Showing papers by "University of California, Irvine published in 1969"
TL;DR: The brains of ten rabbits sacrificed 6–21 days after unilateral ocular enucleation were prepared by Nauta and Nissl methods and used to study the projection and terminal destribution of degenerating optic axons.
Abstract: The brains of ten rabbits (4 pigmented and 6 albino) sacrificed 6–21 days after unilateral ocular enucleation were prepared by Nauta and Nissl methods and used to study the projection and terminal destribution of degenerating optic axons. The retina is bilaterally represented in the alpha sectors of both ventral and dorsal lateral geniculate nuclei (LGv and LGd), in n. tractus opticus (NTO), in the dorsolateral portions of nn. praetectalis anterior (NPA) and posterior (NPP), and in the superior colliculus (SC). The retina is unilaterally represented in the contralateral terminal accessory optic nuclei.
The mode of termination of crossed and uncrossed retinal projections endows the LGd with a concealed laminar organization. Four laminae are recognized and numbered consecutively from lateral to medial. Lamina one is extensive and formed entirely of crossed retinal input. The remaining three laminae occupy the medial zone of the LGd. Of these, laminae two and four are innervated predommantly by the ipsilateral retina while lamina three is supplied mainly by the contralateral retina. Uncrossed retinal innervations of LGv, NTO, NPA, NPP and SC are scant and overlapped entirely by crossed retinal inputs. Chiasmal decussation of the optic nerve is 90–95% complete with the uncrossed component, and specifically the uncrossed retino-LGd and -SC projections, being larger in pigmented as compared with albino rabbits.
260 citations
TL;DR: It was concluded that androgen stimulation of the mouse early in life causes the differentiation of a neural system for aggression which is more sensitive to androgen in adulthood than the system developing in the absence of neonatal androgenic stimulation.
225 citations
TL;DR: It is concluded that mutant ts(-) 136 is defective either in the synthesis of all types of cy toplasmic RNA, or in the transport of newly synthesized RNA from the nucleus to the cytoplasm, and that the mRNA of a eucaryotic organism (yeast) is metabolically unstable, having a half-life of approximately 23 min at 36 C.
Abstract: A single, recessive mutation in a nuclear gene confers a temperature-sensitive growth response in a mutant of Saccharomyces cerevisiae, ts− 136. The mutant grows normally at 23 C, but exhibits a rapid and preferential inhibition of ribonucleic acid (RNA) accumulation after a shift to 36 C, demonstrating a defect in stable RNA production. Cultures of the mutant which were shifted from 23 to 36 C display the following phenomena which indicate that messenger RNA (mRNA), as well as stable RNA production, is defective. The entrance of pulse-labeled RNA into cytoplasmic polyribosomes is even more strongly inhibited than is net RNA accumulation. The rate of protein synthesis, at first unaffected, decreases slowly; this decrease is paralleled by the decay of polyribosomes to monoribosomes with a half-time of 23 min. The polyribosomes which remain after a 30-min preincubation of the mutant at 36 C are active in polypeptide synthesis in vivo, whereas the monoribosomes which accumulate are not. Furthermore, ribosomes isolated from a culture of the mutant preincubated for 1 hr at 36 C are inactive in polypeptide synthesis in vitro, but can be restored to full activity by the addition of polyuridylic acid as mRNA. We conclude that mutant ts− 136 is defective either in the synthesis of all types of cytoplasmic RNA, or in the transport of newly synthesized RNA from the nucleus to the cytoplasm, and that the mRNA of a eucaryotic organism (yeast) is metabolically unstable, having a half-life of approximately 23 min at 36 C.
173 citations
TL;DR: The findings are interpreted as providing further support for the view that amphetamine facilitates learning by affecting time-dependent memory storage processes.
Abstract: Two experiments investigated the effects ofd-amphetamine on food-rewarded visual discrimination learning in mice. The findings of Experiment 1 indicate that degree of facilitation learning obtained with posttrial i.p. injections varied with dose: Facilitation was obtained with doses ranging from 0.25 to 2.0 mg/kg, but not with a higher dose (2.5 mg/kg). The findings of Experiment 2 indicate that degree of facilitation varies with time of administration. With two doses (0.5 and 2.0 mg/kg) facilitation was obtained with injections given up to 30 minutes before training or immediately after daily training. No significant effect was obtained with injection given 15 minutes after training. The findings are interpreted as providing further support for the view that amphetamine facilitates learning by affecting time-dependent memory storage processes.
