cssi/SciSciGPT-SciSciNet huggingface dataset:
Dynamic circuit techniques used in SEAC and DYSEAC

All the high-speed arithmetic and control circuitry of an electronic digital computing machine to operate at a pulse repetition frequency of one megacycle can be built from just two types of etched-circuit plug-in packages. One contains a tube, a pulse transformer, and a set of germanium diode gates and buffers; the other contains lengths of electrical delay line and diode-resistor termination circuits. Complete flexibility of logical function is achieved through the wiring interconnecting the sockets, and the only additional requirements are the supply of clock pulses and of d-c power.
Population genetics, conservation and evolution in salmonids and other widely cultured fishes: some perspectives over six decades

This paper explores my shifting understandings of interactions primarily between salmonid fish culture and fish conservation during the latter half of the 20th century. The idea that conspecific natural and cultured fish were largely interchangeable among phenotypically similar populations began to change with the advent of molecular genetic markers. With the gradual clarification of major geographic lineages beginning in the 1970s came awareness that translocations among anadromous lineages were generally destined for failure; in contrast, gene flow more readily occurred among non-anadromous lineages and sometimes, species. Concurrently, data were accumulating that adaptations to their respective environments distinguished cultured and wild populations within a lineage. Reduced obstacles to gene flow at this level often resulted in homogenizations among wild and cultured fish in areas where widespread hatchery releases occurred; conversely, adaptive radiations in vacant habitats sometimes occurred over a few decades from single source hatchery releases. Current ideas relating to salmonid interbreeding, population substructure and culture germinated from these observations. Among lineages, resistance to gene flow is much greater between anadromous than purely freshwater populations or species. Ease of within-lineage gene flow in both groups is problematical with regard to cultured and wild populations because large-scale supplementation programs erode local adaptations and fine-scale population substructures. A potential ability to regenerate natural substructure upon relaxation of supplementation is offset by uncertainties of time scales and intrinsic capabilities homogenized populations. However these losses can be minimized by a management that separates harvest and reproduction of wild and cultured subpopulations. Some generality of this strategy to other fishes is supported by losses of local adaptations and outbreeding depression in black basses following population admixtures that parallel those observed in salmonids.
Secondary instability in boundary‐layer flows

The stability of a secondary Tollmien–Schlichting wave, whose wavenumber and frequency are nearly one half those of a fundamental Tollmien–Schlichting instability wave, is analyzed using the method of multiple scales. Under these conditions, the fundamental wave acts as a parametric exciter for the secondary wave. The results show that the amplitude of the fundamental wave must exceed a critical value to trigger this parametric instability. This value is proportional to a detuning parameter which is the real part of k − 2K, where k and K are the wavenumbers of the fundamental and its subharmonic, respectively. For Blasius flow, the critical amplitude is approximately 29% of the mean flow, and hence many other secondary instabilities take place before this parametric instability becomes significant. For other flows where the detuning parameter is small, such as free‐shear layer flows, the critical amplitude can be small, thus the parametric instability might play a greater role.
New Distant Companions to Known Nearby Stars. II. Faint Companions of Hipparcos Stars and the Frequency of Wide Binary Systems

We perform a search for faint, common proper motion companions of Hipparcos stars using the recently published Lepine-Shara Proper Motion-North catalog of stars with proper motion μ > 0.15'' yr-1. Our survey uncovers a total of 521 systems with angular separations 3'' 15.0. Our census is statistically complete for secondaries with angular separations 20'' 1000 AU. We observe that the distribution in orbital separations is consistent with Opik's law, f(s) ds ~ s-1 ds, only up to a separation s ≈ 4000 AU, beyond which it follows a more steeply decreasing power law f(s) ds ~ s-l ds with l = 1.6 ± 0.1. We also find that the luminosity function of the secondaries is significantly different from that of the single stars' field population, showing a relative deficiency in low-luminosity (8 < MV < 14) objects. The observed trends suggest either a formation mechanism biased against low-mass companions, or a disruption over time of systems with low gravitational binding energy.
SORTCERY-A High-Throughput Method to Affinity Rank Peptide Ligands.

Abstract Uncovering the relationships between peptide and protein sequences and binding properties is critical for successfully predicting, re-designing and inhibiting protein–protein interactions. Systematically collected data that link protein sequence to binding are valuable for elucidating determinants of protein interaction but are rare in the literature because such data are experimentally difficult to generate. Here we describe SORTCERY, a high-throughput method that we have used to rank hundreds of yeast-displayed peptides according to their affinities for a target interaction partner. The procedure involves fluorescence-activated cell sorting of a library, deep sequencing of sorted pools and downstream computational analysis. We have developed theoretical models and statistical tools that assist in planning these stages. We demonstrate SORTCERY's utility by ranking 1026 BH3 (Bcl-2 homology 3) peptides with respect to their affinities for the anti-apoptotic protein Bcl-xL. Our results are in striking agreement with measured affinities for 19 individual peptides with dissociation constants ranging from 0.1 to 60 nM. High-resolution ranking can be used to improve our understanding of sequence–function relationships and to support the development of computational models for predicting and designing novel interactions.
Preliminary Results on the Abradability of Porous, Sintered Seal Material

