cssi/SciSciGPT-SciSciNet huggingface dataset:
Discrete relaxation techniques

Introduction to relaxation techniques Classical relaxation The labeling problem The formulation of discrete relaxation Networks of constraints Applications of discrete relaxation Hierarchical constraint processes Parallel discrete relaxation algorithms VLSI architectures for discrete relaxation.
How Far Away Is Africa? Technological Spillovers to Agriculture and Productivity

Productivity change, as measured by total factor productivity growth, is vital to growth in the agricultural sector, and is therefore of enormous importance to less developed countries (LDCs). Adoption of technology (as measured by the creation of domestic inventions or the use of foreign inventions) is a major source of productivity growth and a large factor in determining capital investment prospects in agriculture. However, many developing countries do not have the institutions, particularly the Intellectual Property Rights (IPR) systems, to encourage domestic invention or the transfer of foreign technology. For example, this is the case in Africa where patent systems do not exist or are of marginal importance. The traditional remedy to inadequate incentives for private invention has beeii to build public sector invention systems for agriculture, particularly for plant and animal breeding and related inventions.
Setting incentives for scientists who engage in research and other activities: an application of principal-agent theory

The objective of this paper is to develop an optimal incentive system for multitaskingscientists in universities or professors under repeat contracting. With the aid of a principalagentmodel under repeat contracting, we show that (i) when a second task is assigned to aprofessor and the two tasks are related, the size of the optimal incentive rate for the first task isreduced in some situations but not others relative to that of a single task, (ii) with an increasein the noise in the technical relationship of the second task or imprecision in outputmeasurement, the optimal incentive rate for that task is reduced and for the first task may bereduced or increased , (iii) with greater efficiency of the professor in producing the secondoutput, as reflected in ability relative to cost of effort, the optimal incentive rate for the firsttask generally decreases, (iv) if the output of the professor’s two tasks are negativelycorrelated then the optimal incentive rate on the first task declines as the size of thiscorrelation increases. The size of the guarantee is always reduced as the professor’s ability fora task increases, but is increased as his cost of effort, noisiness of the technology ormeasurement of output, or correlation between the two outputs increases. It is also possiblethat, as a professor undertakes several difficult-to-measure tasks, the incentive rate will bereduced to the point that an optimal compensation system will involve only a guaranteedsalary, which is a very weak incentive for effort. Selective audits may be useful in thesesituations.
An analysis of the determinants of flood damages

In this paper we analyze mortality caused by 2,194 large flood events between 1985 and 2008 in 108 countries. Unlike previous studies that looked at natural-disaster mortality, we find that year-to-year changes in income and institutional determinants of vulnerability do not affect flood mortality directly. Income and institutions influence mortality only indirectly, through their impact on the intensity and frequency of floods. Population exposure affects the number of deaths both directly and indirectly. Higher population exposure results in more deaths once the flood has occurred, but it is associated with smaller floods. In developing countries it also reduces the count of floods.
Searching for Work With a Criminal Record

To date, researchers have been very attentive to how the stigma of criminality informs employers’ hiring decisions, and, in the process, diminishes the employment opportunities afforded to jobseekers so stigmatized. Few researchers, however, have investigated the extent to which criminal records also shape jobseekers’ search strategies in ways that either attenuate or amplify the effects of their negative credentials. We fill this gap in the literature by investigating how arrest, conviction, and incarceration affect the scope of jobseekers’ search efforts as well as the specific methods they deploy. We then examine the extent to which gaps in job search success can be attributed to stigmatized jobseekers’ search strategies. Analysis of the NLSY97 reveals that arrestees and former prisoners (but not ex-convicts) are disadvantaged both by the scope of their search efforts and by the specific methods they use. Arrestees are less likely than non-offenders to find work during the search process because they use fewer search methods, and because they over-invest in ineffective methods while under-investing in more effective methods. Although former prisoners are also disadvantaged by over- and under-investing, we primarily attribute their lower odds of search success to the differential impacts of their search strategies. Even when the scope and nature of their searches mirror those of non-offenders, their searches are less likely to end successfully. By bringing “search” into debates on punishment and inequality, we provide a new and complementary way to understand how a criminal record negatively affects jobseekers’ chances of finding work.
Decision Tree Modeling with Relational Views

Data mining is a useful decision support technique that can be used to discover production rules in warehouses or corporate data. Data mining research has made much effort to apply various mining algorithms efficiently on large databases. However, a serious problem in their practical application is the long processing time of such algorithms. Nowadays, one of the key challenges is to integrate data mining methods within the framework of traditional database systems. Indeed, such implementations can take advantage of the efficiency provided by SQL engines.In this paper, we propose an integrating approach for decision trees within a classical database system. In other words, we try to discover knowledge from relational databases, in the form of production rules, via a procedure embedding SQL queries. The obtained decision tree is defined by successive, related relational views. Each view corresponds to a given population in the underlying decision tree. We selected the classical Induction Decision Tree (ID3) algorithm to build the decision tree. To prove that our implementation of ID3 works properly, we successfully compared the output of our procedure with the output of an existing and validated data mining software, SIPINA. Furthermore, since our approach is tuneable, it can be generalized to any other similar decision tree-based method.
E FATALS-a computer program for the analysis of electrocutions in the mining industry

