cssi/SciSciGPT-SciSciNet huggingface dataset:
Cylindrical bending of unsymmetric composite laminates

tial number of eddies before decaying and that the modification for the interval preceeding the first multiple jump in the criterion, Eq. (7), is important in preventing unacceptable errors. For the most massive particle considered (dp = 100 jum; pp = 2500 kg/m), c0> At/T and c = c0 for all interactions. For practical application of the truncation criterion suggested in this technical note, it will certainly be necessary to first validate the criterion for the flow conditions of particular interest, as demonstrated herein for nearly homogeneous turbulent flow. Once established, however, the potential gains in efficiency, through elimination of unnecessary and redundant computational operations, may be significant.
Enantiopure Pyridine Bis(oxazoline) “Pybox” and Bis(oxazoline) “Box” Iron Dialkyl Complexes: Comparison to Bis(imino)pyridine Compounds and Application to Catalytic Hydrosilylation of Ketones

The chemistry of enantiopure pyridine bis(oxazoline) iron compounds has been explored. The electronic properties of this ligand class have been evaluated relative to aryl- and alkyl-substituted bis(imino)pyridines using cyclic voltammetry and CO stretching frequencies of iron dicarbonyl compounds. Attempts to prepare a pyridine bis(oxazoline) iron dinitrogen complex by sodium amalgam reduction of the corresponding dichloride precursor yielded a catalytically inactive S = 1 bis(chelate) iron complex. Dialkyl derivatives of the general formula (RPybox)Fe(CH2SiMe3)2 were prepared either by pyridine displacement from (py)2Fe(CH2SiMe3)2 or by direct dialkylation of the appropriate iron dichloride. Two examples of the S = 2 complexes were characterized by single-crystal X-ray diffraction. Each enantiopure Pybox iron dialkyl was evaluated in the catalytic hydrosilylation of various ketones. Efficient turnover was observed at 23 °C with 0.3% of the iron precatalyst using PhSiH3 as the stoichiometric reductant. Fo...
Direct conversion of α,β-unsaturated nitriles into cyanohydrins using Mn(dpm)3 catalyst, dioxygen and phenylsilane

Abstract Treatment of α,β-unsaturated nitriles with Mn(dpm) 3 (3 mol%), PhSiH 3 in isopropyl alcohol in the presence of oxygen resulted in reduction and α- and β-hydroxylation.
The Tree Formula for MHV Graviton Amplitudes

We present and prove a formula for the MHV scattering amplitude of n gravitons at tree level. Some of the more interesting features of t he formula, which set it apart as being significantly different from many more familiar formulas, include the absence of any vestigial reference to a cyclic ordering of the gravitons — making it in a sense a truly gravitational formula, rather than a recycled Yang-Mills result, and the fact that it simultaneously manifests both S n − 2 symmetry as well as large-z behavior that is $ \mathcal{O}\left( {{{1} \left/ {{{z^2}}} \right.}} \right) $ term-by-term, without relying on delicate cancellations. The formula is seemingly related to others by an enormous simplification provided by $ \mathcal{O}\left( {{n^n}} \right) $ iterated Schouten identities, but our proof relies on a complex analysis argument rather than such a brute force manipulation. We find that the formula has a very simple link representation in twistor space, where cancellations that are non-obvious in physical space become manifest.
Cage molecules for self-assembly

Abstract Self-assembled monolayers using functionalized cage molecules offer distinct advantages because of their symmetry, lack of conformational flexibility, and well-defined chemistries. While these systems have not yet been studied to the extent that linear alkanethiols on Au{1 1 1} have been, early explorations indicate great promise and important differences. For simple cage molecules that bind upright on the substrate, tilt domain boundaries found in linear chain systems are completely eliminated. Cage molecules can be designed to have a great range of intermolecular interactions, which thereby define the stabilities of the assemblies. Weakly interacting monolayers, such as those of 1-adamantanethiol on Au{1 1 1} are labile relative to exchange reactions from solution, vapor, or contact, and thus can be used as sacrificial placeholders and diffusion barriers in soft lithography. Such molecules can be further functionalized to serve as molecular resists for chemical patterning. Cage molecules can also be designed with directional interactions, as for carboranethiols, where molecules with identical lattices have dramatically different chemical and physical properties, and film stabilities. Multifunctional cage molecules enable further directed surface reactions, higher order supramolecular assembly, and ultimately, precise three-dimensional assembly off the surface.
Heating and Efficiency Comparison of a Fischer-Tropsch (FT) Fuel, JP-8+100, and Blends in a Three-Cup Combustor Sector

In order to realize alternative fueling for military and commercial use, industry guidelines be met. These aviation fueling requirements are outlined in MIL-DTL-83133F(2008) or ASTM D 7566-Annex standards and are classified as “drop-in” fuel replacements. This paper provides combustor performance data for synthetic-paraffinic-kerosene- (SPK-) type (Fisher-Tropsch (FT)) fuel and blends with JP8
VERSATILE 3 + 1 SYNTHESES OF ACENAPHTHOPORPHYRINS, A NEW FAMILY OF HIGHLY CONJUGATED TETRAPYRROLES

