An analysis of spatial percolation structures using a network approach

Includes bibliographical references.In this thesis we analyse several spatial structures, built from percolation models, by means of an approach used so far in the field of network science. In the first chapter we summarize the major network concepts and characterizations that have been obtained as regards the statistical properties of several data sets or theoretical models, We also give a brief introduction to percolation theory and its applications, adding details in two particular cases where mathematical results are available. In the second chapter we then study one particular application of percolation theory to the modelling of distribution and species abundance at different seales. We mainly focus on the way percolation theory was used to compare two diffcrcnt spatial patterns, particularly the random and the aggrergated distribution

Modelling and simulation of electric drive vehicle based on space vector modulation technique and field oriented control strategy

Recently, the electric vehicle has emerged as a powerful platform for mitigating energy crisis and reducing environmental pollution in the transportation sector. The major drawbacks of electrically powered automobile that limits its competitiveness with the internal combustion engine counterpart are the vehicle driving range and battery energy capacity. Hence, limited energy storage warrants the need for an effective and efficient energy utilisation in the overall system. This paper uses Field Oriented Control algorithm and Space Vector Modulation technique to enhance and to optimise energy saving at the same time improve the vehicle induction motor efficiency. A simple electric vehicle drive with vehicle dynamic and tractive loads for motor driving load were modelled and simulated using Matlab/Simulink. Simulation results show that modelled vehicle speed satisfied the acceleration index for the electric vehicle

Does the use of adjunct urine lipopolysaccharide lipoarabinomannan in HIV-infected hospitalized patients reduce the utilization of healthcare resources? A post hoc analysis of the LAM multi-country randomized controlled trial.

BACKGROUND: The World Health Organization (WHO) recommends the use of adjunctive urine lipopolysaccharide lipoarabinomannan (LAM) testing in hospitalized HIV-infected persons with suspected tuberculosis (TB) and a CD4 count <100cells/ml. However, the recommendation is conditional, and uptake by individual treatment programmes depends on perceived additional benefit. The aim of this study was to determine whether adjunctive LAM testing has additional clinical benefits including a reduction in healthcare-related use of resources. METHODS: A post hoc analysis was performed of a published multicentre, multi-country, randomized controlled trial that showed an approximate 20% mortality benefit in HIV-infected hospitalized patients who underwent adjunctive LAM testing as part of their diagnostic workup. In that parent study, adult HIV-infected hospitalized patients with suspected TB (n=2528) were randomly allocated to either routine diagnostics (smear microscopy, Xpert MTB/RIF, and culture; n=1271), or routine diagnostics plus adjunctive urine LAM testing (n=1257). Data were further analyzed to determine whether there were other potential benefits of LAM usage based on CD4 count and illness severity. Aspects evaluated included: (1) the reduction in number of diagnostic sputum samples tested, (2) the utilization of additional imaging, (3) disease resolution based on follow-up signs and symptoms of illness severity, and (4) the reduction in hospital readmission. RESULTS: Adjuvant LAM did not reduce the number of diagnostic sputum samples requested, the need for additional imaging, or the hospital readmission rate. However, adjunctive LAM was associated with a more rapid rate of disease resolution (dyspnoea) in the severely ill subgroup. Higher LAM grade (grades 4 and 5), compared to lower grade positivity (≤3), was associated with lower use of ultrasound, lower Karnofsky performance score, lower CD4 cell count, and shorter time to culture positivity. CONCLUSIONS: Although, adjunct LAM was associated with a mortality benefit in the parent study, no benefit could be demonstrated in the secondary analysis with respect to the number of diagnostic sputum samples requested, the use of additional imaging, or hospital readmission rates. However, given the limitations of the present study, further appropriately designed studies are required to determine the effect of adjunct urine LAM on the utilization of healthcare resources

Efficacy of Pluronic F-127 gel containing green tea catechin extract on chronic periodontitis – A clinical study

