Showing papers by "University of California, Santa Cruz published in 1973"

Endoplasmic reticulum as the site of lecithin formation in castor bean endosperm

Abstract: The properties of a discrete membranous fraction isolated on sucrose gradients from castor bean endosperm have been examined. This fraction was previously shown to be the exclusive site of phosphorylcholine-glyceride transferase. The distribution of NADPH-cytochrome c reductase and antimycin insensitive NADH-cytochrome c reductase across the gradient followed closely that of the phosphorylcholine-glyceride transferase. This fraction also had NADH diaphorase activity and contained cytochromes b5 and P 450. On sucrose gradients containing 1 mM EDTA this fraction had a mean isopycnic density of 1.12 g/cm3 and sedimented separately from the ribosomes; electron micrographs showed that it was comprised of smooth membranes. When magnesium was included in the gradients to prevent the dissociation of membrane-bound ribosomes, the isopycnic density of the membrane fraction with its associated enzymes was increased to 1.16 g/cm3 and under these conditions the electron micrographs showed that the membranes had the typical appearance of rough endoplasmic reticulum. Together these data show that the endoplasmic reticulum is the exclusive site of lecithin formation in the castor bean endosperm and establish a central role for this cytoplasmic component in the biogenesis of cell membranes.

Parties as Utility Maximizers

Abstract: The article introduces two models of political party decision making. Both models assume that the parties are solely interested in policy and that winning the election is just a means to that end. In one, the parties are competitive, while in the other the parties collude. The main result, in either case, is that the parties tend to be unresponsive to the interests of the voters.The models are analyzed in an intransitive case (an election concerned only with income distribution) and a transitive one (an election where all political attitudes can be put on a left-right continuum), and under the assumptions of perfect and imperfect information.With perfect information the intransitive case results in the parties ending up with all the income; while in the single peaked case neither party will have a position to the left (right) of the left (right) party's most preferred position whatever the attitudes of the voters.Finally it is shown that it is rational for the parties to collude and present similar platforms.

Perinatal behavior of northern elephant seal females and their young.

Abstract: Northern elephant seal females and pups were observed during four breeding seasons at Ano Nuevo Tstand, California. Six to seven days after a female arrived on the rookery she gave birth to a single pup which she nursed for four weeks. Estrus began 24 days after parturition and lasted an average of four days. Females spent a total of 34 days on the rookery before returning to sea. The only other time females came ashore was to moult, a period which lasted a few weeks. Most births occurred in the harem at night during the last two weeks of January. Cephalic presentations were more frequent than caudals (62% vs. 38%) and both were equally rapid. The placenta was delivered immediately after the pup or within an hour after birth. Stillbirths were infrequent and premature pups were never observed. The sex ratio was 49.4 males to 50.5 females. Eight females gave birth for the first time during their third year but most females are believed to give birth later. Three females gave birth on a different rookery than their own birthplace. The time of parturition from year to year was very consistent in individual females. Newborn pups weighed 65 lbs at birth and were 60 inches long. They are precocial and suckled for about four weeks before being weaned. Weaners moulted their natal pelage at four to six weeks of age, a time when they began entering the water. Most weaners left the rookery headed north during the month of April. Females accepted a pup by allowing it to nurse and rejected alien pups by biting them. Females emitted two vocalizations : a pup attraction call and a threat vocalization. Pups emitted a single vocalization which functioned in several situations. Scventy-two percent of the females observed nursed their own pups to weaning and rejected most of the suckling attempts of alien pups. A few females nursed an alien pup in addition to their own. Twenty-six percent of the females became separated from their pups or their pups died. One third of these females adopted an alien pup. Females that gave birth, but did not nurse for several days, did not copulate. The frequency and duration of suckling increased as pups developed. Pups attempted to suckle any available female but were rejected by most alien females. Sixty percent of marked pups suckled their mothers. The remaining forty percent were separated from their mothers and most of them died. Those that survived were adopted by an alien female or were suckled by several different females each day. Pup mortality at Ano Nuevo Island was very consistent over the four year period, ranging from 13.0% to 14.5%. Most mortalities were socially induced; pups separated from their mothers starved or were injured by adult males and females. The probability of separation was increased by high numbers of females and disturbances created by intrusions of breeding hulls into the harem.

