Showing papers by "University of California, San Diego published in 1974"
TL;DR: In this paper, the solubility coefficients for carbon dioxide in water and seawater are calculated for the data of Murray and Riley, and are fitted to equations in temperature and salinity of the form used previously to fit solubilities of other gases.
2,788 citations
TL;DR: In this article, order α6mc2 corrections to the fine structure splitting of the He4 atom were investigated based on the covariant Bethe-Salpeter equation including external potential to take account of the nuclear Coulomb field.
2,455 citations
TL;DR: In this article, a step-by-step computer algorithm of the revised version of the original Little Jiffy, Mark IV, is presented, with the index of the covariance matrix (with zero in the diagonal) under consideration.
Abstract: IN this paper three changes and one new development for the method of exploratory factor analysis (a second generation Little Jiffy) developed by Kaiser (1970) are described. Following this short description a step-by-step computer algorithm of the revised method-dubbed Little Jiffy, Mark IV-is presented. Extensive empirical experience with &dquo;a second generation Little Jiffy&dquo; (Kaiser, 1970) indicates that the method, for large matrices, consistently mildly underfactors. A revision is called for. Thus, the writers adopt as the answer for the crucially important question of the &dquo;number of factors&dquo; Guttman’s (1954) classic weaker lower bound, the index of the covariance matrix (with zeros in the diagonal) under consideration. This answer is the same as that given by Kaiser’s (1956, 1960, 1970) extensively used &dquo;eigenvalues greater than one of R.&dquo;
2,161 citations
TL;DR: Fifteen distinct components can be identified in the scalp recorded average evoked potential to an abrupt auditory stimulus, and seem to represent widespread activation of frontal cortex.
1,316 citations
Book•
01 Jan 19741,051 citations
TL;DR: Evidence shows that human auditory attention is not mediated by a peripheral gating mechanism and that attention directed toward auditory stimuli causes a substantial increase in the N1 and P2 components of the auditory evoked potential without any change in preceding components.
804 citations
TL;DR: In this article, a self-consistent model of instantaneous relative motions for eleven major plates is presented, assuming that the lithospheric plates to be rigid, and the authors systematically invert 68 spreading rates, 62 fracture zones trends and 10^6 earthquake slip vectors simultaneously to obtain a self consistent model.
Abstract: Assuming lithospheric plates to be rigid, we systematically invert 68 spreading rates, 62 fracture zones trends and 10^6 earthquake slip vectors simultaneously to obtain a self-consistent model of instantaneous relative motions for eleven major plates. The inverse problem is linearized and solved iteratively by a maximum likelihood procedure. Because the uncertainties in the data are small, Gaussian statistics are shown to be adequate. The use of a linear theory permits (1) the calculation of the uncertainties in the various angular velocity vectors caused by uncertainties in the data, and (2) quantitative examination of the distribution of information within the data set.
The existence of a self-consistent model satisfying all the data is strong justification of the rigid plate assumption. Slow movement between North and South America is shown to be resolvable.
We then invert the trends of 20 linear island chains and aseismic ridges under the assumptions that they represent the directions of plate motions over a set of hot spots fixed with respect to each other. We conclude that these hot spots have had no significant relative motions in the last 10 My.
746 citations
TL;DR: The results indicate the power of this approach, which provides continuous quantification of regional wall function in myocardial ischemia and during therapeutic interventions, and suggests a protective effect of this drug.
