cssi/SciSciGPT-SciSciNet huggingface dataset:
Fluorinated building blocks. The discovery of a stable difluoroallenyl indium and the synthesis of gem-difluoroallenyl and -propargyl synthons in aqueous media

The synthesis of two highly functional fluorinated motifs, TIPS−C⋮C−CF2−, and CF2CC(TIPS)− is described. This approach is mediated by a room-temperature stable ethereal solution of a difluoroallene indium intermediate. This intermediate may be used as “stock solution” in the reaction with aqueous HCHO, to yield CF2CC(TIPS)CH2OH, and in a reaction with a Schiff base to produce the corresponding β,β-difluorohomopropargylamine. The synthetic potential of CF2CC(TIPS)CH2OH has been demonstrated by its conversion to a difluorodihydrofuran derivative by a facile and efficient 5-endo-trig cyclization. Homopropargylic gem-difluoro alcohols are synthesized by addition of indium to a mixture of an aldehyde and TIPS−C⋮C−CF2Br in predominantly aqueous media.
Minijet initial conditions for non-equilibrium parton evolution at RHIC and LHC

Abstract An important ingredient for the non-equilibrium evolution of partons at RHIC and LHC is to have some physically reasonable initial conditions for the single particle phase space distribution functions for the partons. We consider several plausible parametrizations of initial conditions for the single particle distribution function fi(x,p) and fix the parameters by matching ∫f(x,p)p μ dσ μ to the invariant momentum space semi-hard parton distributions obtained using perturbative QCD (pQCD), as well as fitting low order moments of the distribution function. We consider parametrizations of fi(x,p) with both boost invariant and boost non-invariant assumptions. We determine the initial number density, energy density and the corresponding (effective) temperature of the minijet plasma at RHIC and LHC energies. For a boost non-invariant minijet phase-space distribution function we obtain ∼30(140)/fm3 as the initial number density, ∼50(520) GeV/fm3 as the initial energy density and ∼520(930) MeV as the corresponding initial effective temperature at RHIC(LHC).
An Ab Initio Study of Potential Energy Surfaces for N8 Isomers

The potential energy surfaces and the nature of transition structures for the decomposition of three N8 isomers (octaazapentalene, azidopentazole, and diazidodiimide) into 4 N2 are investigated using ab initio methods. These isomers are all high-energy species, relative to molecular nitrogen, but are much lower in energy than the previously studied cubic structure. Second-order perturbation theory (MP2) predicts that the dissociation of octaazapentalene proceeds via isomerization to a linear molecule. The dissociation reaction of azidopentazole prefers ring breaking, at a cost of less than 20 kcal/mol, to breaking a bond in the side chain. The cis isomer of diazidodiimide is found to be slightly more stable than that of the trans isomer at the highest levels of theory used here. The coupled cluster (CCSD(T)) diazidodiimide dissociation barrier is computed to be about 20 kcal/mol. This barrier is only marginally sufficient to make this high energy density molecule metastable.
Reducing the Risk at Small Community Banks: Is it Size or Geographic Diversification that Matters?*

Most community banks face relatively high levels of diversifiable credit risk because they have relatively few loan customers (idiosyncratic risk) and are not geographically diversified (local market risk). We simulate mergers among community banks to quantify the relative contributions of idiosyncratic risk and local market risk to the default risk assumed by community banks. We find that the greatest risk-reduction benefits are achieved by increasing a community bank’s size, regardless of where the expansion takes place. We interpret this result as evidence that idiosyncratic risk dominates local market risk, especially at rural banks. Community banks face enormous pressure to grow, yet the pressure to geographically diversify is limited. As a consequence, larger community banks are likely to replace smaller community banks, but their focus on relationship lending will not disappear.
Down‐regulation of protein kinase C isoforms in irritant contact dermatitis

Protein kinase C (PKC) isoforms are important in cell signal transduction associated with regulation of cell proliferation and differentiation. In this study, alterations of PKC isoform levels in irritant patch test reactions were detected by Western immunoblots. 4 chemically and structurally different irritants, 4% and 8% hydrochloric acid (HCl); 1% and 2% sodium hydroxide (NaOH); 20% and 40% nonanoic acid (NON) in 1-propanol; and 5% and 10% sodium dodecyl sulfate (SDS) were applied on the backs of mice in Finn Chambers and fixed with surgical dressings. The patches were kept on the skin for 24 h and removed. 24 h after removal, mild erythema with thickening of skin without vesicles was observed in all irritated skin, except that 4% HCl and 1% NaOH treated skin showed unremarkable skin reaction. No visible skin reaction was detected in vehicle-treated skin. PKC isoform alpha, beta, gamma, and delta levels in irritated skin revealed a 10% to 65% decrease compared to vehicle treated skin. These results indicate that in HCl, NaOH, NON and SDS-induced irritation, activation of the PKC related cell signal transduction cascade may be involved, and that PKC mediated events may be a common phenomenon in irritant contact dermatitis.
Assessment of vitamin D status and definition of a normal circulating range of 25-hydroxyvitamin D

