1,266 research outputs found
Children’s experiences of domestic violence: A teaching and training challenge
In this chapter we explore the complexities of training and teaching students and practitioners about children’s experiences of domestic violence. The research conducted on children’s experiences has tended to focus on these negative outcomes, representing these children as damaged and vulnerable (Callaghan and Alexander, 2015; Øverlien, 2013). Such research outlines that children have elevated lifelong risk of mental health difficulties (Bogat et al., 2006; Lamers-Winkelman et al., 2012; Stover, 2005); interpersonal difficulties (Baldry, 2003; Holmes, 2013; Renner and Slack, 2006); educational difficulties and educational drop out (Byrne and Taylor, 2007), and physical health problems (Bair-Merritt et al., 2006). Despite this research representation of children as vulnerable and damaged, services for children who experience domestic violence are often underdeveloped and underfunded (Statham, 2004; Willis et al., 2010), typically additional to adult domestic abuse services, for instance as part of the services offered in shelters
Non-linear Response of the trap model in the aging regime : Exact results in the strong disorder limit
We study the dynamics of the one dimensional disordered trap model presenting
a broad distribution of trapping times , when an
external force is applied from the very beginning at , or only after a
waiting time , in the linear as well as in the non-linear response regime.
Using a real-space renormalization procedure that becomes exact in the limit of
strong disorder , we obtain explicit results for many observables,
such as the diffusion front, the mean position, the thermal width, the
localization parameters and the two-particle correlation function. In
particular, the scaling functions for these observables give access to the
complete interpolation between the unbiased case and the directed case.
Finally, we discuss in details the various regimes that exist for the averaged
position in terms of the two times and the external field.Comment: 27 pages, 1 eps figur
Polarons with a twist
We consider a polaron model where molecular \emph{rotations} are important.
Here, the usual hopping between neighboring sites is affected directly by the
electron-phonon interaction via a {\em twist-dependent} hopping amplitude. This
model may be of relevance for electronic transport in complex molecules and
polymers with torsional degrees of freedom, such as DNA, as well as in
molecular electronics experiments where molecular twist motion is significant.
We use a tight-binding representation and find that very different polaronic
properties are already exhibited by a two-site model -- these are due to the
nonlinearity of the restoring force of the twist excitations, and of the
electron-phonon interaction in the model. In the adiabatic regime, where
electrons move in a {\em low}-frequency field of twisting-phonons, the
effective splitting of the energy levels increases with coupling strength. The
bandwidth in a long chain shows a power-law suppression with coupling, unlike
the typical exponential dependence due to linear phonons.Comment: revtex4 source and one eps figur
Low Reynolds number hydrodynamics of asymmetric, oscillating dumbbell pairs
Active dumbbell suspensions constitute one of the simplest model system for
collective swimming at low Reynolds number. Generalizing recent work, we derive
and analyze stroke-averaged equations of motion that capture the effective
hydrodynamic far-field interaction between two oscillating, asymmetric
dumbbells in three space dimensions. Time-averaged equations of motion, as
those presented in this paper, not only yield a considerable speed-up in
numerical simulations, they may also serve as a starting point when deriving
continuum equations for the macroscopic dynamics of multi-swimmer suspensions.
The specific model discussed here appears to be particularly useful in this
context, since it allows one to investigate how the collective macroscopic
behavior is affected by changes in the microscopic symmetry of individual
swimmers.Comment: 10 pages, to appear in EPJ Special Topic
Spin Dependent Fragmentation Functions for Heavy Flavor Baryons and Single Heavy Hyperon Polarization
Spin dependent fragmentation functions for heavy flavor quarks to fragment
into heavy baryons are calculated in a quark-diquark model. The production of
intermediate spin 1/2 and 3/2 excited states is explicity included.