Abstract: Myocardial regional function during acute coronary artery occlusion was studied using ultrasonic dimension gauges in open-chest dogs. Three pairs of 2-mm ultrasonic crystals were implanted 1 cm apart near the endocardium in an ischemic segment, a control segment, and a segment at the margin of the ischemic zone. In the ischemic segment, coronary artery occlusion resulted in prompt dyskinesis which progressed to holosystolic expansion; length at enddiastole (diastolic length) increased by 11%, segment stroke work decreased by 91%, and the diastolic pressure-length relationship was displaced and steepened. In the marginal segment, active shortening and stroke work decreased by 37% and diastolic length increased by 4%. In the control segment, an initial increase in active shortening was observed, followed by compensatory operation of the Frank-Starling mechanism. Nitroglycerin administered during coronary artery occlusion decreased diastolic length and increased shortening in all three segments. An early beneficial effect of isoproterenol on all segments was later replaced by deterioration in marginal and ischemic segments. After propranolol administration, the decrease in shortening of the marginal segment was reduced to half of that observed during a control coronary artery occlusion, suggesting a protective effect of this drug. These results indicate the power of this approach, which provides continuous quantification of regional wall function in myocardial ischemia and during therapeutic interventions.
739 citations
TL;DR: BACTERIAL flagella are generally composed of three morphologically distinguishable regions: the long flagellar filament, the hook, and the basal structure which is composed of an intricate set of disks and rods attaching the hook to the cell membrane and cell wall.
Abstract: BACTERIAL flagella are generally composed of three morphologically distinguishable regions: (a) the long flagellar filament which accounts for more than 95% of the flagellar protein; (b) the hook, which is generally 80–90 nm long and has a characteristic shape, and (c) the basal structure which is composed of an intricate set of disks and rods attaching the hook to the cell membrane and cell wall1–3.
685 citations
TL;DR: The superconducting phase transition is predicted to be weakly first order, because of effects of the intrinsic fluctuating magnetic field, according to a Wilson-Fisher $\ensuremath{\epsilon}$expansion analysis, as well as a generalized mean-field calculation appropriate to a type-I superconductor.
Abstract: The superconducting phase transition is predicted to be weakly first order, because of effects of the intrinsic fluctuating magnetic field, according to a Wilson-Fisher $\ensuremath{\epsilon}$-expansion analysis, as well as a generalized mean-field calculation appropriate to a type-I superconductor. Similar results hold for the phase transition from a smectic-$A$ to a nematic liquid crystal.
653 citations
TL;DR: carry-over of both the post-injection augmentation and dark phase reduction of locomotion was revealed during amphetamine retest 8 days following discontinuation of daily d-amphetamine injections, indicating the importance of their concurrent evaluation, especially during chronic studies.
Abstract: The competitive relationship between d-amphetamine induced stereotypy and locomotor activity indicates the importance of their concurrent evaluation, especially during chronic studies. Repeated injection of 0.5, 1.0, 2.5, 5.0, or 7.5 mg/kg d-amphetamine for 36 successive days, in rats continuously exposed to the experimental chambers, produced a progressive augmentation in stereotypy and/or locomotion (depending on dose) during the 3–4 hr interval following injections (post-injection phase). In contrast, dark phase locomotor activity (8–20 hr after each daily injection) was maximally reduced (30–40% of controls) after the first injection of either 5.0 or 7.5 mg/kg d-amphetamine and gradually declined to this level with repeated injection of 1.0 and 2.5 mg/kg. Carry-over of both the post-injection augmentation and dark phase reduction of locomotion was revealed during amphetamine retest 8 days following discontinuation of daily d-amphetamine injections. Possible mechanisms underlying these behavioral alterations are discussed.
TL;DR: In this article, the authors measured ocean surface currents using both a conventional and the HF technique, and reasonable agreement was found with respect to the phase velocity of the wave in still water, c = √(g/k).
TL;DR: The postmenopausal ovary continues to secrete a large amount of testosterone and a moderate amount of androstenedione and the small magnitude of the peripheral and ovarian vein estrogen differences could account for only minimal ovarian estrogen secretion.
