2,081 research outputs found

    Wide-range logarithmic radiometer for measuring high temperatures

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    Filter radiometer utilizing photomultiplier circuit, in which a direct-coupled amplifier varies dynode voltage to maintain constant anode current, measures rapid variations of temperature of white-hot charred body at 2000 K to 3000 K

    The first relatively complete exoccipital-opisthotic from the braincase of the Callovian pliosaur, Liopleurodon

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    A newly recognized left exoccipital-opisthotic of a Callovian pliosaur, derived from the Peterborough or lower Stewarby Members of the Oxford Clay Formation of Peterborough, is described and figured. This isolated bone is tentatively identified as belonging to an ‘adult’ individual of Liopleurodon ferox that is inferred to have had a skull length of 1.26 metres and an overall body length of 6.39 metres

    Growth, age and size of the Jurassic pachycormid Leedsichthys problematicus (Osteichthyes: Actinopterygii)

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    The Jurassic pachycormid osteichthyan Leedsichthys problematicus is renowned for having been able to achieve prodigious size for a bony fish. Building on work of MARTILL (1986a), a thorough examination of all known material was conducted in order to constrain estimates of the size of this animal and examine its rate of growth. Important specimens of Leedsichthys are described for the first time. The histology of Leedsichthys is reviewed, and the presence of growth annuli is used to establish ages for five specimens. Age and growth data were obtained from gill rakers (n = 4) and lepidotrichia (n = 2). Lepidotrichia show upward curvilinear growth profiles and ages ranging from 21 to 40 annuli, which are assumed to represent years. Both growth profiles start at a small size (0.26 and 0.33 mm radial distance), which is assumed to represent age 1. However, annuli can be lost near the margins of the elements. Gill rakers exhibit a sigmoidal growth profile. Age of gill rakers was estimated by adjusting the alignment of the inflection points of the growth profiles thereby giving adjusted ages. Gill rakers ranged in age from 19–38 annuli, but all show evidence of reabsorption of annuli near the focal points and at the margins of most elements. Sizes for the five individuals range from 8.0-16.5 m for ages of 19-40 years. Growth rate (0.01-0.05 K) was relatively slow as expected for a large, long-lived fish. At age 1, individuals were 1.6 m in length. Estimates for the length of L. problematicus compare well with published lengths of other large suspension feeders such as those for basking and whale sharks

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    A preliminary study of air-pollution measurement by active remote-sensing techniques

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    Air pollutants are identified, and the needs for their measurement from satellites and aircraft are discussed. An assessment is made of the properties of these pollutants and of the normal atmosphere, including interactions with light of various wavelengths and the resulting effects on transmission and scattering of optical signals. The possible methods for active remote measurement are described; the relative performance capabilities of double-ended and single-ended systems are compared qualitatively; and the capabilities of the several single-ended or backscattering techniques are compared quantitatively. The differential-absorption lidar (DIAL) technique is shown to be superior to the other backscattering techniques. The lidar system parameters and their relationships to the environmental factors and the properties of pollutants are examined in detail. A computer program that models both the atmosphere (including pollutants) and the lidar system is described. The performance capabilities of present and future lidar components are assessed, and projections are made of prospective measurement capabilities for future lidar systems. Following a discussion of some important operational factors that affect both the design and measurement capabilities of airborne and satellite-based lidar systems, the extensive analytical results obtained through more than 1000 individual cases analyzed with the aid of the computer program are summarized and discussed. The conclusions are presented. Recommendations are also made for additional studies to investigate cases that could not be explored adequately during this study

    Adequacy of Communicating Results From Screening Mammograms to African American and White Women

