cssi/SciSciGPT-SciSciNet huggingface dataset:
Search with Multilateral Bargaining

Wage determination plays a key role in labor market search models and recent evidence suggests workers' and firms' alternative employment opportunities matter. This paper develops the first search model that, to the best of my knowledge, incorporates multilateral bargaining between multiple firms and multiple workers. Despite superficially differing from the search literature in many dimensions, the framework developed nests much of it as special cases. The question of when decentralized markets deliver efficient levels of unemployment and vacancy creation is then reexamined. With multilateral bargaining too few vacancies are created unless firms have all the bargaining power (can make take-it-or-leave-it offers). However, vacancy creation is nonetheless approximately efficient in local labor markets where people are suitable for many positions and positions are suitable for many people. To the extent that this describes unskilled labor markets, any intervention to encourage vacancy creation might be better targeted elsewhere.
Price Volatility and Transmission in the Hog and Pork Markets

Farm, wholesale and retail price relationships for U.S. hogs are analyzed. Price transmission estimates indicate partial adjustment in each market category when price changes in any other market. This implies imperfect price transmission between the market levels. Tests of Granger no-causality show causality in hog and pork markets.
Remapping the Flow of Funds

The Flow of Funds Accounts are a crucial data source on credit market positions in the U.S. economy. In particular, they combine regulatory data from various sources to produce a consistent set of flow and stock tables in major credit market instruments by sector. There is also a detailed breakdown of the financial sector by type of institution. This is exactly the kind of data needed to understand how financial innovation changes the amount of borrowing and lending in the economy and reshapes the financial industry. The events of the last five years have underscored the importance of positions data to guide economic analysis.
The Transition from Exhaustible to Renewable or Inexhaustible Resources

Allow me to begin with some simple and rather obvious remarks on the nature of the transition problem from exhaustible to renewable or inexhaustible resource use. First, a shift in resource use means also a shift in technology, because in this age resources go together with technologies that process them and put them to use. Secondly, while I have used the word ‘exhaustible’, the term ‘depletion’ is a more suitable word, in that it suggests a more gradual process. The later stages of depletion will then whenever possible call forth a substitute resource that allows society to meet the same or a similar need to that met by the resource being depleted. Finally, I will follow the model of price as a regulator that will touch off the substitution, smoothly if the degree and rate of depletion are foreseen sufficiently in advance.
NEW DEVELOPMENTS IN PHOTOACOUSTICS

There have been several important new developments in the fields of photoacoustics and photoacoustic spectroscopy. Photoacoustic techniques are now being used in ferromagnetic and electron spin resonance experiments, and there have been rapid advances in Fourier-transform infrared photoacoustic spectroscopy. In addition, the calorimetric aspects of photoacoustics are now being extensively exploited for phase transition studies, and to perform thermal-wave imaging and microscopy.
Quantum algorithms for nearest-neighbor methods for supervised and unsupervised learning

We present quantum algorithms for performing nearest-neighbor learning and k-means clustering. At the core of our algorithms are fast and coherent quantum methods for computing the Euclidean distance both directly and via the inner product which we couple with methods for performing amplitude estimation that do not require measurement. We prove upper bounds on the number of queries to the input data required to compute such distances and find the nearest vector to a given test example. In the worst case, our quantum algorithms lead to polynomial reductions in query complexity relative to Monte Carlo algorithms. We also study the performance of our quantum nearest-neighbor algorithms on several real-world binary classification tasks and find that the classification accuracy is competitive with classical methods.
Passive Superconductor: A Viable Method of Controlling Magnetization Multipoles in the SSC Dipole

At injection, the magnetization of the superconductor produces the dominant field error in the SSC dipole magnets. The field generated by magnetization currents in the superconductor is rich in higher symmetric multipoles (normal sextupole, normal decapole, and so on). Pieces of passive superconductor properly located within the bore of the dipole magnet can cancel the higher multipoles generated by the SSC dipole coils. The multipoles generated by the passive superconductor (predominantly sextupole and decapole) are controlled by the angular and radial location of the superconductor, the volume of superconductor, and the size of the superconducting filaments within the passive conductor. This paper will present the tolerances on each of these factors. The paper will show that multipole correction using passive superconductor is in general immune to the effects of temperature and magnetization decay due to flux creep, provided that dipole superconductor and the passive correction superconductor are properly specified. When combined with a lumped correction system, the passive superconductor can be a viable alternative to continuous correction coils within the SSC dipoles.
Adoption of Cover Crops and Its Effect on Nitrogen Use by Farmers

