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Showing papers by "University of Pittsburgh published in 1977"


Journal ArticleDOI
TL;DR: In this article, the grain-size dependence of parameters with coercive force as high as 2,000 Oe in x = 0.6 titanomagnetite was found.

2,657 citations


Book ChapterDOI
01 Jan 1977
TL;DR: It is argued that a sophisticated question-answering machine that has the capability of making inferences from its data base should employ a certain four-valued logic, the motivating consideration being that minor inconsistencies in its data should not be allowed to lead to irrelevant conclusions.
Abstract: It is argued that a sophisticated question-answering machine that has the capability of making inferences from its data base should employ a certain four-valued logic, the motivating consideration being that minor inconsistencies in its data should not be allowed to lead (as in classical logic) to irrelevant conclusions. The actual form of the four-valued logic is ‘deduced’ from an interplay of this motivating consideration with certain ideas of Dana Scott concerning ‘approximation lattices.’

1,477 citations


Journal ArticleDOI
TL;DR: In this paper, a self-control model with the addition of attributional considerations is proposed as a heuristic model for the analysis of the phenomena of depression, and evidence for the model is cited.

578 citations


Journal ArticleDOI
TL;DR: In this article, a measure of five interpersonal conflict-handling modes (competing, collaborating, compromising, avoiding, and accommodating) is proposed to control the social desirability response bias.
Abstract: This paper describes the rationale and development of a new measure of five interpersonal conflict-handling modes (competing, collaborating, compromising, avoiding, and accommodating), which attempts to control for the social desirability response bias. The instrument is entitled: "Management-of-Differences Exercise," or the MODE instrument. The results of this study indicate that the new instrument significantly reduces the social desirability bias for overall population tendencies in comparison to three other conflict behavior instruments, although all four instruments may still be susceptible to some individual tendencies in this response bias. This study also investigated other aspects of substantive validity and structural validity. Lastly, this paper presented emerging evidence on external validity, which, while encouraging, suggests the need for continuing research efforts to investigate this aspect of validity for the new MODE instrument.

526 citations


Journal ArticleDOI
18 Feb 1977-Science
TL;DR: The proposed hypothesis is that the deleterious behavioral effects of decreased DA activity may be counterbalanced by a similar decrease occurring in NE activity, such compensation being most likely to occur under conditions of stress.
Abstract: The proposed hypothesis is directed toward explaining a number of disparate findings in terms of a stress-related interaction between the NE- and DA-containing systems in the brain. The deleterious behavioral effects of decreased DA activity, for example, may be counterbalanced by a similar decrease occurring in NE activity, such compensation being most likely to occur under conditions of stress. This hypothesis may have application to the understanding of neurological and mental disorders such as Parkinson's disease and schizophrenia.

407 citations


Journal ArticleDOI
TL;DR: A comparison of recent leukemic patients with and without candidiasis revealed that only positive blood and urine cultures had predictive diagnostic value, but these cultures were frequently negative.
Abstract: Thirty-nine patients who had disseminated candidiasis were studied at autopsy between 1963 and June 1975. The number of cases at autopsy increased from 1.1 to 6.8 cases per year during the last four and a half years, due primarily to the occurrence of candidiasis in patients with acute leukemia. The recent high incidence of disseminated candidiasis complicating acute leukemia correlated with the use of modern chemotherapy, which results in prolonged granulocytopenia during the induction of remission. All recent leukemic patients had gastrointestinal candidiasis, and many had hepatic (75%) and splenic (94%) involvement by unusually large macroscopic lesions. Candida stellatoidea (eight cases), Candida albicans (six cases), and Candida tropicalis (six cases) were the most frequently identified species. Clinical and laboratory detection of disseminated candidiasis was often impossible. A comparison of recent leukemic patients with and without candidiasis revealed that only positive blood (7/16 vs . 1/17) and urine (8/16 vs . 3/17) cultures had predictive diagnostic value, but these cultures were frequently negative. The best approach toward reducing the incidence of disseminated candidiasis in acute leukemia appears to be prevention of gastrointestinal infection.

