307 research outputs found
Classical solutions for Yang-Mills-Chern-Simons field coupled to an external source
We find wide class of exact solutions of Yang-Mills-Chern-Simons theory
coupled to an external source, in terms of doubly periodic Jacobi elliptic
functions. The obtained solutions include localized solitons, trigonometric
solutions, pure cnoidal waves, and singular solutions in certain parameter
range. Furthermore, it is observed that these solutions exist over a nonzero
background.Comment: 5 page
Examining the impact of migration on health and modifiable health behaviours of individuals
Background: A fairly substantial body of evidence indicates that modifiable health behaviours may vary contingent upon a students’ residency, including whether students are studying away from their home country. This study aimed to investigate the impact of living away from home country on some lifestyles of international students at the University of Chester, UK. Method: Twenty-two international postgraduate students (23-41 years) at the University of Chester completed validated questionnaires relating to self-reported dietary patterns, physical activity and sleep quality based on circumstances before and after arrival in the UK. Self-reported body mass index (BMI) and self-reported waist circumference were also recorded. Results: Arrival in the UK was associated with a decreased adherence to the Mediterranean diet (p= .857), manifested in decreased fish, fruits and vegetables consumption. Decreased participation in sports (p= .007), as well as decreased sleep duration (p= .179) was reported upon arrival in the UK. Poor sleep quality was found to be prevalent within this sample (54.5%). The study observed both positive and negative lifestyle changes overall, although the latter was predominant. Conclusion: This sample of international students made more unfavourable changes in their dietary intake, physical activity levels and sleep duration upon relocating to the UK. It is imperative that close attention is paid to how international students adjust to life within the UK in order to provide healthier climate for learning
An event study to provide validation of TING and CMIT geomagnetic middle-latitude electron densities at the F2 peak
[1] The coupled thermosphere-ionosphere magnetosphere (CMIT) model and the Thermosphere Ionosphere Nested Grid (TING) model have been run to simulate the 15 May 1997 interplanetary coronal mass ejection\u27s (ICME) effects on the Earth\u27s ionosphere and thermosphere. Comparisons were made between these model runs, the IRI-2007 model, and geomagnetic middle-latitude ionosonde data (NmF2) from the World Data Center to determine how well the models simulated the event and to understand the causes of model-data disagreement. The following conclusions were drawn from this study: (1) skill scores were more often negative than positive on average; (2) the best and the worst skill scores occurred on the recovery day; (3) the line plots comparing models to data look better than the skill scores might suggest; (4) skill scores are significantly affected by timing issues and large, short-duration variability; (5) skill scores give an indication of the relative ability of one model relative to another, rather than an absolute statement of model accuracy; (6) the models capture negative storm effects better than they capture positive storm effects; (7) the TING model captured many short duration features seen in the data at high middle latitude stations that result from changes in the size of the auroral oval; (8) CMIT overestimates the energy driving changes in NmF2, whereas TING provides approximately the correct energy input as a result of the saturation effects on potential that are included in TING; and (9) both TING and CMIT electron densities decreased too rapidly after sunset
Sinusoidal Excitations in Two Component Bose-Einstein Condensates
The non-linear coupled Gross-Pitaevskii equation governing the dynamics of
the two component Bose-Einstein condensate (TBEC) is shown to admit pure
sinusoidal, propagating wave solutions in quasi one dimensional geometry. These
solutions, which exist for a wide parameter range, are then investigated in the
presence of a harmonic oscillator trap with time dependent scattering length.
This illustrates the procedure for coherent control of these modes through
temporal modulation of the parameters, like scattering length and oscillator
frequency. We subsequently analyzed this system in an optical lattice, where
the occurrence of an irreversible phase transition from superfluid to insulator
phase is seen.Comment: 6 pages, 1 figur
Do risk factors for suicidal behavior differ by affective disorder polarity?
BACKGROUND: Suicide is a leading cause of death and has been strongly associated with affective disorders. The influence of affective disorder polarity on subsequent suicide attempts or completions and any differential effect of suicide risk factors by polarity were assessed in a prospective cohort. METHODS: Participants with major affective disorders in the National Institute of Mental Health Collaborative Depression Study were followed prospectively for up to twenty-five years. A total of 909 participants meeting prospective diagnostic criteria for major depressive and bipolar disorders were followed through 4,204 mood cycles. Suicidal behavior was defined as suicide attempts or completions. Mixed-effects, grouped-time survival analysis assessed risk of suicidal behavior and differential effects of risk factors for suicidal behavior by polarity. In addition to polarity, the main effects of age, gender, hopelessness, married status, prior suicide attempts, and active substance abuse were modeled with mood cycle as the unit of analysis. RESULTS: After controlling for age of onset, there were no differences in prior suicide attempts by polarity though bipolar participants had more prior severe attempts. During follow-up, forty cycles ended in suicide and 384 cycles contained at least one suicide attempt. Age, hopelessness, and active substance abuse but not polarity predicted suicidal behavior. The effects of risk factors did not differ by polarity. CONCLUSIONS: Bipolarity does not independently influence risk of suicidal behavior or the influence of well-established suicide risk factors within affective disorders. Suicide risk assessment strategies may continue to appraise these common risk factors without regard to mood polarity
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On-line case discussion assessment in Ultrasound: The effect on student centred and inter-professional learning