With increasing environmental concerns, increasing population, changing tastes and preferences of consumers towards healthier foods, and with more food safety requirements, agronomic practices have changed gradually to provide not only food and fiber but also public goods and other beneficial services from agriculture. Cover cropping is one type of technology increasingly being adopted by producers of multifunctional agriculture. Cover crops provide a range of benefits, both private and public. In this paper we identify factors affecting farmers’ choice to adopt cover crops. We examine the impact on nitrogen use from adopting cover crops and the resultant decrease in input costs. Using a two-stage approach that incorporates endogeneity of adoption in nitrogen management, we conclude that farmers adopting cover crop technologies, that increase production efficiency, tend to decrease nitrogen fertilizer use by 4.75%, as hypothesized by Smith (2002).
Optimal Query Complexity for Estimating the Trace of a Matrix

Given an implicit n×n matrix A with oracle access x T A x for any x ∈ ℝ n , we study the query complexity of randomized algorithms for estimating the trace of the matrix. This problem has many applications in quantum physics, machine learning, and pattern matching. Two metrics are commonly used for evaluating the estimators: i) variance; ii) a high probability multiplicative-approximation guarantee. Almost all the known estimators are of the form \(\frac{1}{k}\sum_{i=1}^k x_i^T A x_i\) for x i ∈ ℝ n being i.i.d. for some special distribution. Our main results are summarized as follows: 1 We give an exact characterization of the minimum variance unbiased estimator in the broad class of linear nonadaptive estimators (which subsumes all the existing known estimators). 2 We also consider the query complexity lower bounds for any (possibly nonlinear and adaptive) estimators: 1 We show that any estimator requires Ω(1/e) queries to have a guarantee of variance at most e. 2 We show that any estimator requires \(\Omega(\frac{1}{\epsilon ^2}\log \frac{1}{\delta})\) to achieve a (1±e)-multiplicative approximation guarantee with probability at least 1 − δ. Both above lower bounds are asymptotically tight.
A Unified Theory of Firm Selection and Growth

This article develops an analytical framework to study firm and exporter growth and provides a dynamic foundation for a standard general equilibrium trade model. Firm-level growth is the result of idiosyncratic productivity improvements with a continuous arrival of new potential producers. A firm enters a market if it is profitable to incur the marginal cost to reach the first consumer and pays an increasing marketing cost to reach additional consumers. I calibrate the model using data on the cross section of firm sales and bilateral trade, as well as the rate of incumbent firm exit. The calibrated model predicts that a firm’s growth is inversely related to its initial size, and that the distribution of growth rates of small firms is heavily skewed to the right. These predictions are confirmed by looking at the growth of sales of U.S. firms and Brazilian exporters to the United States. I use this model to study the impact of cross-firm reallocations on economic activity and measured productivity. JEL Codes: F12, L11, M31, D92.
LOESS RECORDS | China

Alternating loess and paleosol units in central and eastern China record a long history of monsoon climate. Whereas dust deposition was most intense at times of strong cold, dry winter monsoon conditions, reddish soils formed during episodes when the warm, moist summer monsoon climate was strongest. The loess and soil strata are distinguished by their lithology, soil characteristics, and magnetic properties. They are dated using radiocarbon, luminescence, cosmogenic-isotope, and paleomagnetic methods, and grain-size data tuned to the marine isotope record. Loess units correlate with glaciations and stades; paleosols formed during interglaciations and interstades. Loess grain size decreases logarithmically across the Loess Plateau from NNE to SSE, implying that dust source areas lay in northwestern China. Chinese dust has been identified as far downwind as Japan, the Pacific Ocean, and possibly Greenland. During glaciations, the rate of dust deposition reached 0.35 mm year −1 in the central Loess Plateau, but was only a third as great during interglaciations. High-magnitude peaks in dust accumulation apparently correlate with North Atlantic ice-rafting (Heinrich) events. Reddish fine-grained deposits underlying the primary loess section are also eolian in origin, and indicate that the onset of loess accumulation began during the Miocene Epoch. Environmental effects associated with loess include landslides, widespread erosion, and several important endemic diseases.
Developing a Cancer-Specific Geriatric Assessment: A Feasibility Study

