cssi/SciSciGPT-SciSciNet huggingface dataset:
Variation of the elastic moduli at the superconducting transition

Using an ultrasonic technique capable of measuring changes in the elastic moduli as small as one part in 107, the small modulus changes associated with then ormal-to-superconducting transition have been measured as a function of both temperature and magnetic field. Single-crystal specimens of the cubic metals Pb, V, Nb and Ta were used and all their elastic moduli measured so that changes in the bulk modulus and Debye θ could be computed. The results showed that changes in the zeropoint energy of the lattice can be far from negligible. Furthermore, the shear moduli are the most changed by the appearance of superconductivity.
A New Approach to Flow Simulation in Highly Heterogeneous Porous Media

In this paper, applications are presented for a new numerical method - operator splittings on multiple grids (OSMG) - devised for simulations in heterogeneous porous media. A coarse-grid, finite-element pressure solver is interfaced with a fine-grid timestepping scheme. The CPU time for the pressure solver is greatly reduced and concentration fronts have minimal numerical dispersion.
Highly Stereoselective Saucy−Marbet Rearrangement Using Chiral Ynamides. Synthesis of Highly Substituted Chiral Homoallenyl Alcohols

A highly stereoselective Saucy−Marbet rearrangement using chiral ynamides and propargyl alcohols is described here. This rearrangement can be catalyzed by para-nitrobenzenesulfonic acid leading to ...
Soot and Ash Deposition Characteristics at the Catalyst-Substrate Interface and Intra-Layer Interactions in Aged Diesel Particulate Filters Illustrated using Focused Ion Beam (FIB) Milling

The accumulation of soot and lubrication-derived ash particles in a diesel particulate filter (DPF) increases exhaust flow restriction and negatively impacts engine efficiency. Previous studies have described the macroscopic phenomenon and general effects of soot and ash accumulation on filter pressure drop. In order to enhance the fundamental understanding, this study utilized a novel apparatus, that of a dual beam scanning electron microscope (SEM) and focused ion beam (FIB), to investigate microscopic details of soot and ash accumulation in the DPF. Specifically, FIB provides a minimally invasive technique to analyze the interactions between the soot, ash, catalyst/washcoat, and DPF substrate with a high degree of measurement resolution. The FIB utilizes a gallium liquid metal ion source which produces Ga+ ions of sufficient momentum to directionally mill away material from the soot, ash, and substrate layers on a nm-μm scale. As the FIB cuts into the sample, uncovering intra-layer details, the coupled high resolution SEM imaging and energy dispersive x-ray (EDX) analysis provide both morphological and chemical data. This tool was applied to investigate soot and ash accumulation in the DPF, with a specific focus on characterizing interactions between the soot/ash/DPF interfaces, such as soot penetration into the ash layer, as well as soot and ash accumulation in the DPF surface pores. In particular, ash and soot particle size, layer pore structure, and the extent of penetration or intra-layer mixing, are all parameters directly impacting DPF pressure drop, which may be quantified using this technique. The work in this study leveraged existing databases of aged DPFs containing various levels of soot and ash, originating from field trials and controlled laboratory testing. Results obtained with this technique provide a fresh and complementary perspective, as well as additional details useful to understand the macroscopic observations of the combined ash and soot effects on diesel particulate filter pressure drop.
THERMAL EMISSION AS A TEST FOR HIDDEN NUCLEI IN NEARBY RADIO GALAXIES

The clear sign of a hidden quasar inside a radio galaxy is the appearance of quasar spectral features in its polarized (scattered) light. However, that observational test requires suitably placed scattering material to act as a mirror, allowing us to see the nuclear light. A rather robust and more general test for a hidden quasar is to look for the predicted high mid-IR luminosity from the nuclear obscuring matter. The nuclear waste heat is detected and well isolated in the nearest narrow-line radio galaxy, Cen A. This confirms other indications that Cen A does contain a modest quasar-like nucleus. However, we show here that M87 does not: at high spatial resolution, the mid-IR nucleus is seen to be very weak and consistent with simple synchrotron emission from the base of the radio jet. This fairly robustly establishes that there are real narrow-line radio galaxies, without the putative accretion power and with essentially all the luminosity in kinetic form. Next, we show the intriguing morphology of Cygnus A, where all of the mid-IR emission is consistent with reprocessing by the hidden quasar known to exist from spectropolarimetry and other evidence.
Electric-Field-Induced Lamellar Structures in Magnetic Fluids - A 2D Diffusion Model

A lamellar pattern can form in a thin magnetic fluid layer when the applied electric field is above a critical value. A 2D simulation is performed to study the field-induced phase separation and the pattern by using the mass continuity equation. The simulation produces the similar structure in field but does not match the experimental growth law.
Materials by Design

To design a material is to try to meet a material user9s need. A good place to start is with property cross-plots that graphically define property-performance relations.
DLG1 influences distal ureter maturation via a non-epithelial cell autonomous mechanism involving reduced retinoic acid signaling, Ret expression, and apoptosis.

