Showing papers by "University of California published in 1982"

Why Africa's Weak States Persist: The Empirical and the Juridical in Statehood

Abstract: State institutions and organizations in Black Africa are less developed than almost anywhere else, and political instability has been prevalent. Yet, these serious empirical weaknesses have not led to enforced jurisdictional change. In order to explain the persistence of some of the weakest states in the world, the authors argue that state jurisdictions in Black Africa have been maintained primarily by the international society of states. Unlike the states that formed in Europe at an earlier period, many Black African states evolved—and survived—in the absence of effective national governments. Whereas state jurisdictions and international society once were consequences of the success and survival of states, today in Black Africa—and perhaps elsewhere, especially in the Third World—they are more likely to be conditions.

On the Corporate Demand for Insurance

Abstract: Insurance contracts are regularly purchased by corporations. The Insurance Information Institute reports that “business insurance accounted for approximately 54.2 percent of the $79, 032,923,000 in direct property and liability insurance premiums written in the United States in 1978” (1979, p. 9). Yet even though annual premiums exceeded $42.8 billion,1 the importance of these contracts has been largely ignored by the finance profession. For example, the topic of insurance is completely absent from the index of virtually all corporate finance textbooks.

Student Interaction and Learning in Small Groups

Abstract: A key feature distinguishing cooperative settings from other learning settings is the opportunity for interaction among students. Yet, a look at the last several decades of research on classroom interaction and achievement reveals that researchers have only recently begun to devote much attention to interaction among students in cooperative groups. Recent studies of student interaction in small groups have uncovered some significant relationships between student interaction and achievement. Although some studies have produced significant results, the overall picture of the importance of student interaction in achievement is somewhat mixed. Part of the reason for the mixed picture is the generality of the measures of student interaction. Most studies have not used specific measures of student interaction that reflect the amount of elaboration contained in students’ interaction with one another. Further, the measures of student interaction used in most studies have typically reflected isolated behaviors rather than sequences of interaction among students.

Deconvolution and Estimation of Transfer Function Phase and Coefficients for NonGaussian Linear Processes.

Abstract: NonGaussian linear processes are considered. It is shown that the phase of the transfer function can be estimated under broad conditions. This is not true of Gaussian linear processes and in this sense Gaussian linear processes are atypical. The asymptotic behavior of a phase estimate is determined. The phase estimates make use of bispectral estimates. These ideas are applied to a problem of deconvolution which is effective even when the transfer function is not minimum phase. A number of computational illustrations are given.

Orientation selectivity in the cat's striate cortex is invariant with stimulus contrast

Abstract: Extracellular responses of single units in striate cortex of the cat were studied quantitatively. Sinusoidal gratings were used as stimuli and the variables of interest were orientation and contrast. Specifically, we wanted to determine if orientation tuning was dependent on contrast. Of 45 cells studied in detail, two basic types of contrast-response pattern were observed, but most patterns were intermediate between these extremes. In one type, responses increased approximately linearly with log contrast while in the second, saturation was found at low contrast levels. For all these cells, orientation tuning characteristics were independent of contrast. An additional observation, made from 14 cells, was that stimuli presented at non-optimal orientations can suppress responses to below the general maintained discharge levels. In eight of these cases, the inhibition was clearly contrast-dependent.

Recent Developments in Deterministic Sequencing and Scheduling: A Survey

Abstract: The theory of deterministic sequencing and scheduling has expanded rapidly during the past years. We survey the state of the art with respect to optimization and approximation algorithms and interpret these in terms of computational complexity theory. Special cases considered are single machine scheduling, identical, uniform and unrelated parallel machine scheduling, and open shop, flow shop and job shop scheduling. This paper is a revised version of the survey by Graham et al. (Ann. Discrete Math. 5(1979) 287–326) , with emphasis on recent developments.

The Effect of Treatment on Mortality in Mild Hypertension: Results of the Hypertension Detection and Follow-up Program

Abstract: In the Hypertension Detection and Follow-up Program, 7825 (71.5 per cent) of the 10,940 participants had diastolic blood pressures averaging between 90 and 104 mm Hg on entry into the study and were designated Stratum 1. Half were referred to their usual source of care in the community (the referred-care group), and half were treated intensively in special clinics (the stepped-care group). Five-year mortality in the Stratum 1 patients given stepped care was 20.3 per cent lower than in those given referred care (P less than 0.01). Particularly noteworthy was the beneficial effect of stepped-care treatment on persons with diastolic pressures of 90 to 104 mm Hg who had no evidence of end-organ damage and were not receiving antihypertensive medication when they entered the study. This subgroup had 28.6 per cent fewer deaths at five years among those treated with stepped care than among those treated with referred care (P less than 0.01). These findings support a recommendation that in patients with mild hypertension, treatment should be considered early, before damage to end organs occurs.

