Showing papers by "University of North Carolina at Chapel Hill published in 1980"
TL;DR: In 1966, when an outpatient treatment program for autistic children and their families was initiated, there were two major sets of guidelines for diagnosing the children who were referred to the program, and the most promising at tempt to translate the Kanner definition into an empirical rating scale was the Rimland Checklist.
Abstract: In 1966, when we initiated an outpatient treatment program for autistic children and their families (Schopler & Reichler, 1971), there were two major sets of guidelines for diagnosing the children who were referred to our program. The first was Kanner ' s (1943) original definition of autism. At the start of our program the most promising at tempt to translate the Kanner definition into an empirical rating scale was the Rimland Checklist (1964), later revised into a second form (Rimland, 1971). This checklist was completed for all children evaluated in our program. From the very beginning, however, we had the clinical impression that very few of our children were autistic according to Kanner ' s criteria. The Creak (1964) criteria served as a second system of classification. Like Kanner 's , these were not entirely satisfactory from our perspective. Specifically, classification guidelines suitable for very young children were lacking. In response to the limitations of existing classification systems, we developed our own 15-scale rating system (Reichler & Schopler, 1971). These scales incorporated (a) Kanner ' s pr imary features, (b) other characteristics, noted by Creak, found
1,967 citations
TL;DR: In this article, the authors proposed an investment model for predicting satisfaction with and commitment to ongoing associations, where attraction to and satisfaction with a relationship is a function of a comparison of the relationship outcome value (both rewards and costs) to the individual's expectations.
1,678 citations
TL;DR: When tissue cells are cultured on very thin sheets of cross-linked silicone fluid, the traction forces the cells exert are made visible as elastic distortion and wrinkling of this substratum.
Abstract: When tissue cells are cultured on very thin sheets of cross-linked silicone fluid, the traction forces the cells exert are made visible as elastic distortion and wrinkling of this substratum. Around explants this pattern of wrinkling closely resembles the "center effects" long observed in plasma clots and traditionally attributed to dehydration shrinkage.
1,377 citations
992 citations
TL;DR: Drawings were made from Tanner's photographs illustrating five stages of development each for male genitalia, testicular size, male pubic hair, female breasts, and female pubichair, and Answers to questions concerning amount of underarm hair and general development yielded high correlations.
Abstract: Drawings were made from Tanner's photographs illustrating five stages of development each for male genitalia, testicular size, male pubic hair, female breasts, and female pubic hair. Forty-seven females and forty-eight males aged 12–16 years indicated on questionnaires which stage they were most like, and answered other questions related to their physical development. Afterwards they were examined by physicians who had not seen their answers. Pearson correlation coefficients were 0.6 or above for the physician's observations compared with the adolescents' answers for the drawings, with the exception of testicular size. Answers to questions concerning amount of underarm hair and general development also yielded high correlations.
932 citations
01 Jul 1980
TL;DR: A new algorithm for solving the hidden surface (or line) problem is described, to more rapidly generate realistic images of 3-D scenes composed of polygons, and the development of theoretical foundations in the area are presented.
Abstract: This paper describes a new algorithm for solving the hidden surface (or line) problem, to more rapidly generate realistic images of 3-D scenes composed of polygons, and presents the development of theoretical foundations in the area as well as additional related algorithms. As in many applications the environment to be displayed consists of polygons many of whose relative geometric relations are static, we attempt to capitalize on this by preprocessing the environment's database so as to decrease the run-time computations required to generate a scene. This preprocessing is based on generating a “binary space partitioning” tree whose in order traversal of visibility priority at run-time will produce a linear order, dependent upon the viewing position, on (parts of) the polygons, which can then be used to easily solve the hidden surface problem. In the application where the entire environment is static with only the viewing-position changing, as is common in simulation, the results presented will be sufficient to solve completely the hidden surface problem.
861 citations
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TL;DR: In this article, the authors apply microeconomic theory to illustrate the plausibility of a relationship between international trade and conflict, arguing that the mutual dependence established between two trading partners (dyads) is sufficient to raise the costs of conflict.
