Central Africa Research Articles

Response of regional circulation features to the Indian Ocean dipole and influence on Central Africa climate

Response of regional circulation features to the Indian Ocean dipole and influence on Central Africa climate

NEW APPROACH TO PROXIMITY ANALYSIS BETWEEN TWO HORIZONTAL MULTI-TABLES: DSCIA2 METHOD

In this paper, we propose a new method called Dual Simultaneous Co-Inertia Analysis Type 2 (DSCIA2), which is both a new approach to DSCIA in the context of two horizontal multi-tables and Dual of SCIA2 method. The aim is to study the variability of the proximity between pairs of tables with the same variables, by constructing the common axes of representation of the variables and the individuals simultaneously, i.e. constructing in one go an orthogonal matrix containing the solutions. An example of this method consisting being studied of the compared economic evolution of the countries of the Economic Monetary Community of Central Africa (EMCCA) and the West African Economic Monetary Union(WAEMU) is given.

Mitogenomic Characterization of South African Leopards and the Effect of Past Climatic Events

Revealing phylogeographic structure is important for accurate subspecies delineation and understanding a species’ evolutionary history. In leopards (Panthera pardus), there are currently nine subspecies recognized. On the African continent, only one subspecies occurs (P. p. pardus), although mitochondrial DNA from historical samples suggests the presence of three putative continental clades: (1) West Africa (WA), (2) Central Africa (CA), and (3) Southern Africa (SA). So far, whole genome data did not recover this phylogeographic structure, although leopards in the southern periphery of their distribution range in Africa have not yet been investigated in detail. The Mpumalanga province of South Africa is of particular interest, as here, the CA and the SA clade possibly meet. The aim of this study was to characterize the first mitogenomes of African leopards from Mpumalanga, to help clarifying how South African leopards fit into continental patterns of genetic differentiation. Complete mitogenomes from nine leopards, including a strawberry leopard, were assembled de novo and included in phylogenetic analysis, in combination with 32 publicly available mitogenomes. Bayesian inference and maximum likelihood analyses identified two deeply diverged putative clades within South Africa, which were more genetically distinct than two subspecies in Asia. The clades dated back to 0.76-0.86 million years ago, indicating that they originated during the climatically unstable Mid-Pleistocene, as seen in other large mammals. The Pleistocene refuge theory states that the maintenance of savanna refugia in East and Southern Africa promoted the divergence between populations. As such, leopards may reflect the unique climatic history of southern Africa, which has resulted in eminent and endemic genetic diversity.

Feasibility, safety, efficacy and potential scaling-up of sofosbuvir-based HCV treatment in Central and West Africa: (TAC ANRS 12311 trial)

Access to Hepatis C treatment in Sub-Saharan Africa is a clinical, public health and ethical concern. The multi-country open-label trial TAC ANRS 12311 allowed assessing the feasibility, safety, efficacy of a specific care model of HCV treatment and retreatment in patients with hepatitis C in Sub Saharan Africa. Between November 2015 and March 2017, with follow-up until mid 2019, treatment-naïve patients with HCV without decompensated cirrhosis or liver cancer were recruited to receive 12 week-treatment with either sofosbuvir + ribavirin (HCV genotype 2) or sofosbuvir + ledipasvir (genotype 1 or 4) and retreatment with sofosbuvir + velpatasvir + voxilaprevir in case of virological failure. The primary outcome was sustained virological response at 12 weeks after end of treatment (SVR12). Secondary outcomes included treatment adherence, safety and SVR12 in patients who were retreated due to non-response to first-line treatment. The model of care relied on both viral load assessment and educational sessions to increase patient awareness, adherence and health literacy. The study recruited 120 participants, 36 HIV-co-infected, and 14 cirrhotic. Only one patient discontinued treatment because of return to home country. Neither death nor severe adverse event occurred. SVR12 was reached in 107 patients (89%): (90%) in genotype 1 or 2, and 88% in GT-4. All retreated patients (n = 13) reached SVR12. HCV treatment is highly acceptable, safe and effective under this model of care. Implementation research is now needed to scale up point-of-care HCV testing and SVR assessment, along with community involvement in patient education, to achieve HCV elimination in Sub-Saharan Africa.

