University of Minnesota

About: University of Minnesota is a education organization based out in Minneapolis, Minnesota, United States. It is known for research contribution in the topics: Population & Transplantation. The organization has 117432 authors who have published 257986 publications receiving 11944239 citations. The organization is also known as: University of Minnesota, Twin Cities & University of Minnesota-Twin Cities.

A critical assessment of potential measurement biases in the technology acceptance model: three experiments

Abstract: The Technology Acceptance Model (TAM) is widely used by researchers and practitioners to predict and explain user acceptance of information technologies. TAM models system usage intentions and behavior as a function of perceived usefulness and perceived ease of use. The original scales for measuring the TAM constructs have been confirmed to be reliable and valid in several replications and applications spanning a range of technologies and user populations. However, a measurement bias may be present because the TAM instrument physicallygroupstogether the multiple items measuring each individual construct. Many scholars of instrument design would object to such item grouping, instead advocating that items from different constructs beintermixedin order to reduce “carryover” effects among the responses to multiple items targeting a specific construct, which might artificially inflate the observed reliability and validity. Three experiments involving two systems and a total of 708 subjects are reported which address whether such carryover biases are present in the TAM measures. All three studies found that itemgroupingvs. itemintermixinghad no significant effect (positive or negative) either on the high levels of reliability and validity of the TAM scales, or on the path coefficients linking them together. Ironically, open-ended verbal evaluations indicated that subjects were more confused and annoyed when items wereintermixed,suggesting a tendency toward “output interference” effects, which themselves could have a biasing effect. Our findings suggest that those who employ the TAM measures should continue using the original (grouped)format in order to best predict and explain user acceptance of information technology.

A Capabilities Perspective on the Effects of Early Internationalization on Firm Survival and Growth

Abstract: Recent critiques of internationalization process models question the wisdom of delaying internationalization. Internationalizing late allows firms to assemble resources and gain experience but also allows inertia to develop. We resolve this tension by positing that internationalization has differing effects on firm survival and growth. These effects are moderated by organizational age, managerial experience, and resource fungibility. Our framework provides insights into the evolution of capabilities across borders and may be tested and built on by organization researchers.

A Role for Flavin Monooxygenase-Like Enzymes in Auxin Biosynthesis

Abstract: Although auxin is known to regulate many processes in plant development and has been studied for over a century, the mechanisms whereby plants produce it have remained elusive. Here we report the characterization of a dominant Arabidopsis mutant, yucca, which contains elevated levels of free auxin. YUCCA encodes a flavin monooxygenase-like enzyme and belongs to a family that includes at least nine other homologous Arabidopsis genes, a subset of which appears to have redundant functions. Results from tryptophan analog feeding experiments and biochemical assays indicate that YUCCA catalyzes hydroxylation of the amino group of tryptamine, a rate-limiting step in tryptophan-dependent auxin biosynthesis.

Global-Scale Similarities in Nitrogen Release Patterns During Long-Term Decomposition

Abstract: Litter decomposition provides the primary source of mineral nitrogen (N) for biological activity in most terrestrial ecosystems. A 10-year decomposition experiment in 21 sites from seven biomes found that net N release from leaf litter is dominantly driven by the initial tissue N concentration and mass remaining regardless of climate, edaphic conditions, or biota. Arid grasslands exposed to high ultraviolet radiation were an exception, where net N release was insensitive to initial N. Roots released N linearly with decomposition and exhibited little net N immobilization. We suggest that fundamental constraints on decomposer physiologies lead to predictable global-scale patterns in net N release during decomposition.