3,971 research outputs found
Circular 87
High rates of female breeding success and offspring survival are
the two major factors in productivity of any commercial livestock
industry. To im prove breeding success and offspring survival, the
herd m anager will establish selection criteria and choose which
males and females will breed. The genetics or characteristics of future
animals will reflect their parentage.
Selection pressure is evident in both wild and captive populations
of herbivores. Predators, environment, and human harvest
strategies are a few forces which influence the characteristics of freeranging
populations of reindeer, caribou, moose, wapiti, etc. In
livestock production systems, herd managers often breed for specific
characteristics such as larger body size, high birth and growth rates,
leanness, etc. A single color or combination of colors has been
another characteristic often selected by purebred cattle producers as
well as reindeer herders
Alien Registration- Blake, John E. (Bangor, Penobscot County)
https://digitalmaine.com/alien_docs/14433/thumbnail.jp
ROCK CLIMBING HELMET IMPACT PERFORMANCE VARIES BY HELMET MODEL TYPE
The purpose of this study was to compare the impact performance of a sample of rock climbing helmets. Each helmet was impacted at three locations (front, side, and back) and three impact speeds (2 m/s, 3.85 m/s, and 5 m/s) using a custom pendulum impactor. Peak resultant linear and rotational accelerations were compared by impact speed. The results of this study show that acceleration varies by helmet model and impact location. Differences in acceleration by helmet model support the need for relative performance ratings of rock climbing helmets. These tests can be used as the basis of methods to compare relative helmet performance. Relative performance evaluation would inform consumers of the safety of different helmet types, and would also inform manufacturers where improvements in helmet designs should be made
Relating multi-sequence longitudinal intensity profiles and clinical covariates in new multiple sclerosis lesions
Structural magnetic resonance imaging (MRI) can be used to detect lesions in
the brains of multiple sclerosis (MS) patients. The formation of these lesions
is a complex process involving inflammation, tissue damage, and tissue repair,
all of which are visible on MRI. Here we characterize the lesion formation
process on longitudinal, multi-sequence structural MRI from 34 MS patients and
relate the longitudinal changes we observe within lesions to therapeutic
interventions. In this article, we first outline a pipeline to extract voxel
level, multi-sequence longitudinal profiles from four MRI sequences within
lesion tissue. We then propose two models to relate clinical covariates to the
longitudinal profiles. The first model is a principal component analysis (PCA)
regression model, which collapses the information from all four profiles into a
scalar value. We find that the score on the first PC identifies areas of slow,
long-term intensity changes within the lesion at a voxel level, as validated by
two experienced clinicians, a neuroradiologist and a neurologist. On a quality
scale of 1 to 4 (4 being the highest) the neuroradiologist gave the score on
the first PC a median rating of 4 (95% CI: [4,4]), and the neurologist gave it
a median rating of 3 (95% CI: [3,3]). In the PCA regression model, we find that
treatment with disease modifying therapies (p-value < 0.01), steroids (p-value
< 0.01), and being closer to the boundary of abnormal signal intensity (p-value
< 0.01) are associated with a return of a voxel to intensity values closer to
that of normal-appearing tissue. The second model is a function-on-scalar
regression, which allows for assessment of the individual time points at which
the covariates are associated with the profiles. In the function-on-scalar
regression both age and distance to the boundary were found to have a
statistically significant association with the profiles
Looking for Pure Rotational H_2 Emission from Protoplanetary Disks
We report on a limited search for pure-rotational molecular hydrogen emission
associated with young, pre-main-sequence stars. We looked for H_2 v=0 J = 3->1
and J = 4->2 emission in the mid-infrared using the Texas Echelon-Cross-Echelle
Spectrograph (TEXES) at NASA's 3m Infrared Telescope Facility. The high
spectral and spatial resolution of our observations lead to more stringent
limits on narrow line emission close to the source than previously achieved.
