cssi/SciSciGPT-SciSciNet huggingface dataset:
First to market is not everything: an analysis of preferential attachment with fitness

The design of algorithms on complex networks, such as routing, ranking or recommendation algorithms, requires a detailed understanding of the growth characteristics of the networks of interest, such as the Internet,the web graph, social networks or online communities. To this end, preferential attachment, in which the popularity (or relevance) of a node is determined by its degree, is a well-known and appealing random graph model, whose predictions are in accordance with experiments on the web graph and several social networks. However, its central assumption, that the popularity of the nodes dependsonly on their degree, is not a realistic one, since every node has potentially some intrinsic quality which can differentiate its attractiveness from other nodes with similar degrees.In this paper, we provide a rigorous analysis of preferential attachment with fitness, suggested by Bianconi and Barabasi and studied by Motwani and Xu, in which the degree of a vertex is scaled by its quality to determine its attractiveness. Including quality considerations in the classical preferential attachment model provides a much more realistic description of many complex networks, such as the web graph, and allows toobserve a much richer behavior in the growth dynamics of these networks. Specifically, depending on the shape of the distributionfrom which the qualities of the vertices are drawn, we observe three distinct phases, namely a first-mover-advantage phase, afit-get-richer phase and an innovation-pays-offphase. We precisely characterize the properties of the quality distribution that result in each of these phases and we computethe exact growth dynamics for each phase. The dynamics provide rich information about the quality of the vertices, which can bevery useful in many practical contexts, including ranking algorithms for the web, recommendation algorithms, as well as thestudy of social networks.
Preoperative Evaluation of the Oncology Patient

This review focuses on the unique perioperative concerns of patients with cancer undergoing surgery. Importantly, not all surgical procedures are intended as cures: some patients who have cancer also undergo surgery for noncancer issues. Also, many of these patients have undergone prior chemotherapy and/or radiation therapy that can introduce perioperative concerns. These previous treatments, unique to patients with cancer, can adversely affect their cardiovascular, pulmonary, gastrointestinal, renal, and endocrine systems. This article also summarizes many important effects of a wide variety of chemotherapy agents in use today.
Dispersed Constituency Democracy: Deterritorializing Representation to Reduce Ethnic Conflict

In multiethnic and multi-religious democracies, the chronic danger is that candidates will engage in “identity politics,” appealing to one locally preponderant ethnic group against other groups. The usual formulas for composing multiethnic democracies—ethnic federalism and/or proportional representation—often exacerbate the problem, ethnicizing political campaigns and carving up the national legislature into ethnic blocs, each beholden only to its own group. An alternative approach—what I call “dispersed constituency democracy”—is to match each legislative seat with a constituency that reflects the overall ethnic composition of the society in question, so as to encourage candidates to reach across ethnic divisions rather than play to locally preponderant ones. I propose a simple way to do this, and explore the likely consequences for national electoral campaigns and legislative dynamics over a range of demographic circumstances. I also consider supplemental devices for protecting minority rights that woul...
Alternative Synthesis of Tadalafil: PDE5 Inhibitor

Abstract Two-step alternative synthesis of tadalafil (1) is described. The synthesis features Pictet–Spengeler type reaction and DCC (N,N′-dicyclohexylcarbodiimide)/HOBt (N-hydroxybenzotriazole)–mediated double amidation employing sarcosine ethyl ester hydrochloride.
Does Weather Actually Affect Tipping? An Empirical Analysis of Time Series Data

Prior literature has found evidence that pleasant weather (namely, sunshine) leads to higher tipping rates, presumably because it improves the moods of either servers or patrons. However, studies examining the relationship between pleasant weather and tipping behavior have involved relatively small samples of participants and daily observations. In addition, only one such study (Cunningham, 1979) used actual weather data to examine this relationship. We address these shortcomings by testing empirically the weather–tipping relationship on 2 years of actual sales data from a busy restaurant. We found no statistically significant relationship between sunshine and tipping. Tipping appears to be better explained as an institutional standard or norm, rather than as a prosocial behavior that can be modulated by weather-induced changes in mood.
Environmental Issues in Russia

This review examines the literature available on the state of the environment and environmental protection in the Russian Federation. As the largest country on Earth, rich in natural resources and biodiversity, Russia’s problems and policies have global consequences. Environmental quality and management are influenced by the legacy of Soviet economic planning and authoritarian governance, as well as by Russia’s post-Soviet economic recession and current strategies of economic development. Russia achieved a reduction in some pollutants owing to the collapse of industrial production in the 1990s, but many environmental indicators suggest growing degradation. Russia has signed on to a number of international environmental agreements, but its record on implementation is mixed, and it discourages environmental activism. Scholarship on the Russian environment is a limited, but growing, field, constrained by challenges of data availability, yet it offers great potential for testing scientific and social scientific hypotheses.
Viscoplastic Constitutive Modeling of Anisotropic Damage Under Nonproportional Loading

