324 research outputs found

    Mosquito Larvicides from Cyanobacteria

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    Cyanobacteria (blue-green algae) produce a diverse array of toxic or otherwise bioactive metabolites. These allelochemicals may also play a role in defense against potential predators and grazers, particularly aquatic invertebrates and their larvae, including mosquitoes. Compounds derived from cyanobacteria collected from the Florida Everglades and other Florida waterways were investigated as insecticides against the mosquito Aedes aegypti, a vector of dengue and yellow fever. Screening of cyanobacterial biomass revealed several strains that exhibited mosquito larvicidal activity. Guided via bioassay guided fractionation, a non-polar compound from Leptolyngbya sp. 21-9-3 was found to be the most active component. Characterization revealed the prospective compound to be a monounsaturated fatty acid with the molecular formula C16H30O2. This is the first evidence of mosquito larvicidal activity for this particular fatty acid. With larvicidal becoming more prevalent, fatty acids should be explored for future mosquito control strategies

    Overview of Boundary Layer Transition Research in Support of Orbiter Return To Flight

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    A predictive tool for estimating the onset of boundary layer transition resulting from damage to and/or repair of the thermal protection system was developed in support of Shuttle Return to Flight. The boundary layer transition tool is part of a suite of tools that analyze the aerothermodynamic environment to the local thermal protection system to allow informed disposition of damage for making recommendations to fly as is or to repair. Using mission specific trajectory information and details of each damage site or repair, the expected time (and thus Mach number) at transition onset is predicted to help define the aerothermodynamic environment to use in the subsequent thermal and stress analysis of the local thermal protection system and structure. The boundary layer transition criteria utilized for the tool was developed from ground-based measurements to account for the effect of both protuberances and cavities and has been calibrated against select flight data. Computed local boundary layer edge conditions were used to correlate the results, specifically the momentum thickness Reynolds number over the edge Mach number and the boundary layer thickness. For the initial Return to Flight mission, STS-114, empirical curve coefficients of 27, 100, and 900 were selected to predict transition onset for protuberances based on height, and cavities based on depth and length, respectively

    Perspectives in quality: designing the WHO Surgical Safety Checklist

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    The World Health Organization's Patient Safety Programme created an initiative to improve the safety of surgery around the world. In order to accomplish this goal the programme team developed a checklist with items that could and, if at all possible, should be practised in all settings where surgery takes place. There is little guidance in the literature regarding methods for creating a medical checklist. The airline industry, however, has more than 70 years of experience in developing and using checklists. The authors of the WHO Surgical Safety Checklist drew lessons from the aviation experience to create a safety tool that supports essential clinical practice. In order to inform the methodology for development of future checklists in health care, we review how we applied lessons learned from the aviation experience in checklist development to the development of the Surgical Safety Checklist and also discuss the differences that exist between aviation and medicine that impact the use of checklists in health car

    Review of Orbiter Flight Boundary Layer Transition Data

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    In support of the Shuttle Return to Flight program, a tool was developed to predict when boundary layer transition would occur on the lower surface of the orbiter during reentry due to the presence of protuberances and cavities in the thermal protection system. This predictive tool was developed based on extensive wind tunnel tests conducted after the loss of the Space Shuttle Columbia. Recognizing that wind tunnels cannot simulate the exact conditions an orbiter encounters as it re-enters the atmosphere, a preliminary attempt was made to use the documented flight related damage and the orbiter transition times, as deduced from flight instrumentation, to calibrate the predictive tool. After flight STS-114, the Boundary Layer Transition Team decided that a more in-depth analysis of the historical flight data was needed to better determine the root causes of the occasional early transition times of some of the past shuttle flights. In this paper we discuss our methodology for the analysis, the various sources of shuttle damage information, the analysis of the flight thermocouple data, and how the results compare to the Boundary Layer Transition prediction tool designed for Return to Flight

    Helicity, polarization, and Riemann-Silberstein vortices

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    Riemann-Silberstein (RS) vortices have been defined as surfaces in spacetime where the complex form of a free electromagnetic field given by F=E+iB is null (F.F=0), and they can indeed be interpreted as the collective history swept out by moving vortex lines of the field. Formally, the nullity condition is similar to the definition of "C-lines" associated with a monochromatic electric or magnetic field, which are curves in space where the polarization ellipses degenerate to circles. However, it was noted that RS vortices of monochromatic fields generally oscillate at optical frequencies and are therefore unobservable while electric and magnetic C-lines are steady. Here I show that under the additional assumption of having definite helicity, RS vortices are not only steady but they coincide with both sets of C-lines, electric and magnetic. The two concepts therefore become one for waves of definite frequency and helicity. Since the definition of RS vortices is relativistically invariant while that of C-lines is not, it may be useful to regard the vortices as a wideband generalization of C-lines for waves of definite helicity.Comment: 5 pages, no figures. Submitted to J of Optics A, special issue on Singular Optics; minor changes from v.

