7,504 research outputs found
First Principles for an Effective Rewrite of the Telecommunications Act of 1996
The increasing centrality of the Internet in modern communications, together with massive changes in the landscape of the telecommunications market, have intensified the calls for Congress to overhaul the Telecommunications Act of 1996. In this paper, we analyze this looming legislative challenge by dividing it into two sets of issues: first, issues concerning the proper substance of telecommunications policy reform; and, second, issues concerning the appropriate institutions for carrying out that reform. In Part I, we argue that Congress should require regulators to adhere more closely to (and justify departures from) basic antitrust principles in developing the substance of competition policy. In particular, we explore how those principles would have brought greater predictability and analytical rigor to the FCC's implementation of statutory provisions requiring incumbent telephone providers to lease parts of their networks to competitors. Moreover, we explain how antitrust principles can now inform the current debate over whether to regulate broadband platforms to prevent discrimination against independent providers of applications like voice over Internet protocol. In Part II, we turn to Congress's institutional choices in reforming telecommunications regulation.Despite our advocacy for antitrust-oriented rules of decision, we argue for a continued reliance on the FCC, rather than antitrust courts, as the appropriate institution for superintending the efficient development of competition throughout the industry.Not only does the FCC enjoy specialized expertise in the economics and technology of the telecommunications industry, it also enjoys a distinct advantage over courts in developing and enforcing complicated ,and necessary,prescriptive rules, such as those governing interconnection and its associated intercarrier fees. At the same time, the FCC will increasingly need to refocus its energies from prescriptive regulation to a new emphasis on after-the-fact enforcement and market-monitoring, much like the role played today by the Federal Trade Commission.
Urinary cholesterol: its association with a macromolecular protein- lipid complex
The cholesterol-containing complexes in the urine of normal subjects and patients with diseases accompanied by hyperexcretion of urinary cholesterol were characterized. In normal subjects, the major portion of the recovered urinary cholesterol was eluted in the void volume fractions after gel chromatography on Bio-Gel A-5m; this suggested an association with a macromolecular complex above 5 X 10(6) daltons. A comparable elution pattern was seen in most of the urines of the patients with benign or malignant diseases of the kidneys or the urogenital tract. However, in single patients with hyperexcretion of urinary cholesterol, considerable amounts of cholesterol were detected in the included volume of the column. This was caused by additional excretion of high density lipoproteins or both high and low density lipoproteins in the urine which could be identified in these fractions by agarose electrophoresis and immunodiffusion. These results indicate that the macromolecular complex represents the majority of the recovered urinary cholesterol in normal subjects and in disease states with known hyperexcretion. Macroscopically, the isolated cholesterol- containing complex in the void volume fractions was turbid, and electron microscopy showed lipoprotein-like particles with diameters ranging from 300 to 700 A. The chemical analysis revealed median values of protein (46.0%), triglycerides (16.3%), cholesterol (8.2%), and phospholipids (29.5%) in normal subjects and comparable results in the patients with benign or malignant diseases of the kidney and the urogenital tract. Ethanolamine glycerophospholipids, phosphatidylcholine, sphingomyelin, and phosphatidylserine were the main phospholipid components. After ultracentrifugation in a CsCl gradient, the cholesterol-containing complex was found between densities 1.1 and 1.3 g/ml. By SDS polyacrylamide electrophoresis, up to 17 protein subunits in the molecular weight range of 14,000 to 87,500 were separated. Immunodiffusion studies showed in about 40% precipitin lines against anti-human albumin, but no reactions against anti-human apoHDL and anti-human apoLDL. However, immunodiffusion of the macromolecular complex against anti-liver-specific and anti-kidney- specific lipoproteins revealed single precipitin lines. In conclusion, the isolated cholesterol-containing urinary complex showed many characteristics of membrane-associated protein-lipid particles of the human kidney and even the liver. These proteolipids are the major source of urinary cholesterol in normal and disease states
Research Notes : United States : Response of tolerant and susceptible soybean cultivars to Columbia lance nematode
Columbia lance nematode, CLN [Hoplolaimus columbus Sher], is a migratory endo-and ectoparasite of soybean and commonly causes yield reductions of up to 30% in tolerant cultivars. Complete crop failure may occur on moisture-stressed or susceptible cultivars. First recognized as a major parasite of cotton and soybean in 1967 (Fassultiotis et al., 1968), CLN now infests a large portion of the coastal plain of South Carolina, Georgia, and North Carolina. .pd
Factors Affecting Production and Clarification of Dextran
Author Institution: Departments of Bacteriology and Chemistry, The Ohio State University, Columbus 10
Painting the ideal home: using art to express visions of technologically supported independent living for older people in North East England
This paper describes the investigation of the development of future technological products to support older people in everyday living through the agency of a community art group. Recent research has identified a number of challenges facing designers seeking to use traditional participatory design approaches to gather technology requirements data from older people. Here, a project is described that sought to get a group of older people to think creatively about their needs and desires for technological support through the medium of paint. The artistic expression technique described in this article allowed the identification of issues that had also been found by previous research that used a range of different techniques. This indicates that the approach shows promise, as it allows information to be gathered in an environment that is comfortable and familiar using methods already known by the participants and which they find enjoyable. It provides a complement (or possible alternative) to standard protocols and has the potential benefit of extracting even richer information as the primary task for participants is enjoyable in its own right and is not associated with an interrogative process. Furthermore, it is argued that some of the key risks of traditional approaches are lessened or removed by the naturalistic setting of this approach
Optical conductivity of the one-dimensional dimerized Hubbard model at quarter filling
We investigate the optical conductivity in the Mott insulating phase of the
one-dimensional extended Hubbard model with alternating hopping terms
(dimerization) at quarter band filling. Optical spectra are calculated for the
various parameter regimes using the dynamical density-matrix renormalization
group method. The study of limiting cases allows us to explain the various
structures found numerically in the optical conductivity of this model. Our
calculations show that the dimerization and the nearest-neighbor repulsion
determine the main features of the spectrum. The on-site repulsion plays only a
secondary role. We discuss the consequences of our results for the theory of
the optical conductivity in the Bechgaard salts.Comment: 11 pages and 12 figure
Which are Better Conditioned Meshes Adaptive, Uniform, Locally Refined or Localised
Adaptive, locally refined and locally adjusted meshes are preferred over
uniform meshes for capturing singular or localised solutions. Roughly speaking,
for a given degree of freedom a solution associated with adaptive, locally
refined and locally adjusted meshes is more accurate than the solution given by
uniform meshes. In this work, we answer the question which meshes are better
conditioned. We found, for approximately same degree of freedom (same size of
matrix), it is easier to solve a system of equations associated with an
adaptive mesh.Comment: 4 Page
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