Showing papers by "University of California, San Diego published in 1980"
TL;DR: In a sentence reading task, words that occurred out of context were associated with specific types of event-related brain potentials that elicited a late negative wave (N400).
Abstract: In a sentence reading task, words that occurred out of context were associated with specific types of event-related brain potentials. Words that were physically aberrant (larger than normal) elecited a late positive series of potentials, whereas semantically inappropriate words elicited a late negative wave (N400). The N400 wave may be an electrophysiological sign of the "reprocessing" of semantically anomalous information.
4,226 citations
TL;DR: Generation and estimation of these models are considered and applications on generated and real data presented, showing potentially useful long-memory forecasting properties.
Abstract: . The idea of fractional differencing is introduced in terms of the infinite filter that corresponds to the expansion of (1-B)d. When the filter is applied to white noise, a class of time series is generated with distinctive properties, particularly in the very low frequencies and provides potentially useful long-memory forecasting properties. Such models are shown to possibly arise from aggregation of independent components. Generation and estimation of these models are considered and applications on generated and real data presented.
3,250 citations
TL;DR: The results indicate that the class of preserved learning skills in amnesia is broader than previously reported and support the hypothesis that such a distinction is honored by the nervous system.
Abstract: Amnesic patients acquired a mirror-reading skill at a rate equivalent to that of matched control subjects and retained it for at least 3 months. The results indicate that the class of preserved learning skills in amnesia is broader than previously reported. Amnesia seems to spare information that is based on rules or procedures, as contrasted with information that is data-based or declarative--"knowing how rather than "knowing that." The results support the hypothesis that such a distinction is honored by the nervous system.
2,204 citations
TL;DR: In this paper, a general definition of causality is introduced and then specialized to become operational, and tests based on the definitions are then considered and the use of post-sample data emphasized rather than relying on the same data to fit a model and use it to test causality.
1,574 citations
TL;DR: Evidence is presented that PGPR exert their plant growth-promoting activity by depriving native microflora of iron by producing extracellular siderophores (microbial iron transport agents) which efficiently complex environmental iron, making it less available to certain nativemicroflora.
Abstract: Specific strains of the Pseudomonas fluorescens-putida group have recently been used as seed inoculants on crop plants to promote growth and increase yields. These pseudomonads, termed plant growth-promoting rhizobacteria (PGPR), rapidly colonize plant roots of potato, sugar beet and radish, and cause statistically significant yield increases up to 144% in field tests1–5. These results prompted us to investigate the mechanism by which plant growth was enhanced. A previous study indicated that PGPR increase plant growth by antagonism to potentially deleterious rhizoplane fungi and bacteria, but the nature of this antagonism was not determined6. We now present evidence that PGPR exert their plant growth-promoting activity by depriving native microflora of iron. PGPR produce extracellular siderophores (microbial iron transport agents)7 which efficiently complex environmental iron, making it less available to certain native microflora.
1,492 citations
TL;DR: The hypothesis that some reading impairments are related to low-level auditory perceptual dysfunction that affects the ability to learn to use phonics skills adequately is discussed.
1,469 citations
TL;DR: In this paper, the solubility of nitrous oxide in pure water and seawater has been measured microgasometrically over the range 0 −40°C and the data have been corrected for nonideality and are fitted to equations in temperature and salinity of the form used previously to fit solubilities of other gases.
1,402 citations
1,142 citations
Book•
01 Jan 1980TL;DR: Flow patterns and wall shear stress in arteries I Straight tubes and flow instability, and flow in collapsible tubes.
Abstract: 1. Physiological introduction 2. Propagation of the pressure pulse 3. Flow patterns and wall shear stress in arteries I Straight tubes 4. Flow patterns and wall shear stress in arteries II. Curved tubes 5. Flow patterns and wall shear stress in arteries III. Branched tubes and flow instability 6. Flow in collapsible tubes.
1,048 citations
932 citations
TL;DR: In all three regions studied, it appeared that a significant fraction of the total primary production was utilized by the bacterioplankton and that substantial growth could occur in the absence of large particles.
Abstract: The principal objective of this study was to quantify the rate of heterotrophic bacterioplankton production. Production was estimated by two approaches: (i) measurement of increasing bacterial abundance with time in filtered (3-μm pore size) seawater and (ii) estimation of bacterial deoxyribonucleic acid synthesis by tritiated thymidine incorporation in unfractionated seawater. The two approaches yielded comparable results when used at the Controlled Ecosystem Population Experiment (Saanich Inlet, British Columbia, Canada), at McMurdo Sound (Antarctica), and off Scripps Pier (La Jolla, Calif.). Estimated bacterioplankton production was lower in Antarctic samples (ranging from ∼0 to 2.9 μg of C liter−1 day−1) than in those from the other two sites (ranging from 0.7 to 71 μg of C liter−1 day−1). In all three regions studied, it appeared that a significant fraction of the total primary production was utilized by the bacterioplankton and that substantial growth could occur in the absence of large particles. These results support the conclusion that bacterioplankton are a quantitatively important component of coastal marine food webs.
