cssi/SciSciGPT-SciSciNet huggingface dataset:
Viscosity and normal stresses in branched polydisperse polymers

The steady-flow behavior of five samples of branched poly(vinyl acetate) has been studied with the Weissenberg rheogoniometer. The branching densities and molecular weight distributions were known from an analysis of the polymerization kinetics. Measurements were made on concentrated diethyl phthalate solutions (0.170 and 0.225 g/ml) at temperatures of 30 and 70°C. The viscosities of all solutions at zero shear rate were less than of solutions of linear poly(vinyl acetate) with the same weight-average molecular weight. The amount of decrease was in excellent agreement with Bueche's theory of melt viscosity in branched systems. The viscosity versus shear rate curves were surprisingly independent of molecular weight distribution, the data from all samples being superimposable on the same master curve. Relaxation times derived independently from the viscosity behavior and the normal stress data were of similar magnitude and always close to the Rouse relaxation time of each solution.
The chemistry of nitroxyl (HNO) and implications in biology

Over the past century, HNO research has evolved from fundamental physical examinations to elucidation of interactions in atmospheric, industrial and bacterial processes. Most recently, the HNO literature has been primarily concerned with the pharmacological effects and potential physiological functions of HNO in mammalian systems. The chemistry of HNO is inordinately complicated for a triatomic molecule. Further, the rapid self-consumption of HNO through dehydrative dimerization impedes detection and necessitates in situ production. This review provides a detailed discussion of the most common donors of HNO and of the current understanding of the aqueous chemistry of HNO and the synthesis, consumption and reactivity of HNO in a cellular environment, as ascertained with these donors. Additionally, the consequences of the molecular interactions of HNO on physiology are described, and a comparison is made to NO in terms of cellular signaling and pharmacological potential.
Limitations on Carry Lookahead Networks

The fan-in and fan-out limitations imposed by specific gate circuits force corresponding limits-upon the sizes of carry lookahead circuits fabricated from those gates. The relationships between those limits are derived, providing simple formulae that can be used by designers seeking to fabricate fast combinational binary adders.
Verbal Communication as a Mediator of Expectancy Effects: Methodological Artifact?

Srrmmary.-No significant expectancy effects were observed on a photorating task when 7 Es participated in a study to evaluate verbally mediated effecu. Reasons for failure to confirm findings of Rosenthal and Fode were explored. Rosenchal (1964, 1966), in his reviews of the literature on the experimenter bias phenomenon, cites an experiment by Fode ( 1960; Rosenthal & Fode, 1963) investigating the relative significance of the auditory and visual communication modalities as mediators of E's ~tnintencional expeccancy influence on S's actual performance. Rosenthal interprets Fode's experiment as a demonstration that the auditory mode is the more significant channel for producing these expectancy effects, althougl.1 the visual mode greatly augments the effects. The present paper reports the first in a planned series of experiments related to verbal communication as a mediator of expectancy effects. In the present study, Es and Ss were limited to verbal interactions and tape recordings were made of each E's presentation of standardized instruccions to Ss. The plan was to scrutinize these tapes by spectographic and ocher techniques of acoustic analysis to identify the specific vocal characteristics associated with s~~ccessful communication of E's outcome expectancies. As an additional benefit, a rape library of Es with known communication value would be collected for further use in exploring subjecc variables. It was assumed (there was no reason to suspect otherwise) that expectancy effects would be obtained using this verbal inreraction procedure. METHOD Participants Seven male Es and 59 female Ss participated in this study, each E administering the experimental task individually to from 6 to 11 Ss. Es were graduate st~~dents at rhe University of Wisconsin; Ss were volunteers from the subjecc pool of the introductory psychology course and received "points" for their participa
Magnetotransport characterization of remotely-doped superlattices in wide parabolic GaAs/AlxGa1−xAs quantum wells

Abstract We have produced and characterized two quantum wells which are a superposition of a square superlattice with a wide parabolic well using the digital alloy method. With this technique it is possible to make doped superlattices with high mobility (μ = 37,000 and 100,000 cm2/Vsec). In the sample with larger superlattice bandwidth we used Fourier analysis of low field Shubnikov-de Haas oscillations to measure subband energy separations. We detected four occupied subbands indicating occupation of four superlattice periods. The measured subband spacings agree well with self-consistent calculations and are smaller than spacings in a parabolic well with no superlattice. In another well with smaller bandwidth, sheet density measurements indicate eight periods are occupied.
Proactive Policing Effects on Repeat and Near-Repeat Shootings in Houston

The spatial analysis of crime and community problems can inform police operations by revealing where resources can be most effectively deployed. Advances in understanding the spatial concentrations of crime show that some locations are repeatedly victimized and that some nearby locations are at an elevated risk for a subsequent crime during a relatively short period of time. These are known as repeat and near-repeat phenomena. Police may be able to have a strong preventive impact on crime if these risk patterns can be identified and disrupted. This analysis reports on whether a specialized, proactive patrol unit deployed to high-crime areas was effective in disrupting repeat and near-repeat patterns of shootings. Results suggest the proactive unit did not disrupt concentrations of shootings in a meaningful way. To improve effectiveness, police practitioners and researchers should seek to understand the factors driving these patterns and then design specific interventions to address them.
Measurement and quantum indeterminateness

