16 research outputs found
Exploring Agri-Food Import Dependency of Burundi: A Gravity Model Approach
The upward movement of agricultural and food imports has been a central issue in Burundi, since it hampers the growth of agricultural sector and poses a major disincentive to farmersā ability to produce more and cope with the risks associated with food production.Ā This paper aims to find critical factors that determine the surge of agri-food imports observed during post civil war (2000-2010). A gravity model was estimated from the data collected during the period of 2000-2010. The random fixed-effects model indicated that Burundiās GDP, her trade partnersā populations, exchange rate, distance, being under the same colony and belonging to a regional trading bloc such as EAC and COMESA are the main factors determining food imports. The choice of trade instruments to use may seek to facilitate trade by reducing unnecessary tariff and non-tariff barriers but in a reciprocal agreement and dispensation of bilateral and multilateral protocols. Keywords: Gravity model, Agri-food, Imports, random fixed effects and Burund
The Cost-Effectiveness of Intermittent Preventive Treatment for Malaria in Infants in Sub-Saharan Africa
BACKGROUND: Intermittent preventive treatment in infants (IPTi) has been shown to decrease clinical malaria by approximately 30% in the first year of life and is a promising malaria control strategy for Sub-Saharan Africa which can be delivered alongside the Expanded Programme on Immunisation (EPI). To date, there have been limited data on the cost-effectiveness of this strategy using sulfadoxine pyrimethamine (SP) and no published data on cost-effectiveness using other antimalarials. METHODS: We analysed data from 5 countries in sub-Saharan Africa using a total of 5 different IPTi drug regimens; SP, mefloquine (MQ), 3 days of chlorproguanil-dapsone (CD), SP plus 3 days of artesunate (SP-AS3) and 3 days of amodiaquine-artesunate (AQ3-AS3).The cost per malaria episode averted and cost per Disability-Adjusted Life-Year (DALY) averted were modeled using both trial specific protective efficacy (PE) for all IPTi drugs and a pooled PE for IPTi with SP, malaria incidence, an estimated malaria case fatality rate of 1.57%, IPTi delivery costs and country specific provider and household malaria treatment costs. FINDINGS: In sites where IPTi had a significant effect on reducing malaria, the cost per episode averted for IPTi-SP was very low, USD 1.36-4.03 based on trial specific data and USD 0.68-2.27 based on the pooled analysis. For IPTi using alternative antimalarials, the lowest cost per case averted was for AQ3-AS3 in western Kenya (USD 4.62) and the highest was for MQ in Korowge, Tanzania (USD 18.56). Where efficacious, based only on intervention costs, IPTi was shown to be cost effective in all the sites and highly cost-effective in all but one of the sites, ranging from USD 2.90 (Ifakara, Tanzania with SP) to USD 39.63 (Korogwe, Tanzania with MQ) per DALY averted. In addition, IPTi reduced health system costs and showed significant savings to households from malaria cases averted. A threshold analysis showed that there is room for the IPTi-efficacy to fall and still remain highly cost effective in all sites where IPTi had a statistically significant effect on clinical malaria. CONCLUSIONS: IPTi delivered alongside the EPI is a highly cost effective intervention against clinical malaria with a range of drugs in a range of malaria transmission settings. Where IPTi did not have a statistically significant impact on malaria, generally in low transmission sites, it was not cost effective
Global incidence, prevalence, years lived with disability (YLDs), disability-adjusted life-years (DALYs), and healthy life expectancy (HALE) for 371 diseases and injuries in 204 countries and territories and 811 subnational locations, 1990ā2021: a systematic analysis for the Global Burden of Disease Study 2021