Based on the theory of damage mechanics, a viscoplastic constitutive modeling of anisotropic damage for the prediction of forming limit curve (FLC) is developed. The model takes into account the effect of rotation of principal damage coordinates on the deformation and damage behaviors. With the aid of the damage viscoplastic potential, the damage evolution equations are established. Based on a proposed damage criterion for localized necking, the model is employed to predict the FLC of aluminum 6111-T4 sheet alloy. The predicted results agree well with those determined experimentally.
The Big Crunch

The following article is an edited version of a plenary lecture given at Pittcon in New Orleans on March 8, 1995. Previous versions of this article have been published as "Scientific Ph.D. Problems," American Scholar, 62 (1993), and "Scientific Elites and Scientific Illiterates," Ethics, Values and the Promise of Science, Forum Proceedings, Sigma Xi, The Science Research Society (February 25--26, 1993) p. 61, and Engineering and Science 56 (Spring 1993) p. 22. David Goodstein is vice provost, professor of physics and applied physics, and the Frank J. Gilloon Distinguished Teaching and Service Professor at the California Institute of Technology.
Dependability and Performance Evaluation of Intrusion-Tolerant Server Architectures

In this work, we present a first effort at quantitatively comparing the strengths and limitations of various intrusion-tolerant server architectures. We study four representative architectures, and use stochastic models to quantify the costs and benefits of each from both the performance and dependability perspectives. We present results characterizing throughput and availability, the effectiveness of architectural defense mechanisms, and the impact of the performance versus dependability tradeoff. We believe that the results of this evaluation will help system architects to make informed choices for building more secure and survivable server systems.
On the Enlargement of the Normal Congenitally Solitary Kidney

Objective To determine the anatomy of the normal congenitally solitary kidney and to complement an earlier investigation of the major functional parameters of congenitally and acquired normal solitary kidneys. Materials and methods A healthy congenitally solitary kidney was compared anatomically with a normal control kidney from an equal pair in a man of similar height and age. Results The solitary kidney was about 1.8 times heavier than the control; the diameter of its glomeruli and convoluted tubules were similar to those of the control kidney but there were twice as many glomeruli in the solitary kidney than in the control. The total mass of glomeruli, as a percentage of the renal mass (about 5%), was the same for both kidneys and essentially similar to that for mammals in general. However, the total mass of glomeruli as a percentage of cortical mass was considerably greater in the congenitally solitary kidney than in the control, suggesting a relative deficit of convoluted tubular mass in the solitary kidney. Conclusion The normal congenitally solitary kidney is hyperplastic, i.e. there are more elements (nephrons), and apparently not hypertrophic, i.e. having larger nephrons.
Cauchy-type integrals in several complex variables

We present the theory of Cauchy–Fantappie integral operators, with emphasis on the situation when the domain of integration, , has minimal boundary regularity. Among these operators we focus on those that are more closely related to the classical Cauchy integral for a planar domain, whose kernel is a holomorphic function of the parameter . The goal is to prove estimates for these operators and, as a consequence, to obtain estimates for the canonical Cauchy–Szego and Bergman projection operators (which are not of Cauchy–Fantappie type).
Future applications of expert systems for the evaluation of energy resources

The loss of professional experience and expertise in the domain of the earth sciences may prove to be one of the most serious outcomes of the boom-and-bust cyclic nature of the volatile energy and mining industries. Promising new applications of powerful computer systems, known as ''expert systems'' or ''knowledge-based systems,'' are predicted for use in the earth sciences. These systems have the potential capability to capture and preserve the invaluable knowledge basis essential to the evaluation of U.S. energy and mineral resources.
Photon counting for Bragg spectroscopy of quantum gases

We demonstrate a photon-counting technique for detecting Bragg excitation of an ultracold gas of atoms. By measuring the response of the light field to the atoms, we derive a signal independent of traditional time-of-flight atom-imaging techniques. With heterodyne detection we achieve photon shot-noise limited detection of the amplification or depletion of one of the Bragg laser beams. Photon counting for Bragg spectroscopy will be useful for strongly interacting gases where atom-imaging detection fails. In addition, this technique provides the ability to resolve the evolution of excitations as a function of pulse duration.
Money Demand in Australia: Which Monetary Aggregate Matters?

We examine the long-run relation linking the demand for money in Australia to economic activity and the interest rate for an extended period from 1976 to 2010. Using the Johansen cointegration test, we test the relationship for three measures of monetary aggregate – currency, M1 and M3. The results provide evidence for a long-run equilibrium relation linking the demand for M1 to economic activity and the interest rate. The relationship is stable with unitary income elasticity and sizeable interest rate semi-elasticity. The evidence may open a new debate for the Reserve Bank of Australia to look into the use of M1 as a tool in implementing its monetary policy after a long-time abandonment of M3.
Distortion-rate functions for quantized compressive sensing

