694 research outputs found

    A Comparative Study of the Magnitude, Frequency and Distribution of Intense Rainfall in the United Kingdom

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    During the 1960s, a study was made of the magnitude, frequency and distribution of intense rainfall over the UK, employing data from more than 120 daily-read rain gauges covering the period 1911 to 1960. Using the same methodology, that study was recently updated utilizing data for the period 1961 to 2006 for the same gauges, or from those nearby. This paper describes the techniques applied to ensure consistency of data and statistical modelling. It presents a comparison of patterns of extreme rainfalls for the two periods and discusses the changes that have taken place. Most noticeably, increases up to 20% have occurred in the north west of the country and in parts of East Anglia. There have also been changes in other areas, including decreases of the same magnitude over central England. The implications of these changes are considered

    La componente de precipitaciĂłn en el balance hĂ­drico: sus problemas y perspectivas

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    Upgrading the Seismic Resistance of Stevens Creek Dam

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    Stevens Creek Darn is a rolled earthfill structure with a height of about 120 feet. A seismic safety evaluation in 1978 concluded that the darn would probably be severely damaged if subjected to a maximum credible earthquake originating on the nearby San Andreas fault. Normal reservoir operation was immediately restricted, pending decisions as to the fate of the project. Conceptual design studies were completed in 1982 to identify the most promising alternative remedial concepts. The most promising concepts were chosen and final design of modifications to the dam and its appurtenant hydraulic structures were completed in 1984. Modification of the darn was completed in 1986, involving the placement of massive buttresses on both the upstream and downstream slopes and installation of internal drains to control the phreatic line. This required extension of the existing outlet conduit and construction of new inlet and outlet control structures

    How and when of eyelid reconstruction using autologous transplantation

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    Reconstructive surgery of the eyelid after tumor excision, trauma or other causes can be challenging, especially due to the complexities of the anatomic structures and to the necessity of both functional and aesthetic successful outcomes. The aim of this minireview was to investigate the use of tissue transplantation in eyelid reconstruction. Surgical procedures are various, based on the use of both flaps, pedicled or free, and grafts, in order to guarantee adequate tissue reconstruction and blood supply, which are necessary for correct healing. Common techniques normally include the use of local tissues, combining non-vascularized grafts with a vascularized flap for the two lamellae repair, to attempt a reconstruction similar to the original anatomy. When defects are too wide, vast, deep, and complex or when no adjacent healthy tissues are available, distant area tissues need to be recruited as free flaps or grafts and paired with mucosal layer reconstruction. With regards to the anterior lamella, full thickness skin grafts are commonly preferred. With regards to the reconstruction of posterior lamella, there are different graft options, which include conjunctival or tarsoconjunctival, mucosal or palatal or cartilaginous grafts usually combined with local flaps. Free flap transplantation, normally reserved for rare select cases, include the use of the radial forearm and anterolateral flaps combined with mucosal grafts, which are surgical options currently reported in the literature

    Seismic Deformation of Dams by Correlative Methods

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    Analyses are presented of the anticipated earthquake performance of three generally similar earth dams, situated in a seismically active area of northern California. The series of analyses illustrates a cost-effective approach which involved full-scale finite element analyses of one dam, and the use of limited dynamic analysis techniques and correlations to evaluate the other two. The simplified techniques were applied only after testing them against the finite element analyses, information is also presented on how the results of simplified and full-scale dynamic analysis procedures correlate

    Web-based counseling for problem gambling: exploring motivations and recommendations