The absence of Discs-large 1 (DLG1), the mouse ortholog of the Drosophila discs-large tumor suppressor, results in congenital hydronephrosis characterized by urinary tract abnormalities, reduced ureteric bud branching, and delayed disconnection of the ureter from the common nephric duct (CND). To define the specific cellular requirements for Dlg1 expression during urogenital development, we used a floxed Dlg1 allele and Pax2-Cre, Pax3-Cre, Six2-Cre, and HoxB7-Cre transgenes to generate cell type-restricted Dlg1 mutants. In addition, we used RetGFP knockin and retinoic acid response element-lacZ transgenic mice to determine the effects of Dlg1 mutation on the respective morphogenetic signaling pathways. Mutation of Dlg1 in urothelium and collecting ducts (via HoxB7-Cre or Pax2-Cre) and in nephron precursors (via Pax2-Cre and Six2-Cre) resulted in no apparent abnormalities in ureteric bud branching or in distal ureter maturation, and no hydronephrosis. Mutation in nephrons, ureteric smooth muscle, and mesenchyme surrounding the lower urinary tract (via the Pax3-Cre transgene) resulted in congenital hydronephrosis accompanied by reduced branching, abnormal distal ureter maturation and insertion, and smooth muscle orientation defects, phenotypes very similar to those in Dlg1 null mice. Dlg1 null mice showed reduced Ret expression and apoptosis during ureter maturation and evidence of reduced retinoic acid signaling in the kidney. Taken together, these results suggest that Dlg1 expression in ureter and CND-associated mesenchymal cells is essential for ensuring distal ureter maturation by facilitating retinoic acid signaling, Ret expression, and apoptosis of the urothelium.
Bringing the Welfare State Back In: The Promise (and Perils) of the New Social Welfare History

The welfare state—the complex of policies that, in one form or another, all rich democracies have adopted to ameliorate destitution and provide valued social goods and services—is an increasingly central subject in the study of American history and politics. The past decade has unleashed a veritable tidal wave of books on the topic, including, from historians, Alice Kessler-Harris's In Pursuit of Equity and Michael Katz's The Price of Citizenship, and, from political scientists, Robert Lieberman's Shifting the Color Line and Peter Swenson's Capitalists Against Markets. Journals ranging from the American Historical Review to Political Science Quarterly (and, with less regularity, even the American Political Science Review) now routinely feature analyses of U.S. social policy. And going back just a few years more, the early 1990s saw the publication of several influential works on the subject, notably Paul Pierson's Dismantling the Welfare State? and Theda Skocpol's Protecting Soldiers and Mothers, each of which won major book prizes in political science. If any moment deserves to be seen as a heady time for writing on the American welfare state, this is it.
The German executive in the U.S. work and social environment: Exploring role demands

Abstract German executives residing in the U.S. were examined on dimensions of satisfaction and adjustment to expatriation. Reported cultural skill, prior experience living abroad, business problems encountered in the U.S., and attributions of German and U.S. staff were studied in relation to satisfaction living abroad, career development satisfaction related to expatriation, and work satisfaction. A comparison group of 21 U.S. executives living in Japan was included in the analysis. Results indicated that German executives reported fewer business-related barriers and greater cultural skill than did the American executives. However, there was no significant difference in general satisfaction found between the two groups; for the German executives, expatriate satisfaction was predicted by greater career satisfaction and lower ratings for identification with the parent company. For both groups, the level of cultural skill was significantly related to satisfaction living abroad.
Holomorphic projection and duality for domains in complex projective space

We show that the efficiency of a natural pairing between certain projectively invariant Hardy spaces on dual strongly C-linearly convex real hypersurfaces in complex projective space is measured by the norm of the corresponding Leray transform.
Does mathematics have elements

For Empedocles, a little over 2400 years ago, there were four chemical elements, fire, water, earth, and air, and they were continually brought together and torn apart by two opposing forces, harmony and discord. For Aristotle, a hundred years later, two binary classification schemes took the place of one: instead of harmony-discord, he had wet-dry and hot-cold. The serious alchemists of the middle ages found that nature was even more complicated than that; they classified matter by its luster, heaviness, combustilibity, solubility, and so on. Boyle, in the 1600's, offered a definition similar to that of a prime number – an element is a substance from which other substances can be made but which cannot be separated into different substances – and analytical chemistry was off and running. A hundred years later Lavoisier (inspired in part by Newton's insight into the paramount importance of weight) could formulate a modified definition that led for the first time to quantitative tables of chemical elements similar to our modern ones.
Dual Resonance Theory with Nonlinear Trajectories

A dual resonance model with nonlinear trajectories which includes the Veneziano model as a limiting case is discussed. Rules are given for constructing the $N$-point function in such a model, and an explicit expression for the $N$-point planar tree graph is derived. A conjectured rule for loop diagrams is also presented. Representations of four-point-function satellite terms which admit straightforward generalization to the $N$-point function are derived.
China's ministry of state security: Coming of age in the international arena

(1993). China's ministry of state security: Coming of age in the international arena. Intelligence and National Security: Vol. 8, No. 1, pp. 23-43.
A study of eddy-current effects in the structure of the westinghouse LCT coil