Preliminary results are presented for the case of titanium blade specimens, with bare tips (or covered with wear resistant, plasma sprayed materials) rubbing at 100 m/s against specimens of abradable nickel-chromium seal material moving toward the rotating blades at 0.0125 mm/s or at 0.025 mm/s. Using a two component dynamometer, the normal force of the rub interaction was measured and the shear component estimated. The elastoplastic properties of the seal material have been determined and those parameters as well as the rigidity of the rub tester system are considered in conjunction with those affecting the accuracy of the measurement of the forces arising at the blade-seal interface. The average and the 'local instantaneous' temperatures of the seal specimen and the temperature of the blade tip surface during rubbing are presented as functions of time. A seal densification factor is defined and its functional relationships with contact force components, temperature, wear ratio and blade tip abrading capability are indicated.
Implementation and application of a function data type

The modularization construct of subroutine, function, or procedure is well established in the scientific programming languages of today. In most cases, however, the construct is static in that once a function is defined and named it remains unchanged throughout the scope of its definition. We are concerned in this paper with the generalization to a function data type, that is, to the situation where one may have variables of type function which assume different specific procedures as their value within their scope. Notationally, implementation of the concept is made feasible by use of a juxtaposition operator. Computationally, the concept derives its usefulness from use of the contour model which allows activation record retention. Examples are given which show that the function data type concept subsumes less general techniques such as "coroutines" and "stream functions."
Optimizing distributed data bases: a framework for research

The interaction between computers and communication technology has steadily developed in recent years bringing with it the creation of large computer communication complexes. Earlier computer communication systems were generally focused around a single large computer installation. Although a strong argument can still be made for serving distributed users with a centralized system, we now witness an increasing number of systems in which information processing and storage functions are distributed among several computers. The idea is to distribute the resources (programs, data, computing hardware, etc.) of each computer site to a widely spread community of users. Various factors may favor a shift toward computer networks, especially with similarly structured organizations which are independent but can be motivated to share. The most well-known example is the network developed under the sponsorship of the Advanced Research Project Agency (ARPA), that links independent research organizations, all involved in solving closely related problems. The libraries of specialized software and data at each research center, make it attractive to link the computers of these organizations. Clearly, access to specialized data bases is a major feature of the networks and the cost incurred by such an access is an important consideration in determining the economic viability of this kind of resource sharing.
Ultrahigh reflection from a medium with ultraslow group velocity

We show that an incident wavepacket at the boundary to a medium with extremely slow group velocity, experiences enhanced reflection and a substantial spatial and temporal distortion of the transmitted wavepacket. In the limit of vanishing group velocity, light cannot be transferred into the medium due to its perfect reflectivity.
Column basis reduction and decomposable knapsack problems

We propose a very simple preconditioning method for integer programming feasibility problems: replacing the problem b^'@[email protected][email protected]?Z^n with b^'@?(AU)[email protected][email protected]?Z^n, where U is a unimodular matrix computed via basis reduction, to make the columns of AU short (i.e. have small Euclidean norm), and nearly orthogonal (see e.g. [Arjen K. Lenstra, Hendrik W. Lenstra, Jr., Laszlo Lovasz, Factoring polynomials with rational coefficients, Mathematische Annalen 261 (1982) 515-534; Ravi Kannan, Minkowski's convex body theorem and integer programming, Mathematics of Operations Research 12 (3) (1987) 415-440]). Our approach is termed column basis reduction, and the reformulation is called rangespace reformulation. It is motivated by the technique proposed for equality constrained IPs by Aardal, Hurkens and Lenstra. We also propose a simplified method to compute their reformulation. We also study a family of IP instances, called decomposable knapsack problems (DKPs). DKPs generalize the instances proposed by Jeroslow, Chvatal and Todd, Avis, Aardal and Lenstra, and Cornuejols et al. They are knapsack problems with a constraint vector of the form pM+r, with p>0 and r integral vectors, and M a large integer. If the parameters are suitably chosen in DKPs, we prove *hardness results, when branch-and-bound branching on individual variables is applied; *that they are easy, if one branches on the constraint px instead; and *that branching on the last few variables in either the rangespace or the AHL reformulations is equivalent to branching on px in the original problem. We also provide recipes to generate such instances. Our computational study confirms that the behavior of the studied instances in practice is as predicted by the theory.
Program analysis too loopy? Set the loops aside