Abstract Acenaphthoporphyrins, a new group of porphyrins with strongly red shifted electronic absorption spectra, have been prepared by the acid catalysed condensation of a pyrrole-2,5-dicarboxaldehyde with acenaphthotripyrranes; similarly, c-annelated pyrroledialdehydes afforded the related opp-diacenaphthoporphyrins and a mixed porphyrin system with fused phenanthrene and acenaphthylene rings.
HYPERVELOCITY STARS. II. THE BOUND POPULATION

Hypervelocity stars (HVSs) are stars ejected completely out of the Milky Way by three-body interactions with the massive black hole in the Galactic center. We describe 643 new spectroscopic observations from our targeted survey for HVSs. We find a significant (3.5 � ) excess of B-type stars with large velocities +275 km s � 1 10 kpc that are most plausibly explained as a new class of HVSs: stars ejected from the Galactic center on bound orbits. If a Galactic center ejection origin is correct, the distribution of HVSs on the sky should be anisotropic for a survey complete to a fixed limiting apparent magnitude. The unbound HVSs in our survey have a marginally anisotropic distribution on the sky, consistent with the Galactic center ejection picture. Subject headingg Galaxy: center — Galaxy: halo — Galaxy: kinematics and dynamics — Galaxy: stellar content — stars: early-type
Synthesis of potent and selective dopamine D4 antagonists as candidate radioligands

A series of dopamine D(4) antagonists was synthesized and evaluated as potential candidates for development as positron emission tomography (PET) radioligands. All new compounds display high affinity and selectivity for the D(4) receptors and compounds 5b, 5d, and 5e were identified as candidates for radioligand development.
The Radiative Stress Tensor

We use the transfer equation in relativistic form to develop an expansion of the one-photon distribution for a medium with constant photon mean free path, . On carrying out appropriate integrations and manipulations, we convert this expansion into one for the frequency-integrated intensity. We regroup the terms of the intensity expansion according to both the power of and the angular structure of the various terms and then carry out angle integrations to obtain the expansions for the components of the stress energy tensor: the radiative energy density, the radiative flux, and the pressure tensor. In leading order, we recover Thomas' results for the viscosity tensor and his expression for the viscosity coefficient, which are correct for short mean free paths. As had been done earlier for the radiative heat equation, we keep at each order in the expansion a dominant portion, but this time one with a richer angular structure. Then, after some rearrangement of the various summations in the expressions for the moments, we replace the sum of the calculated higher order terms by a Pade approximant, or rational approximation, to provide an improved closure approximation for the radiative stress tensor. The resulting radiative viscosity tensor may be expressed either as a simple integral operator acting on the Thomas stress tensor or as the solution of an inhomogenous, linear partial differential equation. The expression obtained for the radiative viscosity tensor applies for media with long, as well as short, photon mean free paths. We also develop results applicable for relatively smooth flows by using the form of the Thomas stress tensor with generalized transport coefficients derived by the application of a suitable operator to the bare Thomas coefficients.
PHYSICS PROSPECTS AT BTEV

BTeV is a recently approved collider program at the Fermilab Tevatron dedicated to the study of CP violation, mixing and rare decays in beauty and charm hadrons. The detector is a two-arm forward spectrometer sited at the C-Zero interaction region. Data taking is expected to commence in 2006. The physics goals and spectrometer are described. Details are given of simulations which determine the physics reach of the experiment.
The Effect of Blazar Spectral Breaks on the Blazar Contribution to the Extragalactic Gamma-Ray Background

The spectral shapes of the contributions of different classes of unresolved gamma-ray emitters can provide insight into their relative contributions to the extragalactic gamma-ray background (EGB) and the natures of their spectra at GeV energies, We calculate the spectral shapes of the contributions to the EGB arising from BL Lacertae type objects (BL Lacs) and flat-spectrum radio quasars (FSRQs) assuming blazar spectra can be described as broken power laws, We fit the resulting total blazar spectral shape to the Fermi Large Area Telescope measurements of the EGB, finding that the best-fit shape reproduces well the shape of the Fermi EGB for various break scenarios. We conclude that a scenario in which the contribution of blazars is dominant cannot be excluded on spectral grounds alone, even if spectral breaks are shown to be common among Fermi blazars. We also find that while the observation of a featureless (within uncertainties) power-law EGB spectrum by Fermi does not necessarily imply a single class of contributing unresolved sources with featureless individual spectra, such an observation and the collective spectra of the separate contributing populations determine the ratios of their contributions. As such, a comparison with studies including blazar gamma-ray luminosity functions could have profound implications for the blazar contribution to the EGB, blazar evolution, and blazar gamma-ray spectra and emission.
SURGICAL TREATMENT OF LOW RECTOVAGINAL FISTULAS

