558 research outputs found

    Impacts of Rainfall and Forest Cover Change on Runoff in Small Catchments: A Case Study of Mulunguzi and Namadzi Catchment Areas in Southern Malawi

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    The impacts of climate change on water resources have received much attention globally especially in the last 30 years. Rainfall, the main driver of the hydrological cycle, has been varying in parts of the world in various ways. The picture is more complicated if impacts of land cover changes on water resources are also taken into consideration. These two pose challenges which require an integrated approach to address. Not many of such studies have been conducted in Malawian catchments and other tropical regions. In this study, annual, seasonal and monthly series of rainfall and river discharge of the Mulunguzi and Namadzi River catchments, two small sub-catchments in the Lake Chilwa catchment area, were analysed for trends using the non parametric Mann-Kendall statistic and Sens slope estimator. Further, Linear regression and the RainRU model were applied to establish whether the relationship between rainfall and runoff in the two catchments has changed. Furthermore, linear regression was used to establish how increased forest cover has influenced river flows in the two catchments. The results suggest that rainfall in the Mulunguzi catchment has decreased significantly at all scales and this has also led to reduced river flows. Increased forest cover since the pre 1950s has also resulted in reduced flows but this is not as significant as the rainfall decrease. In the Namadzi catchment, the rainfall trends suggest a varying pattern with no obvious straight trends. At annual and some months timescale, the rainfall has increased significantly. The river flow on the other hand suggests an overall declining pattern. This pattern is well linked with significant forest area increments which have occurred since 1995. It is therefore important that more detailed studies should be conducted to gain further insight to these relations as both catchments are important socioeconomically.Keywords: Land use; land cover; river flow; rainfall; climate change

    Does size matter?:Hospital volume and resource use in paediatric diabetes care

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    Aims: Paediatric diabetes care has become increasingly specialised due to the multidisciplinary approach and technological developments. Guidelines recommend sufficient experience of treatment teams. This study evaluates associations between hospital volume and resource use and hospital expenditure in Dutch children with diabetes. Methods: Retrospective cohort study using hospital claims data of 5082 children treated across 44 Dutch hospitals (2019–2020). Hospitals were categorised into three categories; small (≥20–100 patients), medium (≥100–200 patients) and large (≥200 patients). All-cause hospitalisations, consultations, technology and hospital expenditure were analysed and adjusted for age, sex, socio-economic status (SES) and hospital of treatment. Results: Fewer hospitalisations were observed in large hospitals compared to small hospitals (OR 0.48; [95% CI 0.32–0.72]; p &lt; 0.001). Median number of yearly paediatrician visits was 7 in large and 6 in small hospitals, the significance of which was attenuated in multilevel analysis (OR ≥7 consultations: 1.89; [95%CI 0.74–4.83]; p = 0.18). Technology use varies between individual hospitals, whereas pump usage and real-time continuous glucose monitoring showed no significant differences between hospital volumes. Mean overall expenditure was highest in medium-sized centres with €6434 per patient (IQR €2555–7955); the difference in diabetes care costs was not significant between hospital patient volumes. Conclusions: Care provision patterns vary by hospital patient volume. Large hospitals had the lowest hospitalisation rates. The use of diabetes technology was not different between hospital patient volumes. Medium-sized hospitals showed the highest overall expenditure, but diabetes care costs were similar across hospital volumes.</p

    Telemedicine in interdisciplinary work practices: On an IT system that met the criteria for success set out by its sponsors, yet failed to become part of every-day clinical routines

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    Background. Information systems can play a key role in care innovations including task redesign and shared care. Many demonstration projects have presented evidence of clinical and cost effectiveness and high levels of patient satisfaction. Yet these same projects often fail to become part of everyday clinical routines. The aim of the paper is to gain insight into a common paradox that a technology can meet the criteria for success set out at the start of the project yet fail to become part of everyday clinical routines. Methods. We evaluated a telecare service set up to reduce the workload of ophthalmologists. In this project, optometrists in 10 optical shops made digital images to detect patients with glaucoma which were furth

    Effects of selected dams on river flows of Insiza River, Zimbabwe

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    This paper examines effects of three dams on flow characteristics of Insiza River on which they are located. The storage capacities of these dams varies from an equivalent of 48–456% of the mean annual runoff. Mean annual runoff and annual maximum flood flows have not been modified by the presence of these dams. The average number of days per year without runoff had decreased downstream of two dams. A comparison was made of flow duration curves at sites upstream and downstream of the selected dams. Significant differences were detected between the flow duration curves of upstream and downstream sites. Exceedance frequencies of low flows had decreased downstream of two dams, while these had increased downstream of the other dam. The study recommends development of operating rules for these dams that will ensure that changes detected in low flows do not adversely affect instream flow requirement

    Investigation of the structure and microhardness of Mo-Fe-C coatings obtained by the electron beam injected in the atmosphere

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    In this work 'Mo-Fe-C' coatings fabricated on medium carbon steel by non-vacuum electron beam cladding were investigated. The structure of coatings and transition zones were studied by scanning electron microscopy (SEM). It was shown that an increase of Fe percentage in the cladding mixture led to a decrease of the eutectic volume fraction in the coating and was accompanied by the formation of the gradient structure between the coating and a substrate material. Measurements of microhardness in the cross section of samples revealed that the cladding of a 'Mo-C powder mixture contributed to a 4.5-fold increase of microhardness

    Control methods for Dermanyssus gallinae in systems for laying hens: results of an international seminar

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    This paper reports the results of a seminar on poultry red mite (PRM), Dermanyssus gallinae. Eighteen researchers from eight European countries discussed life cycle issues of the mite, effects of mites on hens and egg production, and monitoring and control methods for PRM in poultry facilities. It was determined that PRM probably causes more damage than envisaged, with the cost in The Netherlands alone reaching 11 million euro per annum. However a great deal is still unknown about PRM (e.g. reproduction, survival methods, etc.) and that PRM monitoring is an important instrument in recognising and admitting the problem and in taking timely measures. Currently, the most promising control method combines heating the hen house in combination with chemical treatments. Future areas of development which show promise include the use of entomopathogenic fungi, vaccination and predatory mites. The final aim is to solve the problem of D. gallinae in housing systems for laying hens

    Impact and sustainability of low-head drip irrigation kits, in the semi-arid Gwanda and Beitbridge Districts, Mzingwane Catchment, Limpopo Basin, Zimbabwe

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    Resource-poor smallholder farmers in the semi-arid Gwanda and Beitbridge districts face food insecurity on an annual basis due to a combination of poor and erratic rainfall (average 500 mm/a and 345 mm/a, respectively, for the period 1970–2003) and technologies inappropriate to their resource status. This impacts on both household livelihoods and food security. In an attempt to improve food security in the catchment a number of drip kit distribution programmes have been initiated since 2003 as part of an on-going global initiative aimed at 2 million poor households per year. A number of recent studies have assessed the technical performance of the drip kits in-lab and in-field. In early 2005 a study was undertaken to assess the impacts and sustainability of the drip kit programme. Representatives of the NGOs, local government, traditional leadership and agricultural extension officers were interviewed. Focus group discussions with beneficiaries and other villagers were held at village level. A survey of 114 households was then conducted in two districts, using a questionnaire developed from the output of the interviews and focus group discussions..
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