cssi/SciSciGPT-SciSciNet huggingface dataset:
Exploiting Adaptive and Collaborative AUV Autonomy for Detection and Characterization of Internal Waves

Advances in the fields of autonomy software and environmental sampling techniques for autonomous underwater vehicles (AUVs) have recently allowed for the merging of oceanographic data collection with the testing of emerging marine technology. The Massachusetts Institute of Technology (MIT) Laboratory for Autonomous Marine Sensing Systems (LAMSS) group conducted an Internal Wave Detection Experiment in August 2010 with these advances in mind. The goal was to have multiple AUVs collaborate autonomously through onboard autonomy software and real-time underwater acoustic communication to monitor for the presence of internal waves by adapting to changes in the environment (specifically the temperature variations near the thermocline/pycnocline depth). The experimental setup, implementation, data, deployment results, and internal wave detection and quantification results are presented in this paper.
Separated flow predictions using a hybrid k-L/backflow model

A new hybrid one-equation k-L /backflow model has been used to compute several turbulent flow problems involving detached flow regions. The model incorporates algebraic near-wall treatments for the kinetic energy of turbulence fc, the length scale L, and the eddy viscosity /*,. The near-wall formulation depends on whether the flow is attached or detached. This approach obviates the need to use wall functions. Agreement between predictions and experimental data is generally very good throughout the Mach number range.
Alkenes from cyclic sulfates and thionocarbonates of 1,2-diols via tellurium chemistry

Treatment of 1,2-diol cyclic sulfates (1,3,2-dioxathiolane 2,2-dioxides) with telluride ion, generated in situ by reduction of the element, yields alkenes rapidly (10 min- 2 h) under mild conditions (0 °C to room temperature). The reaction is stereospecific, e.g. meso-2,3-diphenylethane 2,3-diol → cis-stilbene; d,l-2,3-diphenylethane-2,3-diol → trans-stilbene. Unsaturated mannose and ribose derivatives have been obtained, and diethyl (-)-tartrate gives diethyl fumarate. The reaction may be performed with 0.1 equiv or less of elemental tellurium in the presence of a stoichiometric amount of reducing agent. Reaction of telluride ion with cyclic thionocarbonates (1,3-dioxolane-2-thiones) of meso- and d,l-1,2-diphenylethane-1,2-diol yields cis- and trans-stilbene, respectively.
Synthesis of 5-Ethyl-2-pyrimidinone-2′-deoxyriboside as a New Potential Antiviral Agent

Abstract 5-Ethyl-2-pyrimidinone (5) and its 2′-deoxyribosides 9 (α) and 10 (β) have been synthesized in several steps starting from 5-ethyluracil. 10 is presented for evaluation against herpes virus infection.
Fluid Consumption by Mexican Women during Pregnancy and First Semester of Lactation

The objective of this study was to describe daily fluid consumption in a sample of pregnant or lactating adult women. Women between 18 and 45 years of age, residents of Mexico City, stratified by socioeconomic status were asked to register their total fluid intake during 7 consecutive days. A total of 153 pregnant and 155 lactating women were recruited. On average, they drank 2.62 L/day and 2.75 L/day, respectively. Forty-one percent of pregnant women drank less than the recommended 2.3 L fluids/day, and 54% of women drank less than the recommended intake of 2.7 L/day during the first semester of lactation. Plain water contributed to 33% of total fluid intake, and sugar-sweetened beverages (SSB) contributed to 38% of total fluid intake. Up to 50% of pregnant and lactating women drank more than 1 L/day of SSB, which contributed to 632 kcal/day (27.5% of recommended dietary intake) and to 700 kcal/day (28% of recommended dietary intake), respectively. The high rates of overweight and obesity found in Mexican population, particularly among women, should alert us to the consumption of SSB during pregnancy and lactation, as excessive intake of these beverages may increase the risks of obesity, diabetes mellitus, and other chronic disorders.
Capital Rules: The Domestic Politics of International Regulatory Harmonization

In the past fifteen years, financial regulators from the developed world have attempted to create international regulatory standards in a variety of financial issue areas. Their negotiations are notable for the stark variation in the preferences of regulators toward international regulatory harmonization. Certain regulators actively resist any attempts at regulatory harmonization, while others are vocal in their advocacy for an international agreement. When will regulators seek to harmonize their rules with their foreign counterparts? I propose a principal-agent framework for analyzing regulator behavior that views international harmonization as a means of satisfying domestic political pressures. The framework predicts that regulators are more likely to seek international regulatory harmonization when confidence in the stability of financial institutions is declining, and when competitive pressures are increasing from foreign firms facing less stringent regulations. I explore the consistency of the framework with two important cases in the history of international financial regulation: the negotiations among bank regulators leading up to the 1988 Basel Accord on bank capital adequacy, and the negotiations among securities regulators over capital adequacy for securities firms between 1988 and 1992.I thank Gabe Aguilera, David Bach, Ethan Bueno de Mesquita, Dan Carpenter, Bill Clark, Mark Copelovitch, Jeff Frieden, Dan Gingerich, Dan Ho, Devesh Kapur, Joseph N. R. Sanberg, Ross Schaap, Allan Stam, Matt Stephenson, two anonymous reviewers, and the editors of IO for helpful comments, discussions, and feedback. I am also indebted to the thirty current and former regulators and financial industry executives who participated in interviews to advance this project. Finally, I thank the Weatherhead Center for International Affairs and the Center for European Studies for research funding.
Thermal Scale Modeling of Spacecraft: An Experimental Investigation

