Showing papers by "Columbia University published in 1978"
TL;DR: In this article, the color gauge theory of strong interactions without arbitrary adjustment of parameters is analyzed and several possibilities are identified, including one which would give a remarkable new kind of very light, long-lived pseudoscalar boson.
Abstract: The requirement that P and T be approximately conserved in the color gauge theory of strong interactions without arbitrary adjustment of parameters is analyzed. Several possibilities are identified, including one which would give a remarkable new kind of very light, long-lived pseudoscalar boson.
3,878 citations
TL;DR: The review suggests a contingency approach to design which develops a feasible set of structural alternatives from which the organization can choose.
Abstract: Concepts of uncertainty and information processing are used to integrate the diverse organization design/structure literatures. This approach more fully explicates the concept of congruence which lies at the heart of contingency ideas. The review suggests a contingency approach to design which develops a feasible set of structural alternatives from which the organization can choose.
2,280 citations
TL;DR: In this article, the authors examined longitudinal sociometric data on adolescent friendship pairs, friends-to-be, and former friends to assess levels of homophily on four attributes (frequency of current marijuana, use, level of educational aspirations, political orientation, and participation in minor delinquency) at various stages of friendship formation and dissolution.
Abstract: Longitudinal sociometric data on adolescent friendship pairs, friends-to-be, and former friends are examined to assess levels of homophily on four attributes (frequency of current marijuana, use, level of educational aspirations, political orientation, and participation in minor delinquency) at various stages of friendship formation and dissolution. In addition, estimates are developed of the extent to which observed homophily in friendship dyads results from a process of selection (assortative pairing), in which similarity precedes association and the extent to which it results from a process of socialization in which association leads to similarity. The implications of the results for interpreting estimates of peer influence derived from cross-sectional data are discussed.
1,490 citations
TL;DR: In this article, 15 chondrites, including eight carbonaceous chondites, were analyzed for rare earth element abundances by isotope dilution, and the persistence of anomalies in chondritic materials relatively removed from direct condensational processes implies that anomalous components were introduced at a late stage of chondrite formation.
1,346 citations
TL;DR: In this article, the authors construct a simple dynamic model that hopefully captures some relevant and interesting aspects of the way in which the transfer of technology takes place, including the role of direct foreign investment.
Abstract: The objective of this paper is to construct a simple dynamic model that hopefully captures some relevant and interesting aspects of the way in which the transfer of technology takes place, including the role of direct foreign investment. The paper is in three parts. The first puts forward the hypothesis that the rate of technological progress in a relatively ''backward'' region is an increasing function of the gap between its own level of technology and that of the ''advanced'' region which improves at a constant rate, and the degree to which it is open to direct foreign investment, measured by the proportion of foreign capital operating in the backward region to domestic capital in that region. The second section considers the determination of the relative growth rates of foreign and domestic capital. The last section combines these elements to form a simple dynamic model that determines the long-run steady-state ratio of technical efficiencies and of foreign to domestic capital and the stability of the path by which they are approached. The effects of changes in various parameters such as the tax rate on foreign profits are also worked out. 6 notes, 19 references.
1,305 citations
TL;DR: High molecular weight DNA from cells containing only one copy of the HSV gene coding for tk was successfully used to transform L+K-cells to the tk+ phenotype, and the acquired phenotype was demonstrated to be donor-derived by analysis of the electrophoretic mobility of the tK activity.
1,188 citations
TL;DR: Patients in a private periodontal practice were reexamined an average of 22 years after their active treatment and the patterns of tooth loss were observed and tooth retention seemed more closely related to the case type than the surgery performed.
Abstract: 1. Six hundred patients in a private periodontal practice were reexamined an average of 22 years after their active treatment and the patterns of tooth loss were observed. 2. During the post-treatment period, 300 patients had lost no teeth from periodontal disease, 199 had lost one to three teeth, 76 had lost 4 to 9 teeth and 25 had lost 10 to 23 teeth. 3. Of 2,139 teeth that originally had been considered of questionable prognosis, 666 were lost. Of these, 394 were lost by one sixth of the patients and only 272 by the other five-sixths. 4. Of 1,464 teeth which originally had furcation involvements, 460 were lost, 240 of them by one-sixth of the patients who deteriorated most. 5. The mortality of teeth which were treated with periodontal surgery was compared with that of teeth which did not have surgery. Tooth retention seemed more closely related to the case type than the surgery performed. 6. In general, periodontal disease is bilaterally symmetrical and there is a predictable order of likelihood of tooth loss according to position in the arch.
