44 research outputs found

    Modelling the potential impact of spatially targeted natural flood management at the landscape scale for a rural UK catchment.

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    Flooding has a significant impact across a large portion of the United Kingdom. Many flood risk reduction schemes focus on hard engineering approaches which are capable of protecting a large amount of infrastructure and properties. However, for a sparsely populated rural catchment that does not meet central cost-benefit criteria required for hard engineering schemes, the potential for a reduction in flood risk through a sustainable, lower-cost approach can create a viable alternative. Natural flood management is an approach that is growing in application in the UK with regards to helping reduce flood risk at a catchment scale; however there is a need for the potential impacts on flooding and wider catchment dynamics of the techniques and interventions to be quantified before potential schemes can attain funding; there is currently a lack of empirical evidence available to support this quantification. This research project used a combination of a physically-based, fully spatially-distributed hydrological model (CRUM3), a risk-based model focused on hydrological connectivity (SCIMAP-Flood) and stakeholder engagement to develop and model natural flood management interventions at the landscape scale. The process allowed for the quantification of the impact of a variety of natural flood management interventions at reducing the maximum discharge for the simulated flooding event. These methods were applied to the study area of the River Roe catchment in Cumbria, a 69km2 rural catchment that experienced significant flooding events in both 2005 and 2013. The effectiveness of a variety of flood risk reduction scenarios in the River Roe catchment were tested; these scenarios included spatially targeted land cover change to attenuate overland flow, soil aeration to mitigate soil compaction issues commonly associated with rural catchments and woody debris dams to slow the delivery of water downstream. It was established through the research that a significant proportion of land has to be acted upon to have a noticeable reduction in the maximum discharge produced during a flood event; as a consequence of this finding, large-scale soil aeration to keep soil compaction to low levels throughout the catchment is arguably the most effective natural flood management measure for this catchment

    Catchment-scale spatial targeting of flood management measures to reduce flood hazard: An end-to-end modelling approach applied to the East Rapti catchment, Nepal

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    Globally, practical approaches to managing flood hazards are moving away from mitigation solely at the point of the impact, and towards an integrated catchment-scale approach which considers flood source areas, flow pathways of flood waters and impacted communities. The current method for managing the fluvial flood risk in Nepal, however, generally involves localised structural interventions in affected areas using a static and reactive approach. This method does not create long term resilience to the hazards. There is therefore the need to rely less on these large-scale structural measures and focus instead on sustainable and non-structural measures for flood mitigation that allow the catchments and communities within them to be more resilient. The three-stage, end-to-end approach developed in this thesis provides a process to help shift towards an integrated catchment management for flood hazard reduction in Nepal. The approach centres on identifying flood water source areas within the catchment and spatially targeting flood management measures in these locations. Consideration is also given to the potential impact of future, flow magnitude increasing, land cover change such as deforestation and the abandonment of terraced agriculture that is evident in many Nepali catchments. Stage 1 adopts SCIMAP-Flood, a catchment-scale decision support framework that identifies critical source areas for flood waters. The framework uses maps flood water generating areas based on spatial rainfall patterns and land cover, the incorporation of travel times across a catchment, and modelling of hydrological connectivity. Outputs are used to create catchment-scale flood management scenarios which target flood source areas; tested flood management measures include targeted afforestation, check dams in key sub-catchments and abandoned terrace restoration. In Stage 2 the flood management scenarios are assessed using CRUM3, a physically-based, spatially distributed, catchment-scale hydrological model. The impact of the flood management measures can be evaluated throughout the catchment using the modelled change in discharge. Stage 3 uses LISFLOOD-FP, a 2D flood inundation model, to establish the change flood inundation patterns at key flood impacted communities within the catchment from the created flood management scenarios. Stage 2 and Stage 3 utilise a coupled hydrological-hydraulic modelling approach with the results from the CRUM3 model entering the LISFLOOD-FP model as inflow hydrographs. The approach is applied to the East Rapti catchment, a 3,084 km2 sub-catchment of the Nayarani River in southern central Nepal. The catchment contains three river flow gauges (Lothar Khola [catchment area - 169 km2], Manahari Khola [427 km2] and Rapti River [471 km2]) placed within the main sub-catchments and eight rainfall gauges. Additional data used to drive the approach was attained from global datasets and acquired during fieldwork. This thesis has researched the potential effectiveness of the implementation of flood management interventions at the catchment-scale and evidences an alternative approach to flood management that is applicable in both Nepal and the wider Himalayan Region. Based on the integrated modelling approach, the results predict that the high flow magnitudes in the East Rapti catchment can be reduced through a catchment-scale approach. However, even with a combined approach of large scale spatially targeted afforestation and check dam implementation (Q99.9 decrease of <=5.3%), the use of solely catchment-scale flood management approaches to combat flood hazard might not be effective at reducing the flood impact to at-risk communities. A significant outcome from the catchment-scale modelling work was that there is a far greater potential for land use change to increase, rather than reduce through mitigation, flow magnitudes in the East Rapti catchment. The model results suggest that any land within the East Rapti catchment that is altered from existing forest will contribute to increasing the flow magnitude (Q99.9 increase of up to 48.2%)

    Unrecognised Outbreak: Human parainfluenza virus infections in a pediatric oncology unit.  A new diagnostic PCR and virus monitoring system may allow early detection of future outbreaks.