Equilibrium temperature measurements of thermal scale model used for spacecraft testing in cold wall vacuum chamber
Gas—Liquid Chromatography on Polymers. II. Temperature Coefficients for Polyisobutylene—Hydrocarbons

Abstract Studies of the thermodynamics of polymer solutions by conventional static methods at very high concentrations of polymer are relatively few. Therefore, comparisons between enthalpy parameters obtained by the methods of glc and vapor sorption are limited to only a few cases. One other system for which comparable data are available is natural rubber and benzene. In this case, the glc value of κs is +0.18, while κs = 0.01 ± 0.1 has been obtained by vapor sorption. It appears from the somewhat sparse data collected to date that estimates of the residual enthalpy obtained by glc methods are as reliable as those obtained by static methods. Corrections for gas phase imperfection must be very carefully applied.
Superluminality in DGP

We reconsider the issue of superluminal propagation in the DGP model of infrared modified gravity. Superluminality was argued to exist in certain otherwise physical backgrounds by using a particular, physically relevant scaling limit of the theory. In this paper, we exhibit explicit five-dimensional solutions of the full theory that are stable against small fluctuations and that indeed support superluminal excitations. The scaling limit is neither needed nor invoked in deriving the solutions or in the analysis of its small fluctuations. To be certain that the superluminality found here is physical, we analyze the retarded Green's function of the scalar excitations, finding that it is causal and stable, but has support on a widened light-cone. We propose to use absence of superluminal propagation as a method to constrain the parameters of the DGP model. As a first application of the method, we find that whenever the 4D energy density is a pure cosmological constant and a hierarchy of scales exists between the 4D and 5D Planck masses, superluminal propagation unavoidably occurs.
X-ray Nova XTE J1550-564: optical observations

We report the identification of the optical counterpart of the X-ray transient XTE J1550-564 described in two companion papers by Sobczak et al. and Remillard et al. We find that the optical source brightened by ≈4 mag over the quiescent counterpart seen at B≈22 on a SERC survey plate and then decayed by ≈1.5 mag over the 7 week-long observation period. There was an optical response to the large X-ray flare described by Sobczak et al., but it was much smaller and delayed by ≈1 day.
A unified canonical form for controllable and uncontrollable linear dynamical systems

A linear transformation is proposed which will transform an arbitrary (constant) linear dynamical system p into a certain standard (canonical) form. This particular canonical form coincides with the well-known phase-variable canonical form [l]-[5] for the case of completely controllable, scalar input, linear dynamical systems and coincides with a canonical form recently proposed by Luenberger [6] and Wonham [7] in the case of completely controllable, vector input, linear dynamical systems. For linear dynamical systems which are not completely controllable, the canonical form proposed herein displays explicitly: (i) the sub-system of p which is completely controllable and (ii) the sub-system of p which is completely uncontrollable. The explicit identification of these two sub-systems permits us to effectively implement the important fundamental stabilization theorem for constant linear dynamical systems and also a useful theorem on spectrum controllability for linear dynamical systems. An important feature...
Fractionalized phase in an XY – Z 2 gauge model

We study a model with fractional quantum numbers using Monte Carlo techniques. The model is composed of bosons interacting though a ${Z}_{2}$ gauge field. We find that the system has three phases: a phase in which the bosons are confined, a fractionalized phase in which the bosons are deconfined, and a phase in which the bosons are condensed. The deconfined phase has a ``topological'' order due to the degeneracy in the ground state of the gauge field. We discuss an experimental test proposed by Senthil and Fisher that uses the topological order to determine the existence of a deconfined, fractionalized phase.
Blade Row Interaction Effects on Flutter and Forced Response

