cssi/SciSciGPT-SciSciNet huggingface dataset:
A theory for turbulent curved wall jets

An attempt is made to formulate the simplest possible model for the flow of a wall jet emanating from a two dimensional source into quiescent surroundings in the presence of a wall of arbitrary shape. The method used self similar profiles for the mean velocity together with a simple eddy viscosity model. The streamwise and radial momentum equations are integrated across the wall jet flow to give an expression for the momentum balance including the effect of the pressure gradient induced by the rate of change of surface curvature. The streamwise momentum equation is also evaluated at the point of maximum velocity to provide a second equation and thereby permit a solution for the two unknown quantities, the jet half width and the maximum velocity. This approach provides approximate closed form solutions for the flow of the wall jet over surfaces of various shapes, and in particular permits a direct comparison with the available experimental results for plane, cylindrical or logarithmic spiral surfaces.
Inequalities for Composite Functions on a Lattice

Inequalities are identified for subadditive (superadditive) functions of supermodular (submodular) functions. A simple adaptation yields inequalities for submultiplicative (supermultiplicative) compositions of log-supermodular (log-submodular) functions. Inequalities are also developed when the order of composition is reversed.
Understanding complexity in the structure of rainfall

This paper aims at understanding the structure of high resolution storm rainfall rates. Scale invariance property has been observed from the distribution function. Departures from simple scaling (i.e., multiscaling) have been noted, suggesting a cascade phenomenon. Close agreement of theoretical and estimated singularity spectra indicates the plausibility of modeling rainfall process by random cascades. Connections between multiscaling and the singularity spectrum have been identified.
Toric ideals of homogeneous phylogenetic models

We consider the model of phylogenetic trees in which every node of the tree is an observed, binary random variable and the transition probabilities are given by the same matrix on each edge of the tree. The ideal of invariants of this model is a toric ideal in C[p;i1;…i;n;]. We are able to compute the Gobner basis and minimal generating set for this ideal for trees with up to 11 nodes. These are the first non-trivial Grobner bases calculations in 211 = 2048 indeterminates. We conjecture that there is a quadratic Grobner basis for binary trees, but that generators of degree n are required for some trees with n nodes. The polytopes associated with these toric ideals display interesting finiteness properties. We describe the polytope for an infinite family of binary trees and conjecture (based on extensive computations) that there is a universal bound on the number of vertices of the polytope of a binary tree.
Continued fraction proofs of m -versions of some identities of Rogers–Ramanujan–Slater type

We derive two general transformations for certain basic hypergeometric series from the recurrence formulae for the partial numerators and denominators of two q-continued fractions previously investigated by the authors.
The Preparation and Evaluation of Electron Poor Benzylidene Fischer Carbene Complexes: Studies Toward the Total Synthesis of (+)-Olivin

Abstract The continued exploration into the fate of the benzannulation reaction is put forth using the electronic nature of substituents on the aryl ring of benzylidene Fischer carbene complexes as a handle to predict, using σ - para values as a guide, the outcome of the reaction based on the accepted mechanism. The design of this work focuses on evaluation of the synthetic utility of the benzannulation reaction and the means by which this reaction may be improved to be a better synthetic tool in the preparation of complex natural products as this is illustrated in our ongoing total synthesis of (+)-olivin which uses the benzannulation reaction as the key convergent synthetic step. To accomplish these tasks, the preparation of several electron poor benzylidene Fischer carbene complexes was carried out and their reaction with simple alkyne substrates studied. While much is known about the preparation of electron rich benzylidene Fischer carbene complexes, little is known about the preparation of their electron poor counterparts. Thus efforts toward developing useful preparative methods of these elusive targets has also been studied. While the use of both carbon and oxygen based aryl substituents has been explored, to date the preparation of benzylidene carbene complexes containing oxygen based aryl substituents has been exploited to a greater degree since these systems carry more immediate synthetic importance. This is so because the skeletal core of many of the natural products that have been targeted with the benzannulation reaction including (+)-olivin contain a highly oxygenated polycyclic aromatic core. The enhancement in efficiency of the benzannulation reaction using this synthetic methodology is demonstrated by the successful completion of the convergent synthetic step in the total synthesis of (+)-olivin.
IGT/COMFET Latching Characteristics and Application to Brushless DC Motor Drive

Various factors affecting the device latching current level were investigated. Results of applying the devices for driving a 340 V, 10 A brushless dc motor are presented. Recommendations to the device manufacturers, from the user's point of view, are summarized.
Ultrasound attenuation in gap-anisotropic systems.

