cssi/SciSciGPT-SciSciNet huggingface dataset:
The Role of General Relativity in Astronomy: Retrospect and Prospect

My last attendance at a meeting of the International Astronomical Union was forty-four years ago when it met in Paris in 1935. I do not doubt that my being asked to give an invited discourse at this meeting is a personal courtesy extended to me by your distinguished President recalling, perhaps, the years when he and I were colleagues together at the University of Chicago. I am aware that associated with my absence from these meetings for nearly half a century is the fact that during most of this period - if not all of it - my interests, at different times, have been outside whatever may have been the prevailing trends in the mainstream of astronomy. I am afraid that on this account, the point of view I shall present - retrospectively and prospectively - will not be in conformity with the trends currently prevailing. I must therefore begin by asking for your patience and for your forbearance. Dr. Blaauw, when he invited me to give one of the three discourses at this meeting, suggested that in selecting a topic I might wish to take into account the fact that this year is the centennial of Einstein’s birth. The subject of my discourse is in accordance with that suggestion.
A Lattice-Based Public-Key Cryptosystem

Ajtai recently found a random class of lattices of integer points for which he could prove the following worst-case/average-case equivalence result: If there is a probabilistic polynomial time algorithm which finds a short vector in a random lattice from the class, then there is also a probabilistic polynomial time algorithm which solves several problems related to the shortest lattice vector problem (SVP) in any n-dimensional lattice. Ajtai and Dwork then designed a public-key cryptosystem which is provably secure unless the worst case of a version of the SVP can be solved in probabilistic polynomial time. However, their cryptosystem suffers from massive data expansion because it encrypts data bit-by-bit. Here we present a public-key cryptosystem based on similar ideas, but with much less data expansion.
Investment and market power

Abstract This paper argues that the degree of market power within an industry is an important determinant of interindustry differences in investment behavior A neoclassical investment model is analyzed to show that market power is positively associated with capital stock flexibility The intuition for the result is that firms adjust their stocks and investment plans quickly in response to new conditions so as to capture the rents asssociated with their market power
On some integrals over the product of three Legendre functions

The definite integrals \(\int_{-1}^{1}(1-x^{2})^{(\nu-1)/2}[P_{\nu}(x)]^{3}\, \mathrm{d}x\), \(\int_{-1}^{1}(1-x^{2})^{(\nu-1)/2} [P_{\nu}(x)]^{2}P_{\nu}(-x)\, \mathrm{d}x\), \(\int_{-1}^{1}x(1-x^{2})^{(\nu-1)/2}[P_{\nu+1}(x)]^{3}\,\mathrm{d}x\), and \(\int_{-1}^{1}x(1-x^{2})^{(\nu-1)/2} [P_{\nu+1}(x)]^{2}P_{\nu +1}(-x)\,\mathrm{d}x \) are evaluated in closed form, where Pν is the Legendre function of degree ν, and \(\operatorname{Re}\nu>-1\). Special cases of these formulae are related to certain integrals over elliptic integrals that have arithmetic interest.
Breakdown of Stability of Motion in Superquadratic Potentials

Based on the KAM theory, investigation of the equation of motion of a classical particle in a one-dimensional superquadratic potential well, under the influence of an external time-periodic forcing, raised a hope that all the solutions are bounded. Indeed, due to the superquadraticity of the potential the frequency of oscillations of the solutions in the system tends to infinity as the amplitude increases. Therefore, because of this relationship between the frequency and the amplitude, intuitively one might expect that all resonances that could cause the accumulation of energy would be destroyed, and thus all solutions would stay bounded for all time. More formally, according to Moser's twist theorem, this could mean the existence of invariant tubes in the extended phase space and therefore would result in the boundedness of the solutions.
The geometry at infinity of a hyperbolic Riemann surface of infinite type

We study geodesics on planar Riemann surfaces of infinite type having a single infinite end. Of particular interest is the class of geodesics that go out the infinite end in a most efficient manner. We investigate properties of these geodesics and relate them to the structure of the boundary of a Dirichlet polygon for a Fuchsian group representing the surface.
The amino acid sequence of Clostridium butyricum ferredoxin.

Abstract The amino acid sequence of Clostridium butyricum ferredoxin, determined by the application of conventional methods of sequence determination primarily to the S-β-aminoethyl protein, was found to be: Ala-Phe-Val-Ile-Asn-Asp-Ser-Cys-Val-Ser- Cys-Gly-Ala-Cys-Ala-Gly-Glu-Cys-Pro-Val-Ser-Ala-Ile-Thr-Gln-Gly-Asp-Thr-Gln- Phe-Val-Ile-Asp-Ala-Asp-Thr-Cys-Ile-Asp-Cys-Gly-Asn-Cys-Ala-Asn-Val-Cys-Pro- Val-Gly-Ala-Pro-Asn-Gln-Glu. This sequence differs in nine positions from that of Clostridium pasteurianum ferredoxin. The positions of the cysteine and proline residues are invariant in these two species, as is the sequence including residues 30–52.
On the mechanism of the silicon-tethered reductive Pauson-Khand reaction

