941 research outputs found
Epidemic malaria and warmer temperatures in recent decades in an East African highland
Climate change impacts on malaria are typically assessed with scenarios for the long-term future. Here we focus instead on the recent past (1970â2003) to address whether warmer temperatures have already increased the incidence of malaria in a highland region of East Africa. Our analyses rely on a new coupled mosquitoâhuman model of malaria, which we use to compare projected disease levels with and without the observed temperature trend. Predicted malaria cases exhibit a highly nonlinear response to warming, with a significant increase from the 1970s to the 1990s, although typical epidemic sizes are below those observed. These findings suggest that climate change has already played an important role in the exacerbation of malaria in this region. As the observed changes in malaria are even larger than those predicted by our model, other factors previously suggested to explain all of the increase in malaria may be enhancing the impact of climate change
Copyright and cultural work: an exploration
This article first discusses the contemporary debate on cultural âcreativityâ and the economy. Second, it considers the current state of UK copyright law and how it relates to cultural work. Third, based on empirical research on British dancers and musicians, an analysis of precarious cultural work is presented. A major focus is how those who follow their art by way of âportfolioâ work handle their rights in ways that diverge significantly from the current simplistic assumptions of law and cultural policy. Our conclusions underline the distance between present top-down conceptions of what drives production in the cultural field and the actual practice of dancers and musicians
Assessment of laser cladding as an option for repairing/enhancing rails
This paper presents results of testing carried out to assess the wear and RCF performance of laser clad rail. Stronger and harder materials can be laser clad on top of the working surfaces of standard (e.g. 260 grade) rail in order to improve wear and RCF life. A twin-disc method has been used to assess the suitability of various candidate cladding materials. The materials were clad on top of 260 grade rail discs and were tested against a disc of standard wheel material. Wear was measured by weighing the discs before and after each test. An Ellotest B1 differential eddy current crack detector was used to detect RCF cracks in the rail disc. Four clad materials were used namely, Hadfield, Stellite 6, Maraging and 316 Stainless Steels. In the tests carried out, wear was not always reduced with the cladding. It is assumed that these tests were not long enough for some of the materials to fully work harden and therefore wear rates would improve with a greater number of test cycles. However, all but the Stainless Steel showed that they did not deform under the cyclic loading applied and would offer a greatly enhanced RCF life
Process evaluation of a sport-for-health intervention to prevent smoking amongst primary school children: SmokeFree Sports
Background: SmokeFree Sports (SFS) was a multi-component sport-for-health intervention aiming at preventing smoking among nine to ten year old primary school children from North West England. The purpose of this study was to evaluate the process and implementation of SFS, examining intervention reach, dose, fidelity, acceptability and sustainability, in order to understand the feasibility and challenges of delivering such interventions and inform interpretations of intervention effectiveness. Methods: Process measures included: booking logs, 18 focus groups with children (n=95), semi-structured interviews with teachers (n=20) and SFS coaches (n=7), intervention evaluation questionnaires (completed by children, n=1097; teachers, n=50), as well direct observations (by researchers, n=50 observations) and self-evaluations (completed by teachers, n=125) of intervention delivery (e.g. length of sessions, implementation of activities as intended, children's engagement and barriers). Descriptive statistics and thematic analysis were applied to quantitative and qualitative data, respectively. Results: Overall, SFS reached 30.8% of eligible schools, with 1073 children participating in the intervention (across 32 schools). Thirty-one schools completed the intervention in full. Thirty-three teachers (55% female) and 11 SFS coaches (82% male) attended a bespoke SFS training workshop. Disparities in intervention duration (range=126 to 201 days), uptake (only 25% of classes received optional intervention components in full), and the extent to which