Purpose of review The assessment of circulating 25-hydroxyvitamin D [25(OH)D] for clinical diagnosis has increased in an exponential fashion during the past 5 years. It is thus timely to review the reasons for this increase as well as the diverse analytical methods used to meet this need. Recent findings Nutritional vitamin D status, as defined by circulating levels of 25(OH)D, has long been implicated in skeletal health. However, in the past decade circulating 25(OH)D has been strongly linked in humans to cancer rates, autoimmune disease, cardiovascular health and infectious disease. As a result, availability and rapid analytical turnaround of 25(OH)D assays have had to improve. Today these demands are largely met in the clinical laboratory by direct automated chemiluminescent platform analysis or high-throughput LC/MS procedures. These methods are diverse and often do not agree with respect to designated reference ranges. Summary The assessment of circulating 25(OH)D levels has become an important clinical tool in the management and prevention of diverse disease states. For this reason, assay standardization as well as a uniform reference range for circulating 25(OH)D levels must be achieved.
Secondhand Smoke Exposure, Parental Depressive Symptoms and Preschool Behavioral Outcomes

Little is known about the association of secondhand smoke (SHS) exposure and behavioral conditions among preschoolers. A cross-sectional analysis was used to examine billing and pharmacy claims from November 2004 to June 2012 linked to medical encounter-level data for 2,441 children from four pediatric community health clinics. Exposure to SHS was associated with attention deficit-hyperactivity disorder/ADHD and disruptive behavior disorder/DBD after adjusting for potential confounding factors. Assessment of exposure to SHS and parental depressive symptoms in early childhood may increase providers' ability to identify children at higher risk of behavioral issues and provide intervention at the earliest stages.
A STANDARD-TO-BLOWOUT JET

The commonly observed jets provide critical information on the small-scale energy release in the solar atmosphere. We report a near disk-center jet on 2010 July 20, observed by the Solar Dynamics Observatory. In this event, the standard interchange magnetic reconnection between an emerging flux spanning 9 × 103 km and ambient open fields is followed by a blowout-like eruption. In the standard stage, as the emerging negative element approached the nearby positive network fields, a jet with a dome-like base in EUV grew for 30 minutes before the jet spire began to migrate laterally with enhanced flux emergence. In the blowout stage, the above converging fields collided and the subsequent cancellation produced a UV microflare lasting seven minutes, in which the dome of the jet seemed to be blown out as (1) the spire swung faster and exhibited an unwinding motion before vanishing, (2) a rising loop and a blob erupted leaving behind cusped structures, with the blob spiraling outward in acceleration after the flare maximum, and (3) ejecting material with a curtain-like structure at chromospheric to transition-region temperatures also underwent a transverse motion. It is thus suggested that the flare reconnection rapidly removes the outer fields of the emerging flux to allow its twisted core field to erupt, a scenario favoring the jet-scale magnetic breakout model as recently advocated by Moore et al. in 2010.
Coherence and entanglement in two-qubit dynamics: interplay of the induced exchange interaction and quantum noise due to thermal bosonic environment

We present a review of our recent results for the comparative evaluation of the induced exchange interaction and quantum noise mediated by the bosonic environment in two-qubit systems. We report new calculations for P-donor-electron spins in Si-Ge type materials. Challenges and open problems are discussed.
On a free group of transformations defined by an automaton

We prove that three automorphisms of the rooted binary tree defined by a certain 3-state automaton generate a free non-Abelian group of rank 3.
Expedient synthesis of α-substituted fluoroethenes.

A mild and efficient synthesis of 1-aryl-1-fluoroethenes from benzothiazolyl (aryl)fluoromethyl sulfones and paraformaldehyde, under DBU- or Cs2CO3-mediated conditions at room temperature, is described. A comparable diethyl fluoro(naphthalen-2-yl)methylphosphonate reagent does not react with paraformaldehyde under these mild conditions. The utility of the methodology for synthesis of terminal α-fluoroalkenes bearing electron-withdrawing functionalities is also shown.
Constructing consistent fuzzy surfaces from fuzzy data

Given fuzzy data describing a three-dimensional entity such as terrain, we develop methods to construct surfaces that are consistent with the uncertainty in the data and surface model itself. In particular, surfaces generated from higher α-cut values of the fuzzy data are contained within the surfaces generated by lower α-cut values of the fuzzy data. Moreover, the smoothness and continuity conditions of the surface generating method is maintained by each level surface. We demonstrate the ideas by developing two- and three-dimensional surfaces from fuzzy data for cubic splines and digital terrain models generated from triangulation.
Generation of arbitrary Dicke states in spinor Bose–Einstein condensates

We demonstrate that the combination of two-body collisions and applied Rabi pulses makes it possible to prepare arbitrary Dicke (spin) states as well as maximally entangled states by appropriate sequencing of external fields.
Knowledge-based method for fully automatic contour detection in radiographs

