cssi/SciSciGPT-SciSciNet huggingface dataset:
Steady-state properties of lock-on current filaments in GaAs

Collective impact ionization has been used to explain lock-on in semi-insulating GaAs under high-voltage bias. We have used this theory to study some of the steady-state properties of lock-on current filaments. In steady state, the heat gained from the field is exactly compensated by the cooling due to phonon scattering. In the simplest approximation, the carrier distribution approaches a quasi equilibrium Maxwell-Boltzmann distribution. In this report, we examine the validity of this approximation. We find that this approximation leads to a filament carrier density that is much lower than the high density needed to achieve a quasi-equilibrium distribution. Further work on this subject is in progress.
Reducing communication latency with path multiplexing in optically interconnected multiprocessor systems

Reducing communication latency, which is a performance bottleneck in optically interconnected multiprocessor systems, is of prominent importance. A conventional approach for establishing connections in multiplexed networks uses a set of independent time slots (or virtual channels) along a path for each connection. This approach requires the use of switching devices capable of interchanging time slots, and thus introduces latency in addition to hardware and control complexity. We propose an approach to all-optical time division multiplexed (TDM) communications in multiprocessor systems. The idea is to establish a connection along a path using a set of time slots (or virtual channels) that are dependent on each other, so that no time slot interchanging is required. We compare the proposed approach with the conventional one in terms of the overall communication latency. We found that, despite the possibility that establishing a connection may take a longer time, the proposed approach will result in lower overall communication latency as it eliminates the delays introduced by the time slot interchanging switching devices.
Ablation, Thermal Response, and Chemistry Program for Analysis of Thermal Protection Systems

In previous work, the authors documented the Multicomponent Ablation Thermochemistry (MAT) and the Fully Implicit Ablation and Thermal response (FIAT) programs. In this work, key features from MAT and FIAT were combined to create the new Fully Implicit Ablation, Thermal response, and Chemistry (FIATC) program. FIATC is fully compatible with FIAT (version 2.6) but has expanded capabilities to compute the multispecies surface chemistry and ablation rate as part of the surface energy balance. This new methodology eliminates B' tables, provides blown species as a function of time, and enables calculations that would otherwise be impractical (tables with 4 or more independent variables) or impossible (such as stacked pyrolyzing ablators). Equations and solution procedures are presented, then representative calculations of equilibrium and non-equilibrium ablation in flight and ground-test environments are discussed. Nomenclature
A performance metric for discrete-time chaos-based truly random number generators

In this paper, we develop an information entropy-based metric that represents the statistical quality of the generated binary sequence in truly random number generators (TRNG). The metric can be used for the design and optimization of the TRNG circuits as well as the development of efficient post-processing units for recovering the degraded statistical characteristics of the signal due to process variations.
The reciprocity conjecture of Khare and Wintenberger

We prove a strengthening of the “reciprocity conjecture” of Khare and Wintenberger. The input to the original conjecture is an odd prime p, a CM number field F containing the pth roots of unity, and a pair (q1, q2) of primes of the maximal totally real subfield F+ of F that are inert in the cyclotomic Zp-extension F + ∞/F +. In analogy to a statement about generalized Jacobians of curves, the conjecture asserts the equality of two procyclic subgroups of the Galois group of the maximal pro-p extension M of F+ ∞ that is unramified outside p and abelian over F+. The first is the intersection with Gal(M/F+ ∞) of the closed subgroup of Gal(M/F+) generated by the Frobenius elements of q1 and q2. The second is generated by the class of an exact sequence defining the minus part of the p-part of the ray class group of F∞ of conductor q1q2.
Top-down, scalable fabrication of high purity fluorescent nanodiamonds

We demonstrate a fabrication technique for high volume production of high-quality nanocrystals from bulk chemical vapor deposition diamond. Ramsey and Spin-Echo measurements confirm the long spin coherence of nitrogen vacancy centers in these nanocrystals.
Hall resistive tearing mode: A variational formulation

A unified linear tearing-mode formulation is given incorporating both resistivity and Hall effects. A variational method is used that appears to be best suited to deal with the difficulties peculiar to the triple-deck structure associated with the Hall resistive tearing mode but also to lead to a convenient analytical dispersion relation for the Hall resisitive tearing mode. This analytical dispersion relation: a) recovers the Furth-Killeen-Rosenbluth (Phys. Fluids, 6 (1963) 459) result for the resistive branch; b) gives a growth rate for the Hall branch which appears to be consistent with the growth rate of the electron-inertia–driven tearing mode given previously (Coppi B., Phys. Lett. A, 11 (1964) 226); c) recovers the scaling relation for the transition from the resisitive regime to the Hall regime numerically established by Fitzpatrick (Phys. Plasmas, 11 (2004) 937) in a driven Hall resistive reconnection situation.
Gold(I)‐Catalyzed Enantioselective Desymmetrization of 1,3‐Diols through Intramolecular Hydroalkoxylation of Allenes

A gold(I)-catalyzed enantioselective desymmetrization of 1,3-diols was achieved by intramolecular hydroalkoxylation of allenes. The catalyst system 3-F-dppe(AuCl)2/(R)-C8-TRIPAg proved to be specifically efficient to promote the desymmetrizing cyclization of 2-aryl-1,3-diols, which have proven challenging substrates in previous reports. Multisubstituted tetrahydrofurans were prepared in good yield with good enantioselectivity and diastereoselectivity by this method.
Climate, conflict, and social stability: what does the evidence say?