147 citations
TL;DR: The existence and uniqueness theorem for the nonlinear complementarity problem was proved in this article, where it was shown that the problem has a unique solution if the given mapping is continuous and strongly monotone on the nonnegative orthant.
Abstract: The main result in this paper is an existence and uniqueness theorem for the following nonlinear complementarity problem: Given a mapping from then-dimensional Euclidean spaceE
n
into itself, find a nonnegative vector inE
n
whose image, under the given mapping, is also nonnegative, the two vectors being orthogonal to each other It is shown that the above problem has a unique solution if the given mapping is continuous and strongly monotone on the nonnegative orthantE
+
ofE
n
It is also shown that a sufficient condition for a differentiable mapping to be strongly monotone on an open set is that all the eigenvalues of the symmetric part of its Jacobian be bounded below by a positive constant on the given set
140 citations
TL;DR: In this paper, the authors define stochastic models for population growth from the classical discrete deterministic model by assuming that the deterministic models are subject to additive random errors; the elements of the transition matrix represent probabilities, rather than rates; and the transition matrices are random variables.
Abstract: In an effort to provide probabilistic measures of the accuracy of population projections, stochastic models for population growth are defined from the classical discrete deterministic model by assuming respectively that (1) the deterministic model is subject to additive random errors; (2) the elements of the transition matrix represent probabilities, rather than rates; and (3) the transition matrices are random variables. The mean of each process is shown to reproduce the deterministic process, while the variance can be expressed as the weighted sum of one-step conditional variances. For the second model, these “innovation variances” will be small for large populations, while for the first and third models their size will depend on the observed variability of, respectively, prediction errors and vital rates. Since it is known empirically that both the latter are quite variable, these models could be expected to yield relatively high prediction variances, and this expectation is confirmed by a num...
112 citations
TL;DR: It is reported that in the case of tuberculin hypersensitivity in mice, guinea-pigs and man, non-specific toxic materials are released when the cells are cultured in the presence of specific antigen.
Abstract: ALLOGRAFT immunity and delayed hypersensitivity reactions are caused chiefly by the action of host immune lymphoid cells1. Although these reactions have been much studied in vivo and in vitro, the mechanism of cell destruction is essentially unknown. There have been reports from this laboratory that a cell-free toxic factor released by immune and phytohaemagglutinin (PHA)-stimulated non-immune mouse lymphocytes is essential in the in vitro destruction of target L cells2. This factor, termed lymphotoxin (LT), caused in vitro cytolysis of both continuous and primary cells obtained from many animal species3. Later work showed that lymphocytes from various animal species, including man, could be stimulated in vitro to release LT, in the absence of target cells, by treatments which induce lymphocyte transformation, that is the mixed lymphocyte reaction, PHA and xenogeneic antibody4. It was therefore of interest to investigate whether lymphoid cells obtained from animals with delayed hypersensitivity to soluble antigens could be induced in vitro to release LT-like materials. We wish to report here that in the case of tuberculin hypersensitivity in mice, guinea-pigs and man, non-specific toxic materials are released when the cells are cultured in the presence of specific antigen.
108 citations
TL;DR: In this paper, the maximum depth at wave crest, minimum depths at wave trough, wave period and wave velocity of spontaneously developed roll-wave trains were measured in a laboratory channel.
Abstract: The maximum depth at wave crest, minimum depth at wave trough, wave period and wave velocity of spontaneously developed roll-wave trains were measured in a laboratory channel. Channel slope (\IS\N\DO\N) was varied from 0.05 to 12, normal depth (\Ih\N\Dn\N) was varied by a factor of two, and the Froude number of the undistrubed flow (F) ranged from 3.5 to 5.6. For each of the four properties, a single development curve resulted for all \Ih\N\Dn\N, with \IS\N\DO\N and F fixed. The spatial rate of growth of the average maximum depth increased as F was increased by increasing \IS\N\DO\N. The growth rate decreased as \IS\N\DO\N was increased and F was held fixed. Substantial growth occurs when one wave overtakes and combines with another wave. Growth also occurs without wave overtaking. Spontaneously developed roll waves are shown to be related to periodic permanent roll waves. Methods of applying the laboratory results to other channels with inlet conditions similar to that of the laboratory channel are presented.
