53 research outputs found

    Particulate amino acids in the sea: Effects of primary productivity and biological decomposition

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    We measured the flux of amino acids associated with sinking particles collected by sediment traps at two Pacific Ocean sites. These results were compared with results from six other sites where we and others have measured amino acid fluxes. This comparison shows that the flux of amino acids on sinking particles is related to primary productivity. This relationship exists in spite of differences in the oceanic regimes sampled and in the sediment traps, bactericides, and amino acid analysis techniques used. The amount of particulate amino acids leaving the euphotic zone in areas of higher productivity is a higher proportion of the primary production than in less productive areas. And, a larger amount of particulate amino acids reaches deeper waters in more productive areas. However, the particulate amino acids leaving the euphotic zone decompose faster with depth in more productive areas. Faster decomposition below the surface waters in areas of high productivity suggests that (1) decomposition of particulate organic matter may be mediated more by zooplankton and less by microbial processes than in areas of lower productivity, or (2) phytoplankton growing in more productive areas are more easily remineralized than those growing in less productive areas

    The vertical flux of particulate organic nitrogen in the sea: Decomposition of amino acids in the Peru upwelling area and the equatorial Atlantic

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    Marine particulate matter samples were collected in moored and free-drifting sediment traps deployed off the coast of Peru during February, 1978. Three types of amino acids were analyzed in these samples: free extractable amino acids (FEA), hydrolyzed extractable amino acids (HEA) and total hydrolyzed amino acids (fHA). FEA and HEA were also analyzed in moored trap samples from the PARFLUX E station in the equatorial Atlantic Ocean...

    Sexual selection, automata and ethics in George Eliot's The Mill on the Floss and Olive Schreiner's Undine and From Man to Man

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    This paper brings together two related areas of debate in the latter half of the nineteenth century. The first concerns how the courtship plot of the nineteenth-century novel responded to, and helped to shape, scientific ideas of sexual competition and selection. In The Mill on the Floss (1860), George Eliot strikingly prefigures Darwin's later work on sexual selection, drawing from her own extensive knowledge of the wider debates within which evolutionary theory developed. Maggie Tulliver's characterisation allows Eliot to explore the ethical complexities raised by an increasingly powerful scientific naturalism, where biology is seen to be embedded within morality in newly specific ways. The second strand of the paper examines the extension of scientific method to human mind and motivation which constituted the new psychology. It argues that there are crucial continuities of long-established ethical and religious ideas within this increasingly naturalistic view of human mind and motivation. The contention that such ideas persist and are transformed, rather than simply jettisoned, is illustrated through the example of Thomas Henry Huxley's 1874 essay on automata. Turning finally to focus on Olive Schreiner's Undine (1929) and From Man to Man (1926), the paper explores the importance of these persistent ethical and religious ideas in two novels which remained unpublished during her lifetime. It argues that they produce both difficulty and opportunity for imagining love plots within the context of increasingly assertive biological and naturalistic accounts of human beings

    Diagnostic and treatment characteristics of polycystic ovary syndrome: descriptive measurements of patient perception and awareness from 657 confidential self-reports

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    BACKGROUND: This investigation was undertaken to describe patient perception and awareness of the polycystic ovary syndrome (PCOS), the most common cause of anovulation/oligoovulation among women of reproductive age. METHODS: Fifteen parameters were evaluated by a computer-based research instrument accessed by a large, unscreened population. Incomplete questionnaires were not entered, and responses were electronically tabulated to block duplicate submissions. RESULTS: From 657 participants, the majority (63%) were between 26–34 years old; mean BMI was 30.4 kg/m(2). 343 of 657 had at least one pregnancy and 61% of the study group had taken fertility medicine (any type) at least once. Physicians were the most common provider of PCOS information for all study participants, irrespective of age. Patient emotions associated with the diagnosis of PCOS included "frustration" (67%), "anxiety" (16%), "sadness" (10%), and "indifference" (2%). Self-reported patient aptitude regarding PCOS was scored as high or "very aware" in >60% of women. Respondents were also asked: "If your PCOS could be safely and effectively helped by something else besides fertility drugs or birth control pills, would that interest you?" Interest in alternative PCOS treatments was expressed by 99% of the sample (n = 648). CONCLUSIONS: In our study population, most women associated negative emotions with PCOS although the self-reported knowledge level for the disorder was high. While these women regarded their obstetrician-gynecologist as integral to their PCOS education, traditional PCOS therapies based on oral contraceptives or ovulation induction agents were regarded as unsatisfactory by most women

    Science opportunities with solar sailing smallsats

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    Recently, we witnessed how the synergy of small satellite technology and solar sailing propulsion enables new missions. Together, small satellites with lightweight instruments and solar sails offer affordable access to deep regions of the solar system, also making it possible to realize hard-to-reach trajectories that are not constrained to the ecliptic plane. Combining these two technologies can drastically reduce travel times within the solar system, while delivering robust science. With solar sailing propulsion capable of reaching the velocities of ~5-10 AU/yr, missions using a rideshare launch may reach the Jovian system in two years, Saturn in three. The same technologies could allow reaching solar polar orbits in less than two years. Fast, cost-effective, and maneuverable sailcraft that may travel outside the ecliptic plane open new opportunities for affordable solar system exploration, with great promise for heliophysics, planetary science, and astrophysics. Such missions could be modularized to reach different destinations with different sets of instruments. Benefiting from this progress, we present the "Sundiver" concept, offering novel possibilities for the science community. We discuss some of the key technologies, the current design of the Sundiver sailcraft vehicle and innovative instruments, along with unique science opportunities that these technologies enable, especially as this exploration paradigm evolves. We formulate policy recommendations to allow national space agencies, industry, and other stakeholders to establish a strong scientific, programmatic, and commercial focus, enrich and deepen the space enterprise and broaden its advocacy base by including the Sundiver paradigm as a part of broader space exploration efforts.Comment: 34 pages, 12 figures, 2 table

    Long Term Patient Centered Outcomes Following Oral Appliance Therapy for Obstructive Sleep Apnea

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    The long-term patient-centered outcomes of oral appliance therapy (OAT) for management of obstructive sleep apnea (OSA) are not well understood. This study aims to assess the general and condition specific quality of life and perceived occlusal and functional changes of individuals with OSA who had OAT delivery two years or longer ago. 3 validated (SAQLI, SF-36, PSPOF) and 1 custom (Oral Compliance) questionnaire were mailed to 139 identified patients from the UNC School of Dentistry Sleep Clinic who had met inclusion criteria of: a PSG diagnosis of OSA, age 18-60 at time of OAT delivery and had delivery of OAT 2 years or longer ago for management of OSA. 31 patients, 58% male with mean age of 49 returned completed questionnaires. 58% of these patients continued to wear OAT for a mean 4.9 years (SD=1.77), and those who discontinued OAT reported use of CPAP, weight loss, BSSO, or nothing to manage their OSA. For quality of life, there were no statistically significant average differences between wearers and non-wearers of OAT in regards to PSPOF or SF-36 subscores. In the SAQLI, those that continued OAT reported greater perception of general health than non-wearers. Non-wearers reported significantly greater problems with side effects from current treatment for OSA than wearers did from OAT. The long-term adherence to OAT was high suggesting quality of life benefits to this type of therapy for managing OSA. Long term OAT adherence is a function of patients’ perceptions to both the conferred benefits of treatment and the unfavorable treatment induced side effects.Master of Scienc

    Evidence-Based Decision Making: Global Evidence, Local Decisions

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