107 research outputs found
A National Perspective on the Factors Involved in the Lack of E-commerce in Algeria
The major goal of this work is to identify the key factors that affect e-commerce adoption in Algeria from macro perspective. In order to do so, four main infrastructures extracted from literature review have been used to determine the nature of the barriers that have prevented e-commerce from taking off as expected and to explain why Algeria lags behind other countries with similar economic conditions. The results of this investigation demonstrate that, although most of the infrastructures are still growing, but the country still lags behind in terms of its capabilities for providing the required infrastructure for e-commerce
Designing Ranking System for Chinese Product Search Engine Based on Customer Reviews
With the spread of e-commerce platforms, it becomes extremely difficult for the costumer to choose the right product from a large number of products, and different sellers based only on his/her own experience, product picture and meta-data. Customer’s reviews present a rich source of information that have an enormous impact on the purchasing decision of the potential consumers, but reading all of the available reviews is a hard task and time consuming. Thus, the automated mining of these reviews and extract product features in order to generate a raking system present a valuable and useful tool for consumers to make well-versed decision. In this paper, we propose a product search ranking mechanism based on costumers reviews written in Chinese language. We score each product using the features extracted from the reviews. Also, a ranking function has been developed. The proposed research evaluated using customer reviews of two famous brands of mobile phones: Apple and Samsung from taobao.com. The evaluation shows a promising result compared to the existing systems
Molecular diversity and high virulence of Legionella pneumophila strains isolated from biofilms developed within a warm spring of a thermal spa.
International audienceABSTRACT: BACKGROUND: Several cases of legionellosis have been diagnosed in the same French thermal spa in 1986, 1994 and 1997. L. pneumophila serogroup 1 (Lp1) strains have been isolated from several patients, but the source of contamination was not identified despite the presence of different Lp1 in water samples of the three natural springs feeding the spa at this period. RESULTS: Our strategy was to investigate L. pneumophila (Lp) strains from natural biofilms developed in a sulphur-rich warm spring of this contaminated site. Biofilm analysis revealed the presence of three Lp serogroups (Lp1, Lp10 and Lp12). Surprisingly, Lp10 and Lp12 were not reported in the previous described studies from water samples. Besides, the new seven Lp1 we isolated exhibit a high molecular diversity and have been differentiated in five classes according to their DNA genome patterns obtained by PFGE and mip sequences. It must be noted that these DNA patterns are original and unknown in databases. Interestingly, the 27 Lp environmental strains we isolated display a higher cytotoxicity and virulence towards the amoeba Acanthamoeba castellanii than those of known Lp1 epidemic strains. CONCLUSION: The characteristics of Legionella pneumophila Lp1 strains isolated from the warm spring are in agreement with their presence in biofilms and their probable long-term persistence in this ecosystem
Systematic Overview of Hepatitis C Infection in the Middle East and North Africa
AIM: To assess the quality of and to critically synthesize the available data on hepatitis C infections in the Middle East and North Africa (MENA) region to map evidence gaps. METHODS: We conducted an overview of systematic reviews (SRs) following an a priori developed protocol (CRD42017076736). Our overview followed the preferred reporting items for systematic reviews and meta-analyses guidelines for reporting SRs and abstracts and did not receive any funding. Two independent reviewers systematically searched MEDLINE and conducted a multistage screening of the identified articles. Out of 5758 identified articles, 37 SRs of hepatitis C virus (HCV) infection in populations living in 20 countries in the MENA region published between 2008 and 2016 were included in our overview. The nine primary outcomes of interest were HCV antibody (anti-) prevalences and incidences in different at-risk populations; the HCV viremic (RNA positive) rate in HCV-positive individuals; HCV viremic prevalence in the general population (GP); the prevalence of HCV co-infection with the hepatitis B virus, human immunodeficiency virus, or schistosomiasis; the HCV genotype/subtype distribution; and the risk factors for HCV transmission. The conflicts of interest declared by the authors of the SRs were also