Abstract The reductive Pauson–Khand reaction (PKR) of tethered vinyl silanes likely proceeds as usual to the bicyclopentenones 2 , but rapid loss of the allylic silane initiates a fragmentation process culminating in propargylic carbon reduction. Damp nitrile solvents are crucial for efficient reaction, and under dry conditions additional products are obtained including dimerized cyclopentadienones and 5-(1-amino-alkylidine) cyclopentenes. Solvent incorporated enones likely arise from enolate attack on a cobalt coordinated nitrile. A unified reaction mechanism is proposed. The first example of a PKR with an allyloxy ethynylsilane is also reported.
Multivariate Time‐Series Analysis With Categorical and Continuous Variables in an Lstr Model

. We develop a methodology for multivariate time-series analysis when our time-series has components that are both continuous and categorical. Our specific contribution is a logistic smooth-transition regression (LSTR) model, the transition variable of which is related to a categorical time-series (LSTR-C). This methodology is necessary for series that exhibit nonlinear behaviour dependent on a categorical time-series. The estimation procedure is investigated both with simulation and an economic time-series. We obtain superior or equivalent model fits as compared with another smooth-transition regression model. Furthermore, even when the nonlinear behaviour of the time-series is dependent on a continuous time-series, we propose a simplification of the modelling process, which is the automatic formulation of the transition variable from the categorical time-series. We are able to capture this nonlinear dependence on a continuous time-series by using regression theory for categorical time-series.
Ammonia borane hydrogen release in ionic liquids.

The rate and extent of H2-release from ammonia borane (AB), a promising, high-capacity hydrogen storage material, was found to be enhanced in ionic-liquid solutions. For example, AB reactions in 1-butyl-3-methylimidazolium chloride (bmimCl) (50:50-wt %) exhibited no induction period and released 1.0 H2-equiv in 67 min and 2.2 H2-equiv in 330 min at 85 °C, whereas comparable solid-state AB reactions at 85 °C had a 180 min induction period and required 360 min to release ∼0.8 H2-equiv, with the release of only another ∼0.1 H2-equiv at longer times. Significant rate enhancements for the ionic-liquid mixtures were obtained with only moderate increases in temperature, with, for example, a 50:50-wt % AB/bmimCl mixture releasing 1.0 H2-equiv in 5 min and 2.2 H2-equiv in only 20 min at 110 °C. Increasing the AB/bmimCl ratio to 80:20 still gave enhanced H2-release rates compared to the solid-state, and produced a system that achieved 11.4 materials-weight percent H2-release. Solid-state and solution 11B NMR studie...
Non-unified gaugino masses in supersymmetric missing partner models with hypercolor☆

Abstract The gaugino mass relations m 3 g 3 2 = m 2 g 2 2 = m 1 g 1 2 are considered to be robust signals for supersymmetric grand unification. In this letter, we point out that these relations may be significantly modified in an interesting class of models which solve the doublet-triplet splitting problem using a missing partner mechanism together with a strong hypercolor gauge group. The observation of non-unified gaugino masses, together with unified sfermion masses, provides a distinctive signature for these models.
In situ monitoring of damage in SiC/SiC composites using acousto-ultrasonics

Abstract Acousto-ultrasonics (AU) is a nondestructive evaluation (NDE) technique that utilizes two ultrasonic transducers to interrogate the condition of a test specimen. The sending transducer introduces an ultrasonic pulse at a point on the surface of the specimen while a receiving transducer detects the signal after it has passed through the material. The aim of the method is to correlate certain empirical parameters of the detected waveform to characteristics of the material between the two transducers. The waveform parameter of interest is the attenuation due to internal damping for which information is being garnered from the frequency domain. Here, the three parameters utilized to indirectly quantify the attenuation are the ultrasonic decay rate, the mean square value of the power spectrum, and the centroid of the power spectrum. The sensitivity for each of these AU parameters was assessed with respect to the damage state of two types of SiC/SiC ceramic matrix composites (CMC). The two composite systems both had Hi-Nicalon™ fibers with a carbon interface but had different matrix compositions that led to considerable differences in damage accumulation. Load/unload/reload tensile tests were performed and in situ AU measurements were made over the entire stress range. After analyzing the AU parameters, the overall sensitivity of the AU technique to material change or damage was quantified and shown to correlate well with the observed damage mechanisms for both material systems. In addition, the AU response was shown to be dependent on the stress state of the composites. This stress dependent behavior was observed while unloading the specimens from the maximum stress, thereby, maintaining a constant damage state.
STRONGLY DONATING SCORPIONATE LIGANDS

The success of tris(pyrazolyl)borates has inspired the development of new scorpionate ligands that are based on other donor groups. These include borate ligands with thioimidazolyl, selenoimidazolyl, phosphine and N-heterocyclic carbene donors, ligands that provide a facial array of [S3], [Se3], [P3], and [C3] donors, respectively. These ligands are all more strongly donating than the tris(pyrazolyl)borates, with tris(carbene)borate ligands having the greatest donor strength. Despite the design similarities, strongly donating scorpionates differ in their topology and flexibility, donor properties and degradation pathways. The structural and electronic properties of these ligands are contrasted and related to their chemistry, particularly that of the transition metals. Bidentate congeners of all these ligands are also known and are briefly covered. The ability of strongly donating scorpionate ligands to stabilize metal ligand multiple bonds in late transition metal complexes is also briefly discussed.
Consistent model of magnetism in ferropnictides

