663 research outputs found

    Post-flood recovery and distributions of fishes in the New River Gorge National River, West Virginia

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    The following thesis contains three chapters. The first chapter introduces and reviews literature on disturbances in streams (e.g. flood and drought), recovery of impacted lotic systems, introduced species and New River fish distributions. Chapter 2 provides a synthesis of native and nonnative fish distribution data of the New River Gorge National River (NRGNR). Sixty-two species were documented within or near the NRGNR. Thirty-one (50%) are considered nonnative. The third chapter consists of a study that estimated seasonal abundances of native and nonnative fishes in small tributaries of NRGNR during a 20 month time period following July 2001 floods, and examined among-season stability in abundances of native and nonnative fishes across the 20-month time series. Twenty-nine species were observed (15 native and 14 nonnative) and patterns of recovery were influenced primarily by four natives (stoneroller, blacknose, dace, creek chub, and green sunfish) and four nonnatives (telescope shiner, whitetail shiner, smallmouth bass, and rainbow darter). Abundances of most species did not increase monotonically over the 20-month study period, but fluctuated among seasons. Abundances of nonnative fishes were generally less stable than those of natives across the 20-month time series. Seasonal variation in abundances among species was attributed to historic ecological factors, summer drought, immigration and emigration associated with seasonal habitat shifts, and juvenile recruitment

    Hover Acoustic Characteristics of the XV-15 with Advanced Technology Blades

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    An experiment has been performed to investigate the far-field hover acoustic characteristics of the XV-15 aircraft with advanced technology blades (ATB). An extensive, high-quality, far-field acoustics data base was obtained for a rotor tip speed range of 645-771 ft/s. A 12-microphone, 500-ft radius semicircular array combined with two aircraft headings provided acoustic data over the full 360-deg azimuth about the aircraft with a resolution of 15 deg. Altitude variations provided data from near in-plane to 45 deg below the rotor tip path plane. Acoustic directivity characteristics in the lower hemisphere are explored through pressure time histories, narrow-band spectra, and contour plots. Directivity patterns were found to vary greatly with azimuth angle, especially in the forward quadrants. Sharp positive pressure pulses typical of blade-vortex interactions were found to propagate aft of the aircraft and were most intense at 45 deg below the rotor plane. Modest overall sound pressure levels were measured near in-plane indicating that thickness noise is not a major problem for this aircraft when operating in the hover mode with ATB. Rotor tip speed reductions reduced the average overall sound pressure level (dB (0.0002 dyne/cm(exp 2)) by nearly 8 dB in-plane, and 12.6 deg below the rotor plane

    Undergraduate pre-registration nursing education in Australia: a longitudinal examination of enrolment and completion numbers with a focus on students from rural and remote campus locations