A procedure to calculate intrablade row unsteady aerodynamic interactions is developed that relies upon results from isolated blade row unsteady aerodynamic analyses. Using influence coefficients that express the unsteady forces on one blade row due to the motion of another, an aeroelastic model is obtained that accounts for the coupling of the vibratory responses of multiple blade rows. The model is applied to two model config- urations, each consisting of three blade rows. The flutter analysis shows that interaction effects can be desta- bilizing, and the forced response analysis shows that interaction effects can result in a significant increase in the resonant response of a blade row. N the flutter analysis of a turbomachine blade row, the blade row is commonly assumed to be isolated—distur- bances created by the vibrating blades are free to propagate away from the blade row without being disturbed. Therefore, any reflections of these outgoing waves by other structural members or nonuniformiti es in the mean-flowfield are ne- glected. Although the forced response problem is typically concerned with blade row interaction, forced response anal- yses also generally neglect any reflections of outgoing waves. However, in an engine environment, structural elements such as neighboring blade rows or struts and nonuniformities in the mean-flowfield will reflect some of this wave energy back toward the vibrating blades, causing additional unsteady forces on them. Whether or not these reflected waves can signifi- cantly affect the aeroelastic stability or forced response of a blade row is a question of fundamental importance. Several investigations have focused on the unsteady aero- dynamic interaction between two rigid blade rows. Kaji and Okazaki1 investigated the interaction of two blade rows for the purpose of predicting rotor-stator interaction noise. They obtained a simultaneous solution to the unsteady lift distri- butions on both of the blade rows. Hanson2 modified Smith's3 isolated blade row unsteady aerodynamic analysis to predict rotor-stator interaction noise, essentially extending Kaji and Okazaki's work to include effects of frequency scattering and mean-flow turning by the blade rows. For a counter-rotati ng propfan in incompressibl e flow, Chen and Williams4 used a panel method to determine the unsteady loads on rigid pro- peller blades. From the point-of-view of the present investi- gation, all of these investigations are somewhat limited be- cause they did not delve into the aeroelastic problem and they were limited to two blade rows. One investigation that did consider the aeroelastic effects of interactions of a vibrating blade row and an adjacent struc- ture was that of Williams et al. 5 A three-dimensio nal linear- ized compressible panel method was used to calculate the unsteady aerodynamics of a ducted fan. The aeroelastic anal- ysis allowed flexibility of both the fan and the duct. The duct was found to have a destabilizing effect on the fan. A number of time-accurate solutions to the Euler and Na- vier-Stokes equations for rotor-stator interaction have been
Deep pockets in lattices and other groups

We show the nonexistence of deep pockets in a large class of groups, extending a result of Bogopol'sii. We then give examples of important groups (namely lattices in Nil and Sol) which have deep pockets.
An Investigation of the Protection Afforded a Spacecraft by a Thin Shield

Results are presented from a theoretical and experimental program to investigate the damage that would be inflicted upon a missile, satellite, or space vehicle by a hypervelocity particle. Most of the work has been directed toward thin shield impacts. The problem is treated theoretically by examining the wave motion in an impacting projectile and shield, and consideration is given to heating effects. Theoretical considerations and experimental results lead to the following conclusions: 1) A thin shield is effective because it fragments and spreads the projectile and shield debris and, at high velocities, may melt or vaporize the fragments. 2) The optimum shield to minimize penetration is the one that melts or vaporizes the majority of debris coming through the shield. The shield thickness required to do this is found to decrease with increasing impact velocity. Total damage is not denned on this basis only, and failure may occur through momentum loading of the shielded structure. 3) Shield parameters such as strength and density, on an equiweight basis, are not important. 4) Hole diameter in a shield is proportional to impact velocity and to shield thickness to the twothirds power.
Unstable Surface Waves in Running Water

We consider the stability of periodic gravity free-surface water waves traveling downstream at a constant speed over a shear flow of finite depth. In case the free surface is flat, a sharp criterion of linear instability is established for a general class of shear flows with inflection points and the maximal unstable wave number is found. Comparison to the rigid-wall setting testifies that the free surface has a destabilizing effect. For a class of unstable shear flows, the bifurcation of nontrivial periodic traveling waves is demonstrated at all wave numbers. We show the linear instability of small nontrivial waves that appear after bifurcation at an unstable wave number of the background shear flow. The proof uses a new formulation of the linearized water-wave problem and a perturbation argument. An example of the background shear flow of unstable small-amplitude periodic traveling waves is constructed for an arbitrary vorticity strength and for an arbitrary depth, illustrating that vorticity has a subtle influence on the stability of free-surface water waves.
Selective nitration versus oxidative dealkylation of hydroquinone ethers with nitrogen dioxide

Abstract Various alkyl-substituted p-dialkoxybenzenes (ArH) react readily with nitrogen dioxide (NO2) in dichloromethane solution via either nitration (ArNO2) or oxidative dealkylation to quinones (Q). Spectral transients indicate that these coupled processes from the dialkoxybenzene radical cation (ArH+·) formed as the common reactive intermediate from electron-transfer in the disproprtionated precursor [ArH, NO+] N03−. In fast subsequent steps. ArH+· undergoes homolytic coupling with NO2 (which leads to aromatic nitration) and nucleophilic attack of NO3− (which results in oxidative dealkylation). As such, the competition between nitration and oxidative dealkylation is effectively modulated by solvent polarity and added nitrate.
Ab initio prediction of ring strain enthalpies of cyclic amine-boranes

Abstract Ring strain enthalpies for a series of cyclic amine-boranes (1-azonia-2-boratacycloalkanes) were calculated from MP4(SDTQ)/6-31G ∗ //MP2/6-31G ∗ energies by the group equivalent method. Small rings exhibit smaller RSEs than do the corresponding cycloalkanes; larger rings exhibit RSEs essentially identical to those of the corresponding cycloalkanes.
Effect of Cell Geometry on Energy Absorption of Honeycombs Under In-Plane Compression

