Showing papers by "University of Rochester published in 1979"
TL;DR: In this article, the authors examine ways in which debt contracts are written to control the conflict between bondholders and stockholders and find that extensive direct restrictions on production/investment policy would be expensive to employ and are not observed.
2,433 citations
1,245 citations
TL;DR: The authors found that self-serving effects for both success and failure are obtained in most but not all experimental paradigms, and that these attributions are better understood in motivational than in information-processing terms.
Abstract: Do causal attributions serve the need to protect and / or enhance self-esteem? In a recent review, Miller and Ross (1975) proposed that there is evidence for self-serving effect in the attribution of success but not in the attribution of failure; and that this effect reflects biases in information-processing rather than self-esteem maintenance. The present review indicated that self-serving effects for both success and failure are obtained in most but not all experimental paradigms. Processes which may suppress or even reverse the self-serving effect were discussed. Most important, the examination of research in which self-serving effects are obtained suggested that these attributions are better understood in motivational than in information-processing terms.
1,144 citations
TL;DR: In this article, the treatment of residuals associated with principal component analysis (PCA) is discussed, i.e., the difference between the original observations and the predictions of them using less than a full set of principal components.
Abstract: This paper is concerned with the treatment of residuals associated with principal component analysis. These residuals are the difference between the original observations and the predictions of them using less than a full set of principal components. Specifically, procedures are proposed for testing the residuals associated with a single observation vector and for an overall test for a group of observations. In this development, it is assumed that the underlying covariance matrix is known; this is reasonable for many quality control applications where the proposed procedures may be quite useful in detecting outliers in the data. A numerical example is included.
1,111 citations
TL;DR: Expressions are derived for the probability p(n) that n photons are emitted in a given time in the steady state by a two-level atom, when it is placed in a resonant, coherent, exciting field, which is shown to be narrower than Poissonian.
Abstract: Expressions are derived for the probability p(n) that n photons are emitted in a given time in the steady state by a two-level atom, when it is placed in a resonant, coherent, exciting field. The distribution p(n) is shown to be narrower than Poissonian. The ratio [〈(Δn)2〉 − 〈n〉]/〈n〉 is negative and has an absolute maximum value of 3/4. The possibility of observing the sub-Poissonian statistics is discussed briefly.
960 citations
Journal Article•
TL;DR: In this article, accounting theories are analyzed as economic goods, produced in response to the demand for theories, and the nature of the demand is examined, first in an unregulated, then in a regulated economy.
Abstract: This paper addresses the questions of why accounting theories are predominantly normative and why no single theory is generally accepted Accounting theories are analyzed as economic goods, produced in response to the demand for theories The nature of the demand is examined, first in an unregulated, then in a regulated economy Government regulation creates incentives for individuals to lobby on proposed accounting procedures, and accounting theories are useful justifications in the political lobbying Further, government intervention produces a demand for a variety of theories, because each group affected by an accounting change demands a theory that supports its position The diversity of positions prevents general agreement on a theory of accounting, and accounting theories are normative because they are used as excuses for political action (ie, the political process creates demand for theories that prescribe, rather than describe, the world) The implications of the authors' theory for the changes in the accounting literature as a result of major changes in the institutional environment are compared with observed phenomena
697 citations
TL;DR: A model of aging in the central nervous system in which one population of neurons dies and regresses and the other survives and grows is suggested, which appears to be the dominant population in aging without dementia.
Abstract: Golgi-stained dendrites of single randomly chosen layer-II pyramidal neurons in the human parahippocampal gyrus were quantified with a computer-microscope system. In nondemented aged cases (average age, 79.6 years), dendritic trees were more extensive than in adult cases (average age, 51.2), with most of the difference resulting from increases in the number and average length of terminal segments of the dendritic tree. These results provide morphological evidence for plasticity in the mature and aged human brain. In senile dementia (average age, 76.0), dendritic trees were less extensive than in adult brains, largely because their terminal segments were fewer and shorter. Cells with shrunken dendritic trees were found in all brains. These data suggest a model of aging in the central nervous system in which one population of neurons dies and regresses and the other survives and grows. The latter appears to be the dominant population in aging without dementia.
457 citations
TL;DR: Liposomes with phase transitions a few degrees above physiological temperature delivered more than four times as much methotrexate to murine tumors heated to 42 degrees C as to unheated control tumors.