Forty women with low rectovaginal fistulas were operated upon over a 9-year period. The etiology of the fistula in the majority was obstetric. Nine women had prior attempts to repair the fistula. All 40 women were managed with endorectal advancement flap with the addition of sphincteroplasty or perineal body reconstruction in 15 patients and rectocele repair in six patients. Postoperative complications included urinary difficulties (two patients) and wound complications (three patients). There were two recurrences. All women treated with sphincteroplasty or perineal body reconstruction were continent. Seven women complained of varying degrees of incontinence postoperatively; none had undergone sphincter or perineal body reconstruction. Endorectal advancement flap is a safe and effective operation for women with rectovaginal fistulas. Concomitant sphincteroplasty or perineal body reconstruction should be performed in women with historical, physical, or manometric evidence of incontinence.
Advances in Discrete-Time Dynamic Data Representation with Applications to Intelligent Transportation Systems

Efficient storage, processing, and communication of dynamic data are at the heart of intelligent transportation systems (ITS) applications. The speed of communication and processing as well as the storage space required by such data depend on the method used for its representation. ITS applications typically involve dynamic data that are discrete and require fast computation and communication speeds to support real-time operations. An efficient representation method is presented, which is called the bit-stream representation, for discrete-time dynamic data. Its positive impacts are presented by developing efficient representations for storage and communication of travel times in dynamic transportation networks. It is shown theoretically that this representation method typically leads to an L/2-fold gain in both storage space and communication speed compared with methods that represent discrete-time dynamic data using L-bits to store an integer. The proposed representation holds the potential to develop new faster algorithms that would directly operate on dynamic data represented as bit streams.
Measurements of radiative heating on sharp cones

Free flight measurement of radiative heat load on circular cone and comparison with predicted equilibrium and nonequilibrium radiation
[Ecological developmental biology: developmental biology meets the real world].

The production of phenotype is regulated by differential gene expression. However, the regulators of gene expression need not all reside within the embryo. Environmental factors, such as temperature, photoperiod, diet, population density, or the presence of predators, can produce specific phenotypes, presumably by altering gene-expression patterns. The field of ecological developmental biology seeks to look at development in the real world of predators, competitors, and changing seasons. Ecological concerns had played a major role in the formation of experimental embryology, and they are returning as the need for knowledge about the effects of environmental change on embryos and larvae becomes crucial. This essay reviews some of the areas of ecological developmental biology, concentrating on new studies of Amphibia and Homo.
The distribution of chlorpyrifos following a crack and crevice type application in the US EPA Indoor Air Quality Research House

Abstract A study was conducted in the US EPA Indoor Air Quality (IAQ) Research House to determine the spatial and temporal distribution of chlorpyrifos following a professional crack and crevice application in the kitchen. Following the application, measurements were made in the kitchen, den and master bedroom over 21 days. Airborne concentrations were collected using both polyurethane foam (PUF) and the OSHA versatile sampler composed of XAD and PUF media located in tandem. Measured airborne concentrations were similar for the two samplers and were higher in the three rooms following the application. The highest measured concentrations were reached during the initial 24-h following application; concentrations subsequently declined over the 21-day study period to levels slightly above background. Spatial and temporal distributions onto surfaces were measured using 10-cm2 rayon deposition coupons located on the floor. Sections were cut from existing carpet to determine the total extractable residues. Chlorpyrifos was measured from all matrixes in the kitchen, den and bedroom and the data shows the transport of airborne residues from the point of application to remote locations in the house. The findings are compared and discussed relative to another study conducted in which total release aerosols containing chlorpyrifos were activated in the IAQ research house and the resulting distributions evaluated. For both studies dose estimates were constructed for the exposure pathways using the Stochastic Human Exposure and Dose Estimation Model for pesticides. The United States Environmental Protection Agency has been mandated to examine children's exposure to environmental pollutants such as pesticides. This research specifically reduces uncertainties associated with estimating children's potential exposures to residentially applied pesticides and provides inputs to further evaluate and validate residential exposure models which might be used to reduce exposures and perform risk assessments.
Single crystal structure and Raman spectrum of Ba3Na2(CN2)4

Abstract The synthesis, single crystal structure determination, and Raman spectrum are reported for colorless transparent tribarium disodium tetracyanamide, Ba3Na2(CN2)4. The title compound crystallizes in the space group C2h5-P21/c (#14, a = 6.2872 ( 5 ) A , b = 10.0002 ( 8 ) A , c = 17.7303 ( 16 ) A , β = 110.454 ( 4 ) ° , V = 1044.48 ( 15 ) A 3 , Z = 4 , R / w R = 0.0266 / 0.0543 ). Each sodium atom is surrounded by six nitrogen atoms in octahedral geometry. Sodium centered nitrogen octahedra are linked through face-sharing along the [100] direction to form one-dimensional (1D) chains. These chains are connected to each other through the carbon atoms of cyanamide and make a three-dimensional (3D) network with 1D channels along the [100] direction. Barium atoms and additional cyanamide anions reside in the channels. Each barium atom is irregularly coordinated with nitrogen and carbon from the cyanamide anions. The Raman spectrum shows symmetric vibrations of [N C N]2− corresponding to νsym (1241.5 cm−1) and 2δ (1356.4 cm−1).
Product Safety, Buybacks and the Post-Sale Duty to Warn

