Descriptive Epidemiology of HIV Risk Factors Among Men: Chad Vs Cameroon

Introduction HIV remains a severe global health problem. The Republic of Chad is moderately affected (1.3%), compared to Cameroon who suffers more of the burden of the HIV/AIDS (4.5%). We described the HIV risk factors in two neighboring Central African Republics, and compared the gaps in both countries. Methods This was a retrospective cross-sectional study; data was obtained from the Demographic and Health Survey. A stratified multi-stage cluster sample design was conducted. The sample size was 5248 in Chad and 7191 in Cameroon. We used SAS to fit a multilevel logistic model, and conducted a multivariate analysis. Results The median age of respondents was 30 (IQR, 20-40) years in Chad, and 28 (IQR, 20-40) in Cameroon. Only 12.45% reported had ever been tested for HIV in Chad, (41.77% in Cameroon). In Chad, 46.40% of participants did not know a place to get HIV test, (11.15% in Cameroon). The median number of lifetime sexual partners was 2 (IQR, 1-4) in Chad, and 6 (IQR, 3-15) in Cameroon. Among Chadian participants 31.63% had only one lifetime sexual partner, (10.76% in Cameroon). In Chad 86.95% of participants reported having no sex partner other than their spouse in the last 12 months; (57.3% in Cameroon). Conclusion Condom use and HIV testing rates were very low among Chadian men comparing to Cameroonian men; however, Cameroonian men were more likely to engage in multiple sexual partners and extra-marital relationship than Chadian men

Survey of Results on the Schrodinger Operator with Inverse Square Potential

In this paper we present a survey of results on the Schrodinger operator with Inverse ¨ Square potential, La= −∆ + a/|x|^2 , a ≥ −( d−2/2 )^2. We briefly discuss the long-time behavior of solutions to the inter-critical focusing NLS with an inverse square potential(proof not provided). Later we present spectral multiplier theorems for the operator. For the case when a ≥ 0, we present the multiplier theorem from Hebisch [12]. The case when 0 \u3e a ≥ −( d−2/2 )^2 was explored in [1], and their proof will be presented for completeness. No improvements on the sharpness of their proof as been obtained

Using Techno-Economic Assessments to Determine the Degree of Centralization in Municipal Wastewater Infrastructure in the Context of Urban Environments

Rapid urbanization, aging infrastructure, high energy demand, and water scarcity challenge the strong reliance and sustainability of centralized municipal wastewater infrastructure. On the other hand, decentralized wastewater treatment systems (DWWTS) have gained popularity as a potential cost-effective alternative compared to costly (capital, operational, and maintenance) centralized wastewater treatment systems (CWWTS). However, determining the extent to which a municipal wastewater infrastructure should be centralized remains a daunting task. Previous studies have attempted to numerically characterize the degree of centralization within areas that have existing infrastructure. Unfortunately, no study has been conducted to determine the degree of centralization for areas without extensive existing infrastructure. This research aims to assess the viability of various decentralized treatment systems, in the context of urban cities with high population densities and potential of water scarcity, by comparing their economic and environmental performances to centralized wastewater infrastructure. Using two wastewater modeling and simulation softwares (GPS-X and CapdetWorks), the technical and economic performance of DWWTs are compared to that of CWWTs. Both suspended and attached growth treatment processes were analyzed. Examples of suspended growth treatment processes include conventional activated sludge (CAS), sequencing batch reactors (SBR) and membrane bioreactor (MBR). Examples of attached growth treatment processes analyzed included trickling filter (TF), rotating biological contactor (RBC) and integrated fixed-film activated sludge (IFAS). This research’s main conclusion is that when keeping the technical performance constant, it is cost-prohibitive to decentralize municipal wastewater infrastructure. This is primarily because when the influent flow is halved, the total treatment cost is not halved. It takes almost the same treatment unit ops to treat half of the flow as it would take to treat the full flow

