cssi/SciSciGPT-SciSciNet huggingface dataset:
Redistribution in a model of voting and campaign contributions

Abstract I propose a framework in which individual political participation can take two distinct forms, voting and contributing resources to campaigns, in a context in which the negligible impact of any individual's actions on aggregate outcomes is fully recognized by all agents. I then use the framework to reassess the relationship between inequality and redistribution. The model shows that, even though each contribution has a negligible impact, the interaction between contributions and voting leads to an endogenous wealth bias in the political process, as the advantage of wealthier individuals in providing contributions encourages parties to move their platforms closer to those individuals' preferred positions. This mechanism can in turn explain why the standard median-voter-based prediction, that more inequality produces more redistribution, has received little empirical support: higher inequality endogenously shifts the political system further in favor of the rich. In equilibrium, there is a non-monotonic relationship in which redistribution is initially increasing but eventually decreasing in inequality. I present some empirical evidence supporting the framework, using data on campaign contributions from US presidential elections. In particular, inequality increases contributions to Republicans, but not to Democrats, as predicted by the model.
Three-Dimensional Computation of Focused Beam Propagation through Multiple Biological Cells

The FDTD method was used to simulate focused Gaussian beam propagation through multiple inhomogeneous biological cells. To our knowledge this is the first three dimensional computational investigation of a focused beam interacting with multiple biological cells using FDTD. A parametric study was performed whereby three simulated cells were varied by organelle density, nuclear type and arrangement of internal cellular structure and the beam focus depth was varied within the cluster of cells. Of the organelle types investigated, it appears that the cell nuclei are responsible for the greatest scattering of the focused beam in the configurations studied. Additional simulations to determine the optical scattering from 27 cells were also run and compared to the three cell case. No significant degradation of two-photon lateral imaging resolution was predicted to occur within the first 40 microm of imaging depth.
What does the yield curve tell us about exchange rate predictability

Since the term structure of interest rates embodies information about future economic activity, we extract relative Nelson-Siegel (1987) factors from cross-country yield curve differences to proxy expected movements in future exchange rate fundamentals. Using monthly data for the United Kingdom, Canada, Japan, and the United States, we show that the yield curve factors predict exchange rate movements and explain excess currency returns one month to two years ahead. Our results provide support for the asset pricing formulation of exchange rate determination and offer an intuitive explanation to the uncovered interest parity puzzle by relating currency risk premiums to inflation and business cycle risks.
Design of fault-tolerant computers

Reliable performance of hardware has been a requirement for digital systems since the construction of the first digital computer. Improper functioning of the logic circuits in a digital system is manifested by logic faults, which are defined for this paper as "permanent or transient deviations of logic variables from the values specified in design."
Epistemological Foundations of Teaching and Learning through the Land-Grant System

Contemporary student learning styles are linked to foundational schools of philosophic thought about epistemology (the knowing process). For each learning style, strategies based on the philosophic principles are suggested for teaching adults through resident instruction and extension education. Looking ahead, the effectiveness of distance learning is examined in light of the epistemological perspectives.
Asymmetrical multiconnection three‐stage clos networks

In this paper, we study routing problems in a general class of asymmetrical three-stage Clos networks. This class covers many asymmetrical three-stage networks considered by earlier researchers. We derive necessary and sufficient conditions under which this class of networks is rearrangeable with respect to a set of multiconnections, i.e., connections between subsets of input and output terminals. We first model the routing problem in these networks as a network-flow problem. If the number of switching elements in the first and last stages of the network is O(f) and the number of switching elements in the middle stage is m, then the network-flow model yields a routing algorithm with running time O(mf3). We then show that the problem of routing a set of multiconnections in an asymmetrical Clos network can be transformed into the well-studied problem of routing a set of pairwise connections in a more symmetric form of the network. This approach results in a routing algorithm with complexity O(mK2), where K is the aggregate capacity of the interstage links in the network. © 1993 by John Wiley & Sons, Inc.
Kirby Elements and Quantum Invariants

We define the notion of a Kirby element of a ribbon category $\mathcal{C}$ (not necessarily semisimple). Kirby elements lead to 3-manifold invariants. We characterize a class of Kirby elements, the algebraic Kirby elements, in terms of the structure maps of a Hopf algebra in $\mathcal{C}$. This class is sufficiently large to recover the quantum invariants of 3-manifolds of Reshetikhin and Turaev, of Hennings, Kauffman and Radford, and of Lyubashenko when these are well defined. The cases of a semisimple ribbon category and of a category of representations are explored in detail.
Funnels, pathways, and the energy landscape of protein folding: A synthesis

