cssi/SciSciGPT-SciSciNet huggingface dataset:
Cytochemical Localization of Calcium in Cap Cells of Primary Roots of Zea mays L.

The distribution of calcium (Ca) in caps of vertically- and horizontally-oriented roots of Zea mays was monitored to determine its possible role in root graviresponsiveness. A modification of the antimonate precipitation procedure was used to localize Ca in situ. In vertically-oriented roots, the presumed graviperceptive (i.e., columella) cells were characterized by minimal and symmetric staining of the plasmalemma and mitochondria. No precipitate was present in plasmodesmata or cell walls. Within 5 min after horizontal reorientation, staining was associated with the portion of the cell wall adjacent to the distal end of the cell. This asymmetric staining persisted throughout the onset of gravicurvature. No staining of lateral cell walls of columella cells was observed at any stage of gravicurvature, suggesting that a lateral flow of Ca through the columella tissue of horizontally-oriented roots does not occur. The outermost peripheral cells of roots oriented horizontally and vertically secrete Ca through plasmodesmata-like structures in their cell walls. These results are discussed relative to proposed roles of root-cap Ca in root gravicurvature.
Dimension Characterizations of Complexity Classes

We use derandomization to show that sequences of positive pspace-dimension – in fact, even positive Δ\(^{\rm p}_{\rm k}\)-dimension for suitable k – have, for many purposes, the full power of random oracles. For example, we show that, if S is any binary sequence whose Δ\(^{\rm p}_{\rm 3}\)-dimension is positive, then BPP ⊆ P S and, moreover, every BPP promise problem is P S -separable. We prove analogous results at higher levels of the polynomial-time hierarchy.
Anarchy, State, and Dystopia: Venezuelan Economic Institutions before the Advent of Oil

This article studies the evolution of Venezuelan economic institutions before the emergence of oil exploitation in 1920. We argue that, by 1920, Venezuela had developed a highly centralised state and a professionalised military. These two institutions ensured that growing oil revenues would strengthen the state structure and protected Venezuela from the resource-conflict trap into which many oil-abundant countries have fallen. We also argue that the failure to develop institutions that could mediate between sectoral demands and the state, the subordination of property rights to political imperatives and the political dominance of the commercial-financial elite conditioned the nation‘s response to the post-1920 influx of oil revenues.
Effect of Particle Size during Tungsten Chemical Mechanical Polishing

The size of the abrasive particles plays a critical role in controlling the polishing rate and the surface roughness during chemical mechanical polishing of interconnect materials during semiconductor processing. Earlier reports on the effect of particle size on polishing in silica show contradictory conclusions. To the best of our knowledge, a systematic study of the effect of particle size on tungsten polishing has not been published. This paper describes the controlled measurements that were conducted to determine the effect of alumina particle size during polishing of tungsten. Alumina particles of similar phase and shape with size varying from 0.1 to diam were used in these experiments. The polishing experiments showed that the local roughness of the polished surfaces was insensitive to alumina particle size. The removal rate was found to increase with decreasing particle size and increased solids loading. These results suggest that the removal rate mechanism is not a scratching type process, but may be related to the contact surface area between particles and polished surface controlling the reaction rate. ©1999 The Electrochemical Society
Mahotas: Open source software for scriptable computer vision

Mahotas is a computer vision library for Python. It contains traditional image processing functionality such as filtering and morphological operations as well as more modern computer vision functions for feature computation, including interest point detection and local descriptors. The interface is in Python, a dynamic programming language, which is appropriate for fast development, but the algorithms are implemented in C++ and are tuned for speed. The library is designed to fit in with the scientific software ecosystem in this language and can leverage the existing infrastructure developed in that language. Mahotas is released under a liberal open source license (MIT License) and is available from http://github.com/luispedro/mahotas and from the Python Package Index (http://pypi.python.org/pypi/mahotas). Tutorials and full API documentation are available online at http://mahotas.readthedocs.org/.
Concise and enantioselective total synthesis of (-)-mehranine, (-)-methylenebismehranine, and related Aspidosperma alkaloids.

We report an efficient and highly stereoselective synthetic strategy for the synthesis of aspidosperma alkaloids based on the transannular cyclization of a chiral lactam precursor. Three new stereocenters are formed in this key step with excellent level of diastereoselection due to the conformational bias of the cyclization precursor, leading to a versatile pentacyclic intermediate. A subsequent stereoselective epoxidation followed by a mild formamide reduction enabled the first total synthesis of the aspidosperma alkaloids (−)-mehranine and (+)-(6S,7S)-dihydroxy-N-methylaspidospermidine. A late-stage scandium trifluoromethanesulfonate-mediated dimerization of (−)-mehranine enabled the first total synthesis of (−)-methylenebismehranine.
A COLLISIONAL FAMILY IN THE CLASSICAL KUIPER BELT

