cssi/SciSciGPT-SciSciNet huggingface dataset:
The Motion of Ellipsoids in a Second Order Fluid.

Abstract The rigid body motion of an ellipsoid in a second order fluid (SOF) under the action of specified (time independent) external forces and torques has been obtained to first order in the Weissenberg number by inverting the resistance relations for the force and torque under specified rigid body motions. The reciprocal theorem of Lorentz was used to bypass the calculation of the O(W) velocity field. The results agree with known analytic solutions for a SOF with the secondary to primary normal stress ratio of − 1 2 . The solution procedure was also tested by computing the torque on a translating prolate spheroid with aspect ratios ranging from slender bodies to near-spheres. One result is that for a SOF with zero secondary normal stress (Weissenberg fluid), previous asymptotic results for near-spheres were found to be accurate even at fairly large aspect ratios (e.g. 2). New results for non-degenerate ellipsoids suggest that the orientation (as monitored by Euler angles) and trajectory of sedimenting, non-axisymmetric particles such as ellipsoids provide useful information on the rheology of the suspending fluid.
Prostate biopsy indices: Toward efficient use of transrectal ultrasound

Abstract With increasing use of transrectal ultrasonography (TR US) it becomes important to establish guidelines for its appropriate utilization. Three hundred and twenty-two patients with either an abnormal digital rectal examination (DRE) or prostate-specific antigen (PSA), or both, were evaluated further for cancer by means of prostatic ultrasonography. Two hundred and twenty-five (70%) of these underwent ultrasound-guided biopsy, cancer was detected in 74 (23%), and 33 percent of all biopsy specimens were positive. Thus, the indices of biopsy: TR US (Bx: T), cancer: TR US (Ca: T), and cancer: biopsy (Ca:Bx) were 70 percent, 23 percent, and 33 percent, respectively. Comparing these indices with other earlier series (TR US used less selectively and with more recent series (TR US used more selectively), suggest that ratios in the range of biopsy: TR US of 70 percent to 75 percent, cancer: TR US of 25 percent to 30 percent, and cancer:biopsy of 30 percent to 40 percent may be expected with appropriate use of this imaging modality.
EXIST: mission design concept and technology program

The Energetic X-ray Imaging Survey Telescope (EXIST) is a proposed very large area coded aperture telescope array, incorporting 8m 2 of pixelated Cd-Zn-Te (CZT) detectors, to conduct a full-sky imaging and temporal hard x-ray survey each 95min orbit. With a sensitivity of ~0.05mCrab, it will extend the ROSAT soft x-ray and proposed ROSITA medium x-ray surveys into the hard x-ray band and enable identifiaiton and study of sources ~10-20X fainter than with the ~15-100keV survey planned for the upcoming Swift mission. At ~100-600keV, the ~1mCrab sensitivity is 300X that achieved in the only previous all-sky survey. EXIST will address a broad range of key science objectives: from obscured AGN and surveys for black holes on all scales, which constrain the acretion history of the universe, to the highest sensitivity and resolution studies of gamma-ray bursts it will conduct as the Next Generation Gamma-Ray Burst mission. We summarize the science objectives and mission drivers, and the results of a mission design study for implementation as a free flyer mission, with Delta IV launch. Key issues affecting the telescope and detector design are discussed, and a summary of some of the current design concepts being studied in support of EXIST is presented for the wide-field but high resolutoin coded aperture imaging and very large area array of imaging CZT detectors. Overall mission design is summarized, and technology development needs and a development program are outlined which would enable the launch of EXIST by the end of the decade, as recommended by the NAS/NRC Decadal Survey.
METROPOLITAN TRANSPORTATION PLANNING IN THE 1990S: COMPARISONS AND CONTRASTS IN NEW ZEALAND, CHILE AND CALIFORNIA

This article reviews major events and trends in metropolitan transportation planning and policy during the 1990s in three divergent Pacific rim jurisdictions: New Zealand, Chile, and California. Major metropolitan areas in each country have seen rising motorization, increasing congestion, and privatization of transportation services. Devolution of transportation planning responsibility has occurred; to a lesser degree, funding responsibility has been devolved from central to regional/local government. New Zealand pushed privatization harder in the 1990s than either Chile or California. While no dominant model of transportation planning has emerged, metropolitan-level planning has become more prominent and autonomous in each country studied.
A simplified theory of ELF propagation in the Earth-ionosphere transmission line.

