Showing papers by "University at Buffalo published in 1978"

Assessment of a dental anxiety scale

Abstract: The Corah dental anxiety scale is shown to be a reliable tool for use in dental offices or research projects for measuring anxiety of dental procedures. Old and new data were considered in an evaluation of the Corah Dental Anxiety Scale. The data indicate that the scale can be used in the dental office or in research projects and is a reliable, valid, and useful measure of anxiety of dental treatment.

Assessing personal, role, and organizational predictors of managerial commitment.

Abstract: Using a role and exchange theory framework, this study examines the commitment to their organization and to the federal service of 634 managers in 71 federal government organizations. Results indicate that certain role factors such as tenure and work overload and personal factors such as attitude toward change and job involvement are strong influences on commitment. Implications of the findings and the need for further theoretical and methodological refinements are discussed.

Diet in the Epidemiology of Cancer of the Colon and Rectum

Abstract: We examined the diets as reported in interviews of 256 white male patients with cancer of the colon and of 330 white male patients with cancer of the rectum. Controls were 783 patients with nonneoplastic, nondigestive system diseases distributed by age similarly to the colon cancer patients and 628 patients with nonneoplastic, nondigestive diseases distributed by age like those with cancer of the rectum. We found no increase in risk for cancer of the colon or rectum regardless of the amounts of beef or other meats ingested. However, we found an increase in risk of colon cancer with decreases in the frequency with which vegetables were eaten. A study of 214 females with cancer of the colon and 182 females with cancer of the rectum yielded similar results. The decrease in risk we found associated with frequent ingestion of vegetables, and especially cabbage, Brussels sprouts, and broccoli, is consistent with the decreased numbers of tumors observed in animals challenged with carcinogens and fed compounds found in these same vegetables.

Specificity of salivary-bacterial interactions: role of terminal sialic acid residues in the interaction of salivary glycoproteins with Streptococcus sanguis and Streptococcus mutans.

Abstract: Four highly purified salivary glycoproteins were used to study salivary-bacterial interactions. One pair of glycoproteins was mucin-like in composition, whereas the second pair was not. By an agglutination assay, it was found that only the mucin-glycoproteins agglutinated Streptococcus sanguis and S. mutans. Removal of sialic acid from these molecules resulted in a loss of agglutination of S. sanguis but not of S. mutans. The agglutination phenomenon was shown to require a salivary macromolecule of at least 150,000 daltons.

Molecular symmetry. II. Gradient of electronic energy with respect to nuclear coordinates

Abstract: Symmetry methods employed in the HONDO ab initio polyatomic SCF program are extended to the analytic computation of energy gradients Validity of the Hellmann–Feynman theorem is not assumed, ie, all two‐electron contributions to the gradient are included explicitly The method is geared to the efficient computation of entire blocks of two‐electron integrals Just one of a set of symmetrically related blocks must be computed The gradient contribution from each unique block is multiplied by q4, the number of equivalent blocks, and added into a ’’skeleton gradient vector,’’ all other blocks are simply omitted After processing molecular integrals, the true gradient vector is generated by projecting the symmetric component out of the skeleton vector The analysis is based on Eqs (26) and (33) which are valid for many variational wavefunctions including restricted closed shell and unrestricted open shell self‐consistent field functions We also extend the use of translational symmetry proposed previously b

An optimized potential function for the calculation of nucleic acid interaction energies. I - Base stacking

