Showing papers by "University of Michigan published in 1968"

Attitudinal effects of mere exposure.

Abstract: The hypothesis is offered that mere repeated exposure of the individual to a stimulus object enhances his attitude toward it. By \"mere\" exposure is meant a condition making the stimulus accessible to the individual's perception. Support for the hypothesis consists of 4 types of evidence, presented and reviewed: (a) the correlation between affective connotation of words and word frequency; (b) the effect of experimentally manipulated frequency of exposure upon the affective connotation of nonsense words and symbols; (c) the correlation between word frequency and the attitude to their referents j (d) the effects of experimentally manipulated frequency of exposure on attitude. The relevance for the exposure-attitude hypothesis of the exploration theory and of the semantic satiation findings were examined.

Stereochemical criteria for polypeptides and proteins. V. Conformation of a system of three linked peptide units.

Abstract: The general conformations of a system of three linked peptide units are studied, and it is found that there are three types of conformations which contain NH…O hydrogen bonding between the first and the third units. One of them is part of a 310-helix, while the other two arc nonhelical. The two nonhelical conformations are very similar, and in both the cases the peptide chain turns around, reversing the direction of progress. Such a conformation can therefore occur in the region where a polypeptide chain folds back on itself, as in the cross-β structure. The method of representing these interesting tripeptide conformations in a (ϕ,ψ) map is described. Examples of such hydrogen-bonded, nonhelical conformations which occur in peptides and proteins are discussed—e.g., in cyclohexaglyeyl, an open tetrapeptide Gly-L-Pro-L-Leu-Gly, and in parts of the lysozyme chain.

Radioimmunoassay for Rat Luteinizing Hormone with Antiovine LH Serum and Ovine LH-131I∗:

Abstract: SummaryA highly sensitive and specific radioimmunoassay for rat LH has been developed utilizing antiovine LH serum and ovine LH for iodination. Estimates of the LH potency of pituitary preparations...

The Transmission of Political Values from Parent to Child

Abstract: In understanding the political development of the pre-adult one of the central questions hinges on the relative and differentiated contributions of various socializing agents. The question undoubtedly proves more difficult as one traverses a range of polities from those where life and learning are almost completely wrapped up in the immediate and extended family to those which are highly complex social organisms and in which the socialization agents are extremely varied. To gain some purchase on the role of one socializing agent in our own complex society, this paper will take up the specific question of the transmission of certain values from parent to child as observed in late adolescence. After noting parent-child relationships for a variety of political values, attention will be turned to some aspects of family structure which conceivably affect the transmission flows. I. Assessing the Family's Impact: “Foremost among agencies of socialization into politics is the family.” So begins Herbert Hyman's discussion of the sources of political learning.1 Hyman explicitly recognized the importance of other agents, but he was neither the first nor the last observer to stress the preeminent position of the family. This viewpoint relies heavily on both the direct and indirect role of the family in shaping the basic orientations of offspring. Whether the child is conscious or unaware of the impact, whether the process is role-modelling or overt transmission, whether the values are political and directly usable or “nonpolitical” but transferable, and whether what is passed on lies in the cognitive or affective realm, it has been argued that the family is of paramount importance.

A statistical model which combines features of factor analytic and analysis of variance techniques

Abstract: This paper describes a method of matrix decomposition which retains the ability of factor analytic techniques to summarize data in terms of a relatively low number of coordinates; but at the same time, does not sacrifice the useful analysis of variance heuristic of partitioning data matrices into independent sources of variation which are relatively simple to interpret. The basic model is essentially a two-way analysis of variance model which requires that the matrix of interaction parameters be decomposed by using factor analytic techniques. Problems of judging statistical significance are discussed; and an illustrative example is presented.

Screening of surface waves in soils

Abstract: Field model tests were performed to determine the effectiveness of trenches in shielding against vibrations transmitted through the ground. In tests designated as active isolation, annular trenches surrounding a vibrating footing were used to reduce the amplitude of vibrations transmitted away from the footing. In tests designated as passive isolation, straight trenches were used as barriers at a distance from a vibrating footing to shield a designated zone. Two indicators of screening effectiveness were studied: (1) The degree of reduction in vibration amplitude, and (2) the shape and extent of the screened zone. In all tests the shallowest trench which provided a prescribed degree of shielding was determined. Trenches were compared on the basis of dimensionless geometrical parameters formed by relating trench dimensions to the wave length of the Rayleigh wave. The relative effectiveness of open trenches and sheet-wall barriers of the same size was also studied.

Aerodynamic shattering of liquid drops.

Abstract: High velocity gas stream induced shattering of liquid drops, disintegration rate and breakup time

Cell migrations to the isocortex in the rat.