The avoidance of (relative) catastrophe, heuristic competence, genuine dynamic weighting and computational issues in heuristic problem solving

Abstract: To solve difficult problems heuristically, requires detailed attention to computational efficiency This paper describes how a heuristic problem solving system, HPA, attempts to find a near optimal solution to the traveling salesman problem A critical innovation over previous search algorithms is an explicit dynamic weighting of the heuristic information The heuristic information is weighted inversely proportional to its depth in the search tree -- in consequence it produces a narrower depth first search than traditional weightings At the same time, dynamic weighting retains the catastrophe protection of ordinary branch and bound algorithms

Abalones and Sea Urchins in an Area Inhabited by Sea Otters

Abstract: Abalones (Haliotis spp.) and sea urchins (Strongylocentrotus spp.) are part of the subtidal fauna in the kelp bed off Hopkins Marine Station, Pacific Grove, California, USA, a protected marine reserve. Although these animals have been preyed upon by sea otters for over 10 years, their densities are gubstantial (Haliotis spp.: 0.21/m2; Strongylocentrotus spp.: 0.22/m2), and two species, H. rufescens (Swainson) and S. purpuratus (Stimpson), have wide size distributions indicating broad age ranges. Most of the adult abalones and sea urchins occur clustered deep in crevices, either as a direct result of sea-otter predation or because ample drift of algal food reduces foraging activities. Abalones tend to occur in larger crevices than sea urchins, and competition for suitable crevice space may exist among these large, invertebrate, algal-drift feeders.

Performance and mood following variations in the length and timing of sleep.

Abstract: The relative effects of extended sleep, sleep deprivation, and shifts of accustomed sleep time on subsequent performance and mood were studied. Ten regular 2400–0800 sleepers worked on E-paced addition and vigilance tasks, and completed an adjective check list to rate their mood following 2100-0800 extended, 2100-0500 advanced-shift, 2400-0800 habitual, 0300-0800 deprivation, and 0300-1100 delayed-shift conditions of sleep. Accuracy and speed of response on the vigilance task were significantly poorer, and negative affect was significantly greater after the conditions of shifted sleep and altered sleep duration than after the habitual sleep condition. Changes in the mood and performance measures were unrelated to prior sleep length or any specific alterations in the electrophysiological patterns of sleep.

Enzymes of phospholipid metabolism in the endoplasmic reticulum of castor bean endosperm.

Abstract: The intracellular location of several enzymes concerned with phospholipid metabolism was investigated by examining their distribution in organelles separated on sucrose gradients from total homogenates of castor bean (Ricinus communis var Hale) endosperm The enzymes phosphatidic acid phosphatase, CDP-diglyceride-inositol transferase, and phosphatidyletha-nolamine-l-serine phosphatidyl transferase were all primarily or exclusively confined to membranes of the endoplasmic reticulum These results and those reported previously on lecithin synthesis establish a major role of the endoplasmic reticulum in phospholipid and membrane synthesis in plant tissues

Localization of enzymes within microbodies.

Abstract: Microbodies from rat liver and a variety of plant tissues were osmotically shocked and subsequently centrifuged at 40,000 g for 30 min to yield supernatant and pellet fractions. From rat liver microbodies, all of the uricase activity but little glycolate oxidase or catalase activity were recovered in the pellet, which probably contained the crystalline cores as many other reports had shown. All the measured enzymes in spinach leaf microbodies were solubilized. With microbodies from potato tuber, further sucrose gradient centrifugation of the pellet yielded a fraction at density 1.28 g/cm3 which, presumably representing the crystalline cores, contained 7% of the total catalase activity but no uricase or glycolate oxidase activity. Using microbodies from castor bean endosperm (glyoxysomes), 50–60% of the malate dehydrogenase, fatty acyl CoA dehydrogenase, and crotonase and 90% of the malate synthetase and citrate synthetase were recovered in the pellet, which also contained 96% of the radioactivity when lecithin in the glyoxysomal membrane had been labeled by previous treatment of the tissue with [14C]choline. When the labeled pellet was centrifuged to equilibrium on a sucrose gradient, all the radioactivity, protein, and enzyme activities were recovered together at peak density 1.21–1.22 g/cm3, whereas the original glyoxysomes appeared at density 1.24 g/cm3. Electron microscopy showed that the fraction at 1.21–1.22 g/cm3 was comprised of intact glyoxysomal membranes. All of the membrane-bound enzymes were stripped off with 0.15 M KCl, leaving the "ghosts" still intact as revealed by electron microscopy and sucrose gradient centrifugation. It is concluded that the crystalline cores of plant microbodies contain no uricase and are not particularly enriched with catalase. Some of the enzymes in glyoxysomes are associated with the membranes and this probably has functional significance.