Abstract: This article applies microeconomic theory to illustrate the plausibility of a relationship between international trade and conflict. It is argued that the mutual dependence established between two trading partners (dyads) is sufficient to raise the costs of conflict, there-by diminishing levels of dyadic dispute. This hypothesis of a negative relationship between conflict and trade is tested using a ten-year thirty-country cross section merged from four separate data sources. It is found that ceteris paribus countries with the greatest levels of economic trade engage in the least amounts of hostility. In fact, a doubling of trade on average leads to a 20% diminution of belligerence. This relationship appears robust, holding even more strongly when statistical adjustments are made for causality.
632 citations
TL;DR: In this paper, two general classes of explanations for such non-Ohmic effects are presented: thermal and electronic. But, as discussed in Section 2.1, the use of the terminology electrothermal encompasses predominantly thermal and predominantly electronic processes as well as all intermediate cases, and therefore should not prejudice the casual observer into concluding that both effects are necessarily important.
Abstract: The application of sufficiently high electric fields to any material eventually results in deviations from linearity in the observed current-voltage I(V) characteristic. There are two general classes of explanations for such non-Ohmic effects— thermal and electronic. Thermal effects arise because the electrons accelerated by the field always emit phonons in an attempt to return to equilibrium. Electronic effects are due to changes in the response of the charged carriers to high applied fields. In general, both effects must be considered in any quantitative analysis, and the two can produce a coupled response ofter called “electrothermal.” The use of the terminology electrothermal encompasses predominantly thermal and predominantly electronic processes as well as all intermediate cases, and therefore should not prejudice the casual observer into concluding that both effects are necessarily important. In a discussion of the physical mechanism in a particular sample, the major parameters controlling its operation must be identified and separated out from the less significant features.
604 citations
TL;DR: Compared with women not taking exogenous sex hormones, women taking hormones have higher total plasma triglyceride values at all ages from 20–59 years, and VLDL cholesterol values are higher in women on hormones compared with nonusers of hormones younger than 55 years.
Abstract: Total plasma lipid and lipoprotein-cholesterol distributions of 4756 white men and women between the ages of 20-59 are presented Measurements were obtained during the visit-2 survey of the (LRC) Lipid Research Clinics Program Prevalence Study and correspond to a 15% random sample of 35748 white adults screened during the LRC visit-1 survey Standardized examinations were carried out by 10 North American clinics using a common protocol on diverse target populations chosen to include a range of sociodemographic characteristics Age-specific means medians and selected percentiles are given by sex with stratification on exogenous sex hormone use in women Plasma lipid and lipoprotein concentrations in men and women vary with age Differences in lipid and lipoprotein levels between the study populations are also present and manifest themselves as parallel trends of age-related changes in the 10 populations examined Higher total cholesterol values in men as compared with women appear between the ages of 20-50 and higher LDL cholesterol between ages 20-55 VLDL cholesterol levels are similar in both sexes at ages 20 and 59 years but higher in men than in women in all intermediate age groups HDL cholesterol is higher in women than in men throughout the age range under consideration Women taking sex hormones have higher total cholesterol than women not on hormones between ages 20-50 and higher LDL cholesterol between 20-40 From the 3rd age decade onward HDL cholesterol levels are progressively higher in women taking hormones than in women who are not Compared with women not taking exogenous sex hormones women taking hormones have higher total plasma triglyceride values at all ages from 20-59 VLDL cholesterol values are higher in women on hormones compared with nonusers of hormones younger than 55 years (Authors modified)
567 citations
TL;DR: P predictive equations were developed to estimate dry weight from body length measurements for forty-three taxa of aquatic insects and indicated that the relationship between biomass and body size was best expressed by a power equation, Y =aXb, rather than by linear or exponential equations.