Rationalisation de contrats de services en imagerie médicale

Rapport présenté en vue de l’obtention du grade de Maîtrise ès sciences appliquées (M. Sc. A.) en génie biomédical, option génie cliniqueLes interventions en imagerie médicale sont extrêmement variées, de nature complexe, mais grandement impératives au diagnostic d’un patient. Nul besoin d’insister sur le fait que l’ingénierie derrière les systèmes d’imagerie diagnostique par résonance magnétique, par rayons-x, par ultrasons et autres, est très élaborée. Au sein d’un même établissement hospitalier, plusieurs milliers d’examens impliquant ces technologies sont exécutés, chaque jour. C’est pour cette raison, entre autres, que les interruptions de service ciblant ce type d’équipement sont irrecevables. Il est chose commune de constater qu’au sein d’un même établissement de santé, plusieurs équipements de nature similaire peuvent être adjoints à des contrats de services irrationnellement distincts. C’est une des raisons pour laquelle la gestion des activités d’entretien des équipements médicaux spécialisés et les contrats qui chapeautent ces derniers sont non négligeables. Le manque de lignes conductrices quant à une gestion efficace et rationnelle de contrats tels que ceux destinés aux secteurs connexes à l’imagerie médicale influence directement les volets administratif, technique et clinique des centres hospitaliers. Le moyen de rationalisation des contrats de service principalement étudié dans ce document est le contrat de service global multi-vendeur. Peu de documentation sur le sujet, notamment dans le domaine de la santé, génère le besoin d’une procédure globale d’implantation prenant en considération les nombreux enjeux impliqués. L’étude réalisée et les solutions qui y sont proposées s’appliquent non seulement aux équipements destinés au secteur de l’imagerie médicale, mais bien tout autre équipement sujet à des contrats de services.Medical imaging activities are extremely diverse, complex, but crucial to the diagnosis of a patient. There is no need to emphasize that the engineering behind the magnetic resonance, x-ray, γ scan, ultrasound and other diagnostic imaging systems, is profoundly elaborated. Under the roof of most health centers, several thousand examinations involving these technologies are performed, every day. For this reason, among others, it is unacceptable for this type of equipment to be the subject of repetitive service interruptions. It is common to note that within the same health facility, similar equipment can be paired to irrationally distinct service agreements. This is one of the reasons why the management of specialized medical equipment maintenance activities and the contracts that governs them should not be overlooked. The lack of conductive lines for an effective and rational management of contracts such as those related to medical imaging directly affects the administrative, technical and clinical aspects of hospitals. This document mainly studies the multi-vendor service agreement format as a mean of rationalizing multiple service contracts in the medical imaging field. Little documentation on the subject, particularly regarding healthcare, generates the need for a global enhancement procedure that takes into account the many issues involved. The solutions proposed therein apply not only to equipment intended for the medical imaging discipline, but also to any other equipment subject to service agreements

QTL and systems genetics analysis of mouse grooming and behavioral responses to novelty in an open field

International audienceThe open field is a classic test used to assess exploratory behavior, anxiety, and locomotor activity in rodents. Here we mapped quantitative trait loci (QTLs) underlying behaviors displayed in an open field, using a panel of 53 BXD recombinant inbred mouse strains with deep replication (10 per strain and sex). The use of these strains permits the integration and comparison of data obtained in different laboratories, and also offers the possibility to study trait covariance by exploiting powerful bioinformatics tools and resources. We quantified behavioral traits during 20 min test sessions including (1) percent time spent and distance travelled near the wall (thigmotaxis), (2) leaning against the wall, (3) rearing, (4) jumping, (5) grooming duration, (6) grooming frequency, (7) locomotion, and (8) defecation. All traits exhibit moderate heritability making them amenable to genetic analysis. We identified a significant QTL on chromosome M.m. 4 at ~104 Mb that modulates grooming duration in both males and females (LRS values of ~18, explaining 25% and 14% of the variance, respectively) and a suggestive QTL modulating locomotion that maps to the same locus. Bioinformatic analysis indicates Disabled 1 (Dab1, a key protein in the reelin signaling pathway) as a particularly strong candidate gene modulating these behaviors. We also found two highly suggestive QTLs for a sex by strain interaction for grooming duration on chromosomes 13 and 17. In addition, we identified a pairwise epistatic interaction between loci on chromosomes 12 at 36-37 Mb and 14 at 34-36 Mb that influences rearing frequency in males

Snake prices and crocodile appetites: Aquatic wildlife supply and demand on Tonle Sap Lake, Cambodia

Commercial trade is a major driver of over-exploitation of wild species, but the pattern of demand and how it responds to changes in supply is poorly understood. Here we explore the markets for snakes from Tonle Sap Lake in Cambodia to evaluate future exploitation scenarios, identify entry points for conservation and, more generally, to illustrate the value of multi-scale analysis of markets to traded wildlife conservation. In Cambodia, the largest driver of snake exploitation is the domestic trade in snakes as crocodile food. We estimate that farmed crocodiles consume between 2.7 and 12.2 million snakes per year. The market price for crocodiles has been in decline since 2003, which, combined with rising prices for their food, has led to a reduced frequency of feeding and closure of small farms. The large farms that generate a disproportionate amount of the demand for snakes continue to operate in anticipation of future market opportunities, and preferences for snakes could help maintain demand if market prices for crocodiles rise to pre 2003 levels. In the absence of a sustained demand from crocodile farms, it is also possible that alternative markets will develop, such as one for human snack food. The demand for snakes, however, also depends on the availability of substitute resources, principally fish. The substitutability and low price elasticity of demand offers a relatively sustainable form of consumerism. Given the nature of these market drivers, addressing consumer preferences and limiting the protection of snakes to their breeding season are likely to be the most effective tools for conservation. This study highlights the importance of understanding the structure of markets and the behaviour of consumer demand prior to implementing regulations on wildlife hunting and trade