As the pnictide superconductors have metallic ground states, the Heisenberg model has not been successful in describing the magnetic behaviour. But the addition of a biquadratic interaction term to the usual Heisenberg Hamiltonian leads to a description of many experimental observations.
Creation of Stable Multipartite Entangled States in Spin Chains with Defects

We show how defects in a spin chain described by the XXZ model may be used to generate entangled states, such as Bell and W states, and how to maintain them with high fidelity. We also discuss, in the presence of several excitations, how the anisotropy of the system may be combined with defects to effectively assist in the creation of the desired states.
The Importance of the Nitrous Oxide Pathway to NOx in Lean-Premixed Combustion

This study addresses the importance of the different chemical pathways responible for NO x formation in lean-premixed combustion, and especially the role of the nitrous oxide pathway relative to the traditional Zeldovich pathway. NO x formation is modeled and computed over a range of operating conditions for the lean-premixed primary zone of gas turbine engine combustors. The primary zone, of uniform fuel-air ratio, is modeled as a micromixed well-stirred reactor, representing the flame zone, followed by a series of plug flow reactors, representing the postflame zone. The fuel is methane. The fuel-air equivalence ratio is varied from 0.5 to 0.7. The chemical reactor model permits study of the three pathways by which NO x forms, which are the Zeldovich, nitrous oxide, and prompt pathways. Modeling is also performed for the well-stirred reactor alone. Three recently published, complete chemical kinetic mechanisms for the C1−C2 hydrocarbon oxidation and the NO x formation are applied and compared. Verification of the model is based on the comparison of its NO x output to experimental results published for atmospheric pressure jet-stirred reactors and for a 10 atm. porous-plate burner. Good agreement between the modeled results and the measurements is obtained for most of the jet-stirred reactor operating range. For the porous-plate burner, the model shows agreement to the NO x measurements within a factor of two, with close agreement occurring at the leanest and coolest cases examined. For lean-premixed combustion at gas turbine engine conditions, the nitrous oxide pathway is found to be important, though the Zeldovich pathway cannot be neglected. The prompt pathway, however, contributes small-to-negligible NO x . Whenever the NO x emission is in the 15 to 30 ppmv (15 percent O 2 , dry) range, the nitrous oxide pathway is predicted to contribute 40 to 45 percent of the NO x for high-pressure engines (30 atm), and 20 to 35 percent of the NO x for intermediate pressure engines (10 atm). For conditions producing NO x of less than 10 ppmv (15 percent O 2 , dry), the nitrous oxide contribution increases steeply and approaches 100 percent. For lean-premixed combustion in the atmospheric pressure jet-stirred reactors, different behavior is found. All three pathways contribute; none can be dismissed. No universal behavior is found for the pressure dependence of the NO x . It does appear, however, that lean-premixed combustors operated in the vicinity of 10 atm have a relatively weak pressure dependence, whereas combustors operated in the vicinity of 30 atm have an approximately square root pressure dependence of the NO x
Dendritic cell nediated inhibition of lentiviral infection

Background Lentiviral entry to quiescent lymphocytes represents a ‘time bomb’ waiting for cellular activation to spread infection. In order to undergo immune activation T cells interact with dendritic cells presenting peptide:MHC complexes ‘sampling’ them to look for agonist peptides and receiving survival signals from self peptides. This makes the dendritic cell:T cell interaction an ideal checkpoint to contain lentiviral infection of quiescent lypmhocytes.
A global fit of LEP/SLC data with light superpartners

We find that re-analyzing the LEP/SLC data with light superpartners and low αs(mZ2) ⋍ 0.112 yields a better fit to the data than the Standard Model, giving a satisfactory description of the Rb measurement, and a better fit to ALR. A large body of low energy (q2 ⪡ mZ2) data and analyses provide compeling evidence for αs(mZ2) ⋍ 0.112. Global fits to LEP/SLC data in the Standard Model, however, converge on a value of αs(mZ2) ⋍ 0.126. Recently it has become increasingly clear that these should be viewed as incompatible rather than values that can be averaged. We investigate the possibility that new physics is causing the LEP high value. To this end we have conducted a global analysis of LEP/SLC data in the Standard Model and also in the Minimal Supersymmetric Standard Model. Several predictions could confirm (or rule out) the results of this paper: light chargino and stop, top decays into stop and neutralino, large Rb, large ALR, and a higher MW. We briefly discuss the implications of low αs for more fundamental high-scale supersymmetric theories.
Use of precatalysts greatly facilitate palladium-catalyzed alkynylations in batch and continuous-flow conditions

A general and efficient condition for palladium-catalyzed Heck alkynylation in batch was developed using a novel precatalyst. In addition, the first general and efficient continuous-flow protocol for the coupling of alkynes with aryl bromides in the absence of copper was reported.
After the First Amendment Fails: The Newsmen's Privilege Hearings of the 1970s

