A series solution and a fast algorithm for the inversion of the spherical mean Radon transform

An explicit series solution is proposed for the inversion of the spherical mean Radon transform. Such an inversion is required in problems of thermo- and photo- acoustic tomography. Closed-form inversion formulae are currently known only for the case when the centers of the integration spheres lie on a sphere surrounding the support of the unknown function, or on certain unbounded surfaces. Our approach results in an explicit series solution for any closed measuring surface surrounding a region for which the eigenfunctions of the Dirichlet Laplacian are explicitly known - such as, for example, cube, finite cylinder, half-sphere etc. In addition, we present a fast reconstruction algorithm applicable in the case when the detectors (the centers of the integration spheres) lie on a surface of a cube. This algorithm reconsrtucts 3-D images thousands times faster than backprojection-type methods

Reference Standards for Body Fat Measure Using GE Dual Energy X-Ray Absorptiometry in Caucasian Adults

Background Dual energy x-ray absorptiometry (DXA) is an established technique for the measurement of body composition. Reference values for these variables, particularly those related to fat mass, are necessary for interpretation and accurate classification of those at risk for obesityrelated health complications and in need of lifestyle modifications (diet, physical activity, etc.). Currently, there are no reference values available for GE-Healthcare DXA systems and it is known that whole-body and regional fat mass measures differ by DXA manufacturer. Objective To develop reference values by age and sex for DXA-derived fat mass measurements with GE-Healthcare systems. Methods A de-identified sample of 3,327 participants (2,076 women, 1,251 men) was obtained from Ball State University\u27s Clinical Exercise Physiology Laboratory and University of Wisconsin- Milwaukee\u27s Physical Activity & Health Research Laboratory. All scans were completed using a GE Lunar Prodigy or iDXA and data reported included percent body fat (%BF), fat mass index (FMI), and ratios of android-to-gynoid (A/G), trunk/limb, and trunk/leg fat measurements. Percentiles were calculated and a factorial ANOVA was used to determine differences in the mean values for each variable between age and sex. Results Normative reference values for fat mass variables from DXA measurements obtained from GE-Healthcare DXA systems are presented as percentiles for both women and men in 10- year age groups. Women had higher (p\u3c0.01) mean %BF and FMI than men, whereas men had higher (p\u3c0.01) mean ratios of A/G, trunk/limb, and trunk/leg fat measurements than women

Sunspot observations from the SOUP instrument on Spacelab 2

A series of white light images obtained by the SOUP instrument on Spacelab 2 of active region 4682 on August 5, 1985 were analyzed in the area containing sunspots. Although the umbra of the spot is underexposed, the film is well exposed in the penumbral regions. These data were digitally processed to remove noise and to separate p-mode oscillations from low velocity material motions. The results of this preliminary investigation include: (1) proper motion measurements of a radial outflow in the photospheric granulation pattern just outside the penumbra; (2) discovery of occasional bright structures (streakers) that appear to be ejected outward from the penumbra; (3) broad dark clouds moving outward in the penumbra in addition to the well known bright penumbral grains moving inward; (4) apparent extensions and contractions of penumbral filaments over the photosphere; and (5) observation of a faint bubble or loop-like structure which seems to expand from two bright penumbral filaments into the photosphere

A study of the social and physical environment in catering kitchens and the role of the chef in promoting positive health and safety behaviour

This is the account of a mixed method study of chefs and their kitchens in order to identify the nature of their workplace and how this affects their ability to manage health and safety in the kitchen. It included extended periods of observation, monitoring of physical parameters, analysis of records of reported accidents, and a series of reflexive interviews. The findings were integrated and then fed back in a smaller number of second interviews in order to test whether the findings fitted in with the chefs' understanding of their world. Major factors identified included survival in a market environment, the status of the chef (and the kitchen) within organisations, marked autocracy of chefs, and an increasing tempo building up to service time with commensurate heat, noise, and activity. In particular during the crescendo, a threshold shift in risk tolerance was identified. The factors, their interplay, and their implications for health and safety in the catering kitchen are discussed

Effect of Self-Efficacy on Weight Loss: A Psychosocial Analysis of a Community-Based Adaptation of the Diabetes Prevention Program Lifestyle Intervention

Objective. Weight loss is the most effective approach to reducing diabetes risk. It is a research priority to identify factors that may enhance weight loss success, particularly among those at risk for diabetes. This analysis explored the relationships between self-efficacy, weight loss, and dietary fat intake among adults at risk for developing type 2 diabetes. Methods. This pilot, site-randomized trial was designed to compare group-based Diabetes Prevention Program lifestyle intervention delivery by YMCA staff to brief counseling alone (control) in 92 adults at risk for diabetes (BMI ≥ 24 kg/m2, ≥ 2 diabetes risk factors, and a random capillary blood glucose of 110–199 mg/dl). Self-efficacy was measured using the Weight Efficacy Lifestyle questionnaire. Data were collected at baseline, 6 months, and 12 months. A paired t test was used to determine within-group changes in self-efficacy and weight at 6 and 12 months. Using a fitted model, we estimated how much of an increase in self-efficacy was related to a 5% weight reduction at 6 and 12 months. Results. Self-efficacy was associated with a 5% reduction in baseline weight at 6 and 12 months but was not related to fat intake. Conclusion. These findings suggest that it is important to assess the level of self-efficacy when counseling adults at high risk for diabetes about weight loss. Certain aspects of self-efficacy seem to play a greater role, depending on the stage of weight loss

