It’s that time of the year again when we find ourselves reflecting on the year that was and the year ahead.On the African continent,many countries are still recovering from the aftershocks of the COVID-19 pandemic an...It’s that time of the year again when we find ourselves reflecting on the year that was and the year ahead.On the African continent,many countries are still recovering from the aftershocks of the COVID-19 pandemic and are doing so amid a fraught geopolitical environment.These tensions have,to some extent,created hurdles in the path of Africa’s recovery.The African Development Bank has attributed the economic slowdown on the continent toastronomical inflation caused by soaring food andenergy prices. These issues have been aggravatedby the current geopolitical chaos and climatechange. Nevertheless, the continent is projectedto grow at a steady rate of 4.3 percent in 2025.This means that Africa will retain its positionas the fastest-growing region after Asia. This isdriven by several positive factors.展开更多
We analysed nine simulations from dynamic downscaling to a horizontal resolution of approximately 25 km of three general circulation models (GCMs). These GCMs use three regional climate models (RCMs) that participated...We analysed nine simulations from dynamic downscaling to a horizontal resolution of approximately 25 km of three general circulation models (GCMs). These GCMs use three regional climate models (RCMs) that participated in the coordinated downscaling experiment (CORDEX-CORE). These simulations were compared to three datasets of reanalysis. The ERA5 for temperature at 2 metres and for precipitation, Climate Hazards Center InfraRed Precipitation with Stations (CHIRPS) and African Rainfall Climatology from the Famine Early Warning System (FEWS-ARC) were used. To give an overview of these nine model experiments, we presented and compared the results of the latter with the reanalysis taken into account for the period 1983 - 2005. The results indicated that the nine models correctly reproduced the temperature and rainfall in West Africa during the historical period. In the Guinean coast region, REMO-NorESM1 and RegCM4-MPI-MR models well simulated precipitation and temperature during the historical period. In the Savannah region, RegCM4-NorESM1, CCLM5-MPI-LR, REMO-NorESM1, CCLM5-NorESM1 and CCLM5-HadGEM2 model gave best result. In the Sahel region, the RegCM4-HadGEM2 model gave a good correlation. Using the Taylor diagram in the historical period, all CORDEX-CORE RCMs had a strong relationship with temperature.展开更多
The interannual variability of Normalized Difference Vegetation Index (NDVI) over East Africa demonstrates the complex interactions between vegetation dynamics and climatic factors. This study, which spans the period ...The interannual variability of Normalized Difference Vegetation Index (NDVI) over East Africa demonstrates the complex interactions between vegetation dynamics and climatic factors. This study, which spans the period from 1983 to 2022, makes use of data from NOAA, ERA5, and CRU. It employs a range of statistical techniques, including the calculation of standardized anomalies, significance testing, composites and correlation analyses. The results demonstrated an increase in NDVI over regions including Kenya, Central and Northeastern Tanzania during wet years, with significantly higher NDVI compared to drought years. Conversely, regions such as Uganda, Rwanda, Burundi, and parts of western and southern Tanzania exhibited lower NDVI during wet years than in drought years, thereby underscoring the existence of significant regional differences in vegetation responses to climatic conditions. The results of the correlation analysis indicated that there was a negative correlation between NDVI and SLHF, air temperature, and soil temperature, while positive correlations were observed between NDVI and SSHF, precipitation, and soil moisture. Furthermore, teleconnections with large-scale climate indices demonstrated modest correlations: Niño 3.4 (r = 0.33), DMI (r = 0.11), and AMO (r = 0.03). These findings emphasize the pivotal role of climatic and meteorological factors in influencing vegetation dynamics, offering insights for sustainable land management and climate adaptation strategies in East Africa.展开更多
In recent years, extreme high temperature events occurred more frequently in Northern Africa (NA) posing significant impacts on ecological systems and socioeconomic development. However, the physical origin of these e...In recent years, extreme high temperature events occurred more frequently in Northern Africa (NA) posing significant impacts on ecological systems and socioeconomic development. However, the physical origin of these extreme high temperatures remains unexplored. To address this issue, Empirical Orthogonal Function (EOF) analysis technics is employed to investigate the key physical factors influencing the spatial patterns of extreme high temperature days (EHDs) over NA. Three major modes of EHDs (EOF1, EOF2 and EOF3) accounting for 43%, 11% and 8% of the total variance were identified in this study. EOF1 features uniform distribution associated with positive geopotential heights and anticyclonic flows, while EOF2 is characterized by a meridional dipole pattern. Using reanalysis datasets, these modes are further linked to ocean – land – atmosphere interactions to reveal underlying physical mechanism. EOF1 is influenced by tropical and subtropical positive SSTA associated by mid tropospheric heights which triggers heat wave transport and subsidence. This mode is also influenced by weakening of west African monsoon system which suppresses moisture transport towards NA. EOF2 is influenced by combination of tropical Indian ocean and western Pacific wave trains leading subsidence over NA. EOF3 captures more the transient or regional scale influences on EHDs due to it weak association with large-scale teleconnections. Generally, this study classifies the factors influencing summer patterns of EHDs over NA as 1) tropical and subtropical SST warming, 2) decaying of Monsoon circulation, and 3) Strengthened upper-level subsidence. Gaining an understanding of these processes is essential for improving climate prediction and setting strategies for early warning and mitigation of the impacts from extreme heat events.展开更多
Africa’s Threatened Rhinos.Decimated by relentless poaching for their highly coveted horns,subjected to large-scale slaughter by“sports”hunters throughout the 19th and early 20th centuries,and squeezed by the stead...Africa’s Threatened Rhinos.Decimated by relentless poaching for their highly coveted horns,subjected to large-scale slaughter by“sports”hunters throughout the 19th and early 20th centuries,and squeezed by the steady loss of their natural habitats,both black and white rhinos have been pushed perilously close to extinction.展开更多
