The linkages between agriculture and malaria: Issues for policy, research, and capacity strengthening

"Malaria afflicts many people in the developing world, and due to its direct and indirect costs it has widespread impacts on growth and development. The global impact of malaria on human health, productivity, and general well-being is profound. Human activity, including agriculture, has been recognized as one of the reasons for the increased intensity of malaria around the world, because it supports the breeding of mosquitoes that carry the malaria parasite. Malaria can cause illness (morbidity), disability, or death; and all three effects have direct and indirect costs that can affect productivity. Since agriculture is the main activity of rural people in many endemic areas, it has been suggested that effective malaria control measures can be devised if attention was paid to the two-way effects of agriculture and malaria. There is the need to compute the direct costs of malaria treatment and control and the impacts of those costs on the ability of farm households to adopt new agricultural technology and improved practices, and keep farm and household assets. It is equally important to know the indirect costs of seeking health care and taking care of children and others who are afflicted by malaria and the relationship of the indirect costs to the farm labor supply and productivity. On the other hand, many agricultural activities like irrigation projects, water-harvesting and storage, land and soil management techniques, and farm work sequencing can lead to increase in mosquito populations and therefore increase the incidence of malaria in agricultural regions. This paper has raised issues on the two-way effects of agriculture and malaria and recommended areas that require policy actions and further research. The research findings can then be used in devising effective policies for controlling malaria in endemic areas of the world and assist in preparing a tool kit for capacity development on agriculture and malaria." from authors' abstractMalaria, Agriculture, Development, technology, Impact, Research, Policy, Capacity strengthening, Innovation, Institutional change, Science and technology,

Cognitive outcomes in early-treated adults with phenylketonuria (PKU):a comprehensive picture across domains

OBJECTIVE: Phenylketonuria (PKU) is an inherited metabolic disease which affects cognitive functions due to an inability to metabolize phenylalanine which leads to the accumulation of toxic by-products (Phe) in the brain. PKU can be effectively treated with a low phenylalanine diet, but some cognitive deficits remain. Studies have reported impairments, especially for processing speed and executive functions, but there is a lack of comprehensive assessment across cognitive domains. Moreover, it is important to establish outcomes in early treated adults with PKU (AwPKU) who have better metabolic control than groups previously reported in the literature. METHOD: We tested 37 AwPKU with an unprecedented number of tasks (N = 28) and measures (N = 44) and compared results with 30 controls matched for age and education. RESULTS: We found (a) group impairments, particularly in tasks tapping speed of processing and complex executive functions; (b) high variability across participants, with a sizable number of AwPKU with completely normal performance (about 38%); (c) but also a sizable number of participants who were clearly impaired (about 24%); and (d) good performance in tasks tapping verbal learning, verbal memory and orthographic processing, indicating no generalized learning impairment. CONCLUSION: Our results indicate good outcomes, but also that deficits are still present with current treatment policies. (PsycINFO Database Recor

The impact of phenylalanine levels on cognitive outcomes in adults with phenylketonuria:effects across tasks and developmental stages

OBJECTIVE: Phenylketonuria (PKU) is due to an inability to metabolize the amino acid phenylalanine (Phe), leading to its accumulation in the brain. Phe levels can be controlled following a protein-free diet, but cognitive impairments are still present. A number of questions remain to be answered related to which type of metabolic control is important, the age when it is important, the cognitive functions which are most affected and, the best tests to use to monitor cognitive health. METHOD: We investigated the impact of metabolic control at different ages on cognitive performance in 37 early treated adults with PKU. RESULTS: (a) Phe variation was as associated to performance as average Phe showing that stable dietary control is as important as strict control; (b) For some tasks, current and adult Phe were stronger predictors of performance than childhood or adolescent Phe, showing the importance of a strict diet even in adulthood; and (c) The relationship between performance and Phe levels varied depending on time and cognitive domain. For some functions (sustained attention, visuomotor coordination), Phe at the time of testing was the best predictor. While for other functions (visual attention, executive functions) there was a diminishing or stable relationship across time. CONCLUSION: Results show the importance of selecting the right tasks to monitor outcomes across ages, but also that the impact of bio-chemical disruptions is different for different functions, at different ages. We show how inherited metabolic diseases offer us a unique vantage point to inform our understanding of brain development and functioning. (PsycINFO Database Recor

Evidence for a Common Origin of Blacksmiths and Cultivators in the Ethiopian Ari within the Last 4500 Years: Lessons for Clustering-Based Inference.