The authors describe an application program, known as E FATALS, which was developed to facilitate analysis of the Mine Safety and Health Administration database of electrical fatalities in mining. E FATALS in a menu-driven and user-friendly program than can be executed on DOS-based personal computers. The advantages of using E FATALS for performing safety analyses are stated, and some examples of such usage are given. >
Crisis and contagion in East Asia : nine lessons

The recent crises originating in Mexico (1994), Thailand (1997), and Russia (1998) were all transmitted to the rest of the world. The shocks affected both neighboring and remote countries, and both emerging and developed markets. The cross-country transmission of crises and shocks is often called “contagion.” In this paper, we first investigate the origins of the Asian crisis and its contagion. Second, we examine the different channels of contagion. Third, we discuss the alternative policy recommendations to prevent and manage future crises and contagion, once they occur.
Analysis and classification of errors made by teams during neonatal resuscitation.

Abstract Aim The Neonatal Resuscitation Program (NRP) algorithm serves as a guide to healthcare professionals caring for neonates transitioning to extrauterine life. Despite this, adherence to the algorithm is challenging, and errors are frequent. Information-dense, high-risk fields such as air traffic control have proven that formal classification of errors facilitates recognition and remediation. This study was performed to determine and characterize common deviations from the NRP algorithm during neonatal resuscitation. Methods Audiovisual recordings of 250 real neonatal resuscitations were obtained between April 2003 and May 2004. Of these, 23 complex resuscitations were analyzed for adherence to the contemporaneous NRP algorithm and scored using a novel classification tool based on the validated NRP Megacode Checklist. Results Seven hundred eighty algorithm-driven tasks were observed. One hundred ninety-four tasks were completed incorrectly, for an average error rate of 23%. Forty-two were errors of omission (28% of all errors) and 107 were errors of commission (72% of all errors). Many errors were repetitive and potentially clinically significant: failure to assess heart rate and/or breath sounds, improper rate of positive pressure ventilation, inadequate peak inspiratory and end expiratory pressures during ventilation, improper chest compression technique, and asynchronous PPV and CC. Conclusions Errors of commission, especially when performing advanced life support interventions such as positive pressure ventilation, intubation, and chest compressions, are common during neonatal resuscitation and are sources of potential harm. The adoption of error reduction strategies capable of decreasing cognitive and technical load and standardizing communication – strategies common in other industries – should be considered in healthcare.
Rings, Radicals, and Regeneration: the Early Years of a Bioorganic Laboratory

This Perspective provides an overview of the progress in two of the original programs in my research group focused on the biosynthesis of the antibiotics nisin, lacticin 481, fosfomycin, and bialaphos. The path from start-up funds to tenure and beyond offers insights into the opportunities realized and missed along the road.
Pole Placement Methods for Multivariable Control of Robotic Manipulators

In current industrial practice an independent servo loop is used for the control of each joint of a robot arm. Dynamic coupling among subsystems as well as changes in the effective loading are either neglected or cancelled by feedforward compensation. These dynamic effects are often significant enough to cause the motion to be jerky and uncoordinated when they are neglected. In this paper efficient methods for multivariable control of robotic manipulators based upon pole placement by state feedback are presented as an improved method of path control. An example of the computations for a three-link robot arm and computer simulation experiments are given.
Augmented reality e-commerce assistant system: trying while shopping

Traditional electronic commerce (e-commerce) is limited, because it cannot provide enough direct information about products to online consumers. The technology presented in this paper shows how Augmented Reality (AR) can be used to help overcome the limitations and enhance e-commerce systems. An e-commerce assistant tool was developed, using user-centered design principles. The tool was developed as an Internet plugin, so it can be used on different kinds of computers and handheld devices. A usability experiment was conducted, to compare the developed AR e-commerce assistant tool with traditional e-commerce and Virtual Reality (VR) e-commerce systems. Results show that an AR e-commerce system can provide more direct information about products than traditional or VR e-commerce systems.
Exchange Rate Management and Crisis Susceptibility: A Reassessment

This paper revisits the bipolar prescription for exchange rate regime choice and asks two questions: Are the poles of hard pegs and pure floats still safer than the middle? And where to draw the line between safe floats and risky intermediate regimes? Our findings, based on a sample of 50 emerging market economies over 1980–2011, show that macroeconomic and financial vulnerabilities are significantly greater under less flexible exchange rate regimes—including hard pegs—as compared with floats. Although not especially susceptible to banking or currency crises, hard pegs are significantly more prone to growth collapses, suggesting that the security of the hard end of the prescription is largely illusory. Intermediate regimes as a class are the most susceptible to crises, but “managed floats”—a subclass within such regimes—behave much more like pure floats, with significantly lower risks and fewer crises. “Managed floating,” however, is a nebulous concept; a characterization of more crisis-prone regimes suggests no simple dividing line between safe floats and risky intermediate regimes.
The incidence of intrapartum fetal distress with advancing gestational age

