Showing papers by "University of Kentucky published in 1968"

Vibration Modulus of Normally Consolidated Clay

Abstract: The resonant-column technique was used to measure the vibration shear modulus of a normally consolidated kaolinite under various anisotropic states of stress. The effects of the deviatoric and isotropic components of stress, void ratio, and other secondary effects are studied. Data from these tests along with other previously published test results for other clays with different structures lead to the following conclusions: (1) The vibration shear modulus is independent of the deviatoric component of ambient stress (octahedral shear stress); (2) the vibration shear modulus decreases with increasing void ratio and Eq. 4 in the paper is a fair representation of the effect of void ratio; the effects of structure seem to be mostly accounted for by the void ratio parameter; (3) considering the isotropic component of ambient effective stress (effective octahedral normal stress), σ¯ 0 , as an independent variable, and not including the effects of void ratio and secondary time effects, the vibration shear modulus varies with σ¯ 0 to the 0.5 power; and (4) there is a secondary increase of the vibration shear modulus with time, at constant effective stress, not accounted for by changes in void ratio. This stiffness build-up is sensitive to particle disturbance and can be partially or totally destroyed by changes in effective stress. This effect may be quite important for soils in situ.

Cave Ecology and the Evolution of Troglobites

Abstract: Obligatory cavernicoles, or troglobites, have traditionally been of special interest to evolutionary biologists for several reasons. The existence of animal life in caves and other subterranean spaces at first attracted attention because of its novelty; intensive biological exploration of caves began little more than a century ago. Although the discovery and description of the cave faunas of the world is far from complete, especially in the Western Hemisphere, so much descriptive information has been compiled that we can safely assert that, at least in unglaciated, temperate parts of the world, the occurrence of numerous species of troglobites in any major limestone region is a common and highly probable phenomenon.

Oxygen Consumption and Respiratory Evaporation of the Emu and Rhea

Abstract: with units as in equation 3. Although the data in equation (4) represent 58 species, only the Ostrich and Cassowary weighed more than 10 kg. Equation (4) is statistically indistinguishable from a comparable equation presented by King and Farner (1961) for birds weighing 0.125-10.0 kg. The relation between avian evaporative water loss and body weight conforms to a pattern similar to that for metabolism and body weight. Bartholomew and Dawson (1953) presented data for avian species ranging from 10.8 to 147 g, showing that evaporative water loss per unit weight is inversely related to body weight. Crawford (1965) proposed a tentative equation relating these variables in birds:

Chemical and Hydrologic Factors in the Excavation of Limestone Caves

Abstract: Various hydrologic and chemical processes have been investigated in an attempt to explain the development of caves in the region just beneath the water table (shallow-phreatic zone). Special attention was paid to the differences between the Darcy flow of granular aquifers and the laminar or turbulent flow of limestone aquifers, and to the ways in which water in the limestone aquifer may become undersaturated with respect to calcite. The pattern of flow in a limestone aquifer, although dependent on the boundary conditions, is similar under Darcy, laminar, or turbulent flow, provided the aquifer is wide relative to its depth and the permeability distribution is homogeneous. Although the vadose water which supplies an aquifer is often saturated or supersaturated with respect to calcite, such water may become undersaturated by being cooled or by being mixed with water which is in equilibrium with a lower P co 2 . The water of surface streams may be undersaturated with respect to calcite and may enter the aquifer by capture or by backflooding from effluent streams. The supply of vadose water to a limestone aquifer is commonly irregular. In an area where no water crosses the water table, flow in the aquifer will be nearly horizontal and water from sources adjacent to the area will follow shallow flow-paths. If such water is undersaturated with respect to calcite, caves will be excavated. Mammoth Cave, Kentucky, was probably formed by undersaturated water spilling from an impermeable bed. After reaching the water table, this water followed shallow-phreatic paths in the area beneath the impermeable bed. Backflooding from the Green River may have aided in the excavation of the cave.

Mitotic synchrony in mammalian cells treated with nitrous oxide at high pressure.