Transverse ultrasound attenuation provides a weakly coupled probe of momentum current correlations in electronic systems. We develop a simple theory for the interpretation of transverse ultrasound attenuation coefficients in systems with nodal gap anisotropy. Applying this theory we show how ultrasound can delineate between extended-$s$ and $d$-wave scenarios for the cuprate superconductors.
The economics of exhaustible resources

Contemplation of the world’s disappearing supplies of minerals, forests, and other exhaustible assets has led to demands for regulation of their exploitation. The feeling that these products are now too cheap for the good of future generations, that they are being selfishly exploited at too rapid a rate, and that in consequence of their excessive cheapness they are being produced and consumed wastefully has given rise to the conservation movement. The method ordinarily proposed to stop the wholesale devastation of irreplaceable natural resources, or of natural resources replaceable only with difficulty and long delay, is to forbid production at certain times and in certain regions or to hamper production by insisting that obsolete and inefficient methods be continued. The prohibitions against oil and mineral development and cutting timber on certain government lands have this justification, as have also closed seasons for fish and game and statutes forbidding certain highly efficient means of catching fish. Taxation would be a more economic method than publicly ordained inefficiency in the case of purely commercial activities such as mining and fishing for profit, if not also for sport fishing. However, the opposition of those who are making the profits, with the apathy of everyone else, is usually sufficient to prevent the diversion into the public treasury of any considerable part of the proceeds of the exploitation of natural resources.
On the use of registers in achieving wait-free consensus

The computational power of concurrent data types has been the focus of much recent research. Herlihy showed that such power may be measured by the type's ability to implement wait-free consensus. Jayanti argued that this ability could be measured in different ways, depending, for example, on whether or not read/write registers could be used in an implementation. He demonstrated the significance of this distinction by exhibiting a nondeterministic type whose ability to implement consensus was increased with the availability of registers. We show that registers cannot increase the ability to implement wait-free consensus of any deterministic type or of any type that can, without them, implement consensus for at least two processes. These results significantly impact the study of the wait-free hierarchies of concurrent data types. In particular, the combination of these results with other recent work suggests that Jayanti's h m hierarchy is robust for certain classes of deterministic types.
Analyses of Cardinal Auctions

We study cardinal auctions for selling multiple copies of a good, in which bidders specify not only their bid or how much they are ready to pay for the good, but also a cardinality constraint on the number of copies that will be sold via the auction. We perform first known Price of Anarchy type analyses with detailed comparison of the classical Vickrey-Clarke-Groves (VCG) auction and one based on minimum pay property (MPP) which is similar to Generalized Second Price auction commonly used in sponsored search. Without cardinality constraints, MPP has the same efficiency (total value to bidders) and at least as much revenue (total income to the auctioneer) as VCG; this also holds for certain other generalizations of MPP (e.g., prefix constrained auctions, as we show here). In contrast, our main results are that, with cardinality constraints,
Efficient parallel algorithms for computing all pair shortest paths in directed graphs

We present parallel algorithms for computing all pair shortest paths in directed graphs. Our algorithm has time complexityO(f(n)/p+I(n)logn) on the PRAM usingp processors, whereI(n) is logn on the EREW PRAM, log logn on the CCRW PRAM,f(n) iso(n 3). On the randomized CRCW PRAM we are able to achieve time complexityO(n 3/p+logn) usingp processors.
Controller design in the physical domain

Abstract “Design in the Physical Domain” is proposed as a means of integrating control systems design with mechanical systems design. This approach facilitates separation of design issues from implementation issues through high-level abstraction, and provides guidance in selecting the proper physical architecture for a given control task. As an example it is shown how this philosophy may lead to alternative robot architectures that are inherently stable and well-suited for high performance end-point control.
Skew Derivations and Deformations of a Family of Group Crossed Products

We obtain deformations of a crossed product of a polynomial algebra with a group, under some conditions, from universal deformation formulas. We show that the resulting deformations are nontrivial by a comparison with Hochschild cohomology. The universal deformation formulas arise from actions of Hopf algebras generated by automorphisms and skew derivations, and are universal in the sense that they apply to deform all algebras with such Hopf algebra actions.
Spatial and supply/demand agglomeration economies: State- and industry-linkages in the U.S. food system

Cost-impacts of spatial and industrial spillovers on economic performance are evaluated by incorporating activity level measures for nearby states and related industries into a cost function model. We focus on localization and urbanization economies for state level food processing industries, from activity levels of similar industries in neighboring states, agricultural input suppliers, and final product demand. We find significant cost-savings from proximity to other food manufacturing centers, and areas with high purchasing power. Cost savings from locating near an agricultural area are also evident, although it seems costly to be located within a rural agricultural state, implying thin market diseconomies. Marginal production costs instead appear higher in more urban, and lower in more rural, areas. These spillover patterns also have input composition implications; materials demand responses are the most closely tracked by the agglomeration cost effects, and capital and labor impacts vary.
Rearrangements of cyclopropenes into five-membered aromatic heterocycles: mechanistic aspect

This review covers rearrangements of cyclopropenes into aromatic five-membered heterocyclic compounds, namely furans and pyrroles; accompanied by small ring cleavage proceeding in the presence of catalytic amounts of transition metals, Lewis acids, or under UV irradiation.
Ultrafine spinel powders by flame spray pyrolysis of a magnesium aluminum double alkoxide

Ultrafine crystalline spinel powder has been prepared using flame spray pyrolysis of alcoholic solutions of a novel double alkoxide precursor. The particles produced are spherical, dense, single crystals with diameters of 10--100 nm and specific surface areas ranging from 40 to 60 m{sup 2}/g. Powder production rates of 50--100 g/h are achieved using a bench-top apparatus. Particle formation appears to occur by rapid oxidation of the organic ligands followed by nucleation and growth from oxide species.
Role of the densest lattice planes in the stability of crystalline interfaces: A computer simulation study☆

