Showing papers by "University of Oklahoma published in 1981"

Generation of fibrinolytic activity by infusion of activated protein C into dogs.

Abstract: A B S T R A C T Bovine-activated protein C, administered intravenously to dogs, increases the rate oflysis of whole blood clots. Protein C, bovine prothrombin, and diisopropylfluorophosphate-inactivated protein Ca do not increase the rate of lysis. Repeated infusions of protein Ca sustain rapid blood clot lysis, but neither elevate circulating fibrin-split products nor decrease circulating plasminogen levels. The administration of protein Ca results in the elevation ofthe levels oflysineadsorbable plasminogen activator activity in the plasma. When partially purified concentrates of this activator are added to normal dog blood at the levels seen following protein Ca injection, the rate ofclot lysis is similar to that seen after protein Ca injection. The addition of protein Ca to citrated whole blood in vitro, with the subsequent neutralization of protein Ca with antibodies, results in increased rates of lysis when plasma made from the treated blood is reinjected into the animal. The generation of fibrinolytic activity is dependent on both cellular and plasma components of blood. A model of protein Ca fibrinolytic activity has a minimum of two components: a secondary messenger formed by protein Ca action on blood cells and plasma, and the subsequent appearance of plasminogen activator in the animal in response to that messenger.

The pathophysiology of altered calcium metabolism in rhabdomyolysis-induced acute renal failure. Interactions of parathyroid hormone, 25-hydroxycholecalciferol, and 1,25-dihydroxycholecalciferol.

Abstract: We studied six oliguric patients with rhabdomyolysis-induced acute renal failure. On admission, all had marked hyperphosphatemia and hypocalcemia associated with low levels of 1,25-dihydroxycholecalciferol [1,25(OH)2D]. During the early polyuric phase, moderate hypercalcemia was accompanied by marked elevations in plasma 1,25(OH)2D and persistent elevations in parathyroid hormone (both amino and carboxy terminals). During the late polyuric phase, the levels of serum calcium and 1,25(OH)2D reverted to normal. Thus, in rhabdomyolysis-induced acute renal failure, the hypocalcemia of the oliguric phase may be secondary to decreased synthesis of 1,25(OH)2D; severe hyperphosphatemia may also have a major role. The hypercalcemia of the polyuric phase may be partly due to increased synthesis of 1,25(OH)2D, resulting from the high parathyroid hormone levels and recovery of renal function.

A New Definition of Learning Disabilities

Abstract: Learning disabilities is a generic term that refers to a heterogeneous group of disorders manifested by significant difficulties in the acquisition and use of listening, speaking, reading, writing, reasoning or mathematical abilities. These disorders are intrinsic to the individual and presumed to be due to central nervous system dysfunction. Even though a learning disability may occur concomitantly with other handicapping conditions (e.g., sensory impairment, mental retardation, social and emotional disturbance) or environmental influences (e.g., cultural differences, insufficient/inappropriate instruction, psychogenic factors), it is not the direct result of those conditions or influences.

The production of ethanol by immobilized yeast cells

Abstract: Saccharomyces cerevisiae cells were immobilized in calcium alginate beads for use in the continuous production of ethanol. Yeasts were grown in medium supplemented with ethanol to selectively screen for a culture which showed the greatest tolerance to ethanol inhibition. Yeast beads were produced from a yeast slurry containing 1.5% alginate (w/v) which was added as drops to a 0.05M CaCl2 solution. To determine their optimum fermentation parameters, ethanol production using glucose as a substrate was monitored in batch systems at varying physiological conditions (temperature,pH, ethanol concentration), cell densities, and gel concentrations. The data obtained were compared to optimum free cell ethanol fermentation parameters. The immobilized yeast cells were examined in a packed-bed reactor system operated under optimized parameters derived from batch-immobilized yeast cell experiments. Ethanol production rates, as well as residual sugar concentrations were monitored at different feedstock flow rates. (Refs. 13).

Distribution-system planning using mixed-integer programming

Abstract: The prime objective of the study was to develop distribution-system planning models which can be used by distribution-system planners to determine optimum expansion patterns or alternatives by selecting: optimum substation locations, i.e. sites; optimum substation expansions; optimum substation transformer sizes; optimum load transfers between substations and demand centres; and optimum feeder routes and sizes to supply the given loads, i.e. demands, subject to a number of constraints, to minimise the present worth of the total costs involved. The results indicate that the developed optimisation models can be very valuable tools in planning distribution systems

A dynamic analysis of migration: an assessment of the effects of age family and career variables

Abstract: This paper examines the utility of viewing migration in the context of work careers and family life cycles. We do this by studying migration as a discrete state, continuous time process. We find that the inverse relationship between age and migration is due almost completely to the effects of family life cycle and work career variables. Further, we find that job- or locationspecific resources, prestige and wage deter migration.

Altered sleep physiology in chronic alcoholics: reversal with abstinence.

