872 research outputs found
New methods for finding disease-susceptibility genes: impact and potential
Improved techniques for defining disease-gene location and evaluating the biological candidacy of regional transcripts will hasten disease-gene discovery
Salt marsh resilience to sea-level rise and increased storm intensity
Salt marshes are important ecosystems but their resilience to sea-level rise and possible increases in storm intensity is largely uncertain. The current paradigm is that a positive sediment budget supports the survival and accretion of salt marshes while sediment deprivation causes marsh degradation. However, few studies have investigated the combined impact of sea-level rise and increased storm intensity on the sediment budget of a salt marsh. This study investigates marsh resilience under the combined impact of various storm surge (0 m, 0.25 m, 0.5 m, 1.0 m, 2.0 m, 3.0 m and 4.0 m) and sea-level (+0 m, +0.3 m, +0.5 m, +0.8 m and + 1.0 m) scenarios by using a sediment budget approach and the hydrodynamic model Delft3D. The Ribble Estuary, North-West England, whose salt marshes have been anthropogenically restored and have a high economic and environmental value, has been chosen as test case. We conclude that storm surges can positively contribute to the resilience of the salt marsh and estuarine system by promoting flood dominance and by triggering a net import of sediment. Conversely, sea-level rise can threaten the stability of the marsh by promoting ebb dominance and triggering a net export of sediment. Our results suggest that storm surges have a general tendency to counteract the decrease in sediment budget caused by sea-level rise. The timing of the storm surge relative to high or low tide, the duration of the surge, the change in tidal range and vegetation presence can also cause minor changes in the sediment budget
Electron Amplification in Diamond
We report on recent progress toward development of secondary emission ''amplifiers'' for photocathodes. Secondary emission gain of over 300 has been achieved in transmission mode and emission mode for a variety of diamond samples. Techniques of sample preparation, including hydrogenation to achieve negative electron affinity (NEA), have been adapted to this application
XPS and UHV AFM Analysis of the K2CsSb Photocathodes Growth
Next generation light sources, based on Energy Recovery Linac and Free Electron Laser technology will rely on photoinjector based electron sources. Successful operation of such sources requires reliable photocathodes with long operational life, uniform and high quantum efficiency, low thermal emittance and low dark current. The goal of this project is to construct a cathode which meets these requirements. Advances in photocathode research must take a combined effort. The materials have to be analyzed by means of chemical composition, surface structure and these findings have to be correlated to the quantum efficiency and performance in the injector. The presented work focuses on the chemical composition and surface structure of K2CsSb photocathodes. The XPS and AFM measurements were performed at the Center of Functional Nanomaterials at BNL. K2CsSb photocathodes were grown under UHV conditions. The components were adsorbed one at a time and after each growth step the corresponding XPS spectra was taken. During growth the quantum efficiency was recorded. As last step the sample was moved into the AFM without exposure to air to determine the surface roughnes
Dataset of results from numerical simulations of increased storm intensity in an estuarine salt marsh system
This article contains data outlining the effects of increased storm intensity on estuarine salt marshes, previously evaluated in Pannozzo et al. (2021), using the Ribble Estuary, in North West England, as a case study. The hydrodynamic model Delft3D was used to simulate various surge height scenarios and evaluate the effects of increasing surge height on the sediment budget of the system. The data shows that an increase in storm intensity (i.e. surge height) promotes flood dominance and triggers a net import of sediment, positively contributing to the sediment budget of the marsh platform and the estuarine system. The timing of the storm surge relative to high or low tide, the duration of the surge and the presence of vegetation do not cause major changes in the sediment budget. This dataset could be used to evaluate how increased storm intensity might influence the sediment budget of estuaries in comparison to other types of coastal systems (e.g., bays) to illustrate how the response of salt marshes to increased storm intensity varies with a change in the hydrodynamics and sediment delivery dynamics of the system
Storm sediment contribution to salt marsh accretion and expansion
Salt marshes are ecosystems with significant economic and environmental value. However, the accelerating rate of sea-level rise is a significant threat to these ecosystems. Storms significantly contribute to the sediment budget of salt marshes, playing a critical role in salt marsh survival to sea-level rise. There are, however, uncertainties on the extent to which storms contribute sediments to different areas of marsh platforms (e.g., outer marsh vs marsh interior) and on the sediment sources that storms draw on (e.g., offshore vs nearshore). This study uses field analyses from an eight-month field campaign in the Ribble Estuary, North-West England, to understand storms' influence on the sediment supply to different marsh areas and whether storms can deliver new material onto the salt marsh platform which would otherwise not be sourced in fair-weather conditions. Field data from sediment traps indicate that storm activity caused an increase in inorganic sediment supply to the whole salt marsh platform, especially benefitting the marsh interior. Geochemistry and particle size distribution analysis indicate that the majority of the sediment supplied to the salt marsh platform during the stormy periods was generated by an increase in erosion and resuspension of mudflat and tidal creek sediments, while only a minimal contribution was given by the sediments transported from outside the intertidal system. This suggests that, in the long term, storms will promote salt marsh vertical accretion but might simultaneously reduce the overall larger-scale sediment availability with implications for the marsh lateral retreat
