790 research outputs found

    The dynamism of salt crust patterns on playas

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    Playas are common in arid environments and can be major sources of mineral dust that can influence global climate. These landforms typically form crusts that limit evaporation and dust emission, modify surface erosivity and erodibility, and can lead to over prediction or under prediction of (1) dust-emission potential and (2) water and heat fluxes in energy balance modeling. Through terrestrial laser scanning measurements of part of the Makgadikgadi Pans of Botswana (a Southern Hemisphere playa that emits significant amounts of dust), we show that over weeks, months, and a year, the shapes of these surfaces change considerably (ridge thrusting of >30 mm/week) and can switch among continuous, ridged, and degraded patterns. Ridged pattern development changes the measured aerodynamic roughness of the surface (as much as 3 mm/week). The dynamic nature of these crusted surfaces must be accounted for in dust entrainment and moisture balance formulae to improve regional and global climate models

    Recipients of electric-powered indoor/outdoor wheelchairs provided by a National Health Service: A cross-sectional study

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    This is the post-print version of the final paper published in Archives of Physical Medicine and Rehabilitation. The published article is available from the link below. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. Copyright @ 2013 by the American Congress of Rehabilitation Medicine.OBJECTIVE: To describe the characteristics, across all ages, of powered wheelchair users and the assistive technology prescribed by a regional specialist wheelchair service DESIGN: Cross-sectional study SETTING: Regional wheelchair service provided to those fulfilling strict eligibility criteria by a National Health Service serving a population of 3 million. PARTICIPANTS: 544 Electric Powered Indoor/outdoor wheelchair (EPIOC) users. INTERVENTIONS: Not applicable MAIN OUTCOME MEASURES: Demographic, clinical/diagnostic details of EPIOC recipients including pain, (kypho)scoliosis and ventilators. Technical features including specialised (adaptive) seating (SS), tilt in space (TIS), and modified control systems. Factors were related to age groups: 1 (0-15), 2 (16-24), 3 (25-54), 4 (55-74) and 5 (75+). RESULTS: 262 men mean age 41.7 (range 8-82, sd 20.7) and 282 women mean age 47.2 (range 7-92, sd 19.7) years were studied. Neurological/neuromuscular conditions predominated (81%) with cerebral palsy (CP) (18.9%) and multiple sclerosis (16.4%). Conditions presenting at birth or during childhood constituted 39%. 99 had problematic pain, 83 a (kypho)scoliosis and 11 used ventilators. SS was provided to 169 users (31%), the majority had CP or muscular dystrophy. TIS was used by 258 (53%). Younger people were more likely to receive TIS than older ones. Only 92 had SS and TIS, mean age 29 (range 8-72, sd 17.8) years. 52 used modified control systems. CONCLUSIONS: The diversity of EPIOC users across age and diagnostic groups is shown. Their complex interrelationships with these technical features of EPIOC prescription are explored. Younger users were more complex due to age-related changes. This study provides outcomes of the EPIOC prescription for this heterogeneous group of very severely disabled people

    Intravital multiphoton microscopy can model uptake and excretion of fluorescein in hepatic ischemia-reperfusion injury

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    The liver is important in the biotransformation of various drugs, where hepatic transporters facilitate uptake and excretion. Ischemia-reperfusion (I/R) injury is a common occurrence in liver surgery, and the developing oxidative stress can lead to graft failure. We used intravital multiphoton tomography, with fluorescence lifetime imaging, to characterize metabolic damage associated with hepatic I/R injury and to model the distribution of fluorescein as a measure of liver function. In addition to measuring a significant increase in serum alanine transaminase levels, characteristic of hepatic I/R injury, a decrease in the averaged weighted lifetime of reduced nicotinamide adenine dinucleotide phosphate was observed, which can be attributed to a changed metabolic redox state of the hepatocytes. I/R injury was associated with delayed uptake and excretion of fluorescein and elevated area-under-the-curve within the hepatocytes compared to sham (i.e., untreated control) as visualized and modeled using images recorded by intravital multiphoton tomography. High-performance liquid chromatography analysis showed no differences in plasma or bile concentrations of fluorescein. Finally, altered fluorescein distribution was associated with acute changes in the expression of liver transport proteins. In summary, multiphoton intravital imaging is an effective approach to measure liver function and is more sensitive in contrasting the impact of I/R injury than measuring plasma and bile concentrations of fluorescein

    Mejoramiento de los procesos de fermentación para la elaboración de chocolate del Centro Agrícola del Cantón Quevedo

