269 research outputs found

    Development of Simplified Models of Water Quality in Lignite Mining Areas

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    The development of complex decision support model systems for the analysis of regional water policies for regions with intense socio-economic development effecting and being affected by the water resources system is of increasing importance. One of the most illustrative examples are regions with open-pit lignite mining. Such model systems have to be based on appropriate submodels e.g. for water quality processes. The paper describes submodel for groundwater and surface water quality with special regard to open-pit lignite mining regions. We consider the discharge of acid ferruginous water into rivers as having the most important impact on water quality in open-pit lignite mining areas. One goal of the model system is the choice of the necessary degree of purification for mine water treatment plants, taking into account self-purification in rivers and remaining pits as well as the water quality demand of down-stream water users. Based on comprehensive water quality models, the development of which is described in the paper, the possibilities for the derivation of reduced models are described. Those model have been elaborated for groundwater, as the source of pollution, mine water treatment plants as control units, river sections with an intake of acid ferruginous water, and remaining pits, which can also serve as effective control units. Related with each other, these models form the complex system model, a system of differential equations. They were numerically solved. The computer program is included in the paper

    Water Policies: Regions with Open-Pit Lignite Mining (Introduction to the IIASA Study)

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    There is an apparent need for the analysis of long-term regional water policies to reconcile conflicting interests in regions with open-pit lignite mining. The most important. interest groups in such regions are mining, municipal and industrial water supply, agriculture as well as the "environment". A scientifically sound and practically simple policy-oriented system of methods and computerized procedures has to be developed. To develop such a system is part of the research work in the Regional Water Policies project carried out at the International Institute for Applied Systems Analysis (IIASA) in collaboration with research institutes in the German Democratic Republic, Poland, and in other countries as well. A test area that includes typical water-related elements of mining regions and significant conflicts and interest groups has been chosen. The first stage in the analysis is oriented towards developing a scenario generating system as a tool to choose "good" policies from the regional point of view. Therefore a policy-oriented interactive decision support model system is under development, considering the dynamic, nonlinear and uncertain systems behaviour. It combines a model for multi-criteria analysis in planning periods with a simulation model for monthly systems behaviour. The paper outlines the methodological approach. describes the test region in the GDR, and the submodels for the test region

    Paraphrases and summaries: A means of clarification or a vehicle for articulating a preferred version of student accounts?

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    The use of group discussions as a means to facilitate learning from experiences is well documented in adventure education literature. Priest and Naismith (1993) assert that the use of the circular discussion method, where the leader poses questions to the participants, is the most common form of facilitation in adventure education. This paper draws on transcripts of facilitation sessions to argue that the widely advocated practice of leader summaries or paraphrases of student responses in these sessions functions as a potential mechanism to control and sponsor particular knowledge(s). Using transcripts from recorded facilitation sessions the analysis focuses on how the leader paraphrases the students’ responses and how these paraphrases or ‘formulations’ function to modify or exclude particular aspects of the students’ responses. I assert that paraphrasing is not simply a neutral activity that merely functions to clarify a student response, it is a subtle means by which the leader of the session can, often inadvertently or unknowingly, alter the student’s reply with the consequence of favouring particular knowledge(s). Revealing the subtle work that leader paraphrases perform is of importance for educators who claim to provide genuine opportunities for students to learn from their experience

    Risk factors for presentation to hospital with severe anaemia in Tanzanian children: a case-control study.

