Fusion energy-production from a deuterium-tritium plasma in the jet tokamak

Describes a series of experiments in the Joint European Torus (JET), culminating in the first tokamak discharges in deuterium-tritium fuelled mixture. The experiments were undertaken within limits imposed by restrictions on vessel activation and tritium usage. The objectives were: (i) to produce more than one megawatt of fusion power in a controlled way; (ii) to validate transport codes and provide a basis for accurately predicting the performance of deuterium-tritium plasmas from measurements made in deuterium plasmas; (iii) to determine tritium retention in the torus systems and to establish the effectiveness of discharge cleaning techniques for tritium removal; (iv) to demonstrate the technology related to tritium usage; and (v) to establish safe procedures for handling tritium in compliance with the regulatory requirements. A single-null X-point magnetic configuration, diverted onto the upper carbon target, with reversed toroidal magnetic field was chosen. Deuterium plasmas were heated by high power, long duration deuterium neutral beams from fourteen sources and fuelled also by up to two neutral beam sources injecting tritium. The results from three of these high performance hot ion H-mode discharges are described: a high performance pure deuterium discharge; a deuterium-tritium discharge with a 1% mixture of tritium fed to one neutral beam source; and a deuterium-tritium discharge with 100% tritium fed to two neutral beam sources. The TRANSP code was used to check the internal consistency of the measured data and to determine the origin of the measured neutron fluxes. In the best deuterium-tritium discharge, the tritium concentration was about 11% at the time of peak performance, when the total neutron emission rate was 6.0&nbsp;&times;&nbsp;1017&nbsp;neutrons/s. The integrated total neutron yield over the high power phase, which lasted about 2 s, was 7.2&nbsp;&times;&nbsp;1017&nbsp;neutrons, with an accuracy of &plusmn;7%. The actual fusion amplification factor, QDT&nbsp;was about 0.15</span

Evaluation of a type 2 diabetes prevention program using a commercial weight management provider for non-diabetic hyperglycemic patients referred by primary care in the UK

Objectives: To determine if a diabetes prevention program (DPP) delivered by a commercial weight management provider using a UK primary care referral pathway could reduce the progression to type 2 diabetes (T2D) in those diagnosed with non-diabetic hyperglycemia (NDH—being at high risk of developing T2D). Research design: This is a quasi-experimental translational research study. Methods: 14 primary care practices identified, recruited and referred patients with NDH (fasting plasma glucose ≥5.5 to ≤6.9mmol/L and/or glycated hemoglobin (HbA1c) ≥42 to 47mmol/mol (6.0%–6.4%)) and a body mass index (BMI) ≥30 kg/m2 to a DPP. Eligible patients were asked to contact Weight Watchers to book onto their DPP, an intensive lifestyle intervention which included a 90min activation session followed by the offer of 48 weekly Weight Watchers community group meetings. Patients’ blood tests were repeated by primary care, weight change plus self-reported data was recorded by Weight Watchers. Results: 166 patients were referred to the program and 149 were eligible. 79% of eligible patients attended an activation session (117 eligible patients) and 77% started the weekly sessions. The study sample was primarily female (75%), white (90%), with 5% living in the most deprived quintile in the UK. Using intention to-treat analysis, the DPP resulted in a mean reduction in HbA1c of 2.84 mmol/mol at 12 months (from 43.42±1.28 to 40.58±3.41, p<0.01). 38% of patients returned to normoglycemia and 3% developed T2D at 12 months. There was a mean weight reduction in BMI of 3.2 kg/m2 at 12 months (35.5 kg/m2 ±5.4 to 32.3 kg/ m2 ±5.2, p<0.01). Conclusion: A UK primary care referral route partnered with this commercial weight management provider can deliver an effective DPP. The lifestyle changes and weight loss achieved in the intervention translated into considerable reductions in diabetes risk, with an immediate and significant public health impact

The "0.4 eV" Shape Resonance of Electron Scattering from Mercury in a Franck-Hertz Tube