Albert and Loewer[1] have recently clarified their earlier objection to the interactive interpretation presented in Healey[2]. They now charge that this interpretation fails to solve a problem of which the measurement problem is but a special case. The general problem is to reconcile quantum mechanics with theprima facie determinateness of such dynamical properties as the positions of macroscopic objects. In response I defend both the preeminent significance of determinate measurement outcomes and the claim that the models of Healey[3] go a long way toward securing their determinateness.
Ten years of the literature of online searching: An analysis of Online and Online Review

An analysis of data from the first decade of the publication of Online and Online Review revealed that while both cover the literature of online searching, they are very different. Editorial policies, subtitles, and editorial board memberships all indicate differing perspectives. Further, objective data, such as impact factors, immediacy indexes, and rankings within the category of information and library science, are statistically significantly different. Both the national and institutional affiliations of the authors publishing in the two journals also differed. And, an analysis of the titles showed each journal covering different topics within the field. © 1990 John Wiley & Sons, Inc.
Pitting of nickel during anodic galvanostatic charging in Na2SO4 solutions

Abstract The anodic galvanostatic charging technique has been used to study the pitting of nickel in acid and neutral Na 2 SO 4 solutions containing various concentrations of Cl − . Pit initiation is indicated by a change in potential in the cathodic direction, this potential being substantially higher than that required to sustain pitting. The steady-state pitting potentials are in the passive, rather than the active, potential region, a result which can be explained by the highly localized nature of the pitting process. Increasing the [Cl − ] lowers the potential for pit initiation as well as the steady-state pitting potentials. The influence of anodic charging rate ( i g a ) on pit initiation depends on the [Cl − ] in solution; at high [Cl − ] the charging curves are similar except for the potential shift with i g a , while at low [Cl − ] pit initiation is more difficult with higher values of i g a . The minimum [Cl − ] required for pit initiation increases with decreasing solution temperature, ie with decreasing solution aggressiveness. The potential for pit initiation tends to be higher at lower solution temperatures and/or at higher pH's [Cl − ], anodic charging rate, solution temperature and pH influence pit initiation by affecting the efficiency of oxide repair at local breakdown sites in the passive oxide film.
156 GROWTH RETARDATION IN CHILDREN WITH CONGENITAL ADRENAL HYPERPLASIA (CAH) WITH PREDNISONE SUBSTITUTION IS NOT GROWTH HORMONE (GH) AND IGF 1 DEPENDENT

Prednisone inhibits growth more potently than hydrocortisone. Supression of GH secretion has been discussed as one possible mechanism. In a retrospective study GH, IGF 1 and procollagen type III propeptide (P-III-NP and FAB), which correlates to growth velocity, were determined longitudinally in sera of 9 children with CAH (age: 6 to 11 ys) during an intermittent period of prednisone substitution (4mg/m2bid) for 6 to 24 months and a subsequent period of hydrocortisone substitution (20mg/m2/tid) for 24 months. Prednisone treatment led to a deceleration of mean growth velocity (0.5 to −4.7 SDS for bone age) without delay of scetetal maturation resulting in a mean decrease of final height prediction of 6 cm. While IGF 1 (4.7 ± 2.1 vs. 4.3 ± 1.2 U/ml, mean ± 1 SD) and GH (5.6 ± 6.1 vs. 4.0 ± 6.9 ng/ml) did not differ during both periods, P-III-NP (13.1 ± 3.5 vs. 28.6 ± 7.4 ng/ml) and FAB levels (63 ± 18 vs. 128 ± 29 ng/ml) were reduced (p<0.001) during prednisone substitution. During both regimens in 2 of these children the nocturnal GH secretion (above 2500 ng·min·ml−1), stimulated GH levels after insulin-induced hypoglycaemla (above 15 ng/ml) and after GRF administration (above 26 ng/ml) were normal. Our observation gives strong evidence that the impairment of growth by hydocortisone-equivalent doses of prednisone is not mediated by changes of GH and IGF1 secretion but rather by a peripheral inhibition of GH and IGF1 effects at the tissue level.
Mechanism of the Blood Pressure Response to Anoxia Durin Hypolycemia

ConclusionThe large blood pressure rise due to anoxia, observed during hypoglycemia, may be caused by a severe depression by the combined effect of narcosis and hypoglycemia of those reactions which counteract a marked rise in blood pressure, the reactions causing this rise in blood pressure being less severely depressed.
Raising the bar [standards]

We wish to briefly describe what standards are and how they benefit society, how standards should relate to the goals of the enterprise, and why the IEEE is best suited to developing standards.
Search for a light neutral boson associated with beta decay