Abstract The zero-temperature energies and equilibrium volume expansions of point-defect-free grain boundaries (GBs) on the two densest planes of f.c.c. copper, b.c.c. molybdenum and cubic diamond silicon have been determined, using an Embedded-Atom-Method potential for copper, a Finnis-Sinclair potential for molybdenum, and the Stillinger-Weber potential for silicon. It is found that in all three structures the energies of the GBs on the second-densest planes are about two to three times higher than of those on the densest planes. For the metals a strong correlation between GB energy and volume expansion at the GB is observed. Owing to its covalent nature of bonding such a correlation is not found for silicon. It is illustrated that atoms in very close contact (up to about 10% closer than the perfect-crystal nearest-neighbor distance) are mainly responsible for the very large anisotropy in the GB energy. Since the strong repulsive forces between such atoms should be active even in complex interface systems (such as metal-ceramic interfaces or strained-layer superlattices), we suggest that the energetics of even more general interfaces is strongly influenced by the Pauli principle.
Instability of compressible boundary layers along curved walls with suction or cooling

This paper investigates the effect of suction of the boundary layer and wall cooling on the growth and development of three-dimensional longitudinal vortices over concave walls. The study is carried out for compressible flows for a range of Mach numbers from 0 to 5. Despite indications that small suction or small cooling rates locally reduce the critical Goertler number (destabilize the boundary layer), the overall effect of suction or cooling is to stabilize the boundary layer by reducing the amplitude ratio of the vortices. In case of suction, this becomes more difficult with increasing Mach number unless high suction rates are used. On the other hand, stabilizing the boundary layer with respect to Goertler vortices can hardly be achieved by cooling even when high cooling rates are used.
Hyperbolicity of the invariant sets for the real polynomial maps

Abstract In this paper, the conditions under which there exits a uniformly hyperbolic invariant set for the map f a ( x ) = ag ( x ) are studied, where a is a real parameter, and g ( x ) is a monic real-coefficient polynomial. It is shown that for certain parameter regions, the map has a uniformly hyperbolic invariant set on which it is topologically conjugate to the one-sided subshift of finite type for A , where ∣ a ∣ is sufficiently large, A is an eventually positive transition matrix, and g has at least two different real zeros or only one real zero. Further, it is proved that there exists an invariant set on which the map is topologically semiconjugate to the one-sided subshift of finite type for a particular irreducible transition matrix under certain conditions, and one type of these maps is not hyperbolic on the invariant set.
Grote Reber (1911–2002)

A forceful personality and self-confidence led Grote Reber to a series of remarkable discoveries in radio astronomy, and later to a wide variety of research in many other fields of science and technology. Although he worked primarily as an amateur, independently of the scientific establishment, Reber was ultimately recognized with many of the major prizes in astronomy.
Study of Prediagnostic Selenium Level in Toenails and the Risk of Advanced Prostate Cancer

Background In a recent randomized intervention trial, the risk of prostate cancer for men receiving a daily supplement of 200 microg selenium was one third of that for men receiving placebo. By use of a nested case-control design within a prospective study, i.e., the Health Professionals Follow-Up Study, we investigated the association between risk of prostate cancer and prediagnostic level of selenium in toenails, a measure of long-term selenium intake. Methods In 1986, 51,529 male health professionals aged 40-75 years responded to a mailed questionnaire to form the prospective study. In 1987, 33,737 cohort members provided toenail clippings. In 1988, 1990, 1992, and 1994, follow-up questionnaires were mailed. From 1989 through 1994, 181 new cases of advanced prostate cancer were reported. Case and control subjects were matched by age, smoking status, and month of toenail return. Selenium levels were determined by neutron activation. All P values are two-sided. Results The selenium level in toenails varied substantially among men, with quintile medians ranging from 0.66 to 1.14 microg/g for control subjects. When matched case-control data were analyzed, higher selenium levels were associated with a reduced risk of advanced prostate cancer (odds ratio [OR] for comparison of highest to lowest quintile = 0.49; 95% confidence interval [CI] = 0.25-0.96; P for trend = .11). After additionally controlling for family history of prostate cancer, body mass index, calcium intake, lycopene intake, saturated fat intake, vasectomy, and geographical region, the OR was 0.35 (95% CI = 0.16-0.78; P for trend = .03). Conclusions Our results support earlier findings that higher selenium intakes may reduce the risk of prostate cancer. Further prospective studies and randomized trials of this relationship should be conducted.
A self-consistent study of triaxial black-hole nuclei

