Showing papers by "University of Kentucky published in 1984"

Environmental Boundary Spanning and Information Processing Effects on Organizational Performance

Abstract: The boundary spanning activity of the entrepreneur is used to examine the strategic management process in small business. In a sample of 82 owner/operators, intensive boundary spanning activity was...

Propionate may mediate the hypocholesterolemic effects of certain soluble plant fibers in cholesterol-fed rats.

Abstract: The effects of propionate on serum and liver lipid concentrations were studied in cholesterol-fed rats. Both serum and liver cholesterol levels were significantly lower in rats fed the cholesterol-propionate diet than in rats fed the cholesterol diet without propionate. Liver triglyceride levels were also significantly lower in the propionate-treated group. Serum triglyceride concentrations were not influenced by the propionate feeding. Propionate intake was not associated with histologic changes in liver tissue. This study indicates that 0.5% sodium propionate-supplemented diets slightly but significantly reduced cholesterol accumulation in both serum and liver of cholesterol-fed rats. Thus propionate, a metabolic product of fiber fermentation, may mediate some of the hypocholesterolemic effects of certain soluble plant fibers.

The history of feed analysis, as chronicled in the development of AOAC official methods, 1884-1984.

Abstract: Etude d'apres la bibliographie publiee depuis 100 ans, de l'evolution des techniques analytiques

Uses and Gratifications: A Theoretical Perspective

Abstract: (1984). Uses and Gratifications: A Theoretical Perspective. Annals of the International Communication Association: Vol. 8, Communication Yearbook 8, pp. 20-55.

Optical properties of pyrolytic boron nitride in the energy range 0.05—10 eV

Abstract: Optical reflectance studies of the $c$ face of pyrolytic boron nitride were carried out at room temperature in the photon energy range 0.45---10 eV. A Kramers-Kronig analysis was performed to determine the in-plane real (${\ensuremath{\epsilon}}_{1}$) and imaginary (${\ensuremath{\epsilon}}_{2}$) dielectric functions. Infrared-active transverseoptic phonons were observed at 770 and 1383 ${\mathrm{cm}}^{\ensuremath{-}1}$. Strong impurity- and defect-associated absorption was observed throughout the visible and near-ultraviolet region (1---5 eV) which masks, to some extent, the threshold for absorption across the electronic energy band gap. From ${\ensuremath{\epsilon}}_{2}(\ensuremath{\omega})$ and the absorption coefficient we estimate the direct band gap between $\ensuremath{\pi}$ bands to be 5.2\ifmmode\pm\else\textpm\fi{}0.2 eV. Interband transitions associated with high joint density of states were observed at 6.10 and 6.85 eV. The structure in ${\ensuremath{\epsilon}}_{2}(\ensuremath{\omega})$ at energies $\ensuremath{\hbar}\ensuremath{\omega}g5$ eV is identified with specific transitions predicted by previous energy-band calculations.

A comparison of spindle concentrations in large and small muscles acting in parallel combinations

Abstract: A small short muscle frequently acts across a joint in parallel with a vastly larger and longer muscle; therefore it should play a minimal role in the mechanical control of that joint. This study provides evidence suggesting that the small member of such a "parallel muscle combination" (PMC) may serve an important sensory feedback role. The spindle densities of large and small members of PMCs in man and the dog were determined and compared. Epaxial PMCs controlling canine intervertebral joints were dissected and tissue samples were embedded in paraffin, sectioned transversely to the muscles' long axis and, stained with hematoxylin-periodic acid-Schiff (PAS). Representative tissue sections were projected on to stereological grids and the percentage volume of spindles was determined. Data existing in the literature were used to ascertain spindle densities in human PMCs controlling joints in the cervico-occipital region and the extremities. The spindle density for each muscle in a group of PMCs controlling a particular motion was listed, and the mean spindle densities were determined for both the large and the small members of the group. Student's unpaired t test was used to determine the significance of the differences between mean spindle densities. Linear regression was calculated and the data were plotted graphically. In all PMCs examined, the spindle density of the small muscles was significantly higher than that of their large counterparts. It is therefore proposed that the small muscles of PMCs may function as "kinesiological monitors" generating important proprioceptive feedback to the central nervous system.

A Two-Stage Cross Correlation Approach to Template Matching

Abstract: Two-stage template matching with sum of absolute differences as the similarity measure has been developed by Vanderburg and Rosenfeld [1], [2]. This correspondence shows the development of two-stage template matching with cross correlation as the similarity measure. The threshold value of the first-stage is derived analytically and its validity is verified experimentally. Considerable speed-up over the one-stage process can be obtained by introducing only a small false dismissal probability.