One of the six 2.5- × 3.5-m-bore 8-T superconducting magnets of the international Large Coil Task (LCT) was designed and fabricated by Westinghouse Electric Corporation with the oversight of Oak Ridge National Laboratory. This coil, designated WH, has a mechanical structure composed of a stack of aluminum plate segments held together with stainless throughbolts. When the magnetic flux through the coil is changed, voltage is induced in the structure, and to avoid excessive currents the design provided low-voltage insulation between plate segments. However, during construction it appeared that this anodizing layer may have been breached extensively. Electrical tests on delivery confirmed this, and supplemental instrumentation was added to the structure before the coil was installed in the test facility. The shorting raised concerns about increased refrigeration load, local overheating, and a change in dump characteristics. After installation, current ramps to 5 A showed magnetic diffusion time constants of 1.5 s at room temperature and 3.0 s at 20 K, an order of magnitude larger than for the other LCT coils. These latter coils have structural cases of stainless steel, which has an electrical resistivity 17 times that of the 2219-T87 aluminum used in the WH coil. In tests at operating currents, temporal values of voltage, current, temperature, and energy distribution during ramp and dump agree with those values calculated on the basis that the aluminum structure is solid, and are quite different from values calculated without considering shorting. On dump, the coil is partially self-protecting, but 23% of the initial stored energy is deposited in the structure at cryogenic temperature. The various effects of the shorting are apparently tolerable for testing in the International Fusion Superconducting Magnet Test Facility (IFSMTF). For other cases, the coil designer should carefully consider if and how the structure should be electrically segmented.
Matrix variational calculations of electron-atom scattering

Abstract The continuum variational method of Kohn has been developed into a practical computational method in electron-atom scattering theory. This algebraic or matrix variational formalism is reviewed, with emphasis on the computational procedures necessary for applications to inelastic scattering processes. The matrix variational method has been used to obtain quantitative theoretical results relevant to recent experimental research. Examples of such applications will be given.
The Promiscuous Nature of Stars in Clusters

The recent availability of special-purpose computers designed for calculating gravitational interactions of N bodies at extremely high speed has provided the means to model globular clusters on a star-by-star basis for the first time. By endeavoring to make the N-body codes that operate on these machines as realistic as possible, the addition of stellar evolution being one example, we are learning much about the interaction between the star cluster itself and the stars it contains. A fascinating aspect of this research is the ability to follow the orbits of individual stars in detail and to document the formation of observed exotic systems. This has revealed that many stars within a star cluster lead wildly promiscuous lives, interacting often intimately and in rapid succession with a variety of neighbors.
Numerical simulation of inclined chute flows of monodisperse, inelastic, frictional spheres

Abstract Molecular-dynamics-like simulations are utilized to map regions of flow parameter space where steady flows occur for monodisperse assemblies of inelastic, frictional spheres, flowing down frictional, inclined planar surfaces. The trajectory-following technique utilizes nearly-rigid particles interacting via contact forces and gravity. Energy losses in the simulations occur only via displacement-dependent hysteretic loading/unloading paths and sliding friction. Initial scoping calculations are examining flows on an incline tilted 17° from the horizontal, determining the boundaries of various flow regimes. Assemblies of inelastic spheres with interparticle friction coefficients less than the tangent of the inclination angle accelerate unboundedly. Those with friction coefficients somewhat greater than the tangent of the inclination angle develop steady velocity and density profiles for a variety of flow depths but result in arrested flow for coefficients of friction greatly exceeding the inclination angle tangent (e.g., by more than a factor of 2). Conversely, a significant range of inclination angles that will result in steady flows for a given set of assembly properties, is expected to exist.
On the two-phase Stefan problem with interfacial energy and entropy

Abstract : The classical Stefan theory for the melting of a solid or the freezing of a liquid is too simplistic to describe phenomena such as supercooling, in which a liquid supports temperatures below its freezing point, or superheating, the analog for solids, or dendritic growth, in which simple shapes evolve to complicated tree-like structures. This paper develops a general theory for two-phase phenomena of this type. It develops partial differential equations satisfied in the phase regions and free-boundary conditions satisfied on the interface between phases, and gives arguments which indicate that the resulting boundary-value problems predict the formation of dendrites. Keywords: Equilibrium; Liapunoo functions; Mathematical physics.
Vortex excitation of metal bellows

Vibratory amplitudes and stress levels from metal bellows flow induced vibrations, discussing damping and acoustical resonances effects
Simulation of the dynamics of air and water pollution

Simulation of the dynamics of air and water pollution rests firmly on the diffusion equation, which in simplest form is known as Fick's second law. The problem of dispersion of solutes and suspensoids is much older than the pollution crisis, and in fact the development of the first useful solutions of the diffusion equation came in response to a need for predicting the spread of poison gas.
Intramolecular cyclization of ethyl ω-(5-amino-4-aminocarbonylimidazol-1-yl)carboxylates

Cyclisations intramoleculaires avec le formiate d'ethyle d'amino-5 carbamoyl-4 imidazoleacetate-1, -propionate-1 et -butyrate-1 d'ethyle: les deux derniers composes conduisent aux amides d'acides tetrahydro-1,2,3,4 oxo-2 imidazo [1,5-a] pyrimidinecarboxylique-8 et -diazepine-1,3 carboxylique-9
String theory and quark confinement

