Showing papers by "University of Tennessee published in 1997"

Customer value: The next source for competitive advantage

Abstract: Driven by more demanding customers, global competition, and slow-growth economies and industries, many organizations search for new ways to achieve and retain a competitive advantage. Past attempts have largely looked internally within the organization for improvement, such as reflected by quality management, reengineering, downsizing, and restructuring. The next major source for competitive advantage likely will come from more outward orientation toward customers, as indicated by the many calls for organizations to compete on superior customer value delivery. Although the reasons for these calls are sound, what are the implications for managing organizations in the next decade and beyond? This article addresses this question. It presents frameworks for thinking about customer value, customer value learning, and the related skills that managers will need to create and implement superior customer value strategies.

Teacher and classroom context effects on student achievement: Implications for teacher evaluation.

Abstract: The Tennessee Value-Added Assessment System (TVAAS) has been designed to use statistical mixed-model methodologies to conduct multivariate, longitudinal analyses of student achievement to make estimates of school, class size, teacher, and other effects. This study examined the relative magnitude of teacher effects on student achievement while simultaneously considering the influences of intraclassroom heterogeneity, student achievement level, and class size on academic growth. The results show that teacher effects are dominant factors affecting student academic gain and that the classroom context variables of heterogeneity among students and class sizes have relatively little influence on academic gain. Thus, a major conclusion is that teachers make a difference. Implications of the findings for teacher evaluation and future research are discussed.

Oncogenic Transcription Factors in the Human Acute Leukemias

Abstract: Chromosomal translocations in the human acute leukemias rearrange the regulatory and coding regions of a variety of transcription factor genes. The resultant protein products can interfere with regulatory cascades that control the growth, differentiation, and survival of normal blood cell precursors. Support for this interpretation comes from the results of gene manipulation studies in mice, as well as the sequence homology of oncogenic transcription factors with proteins known to regulate embryonic development in primitive organisms, including the nematode Caenorhabditis elegans and the fruit fly Drosophila melanogaster. Many of these genetic alterations have important prognostic implications that can guide the selection of therapy. The insights gained from studies of translocation-generated oncogenes and their protein products should hasten the development of highly specific, and hence less toxic, forms of leukemia therapy.

Graded Response Model

Abstract: The graded response model represents a family of mathematical models that deals with ordered polytomous categories. These ordered categories include rating such as letter grading, A, B, C, D, and F, used in the evaluation of students’ performance; strongly disagree, disagree, agree, and strongly agree, used in attitude surveys; or partial credit given in accordance with an examinee’s degree of attainment in solving a problem.

Extinction Vulnerability and Selectivity: Combining Ecological and Paleontological Views

Abstract: ▪ Abstract Extinction is rarely random across ecological and geological time scales. Traits that make some species more extinction-prone include individual traits, such as body size, and abundance. Substantial consistency appears across ecological and geological time scales in such traits. Evolutionary branching produces phylogenetic (as often measured by taxonomic) nesting of extinction-biasing traits at many scales. An example is the tendency, seen in both fossil and modern data, for higher taxa living in marine habitats to have generally lower species extinction rates. At lower taxononomic levels, recent bird and mammal extinctions are concentrated in certain genera and families. A fundamental result of such selectivity is that it can accelerate net loss of biodiversity compared to random loss of species among taxa. Replacement of vulnerable taxa by rapidly spreading taxa that thrive in human-altered environments will ultimately produce a spatially more homogenized biosphere with much lower net diversity.

Evidence for Life in a Martian Meteorite

Abstract: The controversial hypothesis that the ALH84001 meteorite contains relics of ancient martian life has spurred new findings, but the question has not yet been resolved. Organic matter probably results, at least in part, from terrestrial contamination by Antarctic ice meltwater. The origin of nanophase magnetites and sulfides, suggested, on the basis of their sizes and morphologies, to be biogenic remains contested, as does the formation temperature of the carbonates that contain all of the cited evidence for life. The reported nonfossils may be magnetite whiskers and platelets, probably grown from a vapor. New observations, such as the possible presence of biofilms and shock metamorphic effects in the carbonates, have not yet been evaluated. Regardless of the ultimate conclusion, this controversy continues to help define strategies and sharpen tools that will be required for a Mars exploration program focused on the search for life.

