cssi/SciSciGPT-SciSciNet huggingface dataset:
Degradation studies of novel degradable starch-polyethylene plastics containing oxidized polyethylene and prooxidant

Linear low-density polyethylene films were prepared that contained native corn starch (7, 14, or 28%), low or high molecular weight oxidized polyethylene (15%), and a prooxidant mixture (18% POLYCLEAN II) that contains manganese and vegetable oil. For each mixture all components were first mixed at high temperatures in a twin-screw extruder and pelletized. The pellets were cast into films using a single-screw extruder. Oxidized-polyethylene addition did not impair the transparency and thickness of the films and did not reduce the percentage elongation, whereas significant reductions in film mechanical properties were observed. Thermal and photodegradation properties of each film were evaluated by 70°C forced-air oven treatment (20 days), by high-temperature, high-humidity treatment in a steam chamber (20 days), and by exposure to ultraviolet light (365 nm; 4 weeks). Changes in the mechanical properties of the films were determined by an Instron Universal Test Machine; in the carbonyl index, Fourier transform infrared spectroscopy; and in molecular weight, by high-temperature gel-permeation chromatography (HT-GPC). The addition of oxidized polyethylene, especially high molecular weight oxidized polyethylene, and up to 14% starch to the films significantly increased the rate of thermal and photodegradation.
Coulomb-Born calculation of the triple-differential cross section for inner-shell electron-impact ionization of carbon.

A Coulomb-Born approximation is used to compute the triple-differential cross section for electron-impact inner-shell (1s) ionization of carbon. We employ a perturbation series that allows the use of Coulomb waves with arbitrary ${\mathit{Z}}_{\mathrm{eff}}$ for the incoming, scattered, and ejected electrons. Most of the features of the triple-differential cross section observed experimentally are reproduced, even though these wave functions are distorted by an effective Coulomb potential and therefore do not satisfy the plane-wave boundary conditions at infinity. In order to explain some features that appear in the cross section, and in order to probe the validity of a dipole approximation, we make a multipole expansion of the transition matrix and show that the amplitudes of the multipole components are similar to those obtained in the Born approximation, while the relative phases of the multipoles differ greatly.
Characterization of Ash-Basin Waters from a Risk-Based Perspective

The purpose of this investigation was to characterize waters in ash basins of coal-fired thermoelectric power plants and to identify constituents of concern from an environmental risk-based perspective. The investigation incorporated results from literature review and from laboratory analysis of ash-basin waters. General chemistry and concentrations of major and trace elements were investigated. Risk was assessed for aquatic life by a risk quotient approach using environmental exposure and toxic effects concentrations. The following constituents of concern in ash-basin waters were identified by the risk quotient method: aluminum, cadmium, chromium, copper, iron, lead, mercury, selenium, and zinc. In addition, pH was considered a constituent of concern because the observed pH range for ash-basin waters exceeded the range indicating reproductive impairment or mortality for sentinel species used for toxicity evaluation. The results of this investigation can be used to assess potential effects (reasonable potential analysis) for receiving system aquatic biota as a consequence of exposure to ash-basin effluent and applied to developing remediation strategies. The constituents of concern are readily treatable, and ash-basin waters can be potentially reused within a power plant or for other purposes (e.g., irrigation or stream flow augmentation).
Simple Model of Electronic Correlation in Insulators

To facilitate calculation of the effects of electron-electron interaction in insulators, a dielectric model is developed analogous to one used by Overhauser to discuss correlation in metals. In this model the dynamical many-electron problem is replaced by a field-theoretic problem in which an electron interacts with a "plasmon" field representing the valence-charge distribution. For small wave vector $\stackrel{\ensuremath{\rightarrow}}{\mathrm{q}}$ the plasmon dispersion $\ensuremath{\omega}(\stackrel{\ensuremath{\rightarrow}}{\mathrm{q}})$ approaches the bulk plasma frequency; at large $\stackrel{\ensuremath{\rightarrow}}{\mathrm{q}}$, $\ensuremath{\omega}(\stackrel{\ensuremath{\rightarrow}}{\mathrm{q}})\ensuremath{\rightarrow}\frac{\ensuremath{\hbar}{\stackrel{\ensuremath{\rightarrow}}{\mathrm{q}}}^{2}}{2m}$, corresponding to single-particle excitations. To determine the electron-plasmon coupling Poisson's equation and the sum rule on oscillator strength are employed. Calculated self-energies of an electron (or hole) due to correlation are large, typically $\frac{1}{3}$ Ry, though substantially reduced by recoil effects if the electron mass is small. Exchange effects lead to further reduction. The crucial importance of short-range (large-$\stackrel{\ensuremath{\rightarrow}}{\mathrm{q}}$) dielectric behavior is emphasized.
Vaccinia Virus Gene A18R DNA Helicase Is a Transcript Release Factor

