Efficiency of wastewater treatment by a mixture of sludge and microalgae

A combined system using the microalgae from South Africa and the sewage sludge from Algeria has been tested, in order to study the efficiency of wastewater treatment by mixtures of microalgae / activated sludge, five bioreactors were installed with different inoculation rates (microalgae / activated sludge) B1: 100% algae, B2: 90.90%: 9.1%, B3: 83.33%: 16.67%, B4: 50%: 50% and B5: 16.67: 83.33. The best removal percentages were measured as: 76.36% for PO4-P, 94.90% for NO3-N, 90.42% for NH4-N and 65.73% for COD, in the combined system. Except in the case of COD, there were highly significant effects of different inoculations rates on yield. The best results are those of the bioreactor B5. These results suggest that the nutrients in the wastewater can be effectively eliminated by co-cultivation of micro-algae with bacteria (activated sludge)

Defining indicators for disease burden, health outcomes, policies and barriers and facilitators to health services for migrant populations in the Middle East and North African region: a protocol for a suite of systematic reviews.

INTRODUCTION: The Middle East and North African (MENA) region is characterised by high and complex migration flows, yet little is known about the health of migrant populations, their levels of underimmunisation and access to healthcare provision. Data are needed to support regional elimination and control targets for key diseases and the design and delivery of programmes to improve health outcomes in these groups. This protocol describes a suite of seven systematic reviews that aim to identify, appraise and synthesise the available evidence on the burden and health outcomes, policies and access (barriers and facilitators) related to these mobile populations in the region. METHODS: Seven systematic reviews will cover three questions to explore the: (1) burden and health outcomes, (2) policies and (3) healthcare barriers and facilitators for the following seven disease areas in migrants in the MENA region: tuberculosis, HIV and hepatitis B and C, malaria and neglected tropical diseases, diabetes, mental health, maternal and neonatal health, and vaccine-preventable diseases. We will search electronic databases for studies in any language (year 2000-2023), reference-check relevant publications and cross-check included studies with experts. We will search for grey literature by hand searching key databases and websites (including regional organisations and MoH websites) for country-specific guidelines and talking to our network of experts for local and regional reports and key datasets. We will assess the studies and policies for their quality using appropriate tools. We will meta-analyse the data by disease outcome if they are of sufficient volume and similarity. Where meta-analysis is not possible and where data are on policy or access, we will narratively synthesise the evidence using summary tables, figures and text. DISSEMINATION: We anticipate disseminating the findings through peer-reviewed publications, conferences and other formats relevant to all stakeholders. We are following Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines and protocols will be registered on International Prospective Register of Systematic Reviews

Delivering in‐school interventions to improve dietary behaviours amongst 11‐ to 16‐year‐olds: A systematic review

Childhood obesity is a global health concern, which has both short‐and long‐term health consequences for the individual, and is a potential burden on health care services and the wider economy. The school environment is a setting where changes can be applied to dietary behaviours, as schools have direct and intensive contact with children. This systematic review evaluated school‐based interventions designed to improve dietary behaviours among adolescents (11‐to 16‐year‐olds). The aims were to review types of interventions delivered, dietary behaviours targeted, and interventions' effectiveness in improving dietary behaviour and associated intervention components. Twenty‐nine school‐based interventional studies with this population were identified for review. The data were synthesized by identifying and comparing individual studies' results, intervention components, and characteristics.Interventions appeared more effective when they involved peers, used educational media to deliver health messages, increased availability of healthy foods in school,and incorporated computer‐based individualized feedback with normative information on eating behaviours. A limitation of the review was the lack of description in cer-tain reviewed studies and the nonfeasibility of conducting a meta‐analysis owing to study heterogeneity. Future interventions with this population could consider including the aforementioned components, gender‐specific feedback, and both short‐and long‐term follow‐ups as change may not be apparent immediately and to determine if changes are sustained

The evolving SARS-CoV-2 epidemic in Africa: Insights from rapidly expanding genomic surveillance

