Showing papers by "University of Kentucky published in 1969"

Topological entropy bounds measure-theoretic entropy

Abstract: Let T be a homeomorphism from a compact space A onto itself and let p be a P-invariant probability measure on the Borel sets of A. It was conjectured in [l] that the measure-theoretic entropy of P with respect to u is less than or equal to the topological entropy of P. The purpose of this paper is to show, under the assumption that A is metric, that the inequality holds when T is assumed only to be a continuous map from A into itself. We shall first prove the inequality under the assumption that A is a closed subset of the Hilbert cube which is invaraint under a certain type of shift operator, and P is the restriction of the operator to A. The generalization will be obtained by considering representations of T as such shifts. By a flow we mean a pair (A, P), where A is a compact metric space and T is a continuous map from A into itself. Throughout the paper, (A, P) and (F, S) will denote arbitrary flows. A continuous map F will be called a homomorphism from (A, T) into (F, S) iid)oT = Sod>. Ii a is any finite cover of A, we let N(a) be the number of members in a subcover of a of minimal cardinality. As in [l], we write aVj8= { UCW: P£a, F£|3} and we write a>fi to mean that a is a refinement of fi, though this is contrary to the notation of many authors. As in [l], it follows from the fact that N(a\/fi) ^N(a)-N(fi), that the limit exists in the following definition:

Ultrastructure of Blue-Green Algae

Abstract: Two freshwater blue-green algae, Tolypothrix tenuis and Fremyella diplosiphon, and an oscillatorialike marine alga, were found to possess structures on the photosynthetic lamellae which appear to correspond to the phycobilisomes of red algae. These homologous structures are important because they contain the phycobilins which are accessory pigments involved in photosynthesis. As in the red algae, the phycobilisomes were attached on the outer side of each lamellae, i.e., the side facing away from its own membrane pair. Although our study on Anacystis nidulans has not thus far revealed the presence of phycobilisomes, some observations were made on the structure of the polyhedral bodies. After negative staining, the polyhedral bodies were seen to be composed of regularly spaced subunits arranged in a crystalline array. Elongated segmented rods, which differed from the polyhedral bodies, were found in the nuclear region of apparently healthy Tolypothrix cells. Images

Temperature regulation and respiration in the ostrich

Abstract: The Ostrich (Struthio camelus), the largest living bird, is an inhabitant of semi-arid and desert areas of Africa and, until exterminated, the Near East and the Arabian Peninsula. When exposed to the heat stress of a hot desert, it must use water for evaporation in order to avoid overheating. While its size prevents it from taking advantage of microclimates to the extent that small desert birds and mammals can, its large size is an advantage in its water economy, as has been discussed previously (Schmidt-Nielsen 1964). Birds have no sweat glands, and under heat stress they rely upon increased evaporation from the respiratory system as a major avenue for heat dissipation. We were interested in the role of the respiratory system in evaporation, and particularly in the sites of evaporation. Furthermore, while in mammals an increased ventilation causes alkalosis, in birds the presence of large air sacs connected to the respiratory system may have radically different effects on the gas exchange in the lung. Finally, the fact that the ventilation of the respiratory system can be modified by heat stress without change in the rate of oxygen consumption may provide an avenue for investigation of the poorly understood air-sac system of birds. The Ostrich, although a non-flying bird, has a well developed air-sac system, and its large size and slow breathing rate provide an opportunity to undertake experimental procedures which in smaller birds result in great technical difficulties or seem impossible. MATERIALS AND METHODS