Abstract: The concentrations of testosterone, androstenedione, 17β-estradiol, and estrone were measured in peripheral and ovarian vein sera obtained at the time of surgery from 10 postmenopausal women undergoing bilateral oophorectomy. A higher ovarian than peripheral vein concentration was found for all hormones studied. The differences between ovarian and peripheral vein concentrations were 15-fold for testosterone (3033 ± 1046 pg/ml vs 198 ± 27 pg/ml, p <0.01); 4-fold for androstenedione (3455 ± 1330 pg/ml vs 754 ± 174 pg/ml, NS) and 2-fold for both 17β-estradiol (31.1 ± 6.3 pg/ml vs 14.6 ± 2.9 pg/ml, p < 0.05); and estrone (71.5 ± 13.3 pg/ml vs 30.3 ± 3.4 pg/ml, p < 0.05). It is concluded that the postmenopausal ovary continues to secrete a large amount of testosterone and a moderate amount of androstenedione. The small magnitude of the peripheral and ovarian vein estrogen differences could account for only minimal ovarian estrogen secretion.
TL;DR: The meridional Ninetyeast Ridge in the eastern Indian Ocean separates the deep Central Indian Basin from the deeper Wharton Basin (or Cocos Basin-West Australian Basin) to the east as discussed by the authors.
Abstract: The meridional Ninetyeast Ridge in the eastern Indian Ocean separates the deep Central Indian Basin from the deeper Wharton Basin (or Cocos Basin–West Australian Basin) to the east. The flattish-summited ridge extends slightly east of north from near 32° S. directly to 7° S. where it appears segmented as a series of en echelon northeast-southwest–trending highs, then in a northerly direction disappears beneath the sediments of the Bengal Fan system near 9° N. Linear parallel to subparallel troughs border this linear ridge on the east side; on the west, from results of magnetic observations and preliminary deep drilling information, Ninetyeast Ridge apparently is bonded to the Indian plate. A second extensive north-south topographic rise and magnetic boundary zone, herein named the Investigator Fracture Zone, lies near 98° E. in the Wharton Basin. Easterly trending magnetic-anomaly lineations identified as numbers 5 through 16 and numbers 21 through 33b, increasing in age northward and with spreading rates variable through time, have been recognized in the Central Indian Basin. East of Ninetyeast Ridge in the Wharton Basin, anomalies 19 through 27, with spreading rates varying in concert with those of comparable age west of the ridge, have been found to increase in age toward the south. Older anomalies 28 through 33 have been identified in both basins; their divergent trends provide evidence that spreading rates decrease markedly westward during the time span they cover in the Late Cretaceous. From deep-sea drilling information supplementing and supporting magnetic, topographic, and gravity data obtained principally by research ships and PROJECT MAGNET since 1962, we interpret Ninetyeast Ridge to be an extrusive pile with a low-density shallow root, rather than a horst or an uplift resulting from the convergence of plates. The trough system that is partially buried with sediment east of the ridge and the north-south Investigator Fracture Zone several hundred kilometers farther to the east are remnants of formerly active transform faults that marked huge relative offsets between the spreading centers separating the Indian and Antarctic-Australian plates from anomaly 33b (Late Cretaceous) to anomaly 19 (Eocene) time. During the Late Cretaceous, Ninetyeast Ridge and Chagos-Laccadive Ridge had similar settings, marking paired offsets of an active spreading center around the southern tip of India. Both features terminated as active transform faults with the cessation of north-south spreading and the commencement of northeast-southwest spreading close to the time of anomaly 11 (Oligocene). The here-interpreted oceanic data is strong but not conclusive support for fitting India to Enderby Land in Antarctica in the Early Cretaceous. With presently available information, we have been unable to establish the precise time at which the spreading center in the Wharton Basin ceased to function.
TL;DR: It is found that calcium ionophore activation is common to several species widely separated phylogenetically and has not been obtained with Acmaea and Ciona eggs by other methods.
