Inter- and intraspecific comparisons of antiherbivore defenses in three species of rainforest understory shrubs.

Plants defend themselves against herbivores and pathogens with a suite of morphological, phenological, biochemical, and biotic defenses, each of which is presumably costly. The best studied are allocation costs that involve trade-offs in investment of resources to defense versus other plant functions. Decreases in growth or reproductive effort are the costs most often associated with antiherbivore defenses, but trade-offs among different defenses may also occur within a single plant species. We examined trade-offs among defenses in closely related tropical rain forest shrubs (Piper cenocladum, P. imperiale, and P. melanocladum) that possess different combinations of three types of defense: ant mutualists, secondary compounds, and leaf toughness. We also examined the effectiveness of different defenses and suites of defenses against the most abundant generalist and specialist Piper herbivores. For all species examined, leaf toughness was the most effective defense, with the toughest species, P. melanocladum, receiving the lowest incidence of total herbivory, and the least tough species, P. imperiale, receiving the highest incidence. Although variation in toughness within each species was substantial, there were no intraspecific relationships between toughness and herbivory. In other Piper studies, chemical and biotic defenses had strong intraspecific negative correlations with herbivory. A wide variety of defensive mechanisms was quantified in the three Piper species studied, ranging from low concentrations of chemical defenses in P. imperiale to a complex suite of defenses in P. cenocladum that includes ant mutualists, secondary metabolites, and moderate toughness. Ecological costs were evident for the array of defensive mechanisms within these Piper species, and the differences in defensive strategies among species may represent evolutionary trade-offs between costly defenses.

Synergistic effects of three Piper amides on generalist and specialist herbivores.

The tropical rainforest shrub Piper cenocladum, which is normally defended against herbivores by a mutualistic ant, contains three amides that have various defensive functions. While the ants are effective primarily against specialist herbivores, we hypothesized that these secondary compounds would be effective against a wider range of insects, thus providing a broad array of defenses against herbivores. We also tested whether a mixture of amides would be more effective against herbivores than individual amides. Diets spiked with amides were offered to five herbivores: a naïve generalist caterpillar (Spodoptera frugiperda), two caterpillar species that are monophagous on P. cenocladum (Eois spp.), leaf-cutting ants (Atta cephalotes), and an omnivorous ant (Paraponera clavata). Amides had negative effects on all insects, whether they were naïve, experienced, generalized, or specialized feeders. For Spodoptera, amide mixtures caused decreased pupal weights and survivorship and increased development times. Eois pupal weights, larval mass gain, and development times were affected by additions of individual amides, but increased parasitism and lower survivorship were caused only by the amide mixture. Amide mixtures also deterred feeding by the two ant species, and crude plant extracts were strongly deterrent to P. clavata. The mixture of all three amides had the most dramatic deterrent and toxic effects across experiments, with the effects usually surpassing expected additive responses, indicating that these compounds can act synergistically against a wide array of herbivores.

Scholarship in teaching: an imperative for the 21st century.

At some medical schools broader definitions of scholarship have emerged along with corresponding changes in their academic reward systems. Such situations are not common, however. The definition of scholarship generally applied by medical schools is unnecessarily narrow and excludes areas of legitimate academic activity and productivity that are vital to the fulfillment of the school's educational mission. The authors maintain that creative teaching with effectiveness that is rigorously substantiated, educational leadership with results that are demonstrable and broadly felt, and educational methods that advance learners' knowledge are consistent with the traditional definition of scholarship. Faculty whose educational activities fulfill the criteria above are scholars and must be recognized by promotion. The authors specifically address scholarship in education, focusing on teaching and other learning-related activities rather than on educational research, which may be assessed and rewarded using the same forms of evidence as basic science or clinical research. They build on Boyer's work, which provides a vocabulary for discussing the assumptions and values that underlie the roles of faculty as academicians. Next, they apply Glassick et al.'s criteria for judging scholarly work to faculty members' educational activities to establish a basis for recognition and reward consistent with those given for other forms of scholarship. Finally, the authors outline the organizational infrastructure needed to support scholars in education.

Grade inflation in internal medicine clerkships: results of a national survey.

BACKGROUND: There has been a discussion among medical educators concerning grade inflation; however, little has been written about it in the medical education literature. PURPOSE: A survey was developed to determine if grade inflation exists by gathering data about grading practices and by gathering the opinions of course directors from Internal Medicine clerkships. METHODS: The survey was administered during the 1996-1997 academic year to all 125 LCME accredited medical school Internal Medicine Clerkship Directors. Grading practices for 3 separate academic years were obtained plus responses to questions about causes of and solutions for grade inflation. RESULTS: Eighty-three surveys were returned for a 66% response rate. There was a trend towards higher grades across the 3 study years, with the 1995-1996 year being statistically significant. Forty-eight percent of the clerkship directors felt that grade inflation existed in their courses, and 43% felt that some students passed who should have failed. CONCLUSION: Statistically significant grade inflation exists in Internal Medicine clerkships. Most disturbingly, 43% feel we are unable appropriately to identify incompetent students.

A longitudinal ethics curriculum for medical students and generalist residents at the Medical College of Georgia.