    Metachromatic Leukodystrophy: A Case of Triplets With the Late Infantile Variant and a Systematic Review of the Literature

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    Metachromatic Leukodystrophy is a rare disorder with great clinical variability. We report the first case of triplets with the late infantile form of the disease and their systematic progression of symptoms. We reviewed the literature and identified all human studies that reported new cases since 1921. We analyzed survival by decade to assess the impact of historical changes in management of care. Mean age at death and 5-year survival from onset of symptoms for late infantile, juvenile and adult phenotype were 4.2 years and 24.9%, 17.4 years and 70.3%, and 43.1 years and 88.6% respectively. 5-year survival of cases reported after 1990 was significantly better than cases reported before 1970 in all subtypes of metachromatic leukodystrophy (late infantile: 52% vs. 14%, juvenile: 100% vs. 46%, adult: 95% vs. 67%). Survival in the late infantile subtype was worse than in other subtypes. Survival significantly improved over time in all subtypes

    1972 Research Progress Reports, Fruit and Vegetable Processing and Food Technology

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    Evaluation of tomato cultivars / W. A. Gould, James Black, Louise Howiler, Shirley Perryman, and Stanley Z. Berry -- Effects of food additives on the quality of canned tomatoes / Wilbur A. Gould, John Mount, Jacquelyn Gould, Louise Howiler, and James Black -- Effect of storage temperature on shelf life of ascorbic acid fortified tomato juice / Gerald A. Pope and Wilbur A. Gould -- Survey of waste disposal practices of Ohio tomato processors / J. R. Geisman -- Evaluation of snap bean varieties for processing / Wilbur A. Gould, Jacquelyn Gould and Roberta Topits -- The effect of variety, size, and fermentation temperature on the quality attributes of cucumber pickles / Gary Flinn and Wilbur A. Gould -- Progress report on frozen corn-on-the-cob / James W. Swinehart and Wilbur A. Gould -- Progress report on cabbage lipids / Andrew C. Peng -- Effect of soybean flour on quality and protein content in the manufacture of doughnuts / Mohamed I. Mahmoud and Wilbur A. Goul

    1973 Research Progress Reports, Fruit and Vegetable Processing and Food Technology

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    Evaluation of snap bean varieties for processing / Wilbur A. Gould -- Evaluation of tomato cultivars for processing / W. A. Gould, James Black, Emily Korensky, Ruth Stillabower, and Stanley Z. Berry -- Commercial tomato cultivar evaluation / Wilbur A. Gould, Jerry Wright, in cooperation with Stanley Berry, Marion White, Tip Top Canning Co., Beckman and Gast Company and Hirzel Canning Co. -- Relationship of USDA D6 tomato colorimeter to AGTRON E-5 / Wilbur A. Gould and Jerry Wright -- Effects of food additives on the quality of canned tomatoes / Wilbur A. Gould, Jacquelyn Gould, and James Black -- Effects of food additives on the quality of canned tomato juice / Wilbur A. Gould, Ruth Stillabower, Jacquelyn Gould and James Black -- Retention of ascorbic acid in fortified tomato juice ; Effect of storage time and temperature and added ascorbic acid on the total acid and pH of tomato juice / Gerald G. Pope and Wilbur A. Gould -- Cell wall components and tomato juice consistency / David E. Crean -- Lipid content of cabbage & sauerkraut / Andrew C. Peng -- Canned rice-tomatoes / Teung Chin and Wilbur A. Gould -- Development of a canned pecan pie filling / W. A. Gould and S. Perryman -- A new soybean food from tempeh / Nasruddin Iljas, Wilbur A. Gould and Andrew C. Peng -- Rehabilitation and recycling spend cucumber pickling brines / J. R. Geisman and R. E. Henne -- Evaluation of several grape cultivars for wine making / James F. Gallande

    The state of the Martian climate

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    60°N was +2.0°C, relative to the 1981–2010 average value (Fig. 5.1). This marks a new high for the record. The average annual surface air temperature (SAT) anomaly for 2016 for land stations north of starting in 1900, and is a significant increase over the previous highest value of +1.2°C, which was observed in 2007, 2011, and 2015. Average global annual temperatures also showed record values in 2015 and 2016. Currently, the Arctic is warming at more than twice the rate of lower latitudes
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