Abstract: WE have previously exposed sea urchin eggs to micromolar amounts of the divalent transporting ionophore A23187, and observed every parameter of normal fertilisation. The cortical reaction with elevation of the fertilisation membrane, the plasma membrane conductance changes, the respiratory burst, and increases in protein and DNA synthesis were all initiated in the usual fashion1. These activations of Lytechinus pictus and Strongylocentrotus purpuratus eggs were independent of the ionic composition of the external solutions1. A23187 seemed to act by releasing intracellular Ca2+, for eggs preloaded with 45Ca showed a twentyfold increase in 45Ca-efflux when activated by ionophore or fertilisation1. Measurements of free and bound calcium and magnesium in homogenates of unfertilised eggs showed that most of the Mg2+ was already available in soluble form, whereas the Ca2+ was sequestered but available for release1. After we found that 50 µM A23187 could activate eggs of the mollusc Acmaea insessa and the protochordate Ciona intestinalis to undergo several abnormal cleavages, we wondered whether ionophore activation might be a general phenomenon. To our knowledge artificial parthenogenesis has not been obtained with Acmaea and Ciona eggs by other methods. We have now found that calcium ionophore activation is common to several species widely separated phylogenetically.
TL;DR: In this paper, the authors generalized the renormalization-group method for studying critical phenomena to a class of dynamical systems, the time-dependent Ginzburg-Landau models.
Abstract: The renormalization-group method for studying critical phenomena is generalized to a class of dynamical systems---the time-dependent Ginzburg-Landau models. The effects of conservation laws on the critical dynamics are investigated through the study of models with different conservation properties for the energy and the space integral of the order parameter. Dynamic critical exponents near four dimensions ($d\ensuremath{\approx}4$) are obtained from recursion relations, analogous to those of Wilson and Fisher. The physical significance of the time-dependent Ginzburg-Landau models is explored and the applicability of the results to experiments on the NMR linewidth of Fe${\mathrm{F}}_{2}$ is discussed.
TL;DR: Computer studies show that stable patterns occur spontaneously in Systems of pacemaker neurons with PIR, and can be triggered in systems of nonpacemakers without requiring tonic excitation.
Abstract: Pairs of neurons which inhibit each other can produce regular alternating bursts of impulses if they also exhibit postinhibitory rebound (PIR). Computer studies show that stable patterns occur spontaneously in systems of pacemaker neurons with PIR, and can be triggered in systems of nonpacemakers without requiring tonic excitation. The repetition rates of these patterns are determined largely by the PIR parameters. The patterns resist perturbation by phasic synaptic inputs, but can be modulated or turned off by tonic inputs. One pair of PIR neurons can be entrained by another pair with a different repetition rate to produce more complex firing patterns.
01 Jan 1974
TL;DR: In this paper, an improved magnetospheric electric field model is used to compute the initial locations of particles injected by several substorms and trajectories are traced from the time of their encounter with the ATS-5 satellite backwards to the onset time given by ground-based magnetometers.
Abstract: An improved magnetospheric electric field model is used to compute the initial locations of particles injected by several substorms. Trajectories are traced from the time of their encounter with the ATS-5 satellite backwards to the onset time given by ground-based magnetometers. A spiral shaped inner boundary of injection is found which is quite similar to that found by a statistical analysis. This injection boundary is shown to move in an energy dependent fashion which can explain the soft energy spectra observed at the inner edge of the electrons plasma sheet.
TL;DR: In this paper, the spatial pattern of cooling near a spreading ridge crest was investigated with a suite of 71 precisely-navigated heat-flow stations on the Galapagos spreading centre, East Pacific, near 86"W longitude.
