616 research outputs found
Enhancing weak transient signals in SEVIRI false color imagery: application to dust source detection in southern Africa
A method is described to significantly enhance the signature of dust events using observations
from the Spinning Enhanced Visible and InfraRed Imager (SEVIRI). The approach involves the derivation of a
composite clear-sky signal for selected channels on an individual time step and pixel basis. These composite
signals are subtracted from each observation in the relevant channels to enhance weak transient signals
associated with either (a) low levels of dust emission or (b) dust emissions with high salt or low quartz
content. Different channel combinations, of the differenced data from the steps above, are then rendered in
false color imagery for the purpose of improved identification of dust source locations and activity. We have
applied this clear-sky difference (CSD) algorithm over three (globally significant) source regions in southern
Africa: the Makgadikgadi Basin, Etosha Pan, and the Namibian and western South African coast. Case study
analyses indicate three notable advantages associated with the CSD approach over established image
rendering methods: (i) an improved ability to detect dust plumes, (ii) the observation of source activation
earlier in the diurnal cycle, and (iii) an improved ability to resolve and pinpoint dust plume source locations
EPUAP classification system for pressure ulcers: European reliability study
‘The definitive version is available at www3.interscience.wiley.com .' Copyright Blackwell PublishingPeer reviewe
Lymphatic endothelial cells are a replicative niche for Mycobacterium tuberculosis
In extrapulmonary tuberculosis, the most common site of infection is within the lymphatic system, and there is growing recognition that lymphatic endothelial cells (LECs) are involved in immune function. Here, we identified LECs, which line the lymphatic vessels, as a niche for Mycobacterium tuberculosis in the lymph nodes of patients with tuberculosis. In cultured primary human LECs (hLECs), we determined that M. tuberculosis replicates both in the cytosol and within autophagosomes, but the bacteria failed to replicate when the virulence locus RD1 was deleted. Activation by IFN-γ induced a cell-autonomous response in hLECs via autophagy and NO production that restricted M. tuberculosis growth. Thus, depending on the activation status of LECs, autophagy can both promote and restrict replication. Together, these findings reveal a previously unrecognized role for hLECs and autophagy in tuberculosis pathogenesis and suggest that hLECs are a potential niche for M. tuberculosis that allows establishment of persistent infection in lymph nodes
Residual cognitive deficits 50 years after lead poisoning during childhood
The long term neurobehavioural consequences of childhood lead poisoning are not known. In this study adult subjects with a documented history of lead poisoning before age 4 and matched controls were examined with an abbreviated battery of neuropsychological tests including measures of attention, reasoning, memory, motor speed, and current mood. The subjects exposed to lead were inferior to controls on almost all of the cognitive tasks. This pattern of widespread deficits resembles that found in children evaluated at the time of acute exposure to lead rather than the more circumscribed pattern typically seen in adults exposed to lead. Despite having completed as many years of schooling as controls, the subjects exposed to lead were lower in lifetime occupational status. Within the exposed group, performance on the neuropsychological battery and occupational status were related, consistent with the presumed impact of limitations in neuropsychological functioning on everyday life. The results suggest that many subjects exposed to lead suffered acute encephalopathy in childhood which resolved into a chronic subclinical encephalopathy with associated cognitive dysfunction still evident in adulthood. These findings lend support to efforts to limit exposure to lead in childhood
A match-day analysis of the movement profiles of substitutes from a professional soccer club before and after pitch-entry.
