cssi/SciSciGPT-SciSciNet huggingface dataset:
Modelling of the microstructure and transport properties of concrete

Abstract Theoretical understanding of how the properties and performance of cement-based materials relate to microstructure is complicated by the large range of relevant size scales. Processes occurring in the nanometre-sized gel pores ultimately affect the performance of these materials at the structural level of metres and larger. One approach to alleviating this complication is the development of a suite of models, consisting of individual digital-image-based structural models for the calcium silicate hydrate gel at the nanometre level, the hydrated cement paste at the micrometre level and a mortar or concrete at the millimetre to metre level. Computations performed at one level provide input properties to be used in simulations of performance at the next higher level. This methodology is demonstrated for the property of ionic diffusivity in saturated concrete. In addition, the ideas of percolation theory are shown to unify microstructure and many physical phenomena at various length scales in concrete.
L 1 Optimization under Linear Inequality Constraints

optimization under linear inequality constraints based upon iteratively reweighted iterative projection (or IRIP). IRIP is compared to a linear programming (LP) strategy for L1 minimization (Spath 1987, Chapter 5.3) using the ultrametric condition as an exemlar class of constraints to be fitted. Coded for general constraints, the LP approach proves to be faster. Both methods, however, suffer from a serious limitation in being unable to process reasonably-sized data sets because of storage requirements for the constraints. When the simplicity of vector projections is used to allow IRIP to be coded for specific (in this case, ultrametric) constraints, we obtain a fast and efficient algorithm capable of handling large data sets. It is also possible to extend IRIP to operate as a heuristic search strategy that simultaneously identifies both a reasonable set of constraints to impose and the optimally-estimated parameters satisfying these constraints. A few noteworthy characteristics of L1 optimal ultrametrics are discussed, including other strategies for reformulating the ultrametric optimization problem.
Surfactant counter-ion induced processability of polyaniline: Photoinduced absorption studies

Abstract We present near steady state photo-induced absorption spectra of two forms of polyaniline (PANI) processed from solution as PANI-(S−) where S− denotes the surfactant counter-ion (CSA, DBSA, etc.). In the case of emeraldine base, two well-resolved photo-induced absorption bands are observed with maxima at 0.9 eV and 1.47 eV, accompanied by a bleaching of the 2 eV absorption edge. The different relaxation of the two bands indicates that they arise from two independent photo-induced nonlinear excitations. Temperature effects on the photoexcited states are observed both in the emeraldine base and the pernigraniline forms. The results are discussed in terms of intra- and interchain excitations. The possibility of deep traps on defect sites in pernigraniline is suggested.
Information quality and the valuation of new issues

Abstract The prevailing belief in the marketplace holds that the choices of auditor and investment banker affect the price of an initial public offering. This belief reflects the idea that the auditor and investment banker quality provides information about the firm's true value. This paper presents a model giving this belief theoretical support. Under plausible conditions, it is shown that an entrepreneur with favorable information about his firm's value chooses a higher-quality auditor and investment banker than an entrepreneur with less favorable information. As a result, firm value is an increasing function of auditor and investment banker quality.
The SRA domain of UHRF1 flips 5-methylcytosine out of the DNA helix

Maintenance methylation of hemimethylated CpG dinucleotides at DNA replication forks is the key to faithful mitotic inheritance of genomic methylation patterns. UHRF1 (ubiquitin-like, containing PHD and RING finger domains 1) is required for maintenance methylation by interacting with DNA nucleotide methyltransferase 1 (DNMT1), the maintenance methyltransferase, and with hemimethylated CpG, the substrate for DNMT1 (refs 1 and 2). Here we present the crystal structure of the SET and RING-associated (SRA) domain of mouse UHRF1 in complex with DNA containing a hemimethylated CpG site. The DNA is contacted in both the major and minor grooves by two loops that penetrate into the middle of the DNA helix. The 5-methylcytosine has flipped completely out of the DNA helix and is positioned in a binding pocket with planar stacking contacts, Watson-Crick polar hydrogen bonds and van der Waals interactions specific for 5-methylcytosine. Hence, UHRF1 contains a previously unknown DNA-binding module and is the first example of a non-enzymatic, sequence-specific DNA-binding protein domain to use the base flipping mechanism to interact with DNA.
Competitive subordination of a Piedmont old field successional dominant by an introduced species

On examine l'importance de la competition interspecifique dans le remplacement de Erigeron canadensis par Heterotheca latifolia
Minimum mean squared error (MSE) adjustment and the optimal Tykhonov–Phillips regularization parameter via reproducing best invariant quadratic uniformly unbiased estimates (repro-BIQUUE)