This study examines the energy absorption capabilities of cellular honeycombs subjected to in-plane compression. ABAQUS nonlinear finite element analysis is used and cellular honeycombs with different cell geometries are considered. Simulation results are validated against previously published results for 30 deg cellular honeycombs. For various cell angles, comparison of simulation results for full-size honeycombs and their single-cell analogs suggest that the energy absorption can be accurately determined using the single-cell model. Results indicate that for cells with equal wall length, the specific energy absorption capability increases with increasing cellular honeycomb angle. A cell wall length study shows that the specific energy absorption (energy absorption per unit mass) is higher for cells with shorter vertical walls. A cell wall thickness study shows that increasing wall thickness increases the specific energy absorption. A vertical wall thickness study shows that the vertical walls should be thick enough not to buckle, but no thicker, providing the maximum energy absorption for minimum weight. A detailed analysis of cell deformation for different honeycombs and an insight of the underlying physics behind the differences in energy absorption capabilities observed for the different honeycombs are also presented.
Translating owl and semantic web rules into prolog: Moving toward description logic programs

We are researching the interaction between the rule and the ontology layers of the Semantic Web, by comparing two options: 1) using OWL and its rule extension SWRL to develop an integrated ontology/rule language, and 2) layering rules on top of an ontology with RuleML and OWL. Toward this end, we are developing the SWORIER system, which enables efficient automated reasoning on ontologies and rules, by translating all of them into Prolog and adding a set of general rules that properly capture the semantics of OWL. We have also enabled the user to make dynamic changes on the fly, at run time. This work addresses several of the concerns expressed in previous work, such as negation, complementary classes, disjunctive heads, and cardinality, and it discusses alternative approaches for dealing with inconsistencies in the knowledge base. In addition, for efficiency, we implemented techniques called extensionalization, avoiding reanalysis, and code minimization.
A saturable-transformer digital amplifier with diode switching

Synopsis: A digital amplifier of simple non-critical design incorporating a saturable voltage transformer is described. The clock is a 2-phase, sine-wave voltage source in the 100-kc range. In structure and mode of operation the amplifier stage is particularly suited for use with 2-level diode gating to provide the "and" and "or" logical functions. A complementer employing two saturable transformers provides the "not" function. The volt-second transfer characteristic of the stage critically determines the stability of transmission of binary signals in a long register, or in any closed loop. Factors governing the shape of this characteristic are discussed. The over-all characteristic for n stages is then derived and used to predict binary transmission stability.
Fingerprint matching by genetic algorithms

Fingerprint matching is still a challenging problem for reliable person authentication because of the complex distortions involved in two impressions of the same finger. In this paper, we propose a fingerprint-matching approach based on genetic algorithms (GA), which tries to find the optimal transformation between two different fingerprints. In order to deal with low-quality fingerprint images, which introduce significant occlusion and clutter of minutiae features, we design a fitness function based on the local properties of each triplet of minutiae. The experimental results on National Institute of Standards and Technology fingerprint database, NIST-4, not only show that the proposed approach can achieve good performance even when a large portion of fingerprints in the database are of poor quality, but also show that the proposed approach is better than another approach, which is based on mean-squared error estimation.
Segmentation of medical images through competitive learning.

Abstract In image analysis applications, segmentation of gray-level images into meaningful regions is an important low-level processing step. Various approaches to segmentation investigated in the literature, in general, use either local information of gray-level values of pixels (region growing based methods, for example) or the global information (histogram threshold based methods, for example). Application of these approaches for segmenting medical images often does not provide satisfactory results. Medical images are usually characterized by low local contrast and noisy or faded features causing unacceptable performance of local information based segmentation methods. In addition, because of a large amount of structural information found in medical images, global information based segmentation methods yield inadequate results in region extraction. We present a novel approach to image segmentation that combines local contrast as well as global gray-level distribution information. The presented method adaptively learns useful features and regions through the use of a normalized contrast function as a measure of local information and a competitive learning based method to update region segmentation incorporating global information about the gray-level distribution of the image. In this paper, we present the framework of such a self organizing feature map, and show the results on simulated as well as real medical images.
Chemistry of p,p'-dibenzenes

Abstract The 3,4-tetramethylene derivative 6 of p,p′-dibenzene 1 has been synthesized for the first time. As in the case of its benzo-analog 5 , its principal thermal reaction is its rearrangement to the corresponding cis-syn-o,o′-isomers.
The naked T Tauri stars - The low-mass pre-main sequence unveiled

The search for low-mass premain-sequence (PMS) stars associated with X-ray sources in regions of star formation is discussed. The survey to date has revealed at least 30 low-mass PMS stars in the Tau-Aur region, and a comparable number in Oph. These stars are the naked T Tau stars, unveiled versions of the well-known classical T Tau stars. The properties of these newly discovered PMS stars and their relation to the classical T Tau stars are discussed, and it is concluded that the naked T Tau stars are the true low-mass PMS stars, and that the observable characteristics defining the classical T Tau stars are due to the interaction of an underlying, fairly normal star with a dominant circumstellar environment. The impact the naked T Tau stars are likely to have on models of the PMS evolution of low-mass stars is considered.
Outline of an ultracorrector compensating for all primary chromatic and geometrical aberrations of charged-particle lenses