Whilst the movement demands of players completing a whole soccer match have been well-documented, comparable information relating to substitutes is sparse. Therefore, this study profiled the match-day physical activities performed by soccer substitutes, focusing separately on the pre and post pitch-entry periods. Seventeen English Championship soccer players were monitored using 10 Hz Micromechanical Electrical Systems (MEMS) devices during 13 matches in which they participated as substitutes (35 observations). Twenty physical variables were examined and data were organised by bouts of warm-up activity (pre pitch-entry), and five min epochs of match-play (post pitch-entry). Linear mixed modelling assessed the influence of time (i.e., 'bout' and 'epoch'), playing position, and match scoreline. Substitutes performed 3±1 rewarm-up bouts∙player-1∙match-1. Compared to the initial warm-up, each rewarm-up was shorter (-19.7 to -22.9 min) and elicited less distance (-606 to -741 m), whilst relative total distances were higher (+26 to +69 m∙min-1). Relative total (+13.4 m∙min-1) and high-speed (+0.4 m∙min-1) distances covered during rewarm-ups increased (p <0.001) with proximity to pitch-entry. Players covered more (+3.2 m; p = 0.047) high-speed distance per rewarm-up when the assessed team was losing compared with when winning at the time of pitch-entry. For 10 out of 20 variables measured after pitch-entry, values reduced from 0-5 min thereafter, and substitutes covered greater (p ˂0.05) total (+67 to +93 m) and high-speed (+14 to +33 m) distances during the first five min of match-play versus all subsequent epochs. Midfielders covered more distance (+41 m) per five min epoch than both attackers (p ˂0.001) and defenders (p = 0.016). Acknowledging the limitations of a solely movement data approach and the potential influence of other match-specific factors, such findings provide novel insights into the match-day demands faced by substitute soccer players. Future research opportunities exist to better understand the match-day practices of this population
Abundances of the elements in the solar system
A review of the abundances and condensation temperatures of the elements and
their nuclides in the solar nebula and in chondritic meteorites. Abundances of
the elements in some neighboring stars are also discussed.Comment: 42 pages, 11 tables, 8 figures, chapter, In Landolt- B\"ornstein, New
Series, Vol. VI/4B, Chap. 4.4, J.E. Tr\"umper (ed.), Berlin, Heidelberg, New
York: Springer-Verlag, p. 560-63
Patient reported barriers are associated with low physical and mental well-being in patients with co-morbid diabetes and chronic kidney disease
BACKGROUND:Little is known about how patient reported barriers to health care impact the quality of life (HRQoL) of patients with comorbid disease. We investigated patient reported barriers to health care and low physical and mental well-being among people with diabetes and chronic kidney disease (CKD). METHODS:Adults with diabetes and CKD (estimated Glomerular Filtration Rate < 60 ml/min/1.73m2) were recruited and completed a questionnaire on barriers to health care, the 12-Item HRQoL Short Form Survey and clinical assessment. Low physical and mental health status were defined as mean scores < 50. Logistic regression models were used. RESULTS:Three hundred eight participants (mean age 66.9 ± 11 years) were studied. Patient reported 'impact of the disease on family and friends' (OR 2.07; 95% CI 1.14 to 3.78), 'feeling unwell' (OR 4.23; 95% CI 1.45 to 12.3) and 'having other life stressors that make self-care a low priority' (OR 2.59; 95% CI 1.20 to 5.61), were all associated with higher odds of low physical health status. Patient reported 'feeling unwell' (OR 2.92; 95% CI 1.07 to 8.01), 'low mood' (OR 2.82; 95% CI 1.64 to 4.87) and 'unavailability of home help' (OR 1.91; 95% CI 1.57 to 2.33) were all associated with higher odds of low mental health status. The greater the number of patient reported barriers the higher the odds of low mental health but not physical health status. CONCLUSIONS:Patient reported barriers to health care were associated with lower physical and mental well-being. Interventions addressing these barriers may improve HRQoL among people with comorbid diabetes and CKD.Edward Zimbudzi, Clement Lo, Sanjeeva Ranasinha, Gregory Fulcher, Martin Gallagher, Stephen Jan, Peter G. Kerr, Helena J. Teede, Kevan R. Polkinghorne, Grant Russell, Rowan G. Walker, and Sophia Zounga
Continuum-mechanical, Anisotropic Flow model for polar ice masses, based on an anisotropic Flow Enhancement factor
A complete theoretical presentation of the Continuum-mechanical, Anisotropic
Flow model, based on an anisotropic Flow Enhancement factor (CAFFE model) is
given. The CAFFE model is an application of the theory of mixtures with
continuous diversity for the case of large polar ice masses in which induced
anisotropy occurs. The anisotropic response of the polycrystalline ice is
described by a generalization of Glen's flow law, based on a scalar anisotropic
enhancement factor. The enhancement factor depends on the orientation mass
density, which is closely related to the orientation distribution function and
describes the distribution of grain orientations (fabric). Fabric evolution is
governed by the orientation mass balance, which depends on four distinct
effects, interpreted as local rigid body rotation, grain rotation, rotation
recrystallization (polygonization) and grain boundary migration (migration
recrystallization), respectively. It is proven that the flow law of the CAFFE
model is truly anisotropic despite the collinearity between the stress deviator
and stretching tensors.Comment: 22 pages, 5 figure
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