bluuebunny/crossref_metadata_2025_split huggingface dataset:
Lessons learnt from the solar neighbourhood and the Kepler field
Authors: Casagrande L. 
Published: September 2016

AbstractSetting the timeline of the events which shaped the Milky Way disc through its 13 billion year old history is one of the major challenges in the theory of galaxy formation. Achieving this goal is possible using late‐type stars, which in virtue of their long lifetimes can be regarded as fossil remnants from various epochs of the formation of the Galaxy. There are two main paths to reliably age‐date late‐type stars: astrometric distances for stars in the turn‐off and subgiant region, or oscillation frequencies along the red giant branch. So far, these methods have been applied to large samples of stars in the solar neighbourhood, and in the Kepler field. I review these studies, emphasize how they complement each other, and highlight some of the constraints they provide for Galactic modelling. I conclude with the prospects and synergies that astrometric (Gaia) and asteroseismic space‐borne missions reserve to the field of Galactic archaeology, and advocate that survey selection functions should be kept as simple as possible, relying on basic observables such as colours and magnitudes only.
SP Ace: A new code to estimate Teff, log g, and elemental abundances
Authors: Boeche C. 
Published: September 2016

AbstractSP_Ace is a FORTRAN95 code that derives stellar parameters and elemental abundances from stellar spectra. To derive these parameters, SP_Ace does not measure equivalent widths of lines nor it uses templates of synthetic spectra, but it employs a new method based on a library of General Curve‐Of‐Growths. To date SP_Ace works on the wavelength range 5212–6860 Å and 8400–8921 Å, and at the spectral resolution R = 2000–20000. Extensions of these limits are possible. SP_Ace is a highly automated code suitable for application to large spectroscopic surveys. A web front end to this service is publicly available at http://dc.g‐vo.org/SP_ACE together with the library and the binary code.
Carbon‐enhanced metal‐poor stars in different environments
Authors: Salvadori S. , Skúladóttir Á. , de Bennassuti M. 
Published: September 2016

AbstractThe origin of carbon‐enhanced metal‐poor (CEMP) stars and their possible connections with the chemical elements produced by the first stellar generations is still highly debated. We briefly review observations of CEMP stars in different environments (Galactic stellar halo, ultra‐faint, and classical dwarf galaxies) and interpret their properties using cosmological chemical‐evolution models for the formation of the Local Group. We discuss the implications of current observations for the properties of the first stars, clarify why the fraction of carbon‐enhanced to carbon‐normal stars varies in dwarf galaxies with different luminosity, and discuss the origin of the first CEMP(‐no) star found in the Sculptor dwarf galaxy.
The Milky Way disk non‐axisymmetries and galactoseismology
Authors: Famaey B. , Monari G. , Siebert A. 
Published: September 2016

AbstractCurrent Galactic dynamical models still most often rely on the assumptions of a smooth time‐independent and axisymmetric gravitational potential. On the other hand, ab initio simulations in a cosmological context are not very flexible to precisely produce a model of our own Galaxy, or to disentangle the internal and the external/environmental effects on its evolution. To make such a disentanglement possible, one can first try to isolate all the possible effects of one main nonaxisymmetric perturber, such as the bar or the spiral arms, through perturbation theory applied to smooth time‐independent axisymmetric potentials. For instance, it has recently been realized in this way that observed vertical oscillations of the Galactic disk could be due to such internal perturbations, rather than to external perturbers as previously believed. Here we summarize the general analytical framework, in the context of perturbation theory, which allowed us to compute the stellar vertical bulk motions generated by a single internal perturber such as the Galactic bar. We point out that non‐linear couplings can nevertheless be present when multiple non‐axisymmetric perturbers – such as multiple spiral patterns together with a central bar – are present simultaneously, thus potentially enhancing the effect presented here.
Radial migration and chemical evolution in the Milky Way
Authors: Prantzos N. 
Published: September 2016

