3,081 research outputs found

    Creating accountability lines for sustainable rural water services in Tanzania

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    Rural water services in Tanzania are characterised by high non-functionality, unequal distribution and little accountability. One major reason is an unsuccessful decentralisation effort. This paper describes SNV Netherlands Development Organisation’s work on improving water point functionality by increasing accountability in the sector. After conducting different pilots, an intervention framework emerged that combines interventions that build the capacity of community owned water supply organisations (COWSO) to operate and manage their water services and increases claim-making powers of water users. The framework capacitates local councillors to provide oversight and introduces evidence-based planning, while capacitating local governments to regulate water services and support COWSOs. Lines of accountability and answerability between each of these actors are created throughout the interventions

    Biodiversity footprint of companies - Summary report

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    Companies are becoming increasingly aware of their impact on biodiversity and natural capital. This may result from their implicit dependence on natural capital, from increasingly more critical consumers, or from the genuine concern of company managers and owners. Consequently, companies have an increasing need for tools to enable them to gain insight into their impact on biodiversity, and to measure and assess the effects of measures to limit this impact. The Natural Captains project of the Platform Biodiversity, Ecosystems & Economy (Platform BEE) is stimulating companies to translate thinking and working with natural capital into tangible actions. This means making visible the impact of their activities on biodiversity and natural capital in terms of their biodiversity footprint. One way to assess a company’s impact on biodiversity is to measure the biodiversity footprint of their current activities and possibly also to compare this footprint with that of alternative measures

    Non-exponential one-body loss in a Bose-Einstein condensate

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    We have studied the decay of a Bose-Einstein condensate of metastable helium atoms in an optical dipole trap. In the regime where two- and three-body losses can be neglected we show that the Bose-Einstein condensate and the thermal cloud show fundamentally different decay characteristics. The total number of atoms decays exponentially with time constant tau; however, the thermal cloud decays exponentially with time constant (4/3)tau and the condensate decays much faster, and non-exponentially. We show that this behaviour, which should be present for all BECs in thermal equilibrium with a considerable thermal fraction, is due to a transfer of atoms from the condensate to the thermal cloud during its decay.Comment: The intuitive explanation of the atomic transfer effect has been correcte

    Land use scenarios for Viet Nam: From Global to Local

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    Magnetic-field dependent trap loss of ultracold metastable helium

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    We have experimentally studied the magnetic-field dependence of the decay of a Bose-Einstein condensate of metastable 4He atoms confined in an optical dipole trap, for atoms in the m=+1 and m=-1 magnetic substates, and up to 450 G. Our measurements confirm long-standing calculations of the two-body loss rate coefficient that show an increase above 50 G. We demonstrate that for m=-1 atoms, decay is due to three-body recombination only, with a three-body loss rate coefficient of 6.5(0.4)(0.6)10^(-27)cm^6s^(-1), which is interesting in the context of universal few-body theory. We have also searched for a recently-predicted d-wave Feshbach resonance, but did not observe it.Comment: 7 pages, 6 figure

    New Polymer Tensiometers: Measuring Matric Pressures Down to the Wilting Point

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    Tensiometers are commonly used for measuring soil water matric pressures. Unfortunately, the water-filled reservoir of conventional tensiometers limits their applicability to soil water matric pressures above approximately –0.085 MPa. Tensiometers filled with a polymer solution instead of water are able to measure a larger range of soil water matric pressures. We designed and constructed six prototype polymer tensiometers (previously called osmotic tensiometers) consisting of a wide-range pressure transducer with a temperature sensor, a stainless steel casing, and a ceramic plate with a membrane preventing polymer leakage. A polymer chamber (0.1–2.2 cm3) was located between the pressure transducer and the plate. We tested the polymer tensiometers for long-term operation, the effects of temperature, response times, and performance in a repacked sandy loam under laboratory conditions. Several months of continuous operation caused a gradual drop in the osmotic pressure, for which we developed a suitable correction. The osmotic potential of polymer solutions is temperature dependent, and requires calibration before installation. The response times to sudden and gradual changes in ambient temperature were found to be affected by polymer chamber height and polymer type. Practically useful response times (<0.2 d) are feasible, particularly for chambers shorter than 0.20 cm. We demonstrated the ability of the instrument to measure the range of soil water pressures in which plant roots are able to take up water (from 0 to –1.6 MPa), to regain pressure without user interference and to function properly for time periods of up to 1 yr

