Estimating national poverty rates and their effect on mortality: 129 countries, 1990–2013

AbstractBackgroundA country's wealth is an established predictor of population health outcomes. The distribution of wealth within a country is also associated with health outcomes, yet the relation between poverty and health outcomes has not been as widely assessed in cross-country studies because of insufficient data. In this study, we construct 22 complete, yet distinct, poverty data series and test how poverty can explain variation in health.MethodsThe World Bank's International Comparison Program estimates the number of people living at or below US$1·25 per day using more than 800 household surveys. However, this data series is far from complete. We build from the World Bank dataset and use covariates and intertemporal trends to generate a complete data series for 129 countries for 1990–2013. We used a variable selection process based on linear regression and Bayesian model selection to derive a tractable set of predictors. To predict national poverty rates at 51 different income thresholds, we used 20 variants of three models and relied on out-of-sample validation to choose the best model. Finally, we use fixed-effects linear regression techniques to test how national poverty rates are associated with changes in adult and child mortality.FindingsA three-stage model based on multiple imputation, hierarchical random-effects estimation, and Gaussian process regression out performs all other methods used to estimate national poverty rates. We noted that the number of people living on$1·25 per day is being reduced in most parts of the world, although in some regions of Africa the extreme poverty count is increasing. When poverty is defined as living on $5·00 per day, we see that the number of people living in poverty is increasing in 88 countries (68·2$1·25 per day, is not sufficient to produce great improvements in population health. When poverty is redefined at a larger income threshold, reductions in national poverty rates predict more substantial population health gains.InterpretationSince 1990, there has been a great deal of progress made in reducing the number of people living at or below $1·25 per day. We provide evidence that increasing an individual's income above$1·25 is not associated with dramatically improved health. Instead, an income closer to $5·00 per day seems to be more closely associated with improved population health. This research highlights that, while reducing the number of people living at or below$1·25 per day is important for better health outcomes, more income is required for substantial improvements in population health.FundingThe Bill and Melinda Gates Foundation

Propagation of a Solitary Fission Wave

Reaction-diffusion phenomena are encountered in an astonishing array of natural systems. Under the right conditions, self stabilizing reaction waves can arise that will propagate at constant velocity. Numerical studies have shown that fission waves of this type are also possible and that they exhibit soliton like properties. Here, we derive the conditions required for a solitary fission wave to propagate at constant velocity. The results place strict conditions on the shapes of the flux, diffusive, and reactive profiles that would be required for such a phenomenon to persist, and this condition would apply to other reaction diffusion phenomena as well. Numerical simulations are used to confirm the results and show that solitary fission waves fall into a bistable class of reaction diffusion phenomena. (C) 2012 American Institute of Physics. [http://dx.doi.org/10.1063/1.4729927]United States Nuclear Regulatory Commission NRC-38-08-946Mechanical Engineerin

Moving beyond physical education subject knowledge to develop knowledgeable teachers of the subject

All knowledge is socially constructed, including physical education teachers’ knowledge of their subject. It is acquired from other people either formally and deliberately (e.g. by being taught) or informally and casually (e.g. by interacting with physical education teachers or playing in a sports team). The social aspects of learning appear to be particularly strong in physical education. This has implications for the development of knowledge for teaching, with trainee teachers focusing on the development of subject, and particularly content, knowledge. Focusing on subject knowledge reinforces a traditional view of physical education as it is, not as it might be to meet the needs of young people today. It is argued that attention needs to be given not only to the knowledge, skills and competencies that trainee teachers ought to develop but also to the social aspects of their learning and development and the context in which they learn. Attention also needs to be given to how the ability to think critically can be developed so that trainee teachers can become reflective practitioners able to challenge and, where appropriate, change the teaching of the subject. Only by doing this can the particularly strong socialisation which shapes the values and beliefs of physical education teachers begin to be challenged. However, as the process of developing knowledgeable teachers is ongoing it is also necessary to look beyond teacher training to continuing professional development

Moving beyond physical education subject knowledge to develop knowledgeable teachers of the subject

All knowledge is socially constructed, including physical education teachers’ knowledge of their subject. It is acquired from other people either formally and deliberately (e.g. by being taught) or informally and casually (e.g. by interacting with physical education teachers or playing in a sports team). The social aspects of learning appear to be particularly strong in physical education. This has implications for the development of knowledge for teaching, with trainee teachers focusing on the development of subject, and particularly content, knowledge. Focusing on subject knowledge reinforces a traditional view of physical education as it is, not as it might be to meet the needs of young people today. It is argued that attention needs to be given not only to the knowledge, skills and competencies that trainee teachers ought to develop but also to the social aspects of their learning and development and the context in which they learn. Attention also needs to be given to how the ability to think critically can be developed so that trainee teachers can become reflective practitioners able to challenge and, where appropriate, change the teaching of the subject. Only by doing this can the particularly strong socialisation which shapes the values and beliefs of physical education teachers begin to be challenged. However, as the process of developing knowledgeable teachers is ongoing it is also necessary to look beyond teacher training to continuing professional development