, and production rate and polarization at LEP energies are
calculated and, where possible, compared with experiment. A different approach,
also relying on a heavy quark-diquark model, is proposed for the small momentum
transfer inclusive production of polarized heavy flavor hyperons. The predicted
polarization is roughly in agreement with experiment.Comment: LaTeX2e 11 pages with 4 PostScript figures. To be published in
Proceedings of the International Workshop ``Symmetries and spin'',
Praha-SPIN-200
Variable response of nirK and nirS containing denitrifier communities to long term pH manipulation and cultivation
Denitrification is a key process responsible for the majority of soil nitrous oxide (N2O) emissions but the influences of pH and cultivation on the soil denitrifier community remain poorly understood. We hypothesised that the abundance and community structure of the total bacterial community and bacterial denitrifiers would be pH sensitive and that nirK and nirS containing denitrifiers would differ in their responses to change in pH and cultivation. We investigated the effect of long-term pH adjusted soils (ranging from pH 4.2 to pH 6.6) under different lengths of grass cultivation (one, two and three years of ley grass) on the general bacterial and denitrifier functional communities using 16S rRNA, nirK and nirS genes as markers. Denitrifier abundance increased with pH, and at pH below 4.7 there was a greater loss in nirS abundance per unit drop in pH than soils above this threshold pH. All community structures responded to changes in soil pH whilst cultivation only influenced the community structure of nirK. These differences in denitrifier responses highlight the importance of considering both nirK and nirS gene markers for estimating denitrifier activity. Identifying such thresholds in response of the microbial community to changes in pH is essential to understanding impacts of management or environmental change
Bacterial species from retailed poultry eggs in Tshwane, South Africa : implication for consumers
Food safety is an important public health issue and governments across the world are intensifying their
efforts to improve the quantity, quality and the safety of national food supplies. Bacteria, especially
Salmonella species, present in or on chicken meat and hens’ eggs in particular are the most common
causes of food poisoning and the major sources of human salmonellosis. Literature reveals little
information on the risk factors for salmonellae infection in Africa. The aim of this study was to determine
which, if any, bacteria, especially Salmonella species, are present in and on hens’ eggs. Representative
bacterial colonies were confirmed with Gram staining and then identified using the MALDI-TOF Biotyper
assay. The genera identified were Escherichia coli (34%), Enterococcus faecalis (14%), Proteus mirabilis
(9%), Klebshiella pneumoniae (7%), Salmonella Typhimurium (6%), Enterobacter cloacae (1%),
Stenotrophomonas maltophilia (0.6%), Salmonella Dublin (0.6%) and Salmonella Braenderup (0.2%).
Raw hens’ eggs and products containing raw hens’ eggs may contain pathogenic bacteria, thereby
exposing a large number of consumers to the risk of contracting food poisoning when undercooked or
uncooked hens’ eggs are consumed.
SIGNIFICANCE :
• Enterobacteriaceae counts are used as an indicator to evaluate the hygienic quality of food.
• The presence of Salmonella species and other Enterobacteriaceae in raw hens’ eggs poses a health risk
to consumers.
• Any product in which raw eggs are used must be provided with a conspicuous label stating that it may
contain pathogenic bacteria.Funding of the project was through the research funds of
F.S.B. and E.M.B.http://www.sajs.co.zaam2018Food ScienceParaclinical Science
Cosmology of the Lifshitz universe
We study the ultraviolet complete non-relativistic theory recently proposed
by Horava. After introducing a Lifshitz scalar for a general background, we
analyze the cosmology of the model in Lorentzian and Euclidean signature.
Vacuum solutions are found and it is argued the existence of non-singular
bouncing profiles. We find a general qualitative agreement with both the
picture of Causal Dynamical Triangulations and Quantum Einstein Gravity.
However, inflation driven by a Lifshitz scalar field on a classical background
might not produce a scale-invariant spectrum when the principle of detailed
balance is assumed.Comment: 23 pages. v2: one reference and one equation added, main conclusions
unchanged; v3: matches published version, discussion improved, typos
correcte
Anomalous diffusion, Localization, Aging and Sub-aging effects in trap models at very low temperature
We study in details the dynamics of the one dimensional symmetric trap model,
via a real-space renormalization procedure which becomes exact in the limit of
zero temperature. In this limit, the diffusion front in each sample consists in
two delta peaks, which are completely out of equilibrium with each other. The
statistics of the positions and weights of these delta peaks over the samples
allows to obtain explicit results for all observables in the limit .
We first compute disorder averages of one-time observables, such as the
diffusion front, the thermal width, the localization parameters, the
two-particle correlation function, and the generating function of thermal
cumulants of the position. We then study aging and sub-aging effects : our
approach reproduces very simply the two different aging exponents and yields
explicit forms for scaling functions of the various two-time correlations. We
also extend the RSRG method to include systematic corrections to the previous
zero temperature procedure via a series expansion in . We then consider the
generalized trap model with parameter and obtain that the
large scale effective model at low temperature does not depend on in
any dimension, so that the only observables sensitive to are those
that measure the `local persistence', such as the probability to remain exactly
in the same trap during a time interval. Finally, we extend our approach at a
scaling level for the trap model in and obtain the two relevant time
scales for aging properties.Comment: 33 pages, 3 eps figure
- …