Meteoritics最新文献

{"title":"Marginal Zone Lymphoma: Saudi Lymphoma Group's Clinical Practice Guidelines for Diagnosis, Management and Follow-up.","authors":"Magdy Kandil, Hani Alhashmi, Musa Alzahrani, Ayman Alhejazi, Ibraheem Motabi, Reyad Dada, Mubarak Al-Mansour, Ahmed Sagheir","doi":"10.4103/sjmms.sjmms_97_19","DOIUrl":"10.4103/sjmms.sjmms_97_19","url":null,"abstract":"","PeriodicalId":81993,"journal":{"name":"Meteoritics","volume":"27 1","pages":"202-208"},"PeriodicalIF":1.3,"publicationDate":"2019-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6734739/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85707399","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Can Lay Community Advisors Improve the Clarity of Research Participant Recruitment Materials and Increase the Likelihood of Participation?","authors":"Barbara Bowers, Nora Jacobson, Anna Krupp","doi":"10.1002/nur.21752","DOIUrl":"10.1002/nur.21752","url":null,"abstract":"<p><p>Despite decades of effort, lower income people and ethnic minorities continue to be underrepresented as participants in health research. A group of racially and ethnically diverse, lower income community members (Community Advisors on Research Design and Strategies: CARDS®) was trained to review study designs and procedures and provide recommendations to researchers for increasing participation and making research materials more understandable to members of underrepresented communities. In this mixed methods study, one participant group (n = 55) was shown research materials (recruitment documents and a consent form) developed by a research team and approved by the local IRB. A second group (n = 45) was shown the same materials after they had also been reviewed and revised by CARDS. Interviews, which included both fixed-response and open-ended questions, were used to assess reactions of participants in both groups to the materials, including their hypothetical willingness to volunteer for the research described. Group differences were examined using the Chi-square distribution test. Proportional difference effect sizes were estimated using arcsine transformation. The qualitative data were subjected to conventional content analysis. Participants in the group shown the recruitment materials revised by CARDS were more likely to say they understood the documents, more likely to ask for more information about the study, and more likely to say they would participate in the research. Results of content analysis suggested a four-phase sequential process for deciding whether to participate in the research. © 2016 Wiley Periodicals, Inc.</p>","PeriodicalId":81993,"journal":{"name":"Meteoritics","volume":"1 1","pages":"63-69"},"PeriodicalIF":2.0,"publicationDate":"2017-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1002/nur.21752","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85658393","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Volatiles in unequilibrated ordinary chondrites: Abundances, sources and implications for explosive volcanism on differentiated asteroids","authors":"D. W. Muenow, K. Keil, T. Mccoy","doi":"10.1111/J.1945-5100.1995.TB01161.X","DOIUrl":"https://doi.org/10.1111/J.1945-5100.1995.TB01161.X","url":null,"abstract":"— Keil and Wilson (1993) proposed that, during partial melting of some asteroidal meteorite parent bodies, explosive pyroclastic volcanism accelerated S-rich Fe, Ni-FeS cotectic partial melts into space. These authors argued that this process was responsible for the S-depletion of many of the magmas from which the magmatic iron meteorites formed. This process only requires the presence of a few hundred to thousand ppm of volatiles in asteroids < ∼100 km in radius. If the precursor materials of these magmatic iron meteorite groups were similar in composition to unequilibrated ordinary chondrites, then the volatile contents of the latter may be a measure of the potential effectiveness of the process. Analysis of volatile contents of seven unequilibrated ordinary chondrite falls by dynamic high-temperature mass spectrometry revealed that thousands of ppm of indigeneous volatiles, mostly CO, Cl, Na and S, are released at temperatures near the Fe, Ni-FeS cotectic melting temperature of ∼980 °C. If these volatiles are largely retained in the asteroidal parent bodies until onset of partial melting, S depletion