Among the many obstacles to efficient and sound program analysis, loops may be the most prevalent. In program analyses that traverse paths, loops introduce a variable, possibly infinite and number of paths. This study assesses the potential of a program analysis technique that analyses loops separately and replaces the loop with a summary, similar to how many analyses use summaries for interprocedural analysis. This study is conducted by comparing the path counts when loops are analysed separately to a baseline path count where loops are traversed at most once. Although the number of paths is decreased in many cases, the magnitude of the decrease is typically not sufficient for long, complex functions. In addition, loops are classified by the task they perform, analysed using the number of paths as an estimate of their complexity and further inspected for programming elements that may make loop analysis more difficult. Of the 2869 loops used in this study, 84% of the loops have fewer than ten paths and only 1.3% have more than 10 000 paths. Nearly 60% of the loops traverse arrays or strings and roughly half of the loops contain a function call.
Relaxing the geodesic rule in defect formation algorithms

Abstract In studying the formation of topological defects, it is conventional to assume the “geodesic rule” which is equivalent to minimizing gradients of the order parameter. This assumption has been called into question in field-theoretic studies of first order phase transitions and in the case of local defects. We present a scheme for numerically investigating the formation of strings without assuming the geodesic rule. Our results show that the fraction of string in infinite strings grows as we deviate from the geodesic rule.
Photospheric and Subphotospheric Dynamics of Emerging Magnetic Flux

Magnetic fields emerging from the Sun’s interior carry information about physical processes of magnetic field generation and transport in the convection zone. Soon after appearance on the solar surface the magnetic flux gets concentrated in sunspot regions and causes numerous active phenomena on the Sun. This paper discusses some properties of the emerging magnetic flux observed on the solar surface and in the interior. A statistical analysis of variations of the tilt angle of bipolar magnetic regions during the emergence shows that the systematic tilt with respect to the equator (the Joy’s law) is most likely established below the surface. However, no evidence of the dependence of the tilt angle on the amount of emerging magnetic flux, predicted by the rising magnetic flux rope theories, is found. Analysis of surface plasma flows in a large emerging active region reveals strong localized upflows and downflows at the initial phase of emergence but finds no evidence for large-scale flows indicating future appearance a large-scale magnetic structure. Local helioseismology provides important tools for mapping perturbations of the wave speed and mass flows below the surface. Initial results from SOHO/MDI and GONG reveal strong diverging flows during the flux emergence, and also localized converging flows around stable sunspots. The wave speed images obtained during the process of formation of a large active region, NOAA 10488, indicate that the magnetic flux gets concentrated in strong field structures just below the surface. Further studies of magnetic flux emergence require systematic helioseismic observations from the ground and space, and realistic MHD simulations of the subsurface dynamics.
Quantum Phase Transition in the BCS-to-BEC Evolution of p-wave Fermi Gases

We discuss the possibility of a quantum phase transition in ultra-cold spin-polarized Fermi gases which exhibit a p-wave Feshbach resonance. We show that when fermionic atoms form a condensate that can be externally tuned between the BCS and BEC limits, the zero temperature compressibility and the spin susceptibility of the fermionic gas are non-analytic functions of the two-body bound state energy. This non-analyticity is due to a massive rearrangement of the momentum distribution in the ground state of the system. Furthermore, we show that the low temperature superfluid density is also non-analytic and exhibits a dramatic change in behavior when the critical value of the bound state energy is crossed.
Advection-Dominated Accretion Model of Sagittarius A ∗ : Evidence for a Black Hole at the Galactic Center

Sagittarius A*, which is located at the Galactic center, is a puzzling source. It has a mass of M = (2.5 ± 0.4) × 106 M☉, which makes it an excellent black hole candidate. Observations of stellar winds and other gas flows in its vicinity suggest a mass accretion rate of few × 10−6 M☉ yr-1. However, such an accretion rate would imply a luminosity greater than 1040 ergs-1 if the radiative efficiency is the usual 10%, whereas observations indicate a bolometric luminosity less than 1037 ergs-1. The spectrum of Sgr A* is unusual, with emission extending over many decades of wavelength. We present a model of Sgr A* that is based on a two-temperature optically thin advection-dominated accretion flow. The model is consistent with the estimated M and and fits the observed fluxes in the centimeter/millimeter and X-ray bands, as well as upper limits in the submillimeter and infrared bands; the fit is less good in the radio spectrum below 86 GHz and in γ-rays above 100 MeV. The very low luminosity of Sgr A* is explained naturally in the model by means of advection. Most of the viscously dissipated energy is advected into the central mass by the accreting gas, and therefore the radiative efficiency is extremely low, ~5 × 10-6. A critical element of the model is the presence of an event horizon at the center that swallows the advected energy. The success of the model could thus be viewed as confirmation that Sgr A* is a black hole.
Effect of Combined Transient Androgen Deprivation and Irradiation Following Radical Prostatectomy for Prostatic Cancer