Learning: Classical and Avoidance Conditioning in the Mollusk Pleurobranchaea

Abstract: Naive specimens of the marine gastropod Pleurobranchaea withdraw from tactile stimulation of the oral veil and show feeding responses to food chemicals. Experimental subjects, trained by pairing touch (conditioned stimullus) with food chemicals (unconditioned stimulus), soon acquired a classically conditioned feeding response to touch alone. Control subjects that received touch alone or unpaired touch and food chemicals showed significantly fewer feeding responses to touch than did experimentals. Classically conditioned specimens were used for avoidance conditioning. Subjects that received aversive electrical stimulation when they did not withdraw from touch rapidly learned to withdraw rather than to feed in response to touch alone. Controls that received touch alone or unpaired touch and shock continued to exhibit the feeding response to touch alone. The learned responses persisted for up to 2 weeks without reinforcement before extinction, and could be demonstrated in the isolated nervous system.

Evaluation of Synchrotron Radiation Integrals

Abstract: Many of the important properties of the stored beam in an electron storage ring are determined by integrals, ’ taken around the whole ring, of various characteristic functions of the guide fielci. Some of the integrals are handled easily, but a few are usually estimated graphically - particularly for alternating-gradient guide fields. This report describes a convenient method for evaluating numerically these recalcitrant integrals. In the usual linear approximation, the integrals we wish to consider are most conveniently expressed in terms of four (somewhat redundant) functions of the azimuthal coordinates: p(s) the radius of curvature of the design orbit, n the field index, F(s) the radial betatro; function andT(s) the off-energy (or “dispersion”) function. The Integrals We restrict our attention to guide fields made up of a number of magnetic segments - magnets or straight sections The functions p and n are assumed to have constant values within a given magnet, but vary abruptly at the entrance and erit boundaries. The integrals of interest are given by:

The origin and turnover of organelle membranes in castor bean endosperm.

Abstract: The origin and turnover of organelle membranes in castor bean (Ricinus communis L. var. Hale) endosperm was examined using choline-(14)C as a phospholipid precursor. On sucrose gradients three major particulate fractions were separated; a light membranous fraction (density 1.11-1.13 gram per cm(3)), the mitochondria (1.18 gram per cm(3)), and the glyoxysomes (1.24 gram per cm(3)). Choline-(14)C was readily incorporated into lecithin in all three particulate fractions, but the light membranous fraction became labeled first. Incorporation continued into all three fractions for 6 hours, at which time the available choline-(14)C had been completely used. Subsequently, (14)C was lost from the three components at distinctly different rates. When an excess of unlabeled choline was added after 1 hour (pulse-chase experiment), incorporation of choline-(14)C into glyoxysomes and mitochondria continued for three hours, but at a diminishing rate. This was followed by a period in which the (14)C content of the mitochondria declined at a rate expected, if the half life of lecithin in the membrane were about 50 hours and that of the glyoxysomes 10 hours. These values are close to those calculated from the experiments in which no chase was used. The labeling in the light membrane fraction behaved differently from that of the mitochondria and glyoxysomes following the chase of unlabeled choline. Incorporation continued for only 1 additional hour, and then the (14)C content declined sharply in the subsequent 4 hours. The early kinetics and subsequent interrelationships are those expected if the lecithin in the membranes of mitochondria and glyoxysomes originates in components of the light membrane fraction.