Background As the U.S. population ages, there is an emerging need to characterize the "functional age" of older patients with cancer to tailor treatment decisions and stratify outcomes based on factors other than chronologic age. The goals of the current study were to develop a brief, but comprehensive, primarily self-administered cancer-specific geriatric assessment measure and to determine its feasibility as measured by 1) the percentage of patients able to complete the measure on their own, 2) the length of time to complete, and 3) patient satisfaction with the measure. Methods The geriatric and oncology literature was reviewed to choose validated measures of geriatric assessment across the following domains: functional status, comorbidity, cognition, psychological status, social functioning and support, and nutritional status. Criteria applied to geriatric assessment measurements included reliability, validity, brevity, and ability to self-administer. The measure was administered to patients with breast carcinoma, lung carcinoma, colorectal carcinoma, or lymphoma who were fluent in English and receiving chemotherapy at Memorial Sloan-Kettering Cancer Center (New York, NY) or the University of Chicago (Chicago, IL). Results The instrument was completed by 43 patients (mean age, 74 yrs; range, 65-87 yrs). The majority had AJCC Stage IV disease (68%). The mean time to completion of the assessment was 27 minutes (range, 8-45 mins). Most patients were able to complete the self-administered portion of the assessment without assistance (78%) and were satisfied with the questionnaire length (90%). There was no association noted between age (P = 0.56) or educational level (P = 0.99) and the ability to complete the assessment without assistance. Conclusions In this cohort, this brief but comprehensive geriatric assessment could be completed by the majority of patients without assistance. Prospective trials of its generalizability, reliability, and validity are justified.
Evidence that Incremental Delta-Bar-Delta Is an Attribute-Efficient Linear Learner

The Winnow class of on-line linear learning algorithms [10, 11] was designed to be attribute-efficient. When learning with many irrelevant attributes, Winnow makes a number of errors that is only logarithmic in the number of total attributes, compared to the Perceptron algorithm, which makes a nearly linear number of errors. This paper presents data that argues that the Incremental Delta-Bar-Delta (IDBD) second-order gradient-descent algorithm [14] is attribute-efficient, performs similarly to Winnow on tasks with many irrelevant attributes, and also does better than Winnow on a task where Winnow does poorly. Preliminary analysis supports this empirical claim by showing that IDBD, like Winnow and other attribute-efficient algorithms, and unlike the Perceptron algorithm, has weights that can grow exponentially quickly. By virtue of its more flexible approach to weight updates, however, IDBD may be a more practically useful learning algorithm than Winnow.
Price-Induced Technical Progress in 80 years of U.S. Agriculture

This paper presents a theory of technical progress that interprets the price-induced conjecture of Hicks. It provides also an exhaustive set of comparative statics conditions that constitute the scaffolding for an empirical test of the theory. A crucial assumption is that entrepreneurs make decisions about techniques on the basis of expected information about prices and quantities. Another assumption is that these decisions are made in order to fulfill a profitability objective. The novelty of our approach is that expected relative prices enter the production function as shifter of the technology frontier. The consequence of this assumption is an expansion of the traditional Shephard lemma that is useful for identifying the portion of input quantities that has been determined by the conjecture of price-induced technical progress (PITP). The theory is applied to a sample of 80 years of US agriculture. Three versions of the general model are presented. The first version deals only with expected relative prices. The empirical results do not reject the PITP hypothesis. The second and third versions introduce lagged expected relative prices, lagged R&D expenditures and lagged extension expenditures as explanatory variables of the portion of the input quantities that may be attributable to technical progress.
Biography of Dr. Harvey Cushing.

To the Editor:— Mrs. Cushing has requested me to prepare a biography of her husband, and I should be most grateful to any one who wishes to make letters, anecdotes or other memorabilia available. Copies of all letters, no matter how brief, are desired, and if dates are omitted it is hoped that, when possible, these may be supplied (e. g., from the postmark). If original letters or other documents are submitted, they will be copied and returned promptly. A new medical library building is being erected at Yale University School of Medicine to receive Dr. Cushing's library and collections, including his letters, diaries and manuscripts. Any of his friends who wish, now or later, to present correspondence, photographs or other memorabilia for permanent preservation among the Cushing papers will receive the appreciative thanks of the university.
Parsing and hypergraphs

While symbolic parsers can be viewed as deduction systems, this view is less natural for probabilistic parsers. We present a view of parsing as directed hypergraph analysis, which naturally covers both symbolic and probabilistic parsing. We illustrate the approach by showing how a dynamic extension of Dijkstra's algorithm can be used to construct a probabilistic chart parser with an O(n3) time bound for arbitrary PCFGs, while preserving as much of the flexibility of symbolic chart parsers as is allowed by the inherent ordering of probabilistic dependencies.
Brazilian Exports : Climbing Down a Competitiveness Cliff

This note examines in detail Brazil’s export performance over the past 15 years, focusing not only on growth and composition, but also on different performance dimensions, including diversification, sophistication, and firm dynamics. The analysis uses international comparisons to better situate the Brazilian performance, and explores different databases, including firm-level data recently published by the World Bank. The note uses a recent diagnostic toolkit developed by the World Bank in order to suggest some hypotheses about the factors that have been inhibiting exports and industrial production expansion. Among the latter, it is noted how service sectors, as the largest beneficiaries from favorable terms of trade, accommodated larger wage increases and "exported" cost pressures to other sectors of the economy. Furthermore, although a stronger currency can be appointed as one of the elements behind the lower competitiveness in Brazilian exports, sluggish productivity performance and a real wage uptrend explain a significant part of the overall loss of competitiveness. This diagnostic reinforces the importance of resuming the agenda of microeconomic reforms, increasing the investment-to-gross domestic product ratio, and advancing toward better-skilled human capital.
Agglomeration, backward and forward linkages: evidence from South Korean investment in China

