16 research outputs found

    Quantifying the daily economic impact of extreme space weather due to failure in electricity transmission infrastructure

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    Extreme space weather due to coronal mass ejections has the potential to cause considerable disruption to the global economy by damaging the transformers required to operate electricity transmission infrastructure. However, expert opinion is split between the potential outcome being one of a temporary regional blackout and of a more prolonged event. The temporary blackout scenario proposed by some is expected to last the length of the disturbance, with normal operations resuming after a couple of days. On the other hand, others have predicted widespread equipment damage with blackout scenarios lasting months. In this paper we explore the potential costs associated with failure in the electricity transmission infrastructure in the U.S. due to extreme space weather, focusing on daily economic loss. This provides insight into the direct and indirect economic consequences of how an extreme space weather event may affect domestic production, as well as other nations, via supply chain linkages. By exploring the sensitivity of the blackout zone, we show that on average the direct economic cost incurred from disruption to electricity represents only 49% of the total potential macroeconomic cost. Therefore, if indirect supply chain costs are not considered when undertaking cost-benefit analysis of space weather forecasting and mitigation investment, the total potential macroeconomic cost is not correctly represented. The paper contributes to our understanding of the economic impact of space weather, as well as making a number of key methodological contributions relevant for future work. Further economic impact assessment of this threat must consider multiday, multiregional event

    Insecticide-treated net effectiveness at preventing Plasmodium falciparum infection varies by age and season

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    Abstract Background After increasing coverage of malaria interventions, malaria prevalence remains high in Malawi. Previous studies focus on the impact of malaria interventions among children under 5 years old. However, in Malawi, the prevalence of infection is highest in school-aged children (SAC), ages 5 to 15 years. This study examined the interaction between age group and insecticide-treated net (ITN) use for preventing individual and community-level infection in Malawi. Methods Six cross-sectional surveys were conducted in the rainy and dry seasons in southern Malawi from 2012 to 2014. Data were collected on household ITN usage and demographics. Blood samples for detection of Plasmodium falciparum infection were obtained from all household members present and over 6 months of age. Generalized linear mixed models were used to account for clustering at the household and community level. Results There were 17,538 observations from six surveys. The association between ITN use and infection varied by season in SAC, but not in other age groups. The adjusted odds ratio (OR) for infection comparing ITN users to non-users among SAC in the rainy season and dry season was 0.78 (95% CI 0.56, 1.10) and 0.51 (0.35, 0.74), respectively. The effect of ITN use did not differ between children under five and adults. Among all non-SACs the OR for infection was 0.78 (0.64, 0.95) in those who used ITNs compared to those that did not. Community net use did not protect against infection. Conclusions Protection against infection with ITN use varies by age group and season. Individual estimates of protection are moderate and a community-level effect was not detected. Additional interventions to decrease malaria prevalence are needed in Malawi.http://deepblue.lib.umich.edu/bitstream/2027.42/135726/1/12936_2017_Article_1686.pd

    Bed net use among school-aged children after a universal bed net campaign in Malawi

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    Abstract Background Recent data from Malawi suggest that school-aged children (SAC), aged 5–15 years, have the highest prevalence of Plasmodium falciparum infection among all age groups. They are the least likely group to utilize insecticide-treated nets (ITNs), the most commonly available intervention to prevent malaria in Africa. This study examined the effects of a universal ITN distribution campaign, and their durability over time in SAC in Malawi. This study identified factors that influence net usage among SAC and how these factors changed over time. Methods Cross-sectional surveys using cluster random sampling were conducted at the end of each rainy and dry season in southern Malawi from 2012 to 2014; six surveys were done in total. Mass net distribution occurred between the first and second surveys. Data were collected on household and individual net usage as well as demographic information. Statistical analyses used generalized linear mixed models to account for clustering at the household and neighbourhood level. Results There were 7347 observations from SAC and 14,785 from young children and adults. SAC used nets significantly less frequently than the rest of the population (odds ratio (OR) from 0.14 to 0.38). The most important predictors of net usage among SAC were a lower ratio of people to nets in a household and higher proportion of nets that were hanging at the time of survey. Older SAC (11–15 years) were significantly less likely to use nets than younger SAC (5–10 years) [OR = 0.24 (95 % CI: 0.21, 0.28)]. The universal bed net campaign led to a statistically significant population-wide increase in net use, however net use returned to near baseline within 3 years. Conclusions This study suggests that a single universal net distribution campaign, in combination with routine distribution through health clinics is not sufficient to cause a sustained increase in net usage among SAC. Novel approaches to ITN distribution, such as school-based distribution, may be needed to address the high prevalence of infection in SAC.http://deepblue.lib.umich.edu/bitstream/2027.42/134523/1/12936_2016_Article_1178.pd

