cssi/SciSciGPT-SciSciNet huggingface dataset:
Lengths of Hawaiian lava flows

Comparison of length, volume, and effusion rate for 87 historic Hawaiian basaltic lava flows shows little support for a direct relationship between flow length and effusion rate. A statistically more significant relationship exists between flow length and total volume of material extruded. Cross-sectional area, effusion rate, and volume all play important roles in governing the emplacement of lava flows in Hawaii; no single factor appears most important. One reason for the observed relationships in Hawaii may be that tube-fed flows, with approximately constant cross-sectional area, advance farther than other types of flows for similar effusion rates and volumes.
Effect of the Capillary Property of Porous Media on the Water Transport Characteristics in a Passive Liquid-Feed DMFC

The porous diffusion medium (DM) used in fuel cells has a complex heterogeneous structure in which both hydrophilic and hydrophobic pores coexist. The capillary flow in such a mixed-wet DM is mainly controlled by the capillary pressure and saturation relation (CPSR). In order to investigate the water transport characteristics in a passive direct methanol fuel cell (DMFC), taking into account the coexistence of the hydrophilic and hydrophobic pores in the DM, we presented the mechanisms of capillary flow in the mixed-wet DM and provided a comprehensive evaluation of the CPSRs used in various existing fuel cell studies. Then, based on a two-dimensional, two-phase, nonisothermal model for the passive DMFC, we investigated the liquid transport phenomena through the mixed-wet DM by employing an experimentally measured mixed-wet CPSR. Moreover, we compared the water transport predicted by the mixed-wet CPSR and the uniform-wet Leverett CPSR for better understanding of the liquid water transport in passive DMFCs. The results show that water transport in the passive DMFC depends greatly on the CPSR of the DM, which demonstrates an urgent need for the accurate CPSRs of the DM used in fuel cells. It is also shown that the dependence of water transport on the CPSRs can be significantly infiuenced by the use of a hydrophobic air filter layer at the cathode.
XMM-Newton Observations Reveal Very High X-ray Luminosity from the Carbon-rich Wolf-Rayet Star WR 48a

We present XMM-Newton observations of the dusty Wolf-Rayet star WR 48a. This is the first detection of this object in X-rays. The XMM-Newton EPIC spectra are heavily absorbed and the presence of numerous strong emission lines indicates a thermal origin of the WR 48a X-ray emission, with dominant temperature components at kTcool � 1 keV and kThot � 3 keV , the hotter component dominating the observed flux. No significant X-ray variability was detected on time scales � 1 day. Although the distance to WR 48a is uncertain, if it is physically associated with the open clusters Danks 1 and 2 at d � 4 kpc, then the resultant X-ray luminosity LX � 10 35 ergs s −1 makes it the most X-ray luminous Wolf-Rayet star in the Galaxy detected so far, after the black-hole candidate Cyg X-3. We assume the following scenarios as the most likely explanation for the X-ray properties of WR 48a: (1) colliding stellar winds in a wide WR+O binary system, or in a hierarchical triple system with non-degenerate stellar components; (2) accretion shocks from the WR 48a wind onto a close companion (possibly a neutron star). More specific information about WR48a and its wind properties will be needed to distinguish between the above possibilities. Subject headings: stars: individual (WR 48a) — stars: Wolf-Rayet — X-rays: stars — shock waves
Late-time Kerr tails revisited

The decay rate of late-time tails in the Kerr spacetime has been the cause of numerous conflicting results, both analytical and numerical. In particular, there is much disagreement on whether the decay rate of an initially pure multipole moment l is according to , where is the least multipole moment whose excitation is not disallowed, or whether the decay rate is according to t−n, where n = n(l). We do careful 2+1D numerical simulations, and explain the various results. In particular, we show that pure multipole outgoing initial data in either Boyer–Lindquist or ingoing Kerr coordinates on the corresponding slices lead to the same late-time tail behavior. We also show that similar initial data specified in terms of the Poisson spherical coordinates lead to the simpler late-time tail. We propose to generalize the rule n = n(l) to subdominant modes, and also study the behavior of non-axisymmetric initial data. We discuss some of the causes for possible errors in 2+1D simulations, demonstrate that our simulations are free of those errors, and argue that some conflicting past results may be attributed to them.
Re-examining the impact of dropping out on criminal and labor outcomes in early adulthood

Abstract This paper shows that while high school dropouts fare far worse on average than otherwise similar high school completers in early adulthood outcomes such as success in the labor market and future criminal activity, there are important differences within this group of dropouts. Notably, those who feel “pulled” out of school (i.e., they say they dropped out of school to work or take care of family) do similarly with respect to labor market and criminal outcomes in their early twenties to individuals with similar pre-dropout characteristics who complete high school. It is only those who feel they are more “pushed” out of school (i.e., they say they drop out for other reasons including expulsion, poor grades, moving, and not liking school) who do substantially worse than otherwise similar high school completers. These results suggest that any detrimental impacts from dropping out of school arise primarily when the drop out does not have a plan for how to use his time after dropping out.
An Analysis of the Effectiveness of Supplemental Instruction: The Problem of Selection Bias and Limited Dependent Variables:

Single equation regression models have been used rather extensively to test the effectiveness of Supplemental Instruction (SI). This approach, however, fails to account for the possibility that SI ...
Tandem Pummerer-Diels-Alder Reaction Sequence. A Novel Cascade Process for the Preparation of 1-Arylnaphthalene Lignans.

