287 research outputs found

    The Navy's Analog Scheme for Forecasting Tropical Cyclone Motion over the Northeastern Pacific Ocean

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    The Navy's EPANALOG (Northeastern Pacific Analog Tropical Cyclone Tracker) forecast program is introduced. EPANALOG selects analog tropical cyclones from a 25-year Northeastern Pacific Ocean history. The selected analog tracks, statistically adjusted for position, vector motion, and date differences between them and the recent history of the tropical cyclone being forecasted, and composited into a single forecast track. Verification of EPANALOG forecasts to 96 hours are shown for randomly selected historical tropical cyclones as initiated from best-track positions statistically adjusted to simulate position inaccuracies, as well as for forecasts general from 1973 operational tropical cyclone positions. The latter are intercompared with a homogeneous set of objective persistence an MOHATT forecasts as well as subjective official forecasts for the 24-, 48- and 72-hour intervals. The accuracy of the 1973 EPANALOG is shown to generally exceed that of the existent techniques for all forecast intervals tested.Naval Air Systems Command, Navy Departmenthttp://archive.org/details/navysanalogschem62jar

    Secondhand Goods, Firsthand Knowledge: An Organizational Structure Exercise At The Local Flea Market

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    We developed a unique and enjoyable field trip exercise to challenge students to identify various organizational structures and their properties and dimensions present in the local flea market. Drawing on students’ review of common organizational structures, i.e., simple, functional, multi-divisional, and network, this exercise requires that individuals or small groups of students visit a local flea market to observe and analyze the numerous organizational structures apparent. Students then use a given report format to identify: the properties of organizations; distinct organizational structures on varying levels of analysis (the market as a whole, areas of specialization, and vendors); and the dimensions seen in organizations (specialization, span of control, formalization, and centralization). In-class discussion of the topic, using discussion questions provided, further clarifies the concepts that students viewed in practice at the flea market

    Growth Route Toward III-V Multispectral Solar Cells on Silicon

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    To date, high efficiency multijunction solar cells have been developed on Ge or GaAs substrates for space applications, and terrestrial applications are hampered by high fabrication costs. In order to reduce this cost, we propose a breakthrough technique of III-V compound heteroepitaxy on Si substrates without generation of defects critical to PV applications. With this technique we expect to achieve perfect integration of heterogeneous Ga1-xInxAs micro-crystals on Si substrates. In this paper, we show that this is the case for x=0. GaAs crystals were grown by Epitaxial Lateral Overgrowth on Si (100) wafers covered with a thin SiO2 nanostructured layer. The cristallographic structure of these crystals is analysed by MEB and TEM imaging. Micro-Raman and Micro-Photomuminescence spectra of GaAs crystals grown with different conditions are compared with those of a reference GaAs wafer in order to have more insight on eventual local strains and their cristallinity. This work aims at developping building blocks to further develop a GaAs/Si tandem demonstrator with a potential conversion efficiency of 29.6% under AM1.5G spectrum without concentration, as inferred from our realistic modeling. This paper shows that Epitaxial Lateral Overgrowth has a very interesting potential to develop multijunction solar cells on silicon approaching the today 30.3% world record of a GaInP/GaAs tandem cell under the same illumination conditions, but on a costlier substrate than silicon.Comment: Preprint of the 28th EUPVSEC proceedings, September 2013, Paris, France. (5 pages

    Genomic conservation of cattle microsatellite loci in wild gaur (Bos gaurus) and current genetic status of this species in Vietnam

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    <p>Abstract</p> <p>Background</p> <p>The wild gaur (<it>Bos gaurus</it>) is an endangered wild cattle species. In Vietnam, the total number of wild gaurs is estimated at a maximum of 500 individuals. Inbreeding and genetic drift are current relevant threats to this small population size. Therefore, information about the genetic status of the Vietnamese wild gaur population is essential to develop strategies for conservation and effective long-term management for this species. In the present study, we performed cross-species amplification of 130 bovine microsatellite markers, in order to evaluate the applicability and conservation of cattle microsatellite loci in the wild gaur genome. The genetic diversity of Vietnamese wild gaur was also investigated, based on data collected from the 117 successfully amplified loci.</p> <p>Results</p> <p>One hundred-thirty cattle microsatellite markers were tested on a panel of 11 animals. Efficient amplifications were observed for 117 markers (90%) with a total of 264 alleles, and of these, 68 (58.1%) gave polymorphic band patterns. The number of alleles per locus among the polymorphic markers ranged from two to six. Thirteen loci (<it>BM1314</it>, <it>BM2304</it>, <it>BM6017</it>, <it>BMC2228</it>, <it>BMS332</it>, <it>BMS911</it>, <it>CSSM023</it>, <it>ETH123</it>, <it>HAUT14</it>, <it>HEL11</it>, <it>HEL5</it>, <it>ILSTS005 </it>and <it>INRA189</it>) distributed on nine different cattle chromosomes failed to amplify wild gaur genomic DNA. Three cattle Y-chromosome specific microsatellite markers (<it>INRA124</it>, <it>INRA126 </it>and <it>BM861</it>) were also highly specific in wild gaur, only displaying an amplification product in the males. Genotype data collected from the 117 successfully amplified microsatellites were used to assess the genetic diversity of this species in Vietnam. Polymorphic Information Content (PIC) values varied between 0.083 and 0.767 with a mean of 0.252 while observed heterozygosities (<it>H</it><sub><it>o</it></sub>) ranged from 0.091 to 0.909 (mean of 0.269). Nei's unbiased mean heterozygosity and the mean allele number across loci were 0.298 and 2.2, respectively.</p> <p>Conclusion</p> <p>Extensive conservation of cattle microsatellite loci in the wild gaur genome, as shown by our results, indicated a high applicability of bovine microsatellites for genetic characterization and population genetic studies of this species. Moreover, the low genetic diversity observed in Vietnamese wild gaur further underlines the necessity of specific strategies and appropriate management plans to preserve this endangered species from extinction.</p

