cssi/SciSciGPT-SciSciNet huggingface dataset:
Pair Production by Relativistic Electrons from an Intense Laser Focus

A preliminary discussion is given of electron-positron pair production by means of electrons accelerated to relativistic velocities at the focus of a laser beam. First, the pair cross-section was numerically evaluated near its energy threshold. Then, two methods of relativistic electron production by focused laser light were considered: the coherent oscillation of electrons, and the acceleration of a few high velocity electrons by plasma waves excited by laser-driven instabilities. It was found that the first method would produce pairs for neodymium laser light which is close to the limits of achievable intensities (1019–1020 W/cm2). The second method, however, may be capable of producing pairs at lower intensities.
z-pinch wiggler

There have been several proposals for wigglers making use of the intense electromagnetic fields available with high-density plasmas. A novel approach is described here, i.e. the use of a hollow z-pinch generated plasma, which allows for the exploitation of the high fields generated by plasma oscillations without the electron beam passing through the plasma. Simple compression of an axial magnetic field by a hollow plasma tube can achieve significant field strengths with moderate currents, thus providing a simple mechanism, the cyclotron maser, for achieving generation of coherent radiation. The proposed approach is inherently flexible in allowing different wiggler designs including the ability to do tapering. Several z-pinch wiggler variations are presented and discussed. The most advantageous feature of the proposed hollow z-pinch wiggler is the elimination of plasma on axis, so that beam-plasma scattering is also eliminated. Thus, it maintains the advantages of other plasma devices and improves on them by returning the beam to its preferred high vacuum environment. >
Crash characteristics and injuries of victims impaired by alcohol versus illicit drugs

Alcohol has long been associated with injury, but the relationship between other drugs and injury is less clear. Blood samples from 894 patients presenting to two Emergency Departments for treatment of motor vehicle injury sustained in passenger cars, station wagons, vans and pickup trucks, were tested for alcohol and other drugs. Results were related to demographic characteristics, including prior history of alcohol and drug use; crash characteristics; and injury characteristics. Alcohol was associated with more severe crashes, but other drugs, in the absence of alcohol, were not. The crashes involving drugs but no alcohol were very similar to those involving neither alcohol nor drugs.
Space telerobotics: A few more hurdles

This paper discusses three milestones that must be reached before telerobotics technology is ready for a useful role on the space station: (1) A telerobotic manipulator, which integrates remote manned control with automation and robotics, must be designed. A new, unique design for such a system is described. (2) Technology that is developed and demonstrated in the lab must be integrated and validated in flight-scale systems. Current technology thrusts at NASA Langley Research Center are described, along with an approach to transferring the technology to flight. (3) The role of telerobotics must be defined, and its benefits quantified. Possible roles as an adjunct and as an alternative to extravehicular activity are discussed.
On the timeliness of tax reform

Abstract This paper analyzes efficient government reactions to unanticipated tax avoidance. Quickly reforming tax laws to reduce the effectiveness of new tax avoidance techniques prevents widespread adoption, but indirectly encourages the rapid development of new avoidance methods if prior users are permitted to retain their tax benefits. Tax reforms that immediately prevent new avoidance mean that innovators need not fear imitation by competitors, and cannot rely on copying the innovations of others. Such an activist reform agenda diverts greater resources into tax avoidance activity, and might thereby lead to a faster rate of tax base erosion, than would a less reactive government strategy. Efficient government policy therefore entails either the retroactive elimination of tax savings, with possible associated costs, or else a deliberate pace of tax reform in response to taxpayer innovation.
Gauge Theories on the Coulomb branch

We construct the world-volume action of a probe D3-brane in AdS5×S 5 with N units of flux. It has the field content, symmetries, and dualities of the U(1) factor of N = 4 U(N + 1) super Yang–Mills theory, spontaneously broken to U(N)×U(1) by being on the Coulomb branch, with the massive fields integrated out. This motivates the conjecture that it is the exact effective action, called a highly effective action (HEA). We construct an SL(2, ) multiplet of BPS soliton solutions of the D3-brane theory (the conjectured HEA) and show that they reproduce the electrically charged massive states that have been integrated out as well as magnetic monopoles and dyons. Their charges are uniformly spread on a spherical surface, called a soliton bubble, which is interpreted as a phase boundary.
Mode selective directional coupler for NLC

The design method for a high power, X-band 50 dB, circular to rectangular directional coupler is presented. The circular guide is over moded and is intended to operate in TE/sub 01/-mode. The rectangular guide operates at the fundamental TE/sub 10/ mode. A small percentage of higher order modes in the circular guide can cause considerable errors in the measurements because the magnitude of the axial magnetic field of these modes is higher than that of the operating mode, especially near their cutoff. We used a Hamming window pattern for the coupling slots to achieve mode selectivity. Comparison of theory and experiment are presented. >
Computational aspects of spectral factorization and the tangential Schur algorithm

