Showing papers by "University of Colorado Boulder published in 1971"
TL;DR: The adult respiratory distress syndrome (ARDS) is an important and common medical emergency and is likely to occur in all hospitals dealing in respiratory care as mentioned in this paper, which occurs from a variety of diffuse pulmonary injuries which are either direct or indirect attacks on the lung parenchyma.
705 citations
TL;DR: In this article, the identity and connection with the Hilbert spaces of entire functions of growth (1, 1) are studied. And the application to the evaluation of matrix elements of finite group elements and the contraction to the usual coherent states are discussed.
Abstract: Generalized “Coherent” States are the eigenstates of the lowering and raising operators of non-compact groups. In particular the discrete series of representations ofSO (2, 1) are studied in detail: the resolution of the identity and the connection with the Hilbert spaces of entire functions of growth (1, 1). Also discussed are the application to the evaluation of matrix elements of finite group elements and the contraction to the usual coherent states.
695 citations
TL;DR: Subjects learned and recognized patterns which were marginally visible, requiring them to fixate directly each feature to which they wished to attend, and fixed "scanpaths," specific to subject and pattern appeared in their saccadic eye movements.
Abstract: Subjects learned and recognized patterns which were marginally visible, requiring them to fixate directly each feature to which they wished to attend Fixed "scanpaths," specific to subject and pattern, appeared in their saccadic eye movements, both intermittently during learning and in initial eye movements during recognition A proposed theory of pattern perception explains these results
636 citations
TL;DR: The specificity of the assay has been demonstrated in experiments in which various factors that influence either tyrosine hydroxylase or aromatic l-amino acid decarboxylase activity were omitted, and the sensitivity of the method has been shown to be greater in the laboratory than tyrosin hydroxyase assays currently used.
454 citations
TL;DR: In this paper, DNA was isolated from macronuclei and micronucleis of the ciliated protozoan, Stylonychia mytilus under conditions that minimize the possibility of DNA degradation.
Abstract: DNA was isolated from macronuclei and micronuclei of the ciliated protozoan, Stylonychia mytilus under conditions that minimize the possibility of DNA degradation Macronuclear DNA has an S value of 10 to 11 in sucrose gradients Macronuclear DNA has an average molecular weight of 115×106 daltons and a range of molecular weights of 10×106 to 195×106 daltons The average length of macronuclear DNA, measured by electron microscopy, is 080 microns and the range is 02 to 22 microns Almost all micronuclear DNA pieces are too long to be measured by electron microscopy The shortest piece of micronuclear DNA found was 150 microns in length
380 citations
TL;DR: It is reported that N6O2 dibutyryl adenosine 3′:5′-cyclic monophosphate (dibutyRYl cyclic AMP) induces axon formation in mouse neuroblastoma cells in vitro.
Abstract: The mechanism of mammalian neural differentiation is still obscure; but the availability of mouse neuroblastoma cells in vitro provides an opportunity to study some possible inducers of differentiation and this may help to elucidate the events involved at the molecular level. We have reported1 that X-irradiation of mouse neuroblastoma cells in vitro induces the formation of axons. The differentiated cells seem to undergo maturation: the soma and nucleus increase in size and the cytoplasm becomes granular. Here we report that N6O2 dibutyryl adenosine 3′:5′-cyclic monophosphate (dibutyryl cyclic AMP) induces axon formation in mouse neuroblastoma cells in vitro.
368 citations
TL;DR: In this paper, the authors measured the nitric oxide density profile in the upper atmosphere between 70 and 110 km with scanning ultraviolet spectrometers aboard two Nike-Apache rockets on February 6 and January 31, 1969.
Abstract: The nitric oxide density profile in the upper atmosphere between 70 and 110 km was measured with scanning ultraviolet spectrometers aboard two Nike-Apache rockets on February 6 and January 31, 1969. The observed nitric oxide density profile has a maximum of about 108 cm−3 at 105 km, and a minimum of about 107 cm−3 at 85 km. Photochemical equilibrium is prevalent at about 85 km while mixing dominates below that altitude. A model in which nitric oxide is formed from N(2D) atoms can explain the observed features of the height profile. The contribution of nitric oxide ionization by solar Lyman-α to the total ion production is dominant in the middle D region (below 90 km) for the solar activity level at the time of the experiments. Dissociative recombination of nitric oxide ions is the main loss process in the region above 85 km. Below that height, a faster mechanism is required.
297 citations
TL;DR: For instance, this paper found that training conditions with greater item exposure (study and recognition trials) resulted in more effective recognition, while the conditions which encouraged retrieval (recall and recognition test trials) facilitated recall.
