14,468 research outputs found

    Topological Interactions in Warped Extra Dimensions

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    Topological interactions will be generated in theories with compact extra dimensions where fermionic chiral zero modes have different localizations. This is the case in many warped extra dimension models where the right-handed top quark is typically localized away from the left-handed one. Using deconstruction techniques, we study the topological interactions in these models. These interactions appear as trilinear and quadrilinear gauge boson couplings in low energy effective theories with three or more sites, as well as in the continuum limit. We derive the form of these interactions for various cases, including examples of Abelian, non-Abelian and product gauge groups of phenomenological interest. The topological interactions provide a window into the more fundamental aspects of these theories and could result in unique signatures at the Large Hadron Collider, some of which we explore.Comment: 40 pages, 10 figures, 2 tables; modifications in the KK parity discussion, final version at JHE

    Pseudo-Automorphisms of positive entropy on the blowups of products of projective spaces

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    We use a concise method to construct pseudo-automorphisms f_n of the first dynamical degree d_1(f_n) > 1 on the blowups of the projective n-space for all n > 1 and more generally on the blowups of products of projective spaces. These f_n, for n = 3 have positive entropy, and for n > 3 seem to be the first examples of pseudo-automorphisms with d_1(f_n) > 1 (and of non-product type) on rational varieties of higher dimensions.Comment: Mathematische Annalen (to appear

    Distribution and habitats of Bulinus depressus and possible role as intermediate host of economically important helminth parasites in South Africa

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    This article documents the large-scale spatial distribution and ecological descriptors of associated habitats of Bulinus depressus by analysis of samples taken from 552 collection sites on record in the database of the National Freshwater Snail Collection (NFSC) at the Potchefstroom Campus of the North-West University. This snail species is experimentally susceptible to Schistosoma margrebowiei, a helminth parasite of game animals and cattle and can possibly also exploit humans as definitive hosts. The 125 different loci (1/16 degree squares) on record reflect a geographical distribution that is largely limited to the central and western part of the Limpopo Province and westwards down the basins of the Vaal and Orange Rivers. Details of each habitat as described by collectors during surveys, as well as altitude and mean annual air temperature and rainfall for each locality, were processed and chi-square and effect size values calculated. A decision tree constructed from all the available data indicated that temperature and altitude, followed by the type of water-body, seemed to be the more important factors that significantly influenced the distribution of this species in South Africa. The possible role of this species as intermediate host of economically important helminth species is briefly looked at and the urgent need to update the geographical distribution of host snails is emphasised. It is recommended that efforts be made to determine the exact role of B. depressus in the epidemiology of economically important helminth parasites. Keywords: Bulinus depressus, geographical distribution, habitat preferences, Schistosoma margrebowiei Water SA Vol. 31(4) 2005: 491-49

    Psychometric evaluation of the German version of a social support scale of FAFHES (family functioning, family health and social support)

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    This is the peer reviewed version which has been published in final form at https://doi.org/10.1111/scs.12700. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Use of Self-Archived Versions.BACKGROUND: Family members often need to be supported in informal care of the elderly and desire to be involved into care planning and decision-making. Valid and reliable instruments are needed to measure how family members perceive the care and support they receive from nurses for older family members living at home. AIM: The purpose of this study was to translate the 20-item social support scale of the Family Functioning, Family Health and Social Support (FAFHES) questionnaire from English to German and test the validity and reliability of the scale among Swiss-German-speaking family caregivers of home-dwelling elderly people who receive home healthcare services. METHODS: A cross-sectional study was conducted to test the empirical and psychometric properties of the translated and culturally adapted version of the social support questionnaire. A factor analysis with the principal component analysis PCA was used to test construct validity. The internal consistency of items was measured with the Cronbach`s alpha coefficient. RESULTS: After a rigorous translation process the original 20-item questionnaire was adapted into a 19-item version and tested with family caregivers (n = 207) of home-dwelling elderly. Psychometric testing of the German version of the social support questionnaire revealed that the three factors - affirmation, affect and concrete aid - were congruent with the original questionnaire. The accounted variance was 79.5% and the internal consistency determined by the Cronbach's alpha was 0.973. CONCLUSION: The German version of the social support scale of the FAFHES questionnaire is a valid and reliable instrument to assess family perceived support on three dimensions - affirmation, affect and concrete aid - received from nursing professionals. The questionnaire should be tested further in other German-speaking population

    Which prosthetic foot to prescribe?

