328 research outputs found

    Geographic routing resilient to location errors

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    Geographic routing is an attractive option for large scale wireless sensor networks (WSNs) because of its low overhead and energy expenditure, but is inefficient in realistic localization conditions. Positioning systems are inevitably imprecise because of inexact range measurements and location errors lead to poor performance of geographic routing in terms of packet delivery ratio (PDR) and energy efficiency. This paper proposes a novel, low-complexity, error-resilient geographic routing method, named conditioned mean square error ratio (CMSER) routing, intended to efficiently make use of existing network information and to successfully route packets when localization is inaccurate. Next hop selection is based on the largest distance to destination (minimizing the number of forwarding hops) and on the smallest estimated error figure associated with the measured neighbor coordinates. It is found that CMSER outperforms other basic greedy forwarding techniques employed by algorithms such as most forward within range (MFR), maximum expectation progress (MEP) and least expected distance (LED). Simulation results show that the throughput for CMSER is higher than for other methods, additionally it also reduces the energy wasted on lost packets by keeping their routing paths short

    Energy efficient geographic routing robust against location errors

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    Realistic geographic routing algorithms need to ensure quality of services in wireless sensor network applications while being resilient to the inherent localization errors of positioning algorithms. A number of solutions robust against location errors have been proposed in the literature and their design focuses either on a high throughput or on a balanced energy consumption. Ideally, both aspects need to be addressed by the same algorithm, but in most cases, the proposed routing techniques compromise between the two. The present work aims to minimize such a tradeoff and to facilitate a higher packet delivery ratio than similar geographic routing techniques, while still being energy efficient. This is achieved through a novel proposal entitled energy conditioned mean square error algorithm (ECMSE), which makes use of statistical assumptions of Gaussianly distributed location error and Ricianly distributed distances between sensor nodes. In addition, it makes use of an energy efficient feature, which includes information about the energy cost of the forwarding decision. By using a location-error-resilient and distance-based power metric, the ECMSE provides an improved performance in realistic simulations in comparison with other error-coping geographic routing algorithms

    Constructing public health policies in post crisis countries: lessons to learn from the associations between free-sugars consumption and diabetes, obesity and dental caries before, during and after sanctions in Iraq.

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    BACKGROUND: This article aims to provide evidence for an informed public health policy on free-sugar consumption in post-crisis countries. METHODS: Iraq was selected as a case study. A systematic search for published data on the prevalence/incidence of type-2 diabetes, overweight/obesity, dental caries and free-sugar consumption levels in Iraq was conducted using MEDLINE, the Iraqi Academic Scientific journals and relevant international organisations' websites. Comparable data before (1980-1990), during (1991-2002) and after (2003-2015) the United Nations sanctions (UNS) were included. RESULTS: Ten studies were included. Quality scores ranged between 3 and 7/8. Free-sugar consumption decreased dramatically during the UNS (from 50 to 16.3 kg/person/year) and started increasing afterwards (24.1 kg/person/year). Changes in type-2 diabetes, overweight/obesity and caries levels mirrored those of free-sugar consumption. Caries declined markedly during UNS and started increasing afterwards. Comparable data on diabetes and overweight/obesity were only available for the periods during and after the UNS. Both of these conditions started increasing with increased free-sugar consumption after lifting the UNS. CONCLUSIONS: There is a need to develop a public health policy in post-crisis countries to maintain the reduction in free-sugar consumption, and hence promote both general and dental health, by integrating the common risk factor approach into the social determinant framework

    Chances and Limitations of Wild Bird Monitoring for the Avian Influenza Virus H5N1 — Detection of Pathogens Highly Mobile in Time and Space