Abstract: An optimized potential function for base-stacking interaction is constructed. Stacking energies between the complementary pairs of a dimer are calculated as a function of the rotational angle and separation distance. Using several different sets of atomic charges, the electrostatic component in the monopole-monopole approximation (MMA) is compared to the more refined segmented multipole–multipole representation (SMMA); the general features of the stacking minima are found to be correctly reproduced with IEHT or CNDO atomic charges. The electrostatic component is observed to control the location of stacking minima. The MMA, in general, is not a reliable approximation of the SMMA in regions away from minima; however, the MMA is reliable in predicting the location and nature of stacking minima. The attractive part of the Lennard-Jones 6–12 potential is compared to and parameterized against the expression for the second-order interaction terms composed of multipole-bond polarizability for the polarization energy and transition-dipole bond polarizabilities for approximation of the dispersion energy. The repulsive part of the Lennard-Jones potential is compared to a Kitaygorodski-type repulsive function; changing the exponent from its usual value of 12 to 11.7 gives significantly better agreement with the more refined repulsive function. Stacking minima calculated with the optimized potential method are compared with various perturbation-type treatments. The optimized potential method yields results that compare as well with melting data as do any of the more recent and expensive perturbation methods.

Enhanced biotransformation of theophylline in marihuana and tobacco smokers

Abstract: Single oral doses of theophylline were administered to 7 chronic marihuana smokers, to 7 chronic users of both marihuana and tobacco, and to 43 appropriate control subjects. Theophylline was cleared from the blood more rapidly in both marihuana and tobacco smokers with a mean increase in total clearance from 52 ml/kg/hr in nonsmokers to 74 ml/kg/hr in subjects who smoked either material alone. There was an additive increase in clearance to 93 ml/kg/hr in those who smoked both substances. Concern over enhanced metabolism of other drugs is probably warranted in tobacco and cannabis smokers.

Food, splanchnic blood flow, and bioavailability of drugs subject to first-pass metabolism

Abstract: There has been considerable interest in the past fifteen years in determining the influence of food and diet on gastrointestinal drug absorption. Welling21 has recently presented a comprehensive and critical review of these efforts. In general, food reduces the absorption rate of drugs from the gastrointestinal tract but in most instances has little influence on the extent of absorption. Such an effect is clinically significant for sedative-hypnotics and for other drugs where a prompt response is desired but is probably of little concern in most other cases. On the other hand, food has been found to substantially reduce the extent of absorption of certain drugs, including many antibiotics. This type of food effect often occurs with drugs with poor permeability characteristics that are incompletely absorbed even by fasting patients. Continual administration of such drugs with meals would result in lower steady-state drug concentrations in plasma than would be found were the drug to be given under fasting conditions.

Work and extra-work correlates of life and job satisfaction.

Abstract: A probability sample survey (n = 1,041) explored the relationship of both work-related and extra-workplace variables to four subjective quality of life measures: life satisfaction, life satisfactio...

Robustness of Conjoint Analysis: Some Monté Carlo Results:

Abstract: In many industrial applications of conjoint analysis the use of nonmetric algorithms to analyze respondent ranks of products described by more than eight or 10 attributes is time consuming and very...

Processing of Random Signals

Abstract: The experimentalist who is involved in dynamic flow measurement is almost always interested in some type of random signal processing. This interest can arise because the flow itself is random, as in turbulent flow. Or it can arise from concern about whether measured data represent real flow phenomena or merely statistical fluctuations in the data. These interests can occur simultaneously. For example, in the problem of determining periodicities in the turbulent flow behind a moving blade row the question of distinguishing between fluctuations in the data and the true spectral peaks is crucial to the experiment.

Relaxation methods for image reconstruction

Abstract: The problem of recovering an image (a function of two variables) from experimentally available integrals of its grayness over thin strips is of great importance in a large number of scientific areas. An important version of the problem in medicine is that of obtaining the exact density distribution within the human body from X-ray projections. One approach that has been taken to solve this problem consists of translating the available information into a system of linear inequalities. The size and the sparsity of the resulting system (typically, 25,000 inequalities with fewer than 1 percent of the coefficients nonzero) makes methods using successive relaxations computationally attractive, as compared to other ways of solving systems of inequalities. In this paper, it is shown that, for a consistent system of linear inequalities, any sequence of relaxation parameters lying strictly between 0 and 2 generates a sequence of vectors which converges to a solution. Under the same assumptions, for a system of linear equations, the relaxation method converges to the minimum norm solution. Previously proposed techniques are shown to be special cases of our procedure with different choices of relaxation parameters. The practical consequences for image reconstruction of the choice of the relaxation parameters are discussed.