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    Cocoa is one of the most important global commodities, providing economic support to small and medium-sized farmers. The present research project aims to study the improvement of fermentation processes for the production of chocolate by the members of the Agricultural Center of Cantonal de Quevedo. The issue at hand is that the current cocoa bean fermentation and post-harvest methods significantly affect the physical and sensory quality of the beans. Inadequate cocoa fermentation adversely impacts the sensory quality of the beans by failing to effectively eliminate mucilage and causing chemical changes. A Completely Randomized Two-Factor Design was applied, with the first factor being "Cocoa Types" and the second factor being "Fermentation Methods." This design included 6 treatments with 3 replications, resulting in a total of 18 study objects. Morphological evaluation of the cocoa fruit and physicochemical evaluation of cocoa beans (temperature, pH, °Brix) were conducted. The fermentation incidence was also assessed through the cut test. The initial variables did not show any statistical differences. However, the best treatment was found to be National cocoa fermented in Rohan-type micro-fermentation boxes, which also showed a higher quantity of fermented beans in National and Trinitario cocoa varieties, in accordance with INEN 176 standards.El cacao es una de las materias primas más importantes a nivel mundial, siendo el soporte económico de pequeños y medianos agricultores, el presenté trabajo de investigación tiene como objetivo el estudio el mejoramiento de los procesos de fermentación para la elaboración de chocolate de los socios del Centro Agrícola del Cantonal de Quevedo. Lo cual la incidencia de esta problemática que en la actualidad el método de fermentación y postcosecha de las almendras de cacao es un factor importante porque da origen a la calidad física y sensorial de la almendra, buscando la eliminación de mucilago y cambios químicos del cacao, al no tener una fermentación de cacao perjudica a la calidad sensorial de las almendras, se aplicó un Diseño Completamente al Azar bifactorial como primer factor (Tipos de cacao) y segundo factor (métodos de fermentación), conformado por 6  tratamientos y 3 repeticiones un total de 18 objetos de estudio, se procedió a realizar evaluación morfológica del fruto y evaluación fisicoquímicas de los granos de cacao (Temperatura, pH, °Brix) y a su vez la incidencia en la fermentación en la prueba de corte, dando como resultado en las variables iniciales no presentó diferencia estadística, no obstante el mejor tratamiento fue el cacao Nacional fermentado en cajas micro fermentadoras tipo Rohan, el mismo comportamiento tuvo en la prueba de corte evidenciándose mayor cantidad de granos fermentados en cacao Nacional y Trinitario, según la normativa INEN 176

    Creameries for Texas

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    28 p

    1977: Abilene Christian College Bible Lectures - Full Text

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    Seeking The Lost Being the Abilene Christian University Annual Bible Lectures 1977 Published by ABILENE CHRISTIAN UNIVERSITY Book Store ACU Station Abilene, Texas 7960

    Origin of Homochirality in Biosystems

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    Experimental data for a series of central and simple molecules in biosystems show that some amino acids and a simple sugar molecule have a chiral discrimination in favor of homochirality. Models for segregation of racemic mixtures of chiral amphiphiles and lipophiles in aqueous solutions show that the amphiphiles with an active isomerization kinetics can perform a spontaneous break of symmetry during the segregation and self-assembly to homochiral matter. Based on this observation it is argued that biomolecules with a sufficiently strong chiral discrimination could be the origin of homochirality in biological systems

    Candidate Isolated Neutron Stars and Other Optically Blank X-ray Fields Identified from the ROSAT All-Sky and Sloan Digital Sky Surveys

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    Only seven radio-quiet isolated neutron stars (INSs) emitting thermal X rays are known, a sample that has yet to definitively address such fundamental issues as the equation of state of degenerate neutron matter. We describe a selection algorithm based on a cross-correlation of the ROSAT All-Sky Survey (RASS) and the Sloan Digital Sky Survey (SDSS) that identifies X-ray error circles devoid of plausible optical counterparts to the SDSS g~22 magnitudes limit. We quantitatively characterize these error circles as optically blank; they may host INSs or other similarly exotic X-ray sources such as radio-quiet BL Lacs, obscured AGN, etc. Our search is an order of magnitude more selective than previous searches for optically blank RASS error circles, and excludes the 99.9% of error circles that contain more common X-ray-emitting subclasses. We find 11 candidates, nine of which are new. While our search is designed to find the best INS candidates and not to produce a complete list of INSs in the RASS, it is reassuring that our number of candidates is consistent with predictions from INS population models. Further X-ray observations will obtain pinpoint positions and determine whether these sources are entirely optically blank at g~22, supporting the presence of likely isolated neutron stars and perhaps enabling detailed follow-up studies of neutron star physics.Comment: Accepted for publication in the AJ; higher resolution figures available at http://www.astro.washington.edu/agueros/pub
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