The alternative version of the Franck-Hertz experiment with mercury, in which a two-grid tube is used as a combination of electron gun, equipotential collision space, and detection cell, was analyzed recently in considerable detail. In particular, it was inferred that, at optimal pressure, the formation of peaks in the anode current at inelastic thresholds is mediated inside the detection cell by the large variation, a maximum at 0.4 eV, in the cross section for elastic scattering. This variation is due to a shape resonance in the electron-mercury system and is observable persuasively at the onset of anode current as a sharp peak followed by a clear minimum. In the present paper, the passage of electrons through the second grid to anode region is analyzed in terms of kinetic theory. The discussion is based on a simplified expression for the electron current derivable from an approximate form of the Boltzmann transport equation that maintains the spatial density gradient but omits elastic energy losses. The estimated range of pressure underlying this kind of idealization is in good agreement with experiment. An explicit solution is obtained by constructing an analytic expression for the momentum transfer cross section of mercury using a recent theory of generalized Fano profiles for overlapping resonances. This solution is used in order to model successfully the formation of peaks at the threshold of anode current and at excitation potentials, and to explain the dependence of the observed profiles on the pressure and on the sign and magnitude of the potential across the detection cell

Methacholine bronchial provocation measured by spirometry versus wheeze detection in preschool children

BACKGROUND: Determination of PC(20)-FEV(1) during Methacholine bronchial provocation test (MCT) is considered to be impossible in preschool children, as it requires repetitive spirometry sets. The aim of this study was to assess the feasibility of determining PC(20)-FEV(1) in preschool age children and compares the results to the wheeze detection (PCW) method. METHODS: 55 preschool children (ages 2.8–6.4 years) with recurrent respiratory symptoms were recruited. Baseline spirometry and MCT were performed according to ATS/ERS guidelines and the following parameters were determined at baseline and after each inhalation: spirometry-indices, lung auscultation at tidal breathing, oxygen saturation, respiratory and heart rate. Comparison between PCW and PC(20)-FEV(1) and clinical parameters at these end-points was done by paired Student's t-tests. RESULTS AND DISCUSSION: Thirty-six of 55 children (65.4%) successfully performed spirometry-sets up to the point of PCW. PC(20)-FEV(1) occurred at a mean concentration of 1.70+/-2.01 while PCW occurred at a mean concentration of 4.37+/-3.40 mg/ml (p < 0.05). At PCW, all spirometry-parameters were markedly reduced: FVC by 41.3+/-16.4% (mean +/-SD); FEV(1) by 44.7+/-14.5%; PEFR by 40.5+/-14.5 and FEF(25–75) by 54.7+/-14.4% (P < 0.01 for all parameters). This reduction was accompanied by de-saturation, hyperpnoea, tachycardia and a response to bronchodilators. CONCLUSION: Determination of PC(20)-FEV(1) by spirometry is feasible in many preschool children. PC(20)-FEV(1) often appears at lower provocation dose than PCW. The lower dose may shorten the test and encourage participation. Significant decrease in spirometry indices at PCW suggests that PC(20)-FEV(1) determination may be safer

Parenting and oral health in an inner-city environment: a qualitative pilot study

Background Preventable oral diseases such as dental caries remain common in the United Kingdom. Clustering of poor health is observed within deprived communities, such as inner-city areas, where elevated levels of dental need are associated with lower uptake of dental care. Successful oral health promotion (OHP) initiatives are contingent upon effective community engagement. The aim of this pilot study was to engage with families with young children to explore community views on oral health and dental care and thus tailor OHP initiatives more effectively to their needs. Methods Qualitative research, involving individual interviews and triad focus groups with parents/caregivers, was conducted in a south London inner-city community as part of a ‘Well London’ programme initiative. Results Seventeen parents/caregivers participated in this pilot study. Parents/caregivers described a spectrum of oral health behaviours based on their social history, past dental experiences and cultural influences. All parents described a clear desire to create healthy lives for their children; however, two broad groups were apparent, termed ‘Oral Health Prioritisers’ and ‘Oral Health Non-prioritisers’. The former reported regularly accessing dental care for their children, believing that oral health contributes to systemic health. Non-prioritisers, however, preferentially used key services considered most beneficial to their child’s wellbeing. Dental services were considered a low priority for this group, where oral health was synonymous with absence of pain. Participants in both groups favoured OHP initiatives involving a range of health and social care services, with schools at the epicentre of programmes. First-time parents were proposed as an important group requiring support in future OHP initiatives with evidence suggesting that first-born children may have delayed presentation to a dentist. Conclusions The findings suggest that this inner-city community may contain sub-groups with contrasting perspectives on oral health and oral health behaviours; nevertheless, there was support for a systems approach to oral health promotion initiatives involving a range of health and social care services, including a critcal role for schools, and actively connecting with first-time parents. The findings provide the basis for further research

Plague Circulation and Population Genetics of the Reservoir Rattus rattus: The Influence of Topographic Relief on the Distribution of the Disease within the Madagascan Focus.

