1,825 research outputs found
New Distributional Records and Natural History Notes on Selected Fishes from Arkansas
This report documents new records on the distribution of selected fishes from Arkansas and provides notes on their natural history. We document new geographic records for 21 species within 8 families in 12 counties of the state. Most importantly we have included new records for fishes ranked S1, S2 or S3 in the state by NatureServe and several Species of Special Concern by the Arkansas Game and Fish Commission (AGFC). Additional collections of fishes in the state will undoubtedly provide more records especially with the use of electroshocking devices as has been shown herein
Characteristics of Two-Dimensional Quantum Turbulence in a Compressible Superfluid
Under suitable forcing a fluid exhibits turbulence, with characteristics
strongly affected by the fluid's confining geometry. Here we study
two-dimensional quantum turbulence in a highly oblate Bose-Einstein condensate
in an annular trap. As a compressible quantum fluid, this system affords a rich
phenomenology, allowing coupling between vortex and acoustic energy.
Small-scale stirring generates an experimentally observed disordered vortex
distribution that evolves into large-scale flow in the form of a persistent
current. Numerical simulation of the experiment reveals additional
characteristics of two-dimensional quantum turbulence: spontaneous clustering
of same-circulation vortices, and an incompressible energy spectrum with
dependence for low wavenumbers and dependence for high
.Comment: 7 pages, 7 figures. Reference [29] updated for v
Dynamic Control of Laser Produced Proton Beams
The emission characteristics of intense laser driven protons are controlled
using ultra-strong (of the order of 10^9 V/m) electrostatic fields varying on a
few ps timescale. The field structures are achieved by exploiting the high
potential of the target (reaching multi-MV during the laser interaction).
Suitably shaped targets result in a reduction in the proton beam divergence,
and hence an increase in proton flux while preserving the high beam quality.
The peak focusing power and its temporal variation are shown to depend on the
target characteristics, allowing for the collimation of the inherently highly
divergent beam and the design of achromatic electrostatic lenses.Comment: 9 Pages, 5 figure
Combination Forecasts of Bond and Stock Returns: An Asset Allocation Perspective
We investigate the out-of-sample forecasting ability of the HML, SMB, momentum, short-term and long-term reversal factors along with their size and value decompositions on U.S. bond and stock returns for a variety of horizons ranging from the short run (1 month) to the long run (2 years). Our findings suggest that these factors contain significantly more information for future bond and stock market returns than the typically employed financial variables. Combination of forecasts of the empirical factors turns out to be particularly successful, especially from an an asset allocation perspective. Similar findings pertain to the European and Japanese markets
Soft X-ray harmonic comb from relativistic electron spikes
We demonstrate a new high-order harmonic generation mechanism reaching the
`water window' spectral region in experiments with multi-terawatt femtosecond
lasers irradiating gas jets. A few hundred harmonic orders are resolved, giving
uJ/sr pulses. Harmonics are collectively emitted by an oscillating electron
spike formed at the joint of the boundaries of a cavity and bow wave created by
a relativistically self-focusing laser in underdense plasma. The spike
sharpness and stability are explained by catastrophe theory. The mechanism is
corroborated by particle-in-cell simulations
Do women athletes’ experiences of menstrual function and dysfunction vary across competition levels? A mixed methods exploration
Menstrual dysfunction is a common phenomenon in sport and many women describe that their menstrual cycle can negatively impact their sport participation, performance, and experiences. However, there is little research examining if competition level plays a role in women athletes’ rates and experiences of menstrual function and dysfunction. Therefore, the purpose of this study was to explore and describe rates and experiences of menstrual function and dysfunction among athletes of differing competition levels. An online mixed methods approach was applied. Women athletes (N = 63), between 14 and 39 years of age (M = 24.20, SD = 6.53), competing in a range of sports from the local to international level completed an anonymous interview style survey to generate data. Data analysis for this project was an iterative and integrated process where quantitative and qualitative data were considered together and are represented through reported statistics and generated themes. Although group differences were hypothesized, no differences based on competition level in rates or experiences of menstrual dysfunction were observed. In addition to detailed descriptive statistics, five themes were generated: Normalizing Dysfunction; Menstrual Symptoms; Clothing as a Distraction; Participation Impact; and Regaining Control. In line with previous research, the women in this study experienced a range of menstrual dysfunctions that impacted their sport experiences. However, this study highlights that regardless of competition level or sport type women face challenges in sport regarding menstrual function and due to the normalization of dysfunction in sport women athletes’ health and well-being are not always supported
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Scutellaria Extract Inhibits Proliferation and Migration of Brain-Metastatic Lung Cancer Cells via Regulation of Multiple Signaling Pathways
Measuring Servitization Progress and Outcome:The Case of ‘Advanced Services’
The purpose of this paper is to establish a framework for assessing the progress and outcome of a manufacturer’s transformation towards becoming a provider of ‘advanced services’ – a complex bundling of products and services, whereby manufacturers offer capabilities and outcomes instead of products alone. ‘Advanced services’ represent the most complex offering in the current servitization trend among manufacturers. However, current performance measures lack the breadth and focus to assess progress or outcomes, and so support research and practice of organisational transformation efforts required. To address this gap the paper investigates how a manufacturer’s efforts to become an ‘advanced services’ provider can be comprehensively measured, and develops a framework for assessing the transformation journey towards becoming an ‘advanced services’ provider. The research method is based on (1) a systematic literature review process to create a comprehensive set of service-related performance measures that are available to assess a manufacturer’s servitization efforts, followed by (2) an engagement with an expert panel to synthesise the identified measures and create a set of ‘advanced services’ performance measures. The proposed framework is presented as a scorecard that can be used in practice to assess the progress and outcome of a manufacturer’s transformation towards becoming a provider of ‘advanced services’
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