Showing papers by "University of Chicago published in 1969"
TL;DR: In this paper, the authors examine the process by which common stock prices adjust to the information (if any) that is implicit in a stock split and show that the independence of successive price changes is consistent with a market that adjusts rapidly to new information.
Abstract: There is an impressive body of empirical evidence which indicates that successive price changes in individual common stocks are very nearly independent. Recent papers by Mandelbrot and Samuelson show rigorously that independence of successive price changes is consistent with an "efficient" market, i.e., a market that adjusts rapidly to new information. It is important to note, however, that in the empirical work to date the usual procedure has been to infer market efficiency from the observed independence of successive price changes. There has been very little actual testing of the speed of adjustment of prices to specijc kinds of new information. The prime concern of this paper is to examine the process by which common stock prices adjust to the information (if any) that is implicit in a stock split
4,470 citations
Book•
01 Jan 1969TL;DR: In the field of mental health, the split between hedgehogs and foxes roughly parallels that between theorists and empiricists as discussed by the authors, and the hedgehog's attempt to bridge that gap and pursue systematic data collection within the framework of a single unifying concept.
Abstract: Preface Sir Isaiah Berlin has observed that there are deep differences in the ways in which people approach life, and that it may be useful to think of these ways as falling into two large groups-the way of the hedgehog and the way of the fox. Hedgehogs approach problems in an integrative manner, trying to bring everything into a single, universal, organizing principle that gives unity to the manifest diversities of life. Foxes, on the other hand, approach problems in a differentiating manner and pursue many disparate problems with little concern for haw they fit together or might fit into a larger integrated whole. Hedgehogs look for the unity in diversity; foxes look for the diversity that underlies the unity. In the field of mental health, the split between hedgehogs and foxes roughly parallels that between theorists and empiricists. The grand theorists such as Freud and Jung were militant hedgehogs. However, a review of the empirical literature in mental health, such as that by Jahoda (1958), shows the field to be dominated by foxes. This unfortunate split between hedgehog-theorists and fox-empiricists has resulted in unifying theories that dangerously approach explaining everything, and thus explaining nothing, or in disparate empirical findings that do not add up to anything. Too often theories are divorced from data, and data are collected with little regard for their theoretical import. This book is a hedgehog's attempt to bridge that gap and pursue systematic data collection within the framework of a single unifying concept. This concept-psychological well-being, or happiness has been of great concern to men since recorded history began and has been the object of vast amounts of thought and research for centuries. It is a logical concept to employ in the study of phenomena related to current concerns with mental health and mental illness, and one that is very congenial to the hedgehog mind. The particular conception of psychological well-being that is elaborated in this monograph emerges from a pilot study conducted by NORC (Bradburn and Caplovitz. 1965), which vi Preface attempted to develop instruments for measuring mental health in the population. Analysis of the data from that study led to a conceptualization of psychological well-being as a resultant of two almost completely unrelated dimensions of affect, which we called positive and negative feelings. The results of that study were sufficiently encouraging to suggest that further research along these lines would be productive. At …
4,191 citations
TL;DR: Effectiveness of any control program will depend on the different responses of the crop, pest, and control organism to this pattern of environment, which there are geographic, local, and temporal variations in the environment.
Abstract: Economically important pests usually attack a crop or group of crops over a wide region in which there are geographic, local, and temporal variations in the environment. Effectiveness of any control program will therefore depend on the different responses of the crop, pest, and control organism to this pattern of environment. Usually the environmental heterogeneity is treated as an unavoidable complication in program evaluation, and attempts are made to work with “average” conditions.
3,149 citations
Book•
01 Aug 1969TL;DR: The first large experimental inquiry carried out by the methods of factor analysis described by Thurstone in The Vectors of the Mind as discussed by the authors was made possible by financial grants from the Social Science Research Committee of the University of Chicago, the American Council of Education, and the Carnegie Corporation of New York.