Closure on vibration modulus of normally consolidated clay

Abstract: THE WRITERS ARE GRATEFUL TO WHITMAN, HOLT AND MURPHY, AND DOBRY AND POBLETE FOR DEMONSTRATING THE GOOD AGREEMENT BETWEEN VALUES OF THE SHEAR MODULUS CALCULATED IN THE PRESENTED EQUATION AND SHEAR WAVE VELOCITIES MEASURED IN THE FIELD BY GEOPHYSICAL METHODS AT TWO DIFFERENT SITES. TEST RESULTS SHOW THE EFFECT OF VOID RATIO, AMBIENT STRESS, STRESS HISTORY, FREQUENCY, AND STRAIN AMPLITUDE ON THE VIBRATION SHEAR MODULUS OF THESE UNDISTURBED SAMPLES. INDEX PROPERTIES IN THE CLASSIFICATION OF VARIOUS UNDISTURBED COHESIVE SOILS TESTED ARE PRESENTED IN A TABLE AND THEIR PARTICLE SIZE DISTRIBUTIONS SHOWN IN A FIGURE. THE VALUES OF VOID RATIO ARE PRESENTED IN A FIGURE. ANOTHER FIGURE PRESENTS THE EFFECT OF ISOTROPIC COMPONENTS OF STRESS ON UNDISTURBED SAMPLES. THE EFFECT OF OVERCONSOLIDATION RELATIONSHIPS ARE PRESENTED. WHITMAN, HOLT AND MURPHY HAVE PRESENTED A FIGURE SHOWING A CURVE BY WHICH THE MODULUS FOR HIGHER STRAIN AMPLITUDES MAY BE COMPUTED FROM THE MODULUS AT SMALL STRAIN AMPLITUDES. RESULTS ARE PRESENTED IN A FIGURE OF (1) COHESIVE SOIL AND (2) DRY SANDS WHICH WERE TESTED AT DIFFERENT FREQUENCIES AND NUMBERS OF CYCLES. DATA FOR BOTH HOLLOW AND SOLID CYLINDRICAL SPECIMENS SHOWED THE EFFECT OF THE VARIATION OF STRAIN WITHIN THE SPECIMEN TO BE SMALL. THIS IS ALSO TRUE FOR LARGE STRAIN AMPLITUDES PROVIDED THE MEASURED PARAMETERS ARE CORRELATED TO THE AVERAGE SHEAR STRAIN AMPLITUDE IN THE SPECIMEN. THE RESULTS FOR TWO SENSITIVE CLAYS ARE SHOWN IN A FIGURE. THE SPECIAL STRUCTURE OF HIGHLY SENSITIVE CLAYS APPEARS TO INCREASE THE MODULUS ABOVE THAT FOR LESS SENSITIVE SOILS WITH SIMILAR VOID RATIO AND STATE OF STRESS. REFERENCES: VIBRATION MODULUS OF NORMALLY CONSOLIDATED CLAY, BOBBY O. HARDIN, WILLIAM L. BLACK, ASCE PROCEEDINGS PAPER 5833, MARCH, 1968.

Verrucous squamous cell carcinoma of the oral cavity

Abstract: Verrucous-type oral tumors have been reviewed. This variety of epidermoid carcinoma of the oral cavity presents as a warty growth in patients who have a history of chewing tobacco and poor oral hygiene. They are slow-growing, locally invasive, and do not metastasize to lymph nodes in our experience. In five of these patients, the microscopic pattern was that of a well-differentiated squamous cell carcinoma. The others presented the classical histologic pattern of verrucous carcinoma. No difference was found in the behavior of these two groups. Three cases developed anaplastic transformation after irradiation and surgery. A change in the clinical behavior of the tumor was observed in these patients and all three died. There is some possibility that ionizing radiations could be the trigger mechanism in this transformation. The authors feel that surgery is the treatment of choice in early or easily resectable lesions. It would appear unnecessary to perform neck dissection in these patients. Radiation therapy should be used in advanced verrucal-type lesions in which surgical resection is difficult or not feasible. These patients require frequent and careful observation. The authors believe that this entity deserves further investigation.

Utility of expressing serum sodium per unit of water in assessing hyponatremia

Abstract: Total protein and total lipid are the major components of the total solids of serum and they displace the water and sodium of serum. To differentiate the spurious hyponatremias, caused by hyperproteinemia and hyperlipidemia, from the true hyponatremias, a knowledge of whether or not the percentage of water in serum is essentially normal is required. To determine serum water concentration indirectly, a simple modification of a standard formula is proposed, utilizing both total serum protein and total serum lipid measurements. This can be used to relate or correct serum sodium concentration in mEq./liter of serum to mEq./liter of serum water. Generally available chemical methods to determine total serum protein and total serum lipid concentrations can be used to estimate serum water content by a general formula. Refractive index and specific gravity methods to determine serum protein and water content may be invalid in hyperlipidemia.

Worry and emotionality as components of test anxiety: replication and further data.

Abstract: Two components of test anxiety, worry (W) or cognitive concern about performance and emotionality (E) or autonomic arousal to the test situation, were examined in relation to temporal changes, expe...

