Showing papers by "University of Georgia published in 2003"

Trust and TAM in online shopping: an integrated model

Abstract: A separate and distinct interaction with both the actual e-vendor and with its IT Web site interface is at the heart of online shopping Previous research has established, accordingly, that online purchase intentions are the product of both consumer assessments of the IT itself-specifically its perceived usefulness and ease-of-use (TAM)-and trust in the e-vendor But these perspectives have been examined independently by IS researchers Integrating these two perspectives and examining the factors that build online trust in an environment that lacks the typical human interaction that often leads to trust in other circumstances advances our understanding of these constructs and their linkages to behavior Our research on experienced repeat online shoppers shows that consumer trust is as important to online commerce as the widely accepted TAM use-antecedents, perceived usefulness and perceived ease of use Together these variable sets explain a considerable proportion of variance in intended behavior The study also provides evidence that online trust is built through (1) a belief that the vendor has nothing to gain by cheating, (2) a belief that there are safety mechanisms built into the Web site, and (3) by having a typical interface, (4) one that is, moreover, easy to use

Updating the Beers criteria for potentially inappropriate medication use in older adults: results of a US consensus panel of experts.

Abstract: Background Medication toxic effects and drug-related problems can have profound medical and safety consequences for older adults and economically affect the health care system. The purpose of this initiative was to revise and update the Beers criteria for potentially inappropriate medication use in adults 65 years and older in the United States. Methods This study used a modified Delphi method, a set of procedures and methods for formulating a group judgment for a subject matter in which precise information is lacking. The criteria reviewed covered 2 types of statements: (1) medications or medication classes thatshould generally be avoidedin persons 65 years or older because they are either ineffective or they pose unnecessarily high risk for older persons and a safer alternative is available and (2) medications that should not be used in older persons known to havespecific medical conditions. Results This study identified 48 individual medications or classes of medications to avoid in older adults and their potential concerns and 20 diseases/conditions and medications to be avoided in older adults with these conditions. Of these potentially inappropriate drugs, 66 were considered by the panel to have adverse outcomes of high severity. Conclusions This study is an important update of previously established criteria that have been widely used and cited. The application of the Beers criteria and other tools for identifying potentially inappropriate medication use will continue to enable providers to plan interventions for decreasing both drug-related costs and overall costs and thus minimize drug-related problems.

Energy, water, and broad-scale geographic patterns of species richness

Abstract: It is often claimed that we do not understand the forces driving the global diversity gradient. However, an extensive literature suggests that contemporary climate constrains terrestrial taxonomic richness over broad geographic extents. Here, we review the empirical literature to examine the nature and form of the relationship between climate and richness. Our goals were to document the support for the climatically based energy hypothesis, and within the constraints imposed by correlative analyses, to evaluate two versions of the hypothesis: the productivity and ambient energy hypotheses. Focusing on studies extending over 800 km, we found that measures of energy, water, or water-energy balance explain spatial variation in richness better than other climatic and non-climatic variables in 82 of 85 cases. Even when considered individually and in isolation, water/ energy variables explain on average over 60% of the variation in the richness of a wide range of plant and animal groups. Further, water variables usually represent the strongest predictors in the tropics, subtropics, and warm temperate zones, whereas energy variables (for animals) or water-energy variables (for plants) dominate in high latitudes. We conclude that the interaction between water and energy, either directly or indirectly (via plant productivity), provides a strong explanation for globally extensive plant and animal diversity gradients, but for animals there also is a latitudinal shift in the relative importance of ambient energy vs. water moving from the poles to the equator. Although contemporary climate is not the only factor influencing species richness and may not explain the diversity pattern for all taxonomic groups, it is clear that understanding water-energy dynamics is critical to future biodiversity research. Analyses that do not include water-energy variables are missing a key component for explaining broad-scale patterns of diversity.