The understanding, and even the description of protein folding is impeded by the complexity of the process. Much of this complexity can be described and understood by taking a statistical approach to the energetics of protein conformation, that is, to the energy landscape. The statistical energy landscape approach explains when and why unique behaviors, such as specific folding pathways, occur in some proteins and more generally explains the distinction between folding processes common to all sequences and those peculiar to individual sequences. This approach also gives new, quantitative insights into the interpretation of experiments and simulations of protein folding thermodynamics and kinetics. Specifically, the picture provides simple explanations for folding as a two-state first-order phase transition, for the origin of metastable collapsed unfolded states and for the curved Arrhenius plots observed in both laboratory experiments and discrete lattice simulations. The relation of these quantitative ideas to folding pathways, to uniexponential vs. multiexponential behavior in protein folding experiments and to the effect of mutations on folding is also discussed. The success of energy landscape ideas in protein structure prediction is also described. The use of the energy landscape approach for analyzing data is illustrated with a quantitative analysis of some recent simulations, and a qualitative analysis of experiments on the folding of three proteins. The work unifies several previously proposed ideas concerning the mechanism protein folding and delimits the regions of validity of these ideas under different thermodynamic conditions. © 1995 Wiley-Liss, Inc.
Synthesis of Twist−Twist π-Conjugated Di-sec-alkylstilbenes and Stilbene Polymers

Twist−twist π-conjugated (TTPC) π systems promise unique properties with their 90° twist angles. Di-sec-alkyl substituted stilbenes, 5, were prepared by low-valent titanium coupling of phenyl ketones, 4. Long alkyl chains stopped the coupling reaction. Stilbenes 5 were shown to be ∼90% TTPC. Inserting TTPC units into poly(p-phenylene) polymers created highly fluorescent, soluble, TTPC π systems with weak electronic segmentation for organic light emitting diode (OLED) studies.
Application of bi-State magnetic material to an automotive IPM starter/alternator machine

A new bi-state soft magnetic material has been developed that can have its normally high magnetic permeability reduced permanently to that of air by means of heat treatment. As a result, localized heating via laser or other means can be used to locally "unmagnetize" regions in machine laminations while retaining the high permeability of adjacent untreated regions. A 6 kW interior permanent magnet (IPM) direct-drive starter/alternator machine was used as the target for this investigation. Two alternative designs for the same set of starter/alternator specifications are presented using the new magnetic material for the rotor laminations. Lumped-parameter magnetic circuit models including saturation were used to design both machines and the electromagnetic performance results were subsequently confirmed using finite element analysis (FEA). These results indicate that the performance specifications can be met using this new material while significantly increasing the mechanical integrity of the rotor at high speeds. Advantages and limitations of using this new bi-state magnetic material in IPM machine designs for starter/alternators and other applications are discussed.
The Interplay between Transpiration and Runoff Formulations in Land Surface Schemes Used with Atmospheric Models

Abstract The Project for Intercomparison of Land-surface Parameterization Schemes (PILPS) has shown that different land surface models (LSMs) driven by the same meteorological forcing can produce markedly different surface energy and water budgets, even when certain critical aspects of the LSMs (vegetation cover, albedo, turbulent drag coefficient, and snowcover) are carefully controlled. To help explain these differences, the authors devised a monthly water balance model that successfully reproduces the annual and seasonal water balances of the different PILPS schemes. Analysis of this model leads to the identification of two quantities that characterize an LSM’s formulation of soil water balance dynamics: 1) the efficiency of the soil’s evaporation sink integrated over the active soil moisture range, and 2) the fraction of this range over which runoff is generated. Regardless of the LSM’s complexity, the combination of these two derived parameters with rates of interception loss, potential evaporation, ...
Microwave-assisted synthesis of functionalized flavones and chromones

Abstract A facile microwave synthesis of functionalized flavones and chromones via the cyclization of 1-(2-hydroxyaryl)-3-aryl-1,3-propanedione is described.
Synthesis of (Z)-(2,3-bis-hydroxymethyl)methylenecyclopropane analogues of purine nucleosides.

Abstract Synthesis of (Z)-(2,3-bis-hydroxymethyl)methylenecyclopropane analogues of nucleosides adenosine 10a, 10b, 10c and 17 is described. Epimerization of Feist's acid (11) using acetic anhydride gave cyclic anhydride 12 which was reduced in situ to give diol 13. Acetylation (compound 14) followed by addition of bromine led to dibromo derivative 15. Alkylation-elimination of adenine with 15 afforded, after deacetylation, analogue 10a. Similar treatment of 2-amino-6-chloropurine and 2,6-diaminopurine led to diacetates 16 and 18. Deprotection then gave compounds 17 and 10c. Hydrolysis of 17 furnished guanine analogue 10b. Compounds 10a, 10b or 10c were inactive against HCMV, HSV-1, HSV-2, EBV, VZV and HBV. Analogues 10a and 10b were also assayed for anti-HIV activity. Compound 10a was effective in HIV-1/MT-2 culture with EC50/CC50 33/> 100 µM but 10b was inactive. Analogue 10a was not a substrate for adenosine deaminase.
Indole- and indoline-based kainate analogues with antagonist activity at ionotropic glutamate receptors.