Role of tobacco smoking in pharmacokinetics

Abstract: The pervasiveness of tobacco use in our society and the frequency of altered disposition and pharmacological effects of many common therapeutic and recreational drugs in smokers make it apparent that the smoking habit should be considered as one of the primary sources of drug interactions in man. Most of the experimental work in man, animals, and tissue on enzyme systems indicates that the dominant effect of smoking is enhanced disposition caused by induction of hepatic microsomal enzymes. The primary causal agents are probably the polynuclear aromatic hydrocarbons, which are potent and persistent in tissues. While several of the hepatic microsomal drug-metabolizing enzymes are stimulated in smokers, the selectivity of this enhancement in activity is unpredictable and the effects of tobacco smoke on other potential rate-limiting disposition processes are largely unexplored.

Clinical Pharmacokinetics of Aspirin

Abstract: Aspirin is very rapidly absorbed from the gastrointestinal tract when administered as a solution, and somewhat more slowly when administered in tablets. It is rapidly hydrolyzed in the body to salicylic acid; the plasma concentration of the latter must be maintained within a relatively narrow range to obtain an adequate anti-inflammatory effect and to minimize systemic adverse effects. The two major pathways of salicylate elimination, i.e., formation of salicyluric acid and salicyl phenolic glucuronide, become saturated at relatively low body levels of the drug. Consequently, steady-state ("plateau") salicylate levels increase more than proportionately with increasing daily dose, and the time required to reach steady state increases with increasing daily dose. The renal clearance of salicylic acid increases markedly with increasing urine pH; antacids capable of increasing urine pH can therefore cause a pronounced lowering of steady-state salicylate concentrations under clinical conditions. There are pronounced intersubject differences in salicylate elimination kinetics; dosage must be individualized on the basis of plasma concentration and clinical response. The drug is readily transferred across the placenta and is only slowly eliminated by the newborn infant. The drug is also transferred from mother to nursing infant through the breast milk.

Enzyme deactivation during cellulose hydrolysis

Abstract: Hydrolysis of cellulose by Trichoderma viride cellulase reached a plateau after some 25 hr. If the initial enzyme-to-substrate ratio was low, resuspension of substrate in fresh enzyme or addition of enzyme resulted in further high rate hydrolysis. This did not occur if the initial ratio was high. Over 75% hydrolysis might be achieved in the former case, while less than 60% in the latter. A model postulating inactivation of adsorbed enzyme–substrate complex which blocked further hydrolysis was proposed, and it was found to fit the data well. The proposed model had five parameters, four of which could be checked by graphical methods, and all of which had physical meanings. The parameters were estimated by a nonlinear least-squares minimization FORTRAN computer program, using numerical integration and optimization of the parameters. The model was used to predict the resuspension data, powdered enzyme addition data, cellobiose addition data, and cellulose addition data; the deviations from the model are discussed. It was found that average values could be used for four out of the five parameters, while the fifth (initial enzyme concentration) did not correlate with independent measurements such as the filter paper activity or protein concentration.

The effect of area, density, and number of background characters on visual search

Abstract: In a search task, area of search field, density of background characters, and number of background characters are not independent Many authors have found increases in search times with each of these factors but have not adequately controlled all three together In this experiment, eight subjects searched a set of search fields covering combinations of all three variables Search time was found to depend most heavily on number of background characters, but there were significant effects due to the other two variables For a constant number of background characters, search time decreases as density increases Direct visual lobe measurements confirmed these findings, which could have importance in visual inspection tasks

Theophylline disposition in obesity.

