7,036 research outputs found

    Modeling and optimization of production and distribution of drinking water at VMW

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    We develop and discuss an operational planning model aiming at minimizing production and distribution costs in large drinking water networks containing buffers with free inflow. Modeling drinking water networks is very challenging due of the presence of complex hydraulic constraints, such as friction losses and pump curves. Non-linear, non-convex constraints result from the relationships between pressure and flow in power terms. Also, binary variables are needed to model the possibility of free inflow or re-injection of water at reservoirs. The resulting model is thus a non-convex Mixed-Integer Non-Linear Program (MINLP). A discrete-time setting is proposed to solve the problem over a finite horizon made of several intervals. A commercial solver, BONMIN, suited for convex MINLP models is used to heuristically solve the problem. We are able to find a good solution for a small part of an existing network operated by the Vlaamse Maatschappij voor Watervoorziening (VMW), a major drinking water company in Flanders

    Environmental factors influence both abundance and genetic diversity in a widespread bird species.

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    Genetic diversity is one of the key evolutionary variables that correlate with population size, being of critical importance for population viability and the persistence of species. Genetic diversity can also have important ecological consequences within populations, and in turn, ecological factors may drive patterns of genetic diversity. However, the relationship between the genetic diversity of a population and how this interacts with ecological processes has so far only been investigated in a few studies. Here, we investigate the link between ecological factors, local population size, and allelic diversity, using a field study of a common bird species, the house sparrow (Passer domesticus). We studied sparrows outside the breeding season in a confined small valley dominated by dispersed farms and small-scale agriculture in southern France. Population surveys at 36 locations revealed that sparrows were more abundant in locations with high food availability. We then captured and genotyped 891 house sparrows at 10 microsatellite loci from a subset of these locations (N = 12). Population genetic analyses revealed weak genetic structure, where each locality represented a distinct substructure within the study area. We found that food availability was the main factor among others tested to influence the genetic structure between locations. These results suggest that ecological factors can have strong impacts on both population size per se and intrapopulation genetic variation even at a small scale. On a more general level, our data indicate that a patchy environment and low dispersal rate can result in fine-scale patterns of genetic diversity. Given the importance of genetic diversity for population viability, combining ecological and genetic data can help to identify factors limiting population size and determine the conservation potential of populations

    Adaptive latitudinal variation in Common Blackbird Turdus merula nest characteristics

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    Nest construction is taxonomically widespread, yet our understanding of adaptive intraspecific variation in nest design remains poor. Nest characteristics are expected to vary adaptively in response to predictable variation in spring temperatures over large spatial scales, yet such variation in nest design remains largely overlooked, particularly amongst open-cup-nesting birds. Here, we systematically examined the effects of latitudinal variation in spring temperatures and precipitation on the morphology, volume, composition, and insulatory properties of open-cup-nesting Common Blackbirds’ Turdus merula nests to test the hypothesis that birds living in cooler environments at more northerly latitudes would build better insulated nests than conspecifics living in warmer environments at more southerly latitudes. As spring temperatures increased with decreasing latitude, the external diameter of nests decreased. However, as nest wall thickness also decreased, there was no variation in the diameter of the internal nest cups. Only the mass of dry grasses within nests decreased with warmer temperatures at lower latitudes. The insulatory properties of nests declined with warmer temperatures at lower latitudes and nests containing greater amounts of dry grasses had higher insulatory properties. The insulatory properties of nests decreased with warmer temperatures at lower latitudes, via changes in morphology (wall thickness) and composition (dry grasses). Meanwhile, spring precipitation did not vary with latitude, and none of the nest characteristics varied with spring precipitation. This suggests that Common Blackbirds nesting at higher latitudes were building nests with thicker walls in order to counteract the cooler temperatures. We have provided evidence that the nest construction behavior of open-cup-nesting birds systematically varies in response to large-scale spatial variation in spring temperatures

    Deep Hole States in Medium Mass Nuclei

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    Supported by the National Science Foundation and Indiana Universit

    Biosensors for the monitoring of harmful algal blooms

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    Peer Reviewed Paper. DOI: https://doi.org/10.1016/j.copbio.2017.02.018 Citation: McPartlin, D. A., Loftus, J. H., Crawley, A. S., Silke, J., Murphy, C. S., & O’Kennedy, R. J. (2017). Biosensors for the monitoring of harmful algal blooms. Current Opinion in Biotechnology, 45, 164–169. https://doi.org/10.1016/j.copbio.2017.02.018Harmful algal blooms (HABs) are a major global concern due to their propensity to cause environmental damage, healthcare issues and economic losses. In particular, the presence of toxic phytoplankton is a cause for concern. Current HAB monitoring programs often involve laborious laboratory-based analysis at a high cost and with long turnaround times. The latter also hampers the potential to develop accurate and reliable models that can predict HAB occurrence. However, a promising solution for this issue may be in the form of remotely deployed biosensors, which can rapidly and continuously measure algal and toxin levels at the point-of-need (PON), at a low cost. This review summarises the issues HABs present, how they are difficult to monitor and recently developed biosensors that may improve HAB-monitoring challenges

    Quantum groups and double quiver algebras

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    For a finite dimensional semisimple Lie algebra g{\frak{g}} and a root qq of unity in a field k,k, we associate to these data a double quiver Qˉ.\bar{\cal{Q}}. It is shown that a restricted version of the quantized enveloping algebras Uq(g)U_q(\frak g) is a quotient of the double quiver algebra kQˉ.k\bar{\cal Q}.Comment: 15 page

