cssi/SciSciGPT-SciSciNet huggingface dataset:
The effect of thiols on the sulfhydryl content and nucleotide binding of thymidylate synthetase.

Summary Variability in the endpoints for catalytic sulfhydryl group modification, nucleotide binding, and ternary complex formation has been observed in thymidylate synthetase from amethopterinresistant Lactobacillus casei . Electrophoretic analysis of ternary complexes of various enzyme preparations revealed the presence of as many as three enzyme forms containing one, two, or no nucleotide binding sites or catalytic sulfhydryl groups per enzyme dimer. The relative quantities of multiple forms were dependent on exogenous thiols in the purification scheme, thus resulting in the variability in active site content obtained for thymidylate synthetase.
Parent-Child Reminiscing Locates the Self in the Past.

In this paper, we extend our social-cultural developmental model of autobiographical memory development (Nelson & Fivush, 2004) to discuss children's developing understanding of self and other as temporally extended in time. Parent-guided reminiscing about past events that includes discussion, comparison, and negotiation of internal states of self and other, and places these internal states in explanatory narratives of behaviour, allows children to construct a psychologically imbued representation of relations between past and present, and self and other. We provide a theoretical and empirical review in support of these arguments and end with directions for future research.
Managing hematopoietic stem-cell transplant resources: the case for outpatient transplantation

Over the past 20 years, a significant amount of healthcare has shifted from the inpatient to the outpatient setting. The drivers of this trend have been entrepreneurial physicians, and hospitals wh...
Adaptations of the spadefoot toad Scaphiopus couchi, to desert environments

Abstract 1. 1. By burrowing into the ground for approximately 10 months of the year, Scaphiopus couchi avoids the inclemencies of the desert environment, but simultaneously encounters the problems of food storage and water conservation. 2. 2. Emergiong S. couchi have body fluid concentrations as high as 600 mOsm/l, with urea accounting for approximately half of this concentration. Thus burrowed toads store nitrogenous wastes and conserve water. 3. 3. Field and laboratory data indicate that toads are capable of stroing fat and metabolizing it during hibernation. 4. 4. Blood pressure measurements on toads during dehydration indicate that water is lost principally from interstitial fluids. Stored, dilute bladder urine may be utilized by toads to replace deficits in body fluids.
Screening for diabetic retinopathy, revisited.

A PPROXIMATELY 20 YEARS AGO, IT WAS OBSERVED that diabetic patients at risk for loss of vision from severe retinopathy who might benefit from laser photocoagulation were not receiving appropriate ophthalmologic care.1 Based on models incorporating epidemiologic and clinical trial data, it was estimated that early detection and timely photocoagulation treatment of proliferative retinopathy and clinically significant macular edema (vision-threatening retinopathy) would result in a considerable amount of person-years of sight saved, would be “cost-effective,” and would reduce human suffering and lost productivity due to blindness.2 This resulted in the development of new guidelines recommending specific schedules for initial ophthalmic evaluation and for follow-
Pedogenic Fractionation and Bioavailability of Uranium and Thorium in Naturally Radioactive Spodosols

Plant uptake of radionuclides into the human food chain is one of many vectors used for calculating exposure rates and performing risk assessment. This study provides a pedogenic assessment of soil-plant relationships in terms of their relationships to nuclide bioavailability. The objectives of this study were (i) to identify assodations of U and Th with pedogenic fractions and with soil properties, and (ii) to evaluate U and Th bioavailability in terms of soil processes. We collected composite samples of leaves, stems, AE and Bs horizons from 10 plots containing a Spodosol with naturally high levels of 238 U and 232 Th. Additional replicate subsamples of fine (<63 μm) soil material were also extracted with citrate-bicarbonate-dithionite (CBD), ammonium oxalate (AO), sodium pyrophosphate (PP), and Mehlich reagent (M3). Concentrations of 238 U and 232 Th were determined for soils and plants by neutron activation analysis or by gamma spectroscopy. Results indicated that Th was translocated preferentially to plant leaves while U showed little preferential translocation. The CBD extractant removed the most U and Th from soils. The PP extraction ranked second for U, and AO ranked second for Th removal. The M3 extraction was equally inefficient in the removal of both U and Th. Neither Th, nor Th uptake, was closely assodated with organic fractions. In contrast, U distribution and plant uptake of U were more closely correlated to organically bound oxide fractions.
Holding Agencies Accountable for Efficiency Learning from Past Failures

Despite increasing public concern and dissatisfaction with the efficiency of government bureaucracies, there a refew existing means by which the public can hold agencies accountable for achieving greater efficiency. The accountability process can be viewed in terms of a simple feedback model: setting of standards, comparison of activities against those standards, and imposition of sanctions if the activities fall below standards. In carrying out each of these steps, the citizen as "consumer"of governmental efficiency can either act directly or rely on surrogates. Suggestions for improving accountability mechanisms focused on efficiency are evaluated in terms of the model. Trials of many approaches, such as oversight committees and voucher plans in education, have often had disappointing results because their design failed to separate the "standard-setting and monitoring" role from the "sanction-imposition" role. A lack of consumer information is the single greatest drawback in most proposed accountability...
Quantitative colorimetric measurement of cellulose degradation under microbial culture conditions