We construct models of triaxial galactic nuclei containing central black holes using the method of orbital superposition and then verify their stability by advancing N-body realizations of the models forward in time. We assume a power-law form for the stellar density, ρ ∝ r-γ, with γ = 1 and 2; these values correspond approximately to the nuclear density profiles of bright and faint galaxies, respectively. Equidensity surfaces are ellipsoids with fixed axis ratios. The central black hole is represented by a Newtonian point mass. We consider three triaxial shapes for each value of γ: almost prolate, almost oblate, and maximally triaxial. Two kinds of orbital solution are attempted for each mass model: the first including only regular orbits, the second including chaotic orbits as well. We find that stable configurations exist, for both values of γ, in the maximally triaxial and nearly oblate cases; however, steady state solutions in the nearly prolate geometry could not be found. A large fraction of the mass, of order 50% or more, could be assigned to the chaotic orbits without inducing evolution. Our results demonstrate that triaxiality may persist even within the sphere of influence of the central black hole and that chaotic orbits may constitute an important building block of galactic nuclei.
A note on non-parametric and semi-parametric modeling of wildfire hazard in Los Angeles County, California

This paper explores the use of, and problems that arise in, kernel smoothing and parametric estimation of the relationships between wildfire incidence and various meteorological variables. Such relationships may be treated as components in separable point process models for wildfire activity. The resulting models can be used for comparative purposes in order to assess the predictive performance of the Burning Index.
DIRECT DETECTIONS OF YOUNG STARS IN NEARBY ELLIPTICAL GALAXIES

Small amounts of star formation in elliptical galaxies are suggested by several results: surprisingly young ages from optical line indices, cooling X-ray gas, and mid-infrared dust emission. Such star formation has previously been difficult to directly detect, but using ultraviolet Hubble Space Telescope Wide Field Camera 3 imaging, we have identified individual young stars and star clusters in four nearby ellipticals. Ongoing star formation is detected in all galaxies, including three ellipticals that have previously exhibited potential signposts of star-forming conditions (NGC 4636, NGC 4697, and NGC 4374), as well as the typical "red and dead" NGC 3379. The current star formation in our closest targets, where we are most complete, is between 2.0 and 9.8 × 10–5 M ☉ yr–1. The star formation history was roughly constant from 0.5 to 1.5 Gyr (at (3-5) × 10–4 M ☉ yr–1), but decreased by a factor of several in the past 0.3 Gyr. Most star clusters have a mass between 102 and 104 M ☉. The specific star formation rates of ~10–16 yr–1 (at the present day) or ~10–14 yr–1 (when averaging over the past Gyr) imply that a fraction 10–8 of the stellar mass is younger than 100 Myr and 10–5 is younger than 1 Gyr, quantifying the level of frosting of recent star formation over the otherwise passive stellar population. There is no obvious correlation between either the presence or spatial distribution of postulated star formation indicators and the star formation we detect.
Threshold dynamics in soil carbon storage for bioenergy crops.

Because of increasing demands for bioenergy, a considerable amount of land in the midwestern United States could be devoted to the cultivation of second-generation bioenergy crops, such as switchgrass and miscanthus. The foliar carbon/nitrogen ratio (C/N) in these bioenergy crops at harvest is significantly higher than the ratios in replaced crops, such as corn or soybean. We show that there is a critical soil organic matter C/N ratio, where microbial biomass can be impaired as microorganisms become dependent upon net immobilization. The simulation results show that there is a threshold effect in the amount of aboveground litter input in the soil after harvest that will reach a critical organic matter C/N ratio in the soil, triggering a reduction of the soil microbial population, with significant consequences in other microbe-related processes, such as decomposition and mineralization. These thresholds are approximately 25 and 15% of aboveground biomass for switchgrass and miscanthus, respectively. These ...
Cerebral Hemodynamic Changes Induced by Simulated Tracheal Intubation: A Possible Role in Perioperative Stroke? Magnetic Resonance Angiography and Flow Analysis in 160 Cases

Background and Purpose—Perioperative stroke is a rare complication of generalized surgery (1% to 6%). Unexpected difficulties with tracheal intubation (TI), as well as the hyperextended position, may predispose a patient to or play a role in stroke. We sought to identify blood flow changes in carotid and vertebral arterial circulation during simulated TI and develop profile models for stroke risk before possible generalized surgery. Methods—One hundred sixty consecutive patients with suspected cerebral vascular disease or pending surgery underwent MR angiography with flow analysis. Simulated TI position was maintained for 3 to 4 minutes per acquisition. Results—The cohort consisted of 89 females (56%) and 71 males (44%) with a mean age of 66 years (range, 17 to 89 years). Hypoplastic vertebral arteries with flow less than 50 mL/s were present in 40 patients (25%). Profound alteration in basilar artery flow was noted in this group with increased frequency of microinfarctions on MRI (77% versus 38%). Unsusp...
Singular vectors in logarithmic conformal field theories

Abstract Null vectors are generalized to the case of indecomposable representations which are one of the main features of logarithmic conformal field theories. This is done by developing a compact formalism with the particular advantage that the stress energy tensor acting on Jordan cells of primary fields and their logarithmic partners can still be represented in form of linear differential operators. Since the existence of singular vectors is subject to much stronger constraints than in regular conformal field theory, they also provide a powerful tool for the classification of logarithmic conformal field theories.
The stereochemistry of carbonyl oxides from ozonolysis of vinyl ethers

Abstract The geometries of the carbonyl oxides produced during ozonolysis of E- and Z-vinyl ethers have been assigned using the intramolecular trapping method. The alkoxy substituent exerts an anti-directive effect on formation of the carbonyl oxide; that is, the carbonyl oxide has a geometry opposite to that of the precursor vinyl ether.
The radial variation of corotating energetic particle streams in the inner and outer solar system