Abstract: Cells that took up tritiated thymidine (H-3T) at various periods of intrauterine and early infant life in the periventricular proliferative zone and migrated to form the isocortex in the rat were tracked autoradiographically in series of stages to characterize their movements. Cells labeled at any stage soon separated themselves into cohorts, some continuing to proliferate, others migrating at once, and still others delaying before migrating. Migratory cells moved to the developing cortex along the curved and oblique paths of the pallial fibers, whose basic plan was established by the early thalamocortical fibers. Magnitude of speed was 15 to 30 μ per hour. The primitive neural cells that originated on each of the fourteenth to eighteenth intrauterine days first reached the cortex in about 48 hours, others took two or three days longer. Migrations originating on the nineteenth to twenty-first days continued into the week after birth; as the primitive cells approached the cortex, however, they differentiated into young neurons, and traveled perpendicularly to its outer part. The first cohort of twentieth day labeled cells reached their intracortical destinations in about three days, the last in about ten days. The isocortex was formed essentially from within outward. The first neuroglia destined for the isocortex arose on the twenty-first intrauterine day.

Political Socialization and the High School Civics Curriculum in the United States

Abstract: Attempts to map the political development of individuals inevitably become involved with the relative contribution of different socialization agencies throughout the life cycle. Research has focused to a large extent on the family and to a much lesser degree on other agents such as the educational system. At the secondary school level very little has been done to examine systematically the selected aspects of the total school environment. To gain some insight into the role of the formal school environment, this paper will explore the relationship between the civics curriculum and political attitudes and behavior in American high schools. A number of studies, recently fortified by data from Gabriel Almond and Sidney's Verba's five-nation study, stress the crucial role played by formal education in the political socialization process. [None of the other variables] compares with the educational variable in the extent to which it seems to determine political attitudes. The uneducated man or the man with limited education is a different political actor from the man who has achieved a high level of education.1 Such conclusions would not have greatly surprised the founders of the American republic, for they stressed the importance of education to the success of democratic and republican government. Starting from its early days the educational system incorporated civic training. Textbooks exposing threats to the new republic were being used in American schools by the 1790's. By 1915, the term “civics” became associated with high school courses which emphasized the study of political institutions and citizenship training.2

“Good” Probability Assessors

Abstract: Since a meteorologist's predictions are subjective, a framework for the evaluation of meteorological probability assessors must be consistent with the theory of subjective probability. Such a framework is described in this paper. First, two standards of “goodness,” one based upon normative considerations and one based upon substantive considerations, are proposed. Specific properties which a meteorologist's assessments should possess are identified for each standard. Then, several measures of “goodness,” or scoring rules, which indicate the extent to which such assessments possess certain properties, are described. Finally, several important uses of these scoring rules are considered.

Hemodynamic studies in patients with borderline blood pressure elevation.

Abstract: Ninety-four patients with occasionally elevated (borderline) blood pressure, 61 patients with asymptomatic established hypertension, and 63 normal subjects have been studied at rest and during a progressive exercise test on a cycle ergometer. Subjects with borderline blood pressure had increased cardiac output in the resting recumbent position, but this was not maintained in the sitting position or during exercise. In the resting recumbent position there was overlap in the total peripheral resistance of normal subjects and patients with borderline blood pressure, but when analyzed in relation to the cardiac output, the total peripheral resistance of patients with borderline blood pressure was significantly elevated. In the sitting position the peripheral resistance of the patients with borderline blood pressure was elevated and remained elevated during light exercise, but fell into the normal range at higher loads. In this respect patients with borderline blood pressure differed from hypertensive patients...

Posterior Distribution of Percentiles: Bayes' Theorem for Sampling From a Population

Abstract: A Bayesian approach to inference about the percentiles and other characteristics of a finite population is proposed. The approach does not depend upon, though it need not exclude, the use of parametric models.Some related questions concerning the existence of exchangeable distributions are considered. It is shown that there are no countably additive exchangeable distributions on the space of observations which give ties probability 0 and for which a next observation is conditionally equally likely to fall in any of the open intervals between successive order statistics of a given sample.

Scheduling Parallel Computations

Abstract: A model for parallel computations is given as a directed graph in which nodes represent elementary operations, and branches, data channels. The problem considered is the determination of an admissible schedule for such a computation; i.e. for each node determine a sequence of times at which the node initiates its operation. These times must be such that each node, upon initiation, is assured of having the necessary data upon which to operate. Necessary and sufficient conditions that a schedule be admissible are given. The computation rate of a given admissible schedule is defined and is shown to have a limiting value 1/p where p is a parameter dependent upon the cycles in the graph. Thus, the computation cannot proceed at a rate exceeding 1/p. For g ≥ p, the class of all periodic admissible schedules with period g is characterized by the solution space of a certain system of linear inequalities. In particular, then, the maximum computation rate of 1/p is attainable under a periodic admissible schedule with period p. A class of all-integer admissible schedules is given. Finally, an algorithm is given for the determination of the number of initiations of each node in the graph defining a parallel computation. An example for a system of difference equations is given in detail.

