Use of collaborative techniques to promote learning in an environmental problem solving course

NR 206, Environmental Problem Solving and Impact assessment, is a senior-level course, the last in a sequence of seven CORE courses required of all students in our School of Natural Resources at The University of Vermont. These students represent seven different majors. Development and presentation of this course, which I began teaching in 1993, has proven to be the greatest teaching challenge I have faced in my 28+ years at the university. Although I have offered the course seven times (it is now offered both semesters), the course is still evolving; one of the major changes is that we now spend much more time in student collaborative (i.e., ‘group effort’) activities rather than in the typical ‘lecture-listen’ format. In this abstract, I briefly summarize the course content and some of its current activities

Seasonal occurrence of xylem embolism in sugar maple (Acer saccharum)

Journal ArticleXylem embolism, the reduction of water flow by air-filled vessels, was measured in a stand of 5- to 8-year-old sugar maple (Acer saccharum Marsh.) saplings growing in a nursery bed in northwestern Vermont. Embolism was quantified as percentage loss in hydraulic conductivity of trunk and branch segments relative to maximum values obtained by removing air from vessels by repeated high pressure (173 kPa) perfusions. Ten segments per tree were cut from 6 trees for each of 11 measurement periods spaced at roughly monthly intervals from May 1986 to June 1987

Programming Idioms for Transactional Events

Transactional events (TE) are an extension of Concurrent ML (CML), a programming model for synchronous message-passing. Prior work has focused on TE's formal semantics and its implementation. This paper considers programming idioms, particularly those that vary unexpectedly from the corresponding CML idioms. First, we solve a subtle problem with client-server protocols in TE. Second, we argue that CML's wrap and guard primitives do not translate well to TE, and we suggest useful workarounds. Finally, we discuss how to rewrite CML protocols that use abort actions

Simple model for tuberculosis in cattle and badgers

As an aid to the study of bovine tuberculosis (TB), a simple model has been developed of an epidemic involving two species, cattle and badgers. Each species may infect the other. The proportion of animals affected is assumed relatively small so that the usual nonlinear aspects of epidemic theory are avoided. The model is used to study the long-run and transient effect on cattle of culling badgers and the effect of a period without routine testing for TB, such as occurred during the 2001 epidemic of foot-and-mouth disease in Great Britain. Finally, by examining the changes in cattle TB over the last 15 years, and with some other working assumptions, it is estimated that the net reproduction number of the epidemic is 1.1. The implications for controlling the disease are discussed

Ariel - Volume 10 Number 3

Executive Editors Madalyn Schaefgen David Reich Business Manager David Reich News Editors Medical College Edward Zurad CAHS John Guardiani World Mark Zwanger Features Editors Meg Trexler Jim O\u27Brien Editorials Editor Jeffrey Banyas Photography and Sports Editor Stuart Singer Commons Editor Brenda Peterso

Risk of anemia with metformin use in type 2 diabetes:A MASTERMIND study

Objective: To evaluate the association between metformin use and anemia risk in type 2 diabetes, and the time-course for this, in a randomized controlled trial (RCT) and real-world population data. Research Design and Methods: Anemia was defined as a hemoglobin measure of <11 g/dL. In the RCTs A Diabetes Outcome Progression Trial (ADOPT; n = 3,967) and UK Prospective Diabetes Study (UKPDS; n = 1,473), logistic regression was used to model anemia risk and nonlinear mixed models for change in hematological parameters. In the observational Genetics of Diabetes Audit and Research in Tayside Scotland (GoDARTS) population (n = 3,485), discrete-time failure analysis was used to model the effect of cumulative metformin exposure on anemia risk. Results: In ADOPT, compared with sulfonylureas, the odds ratio (OR) (95% CI) for anemia was 1.93 (1.10, 3.38) for metformin and 4.18 (2.50, 7.00) for thiazolidinediones. In UKPDS, compared with diet, the OR (95% CI) was 3.40 (1.98, 5.83) for metformin, 0.96 (0.57, 1.62) for sulfonylureas, and 1.08 (0.62, 1.87) for insulin. In ADOPT, hemoglobin and hematocrit dropped after metformin initiation by 6 months, with no further decrease after 3 years. In UKPDS, hemoglobin fell by 3 years in the metformin group compared with other treatments. At years 6 and 9, hemoglobin was reduced in all treatment groups, with no greater difference seen in the metformin group. In GoDARTS, each 1 g/day of metformin use was associated with a 2% higher annual risk of anemia. Conclusions: Metformin use is associated with early risk of anemia in individuals with type 2 diabetes, a finding consistent across two RCTs and replicated in one real-world study. The mechanism for this early fall in hemoglobin is uncertain, but given the time course, is unlikely to be due to vitamin B12 deficiency alone

