Showing papers by "University of Iowa published in 1982"
TL;DR: In this paper, a scale to assess the need for cognition (i.e., the tendency for an individual to engage in and enjoy thinking) was developed and validated, and a factor analysis was performed on the selected items and yielded one major factor.
Abstract: Four studies are reported in which a scale to assess the need for cognition (i.e., the tendency for an individual to engage in and enjoy thinking) was developed and validated. In Study 1 a pool of items was administered to groups known to differ in need for cognition. Members of a university faculty served as subjects in the high-need-for-cognition group, whereas assembly line workers served as subjects in the low-need-for-cognition group. The criteria of ambiguity, irrelevance, and internal consistency were used to select the items for subsequent studies. A factor analysis was performed on the selected items and yielded one major factor. In 'Study 2 the scale was administered to a more homogeneous population (400 undergraduates) to validate the factor structure obtained in Study 1 and to determine whether the scale tapped a construct distinct from test anxiety and cognitive style. The factor structure was replicated in Study 2, responses to the need for cognition scale were predictably and weakly related to cognitive style, and responses were unrelated,to test anxiety. In Study 3, 104 subjects completed need for cognition, social desirability, and dogmatism scales and indicated what their American College Test scores were. Results indicated that need for cognition was related weakly and negatively to being close minded, unrelated to social desirability, and positively correlated with general intelligence. Study 4 replicated the major findings of Study 3 and furnished evidence of thj predictive validity of the Need for Cognition Scale: Attitudes toward simple an complex versions of a cognitive task appeared indistinguishable until the subjects' need for cognition was considered. The theoretical utility of the construct and measure of need for cognition are discussed.
4,801 citations
TL;DR: The developed Scale for the Assessment of Negative Symptoms has excellent interrater reliability and the five symptom complexes defined by the scale have good internal consistency, which indicates that the conceptual organization of the scale is also cohesive.
Abstract: • Recently, a renaissance of interest in "negative symptoms," eg, affective flattening or impoverishment of speech and language, has occurred. Although some investigators believe that these symptoms are important indicators of outcome, of response to treatment, and perhaps of a distinct, underlying pathologic process, research on the negative-symptom syndrome in schizophrenia has been handicapped because no standard instrument existed to assess it. This investigation reports on the developed Scale for the Assessment of Negative Symptoms. When symptoms are defined by objective behavioral indices, they have excellent interrater reliability. Furthermore, the five symptom complexes defined by the scale (affective flattening, alogia, avolition, anhedonia, and attentional impairment) have good internal consistency, which indicates that the conceptual organization of the scale is also cohesive.
2,136 citations
TL;DR: Criteria for dividing the schizophrenic syndrome into three subtypes was developed: positive, negative, and mixed schizophrenia, and significant differences were noted using external validators such as premorbid adjustment, indices of cognitive dysfunction, ventricular brain ratio, and course in hospital.
Abstract: • We developed criteria for dividing the schizophrenic syndrome into three subtypes: positive, negative, and mixed schizophrenia. Positive schizophrenia is characterized by prominent delusions, hallucinations, positive formal thought disorder, and persistently bizarre behavior; negative schizophrenia, by affective flattening, alogia, avolition, anhedonia, and attentional impairment. In mixed schizophrenia either both negative and positive symptoms are prominent, or neither is prominent. We explored the validity of these criteria in a variety of ways. Significant differences between the three types were noted using external validators such as premorbid adjustment, indices of cognitive dysfunction, ventricular brain ratio, and course in hospital. The correlational structure of the symptom complexes also provided further support for our approach to subtyping.
2,010 citations
TL;DR: In this paper, a model of optimal dividend payout is presented in which increased dividends lower agency costs but raise the transactions cost of external financing, and the optimal dividend payment minimizes the sum of these two costs.
Abstract: A model of optimal dividend payout is presented in which increased dividends lower agency costs but raise the transactions cost of external financing. The optimal dividend payout minimizes the sum of these two costs. A cross-sectional test of the model relates dividend payout to the fraction of equity held by insiders, the past and expected future revenue growth of the firm, the firm's beta coefficient, and the number of common stockholders. The coefficients of all variables are significant in the predicted directions. The results indicate that investment policy influences dividend policy.
1,220 citations
TL;DR: The weighted sum of gray gases model as discussed by the authors is a generalization of the weighted sum-of-gray-gas model, which assumes that total emissivity and absorptivity may be represented by the sum of the gray gas emissivities weighted with a temperature dependent factor.