A comparison of LSD-25 with (−)-Δ9-trans-tetrahydrocannabinol (THC) and attempted cross tolerance between LSD and THC

Abstract: 1. The objective and subjective effects of 0.5 and 1.5 mcg/kg of LSD intramuscularly were compared with those of 75 and 225 mcg/kg of (-)-Δ9-trans-tetrahydrocannabinol by smoking in the same eight subjects. 2. The objective effects of LSD and THC differed markedly. LSD increased body temperature, systolic and diastolic blood pressure, lowered the threshold for the knee-jerk, and dilated the pupils. THC had none of these effects but caused more marked tachycardia than did LSD. 3. The subjective effects of the two drugs could not be readily distinguished by the methods used. Both LSD and THC are psychotomimetic drugs. 4. Patients tolerant to LSD were not cross-tolerant to THC, indicating that the mental effects of the two drugs are probably mediated by different mechanisms.

Phospholipid Metabolism in Ferrobacillus ferrooxidans

Abstract: The lipid composition of the chemoautotroph Ferrobacillus ferrooxidans has been examined. Fatty acids represent 2% of the dry weight of the cells and 86% of the total are extractable with organic solvents. About 25% of the total fatty acids are associated with diacyl phospholipids. Polar carotenoids, the benzoquinone coenzyme Q-8, and most of the fatty acids are present in the neutral lipids. The phospholipids have been identified as phosphatidyl monomethylethanolamine (42%), phosphatidyl glycerol (23%), phosphatidyl ethanolamine (20%), cardiolipin (13%), phosphatidyl choline (1.5%), and phosphatidyl dimethylethanolamine (1%) by chromatography of the diacyl lipids, by chromatography in four systems of the glycerol phosphate esters derived from the lipids by mild alkaline methanolysis, and by chromatographic identification of the products of acid hydrolysis of the esters. No trace of phosphatidylserine (PS), glycerolphosphorylserine, or serine could be detected in the lipid extract or in derivatives of that extract. This casts some doubt on the postulated involvement of PS in iron metabolism. After growth in the presence of 14C and 32P, there was essentially no difference in the turnover of either isotope in the glycerolphosphate ester derived from each lipid in cells grown at pH 1.5 or 3.5.

Germination of Single Bacterial Spores

Abstract: Changes in refractility and optical density occurring in individual spores of Bacillus cereus T and B. megaterium QM B1551 during germination were investigated by use of a Zeiss microscope photometer. The curves revealed that the germination process in single spores had two distinct phases; an initial rapid phase was followed by a second slower phase. Under the experimental condition employed, the first phase of germination of B. cereus spores lasted for approximately 75 +/- 15 sec, whereas the second phase lasted for 3 to 4.5 min. In B. megaterium spores, the first phase was observed to last for approximately 2 min and the second phase for more than 7 min. The duration of the second phase was dependent on conditions employed for germination. The kinetics of the first phase were strikingly similar under all conditions of physiological germination. Time-lapse phase-contrast microscopy of germinating spores also revealed the biphasic nature of germination. It was postulated that the first phase represents changes induced by an initial partial hydration of the spore and release into the medium of dipicolinic acid, whereas the second phase reflects degradation of the cortex and hydration of the core.

Standardized Global Advertising, a Call as Yet Unanswered

Abstract: A number of advertising spokesmen have strongly recommended a truly “international” approach to advertising for firms operating outside the United States. This article describes how U.S. internatio...

Influence of repetitive dosing of tetracyclines on biologic half-life in serum.

Abstract: The apparent biologic half‐lives of tetracycline, demethylchlortetracycline, methacycline, and doxycycline were found to increase from 6.3, 11, 7, and 8.3 hours to 10, 14.7, 11, and 14.5 hours, respectively, during 4 days of repetitive dosing (every 12 hours). Steady‐state serum levels predicted mathematically on the basis of the latter biologic half‐lives agreed with those observed experimentally, whereas steady‐state serum levels predicted on the basis of the biologic half‐life calculated from single‐dose studies did not. A method was developed for estimating the biologic half‐life from steady‐state serum level data; these estimates agreed well with the biologic half‐life estimated from semilogarithmic plots of serum level versus time data during the steady state and after dosing had ceased. Capsules of tetracycline phosphate complex, tablets of demethylchlortetracycline hydrochloride, capsules of methacycline hydrochloride, and capsules of doxycycline hyclate were found to produce comparable serum levels of antibiotic activity when administered at recommended doses every 12 hours.