Abstract With a firm-level data set, we study the location decision of South Korean multinationals across China's regions. Our conditional logit estimates confirm agglomeration effects along industry and along national lines. We add an upstream and downstream (backward and forward) linkage effect. We find that the presence of upstream and downstream South Korean affiliates significantly increases the likelihood that a South Korean multinational invests in a particular region. However, linkages that do not differentiate by nationality do not seem to matter much. As such, our analysis of investors' location choice brings together two perspectives: linkages and agglomeration along national lines.
Communication-Minimal Partitioning of Parallel Loops and Data Arrays for Cache-Coherent Distributed-Memory Multiprocessors

Harnessing the full performance potential of cache-coherent distributed shared memory multiprocessors without inordinate user effort requires a compilation technology that can automatically manage multiple levels of memory hierarchy. This paper describes a working compiler for such machines that automatically partitions loops and data arrays to optimize locality of access.
Degenerate Pullback Attractors for the 3D Navier-Stokes Equations

As was found in Cheskidov and Kavlie (Pullback attractors for generalized evolutionary systems. DCDS-B 20(3), 749–779, 2015), the 3D Navier–Stokes equations with a translationally bounded force possesses pullback attractors \({\mathscr{A}_w(t)}\) in a weak sense. Moreover, those attractors consist of complete bounded trajectories. In this paper, we present a sufficient condition under which the pullback attractors are degenerate. That is, if the Grashof number is small enough, each section of the pullback attractor is a single point on a unique, complete, bounded, strong solution. We then apply our results to provide a new proof of the existence of a unique, strong, periodic solution to the 3D Navier–Stokes with a small, periodic forcing term.
On the many-to-one transport capacity of a dense wireless sensor network and the compressibility of its data

In this paper we investigate the capability of large-scale sensor networks to measure and transport a two-dimensional field. We consider a data-gathering wireless sensor network in which densely deployed sensors take periodic samples of the sensed field, and then scalar quantize, encode and transmit them to a single receiver/central controller where snapshot images of the sensed field are reconstructed. The quality of the reconstructed field is limited by the ability of the encoder to compress the data to a rate less than the single-receiver transport capacity of the network. Subject to a constraint on the quality of the reconstructed field, we are interested in how fast data can be collected (or equivalently how closely in time these snapshots can be taken) due to the limitation just mentioned. As the sensor density increases to infinity, more sensors send data to the central controller. However, the data is more correlated, and the encoder can do more compression. The question is: Can the encoder compress sufficiently to meet the limit imposed by the transport capacity? Alternatively, how long does it take to transport one snapshot? We show that as the density increases to infinity, the total number of bits required to attain a given quality also increases to infinity under any compression scheme. At the same time, the single-receiver transport capacity of the network remains constant as the density increases. We therefore conclude that for the given scenario, even though the correlation between sensor data increases as the density increases, any data compression scheme is insufficient to transport the required amount of data for the given quality. Equivalently, the amount of time it takes to transport one snapshot goes to infinity.
Recreation's Role in Rehabilitating Blind People

(1958). Recreation's Role in Rehabilitating Blind People. Journal of Health, Physical Education, Recreation: Vol. 29, No. 1, pp. 21-44.
The biosynthesis of trimethylamine-N-oxide.

Norris and Benoit (1) provided ‘good evidence that injected trimethylamine is converted in the rat to its N-oxide and excreted in the urine. Other mammals have been shown to have the ability to effect the same reaction (2, 3). In a preliminary communication (4), we have reported that hog liver microsomes will catalyze the oxidation of trimethylamine in vitro. The additional requirement for reduced triphosphopyridine nucleotide and oxygen makes this system analogous to a group of microsomal enzyme systems that also catalyze biological oxidations (5). Thus, a study of the oxidation of trimethylamine may yield information on microsomal oxidations in general. In this paper, evidence is presented that the product of trimethylamine oxidation is trimethylamine-N-oxide. Results of experiments to determine optimal conditions for this reaction and the effects of some potential inhibitors and activators are reported.
The full economic cost of groundwater extraction