We study the average distortion introduced by quantizing compressive sensing measurements. Both uniform quantization and non-uniform quantization are considered. The asymptotic distortion-rate functions are obtained when the measurement matrix belongs to certain random matrix ensembles. Furthermore, we adapt two well-known compressive sensing reconstruction algorithms to accommodate the quantization effects. The performance of the new reconstruction methods is assessed through extensive computer simulations.
Catalysis of the Michael Addition Reaction by Late Transition Metal Complexes of BINOL-Derived Salens

Salen metal complexes incorporating two chiral BINOL moieties have been synthesized and characterized by X-ray crystallography. The X-ray structures show that this new class of Ni-BINOL-salen catalysts contains an unoccupied apical site for potential coordination of an electrophile and naphthoxides that are independent from the Lewis acid center. These characteristics allow independent alteration of the Lewis acidic and Bronsted basic sites. These unique complexes have been shown to catalyze the Michael reaction of dibenzyl malonate and cyclohexenone with good selectivity (up to 90% ee) and moderate yield (up to 79% yield). These catalysts are also effective in the Michael reaction between other enones and malonates. Kinetic data show that the reaction is first order in the Ni·Cs-BINOL-salen catalyst. Further experiments probed the reactivity of the individual Lewis acid and Bronsted base components of the catalyst and established that both moieties are essential for asymmetric catalysis. All told, the da...
Protective effects of veskamide, enferamide, becatamide, and oretamide on H2O2-induced apoptosis of PC-12 cells

Abstract Veskamide, enferamide, becatamide, and oretamide are phenolic amides whose analogues are found in plants. In this study, the four amides were prepared by chemical synthesis and their protective effects on H 2 O 2 -induced apoptosis in PC-12 cells were investigated. The syntheses were relatively simple and the yields were more than 43%. Using NMR spectroscopic methods, the chemical structures of veskamide, enferamide, becatamide, and oretamide were confirmed. The decreasing order of the protective effects on H 2 O 2 -induced apoptosis was becatamide > enferamide ≥ oretamide > veskamide. In fact, becatamide suppressed H 2 O 2 -induced mitochondrial membrane depolarization in a dose-dependent manner. At the concentration of 10 μM, becatamide maintained mitochondrial membrane depolarization at 16% compared to 51% in H 2 O 2 -treated PC-12 cells ( P 2 O 2 -induced caspase-9 activation and caspase-independent chromatin condensation by 68% ( P P 2 O 2 -induced apoptosis of PC-12 cells via protecting mitochondrial membrane integrity, thereby suppressing caspase-9 activation and chromatin condensation.
Ultrafast carrier dynamics in semiconductor nanowires

Ultrafast wavelength-tunable optical measurements on semiconductor nanowires allow us to independently probe the dynamics of electrons, holes, and defect states. These investigations reveal the influence of two-dimensional confinement on carrier dynamics in these nanosystems.
Mitsunobu Reactions Catalytic in Phosphine and a Fully Catalytic System

The Mitsunobu reaction is renowned for its mild reaction conditions and broad substrate tolerance, but has limited utility in process chemistry and industrial applications due to poor atom economy and the generation of stoichiometric phosphine oxide and hydrazine by-products that complicate purification. A catalytic Mitsunobu reaction using innocuous reagents to recycle these by-products would overcome both of these shortcomings. Herein we report a protocol that is catalytic in phosphine (1-phenylphospholane) employing phenylsilane to recycle the catalyst. Integration of this phosphine catalytic cycle with Taniguchi’s azocarboxylate catalytic system provided the first fully catalytic Mitsunobu reaction.
Universal scheduling for networks with arbitrary traffic, channels, and mobility

We extend stochastic network optimization theory to treat networks with arbitrary sample paths for arrivals, channels, and mobility. The network can experience unexpected link or node failures, traffic bursts, and topology changes, and there are no probabilistic assumptions describing these time varying events. Performance of our scheduling algorithm is compared against an ideal T-slot lookahead policy that can make optimal decisions based on knowledge up to T-slots into the future. We develop a simple non-anticipating algorithm that provides network throughput-utility that is arbitrarily close to (or better than) that of the T-slot lookahead policy, with a tradeoff in the worst case queue backlog kept at any queue. The same policy offers even stronger performance, closely matching that of an ideal infinite lookahead policy, when ergodic assumptions are imposed. Our analysis uses a sample path version of Lyapunov drift and can be applied to optimize time averages in general classes of time-varying systems.
System thinking: educating t-shaped software engineers

With respect to system thinking, a T-shaped person is one who has technical depth in at least one aspect of the system's content, and a workable level of understanding of a fair number of the other system aspects. Many pure computer science graduates are strongly I-shaped, with a great deal of depth in software technology, but little understanding of the other disciplines involved in such areas as business, medicine, transportation, or Internets of Things. This leaves them poorly prepared to participate in the increasing numbers of projects involving multi-discipline system thinking, and in strong need of software skills. We have developed and evolved an MS-level software engineering curriculum that enables CS majors to become considerably more T-shaped than when they entered. It includes courses in software management and economics, human-computer interaction, embedded software systems, systems and software requirements, architecture, and V&V, and a two-semester, real-client team project course that gives students experience in applying these skills. We find via feedback on the students' internships and job experiences that they and their employers have high rates of success in job offers and job performance.
Capacity of Ultra Wide Band Wireless Ad Hoc Networks