As an emerging industry catering to diverse needs across commercial,industrial,civil,and military fields,the low-altitude economy has the potential to transform industries such as logistics,transportation,tourism,heal...As an emerging industry catering to diverse needs across commercial,industrial,civil,and military fields,the low-altitude economy has the potential to transform industries such as logistics,transportation,tourism,health care,agriculture,and infrastructure.展开更多
The world in 2024 was far from peaceful.The conflict between Russia and Ukraine has persisted for over 1,000 days.Meanwhile,a new wave of violence in the Palestinian-Israeli conflict,ongoing for more than a year,spill...The world in 2024 was far from peaceful.The conflict between Russia and Ukraine has persisted for over 1,000 days.Meanwhile,a new wave of violence in the Palestinian-Israeli conflict,ongoing for more than a year,spilled over into Lebanon,Iran,and even Syria.Africa also faced new challenges to peace and security over the past year.Armed conflicts continued in various regions,particularly in the Horn of Africa,while terrorism and external interference exacerbated regional instability.These challenges made peace and security a crucial focus for African nations and an increasingly important aspect of China-Africa cooperation.展开更多
Humming factories,bustling ports,and shuttling merchants highlight the vibrancy of China-Africa economic and trade cooperation.Over the years,this partnership has grown significantly,optimising trade structures and fo...Humming factories,bustling ports,and shuttling merchants highlight the vibrancy of China-Africa economic and trade cooperation.Over the years,this partnership has grown significantly,optimising trade structures and fostering mutual development.This deepening collaboration is evident in China’s role as Africa’s largest bilateral trading partner for 15 consecutive years.During the first seven months of 2024,trade between China and African countries reached$167 billion,reflecting a 5.5-percent increase compared to the same period in 2023.According to the International Monetary Fund,approximately 20 percent of Africa’s exports now go to China,while 16 percent of its imports originate there.展开更多
As the 2025 G20 presidency,South Africa hosted the G20 Foreign Ministers’Meeting in Johannesburg on 20-21 February,which will convene foreign ministers of G20 members such as Chinese Foreign Minister Wang Yi.This is ...As the 2025 G20 presidency,South Africa hosted the G20 Foreign Ministers’Meeting in Johannesburg on 20-21 February,which will convene foreign ministers of G20 members such as Chinese Foreign Minister Wang Yi.This is an important event before the G20 Johannesburg Summit in November.展开更多
Home to over 30 percent of the world’s critical mineral reserves,Africa contributes just about 4 percent of global carbon emissions,and yet the region bears the brunt of the impacts of climate change due to its high ...Home to over 30 percent of the world’s critical mineral reserves,Africa contributes just about 4 percent of global carbon emissions,and yet the region bears the brunt of the impacts of climate change due to its high exposure,underdevelopment,weak economy,and limited financial resources for adaptation.展开更多
China is the largest developing country,and Africa is the continent with the highest concentration of developing countries.Similar historical experiences and common historical missions have long linked China and Afric...China is the largest developing country,and Africa is the continent with the highest concentration of developing countries.Similar historical experiences and common historical missions have long linked China and Africa so closely.From September 4 to 6,the 2024 Forum on China-Africa Cooperation(FOCAC)Summit will be held in Beijing.The theme this year is“Joining Hands to Promote Modernization and Build a High-Level China-Africa Community with a Shared Future”.Leaders of FOCAC’s African members will be invited to attend,and representatives from relevant African regional organizations and international organizations will participate in the related activities.展开更多
China and African countries are in different development stages,but they have the same mission of pursuing industrialisation.History shows that industrialisation is the inevitable path for economic development,as well...China and African countries are in different development stages,but they have the same mission of pursuing industrialisation.History shows that industrialisation is the inevitable path for economic development,as well as the key for African countries to realise inclusive and sustainable development,create employment,alleviate poverty and improve people’s livelihoods.展开更多
Climate change poses a serious long-term threat to biodiversity.To effectively reduce biodiversity loss,conservationists need to have a thorough understanding of the preferred habitats of species and the variables tha...Climate change poses a serious long-term threat to biodiversity.To effectively reduce biodiversity loss,conservationists need to have a thorough understanding of the preferred habitats of species and the variables that affect their distribution.Therefore,predicting the impact of climate change on speciesappropriate habitats may help mitigate the potential threats to biodiversity distribution.Xerophyta,a monocotyledonous genus of the family Velloziaceae is native to mainland Africa,Madagascar,and the Arabian Peninsula.The key drivers of Xerophyta habitat distribution and preference are unknown.Using 308 species occurrence data and eight environmental variables,the MaxEnt model was used to determine the potential distribution of six Xerophyta species in Africa under past,current and future climate change scenarios.The results showed that the models had a good predictive ability(Area Under the Curve and True Skill Statistics values for all SDMs were more than 0.902),indicating high accuracy in forecasting the potential geographic distribution of Xerophyta species.The main bioclimatic variables that impacted potential distributions of most Xerophyta species were mean temperature of the driest quarter(Bio9)and precipitation of the warmest quarter(Bio18).According to our models,tropical Africa has zones of moderate and high suitability for Xerophyta taxa,which is consistent with the majority of documented species localities.The habitat suitability of the existing range of the Xerophyta species varied based on the climate scenario,with most species experiencing a range loss greater than the range gain regardless of the climate scenario.The projected spatiotemporal patterns of Xerophyta species help guide recommendations for conservation efforts.展开更多