When a groundwater basin is exploited by a large number of farmers, acting independently, each farmer has little incentive to practice conservation that would primarily benefit other farmers. This can lead to excessive groundwater extraction. When farmers pay less than the full cost of electricity used for groundwater pumping, this problem can be worsened; while the problem can be somewhat relieved by rationing the electricity supply. The research in this paper constructs an analytical framework for describing the characteristics of economically efficient groundwater management plans, identifying how individual water use decisions by farmers collectively depart from efficient resource use, and examining how policies related to both water and electricity can improve on the efficiency of the status quo. It is shown that an optimal scheme for pricing electricity used for pumping groundwater includes two main elements: 1) the full (marginal) economic cost of electricity must be covered; and 2) there must be an extra charge, reflected in the electricity price, corresponding to the externality cost of groundwater pumping. The analysis includes a methodology for calculating the latter externality cost, based on just a few parameters, and a discussion of how electricity pricing could be modified to improve efficiency in both power and water use.
Climate Change and Environmental Security: Bringing Realism Back In

In international relations theory literature, realist scholars maintain a traditional view of security based on fear and the attainment of survival through power maximization in an anarchic world, achieved exclusively through military prowess. Liberal scholars of international relations contend that the realist conception of security is unnecessarily limited, and call for the broadening of security to include concerns such as economic security, human security, and environmental security. However, is realism inherently incompatible with the concept of environmental security? I argue that by stretching the conceptual limits of realism it becomes possible to account for security concerns related to the environment and climate change. In this paper I seek to incorporate environmental security into the broader framework of realism by analyzing the extent to which environmental problems pose a threat to the survival of major states. I conclude by calling for the development of a grand conceptual approach to environmental security and more empirical research to be conducted on issues that exist at the nexus between security and the environment.
The Geography of Trade and Multinational Production

We introduce trade, multinational production (MP), and diffusion of ideas in a multicountry, Ricardian model that captures the strong positive correlation observed between trade and MP flows across countries. MP serves as a way for ideas to diffuse across countries when firms replicate their home technology by opening affiliates in foreign countries. Goods can be produced with three sets of ideas: national ideas specific to each country; MP ideas that started out being national and became available for MP, but remain specific to the country of origin; and global ideas that are available in any country. Firms in each country can either trade or do MP in each good. Both activities have country-pair specific “iceberg” costs. The model is flexible enough to incorporate “vertical” MP: firms from country n can serve consumers in country i by doing MP in a third country and export from there to the final destination. Further, we introduce explicitly complementarity between trade and MP: affiliate plants produce using a bundle of home and host country intermediate inputs where home inputs need to be imported. We estimate the model using data on trade and MP flows, for OECD(19). Our estimates suggest that the observed correlation between trade and MP across countries is mainly due to a strong correlation between trade and MP costs, and to a lesser extent to complementarities between home and host country inputs in MP. Accordingly, welfare calculations show that gains from openness are lower than the sum of gains from trade, MP, and diffusion, separately, suggesting that these flows are mainly substituting each other. ∗We benefited from comments of participants at the Annual Meeting of the Society for Economic Dynamics (2007), and the Annual Conference on Macro and Development at U. Pittsburgh (2007). †E-mail: nramondo@mail.utexas.edu ‡E-mail: andres@psu.edu
Optimal Interdiction of Unreactive Markovian Evaders

The interdiction problem arises in a variety of areas including military logistics, infectious disease control, and counter-terrorism. In the typical formulation of network interdiction, the task of the interdictor is to find a set of edges in a weighted network such that the removal of those edges would maximally increase the cost to an evader of traveling on a path through the network. Our work is motivated by cases in which the evader has incomplete information about the network or lacks planning time or computational power, e.g. when authorities set up roadblocks to catch bank robbers, the criminals do not know all the roadblock locations or the best path to use for their escape. We introduce a model of network interdiction in which the motion of one or more evaders is described by Markov processes and the evaders are assumed not to react to interdiction decisions. The interdiction objective is to find an edge set of size B , that maximizes the probability of capturing the evaders. We prove that similar to the standard least-cost formulation for deterministic motion this interdiction problem is also NP-hard. But unlike that problem our interdiction problem is submodular and the optimal solution can be approximated within 1 *** 1/e using a greedy algorithm. Additionally, we exploit submodularity through a priority evaluation strategy that eliminates the linear complexity scaling in the number of network edges and speeds up the solution by orders of magnitude. Taken together the results bring closer the goal of finding realistic solutions to the interdiction problem on global-scale networks.
Law and Religion: An Imaginary Conversation with a Medieval Jurist

Like ourselves, people in the medieval world took law seriously. They had great law schools, such as the one in Bologna, where professors expounded the Roman law of Justinian's Corpus iuris civilis. They regarded the rule of law as a model for the social order. They explained their political disputes in terms of constitutional questions and their personal quarrels in terms of rights violated. Without this heritage the modem world would be inconceivably different. They, however, lived in an Age of Faith while we live in a secular society. Surely, one would think, they must have thought about law quite differently than we do. It would be illuminating to travel back in time and speak with a medieval jurist. I have tried to imagine what that experience would be like. What follows is a report of a conversation between a modem student of law and legal history and a fourteenth-century Bolognese law professor. My rule in constructing it was to allow my medieval jurist to stray as little as possible from opinions actually expressed by prominent men of his age. His views on law reflect those of Bartolus and Baldus who wrote in his own century. His views on theology reflect those of Thomas Aquinas who wrote in the century before and with whose works Bartolus, Baldus, and other fourteenth-century jurists were familiar.
On Money as a Substitute for Perfect Recall