Abstract: Mammalian cells grown in suspension or monolayer cultures were synchronized for cell division by the application of nitrous oxide under pressure. The metaphase block induced by nitrous oxide was dependent on pressure and was reversible. Exposure of HeLa cells to nitrous oxide had no significant effect on the synthesis of DNA, RNA, or protein. The progress of cells through the mitotic cycle was also unaffected. A high degree of mitotic synchrony was obtained in suspension cultures of HeLa cells treated with thymidine during exponential growth, resuspended in fresh medium, and then exposed to nitrous oxide.

The Malevolent Leader: Political Socialization in an American Sub-Culture

Abstract: Perhaps the most dramatic finding of recent research on the political socialization of children is that youngsters appear to be overwhelmingly favorably disposed toward political objects which cross their vision Officers and institutions of government are regarded as benevolent, worthy, competent, serving and powerful The implications of such findings are striking indeed Childhood political dispositions may represent the roots of later patriotism; we may be observing the building of basic regime-level supportive values at a very young age These findings are by no means new; in fact, they might be classified as part of the conventional wisdom of the discipline Moreover, they are extremely well documented, and the study of childhood political socialization has advanced to consider far more than basic regime-level norms Despite all this, however, there are still many empirical questions to be asked about such norms Perhaps the recent assertion that the political scientist's model of socialization is “static and homogeneous” is particularly apropos here Consider two closely related characteristics of the appropriate literature: 1) the “positive image” which children have about politics and political figures has been synthesized from data gathered largely in the United States and to some extent in urban, industrialized communities within the United States; and 2) empirical explanation of the favorable disposition which children manifest has not progressed very far Though there may be hypotheses about how children get this way, there has been little systematic testing of the relationships between variables

Effect of Sterols on the Permeability of Alcohol-Treated Red Beet Tissue

Abstract: Alcohols and hydrogen peroxide altered the permeability of membranes of Beta vulgaris root cells. Generally alcohols increased the permeability of membranes without going through an induction period except methanol which required a 10- to 15-hour induction period. The membrane effect of methanol could be inhibited with CaCl(2), cholesterol, beta-sitosterol, and stigmasterol. Cholesterol was the most effective inhibitor, followed by beta-sitosterol and stigmasterol; and at the same concentration, the sterols were more effective than CaCl(2), the classic membrane stabilizer.Ergosterol increased the methanol-initiated betacyanin leakage. Since none of the tested sterols reversed the betacyanin efflux induced by hydrogen peroxide, the sterols do not apparently act as antioxidants. The results are explained in terms of sterol-phospholipid interaction, based on stereochemistry and charge distribution.

Electron Microscopic Observations on the Penetration of Bdellovibrio bacteriovorus into Gram-negative Bacterial Hosts

Abstract: The progressive stages in Bdellovibrio bacteriovorus penetration into two strains of Escherichia coli were examined by use of electron microscopic techniques. The initial change observed in the ultrastructure of the host following parasitic attack was the swelling of the cell envelope at the site of attachment. The Bdellovibrio then appeared to pierce the center of this swelling, forming a pore in the outer wall layers of the host. The edges of this entry pore constricted the Bdellovibrio throughout its penetration into the host cell. Although partial disruption of the cytoplasmic membrane was always apparent, the parasite did not appear to actively penetrate through this barrier. An attempt is made to correlate the fine structural changes involved in penetration with the physiological data that have accumulated to date. Images