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    Introduction: Clinicians typically use findings from cohort studies to objectively inform judgements regarding the potential (dis)advantages of prescribing a new prosthetic device. However, before finalising prescription a clinician will typically ask a patient to 'try out' a change of prosthetic device while the patient is at the clinic. Observed differences in gait when using the new device should be the result of the device’s mechanical function, but could also conceivably be due to patient related factors which can change from day-to-day and can thus make device comparisons unreliable. To determine whether a device’s mechanical function consistently has a more meaningful impact on gait than patient-related factors, the present study undertook quantitative gait analyses of a trans-tibial amputee walking using two different foot-ankle devices on two occasions over a year apart. If the observed differences present between devices, established using quantitative gait analysis, were in the same direction and of similar magnitude on each of the two occasions, this would indicate that device-related factors were more important than patient-related factors. Methods: One adult male with a unilateral trans-tibial amputation completed repeated walking trials using two different prosthetic foot devices on two separate occasions, 14 months apart. Walking speed and sagittal plane joint kinematics and kinetics for both limbs were assessed on each occasion. Clinically meaningful differences in these biomechanical outcome variables were defined as those with an effect size difference (d) between prosthetic conditions of at least 0.4 (i.e. 'medium' effect size). Results: Eight variables namely, walking speed, prosthetic 'ankle' peak plantar- and dorsi-flexion and peak positive power, and residual knee loading response flexion, peak stance-phase extension and flexion moments and peak negative power, displayed clinically meaningful differences (d > 0.4) between foot devices during the first session. All eight of these showed similar effect size differences during the second session despite the participant being heavier and older. Conclusions: Findings suggest that a prosthetic device's mechanical function consistently has a more meaningful impact on gait than patient-related factors. These findings support the current clinical practice of making decisions regarding prosthetic prescription for an individual, based on a single session evaluation of their gait using two different devices. However, to confirm this conclusion, a case series using the same approach as the present study could be undertaken

    Modelling disease activity in juvenile dermatomyositis: A Bayesian approach

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    Juvenile dermatomyositis is the most common form of the juvenile idiopathic inflammatory myopathies characterised by muscle and skin inflammation, leading to symmetric proximal muscle weakness and cutaneous symptoms. It has a fluctuating course and varying prognosis. In a Bayesian framework, we develop a joint model for four longitudinal outcomes, which accounts for within individual variability as well as inter-individual variability. Correlations among the outcome variables are introduced through a subject-specific random effect. Moreover, we exploit an approach similar to a hurdle model to account for excess of a specific outcome in the response. Clinical markers and symptoms are used as covariates in a regression set-up. Data from an ongoing observational cohort study are available, providing information on 340 subjects, who contributed 2725 clinical visits. The model shows good performance and yields efficient estimations of model parameters, as well as accurate predictions of the disease activity parameters, corresponding well to observed clinical patterns over time. The posterior distribution of the by-subject random intercepts shows a substantial correlation between two of the outcome variables. A subset of clinical markers and symptoms are identified as associated with disease activity. These findings have the potential to influence clinical practice as they can be used to stratify patients according to their prognosis and guide treatment decisions, as well as contribute to on-going research about the most relevant outcome markers for patients affected by juvenile dermatomyositis

    Demonstration project on epilepsy in Brazil - Outcome assessment

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    Purpose: To assess the outcome of patients with epilepsy treated at primary care health units under the framework of the demonstration project on epilepsy in Brazil, part of the WHO/ILAE/IBE Global Campaign Against Epilepsy. Method. We assessed the outcome of patients treated at four primary health units. The staff of the health units underwent information training in epilepsy. The outcome assessment was based on: 1) reduction of seizure frequency, 2) subjective perception from the patient's and the physician's point of view, 3) reduction of absenteeism, 4) social integration (school and work), and 5) sense of independence. Results: A total of 181 patients (93 women - 51%) with a mean age of 38 (range from 2 to 86) years were studied. The mean follow-up was 26 months (range from 1 to 38 months, 11 patients had follow-up of less than 12 months). Seizure frequency was assessed based on a score system, ranging from 0 (no seizure in the previous 24 months) to 7 (> 10 seizure/day). The baseline median seizure-frequency score was 3 (one to three seizures per month). At the end of the study the median seizure-frequency score was 1 (one to three seizures per year). The patients' and relatives' opinions were that in the majority (59%) the health status had improved a lot, some (19%) had improved a little, 20% experienced no change and in 2% the health status was worse. With regard to absenteeism, social integration and sense of independence, there were some modest improvements only. Discussion: The development of a model of epilepsy treatment at primary health level based on the existing health system, with strategic measures centred on the health care providers and the community, has proved to be effective providing important reductions in seizure frequency, as well as in general well being. This model can be applied nationwide, as the key elements already exist provided that strategic measures are put forward in accordance with local health providers and managers
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