Noble gases confirm plume-related mantle degassing beneath Southern Africa.

Southern Africa is characterised by unusually elevated topography and abnormal heat flow. This can be explained by thermal perturbation of the mantle, but the origin of this is unclear. Geophysics has not detected a thermal anomaly in the upper mantle and there is no geochemical evidence of an asthenosphere mantle contribution to the Cenozoic volcanic record of the region. Here we show that natural CO2 seeps along the Ntlakwe-Bongwan fault within KwaZulu-Natal, South Africa, have C-He isotope systematics that support an origin from degassing mantle melts. Neon isotopes indicate that the melts originate from a deep mantle source that is similar to the mantle plume beneath Réunion, rather than the convecting upper mantle or sub-continental lithosphere. This confirms the existence of the Quathlamba mantle plume and importantly provides the first evidence in support of upwelling deep mantle beneath Southern Africa, helping to explain the regions elevation and abnormal heat flow.

An approach for the identification of exemplar sites for scaling up targeted field observations of benthic biogeochemistry in heterogeneous environments.

Continental shelf sediments are globally important for biogeochemical activity. Quantification of shelf-scale stocks and fluxes of carbon and nutrients requires the extrapolation of observations made at limited points in space and time. The procedure for selecting exemplar sites to form the basis of this up-scaling is discussed in relation to a UK-funded research programme investigating biogeochemistry in shelf seas. A three-step selection process is proposed in which (1) a target area representative of UK shelf sediment heterogeneity is selected, (2) the target area is assessed for spatial heterogeneity in sediment and habitat type, bed and water column structure and hydrodynamic forcing, and (3) study sites are selected within this target area encompassing the range of spatial heterogeneity required to address key scientific questions regarding shelf scale biogeochemistry, and minimise confounding variables. This led to the selection of four sites within the Celtic Sea that are significantly different in terms of their sediment, bed structure, and macrofaunal, meiofaunal and microbial community structures and diversity, but have minimal variations in water depth, tidal and wave magnitudes and directions, temperature and salinity. They form the basis of a research cruise programme of observation, sampling and experimentation encompassing the spring bloom cycle. Typical variation in key biogeochemical, sediment, biological and hydrodynamic parameters over a pre to post bloom period are presented, with a discussion of anthropogenic influences in the region. This methodology ensures the best likelihood of site-specific work being useful for up-scaling activities, increasing our understanding of benthic biogeochemistry at the UK-shelf scale.

Oxygen dynamics in shelf seas sediments incorporating seasonal variability.

Shelf sediments play a vital role in global biogeochemical cycling and are particularly important areas of oxygen consumption and carbon mineralisation. Total benthic oxygen uptake, the sum of diffusive and faunal mediated uptake, is a robust proxy to quantify carbon mineralisation. However, oxygen uptake rates are dynamic, due to the diagenetic processes within the sediment, and can be spatially and temporally variable. Four benthic sites in the Celtic Sea, encompassing gradients of cohesive to permeable sediments, were sampled over four cruises to capture seasonal and spatial changes in oxygen dynamics. Total oxygen uptake (TOU) rates were measured through a suite of incubation experiments and oxygen microelectrode profiles were taken across all four benthic sites to provide the oxygen penetration depth and diffusive oxygen uptake (DOU) rates. The difference between TOU and DOU allowed for quantification of the fauna mediated oxygen uptake and diffusive uptake. High resolution measurements showed clear seasonal and spatial trends, with higher oxygen uptake rates measured in cohesive sediments compared to the permeable sediment. The significant differences in oxygen dynamics between the sediment types were consistent between seasons, with increasing oxygen consumption during and after the phytoplankton bloom. Carbon mineralisation in shelf sediments is strongly influenced by sediment type and seasonality.

Benthic pH gradients across a range of shelf sea sediment types linked to sediment characteristics and seasonal variability.