Patterns of Panting and Gular Flutter in Cormorants, Pelicans, Owls, and Doves

Abstract: Most birds pant when subjected to heat stress, but some supplement evaporation from the respiratory tract by fluttering the gular area. Gular flutter occurs in at least the following taxa: cormorants, pelicans, boobies, anhingas, frigate-birds, herons, owls, doves, roadrunners, colies, and many gallinaceous species. The mechanics of gular flutter have been examined only in the Poor-will, Phalaenoptilus nuttallii (Lasiewski and Bartholomew 1966), but data on rates of gular flutter are available for a number of species, including the Common Nighthawk, Chordeiles minor (Lasiewski and Dawson 1964), Domestic Pigeon (Columba livia (Calder and Schmidt-Nielsen 1966), Bobwhite (Colinus virginianus), Gambel's and California Quail (Lophortyx gambelii and L. californicus), Painted Quail, Excalfactoria chinensis, Screech Owl, Otus asio, and Mourning Dove, Zenaidura macroura (Lasiewski et al. 1966b). The ability of birds that employ gular flutter to dissipate all of their metabolic heat through evaporation has been demonstrated in the Poor-will (Bartholomew et al. 1962), Common Nighthawk (Lasiewski and Dawson 1964), Domestic Pigeon (Calder and Schmidt-Nielsen 1966), Inca Dove, Scardafella inca (MacMillen and Trost 1967), and the Painted Quail (Lasiewski et al. 1966a). In caprimulgids the rate of flutter is independent of heat load and appears to be determined by the resonant properties of the gular area, just as the panting rate of dogs is determined by the resonant properties of the thoraco-abdominal region (Crawford 1962). The present study was undertaken to examine aspects of gular flutter and breathing in several birds of widely differing morphology and behavior. Through the cooperation of the staff of the San Diego Zoological Gardens, we were able to make measurements on a Double-crested Cormorant (Phalacrocorax auritus), a Brown Pelican (Pelecanus occidentalis), a Homed Owl (Bubo virginianus), and a Barn Owl (Tyto alba). Mourning doves (Zenaidura macroura) and a Horned Owl were studied on the Los Angeles Campus of the University of California.

Ultrastructure of porphyridium aerugineum a blue-green colored rhodophytan(1,2,3) .

Abstract: The ulstrastructural study on Porphyridium aerugineum showed vesicles in the peripheral cytoplasm which contain fibrous material similar in appearance to the cell sheath. In most respects the morphology of P. aerugineum, a freshwater form, is very similar to that of P. cruenturn, a marine species. However, there is a marked difference in the shape of the phycobilisomes which are attached to the chloroplast lamellae. In P. cruentum the phycobilisomes are always spherical or oblate, whereas in P. aerugineum they are disk shaped. The possibility is considered that the shape of the phycobilisomes may be determined by the phycoerythrin and phycocyanin content.

Effects of Low and High Concentrations of Potassium on the Simultaneously Recorded Purkinje and Ventricular Action Potentials of the Perfused Pig Moderator Band

Abstract: The use of the perfused pig moderator band has allowed us to study the rapid simultaneous changes in Purkinje and ventricular action potentials induced by perfusing solutions of high (10 to 12 mM) and low (0.6 to 0.8 mM) K concentrations. High K shortened the plateau more in Purkinje fibers than in ventricular fibers and decreased the difference between the action potential durations of the two fiber types. Low K prolonged the plateau in Purkinje fibers but shortened it in ventricular fibers and increased the difference between the action potential durations. Low K initially hyperpolarized both Purkinje and ventricular fibers. However, the resting potential of the Purkinje fiber subsequently decreased as phase-4 depolarization increased. The decreased maximum repolarization potential associated with low K-induced pacemaker activity was time rather than voltage dependent. When the perfusate was changed from low K to control (K = 4.8 mM), phase-4 depolarization was rapidly suppressed and the action potential of the Purkinje fiber was shortened to less than that produced by high K, and then changes in amplitude of the resting and action potentials occurred. Our observations help to explain some of the effects of low and high K on rhythm and conduction.

Healing after exposure of periosteum on the alveolar process.

