Showing papers by "University of Utah published in 1971"
TL;DR: In this article, an empirical equation which correlates the relative viscosities of suspensions (or relative moduli of filled polymeric materials) as a function of solids concentrations and particle size distributions is proposed.
Abstract: The dependence of the viscosities of highly concentrated suspensions on solids concentrations and particle size distributions is investigated by using an orifice viscometer. Based on the extensive amount of data on pertinent systems, an empirical equation which correlates the relative viscosities of suspensions (or relative moduli of filled polymeric materials) as a function of solids concentrations and particle size distributions is proposed. The equation has a constant which characterizes size distributions of spherical particles and can be determined experimentally without measuring viscosities. For uniform-size spherical particles, it reduces to the well-known Einstein equation at dilute solids concentrations.
707 citations
TL;DR: The surface is approximated by small polygons in order to solve easily the hidden-parts problem, but the shading of each polygon is computed so that discontinuities of shade are eliminated across the surface and a smooth appearance is obtained.
Abstract: A procedure for computing shaded pictures of curved surfaces is presented. The surface is approximated by small polygons in order to solve easily the hidden-parts problem, but the shading of each polygon is computed so that discontinuities of shade are eliminated across the surface and a smooth appearance is obtained. In order to achieve speed efficiency, the technique developed by Watkins is used which makes possible a hardware implementation of this algorithm.
661 citations
TL;DR: ‘Anaemia of chronic disorders’, though a less restrictive title, is unsatisfactory because many other types of anaemia occur in these disorders, such as blood loss, overt haemolytic anaemia of various types, reactions to drugs, myelophthisic anaemia, and the anaemic of renal failure.
Abstract: Although the anaemia associated with chronic disorders is one of the most frequently encountered forms of anaemia, particularly in hospital patients, it has not received the distinction which it deserves, in part, perhaps, because of the lack of an appropriate name. The term ‘simple chronic anaemia’ is most inappropriate because the pathogenesis of the anaemia involves the delicate control mechanisms of erythropoiesis and these are not simple. The title ‘anaemia of chronic infections’ is much too restrictive, for the anaemia occurs in patients with cancer, lymphoma, rheumatoid arthritis, collagen vascular diseases, fractures, severe tissue injury and many other disorders. ‘Anaemia of chronic disorders’, though a less restrictive title, is unsatisfactory because many other types of anaemia occur in these disorders, such as blood loss, overt haemolytic anaemia of various types, reactions to drugs, myelophthisic anaemia, and the anaemia of renal failure. Furthermore, the name gives no hint as to the diagnostic features or pathogenesis of the anaemia. A more descriptive, but somewhat more cumbersome, title might be ‘sideropenic anaemia with reticuloendothelial siderosis.’
268 citations
TL;DR: In this article, an analysis of strains and stresses in four-point bending creep tests in the limit of small beam deflections resulted in a general equation which relates the load-point deflection, the applied load, the creep exponent (N), and the geometrical parameters of the loading system.
Abstract: An analysis of strains and stresses in four-point bending creep tests in the limit of small beam deflections resulted in a general equation which relates the load-point deflection, the applied load, the creep exponent (N), and the geometrical parameters of the loading system. Measurements of load-point deflection rates, which are experimentally easy to accomplish in ceramic systems, vs the applied load lead to the direct determination of the creep exponent and the creep compliance in a steady-state creep test. The creep compliance is a function of the temperature, grain size, and all other factors except stress. The elastic equation relating the load-point deflection and the outer fiber strain is strictly valid for viscous creep and approximately valid for nonviscous creep (i.e. N>1) if the ratio of the distance between the support points to the distance between the load points is not very large.
238 citations
TL;DR: A pattern of selectivity by different blockers suggests that the properties of the cholinergic receptors of the two ganglion cell populations may differ qualitatively.
181 citations
TL;DR: Because the tails have no apparent associations with cells in the hypothalamic nuclei, the functional interactions of tanycytes with hypothalamic neuropil are probably confined to the periventricular layer.
Abstract: Tanycytes along the third ventricle have been studied in adult rat and mouse brains with the rapid Golgi method. A tanycyte can be divided into three portions: somatic, neck, tail. The somatic portion is in the ependymal layer and frequently has thin cytoplasmic extensions. The neck portion originates from the soma and sticks into the periventricular layer. It, too, has numerous fine lamellar processes radiating from it. The neck contacts a blood vessel. Distal to this contact, the neck becomes thin and devoid of its cytoplasmic processes. This is the tail portion, which courses through hypothalamic nuclei to terminate as small bulbous swellings either on a vessel or at the pial surface.
