University of Colorado Denver

About: University of Colorado Denver is a education organization based out in Denver, Colorado, United States. It is known for research contribution in the topics: Population & Health care. The organization has 27444 authors who have published 57213 publications receiving 2539937 citations. The organization is also known as: CU Denver & UCD.

Activity-dependent fluorescent staining and destaining of living vertebrate motor nerve terminals.

Abstract: Living motor nerve terminals from several species can be stained in an activity-dependent fashion by certain styryl dyes, such as RH414, RH795, and a new dye, FM1–43, which can be imaged independently of the others. The dyes evidently become trapped within recycled synaptic vesicles. In frog cutaneus pectoris muscle, bright fluorescent spots spaced regularly along the length of the nerve terminals appear after stimulation in the presence of the dye. The spots align well with postsynaptic ACh receptors and are persistent for many hours, unless further stimulation is given, in which case the spots disappear. Destaining, like staining, requires transmitter release and proceeds gradually over several minutes at high stimulus frequencies (e.g., 30 Hz), and fluorescent spots in the same terminal disappear at about the same rate. We suggest that each spot is a cluster of hundred of synaptic vesicles and that the mechanism of staining involves the ability of the dyes to partition reversibly into the outer leaflet of surface membranes, without being able to penetrate the entire membrane thickness. Then, during endocytosis following transmitter release, dye molecules become trapped in recycled synaptic vesicle membranes. The dyes therefore make it possible optically to study vesicle exocytosis and recycling in living nerve terminals in real time, and should be useful for marking terminals in a variety of preparations according to their level of activity.

Experimental and Quasi-Experimental Studies of Inquiry-Based Science Teaching A Meta-Analysis

Abstract: Although previous meta-analyses have indicated a connection between inquiry-based teaching and improved student learning, the type of instruction characterized as inquiry based has varied greatly, and few have focused on the extent to which activities are led by the teacher or student. This meta-analysis introduces a framework for inquiry-based teaching that distinguishes between cognitive features of the activity and degree of guidance given to students. This framework is used to code 37 experimental and quasi-experimental studies published between 1996 and 2006, a decade during which inquiry was the main focus of science education reform. The overall mean effect size is .50. Studies that contrasted epistemic activities or the combination of procedural, epistemic, and social activities had the highest mean effect sizes. Furthermore, studies involving teacher-led activities had mean effect sizes about .40 larger than those with student-led conditions. The importance of establishing the validity of the tre...

Gaining Advanced Manufacturing Technologies' Benefits: The Roles of Organization Design and Culture

Abstract: The literature on advanced manufacturing technologies (AMTs) shows that a wide range of outcomes have been experienced by organizations that have adopted these technologies, ranging from implementation failure to increased productivity and enhanced organizational flexibility. This article examines the roles that organization design and culture play in the varying levels of success experienced by AMT-adopting organizations. Several hypotheses are presented on the relationships among culture, structure, and implementation outcomes based on the competing values model of organizational culture.

Understanding Post-Adoption Behavior in the Context of Online Services

Abstract: This paper examines post-adoption behavior (continued adoption versus discontinuance) within the context of online service use. Innovation diffusion theory is used as a theoretical framework to extend information technology adoption research to the case of post-adoption behavior. This theory is used to formulate 11 research hypotheses distinguishing discontinuers from continuing adopters and exploring reasons behind their discontinuance (replacement versus disenchantment). These hyp otheses were then empirically tested using data collected from a field survey of online service users. Our results indicate that potential discontinuers can be discriminated from continued adopters based on their sources of influence (external and interpe rsonal), perceived service attributes (usefulness and compatibility), service utilization, and network externality (complementary product usage), during their time of initial adoption. We also found that later adopters are more likely to discontinue due to disenchantment than replacement, and are more influenced by interpersonal sources and utilize the service less during their adoption period than replacement discontinuers. Implications for research and practice are drawn.

Tests of the helix dipole model for stabilization of α-helices

Abstract: Charged groups play a critical role in the stability of the helix formed by the isolated C-peptide (residues 1-13 of ribonuclease A) in aqueous solution. One charged-group effect may arise from interactions between charged residues at either end of the helix and the helix dipole. We report here that studies of C-peptide analogues support the helix dipole model, and provide further evidence for the importance of electrostatic interactions not included in the Zimm-Bragg model for alpha-helix formation.