79 research outputs found

    HPCCP/CAS Workshop Proceedings 1998

    Get PDF
    This publication is a collection of extended abstracts of presentations given at the HPCCP/CAS (High Performance Computing and Communications Program/Computational Aerosciences Project) Workshop held on August 24-26, 1998, at NASA Ames Research Center, Moffett Field, California. The objective of the Workshop was to bring together the aerospace high performance computing community, consisting of airframe and propulsion companies, independent software vendors, university researchers, and government scientists and engineers. The Workshop was sponsored by the HPCCP Office at NASA Ames Research Center. The Workshop consisted of over 40 presentations, including an overview of NASA's High Performance Computing and Communications Program and the Computational Aerosciences Project; ten sessions of papers representative of the high performance computing research conducted within the Program by the aerospace industry, academia, NASA, and other government laboratories; two panel sessions; and a special presentation by Mr. James Bailey

    Transferring ecosystem simulation codes to supercomputers

    Get PDF
    Many ecosystem simulation computer codes have been developed in the last twenty-five years. This development took place initially on main-frame computers, then mini-computers, and more recently, on micro-computers and workstations. Supercomputing platforms (both parallel and distributed systems) have been largely unused, however, because of the perceived difficulty in accessing and using the machines. Also, significant differences in the system architectures of sequential, scalar computers and parallel and/or vector supercomputers must be considered. We have transferred a grassland simulation model (developed on a VAX) to a Cray Y-MP/C90. We describe porting the model to the Cray and the changes we made to exploit the parallelism in the application and improve code execution. The Cray executed the model 30 times faster than the VAX and 10 times faster than a Unix workstation. We achieved an additional speedup of 30 percent by using the compiler's vectoring and 'in-line' capabilities. The code runs at only about 5 percent of the Cray's peak speed because it ineffectively uses the vector and parallel processing capabilities of the Cray. We expect that by restructuring the code, it could execute an additional six to ten times faster

    Un aporte desde la educación musical a la interculturalidad dentro del aula: un estudio de caso en el sexto año básico de la Escuela Reyes Católicos

    Get PDF
    Tesis (Profesor de Educación Musical para la Educación Preescolar y Básica, Licenciado en Educación)La creciente migración de familias provenientes de Haití a Chile ha influido directamente en el aula, pues al momento de integrar a los niños (as) haitianos (as) al sistema educacional existe una gran barrera para el profesor que debe impartir clases a niños que desconocen el habla hispana. Ante esta situación, el docente se enfrenta con dificultades para abordar eficientemente los contenidos de la asignatura. El presente estudio tiene como objetivo contribuir a la interculturalidad de estudiantes haitianos (as) y de habla hispana que cursan sexto año básico, a través de un material pedagógico-metodológico musical, con el sentido de abordar la clase de educación musical desde una perspectiva que favorezca a la educación intercultural. El material elaborado tiene como propósito ayudar al profesor de música a generar una clase desde un enfoque intercultural, a partir de los planes y programas del Ministerio de Educación, a través de actividades y repertorio que potencien la participación de todos los estudiantes dentro del aula. El estudio se aplicó en el sexto básico de la Escuela Reyes Católicos, ubicado en la comuna de Santiago, debido a que este curso está conformado por estudiantes haitianos (as) y de habla hispana, que representan el grupo focal de la investigación. La investigación posee un diseño pre experimental y el tipo de investigación es exploratorio-descriptivo. El cual, también se sustenta en un paradigma constructivista. Los principales resultados de la aplicación del estudio demuestran que a través de las actividades realizadas se generó un espacio de interculturalidad entre los estudiantes haitianos y sus compañeros de diversas nacionalidades, esto se evidenció en los instrumentos de medición validados por expertos en educación musical de la Universidad Andrés Bello

    Structural Elucidation of Cisoid and Transoid Cyclization Pathways of a Sesquiterpene Synthase Using 2-Fluorofarnesyl Diphosphates

    Get PDF
    Sesquiterpene skeletal complexity in nature originates from the enzyme-catalyzed ionization of (trans,trans)-farnesyl diphosphate (FPP) (1a) and subsequent cyclization along either 2,3-transoid or 2,3-cisoid farnesyl cation pathways. Tobacco 5-epi-aristolochene synthase (TEAS), a transoid synthase, produces cisoid products as a component of its minor product spectrum. To investigate the cryptic cisoid cyclization pathway in TEAS, we employed (cis,trans)-FPP (1b) as an alternative substrate. Strikingly, TEAS was catalytically robust in the enzymatic conversion of (cis,trans)-FPP (1b) to exclusively (≥99.5%) cisoid products. Further, crystallographic characterization of wild-type TEAS and a catalytically promiscuous mutant (M4 TEAS) with 2-fluoro analogues of both all-trans FPP (1a) and (cis,trans)-FPP (1b) revealed binding modes consistent with preorganization of the farnesyl chain. These results provide a structural glimpse into both cisoid and transoid cyclization pathways efficiently templated by a single enzyme active site, consistent with the recently elucidated stereochemistry of the cisoid products. Further, computational studies using density functional theory calculations reveal concerted, highly asynchronous cyclization pathways leading to the major cisoid cyclization products. The implications of these discoveries for expanded sesquiterpene diversity in nature are discussed

