264 research outputs found

    Antioxidative Properties of Bitter Gourd (Momordica charantia) and Zucchini (Cucurbita pepo)

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    The enzymatic and non-enzymatic antioxidative capacities of bitter gourd (Momordica charantia) and zucchini (Cucurbita pepo) were investigated in water extracts and chemical buffer extracts. Bitter gourd and zucchini fruits were purchased from a farmer’s market and homogenized separately in water and in a native enzyme extraction buffer. Total phenolic compounds, free radical DPPH scavenging activity, SOD activity and β- glucosidase activity were assayed in the extracts. The average total phenolic compounds recorded in bitter gourd were 13.28 GAE/g fresh weights while in zucchini, the average was 8.67GAE/g fresh weight. This study also found that bitter gourd was 82.05% as effective as ascorbic acid in inhibiting the free radical DPPH while zucchini was 12.19% as effective. The results indicated that bitter gourd was significantly higher in antioxidant content and in β-glucosidase activities than zucchini (P\u3c0.05). On the other hand, significantly higher SOD activities were recorded in zucchini than in bitter gourd extracts

    UBVRI Light Curves of 44 Type Ia Supernovae

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    We present UBVRI photometry of 44 type-Ia supernovae (SN Ia) observed from 1997 to 2001 as part of a continuing monitoring campaign at the Fred Lawrence Whipple Observatory of the Harvard-Smithsonian Center for Astrophysics. The data set comprises 2190 observations and is the largest homogeneously observed and reduced sample of SN Ia to date, nearly doubling the number of well-observed, nearby SN Ia with published multicolor CCD light curves. The large sample of U-band photometry is a unique addition, with important connections to SN Ia observed at high redshift. The decline rate of SN Ia U-band light curves correlates well with the decline rate in other bands, as does the U-B color at maximum light. However, the U-band peak magnitudes show an increased dispersion relative to other bands even after accounting for extinction and decline rate, amounting to an additional ~40% intrinsic scatter compared to B-band.Comment: 84 authors, 71 pages, 51 tables, 10 figures. Accepted for publication in the Astronomical Journal. Version with high-res figures and electronic data at http://astron.berkeley.edu/~saurabh/cfa2snIa

    Light and flow regimes regulate the metabolism of rivers

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    Mean annual temperature and mean annual precipitation drive much of the variation in productivity across Earth's terrestrial ecosystems but do not explain variation in gross primary productivity (GPP) or ecosystem respiration (ER) in flowing waters. We document substantial variation in the magnitude and seasonality of GPP and ER across 222 US rivers. In contrast to their terrestrial counterparts, most river ecosystems respire far more carbon than they fix and have less pronounced and consistent seasonality in their metabolic rates. We find that variation in annual solar energy inputs and stability of flows are the primary drivers of GPP and ER across rivers. A classification schema based on these drivers advances river science and informs management.We thank Ted Stets, Jordan Read, Tom Battin, Sophia Bonjour, Marina Palta, and members of the Duke River Center for their help in developing these ideas. This work was supported by grants from the NSF 1442439 (to E.S.B. and J.W.H.), 1834679 (to R.O.H.), 1442451 (to R.O.H.), 2019528 (to R.O.H. and J.R.B.), 1442140 (to M.C.), 1442451 (to A.M.H.), 1442467 (to E.H.S.), 1442522 (to N.B.G.), 1624807 (to N.B.G.), and US Geological Survey funding for the working group was supported by the John Wesley Power Center for Analysis and Synthesis. Phil Savoy contributed as a postdoc- toral associate at Duke University and as a postdoctoral associate (contractor) at the US Geological Survey

    Prime movers : mechanochemistry of mitotic kinesins

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    Mitotic spindles are self-organizing protein machines that harness teams of multiple force generators to drive chromosome segregation. Kinesins are key members of these force-generating teams. Different kinesins walk directionally along dynamic microtubules, anchor, crosslink, align and sort microtubules into polarized bundles, and influence microtubule dynamics by interacting with microtubule tips. The mechanochemical mechanisms of these kinesins are specialized to enable each type to make a specific contribution to spindle self-organization and chromosome segregation

    Nanostructures, Technology, Research, and Applications

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    Contains reports on the nanostructures laboratory, eighteen research projects and a list of publications.Joint Services Electronics Program Grant DAAH04-95-1-0038Semiconductor Research Corporation Contract 95-LJ-550National Science Foundation Grant ECS 94-07078U.S. Army Research Office Grant DAAH04-95-1-0564Defense Advanced Research Projects Agency/Naval Air Systems Command Contract N00019-95-K-0131National Aeronautics and Space Administration Contract NAS8-38249National Aeronautics and Space Administration Grant NAGW-2003IBM Corporation Contract 1622U.S. Navy- Office of Naval Research Grant N00014-95-1-1297U.S. Army Research Office Grant DAAH04-94-G-0377U.S. Air Force - Office of Scientific Research Grant F-49-620-92-J-0064U.S. Air Force - Office of Scientific Research Grant F-49-620-95-1-031

    Nanostructures Technology, Research, and Applications

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    Contains reports on twenty research projects and a list of publications.Joint Services Electronics Program Contract DAAL03-92-C-0001Semiconductor Research Corporation Contract 94-MJ-550U.S. Army Research Office Grant DAAL03-92-G-0291Advanced Research Projects Agency/Naval Air Systems Command Contract N00019-92-K-0021National Science Foundation Grant ECS 90-16437National Science Foundation Grant ECS 90-16737IBM Corporation Contract 1622U.S. Air Force - Office of Scientific Research Grant F-49-62-92-J-0064National Science Foundation Grant DMR 87-19217National Science Foundation Grant DMR 90-22933National Aeronautics and Space Administration Contract NAS8-3674

    Nanostructures Technology, Research, and Applications

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    Contains reports on seventeen research projects and a list of publications.Joint Services Electronics Program Contract DAAL03-92-C-0001Joint Services Electronics Program Grant DAAH04-95-1-0038Semiconductor Research Corporation Contract 94-MJ-550National Science Foundation Grant ECS 94-07078U.S. Army Research Office Contract DAAL03-92-G-0291Advanced Research Projects Agency/Naval Air Systems Command Contract N00019-92-K-0021National Aeronautics and Space Administration Contract NAS8-36748National Aeronautics and Space Administration Grant NAGW-2003IBM Corporation Contract 1622U.S. Army Research Office Grant DAAH04-94-G-0377U.S. Air Force - Office of Scientific Research Grant F-49-620-92-J-006
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