Showing papers by "University of California, Davis published in 1978"
TL;DR: In this article, a review of the algebras related to Kronecker products is presented, which have several applications in system theory including the analysis of stochastic steady state.
Abstract: The paper begins with a review of the algebras related to Kronecker products. These algebras have several applications in system theory including the analysis of stochastic steady state. The calculus of matrix valued functions of matrices is reviewed in the second part of the paper. This calculus is then used to develop an interesting new method for the identifiication of parameters of lnear time-invariant system models.
1,944 citations
TL;DR: In this article, a simple way to model the pressure-containing correlations which appear in the transport equations for Reynolds stress and heat flux was proposed, which accounts for gravitational effects and the modification of the fluctuating pressure field by the presence of a wall.
Abstract: Proposals are made for modelling the pressure-containing correlations which appear in the transport equations for Reynolds stress and heat flux in a simple way which accounts for gravitational effects and the modification of the fluctuating pressure field by the presence of a wall. The predicted changes in structure are shown to agree with Young's (1975) measurements in a free stratified shear flow and with the Kansas data on the atmospheric surface layer.
1,482 citations
TL;DR: In this article, a colorimetric assay utilizing m-hydroxydiphenyl is recommended because of its low background readings in the presence of large quantities of neutral sugars.
Abstract: Reproducible determinations of cell wall uronic acid content are obtained by first dissolving wall samples in sulfuric acid and then performing assays on aliquots of the cell wall solution The colorimetric assay utilizing m-hydroxydiphenyl is recommended because of its low background readings in the presence of large quantities of neutral sugars
658 citations
TL;DR: In this paper, two sets of expanded tables have been compiled for use in determining significance in paireddifference and triangle tests (one-tailed) and in paired preference tests (two-tailed).
Abstract: Two sets of expanded tables have been compiled for use in determining significance in paired-difference and triangle tests (one-tailed) and in paired-preference tests (two-tailed). One set of tables lists the number of correct responses (or agreeing judgments) for trials ranging from 7–100, at p < 0.05, 0.04, 0.03, 0.02, 0.01, 0.005 and 0.001. These tables are convenient for a quick estimate of significance of laboratory sensory data as well as consumer responses. The second set of tables gives the probabilities of obtaining a given number of correct (or agreeing) judgments in trials ranging from 5–50. These probability tables provide a more precise estimate of significance, which may be needed in more critical research or in making decisions of considerable importance. Some examples are given, with guidelines for the proper use of these tables and the interpretation of significance based upon them.
424 citations
TL;DR: A variety of peptide and protein substrates are shown to bind to the ion exchange papers under conditions in which contaminating [γ- 32 P]ATP is removed by washing in acetic acid.
336 citations
TL;DR: In this article, the effects of the principal physical and chemical factors on the rate of erosion of saturated cohesive soils are described and analyzed. But the authors do not describe the relationship between these factors and the erodibility of the soil.
Abstract: The objective of this paper is to describe the effects of the principal physical and chemical factors on the rate of erosion of saturated cohesive soils. It is hoped that this work stimulates more comprehensive laboratory and field measurements of the erosion of cohesive soils with a view of obtaining relationships for the erodibility in terms of easily measured physical and chemical properties of the soil.
279 citations
TL;DR: This chapter discusses about histamine toxicity from fish products, generally involves the ingestion of scombroid fish from the families Scomberesocidae and Scombridae, and the use of ammonia levels as a freshness indicator becomes unreliable when fish are kept at a room temperatures of 20°C.