Abstract: Summary The spatial pattern of cooling near a spreading ridge crest was investigated with a suite of 71 precisely-navigated heat-flow stations on the Galapagos spreading centre, East Pacific, near 86"W longitude. Stations are on crust less than 1.0 My old on which bathymetry and sediment distribution are well known. Values vary from near zero to greater than 30 HFU (10-6 cal cm-2 s-1). The average over the entire region is significantly less than that predicted by theoretical conduction models of a cooling lithosphere. We observe a regular variation of the heat-flow pattern with a wavelength of 6 & 1 km approximately normal to the ridge crest. Heat-flow maxima are characteristically located near faults and local topographic highs. The locations of fields of small sediment mounds, apparently hydrothermal vents, are also restricted to these faulted, elevated areas of high heat flow. Near-axis, bottom water temperature anomalies of several hundredths "C were detected. The low average, the low minima in the heat-flow pattern, and the water temperature anomalies suggest that hydrothermal circulation accounts for approximately 80 per cent of the geothermal heat released near the ridge crest. We conclude that the hydrothermal circulation pattern is controlled by one or more of the following physical properties of the system : highly developed cellular convection, discrete zones of high permeability, variation in the strength of heat sources near the base of the crust, or bottom topography. Our results imply that heat-flow studies near active oceanic ridges will be of most value if they are sufficiently detailed and well navigated to define the systematic small-scale variations that appear to be caused by hydrothermal circulation.
TL;DR: Coronary arterial occlusion resulted in extension of myocardial infarction in 44 percent of the animals, and Hemoglobin content in biopsy specimens from the center of the infarct was 10 times greater in the animals with extension of infarctions than in those with myocardia salvage.
Abstract: The effect of coronary reperfusion on evolving myocardial infarction was examined in 16 conscious dogs. Coronary arterial occlusion was produced by inflating an exteriorized balloon cuff, and reperfusion was initiated 5 hours later by deflating the cuff. Infarct size calculated from 24 hour serial serum creatine phosphokinase (CPK) values was compared to infarct size predicted from log normal curves best fit to initial 5 hour serial CPK changes. With sustained occlusion, predicted and observed infarct size correlated closely ( r = 0.94, no. = 11). Reperfusion produced two disparate effects. In nine dogs, observed infarct size was less than predicted, reflecting 42 ± 6 percent (standard error) salvage of myocardium. In seven dogs, observed infarct size exceeded predicted size by more than 100 percent. Thus, reperfusion resulted in extension of myocardial infarction in 44 percent of the animals. Extension of infarction was associated with myocardial hemorrhage. Hemoglobin content in biopsy specimens from the center of the infarct was 10 times greater in the animals with extension of infarction than in those with myocardial salvage. Thus, reperfusion is not without hazard during evolving infarction in the conscious dog; although it frequently diminishes ischemic injury, it may precipitate myocardial hemorrhage and extension of infarction.
TL;DR: In this article, the authors present a theoretical overview of cognitive algebra and the interrelations between attribution theory and theory of information integration, and explore a few relevant results of these models.
Abstract: Publisher Summary This chapter presents the theoretical overview of cognitive algebra. It considers some of the interrelations between attribution theory and theory of information integration. Both integration theory and attribution theory have been much concerned with person perception, but there has been little interaction between them. One reason has been their orientation toward different aspects of the judgment process. Attribution theory has been concerned primarily with questions of valuation, and integration itself has received little attention. In contrast, the first concern of integration theory is how information is combined or integrated. Three main types of algebraic models have been used in the study of information integration: adding, averaging, and multiplying models. The chapter explores a few relevant results of these models. In certain experiments, a stimulus person is portrayed subject to two or more forces. These forces may be internal or external, and they may be parallel or opposed in direction. The judgments required of the subject typically involve the mediation of a force model imputed by the subject to account for the behavior of the stimulus person.
01 Mar 1974-Journal of Comparative Physiology A-neuroethology Sensory Neural and Behavioral Physiology
TL;DR: The Stomatogastric ganglion of Panulirus interruptus contains about 30 neurons, and controls the movements of the lobster's stomach, and a group of six neurons which drive the stomach's lateral teeth are described.
Abstract: The Stomatogastric ganglion ofPanulirus interruptus contains about 30 neurons, and controls the movements of the lobster's stomach When experimentally isolated, the ganglion continues to generate complex rhythmic patterns of activity in its motor neurons which are similar to those seen in intact animals
TL;DR: In this paper, serum testosterone (T) and androstenedione (Δ) levels were measured before and 6 to 8 weeks after oophorectomy in 5 premenopausal and 16 postmenopausal patients with endometrial cancer.
