Households in western Ethiopia are experiencing food insecurity driven by the effects of climate change.Hence,there is an opportunity to lessen the consequences of climate change by adopting climate-smart agriculture(...Households in western Ethiopia are experiencing food insecurity driven by the effects of climate change.Hence,there is an opportunity to lessen the consequences of climate change by adopting climate-smart agriculture(CSA).The study involved 385 households from western Ethiopia during the 2023–2024 production period.Specifically,we examined the variables that affect adoption decisions and investigated how the combined adoption of CSA practices affects maize yield.The multinomial endogenous switching regression(MESR)model was used to analyze these factors.The results showed that the adoption of CSA practices is positively impacted by age,gender,farm size,and education,but the distances from the household residence to market and plot have a negative impact.Adopters of CSA practices achieved a greater average yield per hectare than the non-adopters.Specifically,agroforestry,crop diversification,and adjusted planting dates all considerably increased maize yield,with gains of 0.21,0.70,and 0.52 t/hm^(2),respectively,compared to non-adoption.The implementation of combined CSA practices,rather than a single CSA practice,is a great way to mitigate the negative impacts of climate change.Therefore,we recommend ensuring adequate funding,providing incentives,facilitating technical assistance,and fostering community involvement when implementing combined CSA practices.This information is essential for reducing the negative consequences of climate change and developing successful adaptation strategies.展开更多
Carbon emission reductions through reducing deforestation and forest degradation or REDD+ scheme of the United Nations Framework Convention on Climate Change could not be achieved without understanding the drivers of ...Carbon emission reductions through reducing deforestation and forest degradation or REDD+ scheme of the United Nations Framework Convention on Climate Change could not be achieved without understanding the drivers of deforestation and forest degradation. Until recently, only a handful of study has focused on such drivers. Cambodia experienced rapid deforestation and forest degradation despite growing international interests in protecting forests for carbon revenue generation. This paper was designed to assess livelihood of forest-dependent community and drivers of deforestation and forest degradation in Cambodia. Quantitative and qualitative methods were used to collect socio-economic data from 42 households living in Phnom Tbeng forest, where annual deforestation rate was about 2.4% between 2004 and 2009. Our results suggest that local people depend on forests for income generation, subsistence use and social identity. About 90% of the respondents believed that deforestation was resulted from illegal logging, slush and burn agricultural practices, land clearing for large plantation, land encroachment, firewood extraction, charcoal production and forest fire. As the population has increased rapidly and almost 100% of local people depend on fuelwood for cooking, fuelwood collection will continue to cause deforestation and forest degradation unless alternative sources of affordable energy are provided. Appropriate policy interventions should be proposed to reduce the drivers obtained in this study because if drivers cannot be reduced, it is not possible to reduce deforestation and forest degradation, and related carbon emissions.展开更多
Marginalized groups,affected by the stigma of the label,have low intra-individual self-efficacy,lack external support in social life,and are often excluded in the economic,political and social relations,which is not c...Marginalized groups,affected by the stigma of the label,have low intra-individual self-efficacy,lack external support in social life,and are often excluded in the economic,political and social relations,which is not conducive to social justice and stability. In the perspective of empowerment theory,the marginalized groups need to be integrated into the society on individual,interpersonal,and political levels. On the individual empowerment level,self-efficacy is to be enhanced in the marginalized groups to promote their self-acceptance;on the interpersonal empowerment level,social resources for the marginalized groups are to be expanded through self-help groups so as to build an extensive social support network; on the political empowerment level,it is advocated to improve the relevant legislation and policy support. Social workers and various social parties should work together to create a good environment for the social integration of marginalized groups.展开更多