894 citations
TL;DR: In this article, the authors used biostratigraphic data from the COST B-2 well to examine the origin of the subsidence of the continental margin off New York.
824 citations
TL;DR: Social psychological antecedents of entry into three sequential stages of adolescent drug use, hard liquor, marihuana, and other illicit drugs, are examined in a cohort of high school students in which the population at risk for initiation into each stage could be clearly specified.
Abstract: The social psychological antecedents of entry into three sequential stages of adolescent drug use, hard liquor, marihuana, and other illicit drugs, are examined in a cohort of high school students in which the population at risk for initiation into each stage could be clearly specified. The analyses are based on a two-wave panel sample of New York State public secondary students and subsamples of matched adolescent-parent and adolescent-best schoolfriend dyads. Each of four clusters of predictor variables, parental influences, peer influences, adolescent involvement in various behaviors, and adolescent beliefs and values, and single predictors within each cluster assume differential importance for each stage of drug behavior. Prior involvement in a variety of activities, such as minor delinquency and use of cigarettes, beer, and wine are most important for hard liquor use. Adolescents' beliefs and values favorable to the use of marihuana and association with marihuana-using peers are the strongest predictors of initiation into marihuana. Poor relations with parents, feelings of depression, and exposure to drug-using peers are most important for initiation into illicit drugs other than marihuana.
788 citations
TL;DR: It is suggested that a command neuron be defined as a neuron that is both necessary and sufficient for the initiation of a given behavior, even though individual neurons of the group fail to meet the criteria.
Abstract: The notion of the command cell has been highly influential in invertebrate neurobiology, and related notions have been increasingly used in research on the vertebrate nervous system. The term "command neuron" implies that the neuron has some critical function in the generation of a normally occurring behavior. Nevertheless, most authors either explicitly or implicitly use a strictly operational definition, independent of considerations of normal behavioral function. That is, command neurons are often defined as neurons which, when stimulated by the experimenter, evoke some behavioral response. Even when utilizing such an operational definition, investigators frequently differ on what they consider to be the exact characteristics that a neuron must have (or not have) to be considered a command cell. A few authors appear to treat command neurons in relation to normal function, but a precise be- haviorally relevant definition has not been specified. Because of the ambiguity in the definition of command neurons, the term can refer to a wide variety of neurons which may play divergent behavioral roles. In some ways the attempt to label a cell as a command neuron may interfere with the process of discovering the complex causal determinants of behavior. Nevertheless, the notion that indi- vidual cells are responsible for certain behaviors is highly appealing, and an attempt to define the command neuron rigorously could be worthwhile. We suggest that a command neuron be defined as a neuron that is both necessary and sufficient for the initiation of a given behavior. These criteria can by tested by: (1) establishing the response pattern of the putative command neuron during presenta- tion of a given stimulus and execution of a well specified behavior; (2) removing the neuron and showing that the response is no longer elicited by the stimulus (necessary condition); and (3) firing the neuron in its normal pattern and showing that the complete behavioral response occurs (sufficient condition). In some cases, groups of neurons, when treated as a whole, may satisfy the necessity and sufficiency criteria for a given behavior, even though individual neurons of the group fail to meet the criteria. We suggest that such a group be termed a "command system" for the behavior in question. Individual neurons in the command system can be termed "com- mand elements" if, when fired in their normally occurring pattern, they elicit a part of the behavior, or "modulatory elements" if they do not in isolation elicit any response, but alter the behavior produced by other elements in the command system.
787 citations
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01 Jan 1978TL;DR: In this paper, a theory of molecular organic photochemistyr is presented, and a generalization of the Photochemistry of organic Molecules Index is presented for the first time.