Short-Chain Fatty Acid Fermentation Products of Plant Fiber Affect Glucose Metabolism of Isolated Rat Hepatocytes

Abstract: Short-chain fatty acids (SCFA) produced during fermentation of plant fibers and absorbed from the colon may affect hepatic glucose metabolism. We examined the effects of different fatty acids on rates of glucose production and glycolysis in isolated rat hepatocytes. Acetate, butyrate, and long-chain fatty acids significantly increased glucose production from lactate. However, propionate and valerate significantly decreased glucose production from lactate. Whereas 5 mM butyrate increased the incorporation of [14C]lactate into [14C]glucose by 80%, 5 mM propionate produced a 67% decrease. Glycolysis was significantly decreased by acetate, butyrate, and long-chain fatty acids. However, propionate and valerate significantly increased glycolysis. Thus propionate, which inhibits hepatic acetate metabolism, acts to increase glucose use and decrease glucose production. Plant fibers may influence hepatic glucose metabolism via their SCFA metabolites.

Merging uses and gratifications and expectancy-value theory

Abstract: This investigation provides support for a process model of uses and gratifications based upon an expectancy-value approach. Results of the study supported the hypothesis that gratifications obtained are strongly related to the beliefs about media attributes but are not related to evaluations of those attributes. Also, the belief X evaluation products are correlated with gratifications obtained. When controls were instituted for certain intervening variables posited by the model, the hypothesized reductions in various relationships occurred. The model has significant implications for media consumption processes. Further, the results demonstrated that gratifications sought and obtained may be measured at the same level of abstraction, contrary to earlier speculation.

Relative toxicities of chemicals to the earthworm Eisenia foetida

Abstract: In the present study, 90 chemicals were tested against Eisenia foetida for the purpose of using this organism as the marker species to indicate the relative toxicities of chemicals to earthworms and other soil invertebrates. The worms were exposed to deposits of the chemicals on filter paper for 48 h and the mortality was recorded; concentrations were expressed in μg/cm2. Based on the resulting LC50 values, the chemicals were classified as supertoxic ( 1,000 μg/cm2). Of the chemicals tested (pesticides, solvents, metals, drugs, carcinogens, etc.), only carbofuran and eserine salicylate, both carbamates, were supertoxic. The remaining chemicals were distributed about equally among the other toxicity categories. The most surprising results were that the phenolic hydrolytic products of parathion, carbaryl, 2,4-D and 2,4,5-T were as toxic, or more toxic, than the parent material, with all of these compounds falling within the extremely toxic and very toxic classifications. Several chemicals, considered only moderately or relatively nontoxic to mammals, were extremely or very toxic to earthworms; among these compounds were carbaryl, malathion, cypermethrin and benomyl. The results of this study further demonstrate the unpredictability of chemical toxicity to different animal species, a fact which complicates the assessment of environmental risk to one or more species based on data attained with another.

Effective and Efficient Procedures for the Transfer of Stimulus Control.

Abstract: This paper describes and reviews procedures for transferring stimulus control. Assumptions for using these procedures are included. Four response prompting and two stimulus manipulation procedures are discussed. The response prompting procedures are most-to-least prompts, graduated guidance, system of least prompts, and time delay. The stimulus manipulation procedures are stimulus shaping and stimulus fading. Recommendations concerning the use of these procedures by teachers are made, and questions for further research are noted.

Use, Misuse, and Role of Multiple-Comparison Procedures in Ecological and Agricultural Entomology

Abstract: Multiple-comparison procedures for comparing means, medians, or proportions are commonly used by entomologists publishing in ecological and agricultural journals of the Entomological Society of America. Unfortunately, there is confusion among many researchers and reviewers with respect to the type I error rates of the various tests. The calculation of and reasoning behind the error rate and relative conservativeness or liberalness of each test are discussed. Several guidelines concerning use of these tests are proposed, including specification of which test was used and why, and a recommendation encouraging a switch to the use of confidence intervals instead of hypothesis tests. It is felt that adoption of these and other proposals for reporting results will increase the meaningfulness and scientific merit of published entomological research.

The numerically stable reconstruction of Jacobi matrices from spectral data

Abstract: We present an expose of the elementary theory of Jacobi matrices and, in particular, their reconstruction from the Gaussian weights and abscissas. Many recent works propose use of the diagonal Hermitian Lanczos process for this purpose. We show that this process is numerically unstable. We recall Rutishauser's elegant and stable algorithm of 1963, based on plane rotations, implement it efficiently, and discuss our numerical experience. We also apply Rutishauser's algorithm to reconstruct a persymmetric Jacobi matrix from its spectrum in an efficient and stable manner.