Identification of anatomical structure boundaries in radiographs is a necessary step for detecting abnormalities. The aim of this study is to develop a knowledge-based approach to automatically segment the interested structure boundaries in X-ray images. Our method contains four main steps. First, the original gray-level radiograph is segmented into a binary image. Second, the region of interest (ROI) is detected by matching the features extracted from the binary image with a pre-defined anatomical model, and the location of ROI will serve as the landmark for the following search. Third, an anatomical model will be hierarchically applied to the original image. Correlation values and anatomical constraints will be applied to choose the closer match edge candidates. According to the shape of the global model, the best match edge candidates will be selected and connected to generate the boundaries of the interested structure. Finally, active contour model is used to refine the boundaries. The results show the effectiveness and the efficiency of this proposed method.
Economic Structure, the Exchange Rate, and Adjustment in the Federal Republic of Germany: A General Equilibrium Approach

The effects of an appreciation of the deutsche mark are traced with the help of a computable general equilibrium model under alternative structural policy scenarios. In the first scenario, characterized by severe structural rigidities, the contractionary effects of exchange rate appreciation dominate the expansionary effects, so that gross domestic product and employment fall and the external surplus declines only slightly. In the alternative case of free movement of goods, services, and factors, the expansionary effects of the appreciation become more prominent as supply and demand respond much more readily to the relative price changes.
Predicting Which Older Adults Will or Will Not Fall Using the Fullerton Advanced Balance Scale

Abstract Hernandez D, Rose DJ. Predicting which older adults will or will not fall using the Fullerton Advanced Balance Scale. Objective The purpose of this study was to determine if the Fullerton Advanced Balance (FAB) scale can predict faller status in a group of independently functioning older adults. Design A cross-sectional design was used to establish the sensitivity and specificity of the FAB scale to predict faller status based on a retrospective self-reported fall history. For the purpose of this study, a faller was classified as an older adult with a history of 2 or more falls in the previous 12 months. Setting Multipurpose senior centers in an urban community. Participants A sample of independently functioning older adults (N=192; mean age ± SD, 77±6.5y). Interventions Not applicable. Main Outcome Measures FAB scale, a retrospective history of falls. Results Binary logistic regression analysis indicated that the total FAB scale score could be used to predict faller status (as determined by a retrospective self-reported fall history). In the present sample, the probability of falling increased by 8% with each 1-point decrease in total FAB scale score. Receiver operating characteristic analysis determined that a cut-off score of 25 out of 40 on the FAB scale produced the highest sensitivity (74.6%) and specificity (52.6%) in predicting faller status. Five individual test items on the FAB scale were particularly predictive of faller status and could be combined to form a short version of the scale that may be even more predictive of faller status and require less time to administer. Conclusions The FAB scale is a predictive measure of faller status when used with independently functioning older adults. A practitioner can be confident in more than 7 out of 10 cases that an older adult who scores 25 or lower on the FAB scale is at high risk for falls and in need of immediate intervention.
Spectrum and decay matrix elements of B and D-mesons in lattice NRQCD

We discuss recent results on the excitation spectra of B and D-mesons obtained in the framework of non-relativistic lattice QCD in the quenched approximation. The results allow for the determination of the MS-mass of mb,MS(mb,MS) = 4.34(7) GeV in O(α3s) in the perturbative matching. The determination of the decay constants fBs and fDs, is discussed in detail. Results for the matrix elements of semi-leptonic B to D decays are shown.
Locally Repairable Codes

Distributed storage systems for large-scale applications typically use replication for reliability. Recently, erasure codes were used to reduce the large storage overhead, while increasing data reliability. A main limitation of off-the-shelf erasure codes is their high-repair cost during single node failure events. A major open problem in this area has been the design of codes that: 1) are repair efficient and 2) achieve arbitrarily high data rates. In this paper, we explore the repair metric of locality, which corresponds to the number of disk accesses required during a single node repair. Under this metric, we characterize an information theoretic tradeoff that binds together the locality, code distance, and storage capacity of each node. We show the existence of optimal locally repairable codes (LRCs) that achieve this tradeoff. The achievability proof uses a locality aware flow-graph gadget, which leads to a randomized code construction. Finally, we present an optimal and explicit LRC that achieves arbitrarily high data rates. Our locality optimal construction is based on simple combinations of Reed-Solomon blocks.
Concerning the diastereofacial selectivity of aldol reactions of chiral methyl ketone enolates : evidence for remote chelation in the bafilomycin aldol reaction

Abstract Evidence is presented that the aldol reactions of the lithium enolates of 4 and 7 proceed preferentially by way of chelated transition structure 19.
Modeling the flow of complex fluids through heterogeneous channels

Computational modeling of the driven flow of multi-component fluids past chemically, physically and thermally heterogeneous substrates can provide insight into a variety of processes, from flow in microfluidic devices to polymer processing in reaction chambers. One of the challenges in modeling these systems is capturing the close interplay between hydrodynamics and thermodynamics. The lattice Boltzmann method (LBM) provides a computationally efficient method for carrying out such investigations. We review recent studies using the LBM to examine the flow of partially miscible binary fluids through channels that contain chemically, topographically or thermally patterned substrates. The findings highlight how the substrates can be modified to yield the required behavior at fluid/surface and fluid/fluid interfaces and consequently, the desired macroscopic properties. Specifically, the results provide guidelines for optimizing processes in microfluidic devices and in creating microemulsions with well-controlled morphologies. The studies also reveal new phenomena that arise from the interplay between flowing complex fluids and chemically, physically and thermally patterned confining walls.
What Is Electricity