extracted. Good quality outcomes reported by the SRs were defined as having the population, outcome, study time and setting defined as recommended by the PICOTS framework and a sample size \u3e 100. RESULTS: We included SRs reporting HCV outcomes with different levels of quality and precision. A substantial proportion of them synthesized data from mixed populations at differing levels of risk for acquiring HCV or at different HCV infection stages (recent and prior HCV transmissions). They also synthesized the data over long periods of time (e.g., two decades). Anti-HCV prevalence in the GP varied widely in the MENA region from 0.1% (study dates not reported) in the United Arab Emirates to 2.1%-13.5% (2003-2006) in Pakistan and 14.7% (2008) in Egypt. Data were not identified for Bahrain, Jordan, or Palestine. Good quality estimates of anti-HCV prevalence in the GP were reported for Algeria, Djibouti, Egypt, Iraq, Morocco, Pakistan, Syria, Sudan, Tunisia, and Yemen. Anti-HCV incidence estimates in the GP were reported only for Egypt (0.8-6.8 per 1000 person-year, 1997-2003). In Egypt, Morocco, and the United Arab Emirates, viremic rates in anti-HCV-positive individuals from the GP were approximately 70%. In the GP, the viremic prevalence varied from 0.7% (2011) in Saudi Arabia to 5.8% (2007-2008) in Pakistan and 10.0% (2008) in Egypt. Anti-HCV prevalence was lower in blood donors than in the GP, ranging from 0.2% (1992-1993) in Algeria to 1.7% (2005) in Yemen. The reporting quality of the outcomes in blood donors was good in the MENA countries, except in Qatar where no time framework was reported for the outcome. Some countries had anti-HCV prevalence estimates for children, transfused patients, contacts of HCV-infected patients, prisoners, sex workers, and men who have sex with men. CONCLUSION: A substantial proportion of the reported outcomes may not help policymakers to develop micro-elimination strategies with precise HCV infection prevention and treatment programs in the region, as nowcasting HCV epidemiology using these data is potentially difficult. In addition to providing accurate information on HCV epidemiology, outcomes should also demonstrate practical and clinical significance and relevance. Based on the available data, most countries in the region have low to moderate anti-HCV prevalence. To achieve HCV elimination by 2030, up-to-date, good quality data on HCV epidemiology are required for the GP and key populations such as people who inject drugs and men who have sex with men
Global population-level association between herpes simplex virus 2 prevalence and HIV prevalence.
BACKGROUND: Our objective was to assess the population-level association between herpes simplex virus 2 (HSV-2) and HIV prevalence. METHODS: Reports of HSV-2 and HIV prevalence were systematically reviewed and synthesized following PRISMA guidelines. Spearman rank correlation ((Equation is included in full-text article.)) was used to assess correlations. Risk ratios (RRHSV-2/HIV) and odds ratios (ORHSV-2/HIV) were used to assess HSV-2/HIV epidemiologic overlap. DerSimonian-Laird random-effects meta-analyses were conducted. RESULTS: In total, 939 matched HSV-2/HIV prevalence measures were identified from 77 countries. HSV-2 prevalence was consistently higher than HIV prevalence. Strong HSV-2/HIV prevalence association was found for all data ((Equation is included in full-text article.) = 0.6, P < 0.001), all data excluding people who inject drugs (PWID) and children ((Equation is included in full-text article.) = 0.7, P < 0.001), female sex workers ((Equation is included in full-text article.) = 0.5, P < 0.001), and MSM ((Equation is included in full-text article.) = 0.7, P < 0.001). No association was found for PWID ((Equation is included in full-text article.) = 0.2, P = 0.222) and children ((Equation is included in full-text article.) = 0.3, P = 0.082). A threshold effect was apparent where HIV prevalence was limited at HSV-2 prevalence less than 20%, but grew steadily with HSV-2 prevalence for HSV-2 prevalence greater than 20%. The overall pooled mean RRHSV-2/HIV was 5.0 (95% CI 4.7-5.3) and ORHSV-2/HIV was 9.0 (95% CI 8.4-9.7). The RRHSV-2/HIV and ORHSV-2/HIV showed similar patterns that conveyed inferences about HSV-2 and HIV epidemiology. CONCLUSION: HSV-2 and HIV prevalence are strongly associated. HSV-2 prevalence can be used as a proxy 'biomarker' of HIV epidemic potential, acting as a 'temperature scale' of the intensity of sexual risk behavior that drive HIV transmission. HSV-2 prevalence can be used to identify populations and/or sexual networks at high-risk of future HIV expansion, and help prioritization, optimization, and resource allocation of cost-effective prevention interventions
Factors associated with perceived stress in Middle Eastern university students.