Abstract: T H E GINGIVAL GIANT C E L L GRANULOMA, HLSTOCHEMICAL OBSERVATIONS Shklar, G. and Cataldo, E. J.A.S.P. 5:303-307, November-December, 1967 Ten gingival giant cell lesions were studied for the following histochemical observations: (1) RNA: moderate amounts of RNA were found in the lower layers of the stratified squamous epithelium and in the giant cells of the granuloma, (2) Metachromia: metachromasia was not observed in the giant cell lesions, (3) Tyrosine: the epithelium and the stratum corneum were lightly and moderately reactive whereas the giant cell lesion was irregularly reactive, (4) Tryptophan: epithelium and the giant cell lesion were non-reactive, (5) Sulfhydryl Groups: epithelium was non-reactive except for the stratum corneum and the giant cell lesion was lightly reactive, and (6) Acid Mucopolysaccharides: with alcian blue there was light reactivity within the giant cell lesion as well as in the lower layers of the epithelium, although most giant cells were non-reactive for acid mucopolysaccharides. Distinct differences were observed in different multinucleated giant cells in studies of tyrosine and sulfhydryl distribution. Some giant cells were essentially nonreactive, while others were moderately or even strongly reactive. Department of Oral Pathology, Tufts University, School of Dental Medicine, Boston, Massachusetts. THE EFFECT OF HYPERVITAMINOSE D ON THE PERIODONTAL MEMBRANE COLLAGEN IN LATHYRITIC RATS Shoshan, S., Pisanti, S. and Sciaky, I. J. Periodont. Res. 2:121-126, 1967 This study was conceived to investigate whether or not incompletely crosslinked collagen may serve as the site of predilection for calcification in hypervitaminosis D. Toxic doses of vitamin D2 were administered to lathyritic rats which received amino-acetonitrile in drinking water for 15 days. The normal control group received neither the lathyrogen nor toxic doses of vitamin D2. The periodontal ligament of the molars was studied both histologically and biochemically. The periodontal collagen of the lathyritic animals could be extracted with cold 0.15 M NaCl, while that of the normal controls, or of the animals which received either the vitamin alone or both the lathyrogen and the vitamin, was not extractable. Ossification of the periodontal connective tissue was apparent in the lathyritic group which received toxic doses of the vitamin but not in either lathyrism or hypervitaminosis alone. It is concluded that whereas the release of calcium from bone or the increased absorption of the mineral from the intestine is affected by vitamin D2 its deposition in the soft connective tissues may depend on the nature of the protein matrix. Incompletely crosslinked collagen, as in lathyrism, apparently serves as a cation acceptor, thus contributing to the re-establishment of the calcium balance which was disturbed during hypervitaminosis D. Connective Tissue Research Laboratory, Department of Oral Diagnosis and Oral Medicine, Hebrew University, Faculty of Dental Medicine, Jerusalem, Israel. A C U T E INFECTIOUS ORAL NECROSIS A M O N G YOUNG CHILDREN IN THE GAMBIA, WEST-AFRICA Malberger, E. J. Periodont. Res. 2:154-162, 1967 Fifty cases of acute necrotizing disease in children between the ages of 1 to 6 were observed during a 13 month period at the Royal Victoria Hospital, Bathurst, Gambia. The acute infection started as necrosis and ulceration of the interdental papillae and marginal gingiva, forming the characteristic punched-out areas. In the severe cases the attached gingiva became involved with subsequent denudation and sequestration of bone. The final stage was frequently a fulminating necrosis with oro-facial destruction causing a high incidence of death. The disease intensity was inversely related to the child's age. Local factors believed to be related to the acute infection were seen in 361 children in four neighboring Gambian villages. They were poor oral hygiene, gingivitis, food debris in various amounts and chronic periodontal disease. Bacterial smears showed a high incidence of Vincent's organisms. Systemic factors associated with the acute infection were improper nutrition, debilitation, and lowered resistance brought about by endemic infectious diseases. The H. M. Seldin Center for Oral and Maxillo-Facial Surgery and Institute of Pathology, Rambam Government Hospital, Haifa, Israel. TISSUE REACTIONS IN THE ORAL MUCOSA TO CATGUT, SILK, AND MERSILENE SUTURES Bergenholtz, A. and Isaksson, B. Odont. Revy 18:237-250, #3, 1967 Tissue reactions to catgut, silk, and mersilene were studied clinically and histologically after suturing in the oral mucosa of three dogs, using atraumatic needles. Six sutures were placed in similar positions and depth in each quadrant at intervals for clinical and histologic examination after 1, 3, 5, and 10 days. The tissue around the sutures was excised, fixed, stained and examined histologically. After 10 weeks the procedure was repeated. In all, 144 sutures were placed, 43 were lost and 85 sections examined. Leukocytic infiltration around the sutures were graded 0-3. Results showed that a large proportion of catgut sutures were lost, and these were thus considered inferior to both other materials. There were no major differences between silk and mersilene, but the latter was considered slightly superior. Departments of Oral Surgery and Paradontology, University of Umeâ, Sweden.

