Inconceivable: assessment of teaching at the university level.

Although most colleges and universities use a scholarly, multifaceted, and data-rich methodology to evaluate a faculty member's research, by comparison they are quite lacking in the way they evaluate teaching. We share advice from education experts for guidance at designing an ideal process "to evaluate teaching productivity as seriously as we do research" as well as an outline of a teaching rubric used to evaluate university faculty members.

Is CFTR an exchanger?: Regulation of HCO3 -Transport and extracellular pH by CFTR.

The disease, cystic fibrosis, is caused by the malfunction of the cystic fibrosis transmembrane conductance regulator. Expression of functional CFTR may normally regulate extracellular pH via control of bicarbonate efflux. Reports also suggest that the CFTR may be a Cl-/HCO3- exchanger. If true, this could be very important for treatment of CF given the airway host defense system is quite sensitive to pH, and acidic pH been found to increase mucus viscosity. We compared evidentiary support of four possible models of CFTR's role in the transport of bicarbonate: 1) CFTR as a Cl-channel that permits bicarbonate conductance, 2) CFTR as an anion Cl-/HCO3- exchanger (AE), 3.) CFTR as both a Cl-channel and an AE, and 4.) CFTR as a Cl-channel that allows for transport of bicarbonate and regulates an independent AE. The effect of stimulators and inhibitors of CFTR and AEs were evaluated via iodide efflux and studies of extracellular pH. This data, as well as that published by others, suggest that while CFTR may support and regulate bicarbonate flux it is unlikely it directly performs Cl-/HCO3- anion exchange.

Undergraduate teaching assistants can provide support for reformed practices to raise student learning.

Graduate students who serve as teaching assistants are a critical part of STEM (science, technology, engineering, mathematics) education and research at large universities in the U.S. Yet just like faculty, graduate students are not immune to the publish or perish paradigm, which can compete with one's dedication to teaching. While in recent years many STEM faculty members have become aware of how well undergraduates can assist instructors in their teaching, many, if not most, university faculty still teach in traditional settings, where graduate students are the norm and use of undergraduates is a completely unexploited opportunity. Undergraduates can serve as effective teaching assistants and may bring unique skills and experience to undergraduate instruction not held by graduate students. Undergraduate teaching assistants (UTAs) can provide additional support for reformed practices, which raise student learning. Based on cost, prior experience and success as students in same course, and shared vision with professors, a number of institutions have initiated UTA programs and reported increased student learning. The audience of this paper is faculty who are not familiar with the use of UTAs in university teaching, and the purpose is to review the literature on UTAs, contrast the contributions of UTAs and graduate teaching assistants, and examine the potential value of UTAs in undergraduate education.

Integrating Concepts in Biology Textbook Increases Learning: Assessment Triangulation Using Concept Inventory, Card Sorting, and MCAT Instruments, Followed by Longitudinal Tracking.

The purpose of this study was to examine the educational impact of an intervention, the inquiry-focused textbook Integrating Concepts in Biology (ICB), when used in a yearlong introductory biology course sequence. Student learning was evaluated using three published instruments: 1) The Biology Concept Inventory probed depth of student mastery of fundamental concepts in organismal and cellular topics when confronting misconceptions as distractors. ICB students had higher gains in all six topic categories (+43% vs. peers overall, p < 0.01). 2) The Biology Card Sorting Task assessed whether students organized biological ideas more superficially, as novices do, or based on deeper concepts, like experts. The frequency with which ICB students connected deep-concept pairs, or triplets, was similar to peers; but deep understanding of structure/function was much higher (for pairs: 77% vs. 25%, p < 0.01). 3) A content-focused Medical College Admission Test (MCAT) posttest compared ICB student content knowledge with that of peers from 15 prior years. Historically, MCAT performance for each semester ranged from 53% to 64%; the ICB cohort scored 62%, in the top quintile. Longitudinal tracking in five upper-level science courses the following year found ICB students outperformed peers in physiology (85% vs. 80%, p < 0.01).

Chemical rescue of ΔF508-CFTR in C127 epithelial cells reverses aberrant extracellular pH acidification to wild-type alkalization as monitored by microphysiometry.

