9,302 research outputs found
Estimating the burden of malaria in Senegal : Bayesian zero-inflated binomial geostatistical modeling of the MIS 2008 data
The Research Center for Human Development in Dakar (CRDH) with the technical assistance of ICF Macro and the National Malaria Control Programme (NMCP) conducted in 2008/2009 the Senegal Malaria Indicator Survey (SMIS), the first nationally representative household survey collecting parasitological data and malaria-related indicators. In this paper, we present spatially explicit parasitaemia risk estimates and number of infected children below 5 years. Geostatistical Zero-Inflated Binomial models (ZIB) were developed to take into account the large number of zero-prevalence survey locations (70%) in the data. Bayesian variable selection methods were incorporated within a geostatistical framework in order to choose the best set of environmental and climatic covariates associated with the parasitaemia risk. Model validation confirmed that the ZIB model had a better predictive ability than the standard Binomial analogue. Markov chain Monte Carlo (MCMC) methods were used for inference. Several insecticide treated nets (ITN) coverage indicators were calculated to assess the effectiveness of interventions. After adjusting for climatic and socio-economic factors, the presence of at least one ITN per every two household members and living in urban areas reduced the odds of parasitaemia by 86% and 81% respectively. Posterior estimates of the ORs related to the wealth index show a decreasing trend with the quintiles. Infection odds appear to be increasing with age. The population-adjusted prevalence ranges from 0.12% in Thille-Boubacar to 13.1% in Dabo. Tambacounda has the highest population-adjusted predicted prevalence (8.08%) whereas the region with the highest estimated number of infected children under the age of 5 years is Kolda (13940). The contemporary map and estimates of malaria burden identify the priority areas for future control interventions and provide baseline information for monitoring and evaluation. Zero-Inflated formulations are more appropriate in modeling sparse geostatistical survey data, expected to arise more frequently as malaria research is focused on eliminatio
Partition Functions, the Bekenstein Bound and Temperature Inversion in Anti-de Sitter Space and its Conformal Boundary
We reformulate the Bekenstein bound as the requirement of positivity of the
Helmholtz free energy at the minimum value of the function L=E- S/(2\pi R),
where R is some measure of the size of the system. The minimum of L occurs at
the temperature T=1/(2\pi R). In the case of n-dimensional anti-de Sitter
spacetime, the rather poorly defined size R acquires a precise definition in
terms of the AdS radius l, with R=l/(n-2). We previously found that the
Bekenstein bound holds for all known black holes in AdS. However, in this paper
we show that the Bekenstein bound is not generally valid for free quantum
fields in AdS, even if one includes the Casimir energy. Some other aspects of
thermodynamics in anti-de Sitter spacetime are briefly touched upon.Comment: Latex, 32 page
Imaging features of rare mesenychmal liver tumours: beyond haemangiomas.
Tumours arising from mesenchymal tissue components such as vascular, fibrous and adipose tissue can manifest in the liver. Although histopathology is often necessary for definitive diagnosis, many of these lesions exhibit characteristic imaging features. The radiologist plays an important role in suggesting the diagnosis, which can direct appropriate immunohistochemical staining at histology. The aim of this review is to present clinical and imaging findings of a spectrum of mesenchymal liver tumours such as haemangioma, epithelioid haemangioendothelioma, lipoma, PEComa, angiosarcoma, inflammatory myofibroblastic tumour, solitary fibrous tumour, leiomyoma, leiomyosarcoma, Kaposi sarcoma, mesenchymal hamartoma, undifferentiated embryonal sarcoma, rhabdomyosarcoma and hepatic metastases. Knowledge of the characteristic features of these tumours will aid in guiding the radiologic diagnosis and appropriate patient management
Fitness, motor competence and body composition are weakly associated with adolescent back pain
Study Design: Cross sectional
Objectives: To assess the associations between adolescent back pain and fitness, motor competence and body composition.
