Showing papers by "University of Missouri published in 1996"

The Market for Corporate Control and Firm Innovation

Abstract: This research examines an integrated theoretical model that explains how strategies for participating in the market for corporate control (acquisitions and divestitures) affect internal control mec...

The changing basis of performance measurement

Abstract: The objective of performance measurement has changed over the past few decades. Traditional performance measures based on productivity are no longer appropriate or representative of the information needs of today’s competitive global market. Alternative performance systems have been proposed that range from time as the basis of all measures to the integration of a variety of performance measures. Reviews and analyses the limitations of traditional approaches to performance measurement as well as the emerging trends in performance measurement system development. Reveals that the basis of performance measurement is changing and that there are certain characteristics that are necessary in order to produce information that is relevant for improving world‐class manufacturing performance.

The possibilistic C-means algorithm: insights and recommendations

Abstract: Recently, the possibilistic C-means algorithm (PCM) was proposed to address the drawbacks associated with the constrained memberships used in algorithms such as the fuzzy C-means (FCM). In this issue, Barni et al. (1996) report a difficulty they faced while applying the PCM, and note that it exhibits an undesirable tendency to converge to coincidental clusters. The purpose of this paper is not just to address the issues raised by Barni et al., but to go further and analytically examines the underlying principles of the PCM and the possibilistic approach, in general. We analyze the data sets used by Barni et al. and interpret the results reported by them in the light of our findings.

The current state of empathy research

Abstract: The literature on empathy, primarily from counseling and psychotherapy and secondarily from social and developmental psychology, is reviewed. Obstacles that may account for theoretical confusions and empirical difficulties in studying empathy are highlighted. The decrease in empathy research in recent years appears attributable to the lack of clear focus and effective research tools as well as the shift in interest from empathy to other concepts such as the working alliance. It is argued that there is a need to return to studying empathy. Researchers should distinguish between dispositional and experiential empathy and between intellectual empathy and empathic emotions and indicate whether they are examining therapist or client experience of empathy. Suggestions for future research are offered.

Decreased resistance to bacterial infection and granulocyte defects in IAP-deficient mice

Abstract: Granulocyte [polymorphonuclear leucocyte (PMN)] migration to sites of infection and subsequent activation is essential for host defense. Gene-targeted mice deficient for integrin-associated protein (IAP, also termed CD47) succumbed to Escherichia coli peritonitis at inoccula survived by heterozygous littermates. In vivo, they had an early defect in PMN accumulation at the site of infection. In vitro, IAP-/- PMNs were deficient in beta3 integrin-dependent ligand binding, activation of an oxidative burst, and Fc receptor-mediated phagocytosis. Thus, IAP plays a key role in host defense by participating both in PMN migration in response to bacterial infection and in PMN activation at extravascular sites.

Control of C. elegans Larval Development by Neuronal Expression of a TGF-β Homolog

Abstract: The Caenorhabditis elegans dauer larva is specialized for dispersal without growth and is formed under conditions of overcrowding and limited food. The daf-7 gene, required for transducing environmental cues that support continuous development with plentiful food, encodes a transforming growth factor-β (TGF-β) superfamily member. A daf-7 reporter construct is expressed in the ASI chemosensory neurons. Dauer-inducing pheromone inhibits daf-7 expression and promotes dauer formation, whereas food reactivates daf-7 expression and promotes recovery from the dauer state. When the food/pheromone ratio is high, the level of daf-7 mRNA peaks during the L1 larval stage, when commitment to non-dauer development is made.

Impact of corporate insider, blockholder, and institutional equity ownership on firm risk taking

Abstract: The nature of a firm's risk-taking behavior can significantly affect corporate performance. In an agency context, we examined the influence of equity ownership structure upon corporate risk taking....

Effects of preexisiting beliefs, epistemological beliefs, and need for cognition on interpretation of controversial issues.

