10,726 research outputs found

    INFORMATION IMPACTS AND DETERMINANTS OF INFORMATION SELECTION: AN EXPERIMENTAL APPROACH

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    Laboratory experimentation was used to assess the impacts of information disclosure in imperfect markets. A dual oligopoly market structure was designed with contract information disclosed to subjects under three treatments: no, partial, and full disclosure. Regression analysis revealed some increase in selling price with full information disclosure, but no discernable effects on negotiated prices with partial disclosure. Alternative specifications showed large traders earning significantly lower profits, and information on large traders significantly beneficial to both buyers and sellers. Probit analysis of information selection determinants revealed no significant economic content in trader requests for information under partial disclosure.Marketing,

    The genealogy of judgement: towards a deep history of academic freedom

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    The classical conception of academic freedom associated with Wilhelm von Humboldt and the rise of the modern university has a quite specific cultural foundation that centres on the controversial mental faculty of 'judgement'. This article traces the roots of 'judgement' back to the Protestant Reformation, through its heyday as the signature feature of German idealism, and to its gradual loss of salience as both a philosophical and a psychological concept. This trajectory has been accompanied by a general shrinking in the scope of academic freedom from the promulgation of world-views to the offering of expert opinion

    Deer reduce habitat quality for a woodland songbird: evidence from settlement patterns, demographic parameters, and body condition.

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    Understanding avian responses to ungulate-induced habitat modification is important because deer populations are increasing across much of temperate Europe and North America. Our experimental study examined whether habitat quality for Blackcaps (Sylvia atricapilla) in young woodland in eastern England was affected by deer, by comparing Blackcap behavior, abundance, and condition between paired plots (half of each pair protected from deer). The vegetation in each pair of plots was the same age. The Blackcap is an ideal model species for testing effects of deer on avian habitat quality because it is dependent on dense understory vegetation and is abundant throughout much of Europe. We compared timing of settlement, abundance, age structure (second-year vs. after-second-year), and phenotypic quality (measured as a body condition index, body mass divided by tarsus length) between experimental and control plots. We used point counts to examine Blackcap distribution, and standardized mist netting to collect demographic and biometric data. Incidence of singing Blackcaps was higher in nonbrowsed than in browsed plots, and singing males were recorded in nonbrowsed plots earlier in the season, indicating earlier and preferential territory establishment. Most Blackcaps, both males and females, were captured in vegetation prior to canopy closure (2–4 years of regrowth). Body condition was superior for male Blackcaps captured in nonbrowsed plots; for second-year males this was most marked in vegetation prior to canopy closure. We conclude that deer browsing in young woodland can alter habitat quality for understory-dependent species, with potential consequences for individual fitness and population productivity beyond the more obvious effects on population density

    EFFECT OF CONTRACT DISCLOSURE ON PRICE: RAILROAD GRAIN CONTRACTING IN THE PLAINS

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    The Staggers Rail Act of 1980 granted railroads freedom to establish rates and enter into confidential contracts with grain shippers. Recent legislation (1986) required that certain contract terms be disclosed. This study shows rail rates in the Plains region commenced an upward trend after implementation of the disclosure policy. Results suggest contract disclosure and increased reliance on posted tariffs facilitated rate coordination within the oligopolistic railroad industry.Public Economics,

    ALMA observations of 99 GHz free-free and H40α\alpha line emission from star formation in the centre of NGC 253

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    We present Atacama Large Millimeter/submillimeter Array observations of 99.02 GHz free-free and H40α\alpha emission from the centre of the nearby starburst galaxy NGC 253. We calculate electron temperatures of 3700-4500 K for the photoionized gas, which agrees with previous measurements. We measure a photoionizing photon production rate of (3.2±0.2)×1053(3.2\pm0.2)\times10^{53} s−1^{-1} and a star formation rate of 1.73±0.121.73\pm0.12 M⊙_\odot yr−1^{-1} within the central 20×\times10 arcsec, which fall within the broad range of measurements from previous millimetre and radio observations but which are better constrained. We also demonstrate that the dust opacities are ~3 dex higher than inferred from previous near-infrared data, which illustrates the benefits of using millimetre star formation tracers in very dusty sources.Comment: 5 pages, 3 figures, accepted for publication in MNRAS Letter

    Report on Design and Construction of the Axial Flow Pump Test Facility

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    In studies concerned with the application of pumps to underwater jet propulsion, it has been pointed out that cavitation may be avoided or suppressed by enclosing the pump (or propeller) in a suitably shaped shroud. The advantages of avoiding cavitation are clear; namely, the elimination of much noise, damage and vibration in addition to increasing the allowable speed. However, a general discussion of the various flow processes which lead to cavitation is not yet possible. For propellers, cavitation is observed in helical trailing vortices and also on the blade surface proper, but for other types of propulsion systems, notably pump jets, neither is the location known nor the cause completely understood. Roughly speaking, cavitation will occur when local pressures reach the vapor pressure of the flowing liquid, however, the magnitude and location of these local underpressures depend upon the complete history of the flow as it passes through the machine. Consequently, minimum pressures may occur in the free stream in some cases, or upon the blade surface itself in others. Thus, in order to study cavitation phenomena, it is first necessary to investigate the detailed behavior of the flow. Apart from cavitation and noise, there are also other problems of considerable importance in rotating axial flow machinery. Among the most prominent of these is the behavior of the fluid in the boundary layer near the rotor and stator blade tips, and the off design performance in the region of stalled flow. These questions are of great concern in the design and application of axial flow compressors and, as long as compressibility effects are negligible, they may be investigated just as well in water as in air. Moreover, inasmuch as the kinematic viscosity of air to that of water is thirteen to one {at atmospheric conditions), machines can be made to operate in water at the same Reynolds numbers as in air at much reduced speeds, sizes, power consumptions and blade stresses, and as a result of these facts the installation and operational costs are also lower than for the comparative air machine. The cost of the blading of a compressor is a major portion of the total cost of the machine and, therefore, the high expense of installing different blade designs for research purposes prohibits extensive investigation. In 1951 the Hydrodynamics Laboratory at the California Institute of Technology developed a method of making inexpensive precision lead-alloy blades for axial flow pump test impellers. As a result of this work, interest was expressed by personnel of the Naval Ordnance Test Station and staff members of the Institute in the application of such blade-making techniques for air compressor and underwater propulsion research. It was estimated that blades could be made for about one-eighth of the cost per blade row of those in a research compressor currently operating at the Institute. This attractive estimate lead to the consideration of an axial flow compressor run in water as a pump at relatively low speeds so that research on cavitating and noncavitating flow could be done without prohibitive expense. Under this contract, NOrd 9612, an axial flow pump with its enclosed circuit was constructed and preliminary tests on a single stage of blading were run by the first week of November, 1952. It is the purpose of this report to describe the installation and show its usefulness for research

    LOCATION OF A MIXALCO PRODUCTION FACILITY WITH RESPECT TO ECONOMIC VIABILITY

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    Monte-Carlo simulation modeling is used to perform a feasibility study of alternative locations for a MixAlco production facility. Net present value distributions will be ranked within feasible risk aversion boundaries. If MixAlco is a profitable investment, it would have a major impact on the fuel oxygenate and gasoline markets.Resource /Energy Economics and Policy,
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