3,996 research outputs found

    Price Expectations in Asset Markets with Futures Contracting

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    Can the introduction of a futures market assist investors in obtaining better price expectations and reduce price bubbles, and is the major determinant of the price bubble the uncertainty of the dividend structure and its effect on noise traders

    Futures Contracting and Dividend Uncertainty in Experimental Asset Markets

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    Prices in experimental asset markets tend to bubble and then crash to dividend value at the end of the asset\u27s useful life. Explanations for this phenomenon are (1) that participants cannot form reliable future price expectations or (2) dividend risk aversion. We report the results of experiments to test these hypotheses. In one experimental series, a futures market is introduced so that participants can obtain information on future share prices. In another series of experiments, the per-period dividend is known with certainty. The futures market treatment had little effect on the character of bubble. The certain dividend treatment had little effect on the character of bubbles with inexperienced traders

    Coherent coupling between surface plasmons and excitons in semiconductor nanocrystals

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    We present an experimental demonstration of strong coupling between a surface plasmon propagating on a planar silver substrate, and the lowest excited state of CdSe nanocrystals. Variable-angle spectroscopic ellipsometry measurements demonstrated the formation of plasmon-exciton mixed states, characterized by a Rabi splitting of \sim 82 meV at room temperature. Such a coherent interaction has the potential for the development of plasmonic non-linear devices, and furthermore, this system is akin to those studied in cavity quantum electrodynamics, thus offering the possibility to study the regime of strong light-matter coupling in semiconductor nanocrystals at easily accessible experimental conditions.Comment: 12 pages, 4 figure

    Nucleation of cracks in a brittle sheet

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    We use molecular dynamics to study the nucleation of cracks in a two dimensional material without pre-existing cracks. We study models with zero and non-zero shear modulus. In both situations the time required for crack formation obeys an Arrhenius law, from which the energy barrier and pre-factor are extracted for different system sizes. For large systems, the characteristic time of rupture is found to decrease with system size, in agreement with classical Weibull theory. In the case of zero shear modulus, the energy opposing rupture is identified with the breakage of a single atomic layer. In the case of non-zero shear modulus, thermally activated fracture can only be studied within a reasonable time at very high strains. In this case the energy barrier involves the stretching of bonds within several layers, accounting for a much higher barrier compared to the zero shear modulus case. This barrier is understood within adiabatic simulations

    Long Range Hops and the Pair Annihilation Reaction A+A->0: Renormalization Group and Simulation

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    A simple example of a non-equilibrium system for which fluctuations are important is a system of particles which diffuse and may annihilate in pairs on contact. The renormalization group can be used to calculate the time dependence of the density of particles, and provides both an exact value for the exponent governing the decay of particles and an epsilon-expansion for the amplitude of this power law. When the diffusion is anomalous, as when the particles perform Levy flights, the critical dimension depends continuously on the control parameter for the Levy distribution. The epsilon-expansion can then become an expansion in a small parameter. We present a renormalization group calculation and compare these results with those of a simulation.Comment: As-published version; two significant errors fixed, two references adde

    Investigation of external refrigeration systems for long term cryogenic storage Final report

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    Data on external refrigeration systems for space storage of cryogens for long period

    Investigation of external refrigeration systems for long-term cryogenic storage

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    Evaluation of cryogenic refrigeration systems for space application

    Radio Spectrum and the Disruptive Clarity of Ronald Coase

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    In the Federal Communications Commission, Ronald Coase exposed deep foundations via normative argument buttressed by astute historical observation. The government controlled scarce frequencies, issuing sharply limited use rights. Spillovers were said to be otherwise endemic. Coase saw that Government limited conflicts by restricting uses; property owners perform an analogous function via the “price system.” The government solution was inefficient unless the net benefits of the alternative property regime were lower. Coase augured that the price system would outperform. His spectrum auction proposal was mocked by communications policy experts, opposed by industry interests, and ridiculed by policy makers. Hence, it took until July 25, 1994 for FCC license sales to commence. Today, some 73 U.S. auctions have been held, 27,484 licenses sold, and 52.6billionpaid.Thereformisatextbookexampleofeconomicpolicysuccess.Herein,weexamineCoasesseminal1959paperontwolevels.First,wenoteitsanalyticalsymmetry,comparingadministrativetomarketmechanismsundertheassumptionofpositivetransactioncosts.ThisfundamentalinsighthaditsbeginninginCoasesacclaimedarticleonthefirm,andcontinuedwithhissubsequenttreatmentofsocialcost.Second,weinvestigatewhyspectrumpolicieshavestoppedwellshortofthepropertyrightsregimethatCoaseadvocated,consideringrentseekingdynamicsandtheemergenceofnewtheorieschallengingCoasespropertyframework.Oneconclusioniseasilyrendered:competitivebiddingisnowthedefaulttoolinwirelesslicenseawards.Byruleofthumb,about52.6 billion paid. The reform is a textbook example of economic policy success. Herein, we examine Coase’s seminal 1959 paper on two levels. First, we note its analytical symmetry, comparing administrative to market mechanisms under the assumption of positive transaction costs. This fundamental insight had its beginning in Coase’s acclaimed article on the firm, and continued with his subsequent treatment of social cost. Second, we investigate why spectrum policies have stopped well short of the property rights regime that Coase advocated, considering rent-seeking dynamics and the emergence of new theories challenging Coase’s property framework. One conclusion is easily rendered: competitive bidding is now the default tool in wireless license awards. By rule of thumb, about 17 billion in U.S. welfare losses have been averted. Not bad for the first 50 years of this, or any, Article appearing in Volume II of the Journal of Law & Economics

    Shiga Toxins: Intracellular Trafficking to the ER Leading to Activation of Host Cell Stress Responses

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    Despite efforts to improve hygenic conditions and regulate food and drinking water safety, the enteric pathogens, Shiga toxin-producing Escherichia coli (STEC) and Shigella dysenteriae serotype 1 remain major public health concerns due to widespread outbreaks and the severity of extra-intestinal diseases they cause, including acute renal failure and central nervous system complications. Shiga toxins are the key virulence factors expressed by these pathogens mediating extra-intestinal disease. Delivery of the toxins to the endoplasmic reticulum (ER) results in host cell protein synthesis inhibition, activation of the ribotoxic stress response, the ER stress response, and in some cases, the induction of apoptosis. Intrinsic and/or extrinsic apoptosis inducing pathways are involved in executing cell death following intoxication. In this review we provide an overview of the current understanding Shiga toxin intracellular trafficking, host cellular responses to the toxin and ER stress-induced apoptosis with an emphasis on recent findings
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