A manufacturer learns a product's risks after it has been sold and distributed to consumers. When held strictly liable for product-related injuries, the manufacturer offers to repurchase the product when the risk exceeds a threshold. Consumers accept the offer when their private valuations of consumption are smaller than the buyback price. The manufacturer's private incentives to stage a buyback are insufficient, the buyback price offered is too low, and the continued product usage by consumers is excessive. The ability of the manufacturer to repurchase the product ex post reduces the incentive to design safer products ex ante. A negligence rule, the "post-sale duty to warn," implements the social welfare benchmark. The Author 2010. Published by Oxford University Press on behalf of Yale University. All rights reserved. For Permissions, please email: journals.permissions@oxfordjournals.org, Oxford University Press.
TIME VARIATIONS IN RISK PREMIA, VOLATILITY, AND REWARD‐TO‐VOLATILITY

In this paper I relate the risk premia in the stock and bond markets to the conditional volatility of returns and time-varying reward-to-volatility variables. I find that the relation between the expected returns on the stocks and bonds and the volatility of returns is time varying. I provide an approach for evaluating the relative importance of the time-varying volatility of returns and reward-to-volatility variables to explain the predictability of risk premia for stock and bond returns. I show that changing reward-to-volatility variables explain more predictable variation in the risk premia for stocks and bonds than changing volatility of returns.
Far-Infrared and Submillimeter Wave Attenuation by Clouds and Rain

Abstract Newly determined optical constants for water at far-infrared and submillimeter wavelengths, as revealed by a recent survey, are used to estimate water cloud and rain attenuation over the wavelength range between λ12 μm and λ2 cm. For this purpose new analytic drop-size distribution models simulating fog, nimbostratus cloud and rain, corresponding to rainfall rates of 10 and 50 mm h−1, are set up. The corresponding volume extinction and absorption coefficients as computed according to polydisperse Mie scattering theory at specific wavelengths are listed in tables and presented graphically in plots for purposes of interpolation. It is found that cloud extinction may exceed 50 nepers per kilometer in the λ≲100 μm region, whereas for wavelengths longer than λ200 μm, under near-saturated conditions, water vapor absorption should be the dominant attenuator. The greatest attenuation by heavy rain may be expected around λ5 mm with a value of about 5 nepers per kilometer. The results also suggest that in ...
Enantioselective organocatalytic indole alkylations. Design of a new and highly effective chiral amine for iminium catalysis.

The indole framework has become widely identified as a “privileged” structure with representation in over 3000 natural isolates and 40 medicinal agents of diverse therapeutic action. A new strategy for asymmetric access to this important pharmacaphore has been accomplished that involves the amine catalyzed alkylation of indoles with α,β-unsaturated aldehydes. Central to these studies has been the design of a new chiral amine catalyst that exhibits improved reactivity and selectivity for iminium catalysis. This new (2S,5S)-5-benzyl-2-tert-butyl-imidazolidinone catalyst has enabled the conjugate addition of a variety of indole systems to a diverse range of α,β-unsaturated aldehydes in high yield and with excellent levels of enantiocontrol (70−97% yield, 84−97% ee). A demonstration of the utility of this new organocatalytic alkylation for the rapid construction of biomedically relevant molecules is presented in the enantioselective synthesis of an indolobutyric acid COX-2 inhibitor.
Environmental sensing in composite oxide semiconductor films

Multicomponent semiconductor oxides mainly composed of elements like indium, zinc, tin or gallium are very promising new class of materials for application in transparent electronics, multifunctional sensors and other electronic applications. The major characteristic of these materials is high mobility, and the electrical behavior is a consequence of a conduction band primarily derived from spherically symmetric heavy-metal cationns orbital with (n-1)d 10 ns 0 (n ≥4) electronic configuration. The carrier transport becomes insensitive to the degree of disorder of the film, and makes this class of quasi-polycrystalline and amorphous semiconductors attractive for numerous applications.We report here on the environmental sensing, such as ultra-violet-radiation and various gases of pulsed-laser deposited composite semiconductor films. These films demonstrate outstanding sensing capability from measuring the surface resistivity taking into account the absorption of sensing species. Our results show new possibilities for the low-cost high performance environmental sensors for numerous potential applications. The details of the results will be presented.
Microwave-induced organic reaction enhancement (more) chemistry: Techniques for rapid, safe and inexpensive synthesis

Synthetic organic reactions have been conducted under microwave irradiation in open vessels in unaltered domestic microwave ovens. Reaction times vary from a few seconds for sub-milligram reactions to about 15 minutes for reactions carried out on a scale of hundreds of grams. Promising results have been obtained for several condensations, as well as the Bischler-Napieralski reaction, the Wolff-Kishner reduction, free radical dehalogenation reactions, and other standard synthetic operations. Rapid catalytic transfer hydrogenation using ammonium formate as the source of hydrogen has been conducted at about 100-130 °C under microwave irradiation.
House prices and city revenues

Abstract Very little is known about what impact recent large upward and downward swings in single-family home values have had on local government budgets. Using a unique 15-year panel of Florida cities that includes both detailed revenue and house price data, we investigate the pathways whereby a change in house price may affect city revenue per capita and test for symmetric effects during housing booms and busts. For the median-sized city, we find that while increases in house price raise revenues, decreases in price have no effect on revenues. In addition, the former impact is small in magnitude. While the strongest pathway is through assessed values, our results illustrate that a change in house price can also affect other sources of revenue besides ad valorem taxes. The overall conclusion is that movements in Florida housing markets are only weakly related to a city's property taxes and total revenues per capita, which fails to support the argument portrayed in the popular press that house price changes strongly impact local budgets.
A recursive approach to detect multivariable conditional variance components and conditional random effects