Recently, several mathematical results and techniques related to the Nevanlinna-Pick interpolation problem have found important applications in a variety of control system theoretic problems. The solution of the Nevanlinna-Pick problem is obtained in an inductive way through the Schur algorithm. In an earlier work (1988), the author used the Schur algorithm as a means to achieve spectral factorization. Here, he continues that work, in particular, investigating the Schur algorithm in the context of the tangential Nevanlinna-Pick problem. This provides a computationally simple scheme for spectral factorization of matrix-valued functions. >
Progress in Health around the World

Abstract Health is a key component of human development. This article looks at how health is measured, and the convergence of health across countries. We argue that health measures should account for illness as well as mortality, but in practice life expectancy is a reasonable proxy for population health. While health is improving we see two distinct groups of countries in the data, clustering around different long run steady states. Many countries have experienced large health gains without prior income gains and in countries not affected by HIV/AIDS the last 40 years have been a success story in terms of health.
Sheppard's correction for variances and the "quantization noise model"

In this paper, we examine the relevance of Sheppard's correction for variances and (both the original and a valid weak form of) the so-called "quantization noise model" to understanding the effects of integer rounding on continuous random variables. We further consider whether there is any real relationship between the two. We observe that the strong form of the model is not really relevant to describing rounding effects. We demonstrate using simple cases the substantial limitations of the Sheppard correction, and use simple versions of a weak form of the model to establish that there is no real connection between the correction and the model.
Alternative Approaches to Governance in the EU: EU Social Policy and the European Employment Strategy*

Recent actions by the European Union reveal a shift away from traditional, topdown, command and control governance. This can be seen in the structure of traditional tools like directives, as many recent directives, especially in social policymaking, tend to be more open and flexible. But the move to more flexible and participatory approaches can best be seen in areas like the European Employment Strategy (EES), which departs radically from traditional regulatory governance approaches. This article explores the increased use of alternative approaches to governance in the EU by examining the EES as an example of this shift.
The Pill and the College Attainment of American Women and Men

This paper considers the educational consequences of the increased ability of young women to delay childbearing as a result of the birth control pill. In order to identify the effects of the pill, I utilize quasi-experimental variation in U.S. state laws governing access to contraception among female adolescents during the 1960s and 1970s. Inference based on this natural experiment indicates that, by lowering the incidence of early fertility, unconstrained access to the pill increased the enrollment rate of college-age women by almost 5 percentage points. Further, early pill access was associated with a rise in the rate of college completion of approximately 0.9 percentage points among women over the age of thirty. Finally, I analyze the educational outcomes of men in relation to the contraceptive laws governing their likely female partners during adolescence. The results for male college completion suggest that the schooling options for men might also have been constrained by undesired early fertility among their female partners.
Aggregate and Idiosyncratic Risk in a Frictional Labor Market

How are business cycle fluctuations in unemployment and wages affected by the extent to which workers are able to smooth their consumption through asset markets? Can incomplete markets resolve the difficulty search and matching models have in accounting for the high cyclical volatility of unemployment observed in US data? This paper examines a parsimonious equilibrium model of job search with aggregate productivity shocks, where workers face uninsured idiosyncratic unemployment risk. Risk averse entrepreneurs post optimal dynamic contracts to attract risk averse workers, providing them consumption smoothing through wages during employment. Employers cannot insure workers against the idiosyncratic risk of job loss, however. Workers face an extreme form of incomplete markets, leading to a particularly simple representation for the equilibrium as a small system of differential equations. When workers face incomplete markets, cyclical fluctuations in unemployment are amplified, and those in wages dampened. While this brings the model closer to data, the quantitative results show that market incompleteness does not resolve the volatility puzzle.
Probing Protein Structure and Function with an Expanded Genetic Code

A general biosynthetic method has been developed which makes it possible to site-specifically incorporate unnatural amino acids with novel properties into proteins. In this approach the codon encoding the amino acid of interest is replaced with the “blank” nonsense codon UAG by oligonucleotide-directed mutagenesis. A suppressor tRNA that recognizes this codon is generated by run-off transcription and then chemically aminoacylated with the desired unnatural amino acid. Addition of the mutagenized gene and the aminoacylated suppressor tRNA to an in vitro extract capable of supporting protein biosynthesis generates a mutant protein containing the unnatural amino acid at the specified position. This methodology has recently been used to study the stability, specificity, and catalytic properties of a number of proteins. In these studies amino acids and analogues possessing altered hydrogen-bonding, electronic, and steric properties and unique backbone conformations have all been site-specifically incorporated into proteins. In addition, photoactivatable amino acids, isotopically labeled amino acids, and amino acids bearing biophysical probes have been inserted site-specifically. This chemistry increases our ability to carry out detailed physical organic studies on this important class of macromolecules.
PRELIMINARY ANALYSIS OF WISE/NEOWISE 3-BAND CRYOGENIC AND POST-CRYOGENIC OBSERVATIONS OF MAIN BELT ASTEROIDS