The dynamical evolution of classical Kuiper belt objects (CKBOs) is divided into two parts, according to the secular theory of test particle orbits. The first part is a forced oscillation driven by the planets, while the second part is a free oscillation whose amplitude is determined by the initial orbit of the test particle. We extract the free orbital inclinations and free orbital eccentricities from the osculating elements of 125 known CKBOs. The free inclinations of 32 CKBOs strongly cluster about 2° at orbital semimajor axes between 44 and 45 AU. We propose that these objects comprise a collisional family, the first so identified in the Kuiper belt. Members of this family are plausibly the fragments of an ancient parent body having a minimum diameter of ~800 km. This body was disrupted upon colliding with a comparably sized object and generated ejecta having similar free inclinations. Our candidate family is dynamically akin to a subfamily of Koronis asteroids located at semimajor axes less than 2.91 AU; both families exhibit a wider range in free eccentricity than in free inclination, implying that the relative velocity between parent and projectile prior to impact lay mostly in the invariable plane of the solar system. We urge more discoveries of new CKBOs, to test the reality of our candidate family, and more physical studies of candidate family members, to probe the heretofore unseen interior of a massive, primitive planetesimal.
Trajectory and atmospheric structure from entry probes: Demonstration of a real-time reconstruction technique using a simple direct-to-Earth radio link

Abstract The reconstruction of the trajectory and atmospheric structure associated with an entry probe has traditionally relied upon onboard accelerometer measurements. Here we outline an equivalent reconstruction technique that uses Doppler-shifted direct-to-Earth transmissions instead. A critical assumption is that the entry probe's angle of attack is zero. The technique is successfully demonstrated on the atmospheric entry of the Mars Exploration Rover Opportunity, terminating at parachute deployment. This technique can be applied in real-time, which supports mission operations and public engagement. It can also be applied to entry probes that fail during their high-risk atmospheric entry.
[26]Hexaphyrin(1.1.1.1.0.0): an all-aza isomer of rubyrin with an inverted pyrrole subunit

The synthesis, characterization and X-ray structure of an hexapyrrolic macrocycle, [26]hexaphyrin(1.1.1.1.0.0), is reported; it is characterized by a partially inverted structure.
Acceleration-induced nonlocal electrodynamics in Minkowski spacetime

Abstract We discuss two nonlocal models of electrodynamics in which the nonlocality is induced by the acceleration of the observer. Such an observer actually measures an electromagnetic field that exhibits persistent memory effects. We compare Mashhoon's model with a new ansatz developed here in the framework of charge & flux electrodynamics with a constitutive law involving the Levi-Civita connection as seen from the observer's local frame and conclude that they are in partial agreement only for the case of constant acceleration.
FREE VASCULARISED FIBULAR GRAFTING FOR RECONSTRUCTION AFTER TUMOUR RESECTION

We have reviewed 30 patients at a mean of 36 months after free vascularised fibular transfer to reconstruct massive skeletal defects after resection of primary bone tumours. There were 23 malignant and 7 benign neoplasms, half in the lower limb and half in the upper. Arthrodesis was performed in 15 and intercalary bone replacement in 15. The mean fibular graft length was 189 mm. Union was achieved in 27 (90%) at an average of 7.6 months, and the 3-year survival was 89%. There was a high complication rate (50%), but most resolved without greatly influencing the final outcome. There was local recurrence in two (6.7%), but 16 of the 24 assessed patients (67%) had satisfactory functional results. This is a reasonably effective means of reconstruction for limb salvage after resection of tumours.
Eddy-Induced Instability for Low-Frequency Variability

Synoptic eddy‐mean flow interaction has been recognized as one of the key sources for extratropical lowfrequency variability. In this paper, the underlying dynamics of this interaction are examined from the perspective of a synoptic eddy-induced dynamic instability. To delineate this instability, a barotropic model is used that is linearized with respect to a stochastic basic flow prescribed with both climatologic-mean flow and synoptic eddy statistics. This linear model captures the dynamics of feedback between synoptic eddy and lowfrequency flow through a dynamic closure that relates the anomalous eddy vorticity forcing to low-frequency flowanomalies.Afterreducingthisdynamicclosuretoitsfundamentalcomponents, thisstabilityiselucidated withanalyticalresultsunderthemostidealizedconsiderationofbasicflow.It isshownthatthroughsystematic alteration of the synoptic eddy structures in the basic flow, a low-frequency planetary-scale perturbation generates anomalous eddy vorticity forcing positively proportional to the vorticity of the perturbation. Such a perturbation amplifies itself; the energy source for its growth comes from the reservoir residing in the basic synoptic eddy activity. Thus, the growth rate of the synoptic eddy-induced dynamic instability depends primarily on the kinetic energy level of the basic synoptic eddy activity. Moreover, this instability is scale selective with preference for zonal symmetric and asymmetric planetary-scale modes, whose meridional and zonal scales are roughly in the range of those of the observed leading low-frequency patterns. Analysis of this synoptic eddy-induced instability provides insight into the origin of extratropical low-frequency variability.
Finding endogenously formed communities

