552 research outputs found
Improving the Computational Thinking Pedagogical Capabilities of School Teachers
The idea of computational thinking as skills and universal competence which every child should possess emerged last decade and has been gaining traction ever since. This raises a number of questions, including how to integrate computational thinking into the curriculum, whether teachers have computational thinking pedagogical capabilities to teach children, and the important professional development and training areas for teachers. The aim of this paper is to address the strategic issues by illustrating a series of computational thinking workshops for Foundation to Year 8 teachers held at an Australian university. Data indicated that teachers\u27 computational thinking understanding, pedagogical capabilities, technological know-how and confidence can be improved in a relatively short period of time through targeted professional learning
Aspects of radiative K^+_e3 decays
We re-investigate the radiative charged kaon decay K+- --> pi0 e+- nu_e gamma
in chiral perturbation theory, merging the chiral expansion with Low's theorem.
We thoroughly analyze the precision of the predicted branching ratio relative
to the non-radiative decay channel. Structure dependent terms and their impact
on differential decay distributions are investigated in detail, and the
possibility to see effects of the chiral anomaly in this decay channel is
emphasized.Comment: 15 pages, 6 figure
Fecal Viral Load and Norovirus-associated Gastroenteritis
We report the median cDNA viral load of norovirus genogroup II is >100-fold higher than that of genogroup I in the fecal specimens of patients with norovirus-associated gastroenteritis. We speculate that increased cDNA viral load accounts for the higher transmissibility of genogroup II strains through the fecal-oral route
Fecal Viral Concentration and Diarrhea in Norovirus Gastroenteritis
Fecal viral concentrations of 40 patients infected with norovirus genogroup GII.4 correlated with diarrhea duration and frequency of vomiting. Higher viral concentration and older age were independently associated with prolonged diarrhea (>4 days). These findings provide information on the pathogenesis and transmission of norovirus infections
Comparison between light scattering and gravimetric samplers for PM10 mass concentration in poultry and pig houses
The objective of this study was to compare co-located real-time light scattering devices and equivalent gravimetric samplers in poultry and pig houses for PM10 mass concentration, and to develop animal-specific calibration factors for light scattering samplers. These results will contribute to evaluate the comparability of different sampling instruments for PM10, concentrations. Paired DustTrak light scattering device (DustTrak aerosol monitor, TSI, U.S.) and PM10 gravimetric cyclone sampler were used for measuring PM10 mass concentrations during 24 h periods (from noon to noon) inside animal houses. Sampling was conducted in 32 animal houses in the Netherlands, including broilers, broiler breeders, layers in floor and in aviary system, turkeys, piglets, growing-finishing pigs in traditional and low emission housing with dry and liquid feed, and sows in individual and group housing. A total of 119 pairs of 24 h measurements (55 for poultry and 64 for pigs) were recorded and analyzed using linear regression analysis. Deviations between samplers were calculated and discussed. In poultry, cyclone sampler and DustTrak data fitted well to a linear regression, with a regression coefficient equal to 0.41, an intercept of 0.16 mg m(-3) and a correlation coefficient of 0.91 (excluding turkeys). Results in turkeys showed a regression coefficient equal to 1.1 (P = 0.49), an intercept of 0.06 mg m(-3) (P < 0.0001) and a correlation coefficient of 0.98. In pigs, we found a regression coefficient equal to 0.61, an intercept of 0.05 mg m(-3) and a correlation coefficient of 0.84. Measured PM10 concentrations using DustTraks were clearly underestimated (approx. by a factor 2) in both poultry and pig housing systems compared with cyclone pre-separators. Absolute, relative, and random deviations increased with concentration. DustTrak light scattering devices should be self-calibrated to investigate PM10 mass concentrations accurately in animal houses. We recommend linear regression equations as animal-specific calibration factors for DustTraks instead of manufacturer calibration factors, especially in heavily dusty environments such as animal houses. (C) 2015 Elsevier Ltd. All rights reserved.The study was financed by the Dutch Ministry of Economic affairs, Agriculture and Innovation. Authors wish to thank the Campus de Excelencia Internacional of the Universitat Politecnica de Valencia (Spain) for funding Dr. Cambra-Lopez's postdoc contract.Cambra LĂłpez, M.; Winkel, A.; Mosquera, J.; Ogink, NW.; Aarnink, AJA. (2015). Comparison between light scattering and gravimetric samplers for PM10 mass concentration in poultry and pig houses. Atmospheric Environment. 111:20-27. doi:10.1016/j.atmosenv.2015.03.051S202711
