Purpose: Malaria continues to be a public health threat, especially in sub-Saharan Africa, including Uganda. While Batwa Indigenous People (IPs) face a higher burden of malaria, there is limited understanding of their...Purpose: Malaria continues to be a public health threat, especially in sub-Saharan Africa, including Uganda. While Batwa Indigenous People (IPs) face a higher burden of malaria, there is limited understanding of their malaria-lived experiences. We assessed and characterized malaria illness and accessing healthcare lived experiences of the Batwa in Kanungu district to inform contextually and culturally appropriate public health interventions. Methods: An exploratory qualitative study was conducted in 5 Batwa settlements where 5 Focus Group Discussions (n = 36) and 13 Key Informant Interviews (n = 13) were held. Data were collected using printed guides and voice recorders in April 2018. Transcripts from the data that captured the lived experiences of the symptoms, prevention, treatment and barriers to accessing formal healthcare services were applied to Atlas.ti a qualitative data analysis software and condensed into codes, categories, and themes. Results: Many Batwa have experienced malaria in their households, and they know its causes and risk factors, like not sleeping under insecticide-treated mosquito nets (ITNs), living near water bodies, prevention measures like the use of ITNs, and vector management. The lived experiences demonstrate malaria management by an Indigenous population in a rural setting and comprised detecting malaria symptoms, use of herbs as first line of treatment, buying medicines from drug shops, and village health teams (VHTs) treatment. For many Batwa accessing formal healthcare is normally a second option. Barriers for malaria treatment included: long distances to health facilities, geographically difficult terrain, economic constraints, irregular health outreaches, and stockouts of malaria medicines at health facilities. Conclusion: This study characterized Batwa’s malaria illness lived experiences and access to healthcare in rural remote settings. These experiences are essential in appreciating the ways in which Indigenous populations understand and manage common illnesses and how appropriate policies and interventions can be developed.展开更多
Background: Unsafe abortions are one of the leading causes of maternal mortality, especially in developing countries. In Cameroon, the maternal mortality rate remains high, and the scarcity of data on abortions leads ...Background: Unsafe abortions are one of the leading causes of maternal mortality, especially in developing countries. In Cameroon, the maternal mortality rate remains high, and the scarcity of data on abortions leads to a lack of solid evidence to advocate on the extent of the abortions related complications. Our objective was to evaluate the unsafe abortions related complications, and to assess the difficulties of accessing safe abortions in our setting. Methods: We carried out a meta-analytic and systematic review in the biomedical databases MEDLINE (Pubmed), Google Scholar and African Journal Online concerning unsafe abortions and/or difficulties in accessing safe abortions in Cameroon. The keywords used for the search are seen in table I. Selection of studies was simultaneously done by two authors. Data were extracted through a form designed on Google Form. We used a random-effect model for proportion estimation, and The I<sup>2</sup> and Q statistics to assess the extent of heterogeneity. Results: A total of 430 studies were identified, from which 28 were included and analysed. About 5% (95% CI: 3 - 7) of unsafe abortions leads to death. The contribution of unsafe abortions in maternal deaths was 23% (95% CI: 20 - 27). The rate of severe bleeding and/or anemia were 40% (95% CI: 18 - 63) and the rate of infection was 17% (95% CI: 7 - 28), dominated by pelvic infections, pelviperitonitis, severe sepsis, and septic shock. Case reports described uterine perforations, uterine rupture during the following pregnancy. Abortion was performed in the practitioner’s or patient’s home in 41.4% of cases, in a health center in 35.1% of cases, in a private clinic in 21.2% of cases, drugs selling places and in traditional healer clinics. The restriction of abortion laws, the stigma surrounding abortion and its consequences at any level of the society, lead to the underreporting of unsafe abortions and a deep reluctance to advocate for safe abortion services. Conclusion: The strengthening of awareness campaigns for provider behavior change communication, family planning, the de-stigmatization of abortions, the training of health personnel in post-abortion care, a multidisciplinary and multicentric action would contribute to the reduction in morbidity and mortality due to abortions.展开更多
The cooperation of multiple Unmanned Aerial Vehicles(UAVs) has become a promising scenario in Space-Air-Ground Integrated Networks(SAGINs) recently due to their widespread applications,where wireless communication is ...The cooperation of multiple Unmanned Aerial Vehicles(UAVs) has become a promising scenario in Space-Air-Ground Integrated Networks(SAGINs) recently due to their widespread applications,where wireless communication is a basic necessity and is normally categorized into control and nonpayload communication(CNPC) as well as payload communication. In this paper, we attempt to tackle two challenges of UAV communication respectively on establishing reliable CNPC links against the high mobility of UAVs as well as changeable communication conditions, and on offering dynamic resource optimization for Quality-of-Service(QoS) guaranteed payload communication with variable link connectivity. Firstly, we propose the concept of air controlling center(ACC), a virtual application equipped on the infrastructure in SAGINs, which can collect global information for estimating UAV trajectory and communication channels. We then introduce the knapsack problem for modelling resource optimization of UAV communication in order to provide optimal access points for both CNPC and payload communication. Meanwhile, using the air controlling information, predictive decision algorithm and handover strategy are introduced for the reliable connection with multiple access points. Simulation results demonstrate that our proposal ensures an approximate always-on reliable accessing of communication links and outperforms the existing methods against high mobility,sparse distribution, and physical obstacles.展开更多
Objective: Effective confirmation of pregnancy is a basic component of reproductive health services. It is a determinant for accessing antenatal care (ANC) if the pregnancy is wanted and abortion services if the pregn...Objective: Effective confirmation of pregnancy is a basic component of reproductive health services. It is a determinant for accessing antenatal care (ANC) if the pregnancy is wanted and abortion services if the pregnancy is unwanted. This study examined the effect of urine pregnancy testing in the timing of presentation for pregnancy care. Method: A cross-sectional study was conducted among 320 women presenting for antenatal care and 300 women presenting for abortion at private sector clinics in Western Nigeria. Results: The median age at first presentation was 20 weeks for ANC clients and 8 weeks for abortion clients. Obtaining urine pregnancy test of one’s accord was associated with a decrease in the gestational age at presentation of 3.7 weeks and 1.5 weeks for antenatal and abortion clients, respectively, independent of all other factors. Conclusion: Bearing in mind that the clinical benefit and public health impact of early presentation for antenatal and abortion services are unequivocal, strategies aimed at decreasing gestational age at presentation for pregnancy care should be given priority. “Fast-track” urine pregnancy testing services should be promoted in the private and public clinics in Nigeria.展开更多