Purpose: To evaluate the efficacy of pluronic F-127 gel containing green tea catechin extract as a local drug delivery system in the treatment of chronic periodontitis. Methods: A total of 20 chronic periodontitis patients participated as per the set inclusion and exclusion criteria. Complete scaling and root planing (SRP) was done for all subjects and pluronic F-127 gel containing green tea catechin was applied on one site. The contralateral site received SRP alone. The plaque index (PI), gingival index (GI), and probing pocket depth (PPD) were recorded at baseline and on the 28th day. Results: At the 28th-day follow-up, green tea catechin tooth sites showed significantly lower mean scores (GI = 0.55, p = 0.30 and PPD = 3.35 mm) than the corresponding SRP tooth sites (GI = 1.25, PI = 1.15, and PPD = 4.40 mm) (p &lt; 0.05). Conclusion: When compared to scaling and root planing alone, the local drug delivery gel containing green tea catechin as an adjuvant was more effective in reducing the clinical parameters of periodontitis. Keywords: Adjuvant therapy, Camellia sinensis, Local drug delivery, Periodontal pocke

Heuristic resource allocation algorithm for controller placement in multi-control 5G based on SDN/NFV architecture

The integration of Software Defined Networking (SDN) and Network Function Virtualization (NFV) is considered to be an efficient solution that enables the forecasting of highly scalable, optimal performance of 5G networks by providing an effective means of network functionality. The distributed multi-controller architecture approach is an emerging strategy that primarily aims to support network functions performed through the application of a control plane, to provide versatile network traffic management. However, the management of resource allocations across multiple data centers is an important issue that still affects 5G core networks. Using such a strategy in 5G core networks requires the controllers to be correctly located, in order to improve network reliability and cost-effectiveness. Thus, to address the controller placement problem (CPP) in a distributed 5G network, we proposed an efficient, heuristic multi-objective optimization approach, using dynamic capacitated controller placement problem (DCCPP). It is based on the K-center problem, to solve the capacitated controller placement problem (CCPP), which acts as a resource location problem, in which the location and number of controllers can be allocated to maximize resources. A Greedy Randomized Search (GRS) algorithm was used to solve the dynamic assignment of nodes to controllers to achieve load balancing. The design of the heuristic method provides proper load balancing, efficient cost management, and network resource management, as compared to the basic CCPP model. The results indicate that the allocation and the optimum number of controllers under an effective decentralized policy could achieve a higher degree of efficiency through resource assignment in such a densified network

Knowledge, attitude and practice of hepatitis (B) among healthcare workers in relation to their vaccination status in Khartoum, Sudan, 2015: a cross-sectional study

Background: Hepatitis B is a serious chronic infection of the liver and caused by hepatitis B virus. It is an endemic disease in Sudan. Healthcare workers are occupationally more prone to acquire the disease. Evaluation of their knowledge, attitude and practice and their vaccination status, are very important in the control of the disease. The aim of this study was to assess the knowledge, attitude, and practiceof healthcare workers towards hepatitis B and their vaccination status. Materials and Methods: In total, 372 healthcare workers were enrolled in the study, which was conducted at 10 public hospitals in Khartoum state during July-August 2015. After taking written informed consent from the Khartoum State Research Department, self-administrated questionnaires were distributed to the healthcareworkers. The KAP score was the sum of the three categories, which is 32 points, and the mean was then obtained. Results: The study revealed that the respondents’ mean scores of knowledge, attitude, and practice (KAP) were 18.4, 2.14 and 2.49, respectively. The study also showed that doctors have the highest KAP score in comparison with other occupations. Doctors are the least occupational category that uses gloves when dealing with patient’s blood. The KAP score was found higher among vaccinated healthcare workers 27.4% in comparison to unvaccinated ones, That yield to a significant the association between KAP score and vac-cination status (p-value0.007).Conclusions: This study concluded that, there is a positive association between the level of vaccination among Health care workers and their Knowledge, attitude and practice of hepatitis B virus. Further studies would be recommended on larger population

An Optimal Diagnostic Strategy for Tuberculosis in Hospitalized HIV-Infected Patients Using GeneXpert MTB/RIF and Alere Determine TB LAM Ag.