The α-thiocarbocation generated from the Pummerer reaction of an o-benzoyl-substituted sulfoxide is intercepted by the adjacent keto group to produce an α-thio isobenzofuran as a transient intermediate which undergoes a subsequent Diels−Alder cycloaddition with added dienophiles. Acid-catalyzed ring-opening of the cycloadduct followed by aromatization gave an arylnaphthalene derivative. With acetylenic dienophiles, the tandem cyclization−cycloaddition sequence provided tetralones which result from a pinacol-type rearrangement of the primary cycloadducts. The versatility of the approach is highlighted through the synthesis of taiwanin C and E and justicidin E. The α-thiocarbocation generated from the Pummerer reaction of benzo[1,3]dioxol-5-yl-[6-[(ethylsulfinyl)methyl]benzo[1,3]dioxol-5-yl)methanone is intercepted by the adjacent keto group to produce an α-thioisobenzofuran as a transient intermediate which undergoes a subsequent Diels−Alder cycloaddition with dimethyl maleate. The initially formed Diels−A...
Detection sensitivity to light offsets is abnormal in glaucomatous visual field

The detection thresholds in the central visual fields of glaucomatous (n = 21), ocular hypertensive (n = 21) and normal (n = 13) individuals were tested with both light decrements (offsets = dark spots) on a cathode ray tube (CRT) and light increments (onsets = bright spots) on a bowl projection perimeter. Both types of stimuli were of equal surface area (Goldmann size IV = 16 mm2) and duration (200 milliseconds) on a 10 cd/m2 background intensity. Computerized threshold testing with light offsets on CRT could document the glaucomatous visual field loss with high accuracy and might indicate early glaucomatous visual field loss missed by the conventional light onset stimuli.
Synthesis of oligonucleotides containing bulky adducts at guanine N2 via the phosphoramidite of O2-triflate-O6-NPE 2′-deoxyxanthosine

Oligodeoxynucleotides bearing bulky adducts at guanine N2 have been prepared by a postoligomerization strategy in which oligonucleotides containing a highly reactive O2-trifluoromethanesulfonyl-O6-(p-nitrophenethyl) 2′-deoxyxanthosine residue were reacted with (±)-10β-amino-7,8,9,10-tetrahydro-benzo[a]pyrene-7β,8α,9α-triol and related compounds.
Application of fuzzy sets to transient analysis of space structures

Abstract An application of fuzzy sets, in conjunction with finite elements, to the transient analysis of a precision-deployable space structure is presented. The structural members are modeled by using beam finite elements, and the structure's latch joint is modeled by using a spring–damper–Coulomb friction element. Two types of transient response simulations are performed: slow transient load–deflection response and transient impulse response. The first simulation is used to evaluate the stiffness and buckling loads at the structure's tip. The second simulation is used to evaluate the structure's natural frequencies, mode shapes and the precision of the final shape. For each simulation the possibility distributions of various response quantities are obtained. Fuzzy sets are used to represent three beam properties, namely: damping coefficient, bending stiffness, and axial stiffness; as well as two joint parameters: Coulomb friction force and damping coefficient. Fuzzy set techniques provide an insight into the range of possible responses associated with the combined selected variations in the system parameters.
Particle identification in the NA49 TPCs

Abstract The NA49 tracking system is comprised of four large-volume Time-Projection-Chambers (TPCs) which measure the charged (and neutral strange) hadrons produced in 160 GeV Pb–Pb nuclear collisions. In typical events with multiplicities of the order of 1500 per event, the TPCs provide momentum and specific ionization information for Particle IDentification (PID) purposes. Two TPCs are located in large gap super-conducting dipole magnets, while two larger chambers sit in field free regions. In all, some 181k channels instrument the chambers. The different environments and conditions within each detector, and the fact that tracks vary in length from 0.5 to 7 m, provide a unique experimental environment in which to carry out PID in the relativistic rise. A 5% resolution in the ionization measurements is realized after extensive calibration, and off-line correction. This allows PID to be carried out on a particle by particle basis rather than in statistical ensembles.
Modeling Arson: An Exercise in Qualitative Model Building