A new Actinella species (Eunotiaceae, Bacillariophyta) from the Yangambi Biosphere Reserve, Democratic Republic of the Congo

Background and aims – Actinella species from Central Africa are only rarely reported. The acid waters from many stream and small rivers in the Congo Basin form a potential environment for species of this genus. We studied several samples from the region of Yangambi to confirm whether species belonging to this genus are present. Material and methods – Samples for diatom investigation were collected in several streams and small rivers (Moni, Ngima, and Libongo), in the tropical rainforest in the Yangambi Biosphere Reserve, Tshopo Province, Democratic Republic of the Congo. The samples were prepared to obtain permanent microscope slides for light microscopy studies using standard methods and cleaned material for scanning electron microscopy. Key results – A novel Actinella was observed in the studied samples. The taxon was compared to other species such as A. disjuncta, A. lange-bertalotii, A. modesta, A. pereunotioides, and A. pseudohantzschia, although the new species morphologically resembles most A. eunotioides, a species discovered in the Amazon basin in Brazil, and A. eunotioides var. minor, described in 1966 from the Central African Republic. The taxon observed in our material differs from A. eunotioides mainly in the valve dimensions, being much smaller, and the higher density of the marginal spines. Stria density also tends to be coarser. The valve length of A. eunotioides var. minor, on the other hand, corresponds with the smallest valves of our taxon but the valves are narrower, with a higher stria density. The ventral margin is slightly convex, while in the new taxon it is slightly concave. Moreover, in the original description of A. eunotioides var. minor, the absence of spines is mentioned, while they are present on the valves in the materials we investigated. Based on the observed morphological differences, we consider the taxon recorded in the streams and small rivers in the Yangambi Biosphere Reserve distinct from A. eunotioides and its var. minor and subsequently, we describe Actinella kufferathiana as a species new to science.

Increasing Fire Activity in African Tropical Forests Is Associated With Deforestation and Climate Change

AbstractFires were historically rare in tropical forests of West and Central Africa, where dense vegetation, rapid decomposition, and high moisture limit available fuels. However, increasing heat and drought combined with forest degradation and fragmentation are making these areas more susceptible to wildfires. We evaluated historical patterns of Moderate Resolution Imaging Spectroradiometer active fires in African tropical forests from 2003 to 2021. Trends were mostly positive, particularly in the northeastern and southern Congo Basin, and were concentrated in areas with high deforestation. Year‐to‐year variation of fires was synchronized with increasing temperature and vapor pressure deficit. There was anomalously high fire activity across the region during the 2015–2016 El Niño. These results contrast with the drier African woodlands and savannas, where fire has been decreasing. Further attention to fires in African tropical forests is needed to understand their global impacts on carbon dynamics and their local implications for biodiversity and human livelihoods.

Measuring the impact of ginning stages on cotton fiber quality in the context of west and central Africa

The ginning process has an effect on fiber quality. Avoiding fiber quality deterioration due to mistune or overspeed is crucial, especially in west and central Africa where value chains are highly dependent on prices paid for premium fiber quality. Indeed, fiber classification alone does not permit a reliable measurement of ginning impact, as it depends on many factors such as incoming seed cotton quality, equipment type, number, and settings within each ginning process stage. This study describes a sampling and analysis method precise enough to detect any commercial impact on fiber quality at each main ginning stage. It is based on fiber quality characteristic measurements before and after each main stage: seed cotton cleaning, ginning, and lint cleaning. The sampling and testing protocol was applied in Mali in seven industrial gins during the 2015–2016 ginning season. Seed cotton samples were taken before and after the seed cotton cleaning stage, and fiber samples before and after the lint cleaning stage. Seed cotton samples were ginned with a reference saw micro-gin. The precision of fiber characterization was measured by replicating twice each fiber sample characterization in a laboratory meeting the international standards. Based on the variability measured in Mali, we determined for each fiber characteristic the number of replicates required to detect any commercially harmful impact. Growing and ginning conditions in Mali are representative of those in west and central Africa. Based on this method, one needs to develop an on-line tool to measure fiber quality at every stage of industrial ginning.