Background: Detailed, comprehensive, and timely reporting on population health by underlying causes of disability and premature death is crucial to understanding and responding to complex patterns of disease and injury burden over time and across age groups, sexes, and locations. The availability of disease burden estimates can promote evidence-based interventions that enable public health researchers, policy makers, and other professionals to implement strategies that can mitigate diseases. It can also facilitate more rigorous monitoring of progress towards national and international health targets, such as the Sustainable Development Goals. For three decades, the Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) has filled that need. A global network of collaborators contributed to the production of GBD 2021 by providing, reviewing, and analysing all available data. GBD estimates are updated routinely with additional data and refined analytical methods. GBD 2021 presents, for the first time, estimates of health loss due to the COVID-19 pandemic. Methods: The GBD 2021 disease and injury burden analysis estimated years lived with disability (YLDs), years of life lost (YLLs), disability-adjusted life-years (DALYs), and healthy life expectancy (HALE) for 371 diseases and injuries using 100 983 data sources. Data were extracted from vital registration systems, verbal autopsies, censuses, household surveys, disease-specific registries, health service contact data, and other sources. YLDs were calculated by multiplying cause-age-sex-location-year-specific prevalence of sequelae by their respective disability weights, for each disease and injury. YLLs were calculated by multiplying cause-age-sex-location-year-specific deaths by the standard life expectancy at the age that death occurred. DALYs were calculated by summing YLDs and YLLs. HALE estimates were produced using YLDs per capita and age-specific mortality rates by location, age, sex, year, and cause. 95% uncertainty intervals (UIs) were generated for all final estimates as the 2Ā·5th and 97Ā·5th percentiles values of 500 draws. Uncertainty was propagated at each step of the estimation process. Counts and age-standardised rates were calculated globally, for seven super-regions, 21 regions, 204 countries and territories (including 21 countries with subnational locations), and 811 subnational locations, from 1990 to 2021. Here we report data for 2010 to 2021 to highlight trends in disease burden over the past decade and through the first 2 years of the COVID-19 pandemic. Findings: Global DALYs increased from 2Ā·63 billion (95% UI 2Ā·44ā2Ā·85) in 2010 to 2Ā·88 billion (2Ā·64ā3Ā·15) in 2021 for all causes combined. Much of this increase in the number of DALYs was due to population growth and ageing, as indicated by a decrease in global age-standardised all-cause DALY rates of 14Ā·2% (95% UI 10Ā·7ā17Ā·3) between 2010 and 2019. Notably, however, this decrease in rates reversed during the first 2 years of the COVID-19 pandemic, with increases in global age-standardised all-cause DALY rates since 2019 of 4Ā·1% (1Ā·8ā6Ā·3) in 2020 and 7Ā·2% (4Ā·7ā10Ā·0) in 2021. In 2021, COVID-19 was the leading cause of DALYs globally (212Ā·0 million [198Ā·0ā234Ā·5] DALYs), followed by ischaemic heart disease (188Ā·3 million [176Ā·7ā198Ā·3]), neonatal disorders (186Ā·3 million [162Ā·3ā214Ā·9]), and stroke (160Ā·4 million [148Ā·0ā171Ā·7]). However, notable health gains were seen among other leading communicable, maternal, neonatal, and nutritional (CMNN) diseases. Globally between 2010 and 2021, the age-standardised DALY rates for HIV/AIDS decreased by 47Ā·8% (43Ā·3ā51Ā·7) and for diarrhoeal diseases decreased by 47Ā·0% (39Ā·9ā52Ā·9). Non-communicable diseases contributed 1Ā·73 billion (95% UI 1Ā·54ā1Ā·94) DALYs in 2021, with a decrease in age-standardised DALY rates since 2010 of 6Ā·4% (95% UI 3Ā·5ā9Ā·5). Between 2010 and 2021, among the 25 leading Level 3 causes, age-standardised DALY rates increased most substantially for anxiety disorders (16Ā·7% [14Ā·0ā19Ā·8]), depressive disorders (16Ā·4% [11Ā·9ā21Ā·3]), and diabetes (14Ā·0% [10Ā·0ā17Ā·4]). Age-standardised DALY rates due to injuries decreased globally by 24Ā·0% (20Ā·7ā27Ā·2) between 2010 and 2021, although improvements were not uniform across locations, ages, and sexes. Globally, HALE at birth improved slightly, from 61Ā·3 years (58Ā·6ā63Ā·6) in 2010 to 62Ā·2 years (59Ā·4ā64Ā·7) in 2021. However, despite this overall increase, HALE decreased by 2Ā·2% (1Ā·6ā2Ā·9) between 2019 and 2021. Interpretation: Putting the COVID-19 pandemic in the context of a mutually exclusive and collectively exhaustive list of causes of health loss is crucial to understanding its impact and ensuring that health funding and policy address needs at both local and global levels through cost-effective and evidence-based interventions. A global epidemiological transition remains underway. Our findings suggest that prioritising non-communicable disease prevention and treatment policies, as well as strengthening health systems, continues to be crucially important. The progress on reducing the burden of CMNN diseases must not stall; although global trends are improving, the burden of CMNN diseases remains unacceptably high. Evidence-based interventions will help save the lives of young children and mothers and improve the overall health and economic conditions of societies across the world. Governments and multilateral organisations should prioritise pandemic preparedness planning alongside efforts to reduce the burden of diseases and injuries that will strain resources in the coming decades. Funding: Bill & Melinda Gates Foundation