Development of Enzymes in the Cotyledons of Watermelon Seedlings

Abstract: Changes in hypocotyl length, cotyledon weight, lipid content, chlorophyll content, and capacity for photosynthesis have been described in seedlings of Citrullus vulgaris, Schrad. (watermelon) growing at 30 C under various light treatments. Corresponding changes in the levels of 19 enzymes in the cotyledons are described, with particular emphasis on enzymes of microbodies, since during normal greening, enzymes of the glyoxysomes are lost and those of leaf peroxisomes appear. In complete darkness enzymes of the glyoxysomes reach a peak at 4 days and decline as the fat is depleted. Enzymes of mitochondria and of glycolytic pathways also peak at 4 to 5 days and either remain unchanged or decline to a lesser extent. Exposure to light at 4 days, when the cotyledons emerge, results in a selectively greater destruction of enzymes of the glyoxylate cycle; chlorophyll synthesis and capacity for photosynthesis increase in parallel, and there is a striking increase in the activities of chloroplast enzymes and in those of the leaf peroxisomes, hydroxypyruvate reductase and glycolate oxidase. The reciprocal changes in enzymes of the glyoxysomes and of leaf peroxisomes can be temporally dissociated, since even after 10 days in darkness, when malate synthetase and isocitrate lyase have reached very low levels, hydroxypyruvate reductase and glycolate oxidase increase strikingly on exposure to light and the cotyledons become photosynthetic. Furthermore, the parallel development of enzymes of leaf peroxisomes and functional chloroplasts is not immutable, since hydroxypyruvate reductase and glycolate oxidase activity can be elicited in darkness following a 5-minute exposure to light at day 4 while chlorophyll does not develop under these conditions.

Thermoregulatory Behavior of Eared Seals

Abstract: 1. Thermoregulatory behavior was studied in the Steller sea lion and in the South Australian fur seal during their respective reproductive seasons. Data were gathered using a temperature-sampling technique. 2. The rest postures used by animals of both species were closely correlated with solar radiation (as indicated by rock temperatures). At low temperatures both species used postures that concealed the flippers, thus exposing a minimum of surface area to the air. In addition, sea lions huddled against one another at low temperatures, but fur seals did not. 3. No quantitative species differences existed in behavioral responses to low (10°C) rock temperatures. At intermediate temperatures both species progressively exposed their flippers to the air. At high temperatures (30°C and above) both species resorted to the water for cooling. Female sea lions became wet at temperatures 5°C lower than did fur seals. 4. Fur seal males without direct access to water temporarily abandoned their territories and went to sea at a mean rock temperature of 33°C (approximate solar radiation level between 0.666 and 1.073 cal./cm 2 /min.). 5. Mass movements of females from dry areas across the rookery to the water were temperature-dependent in both species. 6. The behavior of sea lion pups showed less of a direct correlation with temperatures than for their mothers. 7. The social consequences of thermoregulatory behavior were, 1) increased frequency and intensity of sexual investigation by males toward females, 2) an increase by 11% to 15% in aggression among males, and 3) a reduction (by one half) in copulation frequency for males that abandoned their territories to gain access to water for cooling.

Origin of the West Philippine Basin

Abstract: Several alternative modes of development for the West Philippine Basin have been suggested during the past few years. The results of Deep Sea Drilling Project leg 31 indicate that none of these speculations is correct and that the basin probably formed by complex pulses of extension during the early Tertiary. A striking lineament which trends northwest across the basin, variously called the Central Basin Fault or Philippine Ridge, had previously been identified as an extinct spreading ridge of Mesozoic to early Tertiary age. On the contrary, this feature is probably a strike slip fault, possibly with a left-lateral displacement.

Crystallographic orientation of clinoenstatite produced by deformation of orthoenstatite.

Abstract: Uniaxial compression at 800°C and 5 kilobars confining pressure of a specimen cored from a single crystal of orthoenstatite [(Mg,Fe)SiO 3 ] produced fine lamellae 100 to 1000 angstroms thick of untwinned clinoenstatite. The two phases are joined along (100) planes and have b and c axes in common. The orientation of the clinoenstatite a axis contradicts several previously suggested transformation mechanisms and reduces the set of possible mechanisms by a factor of 2.