Are violent conflict and socio-political stability associated with changes in climatological variables? We examine 50 rigorous quantitative studies on this question and find consistent support for a causal association between climatological changes and various conflict outcomes, at spatial scales ranging from individual buildings to the entire globe and at temporal scales ranging from an anomalous hour to an anomalous millennium. Multiple mechanisms that could explain this association have been proposed and are sometimes supported by findings, but the literature is currently unable to decisively exclude any proposed pathway. Several mechanisms likely contribute to the outcomes that we observe.
Non-robust dynamic inferences from macroeconometric models: Bifurcation stratification of confidence regions

Abstract Grandmont [J.M. Grandmont, On endogenous competitive business cycles, Econometrica 53 (1985) 995–1045] found that the parameter space of the most classical dynamic models is stratified into an infinite number of subsets supporting an infinite number of different kinds of dynamics, from monotonic stability at one extreme to chaos at the other extreme, and with many forms of multiperiodic dynamics in between. The econometric implications of Grandmont’s findings are particularly important, if bifurcation boundaries cross the confidence regions surrounding parameter estimates in policy-relevant models. Stratification of a confidence region into bifurcated subsets seriously damages robustness of dynamical inferences. Recently, interest in policy in some circles has moved to New-Keynesian models. As a result, in this paper we explore bifurcation within the class of New-Keynesian models. We develop the econometric theory needed to locate bifurcation boundaries in log-linearized New-Keynesian models with Taylor policy rules or inflation-targeting policy rules. Central results needed in this research are our theorems on the existence and location of Hopf bifurcation boundaries in each of the cases that we consider.
Efficient robust private set intersection

Computing set intersection privately and efficiently between two mutually mistrusting parties is an important basic procedure in the area of private data mining. Assuring robustness, namely, coping with potentially arbitrarily misbehaving (i.e., malicious) parties, while retaining protocol efficiency (rather than employing costly generic techniques) is an open problem. In this work, the first solution to this problem is presented.
Organocatalyzed Asymmetric Conjugate Addition of Heteroaryl and Aryl Trifluoroborates: a Synthetic Strategy for Discoipyrrole D

Bis-heteroaryl or bis-aryl stereocenters were formed by an organocatalytic enantioselective conjugate addition using the respective trifluoroborate salts as nucleophiles. Control studies suggested that fluoride dissociation is necessary in the anhydrous conditions. This strategy is applicable to the synthesis of discoipyrrole D, an inhibitor of BR5 fibroblast migration.
Finite size corrections in two dimensional gauge theories and a quantitative chiral test of the overlap

Abstract An argument is presented for a certain universality of finite size corrections in two dimensional gauge theories. In the abelian case a direct calculation is carried out for a particular chiral model. The analytical result confirms the above universality and that the 't Hooft vertex previously measured using the overlap smoothly approaches the correct continuum limit within statistical errors.
Stereo-Active Lone-Pair Control on the Ferromagnetic Behavior in VO(SeO2OH)2: A New Acentric Ferromagnetic Material

A new acentric ferromagnetic material, VO(SeO2OH)2, has been synthesized and characterized by single crystal X-ray diffraction, second harmonic generation (SHG), and magnetization measurements. The crystal structure of VO(SeO2OH)2 consists of linear chains of corner-shared V4+O6 octahedra that are connected by SeO2OH groups. The material exhibits a weak SHG efficiency, comparable to α-SiO2, and a ferromagnetic transition (TC) at ∼2.5 K with a saturated magnetic moment of 1.09 μB per formula unit (μB/FU). The origin of the ferromagnetism is explained by the suppression of the antiferromagnetic superexchange (SE) and supersuper-exchange (SSE) interactions in the intra-chain and inter-chain magnetic interactions, respectively. In addition, using first principles density functional theory (DFT) calculations, we show that the SSE interactions depend on the O(2)−Se4+−O(3) angle. As we demonstrate, the stereoactive lone-pair on Se4+ is the driving force for the inter-chain ferromagnetic interactions.
A Reduction Technique for Prime Implicant Tables

Solving prime implicant tables is greatly facilitated by reduction techniques such as row dominance, column dominance, and essential row selection. This paper presents a new reduction technique which is operable on any otherwise irreducible table having a column covered by exactly two rows.
Cluster analysis of multiple planetary flow regimes