Abstract: The weighted sum of gray gases model postulates that total emissivity and absorptivity may be represented by the sum of a gray gas emissivity weighted with a temperature dependent factor. The gray gas emissivity is expressed in terms of a temperature-independent absorption coefficient, absorbing gas partial pressure, and path length. The weighting factors are given by polynomials in gas temperature with associated polynomial coefficients. For absorptivity, a second polynomial for the irradiation temperature is introduced. A regression scheme is employed to fit the model to total emissivity and absorptivity values obtained from the exponential wide-band model. Absorption and polynomial coefficients are reported for carbon dioxide, water vapor, and mixtures of these gases. The model with these coefficients more accurately represents the total properties over a wider range of temperatures and partial pressure-path length products than previously available coefficients.
928 citations
743 citations
741 citations
TL;DR: The Causal Dimension Scale as mentioned in this paper assesses causal perceptions in terms of the locus ofcausality, stability, and controllability dimensions described by Weiner, and three-modefactor analysis confirmed the three-dimensional structure of the scale.
Abstract: Dan RussellCollege of Medicine, University of IowaA shortcoming of previous attribution research has been the assumption thatresearchers can accurately translate causal attributions into causal dimensions.Attributional statements are often ambiguous and even when clearly stated maybe perceived quite differently by the attributor and the researcher. The studiesreported describe the development of the Causal Dimension Scale, a measuredesigned to assess how the attributor perceives the causes he or she has statedfor an event. This scale assesses causal perceptions in terms of the locus ofcausality, stability, and controllability dimensions described by Weiner. Twostudies are reported that test the reliability and validity of the Causal DimensionScale. All three subscales were found to be reliable and valid, and a three-modefactor analysis confirmed the three-dimensional structure of the scale. Resultsalso indicated differences in the perception of causes of success and failure, withattributions for success being perceived as more internal, stable, and controllablethan attributions for failure. The relationship between the Causal DimensionScale and other attribution measures (such as locus of control or "attributionalstyle" measures) is discussed.
687 citations
641 citations
TL;DR: It is suggested that combining a measure of brain structure with the clinical picture may provide a useful new approach to the classification of schizophrenia.
Abstract: The authors explored the clinical correlates of ventricular enlargement in schizophrenia by comparing 16 patients with "large" ventricles (ventricles more than I SD above the control mean) with 16 patients with the smallest ventricles from a sample of 52 schizophrenic patients Patients with ventricular enlargement showed some impairment in the sensorium and had a preponderance of "negative" symptoms (eg, alogia, affective flattening, avolition, anhedonia), while those with small ventricles were characterized by "positive" symptoms (eg, delusions, hallucinations, positive formal thought disorder, bizarre behavior) These findings suggest that combining a measure of brain structure with the clinical picture may provide a useful new approach to the classification of schizophrenia
418 citations
TL;DR: In this paper, it was shown that Extremely Low Frequency (low frequency) or "lion" roars are closely coupled to quasi-periodic, large scale magnetosheath structures.
Abstract: It is shown that Extremely Low Frequency, or 'lion' roars are closely coupled to quasi-periodic, large scale magnetosheath structures. Because the latter are waves generated by the drift mirror instability, an attempt is made to identify and describe the magnetic and plasma features associated with this instability. Observations and analyses of the large scale structures using ISEE 1 and 2 data for the earth's magnetosheath and Pioneer 11 data for Jupiter and Saturn are presented, along with the background of the drift mirror waves. The cyclotron and drift mirror instabilities occurring in the magnetosheath are natural relaxation processes which reduce the plasma pressure anisotropies created by preferential heating of the solar wind plasma as it passes through the bow shock, as well as the compression occurring when the plasma and fields approach the near-subsolar magnetopause.
TL;DR: The findings raise the question of participation of the dominant striatum, and of the connectional systems that course in the anterior limb of the internal capsule, in language processing.
Abstract: • Atypical aphasia syndromes were associated with circumscribed nonhemorrhagic infarctions of the anterior limb of the internal capsule and of the striatum, in the dominant hemisphere. None of the several cases could be classified in terms of the classic cortical aphasia syndromes, nor did they correspond to the description of aphasia produced by hemorrhage in the thalamus or putamen. Control subjects without aphasia had lesions in the same structures of the nondominant hemisphere, or they had comparably circumscribed damage, which was located lateral or caudal to the previously indicated locus. The findings raise the question of participation of the dominant striatum, and of the connectional systems that course in the anterior limb of the internal capsule, in language processing.
TL;DR: This overview of data analysis in exploratory research in psychiatry discusses special statistical approaches that are available to reduce error risk, such as the Bonferroni inequality.
