1,210 research outputs found

    Developing standards for household latrines in Rwanda

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    The issue of standards for household latrines is complex because discussions related to standards for latrines in literature from the water, sanitation and hygiene (WASH) sector tend to focus on the negative aspects of standards and highlights cases where the miss-application of standards in the past has caused problems. However, despite concerns about the constraints that standards can seemingly impose, there is an acknowledgement that standards can play a more positive role in supporting efforts to increase access to household latrines. The World Health Organisation has long established and widely recognised standards for water supply quality and quantity but there are no equivalent standards for sanitation services and there is currently no guidance that deals with the topic of standards for household latrines. Household latrines are a small component of the wider sanitation system in a country and by considering how standards for household latrines operate within this wider sanitation system the aim of this research is to understand what influences standards can have on household latrines and explore how the negative perceptions about standards and latrine building can be overcome. The development of guidance on how to develop well written standards is the core focus of this research. This research explores the factors that can influence the development and use of a standard for household latrines in Rwanda using three data collection methods. Document analysis using 66 documents, including policies and strategies, design manuals and training guides from 17 countries throughout Sub-Saharan Africa was used in conjunction with the Delphi Method involving an expert panel of 27 from Rwanda and 38 semi-structured interviews. The research concludes that perceptions about standards for household latrines are fragmented and confused with little consensus in Rwanda on what need a standard should meet and what role it should play. The study has found that the need for a standard must be considered in the context of the wider sanitation system otherwise it can lead to duplication of efforts and increased confusion for all stakeholders. The study also found that there is an assumed link between standards and enforcement of standards through regulation and punishments which creates the negative perceptions about standards in Rwanda. However, despite this aversion to standards, there are still intentions to promote the standardisation of latrine technologies and designs, led by national government in Rwanda and in other Sub-Saharan African countries. The contribution to knowledge of this research includes a decision process presented at the end of the study which can be used by decision makers who are interested in developing a standard for household latrines. The decision process acts as a tool for outlining how a standard can operate within the national sanitation system. This understanding provides decision makers with the basis for continuing the debate on what a well written standard looks like in the national context and supports the development of a standard that is fit for purpose and provides a positive contribution to the sector

    Vulnerability in the sanitation service chain: lessons from the SPLASH urban sanitation research programme

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    The European Union Water Initiative Research Area Network (EUWI ERA-net, or SPLASH) is a consortium of 16 organizations representing government ministries, funding agencies, national research institutions and technology development authorities from 11 European countries. The main objective of the urban sanitation research programme within SPLASH has been to contribute to the understanding and implementation of at-scale sustainable sanitation service chains in low-income urban areas of Sub-Saharan Africa. The overall findings from the SPLASH sanitation research programme can be viewed through four lenses: the enabling environment, demand creation, vulnerability in the service chain and city wide planning. This paper presents the key findings related to vulnerabilities in the sanitation service chain, which were found to relate to both internal and external vulnerabilities. With greater understanding of these vulnerabilities and how they operate within a particular city context, they can be addressed in a more systematic way as part of city-wide sanitation service improvements

    Understanding vulnerabilities and risk in the development of market based approaches

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    Progress towards resilient and sustainable development is continuous and constantly shifting as circumstances, contextual experiences and systems change. In many countries there are humanitarian and development activities taking place at the same time, yet our approaches within these areas can still be quite separated in terms of planning, implementation and monitoring. Yet traditionally quite different populations benefit from humanitarian and development interventions. Interest in the role of markets in both humanitarian and development contexts continues to grow based on the understanding that markets need to work for marginalised and vulnerable populations. Vulnerability will have an impact on the way that people can interact with market systems and trying to understand markets in relation to both personal vulnerabilities and vulnerable and fragile contexts requires a new approach, linking humanitarian and development actions more systematically

