1,114 research outputs found
Study reveals effect of aluminum on saturation moment of Fe-Ni alloys
Study of saturation magnetization, important in the investigation of the electronic structure of alloys, reveals the effect of aluminum on the saturation moments of iron-nickel alloys. The saturation magnetizations were extrapolated to the absolute zero of temperature for calculating average atomic moments
The maximum number of minimal codewords in an code
Upper and lower bounds are derived for the quantity in the title, which is
tabulated for modest values of and An application to graphs with many
cycles is given.Comment: 6 pp. Submitte
Statistical Analysis Plan: Low Traffic Neighbourhoods in London: Interrupted time series analysis of sensor count data
This document is a statistical analysis plan for the NIHR-funded study into Low Traffic Neighbourhoods in London. It outlines the methodological approach (including data cleaning, anomaly detection, imputation and statistical analysis) associated with automated sensor data collected as part of the project. It gives particular detail to the interrupted time series method that, dependent on data availability and suitability, should form a significant part of the analysis of sensor data
Missoula Case Study: Direct Impact of Visitor Spending on a Local Economy
Examines the direct impact of visitor spending on Missoula County, Montana. The methodology explores the application of the Travel and Tourism Satellite Accounts (TTSA\u27s) to county level economic information in an attempt to develop a simplified method of estimating visitor spending at the local level. For this study, visitor spending reflects both Montana residents who reside outside of Missoula County as well as nonresident visitors to Montana
Extending a perfect matching to a Hamiltonian cycle
Graph TheoryInternational audienceRuskey and Savage conjectured that in the d-dimensional hypercube, every matching M can be extended to a Hamiltonian cycle. Fink verified this for every perfect matching M, remarkably even if M contains external edges. We prove that this property also holds for sparse spanning regular subgraphs of the cubes: for every d ≥7 and every k, where 7 ≤k ≤d, the d-dimensional hypercube contains a k-regular spanning subgraph such that every perfect matching (possibly with external edges) can be extended to a Hamiltonian cycle. We do not know if this result can be extended to k=4,5,6. It cannot be extended to k=3. Indeed, there are only three 3-regular graphs such that every perfect matching (possibly with external edges) can be extended to a Hamiltonian cycle, namely the complete graph on 4 vertices, the complete bipartite 3-regular graph on 6 vertices and the 3-cube on 8 vertices. Also, we do not know if there are graphs of girth at least 5 with this matching-extendability property
Exercise Selectively Mobilises Skin-Homing Effector CD8+ T Cells and Natural Killer Cells into Peripheral Blood.
Introduction: Acute exercise induces a transient mobilisation of lymphocyes into peripheral blood that is largely comprised of CD8+ T cells and natural killer (NK) cells. The magnitude of this response is dependent on the differentiation status of these lymphocyte subsets, thus cells with a capacity to initiate rapid effector function (i.e., cytokine secretion and target killing) exhibit the largest changes in response to exercise. It is hypothesised that the effector cells preferentially mobilised into the bloodstream have high tissue-migrating potential, however, the origin of these cells, and their potential homing destination(s) following exercise has not been established in humans. Accordingly, this study investigated whether CD8+ and NK cell subsets expressing the cutaneous lymphocte antigen (CLA) – a molecule expressed on skin-associated memory lymphocytes (≤ 20% CD8+ T cells and ≤ 50%NK cells) that binds to endothelial cell leukocyte adhesion molecule 1 (ELAM-1) – were selectively mobilised in response to acute exercise. Methods: Ten healthy males (mean ± SD age: 22 ± 3 yrs) completed two different exercise sessions: high-intensity continuous cycling (CC; 85% at HRPeak for 30 mins) and high-intensity interval training (HIIT; 90% of HRpeak 10 x 1 min repetitions with 1 min rest intervals). Blood was taken before, immediately- and 30 min post-exercise for cryo-preservation of peripheral blood mononuclear cells. CD8+ subsets were classified into naive (NA; CD45RA+CCR7+), central memory (CM; CD45RA−CCR7+), effector-memory (EM; CD45RA−CCR7−) and CD45RA- expressing effector-memory cells (EMRA; CD45RA+CCR7−). In parallel, CD56bright ‘regulatory’ and CD56dim ‘cytotoxic’ NK subsets were identified using CD56 and CD16. Lymphocyte subpopulations were examined for CLA expression. Results: The number of CLA+CD8+ cells increased in response to both exercise modes. This observation was driven by a preferential mobilisation of effector-memory CLA+CD8+ T cells, as shown by the percentage change in cell number from baseline to exercise: EMRA (CC 244%, HIIT 86%) \u3e EM (CC 142%, HIIT 75%) \u3e CM (CC 104%, HIIT 51%) \u3e naive (CC 82%, HIIT 34%). Within the NK cell pool, CLA+CD56dim cells (CC 520%, HIIT 326%) were mobilised to a greater extent than CLA+CD56bright cells (CC 180%, HIIT 129%). 