Studies on Polyphenol Content, Activities and Isozymes of Polyphenol Oxidase and Peroxidase During Air-Curing in Three Tobacco Types

Abstract: The change in polyphenol content in the primed leaves of burley, flue-cured, and Turkish tobaccos during air-curing was related to the activities and isozymes of polyphenol oxidase and peroxidase. The quantity of chlorogenic acid was rapidly reduced during the first week of curing. The decrease in rutin content during curing was less significant, especially when the concentration of chlorogenic acid was high in leaf tissues. This result was further confirmed by in vitro assays with partially purified tobacco polyphenol oxidase.The polyphenol oxidase activity did not differ at any stage of curing in the 3 tobaccos. When the activity was measured by the oxidation of 3,4-dihydroxyphenylalanine it rose rapidly during the first day of curing and then decreased sharply so that in the fully cured leaf only 15% activity remained. The increase in activity was not observed when chlorogenic acid was used as the substrate. A similar level of peroxidase activity was found in the 3 tobaccos before curing. Peroxidase activities increased rapidly during the first 24 hr of curing, declined thereafter, and remained highest in the flue-cured tobacco, less in the Turkish line, and least in the burley at the end of curing process.By polyacrylamide gel block electrophoresis, 10 peroxidase isozyme bands, 2 cationic and 8 anionic, appeared identical in all 3 tobaccos. When catechol replaced benzidine-2 HCl as the electron donor, 1 cationic and 2 anionic peroxidase isozymes did not form. Of interest is that the same 10 peroxidase isozyme bands also exhibited polyphenol oxidase activities when treated with 3,4-dihydroxyphenylalanine or chlorogenic acid. Results suggest that in the crude tobacco leaf extract the peroxidase and polyphenol oxidase may associate as protein complexes, and peroxidase isozymes may differ in electron-donor requirements. Isozyme patterns for both oxidases at various curing intervals differed only quantitatively.

Microgermination of Bacillus cereus Spores

Abstract: The biphasic nature of germination curves of individual Bacillus cereus T spores was further characterized by assessing the effects of temperature, concentration of germinants, and some inorganic cations on microgermination. Temperature was shown to affect both phases of microgermination as well as the microlag period, whereas the concentration of l-alanine and supplementation with adenosine exerted a significant effect only on the microlag period. The germination curves of individual spores induced by inosine were also biphasic and resembled those of spores induced by l-alanine. High concentrations (0.1 m or higher) of calcium and other inorganic cations prolonged both phases of microgermination, particularly the second phase, and had a less pronounced effect on the microlag period. The second phase of microgermination was completely inhibited when spores were germinated either in the presence of 0.3 m CaCl(2) or at a temperature of 43 C; this inhibition was reversible. Observations on the germination of spore suspensions (kinetics of the release of dipicolinic acid and mucopeptides, loss of heat resistance, increase in stainability, decrease in turbidity and refractility) were interpreted on the basis of the biphasic nature of microgermination. Dye uptake by individual spores during germination appeared also to be a biphasic process.

Differenzierung zwischen aktiver und passiver Komponente desd-Glucosetransports am proximalen Konvolut der Rattenniere

Abstract: Der Nettotransport und der unidirektionale Transport vond-Glucose wurden in Mikroperfusionsversuchen am proximalen Konvolut der Rattenniere unter der Bedingung des fehlenden Nettoflusses von Natriumchlorid und Wasser gemessen. Nach vollstandiger Hemmung des aktiven Transportanteils durch Phlorrhizin (10−4 mol/l in der Perfusionslosung) last sich eine passive Komponente desd-Glucosetransports nachweisen. Diese ist als additives Glied zum aktiven Transportanteil auch im nicht phlorrhizin-vergifteten Zustand zu beobachten. Der aktive Transportanteil betragt imV max Bereich 6·10−10 mol·cm−2·sec−1. Die passive Transportkomponente ist derd-Glucosekonzentrationsdifferenz zwischen Perfusat und Serum im angewandten Konzentrationsbereich direkt proportional. Zwischen den Ergebnissen der Ein- und Ausstrommessung besteht kein signifikanter Unterschied. Es wird daraus geschlossen, das der passived-Glucoseflus ein einfacher Diffusionsprozes ist. Der sich aus drei verschiedenen Versuchsanordnungen ergebende mittlere Permeabilitatskoeffizient der proximalen Tubuluswand fur Glucose betragt 1,7·10−5 cm ·sec−1. Es ist experimentell moglich, den aktiven Austransport durch passiven Einwartstransport vollstandig zu kompensieren. Dazu ist allerdings eine Konzentrationsdifferenz von 33 mmol/l notig. Wird der unidirektionale Austransport mit Hilfe von14C markierter Glucose gemessen, der Nettotransport jedoch chemisch, so kann man die experimentell gemessene Anderung der spezifischen Aktivitat mit den aus der Zweikomponentenhypothese (aktiver Transport + passive Diffusion) voraussagbaren Veranderungen vergleichen. Eine Ubereinstimmung von Voraussage und Befund ist bei Benutzung der oben angefuhrten Werte gegeben. Unter normalen Freiflusbedingungen spielt die passive Transportkomponente keine wesentliche Rolle. Nur bei groseren transtubularen Konzentrationsdifferenzen — wie sie bei niedrigem Glomerulumfiltrat und hoher Serumglucosekonzentration auftreten — wird der passive Glucoseeinstrom fur died-Glucoseresorption der Gesamtniere bedeutend.