This report presents the results of a study on Reproductive Health done in North Kivu in September 2009. It was conducted by HEAL Africa, in partnership with the Provisional Division of Health, and financed by the Uni...This report presents the results of a study on Reproductive Health done in North Kivu in September 2009. It was conducted by HEAL Africa, in partnership with the Provisional Division of Health, and financed by the University of Ottawa, Canada/CRDI with technical assistance from Western Cape University of South Africa. The study was conducted in the health zones of Birambizo and Kayna within the framework of the central office. The focus of the report is on one aspect of Reproductive Health—Low Risk Maternity. This study was conducted in rural areas given that Reproductive Health indicators are much weaker when compared with urban areas, according to EDS RDC, 2007 [1]. This study emphasizes the following points: General characteristics of the participants in the study, and the utilization and accessibility of maternity services in rural areas in conflict situations. The formula SPSS 12.0.1 was used to facilitate data analysis in the study. This study comes at a point in time when its relevance to HEAL Africa’s work will assist HEAL and its partners in determining the focus of interventions done in health zones in order to improve maternal and neonatal health. HEAL Africa firstly stepped into a Safe Motherhood pilot project in June 2006 for 9 months in the Masisi zone, then in 2007 in the Birambizo and Kayna health zones. In November 2007, HEAL expanded into Walikale and in October 2008, into Kirotshe, Binza, and Lubero. The intervention kit consists of reinforcing the capacity of existing health facilities, training traditional midwives who serve as a link between the community and the health structures, the provision of sanitary equipment, medical essentials and community mobilization was done through local leaders about health and reproduction, and organizing women of reproductive age in solidarity groups (SG) to generate maternity insurance. The community approach “Solidarity Groups for Maternity Insurance” constitutes the spine of HEAL Africa within the support it provides in Reproductive Health. The principal idea is to educate and train communities on how to use the MMR services that are available in their community, and to remove financial barriers to accessing health services. The 4 pillars that comprise the Safe Motherhood program are: family planning, prenatal care, safe assisted delivery and essential obstetric care. These four strategic measures are integral in assuring primary health care and equality for women. This study evaluates this approach, keeping in mind local strategies and their effects on improving the utilization and accessibility of reproductive health services.展开更多
Unsafe abortions constitute a public health problem. It is one of the causes of maternal mortality in the world and particularly in developing countries. Despite the progress made, maternal mortality remains high in C...Unsafe abortions constitute a public health problem. It is one of the causes of maternal mortality in the world and particularly in developing countries. Despite the progress made, maternal mortality remains high in Cameroon. The scarcity and disparity of data on abortions lead to a lack of strong evidence to advocate to decision-makers on the extent of the problems associated with abortions in Cameroon. Our objective is to estimate the rates of mortalities and complications related to unsafe abortions, as well as the difficulties of accessing safe abortions in Cameroon. We will carry out a systematic and meta-analytical review in the biomedical databases MEDLINE (Pubmed), Google Scholar and African Journal Online (AJOL) concerning unsafe abortions and/or difficulties in accessing safe abortions in Cameroon, without date or language restriction. Gray literature will be also consulted. Two authors will simultaneously select the studies and data extraction will be done using a Google Form. Proportions will be estimated on a random-effect model. The I<sup>2</sup> and Q statistics will be used to assess the extent of heterogeneity across the studies. The outcome of both the quantitative and qualitative parts of the study will be commented. Death and morbidity due to abortions can be prevented. A concerted multidisciplinary and multicentric action would be essential.展开更多
Background Children with rare diseases experience challenges at home and school and frequently require multi-disciplinary healthcare.We aimed to determine health service utilization by Australian children with rare di...Background Children with rare diseases experience challenges at home and school and frequently require multi-disciplinary healthcare.We aimed to determine health service utilization by Australian children with rare diseases and barriers to access-ing healthcare.Methods Parents completed an online survey on health professional and emergency department(ED)presentations,hospi-talization,and barriers to accessing services.Potential barriers to service access included residential location(city,regional,remote)and child health-related functioning,determined using a validated,parent-completed measure-of-function tool.Results Parents of 462 children with over 240 rare diseases completed the survey.Compared with the general population,these children were more likely to be hospitalized[odds ratio(OR)=17.25,95%confidence interval(CI)=15.50-19.20]and present to the ED(OR=4.15,95%CI=3.68-4.68)or a family physician(OR=4.14,95%CI=3.72-4.60).Child functional impairment was nil/mild(31%),moderate(48%)or severe(22%).Compared to children with nil/mild impair-ment,those with severe impairment were more likely to be hospitalized(OR=13.39,95%CI=7.65-23.44)and present to the ED(OR=11.16,95%CI=6.46-19.27).Most children(75%)lived in major cities,but children from regional(OR=2.78,95%CI=1.72-4.55)and remote areas(OR=9.09,95%CI=3.03-25.00)experienced significantly more barriers to healthcare access than children from major cities.Barriers included distance to travel,out-of-pocket costs,and lack of specialist medical and other health services.Conclusions Children with rare diseases,especially those with severe functional impairment have an enormous impact on health services,and better integrated multidisciplinary services with patient-centered care are needed.Access must be improved for children living in rural and remote settings.展开更多
