Tobacco use and the Cardiovascular Disease Epidemic in\ud Developing Countries: Prevention Opportunity

Cardiovascular diseases remain the leading cause of death in the world, far outstripping deaths due to malaria, Human Immunodeficiency Virus/Acquired Immune Deficiency Syndrome (HIV/AIDS) and tuberculosis. Approximately 80% of the 35 million deaths annually are attributable to chronic diseases and a similar proportion of the approximately 16.7 million deaths due to CVD occur in low and middle income countries. Tobacco use is one of the major avoidable causes of cardiovascular disease. Smoking is the leading cause of preventable death and is associated with an increased risk of various diseases including cardiovascular disease. The aim of this paper is to review the literature on the role of smoking on cardiovascular disease and effects of antismoking legislation on admission due to acute myocardial infarction. Research method/Methodology: PubMed and manual search strategies using the search words ‘tobacco and cardiovascular disease’ were used to identify articles published on the contribution of smoking to cardiovascular events and the effects of legislation. 798 articles were found of which 28 were found useful and 39 were found to be highly relevant for the review. Smoking has been significantly related to acute myocardial infarction (p<0•0001) with an odds ratio of 2•87 (2•36–3•48) for current vs. never, PAR 35•7% for current and former vs. never). Smoking bans have been associated with decreases in instances of acute myocardial infarction ranging from a 40% decrease found in Helena, Montana, USA to an 8% reduction seen in the State of New York. Cardiovascular diseases are a major public health challenge. Smoking plays a major role in cardiovascular pathophysiology. Therefore efforts are required to address the problem especially at preventive level. Public smoking bans are related to fewer admissions for both cardiovascular and respiratory conditions. Legislative efforts to reduce exposure to smoking are needed especially in the developing countries, where prevalence of smoking is rising

LEARNERS’ ATTITUDE IN TEACHING AND LEARNING OF KISWAHILI IN SECONDARY SCHOOLS: CHALLENGES AND STRATEGIES

Existing studies indicate that increasing effectiveness in teaching and learning positively influence performance. However, challenges may diminish effectiveness in teaching and learning leading to poor performance. The study focused on challenges in relation to learners’ attitude towards Kiswahili and the strategies for coping with the challenges in teaching of Kiswahili in public secondary schools in Hamisi Sub-county, Vihiga County, Kenya. Study population was 4,106 form four students, 139 Kiswahili teachers, 47 principals and 1 Quality Assurance and Standards Officer. Krejcie and Morgan’s (1970) formula was used to select a sample of 351 form four students and purposive sampling was used to select 42 form four teachers of Kiswahili. Saturated sampling technique was used to select 42 principals and 1 QASO. In this study, questionnaires and interview schedule were used in data collection. Quantitative data was analysed by descriptive statistics involving frequencies, means and percentages and presented on tables. Qualitative data was categorized into themes and reported in verbatim excerpts. Learners had positive attitude towards objectives and content at mean ratings of 3.02 and 2.94 respectively. However, learners had challenges in teaching methods and evaluation techniques. They had negative attitude towards teaching methods and evaluation techniques at mean ratings of 2.44 and 2.34 respectively. The main strategy for coping with these challenges was speaking Kiswahili on specific days highly applied at 3.22. Motivational speeches and rewards as well as encouraging wide reading were lowly applied at 2.45 and 2.43 respectively. Other strategies that emerged from the study were use of Kiswahili clubs, discouraging learners from listening to adulterated Kiswahili and making Kiswahili lessons interesting. In conclusions, though the overall learners’ attitude towards objectives and content is positive, they have negative attitude towards teaching methods and evaluation techniques. Schools have various strategies for coping with the challenges applied at different extents. The study recommends that schools endeavor to inculcate positive attitude among learners towards teaching methods and evaluation procedures by making them learner centered and properly guiding them in these activities. Teachers need to expose learners to a variety of teaching methods and evaluation techniques and provide timely feedback. This will make learners more enthusiastic and confident and in turn improve performance. The study findings may benefit teachers, scholars, curriculum developers, policy makers and other interested parties in understanding the challenges in relation to learners’ attitude, adopting and strengthening the strategies as well as seeking solutions to the challenges in order to improve the teaching and learning process.  Article visualizations

Common interest

SummaryOne of the West's frontline bases during the Cold War has been turned into an innovative conservation project. Nigel Williams reports

Estimating the cumulative effects of the nature-based tourism in a coastal dolphin population from southern Kenya

