cssi/SciSciGPT-SciSciNet huggingface dataset:
A Near-Optimal Sensor Scheduling Strategy for an on–off Controller With an Expensive Sensor

This paper describes an efficient method for scheduling an energy-consuming sensor sparingly in combination with an on-off controller, specifically for a finite horizon control problem in which only end states are critical. In certain low-power applications, such as autonomous microrobotics, on-off controllers can be very efficient in operating piezoelectric actuators (and other capacitive actuation schemes) compared to traditional analog and pulsewidth modulation controllers. However, with existing sensing circuitry, sensing at the same frequency as control can be prohibitively expensive, because energy consumption in the sensing circuitry may be comparable or even much higher than energy consumption for actuation. Instead, a method is presented for best scheduling a limited number of sensor measurements and updates to control inputs during a finite horizon on-off control problem, in response to Gaussian disturbances and measurement noise. To simplify the problem, a lower bound for the expected value of a quadratic error function of the end states is found, which permits rapid evaluation of candidate sensor times. When actuator energy consumption is incorporated in the optimization, this produces a numerically efficient near-optimal strategy for determining best measurement times and updates to the control input sequence.
Large-area, Lithography-free super absorbers and color filters at visible frequencies using ultrathin metallic films

Nanostructured photonic materials enable control and manipulation of light at subwavelength scales and exhibit unique optical functionalities. In particular, plasmonic materials and metamaterials have been widely utilized to achieve spectral transmission, reflection, and absorption filters based on localized or delocalized resonances arising from the interaction of photons with nanostructured materials. Realization of visible-frequency, high-performance, large-area, optical filters based on nanoplasmonic materials is rather challenging due to nanofabrication related problems (cost, fabrication imperfection, surface roughness) and optical losses of metals. Here, we propose and demonstrate large-area perfect absorbers and transmission filters that overcome difficulties associated with the nanofabrication using a lithography-free approach. We also utilize and benefit from the optical losses in metals in our optical filter designs. Our resonant optical filter design is based on a modified, asymmetric metal–in...
Institutions and Development

In late-century Africa, domestic reformers and the international community prescribed political reform as a means for securing policy reform. They sought to put an end to single party and military government and introduced multiparty politics. Using a principal agent framework, the author assesses the logical validity of these efforts. And employing a game theoretic approach, he traces the impact of political reform on political stability. He employs a panel of data from both African and global samples to measure the impact of reform on the economics and politics of Africa. The evidence suggests that reform has measurably curtailed the opportunistic use of politcal power, failed to influence the formulation of macro-economic policy, and increased the likelihood of political disorder. Copyright 2006, Oxford University Press.
Comparing Aspiration Models: The Role of Selective Attention

For many years, scholars have used a variety of models to measure organizational aspirations, but these alternative measures reflect differing assumptions about the decision-making processes determining aspiration levels. This study begins by examining some of the implications of the aspiration models in use. It then extends the theoretical model of aspiration levels from the behavioural theory of the firm to incorporate varying attention, another fundamental concept from the theory. Finally, it uses direct aspiration measures on the sales performance of retailers in a large automotive manufacturer to assess the alternative theories by comparing existing models with one that incorporates varying attention. We find support for a model where the importance of the factors influencing aspiration levels varies with the level of past firm performance relative to industry performance. Thus, the varying attention so central to the behavioural theory of the firm influences the formulation of aspirations.
Copper Corrosion With and Without Inhibitors

The utility of copper interconnects may ultimately depend on the ability to protect copper from corrosion. We have studied the capacity of lH-benzotriazole (1H-BTA) to provide a protective and stable surface film able to withstand harsh chemical and thermal environments. The film was characterized with electrochemical techniques, in situ ellipsometry, ex situ time-of-flight static secondary ion mass spectrometry, high-temperature mass spectrometry, and accelerated temperature and humidity tests. Several important passivating film properties (thickness, degree of polymerization, thermal stability, corrosion resistance) depend critically on the details of the film preparation conditions. The best corrosion protection is offered by the thin film formed on an oxidized Cu surface. This film has also shown the slowest growth kinetics and the highest degree of polymerization in the Cu-BTA structure. With more aggressive performance requirements for multilevel interconnections, higher conductivity metals, such as copper, are finding their way into a number of products. Copper is a relatively noble metal. Nevertheless, it reacts easily in ordinary, oxygen containing, environments (1). In view of the limited passivation offered by Cu-oxides, we have studied the effectiveness of organic azoles, such as lH-benzotriazole (1H-BTA), as a general method of controlling Cu degradation. For over 40 years 1H-BTA has been successfully used in the prevention of atmospheric Cu corrosion (2), in packaging, storage and transport, in the reduction of thermal oxidation and, in particular, in the protection of copper under immersed conditions (Ref. (3) and references within). The relevant literature is abundant but not unified in its teaching about bonding, thickness, composition and structure of the resulting film and the nature of its protection. Recent work from our laboratory, based on a combination of electrochemical, ellipsometric, and XPS data, has shown that the spontaneous reaction of Cu and 1H-BTA under a variety of conditions leads to the formation of Cu-BTA (4, 5), with copper being Cu +1 , as reported elsewhere (6-12). The formation of a Cu-N bond was clearly identified from the Cu LMM Auger lines. The film was formed both on an oxidized and an oxide-free Cu surface, in contrast to reports suggesting that the presence of Cu2O is a prerequisite for the buildup of CuBTA (8, 14). The thickness of the film was determined to be 0.5-4 nm in the pH range from 3 to 12, reaching 25 nm only under harsh conditions, i.e., in pH 2. Several recent studies of ultrahigh vacuum deposited 1H-BTA have indeed detected 1H-BTA adsorption on clean Cu metal (14-16). An electrochemical equivalent of such a film was formed in our laboratory at Cu 0 kept in
Synthesis of 2,3-diaminodihydropyrroles via thioimidate cyclopropane rearrangement