core (mean fidelity score of coaching sessions=58%) and optional components (no adaptions made=51% of sessions) were delivered as intended, were apparent. Barriers to intervention delivery included the school setting and children's behaviour and knowledge. SFS was viewed positively (85% and 82% of children and teachers, respectively, rated SFS five out of five) and recommendations to increase school engagement were provided. Conclusion: SFS was considered acceptable to children, teachers and coaches. Nevertheless, efforts to enhance intervention reach (at the school level), teachers' engagement and sustainability must be considered. Variations in dose and fidelity likely reflect challenges associated with complex intervention delivery within school settings and thus a flexible design may be necessary. This study adds to the limited scientific evidence base surrounding sport-for-health interventions and their implementation, and suggests that such interventions offer a promising tool for engaging children in activities which promote their health
The effects of acute high-intensity interval exercise and hyperinsulinemic-euglycemic clamp on osteoglycin levels in young and middle-aged men
Osteoglycin (OGN) is a leucine-rich proteoglycan that has been implicated in the regulation of glucose in animal models. However, its relationship with glucose control in humans is unclear. We examined the effect of high-intensity interval exercise (HIIE) and hyperinsulinemic-euglycemic clamp on circulating levels of OGN as well as whether circulating OGN levels are associated with markers of glycemic control and cardio-metabolic health. Serum was analyzed for OGN (ELISA) levels from 9 middle-aged obese men (58.1 ± 2.2 years, body mass index [BMI] = 33.1 ± 1.4 kgâm â 2, mean ± SEM) and 9 young men (27.8 ± 1.6 years, BMI = 24.4 ± 0.08 kgâm â 2) who previously completed a study involving a euglycemic-hyperinsulinemic clamp at rest and after HIIE (4 x 4 minutes cycling at approximately 95% peak heart rate (HRpeak), interspersed with 2 minutes of active recovery). Blood pressure, body composition (dual-energy X-ray absorptiometry), and insulin sensitivity (hyperinsulinemic-euglycemic clamp) were assessed. Serum OGN was higher in the young cohort compared with the middle-aged cohort (65.2 ± 10.1 ng/mL versus 36.5 ± 4. 5 ng/mL, p †0.05). Serum OGN was unaffected by acute HIIE but decreased after the insulin clamp compared with baseline (~ â 27 %, p = 0.01), post-exercise (~ â 35 %, p = 0.01), and pre-clamp (~ â 32 %, p = 0.02) time points, irrespective of age. At baseline, lower circulating OGN levels were associated with increased age, BMI, and fat mass, whereas higher OGN levels were related to lower fasting glucose. Higher OGN levels were associated with a higher glucose infusion rate. Exercise had a limited effect on circulating OGN. The mechanisms by which OGN affects glucose regulation should be explored in the future
Substantiating a political public sphere in the Scottish press : a comparative analysis
This article uses content analysis to characterize the performance of the media in a national public sphere, by setting apart those qualities that typify internal press coverage of a political event. The article looks at the coverage of the 1999 devolved Scottish election from the day before the election until the day after. It uses a word count to measure the election material in Scottish newspapers the Herald, the Press and Journal and the Scotsman, and United Kingdom newspapers the Guardian, the Independent and The Times, and categorizes that material according to discourse type, day and page selection. The article finds a number of qualities that typify the Scottish sample in particular, and might be broadly indicative of a political public sphere in action. Firstly, and not unexpectedly, it finds that the Scottish newspapers carry significantly more election coverage. Just as tellingly, though, the article finds that the Scottish papers offer a greater proportion of advice and background information, in the form of opinion columns and feature articles. It also finds that the Scottish papers place a greater concentration of both informative and evaluative material in the period before the vote, consistent with their making a contribution to informed political action. Lastly, the article finds that the Scottish sample situates coverage nearer the front of the paper and places a greater proportion on recto pages. The article therefore argues that the Scottish papers display features that distinguish them from the UK papers, and are broadly consistent with their forming part of a deliberative public sphere, and suggests that these qualities might be explored as a means of judging future media performance