108 citations
TL;DR: Vibratile cells apparently release an acid mucopolysaccharide which immobilizes foreign material including microorganisms entering the coelom through wounds in the gut; probably they also release the mucin in bacteria-infected hanging drops.
103 citations
TL;DR: The main existence and uniqueness theorem of Part 1 is applied to three specific problems, namely, (a) the symmetric, dual, nonlinear programs of Dantzig, Eisenberg, and Cottle, (b) the saddle point problem of a differentiable scalar function over an unbounded product set, and (c) the equilibrium-point problem of ann-person game as mentioned in this paper.
Abstract: The main existence and uniqueness theorem of Part 1 is applied to three specific problems, namely, (a) the symmetric, dual, nonlinear programs of Dantzig, Eisenberg, and Cottle, (b) the saddle point problem of a differentiable scalar function over an unbounded product set, and (c) the equilibrium point problem of ann-person game.
98 citations
TL;DR: A rudimentary model of the public school system as an input-output process relating outputs to inputs is presented and some implementation of the model has been made possible by means of data gathered in the U.S. Office of Education's Equality-of-Educational-Opportunity Survey.
Abstract: This paper presents a rudimentary model of the public school system as an input-output process. The inputs are students' own abilities and attitudes, parental support, peer support, quality of the school system, community support, and society's posture with respect to education. Outputs are various categories of academic achievement as well as social competence, responsibility, self confidence, creativeness, ethics, and ambition. All these factors must be measured by index numbers or simple indicators. The model is a set of regression equations relating outputs to inputs. Some implementation of the model has been made possible by means of data gathered in the U.S. Office of Education's Equality-of-Educational-Opportunity Survey.
TL;DR: Apparently only the phagocytic leukocyte is involved in cellular clotting, and extracellular gelling of the coelomic fluid was not observed, and a special lysing cell type which initiates clotting was not found despite suggestions in the literature that cell aggregation in echinoids is dependent upon such a mechanism.
TL;DR: In this article, it was suggested that the properties of mucoid substances in invertebrate spherule-bearing cells may be as variable as is true of vertebrate mast cells.
Abstract: Coelomocytes of Strongylocentrotus purpuratus and Strongylocentrotus franciscanus include phagocytic leukocytes, flagellated “vibratile cells”, and two types of spherule-bearing cells; one of which contains echinochrome, a red naphthaquinone pigment. Vibratile cells are PAS positive and contain a strongly acidic mucopolysaccharide. Substances with similar staining and chemical properties appear in the coelomic fluid under certain stress conditions. It is supposed that these substances enter the fluid by diffusion from the vibratile cells. Tests indicate that both spherule-cell types, like the spherule cells of holothurians (sea cucumbers), may undergo a cycle during which they pass from a basophilic to an acidophilic state. Chemical properties of the spherule cells approximate those of vertebrate mast cells. The variability of staining and chemical reactions of spherule cells explains why published accounts of their properties have differed so widely. It is suggested that the properties of mucoid substances in invertebrate spherule-bearing cells may be as variable as is true of vertebrate mast cells.
TL;DR: In this paper, the flexor withdrawal reflex (tibialis anterior muscle) was studied in acute spinal cat as a function of stimulus intensity and frequency for frequencies ranging above 1 2 sec.
TL;DR: In this paper, the authors present a model to measure the effect of different changes in system characteristics, e.g., a change in bus fare, or parking cost, or change in vehicle driver's behavior.
TL;DR: In this paper, the spin wave eigenfrequencies and eigenfunctions for a model ferromagnetic film, in the presence of both exchange and magnetic dipole interactions, were examined.
Abstract: We have examined the spin-wave eigenfrequencies and eigenfunctions for a model ferromagnetic film, in the presence of both exchange and magnetic dipole interactions A detailed computer study of spin waves in a thirty-layer film is presented for the case where the exchange and dipole interactions are of comparable strength We discuss in detail both surface and "bulk" modes for this case Also, the symmetry properties of the eigenvectors are discussed, along with a method for converting certain two-dimensional dipole sums to a rapidly converging form
TL;DR: All patients with apparent aortic stenosis should be studied with isoproterenol at catheterization and patients with both lesions should be treated with propranolol; and if this treatment does not result in improvement, then the subvalvular narrowing should be carefully evaluated and relieved at the time of valvular operation.