An approximate theory of ELF propagation in the Earth-ionosphere transmission line is developed by combining the reflection theory of Booker and Lefeuvre (1977) with Greifinger and Greiferinger’s (1978, 1979) treatment of the effect of ionization below the level of reflection. The theory allows for the influence of the Earth’s magnetic field, for reflection from the gradient on the underside of the D region (or, at night, of a ledge below the E region), for reflection from the gradient on the underside of the E region, and for reflection from the gradient on the topside of the E region. The procedure is to compare local vertical gradient with local wavelength, thereby classifying altitude into intervals where the gradient is high and ones where it is low. Where the gradient is low, the phase-integral treatment is adequate. An interval where the gradient is high may, to a first approximation, be replaced by a discontinuity. The amount of the discontinuity is the difference between the refractive indices at the top and bottom of the interval of high gradient, judged in relation to local Wavelength. It is then a matter of combining reflections from the several discontinuities. This requires calculation of the complex phase-changes between the discontinuities. But these are the intervals where the phase-integral treatment is available. To a beter approximation, there is a non-zero phase-change associated with an interval of high gradient. The method for incorporating this is described.
Synthesis, solid-state structure, and reduction of 1,1-dichloro-2,3,4,5-tetramethylsilole

Abstract The previously unknown 1,1-dichloro-2,3,4,5-tetramethyl-1-silacylopenta-2,4-diene ( 3 ) was prepared in a three-step synthesis starting from zirconocene dichloride, 2-butyne, and n-butyllithium via bis(cyclopentadienyl)-2,3,4,5-tetramethyl-1-zirconacyclopenta-2,4-diene ( 1 ) and 1,4-diiodo-1,2,3,4-tetramethylbuta-1,3-diene ( 2 ). 3 was characterized by NMR spectroscopy and single-crystal X-ray diffraction. Reaction of the new silole 3 with 4 equivalents of lithium in THF gives the corresponding dianion 4 . 1 H-, 13 C-, and 29 Si-NMR chemical shifts of 4 compared with 3 indicate some aromatic character for the ionic species. Trapping of 4 with Me 3 SiCl gives 1,1-bis(trimethylsilyl)-2,3,4,5-tetramethysilole ( 5 ) in quantitative yield.
Discovery of X-Ray Pulsations from the Compact Central Source in the Supernova Remnant 3C 58

We report on high time and spatial resolution observations of the supernova remnant (SNR) 3C 58 using the High Resolution Camera (HRC) on the Chandra X-Ray Observatory. These data show a pointlike central source from which we detect 65.68 ms pulsations at 6.7 σ significance. We interpret these pulsations as corresponding to a young rotation-powered pulsar, PSR J0205+6449, that is associated with and powers SNR 3C 58. Analysis of archival Rossi X-Ray Timing Explorer (RXTE) data from 3 years earlier confirms these pulsations and allows us to determine a spin-down rate of = 1.93 × 10-13 s s-1. Assuming a magnetic dipole model for PSR J0205+6449, we infer a surface magnetic field of 3.6 × 1012 G. The historical age for the pulsar (based on its identification with SN 1181) is 820 yr. Taken with the observed period and spin-down rate, we derive an initial spin period of ~60 ms.
R&D Subsidies and Multinational Firm Ownership

Most industrialized countries subsidize private sector R&D, even under some circumstances when the firm is owned by foreigners. The present paper, using a simple theoretical analysis of a monopoly ...
7 × 7 Reconstruction on Si(111) Resolved in Real Space

The 7× 7 reconstruction on Si(111) was observed in real space by scanning tunneling microscopy. The experiment strongly favors a modified adatom model with 12 adatoms per unit cell and an inhomogeneously relaxed underlying top layer.
Nutrition interventions in aging and age-associated disease.

: The nutritional status and needs of elderly people are associated with age-related biological and often socioeconomic changes. Decreased food intake, a sedentary lifestyle, and reduced energy expenditure in older adults altogether become critical risk factors for malnutrition, especially protein and micronutrients. Surveys indicate that the elderly are particularly at risk for marginal deficiency of vitamins and trace elements. Changes in bodily functions, together with the malnutrition associated with advancing age, increase the risk of developing a number of age-related diseases. Chronic conditions pose difficulties for the elderly in carrying out the activities of daily living and may increase the requirements for certain nutrients due to changes in absorptive and metabolic capacity. Free radicals and oxidative stress have been recognized as important factors in the biology of aging and of many age-associated degenerative diseases. In this regard, modulation of oxidative stress by calorie restriction, as demonstrated in animal models, is suggested as one mechanism to slow the aging process and the decline of body functions. Therefore, dietary components with antioxidant activity have received particular attention because of their potential role in modulating oxidative stress associated with aging and chronic conditions. Several studies have indicated potential roles for dietary antioxidants in the reduction of degenerative disease such as vascular dementia, cardiovascular disease, and cancer. In support of epidemiological studies, our recent studies indicate that the antioxidant properties of vitamin E and polyphenols present in green tea may contribute to reducing the risk of cardiovascular disease, in part by reducing the susceptibility of low density lipoproteins to oxidation, decreasing the vascular endothelial cell expression of pro-inflammatory cytokines, and decreasing the expression of adhesion molecules and monocyte adhesion. Recently, we also demonstrated that these dietary antioxidants may have a preventive role in cancer, potentially through the suppression of angiogenesis by inhibiting interleukin-8 production and the cell junction molecule VE-cadherin. These findings concur with epidemiologic, clinical, and animal studies suggesting that the consumption of green tea and vitamin E is associated with a reduced risk of cardiovascular disease and cancer, the leading causes of morbidity and mortality among the elderly.
Classical hair in string theory I: General formulation

