Hypoxic pulmonary vasoconstriction is/is not mediated by increased production of reactive oxygen species.
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Animals↗
Biomedical subjects
Nancy J Pelaez
Publications and source records attributed to Nancy J Pelaez.
Prevalence of blood circulation misconceptions among prospective elementary teachers.
Research shows that misconceptions about human blood circulation and gas exchange persist across grade levels. The purpose of this study was twofold: 1) to investigate the prevalence and persistence of blood circulation misconceptions among prospective elementary teachers and 2) to evaluate the effectiveness of learning activities for discovering what students know and can explain about blood circulation and lung function. The context was an undergraduate introduction to biology course taught by two professors across three semesters at a state university. Independent reviewers identified five categories of erroneous ideas about blood circulation. Many categories still presented problems to students at the end of the course: 70% of prospective elementary teachers did not understand the dual blood circulation pathway, 33% were confused about blood vessels, 55% had wrong ideas about gas exchange, 19% had trouble with gas transport and utilization, and 20% did not understand lung function. Results show that an interview about a drawing as a final exam was significantly better at revealing different errors and a higher frequency of erroneous ideas compared with an essay exam. There is an urgent need for instructional tools to help undergraduate students realize the discrepancies between their own ideas about blood circulation and those of the scientific community.
Adolescent↗
Problem-based writing with peer review improves academic performance in physiology.
The aim of this study was to determine whether problem-based writing with peer review (PW-PR) improves undergraduate student performance on physiology exams. Didactic lectures were replaced with assignments to give students practice explaining their reasoning while solving qualitative problems, thus transferring the responsibility for abstraction and generalization to the students. Performance on exam items about concepts taught using PW-PR was compared with performance on concepts taught using didactic lectures followed by group work. Calibrated Peer Review, a Web-delivered program, was used to collect student essays and to manage anonymous peer review after students "passed" three calibration peer reviews. Results show that the students had difficulty relating concepts. Relationship errors were categorized as (1) problems recognizing levels of organization, (2) problems with cause/effect, and (3) overgeneralizations. For example, some described cells as molecules; others thought that vesicles transport materials through the extracellular fluid. With PW-PR, class discussion was used to confront and resolve such difficulties. Both multiple-choice and essay exam results were better with PW-PR instead of lecture.
Educational Measurement↗
Sharing science: characteristics of effective scientist-teacher interactions.
Despite national guidelines to reform K-12 science education, our students are not learning science any better. Conducted under the auspices of the American Association for the Advancement of Science, a symposium examined several programs where professional scientists interact with classroom teachers to improve science education. Symposium participants described their projects and discussed the factors that contribute or detract from each project's success. The events of this symposium are critically analyzed. Four themes emerged as issues that affect the successful implementation and continuation of science education reform projects: scientific literacy as a primary goal, personal characteristics and commitment of project partners, curricular change built on social and developmental goals, and the incentive/reward structures in universities and school systems. This review of the emergent themes places the opinions of the symposium participants into the larger context of a growing science education research literature to inform others about synergy between professional scientists and classroom teachers. Our aim is to help others learn about the characteristics of effective partnerships to improve science education.
Cooperative Behavior↗
Gender dichotomy in reactivity to the vasoactive oxidant hydrogen peroxide in spontaneously hypertensive rats.
OBJECTIVES: To determine: 1) whether ovariectomy increases low-density lipoprotein (LDL) cholesterol; 2) if increased LDL cholesterol correlates with increased blood pressure; and 3) whether arterial muscle reactivity to the vasoactive oxidant hydrogen peroxide (H2O2) is gender-dependent in spontaneously hypertensive rats (SHR) and normotensive Wistar-Kyoto rats (WKY). METHODS: SHR and WKY females were ovariectomized at four weeks of age. Blood pressures were monitored weekly. Blood was collected at the time of sacrifice at 16-18 weeks, and caudal arteries were excised. LDL cholesterol was measured. Caudal arterial muscle was contracted with high-calcium egtazic acid (EGTA)/ionomycin (calcium ionophore) and relaxed with zero-calcium EGTA/ionomycin. H2O2-induced contractions were elicited in zero calcium. H2O2 reactivity was compared for SHR and WKY, male and female arterial muscle. RESULTS: Ovariectomy increased LDL cholesterol in both SHR and WKY but blood pressure increased only in SHR. Male SHR and WKY arterial muscle was more reactive to H2O2 compared with female preparations. CONCLUSION: Gender dichotomy in the development of hypertension does not appear to be due directly to the LDL-lowering effects of estrogen but is likely due, at least in part, to lower arterial reactivity to vasoactive oxidants, such as H2O2, with a consequent reduction of oxidant-induced vasoconstriction in female SHR.
Animals↗