Abstract A gamma-gamma coincidence measurement was performed in order to search for a neutral scalar particle associated with beta decay with a mass near 17 keV. The measurement used a 35 S source and two LEPS-type Ge detectors. A coincidence signal above the background generated by random bremsstrahlung coincidences would be a signature of the two-photon decay of a light neutral scalar particle. No evidence was found for such a particle with a mass near 17 keV with a lifetime shorter than 1 nanosecond.
Matrix Transformations and Disk of Convergence in Interpolation Processes

Let 𝐴 𝜌 denote the set of functions analytic in | 𝑧 | 𝜌 but not on | 𝑧 | = 𝜌 ( 1 𝜌 ∞ ) . Walsh proved that the difference of the Lagrange polynomial interpolant of 𝑓 ( 𝑧 ) ∈ 𝐴 𝜌 and the partial sum of the Taylor polynomial of 𝑓 converges to zero on a larger set than the domain of definition of 𝑓 . In 1980, Cavaretta et al. have studied the extension of Lagrange interpolation, Hermite interpolation, and Hermite-Birkhoff interpolation processes in a similar manner. In this paper, we apply a certain matrix transformation on the sequences of operators given in the above-mentioned interpolation processes to prove the convergence in larger disks.
Processing parameters for consolidating PEEK/carbon fiber (APC-2) composites

This consolidation of unidirectional APC-2 was studied experimentally to determine the effects of processing parameters (pressure, temperature, and number of layers) on resin flow as measured by the Kozeny constant and the bulk modulus. The Kozeny constant obtained was between 0.0205 and 0.107. It was found to depend on the consolidation pressure, temperature, number of layers, and their interactions at a 99% confidence level. The value of the bulk modulus was found to be between 1.21 MPa (175 psi) and 8.58 MPa (1244 psi). It also was found to depend on the temperature, pressure, number of plies, and their interactions at a 99% confidence level. These results show the critical effects of fiber orientation on resin flow during processing.
Theoretical foundations for collaborative commerce research and practice

Going beyond the trading view of electronic commerce, collabo- rative commerce (c-commerce) is concerned with electronic means to enable and facilitate collaborative relationships involving knowledge flows among distributed participants engaged in various joint activities such as those that make up the value chain. C-commerce experience among practitioners is in an emergent stage and c-commerce research has yet to be well-developed. There are many open questions about c-commerce practices and fundamen- tals. Drawing on a wide range of literature, this paper introduces a theoretical foundation for investigating the nature and outcomes of c-commerce. This foundation takes the form of a relatively comprehensive theoretical framework that identifies salient factors and relationships for practitioners to consider in launching a c-commerce initiative or for researchers to consider in designing c-commerce research studies.
Topics in landing gear dynamics research at NASA Langley

Four topics in landing gear dynamics are discussed. Three of these topics are subjects of recent research: tilt steering phenomenon, water spray ingestion on flooded runways, and actively controlled landing gear. The fourth topic is a description of a major facility recently enhanced in capability.
An axiomatic model of rate-independent plasticity

Abstract A model of rate-independent plasticity is proposed, in which neither loading surfaces nor yield surfaces are assumed to exist. It is shown that the existence of loading surfaces follows mathematically from a loading/unloading postulate and the continuity of material behavior and that the second law of thermodynamics can furnish a yield criterion which may be identified with the Frank-Read source activation criterion.
Understanding Algorithm Aversion: Forecasters Erroneously Avoid Algorithms After Seeing them Err

When faced with the choice between a human judge and a (superior) statistical algorithm, forecasters often choose the human judge, but the basis for this choice is unknown. We hypothesized that for...
Charged particle induced ionization rates in planetary atmospheres

Abstract We have derived a non-relativistic formula for calculating the rate at which charged particles from a solar flare produce ion pairs in planetary atmospheres. Our method is simpler to use than the elaborate expression developed by Velinov.
GaAs metal-semiconductor-metal photodector mixers for microwave single-sideband modulation

A new optical technique for microwave single sideband modulation is reported. It uses metal-semiconductor-metal Schottky photodiodes formed in a GaAs/Al 0.3 Ga 0.7 As materials system to detect microwave in-phase and quadrature signals on optical carriers. Modulation of the photodetector bias voltages results in a single sideband modulation of the microwave signal, rf and undesired-sideband suppression of 36 dB and 27 dB, respectively, were achieved. The optical wavelength was 850 nm, and the bandwidth of the photodetectors is greater than or equal to 29 GHz.
Variation in pulmonary vein size during the cardiac cycle: Implications for non–electrocardiogram-gated imaging