We have developed a simple, rapid, quantitative colorimetric assay to measure cellulose degradation based on the absorbance shift of Congo red dye bound to soluble cellulose. We term this assay "Congo Red Analysis of Cellulose Concentration," or "CRACC." CRACC can be performed directly in culture media, including rich and defined media containing monosaccharides or disaccharides (such as glucose and cellobiose). We show example experiments from our laboratory that demonstrate the utility of CRACC in probing enzyme kinetics, quantifying cellulase secretion, and assessing the physiology of cellulolytic organisms. CRACC complements existing methods to assay cellulose degradation, and we discuss its utility for a variety of applications.
A Joint Computational Respiratory Neural Network-Biomechanical Model for Breathing and Airway Defensive Behaviors

Data-driven computational neural network models have been used to study mechanisms for generating the motor patterns for breathing and breathing related behaviors such as coughing. These models have commonly been evaluated in open loop conditions or with feedback of lung volume simply represented as a filtered version of phrenic motor output. Limitations of these approaches preclude assessment of the influence of mechanical properties of the musculoskeletal system and motivated development of a biomechanical model of the respiratory muscles, airway, and lungs using published measures from human subjects. Here we describe the model and some aspects of its behavior when linked to a computational brainstem respiratory network model for breathing and airway defensive behavior composed of discrete “integrate and fire” populations. The network incorporated multiple circuit paths and operations for tuning inspiratory drive suggested by prior work. Results from neuromechanical system simulations included generation of a eupneic-like breathing pattern and the observation that increased respiratory drive and operating volume result in higher peak flow rates during cough, even when the expiratory drive is unchanged, or when the expiratory abdominal pressure is unchanged. Sequential elimination of the model’s sources of inspiratory drive during cough also suggested a role for disinhibitory regulation via tonic expiratory neurons, a result that was subsequently supported by an analysis of in vivo data. Comparisons with antecedent models, discrepancies with experimental results, and some model limitations are noted.
Picosecond interferometric technique for study of phonons in the Brillouin frequency range

Abstract We describe a new technique - picosecond interferometry - for the study of phonons in the Brillouin frequency range in transparent materials. This method makes possible the measurement of longitudinal phonon velocity and attenuation under conditions such that the conventional approach is not applicable.
The use of cyclin-dependent kinase inhibitors alone or in combination with established cytotoxic drugs in cancer chemotherapy.

Cyclin-dependent kinase (CDK) inhibitors are small molecule inhibitors of the kinases required for the orderly progression of cells, both normal and neoplastic, through the cell cycle. Because cell cycle dysregulation is such a common occurrence in neoplasia, the search for agents that might block cell cycle traverse has been the focus of intense interest. These efforts have led to the identification of a broad array of compounds that interfere directly with the function of CDKs. Two of these agents (flavopiridol and UCN-01) have now entered the clinical arena, and others are scheduled to do so in the near future. In preclinical studies, CDK inhibitors have shown the ability not only to block neoplastic cell proliferation, but also to induce, through a variety of mechanisms, programmed cell death. The latter capacity may stem from the diverse effects that CDK inhibitors exert on multiple kinases and apoptotic regulatory molecules. In addition, there is abundant preclinical evidence that CDK inhibitors can potentiate, generally in a dose- and sequence-dependent manner, the anti-tumor effects of many established cytotoxic agents. In clinical studies in humans, flavopiridol and UCN-01 have been shown to be tolerable, although clear evidence of single agent activity or enhancement of the efficacy of established agents has not yet emerged. This may reflect a failure to optimize drug schedules/pharmacokinetics, or to identify the critical molecular targets of these agents. Finally, in recent years, a rationale has emerged for combining CDK inhibitors with other molecularly targeted agents (i.e. differentiation-inducers and signal transduction modulators). Current research has basically two goals: (a) to identify CDK inhibitor concentrations and schedules that inhibit the growth of and induce apoptosis in specific tumor cell types; and (b) to establish a rational basis for combining CDK inhibitors with more conventional cytotoxic agents to enhance antitumor efficacy. This review gives a brief summary of such efforts, with an emphasis on agents and combinations that are in or near clinical development.
Litigation and Students With Disabilities: A Persistent Concern

Special education litigation remains a volatile area with significant practice implications. A review of the 2010 case law in the Special Educator identified discipline (manifestation determination, seclusion and restraints, harassment), evaluation/RTI, and postsecondary transition as specific areas of concern. School administrators should keep abreast of these developments to ensure that the rights of students with disabilities are observed, educational benefits are attained, and potential liability is minimized.
Case Studies of Diamond-Coated Tool Cutting Simulations: Coating Thickness and Cutting Speed Effects