We present preliminary diameters and albedos for 13511 Main Belt asteroids (MBAs) that were observed during the 3-Band Cryo phase of the Wide-field Infrared Survey Explorer (WISE; after the outer cryogen tank was exhausted) and as part of the NEOWISE Post-Cryo Survey (after the inner cryogen tank was exhausted). With a reduced or complete loss of sensitivity in the two long wavelength channels of WISE, the uncertainty in our fitted diameters and albedos is increased to ~20% for diameter and ~40% for albedo. Diameter fits using only the 3.4 and 4.6 μm channels are shown to be dependent on the literature optical H absolute magnitudes. These data allow us to increase the number of size estimates for large MBAs which have been identified as members of dynamical families. We present thermal fits for 14 asteroids previously identified as the parents of a dynamical family that were not observed during the fully cryogenic mission.
Robust stability analysis and fuzzy-scheduling control for nonlinear systems subject to actuator saturation

Takagi-Sugeno (TS) fuzzy models can provide an effective representation of complex nonlinear systems in terms of fuzzy sets and fuzzy reasoning applied to a set of linear input-output submodels. In this paper, the TS fuzzy modeling approach is utilized to carry out the stability analysis and control design for nonlinear systems with actuator saturation. The TS fuzzy representation of a nonlinear system subject to actuator saturation is presented. In our TS fuzzy representation, the modeling error is also captured by norm-bounded uncertainties. A set invariance condition for the system in the TS fuzzy representation is first established. Based on this set invariance condition, the problem of estimating the domain of attraction of a TS fuzzy system under a constant state feedback law is formulated and solved as a linear matrix inequality (LMI) optimization problem. By viewing the state feedback gain as an extra free parameter in the LMI optimization problem, we arrive at a method for designing state feedback gain that maximizes the domain of attraction. A fuzzy scheduling control design method is also introduced to further enlarge the domain of attraction. An inverted pendulum is used to show the effectiveness of the proposed fuzzy controller.
Structural aspects of metal–amide complexes

Abstract An exhaustive survey of crystal structure data on simple amides and metal complexes containing monodentate amide ligands has been performed. Statistical analysis of structural features are reported as a function of the degree of alkylation of the amide functional group, the type of metal ion in the amide complex, and the type of binding to the metal ion. Average values are reported for bond lengths, bond angles, and torsional angles. Orientational preferences of the coordinated amide ligand are discussed in terms of M–O–C bond angles and M–O–C–N torsion angles.
On the leverage of high-f/sub T/ transistors for advanced high-speed bipolar circuits

A detailed study on the leverage of high-f/sub T/ transistors for advanced high-speed bipolar circuit applications is presented. It is shown that for the standard ECL (emitter-coupled logic) circuit, the leverage of high f/sub T/ is limited by the passive resistors (emitter-follower resistor and collector load resistor) and wire delay, especially in the low-power regime. For the standard NTL (nonthreshold logic) circuit, the leverage is higher due to its front-end configuration and lower power supply value. As the passive resistors are decoupled from the delay path in various advanced circuits utilizing active-pull-down schemes, the leverage of high F/sub T/ becomes more significant. >
Enhancement of cyclopropanation chemistry in the silver-catalyzed reactions of aryldiazoacetates.

AgSbF6 is an effective catalyst for the reactions of donor/acceptor substituted carbenoids and shows a very different reactivity profile from the traditional rhodium-catalyzed reactions. Most notably, cyclopropanation of sterically hindered alkenes is favorable, and products due to a Wolff rearrangement are not observed. Yields of products obtained are often high (54−96%) with excellent diastereoselectivity (>94% de).
Ion Accelerators as Drivers for Inertial Confinement Fusion

A representation of the state of ion driver technology is shown in Table II. As in any such superficial treatment there are some subjective conclusions but the clear generalization is that the light ion machines have the necessary power and energy but lack rep rate and reliability. The heavy ion drivers, on the other hand, are based on developed accelerator technology which is demonstrated to be of high rep rate and reliability, but is still not at the required energy or power levels.
Thief zone identification through seismic monitoring of a CO 2 flood, weyburn field, Saskatchewan

an estimated 1.4 billion barrels OOIP.5 This paper demonstrates that Time-Lapse and Multi component seismic data analysis is an effective tool for monitoring CO2 injection through the detection of changes in reservoir properties such as porosity, fluid distribution, and fracture density. The monitoring of these changes directly informs the design of the EOR project, thus optimizing field recovery. Evaluation of P-wave Time-Lapse and S-wave data resulted in the following conclusions regarding production in Weyburn field: 1. The Midale reservoir is experiencing a downward loss in CO2 in the west corner of the study area. Shifting the location of the nearby injection well is recommended. 2. Throughout the field, P-wave time-lapse shows that CO2 is largely confined to NW-SE fracture orientation identified after interpretation of the 2000 S-wave data.
Urinary Bladder Carcinogenesis