Abstract This article is based on a talk given at the “Strings '97” conference. It discusses the search for the universality class of confining strings. The key ingredients include the loop equations, the zigzag symmetry, the non-linear renormalization group. Some new tests for the equivalence between gauge fields and strings are proposed.
Synthesis of aza-C-galacto disaccharides from C1-substituted galactals

C1-substituted galactals are transformed via the double reductive amination on their 1,5-diketone derivatives, to aza-β-C-galacto-disaccharides.
Relativistic Beaming and Flux Variability in Active Galactic Nuclei

We discuss the impact of special relativistic effects on the observed light curves and variability duty cycles of radio-loud active galactic nuclei (AGNs). We model the properties of AGN light curves at radio wavelengths using a shot-noise process in which the occurrence of major flaring events in a relativistic jet is governed by Poisson statistics. We show that flaring sources whose radiation is highly beamed toward us are able to reach very high flux levels, but will in fact spend most of their time in relatively low flaring states. This is primarily due to relativistic Doppler contraction of flaring timescales in the observer frame. The fact that highly beamed AGNs are not observed to return to a steady state quiescent level between flares implies that their weakly beamed counterparts should have highly stable flux densities that result from a superposition of many long-term, low-amplitude flares. The "apparent" quiescent flux levels of these weakly beamed AGNs (identified in most unified models as radio galaxies) will be significantly higher than their "true" quiescent (i.e., nonflaring) flux levels. We have also performed Monte Carlo simulations to examine how relativistic beaming and source variability bias the selection statistics of flat-spectrum AGN samples. We find that in the case of the Caltech-Jodrell Flat-Spectrum Survey, the predicted orientation bias toward jets seen end-on is weakened if the parent population is variable, because highly beamed sources have a stronger tendency to be found in low flaring states. This effect is small, however, because highly beamed sources are relatively rare, and in most cases their flux densities will be boosted sufficiently above the survey limit that they will be selected regardless of their flaring level. We find that, for larger flat-spectrum AGN surveys with fainter flux density cutoffs, variability should not be an appreciable source of selection bias.
The effect of inhaled steroids on the linear growth of children with asthma: a meta-analysis.

Objective. To determine whether inhaled steroid therapy causes delayed linear growth in children with asthma. Data Sources. Medline (1966–1998), Embase (1980–1998), and Cinahl (1982–1998) databases and bibliographies of included studies were searched for randomized, controlled trials of inhaled steroid therapy in children with asthma that evaluated linear growth. Study Selection. Studies were included if they met the following criteria: subjects 0 to 18 years of age with the clinical diagnosis of asthma; subjects randomized to inhaled beclomethasone, budesonide, flunisolide, fluticasone, or triamcinolone versus a nonsteroidal inhaled control for a minimum of 3 months; single- or double-blind; and outcome convertible to linear growth velocity. English- and non–English-language trials were included. Data Extraction. Data were extracted using a priori guidelines. Methodologic quality was assessed independently by both authors. Outcome was extracted as linear growth velocity. Results. Included trials were subgrouped by inhaled steroid. The beclomethasone subgroup, with 4 studies and 450 subjects, showed a decrease in linear growth velocity of 1.51 cm/year (95% confidence interval: 1.15,1.87). The fluticasone subgroup, with 1 study and 183 subjects, showed a decrease in linear growth velocity of .43 cm/year (95% confidence interval: .01,.85). Sensitivity analysis in the beclomethasone subgroup, which evaluated study quality, mode of medication delivery, control medication, and statistical model, showed similar results. Conclusions. This meta-analysis suggests that moderate doses of beclomethasone and fluticasone in children with mild to moderate asthma cause a decrease in linear growth velocity of 1.51 cm/year and .43 cm/year, respectively. The effects of inhaled steroids when given for >54 weeks, or on final adult height, remain unknown.
Interaction of an oscillating vortex with a turbulent boundary layer

The effects on mean flow and turbulence caused by meander of a vortex embedded in a two-dimensional boundary layer were investigated experimentally by driving a forced lateral oscillation of the vortex generator. Upstream, the vorticity contours without forcing were found to be round. The forced vortex generator oscillation caused a flattening of the time-averaged vorticity contours and changes in some of the Reynolds stresses. The results indicate that the unforced vortex did not meander significantly upstream, and that the effects of meander can be understood qualitatively from production of Reynolds stresses by the forced motion acting with the exiting three-dimensional velocity field. Farther downstream, the observed differences in the mean vorticity and Reynolds stresses caused by forcing were smaller, mainly because the vortex was substantially diffused at this station, resulting in smaller mean velocity gradients.
Complex entangling surfaces for AdS and Lifshitz black holes

We discuss the possible relevance of complex codimension-two extremal surfaces to the Ryu?Takayanagi holographic entanglement proposal and its covariant Hubeny?Rangamani?Takayanagi generalization. Such surfaces live in a complexified bulk spacetime defined by analytic continuation. We identify surfaces of this type for BTZ, Schwarzschild?AdS, and Schwarzschild?Lifshitz planar black holes. Since the dual CFT interpretation for the imaginary part of their areas is unclear, we focus on a straw man proposal relating CFT entropy to the real part of the area alone. For Schwarzschild?AdS and Schwarzschild?Lifshitz, we identify families where the real part of the area agrees with qualitative physical expectations for the time-dependence of the appropriate CFT entropy and, in addition, where it is smaller than the area of corresponding real extremal surfaces. It is thus plausible that the CFT entropy is controlled by these complex extremal surfaces.
Phenotypic Plasticity and Epithelial-Mesenchymal Transitions in Cancer - and Normal Stem Cells?