A central problem in data mining and social network analysis is determining overlapping communities (clusters) among individuals or objects in the absence of external identification or tagging. We address this problem by introducing a framework that captures the notion of communities or clusters determined by the relative affinities among their members. To this end we define what we call an affinity system, which is a set of elements, each with a vector characterizing its preference for all other elements in the set. We define a natural notion of (potentially overlapping) communities in an affinity system, in which the members of a given community collectively prefer each other to anyone else outside the community. Thus these communities are endogenously formed in the affinity system and are "self-determined" or "self-certified" by its members.We provide a tight polynomial bound on the number of self-determined communities as a function of the robustness of the community. We present a polynomial-time algorithm for enumerating these communities. Moreover, we obtain a local algorithm with a strong stochastic performance guarantee that can find a community in time nearly linear in the of size the community (as opposed to the size of the network).Social networks and social interactions fit particularly naturally within the affinity system framework -- if we can appropriately extract the affinities from the relatively sparse yet rich information from social networks and social interactions, our analysis then yields a set of efficient algorithms for enumerating self-determined communities in social networks. In the context of social networks we also connect our analysis with results about (α, β)-clusters introduced by Mishra, Schreiber, Stanton, and Tarjan [22, 23]. In contrast with the polynomial bound we prove on the number of communities in the affinity system model, we show that there exists a family of networks with superpolynomial number of (α, β)-clusters.
Nutrition and Cognitive Achievement: An Evaluation of the School Breakfast Program

This paper investigates the impact of the School Breakfast Program (SBP) on cognitive achievement. The SBP is a federal entitlement program that offers breakfast to any student, including free breakfast for any low-income student, who attends a school that participates in the program. To increase the availability of the SBP, many states mandate that schools participate in the program if the percent of free or reduced-price eligible students in a school exceeds a specific threshold. Using the details of these mandates as a source of identifying variation, I find that the availability of the program increases student achievement.
On pattern classification algorithms--Introduction and survey

This paper attempts to lay bare the underlying ideas used in various pattern classification algorithms reported in the literature. It is shown that these algorithms can be classified according to the type of input information required and that the techniques of estimation, decision, and optimization theory can be used effectively to derive known as well as new results.
Computation of the current density in nonlinear materials subjected to large current pulses

The finite element method and the finite difference method are used to calculate the current distribution in two nonlinear conductors. The first conductor is a small ferromagnetic wire subjected to a current pulse that rises to 10000 A in 10 mu s. Results from the transient thermal and transient magnetic solvers of the finite element code FLUX2D are used to compute the current density in the wire. The second conductor is a metal oxide varistor. Maxwell's equations, Ohm's law, and the varistor relation for the resistivity and the current density of rho = alpha j/sup - beta / are used to derive a nonlinear differential equation. The solutions of the differential equation are obtained by a finite difference approximation and a shooting method. The behavior predicted by these calculations is in agreement with experiments. >
Matrix metalloproteinases (MMPs): Chemical–biological functions and (Q)SARs

Matrix metalloproteinases (MMPs) are a large family of calcium-dependent zinc-containing endopeptidases, which are responsible for the tissue remodeling and degradation of the extracellular matrix (ECM), including collagens, elastins, gelatin, matrix glycoproteins, and proteoglycan. They are regulated by hormones, growth factors, and cytokines, and are involved in ovarian functions. MMPs are excreted by a variety of connective tissue and pro-inflammatory cells including fibroblasts, osteoblasts, endothelial cells, macrophages, neutrophils, and lymphocytes. These enzymes are expressed as zymogens, which are subsequently processed by other proteolytic enzymes (such as serine proteases, furin, plasmin, and others) to generate the active forms. Matrix metalloproteinases are considered as promising targets for the treatment of cancer due to their strong involvement in malignant pathologies. Clinical/preclinical studies on MMP inhibition in tumor models brought positive results raising the idea that the development of strategies to inhibit MMPs may be proved to be a powerful tool to fight against cancer. However, the presence of an inherent flexibility in the MMP active-site limits dramatically the accurate modeling of MMP-inhibitor complexes. The interest in the application of quantitative structure-activity relationships (QSARs) has steadily increased in recent decades and we hope it may be useful in elucidating the mechanisms of chemical-biological interactions for this enzyme. In the present review, an attempt has been made to explore the in-depth knowledge from the classification of this enzyme to the clinical trials of their inhibitors. A total number of 92 QSAR models (44 published and 48 new formulated QSAR models) have also been presented to understand the chemical-biological interactions. QSAR results on the inhibition of various compound series against MMP-1, -2, -3, -7, -8, -9, -12, -13, and -14 reveal a number of interesting points. The most important of these are hydrophobicity and molar refractivity, which are the most important determinants of the activity.
Optimization of sparse matrix-vector multiplication on emerging multicore platforms