Prior phenotypic analysis of a vaccinia virus gene A18R mutant, Cts23, showed the synthesis of longer than wild type (Wt) length viral transcripts during the intermediate stage of infection, indicating that the A18R protein may act as a negative transcription elongation factor. The purpose of the work described here was to determine a biochemical activity for the A18R protein. Pulse-labeled transcription complexes established from intermediate virus promoters on bead-bound DNA templates were assayed for transcript release during an elongation step that contained nucleotides and various proteins. Pulse-labeled transcription complexes elongated in the presence of only nucleotides were unable to release nascent RNA. The addition of Wt extract during the elongation phase resulted in release of the nascent transcript, indicating that additional factors present in the Wt extract are capable of inducing transcript release. Extract from Cts23 or mock-infected cells was unable to induce release. The lack of release upon addition of Cts23 extract suggests that A18R is involved in release of nascent RNA. By itself, purified polyhistidine-tagged A18R protein (His-A18R) was unable to induce release; however, release did occur in the presence of purified His-A18R protein plus extract from either Cts23 or mock-infected cells. These data taken together indicate that A18R is necessary but not sufficient for release of nascent transcripts. We have also demonstrated that the combination of A18R protein and mock extract induces transcript release in an ATP-dependent manner, consistent with the fact that the A18R protein is an ATP-dependent helicase. Further analysis revealed that the release activity is not restricted to a vaccinia intermediate promoter but is observed using pulse-labeled transcription complexes initiated from all three viral gene class promoters. Therefore, we conclude that A18R and an as yet unidentified cellular factor(s) are required for thein vitro release of nascent RNA from a vaccinia virus transcription elongation complex.
Redispersion of uncoaleseed liquid—liquid drop dispersions

Abstract Further studies of a liquid—liquid system with low rates of coalescence have shown that for sieve plates the basic mechanism of drop break-up is through multiple jets forcing their way through the plate restrictions simultaneously forming thin jets that break up into small drops at distinct nodes. A range of nozzle sizes and flow rates were studied for the kerosene—water system resulting in a correlation for the number of drops occupying a given restriction at any time. This correlation was used in an improved model for predicting plate to plate distributions for these types of low coalescing systems. The results have important implications for the design of liquid—liquid sieve plate columns as the studies and the model show that after a very few plates (3 or 4) most of the drops will be very much smaller than predicted by other existing correlations for nozzle velocities from about 5 to 50 cm s −1 .
The PDP-8/I as a CAT

A programmed algorithm to compute a weighted ensemble average on a set of output signal realizations is presented. Thus programmed, the PDP-8/I can recover output signals, which are due to periodic input signals, from a noisy system. Arbitrarily, large enhancement of signal-to-noise ratio is attainable. The configuration used is a 4K PDP-8/I with AD08-B analog-to-digital converter.
Enumeration of Lozenge Tilings of Punctured Hexagons

We present a combinatorial solution to the problem of determining the number of lozenge tilings of a hexagon with sidesa,b+1,b,a+1,b,b+1, with the central unit triangle removed. Forab, this settles an open problem posed by Propp [7].
THE EFFECT OF BORIC OXIDE ON THE DEVITRIFICATION OF THE SODA-LIME-SILICA GLASSES. THE QUATERNARY SYSTEM, Na2O-CaO-B2O3-SiO21

Commercial glasses of the soda-lime-silica types do not consist solely of these three oxides, but in addition contain significant amounts of other constituents which arc introduced incidentally as impurities or deliberately for some beneficial influence. Such minor additions may have either a favorable or unfavorable influence on the tendency of the glass to devitrify, and an investigation into the effect of such minor components is desirable. Previous results with MgO and with A12O3 have shown that a systematic study of a four-component system is necessary to the understanding of its devitrification relations, and that arbitrary and fragmentary excursions into such a system give little insight into the general effect of the minor constituent and may be misinterpreted to erroneous conclusions as to the effect of this constituent on glasses of slightly different composition. Accordingly, in taking up the study of the effect of B2O3 on the devitrification of the soda-lime-silica glasses, it was added to 21 glasses in and near the field of devitrite, Na2O·3CaO·6SiO2, in the ternary system, Na2O–CaO-SiO2, in amounts up to about 5%. In all cases the liquidus temperature was lowered, and the tendency toward devitrification reduced. Both of these effects are desirable and add to the thermal stability of the glass. With glasses containing 10% CaO, initially in the field of tridymite or so near to it that a small addition of B203 brings the resulting glass into the tridymite field, this initial lowering is replaced by an increase in the liquidus temperature which passed through a maximum at from 4 to 6% B2O3. With all other glasses the lowering continues, and the rate of decrease is greatest with glasses originally in the field of Na2O·2CaO·3SiO2. An exploration of the quaternary system showed that no new compounds are formed in any mixture that can be obtained by adding B203 in amounts up to 50% to any mixture in or near the devitrite field. It also indicated the probability that a narrow band of immiscible liquids is formed, extending across the ternary system, CaO-B2O3–SiO2, and including the mineral danburite, CaO·B2O·2SiO2, but probably not extending far into the quaternary system. The fields of wollastonite and of Na2O·2CaO·3SiO2 were found to sweep out regions in the quaternary system extending over the square, Na2O·SiO2-Na2O·B2O3-CaO-B2O3-CaOSO2, and the field of Na2O·CaO·SiO2 was found to extend over the middle of this square, and is probably adjacent to the fields of wollastonite and of Na2O· 2CaO·3SiO2. A compound is formed between Na2O·B2O3 and CaO·B2O3. There is included a general survey of the literature relative to the effect of B203 on the properties of glass.
PREDICTING ORAL ANTICOAGULANT RESPONSE USING A PHARMACODYNAMIC MODEL