A total of 679 fetal monitoring records were carefully reviewed in order to determine the incidence of occurrence of late and variable deceleration patterns with respect to advancing gestational age. No statistically significant increase in occurrence of these patterns could be detected in gestations that progressed beyond 42 weeks. The previously held concept that routine prophylactic intervention in gestations of 42 weeks or more must be challenged.
Deploying Homeland Security Technology

Question: What do the Department of Homeland Security, Intel, and Disney have in common? 1 Answer: The success of each depends on how efficiently they implement new technologies. Although the White House and the Congress have responded swiftly to the events of September 11, 2001, the long-term security of our Nation, and thus the success of the newly created Department of Homeland Security, will depend in a substantial way on the efficiency with which technologies relevant to homeland security are created and, more importantly, deployed.
Funeral Protests, Privacy, and the Constitution: What Is Next after Phelps?

In Snyder v. Phelps, the United States Supreme Court struck down a damages award against Reverend Fred Phelps Sr. and the Westboro Baptist Church for picketing a military funeral. Although the Court asserted that its holding was narrow and the legal issues involved were straightforward, this Article argues that Phelps ultimately raises more questions than it answers and almost guarantees increased confusion in First Amendment jurisprudence. The Court in Phelps explained that the First Amendment prohibits tort damages when the comments at issue involve matters of public concern, yet failed to explain whether private speech that was juxtaposed with public, political speech also warranted the protection of the First Amendment. The Court also neglected to provide guidance on how its holding fits into the current defamation and privacy jurisprudence; in addition, it left unanswered pertinent questions about the constitutionality of a growing number of funeral protest statutes. Lower courts are likely to feel frustrated by this decision and, consequently, a relatively clear area of the law is likely to become muddled. This article is available in American University Law Review: http://digitalcommons.wcl.american.edu/aulr/vol61/iss2/5 STRASSER.OFF.TO.PRINTER (DO NOT DELETE) 3/26/2012 8:08 PM 279 FUNERAL PROTESTS, PRIVACY, AND THE CONSTITUTION: WHAT IS NEXT AFTER PHELPS?
Real Exchange Rate Fluctuations and Endogenous Tradability

This paper examines, empirically and theoretically, the sectoral decomposition of the volatility of real exchange rates. For the purpose of this decomposition, goods are classified as being traded or nontraded in international markets. The first part performs an empirical analysis for a broad cross section of countries. The relative price of nontraded goods to traded goods is found to be relatively more important in movements of real exchange rates of the country pairs that maintain stable nominal exchange rates. The paper goes on to construct a model with endogenous tradability to suggest an explanation for the evidence. The key features of the model are heterogeneous productivity, transport costs, and sticky wages. The nontraded sector arises from non-zero trade costs. The relative price of goods depends on productivity, transport costs, and in the short run, on the exchange rate regime. The calibration shows that the relative price of nontraded goods makes a much greater contribution to overall real exchange rate volatility under a fixed exchange rate regime than a flexible regime, as in the data. ∗Krannert Graduate School of Management, Purdue University, West Lafayette, IN 47906. Email: knaknoi@krannert.purdue.edu. I am indebted to advice and comments from David Hummels, Michael Kumhof, Laurence Lau, Douglas Laxton, Esteban Rossi-Hansberg, Slavi Slavov, Mark Wright, Kei-Mu Yi, Asaf Zussman and the participants in International Research seminar at Federal Reserve Bank of New York, NBER Summer Institute 2004, Purdue Macro seminar and Stanford Macro lunch. An earlier version of this paper appears as Stanford Institute of Economic Policy Research Discussion Paper No. 03-017, Stanford University (January, 2004).
The Privacy Analysis of Battery Control Mechanisms in Demand Response: Revealing State Approach and Rate Distortion Bounds

Demand response systems in the electricity grid, which rely on two way communication between the consumers and utility, require the transmission of instantaneous energy consumption to utilities. Perfect knowledge of a user’s power consumption profile by a utility is a violation of privacy and can be detrimental to the successful implementation of demand response systems. It has been shown that an in-home energy storage system (such as a battery/inverter) that provides a viable means to achieve the cost savings of instantaneous electricity pricing without inconvenience can also be used to hide a user’s power usage pattern. A fundamental tradeoff exists between the costs saved and the degree of privacy achievable, and in this paper, the tradeoff achievable by a finite capacity battery assuming a zero tolerance for activity delay is studied using a Markov process model for user’s demands and instantaneous electricity prices. Due to high computational complexity (continuous state-action space) of the stochastic control model, inner and upper bounds are presented on the optimal tradeoff. In particular, a class of battery charging policies based on minimizing revealing states is proposed to derive achievable privacy-cost savings tradeoff. The performance of this algorithm is compared with lower bounds derived using a greedy heuristic and upper bounds derived using an information theoretic rate distortion approach. The framework proposed is shown to be applicable even when users only desire partial information protection, such as presence/absence of activity or specific appliances they wish to hide. Numerical results based on real electricity and pricing data show that the proposed algorithm performs close to the upper bound demonstrating its efficacy.
Inverse covariance estimation for high-dimensional data in linear time and space: spectral methods for Riccati and sparse models