We are witnessing a dramatic change in computer architecture due to the multicore paradigm shift, as every electronic device from cell phones to supercomputers confronts parallelism of unprecedented scale. To fully unleash the potential of these systems, the HPC community must develop multicore specific-optimization methodologies for important scientific computations. In this work, we examine sparse matrix-vector multiply (SpMV) - one of the most heavily used kernels in scientific computing - across a broad spectrum of multicore designs. Our experimental platform includes the homogeneous AMD quad-core, AMD dual-core, and Intel quad-core designs, the heterogeneous STI Cell, as well as one of the first scientific studies of the highly multithreaded Sun Victoria Falls (a Niagara2 SMP). We present several optimization strategies especially effective for the multicore environment, and demonstrate significant performance improvements compared to existing state-of-the-art serial and parallel SpMV implementations. Additionally, we present key insights into the architectural trade-offs of leading multicore design strategies, in the context of demanding memory-bound numerical algorithms.
Cinchonine and thiourea

In this viewpoint, we discuss the seminal work contributed by Dixon, who reported the first use of a bifunctional cinchona-derived thiourea organocatalyst for the enantioselective conjugate addition of malonate esters to nitroalkenes. Since then, this class of catalysts has been extensively utilized in a variety of fundamental transformations. We also highlight here some of the representative studies performed since the publication of this milestone work in 2005.
Step-wise emotion recognition using concatenated-HMM

Human emotion is an important part of human-human communication, since the emotional state of an individual often affects the way that he/she reacts to others. In this paper, we present a method based on concatenated Hidden Markov Model (co-HMM) to infer the dimensional and continuous emotion labels from audio-visual cues. Our method is based on the assumption that continuous emotion levels can be modeled by a set of discrete values. Based on this, we represent each emotional dimension by step-wise label classes, and learn the intrinsic and extrinsic dynamics using our co-HMM model. We evaluate our approach on the Audio-Visual Emotion Challenge (AVEC 2012) dataset. Our results show considerable improvement over the baseline regression model presented with the AVEC 2012.
Access to Medicine in the Global Economy: International Agreements on Patents and Related Rights

I. Background 1. From Conception to Commercial Success 2. A Limitation on the Patent Right to Exclude "Parallel Imports": An Introduction to International Exhaustion II. The Current Framework 3. An Introduction to TRIPS 4. Freedom Under TRIPS: India as an Example 5. Compulsory Licensing Under TRIPS: An Introduction 6. Compulsory License Case Study: An Introduction to Competing Patent Perspectives 7. Complicated Compulsory Licenses: The Waiver/Article 31bis "Solution" III. The Evolving Framework 8. An Overview of "TRIPS-Plus" Standards 9. Beyond Patents: Protecting Drugs Through Regulatory Laws 10. Suspensions of In Transit Generic Drugs: A Case Study of Competing Perspectives 11. A Historical View of Access to Medicine Through the Lens of Patent Perspectives 12. Looking Towards the Future
Hydrogen diffusion coefficients through Inconel 718 in different metallurgical conditions

Abstract We report hydrogen permeation studies through cold rolled, solutionized, and precipitation hardened Inconel 718 foils. The effective hydrogen diffusion coefficient is considerably higher (5.3–6.8 × 10−11 cm2/s) for the solutionized Inconel 718 than for either the cold rolled (3.3–4.2 × 10−11 cm2/s) or precipitation hardened (2.1–2.9 × 10−11 cm2/s) specimens. Microstructural studies indicate that the reduced hydrogen diffusion coefficients in the latter specimens arise from hydrogen trapping at dislocations and precipitates that are present at much lower concentrations in the solutionized specimens. Also, repeated permeation transients provide evidence for irreversible hydrogen trapping in the cold rolled and precipitation hardened specimens, but such effects are insignificant in the solutionized specimens.
1-(1-Naphthyl)piperazine as a novel template for 5-HT6 serotonin receptor ligands

4-Sulfonyl analogs of 1-(1-naphthyl)piperazine bind at human 5-HT6 receptors and represent a novel class of human 5-HT6 receptor ligands.
Crystals from categorified quantum groups

We study the crystal structure on categories of graded modules over algebras which categorify the negative half of the quantum Kac-Moody algebra associated to a symmetrizable Cartan data. We identify this crystal with Kashiwara’s crystal for the corresponding negative half of the quantum Kac-Moody algebra. As a consequence, we show the simple graded modules for certain cyclotomic quotients carry the structure of highest weight crystals, and hence compute the rank of the corresponding Grothendieck group.
HOW TO ACCEPT WEGNER'S ILLUSION OF CONSCIOUS WILL AND STILL DEFEND MORAL RESPONSIBILITY

In The Illusion of Conscious Will, Daniel Wegner (2002) argues that our commonsense belief that our conscious choices cause our voluntary actions is mistaken. Wegner cites experimental results that suggest that brain processes initiate our actions before we become consciously aware of our choices, showing that we are systematically wrong in thinking that we consciously cause our actions. Wegner's view leads him to conclude, among other things, that moral responsibility does not exist. In this article I propose some ways that traditional philosophical defenders of moral responsibility, both compatibilists and libertarians, might accept Wegner's empirical premise regarding the will but amend their theories so that they may reject his conclusion regarding moral responsibility.
A delay metric for RC circuits based on the Weibull distribution