Social scientists are continually confronted with the problem of formulating models which describe how individuals make choices among alternative courses of action with uncertain consequences. Economists have developed a class of models which seem to deal particularly well with problems of this type. These models employ the ``expected utility theorem'' of von Neumann and Morgenstern and, for reasons brought out in the paper, are generally qualitative in nature. Since the approach to modeling human behavior adopted by non-economists is generally very different from that of economists, in this paper we present a rather detailed example of the role of the expected utility theorem in qualitative model building. Specifically, we model an arsonist's decision as to the amount of time to allocate to arson and related activities and examine the responsiveness of this time allocation to changes in various policy parameters. Both the activity modeled and the method of presentation are intended to provide an introduction to the scope and power of the expected utility theorem in modeling situations of ``choice under uncertainty.''
An Elementary Approach to Weight Multiplicities in Bivariate Irreducible Representations of Sp(2r)

By bivariate irreducible representations of Sp(2r), we mean irreducible representations with highest weights containing at most two nonzero entries, using the usual identification of dominant weights for complex symplectic Lie algebras and their corresponding Lie groups as r-tuples in decreasing non-negative integers. This paper has two aims. The first aim is to provide a formula for the weight multiplicities of said representations, which is easily computable. The second aim is to present these weight multiplicities using elementary means. The formula for these weight multiplicities is derived using basic multiliear algebra and combinatorial arguments through explicit descriptions of weight vectors.
Development of the Downhole Dynamometer Database

The Downhole Dynamometer Database is a compilation of test data collected with a set of five downhole tools built by Albert Engineering under contract to Sandia National Laboratories. The downhole dynamometer tools are memory tools deployed in the sucker rod string with sensors to measure pressure, temperature, load, and acceleration. The acceleration data is processed to yield position, so that a load vs. position dynagraph can be generated using data collected downhole. With five tools in the hole at one time, all measured data and computed dynagraphs from five different positions in the rod string are available. The purpose of the Database is to provide industry with a complete and high quality measurement of downhole sucker rod pumping dynamics. To facilitate use of the database, Sandia has developed a Microsoft Windows-based interface that functions as a visualizer and browser to the more than 40 MBytes of data. The interface also includes a data export feature to allow users to extract data from the database for use in their own programs. This paper includes a description of the downhole dynamometer tools, data collection program, database content, and a few illustrations of the data contained in the downhole dynamometer database.
The Influence of Neighboring Blade Rows on the Unsteady Aerodynamic Response of Cascades

In this paper, we present an analysis of the unsteady aerodynamic response of cascades due to incident gusts (the forced response problem) or blade vibration (the flutter problem) when the cascade is part of a multistage fan, compressor, or turbine. Most current unsteady aerodynamic models assume the cascade to be isolated in an infinitely long duct. This assumption, however, neglects the potentially important influence ofneighboring blade rows. We present an elegant and computationally efficient method to model these neighboring blade row effects. In the present method, we model the unsteady aerodynamic response due to so-called spinning modes (pressure and vorticity waves), with each mode corresponding to a different circumferential wave number and frequency. Then, for each mode, we compute the reflection and transmission coefficients for each blade row. These coefficients can be obtained from any of the currently available unsteady linearized aerodynamic models of isolated cascades. A set of linear equations is then constructed that couples together the various spinning modes, and the linear equations are solved via LU decomposition. Numerical results are presented for both the gust response and blade vibration problems. To validate our model, we compare our results to other analytical models, and to a multistage vortex lattice model. We show that the effect of neighboring blade rows on the aerodynamic damping of vibrating cascades is significant, but nevertheless can be modeled with a small number of modes.
Sensitivity Analysis of the Conical-Shaped Equivalent Model of a Bolted Joint

In this paper the conical-shaped equivalent model for a bolted joint is considered. In particular the governing equations for this model are made non-dimensional for the purposes of conducting sensitivity analysis. From this work, a plot of the dimensionless spring-rate of the clamped material is generated for all reasonable designs for which the conical-shaped equivalent model applies. The sensitivity analysis is then used to discuss the relative importance of estimating the proper model and design parameters and a maximum percent of uncertainty in the spring-rate calculation is also presented. It is shown in this discussion that the calculations are quite sensitive to a proper estimation of the cone angle la model parameter) and that uncertainty within this calculation can range from 5 to 20%.
Nonlinear dynamics of magnetic islands with curvature and pressure

Curvature and finite pressure are known to have a dramatic influence on linear magnetic tearing stability. An analytic theory of the nonlinear resistive growth of magnetic islands in tokamaks that includes the interchange driving term in presented here. A Grad‐Shafranov equation to describe the magnetohydrodynamic (MHD) equilibrium of thin islands is derived. The resistive evolution of these islands is then obtained. Interchange effects are found to become progressively less important with increasing island width.
A stochastic model of mortality, fertility, and human capital investment

Abstract This paper examines the relationship between fertility and human capital investment and its implications for economic growth, focusing on the effects of declining mortality. Unlike the existing literature, this paper stresses the role of uncertainty about the number of surviving children. If the marginal utility of a surviving child is convex, then there will be a precautionary demand for children. As the mortality rate and thus, uncertainty fall, this demand decreases. Furthermore, lower mortality encourages educational investment in children. The key result is that this empirically observed quality–quantity trade-off is realized only if uncertainty is incorporated into individual's optimization problem.
Ultra-stable matter–wave gyroscopy with counter-rotating vortex superpositions in Bose–Einstein condensates

Matter–wave interferometers are, in principle, orders of magnitude more sensitive than their optical counterparts. Nevertheless, creation of matter–wave currents to achieve such a sensitivity is a ...
Exploratory synthesis in the solid state. Endless wonders.