Evolutionary models for cool brown dwarfs and extrasolar giant planets. The case of HD 20945

Abstract: We present evolutionary models for cool brown dwarfs and extra-solar giant planets. The models reproduce the main trends of observed methane dwarfs in near-IR color-magnitude diagrams. We also present evolutionary models for irradiated planets, coupling for the first time irradiated atmosphere profiles and inner structures. We focus on HD 209458-like systems and show that irradiation effects can substantially affect the radius of sub-jovian mass giant planets. Irradiation effects, however, cannot alone explain the large observed radius of HD 209458b. Adopting assumptions which optimise irradiation effects and taking into account the extension of the outer atmospheric layers, we still find $\sim$ 20% discrepancy between observed and theoretical radii. An extra source of energy seems to be required to explain the observed value of the first transit planet.

Toward a Conceptualization of Optimal Self-Esteem.

Abstract: In this article, I present a theoretical perspective on the nature of "optimal" self-esteem. One of my major goals is to show that optimal and high self-esteem are different from each other. High self-esteem can be fragile or secure depending upon the extent to which it is defensive or genuine, contingent or true, unstable or stable, and discrepant or congruent with implicit (nonconscious) feelings of self-worth. Optimal self-esteem is characterized by qualities associated with genuine, true, stable, and congruent (with implicit self-esteem) high self-esteem. A second major goal is to present a conceptualization of the construct of authenticity. I propose that authenticity as an individual difference construct may be particularly important in delineating the adaptive features of optimal self-esteem. Authenticity can be characterized as the unobstructed operation of one's true, or core, self in one's daily enterprise. I argue that authenticity has 4 components: awareness, unbiased processing, action, and r...

Sources of influence on beliefs about information technology use: an empirical study of knowledge workers

Abstract: Individual beliefs about technology use have been shown to have a profound impact on subsequent behaviors toward information technology (IT). This research note builds upon and extends prior research examining factors that influence key individual beliefs about technology use. It is argued that individuals form beliefs about their use of information technologies within a broad milieu of influences emanating from the individual, institutional, and social contexts in which they interact with IT. We examine the simultaneous effects of these three sets of influences on beliefs about usefulness and ease of use in the context of a contemporary technology targeted at autonomous knowledge workers. Our findings suggest that beliefs about technology use can be influenced by top management commitment to new technology and the individual factors of personal innovativeness and self-efficacy. Surprisingly, social influences from multiple sources exhibited no significant effects. Theoretical and practical implications are offered.

Demonstrating the Value of an Organization's Learning Culture: The Dimensions of the Learning Organization Questionnaire

Abstract: The problem and the solution. Some organizations seek to become learning organizations. Yet, implementation is elusive and is not often based on research about what constitutes a learning culture. Over the past 16 years, a model of a learning organization was developed that draws on both the literature and organizational case studies. However, organizations wanted a way to diagnose their current status and guide change, and scholars wanted better measures of learning to compare organizations and to explore links between organizational learning and the performance of the firm. The solution was to develop and validate an instrument that addresses these needs.

The Cholinergic Hypothesis of Age and Alzheimer's Disease-Related Cognitive Deficits: Recent Challenges and Their Implications for Novel Drug Development

Abstract: The cholinergic hypothesis was initially presented over 20 years ago and suggests that a dysfunction of acetylcholine containing neurons in the brain contributes substantially to the cognitive decline observed in those with advanced age and Alzheimer's disease (AD). This premise has since served as the basis for the majority of treatment strategies and drug development approaches for AD to date. Recent studies of the brains of patients who had mild cognitive impairment or early stage AD in which choline acetyltransferase and/or acetylcholinesterase activity was unaffected (or even up-regulated) have, however, led some to challenge the validity of the hypothesis as well as the rationale for using cholinomimetics to treat the disorder, particularly in the earlier stages. These challenges, primarily based on assays of post mortem enzyme activity, should be taken in perspective and evaluated within the wide range of cholinergic abnormalities known to exist in both aging and AD. The results of both post mortem and antemortem studies in aged humans and AD patients, as well as animal experiments suggest that a host of cholinergic abnormalities including alterations in choline transport, acetylcholine release, nicotinic and muscarinic receptor expression, neurotrophin support, and perhaps axonal transport may all contribute to cognitive abnormalities in aging and AD. Cholinergic abnormalities may also contribute to noncognitive behavioral abnormalities as well as the deposition of toxic neuritic plaques in AD. Therefore, cholinergic-based strategies will likely remain valid as one approach to rational drug development for the treatment of AD other forms of dementia.