Monophasic Action Potentials in Man

Abstract: Monophasic action potentials with an amplitude of up to 70 mv were recorded with suction electrodes from the endocardial surface of the right atrium and both ventricles during diagnostic cardiac catheterization. The method was simple and safe. The monophasic action potential of human beings had the same shape and the same relation to the electrocardiogram as the transmembrane action potential of animals has. Also changes in heart rate and administration of calcium and digitalis had the same effect on the monophasic action potential of man as on the transmembrane action potential of animals. When injections of contrast material into the coronary arteries produced T-wave changes, the monophasic action potential from the ventricle perfused by the contrast medium lengthened, but the monophasic action potential from the other ventricle did not change. Our study suggests that the monophasic action potential may be helpful in estimating the refractory period at the site of recording and in explaining the pathoge...

Fatty acid composition of the complex lipids of Staphylococcus aureus during the formation of the membrane-bound electron transport system.

Abstract: In Staphylococcus aureus, 64 fatty acids could be separated by gas-liquid chromatography. The fatty acids consisted of normal, iso, and anteiso saturated fatty acids of from 10 to 21 carbon atoms. Of the total fatty acids, 2 to 4% were normal, iso, and anteiso monoenoic fatty acids. Positional isomers of the normal monoenoic fatty acids could be detected. The fatty acids could be extracted, leaving 1 to 2% of the total fatty acids in the residue. The proportions of the fatty acids in the residue and the total lipids differed significantly. The lipid extract contained less than 0.12% free fatty acid. Between 5 and 10% of the lipid fatty acids were associated with neutral lipids. The majority of the fatty acids were associated with the complex lipids: mono- and diglucosyl diglyceride, phosphatidyl glycerol, lysyl phosphatidyl glycerol, and cardiolipin. The proportions of the fatty acids changed markedly between bacteria grown anaerobically (no membrane-bound electron transport system) and those grown aerobically (containing a functional electron transport system). In each of the complex lipids, the proportions of the fatty acids, as well as the magnitude and direction of change in the molar quantity of the fatty acids per bacterium, changed dramatically between these growth conditions. Since the glucosyl diglycerides and phospholipids were formed from the same pool of diglyceride intermediates, the marked differences in fatty acids indicate that acyl transferase activities must be an important part of complex lipid metabolism in S. aureus.

Healing after Partial Denudation of the Alveolar Process

Abstract: W H I T E S P O N G E N E V U S I N T H E O R A L R E G I O N S Gardner, A . F . J. Pros. Dent. 18:39-45, July 1967 A review of the literature revealed 28 previously reported cases of white sponge nevus of the oral mucosa, which showed various clinical appearances. The reported lesions showed familial incidences and the histopathology revealed hyperplasia, acanthosis dyskeratosis, fusion and elongation of rete pegs, intact basement membrane, and no inflammation. Two unrelated patients that were reported in this article and the 28 reported in the literature were identical histopathologically although different clinical criteria was represented. Division of Drug Surveillance, Bureau of Medicine, Food and Drug Administration, Department of Health, Education, and Welfare, Washington, D.C. T H E E F F E C T O F C R O W N M A R G I N A L D E P T H U P O N G I N G I V A L T I S S U E Marcum, J. S. J. Pros. Dent. 17:479-487, May 1967 A total of 600 histological slides were made of 66 gold crowns that were finished above and below and even with the gingival crests in six dogs that were sacrificed at time intervals of 1, 2, and 3 months. Crowns that were even with the gingival crest caused the least inflammatory response, while the crowns with margins above or below the crest caused the most severe inflammatory process no matter how long the restoration was left in place. Evaluation of the patient relative to periodontal health, caries susceptibility and other factors is significant in the selection of crown marginal depth. University of Louisville, School of Dentistry, Louisville, Kentucky.