Abstract We discuss why classical hair is desirable for the description of black holes, and show that it arises generically in a wide class of field theories involving extra dimensions. We develop the canonical formalism for theories with the matter content that arises in string theory. General covariance and duality are used to determine the form of surface terms. We derive an effective theory (reduced Hamiltonian) for the hair in terms of horizon variables. Solution of the constraints expresses these variables in terms of hair accessible to an observer at infinity. We exhibit some general properties of the resulting theory, including a formal identification of the temperature and entropy. The Cvetic-Youm dyon is described in some detail as an important example.
Gene Deletion in Urothelium by Specific Expression of Cre Recombinase

Urothelium that lines almost the entire urinary tract acts as a permeability barrier and is involved in the pathogenesis of major urinary diseases, including urothelial carcinoma, urinary tract inf...
Measuring High-Order Moments of the Galaxy Distribution from Counts in Cells -- The Edgeworth Approximation

To probe the weakly nonlinear regime, past the point where simple linear theory is sufficient to describe the statistics of the density distribution, we measure the skewness (S3) and kurtosis (S4) of the count probability distribution function (CPDF) of the IRAS 1.2 Jy sample obtained from counts in cells. These quantities are free parameters in a maximum likelihood fit of an Edgeworth expansion convolved with a Poissonian to the observed CPDF. This method, applicable on scales 5 h-1 Mpc, is appreciably less sensitive to the tail of the distribution than are measurements of S3 and S4 from moments of the CPDF. We measure S3 and S4 to l ~ 50 h-1 Mpc; the data are consistent with scale invariance, yielding averages of S3 = 2.83 ? 0.09 and S4 = 6.89 ? 0.68. These values are higher than those found by Bouchet et al. in 1993 (S3 = 1.5 ? 0.5 and S4 = 4.4 ? 3.7) using the moments method on the same data set, owing to lack of correction for finite-volume effects in the latter work. Unlike the moments method, our results are quite robust to the fact that IRAS galaxies are underrepresented in cluster cores. We use N-body simulations to show that our method yields unbiased results.
QUASARS PROBING QUASARS. III. NEW CLUES TO FEEDBACK, QUENCHING, AND THE PHYSICS OF MASSIVE GALAXY FORMATION

Galaxies hosting z ~ 2 quasars are the high-z progenitors of today's massive red and dead galaxies. With close pairs of quasars at different redshifts, a background quasar can be used to study a foreground quasar's halo gas in absorption, providing a wealth of information about feedback, quenching, and the physics of massive galaxy formation. We present a Keck/High Resolution Echelle Spectrometer spectrum of the bright background quasar in a projected pair with angular separation ? = 13.3 arcsec corresponding to R ? = 108 kpc at the redshift of the foreground quasar z fg = 2.4360 ? 0.0005, precisely determined from Gemini/Gemini Near-Infrared Spectrograph near-IR spectroscopy. Our echelle spectrum reveals optically thick gas (N H I 1019.7 cm?2) coincident with the foreground quasar redshift. The ionic transitions of associated metal lines reveal the following properties of the foreground quasar's halo: (1) the kinematics are extreme with absorption extending to +780 km s?1 relative to z fg; (2) the metallicity is nearly solar; (3) the temperature of the predominantly ionized gas is T 20,000 K; (4) the electron density is n e ~ 1 cm?3 indicating a characteristic size ~10-100 pc for the absorbing clouds; (5) there is little (if any) warm gas 105 K T 106 K; (6) the gas is unlikely illuminated by the foreground quasar, implying anisotropic or intermittent emission. The mass of cold T ~ 104 K gas implied by our observations is significant, amounting to a few percent of the total expected baryonic mass density of the foreground quasar's dark halo at r ~ 100 kpc. The origin of this material is still unclear, and we discuss several possibilities in the context of current models of feedback and massive galaxy formation.
Coherent spin rotation in the presence of a phonon-bottleneck effect

A characteristic of spin reversal in the presence of phonon bottleneck is the deviation of the magnetization cycle from a reversible function into an opened hysteresis cycle. In recent experiments on molecular magnets (e.g. V15 and Ru2), the zero-field level repulsion was sufficiently large to ensure an otherwise adiabatic passage through zero-field and the magnetization curves can be described by using only a phonon-bottleneck model. Here, we generalize the phonon-bottleneck model into a model able to blend the non-adiabatic dynamics of spins with the presence of a non-equilibrium phonon bath. In this simple phenomenological model, Bloch equations are written in the eigenbasis of the effective spin Hamiltonian, considered to be a two-level system at low temperatures. The relaxation term is given by the phonon-bottleneck mechanism. To the expense of calculus time, the method can be generalized to multi-level systems, where the notion of Bloch sphere does not apply but the density matrix formalism is still applicable.
What Is Wrong with this Picture? A Problem with Comparative Return Plots on Finance Websites and a Bias Against Income-Generating Assets