In a linear Gauss–Markov model, the parameter estimates from BLUUE (Best Linear Uniformly Unbiased Estimate) are not robust against possible outliers in the observations. Moreover, by giving up the unbiasedness constraint, the mean squared error (MSE) risk may be further reduced, in particular when the problem is ill-posed. In this paper, the α-weighted S-homBLE (Best homogeneously Linear Estimate) is derived via formulas originally used for variance component estimation on the basis of the repro-BIQUUE (reproducing Best Invariant Quadratic Uniformly Unbiased Estimate) principle in a model with stochastic prior information. In the present model, however, such prior information is not included, which allows the comparison of the stochastic approach (α-weighted S-homBLE) with the well-established algebraic approach of Tykhonov–Phillips regularization, also known as R-HAPS (Hybrid APproximation Solution), whenever the inverse of the “substitute matrix” S exists and is chosen as the R matrix that defines the relative impact of the regularizing term on the final result.
PHASES IN THE REPRESENTATION OF INTRAOBJECT SPATIALRELATIONS OF THE FACE AS PRECURSORS TO LITERACY: A TESTABLE HYPOTHESIS ENGENDERED BY NEOLITHIC ART

An hypothesis is discussed on the emergence of intrapattern spatial relational representation, one prerequisite for ultimate attainment of literacy skills. The hypothesis is testable, e.g., by evaluating potential phases in preschoolers' drawings of the face pattern or of analogous subtle spatial relations within a pattern. The hypothesis was engendered by an analysis of various face patterns engraved on an ancient stone with a “neolithic” face configuration from the Western Highlands of New Guinea. One heuristic value of the present study lies in its potential use for specific refinement of remedial assistance in the attainment of subtle intrapattern representation of spatial relations either in preschoolers or in developmental as well as in acquired dyslexia.
Occipital arteriovenous fistulae

Occipital arteriovenous fistulae may be congenital or traumatic. The distinguishing characteristics of each and diagnosis by dynamic computed tomographic (CT) scanning, obviating the need for angiography, is outlined and illustrated by a case report. The indications for surgery and operative approach are discussed.
Sexually transmitted disease in adolescents.

Abstract This case—sexually transmitted diseases in adolescents—is one of a series of teaching cases in the Case-Based Series in Population-Oriented Prevention (C-POP). It has been developed for use in medical school and residency prevention curricula. The complete set of cases is presented in this supplement to the American Journal of Preventive Medicine. Sexually transmitted diseases (STDs) are common among adolescents. This case focuses on the population-based prevention of STDs. The case begins with clinical, diagnostic, and laboratory management of an adolescent female diagnosed with gonorrhea. Students then examine how the diagnosis of an STD can be used as an opportunity to provide preventive care and counseling on safer sexual behaviors. Questions addressing HIV testing and counseling are included in this section. Students proceed to explore how the diagnosis and reporting of an STD calls for interaction, such as partner notification, between clinical providers and public health departments. Finally, students are provided with actual information from local focus groups on attitudes and behaviors of high-risk adolescents. At the conclusion of the case, they are asked to interpret the data and formulate strategies to decrease gonorrhea rates in the community.
Single Pulse Shock Tube Study of the Reaction Between Nitrogen Dioxide (NO2) and Carbon Monoxide (CO)

Abstract The reaction between NO2 and CO has been studied in a single pulse shock tube in the temperature range 950-1500 °K and at a total concentration of approximately 2.5× 10−5 moles/cc. Both the measured ratios of ([CO2]/[CO])1 and ([NO]/[NO2])1 have been used in separate series of experiments to examine the reaction The Arrhenius frequency factor and activation energy for ka were found to be 1013.51±0.25 cc/mole-sec and 32000± 1300 cal/mole, respectively. This result for k 12 is compared to literature values and the favorable comparison is taken as an indication that the modified single pulse shock tube analysis employed in this study leads to more reliable chemical kinetic data. The analysis methods include a special test mixture filling technique and a relative concentration at time solution for determining the final species concentration. These techniques reduce variation in the shocked gas reaction time and avoid concentration measurement errors associated with volume expansion sampling in a shoc...
DYNAMICAL SUPPRESSION OF DECOHERENCE IN TWO-STATE QUANTUM SYSTEMS

The dynamics of a decohering two-level system driven by a suitable control Hamiltonian is studied. The control procedure is implemented as a sequence of radio-frequency pulses that repetitively flip the state of the system, a technique that can be termed quantum ``bang-bang'' control after its classical analog. Decoherence introduced by the system's interaction with a quantum environment is shown to be washed out completely in the limit of continuous flipping and greatly suppressed provided the interval between the pulses is made comparable to the correlation time of the environment. The model suggests a strategy to fight against decoherence that complements existing quantum error-correction techniques.
Microparts processing using laser cutting and ultra-short-pulse laser peen forming

Abstract A laser peen forming is a sheet metal forming method using laser induced shock waves. The laser peen forming with an ultra-short-pulse laser is a kind of non-thermal and die-less forming process, and is favorable for microforming. The authors applied the laser peen forming to the bending of pure titanium thin sheet with a picosecond laser and a femtosecond laser. The changes of bending properties with atmosphere and pulse duration were investigated. The femtosecond laser irradiation in air showed the best bending efficiency. The femtosecond laser is applicable to laser cutting, also. Some thin sheets were cut into complicated shapes and bent by laser peen forming with femtosecond laser. The combined process allowed the production of various complicated small parts.
A design for testing clinical strategies: biased adaptive within-subject randomization

We propose a method for assigning treatment in clinical trials, called the ‘biased coin adaptive within-subject’ (BCAWS) design: during the course of follow-up, the subject's response to a treatment is used to influence the future treatment, through a ‘biased coin’ algorithm. This design results in treatment patterns that are closer to actual clinical practice and may be more acceptable to patients with chronic disease than the usual fixed trial regimens, which often suffer from drop-out and non-adherence. In this work, we show how to use the BCAWS design to compare treatment strategies, and we provide a simple example to illustrate the method.
BONE MARROW AND SPLEEN CELL HOMOTRANSPLANTATION IN DOGS FOLLOWING COMBINATION CHEMOTHERAPY AND TOTAL BODY IRRADIATION.