OBJECTIVE University students face high levels of stress-related factors, such as an unfamiliar environment, challenging workload, and uncertainty about their ability to succeed. Participants: A total of 370 students in Qatar who consented to participate between February 2017 and February 2018. Methods: This cross-sectional study assessed perceived stress [using a validated 4-point perceived stress scale (PSS-4)], as well as diet, exercise, body mass index, sleep, and life satisfaction. Results: Among students aged 18-39 (mean = 20.1 ± 3.0 years), PSS-4 scores varied between 0 and 16 (mean = 7.4 ± 3.4). Elevated stress was significantly associated with female sex, country of origin, residing off-campus, eating when bored, lack of self-discipline, disturbed sleep, and low levels of life satisfaction. Furthermore, students with PSS-4 scores above the median level were 2.3 times likelier to report difficulty concentrating on academic work. Conclusion: Elevated stress levels are present in university students in Qatar. Strengthening coping skills may improve health and academic performance
Epidemiology of hepatitis C virus among hemodialysis patients in the Middle East and North Africa: systematic syntheses, meta-analyses, and meta-regressions.
We aimed to investigate hepatitis C virus (HCV) epidemiology among hemodialysis (HD) patients in the Middle East and North Africa (MENA). Our data source was an HCV biological measures database populated through systematic literature searches. Descriptive epidemiologic syntheses, effects meta-analyses and meta-regressions, and genotype analyses were conducted. We analyzed 289 studies, including 106 463 HD patients. HCV incidence ranged between 0 and 100% as seroconversion risk, and between 0 and 14·7 per 1000 person-years as incidence rate. The regional pooled mean estimate was 29·2% (95% CI: 25·6-32·8%) for HCV antibody positive prevalence and 63·0% (95% CI: 55·4-70·3%) for the viremic rate. Region within MENA, country income group, and year of data collection were associated with HCV prevalence; year of data collection adjusted odds ratio was 0·92 (95% CI: 0·90-0·95). Genotype diversity varied across countries with four genotypes documented regionally: genotype 1 (39·3%), genotype 2 (5·7%), genotype 3 (29·6%), and genotype 4 (25·4%). Our findings showed that one-third of HD patients are HCV antibody positive and one-fifth are chronic carriers and can transmit the infection. However, HCV prevalence is declining. In context of growing HD patient population and increasing HCV treatment availability, it is critical to improve standards of infection control in dialysis and expand treatment coverage
Protocol for a systematic review and meta-analysis of hepatitis C virus (HCV) prevalence and incidence in the Horn of Africa sub-region of the Middle East and North Africa.
BACKGROUND: In the Middle East and North Africa (MENA), hepatitis C virus (HCV) distribution appears to present a wide range of prevalence. The scale and nature of HCV disease burden is poorly known in the Horn of Africa sub-region of MENA including Djibouti, Somalia, and Sudan in addition to Yemen at the southwest corner of the Arabian Peninsula. The aim of this review is to provide a systematic review and synthesis of all epidemiological data on HCV prevalence and incidence among the different population groups in this sub-region of MENA. A second aim of the study is to estimate the national population-level HCV prevalence for each of these four countries. METHODS/DESIGN: The systematic review will be conducted based on the items outlined in the PRISMA statement. PubMed, Embase, and the World Health organization (WHO) regional databases will be searched for eligible studies without language or date restrictions. Observational and intervention studies reporting data on the prevalence or incidence of HCV in any population group in Djibouti, Somalia, Sudan, or Yemen will be included. Additional sources will be obtained through the database of the MENA HIV/AIDS Epidemiology Synthesis Project, including international organizations' reports and country-level reports, and abstracts of international conferences. Study and population characteristics will be extracted from eligible publications, with previously agreed pro formas; and entered into a computerized database. We will pool prevalence using DerSimonian and Laird random-effects models after a Freeman-Tukey transformation to stabilize variances. We will conduct meta-regression analysis to explore the effect of study-level characteristics as potential sources of heterogeneity. DISCUSSION: This proposed systematic review and meta-analysis aims to better describe HCV infection distribution across countries in the Horn of Africa sub-region of MENA; and between sub-population groups within each country. The study will provide empirical evidence necessary for researchers, policy-makers, and public health stakeholders to set research, policy, and programming priorities for HCV prevention, control, and treatment. SYSTEMATIC REVIEW REGISTRATION: PROSPERO CRD42014010318
Hepatitis C virus genotypes in the Middle East and North Africa: Distribution, diversity, and patterns.
