27 research outputs found

    Automating Robot Programming In The Cleaning And Deburring Workstation Of The Amrf

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    In the Cleaning and Deburring Workstation, two robots cooperate to accomplish deburring, buffing, cleaning, and handling of machined metal parts. A technique has been developed which uses part geometry data to generate robot paths automatically. Using a graphics interface, an operator specifies how a part is to be gripped, fixtured, deburred, buffed, and cleaned. A path planner combines this process plan with geometry data to compute robot paths. A workstation controller coordinates the actions of both robots, allowing various steps in the finishing process to be performed simultaneously. This paper describes the methods used to automate the finishing process. INTRODUCTION The Automated Manufacturing Research Facility (AMRF) of the National Institute of Standards and Technology (formerly NBS) is a research testbed consisting of three machining workstations, an inspection workstation, a distributed material handling workstation, and a cleaning and deburring workstation [1]. Initiated i..

    Evaluation of habitat use by adult plaice (Pleuronectes platessa L.) using underwater video survey techniques

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    Large-scale spatial surveys of fish species in relation to habitat have tended to focus on depth, sediment type and temperature as descriptors of fish habitats. At a smaller scale, habitat parameters such as the relief of the sea floor, the presence of structuring fauna and prey availability may have a large influence on fish distribution, but often are not considered. In the present study we used video survey techniques to study habitat components in areas of the English Channel that were known to support consistently high densities of adult plaice. Habitat features were quantified and related to the density of adult plaice caught within the same study areas. To focus the study on habitat components other than sediment type all sites chosen had sandy substrata. The scale and spatial distribution and heterogeneity of physical and biological structures were quantified for each site and correlated to plaice densities. Plaice densities correlated with the abundance of benthic fauna recorded. In particular the emergent tube-dwelling polychaetes Lanice conchilega and Cheatopterus spp., that are a valuable food source for plaice dominated some sites. Abiotic habitat features and habitat heterogeneity showed no clear relationships with respect to plaice densities at the scale of our surveys. This indicated that prey availability might be the driving force for habitat selection of adult plaice within sandy habitats and that other habitat descriptors assume lesser importance at smaller spatial scales

    Development of a <i>Streptococcus pneumoniae </i>Keratitis Model in Mice

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    BACKGROUND: Streptococcus pneumoniae is a common cause of bacterial keratitis, and models to examine the ocular pathogenesis of this bacterium would aid in efforts to treat pneumococcal keratitis. The aim of this study was to establish a murine model of pneumococcal keratitis. METHODS: The corneas of A/J, BALB/c or C57BL/6 mice were scratched and topically infected with a clinical strain of S. pneumoniae. Slitlamp examination (SLE), enumeration of bacteria in the corneas and histology were performed. RESULTS: Bacteria were recovered from the eyes of A/J mice on postinfection (PI) days 1 [1.96 ± 0.61 log(10) colony-forming units (CFU)] and 3 (1.41 ± 0.71 log(10) CFU). SLE scores were significantly higher in the infected A/J mice as compared to the BALB/c or C57BL/6 mice on PI day 3 (p < 0.0001) and steadily increased over time, reaching a maximal value of 3.00 ± 0.35 on PI day 10. Histopathology revealed stromal edema and the influx of polymorphonuclear leukocytes on PI days 7 and 10, and corneal disruption on PI day 7. CONCLUSIONS: S. pneumoniae keratitis was established in A/J mice, but not BALB/c or C57BL/6 mice

    Substituted 2-phenylimidazopyridines : a new class of drug leads for human African trypanosomiasis

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    A phenotypic screen of a compound library for antiparasitic activity on Trypanosoma brucei, the causative agent of human African trypanosomiasis, led to the identification of substituted 2-(3-aminophenyl)oxazolopyridines as a starting point for hit-to-lead medicinal chemistry. A total of 110 analogues were prepared, which led to the identification of 64, a substituted 2-(3-aminophenyl)imidazopyridine. This compound showed antiparasitic activity in vitro with an EC50 of 2 nM and displayed reasonable druglike properties when tested in a number of in vitro assays. The compound was orally bioavailable and displayed good plasma and brain exposure in mice. Compound 64 cured mice infected with Trypanosoma brucei when dosed orally down to 2.5 mg/kg. Given its potent antiparasitic properties and its ease of synthesis, compound 64 represents a new lead for the development of drugs to treat human African trypanosomiasis
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