1,498 research outputs found

    Isotopic and Microstructural Analyses of Opaque Mineral Assemblages and Their Alteration Products Hosted in a Refractory Inclusion

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    Calcium-aluminum-rich inclusions (CAIs) hosted in primitive meteorites are the oldest solids formed in the Solar System. Some CAIs contain metal nuggets that are complex assemblages of Fe-Ni alloys, along with rare ultra-refractory metals such as platinum group elements (PGEs), and their alteration products such as magnetite, sulfides, and phosphates. Three possible mechanisms proposed to explain the origin of these metal nuggets include condensation in circumstellar settings, condensation in the solar nebula within the CAI-forming region, or crystallization from immiscible metal-silicate melt. However, secondary alteration processes may have also affected some of these assemblages. Additionally, similar metal assemblages observed in chondrules and chondritic matrix indicate that all of these metal nuggets could share common high-temperature origins. These metal assemblages record early Solar System conditions that are reflected in their distinctive chemical composition, mineralogy and microstructures. Here we report a detailed mineralogical, microstructural and oxygen isotopic study of one such metal assemblage hosted in a CAI to understand the physical and chemical settings in which it formed

    A PHARMACOGNOSTIC AND PHARMACOLOGICAL REVIEW ON ALSTONIA SCHOLARIS

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    Alstonia scholaris, commonly known as devil's tree, is an important medicinal plant in the various folk and traditional systems of medicine in Asia, Australia, and Africa. The plant is used in Ayurvedic, Unani, and Siddha types of alternative medicinal systems. The decoction, mostly prepared from the bark, is used to treat a variety of diseases, of which the most important is malaria. In Ayurveda, it is used as a bitter and as an astringent herb for treating skin disorders, malarial fever, urticaria, chronic dysentery, diarrhea, and in snake bite. A. scholaris is also observed to possess antioxidant, immunomodulatory effects, and free radical scavenging, anti-inflammatory, antimutagenic, anticancer, analgesic, hepatoprotective, wound healing, antidiarrheal, and antiplasmodial activities. The current review summarizes the numerous ethnobotanical and traditional uses as well as the phytochemical and pharmacological report on A. scholaris

    Oxygen Isotopic Imaging of Refractory Inclusions from the Miller Range (MIL) 090019 CO3 Chondrite: A Perovskite Perspective

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    Calcium-Aluminum-rich Inclusions (CAIs) in primitive meteorites are the first solids to condense in the Solar System. The oxygen isotopic compositions recorded in various mineral components of CAIs provide clues about their origins and post-formation histories, recording processes such as condensation, melting, nebular alteration, and fluidrock reactions on the parent body. MIL 090019 is similar to some rare carbonaceous chondrites such as Acfer 094, DOM 08004/6 and ALH 77303 that contain high abundances of a variety of refractory inclusions. This provides an opportunity to study the oxygen isotopic record of different types of refractory inclusions within the same meteorite. We analyzed CAIs specifically targeting primary minerals that are direct nebular condensates, such as corundum and perovskite, with the goal of gaining insights into the O isotopic composition of the nebular gas(es) from which these CAIs condensed. As MIL 090019 is a classified as CO3.1, it shows some signs of thermal metamorphism, compared to the more primitive CO3 meteorites (e.g., DOM 08004/06). A second goal of this study is to search for evidence of nebular processes in phases such as perovskite and melilite that are susceptible to parent body alteration to varying degrees. We analyzed the oxygen isotopic compositions of various CAIs from the MIL 090019 CO3 carbonaceous chondrite by ion imaging using the NanoSIMS 50L (Nano Secondary Ion Mass Spectrometer) at JSC following methods described in. An advantage of ion imaging over traditional spot analyses is that it provides spatial context to the oxygen isotopic data. This work builds on previously reported oxygen isotopic composition of two other CAIs (CAI-44 and CAI-E2) from the same meteorite thin section

    Attitudes of College Students towards Agriculture, Food and the Role of Government

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    In 2002 and 2007 we surveyed Agribusiness students’ attitudes about agriculture, farming, food and agricultural policies. Responses were analyzed by year and student characteristics including farm background, citizenship and gender. Citizenship was a significant variable explaining differences in agreement with statements. Year and interactions with year were not significant.agricultural policy, farming, logistic regression, student attitudes, Agricultural and Food Policy, Teaching/Communication/Extension/Profession, A13, A22, C42, Q18,

