2,572 research outputs found
SUPPLY RESPONSE UNDER THE 1996 FARM ACT AND IMPLICATIONS FOR THE U.S. FIELD CROPS SECTOR
The 1996 Farm Act gives farmers almost complete planting flexibility, allowing producers to respond to price changes to a greater extent than they had under previous legislation. This study measures supply responsiveness for major field crops to changes in their own prices and in prices for competing crops and indicates significant increases in responsiveness. Relative to 1986-90, the percentage increases in the responsiveness of U.S. plantings of major field crops to a 1-percent change in their own prices are wheat (1.2 percent), corn (41.6 percent), soybeans (13.5 percent), and cotton (7.9 percent). In percentage terms, the increases in the responsiveness generally become greater with respect to competing crops' price changes. The 1996 legislation has the least effect on U.S. wheat acreage, whereas the law may lead to an average increase of 2 million acres during 1996-2005 in soybean acreage, a decline of 1-2 million acres in corn acreage, and an increase of 0.7 million acres in cotton acreage. Overall, the effect of the farm legislation on regional production patterns of major field crops appears to be modest. Corn acreage expansion in the Central and Northern Plains, a long-term trend in this important wheat production region, will slow under the 1996 legislation, while soybean acreage expansion in this region will accelerate. The authors used the Policy Analysis System-Economic Research Service (POLYSYS-ERS) model that was jointly developed by USDA's Economic Research Service and the University of Tennessee's Agricultural Policy Analysis Center to estimate the effects of the 1996 legislation.Supply response, major field crops, acreage price elasticities, normal flex acreage (NFA), 1996 farm legislation., Agricultural and Food Policy, Crop Production/Industries,
LMDA Review, volume 8, issue 2
Contents include: Head to Head 1997 Annual Conference, LMDA\u27s Statement of Principle Regarding Rent Lawsuit, A Letter from Canada, My Involvement with Rent, A Dramaturg Changes Hats: Tim Sanford on Career Flexibility, Regional News, The Advocacy Caucus Needs You, Mid-Atlantic/D.C. Metropolitan Regional Report, Dramaturgy Northwest, New York Regional, Regional Vice Presidents.https://soundideas.pugetsound.edu/lmdareview/1016/thumbnail.jp
LMDA Review, volume 8, issue 2
Contents include: Head to Head 1997 Annual Conference, LMDA\u27s Statement of Principle Regarding Rent Lawsuit, A Letter from Canada, My Involvement with Rent, A Dramaturg Changes Hats: Tim Sanford on Career Flexibility, Regional News, The Advocacy Caucus Needs You, Mid-Atlantic/D.C. Metropolitan Regional Report, Dramaturgy Northwest, New York Regional, Regional Vice Presidents.https://soundideas.pugetsound.edu/lmdareview/1016/thumbnail.jp
Proximal, selective, and dynamic interactions between integrin αIIbβ3 and protein tyrosine kinases in living cells
Stable platelet aggregation, adhesion, and spreading during hemostasis are promoted by outside-in αIIbβ3 signals that feature rapid activation of c-Src and Syk, delayed activation of FAK, and cytoskeletal reorganization. To evaluate these αIIbβ3–tyrosine kinase interactions at nanometer proximity in living cells, we monitored bioluminescence resonance energy transfer between GFP and Renilla luciferase chimeras and bimolecular fluorescence complementation between YFP half-molecule chimeras. These techniques revealed that αIIbβ3 interacts with c-Src at the periphery of nonadherent CHO cells. After plating cells on fibrinogen, complexes of αIIbβ3–c-Src, αIIbβ3–Syk, and c-Src–Syk are observed in membrane ruffles and focal complexes, and the interactions involving Syk require Src activity. In contrast, FAK interacts with αIIbβ3 and c-Src, but not with Syk, in focal complexes and adhesions. All of these interactions require the integrin β3 cytoplasmic tail. Thus, αIIbβ3 interacts proximally, if not directly, with tyrosine kinases in a coordinated, selective, and dynamic manner during sequential phases of αIIbβ3 signaling to the actin cytoskeleton
The Whitham Equation as a Model for Surface Water Waves
The Whitham equation was proposed as an alternate model equation for the
simplified description of uni-directional wave motion at the surface of an
inviscid fluid. As the Whitham equation incorporates the full linear dispersion
relation of the water wave problem, it is thought to provide a more faithful
description of shorter waves of small amplitude than traditional long wave
models such as the KdV equation.
In this work, we identify a scaling regime in which the Whitham equation can
be derived from the Hamiltonian theory of surface water waves. The Whitham
equation is integrated numerically, and it is shown that the equation gives a
close approximation of inviscid free surface dynamics as described by the Euler
equations. The performance of the Whitham equation as a model for free surface
dynamics is also compared to two standard free surface models: the KdV and the
BBM equation. It is found that in a wide parameter range of amplitudes and
wavelengths, the Whitham equation performs on par with or better than both the
KdV and BBM equations.Comment: 14 pages, 4 figure
Early-type stars in the young open cluster NGC 2244 and in the Mon OB2 association I. The multiplicity of O-type stars
Aims. We present the results obtained from a long-term spectroscopic campaign
devoted to the multiplicity of O-type stars in the young open cluster NGC2244
and in the Mon OB2 association. Methods. Our spectroscopic monitoring was
performed over several years, allowing us to probe different time-scales. For
each star, several spectral diagnostic tools are applied, in order to search
for line shifts and profile variations. We also measure the projected
rotational velocity and revisit the spectral classification. Results. In our
sample, several stars were previously considered as spectroscopic binaries,
though only a few scattered observations were available. Our results now reveal
a more complex situation. Our study identifies two new spectroscopic binaries
(HD46149 in NGC2244 and HD46573 in MonOB2). The first object is a long-period
double-lined spectroscopic binary, though the exact value of its period remains
uncertain and the second object is classified as an SB1 system with a period of
about 10.67 days but the time series of our observations do not enable us to
derive a unique orbital solution for this system. We also classify another star
as variable in radial velocity (HD46150) and we detect line profile variations
in two rapid rotators (HD46056 and HD46485). Conclusions. This spectroscopic
investigation places a firm lower limit (17%) on the binary fraction of O-stars
in NGC2244 and reveals the lack of short-period O+OB systems in this cluster.