The radial gradient of long-lived, corotating energetic particle streams was measured using observations of .9-2.2 MeV protons from Helios 1 and 2, IMP 7, Pioneer 10 and Pioneer 11. A positive gradient of approximately 350% per AU is found between .3 AU and 1 AU. Between 1 AU and some 3-5 AU, the gradient is variable with an average value of 100% per AU which is consistent with earlier statistical results. A comparison between measurements at 9 AU and approximately 4 AU shows a negative gradient which is variable from -40 to -100% per AU. Possible solar latitudinal effects on these gradient studies are also discussed. Using solar wind and magnetic field data from Helios 1 between 1 AU and .3 AU, the relation between corotating energetic particle events in the inner solar system and the interplanetary medium is examined. It is found that the energetic particles are contained inside the high speed solar wind stream in a region adjacent to the interaction region between low speed and high speed streams.
Weighted-least-squares phase reconstruction from the bispectrum

A new weighted-least-squares algorithm for phase estimation from the bispectrum is presented. The algorithm uses phasors instead of phases to avoid modulo-2π ambiguities present in the bispectrum phases. The performance of this algorithm is compared with the performances of several other previously proposed algorithms from both simulated and field data. It is shown that the new algorithm results in more accurate phase-spectrum estimates than the other approaches.
Chemical ionization of chloromethanes for matrix isolation spectroscopy

Abstract A chemical ionization source from mass spectrometry has been used with CCl 4 , CHCl 3 and CH 2 Cl 2 /argon mixtures for matrix isolation spectroscopy in the IR and visible-near UV regions. The major product absorptions in both regions have been observed and assigned previously. The comparison of positive and negative ion operation is striking for CCl 4 ; the yields of CCl + 3 , CCl + 4 and Cl + 3 are increased and HCl − 2 is not produced in positive ion operation.
Concerted but Noncooperative Activation of Nucleotide and Actuator Domains of the Ca-ATPase Upon Calcium Binding

Calcium-dependent domain movements of the actuator (A) and nucleotide (N) domains of the SERCA2a isoform of the Ca-ATPase were assessed using constructs containing engineered tetracysteine binding motifs, which were expressed in insect High-Five cells and subsequently labeled with the biarsenical fluorophore 4′,5′-bis(1,3,2-dithioarsolan-2-yl)fluorescein (FlAsH-EDT2). Maximum catalytic function is retained in microsomes isolated from High-Five cells and labeled with FlAsH-EDT2. Distance measurements using the nucleotide analog 2′,3′-O-(2,4,6-trinitrophenyl) adenosine 5′-triphosphate (TNP-ATP), which acts as a fluorescence resonance energy transfer (FRET) acceptor from FlAsH, identify a 2.4 A increase in the spatial separation between the N- and A-domains induced by high-affinity calcium binding; this structural change is comparable to that observed in crystal structures. No significant distance changes occur across the N-domain between FlAsH and TNP-ATP, indicating that calcium activation induces rigid bo...
Auctioning to buyers with correlated values

In a laboratory setting, a monopolistic auctioneer sells to buyers as the level and nature of demand changes. I ask whether sellers correctly recognize the role played by correlation among buyers' values. The prices set by subjects closely match the risk-neutral benchmark predictions when demand follows the independent-private-values framework. In contrast, subjects fail to correctly account for correlation among buyers' values once the independence assumption is dropped. I offer two new models of pricing in a correlated-values environment. The model that suggests sellers ignore correlation outperforms both the benchmark and the model that suggests sellers incorrectly account for correlation.
Room-Temperature Synthesis of ZIF-8: The Coexistence of ZnO Nanoneedles

We followed the crystallization-time dependence of zeolitic imidazolate framework, ZIF-8. Interestingly, when zinc carbonate basic was used as the metal source, the coexistance of ZIF-8 and ZnO nanoneedles was observed. Long synthesis times promoted the complete crystallization of ZIF-8. The kinetics of transformation is governed by Avrami’s classic model.
The Dartmouth Stellar Evolution Database

The ever-expanding depth and quality of photometric and spectroscopic observations of stellar populations increase the need for theoretical models in regions of age-composition parameter space that are largely unexplored at present. Stellar evolution models that employ the most advanced physics and cover a wide range of compositions are needed to extract the most information from current observations of both resolved and unresolved stellar populations. The Dartmouth Stellar Evolution Database is a collection of stellar evolution tracks and isochrones that spans a range of [Fe/H] from –2.5 to +0.5, [α/Fe] from –0.2 to +0.8 (for [Fe/H] ≤ 0) or +0.2 (for [Fe/H] > 0), and initial He mass fractions from Y = 0.245 to 0.40. Stellar evolution tracks were computed for masses between 0.1 and 4 M☉, allowing isochrones to be generated for ages as young as 250 Myr. For the range in masses where the core He flash occurs, separate He-burning tracks were computed starting from the zero age horizontal branch. The tracks and isochrones have been transformed to the observational plane in a variety of photometric systems including standard UBV(RI)C, Stromgren uvby, SDSS ugriz, 2MASS JHKs, and HST ACS/WFC and WFPC2. The Dartmouth Stellar Evolution Database is accessible through a Web site at http://stellar.dartmouth.edu/~models/ where all tracks, isochrones, and additional files can be downloaded.
Morse-Bott homology