Different efforts have been undertaken to customizing a security and privacy concern in clouddata access. Therefore, the security measures are reliable and the data access was verified as themajor problem in the cloud...Different efforts have been undertaken to customizing a security and privacy concern in clouddata access. Therefore, the security measures are reliable and the data access was verified as themajor problem in the cloud environment. To overcome this problem, we proposed an efficientdata access control using optimized homomorphic encryption (HE). Because users outsourcetheir sensitive information to cloud providers, data security and access control is one of themost difficult ongoing cloud computing research projects. Existing solutions that rely on cryptographictechnologies to address these security issues result in significant complexity for bothdata and cloud service providers. The experimental results show that the key generation is 7.6%decreased by HE and 14.14% less than the proposed method. The encryption time is 11.34% lessthan the optimized HE and 23.28% decreased by ECC. The decryption time is 13.18% and 24.07%when compared with HE and ECC respectively.展开更多
Over the past few decades,the Internet has rapidly diffused across China.The spread of the Internet has had a profound economic and social impact on Chinese rural areas.Existing research shows that Internet access sig...Over the past few decades,the Internet has rapidly diffused across China.The spread of the Internet has had a profound economic and social impact on Chinese rural areas.Existing research shows that Internet access significantly impacts agricultural production and improves smallholder farmers’income.Beyond these,the Internet can affect other dimensions of social welfare.However,research about the impact of Internet access on dietary quality in rural China remains scarce.This study utilizes multi-period panel data from Fixed Observation Point in rural China from 2009 to 2015 to estimate the impact of Internet access on dietary quality and food consumption of rural households and conducts a causal analysis.Regression models with time and household fixed effects allow robust estimation while reducing potential issues of unobserved heterogeneity.The estimates show that Internet access has significantly increased rural household dietary quality(measured by the Chinese Diet Balance Index).Further research finds that Internet access has increased the consumption of animal products,such as aquatic and dairy products.We also examine the underlying mechanisms.Internet access improves dietary quality and food consumption mainly through increasing household income and food expenditure.These results encourage the promotion of Internet access as a valuable tool for nutritional improvements,especially in rural areas.展开更多
Cometabolic degradation is currently an effective and extensively way to remove high molecular weight polycyclic aromatic hydrocarbons(HMW-PAHs).Unfortunately,due to low bio-accessibility and high biotoxicity,the come...Cometabolic degradation is currently an effective and extensively way to remove high molecular weight polycyclic aromatic hydrocarbons(HMW-PAHs).Unfortunately,due to low bio-accessibility and high biotoxicity,the cometabolic degradation rate of HMW-PAHs is limited.Glycine-β-cyclodextrin(GCD)was obtained through amino modification ofβ-cyclodextrin(BCD)and added to cometabolic system of phenanthrene(PHE)and pyrene(PYR)to assist PYR biodegradation.Results show that the addition of GCD(100 mg/L)effectively improved the removal rate of PYR(20 mg/L)by 42.3%.GCD appeared to increase the bio-accessibility and reduce the biotoxicity of PHE and PYR,and then promoted the growth of Pseudomonas stutzeri DJP1 and stimulated the elevation of dehydrogenase(DHA)and catechol 12 dioxygenase(C12O)activities.The phthalate metabolic pathway was accelerated,which improved the cometabolic degradation.This study provided a new reference for the cometabolic degradation of HMW-PAHs.展开更多
This paper investigates the low earth orbit(LEO)satellite-enabled coded compressed sensing(CCS)unsourced random access(URA)in orthogonal frequency division multiple access(OFDMA)framework,where a massive uniform plana...This paper investigates the low earth orbit(LEO)satellite-enabled coded compressed sensing(CCS)unsourced random access(URA)in orthogonal frequency division multiple access(OFDMA)framework,where a massive uniform planar array(UPA)is equipped on the satellite.In LEO satellite communications,unavoidable timing and frequency offsets cause phase shifts in the transmitted signals,substantially diminishing the decoding performance of current terrestrial CCS URA receiver.To cope with this issue,we expand the inner codebook with predefined timing and frequency offsets and formulate the inner decoding as a tractable compressed sensing(CS)problem.Additionally,we leverage the inherent sparsity of the UPA-equipped LEO satellite angular domain channels,thereby enabling the outer decoder to support more active devices.Furthermore,the outputs of the outer decoder are used to reduce the search space of the inner decoder,which cuts down the computational complexity and accelerates the convergence of the inner decoding.Simulation results verify the effectiveness of the proposed scheme.展开更多
As a basic technology at physical layer of mobile communications,non-orthogonal multiple access has been attracting wide attention across the academia and the industry.During the standardization of the fifth-generatio...As a basic technology at physical layer of mobile communications,non-orthogonal multiple access has been attracting wide attention across the academia and the industry.During the standardization of the fifth-generation(5G)of mobile communications,3GPP conducted preliminary study on non-orthogonal multiple access without reaching the consensus to standardize the technology.展开更多
In this paper,ambient IoT is used as a typical use case of massive connections for the sixth generation(6G)mobile communications where we derive the performance requirements to facilitate the evaluation of technical s...In this paper,ambient IoT is used as a typical use case of massive connections for the sixth generation(6G)mobile communications where we derive the performance requirements to facilitate the evaluation of technical solutions.A rather complete design of unsourced multiple access is proposed in which two key parts:a compressed sensing module for active user detection,and a sparse interleaver-division multiple access(SIDMA)module are simulated side by side on a same platform at balanced signal to noise ratio(SNR)operating points.With a proper combination of compressed sensing matrix,a convolutional encoder,receiver algorithms,the simulated performance results appear superior to the state-of-the-art benchmark,yet with relatively less complicated processing.展开更多