Abstract: Publisher Summary This chapter discusses about histamine toxicity from fish products, often called scombroid poisoning, generally involves the ingestion of scombroid fish from the families Scomberesocidae and Scombridae. Scombroid fish include saury, tuna, bonito, seerfish, butterfly kingfish, and mackerel. The free histidine can, under certain conditions, be decarboxylated by some bacteria to produce high levels of histamine. Scombroid fish poisoning clinically resembles that of histamine poisoning intoxication, although controversy still exists as to whether histamine ingested orally is actually toxic, whether histamine is the sole toxic factor or not. It is generally found at high concentrations in foods causing scombroid poisoning. “Samma sakuraboshi” was incriminated in many of the Japanese histamine and histamine–like fish poisonings. The incriminated fish generally contains histamine levels in excess of 100 mg%. No fish could be obtained for chemical analysis, but the outbreak was presumed to be caused by bacterial degradation of histidine to histamine. It is most likely that the histamine produced by autolysis was because of previous bacterial contamination or unsterile conditions during experimentation, thus enabling histamine production by the contaminating microorganisms. However, the use of ammonia levels as a freshness indicator becomes unreliable when fish are kept at a room temperatures of 20°C. Several studies of bacterial histidine decarboxylase have indicated that the addition of vitamins and coenzymes did not enhance histamine formation. Histamine formation in aerated cultures, achieved by the addition of bubbled gas, was much less than that from anaerobic and aerobic cultures.
268 citations
TL;DR: Five species of rumen bacteria with overlapping substrate fermentative capabilities were tested for substrate preferences and evidence of catabolite regulatory mechanisms, suggesting that the five bacteria have different strategies of substrate utilization and thus occupy separate niches in the rumen.
Abstract: Five species of rumen bacteria with overlapping substrate fermentative capabilities were tested for substrate preferences and evidence of catabolite regulatory mechanisms. All five bacteria showed evidence of some type of catabolite regulatory mechanism. In the six-substrate test system that was used, utilization of every substrate was inhibited by another substrate in at least one of the bacteria. Inhibited versus noninhibited substrate data suggest that the five bacteria have different strategies of substrate utilization and thus occupy separate niches in the rumen. The significance of these observations to understanding the rumen ecosystem is discussed.
267 citations
TL;DR: In this paper, the procedure for calculating the position of the sun by computer is discussed, and the equations used to generate the values in The American Ephemeris and Nautical Almanac are presented in a simplified form that allows the sun to be calculated rapidly to an accuracy of 0.01°.
258 citations
TL;DR: In this article, the authors present evidence bearing on the geographic hypothesis advanced eight years ago to explain the striking ethnic or racial differences in prevalence of primary adult lactose malabsorption that are found around the world.
Abstract: Reviewed in this article is evidence bearing on the geographic hypothesis advanced eight years ago to explain the striking ethnic or racial differences in prevalence of primary adult lactose malabsorption that are found around the world. Most evidence is found to support the hypothesis and the likelihood that some human groups came to have low prevalences of such lactose malabsorption because of selective pressures over a long historical period that favored the adult lactose absorber under particular ecological conditions.
247 citations
TL;DR: The results of the labeling experiments showed that propionate is formed from succinate via succinyl-, methylmalonyl-, and propionyl-coenzyme A, and it also is clear that CO(2) is necessary for growth because it is needed for the formation of C4 acids.
Abstract: Cell suspensions of Bacteroides fragilis were allowed to ferment glucose and lactate labeled with 14C in different positions. The fermentation products, propionate and acetate, were isolated, and the distribution of radioactivity was determined. An analysis of key enzymes of possible pathways was also made. The results of the labeling experiments showed that: (i) B. fragilis ferments glucose via the Embden-Meyerhof pathway; and (ii) there was a randomization of carbons 1, 2, and 6 of glucose during conversion to propionate, which is in accordance with propionate formation via fumarate and succinate. The enzymes 6-phosphofrucktokinase (pyrophosphate-dependent), fructose-1,6-diphosphate aldolase, phosphoenolpyruvate carboxykinase, malate dehydrogenase, fumarate reductase, and methylmalonyl-coenzyme A mutase could be demonstrated in cell extracts. Their presence supported the labeling results and suggested that propionate is formed from succinate via succinyl-, methylmalonyl-, and propionyl-coenzyme A. From the results it also is clear that CO2 is necessary for growth because it is needed for the formation of C4 acids. There was also a randomization of carbons 1, 2, and 6 of glucose during conversion to acetate, which indicated that pyruvate kinase played a minor role in pyruvate formation from phosphoenolpyruvate. Phosphoenolpyruvate carboxykinase, oxaloacetate decarboxylase, and malic enzyme (nicotinamide adenine dinucleotide phosphate-dependent) were present in cell extracts of B. fragilis, and the results of the labeling experiments agreed with pyruvate synthesis via oxaloacetate and malate if these acids are in equilibrium with fumarate. The conversion of [2-14C]- and [3-14C]lactate to acetate was not associated with a randomization of radioactivity.