The Spanish Revolution

Abstract: The difficult tune of trial which the workers and peasants revolutionary impetus is passing through imposes upon us a primary duty: that duty is to face the facts. The military fascists will not be able to gain even insignificant victories, once we realise that we have taken up our arms not merely to call a halt to fascism but to prevent it from ever again constituting a menace to the cause of the ivorkers emancipation, and that we must crush it and put it to rout once and for all though the triumph of the proletarian revolution. So long as the revolution goes on triumphantly day by day, fascism cannot triumph. The revolution demands heroism, a spirit of sacrifice, class-co7iscious?iess. Only by maintaining the revolutionary morale of the workers, not by usaless words, but by the unanswerable force of deeds, will we be able to add to the cry of ((fascism shall not pass» the more effective reality of «we shall pass over fascisms. To conquer, fascism will go to the most barbarous extremes. But when we take into account the monstrous means to which the fascists have recourse, even when they are making war between themselves, we cannot be surprised that such proceedings are carried to their very limits when it is a question of strangling the revolution. But if all the workers organisations will iccrk together, ice will make fascism retreat to where the peninsula meets the sea. In the cause, we find ourselves in complete agreement with the ((professed aims» both of the recent governmental reforms in Catalonia and the new military measure looking towards a unified command and a more effective army: but this army must be the Red Army of the workers. Revolutionaries are not mercenaries; they are the autonomous heroes of the proletarian revolution. Without damaging the perfect right of everyone to express his political opinion and social ideas, it is neccesary to keep the strictest discipline in the military sense and to carry out to the letter all orders coining from the unified command. From every conibattant must be exacted unshakable revolutionary conscience and self-denial. But i]f it is neccessary to abolish the Antifascist Militia Committee in order to avoid the dangers of dual power after its mission is accomplished, it is not neccessary to recreate the army of the state, the tool of government, capable one day of being used against the people and against the cause for which we are struggling and daily offering our lives. We object to the present measures which create an army other than the Red Army. The combattants of the revolution must not be the headless automatons who so efficiently click their heels and do and die for Hitler and Mussolini. They .•crkers, f i g h t i n g under a coordincapable of winning the war of every political party's comand the tightening of discipline cdel of Trotsky's army. When Lenin in Russia -asked Leon Trotsky to take over the War Commissariat; the bulshevick situation was desperate. They scarcely even had under their control the territory lying between Moscow and Petrograd. There were counter-revolutionary governments in the north, menancing the old capital. In Archangel, the Ukraine, Siberia and the Caucasus, the «white» troops were advancing on Moscow irresistibly; they could count en the support of the whole of imperialist officialdom. France, England, Japan and the United States gave them war material

Brain tumor chemotherapy with intrathecal methotrexate.

Abstract: Two patients harboring recurrent posterior fossa tumors were treated with intrathecal methotrexate. The patient with an ependymoma responded dramatically and, when he died of a leukoencephalopathy 2 years later, no evidence of intracranial tumor remained. A medulloblastoma in the second patient responded to methotrexate but became moderately drug resistant and spread to bone. In this case, concomitant use of intrathecal methotrexate and systemic citrovorum factor offered no apparent advantage. Relevant literature relating to methotrexate and tumor kinetics is reviewed. In the light of present knowledge, brain tumors selected for intrathecal methotrexate should be treated weekly for an indefinite period of time. The need for additional information regarding the behavior of citrovorum factor in the central nervous system is acknowledged.