A modified cluster analysis method was developed to identify spatial patterns of planetary flow regimes, and to study transitions between them. This method was applied first to a simple deterministic model and second to Northern Hemisphere (NH) 500 mb data. The dynamical model is governed by the fully-nonlinear, equivalent-barotropic vorticity equation on the sphere. Clusters of point in the model's phase space are associated with either a few persistent or with many transient events. Two stationary clusters have patterns similar to unstable stationary model solutions, zonal, or blocked. Transient clusters of wave trains serve as way stations between the stationary ones. For the NH data, cluster analysis was performed in the subspace of the first seven empirical orthogonal functions (EOFs). Stationary clusters are found in the low-frequency band of more than 10 days, and transient clusters in the bandpass frequency window between 2.5 and 6 days. In the low-frequency band three pairs of clusters determine, respectively, EOFs 1, 2, and 3. They exhibit well-known regional features, such as blocking, the Pacific/North American (PNA) pattern and wave trains. Both model and low-pass data show strong bimodality. Clusters in the bandpass window show wave-train patterns in the two jet exit regions. They are related, as in the model, to transitions between stationary clusters.
Structural Ritz-Based Simple-Polynomial Nonlinear Equivalent Plate Approach - An Assessment

Thelinearequivalentplateapproachdevelopedandusedfortheaeroelasticoptimizationofcompositewingsatthe conceptual design stage is a Ritz approach based on simple polynomial functions as generalized coordinates. Generalization to the case of geometrically nonlinear structural behavior is presented here in an effort to assess accuracy and performance of the method in the nonlinear static and linear dynamic cases. Using the von Karman plate formulation for moderately large deformations, three-dimensional assemblies of thin-plate segments are modeled using a penalty function approach to impose boundary conditions and compatibility of motion between adjacent segments. Closed-form expressions for mass and stiffness terms (linear and nonlinear) make numerical integration unnecessary. Numerical results obtained by the present method for a variety of plate structures, in both static anddynamic cases, show good correlation with published results andresults by othercomputer codes.Results by the present formulation are also compared with large-deformation results. Limits of applicability, in terms of the range of deformations still captured accurately by the equivalent plate method, are studied in all test cases.
The Non-Monotonicity of Solutions in Swirling Flow.

Abstract : The existence of solutions of Batchelor's nonlinear differential equations for swirling flow induced by two parallel rotating coaxial discs of infinite size is investigated. It is found that if the discs rotate in the same direction (with one rotating and one stationary disc as a special case), then for sufficiently small kinematic viscosity of the fluid, the angular velocity of the swirling flow cannot vary monotonically in the axial direction. Should a condition of monotonic variation of the angular velocity be imposed, then a solution to the governing differential equations would not exist. A detailed step by step proof is provided.
An entropy-coded lattice vector quantizer for transform and subband image coding

A lattice-based vector quantizer (VQ) and noiseless code are proposed for transform and subband image coding. The quantization is simple to implement, and no vector codebooks need to be stored. The noiseless code enumerates lattice codevectors based on their (weighted) l/sub 1/ norm. A software implementation is able to handle lattice codebooks of size 2/sup 256/. The image coding performance is shown to be comparable or superior to the best encoding methods reported in the literature.
Optimal coordinated planning amongst self-interested agents with private state

Consider a multi-agent system in a dynamic and uncertain environment. Each agent's local decision problem is modeled as a Markov decision process (MDP) and agents must coordinate on a joint action in each period, which provides a reward to each agent and causes local state transitions. A social planner knows the model of every agent's MDP and wants to implement the optimal joint policy, but agents are self-interested and have private local state. We provide an incentive-compatible mechanism for eliciting state information that achieves the optimal joint plan in a Markov perfect equilibrium of the induced stochastic game. In the special case in which local problems are Markov chains and agents compete to take a single action in each period, we leverage Gittins allocation indices to provide an efficient factored algorithm and distribute computation of the optimal policy among the agents. Distributed, optimal coordinated learning in a multi-agent variant of the multi-armed bandit problem is obtained as a special case.
Supporting search for reusable software objects

Prior research has shown that achieving high levels of software reuse in the presence of repository and object-based computer-aided software engineering (CASE) development methods presents interesting human, managerial and technical challenges. This article presents research that seeks to enhanced software development performance through reuse. We propose automated support for developers who search large repositories for the appropriate reusable software objects. We characterize search for repository objects in terms of a multistage model involving screening, identification, and the subsequent choice between new object construction or reusable object implementation. We propose automated support tools, including ORCA, a software Object Reuse Classification Analyzer, and AMHYRST, an Automated HYpertext-based Reuse Search Tool, that are based on this model. ORCA utilizes a faceted classification approach that can be implemented using hypertext. We also describe an aspect of AMHYRST's architecture which can automatically create hypertext networks that represent and link objects in terms of a number of distinguishing features. We illustrate our approach with an example drawn from a real world object repository.
Anticipatory and implementation effects of FIN 46 on the behavior of different market participants