Cystic fibrosis (CF) is caused by mutations in the gene for CFTR, a cAMP-activated anion channel expressed in apical membranes of wet epithelia. Since CFTR is permeable to HCO3(-), and may regulate bicarbonate exchangers, it is not surprising evidence of changes in extracellular pH (pHo) have been found in CF. Previously we have shown that tracking pHo can be used to differentiate cells expressing wild-type CFTR from controls in mouse mammary epithelial (C127) and fibroblast (NIH/3T3) cell lines. In this study we characterized forskolin-stimulated extracellular acidification rates in epithelia where chemical correction of mutant ΔF508-CFTR converted an aberrant response in acidification (10%+ increase) to wild-type (25%+ decrease). Thus treatment with corrector (10% glycerol) and the resulting increased expression of ΔF508-CFTR at the surface was detected by microphysiometry as a significant reversal from acidification to alkalization of pHo. These results suggest that CFTR activation as well as correction can be detected by carefully monitoring pHo and support findings in the field that extracellular pH acidification may impact the function of airway surface liquid in CF.

Verbal final exam in introductory biology yields gains in student content knowledge and longitudinal performance.

We studied gains in student learning over eight semesters in which an introductory biology course curriculum was changed to include optional verbal final exams (VFs). Students could opt to demonstrate their mastery of course material via structured oral exams with the professor. In a quantitative assessment of cell biology content knowledge, students who passed the VF outscored their peers on the medical assessment test (MAT), an exam built with 40 Medical College Admissions Test (MCAT) questions (66.4% [n = 160] and 62% [n = 285], respectively; p < 0.001);. The higher-achieving students performed better on MCAT questions in all topic categories tested; the greatest gain occurred on the topic of cellular respiration. Because the VF focused on a conceptually parallel topic, photosynthesis, there may have been authentic knowledge transfer. In longitudinal tracking studies, passing the VF also correlated with higher performance in a range of upper-level science courses, with greatest significance in physiology, biochemistry, and organic chemistry. Participation had a wide range but not equal representation in academic standing, gender, and ethnicity. Yet students nearly unanimously (92%) valued the option. Our findings suggest oral exams at the introductory level may allow instructors to assess and aid students striving to achieve higher-level learning.

Less teaching, more learning: 10-yr study supports increasing student learning through less coverage and more inquiry.

In this study, we compared gains in student content learning over a 10-yr period in which the introductory biology laboratory curriculum was changed in two ways: an increase of inquiry and a reduction of content. Three laboratory formats were tested: traditional 1-wk-long cookbook laboratories, two 7-wk-long inquiry laboratories, and one 14-wk-long inquiry laboratory. As the level of inquiry increased, student learning gains on content exams trended upward even while traditional content coverage taught decreased. In a quantitative assessment of content knowledge, students who participated in the 14-wk-long inquiry laboratory format outscored their peers in both 7- and 1-wk-long lab formats on Medical College Admissions Test exam questions (scores of 64.73%, 61.97%, and 53.48%, respectively, P < 0.01). In a qualitative study of student opinions, surveys conducted at the end of semesters where traditional 1-wk laboratories (n = 167 students) were used had low response rates and predominately negative opinions (only 20% of responses were positive), whereas those who participated in 7-wk (n = 543) or 14-wk (n = 308) inquiry laboratories had high response rates and 71% and 96% positive reviews, respectively. In an assessment of traditional content coverage in courses, three indexes were averaged to calculate traditional forms of coverage and showed a decrease by 44% over the study period. We believe that the quantitative and qualitative data support greater student-driven inquiry in the classroom laboratory, which leads to deeper learning in fewer topic areas (less teaching) and can reap gains in scientific thinking and fundamental understanding applicable to a broader range of topic areas (more learning) in introductory biology.

Pseudomonas or LPS exposure alters CFTR iodide efflux in 2WT2 epithelial cells with time and dose dependence.

The most common heritable genetic disease in the United States, cystic fibrosis (CF), is caused by mutations in the CF transmembrane conductance regulator (CFTR), a chloride channel that interacts with and regulates a number of other proteins. The bacteria Pseudomonas aeruginosa infects 80% of patients causing decreased pulmonary function and life expectancy. It is not known how malfunction of the chloride channel allows for preferential colonization of patients by a single pathogen. The hypothesis that CFTR interacts with toll-like receptor 4 (TLR4) to phagocytize bacteria was tested. A competitive antagonist of TLR4, MKLPS, was studied for its effect in gentamicin-protection-based bacterial invasion assays. Pre-incubation (15 min 50 microg/mL) with MKLPS did not alter the rate of phagocytosis of P. aeruginosa by cultured epithelia. However, further studies with GFP-transfected P. aeruginosa revealed prominent antibiotic resistant microcolonies were formed. If CFTR is involved in phagocytosis of the bacteria, then internalization was predicted to decrease in iodide efflux. Surprisingly, cultured epithelia exposed to P. aeruginosa for 15 min showed increased cAMP-activated iodide efflux through CFTR. In addition, 15-min exposure to bacterial cell wall component, LPS, purified from P. aeruginosa also increased CFTR iodide efflux in a dose-dependent manner (50, 100 and 200 microg/mL LPS had 25%, 37% and 47% increase). In a reversal of this phenomenon, shorter 5-min exposure to 100 microg/mL LPS resulted in a 25% decrease in forskolin-activated CFTR channel activity compared to controls. This data is consistent with a model in which CFTR is removed from the plasma membrane during phagocytosis of P. aeruginosa followed by recruitment of channels to the membrane to replace those removed during phagocytosis. More studies are needed to confirm this model, but this is the first report of a bacterial product causing a biphasic time-dependent and a dose-dependent alteration of CFTR channel activity.