AbstractThe role of radial migration on the chemical evolution of the Milky Way is studied with semi‐analytical models of disk evolution, using several new/updated ingredients and parametrized prescriptions for blurring and churning. It is found that radial migration impacts on several properties of the local disk (shape and dispersion of the age‐metallicity relation, metallicity distribution), it may explain some chemical properties of the local thin and thick disks (i.e. the two‐branch shape of the O/Fe vs. Fe/H relation) and it affects the past abundance profiles of the stellar population.
The noise performance of CMOS Miller operational transconductance amplifiers with embedded current‐buffer frequency compensation
Authors: Grasso Alfio Dario , Palumbo Gaetano , Pennisi Salvatore , Sansen Willy 
Published: September 2016

SummaryThe noise of cascode transistors is usually considered to be negligible. It is demonstrated in this paper that this is not the case for an operational transconductance amplifiers exploiting Miller compensation via an embedded current buffer. Analysis, validated through simulations, shows that the noise power spectral density of the cascode transistor implementing the buffer, can be dominant at high frequencies. Its contribution can be of the same order of magnitude as that of the transistors in the first gain stage. A design equation is also given to limit the increase of this output noise contribution. Copyright © 2016 John Wiley & Sons, Ltd.
CDNPatch: a cost‐effective failover mechanism for hybrid CDN‐P2P live streaming systems
Authors: Wang Chih‐Chiang , Lin Ying‐Dar 
Published: September 2016

SummaryAmong the most well‐established live media distribution technologies is content delivery network (CDN), which improves user‐perceived quality of service by delivering content from proxy servers deployed at the Internet's edge. In recent years, CDN providers started to tap into their subscribers' peer‐to‐peer (P2P) capacity to alleviate their server costs. Under the inherent peer dynamics, a major challenge of these hybrid CDN‐P2P systems is to provide efficient failure recovery with good quality of service guarantees at a reduced server cost. In this work we propose a cost‐effective failover solution named CDNPatch to address the aforementioned problem. CDNPatch enables peers to periodically precompute a few backup content suppliers by efficient information exchange and maintenance algorithms, and leverages auxiliary CDN servers and an economic server provisioning algorithm to reduce the chance of playback interruption occurring to peers. Our simulation results show that CDNPatch can mask the impact of peer dynamics of 3 real P2P systems, namely, SOPCast, PPStream, and PPTV, with 100 % failure recovery success rate and a failure recovery time less than 1 second at a cost of small P2P communication overhead of less than 1 kilobits per second, while using only 10%, 21%, and 51%, respectively, of the pure CDN scheme's server consumption.
Do Circadian Rhythms Draw the Patterns of Sustained Mental Vigor and Ailment?
Authors: Sharma Ashish , Goyal Rohit 
Published: September 2016

ABSTRACT

Preclinical Research

Circadian rhythms are fundamental processes in all cells that coordinate a variety of cellular functions related to a specific time of the day. Disruption of circadian rhythms markedly impacts homeostasis. In this Commentary, we present data that disruption of circadian rhythm may lead to the pathogenesis of neurodegenerative states. In this context, we further argue that there is an urgent need of developing new generations of compounds, chronobiotics, to modulate the molecular substrates of circadian timing system. Chronobiotics conceptually offer an effective way for restoration and protection from the consequences of the circadian disruption. We also briefly discuss whether dysfunctional circadian rhythms are a major driver of aging. Drug Dev Res 77 : 469–473, 2016. © 2016 Wiley Periodicals, Inc.
Evaluating methods for preventing smoke spread through ventilation systems using fire dynamics simulator
Authors: Wahlqvist Jonathan , van Hees Patrick 
Published: September 2016

SummaryFires in enclosures equipped with mechanical ventilation remain one of the key issues for fire safety assessment in multifamily homes and industries. Therefore, a wide variation of methods for preventing smoke spread through the ventilation system exist and are applied, in performance‐based designs. Through the use of the heating, ventilation and air conditioning (HVAC) model in the fire dynamics simulator, several different common and less common methods for preventing smoke spread in the ventilation system were tested. The effects on smoke spread with changing building leakage and fire growth rates were also investigated. The results were evaluated by determining the total soot spread from the fire room to other compartments connected to the ventilation system, as well as soot/thermal load on the fans and system in general. The maximum and average heat release rate was also of interest and hence compared between systems. It was found that, while many methods perform similar, a few proven methods, such as fire and smoke dampers, performed very well with very little smoke spread to the rest of the system. The study should be considered as an introduction to implementing a similar methodology in specific cases because different ventilations systems will present very different challenges and weaknesses. Copyright © 2016 John Wiley & Sons, Ltd.
Localized removal affects white‐tailed deer space use and contacts
Authors: Tosa Marie I. , Schauber Eric M. , Nielsen Clayton K. 
Published: September 2016