The Ari peoples of Ethiopia are comprised of different occupational groups that can be distinguished genetically, with Ari Cultivators and the socially marginalised Ari Blacksmiths recently shown to have a similar level of genetic differentiation between them (FST ≈ 0.023 - 0.04) as that observed among multiple ethnic groups sampled throughout Ethiopia. Anthropologists have proposed two competing theories to explain the origins of the Ari Blacksmiths as (i) remnants of a population that inhabited Ethiopia prior to the arrival of agriculturists (e.g. Cultivators), or (ii) relatively recently related to the Cultivators but presently marginalized in the community due to their trade. Two recent studies by different groups analysed genome-wide DNA from samples of Ari Blacksmiths and Cultivators and suggested that genetic patterns between the two groups were more consistent with model (i) and subsequent assimilation of the indigenous peoples into the expanding agriculturalist community. We analysed the same samples using approaches designed to attenuate signals of genetic differentiation that are attributable to allelic drift within a population. By doing so, we provide evidence that the genetic differences between Ari Blacksmiths and Cultivators can be entirely explained by bottleneck effects consistent with hypothesis (ii). This finding serves as both a cautionary tale about interpreting results from unsupervised clustering algorithms, and suggests that social constructions are contributing directly to genetic differentiation over a relatively short time period among previously genetically similar groups

One-dimensional collision carts computer model and its design ideas for productive experiential learning

We develop an Easy Java Simulation (EJS) model for students to experience the physics of idealized one-dimensional collision carts. The physics model is described and simulated by both continuous dynamics and discrete transition during collision. In the field of designing computer simulations, we discuss briefly three pedagogical considerations such as 1) consistent simulation world view with pen paper representation, 2) data table, scientific graphs and symbolic mathematical representations for ease of data collection and multiple representational visualizations and 3) game for simple concept testing that can further support learning. We also suggest using physical world setup to be augmented complimentary with simulation while highlighting three advantages of real collision carts equipment like tacit 3D experience, random errors in measurement and conceptual significance of conservation of momentum applied to just before and after collision. General feedback from the students has been relatively positive, and we hope teachers will find the simulation useful in their own classes. 2015 Resources added: http://iwant2study.org/ospsg/index.php/interactive-resources/physics/02-newtonian-mechanics/02-dynamics/46-one-dimension-collision-js-model http://iwant2study.org/ospsg/index.php/interactive-resources/physics/02-newtonian-mechanics/02-dynamics/195-elastic-collisionComment: 6 pages, 8 figures, 1 table, 1 L. K. Wee, Physics Education 47 (3), 301 (2012); ISSN 0031-912

Anthropogenic events and responses to environmental stress are shaping the genomes of Ethiopian indigenous goats

Anthropological and biophysical processes have shaped livestock genomes over Millenia and can explain their current geographic distribution and genetic divergence. We analyzed 57 Ethiopian indigenous domestic goat genomes alongside 67 equivalents of east, west, and north-west African, European, South Asian, Middle East, and wild Bezoar goats. Cluster, ADMIXTURE (K = 4) and phylogenetic analysis revealed four genetic groups comprising African, European, South Asian, and wild Bezoar goats. The Middle Eastern goats had an admixed genome of these four genetic groups. At K = 5, the West African Dwarf and Moroccan goats were separated from East African goats demonstrating a likely historical legacy of goat arrival and dispersal into Africa via the coastal Mediterranean Sea and the Horn of Africa. FST, XP-EHH, and Hp analysis revealed signatures of selection in Ethiopian goats overlaying genes for thermo-sensitivity, oxidative stress response, high-altitude hypoxic adaptation, reproductive fitness, pathogen defence, immunity, pigmentation, DNA repair, modulation of renal function and integrated fluid and electrolyte homeostasis. Notable examples include TRPV1 (a nociception gene); PTPMT1 (a critical hypoxia survival gene); RETREG (a regulator of reticulophagy during starvation), and WNK4 (a molecular switch for osmoregulation). These results suggest that human-mediated translocations and adaptation to contrasting environments are shaping indigenous African goat genomes.</p

Anthropogenic events and responses to environmental stress are shaping the genomes of Ethiopian indigenous goats