A complex trait like crop yield is determined by its component traits. Multivariable conditional analysis in a general mixed linear model is helpful in dissecting the gene expression for the complex trait due to different effects, such as environment, genotype, and genotype x environment interaction. A recursive approach is presented for constructing a new random vector that can be equivalently used to analyze multivariable conditional variance components and conditional effects. End-of-season plant mapping data, including lint yield and three yield components for nine cultivars of upland cotton (Gossypium hirsutum L.) were used to detect the conditional variance components and conditional effects using this new approach, which can help identify genotypes to be used in selection studies.
A Case of Premature Termination in a Treatment for Generalized Anxiety Disorder

In this paper we present a case of failure in an integrative treatment for generalized anxiety disorder (GAD) combining cognitive-behavioral therapy, an empirically supported treatment for GAD, and interpersonal-emotional processing therapy. The client of focus dropped out of treatment after the eighth session. Based on our analysis of this case, we discuss the participant, technical and relationship factors that were likely implicated in this case of premature termination in both of the cognitive-behavioral and interpersonal-emotional processing segments that comprised the treatment. Implications for practice, training and future research are also discussed.
Monitoring the Health and Safety of the ACIS Instrument On-Board the Chandra X-ray Observatory

The Chandra X-ray Observatory (CXO), NASA's latest "Great Observatory", was launched on July 23, 1999 and reached its final orbit on August 7, 1999. The CXO is in a highly elliptical orbit, approximately 140,000 km × 10,000 km, and has a period of approximately 63.5 hours (≈2.65 days). Communication with the CXO nominally consists of 1-hour contacts spaced 8-hours apart. Thus, once a communication link has been established, it is very important that the health and safety status of the scientific instruments as well as the Observatory itself be determined as quickly as possible. In this paper, we focus exclusively on the automated health and safety monitoring scripts developed for the Advanced CCD Imaging Spectrometer (ACIS) during those 1-hour contacts. ACIS is one of the two focal plane instruments on-board the CXO. We present an overview of the real-time ACIS Engineering Data Web Page and the alert schemes developed for monitoring the instrument status during each communication contact. A suite of HTML and PERL scripts monitors the instrument hardware house-keeping electronics (i.e., voltages and currents) and temperatures during each contact. If a particular instrument component is performing either above or below pre- established operating parameters, a sequence of email and alert pages are spawned to the Science Operations Team of the Chandra X-ray Observatory Center so that the anomaly can be quickly investigated and corrective actions taken if necessary. We also briefly discuss the tools used to monitor the real-time science telemetry reported by the ACIS flight software. The authors acknowledge support for this research from NASA contract NAS8-39073.
3-manifolds which are spacelike slices of flat spacetimes

We continue work initiated in a 1990 preprint of Mess giving a geometric parametrization of the moduli space of classical solutions to Einstein's equations in (2 + 1) dimensions with cosmological constant Λ = 0 or -1 (the case of Λ = + 1 has been worked out in the interim by the present author). In this paper we make a first step toward the (3 + 1)-dimensional case by determining exactly which closed 3-manifolds M3 arise as spacelike slices of flat spacetimes, and by finding all possible holonomy homomorphisms π1(M3)→ISO(3,1).
A Time-Linearized Navier–Stokes Analysis of Stall Flutter

A computational method for predicting unsteady viscous flow through two-dimensional cascades accurately and efficiently is presented. The method is intended to predict the onset of the aeroelastic phenomenon of stall flutter. In stall flutter, viscous effects significantly impact the aeroelastic stability of a cascade. In the present effort, the unsteady flow is modeled using a time-linearized Navier-Stokes analysis. Thus, the unsteady flow field is decomposed into a nonlinear spatially varying mean flow plus a small-perturbation harmonically varying unsteady flow. The resulting equations that govern the perturbation flow are linear, variable coefficient partial differential equations. These equations are discretized on a deforming, multiblock, computational mesh and solved using a finite-volume Lax-Wendroff integration scheme. Numerical modeling issues relevant to the development of the unsteady aerodynamic analysis, including turbulence modeling, are discussed. Results from the present method are compared to experimental stall flutter data, and to a nonlinear time-domain Navier-Stokes analysis. The results presented demonstrate the ability of the present time-linearized analysis to model accurately the unsteady aerodynamics associated with turbomachinery stall flutter.
Automated estimation of the parameters of Gibbs priors to be used in binary tomography

Image modeling using Gibbs priors was previously shown, based on experiments, to be effective in image reconstruction problems. This motivated us to evaluate three methods for estimating the priors. Two of them accurately recover the parameters of the priors; however, all of them are useful for binary tomography. This is demonstrated by two sets of experiments: in one the images are from a Gibbs distribution and in the other they are typical cardiac phantom images.
TELECOMMUTING AND TRAVEL: STATE OF THE PRACTICE, STATE OF THE ART