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    In malaria endemic areas anaemia is a usually silent condition that nevertheless places a considerable burden on health services. Cases of severe anaemia often require hospitalization and blood transfusions. The objective of this study was to assess risk factors for admission with anaemia to facilitate the design of anaemia control programmes. We conducted a prospective case-control study of children aged 2-59 months admitted to a district hospital in southern Tanzania. There were 216 cases of severe anaemia [packed cell volume (PCV) < 25%] and 234 age-matched controls (PCV > or = 25%). Most cases [55.6% (n = 120)] were < 1 year of age. Anaemia was significantly associated with the educational level of parents, type of accommodation, health-seeking behaviour, the child's nutritional status and recent and current medical history. Of these, the single most important factor was Plasmodium falciparum parasitaemia [OR 4.3, 95% confidence interval (CI) 2.9-6.5, P < 0.001]. Multivariate analysis showed that increased recent health expenditure [OR 2.2 (95% CI 1.3-3.9), P = 0.005], malnutrition [OR 2.4 (95%CI 1.3-4.3), P < 0.001], living > 10 km from the hospital [OR 3.0 (95% CI 1.9-4.9), P < 0.001], a history of previous blood transfusion [OR 3.8 (95% CI 1.7-9.1), P < 0.001] and P. falciparum parasitaemia [OR 9.5 (95% CI 4.3-21.3), P < 0.001] were independently related to risk of being admitted with anaemia. These findings are considered in terms of the pathophysiological pathway leading to anaemia. The concentration of anaemia in infants and problems of access to health services and adequate case management underline the need for targeted preventive strategies for anaemia control

    Identification of KasA as the cellular target of an anti-tubercular scaffold

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    Phenotypic screens for bactericidal compounds are starting to yield promising hits against tuberculosis. In this regard, whole-genome sequencing of spontaneous resistant mutants generated against an indazole sulfonamide (GSK3011724A) identifies several specific single-nucleotide polymorphisms in the essential Mycobacterium tuberculosis β-ketoacyl synthase (kas) A gene. Here, this genomic-based target assignment is confirmed by biochemical assays, chemical proteomics and structural resolution of a KasA-GSK3011724A complex by X-ray crystallography. Finally, M. tuberculosis GSK3011724A-resistant mutants increase the in vitro minimum inhibitory concentration and the in vivo 99% effective dose in mice, establishing in vitro and in vivo target engagement. Surprisingly, the lack of target engagement of the related β-ketoacyl synthases (FabH and KasB) suggests a different mode of inhibition when compared with other Kas inhibitors of fatty acid biosynthesis in bacteria. These results clearly identify KasA as the biological target of GSK3011724A and validate this enzyme for further drug discovery efforts against tuberculosis

    Diversity in collaborative research communities: a multicultural, multidisciplinary thesis writing group in public health

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    Writing groups for doctoral students are generally agreed to provide valuable learning spaces for Ph.D. candidates. Here an academic developer and the eight members of a writing group formed in a Discipline of Public Health provide an account of their experiences of collaborating in a multicultural, multidisciplinary thesis writing group. We consider the benefits of belonging to such a group for Ph.D. students who are operating in a research climate in which disciplinary boundaries are blurring and where an increasing number of doctoral projects are interdisciplinary in nature; in which both academic staff and students come from enormously diverse cultural and language backgrounds; and in which teamwork, networking and collaboration are prized but not always proactively facilitated. We argue that doctoral writing groups comprising students from diverse cultural and disciplinary backgrounds can be of significant value for postgraduates who wish to collaborate on their own academic development to improve their research writing and communication skills; at the same time, such collaborative work effectively builds an inclusive, dynamic research community.Cally Guerin, Vicki Xafis, Diana V. Doda, Marianne H. Gillam, Allison J. Larg, Helene Luckner, Nasreen Jahan, Aris Widayati and Chuangzhou X

    Impact of Plasmodium falciparum infection on the frequency of moderate to severe anaemia in children below 10 years of age in Gabon

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    BACKGROUND: Improving the understanding of childhood malarial anaemia may help in the design of appropriate management strategies. METHODS: A prospective observational study over a two-year period to assess the burden of anaemia and its relationship to Plasmodium falciparum infection and age was conducted in 8,195 febrile Gabonese children. RESULTS: The proportion of children with anaemia was 83.6% (n = 6830), higher in children between the ages of six and 23 months. Those under three years old were more likely to develop moderate to severe anaemia (68%). The prevalence of malaria was 42.7% and P. falciparum infection was more frequent in children aged 36-47 months (54.5%). The proportion of anaemic children increased with parasite density (p 60%), but was unrelated to P. falciparum parasitaemia. CONCLUSION: Malaria is one of the main risk factors for childhood anaemia which represents a public health problem in Gabon. The risk of severe malarial anaemia increases up the age of three years. Efforts to improve strategies for controlling anaemia and malaria are needed