Abstract: This publication is the opening number of a series which the Psychometric Society proposes to issue. It reports the first large experimental inquiry, carried out by the methods of factor analysis described by Thurstone in The Vectors of the Mind 1. The work was made possible by financial grants from the Social Science Research Committee of the University of Chicago, the American Council of Education, and the Carnegie Corporation of New York. The results are eminently worthy of the assistance so generously accorded. Thurstone’s previous theoretical account, lucid and comprehensive as it is, is intelligible only to those who have a knowledge of matrix algebra. Hence his methods have become known to British educationists chiefly from the monograph published by W. P. Alexander8. This enquiry has provoked a good deal of criticism, particularly from Professor Spearman’s school ; and differs, as a matter of fact, from Thurstone’s later expositions. Hence it is of the greatest value to have a full and simple illustration of his methods, based on a concrete inquiry, from Professor Thurstone himself.
2,082 citations
TL;DR: In this article, the dispersion relations for surface plasma oscillations in normal metals are investigated for single-and multiple-film systems taking retardation effects into account, and two types of possible modes of oscillation are found.
Abstract: The dispersion relations for surface plasma oscillations in normal metals are investigated for single- and multiple-film systems taking retardation effects into account. The simple dielectric function $\ensuremath{\epsilon}(\ensuremath{\omega})=1\ensuremath{-}\frac{{{\ensuremath{\omega}}_{p}}^{2}}{{\ensuremath{\omega}}^{2}}$ is found to be adequate for the high-frequency region in which oscillations remain undamped. Two types of possible modes of oscillation are found. One type corresponds to dispersion relations which behave linearly for not-so-high frequency, with a phase velocity always smaller than the velocity of light in the dielectric, but at least ten times larger than the Fermi velocity, while the other type consists of high-frequency modes ($\ensuremath{\omega}\ensuremath{\sim}{\ensuremath{\omega}}_{p}$). The role of these oscillations in the problem of transition radiation is reexamined. In the case of a thin metal film, a new interpretation is proposed for the peak observed in the transition radiation spectrum. Finally, the work is extended to superconducting metals where, in the frequency range $\ensuremath{\hbar}\ensuremath{\omega}l2\ensuremath{\Delta}$ ($2\ensuremath{\Delta}$ is the superconducting energy gap), we have justified the use of a dielectric function of the same functional form as given above but with ${{\ensuremath{\omega}}_{p}}^{2}$ replaced by an almost frequency-independent quantity ${{\ensuremath{\omega}}_{\mathrm{ps}}}^{2}$, where ${\ensuremath{\omega}}_{\mathrm{ps}}=\frac{c}{{\ensuremath{\lambda}}_{\mathrm{ps}}}$ and ${\ensuremath{\lambda}}_{\mathrm{ps}}$ is the actual penetration depth. In this frequency range, the oscillations are essentially undamped and play an important role in the electromagnetic properties of the multiple-film systems, and particularly when the systems exhibit the ac Josephson effect.
1,258 citations
TL;DR: In this paper, the Clausius-Mossotti theory of the electronic dielectric constant of diatomic crystals is extended to the case of the diamond, zincblende, wurtzite, and rock-salt types.
Abstract: Electronegativity difference is redefined as a scaling parameter, generalizing the concept of valence difference. A procedure for its evaluation is developed in terms of the dielectric constants of diatomic crystals. A simple alternative to the Clausius-Mossotti theory of the electronic dielectric constant is developed in terms of this concept. The effect of $d$-electron states and of hydrostatic pressure are discussed, and procedures for their approximate evaluation are developed. The treatment is extended to 68 crystals of the diamond, zincblende, wurtzite, and rock-salt types; values of the electronegativity parameter are tabulated for these crystals.
829 citations
TL;DR: Amorphous covalent alloys particularly of group-IV, -V, and -VI elements are readily formed over broad ranges of composition and have been described as low-mobility electronic intrinsic semiconductors with a temperature-activated electrical conductivity σ = σ 0×exp(-ΔE/kT) which sometimes extends well into the molten state as discussed by the authors.
Abstract: Amorphous covalent alloys particularly of group-IV, -V, and -VI elements are readily formed over broad ranges of composition.1–6 They have been described as low-mobility electronic intrinsic semiconductors with a temperature-activated electrical conductivity σ = σ 0×exp(-ΔE/kT) which sometimes extends well into the molten state.2,3,7 They remain intrinsic with changed ΔE when their composition is changed.1,5,7 These alloys transmit infrared light up to an exponential absorption edge from which an energy gap E g is estimated.1,2 The value of E g usually is smaller than 2ΔE, often by as much as 10–20%.7,8 Photoconductivity9 and recombination-radiation10 measurements have been interpreted as giving evidence for the presence of localized states in the gap.