We developed a pharmacokinetic and pharmacodynamic model of warfarin absorption, metabolism, and anticoagulant action appropriate for guiding anticoagulant therapy. The model requires only two independently adjustable parameters to describe warfarin's effect on individual patients. For any given individual, these parameters are rapidly and inexpensively identified using a computer program based on the model. Test data were generated by superimposing Gaussian noise on dose-response curves calculated with the model. Then the computer program was applied to the test data. Future prothrombin complex activities (PCA "s) and maintenance doses were predicted accurately early in the course of drug administration. In addition, the program accurately predicted PCA response in two groups of normal volunteers.
The relation of farm size and government programme benefits: an application of data envelopment analysis to policy evaluation

Data envelopment analysis is used to establish comparisions of maximum profit without and with participation in government progarammes. A measure of a farm's ability to survive, returns on equity, is used to measure the benefit received from participation in government programmes. Density functions are estimated with kernel density estimation using bootstrap samples, and weighted regressions are used to test density estimation using bootstrap samples, and weighted regressions are used to test the equality of mean benefits between different size groups. The results indicate that almost all farms that could be considered of commercial size receive the same benefit from participation in government programmes.
Expected Value and Variance of Failure Time in Redundant Systems

Formulas are derived for the mean value and the variance of the distribution of time to system failure for parallel redundant and m out of n systems. A novel approach is used in the derivation which requires only elementary calculus and no explicit integration of specific functions. For the general case component failure times are assumed to be statistically independent and exponentially distributed. In addition, a special case of statistical dependence is treated.
Oxygen alveolopathy in adults.

Ample clinical and experimental evidence indicates that prolonged exposure to high concentrations or partial pressures of oxygen may produce an exudative alveolar reaction progressing to interstitial pulmonary fibrosis. Initially this process appears roentgenographically as a diffuse alveolar infiltrate. With progression to the proliferative phase of the disease, a more linear and nodular pattern is observed. No characteristic roentgen features allow specific diagnosis. Emphasis is placed upon the inclusion of oxygen alveolopathy in the differential diagnosis of widespread pulmonary infiltrates in patients who receive respirator therapy. Six examples of this condition in adults are reported.
Raman and fluorescence spectroscopic evaluation of NIR laser-welded human and porcine aorta tissues

ABSTRACT Laser tissue welding involves the partial denaturing and renaturing of the collagen triple helical structure. Although themechanisms of laser tissue welding are not well understood, water in tissues plays an important role in the process. Highquality welding of human and porcine aorta tissue have been achieved using NIR lasers tuned to the water absorption bandaround 1450 nm. Fluorescence and Raman spectra from welded and non-welded regions are compared for ex vivo humanand porcine aorta tissues. The fluorescence from the outer surface of welded aorta was substantially weaker than thefluorescence from the non-welded region. The Raman spectra from the welded and non-welded tissue regions appearedsimilar in the energies of the observed vibrational levels but the intensity of the fluorescence wing was considerably greaterfrom the outer surface of the welded region as compared to the non-welded region. For the outer surface of the aorta, theemission intensity from the welded region was larger than for the non-welded region.Key Words: Tissue welding, collagen, fluorescence, Raman spectroscopy
Random telegraph noise from magnetic nanoclusters in the ferromagnetic semiconductor (Ga,Mn)As

The canonical ferromagnetic semiconductor Ga1 xMnxAs is an interesting material at the confluence of several contemporary issues in condensed matter physics, ranging from spintronics to localization to correlated electron physics.[1] Point defects – specifically Mn interstitials (MnI) and As antisites – play an important role in the complex interplay between ferromagnetism and electronic structure in this material. Both these defects are donors that compensate the holemediated ferromagnetic exchange and hence suppress ferromagnetic order.[2] Theoretical calculations have also predicted that MnI – in addition to compensating holes – may quench ferromagnetism because of antiferromagnetic coupling with neighboring substitutional Mn atoms.[3] However, there is no explicit experimental evidence for such a coupling or for any magnetic activity of MnI. In this paper, we present electrical noise measurements that suggest Mn interstitials are magnetically active in nanoscale clusters, providing a fluctuating moment that interacts with carrier transport. Electrical noise provides a powerful probe into the physics underlying the coupling between spin and charge transport in complex magnetic materials such as the manganites [4, 5, 6, 7] and spin glasses.[8] Our measurements of electrical noise provide new glimpses into the interplay between spin transport, hole localization and Mn interstitials in the ferromagnetic semiconductor Ga1 xMnxAs under conditions of modest localization. We find that the resistance noise is characterized by a power spectral density (PSD) with either 1/f frequency dependence or a Lorentzian frequency dependence, depending on the nature of the disorder in the sample. In strong contrast with the manganites where a distinct enhancement of noise has been reported across the Curie temperature (TC), we do not observe any measurable change in the temperature-dependent noise characteristics near TC. Instead, we find a pronounced enhancement of the noise at low temperatures (T . 25 K), coinciding with increasing localization. Samples with a high density of MnI defects show random telegraph noise (RTN) created by a small number of two-level fluctuators with an energy gap that is linear in magnetic field: we interpret this as evidence for nanoscale magnetic clusters whose spin flip fluctuations modulate transport in the Mn impurity band[9] and result in two possible states with different conductivity for hopping holes. In contrast to superficially similar observations in (Ga,Er)As samples containing ErAs nanoclusters,[10] high resolution transmission electron microscopy measurements of these Ga1 xMnxAs samples do not show any observable
A system for scalable visualization of geographic archival records