Background Understanding pulmonary vein (PV) anatomy is important for the planning and execution of PV isolation for the treatment of atrial fibrillation, screening for PV stenosis after the procedure, and investigating the pathophysiology of atrial fibrillation. We hypothesized that significant changes in PV size occur during the cardiac cycle and sought to identify the relationship of data obtained with conventional non–electrocardiogram (ECG)–gated methods compared with ECG-gated measures of PV size using cardiovascular magnetic resonance. Methods A consecutive series of 14 patients in sinus rhythm were evaluated with non–ECG-gated contrast-enhanced magnetic resonance angiography and ECG-gated cine cardiovascular magnetic resonance of the PV. Pulmonary vein diameter, perimeter, and cross-sectional area (CSA) were measured using both methods. Results Maximum diameter, perimeter, and CSA occurred simultaneously in all PV. The timing of the maximum size varied but generally occurred in ventricular diastole (101 ± 112 milliseconds after mitral valve opening). The timing of minimum PV size also varied but generally occurred in ventricular systole (212 ± 90 milliseconds before mitral valve opening). The difference between the maximum and minimum PV size was 15% ± 8% for diameter, 15% ± 7% for perimeter, and 27% ± 12% for CSA ( P R 2 > 0.48, P P Conclusions All measures of PV size vary significantly during the cardiac cycle. Contrast-enhanced magnetic resonance angiography PV measurements correlate best with maximum PV size.
Compound Poisson distributions : properties and estimation

Multivariate compound Poisson distribution is obtained by m p-independent Poisson distributions with a mixing distribution. marginal, conditional probability mass function and moments of comp Poisson distribution when the mixing parameter has a gamma distribu are obtained. The parameters of the mixed distribution are then estirr under a normalized squared error loss. The improved estimators obtained over the unbiased estimators for ' p> = 2, by solving ce difference inequality. Also robustness of the Clevenson-Zidek type estin is shown when the p-distributions are dependent through the m process. Risk simulations studies are obtained to show the amoui improvements.
Intestinal fatty acid binding protein: the folding mechanism as determined by NMR studies.

The intestinal fatty acid binding protein is composed of two β-sheets surrounding a large interior cavity. There is a small helical domain associated with the portal for entry of the ligand into the cavity. Denaturation of the protein has been monitored in a residue-specific manner by collecting a series of two-dimensional 1H−15N heteronuclear single-quantum coherence (HSQC) NMR spectra from 0 to 6.5 M urea under equilibrium conditions. In addition, rates for hydrogen−deuterium exchange have been measured as a function of denaturant concentration. Residual, native-like structure persists around hydrophobic clusters at very high urea concentrations. This residual structure (reflecting only about 2−7% persistence of native-like structure) involves the turns between β-strands and between the two short helices. If this persistence is assumed to reflect transient native-like structure in these regions of the polypeptide chain, these sites may serve as nucleation sites for folding. The data obtained at differen...
The contribution of prothrombotic states to cancer-related stroke

Abstract Risk factors for cancer-related ischemic stroke are difficult to discern from the traditional risk factors for atheroembolic disorders. Certain hematologic and oncologic malignancies predispose to ischemic stroke. However, contributing pathophysiologic mechanisms are complex, and they cannot often be directly identified as specific causes of a thrombotic event. Generally speaking, interactions between the cellular phase and the plasma phase of coagulation are heightened in malignancy patients. Tissue factor and other procoagulant initiators of thrombosis predominate in certain solid tumor subtypes. Specific malignant hematologic disorders, such as polycythemia vera, essential thrombocythemia, Waldenstrom macroglobulinemia, and subtypes of acute leukemia, are perhaps best characterized as causes of a hypercoagulable state. Solid tumor treatments entail effects of radiation and specific chemotherapy agents that may pose a prothrombotic risk. This review focuses on the pathophysiology of ischemic stroke in malignancy with emphasis on underlying prothrombotic states and the management of these patients.
Use of Mohr's circle to transform stretch components

Following previous work by Meyer it is shown how a general triangle in a homogeneous finite strain field can be transformed using Mohr's circle. Then as an application a general expression is given to determine principal components from rosettes in finite strain fields. The results obtained will be useful in the analysis of grid data.
Novel anxiolytics discriminate between postsynaptic serotonin receptors mediating different physiological responses on single neurons of the rat hippocampus

The effects of buspirone on hippocampal pyramidal cells of the CA1 region were examined by means of intracellular recordings in in vitro hippocampal brain slices. Bath administration of buspirone elicited a long lasting hyperpolarization which was mediated by an increase in potassium conductance and resembled the hyperpolarizing component of the response to 5-HT (5-hydroxytryptamine). Buspirone, however, failed to mimic the depolarizing action of 5-HT or to reduce the calcium-activated afterhyperpolarization. Quantitative comparisons of the hyperpolarizing responses of 5-HT and buspirone revealed that the maximal hyperpolarization induced by buspirone was significantly smaller than that induced by 5-HT. Since the buspirone induced hyperpolarization was also accompanied by a surmountable antagonism of 5-HT responses, these results indicate that buspirone behaves as a partial agonist at a subpopulation of 5-HT receptors in the CA1 region of the hippocampus. Administration of the buspirone congeners gepirone and isapirone also elicited a hyperpolarization and reduced 5-HT responses, although they lack anti-dopaminergic activity, indicating that the effects observed with buspirone are unlikely to be mediated through dopamine receptors. These results indicated that novel anxiolytics can discriminate between functional 5-HT receptors. In conjunction with previous biochemical and electrophysiological studies, the present results suggest that their administration might alter the balance of serotonergic actions on postsynaptic neurons.
New Material of Dipodid Rodents (Dipodidae, Rodentia) from the Early Miocene of Gashunyinadege, Nei Mongol, China