Abstract: SUMMARY. Predictive equations were developed to estimate dry weight from body length measurements for forty-three taxa of aquatic insects. The inter-relationships between dry weight, body length and head capsule width of individuals grouped according to the eight major orders of aquatic insects were also examined. Regression analysis indicated that the relationship between biomass and body size was best expressed by a power equation, Y =aXb, rather than by linear or exponential equations. Changes in body length versus head capsule width were best expressed by linear equations, with three distinct relationships being observed. Body length estimated biomass better than head capsule width. Populations often species of insects collected from two different rivers generally did not differ significantly in their dry weight to body length relationships.
503 citations
TL;DR: In this article, the authors consider two methods of defining a regression analog to a trimmed mean: the first was suggested by Koenker and Bassett and uses their concept of regression quantiles; the second method uses residuals from a preliminary estimator.
Abstract: We consider two methods of defining a regression analog to a trimmed mean. The first was suggested by Koenker and Bassett and uses their concept of regression quantiles. Its asymptotic behavior is completely analogous to that of a trimmed mean. The second method uses residuals from a preliminary estimator. Its asymptotic behavior depends heavily on the preliminary estimate; it behaves, in general, quite differently than the estimator proposed by Koenker and Bassett, and it can be inefficient at the normal model even if the percentage of trimming is small. However, if the preliminary estimator is the average of the two regression quantiles used with Koenker and Bassett's estimator, then the first and second methods are asymptotically equivalent for symmetric error distributions.
TL;DR: The finding that multiple tissues synthesize somatomedin-C raises the possibility that the primary biological actions of this hormone are exerted locally at its sites of origin.
TL;DR: In this paper, the synthesis of complexes derived from the planar tridentate ligand 2,2',2''-terpyridine (trpy) of the type trpyRu/sup II/(L)Cl/sub 2/ where L = PPh/sub 3/, P(p-C/sub 6/H/sub 4/Me)/sub 3), or pyridine are described.
Abstract: The syntheses of complexes derived from the planar, tridentate ligand 2,2',2''-terpyridine (trpy) of the type (trpy)Ru/sup II/(L)Cl/sub 2/ where L = PPh/sub 3/, P(p-C/sub 6/H/sub 4/Me)/sub 3/, or pyridine are described. Some rather striking differences in the properties of the cis and trans-isomers of the phosphine derivatives are reported. (BLM).
TL;DR: The presence of a cellulosic microfibril system in Zea mays root segments is confirmed by degradation experiments with Trichoderma cellulase and it is proposed that intramembrane rosettes function in association with terminal complexes to synthesizemicrofibrils.
Abstract: Freeze-fracture of rapidly frozen, untreated plant cells reveals terminal complexes on E-fracture faces and intramembrane particle rosettes on P-fracture faces. Terminal complexes and rosettes are associated with the ends of individual microfibril impressions on the plasma membrane. In addition, terminal complexes and rosettes are associated with the impressions of new orientations of microfibrils. These structures are sparse within pit fields where few microfibril impressions are observed, but are abundant over adjacent impressions of microfibrils. It is proposed that intramembrane rosettes function in association with terminal complexes to synthesize microfibrils. The presence of a cellulosic microfibril system in Zea mays root segments is confirmed by degradation experiments with Trichoderma cellulase.
TL;DR: In this paper, the authors study nonsingular vacuum Cauchy hypersurfaces with two isometric asymptotically flat ends connected by an Einstein-Rosen-type bridge and show that the complete initial data transform invariantly under inversion through a minimal two-surface that represents the "throat" of the geometry.
Abstract: As a first step in constructing initial data for dynamic black holes and general black-hole collisions, we study nonsingular vacuum Cauchy hypersurfaces with two isometric asymptotically flat ends connected by an Einstein-Rosen-type bridge. These hypersurfaces are assumed to be conformally flat and maximally embedded in space-time but are neither spherically symmetric nor time symmetric. Three of the four constraints are solved explicitly for suitable extrinsic curvature tensors that possess linear momentum and/or intrinsic angular momentum. The complete initial data are shown to transform invariantly, modulo the sign of the extrinsic curvature tensor, under inversion through a minimal two-surface that represents the ''throat'' of the geometry. These and other properties show that the data represent a particular epoch in the history of a dynamic black hole. We describe the relation of our data to that of the Schwarzschild and Kerr black holes. Finally, we discuss the generalization to encounters of two or more black holes.