Summary o 1. Bone marrow and/or spleen cell transplants were performed in 71 dogs receiving TBR either alone or in combination with immunosuppressive drug therapy. Five animals survived by virtue of either successful autologous bone marrow or spleen cell transplants. 2. Two animals, who were irradiated in the lethal dose range (540 and 600 r) and whose marrow homograft failed to take, survived by regeneration of their own marrow. The importance of intensive supportive care, including frequent fresh whole blood transfusions, is described. 3. Temporary homologous bone marrow transplants were obtained in one animal following 1200 r alone; in one animal following 6-MP and 700 r; and in three animals following 6-MP and 900 r total body radiation. No permanent marrow takes were obtained and each of these animals died of grafted marrow-rejection. 4. Differences in the radiosensitivity of cells responsible for homograft immunity and ease of transplantation of bone marrow in the rodent, as compared to the dog, are discussed. Because the dog rejects homografted tissues following lethal (600 to 1000 r) doses of total body radiation, it is felt that transfusion of fresh blood containing viable leukocytes has no harmful effects, and evidence is presented that fresh whole blood, under these circumstances, is beneficial.
Theoretical modeling and numerical simulation of the corrosion and precipitation in non-isothermal liquid lead alloy pipe/loop systems

A theoretical kinetic model based on the boundary layer theory was developed to investigate the corrosion/precipitation in non-isothermal lead alloy pipe/loop systems. The analytical expressions of the local corrosion/precipitation rate and the bulk concentration of the corrosion products were obtained by considering a turbulent core region and a laminar sub-layer. Numerical solutions were also obtained together with considering the effect of eddy mass diffusivity in lead alloy systems.
The effects of 5-minute ischemia in Mongolian gerbils: I. Blood-brain barrier, cerebral blood flow, and local cerebral glucose utilization changes.

Changes in morphology, behavior of the blood-brain barrier (BBB), regional cerebral blood flow (rCBF), and local cerebral glucose utilization (LCGU) were assessed and correlated in Mongolian gerbils following 5 min cerebral ischemia, produced by bilateral clamping of the common carotid arteries. The morphological changes were confined to the hippocampus and revealed a conspicuously delayed destruction of the CA1 neurons, occurring after 3 days. Following release of carotid occlusions, there were two separate openings of the BBB. One, occurring shortly after recirculation, was associated with focal hyperemia in the cerebral cortex, hippocampus and basal ganglia; the second opening was observed after several days and was associated with severe neuronal destruction in the CA1 sector. Correlation of quantitative and qualitative rCBF assays with14C-deoxyglucose autoradiographic observations indicated an uncoupling between blood flow and glucose metabolism, observed in the hippocampus at 10 min after recirculation. The described changes provide a further insight into the post-ischemic events which determine the outcome of ischemic injury.
The asymptotic form of the Titchmarsh-Weyl m-function associated with a Dirac system

On considere le systeme d'equation de Dirac Jy'={λI+(q 1 (x)p(x)/pxq 2 (x))} y, 0≤x<b≤∞, ou J:=(0 −1/1 0), λ complexe. On etudie la forme asymptotique de la fonction m(λ) de Titchmarsh-Weyl
Pinhole imaging of small-scale auroral X-ray structures

Our group has developed a pinhole Anger camera to detect and image auroral X-rays in the energy range 20 - 120 keV. We have flow this camera on four different occasions and have imaged auroral zone X-rays from dawn, dusk, and noon. The fourth flight was from a circum polar navigating balloon from Antarctica. Our data, which sampled a small number of the dynamic auroral precipitation temporal forms, show that auroral X-rays persistently include small spatial structures of approximately equals 20 km (at ionospheric heights). Our camera obtained energy spectral information as a function of space and time and shows that precipitation includes at least two energy components, one with an e-folding energy of a few keV and another with an e-folding energy of tens of keV. These X-ray images 'remote sense' the distant magnetospheric sources and indicate that there are at least two different source populations.© (1992) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
Evaluating manufacturing system design and performance using the manufacturing system design decomposition approach

Abstract This paper uses the Manufacturing System Design Decomposition (MSDD) approach to contrast the design of the manufacturing systems at two North American automative component manufacturing plants. Instead of characterizing a manufacturing system on name alone as “mass” or “lean,” a system should be described in terms of the achievement of the manufacturing system requirements. The following analysis quantifies the performance of a “lean” plant relative to the performance of a “mass” plant based on the achievement of the system design requirements that are decomposed by the MSDD.
Most common intoxication in nephrology ward organophosphate poisoning.