Our objective was to characterize the distribution, diversity and patterns of hepatitis C virus (HCV) genotypes in the Middle East and North Africa (MENA). Source of data was a database of HCV genotype studies in MENA populated using a series of systematic literature searches. Pooled mean proportions were estimated for each genotype and by country using DerSimonian-Laird random-effects meta-analyses. Genotype diversity within countries was assessed using Shannon Diversity Index. Number of chronic infections by genotype and country was calculated using the pooled proportions and country-specific numbers of chronic infection. Analyses were conducted on 338 genotype studies including 82 257 genotyped individuals. Genotype 1 was dominant (≥50%) in Algeria, Iran, Morocco, Oman, Tunisia, and UAE, and was overall ubiquitous across the region. Genotype 2 was common (10-50%) in Algeria, Bahrain, Libya, and Morocco. Genotype 3 was dominant in Afghanistan and Pakistan. Genotype 4 was dominant in Egypt, Iraq, Jordan, Palestine, Qatar, Saudi Arabia, and Syria. Genotypes 5, 6, and 7 had limited or no presence across countries. Genotype diversity varied immensely throughout MENA. Weighted by population size, MENA's chronic infections were highest among genotype 3, followed by genotype 4, genotype 1, genotype 2, genotype 5, and genotype 6. Despite ubiquitous presence of genotype 1, the vast majority of chronic infections were of genotypes 3 or 4, because of the sizable epidemics in Pakistan and Egypt. Three sub-regional patterns were identified: genotype 3 pattern centered in Pakistan, genotype 4 pattern centered in Egypt, and genotype 1 pattern ubiquitous in most MENA countries
Hepatitis C virus viremic rate in the Middle East and North Africa: Systematic synthesis, meta-analyses, and meta-regressions.
OBJECTIVES: To estimate hepatitis C virus (HCV) viremic rate, defined as the proportion of HCV chronically infected individuals out of all ever infected individuals, in the Middle East and North Africa (MENA). METHODS: Sources of data were systematically-gathered and standardized databases of the MENA HCV Epidemiology Synthesis Project. Meta-analyses were conducted using DerSimonian-Laird random-effects models to determine pooled HCV viremic rate by risk population or subpopulation, country/subregion, sex, and study sampling method. Random-effects meta-regressions were conducted to identify predictors of higher viremic rate. RESULTS: Analyses were conducted on 178 measures for HCV viremic rate among 19,593 HCV antibody positive individuals. In the MENA region, the overall pooled mean viremic rate was 67.6% (95% CI: 64.9-70.3%). Across risk populations, the pooled mean rate ranged between 57.4% (95% CI: 49.4-65.2%) in people who inject drugs, and 75.5% (95% CI: 61.0-87.6%) in populations with liver-related conditions. Across countries/subregions, the pooled mean rate ranged between 62.1% (95% CI: 50.0-72.7%) and 70.4% (95% CI: 65.5-75.1%). Similar pooled estimates were further observed by risk subpopulation, sex, and sampling method. None of the hypothesized population-level predictors of higher viremic rate were statistically significant. CONCLUSIONS: Two-thirds of HCV antibody positive individuals in MENA are chronically infected. Though there is extensive variation in study-specific measures of HCV viremic rate, pooled mean estimates are similar regardless of risk population or subpopulation, country/subregion, HCV antibody prevalence in the background population, or sex. HCV viremic rate is a useful indicator to track the progress in (and coverage of) HCV treatment programs towards the set target of HCV elimination by 2030
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