The burden of hospital-acquired infections (HAI) in sub-Saharan Africa: a systematic review and meta-analysis

Hospital-acquired infections (HAI) are a leading cause of morbidity and mortality globally. These infections are diverse, but the majority are lower respiratory tract infection (LRTI), surgical site infection (SSI), bloodstream infection (BSI), and urinary tract infection (UTI). For most sub-Saharan African countries, studies revealing the burden and impact of HAI are scarce, and few systematic reviews and meta-analysis have been attempted. We sought to fill this gap by reporting recent trends in HAI in sub-Saharan Africa (SSA) with attention to key patient populations, geographic variation, and associated mortality. Following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, we conducted a literature search of six electronic databases (Web of Science, Pubmed, APA PsycInfo, CINAHL, Embase, and the Cochrane Library) to identify studies assessing the prevalence of HAI in SSA countries. Studies published between 01 January 2014 and 31 December 2023 were included. We applied no language or publication restrictions. Record screening and data extractions were independently conducted by teams of two or more reviewers. Using the R software (version 4.3.1) meta and metafor packages, we calculated the pooled prevalence estimates from random-effect meta-analysis, and further explored sources of heterogeneity through subgroup analyses and meta-regression. This study is registered with PROSPERO, CRD42023433271. Forty-one relevant studies were identified for analysis, consisting of 15 from West Africa (n=2107), 12 from Southern Africa (n=2963), 11 from East Africa (n=2142), and 3 from Central Africa (n=124). A total of 59.4% of the patient population were associated with paediatric admissions. The pooled prevalence of HAI was estimated at 12.9% (95% CI: 8.9-17.4; n=7336; number of included estimates [k]=41, p<0.001). By subregions, the pooled current prevalence of HAI in the West Africa, Southern Africa, East Africa and Central Africa were estimated at 15.5% (95% CI: 8.3-24.4; n=2107; k=15), 6.5% (95% CI: 3.3-10.7; n=2963; k=12), 19.7% (95% CI: 10.8-30.5; n=2142; k=11) and 10.3% (95% CI: 1.1-27.0; n=124; k=3) of the patient populations respectively. We estimated mortality resulting from HAI in SSA at 22.2% (95% CI: 14.2-31.4; n=1118; k=9). Our estimates reveal a high burden of HAI in SSA with significant heterogeneity between regions. Variations in HAI distribution highlight the need for infection prevention and surveillance strategies specifically tailored to enhance prevention and management with special focus on West and East Africa, as part of the broader global control effort. No funding was received for this study.

Spatial–temporal trends in leprosy burden and its associations with socioeconomic and physical geographic factors: results from the Global Burden of Disease Study 2019