Objectives. In Taiwan, the widespread use of organophosphates (OPs) in agricultural and household environments results in numerous OP poisoning. To better understand the clinical significance of as...
Player perception of delays and jitter in character responsiveness

Response lag in digital games is known to negatively affect a player's game experience. Particularly with networked multiplayer games, where lag is typically unavoidable, the impact of delays needs to be well understood so that its effects can be mitigated. In this paper, we investigate two aspects of lag independently: latency (constant delay) and jitter (varying delay). We evaluate how latency and jitter each affect a player's enjoyment, frustration, performance, and experience as well as the extent to which players can adjust to such delays after a few minutes of gameplay. We focus on a platform game where the player controls a virtual character through a world. We find that delays up to 300ms do not impact the players' experience as long as they are constant. When jitter was added to a delay of 200ms, however, the lag was noticed by participants more often, hindered players' ability to improve with practice, increased how often they failed to reach the goal of the game, and reduced the perceived motion quality of the character.
On a Liouville phenomenon for entire weak supersolutions of elliptic partial differential equations

Abstract We study a new Liouville-type phenomenon for entire weak supersolutions of elliptic partial differential equations of the form A ( u ) = 0 on R n , n ≥ 2 . Typical examples of the operator A ( u ) are the p-Laplacian for p > 1 , the mean curvature operator, and their well-known modifications.
Nonconsensual Sexual Experiences and Alcohol Consumption Among Women Entering College

The authors investigated the relationship between precollege nonconsensual sexual experiences (NSEs) and drinking among women entering college. College women (N = 797) at a midwestern university participated. Eighteen percent reported one or more NSE prior to arriving at college. Having a precollege NSE was associated with recent drinking, binge drinking, and negative drinking consequences. The authors discuss implications for intervention and prevention programs targeting college women.
Risk Management, Risk Capital, and the Cost of Capital

In a recent JACF article, Prakash Shimpi proposed a new way of calculating a firm's cost of capital that incorporated a concept of “risk capital” as well as operational capital. The premise of the Shimpi approach was that purchasing hedging instruments effectively “releases” equity that is no longer needed to ensure the firm's creditworthiness. This article shows that Shimpi's cost of capital calculations incorporate this released equity in a misleading way, exaggerating the capital base and underestimating its true cost. It also demonstrates how conventional cost of capital approaches can be modified to integrate risk capital, thereby avoiding such distortions and accurately representing the cost of capital of a company with a policy of active risk management.
Visualizing the kinetic power stroke that drives proton-coupled zinc(ii) transport

The proton gradient is a principal energy source for respiration-dependent active transport, but the structural mechanisms of proton-coupled transport processes are poorly understood. YiiP is a proton-coupled zinc transporter found in the cytoplasmic membrane of Escherichia coli. Its transport site receives protons from water molecules that gain access to its hydrophobic environment and transduces the energy of an inward proton gradient to drive Zn(II) efflux. This membrane protein is a well-characterized member of the family of cation diffusion facilitators that occurs at all phylogenetic levels. Here we show, using X-ray-mediated hydroxyl radical labelling of YiiP and mass spectrometry, that Zn(II) binding triggers a highly localized, all-or-nothing change of water accessibility to the transport site and an adjacent hydrophobic gate. Millisecond time-resolved dynamics reveal a concerted and reciprocal pattern of accessibility changes along a transmembrane helix, suggesting a rigid-body helical re-orientation linked to Zn(II) binding that triggers the closing of the hydrophobic gate. The gated water access to the transport site enables a stationary proton gradient to facilitate the conversion of zinc-binding energy to the kinetic power stroke of a vectorial zinc transport. The kinetic details provide energetic insights into a proton-coupled active-transport reaction.
Impact of Implantable Cardioverter‐Defibrillator Recalls on Patients' Anxiety, Depression, and Quality of Life

Background:In the past 2 years, multiple implantable cardioverter-defibrillator (ICD) manufacturers have issued recalls on ICD models due to the potential for serious malfunction and even patient death. Previous studies examining the relationship between these recalls and patients' psychological well-being have been limited by small sample size and conflicting results. The purpose of this study is to examine the association between ICD recalls and patients' anxiety, depression, and quality of life. Methods:Patients were drawn from an outpatient electrophysiology clinic at a tertiary care hospital in New York City. Patients who had devices subject to a recall (cases) were identified from lists provided by device manufacturer and controls (patients with ICDs not subjected to a recall) were drawn from a convenience sample of outpatients. The survey instrument consisted of two validated questionnaires–-Hospital Anxiety and Depression Score (HADS) and MacNew heart disease health-related quality of life (QOL) instrument. In addition, a series of Likert-type scales were designed to elucidate patients' concerns related to the following domains: anger, trust, hope, concerns regarding ICD shock, fear of death (FOD), and physicians' ability to reduce their concern about the ICD recall. Data were analyzed using simple descriptive statistics and bivariate analyses (χ2 and t-test) as appropriate. Result:Sixty-one cases and 43 control patients were enrolled. Thirty-two patients (52%) with devices subject to a recall opted for a generator replacement. There were no significant differences in the mean scores on the HADS scale, or the MacNew QOL scale between these two groups of patients (cases and controls). Subgroup analysis within the group of patients whose ICDs were recalled (cases) revealed a reduced QOL among patients with a class I recall (reasonable probability that the product will cause serious adverse health consequences or death) as compared to those with a class II recall (product may cause temporary or medically reversible adverse health consequences) (P = 0.01). Both cases and control patients reported having reduced trust in the health-care system. On the whole, however, patients were satisfied with the way their physicians dealt with the recall. There was no significant change in the overall concern of ICD shocks or FOD between the two groups. Conclusion:In this study of ICD recall, we found no difference in the levels of anxiety, depression, or QOL expressed by patients with an ICD subject to a recall as compared to those without. These findings may be a reflection of good physician-patient communication, which might have reduced any anxiety associated with recalls.
γ-Aminobutyric acid action in guinea-pig ileal myenteric plexus