This study used microelectrodes to record pH profiles in fresh shelf sea sediment cores collected across a range of different sediment types within the Celtic Sea. Spatial and temporal variability was captured during repeated measurements in 2014 and 2015. Concurrently recorded oxygen microelectrode profiles and other sedimentary parameters provide a detailed context for interpretation of the pH data. Clear differences in profiles were observed between sediment type, location and season. Notably, very steep pH gradients exist within the surface sediments (10-20 mm), where decreases greater than 0.5 pH units were observed. Steep gradients were particularly apparent in fine cohesive sediments, less so in permeable sandier matrices. We hypothesise that the gradients are likely caused by aerobic organic matter respiration close to the sediment-water interface or oxidation of reduced species at the base of the oxic zone (NH4 +, Mn2+, Fe2+, S-). Statistical analysis suggests the variability in the depth of the pH minima is controlled spatially by the oxygen penetration depth, and seasonally by the input and remineralisation of deposited organic phytodetritus. Below the pH minima the observed pH remained consistently low to maximum electrode penetration (ca. 60 mm), indicating an absence of sub-oxic processes generating H+ or balanced removal processes within this layer. Thus, a climatology of sediment surface porewater pH is provided against which to examine biogeochemical processes. This enhances our understanding of benthic pH processes, particularly in the context of human impacts, seabed integrity, and future climate changes, providing vital information for modelling benthic response under future climate scenarios.

Comparing benthic biogeochemistry at a sandy and a muddy site in the Celtic Sea using a model and observations.

Results from a 1D setup of the European Regional Seas Ecosystem Model (ERSEM) biogeochemical model were compared with new observations collected under the UK Shelf Seas Biogeochemistry (SSB) programme to assess model performance and clarify elements of shelf-sea benthic biogeochemistry and carbon cycling. Observations from two contrasting sites (muddy and sandy) in the Celtic Sea in otherwise comparable hydrographic conditions were considered, with the focus on the benthic system. A standard model parameterisation with site-specific light and nutrient adjustments was used, along with modifications to the within-seabed diffusivity to accommodate the modelling of permeable (sandy) sediments. Differences between modelled and observed quantities of organic carbon in the bed were interpreted to suggest that a large part (>90%) of the observed benthic organic carbon is biologically relatively inactive. Evidence on the rate at which this inactive fraction is produced will constitute important information to quantify offshore carbon sequestration. Total oxygen uptake and oxic layer depths were within the range of the measured values. Modelled depth average pore water concentrations of ammonium, phosphate and silicate were typically 5-20% of observed values at the muddy site due to an underestimate of concentrations associated with the deeper sediment layers. Model agreement for these nutrients was better at the sandy site, which had lower pore water concentrations, especially deeper in the sediment. Comparison of pore water nitrate with observations had added uncertainty, as the results from process studies at the sites indicated the dominance of the anammox pathway for nitrogen removal; a pathway that is not included in the model. Macrofaunal biomasses were overestimated, although a model run with increased macrofaunal background mortality rates decreased macrofaunal biomass and improved agreement with observations. The decrease in macrofaunal biomass was compensated by an increase in meiofaunal biomass such that total oxygen demand remained within the observed range. The permeable sediment modification reproduced some of the observed behaviour of oxygen penetration depth at the sandy site. It is suggested that future development in ERSEM benthic modelling should focus on: (1) mixing and degradation rates of benthic organic matter, (2) validation of benthic faunal biomass against large scale spatial datasets, (3) incorporation of anammox in the benthic nitrogen cycle, and (4) further developments to represent permeable sediment processes.

Evidence for separatrix formation and sustainment with steady inductive helicity injection.

The first sustainment of toroidal plasma current of 50 kA at up to 3 times the injected currents, added in quadrature, using steady inductive helicity injection is described. Separatrix currents-currents not linking the helicity injectors-are sustained up to 40 kA. Decreases in the n=1 toroidal mode of the poloidal magnetic field at higher current amplifications indicate more quiescent, direct toroidal current drive. Results are achieved in HIT-SI (with a spheromak of major radius 0.3 m) during deuterium operations immediately after helium operation. These results represent a breakthrough in the development of this new current drive method for magnetic confinement fusion.

Convective and diffusive energetic particle losses induced by shear Alfvén waves in the ASDEX upgrade tokamak.

We present here the first phase-space characterization of convective and diffusive energetic particle losses induced by shear Alfvén waves in a magnetically confined fusion plasma. While single toroidal Alfvén eigenmodes (TAE) and Alfvén cascades (AC) eject resonant fast ions in a convective process, an overlapping of AC and TAE spatial structures leads to a large fast-ion diffusion and loss. Diffusive fast-ion losses have been observed with a single TAE above a certain threshold in the fluctuation amplitude.