This address,1 tracing the interesting history and significance of the many concepts of electricity as they have evolved from an indefinite beginning through the extremely rapid developments of the current century toward a speculative future, is republished here at the request of the Institute's committee on education.
Utilization Of An Image Orthicon System For Radiometric Measurements

Evaluation of the radiometric capability of an S-10 image orthicon system, used for quantitative radiation measurements against re-entry vehicles, has been completed.
Wikis in the Classroom: Faculty and Student Perspective.

In March 2009, a faculty member and four political science students led a forum entitled “Wikis in the Classroom: Student and Faculty Perspective.” The discussion centered on a number of benefits and concerns with the use of wikis as an instructional tool within the classroom. Based on student and faculty feedback, this article expands on four themes that emerged from the roundtable discussion: training, applicability of assignments, setting clear guidelines, and expectations and grading.
Infrared and X-Ray Spectroscopy of the Kes 75 Supernova Remnant Shell: Characterizing the Dust and Gas Properties

We present deep Chandra observations and Spitzer Space Telescope infrared (IR) spectroscopy of the shell in the composite supernova remnant (SNR) Kes 75 (G29.7-0.3). The remnant is composed of a central pulsar wind nebula and a bright partial shell in the south that is visible at radio, IR, and X-ray wavelengths. The X-ray emission can be modeled by either a single thermal component with a temperature of approx 1.5 keV, or with two thermal components with temperatures of 1.5 and 0.2 keY. Previous studies suggest that the hot component may originate from reverse-shocked SN ejecta. However, our new analysis shows no definitive evidence for enhanced abundances of Si, S, Ar, Mg, and Fe, as expected from supernova (SN) ejecta, or for the IR spectral signatures characteristic of confirmed SN condensed dust, thus favoring a circumstellar or interstellar origin for the X-ray and IR emission. The X-ray and IR emission in the shell are spatially correlated, suggesting that the dust particles are collisionally heated by the X-ray emitting gas. The IR spectrum of the shell is dominated by continuum emission from dust with little, or no line emission. Modeling the IR spectrum shows that the dust is heated to a temperature of approx 140 K by a relatively dense, hot plasma, that also gives rise to the hot X-ray emission component. The density inferred from the IR emission is significantly higher than the density inferred from the X-ray models, suggesting a low filling factor for this X-ray emitting gas. The total mass of the warm dust component is at least 1.3 x 10(exp -2) Solar Mass, assuming no significant dust destruction has occurred in the shell. The IR data also reveal the presence of an additional plasma component with a cooler temperature, consistent with the 0.2 keV gas component. Our IR analysis therefore provides an independent verification of the cooler component of the X-ray emission. The complementary analyses of the X-ray and IR emission provide quantitative estimates of density and filling factors of the clumpy medium swept up by the SNR.
Grignard-mediated synthesis and preliminary biological evaluation of novel 3-substituted farnesyl diphosphate analogues.

Abstract A series of substituents was installed at the 3 position of farnesyl diphosphate through a copper-cyanide mediated coupling of a vinyl triflate with various Grignard reagents. These novel FPP mimetics were then evaluated as inhibitors of or substrates for mammalian protein farnesyl transferase. The IC 50 values for these compounds range from 18 to 10,100 nm, with the 3-isopropenyl analogue being one of the most potent FPP-mimetic mFTase inhibitors yet synthesized. ©2000 Elsevier Science Ltd. All rights reserved.
Rb2Au6Sb4S10: a novel sulfosalt with two different interpenetrating anionic frameworks: [Au3Sb4S8]– and [Au3S2]–

The layered compound Rb2Au6Sb4S10 consisting of two interpenetrating [Au3Sb4S8]– and [Au3S2]– frameworks was prepared from the reaction of Au with a polythioantimonate flux.
Spacecraft Attitude Estimation Using Adaptive Gaussian Sum Filter

This paper is concerned with improving the attitude estimation accuracy by implementing an adaptive Gaussian sum filter where the a posteriori density function is approximated by a sum of Gaussian density functions. Compared to the traditional Gaussian sum filter, this adaptive approach utilizes the Fokker-Planck-Kolmogorov residual minimization to update the weights associated with different components of the Gaussian mixture model. Updating the weights provides an accurate approximation of the a posteriori density function and thus superior estimates. Simulation results show that updating the weights during the propagation stage not only provides better estimates between the observations but also provides superior estimator performance where the measurements are ambiguous.
An Improved Procedure for the Preparation of the O,2-Dianion of Allyl Alcohol