Purpose: To evaluate whether transient androgen deprivation improves outcome in patients irradiated after radical prostatectomy for locally advanced disease, persistent or rising postoperative prostate specific antigen (PSA), or local recurrence. Methods and Materials: Records of 105 consecutive patients who were treated with pelvic irradiation after radical retropubic prostatectomy between August 1985 and December 1995 were reviewed. Seventy-four patients received radiation alone (mean follow up: 4.6 years), and 31 received transient androgen blockade with a gonadotropin-releasing hormone agonist (4) androgen receptor blocker (1) or both (24) beginning 2 months prior to irradiation (mean follow-up 3.0 years) for a mean duration of 6 months. Two of these patients were excluded from further analysis because they received hormonal therapy for more than 1 year. Patients received a prostatic fossa dose of 60 ‐70 Gy at 2 Gy per fraction; 48 patients also received pelvic nodal irradiation to a median dose of 50 Gy. Survival, freedom from clinical relapse (FFCR), and freedom from biochemical relapse (FFBR) were evaluated by the Kaplan-Meier method. Biochemical relapse was defined as two consecutive PSA measurements exceeding 0.07 ng/ml. Results: At 5 years after irradiation, actuarial survival for all patients was 92%, FFCR was 77%, and FFBR was 34%. FFBR was significantly better among patients who received transient androgen blockade before and during radiotherapy than among those treated with radiation alone (56 vs. 27% at 5 years, p 5 0.004). FFCR was also superior for the combined treatment group (100 vs. 70% at 5 years, p 5 0.014). Potential clinical prognostic factors before irradiation did not differ significantly between treatment groups, including tumor stage, summed Gleason histologic score, lymph node status, indication for treatment, and PSA levels before surgery or subsequent treatment. Multivariate analysis revealed that transient androgen deprivation was the only significant predictor for biochemical failure. Conclusion: This retrospective study of irradiation after radical prostatectomy suggests that transient androgen blockade and irradiation may improve freedom from early biochemical and clinically evident relapse compared to radiotherapy alone, although more prolonged follow-up will be needed to assess durability of impact upon clinical recurrence and survival rates. © 1998 Elsevier Science Inc. Prostatic neoplasms, Postoperative radiotherapy, Adjuvant therapy, Hormonal therapy, Androgen deprivation.
Needed: Better Accounting Concepts

Money can flow accurately everywhere because the words used in transactions — from a deposit in a local bank to settling a debt in a far‐off country — have precise meanings. But accounting, the language of business, does not have an accepted vocabulary. This is sorely needed, both for business and nonbusiness accounting. The new millennium is a good time to take stock.
GRAVITY GENERATION OF ELECTROMAGNETIC RADIATION AND THE LUMINOSITY OF QUASARS

A mechanism is proposed for the emission of radiation by charged particles in the gravitational field of a quasar whereby the gravitational field is coupled directly to the radiation field of the charge via the principle of equivalence. A generalized Larmor formula for the radiation emitted by a charge at rest in a gravitational field can account for the total radiant energy and spectral distribution emitted by quasars. This gravitational mechanism for the emission of electromagnetic radiation becomes more important than any other mechanism when the radius of the quasar is near its Schwarzschild radius.
Are There Any Redshift > 8 Gamma-Ray Bursts in the BATSE Catalog?

Several luminosity indicators have been found for gamma-ray bursts (GRBs) wherein measurable light-curve and spectral properties are well correlated with the peak luminosity. Several papers have each applied one different luminosity relation to find redshifts for BATSE GRBs and claim to identify specific bursts with -->z > 8. The existence of such high-redshift events is not surprising, as BATSE has enough sensitivity to see them and GRBs are expected out to the redshift of the first star formation. To improve results we used five luminosity relations with updated calibrations to determine redshifts with error bars. Combining these relations, we calculated the redshifts of 36 BATSE GRBs with claimed -->z > 8. Our results include 13 bursts with our derived best redshift -->zbest > 8, which looks promising at first. But the calculated redshift uncertainties are significantly large in these selected cases. With only one exception, all of our bursts have -->z1 ? low ? 9. The one exception (BATSE trigger 2035) is likely a short-duration burst at -->z 4. Our best case for a very high redshift event is BATSE trigger 3142 with -->zbest ? 20 and -->z1 ? low = 8.9; however, we can only say -->z > 4.1 at the 2 ? confidence level. In all, we cannot point toward any one BATSE burst as confidently having -->z > 8. One implication is to greatly weaken prior claims that GRBs have a steeply rising rate density out to high redshifts.
Interlayer magnetic coupling in epitaxial Fe/Cr(211) and (100) superlattices

The authors present magnetic characterization of epitaxial Fe/Cr(211) and Fe/Cr(100) superlattices grown simultaneously on MgO(110) and (100) substrates, respectively. At room temperature, the coupling for these two orientations oscillates in sign with the same period (18{angstrom}), phase and strength. These results indicate that the long-period oscillation is independent of the nested feature of the Cr Fermi-surface. They examine the temperature dependence of interlayer coupling and find a uniform AF bias develops in the (211) samples upon cooling and observe strongly temperature-dependent biquadratic coupling in the (100) samples.
On approaching the ultimate limits of communication using a photon-counting detector