Farmer-pastoralist conflicts represent a significant challenge for rural communities and the Tanzanian government.The study objectives were to(i)determine existing forms of conflicts and(ii)identify drivers underlying...Farmer-pastoralist conflicts represent a significant challenge for rural communities and the Tanzanian government.The study objectives were to(i)determine existing forms of conflicts and(ii)identify drivers underlying resource use conflicts.The manuscript is based on a study that adopted a cross-sectional research design whereby data were collected from 373 randomly selected respondents from Kilosa and Kiteto districts,Tanzania,while primary data were collected through interviews,observations and focus group discussions,secondary data were gathered from government reports and newspapers.Quantitative data were analysed using the Statistical Package for the Social Science(SPSS)version 20.0.Descriptive statistical analysis was carried out for quantitative data.Factor analysis was used to extract component factors on drivers and forms of conflicts,whereas content analysis was used to analyse the qualitative data.Generally,study results show that there were three main forms of conflict namely farmers versus pastoralists over village boundaries;farmers versus pastoralists over livestock routes and farmers versus farmers over the land.In addition,four main drivers underlying resource use conflicts were identified namely crop damage by livestock;inefficiency of government officials in taking action to diffuse conflicts;excessively large herds of cattle and corruption.It is therefore recommended that pastoralists should be provided with essential services such as water in order to minimize movement of their livestock herds from their designated villages to other areas in search of water.This would,in the long run,minimise crop damage which has been a major source of conflict.In addition,proper land use planning is recommended to minimize resource use conflicts.展开更多
The role played by Payments for ecosystem services (PES) in promoting land use interventions is increasingly being recognized as an important instrument for changing land use management worldwide. Despite the increase...The role played by Payments for ecosystem services (PES) in promoting land use interventions is increasingly being recognized as an important instrument for changing land use management worldwide. Despite the increase, adoption of land use interventions promoted by PES and factors influencing it are not well understood. This study was carried out to assess the adoption of land use interventions promoted by PES scheme four years after its implementation in the Uluguru Mountains, Tanzania. The specific objectives of this study were to assess the adoption and factors that influenced it. The study employed questionnaire survey method to collect data from 219 households selected randomly. Focus group discussions and key informant interviews were also conducted to complement information obtained through questionnaire surveys. Descriptive and inferential statistical analyses were employed. Binary logistic regression was used to analyse quantitative data obtained, while content analysis was applied to qualitative data. Results revealed that during the project implementation, 40% of the households did not adopt any of the promoted interventions. Unexpectedly, four years after the project ended, every household sampled had adopted the interventions. Households headed by younger heads and those with land ownership, households which received PES incentives and lived for a long time in the same area and those with more labour force and access to extension services were found to have adopted more interventions (p ≤ 0.05). Thus, the study concludes that socioeconomic characteristics, agricultural extension services and incentives initially provided to farmers are key factors influencing the adoption of land use interventions. Therefore, it is recommended to the government that it should support farmers to get land tenure and to provide them with more incentives to improve their farms through adopting technologies.展开更多