Cancer stem cells (CSCs) are similar to normal stem cells in their ability to self-renew and to generate large populations of more differentiated descendants. In contrast to the hierarchical organization that is presumed to be the prevalent mode of normal tissue homeostasis, phenotypic plasticity allows cancer cells to dynamically enter into and exit from stem-cell states. The epithelial-mesenchymal transition (EMT) has been closely associated with the acquisition of both invasive and stem-cell properties in cancer cells. Thereby, EMT programs emerge as important regulators of phenotypic plasticity in cancer cells including their entrance into stem-cell states. Much is still to be learned about the regulation of EMTs through epigenetic mechanisms in cancer cells and the contributions that EMT programs make to normal tissue homeostasis.
Utility functions for Debreu's ‘excess demands’

Abstract Given an arbitrary function x: R l→ R l satisfying Walras law and homogeneity, Debreu decomposed x into the sum of l ‘individually rational’ functions x(p)=Σlk=1[uvbar|x]k(p). Here we find explicit utility functions uk, constructed on the basis of a simple geometric intuition, which give rise to Debreu's excess demands [uvbar|x]k(p).
Tau as a probe for new physics

The usage of polarimetry and spin-correlation tests to determine the complete Lorenz structure of the tau lepton`s charged and neutral- current couplings is reviewed. The emphasis is on tests for ``something`` in a (V-A)+ ``something`` structure in J{sup charged} Lepton current, so as to bound the scales {lambda} for ``new physics`` such as arising from tau weak magnetism, weak electricity, and/or second-class currents. Tests for T and for CP violation are discussed.
The Yang-Lee edge singularity on a dynamical planar random surface

Abstract We reconsider a recently solved Ising model on a random planar graph. The Yang-Lee edge singularity, familiar from the ordinary Ising model, is exposed. It is shown to correspond to an exactly solvable critical dimer counting problem on the random surface in the infinite temperature limit. This suggests an interesting interpretation of a recently proposed phenomenological model exhibiting multicritical behavior. The critical exponents are found to be γ = − 1 3 (string susceptibility) and σ = 1 2 (edge singularity). The result is at odds with the Knizhnik-Polyakov-Zamolodchikov formula in conjunction with the Yang-Lee edge singularity's central charge C = − 22 5 . Possible explanations are discussed. The result σ = 1 2 coincides with the corresponding exponent of the ordinary three-dimensional spherical model, as does the set of exponents of the random Ising critical point found previously.
Lorentz and CPT violation in the Standard-Model Extension

Lorentz and CPT invariance are among the symmetries that can be investigated with ultrahigh precision in subatomic physics. Being spacetime symmetries, Lorentz and CPT invariance can be violated by minuscule amounts in many theoretical approaches to underlying physics that involve novel spacetime concepts, such as quantized versions of gravity. Regardless of the underlying mechanism, the low-energy effects of such violations are expected to be governed by effective field theory. This talk provides a survey of this idea and includes an overview of experimental efforts in the field.
Does Performing Other Audit Tasks Affect Going-Concern Judgments?

This study examines whether personally performing other audit tasks can bias supervising seniors' going‐concern judgments. During an audit, the senior performs some audit tasks him/herself and delegates other tasks to staff members. When personally performing an audit task, the senior would focus on the evidence related to that task. We predict that such evidence will have greater influence on the senior's subsequent going‐concern judgment. The results of our experiment are consistent with our predictions. When provided with an identical set of information, seniors who performed another audit task for which the underlying facts of the case reflected positively (negatively) on the company's viability, subsequently made going‐concern judgments that were relatively more positive (negative). Our results also demonstrate that the well‐documented tendency of auditors to attend more to negative information does not always dominate auditors' information processing. Subjects who performed the task for which the un...
Efficacy and Safety of Incretin-Based Therapies in Patients with Type 2 Diabetes Mellitus

This article aims to provide an overview of efficacy and safety data on glucagon-like peptide-1 (GLP-1) receptor agonists and dipeptidyl peptidase-4 (DPP-4) inhibitors in the treatment of type 2 diabetes mellitus. Our goal is to differentiate the clinical profiles of GLP-1 receptor agonists and DPP-4 inhibitors, as well as the individual agents within each class. Additionally, we examine the utility of GLP-1 receptor agonists and DPP-4 inhibitors as these agents may be applied at different stages of type 2 diabetes therapy and discuss recently published clinical findings and their implications for treatment.
Vibration-test force limits derived from frequency-shift method

An improved vibration testing technique has been recently developed and applied to eliminate overtesting caused by the infinite mechanical impedance of the shaker in conventional vibration tests. With the new technique, the acceleration input is notched at the resonance frequencies of the test item in order to limit the shaker force to that predicted for flight. Since few flight vibratory force data are available, the force limits must be calculated from measurements or analyses of the flight mounting structure and test-item mechanical impedances. An improved method of calculating these force limits is derived from evaluating the test-item apparent mass at the coupledsystem resonance frequencies. Application of the method to a simple and to a complex coupled oscillator system yields nondimensional results which may be used to calculate limits for future force-limited vibration tests. For example, using the simple system results with Q = 50 and equal impedances of the flight mounting structure and test item, the input acceleration amplitude will be notched by a factor of 31.25 relative to a conventional test.
Binocular function in pseudophakic children.