    The tomato cis– prenyltransferase gene family

    Full text link
    Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/96709/1/tpj12063-sup-0004-FigureS4.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/96709/2/tpj12063-sup-0005-FigureS5.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/96709/3/tpj12063-sup-0002-FigureS2.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/96709/4/tpj12063-sup-0003-FigureS3.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/96709/5/tpj12063-sup-0001-FigureS1.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/96709/6/tpj12063.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/96709/7/tpj12063-sup-0006-TableS1.pd

    Efecto de la aplicación de distintas coberturas en palta Hass sobre su conservación en postcosecha

    No full text
    Memoria para optar al Título Profesional de Ingeniero Agrónomo. Mención FruticulturaNo disponible a texto completoEl presente estudio tuvo por objetivo evaluar polímeros naturales y sintéticos, como coberturas, en la calidad y vida postcosecha de paltas de la var. Hass, almacenadas a 6ºC. Las coberturas utilizadas fueron Quitosano (Q) 0,75%, Cloruro de Polivinilideno (PVDC) 3% + Alcohol Polivinílico (PVOH) 2% y Quitosano (Q) 1,5%, que se utilizaron como contraste a paltas sin aplicación de coberturas. Se utilizaron frutos recién cosechados con las siguientes características iniciales promedio: 9,32% de aceite, firmeza mayor a 13 kg-f, peso de 286,3 g, y color medido en los parámetros L* 36,88, C* 18,97, hº 124,84, a* -10,77 y b* 15,6. Los parámetros evaluados fueron: color, resistencia de la pulpa a la presión, deshidratación y parámetros sensoriales. Además se midió dos veces por semana la emisión de CO2 y etileno para determinar la tasa respiratoria y la producción de etileno. Los análisis realizados mostraron un efecto positivo en las paltas tratadas con las coberturas Cloruro de Polivinilideno (PVDC) 3% + Alcohol Polivinílico (PVOH) 2% y Quitosano (Q) 1,5% en los parámetros de color L* y a*. Respecto al parámetro sensorial de apariencia, se obtuvo una menor calificación con la cobertura Quitosano (Q) 0,75% y se mantuvo esa tendencia en el resto de los parámetros sensoriales para esa cobertura. Para el resto de los parámetros evaluados no se observaron efectos, aunque sí se observó una tendencia a la menor deshidratación en el tiempo en las paltas tratadas con coberturas respecto a las no tratadas. En consecuencia, los análisis realizados demuestran que la aplicación de las coberturas bajo las condiciones señaladas en este ensayo representan un reducido efecto en la conservación de la calidad de paltas var. Hass.The objective of this study was to evaluate polymers coatings, in order to get a more extended conservation of the postharvest quality of “Hass” variety avocado, stored at 6ºC. The results showed a slow evolution in the color change of the fruit’s epidermis for the parameters L* and a* under some coatings used. The sensorial appearance parameter got smaller qualifications for one of the used coatings, which doesn’t represent a favorable effect. The other evaluated parameters did not show improvement, however, it observed a tendency to a lower dehydration in the avocados treated with coatings. Consequently, the application of the coatings under the conditions of this study represents a small improvement in the conservation of the quality to “Hass” variety avocado

    Welcome to the NASA High Performance Computing and Communications Computational Aerosciences (CAS) Workshop 2000

    No full text
    The purpose of the CAS workshop is to bring together NASA's scientists and engineers and their counterparts in industry, other government agencies, and academia working in the Computational Aerosciences and related fields. This workshop is part of the technology transfer plan of the NASA High Performance Computing and Communications (HPCC) Program. Specific objectives of the CAS workshop are to: (1) communicate the goals and objectives of HPCC and CAS, (2) promote and disseminate CAS technology within the appropriate technical communities, including NASA, industry, academia, and other government labs, (3) help promote synergy among CAS and other HPCC scientists, and (4) permit feedback from peer researchers on issues facing High Performance Computing in general and the CAS project in particular. This year we had a number of exciting presentations in the traditional aeronautics, aerospace sciences, and high-end computing areas and in the less familiar (to many of us affiliated with CAS) earth science, space science, and revolutionary computing areas. Presentations of more than 40 high quality papers were organized into ten sessions and presented over the three-day workshop. The proceedings are organized here for easy access: by author, title and topic

    Resistant cultivars, fungicides combat downy mildew of spinach

    No full text
    The recent outbreak of spinach downy mildew, caused by a new race of the pathogen, left California growers without resistant cultivars and with few chemical controls. However, two fungicides have proved effective against the pathogen and two new resistant cultivars are now commercially available on a limited basis

    Improving irrigation systems conserves water in greenhouse-grown cut flowers

    No full text
    In our evaluation of three microirrigation systems used in greenhouse cut-flower production, the systems' ability to apply water uniformly varied widely. The most common irrigation system, the perimeter system, generally applied water less consistently than other tested systems. Center riser and drip irrigation systems generally applied water more uniformly than the perimeter system. And while many perimeter irrigation systems could be retrofitted to improve water distribution, all irrigation systems could be improved with a regular maintenance program consisting of flushing rust and other particulates from irrigation pipe, and chemically controlling biological growth in irrigation pipe
    corecore