9,723 research outputs found
Interpretation of a low-lying excited state of the reaction center of Rb.sphaeroides as a double triplet
The recently observed transient absorption of the lowest excited state of the
special pair P* at 2710 cm-1 is assigned as a singlet which arises from the
coupling of the two lowest triplets from the two dimer halves. INDO
calculations are used to predict its intensity. The analogy of the coupling
mechanism to the trip-doublet spectrum from P+ is shown and the influence of
the double triplet on the Stark effect of P* is investigated.Comment: 10 pages Latex, 1 figure, to be published in Chemical Physics Letters
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A Perplexed Economist Confronts 'too Big to Fail'
This paper examines premises and data underlying the assertion that some financial institutions in the U.S. economy were "too big to fail" and hence warranted government bailout. It traces the merger histories enhancing the dominance of six leading firms in the U. S. banking industry and he sharp increases in the concentration of financial institution assets accompanying that merger wave. Financial institution profits are found to have soared in tandem with rising concentration. The paper advances hypotheses why these phenomena might be related and surveys relevant empirical literature on the relationships between market concentration, interest rates received and charged by banks, and economies of scale in banking.systemic risk, market concentration, mergers, scale economies
Parallel R&D Paths Revisited
This paper revisits the logic of pursuing parallel R&D paths when there is uncertainty as to which approaches will succeed technically and/or economically. Previous findings by Richard Nelson and the present author are reviewed. A further analysis then seeks to determine how sensitive optimal strategies are to parameter variations and the extent to which parallel and series strategies are integrated. It pays to support more approaches, the deeper the stream of benefits is and the lower is the probability of success with a single approach. Higher profits are obtained with combinations of parallel and series strategies, but the differences are small when the number of series trial periods is extended from two to larger numbers. A "dartboard experiment" shows that when uncertainty pertains mainly to outcome values and the distribution of values is skew-distributed, the optimal number of trials is inversely related to the cost per trial.
A note on global warfare in pharmaceutical patenting
This paper revisits the question of whether global welfare is higher under a uniform world-wide system of pharmaceutical product patents or with international rules allowing low-income nations to free-ride on the discoveries of firms in rich nations. Key variables include the extent to which free-riding reduces the discovery of new drugs, the rent potential of rich as compared to poor nations, the ratio of the marginal utility of income in poor as compared to rich nations, and the competitive environment within which R&D decisions are made. Global welfare is found to be higher with free-riding over plausible discovery impairment and income utility combinations, especially when rent-seeking behavior leads to an expansion of R&D outlays exhausting appropriable rents.Pharmaceutical industry ; Patents
Standard Oil as a Technological Innovator
A century ago, in 1911, the U.S. Supreme Court issued its path-breaking decision in the monopolization case against the Standard Oil Companies. Standard pleaded inter alia that its near-monopoly position was the result of superior innovation, citing in particular the Frasch-Burton process for refining the high-sulphur oil found around Lima, Ohio. This paper examines the role of Hermann Frasch in inventing and developing the desulphurization process, showing that Standard failed to recognize his inventive genius when he was its employee and purchased his rights and services only after he had applied the technique in his own Canadian company.
Picosecond pump–probe and polarization techniques in supersonic molecular beams: Measurement of ultrafast vibrational-rotational dephasing and coherence
In the last few years, the time-resolved dynamics of collisionless intramolecular vibrational-energy redistribution (IVR) [1] has been probed [2] using picosecond excitation and fluorescence detection. By this method new information on IVR, coherence and photochemical changes (e.g., trans-cis isomerization) has been obtained. [2,3] However, in a number of cases the (early time) primary step following picosecond excitation could not be resolved simply because the time resolution was limited to ~50ps
Mergers and Innovation in the Pharmaceutical Market
The U.S. pharmaceutical industry has experienced in recent years two dramatic changes: stagnation in the growth of new molecular entities approved for marketing, and a wave of mergers linking inter alia some of the largest companies. This paper explores possible links between these two phenomena and proposes alternative approach to merger policy. It points to the high degree of uncertainty encountered in the discovery and development of new pharmaceutical entities and shows how optimal strategies entail the pursue of parallel research and development paths. Uncertainties afflict both success rates and financial gains contingent upon success. A new model simulating optimal strategies given prevalent market uncertainties is presented. Parallelism can be sustained both within individual companies' R&D programs and across competing companies. The paper points to data showing little parallelism of programs within companies and argues that inter-company mergers jeopardize desirable parallelism across companies.
Possible indicators for low dimensional superconductivity in the quasi-1D carbide Sc3CoC4
The transition metal carbide Sc3CoC4 consists of a quasi-one-dimensional (1D)
structure with [CoC4]_{\inft} polyanionic chains embedded in a scandium
matrix. At ambient temperatures Sc3CoC4 displays metallic behavior. At lower
temperatures, however, charge density wave formation has been observed around
143K which is followed by a structural phase transition at 72K. Below T^onset_c
= 4.5K the polycrystalline sample becomes superconductive. From Hc1(0) and
Hc2(0) values we could estimate the London penetration depth ({\lambda}_L ~=
9750 Angstroem) and the Ginsburg-Landau (GL) coherence length ({\xi}_GL ~= 187
Angstroem). The resulting GL-parameter ({\kappa} ~= 52) classifies Sc3CoC4 as a
type II superconductor. Here we compare the puzzling superconducting features
of Sc3CoC4, such as the unusual temperature dependence i) of the specific heat
anomaly and ii) of the upper critical field H_c2(T) at T_c, and iii) the
magnetic hysteresis curve, with various related low dimensional
superconductors: e.g., the quasi-1D superconductor (SN)_x or the 2D
transition-metal dichalcogenides. Our results identify Sc3CoC4 as a new
candidate for a quasi-1D superconductor.Comment: 4 pages, 5 figure
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