We propose maximum likelihood estimation for learning Gaussian graphical models with a Gaussian (l22) prior on the parameters. This is in contrast to the commonly used Laplace (l1) prior for encouraging sparseness. We show that our optimization problem leads to a Riccati matrix equation, which has a closed form solution. We propose an efficient algorithm that performs a singular value decomposition of the training data. Our algorithm is O(NT2)-time and O(NT)-space for N variables and T samples. Our method is tailored to high-dimensional problems (N ≫ T), in which sparseness promoting methods become intractable. Furthermore, instead of obtaining a single solution for a specific regularization parameter, our algorithm finds the whole solution path. We show that the method has logarithmic sample complexity under the spiked covariance model. We also propose sparsification of the dense solution with provable performance guarantees. We provide techniques for using our learnt models, such as removing unimportant variables, computing likelihoods and conditional distributions. Finally, we show promising results in several gene expressions datasets.
Development of Smart Electric Power System (SEPS) Laboratory for advanced Research and undergraduate education

In this work, the author discusses development of the Smart Electric Power System (SEPS) Laboratory at The College of New Jersey (TCNJ). The fully reconfigurable six-bus, three-phase power system hardware operates with ratings of 208VLL; (at 60 Hz) and 0.2 kW. It is composed of various synchronous generators with associated prime movers, induction motors with associated dynamometers, transformers, transmission lines, contactors, constant-impedance loads, renewable generation-emulator modules, battery storage devices, and appropriate power electronic converters. The SEPS lab significantly expands the ability of faculty and students at TCNJ to study energy problems, providing a sound foundation for the institution's small but growing power engineering program. The National Science Foundation Major Research Instrumentation Program provided external funding for the hardware.
The Formation and Evolution of Star Clusters and Galaxies

This paper addresses the questions of what we have learned about how and when dense star clusters form, and what studies of star clusters have revealed about galaxy formation and evolution. One important observation is that globular clusters are observed to form in galaxy mergers and starbursts in the local universe, which both provides constraints on models of globular cluster formation, and suggests that similar physical conditions existed when most early-type galaxies and their globular clusters formed in the past. A second important observation is that globular cluster systems typically have bimodal color distributions. This was predicted by merger models, and indicates an episodic formation history for elliptical galaxies. A third and very recent result is the discovery of large populations of intermediate age globular clusters in several elliptical galaxies through the use of optical to near-infrared colors. These provide an important link between young cluster systems observed in starbursts and mergers and old cluster systems. This continuum of ages of the metal-rich globular cluster systems also indicates that there is no special age or epoch for the formation of the metal-rich globular clusters, which comprise about half of the cluster population. The paper concludes with a brief discussion of recent results on the globular cluster – low-mass X-ray binary connection.
Robotic laparoendoscopic single site radical hysterectomy with sentinel lymph node mapping and pelvic lymphadenectomy for cervical cancer.

Objective. Laparoendoscopic single site (LESS) radical hysterectomy has been previously described but has not gained wide acceptance [1,2]. The role of sentinel lymph node (SLN) mapping in cervical cancer continues to evolve [3]. Recent advances in the single site robotic platform have made the performance of robotic LESS radical hysterectomy feasible [4]. The aim of this video is to demonstrate the feasibility of robotic LESS radical hysterectomy, with sentinel lymph node mapping and complete lymphadenectomy.
Dynamics based 3D skeletal hand tracking

Tracking the full skeletal pose of the hands and fingers is a challenging problem that has a plethora of applications for user interaction. Existing techniques either require wearable hardware, add restrictions to user pose, or require significant computation resources. This research explores a new approach to tracking hands, or any articulated model, by using an augmented rigid body simulation. This allows us to phrase 3D object tracking as a linear complementarity problem with a well-defined solution. Based on a depth sensor's samples, the system generates constraints that limit motion orthogonal to the rigid body model's surface. These constraints, along with prior motion, collision/contact constraints, and joint mechanics, are resolved with a projected Gauss-Seidel solver. Due to camera noise properties and attachment errors, the numerous surface constraints are impulse capped to avoid overpowering mechanical constraints. To improve tracking accuracy, multiple simulations are spawned at each frame and fed a variety of heuristics, constraints and poses. A 3D error metric selects the best-fit simulation, helping the system handle challenging hand motions. Such an approach enables real-time, robust, and accurate 3D skeletal tracking of a user's hand on a variety of depth cameras, while only utilizing a single x86 CPU core for processing.
A hybrid stochastic/interval approach to transmission-constrained unit commitment