282 citations


Journal ArticleDOI
TL;DR: In six neonates at risk for CAH the diagnosis was made utilizing the microfilter paper method, and the concentrations of 17α-OH-P were highly elevated in both filter paper eluates of whole blood and simultaneously obtained plasma concentration in affected infants.
Abstract: A new micromethod for measuring a steroid in blood collected on filter paper has been developed. The method is easy and rapid and has the specificity, accuracy and precision of RIA in whole plasma. Less than 20 μl of blood is required, and, therefore, samples may be obtained with heel prick. This method has been applied to the determination of 17α-hydroxyprogesterone (17α-OH-P) for screening patients with congenital adrenal hyperplasia (CAH) due to 21-hydroxylase deficiency. There was excellent correlation (r = .94) between the values of 17α-OH-P obtained by microfilter paper method and those from plasma samples of cord (40 ± 13 ng/ml) and neonatal blood (<3.6 ng/ml) in normal infants. In six neonates at risk for CAH the diagnosis was made utilizing the microfilter paper method. 17α-OH-P concentrations were highly elevated in both filter paper eluates of whole blood (67–360 ng/ml of plasma) and simultaneously obtained plasma concentration (74–395 ng/ml) in affected infants. The concentrations of 17α-OH-P ...

266 citations


Proceedings Article
22 Aug 1977
TL;DR: Experience with the INTERNIST system suggests that many aspects of the search process could be significantly enhanced if it were possible to attend to the various component problems and their interrelationships simultaneously.
Abstract: The INTERNIST system, which is a computer-based diagnostic problem solver having Internal Medicine as i ts domain of discourse, employs a novel attention focusing heuristic in order to deal sequentially with the component parts of a complex clinical problem. The strategy of sequential problem formation and solution has proved to be effective in sorting out the complexities and rendering a correct diagnosis in the great majority of clinical cases tested. Experience with the system suggests, however, that many aspects of the search process could be significantly enhanced if it were possible to attend to the various component problems and their interrelationships simultaneously. Recent work on a successor system has been directed towards the development of strategies for the synthesis and analysis of composite hypotheses, which may be expected to yield more rapid convergence to the correct conclusion in many cases, and in at least some cases to prevent missed diagnoses.

243 citations


Journal ArticleDOI
TL;DR: The effects of social-skills training consisting of instructions, feedback, behavior rehearsal, and modelling were examined in four unassertive children and overall assertiveness in all subjects increased from baseline assessment to the conclusion of treatment and into followup.
Abstract: The effects of social-skills training consisting of instructions, feedback, behavior rehearsal, and modelling were examined in a multiple-baseline analysis in four unassertive children. The treatment was effective in that the behaviors selected for modification changed markedly. The effects of treatment generalized from trained to untrained items (interpersonal situations requiring assertive responding) and gains were maintained at the two-and four-week followup probe sessions. In addition, overall assertiveness in all subjects increased from baseline assessment to the conclusion of treatment and into followup.

233 citations


Journal ArticleDOI
TL;DR: In this article, a tabulation of theoretical predictions for the electron bremsstrahlung energy spectrum from neutral atoms as a function of atomic number Z, incident electron kinetic energy T 1, and fraction of energy radiated k T 1.

203 citations


Journal ArticleDOI
TL;DR: The results contrast with previous reports in which behavioral sensitivity to apomorphine was increased 2- to 7-fold following partial degeneration of central dopamine neurons of following the chronic adminstration of dopamine synthesis inhibitors of receptor blocking agents.

Journal ArticleDOI
TL;DR: Data are consistent with earlier studies in women ingesting oral contraceptives and provide support for the thesis that the progressive increase in plasma progesterone alone or in combination with estrogens that occurs during pregnancy is responsible for the reduction of lower esophageal sphincter pressure which allows esophagal reflux to occur with the resultant development of symptomatic heartburn.

Journal ArticleDOI
TL;DR: The possibility that the so-called physical attractiveness stereotype may contain a kernel of truth was investigated in a study where college students interacted with opposite sex partners whom they could not see as discussed by the authors.

Journal ArticleDOI
TL;DR: Evidence is presented to support the conclusion that the metabolite in question is NH3, and the biological and biochemical performances of autoinduced slugs and of those induced by the metabolismite preparations or by ammonium carbonate solutions were indistinguishable.