115 citations
TL;DR: It was concluded that both activity and emotionality are associated with an activation of dopamine neurones, and an increase in activity in the absence of stress will accelerate the metabolism of dopamine.
110 citations
TL;DR: Afferent fibers in cardiac sympathetic nerves were stimulated electrically in an attempt to evoke circulatory reflexes in vagotomized intact-brain or spinal cats and revealed that excitation of Aσ fibers in the inferior cardiac nerve elicited a weak pressor response, andexcitation of C fibers provoked a much stronger response.
Abstract: Afferent fibers in cardiac sympathetic nerves were stimulated electrically in an attempt to evoke circulatory reflexes. A pressor response was always elicited during stimulation of the central end of the cut left inferior cardiac or pericoronary nerve in vagotomized intact-brain or spinal cats. The maximum blood pressure rise was 21.5 mm Hg during inferior cardiac nerve stimulation and 14.1 mm Hg during pericoronary nerve stimulation. Heart rate and respiration were unaffected by stimulation. The alpha-receptor-blocking agent phenoxybenzamine hydrochloride abolished the pressor response. Sequential sectioning of cardiac nerves arising from either the stellate ganglion or the thoracic sympathetic trunk, or of white rami 1 through 4, indicated that each branch carried afferents contributing to the pressor response. Evoked potentials revealed that excitation of Aδ fibers in the inferior cardiac nerve elicited a weak pressor response, and excitation of C fibers provoked a much stronger response. C fiber continuity between the pericoronary nerve and the inferior cardiac nerve was demonstrated.
106 citations
TL;DR: The clinical course and histopathological characteristics of the chronic phase of mouse arthritis induced by M. arthritidis closely resembled those of rheumatoid arthritis of man.
Abstract: Mice injected intravenously with Mycoplasma arthritidis developed a chronic arthritis which persisted through at least 269 days. Rats similarly treated developed an acute short-term infection. The mouse disease was characterized by periods of remission and exacerbation and was proliferative in nature, gradually spreading to adjacent joints. M. arthritidis strain 158 P10 was found to be less arthritogenic for mice than for rats, but further passage of this strain in mice substantially increased its virulence. Unlike rats, mice appeared to be susceptible to a "toxin" of M. arthritidis and they developed a necrotic spreading abscess after subcutaneous administration of the organisms. Histopathological studies revealed that mice varied greatly in the degree of joint inflammation, destruction, and repair. The disease was characterized by (i) an initial acute phase with infiltration of the articular and periarticular tissues with polymorphonuclear leukocytes and a mild hyperplasia of the synovial membrane; (ii) a mixed acute-chronic phase in which new areas of acute inflammation developed alongside areas of chronic lesions; (iii) a chronic phase followed which was characterized by massive synovial proliferation with mononuclear cell infiltration, irregularity in the articulating cartilage, pannus formation, and "punched out" defects in cortical bone near cartilagenous osseous junctures. The clinical course and histopathological characteristics of the chronic phase of mouse arthritis induced by M. arthritidis closely resembled those of rheumatoid arthritis of man.
102 citations
TL;DR: The familiar matching relationship, obtained previously only with concurrent schedules, was obtained in multiple schedules with a short component duration, as the component duration was shortened and the relative frequency of responding in a component closely approximated the relative Frequency of reinforcement in that component.
Abstract: Three pigeons performed on two-component multiple variable-interval variable-interval schedules of reinforcement. There were two independent variables: component duration and the relative frequency of reinforcement in a component. The component duration, which was always the same in both components, was varied over experimental conditions from 2 to 180 sec. Over these conditions, the relative frequency of reinforcement in a component was either 0.2 or 0.8 (+/-0.03). As the component duration was shortened, the relative frequency of responding in a component approached a value equal to the relative frequency of reinforcement in that component. When the relative frequency of reinforcement was varied over conditions in which the component duration was fixed at 5 sec, the relative frequency of responding in a component closely approximated the relative frequency of reinforcement in that component. That is, the familiar matching relationship, obtained previously only with concurrent schedules, was obtained in multiple schedules with a short component duration.
