Mobile radio propagation prediction using ray tracing methods

The basic problem is to solve the two-dimensional scalar Helmholtz equation for a point source (the antenna) situated in the vicinity of an array of scatterers (such as the houses and any other relevant objects in 1 square km of urban environment). The wavelength is a few centimeters and the houses a few metres across, so there are three disparate length scales in the problem. The question posed by BT concerned ray counting on the assumptions that: (i) rays were subject to a reflection coefficient of about 0.5 when bouncing off a house wall and (ii) that diffraction at corners reduced their energy by 90%. The quantity of particular interest was the number of rays that need to be accounted for at any particular point in order for those neglected to only contribute 10% of the field at that point; a secondary question concerned the use of rays to predict regions where the field was less than 1% of that in the region directly illuminated by the antenna. The progress made in answering these two questions is described in the next two sections and possibly useful representations of the solution of the Helmholtz equations in terms other than rays are given in the final section

Submerged in the mainstream? A case study of an immigrant learner in a New Zealand primary classroom

Immigrant children from diverse language backgrounds face not only linguistic challenges when enrolled in mainstream English-medium classrooms, but also difficulties adjusting to an unfamiliar learning community. The culture of primary school classrooms in New Zealand typically reflects conventions across three dimensions: interactional, instructional task performance and cognitive-academic development. All three dimensions are underpinned by the culturally specific discourse conventions involved in language socialisation. New learners may be helped by classmates or their teacher to understand and successfully use these conventions, but left on their own they may sink rather than swim. This is a case study of one Taiwanese 11-year old boy, 'John', who entered a New Zealand primary classroom midway through the school year. John's basic conversational ability was sound, but he did not possess the interactive classroom skills needed to operate in the new culture of learning. Selected from a wider study of the classroom, transcript data from audio-recorded excerpts of John's interactions over several months with his teacher and classmates are interpreted from perspectives derived from sociocultural and language socialisation theories. The article concludes with a brief consideration of the extent to which John constructed, or was constrained from constructing meaningful learning experiences, and suggestions for further research and reflection

Before and after study of bar workers' perceptions of the impact of smoke-free workplace legislation in the Republic of Ireland

<p>Abstract</p> <p>Background</p> <p><it>Objectives</it>: To compare support for, and perceptions of, the impacts of smoke-free workplace legislation among bar workers in the Republic of Ireland (ROI) pre- and post-implementation, and to identify predictors of support for the legislation.</p> <p>Methods</p> <p><it>Setting</it>: Public houses (pubs) in three areas of the ROI.</p> <p><it>Design</it>: Comparisons pre- and post-implementation of smoke-free workplace legislation.</p> <p><it>Participants</it>: From a largely non-random selection, 288 bar workers volunteered for the baseline survey; 220 were followed up one year later (76.4%).</p> <p><it>Outcome measures: </it>Level of support for the legislation, attitude statements concerning potential impacts of the law and modelled predictors of support for the legislation.</p> <p>Results</p> <p>Pre-implementation 59.5% of participants supported the legislation, increasing to 76.8% post-implementation. Support increased among smokers by 27.3 percentage points from 39.4% to 66.7% (p < 0.001) and among non-smokers by 12.4% percentage points from 68.8% to 81.2% (p = 0.003).</p> <p>Pre-legislation three-quarters of participants agreed that the legislation would make bars more comfortable and was needed to protect workers' health. Post-legislation these proportions increased to over 90% (p < 0.001). However, negative perceptions also increased, particularly for perceptions that the legislation has a negative impact on business (from 50.9% to 62.7%, p = 0.008) and that fewer people would visit pubs (41.8% to 62.7%, p < 0.001). After adjusting for relevant covariates, including responses to the attitude statements, support for the ban increased two to three-fold post-implementation. Regardless of their views on the economic impact, most participants agreed, both pre- and post-implementation, that the legislation was needed to protect bar workers' health.</p> <p>Conclusion</p> <p>Smoke-free legislation had the support of three-quarters of a large sample of bar workers in the ROI. However, this group holds complex sets of both positive and negative perspectives on the legislation. Of particular importance is that negative economic perceptions did not diminish the widely held perception that the ban is needed to protect workers' health.</p

Global Prevalence and Mental Health Outcomes of Intimate Partner Violence Among Women: A Systematic Review and Meta-Analysis