of the residual melt might have been achieved by ejection of S-rich partial Fe, Ni-FeS melts by pyroclastic volcanism.","PeriodicalId":81993,"journal":{"name":"Meteoritics","volume":"30 1","pages":"639-645"},"PeriodicalIF":0.0,"publicationDate":"1995-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1111/J.1945-5100.1995.TB01161.X","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"63676869","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Chemical and physical studies of type 3 chondrites XII: The metamorphic history of CV chondrites and their components","authors":"R. K. Guimon, S. Symes, D. Sears, P. Benoit","doi":"10.1111/J.1945-5100.1995.TB01168.X","DOIUrl":"https://doi.org/10.1111/J.1945-5100.1995.TB01168.X","url":null,"abstract":"Cosmochemistry Group, Department of Chemistry and Biochemistry, The University of Arkansas, Fayetteville, Arkansas 72701, USAIPresent address: Natural Science Division, Missouri Baptist College, St. Louis, Missouri 63142, USA*To whom correspondence should be addressed(Received 1994 December 8; accepted in revised form 1995 August I4)Abstract The induced thermoluminescence (TL) properties of 16 CV and CV-related chondrites, four CKchondrites and Renazzo (CR2) have been measured in order to investigate their metamorphic history. Thepetrographic, mineralogical and bulk compositional differences among the CV chondrites indicate that theTL sensitivity of the -130 °C TL peak is reflecting the abundance of ordered feldspar, especially inchondrule mesostasis, which in turn reflects parent-body metamorphism. The TL properties of 18 samples ofhomogenized Allende powder heated at a variety of times and temperatures, and cathodoluminescencemosaics of Axtell and Coolidge, showed results consistent with this conclusion. Five refractory inclusionsfrom Allende, and separates from those inclusions, were also examined and yielded trends reflectingvariations in mineralogy indicative of high peak temperatures (either metamorphic or igneous) and fairlyrapid cooling. The CK chondrites are unique among metamorphosed chondrites in showing no detectableinduced TL, which is consistent with literature data that suggests very unusual feldspar in these meteorites.Using TL sensitivity and several mineral systems and allowing for the differences in the oxidized andreduced subgroups, the CV and CV-related meteorites can be divided into petrologic types analogous tothose of the ordinary and CO type 3 chondrites. Axtell, Kaba, Leoville, Bali, Arch and ALHA81003 are type3.0-3.1, while ALH84018, Efremovka, Grosnaja, Allende and Vigarano are type 3.2-3.3 and Coolidge andLoongana 001 are type 3.8. Mokoia is probably a breccia with regions ranging in petrologic type from 3.0 to3.2. Renazzo often plots at the end of the reduced and oxidized CV chondrite trends, even when those trendsdiverge, suggesting that in many respects it resembles the unmetamorphosed precursors of the CVchondrites. The low-petrographic types and low-TL peak temperatures of all samples, including the CV3.8chondrites, indicates metamorphism in the stability field of low feldspar (i.e., <800 °C) and a metamorphichistory similar to that of the CO chondrites but unlike that of the ordinary chondrites.INTRODUCTIONVirtually all classes of chondrite have experienced some level ofparent body metamorphism; although in the case of type 1 and 2carbonaceous chondrites the metamorphism involved considerableaqueous alteration. Both the type 3 ordinary chondrites and the COchondrites display mineralogical and petrographic evidence formetamorphic alteration that can be evaluated with a high degree ofprecision using induced thermoluminescence (TL) measurements,although the time-temperature histories of the ordinary and COchondrite","PeriodicalId":81993,"journal":{"name":"Meteoritics","volume":"30 1","pages":"704-714"},"PeriodicalIF":0.0,"publicationDate":"1995-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1111/J.1945-5100.1995.TB01168.X","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"63677152","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Solar-proton-produced neon in shergottite meteorites and implications for their origin","authors":"D. Garrison, M. Rao, D. Bogard","doi":"10.1111/J.1945-5100.1995.TB01172.X","DOIUrl":"https://doi.org/10.1111/J.1945-5100.1995.TB01172.X","url":null,"abstract":"— Measured Ne