96 citations
TL;DR: The results suggest that all patients treated with gentamicin deserve more adequate monitoring of renal function and point out the need for large scale studies to identify those patients with the greatest risk of nephrotoxicity.
Abstract: The records of 100 consecutive patients treated with gentamicin at a university hospital were studied for evidence of nephrotoxicity due to gentamicin. Inadequate monitoring of renal function was found in 23 cases; among the remaining 71 patients who were given 77 courses of gentamicin, 32 had renal insufficiency during treatment as manifested by increases in blood urea nitrogen and serum creatinine. The role of gentamicin in these instances of renal insufficiency was unclear in the majority of cases, but gentamicin was thought to be the major cause of renal failure in five cases. None of the patients died of renal failure, and in all patients the indices of renal function returned to pretreatment values after the drug was stopped. The results suggest that all patients treated with gentamicin deserve more adequate monitoring of renal function and point out the need for large scale studies to identify those patients with the greatest risk of nephrotoxicity.
TL;DR: A theory which embraces several classes of methods which can be used to find additional solutions of a nonlinear system of equations is presented and the theory is extended to the multiple root problem.
Abstract: This paper defines several classes of methods which can be used to find additional solutions of a nonlinear system of equations. A theory which embraces these classes is presented and the theory is extended to the multiple root problem. The techniques developed can also be used in avoiding previously found extreme points when performing function minimization. Results of computer experiments are presented.
TL;DR: Chinese hamster cells were labelled with [3H]thymidine after fluorodeoxyuridine treatment and autoradiograms indicate that in each replicon, replication proceeds via a single replication fork.
TL;DR: In this paper, the gravity-driven coalescence of 1-to 2-cm. diameter air bubbles in glycerine and in water has been studied by high-speed cinematography.
Abstract: The gravity-driven coalescence of 1- to 2-cm. diameter air bubbles in glycerine and in water has been studied by high-speed cinematography. The resulting coalescence behavior can be correlated by a simple model which assumes that each bubble trails a wake, and that the bubble coalescing from below accelerates when it enters the wake of the preceding bubble and thus overtakes the first bubble. The predictions of the model are not significantly altered by different assumed wake configurations.
TL;DR: Measurement of electrolyte activity in the abdominal ganglion cells of Aplysia shows that the effect probably arises from changes in membrane permeability to potassium.
Abstract: It has been suggested that some inhibitory postsynaptic potentials in the abdominal ganglion cells of Aplysia may reflect activation of the sodium pump by acetylcholine. Measurement of electrolyte activity, however, shows that the effect probably arises from changes in membrane permeability to potassium.
TL;DR: The observed Zeeman splitting of 2p-1 and 2po donor states in GaAs in the magnetic field range 20-55 kG is accounted for by the effective mass theory for isolated hydrogenic donors to an accuracy of 0.15 per cent as mentioned in this paper.
01 Jun 1971
TL;DR: In this article, a theoretical analysis of the relative resolving power of equilibrium-gradient separation methods, such as isoelectric focusing and density-gradient sedimentation, and corresponding kinetic methods such as electrophoresis and kinetic centrifugatipn.
Abstract: A theoretical analysis is made of the relative resolving power of equilibrium-gradient separation methods, such as isoelectric focusing and density-gradient sedimentation, and the corresponding kinetic methods, such as electrophoresis and kinetic centrifugatipn. Both general and specific equations are derived for resolution and peak capacity. It is concluded that peak capacity, the most general index of over-all resolving power, is of comparable magnitude for these two different approaches. Two new equilibrium-gradient methods of separation are proposed, these employing dielectrical and thermal diffusion forces, respectively.
TL;DR: This chapter discusses the analysis of pain as a specific sensation, and sets down attributes that might be accepted for this category in the light of Aristotle's view in setting pain opposite to pleasure and assigning it to the realm of emotion.
TL;DR: Round and amoeboid microglial cells in brains of neonatal rabbits have been studied with light and electron microscopy and further work is in progress to establish their origin and fate.
