title: Two-phase growth of high topography in eastern Tibet during the Cenozoic

authors: Wang, E.

subjects: fission-track thermochronology

abstract: High topography in eastern Tibet is thought to have formed when deep crust beneath the central Tibetan Plateau flowed towards the plateau margin, causing crustal thickening and surface uplift(1,2). Rapid exhumation starting about 10-15 million years ago is inferred to mark the onset of surface uplift and fluvial incision(3-6). Although geophysical data are consistent with weak crust capable of flow(7,8), it is unclear how the timing(9) and amount of deformation adjacent to the Sichuan Basin during the Cenozoic era can be explained in this way(10,11). Here we use thermochronology to measure the cooling histories of rocks exposed in a section that stretches vertically over 3 km adjacent to the Sichuan Basin. Our thermal models of exhumation-driven cooling show that these rocks, and hence the plateau margin, were subject to slow, steady exhumation during early Cenozoic time, followed by two pulses of rapid exhumation, one beginning 30-25 million years ago and a second 10-15 million years ago that continues to present. Our findings imply that significant topographic relief existed adjacent to the Sichuan Basin before the Indo-Asian collision. Furthermore, the onset of Cenozoic mountain building probably pre-dated development of the weak lower crust, implying that early topography was instead formed during thickening of the upper crust along faults. We suggest that episodes of mountain building may reflect distinct geodynamic mechanisms of crustal thickening

text: Two-phase growth of high topography in eastern Tibet during the Cenozoic High topography in eastern Tibet is thought to have formed when deep crust beneath the central Tibetan Plateau flowed towards the plateau margin, causing crustal thickening and surface uplift(1,2). Rapid exhumation starting about 10-15 million years ago is inferred to mark the onset of surface uplift and fluvial incision(3-6). Although geophysical data are consistent with weak crust capable of flow(7,8), it is unclear how the timing(9) and amount of deformation adjacent to the Sichuan Basin during the Cenozoic era can be explained in this way(10,11). Here we use thermochronology to measure the cooling histories of rocks exposed in a section that stretches vertically over 3 km adjacent to the Sichuan Basin. Our thermal models of exhumation-driven cooling show that these rocks, and hence the plateau margin, were subject to slow, steady exhumation during early Cenozoic time, followed by two pulses of rapid exhumation, one beginning 30-25 million years ago and a second 10-15 million years ago that continues to present. Our findings imply that significant topographic relief existed adjacent to the Sichuan Basin before the Indo-Asian collision. Furthermore, the onset of Cenozoic mountain building probably pre-dated development of the weak lower crust, implying that early topography was instead formed during thickening of the upper crust along faults. We suggest that episodes of mountain building may reflect distinct geodynamic mechanisms of crustal thickening

year: 2012

title: Associative learning deficiencies underlying aberrant feeding in the valproate rat model of autism

authors: Lawson, Katsiaryna

subjects: autism spectrum disorder

abstract: Autism spectrum disorder (ASD) is a heterogenous neurodevelopmental condition 
prevalent in over 1% of the global population. Aberrant feeding behaviours and 
feeding dysregulation are a prevalent and understudied difficulty. Individuals with 
ASD often present with poor health outcomes, including over/under eating, obesity, 
and restrictive feeding associated with poor dietary habits, however the underlying 
mechanisms are poorly understood. Here we propose an explanation for some 
neural mechanisms that may be responsible for feeding dysregulation present in 
ASD. We demonstrate that valproate rat models of ASD (VPA ASD) have a blunted 
neural response to LiCl-induced conditioned taste aversion and show 
transcriptional changes in the arcuate nucleus of the hypothalamus. Findings of this 
study also show that VPA ASD rats have significantly higher neural activation in the 
nucleus accumbens and the dorsal vagal complex in response to food, compared to 
controls. Our research suggests that some of the feeding abnormalities seen in 
people with ASD may stem from signalling deficiencies in brain areas involved in 
associative learning responses following ingestion of foods that cause malaise. 
Extremely restrictive feeding behaviours seen in ASD phenotypes may be caused by 
difficulties identifying foods that make them sick. These findings contribute to 
understanding neuromolecular drivers of anomalous feeding behaviours in people 
with ASD.