Physical synthesis optimizations require fast and accurate analysis of RC networks. Elmore first proposed matching circuit moments to a probability density function (PDF), which led to widespread adoption of his simple and fast metric. The more recently proposed PRIMO and H-gamma metrics match the circuit moments to the PDF of a Gamma statistical distribution. We instead propose to match the circuit moments to a Weibull distribution and derive a new delay metric called Weibull-based delay (WED). The primary advantages of WED over PRIMO and H-gamma are its efficiency and ease of implementation. Experiments show that WED is robust and has satisfactory accuracy at both near- and far-end nodes.
Unequal Treatment or Uneven Consequence: A Content Analysis of Americans with Disabilities Act Title I Disparate Impact Cases from 1992 – 2012

This study identified patterns and trends of litigation in all reported U.S. Appellate Court ADA cases charged under the theory of disparate impact (unintentional discrimination) from 1992 through 2012. The results produced four themes: accommodation(s); workplace culture, norms, and policies; judicial process; and policy space; and three relationships: gap-filling, weighing and balancing, and maintaining status quo versus effecting social change. The results may provide information about the types of workplace policies and procedures that are most frequently litigated. Disability scholars, advocates, and practitioners may be able to use the information to develop education and outreach strategies for employers on best practices for hiring, accommodating, and promoting employees with disabilities. The results may also be used to educate and inform advocates about the process of litigation. A greater understanding of how judges make decisions in a subset of ADA cases may increase employees with disabilities' ability to self-advocate in the workplace.
"A Special Kind of Downsizing: An Assessment of Union Member Reaction to Bumping"

The present study investigated the impact of bumping on union member (N = 100) perceptions of job security, job satisfaction, organizational commitment, union commitment and organizational justice. Analysis revealed a negative correlation between bumping experience and organizational commitment and job satisfaction (at the .05 level). There was a similar negative relationship between bumping and both union commitment and organizational justice at the .10 level. MANCOVA found that organizational commitment and job satisfaction levels were higher for union members without bumping experience versus those with either direct or indirect bumping experience. No significant differences were found on any variable between union members who were directly involved in bumping and those who were indirectly involved.
The Hull and White Model of the Short Rate: An Alternative Analytical Representation

Hull and White extend Ho and Lee’s no-arbitrage model of the short interest rate to include mean reversion. This addition eliminates the problem of negative interest rates and has found wide application. To implement their model, Hull and White employ a sequential search process to identify the mean interest rate in a trinomial lattice at each date. In this article we extend Hull and White’s work by developing an analytical solution for the mean interest rate at each date. This solution applies equally well to trinomial lattices, interest rate trees, and Monte Carlo simulation. We illustrate the analytical result by applying it to an example originally used by Hull and White and then for valuing an option on a bond. Vasicek (1977) initiated a stream of research into the evolution of interest rates that produced analytically tractable valuation expressions. The values produced by this model are not consistent with market prices. Ho and Lee (1986) address this disadvantage by introducing a no-arbitrage model of the evolution of interest rates based on market interest rates and their volatilities. Heath, Jarrow, and Morton (1992) extend the Ho-Lee model of the normally distributed spot interest rate to incorporate the entire structure of forward rates. Black, Derman, and Toy (1990) and Black and Karasinski (1991) add a second class of no-arbitrage models, based on the assumption that interest rates are log-normally distributed. Hull and White (1990, 1993, 1994, 1996) combine Ho and Lee’s model with Vasicek’s idea of mean-reverting interest rates to eliminate the probability of negative rates. As Hull and White describe this extended model, it requires a search process to identify the level of interest rates at each date and forward induction. Nevertheless, the Hull
Packing multiway cuts in capacitated graphs

We consider the following "multiway cut packing" problem in undirected graphs: given a graph G = (V, E) and k commodities, each corresponding to a set of terminals located at different vertices in the graph, our goal is to produce a collection of cuts {E1, ..., Ek} such that Ei is a multiway cut for commodity i and the maximum load on any edge is minimized. The load on an edge is defined to be the number of cuts in the solution containing the edge. In the capacitated version of the problem the goal is to minimize the maximum relative load on any edge---the ratio of the edge's load to its capacity. Multiway cut packing arises in the context of graph labeling problems where we are given a partial labeling of a set of items and a neighborhood structure over them, and the goal, informally stated, is to complete the labeling in the most consistent way. This problem was introduced by Rabani, Schulman, and Swamy (SODA'08), who developed an O(log n/log log n) approximation for it in general graphs, as well as an improved O(log2k) approximation in trees. Here n is the number of nodes in the graph. We present the first constant factor approximation for this problem in arbitrary undirected graphs. Our LP-rounding-based algorithm guarantees a maximum edge load of at most 8OPT + 4 in general graphs. Our approach is based on the observation that every instance of the problem admits a laminar solution (that is, no pair of cuts in the solution crosses) that is near-optimal.
Asymptotic theory for differentiated products demand models with many markets