HYDRA: Parallel and distributed swarm computer architecture.
The research in computer architecture for agent-based parallel and distributed processing was prompted by the interest and the related ongoing work in agent-based computing. Agent-based computing best suits the Internet (a collection of computers interconnected by high speed communication links) in which every computer or host is an entity. Agents enable the user to search the internet offline as compared to online. The user is freed to attend to task requiring the user's intervention and the user only logs to the network to check the results returned by the agent. A number of agent-based systems have been implemented. The TACOMA, Telescript and WAVE are based on an interpreted engine (program code) running in the background, accepting and interpreting the user inputs. The Swarm system on the other hand, is based on compiled program code which is stored at each host. The agent navigate the network based on destination address (PM address in Swarm, another agent in TACOMA, a place in Telescript or a node address in WAVE). In the interpreted program based systems, the agent carries with it the code to be executed at the reached destination, while in the Swarm system, the agent carries the instruction pointer, pointing to the next instruction to be executed at the reached destination. HYDRA; A Parallel and Distributed Swarm computer architecture for agent processing is based on a single user Swarm computer architecture prototype developed and simulated on a single host by [Errico 1996]. Agents are self contained executable mobile processes that navigate a network of hosts using hosts' addresses, executing a task, and when the task terminates, the outcome of the task execution is sent to the user. Swarm consists of three modules: the AP (Access Point) through which the user can access the Swarm computer to run tasks, the RM (Routing Module), responsible for routing the agents in the Swarm computer, and the PM (Processing Module), which is the execution engine in the Swarm computer. A PM is the destination of an executing agent. The aim of the thesis was to simulate the Swarm computer architecture in a distributed environment, where the PMs are distributed among several hosts in the network. The distributed environment consists of a few or several hosts connected together by an interconnection network. Hosts on the network are grouped into domains, and the domains are interconnected together to form a network. Hosts in a domain are directly connected to every other host within that domain. Within a domain, a single host acts as a gateway host handling extra-domain agents. To enable me achieve my goal, I designed, implemented and tested a Communication Router (CR). The CR consists of Network Router (NR) and the Routing Module (RM). The CR has two main functions: 1. Provide connectivity among the hosts in the network. 2. Route agents between the hosts. To be able to connect host on the network and to route agents between them, I developed a connection algorithm, and a routing algorithm. The connection algorithm logically connects hosts in the same domain, builds a routing table at each host, and identifies a gateway host for each domain. The routing algorithm, using the routing table at each host ensures delivery of agents to their proper destinations, irrespective of the location of the Processing Module. Simulation tests were carried on the the HYDRA computer prototype, and the preliminary test results obtained do show that the connection, and routing algorithms were respectively able to connect the hosts, and to route agents between the hosts. And, that agents and the HYDRA computer architecture could be used to do some useful work. In this thesis I present the HYDRA computer architecture, the work done in the design, and implementation of the Network Router, Routing Module, Access Point, the connection algorithm, the routing table, the agent routing algorithm, the communication strategy adopted for routing messages in the network, the simulation tests carried out, and the test results obtained
HYDRA: Parallel and distributed swarm computer architecture.