ObjectivesThe purpose of our study was to assess the multiscalar changes in leprosy burden and its associated risk factors over the last three decades. Study designWe conducted an in-depth examination of leprosy's spatial–temporal trends at multiple geographical scale (global, regional, and national), utilizing information from Global Burden of Disease, Injuries, and Risk Factors Study (GBD 2019). MethodsIncidence and the estimated annual percentage change (EAPC) in age-standardized incidence rate (ASIR) of leprosy were determined, with countries categorized based on leprosy incidence changes. We examined socioeconomic and physical geography influences on leprosy incidence via Spearman correlation analysis, using ternary phase diagrams to reveal the synergetic effects on leprosy occurrence. ResultsGlobally, incident cases of leprosy decreased by 27.86% from 1990 to 2019, with a reduction in ASIR (EAPC = −2.53), yet trends were not homogeneous across regions. ASIR and EAPC correlated positively with sociodemographic index (SDI), and an ASIR growth appeared in high SDI region (EAPC = 3.07). Leprosy burden was chiefly distributed in Tropical Latin America, Oceania, Central Sub-Saharan Africa, and South Asia. Negative correlations were detected between the incidence of leprosy and factors of SDI, GDP per capita, urban population to total population, and precipitation, whereas the number of refugee population, temperature, and elevation showed opposite positive results. ConclusionsDespite a global decline in leprosy over the past three decades, the disparities of disease occurrence at regional and national scales still persisted. Socioeconomic and physical geographic factors posed an obvious influence on the transmission risk of leprosy. The persistence and regional fluctuations of leprosy incidence necessitate the ongoing dynamic and multilayered control strategies worldwide in combating this ancient disease.

Genetic Diversity and Detection of Respiratory Viruses Excluding SARS-CoV-2 during the COVID-19 Pandemic in Gabon, 2020–2021

Acute respiratory infections are a major global burden in resource-limited countries, including countries in Africa. Although COVID-19 has been well studied since the pandemic emerged in Gabon, Central Africa, less attention has been paid to other respiratory viral diseases, and very little data are available. Herein, we provide the first data on the genetic diversity and detection of 18 major respiratory viruses in Gabon during the COVID-19 pandemic. Of 582 nasopharyngeal swab specimens collected from March 2020 to July 2021, which were SARS-CoV-2 negative, 156 were positive (26%) for the following viruses: enterovirus (20.3%), human rhinovirus (HRV) (4.6%), human coronavirus OC43 (1.2%), human adenovirus (0.9%), human metapneumovirus (hMPV) (0.5%), influenza A virus (IAV) (0.3%), and human parainfluenza viruses (0.5%). To determine the genetic diversity and transmission route of the viruses, phylogenetic analyses were performed using genome sequences of the detected viruses. The IAV strain detected in this study was genetically similar to strains isolated in the USA, whereas the hMPV strain belonging to the A2b subtype formed a cluster with Kenyan strains. This study provides the first complete genomic sequences of HRV, IAV, and hMPV detected in Gabon, and provides insight into the circulation of respiratory viruses in the country.

The Anopheles coluzzii range extends into Kenya: detection, insecticide resistance profiles and population genetic structure in relation to conspecific populations in West and Central Africa

BackgroundAnopheles coluzzii is a primary vector of malaria found in West and Central Africa, but its presence has hitherto never been documented in Kenya. A thorough understanding of vector bionomics is important as it enables the implementation of targeted and effective vector control interventions. Malaria vector surveillance efforts in the country have tended to focus on historically known primary vectors. The current study sought to determine the taxonomic status of samples collected from five different malaria epidemiological zones in Kenya as well as describe the population genetic structure and insecticide resistance profiles in relation to other An. coluzzii populations.MethodsMosquitoes were sampled as larvae from Busia, Kwale, Turkana, Kirinyaga and Kiambu counties, representing the range of malaria endemicities in Kenya, in 2019 and 2021 and emergent adults analysed using Whole Genome Sequencing (WGS) data processed in accordance with the Anopheles gambiae 1000 Genomes Project phase 3. Where available, historical samples from the same sites were included for WGS. Comparisons were made with An. coluzzii cohorts from West and Central Africa.ResultsThis study reports the detection of An. coluzzii for the first time in Kenya. The species was detected in Turkana County across all three time points from which samples were analyzed and its presence confirmed through taxonomic analysis. Additionally, there was a lack of strong population genetic differentiation between An. coluzzii from Kenya and those from the more northerly regions of West and Central Africa, suggesting they represent a connected extension to the known species range. Mutations associated with target-site resistance to DDT and pyrethroids and metabolic resistance to DDT were found at high frequencies up to 64%. The profile and frequencies of the variants observed were similar to An. coluzzii from West and Central Africa but the ace-1 mutation linked to organophosphate and carbamate resistance present in An. coluzzii from coastal West Africa was absent in Kenya.ConclusionsThese findings emphasize the need for the incorporation of genomics in comprehensive and routine vector surveillance to inform on the range of malaria vector species, and their insecticide resistance status to inform the choice of effective vector control approaches.