Journal ArticleDOI
01 Jun 1977-Cancer
TL;DR: Findings from the second protocol confirm those previously reported indicating that L‐PAM lengthens the disease free interval following mastectomy and lend support to the thesis that since breast cancer is an eponym to describe a heterogeneous group of tumors residing in a heterogenous group of women, it is unlikely that uniformly qualitative and quantitative systemic regimens of therapy will be required for every patient.
Abstract: In 1972, a prospective, randomized, multi-institutional, cooperative clinical trial was begun to evaluate the efficacy of prolonged 1-phenylalanine mustard (L-PAM) administration following operation in lengthening the disease free interval of patients with primary breast cancer That protocol using a single agent was the first of a series directed toward evaluating successively more complex chemotherapeutic regimens in an attempt to define subsets of patients which might be responsive to less therapy than others When it was observed that L-PAM prolonged the disease free interval, particularly of premenopausal patients, findings were reported and a new evaluation comparing L-PAM with L-PAM plus 5-fluorouracil (5-FU) was begun Upon completion of patient accrual in that protocol, an additional trial comparing L-PAM and 5-FU with L-PAM, 5-FU and Methotrexate was implemented The present report updates findings from the initial study and presents those from the second It compares results across the first two protocols as well as between groups within a protocol While insufficient time has elapsed for determining the ultimate worth of the modalities employed, findings from the second protocol confirm those previously reported indicating that L-PAM lengthens the disease free interval following mastectomy The combination of L-PAM with 5-FU resulted in a reduction of treatment failure at 12 months which is as good or better than that observed with L-PAM in the first protocol lending further credibility to the earlier findings While at the end of the first year following mastectomy there was alomst a 50% reduction in treatment failures in patients aged 50 or over (post-menopausal), by 18 months the reduction was 23% and at two years, based on small numbers of patients, only 5% Examination of results from the first protocol (placebo vs L-PAM) after two years reveals a most highly significant effect of L-PAM in pre-menopausal women with one to three positive nodes There is an 89% reduction of treatment failures A similar but less striking effect is noted for those under 50 with ≥four positive nodes In older patients in both nodal categories, the early observed effect for L-PAM has decreased with time Inter-protocol comparisons relative to survival are premature At two years survival in L-PAM patients is 36% greater than in those receiving placebo It is somewhat better in every subgroup for those receiving L-PAM Information relative to the effect of these agents on patient toxicity and loco-regional treatment failures is presented All of the findings stress the urgency for obtaining results on subsets of patients rather than on a population as a whole and they lend support to the thesis that since breast cancer is an eponym to describe a heterogeneous group of tumors residing in a heterogeneous group of women, it is unlikely that uniformly qualitative and quantitative systemic regimens of therapy will be required for every patient

Journal ArticleDOI
TL;DR: In this paper, the phase shift due to gravitation and rotation in the quantum interference of two coherent beams is obtained relativistically and compared with the recent experiment of Colella, Overhauser, and Werner.
Abstract: The phase shift due to gravitation and rotation in the quantum interference of two coherent beams is obtained relativistically and compared with the recent experiment of Colella, Overhauser, and Werner. A general expression relating the quantum phase shift to the transverse acceleration of a classical particle in the plane of interference for an arbitrary interaction with any external field is given. This can serve as a correspondence principle between quantum physics and classical physics. The phase shift due to the coupling of spin to curvature of space-time is deduced and written explicitly for the special case of a Schwarzschild field. The last result implies that a massless spinning particle can have at most two helicity states and its world line in a gravitational field is a null geodesic. Finally, new experiments are proposed to test the effect of rotation on quantum interference and to obtain direct evidence of the equivalence principle in quantum mechanics.

Journal ArticleDOI
TL;DR: A quantitative analysis of VMN damage revealed a relatively low, but statistically significant positive correlation between degree ofVMN damage and lordosis deficits.

Journal ArticleDOI
TL;DR: The coronal level of the paraventricular nucleus was revealed as the rostral focus of a longitudinal satiety neurocircuitry in hyperphagia, obesity, and excessive linear growth, but not hyperdipsia.