ABSTRACTTransmission and impact of infectious diseases can be altered if host social structure is disrupted by disease outbreaks or lethal management. Specifically, if remnants of depopulated groups join or increase contact with neighboring groups, between‐group transmission may increase even as population density decreases. We tested whether this phenomenon could apply to diseases of white‐tailed deer (Odocoileus virginianus) by using a before‐after‐control‐impact design. We monitored space use and contacts among adult female and juvenile deer in southern Illinois during 2011–2014; midway through each study season, we removed all members except 1 collared deer from centrally located groups and left control groups intact. After group removal, remnant adult females shortened duration of contacts with neighboring groups, whereas remnant juveniles responded with greater shifts in space use and appeared to join neighboring groups. Together, our study points to potential age‐specific responses of deer to social disruption, with evidence that juveniles respond in ways that could shift disease transmission dynamics toward frequency dependence. These findings highlight the need for focused research into the importance of social disruption in disease dynamics, and lend support for complete group removal (if possible) when culling for disease management. © 2016 The Wildlife Society.
Association of Calf Muscle Pump Stimulation With Sleep Quality in Adults
Authors: Baniak Lynn M. , Pierce Carolyn S. , McLeod Kenneth J. , Chasens Eileen R. 
Published: September 2016

AbstractPrevention of lower extremity fluid pooling (LEFP) is associated with improved sleep quality. Physical activity and compression stockings are non‐invasive methods used to manage LEFP, but both are associated with low adherence. Calf muscle pump (CMP) stimulation is an alternative and more convenient approach. Convenience sampling was used to recruit 11 participants between ages 45 and 65 with poor sleep quality. A within‐person single‐group pre‐test–post‐test design was used to evaluate changes in sleep quality, daytime sleepiness, and functional outcomes sensitive to impaired sleep as measured by the Pittsburgh Sleep Quality Index (PSQI), Functional Outcomes of Sleep Questionnaire, and Epworth Sleepiness Scale after 4 weeks of CMP stimulation. Statistical analysis included effect size (ES) calculations. After daily use of CMP stimulation, participants demonstrated improvement in overall sleep quality (ES = −.97) and a large reduction in daily disturbance from poor sleep (ES = −1.25). Moderate improvements were observed in daytime sleepiness (ES = −.53) and functional outcomes sensitive to sleepiness (ES = .49). Although causality could not be determined with this study design, these results support further research to determine whether CMP stimulation can improve sleep quality. © 2016 Wiley Periodicals, Inc.
Characteristics of Qualitative Descriptive Studies: A Systematic Review
Authors: Kim Hyejin , Sefcik Justine S. , Bradway Christine 
Published: September 2016

AbstractQualitative description (QD) is a term that is widely used to describe qualitative studies of health care and nursing‐related phenomena. However, limited discussions regarding QD are found in the existing literature. In this systematic review, we identified characteristics of methods and findings reported in research articles published in 2014 whose authors identified the work as QD. After searching and screening, data were extracted from the sample of 55 QD articles and examined to characterize research objectives, design justification, theoretical/philosophical frameworks, sampling and sample size, data collection and sources, data analysis, and presentation of findings. In this review, three primary findings were identified. First, although there were some inconsistencies, most articles included characteristics consistent with the limited available QD definitions and descriptions. Next, flexibility or variability of methods was common and effective for obtaining rich data and achieving understanding of a phenomenon. Finally, justification for how a QD approach was chosen and why it would be an appropriate fit for a particular study was limited in the sample and, therefore, in need of increased attention. Based on these findings, recommendations include encouragement to researchers to provide as many details as possible regarding the methods of their QD studies so that readers can determine whether the methods used were reasonable and effective in producing useful findings. © 2016 Wiley Periodicals, Inc.
The effect of statins on influenza‐like illness morbidity and mortality
Authors: Brassard Paul , Wu Jennifer W. , Ernst Pierre , Dell'Aniello Sophie , Smiechowski Brielan , Suissa Samy 
Published: September 2016