This paper proposes a new transmission-constrained unit commitment method that combines the cost-efficient but computationally demanding stochastic optimization and the expensive but tractable interval optimization techniques to manage uncertainty on the expected net load. The proposed hybrid unit commitment approach applies the stochastic formulation to the initial operating hours of the optimization horizon, during which the wind forecasts are more accurate, and then switches to the interval formulation for the remaining hours. The switching time is optimized to balance the cost of unhedged uncertainty from the stochastic unit commitment against the cost of the security premium of the interval unit commitment formulation. These hybrid, stochastic, and interval formulations are compared using Monte Carlo simulations on a modified 24-bus IEEE Reliability Test System. The results demonstrate that the proposed unit commitment formulation results in the least expensive day-ahead schedule among all formulations and can be solved in the same amount of time as a full stochastic unit commitment. However, if the range of the switching time is reduced, the hybrid formulation in the parallel computing implementation outperforms the stochastic formulation in terms of computing time
Primordial Black Holes and the Asymmetrical Distribution of Short GRB Events

We review some of the expectations for Primordial Black Hole evaporation and we review the properties of short Gamma Ray Bursts. It is plausible that these GRB come from PBH evaporation. We then show that the angular distribution asymmetry recently observed by us could be due to a concentration of PBH in the Galactic Arms like the Orion arm.
Cracking the Supersolid

Recent experimental and theoretical work shows that frozen helium must have atomic disorder rather than perfect crystallinity for it to become a supersolid.
HIGH PRESSURE HUGONIOT OF SAPPHIRE

The Hugoniot of sapphire was measured for the first time above 145 GPa, from 80 GPa to 340 GPa in shock‐wave experiments using projectiles accelerated by a two stage gas gun. The transit times of the shock waves were measured either optically with a streak camera or through electrical pin contacts. The Hugoniot in this pressure range fits Us=8.74+0.96 Up in km/s.
The Right of the People or the Power of the State: Bearing Arms, Arming Militias, and the Second Amendment

There is a hidden history of the Second Amendment which is long overdue to be written. It is this: during the ratification period of 1787-1791, Congress and the states considered two entirely separate groups of amendments to the Constitution. The first group was a declaration of rights, in which the right of the people to keep and bear arms appeared. The second group, consisting of amendments related to the structure of government, included recognition of the power of states to maintain militias. The former became the Bill of Rights, while the latter was defeated. 3 Somehow, through some Orwellian rewriting (pg.132) of history, as applied to the issues of the right of the people to keep and bear arms and the state militia power, that which was defeated has become the meaning of that which was adopted.
Cohomology of the Orlik–Solomon Algebras and Local Systems

The paper provides a combinatorial method to decide when the space of local systems with nonvanishing first cohomology on the complement to an arrangement of lines in a complex projective plane has as an irreducible component a subgroup of positive dimension. Partial classification of arrangements having such a component of positive dimension and a comparison theorem for cohomology of Orlik–Solomon algebra and cohomology of local systems are given. The methods are based on Vinberg–Kac classification of generalized Cartan matrices and study of pencils of algebraic curves defined by mentioned positive dimensional components.
Global Carbon Emissions in the Coming Decades: The Case of China

China's annual energy-related carbon emissions surpassed those of the United States in 2006, years ahead of published international and Chinese forecasts. Why were forecasts so greatly in error and what drove the rapid growth of China's energy-related carbon emssions after 2001? The divergence between actual and forecasted carbon emissions underscores the rapid changes that have taken place in China's energy system since 2001. In order to build a more robust understanding of China's energy-related carbon emissions, this article reviews the role of economic restructuring, urbanization, coal dependence, international trade, and central government policies in driving emissions growth.
The Growth, Structure, and Properties of Sea Ice

On the geophysical scale sea ice is a thin, fragile, dynamic, solid layer that forms under the thermodynamic conditions that occur near the Poles. There it serves as a boundary between two much larger fluid bodies — the ocean and the atmosphere. Typical scales of interest would be 103 to 106 m. In the present paper we take a more detailed view, focusing on the ice itself at scales ranging between 100 and 10−3 m, with an occasional glimpse at a scale of 10−10 m. It is our purpose to help the reader understand the internal structure of sea ice, how this structure develops, and how it affects the bulk properties of the ice. Although this is a subject that has received little attention in comparison to similar studies of metals and ceramics, it is, in our view, very important, as many details in the behavior of sea ice are structurally controlled. The variations in structure are, in turn, determined by the environmental conditions under which the ice has formed.
Potholes on the royal road