    Why Should ACT Work When CBT Has Failed? a Study Assessing Acceptability and Feasibility of Acceptance and Commitment Therapy (ACT) for Paediatric Patients With Chronic Fatigue Syndrome/myalgic Encephalomyelitis (CFS/ME)

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    AIMS: Paediatric chronic fatigue syndrome/myalgic encephalomyelitis (CFS/ME) effects 0.5–3.28% of children. NICE guidance recommends Activity Management, Graded Exercise Therapy or Cognitive Behavioural Therapy for fatigue (CBT-f). Approximately 15% of patients do not achieve full recovery within one year with current treatments. Acceptance and Commitment Therapy (ACT) is an effective treatment in many chronic illnesses. There are no studies investigating ACT for paediatric CFS/ME. This feasability study aimed to assess if ACT is a feasible and acceptable alternative treatment when current treatment has not led to recovery. METHODS: This feasability cohort study aimed to enrol a minimum of 12 participants aged 11–18 yearswith CFS/ME attending the Royal United Hospitals Bath NHS Foundation Trust Specialist Paediatric CFS/ME Service, who were still symptomatic after 12 months or 12 sessions of standard treatment and were offered six to 12 sessions of ACT. Retention and recruitment data were analysed. Participants were asked to complete questionnaires before, during and after treatment. A selection of participants and their parents were interviewed about their experience of the study. Interviews were analysed using thematic analysis. RESULTS: 19 participants (95% of those approached) were recruited. Only 4 participants of this hard-to-reach group did not complete treatment. In almost all sessions participants reported that they felt ‘totally’ listened to in post session questionnaires (31/33 sessions). Preliminary interviews (n = 12) indicate acceptability of ACT, with all young people and their parents stating that they thought ACT should be offered to this population. Participants particularly commented that the absence of thought challenging (used in CBT-f) was a positive element of ACT. Participant's openness to try new approaches and altruistic desire to be in a study was noted. CONCLUSION: Recruitment data indicate that it is feasible to recruit and retain 11–18-year-olds with CFS/ME to a study offering ACT. Interviews with participants and parents were broadly positive suggesting ACT is an acceptable treatment in this population. Results indicated that it is both feasible and acceptable to offer ACT to 11–18-year-olds with CFS/ME using this protocol, supporting the prospect of an RCT in this area

    Anaemia and blood transfusion in African children presenting to hospital with severe febrile illness

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    BACKGROUND: Severe anaemia in children is a leading cause of hospital admission and a major cause of mortality in sub-Saharan Africa, yet there are limited published data on blood transfusion in this vulnerable group. METHODS: We present data from a large controlled trial of fluid resuscitation (Fluid Expansion As Supportive Therapy (FEAST) trial) on the prevalence, clinical features, and transfusion management of anaemia in children presenting to hospitals in three East African countries with serious febrile illness (predominantly malaria and/or sepsis) and impaired peripheral perfusion. RESULTS: Of 3,170 children in the FEAST trial, 3,082 (97%) had baseline haemoglobin (Hb) measurement, 2,346/3,082 (76%) were anaemic (Hb <10 g/dL), and 33% severely anaemic (Hb <5 g/dL). Prevalence of severe anaemia varied from 12% in Kenya to 41% in eastern Uganda. 1,387/3,082 (45%) children were transfused (81% within 8 hours). Adherence to WHO transfusion guidelines was poor. Among severely anaemic children who were not transfused, 52% (54/103) died within 8 hours, and 90% of these deaths occurred within 2.5 hours of randomisation. By 24 hours, 128/1,002 (13%) severely anaemic children had died, compared to 36/501 (7%) and 71/843 (8%) of those with moderate and mild anaemia, respectively. Among children without severe hypotension who were randomised to receive fluid boluses of 0.9% saline or albumin, mortality was increased (10.6% and 10.5%, respectively) compared to controls (7.2%), regardless of admission Hb level. Repeat transfusion varied from ≤2% in Kenya/Tanzania to 6 to 13% at the four Ugandan centres. Adverse reactions to blood were rare (0.4%). CONCLUSIONS: Severe anaemia complicates one third of childhood admissions with serious febrile illness to hospitals in East Africa, and is associated with increased mortality. A high proportion of deaths occurred within 2.5 hours of admission, emphasizing the need for rapid recognition and prompt blood transfusion. Adherence to current WHO transfusion guidelines was poor. The high rates of re-transfusion suggest that 20 mL/kg whole blood or 10 mL/kg packed cells may undertreat a significant proportion of anaemic children. Future evaluation of the impact of a larger volume of transfused blood and optimum transfusion management of children with Hb of <6 g/dL is warranted. Please see related article: http://dx.doi.org/10.1186/s12916-014-0248-5. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1186/s12916-014-0246-7) contains supplementary material, which is available to authorized users

    WHO guidelines on fluid resuscitation in children: missing the FEAST data.

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    The World Health Organization recommendations on management of common childhood illnesses affect the lives of millions of children admitted to hospital worldwide. Its latest guidelines,1 released in May 2013, continue to recommend rapid fluid resuscitation for septic shock, even though the only large controlled trial of this treatment (Fluid Expansion as a Supportive Treatment (FEAST) found that it increased the risk of death in African children.2 A subsequent systematic review of bolus resuscitation in children with shock resulting from severe infection also did not support its use.3 Failure to take this evidence into account is not consistent with WHO’s commitment to systematically and transparently assess evidence using the GRADE (Grading of Recommendations Assessment, Development and Evaluation) process when producing guidelines and could endanger the lives of children
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