Men's education and intimate partner violence-Beyond the victim-oriented perspective: Evidence from demographic and health surveys in Central Africa.

Intimate partner violence (IPV) has increasingly received attention in the last three decades. However, IPV-related studies in both high- and low- and middle-income countries adopted a victim-oriented perspective in which men are perpetrators and women, the victims. Using socio-cultural and resource theories as guiding frameworks, this paper assessed the associations between men's education and IPV in Central Africa, using nationally representative data of married and cohabiting women of reproductive ages. Data included in the analyses come from Demographic and Health Surveys (DHSs) in the Democratic Republic of the Congo (DRC), Cameroon, Gabon, and Chad. Analyzed sub-samples consisted of 3421, 5023, 3930, and 3221 married/cohabiting women of reproductive ages in Chad, DRC, Cameroon, and Gabon, respectively. Findings indicated significant variations of IPV prevalence within and across countries. Previous research demonstrated that men's education is a protective factor in health-related studies. The present study, however, provide no clear evidence on the linkages between men's education and IPV. In contrast, the paper substantiated that highly educated women were at higher risks of IPV when spouses/partners were less educated. These findings have policy and programmatic implications because they might impede progress towards SDG goals on the elimination of all forms of violence against girls and women in Central Africa, which recorded the worst development indicators in sub-Saharan Africa. On a methodological note, studies are increasingly using pooled data to increase statistical power. Those studies can be very limited to devise effective IPV-interventions since they mask geographical variations within and across countries. More effective IPV-interventions should be culturally rooted and accounting for geographical variations because some areas are more affected than others.

Seasonal variations in rain cells propagation over Central Africa and association with diurnal rainfall regimes

AbstractThree‐hourly data from two satellite rainfall estimates products, PERSIANN and TMPA, are analysed to document the seasonal patterns of diurnal rainfall distribution over the Congo Basin and neighbouring areas. PERSIANN data for 2001–2017, at a one‐hour time‐scale, are further used to identify rain cells (≥4 mm·h−1) in an attempt to explain the diurnal rainfall variations. Over land areas, an afternoon rainfall maximum is clearly shown, but over much of the region only a minor part of the rains (20%–30%) falls in the wettest 3‐h period. Substantial rains (often 50%–60%) occur in the evening and at night, as a progressively delayed peak from east to west, but a seasonal change is found in the meridional propagation of the peak diurnal rainfall, in a south‐westerly direction in January, and a north‐westerly direction in July. Rain cells have prominent genesis areas west of high terrain, but can develop over most regions, with a peak genesis time slightly ahead the diurnal phase of the rains. The size, mean lifetime and mean rainfall intensity of the rain cells are strongly related to each other and display a semi‐annual cycle not fully in phase with the seasonal cycle of the rains. The mean rain cell propagation speed (6.7 m·s−1) is much lower than in previous studies, which focused on mesoscale convective systems. Rain cells which have a longer lifetime move much faster, the mean speed of those lasting less than 6 h being half that of those lasting at least 24 h. Most (86%) of the mobile rain cells propagate westward, but the meridional component of their propagation shows an annual cycle (southward in austral summer, northward in boreal summer) which matches the mid‐tropospheric winds and explains the seasonal changes in the diurnal rainfall peak.