A novel ultracorrector is outlined which compensates for the primary and secondary first-order chromatic aberrations and all third-order geometrical aberrations of electron optical systems with a straight axis. Owing to the imposed symmetry conditions on the fields and the paraxial fundamental rays, the corrector does not introduce aberrations with 2-fold symmetry. The chromatic aberrations are corrected by means of crossed electric magnetic quadrupoles while the third-order geometrical aberrations are eliminated by octopoles. By placing these elements at distinct positions within the corrector, it is possible to successively eliminate the third-order aberrations in such a way that each subsequent correction does not affect the aberrations corrected in the preceding correction steps.
On the Impulse Control of Jump Diffusions

Regularity of the impulse control problem for a nondegenerate $n$-dimensional jump diffusion with infinite activity and finite variation jumps was recently examined in [M. H. A. Davis, X. Guo, and G. Wu, SIAM J. Control Optim., 48 (2010), pp. 5276--5293]. Here we extend the analysis to include infinite activity and infinite variation jumps. More specifically, we show that the value function $u$ of the impulse control problem satisfies $u\in W^{2,p}_{\mathrm{loc}}(\mathbb{R}^{n})$.
On the political economy of guest worker programs in agriculture

Guest workers have provided a source of agricultural labor supply in many countries. Recent legislative proposals on immigration reform in the United States have renewed discussions about the role of guest worker programs, and highlighted the arguments for and against such programs. Even within the agricultural sector, there has not been strong broad-based support for an expansion in the number of guest workers. A model is developed that considers competing interests between commodity groups (horticulture crops and grain crops) to explain this lack of support, and then a series of simulations are conducted to highlight the possible economic effects of an expanded guest worker program. Results suggest that an increase in the labor supply would have much larger economic impacts for horticultural producers and firms in the supporting input markets. Furthermore, under some conditions, simulation outcomes show how an increase in the labor supply may lead to small revenue losses for both producers and input suppliers in grain markets.
Peptide-based targeting of fluorescent zinc sensors to the plasma membrane of live cells

Combining fluorescent zinc sensors with the facile syntheses and biological targeting capabilities of peptides, we created green- and blue-emitting probes that (i) are readily prepared on the solid-phase, (ii) retain the photophysical and zinc-binding properties of the parent sensor, and (iii) can be directed to the extracellular side of plasma membranes in live cells for detection of mobile zinc.
Resource Endowments and Technological Change in Agriculture: U.S. and Japanese Experiences in International Perspective

THE United States and Japan, despite enormous differences in resource endowments, have attained high rates of growth in agricultural output and productivity. The patterns of growth in productivity and resource use are as contrasting as their resource endowments. This study searches for the common thread in the U.S. and Japanese agricultural growth by appraising the historical experiences of the two countries within a cross-country perspective.
Unified supersymmetric model of naturally small Dirac neutrino masses and the axionic solution of the strong CP problem

Using the particle content of the fundamental 27 supermultiplet of E6, naturally small Dirac neutrino masses are obtained in the context of SU(3)C×SU(2)L×U(1)Y×U(1)χ, where U(1)χ comes from the decomposition E6→SO(10)×U(1)ψ, then SO(10)→SU(5)×U(1)χ. New observable consequences are predicted at the TeV scale. An axionic solution of the strong CP problem may be included at no extra cost.
CAN INEFFICIENT TRADERS CREATE VALUE

I examine the aggregate expected profit generated by informed traders of diverse ability in a competitive market. I assume that efficient traders get perfect information on asset values whereas inefficient traders get noisy information. In the presence of order size restrictions, I show that the aggregate expected profit generated by efficient and inefficient traders together can be higher than that generated by efficient traders alone. Thus, inefficient traders can create value in a constrained trading environment.
Intramolecular Diels-Alder reactions of vinylboranes. A highly stereoselective two-step decalin synthesis

Abstract 1,7,9-Decatrienylboranes, generated in situ from either hydroboration of 5 or boron-tin exchange with 6 , undergo very highly stereoselective intramolecular Diels-Alder reactions.
Reactions of BrCl with alkyl radicals.

Abstract It is demonstrated that photohalogenations of low reactivity substrates with BrCl occurs mainly with Cl· selectivity. With tertiary or benzylic hydrogens in the substrate, mainly Br· selectivity is observed. These observations are rationalized, taking into account the relative concentrations of halogen atoms and their respective rates of hydrogen abstractions. The resultant radicals react with BrCl to make (RBr/RCl) in ratios between 1 and 15.
Phototransamidation as a Method for the Synthesis of N-Glycosyl Asparagines.