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    Background: Human parainfluenza viruses (HPIVs) are significant causes of both upper and lower respiratory tract infections with type 3 (HPIV3) causing the most severe disease in the immunocompromised cohorts.  The objective of this study was to analyse the epidemiological nature of a cluster of cases of HPIV3 in a pediatric oncology unit of a major teaching hospital. Methods: In order to determine whether the activity observed represented a deviation from the norm, seasonal trends of HPIV3 in the surrounding geographical area as well as on the ward in question were analysed.  The genetic link between cases was established by the phylogenetic analysis of the non-coding hypervariable region between the M (Matrix) and F (fusion) genes of HPIV3. The 15 cases involved and 15 unrelated cases were sequenced.  Transmission routes were subsequently inferred and visualized using Konstanz Information Miner (KNIME) 3.3.2. Results: Of the 15 cases identified, 14 were attributed to a point source outbreak. Two out of 14 outbreak cases were found to differ by a single mutation A182C. The outbreak strain was also seen in 1 out of 15 unrelated cases, indicating that it was introduced from the community. Transmission modeling was not able to link all the cases and establish a conclusive chain of transmission. No staff were tested during the outbreak period. No deaths occurred as a result of the outbreak. Conclusion: A point source outbreak of HPIV3 was recognized post factum on an oncology pediatric unit in a major teaching hospital. This raised concern about the possibility of a future more serious outbreak. Weaknesses in existing systems were identified and a new dedicated respiratory virus monitoring system introduced.  Pediatric oncology units require sophisticated systems for early identification of potentially life-threatening viral outbreaks

    Isolation and characterisation of Leishmania donovani protein antigens from urine of visceral leishmaniasis patients.

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    Diagnosis of visceral leishmaniasis (VL) relies on invasive and risky aspirate procedures, and confirmation of cure after treatment is unreliable. Detection of Leishmania donovani antigens in urine has the potential to provide both a non-invasive diagnostic and a test of cure. We searched for L. donovani antigens in urine of VL patients from India and Sudan to contribute to the development of urine antigen capture immunoassays. VL urine samples were incubated with immobilised anti-L. donovani polyclonal antibodies and captured material was eluted. Sudanese eluted material and concentrated VL urine were analysed by western blot. Immunocaptured and immunoreactive material from Indian and Sudanese urine was submitted to mass spectrometry for protein identification. We identified six L. donovani proteins from VL urine. Named proteins were 40S ribosomal protein S9, kinases, and others were hypothetical. Thirty-three epitope regions were predicted with high specificity in the 6 proteins. Of these, 20 were highly specific to Leishmania spp. and are highly suitable for raising antibodies for the subsequent development of an antigen capture assay. We present all the identified proteins and analysed epitope regions in full so that they may contribute to the development of non-invasive immunoassays for this deadly disease

    GOBLET: the Global Organisation for Bioinformatics Learning, Education and Training

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    In recent years, high-throughput technologies have brought big data to the life sciences. The march of progress has been rapid, leaving in its wake a demand for courses in data analysis, data stewardship, computing fundamentals, etc., a need that universities have not yet been able to satisfy--paradoxically, many are actually closing "niche" bioinformatics courses at a time of critical need. The impact of this is being felt across continents, as many students and early-stage researchers are being left without appropriate skills to manage, analyse, and interpret their data with confidence. This situation has galvanised a group of scientists to address the problems on an international scale. For the first time, bioinformatics educators and trainers across the globe have come together to address common needs, rising above institutional and international boundaries to cooperate in sharing bioinformatics training expertise, experience, and resources, aiming to put ad hoc training practices on a more professional footing for the benefit of all

    Visceral Leishmaniasis IgG1 Rapid Monitoring of Cure vs. Relapse, and Potential for Diagnosis of Post Kala-Azar Dermal Leishmaniasis.