The synthesis of novel 2,3-diaminodihydropyrroles is reported. The key step is a thiomethylimidate cyclopropane rearrangement to afford a pyrrolothiomethylimidate intermediate. Reaction of this intermediate with amines produced the title compounds in good yields. The scope and mechanism of the reaction is discussed.
Decoupling the multiagent disjunctive temporal problem

In multiagent scheduling, each agent has to schedule its activities to respect its local (internal) temporal constraints, and also to satisfy external constraints between its activities and activities of other agents. A scheduling problem is decoupled if each agent can independently (and thus privately, autonomously, etc.) form a solution to its local problem such that agents' combined solutions are guaranteed to satisfy all external constraints. We expand previous work that decouples multiagent scheduling problems containing strictly conjunctive temporal constraints to more general problems containing disjunctive constraints. While this raises a host of challenging issues, agents can leverage shared information as early and as often as possible to quickly adopt additional temporal constraints within their local problems that sacrifice some local scheduling flexibility in favor of decoupled, independent, and rapid local scheduling.
Photo Quiz: An Unexpected Colonoscopic Finding in a 13-Year-Old Boy

A 13-year-old male presented to the Riley Hospital for Children at Indiana University Health emergency department with a 2-day history of constipation and a 1-day history of rectal bleeding. He had also passed several stools containing blood following administration of a laxative. At the time of evaluation, the patient was afebrile and denied anti-inflammatory drug ingestion, illicit substance abuse, epistaxis, hematemesis, travel outside Indiana, and consumption of raw or undercooked meat. Digital rectal examination revealed an ulcer in the posterior wall and a hemorrhoid in the anterior wall, while the remainder of the physical examination was unremarkable. A complete blood count and coagulation studies indicated mild anemia and an elevated neutrophil count, but other parameter values were within normal limits. A radiograph of the child's abdomen was also performed, which showed only a moderate amount of gas and stool retention. The patient's medical history was significant for developmental delay and Nissen fundoplication for esophageal reflux. Based on these findings, the patient was admitted for further evaluation by the gastrointestinal service. A colonoscopy performed the following morning confirmed the presence of a raised, erythematous, and friable rectal ulcer, while the rest of the colon and terminal ileum appeared normal. Biopsy specimens of the colon, terminal ileum, and rectal ulcer obtained during the colonoscopy did not reveal an obvious cause of the rectal ulcer, and the intestinal mucosa was unremarkable. However, one hematoxylin-and-eosin-stained section of the colon biopsy specimen revealed an ovoid object containing abundant eosinophilic granules measuring 1.0 by 0.75 mm in the greatest dimension (Fig. 1) in the lumen. The pathologist queried as to the presence of an intestinal parasite. FIG 1 Hematoxylin-and-eosin-stained colon biopsy specimen of the ovoid object (left; ×100 total magnification). The higher magnification demonstrates the cellular structure and outer wall (right; ×600 total magnification). (For answer and discussion, see page 3138 in this issue [doi:10.1128/JCM.00700-13].)
Dubious Premises—Evil Conclusions: Moral Reasoning at the Nuremberg Trials

Fifty years ago, 23 Nazi physicians were defendants before a military tribunal in Nuremberg, charged with crimes against humanity. During that trial, the world learned of their personal roles in human experimentation with political and military prisoners, mass eugenic sterilizations, state-ordered euthanasia of the “unfit,” and the program of genocide we now know as the Holocaust. These physicians, and their colleagues who did not stand trial, were universally condemned in the free world as ethical pariahs. The term “Nazi doctor” became the paradigm for total defection from the most rudimentary elements of medical morality. The caduceus literally became the instrument of the swastika.
Fusion Reactor Plasmas with Polarized Nuclei

Nuclear fusion rates can be enhanced or suppressed by polarization of the reacting nuclei. In a magnetic fusion reactor, the depolarization time is estimated to be longer than the reaction time.
Rapid and Enantioselective Synthetic Approaches to Germanicol and Other Pentacyclic Triterpenes