We present a system that visualizes large collections of archival geographic records. This system is comprised of a data grid containing a 60TB test collection gleaned from the US National Archives, and three web-applications: an indexer and two web and mobile-device based visualizations focusing on collection understanding in a geographic context.
Synthesis of Zirconium Pinacolate and Mechanism of Its Thermal Transformation to ZrO2: Impact of a Vicinal Diol Ligand

Reaction of Zr2(OiPr)8(HOiPr)2 with a slight excess of pinacol (HOCMe2CMe2OH) yields Zr2(OCMe2CMe2O)2(OCMe2CMe2OH)4, as confirmed by X-ray crystallography. Inter- and intramolecular hydrogen bonding results in the polymeric solid-state structure and the subsequent nonvolatility and reduced solubility of the species. The thermal transformation of zirconium pinacolate occurs in two distinct steps, as seen by the thermal gravimetric analysis (TGA), and occurs at <300 °C, yielding ZrO2, as determined by X-ray powder diffraction. GC−MS analysis of the thermolysis byproducts reveals six species: pinacol, pinacolone, 2,3-dimethyl-2-butene (tetramethylethylene) (trace amounts), 2,3-dimethylbutadiene (DMBD), 2,3-dimethyl-3-buten-2-ol (DMB-ol), 2,2,5,6,6-pentamethyl-4-hepten-3-one (PMH), and 1,3,5-tri-tert-butylbenzene (TTB). Real-time monitoring of the thermal transformation is achieved by carrying out the experiment inside a mass spectrometer. This novel experiment confirms that while only pinacol is lost in ste...
In Vitro Activity of Spectinomycin Against Recent Urinary Tract Isolates

Abstract The susceptibilities to spectinomycin of 303 recent urinary tract isolates were determined and compared to the susceptibilities of those strains to ampicillin, tetracycline, and gentamicin. Based on minimal inhibitory concentrations, 84% of Escherichia coli, Klebsiella, and Enterobacter, 31% of other Enterobacteriaceae, 7% of Staphylococcus aureus and Streptococcus (including enterococci), and 0% of Pseudomonas aeruginosa were susceptible to concentrations of spectinomycin that are easily surpassed in serum (≤32 μg/ml); 90% of all organisms tested other than P. aeruginosa were susceptible to concentrations that are easily surpassed in urine (≤128 μg/ml). Spectinomycin was active against more isolates than either ampicillin or tetracycline but against fewer isolates than gentamicin. Disk diffusion susceptibility tests did not reliably distinguish susceptible from resistant isolates with any of the four antibiotics studied.
Integrated melt pool and microstructure control for Ti–6Al–4V thin wall additive manufacturing

AbstractIn additive manufacturing (AM), melt pool dimension control is needed to accurately build a geometry and determine process precision. Microstructure control is needed for its effect on mechanical properties. This research addresses both for Ti–6Al–4V thin walled structures fabricated by wire feed electron beam AM. Model results show that beam power and beam velocity combinations yielding constant melt pool cross-sectional areas also yield constant solidification cooling rates. Experimental measurements back up this finding and show roughly 20 beta grains across the width of a thin wall deposit which is consistent with an earlier study of single bead deposits, suggesting that links between melt pool geometry and beta grain size are independent of deposition geometry, with significant implications for AM process control.
Nonlinear inverse perturbation method in dynamic analysis

On presente une methode analytique pour la re-conception automatisee des caracteristiques modales des systemes mecaniques non amortis. La methode est basee sur une perturbation du systeme propre et les termes non lineaires sont traites de facon a pouvoir tenir compte de grands changements
Activation of the carcinogens N-hydroxy-N-2-fluorenylbenzamide and N-hydroxy-N-2-fluorenylacetamide via deacylations and acetyl transfers by rat peritoneal serosa and liver