Exploratory and confirmatory factor analysis: guidelines, issues, and alternatives

Abstract: AMY E. HURLEY, TERRI A. SCANDURA, CHESTER A. SCHRIESHEIM, MICHAEL T. BRANNICK, ANSON SEERS, ROBERT J. VANDENBERG AND LARRY J. WILLIAMS Department of Professional Studies, Chapman University, U.S.A. Department of Management, University of Miami, U.S.A. Department of Psychology, University of South Florida, U.S.A. Department of Management, Virginia Commonwealth University, U.S.A. Department of Management, The University of Georgia, U.S.A. Department of Management, University of Tennessee, U.S.A.

Top500 Supercomputer Sites

Abstract: To provide a better basis for statistics on high-performance computers, we list the sites that have the 500 most powerful computer systems installed. The best Linpack benchmark performance achieved is used as a performance measure in ranking the computers.

Prospective study of blunt aortic injury: Multicenter trial of the American Association for the Surgery of Trauma

Abstract: Background: Blunt aortic injury is a major cause of death from blunt trauma. Evolution of diagnostic techniques and methods of operative repair have altered the management and posed new questions in recent years. Methods: This study was a prospectively conducted multicenter trial involving 50 trauma centers in North America under the direction of the Multi-institutional Trial Committee of the American Association for the Surgery of Trauma. Results: There were 274 blunt aortic injury cases studied over 2.5 years, of which 81% were caused by automobile crashes. Chest computed tomography and transesophageal echocardiography were applied in 88 and 30 cases, respectively, and were 75 and 80% diagnostic, respectively. Two hundred seven stable patients underwent planned thoracotomy and repair. Clamp and sew technique was used in 73 (35%) and bypass techniques in 134 (65%). Overall mortality was 31%, with 63% of deaths being attributable to aortic rupture; mortality was not affected by method of repair. Paraplegia occurred postoperatively in 8.7%. Logistic regression analysis demonstrated clamp and sew (p = 0.002) and aortic cross clamp time of 30 minutes (p = 0.01) to be associated with development of postoperative paraplegia. Conclusions: Rupture after hospital admission remains a major problem. Although newer diagnostic techniques are being applied, at this time aortography remains the diagnostic standard. Aortic cross clamp time beyond 30 minutes was associated with paraplegia; bypass techniques, which provide distal aortic perfusion, produced significantly lower paraplegia rates than the clamp and sew approach.

A tutorial on Reed-Solomon coding for fault-tolerance in RAID-like systems

Abstract: SUMMARY It is well-known that Reed-Solomon codes may be used to provide error correction for multiple failures in RAID-like systems. The coding technique itself, however, is not as well-known. To the coding theorist, this technique is a straightforward extension to a basic coding paradigm and needs no special mention. However, to the systems programmer with no training in coding theory, the technique may be a mystery. Currently, there are no references that describe how to perform this coding that do not assume that the reader is already well-versed in algebra and coding theory. This paper is intended for the systems programmer. It presents a complete specification of the coding algorithm plus details on how it may be implemented. This specification assumes no prior knowledge of algebra or coding theory. The goal of this paper is for a systems programmer to be able to implement Reed-Solomon coding for reliability in RAID-like systems without needing to consult any external references. ©1997 by John Wiley & Sons, Ltd.