Due to the interwoven effects in both diamond deposition and subsequent machining processes, the tool geometry and process parameters have compound effects on the thermal and mechanical states in diamond-coated cutting tools during machining. For example, increasing the coating thickness tends to increase deposition-induced residual stresses at the tool edge interface. Further, a thick coating will introduce a greater machining load due to an enlarged edge radius. However, it has not been investigated how the coating thickness affects the thermo-mechanical behaviors of diamond-coated tools during machining. In a previous study, finite-element based simulations were developed to conduct systematic analyses of diamond-coated tool cutting. In this work, the developed 2D cutting simulations that incorporate deposition residual stresses were applied to evaluate the coating thickness and cutting speed effects on the tool stress contours, tool temperatures as well as the interface stresses around a cutting edge. The major findings can be summarized as follows. (1) The coating thickness effect on the first principal stress is minor. A thicker coating can decrease cutting temperature effectively, but increase the thrust force noticeably. Additionally, a thicker coating is also favorable for the reduction of interface radial normal stresses around the cutting edge. (2) For a constant coated tool edge radius, decreasing the substrate edge radius (while increasing the coating thickness) will elevate the maximum first principal stresses but significantly reduce tool temperatures and the interface radial normal stresses. (3) The cutting speed has little effect on the first principal stresses, but strongly affects the cutting tool temperatures. Moreover, the interface radial normal stresses and circumferential stresses decrease with the increase of cutting speed, which is intuitive since higher cutting temperatures associated with a high cutting speed are expected to relieve high deposition stresses.Copyright © 2010 by ASME
Composite n–p semiconducting titanium oxides as gas sensors

Abstract Anatase and rutile thick films generated from the same source of titania were found to exhibit different types of conductivity upon exposure to CO and CH 4 at 600°C in a background of 5% O 2 /95% N 2 . Anatase behaved as a n-type semiconductor, with a decrease in resistance with reducing gas, whereas rutile exhibited p-type conductivity. The morphology of the particles were different, with anatase consisting of spherical particles of 100–200 nm dimensions, whereas rutile appeared as elongated rods of ∼1 μm lengths. The n-type behavior of anatase can be explained based on the oxygen vacancies. For explanation of the p-type behavior of rutile, impurities in the sample have to be taken into account. The impurity contents in both samples were similar, and doping of the lower valent impurities into the TiO 2 lattice should lead to creation of interstitial titanium defects. During anatase to rutile conversion at temperatures of 1000°C, the titanium interstitials can help incorporate excess oxygen, leading to formation of holes and p-type conductivity in the rutile phase. Resistance changes upon interaction of reducing gas with composites of anatase–rutile was also studied. It was found that samples with 4 followed a similar pattern. However, since the overall response of CH 4 was smaller than that of CO, the 75% rutile sample showed no change upon exposure to CH 4 , while exhibiting an n-type response to CO, indicative of a selective CO sensor at temperatures of 600°C. A polychromatic percolation model was developed to explain the electrical data. Two independent, parallel pathways involving the n-type anatase and p-type rutile were considered to be important in the conductivity. Using experimental data related to the extent of sintering, and appropriate particle sizes, the model predicted that n–n percolation would occur from 0 up to 94.5% rutile and p–p percolation would begin at 75.1% rutile. In between 75.1 and 94.5% rutile, both n- and p-pathways would percolate, resulting in the observed diminished changes in resistance.
Comparison of estimated glomerular filtration rate with estimated creatinine clearance in the dosing of drugs requiring adjustments in elderly patients with declining renal function

Abstract Background: The National Kidney Foundation's practice guidelines for chronic kidney disease recommend using the Modification of Diet in Renal Disease (MDRD) equation for calculating the estimated glomerular filtration rate (GFR). Objective: The purpose of this article was to compare the use of this estimated GFR with estimated creatinine clearance (CrCl) calculated using the Cockcroft-Gault equation (CG CrCl -Eq) in the dosing of drugs requiring adjustments in elderly patients with declining renal function. Existing as well as new serum creatinine assay standards were used. Methods: A PubMed literature search for all English-language articles published before November 2007 was conducted using the terms estimated glomerular filtration, GFR, modified diet in renal disease, MDRD, creatinine clearance, CrCl, drug dosing adjustment, renal impairment, human, and elderly . Mathematical comparisons of the age, race, and sex factors for these 2 equations (CG CrCl -Eq and MDRD) were performed, as well as a simulation of resulting values from these equations using various combinations of age, weight, and sex factors. Results: None of the articles identified found that the use of the MDRD equation in the elderly was better than the CG CrCl -Eq for estimating renal drug elimination. Substantial mathematical differences are inherent in these 2 prediction equations that make any clinical comparison quite difficult. Implementation of new creatinine assay standards will further confuse the use of these 2 equations for estimating GFR and for dosage adjustments in elderly patients with renal insufficiency. Conclusions: Although an MDRD equation may be useful for estimating GFR, the CG CrCl -Eq should still be used for drug dosage adjustments. The CG CrCl -Eq may require a slight “adjustment factor” to be applied using serum creatinine values measured by newly established assay procedures.
Signal Processing With Direct Computations on Compressively Sensed Data