This paper brings to light and discusses a systemic issue in the calculation and display of relative return information as currently seen on some of the most prominent finance websites; income-generating events such as dividends and interest are not included in relative return calculations and all comparative return graphics. The resulting ranking of the securities, based on such incomplete returns, is essentially meaningless from a total return perspective, yet they are being served to millions of investors every day. This could lead to the formation of a possible availability heuristic and an optical bias against fixed-income and other income generating assets. This problem has gone unnoticed for many years with no discussion of the topic either in the academic or practitioner press. The ready availability of such unclear or inaccurate information from sources generally perceived to be credible can, in this age of do-it-yourself portfolio management, have serious and damaging financial consequences to t...
Temperature-Dependent Electrical and Micromechanical Properties of Lanthanum Titanate with Additions of Yttria

Temperature-dependent elastic properties were determined by establishing continuous flexural vibrations in the material at its lowest resonance frequency of 31tHz. The imaginary part of the complex impedance plotted as a function of frequency and temperature reveals a thermally activated peak, which decreases in magnitude as the temperature increases. Additions of yttria do not degrade the electromechanical in particularly the elastic and anelastic properties of lanthanum titanate. Y2O3/La2Ti2O7 exhibits extremely low internal friction and hence may be more mechanical fatigue-resistant at low strains.
Radii of Rapidly-Rotating Stars, with Application to Transiting-Planet Hosts

The currently favored method for estimating radii and other parameters of transiting-planet host stars is to match theoretical models to observations of the stellar mean density ρ*, the effective temperature T eff, and the composition parameter [Z]. This explicitly model-dependent approach is based on readily available observations, and results in small formal errors. Its performance will be central to the reliability of results from ground-based transit surveys such as TrES, HAT, and SuperWASP, as well as to the space-borne missions MOST, CoRoT, and Kepler. Here, I use two calibration samples of stars (eclipsing binaries (EBs) and stars for which asteroseismic analyses are available) having well-determined masses and radii to estimate the accuracy and systematic errors inherent in the ρ* method. When matching to the Yonsei-Yale stellar evolution models, I find the most important systematic error results from selection bias favoring rapidly rotating (hence probably magnetically active) stars among the EB sample. If unaccounted for, this bias leads to a mass-dependent underestimate of stellar radii by as much as 4% for stars of 0.4 M ☉, decreasing to zero for masses above about 1.4 M ☉. Relative errors in estimated stellar masses are three times larger than those in radii. The asteroseismic sample suggests (albeit with significant uncertainty) that systematic errors are small for slowly rotating, inactive stars. Systematic errors arising from failings of the Yonsei-Yale models of inactive stars probably exist, but are difficult to assess because of the small number of well-characterized comparison stars having low mass and slow rotation. Poor information about [Z] is an important source of random error, and may be a minor source of systematic error as well. With suitable corrections for rotation, it is likely that systematic errors in the ρ* method can be comparable to or smaller than the random errors, yielding radii that are accurate to about 2% for most stars.
Occurrence and metabolism of prostaglandins in the housefly, Musca domestica (L.)

Abstract Prostaglandins (PGs) of the E and F series were quantified in the housefly by radioimmunoassay (RIA). Whole insects and reproductive tissues from both sexes contained PGE (1+2) and PDG 2α which increased in amount with age. PGF 2α levels were higher than PGE series in extracts of whole male and female insects and in ovaries. Male reproductive tissues contained higher amounts of PGE (1+2) than PGF 2α . Gas chromatographic-mass spectrometric (GC-MS) analyses of the products formed after injection of arachidonic acid (20:4) and eicosatrienoic acid (20:3, n-6) into male and femal insects demonstrated the conversion of 20:4 to PGF 2α and 20:3 to PGF 1α . Radiolabeled 20:4 injected into houseflies was rapidly converted to PGE 2 and PGF 2α . The catabolism of PGE 2 was more rapid than PGF 2α in males, whereas in females, PGE 2 and PGF 2α were converted to more polar products at similar rates. Radiolabeled 20:4 injected in the hemolymph was incorporated into the reproductive tracts of male insects. About 2.1% of the total radioactivity from [ 3 H]20:4 injected into males just prior to mating was transferred to females during mating. Thus, PG are formed from 20:4 in male and female houseflies. During mating, 20:4 is transferred from males to females where it can be metabolized to PGF 2α .
Myriastramides A–C, new modified cyclic peptides from the Philippines marine sponge Myriastra clavosa

Abstract Chemical investigation of the Philippines marine sponge Myriastra clavosa has resulted in the isolation of three new cyclic octapeptides, myriastramides A ( 1 ), B ( 2 ), and C ( 3 ). The structures of compounds 1–3 were assigned based on extensive NMR spectroscopic analyses and a series of degradation and derivatization studies.
Enantioselective synthesis of allylic alcohols by the sequential aminoxylation-olefination reactions of aldehydes under ambient conditions.