Throughput capacity is a critical parameter for the design and evaluation of ad-hoc wireless networks. Assuming a fixed per node transmission capability of T bits per second at a fixed range, it has been shown [1] that the information theoretic uniform throughput capacity per node r(n) is Theta (T/radicn log n), a decreasing function of node density n. However we consider an alternate communication model, with each node constrained to a maximum transmit power P0 and capable of utilizing W Hz of bandwidth. Under the limiting case W rarr infin, such as in ultra wide band (UWB) networks, we show that the uniform throughput per node is O ((n log n)alpha-1/2 (upper bound) and Omega(n(alpha-1)/2(log n(alpha+1)/2) (achievable lower bound). Thus we demonstrate that the throughput increases with node density n, in contrast to previously published results. The capacity problem is also considered from an optimization theoretic perspective. The novel information theoretic capacity bound is compared to the network optimization results, demonstrating its practical applicability to UWB networks. The dramatic effect of the UWB physical layer on the capacity justifies the promise of UWB as a physical layer technology for ad-hoc networks.
Dynamics of fingering convection I: Small-scale fluxes and large-scale instabilities

(Received ?? and in revised form ??) Double-diffusive instabilities are often invoked to explain enhanced transport in stablystratified fluids. The most-studied natural manifestation of this process, fingering convection, commonly occurs in the ocean’s thermocline and typically increases diapycnal mixing by two orders of magnitude over molecular diffusion. Fingering convection is also often associated with structures on much larger scales, such as thermohaline intrusions, gravity waves and thermohaline staircases. In this paper, we present an exhaustive study of the phenomenon from small to large scales. We perform the first three-dimensional simulations of the process at realistic values of the heat and salt diffusivities and provide accurate estimates of the induced turbulent transport. Our results are consistent with oceanic field measurements of diapycnal mixing in fingering regions. We then develop a generalized mean-field theory to study the stability of fingering systems to large-scale perturbations, using our calculated turbulent fluxes to parameterize small-scale transport. The theory recovers the intrusive instability, the collective instability, and the instability as limiting cases. We find that the fastest-growing large-scale mode depends sensitively on the ratio of the background gradients of temperature and salinity (the density ratio). While only intrusive modes exist at high density ratios, the collective and -instabilities dominate the system at the low density ratios where staircases are typically observed. We conclude by discussing our findings in the context of staircase formation theory.
Mapping climatic temperature changes in the ocean with acoustic tomography: navigational requirements

In eddy-resolving hydrodynamic models, first-mode baroclinic Rossby waves linked to El Nino/Southern Oscillation are the dominant features which change basin-wide temperatures below the seasonal thermocline in the northeast Pacific at periods less than a decade. Simulations are carried out in which Rossby waves are mapped using acoustic tomography. Based on the model which propagated these waves, a Kalman filter is used to map temperature signals for a year. The modeled data are taken from a dense network of acoustic tomography sections. At 300-m depth, where the temperature perturbations associated with Rossby waves are about /spl plusmn/1/spl deg/C, 80% to 90% of the model variance is accounted for with tomographic estimates. The corresponding standard deviations of the estimates are less than 0.1/spl deg/C at 400-km resolution. About 80% of the model variance is accounted for with tomography when the navigational errors of the sources and receivers are as poor as one kilometer. Consequently, it may be unnecessary to accurately navigate actual tomographic instruments to map climate change. Modeling results are insensitive to: 1) a reduction in data due to a significant number of instruments which fail; 2) whether the instruments are mobile or fixed; 3) the detailed trajectories of mobile receivers; 4) the shape of the a priori spectrum of ocean fluctuations; 5) the corrections to the acoustic travel-time biases; and 6) the errors in the sound-speed algorithm. In basin-scale arrays, the modeled variance of acoustic travel time depends on the horizontal wavenumber of temperature as k/sup -5.5/. Because sound has little sensitivity to small wavelengths, modeled Rossby waves can be mapped in a day from a few sources and of order ten receivers. The results only depend on the model having large scales in space and time.
The Physics of the Colloidal Glass Transition

As one increases the concentration of a colloidal suspension, the system exhibits a dramatic increase in viscosity. Beyond a certain concentration, the system is said to be a colloidal glass; structurally, the system resembles a liquid, yet motions within the suspension are slow enough that it can be considered essentially frozen. For several decades, colloids have served as a valuable model system for understanding the glass transition in molecular systems. The spatial and temporal scales involved allow these systems to be studied by a wide variety of experimental techniques. The focus of this review is the current state of understanding of the colloidal glass transition, with an emphasis on experimental observations. A brief introduction is given to important experimental techniques used to study the glass transition in colloids. We describe features of colloidal systems near and in glassy states, including increases in viscosity and relaxation times, dynamical heterogeneity and ageing, among others. We also compare and contrast the glass transition in colloids to that in molecular liquids. Other glassy systems are briefly discussed, as well as recently developed synthesis techniques that will keep these systems rich with interesting physics for years to come.
Roof Strength and Injury Risk in Rollover Crashes

