770 research outputs found

    Geochemistry of Kauai shield-stage lavas: Implications for the chemical evolution of the Hawaiian plume

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    We measured He, Sr, Nd, Pb, and Os isotope ratios and major and trace element concentrations in stratigraphically and paleomagnetically controlled shield-stage lavas from Kauai, Hawaii. The range of 3He/4He ratios (17–28 RA) from Kauai is similar to that reported from Loihi and thus challenges the prevailing notion that high 3He/4He ratios are restricted to the preshield stage of Hawaiian magmatism. 3He/4He ratios vary erratically with stratigraphic position, and chronostratigraphic control from paleomagnetic data indicates very rapid changes in the 3He/4He ratios (up to 8 RA in ~102 years). These variations in helium isotopic ratios are correlated with variations in radiogenic isotope ratios, suggesting rapid changes in melt composition supplying the magma reservoir. A three-component mixing model, previously proposed for Hawaiian shield lavas, does not adequately explain the isotopic data in Kauai shield lavas. The addition of a depleted-mantle (DM) component with the isotopic characteristics similar to posterosional basalts explains the isotopic variability in Kauai shield lavas. The DM component is most apparent in lavas from the Kauai shield and is present in varying proportion in other Hawaiian shield volcanoes. Shield lavas from Kauai sample a high 3He/4He end-member (Loihi component), but while lavas from western Kauai have a larger contribution from the Kea component (high 206Pb/204Pb, anomalously low 207Pb/204Pb relative to 206Pb/204Pb), lavas from eastern Kauai have a larger proportion of an enriched (Koolau) component. The systematic isotopic differences between eastern and western Kauai reflect a gradual migration of the locus of volcanism from west to east, or alternatively east and west Kauai are two distinct shield volcanoes. In the latter case, the two shield volcanoes have maintained distinct magma supply sources and plumbing systems. Our new geochemical data from Kauai are consistent with the existence of a single high 3He/4He reservoir in the Hawaiian plume and suggest that the proportion of the different mantle components in the plume have changed significantly in the past 5 Myr. The long-term evolution of the Hawaiian plume and the temporal variability recorded in Kauai lavas require more complex geochemical heterogeneities than suggested by radially zoned plume models. These complexities may arise from heterogeneities in the thermal boundary layer and through variable entrainment of ambient mantle by the upwelling plume

    Interactive media for parental education on managing children chronic condition: a systematic review of the literature

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    BackgroundAlthough some research has examined the use of games for the education of pediatric patients, the use of technology for parental education seems like an appropriate application as it has been a part of the popular culture for at least 30years. The main objective of this systematic review is to examine the literature for research evaluating the use of interactive media in the education of parents of children with chronic conditions.MethodsWe searched the MEDLINE, PSYCHINFO, CINAHL, Cochrane database of systematic reviews and EMBASE databases from 1986 to 2014 seeking original investigations on the use of interactive media and video games to educate parents of children with chronic conditions. Cohort studies, randomized control trials, and observational studies were included in our search of the literature.Two investigators reviewed abstracts and full texts as necessary. The quality of the studies was assessed using the GRADE guidelines.Overall trend in the results and the degree of certainty in the results were considered when assessing the body of literature pertaining to our focused questions.ResultsOur initial search identified 4367 papers, but only 12 fulfilled the criterion established for final analysis, with the majority of the studies having flaws that reduced their quality. These papers reported mostly positive results supporting the idea that parent education is possible through interactive media.ConclusionWe found limited evidence of the effectiveness of using serious games and or interactive media to educate parents of children with chronic conditions.Electronic supplementary materialThe online version of this article (doi:10.1186/s12887-015-0517-2) contains supplementary material, which is available to authorized users

    Transportation economics for Arctic petroleum resources.

