Clinical malaria case definition and malaria attributable fraction in the highlands of western Kenya.

BackgroundIn African highland areas where endemicity of malaria varies greatly according to altitude and topography, parasitaemia accompanied by fever may not be sufficient to define an episode of clinical malaria in endemic areas. To evaluate the effectiveness of malaria interventions, age-specific case definitions of clinical malaria needs to be determined. Cases of clinical malaria through active case surveillance were quantified in a highland area in Kenya and defined clinical malaria for different age groups.MethodsA cohort of over 1,800 participants from all age groups was selected randomly from over 350 houses in 10 villages stratified by topography and followed for two-and-a-half years. Participants were visited every two weeks and screened for clinical malaria, defined as an individual with malaria-related symptoms (fever [axillary temperature≥37.5°C], chills, severe malaise, headache or vomiting) at the time of examination or 1-2 days prior to the examination in the presence of a Plasmodium falciparum positive blood smear. Individuals in the same cohort were screened for asymptomatic malaria infection during the low and high malaria transmission seasons. Parasite densities and temperature were used to define clinical malaria by age in the population. The proportion of fevers attributable to malaria was calculated using logistic regression models.ResultsIncidence of clinical malaria was highest in valley bottom population (5.0% cases per 1,000 population per year) compared to mid-hill (2.2% cases per 1,000 population per year) and up-hill (1.1% cases per 1,000 population per year) populations. The optimum cut-off parasite densities through the determination of the sensitivity and specificity showed that in children less than five years of age, 500 parasites per μl of blood could be used to define the malaria attributable fever cases for this age group. In children between the ages of 5-14, a parasite density of 1,000 parasites per μl of blood could be used to define the malaria attributable fever cases. For individuals older than 14 years, the cut-off parasite density was 3,000 parasites per μl of blood.ConclusionClinical malaria case definitions are affected by age and endemicity, which needs to be taken into consideration during evaluation of interventions

Epidemiological risk factors for clinical malaria infection in the highlands of Western Kenya.

BackgroundUnderstanding the complex heterogeneity of risk factors that can contribute to an increased risk of malaria at the individual and household level will enable more effective use of control measures. The objective of this study was to understand individual and household factors that influence clinical malaria infection among individuals in the highlands of Western Kenya.MethodsThis was a matched case-control study undertaken in the Western Kenya highlands. Clinical malaria cases were recruited from health facilities and matched to asymptomatic individuals from the community who served as controls. Each participant was screened for malaria using microscopy. Follow-up surveys were conducted with individual households to collect socio-economic data. The houses were also checked using pyrethrum spray catches to collect mosquitoes.ResultsA total of 302 malaria cases were matched to 604 controls during the surveillance period. Mosquito densities were similar in the houses of both groups. A greater percentage of people in the control group (64.6%) used insecticide-treated bed nets (ITNs) compared to the families of malaria cases (48.3%). Use of ITNs was associated with lower level of clinical malaria episodes (odds ratio 0.51; 95% CI 0.39-0.68; P < 0.0001). Low income was the most important factor associated with higher malaria infections (adj. OR 4.70). Use of malaria prophylaxis was the most important factor associated with less malaria infections (adj OR 0.36). Mother's (not fathers) employment status (adj OR 0.48) and education level (adj OR 0.54) was important malaria risk factor. Houses with open eaves was an important malaria risk factor (adj OR 1.72).ConclusionThe identification of risk factors for clinical malaria infection provides information on the local malaria epidemiology and has the potential to lead to a more effective and targeted use of malaria control measures. These risk factors could be used to assess why some individuals acquire clinical malaria whilst others do not and to inform how intervention could be scaled at the local level

Defects in Self Assembled Colloidal Crystals

Colloidal self assembly is an efficient method for making 3-D ordered nanostructures suitable for materials such as photonic crystals and macroscopic solids for catalysis and sensor applications. Colloidal crystals grown by convective methods exhibit defects on two different scales. Macro defects such as cracks and void bands originate from the dynamics of meniscus motion during colloidal crystal growth while micro defects like vacancies, dislocation and stacking faults are indigenous to the colloidal crystalline structure. This paper analyses the crystallography and energetics of the microscopic defects from the point of view of classical thermodynamics and discusses the strategy for the control of the macroscopic defects through optimization of the liquid-vapor interface.Singapore-MIT Alliance (SMA

Adaptation Strategies of Smallholder Farmers to Climate Change and Variability: Evidence from Northern Ghana

Farmers have been modifying their practices in order to deal with climate change and variability. Even though such practices have been documented in other parts of Africa, information on Ghana and particularly northern Ghana is scanty. This study examines the adaptation strategies of smallholder farmers to climate change and variability in northern Ghana. The paper is based on primary data collected through a household survey, community focus group discussions and key informant interviews in order to identify the adaptation responses of smallholder farmers in northern Ghana to climate change and variability. Several indigenous climate-related practices and technologies categorised into four strategies were identified. In addition, climate related technologies introduced by research, also categorised into four strategies, and were identified as being used by smallholder farmers in northern Ghana. The empirical results of the Friedman test indicates that timing of the onset of the rainy season which informed planting, and soil and plant health related strategies are the most important climate related strategies used by smallholder farmers in securing yield. The policy implication is that practical, timely and reliable information on the onset of the rainy season as well as region specific soil and plant health technologies should be generated and made available to smallholder farmers in northern Ghana to minimise the adverse impacts of climate change