Abstract An improved procedure for the preparation of the O,2-dianion of allyl alcohol is described. The use of the magnesium alkoxide of 2-bromopropen-1-ol instead of the known lithium salt, suppresses dehydrohalogenation upon treatment with tert-butyl lithium and furnishes the dianion. Addition of this dianion to a variety of carbonyl compounds affords the expected products in good yield.
Multiplicities of conjugacy class sizes of finite groups

Abstract It has been proved recently by Moreto (2007) [8] and Craven (2008) [3] that the order of a finite group is bounded in terms of the largest multiplicity of its irreducible character degrees. A conjugacy class version of this result was proved for solvable groups by Jaikin-Zapirain (2005) [7] . In this note, we prove that if G is a finite simple group then the order of G , denoted by | G | , is bounded in terms of the largest multiplicity of its conjugacy class sizes. As a consequence, we prove that if the largest multiplicity of conjugacy class sizes of any quotient of a finite group G is m , then | G | is bounded in terms of m .
Can Light Echoes Account for the Slow Decay of Type IIn Supernovae

The spectra of Type IIn supernovae indicate the presence of a preexisting slow, dense circumstellar wind (CSW). If the CSW extends sufficiently far from the progenitor star, then dust formation should occur in the wind. The light from the supernova explosion will scatter off this dust and produce a light echo. Continuum emission seen after the peak will have contributions from both this echo as well as from the shock of the ejecta colliding with the CSW, with a fundamental question of which source dominates the continuum. We calculate the brightness of the light echo as a function of time for a range of dust shell geometries and use our calculations to fit to the light curves of SN 1988Z and SN 1997ab, the two slowest declining Type IIn supernovae on record. We find that the light curves of both objects can be reproduced by the echo model. However, their rate of decay from peak, color at peak, and observed peak absolute magnitudes when considered together are inconsistent with the echo model. Furthermore, when the observed values of MB are corrected for the effects of dust scattering, the values obtained imply that these supernovae have unrealistically high luminosities. We conclude that light echoes cannot properly account for the slow decline seen in some Type IIn supernovae and that the shock interaction is likely to dominate the continuum emission.
Mechanisms and interactions in testicular steroidogenesis and prostaglandin synthesis

Abstract Prostaglandin synthesis by rat testicular tissue was observed to be gonadotrophin and adrenal dependent, and to have the same distribution in the gonad as the steroidogenic enzymes. The synthesis was increased by 5-HT, but decreased by melatonin. Lipid peroxidation increases with age, FSH treament, linoleic and arachidonic acid and melatonin, but was decreased by serotonin, c-AMP, LH, prolactin and ephinephrine. Testicular lysosomes were labilized by LH, adrenal demedullation, testosterone, Vit. A and acetylcholine, but were stabilized by c-AMP, epinephrine and cortisol. Contractility of rat seminiferous tubules was observed to be prostaglandin dependent, stimulated by 5-HT, and inhibited by melatonin and c-AMP. Evidence was obtained indicating that a phospholipase A2 is present in rat testicular lysosomes, and that it is liberated by radiation, heat or certain chemicals. This enzyme hydrolyses PUFA from membrane phospholipids, the former of which are converted into prostaglandins. The prostaglandins appear to initially stimulate contractility of seminiferous tubules, but at higher concentrations they stimulate adenyl cyclase, which increases c-AMP levels in the tubules thereby inhibiting contractility and cellular division. The process of prostaglandin synthesis also produced malonaldehyde, and endoperoxides that contribute to alterations in steroidogenesis by Schiff's base formation and to cellular lysis by membrane permeability changes. Prostaglandins appear to be synthesized physiologically from PUFA derived from cholesterol esters, but pathologically in much larger quantities from membrane phospholipids. Prostaglandins apparently inhibit androgen synthesis by their effects on cholesterol esterase and other steroidogenic enzymes rather than by changing blood flow.
ENERGY DEMAND AND MATERIALS FLOWS IN THE ECONOMY

Many forecasts show industrial energy use growing rapidly in industrial countries. These forecasts do not adequately take into account the diminishing importance of basic materials use in the economies of mature industrial societies, the emerging shift of production based on virgin materials to developing and resource-rich countries, and the increased recycling of materials. Since the processing of materials dominates industrial energy demand, this pattern of development will upset those forecasts. While energy use by industry will grow in such countries as China, Saudi Arabia. Korea, Canada, Brazil, Mexico, South Africa, and Australia, it will continue to decline or stagnate in the U.S., Europe, and Japan.
A model of first and second-best social security programs

This paper employs an overlapping generations model with output uncertainty to investigate how second-best social security schemes can be used to affect expected welfare. As with actual pension plans, our social security plan entails a proportional tax on earned income but provides a rebate that is not directly proportional with that individual's contributions. Thus, under certainty, the plan distorts the labor/leisure choice and lowers welfare. However, we prove that with uncertainty a range of such plans exist which raise expected welfare because it enhances intergenerational risk sharing. Using Monte Carlo experiments we derive the characteristics of the optimal second best plan.
Phosphine Catalyzed α-Arylation of Enones and Enals Using Hypervalent Bismuth Reagents: Regiospecific Enolate Arylation via Nucleophilic Catalysis