The responses of the guinea-pig ileum myenteric plexus-longitudinal muscle preparation to gamma-aminobutyric acid (GABA) and several analogs were examined in direct and electrically stimulated preparations. GABA, muscimol and 3-aminopropane sulfonic acid (3-APS), but not baclofen, produced a transient, concentration-dependent contraction followed by relaxation. These responses were antagonized by atropine, tetrodotoxin, bicuculline methiodide and picrotoxin. Responses to GABA and 3-APS exhibited a marked tachyphylaxis. GABA and baclofen, but not muscimol or 3-APS, exerted a relaxant effect on contractions induced by supramaximal field stimulation in the longitudinal muscle. These responses were insensitive to bicuculline, bicuculline methiodide and picrotoxin, and were unaffected by other pharmacological agents including adrenergic, cholinergic and histamine antagonists. The results suggest that GABA and its analogs act at a population of excitatory receptors mediating the release of acetylcholine from enteric neurons, and at a population of inhibitory receptors which inhibit the stimulated release of acetylcholine.
Improvement in pulmonary function following antibiotics in infants with cystic fibrosis.

Background Recent studies have shown the presence of lung disease in even asymptomatic infants with cystic fibrosis (CF). While pulmonary function testing (PFT) is often used to follow progression of lung disease and guide treatment in older children with CF, little data is available on change in infant PFTs in young children with CF. Objective To determine change in infant PFTs before and after antibiotic therapy for pulmonary exacerbation in infants with CF. Methods Retrospective cohort study of infants with CF who underwent clinically indicated infant PFTs before and after antibiotic therapy for CF pulmonary exacerbation at the University of North Carolina at Chapel Hill. Results Pre- and post-antibiotics PFT data was available on 11 infants with CF, with a mean age of 102 weeks at time of first PFT. The majority of infants were symptomatic prior to antibiotics, and showed statistically significant improvement in clinical parameters following treatment. Prior to antibiotics, PFTs showed evidence of substantial obstructive disease (mean z-scores for FVC, FEV0.5, and FEF25-75 of −1.81, −3.06, and −4.5, respectively) and air-trapping/hyperinflation (mean z-scores for FRCpleth, RV, and RV/TLC of 8.86, 7.1, and 3.31, respectively). Following antibiotics, all of the above parameters showed statistically significant improvement. Discussion We have shown a statistically significant improvement in infant PFT measures following antibiotic therapy in a cohort of 11 infants with CF, which paralleled improvement in clinical parameters. Though infant PFTs showed improvement, they remained abnormal in the majority of subjects, with persistent air-trapping and hyperinflation after antibiotic therapy. Our findings suggest that infant PFTs are sensitive to acute clinical changes in children with CF, and may be a useful tool in managing infants with CF. Pediatr Pulmonol. 2012; 47:441–446. © 2011 Wiley Periodicals, Inc.
A survey of Michigan soils as related to possible boron toxicities

Abstract The saturation extraction method for measuring available B in soil provided variable results and a narrower range thus making this test more difficult to interpret than tests with the boiling water method. No close relationship between available soil B and either soil texture or soil pH level was found. The available B in soil ranged from 0.16 to 0.95 ppm with the highest level reflecting the recent use of B. The B level in the profiles of three typical sugarbeet‐bean soils ranged from none detectable in the subsoil to 0.54 ppm in the surface soil. A survey of cropped versus uncropped soils showed that, on the average, cropped soil contained two‐thirds as much B as uncropped soil, suggesting that more extensive B deficiencies may occur in the future. Soil test levels for B in a calcareous soil decreased rapidly after B application. In this experiment soil B levels in excess of 1.5 ppm represented a potentially toxic condition for beans while any level above 2.0 ppm represented a definite toxicity...
Atomically resolved surface structure of LaB6(100)

Abstract We have used scanning tunneling microscopy to obtain atomically resolved images of the lanthanum terminated LaB 6 (100) surface. The surface atoms are observed to occupy a square lattice with a LaLa separation of 4 A. A weak corrugation between La atoms is observed which is consistent with the delocalized metal-like nature of the states near the Fermi level. On a larger scale, the surface is composed of (100) terraces with an average width of 125 A separated by steps one unit cell high. Approximately 10% of the La sites on the terraces are vacant.
The effect of pyridine on the in vitro and in vivo metabolism of ethyl carbamate (urethane) by rat and mouse

