402 research outputs found

    Performance Analysis on Real-Time M-QAM Signal Transmission over a Fog-Induced FSO Link

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    This research conducts a performance analysis on a real-time experimental multi-quadrature amplitude modulation (M-QAM) free-space optical (FSO) system under different fog conditions. The study focuses on experimental investigations to assess the system's tolerance and performance. Experimental results will contribute to a comprehensive understanding of the reliability aspects of the M-QAM FSO system, offering practical insights that are vital for real-world applications in challenging atmospheric conditions

    Whole exome re-sequencing implicates CCDC38 and cilia structure and function in resistance to smoking related airflow obstruction

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    Chronic obstructive pulmonary disease (COPD) is a leading cause of global morbidity and mortality and, whilst smoking remains the single most important risk factor, COPD risk is heritable. Of 26 independent genomic regions showing association with lung function in genome-wide association studies, eleven have been reported to show association with airflow obstruction. Although the main risk factor for COPD is smoking, some individuals are observed to have a high forced expired volume in 1 second (FEV1) despite many years of heavy smoking. We # hypothesised that these ‘‘resistant smokers’’ may harbour variants which protect against lung function decline caused by smoking and provide insight into the genetic determinants of lung health. We undertook whole exome re sequencing of 100 heavy smokers who had healthy lung function given their age, sex, height and smoking history and applied three complementary approaches to explore the genetic architecture of smoking resistance. Firstly, we identified novel functional variants in the ‘‘resistant smokers’’ and looked for enrichment of these novel variants within biological pathways. Secondly, we undertook association testing of all exonic variants individually with two independent control sets. Thirdly, we undertook gene-based association testing of all exonic variants. Our strongest signal of association with smoking resistance for a non-synonymous SNP was for rs10859974 (P = 2.3461024) in CCDC38, a gene which has previously been reported to show association with FEV1/FVC, and we demonstrate moderate expression of CCDC38 in bronchial epithelial cells. We identified an enrichment of novel putatively functional variants in genes related to cilia structure and function in resistant smokers. Ciliary function abnormalities are known to be associated with both smoking and reduced mucociliary clearance in patients with COPD. We suggest that genetic influences on the development or function of cilia in the bronchial epithelium may affect growth of cilia or the extent of damage caused by tobacco smoke

    Performance of CMS hadron calorimeter timing and synchronization using test beam, cosmic ray, and LHC beam data

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    This paper discusses the design and performance of the time measurement technique and of the synchronization systems of the CMS hadron calorimeter. Time measurement performance results are presented from test beam data taken in the years 2004 and 2006. For hadronic showers of energy greater than 100 GeV, the timing resolution is measured to be about 1.2 ns. Time synchronization and out-of-time background rejection results are presented from the Cosmic Run At Four Tesla and LHC beam runs taken in the Autumn of 2008. The inter-channel synchronization is measured to be within ±2 ns

    Facility and home based HIV Counseling and Testing: a comparative analysis of uptake of services by rural communities in southwestern Uganda

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    <p>Abstract</p> <p>Background</p> <p>In Uganda, public human immunodeficiency virus (HIV) Voluntary Counseling and Testing (VCT) services are mainly provided through the facility based model, although the home based approach is being promoted as a strategy for improving access to VCT. However the uptake of VCT varies according to service delivery model and is influenced by a number of factors. The aim of this study therefore, was to compare predictors for uptake of facility and home based VCT in a rural context.</p> <p>Methods</p> <p>A longitudinal study with cross-sectional investigative phases was conducted at two sites (Rugando and Kabingo) in southwestern Uganda between November 2007 (baseline) and March 2008 (follow up). During the baseline visit, facility based VCT was offered at the main health centre in Rugando while home based VCT was offered at the household level in Kabingo and a mixed survey questionnaire administered to the respondents. The results presented in this paper are derived from only the baseline data.</p> <p>Results</p> <p>Nine hundred ninety four (994) respondents were interviewed, of whom 500 received facility based VCT in Rugando and 494 home based VCT in Kabingo during the baseline visit. The respondents had a mean age of 32.2 years (SD 10.9) and were mainly female (68 percent). Clients who received facility based VCT were less likely to be residents of the more rural households (adjusted Odds Ratio (aOR) = 0.14, 95% CI 0.07, 0.22). The clients who received home based VCT were less likely to report having an STI symptom (aOR = 0.63, 95% CI 0.46, 0.86), and more likely to be worried about discrimination if they contracted AIDS (aOR = 1.78, 95% CI 1.22, 2.61).</p> <p>Conclusion</p> <p>The uptake of VCT provided through either the facility or home based models is influenced by client characteristics such as proximity to service delivery points, HIV related symptoms, and fear of discrimination in rural Uganda. Interventions that seek to improve uptake of VCT should provide potential clients with both facility and home based VCT options within a given setting. The clients are then able to select a model for VCT that best fits their characteristics. This is likely to have positive implications for both service coverage and uptake by different sub-groups within particular communities.</p