Objective: Previous studies have reported that roof strength as measured in FMVSS 216 is unrelated to occupant injury risk in actual rollovers. However, those studies did not control for important confounding factors. The present study reevaluated roof strength and injury risk using a single class of vehicles with similar driver and vehicle usage characteristics in the expectation that some potential confounders will be controlled by this focused analysis. Alternative roof strength measures also were examined in case strength-to-weight ratio (SWR) at 5 inches, the measure in FMVSS 216, is not the best measure. Methods: Eleven midsize SUV roof designs were crushed according to FMVSS 216 protocol. Force was measured continuously, and the maximum force and the amount of energy used to achieve crush of 2, 5, and 10 inches were recorded; these six measures of roof strength were evaluated both directly and after normalization for vehicle weight. After controlling for other potentially confounding variables, log...
Neurophysiological Studies in Batten's Disease

SUMMARY Twenty cases of presumed or proven juvenile amaurotic familial idiocy (Batten's disease) have been studied neurophysiologically. A characteristic eeg pattern was observed in 19 of these patients, photic activation in 7, and an abnormal evoked cerebral potential to median nerve stimulation in 5 of 6 cases so tested. The clinical diagnosis of Batten's disease may be supported by eeg, erg, and evoked potential studies. RESUME Etude neurophysiologique des idioties amaurotiques familiales 20 cas d'idiotie amaurotique familiale juvenile presumee ou prouvee ont eteetudies neurophysiologiquement. Un aspect eeg caracteristique a ete note chez 19 de ces sujets, une activation par SLI dans 7 cas et des potentiels cerebraux evoques anormaux par stimulation du nerf median dans 5 des 6 cas etudies. Le diagnostic clinique d'idiotie amaurotique familiale peut done etre confirme par eeg, erg (electroretinogramme) et etude des potentiels evoques. ZUSAMMENFASSUNG Neurophysiologische Untersuchungen bei der Batten schen Krankheit Zwanzig Falle von angenommener oder bewiesener juveniler amaurotischer familiarer Idiotie (Batten sche Krankheit) wurden neurophysiologisch untersucht. Ein charakteristischer eeg-Verlauf wurde bei 19 dieser Patienten beobachtet, bei 7 eine photische Aktivierung und ein abnormes cerebrales Reizpotential nach Stimulation des N. medianus bei 5 von 6 derartiguntersuchten Fallen. Die klinische Diagnose der Batten's chen Krankheit kann durch eeg, erg und durch stimulierte Potentialuntersuchungen gestutzt werden. RESUMEN Estudios neurofisiologicos en la enfermedad de Batten Se han estudiado neurofisiologicamente 20 casos presumidos o comprobados de idiocia amaurotica familiar juvenil (enfermedad de Batten). Se observo un trazado eeg caracteristico en 19 de estos pacientes, activation fotica en 7 casos y un potencial evocado cerebral anormal a la estimulacion del nervio mediano en 5 de los 6 casos explorados. El diagnostico clinico de la enfermedad de Batten debe venir apoyado por el eeg, erg y estudios de potenciales evocados.
Component-Mode-Based Reduced Order Modeling Techniques for Mistuned Bladed Disks—Part I: Theoretical Models

Component mode synthesis (CMS) techniques are widely used for dynamic analyses of complex structures. Significant computational savings can be achieved by using CMS since a modal analysis is performed on each component structure (substructure). Mistuned bladed disks are a class of structures for which CMS is well suited. In the context of blade mistuning, it is convenient to view the blades as individual components, while the entire disk may be treated as a single component. Individual blade mistuning may then be incorporated into the CMS model in a straightforward manner. In this paper, the Craig-Bampton (CB) method of CMS is formulated specifically for mistuned bladed disks, using a cyclic disk description. Then a novel secondary modal analysis reduction technique (SMART) is presented: a secondary modal analysis is performed on a CB model, yielding significant further reduction in model size. In addition, a straightforward non-CMS method is developed in which the blade mistuning is projected onto the tuned system modes. Though similar approaches have been reported previously, here it is generalized to a form that is more useful in practical applications. The theoretical models are discussed and compared from both computational and practical perspectives. It is concluded that using SMART, based on a CB model, has tremendous potential for highly efficient, accurate modeling of the vibration of mistuned bladed disks.
Spin wave stability of the ferromagnetic state for a narrow s band

A variational method is used to improve upon the random phase approximation result for the energy of a long wavelength spin wave in the ferromagnetic state of a narrow s band. The effect of including correlation is to restrict the range in which the effective exchange integral is positive. The results are consistent with the findings of Nagaoka for the case of a nearly half-filled band.
Legacies of Derrida: Anthropology