Exposure of enones and enals to 20 mol % tributylphosphine in the presence of triarylbismuth(V) dichlorides results in regiospecific aryl transfer to the α-position of the enone or enal pronucleophile. These results represent the first examples of enolate arylation under the conditions of nucleophilic catalysis.
Perturbation theory for fat-link fermion actions

We discuss weak coupling perturbation theory for lattice actions in which the fermions couple to smeared gauge links. The normally large integrals that appear in lattice perturbation theory are drastically reduced. Even without detailed calculation, it is easy to determine to good accuracy the scale of the logarithms that appear in cases where an anomalous dimension is present. We describe several 1-loop examples for fat-link Wilson and clover fermions. including the additive mass shift, the relation between the lattice and MS quark masses, and the axial current renormalization factor (ZA) for light-light and static-light currents.
Bifurcation and chaos in friction-induced vibration

Abstract Friction-induced vibration is a phenomenon that has received extensive study by the dynamics community. This is because of the important industrial relevance and the ever-evolving development of new friction models. In this paper, we report the result of bifurcation study of a single-degree-of-freedom mechanical oscillator sliding over a surface. The friction model we use is that developed by Canudas de Wit et al., a model that is receiving increasing acceptance from the mechanics community. Using this model, we find a stable limit cycle at intermediate sliding speed for a single-degree-of-freedom mechanical oscillator. Moreover, the mechanical oscillator can exhibit chaotic motions. For certain parameters, numerical simulation suggests the existence of a Silnikov homoclinic orbit. This is not expected in a single-degree-of-freedom system. The occurrence of chaos becomes possible because the friction model contains one internal variable. This demonstrates a unique characteristic of the friction model. Unlike most friction models, the present model is capable of simultaneously modeling self-excitation and predicting stick–slip at very low sliding speed as well.
Structural dynamic analysis on a parallel computer: the finite element machine

Abstract The development of general-purpose finite element computer software systems has provided the capability to analyze a wide range of linear and non-linear structural problems. However, these software systems are severely limited for non-linear response calculations because of the available speed on current sequential computers. Recent and projected advances in parallel multiple instruction multiple data (MIMD) computers provide an opportunity for significant gains in computing speed and for broadening the range of structural problems which may be solved. The key to these gains is the effective selection and implementation of algorithms which exploit parallel computing. This paper documents experiences solving transient response calculations on an experimental MIMD computer, termed the Finite Element Machine. The paper describes the algorithm used, its implementation for parallel computations, and results for representative one- and two-dimensional dynamic response test problems. The results show computation speedups of up to 7.83 for eight processors, and indicate that significant speedups of solution time are possible for non-linear dynamic response calculations through the use of many processors and appropriate parallel integration algorithms. The results are extremely encouraging and suggest that significant speedups in structural computations can be achieved through advances in parallel computers.
Packing Ferrers Shapes

Answering a question of Wilf, we show that, if n is sufficiently large, then one cannot cover an n × p(n) rectangle using each of the p(n) distinct Ferrers shapes of size n exactly once. Moreover, the maximum number of pairwise distinct, non-overlapping Ferrers shapes that can be packed in such a rectangle is only Θ(p(n)/log n):
Galaxy orbits and the intracluster gas temperature in clusters

In this paper, we examine how well galaxies and intracluster gas trace the gravitational potential of clusters. Utilizing mass profiles derived from gravitational lensing and X-ray observations, coupled with measured galaxy velocities, we solve for the velocity anisotropy parameter β_(orb)(r) using the anisotropic Jeans equation. This is done for five clusters, three at low redshift: A2199, A496 and A576 and two at high redshifts: A2390 and MS1358. We use X-ray temperature profiles obtained from Chandra and ASCA/ROSAT data to estimate β_X(r), the ratio of energy in the galaxies compared to the X-ray gas. We find that none of these clusters is strictly in hydrostatic equilibrium. We compare the properties of our sample with clusters that form in high-resolution cosmological N-body simulations that include baryonic physics. Simulations and data show considerable scatter in their β_(orb)(r) and β_X(r) profiles. We demonstrate the future feasibility and potential for directly comparing the orbital structure of clusters inferred from multiwavelength observations with high-resolution simulated clusters.
Lessons for Government Adoption of Open Standards: A Case Study of the Massachusetts Policy

ABSTRACT This article chronicles the historic process of Massachusetts becoming the first government to mandate an open standard for document formats. In 2005, Massachusetts mandated the use of the OpenDocument Format (ODF) as part of a transition to open standards. The article also analyzes the Massachusetts experience and develops a set of lessons learned. The first set of lessons includes a focus on the difficulties of being an early adopter and factors that influenced the adoption mandate. Governments seeking to mandate specific document formats need to be aware of these factors. A second set of lessons focuses on decisions in establishing a standards policy. These lessons emphasize a clear definition of open standards, whether to mandate an open standard, and for government to carefully consider the expected benefits and costs of a standards policy. Overlooking costs, such as legacy equipment and training costs, can lead to disappointing results. These lessons are applicable, not only for decisions r...
Diffusion and conduction in a salt-free colloidal suspension via molecular dynamics simulations