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    Introduction: There is much evidence to indicate a shortage of Registered Nurses (RNs) in Australia and to suggest that the shortage may be more pronounced in rural and remote locations. Attracting RNs to work in rural and remote areas may not be as simple as increasing the intake of students into university undergraduate pre-registration nursing courses. There is some evidence indicating that student nurses may be more likely to enter the nursing workforce in rural and remote locations if they have existing associations with rural and remote areas and/or their undergraduate education provides opportunities to undertake supported placements in rural and remote settings. Two important difficulties have been associated with measuring outcomes in relation to rural and remote pre-registration nursing students. One is defining what constitutes a rural or remote location and the other is suspect data on the number of nursing students enrolled in, and completing, nursing courses. The aims of this study were to provide a longitudinal profile of the number of domestic students studying and completing undergraduate pre-registration nursing courses in Australia, with a particular emphasis on identifying those at rural and remote university campuses, and to compare results across States and Territories.Method: This study presents the combined findings from two investigative reports. Data on undergraduate pre-registration nursing student numbers were collected via electronic survey instruments completed by staff at all Australian educational institutions offering undergraduate pre-registration nursing education programs in 2001 and 2002. Australian domestic students were the focus of this study. Data included the total number of domestic students enrolled in undergraduate pre-registration nursing courses in 2001 and 2002, the number of domestic students who successfully completed courses in 1999, 2000 and 2001, and estimates for the number expected to complete in 2002. Surveys were sent to course coordinators or other staff nominated by heads of divisions of nursing at each institution.Results: There was a 100% response rate. Twenty-four rural and remote campus locations were identified using an adjusted form of the Rural, Remote and Metropolitan Areas (RRMA) classification system. The Australian Capital Territory and the Northern Territory did not have any rural or remote campus locations. In contrast, undergraduate pre-registration nursing in Tasmania was offered at a rural campus only (for the first 2 years). From 2001 to 2002, there was an increase of just over 5% in the total number of domestic students enrolled in undergraduate pre-registration nursing courses in Australia (2002 total = 22 811 students). Rural and remote location students accounted for slightly more than 25% of these students in 2001, and almost 27% in 2002. The States Victoria, New South Wales and Queensland had the highest percentage of students enrolled at rural and remote campus locations, greater than the Australian average for both years. In contrast, South Australia and Western Australia had less than 11% of students enrolled at rural and remote campus locations for each year. Total undergraduate pre-registration course completions increased by approximately 16% across Australia between 1999 (n = 4868) and 2002 (n = 5667), although for 2002, the figure was projected. Of these total course completions, the percentage of students completing at rural and remote campus locations increased from almost 23% to nearly 28% during the same period. Of the States/Territories with both metropolitan and rural/remote campus locations, only Victoria and Queensland had more than 25% of their total student completions consisting of students enrolled at rural and remote campus locations for each year. In contrast, South Australia and Western Australia had approximately 6% of student completions consisting of students enrolled at rural and remote campus locations in 1999, increasing to approximately 12% projected for 2002.Conclusion: In this study, the authors attempted to improve the accuracy of data collection in relation to the number of domestic undergraduate pre-registration nursing students in Australia, which is representative of the potentially new Australian domestic RN workforce. There was a trend towards an increasing number of students being enrolled in undergraduate pre-registration nursing courses, and also toward an increasing number of course completions. From the perspective of the rural and remote RN workforce, the percentage of students enrolled and completing courses at rural and remote campus locations was found to be increasing. However, there may be some areas of concern for education and workforce planners in States and Territories that are providing a smaller percentage of their undergraduate pre-registration nursing courses in rural and remote areas. Several study limitations are discussed and suggestions made for future research.<br /

    Neural correlates of belief‐ and desire‐reasoning in 7‐ and 8‐year‐old children: an event‐related potential study

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    Theory of mind requires belief‐ and desire‐understanding. Event‐related brain potential (ERP) research on belief‐ and desire‐reasoning in adults found mid‐frontal activations for both desires and beliefs, and selective right‐posterior activations only for beliefs. Developmentally, children understand desires before beliefs; thus, a critical question concerns whether neural specialization for belief‐reasoning exists in childhood or develops later. Neural activity was recorded as 7‐ and 8‐year‐olds ( N  = 18) performed the same diverse‐desires, diverse‐beliefs, and physical control tasks used in a previous adult ERP study. Like adults, mid‐frontal scalp activations were found for belief‐ and desire‐reasoning. Moreover, analyses using correct trials alone yielded selective right‐posterior activations for belief‐reasoning. Results suggest developmental links between increasingly accurate understanding of complex mental states and neural specialization supporting this understanding. Theory of mind requires belief‐ and desire‐understanding. Event‐related brain potential (ERP) research on belief‐ and desire‐reasoning in adults found mid‐frontal activations for both desires and beliefs, and selective right‐posterior activations only for beliefs. Developmentally, children understand desires before beliefs; thus, a critical question concerns whether neural specialization for belief‐reasoning exists in childhood or develops later. Neural activity was recorded as 7‐ and 8‐year‐olds ( N  = 18) performed the same diverse‐desires, diverse‐beliefs, and physical control tasks used in a previous adult ERP study.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/93540/1/j.1467-7687.2012.01158.x.pd

    Reducing instruction fetch energy with backwards branch control information and buffering

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    Many emerging applications, e.g. in the embedded and DSP space, are often characterized by their loopy nature where a substantial part of the execution time is spent within a few program phases. Loop buffering techniques have been proposed for capturing and processing these loops in small buffers to reduce the processor‘s instruction fetch energy. However, these schemes are limited to straight-line or inner-most loops and fail to adequately handle complex loops. In this paper, we propose a dynamic loop buffering mech-anism that uses backwards branch control information to identify, capture and process complex loop structures. The DLB controller has been fully implemented in VHDL, syn-thesized and timed with the IBM Booledozer and Einstimer Synthesis tools, and analyzed for power with the Sequence PowerTheater tool. Our experiments show that the DLB approach, on average, results in a factor of 3 reduction in energy consumption compared to a traditional instruction memory design at an area overhead of about 9%
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