Due to the growth of nature-based tourism worldwide, behavioural studies are needed to assess the impact of this industry on wildlife populations and understand their short-term effect. Tourism impact on dolphin populations remain poorly documented in developing countries. This study investigates the effects of nature-based tourism on the behaviour of the Indo-Pacific bottlenose dolphins (Tursiops aduncus) in southern Kenya. We used Markov chain models to estimate transition probabilities between behavioural states in the presence and absence of tourist boats, and assess the overall behavioural budgets. Based on these data and the tourism intensity in the area, we quantified the potential tourist boat disturbance over the period 2006-2013. Our results demonstrated that tourist boat interactions affected dolphins' behavioural budgets, with a significant decrease in the overall amount of time travelling and an increase in diving. The average duration of travelling and resting decreased significantly in the presence of boats. Although the cumulative tourism exposure was not significant for the dolphin population at their current levels, these impacts should be taken into consideration with the potential tourism growth in the area. This is particularly important if tourism reaches periods of high intensity, as we have shown that these periods could have a significant impact for the species, particularly where home-range and core areas are highly overlap by this activity. Understanding the effect of human disturbance variations from previous years may help to predict the consequences on dolphin populations, towards achieving a more ecological and economic sustainability of the activity

Market arrangements used by small scale bean farmers in Kenya: What needs to change for sustainable trade volumes?

Markets and marketing of common beans ( Phaseolus vulgaris L.) is a major issue of concern to small scale farmers and other actors in the bean value chain in Kenya, particularly inconsistency in supplying sufficient volumes required for trade. This case study assessed market arrangements used by small scale farmers in the Lake Basin and Lower Eastern bean corridors of Kenya, to determine which markets work for rural producers and what changes are needed to produce and supply sufficient quantities for trade. Using exploratory research, data were collected through Focus Group Discussions with six farmer groups, representing a total of 1255 bean farmers; and key informant interviews with extension staff. The results indicated that 94% of the farmers produced beans before identifying buyers, while only 6% participated in group marketing. Though spot-market transactions with brokers and traders provided ready cash for the farmers, formal buyers were perceived to be more reliable, but difficult to find, and operated the stringent requirements, which were a barrier to entry. Based on the study findings, sustainable production and supply of sufficient volumes for trade should entail a transformation agenda at four levels of the value chain; namely intensification of production through pure stand models with greater use of certified high yielding varieties; stable price guarantees; market-driven research and extension service; and an enabling policy and business environment in the bean value chain. Further research is needed to pilot these changes in a case control study.Les march\ue9s et la commercialisation des haricots communs ( Phaseolus vulgaris L.) constituent un sujet de pr\ue9occupation majeur pour les petites entreprises les agriculteurs et d\u2019autres acteurs de la cha\ueene de valeur du haricot au Kenya, en particulier les incoh\ue9rences dans l\u2019approvisionnement volumes suffisants requis pour le commerce. Cette \ue9tude de cas a \ue9valu\ue9 les accords de march\ue9 utilis\ue9s par les petites d\u2019agriculteurs dans les couloirs de haricots kenyans du bassin du lac et du Bas-Est, afin de d\ue9terminer les les march\ue9s fonctionnent pour les producteurs ruraux et quels changements sont n\ue9cessaires pour produire et fournir suffisamment quantit\ue9s pour le commerce. \uc0 l\u2019aide de recherches exploratoires, les donn\ue9es ont \ue9t\ue9 recueillies lors de discussions de groupe avec six groupes d\u2019agriculteurs, repr\ue9sentant un total de 1255 producteurs de haricots; et entretiens avec des informateurs cl\ue9s personnel de vulgarisation. Les r\ue9sultats ont montr\ue9 que 94% des agriculteurs produisaient des haricots avant d\u2019identifier acheteurs, alors que seulement 6% ont particip\ue9 au marketing de groupe. Bien que les transactions sur le march\ue9 au comptant avec des courtiers et les commer\ue7ants fournissaient de l\u2019argent disponible aux agriculteurs, les acheteurs formels \ue9taient per\ue7us comme plus fiables, mais difficile \ue0 trouver et appliquait les exigences strictes, qui constituaient une barri\ue8re \ue0 l\u2019entr\ue9e. Bas\ue9 sur r\ue9sultats de l\u2019\ue9tude, la production durable et la fourniture de volumes suffisants pour le commerce devraient impliquer une programme de transformation \ue0 quatre niveaux de la cha\ueene de valeur; \ue0 savoir l\u2019intensification de la production par mod\ue8les de peuplements purs utilisant davantage de vari\ue9t\ue9s certifi\ue9es \ue0 haut rendement; garanties de prix stables; ax\ue9 sur le march\ue9 service de recherche et de vulgarisation; et une politique favorable et un environnement commercial dans le haricot cha\ueene de valeur. Des recherches suppl\ue9mentaires sont n\ue9cessaires pour piloter ces changements dans une \ue9tude cas-t\ue9moins

Gametocyte carriage in an era of changing malaria epidemiology: A 19-year analysis of a malaria longitudinal cohort