Sparsity is characteristic of a signal that potentially allows us to represent information efficiently. We present an approach that enables efficient representations based on sparsity to be utilized throughout a signal processing system, with the aim of reducing the energy and/or resources required for computation, communication, and storage. The representation we focus on is compressive sensing. Its benefit is that compression is achieved with minimal computational cost through the use of random projections; however, a key drawback is that reconstruction is expensive. We focus on inference frameworks for signal analysis. We show that reconstruction can be avoided entirely by transforming signal processing operations (e.g., wavelet transforms, finite impulse response filters, etc.) such that they can be applied directly to the compressed representations. We present a methodology and a mathematical framework that achieve this goal and also enable significant computational-energy savings through operations over fewer input samples. This enables explicit energy-versus-accuracy tradeoffs that are under the control of the designer. We demonstrate the approach through two case studies. First, we consider a system for neural prosthesis that extracts wavelet features directly from compressively sensed spikes. Through simulations, we show that spike sorting can be achieved with $54\times$ fewer samples, providing an accuracy of 98.63% in spike count, 98.56% in firing-rate estimation, and 96.51% in determining the coefficient of variation; this compares with a baseline Nyquist-domain detector with corresponding performance of 98.97%, 99.69%, and 97.09%, respectively. Second, we consider a system for detecting epileptic seizures by extracting spectral-energy features directly from compressively sensed electroencephalogram. Through simulations of the end-to-end algorithm, we show that detection can be achieved with $21\times$ fewer samples, providing a sensitivity of 94.43%, false alarm rate of 0.1543/h, and latency of 4.70 s; this compares with a baseline Nyquist-domain detector with corresponding performance of 96.03%, 0.1471/h, and 4.59 s, respectively.
The Economic Potential of Dual Individualisation Methodologies

Cost-effective treatment of patients with bacterial infections can best be accomplished by facilitating a rapid response. Achieving a more rapid cure of the infection should result in reduced utilisation of healthcare resources. An innovative means of achieving a more rapid response to antibacterial therapy has been termed dual individualisation. Dual individualisation allows for the simultaneous consideration of the pharmacokinetic interaction between an antibacterial agent and a patient, with the pharmacodynamic interaction between the antibacterial agent and the bacterial pathogen. Integrating the pharmacokinetic parameter of area under the curve (AUC), with the pharmacodynamic measure of minimum inhibitory concentration (MIC) yields a ratio called the area under the inhibitory curve (AUIC). Clinical studies using dual individualisation to achieve a target AUIC24h of 125-250 have been performed with cephalosporins and fluoroquinalones. Economic evaluation of the results demonstrate that dual individualisation is cost-effective. Dual individualisation can be implemented in most practice setting using existing clinical data. Use of a computer model allows for cost-effective calculation of AUIC24h without having to measure serum drug concentrations of bacterial MIC. By adjusting antibacterial regimens to achieve a target AUIC, optimisation of antibacterial therapy can be achieved with resultant economic benefits.
Impact of colony morphologies and disinfection on biological clogging in porous media

Biological clogging of aquifers and other porous media during bioremediation, sand filtration, and aquifer recharge is a significant problem that is yet poorly understood and controlled. One major difficulty is the relatively few direct observations of clogging phenomena, which are required to adequately validate numerical models for predicting flow through porous media. Visualization of biological growth with time and accompanying reductions in hydraulic conductivity were obtained using two-dimensional micromodels of porous media. The micromodels were seeded with mixed microbial cultures to allow natural selection of dominant aerobic morphologies following continuous feed of culture media containing 1.36−1.69 mM acetate flowing at 0.9−3.6 m/day specific discharge velocity. Of the several different resulting colony morphologies, filaments dominated at pH 3, while biofilms and aggregates dominated at neutral pH. Conductivity decrease correlated with biological growth and morphology, and sudden conductivity...
Effect of rate and temperature on the tensile properties of double‐base propellant

The tensile properties of two cast and two extruded solid rocket propellants were studied at 25°C. and 50% R.H. over a range of failure times from 0.005 to 2500 sec. The effects of temperature were also investigated at the highest rate and at 0.1 in./in./min. over a range of −60 to 80°C. The results indicate that both temperature and rate of loading greatly affect the tensile properties of double-base propellants.
Synthesis of β-Functionalized Porphyrins via Palladium-Catalyzed Carbon−Heteroatom Bond Formations: Expedient Entry into β-Chiral Porphyrins

A procedure was developed for the preparation of beta-monobromo-tetraphenylporphyrin (BrTPP) in a greatly improved yield from the selective bromination of tetraphenylporphyrin (TPP) by NBS. BrTPP was successfully employed as a versatile synthon for convenient synthesis of a wide range of beta-monofunctionalized porphyrins with various heteroatom functionalities via palladium-mediated carbon-heteroatom bond formations. Examples include beta-amino, -amido, -oxo, and -mercaptoporphyrins from reactions with amines, amides, alcohols, and thiols, respectively. Applying the synthetic approach to chiral amides, beta-chiral porphyrins were effectively constructed.
Photochemical escape of oxygen from Mars: A comparison of the exobase approximation to a Monte Carlo method