INTRODUCTION Investment in Africa over the past year with regard to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) sequencing has led to a massive increase in the number of sequences, which, to date, exceeds 100,000 sequences generated to track the pandemic on the continent. These sequences have profoundly affected how public health officials in Africa have navigated the COVID-19 pandemic. RATIONALE We demonstrate how the first 100,000 SARS-CoV-2 sequences from Africa have helped monitor the epidemic on the continent, how genomic surveillance expanded over the course of the pandemic, and how we adapted our sequencing methods to deal with an evolving virus. Finally, we also examine how viral lineages have spread across the continent in a phylogeographic framework to gain insights into the underlying temporal and spatial transmission dynamics for several variants of concern (VOCs). RESULTS Our results indicate that the number of countries in Africa that can sequence the virus within their own borders is growing and that this is coupled with a shorter turnaround time from the time of sampling to sequence submission. Ongoing evolution necessitated the continual updating of primer sets, and, as a result, eight primer sets were designed in tandem with viral evolution and used to ensure effective sequencing of the virus. The pandemic unfolded through multiple waves of infection that were each driven by distinct genetic lineages, with B.1-like ancestral strains associated with the first pandemic wave of infections in 2020. Successive waves on the continent were fueled by different VOCs, with Alpha and Beta cocirculating in distinct spatial patterns during the second wave and Delta and Omicron affecting the whole continent during the third and fourth waves, respectively. Phylogeographic reconstruction points toward distinct differences in viral importation and exportation patterns associated with the Alpha, Beta, Delta, and Omicron variants and subvariants, when considering both Africa versus the rest of the world and viral dissemination within the continent. Our epidemiological and phylogenetic inferences therefore underscore the heterogeneous nature of the pandemic on the continent and highlight key insights and challenges, for instance, recognizing the limitations of low testing proportions. We also highlight the early warning capacity that genomic surveillance in Africa has had for the rest of the world with the detection of new lineages and variants, the most recent being the characterization of various Omicron subvariants. CONCLUSION Sustained investment for diagnostics and genomic surveillance in Africa is needed as the virus continues to evolve. This is important not only to help combat SARS-CoV-2 on the continent but also because it can be used as a platform to help address the many emerging and reemerging infectious disease threats in Africa. In particular, capacity building for local sequencing within countries or within the continent should be prioritized because this is generally associated with shorter turnaround times, providing the most benefit to local public health authorities tasked with pandemic response and mitigation and allowing for the fastest reaction to localized outbreaks. These investments are crucial for pandemic preparedness and response and will serve the health of the continent well into the 21st century

New developments of penalty methods for simulating turbulent flows interacting with obstacles

International audienc

Predictors of smoking initiation among schoolchildren in Tunisia: a 4 years cohort study

Objective: To identify predictors of smoking initiation among non smoking Tunisian school children; and to propose efficient antismoking strategies in order to prevent smoking initiation. Methods: It was a cohort study surveying prospectively for four years pupils attending schools in Sousse city in Tunisia. 441 non smoking pupils aged 13-15 years attending secondary schools in Sousse. Data were collected by a self administered questionnaire during class session. Two ways cross tabulation, univariate and multivariate logistic regression analyses were the main analytical methods. Results: 57.1% of the surveyed population were girls, 42.9 % were boys. 63% had at least one of their peers who smoked. Before 1999, 16.6% had already tried to smoke, 29.5% had already experienced alcohol. In 2003, smoking prevalence was 17%. 4.8% were girls; 33.3% of boys; p<0,001). 69.9 % of these smokers declared that they would carry on smoking during the following five years. Predictors which were highly associated with smoking initiation were previous experimentation with alcohol and tobacco, having a smoking best friend, lack of sensitization from the part of the school, believing that smoking makes one feel cool and that tobacco shouldn&apos;t be forbidden in public places. Conclusion: Intervention programs should target young children to avoid experiencing the first cigarette. Multidisciplinary management including community and school based intervention highlighted by mass media campaigns may provide schoolchildren with skills to resist smoking peers prompts to adopt unhealthy habits such as smoking

Estimated lung age in healthy North African adults cannot be predicted using reference equations derived from other populations

Introduction: Interpretation of “lung age” data relies upon comparison of the chronological lung age (CLA) with the estimated lung age (ELA) predicted from published reference equations [7–10]. Aim: To test the applicability of the published reference equations in healthy non-smoker Tunisian aged 19–90 years. Population and methods: Published reference equations were applied to the spirometry results of 540 adults (364 women). Two methods of comparison were applied: (i) Determination, according each equation, of the percentages of subjects having a deltaLungAge (=ELA–CLA) > Upper-Limit-of-Normal (ULN). (ii) Bland and Altman comparison, for the same age range as in the corresponding study, between CLA and ELA. Results: The mean ± SD (95% confidence interval) of the total sample CLA and height were 48.8 ± 13.1 (47.7–49.9) years and 164 ± 10 (163–165) cm. (i) The percentages of healthy subjects with a deltaLungAge > ULN varied from 1% (Newbury) to 64% (Hansen) in men, and from 20% (Yamaguchi) to 51% (Hansen, Morris and Temple) for women. (ii) Mean ± SD ELA was significantly underestimated by 17 ± 19 years (Hansen), by 12 ± 23 years (Morris and Temple) and was significantly overestimated by 4 ± 19 years (Newbury). Mean ± SD ELA from Yamaguchi et al. [10] was not statistically different from the CLA (1 ± 14 years). Conclusion: The published reference equations did not reliably predict CLA data in the Tunisian population. Awaiting the establishment of reliable equation proper to North African population, we recommend the use of the Yamaguchi et al.’s [10] reference equations