Journal ArticleDOI
TL;DR: It was concluded that the current TLV of 1 ppm for chlorine is the upper acceptable limit, and that the establishedTLV of 5 ppm for hydrogen chloride lies at the lower limit of the predicted range.
Abstract: Groups of male Swiss-Webster mice were exposed to concentrations of chlorine varying from 0.7 to 38.4 ppm and to concentrations of hydrogen chloride varying from 40 to 943 ppm. The total exposure time to both gases was 10 minutes. Dose-response curves were plotted for both chlorine and hydrogen chloride, using the percentage decrease in respiratory rate during each exposure as the response reflecting sensory irritation of the upper respiratory tract. The results showed chlorine to be 33.0 times more irritating than hydrogen chloride, with 95% confidence limits of 18.6 and 57.1. Guidelines for obtaining a range of acceptable threshold limit values (TLV) based on sensory irritation of the upper respiratory tract are discussed. It was concluded that the current TLV of 1 ppm for chlorine is the upper acceptable limit, and that the established TLV of 5 ppm for hydrogen chloride lies at the lower limit of the predicted range. The mechanism of chlorine's and hydrogen chloride's sensory irritation may be explained by their reaction with various functional groups in the membranes of the trigeminal nerve endings lining the nasal mucosa.

Journal ArticleDOI
TL;DR: It is suggested that an increase in intracellular Ca concentration stimulates colonic electrolyte secretion and that the secretory response to cAMP may be due, at least in part, to a release of Ca from intrACEllular stores.
Abstract: Addition of Ca ionophore, A23187, to the solution bathing the mucosal surface of descending rabbit colon resulted in a reversal of active Cl absorption to active Cl secretion, a twofold increase in short-circuit current and a 40% increase in tissue conductance without affecting the rate of active Na absorption. These alterations in electrolyte transport are quantitatively similar to those previously observed in response to cyclic 3′,5′-AMP (cAMP) (R.A. Frizzell, M.J. Koch & S.G. Schultz,J. Membrane Biol. 27:297, 1976). When medium Ca concentration was reduced to 10−6 m, the secretory response to A23187 was abolished but the response to cAMP was unaffected. The ionophore did not influence the cAMP levels of colonic mucosa. Addition of cyclic AMP to colonic strips preloaded with45Ca elicited a reversible increase in Ca efflux from the tissue. These results suggest that an increase in intracellular Ca concentration stimulates colonic electrolyte secretion and that the secretory response to cAMP may be due, at least in part, to a release of Ca from intracellular stores.

Journal ArticleDOI
TL;DR: This article found that five-year-olds recall fewer items than adults in memory-span tasks involving both familiar and unfamiliar faces, even though the use of rehearsal and recoding strategies was minimized for adults.

Journal ArticleDOI
01 Apr 1977-Science
TL;DR: While the sympathetic response during marked hypoglycemia may have been initiated by alterations in cerebal metabolism, the feeding response evidently was not, and a decrease in the utilization of glucose per se does not appear to be the critical stimulus in either case.
Abstract: Intravenous infusions of manose or B-hydroxybutyrate, metabolic fuels which can be oxidized by brain, abolished adrenal discharge of epinephrine in rats during insulin-induced hypoglycemia, whereas infusion of fructose, a sugar which does not cross the blood-brain barrier, did not. In contrast, increased feeding behavior during hypoglycemia was prevented both by the sugars and by B-hydroxybutyrate. Thus, while the sympathetic response during marked hypoglycemia may have been initiated by alterations in cerebal metabolism, the feeding response evidently was not, and a decrease in the utilization of glucose per se does not appear to be the critical stimulus in either case.

Journal ArticleDOI
TL;DR: It is apparent that depending on the factor of antiviral resistance compromised after transplantation, not only are the infections caused by characteristic agents, but the nature of clinical manifestations, if present, are also typical.
Abstract: Viral infections particularly with the herpesvirus group (eytomegalovirus, herpes simplex, varicella-zoster and EB viruses), pap0vavirus, hepatitis-B virus and adenoviruses are more common after organ transplantation. A number of factors which singly or in combination reduce the antiviral resistance of the host are active following this procedure. These will be pointed out an analyzed. Nevertheless, one is impressed tha t not all virus infections are increased following transplantation. A number of common ones are notable by their absence. Infections with rhinoviruses, myxoviruses, paramyxoviruses, rubella, enteroviruses and arboviruses do not appear to be increased, although evidence is incomplete (4). A virus may be transmit ted from the outside and infect de nero (primary infection), or it may already be in the patient and is activated (secondary infection). This important distinction is not always made or Studied. An a t tempt will be made here in each virus infection to distinguish between these two modes of infection. By and targe, reactivation type infections appear to occur more readily but not exclusively after transplantation. I t is apparent that depending on the factor of antiviral resistance compromised after transplantation, not only are the infections caused by characteristic agents, but the nature of clinical manifestations, if present, are also typical.