Two exceedingly short synthetic routes to the key intermediate 2 for the synthesis of the pentacyclic triterpene germanicol 1 have been developed. In the first, the (S)-epoxide of farnesyl bromide ...
The KM phase in semi-realistic heterotic orbifold models

In string-inspired semi-realistic heterotic orbifolds models with an anomalous U(1){sub X},a nonzero Kobayashi-Masakawa (KM) phase is shown to arise generically from the expectation values of complex scalar fields, which appear in nonrenormalizable quark mass couplings. Modular covariant nonrenormalizable superpotential couplings are constructed. A toy Z{sub 3} orbifold model is analyzed in some detail. Modular symmetries and orbifold selection rules are taken into account and do not lead to a cancellation of the KM phase. We also discuss attempts to obtain the KM phase solely from renormalizable interactions.
Optimization of input protection diode for high-speed applications

Optimization of input protection diodes for high-speed applications including radio frequency and Internet receivers is examined. The key parameters used to rate the diodes are the RC time constant and the failure point defined by human body model failure voltage per unit of capacitance. Minimizing the RC time constant for stripe diodes includes looking at tapered metal, wide ground stripes, slot contacts, background doping, and the length of the stripes. Maximizing the failure point includes looking at tapered metal, contacts, and proximity effects.
Credit Restrictions and the Market for Commercial Real Estate Loans

This paper develops a model of the market for commercial real estate loans based on the variables used by investors and lenders in property decision-making: the income capitalization (cap) rate, the debt-coverage ratio and the loan-to-value ratio. Empirical results for aggregate United States real estate originations and commitments for 1970–93 indicate that loan demand is sensitive to the cap rate and to building permit issuance. The dominant criterion used by lenders is the debt-coverage ratio as opposed to the loan-to-value ratio, a finding which may have implications for underwriting standards and credit policy.
Harmonic generation in adaptive feedforward cancellation schemes

The paper investigates the generation of harmonics in adaptive feedforward cancellation schemes. Specifically, it is shown that an algorithm designed to reject a certain number of frequency components may in fact be capable of reducing higher-order harmonics as well. This effect originates in the time-variation of the adaptive parameters. A consequence is that the adaptive system may perform better than the algorithm with the fixed, ideal parameters. Surprisingly, the response to higher-order harmonics can be calculated precisely, using a Laplace transform analysis. The origin of the numerical procedure is in the equivalence between the adaptive feedforward cancellation scheme and a control scheme based on the internal model principle. The implication of the results on design and implementation issues is discussed. >
Elimination of transverse instability in stripe solitons by one-dimensional lattices

We demonstrate theoretically and experimentally that the transverse instability of coherent soliton stripes can be greatly suppressed or totally eliminated when the soliton stripes propagate in a one-dimensional photonic lattice under self-defocusing nonlinearity.
Normal versus Noncentral Chi-Square Asymptotics of Misspecified Models.

The noncentral chi-square approximation of the distribution of the likelihood ratio (LR) test statistic is a critical part of the methodology in structural equation modeling. Recently, it was argued by some authors that in certain situations normal distributions may give a better approximation of the distribution of the LR test statistic. The main goal of this article is to evaluate the validity of employing these distributions in practice. Monte Carlo simulation results indicate that the noncentral chi-square distribution describes behavior of the LR test statistic well under small, moderate, and even severe misspecifications regardless of the sample size (as long as it is sufficiently large), whereas the normal distribution, with a bias correction, gives a slightly better approximation for extremely severe misspecifications. However, neither the noncentral chi-square distribution nor the theoretical normal distributions give a reasonable approximation of the LR test statistics under extremely severe misspecifications. Of course, extremely misspecified models are not of much practical interest. We also use the Thurstone data (Thurstone & Thurstone, 1941) from a classic study of mental ability for our illustration.
Synthesis and biological evaluation of novel macrocyclic paclitaxel analogues.

This work describes the synthesis of two novel macrocyclic taxoid constructs by ring-closing olefin metathesis (RCM) and their biological evaluation. Computational studies examine conformational profiles of 1 and 2 for their fit to the β-tubulin binding site determined by electron crystallography. The results support the hypothesis that paclitaxel binds to microtubules in a “T” conformation.
Optical design of giant telescopes for space

Increased performance for optical telescopes has historically come from larger apertures, from technological advances for the telescope components, such as detectors, and from access to better sites, such as space. Little has changed in the basic telescope design for a century. These conventional designs have served us well and will continue to do so with the Next Generation Space Telescope. There is an upper limit to the size of thsi type of telescope, set by the capacity to launch the required mass. For future space telescopes of 50, 100, 500 meter apertures, we have developed a new type of optical design. We use a primary reflector made from segments of flat and near-flat membranes. The secondary reflector and subsequent optics are supported in separate spacecraft, flying in formation with the primary reflector. In addition, each spacecraft maintains sunshields to keep the optics shaded from the sun. This paper explores the optical design issues for this type of giant space telescope.© (2000) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
The effect of propranolol on gene expression during the blood alcohol cycle of rats fed ethanol intragastrically.