This article gives an overview of recent developments in three areas of solid state chemistry: (1) The discovery that centered and originally-adventitious interstitial elements Z are essential for the stability of M6X12-type cluster halides of group 3 and 4 metals has led to a large amount of new chemistry through tuning structures and compositions of AnM6(Z)X12Xn phases with the variables Z, x, and n. The corresponding metal-rich group 3 tellurides exhibit novel and more extensive metal aggregation, reflecting a decreased number of anions and valence electrons. (2) Many intrinsically metallic T5M3 phases with a Mn5Si3-type structure are formed by early transition metals T with main-group elements M. Each characteristically reacts with diverse elements (up to 15−20 each) to form stuffed interstitial versions T5M3Z of the same structure. The ranges of Z and some properties are described. Related reactions of hydrogen (often as an impurity) in Mn5Si3-, β-Yb5Sb3-, and Cr5B3-type systems are extensive. Subst...
ON FINITE RANK DEFORMATIONS OF WIGNER MATRICES II: DELOCALIZED PERTURBATIONS

We study the distribution of the outliers in the spectrum of finite rank deformations of Wigner random matrices. We assume that the matrix entries have finite fourth moment and extend the results by Capitaine, Donati-Martin, and Feral for perturbations whose eigenvectors are delocalized.
Symmetry-breaking corrections to heavy meson form-factor relations

Abstract In the heavy quark limit, the form factors for semileptonic and rare radiative B decays into light mesons are related by heavy quark spin symmetry. Here we compute the leading corrections of order Λ/mQ to these symmetry relations, showing also how to include hard gluon effects systematically to any order in αs(mQ). The subleading correction to the form factor relation for B→π can be computed exactly in the soft pion limit. For decays into vector mesons, the matrix elements of two local dimension-4 operators are needed, one of which vanishes in the constituent quark model. A few applications are briefly discussed.
Numerical methods of star formation history measurement and applications to seven dwarf spheroidals

A comprehensive study of the measurement of star formation histories from colour-magnitude diagrams (CMDs) is presented, with an emphasis on a variety of subtle issues involved in the generation of model CMDs and maximum likelihood solution. Among these are the need for a complete sampling of the synthetic CMD, the use of proper statistics for dealing with Poisson-distributed data (and a demonstration of why Χ 2 must not be used), measuring full uncertainties in all reported parameters, quantifying the goodness-of-fit, and questions of binning the CMD and incorporating outside information. Several example star formation history measurements are given. Two examples involve synthetic data, in which the input and recovered parameters can be compared to locate possible flaws in the methodology (none were apparent) and measure the accuracy with which ages, metallicities and star formation rates can be recovered. Solutions of the histories of seven Galactic dwarf spheroidal companions (Carina, Draco, Leo I, Leo II, Sagittarius, Sculptor and Ursa Minor) illustrate the ability to measure star formation histories given a variety of conditions -numbers of stars, complexity of star formation history and amount of foreground contamination. Significant measurements of ancient >8 Gyr star formation are made in all seven galaxies. Sculptor, Draco and Ursa Minor appear entirely ancient, while the other systems show varying amounts of younger stars.
Magnetic field in the end region of the SSC quadrupole magnet

Recent advances in methods of computing magnetic fields have made it possible to study the field in the end region of the SSC (Superconducting Super Collider) quadrupole magnet in detail. The placement of conductor in the straight section, away from the ends, was designed to produce a practically pure quadrupole field in the two-dimensional sense. The ends of the coils were designed to produce a practically pure quadrupole field in the integral sense using a method that ignores the presence of the iron yoke. Subsequently, the effect of the presence of the yoke on the field was analyzed. The authors present the end configuration together with the computed integrated multipole components, local multipole components, and local field components. A comparison with measurements is included. >
Saturn radio emission near 1 MHz

Radio emissions from the direction of Saturn are analyzed which were observed by IMP-6 at 15 frequencies between 375 and 2200 kHz from April 1971 to October 1972. The radio bursts are identified in the IMP-6 data by a phase analysis of the spin-modulated signal from the spacecraft's dipole antenna, and approximately 12 storms are isolated whose occurrence corresponded to times when the spacecraft had an unobstructed view in the direction of Saturn. The spectral character of the radiation is found to be analogous to that of Jupiter, and a power-spectral analysis of the storm occurrence times indicates a weak periodicity for some of the observing frequencies. The Saturnian emission most similar to Jupiter's decametric emission is found to be strongest at 1100 kHz with a bandwidth of about 1000 kHz. A secondary spectral peak may exist at 400 kHz, which is similar to that observed for Earth and Jupiter. The detection of this nonthermal radio emission is shown to be the first direct evidence for the existence of a Saturnian magnetic field containing energetic particles.
Display characteristics and the impact on usability for stereo

