107 research outputs found
Tajik Basin: A composite record of sedimentary basin evolution in response to tectonics in the Pamir
Investigation of a >6âkmâthick succession of Cretaceous to Cenozoic sedimentary rocks in the Tajik Basin reveals that this depocentre consists of three stacked basin systems that are interpreted to reflect different mechanisms of subsidence associated with tectonics in the Pamir Mountains: a Lower to midâCretaceous succession, an Upper CretaceousâLower Eocene succession and an EoceneâNeogene succession. The Lower to midâCretaceous succession consists of fluvial deposits that were primarily derived from the Triassic KarakulâMazar subductionâaccretion complex in the northern Pamir. This succession is characterized by a convexâup (accelerating) subsidence curve, thickens towards the Pamir and is interpreted as a retroarc foreland basin system associated with northward subduction of Tethyan oceanic lithosphere. The Upper Cretaceous to early Eocene succession consists of fineâgrained, marginal marine and sabkha deposits. The succession is characterized by a concaveâup subsidence curve. Regionally extensive limestone beds in the succession are consistent with late stage thermal relaxation and relative seaâlevel rise following lithospheric extension, potentially in response to Tethyan slab rollback/foundering. The Upper Cretaceousâearly Eocene succession is capped by a middle Eocene to early Oligocene (ca. 50â30 Ma) disconformity, which is interpreted to record the passage of a flexural forebulge. The disconformity is represented by a depositional hiatus, which is 10â30 Myr younger than estimates for the initiation of IndiaâAsia collision and overlaps in age with the start of prograde metamorphism recorded in the Pamir gneiss domes. Overlying the disconformity, a >4âkmâthick upper EoceneâNeogene succession displays a classic, coarsening upward unroofing sequence characterized by accelerating subsidence, which is interpreted as a retroâforeland basin associated with crustal thickening of the Pamir during IndiaâAsia collision. Thus, the Tajik Basin provides an example of a longâlived composite basin in a retrowedge position that displays a sensitivity to plate margin processes. Subsidence, sediment accumulation and basinâforming mechanisms are influenced by subduction dynamics, including periods of slabâshallowing and retreat
26th Annual Computational Neuroscience Meeting (CNS*2017): Part 3 - Meeting Abstracts - Antwerp, Belgium. 15â20 July 2017
This work was produced as part of the activities of FAPESP Research,\ud
Disseminations and Innovation Center for Neuromathematics (grant\ud
2013/07699-0, S. Paulo Research Foundation). NLK is supported by a\ud
FAPESP postdoctoral fellowship (grant 2016/03855-5). ACR is partially\ud
supported by a CNPq fellowship (grant 306251/2014-0)
Modelling the Stroop effect: A connectionist approach
A connectionist model, which simulates the operation of prefrontal circuits during Stroop task is proposed. The Stroop test has traditionally been used as a measure of cognitive inhibition. The task is to inhibit an over-learned, habitual response (i.e., reading color words) in favor of an unusual, novel requirement (i.e., naming incongruously printed colors of color words). The longer durations in completing the task indicate an inability to inhibit habitual but contextually inappropriate response tendencies, which is suggestive of a prefrontal dysfunction. The connectionist model is designed adapting artificial neural networks (ANNs) in such a way that each ANN corresponds to a particular neuroanatomic component of the prefrontal circuit which is likely to take part in the execution of the Stroop task. The ability of the proposed model to simulate the normal and the abnormal performance on the Stroop task is tested. The simulation results show that the model is consistent with the clinical data. (c) 2006 Elsevier B.V. All rights reserved
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