12,791 research outputs found
Impacts of the herbicide glyphosate on moose browse and moose use of four paired treated-control cutovers near Thunder Bay, Ontario
Re-assessment of the aerial and ground observations on
four paired, glyphosate treated and control, cutovers near
Thunder Bay, Ontario, indicated that aerial tending with
glyphosate altered the use of these cutovers by moose.
The number of pellet groups favoured the control areas (p
< 0.05) by 1.5 times. Additionally, the number of moose
tracks and moose track aggregates were more prevalent (p <
0.05) on the controls for 2 to 3 years after treatment. Pre
spray data on 2 areas suggested use shifted away from
glyphosate treated areas.
Browse availability was significantly greater (p < 0.05)
on the control plots by 18 times in the highest height class
measured (201 - 350 cm) , 5 times in the next highest (101 -
200 cm) but not statistically significant (p > 0.05) in the
lowest (51 - 100 cm), 2 years after treatment. Due to too few
replications, differences in availability 1 year after
treatment were not statistically significant.
Biomass of browse removed by moose was 3 to 7 times
greater on controls but again these differences were not
statistically significant.
The average length of moose trails observed in the snow
was shorter (p < 0.05) on the controls suggesting less travel
time. The size (area) of moose track aggregates was the same
(p > 0.05) between treatments indicating equal search time
while browsing.
A carrying capacity model indicated that if all cutovers
were sprayed, the treatment would have a negative impact on
moose densities.
Glyphosate treatments should be dispersed to create a
mosaic of glyphosate treated areas next to non-treated areas.
Similarily, areas of seasonal importance such as aquatics,
salt licks, and calving areas should have at least a non-sprayed
buffer beside them if the adjacent cut area must be
treated with glyphosate
Health considerations for the year 2000
As the swine industry matures, profit margins will decrease. Control of the major factors affecting feed cost will drive the system. Upgrading or maintaining health will be a major emphasis, because disease agents and complexes affect growing-finishing performance. Many diseases, such as pneumonia caused by Actinobacillus (llaemophilus) pleuropneumonia and swine dysentery, dramatically affect growing-finishing performance. Diseases decrease average daily feed intake (ADFI) and increase feed per gain ratio (FIG) in many instances. At the same time, they increase input costs via treatments, vaccines, and feed additives. Historically, our control methods may have been successful on individual farms, but not across large populations. Because of the dynamics of disease complexes, it has been difficult to understand the disease agents and/or their interactions, let alone define a cost-effective method of control or elimination. However, several new techniques offer hope of optimizing the genetic capability of growing-finishing pigs with respect to average daily gain (ADG) and F/G. These control measures become more important as restrictions increase on therapeutic feed additives, injectables, and the producer\u27s goal of providing a pork product untainted by residues of any kind. Likewise, in the future, available carcass-enhancing products, such as Ractopamine, may not allow simultaneous use of therapeutics, requiring production systems with pigs of high health status.; Swine Day, Manhattan, KS, November 21. 199
Review: short acting methylphenidate has short term efficacy in children and adolescents with attention deficit disorder
Once a day Concerta methylphenidate was equivalent to 3 times daily methylphenidate in children with ADHD
GPS enabled semi-autonomous robot
The primary objective of this research is to integrate GPS and local sensory data to allow a robot to operate semi-autonomously outside of a laboratory environment. The Pioneer 3-AT, a robust platform capable of operating in the outdoors, is utilized in this thesis. The P3-AT has acoustic sensors that can calculate distances to obstacles and encoders that calculate how much each wheel has turned. In a laboratory environment, sensory and encoder information can be used to triangulate position or measure distance and direction traveled from a known starting point. Operating outdoors limits the effectiveness of both systems as the obstacles are not known and wheels can often slip and slide on different surfaces. This necessitates external data to determine the location of the robot. GPS was chosen to provide that data. GPS, acoustic, and encoder data were integrated within MATLAB and provided control signals to the robot. The robot successfully navigated to a user-defined goal.http://archive.org/details/gpsenabledsemiau1094556103Lieutenant, United States NavyApproved for public release; distribution is unlimited
Effect of current corrugations on the stability of the tearing mode
The generation of zonal magnetic fields in laboratory fusion plasmas is
predicted by theoretical and numerical models and was recently observed
experimentally. It is shown that the modification of the current density
gradient associated with such corrugations can significantly affect the
stability of the tearing mode. A simple scaling law is derived that predicts
the impact of small stationary current corrugations on the stability parameter
. The described destabilization mechanism can provide an explanation
for the trigger of the Neoclassical Tearing Mode (NTM) in plasmas without
significant MHD activity.Comment: Accepted to Physics of Plasma
Study of the spectral properties of ELM precursors by means of wavelets
The high confinement regime (H-mode) in tokamaks is accompanied by the occurrence of bursts of MHD activity at the plasma edge, so-called edge localized modes (ELMs), lasting less than 1 ms. These modes are often preceded by coherent oscillations in the magnetic field, the ELM precursors, whose mode numbers along the toroidal and the poloidal directions can be measured from the phase shift between Mirnov pickup coils. When the ELM precursors have a lifetime shorter than a few milliseconds, their toroidal mode number and their nonlinear evolution before the ELM crash cannot be studied reliably with standard techniques based on Fourier analysis, since averaging in time is implicit in the computation of the Fourier coefficients. This work demonstrates significant advantages in studying spectral features of the short-lived ELM precursors by using Morlet wavelets. It is shown that the wavelet analysis is suitable for the identification of the toroidal mode numbers of ELM precursors with the shortest lifetime, as well as for studying their nonlinear evolution with a time resolution comparable to the acquisition rate of the Mirnov coils
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