In environments with no commitment and with a need for intertemporal trade, bounded recall is shown to be a sufficient friction for a receipt system (fiat money) to lead to improved allocations in an otherwise frictionless Walrasian model. The absence of other frictions makes price determination tractable, thus the model may be used for quantitative monetary policy experiments. Some issues regarding the divisibility of money are also discussed.
Federal Crop and Crop Revenue Insurance Programs: Multiple Peril Crop Insurance (MPCI) and Catastrophic Coverage Policies

Decision Making Federal crop insurance against individual farm yield losses in the form of multiple peril policies has been available for some crops since 1938. Following the 1980 Federal Crop Insurance Act, the number of crops and the geographic coverage of the federal crop yield loss insurance program was greatly expanded. Beginning in the late 1980s, in addition to traditional multiple peril policies, new policies were developed based on yield losses at the county level and offered for a limited number of crops in a limited number of counties.
Facial reanimation by cross-facial nerve grafting: report of five cases.

Facial nerve repair is a dynamic reanimation technique. Direct nerve repair by suturing or grafting can provide good results within a specific time frame. Immediate nerve repair has been successful in cases of laceration injuries, but nerve grafting techniques are typically delayed when it is clear that direct suturing to the nerve trunk cannot be achieved without tension. Delayed nerve grafting is also employed following ablative procedures and in cases of trauma that cause segmental nerve deficits. Cross-facial nerve grafting is particularly useful when the peripheral branches are intact and the main trunk of the facial nerve is inaccessible. This method is also typically performed in a delayed fashion. Rehabilitation of the facial nerve and subsequent reinnervation of the mimetic motor endplates are achieved through axonal growth. In this article, we describe a consecutive series of five patients who developed facial paralysis following cranial surgery for acoustic neuroma. Each underwent successful cross-facial nerve grafting during the first week following their initial surgery. Each received a sural nerve graft to at least two main divisions of the VII th cranial nerve. We discuss our operative technique and the degree of restored nerve function.
Comparison of objective functions for estimating linear-nonlinear models

This paper compares a family of methods for characterizing neural feature selectivity with natural stimuli in the framework of the linear-nonlinear model. In this model, the neural firing rate is a nonlinear function of a small number of relevant stimulus components. The relevant stimulus dimensions can be found by maximizing one of the family of objective functions, Renyi divergences of different orders [1, 2]. We show that maximizing one of them, Renyi divergence of order 2, is equivalent to least-square fitting of the linear-nonlinear model to neural data. Next, we derive reconstruction errors in relevant dimensions found by maximizing Renyi divergences of arbitrary order in the asymptotic limit of large spike numbers. We find that the smallest errors are obtained with Renyi divergence of order 1, also known as Kullback-Leibler divergence. This corresponds to finding relevant dimensions by maximizing mutual information [2]. We numerically test how these optimization schemes perform in the regime of low signal-to-noise ratio (small number of spikes and increasing neural noise) for model visual neurons. We find that optimization schemes based on either least square fitting or information maximization perform well even when number of spikes is small. Information maximization provides slightly, but significantly, better reconstructions than least square fitting. This makes the problem of finding relevant dimensions, together with the problem of lossy compression [3], one of examples where information-theoretic measures are no more data limited than those derived from least squares.
Developments in the Karplus equation as they relate to the NMR coupling constants of carbohydrates.

Abstract The development of Karplus‐type formulas that relate the NMR coupling constants of carbohydrates and related ma olecules to the dihedral angle between the coupled nuclei is surveyed, including couplings over three, four, or five bonds. Most of the major types of coupling constants of interest in carbohydrate characterization are described, including several kinds of proton–proton couplings, those between protons and heteronuclei, and others involving two heteronuclei, over a number of different coupling pathways. The equations range from simple, two‐parameter versions that depict only the torsional dependence of coupling constants, to complex 22‐parameter forms that simulate the variation of the coupling with many different molecular properties. Methods for formulation of the Karplus relationships are discussed, including multidimensional NMR methods, molecular modeling, and theoretical computations that have been used either to support the experimental measurements, or as stand‐alone techniques for elucidation of molecular geometry, and the calculation of coupling constants for direct definition of the equations. Online calculator programs for coupling constants and torsion angles are described.
How does public information on central bank intervention strategies affect exchange rate volatility ? the case of Peru