Biostratigraphic and Geological Significance of Miocene-Pliocene Volcanism in Fiji

Abstract: Dating of Fijian volcanic rocks enables an estimate of 4.9±0.4×106 yr to be made for the age of the Miocene–Pliocene boundary. The change in composition of the volcanism in Fiji between about 5 and 6×106 yr ago may result from migration of the site of subduction.

Complex Deformation of Cretaceous Trench Deposits, Southwestern Alaska

Abstract: A Cretaceous turbidite sequence, a probable trench deposit, forms the central portion of a Triassic to early Tertiary deep-water sedimentary and igneous sequence exposed along the Shumagin-Kodiak shelf, southwestern Alaska. The Cretaceous turbidite sequence was deformed initially in a partially lithified state with the development of axial plane slaty cleavage. Fold axes parallel the existing continental shelf edge, trending northeast and west-northwest in the outer Shumagin and Sanak Islands, respectively. Folds are predominantly overturned seaward, axial surfaces dipping landward. Locally, units may be described as broken formations, though no melanges were observed. The style of this early folding is consistent with, but not diagnostic of, gravity gliding. Alternatively, the rocks may have been deformed by underthrusting at the trench inner wall. At strain rates of 10 −13 to 10 −14 per sec (calculated assuming underthrusting), the trench sediments may have undergone “strain hardening” (caused by increasing internal grain friction and cementation during dewatering) allowing transmission of an externally applied stress. Thick homoclinal sections dip toward the continent, suggesting tilting independent of folding. This tilting was probably associated with uplift along major high-angle faults trending parallel to the continental margin. The early folding, tilting, and uplift was followed by a second, minor, brittle deformation apparently associated with regional granodiorite and quartz diorite intrusions 60 m.y. ago.

Use of Protection of 30S Ribosomal Proteins by tRNA for Functional Mapping of the E. coli Ribosome

Abstract: THE large number of physically and chemically distinct proteins that contribute to the structure of the Escherichia coli ribosome1–5 is in keeping with its many functions which often seem to be attributable to particular protein components of the 30S ribosomal subunit. A complete allocation of functions to specific proteins is vital to an understanding of the mechanism of action of the ribosome in terms of its constituent parts. Several groups6–9 have used tryptic digestion of ribosomal subunits to estimate the relative accessibility of the proteins. We have investigated whether this accessibility can be altered by the presence of bound mRNA or tRNA and describe here some ribosomal proteins from the 30S subunit which have decreased susceptibility to tryptic digestion in these conditions. The involvement of many of these proteins in mRNA and tRNA binding functions, suggested by previous experiments, leads us to propose the use of the technique in the identification of regions of the ribosome to which the various functional ligands are bound during protein synthesis.

German firms in the Western Pacific Islands, 1857–1914

Abstract: from the first successes of Hamburg merchants in the early 1860s to the expropriation of all German property after the First World War. Like Germany's African colonies, the Pacific possessions were of little economic importance to her. Their trade was worth less than one seventh of one per cent of total German trade in 1909, and accumulated capital investment, even by the most optimistic estimates, was not more than M 400,000,000 by 1912, or ?20,000,000 in contemporary sterling.1 The investment was in trading, plantation agriculture and phosphate mining, dominated by a few companies based in Hamburg, Bremen and Berlin, and of minor value to the Fatherland even as a source of raw materials. Copra from Germany's Pacific colonies?their main product?provided less than 8?% of Germany's copra imports in 1910 and 1911 compared to 48^% from British colonies and 40% from the Dutch East Indies.2 Phosphates, the second most im portant export, supplied Germany with 5% of her needs.3 Significant as they were in the economy of the German Pacific, the phosphate islands of Nauru and Angaur produced a mere 3% of the world's phosphate, whereas France's North African colonies?to take a contrasting example?produced 46%.4 With copra, phosphate, birds-of-paradise and cacao the list of sig nificant exports at the end of German rule is exhausted. Economically, Germany's was the smallest of the Pacific colonial empires even after the rapid expansion of the first decade of the 20th century. In 1911 and 1912

"Spiritual education" in a Japanese bank.