Propranolol, a beta adrenergic blocker prevents the blood alcohol (BAL) cycle in rats fed ethanol intragastrically at a constant rate by preventing the cyclic changes in the metabolic rate caused by fluctuating levels of norepinephrine released into the blood. The change in the rate of metabolism changes the rate of alcohol elimination in the blood which causes the BAL to cycle. Microarray analysis of the livers from the rats fed ethanol and propranolol showed similar changes in clusters of functionally related gene expressions. The controls and the trough of the cycle differed dramatically from the cluster pattern seen in the rats at the peaks of the blood alcohol cycle. The changes in gene expression induced by ethanol were similar when propranolol was fed without ethanol especially with the changes in the kinases and phosphatases, Toll-like receptor signaling and cytokine-cytokine receptor interaction were also changed. The changes in gene expression caused by ethanol and propranolol feeding are alike probably because both drugs induce β adrenergic receptor desensitization.
A barcode shape descriptor for curve point cloud data

In this paper, we present a complete computational pipeline for extracting a compact shape descriptor for curve point cloud data (PCD). Our shape descriptor, called a barcode, is based on a blend of techniques from differential geometry and algebraic topology. We also provide a metric over the space of barcodes, enabling fast comparison of PCDs for shape recognition and clustering. To demonstrate the feasibility of our approach, we implement our pipeline and provide experimental evidence in shape classification and parametrization.
CLASS NUMBERS VIA 3-ISOGENIES AND ELLIPTIC SURFACES

We show that a character sum attached to a family of 3-isogenies defined on the fibers of a certain elliptic surface over &#x1d53d;p relates to the class number of the quadratic imaginary number field $\mathbb {Q}(\sqrt{-p})$. In this sense, this provides a higher-dimensional analog of some recent class number formulas associated to 2-isogenies of elliptic curves.
Possible effects of a cosmological constant on black hole evolution

We explore possible effects of vacuum energy on the evolution of black holes. If the universe contains a cosmological constant, and if black holes can absorb energy from the vacuum, then black hole evaporation could be greatly suppressed. For the magnitude of the cosmological constant suggested by current observations, black holes larger than ∼ 4 × 10 24 g would accrete energy rather than evaporate. In this scenario, all stellar and supermassive black holes would grow with time until they reach a maximum mass scale of ∼ 6 × 10 55 g, comparable to the mass contained within the present day cosmological horizon.
All frame-spun knots are slice

Frame-spun knots are constructed by spinning a knot of lower dimension about a framed submanifold of S n . We show that all frame-spun knots are slice (null-cobordant).
Hypervelocity Dust Storm Launched With a Coaxial Plasma Gun

A dust storm consisting of carbon grains accelerated to speeds of up to ~ 3 km/s has been launched by a plasma jet produced in a coaxial gun. Diamond and graphite powders with grain radii of 0.5-30 mum have been used. A distinctive feature of this plasma accelerator is that it can use different types of gases and can operate with microparticles having a large range of sizes. Deuterium gas and carbon dust are chosen to be compatible with fusion plasmas as a diagnostic tool. The operating voltages of the coaxial gun are between 5 and 10 kV, and the maximum measured discharge current is 250 kA. High-speed imaging of the plasma jet accelerated by the J x B force, and exiting the gun at 34 km/s, shows a good collimation of the flow for about 1.5 m before it diverges inside a large vacuum tank.
Status of Fiber Optic Research in the USA

This paper reviews the technical aspects and status of optical fiber waveguide, cabling, light sources, and signal detection. Advances in fiber waveguide have made possible the transmission of high data rate information over very small diameter waveguide. Four fiber types are currently receiving most attention as a result of their attenuation, dispersion, and cost characteristics. Light sources for fiber optical applications are very promising due to recent developments in semiconductor injection lasers. Receiver technology is well developed and avalanche photodiodes provide high sensitivity receiver performance for most data bandwidths of interest.
Spontaneous supersymmetry breaking in two dimensional lattice super QCD

We report on a non-perturbative study of two dimensional $$ \mathcal{N}=\left(2,2\right) $$ super QCD. Our lattice formulation retains a single exact supersymmetry at non-zero lattice spacing, and contains N f fermions in the fundamental representation of a U(N c ) gauge group. The lattice action we employ contains an additional Fayet-Iliopoulos term which is also invariant under the exact lattice supersymmetry. This work constitutes the first numerical study of this theory which serves as a toy model for understanding some of the issues that are expected to arise in four dimensional super QCD. We present evidence that the exact supersymmetry breaks spontaneously when N f < N c in agreement with theoretical expectations.
Borderline personality disorder: ontogeny of a diagnosis

Objective: The purpose of this article is to describe the development of the borderline personality disorder diagnosis, highlighting both the obstacles encountered and the associated achievements. Method: On the basis of a review of the literature, the author provides a chronological account of the borderline construct in psychiatry, summarizing progress in decade-long intervals. Results: Borderline personality disorder has moved from being a psychoanalytic colloquialism for untreatable neurotics to becoming a valid diagnosis with significant heritability and with specific and effective psychotherapeutic treatments. Nonetheless, patients with this disorder pose a major public health problem while they themselves remain highly stigmatized and largely neglected. Conclusions: Despite remarkable changes in our knowledge about borderline personality disorder, increased awareness involving much more education and research is still needed. Psychiatric institutions, professional organizations, public policies, an...
Invariant based quartet puzzling.