Abstract: Liposomes with phase transitions a few degrees above physiological temperature delivered more than four times as much methotrexate to murine tumors heated to 42 degrees C as to unheated control tumors. Most of the accumulated drug appeared to be intracellular and bound to dihydrofolate reductase, the enzyme blocked by methotrexate in its role as an antineoplastic agent.
355 citations
331 citations
TL;DR: In this article, the authors present iterative techniques for obtaining reduced rank approximation of matrices when weights are introduced, which involve criss-cross regressions with careful initialization, and possible applications of the approximation are in modelling, biplotting, contingency table analysis, fitting of missing values, checking outliers, etc.
Abstract: Reduced rank approximation of matrices has hitherto been possible only by unweighted least squares. This paper presents iterative techniques for obtaining such approximations when weights are introduced. The techniques involve criss-cross regressions with careful initialization. Possible applications of the approximation are in modelling, biplotting, contingency table analysis, fitting of missing values, checking outliers, etc.
311 citations
TL;DR: Experiments I and 2 demonstrated that inhibition increased as the interval between contextual processing and target-word onset was lengthened and the relevance of these results to developmental investigations of the interaction of word recognition and contextual processing is discussed.
Abstract: In. Experiment I subjects named target words that were preceded by a congruous sentence context, an incongruous sentence context, or no sentence context, under stimulus conditions that were either normal or degraded by contrast reduction. Under normal stimulus conditions, a contextual facilitation effect, but no contextual inhibition effect, was observed. When the target word was degraded, both contextual facilitation and inhibition were observed. Experiment 2 replicated the increase in contextual inhibition under degraded conditions and also demonstrated that inhibition increased as the interval between contextual processing and target-word onset was lengthened. The results were interpreted within the framework of the Posner and Snyder two-process theory of expectancy. Thus, when target-word recognition is rapid, only the fast-acting automatic activation component of context effects has time to operate. When target-word processing is delayed, the conscious-attention mechanism, which is responsible for inhibition effects, becomes operative. The relevance of these results to developmental investigations of the interaction of word recognition and contextual processing is discussed.
TL;DR: Histopathological changes that were observed in normal brain tissue that was irradiated with 7000–8000 rad suggest that increasing total doses beyond this range might attain tumor sterilization, but could also lead to frank radiation necrosis in these patients.
Abstract: One hundred patients with supratentorial malignant gliomas were prescribed to receive postoperative whole brain irradiation with doses ≥5000 rad; 41 had astrocytoma grade III and 59 had grade IV tumors. The median survival was 91 weeks for patients with grade III tumors and only 42 weeks for those with grade IV (p For patients with grade IV tumors the median survival was 30, 42 and 56 weeks respectively, these differences were significant (p The use of higher radiation doses was well tolerated; it did not compromise the quality of survival, and did not yield normal brain tissue necrosis. However, these doses did not seem to alter the total survival of patients, nor did they seem capable of sterilizing these tumors. Histopathological changes that were observed in normal brain tissue that was irradiated with 7000–8000 rad suggest that increasing total doses beyond this range might attain tumor sterilization, but could also lead to frank radiation necrosis in these patients.
TL;DR: Spheroids of EMT-6 mammary tumor cells were markedly more resistant to different exposure doses of Adriamycin than monolayer cells in exponential or plateau growth phases and Pretreatment of spheroids with misonidazole before ADR effectively reduced this resistant population of cells.
Abstract: Spheroids of EMT-6 mammary tumor cells were markedly more resistant to different exposure doses of Adriamycin (ADR) than monolayer cells in exponential or plateau growth phases. For example, after 1 hr exposures to 0.5 μ/ml, surviving fractions determined by colony formation assay were approximately 0.3 for cells from spheroids treated intact and 0.001 for single exponential phase cells. To evaluate whether this resistance was related to poor drug uptake the distribution of the natural fluorescence of ADR equivalents was determined fluorimetrically and by direct microscopic observations. A concentration gradient of fluorescence was observed from the outside to the centers of spheroids even after high concentrations (10 μ/ml) and long exposure times (2 hrs). Cells from dissociated spheroids took up more drug than intact spheroids further indicating the existence of a significant diffusion barrier. When the surviving fraction of cells was plotted versus absorbed ADR equivalents the cells in intact spheroids were still more resistant and both curves were bicomponent with the most resistant fraction comprising about 20% of the cells. By using a selective disaggregation technique after intact spheroids had been exposed to the drug it was possible to show directly that the inner spheroid cells were most resistant (D 0 = 0.25 μ/10 6 cells). This resistance was not due to differences in the cell cycle state of these inner cells since separate experiments showed that both exponential and plateau phase monolayer cells were about equally sensitive when the surviving fraction was plotted vs absorbed drug (D 0 , = 0.04 μ/10 6 cells). Thus, other factors related to the metabolic state of the cells, the microenvironment, or the formation of different drug products must account for the observed resistance. Pretreatment of spheroids with misonidazole before ADR effectively reduced this resistant population of cells.
