Prediction of higher thermoelectric performance in BiCuSeO by weakening electron-polar optical phonon scattering

BiCuSeO is a promising thermoelectric material, but its applications are hindered by low carrier mobility. We use first-principles calculations to analyse electron–phonon scattering mechanisms and evaluate their contributions to the thermoelectric figure of merit ZT. The combined scattering of carriers by polar optical (PO) and longitudinal acoustic (LA) phonons yields an intrinsic hole mobility of 32 cm^{2} V^{−1} s^{−1} at room temperature and a temperature power law of T^{−1.5} between 100–875 K, which agree well with experiments. We demonstrate that electron–phonon scattering in the Cu–Se layer dominates at low T (< 500 K), while contributions from the Bi–O layer become increasingly significant at higher T. At room temperature, ZT is calculated to be 0.48 and can be improved by 30% through weakening PO phonon scattering in the Cu–Se layer. This finding agrees with the experimental observation that weakening the electron–phonon interaction by Te substitution in the Cu–Se layer improves mobility and ZT. At high T, the figure of merit is improved by weakening the electron–PO phonon scattering in the Bi–O layer instead. The theoretical ZT limit of BiCuSeO is calculated to be 2.5 at 875 K

A-Z of nutritional supplements: dietary supplements, sports nutrition foods and ergogenic aids for health and performance-Part 20

As usual, the alphabet throws together a mixture of supplements with different levels of popularity and scientific support. Part 20 covers some rarely reported, studied and/or little used supplements in sport: glycine, histidine and inosine. The majority of human studies of supplementation with the essential amino acid histidine has involved clinical work. In terms of athletic performance, there is current interest in supplementation strategies to increase muscle content of the histidine-containing dipeptide (HCD), carnosine. Despite some interest in the use of a chicken breast extract (CBEX) described in this article, most of the focus in this area involves β-alanine supplementation (covered in part 5). There was some interest in inosine as an ergogenic aid in the 1990s but it appears not to have been studied since then. Meanwhile, there appears little role for glycine supplementation in sport although some interest in glycine-containing compounds is possible. β-Hydroxymethyl β-butyrate (HMB) is much more well known, with marketing usually targeting bodybuilders

Antineoplastic activity of idazoxan hydrochloride

Idazoxan hydrochloride (IDA) is a 241 molecular weight imidazoline and adrenoreceptor ligand. It binds to mitochondrial membranes and promotes apoptosis of pancreatic beta cells. Since IDA has not been tested against tumor cells, the purpose of our study was to determine if IDA has antineoplastic activity. We used the conversion of a soluble tetrazolium salt to an insoluble formazan precipitate and differential staining cytotoxicity assays to determine if IDA was cytotoxic to cell lines of murine lung cancer and human prostate cancer, as well as to a variety of fresh human tumor samples. We used flow cytometry to analyze cell death and calreticulin expression. IDA is cytotoxic to both cell lines and against aliquots of specimens of breast, gastric, lung, ovarian and prostate cancers as well as non-Hodgkin’s lymphoma. It produces apoptotic cell death and promotes calreticulin expression, suggesting that IDA might be immunomodulatory in vivo. We anticipate that IDA will be clinically useful in cancer treatment

Nutrition Strategies for Triathlon

Contemporary sports nutrition guidelines recommend that each athlete develop a personalised, periodised and practical approach to eating that allows him or her to train hard, recover and adapt optimally, stay free of illness and injury and compete at their best at peak races. Competitive triathletes undertake a heavy training programme to prepare for three different sports while undertaking races varying in duration from 20 min to 10 h. The everyday diet should be adequate in energy availability, provide CHO in varying amounts and timing around workouts according to the benefits of training with low or high CHO availability and spread high-quality protein over the day to maximise the adaptive response to each session. Race nutrition requires a targeted and well-practised plan that maintains fuel and hydration goals over the duration of the specific event, according to the opportunities provided by the race and other challenges, such as a hot environment. Supplements and sports foods can make a small contribution to a sports nutrition plan, when medical supplements are used under supervision to prevent/treat nutrient deficiencies (e.g. iron or vitamin D) or when sports foods provide a convenient source of nutrients when it is impractical to eat whole foods. Finally, a few evidence-based performance supplements may contribute to optimal race performance when used according to best practice protocols to suit the triathlete’s goals and individual responsiveness

