Showing papers by "University of Missouri published in 1995"

The Effects of Perceived Interdependence on Dealer Attitudes

Abstract: Channels research has consistently argued that asymmetric channel relationships are more dysfunctional than those characterized by symmetric interdependence. The authors propose that the degree of ...

Stochastic resonance and the benefits of noise: from ice ages to crayfish and SQUIDs

Abstract: Noise in dynamical systems is usually considered a nuisance. But in certain nonlinear systems, including electronic circuits and biological sensory apparatus, the presence of noise can in fact enhance the detection of weak signals. This phenomenon, called stochastic resonance, may find useful application in physical, technological and biomedical contexts.

Regional Forest Fragmentation and the Nesting Success of Migratory Birds

Abstract: Forest fragmentation, the disruption in the continuity of forest habitat, is hypothesized to be a major cause of population decline for some species of forest birds because fragmentation reduces nesting (reproductive) success Nest predation and parasitism by cowbirds increased with forest fragmentation in nine midwestern (United States) landscapes that varied from 6 to 95 percent forest cover within a 10-kilometer radius of the study areas Observed reproductive rates were low enough for some species in the most fragmented landscapes to suggest that their populations are sinks that depend for perpetuation on immigration from reproductive source populations in landscapes with more extensive forest cover Conservation strategies should consider preservation and restoration of large, unfragmented "core" areas in each region

The Effects of Supplier Fairness On Vulnerable Resellers

Abstract: This study examines the role of supplier fairness in developing long-term relationships between relatively smaller, vulnerable resellers and larger, powerful suppliers. The authors conceptualize two components of fairness-distributive fairness, that is, the fairness of outcomes received by the reseller from carrying the supplier's line, and procedural fairness, the fairness of procedures and processes used by the supplier in relation to its resellers. Testing their hypotheses from the perspective of automobile dealers, the authors find strong evidence that vulnerable resellers' perceptions of both distributive and procedural fairness enhance their relationship quality, although these effects are moderated by the level of outcomes and environmental uncertainty. Furthermore, procedural fairness has relatively stronger effects on relationship quality than distributive fairness, which is a somewhat surprising result from a managerial perspective. The constructs and relationships among the constructs demonstrate cross-national stability across the two countries in the sample, the United States and the Netherlands.

Seeking the Ideal Form: Product Design and Consumer Response:

Abstract: The physical form or design of a product is an unquestioned determinant of its marketplace success. A good design attracts consumers to a product, communicates to them, and adds value to the produc...

Tests of Glycemia in Diabetes

Abstract: Monitoring of glycemic status, as performed by patients and health care providers, is considered a cornerstone of diabetes care. Results of monitoring are used to assess the efficacy of therapy and to make adjustments in diet, exercise, and medications in order to achieve the best possible blood glucose control. The purpose of this review is to summarize current knowledge about the tests used most widely in monitoring the glycemic status of people with diabetes. The review addresses both patient- and physician/laboratory-based testing, and it includes tests of urine glucose and ketones and tests of blood glucose and glycated proteins (hemoglobin and serum proteins). The major emphasis is on the advantages and limitations of each test for routine clinical practice. Use of these tests for diabetes screening and diagnosis will not be addressed in this review. Since this review was first published in 1995, there have been many advances in the field, most notably standardization of glycated hemoglobin testing and new approaches to self-monitoring of blood glucose (SMBG), including minimally invasive continuous glucose monitoring over hours to days at a time. These and other advances are presented in detail in a recent report that was prepared by the National Academy of Clinical Biochemistry (NACB) and published as an American Diabetes Association (ADA) position statement (1). This review will attempt to complement, rather than duplicate, the material in the NACB report. If there was an ideal method of monitoring glycemic status, it might be a small noninvasive device, perhaps similar to a wristwatch that people with diabetes could wear to continuously monitor their blood glucose level. The device would warn of impending hypoglycemia. It also would store blood glucose data and perform a variety of calculations such as hourly, daily, weekly, or monthly blood glucose averages. Unfortunately, such a monitoring device is …

The Future of U.S. Agricultural Cooperatives: A Neo-Institutional Approach

Abstract: Thirty years ago Helmberger speculated that industrialization of agriculture would lead to the demise of farmer cooperatives (Helmberger 1966, p. 1434). In responding to Helmberger's prediction, Abrahamsen countered by suggesting that as industrialization of agriculture evolved, cooperatives would increasingly become the "farmer's integrating agency" (Abrahamsen, p. 1442). In this paper I examine these two divergent opinions by (a) briefly describing the structural and strategic evolution of U.S. farmer cooperatives since the Helmberger and Abrahamsen (H&A) forecasts, (b) utilizing recent developments in neo-institutional economic (organizational economic) theory to generate hypotheses regarding structural and strategic shifts in U.S. agricultural cooperatives, and (c) further applying neo-institutional economics to speculate what the future might hold for U.S. producerowned and -controlled agricultural cooperatives.