Background: First proposed by Cavender and Felsenstein, and Lake, invariant based algorithms for phylogenetic reconstruction were widely dismissed by practicing biologists because invariants were perceived to have limited accuracy in constructing trees based on DNA sequences of reasonable length. Recent developments by algebraic geometers have led to the construction of lists of invariants which have been demonstrated to be more accurate on small sequences, but were limited in that they could only be used for trees with small numbers of taxa. We have developed and tested an invariant based quartet puzzling algorithm which is accurate and efficient for biologically reasonable data sets. Results: We found that our algorithm outperforms Maximum Likelihood based quartet puzzling on data sets simulated with low to medium evolutionary rates. For faster rates of evolution, invariant based quartet puzzling is reasonable but less effective than maximum likelihood based puzzling. Conclusions: This is a proof of concept algorithm which is not intended to replace existing reconstruction algorithms. Rather, the conclusion is that when seeking solutions to a new wave of phylogenetic problems (super tree algorithms, gene vs. species tree, mixture models), invariant based methods should be considered. This article demonstrates that invariants are a practical, reasonable and flexible source for reconstruction techniques.
Biaxial strain and variable stiffness in aponeuroses

The elastic structures of many muscles include both an extramuscular free tendon as well as a sheet-like aponeurosis. An important distinguishing feature of aponeuroses is that these tendinous structures function as the attachment and insertion surfaces of muscle fascicles and therefore surround a substantial portion of the muscle belly. As a result, aponeuroses must expand both parallel (longitudinal) and perpendicular (transverse) to a muscle's line of action when contracting muscles bulge to maintain a constant volume. In this study, we use biplanar high-speed fluoroscopy to track the strain patterns of the turkey lateral gastrocnemius aponeurosis during active and passive force production in situ. We find that the behaviour of the aponeurosis during passive force production is consistent with uniaxial loading, as aponeuroses stretch only in the longitudinal direction. By contrast, our results show that aponeuroses are stretched in both longitudinal and transverse directions during active force production and that transverse strains are on average 4 times greater than longitudinal strains. Biaxial loading of aponeuroses appears to effectively modulate longitudinal stiffness, as we find the measured stiffness in the longitudinal direction varies in proportion to transverse strain. We conclude that biaxial strain during active force production distinguishes aponeuroses from free tendons and may function to dynamically modulate stiffness along the axis of muscle force production. It is likely that consideration of strains measured only in the longitudinal direction result in an underestimation of aponeurosis stiffness as well as its capacity for elastic energy storage.
Photonic band gap higher order mode coupler for the international linear collider

A photonic band gap (PBG) higher-order-mode (HOM) coupler is proposed as an alternative configuration design (ACD) for the HOM coupler for the international linear collider (ILC). The PBG HOM coupler uses a two-dimensional triangular PBG structure with good axial symmetry. Simulation studies of a PBG HOM coupler show that it maintains the operating mode at 1.3 GHz with Q > 1010. While a PBG HOM coupler provides superior damping for all the higher order modes, in principle, the effectiveness of HOM damping remains an open subject of future investigations.
Detection of weakly conserved ancestral mammalian regulatory sequences by primate comparisons

Background Genomic comparisons between human and distant, non-primate mammals are commonly used to identify cis-regulatory elements based on constrained sequence evolution. However, these methods fail to detect functional elements that are too weakly conserved among mammals to distinguish them from non-functional DNA.
An Emerging Role of mTOR in Lipid Biosynthesis

Lipid biosynthesis is essential for the maintenance of cellular homeostasis. The lipids produced by cells (glycerolipids, fatty acids, phospholipids, cholesterol, and sphingolipids) are used as an energy source/reserve, as building blocks for membrane biosynthesis, as precursor molecules for the synthesis of various cellular products, and as signaling molecules. Defects in lipid synthesis or processing contribute to the development of many diseases, including obesity, insulin resistance, type 2 diabetes, non-alcoholic fatty liver disease, and cancer. Studies published over the last few years have shown that the target of rapamycin (TOR), a conserved serine/threonine kinase with an important role in regulating cell growth, controls lipid biosynthesis through various mechanisms. Here, we review these findings and briefly discuss their potential relevance for human health and disease.
Neural Computations Underlying Arbitration between Model-Based and Model-free Learning

