What a Difference in Pressure Makes! A Framework Describing Undergraduate Students' Reasoning about Bulk Flow Down Pressure Gradients.

Pressure gradients serve as the key driving force for the bulk flow of fluids in biology (e.g., blood, air, phloem sap).

Undergraduate students' neurophysiological reasoning: what we learn from the attractive distractors students select.

The basis for mastering neurophysiology is understanding ion movement across cell membranes. The Electrochemical Gradients Assessment Device (EGAD) is a 17-item test assessing students' understanding of fundamental concepts of neurophysiology, e.g.

Oaks to arteries: the Physiology Core Concept of flow down gradients supports transfer of student reasoning.

The Physiology Core Concept of flow down gradients is a major concept in physiology, as pressure gradients are the key driving force for the bulk flow of fluids in biology. However, students struggle to understand that this principle is foundational to the mechanisms governing bulk flow across diverse physiological systems (e.g.

A new assessment to monitor student performance in introductory neurophysiology: Electrochemical Gradients Assessment Device.

The basis for understanding neurophysiology is understanding ion movement across cell membranes. Students in introductory courses recognize ion concentration gradients as a driving force for ion movement but struggle to simultaneously account for electrical charge gradients. We developed a 17-multiple-choice item assessment of students' understanding of electrochemical gradients and resistance in neurophysiology, the Electrochemical Gradients Assessment Device (EGAD).

Magellanic penguin telomeres do not shorten with age with increased reproductive effort, investment, and basal corticosterone.

All species should invest in systems that enhance longevity; however, a fundamental adult life-history trade-off exists between the metabolic resources allocated to maintenance and those allocated to reproduction. Long-lived species will invest more in reproduction than in somatic maintenance as they age. We investigated this trade-off by analyzing correlations among telomere length, reproductive effort and output, and basal corticosterone in Magellanic penguins ().

Telomeres shorten and then lengthen before fledging in Magellanic penguins ().

For all species, finite metabolic resources must be allocated toward three competing systems: maintenance, reproduction, and growth. Telomeres, the nucleoprotein tips of chromosomes, which shorten with age in most species, are correlated with increased survival. Chick growth is energetically costly and is associated with telomere shortening in most species.