Over the past decade, the number of electronic display technologies available to consumers has risen dramatically, and the capabilities of existing technologies have been expanded. This proliferation of choices provides new opportunities for visual stereo presentation, but also new challenges. The methods of implementing stereo on an electronic display, optimized for the original capabilities of the original displays, may no longer be the best choices. Features such as response time, frame rate, aspect ratio, sync timing, pixel registration, and temporal modulation of grayscale and color can strongly influence the process of selecting an optimum presentation format for a given display technology. Display performance issues such as brightness, contrast, flicker, image distortion, defective pixels, and mura are more critical in 3D imagery than in 2D. Susceptibility to burn-in limits the implementation choices for a display that is to be used for both 3D and 2D applications. Resolution and frame rate establish the overall capability for representing depth, and also establish the performance requirements depth, and also establish the performance requirements for the engine providing the 3D material. This paper surveys the capabilities and characteristics of traditional displays such as CRT and LCD panel, and a broad assortment of newer display technologies, including color plasma, field emission, micromirror and other reflective systems, and the general classes of microdisplays. Relevance of display characteristics to various stereo presentation formats is discussed, with description of laboratory experimentation to provide hard numbers. Recommendations are made regarding the stereo formats to be used with various display technologies, and the display technologies to be used with various stereo formats.
Other high-risk factors for young drivers--how graduated licensing does, doesn't, or could address them.

Problem: Young drivers, particularly those who are newly licensed, have a very high crash risk. This paper examines the risk factors underlying their high crash rates and assesses the extent to which existing graduated licensing programs address these risks and whether improvements to these programs should be considered. Method: Review and synthesis of the literature. Results: The elevated risk among young drivers of being in an injury crash is the result of a number of factors found alone or in combination, such as risky driving, alcohol use, seat belt nonuse, driver distraction, fatigue, and vehicle choice. Nighttime and passenger restrictions, adopted widely in the United States, work by keeping drivers out of hazardous situations rather than by addressing risk factors directly. However, the risk factors remain in play in driving situations not specifically restricted by law. Although other graduated licensing components adopted around the world—more stringent exit tests (i.e., you need to pass a test to move to the next stage), hazard perception tests, and restrictions on speed, vehicle power, and roadway access—make sense based on the identified risk factors, they are not yet supported by research. Should research findings warrant it, consideration should be given to providing guidance to parents about how to keep their beginning drivers safe, including information on vehicle choice. Impact on research, practice, and policy: Researchers should continue to monitor and to evaluate innovative approaches to reduce the crash risk of young drivers. The effectiveness of new approaches should be established before adoption on a wider scale takes place.
Average case analysis for tree labelling schemes

We study how to label the vertices of a tree in such a way that we can decide the distance of two vertices in the tree given only their labels. Gavoille et al. proved that for any such distance labelling scheme, the maximum label length is at least 18log^2n-O(logn) bits, where n is the number of vertices in the input tree T. They also gave a separator-based labelling scheme that has the optimal label length @Q(logn@?log(H"n(T))), where H"n(T) is the height of T. We present two distance labelling schemes, namely, the backbone-based scheme and rake-based scheme, which also achieve the optimal label length. The two schemes always perform at least as well as the separator scheme. Furthermore, the rake-based scheme has a much smaller expected label length under certain tree distributions. With these new schemes, we also can find the least common ancestor of any two vertices based on their labels only.
Are a set of microarrays independent of each other

Having observed an m x n matrix X whose rows are possibly correlated, we wish to test the hypothesis that the columns are independent of each other. Our motivation comes from microarray studies, where the rows of X record expression levels for m different genes, often highly correlated, while the columns represent n individual microarrays, presumably obtained independently. The presumption of independence underlies all the familiar permutation, cross-validation, and bootstrap methods for microarray analysis, so it is important to know when independence fails. We develop nonparametric and normal-theory testing methods. The row and column correlations of X interact with each other in a way that complicates test procedures, essentially by reducing the accuracy of the relevant estimators.
Note on the irreducible triangulations of the Klein bottle

We give the complete list of the 29 irreducible triangulations of the Klein bottle. We show how the construction of Lawrencenko and Negami, which listed only 25 such irreducible triangulations, can be modified at two points to produce the 4 additional irreducible triangulations of the Klein bottle.
Endometrial ablation using sidefire laser fiber