Abstract: This study examined the influence of people's beliefs about the certainty of knowledge, the strength of their beliefs about a controversial issue, and their tendency to enjoy effortful thinking on their interpretation of controversial information. Ninety-six undergraduates completed an epistemological beliefs questionnaire (M. Schommer, 1990), the Need for Cognition Scale (J. T. Cacioppo, R. E. Petty, & C. F. Kao, 1984), and indicated the degree to which they believed that HIV causes AIDS. They then read a text that presented two conflicting views regarding the HIV-AIDS relationship and wrote a concluding paragraph for the text. Regression analyses revealed that the less students believed in certain knowledge, the less extreme their initial beliefs, and the higher their need for cognition, the more likely they were to write conclusions that reflected the inconclusive nature of the mixed evidence they read.

Current-Dependent Exchange-Correlation Potential for Dynamical Linear Response Theory.

Abstract: The frequency-dependent exchange-correlation potential, which appears in the usual Kohn-Sham formulation of a time-dependent linear response problem, is a strongly nonlocal functional of the density, so that a consistent local density approximation generally does not exist. This problem can be avoided by choosing the current density as the basic variable in a generalized Kohn-Sham theory. This theory admits a local approximation which, for fixed frequency, is exact in the limit of slowly varying densities and perturbing potentials.

CHAPTER 9 – Structure and Dynamics of an Amphibian Community: Evidence from a 16-Year Study of a Natural Pond

Abstract: This chapter describes a 16-year study, in which it has been found that pond hydroperiod is a primary source of variation in community structure for a natural community of pond-breeding amphibians. Larval competition and predation form other axes that are positioned along a continuum of hydroperiod, and the strength of their influence on the success of species is mediated by pond hydroperiod. Although hydroperiod, competition, and predation had a detectable influence on the amphibian community at Rainbow Bay, the effects of these factors were often difficult to separate. Correlative analyses are less powerful for sorting out confounding factors than manipulative experiments in replicated artificial ponds. The predictor variables used are often themselves correlated. Nevertheless, in many cases, a good year for a species is also a good year for its competitors and predators. Juvenile recruitment of all species is limited by a short hydroperiod in the driest years. In years with longer hydroperiods, the density of competitors affected the number of metamorphosing juveniles per breeding females for some species. The density of salamander larvae is also a significant predictor of per-capita juvenile recruitment for anurans. A significant negative relationship is detected for two of four anuran species analyzed, most likely due to predation by the salamander larvae on the anuran tadpoles. These results indicate that community structure, at least in terms of relative abundances, varied continuously. However, regulation of community structure within a pond occurs through the predictable interaction of rainfall, hydroperiod, competition, and predation.

Skewness and kurtosis in s&p 500 index returns implied by option prices

Abstract: The Black-Scholes (1973) model frequently misprices deep-in-the-money and deep-out-of-the-money options. Practitioners popularly refer to these strike price biases as volatility smiles. In this paper we examine a method to extend the Black-Scholes model to account for biases induced by nonnormal skewness and kurtosis in stock return distributions. The method adapts a Gram-Charlier series expansion of the normal density function to provide skewness and kurtosis adjustment terms for the Black-Scholes formula. Using this method, we estimate option-implied coefficients of skewness and kurtosis in S&P 500 stock index returns. We find significant nonnormal skewness and kurtosis implied by option prices.

Sexual selection and sex differences in mathematical abilities.

Abstract: The principles of sexual selection were used as an organizing framework for interpreting cross-national patterns of sex differences in mathematical abilities. Cross-national studies suggest that there are no sex differences in biologically primary mathematical abilities, that is, for those mathematical abilities that are found in all cultures as well as in nonhuman primates, and show moderate heritability estimates. Sex differences in several biologically secondary mathematical domains (i.e., those that emerge primarily in school) are found throughout the industrialized world. In particular, males consistently outperform females in the solving of mathematical word problems and geometry. Sexual selection and any associated proximate mechanisms (e.g., sex hormones) influence these sex differences in mathematical performance indirectly. First, sexual selection resulted in greater elaboration in males than in females of the neurocognitive systems that support navigation in three-dimensional space. Knowledge implicit in these systems reflects an understanding of basic Euclidean geometry, and may thus be one source of the male advantage in geometry. Males also use more readily than females these spatial systems in problem-solving situations, which provides them with an advantage in solving word problems and geometry. In addition, sex differences in social styles and interests, which also appear to be related in part to sexual selection, result in sex differences in engagement iii mathematics-related activities, thus further increasing the male advantage in certain mathematical domains. A model that integrates these biological influences with sociocultural influences on the sex differences in mathematical performance is presented in this article.

