18,233 research outputs found
DETERMINANTS OF COW-CALF PAIR PRICES
Cow-calf prices are determined by interaction of many factors. At a particular auction, cow-calf pair prices often had a range of 75% of the mean price. This variability suggests that producers need to be informed regarding cow-calf price determinants. This study uses auction data during 1993 to estimate price differentials associated with cow-calf pair characteristics using a hedonic model. Cow breed, age, health, conditions, horns, frame, and whether the cow had been bred back were significant price determinants. Calf weight, health, and frame had significant price impacts. Highest prices were paid for pens containing 9-12 pairs of young Angus, dehorned, bred back, healthy cows with heavy healthy calves.Demand and Price Analysis,
FUTURES-BASED PRICE FORECASTS FOR AGRICULTURAL PRODUCERS AND BUSINESSES
The forecasting accuracy of five competing naïve and futures-based localized cash price forecasts is determined. The third-week's price each month from 1987-96 is forecasted from several vantage points. Commodities examine include those relevant to Midwest producers: the major grains, slaughter steers, slaughter hogs, several classes of feeder cattle, cull cows, and sows. Relative forecasting accuracy across forecast method is compared using regression models of forecast error. The traditional forecast method deferred futures plus historical basis has the greatest accuracy- even for cull cows. Adding complexity to forecasts, such as including regression models to capture nonlinear bases or biases in futures markets, does not improve accuracy.Demand and Price Analysis,
Delignification of Ponderosa Pine Sawdust and Bark by Peroxyacetic Treatments
The purpose of this study was to determine effectiveness of peroxyacetic acid in improving the digestibility of highly lignified fibrous materials such as ponderosa pine sawdust and bark. Peroxyacetic acid is used as a delignifying agent in the making of paper from tree fibers
Feedback in a cavity QED system for control of quantum beats
Conditional measurements on the undriven mode of a two-mode cavity QED system
prepare a coherent superposition of ground states which generate quantum beats.
The continuous system drive induces decoherence through the phase interruptions
from Rayleigh scattering, which manifests as a decrease of the beat amplitude
and an increase of the frequency of oscillation. We report recent experiments
that implement a simple feedback mechanism to protect the quantum beat. We
continuously drive the system until a photon is detected, heralding the
presence of a coherent superposition. We then turn off the drive and let the
superposition evolve in the dark, protecting it against decoherence. At a later
time we reinstate the drive to measure the amplitude, phase, and frequency of
the beats. The amplitude can increase by more than fifty percent, while the
frequency is unchanged by the feedback.Comment: 13 pages, 5 figures, ICAP 2012 23rd International Conference on
Atomic Physic
SEASAT: A satellite scatterometer illumination times of selected in situ sites
A list of times that the SEASAT A Satellite Scatterometer (SASS) illuminated from directly above or directly abeam, selected surface sites where in situ winds were measured is provided. The list is ordered by the Greenwich Mean Time (GMT) of the midpoint of the illumination period (hit time) for a given surface site. The site identification, the orbit number and the direction from the subtrack in which the truth lies are provided. The accuracy of these times depends in part upon the ascending node times, which are estimated to be within +.1 sec, and on the illumination time relative to the ascending node, which is estimated to be within +6 seconds. The uncertainties in the times provided were judged to be sufficiently small to allow efficient and accurate extraction of SASS and in situ data at the selected surface sites. The list contains approximately six thousand hit times from 61 geographically dispersed sites
Molecular Model of the Contractile Ring
We present a model for the actin contractile ring of adherent animal cells.
The model suggests that the actin concentration within the ring and
consequently the power that the ring exerts both increase during contraction.
We demonstrate the crucial role of actin polymerization and depolymerization
throughout cytokinesis, and the dominance of viscous dissipation in the
dynamics. The physical origin of two phases in cytokinesis dynamics ("biphasic
cytokinesis") follows from a limitation on the actin density. The model is
consistent with a wide range of measurements of the midzone of dividing animal
cells.Comment: PACS numbers: 87.16.Ka, 87.16.Ac
http://www.ncbi.nlm.nih.gov/pubmed/16197254
http://www.weizmann.ac.il/complex/tlusty/papers/PhysRevLett2005.pd
Noninvasive ¹³C-octanoic acid breath test shows delayed gastric emptying in patients with amyotrophic lateral sclerosis
Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disorder characterized by progressive loss of motor neurons. However, ALS has been recognized to also involve non-motor systems. Subclinical involvement of the autonomic system in ALS has been described. The recently developed C-13-octanoic acid breath test allows the noninvasive measurement of gastric emptying. With this new technique we investigated 18 patients with ALS and 14 healthy volunteers. None of the patients had diabetes mellitus or other disorders known to cause autonomic dysfunction. The participants received a solid standard test meal labeled with C-13-octanoic acid. Breath samples were taken at 15-min intervals for 5 h and were analyzed for (CO2)-C-13 by isotope selective nondispersive infrared spectrometry. Gastric emptying peak time (t(peak)) and emptying half time (t(1/2)) were determined. All healthy volunteers displayed normal gastric emptying with a mean emptying t(1/2) of 138 +/- 34 (range 68-172) min. Gastric emptying was delayed (t(1/2) > 160 min) in 15 of 18 patients with ALS. Emptying t(1/2) in ALS patients was 218 +/- 48 (range 126-278) min (p < 0.001). These results are compatible with autonomic involvement in patients with ALS, causing delayed gastric emptying of solids and encouraging the theory that ALS is a multisystem disease rather than a disease of the motor neurons only
Valuing Fed Cattle Using Objective Tenderness Measures
Beef tenderness is critical in consumer satisfaction with beef steak products. Current fed cattle valuation systems do not differentiate carcasses based upon tenderness variation. However, considerable research indicates consumers are willing to pay more for tender relative to tough beef steak. This article develops a tenderness-augmentation to current fed cattle grid pricing systems. Using a large set of actual carcasses, we determine that a tenderness-augmented price grid would reorder fed cattle value by on average nearly $5.00/cwt dressed relative to current valuation methods. Substantial opportunity is present to improve beef tenderness through new price signals to producers.beef quality, meat tenderness, cattle value, cattle price, Agribusiness, Farm Management, Food Consumption/Nutrition/Food Safety, Livestock Production/Industries, Q11, Q13, M31,
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