The recent jailing and threatened jailing of journalists seeking to protect confidential sources has prompted Congress to reopen debate on legislation providing journalists with a statutory right of confidentiality. This article explores debates over eighty-six newsmen's privilege bills introduced in the House of Representatives between 1972 and 1975, after the Supreme Court of the United States decided Branzburg v. Hayes. The article identifies the primary policy differences, motives and perspectives of key advocates, and reasons for the failure of any bill to become law. It examines arguments for and against a privilege and the four major areas of policy disputes: the range of protections from absolutist to qualified protections, the problem of defining “journalist,” protection of only confidential information or all newsgathering material, and whether a federal privilege statute should apply to state proceedings. In doing so, the article provides historical context to contemporary legislative debates.
A multilateral Bailey lemma and multiple Andrews–Gordon identities

A multilateral Bailey lemma is proved, and multiple analogues of the Rogers–Ramanujan identities and Euler’s pentagonal theorem are constructed as applications. The extreme cases of the Andrews–Gordon identities are also generalized using the multilateral Bailey lemma where their final form are written in terms of determinants of theta functions.
A Massive Warm Baryonic Halo in the Coma Cluster

Several deep PSPC observations of the Coma Cluster reveal a very large scale halo of soft X-ray emission, substantially in excess of the well-known radiation from the hot intracluster medium. The excess emission, previously reported in the central region of the cluster using lower sensitivity Extreme Ultraviolet Explorer (EUVE) and ROSAT data, is now evident out to a radius of 2.6 Mpc, demonstrating that the soft excess radiation from clusters is a phenomenon of cosmological significance. The X-ray spectrum at these large radii cannot be modeled nonthermally but is consistent with the original scenario of thermal emission from warm gas at approx. 10(exp 6) K. The mass of the warm gas is on par with that of the hot X-ray-emitting plasma and significantly more massive if the warm gas resides in low-density filamentary structures. Thus, the data lend vital support to current theories of cosmic evolution, which predict that at low redshift approx. 30%-40% of the baryons reside in warm filaments converging at clusters of galaxies.
How is macro news transmitted to exchange rates

Abstract Macro news can affect currency prices directly and indirectly via order flow. Past research shows that the direct effects of scheduled macro news account for less than 10% of daily price variance. This paper shows that the arrival of macro news can account for more than 30% of daily price variance. Two features of our analysis account for this finding: (1) We consider the broad spectrum of macro news items that market participants observe, not just scheduled announcements. (2) We allow the arrival of news to affect prices indirectly via its impact on the volatility of order flow. Our analysis shows that order flow variations contribute more to currency price dynamics following the arrival of public macro news than at other times. This is not consistent with news effects being common knowledge that is impounded in price directly. Roughly two-thirds of the total effect of macro news on the DM/$ exchange rate is transmitted via order flow.
Nonlocal exchange correlation in screened-exchange density functional methods

We present a systematic study on the exchange-correlationeffects in screened-exchange local density functional method. Toinvestigate the effects of the screened-exchange potential in the bandgap correction, we have compared the exchange-correlation potential termin the sX-LDA formalism with the self-energy term in the GWapproximation. It is found that the band gap correction of the sX-LDAmethod primarily comes from the downshift of valence band states,resulting from the enhancement of bonding and the increase of ionizationenergy. The band gap correction in the GW method, on the contrary, comesin large part from the increase of theconduction band energies. We alsostudied the effects of the screened-exchange potential in the totalenergy by investigating the exchange-correlation hole in comparison withquantum Monte Carlo calculations. When the Thomas-Fermi screening isused, the sX-LDA method overestimates (underestimates) theexchange-correlation hole in short (long) range. From theexchange-correlation energy analysis we found that the LDA method yieldsbetter absolute total energy than sX-LDA method.
Total synthesis of TMC-95A and -B via a new reaction leading to Z-enamides. Some preliminary findings as to SAR.

A full account of the total syntheses of proteasome inhibitors TMC-95A and -B is provided. A key feature of the syntheses involved installation of a cis-propenylamide moiety by a thermal rearrangement of an α-silylallyl amide. The scope and mechanism of the enamide-forming reaction are discussed. Also provided are some preliminary results from SAR studies. It was found that simplified analogues can retain the full potency of proteasome inhibition.
Quasi-isometric co-Hopficity of non-uniform lattices in rank-one semi-simple Lie groups

We prove that if G is a non-uniform lattice in a rank-one semi- simple Lie group 6 Isom(H 2 ) then G is quasi-isometrically co-Hopf. This means that every quasi-isometric embedding G → G is coarsely surjective and thus is a quasi-isometry.
Multiplication is the easiest nontrivial arithmetic function

Abstract It is shown that fixed point multiplication can be reduced to the evaluation of any member of a very large class of functions including most of the nontrivial functions used in practice. That means that whenever any such function can be evaluated by a Boolean circuit of size S ( n ), multiplication can be done with O( S ( n )) Boolean operations, as well.
Hong-ou-mandel cloning: quantum copying without an ancilla

