Creating a Student Centered Learning Environment at the University of Denver

A team of faculty members at the University of Denver changed the learning environment in key courses in the Department of Engineering from predominately teacher centered to student centered. Through this funded project new grading methods were implemented, classrooms were renovated and wired with studio layouts to facilitate learning, the Engineering Circuits Laboratory was rewired and instrumented for automated data acquisition and reporting, and two new pedagogical approaches were developed. At the onset of the project, six goals were established related to student learning. The introduction of industry standard hardware and software provided students with unprecedented hands‐on experience and project related activities stimulated faculty innovations in other current and future courses. Assessment results indicate that the new grading system improved the clarity of expectations for students before assignments were given resulting in increased reported motivation for learning in many courses. Even though course GPAs did not always reflect higher achievement on graded work, faculty members firmly believe that deeper understanding was achieved because more complex material was assimilated.     

Effects of urbanization on the aquatic fauna of the Line Creek watershed, Atlanta—a satellite perspective

Impervious surface area (ISA) was derived for a period from 1979 to 1997 from Landsat MSS and TM data for the Line Creek watershed that lies to the south of the city of Atlanta, GA. The change in ISA is presented as an ecological indicator to examine the cumulative water resource impacts on mussel population in three sub-watersheds of Line Creek—namely, Line, Flat, and Whitewater creeks. The satellite analysis shows that ISA expansion occurred substantially from 1987 to 1997 and is predominantly in industrial, commercial, and shopping center (ICS) complexes but also in smaller lot-size residential development. Evidence of mussel habitat degradation is indicated and loss of species (in the region of 50 to 70%) is present in areas where ISA expansion is observed—specifically in ICS complex development in and around Peachtree City that drains directly into the Line and Flat creeks. This is in marked contrast to Whitewater Creek where overall development of ISA is less and no major loss of mussel species is observed.     

Metric-based reasoning about pseudocode design in the partial metrics system

The goal of the PMS project is to produce an environment in which the intelligent online assessment of the design for large-scale ADA programming projects is provided. The focus is on the representation of knowledge about the design process for an individual module. Changes in pseudocode complexity are measured in terms of partial metrics. These metrics can take the designers inferences about the pseudocode program structure into account when assessing module complexity. Next, a model of the stepwise refinement process is given which demonstrates how pseudocode elaboration decisions can be modelled in partial metric terms. Finally, the decisions associated with each refinement step for 17 example refinements taken from the computer science literature are described using partial metrics.     

Building a user model implicitly from a cooperative advisory dialog

This paper reviews existing methods for building user models to support adaptive, interactive systems, identifies sigificant problems with these approaches, and describes a new method for implicitly acquiring user models from an ongoing user-system dialog. Existing explicit user model acquisition methods, such as user edited models or model building dialogs put additional burden on the user and introduce artificial model acquisition dialogs. Hand coding stereotypes, another explicit acquisition method, is a tedious and error-prone process. On the other hand, implicit acquisition techniques such as computing presuppositions or entailments either draw too few inferences to be generally useful, or too many to be trusted.In contrast, this paper describes GUMAC, a General User Model Acquisition Component that uses heuristic rules to make default inferences about users' beliefs from their interaction with an advisory expert system. These rules are based on features of human action and conversation that constrain people's behavior and establish expectations about their knowledge. The application of these rules is illustrated with two examples of extended dialogs between users and an investment advisory system. During the course of these conversations, GUMAC is able to acquire an extensive model of the users' beliefs about the aspects of the domain considered in the dialog. These models, in turn, provide the sort of information needed by an explanation generator to tailor explanations the advisory system gives to its users.     

Metabotropic glutamate receptors are involved in long-term potentiation in isolated slices of rat medial frontal cortex