Abstract A conformationally constrained, indole-based kainate analogue was designed based on Gouaux’s X-ray structure of kainic acid bound to an iGluR2(S1S2) construct, a structural model for AMPA/kainate ionotropic glutamate receptors. In contrast to the parent kainic acid, a potent agonist, this compound, along with three structurally related analogues derived from synthetic intermediates, exhibited antagonist behavior towards KAR expressed in oocytes, a result that is rationalized by molecular modeling studies.
Sentinel Lymph Nodes in Cutaneous Melanoma

Examination of sentinel lymph nodes (SLN) has probably become the most popular method of early staging of patients who have cutaneous melanoma because SLN are considered to be the lymph nodes most likely to contain metastatic deposits; they can be examined in a more intense manner than in standard lymphadenectomy. There are several protocols to examine SLN but most of them use formalin-fixed, paraffin-embedded sections stained with hematoxylin and eosin with the addition of immunohistochemistry. By using these protocols, approximately 20% of patients who have cutaneous melanoma have melanoma cells in the SLN. Current studies are evaluating the possible therapeutic value of removal of positive SLN, but it is accepted by most authors that detection of positive SLN conveys an impaired prognosis for patients who have cutaneous melanoma.
Are State Workers Overpaid? Survey Evidence from Liquor Privatization in Washington State

Industry privatizations that result in exogenous job displacement of public employees can be exploited to estimate public sector wage rents. I report the findings of an original survey I administered to examine how wages of displaced government workers were affected by a 2012 privatization of liquor retailing in Washington State. Based on a panel difference-in-differences estimator I find that privatization reduced wages by $2.51 per hour or 17 percent compared to a counterfactual group of nearly identical non-displaced workers, with larger effects for women. I decompose wage losses into three rents identified in the literature: public sector rents, union premiums, and industry-specific human capital. Public sector wage premiums separately account for 85 to 90 percent of overall wage losses, while union premiums and industry-specific human capital account for just 10 to 15 percent. The results are consistent with a roughly 16 percent public sector wage premium.
Synthesis, crystal and electronic structure, and optical properties of two new chalcogenide-iodides: Ba3Q4I2 (Q = S, Se)

Two new ternary chalcogenide-iodides, Ba3S4I2 and Ba3Se4I2, were synthesized through high-temperature solid-state reactions, and their structures were determined via single-crystal X-ray diffraction. Both compounds are isostructural and crystallize in the monoclinic space group C2/c (no. 15) with unit cell parameters of a = 14.507(4)/15.080(7) A, b = 10.104(3)/10.400(5) A, c = 8.206(2)/8.383(4) A, β = 101.847(4)/103.206(8)°, and Z = 4 for Ba3S4I2/Ba3Se4I2, respectively. The crystal structure of Ba3Q4I2 (Q = S, Se) is constructed from Q22− dumbbells and isolated I1− anions, which are surrounded by Ba2+ cations. According to UV/Vis spectroscopy, Ba3S4I2 is a semiconductor with a bandgap of 2.45(5) eV. Quantum-chemical calculations predict that Ba3S4I2 and Ba3Se4I2 are wide bandgap semiconductors with bandgaps of 2.50 and 2.06 eV, respectively. Electron localization function analysis of chemical bonding indicates covalent interactions in the Q22− dumbbells.
Proactively accountable anonymous messaging in verdict

Among anonymity systems, DC-nets have long held attraction for their resistance to traffic analysis attacks, but practical implementations remain vulnerable to internal disruption or "jamming" attacks, which require time-consuming detection procedures to resolve. We present Verdict, the first practical anonymous group communication system built using proactively verifiable DC-nets: participants use public-key cryptography to construct DC-net ciphertexts, and use zero-knowledge proofs of knowledge to detect and exclude misbehavior before disruption. We compare three alternative constructions for verifiable DC-nets: one using bilinear maps and two based on simpler ElGamal encryption. While verifiable DC-nets incur higher computational overheads due to the public-key cryptography involved, our experiments suggest that Verdict is practical for anonymous group messaging or microblogging applications, supporting groups of 100 clients at 1 second per round or 1000 clients at 10 seconds per round. Furthermore, we show how existing symmetric-key DC-nets can "fall back" to a verifiable DC-net to quickly identify misbehavior, speeding up previous detections schemes by two orders of magnitude.
Service Learning in Athletic Training Education: It's About Time

Recent attempts at bringing our profession to a global population have been nothing short of encouraging. But how do we gauge our effectiveness and impact? I often read with pleasure the efforts of my colleagues as they foray into countries previously untouched by athletic trainers. At first glance, it seems to be a slam dunk academically. Combining professionals with students, taking them to exotic locations and touring world famous landmarks is indeed a profound thing, and previously, something unheard of in our field. I recall as an undergraduate student desperately wanting to study abroad for a semester, maybe even a year, only to be told it was possible but it would set me back a year clinically. While pedagogically it was the right thing to do, not studying abroad was a difficult pill to swallow. Now, I proudly see that programs and institutions around the country are providing athletic training students with opportunities to study abroad and receive course credit for their endeavors, which I think is a beautiful thing. The kicker, however, is that this is only the first step.
Type Targeted Testing