TL;DR: In this article, the authors measured in situ with benthic chambers averages 49 and 163 μmol · m −2 · hr −1 during November-May and June-October respectively.
TL;DR: The delay in the serum SM-C response to the administration of hGH suggests that SM is not stored in a readily releasable form and that the effect of GH on SM production may be through the stimulation of de novo synthesis.
Abstract: The induction of somatomedin C (SM-C) was evaluated in 30 hypopituitary patients and in normal subjects using a sensitive, specific RIA for SM-C. Two hypopituitary patients each received an iv bolus of 0.1 U human GH (hGH)⁄kg BW, followed by continuous infusion of 0.01 U hGH⁄kg-h for 12 h. The earliest rise in SM-C was detectable between 6-8 h. In response to the im administration of hGH, hypopituitary patients demonstrated a delay of 8 h before the rise in SM-C, a peak response between 16-28 h, and a fall nearly to basal levels by 48 h. The delay in the serum SM-C response to the administration of hGH suggests that SM is not stored in a readily releasable form and that the effect of GH on SM production may be through the stimulation of de novo synthesis. Graded doses of hGH in a sequence of 0.1, 0.2, 0.4, and 0.8 U/kg (im) elicited a stairstep pattern of SM-C response. When the sequence of administration of these doses was altered, however, it was apparent that the magnitude of the SM-C response was dete...
TL;DR: In this paper, a variant of the economic model of crime was developed using information on the post-release activities of a sample of men released from the North Carolina prison system, and both the expected certainty and severity of punishment were found to deter criminal activity in a number of instances and a 1 percent increase in certainty is generally found to have a greater effect than a similar increase in severity.
Abstract: The paper develops a variant of the economic model of crime. The model developed is estimated using information on the post-release activities of a sample of men released from the North Carolina prison system. Both the expected certainty and severity of punishment are found to deter criminal activity in a number of instances and a 1 percent increase in certainty is generally found to have a greater effect than a similar increase in severity. Certainty of punishment is found to have a greater effect for relatively minor offenders and severity for persons offenders. While higher legal wages are found to deter, their effect is quite weak.
TL;DR: Infection of the gastrointestinal tract may cause diarrhea by two pathogenic mechanisms that have been well described in laboratory animals and man: direct invasion of the intestin...
Abstract: ESCHERICHIA COLI infection of the gastrointestinal tract may cause diarrhea by two pathogenic mechanisms that have been well described in laboratory animals and man: direct invasion of the intestin...
TL;DR: In this article, a student of international systems uses events singularly or in the aggregate to study foreign policy outputs and inputs, which are useful information which allow a student to use events to analyze foreign policy output and inputs.
Abstract: As students of politics and political science, we should and we do care about the events which lead to war, instability, and international tension as well as about events which lead to equitable interdependence, integration, peace, improvement of quality of life, reduction of colonialism, and so on. Because we care about these matters, we try to advance procedures and theories about systematizing our observations and improving our skills of analysis. Recent developments in international relations have tended to (a) emphasize the exploration of more specific problems and testing of hypotheses with quantified data and (b) deemphasized the search for general theories of internation behavior. This trend appears to be undergoing slight modification for many reasons. Events contain useful information which permit a student of foreign policy to use events singularly or in the aggregate to study foreign policy outputs and inputs. A student of international systems uses events singularly or in the aggregate to stu...
TL;DR: Analysis is underway to identify approaches to infection control that are most effective for the least cost to hospitals and to point out additional specific questions to be answered by future research.
Abstract: With the emergence of nosocomial infections as a serious problem among US hospitals, the Center for Disease Control undertook in 1974 a nationwide study to evaluate approaches to infection control. The three-phased project, now known as the Study on the Efficacy of Nosocomial Infection Control, or SENIC Project, was designed with three primary objectives: 1) to determine whether (and, if so, to what degree) the implementation of infection surveillance and control programs (ISCPs) has lowered the rate ofnosocomi al infection, 2) to describe the current status of ISCPs and infection rates, and 3) to demonstrate the relationships among characteristics of hospitals and patients, components of ISCPs, and changes in the infection rate. With data collection completed in a nationally representative sample of hospitals, analysis is underway to identify approaches to infection control that are most effective for the least cost to hospitals and to point out additional specific questions to be answered by future research.