There is accumulating neural evidence to support the existence of two distinct systems for guiding action selection, a deliberative "model-based" and a reflexive "model-free" system. However, little is known about how the brain determines which of these systems controls behavior at one moment in time. We provide evidence for an arbitration mechanism that allocates the degree of control over behavior by model-based and model-free systems as a function of the reliability of their respective predictions. We show that the inferior lateral prefrontal and frontopolar cortex encode both reliability signals and the output of a comparison between those signals, implicating these regions in the arbitration process. Moreover, connectivity between these regions and model-free valuation areas is negatively modulated by the degree of model-based control in the arbitrator, suggesting that arbitration may work through modulation of the model-free valuation system when the arbitrator deems that the model-based system should drive behavior.
Multilingual part-of-speech tagging: two unsupervised approaches

We demonstrate the effectiveness of multilingual learning for unsupervised part-of-speech tagging. The central assumption of our work is that by combining cues from multiple languages, the structure of each becomes more apparent. We consider two ways of applying this intuition to the problem of unsupervised part-of-speech tagging: a model that directly merges tag structures for a pair of languages into a single sequence and a second model which instead incorporates multilingual context using latent variables. Both approaches are formulated as hierarchical Bayesian models, using Markov Chain Monte Carlo sampling techniques for inference. Our results demonstrate that by incorporating multilingual evidence we can achieve impressive performance gains across a range of scenarios. We also found that performance improves steadily as the number of available languages increases.
An efficient maximum entropy technique for 2-D isotropic random fields

A linear MEM (maximum-entropy spectral estimation method) algorithm for 2-D isotropic random fields is introduced. Unlike general 2-D covariances, isotropic covariance functions that are positive definite on a disk are known to be extendible. A computationally efficient procedure is developed for computing the MEM isotropic covariance function that is given over a finite disk of radius 2R. It is shown that the isotropic MEM problem has a linear solution and that it is equivalent to the problem of constructing the optimal linear filter for estimating the underlying isotropic field at a point on the boundary of a disk radius R, given noisy measurements of the field inside the disk. The procedure is guaranteed to yield a valid isotropic spectral estimate and is computationally efficient since it requires only O(BRL/sup 2/) operations, where L is the number of points used to discretize the interval (0, R) and B is the bandwidth in the wave-number plane of the spectrum that to be estimated. Examples are presented to illustrate the behaviour of the algorithm and its high-resolution property. >
Finitely Additive Probabilities and the Fundamental Theorem of Asset Pricing

This work aims at a deeper understanding of the mathematical implications of the economically-sound condition of absence of arbitrages of the first kind in a financial market. In the spirit of the Fundamental Theorem of Asset Pricing (FTAP), it is shown here that the absence of arbitrages of the first kind in the market is equivalent to the existence of a finitely additive probability, weakly equivalent to the original and only locally countably additive, under which the discounted wealth processes become “local martingales”. The aforementioned result is then used to obtain an independent proof of the classical FTAP, as it appears in Delbaen and Schachermayer (Math. Ann. 300:463–520, 1994). Finally, an elementary and short treatment of the previous discussion is presented for the case of continuous-path semimartingale asset-price processes.
Sub-shot-noise heterodyne polarimetry

We report an experimental demonstration of a heterodyne polarization rotation measurement with a noise floor 4.8 dB below the optical shot noise by use of classically phase-locked quantum twin beams emitted above threshold by an ultrastable type II Na:KTP cw optical parametric oscillator. We believe that this is the largest noise reduction achieved to date in optical phase-difference measurements.
Positive periodic solutions of singular systems of first order ordinary differential equations

The existence and multiplicity of positive periodic solutions for first non-autonomous singular systems are established with superlinearity or sublinearity assumptions at infinity for an appropriately chosen parameter. The proof of our results is based on the Krasnoselskii fixed point theorem in a cone.
Steenbrink vanishing extended

The notion of DB index, a measure of how far a singularity of a pair is frombeingDu Bois, is introduced and used to generalize vanishing theorems of [Ste85], [GKKP11], and [Kov11] with simpler and more natural proofs than the originals. An argument used in one of these proofs also yields an additional theorem connecting various push forwards that lie outside of the range of the validity of the above vanishing theorems.
Catalytic Intramolecular Ketone Alkylation with Olefins by Dual Activation

Two complementary methods for catalytic intramolecular ketone alkylation reactions with unactivated olefins, resulting in Conia-ene-type reactions, are reported. The transformations are enabled by dual activation of both the ketone and the olefin and are atom-economical as stoichiometric oxidants or reductants are not required. Assisted by Kool's aniline catalyst, the reaction conditions can be both pH- and redox-neutral. A broad range of functional groups are thus tolerated. Whereas the rhodium catalysts are effective for the formation of five-membered rings, a ruthenium-based system that affords the six-membered ring products was also developed.
Tandem radical nitrile transfer-cyclization reactions of 1,3-dioxane-4-nitriles: Synthesis of spirocyclic systems

Abstract Reduction of remote halogen substituents with n-Bu3SnH leads to efficient 1,4- and 1,5-nitrile transfer from 1,3-dioxane-4-nitriles and subsequent stereoselective reduction. These radical-transfer reactions provide a mild alternative to the Li/NH3 reductive decyanation previously used to generate syn-1,3-diols from 1,3-dioxane-4-nitriles. Compounds containing appropriate unsaturation undergo subsequent radical cyclization reactions to give spirocyclic products.
The President and the Distribution of Federal Spending