It is still unclear how an evolutionary algorithm (EA) searches a fitness landscape, and on what fitness landscapes a particular EA will do well. The validity of the building-block hypothesis, a major tenet of traditional genetic algorithm theory, remains controversial despite its continued use to justify claims about EAs. This paper outlines a research program to begin to answer some of these open questions, by extending the work done in the royal road project. The short-term goal is to find a simple class of functions which the simple genetic algorithm optimizes better than other optimization methods, such as hill-climbers. A dialectical heuristic for searching for such a class is introduced. As an example of using the heuristic, the simple genetic algorithm is compared with a set of hillclimbers on a simple subset of the hyperplane-defined functions, the pothole functions.
How stronger patent protection in India might affect the behavior of transnational pharaceutical industries

To address questions about how stronger patent rights will affect India's pharmaceutical industry, the author simulates the effects of introducing such protection - as required by the World trade Organization Agreement on Trade-Related Intellectual Property Rights (TRIPs) - on market structure and static consumer welfare. (India must amend its current patent regime by 2005 and establish a transitional regime in the meanwhile.) The mode the author uses accounts for the complex demand structure for pharmaceutical goods. Consumers can choose among various drugs available to treat a specific disease. And for each drug, they have a choice among various differentiated brands. The author calibrates the model for two groups of drugs - quinolonnes and synthetic hypotensives - using 1992 brad-level data. In both groups, a subset of all available drugs was patent-protected in Western Europe but no India, where Indian manufacturers freely imitated them. The simulation analysis asks how the market structure for the two groups of drugs would have looked if India had granted patents for drugs. It does not take account of the fact that stronger patent protection will not apply to existing drugs and that the Indian government might be able to restrain high drug prices by imposing price controls or granting compulsory licenses. Still, the author concludes that if future drug discoveries are mainly new varieties of already existing therapeutic treatments, the effect of stronger patent protection is likely to be small, If newly discovered drugs are medicinal breakthroughs, however, prices may rise significantly above competitive levels and static welfare losses may be large. If demand is highly price-elastic, as is likely in India, profits for transnational corporations are likely to be small, but if private health insurance is permitted in India, reducing the price-sensitivity of demand, patent-holders' profits could increase substantially. In light of the fact that the TRIPS Agreement strengthens patent rights in most developing countries, pharmaceutical companies may do more research on, for example, tropical diseases.
Deterring Online Advertising Fraud through Optimal Payment in Arrears

Online advertisers face substantial difficulty in selecting and supervising small advertising partners: Fraud can be well-hidden, and limited reputation systems reduce accountability. But partners are not paid until after their work is complete, and advertisers can extend this delay both to improve detection of improper partner practices and to punish partners who turn out to be rule-breakers. I capture these relationships in a screening model with delayed payments and probabilistic delayed observation of agents' types. I derive conditions in which an advertising principal can set its payment delay to deter rogue agents and to attract solely or primarily good-type agents. Through the savings from excluding rogue agents, the principal can increase its profits while offering increased payments to good-type agents. I estimate that a leading affiliate network could have invoked an optimal payment delay to eliminate 71% of fraud without decreasing profit.
Insights on the conformational stability of collagen

This review describes work on the conformational stability of the collagen triple helix. In 1994, the structure of collagen was determined at high resolution. Since then, much work has been done on synthetic mimics of collagen that contain host-guest peptides, tethers, peptoid residues, or analogs of the prevalent 4(R)-hydroxy-L-proline residues. This work has revealed much about the chemical basis for collagen stability, and could spawn useful new biomaterials. The literature from 1994 to mid 2001 is reviewed, and 116 references are cited.
Database-backed websites

This paper describes a set of labs packaged as a tutorial and designed to teach students how to build database-backed web sites. These labs can be used within a variety of existing courses and need only three weeks to complete. Students need prerequisite knowledge of HTML, Visual Basic or VBScript, and the ability to build a simple database using Microsoft Access. The author describes three courses in which the labs have been successfully used and documents the results. Examples of final projects are included. The appendix contains the code from one lab exercise. Student handouts can be downloaded from the tutorial website, and an instructor's guide and lab solutions are available from the author.
Why We Don’t Need Quantum Planetary Dynamics: Decoherence and the Correspondence Principle for Chaotic Systems

Is the correspondence principle valid for quantum systems whose classical counterparts are chaotic? This question has been at the center of a debate that has taken place in recent years within the community of scientists interested in quantum chaos [4,17–20,33]. In this paper we will argue that the apparent failure of the correspondence principle is cured by decoherence, which is an essential ingredient to properly define a classical limit. We shall begin by schematically presenting the problem. Subsequently, we shall sketch the solution provided by decoherence.
Do middle-income countries continue to have the ability to deal with the global financial crisis ?