Abstract: Somnograms obtained from recently abstinent chronic alcoholics reveal gross disruption succinctly described as "fractured" sleep. Sleep onset is delayed and the rhythmic properties of the sleep pattern are markedly disturbed with numerous brief arousals and changes of sleep stage. Excessive stage 1 and stage rapid eye movement sleep are present while the high voltage slow wave sleep is markedly reduced or absent. With continued sobriety (9 mo or more) the sleep stage percentages tend to return to normal levels, but the disruption of the sleep pattern persists after as much as 21 mo of abstinence.

A review of the fossil record of monocotyledons

Abstract: The fossil record of monocotyledons is reviewed in order to determine the families actually represented by fossils and their stratigraphic ranges. In providing this information, attention is called to deficiencies and strengths in the record. Most notable is the uneven representation of the four subclasses of monocotyledons. Three distinct phases in the history of monocots can be delineated when the record and ranges of modern families are compared with paleotemperature data. First is a phase of initial radiation and diversification primarily restricted to the Cretaceous and represented by the appearance of a variety of monocotyledonous leaf forms. Second is a phase of modernization of the monocot flora resulting from further development of preexisting Cretaceous forms during favorable climatic conditions during the latest Cretaceous and Paleogene. The third phase is one marked by changes in distributions and expansion of other groups corresponding with climatic deteriorations of the late Paleogene. Some suggestions concerning the limitations of and potential for further research into the fossil record of monocots are presented.

Prepared lies, spontaneous lies, Machiavellianism, and nonverbal communication

Abstract: This study investigated cue leakage during deception of factual information for both prepared and spontaneous types of lies. Liars anticipating lying engaged in less postural shifting and shorter latencies than truth tellers prior to lying. During a prepared lie, liars engaged in shorter latencies, shorter message durations, more affirmative head nodding, less smiling, and more body adaptors than truth tellers did. During a spontaneous lie, liars engaged in more body adaptors than truth tellers. No substantive differences were obtained between truth tellers and liars after the lying behavior was completed. Cues were not leaked differently by high and low Machiavellians.

Vapor pressure studies of hydrophobic interactions. formation of benzene-benzene and cyclohexane-cyclohexanol dimers in dilute aqueous solution

Abstract: A new, highly sensitive vapor pressure apparatus has been used to study very dilute solutions of benzene, of cyclohexane, and of mixtures of cyclohexane and cyclohexanol in water at temperatures from 15 to 45°C. The results have been used to calculate the enthalpy, free energy, and heat capacity of transfer of benzene and of cyclohexane from the vapor phase into water at infinite dilution. Values of the equilibrium constant and the enthalpy change have been determined for the reactions $$2{\text{ benzene = (benzene)}}_{\text{2}} $$ (A) and $${\text{cyclohexane + cyclohexanol = cyclohexane }} \cdot {\text{ cyclohexanol}}$$ (B) occurring in dilute aqueous solution. Of particular interest is the result that the enthalpy of dimerization is positive for the two association reactions [4.0±1.0 kcal-mol−1 for reaction (A) and 3.45±0.16 kcal-mol−1 for reaction (B) at 25°C]. The heat capacity change for reaction (B) is −61±39 cal-K−1-mol−1. The results are discussed in relation to current theories and descriptions of hydrophobic interactions.

Nitrogen Metabolism in Plants

Abstract: Although plants or plant parts can be cultured on various organic nitrogen forms, particularly amino acids, under natural conditions the majority of plants depend upon inorganic nitrogen sources. Exceptions to this may be various parasitic and semi-parasitic plants which may be provided with organic nitrogenous nutrients of host origin, and insectivorous plants which partially satisfy their nitrogen demands by utilizing organic nitrogen constituents released by lysis of trapped insects.

Prehistoric raised-field agriculture in the maya lowlands.

Abstract: The ground pattems found in Pulitrouser Swamp, northern Belize, are vestiges of raised and channelized fields, types of wetland cultivation used by the ancient Maya. This form of hydraulic cultivation was apparently employed sometime between 200 B.C. and A.D. 850. The environment of the swamp, the fields and canals, and one nearby settlement, Kokeal, are described. The evidence indicates that the large number of well-defined ground patterns reported in other areas in the central Maya lowlands are probably vestiges of Maya wetland cultivation.

Gross and microscopic anatomy of the eighth cranial nerve in relationship to the solitary schwannoma

Abstract: Surgical advances over the past two decades, allowing the discovery of smaller solitary schwannomas of the VIIIth cranial nerve and their extirpation with preservation of the VIIth cranial nerve, have lead to attempts to resect the tumor without completely resecting its nerve of origin. This paper reports the macroscopic and microscopic observations of 22 solitary schwannomas of the VIIIth cranial nerve as they relate to the nerve of origin. Nine tumors were removed, en bloc with the VIIIth nerve, transversely subserially sectioned and studied by light microscopy. Four of the en bloc cases and 13 additional cases were studied by biopsying the VIIIth nerve branches, lateral, and the VIIIth nerve trunk medial to the tumor. The results suggest that the VIIIth nerve is involved throughout the extent of the tumor and, in some cases, beyond the tumor limits with intraneural invasion by tumor cells. There is an immediate dispersion of VIIIth nerve fibers to extremely small aggregates dispersed peripherally about the tumor surface. These fiber aggregates are not surgically dissectable from the tumor because of the difficulty in identifying the fibers and because of tumor infiltration of normal appearing nerves. The pure tone threshold average of 500-2,000 Hz. tends to correlate more closely with the number of cochlear fibers present, lateral to the tumor, than do other auditory tests. The percent of unilateral vestibular weakness does not correlate with the number of fibers present in the superior vestibular nerve. In summary, these histologic data suggest that complete tumor resection from VIIIth nerve fibers may be beyond our present technological capabilities. They further suggest severe limits to accurate identification of candidates for this conservation surgery.