ABSTRACT Dipodid rodent fossils from Gashunyinadege at ∼17 Ma, one of the oldest Neogene localities in central Nei Mongol, China, include six genera (Heterosminthus, Plesiosminthus, Litodonomys, Sinodonomys, gen. nov., Omoiosicista, gen. nov., and Sicista) and nine species, including four new species (P. vegrandis, sp. nov., L. minimus, sp. nov., S. simplex, sp. nov., and O. fui, sp. nov.). The high diversity and abundance of dipodid rodents in Gashunyinadege indicate the evolution of basal dipodids was centered in Nei Mongol. Omoiosicista is described on the basis of eight isolated teeth and characterized by possessing one autapomorphy. This new taxon shares seven synapomorphies with Sicista, suggesting Sicista is the closest relative.
Wald-like formula for energy

We present a simple ``Wald-like'' formula for gravitational energy about a constant-curvature background spacetime. The formula is derived following the Abbott-Deser-Tekin approach for the definition of conserved asymptotic charges in higher-derivative gravity.
Effect of halogen light stimulation on nonstress testing.

Abstract Objective This study was undertaken to determine whether external stimulation using a halogen light source influences fetal heart rate (FHR) responsiveness and nonstress test results. Study design A total of 107 patients at 32 to 42 weeks' gestation undergoing a nonstress test were randomly assigned to have either transabdominal light stimulation or no light stimulation. The light (Vector Compact Sport Spot, Ft Lauderdale, Fla) was turned on for 10 seconds. If no qualifying FHR acceleration was observed, then the stimulus was repeated at 10-minute intervals for a maximum of 3 times. The investigators were blinded as to light stimulation for FHR interpretation. Results Reactive results were present in 52 cases in each group. Light stimulation led to a significantly shorter time ( P Conclusion The earlier onset of FHR accelerations after halogen light stimulation prompted a more rapid reactive nonstress test result.
(-)-Propranolol blocks the inhibition of serotonergic dorsal raphe cell firing by 5-HT1A selective agonists.

Abstract The ability of the β-adrenoceptor antagonist propranolol to block the effects of serotonin (5-HT) and 5-HT 1A -selective agonists on the spontaneous firing of serotonergic dorsal raphe neurons was assessed. During microiontophoretic application, (-)- but not (+)-propranolol rapidly and reversibly blocked the suppressant effects of the 5-HT 1A -selective agonists ipsapirone (TVX Q 7821) and 8-hydroxy-2-(di-n-propylamino)tetralin (8-OH-DPAT). However, (-)-propranolol was a relatively weak antagonist of 5-HT itself, suggesting that the endogenous neurotransmitter may have actions on dorsal raphe neurons in addition to those mediated by 5-HT 1A receptors.
Absolute molecular weight of polyaniline.

The absolute molecular weight of polyaniline in the pernigraniline, emeraldine, and leucoemeraldine oxidation states has been measured by light scattering and the exact number of aniline repeat units determined for the first time. Using potential-time profiling to monitor the chemical oxidative polymerization of aniline using ammonium peroxydisulfate oxidant, all three oxidation states of polyaniline can be synthesized in one step and the evolution of polymer molecular weight monitored. The pernigraniline intermediate formed during the chemical oxidative polymerization of aniline increases by 17−20% when it is converted to emeraldine, which is consistent with a two-step polymerization mechanism. These findings establish a solid experimental framework to chemically synthesize block copolymers of polyaniline by using different monomers to intercept the reaction at the pernigraniline oxidation state.
Tomographic Fluorescence Lifetime Imaging

We present theory and methods for in vivo diffuse time domain fluorescence lifetime tomography. As examples, we will discuss in vivo lifetime imaging of both targeted and activatable probes in mouse models of cardiac disease and cancer.
Ancient Chinese mathematics: the (Jiu Zhang Suan Shu) vs Euclid’s Elements. Aspects of proof and the linguistic limits of knowledge

Abstract The following is a preliminary and relatively brief, exploratory discussion of the nature of early Chinese mathematics, particularly geometry, considered largely in terms of one specific example: the Download : Download full-size image (Gou-Gu) Theorem. In addition to drawing some fundamental comparisons with Western traditions, particularly with Greek mathematics, some general observations are also made concerning the character and development of early Chinese mathematical thought. Above all, why did Chinese mathematics develop as it did, as far as it did, but never in the abstract, axiomatic way that it did in Greece? Many scholars have suggested that answers to these kinds of questions are to be found in social and cultural factors in China. Some favor the sociological approach, emphasizing for example that Chinese mathematicians were by nature primarily concerned with practical problems and their solutions, and, therefore, had no interest in developing a highly theoretical mathematics. Others have stressed philosophical factors, taking another widely-held view that Confucianism placed no value on theoretical knowledge, which, in turn, worked against the development of abstract mathematics of the Greek sort. While both of these views contain elements of truth, and certainly play a role in understanding why the Chinese did not develop a more abstract, deductive sort of mathematics along Greek lines, a different approach is offered here. To the extent that knowledge is transmitted and recorded in language, oral and written, logical and linguistic factors cannot help but have played a part in accounting for how the Chinese were able to conceptualize—and think about—mathematics.
Villous adenoma of the colon and rectum.