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    Massachusetts Institute of Technology. Dept. of Naval Architecture and Marine Engineering. Thesis. 1970. M.S.MICROFICHE COPY ALSO AVAILABLE IN BARKER ENGINEERING LIBRARY.Bibliography: leaf 52.M.S

    Take Care- Use Antibiotics Responsibly Swine Practitioner Project

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    The Take Care - Use Antibrotics ResponsiblyÂź program is an antimicrobial resistance and use educat1on and awareness program for pork producers. The program is based on principles and guidelines intended to minimize the development of antimicrobial resistance whrle maximizing animal health The program was developed by the National Pork Board, but veterinarians are key in the delivery of the program on farm. Since there are many factors that contribute to the amounts and types of antimicrobrals used on farm it was decided that the best way to measure program effectiveness was through measurement of changes in the attitude and behaviors of program particrpants

    Knowledge of Objective 'Oughts': Monotonicity and the New Miners Puzzle

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    In the classic Miners case, an agent subjectively ought to do what they know is objectively wrong. This case shows that the subjective and objective ‘oughts’ are somewhat independent. But there remains a powerful intuition that the guidance of objective ‘oughts’ is more authoritative—so long as we know what they tell us. We argue that this intuition must be given up in light of a monotonicity principle, which undercuts the rationale for saying that objective ‘oughts’ are an authoritative guide for agents and advisors

    Progesterone signalling in broiler skeletal muscle is associated with divergent feed efficiency

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    Background: We contrast the pectoralis muscle transcriptomes of broilers selected from within a single genetic line expressing divergent feed efficiency (FE) in an effort to improve our understanding of the mechanistic basis of FE. Results: Application of a virtual muscle model to gene expression data pointed to a coordinated reduction in slow twitch muscle isoforms of the contractile apparatus (MYH15, TPM3, MYOZ2, TNNI1, MYL2, MYOM3, CSRP3, TNNT2), consistent with diminishment in associated slow machinery (myoglobin and phospholamban) in the high FE animals. These data are in line with the repeated transition from red slow to white fast muscle fibres observed in agricultural species selected on mass and FE. Surprisingly, we found that the expression of 699 genes encoding the broiler mitoproteome is modestly–but significantly–biased towards the high FE group, suggesting a slightly elevated mitochondrial content. This is contrary to expectation based on the slow muscle isoform data and theoretical physiological capacity arguments. Reassuringly, the extreme 40 most DE genes can successfully cluster the 12 individuals into the appropriate FE treatment group. Functional groups contained in this DE gene list include metabolic proteins (including opposing patterns of CA3 and CA4), mitochondrial proteins (CKMT1A), oxidative status (SEPP1, HIG2A) and cholesterol homeostasis (APOA1, INSIG1). We applied a differential network method (Regulatory Impact Factors) whose aim is to use patterns of differential co-expression to detect regulatory molecules transcriptionally rewired between the groups. This analysis clearly points to alterations in progesterone signalling (via the receptor PGR) as the major driver. We show the progesterone receptor localises to the mitochondria in a quail muscle cell line. Conclusions: Progesterone is sometimes used in the cattle industry in exogenous hormone mixes that lead to a ~20% increase in FE. Because the progesterone receptor can localise to avian mitochondria, our data continue to point to muscle mitochondrial metabolism as an important component of the phenotypic expression of variation in broiler FE

    Damping Mechanisms for Microgravity Vibration Isolation (MSFC Center Director's Discretionary Fund Final Report, Project No. 94-07)

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    As a research facility for microgravity science, the International Space Station (ISS) will be used for numerous investigations such as protein crystal growth, combustion, and fluid mechanics experiments which require a quiescent acceleration environment across a broad spectrum of frequencies. These experiments are most sensitive to low-frequency accelerations and can tolerate much higher accelerations at higher frequency. However, the anticipated acceleration environment on ISS significantly exceeds the required acceleration level. The ubiquity and difficulty in characterization of the disturbance sources precludes source isolation, requiring vibration isolation to attenuate the anticipated disturbances to an acceptable level. This memorandum reports the results of research in active control methods for microgravity vibration isolation

    Children’s trait and emotion attributions in socially ambiguous and unambiguous situations.

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    Children's attributions about story characters in ambiguous and unambiguous social situations were assessed. One hundred and forty-four 6–7-year-olds and 10–11-year-olds heard about actors who slighted a recipient intentionally or for an undetermined reason and then made causal attributions about the events, an emotion attribution about the recipient, and global personality attributions about the actors and recipient. Relations between perceived self-competence and attribution style were also assessed. Participants were more likely to make negative causal attributions in the unambiguous condition and with increasing age. Older girls and younger boys were more likely than other groups to attribute negative emotions to the recipient. Overall, participants perceived recipients positively and actors negatively. Perceived self-competence was positively correlated with actor attributions, although these differed by age and gender. Implications for children's psychosocial adjustment are discussed
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