Purpose The author reports the results of visual and binocular tests performed on patients who had primary insertion of intraocular lenses following the removal of cataracts in their childhood. Methods Monocular and binocular tests were performed on 21 patients using the same equipment for sensory testing for binocularity on all patients before the history was abstracted from the clinical records. These patients were selected from a consecutive series and observed for a minimum of 5 years by their surgeons. Results The mean age at surgery performed on the first eye was 6.3 years. The mean age at the date of the author's examination was 16.5 years and the mean length of follow-up was 10.3 years. All but 2 patients had motor alignment within 8 prism diopters of orthotropia at near. Fusion and some stereopsis was found in 15 patients, but only 4 of these demonstrated fine (60 seconds of arc or better) stereoacuity. Patients with fine versus gross stereoacuity were compared and found to be similar in type of cataract, age at first surgery, interval between surgeries, length of follow-up, and refraction, but different in the quality of best-corrected visual acuity. Conclusion Although satisfactory motor alignment, fusion, and some stereopsis is present in the majority of patients, fine stereoacuity is uncommon in pseudophakic children.
Investigation of mode interaction in optical microresonators for kerr frequency comb generation

Mode interaction in silicon nitride micro-resonators is investigated. We provide clear experimental evidence of mode interaction between two families of transverse modes and demonstrate a link between such interactions and initiation of comb generation in resonators with normal dispersion.
Electronic absorption spectra of cis-M(CO)2(α-diimine)2 complexes (M = Mo or W; α-diimine = 2,2′-bipyridine or 1,10-phenanthroline)

Abstract Syntheses, infrared spectra, and electronic absorption spectra of cis -M(CO) 2 (α-diimine) 2 (M = Mo, W; α-diimine = 2,2′-bipyridine, 1,10-phenanthroline) complexes are reported. Infrared spectra indicate carbonyl stretching frequencies in the 1700–1800 cm −1 region, consistent with strong M(dπ) → (π*)CO back-bonding in these dicarbonyl complexes. Electronic absorption spectra illustrate several intense M(dπ) → (π*)α-diimine transitions throughout the visible region. A comparison of the solvent effects on the absorption spectra of the cis -M(CO) 2 (α-diimine) 2 species is made with the well known M(CO) 4 (α-diimine) complexes.
Adaptive Vibration Isolation for Flexible Structures

Vibration isolation control for flexible structures restricts the response resulting from external disturbances to areas not requiring high precision positioning and/or pointing. This paper introduces adaptive feedback isolation controllers, based on Lyapunov theory, that regulate and allow tracking of the undisturbed (controlled) coordinates in a flexible structure. Under assumptions of inertially decoupled controlled and uncontrolled coordinates, symmetric and positive definite mass matrix for the controlled subsystem, asymptotically stable eigenvalues for the uncontrolled subsystem, and bounded disturbances, an adaptive regulator asymptotically drives the controlled coordinates to zero. Under similar assumptions, an adaptive tracking algorithm drives the controlled coordinates to desired time trajectories. Experimental results on a three mass system compare the response of the adaptive isolation controllers with standard PID control. The adaptive regulator provides faster transient decay than PID control using the same control effort. The adaptive tracking controller has the same tracking error as PID using 30 percent less control effort.
Peritoneal washing cytology is unnecessary in gynecologic surgery for benign diseases.

BACKGROUND The presence of tumor cells in peritoneal washing cytology specimens taken during surgery affects the staging of many gynecologic malignancies. Peritoneal washings are often collected routinely, even in cases of presumed benign disease. This study was designed to address whether evaluation of these specimens is justified. METHODS We reviewed diagnostic reports from all peritoneal washings and the corresponding surgical pathology specimens from patients undergoing gynecologic surgery during a 1-year period in one institution and a 20-month period in the other. Cases were divided into benign and malignant categories based on the surgical pathology diagnosis. RESULTS Three hundred forty-six patients had peritoneal washings collected during the study period. The proportion of cases with malignancy was 30% in one institution and 49% in the other. Of these, 119 had an endometrial or ovarian malignancy, including 16 ovarian tumors of low malignant potential. Malignant cells were detected in 19 cases. In 10 of these 19, grossly apparent peritoneal tumor implants were present at the time of surgery. The remaining 227 were found to have benign disease, and the peritoneal washing cytology diagnosis was negative in all cases. Potential savings of $13,000 to $17,000 based on current insurance reimbursement could have been realized for these 227 patients without compromising patient care. CONCLUSIONS These data suggest that peritoneal washing cytology specimens collected at the time of gynecologic surgery for presumed benign disease can be held and processed later if an unsuspected malignancy is discovered. This practice can result in cost savings without compromising patient care. Cancer (Cancer Cytopathol) 1999;87:259–62. © 1999 American Cancer Society.
Polar domains on globular macromolecules: Shape-persistent, amphiphilic tridendrons