TL;DR: A way of generating restriction endonuclease cleavage sites by single base changes derived after in vitro methylation of single-stranded DNA is described.
Abstract: RESTRICTION endonucleases recognise specific sequences in DNA, and these endonucleases, especially those which generate cohesive ends, have been widely used to clone DNA1. However, many DNAs lack sequences which are recognised by endonucleases such as EcoRI, HindIII or BamHI. A general method of overcoming this problem has been described recently2. This approach involves the synthesis of oligonucleotides sensitive to a specific endonuclease and the blunt end ligation of these molecules to the DNA to be cloned. In contrast, we sought a method which avoids the insertion of additional nucleotides into a DNA sequence, but depends on direct modification of DNA. If a DNA sequence differs in only one base pair from the recognition sequence of a restriction endonuclease, a particular change of this base pair will generate the proper sequence. Here we describe a way of generating restriction endonuclease cleavage sites by single base changes derived after in vitro methylation of single-stranded DNA.
TL;DR: It is suggested that loss of taste and smell as a result of deficiency may account for refusal of experimental animals to eat and drink enough to prevent inanitation and dehydration and may mask the true hematological picture, which is one of anemia.
TL;DR: An elementary theory to explain how cultural inheritance affects the evolutionary process is developed, formally a two- person variable sum game in which genes and culture compete to control phenotype, although the conservatively Neo-Darwinian capacity-for-culture assumption ensures that culture will benefit genotype.
Abstract: Human evolution presents special problems for Neo-Darwinian theory because a second system of inheritance, culture, is an important determinant of phenotype in our species. An elementary theory to explain how cultural inheritance affects the evolutionary process is developed from three basic postulates: (1) both genes and culture evolve by natural selection; (2) the reproductive fitness optimum as a function of phenotype is different for genes and culture because the rules of inheritance of the two systems are different; and (3) a genetic capacity for culture is assumed to be optimized by selection with respect to genetic fitness. The theory is formally a two-person variable sum game in which genes and culture compete to control phenotype, although the conservatively Neo-Darwinian capacity-for-culture assumption ensures that culture will benefit genotype. Simple mathematical models are used to deduce the general properties of equilibrium phenotypes. Results include the possibility that under some circumstances phenotype may be at the cultural rather than the genetic fitness optimum. Particularly if it is assumed that the capacity for culture is a general trait permitting many specific cultural ones, the culture capacity will be like a pleiotropic gene and many cultural traits are likely to be at the cultural optimum. The fact that in a majority of human societies, people bias their kinship behavior in ways unexpected from degree of genetic relatedness may be an example of the effect of selection on culture.
TL;DR: While the distinctive clinical appearance of most corneal dystrophies allows accurate diagnosis, the integration of slitlamp findings with histopathologic and biochemical findings aids in the understanding of the clinical observations and provides a more rational basis for therapy.
TL;DR: It is concluded that strong selection operates at all life cycle stages in CCV, although often in differing directions.
Abstract: Viability and fertility components of selection associated with linkage blocks marked by four electrophoretically detectable loci were estimated in an experimental population of barley [Composite Cross V (CCV)]. The intensity of selection affecting the distribution of pollen types in the outcross pool was also estimated and comparisons were made between the selective values of genes in the pools of uniting ovules and pollen. The estimates show that selection was intense at various stages of the life cycle and that viability and fertility components often opposed one another. Estimates of viability and fertility components of selection were also extended to the three-locus level. The multilocus estimates reveal large differences in viability and fertility among homozygous genotypes. It is concluded that strong selection operates at all life cycle stages in CCV, although often in differing directions.
TL;DR: In this article, nonpatient responses to five major adjustment scales were examined at three time-points, two weeks apart, and no evidence for a systematic increase in adjustment scores due to completing the instruments.