We examine whether Financial Accounting Standards Board (FASB)-mandated modifications of the consolidation rules (FIN 46 and FIN 46R) resulted in perceptible changes in market participants’ decisions as manifested in a variety of financial indicia. We find that financial analysts’ idiosyncratic precision of information decreased and equity market participants acted as if they perceived higher information risk, as evidenced by reduced earnings response coefficients, in anticipation of guidance. We attribute these effects to a perceived increase in information risk and decrease in accounting information quality. We find that the actual implementation of the new rules reversed some, but not all, of these effects. On the other hand, we find that information users that likely had access to information regarding the off-balance-sheet debt structures prior to 2001 did not exhibit a similar reaction to the apparent change in information risk either in anticipation or upon implementation of the new guidance. Speci...
Covalent Linkage of Distinct Substrate Degrons Controls Assembly and Disassembly of DegP Proteolytic Cages

Protein quality control requires careful regulation of intracellular proteolysis. For DegP, a periplasmic protease, substrates promote assembly of inactive hexamers into proteolytically active cages with 12, 18, 24, or 30 subunits. Here, we show that sensitive activation and cage assembly require covalent linkage of distinct substrate sequences that affect degradation (degrons). One degron binds the DegP active site, and another degron binds a separate tethering site in PDZ1 in the crystal structure of a substrate-bound DegP dodecamer. FRET experiments demonstrate that active cages assemble rapidly in a reaction that is positively cooperative in substrate concentration, remain stably assembled while uncleaved substrate is present, and dissociate once degradation is complete. Thus, the energy of binding of linked substrate degrons drives assembly of the proteolytic machine responsible for subsequent degradation. Substrate cleavage and depletion results in disassembly, ensuring that DegP is proteolytically active only when sufficient quantities of protein substrates are present.
Reflection and Ducting of Gravity Waves Inside the Sun

Internal gravity waves excited by overshoot at the bottom of the convection zone can be influenced by rotation and by the strong toroidal magnetic field that is likely to be present in the solar tachocline. Using a simple Cartesian model, we show how waves with a vertical component of propagation can be reflected when traveling through a layer containing a horizontal magnetic field with a strength that varies with depth. This interaction can prevent a portion of the downward traveling wave energy flux from reaching the deep solar interior. If a highly reflecting magnetized layer is located some distance below the convection zone base, a duct or wave guide can be set up, wherein vertical propagation is restricted by successive reflections at the upper and lower boundaries. The presence of both upward and downward traveling disturbances inside the duct leads to the existence of a set of horizontally propagating modes that have significantly enhanced amplitudes. We point out that the helical structure of these waves makes them capable of generating an α-effect, and briefly consider the possibility that propagation in a shear of sufficient strength could lead to instability, the result of wave growth due to over-reflection.
Relationship of anesthesia to postoperative personality changes in children

SOME POSSIBLE deleterious effects of hospitalization and surgical operations on the personalities of children have been described.1However, apparently there has been no attempt to relate the experiences of the induction period of anesthesia to the development of undesirable personality changes afterward. It is difficult to establish precise relationships, because the experiences of hospitalization, anesthetization, and operation are not easily separated. A recent study of the effect preanesthetic medication has upon the course of anesthesia2has led to an investigation of possible relationship between anesthesia and personality changes. Over an 18-month period, questionnaires were mailed to the parents of all children admitted to the Hospital of the University of Pennsylvania for an otolaryngological operation. Answers were sought to the following questions: 1. Is your child a bed-wetter; since operation does he wet the bed or wet it more frequently? 2. Does your child have night cries or terrors;
A 1.4 V Supply CMOS Fractional Bandgap Reference

This paper describes a bandgap reference that outputs a fraction of the silicon bandgap voltage. To simplify the design of an internal operational amplifier, the reference drives the base voltages on substrate transistors through unity-gain buffers to a fraction of a diode drop. With a 1.4 V supply, the reference produces an output of about 858 mV, which varies by 1.28 mV from -20degC to 100degC. It dissipates 162 muW and occupies 1.2 mm2 in 0.35 mum CMOS.
Heartbeat-Driven Medium-Access Control for Body Sensor Networks

In this paper, a novel time division multiple access based MAC protocol designed for body sensor networks (BSNs) is presented. H-medium-access control (MAC) aims to improve BSNs energy efficiency by exploiting heartbeat rhythm information, instead of using periodic synchronization beacons, to perform time synchronization. Heartbeat rhythm is inherent in every human body and observable in various biosignals. Biosensors in a BSN can extract the heartbeat rhythm from their own sensory data by detecting waveform peaks. All rhythms represented by peak sequences are naturally synchronized since they are driven by the same source, i.e., the heartbeat. Following the rhythm, biosensors can achieve time synchronization without having to turn on their radio to receive periodic timing information from a central controller, so that energy cost for time synchronization can be completely eliminated and the lifetime of the network can be prolonged. An active synchronization recovery scheme is also developed, including two resynchronization approaches. The algorithms are simulated using the discrete event simulator OMNet ++ with real-world data from the Massachusetts Institute of Technology-Boston's Beth Israel Hospital multiparameter database Multiparameter Intelligent Monitoring for Intensive Care. The results show that H-MAC can prolong the network life dramatically.
Joint Optimization of Hybrid Energy Storage and Generation Capacity With Renewable Energy