Abstract The non-thermal escape of neutral O atoms from Mars at the current epoch is largely due to dissociative recombination of O 2 + : O 2 + ( v , J ) + e → O ∗ + O ∗ + Δ E . There are five energetically allowed channels of this reaction, with exothermicities, and thus O kinetic energies, that depend on the on electronic energies of the O atoms produced, on the vibrational and rotational state of the initial O 2 + ions, and on the ion and electron velocities. We here construct high and low solar activity models of the martian thermosphere/ionosphere for a solar zenith angle of 60°. The background neutral atmosphere comprises 12 neutral species, whose density profiles range from 80 to 700 km. We calculate the density profiles for 14 ions from 80 to 400 km for both eroded and non-eroded ionospheric models. Using previously described methods, we model the vibrational distribution of the O 2 + (v) ions as a function of altitude and compute the nascent kinetic energy distribution of the hot O atoms. We then predict the photochemical escape rate of O atoms from Mars in two ways: first by employing the exobase approximation, and second, by using a spherical Monte Carlo code, which tracks the energetic O atoms as they collide with other species in their paths from their initial production altitudes, energies and angles. The O atoms are assumed to escape if they reach 700 km with energies greater than the escape energy. We carry out these Monte Carlo calculations using two different approximations for the distribution of scattering angles in the center-of-mass frame. We first assume that the scattering is isotropic, and then we do the same calculations for a more realistic forward-scattering distribution. We find that the calculated O escape rates for the isotropic model are comparable to those for the exobase approximation, but that the escape rates for the more realistic forward scattering model are an order of magnitude larger.
Family strategies in a neoliberal world: Korean immigrants in Winnipeg

South Korean immigration to Canada has increased since the East Asian economic crisis of the late 1990s. Korean immigrants in Winnipeg chose the city for many reasons: the introduction of the Provincial Nominee Program, structural changes in the home country, and individual family strategies to provide better educational opportunities for their children. This article examines how changes in the current wave of globalization, at both global and local scale, have affected the migration of Koreans to Winnipeg, Canada and how individual households chose their immigration destination. This study contributes to understanding of the less popular immigrant destinations of Canada using a multiscalar analysis that includes household level. In addition to economic purposes and children’s education, changes of life style can be an important reason for immigrant location choice. Overall, the neoliberal economy in South Korea has pushed many Koreans to move to other countries, and the globalization of the Canadian economy has pulled nomadic middle-class members from other countries.
The impact of drug therapy on quality of life in headache and migraine.

Although headache is among the most common and costly disorders in primary care, our understanding of its direct impact on the quality of life of affected individuals is incomplete. While studies evaluating the role of headache on health-related quality of life and healthcare economics are starting to appear in the medical literature, the effect of pharmacotherapy in improving quality of life is only beginning to be studied. At present, studies evaluating health-related quality of life in patients with migraine who are undergoing treatment are limited to 3 agents: sumatriptan, flurbiprofen and diclofenac. Several studies have consistently indicated that these drugs benefit patients by improving key dimensions of health-related quality of life or patients’ sense of well-being to a significant extent. Given the magnitude of functional and emotional impairment associated with chronic headache disorders, assessing patients’ perceptions of their quality of life makes a useful contribution to the evaluation of therapeutic interventions and should supplement traditional clinical endpoints in determining the effectiveness of new drugs.
Particle pinch mitigated by radial currents in the electric tokamak

A dominant particle pinch is observed in Ohmic plasmas of the electric tokamak (ET) associated with enhanced poloidal rotation. The density increases dramatically, with strong profile peaking. In pinch dominated particle transport, the pinch velocity profile is determined from the Thomson density profile data. The pinching rate is controlled with soft gas puffing. Hard puffing produces inverted density profiles that do not pinch due to the MHD instabilities. The build-up time of the density is typically 1 s. Due to density accumulation in the absence of significant core fuelling, the characteristic Troyon limit (βN = βaB/I ~ 3,%, m, T, MA) is reached even in Ohmic plasmas. Density ramps are terminated by internal disruptions due to beta collapse without any significant radiative energy loss. The loop voltage remains low (0.4 V) during the ramp. Prior to, and during the ramp, we observe no reduction in the electrostatic fluctuations in the present experiments. Electrode biasing, using the J × B force, shows that the density accumulation can be reduced and even stopped through slowing the poloidal rotation (reducing the magnitude of the background negative Er). This observation is consistent with the presence of a 'viscous' pinch driven by the dominance of the radial electric field through ion mobility. Other neoclassical pinch mechanisms (i.e. Ware and thermoelectric) contribute to the density accumulation and are shown to be secondary effects as revealed by the radial current modulation effects. The easily achieved thermal Mach numbers are ±0.15 for poloidal and ±0.2 for toroidal rotation using the present biaser. There is no significant spontaneous toroidal rotation. The spontaneous poloidal rotation seen in Ohmic plasmas has the thermal Mach number Mp ~ 0.15 across the measured profile where r/a > 0.5. This rotation is sufficient to account for the observed radial pinch velocity.
Improvements urged in national hazard warning system, risk communication

