898 research outputs found

    Census politics in deeply divided societies

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    Population censuses in societies that are deeply divided along ethnic, religious or linguistic lines can be sensitive affairs – particularly where political settlements seek to maintain peace through the proportional sharing of power between groups. This brief sets out some key findings from a research project investigating the relationship between census politics and the design of political institutions in Bosnia and Herzegovina, Kenya, Lebanon and Northern Ireland

    Are youth mentoring programs good value-for-money? An evaluation of the Big Brothers Big Sisters Melbourne Program

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    Background : The Big Brothers Big Sisters (BBBS) program matches vulnerable young people with a trained, supervised adult volunteer as mentor. The young people are typically seriously disadvantaged, with multiple psychosocial problems.Methods : Threshold analysis was undertaken to determine whether investment in the program was a worthwhile use of limited public funds. The potential cost savings were based on US estimates of life-time costs associated with high-risk youth who drop out-of-school and become adult criminals. The intervention was modelled for children aged 10&ndash;14 years residing in Melbourne in 2004.Results : If the program serviced 2,208 of the most vulnerable young people, it would cost AUD 39.5 M. Assuming 50% were high-risk, the associated costs of their adult criminality would be AUD 3.3 billion. To break even, the program would need to avert high-risk behaviours in only 1.3% (14/1,104) of participants.Conclusion : This indicative evaluation suggests that the BBBS program represents excellent \u27value for money\u27.<br /

    Pyrite-induced hydroxyl radical formation and its effect on nucleic acids

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    BACKGROUND: Pyrite, the most abundant metal sulphide on Earth, is known to spontaneously form hydrogen peroxide when exposed to water. In this study the hypothesis that pyrite-induced hydrogen peroxide is transformed to hydroxyl radicals is tested. RESULTS: Using a combination of electron spin resonance (ESR) spin-trapping techniques and scavenging reactions involving nucleic acids, the formation of hydroxyl radicals in pyrite/aqueous suspensions is demonstrated. The addition of EDTA to pyrite slurries inhibits the hydrogen peroxide-to-hydroxyl radical conversion, but does not inhibit the formation of hydrogen peroxide. Given the stability of EDTA chelation with both ferrous and ferric iron, this suggests that the addition of the EDTA prevents the transformation by chelation of dissolved iron species. CONCLUSION: While the exact mechanism or mechanisms of the hydrogen peroxide-to-hydroxyl radical conversion cannot be resolved on the basis of the experiments reported in this study, it is clear that the pyrite surface promotes the reaction. The formation of hydroxyl radicals is significant because they react nearly instantaneously with most organic molecules. This suggests that the presence of pyrite in natural, engineered, or physiological aqueous systems may induce the transformation of a wide range of organic molecules. This finding has implications for the role pyrite may play in aquatic environments and raises the question whether inhalation of pyrite dust contributes to the development of lung diseases

    Molecular evolution of HoxA13 and the multiple origins of limbless morphologies in amphibians and reptiles

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    Developmental processes and their results, morphological characters, are inherited through transmission of genes regulating development. While there is ample evidence that cis-regulatory elements tend to be modular, with sequence segments dedicated to different roles, the situation for proteins is less clear, being particularly complex for transcription factors with multiple functions. Some motifs mediating protein-protein interactions may be exclusive to particular developmental roles, but it is also possible that motifs are mostly shared among different processes. Here we focus on HoxA13, a protein essential for limb development. We asked whether the HoxA13 amino acid sequence evolved similarly in three limbless clades: Gymnophiona, Amphisbaenia and Serpentes. We explored variation in ω (dN/dS) using a maximum-likelihood framework and HoxA13sequences from 47 species. Comparisons of evolutionary models provided low ω global values and no evidence that HoxA13 experienced relaxed selection in limbless clades. Branch-site models failed to detect evidence for positive selection acting on any site along branches of Amphisbaena and Gymnophiona, while three sites were identified in Serpentes. Examination of alignments did not reveal consistent sequence differences between limbed and limbless species. We conclude that HoxA13 has no modules exclusive to limb development, which may be explained by its involvement in multiple developmental processes

    Transmission Pattern of Drug-Resistant Tuberculosis and Its Implication for Tuberculosis Control in Eastern Rural China