TL;DR: A model for the recognition of tachistoscopically presented words is developed and it is shown that under certain simplifying assumptions this sophisticated guessing model is isomorphic with the "criterion bias" model as developed in 1967 by Broadbent.
Abstract: A model for the recognition of tachistoscopically presented words is developed. The model is a \"sophisticated guessing\" model which takes explicit account of the geometry of the characters which make up the words or letter strings. Explicit attempts are made to account for word frequency effects, effects due to letter transition probabilities, and effects due to physical similarity of character strings to one another. A word recognition experiment using the set of three-letter words is reported, and the model is used to make quantitative predictions of these results as well as to give a qualitative account for a number of results in the literature. Finally, it is shown that under certain simplifying assumptions this sophisticated guessing model is isomorphic with the \"criterion bias\" model as developed in 1967 by Broadbent. The process whereby words are recognized has long fascinated experimental psy-Several related findings have commanded the most attention. For example, more letters per unit time may be apprehended when a word is presented than when a string of unrelated letters is presented (Huey, 1908). A letter string formed by taking a word and either deleting or replacing one or two letters is often clearly perceived as that word (Pillsbury, 1897). Other things being equal, words which occur frequently in the language are more easily perceived than those which occur less frequently (Goldia-The more the statistics of letter strings approximate those of words, the better the perception of the letter strings (cf. Miller, Bruner, & Postman , 1954). The more predictable a word is within a sentence, the more easily it is Most explanations of these phenomena suggest that they all result from the fact that the subject combines internally provided information about language with externally provided information from the sensory system (cf. Morton, 1969, 1970). By this argument, words are easier to see than nonwords because we can apply our knowledge of the vocabulary of the language. Knowledge of relative frequencies of words in the language allows us to read high-frequency words more readily. Knowledge of syntactic and semantic relations allows us to read words more easily in the context of 99
TL;DR: The hypothesis that neuroendocrine effects of androgens on fetal, neonatal, prepubertal and adult rats could be mediated by estrogen metabolites is supported.
Abstract: Incubation of hypothalamic and limbic system homogenates from 21-day rat fetuses and 1, 5, 10-day-old or adult rats with E4- androstene-3-17-dione 7-3H resulted in the formation of 3H-estrone by all tissues with the exception of the limbic system from the female fetuses. In each paired experiment the activity in male tissues exceeded that of the females. In general, the activities of perinatal tissues either equaled or exceeded those of comparable adult tissues. These results support the hypothesis that neuroendocrine effects of androgens on fetal, neonatal, prepubertal and adult rats could be mediated by estrogen metabolites. (Endocrinology 94: 117, 197.4)
TL;DR: General principles of acetone precipitation are presented as a guide in clinical interpretation of the L/S ratio and evidence is presented that there is continuity between the fetal lungs and amniotic fluid.
TL;DR: The 85-residue structure of Chromatium high potential iron protein has been determined by x-ray diffraction methods at 2.0 A resolution, and is currently undergoing crystallographic refinement, which is an unusually well determined protein structure.
TL;DR: It is demonstrated that somatostatin in humans not only exerts an inhibitory effect on growth hormone secretion but also on TSH release in response to TRF, suggesting an interrelationship between the regulation of growth hormone and TSH secretion.
Abstract: Concomitant administration of somatostatin and thyrotropin-releasing factor (TRF) significantly inhibited the release of TSH induced by TRF without affecting the simultaneous secretion of prolactin (PRL) in normal adult subjects. However, within our experimental design (iv bolus of 250 μg TRF plus 500 μg somatostatin followed by constant infusion of 500 μg somatostatin over 45 min) the inhibition of TSH release by somatostatin was incomplete. The present study demonstrates that somatostatin in humans not only exerts an inhibitory effect on growth hormone secretion but also on TSH release in response to TRF. These findings suggest an interrelationship between the regulation of growth hormone and TSH secretion.