isotopes in samples of shergottite ALHA77005 show variations in 21Ne/22Ne ratios and 21Ne abundances that are consistent with the presence of two cosmogenic components: a component produced by nuclear interactions of galactic cosmic rays (GCR) and a component produced at shallow shielding depths (∼0–3 cm) by energetic solar flare protons (SCR). We suggest that the 21Ne/22Ne ratio generally can be used to distinguish between SCR and GCR components in many meteorite types. Analysis of cosmogenic Ne produced in chondrite mineral separates, eucrites, and anorthositic lunar rocks, all having diverse major element compositions, indicate that the GCR 21Ne/22Ne ratio increases modestly with relative Mg content. Data for hundreds of chondrite analyses suggest that SCR Ne is present in no more than a very small fraction of chondrites. Examination of literature data for other shergottites, however, indicate that all of these meteorites contain SCR Ne but that it is apparently absent in other SNC meteorites. The ubiquitous presence of SCR Ne in shergottites, in contrast to most other types of meteorites, suggests that the martian origin of shergottites gave them different orbital parameters compared to other meteorites. This in turn may have contributed to slower entry velocities and lesser surface ablation in the atmosphere or even to higher SCR production rates.","PeriodicalId":81993,"journal":{"name":"Meteoritics","volume":"30 1","pages":"738-747"},"PeriodicalIF":0.0,"publicationDate":"1995-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1111/J.1945-5100.1995.TB01172.X","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"63677262","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Recovery of three ordinary chondrites, Rooikop 001–003, from the Namib Desert in Western Namibia","authors":"A. Reid, P. Jakeš, M. Zolensky, R. Miller","doi":"10.1111/J.1945-5100.1995.TB01175.X","DOIUrl":"https://doi.org/10.1111/J.1945-5100.1995.TB01175.X","url":null,"abstract":"— Reconnaissance searches for meteorites were made in five selected areas of western Namibia in 1991. Three new ordinary chondrites (H5, L5, L4/5) were recovered from one of the areas searched.","PeriodicalId":81993,"journal":{"name":"Meteoritics","volume":"30 1","pages":"781-784"},"PeriodicalIF":0.0,"publicationDate":"1995-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1111/J.1945-5100.1995.TB01175.X","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"63677466","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Mineralogical and chemical modification of components in CV3 chondrites: Nebular or asteroidal processing?","authors":"A. Krot, E. Scott, M. Zolensky","doi":"10.1111/J.1945-5100.1995.TB01173.X","DOIUrl":"https://doi.org/10.1111/J.1945-5100.1995.TB01173.X","url":null,"abstract":"— Calcium- and aluminum-rich inclusions (CAIs), chondrules, dark inclusions and matrices in certain CV3 carbonaceous chondrites appear to have been modified by different degrees of late-stage alteration processes that caused significant variations in mineralogy and chemistry. Some chondrules and CAIs are rimmed with fayalitic olivine. Metal in all components may be oxidized and sulphidized to magnetite, Ni-rich metal and sulfides. Silicates in all components are aqueously altered to different degrees to phyllosilicates. Primary minerals in some CAIs experienced Fe-alkali-halogen metasomatism forming nepheline, sodalite, wollastonite, hedenbergite and other secondary minerals. In CV3 chondrites with metasomatized CAIs, nepheline, sodalite, etc. are also present in chondrule mesostases and in matrices. McSween's (1977b) reduced subgroup of CV3 chondrites generally shows minimal alteration of all components and may represent the unaltered precursors for the oxidized CV3 chondrites, which generally show major alteration. Most studies have been focused on specific components in CV3 chondrites and have not considered possible relationships between alteration processes. We infer from the correlated occurrences of the alteration features that they were closely related in time and space and review nebular and asteroidal models for their origins. We prefer an asteroidal model.","PeriodicalId":81993,"journal":{"name":"Meteoritics","volume":"30 