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    OBJECTIVE: Transmission patterns of drug-resistant Mycobacterium tuberculosis (MTB) may be influenced by differences in socio-demographics, local tuberculosis (TB) endemicity and efficaciousness of TB control programs. This study aimed to investigate the impact of DOTS on the transmission of drug-resistant TB in eastern rural China. METHODS: We conducted a cross-sectional study of all patients diagnosed with drug-resistant TB over a one-year period in two rural Chinese counties with varying lengths of DOTS implementation. Counties included Deqing, with over 11 years' DOTS implementation and Guanyun, where DOTS was introduced 1 year prior to start of this study. We combined demographic, clinical and epidemiologic information with IS6110-based restricted fragment length polymorphism (RFLP) and Spoligotyping analysis of MTB isolates. In addition, we conducted DNA sequencing of resistance determining regions to first-line anti-tuberculosis agents. RESULTS: Of the 223 drug-resistant isolates, 73(32.7%) isolates were identified with clustered IS6110RFLP patterns. The clustering proportion among total drug-resistant TB was higher in Guanyun than Deqing (26/101.vs.47/122; p,0.04), but not significantly different among the 53 multidrug-resistant isolates (10/18.vs.24/35; p,0.35). Patients with cavitary had increased risk of clustering in both counties. In Guanyun, patients with positive smear test or previous treatment history had a higher clustering proportion. Beijing genotype and isolates resistant to isoniazid and/or rifampicin were more likely to be clustered. Of the 73 patients with clustered drug-resistant isolates, 71.2% lived in the same or neighboring villages. Epidemiological link (household and social contact) was confirmed in 12.3% of the clustered isolates. CONCLUSION: Transmission of drug-resistant TB in eastern rural China is characterized by small clusters and limited geographic spread. Our observations highlight the need for supplementing DOTS with additional strategies, including active case finding at the village level, effective treatment for patients with cavities and drug susceptibility testing for patients at increased risk for drug-resistance

    Efficient Finite Groups Arising in the Study of Relative Asphericity

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    We study a class of two-generator two-relator groups, denoted Jn(m, k), that arise in the study of relative asphericity as groups satisfying a transitional curvature condition. Particular instances of these groups occur in the literature as finite groups of intriguing orders. Here we find infinite families of non-elementary virtually free groups and of finite metabelian non-nilpotent groups, for which we determine the orders. All Mersenne primes arise as factors of the orders of the non-metacyclic groups in the class, as do all primes from other conjecturally infinite families of primes. We classify the finite groups up to isomorphism and show that our class overlaps and extends a class of groups Fa,b,c with trivalent Cayley graphs that was introduced by C.M.Campbell, H.S.M.Coxeter, and E.F.Robertson. The theory of cyclically presented groups informs our methods and we extend part of this theory (namely, on connections with polynomial resultants) to ?bicyclically presented groups? that arise naturally in our analysis. As a corollary to our main results we obtain new infinite families of finite metacyclic generalized Fibonacci groups

    German ambulatory care physicians' perspectives on clinical guidelines – a national survey

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    BACKGROUND: There has been little systematic research about the extent to which German physicians accept or reject the concept and practice of a) clinical practice guidelines (CPG) and b) evidence based medicine (EBM) The aim of this study was to investigate German office-based physicians' perspective on CPGs and EBM and their application in medical practice. METHODS: Structured national telephone survey of ambulatory care physicians, four thematic blocks with 21 questions (5 point Likert scale). 511 office-based general practitioners and specialists. Main outcome measures were the application of Clinical Practice Guidelines in daily practice, preference for sources of guidelines and degree of knowledge and acceptance of EBM. In the data analysis Pearson's correlation coefficient was used for explorative analysis of correlations. The comparison of groups was performed by Student's t-test. Chi(2 )test was used to investigate distribution of two or more categorical variables. RESULTS: Of the total study population 55.3% of physicians reported already using guidelines in the treatment of patients. Physicians in group practices (GrP) as well as general practitioners (GP) agreed significantly more with the usefulness of guidelines as a basis for patient care than doctors in single practices (SP) or specialists (S) (Student's t-test mean GP 2.57, S 2.84, p < 0.01; mean GrP 2.55, SP 2.80, p < 0.05). 33.1% of the participants demonstrated a strong rejection to the application of guidelines in patient care. Acceptance of guidelines from a governmental institution was substantially lower than from physician networks or medical societies (36.2% vs. 53.4% vs. 62.0%). 73.8% of doctors interpret EBM as a combination of scientific research and individual medical knowledge; 80% regard EBM as the best basis for patient care. CONCLUSION: Despite a majority of physicians accepting and applying CPGs a large group remains that is critical and opposed to the utilization of CPGs in daily practice and to the concept of EBM in general. Doctors in single practice and specialists appear to be more critical than physicians in group practices and GPs. Future research is needed to evaluate the willingness to acquire necessary knowledge and skills for the promotion and routine application of CPGs
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