Positron Production in Multiphoton Light-by-Light Scattering

Abstract: A signal of 106 {+-} 14 positrons above background has been observed in collisions of a low-emittance 46.6-GeV electron beam with terawatt pulses from a Nd:glass laser at 527 nm wavelength in an experiment at the Final Focus Test Beam at SLAC. Peak laser intensities of {approximately} 1.3 {times} 10{sup 18} W/cm{sup 2} have been achieved corresponding to a value of 0.3 for the parameter {Upsilon} = {var_epsilon}*/{var_epsilon}{sub crit} where {var_epsilon}* = 2{gamma}{var_epsilon}{sub lab} is the electric field strength of the laser transformed to the rest frame of the electron beam and {var_epsilon}{sub crit} = m{sup 2}c{sup 3}/e{bar h} = 1.3 {times} 10{sup 16} V/cm is the QED critical field strength. The positrons are interpreted as arising from a two-step process in which laser photons are backscattered to GeV energies by the electron beam followed by a collision between the high-energy photon and several laser photons to produce an electron-positron pair. These results are the first laboratory evidence for a light-by-light scattering process involving only real photons.

Optimal control of the chemotherapy of HIV.

Abstract: Using an existing ordinary differential equation model which describes the interaction of the immune system with the human immunodeficiency virus (HIV), we introduce chemotherapy in an early treatment setting through a dynamic treatment and then solve for an optimal chemotherapy strategy. The control represents the percentage of effect the chemotherapy has on the viral production. Using an objective function based on a combination of maximizing benefit based on T cell counts and minimizing the systemic cost of chemotherapy (based on high drug dose/strength), we solve for the optimal control in the optimality system composed of four ordinary differential equations and four adjoint ordinary differential equations.

The Phenomenology of Everyday Life: Empirical Investigations of Human Experience

Abstract: The Phenomenology of Everyday Life presents results from a rigorous qualitative approach to the psychological study of everyday human activities and experiences. This book does not replace scientific observation with humanistic analysis, but provides an additional perspective on significant human questions. The qualitative approach this book employs is grounded in the philosophical traditions of existentialism and phenomenology, which use dialogue as their major method of inquiry. These traditions are especially well adapted to encompass and describe human events and activities. In addition, such events can be properly investigated only on the basis of a method sensitive enough to articulate the nuances of human experience and reflection. In this latter regard, it is important to note that insights deriving from literature and the humanities are equally revealing of the human world as those from experimental psychology, biology or medicine.

The social consequences of self-control: testing the general theory of crime*

Abstract: Gottfredson and Hirschi's recently introduced general theory of crime has received considerable empirical support. Researchers have found that low self-control, the general theory's core concept, is related to lawbreaking and to deviant behaviors considered by Gottfredson and Hirschi to be “analogous” to crime. In this article, we extend this research by assessing the effects of low self-control on crime and analogous behaviors and by using two distinct measures of self-control, an attitudinal measure and the analogous/behavior scale. Thus, following Gottfredson and Hirschi, we use analogous imprudent behaviors as outcomes of low self-control and as indicators of low self-control's effects on crime. We also examine an important but thus far neglected part of the theory: the claim that low self-control has effects not only on crime but also on life chances, life quality, and other social consequences. Consistent with the general theory, we found that both measures of self-control, attitudinal and behavioral, have effects on crime, even when controlling for a range of social factors. Further, the analysis revealed general support for the theory's prediction of negative relationships between low self-control and social consequences other than crime—life outcomes and quality of life.

Collectivistic orientation in teams: an individual and group-level analysis

Abstract: With the increasing use of work teams in U.S. industry, understanding team members' collectivistic orientation toward group goals and activities is critical for developing cooperative and productive teams. Using the research on expectancy theory, self-efficacy, locus of control, and individualism–collectivism, collectivism is examined as both an individual difference variable and a group composition variable. One hundred and forty-eight individuals (comprising 33 groups) working on a complex and interdependent task comprised the research sample. Results indicated that individual difference variables of self-efficacy for teamwork, need for social approval, and positive past experience working in teams were related to self-report collectivism. Additionally, team collectivistic orientation was examined as a group composition variable and found to be related to cooperative team behaviors. In turn, these cooperative team behaviors acted as a mediator of the relationship between team collectivistic orientation and team performance. Results are discussed in terms of theory building and applied research. © 1997 John Wiley & Sons, Ltd.

