4,509 research outputs found

    The effect of urbanisation on health in a mining area of Sierra Leone

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    1. This section describes a study on the effect on health of urbanisation in Lunsar, Sierra Leone, using sampling techniques and health indicators. • 2. Data collected in preliminary studies are described. • 3. The Lunsar Health Centre Records, Birth and Death Registers, and Burial Record Book were examined and found to give data which were unreliable for use or modification in assessing the health of the town. • 4. A 10% sample Census of Lunsar was carried out, and the extracted data were discussed. • 5. A 40% Clinical Sample of the Census Sample was drawn and a total of 380 persons were examined clinically. The extracted data were analysed. • 6. Using morbidity and survival data as indices it was found that the 'urban' part of Lunsar's population, namely that section living on a wage packet, was better off in respect of those indices than the 'rural' section of the community. • 7. Data were also collected on environmental conditions such as housing, including overcrowding, water supplies and disposal of excreta. • 8. The mentally and physically handicapped persons in Lunsar were discussed

    Structural Assembly Demonstration Experiment (SADE)

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    The purpose of the Structural Assembly Demonstration Experiment (SADE) was to create a near-term Shuttle flight experiment focusing on the deployment and erection of structural truss elements. The activities of the MIT Space Systems Laboratory consist of three major areas: preparing and conducting neutral buoyancy simulation test series; producing a formal SADE Experiment plan; and studying the structural dynamics issues of the truss structure. Each of these areas is summarized

    Motor onset and diagnosis in Huntington disease using the diagnostic confidence level

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    Huntington disease (HD) is a neurodegenerative disorder characterized by motor dysfunction, cognitive deterioration, and psychiatric symptoms, with progressive motor impairments being a prominent feature. The primary objectives of this study are to delineate the disease course of motor function in HD, to provide estimates of the onset of motor impairments and motor diagnosis, and to examine the effects of genetic and demographic variables on the progression of motor impairments. Data from an international multisite, longitudinal observational study of 905 prodromal HD participants with cytosine-adenine-guanine (CAG) repeats of at least 36 and with at least two visits during the followup period from 2001 to 2012 was examined for changes in the diagnostic confidence level from the Unified Huntington's Disease Rating Scale. HD progression from unimpaired to impaired motor function, as well as the progression from motor impairment to diagnosis, was associated with the linear effect of age and CAG repeat length. Specifically, for every 1-year increase in age, the risk of transition in diagnostic confidence level increased by 11% (95% CI 7-15%) and for one repeat length increase in CAG, the risk of transition in diagnostic confidence level increased by 47% (95% CI 27-69%). Findings show that CAG repeat length and age increased the likelihood of the first onset of motor impairment as well as the age at diagnosis. Results suggest that more accurate estimates of HD onset age can be obtained by incorporating the current status of diagnostic confidence level into predictive models

    Supernova Remnants in the Magellanic Clouds III: An X-ray Atlas of LMC Supernova Remnants

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    We have used archival ROSAT data to present X-ray images of thirty-one supernova remnants (SNRs) in the Large Magellanic Cloud (LMC). We have classified these remnants according to their X-ray morphologies, into the categories of Shell-Type, Diffuse Face, Centrally Brightened, Point-Source Dominated, and Irregular. We suggest possible causes of the X-ray emission for each category, and for individual features of some of the SNRs.Comment: 27 pages, 6 figures (9 figure files). To appear in the Supplement Series of the Astrophysical Journal, August 1999 Vol. 123 #

    The Relation Between the Surface Brightness and the Diameter for Galactic Supernova Remnants