    Critical reflection on knowledge and narratives of conservation agriculture

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    In the context of contemporary concerns about climate change and food security, Conservation Agriculture (CA) has emerged as a well-supported and central component of the agricultural sector development strategy across sub-Saharan Africa, including in Zambia, which is the focus of this paper. A variety of narratives about the benefits of CA over conventional agricultural systems underpin endeavours towards ‘scaling up’ CA and increasing rates of adoption amongst smallholder farmers nationwide. However, there is a knowledge politics underlying the translation of a weak evidence base around CA into persuasive narratives and financial and political support. In this paper, we trace the evolution of five narratives around CA in Zambia in relation to changing political agendas and the involvement of new public and private sector actors, and review the development of evidence bases and knowledge that support and challenge each of these narratives. We discuss the potential to open up space within this knowledge politics to alternative narratives and the contestation of the pervasive CA scaling up agenda. Critical reflection is essential to ensure that national and local evidence is more effectively used to guide national climate and agricultural policy developments and international donor initiatives

    Mycobacterium vaccae (SRL172) immunotherapy as an adjunct to standard antituberculosis treatment in HIV-infected adults with pulmonary tuberculosis: a randomised placebo-controlled trial.

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    BACKGROUND: Mortality rates of HIV-infected patients treated for tuberculosis remain high. This study aimed to assess the effect on mortality of immunotherapy with single-dose SRL172 added to standard antituberculosis chemotherapy in such patients. METHODS: The double-blind trial enrolled 1229 patients aged 18-60 years, who had never received antiretroviral treatment and who presented with newly diagnosed, sputum-smear-positive pulmonary tuberculosis to referral centres in Lusaka, Zambia, and Karonga, Malawi. Both HIV-positive and HIV-negative patients were enrolled, to avoid stigmatisation. Participants were randomly assigned a single injection of SRL172 or matching placebo within 2 weeks of starting 8 months of antituberculosis chemotherapy and followed up for at least 12 months. The primary endpoint was time to death in the HIV-infected population. Analyses were based on 760 HIV-positive patients after exclusion of 84 patients with errors in storage of the injection, no bacteriological confirmation, or no HIV result. FINDINGS: Of 760 HIV-infected patients, 374 received SRL172 and 386 received placebo. SRL172 did not cause any serious adverse events. The follow-up rate was 88% at 12 months in both groups. Of the HIV-positive patients, 109 (19.5 per 100 person-years) of 372 assigned SRL172 and 107 (19.3 per 100 person-years) of 386 assigned placebo died. In the Cox's regression analysis, stratified by centre, the hazard ratio of deaths (SRL172/placebo) was 1.03 (95% CI 0.79-1.35). There was no evidence of benefit to the group assigned SRL172. INTERPRETATION: Immunotherapy with single-dose SRL172 as an adjunct to standard antituberculosis treatment in HIV-positive adults with pulmonary tuberculosis had no significant effect on survival or bacteriological outcome, though the treatment was safe and well tolerated

    Dynamic Response of Ionospheric Plasma Density to the Geomagnetic Storm of 22‐23 June 2015

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    International audienceOn 21-22 June 2015, three consecutive interplanetary shocks slammed into the Earth's magnetosphere. Immediately after the third shock at 18:36 UT on 22 June, marked by an exceptional sudden storm commencement with an amplitude of Delta SYM-H = similar to 106 nT, a major geomagnetic storm commenced. In the present study, a multi-instrument approach comprising observations, data analysis, and modeling is used to examine the global ionospheric response. Results show that enhanced storm time processes produced major total electron content (TEC) variations at different latitudes, longitudes, and phases of the storm. A closer inspection of the TEC observations reveals strong longitudinal and hemispherical asymmetry. In addition, multiple equatorward and poleward propagating traveling ionospheric disturbances (TIDs) were detected in the TEC data. Equatorward propagating TIDs are consistent with vertical neutral winds simulated from Thermosphere-Ionosphere-Electrodynamics General Circulation Model; however, poleward TIDs were not reproduced in the model. We find that a combination of driving processes including enhanced high-latitude injection, prompt penetration electric fields, disturbance dynamo effect, neutral winds, and composition changes were acting at different stages of the stor

    RESEARCH What makes staff consider leaving the health service in Malawi? Open Access

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    Background: Malawi faces a severe shortage of health workers, a factor that has contributed greatly to high maternal mortality in the country. Most clinical care is performed by mid-level providers (MLPs). While utilization of these cadres in providing health care is a solution to the current shortages, demotivating factors within the Malawian health system are pushing them into private, non-governmental, and other non-health related positions. This study aims to highlight these demotivating factors by exploring the critical aspects that influence MLPs’ intention to leave their jobs. Methods: This descriptive qualitative study formed part of the larger Health Systems Strengthening for Equity (HSSE) study. Data presented in this paper were collected in Malawi using the Critical Incident Analysis tool. Participants were asked to narrate an incident that had happened during the past three months which had made them seriously consider leaving their job. Data were subjected to thematic analysis using NVivo 8 software. Results: Of the 84 respondents who participated in a Critical Incident Analysis interview, 58 respondents (69%) indicated they had experienced a demotivating incident in the previous three months that had made them seriously consider leaving their job. The most commonly cited critical factors were being treated unfairly or with disrespect, lack of recognition of their efforts, delays and inconsistencies in salary payments, lack of transparen

    A Cross-Sectional Study of Household Biomass Fuel Use among a Periurban Population in Malawi