TL;DR: Current evidence regarding the basis for the dysfunction of ovarian steroidogenesis and follicular maturation, and the aberration of gonadotropin secretion as related to the inappropriate steroid feedback system will be reviewed.
Abstract: An extensive literature dealing with studies on the pathophysiology of the polycystic ovary syndrome (PCO) has accumulated over the years. The great clinical and biochemical variability of PCO, as indicated in several excellent reviews over a decade ago (Goldzieher & Axelrod, 1963; Mahesh & Greenblatt, 1964; Jeffcoate, 1963; Shearman & Cox, 1966), continues as a major problem in defining this syndrome. Further, the pathogenesis of this reversible disorder remains elusive. However, recent advances in our understanding of ovarian physiology, the pathways for androgen-oestrogen secretion and metabolism, and the integrated function of the hypothalamic-hypophyseal-ovarian axis permit a rational description of the pathophysiology of the PCO syndrome. Thus, current evidence regarding the basis for the dysfunction of ovarian steroidogenesis and follicular maturation, and the aberration of gonadotropin secretion as related to the inappropriate steroid feedback system will be reviewed. The long debated issue of the possible role of adrenal androgen in the genesis and persistence of PCO syndrome will also be considered.
TL;DR: A chemical model of the seawater system, NaK,Mg,Ca,Cl,SO 4,H 2 O, was developed for predicting mineral solubilities in brines from zero to high ionic strengths as discussed by the authors.
TL;DR: High-resolution determinations of crustal properties along the spreading center were made to gain knowledge of the source of new oceanic crust and marine magnetic anomalies, the nature of the axial magma chamber, and the depth of hydrothermal circulation.
Abstract: Hydrothermal vents jetting out water at 380° ± 30°C have been discovered on the axis of the East Pacific Rise. The hottest waters issue from mineralized chimneys and are blackened by sulfide precipitates. These hydrothermal springs are the sites of actively forming massive sulfide mineral deposits. Cooler springs are clear to milky and support exotic benthic communities of giant tube worms, clams, and crabs similar to those found at the Galapagos spreading center. Four prototype geophysical experiments were successfully conducted in and near the vent area: seismic refraction measurements with both source (thumper) and receivers on the sea floor, on-bottom gravity measurements, in situ magnetic gradiometer measurements from the submersible Alvin over a sea-floor magnetic reversal boundary, and an active electrical sounding experiment. These high-resolution determinations of crustal properties along the spreading center were made to gain knowledge of the source of new oceanic crust and marine magnetic anomalies, the nature of the axial magma chamber, and the depth of hydrothermal circulation.
TL;DR: It is considered that cryoultramicrotomy has reached the stage of being useful in studying many questions which will not be easily approached otherwise, and is considered to be useful for immunochemical localization of intracellular antigens.
Abstract: Ultrathin frozen sections can be cut smoothly from many fixed and appropriately treated specimens. To use such sections for immunochemical localization of intracellular antigens, fixa ion conditions must be selected to optimize at least three variables, namely, preservation of ultrastructure, preservation of antigenicity and retention of accessibility of the antigen to the antibody. Furthermore, staining of the sections must be such that both the immunolabels and structures are clearly recognized. Our efforts to attain these goals are described in relation to their historical background. Although there are still problems to be solved and improvements to be made, we now consider that cryoultramicrotomy has reached the stage of being useful in studying many questions which will not be easily approached otherwise.
TL;DR: Plasma BGP was increased in patients with Paget's disease of bone, bone metastases, primary hyperparathyroidism, renal osteodystrophy, and osteopenia and it was observed that patients with liver disease had normal plasma BGP despite increased plasma AP, a reflection of the lack of specificity of AP measurements for bone disease.
