X-ray mapping and scatter diagram analysis of the discoloring products resulting from the interaction of artist's pigments

The discoloring interaction between the artist's pigments cadmium yellow and the copper-containing malachite, an interaction that is conjectured to cause black spotting in oil paintings of the 19th and early 20th centuries, was examined using X-ray mapping and scatter diagram analysis. The application of these coupled techniques confirmed that copper sulfide phases were produced during discoloration reaction. Scatter diagram analysis indicated that two copper sulfide stoichiometries (CuS and Cu3S2) were present as reaction products where previously only crystalline CuS (covellite) had been identified by X-ray diffraction. The results demonstrate the potential of X-ray mapping coupled with scatter diagram analysis for the identification of both crystalline and X-ray amorphous phases produced by such complex heterogeneous interactions and their applicability to the investigation of interactions of artists' pigments. © Microscopy Society of America 2010

The pattern of underlying cause of death in patients with inflammatory bowel disease in England: a record linkage study

Background and Aims: Numerous studies have established that mortality risk in IBD patients is higher than the general population, but the causes of death have seldom been examined. We aimed to describe causes of death in IBD. Methods: A matched cohort study using UK general practice data from Clinical Practice Research Datalink linked to death registration records. We described the distribution of causes of death among IBD patients by age at death and time since IBD diagnosis. We estimated age-specific mortality rates and hazard ratios of death in multivariable Cox proportional hazards models. Results: 20,293 IBD patients were matched to 83,261 non-IBD patients. The mortality rate was 40% higher in IBD patients (2005 deaths) than in non-IBD patients (6024 deaths) (adjusted overall hazard ratio = 1.4, 95% CI = 1.4—1.5), with greater risk of death in Crohn’s disease (hazard ratio = 1.6, 1.5—1.7) than in ulcerative colitis (1.3, 1.3—1.4). Causes attributable to IBD constituted 3.7% of all deaths in ulcerative colitis and 8.3% in Crohn’s disease. Among IBD patients, death was less likely to be due to circulatory, respiratory or neoplastic diseases than non-IBD patients. In both IBD and non-IBD patients all these causes became more clinically important with advancing age, with the commonest neoplastic cause of death being lung cancer, rather than gastrointestinal cancers. Conclusion: IBD patients have an additional risk of death. Most IBD patients die of circulatory or respiratory causes, and the contribution to mortality from long-term complications of IBD are clinically less important

Design and Early In-flight Performance of the Tropical Rainfall Measuring Mission (TRMM) Power Subsystem

Maryland built the spacecraft in-house with four U.S. instruments and one Japanese instrument, the first space flown Precipitation Radar (PR). The TRMM Observatory was successfully launched from Tanegashima Space Center in Japan on an H-2 Expendable Launch Vehicle on November 27, 1997. This paper presents an overview of the TRMM Power System including its design, testing, and in flight performance for the first 70 days. Finally, key lessons learned are presented. The TRMM power system consists of an 18.1 square meter deployed solar array fabricated by TRW with Tecstar GaAs/Ge cells, two (2) Hughes 50 Ampere-Hour (Ah) Super NiCd' batteries, each with 22 Eagle-Picher cells, and three (3) electronics boxes designed to provide power regulation, battery charge control, and command and telemetry interface