Multisystemic treatment of serious juvenile offenders: Long-term prevention of criminality and violence

Abstract: This article examined the long-term effects of multisystemic therapy (MST) vs. individual therapy (IT) on the prevention of criminal behavior and violent offending among 176 juvenile offenders at high risk for committing additional serious crimes. Results from multiagent, multimethod assessment batteries conducted before and after treatment showed that MST was more effective than IT in improving key family correlates of antisocial behavior and in ameliorating adjustment problems in individual family members. Moreover, results from a 4-year follow-up of rearrest data showed that MST was more effective than IT in preventing future criminal behavior, including violent offending. The implications of such findings for the design of violence prevention programs are discussed.

Genes that regulate both development and longevity in Caenorhabditis elegans.

Abstract: The nematode Caenorhabditis elegans responds to conditions of overcrowding and limited food by arresting development as a dauer larva. Genetic analysis of mutations that alter dauer larva formation (daf mutations) is presented along with an updated genetic pathway for dauer vs. nondauer development. Mutations in the daf-2 and daf-23 genes double adult life span, whereas mutations in four other dauer-constitutive genes positioned in a separate branch of this pathway (daf-1, daf-4, daf-7 and daf-8) do not. The increased life spans are suppressed completely by a daf-16 mutation and partially in a daf-2; daf-18 double mutant. A genetic pathway for determination of adult life span is presented based on the same strains and growth conditions used to characterize Daf phenotypes. Both dauer larva formation and adult life span are affected in daf-2; daf-12 double mutants in an allele-specific manner. Mutations in daf-12 do not extend adult life span, but certain combinations of daf-2 and daf-12 mutant alleles nearly quadruple it. This synergistic effect, which does not equivalently extend the fertile period, is the largest genetic extension of life span yet observed in a metazoan.

Reproductive Success of Migratory Birds in Habitat Sources and Sinks

Abstract: Fragmentation of breeding habitat in North America has been implicated in the decline of forest-nesting, Neotropical migrant birds. We used a comparative approach to examine the effects of fragmentation on three forest-nesting migrants: Ovenbird (Seiurus aurocapillus), Red-eyed Vireo (Vireo ofivaceus), and Wood Thrush (Hylocichla mustelina). We surveyed birds and monitored reproductive success on 28 study plots in fragmented and contiguous forests in two midwestern regions. Distribution of individuals between fragmented and contiguous forests appeared to vary among species and regions, but total nest failure was significantly higher in fragments than contiguous forests in both regions for all species (p = 0.053). We attributed greater nest failure to increased nest predation (p = O. 093) and increased brood parasitism by the Brownheaded Cowbird (Molothrus ater, p = 0. 009). In addition to greater total nest failure, partial nest failure due to cowbird parasitism led to a reduction in the number of host fledglings. Although the causes of nest mortality appeared to be species specific, total nest failure and partial nest failure acted in concert to reduce the number of offspring per adult for all three species on fragments. We used simple population growth models to assess the viabaity of the three species in fragmented and contiguous habitats in both regions. In general, populations on fragments appeared to be population sinks and populations on continguous forests appeared to be population sources. Assuming constant mortality during winter, projected growth indicated that without immigration Ovenbird and Red-eyed Vireo populations should become extinct on fragments in both regions and Wood Thrush populations should be maintained or slightly decline on fragments. Populations of all three species should increase in contiguous habitats in both regions without emigration. We suggest that habitat fragmentation reduces local reproduction and may have ramifications for the entire population. A clear understanding of population demography depends on examination of demographic dynamics within and among sources and sinks. We emphasize that the long-term viability of these species depends on maintaining large tracts of forest throughout the breeding range until the spatial scale at which source and sink populations interact can be determined.