Bacterial mercury resistance from atoms to ecosystems

Abstract: Bacterial resistance to inorganic and organic mercury compounds (HgR) is one of the most widely observed phenotypes in eubacteria. Loci conferring HgR in Gram-positive or Gram-negative bacteria typically have at minimum a mercuric reductase enzyme (MerA) that reduces reactive ionic Hg(II) to volatile, relatively inert, monoatomic Hg(0) vapor and a membrane-bound protein (MerT) for uptake of Hg(II) arranged in an operon under control of MerR, a novel metal-responsive regulator. Many HgR loci encode an additional enzyme, MerB, that degrades organomercurials by protonolysis, and one or more additional proteins apparently involved in transport. Genes conferring HgR occur on chromosomes, plasmids, and transposons and their operon arrangements can be quite diverse, frequently involving duplications of the above noted structural genes, several of which are modular themselves. How this very mobile and plastic suite of proteins protects host cells from this pervasive toxic metal, what roles it has in the biogeochemical cycling of Hg, and how it has been employed in ameliorating environmental contamination are the subjects of this review.

Inexperience and experience with online stores: the importance of TAM and trust

Abstract: An e-vendor's website inseparably embodies an interaction with the vendor and an interaction with the IT website interface. Accordingly, research has shown two sets of unrelated usage antecedents by customers: (1) customer trust in the e-vendor and (2) customer assessments of the IT itself, specifically the perceived usefulness and perceived ease-of-use of the website as depicted in the technology acceptance model (TAM). Research suggests, however, that the degree and impact of trust, perceived usefulness, and perceived ease of use change with experience. Using existing, validated scales, this study describes a free-simulation experiment that compares the degree and relative importance of customer trust in an e-vendor vis-a-vis TAM constructs of the website, between potential (i.e., new) customers and repeat (i.e., experienced) ones. The study found that repeat customers trusted the e-vendor more, perceived the website to be more useful and easier to use, and were more inclined to purchase from it. The data also show that while repeat customers' purchase intentions were influenced by both their trust in the e-vendor and their perception that the website was useful, potential customers were not influenced by perceived usefulness, but only by their trust in the e-vendor. Implications of this apparent trust-barrier and guidelines for practice are discussed.

Predictors of success in the era of the boundaryless career

Abstract: Summary The present study examines three classes of career competencies proposed as important predictors of success in the boundaryless career. Three criteria of career success were examined: perceived career satisfaction, perceived internal marketability, and perceived external marketability. Using data from 458 alumni from a large southeastern university, predictions were tested using partial correlations and dominance analysis. The results found support for the importance of ‘knowing why,’ ‘knowing whom,’ and ‘knowing how’ as suggested by previous theoretical work. The findings are discussed in reference to future research and theorizing on the boundaryless career. Copyright # 2003 John Wiley & Sons, Ltd.

Parenthood and Marital Satisfaction: A Meta-Analytic Review.

Abstract: This meta-analysis finds that parents report lower marital satisfaction compared with nonparents (d=−.19, r=−.10). There is also a significant negative correlation between marital satisfaction and number of children (d=−.13, r=−.06). The difference in marital satisfaction is most pronounced among mothers of infants (38% of mothers of infants have high marital satisfaction, compared with 62% of childless women). For men, the effect remains similar across ages of children. The effect of parenthood on marital satisfaction is more negative among high socioeconomic groups, younger birth cohorts, and in more recent years. The data suggest that marital satisfaction decreases after the birth of a child due to role conflicts and restriction of freedom.