In an isolated power grid or a micro-grid with a small carbon footprint, the penetration of renewable energy is usually high. In such power grids, energy storage is important to guarantee an uninterrupted and stable power supply for end users. Different types of energy storage have different characteristics, including their round-trip efficiency, power and energy rating, self-discharge, and investment and maintenance costs. In addition, the load characteristics and availability of different types of renewable energy sources vary in different geographic regions and at different times of year. Therefore joint capacity optimization for multiple types of energy storage and generation is important when designing this type of power systems. In this paper, we formulate a cost minimization problem for storage and generation planning, considering both the initial investment cost and operational/maintenance cost, and propose a distributed optimization framework to overcome the difficulty brought about by the large size of the optimization problem. The results will help in making decisions on energy storage and generation capacity planning in future decentralized power grids with high renewable penetrations.
Implementation of a lag-lead compensator for robots

A frequency response approach was used to design and realize a lag-lead compensator for a robot arm. An analytical comparison between a PD (proportional-derivative) or PID (proportional integral-derivative) controller and a lag-lead compensator shows that the latter reduces the tradeoffs between the static accuracy, system stability, and is insensitive to disturbances in the frequency domain. The implementation and test results verify the encouraging results in the time domain. The lag-lead compensator reduces the tracking errors considerably. >
Developing countries changing participation in world trade

Recent year have seen substantial reductions in trade policy and other barriers inhibiting developing country participation in world trade. Lower barriers have contributed to a dramatic shift in the pattern of developing country trade-away from dependence on commodity exports to much greater reliance on manufacture and services. In addition, exports to other developing countries have become much more important. These changes have profound implications for the role played by developing countered in the world economy and trade system.
A fast algorithm for constructing sparse euclidean spanners

Let G = (V,E) be a n-vertex connected graph with positive edge weights, and let t > 1 be a real constant. A subgraph G' is a t-spanner if for all u,v ∊ V, the weight of the shortest path between u and v in G' is at most t times the weight of the corresponding shortest path in G. We design an O(n log2 n) time algorithm which, given a set V of n points in k-dimensional space (for any fixed k), and any real constant t > 1, produces a t-spanner of the complete Euclidean graph of V. This algorithm retains the spirit of a recent O(n3logn) time greedy algorithm which produces t-spanners; we use graph clustering techniques to achieve a more efficient implementation. Our spanners have O(n) edges and weight O(1)· wt(MST), which is similar to the size and weight of spanners constructed by the greedy algorithm. The constants implicit in the O-notation depend upon t and k.
Multiple peptide synthesis using a single support (MPS3)

An automated multiple peptide synthesis method to synthesize, cleave, and purify several peptides simultaneously in a single batch has been developed. The technique is based on the synthesis of multiple peptides on a single solid phase support and is easily adapted to manual or to automated methods. The approach relies on coupling of amino acid mixtures to the resin and it has been found that DCC/HOBt gives the best coupling performance. Fast Atom Bombardment Mass Spectrometry (FAB-MS) was used to rapidly and efficiently identify the peptides in each synthetic mixture which significantly assisted the purification process by HPLC. The method has been successfully applied to the synthesis of magainin 2 and angiotensinogen peptides.
Hepatocyte-Specific Expression of Human Lysosome Acid Lipase Corrects Liver Inflammation and Tumor Metastasis in lal-/- Mice

The liver is a major organ for lipid synthesis and metabolism. Deficiency of lysosomal acid lipase (LAL; official name Lipa, encoded by Lipa) in mice (lal−/−) results in enlarged liver size due to neutral lipid storage in hepatocytes and Kupffer cells. To test the functional role of LAL in hepatocyte, hepatocyte-specific expression of human LAL (hLAL) in lal−/− mice was established by cross-breeding of liver-activated promoter (LAP)–driven tTA transgene and (tetO)7-CMV-hLAL transgene with lal−/− knockout (KO) (LAP-Tg/KO) triple mice. Hepatocyte-specific expression of hLAL in LAP-Tg/KO triple mice reduced the liver size to the normal level by decreasing lipid storage in both hepatocytes and Kupffer cells. hLAL expression reduced tumor-promoting myeloid-derived suppressive cells in the liver of lal−/− mice. As a result, B16 melanoma metastasis to the liver was almost completely blocked. Expression and secretion of multiple tumor-promoting cytokines or chemokines in the liver were also significantly reduced. Because hLAL is a secretory protein, lal−/− phenotypes in other compartments (eg, blood, spleen, and lung) also ameliorated, including systemic reduction of myeloid-derived suppressive cells, an increase in CD4+ and CD8+ T and B lymphocytes, and reduced B16 melanoma metastasis in the lung. These results support a concept that LAL in hepatocytes is a critical metabolic enzyme in controlling neutral lipid metabolism, liver homeostasis, immune response, and tumor metastasis.
THERMAL PROCESSES GOVERNING HOT-JUPITER RADII

