10,869 research outputs found
Assessing the Effectiveness of Farm Supply Cooperatives: A Comparison of Farmer and Manager Viewpoints
This paper reports the results of a survey of attitudes of commercial farmers and supply cooperative managers about agricultural supply cooperatives. Cooperative managers and farmers frequently made significantly different responses to questionnaire statements. With a few expectations, farm size and farmer age did not appear to influence perceptions about supply cooperatives. Whether a farmer was a cooperative member was important in some cases. Lower prices in lieu of easy credit and patronage refunds were found to be acceptable to farmers, but not at the expense of good service. Managers placed great importance on member loyalty to the supply cooperative without regard to price consideration.Agribusiness,
THE CONSEQUENCES OF AN OPEN FIELD BURNING BAN ON THE U.S. KENTUCKY BLUEGRASS SEED INDUSTRY
An econometric model of the U.S. Kentucky bluegrass seed industry in the Pacific Northwest is specified and estimated in order to evaluate the short and long run consequences of yield reductions associated with a ban on open field burning of grass residues. While results differ among regions, model simulations of short run effects of reduced yields attributed to the burning ban indicate price increases for grass seed ranging from 0 to 69 percent and long run effects indicate increased acreage of grass seed production due to producers responses to higher prices.Crop Production/Industries,
Quantum Clock Synchronization: a Multi-Party Protocol
We present a multi-party quantum clock synchronization protocol that utilizes
shared prior entanglement and broadcast of classical information to synchronize
spatially separated clocks. Notably, it is necessary only for any one party to
publish classical information. Consequently, the efficacy of the method is
independent of the relative location of the parties. The suggested protocol is
robust and does not require precise sequencing of procedural steps.Comment: 3 page
Sterilization, State Action, and the Concept ofConsent
A line demarking the propriety of state intervention into the lives of individuals has never been adequately drawn. It is not surprising that such a line is practically nonexistent, from the point of view of legal analysis, when the people subject to intervention are considered mentally retarded. Too infrequently the medical and privacy rights of these individuals go unrecognized and unheeded. There are several factors which collectively account for this
Quantum hierarchic models for information processing
Both classical and quantum computations operate with the registers of bits.
At nanometer scale the quantum fluctuations at the position of a given bit,
say, a quantum dot, not only lead to the decoherence of quantum state of this
bit, but also affect the quantum states of the neighboring bits, and therefore
affect the state of the whole register. That is why the requirement of reliable
separate access to each bit poses the limit on miniaturization, i.e, constrains
the memory capacity and the speed of computation. In the present paper we
suggest an algorithmic way to tackle the problem of constructing reliable and
compact registers of quantum bits. We suggest to access the states of quantum
register hierarchically, descending from the state of the whole register to the
states of its parts. Our method is similar to quantum wavelet transform, and
can be applied to information compression, quantum memory, quantum
computations.Comment: 14 pages, LaTeX, 1 eps figur
Measurements of the methane relaxation times for application to the infrared emission models of the upper atmospheres of outer planets and Titan
The 7.8 micrometer emission from the nu(sub 4) band of methane (CH4) is a regularly observed feature in the stratosphere of all the giant planets and Titan. On Jupiter, enhancements in this emission are associated with the infrared hot spots in the auroral zone. Attempts to model this phenomenon in particular, and to understand the role of methane in general, have been hampered in part by a lack of adequate laboratory measurements of the collisional relaxation times for the nu(sub 3) and nu(sub 4) levels over the appropriate temperature range. To provide this needed data, a series of laboratory experiments were initiated. In the experimental arrangement the nu(sub3) band of methane is pumped at 3.3 micrometers using a pulsed infrared source (Nd:YAG/dye laser system equipped with a wave-length extender). The radiative lifetime of the nu(sub 3) level (approximately 37 ms) is much shorter than the nu(sub 4) lifetime (approximately 390 ms); however, a rapid V-V energy transfer rate ensures that the nu(sub 4) level is substantially populated. The photoacoustic technique is used to acquire relaxation rate information. The experiments are performed using a low-temperature, low-pressure cell. Experimental apparatus and technique are described. In addition some of the experimental difficulties associated with making these measurements are discussed and some preliminary results are presented
Letters to the Editor
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/66363/1/j.1752-7325.1998.tb02993.x.pd
Curiosities of REPINs and RAYTs
Repetitive extragenic palindromic (REP) sequences are a ubiquitous feature of bacterial genomes. Recent work shows that REPs are remnants of a larger mobile genetic element termed a REPIN. REPINs consists of two REP sequences in inverted orientation separated by a spacer region and are thought to be non-autonomous mobile genetic elements that exploit the transposase encoded by REP-Associated tYrosine Transposases (RAYTs). Complimentarity between the two ends of the REPIN suggests that the element forms hairpin structures in single stranded DNA or RNA. In addition to REPINs, other more complex arrangements of REPs have been identified in bacterial genomes, including the genome of the model organism Pseudomonas fluorescens SBW25. Here, we summarize existing knowledge and present new data concerning REPIN diversity. We also consider factors affecting the evolution of REPIN diversity, the ease with which REPINs might be co-opted by host genomes and the consequences of REPIN activity for the structure of bacterial genomes
New Ekpyrotic Cosmology
In this paper, we present a new scenario of the early Universe that contains
a pre big bang Ekpyrotic phase. By combining this with a ghost condensate, the
theory explicitly violates the null energy condition without developing any
ghost-like instabilities. Thus the contracting universe goes through a
non-singular bounce and evolves smoothly into the expanding post big bang
phase. The curvature perturbation acquires a scale-invariant spectrum well
before the bounce in this scenario. It is sourced by the scale-invariant
entropy perturbation engendered by two ekpyrotic scalar fields, a mechanism
recently proposed by Lehners et al. Since the background geometry is
non-singular at all times, the curvature perturbation remains nearly constant
on super horizon scales. It emerges from the bounce unscathed and imprints a
scale-invariant spectrum of density fluctuations in the matter-radiation fluid
at the onset of the hot big bang phase. The ekpyrotic potential can be chosen
so that the spectrum has a ``red'' tilt, in accordance with the recent data
from WMAP. As in the original Ekpyrotic scenario, the model predicts a
negligible gravity wave signal on all observable scales. As such ``New
Ekpyrotic Cosmology" provides a consistent and distinguishable alternative to
inflation to account for the origin of the seeds of large scale structure.Comment: 41 pages, 4 figures. v2: minor corrections, references added. v3:
small modifications in bounce section, references added. v4: version
published in PR
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