Mineralogical comparison of Northwest Africa 6112 and Divnoe ungrouped achondrites

第6回極域科学シンポジウム[OA] 南極隕石11月16日（月）　国立国語研究所 2階 講

Petrological, petrofabric, and oxygen isotopic study of five ungrouped meteorites related to brachinites

Northwest Africa (NWA) 6112, Miller Range (MIL) 090206 (plus its pairs: MIL 090340 and MIL 090405), and Divnoe are olivine-rich ungrouped achondrites. We investigated and compared their petrography, mineralogy, and olivine fabrics. We additionally measured the oxygen isotopic compositions of NWA 6112. They show similar petrography, mineralogy, and oxygen isotopic compositions and we concluded that these five meteorites are brachinite clan meteorites. We found that NWA 6112 and Divnoe had a c axis concentration pattern of olivine fabrics using electron backscattered diffraction (EBSD). NWA 6112 and Divnoe are suggested to have been exposed to magmatic meltflows during their crystallization on their parent body. On the other hand, the three MIL meteorites have b axis concentration patterns of olivine fabrics. This indicates that the three MIL meteorites may be cumulates where compaction of olivine grains was dominant. Alternatively, they formed as residues and were exposed to olivine compaction. The presence of two different olivine fabric patterns implies that the parent body(s) of brachinite clan meteorites experienced diverse igneous processes

Current status of clinical background of patients with atrial fibrillation in a community-based survey: The Fushimi AF Registry

AbstractBackgroundAtrial fibrillation (AF) increases the risks of stroke and death, and the prevalence of AF is increasing significantly. Until recently, warfarin was the only oral anticoagulant for stroke prevention, but novel anticoagulants are now under development.Methods and resultsThe Fushimi AF Registry is a community-based survey of AF patients. We aimed to enroll all of the AF patients in Fushimi-ku, which is located at the southern end of the city of Kyoto. Fushimi-ku is densely populated with a total population of 283,000, and is assumed to represent a typical urban community in Japan. On the basis of the general prevalence of AF in the Japanese (0.6%), we estimated the total number of AF patients as 1700. A total of 76 institutions, a large proportion of which were private clinics, participated in the study. At present, we have enrolled 3183 patients from March 2011 to June 2012 (approximately 1.12% of total population). The mean age was 74.2±11.0 years, and 59.3% of subjects were male. The mean body weight was 58.5±13.2kg, and the proportions with a body weight of less than 50kg and 60kg were 25.7% and 55.0%, respectively. The type of AF was paroxysmal in 46.0%, persistent in 7.3%, and permanent in 46.7%. Major co-existing diseases were hypertension (60.6%), heart failure (27.9%), diabetes (23.2%), stroke (19.4%), coronary artery disease (15.0%), myocardial infarction (6.4%), dyslipidemia (42.4%), and chronic kidney disease (26.4%). The mean CHADS2 score was 2.09±1.35: 0 in 11.8% of patients, 1 in 27.1%, and 2 in 29.1%. Warfarin was prescribed in only 48.5% of patients, whereas anti-platelet drugs, mainly aspirin, were prescribed for more than 30% of the patients.ConclusionsThe Fushimi AF Registry provides a unique snapshot of current AF management in an urban community in Japan

Establishment and evaluation of the suspension culture system for umbilical cord- derived mesenchymal stromal cells

Mesenchymal stromal cells (MSCs) derived from various tissues including bone marrow, adipose and umbilical cord tissues have been shown to modulate aberrantly activated immune system. With the features, MSC-based therapies targeting graft-versus-host disease (GvHD) by the administration of bone marrow-derived MSCs (BM-MSCs) have been available in some countries including Japan, and the expectations for the stable and cost effective supply system are getting higher and higher recently. However, the conventional culture systems which usually use plastic flask or multi-chamber equipment require space and manpower, thus the maximal expansion of MSCs at one production is likely to be limited. To compensate the limitation, repetitive productions have been unavoidable, and higher the production cost. Here, we introduced a new suspension-culture system, using micro-carriers and single-use-bioreactors, for the preparation of MSCs in anticipation of establishment of mass production system. Since the umbilical cord (UC) tissues can be collected through noninvasive procedure, and UC-derived MSCs (UC-MSCs) are shown to present higher proliferation rate and lower immunogenicity in comparison with BM-MSCs, we evaluated the potential and the versatility of UC-MSCs for the treatment of several diseases including GvHD. Results from several in vitro assays demonstrated that our new culture system maintains major key characteristics of MSCs, such as adhesiveness to cell culture surface, the expression of cell surface markers, differentiation capacities toward osteoblasts, chondroblasts, and adipocytes, and immunosuppressive effects on activated T cells. We are currently investigating cellular profiles and characteristics which are specific to the cells prepared in our suspension-culture system through meta-analysis. The established suspension-culture system is presumed to attain the mass production of UC-MSCs, contributing to lower the cost and also providing possible applications for MSCs from other origins