274 citations
TL;DR: The combination of reduced energy reserves in newborn infants with intra-uterine growth retardation, plus the increased utilization of carbohydrates during birth hypoxia, resulted in a high incidence of neonatal hypoglycemia in the first few hours after birth.
Abstract: The incidence of hypoglycemia was determined in newborn infants in a general obstetric service. A random sample of patients was studied from nine birth weight-gestational age groups before the first feeding at 3 to 6 hours after birth. The highest incidence of hypoglycemia, 67% (serum glucose level Except for IDM9s, evidence of intra-uterine growth retardation from the physical examination and confirmed by the weight/length ratio was demonstrated in infants who became hypoglycemic. An added stress in the form of birth hypoxia was present in the majority of the infants who became hypoglycemic. The combination of reduced energy reserves in newborn infants with intra-uterine growth retardation, plus the increased utilization of carbohydrates during birth hypoxia, resulted in a high incidence of neonatal hypoglycemia in the first few hours after birth.
258 citations
TL;DR: Upper Martian atmosphere UV emission spectrum observation noting carbon dioxide photoionization, ion fluorescent scattering and photon/electron dissociative excitation as discussed by the authors, showing that carbon dioxide photos are photoionized.
Abstract: Upper Martian atmosphere UV emission spectrum observation noting carbon dioxide photoionization, ion fluorescent scattering and photon/electron dissociative excitation
252 citations
TL;DR: It is suggested that tumour cells could arise in the brain itself or be carried there from other sites, and the possibility that neoplastic cells would grow more readily in this relatively immunologically privileged environment than in other tissues.
TL;DR: In this article, the authors analyzed four Lyman alpha airglow measurements of the limb and disk of Mars, made by ultraviolet spectrometers on Mariner 6 and 7 in 1969 and Mariner 9 in 1971, to determine the amount and distribution of atomic hydrogen above 80 km.
Abstract: Four Lyman alpha airglow measurements of the limb and disk of Mars, made by ultraviolet spectrometers on Mariner 6 and 7 in 1969 and Mariner 9 in 1971, are analyzed to determine the amount and distribution of atomic hydrogen above 80 km. The variation of atomic hydrogen with altitude is calculated by using time-independent chemical diffusion models from 80 to 250 km, and an exospheric model is used above 250 km. By employing radiative transfer theory that includes effects of pure absorption and accounts for temperature variations in the atmosphere, a spherical model of the airglow Lyman alpha emission is used to produce theoretical intensities for comparison with the data. It is found that (1) the exospheric temperature and distribution in 1971 are consistent with those determined in 1969, (2) the vertical optical depth above 80 km was 2.2 in 1969 and 5 in 1971, and (3) the derived atomic hydrogen distribution from 80 to 250 km requires a source of atomic hydrogen above 80 km. Comparison of observed profiles with chemical diffusion models implies a large downward flow of atomic hydrogen at 80 km coupled with a large upward flow of molecular hydrogen.-
TL;DR: In this article, the authors study subsets of coherent states based on square lattices in the complex plane, where Zm,n =γ(m+in) for m,n=0, ±1, ±2, γ > π, and prove the completeness of the case γ = π by invoking square integrability along with analyticity.
TL;DR: Experiments relating to measurements of total and momentum transfer cross sections for the scattering of low-energy electrons by atoms and diatomic molecules are critically reviewed in this article, where principal emphasis is placed upon the Ramsauer method, dc swarms, and crossed-beams experiments, although other techniques including differential measurements are also discussed.
Abstract: Experiments relating to measurements of total and momentum-transfer cross sections for the scattering of low-energy electrons by atoms and diatomic molecules are critically reviewed. Principal emphasis is placed upon the Ramsauer method, dc swarms, and crossed-beams experiments, which account for the bulk of the reliable data in the literature although other techniques including differential measurements are also discussed. The theories of the various methods and possible sources of error are discussed. The case of low-energy electron scattering by helium is exhaustively reviewed since this system has been most intensively studied experimentally and is particularly amenable as well to theoretical calculations. The best available cross section values, along with comments on individual experiments, are presented in several tables.
TL;DR: The results indicate that cells continue to synthesize DNA during the thymidine block at about one-third the normal rate and do not accumulate at the G 1-S border.
TL;DR: A slight modification of the Lineweaver—Burk equation, in which the form is retained but the instantaneous velocity is replaced by the negative change in substrate concentration divided by the time, allows this linear reciprocal form to be used with little error even when as much as 50% of the substrate is consumed.