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    Objective. We examined whether African American women were as likely as White women to receive the results of a recent mammogram and to self-report results that matched the mammography radiology report (i.e., were adequately communicated). We also sought to determine whether the adequacy of communication was the same for normal and abnormal results. Methods. From a prospective cohort study of mammography screening, we compared self-reported mammogram results, which were collected by telephone interview, to results listed in the radiology record of 411 African American and 734 White women who underwent screening in 5 hospital-based facilities in Connecticut between October 1996 and January 1998. Using multivariate logistic regression, we identified independent predictors of inadequate communication of mammography results. Results. It was significantly more common for African American women to experience inadequate communication of screening mammography results compared with White women, after adjustment for sociodemographic, access-to-care, biomedical, and psychosocial factors. Abnormal mammogram results resulted in inadequate communication for African American women but not White women (P\u3c.001). Conclusions. African American women may not be receiving the full benefit of screening mammograms because of inadequate communication of results, particularly when mammography results are abnormal

    Teens Surfing The Net: How Do They Learn To Protect Their Privacy?

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    This study invokes the consumer socialization process to investigate how teens develop knowledge of ‘privacy concern’ as it relates to protecting their privacy when using the Internet.  The data in this study show a correlation between teens that are raised in homes where parents practice concept-oriented family communication and the development of privacy concern.  The data also show a correlation between parental co-viewing of the Internet and the development of privacy concern.  Finally, the date link peer communication with the development of privacy concern.  Overall the date appear to show that discussion with parents and friends about Internet use is key to the development of adopting concern for protecting teens privacy when they use the Internet.&nbsp

    Man robbery : a gender signifier in convict Australia 1827-1836

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    This paper investigates the use of the anomalous term ‘man robbery’ in historical records relating to convict women in New South Wales. We question its accuracy as a criminal offence and conclude that its use in the 1830s was an administrative code that summarized an assessment not only of the women’s criminality but also of their morality. Its use in the historical records has been accepted uncritically by modern historians. The anomaly was identified through a large-scale study of these records. Often used to trace the histories of individual women for genealogical research, recurring patterns in the records are more noticeable when considering the crimes of some 5000 women transported to New South Wales, especially when their court records held in Britain are compared with those held in Australia. Evidence has emerged that the criminality of the women has been reduced by this gendered criminal offence. Inconsistency in the application of the term ‘man robbery’ led us to question it accuracy. Violence and participation in gangs were airbrushed from the records by the use of a term that implied that the women’s crimes related to their sexuality rather than their skills as criminals

    Dinosaur egg structure investigated by MRI

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    <p>In July 1993, the Hunterian Museum of the University of Glasgow was offered a sandstone block with a clutch of intact dinosaur eggs, from Hunan Province, China. Later, a number of single eggs were also acquired.</p> <p>An inter-disciplinary project began to investigate the structure of these eggs. Investigations carried out included egg shell structure analysis, protein analysis, and a program of imaging including CT|, neutron radiography, and MRI.</p> In this poster, the results of imaging the eggs in two commercial high field MRI scanners based at Glasgow hospitals, are presented. The MR scanners are Seimens 1.0 T Impact and 1.5 T Magnetom

    ECatSym - Electronic World Catalog of Symphyta : history and progress (Hymenoptera).

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    Die technische und inhaltliche Entwicklung des Elektronischen Weltkataloges der Pflanzenwespen (ECatSym) wird kurz dargestellt. - Derzeit (April 2005) sind ca. 8.200 valide Artgruppennamen und ca. 850 valide Gattungsgruppennamen enthalten, was einer Vollständigkeit von deutlich ßber 90% entspricht. Neben taxonomisch-nomenklatorischen Informationen umfasst die Datenbank umfangreiche Hinweise auf Futterpflanzen, die Verbreitung der Taxa sowie Literaturquellen.The content and technical development of the Electronic World Catalog of Symphyta (ECatSym) is briefly described. At present (April 2005) approximately 8.200 valid species group names and 850 genus group names are included. This represents significantly more than 90% of the known world fauna. As well as taxonomic and nomenclatural information, the database contains comprehensive data on foodplants, distribution and references
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