Analysis of the spatial mismatch pattern of net carbon in agriculture and its influencing factors

Agricultural production has dual functions as a carbon emitter and sink, and fully exploiting the carbon sink function of agriculture is highly valuable for ensuring carbon neutrality. The layout of net carbon in agriculture shows an imbalance, i.e., underscaling in areas with a net carbon advantage or overscaling in areas with a net carbon disadvantage, which restricts the fulfillment of agricultural carbon sinks. Clarifying the global pattern of net carbon imbalances in agriculture and their drivers is highly important for improving the overall net carbon. In this regard, this paper focuses on the global net carbon in agriculture in 155 countries and regions, and a spatial mismatch index of net carbon in agriculture (MNCA) is constructed based on the relative difference between net carbon and cultivated land. Spatial autocorrelation analysis and the standard deviation ellipse are used to reflect its spatiotemporal evolution pattern. In addition, through geographically weighted regression, we explored the effects of agricultural structure, agricultural economic development, the scale of labor and cultivated land and organized the mismatches into carbon and area effects. The results show that (1) global agricultural production represents net carbon emissions, while developing countries represent net carbon sinks, and there is a mismatch of net agricultural carbon in most regions; (2) the MNCA is characterized by low-low clustering in North America, Asia and Europe, with its center of gravity falling in western Africa and migrating northeastward; and (3) the main factors influencing the MNCA are the agricultural structure and economic level. Underscaling in areas with a net carbon advantage is a major problem. To increase the global agricultural carbon sink capacity, we suggest that North America, South Asia and other regions strictly implement agricultural emission reduction policies and that Central America, South America and Africa tentatively upgrade agricultural technology and their economies to alleviate farmland pressure through transnational cooperation. In this paper, the global net carbon imbalance in agriculture is identified and the overall implementation path of increasing carbon sinks is explored to provide a reference for achieving carbon neutrality. SynopsisThis study reports a global mismatch in net carbon in agriculture and identifies the wasted carbon sink advantage of developing countries as the root problem.

Characterizing the performances of different observational precipitation products and their uncertainties over Africa

Abstract Validation of observed gridded precipitation datasets sourced from satellites or reanalysis over Africa remains a challenge due to the dearth of in-situ products that can act as a true estimate. To address this gap, this study compares the performance of different precipitation products (gauge, reanalysis, and satellite-based) sourced from the Frequent Rainfall Observations on GridS (FROGS) database over Africa. Satellite products are classified as corrected (incorporating gauge observations into their algorithms) or uncorrected, which implies that temporal variations depend entirely on the satellite. The main aim is to identify regions where precipitation (PRE) products depict minimal uncertainties, supporting the use of the datasets in understanding rainfall variability in the specific regions. This is achieved by applying the triple collocation approach, which takes advantage of three collocated datasets of same variable and derive the mean square error without requiring knowledge of the truth. The results show that simulations of light precipitation (1 - 5 mm/day) were prevalent in most regions of Africa during the study duration (2001 - 2016). Estimating the spatial distribution of daily precipitation greater than 90th percentiles suggests that extreme precipitation is mainly detected over the central Africa (CAF) region and coastal regions of west Africa (WAF), where the majority of uncorrected satellite products show consistent performance. The corrected satellite product CMORPH_V1_RAW shows higher estimates of 90th percentile precipitation among the corrected satellite products. The ability of precipitation products to detect rainy or non-rainy days shows that corrected satellite products depict notable agreement for probability of detection (POD) and false alarm ratio (FAR) over most regions of Africa. Overall, better performance is demonstrated by the IMERG products (uncorrected), ARCv2, CHIRPSv2 and PERSIANN_CDRv1r1 (corrected), and GPCC, CPC_v1.0, and REGEN_ALL (gauge) during the study period. The optimal maps that show the classification of products in regions where they depict reliable performance can be recommended for various usages by different stakeholders.

