In the helium-rich intershell region of asymptotic giant branch (AGB) stars, slow neutron-capture nucleosynthesis produces heavy elements beyond iron. If the stars experience a final-flash of the He-burning shell, a pulse-driven convection zone establishes, the stars become hydrogen-deficient and exhibit former intershell material at their surfaces. In their subsequent evolution towards the white-dwarf cooling sequence, but still at constant luminosity, a strong stellar wind prevents diffusion to wipe out the information about AGB yields. We present and interpret the analysis results of hydrogen-rich and -deficient post-AGB stars, discuss difficulties in their analysis and review the implications on the understanding of post-AGB evolution.

OBJECTIVES/SPECIFIC AIMS: Rodent models can be used to study neonatal abstinence syndrome (NAS), but the applicability of findings from the models to NAS in humans is not well understood. The objective of this study was to develop a rat model of norbuprenorphine-induced NAS and validate its translational value by comparing blood concentrations in the norbuprenorphine-treated pregnant rat to those previously reported in pregnant women undergoing buprenorphine treatment. METHODS/STUDY POPULATION: Pregnant Long-Evans rats were implanted with 14-day osmotic minipumps containing vehicle, morphine (positive control), or norbuprenorphine (0.3–3 mg/kg/d) on gestation day 9. Within 12 hours of delivery, pups were tested for spontaneous or precipitated opioid withdrawal by injecting them with saline (10 mL/kg, i.p.) or naltrexone (1 or 10 mg/kg, i.p), respectively, and observing them for well-validated neonatal withdrawal signs. Blood was sampled via indwelling jugular catheters from a subset of norbuprenorphine-treated dams on gestation day 8, 10, 13, 17, and 20. Norbuprenorphine concentrations in whole blood samples were quantified using LC/MS/MS. RESULTS/ANTICIPATED RESULTS: Blood concentrations of norbuprenorphine in rats exposed to 1–3 mg/kg/d of norbuprenorphine were similar to levels previously reported in pregnant women undergoing buprenorphine treatment. Pups born to dams treated with these doses exhibited robust withdrawal signs. Blood concentrations of norbuprenorphine decreased across gestation, which is similar to previous reports in humans. DISCUSSION/SIGNIFICANCE OF IMPACT: These results suggest that dosing dams with 1–3 mg/kg/day norbuprenorphine produces maternal blood concentrations and withdrawal severity similar to those previously reported in humans. This provides evidence that, at these doses, this model is useful for testing hypotheses about norbuprenorphine that are applicable to NAS in humans.

As commitment devices, international institutions encourage cooperation by imposing costs on members who do not live up to their commitments. However, the costs that institutions can impose are limited, so that their commitment capacity is weak. Institutions can also impose costs as a condition of membership, allowing them to serve as costly signals. A model of weak commitment and costly signaling leads to a number of hypotheses about patterns of cooperation, institutional membership, and states’ preferences over institutional design. For example, existing members of an institution should impose higher ex ante costs when a potential new member could either gain significant benefits from reneging on their commitments in the future, and when the new member expects to gain high benefits from future cooperation. These results are consistent with empirical work on institutions including peacekeeping and the World Trade Organization.

Objectives: To examine whether apolipoprotein e4 (APOE) status moderates the association of family environment with child functioning following early traumatic brain injury (TBI). Methods: Sixty-five children with moderate to severe TBI and 70 children with orthopedic injury (OI) completed assessments 6, 12, 18 months, and 3.5 and 6.8 years post injury. DNA was extracted from saliva samples and genotyped for APOE e4 status. Linear mixed models examined moderating effects of APOE e4 status on associations between two family environment factors (parenting style, home environment) and three child outcomes (executive functioning, behavioral adjustment, adaptive functioning). Results: Children with TBI who were carriers of the e4 allele showed poorer adaptive functioning relative to non-carriers with TBI and children with OI in the context of low authoritarianism. At high levels of authoritarianism, non-carriers with TBI showed the poorest adaptive functioning among groups. There were no main effects or interactions involving APOE and executive functioning or behavioral adjustment. Conclusions:The APOE e4 allele was detrimental for long-term adaptive functioning in the context of positive parenting, whereas in less optimal parenting contexts, being a non-carrier was detrimental. We provide preliminary evidence for an interaction of APOE e4 status and parenting style in predicting long-term outcomes following early TBI. (JINS, 2016, 22, 859–864)

Evaluations of teaching effectiveness rely heavily on student evaluations of teaching. However, an accumulating body of evidence shows that these evaluations are subject to gender bias. Theories of leadership and role incongruity suggest that this bias should be especially prominent in large courses. This article examines publicly available data from two large political science departments and finds that female instructors receive substantively and significantly lower ratings than male instructors in large courses. The author discusses the implications of apparent gender bias in teaching evaluations for the professional success of female faculty. Findings of gender bias in evaluations in other fields also hold in political science and are particularly problematic in the evaluation of large courses.