AbstractPurposeThe effect of statins on cytokine‐mediated inflammatory responses may impact on the prognosis of influenza. We assessed whether statin use decreases the incidence of adverse influenza‐related outcomes. Additionally, we used a new‐user study design to minimize healthy user bias. We further examined the possibility of non‐causal associations by using unrelated outcomes.MethodsWe used the UK Clinical Practice Research Datalink to identify all patients aged 30 or older diagnosed with influenza‐like illness during 1997–2010. Statin users were compared with propensity score‐matched patients not receiving statins. The outcome was hospitalization for influenza or pneumonia or death in the 30 days following influenza diagnosis. Logistic regression estimated cumulative incidence ratios.ResultsThe study cohort included 5181 statin users matched to 5181 non‐users. The 30‐day incidence of hospitalization or death was 3.5% in statin users and 5.2% in non‐users, resulting in a 27% lower incidence with statin use (cumulative incidence ratio: 0.73, 95%CI: 0.59–0.89). New statin users were less protected against our composite outcome. The effect of statins was less pronounced among those with respiratory and cardiac disease. Statin use was shown to be associated with a non‐statistically significant risk reduction of motor vehicle accident and burns.ConclusionThe attenuation of the effect of statins with the new‐user design, supporting evidence from the assessment of effect modification, and additional sub‐analyses evaluating the effect of statins on non‐related outcomes suggest that the beneficial effect of statins on influenza‐related adverse outcomes may be explained by a healthy user bias. Copyright © 2016 John Wiley & Sons, Ltd.
A computer program to simplify analysis of mass scan data of organometallic compounds from high‐resolution mass spectrometers
Authors: Doran Michael C. , LeBlanc Kelly L. 
Published: September 2016

RationaleSoftware accompanying high‐resolution mass spectrometers, particularly that used for the analysis of organometallic compounds, has lagged the technology of the instruments themselves. We have developed a computer program that partially fills this gap.MethodsGiven the user's expectation for the number of atoms of a target element likely to be in an ion, the program calculates isotopologue mass differences for combinations of that element's isotopes and their expected intensity ratios relative to the most abundant isotopologue. These values are compared with mass differences and intensity ratios found in the experimental mass scan data and these metrics feed into a four‐factor scoring model which ranks the ions as to the likelihood of each containing the specified number of the target atoms. The program was tested using experimental data obtained for selenomethionine.ResultsAcross a broad range of sample concentrations, the program consistently ranked selenomethionine at or near the top of the list of ions that passed the screening and ranking process. Mass scan data files in excess of 24,000 records were analyzed in less than one second.ConclusionsThe program is quick and efficient at scanning voluminous experimental data files for the presence of ions containing the expected number of atoms of a target element. Best results were obtained the scarcer the target element and the more isotopes it comprised. Copyright © 2016 John Wiley & Sons, Ltd.
Shape‐Dependent Properties of Silver Nanocrystals as Electrocatalysts toward Glucose Oxidation Reaction
Authors: Chao Yi‐Ju , Wu Zheng‐Wei , Hsu Su‐Yang , Lee Chien‐Liang 
Published: September 2016