N-Glycosyl asparagines were synthesized by a mild photochemical coupling method in which a photoreactive amide of an aspartic acid’s β-carboxyl group is condensed with an aminosaccharide. Upon excitation, the γ-carbon becomes susceptible to nucleophilic attack and the obtained N-glycosyl asparagines, which may be useful building blocks for the synthesis of N-glycopeptides and neoglycopeptides, are generated in good yields.
Legalized Abortion and the Homicide of Young Children: An Empirical Investigation

Recent research has drawn a link, sometimes a causal link, between the legalization of abortion in the late 1960s and early 1970s and the precipitous decline in crime in the 1990s. Abortion is posited to have reduced the number of potential victims and potential perpetrators, and the potential effect is examined when these individuals would be reaching their high-crime years. We examined a more proximal potential association between legalized abortion and homicide, specifically, the homicide of young children. Assuming that abortions occurred when the family had insufficient resources for the birth, one could hypothesize that children would have been at higher risk of homicide if born into these circumstances. We examined 1960-1998 U.S. mortality data for children under 5 years of age using an interrupted time series design. The legalization of abortion was not associated with a sudden change in child homicide trends. It was, however, associated with a steady decrease in the homicides of toddlers (i.e., 1- to 4-year-olds) in subsequent years. Although in the predicted direction, the decrease in homicides of children under 1 year of age was not statistically significant. Competing explanations that could be examined in the data (e.g., changes in mortality classification) do not account for the findings.
Do Analysts and Auditors Use Information in Accruals

Existing research indicates that firms with high accruals are more likely to experience future earnings problems, but that investors' expectations, as reflected in stock prices, do not appear to anticipate these problems. In this paper, we directly examine the published opinions of two types of professional investor intermediaries to see if they provide investors with information concerning the future earnings problems experienced by firms with high accruals. First, we examine the earnings forecasts of sell-side analysts. We show that analysts' earnings forecasts do not incorporate the predictable future earnings declines associated with high accruals. Second, we examine the behavior of independent auditors. We find no evidence that auditors signal the future earnings problems associated with high accruals through either their audit opinions or through auditor changes. Overall, our evidence indicates that analysts and auditors do not alert investors to the future earnings problems associated with high accruals, thus corroborating previous findings that investors do not appear to anticipate these problems.
Dynamic Safety-Stocks for Asymptotic Optimality in Stochastic Networks

This paper concerns control of stochastic networks using state-dependent safety-stocks. Three examples are considered: a pair of tandem queues; a simple routing model; and the Dai-Wang re-entrant line. In each case, a single policy is proposed that is independent of network load ρ•. The following conclusions are obtained for the controlled network in each case, where the finite constant K0 is independent of load: The policy is fluid-scale asymptotically optimal, and satisfies the bound 2 $$ eta_ast \le \eta \le \eta_\ast + K_0 \log(\eta_\ast),\quad 0 \le \rho_\bullet \le 1, $$ where η* is the optimal steady-state cost. These results are based on the construction of an approximate solution to the average-cost dynamic programming equations using a perturbation of the value function for an associated fluid model. Moreover, a new technique is introduced to obtain fluid-scale asymptotic optimality for general networks modeled in discrete time. The proposed policy is myopic with respect to a perturbation of the value function for the fluid model.
Enantioselective synthesis of imperanene via enzymatic asymmetrization of an intermediary 1,3-diol

[reaction: see text] Using a chemoenzymatic synthetic strategy, (S)-imperanene and its (R)-enantiomer has been synthesized from vanillin in nine steps. The key step in the synthesis involves the use of Pseudomonas cepacia lipase (PS-30) to induce asymmetrization of the intermediary prochiral 1,3-diol in >97% ee.
Heme/Copper Terminal Oxidases

Spatially well-organized electron-transfer reactions in a series of membrane-bound redox proteins form the basis for energy conservation in both photosynthesis and respiration. The membrane-bound nature of the electron-transfer processes is critical, as the free energy made available in exergonic redox chemistry is used to generate transmembrane proton concentration and electrostatic potential gradients. These gradients are subsequently used to drive ATP formation, which provides the immediate energy source for constructive cellular processes. The terminal heme/copper oxidases in respiratory electron-transfer chains illustrate a number of the thermodynamic and structural principles that have driven the development of respiration. This class of enzyme reduces dioxygen to water, thus clearing the respiratory system of low-energy electrons so that sustained electron transfer and free-energy transduction can occur. By using dioxygen as the oxidizing substrate, free-energy production per electron through the chain is substantial, owing to the high reduction potential of O{sub 2} (0.815 V at pH 7). 122 refs.
Physicians’ Knowledge of and Willingness to Prescribe Naloxone to Reverse Accidental Opiate Overdose: Challenges and Opportunities