Background: Interventions to block malaria transmission from humans to mosquitoes are currently in development. To be successfully implemented, key populations need to be identified where the use of these transmission-blocking and/or reducing strategies will have greatest impact. Methods: We used data from a longitudinally monitored cohort of children from Kilifi county located along the Kenyan coast collected between 1998-2016 to describe the distribution and prevalence of gametocytaemia in relation to transmission intensity, time and age. Data from 2,223 children accounting for 9,134 person-years of follow-up assessed during cross-sectional surveys for asexual parasites and gametocytes were used in logistic regression models to identify factors predictive of gametocyte carriage in this cohort. Results: Our analysis showed that children 1-5 years of age were more likely to carry microscopically detectable gametocytes than their older counterparts. Carrying asexual parasites and recent episodes of clinical malaria were also strong predictors of gametocyte carriage. The prevalence of asexual parasites and of gametocyte carriage declined over time, and after 2006, when artemisinin combination therapy (ACT) was introduced, recent episodes of clinical malaria ceased to be a predictor of gametocyte carriage.  Conclusions: Gametocyte carriage in children in Kilifi has fallen over time.  Previous episodes of clinical malaria may contribute to the development of carriage, but this appears to be mitigated by the use of ACTs highlighting the impact that gametocidal antimalarials can have in reducing the overall prevalence of gametocytaemia when targeted on acute febrile illness.</ns4:p

Review of natural fibre-reinforced hybrid composites

Natural fibre-reinforced hybrid composites which contain one or more types of natural reinforcement are gaining increasing research interest. This paper presents a review of natural fibre-reinforced hybrid composites. Both thermoplastic and thermoset composites reinforced by hybrid/synthetic fibres or hybrid/hybrid fibres are reviewed. The properties of natural fibres, the properties and processing of composites are summarised

DNA Methylation

<p><b>A</b>. X Chromosome DNA Methylation and XIST Expression. Methylation levels of genes in the X-chromosome (<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0118307#pone.0118307.s009" target="_blank">S6A Table</a>) are shown on the heatmap. Hierarchical clustering was performed on the samples, as indicated by the dendrogram. The genes are ordered according to their location (from the beginning to the end of the chromosome). Samples that show loss of DNA methylation for the “Enz” cluster are highlighted in blue, those that show DNA methylation for the “Ecm” cluster are highlighted in pink, and for both clusters in mauve. Genes located in the regions of loss of DNA methylation are listed to the right of the heatmap. XIST expression is shown on the line graph, with the detection limit for the microarray indicated by the red line. <b>B</b>. DNA methylation at imprinted loci. Methylation levels for imprinted probes (<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0118307#pone.0118307.s009" target="_blank">S6B Table</a>) are shown on the heatmap. Hierarchical clustering was performed on the samples, as indicated by the dendrogram. The genes are ordered according to chromosome location; genes are listed to the left. The inset at the right shows a detail of the NESP/GNAS complex locus, indicating the positions of the CpG sites that were hypermethylated (red triangle) vs. hypomethylated (green triangle) in the late passage samples relative to the NESP/GNAS and NESPAS exons. <b>C, D, E</b>. Heatmaps showing differential DNA methylation genes for early vs. late passage <b>(C)</b>, mechanical vs. enzymatic passage <b>(D)</b>, and Mef vs. Ecm substrate <b>(E)</b>. In heatmap <b>(C)</b>, the black boxes indicate genes for which the DNA methylation levels in the late passage MefMech (P103) samples was more similar to those in the early passage samples. Probes were selected by multivariate regression. Functional enrichments identified by GREAT analysis are shown to the right of the heatmaps, visualized using REVIGO [<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0118307#pone.0118307.ref013" target="_blank">13</a>]. Samples were arranged according to passage and culture method, and hierarchical clustering was performed on the genes only. In the functional enrichment results, the size of the node indicated the number of contributing GO terms, and color of the nodes indicates the FDR (darker color for lower FDR), and the edge length indicates the similarity between GO terms (shorter edge for more similar terms).</p

The ratio of monocytes to lymphocytes in peripheral blood correlates with increased susceptibility to clinical malaria in Kenyan children.

BACKGROUND: Plasmodium falciparum malaria remains a major cause of illness and death in sub-Saharan Africa. Young children bear the brunt of the disease and though older children and adults suffer relatively fewer clinical attacks, they remain susceptible to asymptomatic P. falciparum infection. A better understanding of the host factors associated with immunity to clinical malaria and the ability to sustain asymptomatic P. falciparum infection will aid the development of improved strategies for disease prevention. METHODS AND FINDINGS: Here we investigate whether full differential blood counts can predict susceptibility to clinical malaria among Kenyan children sampled at five annual cross-sectional surveys. We find that the ratio of monocytes to lymphocytes, measured in peripheral blood at the time of survey, directly correlates with risk of clinical malaria during follow-up. This association is evident among children with asymptomatic P. falciparum infection at the time the cell counts are measured (Hazard ratio (HR)  =  2.7 (95% CI 1.42, 5.01, P  =  0.002) but not in those without detectable parasitaemia (HR  =  1.0 (95% CI 0.74, 1.42, P  =  0.9). CONCLUSIONS: We propose that the monocyte to lymphocyte ratio, which is easily derived from routine full differential blood counts, reflects an individual's capacity to mount an effective immune response to P. falciparum infection