Metabolic abnormalities in patients supported with enteral tube feeding.

Abstract: One hundred patients supported with enteral tube feeding were evaluated for biochemical abnormalities. The following metabolic complications were observed: hyperglycemia (29%), hypoglycermia (2%) hypernatremia (10%), hyponatremia (31%), hyperkalemia (40%) hypokalemia (8%), hyperphosphatemia (14%) hypophosphatemia (30%) hypomagnesemia (3%), hypozincemia (11%), and hypocupremia (3%). Because of the extensive range of biochemical problems, it is recommended that subjects on tube feeding be evaluated periodically for metabolic abnormalities.

Persistent parainfluenza virus shedding during isolation at the South Pole.

Abstract: Persistent parainfluenza virus shedding in healthy young adults occurred throughout the 8 1/2-month winter isolation period at Amundsen-Scott South Pole Station during 1978. Two episodes of respiratory illness were observed after 10 and 29 weeks of complete social isolation. Throat swabs collected both routinely, and during each outbreak of respiratory illness, were directly inoculated into cell cultures. Parainfluenza virus types 1 and 3 were recovered from both symptomatic and asymptomatic subjects throughout the winter. No other viruses were obtained by these efforts. The presence of parainfluenza virus in these subjects long after the accepted incubation period for viral upper respiratory illness, and when the introduction of new virus to this community was impossible, suggests its persistence in man.

Thermoelasticity of circular cylindrical shells laminated of bimodulus composite materials

Abstract: Closed-form and finite-element solutions are presented for the thermoelastic behavior of laminated composite shells. The material of each layer is assumed to be thermoelastically orthotropic and bimodular, that is, having different properties depending upon whether the fiber-direction normal strain is tensile or compressive. The formulations are based on the thermoelastic generalization of Dong and Tso 's laminated shell theory, which includes thickness shear deformations. The finite element used here has five degrees of freedom per node (three displacements and two bending slopes). Numerical results are presented for deflections and the positions of the neutral surfaces associated with bending along both coordinate directions. The closed-form and finite-element results are found to be in good agreement.

Comparison of concanavalin A-reactive determinants on hemocytes of two Biomphalaria glabrata snail stocks: receptor binding and redistribution.

Abstract: Fluorescein-labeled concanavalin A (F-Con A) was employed as a membrane probe to compare the surface glycosyl components associated with glass-adherent circulating hemocytes from a schistosome-susceptible (PR albino) and schistosome-refractory (10-R2) stock of snails Biomphalaria glabrata Under hemolymph-free conditions, granular hemocytes (granulocytes), composed of two morphologically-distinct cell populations (rounded and spread hemocytes) bound F-Con A via specific carbohydrate surface receptors Con A-binding induced in rounded hemocytes a redistribution (patching and capping) of lectin-receptor complexes Receptor redistribution in both snail stocks was characterized by a high capping frequency (80–90% of adherent rounded cells) and temperature dependency Differences in the response of albino and 10-R2 snail hemocytes to differing F-Con A concentrations, however, suggest that cells may possess subtle differences in physiology or function

Vibration of Thick Rectangular Plates of Bimodulus Composite Material.

Abstract: : A finite-element analysis is carried out for small-amplitude free vibration of laminated, anisotropic, rectangular plates having arbitrary boundary conditions, finite thickness-shear moduli, rotatory inertia, and bimodulus action (different elastic properties depending upon whether the fiber-direction strain is tensile or compressive) The element has five degrees of freedom, three displacements and two slope functions, per node An exact closed-form solution is also presented for the special case of freely supported single-layer orthotropic and two-layer, cross-ply plates This provides benchmarks to evaluate the validity of the finite-element analysis Both solutions are compared with numerical results existing in the literature for special cases (all for ordinary, not bimodulus, materials) and good agreement is obtained (Author)

Validating The Retail Store Image Concept

Abstract: The perceived images of seven retail firms encompassing several lines of trade are presented in this paper. To determine these images, data on store attributes and the importance of these attributes were collected from a random sample within selected census tracts of a Southwestern city. The linear compensatory multi-attribute model approach of product attitudes was extended to that of store patronage. The ability of these image models to predict attitudes towards the retail outlets as well as patronage behavior is investigated. In addition, the power of importance weights in these models is statistically examined.