7,459 research outputs found
The Transmission of Price Trends from Consumers to Producers and Tests of Market Power
This study examines the competitiveness of four Canadian agricultural industries (eggs, milk, chicken and turkey) using a general equilibrium farm to retail pricing model developed by Wohlgenant (1989). The model generates retail and farm pricing equations that are estimated using maximum likelihood developed by Johansen (1992). The results indicate that in all cases, long-run constant returns is rejected, indicating market power within the Canadian retail to farm marketing sector. The model also finds more cointegrating vectors than predicted by theory, also inconsistent with competitive markets. Results are based on commercial disappearance as a proxy for consumer demand and therefore confounding between uncompetitive markets and quality differences may be indicated. Less ambiguous results would be obtained if consumer expenditures rather than commercial disappearance data were available. Still, results are rather emphatic in rejection of competitive markets in food markets in Canada. More competitive markets are indicated in the United States using similar methods.Market power, food processing, cointegration, Agribusiness, Agricultural and Food Policy, Consumer/Household Economics, Demand and Price Analysis, Food Consumption/Nutrition/Food Safety, D41, L66, Q13,
Anion receptor chemistry: highlights from 2011 and 2012
This review covers advances in anion complexation in the years 2011 and 2012. The review covers both organic and inorganic systems and also highlights the applications to which anion receptors can be applied such as self-assembly and molecular architecture, sensing, catalysis and anion transport
Aminoglycoside-Induced Phosphatidylserine Externalization in Sensory Hair Cells Is Regionally Restricted, Rapid, and Reversible
The aminophospholipid phosphatidylserine (PS) is normally restricted to the inner leaflet of the plasma membrane. During certain cellular processes, including apoptosis, PS translocates to the outer leaflet and can be labeled with externally applied annexin V, a calcium-dependent PS-binding protein. In mouse cochlear cultures, annexin V labeling reveals that the aminoglycoside antibiotic neomycin induces rapid PS externalization, specifically on the apical surface of hair cells. PS externalization is observed within ~75 s of neomycin perfusion, first on the hair bundle and then on membrane blebs forming around the apical surface. Whole-cell capacitance also increases significantly within minutes of neomycin application, indicating that blebbing is accompanied by membrane addition to the hair cell surface. PS externalization and membrane blebbing can, nonetheless, occur independently. Pretreating hair cells with calcium chelators, a procedure that blocks mechanotransduction, or overexpressing a phosphatidylinositol 4,5-biphosphate (PIP2)-binding pleckstrin homology domain, can reduce neomycin-induced PS externalization, suggesting that neomycin enters hair cells via transduction channels, clusters PIP2, and thereby activates lipid scrambling. The effects of short-term neomycin treatment are reversible. After neomycin washout, PS is no longer detected on the apical surface, apical membrane blebs disappear, and surface-bound annexin V is internalized, distributing throughout the supranuclear cytoplasm of the hair cell. Hair cells can therefore repair, and recover from, neomycin-induced surface damage. Hair cells lacking myosin VI, a minus-end directed actin-based motor implicated in endocytosis, can also recover from brief neomycin treatment. Internalized annexin V, however, remains below the apical surface, thereby pinpointing a critical role for myosin VI in the transport of endocytosed material away from the periphery of the hair cell
The nonlinear Bernstein-Schr\"odinger equation in Economics
In this paper we relate the Equilibrium Assignment Problem (EAP), which is
underlying in several economics models, to a system of nonlinear equations that
we call the "nonlinear Bernstein-Schr\"odinger system", which is well-known in
the linear case, but whose nonlinear extension does not seem to have been
studied. We apply this connection to derive an existence result for the EAP,
and an efficient computational method.Comment: 8 pages, submitted to Lecture Notes in Computer Scienc
Highly effective yet simple transmembrane anion transporters based upon ortho-phenylenediamine bis-ureas
Simple, highly fluorinated receptors are shown to function as highly effective transmembrane anion antiporters with the most active transporters rivalling the transport efficacy of natural anion transporter prodigiosin for bicarbonate
Azimuthal Asymmetry of Direct Photons in High Energy Nuclear Collisions
We show that a sizeable azimuthal asymmetry, characterized by a coefficient
v_2, is to be expected for direct photons produced in non-central high energy
nuclear collisions. This signal is generated by photons radiated by jets
interacting with the surrounding hot plasma. The anisotropy is out of phase by
an angle with respect to that associated with the elliptic anisotropy
of hadrons, leading to negative values of v_2. Such an asymmetry, if observed,
could be a signature for the presence of a quark gluon plasma and would
establish the importance of jet-plasma interactions as a source of
electromagnetic radiation.Comment: New title. Final versio
Wind-Tunnel Investigation of the Opening Characteristics, Drag, and Stability of Several Hemispherical Parachutes
An investigation has been conducted to determine the opening characteristics of several hemispherical parachutes and to study the influence of the parachute design variables on these opening characteristics. The effects of design variables on the drag and stability characteristics of the parachutes were also evaluated. The tests were made in the Langley 20-foot free-spinning tunnel and in the Langley 300 MPH 7 by 10-foot tunnel
A shear spectral sum rule in a non-conformal gravity dual
A sum rule which relates a stress-energy tensor correlator to thermodynamic
functions is examined within the context of a simple non-conformal gravity
dual. Such a sum rule was previously derived using AdS/CFT for conformal
Supersymmetric Yang-Mills theory, but we show that it does
not generalize to the non-conformal theory under consideration. We provide a
generalized sum rule and numerically verify its validity. A useful byproduct of
the calculation is the computation of the spectral density in a strongly
coupled non-conformal theory. Qualitative features of the spectral densities
and implications for lattice measurements of transport coefficients are
discussed.Comment: 13 pages, 3 figures. v5: Typos in Eq. (60) fixed. v4: References
added, matches published version. v3: Minor typographical corrections. v2:
References and some discussion in Appendix A have been added; conclusions
unchange
Typical properties of optimal growth in the Von Neumann expanding model for large random economies
We calculate the optimal solutions of the fully heterogeneous Von Neumann
expansion problem with processes and goods in the limit .
This model provides an elementary description of the growth of a production
economy in the long run. The system turns from a contracting to an expanding
phase as increases beyond . The solution is characterized by a universal
behavior, independent of the parameters of the disorder statistics. Associating
technological innovation to an increase of , we find that while such an
increase has a large positive impact on long term growth when , its
effect on technologically advanced economies () is very weak.Comment: 8 pages, 1 figur
High momentum lepton pairs from jet-plasma interactions
We discuss the emission of high momentum lepton pairs (p_T>4 GeV) with low
invariant masses (M << p_T) in central Au+Au collisions at RHIC
(\sqrt{s_{NN}}=200 GeV). The spectra of dileptons produced through interactions
of quark and antiquark jets with the quark-gluon plasma (QGP) have been
calculated. Annihilation and Compton scattering processes, as well as processes
benefitting from collinear enhancement, including Landau-Pomeranchuk-Migdal
(LPM) effects, are calculated and convolved with a one dimensional hydrodynamic
expansion. The jet-induced contributions are compared to thermal dilepton
emission and Drell-Yan processes, and are found to dominate around p_T=4 GeV.Comment: Parallel talk given at QM2006, Shanghai November 2006. 4 pages, 3
figure
- …