Coherent states achieve the Holevo capacity of a pure-loss channel when paired with an optimal measurement, but a physical realization of this measurement scheme is as of yet unknown, and it is also likely to be of high complexity. In this paper, we focus on the photon-counting measurement and study the photon and dimensional efficiencies attainable with modulations over classical- and nonclassical-state alphabets. We analyze two binary-modulation architectures that improve upon the dimensional versus photon efficiency tradeoff achievable with the state-of-the-art coherent-state on-off keying modulation. We show that at high photon efficiency these architectures achieve an efficiency tradeoff that differs from the best possible tradeoff--determined by the Holevo capacity--by only a constant factor. The first architecture we analyze is a coherent-state transmitter that relies on feedback from the receiver to control the transmitted energy. The second architecture uses a single-photon number-state source.
The Stability of Double White Dwarf Binaries Undergoing Direct-Impact Accretion

We present numerical simulations of dynamically unstable mass transfer in a double white dwarf binary with initial mass ratio q = 0.4. The binary components are approximated as polytropes of index n = 3/2, and the initially synchronously rotating, semidetached equilibrium binary is evolved hydrodynamically, with the gravitational potential being computed through the solution of Poisson's equation. Upon initiating deep contact in our baseline simulation, the mass transfer rate grows by more than an order of magnitude over approximately 10 orbits, as would be expected for dynamically unstable mass transfer. However, the mass transfer rate then reaches a peak value, the binary expands, and the mass transfer event subsides. The binary must therefore have crossed the critical mass ratio for stability against dynamical mass transfer. Despite the initial loss of orbital angular momentum into the spin of the accreting star, we find that the accretor's spin saturates and that angular momentum is returned to the orbit more efficiently than has been previously suspected for binaries in the direct-impact accretion mode. To explore this surprising result, we directly measure the critical mass ratio for stability by imposing artificial angular momentum loss at various rates to drive the binary to an equilibrium mass transfer rate. For one of these driven evolutions, we attain equilibrium mass transfer and deduce that, effectively, qcrit has evolved to approximately 2/3. Despite the absence of a fully developed disk, tidal interactions appear to be effective in returning excess spin angular momentum to the orbit.
Semi-quantitative group testing

We consider a novel group testing procedure, termed semi-quantitative group testing, motivated by a class of problems arising in genome sequence processing. Semi-quantitative group testing (SQGT) is a non-binary pooling scheme that may be viewed as a combination of an adder model followed by a quantizer. For the new testing scheme we define the capacity and evaluate the capacity for some special choices of parameters using information theoretic methods. We also define a new class of disjunct codes suitable for SQGT, termed SQ-disjunct codes. We also provide both explicit and probabilistic code construction methods for SQGT with simple decoding algorithms.
Role of Siloxides in Transition Metal Chemistry and Homogeneous Catalysis

The role of siloxide ligands in the chemistry and catalysis of transition metals is reviewed. The first part deals with recent aspects of low-valent transition metal siloxide chemistry, while the second part describes some developments in the chemistry of transition metal siloxides in high oxidation states, in particular with regard to the stability of the M–OSi bond. The third part highlights applications of well-defined late and early transition metal siloxides as “single site” catalysts in homogeneous catalysis. Special emphasis is placed on the steric and electronic influence of the siloxide ligand on the activity, selectivity, and stability of the catalytically active metal species.
FAULT ANALYSIS ACROSS THE LIFE CYCLE OF INTERNET ROUTERS

Abstract This paper presents applications where models developed to support a particular task (end-of-line testing) are exploited to support other work processes during the product life cycle. The application domain is internet routers. The testing solution is based on a functional (data flow) model and a structural (Bayes) model. These models are used to interpret results of router testing for fault detection and diagnosis. Multiple faults and intermittent faults can be diagnosed. The paper shows that the models can also support manufacturing planning, especially test planning and the selection and placement of sensors for testing and diagnosis. Application of the models to fault detection and isolation during router operation is also discussed.
Drug-related lupus.

All physicians should be alerted to the many drugs and other agents that are associated with drug-related lupus, as there is an increasing number of such drugs. A wide range of immune responses and antibodies are being reported with this syndrome. A new concern is the perceived ability of new biologic treatments to induce these autoimmune phenomena. More in-depth studies of various environmental factors are providing new insights into possible mechanisms. These include the immune responses to the drugs, their metabolites, and drug-altered conjugates; bioactivation mechanisms of drug protein conjugation; the role of macrophages in antigen recognition and processing; and lastly, the important role of the acetylation of various drugs and the relationship to immunogenetic factors. Continued study of this human experimental model of lupus will help to clarify the etiology and mechanisms of systemic lupus erythematosus itself.
Complexation and Demetalation Reactions of Porphyrins