828 citations
TL;DR: In this paper, a simple model for a semiconductor-metal transition, based on the existence of both localized (ionic) and band (Bloch) states, was proposed, which differs from other theories in that we assume the one-electron states to be essentially unchanged by the transition.
Abstract: We propose a simple model for a semiconductor-metal transition, based on the existence of both localized (ionic) and band (Bloch) states. It differs from other theories in that we assume the one-electron states to be essentially unchanged by the transition. The electron-hole interaction is responsible for the anomalous temperature dependence of the number of conduction electrons. For interactions larger than a critical value, a first-order semiconductor-metal phase transition takes place.
701 citations
Book•
01 Jan 1969TL;DR: In this article, the authors make a study of rings satisfying certain ascending chain conditions and show that the decisive and incisive results are three theorems due to Goldie, and the main part of the chapter is devoted to a presentation of these.
Abstract: In this chapter we shall make a study of rings satisfying certain ascending chain conditions. In the non-commutative case-and this is really the only case with which we shall be concerned- the decisive and incisive results are three theorems due to Goldie. The main part of the chapter will be taken up with a presentation of these.
661 citations
TL;DR: This work has found what seems to be a new class of dynamically stable systems, which suggests that even haphazardly constructed control nets of high molecular specificity undergo homeostasis and differentiation.
Abstract: THE genome is a complex net of interacting components commonly thought to control homeostasis and differentiation through precisely constructed control circuits among the genes1–6. But I have found what seems to be a new class of dynamically stable systems, which suggests that even haphazardly constructed control nets of high molecular specificity undergo homeostasis and differentiation.
637 citations
TL;DR: For calcite-water at 25°C and 0°C, 1000 ln α = 28.1 and 33.7, respectively, both values in excellent agreement with the Urey-Epstein paleotemperature scale as mentioned in this paper.
TL;DR: The appearance of circular Moiré fringes when a random dot pattern is superimposed on itself provides new evidence that the human visual process may include the computation of local autocorrelations by excitation of line detectors.
Abstract: The appearance of circular Moire fringes when a random dot pattern is superimposed on itself provides new evidence that the human visual process may include the computation of local autocorrelations by excitation of line detectors.
TL;DR: The antagonistic action of antiandrogens strongly supports the contention that the binding of 5α-dihydrotestosterone by proteins described in this paper is germane to the stimulation of prostate growth and function by androgens.
TL;DR: Omt purpose is to describe in detail a convenient procedure for performing a new kind of item analysis that is different in a vital way from that described in textbooks like Gulliksen's Theory of Mental Tests and used in computing programs like TSSA2.
Abstract: Omt purpose is to describe in detail a convenient procedure for performing a new kind of item analysis. This new item analysis is different in a vital way from that described in textbooks like Gulliksen’s Theory of Mental Tests and used in computing programs like TSSA2. The difference is that (a) test calibrations are independent of the sample of persons used to estimate item parameters, and (b) person measurements, the transformation of test scores into estimates of person ability, are independent of the selection of items used to obtain test scores.
TL;DR: The history of criticism of the Federal Trade Commission is almost as interesting as the history of the agency itself as discussed by the authors, and the persistence of these criticisms would seem to indicate-largely impervious to criticism.
Abstract: The history of criticism of the Federal Trade Commission is almost as interesting as the history of the agency itself. The landmarks are Gerard Henderson's 1924 study, the Hoover Commission's 1949 Report, the Landis Report in 1960, the Auerbach Report in 1964, the Nader Report in 1969, and, most recently, the Report of the American Bar Association's Commission to study the FTC.1 What is remarkable about these studies, which span a period of 45 years, is the sameness of their conclusions. To be sure, with the resurgence of the consumer movement in the 1960's, a shift in critical emphasis from the agency's antitrust to its consumer-protection activities becomes discernible. But the diagnosis remains the same. The Commission is rudderless; poorly managed and poorly staffed; obsessed with trivia; politicized; all in all, inefficient and incompetent. And -the persistence of these criticisms would seem to indicate-largely impervious to criticism. My excuse for adding still another entry to the list of critiques of the Trade Commission is that the main critical tradition, which I have just described, seems to me wide of the mark. The previous
TL;DR: In this paper, the authors consider the factors that motivate commuters to use their cars to go to work as against some form of mass transport, such as time, cost, and other considerations.
