108 research outputs found
Why âthe uplift of the Tibetan Plateauâ is a myth?
The often-used phrase âthe uplift of the Tibetan Plateauâ implies a flat-surfaced Tibet rose as a coherent entity, and that uplift was driven entirely by the collision and northward movement of India. Here, we argue that these are misconceptions derived in large part from simplistic geodynamic and climate modeling, as well as proxy misinterpretation. The growth of Tibet was a complex process involving mostly Mesozoic collisions of several Gondwanan terranes with Asia, thickening the crust and generating complex relief before the arrival of India. In this review, Earth system modeling, paleoaltimetry proxies and fossil finds contribute to a new synthetic view of the topographic evolution of Tibet. A notable feature overlooked in previous models of plateau formation was the persistence through much of the Cenozoic of a wide eastâwest orientated deep central valley, and the formation of a plateau occurred only in the late Neogene through compression and internal sedimentation
Conservation genomic analysis reveals ancient introgression and declining levels of genetic diversity in Madagascar's hibernating dwarf lemurs
The topographic evolution of the Tibetan Region as revealed by palaeontology
The Tibetan Plateau was built through a succession of Gondwanan terranes colliding with Asia during the Mesozoic. These accretions produced a complex Paleogene topography of several predominantly eastâwest trending mountain ranges separated by deep valleys. Despite this piecemeal assembly and resultant complex relief, Tibet has traditionally been thought of as a coherent entity rising as one unit. This has led to the widely used phrase âthe uplift of the Tibetan Plateauâ, which is a false concept borne of simplistic modelling and confounds understanding the complex interactions between topography climate and biodiversity. Here, using the rich palaeontological record of the Tibetan region, we review what is known about the past topography of the Tibetan region using a combination of quantitative isotope and fossil palaeoaltimetric proxies, and present a new synthesis of the orography of Tibet throughout the Paleogene. We show why âthe uplift of the Tibetan Plateauâ never occurred, and quantify a new pattern of topographic and landscape evolution that contributed to the development of todayâs extraordinary Asian biodiversity
Examining gender diversity growth as a model for inclusion of all underrepresented persons in medical physics
The significance of mentorship
In this chapter, we highlight the importance of mentorship in the pursuit of a career in academic medicine, describe the role of mentors, sponsors and coaches/advisors, provide evidence-based tools to help you identify a mentor and establish effective mentoring relationships, and discuss the key components that are essential in the maintenance of a mentor-mentee relationship. We end this chapter with a discussion of the Liaison Committee on Medical Education (LCME) and Accreditation Council for Graduate Medical Education (ACGME) mandates on mentorship as a requirement for all accredited medical training institutions. We present you with a description of potential challenges that mentor-mentee relationships may face. Lastly, we discuss the cycle of mentorship for the purpose of expanding growth and the constant support to students interested in academic medicine
Establishment of human iPSC-based models for the study and targeting of glioma initiating cells
International audienceGlioma tumour-initiating cells (GTICs) can originate upon the Ä transformation of neural progenitor cells (NPCs). Studies on GTICs have Ä focused on primary tumours from which GTICs could be isolated and the Ä use of human embryonic material. Recently, the somatic genomic landscape Ä of human gliomas has been reported. RTK (receptor tyrosine kinase) and Ä p53 signalling were found dysregulated in similar to 90% and 86% of Ä all primary tumours analysed, respectively. Here we report on the use of Ä human-induced pluripotent stem cells (hiPSCs) for modelling Ä gliomagenesis. Dysregulation of RTK and p53 signalling in hiPSC-derived Ä NPCs (iNPCs) recapitulates GTIC properties in vitro. In vivo Ä transplantation of transformed iNPCs leads to highly aggressive tumours Ä containing undifferentiated stem cells and their differentiated Ä derivatives. Metabolic modulation compromises GTIC viability. Last, Ä screening of 101 anti-cancer compounds identifies three molecules Ä specifically targeting transformed iNPCs and primary GTICs. Together, Ä our results highlight the potential of hiPSCs for studying human Ä tumourigenesis
A late Eocene palynological record of climate change and Tibetan Plateau uplift (Xining Basin, China)
Paleomagnetic tests of tectonic reconstructions of the India-Asia collision zone
International audienceSeveral solutions have been proposed to explain the long-standing kinematic observation that postcollisional upper crustal shortening within the Himalaya and Asia is much less than the magnitude of India-Asia convergence. Here we implement these hypotheses in global plate reconstructions and test paleolatitudes predicted by the global apparent polar wander path against independent, and the most robust paleomagnetic data. Our tests demonstrate that (1) reconstructed 600â750 km postcollisional intra-Asian shortening is a minimum value; (2) a 52 Ma collision age is only consistent with paleomagnetic data if intra-Asian shortening was ~900 km; a ~56â58 Ma collision age requires greater intra-Asian shortening; (3) collision ages of 34 or 65 Ma incorrectly predict Late Cretaceous and Paleogene paleolatitudes of the Tibetan Himalaya (TH); and (4) Cretaceous counterclockwise rotation of India cannot explain the paleolatitudinal divergence between the TH and India. All hypotheses, regardless of collision age, require major Cretaceous extension within Greater India
Participation in Active Learning Correlates to Higher Female Performance in a Pipeline Course for Underrepresented Students in Medicine
Genotype-phenotype correlation in primary hyperoxaluria type 1: The p.Gly170Arg AGXT mutation is associated with a better outcome
SCOPUS: ar.jinfo:eu-repo/semantics/publishe
- âŠ