Abstract This paper develops asymptotic theory for differentiated product demand models with a large number of markets T . It takes into account that the predicted market shares are approximated by Monte Carlo integration with R draws and that the observed market shares are approximated from a sample of N consumers. The estimated parameters are T consistent and asymptotically normal as long as R and N grow fast enough relative to T . Both approximations yield additional bias and variance terms in the asymptotic expansion. I propose a bias corrected estimator and a variance adjustment that takes the leading terms into account. Monte Carlo simulations show that these adjustments should be used in applications to avoid severe undercoverage caused by the approximation errors.
Performance evaluation: a structured approach

Computer systems are expensive in terms of development, acquisition and maintenance. The efficient and effective system appears to be the exception rather than the rule. Concern for system improvement is voiced by almost every computer-related management or technical support group. The types and amounts of data which can be gathered through hardware and software monitors appear to be ever increasing. A bewildering array of papers and proceedings are published every year and the problems of analyzing computer systems are described with loving detail.
Segregation, Rent Control, and Riots: The Economics of Religious Conflict in an Indian City

Religious conflict is an important problem in many ethnically diverse countries (Horowitz 1985). A growing literature in economics suggests that conflict over resources is frequently at the root of such violence (see, for instance, Esteban and Ray 2007). A number of recent empirical papers provide evidence that negative economic shocks to a community, and the consequent struggle for control over resources, can help explain the eruption of historic tensions into acts of violence (Miguel et al. 2004, Oster 2004 and Miguel 2005). We explore this link further by studying the relationship between Hindu-Muslim violence and living arrangements – in particular residential segregation – within cities in India. That is, conditional on city-level demographics and the overall degree of ethnic tension, what are the characteristics of specific locations within a city where communal violence tends to emerge and what can this tell us about why some neighborhoods erupt in this manner at certain points in time? Communal violence at the neighborhood-level
Roundoff error analysis of the discrete Wigner distribution using fixed-point arithmetic

The issue of roundoff noise effects in the implementation of the discrete Wigner distribution using fixed-point arithmetic is addressed. The sign-magnitude number representation is assumed throughout the analysis. The measure of roundoff noise effects in an algorithm is the output noise-to-signal ratio. Using a statistical model, an analytical expression of the noise-to-signal ratio is derived as a function of the wordlength b and the transform length N. The noise-to-signal ratio is obtained by evaluating the signal and noise powers at different points in the algorithm, then reflecting to the output both signal and noise powers. Based on the derived noise-to-signal ratio is is noted that if the transform length is doubled, then) one additional bit is required in the wordlength to maintain a constant noise-to-signal ratio. It is demonstrated through the software simulations that the predicted noise-to-signal ratio is a good closed-form estimate of the 'true' roundoff error. It is also found from the simulation that the wordlength b and the transform length N=2/sup v/ must satisfy the condition b-v>or=4. >
Synthesis of Novel 3,7-Dihydro-purine-2,6-dione Derivatives

Forty-six novel 3,7-dihydro-purine-2,6-dione derivatives (substituted xanthines) with great structural diversity were synthesized for biological activity screening. Three series of substituted xanthine analogs have been prepared in moderate to excellent yields.
Influence of Black Annealing Oxide Scale on the Anodic Behavior of Alloy 22

The resistance of Alloy 22 (N06022) to localized corrosion, mainly crevice corrosion, has been extensively investigated in the last few years. The effect of influencing variables such as temperature, applied potential, chloride concentration and nitrate inhibitor concentration have been addressed previously. At this time, it was important to address the effect an oxide film or scale that forms during the high temperature annealing process or solution heat treatment (SHT) and its subsequent water quenching. Electrochemical tests such as cyclic potentiodynamic polarization (CPP) have been carried out to determine the repassivation potential for localized corrosion and to assess the mode of attack on the specimens. Tests have been carried out in parallel using mill annealed (MA) specimens free from oxide on the surface. The comparative testing was carried out in six different electrolyte solutions at temperatures ranging from 60 C to 100 C. Results show that the repassivation potential of the specimens containing the black anneal oxide film on the surface was practically the same or higher as the repassivation potential for oxide-free specimens.
The complexity of welfare maximization in congestion games

We investigate issues of complexity related to welfare maximization in congestion games. In particular, we provide a full classification of complexity results for the problem of finding a minimum cost solution to a congestion game, under the model of Rosenthal. We consider both network and general congestion games, and we examine several variants of the problem concerning the structure of the game and the properties of its associated cost functions. Many of these problem variants turn out to be NP-hard, and some are hard to approximate to within any finite factor, unless P = NP. We also identify several versions of the problem that are solvable in polynomial time. © 2011 Wiley Periodicals, Inc. NETWORKS, 2012 © 2012 Wiley Periodicals, Inc.
Tyrosine-derived quinone cofactors