A behavioural change package to prevent hand dermatitis in nurses working in the national health service (the SCIN trial): study protocol for a cluster randomised controlled trial
BACKGROUND: Hand dermatitis can be a serious health problem in healthcare workers. While a range of skin care strategies and policy directives have been developed in recent years to minimise the risk, their effectiveness and cost-effectiveness remain unclear. Evidence now suggests that psychological theory can facilitate behaviour change with respect to improved hand care practices. Therefore, we will test the hypothesis that a behavioural change intervention to improve hand care, based on the Theory of Planned Behaviour and implementation intentions, coupled with provision of hand moisturisers, can produce a clinically useful reduction in the occurrence of hand dermatitis, when compared to standard care, among nurses working in the UK National Health Service (NHS) who are particularly at risk. Secondary aims will be to assess impacts on participants’ beliefs and behaviour regarding hand care. In addition, we will assess the cost-effectiveness of the intervention in comparison with normal care. METHODS/DESIGN: We will conduct a cluster randomised controlled trial at 35 NHS hospital trusts/health boards/universities, focussing on student nurses with a previous history of atopic disease or hand eczema and on nurses in intensive care units. Nurses at ‘intervention-light’ sites will be managed according to what would currently be regarded as best practice, with provision of an advice leaflet about optimal hand care to prevent hand dermatitis and encouragement to contact their occupational health (OH) department early if hand dermatitis occurs. Nurses at ‘intervention-plus’ sites will additionally receive a behavioural change programme (BCP) with on-going active reinforcement of its messages, and enhanced provision of moisturising cream. The impact of the interventions will be compared using information collected by questionnaires and through standardised photographs of the hands and wrists, collected at baseline and after 12 months follow-up. In addition, we will assemble relevant economic data for an analysis of costs and benefits, and collect information from various sources to evaluate processes. Statistical analysis will be by multi-level regression modelling to allow for clustering by site, and will compare the prevalence of outcome measures at follow-up after adjustment for values at baseline. The principal outcome measure will be the prevalence of visible hand dermatitis as assessed by the study dermatologists. In addition, several secondary outcome measures will be assessed. DISCUSSION: This trial will assess the clinical and cost effectiveness of an intervention to prevent hand dermatitis in nurses in the United Kigdom. TRIAL REGISTRATION: ISRCTN53303171: date of registration, 21 June 2013
An Integration of Numerical Modeling and Paleoenvironmental Analysis Reveals the Effects of Embankment Construction on Long‐Term Salt Marsh Accretion
There are still numerous uncertainties over the influence of anthropogenic interventions on salt marsh dynamics. This study uses the Ribble Estuary as a test case and an integrated approach of numerical modeling and paleoenvironmental analysis to investigate the contribution of embankment construction to long-term marsh accretion. Accretion rates derived using optically stimulated luminescence dating (OSL) were combined with a multi-proxy paleoenvironmental investigation on sediment cores extracted from the salt marsh, the mobile seafloor of the central Irish Sea and the river catchment area. These analyses provided a first evolutionary perspective on the Ribble Estuary preceding any management interventions. The paleoenvironmental analyses were then compared to simulations conducted using the hydrodynamic model Delft3D to investigate the effects of embankment construction on estuarine hydrodynamics and morphodynamics of the salt marsh over the period constrained by the OSL. The numerical simulations showed that embankments were responsible for an overall intensification of the ebb currents in the system which promoted sediment export. The paleoenvironmental analyses showed that the marsh has been accreting at a rate of 4.61 to 0.86 cm yr−1 over the last ca. 190 years and that the high sedimentation rate was caused by a naturally high rate of sediment supply. The model-data integration showed that the effects of the embankment construction on sediment transport did not compromise the long-term resilience of the salt marsh because of the high rates of sediment supply and the river dredging which enhanced the flood dominance of the tide near the tidal flat
Novel luminescence diagnosis of storm deposition across intertidal environments.