We report on the first experimental 1 → 2, ancilla-free, phase-covariant quantum cloner by utilizing Hong-Ou-Mandel interference to clone photon polarization states. Using only linear optics, this Fock state non-perturbative cloner is an ideal BB84 eavesdropping device
Surface-induced layer formation in polyelectrolytes

We analyze, by means of a random phase approximation (RPA) calculation, the conditions under which a mixture of oppositely weakly charged polyelectrolytes can microsegregate in the neighborhood of a charged surface creating a layered structure. A number of stable layers can be formed if the surface is sufficiently strongly charged even at temperatures at which the bulk of the mixture is homogeneous. The wave-length of the induced concentration fluctuation is proportional to 1/f1/2 near the microphase transition, where f is the charge density of the polyelectrolytes.
Russian Firms in Transition: Champions, Challengers, and Chaff

This paper evaluates the survival potential of Russian firms. First, a composite measure of survival potential is developed using select characteristics of the firm, the firm's management, and the market structure faced by the firm. The measure is applied to 51 Russian firms, based on in-depth interviews with top-level managers of manufacturing, trade and other organizations conducted in 1995 in Moscow, Volgograd, Rostov and Taganrog. Using arbitrarily assigned weights for each element in the composite measure and a straight scale for categorizing firm performance, ten percent of the firms emerge as champions, more than fifty percent emerge as chaff. Second, two different proxies are used as a measure of survival potential, and the relative importance of firm, management and market structure characteristics is estimated. The weights are adjusted in the composite measure to reflect the regression results. The results indicate that survival potential is not driven by ownership structure, firm size, or the presence of monopoly power.
Magnetic tuning of the metal-insulator transition for uncompensated arsenic-doped silicon.

Barely insulating and barely metallic Si:As samples have been studied in the temperature range 4.2 K to 50 mK. Metallic samples show a new high-field magnetoresistance behavior explainable in terms of magnetic tuning of the critical density ${N}_{c}$. Insulating samples at fixed fields show Mott variable-range-hopping behavior and the increase of characteristic temperature ${T}_{0}(N,H)$ with $H$ results primarily from magnetic tuning of the localization-length exponent $\ensuremath{\nu}$. Magnetocapacitance results depend on field-induced changes in both ${N}_{c}$ and $\ensuremath{\nu}$.
Clinical experience with irradiation of inflammatory carcinoma of the breast with and without elective chemotherapy

From 1948 to 1972, 69 patients with inflammatory carcinoma of the breast were treated with irradiation alone. Because of a 46% incidence of local-regional failure, twice daily fractionated irradiation was given in 1972 to 11 patients; a decrease in local-regional failures (27%) was achieved. From 1973 through December 1976, preirradiation multidrug chemotherapy was added to the twice daily fractionated irradiation of 31 patients. Analysis of all patients with a minimum two-year follow-up demonstrates that chemotherapy does not improve local-regional control or freedom from disease rates, but does delay appearance of distant metastases.
Methodology for the synthesis of mimetics of peptide β-turns

Abstract This letter describes a scenario which provides for the stereospecific introduction of both the amino and carboxyl termini portion of a designed β-turn mimetic.
Homoclinic Orbits and Lagrangian Embeddings

This paper introduces techniques of symplectic topology to the study of homoclinic orbits in Hamiltonian systems. The main result is a strong generalization of homoclinic existence results due to Sere and to Coti-Zelati, Ekeland, and Sere [5]; [12], which were obtained by variational methods. Our existence result uses a modification of a construction due to Mohnke [10] (originally in the context of Legendrian chords), and an energy-capacity inequality of Chekanov [4]. In essence, we show the existence of a homoclinic orbit by showing a certain Lagrangian embedding cannot exist. We consider a (possibly time-dependent) Hamiltonian system on an exact symplectic manifold (W, ω = dλ) with a hyperbolic rest point. In the case of periodic time dependence, we show the existence of an orbit homoclinic to the rest point if λ(X H ) − H is positive and proper, H is positive outside a compact set and proper, and (W, ω) admits the structure of a Weinstein domain. In the autonomous case, we establish the existence of an orbit homoclinic to the rest point if the critical level is of restricted contact-type, and the critical level has a Hamiltonian displaceable neighborhood.
Ion-beam-enhanced adhesion in the electronic stopping region

We report here the first use of ion beams in the electronic stopping region to improve the adhesion of insulators to other materials. In particular, we have dramatically improved the bonding of Au films to teflon, ferrite, and SiO_2 by bombarding them with He and Cl, respectively. Improvements in bonding have also been observed for Au on glass, Au and Cu on sapphire, and Si_3N_4 on Si. The mechanism is apparently associated with sputtering and track-forming processes occuring in the electronic stopping region. Numerous applications are discussed.
Why and where do academics publish

Social and behavioral research is a complex activity that takes place in an ambiguous environment. This environment is more ambiguous than most researchers are aware, and it is changing more rapidly than most researchers realize. In fact, focused on their own activities and struggling with the very unclear messages from their environments, most researchers have very limited perspectives on what has been and is happening. This essay describes some current and important issues that confront social and behavioral researchers1. Although I expose my personal opinions, I do not aim to convince readers that these opinions are necessarily correct. Rather, I hope to stimulate reflection and discussion.
Regulatory and Legal Pressures and the Costs of Nasdaq Trading