1","pages":"748-775"},"PeriodicalIF":0.0,"publicationDate":"1995-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1111/J.1945-5100.1995.TB01173.X","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"63677683","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Cosmogenic nitrogen isotopic disequilibrium observed in meteorites","authors":"N. Sugiura, K. Hashizume, Y. Miura, K. Kiyota, S. Zashu","doi":"10.1111/J.1945-5100.1995.TB01162.X","DOIUrl":"https://doi.org/10.1111/J.1945-5100.1995.TB01162.X","url":null,"abstract":"— The isotopic disequilibrium of N molecules in meteorites was examined. For a large data-set, consisting of mass compositions of N molecules extracted at 1200 °C by stepped combustion of chondrites and eucrites, we find that a cosmogenic-N-enriched component and a normal air-like N component are isotopically disequilibrated with each other. The isotopic composition of the cosmogenic-N-enriched component seems to be variable, although the cause for the variation is not clear. The abundance of indigenous atomic N in silicate minerals seems to be small. Indigenous N in meteoritic silicates, if present, may be present in the form of N molecules.","PeriodicalId":81993,"journal":{"name":"Meteoritics","volume":"30 1","pages":"646-653"},"PeriodicalIF":0.0,"publicationDate":"1995-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1111/J.1945-5100.1995.TB01162.X","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"63676429","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Boron cosmochemistry. Part II: Boron nucleosynthesis and condensation temperature","authors":"Mingzhe Zhai","doi":"10.1111/J.1945-5100.1995.TB01171.X","DOIUrl":"https://doi.org/10.1111/J.1945-5100.1995.TB01171.X","url":null,"abstract":"— The new B solar-system abundance calculated by Zhai and Shaw (1994), 16.9 atoms/106 Si (or 606 atoms/1012 H) is used to reevaluate the different possibilities of LiBeB (except 7Li) nucleosynthesis. The revised abundances support two models: (1) Light elements were formed by continual bombardment of interstellar medium (ISM) by galactic cosmic rays (GCRs), but these galactic cosmic rays should contain a very intense low-energy component, in the form of E−5 which cannot be observed near the Earth due to solar modulation effects; (2) Light elements are a mixture of two sources. In the first source, light elements were synthesized by continual bombardment of interstellar medium by galactic cosmic rays. In the second source, they were made by the interactions of C and O nuclei ejected from supernovae with the H and He in the surrounding gas. The first source constitutes ∼46% of total B. \u0000 \u0000 \u0000 \u0000The Si-normalized and CI-meteorite-normalized abundances of common and volatile elements in carbonaceous chondrites show a linear correlation with their condensation temperatures. Using this relationship and the normalized B abundances in CM, CO, and CV meteorites, we can estimate the B condensation temperature to be ∼910 K, which is similar to Ga.","PeriodicalId":81993,"journal":{"name":"Meteoritics","volume":"30 1","pages":"733-737"},"PeriodicalIF":0.0,"publicationDate":"1995-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1111/J.1945-5100.1995.TB01171.X","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"63677083","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The Roosevelt County 079-090 meteorites","authors":"G. Benedix, L. K. Kinsey, T. Mccoy, K. Keil, R. Wieler","doi":"10.1111/J.1945-5100.1995.TB01176.X","DOIUrl":"https://doi.org/10.1111/J.1945-5100.1995.TB01176.X","url":null,"abstract":"— We have classified 12 new, moderately to severely weathered meteorites from Roosevelt County, New Mexico (RC 079–090) that were recovered between 1969 and 1993. They include nine H chondrites and three L chondrites of petrologic types 4 to 6 and shock classification S1 to S4. Among these are a flight-oriented specimen of an H5 chondrite, an L4 chondrite with a porphyritic impact-melt rock clast, an H5 fragmental breccia with an unusual weathering assemblage (probably a Ca sulfate), and an H4 chondrite with unequilibrated pyroxenes.","PeriodicalId":81993,"journal":{"name":"Meteoritics","volume":"54 1","pages":"788-791"},"PeriodicalIF":0.0,"publicationDate":"1995-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1111/J.1945-5100.1995.TB01176.X","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"63677647","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}