There have been many proposed explanations for the larger-than-expected radii of some transiting hot Jupiters, including either stellar or orbital energy deposition deep in the atmosphere or deep in the interior. In this paper, we explore the important influences on hot-Jupiter radius evolution of (i) additional heat sources in the high atmosphere, the deep atmosphere, and deep in the convective interior; (ii) consistent cooling of the deep interior through the planetary dayside, nightside, and poles; (iii) the degree of heat redistribution to the nightside; and (iv) the presence of an upper atmosphere absorber inferred to produce anomalously hot upper atmospheres and inversions in some close-in giant planets. In particular, we compare the radius expansion effects of atmospheric and deep-interior heating at the same power levels and derive the power required to achieve a given radius increase when night-side cooling is incorporated. We find that models that include consistent day/night cooling are more similar to isotropically irradiated models when there is more heat redistributed from the dayside to the nightside. In addition, we consider the efficacy of ohmic heating in the atmosphereand/or convective interior in inflating hot Jupiters. Among our conclusions are that (i) the most highly irradiated planets cannot stably have uB & 10 km s −1 · Gauss over a large fraction of their daysides, where u is the zonal wind speed and B is the dipolar magnetic field strength in the atmosphere, and (ii) that ohmic heating cannot in and of itself lead to a runaway in planet radius. Subject headings: planetary systems – radiative transfer
The Yangian symmetry of the Hubbard model

Abstract We have found a new hidden symmetry of the one-dimensional Hubbard model. We show that the one-dimensional Hubbard model on an infinite chain has an infinite-dimensional algebra of symmetries. This algebra is a direct sum of two sl(2)-Yangians. This Y(sl(2))⊕Y(sl(2)) symmetry is an extension of the well-known sl(2)⊕sl(2) one. The deformation parameters of the Yangians are proportional to the coupling constant of the Hubbard model Hamiltonian.
Fluorescent DNA-based enzyme sensors

Fluorescent sensors that make use of DNA structures have become widely useful in monitoring enzymatic activities. Early studies focused primarily on enzymes that naturally use DNA or RNA as the substrate. However, recent advances in molecular design have enabled the development of nucleic acid sensors for a wider range of functions, including enzymes that do not normally bind DNA or RNA. Nucleic acid sensors present some potential advantages over classical small-molecule sensors, including water solubility and ease of synthesis. An overview of the multiple strategies under recent development is presented in this critical review, and expected future developments in microarrays, single molecule analysis, and in vivo sensing are discussed (160 references).
Stereoselective Synthesis of Tertiary Ethers through Geometric Control of Highly Substituted Oxocarbenium Ions

Oxocarbenium ions are intermediates in a number of synthetic processes including Prins cyclizations,[1] acid-mediated additions to acetals,[2] allyl group transfers,[3] and additions of carbonyls to electrophiles.[4] Stereocontrol in these transformations can be quite high as a result of the strong preference, calculated at approximately 2 kcalmol−1,[5] for monosubstituted oxocarbenium ions to exist in E configurations. However, reports of geometric control for 1,1-disubstituted oxocarbenium ions are rare[6] because the steric difference between the alkyl groups is generally smaller than the steric difference between an alkyl group and a hydrogen atom. General models that predict the geometry of disubstituted oxocarbenium ions would be valuable for designing syntheses of natural products or natural-product-like libraries[7] that contain tertiary ether groups. Recently, our research group reported[8] that intramolecular nucleophilic additions to alkynyl-substituted oxocarbenium ions proceed with minimal stereocontrol to provide cis- and trans-2,6-disubstituted tetrahydropyrans. This unusual lack of stereo-control results from the approximate energetic equivalence of the E and Z oxocarbenium ions, which is a result of the small steric difference between an alkynyl group and a hydrogen atom (Scheme 1). Herein, we describe a rare application of carbon–hydrogen bond functionalization for stereoselective syntheses of molecules that contain fully substituted carbon atoms. The approach is based on the development of a model that is able to predict the geometries of 1,1-disubstituted oxocarbenium ions involved in nucleophilic additions that form tertiary ethers with high stereocontrol. We also report a model that illustrates stereocontrol in intramolecular additions to monosubstituted oxocarbenium ions relative to a tertiary ether.
Evaluation of subsidiary marketing performance: combining process and outcome performance metrics