This paper provides an overview of the status of telecommuting in the United States, especially as it relates to changes in travel behavior. Regarding the state of the practice, the paper discusses some refinements to the definition of telecommuting that have developed through increased operational experience. It reports several policy statements involving telecommuting, and explores the appeal of telecommuting as a public policy instrument. It highlights some trends in the implementation of home-based and work center-based telecommuting, and suggests that visible public-sector involvement has been crucial to the increased activity in this area.
Undiagnosed hepatitis C on the general medicine and trauma services of two urban hospitals

Summary The inpatient medical service may be an important location to identify undiagnosed hepatitis C virus (HCV) infection. We conducted a cross-sectional HCV prevalence study in consecutive patients aged 18–65 admitted in a three-month period to two urban hospitals' general internal medicine and trauma services. Patient sera were anonymously screened for anti-HCV antibody with an enzyme-linked immunoassay and, when anti-HCV positive (+), for HIV. Health system records were examined for prior HCV testing or diagnosis or an HIV diagnosis then linked anonymously to test results. Multivariate logistic regression was used to examine associations of patient and health care factors with unknown HCV+ status. Of 786 unique patients tested (60.3% of all admitted patients), 62 (7.9%) were HCV+ without a prior HCV+ test or diagnosis while 61 patients (7.8%) tested HCV+ but had prior HCV+ test or diagnosis. Of 62 patients with unknown HCV+, 6 (9.7%) were HIV+ but only 3 had a prior HIV diagnosis; of 61 patients with known HCV+, all 9 (14.8%) HIV+ had been diagnosed. Among the 640 patients with prior unknown HCV status, an HCV+ test was strongly associated with age: 50–65 (adjusted odds ratio [AOR] 5.44, CI 2.20–13.48) and age 36–49 (AOR 4.65, CI 1.91–11.32) versus. 18–35. In this anonymous study, we could not obtain HCV risk factor data but the positive and negative predictive values of HCV testing all inpatients with an unknown HCV status were 99.3% and 99.0%, respectively. In similar urban general medicine and trauma services, broader efforts to test for HCV in inpatients aged 36–65 may be warranted.
Information Considerations for Logistics Network Planning

Deciding where to locate stocking points and plants within a logistics network, which ports or vendor locations to use, and how the product should flow through this network are common strategic planning problems for many businesses. Management scientists have laboured for many years to create models that can assist businesses with this type of problem. Numerous such models are described in the management literature. Much attention is given to improving their scope, robustness, speed of solution, and mathematical sophistication. Very little attention is given to the information that drives these models and so strongly affects their accuracy and utility, yet management should have more concern about the input data to these models than about the way in which a particular model solves the problem.
Cloning and characterization of a novel serine/threonine protein phosphatase type 5 from Trypanosoma brucei.

Abstract Reversible protein phosphorylation is essential for the regulation of numerous cellular functions and differentiation. The haemo-flagellated parasitic protozoan Trypanosoma brucei, the causative agent for African trypanosomiasis undergoes various stages of cellular differentiation during its digenetic life cycle. A complete cDNA of a unique serine/threonine phosphatase type five (TbPP5) was cloned and characterized from T. brucei. TbPP5 contains an open reading frame of 1416 bp that encodes a protein of about 53 kDa and exists as a single copy gene in the T. brucei genome. The deduced amino acid sequence showed 45–48% overall identity and 60–65% similarity with protein phosphatase 5′s (PP5) from different species. Analysis of the primary sequence revealed that TbPP5 contains three TPR motifs at the N-terminal region (amino acid residues 7–107) while the phosphatase catalytic domain occurs in the C-terminal region (amino acid residues 210–410). A TbPP5 cDNA hybridized with a transcript of 2.5 kb which is present at similar levels in the procyclic and the bloodstream forms. However, the level of expression of the TbPP5 protein (52 kDa) detected by an antibody developed against a recombinant protein produced in E. coli was about 2-fold higher in the procyclic than the bloodstream form. The TbPP5 transcript level gradually decreased in cells grown in the logarithmic phase to the stationary phase in culture. Moreover, 18 h serum starvation of the procyclic forms decreased the level of the specific transcript about 3-fold suggesting that this protein may play a role during the active growth phase of the organism. The recombinant protein showed phosphatase activity which was stimulated about 2.6-fold by arachidonic acid with half-maximal activity at 75 μM. Indirect immuno-fluoresence of permeabilized cells revealed that the protein is localized in the cytosol and the nucleus This is the first report for the identification of a type 5 serine/threonine protein phosphatase in an ancient eukaryote such as T. brucei.
The Dynamics of Electron Self-Exchange between Nanoparticles

The rate of electron self-exchange reactions between discretely charged metal-like cores of nanoparticles has been measured in multilayer films of nanoparticles by an electrochemical method. The nanoparticles are Au monolayer-protected clusters with mixed monolayers of hexanethiolate and mercaptoundecanoic acid ligands, linked to each other and to the Au electrode surface with carboxylate−metal ion−carboxylate bridges. Cyclic voltammetry of the nanoparticle films exhibits a series of well-defined peaks for the sequential, single-electron, double-layer charging of the 1.6-nm-diameter Au cores. The electron self-exchange is measured as a diffusion-like electron-hopping process, much as in previous studies of redox polymer films on electrodes. The average electron diffusion coefficient is DE = 10(±5) × 10-8 cm2/s, with no discernible dependence on the state of charge of the nanoparticles or on whether the reaction increases or decreases the core charge. This diffusion constant corresponds to an average first...
Ordering by weighted number of wins gives a good ranking for weighted tournaments