Resolving the inner jet structure of 1924-292 with the EVENT HORIZON TELESCOPE

We present the first 1.3 mm (230 GHz) very long baseline interferometry model image of an AGN jet using closure phase techniques with a four-element array. The model image of the quasar 1924-292 was obtained with four telescopes at three observatories: the James Clerk Maxwell Telescope (JCMT) on Mauna Kea in Hawaii, the Arizona Radio Observatory's Submillimeter Telescope (SMT) in Arizona, and two telescopes of the Combined Array for Research in Millimeterwave Astronomy (CARMA) in California in April 2009. With the greatly improved resolution compared with previous observations and robust closure phase measurement, the inner jet structure of 1924-292 was spatially resolved. The inner jet extends to the northwest along a position angle of $-53^\circ$ at a distance of 0.38\,mas from the tentatively identified core, in agreement with the inner jet structure inferred from lower frequencies, and making a position angle difference of $\sim 80^{\circ}$ with respect to the cm-jet. The size of the compact core is 0.15\,pc with a brightness temperature of $1.2\times10^{11}$\,K. Compared with those measured at lower frequencies, the low brightness temperature may argue in favor of the decelerating jet model or particle-cascade models. The successful measurement of closure phase paves the way for imaging and time resolving Sgr A* and nearby AGN with the Event Horizon Telescope.Comment: 6 pages, 4 figures, accepted for publication in ApJ

1.3 mm Wavelength VLBI of Sagittarius A*: Detection of Time-Variable Emission on Event Horizon Scales

Sagittarius A*, the ~4 x 10^6 solar mass black hole candidate at the Galactic Center, can be studied on Schwarzschild radius scales with (sub)millimeter wavelength Very Long Baseline Interferometry (VLBI). We report on 1.3 mm wavelength observations of Sgr A* using a VLBI array consisting of the JCMT on Mauna Kea, the ARO/SMT on Mt. Graham in Arizona, and two telescopes of the CARMA array at Cedar Flat in California. Both Sgr A* and the quasar calibrator 1924-292 were observed over three consecutive nights, and both sources were clearly detected on all baselines. For the first time, we are able to extract 1.3 mm VLBI interferometer phase information on Sgr A* through measurement of closure phase on the triangle of baselines. On the third night of observing, the correlated flux density of Sgr A* on all VLBI baselines increased relative to the first two nights, providing strong evidence for time-variable change on scales of a few Schwarzschild radii. These results suggest that future VLBI observations with greater sensitivity and additional baselines will play a valuable role in determining the structure of emission near the event horizon of Sgr A*.Comment: 8 pages, submitted to ApJ

The profiling of diet and physical activity in reproductive age women and their association with body mass index

Pre-pregnancy, pregnancy and postpartum are critical life stages associated with higher weight gain and obesity risk. Among these women, the sociodemographic groups at highest risk for suboptimal lifestyle behaviours and core lifestyle components associated with excess adiposity are unclear. This study sought to identify subgroups of women meeting diet/physical activity (PA) recommendations in relation to sociodemographics and assess diet/PA components associated with body mass index (BMI) across these life stages. Cross-sectional data (Australian National Nutrition and Physical Activity Survey 2011-2012) were analysed for pre-pregnancy, pregnant and postpartum women. The majority (63-95%) of women did not meet dietary or PA recommendations at all life stages. Core and discretionary food intake differed by sociodemographic factors. In pre-pregnant women, BMI was inversely associated with higher whole grain intake (β = -1.58, 95% CI -2.96, -0.21; = 0.025) and energy from alcohol (β = -0.08, -0.14, -0.005; = 0.035). In postpartum women, BMI was inversely associated with increased fibre (β = -0.06, 95% CI -0.11, -0.004; = 0.034) and PA (β = -0.002, 95% CI -0.004, -0.001; = 0.013). This highlights the need for targeting whole grains, fibre and PA to prevent obesity across life stages, addressing those most socioeconomically disadvantaged

Vibrational Spectra of a Mechanosensitive Channel

We report the simulated vibrational spectra of a mechanosensitive membrane channel in different gating states. Our results show that while linear absorption is insensitive to structural differences, linear dichroism and sum-frequency generation spectroscopies are sensitive to the orientation of the transmembrane helices, which is changing during the opening process. Linear dichroism cannot distinguish an intermediate structure from the closed structure, but sum-frequency generation can. In addition, we find that two-dimensional infrared spectroscopy can be used to distinguish all three investigated gating states of the mechanosensitive membrane channel.