Development of a toolkit and glossary to aid in the adaptation of health technology assessment (HTA) reports for use in different contexts.

OBJECTIVES: To develop a health technology assessment (HTA) adaptation toolkit and glossary of adaptation terms for use by HTA agencies within EU member states to support them in adapting HTA reports written for other contexts. METHODS: The toolkit and glossary were developed by a partnership of 28 HTA agencies and networks across Europe (EUnetHTA work package 5), led by the UK National Coordinating Centre for Health Technology Assessment (NCCHTA). Methods employed for the two resources were literature searching, a survey of adaptation experience, two rounds of a Delphi survey, meetings of the partnership and drawing on the expertise and experience of the partnership, two rounds of review, and two rounds of quality assurance testing. All partners were requested to provide input into each stage of development. RESULTS: The resulting toolkit is a collection of resources, in the form of checklists of questions on relevance, reliability and transferability of data and information, and links to useful websites, that help the user assess whether data and information in existing HTA reports can be adapted for a different setting. The toolkit is designed for the adaptation of evidence synthesis rather than primary research. The accompanying glossary provides descriptions of meanings for HTA adaptation terms from HTA agencies across Europe. It seeks to highlight differences in the use and understanding of each word by HTA agencies. The toolkit and glossary are available for use by all HTA agencies and can be accessed via www.eunethta.net/. CONCLUSIONS: These resources have been developed to help HTA agencies make better use of HTA reports produced elsewhere. They can be used by policy-makers and clinicians to aid in understanding HTA reports written for other contexts. The main implication of this work is that there is the potential for the adaptation of HTA reports and, if utilised, this should release resources to enable the development of further HTA reports. Recommendations for the further development of the toolkit include the potential to develop an interactive web-based version and to extend the toolkit to facilitate the adaptation of HTA reports on diagnostic testing and screening.

Autopsy after termination of pregnancy for fetal anomaly: retrospective cohort study.

OBJECTIVE: To study trends in termination of pregnancy for fetal anomaly over 10 years and to assess the contribution of autopsy to the final diagnosis and counselling after termination. DESIGN: Retrospective study with cases from a congenital anomaly register and a defined unselected population. DATA SOURCES: Pregnancies resulting in termination for fetal anomaly identified from the Oxford congenital anomaly register. Details about the prenatal diagnosis and autopsy findings were retrieved from case notes. RESULTS: Of the 57 258 deliveries, 309 (0.5%) were terminated because of prenatally diagnosed abnormality. There were 129/29 086 (0.4%) terminations for fetal anomaly carried out in 1991-5 and 180/28 172 (0.6%) in 1996-2000. The percentage of fetuses that underwent autopsy fell from 84% to 67%. Autopsy was performed in 132 cases identified by ultrasound scan, with no evidence for abnormal karyotype. In 95 (72%) the autopsy confirmed the suspected diagnosis and did not add important further information, two cases were not classified, and in 35 (27%) the autopsy added information that led to a refinement of the risk of recurrence (reduced in 17, increased in 18); in 11 of these 18 cases it was increased to a one in four risk. CONCLUSIONS: Though there has been an increase in the rate of terminations of pregnancy for fetal anomaly, there has been a decline in the autopsy rate. When a prenatal diagnosis was based on the results of a scan only, the addition of information from an autopsy by a specialist paediatric pathologist provided important information that changed the estimated risk of recurrence in 27% of cases and in 8% this was to a higher (one in four) risk.

Hospitalization for ambulatory care-sensitive conditions: a method for comparative access and quality studies using routinely collected statistics.

BACKGROUND: Appropriate and timely provision of ambulatory care is an important factor in maintaining population health and in avoiding unneccessary hospital use. This article describes conditions for which hospitalization rates have a strong and inverse relationship to access to high-quality ambulatory care. METHODS: Three panels of Canadian physicians following different consensus techniques selected conditions for which the relative risk of hospitalization is inversely related to ambulatory care access. PRINCIPAL FINDINGS: All panels identified asthma, angina pectoris, congestive heart failure, otitis media, gastric ulcer, pelvic inflammatory disease, malignant hypertension, and immunization-preventable infections as ambulatory care-sensitive admissions. These conditions strongly overlap with lists developed for similar purposes in the U.S. and England. INTERPRETATION: Ambulatory care-sensitive conditions represent an intermediate health outcome. They are distinct from inappropriate hospitalizations. They may be useful for measuring the impact of health care policy, and for performance measurement or audit.