This study assesses the suitability of convolutional neural networks(CNNs) for downscaling precipitation over East Africa in the context of seasonal forecasting. To achieve this, we design a set of experiments that co...This study assesses the suitability of convolutional neural networks(CNNs) for downscaling precipitation over East Africa in the context of seasonal forecasting. To achieve this, we design a set of experiments that compare different CNN configurations and deployed the best-performing architecture to downscale one-month lead seasonal forecasts of June–July–August–September(JJAS) precipitation from the Nanjing University of Information Science and Technology Climate Forecast System version 1.0(NUIST-CFS1.0) for 1982–2020. We also perform hyper-parameter optimization and introduce predictors over a larger area to include information about the main large-scale circulations that drive precipitation over the East Africa region, which improves the downscaling results. Finally, we validate the raw model and downscaled forecasts in terms of both deterministic and probabilistic verification metrics, as well as their ability to reproduce the observed precipitation extreme and spell indicator indices. The results show that the CNN-based downscaling consistently improves the raw model forecasts, with lower bias and more accurate representations of the observed mean and extreme precipitation spatial patterns. Besides, CNN-based downscaling yields a much more accurate forecast of extreme and spell indicators and reduces the significant relative biases exhibited by the raw model predictions. Moreover, our results show that CNN-based downscaling yields better skill scores than the raw model forecasts over most portions of East Africa. The results demonstrate the potential usefulness of CNN in downscaling seasonal precipitation predictions over East Africa,particularly in providing improved forecast products which are essential for end users.展开更多
Based on the analysis of the fluid inclusion homogenization temperature and apatite fission track on the northern slope zone of the Bongor Basin in Chad,this paper studied the time and stages of hydrocarbon accumulati...Based on the analysis of the fluid inclusion homogenization temperature and apatite fission track on the northern slope zone of the Bongor Basin in Chad,this paper studied the time and stages of hydrocarbon accumulation in the study area.The results show that:(1)The brine inclusions of the samples from the Kubla and Prosopis formations in the Lower Cretaceous coexisting with the hydrocarbon generally present two sets of peak ranges of homogenization temperature,with the peak ranges of low temperature and high temperature being 75–105℃ and 115–135℃,respectively;(2)The samples from the Kubla and Prosopis formations have experienced five tectonic evolution stages,i.e.,rapid subsidence in the Early Cretaceous,tectonic inversion in the Late Cretaceous,small subsidence in the Paleogene,uplift at the turn of the Paleogene and Neogene,and subsidence since the Miocene,in which the denudation thickness of the Late Cretaceous and after the turn of the Paleogene and Neogene are~1.8 km and~0.5 km,respectively.The cumulative denudation thickness of the two periods is about 2.3 km;(3)Using the brine inclusion homogenization temperature coexisting with the hydrocarbon as the capture temperature of the hydrocarbon,and combining with the apatite fission track thermal history modeling,the result shows that the Kubla and Prosopis formations in the Lower Cretaceous on the northern slope of the Bongor Basin have the same hydrocarbon accumulation time and stages,both of which have undergone two stages of hydrocarbon charging at 80–95 Ma and 65–80 Ma.The first stage of charging corresponds to the initial migration of hydrocarbon at the end of the Early Cretaceous rapid sedimentation,while the second stage of charging is in the stage of intense tectonic inversion in the Late Cretaceous.展开更多
Objectives: More than a year after its introduction, COVID-19 vaccination coverage was low in the Togolese population and little data were available on its benefits for hospitalized patients. This study aimed to descr...Objectives: More than a year after its introduction, COVID-19 vaccination coverage was low in the Togolese population and little data were available on its benefits for hospitalized patients. This study aimed to describe the impact of COVID-19 vaccination on the prognosis of hospitalized patients. Methods: This was a retrospective cohort study of patients admitted to the Centre Hospitalier Régional Lomé Commune (Togo) between June 1, 2021 and May 31, 2022. Primary outcomes (admission to the intensive care unit and death) were presented with frequency and proportion. Mortality rates were presented by sociodemographic and clinical characteristics and compared by appropriate statistical tests. Factors associated with inpatient death were described by performing a Cox proportional hazard regression. Results: A total of 604 patients were hospitalized (50.0% women). The mean age was 54.03 ±17.1 years. Only 55 patients were fully vaccinated (9.1%). ICU admission was significantly more frequent in unvaccinated patients than in vaccinated ones (63.0% vs. 38.2%;p Conclusion: COVID-19 vaccination had a significant benefit for patients with COVID-19 infection in terms of reducing the risk of death. Based on real-world data from sub-Saharan Africa, this information can help optimize the benefit of COVID-19 vaccination by raising community awareness and increasing vaccine coverage while reducing hesitancy.展开更多