The United States needs an adequate national warning system to alert people about natural and human-made hazards, several scientists told a forum on disasters at the U.S. National Academies of Science in Washington, D.C. on 31 October. They also urged other improvements in risk communication and understanding risk perception. While natural and human-made hazards can cause significant damages, so can improper risk communication, they said.
Influence of hydralazine consumption on allylamine induced myocardial fibrosis and hypertrophy in rats.

Abstract Consumption of allylamine-HCl by Long-Evans rats of either sex for periods of 4–8 mo produces myocardial fibrosis with cardiac hypertrophy. Allylamine ingestion promotes focal edema and necrosis of smooth muscle cells in the media of coronary arteries but not in the pulmonary, renal or hepatic vessels. Appreciable hypertrophy of the auricles occurs only in hearts with moderate to extensive ventricular fibrosis. Hydralazine supplementation is able to inhibit induction of medial hyalinosis in the coronary arteries and myocardial fibrosis by allylamine. The mechanism which would account for the protective effect of hydralazine against the toxicity of allylamine is not known.
Direct simulation of hypersonic flows over blunt wedges

The results of a numerical study of low-density hypersonic flow about cylindrically blunted wedges with body half-angles of 0, 5, and 10 deg are presented. Most of the transitional flow regime encountered during entry between the free molecule and continuum regimes is simulated for a re-entry velocity of 7.5 km/s by including freestream conditions of 70 to 100 km. The bodies are at zero angle of incidence and have diffuse and finite catalytic surfaces. Translational, thermodynamic, and chemical nonequilibrium effects are considered in the numerical simulation by utilizing the direct simulation Monte Carlo (DSMC) method. The numerical simulations show that noncontinuum effects such as surface temperature jump and velocity slip are evident for all cases considered. The onset of chemical dissociation occurs at a simulated altitude of 96 km for the configurations considered.
Instability of Elastic Filaments in Shear Flow Yields First-Normal-Stress Differences

Using slender-body hydrodynamics, we study the flow-induced deformation of a high-aspect-ratio elastic filament. For a filament of zero rest curvature rotating in a viscous linear shear flow, our model predicts a bifurcation to shape instabilities due to compression by the flow, in agreement with experimental observations. Further, nonlinear simulations of this shape instability show that in dilute solutions, flexibility of the fibers causes both increased shear thinning as well as significant nonzero first-normal-stress differences. These stress differences are positive for small-to-moderate deformations, but negative for large-amplitude flexing of the fibers.
Effect of single injections of heparin on postprandial hyperlipemia.

Abstract 1. 1. An attempt was made to determine and compare the duration of clearing effect of single doses of heparin administered intramuscularly, intravenously and subcutaneously after a fat meal. 2. 2. The doses of heparin and routes of injection as employed in this study do not alter to any significant extent the degree of postprandial hyperlipemia. 3. 3. “Rebound hyperlipemia” following intravenous heparin is again demonstrated. 4. 4. “Rebound hyperlipemia” occurs even though in vitro studies show continued lipoprotein lipase activity for several more hours. 5. 5. Benefit of multiple injections of heparin over a single dose is discussed.
Si/Si/sub 1-x/Ge/sub x/ valence band discontinuity measurements using a semiconductor-insulator-semiconductor (SIS) heterostructure

We have measured the valence-band discontinuity of strained Si/sub 1-x/Ge/sub x/ on [100] unstrained Si using p-Si/sub 1-x/Ge/sub x//Si/p-Si/sub 1-x/Ge/sub x/ semiconductor-insulator semiconductor (SIS) structures with Ge compositions in the range 10 >
The Relationship between dN/dS and Scaled Selection Coefficients

Numerous computational methods exist to assess the mode and strength of natural selection in protein-coding sequences, yet how distinct methods relate to one another remains largely unknown. Here, we elucidate the relationship between two widely used phylogenetic modeling frameworks: dN/dS models and mutation-selection (MutSel) models. We derive a mathematical relationship between dN/dS and scaled selection coefficients, the focal parameters of MutSel models, and use this relationship to gain deeper insight into the behaviors, limitations, and applicabilities of these two modeling frameworks. We prove that, if all synonymous changes are neutral, standard MutSel models correspond to dN/dS ≤ 1. However, if synonymous codons differ in fitness, dN/dS can take on arbitrarily high values even if all selection is purifying. Thus, the MutSel modeling framework cannot necessarily accommodate positive, diversifying selection, while dN/dS cannot distinguish between purifying selection on synonymous codons and positive selection on amino acids. We further propose a new benchmarking strategy of dN/dS inferences against MutSel simulations and demonstrate that the widely used Goldman-Yang-style dN/dS models yield substantially biased dN/dS estimates on realistic sequence data. In contrast, the less frequently used Muse-Gaut-style models display much less bias. Strikingly, the least-biased and most precise dN/dS estimates are never found in the models with the best fit to the data, measured through both AIC and BIC scores. Thus, selecting models based on goodness-of-fit criteria can yield poor parameter estimates if the models considered do not precisely correspond to the underlying mechanism that generated the data. In conclusion, establishing mathematical links among modeling frameworks represents a novel, powerful strategy to pinpoint previously unrecognized model limitations and strengths.
A standardized tool for assessing the quality of classroom-based shared reading: Systematic Assessment of Book Reading (SABR)