EHMTI-0026. Neuroprolotherapy and acupuncture for clinical trial of acute and chronic migraine treatment
Nicotinic acid adenine dinucleotide phosphate (NAADP) and cyclic ADP-ribose (cADPR) are Ca2+-mobilizing messengers important for modulating cardiac excitationâcontraction coupling and pathophysiology. CD38, which belongs to the ADP-ribosyl cyclase family, catalyzes synthesis of both NAADP and cADPR in vitro. However, it remains unclear whether this is the main enzyme for their production under physiological conditions. Here we show that membrane fractions from WT but not CD38â/â mouse hearts supported NAADP and cADPR synthesis. Membrane permeabilization of cardiac myocytes with saponin and/or Triton X-100 increased NAADP synthesis, indicating that intracellular CD38 contributes to NAADP production. The permeabilization also permitted immunostaining of CD38, with a striated pattern in WT myocytes, whereas CD38â/â myocytes and nonpermeabilized WT myocytes showed little or no staining, without striation. A component of ÎČ-adrenoreceptor signaling in the heart involves NAADP and lysosomes. Accordingly, in the presence of isoproterenol, Ca2+ transients and contraction amplitudes were smaller in CD38â/â myocytes than in the WT. In addition, suppressing lysosomal function with bafilomycin A1 reduced the isoproterenol-induced increase in Ca2+ transients in cardiac myocytes from WT but not CD38â/â mice. Whole hearts isolated from CD38â/â mice and exposed to isoproterenol showed reduced arrhythmias. SAN4825, an ADP-ribosyl cyclase inhibitor that reduces cADPR and NAADP synthesis in mouse membrane fractions, was shown to bind to CD38 in docking simulations and reduced the isoproterenol-induced arrhythmias in WT hearts. These observations support generation of NAADP and cADPR by intracellular CD38, which contributes to effects of ÎČ-adrenoreceptor stimulation to increase both Ca2+ transients and the tendency to disturb heart rhythm
Fitness costs of disrupting circadian rhythms in malaria parasites
Circadian biology assumes that biological rhythms maximize fitness by enabling organisms to coordinate with their environment. Despite circadian clocks being such a widespread phenomenon, demonstrating the fitness benefits of temporal coordination is challenging and such studies are rare. Here, we tested the consequencesâfor parasitesâof being temporally mismatched to host circadian rhythms using the rodent malaria parasite, Plasmodium chabaudi. The cyclical nature of malaria infections is well known, as the cell cycles across parasite species last a multiple of approximately 24 h, but the evolutionary explanations for periodicity are poorly understood. We demonstrate that perturbation of parasite rhythms results in a twofold cost to the production of replicating and transmission stages. Thus, synchronization with host rhythms influences in-host survival and between-host transmission potential, revealing a role for circadian rhythms in the evolution of hostâparasite interactions. More generally, our results provide a demonstration of the adaptive value of circadian rhythms and the utility of using an evolutionary framework to understand parasite traits
Association of specific chromosome alterations with tumour phenotype in posterior uveal melanoma
Posterior uveal melanomas have recurrent alterations of chromosomes 1, 3, 6 and 8. In particular, changes of chromosomes 3 and 8 occur in association, appear to characterize those tumours with a ciliary body component, and have been shown to be of prognostic significance. The relevance of other chromosome alterations is less certain. We have performed cytogenetic analysis on 42 previously untreated primary posterior uveal melanomas. Of interest was the observation that as tumour size increased the involvement of specific chromosome changes, and the amount of chromosome abnormalities likewise increased. Loss, or partial deletions, of the short arm of chromosome 1 were found to associate with larger ciliary body melanomas; typically, loss of the short arm resulted from unbalanced translocations, the partners of which varied. Trisomy of chromosome 21 occurred more often in ciliary body melanomas, whilst rearrangements of chromosomes 6 and 11 were primarily related to choroidal melanomas. Our results imply that alterations of chromosome 1 are important in the progression of some uveal melanomas, and that other chromosome abnormalities, besides those of chromosomes 3 and 8, are associated with ocular tumours of particular locations. © 2000 Cancer Research Campaig
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