2,541 research outputs found
THE IMPACT OF SALES CHANGES ON AGRIBUSINESS PAYROLLS
Agribusiness firms face substantial market risk associated with variations in farm production, output and input prices, exchange rates, and other factors. Some of the risk faced by agribusiness is passed through to the employees of the firm and to the communities where the firms are located, as employment levels are changed in response to these variations. An econometric analysis of the transmission of sales changes into payroll changes was performed for a sample of Georgia agribusiness firms. Transmission elasticities were found to be affected by firm type, size, age, and by the degree of use part-time employees.Agribusiness, Employment stability, Labor, Labor and Human Capital, Agribusiness,
Real-time dynamics in spin-1/2 chains with adaptive time-dependent DMRG
We investigate the influence of different interaction strengths and
dimerizations on the magnetization transport in antiferromagnetic spin-1/2
XXZ-chains. We focus on the real-time evolution of the inhomogeneous initial
state with all spins pointing up along the z axis in the left half and down in
the right half of the chain, using the adaptive time-dependent density-matrix
renormalization group (adaptive t-DMRG). We find on time-scales accessible to
us ballistic magnetization transport for small Sz-Sz-interaction and arbitrary
dimerization, but almost no transport for stronger Sz-Sz-interaction, with a
sharp crossover at Jz=1. At Jz=1 results indicate superdiffusive transport.
Additionally, we perform a detailed analysis of the error made by the adaptive
time-dependent DMRG using the fact that the evolution in the XX-model is known
exactly. We find that the error at small times is dominated by the error made
by the Trotter decomposition, whereas for longer times the DMRG truncation
error becomes the most important, with a very sharp crossover at some "runaway"
time.Comment: 13 pages, 20 figure
How valid is the arthroscopic diagnosis of cartilage lesions? Results of an opinion survey among highly experienced arthroscopic surgeons
The Low-Latitude Ionosphere/Thermosphere Enhancements in Density (LLITED) Mission
The Low-Latitude Ionosphere/Thermosphere Enhancements in Density (LLITED) CubeSat mission is a NASA funded HTIDs project. It is a 3-year grant with two 1.5U CubeSats with an estimated delivery in the spring of 2020 and a 1- year on-orbit mission life. Each CubeSat will host a miniature ionization gauge space instrument (MIGSI), planar ion probe (PIP), and GPS radio occultation sensor (CTECS-A). The mission is to provide both ionosphere and thermosphere measurements related to the Equatorial Ionization Anomaly (EIA) and the Equatorial Temperature and Wind Anomaly (ETWA). The EIA and ETWA are two of the dominant ionosphere/thermosphere interactions on the low-latitude duskside. While the EIA has been extensively studied both observationally and with modeling, the ETWA is less well known since observations are infrequent due to a lack of suitably instrumented spacecraft (s/c) at appropriate altitudes. LLITED will, for the first time, provide coincident high-resolution measurements of the duskside ionosphere/thermosphere at lower altitudes that will characterize and improve our understanding of the ETWA, provide insight into the coupling physics between the ETWA and EIA, and increase our knowledge of the duskside dynamics that may influence space weather. The following paper reviews the science mission and concepts and then provides the current status of the LLITED hardware
The chemical composition of red giants in 47 Tucanae I: Fundamental parameters and chemical abundance patterns
Context: The study of chemical abundance patterns in globular clusters is of
key importance to constrain the different candidates for intra-cluster
pollution of light elements. Aims: We aim at deriving accurate abundances for a
large range of elements in the globular cluster 47 Tucanae (NGC 104) to add new
constraints to the pollution scenarios for this particular cluster, expanding
the range of previously derived element abundances. Methods: Using tailored 1D
LTE atmospheric models together with a combination of equivalent width
measurements, LTE, and NLTE synthesis we derive stellar parameters and element
abundances from high-resolution, high signal-to-noise spectra of 13 red giant
stars near the tip of the RGB. Results: We derive abundances of a total 27
elements (O, Na, Mg, Al, Si, Ca, Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Y, Zr,
Mo, Ru, Ba, La, Ce, Pr, Nd, Eu, Dy). Departures from LTE were taken into
account for Na, Al and Ba. We find a mean [Fe/H] = and
in good agreement with previous studies. The
remaining elements show good agreement with the literature, but the inclusion
of NLTE for Al has a significant impact on the behaviour of this key element.