Diversity and Succession of the Intestinal Bacterial Community of the Maturing Broiler Chicken

Abstract: The diversity of bacterial floras in the ilea and ceca of chickens that were fed a vegetarian corn-soy broiler diet devoid of feed additives was examined by analysis of 1,230 partial 16S rRNA gene sequences. Nearly 70% of sequences from the ileum were related to those of Lactobacillus, with the majority of the rest being related to Clostridiaceae (11%), Streptococcus (6.5%), and Enterococcus (6.5%). In contrast, Clostridiaceae-related sequences (65%) were the most abundant group detected in the cecum, with the other most abundant sequences being related to Fusobacterium (14%), Lactobacillus (8%), and Bacteroides (5%). Statistical analysis comparing the compositions of the different 16S rRNA libraries revealed that population succession occurred during some sampling periods. The significant differences among cecal libraries at 3 and 7 days of age, at 14 to 28 days of age, and at 49 days of age indicated that successions occurred from a transient community to one of increasing complexity as the birds aged. Similarly, the ileum had a stable bacterial community structure for birds at 7 to 21 days of age and between 21 to 28 days of age, but there was a very unique community structure at 3 and 49 days of age. It was also revealed that the composition of the ileal and cecal libraries did not significantly differ when the birds were 3 days old, and in fact during the first 14 days of age, the cecal microflora was a subset of the ileal microflora. After this time, the ileum and cecum had significantly different library compositions, suggesting that each region developed its own unique bacterial community as the bird matured.

The Relations Among Environmental Disclosure, Environmental Performance, and Economic Performance: A Simultaneous Equations Approach

Abstract: This study provides an integrated analysis of the interrelations among (1) environmental disclosure, (2) environmental performance, and (3) economic performance. Based on the argument that management's (unobservable) overall strategy affects each of these corporate responsibilities, we conjecture that prior literature's mixed results describing their interrelations may be attributable to the fact that researchers have not considered these functions to be jointly determined. After endogenizing these corporate functions in simultaneous equations models, we obtain results that suggest "good" environmental performance is significantly associated with "good" economic performance, and also with more extensive quantifiable environmental disclosures of specific pollution measures and occurrences.

Neutral theory and relative species abundance in ecology.

Abstract: The theory of island biogeography asserts that an island or a local community approaches an equilibrium species richness as a result of the interplay between the immigration of species from the much larger metacommunity source area and local extinction of species on the island (local community). Hubbell generalized this neutral theory to explore the expected steady-state distribution of relative species abundance (RSA) in the local community under restricted immigration. Here we present a theoretical framework for the unified neutral theory of biodiversity and an analytical solution for the distribution of the RSA both in the metacommunity (Fisher's log series) and in the local community, where there are fewer rare species. Rare species are more extinction-prone, and once they go locally extinct, they take longer to re-immigrate than do common species. Contrary to recent assertions, we show that the analytical solution provides a better fit, with fewer free parameters, to the RSA distribution of tree species on Barro Colorado Island, Panama, than the lognormal distribution.

A Review of Cross-Cultural Methodologies for Organizational Research: A Best- Practices Approach:

Abstract: Cross-cultural studies that use self-report instruments can present researchers with a variety of challenges. This article reviews the organizational research literature between the years of 1995 and 2001 to identify common practices prevalent in this type of research. Key methodological issues are examined within the context of a three-stage framework: (a) the development of the research question, (b) the alignment of the research contexts, and (c) the validation of the research instruments. This examination serves as a basis for the identification of best-practice recommendations for cross-cultural researchers.