One hundred and four cases of villous tumors during a 19-year period are reported, including 38 cases of villous adenoma and 40 cases of carcinoma arising in villous adenoma. These tumors are found in the rectum and rectosigmoid of patients who are mostly 50 years old or older. The majority of these tumors are malignant and the accuracy of diagnosis by biopsy is rather low. Villous tumors of the colon and rectum should be treated as cancerous growths, and radical resection is the preferred treatment.
An efficient and portable strings processor

In this paper the author discusses a string processing system designed to alleviate education and implementation problems normally associated with such systems. It is written as a set of FORTRAN subroutines using SAC-1 [1]. Hence, this system can be implemented almost anywhere, is easy to learn, and can be used in computer science classes with limited prerequisites.
Evaluating the clinical significance of a group approach for improving the social skills of children

To evaluate the effectiveness of a social skills proram for improving the social interactions and peer relationships of fifth grade children, a clinical analysis was conducted and compared to the statistical analysis. Social validation was used to assess clinical outcomes. Results showed that the treatment group (n = 20) made significant clinical gains on sociometric ratings and the roleplay tests. Low status children (n = 5) made significant gains on the roleplay tests and two of these children made significant gains on the sociometric measures.
The competitive inhibition of yeast alcohol dehydrogenase by 2,2,2‐trifluoroethanol

An experiment for undergraduate biochemistry laboratory classes demonstrating the competitive inhibition of yeast alcohol dehydrogenase by 2,2,2-trifluoroethanol is described. The experiment uses a convenient, rapid spectrophotometric assay and can be accomplished in one laboratory period. Students can measure the Michaelis-Menten constant for ethanol and determine the inhibition constant for 2,2,2-trifluoroethanol.
Leaf litter and understory canopy shade limit the establishment, growth and reproduction of Microstegium vimineum

The invasive grass Microstegium vimineum is widely distributed in closed-canopy forests, but often is patchily distributed under uniform canopy conditions. We hypothesized that the occurrence of patches of invasion may be related to two interacting factors, the presence of dense understory shrub layers and the presence of thick litter layers on the forest floor. Seeds of M. vimineum were sown in plots located under or distant from Lindera benzoin (spicebush) shrubs, and with or without litter manipulations (none, half of natural amount, naturally occurring amount, double the natural amount) in a mature forest in central New Jersey, USA. Populations were monitored for germination and survivorship, as well as growth and fecundity of surviving plants. Neither shrub-associated shade nor litter depth affected seed germination, but both factors affected survivorship, growth and reproduction. The presence of shade from the shrubs reduced survivorship and seed set. Seeds germinating on top of the litter layer also experience higher mortality than seeds germinating under litter and in contact with soil. These results suggest that the interacting effects of shade from understory strata and deep litter layers may limit the spread of M. vimineum. The loss of shrub layers due to intense deer browse and other factors may thus accelerate the spread of this highly invasive species.
Kinetic And Spectroscopic Probes To Evaluate The Dimensionality Of Triplet Exciton Migration In Polymeric Systems

The rate of decay of triplet excitons following a photoexcitation pulse has been determined for poly(2-vinylnaphthalene) in a variety of solvents at ambient temperature and at 77 K. A three dimensional model for exciton diffusion fits the data at ambient temperature but at 77 K the data are not well represented by a single integral dimensionality.
Heats of formation of HCCl3, HCCl2Br, HCClBr2, HCBr3, and their fragment ions studied by threshold photoelectron photoion coincidence.

The dissociative photoionization onsets for Cl and Br loss reactions were measured for HCCl3, HCCl2Br, HCClBr2, and HCBr3 by threshold photoelectron photoion coincidence (TPEPICO) in order to establish the heats of formation of the mixed halides as well as the following fragment ions: HCCl2+, HCClBr+, HCBr2+. The first zero Kelvin onsets were measured with a precision of 10 meV. The second onsets, which are in competition with the lower energy onsets, were established with a precision of 60 meV. Because both the chloroform and bromoform have relatively well established heats of formation, these measurements provide a route for establishing the heats of formation of the mixed halomethanes within uncertainties of less than 5 kJ mol−1.
Biologically-based modeling insights in inhaled vapor absorption and dosimetry