Abstract: gamma-Carboxyglutamic acid-containing protein of bone (BGP) is an abundant noncollagenous protein of mammalian bone. BGP has a molecular weight of 5,800 and contains three residues of the vitamin K-dependent amino acid, gamma-carboxyglutamic acid. We have applied a radioimmunoassay based on calf BGP for the measurement of the protein in the plasma of 109 normal humans and 112 patients with various bone diseases. BGP in human plasma was demonstrated to be indistinguishable from calf BGP by assay dilution studies and gel permeation chromatography. The mean (+/- SE) concentration of BGP in normal subjects was 6.78 (+/- 0.20) ng/ml, 7.89 (+/- 0.32) for males and 4.85 (+/- 0.35) for females. Plasma BGP was increased in patients with Paget's disease of bone, bone metastases, primary hyperparathyroidism, renal osteodystrophy, and osteopenia. Plasma BGP did correlate with plasma alkaline phosphatase (AP) in some instances, but there were dissociations between the two. It was additionally observed that patients with liver disease had normal plasma BGP despite increased plasma AP, a reflection of the lack of specificity of AP measurements for bone disease. Our studies indicate that the radioimmunoassay of plasma BGP can be a useful and specific procedure for evaluating the patient with bone disease.
TL;DR: It was concluded that the effect of selective auditory attention on the N1 component is not due solely to an enlargement of the exogenous N1 components of the vertex potential, but rather includes the addition of a prolonged endogenous component.
TL;DR: It was found that the ERPs elicited by the words during the reading condition were characterized by a left-greater-than-right asymmetry in a slow, positive component, most pronounced for right-handed subjects having not left-handers in their immediate family.
TL;DR: These findings suggest that disease suppressiveness is caused in part by microbial siderophores which efficiently complex iron(III) in soils, making it unavailable to pathogens, thus inhibiting their growth.
Abstract: The addition of either fluorescentPseudomonas strain B10, isolated from a take-all suppressive soil, or its siderophore, pseudobactin, to bothFusarium-wilt and take-all conducive soils inoculated withFusarium oxysporum f. sp.lini orGaeumannomyces graminis var.tritici, respectively, rendered them disease suppressive. Our findings suggest that disease suppressiveness is caused in part by microbial siderophores which efficiently complex iron(III) in soils, making it unavailable to pathogens, thus inhibiting their growth. Amendment of exogenous iron(III) to disease-suppressive soils converted them to conductive soils presumably by repressing siderophore production.
TL;DR: In this article, it is argued that a sound and natural approach to such tests must rely primarily on the out-of-sample forecasting performance of models relating the original (non-prewhitened) series of interest.
Abstract: This paper is concerned with testing for causation, using the Granger definition, in a bivariate time-series context. It is argued that a sound and natural approach to such tests must rely primarily on the out-of-sample forecasting performance of models relating the original (non-prewhitened) series of interest. A specific technique of this sort is presented and employed to investigate the relation between aggregate advertising and aggregate consumption spending. The null hypothesis that advertising does not cause consumption cannot be rejected, but some evidence suggesting that consumption may cause advertising is presented.
TL;DR: The extraOSseous and intraosseous vascularity of the carpal scaphoid was studied in 15 fresh cadaver specimens by injection and clearing techniques and an explanation for the cause of scaphoids necrosis on the basis of the vascular anatomy is proposed.
Abstract: The extraosseous and intraosseous vascularity of the carpal scaphoid was studied in 15 fresh cadaver specimens by injection and clearing techniques. The major blood supply to the scaphoid is via the radial artery. Seventy to eighty percent of the intraosseous vascularity and the entire proximal pole is from branches of the radial artery entering through the dorsal ridge. Twenty to thirty percent of the bone, in the region of the distal tuberosity, receives its blood supply from volar radial artery branches. There is an excellent collateral circulation to the scaphoid by way of the dorsal and volar branches of the anterior interosseous artery. An explanation for the cause of scaphoid necrosis on the basis of the vascular anatomy is proposed. The volar operative approach would be least traumatic to the proximal pole's blood supply.
01 Dec 1980-Journal of Comparative Physiology A-neuroethology Sensory Neural and Behavioral Physiology
TL;DR: Post-dive arterial lactic acid concentrations were at no time different from resting levels unless the previous dive exceeded 20 to 25 min, while blood gases were in the normal mammalian range, but based upon resting apneic values may drop to remarkably low levels during prolonged dives.
Abstract: The salient features of this study in the order of significance as we perceive them are: 1. Post-dive arterial lactic acid concentrations were at no time different from resting levels unless the previous dive exceeded 20 to 25 min (Fig. 5). 2. Peak lactate concentration was correlated to dive durations (Fig. 6). 3. Only 2.7% of the dives of free-ranging seals exceed 26 min (Table 3 and Fig. 7). 4. There was a notable drop in body temperature during prolonged dives to as low as 34.9 ~ (Table 2). 5. Arterial hemoglobin concentrations immediately after dives (22.7 g%) were significantly higher than concentrations in resting animals (17.4g%) (Fig. 3). 6. Blood glucose after dives always rose above resting levels. 7. pH was in the normal mammalian range except after very long dives; in these cases the pH fell as low as 6.8 (Fig. 4). 8. Blood gases were in the normal mammalian range, but based upon resting apneic values Pao2 may drop to remarkably low levels during prolonged dives.