Abstract A series of asymmetric phenylacetylene tridendrons is prepared by coupling polar monodendrons having t -butyl esters on their periphery with a non-polar monodendron having t -butyl groups on its periphery. Subsequent conversion of the t -butyl esters to carboxylic acids by thermolysis gives amphiphilic dendrimers having polar domains of various size. The characterization and solution phase behavior of these structures is discussed.
(+)-Gibberellin C: hydrogen-bonding pattern of the monohydrate of a non-racemic pentacyclic diterpenoid.

In the monohydrate of the title compound, (+)-2β,4aα-di­hydroxy-1,7-di­methyl-8-oxo-4bβ,7α-gibbane-1α,10β-di­carb­ox­yl­ic acid-1,4a-lactone, C19H24O6·H2O, intermolecular hydrogen bonding progresses helically along b from carboxyl to ketone [O⋯O = 2.694 (5) A]. The carboxyl and lactone carbonyl groups in translationally related mol­ecules within a helix both accept hydrogen bonds from the same water of hydration. The oxy­gen of this water in turn accepts a hydrogen bond from the hydroxyl group of a third screw-related mol­ecule in an adjacent counterdirectionally oriented helix, yielding a complex three-dimensional hydrogen-bonding array. Intermolecular O⋯H—C close contacts were found to the carboxyl and lactone carbonyls, the hydroxyl, and the water.
Statistical Effects of Doppler Beaming and Malmquist Bias on Flux-limited Samples of Compact Radio Sources

We examine the effects of Doppler beaming on flux-limited samples of compact radio sources representative of relativistic jets found in active galactic nuclei (AGNs). We expand upon past studies by incorporating a luminosity function and redshift distribution for the parent population and by allowing the unbeamed synchrotron luminosity L of a relativistic jet to be related to its bulk Lorentz factor (Γ). These enhancements allow us to compare observable parameters other than simply apparent velocity with the data. The predictions of L-Γ-independent (LGI) models are compared to those of a L-Γ-dependent (LGD) scenario in which the Lorentz factor and luminosity are related by the form L Γξ. This is accomplished using Monte Carlo simulations, where we compare the predicted flux density, redshift, monochromatic emitted luminosity, and apparent velocity distributions of flux-limited samples to the Caltech-Jodrell Bank sample of bright, flat-spectrum, radio core-dominated AGNs (CJ-F). The LGI model predictions are consistent with the CJ-F data if we adopt parent Lorentz factor distributions of the form N(Γ) Γa, where -1.5 a -1.75, or, alternatively N(Γ) (Γ - 1)a, where -0.5 a -1. These models reproduce, via selection effects, a deficit of sources having both low apparent velocity (βapp) and high monochromatic emitted luminosity (P) seen in the CJ-F sample, as reported by Vermeulen in 1995. We examine two possible cases for the LGD scenario, the first of which employs a positive correlation between unbeamed synchrotron luminosity and Lorentz factor (the LGC model), and the second of which employs an anticorrelation (the LGA model). The LGA models do not predict enough low-P sources to be consistent with the CJ-F data and do not reproduce the P versus βapp envelope. The predictions of the best-fit LGC model, on the other hand, are very similar to our best-fit LGI models and provide as good fits to the CJ-F data, with the important exception that very few high-viewing angle sources are predicted. This in conflict with the large fraction (11%) of radio galaxies present in the CJ-F sample, whose jet axes are predicted by the unified AGN model to be at angles greater than ~45° to the line of sight. At present, the observational data on the CJ-F sample are otherwise insufficient to distinguish between the LGI and LGC models. Our simulations indicate, however, that the LGC models predict a larger number of high (δ > 20) Doppler factor sources in flux-limited samples. Furthermore, the predicted median variability timescale of the high (βapp > 10 h-1) objects is only ~20 times faster than the low βapp < 2.5 h-1 objects in the LGC models, whereas the LGI models predict a ratio of ~200. We find that all of our models predict a very large parent population for the CJ-F sample: on the order of 107-107.7 objects are required to produce 293 objects with flux densities greater than 350 mJy for the LGC and LGI models, respectively. This translates into parent population space densities on the order of (1.3-5.9) × 10-5 Mpc-3 for H0 = 65 km s-1 Mpc-1 and q0 = 0.
Mass motions associated with solar flares

Mass motions are a principal means by which components of solar flares can be distinguished. Typical patterns of mass motions in Ha are described for chromospheric flare ribbons, remote chromospheric flare patches, flare loops, flaring arches, surges, erupting filaments and some expanding coronal features. Interrelationships between these phenomena are discussed and illustrations of each are presented.
Quantitative imaging and diffraction of zeolites using a slow-scan CCD camera