We give a new proof of the Morse Homology Theorem by constructing a chain complex associated to a Morse-Bott-Smale function that reduces to the Morse-Smale-Witten chain complex when the function is Morse-Smale and to the chain complex of smooth singular N-cube chains when the function is constant. We show that the homology of the chain complex is independent of the Morse-Bott-Smale function by using compactified moduli spaces of time dependent gradient flow lines to prove a Floer-type continuation theorem.
Multilayer mirrors for x rays and the extreme UV

The history, fabrication, and uses of multilayer reflectors for x radiation and far ultraviolet radiation are reviewed. (AIP)
A SHORT PROCEDURE FOR SYNTHESIS OF 4-ETHYNYL-2,2,6,6-TETRAMETHYL-3,4-DEHYDRO-PIPERIDINE-1-OXYL NITROXIDE

The spin-probe labeling technique has been applied to DNA and offers the possibility of studying antisense agents in cells. Simpler syntheses of spin-probes for incorporation into DNA would facilitate this. Here, we describe the synthesis of a new spin probe that requires half the number of steps of related 5 ring nitroxide.
Evolution, psychopathology, and sexual offending: Aping our ancestors

Although sexual offending enjoys an emerging literature, thought and research in this area seem entirely divorced from that on reproduction. Only recently has an evolutionary view been brought to light in this area. Recent literature notes the relative rarity with which people commit crimes against their biological relatives and the differences between males and females in pursuing their romantic and sexual interests. The goal of this theoretical note is to examine how the lens of evolutionary theory can help focus some light on the phenomena of sexual abuse.
First-passage properties of the Erdos Renyi random graph

We study the mean time for a random walk to traverse between two arbitrary sites of the Erdős–Renyi random graph. We develop an effective medium approximation that predicts that the mean first-passage time between pairs of nodes, as well as all moments of this first-passage time, are insensitive to the fraction p of occupied links. This prediction qualitatively agrees with numerical simulations away from the percolation threshold. Near the percolation threshold, the statistically meaningful quantity is the mean transit rate, namely, the inverse of the first-passage time. This rate varies non-monotonically with p near the percolation transition. Much of this behaviour can be understood by simple heuristic arguments.
The expulsion of stellar envelopes in core-collapse supernovae

We examine the relation between presupernova stellar structure and the distribution of ejecta in core-collapse supernovae of Types Ib, Ic, and II, under the approximations of adiabatic, spherically symmetric flow. We develop a simple yet accurate analytical formula for the velocity of the initial forward shock that traverses the stellar envelope. For material that does not later experience a strong reverse shock, the entropy deposited by this forward shock persists into the final, freely expanding state. We demonstrate that the final density distribution can be approximated with simple models for the final pressure distribution, in a way that matches the results of simulations. Our results indicate that the distribution of density and radiation pressure in a star's ejecta depends on whether the outer envelope is radiative or convective, and if convective, on the composition structure of the star. Our models are most accurate for the high-velocity ejecta cast away from the periphery of a star. For stellar structures that limit to a common form in this region, the resulting ejecta limit to a common distribution at high velocities because the blast wave forgets its history as it approaches the stellar surface. We present formulae for the final density distribution of this material as a function of mass, for both radiative and efficiently convective envelopes. These formulae limit to the well-known planar, self-similar solutions for mass shells approaching the stellar surface. However, the assumption of adiabatic flow breaks down for shells of low optical depth, so this planar limit need not be attained. The event of shock emergence, which limits adiabatic flow, also produces a soft X-ray burst of radiation. Formulae are given for the observable properties of this burst and their dependence on the parameters of the explosion. Motivated by the relativistic expansion recently inferred by Kulkarni et al. for the synchrotron shell around SN 1998bw, we estimate the criterion for relativistic mass ejection and the rest mass of relativistic ejecta. We base our models for the entire ejecta distribution on the high-velocity solution, on our shock-velocity formula, and on realistic radiation pressure distributions. We also present simpler, but less flexible, analytical approximations for ejecta distributions. We survey the ejecta of the polytropic hydrogen envelopes of red supergiants. Our models will be useful for studies of the light curves and circumstellar or interstellar interactions of core-collapse supernovae, and of the birth of pulsar nebulae in their ejecta.
OBSERVATIONAL CONSTRAINTS ON RED AND BLUE HELIUM BURNING SEQUENCES