We present a new technique called type targeted testing, which translates precise refinement types into comprehensive test-suites. The key insight behind our approach is that through the lens of SMT solvers, refinement types can also be viewed as a high-level, declarative, test generation technique, wherein types are converted to SMT queries whose models can be decoded into concrete program inputs. Our approach enables the systematic and exhaustive testing of implementations from high-level declarative specifications, and furthermore, provides a gradual path from testing to full verification. We have implemented our approach as a Haskell testing tool called TARGET, and present an evaluation that shows how TARGET can be used to test a wide variety of properties and how it compares against state-of-the-art testing approaches.
Rechargeable Ca-Ion Batteries: A New Energy Storage System

As new uses for larger scale energy storage systems are realized, new chemistries that are less expensive or have higher energy density are needed. While lithium-ion systems have been well studied, the availability of new energy storage chemistries opens up the possibilities for more diverse strategies and uses. One potential path to achieving this goal is to explore chemistries where a multivalent ion such as Ca2+ or Mg2+ is the active species. Herein, we demonstrate this concept for a Ca-ion system utilizing manganese hexacyanoferrate (MFCN) as the cathode to intercalate Ca reversibly in a dry nonaqueous electrolyte. Through characterization via X-ray absorption near-edge spectroscopy, it is determined that only the manganese changes oxidation state during cycling with Ca. X-ray diffraction indicates the MFCN maintains its crystallinity during cycling, with only minor structural changes associated with expansion and contraction. Furthermore, we have demonstrated the first rechargeable Ca-ion battery uti...
Prejudice and racial matches in employment

Abstract We develop a model in which some employers hold unobservable racial prejudice towards black workers. Workers, however, observe a signal of prejudice status – the presence of a black supervisor. Jobs in firms with black supervisors hold higher option value for black workers, because they are less likely to face prejudice-based termination. Hence, black workers are willing to accept employment with lower expected match quality from firms with black supervisors. We derive predictions on differences in wages and job stability across supervisor race and prejudice levels and find empirical support for them using unique longitudinal data on workers’ supervisors and state-level measures of prejudice.
On the Doorstep of the Information Age: Recent Adoption of Precision Agriculture

The adoption of precision agriculture, which encompasses a suite of farm-level information technologies, can improve the efficiency of input use and reduce environmental harm from the overapplication of inputs such as fertilizers and pesticides. Still, the adoption of precision agricultural technologies and practices has been less rapid than envisioned a decade ago. Using Agricultural Resource Management Survey (ARMS) data collected over the past 10 years, this report examines trends in the adoption of four key information technologies — yield monitors, variable-rate application technologies, guidance systems, and GPS maps — in the production of major field crops. While yield monitoring is now used on over 40 percent of U.S. grain crop acres, very few producers have adopted GPS maps or variable-rate input application technologies.
Substitution-Permutation Networks, Pseudorandom Functions, and Natural Proofs

This article takes a new step towards closing the gap between pseudorandom functions (PRF) and their popular, bounded-input-length counterparts. This gap is both quantitative, because these counterparts are more efficient than PRF in various ways, and methodological, because these counterparts usually fit in the substitution-permutation network paradigm (SPN), which has not been used to construct PRF.We give several candidate PRF Fi that are inspired by the SPN paradigm. Most of our candidates are more efficient than previous ones. Our main candidates are as follows.—F1 : {0,1}n → {0,1}n is an SPN whose S-box is a random function on b bits given as part of the seed. We prove that F1 resists attacks that run in time ≤ 2eb.—F2 : {0,1}n → {0,1}n is an SPN where the S-box is (patched) field inversion, a common choice in practical constructions. We show that F2 is computable with boolean circuits of size n ⋅ logO(1)n and that it has exponential security 2Ω(n) against linear and differential cryptanalysis.—F3 : {0,1}n → {0,1} is a nonstandard variant on the SPN paradigm, where “states” grow in length. We show that F3 is computable with TC0 circuits of size n1 p e, for any e > 0, and that it is almost 3-wise independent.—F4 : {0,1}n → {0,1} uses an extreme setting of the SPN parameters (one round, one S-box, no diffusion matrix). The S-box is again (patched) field inversion. We show that F4 is computable by circuits of size n ⋅ logO(1)n and that it fools all parity tests on ≤20.9n outputs.Assuming the security of our candidates, our work narrows the gap between the Natural Proofs barrier and existing lower bounds in three models: circuits, TC0 circuits, and Turing machines.
Posterior interosseous-nerve syndrome secondary to rheumatoid synovitis.