The lung is a route of entry and also a target site for inhaled vapors, therefore, knowledge of the total absorbed dose and/or the dose absorbed in each airway during inhalation exposure is essential. Vapor absorption characteristics result primarily from the fact that vapors demonstrate equilibrium/saturation behavior in fluids. Thus, during inhalation exposures blood and airway tissue vapor concentrations increase to a steady state value and increase no further no matter how long the exposure. High tissue concentrations can be obtained with highly soluble vapors, thus solubility, as measured by blood:air partition coefficient, is a fundamentally important physical/chemical characteristic of vapors. While it is classically thought that vapor absorption occurs only in the alveoli it is now understood that this is not the case. Soluble vapors can be efficiently absorbed in the airways themselves and do not necessarily penetrate to the alveolar level. Such vapors are more likely to injure the proximal than distal airways because that is the site of the greatest delivered dose. There are substantial species differences in airway vapor absorption between laboratory animals and humans making interpretation of laboratory animal inhalation toxicity data difficult. Airway absorption is dependent on vapor solubility and is enhanced by local metabolism and/or direct reaction within airway tissues. Modern simulation models that incorporate terms for solubility, metabolism, and reaction rate accurately predict vapor absorption patterns in both animals and humans and have become essential tools for understanding the pharmacology and toxicology of airborne vapors.
Photochemistry and Pinhole Photography: An Interdisciplinary Experiment

This interdisciplinary activity combines chemistry and art through the construction and use of a pinhole camera. We focused on the chemistry of the black and white photographic process as the science component of this activity. The reactions involved are good examples o photochemistry and multiphase chemical reactions, since the light sensitive materials (silver halides) are in the form of a gelatin emulsion of microscopic crystals.
Level of electrostatic excitation associated with relativistic beam-plasma system and pulsar radiation

A class of pulsar models which provide a stationary beam-plasma system as the source of radiation is considered. Since the beam-plasma system is stable near the pulsar where the coherent curvature radiation damps the longitudinal mode, we consider the beam-plasma system away from the star so that the effects of curvature radiation may be neglected. We find that the total wave energy density may attain a significant fraction of the beam energy density provided that the beam and plasma carry away a comparable amount of energy from the star. It should be noted that the attained high wave energy density is peculiar to a relativistic beam-plasma interaction.
An effective numerical method for controlled routing in large trunk line networks

Abstract The paper discusses a powerful approach to the routing problem in large networks of the trunk line type. The approximations are based on heavy traffic limit theorems. The sequence of suitably normalized available circuits converges to a reflected diffusion process as the size of the network grows, under reasonable conditions. This limit model contains the basic features of the original network. The optimal ergodic cost problem for a three (link) dimensional system is solved numerically via the Markov chain approximation method to get the optimal controls. These can be approximated in such a way that they can be applied to a network of arbitrary size, using only “local” information. The resulting policies are compared in simulations (on systems with hundreds of links) to other current approaches, and found to be quite competitive with other schemes of current interest and have many advantages.
Bilateral hippocampal atrophy in medial temporal lobe epilepsy

Summary: Quantitative evidence of hippocampal atrophy has been correlated with site of seizure onset, hippocampal neuronal loss, and seizure relief after resection. Most studies have quantified hippocampal atrophy using ratios or differences between right and left hippocampal values. However, bilateral hippocampal atrophy may remain undetected by these techniques. To assess the frequency and implications of bilateral hippocampal atrophy, we studied absolute hippocampal volumes in 53 temporal lobectomy patients who had undergone intracranial electroencephalogram recordings preoperatively. Coronal images were constructed perpendicular to the longitudinal axis of the hippocampus. Atrophy was defined as >2 SD below control values in the volume of the posterior. 5 cm of the hippocampus. Five of 53 patients (9%)had bilateral hippocampal atrophy; four of these cases were undetected by ratios. Surgery was performed on the side of ictal onset in all five patients; four have been seizure-free for >2 years. These results suggest that (a) mesial temporal sclerosis can be present bilaterally and may go undetected by hippocampal ratio or difference measures; (b) ab-solute hippocampal volume values as well as ratios are needed to detect all patients with bilateral hippocampal atrophy; and (c) temporal lobectomy is not contraindicated in patients with bilateral hippocampal atrophy, but success depends on electroencephalographic documentation of the side of predominant ictal onset.
In-plane vibrations of frames carrying concentrated masses

This paper deals with the determination of the fundamental frequency of vibration (antisymmetric mode) of a frame elastically restrained against translation and rotation at the ends, carrying concentrated masses. It is assumed that the structural configuration under study is symmetrical. Classical beam theory is employed and the frequency equation is generated by means of the Rayleigh-Ritz method and simple polynomial co-ordinate functions in order to represent the displacement field. An unknown parameter γ is included in the polynomials and this allows for optimization of the frequency coefficient by minimizing it with respect to γ.
Asymmetric ligand binding by haemoglobin.

The asymmetry observed in the titration curve of haemoglobin with oxygen is possible only if the α-α and β-β subunit interactions change by different amounts on oxygenation. This necessary difference justifies the α2β2 structure on functional grounds and its magnitude shows that haemoglobin function results from reversible oxygen binding to the β subunit.
Local Public Health System Performance and Community Health Outcomes

