465 research outputs found

    Composition and properties of bovine colostrum: a review

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    International audienceAbstractColostrum is the initial milk secreted by mammals following parturition, the composition and physicochemical properties of which are highly dynamic and variable. The composition and physicochemical properties of colostrum during the initial post-partum period has not been systematically reviewed for many years, although the topic remains of interest both to milk producers and processors. In this article, the current understanding of the composition of colostrum, i.e. carbohydrates, proteins, growth factors, enzymes, enzyme inhibitors, nucleotides and nucleosides, cytokines, fats, vitamins and minerals, is reviewed. In addition, the physicochemical properties, i.e. pH and buffering capacity, colour, density and specific gravity, osmotic pressure, somatic cell count, properties of casein micelles, ethanol stability and rennet coagulation properties are discussed, as well as the effects of heat-treating colostrum

    HST/STIS Ultraviolet Imaging of Polar Aurora on Ganymede

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    We report new observations of the spectrum of Ganymede in the spectral range 1160 - 1720 A made with the Space Telescope Imaging Spectrograph (STIS) on HST on 1998 October 30. The observations were undertaken to locate the regions of the atomic oxygen emissions at 1304 and 1356 A, previously observed with the GHRS on HST, that Hall et al. (1998) claimed indicated the presence of polar aurorae on Ganymede. The use of the 2" wide STIS slit, slightly wider than the disk diameter of Ganymede, produced objective spectra with images of the two oxygen emissions clearly separated. The OI emissions appear in both hemispheres, at latitudes above 40 degrees, in accordance with recent Galileo magnetometer data that indicate the presence of an intrinsic magnetic field such that Jovian magnetic field lines are linked to the surface of Ganymede only at high latitudes. Both the brightness and relative north-south intensity of the emissions varied considerably over the four contiguous orbits (5.5 hours) of observation, presumably due to the changing Jovian plasma environment at Ganymede. However, the observed longitudinal non-uniformity in the emission brightness at high latitudes, particularly in the southern hemisphere, and the lack of pronounced limb brightening near the poles are difficult to understand with current models. In addition to observed solar HI Lyman-alpha reflected from the disk, extended Lyman-alpha emission resonantly scattered from a hydrogen exosphere is detected out to beyond two Ganymede radii from the limb, and its brightness is consistent with the Galileo UVS measurements of Barth et al. (1997).Comment: 7 pages, 4 figures, accepted for publication in ApJ, June 1, 200

    Excitation of the Ganymede Ultraviolet Aurora

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    We analyze the ultraviolet aurorae observed on Ganymede by means of the Hubble Space Telescope and compare them to similar phenomena on Earth. We find that the tenuous nature of Ganymede's atmosphere precludes excitation of the aurora by high-energy electrons and requires a local acceleration mechanism. We propose the following as plausible mechanisms for generating both the continuous background emission and the intense auroral bright spots

    The Evolution and Environments of X-ray Emitting Active Galactic Nuclei in High-Redshift Large-Scale Structures

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    We use deep Chandra imaging and an extensive optical spectroscopy campaign on the Keck 10-m telescopes to study the properties of X-ray point sources in five large-scale structures at redshifts of z ~ 0.7-0.9. We first study X-ray point sources using the statistical measure of cumulative source counts, finding that the measured overdensities are consistent with previous results, but we recommend caution in overestimating the precision of the technique. Optical spectroscopy of objects matched to X-ray point sources confirms a total of 27 AGN within the five structures, and we find that their host galaxies tend to be located away from dense cluster cores. More than 36% of host galaxies are located in the `green valley', which suggests they are a transitional population. Based on analysis of OII and Hd line strengths, the average spectral properties of the AGN host galaxies in all structures indicate either on-going star formation or a starburst within ~ 1 Gyr, and the host galaxies are younger than the average galaxy in the parent population. These results indicate a clear connection between starburst and nuclear activity. We use composite spectra of the spectroscopically confirmed members in each structure to separate them based on a measure of the overall evolutionary state of their constituent galaxies. We define structures as having more evolved populations if their average galaxy has lower EW(OII) and EW(Hd). The AGN in the more evolved structures have lower rest-frame 0.5-8 keV X-ray luminosities (all below 10^43.3 erg s^-1) and longer times since a starburst than those in the less evolved structures, suggesting that the peak of both star formation and AGN activity has occurred at earlier times. With the wide range of evolutionary states and timeframes in the structures, we use our results to analyze the evolution of X-ray AGN and evaluate potential triggering mechanisms.Comment: 29 pages, 13 figure