Abstract The first successful use of the neodymium:yttrium-aluminum-garnet (ND:YAG) laser to control hypermenorrhea was reported in 1981. Variations on the technique were attempted to improve the amenorrhea rate. Using the Nd:YAG laser with the blanching or nontouch technique seems to result in a better outcome, and higher rate of total amenorrhea than using the dragging technique. Unipolar coagulation attached to a rollerball or rollerbar was also introduced to improve treatment of the sidewalls of the uterus. The unpredictable nature of electrosurgery resulted in varying rates of amenorrhea from as low as 6% and in a subset of patients under 35 years old, to the 70% range in a nonage-adjusted patient population. Due to the report of improved rates of amenorrhea when using the blanching technique and the Nd:YAG laser, a fiber was developed to direct the laser energy at right angles to the axis of the fiber, therefore allowing a total treatment of the entire uterus in a perpendicular fashion. The theoretic benefit of this would be more complete and predictable destruction of the endometrial linling, avoiding fluid overload by coagulating and sealing the vessels and lymphatics, Results in 27 patients in this study seem to support that theory, since 23 patients (86%) experienced total amenorrhea. Mild spotting, requiring no more than a minipad for 3 days, occurred in the other four women. Fluid loss averaged 150 ml with a maximum of 500 ml; six patients had no measurable fluid loss. The age of the patient was not associated with any difference in the final result. The average time of the procedure was 46 minutes, with an average energy use of 89,670 joules. This seems to be a reasonable alternative that offers improved results compared with methods using electrosurgery or the Nd:YAG laser without the SideFire device.
Characteristics of a firm's information environment and the information asymmetry between insiders and outsiders

Abstract We examine how financial statement informativeness, analyst following, and news relate to the information asymmetry between insiders and outsiders. Corporations’ timely disclosures of value relevant information and information collection by outsiders reduce information asymmetry, limiting insiders’ ability to trade profitably on private information. We use the profitability and intensity of insider trades to proxy for information asymmetry. We find that increased analyst following is associated with reduced profitability of insider trades and reduced insider purchases. Financial statement informativeness is negatively associated with the frequency of insider purchases. However, company news, good or bad, is positively associated with insider purchase frequency.
Total synthesis of a gene

The method developed for the total synthesis of a given DNA containing biologically specific sequences consists of the following. The DNA in the double-stranded form is carefully divided into short single-stranded segments with suitable overlaps in the complementary strands. All the segments are chemically synthesized starting with protected nucleosides and mono-nucleotides. The 5′-OH ends of the appropriate oligonucleotides are then phosphorylated with the use of [γ-32P]ATP and polynucleotide kinase. A few to several neighboring oligonucleotides are then allowed to form bihelical complexes in aqueous solution, and the latter are joined end to end by polynucleotide ligase to form covalently linked duplexes. Subsequent head-to-tail joining of the short duplexes leads to the total DNA. The methods are described for the construction of a biologically functional suppressor transfer RNA gene. The total work involved (i) the synthesis of a 126-nucleotide-long bihelical DNA corresponding to a known precursor to the tyrosine suppressor transfer RNA, (ii) the sequencing of the promoter region and the distal region adjoining the C-C-A end, which contained a signal for the processing of the RNA transcript, (iii) total synthesis of the 207 base-pair-long DNA, which included the control elements, as well as the Eco R1 restriction endonu-clease specific sequences at the two ends, and (iv) full characterization by transcription in vitro and amber suppressor activity in vivo of the synthetic gene.
Extreme Elevation on a 2-Manifold

Given a smoothly embedded 2-manifold in ${\Bbb R}^3,$ we define the elevation of a point as the height difference to a canonically defined second point on the same manifold. Our definition is invariant under rigid motions and can be used to define features such as lines of discontinuous or continuous but non-smooth elevation. We give an algorithm for finding points of locally maximum elevation, which we suggest mark cavities and protrusions and are useful in matching shapes as for example in protein docking.
A mechanism for Thawing the credit markets

This paper describes a mechanism designed to induce commercial banks to increase their willingness to extend loans in an economic environment characterized by increased uncertainty and diminished expectations. This mechanism is a new tool for the conduct of monetary policy to combat recessions.
Adiabatic hypercooling of binary melts

A binary melt is hypercooled when it is cooled to a temperature below its solidus. In the isothermal limit planar solidification fronts propagate at a constant velocity determined by the kinetic undercooling and are subject to a long-wavelength morphological instability if speeds fall below a critical value. Here we examine the adiabatic limit where the accumulation of a small latent heat release causes the velocity of the interface to slowly decrease through its critical value. The evolution of the hypercooled interface is governed by a damped Kuramoto-Sivashinsky (dKS) equation with coefficients that vary as the interface decelerates. Using this equation we show that morphological transitions are delayed by an amount that reflects both the time the system spends in a stable state and the magnitude of the damping. For a sufficiently large latent heat of fusion the long-wavelength morphological instability is annihilated. Finally, the adiabatic dKS equation predicts late-stage coarsening of the microstructure with length scales that increase as ${t}^{1/2}.$ In finite systems this coarsening removes the morphological instability.
Induction detection of concealed bulk banknotes