The diagnosis of tuberculosis (TB) in HIV-infected patients is challenging. Both a urinary lipoarabinomannan (LAM) test (Alere TB LAM) and GeneXpert-MTB/RIF (Xpert) are useful for the diagnosis of TB. However, how to optimally integrate Xpert and LAM tests into clinical practice algorithms remain unclear. We performed a post hoc analysis of 561 HIV-infected sputum-expectorating patients (median CD4 count of 130 cells/ml) from a previously published randomized controlled trial evaluating the LAM test in hospitalized HIV-infected patients with suspected TB. We evaluated 5 different diagnostic strategies using sputum culture as a reference standard (Xpert alone, LAM alone, sequential Xpert followed by LAM and vice versa [LAM in Xpert-negative patients and Xpert in LAM-negative patients], and both tests concurrently [LAM + Xpert]). A cost-consequence analysis was performed. Strategy-specific sensitivity and specificity, using culture as a reference, were similar with the Xpert-only and sequential and concurrent strategies. However, when any positive TB-specific test was used as a reference, the incremental yield of LAM over Xpert was 29.6% (45/152) and that of Xpert over LAM was 75% (84/11). The incremental yield of LAM increased with decreasing CD4 count. The costs per TB case diagnosed were similar for the sequential and concurrent strategies ($1,617 to$1,626). In sputum-expectorating hospitalized patients with advanced HIV and access to both tests, concurrent testing with Xpert and LAM may be the best strategy for diagnosing TB. These data inform clinical practice in settings where TB and HIV are endemic

Distribution and diversity of fish species along the Sudanese Red Sea coast based on three combined trap and gillnet surveys

publishedVersio

Impact of a personalised, digital, HIV self-testing app-based program on linkages and new infections in the township populations of South Africa.

INTRODUCTION: Implementation data for digital unsupervised HIV self-testing (HIVST) are sparse. We evaluated the impact of an app-based, personalised, oral HIVST program offered by healthcare workers in Western Cape, South Africa. METHODS: In a quasirandomised study (n=3095), we recruited consenting adults with undiagnosed HIV infection from township clinics. To the HIVST arm participants (n=1535), we offered a choice of an offsite (home, office or kiosk based), unsupervised digital HIVST program (n=962), or an onsite, clinic-based, supervised digital HIVST program (n=573) with 24/7 linkages services.With propensity score analyses, we compared outcomes (ie, linkages, new HIV infections and test referrals) with conventional HIV testing (ConvHT) arm participants (n=1560), recruited randomly from geographically separated clinics. RESULTS: In both arms, participants were young (HIVST vs ConvHT) (mean age: 28.2 years vs 29.2 years), female (65.0% vs 76.0%) and had monthly income <3000 rand (80.8% vs 75%).Participants chose unsupervised HIVST (62.7%) versus supervised HIVST and reported multiple sex partners (10.88% vs 8.7%), exposure to sex workers (1.4% vs 0.2%) and fewer comorbidities (0.9% vs 1.9%). Almost all HIVST participants were linked (unsupervised HIVST (99.7%), supervised HIVST (99.8%) vs ConvHT (98.5%)) (adj RR 1.012; 95% CI 1.005 to 1.018) with new HIV infections: overall HIVST (9%); supervised HIVST (10.9%) and unsupervised HIVST (7.6%) versus ConvHT (6.79%) (adj RR 1.305; 95% CI 1.023 to 1.665); test referrals: 16.7% HIVST versus 3.1% ConvHT (adj RR 5.435; 95% CI 4.024 to 7.340). CONCLUSIONS: Our flexible, personalised, app-based HIVST program, offered by healthcare workers, successfully linked almost all HIV self-testers, detected new infections and increased referrals to self-test. Data are relevant for digital HIVST initiatives worldwide