Medical ethics is an important instructional area for both the undergraduate student pursuing a generalist education and generalist residents. With the support of a Generalist Physician Initiative (GPI) award from The Robert Wood Johnson Foundation, the Medical College of Georgia has implemented a longitudinal experience in clinical ethics spanning the four undergraduate years to make this area more meaningful and clinically relevant. This report outlines the structure and content of this four-year curriculum, which has been developed and implemented in a stepwise fashion since 1996. Course themes and students' activities during the four years are described. Since 1997, a shared curriculum in ethics--developed for residents in internal medicine, family medicine, and pediatric generalist programs--has been provided in combined interdepartmental conferences as part of a broader interdepartmental generalist curriculum. Early evaluation findings and plans for future evaluation programs are also described.

Making a case for the teaching scholar.

Medical schools are increasingly cognizant of their inability to critically evaluate faculty who support the core mission of education. To address this need, the Project on Scholarship was initiated by the Group on Educational Affairs (GEA) of the Association of American Medical Colleges. Building on and expanding previous definitions of scholarship and the associated criteria emerging in higher education, the project developed a set of "teacher as scholar" scenarios. These scenarios contained varied types of evidence for teaching scholarship and were discussed at the 1999 GEA regional meetings. Two major conclusions/recommendations emerged from these discussions: (1) the use of commonly accepted scholarship criteria (clear goals, appropriate methods, significant results, effective communication) provides a framework for identifying the types of evidence needed to document teaching scholarship, and (2) medical schools must create an infrastructure for promoting educational scholarship. This infrastructure must support the reliable and valid collection of evidence of educational scholarship and the continuous development of faculty as teaching scholars.

Why students choose a primary care or nonprimary care career. The Specialty Choice Study Group.

PURPOSE: To analyze the factors influencing students to choose residency training in primary care (internal medicine, family medicine, and pediatrics) or nonprimary care specialties and study the combined effect of reported responses on their choice. MATERIALS AND METHODS: A 12-item questionnaire using a 7-point Likert scale was mailed to the 1,164 graduating seniors from 9 medical schools in 1991. Responses ranged from 1, very negative influence, to 7, very positive influence. Four indicated no influence. The overall response rate was 69%. Univariate analysis of factors associated with specialty choice was done with the Mantel-Haenzsel chi-square test. Odds ratios were calculated for each significant variable without controlling for other variables. Factors found to have univariate significance were then tested for combined significance with logistic regression analysis. The regression was performed on a randomly chosen training sample, and validated on a test sample. RESULTS: Forty-five percent of respondents chose an internship and planned residency training in a primary care specialty. Factors that remained positively associated with choosing a primary care specialty when controlling for other factors were desire to provide comprehensive care, to keep options open, and to undertake ambulatory care. Desire for monetary reward was negatively associated with choice of a primary care specialty. CONCLUSIONS: Positive educational experiences in the ambulatory setting should be enhanced, and disparity in remuneration among disciplines reduced.

Learning, experience, and self-assessment of competence of third-year medical students in performing bedside procedures.

BACKGROUND: Third-year medical students are expected to perform common bedside procedures as part of their daily ward activities, but there are few programs to teach these skills or document students' abilities to perform them. PURPOSE: In addition to describing the clinical procedures course at the Medical College of Georgia School of Medicine, the purpose of this paper is to report how often students perform common bedside procedures during the third year of medical school, whether the number of times a procedure has been performed is indicative of self-perceived level of competence, and how useful the students find the procedures course for learning how to perform common procedures. METHOD: In June 1991, the 163 entering third-year students participated in a two-day course in which they were taught universal precautions and provided specific step-by-step instructions for performing 16 clinical procedures. One year later, after the students had completed their third-year clerkships, they were asked to report the numbers of times they had performed the procedures during their clerkships, to provide self-assessments of their competency, and to indicate how helpful the course had been for learning clinical procedures. The association between the number of times the students reported performing a procedure and how competent they felt to perform the procedure was assessed using Kendall's tau coefficient. RESULTS: A total of 100 students returned completed questionnaires. Most of the students reported performing venipuncture, obtaining blood cultures, and scrubbing surgically more than five times, but they reported performing other procedures less frequently. For most procedures, self-assessment of competency correlated with frequency of performance. The procedures course was well received by students and instructors, based on both written evaluations and informal verbal feedback. CONCLUSION: Surprisingly, the students' self-reports indicated that many students performed procedures on patients infrequently. As expected, for most procedures there was a significant association between frequency of performance and self-assessed competency.

Specialty choice: development of a questionnaire.

Determination of factors which influence medical students' choice of a specialty is potentially important for decisions regarding medical school curricular changes that might influence students' specialty choice. Beginning in 1988, we developed and annually revised a specialty choice questionnaire which was administered to the senior class at the Medical College of Georgia School of Medicine from 1988 to 1991. This paper presents reliability and validity data regarding the questionnaire. Validation procedures involved driving a multiple discriminant function to determine the significance of relationships between a variable and choice of a primary care (PC) or non-primary care (NPC) specialty. Structure coefficients for the multiple discriminant functions that were statistically and practically significant were desire for longitudinal patient care opportunities and desire for monetary rewards. Estimates of internal consistency were derived using Cronbach's alpha. Cronbach's alpha coefficients for this item set were 0.71, 0.59 and 0.46 for 1988, 1989 and 1990 respectively. Test-retest coefficients for the 1991 12-item questionnaire ranged from 0.51 to 0.81.