Biofilm Formation and Control in Food Processing Facilities

Abstract: Microorganisms on wet surfaces have the ability to aggregate, grow into microcolonies, and produce biofilm. Growth of biofilms in food processing environments leads to increased opportunity for microbial contamination of the processed product. These biofilms may contain spoilage and pathogenic microorganisms. Microorganisms within biofilms are protected from sanitizers increasing the likelihood of survival and subsequent contamination of food. This increases the risk of reduced shelf life and disease transmission. Extracellular polymeric substances associated with biofilm that are not removed by cleaning provide attachment sites for microorganisms newly arrived to the cleaned system. Biofilm formation can also cause the impairment of heat transfer and corrosion to metal surfaces. Some of the methods used to control biofilm formation include mechanical and manual cleaning, chemical cleaning and sanitation, and application of hot water.

Patterns of engagement in authentic online learning environments

Abstract: The use of authentic activities within online learning environments has been shown to have many benefits for learners in online units and courses. There has been renewed interest in the role of student activities within course units, as constructivist philosophy and advances in technology impact on educational design and practice. Courses based on these principles have been used successfully across a wide variety of discipline areas. In spite of the growing evidence of the success of authentic learning environments, they are not without their problems. In this paper we discuss patterns of engagement that have emerged from our own research on authentic learning tasks, in particular, the initial reluctance to willingly immerse in learning scenarios that some students experience, and the need for the suspension of disbelief before engaging in the task. The paper proposes ten characteristics of authentic activities, based on educational theory and research, which have been used as criteria for the selection of existing online units or courses for in depth investigation. The paper includes a short review of the literature, a description of the research and some preliminary findings and identification of issues related to the necessity for students to willingly suspend disbelief in order to fully engage in learning scenarios based on authentic tasks.

What is hydrologic connectivity and why is it ecologically important

Abstract: Hydrologic connectivity (sensu Pringle, 2001) is used here in an ecological context to refer to water-mediated transfer of matter, energy and/or organisms within or between elements of the hydrologic cycle. Hydrologic connectivity is essential to the ecological integrity of the landscape, and reduction or enhancement of this property by humans can have major negative environmental effects. Some of these effects are immediate, localized and, therefore, obvious. For example, with respect to migratory fish, a given dam may act to reduce hydrologic connectivity (by preventing or impeding migration up or downstream), whereas interbasin river transfers enhance this property by allowing the dispersal of fish into river basins outside of their range. Less obvious, are alterations in hydrologic connectivity that exhibit a time lag and manifest themselves at geographic locations far from the source of disturbance. An example concerns the cumulative effect of dams on transport of the inorganic dissolved solute silica. Dams and associated impoundments can reduce the transport of this compound, which becomes deposited in the bottoms of reservoirs (Humborg et al., 2000). The cumulative effects of many dams along a river can potentially result in a reduction in the amount of silica delivered to coastal waters, with consequent negative effects on coastal food web structure that contribute to eutrophication (Justic et al., 1995; Turner et al., 1998). Management and policy decisions regarding land-use activities and hydropower development are often made in the absence of adequate information on hydrologic connectivity in the landscape. Our current knowledge of how this property maintains the ecological integrity of ‘natural’ ecosystems is poor due to: (1) the inherent complexity of water movement within and between the atmosphere and surface–subsurface systems; and (2) the extent and magnitude of human alterations, which often occur before we understand how hydrologic connectivity affects ecological patterns in the landscape (Pringle and Triska, 2000). Hydrologic connectivity is being altered at a rate unprecedented in geologic history, contributing to dramatic losses in global aquatic biodiversity and associated ecosystem integrity (e.g. Dudgeon, 2000; Pringle et al., 2000; Rosenberg et al., 2000). Humans have already appropriated one-half of the accessible global freshwater runoff and this could climb to 70% by 2025 (Postel et al., 1996).