One star, AB Aur, shows a possible (2sigma) H_2 detection, but further
observations are required to make a confident statement. Our non-detections
suggest that a significant fraction, perhaps all, of previously reported H_2
emission towards these objects could be extended on scales of 5" or more.Comment: 14 pages including 2 figures. Accepted by ApJ Letter
Use of Roadside Deer Removal to Reduce DeerâVehicle Collisions
Identification of management tools to reduce the incidence of deerâvehicle collisions (DVCs) is important to improve motorist safety. Sharpshooting to reduce white-tailed deer (Odocoileus virginianus; deer) along roads has proven successful in urban situations but has not been evaluated in undeveloped areas. We used a before-after-control-impact (BACI) design to evaluate the use of sharpshooting to reduce DVCs along roads on the uninhabited U.S. Department of Energyâs Savannah River Site, South Carolina, USA, during 2011â2017. We removed 242 deer from 4 treatment roads during 2015 and 2016, with 2-year removal rates per road averaging 5.0 deer/km of road (range 4.0â5.8). We monitored accident rates as DVCs per million vehicle-km traveled (VKT) during annual cycles (MarchâFebruary) following the initial removal and during the 7 months (MarchâSeptember) following removals in spring and the 5 months (OctoberâFebruary) following removals in fall. The response in accident rates varied among the annual cycle, spring, and fall. The BACI effect indicated that removal treatments reduced accident rate by 1.184 DVCs per million VKT (P = 0.081) over the annual cycle and by 1.528 DVCs per million VKT (P = 0.023) following spring removals, but following fall removals we detected no effect (P = 0.541). Relative to the pre-removal accident rate for removal roads, the estimated treatment effect on an annual basis equated to a 39.4% reduction in accidents and during spring equated to a 50.8% reduction in accidents. We conclude that sharpshooting along roads in undeveloped areas can be a viable tool to reduce DVCs and can be useful in areas where population control via hunter harvest is not practical or desirable
HERSCHEL OBSERVATIONS OF EXTRA-ORDINARY SOURCES: H2S AS A PROBE OF DENSE GAS AND POSSIBLY HIDDEN LUMINOSITY TOWARD THE ORION KL HOT CORE
We present Herschel/HIFI observations of the light hydride H2S obtained from the full spectral scan of the Orion Kleinmann-Low nebula (Orion KL) taken as part of the Herschel Observations of EXtra-Ordinary Sources GT (guaranteed time) key program. In total, we observe 52, 24, and 8 unblended or slightly blended features from H2 32S, H2 34S, and H2 33S, respectively. We only analyze emission from the so-called hot core, but emission from the plateau, extended ridge, and/or compact ridge are also detected. Rotation diagrams for ortho and para H2S follow straight lines given the uncertainties and yield T rot = 141 ± 12 K. This indicates H2S is in local thermodynamic equilibrium and is well characterized by a single kinetic temperature or an intense far-IR radiation field is redistributing the population to produce the observed trend. We argue the latter scenario is more probable and find that the most highly excited states (E up gsim 1000 K) are likely populated primarily by radiation pumping. We derive a column density, N tot(H2 32S) = 9.5 ± 1.9 Ă 1017 cmâ2, gas kinetic temperature, T kin = 120 K, and constrain the H2 volume density, gsim 9 Ă 10 7 cmâ3, for the H2S emitting gas. These results point to an H2S origin in markedly dense, heavily embedded gas, possibly in close proximity to a hidden self-luminous source (or sources), which are conceivably responsible for Orion KL's high luminosity. We also derive an H2S ortho/para ratio of 1.7 ± 0.8 and set an upper limit for HDS/H2S of <4.9 Ă 10 â3
High-Resolution Studies of Tropolone in the S 0 and S 1 Electronic States: Isotope Driven Dynamics in the Zero-Point Energy Levels
Rotationally resolved microwave (MW) and ultraviolet (UV) spectra of jet-cooled tropolone have been obtained in S0 and S1 electronic states using Fourier-transform microwave and UV-laser/molecular-beam spectrometers. In the ground electronic state, the MW spectra of all heavy-atom isotopomers including one O18 and four C13 isotopomers were observed in natural abundance. The OD isotopomer was obtained from isotopically enriched samples. The two lowest tunneling states of each isotopomer except O18 have been assigned. The observed inversion splitting for the OD isotopomer is 1523.227(5) MHz. For the asymmetric C13 structures, the magnitudes of tunneling-rotation interactions are found to diminish with decreasing distance between the heavy atom and the tunneling proton. In the limit of closest approach, the 0+ state of O18 was well fitted to an asymmetric rotor Hamiltonian, reflecting significant changes in the tautomerization dynamics. Comparisons of the substituted atom coordinates with theoretical predictions at the MP2/aug-cc-pVTZ level of theory suggest the localized 0+ and 0â wave functions of the heavier isotopes favor the CâOH and C=O forms of tropolone, respectively. The only exception occurs for the C13-OH and C13=O structures which correlate to the 0â and 0+ states, respectively. These preferences reflect kinetic isotope effects as quantitatively verified by the calculated zero-point energy differences between members of the asymmetric atom pairs. From rotationally resolved data of the 0+â0+ and 0ââ0â bands in S1, line-shape fits have yielded Lorentzian linewidths that differ by 12.2(16) MHz over the 19.88(4)cmâ1 interval in S1. The fluorescence decay rates together with previously reported quantum yield data give nonradiative decay rates of 7.7(5)Ă108 and 8.5(5)Ă108sâ1 for the 0+ and 0â levels of the S1 state of tropolone
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