The recent discovery of large oil and gas fields in the deep-water of the Senegal Basin has drawn global attention.Despite this,several exploration wells in this area fail,which can be primarily contributed to a lack ...The recent discovery of large oil and gas fields in the deep-water of the Senegal Basin has drawn global attention.Despite this,several exploration wells in this area fail,which can be primarily contributed to a lack of understanding of the basin's structures and hydrocarbon accumulation conditions.This study examines these characteristics utilizing gravity,seismic and drilling data,and finally makes a comparison with the Cote d’Ivoire Basin,a typical transform margin basin in the South Atlantic.The results suggest that the Senegal Basin,influenced by multiple transform faults and a weak Paleozoic basement,experienced three evolutionary stages:rifting,transitional,and drifting.Each stage contributed to the development of distinct depositional sequences-syn-rift sequences,sag sequences,and continental margin sequences,respectively.The Triassic-Early Jurassic rifting stage predominantly formed continental deposits,like fluvial,lacustrine,and deltaic deposits,in the syn-rift sequences.The Middle-Late Jurassic transitional stage,influenced by transform faults,witnessed the formation of marginal ridges or submarine uplift zones.These zones,in conjunction with landward high terrains,formed a restricted environment promoting the development of source rocks in the sag sequences.During the drifting stage,three types of reservoirs,namely platform carbonate rocks,deltas,and slope-floor fans were formed.Notably,large-scale hydrocarbon reservoirs have been found in the deltas and the slope-floor fans both in the Senegal Basin and the Cote d’Ivoire Basin.The Upper Jurassic-Aptian platforms exhibit thick carbonate rocks and organic reefs on their edges,suggesting substantial potential for hydrocarbon exploration in the Senegal Basin.展开更多
Introduction: Seasonal Malaria Chemoprevention (SMC) aims at preventing malaria in children during the high transmission season. It has been recommended by the WHO since 2013 for children from the age of 3-59 months. ...Introduction: Seasonal Malaria Chemoprevention (SMC) aims at preventing malaria in children during the high transmission season. It has been recommended by the WHO since 2013 for children from the age of 3-59 months. However, despite the impact of this intervention, a peak in the prevalence and incidence of malaria is observed in children from the age of 5-9 years. The aim of this study is to determine from the current literature the feasibility, impact and cost-effectiveness of extending SMC to five cycles and to older children. Methods: A litterature search of PubMed/Medline, NCBI and Google scholar identified 1333 articles. After reading the titles and abstracts by two authors, 24 articles were selected and submitted for full reading. Random control studies on the extension of SMC, malaria, feasibility of SMC, impact of SMC and cost-effectiveness of SMC were selected. A total of 16 articles were included for the qualitative synthesis after excluding 8 studies. Results: Following the summary of the evidence, we conclude that the extension is feasible but will be confronted with the unavailability of older children. The intervention period coincides with field work. SMC is effective in reducing the prevalence and incidence of malaria and the parasite density in children. The financial cost of administering SMC is lower than that of treating a child suffering from malaria. Conclusion: After analysing the information, it was found that the majority of the African population supports the extension of the SMC to the number of cycles and the age group in order to alleviate the high mortality and morbidity rates among children due to malaria.展开更多
We examine Africa's vaccine manufacturing potential,spurred by the coronavirus disease 2019(COVID-19)pan-demic,while critically analyzing vaccine price inequities and procurement strategies during the pandemic,wit...We examine Africa's vaccine manufacturing potential,spurred by the coronavirus disease 2019(COVID-19)pan-demic,while critically analyzing vaccine price inequities and procurement strategies during the pandemic,with anticipation of future outbreaks.Although Africa consumes approximately 25%of the global vaccine supply,over 99%of these vaccines are produced outside the continent,primarily due to insufficient local investment.Vaccine procurement strategies have relied heavily on pooled procurement mechanisms and tiered-pricing mod-els,predominantly controlled by external organizations.Significant disparities in vaccine pricing have resulted in vaccine price inequities,with evidence suggesting price discrimination,where different prices are charged for the same vaccine across countries and regions.While vaccine prices are only one component of vaccination cam-paign costs,the inequitable pricing of vaccines poses serious challenges to fair access,especially in low-income countries.Given the inevitability of future pandemics and other outbreaks,the central question remains:Does Africa possess the capacity to strengthen its vaccine production infrastructure and reduce dependency on ex-ternal suppliers?Our review reveals that,with robust political commitment,enhanced investment in Research and Development,and leveraging the heterogeneous nature of the regional bloc,Africa has made strides toward establishing vaccine manufacturing hubs with the potential for substantial capacity expansion.Furthermore,we argue for a regional campaign based on the principles of the fair priority model as an ethical framework for vaccine procurement,which prioritizes need and ensures equitable distribution,thereby complementing existing pooled procurement arrangements in times of future pandemics.This paper concludes with two key recommen-dations based on lessons learned from the COvID-19 crisis and future preparedness.First,Africa must push for a transparent and equitable tiered-pricing structure to ensure affordability for all Second,intentional and sustained investment in R&D is critical to addressing systemic inequities in vaccine supply,not only for cOVID-19 but for future outbreaks and routine immunization programs.展开更多
Background: Cardiac rehabilitation represents a critical therapeutic strategy for patients suffering from chronic heart failure. The physical capacity of patients with heart failure, assessed using the exercise test a...Background: Cardiac rehabilitation represents a critical therapeutic strategy for patients suffering from chronic heart failure. The physical capacity of patients with heart failure, assessed using the exercise test and the 6-minute walk test, is the measure of the patient’s overall functional ability to perform physical activities and tolerate exercise loads. The objective of this study was to assess the impact of cardiac rehabilitation on patients’ physical capabilities and to conduct a thorough comparison of data obtained via exercise testing and the 6-minute walk test before and after the rehabilitation programme. Methods: This was a descriptive and analytical cross-sectional study, conducted from 1 February 2021 to 31 June 2022. Included were heart failure patients who had participated in an outpatient cardiovascular rehabilitation programme. The collected data included anamnestic, clinical, paraclinical data, and the 6-minute walk test. Informed consent was obtained. Data analysis, word processing, and charting were performed using Microsoft Word 2016, Excel 2013, and Sphinx version 5.1.0.2. Data analysis was performed