Journal ArticleDOI
TL;DR: In this paper, the authors established novel stability criteria for multidimensional digital and analog filters with rational transfer functions, which generalize and simplify the stability test for two-dimensional digital filters developed by Huang [4] and significantly simplify the corresponding tests of stability of arbitrary multi-dimensional filters established by Anderson and Jury [6].
Abstract: Novel stability criteria are established, for multidimensional digital and analog filters with rational transfer functions. The criteria generalize and simplify the stability test for two-dimensional digital filters developed by Huang [4], and significantly simplify the corresponding tests of stability of arbitrary multidimensional filters established by Anderson and Jury [6].

Journal ArticleDOI
TL;DR: Seven of 10 patients with visceral larva migrans (VLM) had serum precipitating antibodies specific for larval antigens of Toxocara canis as determined by double diffusion in agar, and additional studies of those patients indicated that infection with ToxOCara can be distinguished serologically from ascariasis, filariasis and trichinellosis.
Abstract: Seven of 10 patients with visceral larva migrans (VLM) had serum precipitating antibodies specific for larval antigens of Toxocara canis as determined by double diffusion in agar. Such antibodies were absent in 114 normal adults and 25 patients with collagen disease. Precipitation of ascarid components by C-reactive protein resulted in false-positive reactions, but this precipitation was readily prevented by appropriate absorption of sera before testing. A more sensitive assay, the enzyme-linked immunosorbent assay, revealed high titers of antibodies to larvae of Toxocara in all patients with VLM; the log2 titer ranged from 9 to 14. Five of eight household relatives of these patients and four children who had had VLM two to four years before testing had titers of 6-12. Of the 114 normal adults, 105 had titers of 0-2; nine had titers of 3-8. Of the 25 patients with collagen disease, 23 had titers of 0, and two had titers of 4 and 6, respectively. Additional studies of those patients indicated that infection with Toxocara can be distinguished serologically from ascariasis, filariasis, and trichinellosis.

Journal ArticleDOI
TL;DR: An implicit finite difference technique employing orthogonal curvilinear co-ordinates is used to solve the Navier-Stokes equations for peristaltic flows in which both the wall-wave curvature and the Reynolds number are finite as discussed by the authors.
Abstract: An implicit finite-difference technique employing orthogonal curvilinear co-ordinates is used to solve the Navier–Stokes equations for peristaltic flows in which both the wall-wave curvature and the Reynolds number are finite (§2). The numerical solutions agree closely with experimental flow visualizations. The kinematic characteristics of both extensible and inextensible walls (§3) are found to have a distinct influence on the flow processes only near the wall. Without vorticity, peristaltic flow observed from a reference frame moving with the wave will be equivalent to steady potential flow through a stationary wavy channel of similar geometry (§4). Solutions for steady viscous flow (§5) are obtained from simulation of unsteady flow processes beginning from an initial condition of potential peristaltic flow. For nonlinear flows due to a single peristaltic wave of dilatation, the highest stresses and energy exchange rates (§6) occur along the wall and in two instantaneous stagnation regions in the bolus core. A series of computations for periodic wave trains reveals that increasing the Reynolds number from 2[sdot ]3 to 251 yields a modest augmentation in the ratio of flow rate to Reynolds number but induces a much greater increase in the shear stress (§7.1). The transport effectiveness is markedly reduced for pumping against a mild adverse pressure drop (§7.2). Increasing the wave amplitude will lead to the development of travelling vortices within the core region of the peristaltic flow (§7.3).