    Effect of Gender on Environmental Awareness of Post-Graduate Students

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    Aims: It was aimed in the present study to explore the effect of gender on environmental awareness of the post-graduate students. When education diversity was controlled to be science and social-science the environmental awareness was expected to be influenced by the gender of individuals. Study Design: In order to test the above objective the present study used comparative analyses in respect of the gender taking the subjects from science and social-science discipline represented from different areas. Place and Duration of Study: Place of the study was the post-graduate students selected from Karnatak and Bangalore Universities of Karnataka State, duration of the study was between February 2011 to July 2012. Methodology: The students of science discipline pursuing their 3rd semester of course in Botany, Chemistry, Geography, Geology, Applied Genetics, Physics and Zoology in Karnatak and Bangalore Universities were included in the study. However, in the Bangalore University the environmental science students were added to the science discipline as the course is offered in the university. The students included for the social-science discipline were from 3rd semester courses of Economics, History, Political Science, Social Work and Sociology. On the subjects the environmental awareness test developed by Jha (1998) was administered in group and the responses were obtained by the subjects. Sample: The included total subjects for the study were 605 post-graduate students comprising from science and social-science discipline. The age range of the students was between 22 to 24 years. For the obtained data after calculating mean and SD for the groups, ‘t’ analyses was carried out to find significant difference between the groups. Results: Statistical results using the ‘t’ test revealed no significant difference between the male and the female students of both science and social-science students of Karnatak University (Dharwad Science Male mean 50.54 (SD 11.15)/Female mean 51.41 (SD 08.15), ‘t’ 0.54, p>0.05. Dharwad Social-Science Male mean 51.02 (SD 09.07)/Female mean 51.68 (SD 07.34),‘t’ 0.51, p>0.05). The study also did not find significant difference between the male and the female science students of Bangalore university. However, there was difference between the social-science students in relation to their gender, the awareness results favouring the females (Bangalore Science Male mean 49.75 (SD 11.73)/Female mean 53.97, (SD 07.37), ‘t’ 2.26, p0.05). Conclusion: It was evidenced in the present study that gender has no significant effect on environmental awareness of the post-graduate students. Out of the four comparative analyses, in three the results are in accordance with the hypothesis and in one comparative analysis it was found that the females have higher environmental awareness. This implies that gender significance study on effect of environmental awareness needs further careful verification with control of other variables

    Capturing an Evolving Nebular Environment: A Petrographic and Geochemical Study of a Type A, B & C CAI

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    Calcium, Aluminum-rich Inclusions (CAIs) were the first formed solids in our Solar System, with mineral assemblages reflecting the first phases predicted to condense out of a hot nebular gas of Solar composition. Geochemical, textural and crystallographic information in CAIs can be used to constrain the temperature, pressure, and composition (e.g., oxygen fugacity) of the gaseous reservoir(s) from which they formed, as well as any secondary (nebular and parent body) processes they underwent. Coordinated geochemical and textural analyses provide information on nebular conditions (i.e., astrophysical environments and dynamics of nebular gas reservoirs) in which these CAIs formed. In order to better understand the evolution of nebular reservoirs at the time of CAI formation, we analyzed a Type A, B and C CAI using Electron Probe Micro-Analyzer (EPMA) and Electron BackScatter Diffraction (EBSD) at NASA Johnson Space Center (JSC)

    A review of volatiles in the Martian interior

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    Multiple observations from missions to Mars have revealed compelling evidence for a volatile-rich Martian crust. A leading theory contends that eruption of basaltic magmas was the ultimate mechanism of transfer of volatiles from the mantle toward the surface after an initial outgassing related to the crystallization of a magma ocean. However, the concentrations of volatile species in ascending magmas and in their mantle source regions are highly uncertain. This work and this special issue of Meteoritics & Planetary Science summarize the key findings of the workshop on Volatiles in the Martian Interior (Nov. 3–4, 2014), the primary open questions related to volatiles in Martian magmas and their source regions, and the suggestions of the community at the workshop to address these open questions

    Effect of nutrition on copper and zinc concentrations in human milk

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    Background: The gross composition of human milk is remarkably constant among women of varying nutritional status. Reliable information is now available on the content, and the principal factor affecting it, of most of the trace elements on human milk. However, for some of the trace elements, there is still a wide variation in reported values in the literature, which is due at least in part, to analytical difficulties. Hence this study was taken up to find out if maternal nutritional status influences the copper and zinc concentrations in colostrum of mother.Methods: Total of 100 mothers were enrolled in the study after obtaining prior informed consent. They were divided into 2 groups - group I had 50 malnourished mothers and group II had 50 well-nourished mothers. Sample digestion was attempted with different quantities of various acids. Analysis of digested colostrum was carried out for copper and zinc.Results: The mean levels of copper and zinc were slightly more among well-nourished than malnourished women. Values of copper were significantly higher in the colostrum of well-nourished as compared to that of the malnourished mothers.Conclusions: The parameters of weight, height weight/height ratio and hemoglobin varied significantly between the well-nourished and malnourished mothers. The difference in milk content of malnourished and well-nourished mothers is not significant for zinc. However, copper levels were significantly higher in well-nourished mothers
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