Abstract: A large number of analyses in the social sciences are concerned with the determinants of the probability that a particular event will occur. For example, one may be interested in the forces which motivate commuters to use their cars to go to work as against some form of mass transport. Time, cost, and other considerations will play a role. Let p be the probability that a car is used, and hence 1 — p the probability that mass transport is preferred; then one may want to apply a linear specification of the form
$$p = a + b{{{T_1}} \over {{T_2}}} + c{{{C_1}} \over {{C_2}}} + {d_1}{Q_2} + {d_2}{Q_2} + {d_3}{Q_3},$$
where T 1 and T 2 are the times (minutes per day) needed for the two competing modes of transportation, C 1 and C 2 their costs (dollars per day), and Q l, Q 2, and Q 3 commuter characteristics which are considered to be relevant to the choice (income, family size, etc.).
TL;DR: The apparent turnovers of mitochondrial DNA and of the phospholipids, cardiolipin, lecithin, and phosphatidyl ethanolamine, have been determined simultaneously in the mitochondria of rat liver, kidney, brain, and heart.
TL;DR: Interstellar formaldehyde has been detected in absorption against numerous galactic and extragalactic radio sources by means of the ground-state rotational transition at 4830 MHz as mentioned in this paper.
Abstract: Interstellar formaldehyde (${\mathrm{H}}_{2}$CO) has been detected in absorption against numerous galactic and extragalactic radio sources by means of the ${1}_{11}$-${1}_{10}$ ground-state rotational transition at 4830 MHz. The absorbing regions often correspond in velocity with 18-cm OH features. ${\mathrm{H}}_{2}$CO is the first organic polyatomic molecule ever detected in the interstellar medium and its widespread distribution indicates that processes of interstellar chemical evolution may be much more complex than previously assumed.
TL;DR: Investigative studies with human islet cell tumours and foetal calf pancreas have shown that insulin is formed from proinsulin, a single-chain polypeptide precursor, and the amino-acid sequences of porcine7 and bovine8 proins insulin have been determined.
Abstract: BIOSYNTHETIC studies with human islet cell tumours1,2, rat2,3 and codfish4 islets, and foetal calf pancreas5 have shown that insulin is formed from proinsulin, a single-chain polypeptide precursor. This protein has subsequently been purified from commercial preparations of crystalline insulin6, and the amino-acid sequences of porcine7 and bovine8 proinsulin have been determined. The molecule begins at the N-terminus with the B-chain sequence of insulin, terminates with the insulin A-chain and bears a connecting segment of thirty (bovine) or thirty-three (porcine) amino-acids linking the two chains. Although 30 per cent of the amino-acid sequences of these connecting segments differ, identical pairs of basic amino-acids occur at each end in both species. Limited tryptic digestion in each case liberates desalanyl–insulin, alanyl–arginine, free arginine and the remainder of the connecting segment as an intact peptide6,7.
TL;DR: The correspondence between prediction and data suggests that the higher order interactions have slight or no effect on the dynamics of this artificial community of ciliates.
Abstract: An empirical test of the existence of higher order interactions was carried out using four ciliate protozoans, Paramecium caudatum, P. bursaria, P. aurelia, and Blepharisma sp. All four ciliates were cultured individually, and their population histories were described quite well by the simple logistic equation. Attempts to explain minor deviations of the data from the logistic by use of the one or two time lag logistic failed. A more complicated time lag phenomenon must be operative. Every possible pair of the four ciliates was cultured and a trial and error procedure was used to estimate @a and @b of the Gause equations. In all cases the simple Gause equations seemed adequately to describe the data. All four ciliates were cultured together and compared to predictions made by use of the competition coefficients estimated from pair—wise competition and population parameters estimated from single species population growth. The correspondence between prediction and data suggests that the higher order interactions have slight or no effect on the dynamics of this artificial community.