TL;DR: The results presented here show that paromomycin, which contains paromamine, is capable of phenotypic suppression of the nonsense mutations in S. cerevisiae.
Abstract: STREPTOMYCIN, an aminoglycoside antibiotic, can reverse the mutant phenotypes of many nonsense and missense mutations in Escherichia coli and in bacteriophage T4. This phenomenon has been called phenotypic suppression, since the mutant phenotype returns after removal of the drug1. The most likely explanation for phenotypic suppression is that streptomycin promotes mistranslation in vivo, and that acceptable amino acids are inserted into the growing polypeptide chain at the site of the mutant codon. Consistent with this view is the observation that streptomycin causes E. coli ribosomes to mistranslate RNA in vitro2,3. Streptomycin and neomycin have however been found to have no effect in stimulating ribosomes from eukaryotic cells to mistranslate RNA in vitro4,5. A subclass of the aminoglycoside antibiotics has been shown6,7 to stimulate eukaryotic ribosomes to misread RNA. The highly active molecules are distinguished in that they contain the drug fragment paromamine (or 3′-deoxyparomamine). We have therefore examined the capacity of various aminoglycosides to suppress mutations phenotypically in the eukaryotic yeast, Saccharomyces cerevisiae. The results presented here show that paromomycin, which contains paromamine, is capable of phenotypic suppression of the nonsense mutations in S. cerevisiae.
TL;DR: The use of alpha-aminoadipate medium has considerable utility as a selective medium for lys2 and lys5 mutants as well as other possible auxotrophic requirements.
Abstract: Normal strains of Saccharomyces cerevisiae do not use α-aminoadipate as a principal nitrogen source. However, α-aminoadipate is utilized as a nitrogen source by lys2 and lys5 strains having complete or partial deficiencies of α-aminoadipate reductase and, to a limited extent, by heterozygous lys2/+ strains. Lys2 mutants were conveniently selected on media containing α-aminoadipate as a nitrogen source, lysine, and other supplements to furnish other possible auxotrophic requirements. The lys2 mutations were obtained in a variety of laboratory strains containing other markers, including other lysine mutations. In addition to the predominant class of lys2 mutants, low frequencies of lys5 mutants and mutants not having any obvious lysine requirement were recovered on α-aminoadipate medium. The mutants not requiring lysine appeared to have mutations at the lys2 locus that caused partial deficiencies of α-aminoadipate reductase. Such partial deficiencies are believed to be sufficiently permissive to allow lysine biosynthesis, but sufficiently restrictive to allow for the utilization of α-aminoadipate. Although it is unknown why partial or complete deficiencies of α-aminoadipate reductase cause utilization of α-aminoadipate as a principal nitrogen source, the use of α-aminoadipate medium has considerable utility as a selective medium for lys2 and lys5 mutants.
TL;DR: In this article, an empirical model of nutrient-saturated phytoplankton growth can be quantitatively described by four equations: an empirical equation relating growth rate ~1, to absorbed irradiance [; a different equation relating b and 4 derived from the empirical equation of gross photosynthesis to irradiance; a respiratory rate constant R, to growth rate; and an equation stating the approximate constancy of the ratio &JO of the light saturation parameter & of the photosynthetic light curve and the C:Chl a quotient 8.