Background: Although deficits in physical fitness and motor control have been shown to relate to adult back pain, the evidence in adolescents is less clear.
Methods and measures: In this cross-sectional study, 1608 Raine cohort adolescents (mean age, 14 years) answered questions on lifetime, month and chronic prevalence of back pain, and participated in a range of physical tests assessing aerobic capacity, muscle performance, flexibility, motor competence, and body composition. A history of diagnosed back pain in the adolescent was obtained from the primary caregiver.
Results: After multivariate logistic regression analysis, increased likelihood of back pain in boys was associated with greater aerobic capacity, greater waist girth and both reduced and greater flexibility. Back pain in girls was associated with greater abdominal endurance, reduced kinaesthetic integration, and both reduced and greater back endurance. Lower likelihood of back pain was associated with greater bimanual dexterity in boys and greater lower extremity power in girls.
Conclusion: Physical characteristics are commonly cited as important risk factors in back pain development. Although some factors were associated with adolescent back pain, and these differed between boys and girls, they made only a small contribution to logistic regression models for back pain. The results suggest future work should explore the interaction of multiple domains of risk factors (physical, lifestyle and psychosocial) and subgroups of adolescent back pain, for whom different risk factors may be important.
Mark Perry, Leon Straker, Peter B O\u27Sullivan, Anne Smith and Beth Hands, \u27Fitness, Motor Competence, and Body Composition Are Weakly Associated With Adolescent Back Pain\u27, Journal of Orthopedic and Sports Physical Therapy, Vol. 39 (6), 2009, p. 439-449.
ISSN: 0190-6011
DOI: 10.2519/jospt.2009.301
On Duality in the Born-Infeld Theory
The duality symmetric action for the Born-Infeld theory in terms of
two potentials, coupled with non-trivial backgroud fields in four dimensions is
established. This construction is carried out in detail by analysing the
hamiltonian structure of the Born-Infeld theory. The equivalence with the usual
Born-Infeld theory is shown.Comment: revtex, 4 page
Accounting for Dilution of SARS-CoV-2 in Wastewater Samples Using Physico-Chemical Markers
Most sewer networks collect domestic wastewater and a variable proportion of extraneous water, such as rainwater, through surface runoff and industrial discharges. Accounting for wastewater dilution is essential to properly quantify wastewater particle loads, whether these are molecular fragments of SARS-CoV-2, or other substances of interest such as illicit drugs or microplastics. This paper presents a novel method for obtaining real-time estimates of wastewater dilution and total daily volume through wastewater treatment works, namely when flow data is not available or unreliable. The approach considers the levels of several physico-chemical markers (ammonia, electrical conductivity, and orthophosphate) in the wastewater against their dry-weather levels. Using high-resolution data from the national Wastewater Surveillance Programme of Wales, we illustrate how the method is robust to spikes in markers and can recover peaks in wastewater flow measurements that may have been capped by hydraulic relief valves. We show the method proves effective in normalising SARS-CoV-2 viral loads in wastewater samples and discuss other applications for this method, looking at wastewater surveillance as a vital tool to monitor both human and environmental health
Rotating Hairy Black Holes
We construct stationary black holes in SU(2) Einstein-Yang-Mills theory,
which carry angular momentum and electric charge. Possessing non-trivial
non-abelian magnetic fields outside their regular event horizon, they represent
non-perturbative rotating hairy black holes.Comment: 13 pages, including 4 eps figures, LaTex forma
The local symmetries of M-theory and their formulation in generalised geometry
In the doubled field theory approach to string theory, the T-duality group is
promoted to a manifest symmetry at the expense of replacing ordinary Riemannian
geometry with generalised geometry on a doubled space. The local symmetries are
then given by a generalised Lie derivative and its associated algebra. This
paper constructs an analogous structure for M-theory. A crucial by-product of
this is the derivation of the physical section condition for M-theory
formulated in an extended space.Comment: 20 pages, v2: Author Name corrected, v3: typos correcte
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