Abstract Participation in shared-reading experiences is associated with children's language and literacy outcomes, yet few standardized assessments of shared-reading quality exist. The purpose of this study was to describe the psychometric characteristics of the Systematic Assessment of Book Reading (SABR), an observational tool designed to characterize the quality of classroom-based shared-reading sessions in early childhood settings. Participants included 105 preschool teachers. The quality of teachers’ videotaped, whole-class shared-reading sessions was examined using the SABR. Reliability levels for each of the SABRs five constructs were examined, as well as delayed alternate-form reliability and inter-rater reliability. The tools’ factor structure and construct validity were also assessed. Findings provide initial validation and preliminary evidence that the SABR is a reliable and valid tool. Potential uses for early childhood researchers, teachers, and allied professionals are described.
Fast large-scale optimal power flow analysis for smart grid through network reduction

Optimal power flow (OPF) plays an important role in power system operation. The emerging smart grid aims to create an automated energy delivery system that enables two-way flows of electricity and information. As a result, it will be desirable if OPF can be solved in real time in order to allow the implementation of the time-sensitive applications, such as real-time pricing. In this paper, we present a novel algorithm to accelerate the computation of alternating current optimal power flow (ACOPF) through power system network reduction (NR). We formulate the OPF problem based on an equivalent reduced system and interpret its solution and the detailed optimal dispatch for the original power system is obtained afterwards using a distributed algorithm. Our results are compared with two widely used methods: full ACOPF and the linearized OPF with DC power flow and lossless network assumption, the so-called DCOPF. Experimental results show that for a large power system, our method achieves 7.01X speedup over ACOPF with only 1.72% error, and is 75.7% more accurate than the DCOPF solution. Our method is even 10% faster than DCOPF. Our experimental results demonstrate the unique strength of the proposed technique for fast, scalable, and accurate OPF computation. We also show that our method is effective for smaller benchmarks.
The 108,110,112Ru isotopes in the generalized collective model

Abstract Very recently two groups reported on the measurement of excitation energies and γ-ray branching ratios for the very neutron-rich 108,110,112 Ru isotopes. The experimental data were analyzed using the rigid triaxial rotor and the rotation-vibration models resulting in basically different conclusions about the essential physics of these nuclei. In order to try to resolve this matter we applied the generalized collective model to these isotopes: Our results are compared systematically to the available experimental data and to calculations within the two aforementioned models.
COMPLEXING OF RIBOFLAVIN AND ITS 2‐SUBSTITUTED ANALOGS WITH ADENOSINE AND OTHER 6‐SUBSTITUTED PURINE DERIVATIVES*

Fluorescence properties of riboflavin and its 2-substituted analogs and the quenching of fluorescence which occurs upon complexing with adenosine and other 6-substituted purine derivatives have been examined at different concentrations of interactants and hydrogen ion. The 6-substituted purines and their ribosides show varying degrees of association with riboflavin. Successive N-alkylation of the 6-amino group of purine ribosides leads to more stable complexing in the order ethyl > methyl > propyl with riboflavin and its analog. These results suggest that such groups, including the 6-amino group of adenine or adenine moiety of FAD, do not directly interact with flavins by hydrophobic or hydrogen bonding. Lowering the pH to above that required to protonate the isoalloxazine system disrupts the intermolecular complexes. Hence, only the unprotonated bases can form such complexes. The 2-substituted aminoriboflavins, as well as FAD, exhibit fluorescence optima upon changing pH. The species involved appear to be a non-fluorescent form with protonated isoalloxazine and amine or adenine portions at low pH, a fluorescent form with only the amine or adenine portions protonated at moderately acid pH, and a non-fluorescent form which is intramolecularly quenched at higher pH. The general electron donating properties of the amines may be the common reason for their quenching of fluorescence in inter- and intramolecular complexes with flavins.
Activity–Composition Relations in FeCr2O4–FeAl2O4 and MnCr2O4–MnAl2O4 Solid Solutions at 1500° and 1600°C

Activity–composition relations of FeCr2O4–FeAl2O4 and MnCr2O4–MnAl2O4 solid solutions were derived from activity–composition relations of Cr2O3–Al2O3 solid solutions and directions of conjugation lines between coexisting spinel and sesquioxide phases in the systems FeO–Cr2O3–Al2O3 and MnO–Cr2O3–Al2O3. Moderate positive deviations from ideality were observed.
Rotator cuff repairs in patients 62 years of age or older.