The smuggling of bulk cash across borders is a serious issue that has increased in recent years. In an effort to curb the illegal transport of large numbers of paper bills, a detection scheme has been developed, based on the magnetic characteristics of bank notes. The results show that volumes of paper currency can be detected through common concealing materials such as plastics, cardboard, and fabrics making it a possible potential addition to border security methods. The detection scheme holds the potential of also reducing or eliminating false positives caused by metallic materials found in the vicinity, by observing the stark difference in received signals caused by metal and currency. The detection scheme holds the potential to detect for both the presence and number of concealed bulk notes, while maintaining the ability to reduce false positives caused by metal objects.
Kinetics and mechanism of the reaction of hydroxyl radicals with acetonitrile under atmospheric conditions

The pulsed laser photolysis-pulsed laser induced fluorescence technique has been employed to determine absolute rate coefficients for the reaction OH + CH3CN (1) and its isotopic variants, OH + CD3CN (2), OD + CH3CN (3), and OD + CD3CN (4). Reactions 1 and 2 were studied as a function of pressure and temperature in N2, N2/O2, and He buffer gases. In the absence of O2 all four reactions displayed well-behaved kinetics with exponential OH decays and pseudo-first rate constants which were proportional to substrate concentration. Data obtained in N2 over the range 50-700 Torr at 298 K are consistent with k(sub 1), showing a small pressure dependence. The Arrhenius expression obtained by averaging data at all pressures in k(sub 1)(T) = (1.1(sup +0.5)/(sub -0.3)) x 10(exp -12) exp[(-1130 +/- 90)/T] cu cm /(molecule s). The kinetics of reaction 2 are found to be pressure dependent with k(sub 2) (298 K) increasing from (1.21 +/- 0.12) x 10(exp -14) to (2.16 +/- 0.11) x 10(exp -14) cm(exp 3)/ (molecule s) over the pressure range 50-700 Torr of N2 at 298 K. Data at pressures greater than 600 Torr give k(sub 2)(T) = (9.4((sup +13.4)(sub -5.0))) x 10(exp -13) exp[(-1180 +/- 250)/T] cu cm/(molecule s). The rates of reactions 3 and 4 are found to be independent of pressure over the range 50-700 Torr of N2 with 298 K rate coefficient given by k(sub 3) =(3.18 +/- 0.40) x 10(exp -14) cu cm/(molecule s) and k(sub 4) = (2.25 +/-0.28) x 10(exp -14) cu cm/(molecule s). In the presence of O2 each reaction shows complex (non-pseudo-first-order) kinetic behavior and/or an apparent decrease in the observed rate constant with increasing [O2], indicating the presence of significant OH or OD regeneration. Observation of regeneration of OH in (2) and OD in (3) is indicative of a reaction channel which proceeds via addition followed by reaction of the adduct, or one of its decomposition products, with O2. The observed OH and OD decay profiles have been modeled by using a simple mechanistic scheme to extract kinetic information about the adduct reations with O2 and branching ratios for OH regeneration. A plausible mechanism for OH regeneration in (2) involves OH addition to the nitrogen atom followed by O2 addition to the cyano carbon atom, isomeriazation and decomposition to D2CO + DOCN + OH. Our results suggest that the OH + CH3CN reaction occurs via a complex mechanism involving both bimolecular and termolecular pathways, analogous to the mechanisms for the the important atmospheric reactions of OH with CO and HNO3.
Causes and Explanations: A Structural-Model Approach. Part II: Explanations

AbstractWe propose new definitions of (causal) explanation, using structural equations to model counterfactuals. The definition is based on the notion of actual cause, as defined and motivated in a...
An Agent-Based Model That Relates Investment in Education to Economic Prosperity

This paper describes some experiments with an agent-based model designed to capture the relationship between the investment that a society makes in education in one generation, and the outcome in terms of the health of the society's economy in ensuing generations. The model we use is a multiagent simulation derived from an equation-based model in the economics literature. The equation-based model is used to establish parameterized sets of agent behaviors and environmental characteristics. Agents are divided into three chronological categories: students, adults and pensioners; and each responds to and affects the environment in different ways, in terms of both human and physical capital. We explore the effects of different parameter settings on the education investment of a society and the resulting economic growth.
Ocean-atmosphere climate shift during the mid-to-late Holocene transition

Article history: Climate records of the mid-to-late Holocene transition, between 3-4 thousand years before present (ka), often exhibit a rapid change in response to the gradual change in orbital insolation. Here we investigate North Atlantic Central Water circulation as a possible mechanism regulating the latitudinal temperature gradient (LTG), which, in turn, amplifies climate sensitivity to small changes in solar irradiance. Through this mechanism, sharp climate events and transitions are the result of a positive feedback process that propagates and amplifies climate events in the North Atlantic region. We explore these linkages using an intermediate water temperature record reconstructed from Mg/Ca measurements of benthic foraminifera (Hyalinea balthica )f rom as ediment core off NW Africa (889 md epth) between 0t o 5.5 ka. Our results show that Eastern North Atlantic Central Waters (ENACW) cooled by ∼1 ◦ ±0.7 ◦ Ca nd densities decreased by σθ = 0.4 ± 0. 2b etween 3.3 and 2.6 ka. This shift in ENACW hydrography illustrates at ransition towards enhanced mid-latitude atmospheric circulation after 2.7 ka in particular during cold events of the late-Holocene. The presented records demonstrate the important role of ENACW circulation in propagating the climate signatures of the LTG by reducing the meridional heat transfer from high to low latitudes during the transition from the Holocene Thermal Maximum to the late-Holocene. In addition, the dynamic response of ENACW circulation to the gradual climate forcing of LTGs provides a prime example of an amplifying climate feedback mechanism. Published by Elsevier B.V.
Spray cooling of power electronics at cryogenic temperatures