Three additional cases of posterior interosseous-nerve paralysis secondary to rheumatoid arthritis were seen. All were initially diagnosed as extensor tendon ruptures and in one patient the extensor tendons were explored before proper diagnosis was made. The condition is a compression neuritis of the posterior interosseous nerve secondary to elbow synovitis bulging anteriorly against the overlying supinator muscle. Treatment by injection of steroids was successful in one patient; synovectomy cured the condition in the second; and a tendon transfer was used in the third.
Effects of Storage Impoundments on Water Quality

Changes in physical, bacteriological, sanitary-chemical, and mineral quality of reservoir waters in Tennessee Valley that have been observed during past 20 yr; conclusions and principles are believed applicable to forecasting changes likely to occur in any reservoir.
Computation of Two- and Three-Dimensional Confidence Regions With the Likelihood Ratio

ABSTRACTThe asymptotic results pertaining to the distribution of the log-likelihood ratio allow for the creation of a confidence region, which is a general extension of the confidence interval. Two- and three-dimensional regions can be displayed visually to describe the plausible region of the parameters of interest simultaneously. While most advanced statistical textbooks on inference discuss these asymptotic confidence regions, there is no exploration of how to numerically compute these regions for graphical purposes. This article demonstrates the application of a simple trigonometric transformation to compute two- and three-dimensional confidence regions; we transform the Cartesian coordinates of the parameters to create what we call the radial profile log-likelihood. The method is applicable to any distribution with a defined likelihood function, so it is not limited to specific data distributions or model paradigms. We describe the method along with the algorithm, follow with an example of our method...
A new spin on causality constraints

Causality in a shockwave state is related to the analytic properties of a four-point correlation function. Extending recent results for scalar probes, we show that this constrains the couplings of the stress tensor to light spinning operators in conformal field theory, and interpret these constraints in terms of the interaction with null energy. For spin-1 and spin-2 conserved currents in four dimensions, the resulting inequalities are a subset of the Hofman-Maldacena conditions for positive energy deposition. It is well known that energy conditions in holographic theories are related to causality on the gravity side; our results make a connection on the CFT side, and extend it to non-holographic theories.
Altruistically unbalanced kidney exchange

Although a pilot national live-donor kidney exchange program was recently launched in the US, the kidney shortage is increasing faster than ever. A new solution paradigm is able to incorporate compatible pairs in exchange. In this paper, we consider an exchange framework that has both compatible and incompatible pairs, and patients are indierent over compatible pairs. Only two-way exchanges are permitted because of institutional constraints. We explore the structure of Pareto-ecient matchings in this framework. We show that under Pareto-ecient matchings, the same number of patients receive transplants, and it is possible to construct Pareto-ecient matchings that match the same incompatible pairs while matching the least number of compatible pairs. We extend the celebrated Gallai-Edmonds Decomposition in the combinatorial optimization literature to our new framework. We also conduct comparative static exercises on how this decomposition changes as new compatible pairs join the pool.
Discriminating Quantum Optical Beam-splitter Channels with Number Diagonal Signal States: Applications to Quantum Reading and Target Detection

We consider the problem of distinguishing, with minimum probability of error, two optical beam-splitter channels with unequal complex-valued reflectivities using general quantum probe states entangled over $M$ signal and ${M}^{\ensuremath{'}}$ idler mode pairs of which the signal modes are bounced off the beam splitter while the idler modes are retained losslessly. We obtain a lower bound on the output state fidelity valid for any pure input state. We define number-diagonal signal (NDS) states to be input states whose density operator in the signal modes is diagonal in the multimode number basis. For such input states, we derive series formulas for the optimal error probability, the output state fidelity, and the Chernoff-type upper bounds on the error probability. For the special cases of quantum reading of a classical digital memory and target detection (for which the reflectivities are real valued), we show that for a given input signal photon probability distribution, the fidelity is minimized by the NDS states with that distribution and that for a given average total signal energy ${N}_{s}$, the fidelity is minimized by any multimode Fock state with ${N}_{s}$ total signal photons. For reading of an ideal memory, it is shown that Fock state inputs minimize the Chernoff bound. For target detection under high-loss conditions, a no-go result showing the lack of appreciable quantum advantage over coherent state transmitters is derived. A comparison of the error probability performance for quantum reading of number state and two-mode squeezed vacuum state (or EPR state) transmitters relative to coherent state transmitters is presented for various values of the reflectances. While the nonclassical states in general perform better than the coherent state, the quantitative performance gains differ depending on the values of the reflectances. The experimental outlook for realizing nonclassical gains from number state transmitters with current technology at moderate to high values of the reflectances is argued to be good.
Transmission of the International Price of Maize to the Mexican Regions

Are variations in international prices of corn transmitted to local markets in Mexico? How homogeneous is the transmission across the different regions of the country? I estimate to what extent changes in international prices of maize are transmitted to the different Mexican sub-national regions. The price of white maize in the Mexican regions is cointegrated with the international price of yellow maize but not with the international price of the Argentina Up River maize. The north has the largest price transmission elasticity among the Mexican regions, although all of the regions exhibit similar elasticities. Changes in the international prices have permanent effects on the average of local prices in Mexico.
NEUROPHYSIOLOGIC MONITORING DURING ACUTE AND PROGRESSIVE COMPRESSION INJURY OF THE SPINAL CORD EXPERIMENTALLY INDUCED IN PIGS