    Cerebellar Zones: A Personal History

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    Cerebellar zones were there, of course, before anyone noticed them. Their history is that of young people, unhindered by preconceived ideas, who followed up their observations with available or new techniques. In the 1960s of the last century, the circumstances were fortunate because three groups, in Leiden, Lund, and Bristol, using different approaches, stumbled on the same zonal pattern in the cerebellum of the cat. In Leiden, the Häggqvist myelin stain divulged the compartments in the cerebellar white matter that channel the afferent and efferent connections of the zones. In Lund, the spino-olivocerebellar pathways activated from individual spinal funiculi revealed the zonal pattern. In Bristol, charting the axon reflex of olivocerebellar climbing fibers on the surface of the cerebellum resulted in a very similar zonal map. The history of the zones is one of accidents and purposeful pursuit. The technicians, librarians, animal caretakers, students, secretaries, and medical illustrators who made it possible remain unnamed, but their contributions certainly should be acknowledged

    Developing a Growth Mindset through outdoor personal development: can an intervention underpinned by psychology increase the impact of an outdoor learning course for young people?

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    This study considers the impact of using a series of Mindset interventions during a five-day outdoor personal development (OPD) course. Self-efficacy, resilience and Mindset were measured pre course, post course and one month post course. It was hypothesised that both experimental and control groups would increase their self-efficacy and resilience, and that the Mindset (experimental) group would significantly increase beyond the levels of the control group, who took part in the standard OPD course. It was also predicted that the Mindset group would move towards a Growth Mindset, whereas the control group would not show any change in Mindset. Hypotheses were tested using a randomised, quasi-experimental method. Separate mixed analyses of variance were carried out for each dependent variable, followed by planned comparisons and post-hoc tests using a Bonferroni correction. Results showed that both groups increased self-efficacy over time; however, there was no further significance for the experimental group. Resilience only increased significantly in the experimental group while the control group made no significant gain, and students in the experimental group moved significantly towards a Growth Mindset while the control group did not

    Impact of renal impairment on atrial fibrillation: ESC-EHRA EORP-AF Long-Term General Registry

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    Background: Atrial fibrillation (AF) and renal impairment share a bidirectional relationship with important pathophysiological interactions. We evaluated the impact of renal impairment in a contemporary cohort of patients with AF. Methods: We utilised the ESC-EHRA EORP-AF Long-Term General Registry. Outcomes were analysed according to renal function by CKD-EPI equation. The primary endpoint was a composite of thromboembolism, major bleeding, acute coronary syndrome and all-cause death. Secondary endpoints were each of these separately including ischaemic stroke, haemorrhagic event, intracranial haemorrhage, cardiovascular death and hospital admission. Results: A total of 9306 patients were included. The distribution of patients with no, mild, moderate and severe renal impairment at baseline were 16.9%, 49.3%, 30% and 3.8%, respectively. AF patients with impaired renal function were older, more likely to be females, had worse cardiac imaging parameters and multiple comorbidities. Among patients with an indication for anticoagulation, prescription of these agents was reduced in those with severe renal impairment, p&nbsp;&lt;.001. Over 24&nbsp;months, impaired renal function was associated with significantly greater incidence of the primary composite outcome and all secondary outcomes. Multivariable Cox regression analysis demonstrated an inverse relationship between eGFR and the primary outcome (HR 1.07 [95% CI, 1.01–1.14] per 10&nbsp;ml/min/1.73&nbsp;m2 decrease), that was most notable in patients with eGFR &lt;30&nbsp;ml/min/1.73&nbsp;m2 (HR 2.21 [95% CI, 1.23–3.99] compared to eGFR ≥90&nbsp;ml/min/1.73&nbsp;m2). Conclusion: A significant proportion of patients with AF suffer from concomitant renal impairment which impacts their overall management. Furthermore, renal impairment is an independent predictor of major adverse events including thromboembolism, major bleeding, acute coronary syndrome and all-cause death in patients with AF
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