Abstract The mechanisms by which porphyrins form metal complexes in nature are of interest because of the importance of both the iron complexes, the active sites of hemoproteins, and the magnesium complexes, the chlorophylls. Currently there is interest in using chelated radioactive metal isotopes as diagnostic imaging and therapeutic agents; porphyrins are excellent candidates because of their extremely high stability constants with many metal ions. A great deal of effort has been invested to determine the reaction rates and examine implications of possible formation and decomposition mechanisms of metalloporphyrins: the subject has been periodically reviewed.1–5 It is my intent in this Comment to choose a few of the most salient and personally interesting major trends that have been elucidated and to indicate some of the more troublesome unsettled questions.
Unusual catalytic activity of analogues of 2-iodoxybenzoic acid in the hydrolysis of active phosphates

Abstract 2-Iodoxybenzoic acids catalyze the hydrolysis of active phosphorus esters with ca. 60–110% of the efficiency of their 2-iodosobenzoic acid analogues. Iodoxy compounds with considerable potential for use as phosphorus decontamination agents have been synthesized.
Radical-based regioselective C-H functionalization of electron-deficient heteroarenes: scope, tunability, and predictability.

Radical addition processes can be ideally suited for the direct functionalization of heteroaromatic bases, yet these processes are only sparsely used due to the perception of poor or unreliable control of regiochemistry. A systematic investigation of factors affecting the regiochemistry of radical functionalization of heterocycles using alkylsulfinate salts revealed that certain types of substituents exert consistent and additive effects on the regioselectivity of substitution. This allowed us to establish guidelines for predicting regioselectivity on complex π-deficient heteroarenes, including pyridines, pyrimidines, pyridazines, and pyrazines. Since the relative contribution from opposing directing factors was dependent on solvent and pH, it was sometimes possible to tune the regiochemistry to a desired result by modifying reaction conditions. This methodology was applied to the direct, regioselective introduction of isopropyl groups into complex, biologically active molecules, such as diflufenican (44)...
A paradigm for reasoning by analogy

Abstract A paradigm enabling heuristic problem solving programs to exploit an analogy between a current unsolved problem and similar but previously solved problem to simplify its search for a solution is outlined. It is developed in detail for a first-order resolution logic theorem prover. Descriptions of the paradigm, implemented LISP programs, and preliminary experimental results are presented. This is believed to be the first system that develops analogical information and exploits it so that a problem-solving program can speed its search.
Genetics of sarcoidosis.

Sarcoidosis likely results from an interplay of environmental and genetic factors. Despite a recent large multicenter study, A Case-Control Etiologic Study of Sarcoidosis (ACCESS), no single causative environmental agent has been identified. Family clustering and differences in racial incidence of sarcoidosis support an inherited susceptibility to sarcoidosis. Siblings of patients with sarcoidosis have about a fivefold increased risk of developing sarcoidosis. Certain human leukocyte antigen (HLA) alleles have been consistently associated with sarcoidosis susceptibility. Furthermore, HLA-DRB1*0301/DQB1*0201 has been associated with good prognosis in Lofgren's syndrome. Many candidate genes studied based on their potential function in immunopathogenesis have been evaluated in case-control studies, but few have been consistently associated with sarcoidosis across populations. Two genome scans have been reported in sarcoidosis. One in African Americans reporting linkage to chromosome 5 and the other in German families reporting linkage to chromosome 6. Follow-up studies on chromosome 6 identified the BTNL2 gene, a B7 family costimulatory molecule to be associated with sarcoidosis. Advances in genotyping and statistical analysis are helping to elucidate the genetics of sarcoidosis.
Unification of weak and hypercharge interactions at the TeV scale

Abstract A realistic SU (3) C × SU (3) W unified theory is constructed with a TeV sized extra dimension compactified on the orbifold S 1 / Z 2 , leaving only the standard model gauge group SU (3) C × SU (2) L × U (1) Y unbroken in the low energy 4D theory. The Higgs doublets are zero modes of bulk SU (3) W triplets and serve to normalize the hypercharge generator, apparently giving a tree-level prediction for the weak mixing angle: sin 2 θ =1/4. The orbifold boundary conditions imply a restricted set of SU (3) W gauge transformations: at an orbifold fixed point only the transformations of SU (2) L × U (1) Y are operative. This allows quarks to be located at this fixed point, overcoming the longstanding problem of how to incorporate matter in a unified SU (3) W theory. However, in general this local, explicit breaking of SU (3) W symmetry, necessary for including quarks into the theory, destroys the tree-level prediction for the weak mixing angle. This apparent contradiction is reconciled by making the volume of the extra dimension large, diluting the effects of the local SU (3) W violation. In the case that the electroweak theory is strongly coupled at the cutoff scale of the effective theory, radiative corrections to the weak mixing angle can be reliably computed, and used to predict the scale of compactification: 1–2 TeV without supersymmetry, and in the region of 3–6 TeV for a supersymmetric theory. The experimental signature of electroweak unification into SU (3) W is a set of “weak partners” of mass 1/2 R , which are all electrically charged and are expected to be accessible at LHC. These include weak doublets of gauge particles of electric charge (++,+), and a charged scalar. When pair produced, they yield events containing multiple charged leptons, missing large transverse energy and possibly Higgs and electroweak gauge bosons.
Coincidence techniques to study electron emission in ion-atom collisions