Abstract We retrospectively reviewed 105 consecutive patients aged 62 years and older who had undergone a repair of a rotator cuff tear to evaluate the efficacy of this surgery in patients in this age range. Six patients died, and 7 had less than 2 years of follow-up or were incapable of returning for examination. Ninety-two patients with 97 rotator cuff tears were re-examined. The average preoperative UCLA (University of California, Los Angeles) score was 12.9 (range 8 to 20), and the average postoperative score was 32.4 (range 12 to 35). Five patients (5%) had failure of the repair, accounting for the poor results. Severe complications included infection (1 patient) and brachial plexus stretch injury (1 patient). Four additional patients sustained minor complications, for an overall rate of 6%. Overall, 87% of patients had good or excellent results. Eight additional patients, while satisfied, were classified as fair. Of the 5 failures, 3 were revised to a satisfactory result. Thus 90 of the 92 patients in the study were satisfied with the result of the surgery at final follow-up. Rotator cuff repair in patients 62 years and older results in increased function, decreased pain, and satisfactory results. (J Shoulder Elbow Surg 2001;10:97-9.)
Myxomatous degeneration of the mitral valve

Abstract The clinical, hemodynamic and pathologic features of 5 cases of anatomically proved myxomatous degeneration of the mitral valve resulting in mitral regurgitation are presented. Four patients manifested refractory congestive failure. Examination revealed cardiomegaly, third and fourth heart sounds and a grade 3– 4 6 apical holosystolic murmur transmitted to the axilla. One patient had a late systolic murmur. None exhibited signs suggestive of Marfan's syndrome. On fluoroscopy, the left atrium and ventricle were enlarged without valvular calcification. Sinus rhythm and nonspecific ST-T wave changes were recorded on the electrocardiogram. The apex cardiogram showed prominent A waves. Intracardiac pressures (range in mm Hg) were: mean left atrial 16–46; left ventricular end-diastolic 9–25; mean pulmonary arterial 15–61; right ventricular end-diastolic, 5–29, mean right atrial 3–16. Cardiac output ranged from 2.5 to 6.9 liters/min (Fick method). Cineangiography demonstrated massive mitral regurgitation. Coronary cineangiograms were normal. At surgery, the mitral valve leaflets were observed to be quite flaccid and “floppy”. Papillary muscle and chordae tendineae were normal. There was no valvular calcification. Anatomy of the mitral leaflets demonstrated typical features of myxomatous degeneration including layers and foci of dense, hyalinized, relatively acellular collagen. Among the denser layers of collagen were loose, lightly stained zones with small fibrocytes. Myxomatous degeneration of the mitral valve should be considered among the causes of acquired mitral regurgitation.
Are global wind power resource estimates overstated

Estimates of the global wind power resource over land range from 56 to 400 TW. Most estimates have implicitly assumed that extraction of wind energy does not alter large-scale winds enough to significantly limit wind power production. Estimates that ignore the effect of wind turbine drag on local winds have assumed that wind power production of 2‐4 W m 2 can be sustained over large areas. New results from a mesoscale model suggest that wind power production is limited to about 1 W m 2 at wind farm scales larger than about 100 km 2 . We find that the mesoscale model results are quantitatively consistent with results from global models that simulated the climate response to much larger wind power capacities. Wind resource estimates that ignore the effect of wind turbines in slowing large-scale winds may therefore substantially overestimate the wind power resource.
A system approach to residual echo suppression in robust hands-free teleconferencing

This paper presents a system approach to the residual echo suppression (RES) problem in a noisy acoustic environment. We propose a method that takes advantage of our existing robust acoustic echo cancellation system in order to obtain a residual echo estimate that closely resembles the true, noise-free residual echo. To achieve improved RES during strong near-end interference (e.g., double talk), a psychoacoustic postfilter is also used. The simulation results show that our RES based on the system approach outperforms a conventional estimation method. Comparing the postfiltered output to the unprocessed one indicates that our proposed RES approach can raise the PESQ score by more than half a point.
Interprovincial Return Migration in China: Individual and Contextual Determinants in Sichuan Province in the 1990S

China's massive volume of and dramatic increase in migration have stimulated increasing research in this area. However, researchers have not paid sufficient attention to return migration until recently when the issue of migrant labor shortage in Southern China has been linked to return migration back to the rural areas. Taking advantage of information contained in the 1995 China 1% Population Sample Survey and the 2000 China Census, this paper provides a systematic analysis of interprovincial return migration to Sichuan province, one of the most important migrant-sending provinces in China. We focus on return migrant selectivity, the impact of local labor-market conditions and migration networks on return migration, and nonfarm work participation among return migrants. Return migration in the late 1990s shows positive selection on education and return migrants are more likely to engage in nonfarm work. The pattern for the early 1990s is just the opposite of what is observed in the late 1990s. Our multilev...