Climate change and human activities are increasingly linked with the extinction of species globally. In semi-arid regions, these pressures threaten the natural distribution and ecology of species. The threat that the ...Climate change and human activities are increasingly linked with the extinction of species globally. In semi-arid regions, these pressures threaten the natural distribution and ecology of species. The threat that the shea butter tree (<em>Vitellaria paradoxa</em> subsp. <em>nilotica</em>) faces from human activity is well researched yet the sensitivity of its distribution to climate change remains barely known. We set out to assess the potential distribution of <em>Vitellaria</em> under different climate change scenarios using a MaxEnt. A current distribution model was first developed using only biophysical variables of soil type, temperature, precipitation, land use type, and elevation. This model was then projected onto two global warming scenarios (RCP 4.5 & RCP 8.5) for 2050 and 2070 using multi-model averages (BCC-CSM, CSM4, and MIROC5) derived from three general circulation models. Reductions are seen in distribution area across the landscape with soil type being the most important variable. These results draw useful implications for conservation of <em>Vitellaria</em> in that they show how it is vulnerable is to a changing climate as its natural range is mostly reduced. Since climate change is important in the distribution of the shea butter tree, the areas with highest suitability in this study can be used in establishing the Shea butter tree sustainable use zones/area within the Kidepo Critical Landscape (KCL), Uganda.展开更多
The COVID-19 pandemic has devastated global tourism and recovery is proceeding very slowly.For many countries,tourism served as a major economic sector,so investigating how to recover is essential.As China was the lar...The COVID-19 pandemic has devastated global tourism and recovery is proceeding very slowly.For many countries,tourism served as a major economic sector,so investigating how to recover is essential.As China was the largest source of outbound travelers before the outbreak,study of the factors influencing Chinese intentions to travel overseas in the post-COVID era is revealing.In Apr.2022,among seven provinces(or cities)with the most outbound tourists from 2019 to 2021,2450 individuals responded to a questionnaire on daily mobility,tourism experiences,and the shifts due to the pandemic.Light gradient boosting machine(LightGBM),a robust ensemble learning method,was adopted to quantify and visualize the impact of explanatory factors on outbound travel intention.In addition,the Optuna mechanism and Shapley additive explanation(SHAP)instruments were employed for tuning hyperparameters and interpreting results,respectively.Findings suggest neither one-day nor multi-day tours have resumed to pre-COVID levels.Higher frequency of multi-day tours with further destinations,less car utilization in daily shopping trips,and moderate pandemic restrictions can boost the intention to travel abroad.The concerns and desires of different age groups for overseas travel need different responses.This study reveals the factors affecting Chinese outbound travel intentions and provides suggestions for the recovery of tourism in the post-COVID period.展开更多
The management of rural sewage faces significant challenges due to the dispersed settlements and inadequate infrastructure characteristics of rural areas.One sustainable management solution is to use constructed wetla...The management of rural sewage faces significant challenges due to the dispersed settlements and inadequate infrastructure characteristics of rural areas.One sustainable management solution is to use constructed wetlands(CWs);however,traditional systems that rely on specific functional plants incur large maintenance costs.This study investigates an innovative approach that integrates native plants(Aster subulatus and Pterodactylus sp.)with functional plants(Arundo donax)in a horizontal subsurface CW(HSCW)to establish a self-sustaining symbiotic system that does not require human intervention.Over 365 days,the HSCW met stringent discharge standards by achieving mean removal efficiencies of 35.05%for chemical oxygen demand(COD_(Cr)),48.92%for ammonium nitrogen(NH^(+)_(4)-N),40.57%for total nitrogen(TN),and 27.61%for total phosphorus(TP).Microbial analysis identified Proteobacteria(34%),Actinobacteria(26%),and Bacteroidota(12%)as the dominant phyla,with rhizosphere communities influenced by plant-specific exudates and seasonal variations.Key nitrogen metabolism genes(nirB,nirD,nrfH)and genes coding for phosphorus-related enzymes(ppk,phoD)demonstrated seasonal adaptability driven by temperature fluctuations and plant-microbe interactions.Metagenomic sequencing revealed synergistic pathways,including nitrification-denitrification,dissimilatory nitrate reduction to ammonium(DNRA),and polyphosphate synthesis,which contributed to pollutant removal.Native plant polyculture enhanced microbial diversity and stability and reduced reliance on artificial maintenance.These findings demonstrate that leveraging natural plant symbiosis in CWs enhances ecological and economic sustainability by promoting microbial resilience and self-regulating nutrient cycling.Overall,CWs offer a viable strategy for decentralized sewage treatment in rural locations or any areas characterized by scattered settlements and poor infrastructure.展开更多