Owing to the ubiquity of wireless networks and the popularity of WiFi infrastructures,received signal strength(RSS)-based indoor localization systems have received much attention.The placement of access points(APs)sig...Owing to the ubiquity of wireless networks and the popularity of WiFi infrastructures,received signal strength(RSS)-based indoor localization systems have received much attention.The placement of access points(APs)significantly influences localization accuracy and network access.However,the indoor scenario and network access are not fully considered in previous AP placement optimization methods.This study proposes a practical scenario modelingaided AP placement optimization method for improving localization accuracy and network access.In order to reduce the gap between simulation-based and field measurement-based AP placement optimization methods,we introduce an indoor scenario modeling and Gaussian process-based RSS prediction method.After that,the localization and network access metrics are implemented in the multiple objective particle swarm optimization(MOPSO)solution,Pareto front criterion and virtual repulsion force are applied to determine the optimal AP placement.Finally,field experiments demonstrate the effectiveness of the proposed indoor scenario modeling method and RSS prediction model.A thorough comparison confirms the localization and network access improvement attributed to the proposed anchor placement method.展开更多
The Internet of Things(IoT)access controlmechanism may encounter security issues such as single point of failure and data tampering.To address these issues,a blockchain-based IoT reputation value attribute access cont...The Internet of Things(IoT)access controlmechanism may encounter security issues such as single point of failure and data tampering.To address these issues,a blockchain-based IoT reputation value attribute access control scheme is proposed.Firstly,writing the reputation value as an attribute into the access control policy,and then deploying the access control policy in the smart contract of the blockchain system can enable the system to provide more fine-grained access control;Secondly,storing a large amount of resources fromthe Internet of Things in Inter Planetary File System(IPFS)to improve system throughput;Finally,map resource access operations to qualification tokens to improve the performance of the access control system.Complete simulation experiments based on the Hyperledger Fabric platform.Fromthe simulation experimental results,it can be seen that the access control system can achieve more fine-grained and dynamic access control while maintaining high throughput and low time delay,providing sufficient reliability and security for access control of IoT devices.展开更多
Reducing the process variation is a significant concern for resistive random access memory(RRAM).Due to its ultrahigh integration density,RRAM arrays are prone to lithographic variation during the lithography process,...Reducing the process variation is a significant concern for resistive random access memory(RRAM).Due to its ultrahigh integration density,RRAM arrays are prone to lithographic variation during the lithography process,introducing electrical variation among different RRAM devices.In this work,an optical physical verification methodology for the RRAM array is developed,and the effects of different layout parameters on important electrical characteristics are systematically investigated.The results indicate that the RRAM devices can be categorized into three clusters according to their locations and lithography environments.The read resistance is more sensitive to the locations in the array(~30%)than SET/RESET voltage(<10%).The increase in the RRAM device length and the application of the optical proximity correction technique can help to reduce the variation to less than 10%,whereas it reduces RRAM read resistance by 4×,resulting in a higher power and area consumption.As such,we provide design guidelines to minimize the electrical variation of RRAM arrays due to the lithography process.展开更多
Massive machine type communication aims to support the connection of massive devices,which is still an important scenario in 6G.In this paper,a novel cluster-based massive access method is proposed for massive multipl...Massive machine type communication aims to support the connection of massive devices,which is still an important scenario in 6G.In this paper,a novel cluster-based massive access method is proposed for massive multiple input multiple output systems.By exploiting the angular domain characteristics,devices are separated into multiple clusters with a learned cluster-specific dictionary,which enhances the identification of active devices.For detected active devices whose data recovery fails,power domain nonorthogonal multiple access with successive interference cancellation is employed to recover their data via re-transmission.Simulation results show that the proposed scheme and algorithm achieve improved performance on active user detection and data recovery.展开更多
Big data resources are characterized by large scale, wide sources, and strong dynamics. Existing access controlmechanisms based on manual policy formulation by security experts suffer from drawbacks such as low policy...Big data resources are characterized by large scale, wide sources, and strong dynamics. Existing access controlmechanisms based on manual policy formulation by security experts suffer from drawbacks such as low policymanagement efficiency and difficulty in accurately describing the access control policy. To overcome theseproblems, this paper proposes a big data access control mechanism based on a two-layer permission decisionstructure. This mechanism extends the attribute-based access control (ABAC) model. Business attributes areintroduced in the ABAC model as business constraints between entities. The proposed mechanism implementsa two-layer permission decision structure composed of the inherent attributes of access control entities and thebusiness attributes, which constitute the general permission decision algorithm based on logical calculation andthe business permission decision algorithm based on a bi-directional long short-term memory (BiLSTM) neuralnetwork, respectively. The general permission decision algorithm is used to implement accurate policy decisions,while the business permission decision algorithm implements fuzzy decisions based on the business constraints.The BiLSTM neural network is used to calculate the similarity of the business attributes to realize intelligent,adaptive, and efficient access control permission decisions. Through the two-layer permission decision structure,the complex and diverse big data access control management requirements can be satisfied by considering thesecurity and availability of resources. Experimental results show that the proposed mechanism is effective andreliable. In summary, it can efficiently support the secure sharing of big data resources.展开更多