A novel, highly enantioselective synthesis of O-amino-substituted allylic alcohols by the sequential asymmetric α-aminoxylation/Wadsworth−Emmons−Horner olefination reactions of aldehydes is presented.
Thresholds and optimal binary comparison search trees

We present an O(n4)-time algorithm for the following problem: Given a set of items with known access frequencies, find the optimal binary search tree under the realistic assumption that each comparison can only result in a two-way decision: either an equality comparison or a less-than comparisons. This improves the best known result of O(n5) time, which is based on split tree algorithms. Our algorithm relies on establishing thresholds on the frequency of an item that can occur as an equality comparison at the root of an optimal tree.
Age‐related differences in breast carcinoma knowledge, beliefs, and perceived risk among women visiting an academic general medicine practice

BACKGROUND This study assessed whether age-related differences in breast carcinoma knowledge and perceived risk exist among women in a primary care setting and whether these women's beliefs about the best age to begin screening mammography reflect those of their physicians. METHODS Consecutive women ages 30-70 years who visited an academic general medicine practice were asked to complete a questionnaire assessing breast carcinoma knowledge, beliefs, and perceived risk. Women's risk estimates were compared with individual risk probabilities derived from the Gail model. Women's beliefs about when to begin screening mammography were compared with the beliefs of the attending physicians in the practice. Questionnaire results were compared across age groups. RESULTS Six hundred seventy-four women completed the survey. Overall, knowledge scores were negatively correlated with age (correlation coefficient = -0.30, P = 0.001). The level of knowledge about the benefits of mammography was high across all age groups. In contrast, knowledge that breast carcinoma incidence increases with age was poor. Only 28% of all women recognized that breast carcinoma is more common among women age 65 years than among women age 40 years. Among all women, 26% underestimated their risk of developing breast carcinoma in the next 10 years, 32% correctly estimated their risk, and 42% overestimated their risk. Fifty-five percent thought that mammography should begin when a woman is age 30-35 years. In contrast, all surveyed physicians recommended that a woman start undergoing mammography at age 40 years or older. CONCLUSIONS In this primary care setting, older women had poorer breast carcinoma knowledge than younger women but were equally likely to appreciate the benefits of mammography. Most women were unaware that age is a risk factor for breast carcinoma. Improved education of females by their physicians may resolve some of the observed discrepancies regarding the optimal age to begin screening mammography. Cancer 1997; 80:413-20. © 1997 American Cancer Society.
An exact Ramsey principle for block sequences

We prove an exact, i.e., formulated without $\Delta$-expansions, Ramsey principle for infinite block sequences in vector spaces over countable fields, where the two sides of the dichotomic principle are represented by espectively winning strategies in Gowers' block sequence game and winning strategies in the infinite asymptotic game. This allows us to recover Gowers' dichotomy theorem for block sequences in normed vector spaces by a simple application of the basic determinacy theorem for infinite asymptotic games.
The deconfined phase near Tc and its decay into hadrons

Abstract We sketch an effective theory for the deconfined state of QCD near Tc. This relates the behavior of the expectation value of the Polyakov loop, and its two-point functions, to the pressure. Defining the “mass” of three and two gluon states from the imaginary and real parts of the Polyakov loop, while this ratio is 3:2 in perturbation theory, at T c + it is 3:1. We also discuss the decay of the deconfined state into hadrons.
Silyl Triflate-Mediated Ring-Closure and Rearrangement in the Synthesis of Potential Bisfuran-Containing Intermediates of Aflatoxin Biosynthesis

The biosynthetic pathway to the potent mycotoxin aflatoxin B1 is unusually long and complex, proceeding from anthraquinone to xanthone to coumarin nuclear types bearing fused tetrahydro- and bisdihydrofuran rings. A synthetic strategy is described involving two silyl triflate-mediated cyclization and rearrangement processes that have enabled both furofuran oxidation states to be readily achieved and undesired but thermodynamically favorable side reactions to be avoided in the preparation of these ring systems. In the first an o-methoxymethyl phenylacetaldehyde is cyclized directly to the five-membered, differentially protected hemiacetal, while in the second this group, appropriately substituted, can be rearranged to a 4-trialkylsilyloxy-2,5-methano-1,3-benzodioxepane. The latter masked dialdehyde is sufficiently stable to strong base, mild acid, and oxidants to allow all needed aryl ring systems to be constructed. Using these methods, total syntheses of (±)-versicolorin B, (±)-versicolorin A, its hemiace...
Top-k frequent itemsets via differentially private FP-trees

Frequent itemset mining is a core data mining task and has been studied extensively. Although by their nature, frequent itemsets are aggregates over many individuals and would not seem to pose a privacy threat, an attacker with strong background information can learn private individual information from frequent itemsets. This has lead to differentially private frequent itemset mining, which protects privacy by giving inexact answers. We give an approach that first identifies top-k frequent itemsets, then uses them to construct a compact, differentially private FP-tree. Once the noisy FP-tree is built, the (privatized) support of all frequent itemsets can be derived from it without access to the original data. Experimental results show that the proposed algorithm gives substantially better results than prior approaches, especially for high levels of privacy.
Investment dynamics in electricity markets

We investigate the incentives for investments in capacity in a simple strategic dynamic model with random demand growth. We construct non-collusive Markovian equilibria where the firms’ decisions depend on the current capacity stock only. The firms maintain small reserve margins and high market prices, and extract large rents. In some equilibria, rationing occurs with positive probability, so the market mechanism does not ensure ‘security of supply’. Usually, the price cap reflects the value of lost energy or lost load (VOLL) that consumers place on severely reducing consumption on short notice. Our analysis identifies a minimum price cap, unrelated to the VOLL, that allows the firms to recoup their investment and production costs in equilibrium. However, raising the price cap above this minimum increases market prices and reduces consumer surplus, without affecting the level of investment.
Distribution Functions of Poisson Random Integrals: Analysis and Computation

