9,772 research outputs found

    External and internal noise surveys of London primary schools

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    Internal and external noise surveys have been carried out around schools in London, UK, to provide information on typical levels and sources to which children are exposed while at school. Noise levels were measured outside 142 schools, in areas away from flightpaths into major airports. 86% of the schools surveyed were exposed to noise from road traffic, the average external noise level outside a school being 57 dB LAeq. Detailed internal noise surveys have been carried out in 140 classrooms in 16 schools, together with classroom observations. It was found that noise levels inside classrooms depend upon the activities in which the children are engaged, with a difference of 20 dB LAeq between the 'quietest' and 'noisiest' activities. The average background noise level in classrooms exceeds the level recommended in current standards. The number of children in the classroom was found to affect noise levels. External noise influenced internal noise levels only when children were engaged in the quietest classroom activities. The effects of the age of the school buildings and types of window upon internal noise were examined but results were inconclusive

    Anatomy, morphology and evolution of the patella in squamate lizards and tuatara (Sphenodon punctatus)

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    The patella (kneecap) is the largest and best-known of the sesamoid bones, postulated to confer biomechanical advantages including increasing joint leverage and reinforcing the tendon against compression. It has evolved several times independently in amniotes, but despite apparently widespread occurrence in lizards, the patella remains poorly characterised in this group and is, as yet, completely undescribed in their nearest extant relative Sphenodon (Rhynchocephalia). Through radiography, osteological and fossil studies we examined patellar presence in diverse lizard and lepidosauromorph taxa, and using computed tomography, dissection and histology we investigated in greater depth the anatomy and morphology of the patella in 16 lizard species and 19 Sphenodon specimens. We have found the first unambiguous evidence of a mineralised patella in Sphenodon, which appears similar to the patella of lizards and shares several gross and microscopic anatomical features. Although there may be a common mature morphology, the squamate patella exhibits a great deal of variability in development (whether from a cartilage anlage or not, and in the number of mineralised centres) and composition (bone, mineralised cartilage or fibrotendinous tissue). Unlike in mammals and birds, the patella in certain lizards and Sphenodon appears to be a polymorphic trait. We have also explored the evolution of the patella through ancestral state reconstruction, finding that the patella is ancestral for lizards and possibly Lepidosauria as a whole. Clear evidence of the patella in rhynchocephalian or stem lepidosaurian fossil taxa would clarify the evolutionary origin(s) of the patella, but due to the small size of this bone and the opportunity for degradation or loss we could not definitively conclude presence or absence in the fossils examined. The pattern of evolution in lepidosaurs is unclear but our data suggest that the emergence of this sesamoid may be related to the evolution of secondary ossification centres and/or changes in knee joint conformation, where enhancement of extensor muscle leverage would be more beneficial.Sophie Regnault, Marc E. H. Jones, Andrew A. Pitsillides, John R. Hutchinso

    Response time to colored stimuli in the full visual field

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    Peripheral visual response time was measured in seven dark adapted subjects to the onset of small (45' arc diam), brief (50 msec), colored (blue, yellow, green, red) and white stimuli imaged at 72 locations within their binocular field of view. The blue, yellow, and green stimuli were matched for brightness at about 2.6 sub log 10 units above their absolute light threshold, and they appeared at an unexpected time and location. These data were obtained to provide response time and no-response data for use in various design disciplines involving instrument panel layout. The results indicated that the retina possesses relatively concentric regions within each of which mean response time can be expected to be of approximately the same duration. These regions are centered near the fovea and extend farther horizontally than vertically. Mean foveal response time was fastest for yellow and slowest for blue. Three and one-half percent of the total 56,410 trials presented resulted in no-responses. Regardless of stimulus color, the lowest percentage of no-responses occurred within 30 deg arc from the fovea and the highest within 40 deg to 80 deg arc below the fovea

    Valuation Of Closely Held Corporate Stock

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    Common Mudpuppy (Necturus maculosus) distribution, diet and seasonality in western New York and morphological condition in lake and stream habitats.

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    Environmental context changes the behavior and morphology of organisms. The impacts of flow on sampling techniques and morphology of the Common Mudpuppy were investigated during this study. I also explored mudpuppy distribution in western New York, diet, sexual dimorphism, seasonality, and capture biases. I found rock turning to be more efficient in streams year-round and modified minnow traps to be better more efficient in cold weather months and in deeper habitats than in other seasons or habitats. During the hot weather months, mudpuppy diet consisted of invertebrates exclusively, whereas diets in cold weather months consisted of invertebrates plus vertebrate prey. Body condition reflected the change in diet, with larger body condition when large prey items were found in gut contents. Stream-captured mudpuppies were more streamlined and possessed larger digits than lake-captured mudpuppies. Mudpuppy morphological differences between habitat types indicate phenotypic plasticity as the likely mechanism of morphological change when viewed in light of other published phylogenetic work on regional haplotypes. The findings of morphological response to flow warrant more investigation with common garden experiments. Expanding the common garden experiment to encompass future changes in temperature will help inform managers on how climate change may affect mudpuppy populations

    HMAP Dataset 05: Newfoundland, 1698-1833

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    The map below gives an indication of the extent of the Newfoundland-Labrador shelf; the 'view as map' link in the download panel at the right will show a much more detailed representation. The kml file download, when used with Google Earth, will render the extent of the Newfoundland-Labrador shelf in detail

    Creating a Female Athlete: The Power of Societal Reimaging and Advertising in the All American Girls Professional Baseball League

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    The All American Girls Professional Baseball League introduced an acceptable form of female sport to the United States during World War II. The All American Girls Professional Baseball League’s feminine image and high standards of the league provided a new quality team sport that the ever popular softball diamonds of industrial recreation had failed to reach. One of the reasons for their success was the attention to detail in the visual representation of the baseball league. Appearing in a time of heightened advertising and branding, a visual representation of the League was created to fit within the societal norms of the day by the original owner of the All American Girls Professional Baseball League, Philip K. Wrigley, and his trusty advertising executive, Arthur E. Meyerhoff. Using a concept I term “societal reimaging,” the thesis examines newspapers and organizational documents to view the changes and continuities of the All American Girls Professional Baseball League’s administrations and the ability of executives to present female athletes as feminine women
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