268 research outputs found

    Geologic Mapping of Athabasca Valles

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    We are approaching the end of the third year of mapping the Athabasca Valles region of Mars. The linework has been adjusted in response to new CTX images and we are on schedule to submit the 4 MTM quads (05202, 05207, 10202, 10207) and ac-companying paper by the end of this fiscal year

    Geologic Mapping of Athabasca Valles

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    Two factors drive us to map the Athabasca Valles area in unusual detail: (1) the extremely well-preserved and exposed surface morphologies and (2) the extensive high resolution imaging. In particular, the near-complete CTX coverage of Athabasca Valles proper and the extensive coverage of its surroundings have been invaluable. The mapping has been done exclusively in ArcGIS, using individual CTX, THEMIS VIS, and MOC frames overlying the THEMIS IR daytime basemap. MOLA shot points and gridded DTMs are also included. It was found that CTX images processed through ISIS are almost always within 300 m of the MOLA derived locations, and usually within tens of meters, with no adjustments to camera pointing. THEMIS VIS images appear to be systematically shifted to the southwest of their correct positions and MOC images are often kilometers off. The good SNR and minimal artifacts make the CTX images vastly more useful than the THEMIS VIS or MOC images. The bulk of the mapping was done at 1:50,000 scale on CTX images. In more complex areas, mapping at 1:24,000 proved necessary. The CTX images were usually simultaneously viewed on a second monitor using the ISIS3 qview program to display the full dynamic range of the CTX data. Where CTX data was not available, mapping was often done at 1:100,000 and most contacts are mapped as approximate

    NEUTRINOS FROM PRIMORDIAL BLACK HOLES

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    The emission of particles from black holes created in the early Universe has detectable astrophysical consequences. The most stringent bound on their abundance has been obtained from the absence of a detectable diffuse flux of 100 MeV photons. Further scrutiny of these bounds is of interest as they, for instance, rule out primordial black holes as a dark matter candidate. We here point out that these bounds can, in principle, be improved by studying the diffuse cosmic neutrino flux. Measurements of near-vertical atmospheric neutrino fluxes in a region of low geomagnetic latitude can provide a competitive bound. The most favorable energy to detect a possible diffuse flux of primordial black hole origin is found to be a few MeV. We also show that measurements of the diffuse ντ\nu _\tau flux is the most promising to improve the existing bounds deduced from gamma-ray measurements. Neutrinos from individual black hole explosions can be detected in the GeV-TeV energy region. We find that the kilometer-scale detectors, recently proposed, are able to establish competitive bounds.Comment: 19 pages plus 9 uuencoded and compressed postscript figure

    Two randomized crossover multicenter studies investigating gastrointestinal symptoms after bread consumption in individuals with noncoeliac wheat sensitivity: do wheat species and fermentation type matter?

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    Background: Many individuals reduce their bread intake due to the belief that wheat is the cause of their gastrointestinal (GI) symptoms. Different grains and processing methods may impact tolerability. Objective: We investigated the effects of six different types of bread on GI symptoms in individuals with self-reported non-coeliac wheat sensitivity (NCWS). Methods: Two parallel randomised double-blind crossover multicentre studies were conducted. NCWS individuals, in whom coeliac disease and wheat allergy were ruled out, received five slices of (study A, n=20) yeast fermented (YF) or (study B, n=20) sourdough fermented (SF) bread made of bread wheat, spelt or emmer on three separate intervention days. Each test day was preceded by a run-in period of 3 days and separated by a wash-out period of at least 7 days. GI symptoms were evaluated by change in symptom score (test day minus average of the 3-day run-in period) on a 0-100mm visual analogue scale (delta VAS). Responders were defined as an increase in delta VAS of at least 15mm for overall GI symptoms, abdominal discomfort, abdominal pain, bloating and/or flatulence. Results: The overall change in GI symptoms did not differ between breads of different grains (YF p=0.267; SF p=0.144). The number of responders was also comparable for both YF (6 to wheat, 5 to spelt, and 7 to emmer, p=0.761) and SF breads (9 to wheat, 7 to spelt, and 8 to emmer, p=0.761). Conclusion: The majority of NCWS individuals experienced GI symptoms for at least one of the breads, but on a group level, no differences were found between different grain types for either YF or SF breads. Clinical Trial Registry: ClinicalTrials.gov, NCT0408447

    Taking the pulse of Mars via dating of a plume-fed volcano

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    Open Access This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The images or other third party material in this article are included in the article’s Creative Commons license, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons license and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this license, visit http://creativecommons.org/licenses/by/4.0/. The attached file is the published version of the article

    Psychometric evaluation of an experience sampling method–based patient-reported outcome measure in functional dyspepsia

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    Background: Due to important biases, conventional end-of-day and end-of-week assessment methods of gastrointestinal symptoms in functional dyspepsia (FD) are considered suboptimal. Real-time symptom assessment based on the experience sampling method (ESM) could be a more accurate measurement method. This study aimed to evaluate validity and reliability of an ESM-based patient-reported outcome measure (PROM) for symptom assessment in FD. Methods: Thirty-five patients with FD (25 female, mean age 44.7 years) completed the ESM-based PROM (a maximum of 10 random moments per day) and an end-of-day symptom diary for 7 consecutive days. On day 7, end-of-week questionnaires were completed including the Nepean Dyspepsia Index (NDI) and Patient Assessment of Gastrointestinal Symptom Severity Index (PAGI-SYM). Key Results: Experience sampling method and corresponding end-of-day scores for gastrointestinal symptoms were significantly associated (ICCs range 0.770–0.917). However, end-of-day scores were significantly higher (Δ0.329–1.031) than mean ESM scores (p < 0.05). Comparing ESM with NDI and PAGI-SYM scores, correlations were weaker (Pearson's r range 0.467–0.846). Cronbach's α coefficient was good for upper gastrointestinal symptoms (α = 0.842). First half-week and second half-week scores showed very good consistency (ICCs range 0.913–0.975). Conclusion and Inferences: Good validity and reliability of a novel ESM-based PROM for assessing gastrointestinal symptoms in FD patients was demonstrated. Moreover, this novel PROM allows to evaluate individual symptom patterns and can evaluate interactions between symptoms and environmental/contextual factors. ESM has the potential to increase patients' disease insight, provide tools for self-management, and improve shared decision making. Hence, this novel tool may aid in the transition toward personalized health care for FD patients
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