6,510 research outputs found
SEVENTEEN FAMOUS ECONOMISTS WEIGH IN ON COPYRIGHT: THE ROLE OF THEORY, EMPIRICS, AND NETWORK EFFECTS
In 2002, seventeen economists including five Nobel Laureates presented an amicus curiae brief discussing the economics of copyright extension in support of the petitioners in Eldred v. Ashcroft. The economists’ amicus brief was unusual in several respects, not least in that it brought together a group of economists almost as notable for its diversity of opinion (spanning the ideological spectrum from Kenneth Arrow to Milton Friedman) as for its academic distinction. When such a distinguished and broad panel of economists readers would have every reason to believe that the arguments set forth in this document are sound down to the smallest details. Yet this is not the case. Scholars in the fields of law and economics will continue to address the economics of copyright duration in the foreseeable future, so it is important that they understand the imperfections in the economists’ brief. This Article provides a counterweight to the amicus brief, identifying some points the economists ignored, clarifying some discussions they did not quite get right, and providing data that runs counter to some assumptions they made.Eldred, coypright, sonny bono, lessig
Is the Endangered Species Act Endangering Species?
We develop theory and present a suite of theoretically consistent empirical measures to explore the extent to which market intervention inadvertently alters resource allocation in a sequentialmove principal/agent game. We showcase our approach empirically by exploring the extent to which the U.S. Endangered Species Act has altered land development patterns. We report evidence indicating significant acceleration of development directly after each of several events deemed likely to raise fears among owners of habitat land. Our preferred estimate suggests an overall acceleration of land development by roughly one year. We also find from complementary hedonic regression models that habitat parcels declined in value when the habitat map was published, which is consistent with our estimates of the degree of preemption. These results have clear implications for policymakers, who continue to discuss alternative regulatory frameworks for species preservation. More generally, our modeling strategies can be widely applied -- from any particular economic environment that has a sequential-move nature to the narrower case of the political economy of regulation.
Trace element and isotope geochemistry of Cretaceous-Tertiary boundary sediments: identification of extra-terrestrial and volcanic components
Trace element and stable isotope analyses were performed on a series of sediment samples crossing the Cretaceous-Tertiary (K-T) boundary from critical sections at Aumaya and Sopelano, Spain. The aim is to possibly distinguish extraterrestrial vs. volcanic or authigenic concentration of platinum group and other elements in K-T boundary transitional sediments. These sediments also have been shown to contain evidence for step-wise extinction of several groups of marine invertebrates, associated with negative oxygen and carbon isotope excursions occurring during the last million years of the Cretaceous. These isotope excursions have been interpreted to indicate major changes in ocean thermal regime, circulation, and ecosystems that may be related to multiple events during latest Cretaceous time. Results to date on the petrographic and geochemical analyses of the Late Cretaceous and Early Paleocene sediments indicate that diagenesis has obviously affected the trace element geochemistry and stable isotope compositions at Zumaya. Mineralogical and geochemical analysis of K-T boundary sediments at Zumaya suggest that a substantial fraction of anomalous trace elements in the boundary marl are present in specific mineral phases. Platinum and nickel grains perhaps represent the first direct evidence of siderophile-rich minerals at the boundary. The presence of spinels and Ni-rich particles as inclusions in aluminosilicate spherules from Zumaya suggests an original, non-diagenetic origin for the spherules. Similar spherules from southern Spain (Caravaca), show a strong marine authigenic overprint. This research represents a new approach in trying to directly identify the sedimentary mineral components that are responsible for the trace element concentrations associated with the K-T boundary
Curve fits of predicted inviscid stagnation-point radiative heating rates, cooling factors, and shock standoff distances for hyperbolic earth entry
Curve-fit formulas are presented for the stagnation-point radiative heating rate, cooling factor, and shock standoff distance for inviscid flow over blunt bodies at conditions corresponding to high-speed earth entry. The data which were curve fitted were calculated by using a technique which utilizes a one-strip integral method and a detailed nongray radiation model to generate a radiatively coupled flow-field solution for air in chemical and local thermodynamic equilibrium. The range of free-stream parameters considered were altitudes from about 55 to 70 km and velocities from about 11 to 16 km.sec. Spherical bodies with nose radii from 30 to 450 cm and elliptical bodies with major-to-minor axis ratios of 2, 4, and 6 were treated. Powerlaw formulas are proposed and a least-squares logarithmic fit is used to evaluate the constants. It is shown that the data can be described in this manner with an average deviation of about 3 percent (or less) and a maximum deviation of about 10 percent (or less). The curve-fit formulas provide an effective and economic means for making preliminary design studies for situations involving high-speed earth entry
MR Spectroscopic Imaging of Peripheral Zone in Prostate Cancer Using a 3T MRI Scanner: Endorectal versus External Phased Array Coils.