We derive the optical luminosity, colors, and ratios of the blue and red helium burning (HeB) stellar populations from archival Hubble Space Telescope observations of nineteen starburst dwarf galaxies and compare them with theoretical isochrones from Padova stellar evolution models across metallicities from Z = 0.001 to 0.009. We find that the observational data and the theoretical isochrones for both blue and red HeB populations overlap in optical luminosities and colors and the observed and predicted blue to red HeB ratios agree for stars older than 50 Myr over the time bins studied. These findings confirm the usefulness of applying isochrones to interpret observations of HeB populations. However, there are significant differences, especially for the red HeB population. Specifically, we find (1) offsets in color between the observations and theoretical isochrones of order 0.15 mag (0.5 mag) for the blue (red) HeB populations brighter than MV ~ –4 mag, which cannot be solely due to differential extinction; (2) blue HeB stars fainter than MV ~ –3 mag are bluer than predicted; (3) the slope of the red HeB sequence is shallower than predicted by a factor of ~3; and (4) the models overpredict the ratio of the most luminous blue to red HeB stars corresponding to ages 50 Myr. Additionally, we find that for the more metal-rich galaxies in our sample (Z 0.5 Z ☉), the red HeB stars overlap with the red giant branch stars in the color-magnitude diagrams, thus reducing their usefulness as indicators of star formation for ages 100 Myr.
ON ALGEBRAIC STRUCTURES IMPLICIT IN TOPOLOGICAL QUANTUM FIELD THEORIES

We show that any 3D topological quantum field theory satisfying physically reasonable factorizability conditions has associated to it in a natural way a Hopf algebra object in a suitable tensor category. We also show that all objects in the tensor category have the structure of left-left crossed bimodules over the Hopf algebra object. For 4D factorizable topological quantum filed theories, we provide by analogous methods a construction of a Hopf algebra category.
CORRELATION AND FLUCTUATION IN MULTIPARTICLE PRODUCTION: SOME CLOSING REMARKS

General comments are made on the evolution of this series of workshops and on some features of this particular workshop without attempting to summarize all the talks presented.
New lupane triterpenoids from Solidago canadensis that inhibit the lyase activity of DNA polymerase β

Bioassay-directed fractionation of a methyl ethyl ketone extract of Solidago canadensis L. (Asteraceae), using an assay to detect the lyase activity of DNA polymerase beta, resulted in the isolation of the four new lupane triterpenoids 1-4 and the seven known compounds lupeol, lupeyl acetate, ursolic acid, cycloartenol, cycloartenyl palmitate, alpha-amyrin acetate, and stigmasterol. The structures of the new compounds were established as 3beta-(3R-acetoxyhexadecanoyloxy)-lup-20(29)-ene (1), 3beta-(3-ketohexadecanoyloxy)-lup-20(29)-ene (2), 3beta-(3R-acetoxyhexadecanoyloxy)-29-nor-lupan-20-one (3), and 3beta-(3-hetohexadecanoyloxy)-29-nor-lupan-20-one (4), respectively, on the basis of extensive 1D and 2D NMR spectroscopic interpretation and chemical modification studies. All 11 compounds were inhibitory to the lyase activity of DNA polymerase beta.
Sound Radiation From Beams Under the Action of Moving Line Forces

The topic of sound radiation from beams under the action of harmonic line forces moving at subsonic speeds (M 1, respectively) due to the effects of the Doppler shif...
Enantioselective Total Syntheses of (−)-Taiwaniaquinone H and (−)-Taiwaniaquinol B by Iridium-Catalyzed Borylation and Palladium-Catalyzed Asymmetric α-Arylation

We report a concise, enantioselective total synthesis of (−)-taiwaniaquinone H and the first enantioselective total synthesis of (−)-taiwaniaquinol B by a route that includes asymmetric palladium-catalyzed α-arylation of a ketone with an aryl bromide that was generated by sterically controlled halogenation via iridium-catalyzed C−H borylation. This asymmetric α-arylation creates the benzylic quaternary stereogenic center present in the taiwaniaquinoids. The synthesis was completed efficiently by developing a Lewis acid-promoted cascade to construct the [6,5,6] tricyclic core of an intermediate common to the synthesis of a number of taiwaniaquinoids. Through the preparation of these compounds, we demonstrate the utility of constructing benzylic quaternary stereogenic centers, even those lacking a carbonyl group in the α-position, by asymmetric α-arylation.
Deep electromagnetic sounding in central Nevada

Sixteen shallow and deep controlled source electromagnetic soundings were performed in Buena Vista Valley, near Winnemucca, Nevada, to investigate an intra-basement conductor previously detected with magnetotellurics. The survey was carried out with the LBL EM-60 system using a remote magnetic reference for low-frequency geomagnetic noise cancellation, 100-m- and 2.8-km-diameter transmitter loops, and a minicomputer for in-field processing. EM soundings were made at distances from 0.5 to 30 km from three loops over the frequency range 0.02 to 500 Hz. Data were interpreted by means of 1-D inversions and the resulting layered models were pieced together to yield an approximate 2-D geoelectric model along the N-S axis of the valley. The EM soundings and one MT sounding show a 3 to 7 ohm-m zone at a depth of four to seven km. The conductor appears to be deepest at the northern end of the valley and shallowest beneath a basement ridge that seems to divide Buena Vista Valley into two basinal structures. Similar intra-basement conductors are also reported 50 to 75 miles south in the Carson Sink-Fallon areas, suggesting a common source, probably related to an anomalously hot, thin crust.
Catalytic activity of carboxypeptidase B and of carboxypeptidase Y with anisylazoformyl substrates.