Ethyl carbamate (EC, urethane) is a known carcinogen in laboratory animals. A genotoxic mechanism has been proposed which involves the bioactivation of EC to a reactive epoxide by the ethanol-inducible CYP2E1. The purpose of this study was to determine if pyridine (200 mg/kg i.p.), an inducer of CYP2E1, would increase the in vitro metabolism of EC and the in vivo binding of EC to cellular macromolecules. Treatment of rats or mice with pyridine increased hepatic microsomal metabolism of [14C-carbonyl]EC to CO2, but had little effect on pulmonary microsomal metabolism. The increase in hepatic metabolism was inhibited by the CYP2E1 inhibitor diethyldithiocarbamate, but not by the esterase inhibitor paraoxon, clearly indicating a role for this isozyme in hepatic metabolism of EC. In vivo, pyridine (200 mg/kg i.p.) administered 18 h prior to dosing with EC decreased the binding of [14C-ethyl]EC to cellular macromolecules. These data indicate that pyridine administration to rats and mice induces CYP2E1 metabolism of EC in vitro, but inhibits EC metabolism in vivo, perhaps by acting as an alternate substrate for CYP2E1.
Rainfall measurements using satellite downlink attenuation

The attenuation of a commercial satellite link signal at Ku-band is used for estimating rainfall rate along the link path. Comparisons with rainfall accumulations obtained using simultaneous radar measurements along the same path show good agreement. This method can potentially be used to complement other rainfall accumulation measurements obtained with radar and rain gauges in urban settings and areas with complex terrain.
Isotopic fractionation of mercury induced by reduction and ethylation

Isotope ratio measurements characterizing 202Hg/200Hg in NIST SRM 3133 Mercury Standard Solution were undertaken by multicollector inductively coupled plasma mass spectrometry employing NIST SRM 997 Tl for mass bias correction by use of the slope and the intercept obtained from a natural logarithmic plot of each session of measurements of 202Hg/200Hg against 205Tl/203Tl. The calculated value of 1.285333 ± 0.000192 (mean and one standard deviation, n = 40) for the mass bias corrected 202Hg/200Hg was then used for mass bias correction of other Hg isotope pairs. Ratios of 0.015337 ± 0.000011, 1.68770 ± 0.00054, 2.3056 ± 0.0015, 1.3129 ± 0.0013, 2.9634 ± 0.0038, and 0.67937 ± 0.0013 (expanded uncertainty, k = 2) were obtained for 196Hg/198Hg, 199Hg/198Hg, 200Hg/198Hg, 201Hg/198Hg, 202Hg/198Hg, and 204Hg/198Hg, respectively. Reduction of Hg(II) to Hg0 in solutions of SRM 3133 was then undertaken using SnCl2, NaBH4, UV photolysis in the presence of formic acid, and ethylation of Hg(II) using NaBEt4. These reactions induced significant isotope fractionation with maximum values of 1.17 ± 0.07, 1.08 ± 0.09, 1.34 ± 0.07, and 3.59 ± 0.09‰ (one standard deviation, 1SD, n = 5) for δ 202/198Hg relative to the initial isotopic composition in the solution following 85–90% reduction of the Hg by SnCl2, NaBH4, UV photolysis, and ethylation with NaBEt4, respectively. Mass-dependent fractionation was found to be dominant for all reduction processes.
Topological doping and the stability of stripe phases

We analyze the properties of a general Ginzburg-Landau free energy with competing order parameters, long-range interactions, and global constraints (e.g., a fixed value of a total {open_quotes}charge{close_quotes}) to address the physics of stripe phases in underdoped high-T{sub c} and related materials. For a local free energy limited to quadratic terms of the gradient expansion, only uniform or phase-separated configurations are thermodynamically stable. {open_quotes}Stripe{close_quotes} or other nonuniform phases can be stabilized by long-range forces, but can only have nontopological (in-phase) domain walls where the components of the antiferromagnetic order parameter never change sign, and the periods of charge and spin-density waves coincide. The {ital antiphase} domain walls observed experimentally require physics on an intermediate length scale, and they are absent from a model that involves only long-distance physics. Dense stripe phases can be stable even in the absence of long-range forces, but domain walls always attract at large distances; i.e., there is a ubiquitous tendency to phase separation at small doping. The implications for the phase diagram of underdoped cuprates are discussed. {copyright} {ital 1999} {ital The American Physical Society}
Fractal discrimination of MRI breast masses using multiple segmentations

Fractal dimension (fd) of lesion borders has been proposed as a feature to discriminate between malignant and benign masses on MR breast images. The fd value is computed using a sample space of fractal models, an approach that reduces sensitivity to signal noise and image variability. The user specifies a rectangular region of interest (ROI) around the mass and the algorithm generates a segmentation zone from the ROI. Fractal models are constructed on multiple threshold intensity contours within the segmentation zone. Preliminary results show that the combination of statistical fd feature and expert-observer interpretations improves separation of benign from malignant breast masses when compared to expert-observer interpretations alone. The statistical fd feature has been incorporated into a prototype computer-aided-diagnosis (CAD) system that outputs the following to assist the diagnostician in determining clinical action: (1) A likelihood-of-cancer measure computed from fd and reader interpretations, (2) A binary categorical value indicating whether a test case is fd- highly suspicious or fd-inconclusive, (3) The ROI with portions of the mass border with the most cancer-like fractal characteristics highlighted.
Consequences of the growth and division model for mitochondria assuming no cellular control.