A complete 3D numerical study of the effects of pseudoscalar-photon mixing on quasar polarizations
We present the results of three-dimensional simulations of quasar
polarizations in the presence of pseudoscalar-photon mixing in the
intergalactic medium. The intergalactic magnetic field is assumed to be
uncorrelated in wave vector space but correlated in real space. Such a field
may be obtained if its origin is primordial. Furthermore we assume that the
quasars, located at cosmological distances, have negligible initial
polarization. In the presence of pseudoscalar-photon mixing we show, through a
direct comparison with observations, that this may explain the observed large
scale alignments in quasar polarizations within the framework of big bang
cosmology. We find that the simulation results give a reasonably good fit to
the observed data.Comment: 15 pages, 8 figures, significant changes, to appear in EPJ
Rapid emergence and predominance of a broadly recognizing and fast-evolving norovirus GII. 17 variant in late 2014
Norovirus genogroup II genotype 4 (GII.4) has been the predominant cause of viral gastroenteritis since 1996. Here we show that during the winter of 2014â2015, an emergent variant of a previously rare norovirus GII.17 genotype, Kawasaki 2014, predominated in Hong Kong and outcompeted contemporary GII.4 Sydney 2012 in hospitalized cases. GII.17 cases were significantly older than GII.4 cases. Root-to-tip and Bayesian BEAST analyses estimate GII.17 viral protein 1 (VP1) evolves one order of magnitude faster than GII.4 VP1. Residue substitutions and insertion occur in four of five inferred antigenic epitopes, suggesting immune evasion. Sequential GII.4-GII.17 infections are noted, implicating a lack of cross-protection. Virus bound to saliva of secretor histo-blood groups A, B and O, indicating broad susceptibility. This fast-evolving, broadly recognizing and probably immune-escaped emergent GII.17 variant causes severe gastroenteritis and hospitalization across all age groups, including populations who were previously less vulnerable to GII.4 variants; therefore, the global spread of GII.17 Kawasaki 2014 needs to be monitored
Measurement of three-jet differential cross sections d sigma-3jet / d M-3jet in p anti-p collisions at sqrt(s)=1.96 TeV
We present the first measurement of the inclusive three-jet differential
cross section as a function of the invariant mass of the three jets with the
largest transverse momenta in an event in p anti-p collisions at sqrt(s) = 1.96
TeV. The measurement is made in different rapidity regions and for different
jet transverse momentum requirements and is based on a data set corresponding
to an integrated luminosity of 0.7 fb^{-1} collected with the D0 detector at
the Fermilab Tevatron Collider. The results are used to test the three-jet
matrix elements in perturbative QCD calculations at next-to-leading order in
the strong coupling constant. The data allow discrimination between
parametrizations of the parton distribution functions of the proton.Comment: 10 pages, 4 figures, 2 tables, submitted to Phys. Lett. B, corrected
chi2 values for NNPD
\psi(2S) Decays into \J plus Two Photons
Using \gamma \gamma J/\psi, J/\psi \ra e^+ e^- and events
from a sample of \psip decays collected with the BESII
detector, the branching fractions for \psip\ra \pi^0\J, \eta\J, and
\psi(2S)\ar\gamma\chi_{c1},\gamma\chi_{c2}\ar\gamma\gamma\jpsi are measured
to be B(\psip\ra \pi^0\J) = (1.43\pm0.14\pm0.13)\times 10^{-3}, B(\psip\ra
\eta\J) = (2.98\pm0.09\pm0.23)%,
B(\psi(2S)\ar\gamma\chi_{c1}\ar\gamma\gamma\jpsi) = (2.81\pm0.05\pm 0.23)%,
and B(\psi(2S)\ar\gamma\chi_{c2}\ar\gamma\gamma\jpsi) = (1.62\pm0.04\pm
0.12)%.Comment: 7 pages, 6 figures. submitted to Phys. Rev.
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