Abstract: 1. Molecular Photochemistry of Organic Compounds: An Overview 2. Electronic, Vibrational, and Spin Configurations of Electronically Excited States 3. Transitions between States: Photophysical Processes 4. Radiative Transitions between Electronic States 5. Photophysical Radiationless Transitions 6. A Theory of Molecular Organic Photochemistyr 7. Energy Transfer and Electron Transfer 8. Mechanistic Organic Photochemistry 9. Photochemistry of Carbonyl Compounds 10. Photochemistry of Olefins 11. Photochemistry of Enones and Dienones 12. Photochemistry of Aromatic Molecules 13. Supramolecular Organic Photochemistry 14. Molecular Oxygen and Organic Photochemistry 15. A Generalization of the Photochemistry of Organic Molecules Index
TL;DR: In this article, it is shown that seafloor changes in the rates of sea-level rise or fall may be caused by changes in sedimentation rate, and that the position of the shoreline and the thickness of the sediments deposited during discrete time intervals may be computed as a function of the rate of sea level change and the sedimentation rates.
Abstract: It is commonly thought that transgressive or regressive events that may have occurred simultaneously on geographically dispersed continental margins have been caused by worldwide sea-level rise or fall, respectively. Instead, it is shown here that these events may be caused by changes in the rates of sea-level rise or fall. The subsidence of an Atlantic-type (passive) margin may be modeled as a bordering platform rotating downward about a landward hinge line. The rate of subsidence is greatest at the seaward side of the platform and decreases landward to zero at the hinge line. With the exception of sea-level changes due to glaciation, dessication, and flooding of small ocean basins and other sudden events, the rate of subsidence at the seaward edge of the platform (shelf edge) is greater than the rate at which sea level may possibly rise or fall. Thus, if sea level is falling, the shoreline will seek that point on the subsiding platform at which the rate of sea-level fall is equal to the rate of subsidence minus the sedimentation rate. If the rate of sea-level fall decreases, the shoreline will move landward; if the rate increases, the shoreline will migrate seaward. If sea level is rising, the shoreline will move to that point where the rate of sea-level rise is equal to the sedimentation rate minus the subsidence rate. Thus, if the rate of sea-level rise decreases, the shoreline will move seaward; if the rate increases, the shoreline will move landward. The position of the shoreline is also a function of the sedimentation rate. These relationships have been quantified so that the position of the shoreline and the thickness of the sediments deposited during discrete time intervals may be computed as a function of the rate of sea-level change and the sedimentation rate. A sea-level curve, based on volume changes of the mid-oceanic ridge system, has been computed. Sea level is seen to fall persistently from Late Cretaceous to middle Miocene time, but transgressions occur in Eocene and early Miocene time because the rate of sea-level fall is slower for these periods. It is concluded also that the presence of the shoreline seaward of the shelf edge of an Atlantic margin should be symptomatic of events that may cause rapid sea-level fall, such as glacial build-up or the sudden flooding of large deep basins.
TL;DR: Of patients who eventually died of tumor, those having “tubular” predominant lesions had the longest course (average 9 years before death, in contrast to 8 years for the “cribriform” and 5 years forThe “solid” tumors).
Abstract: 62 cases of adenoid cystic carcinoma (ACC) arising in major and minor salivary glands were studied. Factors which appeared to influence the clinical course included: 1) histologic pattern, 2) presence or absence of tumor on the surgical lines of excision, 3) site, 4) size of primary lesion, 5) presence or absence of tumor in lymph nodes, and 6) degree of cellular atypia. On histologic examination, these neoplasms were classified according to their predominant histologic pattern (tubular, cribriform or solid). Recurrences have been seen in 59% of patients with ACC demonstrating a predominantly “tubular” pattern, as compared to 89% for the “cribriform” lesions and 100% for the “solid” neoplasms. Of patients who eventually died of tumor, those having “tubular” predominant lesions had the longest course (average 9 years before death, in contrast to 8 years for the “cribriform” and 5 years for the “solid” tumors). Our findings suggest that the “tubular” predominant pattern has the best prognosis and represents the best differentiated histologic form of ACC. In contrast, the “solid” pattern is the least differentiated and is associated with the worst prognosis. The predominantly “cribriform” lesions appear to lie between the other two forms both clinically and histologically.
TL;DR: The efficacy of plotting cervical dilatation against time as a method of graphically analyzing labor is demonstrated and the value of this method for the study of individual labors, in progress, is stressed.