In 2009 an asynchronous on-line case discussion assessment was introduced, to replace an existing traditional case-study assessment, within the Medical Ultrasound Programmes at City University London, to help extend collaborative, interprofessional student-led learning skills. Two clinical modules were used to develop the on-line learning method with associated assessments. Students selected and led a clinical case from their department, uploaded anonymised images and case details with questions, to encourage interaction from other colleagues. Thirty students participated in the on-line case discussions. The assessment was evaluated via informal feedback, end of module feedback and an on-line questionnaire. Some students completed two modules, using the on-line discussion, others were involved in only one module, of which 21 out of 26 students completed end of module feedback for the 1st module and 18 out of 20 students completed feedback from the 2nd module. Twelve students out of 30 completed the on-line questionnaire. Feedback suggested that the on-line case discussions were a good learning tool, providing a wide range of cases for students to participate in or read and learn from each other. All students found the cases interesting, engaging and useful, but time consuming. Despite the small numbers involved, useful feedback was provided to assist further development of the assessment, particularly in relation to the number of cases being assessed and length of availability. On-line case discussions are an innovative, engaging method to encourage self directed, collaborative learning which could be utilised in the health care setting to share interesting cases, promote inter-professional and self-directed learning
Dimensions of biodiversity in Chesapeake Bay demersal fishes: patterns and drivers through space and time
Biodiversity has typically been described in terms of species richness and composition, but theory and growing empirical evidence indicate that the diversity of functional traits, the breadth of evolutionary relationships, and the equitability with which individuals or biomass are distributed among species better characterize patterns and processes within ecosystems. Yet, the advantages of including such data come at the expense of measuring traits, sequencing genes, and counting or weighing individuals, and it remains unclear whether this greater resolution yields substantial benefits in describing diversity. We summarized a decade of high-resolution trawl data from a bimonthly trawl survey to investigate spatial and seasonal patterns of demersal fish diversity in the Chesapeake Bay, USA, with the goal of identifying areas and times of mismatch between different dimensions of diversity, and their response to environmental forcing. We found moderate to strong positive relationships among all metrics of diversity, and that functional and phylogenetic differences were well-reflected in an index derived from taxonomic (Linnaean) hierarchy. Compared with species richness and species diversity, functional, phylogenetic, and taxonomic indices peaked later in the year, which was a consequence of the distribution of biomass among functionally and evolutionarily divergent species. Generalized additive models revealed that spatial, temporal, and environmental variables explained roughly similar proportions of deviance across all aspects of diversity, suggesting that these three factors do not differentially affect the functional and phylogenetic aspects of community structure. We conclude that an index of diversity derived from taxonomic hierarchy served well as a practical surrogate for functional and phylogenetic diversity of the demersal fish community in this system. We also emphasize the importance of evenness in understanding diversity patterns, especially since most ecological communities in nature are dominated by one or few species
Patient-reported outcomes of pain and physical functioning in neurofibromatosis clinical trials.
ObjectiveTumors and other disease complications of neurofibromatosis (NF) can cause pain and negatively affect physical functioning. To document the clinical benefit of treatment in NF trials targeting these manifestations, patient-reported outcomes (PROs) assessing pain and physical functioning should be included as study endpoints. Currently, there is no consensus on the selection and use of such measures in the NF population. This article presents the recommendations of the PRO group of the Response Evaluation in Neurofibromatosis and Schwannomatosis (REiNS) International Collaboration for assessing the domains of pain and physical functioning for NF clinical trials.MethodsThe REiNS PRO group reviewed and rated existing PRO measures assessing pain intensity, pain interference, and physical functioning using their systematic method. Final recommendations are based primarily on 4 main criteria: patient characteristics, item content, psychometric properties, and feasibility for clinical trials.ResultsThe REiNS PRO group chose the Numeric Rating Scale-11 (≥8 years) to assess pain intensity, the Pain Interference Index (6-24 years) and the Patient-Reported Outcome Measurement Information System (PROMIS) Pain Interference Scale (≥18 years) to evaluate pain interference, and the PROMIS Physical Functioning Scale to measure upper extremity function and mobility (≥5 years) for NF clinical trials.ConclusionsThe REiNS Collaboration currently recommends these PRO measures to assess the domains of pain and physical functioning for NF clinical trials; however, further research is needed to evaluate their use in individuals with NF. A final consensus recommendation for the pain interference measure will be disseminated in a future publication based on findings from additional published research
Trends and determinants of underweight and overweight/obesity among urban Ethiopian women from 2000 to 2016
Background: Nutritional, epidemiological and demographic transitions have been associated with the emergence of the double burden of malnutrition globally. In Ethiopia, there has been no nationally representative investigation of trends and determinants of both underweight and overweight/obesity among urban women. This study examined the trends and determinants of underweight and overweight/obesity in urban Ethiopian women from 2000 to 2016. Methods: Trends in the prevalence of underweight and overweight/obesity were investigated based on a series of the Ethiopia Demographic and Health Survey (EDHS) data for the years 2000 (n = 2559), 2005 (n = 1112), 2011 (n = 3569), and 2016 (n = 3106). Multivariable multinomial logistic regression was used to investigate the association between socioeconomic, demographic, behavioural, and community-level factors with underweight and overweight/obesity. Results: The prevalence of underweight in urban Ethiopian women reduced significantly from 23.2% (95% confidence interval [CI]: 20.3, 26.3%) in 2000 to 14.8% (95% CI: 13.1, 16.7%) in 2016, while overweight/obesity increased significantly from 10.9% (95% CI: 9.1, 13.0%) in 2000 to 21.4% (95% CI: 18.2, 25.1%) in 2016. Urban women from rich households and those who had never married were less likely to be underweight. Urban women who were from wealthy households and those who attained at least secondary education were more likely to be overweight/obese. Women who were informally employed and listened to the radio were less likely to be overweight/obese compared to those who were unemployed and did not listen to the radio, respectively. Conclusion: The prevalence of overweight/obesity increased from 2000 to 2016, with a concurrent reduction in the prevalence of underweight. Interventions aiming to reduce overweight and obesity should target urban women with higher education, those who resided in wealthier households and those who watched the television
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