    The Internet addiction components model and personality: Establishing construct validity via a nomological network

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    There is growing concern over excessive and sometimes problematic Internet use. Drawing upon the framework of the components model of addiction (Griffiths, 2005), Internet addiction appears as behavioural addiction characterised by the following symptoms: salience, withdrawal, tolerance, mood modification, relapse and conflict. A number of factors have been associated with an increased risk for Internet addiction, including personality traits. The overall aim of this study was to establish the association between personality traits and the Internet addiction components model in order to develop a theoretical framework via a nomological network. Internet addiction and personality traits were assessed in two independent samples of 3,105 adolescents in the Netherlands and 2,257 university students in England. The results indicate that low agreeableness and high neuroticism/low emotional stability are associated the Internet addiction components factor in both samples. However, low conscientiousness and low resourcefulness predicted it in the adolescent sample only. The implications include the usage of the Internet addiction components model as parsimonious tool for the initial screening of potential clients in mental health institutes, and identifying populations at risk through their personality traits which may prove advantageous for the initiation of targeted preventions efforts

    Bacterial infections in cirrhosis: Role of proton pump inhibitors and intestinal permeability

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    Background Cirrhotic patients are at considerable risk for bacterial infections, possibly through increased intestinal permeability and bacterial overgrowth. Proton pump inhibitors (PPIs) may increase infection risk. We aimed to explore the potential association between PPI use and bacterial infection risk in cirrhotic patients and potential underlying mechanisms in complementary patient and animal models. Materials and methods Bacterial overgrowth was determined in jejunum of 30 rats randomly allocated to 6-week PPI treatment, gastrectomy or no treatment. In 84 consecutive cirrhotic patients, bacterial infection risk was prospectively assessed and related to PPI use. Intestinal permeability was determined by polyethylene glycol (PEG) test in nine healthy individuals and 12 cirrhotic patients. Results Bacterial overgrowth was much more common in jejunum of rats treated with PPI or gastrectomy compared with nontreated rats. Twenty-four patients (29%) developed a bacterial infection during a median follow-up of 28months. Although PPI users tended to experience infection more often than patients without PPI therapy, PPI use was not an independent predictor of bacterial infection (HR 1·2, 95% CI 0·5-3·0, P=0·72), after correction for Child-Pugh class (HR 3·6, 95% CI 1·5-8·7, P=0·004) and age (HR 1·05, 95%CI 1·01-1·09, P=0·02). In cirrhotic patients, 24-h urinary recovery of PEGs 1500 and 3350 was significantly higher compared with healthy controls. Conclusions Although in our animal model PPIs induced intestinal overgrowth, stage of liver disease rather than PPI use was the predominant factor determining infection risk in cirrhotic patients. Increased intestinal permeability may be a factor contributing to infection risk

    Perfusion CT to evaluate the effect of transluminal angioplasty on cerebral perfusion in the treatment of vasospasm after subarachnoid hemorrhage

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    INTRODUCTION: Delayed ischemic neurologic deficits secondary to vasospasm are a major cause of morbidity and mortality after subarachnoid hemorrhage (SAH). Treatment of vasospasm after SAH is associated with complications, and reliable techniques for evaluating effects of treatment of vasospasm in such patients are warranted. We present the use of perfusion computed tomography (PTC) to evaluate the effect of transluminal percutaneous angioplasty in a with SAH and vasospasm-induced ischemia. METHODS: Dynamic PCT with deconvolution produced maps of time-to-peak, mean transit time, regional cerebral blood flow, and regional cerebral blood volume, with a computerized automated map of the infarct and penumbra. CT scanners with quadruple detector array were used before and after angioplasty. RESULTS: Before angioplasty and intraarterial papaverine, PCT showed normal to decreased cerebral blood flow and increased cerebral blood volume and mean transit time in the middle cerebral artery territory of the left hemisphere. After angioplasty and intraarterial papaverine, PCT showed normalization of perfusion parameters. CONCLUSION: PCT can be a useful technique in monitoring angioplasty treatment effects in patients with vasospasm after SA
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