Abstract Anisylazoformyllysine (CH 3 OC 6 H 4 NNCO-Lys-OH) is rapidly hydrolyzed at the acyl-lysine linkage by the zinc-enzyme porcine carboxypeptidase B. The catalytic reaction is readily monitored spectro-photometrically by disappearance of the intense absorption (348.5 nm, e 18400) of the azo chromophore, which chemically fragments after substrate cleavage. Carboxypeptidase Y has no activity toward this type of substrate.
A multi-dimensional scheme for controlling unstable periodic orbits in chaotic systems

Abstract The control of unstable periodic orbits (UPOs) in chaotic systems is herein investigated by applying a weighted sum of external periodic inputs. These inputs are drawn from a “generic” set of basis functions and used to stabilize different UPOs in a chaotic attractor. All parameters associated with this multi-dimensional control scheme are experimentally computed without a priori knowledge of the system, thus making it easily applicable to a wide variety of dynamical systems. The performance of this control scheme is illustrated with several well-established chaotic systems.
Fault type predictions from stress distributions on planetary surfaces: Importance of fault initiation depth

The prediction of fault type on planetary surfaces from model stresses calculated at depth is discussed. These fault-type predictions yield different faults than those predicted using the surface criteria commonly employed in geophysical models. For elastic-plate flexure models of mascon loading on the moon, stresses calculated at the surface predict the occurrence of strike-slip faulting at the radial distance where grabens are found. Normal faults bounding lunar grabens and thrust faults responsible for wrinkle ridges are analyzed. It is found that the former initiate at the mechanical discontinuity that separates the breccia of the megaregolith from in situ fractured rock and that the latter initiate at the mechanical discontinuity between basalt layers and the underlying basin floor. The difference between elastic constants for the outer few kilometers of brecciated megaregolith and the underlying lunar lithosphere are evaluated. Superposing nonisotropic stresses resulting from the weight of overburden to the depth of the relevant mechanical discontinuity yield stresses that predict wrinkle ridges in the basin centers and grabens outside the basin margin, and eliminate the predicted zone of strike-slip faults.
Moment aberration projection for nonregular fractional factorial designs

Nonregular fractional factorial designs, such as Plackett–Burman designs, are widely used in industrial experiments for run size economy and flexibility. A novel criterion, called moment aberration projection, is proposed to rank and classify nonregular designs. It measures the goodness of a design through moments of the number of coincidences between the rows of its projection designs. The new criterion is used to rank and classify designs of 16, 20, and 27 runs. Examples are given to illustrate that the ranking of designs is supported by other design criteria.
Discrete Extremal Length and Cube Tilings in Finite Dimensions

Extremal length is a conformal invariant that transfers naturally to the discrete setting, giving square tilings as a natural combinatorial analog of conformal mappings. Recent work by S. Hersonsky has explored generalizing these ideas to three-dimensional cube tilings. The connections between discrete extremal length and cube tilings survive the dimension jump, but a condition called the triple intersection property is needed to generalize existence arguments. We show that this condition is too strong to realize a tiling, thus showing that discrete conformal mappings are far more limited in dimension three, mirroring the classical phenomenon. We also generalize results about discrete extremal length beyond dimension three and introduce some necessary conditions for cube tilings.
Prior-Free Probabilistic Prediction of Future Observations

Prediction of future observations is a fundamental problem in statistics. Here we present a general approach based on the recently developed inferential model (IM) framework. We employ an IM-based technique to marginalize out the unknown parameters, yielding prior-free probabilistic prediction of future observables. Verifiable sufficient conditions are given for validity of our IM for prediction, and a variety of examples demonstrate the proposed method’s performance. Thanks to its generality and ease of implementation, we expect that our IM-based method for prediction will be a useful tool for practitioners. Supplementary materials for this article are available online.
Control of a coupled two-spin system without hard pulses

Constructive techniques for preparing a specific unitary generator from a coupled two-spin system, via bounded amplitude radio frequency selective single spin pulses, are presented. The frequency of any pulse in the sequence is one of the two Larmor frequencies, while the phase takes one of two values. The fact that the amplitude is bounded implies that the Larmor frequency separation between the two spins need not be large to maintain selectivity. In addition, the contribution of the J coupling term to single spin evolution is not neglected, but instead plays a crucial role. The procedure is based on a certain decomposition of SU(4) available in the literature. A method for determining the parameters entering this factorization, in terms of the entries of the target unitary generator, is also provided.
Ballooning Instability in Polar Caps of Accreting Neutron Stars

We assess the stability of Kruskal-Schwarzschild (magnetic Rayleigh-Taylor) type modes for accreted matter on the surface of a neutron star confined by a strong (1012 G) magnetic field. Employing the energy principle to analyze the stability of short-wavelength ballooning modes, we find that line-tying to the neutron star crust stabilizes these modes until the overpressure at the top of the neutron star crust exceeds the magnetic pressure by a factor ~8(a/h), where a and h are, respectively, the lateral extent of the accretion region and the density scale height. The most unstable modes are localized within a density scale height above the crust. We calculate the amount of mass that can be accumulated at the polar cap before the onset of instability.