Measuring physical distribution service quality

Abstract: The quality of the physical distribution service industrial purchasers receive from suppliers has been shown to be an important consideration in industrial purchasing decisions. To better understand the criteria used to assess physical distribution service quality, the authors examined the literature on physical distribution and service quality and conducted interviews with purchasing managers. Based on the results of the literature reviews and interviews, plus a two-step data-gathering process, a valid and reliable measurement instrument for perceptions of physical distribution service quality (PDSQ) was developed and refined.

Spontaneous Subthreshold Membrane Potential Fluctuations and Action Potential Variability of Rat Corticostriatal and Striatal Neurons In Vivo

Abstract: Stern, Edward A., Anthony E. Kincaid, and Charles J. Wilson. Spontaneous subthreshold membrane potential fluctuations and action potential variability of rat corticostriatal and striatal neurons in...

"Completely Different Worlds": EAP and the Writing Experiences of ESL Students in University Courses

Abstract: One source of information that should inform decisions about English for academic purposes (EAP) writing courses is students' experiences in those courses and beyond. A survey of ESL students in the U.S. (Leki & Carson, 1994) has indicated that they experience writing differently depending on the source of information drawn on in writing a text: general world knowledge or personal experience; a source text or texts used as a springboard for ideas; or a source text (or other external reality), the content of which the student must display knowledge. This article, based on interview data, reports on how ESL students experience writing under each of these conditions in their EAP writing classes and their academic content classes across the curriculum. The findings suggest that writing classes require students to demonstrate knowledge of a source text much less frequently than other academic courses do. We argue that EAP classes that limit students to writing without source texts or to writing without responsibility for the content of source texts miss the opportunity to engage L2 writing students in the kinds of interactions with text that promote linguistic and intellectual growth. To explain and understand any human social behavior … we need to know the meaning attached to it by the participants themselves. (Nielsen, 1990)

Interparental Conflict and Youth Problem Behaviors: A Meta-Analysis

Abstract: We examined the proposition that interparental conflict is associated with internalizing and externalizing problems in youth ages 5 to 18. This examination was done by conducting a meta-analysis of 348 statistical effects from 68 studies. The average effect size (d-value) was .32. There was considerable variability among effect sizes and this variability was associated with the average time since separation for separated/divorced parents, the socioeconomic status composition of the sample, and average parental education in the sample. The variability among effect sizes also was associated with the source of the informant used to assess interparental conflict and youth problem behaviors. Surprisingly, many of the other study characteristics we coded were not associated with variability in the effect sizes.

Extraction of a hydrophilic compound from water into liquid CO2 using dendritic surfactants

Abstract: Dendrimers are well defined, highly branched polymers1,2,3,4,5 that adopt a roughly spherical, globular shape in solution. Their cores are relatively loosely packed and can trap guest molecules5,6,7, and by appropriate functionalization of the branch tips the macromolecules can act as unimolecular micelle-like entities6. Here we show that dendrimers with a fluorinated shell are soluble in liquid carbon dioxide and can transport CO2-insoluble molecules into this solvent within their cores. Specifically, we demonstrate the extraction of a polar ionic dye, methyl orange, from water into CO2 using these fluorinated dendrimers. This observation suggests possible uses of such macromolecules for the remediation of contaminated water, the extraction of pharmaceutical products from fermentation vessels, the selective encapsulation of drugs for targeted delivery6,7 and the transport of reagents for chemical reactions (such as polymerization8,9,10,11) in liquid and supercritical CO2 solvents.

Evolution and speciation on holey adaptive landscapes

Abstract: Sewall Wright's powerful metaphor of rugged adaptive landscapes has formed the basis for discussing evolution and speciation for more than 60 years. However, this metaphor, with its emphasis on adaptive peaks and valleys, is to a large degree a reflection of our three-dimensional experience. Both genotypes and phenotypes of biological organisms differ in numerous characteristics, and, thus, the dimension of 'real' adaptive landscapes is much larger than three. Properties of multidimensional adaptive landscapes are very different from those of low dimension. Consequently, something that is seen as a theoretical challenge in a low-dimensional case might be a trivial problem in a multidimensional context and vice versa. In particular, the problem of how a population crosses an adaptive valley on its way from one adaptive peak to another, which Wright attempted to solve with his shifting balance theory, may be non-existent. A new framework is emerging for deepening our understanding of evolution and speciation, which provides a plausible multidimensional alternative to the conventional view of rugged adaptive landscapes.