This article considers the legacies of Jacques Derrida in and for Anglo-American sociocultural anthropology. It begins with a survey of Derrida's own engagement with themes that have historically been foundational to the field: (a) the critique of sign theory and, with it, the questions of language and law in Levi-Straussian structuralism; (b) the question of the unconscious; (c) the critique of the performative and its consequences for the idea of ritual; (d) the rereading of Marcel Mauss's concept of the gift, and of economy more generally; and (e) the analysis of the metaphysical basis of law, in both religious and ostensibly secular formations. It then considers the state of the field at the time when it was being infused with different forms of poststructuralism and explores the competing claims made by these discourses in relation to deconstruction. Finally, after tracing the convergences and divergences between Derridean deconstruction and theory in sociocultural anthropology, it treats two main ex...
Casimir forces in the time domain: Theory

We present a method to compute Casimir forces in arbitrary geometries and for arbitrary materials based on the finite-difference time-domain (FDTD) scheme. The method involves the time evolution of electric and magnetic fields in response to a set of current sources, in a modified medium with frequency-independent conductivity. The advantage of this approach is that it allows one to exploit existing FDTD software, without modification, to compute Casimir forces. In this paper, we focus on the derivation, implementation choices, and essential properties of the time-domain algorithm, both considered analytically and illustrated in the simplest parallel-plate geometry.
A TECHNICAL EFFICIENCY ANALYSIS OF PENNSYLVANIA DAIRY FARMS

This study estimates technical efficiency (TE) using a stochastic production frontier based on a randomly selected cross-sectional sample of Pennsylvania dairy farms. The Cobb-Douglas functional form is a suitable model in the estimation. Estimates of mean technical efficiency and appropriate technical efficiency of individual farms are computed and compared under three distributional assumptions of the efficiency disturbance terms. Maximum likelihood techniques are used for the estimation of the stochastic frontier. The technical efficiency measure is further broken down by different farm size.
Glass strengthening by polymer-derived ceramic coatings

Polysilazane-derived ceramic coatings in the form of thin films (0.1 to 4 μm) — fabricated by dipcoating soda-lime rods with preceramic polymer solutions, followed by pyrolysis — increased the strength of the glass rods. Strengths up to 414 ± 57 MPa were obtained, 2.3 and 3.3 times higher than the strengths of uncoated/annealed and as-received rods, respectively. As-received coated glass was stronger than coated annealed glass. Microstructural damage was not observed in the optimal coatings.
WEIGHTED AND TWO-STAGE LEAST SQUARES ESTIMATION OF SEMIPARAMETRIC TRUNCATED REGRESSION MODELS

This paper provides a root-n consistent, asymptotically normal weighted least squares estimator of the coe‐cients in a truncated regression model. The distribution of the errors is unknown and permits general forms of unknown heteroskedasticity. Also provided is an instrumental variables based two stage least squares estimator for this model, which can be used when some regressors are endogenous, mismeasured, or otherwise correlated with the errors. A simulation study indicates the new estimators perform well in flnite samples. Our limiting distribution theory includes a new asymptotic trimming result addressing the boundary bias in flrst stage density estimation without knowledge of the support boundary.
Integral Non-commutative Spaces

Abstract A non-commutative space X is a Grothendieck category Mod X. We say X is integral if there is an indecomposable injective X-module E X such that its endomorphism ring is a division ring and every X-module is a subquotient of a direct sum of copies of E X. A noetherian scheme is integral in this sense if and only if it is integral in the usual sense. We show that several classes of non-commutative spaces are integral. We also define the function field and generic point of an integral space and show that these notions behave as one might expect.
Polar Faculae During the Interval 1906–1975

The previous studies by the author (1964, 1966), in which the numbers of faculas at the poles of the sun were used to estimate the strengths of the polar magnetic fields from 1906-1964, have been extended to the period 1964-1975 with the help of space-based observations of the sun and its environment. A rapid increase in the strength of the field at the south pole was observed in 1973 during the Skylab mission; a gradual increase in the north pole field occurred during 1972 and 1973. With the exception of a brief interval in 1959, the south pole field has been weaker during the past magnetic cycle than in any cycle since 1906.
Técnicas de Neutralización: una teoría de la delincuencia

This article presents evidences that suggest that criminals do not usually approve of delinquency. They end in the delinquency through certain“neutralization techniques”. Although they believe delinquency is bad, they say that their actions are justifiable for different types of reasons. These justifications are used before the deliquent action, making it possible by the neutralization of the individuals' beliefs that they are bad.
The Lick-Carnegie Exoplanet Survey: A Saturn-Mass Planet in the Habitable Zone of the Nearby M4V Star HIP 57050