Naloxone, the standard treatment for heroin overdose, is a safe and effective prescription drug commonly administered by emergency room physicians or first responders acting under standing orders of physicians. High rates of overdose deaths and widely accepted evidence that witnesses of heroin overdose are often unwilling or unable to call 9-1-1 has led to interventions in several US cities and abroad in which drug users are instructed in overdose rescue techniques and provided a “take-home” dose of naloxone. Under current Food and Drug Administration (FDA) regulations, such interventions require physician involvement. As part of a larger study to evaluate the knowledge and attitudes of doctors towards providing drug treatment and harm reduction services to injection drug users (IDUs), we investigated physician knowledge and willingness to prescribe naloxone. Less than one in four of the respondents in our sample reported having heard of naloxone prescription as an intervention to prevent opiate overdose, and the majority reported that they would never consider prescribing the agent and explaining its application to a patient. Factors predicting a favorable attitude towards prescribing naloxone included fewer negative perceptions of IDUs, assigning less importance to peer and community pressure not to treat IDUs, and increased confidence in ability to provide meaningful treatment to IDUs. Our data suggest that steps to promote naloxone distribution programs should include physician education about evidence-based harm minimization schemes, broader support for such initiatives by professional organizations, and policy reform to alleviate medicolegal concerns associated with naloxone prescription. FDA re-classification of naloxone for over-the-counter sales and promotion of nasal-delivery mechanism for this agent should be explored.
A Bridge to Somewhere: Mapping State and Congressional Ideology on a Cross-institutional Common Space

second, even when such data exist, scaling ideal points within a single state is an inadequate approach. No comparisons can be made between these estimates and those for other state legislatures or for Congress. our project provides a solution. We exploit a new comparative dataset of state legislative roll calls to generate ideal points for legislators. taking advantage of the fact that state legislators sometimes go on to serve in Congress, we create a common ideological scale. Using these bridge actors, we estimate state legislative ideal points in congressional common space for 11 states. We present our results and illustrate how these scores can be used to address important topics in state and legislative politics.
Electromechanical Regenerative Actuator With Fault-Tolerance Capability for Automotive Chassis Applications

This paper investigates an electromechanical regenerative (EMR) actuator for automotive chassis applications. The actuator system comprises an electric machine, a ball screw, and a controller. The designs of these three components are examined first. Control algorithms are then developed for both converter and inverter topologies. A prototype actuator has been fabricated and tested in the laboratory. Test results indicate that the regenerative system achieves the required performance and has the capability to regenerate power to improve real-world fuel economy.
Rapid and Selective Reduction of Functionalized Fluoroaryl Azides to the Corresponding Anilines with Stannous Chloride Dihydrate

Abstract Nitrofluorophenyl azide 1, azidofluorobenzaldehyde 2, azidofluorobenzoate ester 3, and aminonitrofluorophenyl azide 4 were selectively reduced in high yield to the corresponding anilines 5–8 with excess stannous chloride dihydrate in 2:1 ethyl acetate/ethanol at ambient temperature.
An adaptive finite element approach to atomic-scale mechanics—the quasicontinuum method

Mixed atomistic and continuum methods offer the possibility of carrying out simulations of material properties at both larger length scales and longer times than direct atomistic calculations. The quasicontinuum method links atomistic and continuum models through the device of the finite element method which permits a reduction of the full set of atomistic degrees of freedom. The present paper gives a full description of the quasicontinuum method, with special reference to the ways in which the method may be used to model crystals with more than a single grain. The formulation is validated in terms of a series of calculations on grain boundary structure and energetics. The method is then illustrated in terms of the motion of a stepped twin boundary where a critical stress for the boundary motion is calculated and nanoindentation into a solid containing a subsurface grain boundary to study the interaction of dislocations with grain boundaries.
Program refinement in fair transition systems

Refinement of programs is investigated in the context of fair transition systems. Two kinds of refinements, property preserving and fixed-point preserving, are defined. Conditions are developed under which common program transformations such as data refinement are property preserving and fixed-point preserving. These conditions and relevant program refinements are illustrated through a number of examples.
How Does the Sun Shine

Abstract Assuming that MSW neutrino oscillations occur and ignoring all solar physics except for the constraint that nuclear fusion produces the solar luminosity, we show that new solar neutrino experiments are required to rule out empirically the hypothesis that the sun shines via the CNO cycle.
Structure and magnetic properties of oxychalcogenides A2F2Fe2OQ2 (A = Sr, Ba; Q = S, Se) with Fe2O square planar layers representing an antiferromagnetic checkerboard spin lattice.

The oxychalcogenides A2F2Fe2OQ2 (A = Sr, Ba; Q = S, Se), which contain Fe2O square planar layers of the anti-CuO2 type, were predicted using a modular assembly of layered secondary building units and subsequently synthesized. The physical properties of these compounds were characterized using magnetic susceptibility, electrical resistivity, specific heat, 57Fe Mossbauer, and powder neutron diffraction measurements and also by estimating their exchange interactions on the basis of first-principles density functional theory electronic structure calculations. These compounds are magnetic semiconductors that undergo a long-range antiferromagnetic ordering below 83.6−106.2 K, and their magnetic properties are well-described by a two-dimensional Ising model. The dominant antiferromagnetic spin exchange interaction between S = 2 Fe2+ ions occurs through corner-sharing Fe−O−Fe bridges. Moreover, the calculated spin exchange interactions show that the A2F2Fe2OQ2 (A = Sr, Ba; Q = S, Se) compounds represent a rare e...
UPPER BOUNDS IN THE OHTSUKI–RILEY–SAKUMA PARTIAL ORDER ON 2-BRIDGE KNOTS