Urinary bladder carcinogenesis in rodents bears numerous similarities to the diseases in humans. In rats, the process progresses through the morphologic stages of simple hyperplasia, papillary and nodular hyperplasia, papilloma, noninvasive, and invasive carcinoma. In mice, the pathogenesis can be similar or can follow a sequence of marked dysplasia with or without hyperplasia, leading to carcinoma in situ and ultimately to high-grade invasive carcinoma. Although the papillary and nonpapillary diseases appear to be related in rodents and in humans, they are distinct morphologically, biologically, and molecularly. Numerous classes of genotoxic chemicals have been identified as bladder carcinogens in rodents, and some of these have also been identified as carcinogenic in humans, most notably, aromatic amines, nitrosamines, and cyclophosphamide. In contrast, nongenotoxic chemicals appear to be highly specific with respect to species, strain, diet, agent, dose, and mechanism. For some, it is unclear whether the results at high doses in rodents can be extrapolated to low doses or to humans, e.g., chemicals that cause bladder cancer only at high doses related to the formation of calculi. Numerous observations in rodents can assist in identifying possible mechanisms involved for these nongenotoxic chemicals and therefore can be important for a rational evaluation of human risk.
Structure of Thallium Silicate Glass

The structure of quenched and heat-treated thallium silicate glasses containing 29.4 mol% Tl2O was studied by a modified Warren-Mavel X-ray scattering technique. The results, which are essentially independent of the heat treatment used, indicate cation clustering, with an average nearest-neighbor Tl-Tl distance of 3.87 A and a Tl-O distance of 2.60 A. Average coordination numbers for Tl about Tl and O about Tl are 8.4 and ∼ 3, respectively, implying a cluster diameter of ∼ 20 A. These results, with previous results on clustering and density in the Tl2O-SiO2 glass system, indicate that the density and composition of the clusters are 9.4 g/cm3 and 0.6Tl2O-0.4SiO2. The observed break in the composition dependence of conduction activation energy observed in this system is consistent with the proposed structural model.
Investigation of positive and negative modes of nanosecond pulsed discharge in water and electrostriction model of initiation

This work investigates the development of nanosecond pulsed discharges in water ignited with the application of both positive and negative polarity pulses to submerged pin-to-plane electrodes. Optical diagnostics are used to study two main aspects of these discharges: the initiation phase, and the development phase. Nanosecond pulses up to 24 kV with 4 ns rise time, 10 ns duration and 5 ns fall time are used to ignite discharges in a 1.5 mm gap between a copper plate and a tungsten needle with radius of curvature of 25 µm. Fast ICCD imaging is used to trace the discharge development over varying applied pulse amplitudes for both positively and negatively applied pulses to the pin electrode. The discharge is found to progress similar to that of discharges in long gaps—long sparks—in gases, both in structure and development. The more important initiation phase is investigated via schlieren transmission imaging. The region near the tip of the electrode is investigated for slightly under-breakdown conditions, and changes in the liquid's refractive index and density are observed over the duration of the applied pulse. An attempt to explain the results is made based on the electrostriction model of discharge initiation.
A new route to disubstituted cyclopentenones using 2,3-dibromo-1-(phenylsulfonyl)-1-propene as a pivotal reagent

Abstract 2,3-Dibromo-1-(phenylsulfonyl)-1-propene acts as a dielectrophile towards 1,3-diketones and β-ketoesters providing an entry into a variety of 2,3-disubstituted cyclopentenones including cis-jasmone.
Feynman-Diagrammatic Description of the Asymptotics of the Time Evolution Operator in Quantum Mechanics

We describe the "Feynman diagram" approach to nonrelativistic quantum mechanics on R n , with magnetic and potential terms. In particular, for each classical path γ connecting points q0 and q1 in time t, we define a formal power series Vγ (t, q0, q1) in � , given combinatorially by a sum of diagrams that each represent finite-dimensional conver- gent integrals. We prove that exp(Vγ ) satisfies Schr¨ odinger's equation, and explain in what sense the t →0 limit approaches the δ distribution. As such, our construction gives explic- itly the full � →0 asymptotics of the fundamental solution to Schr¨ odinger's equation in terms of solutions to the corresponding classical system. These results justify the heuristic expansion of Feynman's path integral in diagrams. Mathematics Subject Classification (2010). 81T18, 81S40, 81Q15.
X-ray lithography source (SXLS) vacuum system

In 1988 Brookhaven National Laboratory (BNL) was awarded a contract to design and construct a compact light source for X-ray lithography. The contract is for an electron storage ring designed for 690-MeV 500-MeV 500-mA operations. It has a racetrack configuration with a circumference to 8.5 m. The machine is to be constructed in two phases. Phase I (200 MeV, 500 mA) is primarily for low-energy injection studies and incorporates all-room-temperature magnets. For phase II the two room-temperature dipole magnets are replaced with (4 T) superconducting magnets and operation is at 690 MeV. The vacuum system for this machine is described. This vacuum system must satisfy three basic requirements. First, it must provide a dynamic pressure (pressure with stored beam) of 10/sup -9/ torr or better to minimize electron-beam-residual-gas interaction. Second, it must be able to recover from venting to atmosphere, deliberately or accidentally, in a reasonably short time. Third, it should require little operator intervention for normal operation. >
Syntheses and chemistry of porphyrins