Intervention operations in the foreign exchange market are used by the Banco Central de Reserva del Peru to manage both the level and volatility of their exchange rates. The Banco Central de Reserva del Peru provides information to the market about the specific hours of the day interventions would take place and the total amount of intervention. It consistently buys and sells on the foreign exchange market to avoid large appreciations and depreciations of the Peruvian nuevo sol against the U.S. dollar (Sol/USD), respectively. The estimates in this paper indicate that past information on interventions has moved the sol in the intended direction but only during the time the Banco Central de Reserva del Peru has announced it would be active in the foreign exchange market. The authors also find that the expectation of future interventions by the Banco Central de Reserva del Peru decreases the volatility of the sol when it intervenes to avoid an appreciation of the sol; however, the opposite occurs when the intervention takes place to defend the sol from depreciation. Indeed, the sol has been less volatile during periods when the Banco Central de Reserva del Peru has intervened than otherwise.
DNA-based Cryptography

Recent research has considered DNA as a medium for ultra-scale computation and for ultra-compact information storage. One potential key application is DNA-based, molecular cryptography systems. We present some procedures for DNA-based cryptography based on one-time-pads that are in principle unbreakable. Practical applications of cryptographic systems based on one-time-pads are limited in conventional electronic media by the size of the one-time-pad; however DNA provides a much more compact storage medium, and an extremely small amount of DNA suffices even for huge one-time-pads. We detail procedures for two DNA one-time-pad encryption schemes: (i) a substitution method using libraries of distinct pads, each of which defines a specific, randomly generated, pair-wise mapping; and (ii) an XOR scheme utilizing molecular computation and indexed, random key strings. These methods can be applied either for the encryption of natural DNA or for artificial DNA encoding binary data. In the latter case, we also present a novel use of chip-based DNA micro-array technology for 2D data input and output. Finally, we examine a class of DNA steganography systems, which secretly tag the input DNA and then hide it within collections of other DNA. We consider potential limitations of these steganographic techniques, proving that in theory the message hidden with such a method can be recovered by an adversary. We also discuss various modified DNA steganography methods which appear to have improved security.
The factored frontier algorithm for approximate inference in DBNs

The Factored Frontier (FF) algorithm is a simple approximate inference algorithm for Dynamic Bayesian Networks (DBNs). It is very similar to the fully factorized version of the Boyen-Koller (BK) algorithm, but instead of doing an exact update at every step followed by marginalisation (projection), it always works with factored distributions. Hence it can be applied to models for which the exact update step is intractable. We show that FF is equivalent to (one iteration of) loopy belief propagation (LBP) on the original DBN, and that BK is equivalent (to one iteration of) LBP on a DBN where we cluster some of the nodes. We then show empirically that by iterating more than once, LBP can improve on the accuracy of both FF and BK. We compare these algorithms on two real-world DBNs: the first is a model of a water treatment plant, and the second is a coupled HMM, used to model freeway traffic.
Turbulent Flow Analysis of Erosive Burning of Cylindrical Composite Solid Propellants

An axisymmetric turbulent boundary layer was analyzed in order to investigate erosive burning in composite solid-propellant rocket motors. It was found that there is a strong interaction between the core flow acceleration and turbulence level in the boundary layer. The increase of turbulence near the surface of the propellant plays an important role in the erosive burning mechanism. Reducing the port diameter makes a rocket motor more sensitive to erosive burning. When the port diameter is uniform, the erosive burning rate increases toward the aft end of the rocket motor. This trend is less pronounced or even reversed when the port diameter is divergent.
A Characterization of Deterministic Sampling Patterns for Low-Rank Matrix Completion

Low-rank matrix completion (LRMC) problems arise in a wide variety of applications. Previous theory mainly provides conditions for completion under missing-at-random samplings. This paper studies deterministic conditions for completion. An incomplete $d \times N$ matrix is finitely rank- $r$ completable if there are at most finitely many rank- $r$ matrices that agree with all its observed entries. Finite completability is the tipping point in LRMC, as a few additional samples of a finitely completable matrix guarantee its unique completability. The main contribution of this paper is a characterization of finitely completable observation sets. We use this characterization to derive sufficient deterministic sampling conditions for unique completability that can be efficiently verified. We also show that under uniform random sampling schemes, these conditions are satisfied with high probability if $\mathscr{O}(\max\{r,\log d\})$ entries per column are observed. These findings have several implications on LRMC regarding lower bounds, sample and computational complexity, the role of coherence, adaptive settings, and the validation of any completion algorithm. We complement our theoretical results with experiments that support our findings and motivate future analysis of uncharted sampling regimes.
On the D -module and formal-variable approaches to vertex algebras