Abstract: Round and amoeboid microglial cells in brains of neonatal rabbits have been studied with light and electron microscopy. They are present mainly in the white matter where there are large extracellular spaces, but a few occur in the vicinity of blood vessels in the basal ganglia. They are easily recognized by the shape of their processes. Both round and amoeboid cells are highly differentiated cells whose size and cytoplasmic vacuoles are similar to phagocytes. They lack the fibrils and microtubules of young nerve and glial cells and contain a rich complement of cytoplasmic organelles. Large numbers of lipid bodies and vacuoles are their most characteristic features. Small vacuoles are concentrated near the cell surface and contain material identical to that filling the extracellular space. They appear to arise as invaginations at the cell surface, to unite to form large vacuoles, and to increase in density as their contents are degraded. The role of these cells in the embryonic development of the brain is not clear and further work is in progress to establish their origin and fate.
TL;DR: Neuropile of the amphibian spinal cord was studied by light and electron microscopy to determine whether there are intercellular relations involving dendrites which would provide support for electrical interaction between montoneuron dendrite and neuron somata.
18 Oct 1971
TL;DR: The I/O System is described and some popular applications of it, illustrating these features, are presented, which permit one to take full advantage of all features of an I/o device but require considerable knowledge of the I/0 System and the device.
Abstract: An I/0 system has been implemented in the Multics system that facilitates dynamic switching of I/0 devices. This switching is accomplished by providing a general interface for all I/O devices that allows all equivalent operations on different devices to be expressed in the same way. Also particular devices are referenced by symbolic names and the binding of names to devices can be dynamically modified. Available I/0 operations range from a set of basic I/0 calls that require almost no knowledge of the I/O System or the I/0 device being used to fully general calls that permit one to take full advantage of all features of an I/O device but require considerable knowledge of the I/0 System and the device. The I/O System is described and some popular applications of it, illustrating these features, are presented.
TL;DR: In this paper, the wave functions produced by a new band calculation for ferromagnetic iron are examined by computing from them charge and spin densities both at the nuclear position and at other positions throughout the unit cell.
Abstract: The wave functions produced by a new band calculation for ferromagnetic iron are examined by computing from them charge and spin densities both at the nuclear position and at other positions throughout the unit cell. Excellent agreement is achieved between the measurable experimental and theoretical quantities, namely, charge and spin densities, the isomer shift, and the hyperfine field. It is shown that the earlier interpretation of neutron-diffraction data and the pressure dependence of the hyperfine field in favor of a negative polarization of the $4s$ states is not soundly based. From our consideration of the band contribution to the hyperfine field, the $4s$ electrons are found to be positively polarized.
TL;DR: Preliminary evidence suggests that this heterogenetic antigen(s) may enable the mycoplasmas to become established in their host, and indicates the occurrence of a heterogenetics antigen common to M. arthritidis and rat tissues.
Abstract: Complement fixation (CF), immunofluorescence, and agar gel double-diffusion tests were used to demonstrate an antigenic relationship between rat tissues and Mycoplasma arthritidis. Rabbit antisera against six strains of M. arthritidis exhibited positive reactions in the CF test with an ethyl alcohol-saline extract of rat muscle, whereas only 6 of 18 antisera against other Mycoplasma species were positive. With the use of gel diffusion techniques, absorption of various M. arthritidis antigens with antiserum against rat muscle removed at least one precipitin band when the absorbed mycoplasma antigens were reacted against homologous antisera. Rabbit antiserum against M. arthritidis was conjugated with fluorescein isothiocyanate and reacted against frozen sections of muscle tissues of various animals. As controls, unlabeled normal rabbit serum and rabbit anti-M. arthritidis serum were included to determine the specificity of the reaction. Rat, hamster, and mouse skeletal muscle exhibited specific fluorescence, whereas chicken, beef, frog, and turtle muscles exhibited no specific fluorescence. Mice injected at birth with rat lymphocytes were found to be more susceptible to subsequent infection by M. arthritidis than were normal mice or mice injected at birth with mouse lymphocytes. These results indicate the occurrence of a heterogenetic antigen(s) common to M. arthritidis and rat tissues. Preliminary evidence suggests that this heterogenetic antigen(s) may enable the mycoplasmas to become established in their host.
TL;DR: The motivation for preparing a special issue of Geophysics devoted to electromagnetic scattering lies largely with a sudden and dramatic improvement in the ability to model the earth in theoretical analyses of the electromagnetic exploration problem.
Abstract: The motivation for preparing a special issue of Geophysics devoted to electromagnetic scattering lies largely with a sudden and dramatic improvement in our ability to model the earth in theoretical analyses of the electromagnetic exploration problem. This improvement was in turn generated by a need for better interpretation of electromagnetic data, a need for better design of electromagnetic systems, and a need to develop better criteria for selection of electromagnetic systems suited to a given prospecting problem.