Abstract: Many traditional statistical approaches to data analysis assume a relatively simple situation in which the investigator is testing a single hypothesis. Most research in psychiatry, on the other hand, is exploratory in nature and involves testing many hypotheses. Exploratory research presents special problems in data analysis, which are discussed in this overview. Special statistical approaches that are available to reduce error risk, such as the Bonferroni inequality, are described. The importance of selecting confidence levels appropriate to a particularly investigation, rather than arbitrary use of the .05 level, is also discussed.
TL;DR: The learned helplessness model of depression was tested for its responsiveness to several types of antidepressant therapies, and to a number of psychoactive drugs which are not effective in treating depression in humans.
Abstract: The learned helplessness model of depression was tested for its responsiveness to several types of antidepressant therapies, and to a number of psychoactive drugs which are not effective in treating depression in humans Chronic administration of tricyclic antidepressants (imipramine, desipramine, amitryptyline, nortryptyline, or doxepin), atypical antidepressants (iprindole or mianserin), monoamine oxidase inhibitors (iproniazid or pargyline), or electroconvulsive shock was effective in reversing learned helplessness Chronic treatment with anxiolytics (diazepam, lorazepam, or chlordiazepoxide), neuroleptics (chlorpromazine or haloperidol) stimulants (amphetamine or caffeine), or depressants (phenobarbital or ethanol) was not Thus, this model provides a reasonable degree of specificity toward therapies which are successful in humans
TL;DR: The connections of the subfornical organ (SFO) wer investigated by using the HRP technique and labeled cells were observed in the median preoptic nucleus, below the ependyma of the third ventricle, in the dorsal pre optic region near the anterior commissure, and diffusely throughout the medial preopti and anterior bypothalamic areas.
Abstract: The connections of the subfornical organ (SFO) wer investigated by using the HRP technique. Injections into the SFO labeled neurons in the medial septum, but not in lateral septum nor in the diagonal band nucleus. Labeled cells were observed in the median preoptic nucleus, below the ependyma of the third ventricle, in the dorsal preoptic region near the anterior commissure, and diffusely throughout the medial preoptic and anterior bypothalamic areas.
Fibers were followed from the ventral stalk of the SFO. Precommissural fibers enter the median preoptic nucleus where many of them appear to terminate. Others continue on to the medial septum, the OVLT, the supraoptic nucleus, and the suprachiasmatic nucleus, HRP injections into the median preoptic nucleus labled many neurons in the SFO.
Postcommissural fibers reach the hypothalamus by descending along the walls of the ventricle in the subependymal space, by traveling in the columns of the fornix and the medial corticohypothalamic tract, or by passing through the paraventricular nucleus of the thalamus. Some postcommissural fibers turn rostrally and enter the median preoptic nucleus while others join precommissural fibers bound for the supraoptic nucleus. More caudally directed fibers appear to innervate the paraventricular nucleus of the hypothalamus and the medial preoptic and anterior hypothalamic areas. HRP injections into the paraventricular nucleus of the hypothalamus labeled neurons in the SFO.
These finding corroborate and extend previous work in describing neural connections between two brain regions that are important for fluid blance.
Patent•
13 Dec 1982TL;DR: In this article, an elongated tube is adapted to be inserted into the body so that its internal end is positioned adjacent the tissue which is to be sutured, and a plunger is sized to slide within the tube and includes at one end a grasping mechanism for releaseably grasping a pair of needles in spaced-apart relation to one another.
Abstract: The device of the present invention comprises an elongated tube which is adapted to be inserted into the body so that its internal end is positioned adjacent the tissue which is to be sutured. A plunger is sized to slide within the tube and includes at one end a grasping mechanism for releaseably grasping a pair of needles in spaced-apart relation to one another. The plunger is fitted within the tube and the needles are forced outwardly through the lower end of the tube so that they penetrate and extend through the tissue to be sutured. The needles are forced through the tissue to be sutured and are forced outwardly through the skin layer of the patient so that they can be grasped and pulled from the releaseable grasping mechanism of the plunger.
TL;DR: It is concluded that panic disorder accounted for much of the excess mortality formerly noted in the "neuroses," and secondary depression and alcoholism may have had a role in these deaths.
Abstract: • We located 113 former inpatients with panic disorder 35 years after index admission. According to age-and sex-specific Iowa population figures, patients with panic disorder had significant excess mortality due to death by unnatural causes. Other studies suggest that secondary depression and alcoholism may have had a role in these deaths. Men with panic disorder also exhibited excess mortality due to circulatory system disease. In an age-and sex-matched patient group with primary unipolar depression, both men and women showed excess mortality. Suicide accounted for 20.0% and 16.2% of deaths in the panic disorder and primary depression groups, respectively. We conclude that panic disorder accounted for much of the excess mortality formerly noted in the "neuroses."