This paper introduces an"index of macroeconomic space"-- demonstrating the ability of a country to run a countercyclical fiscal policy or a fiscal stimulus at any point in time -- to show how a sample of 20 mostly middle-income countries had entered the 2008 global financial crisis with different initial conditions that, in turn, determined their ability to respond to this crisis. Since 2008, many have implemented expansionary fiscal policies and have used up available macroeconomic space. Most have had to resort to increased borrowing by the public sector, both externally and domestically. Can the middle-income countries restore their pre-2008 macroeconomic space (to the level given by historical averages of key macroeconomic variables) or contain it from further deterioration in the medium term? In an endeavor to address this question, this paper shows, through illustrative scenarios, that the room to maneuver for some countries is somewhat limited unless they embark on severe, unprecedented fiscal adjustments or they may need more time to do so than current projections seem to suggest.
On the contingent value of dynamic capabilities for competitive advantage: The nonlinear moderating effect of environmental dynamism

This article suggests that dynamic capabilities can give the firm competitive advantage, but this effect is contingent on the level of dynamism of the firm's external environment. A nonlinear, inverse U-shaped moderation is proposed, implying that the relationship between dynamic capabilities and competitive advantage is strongest under intermediate levels of dynamism but comparatively weaker when dynamism is low or high. This proposition is tested using data on alliance management capability and new product development capability, two specific dynamic capabilities widely recognized in prior research. Results based on longitudinal key informant data from 279 firms support the account that these dynamic capabilities are more strongly associated with competitive advantage in moderately dynamic than in stable or highly dynamic environments.
Sharp MSE Bounds for Proximal Denoising

Denoising has to do with estimating a signal $$\mathbf {x}_0$$x0 from its noisy observations $$\mathbf {y}=\mathbf {x}_0+\mathbf {z}$$y=x0+z. In this paper, we focus on the "structured denoising problem," where the signal $$\mathbf {x}_0$$x0 possesses a certain structure and $$\mathbf {z}$$z has independent normally distributed entries with mean zero and variance $$\sigma ^2$$ź2. We employ a structure-inducing convex function $$f(\cdot )$$f(·) and solve $$\min _\mathbf {x}\{\frac{1}{2}\Vert \mathbf {y}-\mathbf {x}\Vert _2^2+\sigma {\lambda }f(\mathbf {x})\}$$minx{12źy-xź22+źźf(x)} to estimate $$\mathbf {x}_0$$x0, for some $$\lambda >0$$ź>0. Common choices for $$f(\cdot )$$f(·) include the $$\ell _1$$l1 norm for sparse vectors, the $$\ell _1-\ell _2$$l1-l2 norm for block-sparse signals and the nuclear norm for low-rank matrices. The metric we use to evaluate the performance of an estimate $$\mathbf {x}^*$$xź is the normalized mean-squared error $$\text {NMSE}(\sigma )=\frac{{\mathbb {E}}\Vert \mathbf {x}^*-\mathbf {x}_0\Vert _2^2}{\sigma ^2}$$NMSE(ź)=Eźxź-x0ź22ź2. We show that NMSE is maximized as $$\sigma \rightarrow 0$$źź0 and we find the exact worst-case NMSE, which has a simple geometric interpretation: the mean-squared distance of a standard normal vector to the $${\lambda }$$ź-scaled subdifferential $${\lambda }\partial f(\mathbf {x}_0)$$źźf(x0). When $${\lambda }$$ź is optimally tuned to minimize the worst-case NMSE, our results can be related to the constrained denoising problem $$\min _{f(\mathbf {x})\le f(\mathbf {x}_0)}\{\Vert \mathbf {y}-\mathbf {x}\Vert _2\}$$minf(x)≤f(x0){źy-xź2}. The paper also connects these results to the generalized LASSO problem, in which one solves $$\min _{f(\mathbf {x})\le f(\mathbf {x}_0)}\{\Vert \mathbf {y}-{\mathbf {A}}\mathbf {x}\Vert _2\}$$minf(x)≤f(x0){źy-Axź2} to estimate $$\mathbf {x}_0$$x0 from noisy linear observations $$\mathbf {y}={\mathbf {A}}\mathbf {x}_0+\mathbf {z}$$y=Ax0+z. We show that certain properties of the LASSO problem are closely related to the denoising problem. In particular, we characterize the normalized LASSO cost and show that it exhibits a "phase transition" as a function of number of observations. We also provide an order-optimal bound for the LASSO error in terms of the mean-squared distance. Our results are significant in two ways. First, we find a simple formula for the performance of a general convex estimator. Secondly, we establish a connection between the denoising and linear inverse problems.
The algebraic closure of the power series field in positive characteristic

For K an algebraically closed field, let K((t)) denote the quotient field of the power series ring over K. The “Newton-Puiseux theorem” states that if K has characteristic 0, the algebraic closure of K((t)) is the union of the fields K((t1/n)) over n ∈ N. We answer a question of Abhyankar by constructing an algebraic closure of K((t)) for any field K of positive characteristic explicitly in terms of certain generalized power series.
Knowledge, Productivity, and Innovation in Nigeria: Creating a New Economy