Some conceptual difficulties in the theory of social conflict

Abstract: classification. For example, industrial conflict (employer vs. employed) can appear under any of the abstract types, since either party can be a person, group, or organization (Boulding, 1962, p. 213). International conflict can fall under either homogeneous or heterogeneous organization conflict, depending on whether the parties (which may be tribes, feudal states, universal agricultural empires, industrial powers, or superpowers) are equal, unequal, or hopelessly unequal (pp. 227-229). The conflict of ideological systems is partly ecological, partly organizational (p. 278). In Boulding’s view, these empirical types (which do not represent an exhaustive list) are different enough from each other to require separate treatment. Whether this dual classification implies 8 -f4 special theories, 8 X 4 special theories, or some intermediate or larger number, is not at all clear. The mode of abstraction represented in Boulding’s eight-type scheme has been carried a step further. One need only distinguish two types of parties-individuals vs. collective entities (e.g., Sorokin’s distinction between persons and groups). Similarly, the structural relations between parties can be reduced to a simple dichotomy : either the conflicting parties are members of a larger system or else they are separate, autonomous entities which happen to interact in a common environment. This latter distinction has appeared (under various labels) in many schemes: distinctions such as those between intragroup and intergroup conflict (Simmel, 1955; Coser, 1956), intraparty and interparty conflict (Mack and Snyder, 1957), conflict within a social unit and conflict between social units (Levinger, 1957), or internal conflict (&dquo;quandaries&dquo;) and conflicts between parties (Boulding, 1957), all reflect the same basic dichotomy. By combining these two basic dichotomies, one arrives at a simple classification containing four types of conflict, as illustrated by Galtung (1965b, p. 348), who presents the following table: By ignoring the differences among concrete types which could appear in the bottom row, this table implies a smaller number of special theories than any scheme so far discussed. Galtung’s four-cell scheme is not merely a condensation of Boulding’s eight abstract types, but rather a partial condensation combined with the addition of new types. On one axis (nature of parties), Galtung has simply ignored Boulding’s distinction between groups and organizations, replacing these with a single category, i.e., &dquo;collectivities.&dquo; Furthermore, he ignores the distinction between homogeneous and heterogeneous pairs of parties. The result is that one of Boulding’s types of conflict (interpersonal) is retained in Galtung’s scheme, while the remaining seven types are apparently subsumed under a single category (intersystem, collective level). Thus Galtung’s scheme reduces Boulding’s eight types to only two by ignoring certain distinctions. On the other axis (structural relations between parties), Galtung introduces new types by attending to an aspect (intrasystem vs. intersystem) which is at best only implicit in Boulding’s scheme. Thus intrapersonal conflict is not one of Boulding’s eight types (even though he does discuss intrapersonal conflict as a factor which influences the behavior of indi-

Threshold pressure phenomena in porous media

Abstract: Threshold displacement pressures are needed to determine how much over-pressure can be used in storing natural gas. An experimental technique for determining threshold pressures by displacing water with gas from samples saturated with water is presented. Threshold pressures for 8 low permeability samples were measured. Threshold pressure data obtained in this work plus data on higher permeability samples reported in the literature are correlated with porosity, permeability, surface tension, and formation resistivity factor. Mercury injection pressures were also measured and correlated with air- water threshold pressures. A study of the effect of time on threshold pressures show that they are independent of time. An aerial photography of gas emerging from the top of a core shortly after its threshold pressure has been exceeded shows that the gas bubbles are uniformly distributed across the face of the core. Channeling will occur, however, when an increased gas phase permeability is reached. A porous medium can be resealed after its threshold pressure has been reached, provided it has not been desaturated below a fixed saturation. (18 refs.)

Boundary layer control of flow separation and heat exchange

Abstract: Boundary layer control for delay or prevention of flow separation and/or increase in rate of heat exchange between a surface and a fluid by an arrangement of surface elements which may take the form of either crests or discreet concave depressions in the surface, having effective depths or dimensions of less that of the adjacent boundary layer thickness, to cause the formation of vortices with succeeded surface elements being positioned to cause vortex amplification, for effective boundary layer mixing with less drag, weight penalty, noise, and energy loss than that of conventional vane-type generators.

An Application of Mixed-Integer Programming Duality to Scheduling Thermal Generating Systems

Abstract: A decomposable mixed-integer programming model for simultaneous economic consideration of unit commitment and short-term dispatch of thermal power generating equipment is presented. An optimum solution procedure is described which takes advantage of the structure of the model and promises computational efficiency in practical applications. Characterizing the demand forecast as a discretized function permits a probabilistic forecast to be incorporated in the scheduling model. The model minimizes the total expected costs of start-up, shutdown, and unit operating costs subject to the demand, reserve, and unit commitment constraints. Extensions to multiple periods and to include additional constraints such as time dependent start-up costs and geographic constraints are given.