Chapter 15 Existence of competitive equilibrium

Abstract: Publisher Summary This chapter discusses that the mathematical model of a competitive economy conceived as an attempt to explain the state of equilibrium reached by a large number of small agents interacting through markets. Four distinct, but closely related, approaches to the existence problem are recognized. At first, proofs of existence of an economic equilibrium were uniformly obtained by application of a fixed-point theorem of the Brouwer type or Kakutani type or by analogous arguments. This approach, which has remained of central importance to the present, is the subject of the chapter. Second, in the past decade, efficient algorithms of a combinatorial nature for the computation of an approximate economic equilibrium were developed. Third, recently, the theory of the fixed-point index of a map and the degree theory of maps were used to establish the existence of an economic equilibrium, and finally a differential process was proposed whose generic convergence to an economic equilibrium provides an alternative constructive solution of the existence problem.

On the Security of Ping-Pong Protocols

Abstract: Consider the class of protocols, for two participants, in which the initiator applies a sequence of operators to a message M and sends it to the other participant; in each step, one of the participants applies a sequence of operators to the message received last, and sends it back. This “ping-pong” action continues several times, using sequences of operators as specified by the protocol. The set of operators may include public-key encryptions and decryptions.

Poverty and Physical Stature: Evidence on the Standard of Living of London Boys 1770–1870

Abstract: To many historians, and to most of their students, the question of the impact of the Industrial Revolution upon the poor of Britain has become confused, an arcane debate of ever greater statistical complexity. This is a pity, for “the most sustained single controversy in British economic history” still has, and should have, the capacity to excite and rouse the imagination, as it did for those who began, in the first half of the nineteenth century, the Condition of England debate (Mathias, 1975: vii; Taylor, 1975: xi). For Friedrich Engels, Edwin Chadwick, John Stuart Mill, or Lord Shaftesbury, and for many who as government inspectors or members of local statistical societies provided the evidence, the condition of the working classes was something tangible, to be seen in the streets of Manchester or London, demonstrated in the faces and bodies of the artisans and laborers who walked those streets and worked in the workshops and factories. The moral outrage felt by Engels, Chadwick, Shaftesbury, Barnardo, and many others in the nineteenth century came from the sight not only of squalid living conditions but of the malnourished bodies of the poor themselves.

On the Security of Ping-Pong Protocols.

Abstract: Consider the class of protocols, for two participants, in which the initiator applies a sequence of operators to a message M and sends it to the other participant; in each step, one of the participants applies a sequence of operators to the message received last, and sends it back. This “ping-pong” action continues several times, using sequences of operators as specified by the protocol. The set of operators may include public-key encryptions and decryptions.

Three phases of father involvement in pregnancy.

Abstract: A field study focusing on men's experiences of first-time expectant fatherhood, including intensive interviews with 20 expectant couples, short field interviews with 80 additional fathers, participant observation in prenatal classes and clinics, and content analysis of popular literature was conducted for the purpose of description and generation of substantive theory. Interview and field data were analyzed using constant comparative analytic technique for qualitative data. Evidence suggest a characteristic pattern of development of subjective emotional involvement in pregnancy among first-time expectant fathers. This pattern consists of three phases: an announcement phase, a moratorium and a focusing phase. The length of the second phase appears to be related to the man's perception of his own readiness for pregnancy. The father's speed of progression though these phases may affect later adjustment to fatherhood. Further testing and validation of these findings is indicated.

Regulating OP pesticide residues for farmworker protection

Abstract: The hazard to fieldworkers from the residues of organophosphate pesticides is a classic occupational health issue. Traditionally, the historical development of such issues has three phases or concerns, viz., recognition, evaluation, and control. In an ideal occupational health program, these three phases are cyclic and repetitive in that occupational health problems are typically first recognized by an unusual pattern of morbidity or mortality within an occupational group; the working environment is then evaluated via such samples and measurements as may be available and appropriate to identify and quantify the levels of exposure; control strategies and technologies are then brought into play to reduce these exposures; and in the ideal case, this process is repeated by follow-up biological and environmental monitoring to ensure that the controls are efficacious and sufficient. In the broad history of occupational diseases, these phases have typically spanned many years and rarely if ever have they progressed in a cohesive sequence or from a well-developed plan (Hunter 1978).

