Muscular and non-muscular contributions to maximum power cycling in children and adults: implications for developmental motor control

This article is available open access through the publisher’s website at the link below.During submaximal cycling, children demonstrate a different distribution between muscular and non-muscular (gravitational and motion-dependent) forces when compared with adults. This is partly due to anthropometric differences. In this study, we tested the hypothesis that during maximum power cycling, children would construct the task (in terms of the distribution between muscular and non-muscular pedal power) similarly to adults. Eleven children (aged 8–9 years) and 13 adults (aged 20–40 years) performed a maximal isokinetic cycling task over 3 s at 115 r.p.m. Multivariate analyses of variance revealed no significant differences in normalized maximum, minimum and average positive non-muscular pedal power between children and adults (Wilks' λ=0.755, F3,20=2.17, P=0.124). Thus, maximum cycling is a developmental `self-scaling' task and age-related differences in muscular power production are not confounded by differences in anthropometry. This information is useful to researchers who wish to differentiate between muscular and non-muscular power when studying developmental motor control. In addition to the similarities in the distribution between muscular and non-muscular pedal power, we found age-related differences in the relative joint power contributions to total pedal power. In children, a significantly smaller proportion of total pedal power was generated at the ankle joint (6.1±5.4% for children and 12.6±3.2% for adults), whilst relatively more power was generated at the knee and hip joints. These results suggest that intermuscular coordination may be contributing to children's limits in maximum power production during multi-joint tasks

Reaction kinetics of CaOH with H and O₂, and O₂CaOH with O: implications for the atmospheric chemistry of meteoric calcium

The ablation of cosmic dust particles entering the Earth’s upper atmosphere produces a layer of Ca atoms around 90 km. Here we present a set of kinetic experiments designed to understand the nature of the Ca molecular reservoirs on the underside of the layer. CaOH was produced by laser ablation of a Ca target in the fast flow tube, and detected by non-resonant laser induced fluorescence, probing the D(2Σ+)←X(2Σ1) transition at 346.9 nm. The following rate constants were measured (at 298 K): k(CaOH + H → Ca + H2O) = (1.04 ± 0.24) × 10-10 cm3 molecule-1 s-1, k(CaOH + O → CaO + OH) < 1 × 10-11 cm3 molecule 1 s-1 and k(CaOH + O2 → O2CaOH; 1 Torr) = (5.9 ± 1.8) × 10-11 cm3 molecule-1 s-1 (uncertainty at 2σ level of confidence). The recycling of CaOH from reaction between O2CaOH and O proceeds with an effective rate constant of keff(O2CaOH + O → CaOH + products, 298 K) = 〖"2.8" 〗_(-"1.2" )^"+2.0" × 10-10 cm3 molecule-1 s-1). Master equation modelling of the CaOH + O2 kinetics is used to extrapolate to mesospheric temperatures and pressures. The results suggest that formation of O2CaOH slows down the conversion of CaOH to atomic Ca via reaction with atomic H, and O2CaOH is likely to be a long-lived reservoir species on the underside of the Ca layer and a building block of meteoric smoke particles

Novel sol–gel preparation of (PO)–(CaO)–(NaO)–(TiO) bioresorbable glasses (X = 0.05, 0.1, and 0.15)

Quaternary phosphate-based glasses in the PO–CaO–NaO–TiO system with a fixed PO and CaO content of 40 and 25 mol% respectively have been successfully synthesised via sol–gel method and bulk, transparent samples were obtained. The structure, elemental proportion, and thermal properties of stabilised sol–gel glasses have been characterised using X-ray diffraction (XRD), energy dispersive X-ray spectroscopy (EDX), P nuclear magnetic resonance (P NMR), titanium K-edge X-ray absorption near-edge structure (XANES), fourier transform infrared (FTIR) spectroscopy, and differential thermal analysis (DTA). The XRD results confirmed the amorphous nature for all stabilized sol–gel derived glasses. The EDX result shows the relatively low loss of phosphorus during the sol–gel process and Ti K-edge XANES confirmed titanium in the glass structure is in mainly six-fold coordination environment. The P NMR and FTIR results revealed that the glass structure consist of mainly Q and Q phosphate units and the Ti cation was acting as a cross-linking between phosphate units. In addition DTA results confirmed a decrease in the glass transition and crystallisation temperature with increasing NaO content. Ion release studies also demonstrated a decrease in degradation rates with increasing TiO content therefore supporting the use of these glasses for biomedical applications that require a degree of control over glass degradation. These sol–gel glasses also offer the potential to incorporate proactive molecules for drug delivery application due to the low synthesis temperature employed