Common methods available for the preparation of useful porphyrins from naturally derived heme and by total synthesis from monopyrroles are presented. Such porphyrins can be used for numerous reactivity and structural modification studies of the type which will be presented in minisymposia (including that entitled ‘Syntheses and Chemistry of Porphyrins’) at the First International Conference on Porphyrins and Phthalocyanines (ICPP-1).
A high resolution 14-bit ADC for Gammasphere Project

A system of 110 high-performance ADCs (analog-to-digital converters), required for the Gammasphere Project at the Lawrence Berkeley Laboratory, is described. The ADCs are compact and linear (+or-0.006% integral, +or-0.5% differential), with a conversion deadtime of 6.5 mu s and a channel profile flatness of 50%. The converter is based on a new low-power (0.25 W), low-cost, monolithic high-speed sampling ADC, exhibiting a very high stability and no missing codes over the entire 16-bit range. Differential linearity was achieved by applying the Gatti method, covering a 6-b range. Measured data and methods of testing the ADC are also presented. >
Single-mode fiber-optical power divider: encapsulated etching technique

A straightforward and dependable method to fabricate a low-loss single-mode fiber-to-fiber coupler is reported, in which two twisted single-mode fibers are etched by an HF:NH4F solution in an elongated container with four ports, two ports for fiber passage and the other two ports for etchant filling and draining. Coupling efficiency was controllable anywhere between zero and unity simply by manipulating a threaded cap attached on top of the container. Throughput losses of 2 dB were routinely achieved.
A simple clustering technique to improve QSAR model selection and predictivity: application to a receptor independent 4D-QSAR analysis of cyclic urea derived inhibitors of HIV-1 protease.

A training set of 50 tetrahydropyrimidine-2-one based inhibitors of HIV-1 protease, for which the −log Ki values were measured, was used to construct receptor independent 4D-QSAR models. A novel cl...
Modeling faulted switched reluctance motors using evolutionary neural networks

This paper examines the feasibility of using artificial neural networks (ANNs) and evolutionary algorithms (EAs) to develop discrete time dynamic models for fault-free and faulted switched reluctance motor (SRM) drive systems. SRMs are capable of functioning despite the presence of faults. Faults impart transient changes to machine inductances that are difficult to model analytically. After this transient period, SRMs are capable of functioning at a reduced level of performance. ANNs are applied for their well-known interpolation capabilities for highly nonlinear systems. A dynamical model for an SRM is constructed by feeding values for state variables back to ANN inputs. EAs are employed for their ability to search complex structural and parameter spaces to find good ANN solutions. Furthermore, the ANN structure and training regimen parameters are searched for using EAs. Finally, an analysis of the search is performed, and the resulting model is presented. The results of using the ANN-EA-based model to predict the performance characteristics of prototype SRM drive motion under normal and abnormal operating conditions are presented and verified by comparison to test data.
The limits of Web metadata, and beyond

Abstract The World Wide Web currently has a huge amount of data, with practically no classification information, and this makes it extremely difficult to handle effectively. It has been realized recently that the only feasible way to radically improve the situation is to add to Web objects a metadata classification, to help search engines and Web-based digital libraries to properly classify and structure the information present in the WWW. However, having a few standard metadata sets is insufficient in order to have a fully classified World Wide Web. The first major problem is that it will take some time before a reasonable number of people start using metadata to provide a better Web classification. The second major problem is that no one can guarantee that a majority of the Web objects will be ever properly classified via metadata. In this paper, we address the problem of how to cope with such intrinsic limits of Web metadata, proposing a method that is able to partially solve the above two problems, and showing concrete evidence of its effectiveness. In addition, we examine the important problem of what is the required “critical mass” in the World Wide Web for metadata in order for it to be really useful.
Projected Newton methods and optimization of multicommodity flows

A superlinearly convergent Newton like method for linearly constrained optimization problems is adapted for solution of multicommodity network flow problems of the type arising in communication and transportation networks. We show that the method can be implemented approximately by making use of conjugate gradient iterations without the need to compute explicitly the Hessian matrix. Preliminary computational results suggest that this type of method is capable of yielding highly accurate solutions of nonlinear multicommodity flow problems far more efficiently than any of the methods available at present.
A study on tolerable waiting time: how long are Web users willing to wait?