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    Highly pathogenic influenza virus (HPAIV) H5N1 proved to be remarkably mobile in migratory bird populations where it has led to extensive outbreaks for which the true number of affected birds usually cannot be determined. For the evaluation of avian influenza monitoring and HPAIV early warning systems, we propose a time-series analysis that includes the estimation of confidence intervals for (i) the prevalence in outbreak situations or (ii) in the apparent absence of disease in time intervals for specified regional units. For the German outbreak regions in 2006 and 2007, the upper 95% confidence limit allowed the detection of prevalences below 1% only for certain time intervals. Although more than 25,000 birds were sampled in Germany per year, the upper 95% confidence limit did not fall below 5% in the outbreak regions for most of the time. The proposed analysis can be used to monitor water bodies and high risk areas, also as part of an early-warning system. Chances for an improved targeting of the monitoring system as part of a risk-based approach are discussed with the perspective of reducing sample sizes

    L-Glutamine therapy reduces endothelial adhesion of sickle red blood cells to human umbilical vein endothelial cells

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    BACKGROUND: We have previously demonstrated that therapy with orally administered L-glutamine improves nicotinamide adenosine dinucleotide (NAD) redox potential of sickle red blood cells (RBC). On further analysis of L-glutamine therapy for sickle cell anemia patients, the effect of L-glutamine on adhesion of sickle RBC to human umbilical vein endothelial cells (HUVEC) was examined. METHODS: The first part of the experiment was conducted with the blood samples of the 5 adult sickle cell anemia patients who had been on L-glutamine therapy for at least 4 weeks on a dosage of 30 grams per day compared to those of patient control group. In the second part of the experiment 6 patients with sickle cell anemia were studied longitudinally. Five of these patients were treated with oral L-glutamine 30 grams daily and one was observed without treatment as the control. t-test and paired t-test were used for determination of statistical significance in cross-sectional and longitudinal studies respectively. RESULTS: In the first study, the mean adhesion to endothelial cells with the autologous plasma incubated cells were 0.97 ± 0.45 for the treated group and 1.91 ± 0.53 for the nontreated group (p < 0.02). Similarly with lipopolysaccharide (LPS) incubated cells the mean adhesion to endothelial cells were 1.39 ± 0.33 for the treated group and 2.80 ± 0.47 for the untreated group (p < 0.001). With the longitudinal experiment, mean decrease in the adhesion to endothelial cells was 1.13 ± 0.21 (p < 0.001) for the 5 treated patients whereas the control patient had slight increase in the adhesion to endothelial cells. CONCLUSION: In these studies, oral L-glutamine administration consistently resulted in improvement of sickle RBC adhesion to HUVEC. These data suggest positive physiological effects of L-glutamine in sickle cell disease

    Pharmacotherapy and the risk for community-acquired pneumonia

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    <p>Abstract</p> <p>Background</p> <p>Some forms of pharmacotherapy are shown to increase the risk of community-acquired pneumonia (CAP). The purpose of this study is to investigate whether pharmacotherapy with proton pump inhibitors (PPI), inhaled corticosteroids, and atypical antipsychotics was associated with the increased risk for CAP in hospitalized older adults with the adjustment of known risk factors (such as smoking status and serum albumin levels).</p> <p>Methods</p> <p>A retrospective case-control study of adults aged 65 years or older at a rural community hospital during 2004 and 2006 was conducted. Cases (N = 194) were those with radiographic evidence of pneumonia on admission. The controls were patients without the discharge diagnosis of pneumonia or acute exacerbation of chronic obstructive pulmonary disease (COPD) (N = 952). Patients with gastric tube feeding, ventilator support, requiring hemodialysis, metastatic diseases or active lung cancers were excluded.</p> <p>Results</p> <p>Multiple logistic regression analysis revealed that the current use of inhaled corticosteroids (adjusted odds ratio [AOR] = 2.89, 95% confidence interval [CI] = 1.56-5.35) and atypical antipsychotics (AOR = 2.26, 95% CI = 1.23-4.15) was an independent risk factor for CAP after adjusting for confounders, including age, serum albumin levels, sex, smoking status, a history of congestive heart failure, coronary artery disease, and COPD, the current use of PPI, β2 agonist and anticholinergic bronchodilators, antibiotic(s), iron supplement, narcotics, and non-steroidal anti-inflammatory drugs. The crude OR and the AOR of PPI use for CAP was 1.41 [95% CI = 1.03 - 1.93] and 1.18 [95% CI = 0.80 - 1.74] after adjusting for the above confounders, respectively. Lower serum albumin levels independently increased the risk of CAP 1.89- fold by decreasing a gram per deciliter (AOR = 2.89, 95% CI = 2.01 - 4.16).</p> <p>Conclusion</p> <p>Our study reaffirmed that the use of inhaled corticosteroids and atypical antipsychotics was both associated with an increased risk for CAP in hospitalized older adults of a rural community. No association was found between current PPI use and the risk for CAP in this patient population of our study.</p