Gelsolin induces colorectal tumor cell invasion via modulation of the urokinase-type plasminogen activator cascade

Gelsolin is a cytoskeletal protein which participates in actin filament dynamics and promotes cell motility and plasticity. Although initially regarded as a tumor suppressor, gelsolin expression in certain tumors correlates with poor prognosis and therapy-resistance. In vitro, gelsolin has anti-apoptotic and pro-migratory functions and is critical for invasion of some types of tumor cells. We found that gelsolin was highly expressed at tumor borders infiltrating into adjacent liver tissues, as examined by immunohistochemistry. Although gelsolin contributes to lamellipodia formation in migrating cells, the mechanisms by which it induces tumor invasion are unclear. Gelsolin’s influence on the invasive activity of colorectal cancer cells was investigated using overexpression and small interfering RNA knockdown. We show that gelsolin is required for invasion of colorectal cancer cells through matrigel. Microarray analysis and quantitative PCR indicate that gelsolin overexpression induces the upregulation of invasion-promoting genes in colorectal cancer cells, including the matrix-degrading urokinase-type plasminogen activator (uPA). Conversely, gelsolin knockdown reduces uPA levels, as well as uPA secretion. The enhanced invasiveness of gelsolin-overexpressing cells was attenuated by treatment with function-blocking antibodies to either uPA or its receptor uPAR, indicating that uPA/uPAR activity is crucial for gelsolin-dependent invasion. In summary, our data reveals novel functions of gelsolin in colorectal tumor cell invasion through its modulation of the uPA/uPAR cascade, with potentially important roles in colorectal tumor dissemination to metastatic sites

Residential Satisfaction in a Mining-Induced Displacement and Resettlement in Ghana

Housing challenges associated with Mining-Induced Displacement and Resettlement have not been examined in literature as much as relocations due to physical development projects like the construction of dams.  This study, therefore, endeavours to fill this gap by contributing to discussions on displacements and resettlements communities due to mining activities from the perspective of residential satisfaction.  A questionnaire survey was administered to 229 household-heads at Salman, a rural community in the Ellembelle District of the Western Region in Ghana, to investigate the determinants of residential satisfaction in a Mining-Induced Displacement and Resettlement. Residents’ assessed their satisfaction based on the physical features of the dwelling units, community facilities, social/neighbourhood environment, and infrastructural services.  Data were analysed using mathematical equations to attain residential satisfaction and habitability indices.  The study revealed moderate residential satisfaction with the overall resettlement housing.  Satisfaction with physical features of the dwelling units was high, while satisfaction with community facilitates and social/neighbourhood environment was moderate. The satisfaction level with infrastructure services was, however, shallow.  The study avers that there exist opportunities for real residential satisfaction after permanent mining-induced relocation of communities. Keywords: Residential satisfaction, Mining-Induced Displacement and Resettlement, Dwelling units, Community facilities, Neighbourhood. DOI: 10.7176/CER/12-9-05 Publication date:September 30th 202

Climate Change Awareness and Coping Strategies of Cocoa Farmers in Rural Ghana

The study assessed the perception of farmers on the awareness, causes and impact of climate change on their farming activities. The study further identifies and describes the various coping strategies adopted by farmers and ways of improving upon them to effectively tackle change in climatic conditions. The collected data were analyzed using descriptive statistics, such as frequencies, and percentages. The other key technique that was employed to address the objective includes the Chi square analysis. The findings indicates that, the ( ) calculated (25.846) is greater than critical (18.307); implying that, respondents (cocoa farmers) in all the cocoa growing regions in the country are much aware of climate change and its impact on their farming activities ranging from the time of planting cocoa to the time of harvesting and drying cocoa beans. Main causes of climate change by farmers’ perception include God’s plan signifying the end of time, usage of heavy machines on land, air and water, deforestation, indiscriminate bush burning before farming or in search of game, farming alongside river bodies and illegal mining. Amongst the coping strategies identified include the soil fertility strategy, shade management strategy, land preparation strategy, farm size strategy and lining and pegging strategy.  It evident that the existing agencies and government bodies have not been responsive enough in addressing the climatic problems, forecasting skills and opportunities facing cocoa farmers as crucial factors of risk posed by climate change. The study advocates that government and stakeholders should put up educational programmes tailored to meet the climatic information needs of farmers especially the causes to enable them cope with the emerging challenges to enhance their production. This could be realized through effective extension services. Keywords: Cocoa Farmers, Climate Change, Chi square, Coping strategies, Rural Ghana.

The influence of substrate roughness, patterning, curvature, and compliance in peeling problems

NMP is supported by the European Commission under the Graphene FET Flagship (WP14 'Polymer composites' No. 604391) and FET Proactive 'Neurofibres' grant No. 732344. FB is supported by 'Neurofibres' grant No. 732344