Evolution of the Australian-Antarctic discordance since Miocene time

In this study we chronicle the development of the Australian-Antarctic discordance (AAD), the crenelated portion of the Southeast Indian Ridge between ∼120° and 128°E, since anomaly 6y time (19 Ma). We reconstruct satellite-derived marine gravity fields and depth anomalies at selected times by first removing anomalies overlying seafloor younger than the selected age, and then rotating the remaining anomalies through improved finite rotations based on a very detailed set of magnetic anomaly identifications. Our gravity field reconstructions reveal that the overall length of the Australian-Antarctic plate boundary within the AAD has been increasing since 19 Ma. Concomitantly, the number of propagating rifts and fracture zones in the vicinity of the discordance has increased dramatically in recent times, effectively dividing it into its present-day configuration of five distinct spreading corridors (B1-B5) that are offset alternately to the north and south and exhibit varying degrees of asymmetric spreading. Our bathymetric reconstructions show that the regional, arcuate-shaped, negative depth anomaly (deeper than predicted by normal lithospheric cooling models) presently centered on the discordance began migrating westward before anomaly 5ad time (∼14.4 Ma), and that a localized depth anomaly low, which at time 5ad lay on the ridge axis in spreading corridor B5, has been split apart by subsequent seafloor spreading. The magnetic anomaly patterns suggest that the depth anomaly is not always associated with a particularly contorted plate boundary geometry. Although the plate boundary within the AAD has been getting progressively more crenelated with time, this effect shows little to no migration along the ridge axis since 19 Ma. Thus any geodynamic models of the evolution of the discordance must account for the following observations: (1) the crenelation of the plate boundary within the AAD has increased with time, (2) the center of the crenelated zone does not appear to have migrated along the ridge crest, and (3) both the depth anomaly and the isotopic boundary between Pacific and Indian mantle have been migrating westward along the ridge axis but at apparently different rates. We suggest that both along-axis migration of the depth anomaly and isotopic boundary, as well as temporal variation in the upwelling mantle material beneath the AAD, and local tectonic effects are required in order to explain these observations

Starting fresh: a mixed method study of follower job satisfaction, trust, and views of their leader’s behavior

IntroductionThe leadership literature has been dominated by the study of broad styles rather than the identification of specific key behaviors. To address this deficiency, a mixed method approach was utilized to explore how follower behavioral descriptions of their leaders would relate to potential outcomes of trust in that leader and job satisfaction.MethodsData were collected from 273 hospital direct reports of 44 managers. They were asked to first describe the leadership approach of their managers in their own words, and then complete quantitative measures of the two potential outcomes.ResultsThe qualitative responses were coded into nine leadership behavior themes listed here in order from most to least often mentioned: Kindness, Supportive, Open to Input, Allow Autonomy, Engage with Team, Transparency, Fairness, Professionalism, Hold Accountable. All behavior themes related significantly to trust of the leader, with three themes relating significantly to job satisfaction (Transparency, Fairness, and Professionalism).DiscussionThese results provide a more specific view of leader behavior than does the typical style approach

Do incoming residents vary in measures of emotional status even prior to residency training?

Objectives: To determine whether Empathy, Emotional Intelligence, and Burnout scores differ by specialty in incoming residents. Methods: This is a single-site, prospective, cross-sectional study. Three validated survey instruments, the Jefferson Scale of Physician Empathy, Maslach Burnout Inventory, and Emotional and Social Competency Inventory, were written into a survey platform as a single 125-question Qualtrics survey. Over three academic years, 2015-2017, 229 incoming residents across all specialties were emailed the survey link during orientation. Residents were grouped by incoming specialty with anonymity assured. A total of 229 responses were included, with 121 (52.8%) identifying as female. Statistical analysis was performed using the Analysis of Variance or Kruskal-Wallis test, Chi-Square or Fisher\u27s Exact test, and Independent Samples t-test or Mann Whitney U test. A Bonferroni correction was applied for pairwise comparisons. Results: Family Medicine had a higher median Jefferson Scale of Physician Empathy score (127) compared to Emergency Medicine (115), (U=767.7, p=0.0330). Maslach Burnout Inventory depersonalization and personal accomplishment subcategory scores showed a significant difference between specialties when omnibus tests were performed, but pairwise comparisons with emergency medicine residents showed no differences. Differences were found in the Maslach Burnout Inventory categories of Depersonalization (χ Conclusions: Differences in measures of well-being exist across specialties, even prior to the start of residency training. The implication for educators of residency training is that some incoming residents, regardless of specialty, already exhibit troublesome features of burnout, and resources to effectively deal with these residents should be developed and utilized