Abstract: Nonpatient responses to five major adjustment scales were examined at three time-points, two weeks apart. There was no evidence for a systematic increase in adjustment scores due to completing the instruments. Internal consistency coefficients and test-retest stability coefficients for the five adjustment scales show them to have utility for assessing patient groups. Only the SCL-90 showed promise for allowing reliable assessment of individual change over time. All five scales significantly discriminate patient groups from groups of nonpatients. Further research is needed to clarify present results, to determine the clinical significance of various magnitude changes on the scales, and to develop more specific measures of adjustment and symptomatology.
TL;DR: In this paper, a chart recorder was used to monitor time, time-intensity (T-I) measurements of the intensity and the duration of sweetness, bitterness, sourness and flavor in distilled water, and the same characteristics, plus flavor in three flavored drinks, and two flavored gelatins, sweetened with sucrose, cyclamate, or saccharin.
Abstract: By paired comparison methods, concentrations of 0.75% and 0.86% calcium cyclamate and of 0.17% and 0.19% aspartame were equivalent in sweetness to 10% sucrose in distilled water at 3° and 22°C, respectively. Inherent bitterness of the compounds prevented precise assessment of relative sweetness for sodium saccharin in distilled water, and for the saccharin and cyclamate in flavored drinks. By application of linear regression to the paired comparison data, 0.07% aspartame was calculated as equal in sweetness to 10% sucrose in lemon, strawberry and orange drinks. Because the underlying bitterness of saccharin interfered with assessment of its sweetness, a time-intensity technique was applied. Using a chart recorder to monitor time, time-intensity (T-I) measurements were made of the intensity and the duration of sweetness, bitterness, sourness and flavor in distilled water, and the same characteristics, plus flavor in three flavored drinks, and two flavored gelatins, sweetened with sucrose, cyclamate, or saccharin. T-I curves for the sensory properties of aspartame closely resembled those for sucrose in all media. Cyclamate and saccharin imparted a marked, persistent bitterness to all carriers. In gelatin, samples containing 18% sucrose were firmer initially and took longer to manipulate to a liquid in the mouth than did gelatins containing 0.105% aspartame, 0.55% cyclamate, or 0.05% saccharin.
TL;DR: A biophysical model for the pollen/locule wall interactions resulting in pollen expulsion upon bee or artificial vibration is developed and is generally applicable to any apically dehiscent flower which is vibrated by bees to release pollen.
TL;DR: Observations indicate a close interrelationship between the induction of PAL activity and the development of RS in response to ethylene, and suggest a causal relationship between the two events.
Abstract: Russet spotting (RS), consisting of numerous small brown spots on the midrib of head lettuce (Lactuca sativa), is a physiological disorder induced by exposure to ethylene. In leaves suffering RS, the increase in spotting was accompanied by a parallel increase in the amount of phenolic compounds. Of these, chlorogenic acid and isochlorogenic acid were identified. Ethylene induced high phenylalanine ammonia-lyase (PAL) activity and RS formation in the susceptible cultivar Salinas, but not in the resistant cultivar Calmar. In the absence of ethylene neither significant PAL induction nor RS occurred. No correlation was found between the increase in polyphenol oxidase or peroxidase and the development of RS. The increase in PAL activity, however, was closely correlated with the development of RS. The increase in PAL activity preceded the development of RS, and the extent of RS was directly related to the level of PAL. Three temperatures (0.5, 5.5, and 12.5 C) were compared on the basis of their influence on both RS and PAL induction. At the lowest temperature (0.5 C) neither PAL induction nor RS occurred to a significant extent. At the highest temperature (12.5 C) an initial rapid increase in PAL activity and an earlier development of spotting were observed, but subsequently there was a decrease in both PAL activity and the rate of development of RS. At the medium temperature (5.5 C) both PAL activity and RS increased progresively with time. The decline of PAL activity at a higher temperature might be attributed to inactivation of the enzyme. Thus, a temperature favorable for induction of PAL activity by ethylene was also favorable for RS. These observations indicate a close interrelationship between the induction of PAL activity and the development of RS in response to ethylene, and suggest a causal relationship between the two events. PAL serves as a useful biochemical marker for the RS reaction.