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    Background: There is a recognized need for an improved diagnostic test to assess post-chemotherapeutic treatment outcome in visceral leishmaniasis (VL) and to diagnose post kala-azar dermal leishmaniasis (PKDL). We previously demonstrated by ELISA and a prototype novel rapid diagnostic test (RDT), that high anti-Leishmania IgG1 is associated with post-treatment relapse versus cure in VL. Methodology: Here, we further evaluate this novel, low-cost RDT, named VL Sero K-SeT, and ELISA for monitoring IgG1 levels in VL patients after treatment. IgG1 levels against L. donovani lysate were determined. We applied these assays to Indian sera from cured VL at 6 months post treatment as well as to relapse and PKDL patients. Sudanese sera from pre- and post-treatment and relapse were also tested. Results: Of 104 paired Indian sera taken before and after treatment for VL, when deemed clinically cured, 81 (77.9%) were positive by VL Sero K-SeT before treatment; by 6 months, 68 of these 81 (84.0%) had a negative or reduced RDT test line intensity. ELISAs differed in positivity rate between pre- and post-treatment (p = 0.0162). Twenty eight of 33 (84.8%) Indian samples taken at diagnosis of relapse were RDT positive. A comparison of Indian VL Sero K-SeT data from patients deemed cured and relapsed confirmed that there was a significant difference (p < 0.0001) in positivity rate for the two groups using this RDT. Ten of 17 (58.8%) Sudanese sera went from positive to negative or decreased VL Sero K-SeT at the end of 11-30 days of treatment. Forty nine of 63 (77.8%) PKDL samples from India were positive by VL Sero K-SeT. Conclusion: We have further shown the relevance of IgG1 in determining clinical status in VL patients. A positive VL Sero K-SeT may also be helpful in supporting diagnosis of PKDL. With further refinement, such as the use of specific antigens, the VL Sero K-SeT and/or IgG1 ELISA may be adjuncts to current VL control programmes

    Search for dark matter produced in association with bottom or top quarks in √s = 13 TeV pp collisions with the ATLAS detector

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    A search for weakly interacting massive particle dark matter produced in association with bottom or top quarks is presented. Final states containing third-generation quarks and miss- ing transverse momentum are considered. The analysis uses 36.1 fb−1 of proton–proton collision data recorded by the ATLAS experiment at √s = 13 TeV in 2015 and 2016. No significant excess of events above the estimated backgrounds is observed. The results are in- terpreted in the framework of simplified models of spin-0 dark-matter mediators. For colour- neutral spin-0 mediators produced in association with top quarks and decaying into a pair of dark-matter particles, mediator masses below 50 GeV are excluded assuming a dark-matter candidate mass of 1 GeV and unitary couplings. For scalar and pseudoscalar mediators produced in association with bottom quarks, the search sets limits on the production cross- section of 300 times the predicted rate for mediators with masses between 10 and 50 GeV and assuming a dark-matter mass of 1 GeV and unitary coupling. Constraints on colour- charged scalar simplified models are also presented. Assuming a dark-matter particle mass of 35 GeV, mediator particles with mass below 1.1 TeV are excluded for couplings yielding a dark-matter relic density consistent with measurements

    Effect of angiotensin-converting enzyme inhibitor and angiotensin receptor blocker initiation on organ support-free days in patients hospitalized with COVID-19

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    IMPORTANCE Overactivation of the renin-angiotensin system (RAS) may contribute to poor clinical outcomes in patients with COVID-19. Objective To determine whether angiotensin-converting enzyme (ACE) inhibitor or angiotensin receptor blocker (ARB) initiation improves outcomes in patients hospitalized for COVID-19. DESIGN, SETTING, AND PARTICIPANTS In an ongoing, adaptive platform randomized clinical trial, 721 critically ill and 58 non–critically ill hospitalized adults were randomized to receive an RAS inhibitor or control between March 16, 2021, and February 25, 2022, at 69 sites in 7 countries (final follow-up on June 1, 2022). INTERVENTIONS Patients were randomized to receive open-label initiation of an ACE inhibitor (n = 257), ARB (n = 248), ARB in combination with DMX-200 (a chemokine receptor-2 inhibitor; n = 10), or no RAS inhibitor (control; n = 264) for up to 10 days. MAIN OUTCOMES AND MEASURES The primary outcome was organ support–free days, a composite of hospital survival and days alive without cardiovascular or respiratory organ support through 21 days. The primary analysis was a bayesian cumulative logistic model. Odds ratios (ORs) greater than 1 represent improved outcomes. RESULTS On February 25, 2022, enrollment was discontinued due to safety concerns. Among 679 critically ill patients with available primary outcome data, the median age was 56 years and 239 participants (35.2%) were women. Median (IQR) organ support–free days among critically ill patients was 10 (–1 to 16) in the ACE inhibitor group (n = 231), 8 (–1 to 17) in the ARB group (n = 217), and 12 (0 to 17) in the control group (n = 231) (median adjusted odds ratios of 0.77 [95% bayesian credible interval, 0.58-1.06] for improvement for ACE inhibitor and 0.76 [95% credible interval, 0.56-1.05] for ARB compared with control). The posterior probabilities that ACE inhibitors and ARBs worsened organ support–free days compared with control were 94.9% and 95.4%, respectively. Hospital survival occurred in 166 of 231 critically ill participants (71.9%) in the ACE inhibitor group, 152 of 217 (70.0%) in the ARB group, and 182 of 231 (78.8%) in the control group (posterior probabilities that ACE inhibitor and ARB worsened hospital survival compared with control were 95.3% and 98.1%, respectively). CONCLUSIONS AND RELEVANCE In this trial, among critically ill adults with COVID-19, initiation of an ACE inhibitor or ARB did not improve, and likely worsened, clinical outcomes. TRIAL REGISTRATION ClinicalTrials.gov Identifier: NCT0273570
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