TL;DR: Studies with peptides of known structure derived from enzymatic digests of BGP indicate that the rabbit antibody recognizes the COOH-terminal region of the 49-residue calf bone protein.
Abstract: The vitamin K-dependent protein of bone has been detected in human plasma by radioimmunoassay at 4.5 ng per ml. The plasma protein has the same apparent molecular weight as the pure bone Gla protein (BGP) and other studies indicate the plasma protein is probably the intact bone protein. BGP also has been detected in bovine serum by radioimmunoassay. The bovine serum levels of BGP decrease with developmental age from 200 ng per ml in fetal calves to 26 ng per ml in adult cows. The implications of the discovery of BGP in plasma to the function of this unique protein are discussed. This assay employs rabbit antibody directed against calf BGP and has a sensitivity of 0.1 ng. The antibody crossreacts with purified human BGP but not with BGP from rat or rabbit bone. Studies with peptides of known structure derived from enzymatic digests of BGP indicate that the rabbit antibody recognizes the COOH-terminal region of the 49-residue calf bone protein.
TL;DR: The noradrenaline (NA)‐containing innervation of the hippocampal formation arises exclusively in the brainstem nucleus locus coeruleus, and the endogenous content of NA is greater in the area dentata than in Ammon's horn, and in both structures is more in the temporal than in the septal ends.
Abstract: The noradrenaline (NA)-containing innervation of the hippocampal formation arises exclusively in the brainstem nucleus locus coeruleus. The projection is 75--90% ipsilateral, originating predominantly in the large, multipolar cells of the compact component of the nucleus. The axons course into the hippocampal formation by three pathways. Ammon's horn receives its NA innervation principally through the ventral amygdaloid bundle-ansa peduncularis, with smaller contributions from the fornix and ipsilateral fasciculus cinguli. The innervation of the area dentata is to a larger extent bilateral, with the greatest contribution arising from the ipsilateral fasciculus cinguli and approximately equal proportions of fibers traveling via the contralateral cingulum, fornix, and the ventral path. In general, the endogenous content of NA is greater in the area dentata than in Ammon's horn, and in both structures is greater in the temporal than in the septal ends. The pattern of NA innervation is similar at all septotemporal levels, however. The dense plexuses of preterminal and terminal elements appear in the infragranular hilus of the area dentata, stratum lucidum of CA3, and in the molecular layer of the subiculum. Fluorescent varicosities often appear in perisomatic clusters, or, closely apposed to dendrites of granule and pyramidal cells.
TL;DR: The ability to generate cultures of pure neurons in a serum-free defined medium may be useful for studying (i) the role of specific hormones and growth factors normally supplied by serum in the maintenance of neurons and (ii) biochemical parameters of neurons in the absence of the substantial background due to non-neuronal elements.
TL;DR: In this paper, the generation of nuclear magnetic double quantum echoes and their detection by two-dimensional Fourier transform spectroscopy was reported for partially aligned one-deuteron systems in a nematic liquid crystal.
TL;DR: In this article, the one-dimensional quantum spin-\textonehalf{} Heisenberg antiferromagnetic model with randomly distributed interaction strengths is solved approximately for several different distributions.
Abstract: The one-dimensional quantum spin-\textonehalf{} Heisenberg antiferromagnetic model with randomly distributed interaction strengths is solved approximately for several different distributions. Ground-state energy and low-temperature properties are evaluated. Universal qualitative features are found in the specific heat and the magnetic susceptibility, which display a power-law dependence on temperature. Such features hold for nonsingular distributions as well as for distributions with power-law divergence at the origin. The approximate method of solution is based on successive eliminations of spins coupled by the maximum coupling constant.
TL;DR: Exposing the toxin to an acidic environment, such as that found within lysosomes, is an important step in the penetration of diphtheria toxin into the cytoplasm.