Clinical Pharmacokinetics of Verapamil

Abstract: Verapamil is widely used in the treatment of supraventricular tachyarrhythmias as well as for hypertension and control of symptoms in angina pectoris. Unlike other calcium antagonists, detailed pharmacokinetic data are available for verapamil. Plasma concentrations of verapamil appear to correlate with both electrophysiological and haemodynamic activity after either intravenous or oral drug administration, although considerable intra- and intersubject variation has been found in the intensity of pharmacological effects resulting at specific plasma drug levels.

Salt-sensitive hypertension: contribution of chloride

Abstract: The effect of the anion associated with sodium loading on the development of hypertension in the Dahl salt-sensitive rat was determined. For 5 weeks rats were fed a diet containing normal or high concentrations of sodium chloride or high concentrations of sodium provided as a mixture of sodium bicarbonate, phosphate, and amino acids. After 1 week on these diets and until the end of the study the rats receiving high concentrations of sodium chloride had higher systolic blood pressures than the rats in the other two groups. There were no statistically significant group differences in plasma volume, arterial pH, or plasma concentrations of Na+, K+, Cl-, Ca2+, or creatinine, or in renomedullary prostaglandin E2 production. Compared to the animals receiving normal concentrations of sodium chloride, those receiving high concentrations of sodium chloride or amino acids showed decreased plasma renin activity and plasma aldosterone concentrations. Thus, the anion ingested with sodium alters the development and severity of hypertension in the Dahl salt-sensitive rat.

Clinical evaluation of patients eight to nine years after placement of removable partial dentures

Abstract: Removable partial dentures, constructed following principles outlined in this study, provided reasonable service for an 8- to 9-year period for patients who were wearing them. The oral hygiene of the patients was less than ideal. Few teeth were lost by patients in the study. There were no significant differences in caries incidence, changes in sulcus depths, tooth mobility, or alveolar bone loss between patients who were wearing their dentures and those who were not. There were increased levels of gingival inflammation seen in regions covered by the removable partial dentures and in gingivae apical to clasp arms. Other than these findings, there seemed to be no direct evidence that the removable partial dentures were causing dental or periodontal breakdown.

Relative biological effectiveness of modulated proton beams in various murine tissues

Abstract: The relative biological effectiveness (RBE) of proton beams produced by Harvard University 160 MeV synchrocyclotron was studied in various murine tissues. Reference radiation was Cobalt-60 gamma-rays from a teletherapy unit at the Massachusetts General Hospital. Animals were C3Hf/Sed mice derived from our defined flora mouse colony. Test tissues are: lens, lung, testes and tail vertebrae. The RBE of the third generation isotransplants of a spontaneous mouse mammary carcinoma was also investigated. The proton and Cobalt-60 irradiations were carried out simultaneously by 2 teams. The dose response curves obtained for testes weight loss and growth stunting of tail vertebrae indicated that the RBE for our protons was independent of radiation dose in the range of 0.4 to 16 Gy. This finding was identical to our previous studies of the murine fibrosarcoma, skin and small intestine. The RBE values for lens and lung tissues were obtained by determining radiation dose to result in a complete cataract in half the irradiated eyes in 210 days and a 50% mortality in 180 days respectively. We have studied proton RBE in 7 normal tissues and 2 tumors including previously reported results. The RBE values for these tissues were found to fall between 1.09 and 1.32. No significant differences in the proton RBE were found between the several normal and tumor tissues studied.

The Evolution of Neuroanatomical Substrates of Reproductive Behavior: Sex Steroid and LHRH-Specific Pathways Including the Terminal Nerve

Abstract: Fairly recent anatomical methods have made possible the mapping of neurobehavioral systems involving two types of reproductive hormones, gonadal steroids and the peptide luteinizing hormone releasing hormone (LHRH). Brain sites of steroid uptake are detected using autoradiography; LHRH is localized in cells and fibers using immunocytochemical procedures. Both hormone types are known to strongly influence sex behavior and it can reasonably be assumed that these effects are mediated in large part via systems identified using the anatomical procedures. Analysis of the comparative anatomy of these systems should therefore provide information useful in the construction of models concerning the evolution of neurohormonal control of reproductive behavior. The results of such a study are reported. Sex steroid and LHRH systems in cyclostomes, teleosts, amphibians, reptiles, birds and mammals are considered in detail. A synthesis of this information has led to the following ideas. Androgenic control of male reproductive systems has evolved in a number of nonhomologous motor systems controlling male reproductive behavior. Sex steroid and LHRH systems may interact at several different levels of the neuraxis but the most obvious overlap of the systems occurs in the septal and POA areas. The latter especially is a fairly constant and perhaps primitive feature. LHRH secretion into the systemic circulation was most likely the earliest means for LHRH modulation of both pituitary function and neural systems controlling reproductive behavior.Pathways for more direct delivery of LHRH to pituitary cells and brain nuclei probably developed in the early gnathostomes. The terminal nerve appears to be a rather conservative LHRH-containing pathway connecting olfactory systems with septal-preoptic nuclei. A function in pheromonal control of sex behavior is suggested. The general distribution of steroid concentrating cells and LHRH pathways in tetrapods seems to be rather constant. Absence of the systems in neocortical areas and their homologs is conspicuous.