30-min post-exercise, there was a reduction in the number of CLA+ cells compared to pre-exercise values. Conclusion: This is the first study to demonstrate a selective mobilisation of skin-homing lymphocytes during exercise, suggesting that exercise redistributes effector cells to peripheral tissue, contributing to immune-surveillance
Accurate structure factors from pseudopotential methods
Highly accurate experimental structure factors of silicon are available in
the literature, and these provide the ideal test for any \emph{ab initio}
method for the construction of the all-electron charge density. In a recent
paper [J. R. Trail and D. M. Bird, Phys. Rev. B {\bf 60}, 7863 (1999)] a method
has been developed for obtaining an accurate all-electron charge density from a
first principles pseudopotential calculation by reconstructing the core region
of an atom of choice. Here this method is applied to bulk silicon, and
structure factors are derived and compared with experimental and Full-potential
Linear Augmented Plane Wave results (FLAPW). We also compare with the result of
assuming the core region is spherically symmetric, and with the result of
constructing a charge density from the pseudo-valence density + frozen core
electrons. Neither of these approximations provide accurate charge densities.
The aspherical reconstruction is found to be as accurate as FLAPW results, and
reproduces the residual error between the FLAPW and experimental results.Comment: 6 Pages, 3 figure
Low volume–high intensity interval exercise elicits antioxidant and anti-inflammatory effects in humans
The purpose of the present study was to compare acute changes in oxidative stress and inflammation in response to steady state and low volume, high intensity interval exercise (LV-HIIE). Untrained healthy males (n = 10, mean ± s: age 22 ± 3 years; VO2MAX 42.7 ± 5.0 ml · kg−1 · min−1) undertook three exercise bouts: a bout of LV-HIIE (10 × 1 min 90% VO2MAX intervals) and two energy-matched steady-state cycling bouts at a moderate (60% VO2MAX; 27 min, MOD) and high (80% VO2MAX; 20 min, HIGH) intensity on separate days. Markers of oxidative stress, inflammation and physiological stress were assessed before, at the end of exercise and 30 min post-exercise (post+30). At the end of all exercise bouts, significant changes in lipid hydroperoxides (LOOH) and protein carbonyls (PCs) (LOOH (nM): MOD +0.36; HIGH +3.09; LV-HIIE +5.51 and PC (nmol · mg−1 protein): MOD −0.24; HIGH −0.11; LV-HIIE −0.37) were observed. Total antioxidant capacity (TAC) increased post+30, relative to the end of all exercise bouts (TAC (µM): MOD +189; HIGH +135; LV-HIIE +102). Interleukin (IL)-6 and IL-10 increased post+30 in HIGH and LV-HIIE only (P < 0.05). HIGH caused the greatest lymphocytosis, adrenaline and cardiovascular response (P < 0.05). At a reduced energy cost and physiological stress, LV-HIIE elicited similar cytokine and oxidative stress responses to HIGH
Ab initio study of the volume dependence of dynamical and thermodynamical properties of silicon
Motivated by the negative thermal expansion observed for silicon between 20 K
and 120 K, we present first an ab initio study of the volume dependence of
interatomic force constants, phonon frequencies of TA(X) and TA(L) modes, and
of the associated mode Gruneisen parameters. The influence of successive
nearest neighbors shells is analysed. Analytical formulas, taking into account
interactions up to second nearest neighbors, are developped for phonon
frequencies of TA(X) and TA(L) modes and the corresponding mode Gruneisen
parameters. We also analyze the volume and pressure dependence of various
thermodynamic properties (specific heat, bulk modulus, thermal expansion), and
point out the effect of the negative mode Gruneisen parameters of the acoustic
branches on these properties. Finally, we present the evolution of the mean
square atomic displacement and of the atomic temperature factor with the
temperature for different volumes, for which the anomalous effects are even
greater.Comment: 24 pages, Revtex 3.0, 11 figures, accepted for publication in Phys.
Rev.
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