University of Sydney

About: University of Sydney is a education organization based out in Sydney, New South Wales, Australia. It is known for research contribution in the topics: Population & Health care. The organization has 61532 authors who have published 187345 publications receiving 6114218 citations. The organization is also known as: Sydney University & USyd.

Melanoma whole-exome sequencing identifies (V600E)B-RAF amplification-mediated acquired B-RAF inhibitor resistance.

Abstract: The development of acquired drug resistance hampers the long-term success of B-RAF inhibitor therapy for melanoma patients. Here we show (V600E)B-RAF copy-number gain as a mechanism of acquired B-RAF inhibitor resistance in 4 out of 20 (20%) patients treated with B-RAF inhibitor. In cell lines, (V600E)B-RAF overexpression and knockdown conferred B-RAF inhibitor resistance and sensitivity, respectively. In (V600E)B-RAF amplification-driven (versus mutant N-RAS-driven) B-RAF inhibitor resistance, extracellular signal-regulated kinase reactivation is saturable, with higher doses of vemurafenib down-regulating phosho-extracellular signal-regulated kinase and re-sensitizing melanoma cells to B-RAF inhibitor. These two mechanisms of extracellular signal-regulated kinase reactivation are sensitive to the MEK1/2 inhibitor AZD6244/selumetinib or its combination with the B-RAF inhibitor vemurafenib. In contrast to mutant N-RAS-mediated (V600E)B-RAF bypass, which is sensitive to C-RAF knockdown, (V600E)B-RAF amplification-mediated resistance functions largely independently of C-RAF. Thus, alternative clinical strategies may potentially overcome distinct modes of extracellular signal-regulated kinase reactivation underlying acquired B-RAF inhibitor resistance in melanoma.

Beyond the ‘digital natives’ debate: Towards a more nuanced understanding of students' technology experiences

Abstract: The idea of the ‘digital natives’, a generation of tech-savvy young people immersed in digital technologies for which current education systems cannot cater, has gained widespread popularity on the basis of claims rather than evidence. Recent research has shown flaws in the argument that there is an identifiable generation or even a single type of highly adept technology user. For educators, the diversity revealed by these studies provides valuable insights into students’ experiences of technology inside and outside formal education. While this body of work provides a preliminary understanding, it also highlights subtleties and complexities that require further investigation. It suggests, for example, that we must go beyond simple dichotomies evident in the digital natives debate to develop a more sophisticated understanding of our students’ experiences of technology. Using a review of recent research findings as a starting point, this paper identifies some key issues for educational researchers, offers new ways of conceptualizing key ideas using theoretical constructs from Castells, Bourdieu and Bernstein, and makes a case for how we need to develop the debate in order to advance our understanding.

Fluorescent pigments in corals are photoprotective

Abstract: All reef-forming corals depend on the photosynthesis performed by their algal symbiont, and such corals are therefore restricted to the photic zone. The intensity of light in this zone declines over several orders of magnitude--from high and damaging levels at the surface to extreme shade conditions at the lower limit. The ability of corals to tolerate this range implies effective mechanisms for light acclimation and adaptation. Here we show that the fluorescent pigments (FPs) of corals provide a photobiological system for regulating the light environment of coral host tissue. Previous studies have suggested that under low light, FPs may enhance light availability. We now report that in excessive sunlight FPs are photoprotective; they achieve this by dissipating excess energy at wavelengths of low photosynthetic activity, as well as by reflecting of visible and infrared light by FP-containing chromatophores. We also show that FPs enhance the resistance to mass bleaching of corals during periods of heat stress, which has implications for the effect of environmental stress on the diversity of reef-building corals, such as enhanced survival of a broad range of corals allowing maintenance of habitat diversity.