Maternal age effects on offspring lifespan and reproduction vary within a species.

Across diverse taxa, offspring from older mothers have decreased lifespan and fitness. Little is known about the extent to which maternal age effects vary among genotypes for a given species, however, except for studies of a few arthropod species. To investigate the presence and degree of intraspecific variability in maternal age effects, we compared lifespan, reproductive schedule, and lifetime reproductive output of offspring produced by young, middle-aged, and old mothers in four strains of rotifers in the Brachionus plicatilis species complex. We found significant variability among strains in the magnitude and direction of maternal age effects on offspring life history traits. In one strain, offspring of young mothers lived 20% longer than offspring of old mothers, whereas there were no significant effects of maternal age on lifespan for other strains. Depending on strain, advanced maternal age had positive effects, negative effects, or no effect on lifetime reproductive output. Across strains, older mothers produced offspring that had higher maximum daily reproduction early in life. The effects of maternal age on offspring vital rates could not be explained by changes in trade-offs between lifespan and reproduction. This study documents intraspecific variability in maternal age effects in an additional clade. Investigating intraspecific variability is critical for understanding the ubiquity of maternal age effects and their role in the evolution of life history and aging.

Maternal age effects on offspring lifespan and reproduction vary within a species.

Across diverse taxa, offspring from older mothers have decreased lifespan and fitness. Little is known about whether such maternal age effects vary among genotypes for a given species, however. We compared maternal age effects among four strains of rotifers in the Brachionus plicatilis species complex. For each strain, we measured lifespan, reproductive schedule, and lifetime reproductive output of offspring produced by young, middle-aged, and old mothers. We found unexpected variability among strains in the magnitude and direction of maternal age effects on offspring life history traits. In one strain, offspring of young mothers lived 20% longer than offspring of old mothers, whereas there were no significant effects of maternal age on lifespan for the other strains. Across strains, advanced maternal age had positive effects, negative effects, or no effect on lifetime reproductive output. For all but one strain, older mothers produced offspring that had higher maximum daily reproduction early in life. Maternal age effects appear to be genetically determined traits, not features of life history strategy or due to accumulation of age-related damage in the germline. Investigating intraspecific variability is critical for understanding the ubiquity of maternal age effects and their role in the evolution of life history and aging.

Multigenerational Life-History Responses to pH in Distinct Populations of the Copepod Tigriopus californicus.

Intertidal zones are highly dynamic and harsh habitats: organisms that persist there must face many stressors, including drastic changes in seawater pH, which can be strongly influenced by biological processes. Coastal ecosystems are heterogeneous in space and time, and populations can be exposed to distinct selective pressures and evolve different capacities for acclimation to changes in pH. Tigriopus californicus is a harpacticoid copepod found in high-shore rock pools on the west coast of North America. It is a model system for studying population dynamics in diverse environments, but little is known about its responses to changes in seawater pH. I quantified the effects of pH on the survivorship, fecundity, and development of four T. californicus populations from San Juan Island, Washington, across three generations. For all populations and generations, copepod cultures had lower survivorship and delayed development under extended exposure to higher pH treatments (pH 7.5 and pH 8.0), whereas cultures maintained in lower pH (7.0) displayed stable population growth over time. Reciprocal transplants between treatments demonstrated that these pH effects were reversible. Life histories were distinct between populations, and there were differences in the magnitudes of pH effects on development and culture growth that persisted through multiple generations. These results suggest that T. californicus might not have the generalist physiology that might be expected of an intertidal species, and it could be adapted to lower average pH conditions than those that occur in adjacent open waters.

How Assumptions and Preferences Can Affect Patient Care: An Introduction to Implicit Bias for First-Year Medical Students.

Introduction: Instruction in implicit bias is becoming prevalent across the spectrum of medical training. Little education exists for preclinical students, and guidance for faculty to facilitate such education is minimal. To address these gaps, we designed and delivered a single session for incoming first-year medical students and developed a facilitator training program. Methods: One faculty member delivered a 1-hour, multimedia, interactive lecture to all first-year medical students. Students subsequently met in small groups with trained facilitators. Activities included reflection, guided debriefing, and strategy identification to become aware of when they might be making an assumption causing them to jump to a conclusion about someone. The program evaluation consisted of aggregated student strategies and facilitator feedback during postsession debriefs, both analyzed through thematic analysis. Results: We delivered instruction to 1,098 students. Student strategies resulted in three themes: (1) humility, (2) reflection, and (3) partnering. The postsession debriefs uncovered opportunities to enhance the session. Lessons learned included presenting material to an entire class at once, allowing students to engage in dynamic discussion in the small groups, eliminating anonymous polling in the small groups, and highlighting management of implicit bias as essential to professional development. Discussion: Our instructional design enabled first-year medical students to identify at least one strategy to use when implicit biases are activated. The large-group session was deliverable by one faculty member, and volunteers successfully facilitated small-group sessions after only one training session, making this model a feasible innovation to reach an entire medical school class at the same time.

How to Make or Break Implicit Bias Instruction: Implications for Curriculum Development.

PURPOSE: To analyze faculty experiences regarding facilitating discussions as part of the institution's curriculum on racial and ethnic implicit bias recognition and management. METHOD: Between July 2014 and September 2016, the authors conducted 21 in-depth interviews with faculty who had experience teaching in implicit bias instruction or were interested in facilitating discussions related to implicit bias and the Implicit Association Test. Grounded theory methodology was used to analyze interview transcripts. RESULTS: Participants identified challenges that affect their ability to facilitate instruction in implicit bias. Faculty described the influence of their own background and identities as well as the influence of institutional values on their ability to facilitate implicit bias discussions. They noted the impact of resistant learners and faculty during discussions and made suggestions for institutional measures including the need for implementation of formalized longitudinal implicit bias curricula and faculty development. CONCLUSIONS: Faculty facilitating sessions on implicit bias must attend faculty development sessions to be equipped to deal with some of the challenges they may face. Buy-in from institutional leadership is essential for successful implementation of implicit bias teaching, and medical educators need to consider formalized longitudinal curricula addressing the recognition and management of implicit biases.