Staying in touch : how highly specialised moth pollinators track host plant phenology in unpredictable climates

Background: For specialised pollinators, the synchrony of plant and pollinator life history is critical to the persistence of pollinator populations. This is even more critical in nursery pollination, where pollinators are obligately dependant on female host plant flowers for oviposition sites. Epicephala moths (Gracillariidae) form highly specialised nursery pollination mutualisms with Phyllanthaceae plants. Several hundred Phyllanthaceae are estimated to be exclusively pollinated by highly specific Epicephala moths, making these mutualisms an outstanding example of plant–insect coevolution. However, there have been no studies of how Epicephala moths synchronise their activity with host plant flowering or persist through periods when flowers are absent. Such knowledge is critical to understanding the ecology and evolutionary stability of these mutualisms. We surveyed multiple populations of both Breynia oblongifolia (Phyllanthaceae) and it’s Epicephala pollinators for over two years to determine their phenology and modelled the environmental factors that underpin their interactions. Results: The abundance of flowers and fruits was highly variable and strongly linked to local rainfall and photoperiod. Unlike male flowers and fruits, female flowers were present throughout the entire year, including winter. Fruit abundance was a significant predictor of adult Epicephala activity, suggesting that eggs or early instar larvae diapause within dormant female flowers and emerge as fruits mature. Searches of overwintering female flowers confirmed that many contained pollen and diapausing pollinators. We also observed diapause in Epicephala prior to pupation, finding that 12% (9/78) of larvae emerging from fruits in the autumn entered an extended diapause for 38–48 weeks. The remaining autumn emerging larvae pupated directly without diapause, suggesting a possible bet-hedging strategy. Conclusions: Epicephala appear to use diapause at multiple stages in their lifecycle to survive variable host plant phenology. Furthermore, moth abundance was predicted by the same environmental variables as male flowers, suggesting that moths track flowering through temperature. These adaptations may thereby mitigate against unpredictability in the timing of fruiting and flowering because of variable rainfall. It remains to be seen how widespread egg diapause and pre-pupal diapause may be within Epicephala moths, and, furthermore, to what degree these traits may have facilitated the evolution of these highly diverse mutualisms

The petrology and petrogenesis of the North Motzfeldt Centre, Gardar Province, South Greenland

The Carnegie Trust for the Universities of Scotland, The Percy Sladen Trust, The Royal Geographical Society, The Mineralogical Society of Great Britain and Ireland, NERC and the University of Luton gave financial assistance for the present study. Radiometric studies formed part of a collaborative programme between AAF and TA funded by the British Council.North Motzfeldt is an intrusive igneous centre within the Igaliku (formerly spelt Igaliko) complex, Gardar Province, South Greenland. A detailed field description of the centre is given, with preliminary geochemical and isotopic data. The North Motzfeldt centre is intruded into Ketilidian granitoid basement rocks, and current exposure retains parts of the original roof against earlier Gardar eruptives and elastic sediments of the Eriksfjord formation. The unconformity between the Ketilidian and the overlying Eriksfjord is believed to have been crucial in the siting of the centre. The centre is subdivided into two major units, NM1 and NM2. This was followed by significant peralkaline nepheline microsyenite in sheets, characterized by rare element-rich accessory minerals including rinkite-mosandrite, pyrochlore and lavenite. A significant microsyenite body is called NM3. A preliminary Rb-Sr isochron of 1226 +/- 27 Ma indicates a far younger age for the centre than previously thought (similar to 1350 Ma). Cross-cutting relationships between North Motzfeldt and rocks of the adjacent Motzfeldt centre require a reappraisal of the chronology of Motzfeldt magmatism. We suggest that rocks previously believed to comprise the Motzfeldt centre represent the products of multiple phases of magmatism from Early- to Mid-Gardar times.Publisher PDFPeer reviewe

Rationale, Design, and Baseline Characteristics of a Community-based Comparative Effectiveness Trial to Prevent Type 2 Diabetes in Economically Disadvantaged Adults: The RAPID Study

Reaching Out and Preventing Increases in Diabetes (RAPID) is a community-based randomized trial evaluating the comparative costs and effectiveness of a group-based adaption of the DPP lifestyle intervention developed and implemented in partnership with the YMCA. RAPID enrolled adult primary care patients, with BMI 24 kg/m2 or higher and abnormal glucose metabolism (HbA1c 5.7–6.9% or fasting plasma glucose 100–125 mg/dL). 509 participants were enrolled and randomized to one of two groups: standard clinical advice plus free-of-charge access to a group-based adaption of the DPP offered by the Y, versus standard clinical advice alone. Key outcomes for future analysis will include differences in body weight and other cardiovascular risk factors over a 24-month intervention period. At baseline, RAPID participants had a mean (SD) age of 51 ± 12.1 years, weight of 225.1 ± 56.2 lbs, and BMI of 36.9 ± 8.6 kg/m2. 70.7% were women, 57.2% were African American, 35.4% were non-Hispanic White, and 3.2% were Hispanic. Mean HbA1c was 6.05 ± 0.34%. Additionally, 55.4% of participants had a baseline systolic blood pressure of ≥ 130 mm Hg, 33.1% had a total blood cholesterol exceeding 200 mg/dL, and 74% reported a household income of < $25,000. The RAPID Study successfully randomized a large cohort of participants with a wide distribution of age, body weight, and race who are at high risk for developing type 2 diabetes