Precision radial velocities (RV) from Keck/HIRES reveal a Saturn-mass planet orbiting the nearby M4V star HIP 57050. The planet has a minimum mass of Msin i ~ 0.3 M J, an orbital period of 41.4 days, and an orbital eccentricity of 0.31. V-band photometry reveals a clear stellar rotation signature of the host star with a period of 98 days, well separated from the period of the RV variations and reinforcing a Keplerian origin for the observed velocity variations. The orbital period of this planet corresponds to an orbit in the habitable zone of HIP 57050, with an expected planetary temperature of ~230 K. The star has a metallicity of [Fe/H] = 0.32 ± 0.06 dex, of order twice solar and among the highest metallicity stars in the immediate solar neighborhood. This newly discovered planet provides further support that the well-known planet-metallicity correlation for F, G, and K stars also extends down into the M-dwarf regime. The a priori geometric probability for transits of this planet is only about 1%. However, the expected eclipse depth is ~7%, considerably larger than that yet observed for any transiting planet. Though long on the odds, such a transit is worth pursuing as it would allow for high quality studies of the atmosphere via transmission spectroscopy with Hubble Space Telescope. At the expected planetary effective temperature, the atmosphere may contain water clouds.
Optimal Load Distribution for Multiple Heterogeneous Blade Servers in a Cloud Computing Environment

Given a group of heterogeneous blade servers in a cloud computing environment or a data center of a cloud computing provider, each having its own size and speed and its own amount of preloaded special tasks, we are facing the problem of optimal distribution of generic tasks over these blade servers, such that the average response time of generic tasks is minimized. Such performance optimization is important for a cloud computing provider to efficiently utilize all the available resources and to deliver the highest quality of service. We develop a queueing model for a group of heterogeneous blade servers, and formulate and solve the optimal load distribution problem of generic tasks for multiple heterogeneous blade servers in a cloud computing environment in two different situations, namely, special tasks with and without higher priority. Extensive numerical examples and data are demonstrated and some important observations are made. It is found that server sizes, server speeds, task execution requirement, and the arrival rates of special tasks all have significant impact on the average response time of generic tasks, especially when the total arrival rate of generic tasks is large. It is also found that the server size heterogeneity and the server speed heterogeneity do not have much impact on the average response time of generic tasks. Furthermore, larger (smaller, respectively) heterogeneity results in shorter (longer, respectively) average response time of generic tasks.
Channel Optical Waveguides and Directional Couplers in GaAs–Imbedded and Ridged

Two-channel imbedded directional couplers were fabricated with proton implantation, yielding complete light transfer in 2 mm. Ridged channel guides were fabricated by ion-micromachining epitaxial layers, and a method of directional coupling was demonstrated.
A study of near to far fields of JPL Deep Space Network (DSN) antennas for RFI analysis

This paper addresses the issue of calculating the gain and power distribution of DSN antennas in the Fresnel (middle zone) and Fraunhofer (far zone) as a function of the distance from the DSN antenna and the off-boresight angle. Calculating the near and mid fields of DSN antennas are of interest in the receive mode where the transmitting signals from nearby flying objects such as helicopters and airplanes transmitting in the DSN frequency range, interfere with the operation of sensitive RF receiving system of the DSN antennas, and in the transmit mode where fields from high-powered DSN antennas interfere with receivers on nearby flying objects such as helicopters or other systems. Computing the exact fields of a large DSN antenna is, in general, a very complicated and arduous task. Even far-field calculations, which are less complicated compared to near and mid zone fields, take considerable computer time. These calculations become even more involved and time-consuming in very near field and back field regions. We provide two approaches for addressing the radio frequency interference (RFI) issue. In this paper, actual fields in mid and far zones are calculated using a relatively simple formulation that is accurate enough for the purposes of RFI analysis. In a future paper, we study and develop simple reference models that provide upper limit bounds or envelopes of the far field patterns as a function of the antenna diameter and frequency, which can be used for obtaining the field at any given point in space.
Early childhood development in Latin America and the Caribbean

There is considerable evidence that young children in many developing countries suffer from profound deficits in nutrition, health, fine and gross motor skills, cognitive development, and socio-emotional development. Early childhood development (ECD) outcomes are important markers of the welfare of children. In addition, the deleterious effects of poor outcomes in early childhood can be long-lasting, affecting school attainment, employment, wages, criminality, and measures of social integration of adults. This paper considers the theoretical case to be made for investments in early childhood, selectively reviews the literature on the impact of ECD programs in the United States, discusses the evidence from Latin America and the Caribbean, and makes suggestions for future research. The focus is on the relation between outcomes in early childhood and measures of household socioeconomic status, child health, and parenting practices, as well as on the impact of specific policies and programs. The knowledge base on early childhood outcomes is still thin in Latin America and the Caribbean. There are therefore very high returns to comparative descriptive analysis in the region, as well as to careful evaluations of the impact of various programs.
AF Embeddings and the Numerical Computation of Spectra in Irrational Rotation Algebras

A natural problem at the interface of operator theory and numerical analysis is that of finding a (finite dimensional) matrix whose eigenvalues approximate the spectrum of a given (infinite dimensional) operator. It is well-known that classical work of Pimsner and Voiculescu produces explicit matrix models for an interesting class of nontrivial examples (e.g., many discretized one-dimensional Schrodinger operators). In this paper, we observe that the spectra of their models (often) converge in the strongest possible sense—in the Hausdorff metric—and demonstrate that the rate of convergence is, in general, best possible.
Ligand Controlled Highly Regio- and Enantioselective Synthesis of α-Acyloxyketones by Palladium-Catalyzed Allylic Alkylation of 1,2-Enediol Carbonates