The record speed at which Chinese scientists identified severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)and shared its genomic sequence with the world,has greatly facilitated the development of coronavirus ...The record speed at which Chinese scientists identified severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)and shared its genomic sequence with the world,has greatly facilitated the development of coronavirus disease(COVID-19)diagnostics,drugs,and vaccines.It is unprecedented in pandemic control history to develop a dozen successful vaccines in the first year and to immunize over half of the global population in the second year,due to the efforts of the scientific community,biopharmaceutical industry,and regulatory agencies worldwide.The challenges are both great and multidimensional due to the rapid emergence of virus variants and waning of vaccine immunity.Vaccination strategies need to adapt to these challenges to keep population immunity above the herd immunity threshold,by increasing vaccine coverage,especially for older adults and young people,and providing timely booster doses with homologous or heterologous vaccine boosts.Further research should be undertaken to develop more effective vaccines against SARS-CoV-2 variants and to understand the best prime-boost vaccine combinations and immunization strategies to provide sufficient and sustainable immune protection against COVID-19.展开更多
The Build Back Better World(B3W) initiative launched by the U.S. and its allies at the Group of Seven(G7) Summit in Cornwall, Britain, in June has grabbed recent headlines. According to the White House, B3W is a value...The Build Back Better World(B3W) initiative launched by the U.S. and its allies at the Group of Seven(G7) Summit in Cornwall, Britain, in June has grabbed recent headlines. According to the White House, B3W is a values-driven, high-standard, and transparent global infrastructure development plan zooming in on four areas: climate, health and health security, digital technology, and gender equity and equality.展开更多
Federated Learning(FL)has recently attracted a lot of attention due to its ability to train a machine learning model using data from multiple clients without divulging their privacy.However,the training data across cl...Federated Learning(FL)has recently attracted a lot of attention due to its ability to train a machine learning model using data from multiple clients without divulging their privacy.However,the training data across clients can be very heterogeneous in terms of quality,amount,occurrences of specific features,etc.In this paper,we demonstrate how the server can observe data heterogeneity by mining gradient trajectories that the clients compute from a two-dimensional mapping of high-dimensional gradients computed by each client from its bottom layer.Based on these ideas,we propose a new clustered federated learning with gradient trajectory method,called CFLGT,which dynamically clusters clients together based on the gradient trajectories.We analyze CFLGT both theoretically and experimentally to show that it overcomes several drawbacks of mainstream Clustered Federated Learning(CFL)methods and outperforms other baselines.展开更多
基金Jimma University and Wollega University in Ethiopia for their formal support and help。
文摘Households in western Ethiopia are experiencing food insecurity driven by the effects of climate change.Hence,there is an opportunity to lessen the consequences of climate change by adopting climate-smart agriculture(CSA).The study involved 385 households from western Ethiopia during the 2023–2024 production period.Specifically,we examined the variables that affect adoption decisions and investigated how the combined adoption of CSA practices affects maize yield.The multinomial endogenous switching regression(MESR)model was used to analyze these factors.The results showed that the adoption of CSA practices is positively impacted by age,gender,farm size,and education,but the distances from the household residence to market and plot have a negative impact.Adopters of CSA practices achieved a greater average yield per hectare than the non-adopters.Specifically,agroforestry,crop diversification,and adjusted planting dates all considerably increased maize yield,with gains of 0.21,0.70,and 0.52 t/hm^(2),respectively,compared to non-adoption.The implementation of combined CSA practices,rather than a single CSA practice,is a great way to mitigate the negative impacts of climate change.Therefore,we recommend ensuring adequate funding,providing incentives,facilitating technical assistance,and fostering community involvement when implementing combined CSA practices.This information is essential for reducing the negative consequences of climate change and developing successful adaptation strategies.