Under the assumption that the mitochondria of a cell are independently existing organisms their population size is modeled by a probabilistic branching process and, as with any colony of organisms, can conceivably die out. From the calculation of the probabilityP that a cell normally havingN=4 and 8 mitochondria could arise devoid of mitochondria either by extinction or by maldistribution and subsequent cell division, it is inferred that for known cell mitochondrial numbersP is vanishingly small. Therefore chance alone is adequate to explain the inclusion of mitochondria in both daughter cells during cell division.
Analytic Solution of Ray Equations in Cylindrically Inhomogeneous Guiding Media. Part 2: Skew Rays

Analytic solutions are found for skew ray paths in inhomogeneous cylindrical systems such as GRIN rods and gas lenses, which focus rays by virtue of a gradual radial decrease in refractive index. The solutions are obtained by employing digital computers to carry out analytic, as opposed to numerical, calculations.
Contribution ofp-wave (3)+1 subamplitudes to4He binding energy and scattering observables below four-body breakup threshold

The four-body equations of Alt, Grassberger and Sandhas, in the form that the (2)+(2) subsystem amplitudes are treated by the convolution method, are solved for separable two-body interactions between nucleon pairs in the channels3S1-3D1 (t00 alone) and1S0. AllL=0 andL=1 (3)+1 subamplitudes are represented in a separable form using the energy dependent pole expansion. The contribution ofp-wave (3)+1 subamplitudes to the4He binding energy, threshold scattering observables and low energy cross sections forn3H→n3H,p3He→p3He,dd→dd anddd→p3H reactions is studied for different two-body potentials.
GENERALIZED IMMERSIONS AND THE RANK OF THE SECOND FUNDAMENTAL FORM

Partial differential equations and differential geometry come together in the idea of a generalized immersion. This concept, defined by means of Grassmann bundles and contact forms, allows for ?immersions? with ?singularities.? Sophus Lie?s generalized solutions to partial differential equations are an important special case. The classical second fundamental form has a natural generalization in the context of generalized immersions. The rank of the form is then meaningful. A constant rank assumption on the generalized second fundamental form leads to a natural foliation of the generalized immersion, at least when the ambient space is a space of constant curvature. Questions about the total geodesy and regularity of the foliation are also addressed.
1012-107 Monocyte Chemotactic Protein-1 Expression in Smooth Muscle Cell Cultures Derived from Human Coronary Arteries

Peripheral blood monocytes and monocyte-derived macrophages are believed to playa pivotal role in the development of early atherosclerotic lesions. Excessive smooth muscle cell (SMC) proliferation leads to coronary restenosis after interventional procedures. We postulate that monocyte chemotactic protein-1 (MCP-1), by attracting monocytes to the site of vascular injury may indirectly augment this process. We also hypothesize that MCP-1 expression by human SMC may be mediated bycytokines and growth factors. Accordingly, we studied SMC cultures derived from tissue obtained by directional coronary atherectomy, evaluating MCP-1 expression by Northern blot analysis. Cells were grow in M-199 medium to over 95% confluence, for the last 24 hrs in serumless medium. MCP-1 expression was assessed in unstimulated (control) cells, and after 6 hrs stimulation with platelet derived growth factor (PDGF), insulin-like growth factor-1 (IGF-1) and tumor necrosis factor alpha (TNFα). Autoradiographs were developed, scanned and digitized using NIH 1.53b10 software. Our findings suggest that unstimulated human coronary SMC derived cultures express MCP-1 and furthermore this expression is markedly increased after stimulation with cytokines (by 21.4% after stimulation with PDGF, 30.3% after IGF-1 and 119.1% after TNFα). Download : Download high-res image (118KB) Download : Download full-size image Conclusions SMC cultures derived from human coronary samples obtained by DCA express MCP-1 during their quiescent phase, and this expression is markedly increased by the cytokines PDGF, IGF-1 and TNFα. Thus by attracting monocytes to the area of vascular injury, MCP-1 may be intimately involved in coronary restenosis, playing an important role in the pathophysiology of this process.
Humans exposed to polychlorinated biphenyls (PCBs) and polychlorinated dibenzofurans (PCDFs) exhibit increased SCE frequencies in lymphocytes when incubated with α-naphthoflavone: Involvement of metabolic activation by P-450 isozymes

Abstract Our studies have shown that human exposure to cigarette smoke and polychlorinated biphenyls and dibenzofurans confers an increased sensitivity of lymphocytes to form SCEs following in vitro exposure to α-naphthoflavone (ANF). Studies of ANF metabolism by uninduced, phenobarbital and TCDD induced microsomes demonstrate that TCDD induced microsomes efficiently metabolize ANF, and that cytochrome P-450c is the isozyme responsible for its metabolism. The clastogenic properties of ANF, following metabolism by TCDD induced rat liver microsomes were characterized in Chinese Hamster Ovary (CHO) cells and it was determined that ANF can produce increased SCEs, chromosomal aberrations, β-thioguanine resistant mutants and ANF-DNA adducts.
Measurement of terahertz pulses using Electronically Controlled Optical Sampling (ECOPS)