Abstract: Steady state, nutrient-saturated phytoplankton growth can be quantitatively described by four equations: an empirical equation relating growth rate ~1, to absorbed irradiance [; a different equation relating b and 4 derived from the empirical equation relating instantaneous rate of gross photosynthesis to irradiance; an empirical equation relating the respiratory rate constant R, to growth rate; and an equation stating the approximate constancy of the ratio &JO of the light saturation parameter & of the photosynthetic light curve and the C:Chl a quotient 8. The equations involve eight constant parameters which were evaluated for Chlorella pyrenoidosa from data in the literature. The four equations do not incorporate an cmpirical description of the adaptive parameter functions &&) or @(CL,). However, the equations can be solved simultaneously to obtain these functions. The derived functions agree with the experimental ones for C. pyrenoidosa. Since the equations not only describe respiration and the light curves of growth and photosynthesis, but also predict &, and 8, they constitute an improved model of nutrient-saturated algal growth: given any irradiance, the equations predict 11.8, R,, &,, and 8 and the specific light curve of photosynthesis. The model provides a necessary foundation for subsequent description of nutrient-limited growth in culture and in nature.
TL;DR: Treatments in vivo of Escherichia coli with oxolinic acid, a potent inhibitor of DNA gyrase and DNA synthesis, lead to DNA cleavage when extracted chromosomes are incubated with sodium dodecyl sulfate, indicating there are approximately 45 DNA breaks per chromosome.
TL;DR: It is suggested that gastric, pancreatic, and biliary responses to liquid test meals introduced into the stomach may differ substantially from the presumably more physiological response to ordinary solid-liquid meals.
Abstract: We have compared responses to an ordinary solid-liquid (S) meal and to a homogenized (H) meal of identical composition (sirloin steak, bread, butter, ice cream with chocolate syrup, and water) by measuring simultaneously postprandial gastric, pancreatic, and biliary functions by marker-perfusion techniques Responses to each (S or H) meals differed strikingly both in magnitude and pattern S meals elicited a stronger early gastric secretory response (acid, pepsin, and volume) which compensated for faster initial emptying and resulted in higher gastric acidity and volume than after H meals Further, nutrients ingested with S meals were emptied at a slower rate than H (as evidenced by a more gradual decline in intragastric buffer and osmolality, as well as time required for complete emptying of the meal) This, in turn, prolonged pancreatic and biliary responses since stimulation of these organs continued for as long as meal was delivered into the duodenum However, early biliary outputs (gallbladder response) were less after S than H, probably because nutrients entered the duodenum more slowly and were initially diluted by rapidly emptying water The physical characteristics of each meal (encompassing appearance, taste, and form of ingestion) probably accounted for early differences in digestive responses Later, interactions between gastric (motor and secretory), pancreatic, and biliary functions played a major role Our findings suggest that gastric, pancreatic, and biliary responses to liquid test meals introduced into the stomach may differ substantially from the presumably more physiological response to ordinary solid-liquid meals
TL;DR: It was concluded that this type of conservative management is effective in the majority of athletes with symptomatic patellofemoral syndromes, and that surgical treatment should be necessary for only the relative few who fail to respond to an adequate trial of conservative treatment.
Abstract: A comprehensive conservative management program for chondromalacia patella in athletes has been presented. The clinical manifestations and the efficacy of conservative treatment have been documented in the prospective study of 100 consecutive athletes. The over-all success rate was 82%, and 18% were considered to be failures of conservative treatment. Only 8 of these 100 athletes have required surgical treatment. It was concluded that this type of conservative management is effective in the majority of athletes with symptomatic patellofemoral syndromes, and that surgical treatment should be necessary for only the relative few who fail to respond to an adequate trial of conservative treatment.
TL;DR: Patients with polymyositis may have a cardiopathy in the absence of overt myocardial inflammatory disease, and these patients may have the potential to have congestive heart failure without needing to be admitted to hospital.
Abstract: Cardiac involvement in polymyositis was investigated in 20 autopsied cases. Clinically, 13 of 18 patients had abnormal electrocardiograms, and 9 of the 20 patients had previous evidence of congestive heart failure. Histologically documented myocarditis was detected in 6 patients (4 with congestive heart failure and 2 without), 4 of whom also had small vessel disease of the myocardium. Patients with polymyositis may have a cardiopathy in the absence of overt myocardial inflammatory disease.
TL;DR: An approach to distributed computing at the level of general purpose programming languages is described, based on primitive notions of module, message, and transaction key, which appears to be useful for programming a wide range of tasks.