    Study of Forces During Ultrasonic Vibration Assisted Grinding

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    AbstractRadial and tangential grinding forces were presented as four components connected with workpiece material microcutting and plastic deformation, and friction of cutting and abrasive grains (AGs) with the workpiece.The depth of abrasive grain penetration in the workpiece and the cutting width are determined with regard to ultrasonic vibrations (USV) amplitude and frequency. Summing up of the forces from single grains was conducted by using a multiple integral, provided that one of the integration limits is a function describing change of the depth of the AGs penetration in the workpiece material which depends on the USV parameters. Dependencies were obtained for calculation of all grinding force components at different vibration amplitudes and frequencies when various number of USV waves fits the contact arc of the grain and the workpiece.Experimental values of grinding forces turned out to be 10 – 15% lower than those when USV waves are not applied

    Common polygenic risk for autism spectrum disorder (ASD) is associated with cognitive ability in the general population

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    Acknowledgements Generation Scotland has received core funding from the Chief Scientist Office of the Scottish Government Health Directorates CZD/16/6 and the Scottish Funding Council HR03006. We are grateful to all the families who took part, the general practitioners and the Scottish School of Primary Care for their help in recruiting them and the whole Generation Scotland team, which includes interviewers, computer and laboratory technicians, clerical workers, research scientists, volunteers, managers, receptionists, health-care assistants and nurses. We acknowledge with gratitude the financial support received for this work from the Dr Mortimer and Theresa Sackler Foundation. For the Lothian Birth Cohorts (LBC1921 and LBC1936), we thank Paul Redmond for database management assistance; Alan Gow, Martha Whiteman, Alison Pattie, Michelle Taylor, Janie Corley, Caroline Brett and Caroline Cameron for data collection and data entry; nurses and staff at the Wellcome Trust Clinical Research Facility, where blood extraction and genotyping was performed; staff at the Lothian Health Board; and the staff at the SCRE Centre, University of Glasgow. The research was supported by a program grant from Age UK (Disconnected Mind) and by grants from the Biotechnology and Biological Sciences Research Council (BBSRC). The work was undertaken by The University of Edinburgh Centre for Cognitive Ageing and Cognitive Epidemiology, part of the cross council Lifelong Health and Wellbeing Initiative (MR/K026992/1). Funding from the Medical Research Council (MRC) and BBSRC is gratefully acknowledged. DJM is an NRS Career Research Fellow funded by the CSO. BATS were funded by the Australian Research Council (A79600334, A79906588, A79801419, DP0212016, DP0664638, and DP1093900) and the National Health and Medical Research Council (389875) Australia. MKL is supported by a Perpetual Foundation Wilson Fellowship. SEM is supported by a Future Fellowship (FT110100548) from the Australian Research Council. GWM is supported by a National Health and Medical Research Council (NHMRC), Australia, Fellowship (619667). We thank the twins and siblings for their participation, Marlene Grace, Ann Eldridge and Natalie Garden for cognitive assessments, Kerrie McAloney, Daniel Park, David Smyth and Harry Beeby for research support, Anjali Henders and staff in the Molecular Epidemiology Laboratory for DNA sample processing and preparation and Scott Gordon for quality control and management of the genotypes. This work is supported by a Stragetic Award from the Wellcome Trust, reference 104036/Z/14/Z.Peer reviewedPublisher PD

    The evolutionary history of common genetic variants influencing human cortical surface area

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    Structural brain changes along the lineage leading to modern Homo sapiens contributed to our distinctive cognitive and social abilities. However, the evolutionarily relevant molecular variants impacting key aspects of neuroanatomy are largely unknown. Here, we integrate evolutionary annotations of the genome at diverse timescales with common variant associations from large-scale neuroimaging genetic screens. We find that alleles with evidence of recent positive polygenic selection over the past 2000–3000 years are associated with increased surface area (SA) of the entire cortex, as well as specific regions, including those involved in spoken language and visual processing. Therefore, polygenic selective pressures impact the structure of specific cortical areas even over relatively recent timescales. Moreover, common sequence variation within human gained enhancers active in the prenatal cortex is associated with postnatal global SA. We show that such variation modulates the function of a regulatory element of the developmentally relevant transcription factor HEY2 in human neural progenitor cells and is associated with structural changes in the inferior frontal cortex. These results indicate that non-coding genomic regions active during prenatal cortical development are involved in the evolution of human brain structure and identify novel regulatory elements and genes impacting modern human brain structure