Summary Statement The spinal cord showed marked sensibility to acute compression causing complete and irreversible injury. On the contrary, the spinal cord has more ability for adaptation to slow progressive compression mechanisms having the possibility of neural recovery after compression release. Introduction The aim of this experimental study was to establish, by means of neurophysiologic monitoring, the degree of compression needed to cause neurologic injury to the spinal cord, and analyze whether these limits are different making fast or slow compression. Material and Methods Spinal cord was exposed from T7 to T11 in 5 domestic pigs with a mean weight of 35 kg. The T8 and T9 spinal roots were also exposed. A pair of sticks, attached to a precise compression device, was set up to both sides of the spinal cord between T8 and T9 roots. Sequentially, the sticks were approximated 0.5 mm every 2 minutes causing progressive spinal cord compression. An acute compression of the spinal cord was also reproduced by a 2.5 mm displacement of the sticks. Cord to cord motor evoked potentials were obtained with two epidural catheters, stimulating proximal to T6 and recording below the compression level, distal to T10, for each sequential approach of the sticks. Results The mean width of the dural sac was 7.1 mm. For progressive compression, increasing latency and decreasing amplitude of the evoked potentials were observed after a mean displacement of the sticks of 3.2 ± 0.9 mm, the evoked potential finally disappearing after a mean displacement of 4.6 ± 1.2 mm. The potential returned 16.8 ± 3.2 minutes after the compression was stopped in every case. The evoked potentials immediately disappeared after an acute compression 2.5 ± 0.3 mm, without any sign of recovering after 30 minutes. Conclusion The proposed experimental model replicates the mechanism of a spinal cord injury caused by medially displaced screws into the spinal canal, causing therefore lateral compression to the spinal cord. The spinal cord showed marked sensibility to acute compression, which caused complete and irreversible injury. On the contrary, the spinal cord has more ability for adaptation to progressive and slow compression mechanisms. From a clinical point of view, it seems mandatory to avoid maneuvers of rapid mobilization or acute, even minimal, contusions of the thoracic cord.
An Economic Analysis of Fumigation Alternatives, the Methyl Bromide Ban, and its Implication: Evidence from the Florida Tomato Industry

Florida tomato industry is suffering from current methyl bromide phase-out under Montreal Protocol. Methyl bromide and its alternative fumigation strategies for producers are analyzed. This article seeks to provide growers and policy makers with scientific information on optimal fumigation strategies in terms of economic feasibility, financial efficiency and risk efficiency through partial budget analysis and stochastic efficiency with respect to a function.
DNS study of particle-bed-turbulence interactions in an oscillatory wall-bounded flow

Particle-resolved direct numerical simulations (DNS) are performed to investigate the behaviour of an oscillatory flow field over a rough bed, corresponding to the experimental set-up of Keiller & Sleath (J. Fluid Mech., vol. 73 (04), 1976, pp. 673–691) for transitional and turbulent flows over a range of Reynolds numbers (95–400) based on the Stokes-layer thickness. It is shown that the roughness modulates the near-bed turbulence, produces streamwise horseshoe structures which then undergo distortion and breaking, and therefore reduces the large-scale anisotropy. A fully developed equilibrium turbulence is observed in the central part of the oscillation cycle, with two-component turbulence in the near-bed region and cigar-shaped turbulence in the outer region. A double averaging of the flow field reveals spatial inhomogeneities at the roughness scale and alternate paths of energy transport in the turbulent kinetic energy (TKE) budget. Contrary to the unidirectional, steady flow over rough beds, bed-induced production terms are important and comparable to the shear production term. It is shown that the near-bed velocity and pressure fluctuations are non-Gaussian, a result of critical importance for the modelling of incipient motion of sediment grains.
Structural Focalization

Focusing, introduced by Jean-Marc Andreoli in the context of classical linear logic [Andreoli 1992], defines a normal form for sequent calculus derivations that cuts down on the number of possible derivations by eagerly applying invertible rules and grouping sequences of non-invertible rules. A focused sequent calculus is defined relative to some nonfocused sequent calculus; focalization is the property that every nonfocused derivation can be transformed into a focused derivation.In this article, we present a focused sequent calculus for propositional intuitionistic logic and prove the focalization property relative to a standard presentation of propositional intuitionistic logic. Compared to existing approaches, the proof is quite concise, depending only on the internal soundness and completeness of the focused logic. In turn, both of these properties can be established (and mechanically verified) by structural induction in the style of Pfenning's structural cut elimination without the need for any tedious and repetitious invertibility lemmas. The proof of cut admissibility for the focused system, which establishes internal soundness, is not particularly novel. The proof of identity expansion, which establishes internal completeness, is a major contribution of this work.
Human Computation

Tasks like image recognition are trivial for humans, but continue to challenge even the most sophisticated computer programs. This talk discusses a paradigm for utilizing human processing power to solve problems that computers cannot yet solve. Traditional approaches to solving such problems focus on improving software. I advocate a novel approach: constructively channel human brainpower using computer games. For example, the ESP Game, described in this talk, is an enjoyable online game - many people play over 40 hours a week - and when people play, they help label images on the Web with descriptive keywords. These keywords can be used to significantly improve the accuracy of image search. People play the game not because they want to help, but because they enjoy it.
Resident Networks and Corporate Connections: Evidence from World War II Internment Camps