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    Background:For highly stigmatized disorders, such as problem gambling, Web-based counseling has the potential to&nbsp;address common barriers to treatment, including issues of shame and stigma. Despite the exponential&nbsp;growth in the uptake of immediate synchronous Web-based counseling (ie, provided without&nbsp;appointment), little is known about why people choose this service over other modes of treatment.Objective:The aim of the current study was to determine motivations for choosing and recommending Web-based&nbsp;counseling over telephone or face-to-face services.Methods:The study involved 233 Australian participants who had completed an online counseling session for&nbsp;problem gambling on the Gambling Help Online website between November 2010 and February 2012.&nbsp;Participants were all classified as problem gamblers, with a greater proportion of males (57.4%) and&nbsp;60.4% younger than 40 years of age. Participants completed open-ended questions about their reasons&nbsp;for choosing online counseling over other modes (ie, face-to-face and telephone), as well as reasons for&nbsp;recommending the service to others.Results:A content analysis revealed 4 themes related to confidentiality/anonymity (reported by 27.0%),&nbsp;convenience/accessibility (50.9%), service system access (34.2%), and a preference for the therapeutic&nbsp;medium (26.6%). Few participants reported helpful professional support as a reason for accessing&nbsp;counseling online, but 43.2% of participants stated that this was a reason for recommending the service.Those older than 40 years were more likely than younger people in the sample to use Web-based&nbsp;counseling as an entry point into the service system (&lt;italic&gt;P&lt;/italic&gt;=.045), whereas those engaged in&nbsp;nonstrategic gambling (eg, machine gambling) were more likely to access online counseling as an entry&nbsp;into the service system than those engaged in strategic gambling (ie, cards, sports;&nbsp;&lt;italic&gt;P&lt;/italic&gt;=.01). Participants older than 40 years were more likely to recommend the service&nbsp;because of its potential for confidentiality and anonymity (&lt;italic&gt;P&lt;/italic&gt;=.04), whereas those&nbsp;younger than 40 years were more likely to recommend the service due to it being helpful&nbsp;(&lt;italic&gt;P&lt;/italic&gt;=.02).Conclusions:This study provides important information about why online counseling for gambling is attractive to&nbsp;people with problem gambling, thereby informing the development of targeted online programs,&nbsp;campaigns, and promotional material.</div

    Jet stream variability in a polar warming scenario – a laboratory perspective

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    We report on a set of laboratory experiments to investigate the effect of polar warming on the mid-latitude jet stream. Our results show that a progressive decrease in the meridional temperature difference slows down the eastward propagation of the jet stream and complexifies its structure. Temperature variability decreases in relation to the laboratory “Arctic warming” only at locations representing the Earth's polar and mid-latitudes, which are influenced by the jet stream, whilst such a trend is reversed in the subtropical region south of the simulated jet. The reduced variability results in narrower temperature distributions and hence milder extreme events. However, our experiments also show that the frequency of such events increases at polar and mid-latitudes with decreased meridional temperature difference, whilst it decreases towards the subtropics. Despite missing land–sea contrast in the laboratory model, we find qualitatively similar trends of temperature variability and extreme events in the experimental data and the National Centers for Environmental Prediction (NCEP) reanalysis data

    Impact of COVID-19 pandemic on ophthalmic presentations to an Australian outer metropolitan and rural emergency department: a retrospective comparative study.

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    BACKGROUND: To analyse ophthalmic presentations to an outer metropolitan and a rural emergency department (ED) during the first wave of the COVID-19 pandemic in New South Wales (NSW), Australia. METHODS: A retrospective comparative study of ophthalmic emergency presentations to Campbelltown Hospital (fifth busiest NSW metropolitan ED; population 310,000) and Bowral and District Hospital (rural ED; population 48,000) before and during COVID-19 was conducted. Patient demographics, triage category, referral source, diagnosis, length of stay, departure status, and follow-up location were assessed from coding data between March 1st to May 31st in 2019 and 2020, corresponding to the peak case numbers and restrictions during the first wave of the COVID-19 pandemic in NSW. Differences before and during COVID-19 were analysed using chi-squared tests or independent sample t-tests. RESULTS: There was no change in ophthalmic presentations at Campbelltown (n = 228 in 2019 vs. n = 232 in 2020; + 1.75%, p = 0.12) and an increase at Bowral (n = 100 in 2019 vs. n = 111 in 2020; + 11%, p < 0.01) during COVID-19. Urgent ophthalmic presentations (Triage Category 3) decreased at Bowral (p = 0.0075), while non-urgent ophthalmic presentations (Triage Category 5) increased at both hospitals (Campbelltown p < 0.05, Bowral p < 0.01). CONCLUSIONS: There was no change in the total number of ophthalmic presentations to an outer metropolitan and an increase to a rural ED during the first wave of the COVID-19 pandemic in New South Wales, Australia. A change in the type of ophthalmic presentations at these peripheral EDs suggest that a high demand for ophthalmic services remained despite the pandemic and its associated gathering and movement restrictions. A flexible healthcare delivery strategy, such as tele-ophthalmology, may optimise patient care during and after COVID-19