Intraperitoneally administered N-hydroxy-N-2-fluorenylbenzamide (N-OH-2-FBA) and N-hydroxy-N-2-fluorenylacetamide (N-OH-2-FAA) are carcinogenic for rat peritoneum. The potential of peritoneal serosa to activate these compounds via deacylations and acyl transfers was compared to that of liver. N-Deacylations of N-OH-2-FBA and N-OH-2-FAA to N-2-fluorenylhydroxylamine (N-OH-2-FA) were faster by liver than serosa and by microsomes than cytosols. N-Debenzoylations of N-OH-2-FBA were 73- to 123-fold faster than N-deacetylations of N-OH-2-FAA. The esters, N-benzoyloxy-2-FBA and N-acetoxy-2-FAA, were O- and N-deacylated to N-OH-2-FA by liver, and the benzoate by serosa. Inhibition by paraoxon of the above deacylations implicated a serine carboxylesterase. Liver and serosa cytosols catalyzed acetyl CoA-, but not benzoyl CoA-, dependent and iodoacetamide (IAA)-sensitive N-acylation of N-2-fluorenamine (2-FA), implicating an acetyltransferase. In hepatic microsomes this activity was IAA-insensitive and partially inhibited by paraoxon. Liver cytosol, but not microsomes, used N-OH-2-FAA as an acyl donor and neither used N-OH-2-FBA. Liver and serosa catalyzed binding to DNA of N-OH-2-[ring-3H]FBA which was paraoxon-sensitive and increased by acetyl CoA, but not benzoyl CoA. Binding to DNA of N-OH-2-[ring-3H]FAA catalyzed by cytosols was approximately 22-fold greater in liver than in serosa and was IAA-sensitive. Microsome-catalyzed binding of this compound in both tissues was increased approximately 2-fold by acetyl CoA. The results support a two-step activation of N-OH-2-FBA in the liver consisting of esterase-catalyzed N-debenzoylation to N-OH-2-FA and an acyltransferase-catalyzed O-acetylation to the putative electrophile N-acetoxy-2-FA. In the serosa, binding to DNA appears to be due to rapid N-debenzoylation to N-OH-2-FA, a fraction of which is O-acetylated. Whereas activation of N-OH-2-FAA by liver and serosa microsomes may also involve N-OH-2-FA and/or its O-acetate, activation by the cytosols is consistent with N,O-acetyltransfer of N-OH-2-FAA to yield N-acetoxy-2-FA. The study provides first evidence for activation of N-OH-2-FBA by rat liver and of both compounds by peritoneum in vitro.
Multiple seismic reflectors in Earth’s lowermost mantle

The modern view of Earth’s lowermost mantle considers a D″ region of enhanced (seismologically inferred) heterogeneity bounded by the core–mantle boundary and an interface some 150–300 km above it, with the latter often attributed to the postperovskite phase transition (in MgSiO3). Seismic exploration of Earth’s deep interior suggests, however, that this view needs modification. So-called ScS and SKKS waves, which probe the lowermost mantle from above and below, respectively, reveal multiple reflectors beneath Central America and East Asia, two areas known for subduction of oceanic plates deep into Earth’s mantle. This observation is inconsistent with expectations from a thermal response of a single isochemical postperovskite transition, but some of the newly observed structures can be explained with postperovskite transitions in differentiated slab materials. Our results imply that the lowermost mantle is more complex than hitherto thought and that interfaces and compositional heterogeneity occur beyond the D″ region sensu stricto.
Characterization of Helicobacter pylori gamma-glutamyltranspeptidase reveals the molecular basis for substrate specificity and a critical role for the tyrosine 433-containing loop in catalysis.

Helicobacter pylori γ-glutamyltranspeptidase (HpGT) is a member of the N-terminal nucleophile hydrolase superfamily. It is translated as an inactive 60 kDa polypeptide precursor that undergoes intramolecular autocatalytic cleavage to generate a fully active heterodimer composed of a 40 kDa and a 20 kDa subunit. The resultant N-terminus, Thr 380, has been shown to be the catalytic nucleophile in both autoprocessing and enzymatic reactions. Once processed, HpGT catalyzes the hydrolysis of the γ-glutamyl bond in glutathione and its conjugates. To facilitate the determination of physiologically relevant substrates for the enzyme, crystal structures of HpGT in complex with glutamate (1.6 A, Rfactor = 16.7%, Rfree = 19.0%) and an inactive HpGT mutant, T380A, in complex with S-(nitrobenzyl)glutathione (1.55 A, Rfactor = 18.7%, Rfree = 21.8%) have been determined. Residues that comprise the γ-glutamyl binding site are primarily located in the 20 kDa subunit and make numerous hydrogen bonds with the α-amino and α-...
Role of My Cooperation with Soviet Scientists in the Elimination of Polio: Possible Lessons for Relations between the U.S.A. and the USSR

The purpose of this communication is threefold: (1) to bring into perspective the important role ofmy cooperation with Soviet scientists in the development of the oral poliovirus vaccine used for more than 25 years for the elimination of paralytic poliomyelitis; (2) to describe the obstacles to worldwide eradication of the disease; and (3) to describe a hope I have derived from this experience that cooperative endeavors between the U.S.A. and the Soviet Union against the larger common enemy of poverty in more than half the world's population may become a means of breaking the dangerous impasse ofjustifiable, mutual distrust that causes the U.S.A. and the USSR to continue preparing for a barbaric war against each other, a war that neither nation wants and the whole world dreads, a war that cannot be won but can lead to the greatest tragedy ever inflicted on the human species. Some people think that poliomyelitis, the crippling disease that has been part of the human heritage since earliest evolutionary times, has already been conquered, that is, eliminated, brought under control, or even eradicated. This conception is partly true and partly false. It is true for about 2,000 million of the world's population living in temperateclimate countries where it is reasonably estimated that during the past 20 years the oral polio vaccine has prevented about 5 million cases ofpersistent paralysis and perhaps 500,000 deaths [I]. But it is not true for most tropical and subtropical, economically undeveloped countries inhabited by about 3,000 million people, where much polio has undoubtedly been This paper is a slightly modified version of the Twenty-third Cosmos Award Lecture presented April 15, 1986, at the Cosmos Club, Washington, D.C. ?Fogarty International Center for Advanced Studies in the Health Sciences, National Institutes of Health, Bethesda, Maryland 20892.
Strategies for efficient operation of furnaces using nitrogen-base atmospheres