Transportation accessibility has been treated as an important means of reducing the urban-rural income disparity.However,only a few studies have examined the effects of different types of transportation accessibility ...Transportation accessibility has been treated as an important means of reducing the urban-rural income disparity.However,only a few studies have examined the effects of different types of transportation accessibility on urban-rural income disparity and their spatial heterogeneity.Based on data from 285 prefecture-level(and above)Chinese cities in 2000,2005,2010,2015,and 2020,this study uses spatial econometric models to examine how highway accessibility and railway accessibility influence the urban-rural income disparity and to identify their spatial heterogeneity.The result reveals that highway accessibility and railway accessibility have‘coreperiphery’ring-like circle structures.The urban-rural income disparity exhibits strong spatial clustering effects.Both highway accessibility and railway accessibility are negatively associated with urban-rural income disparity,and the former having a greater effect size.Moreover,there is a substitution effect between highway accessibility and railway accessibility in the whole sample.Furthermore,these associations differ in geographic regions.In the central region,highway accessibility is more important in reducing the urban-rural income disparity,but its effect is weakened with the increase of railway accessibility.In the western region,railway accessibility has a larger effect on narrowing the urban-rural income disparity,and this effect is strengthened by the increase of highway accessibility.We conclude that improving transportation accessibility is conducive to reducing the urban-rural income disparity but its effect is spatial heterogenetic.Highways and railways should be developed in a coordinated manner to promote an integrated transport network system.展开更多
文摘Purpose: Malaria continues to be a public health threat, especially in sub-Saharan Africa, including Uganda. While Batwa Indigenous People (IPs) face a higher burden of malaria, there is limited understanding of their malaria-lived experiences. We assessed and characterized malaria illness and accessing healthcare lived experiences of the Batwa in Kanungu district to inform contextually and culturally appropriate public health interventions. Methods: An exploratory qualitative study was conducted in 5 Batwa settlements where 5 Focus Group Discussions (n = 36) and 13 Key Informant Interviews (n = 13) were held. Data were collected using printed guides and voice recorders in April 2018. Transcripts from the data that captured the lived experiences of the symptoms, prevention, treatment and barriers to accessing formal healthcare services were applied to Atlas.ti a qualitative data analysis software and condensed into codes, categories, and themes. Results: Many Batwa have experienced malaria in their households, and they know its causes and risk factors, like not sleeping under insecticide-treated mosquito nets (ITNs), living near water bodies, prevention measures like the use of ITNs, and vector management. The lived experiences demonstrate malaria management by an Indigenous population in a rural setting and comprised detecting malaria symptoms, use of herbs as first line of treatment, buying medicines from drug shops, and village health teams (VHTs) treatment. For many Batwa accessing formal healthcare is normally a second option. Barriers for malaria treatment included: long distances to health facilities, geographically difficult terrain, economic constraints, irregular health outreaches, and stockouts of malaria medicines at health facilities. Conclusion: This study characterized Batwa’s malaria illness lived experiences and access to healthcare in rural remote settings. These experiences are essential in appreciating the ways in which Indigenous populations understand and manage common illnesses and how appropriate policies and interventions can be developed.
文摘Background: Unsafe abortions are one of the leading causes of maternal mortality, especially in developing countries. In Cameroon, the maternal mortality rate remains high, and the scarcity of data on abortions leads to a lack of solid evidence to advocate on the extent of the abortions related complications. Our objective was to evaluate the unsafe abortions related complications, and to assess the difficulties of accessing safe abortions in our setting. Methods: We carried out a meta-analytic and systematic review in the biomedical databases MEDLINE (Pubmed), Google Scholar and African Journal Online concerning unsafe abortions and/or difficulties in accessing safe abortions in Cameroon. The keywords used for the search are seen in table I. Selection of studies was simultaneously done by two authors. Data were extracted through a form designed on Google Form. We used a random-effect model for proportion estimation, and The I<sup>2</sup> and Q statistics to assess the extent of heterogeneity. Results: A total of 430 studies were identified, from which 28 were included and analysed. About 5% (95% CI: 3 - 7) of unsafe abortions leads to death. The contribution of unsafe abortions in maternal deaths was 23% (95% CI: 20 - 27). The rate of severe bleeding and/or anemia were 40% (95% CI: 18 - 63) and the rate of infection was 17% (95% CI: 7 - 28), dominated by pelvic infections, pelviperitonitis, severe sepsis, and septic shock. Case reports described uterine perforations, uterine rupture during the following pregnancy. Abortion was performed in the practitioner’s or patient’s home in 41.4% of cases, in a health center in 35.1% of cases, in a private clinic in 21.2% of cases, drugs selling places and in traditional healer clinics. The restriction of abortion laws, the stigma surrounding abortion and its consequences at any level of the society, lead to the underreporting of unsafe abortions and a deep reluctance to advocate for safe abortion services. Conclusion: The strengthening of awareness campaigns for provider behavior change communication, family planning, the de-stigmatization of abortions, the training of health personnel in post-abortion care, a multidisciplinary and multicentric action would contribute to the reduction in morbidity and mortality due to abortions.
基金supported by the the National Key Research and Development Program of China under No. 2019YFB1803200National Natural Science Foundation of China under Grants 61620106001。
文摘The cooperation of multiple Unmanned Aerial Vehicles(UAVs) has become a promising scenario in Space-Air-Ground Integrated Networks(SAGINs) recently due to their widespread applications,where wireless communication is a basic necessity and is normally categorized into control and nonpayload communication(CNPC) as well as payload communication. In this paper, we attempt to tackle two challenges of UAV communication respectively on establishing reliable CNPC links against the high mobility of UAVs as well as changeable communication conditions, and on offering dynamic resource optimization for Quality-of-Service(QoS) guaranteed payload communication with variable link connectivity. Firstly, we propose the concept of air controlling center(ACC), a virtual application equipped on the infrastructure in SAGINs, which can collect global information for estimating UAV trajectory and communication channels. We then introduce the knapsack problem for modelling resource optimization of UAV communication in order to provide optimal access points for both CNPC and payload communication. Meanwhile, using the air controlling information, predictive decision algorithm and handover strategy are introduced for the reliable connection with multiple access points. Simulation results demonstrate that our proposal ensures an approximate always-on reliable accessing of communication links and outperforms the existing methods against high mobility,sparse distribution, and physical obstacles.