TL;DR: The transcription of the human cytomegalovirus genome was investigated at immediate early, early, and late times after infection and it is proposed that expression of the immediate early viral genes is required to transcribe theEarly viral genes in the long repeat and adjacent sequences.
Abstract: The transcription of the human cytomegalovirus genome was investigated at immediate early, early, and late times after infection. Viral RNAs associated with either the whole cell, the nucleus, the cytoplasm, or the polyribosomes were analyzed. At immediate early times, i.e., in the absence of de novo viral protein synthesis, the viral RNA in high abundance originated from a region of the long unique section of the prototype arrangement of the viral genome (0.660 to 0.770 map units). The viral RNA in low abundance originated from the long repeat sequences (0.010 to 0.035 and 0.795 to 0.825 map units) and a region in the long unique section (0.201 to 0.260 map units). Viral RNAs associated with the polyribosomes as polyadenylated RNA were mapped to these restricted regions of the viral genome and characterized according to size class in kilobases. At 24 h after infection in the presence of an inhibitor of viral DNA replication, i.e., at early times, the stable viral RNAs in highest abundance mapped in the long repeat sequences. Viral RNAs at intermediate abundance under these conditions mapped in two regions of the long unique section of the viral genome (0.325 to 0.460 and 0.685 to 0.770 map units). Stable viral RNAs that were associated with the polyribosomes in high abundance as polyadenylated RNA orginated from the long repeat sequences, but not from the long unique section of the viral genome. An analysis of whole-cell RNA at late times (72 h) indicated that the abundant transcription was in the regions of the long unique sequences (0.325 to 0.460 and 0.660 to 0.685 map units), and transcription of intermediate abundance was from the long repeat sequences. However, stable viral mRNA's derived from the long repeat sequences were associated with the polyribosomes at late times after infection. In addition, mRNA's originating from the long and short unique sequences were found associated with the polyribosomes at higher relative concentration than at early times after infection. It is proposed that expression of the immediate early viral genes is required to transcribe the early viral genes in the long repeat and adjacent sequences. These sequences are also transcribed at late times after infection while viral DNA synthesis continues. The expression of viral genes in most of the long and short unique sequences appears to require viral DNA replication.
TL;DR: A scaling scheme is presented which substantially reduces errors in muscle force predictions and the inherent limitations of developing a straight line muscle model include right-to-left biological variations and/or marking errors.
Abstract: The mathematical prediction of muscle and joint force requires a quantitative knowledge of muscle origins and insertions. A model is presented based upon marking the origins and insertions in three cadavers (six limbs). Right-to-left biological variations and/or making errors are sometimes significant, but they rarely result in moment arm calculation variations of greater than 20 percent and usually the variations are less than 10 percent. The muscle origin and insertion differences between small and large cadavers is great, as would be expected, and the use of single specimen or average data will result in large errors in muscle force predictions. A scaling scheme is presented which substantially reduces those errors. The inherent limitations of developing a straight line muscle model include: 1) right-to-left biological variations and/or marking errors; 2) difficulties in establishing "effective" origins or insertions when the locations of the actual origin or insertion do not accurately reflect muscle function; and 3) intersubject variability which cannot be accounted for by simple scaling schemes.
TL;DR: In this article, the first global auroral images gained with the vacuum-ultraviolet imaging photometer on board DE 1 reveal a remarkable spatial configuration of auroral luminosities, suggesting a twocell structure of current systems and convection electric fields over the earth's polar cap and a similar division of the corresponding lobe in the magnetotail.
Abstract: Preliminary examination of the first global auroral images gained with the vacuum-ultraviolet imaging photometer on board DE 1 reveals a remarkable spatial configuration of auroral luminosities. Frequently the northern auroral oval is bifurcated by a sun-aligned arc extending from the midday auroral zone to the nighttime sector of the oval. Simultaneous plasma measurements with the low-altitude DE-2 spacecraft are used to show that the character of plasmas above the polar arc is similar to those found over the poleward zones of the auroral oval. The spatial distribution of auroral luminosities is suggestive of a two-cell structure of current systems and convection electric fields over the earth's polar cap and a similar division of the corresponding lobe in the magnetotail.
TL;DR: In this paper, the authors examined the relationship between the ownership control status of firms and the accounting methods they adopt and found that management controlled firms are more likely than owner controlled firms to adopt accounting methods which increase reported earnings.