To minimize the cost of operating furnaces using protective atmospheres formed from nitrogen plus a reducing gas, both the flow rate of atmosphere gas and the amount of added reducing gas must be controlled. Optimum parameters for steady state operation are determined by (1) the type of atmosphere desired— nonoxidizing (but decarburizing), or neutral, (2) the necessity for maintaining a positive furnace pressure, and (3) the rate of air leakage into the furnace. In general, low flow rates of atmosphere gas and small additions of reducing gas are best for steady state operations.
A simple, fast, and effective LL(1) error repair algorithm

Validation and locally least-cost repair are two simple and effective techniques for dealing with syntax errors. We show how the two can be combined into an efficient and effective error-handler for use with LL(1) parsers. Repairs are computed using an extension of the FMQ algorithm. Tables are created as necessary, rather than precomputed, and possible repairs are kept in a priority queue. Empirical results show that the repairs chosen with this strategy are of very high quality and that speed is quite acceptable.
Influence of ultrasound on the properties of chymosin and the ultrastructure of abomasum during chymosin extraction.

The effects of ultrasound treatment on the properties of chymosin and the ultrastructure of abomasum during chymosin extraction were investigated. Ultrasound treatment at 36 W/cm2 for 80 min did not decrease chymosin activity and its proteolytic activity. However, high intensity ultrasound (157 W/cm2) and the prolonged exposure to high intensity significantly decreased chymosin activity and its proteolytic activity. Ultrasound treatment changed amino acid composition of chymosin. There were significant changes in the mole percent of histidine, proline, tyrosine, methionine, valine, and lysine at the lower specific intensity. Ultrastructure of abomasal tissue was not affected by ultrasound treatment at specific intensity 36 W/cm2 for 80 min. However, some mitochondria cristae were damaged and secretory granules were more compact even though their numbers remained the same.
Length quantization of DNA partially expelled from heads of a bacteriophage T3 mutant.

DNA packaging of phages phi29, T3 and T7 sometimes produces incompletely packaged DNA with quantized lengths, based on gel electrophoretic band formation. We discover here a packaging ATPase-free, in vitro model for packaged DNA length quantization. We use directed evolution to isolate a five-site T3 point mutant that hyper-produces tail-free capsids with mature DNA (heads). Three tail gene mutations, but no head gene mutations, are present. A variable-length DNA segment leaks from some mutant heads, based on DNase I-protection assay and electron microscopy. The protected DNA segment has quantized lengths, based on restriction endonuclease analysis: six sharp bands of DNA missing 3.7–12.3% of the last end packaged. Native gel electrophoresis confirms quantized DNA expulsion and, after removal of external DNA, provides evidence that capsid radius is the quantization-ruler. Capsid-based DNA length quantization possibly evolved via selection for stalling that provides time for feedback control during DNA packaging and injection.
A fully coupled quadrature-based moment method for dilute to moderately dilute fluid–particle flows

Abstract A third-order quadrature-based moment method for simulating dilute and moderately dilute fluid–particle flows has been implemented with full coupling in a computational fluid dynamics code. The solution algorithm for the particle phase uses a kinetic-based finite-volume technique to solve the velocity moment equations derived from kinetic theory. The procedure to couple the particle-phase volume-fraction and momentum equations with the Eulerian solver for the fluid phase is explained in detail. As an example application, simulations of a particle-laden vertical channel flow at fluid-phase Reynolds number 1379 and particle Stokes numbers 0.061 and 0.61 were carried out. The fluid and particle velocities, particle-phase volume fraction and granular temperature were observed to reach a steady state in the case of Stokes number 0.061, while instabilities that led to the formation of structures and initiated the particle segregation process were observed in the case with the higher Stokes number. These results are validated against results from a classical two-fluid model derived from the kinetic theory of granular flows in the small Knudsen number limit, and Euler–Lagrange simulations of the same flow.
Synthesis, Structure, and Physical Properties of La3-xMxNi2O7-δ (M = Ca2+, Sr2+, Ba2+; 0 < x ≤ 0.075)

Abstract The synthesis, structure, and physical properties of La 3- x M x Ni 2 O 7-δ , with M = Ca 2+ , Sr 2+ , or Ba 2+ , and 0 x ≤ 0.075, were investigated. These compounds were prepared by a precursor method with tetramethyl ammonium hydroxide and were characterized by room temperature and high-temperature powder X-ray diffraction, TGA, electrical resistivity, and magnetic susceptibility measurements. The substituted compounds form with orthorhombic symmetry in space group Fmmm , similar to the as-prepared parent compound, La 3 Ni 2 O 6.92 . As the amount of divalent alkaline earth metal substitution increases, the c cell parameter does not significantly change for Ca and increases significantly for Sr and Ba substitution, while the a and b cell parameters remain nearly unchanged for all cases. The observed trend in the c parameter is due to the increasing Ni 3+ ion concentration for the case of Ca 2+ substitution, while for Sr 2+ and Ba 2+ substitutions the effective larger size of the divalent cations is dominant. Significant oxygen deficiencies are noted in all of the as-prepared samples. However, upon high-pressure oxygen annealing, stoichiometric oxygen contents can be achieved. The room temperature resistivity of the as-prepared substituted compounds decreases relative to La 3 Ni 2 O 6.92 , and at x = 0.075 a semiconductor to metal transition is observed for all M . The high-pressure oxygen annealed samples for all compositions show metallic behavior from room temperature down to 20 K. The magnetic susceptibility is nearly temperature independent in the temperature range 100-300 K, and paramagnetic behavior is observed below 100 K.
Further studies on electromyographic findings in generalized scleroderma.