文摘Objective: Effective confirmation of pregnancy is a basic component of reproductive health services. It is a determinant for accessing antenatal care (ANC) if the pregnancy is wanted and abortion services if the pregnancy is unwanted. This study examined the effect of urine pregnancy testing in the timing of presentation for pregnancy care. Method: A cross-sectional study was conducted among 320 women presenting for antenatal care and 300 women presenting for abortion at private sector clinics in Western Nigeria. Results: The median age at first presentation was 20 weeks for ANC clients and 8 weeks for abortion clients. Obtaining urine pregnancy test of one’s accord was associated with a decrease in the gestational age at presentation of 3.7 weeks and 1.5 weeks for antenatal and abortion clients, respectively, independent of all other factors. Conclusion: Bearing in mind that the clinical benefit and public health impact of early presentation for antenatal and abortion services are unequivocal, strategies aimed at decreasing gestational age at presentation for pregnancy care should be given priority. “Fast-track” urine pregnancy testing services should be promoted in the private and public clinics in Nigeria.
文摘This report presents the results of a study on Reproductive Health done in North Kivu in September 2009. It was conducted by HEAL Africa, in partnership with the Provisional Division of Health, and financed by the University of Ottawa, Canada/CRDI with technical assistance from Western Cape University of South Africa. The study was conducted in the health zones of Birambizo and Kayna within the framework of the central office. The focus of the report is on one aspect of Reproductive Health—Low Risk Maternity. This study was conducted in rural areas given that Reproductive Health indicators are much weaker when compared with urban areas, according to EDS RDC, 2007 [1]. This study emphasizes the following points: General characteristics of the participants in the study, and the utilization and accessibility of maternity services in rural areas in conflict situations. The formula SPSS 12.0.1 was used to facilitate data analysis in the study. This study comes at a point in time when its relevance to HEAL Africa’s work will assist HEAL and its partners in determining the focus of interventions done in health zones in order to improve maternal and neonatal health. HEAL Africa firstly stepped into a Safe Motherhood pilot project in June 2006 for 9 months in the Masisi zone, then in 2007 in the Birambizo and Kayna health zones. In November 2007, HEAL expanded into Walikale and in October 2008, into Kirotshe, Binza, and Lubero. The intervention kit consists of reinforcing the capacity of existing health facilities, training traditional midwives who serve as a link between the community and the health structures, the provision of sanitary equipment, medical essentials and community mobilization was done through local leaders about health and reproduction, and organizing women of reproductive age in solidarity groups (SG) to generate maternity insurance. The community approach “Solidarity Groups for Maternity Insurance” constitutes the spine of HEAL Africa within the support it provides in Reproductive Health. The principal idea is to educate and train communities on how to use the MMR services that are available in their community, and to remove financial barriers to accessing health services. The 4 pillars that comprise the Safe Motherhood program are: family planning, prenatal care, safe assisted delivery and essential obstetric care. These four strategic measures are integral in assuring primary health care and equality for women. This study evaluates this approach, keeping in mind local strategies and their effects on improving the utilization and accessibility of reproductive health services.
文摘Unsafe abortions constitute a public health problem. It is one of the causes of maternal mortality in the world and particularly in developing countries. Despite the progress made, maternal mortality remains high in Cameroon. The scarcity and disparity of data on abortions lead to a lack of strong evidence to advocate to decision-makers on the extent of the problems associated with abortions in Cameroon. Our objective is to estimate the rates of mortalities and complications related to unsafe abortions, as well as the difficulties of accessing safe abortions in Cameroon. We will carry out a systematic and meta-analytical review in the biomedical databases MEDLINE (Pubmed), Google Scholar and African Journal Online (AJOL) concerning unsafe abortions and/or difficulties in accessing safe abortions in Cameroon, without date or language restriction. Gray literature will be also consulted. Two authors will simultaneously select the studies and data extraction will be done using a Google Form. Proportions will be estimated on a random-effect model. The I<sup>2</sup> and Q statistics will be used to assess the extent of heterogeneity across the studies. The outcome of both the quantitative and qualitative parts of the study will be commented. Death and morbidity due to abortions can be prevented. A concerted multidisciplinary and multicentric action would be essential.
基金an Australian Research Council Linkage Project grant scheme(No.LP110200277)The funding sources had no role in the study design+5 种基金in the collection,analysis and interpretation of datain the writing of the reportand in the decision to submit the paper for publication.During the period of the research,ZY held a Fellowship from the Sydney Medical School Foundation and LH was funded by a National Health and Medical Research Council of Australia Senior Research Fellowship(No.1117105)EJE was supported by a National Health and Medical Research Council of Australia Practitioner Fellowship(No.1021480)a Medical Research Futures Fund Next Generation Fellowship(No.1135959)CJ's Chair in Genomic Medicine is supported by The Royal Children's Hospital Foundation.
文摘Background Children with rare diseases experience challenges at home and school and frequently require multi-disciplinary healthcare.We aimed to determine health service utilization by Australian children with rare diseases and barriers to access-ing healthcare.Methods Parents completed an online survey on health professional and emergency department(ED)presentations,hospi-talization,and barriers to accessing services.Potential barriers to service access included residential location(city,regional,remote)and child health-related functioning,determined using a validated,parent-completed measure-of-function tool.Results Parents of 462 children with over 240 rare diseases completed the survey.Compared with the general population,these children were more likely to be hospitalized[odds ratio(OR)=17.25,95%confidence interval(CI)=15.50-19.20]and present to the ED(OR=4.15,95%CI=3.68-4.68)or a family physician(OR=4.14,95%CI=3.72-4.60).Child functional impairment was nil/mild(31%),moderate(48%)or severe(22%).Compared to children with nil/mild impair-ment,those with severe impairment were more likely to be hospitalized(OR=13.39,95%CI=7.65-23.44)and present to the ED(OR=11.16,95%CI=6.46-19.27).Most children(75%)lived in major cities,but children from regional(OR=2.78,95%CI=1.72-4.55)and remote areas(OR=9.09,95%CI=3.03-25.00)experienced significantly more barriers to healthcare access than children from major cities.Barriers included distance to travel,out-of-pocket costs,and lack of specialist medical and other health services.Conclusions Children with rare diseases,especially those with severe functional impairment have an enormous impact on health services,and better integrated multidisciplinary services with patient-centered care are needed.Access must be improved for children living in rural and remote settings.