The Nasdaq market came under intense pressure from regulators and class-action lawsuits following allegations of tacit collusion by Christie and Schultz (1994). This article examines the changes in transaction costs on the Nasdaq from January 1993 through June 1996 using 16 million trades in 30 stocks. Effective spreads cannot be matched. However, the autocovariance spread estimator of Roll (1984) works well with intraday data over this period. This spread estimator reveals that trading costs declined significantly for 29 of the 30 stocks over 1993-96. Article published by Oxford University Press on behalf of the Society for Financial Studies in its journal, The Review of Financial Studies.
Schumpeterian competition in alternative technological regimes

Abstract This paper presents an extension of the Nelson-Winter model of Schumpeterian competition that focuses on certain features of the ‘historical’ shape of industry evolution, particularly on the relative importance of entrants and established firms as sources of innovation.
An Investigation of the Application of Stratified Sampling in Probe-Based Traffic-Monitoring Systems

Probe vehicles represent samples in a traffic stream, and hence, probe-based traffic monitoring relies on effective sampling of vehicles. Current research views sampling from a networkwide perspective, and a single sample size is specified for the entire network. Using this method, research has indicated that the smaller routes in a network, such as minor and other arterials, are not adequately monitored. Increasing the sample size is not always a feasible option because of the restrictions of cost for use of the wireless network bandwidth and the availability of required number of probe vehicles. In this article, the authors describe a research effort that identified and extended stratified sampling as a method for increasing the efficacy of probe-based traffic monitoring. A methodology for application of stratified sampling for probe-based traffic monitoring is developed and implemented using a heavily traveled suburban traffic network simulation as a case study. Also, the authors discuss results of the...
Organizational Form and Efficiency: Evidence from Indian Sugar Manufacturing

Frontier cost and production functions are used to examine the effects of ownership on intrafirm differences in technical, cost, and allocative efficiency in the Indian sugar processing industry. Cooperatives are found to be as or more efficient than their counterparts. The results suggest that technical and coordination economies of vertical integration provide important advantages for the cooperative form of organization. We also find that seasonal labor is overutilized and permanent labor is underutilized relative to their cost-minimizing proportions. This is possibly a second-best solution in light of employment regulations. J. Comp. Econom., August 1995, 21(1), pp.29-53. U.S. International Trade Commission, Washington, DC 20463; University of Arkansas, Fayetteville, Arkansas, 72701-1201.
Two-Electron Three-Centered Bond in Side-On (η2) Uranyl(V) Superoxo Complexes

Theoretical calculations suggest a novel two-electron three-atom bonding scheme for complexation of O_2 with U(V) compounds, leading to the stabilization of superoxo complexes in the side-on (η^2) configuration. This binding motif is likely to play an important role in the oxidative processes involving trans-uranium compounds having valence 5f_φ electrons.
An experimental/analytical study of strains in encapsulated assemblies

A combined experimental and analytical study of strains that develop in encapsulated assemblies during casting, curing and thermal excursions is described. The experimental setup, designed to measure in situ strains, consisted of thin, closed-end, metal tubes that were instrumented with strain gages and thermocouples before being over-potted with an encapsulant. Three epoxy-based materials were studied. After cure of the encapsulant, tube strains were measured over the temperature range of {minus}55{degrees}C to 90{degrees}C. The thermal excursion experiments were then numerically modeled using finite element analyses and the results were compared to the experimental results. The predicted strains are overestimated (conservative) when a linear, elastic, temperature-dependent material model was assumed for the encapsulant and the stress free temperature was assumed to correspond to the cure temperature of the encapsulant. Very good agreement was obtained with the linear elastic calculations provided that the stress free temperature correspond to the onset of the glassy-to-rubbery transition range of the encapsulant. Finally, very good agreement was obtained when a viscoelastic material model was utilized and a stress free temperature corresponding to the cure temperature was assumed. 8 refs., 12 figs., 3 tabs.
Elliptic jets, part 2. Dynamics of coherent structures: Pairing

The dynamics of the jet column mode of vortex pairing in the near field of an elliptic jet was investigated. Hot-wire measurements and flow visualization were used to examine the details of the pairing mechanism of nonplanar vortical elliptic structures and its effect on such turbulence measures as coherent velocities, incoherent turbulence intensities, incoherent and coherent Reynolds, stresses, turbulence production, and mass entrainment. It was found that pairing of elliptic vortices in the jet column does not occur uniformly around the entire perimeter, unlike in a circular jet. Merger occurs only in the initial major-axis plane. In the initial minor-axis plane, the trailing vortex rushes through the leading vortex without pairing and then breaks down violently, producing considerably greater entrainment and mixing than in circular or plane jets.
SUCCESSIVE MONOPOLIES AND REGULATION IN A SPATIAL MODEL

A government authority regulates an upstream monopolist only if thereis a sufﬁcient welfare increase to justify doing so. A downstream ﬁrmstrategically increases costs in order to force regulation upstream. Thedecision to regulate increases proﬁt downstream, reduces proﬁt upstreamand reduces welfare relative to a model with no possibility for welfare-enhancing regulation.
JUDGING OTHERS: History, Ethics, and the Purposes of Comparison

