269 research outputs found

    A pilot study of a combined energy and water hub in The Gambia Waterlines

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    Many people across the developing world live ‘off-grid’ in terms of access to mains electricity, and therefore depend upon alternative power sources to recharge their mobile phones. These recharging facilities are typically located in shops/informal businesses, and often powered by a diesel generator or solar panel. Many of these rural communities are also served by local water infrastructure that has fallen into a state of disrepair. It has been reported that many individuals are prepared to pay a small regular fee to recharge their mobile phone, whilst their wider communities may often claim to lack sufficient funds to keep their water infrastructure maintained. This paper introduces a pilot study in Gambia that combines an off-grid recharging hub with a community water point. It is proposed that a proportion of the income generated by this enterprise could be retained and used to fund the on-going maintenance costs of the recharging hub and the local water infrastructure

    A pilot study from The Gambia to improve access to water, energy, and mobile phones

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    Across Sub-Saharan Africa many communities lack reliable access to mains electricity, and therefore depend upon unconventional power sources to recharge their mobile phones. Many of these informal recharging centres are powered by a diesel generator or solar panel. Furthermore, many of these same communities are frequently served by broken water pumps. Previous reports indicate that many individuals are prepared to pay a small regular fee to recharge their mobile phone, whilst their local water point committee lacks sufficient funds to keep their water infrastructure maintained. This paper presents a novel funding strategy aimed at helping communities cover the maintenance costs of their local water supply. This premise was demonstrated using a pilot system in Gambia which combined a solar powered community water point with an off-grid smart battery rental hub for everyday electricity needs such as mobile phone charging. The paper presents preliminary field data from this site and explores the wider context surrounding the pilot system

    Field trials of a new monitoring system for water pumps in Sierra Leone and The Gambia

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    Many hand water pumps across Sub-Saharan Africa break down prematurely and remain out of service for significant periods of time. This issue has been well documented, with reports suggesting that between 20% and 65% of hand pumps in a number of African countries are broken. It has also been reported that broken hand pumps in this region have represented between 1.2and1.2 and 1.5 billion of ineffective investment over the last twenty years. Regular post-construction monitoring of remote water pumps can help address these problems. However, in many instances traditional monitoring programmes require regular site visits to remote locations, which can delay the implementation of repairs and place heavy time and resource demands on supervisory bodies. In response there has been an emerging interest in the use of mobile phone based technologies to monitor water pumps. The authors describe a new monitoring system, called MANTIS (Monitoring & ANalytics To Improve Service), which is intended to be a context-appropriate monitoring tool for hand pumps in developing regions. The paper introduces field trials of this system that have been conducted in Sierra Leone and The Gambia. The unit relays ‘near real time’ operational data from the water pump via an SMS (Short Message Service) server to an accessible on-line platform

    Field testing a remote monitoring system for hand water pumps

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    Throughout Africa, many hand water pumps malfunction and remain inoperable for long periods of time. Previous studies from a number of Sub-Saharan countries have indicated that in some regions up to 65% of hand pumps may be broken. It is reported that robust monitoring of remote water pumps can help address some of these problems. However, traditional project monitoring strategies generally rely on physical site visits to remote locations. These visits can be time consuming and resource intensive, which in turn may delay the implementation of pump repairs. In contrast, recent years have seen the emergence of a range of new monitoring technologies that use mobile phone networks to rapidly report the operational status of water projects from remote sites. The authors describe the development of a new monitoring system, called MANTIS, which is intended for hand pumps in developing regions. The paper presents data from early field trials of MANTIS in Sierra Leone and The Gambia. The unit relays ‘near real time’ operational data from the water pump to an accessible on- line platform

    Search for cardiac calcium cycling gene mutations in familial ventricular arrhythmias resembling catecholaminergic polymorphic ventricular tachycardia