Issues in evaluating marketing performance and devising appropriate metrics for measurement have taken center stage in marketing thought and practice in recent years. We propose an empirical model that enables a multinational enterprise (MNE) to assess the marketing performance of its subsidiaries, taking into explicit consideration the fact that tactical actions by subsidiaries contribute to the creation of assets that can be harnessed for marketing outcomes. Thus, our model captures the asset creation abilities of marketing expenditures and also takes in to account the environmental differences of the context in which each MNE subsidiary operates. We evaluate comparative, overall, and process-level (creation of market assets and market yield) marketing performance in the context of multi-country operations. This simultaneous examination of marketing process and marketing outcome performance enables a global corporation to gain strategic, operational, and diagnostic insights into the performance of its subsidiaries. Our approach is empirically illustrated with an evaluation of the marketing performance of subsidiaries of a large global corporation.
Earnings Quality Following Corporate Acquisitions

Purpose – The paper aims to examine earnings quality during the post‐acquisition period.Design/methodology/approach – The paper defines earnings quality as an earnings stream more closely associated with future cash flows from operations. It uses the stock market's reaction at the acquisition announcement to infer merger motives and hypothesize that synergy‐motivated acquisitions will produce higher quality earnings than agency‐motivated acquisitions.Findings – The paper finds that synergy‐motivated acquisitions produce higher quality earnings than agency‐motivated acquisitions.Research limitations/implications (if applicable) – The findings are consistent with this prediction and support the view that managers who pursue synergy or agency‐motivated acquisitions do not face the same economic environment and incentive schemes. The results are also consistent with the notion that incentives for earnings management are greater following agency‐motivated acquisitions when compared to those of synergy‐motivate...
Asymmetric hydroboration and Matteson homologation for the preparation of fluorinated α-phenethanols

Abstract The asymmetric catalytic hydroboration–oxidation of ring-fluorinated styrenes (F-PhCH CH2) was achieved with catecholborane along with a combination of [Rh(COD)2]+BF4− and (R)-BINAP providing 81–96% enantioselectivities for the product alcohols for ortho-unhindered styrenes. A deleterious effect of a 2,6-disubstitution on the enantioselectivity of the product alcohol was observed. 2-Trifluoromethylstyrene also provides only 53% ee, probably due to the steric bulk of the CF3 group at the ortho-position of styrene. Asymmetric homologation of fluorophenylmetals (magnesium bromide or lithium) with pinanediol α-chloroethylboronate, followed by oxidation readily furnished the desired 1-(2,6-difluorophenyl)- and 1-(perfluorophenyl)ethanols in 94–95% ee.
Cofree compositions of coalgebras

We develop the notion of the composition of two coalgebras, which arises naturally in higher category theory and the theory of species. We prove that the composition of two cofree coalgebras is cofree and give conditions which imply that the composition is a one-sided Hopf algebra. These conditions hold when one coalgebra is a graded Hopf operad $\mathcal{D}$ and the other is a connected graded coalgebra with coalgebra map to $\mathcal{D}$. We conclude with examples of these structures, where the factor coalgebras have bases indexed by the vertices of multiplihedra, composihedra, and hypercubes.
Finite-state dimension and real arithmetic

We use entropy rates and Schur concavity to prove that, for every integer k>=2, every nonzero rational number q, and every real number @a, the base-k expansions of @a, q+@a, and q@a all have the same finite-state dimension and the same finite-state strong dimension. This extends, and gives a new proof of, Wall's 1949 theorem stating that the sum or product of a nonzero rational number and a Borel normal number is always Borel normal.
Energy transfer in Hall-MHD turbulence: cascades, backscatter, and dynamo action

Scale interactions in Hall magnetohydrodynamics (MHDs) are studied using both the mean field theory derivation of transport coefficients, and direct numerical simulations in three space dimensions. In the magnetically dominated regime, the eddy resistivity is found to be negative definite, leading to large-scale instabilities. A direct cascade of the total energy is observed, although as the amplitude of the Hall effect is increased, backscatter of magnetic energy to large scales is found, a feature not present in MHD flows. The coupling between the magnetic and velocity fields is different than in the MHD case, and backscatter of energy from small-scale magnetic fields to large-scale flows is also observed. For the magnetic helicity, a strong quenching of its transfer is found. We also discuss non-helical magnetically forced Hall-MHD simulations where growth of a large-scale magnetic field is observed.
Aliasing computation using fault simulation with fault dropping

It is generally thought that accurate analysis of aliasing requires non-fault dropping fault simulation. We show that fault dropping is possible when computing the exact aliasing of modeled faults for common output response compression circuits. The fault dropping process is most effective when the test set size is small. Extensions to large test sets are also considered. We present a fault simulation procedure that takes maximum advantage of fault dropping and present experimental results to support its effectiveness. >
Spectral Stability of Noncharacteristic Isentropic Navier–Stokes Boundary Layers