In addition, a comparison of these new results with two other well-studied
clusters (NGC6231 and IC1805) puts forward possible hints of a relation between
stellar density and binarity, which could provide constraints on the theories
about the formation and early evolution of hot stars.Comment: 14 pages, 10 figures, 9 table
The Psychopathologies of Cognitive Capitalism:Part II
An international array of philosophers, critical theorists, media theorists, art historians, architects, and artists discussed the state of the mind and brain under the conditions of contemporary capitalism, in which these cognitive apparati have become the new focus of labouring. Like its predecessor ‘The Psychopathologies of Cognitive Capitalism: Part I’, this conference investigated how the conditions of ‘semiocapitalism’ and ‘cognitive capitalism’ have transformed the conditions of labour – specifically the fact that so much contemporary labour is immaterial, affective, and cognitive – and as a result dĂ©tourned the role of emancipatory politics, art/architecture, and education today. Might these new conditions also have lasting material ramifications for the brain and mind? The conference elaborated upon many of the questions left unattended in Part 1. Questions such as: What is the future of mind in cognitive capitalism? Can a term such as ‘plastic materialism’ describe the substantive changes in neural architectures instigated by this contingent cultural habitus? Is there such a thing as ‘cognitive communism’? Is designed space an agent or platform in the production of subjectivity and is parametrics complicit with its devices? How does artistic research create new emancipatory possibilities in opposition to the overwhelming instrumentalization of the general intellect in semiocapitalism?The Psychopathologies of Cognitive Capitalism: Part II, conference, ICI Berlin, 7–9 March 2013 <https://doi.org/10.25620/e130307
Spectroscopic parameters for silacyclopropynylidene, SiC, from extensive astronomical observations toward CW Leo (IRC +10216) with the Herschel satellite
A molecular line survey has been carried out toward the carbon-rich
asymptotic giant branch star CW Leo employing the HIFI instrument on board of
the Herschel satellite. Numerous features from 480 GHz to beyond 1100 GHz could
be assigned unambiguously to the fairly floppy SiC molecule. However,
predictions from laboratory data exhibited large deviations from the observed
frequencies even after some lower frequency data from this survey were
incorporated into a fit. Therefore, we present a combined fit of all available
laboratory data together with data from radio-astronomical observations.Comment: 7 pages, 1 figure, J. Mol. Spectrosc., appeared; CDMS links corrected
(version 2; current version: 3; may be updated later this year
Heart of Darkness: The Significance of the Zeptobarn Scale for Neutralino Direct Detection
The direct detection of dark matter through its elastic scattering off
nucleons is among the most promising methods for establishing the particle
identity of dark matter. The current bound on the spin-independent scattering
cross section is sigma^SI < 10 zb for dark matter masses m_chi ~ 100 GeV, with
improved sensitivities expected soon. We examine the implications of this
progress for neutralino dark matter. We work in a supersymmetric framework
well-suited to dark matter studies that is simple and transparent, with models
defined in terms of four weak-scale parameters. We first show that robust
constraints on electric dipole moments motivate large sfermion masses mtilde >
1 TeV, effectively decoupling squarks and sleptons from neutralino dark matter
phenomenology. In this case, we find characteristic cross sections in the
narrow range 1 zb 70 GeV. As sfermion masses are
lowered to near their experimental limit mtilde ~ 400 GeV, the upper and lower
limits of this range are extended, but only by factors of around two, and the
lower limit is not significantly altered by relaxing many particle physics
assumptions, varying the strange quark content of the nucleon, including the
effects of galactic small-scale structure, or assuming other components of dark
matter. Experiments are therefore rapidly entering the heart of dark
matter-favored supersymmetry parameter space. If no signal is seen,
supersymmetric models must contain some level of fine-tuning, and we identify
and analyze several possibilities. Barring large cancellations, however, in a
large and generic class of models, if thermal relic neutralinos are a
significant component of dark matter, experiments will discover them as they
probe down to the zeptobarn scale.Comment: 35 pages, 11 figures; v2: references added, figures extended to 2 TeV
neutralino masses, XENON100 results included, published versio
Measuring Slepton Masses and Mixings at the LHC
Flavor physics may help us understand theories beyond the standard model. In
the context of supersymmetry, if we can measure the masses and mixings of
sleptons and squarks, we may learn something about supersymmetry and
supersymmetry breaking. Here we consider a hybrid gauge-gravity supersymmetric
model in which the observed masses and mixings of the standard model leptons
are explained by a U(1) x U(1) flavor symmetry. In the supersymmetric sector,
the charged sleptons have reasonably large flavor mixings, and the lightest is
metastable. As a result, supersymmetric events are characterized not by missing
energy, but by heavy metastable charged particles. Many supersymmetric events
are therefore fully reconstructible, and we can reconstruct most of the charged
sleptons by working up the long supersymmetric decay chains. We obtain
promising results for both masses and mixings, and conclude that, given a
favorable model, precise measurements at the LHC may help shed light not only
on new physics, but also on the standard model flavor parameters.Comment: 24 pages; v2: fixed a typo in our computer program that led to some
miscalculated branching ratios, various clarifications and minor
improvements, conclusions unchanged, published versio
- …