1,745 research outputs found

    Three months journeying of a Hawaiian monk seal

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    Hawaiian monk seals (Monachus schauinslandi) are endemic to the Hawaiian Islands and are the most endangered species of marine mammal that lives entirely within the jurisdiction of the United States. The species numbers around 1300 and has been declining owing, among other things, to poor juvenile survival which is evidently related to poor foraging success. Consequently, data have been collected recently on the foraging habitats, movements, and behaviors of monk seals throughout the Northwestern and main Hawaiian Islands. Our work here is directed to exploring a data set located in a relatively shallow offshore submerged bank (Penguin Bank) in our search of a model for a seal's journey. The work ends by fitting a stochastic differential equation (SDE) that mimics some aspects of the behavior of seals by working with location data collected for one seal. The SDE is found by developing a time varying potential function with two points of attraction. The times of location are irregularly spaced and not close together geographically, leading to some difficulties of interpretation. Synthetic plots generated using the model are employed to assess its reasonableness spatially and temporally. One aspect is that the animal stays mainly southwest of Molokai. The work led to the estimation of the lengths and locations of the seal's foraging trips.Comment: Published in at http://dx.doi.org/10.1214/193940307000000473 the IMS Collections (http://www.imstat.org/publications/imscollections.htm) by the Institute of Mathematical Statistics (http://www.imstat.org

    Welding Design and Construction

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    Large scale motions of Neptune's bow shock: Evidence for control of the shock position by the rotation phase of Neptune's magnetic field

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    The Voyager 2 spacecraft observed high levels of Langmuir waves before the inbound crossing of Neptune's bow shock, thereby signifying magnetic connection of the bow shock. The Langmuir waves occurred in multiple bursts throughout two distinct periods separated by an 85 minute absence of wave activity. The times of onsets, peaks, and disappearances of the waves were used together with the magnetic field directions and spacecraft position, to perform a 'remote-sensing' analysis of the shape and location of Neptune's bow shock prior to the inbound bow shock crossing. The bow shock is assumed to have a parabolidal shape with a nose location and flaring parameter determined independently for each wave event. The remote-sensing analysis give a shock position consistent with the time of the inbound shock crossing. The flaring parameter of the shock remains approximately constant throughout each period of wave activity but differs by a factor of 10 between the two periods. The absence of waves between two periods of wave activity coincides with a large rotation of the magnetic field and a large increase in the solar wind ram pressure' both these effects lead to magnetic disconnection of the spacecraft from shock. The planetwards motion of the shock's nose from 38.5 R(sub N) to 34.5 R(sub N) during the second time period occurred while the solar wind ram pressure remained constant to within 15 percent. This second period of planetwards motion of the shock is therefore strong evidence for Neptune's bow shock moving in response to the rotation of Neptune's oblique, tilted magnetic dipole. Normalizing the ram pressure, the remotely-sensed shock moves sunwards during the first wave period and planetwards in the second wave period. The maximum standoff distance occurs while the dipole axis is close to being perpendicular to the Sun-Neptune direction. The remote-sensing analysis provides strong evidence that the location of Neptune's bow shock is controlled by Neptune's rotation phase

    Reflections on the VTP's contributions to science, policymaking and education

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    In the immediate wake of the 2000 presidential election, the Caltech/MIT Voting Technology Project was initiated. The initial and primary concern of the VTP at that moment was to understand the problems that arose in the 2000 American presidential election, in particular with regards to voting technologies, and to develop scientifically-based proposals for reforms and perhaps even to propose new voting technologies. In the past decade, the VTP has moved from that original focus to become an internationally-renown group of researchers who now focus on a broad array of election administration issues

    Accounting Program Assessment: Exit Interviews of Graduating Seniors

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    Exit interviews of university graduating seniors have been used to a very limited extent when evaluating academic programs.Ā  It is our belief that developing and implementing an exit interview plan stimulates faculty dialog and improves ongoing feedback for department program assessment.Ā  From 2001 to 2007, the Accounting Department at Towson University has conducted exit interviews with all graduating seniors as part of the annual internal department assessment activities.Ā  The exit interviews have served to assist the Department of Accounting in evaluating its performance as judged by the students served.Ā  The positive comments assist to reinforce the quality activities of the department, while the negative comments permit the department to become aware of areas of perceived weakness that are in need of improvement.Ā Ā  By receiving annual feedback from a valuable, relevant source, the department is able to continuously monitor, adjust, and improve its performance

    Research Knowledge of Advanced Standing and Traditional Students: Implications for BSW Education

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    The advanced standing model of social work education, which affords graduate credit to qualified BSW students who pursue their MSW, has not been without issue or controversy, including questions of potential differences in performance on various educational outcomes. Specifically related to research curriculum, the importance of which is often not wholly embraced by students, this article reports the results of a secondary data analysis comparing research knowledge among advanced standing and traditional MSW students as well as among the various undergraduate majors (i.e., BSW, psychology, and sociology). Results suggest that research knowledge is similar and low across student subgroups. Important differences in research knowledge were found among student groups based on undergraduate major, with BSW undergraduates without advanced standing, on average, scoring lower than any other group. Implications for BSW research curriculum are considere

    Effects of zinc supplementation on cognitive function in healthy middle-aged and older adults: the ZENITH study

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    A randomised double-blind placebo-controlled design was employed to investigate the effects of Zn supplementation on cognitive function in 387 healthy adults aged 55ā€“87 years. Several measures of visual memory, working memory, attention and reaction time were obtained using the Cambridge Automated Neuropsychological Test Battery at baseline and then after 3 and 6 months of 0 (placebo), 15 or 30 mg Zn/d. Younger adults (70 years), and performance improved with practice on some measures. For two out of eight dependent variables, there were significant interactions indicating a beneficial effect (at 3 months only) of both 15 and 30 mg/d on one measure of spatial working memory and a detrimental effect of 15 mg/d on one measure of attention. Further work is required to establish whether these findings generalise to older adults in poorer mental and physical health and with less adequate Zn intake and status than the present sample

    Comparing Peripheral Olfactory Coding with Host Preference in the Rhagoletis Species Complex

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    Recent studies have shown that flies from sympatric populations of Rhagoletis pomonella infesting hawthorn, apple, and flowering dogwood fruit can distinguish among unique volatile blends identified from each host. Analysis of peripheral chemoreception in Rhagoletis flies suggests that changes in receptor specificity and/or receptor neuron sensitivity could impact olfactory preference among the host populations and their hybrids. In an attempt to validate these claims, we have combined flight tunnel analyses and single sensillum electrophysiology in F2 and backcross hybrids displaying a variety of behavioral phenotypes. Results show that differences in peripheral chemoreception among second-generation adults do not provide a direct correlation between peripheral coding and olfactory behavior. We conclude that either the plasticity of the central nervous system in Rhagoletis can compensate for significant alterations in peripheral coding or that peripheral changes present subtle effects on behavior not easily detectable with current techniques. The results of this study imply that the basis for olfactory behavior in Rhagoletis has a complicated genetic and neuronal basis, even for populations with a recent divergence in preferenc

    Voting: What Has Changed, What Hasn't, & Why: Research Bibliography

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    Since the origins of the Caltech/MIT Voting Technology Project in the fall of 2000, there has been an explosion of research and analysis on election administration and voting technology. As we worked throughout 2012 on our most recent study, Voting: What Has Changed, What Hasnā€™t, & What Needs Improvement, we found many more research studies. In this research bibliography, we present the research literature that we have found; future revisions of this research bibliography will update this list.Carnegie Corporation of New Yor
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