We consider the following simple algorithm for feedback arc set problem in weighted tournaments --- order the vertices by their weighted indegrees. We show that this algorithm has an approximation guarantee of 5 if the weights satisfy probability constraints (for any pair of vertices u and v, wuv + wvu = 1). Special cases of feedback arc set problem in such weighted tournaments include feedback arc set problem in unweighted tournaments and rank aggregation. Finally, for any constant e > 0, we exhibit an infinite family of (unweighted) tournaments for which the above algorithm (irrespective of how ties are broken) has an approximation ratio of 5 - e.
Absence of a Slater Transition in the Two-Dimensional Hubbard Model

We present well-controlled results on the metal-to-insulator transition (MIT) within the paramagnetic solution of the dynamical cluster approximation in the two-dimensional Hubbard model at half filling. In the strong coupling regime, a local picture describes the properties of the model; there is a large charge gap Delta approximately U. In the weak-coupling regime, we find that a symbiosis of short-range antiferromagnetic correlations and moment formation cause a gap to open at finite temperature as in one dimension. Hence, this excludes the mechanism of the MIT proposed by Slater long ago.
Man-Machine Console Facilities for Computer-Aided Design:

The backbone of the man-machine communication link in Computer-Aided Design is a console whose principal components are the display scope and the light pen. The display scope is an ordinary cathode ray tube which is controlled by the computer by means of program instructions. It allows the computer to output to the man rapidly in easily interpreted graphical form. The data displayed can be textual, pictorial, or a combination of the two. The light pen is a photosensitive device which responds to the light generated by an intensified point on the scope face and which amplifies, shapes and transmits this response back to the computer where it can be tested by the program and used as a branch condition. The display scope and light pen form, so to speak, the paper and pencil of the designer, but they possess some extremely useful additional properties which open a whole new expressive medium. The following papers describe some of the fascinating and invaluable facilities which are provided by this basically simple hardware. In this paper we present some basic information about the hardware itself and describe some of the sophistications appropriate to the Computer-Aided Design problem.
Chiral symmetry on a lattice with hopping interactions

Abstract The species doubling problem of the lattice fermion is resolved by introducing hopping interactions that mix left- and right-handed fermions around the momentum boundary. Approximate chiral symmetry is realized on the lattice. The deviation of the fermion propagator from the continuum one is small.
6-Endo Heck Cyclization of 3-(2-Iodophenoxy)methylbenzofurans: A Useful Approach to Pterocarpenes

Abstract Mitsunobu coupling of 3-hydroxymethylbenzofurans with o-iodophenols affords 3-(2-iodophenoxy)methylbenzofurans which under go a useful 6-endo Heck cyclization under Jeffery conditions to afford pterocarpene-type heterocycles. The unsubstituted parent pterocarpene thus prepared was readily converted to coumestan via subsequent PCC oxidation. Supplemental materials are available for this article. Go to the publisher's online edition of Synthetic Communications® to view the free supplemental file.
Leptoquarks at Future Lepton Colliders

In this talk I summarize the capability of future lepton colliders to discover leptoquarks and to determine their electroweak quantum numbers. This analysis is an updated discussion based on the results presented in the Snowmass 1996 New Phenomena Working Group report as well as some more recent work that has appeared in the literature as a result of the HERA high-Q2 excess.
Gamma-ray probe of cosmic ray pressure in galaxy clusters and cosmological implications

Cosmic rays produced in cluster accretion and merger shocks provide pressure to the intracluster medium (ICM) and affect the mass estimates of galaxy clusters. Although direct evidence for cosmic ray ions in the ICM is still lacking, they produce γ -ray emission through the decay of neutral pions produced in their collisions with ICM nucleons. We investigate the capability of the Gamma-ray Large Area Space Telescope (GLAST) and imaging atmospheric Cerenkov telescopes (IACTs) for constraining the cosmic ray pressure contribution to the ICM. We show that GLAST can be used to place stringent upper limits, a few per cent for individual nearby rich clusters, on the ratio of pressures of the cosmic rays and thermal gas. We further show that it is possible to place tight (≤ 10 per cent) constraints for distant (z ≤ 0.25) clusters in the case of hard spectrum, by stacking signals from samples of known clusters. The GLAST limits could be made more precise with the constraint on the cosmic ray spectrum potentially provided by IACTs. Future γ-ray observations of clusters can constrain the evolution of cosmic ray energy density, which would have important implications for cosmological tests with upcoming X-ray and Sunyaev–Zel’dovich effect cluster surveys.
Unified Theory for Aircraft Handling Qualities and Adverse Aircraft-Pilot Coupling

