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The morphology of englacial drainage networks and their temporal evolution are poorly characterised, particularly within cold ice masses. At present, direct observations of englacial channels are restricted in both spatial and temporal resolution. Through novel use of a terrestrial laser scanning (TLS) system, the interior geometry of an englacial channel in Austre Brøggerbreen, Svalbard, was reconstructed and mapped. Twenty-eight laser scan surveys were conducted in March 2016, capturing the glacier surface around a moulin entrance and the uppermost 122 m reach of the adjoining conduit. The resulting point clouds provide detailed 3-D visualisation of the channel with point accuracy of 6.54 mm, despite low (<60%) overall laser returns as a result of the physical and optical properties of the clean ice, snow, hoar frost and sediment surfaces forming the conduit interior. These point clouds are used to map the conduit morphology, enabling extraction of millimetre-to-centimetre scale geometric measurements. The conduit meanders at a depth of 48 m, with a sinuosity of 2.7, exhibiting teardrop shaped cross-section morphology. This improvement upon traditional surveying techniques demonstrates the potential of TLS as an investigative tool to elucidate the nature of glacier hydrological networks, through reconstruction of channel geometry and wall composition.
Simultaneous use of neutron diffraction and attenuation based transmission Bragg edge imaging for strain measurements is demonstrated in this paper using the pulse neutron source at Los Alamos National Laboratory. Cylindrical samples made from ferritic steel have been subjected to in-situ elastic loading in tension and torsion. Lattice strains were investigated for both deformation modes by time-of-flight (TOF) neutron diffraction using two detector banks at 2θ of ±90°. At the same time, the transmitted portion of the neutron beam was recorded with the goal to analyze the position and shape of the Bragg edges, using a novel time/energy resolved Microchannel Plate (MCP) detector with pixel size of 55 µm and a 28x28 mm2 field of view. Lattice strains obtained using neutron diffraction indicate that the deformation path (tension versus torsion) has important effect on their evolution and related results are summarized.
The emphasis of this paper is to explain the aspects of the experimental setup and data interpretation associated with neutron Bragg edge transmission technique for obtaining through-thickness averaged strain measurements. Implications of using transmission imaging based strain mapping for samples subjected to deformation under tensile loading (where stress at a given cross-section is constant) versus torsional loading (where stress varies linearly from center to outer radius) are discussed. In the case of samples subjected to tensile loading, analysis of the Bragg edge shifts provides the strain value in the direction of the transmitted beam. Thus, three strain components are measured simultaneously when performing Bragg edge imaging in addition to diffraction using two detector banks. For specimens subjected to pure shear by torsion, the Bragg edge transmission technique cannot readily provide quantitative strain information as the mid-point of the Bragg edge does not shift uniformly due to external loading, but results in a broadening of the Bragg edge. Such information can be used to describe the variation of strain distribution along the transmitted beam direction. Spatially resolved Bragg edge maps will be very helpful to detect d-spacing inhomogeneities within the illuminated volume, which may remain undetected when using diffraction only measurements.
Recent studies have suggested that untreated coeliac disease is associated with lower total cholesterol than in the general population while the effect of treatment with a gluten-free diet on the cholesterol profile of clinically apparent coeliac disease is not known. We measured the cholesterol profile at diagnosis, and compared this with Health Survey for England figures, and again following 12 months treatment with a gluten-free diet in 100 consecutive adults with coeliac disease attending the Royal Hallamshire Hospital, Sheffield, UK. The mean total cholesterol was 4·84 (sd 1·2) mmol/l in adults (mean age 51 (sd 16) years) newly diagnosed with coeliac disease. At diagnosis of coeliac disease, men had 21 % lower and women had 9 % lower mean total cholesterol in comparison to the general population (difference in age-adjusted mean total cholesterol − 1·09 mmol/l (95 % CI − 0·97, − 1·21); − 0·46 mmol/l (95 % CI − 0·24, − 0·68), respectively). There was no change in mean total cholesterol following treatment. However, there was a small but statistically significant increase of 0·12 mmol/l (95 % CI 0·05, 0·18) in the mean HDL-cholesterol. Total cholesterol was lower at diagnosis in coeliac patients than in the general population and did not increase with 1 year of a gluten-free diet while HDL-cholesterol increased following treatment. Any increase in risk of IHD or stroke in people with coeliac disease is unlikely due to an adverse cholesterol profile either before diagnosis or after treatment with a gluten-free diet.
Commission 53 on Extrasolar Planets was created at the 2006 Prague General Assembly of the IAU, in recognition of the outburst of astronomical progress in the field of extrasolar planet discovery, characterization, and theoretical work that has occurred since the discovery of the pulsar planets in 1992 and the discovery of the first planet in orbit around a solar-type star in 1995. Commission 53 is the logical successor to the IAU Working Group on Extrasolar Planets WG-ESP, which ended its six years of existence in August 2006. The founding president of Commission 53 is Michael Mayor, in honor of his seminal contributions to this new field of astronomy. The vice-president is Alan Boss, the former chair of the WG-ESP, and the members of the Commission 53 Organizing Committee are the other former members of the WG-ESP.
Despite being widely recognized as a significant public health problem there are surprisingly few contemporary data available on the incidence of pneumonia in the UK. We conducted a general population-based cohort study to determine the incidence of pneumonia in general practice in the United Kingdom. Data were obtained from The Health Improvement Network (THIN) – a computerized, longitudinal, general practice database. Recorded diagnoses of pneumonia between 1991 and 2003 were used to calculate the incidence of pneumonia stratified by year, sex, age group and deprivation score. The overall incidence of pneumonia was 233/100 000 person-years [95% confidence interval (CI) 231–235] and this rate was stable between 1991 and 2003. The incidence of pneumonia was slightly lower in females compared to males [age-adjusted incidence rate ratio (IRR) 0·88, 95% CI 0·86–0·89]. Pneumonia was most common in children aged <4 years and adults aged >65 years. There was an increased incidence of pneumonia with higher levels of socioeconomic disadvantage such that people living in the most deprived areas of the United Kingdom were 28% more likely to get pneumonia than those in the least deprived areas (age- and gender-adjusted IRR 1·28, 95% CI 1·24–1·32). In conclusion, pneumonia is an important public health problem and the incidence of pneumonia is higher in people at the extremes of age, men and people living in socially deprived areas.