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    Rationale: The Global Burden of Disease Study suggests almost 3.5 million people die as a consequence of household air pollution every year. Respiratory diseases including chronic obstructive pulmonary disease and pneumonia in children are strongly associated with exposure to household air pollution. Smoke from burning biomass fuels for cooking, heating, and lighting is the main contributor to high household air pollution levels in low-income countries like Malawi. A greater understanding of biomass fuel use in Malawi should enable us to address household air pollution–associated communicable and noncommunicable diseases more effectively. Objectives: To conduct a cross-sectional analysis of biomass fuel use and population demographics among adults in Blantyre, Malawi. Methods: We used global positioning system–enabled personal digital assistants to collect data on location, age, sex, marital status, education, occupation, and fuel use. We describe these data and explore associations between demographics and reported fuel type. Measurements and Main Results: A total of 16,079 adults participated (nine households refused); median age was 30 years, there was a similar distribution of men and women, 60% were married, and 62% received secondary school education. The most commonly reported occupation for men and women was “salaried employment” (40.7%) and “petty trader and marketing” (23.5%), respectively. Charcoal (81.5% of households), wood (36.5%), and electricity (29.1%) were the main fuels used at home. Only 3.9% of households used electricity exclusively. Lower educational and occupational attainment was associated with greater use of wood. Conclusions: This large cross-sectional study has identified extensive use of biomass fuels in a typical sub-Saharan Africa periurban population in which women and people of lower socioeconomic status are disproportionately affected. Biomass fuel use is likely to be a major driver of existing communicable respiratory disease and the emerging noncommunicable disease (especially respiratory and cardiovascular) epidemic in this region. Our data will help inform the rationale for specific intervention studies and the development of appropriately targeted public health strategies to tackle this important and poverty-related global health problem

    Effect of rotavirus vaccine on severe diarrhea in African infants

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    BACKGROUND: Rotavirus is the most common cause of severe gastroenteritis among young children worldwide. Data are needed to assess the efficacy of the rotavirus vaccine in African children. METHODS: We conducted a randomized, placebo-controlled, multicenter trial in South Africa (3166 infants; 64.1% of the total) and Malawi (1773 infants; 35.9% of the total) to evaluate the efficacy of a live, oral rotavirus vaccine in preventing severe rotavirus gastroenteritis. Healthy infants were randomly assigned in a 1:1:1 ratio to receive two doses of vaccine (in addition to one dose of placebo) or three doses of vaccine — the pooled vaccine group — or three doses of placebo at 6, 10, and 14 weeks of age. Episodes of gastroenteritis caused by wild-type rotavirus during the first year of life were assessed through active follow-up surveillance and were graded with the use of the Vesikari scale. RESULTS: A total of 4939 infants were enrolled and randomly assigned to one of the three groups; 1647 infants received two doses of the vaccine, 1651 infants received three doses of the vaccine, and 1641 received placebo. Of the 4417 infants included in the per-protocol efficacy analysis, severe rotavirus gastroenteritis occurred in 4.9% of the infants in the placebo group and in 1.9% of those in the pooled vaccine group (vaccine efficacy, 61.2%; 95% confidence interval, 44.0 to 73.2). Vaccine efficacy was lower in Malawi than in South Africa (49.4% vs. 76.9%); however, the number of episodes of severe rotavirus gastroenteritis that were prevented was greater in Malawi than in South Africa (6.7 vs. 4.2 cases prevented per 100 infants vaccinated per year). Efficacy against all-cause severe gastroenteritis was 30.2%. At least one serious adverse event was reported in 9.7% of the infants in the pooled vaccine group and in 11.5% of the infants in the placebo group. CONCLUSIONS: Human rotavirus vaccine significantly reduced the incidence of severe rotavirus gastroenteritis among African infants during the first year of life. (ClinicalTrials.gov number, NCT00241644.

    Mainstreaming conservation agriculture in Malawi: Knowledge gaps and institutional barriers

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    Conservation agriculture (CA) practices of reduced soil tillage, permanent organic soil coverage and intercropping/crop rotation, are being advocated globally, based on perceived benefits for crop yields, soil carbon storage, weed suppression, reduced soil erosion and improved soil water retention. However, some have questioned their efficacy due to uncertainty around the performance and trade-offs associated with CA practices, and their compatibility with the diverse livelihood strategies and varied agro-ecological conditions across African smallholder systems. This paper assesses the role of key institutions in Malawi in shaping pathways towards more sustainable land management based on CA by outlining their impact on national policy-making and the design and implementation of agricultural development projects. It draws on interviews at national, district and project levels and a multi-stakeholder workshop that mapped the institutional landscape of decision-making for agricultural land management practices. Findings identify knowledge gaps and institutional barriers that influence land management decision-making and constrain CA uptake. We use our findings to set out an integrated roadmap of research needs and policy options aimed at supporting CA as a route to enhanced sustainable land management in Malawi. Findings offer lessons that can inform design, planning and implementation of CA projects, and identify the multi-level institutional support structures required for mainstreaming sustainable land management in sub-Saharan Africa
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