Web users often face a long waiting time for downloading Web pages. Although various technologies and techniques have been implemented to alleviate the situation and to comfort the impatient users, little research has been done to assess what constitutes an acceptable and tolerable waiting time for Web users. This research reviews the literature on computer response time and users' waiting time for download of Web pages, and assesses Web users' tolerable waiting time in information retrieval. It addresses the following questions through an experimental study: What is the effect of feedback on users' tolerable waiting time? How long are users willing to wait for a Web page to be downloaded before abandoning it? The results from this study suggest that the presence of feedback prolongs Web users' tolerable waiting time and the tolerable waiting time for information retrieval is approximately 2 s.
Special Education Services Received by Students With Autism Spectrum Disorders From Preschool Through High School

Little is known about how special education services received by students with Autism Spectrum Disorders (ASDs) differ by age, disability severity, and demographic characteristics. Using three national data sets, the Pre-Elementary Education Longitudinal Study, the Special Education Elementary Longitudinal Study, and the National Longitudinal Transition Study–2, this study examined the age trends in special education services received by students with ASDs from preschool through high school. Elementary school students with ASDs had higher odds of receiving adaptive physical education, specialized computer software or hardware, and special transportation, but lower odds of receiving learning strategies/study skills support than their preschool peers. Secondary school students had lower odds of receiving speech/language or occupational therapy and of having a behavior management program, but higher odds of receiving mental health or social work services than their elementary school peers. Disability severit...
The association of maternal depressive symptoms with child externalizing problems: the role of maternal support following child sexual abuse.

This study examines the role of abuse-specific maternal support in the association between parent depressive symptoms and child externalizing problems in a sample of children with a history of sexual abuse. In total, 106 mother–child dyads were studied. The association between maternal depressive symptoms and child delinquency behaviors was found to partially operate through abuse-specific maternal support, which was assessed via parent report. Implications of the findings for parenting programs are discussed, and future research directions are considered.
Perceptual Adaptation to Sinewave-Vocoded Speech across Languages.

Listeners rapidly adapt to many forms of degraded speech. What level of information drives this adaptation, however, remains unresolved. The current study exposed listeners to sinewave-vocoded speech in one of three languages, which manipulated the type of information shared between the training languages (German, Mandarin, or English) and the testing language (English) in an audio-visual (AV) or an audio plus still frames modality (A+Stills). Three control groups were included to assess procedural learning effects. After training, listeners’ perception of novel sinewave-vocoded English sentences was tested. Listeners exposed to German-AV materials performed equivalently to listeners exposed to English AV or A+Stills materials and significantly better than two control groups. The Mandarin groups and German-A+Stills group showed an intermediate level of performance. These results suggest that full lexical access is not absolutely necessary for adaptation to degraded speech, but providing AV-training in a language that is similar phonetically to the testing language can facilitate adaptation.
Non-equilibrium in adsorbed polymer layers

High molecular weight polymer solutions have a powerful tendency to deposit adsorbed layers when exposed to even mildly attractive surfaces. The equilibrium properties of these dense interfacial layers have been extensively studied theoretically. A large body of experimental evidence, however, indicates that non-equilibrium effects are dominant whenever monomer–surface sticking energies are somewhat larger than kT, a common case. Polymer relaxation kinetics within the layer are then severely retarded, leading to non-equilibrium layers whose structure and dynamics depend on adsorption kinetics and layer ageing. Here we review experimental and theoretical work exploring these non-equilibrium effects, with emphasis on recent developments. The discussion addresses the structure and dynamics in non-equilibrium polymer layers adsorbed from dilute polymer solutions and from polymer melts and more concentrated solutions. Two distinct classes of behaviour arise, depending on whether physisorption or chemisorption is involved. A given adsorbed chain belonging to the layer has a certain fraction of its monomers bound to the surface, f, and the remainder belonging to loops making bulk excursions. A natural classification scheme for layers adsorbed from solution is the distribution of single-chain f values, P(f), which may hold the key to quantifying the degree of irreversibility in adsorbed polymer layers. Here we calculate P(f) for equilibrium layers; we find its form is very different to the theoretical P(f) for non-equilibrium layers which are predicted to have infinitely many statistical classes of chain. Experimental measurements of P(f) are compared to these theoretical predictions.
Cortical PKC Inhibition Promotes Axonal Regeneration of the Corticospinal Tract and Forelimb Functional Recovery After Cervical Dorsal Spinal Hemisection in Adult Rats

Our previous study shows that conventional protein kinases C (cPKCs) are key signaling mediators that are activated by extracellular inhibitory molecules. Inhibition of cPKC by intrathecal infusion of a cPKC inhibitor, GO6976, into the site of dorsal hemisection (DH) induces regeneration of lesioned dorsal column sensory, but not corticospinal tract (CST), axons. Here, we investigated whether a direct cortical delivery of GO6976 into the soma of corticospinal neurons promotes regeneration of CST and the recovery of forelimb function in rats with cervical spinal cord injuries. We report that cortical delivery of GO6976 reduced injury-induced activation of conventional PKCα and PKCβ1 in CST neurons, promoted regeneration of CST axons through and beyond a cervical DH at C4, formed new synapses on target neurons caudal to the injury, and enhanced forelimb functional recovery in adult rats. When combined with lenti-Chondroitinase ABC treatment, cortical administration of GO6976 promoted even greater CST axonal regeneration and recovery of forelimb function. Thus, this study has demonstrated a novel strategy that can promote anatomical regeneration of damaged CST axons and partial recovery of forelimb function. Importantly, such an effect is critically dependent on the efficient blockage of injury-induced PKC activation in the soma of layer V CST neurons.
A fitness model for scholarly impact analysis