TL;DR: The ABTS method was found to be three times as sensitive as the older o -dianisidine method and correlated highly with those obtained by acid hydrolysis for rabbit liver glycogen.
TL;DR: Morphometric data describing the variation of structure with depth in the tracheobronchial airways are presented in the form of graphical representations of anatomical measurements on replica casts of the human, dog, rat and hamster airways.
Abstract: Application of an Idealized Model to Morphometry of the Mammalian Tracheobronchial Tree R. F. PHALEN,' H. C. YEH,3 G. M. SCHUM AND 0. G. RAABE 'Department of Community and Environmental Medicine, College of Medicine, Uniuersity of California, Iruine. California 9271 7; Inhalation Toxicology Research Institute, P. 0. Box 5890, Albuquerque, New Mexico 871 15and Radiobiology Laboratory and Department of Radiological Sciences, School of Veterinary Medicine, University of California, Davis, California 9561 6 ABSTRACT Quantitative anatomical descriptions (morphometry) of the tracheobronchial airways are of importance in many applications including the preparation of successful mathematical models describing airflow patterns and deposition patterns of airborne particles in the lung. Morphometric data are also useful in studies of comparative anatomy and in describing normal and diseased states of a n organ. The collection of such data is aided by the use of idealized models of airway branches of the tracheobronchial airways. Morphometric mea- surements from the lungs of several mammalian species are presented using a model t h a t consists of three connected tubular segments. The morphometric model uniquely defines an identification number for each branch segment, a branching angle, an airway segment length and diameter, an inclination of a seg- ment to gravity and the degree of alveolarization of each segment. Designed to be compatible with computerized data handling, the model is unambiguous and realistic, but flexible so that anomalous anatomical structures can be classified and noted. Morphometric data describing the variation of structure with depth in the tracheobronchial airways are presented in the form of graphical representa- tions of anatomical measurements on replica casts of the human, dog, rat and hamster airways. These distributions describe the anatomical character of the tracheobronchial airways concisely, quantitatively, and characteristically for each species. Interest in the mammalian respiratory tract as both a portal for entry of inhaled ma- terials and as a primary target for several environmentally-related disease processes has provided recent impetus for improved infor- mation on the anatomy of the airways (Hanna e t al., '70; International Commission on Ra- diological Protection, Task Group on Lung Dynamics, '66; Thurlbeck, '73). For example, development of mathematical models for pre- dicting what fraction of and where inhaled particles will deposit require input informa- tion in three categories: aerosol physics, fluid dynamics and anatomy. The physical forces acting on airborne particles to influence their deposition must be known. The basic influ- ences due to gravity, impaction and diffusion are relatively well understood for particle sizes most frequently seen in the industrial and urban environments. The nature of air- ANAT. REC. flow within the respiratory tract must be known, including Reynolds' numbers and pri- mary and secondary flow patterns (Schroter et al., '69). Unfortunately, many uncertainties still exist in this area. The detailed geometry of the respiratory tract airspace, and its dynamics, must also be specified. One should know the lengths, diameters, (assuming a right circular cylindrical shape), inclinations to gravity and branch angles for all respirato- ry tubes. This work concentrates on the last category, the normal anatomy of the tracheobronchial airways. The method used for quantitating airway anatomy involved making measure- ments on silicone rubber replica casts of mam- Received July 29, '76. Accepted Aug. 5, '77. ' Research supported by the National Institute of Environmental with Health Sciences (NIEHS) via AEC Contract AT (29-2)-1013 Lovelace Foundation, and in part by California Air Reeources Board Contract Number ARB 5-725.
TL;DR: In this review, the authors discuss three endothelial dystrophies -- Fuchs', posterior polymorphous and congenital hereditary and describe the clinical, histopathologic and biochemical features, and illustrate each dystrophy with a composite drawing.
Journal Article•
TL;DR: Heart rate, total peripheral resistance, pulmonary artery pressure, hematocrit, plasma protein concentration, arterial oxygen tension, and arterial pH remained constant over the same range of anesthetic dosages.