using SPSS (Statistical Package for Social Sciences) version 24.0. Any difference less than 0.05 was considered statistically significant. Results: In a Senegalese study, heart failure patients undergoing rehabilitation in a cardiac unit represented 45.59% of all cases, with a prevalence rate of 3.21%. The average participant was 57.97 years old, with those aged 61 to 70 forming the largest group (35.5%). The study noted a male predominance (sex ratio of 2.1) and identified dyslipidaemia (80.6%) and sedentarism (71%), as prevalent cardiovascular risk factors. All participants initially suffered from NYHA stage 2 or 3 dyspnoea, yet 80.65% showed no symptoms following rehabilitation. Significant improvements were recorded in resting heart rate (from 79 to 67 bpm), and the 6-minute walk test distance (from 328 m to 470 m). Enhanced exercise tolerance and walking test outcomes were particularly notable in patients with LVEF ≥ 50%, women, non-obese individuals, those initially walking less than 300 m, achieving more than 3 METs, and non-smokers. Conclusion: The findings underscore the effectiveness of cardiovascular rehabilitation in improving symptoms, physical capability, and overall quality of life for heart failure patients in Senegal.展开更多
文摘It’s that time of the year again when we find ourselves reflecting on the year that was and the year ahead.On the African continent,many countries are still recovering from the aftershocks of the COVID-19 pandemic and are doing so amid a fraught geopolitical environment.These tensions have,to some extent,created hurdles in the path of Africa’s recovery.The African Development Bank has attributed the economic slowdown on the continent toastronomical inflation caused by soaring food andenergy prices. These issues have been aggravatedby the current geopolitical chaos and climatechange. Nevertheless, the continent is projectedto grow at a steady rate of 4.3 percent in 2025.This means that Africa will retain its positionas the fastest-growing region after Asia. This isdriven by several positive factors.
文摘We analysed nine simulations from dynamic downscaling to a horizontal resolution of approximately 25 km of three general circulation models (GCMs). These GCMs use three regional climate models (RCMs) that participated in the coordinated downscaling experiment (CORDEX-CORE). These simulations were compared to three datasets of reanalysis. The ERA5 for temperature at 2 metres and for precipitation, Climate Hazards Center InfraRed Precipitation with Stations (CHIRPS) and African Rainfall Climatology from the Famine Early Warning System (FEWS-ARC) were used. To give an overview of these nine model experiments, we presented and compared the results of the latter with the reanalysis taken into account for the period 1983 - 2005. The results indicated that the nine models correctly reproduced the temperature and rainfall in West Africa during the historical period. In the Guinean coast region, REMO-NorESM1 and RegCM4-MPI-MR models well simulated precipitation and temperature during the historical period. In the Savannah region, RegCM4-NorESM1, CCLM5-MPI-LR, REMO-NorESM1, CCLM5-NorESM1 and CCLM5-HadGEM2 model gave best result. In the Sahel region, the RegCM4-HadGEM2 model gave a good correlation. Using the Taylor diagram in the historical period, all CORDEX-CORE RCMs had a strong relationship with temperature.
文摘The interannual variability of Normalized Difference Vegetation Index (NDVI) over East Africa demonstrates the complex interactions between vegetation dynamics and climatic factors. This study, which spans the period from 1983 to 2022, makes use of data from NOAA, ERA5, and CRU. It employs a range of statistical techniques, including the calculation of standardized anomalies, significance testing, composites and correlation analyses. The results demonstrated an increase in NDVI over regions including Kenya, Central and Northeastern Tanzania during wet years, with significantly higher NDVI compared to drought years. Conversely, regions such as Uganda, Rwanda, Burundi, and parts of western and southern Tanzania exhibited lower NDVI during wet years than in drought years, thereby underscoring the existence of significant regional differences in vegetation responses to climatic conditions. The results of the correlation analysis indicated that there was a negative correlation between NDVI and SLHF, air temperature, and soil temperature, while positive correlations were observed between NDVI and SSHF, precipitation, and soil moisture. Furthermore, teleconnections with large-scale climate indices demonstrated modest correlations: Niño 3.4 (r = 0.33), DMI (r = 0.11), and AMO (r = 0.03). These findings emphasize the pivotal role of climatic and meteorological factors in influencing vegetation dynamics, offering insights for sustainable land management and climate adaptation strategies in East Africa.
文摘In recent years, extreme high temperature events occurred more frequently in Northern Africa (NA) posing significant impacts on ecological systems and socioeconomic development. However, the physical origin of these extreme high temperatures remains unexplored. To address this issue, Empirical Orthogonal Function (EOF) analysis technics is employed to investigate the key physical factors influencing the spatial patterns of extreme high temperature days (EHDs) over NA. Three major modes of EHDs (EOF1, EOF2 and EOF3) accounting for 43%, 11% and 8% of the total variance were identified in this study. EOF1 features uniform distribution associated with positive geopotential heights and anticyclonic flows, while EOF2 is characterized by a meridional dipole pattern. Using reanalysis datasets, these modes are further linked to ocean – land – atmosphere interactions to reveal underlying physical mechanism. EOF1 is influenced by tropical and subtropical positive SSTA associated by mid tropospheric heights which triggers heat wave transport and subsidence. This mode is also influenced by weakening of west African monsoon system which suppresses moisture transport towards NA. EOF2 is influenced by combination of tropical Indian ocean and western Pacific wave trains leading subsidence over NA. EOF3 captures more the transient or regional scale influences on EHDs due to it weak association with large-scale teleconnections. Generally, this study classifies the factors influencing summer patterns of EHDs over NA as 1) tropical and subtropical SST warming, 2) decaying of Monsoon circulation, and 3) Strengthened upper-level subsidence. Gaining an understanding of these processes is essential for improving climate prediction and setting strategies for early warning and mitigation of the impacts from extreme heat events.