TL;DR: Differential staining of human chromosomes can be obtained when the pH of Giemsa stain is changed to 9.0 from the usual 6.8, and identification of homologs is also easier than in cells stained by the latter.
Abstract: Differential staining of human chromosomes can be obtained when the pH of Giemsa stain is changed to 9.0 from the usual 6.8. Such staining permits identification of all homolog pairs and distinct regions within chromosome arms. In most instances, the pattern is quite similar to that obtained with quinacrine mustard fluorescence staining. Certain regions, such as the paracentric constrictions in chromosomes Al and C9, and the distal end of the long arm of the Y chromosome stain differently with the Giemsa 9 technique. The technique is considerably simpler than the quinacrine mustard fluorescence technique and identification of homologs is also easier than in cells stained by the latter.
TL;DR: The recycling of solid wastes is a major ecological goal as mentioned in this paper. But although recycling is technologically feasible, reversing the flow of materials in the channels of distribution, marketing trash through a...
Abstract: The recycling of solid wastes is a major ecological goal. Although recycling is technologically feasible, reversing the flow of materials in the channels of distribution — marketing trash through a...
TL;DR: Gross details of the reproductive cycle and the cytology of oogenesis were studied in 155 egg clutches produced by 69 captive individuals of the triploid parthenogenetic lizard Cnemidophorus uniparens.
Abstract: Gross details of the reproductive cycle and the cytology of oogenesis were studied in 155 egg clutches produced by 69 captive individuals of the triploid parthenogenetic lizard Cnemidophorus uniparens. The mean clutch cycle lasted 23 days. The mean number of ova per clutch was 3.3, and the mean number of oocytes per right and left ovaries was 1.65 and 1.70, respectively. Comparison of the size of the oocytes at ovulation (9–10 mm) with the estimated mean duration of vitellogenesis (8.8 days) gave an average of approximately 1 mm yolk deposition per day. The mean time for the retention of eggs in the oviducts was 9.3 days. The germinal disc of the oocyte consists of a series of layers formed by the arrangement of various cytoplasmic and yolk particles in the polar region. In a mature oocyte the germinal vesicle is located immediately below the vitelline membrane and lies at the center of the germinal disc. The germinal vesicle is characterized by a dense disc-like cluster of diplotene chromosomes. Diplonema extends until near ovulation when the oocytes have attained a size of about 9 mm. Diakinesis and metaphase I occur rapidly and immediately prior to ovulation. Counts of approximately as many bivalents as there are somatic chromosomes were obtained from oocytes at diakinesis and metaphase I.
The second division occurs almost immediately before or at the precise moment of ovulation. The chromosomes of the first polar body consist of dyads, of which there are as many as the triploid number of 69. A metaphase II plate obtained in polar view also revealed dyad chromosomes, of which there were approximately as many as the triploid somatic number. The second telophase is normal as evidenced by formation of the second polar body. Chromosomes from the opposing telophase plates show a monad structure. The presence of as many bivalents in the first division as the triploid somatic number of 69 indicates that the 3N condition of C. uniparens was doubled prior to meiosis. This is further supported by the occurrence of two maturation divisions each giving rise to a polar body, by the dyad structure of the chromosomes in the first polar body and the second metaphase, and by the presence of monochromosomes at telophase II. Thus, parthenogenesis in these lizards is of the meiotic type. The somatic number of chromosomes is doubled early in oogenesis presumably by a premeiotic endoduplication, and the 3N level is restored by two subsequent maturation divisions.
TL;DR: The evolution and origin of parthenogens probably is through hybridization fol?
Abstract: synopsis. The discovery of parthenogenesis in reptiles came about through the casual observation of the lack of males in several species of lizards. Nineteen all female species and subspecies from five genera and three families of lizards have been nanied or recognized. Actual proof of parthenogenesis, however, has been demonstrated for only seven of these. Studies in variation of parthenogens versus the variation of sym? patric bisexual species have been made on six species. In general the parthenogens are much less variable than bisexual species. Males have been found in most of the parthenogens studied. At least some of these seem to result from crosses between parthenogens and males of sympatric bisexual species. In a few instances, however, this seems unlikely. The evidence supporting the hybrid origin of these males rests on a few studies which show that these males have one more genome than the female parthenogens they resemble. The evolution and origin of parthenogens probably is through hybridization fol? lowed by further hybridization in some genera leading to triploidy. Evidence for these hypotheses is provided by a number of karyotype studies, skin transplants, and studies of various proteins. One study indicates that the somatic chromosome number is restored during oogenesis by an endoduplication immediately preceeding meiosis. Cnemidophorus uniparens, the species in which this phenomenon was demonstrated, is a triploid. Evolutionary aspects of parthenogenesis are discussed.
