3,102 research outputs found
Production Systems Involving Stocker Cattle and Soft Red Winter Wheat
A three year study at the Livestock and Forestry Research Station near Batesville, Arkansas evaluated production systems involving stocker cattle and soft red winter wheat. Grazing of soft red winter wheat forage from October through February followed by harvesting wheat grain or grazing through April with stocker cattle offers an alternative to conventional farming. Soft red winter wheat, when planted by September 15, produces an ample supply of high-quality forage that supports rapid growth of stocker cattle during October through April. Net income from stocker cattle averaged over 75,000,000 per year if 750,000 acres of wheat are grazed
Quantum data processing and error correction
This paper investigates properties of noisy quantum information channels. We
define a new quantity called {\em coherent information} which measures the
amount of quantum information conveyed in the noisy channel. This quantity can
never be increased by quantum information processing, and it yields a simple
necessary and sufficient condition for the existence of perfect quantum error
correction.Comment: LaTeX, 20 page
Space Trumps Time When Talking About Objects
The nature of the relationship between the concepts of space and time in the human mind is much debated. Some claim that space is primary and that it structures time (cf. Lakoff & Johnson, 1980) while others (cf. Walsh, 2003) maintain no difference in status between them. Using fully immersive virtual reality (VR), we examined the influence of object distance and time of appearance on choice of demonstratives (this and that) to refer to objects. Critically, demonstratives can be used spatially (this/that red triangle) and temporally (this/that month). Experiment 1 showed a pattern of demonstrative usage in VR that is consistent with results found in real‐world studies. Experiments 2, 3, and 4 manipulated both when and where objects appeared, providing scenarios where participants were free to use demonstratives in either a temporal or spatial sense. Although we find evidence for time of presentation affecting object mention, the experiments found that demonstrative choice was affected only by distance. These results support the view that spatial uses of demonstratives are privileged over temporal uses
The Threat of Capital Drain: A Rationale for Public Banks?
This paper yields a rationale for why subsidized public banks may be desirable from a regional perspective in a financially integrated economy. We present a model with credit rationing and heterogeneous regions in which public banks prevent a capital drain from poorer to richer regions by subsidizing local depositors, for example, through a public guarantee. Under some conditions, cooperative banks can perform the same function without any subsidization; however, they may be crowded out by public banks. We also discuss the impact of the political structure on the emergence of public banks in a political-economy setting and the role of interregional mobility
Eficiência do tratamento de sementes de milho sobre larvas de Diabrotica speciosa (Germar, 1824) (Coleoptera: Chrysomelidae).
Dano de larvas de Diabrotica speciosa (Germar, 1824) (Coleoptera: Chrysomelidae) em raízes de milho submetidas a diferentes infestações.
Disorder-induced microscopic magnetic memory
Using coherent x-ray speckle metrology, we have measured the influence of
disorder on major loop return point memory (RPM) and complementary point memory
(CPM) for a series of perpendicular anisotropy Co/Pt multilayer films. In the
low disorder limit, the domain structures show no memory with field cycling--no
RPM and no CPM. With increasing disorder, we observe the onset and the
saturation of both the RPM and the CPM. These results provide the first direct
ensemble-sensitive experimental study of the effects of varying disorder on
microscopic magnetic memory and are compared against the predictions of
existing theories.Comment: 4 pages, 4 figures. Accepted for publication in Physical Review
Letters in Nov. 200
Relativistic Quantum Measurements, Unruh effect and Black Holes
It is shown how the technique of restricted path integrals (RPI) or quantum
corridors (QC) may be applied for the analysis of relativistic measurements.
Then this technique is used to clarify the physical nature of thermal effects
as seen by an accelerated observer in Minkowski space-time (Unruh effect) and
by a far observer in the field of a black hole (Hawking effect). The physical
nature of the "thermal atmosphere" around the observer is analysed in three
cases: a) the Unruh effect, b) an eternal (Kruskal) black hole and c) a black
hole forming in the process of collapse. It is shown that thermal particles are
real only in the case (c). In the case (b) they cannot be distinguished from
real particles but they do not carry away mass of the black hole until some of
these particles are absorbed by the far observer. In the case (a) thermal
particles are virtual.Comment: 24 pages (Latex), 8 EPS figures The text was edited for the new
versio
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