文摘Africa’s Threatened Rhinos.Decimated by relentless poaching for their highly coveted horns,subjected to large-scale slaughter by“sports”hunters throughout the 19th and early 20th centuries,and squeezed by the steady loss of their natural habitats,both black and white rhinos have been pushed perilously close to extinction.
文摘As an emerging industry catering to diverse needs across commercial,industrial,civil,and military fields,the low-altitude economy has the potential to transform industries such as logistics,transportation,tourism,health care,agriculture,and infrastructure.
文摘The world in 2024 was far from peaceful.The conflict between Russia and Ukraine has persisted for over 1,000 days.Meanwhile,a new wave of violence in the Palestinian-Israeli conflict,ongoing for more than a year,spilled over into Lebanon,Iran,and even Syria.Africa also faced new challenges to peace and security over the past year.Armed conflicts continued in various regions,particularly in the Horn of Africa,while terrorism and external interference exacerbated regional instability.These challenges made peace and security a crucial focus for African nations and an increasingly important aspect of China-Africa cooperation.
文摘Humming factories,bustling ports,and shuttling merchants highlight the vibrancy of China-Africa economic and trade cooperation.Over the years,this partnership has grown significantly,optimising trade structures and fostering mutual development.This deepening collaboration is evident in China’s role as Africa’s largest bilateral trading partner for 15 consecutive years.During the first seven months of 2024,trade between China and African countries reached$167 billion,reflecting a 5.5-percent increase compared to the same period in 2023.According to the International Monetary Fund,approximately 20 percent of Africa’s exports now go to China,while 16 percent of its imports originate there.
文摘As the 2025 G20 presidency,South Africa hosted the G20 Foreign Ministers’Meeting in Johannesburg on 20-21 February,which will convene foreign ministers of G20 members such as Chinese Foreign Minister Wang Yi.This is an important event before the G20 Johannesburg Summit in November.
文摘Home to over 30 percent of the world’s critical mineral reserves,Africa contributes just about 4 percent of global carbon emissions,and yet the region bears the brunt of the impacts of climate change due to its high exposure,underdevelopment,weak economy,and limited financial resources for adaptation.
文摘China is the largest developing country,and Africa is the continent with the highest concentration of developing countries.Similar historical experiences and common historical missions have long linked China and Africa so closely.From September 4 to 6,the 2024 Forum on China-Africa Cooperation(FOCAC)Summit will be held in Beijing.The theme this year is“Joining Hands to Promote Modernization and Build a High-Level China-Africa Community with a Shared Future”.Leaders of FOCAC’s African members will be invited to attend,and representatives from relevant African regional organizations and international organizations will participate in the related activities.
文摘China and African countries are in different development stages,but they have the same mission of pursuing industrialisation.History shows that industrialisation is the inevitable path for economic development,as well as the key for African countries to realise inclusive and sustainable development,create employment,alleviate poverty and improve people’s livelihoods.
基金supported by grants from the International Partnership Program of Chinese Academy of Sciences (151853KYSB20190027)Sino-Africa Joint Research Center, CAS (SAJC202101)The ANSO Scholarship for Young Talents, PhD Fellowship Program University of Chinese Academy of Sciences, China
文摘Climate change poses a serious long-term threat to biodiversity.To effectively reduce biodiversity loss,conservationists need to have a thorough understanding of the preferred habitats of species and the variables that affect their distribution.Therefore,predicting the impact of climate change on speciesappropriate habitats may help mitigate the potential threats to biodiversity distribution.Xerophyta,a monocotyledonous genus of the family Velloziaceae is native to mainland Africa,Madagascar,and the Arabian Peninsula.The key drivers of Xerophyta habitat distribution and preference are unknown.Using 308 species occurrence data and eight environmental variables,the MaxEnt model was used to determine the potential distribution of six Xerophyta species in Africa under past,current and future climate change scenarios.The results showed that the models had a good predictive ability(Area Under the Curve and True Skill Statistics values for all SDMs were more than 0.902),indicating high accuracy in forecasting the potential geographic distribution of Xerophyta species.The main bioclimatic variables that impacted potential distributions of most Xerophyta species were mean temperature of the driest quarter(Bio9)and precipitation of the warmest quarter(Bio18).According to our models,tropical Africa has zones of moderate and high suitability for Xerophyta taxa,which is consistent with the majority of documented species localities.The habitat suitability of the existing range of the Xerophyta species varied based on the climate scenario,with most species experiencing a range loss greater than the range gain regardless of the climate scenario.The projected spatiotemporal patterns of Xerophyta species help guide recommendations for conservation efforts.