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    In this work, we have constructed a relation between the surface brightness (Σ\Sigma) and diameter (D) of Galactic C- and S-type supernova remnants (SNRs). In order to calibrate the Σ\Sigma-D dependence, we have carefully examined some intrinsic (e.g. explosion energy) and extrinsic (e.g. density of the ambient medium) properties of the remnants and, taking into account also the distance values given in the literature, we have adopted distances for some of the SNRs which have relatively more reliable distance values. These calibrator SNRs are all C- and S-type SNRs, i.e. F-type SNRs (and S-type SNR Cas A which has an exceptionally high surface brightness) are excluded. The Sigma-D relation has 2 slopes with a turning point at D=36.5 pc: Σ\Sigma(at 1 GHz)=8.46.3+19.5^{+19.5}_{-6.3}×1012\times10^{-12} D5.990.33+0.38^{{-5.99}^{+0.38}_{-0.33}} Wm2^{-2}Hz1^{-1}ster1^{-1} (for Σ\Sigma3.7×1021\le3.7\times10^{-21} Wm2^{-2}Hz1^{-1}ster1^{-1} and D\ge36.5 pc) and Σ\Sigma(at 1 GHz)=2.71.4+2.1^{+2.1}_{-1.4}×\times 1017^{-17} D2.470.16+0.20^{{-2.47}^{+0.20}_{-0.16}} Wm2^{-2}Hz1^{-1}ster1^{-1} (for Σ\Sigma>3.7×1021>3.7\times10^{-21} Wm2^{-2}Hz1^{-1}ster1^{-1} and D<<36.5 pc). We discussed the theoretical basis for the Σ\Sigma-D dependence and particularly the reasons for the change in slope of the relation were stated. Added to this, we have shown the dependence between the radio luminosity and the diameter which seems to have a slope close to zero up to about D=36.5 pc. We have also adopted distance and diameter values for all of the observed Galactic SNRs by examining all the available distance values presented in the literature together with the distances found from our Σ\Sigma-D relation.Comment: 45 pages, 2 figures, accepted for publication in Astronomical and Astrophysical Transaction

    An examination of dental crowding and its relationship to tooth size and arch dimension

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    This investigation was undertaken to examine the extent to which tooth size and jaw size each contribute to dental crowding. Two groups of dental casts were selected on the basis of dental crowding. One group, consisting of 50 pairs of dental casts (18 males and 32 females), exhibited gross dental crowding. A second group, consisting of 54 pairs of dental casts (24 males and 30 females), exhibited little or no crowding. Means and standard deviations of the following parameters were used to compare the two groups: individual and collective mesiodistal tooth diameters, dental arch perimeters, and buccal and lingual dental arch widths. Statistically, the crowded and noncrowded groups could not be distinguished from each other on the basis of mesiodistal tooth diameters. However, significant differences were observed between the dental arch dimensions of the two groups. The crowded group was found to have smaller dental arch dimensions than the noncrowded group. The results of this study suggest that consideration be given to those treatment techniques which increase dental arch length rather than reduce tooth mass.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/25232/1/0000674.pd

    Single hadron response measurement and calorimeter jet energy scale uncertainty with the ATLAS detector at the LHC

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    The uncertainty on the calorimeter energy response to jets of particles is derived for the ATLAS experiment at the Large Hadron Collider (LHC). First, the calorimeter response to single isolated charged hadrons is measured and compared to the Monte Carlo simulation using proton-proton collisions at centre-of-mass energies of sqrt(s) = 900 GeV and 7 TeV collected during 2009 and 2010. Then, using the decay of K_s and Lambda particles, the calorimeter response to specific types of particles (positively and negatively charged pions, protons, and anti-protons) is measured and compared to the Monte Carlo predictions. Finally, the jet energy scale uncertainty is determined by propagating the response uncertainty for single charged and neutral particles to jets. The response uncertainty is 2-5% for central isolated hadrons and 1-3% for the final calorimeter jet energy scale.Comment: 24 pages plus author list (36 pages total), 23 figures, 1 table, submitted to European Physical Journal

    Search for squarks and gluinos in events with isolated leptons, jets and missing transverse momentum at s√=8 TeV with the ATLAS detector

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    The results of a search for supersymmetry in final states containing at least one isolated lepton (electron or muon), jets and large missing transverse momentum with the ATLAS detector at the Large Hadron Collider are reported. The search is based on proton-proton collision data at a centre-of-mass energy s√=8 TeV collected in 2012, corresponding to an integrated luminosity of 20 fb−1. No significant excess above the Standard Model expectation is observed. Limits are set on supersymmetric particle masses for various supersymmetric models. Depending on the model, the search excludes gluino masses up to 1.32 TeV and squark masses up to 840 GeV. Limits are also set on the parameters of a minimal universal extra dimension model, excluding a compactification radius of 1/R c = 950 GeV for a cut-off scale times radius (ΛR c) of approximately 30
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