CRIES: a new neonatal postoperative pain measurement score. Initial testing of validity and reliability

Abstract: We have developed a neonatal pain assessment tool CRIES. The tool is a ten point scale similar to the APGAR score (Apgar 1953). It is an acronym of five physiological and behavioural variables previously shown to be associated with neonatal pain. C--Crying; R--Requires increased oxygen administration; I--Increased vital signs; E--Expression; S--Sleeplessness. We have tested CRIES for validity and reliability. This report is the result of that testing. We have found CRIES to be valid, reliable and well accepted by neonatal nurses.

Hot Temperatures, Hostile Affect, Hostile Cognition, and Arousal: Tests of a General Model of Affective Aggression

Abstract: A general model of affective aggression was used to generate predictions concerning hot temperatures. Experiment 1 examined hot temperature effects on hostile affect, hostile cognition, perceived arousal, and physiological arousal in the context of a study of video games. Experiment 2 examined hot temperature effects on hostile affect, perceived and physiological arousal, and general positive and negative affect in the context of brief aerobic exercise. Consistent results were obtained. Hot temperatures produced increases in hostile affect, hostile cognition, and physiological arousal. Hot temperatures also produced decreases in perceived arousal and general positive affect. These results suggest that hot temperatures may increase aggressive tendencies via any of three separate routes. Hostile affect, hostile cognitions, and excitation transfer processes may all increase the likelihood of biased appraisals of ambiguous social events, biased in a hostile direction.

Plant Protein Kinase Families and Signal Transduction

Abstract: Enzymes of the eukaryotic protein kinase superfamily catalyze the reversible transfer of the gamma-phosphate from ATP to amino acid side chains of proteins. Protein kinase function can be counteracted by the action of phosphoprotein phosphatases. Phosphorylation status of a protein can have profound effects on its activity and interaction with other proteins. An estimated 1 to 3% of functional eukaryotic genes encode protein kinases, suggesting that they are involved in many aspects of cellular regulation and metabolism. In plants, protein phosphorylation has been implicated in responses to many signals, including light, pathogen invasion, hormones, temperature stress, and nutrient deprivation. Activities of several plant metabolic and regulatory enzymes are also controlled by reversible phosphorylation. As might be expected from this diversity of function, there is a large array of different protein kinases. Purification of protein kinases and their subsequent cloning, facilitated by the PCR and advances in homology-based cloning techniques, as well as functional analyses, including complementation of conditional yeast mutants and positional cloning of mutant plant genes, has already led to identification of more than 70 plant protein kinase genes. However, the precise functional roles of specific protein kinases and phosphatases during plant growth and development have been elucidated for only a few.

Competitiveness through Management of Diversity: Effects on Stock Price Valuation

Abstract: This study's premise is that firms that can lower their costs and enhance their differentiation through the effective management of their human resources have a competitive advantage. Using data fr...

Expression of follicle-stimulating hormone and luteinizing hormone receptor messenger ribonucleic acids in bovine follicles during the first follicular wave.

Abstract: The objective of the present study was to characterize expression of mRNAs encoding FSH and LH receptors during follicular development and at different stages of the first follicular wave in cattle. Following estrus, groups of heifers (3-5 per group) were ovariectomized on the day of initiation of the first follicular wave (as determined by ultrasonography; Day 0), or on Days 2, 4, 6, 8, or 10 after initiation of the first wave. FSH and LH receptor mRNAs were detected within follicles > or = 4 mm and in some smaller follicles by in situ hybridization and were quantified by image analysis. FSH receptor mRNA was expressed in granulosa cells of all growing follicles, starting in some follicles with only one layer of granulosa cells. Irrespective of day of the follicular wave, the level of expression of FSH receptor mRNA in granulosa cells of healthy antral follicles ranging from 0.5 to 14 mm in diameter did not vary significantly with follicular size (r = 0.02, p > 0.10). Expression of LH receptor mRNA was first observed in theca interna cells of follicles shortly after antral formation. Irrespective of day of the follicular wave, the levels of LH receptor mRNA in theca interna cells of healthy antral follicles ranging from 0.5 to 14 mm increased with follicular size (r = 0.39, p 9 mm in diameter and was first observed in the dominant follicles collected on Day 4. Expression of mRNA for LH receptor, but not for FSH receptor, changed (p < 0.01) with the stage of the first follicular wave.(ABSTRACT TRUNCATED AT 250 WORDS)

Male Gender Role Conflict, Depression, and Help Seeking: Do College Men Face Double Jeopardy?