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    <p>Abstract</p> <p>Background</p> <p>Catecholaminergic polymorphic ventricular tachycardia (CPVT) is a severe inherited cardiac disorder caused by mutations predominantly in the ryanodine receptor (<it>RyR2</it>) gene. We sought to identify mutations in genes affecting cardiac calcium cycling in patients with CPVT and in less typical familial exercise-related ventricular arrhythmias.</p> <p>Methods and Results</p> <p>We recruited 33 consecutive patients with frequent ventricular premature complexes (VPCs) without structural heart disease and often history of syncope or sudden death in family. Sixteen of the patients featured a phenotype typical of CPVT. In 17 patients, VPCs emerged also at rest. Exercise stress test and echocardiography were performed to each patient and 232 family members. Familial background was evident in 42% of cases (n = 14). We sequenced all the coding exons of the <it>RyR2</it>, <it>FKBP1B</it>, <it>ATP2A2 </it>and <it>SLC8A1 </it>genes from the index patients. Single channel recordings of a mutant RyR2 were performed in planar lipid bilayers. Two novel <it>RyR2 </it>missense mutations (R1051P and S616L) and two <it>RyR2 </it>exon 3 deletions were identified, explaining 25% of the CPVT phenotypes. A rare variant (N3308S) with open probabilities similar to the wild type channels <it>in vitro</it>, was evident in a patient with resting VPCs. No disease-causing variants were detectable in the <it>FKBP1B</it>, <it>ATP2A2 </it>or <it>SLC8A1 </it>genes.</p> <p>Conclusion</p> <p>We report two novel CPVT-causing <it>RyR2 </it>mutations and a novel <it>RyR2 </it>variant of uncertain clinical significance in a patient with abundant resting VPCs. Our data also strengthen the previous assumption that exon 3 deletions of <it>RyR2 </it>should screened for in CPVT and related phenotypes.</p

    Women's views and experiences of two alternative consent pathways for participation in a preterm intrapartum trial: a qualitative study

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    BACKGROUND: The Cord Pilot Trial compared alternative policies for timing of cord clamping at very preterm birth at eight UK hospitals. In addition to standard written consent, an oral assent pathway was developed for use when birth was imminent. The aim of this study was to explore women's views and experiences of two alternative consent pathways to participate in the Cord Pilot Trial. METHODS: We conducted a qualitative study using semi-structured interviews. A total of 179 participants in the Cord Pilot Trial were sent a postal invitation to take part in interviews. Women who agreed were interviewed in person or by telephone to explore their experiences of two consent pathways for a preterm intrapartum trial. Data were analysed using inductive systematic thematic analysis. RESULTS: Twenty-three women who gave either written consent (n = 18) or oral assent followed by written consent (n = 5) to participate in the trial were interviewed. Five themes were identified: (1) understanding of the implications of randomisation, (2) importance of staff offering participation, (3) information about the trial and time to consider participation, (4) trial secondary in women's minds and (5) reasons for agreeing to take part in the trial. Experiences were similar for the two consent pathways. Women recruited by the oral assent pathway reported being given less information about the trial but felt it was sufficient to make a decision regarding participation. There were gaps in women's understanding of the trial and intervention, regardless of the consent pathway. CONCLUSIONS: Overall, women were positive about their experiences of being invited to participate in the trial. The oral assent pathway seems an acceptable option for women if the intervention is low-risk and time is limited. TRIAL REGISTRATION: ISRCTN Registry, ISRCTN21456601 . Registered on 28 February 2013

    Shifting patterns of natural variation in the nuclear genome of caenorhabditis elegans

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    <p>Abstract</p> <p>Background</p> <p>Genome wide analysis of variation within a species can reveal the evolution of fundamental biological processes such as mutation, recombination, and natural selection. We compare genome wide sequence differences between two independent isolates of the nematode <it>Caenorhabditis elegans </it>(CB4856 and CB4858) and the reference genome (N2).</p> <p>Results</p> <p>The base substitution pattern when comparing N2 against CB4858 reveals a transition over transversion bias (1.32:1) that is not present in CB4856. In CB4856, there is a significant bias in the direction of base substitution. The frequency of A or T bases in N2 that are G or C bases in CB4856 outnumber the opposite frequencies for transitions as well as transversions. These differences were not observed in the N2/CB4858 comparison. Similarly, we observed a strong bias for deletions over insertions in CB4856 (1.44: 1) that is not present in CB4858. In both CB4856 and CB4858, there is a significant correlation between SNP rate and recombination rate on the autosomes but not on the X chromosome. Furthermore, we identified numerous significant hotspots of variation in the CB4856-N2 comparison.</p> <p>In both CB4856 and CB4858, based on a measure of the strength of selection (k<sub>a</sub>/k<sub>s</sub>), all the chromosomes are under negative selection and in CB4856, there is no difference in the strength of natural selection in either the autosomes versus X or between any of the chromosomes. By contrast, in CB4858, k<sub>a</sub>/k<sub>s </sub>values are smaller in the autosomes than in the X chromosome. In addition, in CB4858, k<sub>a</sub>/k<sub>s </sub>values differ between chromosomes.</p> <p>Conclusions</p> <p>The clear bias of deletions over insertions in CB4856 suggests that either the CB4856 genome is becoming smaller or the N2 genome is getting larger. We hypothesize the hotspots found represent alleles that are shared between CB4856 and CB4858 but not N2. Because the k<sub>a</sub>/k<sub>s </sub>ratio in the X chromosome is higher than the autosomes on average in CB4858, purifying selection is reduced on the X chromosome.</p