The research in computer architecture for agent-based parallel and distributed processing was prompted by the interest and the related ongoing work in agent-based computing. Agent-based computing best suits the Internet (a collection of computers interconnected by high speed communication links) in which every computer or host is an entity. Agents enable the user to search the internet offline as compared to online. The user is freed to attend to task requiring the user's intervention and the user only logs to the network to check the results returned by the agent. A number of agent-based systems have been implemented. The TACOMA, Telescript and WAVE are based on an interpreted engine (program code) running in the background, accepting and interpreting the user inputs. The Swarm system on the other hand, is based on compiled program code which is stored at each host. The agent navigate the network based on destination address (PM address in Swarm, another agent in TACOMA, a place in Telescript or a node address in WAVE). In the interpreted program based systems, the agent carries with it the code to be executed at the reached destination, while in the Swarm system, the agent carries the instruction pointer, pointing to the next instruction to be executed at the reached destination. HYDRA; A Parallel and Distributed Swarm computer architecture for agent processing is based on a single user Swarm computer architecture prototype developed and simulated on a single host by [Errico 1996]. Agents are self contained executable mobile processes that navigate a network of hosts using hosts' addresses, executing a task, and when the task terminates, the outcome of the task execution is sent to the user. Swarm consists of three modules: the AP (Access Point) through which the user can access the Swarm computer to run tasks, the RM (Routing Module), responsible for routing the agents in the Swarm computer, and the PM (Processing Module), which is the execution engine in the Swarm computer. A PM is the destination of an executing agent. The aim of the thesis was to simulate the Swarm computer architecture in a distributed environment, where the PMs are distributed among several hosts in the network. The distributed environment consists of a few or several hosts connected together by an interconnection network. Hosts on the network are grouped into domains, and the domains are interconnected together to form a network. Hosts in a domain are directly connected to every other host within that domain. Within a domain, a single host acts as a gateway host handling extra-domain agents. To enable me achieve my goal, I designed, implemented and tested a Communication Router (CR). The CR consists of Network Router (NR) and the Routing Module (RM). The CR has two main functions: 1. Provide connectivity among the hosts in the network. 2. Route agents between the hosts. To be able to connect host on the network and to route agents between them, I developed a connection algorithm, and a routing algorithm. The connection algorithm logically connects hosts in the same domain, builds a routing table at each host, and identifies a gateway host for each domain. The routing algorithm, using the routing table at each host ensures delivery of agents to their proper destinations, irrespective of the location of the Processing Module. Simulation tests were carried on the the HYDRA computer prototype, and the preliminary test results obtained do show that the connection, and routing algorithms were respectively able to connect the hosts, and to route agents between the hosts. And, that agents and the HYDRA computer architecture could be used to do some useful work. In this thesis I present the HYDRA computer architecture, the work done in the design, and implementation of the Network Router, Routing Module, Access Point, the connection algorithm, the routing table, the agent routing algorithm, the communication strategy adopted for routing messages in the network, the simulation tests carried out, and the test results obtained
NET-Computer: Internet Computer Architecture and its Application in E-Commerce
Abstract ā Research in Intelligent Agents has yielded interesting results, some of which have been translated into commercial ventures. Intelligent Agents are executable software components that represent the user, perform tasks on behalf of the user and when the task terminates, the Agents send the result to the user. Intelligent Agents are best suited for the Internet: a collection of computers connected together in a world-wide computer network. Swarm and HYDRA computer architectures for Agents ā execution were developed at the University of Surrey, UK in the 90s. The objective of the research was to develop a software-based computer architecture on which Agents execution could be explored. The combination of Intelligent Agents and HYDRA computer architecture gave rise to a new computer concept: the NET-Computer in which the computing resources reside on the Internet. The Internet computers form the hardware and software resources, and the user is provided with a simple interface to access the Internet and run user tasks. The Agents autonomously roam the Internet (NET-Computer) executing the tasks. A growing segment of the Internet is E-Commerce for online shopping for products and services. The Internet computing resources provide a marketplace for product suppliers and consumers alike. Consumers are looking for suppliers selling products and services, while suppliers are looking for buyers. Searching the vast amount of information available on the Internet causes a great deal of problems for both consumers and suppliers. Intelligent Agents executing on the NET-Computer can surf through the Internet and select specific information of interest to the user. The simulation results show that Intelligent Agents executing HYDRA computer architecture could be applied in E-Commerce
Cause-specific mortality in Africa and Asia: evidence from INDEPTH health and demographic surveillance system sites.