文摘Carbon emission reductions through reducing deforestation and forest degradation or REDD+ scheme of the United Nations Framework Convention on Climate Change could not be achieved without understanding the drivers of deforestation and forest degradation. Until recently, only a handful of study has focused on such drivers. Cambodia experienced rapid deforestation and forest degradation despite growing international interests in protecting forests for carbon revenue generation. This paper was designed to assess livelihood of forest-dependent community and drivers of deforestation and forest degradation in Cambodia. Quantitative and qualitative methods were used to collect socio-economic data from 42 households living in Phnom Tbeng forest, where annual deforestation rate was about 2.4% between 2004 and 2009. Our results suggest that local people depend on forests for income generation, subsistence use and social identity. About 90% of the respondents believed that deforestation was resulted from illegal logging, slush and burn agricultural practices, land clearing for large plantation, land encroachment, firewood extraction, charcoal production and forest fire. As the population has increased rapidly and almost 100% of local people depend on fuelwood for cooking, fuelwood collection will continue to cause deforestation and forest degradation unless alternative sources of affordable energy are provided. Appropriate policy interventions should be proposed to reduce the drivers obtained in this study because if drivers cannot be reduced, it is not possible to reduce deforestation and forest degradation, and related carbon emissions.
基金The Ministry of Education of Humanities and Social Sciences Project,“Disempower and Empower:the Social Integration of Psychopaths”(12YJC840013)The Ministry of Education of Humanities and Social Sciences Project,“Stigma and Stigma Control of AIDS Patients”(11YJC840055)
文摘Marginalized groups,affected by the stigma of the label,have low intra-individual self-efficacy,lack external support in social life,and are often excluded in the economic,political and social relations,which is not conducive to social justice and stability. In the perspective of empowerment theory,the marginalized groups need to be integrated into the society on individual,interpersonal,and political levels. On the individual empowerment level,self-efficacy is to be enhanced in the marginalized groups to promote their self-acceptance;on the interpersonal empowerment level,social resources for the marginalized groups are to be expanded through self-help groups so as to build an extensive social support network; on the political empowerment level,it is advocated to improve the relevant legislation and policy support. Social workers and various social parties should work together to create a good environment for the social integration of marginalized groups.
文摘Farmer-pastoralist conflicts represent a significant challenge for rural communities and the Tanzanian government.The study objectives were to(i)determine existing forms of conflicts and(ii)identify drivers underlying resource use conflicts.The manuscript is based on a study that adopted a cross-sectional research design whereby data were collected from 373 randomly selected respondents from Kilosa and Kiteto districts,Tanzania,while primary data were collected through interviews,observations and focus group discussions,secondary data were gathered from government reports and newspapers.Quantitative data were analysed using the Statistical Package for the Social Science(SPSS)version 20.0.Descriptive statistical analysis was carried out for quantitative data.Factor analysis was used to extract component factors on drivers and forms of conflicts,whereas content analysis was used to analyse the qualitative data.Generally,study results show that there were three main forms of conflict namely farmers versus pastoralists over village boundaries;farmers versus pastoralists over livestock routes and farmers versus farmers over the land.In addition,four main drivers underlying resource use conflicts were identified namely crop damage by livestock;inefficiency of government officials in taking action to diffuse conflicts;excessively large herds of cattle and corruption.It is therefore recommended that pastoralists should be provided with essential services such as water in order to minimize movement of their livestock herds from their designated villages to other areas in search of water.This would,in the long run,minimise crop damage which has been a major source of conflict.In addition,proper land use planning is recommended to minimize resource use conflicts.
文摘The role played by Payments for ecosystem services (PES) in promoting land use interventions is increasingly being recognized as an important instrument for changing land use management worldwide. Despite the increase, adoption of land use interventions promoted by PES and factors influencing it are not well understood. This study was carried out to assess the adoption of land use interventions promoted by PES scheme four years after its implementation in the Uluguru Mountains, Tanzania. The specific objectives of this study were to assess the adoption and factors that influenced it. The study employed questionnaire survey method to collect data from 219 households selected randomly. Focus group discussions and key informant interviews were also conducted to complement information obtained through questionnaire surveys. Descriptive and inferential statistical analyses were employed. Binary logistic regression was used to analyse quantitative data obtained, while content analysis was applied to qualitative data. Results revealed that during the project implementation, 40% of the households did not adopt any of the promoted interventions. Unexpectedly, four years after the project ended, every household sampled had adopted the interventions. Households headed by younger heads and those with land ownership, households which received PES incentives and lived for a long time in the same area and those with more labour force and access to extension services were found to have adopted more interventions (p ≤ 0.05). Thus, the study concludes that socioeconomic characteristics, agricultural extension services and incentives initially provided to farmers are key factors influencing the adoption of land use interventions. Therefore, it is recommended to the government that it should support farmers to get land tenure and to provide them with more incentives to improve their farms through adopting technologies.