A randomized controlled trial assessing the health economics of realtime teledermatology compared with conventional care: an urban versus rural perspective.

A randomized controlled trial was carried out to measure the cost-effectiveness of realtime teledermatology compared with conventional outpatient dermatology care for patients from urban and rural areas. One urban and one rural health centre were linked to a regional hospital in Northern Ireland by ISDN at 128 kbit/s. Over two years, 274 patients required a hospital outpatient dermatology referral--126 patients (46%) were randomized to a telemedicine consultation and 148 (54%) to a conventional hospital outpatient consultation. Of those seen by telemedicine, 61% were registered with an urban practice, compared with 71% of those seen conventionally. The clinical outcomes of the two types of consultation were similar--almost half the patients were managed after a single consultation with the dermatologist. The observed marginal cost per patient of the initial realtime teledermatology consultation was 52.85 Pounds for those in urban areas and 59.93 Pounds per patient for those from rural areas. The observed marginal cost of the initial conventional consultation was 47.13 Pounds for urban patients and 48.77 Pounds for rural patients. The total observed costs of teledermatology were higher than the costs of conventional care in both urban and rural areas, mainly because of the fixed equipment costs. Sensitivity analysis using a real-world scenario showed that in urban areas the average costs of the telemedicine and conventional consultations were about equal, while in rural areas the average cost of the telemedicine consultation was less than that of the conventional consultation.

A comparison of real-time and store-and-forward teledermatology: a cost-benefit study.

BACKGROUND: Increasing use of teledermatology should be based on demonstration of favourable accuracy and cost-benefit analysis for the different methods of use of this technique. Objectives To evaluate the clinical efficacy and cost-effectiveness of real-time and store-and-forward teledermatology. METHODS: Patients attended their own health centre and in the company of a general practitioner (GP) were seen by a hospital dermatologist over the videolink (real-time). Before the videolink consultation commenced, the GP took instant photographs of the skin lesion and posted them along with a standard referral letter to a different hospital dermatologist (store-and-forward). In total, 96 patients were seen by both real-time and store-and-forward teledermatology. Comparative diagnoses, clinical management plans, clinical outcomes and associated costs were made between the two types of teledermatology consultation. RESULTS: There was agreement between the videolink diagnosis and the still image diagnosis in 51% of cases. The same or similar management plan was recommended at both types of consultation in 44% of cases. Following the store-and-forward consultation the dermatologist recommended that 69% of patients required at least one hospital appointment compared with 45% of those patients seen in real-time. The net societal cost of the initial real-time consultation was pound132.10 per patient compared with £26.90 per patient for the initial store-and-forward consultation. CONCLUSIONS: The store-and-forward consultation was cheaper, but less clinically efficient, compared with the real-time consultation. The absence of interaction in a store-and-forward consultation limits the dermatologist's ability to obtain clinically useful information in order to diagnose and manage a patient satisfactorily.

A randomized controlled trial to assess the clinical effectiveness of both realtime and store-and-forward teledermatology compared with conventional care.

The clinical effectiveness of realtime teledermatology, store-and-forward teledermatology and conventional outpatient dermatological care were evaluated in a randomized control trial. A total of 204 patients took part--102 patients were randomized to the realtime teledermatology consultation, 96 of whose cases were also referred using a store-and-forward technique, and 102 to the conventional outpatient consultation. There were no differences in the reported clinical outcomes of realtime teledermatology and conventional dermatology. Of those randomized to the realtime teledermatology consultation, 46% required at least one subsequent hospital appointment compared with 45% of those randomized to the conventional outpatient consultation. In contrast, the dermatologist requested a subsequent hospital appointment for 69% of those seen by store-and-forward teledermatology. An analysis of costs showed that realtime teledermatology was clinically feasible but more expensive than conventional care, while the store-and-forward teledermatology consultation was less expensive but its clinical usefulness was limited. Sensitivity analysis indicated that realtime teledermatology was as economical as conventional care when less artificial assumptions were made about equipment utilization, costs and travel distances to hospital.