The aim of this systematic review was to assess the magnitude of the association between types of intimate partner violence (IPV) and mental health outcomes and shed light on the large variation in IPV prevalence rates between low- to middle-income countries and high-income countries. The study is a systematic review and meta-analysis. The following databases were searched for this study: Cochrane, MEDLINE, EMBASE, PsycINFO, Cumulative Index to Nursing and Allied Health Literature, and the Applied Social Sciences Index and Abstracts. The inclusion criteria for this study are as follows: quantitative studies published from 2012 to 2020 on IPV exposure in women aged 16+, using validated measures. Random effects meta-analyses and subgroup analysis exploring heterogeneity across population groups in different economic contexts are used in this study. In all, 201 studies were included with 250,599 women, primarily from high-income countries. Higher prevalence rates were reported for women’s lifetime IPV than past year IPV. Lifetime psychological violence was the most prevalent form of IPV. Women in the community reported the highest prevalence for physical, psychological, and sexual violence in the past year compared to clinical groups. Perinatal women were most likely to have experienced lifetime physical IPV. Prevalence rates differed significantly (p = .037 to <.001) for “any IPV” and all subtypes by income country level. Meta-analysis suggested increased odds for all mental health outcomes associated with IPV including depression (odds ratio [OR] = 2.04–3.14), posttraumatic stress disorder (PTSD) (OR = 2.15–2.66), and suicidality (OR = 2.17–5.52). Clinical and community populations were exposed to high prevalence of IPV and increased likelihood of depression, PTSD, and suicidality. Future research should seek to understand women’s perspectives on service/support responses to IPV to address their mental health needs. Work with IPV survivors should be carried out to develop bespoke services to reduce IPV in groups most at risk such as pregnant and/or help-seeking women

Global Prevalence and Mental Health Outcomes of Intimate Partner Violence Among Women: A Systematic Review and Meta-Analysis

The aim of this systematic review was to assess the magnitude of the association between types of intimate partner violence (IPV) and mental health outcomes and shed light on the large variation in IPV prevalence rates between low- to middle-income countries and high-income countries. The study is a systematic review and meta-analysis. The following databases were searched for this study: Cochrane, MEDLINE, EMBASE, PsycINFO, Cumulative Index to Nursing and Allied Health Literature, and the Applied Social Sciences Index and Abstracts. The inclusion criteria for this study are as follows: quantitative studies published from 2012 to 2020 on IPV exposure in women aged 16+, using validated measures. Random effects meta-analyses and subgroup analysis exploring heterogeneity across population groups in different economic contexts are used in this study. In all, 201 studies were included with 250,599 women, primarily from high-income countries. Higher prevalence rates were reported for women’s lifetime IPV than past year IPV. Lifetime psychological violence was the most prevalent form of IPV. Women in the community reported the highest prevalence for physical, psychological, and sexual violence in the past year compared to clinical groups. Perinatal women were most likely to have experienced lifetime physical IPV. Prevalence rates differed significantly (p = .037 to <.001) for “any IPV” and all subtypes by income country level. Meta-analysis suggested increased odds for all mental health outcomes associated with IPV including depression (odds ratio [OR] = 2.04–3.14), posttraumatic stress disorder (PTSD) (OR = 2.15–2.66), and suicidality (OR = 2.17–5.52). Clinical and community populations were exposed to high prevalence of IPV and increased likelihood of depression, PTSD, and suicidality. Future research should seek to understand women’s perspectives on service/support responses to IPV to address their mental health needs. Work with IPV survivors should be carried out to develop bespoke services to reduce IPV in groups most at risk such as pregnant and/or help-seeking women

Reductions in cardiovascular, cerebrovascular, and respiratory mortality following the national Irish smoking ban: Interrupted time-series analysis