Harnessing knowledge for development is not a new concept. Knowledge has always been central to development and can mean the difference between poverty and wealth. The knowledge economy is not just about establishing high-tech industries and creating an innovative and entrepreneurial culture. Economic literature indicates that simply adopting existing technologies widely available in developed countries can dramatically boost productivity and economic growth. This paper highlights the knowledge economy (KE) issues that confront Nigeria and offers policy prescriptions that will allow the country to take advantage of the opportunities available in moving toward a knowledge-based economy. The Knowledge Assessment Methodology (KAM) developed by the World Bank considers four pillars: a) skills and education, b) business environment, c) information and communications infrastructure, and d) innovation system.
The efficiency of postal services in the age of market liberalization and the internet: Evidence from Central and Eastern Europe

Abstract The rise in electronic communications and the recent liberalization of the postal market in the European Union have put national postal-service providers in Central and Eastern Europe (CEE) under pressure to restructure and optimize their operations. The paper employs non-parametric methods to measure the relative technical and cost efficiency of CEE postal operators in terms of quantity-based and quality-based output indicators. The results indicate that inefficiency varies between 20% and 30%. Regression analysis attributes efficiency gains to increased competition, institutional reforms, less burdensome customs procedures, and population density, while use of electronic mail was negatively related to postal-service efficiency.
Networks that learn the precise timing of event sequences

Neuronal circuits can learn and replay firing patterns evoked by sequences of sensory stimuli. After training, a brief cue can trigger a spatiotemporal pattern of neural activity similar to that evoked by a learned stimulus sequence. Network models show that such sequence learning can occur through the shaping of feedforward excitatory connectivity via long term plasticity. Previous models describe how event order can be learned, but they typically do not explain how precise timing can be recalled. We propose a mechanism for learning both the order and precise timing of event sequences. In our recurrent network model, long term plasticity leads to the learning of the sequence, while short term facilitation enables temporally precise replay of events. Learned synaptic weights between populations determine the time necessary for one population to activate another. Long term plasticity adjusts these weights so that the trained event times are matched during playback. While we chose short term facilitation as a time-tracking process, we also demonstrate that other mechanisms, such as spike rate adaptation, can fulfill this role. We also analyze the impact of trial-to-trial variability, showing how observational errors as well as neuronal noise result in variability in learned event times. The dynamics of the playback process determines how stochasticity is inherited in learned sequence timings. Future experiments that characterize such variability can therefore shed light on the neural mechanisms of sequence learning.
The Construction of All-Carbon Quaternary Stereocenters by Use of Pd-Catalyzed Asymmetric Allylic Alkylation Reactions in Total Synthesis

All-carbon quaternary stereocenters have posed significant challenges in the synthesis of complex natural products. These important structural motifs have inspired the development of broadly applicable palladium-catalyzed asymmetric allylic alkylation reactions of unstabilized non-biased enolates for the synthesis of enantioenriched α-quaternary products. This microreview outlines key considerations in the application of palladium-catalyzed asymmetric allylic alkylation reactions and presents recent total syntheses of complex natural products that have employed these powerful transformations for the direct, catalytic, enantioselective construction of all-carbon quaternary stereocenters.
Saturn’s aurora observed by the Cassini camera at visible wavelengths

Abstract The first observations of Saturn’s visible-wavelength aurora were made by the Cassini camera. The aurora was observed between 2006 and 2013 in the northern and southern hemispheres. The color of the aurora changes from pink at a few hundred km above the horizon to purple at 1000–1500 km above the horizon. The spectrum observed in 9 filters spanning wavelengths from 250 nm to 1000 nm has a prominent H-alpha line and roughly agrees with laboratory simulated auroras. Auroras in both hemispheres vary dramatically with longitude. Auroras form bright arcs between 70° and 80° latitude north and between 65° and 80° latitude south, which sometimes spiral around the pole, and sometimes form double arcs. A large 10,000-km-scale longitudinal brightness structure persists for more than 100 h. This structure rotates approximately together with Saturn. On top of the large steady structure, the auroras brighten suddenly on the timescales of a few minutes. These brightenings repeat with a period of ∼1 h. Smaller, 1000-km-scale structures may move faster or lag behind Saturn’s rotation on timescales of tens of minutes. The persistence of nearly-corotating large bright longitudinal structure in the auroral oval seen in two movies spanning 8 and 11 rotations gives an estimate on the period of 10.65 ± 0.15 h for 2009 in the northern oval and 10.8 ± 0.1 h for 2012 in the southern oval. The 2009 north aurora period is close to the north branch of Saturn Kilometric Radiation (SKR) detected at that time.
Corporate power, American democracy, and the automobile industry

Acknowledgments Introduction 1. Studying power in America 2. The structure of the auto industry 3. Corporate political hegemony and its decline: 1916-66 4. The politics of compromise: 1967-78 5. The resurgence of corporate power: 1979-81 6. The triumph of corporate power: regulatory policy, 1981-8 7. The triumph of corporate power: trade policy, 1981-5 8. Interregnum: 1989-96 Conclusion: corporate power and American democracy Index.