Copper amine oxidases (CAOs) and lysyl oxidase (LOX) both contain Cu2+ and quinone cofactors that are derived from a tyrosine residue in the active site. In CAOs, the cofactor is 2,4,5-trihydroxyphenylalanine quinone (TPQ), and in LOX it is lysine tyrosyl quinone (LTQ). The mechanism of oxidative deamination by CAOs is well understood, but there is a controversy surrounding the role of Cu2+ in cofactor reoxidation. The chemistry of LTQ in LOX, by contrast, has not been as extensively studied. This Account discusses the strategies that CAOs have evolved to control the mobility of TPQ to optimize activity. In addition, some recent studies on CAOs whose active-site Cu2+ has been replaced with Co2+ or Ni2+ are summarized. Finally, there is a discussion on the properties of a model compound of LTQ and their relevance to the chemistry of LOX.
Real Estate Prices, Borrowing Constraints and Business Cycles A Study of the Japanese Economy

This paper investigates the causes of business cycle fluctuations that Japan experienced over the period 1980 to 2000. To this end, I build a dynamic general equilibrium model with endogenous borrowing constraints where business cycle fluctuations are the result of TFP fluctuations and investment frictions. I identify land tax changes since 1984 as a possible source of investment frictions, the idea being that given a strong preference for debt-financing and widespread use of land as collateral in Japan, land tax changes will cause fluctuations in land price that can potentially affect output and investment by affecting borrowing capacity of firms. Calibrating the model using Japanese data and feeding in observed TFP and land taxes one by one and in unison, I find that TFP and land tax fluctuations can significantly account for observed fluctuations in output, but cannot account for land price fluctuations unless agents expect land tax changes to be permanent. I further identify redistribution of land holding between commercial and residential uses in response to land tax and TFP changes as an important channel through which the effect of these external fluctuations on output gets amplified. Observed data of land use in Japan provides evidence of such redistribution.
Founding-Family Ownership and Firm Performance: Evidence from the S&P 500

We investigate the relation between founding-family ownership and firm performance. We find that family ownership is both prevalent and substantial; families are present in one-third of the S&P 500 and account for 18 percent of outstanding equity. Contrary to our conjecture, we find family firms perform better than nonfamily firms. Additional analysis reveals that the relation between family holdings and firm performance is nonlinear and that when family members serve as CEO, performance is better than with outside CEOs. Overall, our results are inconsistent with the hypothesis that minority shareholders are adversely affected by family ownership, suggesting that family ownership is an effective organizational structure. FOUNDING-FAMILYOWNERSHIPAND CONTROL in public U.S. firms is commonly perceived as a less efficient, or at the very least, a less profitable ownership structure than dispersed ownership. Fama and Jensen (1983) note that combining ownership and control allows concentrated shareholders to exchange profits for private rents. Demsetz (1983) argues that such owners may choose nonpecuniary consumption and thereby draw scarce resources away from profitable projects. Shleifer and Vishny (1997) observe that the large premiums associated with superiorvoting shares or control rights provide evidence that controlling shareholders seek to extract private benefits from the firm. More generally, firms with large, undiversified owners such as founding families may forgo maximum profits because they are unable to separate their financial preferences with those of outside owners.1 Families also often limit executive management positions to family
Implicit application of non-reflective boundary conditions for Navier–Stokes equations in generalized coordinates

The non-re∞ective boundary conditions for Navier-Stokes equations originally suggested by Poinsot and Lele[1] in Cartesian coordinates are extended to generalized coordinates. The boundary conditions are implicitly coupled with the Navier-Stokes ∞ow solver in the inner domain. The calculations are conducted for a subsonic vortex propagating ∞ow and the steady and unsteady transonic inlet-difiuser ∞ows. The results indicate that the present method is accurate and robust, and the non-re∞ective boundary conditions are essential for unsteady ∞ow calculations.
Photoinduced electron transfer between aromatic amines and alkyl nitriles.

Abstract Irradiation of aromatic amines in the presence of alkyl nitriles leads to efficient electron-transfer reactions, resulting in amination or alkylation of the aromatic moieties.
Theoretical analysis of correlation-based quality measures for weighted averaging image fusion

Recently introduced correlation-based quality measures have received lots of attention due to the fact that they do not need ground-truth reference images to evaluate the performance of image fusion algorithms. In this paper we focus on theoretical analysis of these correlation-based quality measures when they are used to judge the performance of weighted averaging image fusion algorithms. The purpose of this paper is to rigorously prove that the correlation-based quality measures have some undesired behavior under certain conditions. We employ a statistical model for the observed sensor images and study the properties of these correlation-based quality measures. Our analysis shows that when we change the power of the desired signal or the noise in the input images, these correlation-based quality measures exhibit bad behaviors in some cases, indicating higher quality when lower quality is evident. The sufficient conditions for when the undesired behavior occur and the intuitive explanation for our observation are given in this paper. Investigations with real images also demonstrate the utility of the theoretical analysis, by illustrating its predictive capabilities.
From electromagnetically induced transparency to superscattering with a single structure: a coupled-mode theory for doubly resonant structures