Conditioned place preference with morphine: The effect of extinction training on the reinforcing CR

Abstract: Rats were injected with either morphine (5 mg/kg) or saline in association with one set of distinct environmental stimuli, and injected with saline in association with a different set of stimuli. After four conditioning trials, animals were given a 15-minute free-choice test to determine which stimulus environment was preferred. Animals displayed CPP as a significant increase in duration spent within the morphine-associated environment, but did not display any change in number of entries into that environment. In contrast, when extinction training was given following CPP, animals displayed a significant decrease in duration spent per entry into the morphine-associated environment, but did not display any change in total duration spent in that environment. These results suggest that assessment of the reinforcing conditioned response (CR) in the CPP model may require measurement of both duration spent in and number of entries into the drug-associated environment.

Age at treatment and long-term performance results in medulloblastoma.

Abstract: Medulloblastoma is highly radioresponsive, and recent treatment results have improved greatly since the introduction of megavoltage machine in 1960s There is increasing evidence for the potential cure of medulloblastoma if properly treated in its early stages The curable group represents approximately 75% of diagnosed patients Long-term treatment effects were examined in this study The study reveals age-dependent late effects in learning ability; the patients less than 4-years-old at treatment had major learning problems; patients of 5 to 7 years old performed at satisfactory-to-low passing levels in school work; patients older than 8 years old had no major intellectual impairment Short stature was common when growth potential was present at the time of therapy, but endocrine tests were generally negative These observations indicate special educational requirement needs, especially for children treated at a young age

Changes in Soil Properties Under No-Tillage

Abstract: When farmers shift from a system of agricultural production that includes numerous tillage operations to a reduced or no-tillage system it is reasonable to show concern about how this change in soil management may affect soil properties. For any crop production system to be widely accepted and used it must maintain the physical properties of the soil, and allow for replacement of nutrient removal and other losses. It must also maintain a soil environment favorable for the numerous necessary biological reactions. The microbial activity of the soil is largely determined by the chemical and physical properties of the soil. For example, the placement and amount of organic material directly influences biological activity, as it also does the chemical and physical properties.

Effective Direct Instruction Practices in Special Education Settings

Abstract: This study examined effective and less effective teachers of special education students as differentiated by their direct instruction practices. Twenty-eight teacher interns were equally divided into two effectiveness groups based on their students' achievement. Each group was observed teaching lessons to special education students. Analyses of teacher behavior indicated that more effective teachers maintained a brisker lesson pace, had higher student accuracy, and prompted rather than told correct answers following student errors. The results of the study support prior research in teacher effectiveness and the hypothesis that teacher behavior is an important factor contributing to student achievement.

Effect of pH on Crystal Phase of ZrO2 Precipitated from Solution and Calcined at 600°C

Abstract: The pH of the solution from which the gel is precipitated determines the calcined zirconia crystal phase. Monoclinic zirconia is produced from materials precipitated in the 6.5 to 10.4 pH range; the tetragonal precursor is obtained for the 3 to 4 or 13 to 14 pH range. The calcination atmosphere, temperature history during calcination, and the presence of alkali do not appear to play a dominant role in determining the zirconia phase composition.

Evidence for direct roles of calcium in photosynthesis

Abstract: Calcium may function directly in several aspects of photosynthesis. It appears to modulate activity of the phosphatase enzymes in the carbon reduction cycle and also to regulate chloroplast NAD+ kinase activity through a calmodulin-like protein. Some evidence supports a calcium function in the water-splitting complex, and other evidence indicates a reaction center function in photosystem II. Calcium in reaction center II may be tightly bound in chloroplasts and weakly bound in blue-green algal thylakoids. Free calcium concentration in stroma is probably less than 10(-6) M, although the absolute concentration is not yet known. Intrathylakoid calcium content is likely very high. Stromal calcium may regulate several enzyme activities, while intrathylakoid calcium may promote photosystem II constitutively. Results to date demonstrate the need for more attention to cation composition in studies of both light and dark reactions of photosynthesis, and the need to identify free calcium levels in chloroplasts.