The most interesting and perilous issue at present in comparative religious ethics is comparative ethical judgment—when and how to judge others, if at all. There are understandable historical and conceptual reasons for the current tendency to prefer descriptive over normative work in comparative religious ethics. However, judging those we study is inescapable—it can be suppressed or marginalized but not eliminated. Therefore, the real question is how to judge others (and ourselves) well, not whether to judge. Instead of bringing supposedly universal moral scoring systems to bear on reified “traditions” and “cultures,” it would be better to focus on the precise details of particular practices, motifs, and theories in various settings, and compare them with an eye to substantive issues of current ethical concern.
A Note on the Ratio of Positively Correlated Gamma Variates

Mielke and Flueck (1976) derived the density function and corresponding moments for the ratio of correlated gamma distributed variates, They considered a class of bivariate gamma distributions suggested by Cherian (1941) and David and Fix (1961)., Recently, Lee, Holland, and Flueck (1979) derived some additional distributional results using this class of functions,, This paper derives similar results using a different class of bivariate gamma distributions.
Solving non-linear arithmetic

We propose a new decision procedure for the existential theory of the reals. It performs a backtracking search for a model in R, where the backtracking is powered by a novel conflict resolution procedure based on cylindrical algebraic decomposition. The initial experimental results are very encouraging. The full article has been accepted at the 6th International Joint Conference on Automated Reasoning (IJCAR 2012).
Mass production of microalgae.

The limits of the earth’s arable lands1, the continuing need for more agricultural products and/or raw materials for industry2, and agricultural products for animal feed and human food3, the growth of world population4, and the increasing cost and depletion of fossil fuels5 all point to the need for new sources of agricultural products that will not tax the earth’s declining agricultural and energy resources. We suggest that microalgae may serve as a supplemental source of useful agricultural products6–8 without making demands on land or mineral resources or requiring large amounts of scarce or depleted energy supplies6 needed for conventional agriculture.
HOW TO MAKE THE QUANTUM ADIABATIC ALGORITHM FAIL

The quantum adiabatic algorithm is a Hamiltonian based quantum algorithm designed to find the minimum of a classical cost function whose domain has size N. We show that poor choices for the Hamiltonian can guarantee that the algorithm will not find the minimum if the run time grows more slowly than . These poor choices are nonlocal and wash out any structure in the cost function to be minimized, and the best that can be hoped for is Grover speedup. These failures tell us what not to do when designing quantum adiabatic algorithms.
Photochemical dehydrogenation of alkanes catalyzed by trans-carbonylchlorobis(trimethylphosphine)rhodium: Aspects of selectivity and mechanism

Deshydrogenation photochimique des methyl- et isopropyl cyclohexanes. Obtention d'alkyl cyclohexenes, de methylidene et d'isopropenyl cyclohexanes
Impacts on Ocean Heat from Transient Mesoscale Eddies in a Hierarchy of Climate Models

AbstractThe authors characterize impacts on heat in the ocean climate system from transient ocean mesoscale eddies. Their tool is a suite of centennial-scale 1990 radiatively forced numerical climate simulations from three GFDL coupled models comprising the Climate Model, version 2.0–Ocean (CM2-O), model suite. CM2-O models differ in their ocean resolution: CM2.6 uses a 0.1° ocean grid, CM2.5 uses an intermediate grid with 0.25° spacing, and CM2-1deg uses a nominal 1.0° grid.Analysis of the ocean heat budget reveals that mesoscale eddies act to transport heat upward in a manner that partially compensates (or offsets) for the downward heat transport from the time-mean currents. Stronger vertical eddy heat transport in CM2.6 relative to CM2.5 accounts for the significantly smaller temperature drift in CM2.6. The mesoscale eddy parameterization used in CM2-1deg also imparts an upward heat transport, yet it differs systematically from that found in CM2.6. This analysis points to the fundamental role that ocea...
Operational Characterization of the Solar-Thermal Power System Near Willard, New Mexico

The output capacity of the solar-thermal power system located near Willard, New Mexico was 19 kw (25 hp), with a primary application for irrigation pumping. Solar radiation was collected with north-south axis, east-west tracking, parabolic trough collectors having a total aperture area of 1275 m/sup 2/ (13,720 ft/sup 2/). Thermal storage was adequate for 20 hr. of power system operation utilizing a reaction-type turbine in conjunction with an organic Rankine-cycle heat engine. Operating efficiencies for the turbine component, heat engine, and the complete power system were 65-80 percent, 10-16 percent, and 1-3 percent, respectively. With the Willard system fully operational and near-term hardware improvement, an annual performance of 22 kw hr/m/sup 2/ of collector aperature area could be expected. Examples of component operation under variable environmental conditions are presented for the winter and summer seasons. Maintenance experience with the Willard system is also given.
Cyclosporine-associated end-stage nephropathy after cardiac transplantation: incidence and progression.