Electronic structure of the perovskite oxides: La1-xCaxMnO3.

Abstract: The electronic structures of the perovskite oxides, ${\mathrm{LaMnO}}_{3}$ and ${\mathrm{CaMnO}}_{3}$, are studied using density-functional methods. Antiferromagnetic insulating (AFI) solutions are obtained for both compounds within the local-density approximation (LDA). For ${\mathrm{LaMnO}}_{3}$ the Jahn-Teller distortion, found necessary for the AFI solution, produces occupied $\mathrm{Mn}({z}^{2}\ensuremath{-}1)$ orbitals pointed along the long, basal-plane Mn-O bonds. The large on-site Coulomb $U$ and exchange $J$, obtained from ``constrained'' LDA calculations, $U\ensuremath{\approx}8--10\mathrm{eV}$ and $J\ensuremath{\approx}0.9\mathrm{eV}$, indicate important correlation effects and yield large redistribution of the spectral weight within the $\mathrm{LDA}+U$ approach.

Dosage effects on gene expression in a maize ploidy series.

Abstract: Previous studies on gene expression in aneuploids revealed numerous trans-acting dosage effects. Segmental aneuploidy of each varied chromosomal region exhibited predominantly inverse effects on several target genes. Here, dosage regulation was examined in a maize (Zea mays L.) ploidy series where the complete genomic complement is varied. Total RNA from leaf tissue of monoploid, diploid, triploid, and tetraploid plants (1x, 2x, 3x, and 4x, respectively) was analyzed for the expression of 18 genes. For most tested genes, the transcript level per cell is directly proportional to structural gene dosage; that is, on a per genome basis, there is approximately equal expression among the four ploidies. Exceptional cases show a negative correlation of expression with ploidy or a positive correlation greater than expected from the structural gene dosage. These studies suggest that, in general, as structural gene dosage increases in multiples of the monoploid complement, the absolute level of gene expression per cell increases. In contrast, addition or subtraction of only a single chromosome arm tends to alter gene expression patterns extensively. The combined results of the euploid and aneuploid studies suggest that aneuploid effects result from an altered stoichiometry of the factors contributing to the mechanisms of gene expression.

Investigation of fundamental EMI source mechanisms driving common-mode radiation from printed circuit boards with attached cables

Abstract: Fundamental EMI source mechanisms leading to common-mode radiation from printed circuit boards with attached cables are presented in this paper. Two primary EMI source mechanisms have been identified: one associated with a differential-mode voltage and another associated with a differential-mode current, both of which result in a common-mode current on an attached cable. These mechanisms can he used to relate printed circuit layout geometries to EMI sources. The two mechanisms are demonstrated through numerical and experimental results, and an example from a production printed-circuit design is presented.

Multiple Potential Germ-Line Helicases Are Components of the Germ-Line-Specific P Granules of Caenorhabditis Elegans

Abstract: Two components of the germ-line-specific P granules of the nematode Caenorhabditis elegans have been identified using polyclonal antibodies specific for each. Both components are putative germ-line RNA helicases (GLHs) that contain CCHC zinc fingers of the type found in the RNA-binding nucleocapsid proteins of retroviruses. The predicted GLH-1 protein has four CCHC fingers; GLH-2 has six. Both GLH proteins localize in the P granules at all stages of germ-line development. However, the two glh genes display different patterns of RNA and protein accumulation in the germ lines of hermaphrodites and males. Injection of antisense glh-1 or glh-2 RNA into wild-type worms causes some offspring to develop into sterile adults, suggesting that either or both genes are required for normal germ-line development. As these very similar glh genes physically map within several hundred kilobases of one another, it seems likely that they represent a fairly recent gene duplication event.