Direct measurement of acid efflux from isolated guinea pig pancreatic ducts.

OBJECTIVES: The current studies used the technique of microphysiometry to directly determine the effects of stimulators and inhibitors of pancreatic duct secretion on acid efflux from isolated pancreatic ducts. METHODS: Main and interlobular ducts were isolated from guinea pig pancreata by collagenase digestion and manual selection. Segments were placed in the chambers of a microphysiometer, which uses a silicon chip-based, light-addressable potentiometric sensor to determine the proton concentration in the superfusing solution. Isolated ducts were superfused with a low buffer capacity Ringer's solution at 37 degrees C and the extracellular acidification rate (EAR) was determined by computer-directed protocols. RESULTS: A survey of potential agonists demonstrated that both secretin and the cholinomimetic, carbachol, dramatically increased EAR, with EC50 of 3 nmol/L and 0.6 mumol/L, respectively. The changes in EAR induced by both secretagogues were rapid, peaking within 4-6 minutes, and then declining to a level below the peak but above basal EAR. The enhanced EAR was maintained for at least 30 minutes in the presence of either secretagogue. More modest increases in EAR were evoked by bombesin, substance P, and vasoactive intestinal peptide (VIP). Cholecystokinin and isoproterenol caused no significant change in pancreatic duct EAR. A combination of amiloride and bafilomycin A1, inhibitors, respectively, of Na/H exchange and of vacuolar type H-ATPase activity, caused a dramatic drop in EAR but did not fully inhibit the increase in EAR elicited by carbachol, suggesting that other mechanisms may contribute to agonist-stimulated EAR of pancreatic ducts. CONCLUSIONS: Thus, the results support the use of microphysiometry as a tool to study pancreatic duct physiology and in particular a method to measure acid efflux from the serosal surface.

Infusion of collaborative inquiry throughout a biology curriculum increases student learning: a four-year study of "Teams and Streams".

Are traditional laboratories in the core introductory biology courses teaching physiology majors the art and trade of science, or simply leaving them with a memory of trivial experiments done for unknown reasons? Our students, a population dominated by pre-med and physiology majors, think the latter and have encouraged us to challenge this model, and it turns out scientists and education researchers agree with our students (4, 31, 32). In an effort to remedy this, we began a long-term redesign of the introductory biology sequence to become what is now a sequence of inquiry laboratories we term "Teams and Streams" (TS). In these TS inquiry labs, student research teams pose a scientific question/hypothesis, propose an experimental design, perform multi-week investigations and then present their findings in various forms (web, interviews, and papers). The response to this classroom laboratory design has been overwhelmingly positive. In a qualitative study of student opinion (where 260 student responses were studied), surveys conducted at the end of semesters where traditional scripted labs were used (n = 70 comments) had predominantly negative opinions (80% negative responses), whereas the reverse was true for students (n = 190 comments) who participated in courses using the TS inquiry labs (78% positive responses). In a quantitative assessment of content knowledge, students who participated in new TS inquiry labs (n = 245) outscored their peers in traditional labs (n = 86) on Medical College Admission Test-style standardized exams (59.3 +/- 0.8% vs. 48.9 +/- 1.3%, respectively; P < 0.0001). We believe these quantitative data support the qualitative findings and suggest the TS inquiry lab approach increases student learning.

Extracellular acidification parallels insulin secretion in INS-1 and HIT-T15 beta-cell lines.

As an alternative to manual assays that track insulin secretion, we tested a silicon-based biosensor that allows automated monitoring of extracellular acidification. Glucose stimulation of INS-1 and HIT-T15 cells resulted in a rapid increase in extracellular acidification in a biphasic and concentration-dependent fashion much like insulin secretion (EC(50) INS-1=5 mM and HIT-T15=1 mM). This response was attenuated by verapamil (10 microM) and stimulated by administration of glybenclamide (100 nM) or KCl-induced (40 mM) depolarization. These experiments suggest that automated monitoring of extracellular pH may be a useful assay and support the relevance of linking metabolic activity to insulin secretion.