Surface-tension-driven breakup of viscoelastic liquid threads

Abstract: A linearized stability analysis is carried out for the breakup of small-diameter liquid filaments of dilute polymer solutions into droplets. Oldroyd's 8-constant model expressed in a corotational reference frame is used as the rheological equation of state. The crucial idea in this theory is the recognition that the liquid may be subject to an unrelaxed axial tension due to its prior history. If the tension is zero, the present analysis predicts that jets of shear-thinning liquids are less stable than comparable jets of Newtonian liquids; this is in agreement with previous analyses. However, when the axial tension is not zero, and provided the stress relaxation time constant is sufficiently large, the new theory predicts that the axial elastic tension can be a significant stabilizing influence. With reasonable values for the tension and stress relaxation time the theory explains the great stability observed for jets of some shear- thinning, dilute polymer solutions. The theory explains why drops produced from jets of such liquids are larger than drops from corresponding Newtonian liquids. The theory also appears capable of explaining the sudden appearance of irregularly spaced bulges on jets after long distances of t,ravel with little amplification of disturbances.

International Trade and Economic Growth

Abstract: The final chapter of the book is devoted to an extension of the two-sector model of economic growth to an open economy. We thus consider two countries, denoted as the “home” country (HC) and the “foreign” country (FC, or the rest of the world). The two goods will be, as before, consumption and investment.

Intraindividual variability in theophylline pharmacokinetics: Statistical verification in 39 of 60 healthy young adults

Abstract: After administering a single 300 mg dose of theophylline in oral solution to 12 healthy adults, the dose-normalized area under the plasma concentration-time curve was 97.2±20.1 % (mean±SD) of that after giving a 500 mg dose and statistically indistinguishable. Similarly, these areas multiplied by the individual's terminal disposition rate constant (β) were statistically indistinguishable between 300 and 500mg doses (99.1±10.3%), giving no evidence of dose-dependence for theophylline kinetics at the levels below 15 μg/ml observed in these individuals. After an intravenous dose, a shortlived distribution phase (t1/2α) is sometimes seen. An a phase, however, is hardly discernible in over 250 profiles arising from oral doses administered during five single dose bioavailability studies. Almost all such profiles appear to follow single-compartment model predictions. With precautions to avoid a potential a phase, a terminal log-linear slope can be fitted by least squares analysis with a relative standard error in the slope determination almost always less than 6%. Covariance analysis confirms statistically that 39 of the 60 participating individuals varied in their β on the different occasions each was required to take a dose during the course of a crossover bioavailability trial. In one study, even though each individual was observed on only two occasions, 9 out of 12 showed statistically identifiable variation in β. Fluctuations in β of 60% can be seen. Changes of 30% or greater are common and can occur within 3 or 4 days. Thus real, large, and potentially frequent changes in β of theophylline have been identified in a majority of normal subjects. These changes do not appear to be confined to either sex, to smokers or nonsmokers, or to heavier or lighter individuals. No chronological pattern has, as yet, been recognized in the intraindividual variability in β.

Hodge Cycles and Crystalline Cohomology

Abstract: This paper is a collection of musings about several questions related to crystalline cohomology that have plagued me for the past few years. It contains many more conjectures than proofs, and my justification for publishing is the hope that others will find the problems as intriguing as I did but perhaps have more success in solving them.

Liposome conjugates and diagnostic methods therewith

Abstract: A number of naturally occurring antibodies to human erythrocyte surface antigens are capable of combining with their specific antigens (for example, Rhesus factor), but are not capable of producing visible hemagglutination. Also, the sensitivity of many diagnostic methods, such as in human blood typing, depends upon cell agglutination. The present invention provides liposome-protein conjugates, especially useful for hemagglutination assays, having an enhanced agglutination capacity with respect to antibody from which the conjugates are derived.