Journal ArticleDOI
TL;DR: Tissue sections of the hypothalamus were examined by immunoperoxidase technique and light microscopy using antisera to oxytocin and arginine vasopressin, and an antiserum which reacts with all rat neurophysins.
Abstract: Adrenal regulation of the vasopressincontaining fibers to the portal capillary system in the zona externa of the median eminence was studied in the rat. Tissue sections of the hypothalamus were examined by immunoperoxidase technique and light microscopy using antisera to oxytocin and arginine vasopressin, and an antiserum which reacts with all rat neurophysins. These peptides were localized in the intact normal rat and after adrenalectomy, glucocorticoid replacement with dexamethasone, and after dehydration. The effect of adrenalectomy was also examined in the homozygous Brattleboro rat with diabetes insipidus (DI rat) which lacks arginine vasopressin and, arginine vasopressinneurophysin. In the zona externa of the normal rat a small number of arginine vasopressin and neurophysin- containing fibers, and an occasional one containing oxytocin were traced to the portal capillary bed. The zona externa of the unoperated DI rat contained only an occasional neurophysin- and oxytocin-reactive fiber. In the normal...

Journal ArticleDOI
TL;DR: In this article, male and female college students, divided according to levels of achievement motivation, were asked to do an anagram task at which their success or failure was determined by experimental manipulation of the problems they were given.
Abstract: Male and female college students, divided according to levels of achievement motivation, were asked to do an anagram task at which their success or failure was determined by experimental manipulation of the problems they were given. Their ratings of ability, effort, task difficulty, and luck as possible causes for success or failure indicated that those with high achievement motivation of both sexes made relatively higher ratings for ability and lower ratings for task difficulty. Females tended to employ higher ratings for luck, and females with high achievement motivation made maximal use of effort as a causal factor. Theoretical implications and potential applications of these data are discussed.

Journal ArticleDOI
TL;DR: The results demonstrate differential effects of alcohol depending on the type of drug recipient (dominant, experienced subordinate, or naive) and the drug had greater effect on attack behavior than on defensive-submissive reactions.
Abstract: The effects of alcohol on fighting behavior in pairs of rats were studied when either the dominant or the subordinate animal was given the drug. Intense fighting episodes, consisting of all major acts and postures of attack, threat, defense, and submission, were generated between two otherwise isolated male Sprague-Dawley rats in a situation in which the accustomed food reinforcement was omitted. Alcohol (10% w/v) was administered intraperitoneally 10 min prior to the fighting test. A low dose (0.5 g/kg), when given to the dominant animal, increased the frequency of biting attack and prolonged the display of the aggressive posture. Higher doses of alcohol (1.0, 1.5 g/kg) suppressed attack behavior and, when given to the subordinate animal, impaired defensive upright postures. In a further experiment, animals without fighting or drug experience were subjected to attack by a non-treated dominant animal. When treated with alcohol (1.0, 1.5 g/kg) naive rats were more frequently attacked and injured, but reacted more readily to initial attacks by submissive-supine postures. The results demonstrate differential effects of alcohol depending on the type of drug recipient (dominant, experienced subordinate, or naive). The drug had greater effect on attack behavior than on defensive-submissive reactions.

Journal ArticleDOI
TL;DR: The authors compared 17 abused children with 17 children who had been in accidents, matched for age, race, sex, and socioeconomic status, eight years after all had been studied as infants.
Abstract: This study compared 17 abused children with 17 children who had been in accidents, matched for age, race, sex, and socioeconomic status, eight years after all had been studied as infants Each traumatized group was also compared with a matched untraumatized group with no known history of abuse or infantile accident The majority of all children were lower-class Hypotheses were that the abused children would fall below the nonabused in health history and physical development, intellectual functioning, language, and self-concept; and that the abused children would score higher in impulsivity and aggression Clinical assessments revealed few group differences The surprising finding was the extent of various problems across the entire sample Seventy percent of the children had speech problems; over 50% showed some degree of disturbance; and 39% were achieving poorly in school However, these disabilities were distributed randomly among abuse, accident, and comparison children Most of the children appeared sad and fearful of personal attack by adults or other children Many mothers' reports indicated that the families, whether abuse, accident, or comparison, experienced constant violence, both environmental and personal It was concluded that the effects on child development of lower-class membership may be as powerful as abuse Language: en