Conclusions: We confirm the presence of an Na-O anti-correlation in 47 Tucanae
found by several other works. Our NLTE analysis of Al shifts the [Al/Fe] to
lower values, indicating that this may be overestimated in earlier works. No
evidence for an intrinsic variation is found in any of the remaining elements.Comment: 22 pages, 16 figures. Accepted for publication in A&
Motion of condensates in non-Markovian zero-range dynamics
Condensation transition in a non-Markovian zero-range process is studied in
one and higher dimensions. In the mean-field approximation, corresponding to
infinite range hopping, the model exhibits condensation with a stationary
condensate, as in the Markovian case, but with a modified phase diagram. In the
case of nearest-neighbor hopping, the condensate is found to drift by a
"slinky" motion from one site to the next. The mechanism of the drift is
explored numerically in detail. A modified model with nearest-neighbor hopping
which allows exact calculation of the steady state is introduced. The steady
state of this model is found to be a product measure, and the condensate is
stationary.Comment: 31 pages, 9 figure
Desisting from Prescription Drug Abuse: An Application of Growth Models to Rx Opioid Users
Modern desistance research has examined many facets of desistance, in terms of theoretical predictors of desistance and recidivism, and in terms of differing types of offending. Though predicting desistance from illegal drug use is among these topics, no research to date has examined the predictors of desisting from prescription opioid abuse. This study uses longitudinal data from 318 prescription opioid users to analyze the effects of various predictors of desistance on declining nonmedical prescription opioid use, with an emphasis on gender differences among participants. Results indicate that theoretical and demographic characteristics correspond with differing rates of decline and further vary by gender
Chronic anti-Thy-1 nephritis is aggravated in the nonclipped but not in the clipped kidney of Goldblatt hypertensive rats
Chronic anti-Thy-1 nephritis is aggravated in the nonclipped but not in the clipped kidney of Goldblatt hypertensive rats.BackgroundWe have previously shown that renovascular hypertension does not inhibit healing of the acute Thy-1 nephritis. To test whether a chronic model of the Thy-1 nephritis is more susceptible to high blood pressure, the repetitive hit model was evaluated in rats with 2-kidney, 1-clip Goldblatt hypertension.MethodsSix weeks after initiation of 2-kidney, 1-clip hypertension, chronic Thy-1 glomerulonephritis was induced in hypertensive rats by four consecutive injections of rabbit antiserum in weekly intervals. Renal structure and function were examined two weeks after the last injection. Glomerular binding of rabbit IgG as well as expression of transforming growth factor-beta (TGF-β), α-smooth muscle actin (α-SMA) and cyclooxygenase (COX)-1 and -2 were evaluated by Western blotting.ResultsSimilar glomerular deposition of rabbit IgG was detected in normotensive rats and in both kidneys of Goldblatt hypertensive rats indicating similar delivery and binding of the heterologous antibody. Induction of the repetitive Thy-1 model significantly enhanced glomerular damage in the nonclipped kidney and increased albuminuria. Surprisingly, no glomerular damage developed in the clipped kidney of nephritic hypertensive rats. In contrast, increased glomerular volume and increased expression of TGF-β, α-SMA as well as COX-1 and COX-2 were found in normotensive nephritic rats and in both kidneys of nephritic hypertensive rats.ConclusionGlomerular and tubulointerstitial damage of the chronic Thy-1 model is dramatically enhanced in the nonclipped kidneys of Goldblatt hypertensive rats. In contrast, the clipped kidney is completely protected from this immunological injury despite similar activation of glomerular cells, induction of TGF-β, COX-1 and COX-2 and glomerular hypertrophy
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