A unified theory for aircraft handling qualities and adverse aircraft-pilot coupling or pilot-induced oscillations is introduced. The theory is based on a structural model of the human pilot. A methodology is presented for the prediction of (1) handling qualities levels; (2) pilot-induced oscillation rating levels; and (3) a frequency range in which pilot-induced oscillations are likely to occur. Although the dynamics of the force-feel system of the cockpit inceptor is included, the methodology will not account for effects attributable to control sensitivity and is limited to single-axis tasks and, at present, to linear vehicle models. The theory is derived from the feedback topology of the structural model and an examination of flight test results for 32 aircraft configurations simulated by the U.S. Air Force/CALSPAN NT-33A and Total In-Flight Simulator variable stability aircraft. An extension to nonlinear vehicle dynamics such as that encountered with actuator saturation is discussed.
Near-wall k-epsilon turbulence modeling

The flow fields from a turbulent channel simulation are used to compute the budgets for the turbulent kinetic energy (k) and its dissipation rate (epsilon). Data from boundary layer simulations are used to analyze the dependence of the eddy-viscosity damping-function on the Reynolds number and the distance from the wall. The computed budgets are used to test existing near-wall turbulence models of the k-epsilon type. It was found that the turbulent transport models should be modified in the vicinity of the wall. It was also found that existing models for the different terms in the epsilon-budget are adequate in the region from the wall, but need modification near the wall. The channel flow is computed using a k-epsilon model with an eddy-viscosity damping function from the data and no damping functions in the epsilon-equation. These computations show that the k-profile can be adequately predicted, but to correctly predict the epsilon-profile, damping functions in the epsilon-equation are needed.
Application of a Local Grid Refinement Protocol in Highly Faulted Reservoir Architectures

A three-dimensional, three-phase black oil simulator is used to model the flow regimes and flow geometries around sealing/non-sealing flow barriers in hydrocarbon reservoirs with homogeneous property distribution. A localgrid refinement techaique is utilized in these numerical simulation models to accurately capture the flow regimes and flow geometries. Previous work examined a local grid refinement algorithm that was applied to study flow around impermeable barriers, water coning problems, and waterflood front-tracking inhorizontal wells. In this paper, we extend the application of the algorithm to account for inclined faults. A system of faults in a large reservoir is considered in all of the cases studied. Sections of the reservoir are solved individually in the presence of geological discontinuities. The results from the static local grid refinement. technique indicate a much higher level of accuracy over the results generated using a coarse grid approximation around faulted zones of the reservoir. This level of accuracy is characterized by comparing the results generated by a completely fine grid and/or by a conventional refinement protocol. The proposed model is capable of providing a better representation of faulted reservoir architectures using significantly less CPU time. The proposed model can also be used in pressure transient analysis of wells located near non-sealing fault structures.
Mechanical energy transfer and dissipation in fibrous beta-sheet-rich proteins.

Mechanical properties of structural protein materials are crucial for our understanding of biological processes and disease states. Through utilization of molecular simulation based on stress wave tracking, we investigate mechanical energy transfer processes in fibrous beta-sheet-rich proteins that consist of highly ordered hydrogen bond (H-bond) networks. By investigating four model proteins including two morphologies of amyloids, beta solenoids, and silk beta-sheet nanocrystals, we find that all beta-sheet-rich protein fibrils provide outstanding elastic moduli, where the silk nanocrystal reaches the highest value of $\ensuremath{\approx}40\text{ }\text{GPa}$. However, their capacities to dissipate mechanical energy differ significantly and are controlled strongly by the underlying molecular structure of H-bond network. Notably, silk beta-sheet nanocrystals feature a ten times higher energy damping coefficient than others, owing to flexible intrastrand motions in the transverse directions. The results demonstrate a unique feature of silk nanocrystals, their capacity to simultaneously provide extreme stiffness and energy dissipation capacity. Our results could help one to explain the remarkable properties of silks from an atomistic and molecular perspective, in particular its great toughness and energy dissipation capacity, and may enable the design of multifunctional nanomaterials with outstanding stiffness, strength, and impact resistance.
Hydroboration of alkenylcarboranes: A regiochemical investigation

Abstract A series of ortho -carboranyl alkenes was hydroborated with representative boron hydride reagents. The inductive effect (−I) of the carborane nucleus significantll affected the regiochemistry of the reaction, increasing the ratio of 3 to 2 .
Heterobinuclear and heterotrinuclear transition-metal μ-allenyl complexes

Binuclear and trinuclear transition-metal μ-allenyl complexes—especially mixedmetal complexes—are reviewed. In recent years, a number of such compounds have been prepared by use of several synthetic methods. The most general of these methods, viz. reactions of metal propargyls and of the lower nuclearity metal allenyls with low-valent metal complexes such as metal carbonyls and platinum(0) compounds, are considered in some detail. The structures of the binuclear metal μ-η1,η2- and μ-η3,η2-allenyl complexes and of the trinuclear metal μ3-η1,η2,η2-allenyl complexes—both triangular and open—are presented and compared. Trends in the1H and13C NMR spectroscopic properties of these compounds are examined. Some aspects of reaction chemistry of the heteronuclear platinum-ruthenium μ-η1,η2-allenyl complexes are presented.