We propose a model to analyze citation growth and influences of fitness (competitiveness) factors in an evolving citation network. Applying the proposed method to modeling citations to papers and scholars in the InfoVis 2004 data, a benchmark collection about a 31-year history of information visualization, leads to findings consistent with citation distributions in general and observations of the domain in particular. Fitness variables based on prior impacts and the time factor have significant influences on citation outcomes. We find considerably large effect sizes from the fitness modeling, which suggest inevitable bias in citation analysis due to these factors. While raw citation scores offer little insight into the growth of InfoVis, normalization of the scores by influences of time and prior fitness offers a reasonable depiction of the field's development. The analysis demonstrates the proposed model's ability to produce results consistent with observed data and to support meaningful comparison of citation scores over time.
Dual-gated volumetric modulated arc therapy

Gated Volumetric Modulated Arc Therapy (VMAT) is an emerging radiation therapy modality for treatment of tumors affected by respiratory motion. However, gating significantly prolongs the treatment time, as delivery is only activated during a single respiratory phase. To enhance the efficiency of gated VMAT delivery, a novel dual-gated VMAT (DG-VMAT) technique, in which delivery is executed at both exhale and inhale phases in a given arc rotation, is developed and experimentally evaluated. Arc delivery at two phases is realized by sequentially interleaving control points consisting of MUs, MLC sequences, and angles of VMAT plans generated at the exhale and inhale phases. Dual-gated delivery is initiated when a respiration gating signal enters the exhale window; when the exhale delivery concludes, the beam turns off and the gantry rolls back to the starting position for the inhale window. The process is then repeated until both inhale and exhale arcs are fully delivered. DG-VMAT plan delivery accuracy was assessed using a pinpoint chamber and diode array phantom undergoing programmed motion. DG-VMAT delivery was experimentally implemented through custom XML scripting in Varian’s TrueBeam™ STx Developer Mode. Relative to single gated delivery at exhale, the treatment time was improved by 95.5% for a sinusoidal breathing pattern. The pinpoint chamber dose measurement agreed with the calculated dose within 0.7%. For the DG-VMAT delivery, 97.5% of the diode array measurements passed the 3%/3 mm gamma criterion. The feasibility of DG-VMAT delivery scheme has been experimentally demonstrated for the first time. By leveraging the stability and natural pauses that occur at end-inspiration and end-exhalation, DG-VMAT provides a practical method for enhancing gated delivery efficiency by up to a factor of two.
Military Procurement and Technology Development

The purpose of this paper is to demonstrate that military and defense related research and procurement have been a major source of commercial technology development across a broad spectrum of industries that account for an important share of United States industrial production. I discuss the development of five general purpose technologies: (1) military and commercial aircraft, (2) nuclear energy and electric power, (3) computers and semiconductors, (4) the Internet, and (5) the space industries. The defense industrial base has become a smaller share of the industrial sector which is itself a declining sector in the U.S. economy. It is doubtful that military and defense related procurement will again become an important source of new general purpose technologies. When the history of U.S. technology development for the next half century is eventually written it will almost certainly be written within the context of slower productivity growth than the relatively high rates that prevailed in the U.S through the 1960's and during the information technology bubble that began in the early 1990's.
HOMOTOPY-PRESERVING MEDIAL AXIS SIMPLIFICATION

We present a novel algorithm to compute a simplified medial axis of a polyhedron. Our simplification algorithm tends to remove unstable features of Blum's medial axis. Moreover, our algorithm preserves the topological structure of the original medial axis and ensures that the simplified medial axis has the same homotopy type as Blum's medial axis. We use the separation angle formed by connecting a point on the medial axis to closest points on the boundary as a measure of the stability of the medial axis at the point. The medial axis is decomposed into its parts that are the sheets, seams and junctions. We present a stability measure of each part of the medial axis based on separation angles and examine the relation between the stability measures of adjacent parts. Our simplification algorithm uses iterative pruning of the parts based on efficient local tests. We have applied the algorithm to compute a simplified medial axis of complex models with tens of thousands of triangles and complex topologies.
Calculation of the coherent synchrotron radiation impedance from a wiggler

Most studies of coherent synchrotron radiation (CSR) have considered only the radiation from independent dipole magnets. However, in the damping rings of future linear colliders and many high luminosity factories, a large fraction of the radiation power will be emitted in damping wigglers. In this paper, the longitudinal wakefield and impedance due to CSR in a wiggler are derived in the limit of a large wiggler parameter K. After an appropriate scaling, the results can be expressed in terms of universal functions, which are independent of K. Analytical asymptotic results are obtained for the wakefield in the limit of large and small distances, and for the impedance in the limit of small and high frequencies.
Stereospecific preparation of (2E, 4Z)-monofluorodienyl esters by the Heck reaction of high E/Z ratio 1-bromo-1-fluorostyrenes