AbstractAg nanoprisms (mean height 136 nm) and Ag nanodisks (mean diameter 41 nm) that are dominated by (111) planes and Ag nanocubes (mean edge length 38 nm) enclosed by (100) planes were prepared and used as catalysts for the D‐glucose oxidation reaction (GOR). A systematic study of the specific activities of these three Ag catalysts, in terms of the electrochemical real surface area (ERSA), was performed to assess their ability to electrocatalyze glucose oxidation. By measuring current per ERSA for glucose oxidation, an order of nanoprisms > nanocubes > nanodisks was obtained for the activity of catalysis of the intermediate on the Ag2O on their surfaces, ascribed to diffusion‐controlled processes. Among these catalysts, the nanoprisms were more sensible to produce Ag2O and AgO after GOR. The results of cyclic tests indicated a higher D‐glucose‐tolerance of the nanoprisms and nanodisks. In addition, the amperometric analyses determined sensitivities of 14 mA mM−1 cm−2, 9.9 mA mM−1 cm−2, and 5.5 mA mM−1 cm−2 for the nanoprisms, nanocubes, and nanodisks, respectively. The comparison based on the same ERSA showed that the nanoprisms had better activity and sensitivity.
Facile Spray Deposition of Photocatalytic ZnO/Cu–In‐Zn‐S Heterostructured Composite Thin Film
Authors: Yang Kai‐Yu , Hsu Han‐Wen , Hsieh Hsin‐Yi , Chang Wei‐Chieh , Li Meng‐Chi , Lin Po‐Chang , Lee Cheng‐Chung , Liu Cheng‐Liang , Lee Tai‐Chou 
Published: September 2016

AbstractWe present a sprayed composite thin film, comprising Cu−In‐Zn−S (CIZS) particles embedded in ZnO matrix for photoelectrochemical hydrogen production from water splitting. CIZS, a photoactive semiconductor was used as a photon absorber, whereas ZnO channels as the pathway for charge transfer. It was found that the distribution of the CIZS particles had a direct impact on the photoelectrochemical (PEC) activity. A more homogeneous dispersion of smaller CIZS particles (0.56 μm) within ZnO matrix exhibited a higher photocurrent density, and 3.27 μmol/ cm2 hydrogen evolution for 5 h. Electrochemical impedance spectroscopy (EIS) was employed to analyze the charge transfer mechanism of this composite thin film. In addition, ZnO coating on top of CIZS particles also served as the adhesion and protection layers. All the PEC experiments were performed in 0.5 M K2SO4 electrolyte. No sacrificial reagents were used. The composite electrode was stable under illumination: 75.67 % of photo‐activity remained after 1 h illumination at a bias of 0.2 V vs. SCE. This study demonstrates a simple and low‐cost spray preparation of composite thin film consisting of particles embedded in any semiconductor matrix.
Use of electric vehicles or hydrogen in the Danish transport sector in 2050?
Authors: Skytte Klaus , Pizarro Amalia , Karlsson Kenneth B. 
Published: September 2016

Denmark has an ambitious long‐term goal to reduce greenhouse gas (GHG) emissions from the transport sector with an overall climate target to be independent of fossil‐fuel consumption by 2050. We compare a likely scenario with two alternative ways to achieve the goal—either with a high percentage of electric vehicles (EV) or with a high percentage of hydrogen use for transportation. The STREAM model—an energy scenario simulating tool—is used to model the different scenarios and their integration with the electricity and heating systems. The major findings are that an increased share of EV can reduce the socioeconomic cost of the energy system in 2050. However, electricity demand for H2 generation via electrolysis is more flexible than EV charging and the production can therefore, to a larger degree be used to out‐balance variable electricity surplus from a high share of wind energy in the power system, reducing the investments in backup capacity. Whether the hydrogen scenario (H2S) is more costly to implement than the EV scenario (EVS) mainly depends on the technological development—especially the improvement on the efficiency of the conversion from electricity to H2 and the cost of the hydrogen fuel cell vehicle. Therefore, the major drivers of a successful H2S are a high efficient flexible H2 production in 2050 and lower vehicle costs, which increase the stability of the power grid, compared to the EVS. Hence, from a socioeconomic view point, the technological path in innovation to achieve fossil‐free transport systems should have vehicle costs and electrolyzers efficiency as their main drivers toward 2050. WIREs Energy Environ 2017, 6:e233. doi: 10.1002/wene.233This article is categorized under:

Wind Power > Economics and Policy
Energy Systems Economics > Economics and Policy
Energy Policy and Planning > Economics and Policy