Scholarship on distributive politics focuses almost exclusively on the internal operations of Congress, paying particular attention to committees and majority parties. This article highlights the president, who has extensive opportunities, both ex ante and ex post, to influence the distribution of federal outlays. We analyze two databases that track the geographic spending of nearly every domestic program over a 24-year period—the largest and most comprehensive panels of federal spending patterns ever assembled. Using district and county fixed-effects estimation strategies, we find no evidence of committee influence and mixed evidence that majority party members receive larger shares of federal outlays. We find that districts and counties receive systematically more federal outlays when legislators in the president's party represent them.
Plasma Lens Backgrounds at a Future Linear Collider

A 'plasma lens' might be used to enhance the luminosity of future linear colliders. However, its utility for this purpose depends largely on the potential backgrounds that may be induced by the insertion of such a device in the interaction region of the detector. In this note we identify different sources of such backgrounds, calculate their event rates from the elementary interaction processes, and evaluate their effects on the major parts of a hypothetical Next Linear Collider (NLC) detector. For plasma lens parameters which give a factor of seven enhancement of the luminosity, and using the NLC design for beam parameters as a reference, we find that the background yields are fairly high, and require further study and improvements in detector technology to avoid their impact.
THE STRUCTURE FUNCTION OF VARIABLE 1.4 GHz RADIO SOURCES BASED ON NVSS AND FIRST OBSERVATIONS

We augment the two widest/deepest 1.4 GHz radio surveys, the NRAO VLA Sky Survey (NVSS) and the Faint Images of the Radio Sky at Twenty centimeters (FIRST), with the mean epoch in which each source was observed. We use these catalogs to search for unresolved sources that vary between the FIRST and NVSS epochs. We find 43 variable sources (0.1% of the sources) that vary by more than 4σ, and we construct the mean structure function of these objects. This enables us to explore radio variability on timescales between several months and about five years. We find that, on these timescales, the mean structure function of the variable sources is consistent with a flat structure function. A plausible explanation to these observations is that a large fraction of the variability at 1.4 GHz is induced by scintillations in the interstellar medium, rather than by intrinsic variability. Finally, for a subsample of the variables for which the redshift is available, we do not find strong evidence for a correlation between the variability amplitude and the source redshift.
Carotid stenting and angioplasty: A statement for healthcare professionals from the councils on cardiovascular radiology, stroke, cardio- thoracic and vascular surgery, epidemiology and prevention, and clinical cardiology, American Heart Association

Carotid artery stenosis, particularly involving the origin of the internal carotid artery, is a frequent clinical problem. These stenoses, almost invariably atherosclerotic, can present as asymptomatic bruits discovered on physical examination, one or more transient ischemic attacks related to embolization of thrombus from stenotic lesions or to hypoperfusion, or less commonly, as an ischemic stroke. From the results of three high-quality prospective randomized trials,1 2 3 it has become apparent that symptomatic stenoses that narrow the diameter of the carotid artery more than 60% to 70% lead to a significant incidence of stroke if treated medically. The risk of stroke associated with such a lesion in symptomatic patients treated with antiplatelet therapy alone is thought to be 26%.3 With carotid endarterectomy and aspirin, this risk is lowered to 9%, a statistically significant difference.3 In patients with or without symptoms who have a stenosis ≤60%, the effectiveness of either medical therapy or carotid endarterectomy in preventing significant neurological events is not known. In symptomatic patients with <30% stenosis, medical therapy is superior to surgical therapy.2 Studies attempting to define the benefit of therapy in symptomatic patients with <60% stenosis are currently under way. Accrual of patients has slowed, however, because data show clear efficacy in symptomatic patients with stenoses ≥70%, leading to a bias toward surgery in symptomatic patients with less severe stenoses. In general the role of surgery for asymptomatic stenosis remains controversial, with some recent opinions suggesting that it may not be indicated.4 In one high-quality trial with selected experienced surgeons, there was a modest reduction in absolute risk in asymptomatic patients with stenosis ≥60%, but the significance of this finding has been debated.5 6 Although mortality associated with conventional antiplatelet therapy has been minimal,7 surgery clearly has significant perioperative morbidity and …
Functional outcome of patients with salvageable limbs with grades III-B and III-C open fractures of the tibia

Numerous reports list predictive criteria to determine whether Gustilio-type tibial III-B and III-C fractures of the tibia are salvageable. What is lacking are long-term reports of comprehensive functional outcome of these severe injuries. We evaluated the functional outcome of patients with our own seven-scale score. Fifty-four patients with 57 types III-B (n = 41) and III-C (n = 16) open tibial fractures sustained between 1980 and 1989 were recalled for evaluation. There were 45 men and 9 women (average age, 28.4 years; range, 4–68 years). Follow-up periods averaged 48.2 months (range, 12–116 months). Salvage rate for the III-B fractures was 75% (n = 31) and for the III-C fractures 37% (n = 6). We conclude that the functional score is a simple and complete method for assessing the functional outcome of patients undergoing limb salvage procedures. © 1996 Wiley-Liss, Inc.
Do family caps reduce out-of-wedlock births? Evidence from Arkansas, Georgia, Indiana, New Jersey and Virginia

