Child Centred Approach to Climate Change and Health Adaptation through Schools in Bangladesh: A Cluster Randomised Intervention Trial

Background

Bangladesh is one of the most vulnerable countries to climate change. People are getting educated at different levels on how to deal with potential impacts. One such educational mode was the preparation of a school manual, for high school students on climate change and health protection endorsed by the National Curriculum and Textbook Board, which is based on a 2008 World Health Organization manual. The objective of this study was to test the effectiveness of the manual in increasing the knowledge level of the school children about climate change and health adaptation.

Methods

This cluster randomized intervention trial involved 60 schools throughout Bangladesh, with 3293 secondary school students participating. School upazilas (sub-districts) were randomised into intervention and control groups, and two schools from each upazila were randomly selected. All year seven students from both groups of schools sat for a pre-test of 30 short questions of binary response. A total of 1515 students from 30 intervention schools received the intervention through classroom training based on the school manual and 1778 students of the 30 control schools did not get the manual but a leaflet on climate change and health issues. Six months later, a post-intervention test of the same questionnaire used in the pre-test was performed at both intervention and control schools. The pre and post test scores were analysed along with the demographic data by using random effects model.

Results

None of the various school level and student level variables were significantly different between the control and intervention group. However, the intervention group had a 17.42% (95% CI: 14.45 to 20.38, P = <0.001) higher score in the post-test after adjusting for pre-test score and other covariates in a multi-level linear regression model.

Conclusions

These results suggest that school-based intervention for climate change and health adaptation is effective for increasing the knowledge level of school children on this topic.     

From ‘cryptic species’ to integrative taxonomy: an iterative process involving DNA sequences,morphology, and behaviour leads to the resurrection of Sepsis pyrrhosoma (Sepsidae: Diptera)

Tan, D. S. H., Ang, Y., Lim, G. S., Ismail, M. R. B. & Meier, R. (2010). From ‘cryptic species’ to integrative taxonomy: an iterative process involving DNA sequences, morphology, and behaviour leads to the resurrection of Sepsis pyrrhosoma (Sepsidae: Diptera). —Zoologica Scripta, 39, 51–61. The increased availability of DNA sequences has led to a surge of ‘cryptic species’ in the literature. These units are usually proposed based on finding genetically distinct lineages within species that were initially defined based on morphological characters. However, few authors attempt to confirm whether these ‘cryptic’ units are species and even fewer authors are explicit about which species concept is applied. Here, we use an example from Sepsidae (Diptera) to demonstrate how cryptic species can be validated by an iterative process involving several data sources and an evaluation of the data under different species concepts. A phylogeographic analysis based on 50 specimens for five species of the flavimana group revealed deep mitochondrial splits within Sepsis flavimana which was suggestive of a cryptic species. We resolve the initial conflict between DNA sequences and morphology by adding new morphological data as well as behavioural evidence and tests for reproductive isolation. One cryptic species is confirmed and Sepsis pyrrhosoma, a former synonym of S. flavimana, is here shown to be a valid species under most species concepts. We can thus document that the same data can lead to similar conclusions under conflicting concepts once different kinds of data are integrated.     

Gender-dependent effects of selenite on the perfused rat heart

Gender differences are related to the manner in which the heart responds to chronic and acute stress conditions of physiological and pathological nature. Depending on dose, sodium selenite acts as an antioxidant proven to have beneficial effects in several pathological conditions G. Drasch, J. Schopfer, and G. N. Schrauzer, Selenium/cadmium ratios in human prostates: indicators of prostate cancer risk of smokers and non-smokers, and relevance to the cancer protective effects of selenium,Biol. Trace Element Res. 103(2), 103–107 (2005); R. G. Kasseroller and G. N. Schrauzer, Treatment of secondary lymphedema of the arm with physical decongestive therapy and sodium selenite: a review,Am. J. Ther. 7(4), 273–279 (2000); G. N. Schrauzer, Anticarcinogenic effects of selenium,Cell. Mol. Life Sci. 57(13–14), 1864–1873 (2000); I. S. Palmer and O. E. Olson, Relative toxicities of selenite and selenate in the drinking water of rats,J. Nutr. 104(3), 306–314 (1974). To date, little is known about the gender-dependent direct effects of toxic doses of selenite on electrophysiology of the cardiovascular system H. A. Schroeder and M. Mitchener, Selenium and tellurium in rats: effect on growth, survival and tumors,J. Nutr. 101(11), 1531–1540 (1971); G. N. Schrauzer, The nutritional significance, metabolism and toxicology of selenomethionine,Adv. Food Nutr. Res. 47, 73–112 (2003). In the present study, the effects of in vitro toxic concentrations of sodium selenite ranging from 10^-6 M to 10^-3 M were tested on both male and female rat heart preparations. The toxic effects seen in an electrocardiogram and left ventricular pressure were dose and sex dependent at most of the tested concentrations. The present study clearly shows that at toxic doses, stress conditions are induced by selenite, resulting in gender-dependent modifications of the heart function. This modification is more pronounced in the contraction cascade of female rats. Males, on the other hand, had been much more affected in excitation-related parameters.     