    π-π stacking tackled with density functional theory

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    Through comparison with ab initio reference data, we have evaluated the performance of various density functionals for describing π-π interactions as a function of the geometry between two stacked benzenes or benzene analogs, between two stacked DNA bases, and between two stacked Watson–Crick pairs. Our main purpose is to find a robust and computationally efficient density functional to be used specifically and only for describing π-π stacking interactions in DNA and other biological molecules in the framework of our recently developed QM/QM approach "QUILD". In line with previous studies, most standard density functionals recover, at best, only part of the favorable stacking interactions. An exception is the new KT1 functional, which correctly yields bound π-stacked structures. Surprisingly, a similarly good performance is achieved with the computationally very robust and efficient local density approximation (LDA). Furthermore, we show that classical electrostatic interactions determine the shape and depth of the π-π stacking potential energy surface

    Gender Dimorphism in Skeletal Muscle Leptin Receptors, Serum Leptin and Insulin Sensitivity

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    To determine if there is a gender dimorphism in the expression of leptin receptors (OB-R170, OB-R128 and OB-R98) and the protein suppressor of cytokine signaling 3 (SOCS3) in human skeletal muscle, the protein expression of OB-R, perilipin A, SOCS3 and alpha-tubulin was assessed by Western blot in muscle biopsies obtained from the m. vastus lateralis in thirty-four men (age = 27.1±6.8 yr) and thirty-three women (age = 26.7±6.7 yr). Basal serum insulin concentration and HOMA were similar in both genders. Serum leptin concentration was 3.4 times higher in women compared to men (P<0.05) and this difference remained significant after accounting for the differences in percentage of body fat or soluble leptin receptor. OB-R protein was 41% (OB-R170, P<0.05) and 163% (OB-R128, P<0.05) greater in women than men. There was no relationship between OB-R expression and the serum concentrations of leptin or 17β-estradiol. In men, muscle OB-R128 protein was inversely related to serum free testosterone. In women, OB-R98 and OB-R128 were inversely related to total serum testosterone concentration, and OB-R128 to serum free testosterone concentration. SOCS3 protein expression was similar in men and women and was not related to OB-R. In women, there was an inverse relationship between the logarithm of free testosterone and SCOS3 protein content in skeletal muscle (r = −0.46, P<0.05). In summary, there is a gender dimorphism in skeletal muscle leptin receptors expression, which can be partly explained by the influence of testosterone. SOCS3 expression in skeletal muscle is not up-regulated in women, despite very high serum leptin concentrations compared to men. The circulating form of the leptin receptor can not be used as a surrogate measure of the amount of leptin receptors expressed in skeletal muscles

    Surface Plasmon Resonance Reveals a Different Pattern of Proinsulin Autoantibodies Concentration and Affinity in Diabetic Patients

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    Type 1 diabetes mellitus (DM) is characterized by autoimmune aggression against pancreatic beta cells resulting in absolute deficiency of insulin secretion. The first detectable sign of emerging autoimmunity during the preclinical asymptomatic period is the appearance of diabetes-related autoantibodies. In children at risk for type 1 DM, high-affinity Insulin autoantibodies reactive to proinsulin, are associated with diabetes risk. Autoantibodies are usually measured by radioligand binding assay (RBA) that provides quasi-quantitative values reflecting potency (product between concentration and affinity) of specific autoantibodies. Aiming to improve the characterization of the specific humoral immune response, we selected surface plasmon resonance (SPR) as an alternative method to measure proinsulin autoantibodies (PAA). This novel technology has allowed real time detection of antibodies interaction and kinetic analysis. Herein, we have employed SPR to characterize the PAA present in sera from 28 childhood-onset (mean age 8.31±4.20) and 23 adult-onset diabetic patients (≥65 years old, BMI<30) in terms of concentration and affinity. When evaluating comparatively samples from both groups, childhood-onset diabetic patients presented lower PAA concentrations and higher affinities (median 67.12×10−9 M and 3.50×107 M−1, respectively) than the adults (median 167.4×10−9 M and 0.84×107 M−1, respectively). These results are consistent with those from the reference method RBA (Standard Deviation score median 9.49 for childhood-onset group and 5.04 for adult-onset group) where the binding can be directly related to the intrinsic affinity of the antibody, suggesting that there is a different etiopathogenic pathway between both types of clinical presentation of the disease. This technology has shown to be a useful tool for the characterization of PAAs parameters as an alternative to radioimmunoassay, with high versatility and reproducibility associated to low occupational and environmental risk. However, this technology is not eligible for routine marker screening, but this is a powerful technique for a fine description of the thermodynamic parameters of antigen-antibody interaction
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