文摘Different efforts have been undertaken to customizing a security and privacy concern in clouddata access. Therefore, the security measures are reliable and the data access was verified as themajor problem in the cloud environment. To overcome this problem, we proposed an efficientdata access control using optimized homomorphic encryption (HE). Because users outsourcetheir sensitive information to cloud providers, data security and access control is one of themost difficult ongoing cloud computing research projects. Existing solutions that rely on cryptographictechnologies to address these security issues result in significant complexity for bothdata and cloud service providers. The experimental results show that the key generation is 7.6%decreased by HE and 14.14% less than the proposed method. The encryption time is 11.34% lessthan the optimized HE and 23.28% decreased by ECC. The decryption time is 13.18% and 24.07%when compared with HE and ECC respectively.
基金This study was supported in part by the National Natural Science Foundation of China(71973136 and 72061147002)the 2115 Talent Development Program of China Agricultural University.
文摘Over the past few decades,the Internet has rapidly diffused across China.The spread of the Internet has had a profound economic and social impact on Chinese rural areas.Existing research shows that Internet access significantly impacts agricultural production and improves smallholder farmers’income.Beyond these,the Internet can affect other dimensions of social welfare.However,research about the impact of Internet access on dietary quality in rural China remains scarce.This study utilizes multi-period panel data from Fixed Observation Point in rural China from 2009 to 2015 to estimate the impact of Internet access on dietary quality and food consumption of rural households and conducts a causal analysis.Regression models with time and household fixed effects allow robust estimation while reducing potential issues of unobserved heterogeneity.The estimates show that Internet access has significantly increased rural household dietary quality(measured by the Chinese Diet Balance Index).Further research finds that Internet access has increased the consumption of animal products,such as aquatic and dairy products.We also examine the underlying mechanisms.Internet access improves dietary quality and food consumption mainly through increasing household income and food expenditure.These results encourage the promotion of Internet access as a valuable tool for nutritional improvements,especially in rural areas.
基金Supported by the National Natural Science Foundation of China(No.51979255)。
文摘Cometabolic degradation is currently an effective and extensively way to remove high molecular weight polycyclic aromatic hydrocarbons(HMW-PAHs).Unfortunately,due to low bio-accessibility and high biotoxicity,the cometabolic degradation rate of HMW-PAHs is limited.Glycine-β-cyclodextrin(GCD)was obtained through amino modification ofβ-cyclodextrin(BCD)and added to cometabolic system of phenanthrene(PHE)and pyrene(PYR)to assist PYR biodegradation.Results show that the addition of GCD(100 mg/L)effectively improved the removal rate of PYR(20 mg/L)by 42.3%.GCD appeared to increase the bio-accessibility and reduce the biotoxicity of PHE and PYR,and then promoted the growth of Pseudomonas stutzeri DJP1 and stimulated the elevation of dehydrogenase(DHA)and catechol 12 dioxygenase(C12O)activities.The phthalate metabolic pathway was accelerated,which improved the cometabolic degradation.This study provided a new reference for the cometabolic degradation of HMW-PAHs.
基金supported by the National Key R&D Program of China under Grant 2023YFB2904703the National Natural Science Foundation of China under Grant 62341110,62371122 and 62322104+1 种基金the Jiangsu Province Basic Research Project under Grant BK20192002the Fundamental Research Funds for the Central Universities under Grant 2242022k30005 and 2242023K5003。
文摘This paper investigates the low earth orbit(LEO)satellite-enabled coded compressed sensing(CCS)unsourced random access(URA)in orthogonal frequency division multiple access(OFDMA)framework,where a massive uniform planar array(UPA)is equipped on the satellite.In LEO satellite communications,unavoidable timing and frequency offsets cause phase shifts in the transmitted signals,substantially diminishing the decoding performance of current terrestrial CCS URA receiver.To cope with this issue,we expand the inner codebook with predefined timing and frequency offsets and formulate the inner decoding as a tractable compressed sensing(CS)problem.Additionally,we leverage the inherent sparsity of the UPA-equipped LEO satellite angular domain channels,thereby enabling the outer decoder to support more active devices.Furthermore,the outputs of the outer decoder are used to reduce the search space of the inner decoder,which cuts down the computational complexity and accelerates the convergence of the inner decoding.Simulation results verify the effectiveness of the proposed scheme.
文摘As a basic technology at physical layer of mobile communications,non-orthogonal multiple access has been attracting wide attention across the academia and the industry.During the standardization of the fifth-generation(5G)of mobile communications,3GPP conducted preliminary study on non-orthogonal multiple access without reaching the consensus to standardize the technology.
文摘In this paper,ambient IoT is used as a typical use case of massive connections for the sixth generation(6G)mobile communications where we derive the performance requirements to facilitate the evaluation of technical solutions.A rather complete design of unsourced multiple access is proposed in which two key parts:a compressed sensing module for active user detection,and a sparse interleaver-division multiple access(SIDMA)module are simulated side by side on a same platform at balanced signal to noise ratio(SNR)operating points.With a proper combination of compressed sensing matrix,a convolutional encoder,receiver algorithms,the simulated performance results appear superior to the state-of-the-art benchmark,yet with relatively less complicated processing.
文摘Owing to the ubiquity of wireless networks and the popularity of WiFi infrastructures,received signal strength(RSS)-based indoor localization systems have received much attention.The placement of access points(APs)significantly influences localization accuracy and network access.However,the indoor scenario and network access are not fully considered in previous AP placement optimization methods.This study proposes a practical scenario modelingaided AP placement optimization method for improving localization accuracy and network access.In order to reduce the gap between simulation-based and field measurement-based AP placement optimization methods,we introduce an indoor scenario modeling and Gaussian process-based RSS prediction method.After that,the localization and network access metrics are implemented in the multiple objective particle swarm optimization(MOPSO)solution,Pareto front criterion and virtual repulsion force are applied to determine the optimal AP placement.Finally,field experiments demonstrate the effectiveness of the proposed indoor scenario modeling method and RSS prediction model.A thorough comparison confirms the localization and network access improvement attributed to the proposed anchor placement method.