We observe from simulations that a doubly resonant structure can exhibit spectral behavior analogous to electromagnetically induced transparency, as well as superscattering, depending on the excitation. We develop a coupled-mode theory that explains this behavior in terms of the orthogonality of the radiation patterns of the eigenmodes. These results provide insight in the general electromagnetic properties of photonic nanostructures and metamaterials.
Bulk Fe-Based Metallic Glass with Extremely Soft Ferromagnetic Properties

The authors have investigated the DC and AC magnetic properties of a bulk glassy Fe{sub 65.5}Cr{sub 4}Mo{sub 4}Ga{sub 4}P{sub 12}B{sub 5.5}C{sub 5} alloy. In the annealed state the alloy has coercivity H{sub C} and maximum DC permeability {mu}{sub m} of approximately 0.4 A/m (5 mOe) and 2.8 x 10{sup 5}, comparable to those found in annealed zero-magnetostriction Co-based alloys. The low H{sub C} found in the bulk glassy alloy is attributed to the low ratio of surface-roughness to sample thickness, and low residual internal-stress. The total power loss in the annealed bulk glass is about one order of magnitude lower than that of rapidly quenched Fe-based glassy ribbons. This is attributed to a low anomalous eddy-current loss.
Evaluating reliability improvements of fault tolerant array processors using algorithm-based fault tolerance

Algorithm-based fault tolerance (ABFT) is used to provide low-cost error protection for VLSI processor arrays used in real-time digital signal processing. The main objective of incorporating an ABFT technique in a processor array is to improve its reliability. All previous approaches on ABFT are evaluated in terms of their error detecting/correcting capabilities, the reliability improvement has never been addressed. In this paper, we develop a stochastic model for an array processor incorporating ABFT that takes the behavior of transient/intermittent failures and hardware overhead into account. This model is then used to evaluate reliability and reliability improvements of several existing ABFT techniques that tolerate single faults. Therefore, a user can evaluate a number of ABFT techniques and make a trade-off between reliability and cost prior to the implementation. Moreover, we have conducted extensive simulation experiments and the simulation results validate the proposed model.
A Sentimental Education: Sentiment Analysis Using Subjectivity Summarization Based on Minimum Cuts

Sentiment analysis seeks to identify the viewpoint(s) underlying a text span; an example application is classifying a movie review as "thumbs up" or "thumbs down". To determine this sentiment polarity, we propose a novel machine-learning method that applies text-categorization techniques to just the subjective portions of the document. Extracting these portions can be implemented using efficient techniques for finding minimum cuts in graphs; this greatly facilitates incorporation of cross-sentence contextual constraints.
A Rapid Aerodynamic Design Procedure Based on Artificial Neural Networks

An aerodynamic design procedure that uses neural networks to model the functional behavior of the objective function in design space has been developed. This method incorporates several improvements to an earlier method that employed a strategy called parameter-based partitioning of the design space in order to reduce the computational costs associated with design optimization. As with the earlier method, the current method uses a sequence of response surfaces to traverse the design space in search of the optimal solution. The new method yields significant reductions in computational costs by using composite response surfaces with better generalization capabilities and by exploiting synergies between the optimization method and the simulation codes used to generate the training data. These reductions in design optimization costs are demonstrated for a turbine airfoil design study where a generic shape is evolved into an optimal airfoil.
Active semi-supervised learning using submodular functions

We consider active, semi-supervised learning in an offline transductive setting. We show that a previously proposed error bound for active learning on undirected weighted graphs can be generalized by replacing graph cut with an arbitrary symmetric submodular function. Arbitrary non-symmetric sub-modular functions can be used via symmetrization. Different choices of submodular functions give different versions of the error bound that are appropriate for different kinds of problems. Moreover, the bound is deterministic and holds for adversarially chosen labels. We show exactly minimizing this error bound is NP-complete. However, we also introduce for any submodular function an associated active semi-supervised learning method that approximately minimizes the corresponding error bound. We show that the error bound is tight in the sense that there is no other bound of the same form which is better. Our theoretical results are supported by experiments on real data.
Automatic Generation of Persistent Formations for Multi-agent Networks Under Range Constraints

In this paper we present a collection of graph-based methods for determining if a team of mobile robots, subjected to sensor and communication range constraints, can persistently achieve a specified formation. What we mean by this is that the formation, once achieved, will be preserved by the direct maintenance of the smallest subset of all possible pairwise inter-agent distances. In this context, formations are defined by sets of points separated by distances corresponding to desired inter-agent distances. Further, we provide graph operations to describe agent interactions that implement a given formation, as well as an algorithm that, given a persistent formation, automatically generates a sequence of such operations. Experimental results are presented that illustrate the operation of the proposed methods on real robot platforms.