On "the complete basis set limit" and plane-wave methods in first-principles simulations of water

Water structure, measured by the height of the first peak in oxygen-oxygen radial distributions, is converged with respect to plane-wave basis energy cutoffs for ab initio molecular dynamics simulations, confirming the reliability of plane-wave methods.Comment: 9 pages, 3 figure

Role resources and work-family enrichment: The role of work engagement

The majority of work-family research has focused on negative spillover between demands and outcomes and between the work and family domains (e.g., work-family conflict; see review by Eby, Casper, Lockwood, Bordeaux, & Brinley, 2005). The theory that guided this research was in most cases role stress theory (Greenhaus & Beutell, 1985) or the role scarcity hypothesis (Edwards & Rothbard, 2000). However, according to spillover theory, work-related activities and satisfaction also affect non-work performance, and vice versa. Recently, in line with the positive psychology movement (Seligman & Csikszentmihalyi, 2000), work-family interaction research has also included concepts of positive spillover (Bakker & Schaufeli, 2008; Grzywacz & Marks, 2000). This emerging focus supplements the dominant conflict perspective by identifying new ways of cultivating human resource strength

Persistence of Covalent Bonding in Liquid Silicon Probed by Inelastic X-ray Scattering

Metallic liquid silicon at 1787K is investigated using x-ray Compton scattering. An excellent agreement is found between the measurements and the corresponding Car-Parrinello molecular dynamics simulations. Our results show persistence of covalent bonding in liquid silicon and provide support for the occurrence of theoretically predicted liquid-liquid phase transition in supercooled liquid states. The population of covalent bond pairs in liquid silicon is estimated to be 17% via a maximally-localized Wannier function analysis. Compton scattering is shown to be a sensitive probe of bonding effects in the liquid state.Comment: 5pages, 3 postscript figure

Student interpretations of the terms in first-order ordinary differential equations in modelling contexts

A study of first-year undergraduate students′ interpretational difficulties with first-order ordinary differential equations (ODEs) in modelling contexts was conducted using a diagnostic quiz, exam questions and follow-up interviews. These investigations indicate that when thinking about such ODEs, many students muddle thinking about the function that gives the quantity to be determined and the equation for the quantity's rate of change, and at least some seem unaware of the need for unit consistency in the terms of an ODE. It appears that shifting from amount-type thinking to rates-of-change-type thinking is difficult for many students. Suggestions for pedagogical change based on our results are made

Metagenomic characterization of swine slurry in a North American swine farm operation

Abstract Modern day large-scale, high-density farming environments are inherently susceptible to viral outbreaks, inadvertently creating conditions that favor increased pathogen transmission and potential zoonotic spread. Metagenomic sequencing has proven to be a useful tool for characterizing the microbial burden in both people, livestock, and environmental samples. International efforts have been successful at characterizing pathogens in commercial farming environments, especially swine farms, however it is unclear whether the full extent of microbial agents have been adequately captured or is representative of farms elsewhere. To augment international efforts we performed metagenomic next-generation sequencing on nine swine slurry and three environmental samples from a United States of America (U.S.A.) farm operation, characterized the microbial composition of slurry, and identified novel viruses. We assembled a remarkable total of 1792 viral genomes, of which 554 were novel/divergent. We assembled 1637 Picobirnavirus genome segments, of which 538 are novel. In addition, we discovered 10 new viruses belonging to a novel taxon: porcine Statoviruses; which have only been previously reported in human, macaques, mouse, and cows. We assembled 3 divergent Posaviruses and 3 swine Picornaviruses. In addition to viruses described, we found other eukaryotic genera such as Entamoeba and Blastocystis, and bacterial genera such as Listeria, Treponema, Peptoclostridium and Bordetella in the slurry. Of these, two species Entamoeba histolytica and Listeria monocytogenes known to cause human disease were detected. Further, antimicrobial resistance genes such as tetracycline and MLS (macrolide, lincosamide, streptogramin) were also identified. Metagenomic surveillance in swine fecal slurry has great potential for novel and antimicrobial resistant pathogen detection

Acupuncture and related therapies for symptom management in palliative cancer care: Systematic review and meta-analysis

