1,714 research outputs found
Aerobic capacity, activity levels and daily energy expenditure in male and female adolescents of the kenyan nandi sub-group
The relative importance of genetic and socio-cultural influences contributing to the success of east Africans in endurance athletics remains unknown in part because the pre-training phenotype of this population remains incompletely assessed. Here cardiopulmonary fitness, physical activity levels, distance travelled to school and daily energy expenditure in 15 habitually active male (13.9Âą1.6 years) and 15 habitually active female (13.9Âą1.2) adolescents from a rural Nandi primary school are assessed. Aerobic capacity ([Formula: see text]) was evaluated during two maximal discontinuous incremental exercise tests; physical activity using accelerometry combined with a global positioning system; and energy expenditure using the doubly labelled water method. The [Formula: see text] of the male and female adolescents were 73.9Âą5.7 ml(.) kg(-1.) min(-1) and 61.5Âą6.3 ml(.) kg(-1.) min(-1), respectively. Total time spent in sedentary, light, moderate and vigorous physical activities per day was 406Âą63 min (50% of total monitored time), 244Âą56 min (30%), 75Âą18 min (9%) and 82Âą30 min (10%). Average total daily distance travelled to and from school was 7.5Âą3.0 km (0.8-13.4 km). Mean daily energy expenditure, activity-induced energy expenditure and physical activity level was 12.2Âą3.4 MJ(.) day(-1), 5.4Âą3.0 MJ(.) day(-1) and 2.2Âą0.6. 70.6% of the variation in [Formula: see text] was explained by sex (partial R(2)â=â54.7%) and body mass index (partial R(2)â=â15.9%). Energy expenditure and physical activity variables did not predict variation in [Formula: see text] once sex had been accounted for. The highly active and energy-demanding lifestyle of rural Kenyan adolescents may account for their exceptional aerobic fitness and collectively prime them for later training and athletic success
Cooling Common Spaces in Densifying Urban Environments
The research promotes a new approach to thinking about urban liveability in warming cities by identifying cooling patterns for outdoor common spaces
Charged pion form factor between Q^2=0.60 and 2.45 GeV^2. II. Determination of, and results for, the pion form factor
The charged pion form factor, Fpi(Q^2), is an important quantity which can be
used to advance our knowledge of hadronic structure. However, the extraction of
Fpi from data requires a model of the 1H(e,e'pi+)n reaction, and thus is
inherently model dependent. Therefore, a detailed description of the extraction
of the charged pion form factor from electroproduction data obtained recently
at Jefferson Lab is presented, with particular focus given to the dominant
uncertainties in this procedure. Results for Fpi are presented for
Q^2=0.60-2.45 GeV^2. Above Q^2=1.5 GeV^2, the Fpi values are systematically
below the monopole parameterization that describes the low Q^2 data used to
determine the pion charge radius. The pion form factor can be calculated in a
wide variety of theoretical approaches, and the experimental results are
compared to a number of calculations. This comparison is helpful in
understanding the role of soft versus hard contributions to hadronic structure
in the intermediate Q^2 regime.Comment: 18 pages, 11 figure
Charged pion form factor between =0.60 and 2.45 GeV. I. Measurements of the cross section for the H() reaction
Cross sections for the reaction H() were measured in Hall
C at Thomas Jefferson National Accelerator Facility (JLab) using the CEBAF
high-intensity, continous electron beam in order to determine the charged pion
form factor. Data were taken for central four-momentum transfers ranging from
=0.60 to 2.45 GeV at an invariant mass of the virtual photon-nucleon
system of =1.95 and 2.22 GeV. The measured cross sections were separated
into the four structure functions , , , and
. The various parts of the experimental setup and the analysis
steps are described in detail, including the calibrations and systematic
studies, which were needed to obtain high precision results. The different
types of systematic uncertainties are also discussed. The results for the
separated cross sections as a function of the Mandelstam variable at the
different values of are presented. Some global features of the data are
discussed, and the data are compared with the results of some model
calculations for the reaction H().Comment: 26 pages, 23 figure
Separated Response Function Ratios in Exclusive, Forward pi^{+/-} Electroproduction
The study of exclusive electroproduction on the nucleon,
including separation of the various structure functions, is of interest for a
number of reasons. The ratio is
sensitive to isoscalar contamination to the dominant isovector pion exchange
amplitude, which is the basis for the determination of the charged pion form
factor from electroproduction data. A change in the value of
from unity at small , to 1/4 at
large , would suggest a transition from coupling to a (virtual) pion to
coupling to individual quarks. Furthermore, the mentioned ratios may show an
earlier approach to pQCD than the individual cross sections. We have performed