TL;DR: The reef-crest coral Acropora palmata from late Pleistocene reefs on Barbados has recorded the same global variations in oxygen isotopes as planktonic and benthonic foraminifera as discussed by the authors.
TL;DR: This paper is concerned with the kind of work that is needed in order to provide a more solid scientific foundation for the belief that life stress causes illness and to tackle a major substantive problem that has been largely neglected.
Abstract: We will start with a question: Do you believe that life stress can cause illness? If this question were included in a poll of either the general public or of concerned professionals, we would expect a nearly unanimous affirmative response; “nearly unanimous” only because if we asked a cross-section of the population whether they believed that the sun would rise tomorrow, probably someone would express doubt. At one time in human history, when belief in the rising of the sun was a matter of hope and faith, this doubt might have seemed reasonable. It no longer seems so because this daily event has long since become scientifically predictable. Can we say the same about the belief in the relation between life stress and illness? Is it firmly based on scientific evidence, or is it still a matter of faith? We will argue that at present the belief that life stress causes illness is based on faith bolstered by some scientific evidence. Given this argument, we will then describe the kind of work that seems to be needed in order to shift the balance to favor scientific evidence.
TL;DR: Inhibition appears to be due to a decrease in the number of available epidermal growth factor receptors rather than a change in receptor affinity, suggesting that certain biologic effects of tumor promoters may result from alterations in the function of cell surface receptors involved in growth regulation.
Abstract: Tumor-promoting phorbol esters and related plant macrocyclic diterpenes inhibit the binding of epidermal growth factor to its receptors on HeLa cells. This effect shows marked structural specificity and correlates with other biological effects of these compounds on mouse skin and in cell culture systems. The active compounds inhibited binding of 125I-labeled epidermal growth factor with a 50 per-cent effective dose in the range of 10(-8) to 10(-9) M. Inhibition appears to be due to a decrease in the number of available epidermal growth factor receptors rather than a change in receptor affinity. These results suggest that certain biologic effects of tumor promoters may result from alterations in the function of cell surface receptors involved in growth regulation.
TL;DR: The authors argue that marketing research has focused too narrowly on the static structure of attitude at the expense of its informational determinants, and they propose an experimental study to investigate the effec...
Abstract: The author argues that marketing research has focused too narrowly on the static structure of attitude at the expense of its informational determinants. An experimental study investigates the effec...
TL;DR: In this article, it was shown that the space Prim G of primitive ideals of C*(G) is a standard Borel space in the Borel structure generated by the hull-kernel topology, and the space Gao r of quasi-equivalence classes of normal representations (traceable factor representations) of C *(G), shown by Halpern [35] to be standard in the Mackey Borel structures.
Abstract: The fundamental problem in investigating the unitary representation theory of a separable locally compact group G is to determine its space G ̂ of (equivalence classes of) irreducible representations. I t is known that when G is not type I, G ̂ , with the Mackey Borel structure, is not standard, or even countably separated. This is generally interpreted to mean that the irreducible representations of such a group are not classifiable, and so the problem becomes to find a substitute for G ̂ , simple enough to afford some hope that it can be described completely, yet complicated enough to reflect a significant part of the representation theory of q. Two promising candidates have been proposed, both defined using the group C*-algebra C*(G) (which has the same representation theory as G): the space Prim G of primitive ideals of C*(G), which was shown by Effros [19] to be a standard Borel space in the Borel structure generated by the hull-kernel topology; and the space Gao r of quasi-equivalence classes of normal representations (traceable factor representations) of C*(G), shown by Halpern [35] to be standard in the Mackey Borel structure. (The results of [19] and [35] are actually valid for arbitrary separable C*-algebras, not just those arising from groups.) In the case that G is type I, both of these spaces may be naturally identified with G ̂ . Striking evidence that they are natural objects of s tudy may be found in the beautiful result [49] of Pukanszky, that for connected G they are \"the same\" in the sense that the map which associates to any element of Gno r the kernel of its members is a bijection of Gnor onto Prim C*(G). (It is easily shown that this bijoction is in fact a Borel isomorphism.)
TL;DR: The existence of a single active tk gene in tk+ transformants now facilitates an analysis of the sequence organization of tk- mutant cells and provides a useful model system for studies on the transfer of cellular genes.