text: Associative learning deficiencies underlying aberrant feeding in the valproate rat model of autism Autism spectrum disorder (ASD) is a heterogenous neurodevelopmental condition 
prevalent in over 1% of the global population. Aberrant feeding behaviours and 
feeding dysregulation are a prevalent and understudied difficulty. Individuals with 
ASD often present with poor health outcomes, including over/under eating, obesity, 
and restrictive feeding associated with poor dietary habits, however the underlying 
mechanisms are poorly understood. Here we propose an explanation for some 
neural mechanisms that may be responsible for feeding dysregulation present in 
ASD. We demonstrate that valproate rat models of ASD (VPA ASD) have a blunted 
neural response to LiCl-induced conditioned taste aversion and show 
transcriptional changes in the arcuate nucleus of the hypothalamus. Findings of this 
study also show that VPA ASD rats have significantly higher neural activation in the 
nucleus accumbens and the dorsal vagal complex in response to food, compared to 
controls. Our research suggests that some of the feeding abnormalities seen in 
people with ASD may stem from signalling deficiencies in brain areas involved in 
associative learning responses following ingestion of foods that cause malaise. 
Extremely restrictive feeding behaviours seen in ASD phenotypes may be caused by 
difficulties identifying foods that make them sick. These findings contribute to 
understanding neuromolecular drivers of anomalous feeding behaviours in people 
with ASD.

year: 2025-04

title: Sylvia’s place: Ashton-Warner as New Zealand educational theorist.

authors: Middleton, Sue

subjects: educational theorist

abstract: Sylvia Ashton-Warner’s New Zealand educational context has been – and continues to be – misrepresented as antithetical to her creative methods. Sue Middleton, a professor of education, locates Sylvia’s educational ideas within the national and international Progressive Education movement, indicating that key education officials in post-war New Zealand encouraged creativity and self-expression.

This chapter makes the case that, as a teacher, an educational writer and theorist, Sylvia Ashton-Warner grew in, and not in spite of New Zealand. My argument unfolds in two parts. The first reviews theoretical ideas in the local and international educational environment in which Sylvia lived and worked. Sylvia and Keith Henderson taught in what was referred to until 1946 as the Native School system (and from 1948 until its abolition in 1968 as the Maori Scholl system). They trained and began work as teachers during the Great Depression; and Sylvia began serious writing during World War Two. The war and the Native Scholl system interested in complex ways with the wider international Progressive Education movement and its promotion ‘from the top’ in New Zealand’s public schools. An overview of Progressive (or New ) Education, the changing theories of culture and race in the Native School system, and relations between these during World War Two, opens a wide-angled aperture through which to read Sylvia’s early writing.

text: Sylvia’s place: Ashton-Warner as New Zealand educational theorist. Sylvia Ashton-Warner’s New Zealand educational context has been – and continues to be – misrepresented as antithetical to her creative methods. Sue Middleton, a professor of education, locates Sylvia’s educational ideas within the national and international Progressive Education movement, indicating that key education officials in post-war New Zealand encouraged creativity and self-expression.

This chapter makes the case that, as a teacher, an educational writer and theorist, Sylvia Ashton-Warner grew in, and not in spite of New Zealand. My argument unfolds in two parts. The first reviews theoretical ideas in the local and international educational environment in which Sylvia lived and worked. Sylvia and Keith Henderson taught in what was referred to until 1946 as the Native School system (and from 1948 until its abolition in 1968 as the Maori Scholl system). They trained and began work as teachers during the Great Depression; and Sylvia began serious writing during World War Two. The war and the Native Scholl system interested in complex ways with the wider international Progressive Education movement and its promotion ‘from the top’ in New Zealand’s public schools. An overview of Progressive (or New ) Education, the changing theories of culture and race in the Native School system, and relations between these during World War Two, opens a wide-angled aperture through which to read Sylvia’s early writing.

year: 2009