Meta-analysis of the global distribution of clinically relevant CYP2C8 alleles and their inferred functional consequences

Abstract Background CYP2C8 is responsible for the metabolism of 5% of clinically prescribed drugs, including antimalarials, anti-cancer and anti-inflammatory drugs. Genetic variability is an important factor that influences CYP2C8 activity and modulates the pharmacokinetics, efficacy and safety of its substrates. Results We profiled the genetic landscape of CYP2C8 variability using data from 96 original studies and data repositories that included a total of 33,185 unrelated participants across 44 countries and 43 ethnic groups. The reduced function allele CYP2C8*2 was most common in West and Central Africa with frequencies of 16–36.9%, whereas it was rare in Europe and Asia (&lt; 2%). In contrast, CYP2C8*3 and CYP2C8*4 were common throughout Europe and the Americas (6.9–19.8% for *3 and 2.3–7.5% for *4), but rare in African and East Asian populations. Importantly, we observe pronounced differences (&gt; 2.3-fold) between neighboring countries and even between geographically overlapping populations. Overall, we found that 20–60% of individuals in Africa and Europe carry at least one CYP2C8 allele associated with reduced metabolism and increased adverse event risk of the anti-malarial amodiaquine. Furthermore, up to 60% of individuals of West African ancestry harbored variants that reduced the clearance of pioglitazone, repaglinide, paclitaxel and ibuprofen. In contrast, reduced function alleles are only found in &lt; 2% of East Asian and 8.3–12.8% of South and West Asian individuals. Conclusions Combined, the presented analyses mapped the genetic and inferred functional variability of CYP2C8 with high ethnogeographic resolution. These results can serve as a valuable resource for CYP2C8 allele frequencies and distribution estimates of CYP2C8 phenotypes that could help identify populations at risk upon treatment with CYP2C8 substrates. The high variability between ethnic groups incentivizes high-resolution pharmacogenetic profiling to guide precision medicine and maximize its socioeconomic benefits, particularly for understudied populations with distinct genetic profiles.

A data-driven global flood forecasting system for medium to large rivers.

Losses from catastrophic floods are driving intense efforts to increase preparedness and improve response to disastrous flood events by providing early warnings. Yet accurate flood forecasting remains a challenge due to uncertainty in modeling, calibrating, and validating a useful early warning system. This paper presents the Requisitely Simple (ReqSim) flood forecasting system that includes key variables and processes of basin hydrology and atmospheric forcing in a data-driven modeling framework. The simplicity of the modeling structure and data requirements of the system allows for customization and implementation in any medium to large rain-fed river basin globally, provided there are water level or discharge measurements at the forecast locations. The proposed system's efficacy is demonstrated in this paper through providing useful forecasts for various river basins around the world. This include 3-10-day forecasts for the Ganges and Brahmaputra rivers in South Asia, 2-3-day forecast for the Amur and Yangtze rivers in East Asia, 5-10-day forecasts for the Niger, Congo and Zambezi rivers in West and Central Africa, 6-8-day forecasts for the Danube River in Europe, 2-5-day forecasts for the Parana River in South America, and 2-7-day forecasts for the Mississippi, Missouri, Ohio, and Arkansas rivers in the USA. The study also quantifies the effect of basin size, topography, hydrometeorology, and river flow controls on forecast accuracy and lead times. Results indicate that ReqSim's forecasts perform better in river systems with moderate slopes, high flow persistence, and less flow controls. The simple structure, minimal data requirements, ease of operation, and useful operational accuracy make ReqSim an attractive option for effective real-time flood forecasting in medium and large river basins worldwide.

Antimicrobial resistance in bacterial wound, skin, soft tissue and surgical site infections in Central, Eastern, Southern and Western Africa: A systematic review and meta-analysis.