Abstract: Four cases of coexistent aortic valvular stenosis and functional subaortic stenosis are presented. The first patient died of low cardiac output after replacement of the aortic valve, and concomitant subvalvular hypertrophy was discovered at autopsy. Patients presenting clinically with aortic valvular stenosis were subsequently challenged with isoproterenol at cardiac catheterization. Three had hemodynamic evidence of subaortic functional hypertrophy and aortic valvular stenosis. Postextrasystolic beats were also indicative of subaortic stenosis in these cases. All had angiographic evidence of subaortic functional hypertrophy and, in 1, confirmation was obtained at postmortem examination. These studies indicate: (1) patients with both conditions appear clinically to have valvular stenosis; (2) all patients with apparent aortic stenosis should be studied with isoproterenol at catheterization; (3) patients with both lesions should be treated with propranolol; and (4) if this treatment does not result in improvement, then the subvalvular narrowing should be carefully evaluated and relieved at the time of valvular operation.
TL;DR: In this article, a mathematical characterization of the conditions under which groups become relevant for the study of kinship is given and is related to the theory of structural balance, and it is argued that the concept of group extension and its specialization to direct and semidirect products determine the evolutionary sequences and the coding of these kinship systems.
TL;DR: The synthetic steroid cyproterone acetate exerts strong antiandrogenic properties with respect to the seminal vesicles, but not withrespect to androgen dependent mating behavior in male rats.
Abstract: The synthetic steroid cyproterone acetate (6-chloro-17-hydroxy-lα,2α-methylenepregna- 4,6-diene-3,20-dione acetate) exerts strong antiandrogenic properties with respect to the seminal vesicles, but not with respect to androgen dependent mating behavior in male rats. Gonadectomized, sexually experienced male rats were treated with 1) testosterone propionate (TP); 2) TP plus cyproterone acetate, or 3) oil for 3 weeks, and given 3 mating tests at weeklyintervals. The seminal vesicles of all males were removed after 2 weeks of treatment. The intensity of mating behavior declined progressively in the oil treated castrates but not the androgen or androgen plus anti-androgen treated males. The seminal vesicles of the oil treated and androgen plus anti-androgen treated rats regressed in comparison with the seminal vesicles of males treated only with testosterone. (Endocrinology 84:155, 1969)
TL;DR: It was shown that this free fatty acid is produced by the breakdown of the cellular phospholipid, not by the release of cell wall fatty acid or by the de novo synthesis of fatty acid.
TL;DR: Non-feeding larvae showed rates of glycine accumulation which were significantly higher than those predicted from data on feeding stages, and the relation between the log of cpm and log of weight is linear over 4 orders of magnitude variation in size.
Abstract: Neanthes arenaceodentata (Moore) accumulates glycine −C14 from a dilute solution of seawater. After a 30 min exposure, 5 to 102 times as much radioactivity per unit volume is found in the animals (depending on the size and feeding stage of the worm) as is present in the medium. The relation between the log of cpm and log of weight is linear over 4 orders of magnitude variation in size. The rates of uptake were more variable in non-feeding stages of the life cycle. Non-feeding larvae showed rates of glycine accumulation which were significantly higher than those predicted from data on feeding stages.
TL;DR: In this paper, the influence of an adorbed layer of atoms on the vibrational properties of a simple model crystal is considered and the change in specific heat and entropy are computer for arbitrary temperatures, assuming the defect layer differs only in mass from the atoms in the bulk crystal.
TL;DR: It is concluded that there is no evidence for accumulation or assimilation of small organic compounds by the small crustaceans examined.