    First observations of separated atmospheric nu_mu and bar{nu-mu} events in the MINOS detector

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    The complete 5.4 kton MINOS far detector has been taking data since the beginning of August 2003 at a depth of 2070 meters water-equivalent in the Soudan mine, Minnesota. This paper presents the first MINOS observations of nuµ and [overline nu ]µ charged-current atmospheric neutrino interactions based on an exposure of 418 days. The ratio of upward- to downward-going events in the data is compared to the Monte Carlo expectation in the absence of neutrino oscillations, giving Rup/downdata/Rup/downMC=0.62-0.14+0.19(stat.)±0.02(sys.). An extended maximum likelihood analysis of the observed L/E distributions excludes the null hypothesis of no neutrino oscillations at the 98% confidence level. Using the curvature of the observed muons in the 1.3 T MINOS magnetic field nuµ and [overline nu ]µ interactions are separated. The ratio of [overline nu ]µ to nuµ events in the data is compared to the Monte Carlo expectation assuming neutrinos and antineutrinos oscillate in the same manner, giving R[overline nu ][sub mu]/nu[sub mu]data/R[overline nu ][sub mu]/nu[sub mu]MC=0.96-0.27+0.38(stat.)±0.15(sys.), where the errors are the statistical and systematic uncertainties. Although the statistics are limited, this is the first direct observation of atmospheric neutrino interactions separately for nuµ and [overline nu ]µ

    Caenorhabditis briggsae Recombinant Inbred Line Genotypes Reveal Inter-Strain Incompatibility and the Evolution of Recombination

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    The nematode Caenorhabditis briggsae is an emerging model organism that allows evolutionary comparisons with C. elegans and exploration of its own unique biological attributes. To produce a high-resolution C. briggsae recombination map, recombinant inbred lines were generated from reciprocal crosses between two strains and genotyped at over 1,000 loci. A second set of recombinant inbred lines involving a third strain was also genotyped at lower resolution. The resulting recombination maps exhibit discrete domains of high and low recombination, as in C. elegans, indicating these are a general feature of Caenorhabditis species. The proportion of a chromosome's physical size occupied by the central, low-recombination domain is highly correlated between species. However, the C. briggsae intra-species comparison reveals striking variation in the distribution of recombination between domains. Hybrid lines made with the more divergent pair of strains also exhibit pervasive marker transmission ratio distortion, evidence of selection acting on hybrid genotypes. The strongest effect, on chromosome III, is explained by a developmental delay phenotype exhibited by some hybrid F2 animals. In addition, on chromosomes IV and V, cross direction-specific biases towards one parental genotype suggest the existence of cytonuclear epistatic interactions. These interactions are discussed in relation to surprising mitochondrial genome polymorphism in C. briggsae, evidence that the two strains diverged in allopatry, the potential for local adaptation, and the evolution of Dobzhansky-Muller incompatibilities. The genetic and genomic resources resulting from this work will support future efforts to understand inter-strain divergence as well as facilitate studies of gene function, natural variation, and the evolution of recombination in Caenorhabditis nematodes

    Evaluation of the Effect of Systolic Blood Pressure and Pulse Pressure on Cognitive Function: The Women's Health and Aging Study II

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    Evidence suggests that elevated systolic blood pressure (SBP) and pulse pressure (PP) in midlife is associated with increased risk for cognitive impairment later in life. There is mixed evidence regarding the effects of late life elevated SBP or PP on cognitive function, and limited information on the role of female gender.Effects of SBPand PPon cognitive abilities at baseline and over a 9-year period were evaluated in 337 non-demented community-dwelling female participants over age 70 in the Women's Health and Aging Study II using logistic and Cox proportional hazards regression analyses. Participants aged 76-80 years with SBP≥160 mmHg or PP≥84 mmHg showed increased incidence of impairment on Trail Making Test-Part B (TMT, Part B), a measure of executive function, over time when compared to the control group that included participants with normal and pre-hypertensive SBP (<120 and 120-139 mmHg) or participants with low PP (<68 mmHg) (HR = 5.05 [95%CI = 1.42, 18.04], [HR = 5.12 [95%CI = 1.11; 23.62], respectively). Participants aged 70-75 years with PP≥71 mmHg had at least a two-fold higher incidence of impairment on HVLT-I, a measure of verbal learning, over time when compared to participants with low PP (<68 mmHg) (HR = 2.44 [95%CI = 1.11, 5.39]).Our data suggest that elevated SBP or PP in older non-demented women increases risk for late-life cognitive impairment and that PP could be used when assessing the risk for impairment in cognitive abilities. These results warrant further, larger studies to evaluate possible effects of elevated blood pressure in normal cognitive aging
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