Background Public health systems are charged with protecting the health and well-being of the communities they serve. Higher-performing public health systems should be associated with improved community health status. Currently, little research examines the impact of variations in public health system performance on community health outcomes. Purpose The current study seeks to provide local public health system partners with evidence regarding the impact of their efforts. It does so through examining the relationship between variations in local public health system performance in providing the core functions of public health (assessment, assurance, and policy development) and community health outcomes. Methods Measures of community health status (dependent variables) and community demographic characteristics, collected from 1994 to 2003, were merged with measures of public health system performance collected from 2002 to 2007 (independent variables). For each dependent variable, Pearson correlations were calculated with all of the independent variables. Multivariate linear regression models were developed for each health outcome. Analysis was completed in 2010. Results Bivariate analysis found nine associations between local public health system performance and health outcomes. Linear regression models found associations between performance and three of the six outcomes measured. The outcomes associated with performance are those that would seem to be most sensitive to variations in practice. Poverty is significantly associated with all the health outcomes measured. Conclusions These associations between performance and health outcomes suggest that improving performance of the core functions of public health may improve health.
Fatty Acids, Insulin Resistance, and Protein Metabolism

Accretion and maintenance of lean body mass, because of its fundamental role in health and disease, continues to be an area of intense investigation. By using sophisticated tracer isotopic methods, organ balance techniques, and molecular analysis of tissue samples in humans and animal models, a detailed analysis of the signaling pathway and metabolic fluxes has been possible. Despite these, understanding the regulatory mechanism of nitrogen/protein accretion and maintenance of lean body mass in vivo continues to be challenging. This is particularly difficult because of the adaptation of metabolism to various modifying influences, and because of the multiple levels of regulation in vivo. Yet, by careful studies, a number of investigators have systematically examined the influence of diverse modifiers on the physiology of protein synthesis and breakdown in humans in vivo.
Effect of mutS and recD mutations on Salmonella virulence.

Hybrid derivatives of closely related bacteria may be used to dissect strain-specific functions that contribute to virulence within a host. However, mismatches between DNA sequences are a potent barrier to recombination. Recipients with mutS and recD mutations overcome this barrier, allowing construction of genetic hybrids. To determine whether Salmonella hybrids constructed in a mutS recD host can be used to study virulence, we assayed the effect of mutS and recD mutations on the virulence of Salmonella typhimurium 14028s in mice. Mutants defective in either mutS or recD do not affect the time course or the 50% lethal dose (LD50 )o f the infection. In contrast, the inactivation of both mutS and recD results in a synthetic phenotype which substantially increases the time required to cause a lethal infection without changing the LD50. This phenotype results from an inability of mutS recD double mutants to rapidly adapt to purine-limiting conditions present within macrophages. Although the disease progression is slower, S. typhimurium mutS recD mutants retain the ability to cause lethal infections, and, thus, hybrids constructed in mutS recD hosts may permit the analysis of virulence factors in a surrogate animal model. Salmonella serovars are closely related at the DNA level, and yet show substantial variations in the hosts they are able to infect and the types of diseases they elicit within each host. Certain strains of Salmonella typhimurium have been extensively studied, providing well-defined genetic and physical maps, a wide collection of mutant strains and selectable genetic markers, efficient mechanisms for gene transfer, and an excellent animal model for virulence (14, 23, 24). In contrast, other Salmonella serovars are less amenable to experimental analysis. For example, Salmonella typhi causes typhoid fever in humans but does not infect other animals. The lack of a simple in vivo assay for virulence has hampered the genetic analysis of S. typhi. Instead, most research has focused on the virulence of
Measurement of Polarization Statistics of Signals Received Over a Short Range HF Path

A study was performed to measure variations in the polarization characteristics of an HF signal received over a short range ionospheric path. This paper describes a limited number of experiments using signals from Station WWV to determine the statistical nature of the polarization ellipse at the receiving site, Hathaway Hill, near Rochester, N. Y. The approach employed was to regard the elliptically polarized wave as the resultant of two linearly polarized waves of the same frequency and to measure the amplitude and phase of these two components by employing orthogonally oriented receiving dipoles and associated devices to provide continuous recordings of the variables. Three types of data were recorded during a one week field test period, and samples of each type were reduced and analyzed. The data compiled showed that the received signal exhibits Rayleigh fading characteristics with a mean fading rate of approximately 0.15 fades per second. The envelopes of the received components exhibit a high correlation in the morning hours, considerably less correlation in the afternoon, and a high correlation in the evening characterized by a substantial offset in time between the fading of the two components which is often periodic. The envelope of the cross correlation function indicates that the conditions causing the disturbance are changing slowly on a minute-to-minute basis, although complete polarization rotation appears to take about 5 to 10 seconds and is characterized by both phase and amplitude changes of the component waves. It appears that the milder perturbations of relative phase are confined within limits of approximately \pm90\deg , and severe perturbations are characterized by a rapid monotonic change in the relative phase of the components of 2π.
Profit‐Maximizing Stocking Rates for Channel Catfish in Cages

A production function for catfish in cages was estmated by combining data from a survey of producers in Alabama with data from experimental studies in Texas, South Carolina, and Alabama. Explanatory variables in the quadratic model included cage stocking density, fingerling size, length of growing season, feed conversion rate, squared and cross-product terms, and dummy variables for data sources. Model R2 was 87%. Profit-maximizing stocking densities were calculated for varying levels of growing season duration, fingerling size, fingerling price and market price. Optimal stocking density was shown to be most sensitive to length of growing season.