Abstract: Many Japanese companies train their new employees according to a philosophy of “spiritualism,” a set of ideas about human psychology and character development that inspired much of the country's pre-war education. “Spiritualism's” debts to the Zen, Confucian and samurai traditions are quite apparent. It emphasizes social cooperation and responsibility, an acceptance of reality, and perseverance. Its educational methods emphasize specially constructed training experiences. As a case study in the anthropology of education, Japanese company spiritual education points to the value of (1) studying educational processes outside formal school systems; (2) considering native concepts of psychology in analyzing educational processes; (3) finding relationships between educational techniques and techniques found in religious conversion, psychological therapy, and social initiation; and (4) discovering avenues of education that proceed by non-verbal means.

An Extracellular Macromolecular Complex from the Surface of Soybean Suspension Cultures

Abstract: A cell-free, insoluble cell wall fraction is described which floats on the surface of suspension cultures of Glycine max L. Merrill var. Acme cells. Its accumulation is governed by both the shaking speed and the medium volume, a shaking speed of 110 to 120 revolutions per minute with a medium volume of about 100 to 120 milliliters in a 250-milliliter flask being optimal. Various factors which could control the accumulation of the complex were tested and are discussed, and scanning electron micrographs of the complex being released from the cell surface are presented. The composition of the complex by weight is 46% galacturonic acid, 36% protein, 11% lignin (apparent), 4.4% arabinose, 2% ash, and 0.5% methyl ester. Evidence for an intimate relationship between the uronic acid and protein fractions is presented. The protein contains hydroxyproline, and the bulk of it is tightly bound to the complex, although a portion can be removed with high salt treatments.

Maternal behavior in the California sea otter.

Abstract: Female sea otters ( Enhydra lutris ) with young observed along the coast from Point Lobos State Park to Lucia, California, spent 8 per cent of their daylight hours nursing their young, 20 per cent grooming their young, 10 per cent grooming themselves, 16 per cent feeding, 13 per cent swimming and 41 per cent resting. Nursing was always simultaneous with resting or with grooming of the pup. Females nursed their young an average of six times per day and each bout lasted about 9 minutes. The mean duration of food dives by females with young was 52 seconds. The peak period of birth was from December to February. Postpartum behavior of one female is described.

A Double Quasistellar Object

Abstract: It is reported that 1548+115a is also a QSO Spectral information is provided for 1548+115b and 1548+115a, giving attention to the very different redshifts of the objects The observations reported are believed to add support to noncosmological theories of redshifts Such theories will receive additional support if an interaction between the two components of a close pair can be shown

A double quasistellar object.

Abstract: It is reported that 1548+115a is also a QSO. Spectral information is provided for 1548+115b and 1548+115a, giving attention to the very different redshifts of the objects. The observations reported are believed to add support to noncosmological theories of redshifts. Such theories will receive additional support if an interaction between the two components of a close pair can be shown.

Redshift of OQ172

Abstract: Comments on a recently discovered second QSO with a redshift greater than 3. From a study of a composite spectrum of OQ172 formed by adding data from spectra obtained on different nights two strong emission features near 5540 and 7015 A are noted and are identified with Lyman alpha 1216 A and CIV 1549 A. The measured wavelength of the emission peaks corresponds to a redshift of 3.56 for Lyman alpha and 3.53 for CIV. It is concluded that the emission line redshift of OQ172 is near 3.53.

An evolutionary and ecological perspective of Amazonian Hylaea species of Hymeneae (Leguminosae: Caesalpinioideae)

Abstract: The resin-producing genus Hymenaea has an amphi-Atlantic distribution with 13 species being Neotropical and one occurring along the eastern coast of Africa. Present evidence suggests an African origin for the genus with migration across the Atlantic occurring during the Early Tertiary when the continents were closer and rainforest vegetation was considerably more widely distributed than today. The center of its Neotropical distribution is the Amazonian hylaea, although within its extensive range from 23° N to 26° S it is found in all major ecosystem types. The taxonomy, breeding structure, ecology and resin chemistry of the 9 Hymenaea species and 6 varieties occurring in the Amazonian and historically-related Brazilian Atlantic coastal humid evergreen forests are discussed as well as the possible evolution of these species in response to postulated drying trends beguen in Mid Tertiary times and during wet-dry oscillations in the Pleistocene.