Abstract: Theophylline disposition was examined in 14 obese subjects and 57 normal subjects. A single oral dose of aminophylline solution was given and serum and saliva samples were collected over several hours and assayed by high-pressure liquid chromatography. The apparent volume of distribution (Vd) and body clearance (ClB) were analyzed for total body weight (TBW) and ideal body weight (IBW). The Vd averaged 0.482 (SD = 0.084) L/kg TBW in normals vs 0.382 (0.069) L/kg TBW and 0.77 (0.189) L/kg IBW in obese subjects. The ClB averaged 63.0 (28.5) ml/hr/kg IBW in normals compared to 32.8 (11.1) ml/hr/kg TBW and 64.1 (20.8) ml/hr/kg IBW in obese subjects. Similar Vd values between the two groups when TBW is used indicates that loading dose is best calculated based on TBW. Similar ClB based on IBW in normal and obese subjects indicates that IBW should be used to calculate maintenance doses for theophylline. Mean half-lives were longer in obese subjects than in normals, 8.6 (2.0) and 6.0 (2.1) hr, respectively, suggesting that obese patients may need less frequent dosing.

Organizational communication: 1978

Abstract: With roots in social psychology, human relations, and organizational theory and behavior, the discipline of organizational communication has emerged in the last 25 years with its own content, methodology, and applications. Although one of the first major literature reviews of this field was produced about 15 years after much of the early foundation research had been completed (Guetzkow, 1965), the next major reviews were published in half the time (Porter & Roberts, 1972; Redding, 1972). As further evidence of the sheer quantity of research being completed in this new discipline, four additional reviews and syntheses were published during the next four years (Pietri et al., 1974; Goldhaber, 1975; Bernstein, 1976; Richetto, 1977). In fact, as Richetto closed his 1976 overview of the field, he predicted that there would “likely be continued attempts at integrating and synthesizing findings” (p. 336). Little did he realize that within two years, three additional reviews would appear (Dennis, Goldhaber, Yates, 1978; Farace, Taylor, Stewart, 1978; Monge, Edwards, Kirste, 1978). The present synthesis and review, with its emphasis on findings and implications, combines the results of recent North American and European research with those of the first 16 studies completed by the International Communication Association (1CA) Communication Audit. We have divided the review into three major sections: a historical overview of the major findings from both North America and Europe; major findings from the ICA Communication Audit; and implications of all major findings for future research.

The Avian Egg: In vivo Conductances to Oxygen, Carbon Dioxide, and Water Vapor in Late Development

Abstract: In vivo measurements of both O2 and water vapor conductances(\({\text{G}}_{{\text{O}}_{\text{2}} }\) and \({\text{G}}_{{\text{H}}_{\text{2}} {\text{O}}} \)) were made at 38°C on the same hen’s eggs between days 12 and 18 of incubation. Neither \({\text{G}}_{{\text{O}}_{\text{2}} }\) or \({\text{G}}_{{\text{H}}_{\text{2}} {\text{O}}}\) changed systematically during this phase of incubation. Average \({\text{G}}_{{\text{O}}_{\text{2}} }\) (cm3/day/torr) was 12.60 ± 0.30 (S.D.); average \({\text{G}}_{{\text{H}}_{\text{2}} {\text{O}}}\), 15.26 ± 0.51; \({\text{G}}_{{\text{O}}_{\text{2}} } \)/\({\text{G}}_{{\text{H}}_{\text{2}} {\text{O}}} \)= 0.83. In vivo determination of \( {\text{G}}_{{\text{CO}}_{\text{2}} } \) and \({\text{G}}_{{\text{H}}_{\text{2}} {\text{O}}} \) in a second group of eggs gave values of 9.22 ± 1.54 and 14.60 ± 0.65, respectively; \({\text{G}}_{{\text{CO}}_{\text{2}} }\)/\({\text{G}}_{{\text{H}}_{\text{2}} {\text{O}}}\)= 0.64. The conductance ratios agree closely with the binary diffusivity ratios (in air or N2) of the gases in question. We conclude that O2, CO2, and water vapor diffuse between environment and air cell of the chicken egg via the same diffusion path, whose chief resistance lies in the shell itself. The outer shell membrane offers little resistance in vivo to passage of gas molecules.