in order to distinguish between two very different concepts that are often confounded in the literature. Because of transaction costs, neither kind of rights is ever complete. These are useful in economic analysis as maximizing individuals constantly expand and shrink them. Unlike Hodgson’s, both notions of rights adopted here are positive, useful in analyzing behavior, and not normative as Hodgson (2015) claims them to be. As used by me, they do not devalue property rights as Hodgson claims.
Die Spontaneous Use of Imagery Scale (SUIS)–Entwicklung und teststatistische Prüfung einer deutschen Adaption
Authors: Görgen Stefanie Maria , Hiller Wolfgang , Witthöft Michael 
Published: July 2015

Zusammenfassung. Mentale Vorstellungsbilder spielen bei zahlreichen kognitiven, motorischen und emotionalen Prozessen eine bedeutende Rolle. Die Spontaneous Use of Imagery Scale (SUIS; Kosslyn, Chabris, Shephard & Thompson, 1998 ) ist ein Selbstbeurteilungsinstrument zur Erfassung von interindividuellen Unterschieden hinsichtlich des alltäglichen Gebrauchs mentaler Vorstellungsbilder. In zwei Studien wurde eine deutsche Adaption der SUIS entwickelt und psychometrisch erprobt. Mittels konfirmatorischer Faktorenanalyse wurde in beiden Studien die Eindimensionalität der Skala nachgewiesen. Erste Validitätshinweise ergeben sich aus Beziehungen der SUIS zu Maßen von bildhaften (visuell-imaginativen) sowie verbal-gedanklichen kognitiven Stilen (Studie 1, N = 216). Mit der deutschen Version konnten auch positive Zusammenhänge mit Hypomanie repliziert werden. In der zweiten Studie (N = 447) konnte die interne Konsistenz der deutschen Version durch eine Erweiterung der Skala deutlich verbessert werden. Mit der erweiterten Version der SUIS liegt nun erstmalig für den deutschsprachigen Raum ein Instrument vor, das die Imaginationsneigung reliabel erfassen kann.
Konstruktvalidität und Faktorenstruktur des deutschsprachigen Youth Psychopathic Traits Inventory (YPI) in einer repräsentativen Schulstichprobe
Authors: Stadlin Christina , Pérez Tania , Schmeck Klaus , Gallo Alain Di , Schmid Marc 
Published: July 2015

Zusammenfassung. Die vorliegende Studie untersucht die Konstruktvalidität und Faktorenstruktur der deutschen Version des Youth Psychopathic Traits Inventory (YPI), einem Selbstbeurteilungsverfahren, welches psychopathische Persönlichkeitseigenschaften effizient erfasst. Die Verteilung psychopathischer Persönlichkeitseigenschaften und deren Korrelation mit der selbstberichteten Delinquenz wird in einer repräsentativen Schulstichprobe (N = 840) untersucht. Das YPI zeigte in der deutschsprachigen Version eine gute interne Konsistenz (α = .92). Die Jungen erreichten signifikant höhere Werte als die Mädchen. Die drei Faktoren (interpersonaler, affektiver und behavioraler Faktor) der Originalversion wurden sowohl für Jungen als auch für Mädchen bestätigt. Außerdem korrelierten alle drei Faktoren mit der selbstberichteten Delinquenz. Mit der deutschsprachigen Version des YPI sind psychopathische Persönlichkeitseigenschaften im Selbsturteil reliabel und valide erfassbar.
Differential effects of ischemic vascular disease and Alzheimer’s disease on brain atrophy and cognition
Authors: Zheng Ling , Vinters Harry V , Mack Wendy J , Weiner Michael W , Chui Helena C ,   for the IVD program project
Published: July 2015

We previously reported that pathologic measures of arteriosclerosis (AS), cerebral infarction, and Alzheimer’s disease (AD) are independently correlated with cortical gray matter (CGM) atrophy measured by in vivo magnetic resonance imaging (MRI). Here, we use path analyses to model the associations between these three pathology measures and cognitive impairment, as mediated by CGM atrophy, after controlling for age and education. In this sample of 116 elderly persons followed longitudinally to autopsy (ischemic vascular disease (IVD) program project), differential patterns were observed between AS and atrophy/cognition versus AD and atrophy/cognition. The total effect of AD pathology on global cognition ( β = −0.61, s.e. = 0.06) was four times stronger than that of AS ( β = −0.15, s.e. = 0.08). The effect of AS on cognition appears to occur through cerebral infarction and CGM atrophy ( β = −0.13, s.e. = 0.04). In contrast, the effects of AD pathology on global cognition ( β = −0.50, s.e. = 0.07) occur through a direct pathway that is five times stronger than the indirect pathway acting through CGM atrophy ( β = −0.09, s.e. = 0.03). The strength of this direct AD pathway was not significantly mitigated by adding hippocampal volume to the model. AD pathology affects cognition not only through brain atrophy, but also via an unmeasured pathway that could be related to synaptic dysfunction before the development of cortical atrophy.
A Rac/Cdc42 exchange factor complex promotes formation of lateral filopodia and blood vessel lumen morphogenesis
Authors: Abraham Sabu , Scarcia Margherita , Bagshaw Richard D. , McMahon Kathryn , Grant Gary , Harvey Tracey , Yeo Maggie , Esteves Filomena O.G. , Thygesen Helene H. , Jones Pamela F. , Speirs Valerie , Hanby Andrew M. , Selby Peter J. , Lorger Mihaela , Dear T. Neil , Pawson Tony , Marshall Christopher J. , Mavria Georgia 
Published: July 2015