Abstract: To investigate the previously untested hypothesis that college men with higher levels of male gender role conflict (MGRC) experience both increased risk of depression and more negative attitudes toward seeking counseling services, this study used latent variable modeling to examine these relations. Two components of MGRC were identified: restriction-related MGRC, which predicted 25% of the variance in help-seeking attitudes, and achievement-relatedMGRC, which predicted 21% of the variance in depression. It is suggested that outreach programs designed to increase college men's willingness to use counseling services attempt to counter the option-limiting aspects of male gender roles, whereas counseling with depressed college men incorporate an examination of their perceptions of success and achievement.

Composite structure of auxin response elements.

Abstract: The auxin-responsive soybean GH3 gene promoter is composed of multiple auxin response elements (AuxREs), and each AuxRE contributes incrementally to the strong auxin inducibility to the promoter. Two independent AuxREs of 25 bp (D1) and 32 bp (D4) contain the sequence TGTCTC. Results presented here show that the TGTCTC element in D1 and D4 is required but not sufficient for auxin inducibility in carrot protoplast transient expression assays. Additional nucleotides upstream of TGTCTC are also required for auxin inducibility. These upstream sequences showed constitutive activity and no auxin inducibility when part or all of the TGTCTC element was mutated or deleted. In D1, the constitutive element overlaps the 5' portion of TGTCTC; in D4, the constitutive element is separated from TGTCTC. An 11-bp element in D1, CCTCGTGTCTC, conferred auxin inducibility to a minimal cauliflower mosaic virus 35S promoter in transgenic tobacco seedlings as well as in carrot protoplasts (i.e., transient expression assays). Both constitutive elements bound specifically to plant nuclear proteins, and the constitutive element in D1 bound to a recombinant soybean basic leucine zipper transcription factor with G-box specificity. To demonstrate further the composite nature of AuxREs and the ability of the TGTCTC element to confer auxin inducibility, we created a novel AuxRE by placing a yeast GAL4 DNA binding site adjacent to the TGTCTC element. Expression of a GAL4-c-Rel transactivator in the presence of this novel AuxRE resulted in auxin-inducible expression. Our results indicate that at least some AuxREs have a composite structure consisting of a constitutive element adjacent to a conserved TGTCTC element that confers auxin inducibility.

Reflections of evolution and culture in children's cognition: Implications for mathematical development and instruction.

Abstract: An evolution-based framework for understanding biological and cultural influences on children's cognitive and academic development is presented. The utility of this framework is illustrated within the mathematical domain and serves as a foundation for examining current approaches to educational reform in the United States. Within this framework, there are two general classes of cognitive ability, biologically primary and biologically secondary. Biologically primary cognitive abilities appear to have evolved largely by means of natural or sexual selection. Biologically secondary cognitive abilities reflect the co-optation of primary abilities for purposes other than the original evolution-based function and appear to develop only in specific cultural contexts. A distinction between these classes of ability has important implications for understanding children's cognitive development and achievement.

Similar-shape retrieval in shape data management

Abstract: Addresses the problem of similar-shape retrieval, where shapes or images in a shape database that satisfy specified shape-similarity constraints with respect to the query shape or image must be retrieved from the database. In its simplest form, the similar-shape retrieval problem can be stated as, "retrieve or select all shapes or images that are visually similar to the query shape or the query image's shape". We focus on databases of 2D shapes-or equivalently, databases of images of flat or almost flat objects. (We use the terms "object" and "shape" interchangeably). Two common types of 2D objects are rigid objects, which have a single rigid component called a link, and articulated objects, which have two or more rigid components joined by movable (rotating or sliding) joints. An ideal similar-shape retrieval technique must be general enough to handle images of articulated as well as rigid objects. It must be flexible enough to handle simple query images, which have isolated shapes, and complex query images, which have partially visible, overlapping or touching objects. We discuss the central issues in similar-shape retrieval and explain how these issues are resolved in a shape retrieval scheme called FIBSSR (Feature Index-Based Similar-Shape Retrieval). This new similar-shape retrieval system effectively models real-world applications. >

A structured epidemic model incorporating geographic mobility among regions.