Abstract Electron emission as a function of emission angle and electron energy provides a very sensitive probe for testing our theoretical understanding of ion-atom collisions. For fast proton impact on gaseous targets the Born approximation has been shown to work quite well [1]. However, for structured particle impact a comparison with theory is more difficult. The experimental observation of the total electron emission must be compared with the sum of the theoretical calculations for projectile-only, target-only, and simultaneous projectile-target ionization. Thus a set of experiments will be discussed in which the electron emission is being recorded in coincidence with the post-collision projectile charge state. He+ -Ar is being studied for impact energies between 1 and 2 MeV. Coincidences between emitted electrons and stripped projectiles provide information about projectile ionization while information about simultaneous projectile-target ionization is obtained from stripped projectile-target ion coincidences.
Long Range Correlations in the Disordered Phase of a Simple Three State Lattice Gas

Abstract We investigate the dynamics of a three-state stochastic lattice gas, consisting of holes and two oppositely “charged” species of particles, under the influence of an “electric” field, at zero total charge. Interacting only through an excluded volume constraint, particles can hop to nearest-neighbor empty sites. With increasing density and drive, the system orders into a charge-segregated state. Using a combination of Langevin equations and Monte Carlo simulations, we study the steady-state structure factors in the disordered phase where homogeneous configurations are stable against small harmonic perturbations. They show a discontinuity singularity at the origin which in real space leads to an intricate crossover between power laws of different kinds.
Achieving high performance sonar-based wall-following

Abstract In this paper we develop a technique to achieve robust high performance real-time wallfollowing behavior of a mobile robot in an indoor office environment, more specifically, in a corridor environment. The mobile robot achieves increasingly better performance by learning the environment's (most important) features in successive runs through it. This allows the robot to perform the task repeatedly, reliably, increasing the speed at which it is done after every step, without losing accuracy. We are basing our approach in the Spatial Semantic Hiearchy [Kuipers et. al. 1993].
A Theory of Occupational Choice with Endogenous Fertility

Theories based on partial equilibrium reasoning alone cannot explain the widespread negative cross-sectional correlation between parental wages and fertility, without restrictive assumptions on preferences and childcare costs. We argue that incorporating a dynamic general equilibrium analysis of returns to human capital can help explain observed empirical patterns. Other by-products of this theory include explanations for intergenerational mobility without stochastic shocks, connections between mobility and fertility patterns, and locally determinate steady states. Comparative statics exercises on steady states shed light on the effects of education, childcare subsidies, child labor regulations, and income redistribution policy on long run living standards. (JEL H23, I31, J13, J24, J62, J82)
Weighing the Cosmological Energy Contents with Weak Gravitational Lensing

Using perturbation theory, Bernardeau, Van Waerbeke, & Mellier show that the skewness of the large-scale lensing convergence, or projected mass density, could be used to constrain Ωm, the matter content of the universe. However, deep weak-lensing field surveys in the near future will likely measure the convergence on small angular scales (10'), where the signal will be dominated by highly nonlinear fluctuations. We develop a method for computing the small-scale convergence skewness that gives predictions that agree well with existing results from ray-tracing N-body simulations but is significantly faster. We demonstrate that the small-scale convergence skewness is insensitive to the shape and normalization of the primordial (cold dark matter-type) power spectrum, making it dependent almost entirely on the cosmological energy contents. Moreover, nonlinear clustering appears to enhance the differences between predictions of the convergence skewness for a range of models. Hence, in addition to constraining Ωm, the small-scale convergence skewness from future deep and several degrees wide surveys can be used to differentiate between curvature-dominated and cosmological constant (Λ)-dominated models, as well as to constrain the equation of state of a quintessence component, thereby distinguishing Λ from quintessence. Finally, our method can be easily generalized to other measures such as the aperture mass statistics.
The extended Rayleigh theory of the oscillation of liquid droplets

The Rayleigh theory of oscillation of liquid drops is extended to include the effects of viscosity and a uniform external electric field. The resonant frequencies of the modes of the drop are shown to be shifted by the electric field. The magnitude and sign of the frequency shift depends on the dielectric constant of the drop. The condition for instability of drops in large electric fields is given and found to differ from that given by previous workers. This difference is attributed to the assumption by previous workers that the drops, under the influence of an electric field, distort into ellipsoids of revolution about the field direction. The dynamical equations are derived and the solution for small oscillations is given in an oscillating field and in an amplitude-modulated optical field.
Word-of-mouth and the forecasting of consumption enjoyment