TL;DR: Purified tRNATrp stimulates lysozyme synthesis 30-fold above the level seen when comparable amounts of tryptophan tRNA from the non-suppressing strain, CA244, were added; it also translates poly(U-G-A) as polytryptophan more efficiently than the su− tRNA.
TL;DR: It was concluded that adenyl cyclase exists in its membranous environment in a state of inhibition and treatment with detergents or freezing of the tissue could lead to nonspecific changes in membrane structure which cause reduction of the inhibition and increased catalytic activity.
TL;DR: This report encompasses 3 studies pertaining to the validity and reliability of theDenver Developmental Screening Test (DDST); on the basis of the first 2 studies the interpretation of the test scores was revised and a third study was undertaken to cross- validate the revised method of interpretation.
TL;DR: A model for the process of exercising judgment was outlined, and the results of an empirical study of judgmental learning were employed to show the inadequacy of the traditional outcome feedback procedures.
Abstract: Departing from the traditional model for teaching and learning, this article deals with the problem of teaching and learning the effective application of knowledge already acquired. To this end, a model for the process of exercising judgment was outlined, and the results of an empirical study of judgmental learning were employed to show the inadequacy of the traditional outcome feedback procedures. Computer graphics techniques were used to provide new forms of information to the learner; the results are promising for the rapid learning of a task that would otherwise be difficult to learn.
TL;DR: Several diaminopimelic acid (DAP)- and lysine-requiring mutants of Escherichia coli were isolated and studied by genetic, physiological, and biochemical means.
Abstract: Several diaminopimelic acid (DAP)- and lysine-requiring mutants of Escherichia coli were isolated and studied by genetic, physiological, and biochemical means. The genes concerned with DAP-lysine synthesis map at several different sites on the E. coli chromosome and, therefore, do not constitute a single operon. Three separate loci affecting DAP synthesis are located in the 0 to 2.5 min region of the genetic map. The order of the loci in this region is thr-dapB-pyrA-ara-leu-pan-dapC-tonA-dapD. Two additional DAP genes map in the region between min 47 and 48, with the gene order being gua-dapA-dapE-ctr. The lys locus at min 55 determines the synthesis of the enzyme DAP decarboxylase, which catalyzes the conversion of DAP into lysine. The order of the genes in this region is serA-lysA-thyA.
TL;DR: It is suggested that the large amount of DNA in mammals is functionally important, and that a substantial proportion of the genome is expressed in the brain, as well as the equivalent of at least 300,000 different sequences of 1000 nucleotides are expressed in mouse brain tissue.
Abstract: Under normal conditions of DNA renaturation, about 60 percent of mouse DNA fragments renature at a rate consistent with their being present only once per sperm. These nonrepeated sequences (also called single-copy or unique) may be used in RNA-DNA hybridization experiments to provide quantitative estimates of RNA diversity. About 10 percent of the mouse single-copy sequences are transcribed in mouse brain tissue. Estimates of about 3 percent were obtained for mouse liver and kidney RNA's. If only one of the complementary DNA strands is transcribed, this hybridization value implies that the equivalent of at least 300,000 different sequences of 1000 nucleotides are expressed in mouse brain tissue. It is suggested that the large amount of DNA in mammals is functionally important, and that a substantial proportion of the genome is expressed in the brain.
TL;DR: Analysis of a large number of O c mutants of the lac operon has provided evidence indicating that the preponderance of Oc mutations are of the base substitution type and all confer only partial constitutivity for Lac enzyme synthesis.
TL;DR: Synchrony in naturally occurring multinucleate cells is seen as a natural process in embryonic development and cell multiplication in viwo and in witro.
Abstract: I . Introduction . . . . . . . . . . . . . I1 . Synchrony in naturally occurring multinucleate cells . . . . . . . A . Protozoa . . . . . . . . . . . . . . . B . Algae . . . . . . . . . . . . . . . C . Fungi . . . . . . . . . . . . . . . D . Invertebrate somatic tissues . . . . . . . . . . . E . Germ cell formation . . . . . . . . . . . . F . Fertilization and co-ordination of pronuclei G . Early embryonic development . . . . . . . . . . . H . Cell multiplication in viwo and in witro
TL;DR: Colonies formed from WBC of patients with AGL appear to go through a process of morphologic maturation to segmented granulocyte forms, but are not inhibitory in this respect.