TL;DR: The problem of state estimation and system structure detection for discrete stochastic dynamical systems with parameters which may switch among a finite set of values is considered and a unified treatment of the existing suboptimal algorithms is provided.
TL;DR: Size effects in quasistatic bending of compact bone are observed and are consistent with micropolar theory, and two nonclassical elastic constants are evaluated.
TL;DR: With age, a distinct pericellular matrix or “nest,” consisting of collagen fibrils, fine filaments, dense particles, and banded structures, formed around most cells with no apparent preference for viable or necrotic cells, suggesting accumulation of cell products.
Abstract: The cells of the intervertebral disc exist in a unique environment; not only are discs subject to large mechanical loads, they are the largest avascular structures in the body. To describe the ultrastructure and age changes in cells from human nucleus pulposus, we studied these cells in individuals ranging in age from the 26th week of fetal life to 91 years. Viable chondrocyte-like cells existed in specimens from all ages. The presence of Golgi cisternae and well-developed endoplasmic reticulum in these cells suggests that they are capable of producing and maintaining the extracellular matrix. Necrotic cells were also present in all samples, and many cells which appeared viable when examined by light microscopy proved to be necrotic when examined by electron microscopy. The percentage of necrotic cells increased with age from 2% or less in fetal specimens to over 50% in adults. In addition, with age, a distinct pericellular matrix or "nest," consisting of collagen fibrils, fine filaments, dense particles, and banded structures, formed around most cells with no apparent preference for viable or necrotic cells. Nest formation and increasing density of the cell nests may reflect accumulation of cell products.
TL;DR: The structure of notochordal cells and their persistence in the nucleus pulposus after fetal life suggest that they may have a significant role in the formation and maintenance of the nucleus Pulposus.
Abstract: We examined nucleus pulposus notochordal cells of individuals ranging in age from the eighth week of fetal life to 32 years of age. With increasing age, notochordal cell structure changed, as did the cell-to-cell relationships and the cell-to-chordal relationships. All notochordal cells contained normal organelles, including well-developed endoplasmic reticulum, but, in addition, fetal notochordal cells demonstrated an unusual relationship between rough endoplasmic reticulum and mitochondria: elements of the rough endoplasmic reticulum encircled almost every mitochondrion. Fetal notochordal cells contained large amounts of glycogen, while older cells had much smaller glycogen deposits. Cytoplasmic filaments were observed in cells of all ages. The cells formed tightly packed clusters in the fetus with little, if any, extracellular matrix between individual cells. Cells separated from each other with age and by the twenty-first week of fetal life, only slender strands of cytoplasm connected them. Previous light microscopic studies described notochordal cells as 'physaliphorus' cells since they appeared to contain large cytoplasmic vacuoles. However, electron microscopy showed that these apparent vacuoles consist of extracellular matrix surrounded by cells or cell processes. The structure of notochordal cells and their persistence in the nucleus pulposus after fetal life suggest that they may have a significant role in the formation and maintenance of the nucleus pulposus.
TL;DR: A role for recently identified 1-(3'-O-acyl)-beta-D-glucosyl-N-(omega-hydroxyacyl)sphingosines in the epidermis of terrestrial vertebrates could explain the effects of essential fatty acid deficiency, in which the lamellar granules fail to assemble and the barrier to water diffusion is lost.
Abstract: In the epidermis of terrestrial vertebrates, lipid lamellae between the horny cells are thought to form a barrier to water loss. The lipids are extruded from living cells after assembly in lamellar granules. This assembly might be promoted by recently identified 1-(3'-O-acyl)-beta-D-glucosyl-N-(omega-hydroxyacyl)sphingosines, which have 30- and 32-carbon hydroxy acids as amides and linoleic acid esterified to glucose. Such a role for these molecules could explain the effects of essential fatty acid deficiency, in which the lamellar granules fail to assemble and the barrier to water diffusion is lost.
TL;DR: This review focuses on the more significant contributions to the understanding and use of ion-selective electrodes (ISE's) and illustrates examples of the general trends and directions of ISE interests.
Abstract: This review focuses on the more significant contributions to the understanding and use of ion-selective electrodes (ISE's). There is a strong interest in this field as over 1400 articles and abstracts were found during the writing of this review which covers the period from January 1986 through December 1987. The major analytical and electrochemical journals were read and a hand search of Chemical Abstracts uncovered the remaining articles. Unlike previous fundamental reviews, this paper will not attempt to list all the pertinent papers on ISE's. Rather, the more interesting works and applications are covered to illustrate examples of the general trends and directions of ISE interests.