The authors discuss the electromyographic findings in generalized scleroderma on the basis of 64 cases.
An Uncommon Blood Group Isoantibody (Anti-M) in Neoplastic Disease

THE first case in this series of anti-M sensitized patients was reported in 1958 because it presented a unique exception to the generalization that cold agglutinins are without significance in transfusion practice. The patient had received no M stimulus from either previous transfusion or pregnancy. We commented: “The possibility of a relation between the abnormal isoantibody and the patient's carcinoma of the cecum is being investigated”1.
Influence of a Health-Related Physical Fitness Model on Students' Physical Activity, Perceived Competence, and Enjoyment

This study was designed to explore the effects of a health-related physical fitness physical education model on students' physical activity, perceived competence, and enjoyment. 61 students (25 boys, 36 girls; M age = 12.6 yr., SD = 0.6) were assigned to two groups (health-related physical fitness physical education group, and traditional physical education group), and participated in one 50-min. weekly basketball class for 6 wk. Students' in-class physical activity was assessed using NL-1000 pedometers. The physical subscale of the Perceived Competence Scale for Children was employed to assess perceived competence, and children's enjoyment was measured using the Sport Enjoyment Scale. The findings suggest that students in the intervention group increased their perceived competence, enjoyment, and physical activity over a 6-wk. intervention, while the comparison group simply increased physical activity over time. Children in the intervention group had significantly greater enjoyment.
Exotic Earthworm Communities Within Upland Deciduous Forests of National Wildlife Refuges in the Upper Midwest

Abstract The invasion of exotic earthworms into forests of the Upper Midwest region of the United States is a considerable management issue due to the ability of earthworms to act as ecosystem engineers and modify existing ecosystems. Earthworm taxa differ in their biology and behavior, such that earthworm abundance and community composition can be related to the type and degree of alteration expected to occur. Many National Wildlife Refuges of the Upper Midwest have enabling legislation that identifies migratory birds as a specific management priority, and past studies have indicated that earthworm-modified forests provide lower quality habitat for migratory, ground-nesting birds. We quantified exotic earthworm community composition, abundance, and variability within and among upland deciduous forest stands at six of these refuges (Horicon, Ottawa, Rice Lake, Seney, Shiawassee, and Tamarac), providing a baseline for estimating the status of earthworm invasion. Analyses revealed a significant difference i...
Nonlinear optical properties of quantum-well structures and some of their applications

ABSTRACTMultiple quantum well structures of several materials such as GaAs/GaAlAs and InGaAs/InP have interesting nonlinear optical properties for devices. One example is the adjustment of absorption edge as well as the refractive index by control of the well width or application of electric field. The theoretical understandings of these properties in terms of the intrinsic material constants andexternally controlled parameters are to be discussed. We also review some recent applications of these materials in wave guides for directional couplers and switches.L INTRODUCTIONSemiconductor multiple quantum wells have an electro-optic effect at least one order of magnitude larger than the conventional semiconductors. The devices are not only fast but also compact, an important condition for monolithic integrated electro-optic devices. Wood's review article1 on thissubject has a detailed discussion. In Table 1 he shows why multiple quantum well (MQW) structure issuch a valuable part of the device. The most important factor for the intensity modulator is the on/off
In the era of multislice CT, do we still need leg ultrasonography to diagnose pulmonary embolism?

In the era of multislice CT, do we still need leg ultrasonography to diagnose pulmonary embolism?
Differential expression pattern of the antiapoptotic proteins, Bcl-2 and FLIP, in experimental arthritis.

Objective. To examine the relationship between apoptosis and the expression of antiapoptotic proteins in the pathogenesis of experimental inflammatory arthritis. Methods. Clinical and histologic assessment of adjuvant-induced arthritis (AIA) was performed over a 42-day period. The induction of apoptosis was measured by TUNEL analysis, and the antiapoptotic proteins, Bcl-2 and FLIP, were examined by immunohistochemistry with the use of monospecific antibodies. The percentage of Bcl-2- and FLIP-positive cells was correlated with histologic markers of AIA. Results. Arthritis developed by day 14 following adjuvant injection. Few TUNEL-positive cells were observed between days 0 and 21, indicating that apoptosis did not occur at these time points. An increase in the number of TUNEL-positive cells was observed at day 28, particularly outside sites of cartilage or bone erosion, which dramatically declined by day 35. Immunohistochemical analyses of Bcl-2 and FLIP revealed that the synovium was positive for Bcl-2 and FLIP on day 0. On day 14, Bcl-2 was present at the sites of early erosions and correlated with the erosion and inflammation scores. FLIP was also highly expressed at sites of erosion and was localized to the pannus starting on day 21. Although TUNEL positivity peaked at day 28, a time point in which Bcl-2 and FLIP were present, the areas that displayed intense positivity for expression of Bcl-2 and FLIP were TUNEL negative. In addition, the number of neutrophils in the synovial lining and pannus significantly decreased from day 28 to day 35, suggesting that the cells undergoing apoptosis were neutrophils. Furthermore, at day 42 when TUNEL-positive cells were absent, Bcl-2 expression was diminished, while FLIP remained highly expressed in the pannus. Conclusion. The overall percentage of TUNEL-positive cells in the ankle was <1% except on days 28 and 35 post-adjuvant injection, suggesting that in AIA, similar to rheumatoid arthritis, a lack of apoptosis may contribute to disease progression. Furthermore, Bcl-2 and FLIP are temporally and differentially expressed during the pathogenesis of AIA. Inhibition of these molecules may augment synovial apoptosis and ameliorate the disease.
Sperm binding, in vitro fertilization, and in vitro embryonic development of bovine oocytes fertilized with spermatozoa incubated with norepinephrine.