Abstract: Programming for distributed and other loosely coupled systems is a problem of growing interest This paper describes an approach to distributed computing at the level of general purpose programming languages Based on primitive notions of module, message, and transaction key, the methodology is shown to be independent of particular languages and machines It appears to be useful for programming a wide range of tasks This is part of an ambitious program of development in advanced programming languages, and relations with other aspects of the project are also discussed
TL;DR: This paper presented a rational-choice theory of how decision makers choose sides, or neutrality, in ongoing wars, focusing on each nation's expected utility from the war's possible outcomes, and on each country's utility for its available strategies.
Abstract: We present a rational-choice theory of how decision makers choose sides, or neutrality, in ongoing wars. The theory focuses on each nation's expected utility from the war's possible outcomes, and on each nation's utility for its available strategies. Once the decision-making calculus is specified, the theory is tested against more than two thousand national decisions to remain neutral or to join an ongoing war on one side or the other. The theory proves to have considerable explanatory power, with the results of the data analysis indicating that the basic decision-making calculus used to choose sides in wars has not changed substantially during the past century and a half, although there have been some adjustments upwards and downwards in the relative importance of particular elements in the calculus.
TL;DR: In this article, a new atom identification and detection technique for ultrasensitive mass spectrometry has been applied to the radionuclide 36Cl and the results showed that the 36Cl/Cl ratio in AgCl precipitated from six different natural water samples with a background level below 3 × 10−15.
Abstract: A new atom identification and detection technique for ultrasensitive mass spectrometry has been applied to the radionuclide 36Cl. Measurements of the 36Cl/Cl ratio in AgCl precipitated from six different natural water samples fell in the range 1.2 × 10−13−2 × 10−12 with a background level below 3 × 10−15. For each sample 70 mg of AgCl was used, requiring 1–51 of water.
TL;DR: It is suggested that brief courses of high-dose prednisone therapy may limit the adrenal component of the hypothalamic-pituitary-adrenal response to stress for up to five days.
TL;DR: In this paper, the authors compared the theoretical excitation functions for heavy-ion induced reactions over a wide mass range with results calculated with a classical dynamical model based on the proximity nuclear potential of Blocki et al., the Coulomb potential of Bondorf et al.
TL;DR: The isolated rat liver perfusion technique and a competitive protein-binding assay to measure one of the SMs and its carrier protein and the net cumulative release of these peptides from normal and hypophysectomized rat livers has been studied.
Abstract: Previous studies have indicated that one or more GH-dependen t somatomedins (SMs) are either synthesized or at least released by the liver. Employing the isolated rat liver perfusion technique and a competitive protein-binding assay to measure one of the SMs [insulin-like growth factor (IGF)] and its carrier protein (CP), the net cumulative release of these peptides from normal and hypophysectomized (hypox) rat livers has been studied. The IGF concentration in the perfusates of seven normal livers increased rapidly during the initial 2 h and more gradually during the remainder of a 12-h perfusion. The mean (± SEM) net cumulative release of IGF at 12 h was 5620 ± 740 μU/300 cm2 (donor body surface area). In contrast to the pattern of IGF release, the release of CP was very slow initially but increased rapidly by the 12th h to 5.0 ± 0.9 mg/300 cm2. The addition of bovine GH to the perfusions of six normal livers caused a significant increase in the release of IGF(9210 ± 850 μU/300 cm2) but not of CP (5.4 ± ...
TL;DR: In this paper, the impression creep of β-tin single crystals was studied in three orientations: [001, [100] and [110] and the temperature dependence of the steady state impression velocity showed two parallel processes.
TL;DR: Myoplasmic calcium transients in response to pulse depolarisations have been monitored using the dye antipyralazo III, which provides a linear measure of the change in cytoplasmic free calcium concentration.
Abstract: Myoplasmic calcium transients in response to pulse depolarisations have been monitored using the dye antipyralazo III, which provides a linear measure of the change in cytoplasmic free calcium concentration. Intramembrane charge movements were recorded simultaneously with the calcium transients. Except for its initial phase, the calcium transient during each pulse closely followed the time course expected for calcium redistribution between three intracellular compartments with time-independent flux coefficients. The time at which the flux coefficients attained their steady values occurred just after the intramembrane charge movement had been completed. This is the required sequence if charge movement were to control one or more coefficients f or calcium fluxes across the sarcoplasmic reliculum membrane.