Antimicrobial resistance (AMR) is a major global threat and AMR-attributable mortality is particularly high in Central, Eastern, Southern and Western Africa. The burden of clinically infected wounds, skin and soft tissue infections (SSTI) and surgical site infections (SSI) in these regions is substantial. This systematic review reports the extent of AMR from sampling of these infections in Africa, to guide treatment. It also highlights gaps in microbiological diagnostic capacity. PubMed, MEDLINE and Embase were searched for studies reporting the prevalence of Staphylococcus aureus, Eschericheria coli, Klebsiella pneumoniae, Pseudomonas aeruginosa and Acinetobacter baumannii in clinically infected wounds, SSTI and SSI in Central, Eastern, Southern or Western Africa, and studies reporting AMR from such clinical isolates. Estimates for proportions were pooled in meta-analyses, to estimate the isolation prevalence of each bacterial species and the proportion of resistance observed to each antibiotic class. The search (15th August 2022) identified 601 articles: 59 studies met our inclusion criteria. S. aureus was isolated in 29% (95% confidence interval [CI] 25% to 34%) of samples, E. coli in 14% (CI 11% to 18%), K. pneumoniae in 11% (CI 8% to 13%), P. aeruginosa in 14% (CI 11% to 18%) and A. baumannii in 8% (CI 5% to 12%). AMR was high across all five species. S. aureus was resistant to methicillin (MRSA) in >40% of isolates. E. coli and K. pneumoniae were both resistant to amoxicillin-clavulanic acid in ≥80% of isolates and resistant to aminoglycosides in 51% and 38% of isolates respectively. P. aeruginosa and A. baumannii were both resistant to anti-pseudomonal carbapenems (imipenem or meropenem) in ≥20% of isolates. This systematic review found that a large proportion of the organisms isolated from infected wounds, SSTI and SSI in Africa displayed resistance patterns of World Health Organisation (WHO) priority pathogens for critical or urgent antimicrobial development.

The 4DEnVar-based weakly coupled land data assimilation system for E3SM version 2

Abstract. A new weakly coupled land data assimilation (WCLDA) system based on the four-dimensional ensemble variational (4DEnVar) method is developed and applied to the fully coupled Energy Exascale Earth System Model version 2 (E3SMv2). The dimension-reduced projection four-dimensional variational (DRP-4DVar) method is employed to implement 4DVar using the ensemble technique instead of the adjoint technique. With an interest in providing initial conditions for decadal climate predictions, monthly mean anomalies of soil moisture and temperature from the Global Land Data Assimilation System (GLDAS) reanalysis from 1980 to 2016 are assimilated into the land component of E3SMv2 within the coupled modeling framework with a 1-month assimilation window. The coupled assimilation experiment is evaluated using multiple metrics, including the cost function, assimilation efficiency index, correlation, root-mean-square error (RMSE), and bias, and compared with a control simulation without land data assimilation. The WCLDA system yields improved simulation of soil moisture and temperature compared with the control simulation, with improvements found throughout the soil layers and in many regions of the global land. In terms of both soil moisture and temperature, the assimilation experiment outperforms the control simulation with reduced RMSE and higher temporal correlation in many regions, especially in South America, central Africa, Australia, and large parts of Eurasia. Furthermore, significant improvements are also found in reproducing the time evolution of the 2012 US Midwest drought, highlighting the crucial role of land surface in drought lifecycle. The WCLDA system is intended to be a foundational resource for research to investigate land-derived climate predictability.

SOLUTION OF NONLINEAR PARTIAL DIFFERENTIAL EQUATIONS BY A DEFORMATION BASED SAWI’S TRANSFORM

In this paper, we propose a new method called Dual Simultaneous Co-Inertia Analysis Type 2 (DSCIA2), which is both a new approach to DSCIA in the context of two horizontal multi-tables and Dual of SCIA2 method. The aim is to study the variability of the proximity between pairs of tables with the same variables, by constructing the common axes of representation of the variables and the individuals simultaneously, i.e. constructing in one go an orthogonal matrix containing the solutions. An example of this method consisting being studied of the compared economic evolution of the countries of the Economic Monetary Community of Central Africa (EMCCA) and the West African Economic Monetary Union(WAEMU) is given.