We want to compute the cumulative distribution function of a one-dimensional Poisson stochastic integral $I(g) = \displaystyle \int_0^T g(s) N(ds)$ , where N is a Poisson random measure with control measure n and g is a suitable kernel function. We do so by combining a Kolmogorov–Feller equation with a finite-difference scheme. We provide the rate of convergence of our numerical scheme and illustrate our method on a number of examples. The software used to implement the procedure is available on demand and we demonstrate its use in the paper.
Statistical topic models for multi-label document classification

Machine learning approaches to multi-label document classification have to date largely relied on discriminative modeling techniques such as support vector machines. A drawback of these approaches is that performance rapidly drops off as the total number of labels and the number of labels per document increase. This problem is amplified when the label frequencies exhibit the type of highly skewed distributions that are often observed in real-world datasets. In this paper we investigate a class of generative statistical topic models for multi-label documents that associate individual word tokens with different labels. We investigate the advantages of this approach relative to discriminative models, particularly with respect to classification problems involving large numbers of relatively rare labels. We compare the performance of generative and discriminative approaches on document labeling tasks ranging from datasets with several thousand labels to datasets with tens of labels. The experimental results indicate that probabilistic generative models can achieve competitive multi-label classification performance compared to discriminative methods, and have advantages for datasets with many labels and skewed label frequencies.
Diastereospecific tandem Michael-like addition / electrophilic bromination: A one-pot tandem asymmetric synthesis of precursors of unusual amino acids

Abstract A systematic series of key intermediates of unusual β-methyl-amino acids have been synthesized by using a modified Evans auxiliary in an asymmetric Michael-like reaction followed by direct bromination in a one-pot reaction.
Determinants of interest group formation

It is widely recognized that interest groups affect both microeconomic and macroeconomic outcomes. However, few researchers have attempted to discern empirically the factors that contribute to interest group activity. This paper provides a test of several theories of group formation in a panel setting. A nation’s stability, socioeconomic development, political system, size, and diversity all appear to contribute to interest group formation, as predicted by theory.
Brokerage Pricing under Competition

Abstract This paper reexamines the popular assumption that real estate commissions are fixed over time. It shows how the competitively determined commission rate responds to changes in the housing market and broker cost conditions. One testable implication is that competition promotes counter-cyclical changes in the commission rate. The empirical analysis of commission rate determinants using data covering an entire urban housing market through its downturn and expansion phases reveals the counter-cyclical movement in commission rates predicted by the competitive model.
Searching among intervals and compact routing tables

Shortest paths in weighted directed graphs are considered within the context of compact routing tables. Strategies are given for organizing compact routing tables so that extracting a requested shortest path will takeo(k logn) time, wherek is the number of edges in the path andn is the number of vertices in the graph. The first strategy takesO (k+logn) time to extract a requested shortest path. A second strategy takes Θ(k) time on average, assuming alln(n−1) shortest paths are equally likely to be requested. Both strategies introduce techniques for storing collections of disjoint intervals over the integers from 1 ton, so that identifying the interval within which a given integer falls can be performed quickly.
Active Vibration Control of the Axially Moving String Using Space Feedforward and Feedback Controllers

Active vibration control of an axially moving string using space feedforward and feedback controllers is presented. Closed-form results for the transverse response of both the uncontrolled and controlled string are given in the s domain. The space feedforward controller is established by employing the idea of wave cancellation. The proposed control law indicates that vibration in the region downstream of the control force can be cancelled. With the space feedforward control, the mode shapes of the axially moving string are changed such that the free response tends to zero in the downstream region. An interesting physical interpretation is that the control force acts effectively as a holder (active support) which limits the vibration of the string to the upstream region and eliminates any vibration in the downstream region. Simulation results show that the response of the string to both sinusoidal and random excitations is suppressed by applying the space feedforward control. The feedback controller is introduced to attenuate the response of the string due to undesired disturbances in the downstream.
TORSION THEORIES FOR FINITE VON NEUMANN ALGEBRAS

ABSTRACT The study of modules over a finite von Neumann algebra &#x1d49c; can be advanced by the use of torsion theories. In this work, some torsion theories for &#x1d49c; are presented, compared, and studied. In particular, we prove that the torsion theory (T, P) (in which a module is torsion if it is zero-dimensional) is equal to both Lambek and Goldie torsion theories for &#x1d49c;. Using torsion theories, we describe the injective envelope of a finitely generated projective &#x1d49c;-module and the inverse of the isomorphism K 0(&#x1d49c;) → K 0 (&#x1d4b0;), where &#x1d4b0; is the algebra of affiliated operators of &#x1d49c;. Then the formula for computing the capacity of a finitely generated module is obtained. Lastly, we study the behavior of the torsion and torsion-free classes when passing from a subalgebra ℬ of a finite von Neumann algebra &#x1d49c; to &#x1d49c;. With these results, we prove that the capacity is invariant under the induction of a ℬ-module.
Perfect congruences on bisimple \omega -semigroups