Abstract: Cardiovascular effects of venous alveolar concentrations of halothane in oxygen were studied in 8 young, healthy horses under conditions of constant arterial carbon dioxide tension. The alveolar concentration of halothane was expressed as a multiple of the minimal alveolar concentration (MAC) which was known for each animal. Increasing alveolar halothane concentrations to MAC 2.0 resulted in a progressive and significant (P less than 0.05) decline in systemic arterial pressure and left ventricular work. Cardiac output decreased between MAC 1.0 and MAC 2.0 as a result of a significant (P less than 0.05) decrease in stroke volume. Heart rate, total peripheral resistance, pulmonary artery pressure, hematocrit, plasma protein concentration, arterial oxygen tension, and arterial pH remained constant over the same range of anesthetic dosages. Continuation of anesthesia, spontaneous ventilation, and the accompanying rise in arterial carbon dioxide tension and electrical stimulation of the horse's oral mucous membranes produced varying degrees of stimulation of cardiovascular function at MAC 1.5.
TL;DR: In this article, high sensitivity experiments with particles that are strongly enriched in alpha-emitting nuclei show that damaged regions are produced that can be eroded by subsequent exposure to water.
TL;DR: In rhesus monkeys it appears as though the MP-AH region is specifically involved in the mediation of heterosexual copulation and is not vital to the performance of other forms of male sexual activity such as masturbation.
TL;DR: Purification of starch branching enzymes from kernels of two nonlinked mutants of maize, sugary and amylose-extender, showed the basis of the two mutations to be associated with branching enzymes I and IIb, respectively.
TL;DR: The antigenic relationship of the feline infectious peritonitis virus (FIPV) to 7 other human and animal coronaviruses was studied and FIPV was found to be closely related to transmissible gastroenteritis virus of swine.
Abstract: Utilizing the direct and indirect fluorescent antibody procedure, the antigenic relationship of the feline infectious peritonitis virus (FIPV) to 7 other human and animal coronaviruses was studied. FIPV was found to be closely related to transmissible gastroenteritis virus (TGEV) of swine. Transmissible gastroenteritis virus and FIPV were in turn antigenically related to human coronavirus 229E (HCV-229E) and canine coronavirus (CCV). An interesting finding in the study was that the 8 coronaviruses selected for this study fell into one of two antigenically distinct groups. Viruses in each group were antigenically related to each other to varying degrees, but were antigenically unrelated to coronaviruses of the second group. The first antigenically related group was comprised of mouse hepatitis virus, type 3 (MHV-3), hemeagglutinating encephalomyelitis virus 67N (HEV-67N) of swine, calf diarrhea coronavirus (CDCV), and human coronavirus OC43 (HCV-OC43). The second antigenically related group was comprised of FIPV, TGEV, HCV-229E and CCV.
TL;DR: In this article, the effects of low concentrations of five selected hydrocolloids (xanthan, hydroxypropylcellulose, sodium alginate, and carboxymethylcelluloses of low and medium viscosity types) on viscosities and sensory properties of 3 commercial beverages: tomato juice, orange drink and soluble coffee.
Abstract: The effects were studied of low concentrations of 5 selected hydrocolloids (xanthan, hydroxypropylcellulose, sodium alginate, and carboxymethylcellulose of low and medium viscosity types) on viscosity and sensory properties of 3 commercial beverages: tomato juice, orange drink and soluble coffee. Tomato juice and orange drink were tested at 0° and 22°C, while coffee was tested at 22° and 60°C by 11-14 highly trained judges. Apparent physical viscosity was determined with a Brookfield uiscometer. Due to precipitate formation, it was not possible to test sodium alginate in orange drink nor hydroxypropylcellulose in coffee at 60°C.
Without exception, increasing the hydrocolloid concentration significantly depressed (P < 0.001) the flavor and aroma intensities of all beverages a t both test temperatures. Taste effects were specific for the gumlbeverage combinations. In general, gums depressed the sourness and saltiness of tomato juice, the sourness of orange drink and the bitterness of coffee.
Both physical and oral viscosities increased with gum concentration and decreased with temperature. Positive synergism was displayed by gums in tomato juice and orange drink. Excellent correlations (r > 0.9) were obtained between sensory and physical viscosities.