The digital era has permitted rapid transfer of peer knowledge regarding products and services. In the present research, we explore the value of specific types of word-of-mouth information (numeric ratings and text commentary) for improving forecasts of consumption enjoyment. We present an anchoring-and-adjustment model in which the relative forecasting error associated with ratings and commentary depends on the extent to which consumer and reviewer have similar product-level preferences. To test our model, we present four experiments using a range of hedonic stimuli. Implications for the provision of consumer WOM are discussed.
Culture-dependent strategies in coordination games

We examine different populations’ play in coordination games in online experiments with over 1,000 study participants. Study participants played a two-player coordination game that had multiple equilibria: two equilibria with highly asymmetric payoffs and another equilibrium with symmetric payoffs but a slightly lower total payoff. Study participants were predominantly from India and the United States. Study participants residing in India played the strategies leading to asymmetric payoffs significantly more frequently than study participants residing in the United States who showed a greater play of the strategy leading to the symmetric payoffs. In addition, when prompted to play asymmetrically, the population from India responded even more significantly than those from the United States. Overall, study participants’ predictions of how others would play were more accurate when the other player was from their own populations, and they coordinated significantly more frequently and earned significantly higher payoffs when matched with other study participants from their own population than when matched across populations.
Dirac gaugino masses and supersoft supersymmetry breaking

We introduce a new supersymmetric extension of the standard model in which the gauge sector contains complete N = 2 supersymmetry multiplets. Supersymmetry breaking from the D-term vev of a hidden sector U(1) gauge field leads to Dirac soft supersymmetry breaking gaugino masses, and a new type of soft scalar trilinear couplings. The resulting squark and slepton masses are finite, calculable, positive and flavor universal. The Higgs soft mass squared is negative. The phenomenology of these theories differs significantly from the MSSM. We discuss a variety of possible origins for the soft operators and new fields, including models in both four and higher dimensions.
Racial disparities in the use of cardiac revascularization: does local hospital capacity matter?

Objective To assess the extent to which the observed racial disparities in cardiac revascularization use can be explained by the variation across counties where patients live, and how the within-county racial disparities is associated with the local hospital capacity. Data Sources Administrative data from Pennsylvania Health Care Cost Containment Council (PHC4) between 1995 and 2006. Study Design The study sample included 207,570 Medicare patients admitted to hospital for acute myocardial infarction (AMI). We identified the use of coronary artery bypass graft (CABG) and percutaneous coronary intervention (PCI) procedures within three months after the patient’s initial admission for AMI. Multi-level hierarchical models were used to determine the extent to which racial disparities in procedure use were attributable to the variation in local hospital capacity. Principal Findings Blacks were less likely than whites to receive CABG (9.1% vs. 5.8%; p<0.001) and PCI (15.7% vs. 14.2%; p<0.001). The state-level racial disparity in use rate decreases for CABG, and increases for PCI, with the county adjustment. Higher number of revascularization hospitals per 1,000 AMI patients was associated with smaller within-county racial differences in CABG and PCI rates. Meanwhile, very low capacity of catheterization suites and AMI hospitals contributed to significantly wider racial gap in PCI rate. Conclusions County variation in cardiac revascularization use rates helps explain the observed racial disparities. While smaller hospital capacity is associated with lower procedure rates for both racial groups, the impact is found to be larger on blacks. Therefore, consequences of fewer medical resources may be particularly pronounced for blacks, compared with whites.
Using corporate social responsibility performance to evaluate financial disclosure credibility

Due to the paucity of immediate and direct information about financial disclosure credibility, it is often difficult for investors to assess the credibility of financial disclosures (e.g. whether reported earnings are biased). Given this situation, the present study proposes and finds that investors use additional cues, such as information about corporate social responsibility (CSR) performance, to form overall impressions about management's honesty, credibility, and trustworthiness. Similar to other findings in the halo effect literature, we find that these overall impressions subsequently influence both investors' assessments of financial disclosure credibility and the prices they are willing to pay for a company's stock. The findings support the theoretical framework on financial disclosure credibility by (1) showing that management credibility is an important tool that investors use to assess disclosure credibility and (2) suggesting that management credibility is a multidimensional latent construct f...
Rubbling and optimal rubbling of graphs

A pebbling move on a graph removes two pebbles at a vertex and adds one pebble at an adjacent vertex. Rubbling is a version of pebbling where an additional move is allowed. In this new move one pebble is removed at vertices v and w adjacent to a vertex u and an extra pebble is added at vertex u. A vertex is reachable from a pebble distribution if it is possible to move a pebble to that vertex using rubbling moves. The rubbling number of a graph is the smallest number m needed to guarantee that any vertex is reachable from any pebble distribution of m pebbles. The optimal rubbling number is the smallest number m needed to guarantee a pebble distribution of m pebbles from which any vertex is reachable. We determine the rubbling and optimal rubbling number of some families of graphs and we show that Graham's conjecture does not hold for rubbling numbers.