文摘Climate change and human activities are increasingly linked with the extinction of species globally. In semi-arid regions, these pressures threaten the natural distribution and ecology of species. The threat that the shea butter tree (<em>Vitellaria paradoxa</em> subsp. <em>nilotica</em>) faces from human activity is well researched yet the sensitivity of its distribution to climate change remains barely known. We set out to assess the potential distribution of <em>Vitellaria</em> under different climate change scenarios using a MaxEnt. A current distribution model was first developed using only biophysical variables of soil type, temperature, precipitation, land use type, and elevation. This model was then projected onto two global warming scenarios (RCP 4.5 & RCP 8.5) for 2050 and 2070 using multi-model averages (BCC-CSM, CSM4, and MIROC5) derived from three general circulation models. Reductions are seen in distribution area across the landscape with soil type being the most important variable. These results draw useful implications for conservation of <em>Vitellaria</em> in that they show how it is vulnerable is to a changing climate as its natural range is mostly reduced. Since climate change is important in the distribution of the shea butter tree, the areas with highest suitability in this study can be used in establishing the Shea butter tree sustainable use zones/area within the Kidepo Critical Landscape (KCL), Uganda.
基金the National Natural Science Foundation of China(No.52131202)the Natural Science Foundation of Zhejiang Province(No.Y21E080079)the Center for Balance Architecture,Zhejiang University,China.
文摘The COVID-19 pandemic has devastated global tourism and recovery is proceeding very slowly.For many countries,tourism served as a major economic sector,so investigating how to recover is essential.As China was the largest source of outbound travelers before the outbreak,study of the factors influencing Chinese intentions to travel overseas in the post-COVID era is revealing.In Apr.2022,among seven provinces(or cities)with the most outbound tourists from 2019 to 2021,2450 individuals responded to a questionnaire on daily mobility,tourism experiences,and the shifts due to the pandemic.Light gradient boosting machine(LightGBM),a robust ensemble learning method,was adopted to quantify and visualize the impact of explanatory factors on outbound travel intention.In addition,the Optuna mechanism and Shapley additive explanation(SHAP)instruments were employed for tuning hyperparameters and interpreting results,respectively.Findings suggest neither one-day nor multi-day tours have resumed to pre-COVID levels.Higher frequency of multi-day tours with further destinations,less car utilization in daily shopping trips,and moderate pandemic restrictions can boost the intention to travel abroad.The concerns and desires of different age groups for overseas travel need different responses.This study reveals the factors affecting Chinese outbound travel intentions and provides suggestions for the recovery of tourism in the post-COVID period.
基金supported by Jing-Jin-Ji Regional Integrated Environmental Improvement-National Science and Tech-nology Major Project(2025ZD1205400,2025ZD1205403)the Central Guidance Local Science and Technology Development Fund Project(2024ZY0130)+2 种基金Key R&D Program of Zhunger Banner(2024YF-07)National Natu2026ral Science Foundation of China(51838013),National Key R&D Program of China(2020YFD1100500)the Project of Inner Mongolia“Prairie Talents”Engineering Innovation Entrepreneurship Talent Team,and the Inno-vation Team of the Inner Mongolia Academy of Science and Technology(CXTD2023-01-016).