    Obscured Starburst Activity in High Redshift Clusters and Groups

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    Using Spitzer-MIPS 24um imaging and Keck spectroscopy we examine the nature of the obscured star forming population in three clusters and three groups at z~0.9. These six systems are components of the Cl1604 supercluster, the largest structure imaged by Spitzer at redshifts near unity. We find that the average density of 24um-detected galaxies within the Cl1604 clusters is nearly twice that of the surrounding field and that this overdensity scales with the cluster's dynamical state. The 24um-bright members often appear optically unremarkable and exhibit only moderate [OII] line emission due to severe obscuration. Their spatial distribution suggests they are an infalling population, but an examination of their spectral properties, morphologies and optical colors indicate they are not simply analogs of the field population that have yet to be quenched. Using stacked composite spectra, we find the 24um-detected cluster and group galaxies exhibit elevated levels of Balmer absorption compared to galaxies undergoing normal, continuous star formation. A similar excess is not observed in field galaxies with equivalent infrared luminosities, indicating a greater fraction of the detected cluster and group members have experienced a burst of star formation in the recent past compared to their counterparts in the field. Our results suggest that gas-rich galaxies at high redshift experience a temporary increase in their star formation activity as they assemble into denser environments. Using HST-ACS imaging we find that disturbed morphologies are common among the 24um-detected cluster and group members and become more prevalent in regions of higher galaxy density. We conclude that mergers are the dominant triggering mechanism responsible for the enhanced star formation found in the Cl1604 groups, while a mix of harassment and mergers are likely driving the activity of the cluster galaxies.Comment: 18 pages, 19 figures, submitted to Ap

    Preferred reporting items for journal and conference abstracts of systematic reviews and meta-analyses of diagnostic test accuracy studies (PRISMA-DTA for Abstracts):checklist, explanation, and elaboration

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    For many users of the biomedical literature, abstracts may be the only source of information about a study. Hence, abstracts should allow readers to evaluate the objectives, key design features, and main results of the study. Several evaluations have shown deficiencies in the reporting of journal and conference abstracts across study designs and research fields, including systematic reviews of diagnostic test accuracy studies. Incomplete reporting compromises the value of research to key stakeholders. The authors of this article have developed a 12 item checklist of preferred reporting items for journal and conference abstracts of systematic reviews and meta-analyses of diagnostic test accuracy studies (PRISMA-DTA for Abstracts). This article presents the checklist, examples of complete reporting, and explanations for each item of PRISMA-DTA for Abstracts

    A genome-wide scan for common alleles affecting risk for autism

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    Although autism spectrum disorders (ASDs) have a substantial genetic basis, most of the known genetic risk has been traced to rare variants, principally copy number variants (CNVs). To identify common risk variation, the Autism Genome Project (AGP) Consortium genotyped 1558 rigorously defined ASD families for 1 million single-nucleotide polymorphisms (SNPs) and analyzed these SNP genotypes for association with ASD. In one of four primary association analyses, the association signal for marker rs4141463, located within MACROD2, crossed the genome-wide association significance threshold of P < 5 × 10−8. When a smaller replication sample was analyzed, the risk allele at rs4141463 was again over-transmitted; yet, consistent with the winner's curse, its effect size in the replication sample was much smaller; and, for the combined samples, the association signal barely fell below the P < 5 × 10−8 threshold. Exploratory analyses of phenotypic subtypes yielded no significant associations after correction for multiple testing. They did, however, yield strong signals within several genes, KIAA0564, PLD5, POU6F2, ST8SIA2 and TAF1C

    The Vehicle, Fall 1993

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    Table of Contents 7/10ths SynthesisPeter F. Essigpage 5 Aug 1992 (My Small Catechism)Jon Montgomerypage 6 Chaos Is-J. Dylan McNeillpage 7 UntouchedTraci Williamspage 8 The JustificationJohn C. Carminepage 8 LincolnJon Montgomerypage 9 Untitled (Photo)Nicole Niemanpage 10 Park PoemJohn Brillhartpage 11 SmokeJulia Ann Canhampage 12 Warming the BenchAnn Moutraypage 12 Cereal KillerJay Harnackpage 13 The Dutiful SonsTom McGrathpage 14 UntitledCatherine DeGraafpage 17 7-up bottleWalt Howardpage 17 BreedDan Trutterpage 18 An Argument Against LoveTony Martinezpage 19 UntitledT. Scott Laniganpage 19 Glassblowers BallStephanie Franzenpage 20 Portrait of a Young GirlJohn C. Carminepage 20 Untitled (artwork)Dan Trutterpage 21 Death of a FriendLizabeth Kulkapage 22 Submission BluesMartin Paul Brittpage 23 To the Fourteen Year Old SuicideScott Langenpage 23 The Flabby PilgrimTom McGrathpage 24 The Fall of ImmortalityBrian Wheelerpage 25 Merging with AirThom Schnarrepage 26 UntitledCatherine DeGraafpage 27 Tree FishSandra Beauchamppage 28 Country SlumberJ. Dylan McNeillpage 29 Untitled (artwork)Dan Trutterpage 33 Authors\u27 Pagepage 34https://thekeep.eiu.edu/vehicle/1060/thumbnail.jp
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