Abstract The final stages of sperm maturation, fertilization, and early embryonic development occur within the oviduct and are essential for successful reproduction in mammals. Norepinephrine was previously identified in native bovine oviductal fluid and its in vitro effects on bull sperm capacitation and the acrosome reaction have been determined. It was unknown how physiological concentrations of norepinephrine influence sperm binding, fertilization, and embryo development. Therefore, the objective of this study was to determine if pre-incubating bovine spermatozoa with physiological concentrations of norepinephrine prior to insemination of bovine oocytes would improve sperm–oocyte binding, fertilization, and embryonic development in vitro. Norepinephrine, in concentrations representing those measured in bovine oviductal fluid, was used to treat bovine spermatozoa prior to insemination. Spermatozoa incubated in norepinephrine were used to inseminate bovine oocytes matured in vitro, and oocytes were evaluated for sperm binding and fertilization. Additional experiments were conducted to evaluate how early in the co-incubation period oocytes were fertilized by spermatozoa pre-incubated with norepinephrine, and to test the developmental competence of those oocytes fertilized with norepinephrine-treated sperm. Sperm binding to the zona pellucida was reduced by pre-incubation with norepinephrine. Rates of fertilization and embryo development did not increase as a result of pre-incubating spermatozoa with norepinephrine, but as early as 4 h after insemination, spermatozoa treated with 20 ng/ml norepinephrine fertilized more oocytes than spermatozoa incubated in medium alone. Interestingly, this concentration of norepinephrine was found to capacitate spermatozoa in previous studies. These data suggest that oocytes fertilized by spermatozoa incubated in 20 ng/ml norepinephrine fertilize earlier in vitro than sperm pre-incubated in medium alone, and provide additional support for the role of norepinephrine in sperm capacitation and the acrosome reaction.
The process of crystal melting II. Melting kinetics of sodium disilicate

Abstract The kinetics of crystal melting for sodium disilicate have been determined over the temperature range 875–884°C. When compared with previous data on crystallization kinetics, melting is found to take place much more rapidly than crystallization. The reduced melting rate is found to be independent of superheat, and the interface morphology in melting is non-faceted. It is suggested that the crystal-liquid interface in melting is rough on an atomic scale.
FGF/EGF signaling regulates the renewal of early nephron progenitors during embryonic development

Recent studies indicate that nephron progenitor cells of the embryonic kidney are arranged in a series of compartments of an increasing state of differentiation. The earliest progenitor compartment, distinguished by expression of CITED1, possesses greater capacity for renewal and differentiation than later compartments. Signaling events governing progression of nephron progenitor cells through stages of increasing differentiation are poorly understood, and their elucidation will provide key insights into normal and dysregulated nephrogenesis, as well as into regenerative processes that follow kidney injury. In this study, we found that the mouse CITED1(+) progenitor compartment is maintained in response to receptor tyrosine kinase (RTK) ligands that activate both FGF and EGF receptors. This RTK signaling function is dependent on RAS and PI3K signaling but not ERK. In vivo, RAS inactivation by expression of sprouty 1 (Spry1) in CITED1(+) nephron progenitors results in loss of characteristic molecular marker expression and in increased death of progenitor cells. Lineage tracing shows that surviving Spry1-expressing progenitor cells are impaired in their subsequent epithelial differentiation, infrequently contributing to epithelial structures. These findings demonstrate that the survival and developmental potential of cells in the earliest embryonic nephron progenitor cell compartment are dependent on FGF/EGF signaling through RAS.
Ultrastructural studies of chronic pneumonia in guineapigs

Summary Pulmonary interstitial fibrosis commenced as focal proliferation of fibroblasts and accumulation of macrophages in interalveolar septa and was followed by deposition of excess collagen. Epithelium of airways and alveoli remained normal. Perivascular nodules of lymphoid tissue which developed in the lungs of many older animals had a high mitotic rate, but the lymphocytes were morphologically normal. Micro-organisms were not observed in the lungs of any animal. In a previous publication (Baskerville, Baskerville & Wood, 1982) we described histopathological and bacteriological studies of naturally-occurring chronic pneumonia in a colony of guineapigs. The lesions were of two main types, pulmonary interstitial fibrosis (PIF) and perivascular lymphoid hyperplasia (PVL). No correlation was found between the presence of Bordetella bronchiseptica or other bacteria and the development of the pulmonary lesions, and their aetiology remains unknown. A detailed electron microscopical study was therefore undertaken to determine the nature and pathogenesis of these chronic lesions and to search for evidence of other possible causative agents, in particular mycoplasmas and viruses.