2,679 research outputs found
Food hygiene knowledge in adolescents and young adults
Purpose â The purpose of this paper is to utilise the comprehensive Food Safety Knowledge Instrument to compare food hygiene knowledge across a population of high school and university students in Australia and the UK. Design/methodology/approach â In total, 475 students from secondary schools and universities in Australia and the UK took part in a survey, which included a Food Safety Knowledge Instrument and demographic items. Findings â Food safety knowledge was generally very low. High school students had a mean score of only 38 per cent, while university students just reached a âpassâ with a mean of 54 per cent. Demographics accounted for 41 per cent of variance in food knowledge scores. Female gender, being at university rather than high school, and living out of home rather than with parents were associated with greater food knowledge. Residing in Australia rather than the UK and being older were also associated with greater knowledge; however, these findings were subsumed by education group. Socio-economic status was not a significant predictor of food knowledge. Practical implications â Identifying demographic and cultural differences in food knowledge can help to identify at-risk populations to better target in theory and knowledge-based interventions. Originality/value â This study is the first to apply the knowledge instrument in an Australian population. Understanding the baseline knowledge in this population is an important first step at developing effective interventions for food safety
Evolutionary History and Phylodynamics of Influenza A and B Neuraminidase (NA) Genes Inferred from Large- Scale Sequence Analyses
Background: Influenza neuraminidase (NA) is an important surface glycoprotein and plays a vital role in viral replication and drug development. The NA is found in influenza A and B viruses, with nine subtypes classified in influenza A. The complete knowledge of influenza NA evolutionary history and phylodynamics, although critical for the prevention and control of influenza epidemics and pandemics, remains lacking.
Methodology/Principal findings: Evolutionary and phylogenetic analyses of influenza NA sequences using Maximum Likelihood and Bayesian MCMC methods demonstrated that the divergence of influenza viruses into types A and B occurred earlier than the divergence of influenza A NA subtypes. Twenty-three lineages were identified within influenza A, two lineages were classified within influenza B, and most lineages were specific to host, subtype or geographical location. Interestingly, evolutionary rates vary not only among lineages but also among branches within lineages. The estimated tMRCAs of influenza lineages suggest that the viruses of different lineages emerge several months or even years before their initial detection. The dN/dS ratios ranged from 0.062 to 0.313 for influenza A lineages, and 0.257 to 0.259 for influenza B lineages. Structural analyses revealed that all positively selected sites are at the surface of the NA protein, with a number of sites found to be important for host antibody and drug binding.
Conclusions/Significance: The divergence into influenza type A and B from a putative ancestral NA was followed by the divergence of type A into nine NA subtypes, of which 23 lineages subsequently diverged. This study provides a better understanding of influenza NA lineages and their evolutionary dynamics, which may facilitate early detection of newly emerging influenza viruses and thus improve influenza surveillance
A General Catalogue of Molecular Hydrogen Emission-Line Objects (MHOs) in Outflows from Young Stars
We present a catalogue of Molecular Hydrogen emission-line Objects (MHOs) in
outflows from young stars, most of which are embedded. All objects are
identified in the near-infrared lines of molecular hydrogen, all reside in the
Milky Way, and all are associated with jets or molecular outflows from young
stars. Objects in both low and high-mass star forming regions are included.
This catalogue complements the existing database of Herbig-Haro objects;
indeed, for completeness, HH objects that are detected in H2 emission are
included in the MHO catalogue.Comment: 8 Pages, 5 figures. Accepted for publication in A&A. Searchable
catalogue/Data tables available from http://www.jach.hawaii.edu/UKIRT/MHCat
Random Walks for Spike-Timing Dependent Plasticity
Random walk methods are used to calculate the moments of negative image
equilibrium distributions in synaptic weight dynamics governed by spike-timing
dependent plasticity (STDP). The neural architecture of the model is based on
the electrosensory lateral line lobe (ELL) of mormyrid electric fish, which
forms a negative image of the reafferent signal from the fish's own electric
discharge to optimize detection of sensory electric fields. Of particular
behavioral importance to the fish is the variance of the equilibrium
postsynaptic potential in the presence of noise, which is determined by the
variance of the equilibrium weight distribution. Recurrence relations are
derived for the moments of the equilibrium weight distribution, for arbitrary
postsynaptic potential functions and arbitrary learning rules. For the case of
homogeneous network parameters, explicit closed form solutions are developed
for the covariances of the synaptic weight and postsynaptic potential
distributions.Comment: 18 pages, 8 figures, 15 subfigures; uses revtex4, subfigure, amsmat
Genetic Stasis of Dominant West Nile Virus Genotype, Houston, Texas
The accumulation and fixation of mutations in West Nile virus (WNV) led to the emergence of a dominant genotype throughout North America. Subsequent analysis of 44 isolates, including 19 new sequences, from Houston, Texas, suggests that WNV has reached relative genetic stasis at the local level in recent years
On the segmentation and classification of hand radiographs
This research is part of a wider project to build predictive models of bone age using hand radiograph images. We examine ways of finding the outline of a hand from an X-ray as the first stage in segmenting the image into constituent bones. We assess a variety of algorithms including contouring, which has not previously been used in this context. We introduce a novel ensemble algorithm for combining outlines using two voting schemes, a likelihood ratio test and dynamic time warping (DTW). Our goal is to minimize the human intervention required, hence we investigate alternative ways of training a classifier to determine whether an outline is in fact correct or not. We evaluate outlining and classification on a set of 1370 images. We conclude that ensembling with DTW improves performance of all outlining algorithms, that the contouring algorithm used with the DTW ensemble performs the best of those assessed, and that the most effective classifier of hand outlines assessed is a random forest applied to outlines transformed into principal components
Vacuum System Performance for the First Sextant Test of the Relativistic Heavy Ion Collider
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