Examining an affective aggression framework weapon and temperature effects on aggressive thoughts, affect, and attitudes

Abstract: A general framework for studying affective aggression, integrating many insights from previous models (e.g., those of Baron, Berkowitz, Geen, and Zillmann), is presented. New research examining effects of extreme temperatures and photos of guns on arousal, cognition, and affect is reported. Hostile cognition was assessed using an automatic priming task (i.e., Stroop interference). Hostile affect was assessed with the State Hostility Scale. Positive and negative affect, hostile attitudes, perceived comfort, and perceived arousal were also assessed. As expected, hot and cold temperatures increased state hostility and hostile attitudes, and viewing guns did not. As expected, viewing guns primed hostile cognitions and extreme temperatures did not. Theoretical implications of these results and societal implications of the general framework are discussed.

Development of arithmetical competencies in Chinese and American children: influence of age, language, and schooling.

Abstract: The arithmetical competencies of more than 200 Chinese or American kindergarten, first-, second-, or third-grade children were assessed toward the beginning and toward the end of the U.S. school year. All children were administered a paper-and-pencil test of addition skills, a digit span measure, and an addition strategy assessment. The addition strategy assessment provided information on the types of strategies the children used to solve simple addition problems as well as information on the speed and accuracy of their strategy use. Information on the number of math instruction periods across times of measurement was also obtained for each of the first-, second-, and third-grade children. The pattern of arithmetical development across the academic year and across the Chinese and American children suggests that a mix of cultural and maturational factors influence the emergence of early arithmetical competencies and that the Chinese advantage in early mathematical development is related to a combination of language- and school-related factors.

Heat tolerance in two tropically adapted Bos taurus breeds, Senepol and Romosinuano, compared with Brahman, Angus, and Hereford cattle in Florida.

Abstract: Two trials were conducted with heifers to determine heat tolerance among temperate Bos taurus (Angus, Hereford), Bos indicus (Brahman), tropical Bos taurus (Senepol, Romosinuano), and the reciprocal crosses of Hereford and Senepol. Differences among breeds in temperament score, circulating concentrations of cortisol, and blood packed cell volume were also investigated. Trial 1 used 43 Angus, 28 Brahman, 12 Hereford, 23 Romosinuano, 16 Senepol, 5 Hereford x Senepol (H x S), and 5 Senepol x Hereford (S x H) heifers. Trial 2 used 36 Angus, 31 Brahman, 9 Hereford, 14 Senepol, 19 H x S, and 10 S x H heifers. On the hottest summer date in Trial 1, rectal temperature of Angus was greater (P < .001) than that of Brahman, Senepol, or Romosinuano. Rectal temperature and plasma cortisol were significantly less in Senepol than in Brahman, suggesting that the differences in rectal temperature between these breeds may be due to differences in stress response possibly related to differences in temperament. Reciprocal crosses of Hereford and Senepol had rectal temperatures nearly as low as that of Senepol and displayed substantial heterosis (-9.4%, P < .05) in log10 rectal temperature on the hottest summer date. On both the hottest and coolest dates in Trial 1, Angus heifers had significantly faster respiration rates than Brahman, Romosinuano, or Senepol heifers, and Brahman had significantly slower respiration rates than Romosinuano or Senepol. On the hottest summer date in Trial 2, rectal temperature in Angus heifers was greater (P < .001) than in Brahman or Senepol had rectal temperatures similar to that of Senepol, or heterosis for log10 rectal temperature was similar to that in Trial 1 (-9.8%, P < .05). Considering rank order among breeds, Brahman always had the slowest respiration rate and greatest packed cell volume. Brahman had significantly greater temperament scores and plasma cortisol concentrations than Angus or Senepol, except that plasma cortisol was not different between Brahman and Senepol on the hottest summer date. On this date, rectal temperature did not differ between Brahman and Senepol, which supports the hypothesis that there is a relationship between response to stress and rectal temperature that helps explain differences in rectal temperature between Brahman and Senepol. The results of these trials demonstrate heat tolerance of the Senepol and Romosinuano, two Bos taurus breeds. Furthermore, the results suggest a substantial level of dominance of the Senepol's ability to maintain constant body temperature in a hot environment as measured by rectal temperature in crosses with a non-adapted breed.