Phenotypic plasticity and interactions among plants

Abstract: We know a great deal about the plastic responses of plant phenotypes to the abiotic and biotic environment, but very little about the consequences of phenotypic plas- ticity for plant communities. In other words, we know that plant traits can vary widely for a given genotype, but we know little about the importance of trait-mediated interactions (TMI) among plants. Here, we discuss three major factors that affect the expression of phenotypic plasticity: variation in the abiotic environment, variation in the presence or identity of neighbors, and variation in herbivory. We consider how plastic responses to these factors might affect interactions among plants. Plastic responses to the abiotic en- vironment have important consequences for conditionality in competitive effects, to the point of causing shifts from competitive to facilitative interactions. Because plants show a high degree of plasticity in response to neighbors, and even to the specific identify of neighbors, phenotypic plasticity may allow species to adjust to the composition of their communities, promoting coexistence and community diversity. Likewise, plastic responses to consumers may have various and counterintuitive consequences: induction of plant re- sistance, compensatory growth, and increased resource uptake may affect interactions among plants in ways that cannot be predicted simply by considering biomass lost to consumers. What little we know about TMI among plants suggests that they should not be ignored in plant community theory. Although work to date on the community consequences of phenotypic plasticity has been hampered by experimental constraints, new approaches such as manipulating phenotypes by using signals instead of actual environmental conditions and the use of transgenic plants should allow us to rapidly expand our understanding of the community consequences of plant plasticity.

River flows and water wars: emerging science for environmental decision making

Abstract: Real and apparent conflicts between ecosystem and human needs for fresh water are contributing to the emergence of an alternative model for conducting river science around the world. The core of this new paradigm emphasizes the need to forge new partnerships between scientists and other stakeholders where shared ecological goals and river visions are developed, and the need for new experimental approaches to advance scientific understanding at the scales relevant to whole-river management. We identify four key elements required to make this model succeed: existing and planned water projects represent opportunities to conduct ecosystem-scale experiments through controlled river flow manipulations; more cooperative interactions among scientists, managers, and other stakeholders are critical; experimental results must be synthesized across studies to allow broader generalization; and new, innovative funding partnerships are needed to engage scientists and to broadly involve the government, the private sector, and NGOs.

METEOR-S WSDI: A Scalable P2P Infrastructure of Registries for Semantic Publication and Discovery of Web Services

Abstract: Web services are the new paradigm for distributed computing. They have much to offer towards interoperability of applications and integration of large scale distributed systems. To make Web services accessible to users, service providers use Web service registries to publish them. Current infrastructure of registries requires replication of all Web service publications in all Universal Business Registries. Large growth in number of Web services as well as the growth in the number of registries would make this replication impractical. In addition, the current Web service discovery mechanism is inefficient, as it does not support discovery based on the capabilities of the services, leading to a lot of irrelevant matches. Semantic discovery or matching of services is a promising approach to address this challenge. In this paper, we present a scalable, high performance environment for Web service publication and discovery among multiple registries. This work uses an ontology-based approach to organize registries into domains, enabling domain based classification of all Web services. Each of these registries supports semantic publication and discovery of Web services. We believe that the semantic approach suggested in this paper will significantly improve Web service publication and discovery involving a large number of registries. This paper describes the implementation and architecture of the METEOR-S Web Service Discovery Infrastructure, which leverages peer-to-peer computing as a scalable solution.

Guidelines for the Selection of Anti-infective Agents for Complicated Intra-abdominal Infections

Abstract: Joseph S. Solomkin, John E. Mazuski, Ellen J. Baron, Robert G. Sawyer, Avery B. Nathens, Joseph T. DiPiro, Timothy Buchman, E. Patchen Dellinger, John Jernigan, Sherwood Gorbach, Anthony W. Chow, and John Bartlett Department of Surgery, University of Cincinnati College of Medicine, Cincinnati, Ohio; Department of Surgery, Washington University School of Medicine, St. Louis, Missouri; Department of Microbiology, Stanford University School of Medicine, Palo Alto, California; Department of Surgery, University of Virginia, Charlottesville; Department of Surgery, University of Washington, Seattle; University of Georgia College of Pharmacy, Department of Surgery, Medical College of Georgia, Augusta, and Centers for Disease Control and Prevention, Atlanta; Department of Medicine, Tufts University School of Medicine, Boston, Massachusetts; Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland; and Department of Medicine, University of British Columbia, Vancouver, British Columbia, Canada