Intraoperative Monitoring of the Cochlear Nerve during Neurofibromatosis Type-2 Vestibular Schwannoma Surgery and Description of a "Test Intracochlear Electrode".

Objectives  A decision on whether to insert a cochlear implant can be made in neurofibromatosis 2 (NF2) if there is objective evidence of cochlear nerve (CN) function post vestibular schwannoma (VS) excision. We aimed to develop intraoperative CN monitoring to help in this decision. Design  We describe the intraoperative monitoring of a patient with NF2 and our stimulating and recording set up. A novel test electrode is used to stimulate the CN electrically. Setting  This study was set at a tertiary referral center for skull base pathology. Main outcome measure  Preserved auditory brainstem responses leading to cochlear implantation. Results  Electrical auditory brainstem response (EABR) waveforms will be displayed from different stages of the operation. A cochlear implant was inserted at the same sitting based on the EABR. Conclusion  Electrically evoked CN monitoring can provide objective evidence of CN function after VS excision and aid in the decision-making process of hearing rehabilitation in patients who will be rendered deaf

Temporal Modulation of Traveling Waves in the Flow Between Rotating Cylinders With Broken Azimuthal Symmetry

The effect of temporal modulation on traveling waves in the flows in two distinct systems of rotating cylinders, both with broken azimuthal symmetry, has been investigated. It is shown that by modulating the control parameter at twice the critical frequency one can excite phase-locked standing waves and standing-wave-like states which are not allowed when the system is rotationally symmetric. We also show how previous theoretical results can be extended to handle patterns such as these, that are periodic in two spatial direction.Comment: 17 pages in LaTeX, 22 figures available as postscript files from http://www.esam.nwu.edu/riecke/lit/lit.htm

Characterising the dynamics of cerebral metabolic dysfunction following traumatic brain injury: A microdialysis study in 619 patients.

Funder: National Institute for Health Research (NIHR)Traumatic brain injury (TBI) is a major cause of death and disability, particularly amongst young people. Current intensive care management of TBI patients is targeted at maintaining normal brain physiology and preventing secondary injury. Microdialysis is an invasive monitor that permits real-time assessment of derangements in cerebral metabolism and responses to treatment. We examined the prognostic value of microdialysis parameters, and the inter-relationships with other neuromonitoring modalities to identify interventions that improve metabolism. This was an analysis of prospective data in 619 adult TBI patients requiring intensive care treatment and invasive neuromonitoring at a tertiary UK neurosciences unit. Patients had continuous measurement of intracranial pressure (ICP), arterial blood pressure (ABP), brain tissue oxygenation (PbtO2), and cerebral metabolism and were managed according to a standardized therapeutic protocol. Microdialysate was assayed hourly for metabolites including glucose, pyruvate, and lactate. Cerebral perfusion pressure (CPP) and cerebral autoregulation (PRx) were derived from the ICP and ABP. Outcome was assessed with the Glasgow Outcome Score (GOS) at 6 months. Relationships between monitoring variables was examined with generalized additive mixed models (GAMM). Lactate/Pyruvate Ratio (LPR) over the first 3 to 7 days following injury was elevated amongst patients with poor outcome and was an independent predictor of ordinal GOS (p70mmHg, PRx 18mmHg, and brain glucose >1mM. Deranged cerebral metabolism is an important determinant of patient outcome following TBI. Variations in cerebral perfusion, oxygenation and glucose supply are associated with changes in cerebral LPR and suggest therapeutic interventions to improve cerebral metabolism. Future prospective studies are required to determine the efficacy of these strategies