Copyright @ 2013 Stallings-Smith et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.This article has been made available through the Brunel Open Access Publishing Fund.Background: Previous studies have shown decreases in cardiovascular mortality following the implementation of comprehensive smoking bans. It is not known whether cerebrovascular or respiratory mortality decreases post-ban. On March 29, 2004, the Republic of Ireland became the first country in the world to implement a national workplace smoking ban. The aim of this study was to assess the effect of this policy on all-cause and cause-specific, non-trauma mortality. Methods: A time-series epidemiologic assessment was conducted, utilizing Poisson regression to examine weekly age and gender-standardized rates for 215,878 non-trauma deaths in the Irish population, ages ≥35 years. The study period was from January 1, 2000, to December 31, 2007, with a post-ban follow-up of 3.75 years. All models were adjusted for time trend, season, influenza, and smoking prevalence. Results: Following ban implementation, an immediate 13% decrease in all-cause mortality (RR: 0.87; 95% CI: 0.76-0.99), a 26% reduction in ischemic heart disease (IHD) (RR: 0.74; 95% CI: 0.63-0.88), a 32% reduction in stroke (RR: 0.68; 95% CI: 0.54-0.85), and a 38% reduction in chronic obstructive pulmonary disease (COPD) (RR: 0.62; 95% CI: 0.46-0.83) mortality was observed. Post-ban reductions in IHD, stroke, and COPD mortalities were seen in ages ≥65 years, but not in ages 35-64 years. COPD mortality reductions were found only in females (RR: 0.47; 95% CI: 0.32-0.70). Post-ban annual trend reductions were not detected for any smoking-related causes of death. Unadjusted estimates indicate that 3,726 (95% CI: 2,305-4,629) smoking-related deaths were likely prevented post-ban. Mortality decreases were primarily due to reductions in passive smoking. Conclusions: The national Irish smoking ban was associated with immediate reductions in early mortality. Importantly, post-ban risk differences did not change with a longer follow-up period. This study corroborates previous evidence for cardiovascular causes, and is the first to demonstrate reductions in cerebrovascular and respiratory causes

Primary medical care in Irish prisons

BACKGROUND: An industrial dispute between prison doctors and the Irish Prison Service (IPS) took place in 2004. Part of the resolution of that dispute was that an independent review of prison medical and support services be carried out by a University Department of Primary Care. The review took place in 2008 and we report here on the principal findings of that review. METHODS: This study utilised a mixed methods approach. An independent expert medical evaluator (one of the authors, DT) inspected the medical facilities, equipment and relevant custodial areas in eleven of the fourteen prisons within the IPS. Semistructured interviews took place with personnel who had operational responsibility for delivery of prison medical care. Prison doctors completed a questionnaire to elicit issues such as allocation of clinician's time, nurse and administrative support and resources available. RESULTS: There was wide variation in the standard of medical facilities and infrastructure provided across the IPS. The range of medical equipment available was generally below that of the equivalent general practice scheme in the community. There is inequality within the system with regard to the ratio of doctor-contracted time relative to the size of the prison population. There is limited administrative support, with the majority of prisons not having a medical secretary. There are few psychiatric or counselling sessions available. CONCLUSIONS: People in prison have a wide range of medical care needs and there is evidence to suggest that these needs are being met inconsistently in Irish prisons

Chronic illness and multimorbidity among problem drug users: a comparative cross sectional pilot study in primary care

<p>Abstract</p> <p>Background</p> <p>Although multimorbidity has important implications for patient care in general practice, limited research has examined chronic illness and health service utilisation among problem drug users. This study aimed to determine chronic illness prevalence and health service utilisation among problem drug users attending primary care for methadone treatment, to compare these rates with matched 'controls' and to develop and pilot test a valid study instrument.</p> <p>Methods</p> <p>A cross-sectional study of patients attending three large urban general practices in Dublin, Ireland for methadone treatment was conducted, and this sample was compared with a control group matched by practice, age, gender and General Medical Services (GMS) status.</p> <p>Results</p> <p>Data were collected on 114 patients. Fifty-seven patients were on methadone treatment, of whom 52(91%) had at least one chronic illness (other then substance use) and 39(68%) were prescribed at least one regular medication. Frequent utilisation of primary care services and secondary care services in the previous six months was observed among patients on methadone treatment and controls, although the former had significantly higher chronic illness prevalence and primary care contact rates. The study instrument facilitated data collection that was feasible and with minimal inter-observer variation.</p> <p>Conclusion</p> <p>Multimorbidity is common among problem drug users attending general practice for methadone treatment. Primary care may therefore have an important role in primary and secondary prevention of chronic illnesses among this population. This study offers a feasible study instrument for further work on this issue. (238 words)</p

Dynamics of compartmental model recurrent neural networks

This article was published in the journal, Physical Review E [© American Physical Society]. It is also available at: http://link.aps.org/abstract/PRE/v50/p2308.We show how the dynamics of a recurrent network of compartmental model neurons can be formulated in terms of a set of coupled nonlinear Volterra integrodifferential equations in which the state of each neuron is represented by a single scalar variable. The associated convolution kernels are determined by the single neuron membrane potential response function, which can be calculated explicitly for arbitrary dendritic tree topologies. Our integral equation approach provides a compact and analytically tractable method for studying the effects of dendritic structure on network dynamics. We illustrate this by deriving conditions for the onset of oscillations in a compartmental model network that depend both on the interneuron connection weights and on the internal dendritic structure of the individual neurons. It is shown that it is possible for a symmetrically connected compartmental model network to oscillate