Using customs and port authority data, we show that firms are significantly more likely to trade with countries that have a large resident population near their firm headquarters, and that these connected trades are their most valuable international trades. Using the formation of World War II Japanese internment camps to isolate exogenous shocks to local ethnic populations, we identify a causal link between local networks and firm trade. Firms are also more likely to acquire target firms, and report increased segment sales, in connected countries. Our results point to a surprisingly large role of immigrants as economic conduits for firms.
Between Critical and Normative Theory: Predictive Political Theory as a Deweyan Realism

Over the last decade, a call for greater “realism” in political theory has challenged the goals and methods that are implicit in much contemporary “normative” theory. However, realists have yet to ...
Optimizing Paving Mixtures for Durable, Cost-Effective, and Sustainable Concrete

This paper presents 7-, 28-, and either 56- or 90-day compressive strength data from 17 field projects collected by the Federal Highway Administration’s Mobile Concrete Laboratory from 13 states. This paper also presents data on the concrete strength required to open to construction traffic and data on permeability for the same projects. The data indicate that, in most cases, the 28-day strength requirement of the respective agencies was met in only 7 days. On average, the 28-day strength requirement was exceeded by more than 60%, and the 56- or 90-day strength exceeded the 28-day strength requirement by more than 80%. This paper argues that such high strengths, especially high early strengths, are not warranted and can be detrimental in many ways to the long-term performance of concrete pavements. Overall, the strength data from all 17 field projects indicate that there is a huge opportunity to optimize the mixture designs typically produced. From the mixture design information obtained from these projec...
Synthesis of the pyridine core of cyclothiazomycin.

A highly convergent synthesis of the pyridine core of the thiopeptide antibiotic cyclothiazomycin has been developed based on a [2 + 2 + 2] cyclotrimerization key step. The regioselective assembly of the heterocyclic center of this important class of antibiotics takes advantage of a temporary silicon tether and the ruthenium-catalyzed cyclotrimerization reaction of a diyne and an electron-poor thiazole nitrile.
Spin Hall effect and irreversible thermodynamics: Center-to-edge transverse current-induced voltage

We examine the Dyakonov and Perel theory of the Spin Hall effect (SHE) from the viewpoint of irreversible thermodynamics, which is more constraining than the symmetry arguments of pure phenomenology. As thermodynamic driving forces we include the thermal gradient, the gradient of the electrochemical potential (rather than the potential gradient and density gradient separately), and the ``internal'' magnetic field that is thermodynamically conjugate to the magnetization. In turn, we obtain the form of bulk transport coefficients relating the fluxes to the thermodynamic forces. Relative to Dyakonov and Perel, in addition to the new terms due to thermal gradients, the Onsager relations require three new (nonlinear) terms in the current density, and minor revisions in the current density and spin current density. For a longitudinal current along a strip, the center-to-edge transverse voltage difference, due both to the $\ensuremath{-}\ensuremath{\beta}\stackrel{P\vec}{P}\ifmmode\times\else\texttimes\fi{}\stackrel{P\vec}{E}$ term of of the number current density $\stackrel{P\vec}{q}$ and to one of the new current density terms, is calculated. An ac capacitative probe likely would not significantly disturb this effect. An appendix explicitly relates the anomalous Hall Effect to the term in the (vector) number flux that is Onsager related to the SHE term in the (tensor) spin flux.
Biodiesel Fuels from Supercritical Fluid Processing: Quality Evaluation with the Advanced Distillation Curve Method and Cetane Numbers

The volatility of biodiesel fuel samples produced by supercritical (SC) transesterification (TE) of triglyceride feedstocks of chicken fat and soybean oil was determined by the advanced distillation curve (ADC) method. Particularly high temperatures (e.g., 400 °C) of the SCTE process partially decomposed the polyunsaturated fatty acid methyl esters (FAMEs) to lower molecular FAMEs (∼C6–C15) and ∼C10–C17 hydrocarbons. These lighter fuel components shifted the first portion of the distillation curves toward that of #2 diesel fuel. This means that biodiesel fuels produced by SCTE at ∼400 °C exhibit higher overall volatility when compared to commercial biodiesel samples produced by conventional catalytic TE. Other important fuel properties such as ignition delay via cetane numbers could also be improved. This information will permit efficient fuel system and combustion chamber designs to optimize fuel utilization in diesel engines, decrease of fuel consumption, and emission mitigation.
An Efficient, Regioselective Amination of 3,5-Disubstituted Pyridine N-Oxides Using Saccharin as an Ammonium Surrogate

A process for the regioselective amination of unsymmetrical 3,5-substituted pyridine N-oxides has been developed utilizing cheap, readily available saccharin as an ammonium surrogate. High conversions of the corresponding saccharin adducts have been achieved under mild reaction conditions. In situ deprotection under acidic conditions allows for a one-pot process to substituted aminopyridines. High regioselectivities were obtained from a variety of 3,5-disubstituted pyridine N-oxides.
Inferring network structure in non-normal and mixed discrete-continuous genomic data.