Molecular dynamics (MD) simulations are used to determine the diffusion coefficients, electrophoretic mobilities and electrical conductivity of a charged colloidal suspension in the salt-free regime as a function of the colloid charge. The behavior of the colloidal particles' diffusion constant can be well understood in terms of two coupled effects: counterion ‘condensation’ and slowdown due to the relaxation effect. We find that the conductivity exhibits a maximum which approximately separates the regimes of counterion-dominated and colloid-dominated conduction. We analyze the electrophoretic mobilities and the conductivity in terms of commonly employed assumptions about the role of “free” and “condensed” counterions, and discuss different interpretations of this approach.
Generalizations of the familywise error rate

Consider the problem of simultaneously testing null hypotheses H 1, … H s . The usual approach to dealing with the multiplicity problem is to restrict attention to procedures that control the familywise error rate (FWER), the probability of even one false rejection. In many applications, particularly if s- is large, one might be willing to tolerate more than one false rejection provided the number of such cases is controlled, thereby increasing the ability of the procedure to detect false null hypotheses. This suggests replacing control of the FWER by controlling the probability of k or more false rejections, which we call the k-FWER. We derive both single-step and stepdown procedures that control the k-FWER, without making any assumptions concerning the dependence structure of the p-values of the individual tests. In particular, we derive a stepdown procedure that is quite simple to apply, and prove that it cannot be improved without violation of control of the k-FWER. We also consider the false discovery proportion (FDP) defined by the number of false rejections divided by the total number of rejections (defined to be 0 if there are no rejections). The false discovery rate proposed by Benjamini and Hochberg [J. Roy. Statist. Soc. Ser. B 57 (1995) 289–300] controls E(FDP). Here, we construct methods such that, for any γ and α, P{FDP > γ} ≤ α. Two stepdown methods are proposed. The first holds under mild conditions on the dependence structure of p-values, while the second is more conservative but holds without any dependence assumptions.
Global Attractors of Evolutionary Systems

An abstract framework for studying the asymptotic behavior of a dissipative evolutionary system \({\mathcal{E}}\) with respect to weak and strong topologies was introduced in Cheskidov and Foias (J Differ Equ 231:714–754, 2006) primarily to study the long-time behavior of the 3D Navier-Stokes equations (NSE) for which the existence of a semigroup of solution operators is not known. Each evolutionary system possesses a global attractor in the weak topology, but does not necessarily in the strong topology. In this paper we study the structure of a global attractor for an abstract evolutionary system, focusing on omega-limits and attracting, invariant, and quasi-invariant sets. We obtain weak and strong uniform tracking properties of omega-limits and global attractors. In addition, we discuss a trajectory attractor for an evolutionary system and derive a condition under which the convergence to the trajectory attractor is strong.
Coronal Element Abundances of the Post-Common Envelope Binary V471 Tauri with ASCA

We report on ASCA observations of the coronally active companion star in the post-common envelope binary V471 Tau. While it would be prudent to check the following results with grating spectroscopy, we find that a single-temperature plasma model does not fit the data. Two temperature models with variable abundances indicate that Fe is underabundant compared to the Hyades photospheric mean, whereas, the high first ionization potential element Ne is overabundant. This is indicative of the inverse first ionization effect, believed to result from the fractionation of ionized material by the magnetic field in the upper atmosphere of the star. Evolutionary calculations indicate that there should be no peculiar abundances on the companion star resulting from the common envelope epoch. Indeed, we find no evidence for peculiar abundances, although uncertainties are high.
Culture, Context, and the Taste for Redistribution

Is culture an important determinant of preferences for redistribution? To separate culture from the economic and institutional environment ("context"), we relate immigrants' redistributive preferences to the average preference in their birth countries. We find a strong positive relationship that is robust to rich controls for economic factors and cannot easily be explained by selective migration. This effect is as large as that of own household income and appears stronger for those less assimilated into the destination country. Immigrants from high-preference countries are more likely to vote for more pro-redistribution parties. The effect of culture persists strongly into the second generation. (JEL H23, Z13)
Localization and Metal-Insulator Transition in Multilayer Quantum Hall Structures

We study the phase structure and Hall conductance quantization in weakly coupled multilayer electron systems in the integer quantum Hall regime. We derive an effective field theory and perform a two-loop renormalization group calculation. It is shown that (i) finite interlayer tunnelings (however small) give rise to successive metallic and insulating phases and metal-insulator transitions in the unitary universality class; (ii) the Hall conductivity is not renormalized in the metallic phases in the 3D regime; and (iii) the Hall conductances are quantized in the insulating phases. In the bulk quantum Hall phases, the effective field theory describes the transport on the surface.
Simultaneous phase and frequency control of a three-phase Inductor-Convertor Bridge