Lipid composition of the electron transport membrane of Haemophilus parainfluenzae.

Abstract: The principal lipids associated with the electron transport membrane of Haemophilus parainfluenzae are phosphatidylethanolamine (78%), phosphatidylmonomethylethanolamine (0.4%), phosphatidylglycerol (18%), phosphatidylcholine (0.4%), phosphatidylserine (0.4%), phosphatidic acid (0.2%), and cardiolipin (3.0%). Phospholipids account for 98.4% of the extractible fatty acids. There are no glycolipids, plasmalogens, alkyl ethers, or lipo amino acid esters in the membrane lipids. Glycerol phosphate esters derived from the phospholipids by mild alkaline methanolysis were identified by their staining reactions, mobility on paper and ion-exchange column chromatography, and by the molar glycerol to phosphate ratios. Eleven diacyl phospholipids can be separated by two-dimensional thin-layer chromatography. Each lipid served as a substrate for phospholipase D, and had a fatty acid to phosphate ratio of 2:1. Each separated diacyl phospholipid was deacylated and the glycerol phosphate ester was identified by paper chromatography in four solvent systems. Of the 11 separated phospholipids, 3 were phosphatidylethanolamines, 2 were phosphatidylserines, and 2 were phosphatidylglycerols. Phosphatidylcholine, cardiolipin, and phosphatidic acid were found at a single location. Phosphatidylmonomethylethanolamine was found with the major phosphatidylethanolamine. Three distinct classes of phospholipids are separable according to their relative fatty acid compositions. (i) The trace lipids consist of two phosphatidylethanolamines, two phosphatidylserines, phosphatidylcholine, phosphatidic acid, and a phosphatidylglycerol. Each lipid represents less than 0.3% of the total lipid phosphate. These lipids are characterized by high proportions of the short (C10 to C14) and long (C19 to C22) fatty acids with practically no palmitoleic acid. (ii) The major phospholipids (93% of the lipid phosphate) are phosphatidylethanolamine, phosphatidylmonomethylethanolamine, and phosphatidylglycerol. These lipids contain a low proportion of the short ( C19) fatty acids. Palmitic and palmitoleic acids represent over 80% of the total fatty acids. (iii) The fatty acid composition of the cardiolipin is intermediate between the other two classes. Both palmitoleic and the longer fatty acids represent a significant proportion of the total fatty acid.

The ultrastructure of the enamel organ related to enamel formation.

Abstract: The ultrastructure of the cells of the enamel organ related to enamel formation was studied using the lower incisors of adult male rats In the region of enamel deposition, stratum intermedium cells are stabilized by a system of intercellular bridges and intracellular fibrils The mitochondria in these cells are positioned toward the extracellular channels through which any direct intercellular exchange between the capillaries and ameloblasts must occur Tentatively, the mitochondrial arrangement is considered to be related to the movements of electrolytes and water across the capillary-ameloblast interval In the region of transition, enamel deposition ceases and the ergastoplasm of the ameloblasts is removed, apparently by cytosegresomes, with an accompanying reduction in the height of the ameloblasts Here, vesicles containing stippled material are infrequent compared to their occurrence in ameloblasts concerned with enamel deposition Other vesicles, characteristically found in ameloblasts related to maturing enamel, first appear in the transition region and seem to originate from the cell membrane abutting on the enamel In the region of maturation, cytosomes are common in the Golgi region whereas vesicles and mitochondria predominate in the distal ends of the ameloblasts The papillary cells contain an unusually large number of mitochondria, elaborate microvilli and vesicles, which suggests that these cells are extremely active, presumably in the movement of materials related to enamel maturation The changes in structure of the papillary cells, which occur concomitantly with those of the ameloblasts during enamel formation, are indicative of interrelated functional changes and strongly support the concept of ameloblasts and papillary cells acting together as a functional unit