A congruence $$\varepsilon $$ on a semigroup $$S$$ is perfect if for any congruence classes $$x\varepsilon $$ and $$y\varepsilon $$ their product as subsets of $$S$$ coincides (as a set) with the congruence class $$(xy)\varepsilon $$ . Perfect congruences on the bicyclic semigroup were found in Fortunatov (Algebra and Number Theory, Nalchik, vol 4, pp 93–98, 1979). Using the structure of bisimple $$\omega $$ -semigroups determined in Reilly (Proc Glasg Math Assoc 7:160–167, 1966) and the description of congruences on these semigroups found in Munn and Reilly (Proc Glasg Math Assoc 7:184–192, 1966) and Ault (Semigroup Forum 10:351–366, 1975), we obtain a complete characterization of perfect congruences on all bisimple $$\omega $$ -semigroups, substantially generalizing the above mentioned result of Fortunatov (Algebra and Number Theory, Nalchik, vol 4, pp 93–98, 1979).
Rademacher's infinite partial fraction conjecture is (almost certainly) false

In his book Topics in Analytic Number Theory, Hans Rademacher conjectured that the limits of certain sequences of coefficients that arise in the ordinary partial fraction decomposition of the generating function for partitions of integers into at most N parts exist and equal particular values that he specified. Despite being open for nearly four decades, little progress has been made towards proving or disproving the conjecture, perhaps in part due to the difficulty in actually computing the coefficients in question. In this paper, we present a recurrence (alias difference equation) which provides a fast algorithm for calculating the Rademacher coefficients, a large amount of data, direct formulae for certain collections of Rademacher coefficients, and overwhelming evidence against the truth of the conjecture. While the limits of the sequences of Rademacher coefficients do not exist (the sequences oscillate and attain arbitrarily large positive and negative values), the sequences do get very close to Rade...
Metal–insulator transition in a weakly interacting many-electron system with localized single-particle states

Abstract We consider low-temperature behavior of weakly interacting electrons in disordered conductors in the regime when all single-particle eigenstates are localized by the quenched disorder. We prove that in the absence of coupling of the electrons to any external bath dc electrical conductivity exactly vanishes as long as the temperature T does not exceed some finite value Tc. At the same time, it can be also proven that at high enough T the conductivity is finite. These two statements imply that the system undergoes a finite temperature metal-to-insulator transition, which can be viewed as Anderson-like localization of many-body wave functions in the Fock space. Metallic and insulating states are not different from each other by any spatial or discrete symmetries. We formulate the effective Hamiltonian description of the system at low energies (of the order of the level spacing in the single-particle localization volume). In the metallic phase quantum Boltzmann equation is valid, allowing to find the kinetic coefficients. In the insulating phase, T
Engineering aspects of geothermal development with emphasis on the Imperial Valley of California

This review was prepared in support of a geothermal planning activity of the County of Imperial. Engineering features of potential geothermal development are outlined. Acreage requirements for drilling and powerplants are estimated, as are the costs for wells, fluid transmission pipes, and generating stations. Rough scaling relationships are developed for cost factors as a function of reservoir temperature. Estimates are made for cooling water requirements, and possible sources of cooling water are discussed. Availability and suitability of agricultural wastewater for cooling are emphasized. The utility of geothermal resources for fresh water production in the Imperial Valley is considered.
ENANTIOSELECTIVE SYNTHESIS OF A TAXANE C-RING COMPONENT USING THE SCHULTZ ASYMMETRIC BIRCH REDUCTION METHODOLOGY

Abstract The asymmetric Birch reduction methodology has been used to develop two complementary routes to the taxane C-ring component in an enantioenriched form.
Quantum Formulas: A Lower Bound and Simulation

We show that Nechiporuk's method [I. Wegener, The Complexity of Boolean Functions, Teubner-Wiley, New York, 1987] for proving lower bounds for Boolean formulas can be extended to the quantum case. This leads to an $\Omega(n^2/\log^2 n)$ lower bound for quantum formulas computing an explicit function. The only known previous explicit lower bound for quantum formulas [A. Yao, Proceedings of 34th IEEE Symposium on Foundations of Computer Science, IEEE Computer Society Press, Los Alamitos, CA, 1993, pp. 352--361] states that the majority function does not have a linear-size quantum formula. We also show that quantum formulas can be simulated by Boolean circuits of almost the same size.
Convex relaxations of SE(2) and SE(3) for visual pose estimation

This paper proposes a new method for rigid body pose estimation based on spectrahedral representations of the tautological orbitopes of SE(2) and SE(3). The approach can use dense point cloud data from stereo vision or an RGB-D sensor (such as the Microsoft Kinect), as well as visual appearance data as input. The method is a convex relaxation of the classical pose estimation problem, and is based on explicit linear matrix inequality (LMI) representations for the convex hulls of SE(2) and SE(3). Given these representations, the relaxed pose estimation problem can be framed as a robust least squares problem with the optimization variable constrained to these convex sets. Although this formulation is a relaxation of the original problem, numerical experiments indicates that it is indeed exact - i.e. its solution is a member of SE(2) or SE(3) - in many interesting settings. We additionally show that this method is guaranteed to be exact for a large class of pose estimation problems.
Log canonical thresholds of del Pezzo surfaces in characteristic p