The prelimbic region of medial frontal cortex in the rat receives a direct input from the hippocampus and this functional connection is essential for aspects of spatial memory. Activity-dependent changes in the effectiveness of synaptic transmission in the medial frontal cortex, namely long-term potentiation (LTP) and long-term depression (LTD) can persist for tens of minutes or hours and may be the basis of learning and memory storage. Glutamatergic activation of ionotropic receptors is required to induce both LTP and LTD. We now present evidence of the involvement of metabotropic glutamate receptors in LTP in isolated slices of frontal cortex. Repetitive bursts of stimulation at theta frequencies (TBS) were applied to layer II, and monosynaptic EPSPs were monitored in layer V neurons of the prelimbic area. TBS was found to be more effective at inducing LTP than tetanic stimulation at 100 Hz and produced LTP that lasted >30 min in 8 out of 14 neurons. Tetanic stimulation at 100 Hz in the presence of the N-methyl--aspartate (NMDA)-antagonist 2-amino-5-phosphonopentanoate (AP5) was reported to be a reliable method of inducing LTD in prelimbic cortex (). However we found that this protocol did not facilitate the induction of LTD. The role of metabotropic glutamate receptors (mGluR) in LTP was assessed by using the selective, broad-spectrum antagonist (R, S)-alpha-methyl-4- carboxyphenylglycine (MCPG). This drug significantly reduced the incidence of LTP after TBS to only 1 of 14 neurons (P < 0.02, chi2 test). The pooled responses to TBS in MCPG showed significantly reduced potentiation [(P < 0.02, analysis of variance (ANOVA)]. The broad-spectrum mGluR agonist (1S, 3R)-1-aminocyclopentane-1,3-dicarboxylic acid (ACPD) and the selective group I agonist S-3 hydroxyphenylglycine(S-3HPG) both produced membrane depolarization, an increase in number of spikes evoked by depolarizing current pulses, and a reduction in the afterhyperpolarization. Similar effects were produced by these agonists even when synaptic transmission was blocked by use of the gamma-aminobutyric acid-B (GABAB) receptor agonist, 200 microM baclofen, which suggests that group I mGluRs are present on layer V neurons. We conclude that mGluRs participate in the production of LTP in prelimbic cortex, and that this excitatory effect could be mediated by the postsynaptic group I mGluRs.     

Assessing Environmental Risks: Lessons From Superfund

This essay analyzes the use of risk assessment in Superfund, the controversial American hazardous waste cleanup programme. We argue that risk assessment has been used in three ways in discussing policy options in this programme: as a metric for assessing performance; as a means for resolving conflicts; and as a tool for comparing different environmental initiatives. Use of risk reduction as an analytical tool in European efforts to clean up hazardous waste sites is discussed. We conclude that while risk assessment has potential utility for each of these applications, there are also accompanying technical and political difficulties.     

The US market for SO2 permits: Policy implications of the low price and trading volume

The price of SO₂ permits and the volume of trading under the US Acid Rain Program have been lower than expected. This can be explained by the creation and distribution of more permits than were initially authorized, by the sale of permits by high cost abaters who are subject to more stringent local emission constraints or who have irreversibly invested in high cost abatement technologies and by the deregulation of the natural gas and railroad industries which, in combination with incentives for cost-cutting under the new market approach to SO₂ control, has lowered marginal costs of abatement curves and made them more uniform across powerplants. The low price of permits and low trading volume are evidence that market approaches to pollution control can be more cost-effective than command and control regulations. The effect of public policies and technological changes on the allowance market are usefully examined in the context of an ideal market, in which the equilibrium price of allowances equals the marginal cost of abatement of individual powerplants. Using recent data from Coggins and Swinton (1996), we are able to explain the current price of permits with some accuracy.     

Combination calculi for uncertainty reasoning: representing uncertainty using distributions

There are many different methods for incorporating notions of uncertainty in evidential reasoning. A common component to these methods is the use of additional values, other than conditional probabilities, to assert current degrees of belief and certainties in propositions. Beginning with the viewpoint that these values can be associated with statistics of multiple opinions in an evidential reasoning system, we categorize the choices that are available in updating and tracking these multiple opinions. In this way, we develop a matrix of different uncertainty calculi, some of which are standard, and others are new. The main contribution is to formalize a framework under which different methods for reasoning with uncertainty can be evaluated. As examples, we see that both the “Kalman filtering” approach and the “Dempster–Shafer” approach to reasoning with uncertainty can be interpreted within this framework of representing uncertainty by the statistics of multiple opinions. This revised version was published online in June 2006 with corrections to the Cover Date.     

Assessing students' plans for college.

Based on a contemporary cognitive-psychoanalytic theory (control-mastery theory; J. Weiss, H. Sampson, & Mount Zion Psychotherapy Research Group, 1986), this study proposed that college students have plans for college that consist of conscious and unconscious goals and obstructions to be overcome in meeting those goals. The construct of unconscious guilt was used to mediate the dual goals of autonomy and attachment. The idiographic plan-formulation method was adapted to derive plans for 12 sophomore women. Acceptable interjudge reliabilities and criterion validity were demonstrated, and several themes in the goals and obstructions were illustrated. Students worried more about mothers than about fathers, particularly when they perceived the mother as weak or needy. The potential of the method for generating inferences about unconscious process for normative development is discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)