Big-Data-Driven Materials Science and its FAIR Data Infrastructure

This chapter addresses the forth paradigm of materials research -- big-data driven materials science. Its concepts and state-of-the-art are described, and its challenges and chances are discussed. For furthering the field, Open Data and an all-embracing sharing, an efficient data infrastructure, and the rich ecosystem of computer codes used in the community are of critical importance. For shaping this forth paradigm and contributing to the development or discovery of improved and novel materials, data must be what is now called FAIR -- Findable, Accessible, Interoperable and Re-purposable/Re-usable. This sets the stage for advances of methods from artificial intelligence that operate on large data sets to find trends and patterns that cannot be obtained from individual calculations and not even directly from high-throughput studies. Recent progress is reviewed and demonstrated, and the chapter is concluded by a forward-looking perspective, addressing important not yet solved challenges.Comment: submitted to the Handbook of Materials Modeling (eds. S. Yip and W. Andreoni), Springer 2018/201

Implementation of a chemical background method for atmospheric OH measurements by laser-induced fluorescence: characterisation and observations from the UK and China

Hydroxyl (OH) and hydroperoxy (HO2) radicals are central to the understanding of atmospheric chemistry. Owing to their short lifetimes, these species are frequently used to test the accuracy of model predictions and their underlying chemical mechanisms. In forested environments, laser-induced fluorescence–fluorescence assay by gas expansion (LIF–FAGE) measurements of OH have often shown substantial disagreement with model predictions, suggesting the presence of unknown OH sources in such environments. However, it is also possible that the measurements have been affected by instrumental artefacts, due to the presence of interfering species that cannot be discriminated using the traditional method of obtaining background signals via modulation of the laser excitation wavelength (“OHwave”). The interference hypothesis can be tested by using an alternative method to determine the OH background signal, via the addition of a chemical scavenger prior to sampling of ambient air (“OHchem”). In this work, the Leeds FAGE instrument was modified to include such a system to facilitate measurements of OHchem, in which propane was used to selectively remove OH from ambient air using an inlet pre-injector (IPI). The IPI system was characterised in detail, and it was found that the system did not reduce the instrument sensitivity towards OH ( 99 %) without the removal of OH formed inside the fluorescence cell (< 5 %). Tests of the photolytic interference from ozone in the presence of water vapour revealed a small but potentially significant interference, equivalent to an OH concentration of ∼4×105 molec. cm−3 under typical atmospheric conditions of [O3] =50 ppbv and [H2O] =1 %. Laboratory experiments to investigate potential interferences from products of isoprene ozonolysis did result in interference signals, but these were negligible when extrapolated down to ambient ozone and isoprene levels. The interference from NO3 radicals was also tested but was found to be insignificant in our system. The Leeds IPI module was deployed during three separate field intensives that took place in summer at a coastal site in the UK and both in summer and winter in the megacity of Beijing, China, allowing for investigations of ambient OH interferences under a wide range of chemical and meteorological conditions. Comparisons of ambient OHchem measurements to the traditional OHwave method showed excellent agreement, with OHwave vs OHchem slopes of 1.05–1.16 and identical behaviour on a diel basis, consistent with laboratory interference tests. The difference between OHwave and OHchem (“OHint”) was found to scale non-linearly with OHchem, resulting in an upper limit interference of (5.0±1.4) ×106 molec. cm−3 at the very highest OHchem concentrations measured (23×106 molec. cm−3), accounting for ∼14 %–21 % of the total OHwave signal

A generalization of the q-Saalschutz sum and the Burge transform

A generalization of the q-(Pfaff)-Saalschutz summation formula is proved. This implies a generalization of the Burge transform, resulting in an additional dimension of the ``Burge tree''. Limiting cases of our summation formula imply the (higher-level) Bailey lemma, provide a new decomposition of the q-multinomial coefficients, and can be used to prove the Lepowsky and Primc formula for the A_1^{(1)} string functions.Comment: 18 pages, AMSLaTe

