The Twenty-Fifth Amendment and the Establishment of Medical Impairment Panels: Are the Two Safely Compatible?

At least two proposals have been offered by prominent members of the medical community to establish “Medical Impairment Panels” to monitor the health of Presidents of the United States and to facilitate the implementation of relevant Sections of the Twenty-Fifth Amendment. The first discussed in this Article was made by Dr. Herbert Abrams, a now deceased professor of radiology at Stanford University; the second by Dr. Bert Park, a prominent Missouri neurosurgeon. Dr. Abrams and Dr. Park spoke and wrote about their plans frequently over the years. The objective of each proposal was to ensure that the Vice President, the Cabinet, and Congress are informed as to situations when a President might be seriously impaired in terms of carrying out his or her official responsibilities as President of the United States. This Article assesses each proposal in turn

[Review of] August Wilson. Fences

At the turn of the century, playwrights wrestled with realism and wrought a new theater capable of great poetic and symbolic force. It was an exciting time because artists turned their talents to subjects which had never been deemed fit for the stage. The classic requirements of rank and verse were swept aside as audiences learned that even illiterates could make music with their tongues, and that eloquent, serious exploration of the human condition extended well beyond the provinces of kings and queens

Mutuality talk in a family-owned multinational: anthropological categories & critical analyses of corporate ethicizing

This article draws on work carried out as part of a collaboration between an elite business school and a family-owned multinational corporation, concerned with promoting ‘mutuality in business’ as a new frontier of responsible capitalism. While the business school partners treated mutuality as a new principle central to an emergent ethical capitalism, the corporation claimed mutuality as a long-established value unique to their company. Both interpretations foreground a central problem in recent writing on the anthropology of business/corporations: the tension between the claim that economic life is always embedded within a moral calculus, and the shift towards increasingly ethical behaviour among many corporations. Further, recent work in the anthropology of business rejects normative evaluations of corporate ethicizing. When corporations lay claim to ethical renewal, but maintain a commitment to competition and growth, then anthropologists must balance a sympathetic engagement with corporate ethicizing, and critical engagement with growth-based strategie

Synthesis and properties of composites of starch and chemically modified natural rubber

A means is developed for forming polysaccharide-based composites with useful material properties through use of unmodified and chemically modified natural rubber latex (NRL). Starch was used as a model for polysaccharides. The NRL was modified by grafting with dimethylaminoethyl methacrylate (DMAEMA) to form a latex with cationic water-soluble polymeric “hairs” of polyDMAEMA, which should form hydrogen bonds with starch. Starch solutions, containing 20% glycerol as a film-forming aid, and the modified NRL were mixed and films allowed to form. The unmodified latex acted only as filler in the starch films, but with modified NRL, the mechanical properties of the films were significantly altered. The elastic modulus was greatly decreased and strain at break greatly increased. The glass transition temperature increased from –48°C to –32°C, suggesting significant compatibilization. Freeze-fracture TEM micrographs indicate strong interactions between the surface of the modified NRL and starch. The polyDMAEMA chains are more hydrophilic than the starch, and the addition of grafted latex results in a 20° drop of the water contact angle of the formed film, and a 25% increase of the water absorption compared to the native starch; with unmodified NRL, the opposite effect was observed

Highly parallel sparse Cholesky factorization

Several fine grained parallel algorithms were developed and compared to compute the Cholesky factorization of a sparse matrix. The experimental implementations are on the Connection Machine, a distributed memory SIMD machine whose programming model conceptually supplies one processor per data element. In contrast to special purpose algorithms in which the matrix structure conforms to the connection structure of the machine, the focus is on matrices with arbitrary sparsity structure. The most promising algorithm is one whose inner loop performs several dense factorizations simultaneously on a 2-D grid of processors. Virtually any massively parallel dense factorization algorithm can be used as the key subroutine. The sparse code attains execution rates comparable to those of the dense subroutine. Although at present architectural limitations prevent the dense factorization from realizing its potential efficiency, it is concluded that a regular data parallel architecture can be used efficiently to solve arbitrarily structured sparse problems. A performance model is also presented and it is used to analyze the algorithms

The Revenue Maximization Oligopoly Model: Comment

This is a comment on an article on the revenue maximization hypothesis by William BaumolOligopoly; revenue maximization

