13,533 research outputs found
The effect of a trapping procedure on the stress response of wild rainbow trout
Fish traps are a common research and management tool in which fish are subjected to procedures that elicit a stress response in other contexts. The effects of trapping on the stress response of sexually mature, wild rainbow trout Oncorhynchus mykiss were investigated during their upstream spawning migration by measuring concentrations of plasma cortisol, lactate, and glucose. Males had significantly lower basal plasma cortisol concentrations (6.1 ± 0.8 ng/mL [mean ± SE]) than females (21.4 ± 5.9 ng/mL). Similarly, the plasma cortisol response in males was significantly lower than that in females for all experiments. Fish working the barrier before entering the trap had increased concentrations of plasma cortisol. Confinement in the trap also induced a stress response. Plasma cortisol concentrations increased to 185.1 ± 40.9 ng/mL in males and 549.1 ± 60.1 ng/mL in females after confinement for 1 h. After processing, the magnitude of the stress response and the relative duration of recovery was less in fish that were confined longer in the trap. However, resting cortisol concentrations in females were not reached after 40 h of recovery in either group. Recovery to resting concentrations of plasma lactate occurred within 15 h after processing. In contrast, concentrations of plasma glucose remained significantly elevated at 40 h after processing. Postspawning fish had significantly lower plasma concentrations of cortisol, glucose, and lactate following application of an extreme stressor compared with prespawning fish. Based on the results of this study, we conclude that the trapping procedure induces a severe and prolonged stress response in wild rainbow trout
An evaluation of the method for determining the Whitham F-function using distributions of downwash and sidewash angles
The method of computing the Whitham F function using distributions of downwash and sidewash angles was evaluated with two different models. F functions which were calculated for a half angle cone cylinder at M infinites = 2.01, using theoretically and experimentally derived flow angles, show that the method is sensitive to small inaccuracies in the measured flow angles. An oblique wing transport model was tested at 0 deg angle of attack at M infinitely = 2.01. In this test, two different probes were used at two different distances from the model. The pressure signature derived from the F function was extrapolated and compared to the pressure signature measured at the distance of 0.87 body lengths with the static pressure probe. The agreement between the two pressure signatures was poor due to the many inaccuracies involved in using a probe designed to measure flow angularity
Sparse experimental design : an effective an efficient way discovering better genetic algorithm structures
The focus of this paper is the demonstration that sparse experimental design is a useful strategy for developing Genetic Algorithms. It is increasingly apparent from a number of reports and papers within a variety of different problem domains that the 'best' structure for a GA may be dependent upon the application. The GA structure is defined as both the types of operators and the parameters settings used during operation. The differences observed may be linked to the nature of the problem, the type of fitness function, or the depth or breadth of the problem under investigation. This paper demonstrates that advanced experimental design may be adopted to increase the understanding of the relationships between the GA structure and the problem domain, facilitating the selection of improved structures with a minimum of effort
Imaging with two-axis micromirrors
We demonstrate a means of creating a digital image by using a two axis tilt
micromirror to scan a scene. For each different orientation we extract a single
grayscale value from the mirror and combine them to form a single composite
image. This allows one to choose the distribution of the samples, and so in
principle a variable resolution image could be created. We demonstrate this
ability to control resolution by constructing a voltage table that compensates
for the non-linear response of the mirrors to the applied voltage.Comment: 8 pages, 5 figures, preprin
Some Effects of Wing Planform on Sonic Boom
A wind-tunnel investigation was conducted to determine the effect of wing planform on sonic boom at Mach numbers of 1.7, 2.0, and 2.7. The results of the investigation show that the wing leading-edge sweep is one of the primary planform variables affecting the overpressure characteristics
Unsportsmanlike Conduct: Female Sportswriters as Targets for Sexual Harassment
Professional sports are big business in the United States, and so perhaps it is no surprise that reporters from magazines, newspapers, and television shows and networks flock to pro locker rooms and practice fields to interview the players and coaches. The situation can become a bit more complex when the person on the other end of the microphone is a woman. Female sportswriters often find themselves as targets for sexual harassment and lewd behavior. This Note considers the possible legal options that sportswriters may have when they are victimized by the athletes and coaches they are charged with reporting on. However, because a showing of severity or pervasiveness is necessary to state a claim, most reporters\u27 experiences fall short of the requirements for a Title VII sexual harassment suit. While various tort claims may provide for recovery, this Note proposes that a far better solution could come from the teams and organizations themselves. All professional sports leagues can and should develop comprehensive media policies that clearly set forth behavioral expectations, both of the players and the media. Teams should undergo training specifically tailored to the unique circumstances of professional sports, and a combination of meaningful fines plus suspensions should be the consequence for players that engage in inappropriate behavior
Effect of Applied Orthorhombic Lattice Distortion on the Antiferromagnetic Phase of CeAuSb
We study the response of the antiferromagnetism of CeAuSb to orthorhombic
lattice distortion applied through in-plane uniaxial pressure. The response to
pressure applied along a lattice direction shows a
first-order transition at zero pressure, which shows that the magnetic order
lifts the symmetry of the unstressed lattice. Sufficient
pressure appears to rotate the principal axes of the
order from to . At low pressure, the transition at is weakly first-order, however it
becomes continuous above a threshold pressure. We discuss
the possibility that this behavior is driven by order parameter fluctuations,
with the restoration of a continuous transition a result of reducing the
point-group symmetry of the lattice.Comment: 6 pages, 7 figure
- âŠ