Abstract We demonstrate ways in which structural information on zeolites can be obtained from high-resolution images and electron diffraction patterns. We employ a commercial slow-scan CCD camera to record the data and demonstrate the advantage of on-line data processing and analysis. Quantitative agreement is obtained between experimental electron diffraction intensities and theoretical calculations. Real-space averaging is a versatile technique which can be employed to reduce the effects of both noise and radiation damage. Under favorable circumstances the weak-phase object approximation can be used to simplify image interpretation and quantification.
Spectroscopic characterization of gapped graphene in the presence of circularly polarized light

We present a description of the energy loss of a charged particle moving parallel to a graphene layer and graphene double layers. Specifically, we compare the stopping power of the plasma oscillations for these two configurations in the absence as well as the presence of circularly polarized light whose frequency and intensity can be varied to yield an energy gap of several hundred meV between the valence and conduction bands. The dressed states of the Dirac electrons by the photons yield collective plasma excitations whose characteristics are qualitatively and quantitatively different from those produced by Dirac fermions in gapless graphene, due in part to the finite effective mass of the dressed electrons. For example, the range of wave numbers for undamped self-sustaining plasmons is increased as the gap is increased, thereby increasing the stopping power of graphene for some range of charged particle velocity when graphene is radiated by circularly polarized light.
New Transition‐Metal‐Dependent DNAzymes as Efficient Endonucleases and as Selective Metal Biosensors

Like proteins and RNA molecules, many DNA molecules have now been shown to catalyze a variety of reactions and are thus called DNAzymes. With limited building blocks, DNAzymes need to recruit other cofactors in order to match other enzymes in terms of reaction diversity and catalytic efficiency. Several unique properties make transition-metal ions an ideal choice of cofactor for DNAzymes. Indeed, new DNAzymes that bind transition-metal ions with high affinity and selectivity have been obtained through the use of a powerful combinatorial biology tool called in vitro selection. This accomplishment now makes it possible to obtain different classes of metallo-DNAzymes in the laboratory within a short period of time. It also offers a rare opportunity to compare and contrast structural and functional properties of metal-binding sites in proteins and in DNAzymes. The resulting transition-metal-dependent DNAzymes have displayed high activity toward cleavage of DNA and RNA and thus hold promise for their biochemical and pharmaceutical applications. Finally, the use of DNAzymes as a new class of highly sensitive and selective biosensors for metal ions has been demonstrated recently.
The solvent-free and catalyst-free conversion of an aziridine to an oxazolidinone using only carbon dioxide

It has been found for the first time at room temperature that the reaction of an unactivated 2-alkyl or 2-aryl aziridine with carbon dioxide to generate the corresponding oxazolidinone does not need any form of catalysis or solvent to proceed in high yield, especially when using high speed ball milling.
Soft gamma-ray bursts from accreting compact objects

THE recent report that Vela satellites have detected 16 soft γ-ray bursts1 has generated great interest in the possible sources of such bursts2,3. Here we consider the possibility that the γ-ray bursts may originate from fleeting episodes of accretion onto compact galactic objects. We first describe the characteristics of the observations which make this general class of models an attractive one and then discuss a particular example which appears promising, namely the triggering of bursts by solar-type flares in a binary companion.
BERNINAMYCINS B, C, AND D, MINOR METABOLITES FROM Streptomyces bernensis

Berninamycins B, C, and D were isolated from fermentation of Streptomyces bernensis and their structures were studied with 13C NMR and FAB mass spectrometry. Berninamycin B has a valine unit in its cyclic peptide loop instead of the beta-hydroxyvaline unit found in berninamycin A. Berninamycin D has two fewer dehydroalanine units attached to the carboxyl carbon of the pyridine ring. Based on FAB-MS results, berninamycin C is postulated to have only one dehydroalanine unit attached to the carboxyl carbon of pyridine. The biogenesis of berninamycins B, C, and D is discussed.
Utilization of glycosyltransferases to change oligosaccharide structures

Carbohydrates on cell surfaces are important biomolecules in various biological recognition processes. Elucidation of the biological roles of complex oligosaccharides necessitates an efficient methodology to synthesize these compounds and their analogs. Enzymatic synthesis renders itself to be useful in the construction of an oligosaccharide structure owing to its mild reaction condition, high regio- and stereoselectivity. This review article focuses on the recent progress in oligosaccharide syntheses catalyzed by glycosyltransferases, namely sialyltransferase, galactosyltransferase, fucosyltransferase, and N-acetylglucosaminyltransferase. A survey of the latest patent and literature related to this field is also included.
Simulation Techniques for the Test and Evaluation of Real-Time Computer Programs

The use of high-speed, general-purpose digital computers to control and coordinate the elements of real-time physical systems (e.g., air traffic control), poses several challenging problems in the area of system test and evaluation. As in more conventional computer applications, adequate emphasis must be given to a thorough program checkout; real-time programs, however, must also be tested and evaluated in a proper environment to ensure the adequacy and compatibility of program and system design. In a computer-controlled air traffic system, for example, comprehensive tests would be required to evaluate safety and adequacy of performance prior to full operational use. Techniques for evaluating mechanical and electronic equipment are well known, and the importance of proper test equipment is established. Program and system evaluation can be accomplished by similar techniques if facilities are provided to simulate the action of the external system by generating synthetic, but realistic, computer inputs, and monitor and analyze system outputs.