The Inductor-Convertor Bridge (ICB) is a DC-AC-DC convertor network using gate controlled thyristers which allows controllable energy transfer between two superconducting coils. Since an ICB system is asynchronous, both phase and frequency are controllable. Simultaneous open-loop phase angle control and closed-loop frequency control has been analyzed and demonstrated on a three-phase model using two 4-H superconducting coils.
Development and validation of online models with parameter estimation for a building zone with VAV system

Abstract The energy consumption by building heating, ventilating, and air conditioning (HVAC) systems has evoked increasing attention to promote energy efficient control and operation of HVAC systems. Application of advanced control and operation strategies requires robust online system models. In this study, online models with parameter estimation for a building zone with a variable air volume system, which is one of the most common HVAC systems, are developed and validated using experimental data. Building zone temperature and zone entering air flow are modeled based on physical rules and only the measurements that are commonly available in a commercial building are used. Various validation experiments were performed using a real-building test facility to examine the prediction accuracies for system outputs. Using the online system models with parameter estimation, the prediction errors for all validation experiments are less than 0.28 °C for temperature outputs, and less than 84.9 m3/h for air flow outputs. The online models can be further used for local and supervisory control, as well as fault detection applications.
Total Internal Reflection Fluorescence for Adsorbed Probe Molecule Studies of Liquid/Solid Interfacial Environments:

Total internal reflection fluorescence (TIRF) is developed as a surface selective method to allow the environment of a liquid/solid interface to be probed by fluorescent molecules which are adsorbed from solution. The method has been used to detect pyrene sorbed to an octadecylsilane-derivatized fused-silica plate and resolve its spectral emission so that vibronic intensity ratios can be calculated and the surface environment characterized. Adsorption equilibria of the fluorescent probe to the surface and the depth of penetration of the evanescent excitation beam provide the basis for predicting interference from probe molecules in the solution phase. These predictions were validated by replacing the solution overlaying the alkylated silica interface with saturated vapor and comparing the apparent surface environments.
Coherently tunable third-order nonlinearity in a nanojunction

A possibility of tuning the phase of the third-order Kerr-type nonlinear susceptibility in a system consisting of two interacting metal nanospheres and a nonlinearly polarizable molecule is investigated theoretically and numerically. It is shown that by varying the relative inter-sphere separation, it is possible to tune the phase of the effective nonlinear susceptibility χ(3)(ω; ω, ω, − ω) in the whole range from 0 to 2π.
Ceramic Turbine Engine Demonstration Project: A summary report

Honeywell Engines, Systems & Services has successfully addressed critical concerns that are slowing commercialization of structural ceramics in gas turbines. The U.S. Department of Energy (DoE) sponsored Ceramic Turbine Engine Demonstration Project (CT-EDP) had the mission of advancing ceramic gas turbine component technology toward commercialization. The thrust of the program was to bridge the gap between ceramics in the laboratory and near-term commercial heat engine applications. Most of this mission has been achieved. The 331-200[CT] auxiliary power unit (APU) test bed featured ceramic first-stage nozzles and blades. Fabrication of ceramic components provided manufacturing process demonstration scale-up to the minimum levels needed for commercial viability. Through this program, design methods refinement and the development of new design methods unique to ceramic turbine components have been supported and validated in rig and development engine testing. Over 6800 hours of on-site endurance tests demonstrated component reliability. Additional field testing in APUs onboard commercial aircraft and stationary industrial engines has been initiated and will continue beyond completion of this program.
Weighted interlace polynomials

The interlace polynomials introduced by Arratia, Bollobas and Sorkin extend to invariants of graphs with vertex weights, and these weighted interlace polynomials have several novel properties. One novel property is a version of the fundamental three-term formula $\[ q(G)=q(G-a)+q(G^{ab}-b)+((x-1)^{2}-1)q(G^{ab}-a-b) \]$ that lacks the last term. It follows that interlace polynomial computations can be represented by binary trees rather than mixed binary–ternary trees. Binary computation trees provide a description of q(G) that is analogous to the activities description of the Tutte polynomial. If G is a tree or forest then these ‘algorithmic activities’ are associated with a certain kind of independent set in G. Three other novel properties are weighted pendant-twin reductions, which involve removing certain kinds of vertices from a graph and adjusting the weights of the remaining vertices in such a way that the interlace polynomials are unchanged. These reductions allow for smaller computation trees as they eliminate some branches. If a graph can be completely analysed using pendant-twin reductions, then its interlace polynomial can be calculated in polynomial time. An intuitively pleasing property is that graphs which can be constructed through graph substitutions have vertex-weighted interlace polynomials which can be obtained through algebraic substitutions.
Instabilities of hexagonal patterns with broken chiral symmetry

Abstract Three coupled Ginzburg–Landau equations for hexagonal patterns with broken chiral symmetry are investigated. They are relevant for the dynamics close to onset of rotating non-Boussinesq or surface-tension-driven convection. Steady and oscillatory, long- and short-wave instabilities of the hexagons are found. For the long-wave behavior coupled phase equations are derived. Numerical simulations of the Ginzburg–Landau equations indicate bistability between spatio-temporally chaotic patterns and stable steady hexagons. The chaotic state can, however, not be described properly with the Ginzburg–Landau equations.