文摘The management of rural sewage faces significant challenges due to the dispersed settlements and inadequate infrastructure characteristics of rural areas.One sustainable management solution is to use constructed wetlands(CWs);however,traditional systems that rely on specific functional plants incur large maintenance costs.This study investigates an innovative approach that integrates native plants(Aster subulatus and Pterodactylus sp.)with functional plants(Arundo donax)in a horizontal subsurface CW(HSCW)to establish a self-sustaining symbiotic system that does not require human intervention.Over 365 days,the HSCW met stringent discharge standards by achieving mean removal efficiencies of 35.05%for chemical oxygen demand(COD_(Cr)),48.92%for ammonium nitrogen(NH^(+)_(4)-N),40.57%for total nitrogen(TN),and 27.61%for total phosphorus(TP).Microbial analysis identified Proteobacteria(34%),Actinobacteria(26%),and Bacteroidota(12%)as the dominant phyla,with rhizosphere communities influenced by plant-specific exudates and seasonal variations.Key nitrogen metabolism genes(nirB,nirD,nrfH)and genes coding for phosphorus-related enzymes(ppk,phoD)demonstrated seasonal adaptability driven by temperature fluctuations and plant-microbe interactions.Metagenomic sequencing revealed synergistic pathways,including nitrification-denitrification,dissimilatory nitrate reduction to ammonium(DNRA),and polyphosphate synthesis,which contributed to pollutant removal.Native plant polyculture enhanced microbial diversity and stability and reduced reliance on artificial maintenance.These findings demonstrate that leveraging natural plant symbiosis in CWs enhances ecological and economic sustainability by promoting microbial resilience and self-regulating nutrient cycling.Overall,CWs offer a viable strategy for decentralized sewage treatment in rural locations or any areas characterized by scattered settlements and poor infrastructure.
基金This work was supported by the National Natural Science Foundation of China(No.U20A20362).
文摘The record speed at which Chinese scientists identified severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)and shared its genomic sequence with the world,has greatly facilitated the development of coronavirus disease(COVID-19)diagnostics,drugs,and vaccines.It is unprecedented in pandemic control history to develop a dozen successful vaccines in the first year and to immunize over half of the global population in the second year,due to the efforts of the scientific community,biopharmaceutical industry,and regulatory agencies worldwide.The challenges are both great and multidimensional due to the rapid emergence of virus variants and waning of vaccine immunity.Vaccination strategies need to adapt to these challenges to keep population immunity above the herd immunity threshold,by increasing vaccine coverage,especially for older adults and young people,and providing timely booster doses with homologous or heterologous vaccine boosts.Further research should be undertaken to develop more effective vaccines against SARS-CoV-2 variants and to understand the best prime-boost vaccine combinations and immunization strategies to provide sufficient and sustainable immune protection against COVID-19.
文摘The Build Back Better World(B3W) initiative launched by the U.S. and its allies at the Group of Seven(G7) Summit in Cornwall, Britain, in June has grabbed recent headlines. According to the White House, B3W is a values-driven, high-standard, and transparent global infrastructure development plan zooming in on four areas: climate, health and health security, digital technology, and gender equity and equality.
基金supported by the National Natural Science Foundation of China(No.62072485)the Guangdong Basic and Applied Basic Research Foundation(No.2022A1515011294).
文摘Federated Learning(FL)has recently attracted a lot of attention due to its ability to train a machine learning model using data from multiple clients without divulging their privacy.However,the training data across clients can be very heterogeneous in terms of quality,amount,occurrences of specific features,etc.In this paper,we demonstrate how the server can observe data heterogeneity by mining gradient trajectories that the clients compute from a two-dimensional mapping of high-dimensional gradients computed by each client from its bottom layer.Based on these ideas,we propose a new clustered federated learning with gradient trajectory method,called CFLGT,which dynamically clusters clients together based on the gradient trajectories.We analyze CFLGT both theoretically and experimentally to show that it overcomes several drawbacks of mainstream Clustered Federated Learning(CFL)methods and outperforms other baselines.