We demonstrate generation and detection of single-cycle terahertz pulses using Electronically Controlled Optical Sampling (ECOPS). This technique is similar to asynchronous optical sampling (ASOPS), but is better suited for lower repetition-rate lasers.
Hydrodesulfurization of Thiophene and Benzothiophene to Butane and Ethylbenzene by a Homogeneous Iridium Complex

Reaction of the dimer [Cp*IrHCl]2 (Cp* = η5-C5Me5) in benzene solution with either thiophene or benzothiophene at 90 °C in the presence of H2 gives the hydrogenolysis products [Cp*IrCl]2(μ-H)(μ-SC4H9) (1) and [Cp*IrCl]2(μ-H)[μ-S(C6H4)CH2CH3] (2), respectively, in high yields. Upon further thermolysis under H2, the completely desulfurized products, butane and ethylbenzene, can be made. Complexes 1 and 2 were characterized by single-crystal X-ray diffraction. In the absence of H2, reaction of [Cp*Ir HCl]2 with thiophene gives an additional trinuclear product [Cp*IrCl]3(H)(SC4H6) (3), which was also structurally characterized.
Industrial cluster analysis-backward or forward linkages?

Regional and urban analysts have applied cluster analysis to input-output data to gain information about interindustry structure. This information has been used in studies of industrial location, changes in interindustry structure, and agglomeration economies. An important distinction which is underemphasized, however, is the difference between demand-constrained and supply-constrained interindustry relationships. Industrial clusters generated from demand-constrained (backward) linkages are likely to be quite different from those generated from supply-constrained (forward) linkages. This paper explores this difference using demand-constrained, supply-constrained, and weighted (combination of demand- and supply-constrained linkages) Leontief inverses. The results suggest strongly the need for generating clusters based on both types of linkages in order to obtain an accurate picture of interindustry structure.
New Distributional Records for Three Species of Gammarid Amphipods

Nine species of the genus Gammarus are known from North America. Sympatric populations of Gammarus troglophilus Hubricht & Mackin, 1940, G. pseudo limnaeus Bousfield, 1958, and G. minus Say, 1818 occur in spring streams in southwestern Illinois and eastern Missouri. G. troglophilus has a somewhat well defined, restricted geographical range while ranges of G. minus and G. pseudo limnaeus are much broader. None of these recorded ranges extends into south western Tennessee, although G. minus minus exists in northwestern, central and eastern portions of the state (Holsinger, 1972). We herein report sympatric popu lations of these three species from three localities in Shelby County, Tennessee, well
Widowhood and mortality among the elderly: the modifying role of neighborhood concentration of widowed individuals.

The effect of death of a spouse on the mortality of the survivor (the “widowhood effect”) is well-established. We investigated how the effect of widowhood on mortality depends on the neighborhood concentration of widowed individuals in the United States. We developed a large, nationally representative, and longitudinal dataset from Medicare claims and other data sources characterizing 200,000 elderly couples, with nine years of follow-up (1993–2002), and estimated multilevel grouped discrete-time hazard models. In neighborhoods with a low concentration of widowed individuals, widowhood increased the odds of death for men by 22% and for women by 17%, compared to 17% for men, and 15% for women in neighborhoods with a high concentration of widowed individuals. Our findings suggest that neighborhood structural contexts – that provide opportunities for interacting with others and favoring new social engagements – could be potential modifiers of the widowhood effects and as such requires more systematic consideration in future research of widowhood effects on well-being and mortality.
Control of sexuality in Asplanchna brightwelli: threshold levels of dietary tocopherol and modification of tocopherol response by exogenous and endogenous factors

Ingestion of one prey rotifer containing about 0.02 pg tocopherol was sufficient to cause young amictic females to produce a high proportion of mictic daughters. Varying the concentration of emulsified tocopherol and the population density of amictic females suggested that mictic-female induction approached an all-or-nothing response at relatively high population densities and increased with population density only when population densities were very low. Amictic females hatching from resting eggs were less likely to produce mictic daughters than those hatching from parthenogenetic eggs.
On finitely accessible and finitely observable rings

Abstract Two classes of rings which occur in linear system theory are introduced and compared. Characterizations of one of them are given in terms of integral extensions and a Cayley-Hamilton type matrix condition.
Impact of the American College of Surgeons Oncology Group (ACOSOG) Z0011 trial on Clinical Management of the Axilla in Older Breast Cancer Patients: a SEER-Medicare Analysis

Background American College of Surgeons Oncology Group (ACOSOG) Z0011 demonstrated that eligible breast cancer patients with positive sentinel lymph nodes (SLN) could be spared an axillary lymph node dissection (ALND) without sacrificing survival or local control. Although heralded as a “practice-changing trial,” some argue that the stringent inclusion criteria limit the trial’s clinical significance. The objective was to assess the potential impact of ACOSOG Z0011 on axillary surgical management of Medicare patients and examine current practice patterns.