基金supported by the National Key Research and Development Program of China (Grant No.2020YFA0608000)the National Natural Science Foundation of China (Grant No. 42030605)the High-Performance Computing of Nanjing University of Information Science&Technology for their support of this work。
文摘This study assesses the suitability of convolutional neural networks(CNNs) for downscaling precipitation over East Africa in the context of seasonal forecasting. To achieve this, we design a set of experiments that compare different CNN configurations and deployed the best-performing architecture to downscale one-month lead seasonal forecasts of June–July–August–September(JJAS) precipitation from the Nanjing University of Information Science and Technology Climate Forecast System version 1.0(NUIST-CFS1.0) for 1982–2020. We also perform hyper-parameter optimization and introduce predictors over a larger area to include information about the main large-scale circulations that drive precipitation over the East Africa region, which improves the downscaling results. Finally, we validate the raw model and downscaled forecasts in terms of both deterministic and probabilistic verification metrics, as well as their ability to reproduce the observed precipitation extreme and spell indicator indices. The results show that the CNN-based downscaling consistently improves the raw model forecasts, with lower bias and more accurate representations of the observed mean and extreme precipitation spatial patterns. Besides, CNN-based downscaling yields a much more accurate forecast of extreme and spell indicators and reduces the significant relative biases exhibited by the raw model predictions. Moreover, our results show that CNN-based downscaling yields better skill scores than the raw model forecasts over most portions of East Africa. The results demonstrate the potential usefulness of CNN in downscaling seasonal precipitation predictions over East Africa,particularly in providing improved forecast products which are essential for end users.
基金Supported by the PetroChina Science and Technology Project(2023ZZ0703)National Natural Science Foundation of China(42072229,41102131).
文摘Based on the analysis of the fluid inclusion homogenization temperature and apatite fission track on the northern slope zone of the Bongor Basin in Chad,this paper studied the time and stages of hydrocarbon accumulation in the study area.The results show that:(1)The brine inclusions of the samples from the Kubla and Prosopis formations in the Lower Cretaceous coexisting with the hydrocarbon generally present two sets of peak ranges of homogenization temperature,with the peak ranges of low temperature and high temperature being 75–105℃ and 115–135℃,respectively;(2)The samples from the Kubla and Prosopis formations have experienced five tectonic evolution stages,i.e.,rapid subsidence in the Early Cretaceous,tectonic inversion in the Late Cretaceous,small subsidence in the Paleogene,uplift at the turn of the Paleogene and Neogene,and subsidence since the Miocene,in which the denudation thickness of the Late Cretaceous and after the turn of the Paleogene and Neogene are~1.8 km and~0.5 km,respectively.The cumulative denudation thickness of the two periods is about 2.3 km;(3)Using the brine inclusion homogenization temperature coexisting with the hydrocarbon as the capture temperature of the hydrocarbon,and combining with the apatite fission track thermal history modeling,the result shows that the Kubla and Prosopis formations in the Lower Cretaceous on the northern slope of the Bongor Basin have the same hydrocarbon accumulation time and stages,both of which have undergone two stages of hydrocarbon charging at 80–95 Ma and 65–80 Ma.The first stage of charging corresponds to the initial migration of hydrocarbon at the end of the Early Cretaceous rapid sedimentation,while the second stage of charging is in the stage of intense tectonic inversion in the Late Cretaceous.
文摘Objectives: More than a year after its introduction, COVID-19 vaccination coverage was low in the Togolese population and little data were available on its benefits for hospitalized patients. This study aimed to describe the impact of COVID-19 vaccination on the prognosis of hospitalized patients. Methods: This was a retrospective cohort study of patients admitted to the Centre Hospitalier Régional Lomé Commune (Togo) between June 1, 2021 and May 31, 2022. Primary outcomes (admission to the intensive care unit and death) were presented with frequency and proportion. Mortality rates were presented by sociodemographic and clinical characteristics and compared by appropriate statistical tests. Factors associated with inpatient death were described by performing a Cox proportional hazard regression. Results: A total of 604 patients were hospitalized (50.0% women). The mean age was 54.03 ±17.1 years. Only 55 patients were fully vaccinated (9.1%). ICU admission was significantly more frequent in unvaccinated patients than in vaccinated ones (63.0% vs. 38.2%;p Conclusion: COVID-19 vaccination had a significant benefit for patients with COVID-19 infection in terms of reducing the risk of death. Based on real-world data from sub-Saharan Africa, this information can help optimize the benefit of COVID-19 vaccination by raising community awareness and increasing vaccine coverage while reducing hesitancy.
基金funded by the projects of the SINOPEC Science&Technology Department(P21043-3,P23181)the Basic Prospective Research Projects of SINOPEC,China(P22214-2,P22214-1).
文摘The recent discovery of large oil and gas fields in the deep-water of the Senegal Basin has drawn global attention.Despite this,several exploration wells in this area fail,which can be primarily contributed to a lack of understanding of the basin's structures and hydrocarbon accumulation conditions.This study examines these characteristics utilizing gravity,seismic and drilling data,and finally makes a comparison with the Cote d’Ivoire Basin,a typical transform margin basin in the South Atlantic.The results suggest that the Senegal Basin,influenced by multiple transform faults and a weak Paleozoic basement,experienced three evolutionary stages:rifting,transitional,and drifting.Each stage contributed to the development of distinct depositional sequences-syn-rift sequences,sag sequences,and continental margin sequences,respectively.The Triassic-Early Jurassic rifting stage predominantly formed continental deposits,like fluvial,lacustrine,and deltaic deposits,in the syn-rift sequences.The Middle-Late Jurassic transitional stage,influenced by transform faults,witnessed the formation of marginal ridges or submarine uplift zones.These zones,in conjunction with landward high terrains,formed a restricted environment promoting the development of source rocks in the sag sequences.During the drifting stage,three types of reservoirs,namely platform carbonate rocks,deltas,and slope-floor fans were formed.Notably,large-scale hydrocarbon reservoirs have been found in the deltas and the slope-floor fans both in the Senegal Basin and the Cote d’Ivoire Basin.The Upper Jurassic-Aptian platforms exhibit thick carbonate rocks and organic reefs on their edges,suggesting substantial potential for hydrocarbon exploration in the Senegal Basin.