When Misperception Matters

Abstract: This essay is an analysis of the implications of misperception—the inaccurate assessment by one actor of the other actor's preferences—in international relations. The author finds that misperception cannot affect the choice of an actor with a dominant strategy, although it can affect that actor's expectations as long as both actors are self-interested and seek to maximize their own payoffs. Misperception creates conflict only in a narrowly circumscribed range of situations, and even then the misperceived actor has no incentive to mask its true preferences. An actor who deceives does so in order to facilitate coordination through the other's misperception of its preferences, and thus to avoid conflict—not to create it. Three possible outcomes can occur when both actors misperceive, and in only one of the three does misperception cause conflict that would otherwise be avoidable. In a formal analysis of the limited set of situations that characterize international crises, misperception is found neither to create conflict nor to lead to the escalation of crisis into war.

Professionalization as a Policy Choice: British Special Education in Comparative Perspective

Abstract: Policies may be characterized in several distinct and competing ways: as best resolved by professional expertise, as fit for political determination, as properly treated in terms of legal rights, as appropriately subject to bureaucratic norms, or as sensibly left to market determination. The consequences of the choice among these frameworks is apparent in contrasting the British and American approaches to a particular policy issue, the education of handicapped children. That analysis reveals the utility of maintaining a policy scheme which builds in a tension among the competing frameworks.

The Teachable Pupil Survey: A Technique for Assessing Teachers' Perceptions of Pupil Attributes.

Abstract: The Teachable Pupil Survey was developed to measure teachers' perceptions of attributes that characterize teachable pupils. Teachers were asked to generate their perceptions of “idealized teachable” pupils and to identify “teachable” attributes from an adjective checklist. The responses were submitted to a multidimensional scaling technique, item reliability was established, and the 33 descriptors were organized into a Likert-type scale consisting of three major dimensions. The dimensions were labelled Cognitive-Motivational Behaviors, School-Appropriate Behaviors, and Personal-Social Behaviors.

Psychological Processes Induced by Illness, Injury, and Loss

Abstract: Most serious life events involve actual or potential losses: of a loved one, of material possessions, of health, or of hopes for the future. The ideal adjustment to loss is to accept it, replace that which is lost, and go on living. Between the first pangs of recognition of loss and adaptation to circumstances as they must be, there is an important, painful interval characterized by states of both intrusion and denial.

Studies on the cyclic AMP response to thyroid stimulating immunoglobulin (TSI) and thyrotropin (TSH) in human thyroid cell monolayers.

Abstract: Studies were conducted on the cultured human thyroid cell bioassay for thyroid stimulating immunoglobulin (TSI) and thyrotropin (TSH) In confirmation of the data of Kasagi, et al,15 incubation of human thyroid cells in Hank's balanced salt solution deficient in NaCl increased the sensitivity of the c-AMP response to bovine TSH by approximately one order of magnitude Half-maximal stimulation was attained at approximately 01 mU bTSH/ml The effect of NaCl in the medium was greater with stimulation by TSI greater than hTSH greater than bTSH In contract to incubations in NaCl(+)medium, with NaCl(-) medium most (70%-80%) of the c-AMP produced was released into the medium; this proportion remaining relatively constant over a wide range of bTSH and hTSH concentrations At TSI concentrations higher than 3mg/ml efflux of c-AMP into the medium was significantly diminished Stimulation by cholera toxin and prostaglandin E of thyroid cell c-AMP generation was not enhanced in NaCl(-) medium, in contrast to stimulation by TSH and TSI The presence of 10(-4)m cycloheximide in NaCl(+) medium enhanced the c-AMP response to physiological concentrations of TSH As with NaCl(-) medium, cycloheximide increased the sensitivity but not the maximum response of the c-AMP response to TSH However no additivity was observed with NaCl(-) medium and cycloheximide Human thyroid cells obtained from patients with Graves' disease are relatively insensitive to TSI stimulation In NaCl(-) medium, however, the sensitivity of these cells to TSI stimulation is sufficient to enable them to be utilized in the TSI assay The present state of the TSI assay is discussed

Preemptive Scheduling of. Precedence-Constrained Jobs on Parallel Machines

Abstract: Polynomial time-bounded algorithms are presented for solving three problems involving the preemptive scheduling of precedence-constrained jobs on parallel machines: the “intree problem”, the “two-machine problem with equal release dates”, and the “general two-machine problem”. These problems are preemptive counterparts of problems involving the nonpreemptive scheduling of unit-time jobs previously solved by Brucker, Garey and Johnson and by Garey and Johnson. The algorithms and proofs (and the running times of the algorithms) closely parallel those presented in their papers. These results improve on previous results in preemptive scheduling and also suggest a close relationship between preemptive scheduling problems and problems in nonpreemptive scheduling of unit-time jobs.