The influence of macrofaunal burrow spacing and diffusive scaling on sedimentary nitrification and denitrification: An experimental simulation and model approach

The influence of burrow spacing on nitrification and denitrification was simulated experimentally using sediment plugs of different thicknesses immersed in aerated seawater reservoirs. Different plug thicknesses mimic different distances between oxygenated burrow centers and produce similar changes in aerobic–anaerobic reaction balances as a function of diffusive transport scaling. The thicknesses used were roughly equivalent to transport scales (interburrow spacing) that could be produced by burrow abundances of ~400 to 50,000 m-2, depending on burrow lumen radii (e.g., 0.05–1 cm). Following the exposure of anoxic sediment plugs to aerated water, an efficient aerobic nitrification zone was established within the first ~2–3 millimeters of sediment. At pseudo-steady state, the thinnest plug (2 mm) simulating highest burrow density, was entirely oxic and the denitrification rate nil. Denitrification was stimulated in anoxic regions of the thicker plugs (5, 10, and 20 mm) compared to the initial value in experimental sediment. Maximum nitrification rates and the highest denitrification/nitrification ratio between oxic nitrification and adjacent denitrification zones occurred for the intermediate plug thickness of 5 mm. Of the oxic/anoxic composites, the thickest plug showed the least efficient coupling between nitrification/denitrification zones (lowest denitrification/nitrification ratio). Both the thickness of the oxic layer and the total net remineralization of dissolved inorganic N varied inversely with plug thickness. A set of diffusion–reaction models was formulated assuming a range of possible nitrification kinetic functions. All model forms predicted optimal nitrification–denitrification and ammonification–denitrification coupling with relative oxic–anoxic zonation scales comparable to intermediate plug thicknesses (5–6 mm). However, none of the commonly assumed kinetic forms for nitrification could produce the observed NO-3 profiles in detail, implying that natural sediment populations of nitrifiers may be less sensitive to O2 than laboratory strains. Our experimental and model results clearly show that rates of N remineralization and the balance between stimulation/inhibition of denitrification are highly dependent on sedimentary biogenic structure and the particular geometries of irrigated burrow distributions

Coupled anoxic nitrification/manganese reduction in marine sediments

Pore water and solid phase distributions of oxygen, manganese, and nitrogen from hemipelagic and shelf sediments sometimes indicate a close coupling between the manganese and nitrogen redox cycles. Reaction coupling must be sustained in part by biological reworking of Mn-oxide-rich surface sediments into underlying anoxic zones. Surface sediment from Long Island Sound (USA) was used in laboratory experiments to simulate such intermittent natural mixing processes and subsequent reaction evolution. Mixed sediment was incubated anoxically under either diffusively open (plugs) or closed conditions (jars). In closed anoxic incubations, pore water NO3 2 increased regularly to a maximum (up to 17 mM) after one to several days, and was subsequently depleted. Mn21 was produced simultaneously with NO3 2. NO2 2 was also clearly produced and subsequently reduced, with a formation-depletion pattern consistent with coupled nitrificationdenitrification in the anoxic sediment. Manipulative additions of Mn-oxides (5–10 mmol g21 net) demonstrated that net anoxic NO3 2 production correlated directly with initial Mn-oxide content. During initial net NO3 2 production there was no evidence for SO4 22 reduction. A direct correlation was also observed between anoxic nitrification rates and estimated sulfate reduction rates; the larger nitrification rates, the larger the eventual net sulfate reduction rates. Diffusively-open incubations using sediment plugs of four different thicknesses (2, 5, 10 and 20 mm) exposed to anoxic overlying water, also showed net production of pore water NO3 2 (;15–20 mM) despite the absence of NO3 2 in the overlying water for at least five days. In general, higher nitrate concentrations were maintained in the open relative to the closed incubations, due most likely to lower concentrations of dissolved reductants for NO3 2 in the open system. These experiments imply simultaneous coupling between the benthic nitrogen, manganese, and sulfur redox cycles, involving anoxic nitrification and sulfide oxidation to SO4 22. Anoxic nitrate production during Mn reduction indicates that nitrification and denitrification can occur simultaneously in subsurface sediments, without vertical stratification. The existence of anoxic nitrification implies new reaction pathways capable of increasing coupled sedimentary nitrificationdenitrification, particularly in bioturbated or physically mixed deposits