文摘The Internet of Things(IoT)access controlmechanism may encounter security issues such as single point of failure and data tampering.To address these issues,a blockchain-based IoT reputation value attribute access control scheme is proposed.Firstly,writing the reputation value as an attribute into the access control policy,and then deploying the access control policy in the smart contract of the blockchain system can enable the system to provide more fine-grained access control;Secondly,storing a large amount of resources fromthe Internet of Things in Inter Planetary File System(IPFS)to improve system throughput;Finally,map resource access operations to qualification tokens to improve the performance of the access control system.Complete simulation experiments based on the Hyperledger Fabric platform.Fromthe simulation experimental results,it can be seen that the access control system can achieve more fine-grained and dynamic access control while maintaining high throughput and low time delay,providing sufficient reliability and security for access control of IoT devices.
基金supported in part by the Open Fund of State Key Laboratory of Integrated Chips and Systems,Fudan Universityin part by the National Science Foundation of China under Grant No.62304133 and No.62350610271.
文摘Reducing the process variation is a significant concern for resistive random access memory(RRAM).Due to its ultrahigh integration density,RRAM arrays are prone to lithographic variation during the lithography process,introducing electrical variation among different RRAM devices.In this work,an optical physical verification methodology for the RRAM array is developed,and the effects of different layout parameters on important electrical characteristics are systematically investigated.The results indicate that the RRAM devices can be categorized into three clusters according to their locations and lithography environments.The read resistance is more sensitive to the locations in the array(~30%)than SET/RESET voltage(<10%).The increase in the RRAM device length and the application of the optical proximity correction technique can help to reduce the variation to less than 10%,whereas it reduces RRAM read resistance by 4×,resulting in a higher power and area consumption.As such,we provide design guidelines to minimize the electrical variation of RRAM arrays due to the lithography process.
基金supported by Natural Science Foundation of China(62122012,62221001)the Beijing Natural Science Foundation(L202019,L211012)the Fundamental Research Funds for the Central Universities(2022JBQY004)。
文摘Massive machine type communication aims to support the connection of massive devices,which is still an important scenario in 6G.In this paper,a novel cluster-based massive access method is proposed for massive multiple input multiple output systems.By exploiting the angular domain characteristics,devices are separated into multiple clusters with a learned cluster-specific dictionary,which enhances the identification of active devices.For detected active devices whose data recovery fails,power domain nonorthogonal multiple access with successive interference cancellation is employed to recover their data via re-transmission.Simulation results show that the proposed scheme and algorithm achieve improved performance on active user detection and data recovery.
基金Key Research and Development and Promotion Program of Henan Province(No.222102210069)Zhongyuan Science and Technology Innovation Leading Talent Project(224200510003)National Natural Science Foundation of China(No.62102449).
文摘Big data resources are characterized by large scale, wide sources, and strong dynamics. Existing access controlmechanisms based on manual policy formulation by security experts suffer from drawbacks such as low policymanagement efficiency and difficulty in accurately describing the access control policy. To overcome theseproblems, this paper proposes a big data access control mechanism based on a two-layer permission decisionstructure. This mechanism extends the attribute-based access control (ABAC) model. Business attributes areintroduced in the ABAC model as business constraints between entities. The proposed mechanism implementsa two-layer permission decision structure composed of the inherent attributes of access control entities and thebusiness attributes, which constitute the general permission decision algorithm based on logical calculation andthe business permission decision algorithm based on a bi-directional long short-term memory (BiLSTM) neuralnetwork, respectively. The general permission decision algorithm is used to implement accurate policy decisions,while the business permission decision algorithm implements fuzzy decisions based on the business constraints.The BiLSTM neural network is used to calculate the similarity of the business attributes to realize intelligent,adaptive, and efficient access control permission decisions. Through the two-layer permission decision structure,the complex and diverse big data access control management requirements can be satisfied by considering thesecurity and availability of resources. Experimental results show that the proposed mechanism is effective andreliable. In summary, it can efficiently support the secure sharing of big data resources.
基金Under the auspices of National Natural Science Foundation of China(No.42371214,42101184)Chenguang Program of Shanghai Education Development Foundation and Shanghai Municipal Education Commission(No.22CGA27)Funded Projects for the Academic Leaders and Academic Backbone,Shaanxi Normal University(No.18QNGG013)。
文摘Transportation accessibility has been treated as an important means of reducing the urban-rural income disparity.However,only a few studies have examined the effects of different types of transportation accessibility on urban-rural income disparity and their spatial heterogeneity.Based on data from 285 prefecture-level(and above)Chinese cities in 2000,2005,2010,2015,and 2020,this study uses spatial econometric models to examine how highway accessibility and railway accessibility influence the urban-rural income disparity and to identify their spatial heterogeneity.The result reveals that highway accessibility and railway accessibility have‘coreperiphery’ring-like circle structures.The urban-rural income disparity exhibits strong spatial clustering effects.Both highway accessibility and railway accessibility are negatively associated with urban-rural income disparity,and the former having a greater effect size.Moreover,there is a substitution effect between highway accessibility and railway accessibility in the whole sample.Furthermore,these associations differ in geographic regions.In the central region,highway accessibility is more important in reducing the urban-rural income disparity,but its effect is weakened with the increase of railway accessibility.In the western region,railway accessibility has a larger effect on narrowing the urban-rural income disparity,and this effect is strengthened by the increase of highway accessibility.We conclude that improving transportation accessibility is conducive to reducing the urban-rural income disparity but its effect is spatial heterogenetic.Highways and railways should be developed in a coordinated manner to promote an integrated transport network system.