25,000 research outputs found
Direct measurement of the quantum state of the electromagnetic field in a superconducting transmission line
We propose an experimental procedure to directly measure the state of an
electromagnetic field inside a resonator, corresponding to a superconducting
transmission line, coupled to a Cooper-pair box (CPB). The measurement protocol
is based on the use of a dispersive interaction between the field and the CPB,
and the coupling to an external classical field that is tuned to resonance with
either the field or the CPB. We present a numerical simulation that
demonstrates the feasibility of this protocol, which is within reach of present
technology.Comment: Accepted for publication in Physical Review A (Rapid Communication).
4 pages, 2 figure
THE IMPACT OF HEALTH, ENVIRONMENTAL AND SOCIAL ATTRIBUTES OF SALMON CHOICE IN THE UNITED STATES
In recent years, U.S. consumers have increasingly sought information about the health implications of their food purchases, as well as the environmental and social impact of the food production process. While this growing consumer demand has helped facilitate the development of several seafood certification programs, no accessible public or private data shows that U.S. shoppers are willing to pay a premium for certified seafood. To estimate whether a price premium exists for current and forthcoming certifications for wild and farmed salmon producers, and to better understand U.S. consumersâ preferences for salmon, we surveyed a representative sample of 955 shoppers from the United States. We then conducted a conjoint analysis on their willingness to pay for different methods of production (wild or farmed), countries or regions of origin, the Marine Stewardship Councilâs wild seafood âecolabelâ, and hypothetical certifications assuring that the salmon product is associated with fewer health risks, environmental impacts, or negative social issues. Of the factors which affect consumersâ salmon purchasing decisions, the combination of fresh salmonâs method of production and its region of origin is generally a stronger determinant of U.S. salmon shopperâs purchasing decisions than the salmonâs certifications. Consumers strongly favor wild salmon to farmed salmon, prefer salmon from the United States to salmon from other countries, are willing to pay the largest premiums for environmental certifications, and state they are willing to pay the lowest premium for the health and safety certification. Results show that 1) fresh salmon producers and retailers have financial incentives to display social and environmental labels at seafood counters in markets, 2) a price premium for a health and safety certification of farmed salmon would be limited, since salmon consumers are more responsive to negative than positive information related to health issues associated with the salmon that they purchase, and 3) certifying agencies, and all retailers have financial incentives to inform consumers about the benefits and risks of salmon production and consumption, because informed consumers are willing to pay more for certified fresh salmon as well as most types of uncertified fresh salmon.Agricultural and Food Policy, Consumer/Household Economics, Demand and Price Analysis, Food Consumption/Nutrition/Food Safety, Food Security and Poverty, Health Economics and Policy,
A K-Theoretic Proof of Boutet de Monvel's Index Theorem for Boundary Value Problems
We study the C*-closure A of the algebra of all operators of order and class
zero in Boutet de Monvel's calculus on a compact connected manifold X with
non-empty boundary. We find short exact sequences in K-theory
0->K_i(C(X))->K_i(A/K)->K_{1-i}(C_0(T*X'))->0, i= 0,1, which split, where K
denotes the compact ideal and T*X' the cotangent bundle of the interior of X.
Using only simple K-theoretic arguments and the Atiyah-Singer Index Theorem, we
show that the Fredholm index of an elliptic element in A is given as the
composition of the topological index with mapping K_1(A/K)->K_0(C_0(T*X'))
defined above. This relation was first established by Boutet de Monvel by
different methods.Comment: Title slightly changed. Accepted for publication in Journal fuer die
reine und angewandte Mathemati
Galactic Nonlinear Dynamic Model
We develop a model for spiral galaxies based on a nonlinear realization of
the Newtonian dynamics starting from the momentum and mass conservations in the
phase space. The radial solution exhibits a rotation curve in qualitative
accordance with the observational data.Comment: 6 pages, 1 figure. Talk given in the 7th Alexander Friedmann
International Seminar, June 29 to July 5, 2008, Joao Pessoa, PB, Brazi
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