Copyright © 2016 Wolters Kluwer Health, Inc. All rights reserved. Available systematic reviews showed uncertainty on the effectiveness of using acupuncture and related therapies for palliative cancer care. The aim of this systematic review and meta-analysis was to summarize current best evidence on acupuncture and related therapies for palliative cancer care. Five international and 3 Chinese databases were searched. Randomized controlled trials (RCTs) comparing acupuncture and related therapies with conventional or sham treatments were considered. Primary outcomes included fatigue, paresthesia and dysesthesias, chronic pain, anorexia, insomnia, limb edema, constipation, and health-related quality of life, of which effective conventional interventions are limited. Thirteen RCTs were included. Compared with conventional interventions, meta-analysis demonstrated that acupuncture and related therapies significantly reduced pain (2 studies, n=175, pooled weighted mean difference: -0.76, 95% confidence interval: -0.14 to -0.39) among patients with liver or gastric cancer. Combined use of acupuncture and related therapies and Chinese herbal medicine improved quality of life in patients with gastrointestinal cancer (2 studies, n=111, pooled standard mean difference: 0.75, 95% confidence interval: 0.36-1.13). Acupressure showed significant efficacy in reducing fatigue in lung cancer patients when compared with sham acupressure. Adverse events for acupuncture and related therapies were infrequent and mild. Acupuncture and related therapies are effective in reducing pain, fatigue, and in improving quality of life when compared with conventional intervention alone among cancer patients. Limitations on current evidence body imply that they should be used as a complement, rather than an alternative, to conventional care. Effectiveness of acupuncture and related therapies for managing anorexia, reducing constipation, paresthesia and dysesthesia, insomnia, and limb edema in cancer patients is uncertain, warranting future RCTs in these areas

Effects of metallic spacer in layered superconducting Sr2(Mgy_yTi1−y_{1-y})O3FeAs

The highly two-dimensional superconducting system Sr2(Mg$_y$Ti$_{1-y}$)O3FeAs, recently synthesized in the range of 0.2 < y < 0.5, shows an Mg concentration-dependent $T_c$. Reducing the Mg concentration from y=0.5 leads to a sudden increase in $T_c$, with a maximum $T_c$ ~40 K at y=0.2. Using first principles calculations, the unsynthesized stoichiometric y=0 and the substoichiometric y=0.5 compounds have been investigated. For the 50% Mg-doped phase (y=0.5), Sr2(Mg$_y$Ti$_{1-y}$)O3 layers are completely insulating spacers between FeAs layers, leading to the fermiology such as that found for other Fe pnictides. At y=0, representing a phase with metallic Sr2TiO3 layers, the $\Gamma$-centered Fe-derived Fermi surfaces (FSs) considerably shrink or disappear. Instead, three $\Gamma$-centered Ti FSs appear, and in particular two of them have similar size, like in MgB2. Interestingly, FSs have very low Fermi velocity in large fractions: the lowest being 0.6$\times10^6$ cm/s. Furthermore, our fixed spin moment calculations suggest the possibility of magnetic ordering, with magnetic Ti and nearly nonmagnetic Fe ions. These results indicate a crucial role of Sr2(Mg$_y$Ti$_{1-y}$)O3 layers in this superconductivity.Comment: 7 pages; Proceedings of ICSM-201

Data sharing in DHT based P2P systems

International audienceThe evolution of peer-to-peer (P2P) systems triggered the building of large scale distributed applications. The main application domain is data sharing across a very large number of highly autonomous participants. Building such data sharing systems is particularly challenging because of the "extreme" characteristics of P2P infrastructures: massive distribution, high churn rate, no global control, potentially untrusted participants... This article focuses on declarative querying support, query optimization and data privacy on a major class of P2P systems, that based on Distributed Hash Table (P2P DHT). The usual approaches and the algorithms used by classic distributed systems and databases forproviding data privacy and querying services are not well suited to P2P DHT systems. A considerable amount of work was required to adapt them for the new challenges such systems present. This paper describes the most important solutions found. It also identies important future research trends in data management in P2P DHT systems