The operation of power electronics at liquid nitrogen temperature (LNT) is a very attractive possibility. However, a high heat flux (over 1.0 x 10 6 W/m2) cooling technique, like spray cooling, will have to be used to realize all the advantages of low-temperature operation. This study details the results from experiments conducted to study the heat transfer characteristics during spray cooling with liquid nitrogen. Four different nozzles at various pressures were used to study the variation in spray cooling heat transfer at LNT. The effect of nozzle and flow rate on the critical heat flux and overall heat transfer characteristics are presented. Heat fluxes close to 1.7 x 10 6 W/m2 were realized at temperatures below 100 K. The mass flow rate range was from 6.1 x 10 4 kg/h m2 to 3.2 x 10 s kg/h m2. Nomenclature q" = heat flux, W/m2 rsat = saturation temperature, K Tw = surface temperature, K
Learning Isometric Separation Maps

Maximum Variance Unfolding (MVU) and its variants have been very successful in embedding data-manifolds in lower dimensional spaces, often revealing the true intrinsic dimension. In this paper we show how to also incorporate supervised class information into an MVU-like method without breaking its convexity. We call this method the Isometric Separation Map and we show that the resulting kernel matrix can be used as a binary/multiclass Support Vector Machine-like method in a semi-supervised (transductive) framework. We also show that the method always finds a kernelmatrix that linearly separates the training data exactly without projecting them in infinite dimensional spaces. In traditional SVMs we choose a kernel and hope that the data become linearly separable in the kernel space. In this paper we show how the hyperplane can be chosen ad-hoc and the kernel is trained so that data are always linearly separable. Comparisons with Large Margin SVMs show comparable performance.
An Interactionist Perspective on the Socioeconomic Context of Human Development

This article addresses the relationship between socioeconomic status (SES), family processes, and human development. The topic is framed as part of the general issue of health disparities, which involves the oft-observed positive relationship between SES and the cognitive, social, emotional, and physical well-being of adults and children. A review of recent research and theory identifies three general theoretical approaches that provide possible explanations for the association between SES and individual development: the social causation, social selection, and interactionist perspectives. Empirical evidence demonstrates support for the social causation view that SES affects families and the development of children in terms of both family stress processes (the family stress model) and family investments in children (the family investment model). However, there also is empirical support for the social selection argument that individual characteristics lead to differences in SES. Especially important, recent research is consistent with an interactionist approach, which proposes a dynamic relationship between SES and developmental change over time. Drawing on the combined set of research findings, the article concludes with the description of an interactionist model that serves as a heuristic for future studies of the links among SES, parenting behaviors, and child development.
The CFAR adaptive subspace detector is a scale-invariant GLRT

The constant false alarm rate (CFAR) matched subspace detector (CFAR MSD) is the uniformly most-powerful-invariant test and the generalized likelihood ratio test (GLRT) for detecting a target signal in noise whose covariance structure is known but whose level is unknown. Previously, the CFAR adaptive subspace detector (CFAR ASD), or adaptive coherence estimator (ACE), was proposed for detecting a target signal in noise whose covariance structure and level are both unknown and whose covariance structure is estimated with a sample covariance matrix based on training data. We show here that the CFAR ASD is GLRT when the test measurement is not constrained to have the same noise level as the training data, As a consequence, this GLRT is invariant to a more general scaling condition on the test and training data than the well-known GLRT of Kelly (1986).
Overhead infrared vehicle sensor for traffic control

An experimental infrared optical system has been designed to detect and monitor vehicular road traffic. The system was developed and tested in the laboratory using infrared laser sources and detectors in conjunction with computerized signal processing and correlation techniques. Preliminary road tests confirm the system's capability to detect and monitor vehicular road traffic. The test results indicate that a product based on the technology developed may be cost effective, weather resistant, and have the potential for more sophisticated applications, including vehicle speed measurement and length classification.
Order And Civil Liberties: A Complex Role For The Police†

This article expresses the views of a man well qualified to discuss the vital topic of law enforcement and its relation to minority groups. In 1961 the residents and newly-elected city administration of Detroit felt that there was a real possibility of a major riot similar to the one in 1943. Mayor Cavanagh therefore persuaded Judge Edwards to leave his position as a Justice of the Supreme Court of Michigan and assume the responsibilities of Police Commissioner of Detroit.