文摘Introduction: Seasonal Malaria Chemoprevention (SMC) aims at preventing malaria in children during the high transmission season. It has been recommended by the WHO since 2013 for children from the age of 3-59 months. However, despite the impact of this intervention, a peak in the prevalence and incidence of malaria is observed in children from the age of 5-9 years. The aim of this study is to determine from the current literature the feasibility, impact and cost-effectiveness of extending SMC to five cycles and to older children. Methods: A litterature search of PubMed/Medline, NCBI and Google scholar identified 1333 articles. After reading the titles and abstracts by two authors, 24 articles were selected and submitted for full reading. Random control studies on the extension of SMC, malaria, feasibility of SMC, impact of SMC and cost-effectiveness of SMC were selected. A total of 16 articles were included for the qualitative synthesis after excluding 8 studies. Results: Following the summary of the evidence, we conclude that the extension is feasible but will be confronted with the unavailability of older children. The intervention period coincides with field work. SMC is effective in reducing the prevalence and incidence of malaria and the parasite density in children. The financial cost of administering SMC is lower than that of treating a child suffering from malaria. Conclusion: After analysing the information, it was found that the majority of the African population supports the extension of the SMC to the number of cycles and the age group in order to alleviate the high mortality and morbidity rates among children due to malaria.
文摘We examine Africa's vaccine manufacturing potential,spurred by the coronavirus disease 2019(COVID-19)pan-demic,while critically analyzing vaccine price inequities and procurement strategies during the pandemic,with anticipation of future outbreaks.Although Africa consumes approximately 25%of the global vaccine supply,over 99%of these vaccines are produced outside the continent,primarily due to insufficient local investment.Vaccine procurement strategies have relied heavily on pooled procurement mechanisms and tiered-pricing mod-els,predominantly controlled by external organizations.Significant disparities in vaccine pricing have resulted in vaccine price inequities,with evidence suggesting price discrimination,where different prices are charged for the same vaccine across countries and regions.While vaccine prices are only one component of vaccination cam-paign costs,the inequitable pricing of vaccines poses serious challenges to fair access,especially in low-income countries.Given the inevitability of future pandemics and other outbreaks,the central question remains:Does Africa possess the capacity to strengthen its vaccine production infrastructure and reduce dependency on ex-ternal suppliers?Our review reveals that,with robust political commitment,enhanced investment in Research and Development,and leveraging the heterogeneous nature of the regional bloc,Africa has made strides toward establishing vaccine manufacturing hubs with the potential for substantial capacity expansion.Furthermore,we argue for a regional campaign based on the principles of the fair priority model as an ethical framework for vaccine procurement,which prioritizes need and ensures equitable distribution,thereby complementing existing pooled procurement arrangements in times of future pandemics.This paper concludes with two key recommen-dations based on lessons learned from the COvID-19 crisis and future preparedness.First,Africa must push for a transparent and equitable tiered-pricing structure to ensure affordability for all Second,intentional and sustained investment in R&D is critical to addressing systemic inequities in vaccine supply,not only for cOVID-19 but for future outbreaks and routine immunization programs.
文摘Background: Cardiac rehabilitation represents a critical therapeutic strategy for patients suffering from chronic heart failure. The physical capacity of patients with heart failure, assessed using the exercise test and the 6-minute walk test, is the measure of the patient’s overall functional ability to perform physical activities and tolerate exercise loads. The objective of this study was to assess the impact of cardiac rehabilitation on patients’ physical capabilities and to conduct a thorough comparison of data obtained via exercise testing and the 6-minute walk test before and after the rehabilitation programme. Methods: This was a descriptive and analytical cross-sectional study, conducted from 1 February 2021 to 31 June 2022. Included were heart failure patients who had participated in an outpatient cardiovascular rehabilitation programme. The collected data included anamnestic, clinical, paraclinical data, and the 6-minute walk test. Informed consent was obtained. Data analysis, word processing, and charting were performed using Microsoft Word 2016, Excel 2013, and Sphinx version 5.1.0.2. Data analysis was performed using SPSS (Statistical Package for Social Sciences) version 24.0. Any difference less than 0.05 was considered statistically significant. Results: In a Senegalese study, heart failure patients undergoing rehabilitation in a cardiac unit represented 45.59% of all cases, with a prevalence rate of 3.21%. The average participant was 57.97 years old, with those aged 61 to 70 forming the largest group (35.5%). The study noted a male predominance (sex ratio of 2.1) and identified dyslipidaemia (80.6%) and sedentarism (71%), as prevalent cardiovascular risk factors. All participants initially suffered from NYHA stage 2 or 3 dyspnoea, yet 80.65% showed no symptoms following rehabilitation. Significant improvements were recorded in resting heart rate (from 79 to 67 bpm), and the 6-minute walk test distance (from 328 m to 470 m). Enhanced exercise tolerance and walking test outcomes were particularly notable in patients with LVEF ≥ 50%, women, non-obese individuals, those initially walking less than 300 m, achieving more than 3 METs, and non-smokers. Conclusion: The findings underscore the effectiveness of cardiovascular rehabilitation in improving symptoms, physical capability, and overall quality of life for heart failure patients in Senegal.