International audienceBACKGROUND: Landscape may affect the distribution of infectious diseases by influencing the population density and dispersal of hosts and vectors. Plague (Yersinia pestis infection) is a highly virulent, re-emerging disease, the ecology of which has been scarcely studied in Africa. Human seroprevalence data for the major plague focus of Madagascar suggest that plague spreads heterogeneously across the landscape as a function of the relief. Plague is primarily a disease of rodents. We therefore investigated the relationship between disease distribution and the population genetic structure of the black rat, Rattus rattus, the main reservoir of plague in Madagascar. METHODOLOGYPRINCIPAL FINDINGS: We conducted a comparative study of plague seroprevalence and genetic structure (15 microsatellite markers) in rat populations from four geographic areas differing in topology, each covering about 150-200 km(2) within the Madagascan plague focus. The seroprevalence levels in the rat populations mimicked those previously reported for humans. As expected, rat populations clearly displayed a more marked genetic structure with increasing relief. However, the relationship between seroprevalence data and genetic structure differs between areas, suggesting that plague distribution is not related everywhere to the effective dispersal of rats. CONCLUSIONSSIGNIFICANCE: Genetic diversity estimates suggested that plague epizootics had only a weak impact on rat population sizes. In the highlands of Madagascar, plague dissemination cannot be accounted for solely by the effective dispersal of the reservoir. Human social activities may also be involved in spreading the disease in rat and human populations

Neuromuscular abnormality and autonomic dysfunction in patients with cerebrotendinous xanthomatosis

<p>Abstract</p> <p>Background</p> <p>Cerebrotendinous xanthomatosis (CTX) is a rare lipid-storage disease. Neuromuscular abnormality and autonomic system (ANS) dysfuction in CTX are rarely examined in large-scale studies in the literature. We studied the peripheral nervous system, myopathology, and autonomic system of four CTX patients and performed a literature review of the reported CTX patients with peripheral neuropathy.</p> <p>Methods</p> <p>Four biochemically and genetically confirmed CTX patients, belonging to two families, were included for study and all received nerve conduction study (NCS), muscle biopsy for histopathologic and ultrastructural study, skin biopsy for intraepidermal nerve fiber (INEF) density measurement, autonomic testings including sympathetic skin response, R-R interval variation and head-up tilt test using an automated tilt table to record the changes of blood pressure and heart rate in different postures. The Q-Sweat test was also applied for the detection of sweat amount and onset time of response. The clinical characteristics, study methods and results of 13 studies of peripheral neuropathy in CTX patients in the literature were also recorded for analysis.</p> <p>Results</p> <p>The results of NCS study showed axonal sensory-motor polyneuropathy in three CTX cases and mixed axonal and demyelinating sensor-motor polyneuropathy in one. The myopathological and histopathologic studies revealed mild denervation characteristics, but the ultrastructural study revealed changes of mitochondria and the membranous system, and increased amounts of glycogen, lipofuscin and lipid deposition. The ANS study revealed different degrees of abnormalities in the applied tests and the INEF density measurement showed small fiber neuropathy in three of the four CTX patients. The literature review of peripheral neuropathy in CTX revealed different types of peripheral neuropathy, of which axonal peripheral neuropathy was the most common.</p> <p>Conclusions</p> <p>Peripheral neuropathy, especially the subtype of axonal sensori-motor neuropathy, is common in patients with CTX. Evidence of lipid metabolic derangement in CTX can be reflected in ultrastructural studies of muscles. With an adequate multi-parametric evaluation, a high incidence of ANS abnormalities can be seen in this rare lipid-storage disease, and a high incidence of small fiber involvement is also reflected in the IENF density measurement of skin biopsies.</p

Ubiquitous healthy diatoms in the deep sea confirm deep carbon injection by the biological pump

The role of the ocean as a sink for CO2 is partially dependent on the downward transport of phytoplankton cells packaged within fast-sinking particles. However, whether such fast-sinking mechanisms deliver fresh organic carbon down to the deep bathypelagic sea and whether this mechanism is prevalent across the ocean requires confirmation. Here we report the ubiquitous presence of healthy photosynthetic cells, dominated by diatoms, down to 4,000 m in the deep dark ocean. Decay experiments with surface phytoplankton suggested that the large proportion (18%) of healthy photosynthetic cells observed, on average, in the dark ocean, requires transport times from a few days to a few weeks, corresponding to sinking rates (124–732 m d−1) comparable to those of fast-sinking aggregates and faecal pellets. These results confirm the expectation that fast-sinking mechanisms inject fresh organic carbon into the deep sea and that this is a prevalent process operating across the global oligotrophic ocean