The palladium catalyzed decarboxylative asymmetric allylic alkylation of allyl 1,2-enediol carbonates 1 can decompose to either α-hydroxyketones 3 or α-hydroxyaldehydes 4. The product distribution is largely controlled by the ligand. Using Lnaph in DME we exclusively obtained the ketone product in good to excellent yields and high enantiomeric excesses. The reaction proceeds under extremely mild conditions, so we can have a broad range of choices of OR. Besides the commonly used protection groups such as OAc and OPiv, a more functionalized group such as methyl but-2-enoyl group can also be used, downstream process of which can afford other synthetically interesting structures.
Random matrix model approach to chiral symmetry

Abstract We review the application of random matrix theory (RMT) to chiral symmetry in QCD. Starting from the general philosophy of RMT we introduce a chiral random matrix model with the global symmetries of QCD. Exact results are obtained for universal properties of the Dirac spectrum: i) finite volume corrections to valence quark mass dependence of the chiral condensate, and ii) microscopic fluctuations of Dirac spectra. Comparisons with lattice QCD simulations are made. Most notably, the variance of the number of levels in an interval containing n levels on average is suppressed by a factor (log n)/π2n. An extension of the random matrix model to nonzero temperatures and chemical potential provides us with a schematic model of the chiral phase transition. In particular, this elucidates the nature of the quenched approximation at nonzero chemical potential.
A Load Balancing Tool for Distributed Parallel Loops

Large scale applications typically contain parallel loops with many iterates. The iterates of a parallel loop may have variable execution times which translate into performance degradation of an application due to load imbalance. This paper describes a tool for load balancing parallel loops on distributed-memory systems. The tool assumes that the data for a parallel loop to be executed is already partitioned among the participating processors. The tool utilizes the MPI library for interprocessor coordination, and determines processor workloads by loop scheduling techniques. The tool was designed independent of any application; hence, it must be supplied with a routine that encapsulates the computations for a chunk of loop iterates, as well as the routines to transfer data and results between processors. Performance evaluation on a Linux cluster indicates that the tool reduces the cost of executing a simulated irregular loop without load balancing by up to 81%. The tool is useful for parallelizing sequential applications with parallel loops, or as an alternate load balancing routine for existing parallel applications.
Prostate Cancer Susceptibility Locus on Chromosome 1q: A Confirmatory Study

Background: Recent recognition that a predisposition to prostate cancer can be inherited has led to a search for specific genes associated with the disease. Through a study of families with three or more affected first-degree relatives, a region on the long arm of chromosome 1 (i.e., 1q24-25) has been tentatively identified as containing a gene, HPC1, involved in the development of hereditary prostate cancer. Confirmation of this finding is needed, however, before attempts are made to isolate and characterize the putative HPC1 gene. Purpose: To confirm that chromosome 1q24-25 contains a gene relevant to hereditary prostate cancer, we analyzed an independent set of families, each with two or more affected individuals. Methods: Fifty-nine unrelated families were selected for analysis on the sole criterion that more than one living family member was affected by prostate cancer. DNA samples were subsequently isolated from 130 individuals with the disease. These samples were genotyped at six polymorphic marker sequences (D1S215, D1S2883, D1S466, D1S158, D1S518, and D1S2757) covering the chromosomal region proposed to contain HPC1. The resulting data were analyzed by nonparametric multipoint linkage (NPL) methods, yielding NPL Z scores and corresponding one-sided P values. Results: When the entire set of 59 families was considered, the occurrence of prostate cancer (and, presumably, the HPC1 gene) was most tightly linked to marker D1S466 (NPL Z score = 1.58; P = .0574). Analysis of the 20 families (51 affected individuals) fulfilling one or more of the proposed clinical criteria for hereditary prostate cancer (i.e., three or more affected individuals within one nuclear family; affected individuals in three successive generations [maternal or paternal lineage]; and/or clustering of two or more individuals affected before the age of 55 years) revealed more convincing evidence of disease linkage to chromosome 1q24-25 (maximum NPL Z score [at marker D1S466] = 1.72; P = .0451). The 39 families (79 affected individuals) that did not meet the clinical criteria for hereditary prostate cancer exhibited no significant evidence of disease linkage to DNA sequences at chromosome 1q24-25 (maximum NPL Z score [at marker D1S466] = 0.809; P = .208). The six African-American families in our study contributed disproportionately to the observation of linkage, with a maximum NPL Z score at marker D1S158 of 1.39 (P = .0848) for these families. Conclusions and Implications: Our data confirm that chromosome 1q24-25 is likely to contain a prostate cancer susceptibility gene. Future efforts at positional cloning of the HPC1 gene should focus on families who meet the proposed clinical criteria for hereditary prostate cancer. [J Natl Cancer Inst 1997;89:955-9]