TL;DR: La décharge de fibres vagales d'origine cardiaque est augmentée au cours d'une réduction du flux sanguin dans l'artère coronaire de gauche lorsque le coeur est déjà défaillant à cause of l'ichémie.
Abstract: La decharge de fibres vagales d'origine cardiaque est augmentee au cours d'une reduction du flux sanguin dans l'artere coronaire de gauche. Toutefois cette excitation n'a lieu que lorsque le coeur est deja defaillant a cause de l'ichemie. La stimulation effective parait etre de nature mecanique.
TL;DR: The method is simple and gives reproducible, good yields, and several criteria for evaluation of its purity are presented, as well as typical amino acid composition of tropoelastin thus prepared.
TL;DR: In this article, the authors studied the relation of voluntary childlessness in a select population and found that the majority of the individuals in the selected population did not choose to have children.
Abstract: (1971). Correlates of voluntary childlessness in a select population. Social Biology: Vol. 18, No. 3, pp. 277-284.
TL;DR: In this paper, the experimental band shapes of these IR transitions with their associated zero phonon line were analyzed using a simple model for the electron coupling, and the energy positions, dichroic behavior and oscillator strengths of these transitions were found in close agreement to the calculated states of the H molecule corrected with a single dielectric constant.
Abstract: F centers in KCl crystals were so far identified by one absorption band at 1.4 μm. Several new absorption bands found in the visible and near UV are studied at LHeT with an almost perfectly aligned system. Energy positions, dichroic behavior and oscillator strengths of these transitions are found in close agreement to the calculated states of the H molecule corrected with a single dielectric constant. Excitation of the lowest excited 2pσu state at 1.4 μm leads with a temperature independent quantum efficiency to the IR emission at 1.67 μm. The experimental band shapes of these IR transitions with their associated zero phonon line were analyzed using a simple model for the electron coupling. Low temperature excitation of all higher absorption states (2pπu, etc.) produces a 600 nm luminescence. At higher temperature a thermally activated process transfers the excitation energy to the lowest excited state (2pσu) quenching the 600 nm luminescence and producing the IR emission.
Les centres F dans les cristaux de KCl etaient identifies jusqu' a maintenant par une bande d'absorption IR a 1.4 μm. Plusieurs nouvelles bandes d'absorption dans le visible et le proche UV sont etudiees a la temperature de l'He liquide avec des centres F presque completement alignes. Les positions en energie, les proprietes dichroiques, et les forces d'oscillateurs de ces transitions sont trouvees en excellent accord avec les etats calcules du ion moleculaire H, corriges a l'aide d'une constante dielectrique unique. L'excitation de l'etat excite inferieur 2pσu a 1.4 μm donne lieu a une emission IR a 1.67 μm dont l'efficacite quantique est independante de la temperature. L'allure experimentale de ces transitions IR avec leur raie zero phonon associee sont analysees a l'aide d'un modele simple pour le couplage electron phonon. A basse temperature l'excitation de tous les niveaux superieurs (2pσu, etc.) produit une luminescence a 600 nm. A plus haute temperature un processus non radiatif transfert l'energie d'excitation sur le niveau excite relaxe inferieur (2σu) “quenchant” la luminescence a 600 nm mais laissant apparaǐtre l'emission IR.
TL;DR: Significant quantities of corticosterone were associated with macromolecules of the brain cytosol following intrathecal administration of [3H]corticosterone to adrenalectomized rats and evidence for protein‐steroid interaction was obtained.
Abstract: Significant quantities of corticosterone were associated with macromolecules of the brain cytosol following intrathecal administration of [3H]corticosterone to adrenalectomized rats. Fifteen times more steroid was found associated with proteins from adrenalectomized rats than from control animals or adrenalectomized animals pretreated with corticosterone. Pretreatment of adrenalectomized rats with 11-dehydrocorticosterone, Cortisol and cortisone decreased the amount of [3H]corticosterone found associated with protein, whereas progesterone, oestradiol and testosterone did not interfere with the association of [3H]corticosterone with macromolecules of the cytosol. Further evidence for protein-steroid interaction was obtained by incubating [3H]corticosterone (B), [3H]cortisol (F), or 11-[3H]deoxycortisol (S) with brain cytosols. The degree of binding was in the order B > F > S.