Abstract: Lysosomotropic amines, such as ammonium chloride, are known to protect cells from the cytotoxic effects of diphtheria toxin. These drugs are believed to inhibit the transport of the toxin from a receptor at the cell exterior into the cytoplasm where a fragment of the toxin arrests protein synthesis. We studied the effects of lysosomotropic agents on the cytotoxic process to better understand how the toxin enters the cytoplasm. The cytotoxic effects of diphtheria toxin were not inhibited by antitoxin when cells were preincubated at 37 degrees C with toxin and ammonium chloride, exposed to antitoxin at 4 degrees C, washed to relieve the ammonium chloride inhibition, and finally warmed to 37 degrees C. The antigenic determinants of the toxin were, therefore, either altered or sheltered. It is likely that the combination of ammonium chloride and a low temperature trapped the toxin in an intracellular vesicle from which the toxin could proceed to the cytoplasm. Because lysosomotropic amines raise the pH within acidic intracellular vesicles, such as lysosomes, they could trap the toxin within such a vesicle if an acidic environment were necessary for the toxin to penetrate into the cytoplasm. We simulated acidic conditions which the toxin might encounter by exposing cells with toxin bound to their surface to acidic medium. We then measured the effects of lysosomotropic amines on the activity of the toxin to see if the acidic environment substituted for the function normally inhibited by the drugs. The drugs no longer protected the cells. This suggests that exposing the toxin to an acidic environment, such as that found within lysosomes, is an important step in the penetration of diphtheria toxin into the cytoplasm.
TL;DR: This paper found that the traditional distinction between literal and metaphoric language is better characterized as a continuum between conventional and unconventional utterances, and that subjects understand the idiomatic meaning of these expressions before deriving the literal, unconventional interpretation.
Abstract: Three experiments examine people's understanding and memory for idioms. Experiment 1 indicates that in a conversational context, subjects take less time to comprehend conventional uses of idiomatic expression than unconventional, literal uses. Paraphrase judgment errors show that there is a strong bias to interpret idiomatic expressions conventionally when there is no preceding context; however, subjects interpret literal uses of these expressions correctly when there is appropriate context. Experiment 2 showed that in a free recall task, literal uses of idioms are remembered better than conventional uses of these utterances. Experiment 3 indicated that in conversation, literal and idiomatic recall prompts facilitate memory for literal uses of idioms equally well. The results from these experiments suggest that memory for conventional utterances is not as good as for unconventional uses of the same utterances and that subjects understanding unconventional uses of idioms tend to analyze the idiomatic meaning of these expressions before deriving the literal, unconventional interpretation. It is argued that the traditional distinction between literal and metaphoric language is better characterized as a continuum between conventional and unconventional utterances.
TL;DR: It is shown that the tra, tra-2 and dsx loci determine sex in a cell-autonomous manner and are major regulatory loci that control the batteries of genes necessary for the development of many, and perhaps all, secondary sexual characteristics.
Abstract: Sex determination in Drosophila melanogaster is under the control of the X chromosome:autosome ratio and at least four major regulatory genes: transformer (tra), transformer-2 (tra-2), doublesex (dsx) and intersex (ix). Attention is focused here on the roles of these four loci in sex determination. By examining the sexual phenotype of clones of homozygous mutant cells produced by mitotic recombination in flies heterozygous for a given recessive sex-determination mutant, we have shown that the tra, tra-2 and dsx loci determine sex in a cell-autonomous manner. The effect of removing the wild-type allele of each locus (by mitotic recombination) at a number of times during development has been used to determine when the wild-type alleles of the tra, tra-2 and dsx loci have been transcribed sufficiently to support normal sexual development. The wild-type alleles of all three loci are needed into the early pupal period for normal sex determination in the cells that produce the sexually dimorphic (in pigmentation) cuticle of the fifth and sixth dorsal abdominal segments. tra(+) and tra-2(+) cease being needed shortly before the termination of cell division in the abdomen, whereas dsx(+) is required at least until the end of division. By contrast, in the foreleg, the wild-type alleles of tra(+) and tra-2(+) have functioned sufficiently for normal sexual differentiation to occur by about 24 to 48 hours before pupariation, but dsx(+) is required in the foreleg at least until pupariation.--A comparison of the phenotypes produced in mutant/deficiency and homozygous mutant-bearing flies shows that dsx, tra-2 and tra mutants result in a loss of wild-type function and probably represent null alleles at these genes.-All possible homozygous doublemutant combinations of ix, tra-2 and dsx have been constructed and reveal a clear pattern of epistasis: dsx > tra, tra-2 > ix. We conclude that these genes function in a single pathway that determines sex. The data suggest that these mutants are major regulatory loci that control the batteries of genes necessary for the development of many, and perhaps all, secondary sexual characteristics.-The striking similarities between the properties of these loci and those of the homeotic loci that determine segmental and subsegmental specialization during development suggest that the basic mechanisms of regulation are the same in the two situations. The phenotypes and interactions of these sex-determination mutants provide the basis for the model of how the wild-type alleles of these loci act together to effect normal sex determination. Implications of these observations for the function of other homeotic loci are discussed.