31,935 research outputs found

    Multiple categories: the equivalence of a globular and a cubical approach

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    We show the equivalence of two kinds of strict multiple category, namely the well known globular omega-categories, and the cubical omega-categories with connections.Comment: Latex2E, xy, 38 pages. New version 17 Dec 2001, as accepted by Advances in Mathematics: minor but useful corrections. Some pictures adde

    Evolution of a stream ecosystem in recently deglaciated terrain

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    Climate change and associated glacial recession create new stream habitat that leads to the assembly of new riverine communities through primary succession. However, there are still very few studies of the patterns and processes of community assembly during primary succession for stream ecosystems. We illustrate the rapidity with which biotic communities can colonize and establish in recently formed streams by examining Stonefly Creek in Glacier Bay, Alaska (USA), which began to emerge from a remnant glacial ice mass between 1976 and 1979. By 2002, 57 macroinvertebrate and 27 microcrustacea species had become established. Within 10 years of the stream's formation, pink salmon and Dolly Varden charr colonized, followed by other fish species, including juvenile red and silver salmon, Coast Range sculpin, and sticklebacks. Stable-isotope analyses indicate that marine-derived nitrogen from the decay of salmon carcasses was substantially assimilated within the aquatic food web by 2004. The findings from Stonefly Creek are compared with those from a long-term study of a similarly formed but older stream (12 km to the northeast) to examine possible similarities in macroinvertebrate community and biological trait composition between streams at similar stages of development. Macroinvertebrate community assembly appears to have been initially strongly deterministic owing to low water temperature associated with remnant ice masses. In contrast, microcrustacean community assembly appears to have been more stochastic. However, as stream age and water temperature increased, macroinvertebrate colonization was also more stochastic, and taxonomic similarity between Stonefly Creek and a stream at the same stage of development was,<50%. However the most abundant taxa were similar, and functional diversity of the two communities was almost identical. Tolerance is suggested as the major mechanism of community assembly. The rapidity with which salmonids and invertebrate communities have become established across an entire watershed has implications for the conservation of biodiversity in freshwater habitats

    Yo San : Japanese Intermezzo Two-Step

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    https://digitalcommons.library.umaine.edu/mmb-ps/1728/thumbnail.jp

    A novel approach for quality control system using sensor fusion of infrared and visual image processing for laser sealing of food containers

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    This paper presents a new mechatronic approach of using infrared thermography combined with image processing for the quality control of a laser sealing process for food containers. The suggested approach uses an on-line infrared system to assess the heat distribution within the container seal in order to guarantee the integrity of the process. Visual image processing is then used for quality assurance to guarantee optimum sealing. The results described in this paper show examples of the capability of the condition monitoring system to detect faults in the sealing process. The results found indicate that the suggested approach could form an effective quality control and assurance system

    Household Decisions Regarding Charitable Gifts

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    Student, professor explore portrayal in Lincoln exhibition

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    https://thekeep.eiu.edu/lincoln_2015_news/1001/thumbnail.jp

    Student, professor explore portrayal in Lincoln exhibition

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    https://thekeep.eiu.edu/lincoln_2015_news/1001/thumbnail.jp

    Student, professor explore portrayal in Lincoln exhibition

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    https://thekeep.eiu.edu/lincoln_2015_news/1001/thumbnail.jp
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