ACSM Expert Consensus Statement on Weight Loss in Weight-Category Sports

Weight-category sports are defined by the requirement of a weigh-in before competition to provide performance equity and reduced injury risks by eliminating size discrepancies. Athletes in these sports try to gain a theoretical advantage by competing in weight divisions that are lower than their day-to-day body mass (BM), using a combination of chronic strategies (body-fat losses) and acute manipulations over a period of hours to days before weigh-in ("making weight"). Strategies to support safer practices include minimal competition weight classification based on preseason body composition, reductions in the period between weigh-in and competition, and prohibition of unhealthy weight loss techniques. At an individual level, expert guidance by a sports nutrition professional can help an athlete to establish a pragmatic and long-term approach to BM management, recognizing the nuances of their sport, to achieve favorable outcomes for both health and performance

Bystander responses to a violent incident in an immersive virtual environment

Under what conditions will a bystander intervene to try to stop a violent attack by one person on another? It is generally believed that the greater the size of the crowd of bystanders, the less the chance that any of them will intervene. A complementary model is that social identity is critical as an explanatory variable. For example, when the bystander shares common social identity with the victim the probability of intervention is enhanced, other things being equal. However, it is generally not possible to study such hypotheses experimentally for practical and ethical reasons. Here we show that an experiment that depicts a violent incident at life-size in immersive virtual reality lends support to the social identity explanation. 40 male supporters of Arsenal Football Club in England were recruited for a two-factor between-groups experiment: the victim was either an Arsenal supporter or not (in-group/out-group), and looked towards the participant for help or not during the confrontation. The response variables were the numbers of verbal and physical interventions by the participant during the violent argument. The number of physical interventions had a significantly greater mean in the ingroup condition compared to the out-group. The more that participants perceived that the Victim was looking to them for help the greater the number of interventions in the in-group but not in the out-group. These results are supported by standard statistical analysis of variance, with more detailed findings obtained by a symbolic regression procedure based on genetic programming. Verbal interventions made during their experience, and analysis of post-experiment interview data suggest that in-group members were more prone to confrontational intervention compared to the out-group who were more prone to make statements to try to diffuse the situation

Prevalence of Disorders Recorded in Dogs Attending Primary-Care Veterinary Practices in England

Purebred dog health is thought to be compromised by an increasing occurence of inherited diseases but inadequate prevalence data on common disorders have hampered efforts to prioritise health reforms. Analysis of primary veterinary practice clinical data has been proposed for reliable estimation of disorder prevalence in dogs. Electronic patient record (EPR) data were collected on 148,741 dogs attending 93 clinics across central and south-eastern England. Analysis in detail of a random sample of EPRs relating to 3,884 dogs from 89 clinics identified the most frequently recorded disorders as otitis externa (prevalence 10.2%, 95% CI: 9.1-11.3), periodontal disease (9.3%, 95% CI: 8.3-10.3) and anal sac impaction (7.1%, 95% CI: 6.1-8.1). Using syndromic classification, the most prevalent body location affected was the head-and-neck (32.8%, 95% CI: 30.7-34.9), the most prevalent organ system affected was the integument (36.3%, 95% CI: 33.9-38.6) and the most prevalent pathophysiologic process diagnosed was inflammation (32.1%, 95% CI: 29.8-34.3). Among the twenty most-frequently recorded disorders, purebred dogs had a significantly higher prevalence compared with crossbreds for three: otitis externa (P = 0.001), obesity (P = 0.006) and skin mass lesion (P = 0.033), and popular breeds differed significantly from each other in their prevalence for five: periodontal disease (P = 0.002), overgrown nails (P = 0.004), degenerative joint disease (P = 0.005), obesity (P = 0.001) and lipoma (P = 0.003). These results fill a crucial data gap in disorder prevalence information and assist with disorder prioritisation. The results suggest that, for maximal impact, breeding reforms should target commonly-diagnosed complex disorders that are amenable to genetic improvement and should place special focus on at-risk breeds. Future studies evaluating disorder severity and duration will augment the usefulness of the disorder prevalence information reported herein