Anthropological and biophysical processes have shaped livestock genomes over Millenia and can explain their current geographic distribution and genetic divergence. We analyzed 57 Ethiopian indigenous domestic goat genomes alongside 67 equivalents of east, west, and north-west African, European, South Asian, Middle East, and wild Bezoar goats. Cluster, ADMIXTURE (K = 4) and phylogenetic analysis revealed four genetic groups comprising African, European, South Asian, and wild Bezoar goats. The Middle Eastern goats had an admixed genome of these four genetic groups. At K = 5, the West African Dwarf and Moroccan goats were separated from East African goats demonstrating a likely historical legacy of goat arrival and dispersal into Africa via the coastal Mediterranean Sea and the Horn of Africa. FST, XP-EHH, and Hp analysis revealed signatures of selection in Ethiopian goats overlaying genes for thermo-sensitivity, oxidative stress response, high-altitude hypoxic adaptation, reproductive fitness, pathogen defence, immunity, pigmentation, DNA repair, modulation of renal function and integrated fluid and electrolyte homeostasis. Notable examples include TRPV1 (a nociception gene); PTPMT1 (a critical hypoxia survival gene); RETREG (a regulator of reticulophagy during starvation), and WNK4 (a molecular switch for osmoregulation). These results suggest that human-mediated translocations and adaptation to contrasting environments are shaping indigenous African goat genomes.</p

Anthropogenic events and responses to environmental stress are shaping the genomes of Ethiopian indigenous goats

Anthropological and biophysical processes have shaped livestock genomes over Millenia and can explain their current geographic distribution and genetic divergence. We analyzed 57 Ethiopian indigenous domestic goat genomes alongside 67 equivalents of east, west, and north-west African, European, South Asian, Middle East, and wild Bezoar goats. Cluster, ADMIXTURE (K = 4) and phylogenetic analysis revealed four genetic groups comprising African, European, South Asian, and wild Bezoar goats. The Middle Eastern goats had an admixed genome of these four genetic groups. At K = 5, the West African Dwarf and Moroccan goats were separated from East African goats demonstrating a likely historical legacy of goat arrival and dispersal into Africa via the coastal Mediterranean Sea and the Horn of Africa. FST, XP-EHH, and Hp analysis revealed signatures of selection in Ethiopian goats overlaying genes for thermo-sensitivity, oxidative stress response, high-altitude hypoxic adaptation, reproductive fitness, pathogen defence, immunity, pigmentation, DNA repair, modulation of renal function and integrated fluid and electrolyte homeostasis. Notable examples include TRPV1 (a nociception gene); PTPMT1 (a critical hypoxia survival gene); RETREG (a regulator of reticulophagy during starvation), and WNK4 (a molecular switch for osmoregulation). These results suggest that human-mediated translocations and adaptation to contrasting environments are shaping indigenous African goat genomes.</p

Determinants of the accuracy of rapid diagnostic tests in malaria case management: evidence from low and moderate transmission settings in the East African highlands

BACKGROUND: The accuracy of malaria diagnosis has received renewed interest in recent years due to changes in treatment policies in favour of relatively high-cost artemisinin-based combination therapies. The use of rapid diagnostic tests (RDTs) based on histidine-rich protein 2 (HRP2) synthesized by Plasmodium falciparum has been widely advocated to save costs and to minimize inappropriate treatment of non-malarial febrile illnesses. HRP2-based RDTs are highly sensitive and stable; however, their specificity is a cause for concern, particularly in areas of intense malaria transmission due to persistence of HRP2 antigens from previous infections. METHODS: In this study, 78,454 clinically diagnosed malaria patients were tested using HRP2-based RDTs over a period of approximately four years in four highland sites in Kenya and Uganda representing hypoendemic to mesoendemic settings. In addition, the utility of the tests was evaluated in comparison with expert microscopy for disease management in 2,241 subjects in two sites with different endemicity levels over four months. RESULTS: RDT positivity rates varied by season and year, indicating temporal changes in accuracy of clinical diagnosis. Compared to expert microscopy, the sensitivity, specificity, positive predictive value and negative predictive value of the RDTs in a hypoendemic site were 90.0%, 99.9%, 90.0% and 99.9%, respectively. Corresponding measures at a mesoendemic site were 91.0%, 65.0%, 71.6% and 88.1%. Although sensitivities at the two sites were broadly comparable, levels of specificity varied considerably between the sites as well as according to month of test, age of patient, and presence or absence of fever during consultation. Specificity was relatively high in older age groups and increased towards the end of the transmission season, indicating the role played by anti-HRP2 antibodies. Patients with high parasite densities were more likely to test positive with RDTs than those with low density infections. CONCLUSION: RDTs may be effective when used in low endemicity situations, but high false positive error rates may occur in areas with moderately high transmission. Reports on specificity of RDTs and cost-effectiveness analyses on their use should be interpreted with caution as there may be wide variations in these measurements depending upon endemicity, season and the age group of patients studied