the first complete separation of the four unpolarized electromagnetic structure
functions above the dominant resonances in forward, exclusive
electroproduction on the deuteron at central values of 0.6, 1.0, 1.6
GeV at =1.95 GeV, and GeV at =2.22 GeV. Here, we
present the and cross sections, with emphasis on and , and
compare them with theoretical calculations. Results for the separated ratio
indicate dominance of the pion-pole diagram at low , while results
for are consistent with a transition between pion knockout and quark
knockout mechanisms.Comment: 6 pages, 3 figure
Thyroid disease is a favorable prognostic factor in achieving sustained virologic response in chronic hepatitis C undergoing combination therapy: A nested case control study
<p>Abstract</p> <p>Background</p> <p>Interferon-Îą in combination with ribavirin is the current gold standard for treatment of chronic hepatitis C. It is unknown if the development of autoimmune thyroid disease (TD) during treatment confers an improved chance of achieving sustained virologic response. The aim of this study is to assess the chance of achieving sustained virologic response (SVR) in patients who developed TD during treatment when compared with those who did not.</p> <p>Methods</p> <p>We performed a tertiary hospital-based retrospective nested case-control analysis of 19 patients treated for hepatitis C who developed thyroid disease, and 76 controls (matched for age, weight, gender, cirrhosis and aminotransferase levels) who did not develop TD during treatment. Multivariate logistic-regression models were used to compare cases and controls.</p> <p>Results</p> <p>The development of TD was associated with a high likelihood of achieving SVR (odds ratio, 6.0; 95% confidence interval, 1.5 to 24.6) for the pooled group containing all genotypes. The likelihood of achieving SVR was increased in individuals with genotype 1 HCV infection who developed TD (odds ratio, 5.2; 95% confidence interval, 1.2 to 22.3), and all genotype 3 patients who developed TD achieved SVR.</p> <p>Conclusions</p> <p>Development of TD during treatment for hepatitis C infection is associated with a significantly increased chance of achieving SVR. The pathophysiogical mechanisms for this observation remain to be determined.</p> <p>Trial Registration</p> <p><it>The Australian New Zealand Clinical Trials Registry (ANZCTR)</it>: <a href="http://www.anzctr.org.au/ACTRB12610000830099.aspx">ACTRB12610000830099</a></p
A Helicity-Based Method to Infer the CME Magnetic Field Magnitude in Sun and Geospace: Generalization and Extension to Sun-Like and M-Dwarf Stars and Implications for Exoplanet Habitability
Patsourakos et al. (Astrophys. J. 817, 14, 2016) and Patsourakos and
Georgoulis (Astron. Astrophys. 595, A121, 2016) introduced a method to infer
the axial magnetic field in flux-rope coronal mass ejections (CMEs) in the
solar corona and farther away in the interplanetary medium. The method, based
on the conservation principle of magnetic helicity, uses the relative magnetic
helicity of the solar source region as input estimates, along with the radius
and length of the corresponding CME flux rope. The method was initially applied
to cylindrical force-free flux ropes, with encouraging results. We hereby
extend our framework along two distinct lines. First, we generalize our
formalism to several possible flux-rope configurations (linear and nonlinear
force-free, non-force-free, spheromak, and torus) to investigate the dependence
of the resulting CME axial magnetic field on input parameters and the employed
flux-rope configuration. Second, we generalize our framework to both Sun-like
and active M-dwarf stars hosting superflares. In a qualitative sense, we find
that Earth may not experience severe atmosphere-eroding magnetospheric
compression even for eruptive solar superflares with energies ~ 10^4 times
higher than those of the largest Geostationary Operational Environmental
Satellite (GOES) X-class flares currently observed. In addition, the two
recently discovered exoplanets with the highest Earth-similarity index, Kepler
438b and Proxima b, seem to lie in the prohibitive zone of atmospheric erosion
due to interplanetary CMEs (ICMEs), except when they possess planetary magnetic
fields that are much higher than that of Earth.Comment: http://adsabs.harvard.edu/abs/2017SoPh..292...89
Multicomponent powder injection molding as method for mass production, joining, and material development for tungsten armour materials
Standalone vertex ďŹnding in the ATLAS muon spectrometer
A dedicated reconstruction algorithm to find decay vertices in the ATLAS muon spectrometer is presented. The algorithm searches the region just upstream of or inside the muon spectrometer volume for multi-particle vertices that originate from the decay of particles with long decay paths. The performance of the algorithm is evaluated using both a sample of simulated Higgs boson events, in which the Higgs boson decays to long-lived neutral particles that in turn decay to bbar b final states, and pp collision data at âs = 7 TeV collected with the ATLAS detector at the LHC during 2011
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