In this paper we use continued fractions to study a partial order on the set of 2-bridge knots derived from the work of Ohtsuki, Riley, and Sakuma. We establish necessary and sufficient conditions for any set of 2-bridge knots to have an upper bound with respect to the partial order. Moreover, given any 2-bridge knot K1 we characterize all other 2-bridge knots K2 such that {K1, K2} has an upper bound. As an application we answer a question of Suzuki, showing that there is no upper bound for the set consisting of the trefoil and figure-eight knots.
Implications of military stabilization efforts on economic development and security: The case of Iraq!

Abstract The United States used a combination of economic, political, and military means to effect change in Iraq. Most notably, the United States used a buildup of security forces, the “surge”, as an intervention to stabilize Iraq. This article uses structural change tests to determine the effect of the intervention on security and economic metrics of success. There appears to be compelling evidence that several events may have had a direct influence on security variables with the surge being one of the events. There is little to suggest that the surge was the primary intervention that enhanced economic development and political order.
Negligible Nuclear Spin Relaxation Concurrent with Extensive Rotational Cooling in Jet Expansions of Methyl Halides, from Analysis of Hexapole Focusing

Experimental data of the UCLA group (S.R. Gandhi et al. Chem. Phys. Lett., 1986, 132: 6; J. Phys. Chem., 1987, 91: 5437) on focusing and rotational state selection of supersonic, seeded beams of methyl halide molecules via the electrostatic hexapole technique are analyzed to ascertain the extent of spin conversion (i.e., proton spin orientational relaxation) accompanying rotational cooling. Just as for the ortho-para hydrogen system, the rate of spin conversion (here, between the two different symmetry species, A and E, of the methyl halide molecules) is found to be negligible compared to the extensive collision-induced rotational cooling (down to rotational temperatures as low as 2 K).
A prototype system for detecting the radio-frequency pulse associated with cosmic ray air showers

Abstract The development of a system to detect the radio-frequency (RF) pulse associated with extensive air showers of cosmic rays is described. This work was performed at the CASA/MIA array in Utah, with the intention of designing equipment that can be used in conjunction with the Auger Giant Array. A small subset of data (less than 40 out of a total of 600 h of running time), taken under low-noise conditions, permitted upper limits to be placed on the rate and strength of pulses accompanying showers with energies around 10 17 eV .
A New Method for the Stereoselective Synthesis of α- and β-Glycosylamines Using the Burgess Reagent

Although glycosylamines constitute an important group of carbohydrates from the standpoint of biology and medicine, methods for their synthesis typically lack substrate generality and/or result in variable stereoselectivity, especially in complex contexts. In this communication, we report an operationally simple method for the synthesis of both alpha- and beta-glycosylamines using the Burgess reagent that overcomes many of these limitations in a bare minimum of synthetic steps.
A note on knot Floer homology of links

Ozsvath and Szabo proved that knot Floer homology determines the genera of knots in S^3. We will generalize this deep result to links in homology 3-spheres, by adapting their method. Our proof relies on a result of Gabai and some constructions related to foliations. We also interpret a theorem of Kauffman in the world of knot Floer homology, hence we can compute the top filtration term of the knot Floer homology for alternative links.
Auctions with an inexpert bidder

Abstract We consider an auction in which the behavior of one potential bidder departs mildly from full rationality. We show that the presence of such an inexpert bidder can be enough to discourage all of an infinitely large population of fully rational potential bidders from entering an auction. Furthermore, this departure from full rationality does not reduce the inexpert bidder’s payoff.
Gynecologic Issues in the HIV-Infected Woman

In this article, gynecologic conditions of increased importance in the HIV-infected woman are discussed. Women living with HIV may have an increase in menstrual disorders, lower genital tract neoplasias, gynecologic surgery, and sexually transmitted infections. The literature relevant to choosing a method of contraception for HIV-positive women is also discussed. With the advent of HAART, seropositive women are now facing issues around longevity, such as menopause and disorders of bone mineral density, as well as those associated with fertility.
Green functions of higher-order differential operators

The Green functions of the partial differential operators of even order acting on smooth sections of a vector bundle over a Riemannian manifold are investigated via the heat kernel methods. We study the resolvent of a special class of higher-order operators formed by the products of second-order operators of Laplace type defined with the help of a unique Riemannian metric but with different bundle connections and potential terms. The asymptotic expansion of the Green functions near the diagonal is studied in detail in any dimension. As a by-product a simple criterion for the validity of the Huygens principle is obtained. It is shown that all the singularities as well as the non-analytic regular parts of the Green functions of such high-order operators are expressed in terms of the usual heat kernel coefficients ak for a special Laplace type second-order operator.