    Psychometric precision in phenotype definition is a useful step in molecular genetic investigation of psychiatric disorders

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    Affective disorders are highly heritable, but few genetic risk variants have been consistently replicated in molecular genetic association studies. The common method of defining psychiatric phenotypes in molecular genetic research is either a summation of symptom scores or binary threshold score representing the risk of diagnosis. Psychometric latent variable methods can improve the precision of psychiatric phenotypes, especially when the data structure is not straightforward. Using data from the British 1946 birth cohort, we compared summary scores with psychometric modeling based on the General Health Questionnaire (GHQ-28) scale for affective symptoms in an association analysis of 27 candidate genes (249 single-nucleotide polymorphisms (SNPs)). The psychometric method utilized a bi-factor model that partitioned the phenotype variances into five orthogonal latent variable factors, in accordance with the multidimensional data structure of the GHQ-28 involving somatic, social, anxiety and depression domains. Results showed that, compared with the summation approach, the affective symptoms defined by the bi-factor psychometric model had a higher number of associated SNPs of larger effect sizes. These results suggest that psychometrically defined mental health phenotypes can reflect the dimensions of complex phenotypes better than summation scores, and therefore offer a useful approach in genetic association investigations

    High loading of polygenic risk for ADHD in children with comorbid aggression

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    Objective: Although attention deficit hyperactivity disorder (ADHD) is highly heritable, genome-wide association studies (GWAS) have not yet identified any common genetic variants that contribute to risk. There is evidence that aggression or conduct disorder in children with ADHD indexes higher genetic loading and clinical severity. The authors examine whether common genetic variants considered en masse as polygenic scores for ADHD are especially enriched in children with comorbid conduct disorder. Method: Polygenic scores derived from an ADHD GWAS meta-analysis were calculated in an independent ADHD sample (452 case subjects, 5,081 comparison subjects). Multivariate logistic regression analyses were employed to compare polygenic scores in the ADHD and comparison groups and test for higher scores in ADHD case subjects with comorbid conduct disorder relative to comparison subjects and relative to those without comorbid conduct disorder. Association with symptom scores was tested using linear regression. Results: Polygenic risk for ADD, derived from the meta-analysis, was higher in the independent ADHD group than in the comparison group. Polygenic score was significantly higher in ADHD case subjects with conduct disorder relative to ADHD case subjects without conduct disorder. ADHD polygenic score showed significant association with comorbid conduct disorder symptoms. This relationship was explained by,the aggression items. Conclusions: Common genetic variation is relevant to ADHD, especially in individuals with comorbid aggression. The findings suggest that the previously published ADHD GWAS meta-analysis contains weak but true associations with common variants, support for which falls below genome-wide significance levels. The findings also highlight the fact that aggression in ADHD indexes genetic as well as clinical severity

    Genetic determinants of cortical structure (thickness, surface area and volumes) among disease free adults in the CHARGE Consortium

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    Cortical thickness, surface area and volumes (MRI cortical measures) vary with age and cognitive function, and in neurological and psychiatric diseases. We examined heritability, genetic correlations and genome-wide associations of cortical measures across the whole cortex, and in 34 anatomically predefined regions. Our discovery sample comprised 22,824 individuals from 20 cohorts within the Cohorts for Heart and Aging Research in Genomic Epidemiology (CHARGE) consortium and the United Kingdom Biobank. Significant associations were replicated in the Enhancing Neuroimaging Genetics through Meta-analysis (ENIGMA) consortium, and their biological implications explored using bioinformatic annotation and pathway analyses. We identified genetic heterogeneity between cortical measures and brain regions, and 160 genome-wide significant associations pointing to wnt/β-catenin, TGF-β and sonic hedgehog pathways. There was enrichment for genes involved in anthropometric traits, hindbrain development, vascular and neurodegenerative disease and psychiatric conditions. These data are a rich resource for studies of the biological mechanisms behind cortical development and aging
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