Tectono-stratigraphic evolution and crustal architecture of the Orphan Basin during North Atlantic rifting

The Orphan Basin is located in the deep offshore of the Newfoundland margin, and it is bounded by the continental shelf to the west, the Grand Banks to the south, and the continental blocks of Orphan Knoll and Flemish Cap to the east. The Orphan Basin formed in Mesozoic time during the opening of the North Atlantic Ocean between eastern Canada and western Iberia–Europe. This work, based on well data and regional seismic reflection profiles across the basin, indicates that the continental crust was affected by several extensional episodes between the Jurassic and the Early Cretaceous, separated by events of uplift and erosion. The preserved tectono-stratigraphic sequences in the basin reveal that deformation initiated in the eastern part of the Orphan Basin in the Jurassic and spread towards the west in the Early Cretaceous, resulting in numerous rift structures filled with a Jurassic–Lower Cretaceous syn-rift succession and overlain by thick Upper Cretaceous to Cenozoic post-rift sediments. The seismic data show an extremely thinned crust (4–16 km thick) underneath the eastern and western parts of the Orphan Basin, forming two sub-basins separated by a wide structural high with a relatively thick crust (17 km thick). Quantifying the crustal architecture in the basin highlights the large discrepancy between brittle extension localized in the upper crust and the overall crustal thinning. This suggests that continental deformation in the Orphan Basin involved, in addition to the documented Jurassic and Early Cretaceous rifting, an earlier brittle rift phase which is unidentifiable in seismic data and a depth-dependent thinning of the crust driven by localized lower crust ductile flow

Neural Computation via Neural Geometry: A Place Code for Inter-whisker Timing in the Barrel Cortex?

The place theory proposed by Jeffress (1948) is still the dominant model of how the brain represents the movement of sensory stimuli between sensory receptors. According to the place theory, delays in signalling between neurons, dependent on the distances between them, compensate for time differences in the stimulation of sensory receptors. Hence the location of neurons, activated by the coincident arrival of multiple signals, reports the stimulus movement velocity. Despite its generality, most evidence for the place theory has been provided by studies of the auditory system of auditory specialists like the barn owl, but in the study of mammalian auditory systems the evidence is inconclusive. We ask to what extent the somatosensory systems of tactile specialists like rats and mice use distance dependent delays between neurons to compute the motion of tactile stimuli between the facial whiskers (or ‘vibrissae’). We present a model in which synaptic inputs evoked by whisker deflections arrive at neurons in layer 2/3 (L2/3) somatosensory ‘barrel’ cortex at different times. The timing of synaptic inputs to each neuron depends on its location relative to sources of input in layer 4 (L4) that represent stimulation of each whisker. Constrained by the geometry and timing of projections from L4 to L2/3, the model can account for a range of experimentally measured responses to two-whisker stimuli. Consistent with that data, responses of model neurons located between the barrels to paired stimulation of two whiskers are greater than the sum of the responses to either whisker input alone. The model predicts that for neurons located closer to either barrel these supralinear responses are tuned for longer inter-whisker stimulation intervals, yielding a topographic map for the inter-whisker deflection interval across the surface of L2/3. This map constitutes a neural place code for the relative timing of sensory stimuli

Holocene pollen records from Caution Bay, southern mainland Papua New Guinea

This study presents new palynological data from Caution Bay, south-central Papua New Guinea (PNG). It explores Holocene mangrove transitional events along a tide-dominated shoreline, and expands reconstructive detail for the wider southern PNG lowlands. Coinciding with recent regional archaeological research, this study also holds implications for interpretations of the Holocene settlement of Caution Bay and long-term people-landscape interactions. Data demonstrate a late-Holocene mangrove to mudflat transition, with vegetation patterns largely a function of low sediment loading, sedimentary redistributions and salinisation upon sea level decline c. 2000 cal. Yr BP. These trends appear unique to Caution Bay, highlighting a variety of Holocene shoreline vegetation changes along the PNG south coast, each dependent on geomorphologic setting and hydrological fluxes. Further work is required to elucidate vegetation change inland of the coastal zone. Greater understanding of burning patterns and an archaeological collaboration are required to determine more concisely dryland plant spatial and temporal variability

Analysis of Postdoctoral Training Outcomes That Broaden Participation in Science Careers

Postdoctoral training is an optimal time to expand research skills, develop independence, and shape career trajectories, making this training period important to study in the context of career development. Seeding Postdoctoral Innovators in Research and Education (SPIRE) is a training program that balances research, teaching, and professional development. This study examines the factors that promote the transition of postdocs into academic careers and increase diversity in science, technology, engineering, and mathematics. Data indicate that SPIRE scholars (n = 77) transition into faculty positions at three times the national average with a greater proportion of underrepresented racial minorities (URMs) and females represented among SPIRE scholars. Logistic regression models indicate that significant predictors are the intended career track at the start of the postdoctoral training and the number of publications. Factors necessary for successful transition are teaching experience as independent instructors, professional development opportunities, and the experience of balancing teaching with research. Scholars’ continued commitment to increasing diversity in their faculty roles was demonstrated by their attainment of tenure-track positions at minority-serving institutions, continued mentorship of URMs, and engagement with diversity initiatives. These results suggest that a postdoctoral program structured to include research, teaching, and diversity inclusion facilitates attainment of desired academic positions with sustained impacts on broadening participation