10,211 research outputs found
No purification for two copies of a noisy entangled state
We consider whether two copies of a noisy entangled state can be transformed
into a single copy of greater purity using local operations and classical
communication. We show that it is never possible to achieve such a purification
with certainty when the family of noisy states is twirlable (i.e. when there
exists a local transformation that maps all states into the family, yet leaves
the family itself invariant). This implies that two copies of a Werner state
cannot be deterministically purified. Furthermore, due to the construction of
the proof, it will hold not only in quantum theory, but in any generalised
probabilistic theory. We use this to show that two copies of a noisy PR-box (a
hypothetical device more non-local than is allowed by quantum theory) cannot be
purified.Comment: 4 pages, 2 figure
Creating a Consistent Poverty Measure Over Time Using NAS Procedures: 1996-2005
This paper presents an experimental poverty measure and compares it to the current official measure, now more than 40 years old. The experimental measure is based on an approach, drawn from work by a National Academy of Sciences (NAS) expert Panel, to consistently define basic needs and family resources. The experimental thresholds are based on out-of-pocket spending by families on basic goods and services and are based on an “outflows” concept. The resource measure is based on an “inflows” concept and reflects money coming into the household that is available to meet one’s basic needs. The U.S. Consumer Expenditure Survey serves as the basis for the experimental thresholds and the Current Population Survey Annual Social and Economic Supplement serves as the basis for the resource measure. Results for 1996 to 2005 are reported with trends examined. An important finding is that increases in expenditures for shelter and utilities, captured in the new thresholds, suggest a greater increase in the number of families not able to meet basic needs than is reflected by the official poverty statistics.NAS, Poverty, Consumer Exenditure Survey, Current Population Survey
Thermal expansion of graphite-epoxy between 116 K and 366 K
A Priest laser interferometer was developed to measure the thermal strain of composite laminates. The salient features of this interferometer are that: (1) it operates between 116 K and 366 K; (2) it is easy to operate; (3) minimum specimen preparation is required; (4) coefficients of thermal expansion in the range of 0-5 micro epsilon/K can be measured; and (5) the resolution of thermal strain is on the order of micro epsilon. The thermal response of quasi-isotropic, T300/5208, grahite-epoxy composite material was studied with this interferometer. The study showed that: (1) for the material tested, thermal cycling effects are negligible; (2) variability of thermal response from specimen to specimen may become significant at cryogenic temperatures; and (3) the thermal response of 0.6 cm and 2.5 cm wide specimens are the same above room temperature
Some measurements of the dynamic and static stability of two blunt-nosed, low-fineness- ratio bodies of revolution in free flight at mequal4
Dynamic and static stability of two blunt nosed low fineness ratio bodies of revolution in free flight - ballistic
The impact of high density receptor clusters on VEGF signaling
Vascular endothelial growth factor (VEGF) signaling is involved in the
process of blood vessel development and maintenance. Signaling is initiated by
binding of the bivalent VEGF ligand to the membrane-bound receptors (VEGFR),
which in turn stimulates receptor dimerization. Herein, we discuss experimental
evidence that VEGF receptors localize in caveloae and other regions of the
plasma membrane, and for other receptors, it has been shown that receptor
clustering has an impact on dimerization and thus also on signaling. Overall,
receptor clustering is part of a complex ecosystem of interactions and how
receptor clustering impacts dimerization is not well understood. To address
these questions, we have formulated the simplest possible model. We have
postulated the existence of a single high affinity region in the cell membrane,
which acts as a transient trap for receptors. We have defined an ODE model by
introducing high- and low-density receptor variables and introduce the
corresponding reactions from a realistic model of VEGF signal initiation.
Finally, we use the model to investigate the relation between the degree of
VEGFR concentration, ligand availability, and signaling. In conclusion, our
simulation results provide a deeper understanding of the role of receptor
clustering in cell signaling.Comment: In Proceedings HSB 2013, arXiv:1308.572
Development of a Priest interferometer for measurement of the thermal expansion of a graphite epoxy in the temperature range 116-366 K
The thermal expansion behavior of graphite epoxy laminates between 116 and 366 degrees Kelvin was investigated using as implementation of the Priest interferometer concept. The design, construction and use of the interferometer along with the experimental results it was used to generate are described. The experimental program consisted of 25 tests on 25.4 mm and 6.35 mm wide, 8 ply pi/4 quasi-isotropic T300-5208 graphite/epoxy specimens and 3 tests on a 25.4 mm wide unidirectional specimen. Experimental results are presented for all tests along with a discussion of the interferometer's limitations and some possible improvements in its design
FREE-FLIGHT MEASUREMENTS OF STATIC AND DYNAMIC STABILITY OF MODELS OF THE PROJECT MERCURY RE-ENTRY CAPSULE AT MACH NUMBERS 3 AND 9.5
Static & dynamic stability of mercury reentry capsule scale models at mach 3 & 9.
Eelgrass in Estuarine Research Reserves Along the East Coast, USA
Eelgrass, Zostera marina L., is a submerged marine vascular plant that provides the basic structure of an extensive and important estuarine and coastal ecosystem. Currently, eelgrass populations around the world are declining dramatically due primarily to two causes: human pollution and a disease. The extensive loss of eelgrass threatens major alterations to the coastal environment and to the waterfowl and fish that depend on these plant communities. However, the eelgrass declines represent natural experiments that provide and opportunity to investigate a disease\u27s impact on an ecosystem, the characteristics of pollution-related declines, and finally, how declines from both causes can be diminished or mitigated
PRODUCTION AND FINANCIAL IMPACTS OF THE ADOPTION OF BOVINE SOMATOTROPIN ON U.S. DAIRY FARMS
Production and financial impacts of recombinant bovine somatotropin (rbST) adoption are assessed using a survey of U.S. dairy operations and a model that corrects for self-selection bias. A substantial increase in milk production per cow is associated with rbST adoption, but large estimated financial impacts are not statistically significant. Substantial variation in the net returns of rbST adopters may be related to the management-intensive nature of rbST.Livestock Production/Industries,
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