Abstract: Soft-bodied marine invertebrates from most invertebrate phyla are capable of taking up amino acids from seawater. Marine crustaceans were originally reported not to accumulate amino acids. Artemia salina, Limnoria tripunctata, Tigriopus californicus, and Corophium acherusicum were examined for their ability to accumulate C14-labelled glycine from dilute solution in seawater. In initial experiments with Artemia and Limnoria the organisms were found to become very radioactive. When animals were preincubated in streptomycin or in a mixture of antibiotics, uptake of the C14-glycine was drastically reduced. Microorganisms associated with the arthropods and in the culture media were found capable of accumulating C14-labelled glycine. Efforts to demonstrate removal of amino acids from seawater by colorimeteric determination of material remaining in the medium were unsuccessful. The microorganisms responsible for the uptake are apparently associated with the exoskeleton of the organisms and not the gut. There is probably no substantial contribution to the nutrition of these crustaceans by the epiflora. Preincubation in the antibiotic mixture depressed the uptake of C14-glucose and C14-acetate by about an order of magnitude. It is concluded that there is no evidence for accumulation or assimilation of small organic compounds by the small crustaceans examined.
TL;DR: It was concluded that early testosterone stimulation does not enhance the rat's potential to display masculine sexual behavior or its reactivity to testosterone in adulthood.
TL;DR: It is concluded that charged aminoacyl-tRNA is essential for RNA synthesis and for the multivalent repression of the isoleucine biosynthetic enzymes.
Abstract: Temperature-sensitive mutations in the isoleucyl-transfer ribonucleic acid (tRNA) synthetase of yeast, ilS−1-1 and ilS−1-2, were used to examine the role of aminoacyl-tRNA synthetase enzymes in the regulation of ribonucleic acid (RNA) synthesis and enzyme synthesis in a eucaryotic organism. At the permissive temperature, 70 to 100% of the intracellular isoleucyl-tRNA was charged in mutants carrying these mutations; at growth-limiting temperatures, less than 10% was charged with isoleucine. Other aminoacyl-tRNA molecules remained essentially fully charged under both conditions. Net protein and RNA syntheses were rapidly inhibited when the mutant was shifted from the permissive to the restrictive temperature. Most of the ribosomes remained in polyribosome structures at the restrictive temperature even though protein synthesis was strongly inhibited. Two of the enzymes of isoleucine biosynthesis, threonine deaminase and acetohydroxyacid synthetase, were derepressed about twofold during slow growth of the mutants at a growth-limiting temperature. This is about the same degree of derepression that is achieved by growth of an auxotroph on limiting isoleucine. We conclude that charged aminoacyl-tRNA is essential for RNA synthesis and for the multivalent repression of the isoleucine biosynthetic enzymes. Aminoacyl tRNA synthetase enzymes appear to play important regulatory roles in the cell physiology of eucaryotic organisms.
TL;DR: The above results suggest the presence of a proline-glutamate interconversion oxidation pathway similar to the proline oxidase metabolic system found in a variety of organisms.
TL;DR: Assessment of the relative contributions of arousal and attentional factors affecting the amplitude of the visual evoked cortical potential and reaction time latency revealed that the evoked potentials recorded during the avoidable shock condition (3) were significantly larger than during the other three conditions.
Abstract: In the present study an attempt has been made to assess the relative contributions of arousal and attentional factors affecting the amplitude of the visual evoked cortical potential and reaction time latency. Subjects were studied under the following four conditions: (1) passively watching a small, dim, intermittent flash; (2) reacting to each flash by releasing a lever, thereby giving a reaction time; (3) reacting to each flash within a specified period of time in order to avoid an uncomfortable shock to the fingers; (4) reacting to each flash while receiving occasional unavoidable shock. Statistical analyses revealed that the evoked potentials recorded during the avoidable shock condition (3) were significantly larger than during the other three conditions. Reaction times were routinely shorter during condition 3, followed by the no-shock (2) and then unavoidable shock (4) conditions.
TL;DR: The findings are interpreted as suggesting that the effectiveness of ECS in producing RA varies with the amount of current reaching the brain.
Abstract: Electroencephalographic changes occurring in rat brain following frontal cortex stimulation in non-lesioned rats and in rats with bilateral lesions in the region of amygdala were investigated in Experiment I. Seizure duration and EEG spike frequency varied systematically with current level. The amnesic effects of conventional ECS and frontal cortex stimulation were studied in Experiment II. Both treatments were highly effective in producing retrograde amnesia for an inhibitory avoidance response. The findings are interpreted as suggesting that the effectiveness of ECS in producing RA varies with the amount of current reaching the brain.