The global log canonical threshold of each non-singular complex del Pezzo surface was computed by Cheltsov. The proof used Kollar–Shokurov’s connectedness principle and other results relying on vanishing theorems of Kodaira type, not known to be true in finite characteristic. We compute the global log canonical threshold of non-singular del Pezzo surfaces over an algebraically closed field. We give algebraic proofs of results previously known only in characteristic 0. Instead of using of the connectedness principle we introduce a new technique based on a classification of curves of low degree. As an application we conclude that non-singular del Pezzo surfaces in finite characteristic of degree lower or equal than 4 are K-semistable.
Color scanner characterization with scan targets of different media types and printing mechanisms

Due to the increasing popularity and afford ability of color imaging devices, color characterization for these devices becomes an important subject. In other words, a set of color profile(s) needs to be generated for each device to transform the device dependent color space to a device independent one. This paper will concentrate on color characterization of scanners.© (2000) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
The effects of alternative fiscal policies on the intertemporal government budget constraint

Abstract This article presents the effects of alternative fiscal policies on the intertemporal government budget constraint when the time horizon of the policy maker varies. I show that the wealth effect associated with cuts in the skill-adjusted labor income tax rate improves the intertemporal budget balance, whereas the intertemporal substitution effect associated with the physical capital income tax rate deteriorates the intertemporal budget. Under plausible parameter values, the tax rate on skill-adjusted labor income cannot by itself balance the intertemporal budget at all horizons.
Gorenstein algebras presented by quadrics

We establish restrictions on the Hilbert function of standard graded Gorenstein algebras with only quadratic relations. Furthermore, we pose some intriguing conjectures and provide evidence for them by proving them in some cases using a number of different techniques, including liaison theory and generic initial ideals.
Limits of dense graph sequences

We show that if a sequence of dense graphs G"n has the property that for every fixed graph F, the density of copies of F in G"n tends to a limit, then there is a natural ''limit object,'' namely a symmetric measurable function W:[0,1]^2->[0,1]. This limit object determines all the limits of subgraph densities. Conversely, every such function arises as a limit object. We also characterize graph parameters that are obtained as limits of subgraph densities by the ''reflection positivity'' property. Along the way we introduce a rather general model of random graphs, which seems to be interesting on its own right.
Flight Investigation of the Influence of Turbulence on Longitudinal Flying Qualities

Flight evaluations using a variable stability airplane were made to determine the independent and interacting effects of turbulence disturbances and longitudinal dynamics on flying qualities for the ILS approach task. Turbulence was described in terms of the rms magnitudes of pitch and heave disturbances and the bandwidth of the turbulence power spectrum. Variations in dynamics included the frequency and damping of the short-period mode and the slope of the lift curve. Trends in pilot rating obtained in the test program with variations in turbulence disturbances and airplane dynamics are explained in terms of measures of precision of task performance and the pilot's control activity derived from time histories of the ILS approach.
Lead-rare earth-chalcogenides grown by molecular beam epitaxy☆

Abstract Mid-IR diode laser technology has been revolutionized by the development of lead-rare earth-chalcogenide alloys. These devices cover the 3–30 μm wavelength range and have typically operated at temperatures below 80 K. Recent PbEuSeTe-PbTe quantum well devices operate at up to 175 K continuous wave (CW), and up to 270 K pulsed. The attainment of these high operating temperatures is triggering the development of new spectroscopic applications. These advances will be reviewed as well as the growth and materials issues of these new alloys.
Mechanistic insights into the opening of epoxides with trimethylsilyl cyanide - zinc iodide

Abstract endo -2,3-Epoxy-1,7,7-trimethylbicyclo[2.2.1]heptane reacted with trimethylsilyl cyanide in the presence of zinc iodide to produce a complex mixture of products. The major product, anti -7-trimethylsiloxy- endo -2,3,3-trimethyl- exo -2-isocyanobicyclo[2.2.1]heptane was obtained in 72% yield. In addition, eight other products were identified in yields ranging from 10% to 1%. All of the products could be rationalized on the basis of initial generation of a carbocationic intermediate.
Grand challenges to computational science

Abstract Computational Science is at the very beginning of centuries of growth, comparable to the four centuries of experimental advances since Galileo. The Grand Challenges to Computational Science are unsolved scientific problems of extraordinary breadth and importance which will demand continuing computational advances throughout the forthcoming computational era. Supercomputers can be used to see phenomena not directly accessible to experiment in key scientific and engineering areas such as atmospheric science, astronomy, materials science, molecular biology, aerodynamics, and elementary particle physics. However, the benefits of supercomputers will be greatly increased if some major difficulties are overcome. In this paper, I address some of the tougher requirements on current grand challenge research to ensure that it has enduring value. The problems of algorithm development, error control, software productivity, and the fostering of technological advances are especially important.