Angiotensin II increases lipogenesis in 3T3-L1 and human adipose cells.

Abstract: Angiotensin II (Ang II) is one of numerous hormones recently shown to be synthesized and secreted by adipose cells. Although the function of Ang II in adipose tissue is unknown, several studies indirectly suggest that it may be involved in control of adiposity. Little is known, however, about direct actions of Ang II in adipose cells. To further investigate this issue, we first characterized the type of Ang II receptors in 3T3-L1 adipocytes. We then tested the hypothesis that Ang II exerted direct actions on adipocyte metabolism using both 3T3-L1 and human adipocyte models. We report here that Ang II significantly increased triglyceride content and the activities of two key lipogenic enzymes (fatty acid synthase, FAS and glycerol-3-phosphate dehydrogenase, GPDH) in 3T3-L1 adipocytes, and that these effects were mediated through the type-2 Ang II receptor. We also report that Ang II exerted similar effects in human adipose cells maintained in primary culture. Finally, we demonstrate that Ang II increased t...

Pre-Columbian Native American Use of Fire on Southern Appalachian Landscapes

Abstract: Fire suppression in the southern Appalachians is widely considered responsible for decreased regeneration in oak (Quercus) and fire-adapted species such as table mountain pine (Pinus rigida) and pitch pine (Pinus pungens) (Barden & Woods 1976; Harmon 1982; Abrams 1992). How fire-adapted species survived in the southern Appalachian highlands in pre-Columbian times is an enigma; lightning-set fires are very infrequent (Harmon 1982; Bratton & Meier 1995) in this region of high annual precipitation. Barden and Woods (1976), Harmon (1982), and Abrams (1992) have speculated that in preColumbian times, Native American use of fire may have been important in the eastern deciduous forest region, but no published studies have documented that the use of fire by prehistoric Native Americans affected the composition of southern Appalachian vegetation. We evaluated the importance of pre-Columbian human impacts on vegetation of the southern Appalachian highlands by comparing the fossil pollen and charcoalparticle record preserved in peat deposited during the past 3900 calendar years in Horse Cove Bog, Highlands, North Carolina, with the archaeological record. We examined the implications of our fidings for conserving biodiversity and maintaining landscape heterogeneity using prescribed burning.

Netsolve: a Network-Enabled Server for Solving Computational Science Problems

Abstract: This paper presents a new system, called NetSolve, that allows users to access computational resources, such as hardware and software, distributed across the network. The development of NetSolve was motivated by the need for an easy-to-use, efficient mechanism for using compu tational resources remotely. Ease of use is obtained as a result of different interfaces, some of which require no programming effort from the user. Good performance is ensured by a load-balancing policy that enables NetSolve to use the computational resources available as efficiently as possible. NetSolve offers the ability to look for compu tational resources on a network, choose the best one available, solve a problem with retry for fault tolerance, and return the answer to the user.

An Economic Analysis of Domestic Violence

Abstract: While economists have been studying the family as an economic unit for almost thirty years, most models have focused on cooperative family units. Domestic violence, one of the most widespread violent crimes against women, is one example of a family unit that is better explained as a noncooperative re1ationship. In this paper, a noncooperative model of domestic violence is presented. The comparative statics from this model predict that women's incomes and other financial support received from outside the marriage (family, welfare, shelters, divorce settlements, etc.) will decrease the level of violence in intact families because they increase the woman's threat point. Implications of the theoretical model are discussed and empirical evidence is summarized. The results from existing and new analysis provide support for the hypothesis that improved economic opportunities for women will decrease the level of violence in abusive re1ationships.