AbstractDuring angiogenesis, Rho-GTPases influence endothelial cell migration and cell–cell adhesion; however it is not known whether they control formation of vessel lumens, which are essential for blood flow. Here, using an organotypic system that recapitulates distinct stages of VEGF-dependent angiogenesis, we show that lumen formation requires early cytoskeletal remodelling and lateral cell–cell contacts, mediated through the RAC1 guanine nucleotide exchange factor (GEF) DOCK4 (dedicator of cytokinesis 4). DOCK4 signalling is necessary for lateral filopodial protrusions and tubule remodelling prior to lumen formation, whereas proximal, tip filopodia persist in the absence of DOCK4. VEGF-dependent Rac activation via DOCK4 is necessary for CDC42 activation to signal filopodia formation and depends on the activation of RHOG through the RHOG GEF, SGEF. VEGF promotes interaction of DOCK4 with the CDC42 GEF DOCK9. These studies identify a novel Rho-family GTPase activation cascade for the formation of endothelial cell filopodial protrusions necessary for tubule remodelling, thereby influencing subsequent stages of lumen morphogenesis.
Influencing the properties of dysprosium single-molecule magnets with phosphorus donor ligands
Authors: Pugh Thomas , Tuna Floriana , Ungur Liviu , Collison David , McInnes Eric J.L. , Chibotaru Liviu F. , Layfield Richard A. 
Published: July 2015

AbstractSingle-molecule magnets are a type of coordination compound that can retain magnetic information at low temperatures. Single-molecule magnets based on lanthanides have accounted for many important advances, including systems with very large energy barriers to reversal of the magnetization, and a di-terbium complex that displays magnetic hysteresis up to 14 K and shows strong coercivity. Ligand design is crucial for the development of new single-molecule magnets: organometallic chemistry presents possibilities for using unconventional ligands, particularly those with soft donor groups. Here we report dysprosium single-molecule magnets with neutral and anionic phosphorus donor ligands, and show that their properties change dramatically when varying the ligand from phosphine to phosphide to phosphinidene. A phosphide-ligated, trimetallic dysprosium single-molecule magnet relaxes via the second-excited Kramers' doublet, and, when doped into a diamagnetic matrix at the single-ion level, produces a large energy barrier of 256 cm−1 and magnetic hysteresis up to 4.4 K.
Electric-field-induced strong enhancement of electroluminescence in multilayer molybdenum disulfide
Authors: Li Dehui , Cheng Rui , Zhou Hailong , Wang Chen , Yin Anxiang , Chen Yu , Weiss Nathan O. , Huang Yu , Duan Xiangfeng 
Published: July 2015

AbstractThe layered transition metal dichalcogenides have attracted considerable interest for their unique electronic and optical properties. While the monolayer MoS2 exhibits a direct bandgap, the multilayer MoS2 is an indirect bandgap semiconductor and generally optically inactive. Here we report electric-field-induced strong electroluminescence in multilayer MoS2. We show that GaN–Al2O3–MoS2 and GaN–Al2O3–MoS2–Al2O3-graphene vertical heterojunctions can be created with excellent rectification behaviour. Electroluminescence studies demonstrate prominent direct bandgap excitonic emission in multilayer MoS2 over the entire vertical junction area. Importantly, the electroluminescence efficiency observed in multilayer MoS2 is comparable to or higher than that in monolayers. This strong electroluminescence can be attributed to electric-field-induced carrier redistribution from the lowest energy points (indirect bandgap) to higher energy points (direct bandgap) in k-space. The electric-field-induced electroluminescence is general for other layered materials including WSe2 and can open up a new pathway towards transition metal dichalcogenide-based optoelectronic devices.
The free energy of mechanically unstable phases
Authors: van de Walle A. , Hong Q. , Kadkhodaei S. , Sun R. 
Published: July 2015

AbstractPhase diagrams provide ‘roadmaps’ to the possible states of matter. Their determination traditionally rests on the assumption that all phases, even unstable ones, have well-defined free energies under all conditions. However, this assumption is commonly violated in condensed phases due to mechanical instabilities. This long-standing problem impedes thermodynamic database development, as pragmatic attempts at solving this problem involve delicate extrapolations that are highly nonunique and that lack an underlying theoretical justification. Here we propose an efficient computational solution to this problem that has a simple interpretation, both as a topological partitioning of atomic configuration space and as a minimally constrained physical system. Our natural scheme smoothly extends the free energy of stable phases, without relying on extrapolation, thus enabling a formal assessment of widely used extrapolation schemes.
Scopolamine effects on functional brain connectivity: a pharmacological model of Alzheimer’s disease
Authors: Bajo R. , Pusil S. , López M. E. , Canuet L. , Pereda E. , Osipova D. , Maestú F. , Pekkonen E. 
Published: July 2015

AbstractScopolamine administration may be considered as a psychopharmacological model of Alzheimer’s disease (AD). Here, we studied a group of healthy elderly under scopolamine to test whether it elicits similar changes in brain connectivity as those observed in AD, thereby verifying a possible model of AD impairment. We did it by testing healthy elderly subjects in two experimental conditions: glycopyrrolate (placebo) and scopolamine administration. We then analyzed magnetoencephalographic (MEG) data corresponding to both conditions in resting-state with eyes closed. This analysis was performed in source space by combining a nonlinear frequency band-specific measure of functional connectivity (phase locking value, PLV) with network analysis methods. Under scopolamine, functional connectivity between several brain areas was significantly reduced as compared to placebo, in most frequency bands analyzed. Besides, regarding the two complex network indices studied (clustering and shortest path length), clustering significantly decreased in the alpha band while shortest path length significantly increased also in alpha band both after scopolamine administration. Overall our findings indicate that both PLV and graph analysis are suitable tools to measure brain connectivity changes induced by scopolamine, which causes alterations in brain connectivity apparently similar to those reported in AD.