Summary Inferring dependence structure through undirected graphs is crucial for uncovering the major modes of multivariate interaction among high-dimensional genomic markers that are potentially associated with cancer. Traditionally, conditional independence has been studied using sparse Gaussian graphical models for continuous data and sparse Ising models for discrete data. However, there are two clear situations when these approaches are inadequate. The first occurs when the data are continuous but display non-normal marginal behavior such as heavy tails or skewness, rendering an assumption of normality inappropriate. The second occurs when a part of the data is ordinal or discrete (e.g., presence or absence of a mutation) and the other part is continuous (e.g., expression levels of genes or proteins). In this case, the existing Bayesian approaches typically employ a latent variable framework for the discrete part that precludes inferring conditional independence among the data that are actually observed. The current article overcomes these two challenges in a unified framework using Gaussian scale mixtures. Our framework is able to handle continuous data that are not normal and data that are of mixed continuous and discrete nature, while still being able to infer a sparse conditional sign independence structure among the observed data. Extensive performance comparison in simulations with alternative techniques and an analysis of a real cancer genomics data set demonstrate the effectiveness of the proposed approach.
Secondary Structure, Backbone Dynamics, and Structural Topology of Phospholamban and Its Phosphorylated and Arg9Cys-Mutated Forms in Phospholipid Bilayers Utilizing 13C and 15N Solid-State NMR Spectroscopy

Phospholamban (PLB) is a membrane protein that regulates heart muscle relaxation rates via interactions with the sarcoplasmic reticulum Ca2+ ATPase (SERCA). When PLB is phosphorylated or Arg9Cys (R9C) is mutated, inhibition of SERCA is relieved. 13C and 15N solid-state NMR spectroscopy is utilized to investigate conformational changes of PLB upon phosphorylation and R9C mutation. 13C═O NMR spectra of the cytoplasmic domain reveal two α-helical structural components with population changes upon phosphorylation and R9C mutation. The appearance of an unstructured component is observed on domain Ib. 15N NMR spectra indicate an increase in backbone dynamics of the cytoplasmic domain. Wild-type PLB (WT-PLB), Ser16-phosphorylated PLB (P-PLB), and R9C-mutated PLB (R9C-PLB) all have a very dynamic domain Ib, and the transmembrane domain has an immobile component. 15N NMR spectra indicate that the cytoplasmic domain of R9C-PLB adopts an orientation similar to P-PLB and shifts away from the membrane surface. Domain ...
Nickel-catalyzed synthesis of aryl trifluoromethyl sulfides at room temperature.

Inexpensive nickel–bipyridine complexes were found to be active for the trifluoromethylthiolation of aryl iodides and aryl bromides at room temperature using the convenient [NMe4][SCF3] reagent.
Ligand-Free Copper-Catalyzed Arylation of Amidines

Copper-catalyzed cross-coupling reactions of amidine salts were utilized to synthesize monoarylated amidines in moderate to high yields with ligand-free conditions. DMF was the superior solvent for the N-arylation of benzamidines, while MeCN was used in the formation of N-aryl amidines in moderate to high yield.
Cooperative capture synthesis: yet another playground for copper-free click chemistry

Click chemistry describes a family of modular, efficient, versatile and reliable reactions which have acquired a pivotal role as one of the most useful synthetic tools with a potentially broad range of applications. While copper(I)-catalysed alkyne–azide cycloaddition is the most widely adopted click reaction in the family, the fact that it is cytotoxic restricts its practice in certain situations, e.g., bioconjugation. Consequently, researchers have been exploring the development of copper-free click reactions, the most popular example so far being strain-promoted alkyne–azide cycloadditions. An early example of copper-free click reactions that is rarely mentioned in the literature is the cucurbit[6]uril (CB6) catalysed alkyne–azide cycloaddition (CB-AAC). Despite the unique ability of CB-AAC to generate mechanically interlocked molecules (MIMs) – in particular, rotaxanes – its slow reaction rate and narrow substrate acceptance limit its scope. In this Tutorial Review, we describe our efforts of late in developing the fundamental principles and practical applications of a new copper-free click reaction – namely, cooperative capture synthesis, whereby introducing a cyclodextrin (CD) as an accelerator in CB-AAC, hydrogen bonding networks are formed between the rims of CD and CB6 in a manner that is positively cooperative, giving rise to a high level of pre-organisation during efficient and quick rotaxane formation. For example, [4]rotaxanes can be prepared nearly quantitatively within a minute in water. Furthermore, we have demonstrated that CB-AAC can accommodate a wider substrate tolerance by introducing pillararenes as promoters. To date, we have put cooperative capture synthesis into practice by (i) preparing polyrotaxanes containing up to 200 rings in nearly quantitative yields, (ii) trapping conformational isomers of polymacrocycles as rings in rotaxanes, (iii) demonstrating solid-state fluorescence and Forster resonance energy transfer (FRET) processes by fixing the fluorophores in a rotaxane and (iv) establishing the principle of supramolecular encryption in the preparation of dynamically and reversibly tunable fluorescent security inks.