Abstract High E/Z ratio (E/Z>75:25) 1-bromo-1-fluorostyrenes, which were prepared by isomerization of 1-bromo-1-fluorostyrenes (E/Z≈1:1), underwent the Heck reaction with methyl acrylate, and (2E, 4Z)-methyl 5-aryl-4-fluoropenta-2,4-dienoates were successfully isolated. Heck reactions of (Z)-1-bromo-1-fluorostyrenes also occur. However, the products are difficult to separate in a pure form, since they have an obvious tendency to isomerize on a silica gel column.
Design and Synthesis of Isoxazole Containing Bioisosteres of Epibatidine as Potent Nicotinic Acetylcholine Receptor Agonists

An efficient synthesis of isoxazole containing isosteres of epibatidine is described. The synthesis proceeded from N-tert-butoxycarbonyl (Boc)-exo-2-(methoxycarbonyl)-7-azabicyclo[2.2.1]heptane (9). Compound 9 was reacted with the dilithium salt of an appropriately substituted oxime in tetrahydrofuran (THF). Cyclodehydration of the resultant β-keto oxime and deprotection of the N-Boc group in 5N aqueous HCl afforded the isoxazole containing isosteres of epibatidine (6-8). The binding affinities of these compounds were determined at the nicotinic acetylcholine receptor for the displacement of [3H]cytisine. The unsubstituted isoxazole containing isostere (6) showed the lower binding potency compared to the 3'-methylisoxazole isostere (7). Substitution with a phenyl group at the 3'-position of the isoxazole significantly reduced the binding potency. The in vivo toxicological studies of these analogs were also performed. The LD50 of the analogs ranged in the order : Me>H>Ph.
Which Groundwater Remediation Objective is Better: A Realistic One or a Simple One?

One of the first steps in developing an optimal water resources design model is creating appropriate objective functions that represent the primary goals of the design. In many cases, one major objective is minimizing cost. A more realistic cost function, with detailed cost terms, may yield more accurate results but will require more development effort. This research examines the benefits of developing a realistic cost function using two multiobjective groundwater remediation case studies. The results show that realistic cost functions find better solutions than the simplified cost functions, as well as identifying more optimal solutions on the Pareto frontier than the other functions. The realistic cost functions achieved up to 14% improvement in total cost, although the degree of loss in accuracy varies substantially for the two case studies considered in this work and for different parameter settings within each case study. Given the difficulties of predicting which case studies or parameter settings would have significant loss of performance from using simplified cost functions, investments in developing accurate site-specific cost functions appear to be worthwhile.
Accuracy of MSI testing in predicting germline mutations of MSH2 and MLH1: a case study in Bayesian meta-analysis of diagnostic tests without a gold standard

Microsatellite instability (MSI) testing is a common screening procedure used to identify families that may harbor mutations of a mismatch repair (MMR) gene and therefore may be at high risk for hereditary colorectal cancer. A reliable estimate of sensitivity and specificity of MSI for detecting germline mutations of MMR genes is critical in genetic counseling and colorectal cancer prevention. Several studies published results of both MSI and mutation analysis on the same subjects. In this article we perform a meta-analysis of these studies and obtain estimates that can be directly used in counseling and screening. In particular, we estimate the sensitivity of MSI for detecting mutations of MSH2 and MLH1 to be 0.81 (0.73-0.89). Statistically, challenges arise from the following: (a) traditional mutation analysis methods used in these studies cannot be considered a gold standard for the identification of mutations; (b) studies are heterogeneous in both the design and the populations considered; and (c) studies may include different patterns of missing data resulting from partial testing of the populations sampled. We address these challenges in the context of a Bayesian meta-analytic implementation of the Hui-Walter design, tailored to account for various forms of incomplete data. Posterior inference is handled via a Gibbs sampler.
Youth With Disabilities at the Crossroads The Intersection of Vocational Rehabilitation and Disability Benefits for Youth With Disabilities

State vocational rehabilitation (VR) agencies are well positioned to assist youth aged 16 to 24 years with disabilities who are transitioning from school to work. Using Rehabilitation Services Admi...
An analysis of affine coordinates for pairing computation

In this paper we analyze the use of affine coordinates for pairing computation. We observe that in many practical settings, e. g. when implementing optimal ate pairings in high security levels, affine coordinates are faster than using the best currently known formulas for projective coordinates. This observation relies on two known techniques for speeding up field inversions which we analyze in the context of pairing computation. We give detailed performance numbers for a pairing implementation based on these ideas, including timings for base field and extension field arithmetic with relative ratios for inversion-to-multiplication costs, timings for pairings in both affine and projective coordinates, and average timings for multiple pairings and products of pairings.