Magnetic resonance spectroscopic imaging (MRSI) detects alterations in major prostate metabolites, such as citrate (Cit), creatine (Cr), and choline (Ch). We evaluated the sensitivity and accuracy of three-dimensional MRSI of prostate using an endorectal compared to an external phased array "receive" coil on a 3T MRI scanner. Eighteen patients with prostate cancer (PCa) who underwent endorectal MR imaging and proton (1H) MRSI were included in this study. Immediately after the endorectal MRSI scan, the PCa patients were scanned with the external phased array coil. The endorectal coil-detected metabolite ratio [(Ch+Cr)/Cit] was significantly higher in cancer locations (1.667 ± 0.663) compared to non-cancer locations (0.978 ± 0.420) (P < 0.001). Similarly, for the external phased array, the ratio was significantly higher in cancer locations (1.070 ± 0.525) compared to non-cancer locations (0.521 ± 0.310) (P < 0.001). The sensitivity and accuracy of cancer detection were 81% and 78% using the endorectal 'receive' coil, and 69% and 75%, respectively using the external phased array 'receive' coil
Cost-Effective Use of Silver Dressings for the Treatment of Hard-to-Heal Chronic Venous Leg Ulcers
Aim
To estimate the cost-effectiveness of silver dressings using a health economic model based on time-to-wound-healing in hard-to-heal chronic venous leg ulcers (VLUs).
Background
Chronic venous ulceration affects 1–3% of the adult population and typically has a protracted course of healing, resulting in considerable costs to the healthcare system. The pathogenesis of VLUs includes excessive and prolonged inflammation which is often related to critical colonisation and early infection. The use of silver dressings to control this bioburden and improve wound healing rates remains controversial.
Methods
A decision tree was constructed to evaluate the cost-effectiveness of treatment with silver compared with non-silver dressings for four weeks in a primary care setting. The outcomes: ‘Healed ulcer’, ‘Healing ulcer’ or ‘No improvement’ were developed, reflecting the relative reduction in ulcer area from baseline to four weeks of treatment. A data set from a recent meta-analysis, based on four RCTs, was applied to the model.
Results
Treatment with silver dressings for an initial four weeks was found to give a total cost saving (£141.57) compared with treatment with non-silver dressings. In addition, patients treated with silver dressings had a faster wound closure compared with those who had been treated with non-silver dressings.
Conclusion
The use of silver dressings improves healing time and can lead to overall cost savings. These results can be used to guide healthcare decision makers in evaluating the economic aspects of treatment with silver dressings in hard-to-heal chronic VLUs
Proposal for the determination of nuclear masses by high-precision spectroscopy of Rydberg states
The theoretical treatment of Rydberg states in one-electron ions is
facilitated by the virtual absence of the nuclear-size correction, and
fundamental constants like the Rydberg constant may be in the reach of planned
high-precision spectroscopic experiments. The dominant nuclear effect that
shifts transition energies among Rydberg states therefore is due to the nuclear
mass. As a consequence, spectroscopic measurements of Rydberg transitions can
be used in order to precisely deduce nuclear masses. A possible application of
this approach to the hydrogen and deuterium, and hydrogen-like lithium and
carbon is explored in detail. In order to complete the analysis, numerical and
analytic calculations of the quantum electrodynamic (QED) self-energy remainder
function for states with principal quantum number n=5,...,8 and with angular
momentum L=n-1 and L=n-2 are described (j = L +/- 1/2).Comment: 21 pages; LaTe
Pterodactyl: Trade Study for an Integrated Control System Design of a Mechanically Deployable Entry Vehicle
This paper presents the trade study method used to evaluate and downselect from a set of guidance and control (G&C) system designs for a mechanically Deployable Entry Vehicle (DEV). The Pterodactyl project was prompted by the challenge to develop an effective G&C system for a vehicle without a backshell, which is the case for DEVs. For the DEV, the project assumed a specific aeroshell geometry pertaining to an Adaptable, Deployable Entry and Placement Technology (ADEPT) vehicle, which was successfully developed by NASAs Space Technology Mission Directorate (STMD) prior to this study. The Pterodactyl project designed three different entry G&C systems for precision targeting. This paper details the Figures of Merit (FOMs) and metrics used during the course of the projects G&C system assessment. The relative importance of the FOMs was determined from the Analytic Hierarchy Process (AHP), which was used to develop weights that were combined with quantitative design metrics and engineering judgement to rank the G&C systems against one another. This systematic method takes into consideration the projects input while simultaneously reducing unintentional judgement bias and ultimately was used to select a single G&C design for the project to pursue in the next design phase
Contemplative Science: An Insider's Prospectus
This chapter describes the potential far‐reaching consequences of contemplative higher education for the fields of science and medicine
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