Abstract: A model for the spread of infectious diseases among discrete geographic regions is presented that incorporates a mobility process that describes how contact occurs between individuals from different regions. The general formulation of the mobility process is described, and it is shown that the formulation encapsulates a range of mobility behavior from complete isolation of all regions (no mobility) to permanent migration between regions. It is then shown how this mobility process fits into an SIR epidemic model, and two examples are given extending its use. The examples include a model for disease transmission in a population with two distinct mobility patterns operating and a model developed to describe a 1984 measles epidemic on the Caribbean island of Dominica.

Jump and sharp cusp detection by wavelets

Abstract: SUMMARY A method is proposed to detect jumps and sharp cusps in a function which is observed with noise, by checking if the wavelet transformation of the data has significantly large absolute values across fine scale levels. Asymptotic theory is established and practical implementation is discussed. The method is tested on simulated examples, and applied to stock market return data. The analysis of change-points, which describe sudden localised changes, has recently found increasing interest. Change-points can be used to model practical problems arising in fields such as quality control, economics, medicine, signal and image processing, and physical sciences. For example, in electroencephalogram signals, sharp cusps exhibit the accelerations and decelerations in the beating of the hearts. Many practical problems like this involve functions which have jumps and sharp cusps. The recently developed theory of wavelets has drawn much attention from both math- ematicians, statisticians and engineers. In the seminal work of Donoho (1993), Donoho & Johnstone (1994, 1995a,b) and Donoho, Johnstone et al. (1995), orthonormal bases of compactly supported wavelets have been used to estimate functions. The theory of wavelets permits decomposition of functions into localised oscillating components. This is an ideal tool to study localised changes such as jumps and sharp cusps in one dimension as well as several dimensions. Unlike traditional smoothing methods based on a fixed spatial scale, the wavelet method is a multiresolution approach and has local adaptivity. In this

The cocktail party phenomenon revisited: How frequent are attention shifts to one's name in an irrelevant auditory channel?

Abstract: N. Moray's (1959) well-known study of the "cocktail party phenomenon" suggested that participants sometimes notice their name embedded in an ignored auditory channel. However, the empirical finding was preliminary in nature and never has been directly replicated. This was done with improved methodological controls, and the relationship between on-line attention shifts to one's name and subsequent recollection of the name in a sample of 34 undergraduates was examined. Similar to N. Moray, only 34.6% of the participants recalled hearing their name in the channel to be ignored. Only those participants showed on-line evidence of attention shifts, and those shifts occurred only for the two items following the name. The results suggest that participants who detected their name monitored the irrelevant channel for a short time afterward.

The relationship between self reports of college experiences and achievement test scores

Abstract: This study evaluated the feasibility of using students' self reports of the academic development and college experiences as proxies and policy indicators for a national assessment of undergraduate education. Results indicated that self reports of academic development should be used with care as proxies for a national test. Particularly important are issues of content overlap and differences in the measurement methods. Results from the second part of this study supported using self reports of college experiences as policy indicators to improve undergraduate education.

Tissue-specific regulation of selenoenzyme gene expression during selenium deficiency in rats.

Abstract: Regulation of synthesis of the selenoenzymes cytosolic glutathione peroxidase (GSH-Px), phospholipid hydroperoxide glutathione peroxidase (PHGSH-Px) and type-1 iodothyronine 5'-deiodinase (5'IDI) was investigated in liver, thyroid and heart of rats fed on diets containing 0.405, 0.104 (Se-adequate), 0.052, 0.024 or 0.003 mg of Se/kg. Severe Se deficiency (0.003 mg of Se/kg) caused almost total loss of GSH-Px activity and mRNA in liver and heart. 5'IDI activity decreased by 95% in liver and its mRNA by 50%; in the thyroid, activity increased by 15% and mRNA by 95%. PHGSH-Px activity was reduced by 75% in the liver and 60% in the heart but mRNA levels were unchanged; in the thyroid, PHGSH-Px activity was unaffected by Se depletion but its mRNA increased by 52%. Thus there is differential regulation of the three mRNAs and subsequent protein synthesis within and between organs, suggesting both that mechanisms exist to channel Se for synthesis of a particular enzyme and that there is tissue-specific regulation of selenoenzyme mRNAs. During Se depletion, the levels of selenoenzyme mRNA did not necessarily parallel the changes in enzyme activity, suggesting a distinct mechanism for regulating mRNA levels. Nuclear run-off assays with isolated liver nuclei showed severe Se deficiency to have no effect on transcription of the three genes, suggesting that there is post-transcriptional control of the three selenoenzymes, probably involving regulation of mRNA stability.