Near-infrared photometry of WISE J085510.74-071442.5

Indexación: Web of ScienceAims. We aim at obtaining near-infrared photometry and deriving the mass, age, temperature, and surface gravity of WISE J085510.74 071442.5 (J0855 0714), which is the coolest object beyond the solar system currently known. Methods. We used publicly available data from the archives of the Hubble Space Telescope (HST) and the Very Large Telescope (VLT) to determine the emission of this source at 1.153 mu m (F110W) and 1.575 mu m (CH4-o ff). J0855 0714 was detected at both wavelengths with a signal-to-noise ratio of approximate to 10 (F110W) and approximate to 4 (CH4-off) at the peak of the corresponding point-spread-functions. Results. This is the first detection of J0855 0714 in the H-band wavelengths. We measured 26.31 +/- 0.10 and 23.22 +/- 0.35 mag in F110W and CH4-o ff (Vega system). J0855 0714 remains unresolved in the HST images that have a spatial resolution of 0.22 0 0. Companions at separations of 0.5 AU (similar mass and brightness) and at similar to 1 AU approximate to 1 mag fainter in the F110W filter) are discarded. By combining the new data with published photometry, including non-detections, we build the spectral energy distribution of J0855 0714 from 0.89 through 22.09 mu m, and contrast it against current solar-metallicity models of planetary atmospheres. We determine that the best spectral fit yields a temperature of 225 250 K, a bolometric luminosity of log L/L-circle dot = 8 : 57, and a high surface gravity of log g = 5 : 0 (cm s(2)), which suggests an old age although a gravity this high is not fully compatible with evolutionary models. After comparing our data with the cooling theory for brown dwarfs and planets, we infer a mass in the interval 2 10 MJup for ages of 1 12 Gyr and high atmospheric gravities of log g greater than or similar to 3.5 (cm s(2)). If it had the age of the Sun, J0855 0714 would be a approximate to 5-M-Jup free-floating planetary-mass object. Conclusions. J0855 0714 meets the mass values previously determined for free-floating planetary-mass objects discovered in starforming regions and young stellar clusters. Based on extrapolations of the substellar mass functions of young clusters to the field, as many J0855 0714-like objects as M5-L2 stars may be expected to populate the solar neighborhood.http://www.aanda.org/articles/aa/pdf/2016/08/aa28662-16.pd

A Proof Strategy Language and Proof Script Generation for Isabelle/HOL

We introduce a language, PSL, designed to capture high level proof strategies in Isabelle/HOL. Given a strategy and a proof obligation, PSL's runtime system generates and combines various tactics to explore a large search space with low memory usage. Upon success, PSL generates an efficient proof script, which bypasses a large part of the proof search. We also present PSL's monadic interpreter to show that the underlying idea of PSL is transferable to other ITPs.Comment: This paper has been submitted to CADE2

Efficient HTTP based I/O on very large datasets for high performance computing with the libdavix library

Remote data access for data analysis in high performance computing is commonly done with specialized data access protocols and storage systems. These protocols are highly optimized for high throughput on very large datasets, multi-streams, high availability, low latency and efficient parallel I/O. The purpose of this paper is to describe how we have adapted a generic protocol, the Hyper Text Transport Protocol (HTTP) to make it a competitive alternative for high performance I/O and data analysis applications in a global computing grid: the Worldwide LHC Computing Grid. In this work, we first analyze the design differences between the HTTP protocol and the most common high performance I/O protocols, pointing out the main performance weaknesses of HTTP. Then, we describe in detail how we solved these issues. Our solutions have been implemented in a toolkit called davix, available through several recent Linux distributions. Finally, we describe the results of our benchmarks where we compare the performance of davix against a HPC specific protocol for a data analysis use case.Comment: Presented at: Very large Data Bases (VLDB) 2014, Hangzho

Novel sialic acid derivatives lock open the 150-loop of an influenza A virus group-1 sialidase

This work was supported by the Medical Research Council and the Scottish Funding Council.Influenza virus sialidase has an essential role in the virus’ life cycle. Two distinct groups of influenza A virus sialidases have been established, that differ in the flexibility of the ‘150-loop’, providing a more open active site in the apo form of the group-1 compared to group-2 enzymes. In this study we show, through a multidisciplinary approach, that novel sialic acid-based derivatives can exploit this structural difference and selectively inhibit the activity of group-1 sialidases. We also demonstrate that group-1 sialidases from drug-resistant mutant influenza viruses are sensitive to these designed compounds. Moreover, we have determined, by protein X-ray crystallography, that these inhibitors lock open the group-1 sialidase flexible 150-loop, in agreement with our molecular modelling prediction. This is the first direct proof that compounds may be developed to selectively target the pandemic A/H1N1, avian A/H5N1 and other group-1 sialidase-containing viruses, based on an open 150-loop conformation of the enzyme.Publisher PDFPeer reviewe

The role of mobile technology in promoting social inclusion among adults with intellectual disabilities

Background: Mobile technology has the potential to assist adults with intellectual disabilities to initiate and maintain social connections in important areas of their lives, such as family, friends and work/volunteering. Method: The present study investigated how specific aspects of mobile device/app use are associated with the social inclusion of people with intellectual disabilities. The study also examined what background attributes were associated with particular patterns of mobile device/app use and social inclusion. Results: The findings revealed that the use of mobile technology among adults with intellectual disabilities was positively associated with their social inclusion with family, friends and work/volunteering. There were also some key background attributes associated with participants’ use of mobile technology and the extent to which mobile technology assisted their social inclusion. Conclusions: Implications for practice and policy are discussed

Central Exclusive Production in QCD

We investigate the theoretical description of the central exclusive production process, h1+h2 -> h1+X+h2. Taking Higgs production as an example, we sum logarithmically enhanced corrections appearing in the perturbation series to all orders in the strong coupling. Our results agree with those originally presented by Khoze, Martin and Ryskin except that the scale appearing in the Sudakov factor, mu=0.62 \sqrt{\hat{s}}, should be replaced with mu=\sqrt{\hat{s}}, where \sqrt{\hat{s}} is the invariant mass of the centrally produced system. We confirm this result using a fixed-order calculation and show that the replacement leads to approximately a factor 2 suppression in the cross-section for central system masses in the range 100-500 GeV.Comment: 41 pages, 19 figures; minor typos fixed; version published in JHE