Multicentre randomised control trial comparing real time teledermatology with conventional outpatient dermatological care: societal cost-benefit analysis.

OBJECTIVES: Comparison of real time teledermatology with outpatient dermatology in terms of clinical outcomes, cost-benefits, and patient reattendance. DESIGN: Randomised controlled trial with a minimum follow up of three months. SETTING: Four health centres (two urban, two rural) and two regional hospitals. SUBJECTS: 204 general practice patients requiring referral to dermatology services; 102 were randomised to teledermatology consultation and 102 to traditional outpatient consultation. MAIN OUTCOME MEASURES: Reported clinical outcome of initial consultation, primary care and outpatient reattendance data, and cost-benefit analysis of both methods of delivering care. RESULTS: No major differences were found in the reported clinical outcomes of teledermatology and conventional dermatology. Of patients randomised to teledermatology, 55 (54%) were managed within primary care and 47 (46%) required at least one hospital appointment. Of patients randomised to the conventional hospital outpatient consultation, 46 (45%) required at least one further hospital appointment, 15 (15%) required general practice review, and 40 (39%) no follow up visits. Clinical records showed that 42 (41%) patients seen by teledermatology attended subsequent hospital appointments compared with 41 (40%) patients seen conventionally. The net societal cost of the initial consultation was pound132.10 per patient for teledermatology and pound48.73 for conventional consultation. Sensitivity analysis revealed that if each health centre had allocated one morning session a week to teledermatology and the average round trip to hospital had been 78 km instead of 26 km, the costs of the two methods of care would have been equal. CONCLUSIONS: Real time teledermatology was clinically feasible but not cost effective compared with conventional dermatological outpatient care. However, if the equipment were purchased at current prices and the travelling distances greater, teledermatology would be a cost effective alternative to conventional care.

Depression and anxiety as predictors of outcome after myocardial infarction.

OBJECTIVE: The objective of this study was to investigate the significance of emotional distress immediately after a myocardial infarction as a predictor of physical, psychological, and social outcomes and resource use. METHODS: In an epidemiological survey, demographic and cardiological data were obtained for all patients from a defined geographical area who had had a myocardial infarction (according to diagnostic criteria of the Monitoring Trends and Determinants in Cardiovascular Disease [MONICA] trial). Hospital survivors were interviewed and were asked to complete self-report assessments on mental state and quality of life. Full replies were available at baseline for 347 subjects. Self-report follow-up questionnaire information was collected 3 months and 1 year later. RESULTS: Fifteen percent of patients scored as probable cases of anxiety or depression. They were more likely than noncases to report preinfarct distress and poor adjustment (as indicated on the 36-item Medical Outcome Study short form). There was an improvement at 3 months, but there was little overall or individual change after that time. Anxiety and depression did not predict subsequent mortality but did significantly predict poor outcome at 1 year on all dimensions of the 36-item short form quality-of-life measure and on specific measures of everyday activity and reports of chest pain, use of primary care resources, and secondary prevention lifestyle changes. CONCLUSIONS: Subjects who are distressed in the hospital are at high risk of adverse psychological and quality-of-life outcomes during the ensuing year. Our findings strengthen the argument for in-hospital identification and treatment of patients with depression and anxiety after myocardial infarction.

Patient cost-benefit analysis of teledermatology measured in a randomized control trial.

A randomized controlled trial of the costs and benefits of teledermatology consultations compared with traditional hospital consultations was carried out. Over a nine-month period, 197 patients were referred from general practice for a dermatological opinion, 98 for a teledermatology consultation and 99 for a hospital consultation. Eighty patients required an additional subsequent hospital appointment. Patients were asked to complete an economic questionnaire after each consultation, and 164 questionnaires were returned: 62% of those randomized to the teledermatology consultation responded compared with 58% of those randomized to the hospital consultation. Patients seen by teledermatology at their own health centre had shorter distances to travel and spent less time overall attending the appointment compared with those seen at the hospital. However, the teledermatology consultations were more time-consuming for the general practitioner and dermatologist. These findings indicate that teledermatology has more benefits for the patient than for the health-care delivery team.