6,063 research outputs found

    The effects of the pollutant, sodium cyanide, on the morphology and physiology of oedogonium cardiacum

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    OEDOGONIUM cardiacum exposed to varying concentrations of sodium cyanide for 15 day periods exhibited both morphological and physiological alterations. Organisms were exposed to the pollutant in concentrations of 1, 10, 25, 50, and 100 parts per million. Exposure period for organisms in each concentration was 15 days. As the concentration of the pollutant increased fragmentation also increased. Exposure also caused organisms to lose chlorophyll. The third morphological alteration was the incidence of rupture. Physiological effects altered by exposure included: reduced oxygen evolution, retardation of starch production and death. Death occurs when organisms are exposed to high concentrations over the total 15 day period

    Comments on "The long-period Galactic Cepheid RS Puppis. I. A geometric distance from its light echoes"

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    The luminous Galactic Cepheid RS Puppis is unique in being surrounded by a dust nebula illuminated by the variable light of the Cepheid. In a recent paper in this journal, Kervella et al. (2008) report a very precise geometric distance to RS Pup, based on measured phase lags of the light variations of individual knots in the reflection nebula. In this commentary, we examine the validity of the distance measurement, as well as the reality of the spatial structure of the nebula determined by Feast (2008) based upon the phase lags of the knots. {Kervella et al. assumed that the illuminated dust knots lie, on average, in the plane of the sky (otherwise it is not possible to derive a geometric distance from direct imaging of light echoes). We consider the biasing introduced by the high efficiency of forward scattering. We conclude that most of the knots are in fact likely to lie in front of the plane of the sky, thus invalidating the Kervella et al. result. We also show that the flat equatorial disk structure determined by Feast is unlikely; instead, the morphology of the nebula is more probably bipolar, with a significant tilt of its axis with respect to the plane of the sky. Although the Kervella et al. distance result is invalidated, we show that high-resolution polarimetric imaging has the potential to yield a valid geometric distance to this important Cepheid.Comment: 10 pages, 5 figures, 1 table; accepted by Astronomy & Astrophysic

    Recent trends in the Illinois River indicated by fish populations: Havana, Ill.,

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    INHS Technical Report submitted as part of the Flowing Water Ecosystems Section in the Critical Trends Assessment Projec

    Battery workshop

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    The workshop was attended by representatives from industry and government. The requirements for energy storage and the plans for battery development were reviewed. The workshop followed a debate format, with the objective of recommending improvements to the development plans presented by NASA and the Air Force. The issues addressed were: (1) significant technology deficiencies which can be identified; (2) adequacy of current and proposed programs to resolve the technology deficiencies identified; (3) additional tasks which should be undertaken, including benefits and timing; and (4) lowest priority items in the presently planned program, both in content and in timing

    Extracorporeal membrane oxygenation with multiple-organ failure: Can molecular adsorbent recirculating system therapy improve survival?

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    BACKGROUND: Liver dialysis, molecular adsorbent recirculating system (MARS) particularly, has been used in liver failure to bridge to transplantation. We expanded the indication for MARS to patients with acute shock liver failure and cardiopulmonary failure on extracorporeal membrane oxygenation (ECMO), aiming to improve survival to wean from ECMO. METHODS: Retrospective chart analysis of patients on ECMO between 2010 and 2015 found 28 patients who met the criteria for acute liver failure, diagnosed by hyperbilirubinemia (total bilirubin ≥10 mg/dl) or by elevated transaminase (alanine transaminase \u3e1,000 IU/liter). Of these patients, 14 underwent MARS treatment (Group M), and 14 were supported with optimal medical treatment without MARS (Group C). Patient characteristics, liver function, and survival were compared between groups. RESULTS: Demographics, clinical risk factors, and pre-ECMO laboratory data were identical between the groups. MARS was used continuously for 8 days ± 9 in Group M. Total bilirubin, alanine transaminase, and international normalized ratio were improved significantly in Group M. There were no MARS-related complications. Survival to wean from ECMO for Group M was 64% (9/14) vs 21% (3/14) for Group C (p = 0.02). Mortality related to worsening liver dysfunction during ECMO was 40% (2/5 deaths) in Group M and 100% (11/11 deaths) in Group C (p = 0.004). The 30-day survival after ECMO was 43% (6/14) in Group M and 14% (2/14) in Group C (p = 0.09). CONCLUSIONS: MARS therapy in patients on ECMO safely accelerated recovery of liver function and improved survival to wean from ECMO, without increasing complications

    Of Education Interest

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