In a program to formulate and develop two-dimensional conformal field theory in the framework of algebraic geometry, Beilinson and Drinfeld [BD] have recently given a notion of “chiral algebra” in terms of D-modules on algebraic curves. This definition consists of a “skew-symmetry” relation and a “Jacobi identity” relation in a categorical setting, and it leads to the operator product expansion for holomorphic quantum fields in the spirit of two-dimensional conformal field theory, as expressed in [BPZ], Because this operator product expansion, properly formulated, is known to be essentially a variant of the main axiom, the “Jacobi identity” [FLM], for vertex (operator) algebras ([Borc], [FLM]; see [FLM] for the proof), the chiral algebras of [BD] amount essentially to vertex algebras.
The performance of the perfluorocarbon liquid/plastic film capacitor technology in pulse power service — A current status report

At the 1982 CEIDP meeting, a paper by Mauldin, Nunnally, and Sarjeant was presented which described a program to evaluate the Sandia perfluorocarbon liquid/ plastic film capacitor technology in pulse power service [1].
Equivalence Classes of Permutations Modulo Replacements Between 123 and Two-Integer Patterns

We explore a new type of replacement of patterns in permutations, suggested by James Propp, that does not preserve the length of permutations. In particular, we focus on replacements between 123 and a pattern of two integer elements. We apply these replacements in the classical sense; that is, the elements being replaced need not be adjacent in position or value. Given each replacement, the set of all permutations is partitioned into equivalence classes consisting of permutations reachable from one another through a series of bi-directional replacements. We break the eighteen replacements of interest into four categories by the structure of their classes and fully characterize all of their classes.
Analysis of spurt phenomena for a non-newtonian fluid

Abstract : This document discusses novel phenomena in dynamic shearing flows of non-Newtonian fluids of importance for polymer processing. A striking example is spurt which was observed experimentally in the flow of monodispersive polyisoprenes through capillaries; the volumetric flow rate increased dramatically at a critical stress independent of molecular weight. The authors show that satisfactory explanation of spurt requires studying the full dynamics of the equations of motion and constitutive relations characterized by a non- monotonic relation between the steady shear stress and strain rate. The increase in volumetric flow rate is shown to correspond to jumps in the strain rate when the driving pressure gradient exceeds a critical value. Motivated by scaling suggested by accurate numerical computations of the governing dynamic problem that yielded qualitative and quantitative agreement with experiment, we introduce a system of ordinary differential equation that approximates dynamic behavior of highly elastic and very viscous fluids. The complete dynamics of the system of ode's determined by phase plane analysis. These results are then used to explain not only spurt but also shape memory, hysteresis, latency, and other effects that have also been observed in numerical simulations.
Resonant and Non-Resonant Wave-Wave Interactions for Internal Gravity Waves

The purpose of this study is to investigate the means by which energy is transferred among internal gravity waves. The transfer of energy in weakly interacting flows is characterized by resonant interactions in which the interaction time scale is much greater than the component wave periods. The energy transfers occurring in a more nonlinear system, where interaction time scales can be of the same order of the wave period, were practically untreated. In the present study, we will discuss the dynamics of waves in such a nonlinear regime.
Convergence of zeta functions of graphs

The L 2 -zeta function of an infinite graph Y (defined previously in a ball around zero) has an analytic extension. For a tower of finite graphs covered by Y, the normalized zeta functions of the finite graphs converge to the L 2 -zeta function of Y.
Round-Trip Voronoi Diagrams and Doubling Density in Geographic Networks

The round-trip distance function on a geographic network (such as a road network, flight network, or utility distribution grid) defines the "distance" from a single vertex to a pair of vertices as the minimum length tour visiting all three vertices and ending at the starting vertex. Given a geographic network and a subset of its vertices called "sites" (for example a road network with a list of grocery stores), a two-site round-trip Voronoi diagram labels each vertex in the network with the pair of sites that minimizes the round-trip distance from that vertex. Alternatively, given a geographic network and two sets of sites of different types (for example grocery stores and coffee shops), a two-color round-trip Voronoi diagram labels each vertex with the pair of sites of different types minimizing the round-trip distance. In this paper, we prove several new properties of two-site and two-color round-trip Voronoi diagrams in a geographic network, including a relationship between the "doubling density" of sites and an upper bound on the number of non-empty Voronoi regions. We show how those lemmas can be used in new algorithms asymptotically more efficient than previous known algorithms when the networks have reasonable distribution properties related to doubling density, and we provide experimental data suggesting that road networks with standard point-of-interest sites have these properties.
Slightly Bimetric Gravitation

The inclusion of a flat metric tensor in gravitation permits the formulation of a gravitational stress-energy tensor and the formal derivation of general relativity from a linear theory in flat spacetime. Building on the works of Kraichnan and Deser, we present such a derivation using universal coupling and gauge invariance.