Structure of a complex of human lactoferrin N-lobe with pneumococcal surface protein a provides insight into microbial defense mechanism

Human lactoferrin, a component of the innate immune system, kills a wide variety of microorganisms including the Gram positive bacteria Streptococcus pneumoniae. Pneumococcal surface protein A (PspA) efficiently inhibits this bactericidal action. The crystal structure of a complex of the lactoferrin-binding domain of PspA with the N-lobe of human lactoferrin reveals direct and specific interactions between the negatively charged surface of PspA helices and the highly cationic lactoferricin moiety of lactoferrin. Binding of PspA blocks surface accessibility of this bactericidal peptide preventing it from penetrating the bacterial membrane. Results of site-directed mutagenesis, in vitro protein binding assays and isothermal titration calorimetry measurements corroborate that the specific electrostatic interactions observed in the crystal structure represent major associations between PspA and lactoferrin. The structure provides a snapshot of the protective mechanism utilized by pathogens against the host's first line of defense. PspA represents a major virulence factor and a promising vaccine candidate. Insights from the structure of the complex have implications for designing therapeutic strategies for treatment and prevention of pneumococcal diseases that remain a major public health problem worldwide.     

Progression of myocardial injury during coronary occlusion in the collateral-deficient heart: a non-wavefront phenomenon

It is widely accepted that, during acute coronary occlusion, ischemic cell death progresses from the subendocardium to the subepicardium in a wavefront fashion. This concept, which implies that the subendocardium is the most susceptible myocardial region to ischemic injury, was established using a canine model with an extensive system of subepicardial coronary collaterals. In humans, particularly in those with coronary artery disease, there is a wide range in the distribution and functional capacity of the collateral circulation, which may affect the pattern of infarct evolution. Using an ovine model with a limited system of preformed subendocardial coronary collaterals, we characterized the effect of increasing lengths of ischemia on regional blood flow and infarct size in three regions of the ventricular wall: subendocardium, midmyocardium, and subepicardium. Our results demonstrate that the myocardium and microvasculature in these three regions are equally susceptible to injury after 45 min of ischemia. When ischemic time is increased to 1 h, infarct size in the midmyocardium (90 +/- 2%) is greater than in the subendocardium (76 +/- 4%, P = 0.004) and subepicardium (84 +/- 3%, P = 0.13). Microvascular dysfunction as assessed as a percentage of baseline flow is also greater in the midmyocardium (14 +/- 5%) compared with the subendocardium (20 +/- 3%, P = 0.23) and subepicardium (51 +/- 9%, P = 0.007). These findings suggest that, in subjects with a limited system of coronary collateral circulation, the midmyocardium is the most susceptible myocardial region to ischemia and the subendocardium is the most resistant. Myocardial viability during coronary occlusion appears to be primarily determined by the distribution and functional capacity of the collateral circulation.     

Structural basis for ubiquitin-mediated dimerization and activation of the ubiquitin protein ligase Cbl-b

Cbl proteins are E3 ubiquitin ligases that are negative regulators of many receptor tyrosine kinases. Cbl-b and c-Cbl contain a ubiquitin-associated (UBA) domain, which is present in a variety of proteins involved in ubiquitin-mediated processes. Despite high sequence identity, Cbl UBA domains display remarkably different ubiquitin-binding properties. Here, we report the crystal structure of the UBA domain of Cbl-b in complex with ubiquitin at 1.9 A resolution. The structure reveals an atypical mechanism of ubiquitin recognition by the first helix of the UBA. Helices 2 and 3 of the UBA domain form a second binding surface, which mediates UBA dimerization in the crystal and in solution. Site-directed mutagenesis demonstrates that Cbl-b dimerization is regulated by ubiquitin binding and required for tyrosine phosphorylation of Cbl-b and ubiquitination of Cbl-b substrates. These studies demonstrate a role for ubiquitin in regulating biological activity by promoting protein dimerization.     

Extracellular amino acid levels in the human liver during transplantation: a microdialysis study from donor to recipient

Using microdialysis, we have monitored extracellular levels of amino acids and related amines in the human liver at three stages of the transplantation procedure: donor retrieval, back table preparation and during 48 h post-implantation. By comparing the ratio of mean levels at the donor and back table stages, with the ratio between early (2-6 h) and late (43-48 h) post-reperfusion, these amines were classified into one of three groups. In one group, back table levels were markedly higher than during the donor stage, with levels declining over time post-reperfusion. A second group had much lower levels in the back table than during the donor phase, and post-reperfusion levels were either stable or increased over time. Concentrations of amino acids in the final group remained relatively constant at all stages. This study illustrates the value of microdialysis in providing organ-specific metabolic data that may indicate specific mechanisms of poor graft function.