    Molecular epidemiology of Hepatitis B virus genotypes in Pakistan

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    <p>Abstract</p> <p>Background</p> <p>Eight genotypes of Hepatitis B virus designated A-H, have been known but in Pakistan, no such data is available on the prevalent HBV genotypes. Therefore, the subject study was conducted to determine HBV genotypes in the indigenous Pakistani population.</p> <p>Methods</p> <p>A total of 690 individuals were enrolled for HBV screening with EIA and nested PCR. Positive samples were further analyzed to determine HBV genotypes (A-F) by multiplex-PCR using type specific primers.</p> <p>Results</p> <p>110 (15.94%) individuals were positive for HBV, including 64% males and 36% females. Out of these, 66 samples (65.34%) were classified into genotype D, 27 (26.73%) were of genotype B while 5(4.95%) had genotype A. In 3 (2.98%) samples, multiple genotypes were detected (genotype A+B; 2(1.99%) and genotypes B+D; 1(0.99%). Nine (8.18%) samples remained untyable.</p> <p>Conclusion</p> <p>In Asia, genotypes B and C are the most prevalent but our study reveals that genotype D is predominant and HBV infection constitutes a significant health problem in Pakistan.</p

    Statistical analysis plan for the PlAtelet Transfusion in Cerebral Haemorrhage (PATCH) trial:a multicentre randomised controlled trial

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    Use of antiplatelet therapy shortly before stroke due to spontaneous primary intracerebral haemorrhage (ICH) is associated with higher case fatality in comparison to ICH without prior antithrombotic drug use. The PlAtelet Transfusion in Cerebral Haemorrhage (PATCH) trial aimed to assess the effect of platelet transfusion in patients presenting with ICH while using antiplatelet therapy. The main hypothesis of PATCH was that platelet transfusion would reduce death or dependence by reducing ICH growth. PATCH was a multicentre prospective, randomised, open, blinded endpoint (PROBE) parallel group trial, conducted at 60 hospitals in The Netherlands, Scotland and France. Forty-one sites enrolled 190 patients with spontaneous supratentorial ICH aged ≥18 years, who had used antiplatelet therapy for ≥7 days preceding ICH, if Glasgow Coma Scale was ≥8. Participants were randomised (1:1, with a secure web-based system using permuted blocks, stratified by study centre and type of antiplatelet therapy pre-ICH) to receive either platelet transfusion within 6 hours of symptom onset and 90 minutes of diagnostic brain imaging, or standard care without platelet transfusion. The primary outcome was modified Rankin Scale (mRS) score assessed blind to treatment allocation at 3 months after ICH. Planned secondary outcomes included ICH growth on brain imaging performed approximately 24 hours after randomisation, survival at 3 months, disability at 3 months scored using the Amsterdam Medical Centre linear disability score, heterogeneity of treatment effect on mRS and ICH growth according to presence of the computed tomography angiography spot sign, causes of poor outcome, and cost-effectiveness. Safety outcomes were transfusion reactions, thromboembolic complications, and serious adverse events occurring during hospitalisation. This statistical analysis plan was written without knowledge of the unblinded data. The trial was registered with the Netherlands Trial Register on 29 April 2008 ( NTR1303
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