Large genomic rearrangements in the CFTR gene contribute to CBAVD

<p>Abstract</p> <p>Background</p> <p>By performing extensive scanning of whole coding and flanking sequences of the <it>CFTR (Cystic Fibrosis Transmembrane Conductance Regulator</it>) gene, we had previously identified point mutations in 167 out of 182 (91.7%) males with isolated congenital bilateral absence of the vas deferens (CBAVD). Conventional PCR-based methods of mutation analysis do not detect gross DNA lesions. In this study, we looked for large rearrangements within the whole <it>CFTR </it>locus in the 32 CBAVD patients with only one or no mutation.</p> <p>Methods</p> <p>We developed a semi-quantitative fluorescent PCR assay (SQF-PCR), which relies on the comparison of the fluorescent profiles of multiplex PCR fragments obtained from different DNA samples. We confirmed the gross alterations by junction fragment amplification and identified their breakpoints by direct sequencing.</p> <p>Results</p> <p>We detected two large genomic heterozygous deletions, one encompassing exon 2 (c.54-5811_c.164+2186del8108ins182) [or <it>CFTRdele2</it>], the other removing exons 22 to 24 (c.3964-3890_c.4443+3143del9454ins5) [or <it>CFTRdele 22_24</it>], in two males carrying a typical CBAVD mutation on the other parental <it>CFTR </it>allele. We present the first bioinformatic tool for exon phasing of the <it>CFTR </it>gene, which can help to rename the exons and the nomenclature of small mutations according to international recommendations and to predict the consequence of large rearrangements on the open reading frame.</p> <p>Conclusion</p> <p>Identification of large rearrangements further expands the <it>CFTR </it>mutational spectrum in CBAVD and should now be systematically investigated. We have designed a simple test to specifically detect the presence or absence of the two rearrangements identified in this study.</p

CXCR4/CXCL12 expression and signalling in kidney cancer

CXCL12 (SDF-1), a CXC-chemokine, and its specific receptor, CXCR4, have recently been shown to be involved in tumourgenesis, proliferation and angiogenesis. Therefore, we analysed CXCL12α/CXCR4 expression and function in four human kidney cancer cell lines (A-498, CAKI-1, CAKI-2, HA-7), 10 freshly harvested human tumour samples and corresponding normal kidney tissue. While none of the analysed tumour cell lines expressed CXCL12α, A-498 cells were found to express CXCR4. More importantly, real-time RT–PCR analysis of 10 tumour samples and respective adjacent normal kidney tissue disclosed a distinct and divergent downregulation of CXCL12α and upregulation of CXCR4 in primary tumour tissue. To prove that the CXCR4 protein is functionally active, rhCXCL12α was investigated for its ability to induce changes of intracellular calcium levels in A-498 cells. Moreover, we used cDNA expression arrays to evaluate the biological influence of CXCL12α. Comparing gene expression profiles in rhCXCL12α stimulated vs unstimulated A-498 kidney cancer cells revealed specific regulation of 31 out of 1176 genes tested on a selected human cancer array, with a prominent stimulation of genes involved in cell-cycle regulation and apoptosis. The genetic changes reported here should provide new insights into the developmental paths leading to tumour progression and may also aid the design of new approaches to therapeutic intervention

Aphids acquired symbiotic genes via lateral gene transfer

<p>Abstract</p> <p>Background</p> <p>Aphids possess bacteriocytes, which are cells specifically differentiated to harbour the obligate mutualist <it>Buchnera aphidicola </it>(γ-Proteobacteria). <it>Buchnera </it>has lost many of the genes that appear to be essential for bacterial life. From the bacteriocyte of the pea aphid <it>Acyrthosiphon pisum</it>, we previously identified two clusters of expressed sequence tags that display similarity only to bacterial genes. Southern blot analysis demonstrated that they are encoded in the aphid genome. In this study, in order to assess the possibility of lateral gene transfer, we determined the full-length sequences of these transcripts, and performed detailed structural and phylogenetic analyses. We further examined their expression levels in the bacteriocyte using real-time quantitative RT-PCR.</p> <p>Results</p> <p>Sequence similarity searches demonstrated that these fully sequenced transcripts are significantly similar to the bacterial genes <it>ldcA </it>(product, LD-carboxypeptidase) and <it>rlpA </it>(product, rare lipoprotein A), respectively. <it>Buchnera </it>lacks these genes, whereas many other bacteria, including <it>Escherichia coli</it>, a close relative of <it>Buchnera</it>, possess both <it>ldcA </it>and <it>rlpA</it>. Molecular phylogenetic analysis clearly demonstrated that the aphid <it>ldcA </it>was derived from a rickettsial bacterium closely related to the extant <it>Wolbachia </it>spp. (α-Proteobacteria, Rickettsiales), which are intracellular symbionts of various lineages of arthropods. The evolutionary origin of <it>rlpA </it>was not fully resolved, but it was clearly demonstrated that its double-ψ β-barrel domain is of bacterial origin. Real-time quantitative RT-PCR demonstrated that <it>ldcA </it>and <it>rlpA </it>are expressed 11.6 and 154-fold higher in the bacteriocyte than in the whole body, respectively. LdcA is an enzyme required for recycling murein (peptidoglycan), which is a component of the bacterial cell wall. As <it>Buchnera </it>possesses a cell wall composed of murein but lacks <it>ldcA</it>, a high level of expression of the aphid <it>ldcA </it>in the bacteriocyte may be essential to maintain <it>Buchnera</it>. Although the function of RlpA is not well known, conspicuous up-regulation of the aphid <it>rlpA </it>in the bacteriocyte implies that this gene is also essential for <it>Buchnera</it>.</p> <p>Conclusion</p> <p>In this study, we obtained several lines of evidence indicating that aphids acquired genes from bacteria via lateral gene transfer and that these genes are used to maintain the obligately mutualistic bacterium, <it>Buchnera</it>.</p