TL;DR: A model developed in the present paper is one in which the map arises from wave-like propagation of activity from localized clocks or pacemakers, and has a high informational capacity and is readily applied to the discussion of particular developmental phenomena.
TL;DR: In this paper, the spin-orbit interaction is considered in terms of a Hilbert transform of the spectrum of unperturbed dipole matrix elements weighted by the effect of spinorbit interaction and the theory of this parameter is adapted from Fermi's interpretation of doublet intensity ratios and from Seaton's related interpretation of photoabsorption minima.
Abstract: Photoelectrons emitted by Cs vapor exposed to circularly polarized light with $2750\ensuremath{\lesssim}\ensuremath{\lambda}\ensuremath{\lesssim}3150$ \AA{} should have spin orientation $\ensuremath{\gtrsim}85%$ parallel to the light's angular momentum. Measurements of this orientation along the spectrum may be represented by a parameter $x$ defined theoretically in terms of a Hilbert transform of the spectrum of unperturbed dipole matrix elements weighted by the effect of spin-orbit interaction. The theory of this parameter is adapted from Fermi's interpretation of doublet intensity ratios and from Seaton's related interpretation of photoabsorption minima. Semiquantitative estimates are drawn from experimental data on photoabsorption.
TL;DR: Elevated calculated tension per lamellar unit and excessive avascular thickness may be factors in the increased susceptibility of human abdominal aortas to atherosclerosis.
Abstract: Previous studies of adult mammalian thoracic aortas revealed that tension per medial lamellar unit was independent of species and that distribution of medial vasa vasorum, number of medial lamellar units and medial thickness were consistently related. Except for man, a similar pattern prevailed in abdominal aortic segments of all of the ten species studied. The human abdominal aortic media had relatively fewer lamellar units for its diameter than abdominal or thoracic aortas of other species, resulting in a relatively elevated estimated mean tension per lamellar unit. Vasa were normally absent from the human abdominal aortic media, even though its thickness significantly exceeded the thickness of avascular medias of other species and of avascular zones of medias with vasa vasorum. Elevated calculated tension per lamellar unit and excessive avascular thickness may be factors in the increased susceptibility of human abdominal aortas to atherosclerosis.
TL;DR: In this article, the aragonite and calcite were precipitated from bicarbonate solutions by slow removal of carbon dioxide at 25°C, and theoretical calculation of the calcite-aragonite fractionation gives 0.9.
TL;DR: The concept of “induced derepression” is proposed to explain how the nuclear transformation of 4S to a 5S estradiol-protein complex might initiate uterine growth.
TL;DR: A new revolution is under way in American political science as mentioned in this paper, which is referred to as the post-behavioral revolution, and it is directed against a developing behavioral orthodoxy in the discipline of political science.
Abstract: A new revolution is under way in American political science. The last revolution—behavioralism—has scarcely been completed before it has been overtaken by the increasing social and political crises of our time. The weight of these crises is being felt within our discipline in the form of a new conflict in the throes of which we now find ourselves. This new and latest challenge is directed against a developing behavioral orthodoxy. This challenge I shall call the post-behavioral revolution.The initial impulse of this revolution is just being felt. Its battle cries are relevance and action. Its objects of criticism are the disciplines, the professions, and the universities. It is still too young to be described definitively. Yet we cannot treat it as a passing phenomenon, as a kind of accident of history that will somehow fade away and leave us very much as we were before. Rather it appears to be a specific and important episode in the history of our discipline, if not in all of the social sciences. It behooves us to examine this revolution closely for its possible place in the continuing evolution of political science. Does it represent a threat to the discipline, one that will divert us from our long history in the search for reliable understanding of politics? Or is it just one more change that will enhance our capacity to find such knowledge?
TL;DR: In this paper, the homologies of differential algebras and of differential modules over differential algesbras have not only products but also higher order operations, namely Massey products, which have been largely ignored because of the difficulty in computing them and because of their lack of conceptual interest.
TL;DR: In this paper, the surface states bands in insulators induced by image potential were determined lower limits for liquid and solid gases. But the lower bound was not defined for both liquids and solids.
Abstract: Electron surface states bands in insulators induced by image potential, determining lower limits for liquid and solid gases