Building on the work of Barker, Humpherys, Lafitte, Rudd, and Zumbrun in the shock wave case, we study stability of compressive, or shock-like, boundary layers of the isentropic compressible Navier–Stokes equations with γ-law pressure by a combination of asymptotic ODE estimates and numerical Evans function computations. Our analytical results include convergence of the Evans function in the shock and large-amplitude limits and stability in the large-amplitude limit, the first rigorous stability result for other than the nearly constant case, for all \({\gamma\geqq 1}\). Together with these analytical results, our numerical investigations indicate stability for γ ϵ [1, 3] for all compressive boundary-layers, independent of amplitude, save for inflow layers in the characteristic limit (not treated). Expansive inflow boundary-layers have been shown to be stable for all amplitudes by Matsumura and Nishihara using energy estimates. Besides the parameter of amplitude appearing in the shock case, the boundary-layer case features an additional parameter measuring displacement of the background profile, which greatly complicates the resulting case structure. Inflow boundary layers turn out to have quite delicate stability in both large-displacement (shock) and large-amplitude limits, necessitating the additional use of a mod-two stability index studied earlier by Serre and Zumbrun in order to decide stability.
On a vanishing conjecture appearing in the geometric Langlands correspondence

0.1. This paper should be regarded as a sequel to [7]. There it was shown that the geometric Langlands conjecture for GLn follows from a certain vanishing conjecture. The goal of the present paper is to prove this vanishing conjecture. Let X be a smooth projective curve over a ground field k. Let E be an m-dimensional local system on X, and let Bunm be the moduli stack of rank m vector bundles on X. The geometric Langlands conjecture says that to E we can associate a perverse sheaf FE on Bunm, which is a Hecke eigensheaf with respect to E. The vanishing conjecture of [7] says that for all integers n < m, a certain functor AvE , depending on E and a parameter d ∈ Z+, which maps the category D(Bunn) to itself, vanishes identically, when d is large enough. The fact that the vanishing conjecture implies the geometric Langlands conjecture may be regarded as a geometric version of the converse theorem. Moreover, as will be explained in the sequel, the vanishing of the functor AvE is analogous to the condition that the Rankin-Selberg convolution of E, viewed as an m-dimensional Galois representation, and an automorphic form on GLn with n < m is well-behaved. Both the geometric Langlands conjecture and the vanishing conjecture can be formulated in any of the sheaf-theoretic situations, e.g., Q -adic sheaves (when char(k) = ), D-modules (when char(k) = 0), and sheaves with coefficients in a finite field F (again, when char(k) = ). When the ground field is the finite field Fq and we are working with -adic coefficients, it was shown in [7] that the vanishing conjecture can be deduced from Lafforgue’s theorem that establishes the full Langlands correspondence for global fields of positive characteristic; cf. [9].
Extracting the shape and roughness of specular lobe objects using four light photometric stereo

We propose a noncontact method for the measurement of surface shape and surface roughness. The method, which we call "four light photometric stereo", uses four lights, which sequentially illuminate the object under inspection, and a video camera for taking images of the object. The method has successfully been applied to a number of real objects.
Costly and discrete communication: an experimental investigation

Language is an imperfect and coarse means of communicating information about a complex and nuanced world. We report on an experiment designed to capture this feature of communication. The messages available to the sender imperfectly describe the state of the world; however, the sender can improve communication, at a cost, by increasing the complexity or elaborateness of the message. Here the sender learns the state of the world, then sends a message to the receiver. The receiver observes the message and provides a best guess about the state. The incentives of the players are aligned in the sense that both sender and receiver are paid an amount which is increasing in the accuracy of the receiver’s guess. We find that the size of the language endogenously emerges as a function of the costs of communication. Specifically, we find that higher communication costs are associated with a smaller language. Although the equilibrium predictions do not perform well, this divergence occurs in a manner which is consistent with the experimental communication literature: overcommunication. We find that the sender’s payoffs, relative to equilibrium payoffs, are decreasing in the cost of communication. We also find that the receiver’s payoffs, relative to equilibrium payoffs, are increasing in the cost of communication. Finally, we find imperfections in coordination on the basis of the experimental labels.
Higgs branch localization in three dimensions

We show that the supersymmetric partition function of three-dimensional $ \mathcal{N} $ =2 R-symmetric Chern-Simons-matter theories on the squashed S 3 and on S 2 × S 1 can be computed with the so-called Higgs branch localization method, alternative to the more standard Coulomb branch localization. For theories that could be completely Higgsed by Fayet-Iliopoulos terms, the path integral is dominated by BPS vortex strings sitting at two circles in the geometry. In this way, the partition function directly takes the form of a sum, over a finite number of points on the classical Coulomb branch, of a vortex-string times an antivortex-string partition functions.
Are Revisions to USDA Crop Production Forecasts Smoothed

This article uses Nordhaus' framework to determine the efficiency of the revision process for USDA corn and soybean production forecasts over the 1970/1971 through 2004/2005 marketing years. Positive autocorrelation and consistency of directional changes in forecast revisions suggest these forecasts are “smoothed.” Evidence is provided that the loss in forecast accuracy due to smoothing is statistically and economically significant in several cases. A conservative bias in farm operators' assessments of yield potential and in the procedure for translating enumerator's information about plant fruit counts into objective yield estimates are identified as plausible sources of smoothing.