    CaveUDK: a VR game engine middleware

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    Previous attempts at developing immersive versions of game engines have faced difficulties in achieving both overall high performance and preserving reusability of software developments. In this paper, we present a high-level VR middleware based on one of the most successful commercial game engines: the UnrealÂź Engine 3.0 (UE3). We describe a VR framework implemented as an extension to the UnrealÂź Development Kit (UDK) supporting CAVE"-like installations. Our approach relies on a distributed architecture reinforced by specific replication patterns to synchronize the user's point of view and interactions within a multi-screen installation. Our performance benchmarks indicated that our immersive port does not affect the game engine performance, even with complex real-time applications, such as fast-paced multiplayer First Person Shooter (FPS) games or high-resolution graphical environments with 2M+ polygons. A user study also demonstrated the capacity of our VR middleware to elicit high spatial presence while maintaining low cybersickness effects. With free distribution, we believe such a platform can support future Entertainment and VR research

    The Minimal Supersymmetric Standard Model: Group Summary Report

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    CONTENTS: 1. Synopsis, 2. The MSSM Spectrum, 3. The Physical Parameters, 4. Higgs Boson Production and Decays, 5. SUSY Particle Production and Decays, 6. Experimental Bounds on SUSY Particle Masses, 7. References.Comment: 121 pages, latex + epsfig, graphicx, axodraw, Report of the MSSM working group for the Workshop "GDR-Supersym\'etrie",France. Rep. PM/98-4

    Pharmacokinetic/pharmacodynamic modelling approaches in paediatric infectious diseases and immunology.

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    Pharmacokinetic/pharmacodynamic (PKPD) modelling is used to describe and quantify dose-concentration-effect relationships. Within paediatric studies in infectious diseases and immunology these methods are often applied to developing guidance on appropriate dosing. In this paper, an introduction to the field of PKPD modelling is given, followed by a review of the PKPD studies that have been undertaken in paediatric infectious diseases and immunology. The main focus is on identifying the methodological approaches used to define the PKPD relationship in these studies. The major findings were that most studies of infectious diseases have developed a PK model and then used simulations to define a dose recommendation based on a pre-defined PD target, which may have been defined in adults or in vitro. For immunological studies much of the modelling has focused on either PK or PD, and since multiple drugs are usually used, delineating the relative contributions of each is challenging. The use of dynamical modelling of in vitro antibacterial studies, and paediatric HIV mechanistic PD models linked with the PK of all drugs, are emerging methods that should enhance PKPD-based recommendations in the future

    Systems medicine and integrated care to combat chronic noncommunicable diseases

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    We propose an innovative, integrated, cost-effective health system to combat major non-communicable diseases (NCDs), including cardiovascular, chronic respiratory, metabolic, rheumatologic and neurologic disorders and cancers, which together are the predominant health problem of the 21st century. This proposed holistic strategy involves comprehensive patient-centered integrated care and multi-scale, multi-modal and multi-level systems approaches to tackle NCDs as a common group of diseases. Rather than studying each disease individually, it will take into account their intertwined gene-environment, socio-economic interactions and co-morbidities that lead to individual-specific complex phenotypes. It will implement a road map for predictive, preventive, personalized and participatory (P4) medicine based on a robust and extensive knowledge management infrastructure that contains individual patient information. It will be supported by strategic partnerships involving all stakeholders, including general practitioners associated with patient-centered care. This systems medicine strategy, which will take a holistic approach to disease, is designed to allow the results to be used globally, taking into account the needs and specificities of local economies and health systems
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