TL;DR: The linear X-ray polarization of the Crab Nebula has been precisely measured at 2.6 keV and 5.2 keV with the OSO 8 graphite crystal polarimeters as discussed by the authors.
Abstract: The linear X-ray polarization of the Crab Nebula has been precisely measured at 2.6 keV and 5.2 keV with the OSO 8 graphite crystal polarimeters. The 1.4 ms time resolution of these instruments permitted the removal of any contribution to the polarization from the pulsar. The nebular polarization is 19.2% plus or minus 1.0% at a position angle of 156.4 plus or minus 1.4 deg at 2.6 keV. At 5.2 keV the corresponding results are 19.5% plus or minus 2.8% at 152.6 plus or minus 4.0 deg.
TL;DR: Three hypotheses are developed to specify the nature of the contingent relationships of project effectiveness and the results are consistent with an information processing approach to communication.
Abstract: Based on an information processing approach to organizations, this paper argues that project effectiveness is contingent on the match between the project's communication patterns and the nature of its work. Three hypotheses are developed to specify the nature of the contingent relationships. The results are consistent with an information processing approach to communication.
TL;DR: The present data suggest that the analgesia induced by stress is not identical to that of opiates, and low doses of naloxone completely abolish morphine-induced analgesia.
Abstract: Animals exposed to cold-water swims, rotation, or inescapable shocks, display analgesia comparable to that of 10 mg/kg of morphine. The present study investigated whether a narcotic antagonist would eliminate analgesia induced by cold-water swims. In one group of 12 rats, naloxone at 0, 1, 5, 10 and 20 mg/kg was administered at weekly intervals immediately preceding forced cold-water swims (2°C for 3.5 min) and alterations in flinch-jump thresholds were determined 30 min thereafter. In a second group of six rats, the effects of the same dose range of naloxone were determined upon normal flinch-jump thresholds. Naloxone dose-dependently attenuated the cold-water swim-induced analgesia up to a maximal reduction of 50% at 20 mg/kg. In contrast, all doses of naloxone had no effects upon normal flinch-jump thresholds. Since low doses of naloxone completely abolish morphine-induced analgesia, the present data suggest that the analgesia induced by stress is not identical to that of opiates.
TL;DR: In this article, the authors focused on Messinian-age erosional surfaces created by evaporitic drawdown of an isolated Mediterranean Sea and detected as discordances in seismic reflection profiles.
TL;DR: In this article, a column of water (14 km radius), within the central region of the Weddell Gyre west of Maud Rise, was observed in which the normal Antarctic stratification sequence of temperature-minimum to temperature-maximum was absent.
Abstract: In February 1977 a column of water (14 km radius), within the central region of the Weddell Gyre west of Maud Rise. was observed in which the normal Antarctic stratification sequence of temperature-minimum to temperature-maximum was absent. The column appeared as a cold, low-salinity, high-oxygen, cyclonic flowing (surface velocity above 50 cm s−1) eddy extending to at lest 4000 m. It is hypothesized that similar eddies were common in this region (at least in Austral summer 1977) and represent winter structures which have survived into the summer period. Eddy formation is explained as a product of winter period static instability, similar to the MEDOC observations in the Mediterranean, but without the subsequent sinking and spreading phase. Winter period static instability in the Weddell Gyre is shown to be a likely condition and may be related to the frequent occurrence of a large polynya within the central region of the Weddell Gyre. Deep penetration of winter surface water within the eddy supp...
TL;DR: Inhibition assays using tritiated hog H substance and various oligosaccharides were about 60 to 80 times more sensitive than assays by inhibition of precipitation and the Ulex lectin I site differs from the Lotus tetragonolobus site.
TL;DR: A behavioral process method was used to explore the relationship of individual difference factors to consumer information acquisition behavior and found increased information acquisition was related to the product's importance for the individual.
Abstract: A behavioral process method was used to explore the relationship of individual difference factors to consumer information acquisition behavior. Findings included: (1) the mean proportion of availab...
TL;DR: Left side composites were judged to be more emotionally intense than right side Composites, which points to hemispheric asymmetry in the control of emotional expression and has implications for the role ofotional expression in communication.