BACKGROUND: Because most deaths in Africa and Asia are not well documented, estimates of mortality are often made using scanty data. The INDEPTH Network works to alleviate this problem by collating detailed individual data from defined Health and Demographic Surveillance sites. By registering all deaths over time and carrying out verbal autopsies to determine cause of death across many such sites, using standardised methods, the Network seeks to generate population-based mortality statistics that are not otherwise available. OBJECTIVE: To build a large standardised mortality database from African and Asian sites, detailing the relevant methods, and use it to describe cause-specific mortality patterns. DESIGN: Individual demographic and verbal autopsy (VA) data from 22 INDEPTH sites were collated into a standardised database. The INDEPTH 2013 population was used for standardisation. The WHO 2012 VA standard and the InterVA-4 model were used for assigning cause of death. RESULTS: A total of 111,910 deaths occurring over 12,204,043 person-years (accumulated between 1992 and 2012) were registered across the 22 sites, and for 98,429 of these deaths (88.0%) verbal autopsies were successfully completed. There was considerable variation in all-cause mortality between sites, with most of the differences being accounted for by variations in infectious causes as a proportion of all deaths. CONCLUSIONS: This dataset documents individual deaths across Africa and Asia in a standardised way, and on an unprecedented scale. While INDEPTH sites are not constructed to constitute a representative sample, and VA may not be the ideal method of determining cause of death, nevertheless these findings represent detailed mortality patterns for parts of the world that are severely under-served in terms of measuring mortality. Further papers explore details of mortality patterns among children and specifically for NCDs, external causes, pregnancy-related mortality, malaria, and HIV/AIDS. Comparisons will also be made where possible with other findings on mortality in the same regions. Findings presented here and in accompanying papers support the need for continued work towards much wider implementation of universal civil registration of deaths by cause on a worldwide basis
Democracy and its discontents: understanding Kenyaās 2013 elections
In the months leading up to Kenya's general election in March 2013, there was much concern ā both within Kenya itself and internationally ā that political competition would trigger a fresh wave of ethnic violence. However, the 2013 elections passed off largely peacefully, despite an unexpected presidential result and fact that the losing candidate, Raila Odinga, appealed the outcome to the Supreme Court. This article argues that Kenya avoided political unrest as a result of four interconnected processes. A dramatic political realignment brought former rivals together and gave them an incentive to diffuse ethnic tensions; a pervasive āpeace narrativeā delegitimized political activity likely to lead to political instability; partial democratic reforms conferred new legitimacy on the electoral and political system; and a new constitution meant that many voters who ālostā nationally in the presidential election āwonā in local contests. This election thus provides two important lessons for the democratization literature. First, processes of gradual reform may generate more democratic political systems in the long-run, but in the short-run they can empower the political establishment. Second, sacrificing justice on the altar of stability risks a ānegative peaceā that may be associated with an increased sense of marginalization and exclusion among some communities ā raising the prospects for unrest in the future