During the 1990s, 23 states implemented family cap policies as a means to reduce the incidence of out-of-wedlock births among welfare recipients. Using Current Population Survey data from 1989 to 1999, we examine the impact of family cap policies on the birth rates of single, less-educated women with children. We use the first five states that were granted waivers from the Department of Health and Human Services to implement family caps as “natural experiments.” Specifically, we compare trends in out-of-wedlock birth rates in Arkansas, Georgia, Indiana, New Jersey and Virginia to trends in states that did not implement family caps or any other waivers prior to the Personal Responsibility and Work Opportunity Reconciliation Act. We employ several techniques to increase the credibility of results from our “natural experiment,” such as the inclusion of multiple comparison groups, controls for differential time trends, and “difference-in-difference-in-differences” estimators. Our regression estimates generally do not provide evidence that family cap policies reduce the incidence of out-of-wedlock births among single, less-educated women with children.
Community Building at the Time of Nargis: The ASEAN Response

Cyclone Nargis was one of the most powerful disasters to hit Myanmar and Southeast Asia. Myanmar was criticized internationally for its allegedly slow effort in allowing international aid to enter into the country. This paper examines the criticism levelled against the ASEAN for its slow response in providing aid to the beleaguered in Myanmar and relates that criticism to ASEAN’s disaster management policy. It focuses on ASEAN’s engagement with Myanmar in order to allow humanitarian aid to flow into the country. The paper suggests that in time ASEAN will have to move from its doctrine of non-intervention in the affairs of a sovereign state to one of non-indifference if it wishes to remain relevant. Ultimately, ASEAN will have to re-evaluate its own goals in order to be a more successful apparatus for interstate and regional affairs, especially with respect to humanitarian crises brought about by natural disasters.
Octahedral Metal Clusters [Nb6Cl12(CN)6]4– as Molecular Building Blocks: From Supramolecular Assemblies to Coordination Polymers

There are considerable advantages for using metal clusters as building units of supramolecular materials because of their unique structural, chemical, and physical properties, all of which fall in between normal valence compounds and the metals. In this microreview, we describe the synthetic methodology and structural properties of recent findings in the use of octahedral niobium hexacyanochloride anions as building units of assemblies of different size, charge, and dimensionality. We focus on the use of a metal-directed approach to prepare cluster-based supramolecular assemblies and coordination polymers with one-, two-, and three-dimensional frameworks. The materials described herein are all built from diamagnetic cyanochloride cluster anions [Nb 6 Cl 12 (CN) 6 ] 4- and coordinatively unsaturated metal complexes such as [Mn(salen)] + and their derivatives. The overall structures are largely determined by the number of coordination sites available for linkage to the cluster unit and coordination preferences of the metal complexes.
STATUS OF CHARM FLAVOR PHYSICS

The role of charm in testing the Standard Model description of quark mixing and CP violation through measurements of lifetimes, decay constants and semileptonic form factors is reviewed. Together with Lattice QCD, charm has the potential this decade to maximize the sensitivity of the entire flavor physics program to new physics. and pave the way for understanding physics beyond the Standard Model at the LHC in the coming decade. The status of indirect searches for physics beyond the Standard Model through charm mixing, CP-violation and rare decays is also reported.
Concurrent Feedback/Feedforward Design for Second Order Systems

This paper studies the problem of concur- rent design of a feedback controller and a pre-filter to minimize a weighted cost comprising the maneuver time and the input power. The pre-filter is parameterized as a time-delay filter motivated by the Posicast controller. The proposed technique is illustrated on a double integrator assuming that the feedback controller is of the proportional derivative form. A closed form expression relating the weighting parameter and the number of delays, to the feedback gains is derived. The proposed technique is also illustrated on spring-mass and spring- mass-dashpot systems.
Synthesis and Bergman cyclization of a β-extended porphyrenediyne

Condensation of a porphyrin-2,3-dione with a 1,2-diaminoarenediyne affords a β-extended porphyrinic-enediyne: upon thermal Bergman cyclization the quinoxaline spacer positioned between the macrocycle and the enediyne prevents tandem radical cyclization to a picenoporphyrin.
Gold(I)‐Catalyzed Stereoconvergent, Intermolecular Enantioselective Hydroamination of Allenes

A 1:2 mixture of [(S)-2](AuCl)2 [(S)-2 = (S)-3,5-t-Bu-4-MeO-MeOBIPHEP] and AgBF4 catalyzes the stereoconvergent, intermolecular enantioselective hydroamination of chiral, racemic 1,3-disubstituted allenes with N-unsubstituted carbamates to form N-allylic carbamates in good yield, with high regio- and diastereoselectivity, and up to 92% ee.