BACKGROUND The salutary immunosuppressive effects of cyclosporine in extending cardiac allograft survival may be curtailed by its nephrotoxic effects. We reviewed our first 9 years of experience with cyclosporine after cardiac transplantation, to evaluate the incidence and progression of cyclosporine-associated end-stage renal failure necessitating chronic hemodialysis. METHODS Retrospective computer-based file review and personal interview when possible. RESULTS The population at risk was comprised of all adult cardiac recipients surviving at least 3 years (n=293). Of these, 19 (6.5%) developed end-stage renal failure requiring chronic hemodialysis. There were 17 men and 2 women (mean age of 45 +/- 11 years). The mean creatinine clearance for the study group decreased by 38% (P<0.001 vs. before transplant) by 6 months after transplantation and by 48% by 3 years postoperatively (P<0.001 vs. before transplant). The mean serum creatinine rose by 80% (P< 0.001 vs. before transplant) by 6 months after transplantation and by 125% by 3 years postoperatively (P<0.001 vs. before transplant). Time elapsed from transplantation to hemodialysis ranged from 3.7 to 9.5 years (mean 6.4 +/- 2). Actuarial 1- year survival after onset of hemodialysis was 75%. CONCLUSIONS Although cyclosporine remains the central immunosuppressive agent for cardiac allograft recipients, its use leads to a greater than one-third decrease in creatinine clearance by 6 months after transplantation and progression to end-stage renal failure, requiring hemodialysis in 6.5% of cardiac transplant recipients. Moreover, these patients are at increased risk of death compared with other cardiac allograft recipients. This data warrants the search of alternative or adjunctive agents that would allow decreased dosing or reduced nephrotoxicity of cyclosporine, while maintaining equivalent survival.
Quantitative reasoning, complexity, and additive structures

Six fifth-grade children participated in a four-day teaching experiment on complex additively-structured problems, which was followed by in-depth interviews of individual children. The teaching experiment was meant to investigate children's difficulties in holding in mind at once situations in which one or more items played multiple roles. Two important difficulties were identified: (1) distinguishing between “difference” as the result of subtracting and “difference” as the amount by which one quantity exceeded another; and (2) indirect evaluation of an additive comparison. Sources of these difficulties, along with pedagogical and curricular recommendations for addressing them, are discussed.
On the temporal evolution of red sprites: Runaway theory versus data

The results of numerical simulations of red sprite discharges, namely the temporal evolutions of optical emissions, are presented and compared with observations. The simulations are done using the recently recalculated runaway avalanche rates. The temporal evolution of these simulations is in good agreement with ground-based photometer and CCD TV camera observations of red sprites. Our model naturally explains the ‘hairline’ of red sprites as a boundary between the region where the intensity of optical emissions associated with runaway breakdown has a maximum and the region where the intensity of optical emissions caused by conventional breakdown and ambient electron heating has a maximum. Other important characteristics of the simulated sprite such as color, shape, altitude, and intensity are in agreement with the observations as well. We also present for the first time simulations of red sprites with a daytime conductivity profile.
An Analytical Mixing Model for Buoyant Jet Injected Into Pipe Flow

An analytical model based on jet trajectory, diffusion, and flow establishment is presented which predicts mixing of a cold jet injected into a hot loop flow in a pipe. The impetus of the present investigation is to provide a method for calculating fluid temperature in the cold leg of a pressurized water reactor during injection of low temperature coolant, without recourse to sophisticated multidimensional computer programs. This has been spurred by the current interest in the pressurized thermal shock issue. The mixing model is based on jet centerline trajectory relations and the assumption of linear spread of jet diffusion layer. The model prediction is compared with representative cases of existing test data, and is shown to predict the temperature distribution reasonably well.
A class of stable, robust feedback controllers for large space structures

A two-level control system design is considered for large space structures, which consists of a primary and a secondary controller. The secondary or damping enhancement controller is shown to be stable and robust, even when time-invariant nonlinearities are present in the actuators and/or sensors. The use of Annular Momentum Control Devices (AMCD's) is also considered for secondary control. The primary attitude controller using collocated torque actuators and attitude and rate sensors is stable and robust. The effect of actuator/sensor dynamics on the stability of the primary and secondary controllers is considered. The AMCD's used for secondary control actuation can also be used for the primary controller.
An overhead reducing technique for Time Warp

In this paper, we introduce a technique to reduce the number of state savings and the event queue size of Time Warp. By reducing the state saving and the sizes of event queues, we can decrease the overhead and the maximum memory requirement in Time Warp. We exploit the look-ahead technique to get a lower bound time stamp of the next event and to determine if an event is safe to be executed. No State saving is carried out when the event execution is safe. This lower bound can be used to discard saved states even though the time stamps are greater than the global virtual time (GVT). We prove that the proposed technique is correct under both aggressive and lazy cancellation schemes. This technique can be implemented with minimal additional overhead. Benchmark results on logic simulation show that the mechanism can reduce the number of state savings and memory size requirements significantly.
Environmental regulation and US state-level production

Abstract Using US data from 1977–1986, we estimate the impact of environmental policy on state-level output using parametric and nonparametric techniques. While the nonparametric approach yields additional insights, the lack of a relationship between environmental regulation and output is robust.