Growth Maintenance of the Maize Primary Root at Low Water Potentials Involves Increases in Cell-Wall Extension Properties, Expansin Activity, and Wall Susceptibility to Expansins

Abstract: Previous work on the growth biophysics of maize (Zea mays L.) primary roots suggested that cell walls in the apical 5 mm of the elongation zone increased their yielding ability as an adaptive response to low turgor and water potential (psi w). To test this hypothesis more directly, we measured the acid-induced extension of isolated walls from roots grown at high (-0.03 MPa) or low (-1.6 MPa) psi w using an extensometer. Acid-induced extension was greatly increased in the apical 5 mm and was largely eliminated in the 5- to 10-mm region of roots grown at low psi w. This pattern is consistent with the maintenance of elongation toward the apex and the shortening of the elongation zone in these roots. Wall proteins extracted from the elongation zone possessed expansin activity, which increased substantially in roots grown at low psi w. Western blots likewise indicated higher expansin abundance in the roots at low psi w. Additionally, the susceptibility of walls to expansin action was higher in the apical 5 mm of roots at low psi w than in roots at high psi w. The basal region of the elongation zone (5-10 mm) did not extend in response to expansins, indicating that loss of susceptibility to expansins was associated with growth cessation in this region. Our results indicate that both the increase in expansin activity and the increase in cell-wall susceptibility to expansins play a role in enhancing cell-wall yielding and, therefore, in maintaining elongation in the apical region of maize primary roots at low psi w.

The clinical value of computerized information services : a review of 98 randomized clinical trials

Abstract: Objective To review all randomized clinical trials addressing the efficacy of clinical information systems and to determine the clinical settings, types of interventions, and effects studied. Data sources Extensive and systematic MEDLINE searches were conducted using a combination of medical subject headings (MeSH) and textword terms to collect trial reports. Manual searches of books and monographs as well as informal contacts were also used. Study selection The eligibility criteria were (1) randomized controlled clinical trial, (2) computerized information intervention in the study group, and (3) effect measured on the process or outcome of care. Data extraction Two research assistants independently abstracted from the selected reports the following structured information: trial sites, computerized interventions, effect variables, and outcomes. Three investigators evaluated the combined list of trial features for setting, intervention, and effect. The statistical analysis included an evaluation of agreement in developing classifications and an analysis of the ratio of positive trial outcomes. Data synthesis Most information services were tested in outpatient care (82%), particularly in primary care (66%). The information intervention targeted the provider in 64% of the trials. The effect was primarily measured for the process of care (76%). Provider prompt/reminder, computer-assisted treatment planner, interactive patient education/therapy, and patient prompt/reminder were significantly successful interventions (sign test, P Conclusions Randomized clinical trials confirm that four generic information interventions are active ingredients of computer systems and can make a significant difference in family medicine (physician and patient reminders, treatment planner, and patient education). To manage care and improve quality, primary care computer systems should incorporate these effective information services.

Longevity in Caenorhabditis elegans reduced by mating but not gamete production

Abstract: THEORIES of life-history evolution propose that trade-offs occur between fitness components, including longevity and maximal reproduction1–3. In Drosophila, female lifespan is shortened by increased egg production4, receipt of male accessory fluid5 and courting6. Male lifespan is also reduced by courting and/or mating7. Here we show that in the nematode Caenorhabditis elegans, mating with males reduces the lifespan of hermaphrodites by a mechanism independent of egg production or receipt of sperm. Conversely, males appear unaffected by mating. Thus, in C. elegans there is no apparent trade-off between longevity and increased egg or sperm production, but there is a substantial cost to hermaphrodites associated with copulation.