Measuring the Shock Stage of Asteroid Regolith Grains by Electron Back-Scattered Diffraction

We have been analyzing Itokawa samples in order to definitively establish the degree of shock experienced by the regolith of asteroid Itokawa, and to devise a bridge between shock determinations by standard light optical petrography, crystal structures as determined by electron and X-ray diffraction. These techniques would then be available for samples returned from other asteroid regoliths

Measuring Shock Stage of ltokawa Regolith Grains by Electron Back-Scattered Diffraction and Synchrotron X-Ray Diffraction

We have been analyzing Itokawa samples in order to definitively establish the degree of shock experienced by the regolith of asteroid Itokawa, and to devise a bridge between shock determinations by standard light optical petrography, crystal structures as determined by electron and X-ray diffraction techniques. We are making measurements of olivine crystal structures and using these to elucidate critical regolith impact processes. We use electron back-scattered diffraction (EBSD) and synchrotron X-ray diffraction (SXRD). We are comparing the Itokawa samples to L and LL chondrite meteorites chosen to span the shock scale experienced by Itokawa, specifically Chainpur (LL3.4, Shock Stage 1), Semarkona (LL3.00, S2), Kilabo (LL6, S3), NWA100 (L6, S4) and Chelyabinsk (LL5, S4). In SXRD we measure the line broadening of olivine reflections as a measure of shock stage. In this presentation we concentrate on the EBSD work. We employed JSC's Supra 55 variable pressure FEG-SEM and Bruker EBSD system. We are not seeking actual strain values, but rather indirect strain-related measurements such as extent of intra-grain lattice rotation, and determining whether shock state "standards" (meteorite samples of accepted shock state, and appropriate small grain size) show strain measurements that may be statistically differentiated, using a sampling of particles (number and size range) typical of asteroid regoliths. Using our system we determined that a column pressure of 9 Pa and no C-coating on the sample was optimal. We varied camera exposure time and gain to optimize mapping performance, concluding that 320x240 pattern pixilation, frame averaging of 3, 15 kV, and low extractor voltage yielded an acceptable balance of hit rate (>90%), speed (11 fps) and map quality using an exposure time of 30 ms (gain 650). We found that there was no strong effect of step size on Grain Orientation Spread (GOS) and Grain Reference Orientation Deviation angle (GROD-a) distribution; there was some effect on grain average Kernel Average Misorientation (KAM) (reduced with smaller step size for the same grain), as expected. We monitored GOS, Maximum Orientation Spread (MOS) and GROD-a differences between whole olivine grains and sub-sampled areas, and found that there were significant differences between the whole grain dataset and subsets, as well as between subsets, likely due to sampling-related "noise". Also, in general (and logically) whole grains exhibit greater degrees of cumulative lattice rotation. Sampling size affects the apparent strain character of the grain, at least as measured by GOS, MOS and GROD-a. There were differences in the distribution frequencies of GOS and MOS between shock stages, and in plots of MOS and GOS vs. grain diameter. These results are generally consistent with those reported this year. However, it is unknown whether the differences between samples of different shock states exceeds the clustering of these values to the extent that shock stage determinations can still be made with confidence. We are investigating this by examination of meteorites with higher shock stage 4 to 5. Our research will improve our understanding of how small, primitive solar system bodies formed and evolved, and improve understanding of the processes that determine the history and future of habitability of environments on other solar system bodies. The results will directly enrich the ongoing asteroid and comet exploration missions by NASA and JAXA, and broaden our understanding of the origin and evolution of small bodies in the early solar system, and elucidate the nature of asteroid and comet regolith