TL;DR: For over 80 years succession theory has played a central role in plant ecology, providing both a predictive tool and organizational scheme as discussed by the authors, drawing on this long history of research and observation, Margalef (1968), Odum (1969), Whittaker (1975) and others have identified general trends in community development.
Abstract: For over 80 years succession theory has played a central role in plant ecology, providing both a predictive tool and organizational scheme. Drawing on this long history of research and observation, Margalef (1968), Odum (1969), Whittaker (1975) and others have identified general trends in community development. Their synthetic treatments have helped focus the efforts of subsequent workers examining the empirical and experimental basis of succession theory (e.g. Connell & Slatyer 1977, Drury & Nisbet 1973, Egler 1975, Horn 1974, Pickett 1976, van Hulst 1978). This more recent work suggests that the classical succession paradigm is seriously flawed and that many long held concepts need to be reexamined.
TL;DR: Use of Calcofluor has made it possible to separate the processes of polymerization and crystallization leading to the biogenesis of cellulose microfibrils, and has suggested that crystallization occurs by a cell-directed process.
Abstract: The fluorescent brightener, Calcofluor White ST, prevents the in vivo assembly of crystalline cellulose microfibrils and ribbons by Acetobacter xylinum. In the presence of more than 0.01 percent Calcofluor, Acetobacter continues to synthesize high-molecular-weight beta-1,4 glucans. X-ray crystallography shows that the altered product exhibits no detectable crystallinity in the wet state, but upon drying it changes into crystalline cellulose I. Calcofluor alters cellulose crystallization by hydrogen bonding with glucan chains. Synthesis of this altered product is reversible and can be monitored with fluorescence and electron microscopy. Use of Calcofluor has made it possible to separate the processes of polymerization and crystallization leading to the biogenesis of cellulose microfibrils, and has suggested that crystallization occurs by a cell-directed. self-assembly process in Acetobacter xylinum.
TL;DR: In this article, the authors consider the case where the non-positive component of the disturbance represents the shortfall of actual output from the frontier, while the frontier contains the normal component of disturbance, and is therefore stochastic.
Journal Article•
TL;DR: The data support the Ainslie-Rachlin model and extend it to human choice behavior and show that some humans committed themselves to the large reward when commitment could be made some time before presentation of the reward alternatives.
TL;DR: A new ponto-medullary neural mechanism which is uniquely activated by peripheral chemoreceptor afferent input is demonstrated; once activated, this mechanism sustains respiration at an increased level for a long period of time.
TL;DR: It is concluded that the long-lasting increase of respiratory activity following stimulation of carotid body afferents is due to activation of an endogenous central serotoninergic mechanism which facilitates respiration.
TL;DR: The results are taken to indicate that phosphorylation modifies MAPs so that they have a reduced ability to form an assembly-competent complex with tubulin.
Abstract: 32P labeling of microtubular protein by endogenous protein kinase activity is shown to result from a net increase in protein-bound phosphate and is not the result of a phosphate exchange reaction between ATP and phosphoprotein. Protein phosphorylation is maximal in the presence of 0.5 mM Mg2+ and 0.25 mM ATP, resulting in approximately 2.8 nmol of phosphate/mg of protein. However, phosphorylation can be increased two-to threefold by cAMP. The protein substrates for phosphorylation either the absence or presence of cAMP are the microtubule-associated proteins which copurify with tubulin and promote microtubule assembly. Phosphorylation of microtubule-associated proteins inhibits both the rate and extent of microtubule assembly when the protein is exposed to conditions which result in dissociation of rings. These results are taken to indicate that phosphorylation modifies MAPs so that they have a reduced ability to form an assembly-competent complex with tubulin.