One approach to highway automation

Abstract: Considerable improvements in highway capacity and highway safety can be achieved by vehicle automation. Many approaches to automation are possible, with any given approach depending on one's premises concerning the future state of the transportation system. Described here is the approach taken at the Communication and Control Systems Laboratory of The Ohio State University, which is based on the following: 1) the individual transportation unit should be retained; 2) an automatic system should be gradually introdnced and be compatible with existing traffic at all stages; and 3) only limited-access highways will be automated. The resulting design is divided into three parts-longitudinal control, lateral control, and intersection and lane-changing control. Two aspects of the longitudinal control problem--automatic system control and driver control--are discussed in detail Typical road-test data from both an automatic longitudinal control system and a driver-aided system are presented. In addition, an automatic steering system is discussed together with typical experimental results.

Colonial Behavior of Eptesicus fuscus

Abstract: Big brown bats, Eptesicus fuscus , were studied at maternity colonies in buildings in Kentucky Bats arrived at the colonies in May, and colonies contained few adult males before the young were weaned Young were born in early June Mothers left even the youngest babies behind during feeding flights, and mothers retrieved their fallen babies from the floor and recognized their own Young bats grew rapidly; growth curves are presented After parturition mother bats fed close by and returned soon to their babies; as the young matured the mothers stayed away longer When 3 weeks old the young could fly, and by mid-June mothers and young were using a night roost Adults filled their stomachs in about an hour of feeding Big brown bats were not tolerant of heat, and left a roosting spot at temperatures above 92°–95°F This is a rather sedentary species; most movements recorded were of a few miles or less

A methanol poisoning outbreak in Kentucky. A clinical epidemiologic study.

Abstract: A change in the brand of shellac thinner used to make an alcoholic beverage resulted in six deaths from methanol poisoning. In screening all potentially poisoned persons available with serum methanol, ethanol, pH, and electrolyte determinations, many asymptomatic methanol poisonings were discovered. A correlation was established between severity of illness and level of ethanol, further suggesting a protective effect. Among different types of treatment used with the 12 hospitalized cases peritoneal dialysis was shown to be effective, with a clearance rate five to ten times that obtained with forced fluid diuresis.

Electron Transport System of the Protoheme-requiring Anaerobe Bacteroides melaninogenicus

Abstract: Protoheme is essential for the growth of some strains of Bacteroides melaninogenicus. At low concentrations in the growth medium, protoheme determines the doubling time, total cell yield, and amount of cytochrome per bacterium. At high protoheme concentrations, the doubling time, total cell yield, and amount of enzymatically reducible cytochrome appear to remain nearly constant, and protoheme is accumulated by the cell. The accumulated protoheme can support the growth of the bacterium for at least eight generations in a protoheme-free medium. When growth and cytochrome content are proportional during growth at low protoheme concentrations, the bacteria incorporate 10 to 20% of the total available protoheme into a membrane-bound respiratory system. This respiratory system includes cytochrome c, a carbon monoxide-binding pigment, and possibly flavoproteins. The pigments can be reversibly reduced by reduced nicotinamide adenine dinucleotide or endogenous metabolism and can be oxidized anaerobically by fumarate or by shaking in air. Electron transport is inhibited by 2-n-nonyl-4-hydroxy-quinoline-N-oxide.

The Elastic Constants of Crystalline Native Cellulose

Abstract: A new theoretical analysis is made of the elastic constants of crystalline native cellulose. Primary interatomic forces are considered in the calculation of the Young modulus in the chain direction, where we retrieve a result identical to that of Treloar. Hydrogen bonds provide the main mechanism for determining all the other elastic constants, most of which are here calculated for the first time. The lateral Young moduli are found to be surprisingly high. Van der Waals interactions are assumed to play a subsidiary role to that of hydrogen bonds, but this factor remains to be quantitatively assessed. The relation of theory to experiment is critically examined.