Salt marshes provide valuable nature-based, low-cost defences protecting against coastal flooding and erosion. Storm sedimentation can improve the resilience of salt marshes to accelerating rates of sea-level rise, which poses a threat to salt marsh survival worldwide. It is therefore important to be able to accurately detect the frequency of storm activity in longer-term sediment records to quantify how storms contribute to salt marsh resilience. Luminescence is able to infer how long mineral grains were exposed to sunlight prior to burial (e.g., the presence or absence of sediment processing). This study used sediment cores collected from the Ribble Estuary, North West England, to show that luminescence properties of sand-sized K-feldspar grains can diagnose the differential modes of deposition across intertidal settings (i.e., sandflat, mudflat and salt marsh) in longer-term sediment records by detecting the variability in sediment bleaching potential between settings (i.e., sediment exposure to sunlight), thus establishing a framework for the interpretation of luminescence properties of intertidal sediments. It then used modern sediment samples collected before and after a storm event to show how such properties can diagnose changes in sediment processing (i.e., bleaching potential) of mudflat sediments caused by storm activity, despite no changes in sediment composition being recorded by geochemical and particle size distribution analyses. This new luminescence approach can be applied to longer-term sediment records to reveal (and date) changes in the environment of deposition and/or depositional dynamics where there is no obvious stratigraphic evidence of such
A behaviour change package to prevent hand dermatitis in nurses working in health care: the SCIN cluster RCT
BACKGROUND: Although strategies have been developed to minimise the risk of occupational hand dermatitis in nurses, their clinical effectiveness and cost-effectiveness remain unclear. OBJECTIVES: The Skin Care Intervention in Nurses trial tested the hypothesis that a behaviour change package intervention, coupled with provision of hand moisturisers, could reduce the point prevalence of hand dermatitis when compared with standard care among nurses working in the NHS. The secondary aim was to assess the impact of the intervention on participants' beliefs and behaviour regarding hand care, and the cost-effectiveness of the intervention in comparison with normal care. DESIGN: Cluster randomised controlled trial. SETTING: Thirty-five NHS hospital trusts/health boards/universities. PARTICIPANTS: First-year student nurses with a history of atopic tendency, and full-time intensive care unit nurses. INTERVENTION: Sites were randomly allocated to be 'intervention plus' or 'intervention light'. Participants at 'intervention plus' sites received access to a bespoke online behaviour change package intervention, coupled with personal supplies of moisturising cream (student nurses) and optimal availability of moisturising cream (intensive care unit nurses). Nurses at 'intervention light' sites received usual care, including a dermatitis prevention leaflet. MAIN OUTCOME MEASURE: The difference between intervention plus and intervention light sites in the change of point prevalence of visible hand dermatitis was measured from images taken at baseline and at follow-up. RANDOMISATION: Fourteen sites were randomised to the intervention plus arm, and 21 sites were randomised to the intervention light arm. BLINDING: The participants, trial statistician, methodologist and the dermatologists interpreting the hand photographs were blinded to intervention assignment. NUMBERS ANALYSED: An intention-to-treat analysis was conducted on data from 845 student nurses and 1111 intensive care unit nurses. RESULTS: The intention-to-treat analysis showed no evidence that the risk of developing dermatitis was greater in the intervention light group than in the intervention plus group (student nurses: odds ratio 1.25, 95% confidence interval 0.59 to 2.69; intensive care unit nurses: odds ratio 1.41, 95% confidence interval 0.81 to 2.44). Both groups had high levels of baseline beliefs about the benefits of using hand moisturisers before, during and after work. The frequency of use of hand moisturisers before, during and after shifts was significantly higher in the intensive care unit nurses in the intervention plus arm at follow-up than in the comparator group nurses. For student nurses, the intervention plus group mean costs were £2 lower than those for the comparator and 0.00002 more quality-adjusted life-years were gained. For intensive care unit nurses, costs were £4 higher and 0.0016 fewer quality-adjusted life-years were gained. HARMS: No adverse events were reported. LIMITATIONS: Only 44.5% of participants in the intervention plus arm accessed the behaviour change package. CONCLUSION: The intervention did not result in a statistically significant decrease in the prevalence of hand dermatitis in the intervention plus group. FUTURE WORK: Participants had a high level of baseline beliefs about the importance of using hand moisturisers before, during and after work. Future research should focus on how workplace culture can be changed in order for that knowledge to be actioned. TRIAL REGISTRATION: Current Controlled Trials ISRCTN53303171. FUNDING: This project was funded by the National Institute for Health Research (NIHR) Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 23, No. 58. See the NIHR Journals Library website for further project information
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