    Water security in South Africa: perceptions on public expectations and municipal obligations, governance and water re-use

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    South Africa is a water-scarce country with increasing pressure on its water resources. Urgent interventions are needed to protect water security within this rapidly developing country. This paper reports on an interdisciplinary Water Security Colloquium, convened by the South African Young Academy of Science in 2014. A selected group of water professionals from academia, civil society and local government was brought together to discuss water security under three focus themes: ‘public expectations and municipal obligations’, ‘water security and governance: challenges and advances’, and ‘water re-use: health and infrastructural considerations’. Participant perceptions were generated using a focus group methodology, combined with participatory data collection methods. Under each theme, inputs were categorised as ‘challenges’, ‘gaps in knowledge’, and ‘solutions/recommendations’ and these inputs were thereafter ranked in order of importance via a ‘voting’ process. Major challenges perceived included a lack of both skills and political will in government, a need to restore citizen trust in government intention and capability to deliver water-related services, and a failure to up-scale existing water re-use technology. Participants identified understanding of the process and implications of the Green and Blue Drop Programmes, knowledge transfer to the public, and the role of educators as major knowledge gaps. The top suggestions proposed included creating public awareness around and buy-in to initiatives to improve water security, accessible and user-friendly conversion of research results to implementation, and ensuring an active role for educators in creating awareness around water security. In view of the concerns identified, participants suggested as potential solutions: improving government and public understanding around water issues, incentivising water re-use and conservation, introducing rising block tariffs and improving human capacity development in the water sector. Developing the ecological infrastructure that protects both quantity and quality of water and building strong partnerships among all stakeholders were also recognised as key.Keywords: capacity development, education, governance, water security, water re-use, water conservation, local governmen

    Water quality modelling of the Mekong River basin: climate change and socioeconomics drive flow and nutrient flux changes to the Mekong Delta

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    The Mekong delta is recognised as one of the world's most vulnerable mega-deltas, being subject to a range of environmental pressures including sea level rise, increasing population, and changes in flows and nutrients from its upland catchment. With changing climate and socioeconomics there is a need to assess how the Mekong catchment will be affected in terms of the delivery of water and nutrients into the delta system. Here we apply the Integrated Catchment model (INCA) to the whole Mekong River Basin to simulate flow and water quality, including nitrate, ammonia, total phosphorus and soluble reactive phosphorus. The impacts of climate change on all these variables have been assessed across 24 river reaches ranging from the Himalayas down to the delta in Vietnam. We used the UK Met Office PRECIS regionally coupled climate model to downscale precipitation and temperature to the Mekong catchment. This was accomplished using the Global Circulation Model GFDL-CM to provide the boundary conditions under two carbon control strategies, namely representative concentration pathways (RCP) 4.5 and a RCP 8.5 scenario. The RCP 4.5 scenario represents the carbon strategy required to meet the Paris Accord, which aims to limit peak global temperatures to below a 2 °C rise whilst seeking to pursue options that limit temperature rise to 1.5 °C. The RCP 8.5 scenario is associated with a larger 3–4 °C rise. In addition, we also constructed a range of socio-economic scenarios to investigate the potential impacts of changing population, atmospheric pollution, economic growth and land use change up to the 2050s. Results of INCA simulations indicate increases in mean flows of up to 24%, with flood flows in the monsoon period increasing by up to 27%, but with increasing periods of drought up to 2050. A shift in the timing of the monsoon is also simulated, with a 4 week advance in the onset of monsoon flows on average. Decreases in nitrogen and phosphorus concentrations occur primarily due to flow dilution, but fluxes of these nutrients also increase by 5%, which reflects the changing flow, land use change and population changes
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