994 resultados para KERMADEC ISLAND-ARC
Resumo:
Using data from field introduction experiments with Gammarus spp. conducted in the rivers of a small island, commencing in 1949, with resampling in the 60s, 70s, 80s, 90s and finally in 2005, we aimed to examine the long-term interaction of the native freshwater amphipod Gammarus duebeni celticus with the introduced G. pulex. Using physico-chemical data from a 2005 island-wide survey, we also aimed to find what environmental factors could influence the distribution of the two species.
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The discovery of a shallow water (
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A phantom was designed and implemented for the delivery of treatment plans to cells in vitro. Single beam, 3D-conformal radiotherapy (3D-CRT) plans, inverse planned five-field intensity-modulated radiation therapy (IMRT), nine-field IMRT, single-arc volumetric modulated arc therapy (VMAT) and dual-arc VMAT plans were created on a CT scan of the phantom to deliver 3 Gy to the cell layer and verified using a Farmer chamber, 2D ionization chamber array and gafchromic film. Each plan was delivered to a 2D ionization chamber array to assess the temporal characteristics of the plan including delivery time and 'cell's eye view' for the central ionization chamber. The effective fraction time, defined as the percentage of the fraction time where any dose is delivered to each point examined, was also assessed across 120 ionization chambers. Each plan was delivered to human prostate cancer DU-145 cells and normal primary AGO-1522b fibroblast cells. Uniform beams were delivered to each cell line with the delivery time varying from 0.5 to 20.54 min. Effective fraction time was found to increase with a decreasing number of beams or arcs. For a uniform beam delivery, AGO-1552b cells exhibited a statistically significant trend towards increased survival with increased delivery time. This trend was not repeated when the different modulated clinical delivery methods were used. Less sensitive DU-145 cells did not exhibit a significant trend towards increased survival with increased delivery time for either the uniform or clinical deliveries. These results confirm that dose rate effects are most prevalent in more radiosensitive cells. Cell survival data generated from uniform beam deliveries over a range of dose rates and delivery times may not always be accurate in predicting response to more complex delivery techniques, such as IMRT and VMAT.
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This article begins from the assumption (which may seem controversial to many) that anyone who thinks that our current economic crisis is a temporary blip until ‘normal service’ (i.e. a return to ‘business as usual’) is resumed, profoundly misunderstands the severity and significance of what’s happening to the global economy and its impacts on the future prosperity of the island of Ireland. The economic recession represents nothing short of a re-structuring of the global economy and the creation of a new dispensation between governments, markets and citizens. The full implications of the re-regulation of the market, with the state bailing out and part nationalising the financial sector in both jurisdictions on the island (as in other parts of the world) have yet to be seen, but what we are witnessing is the emergence of a new economic model. Those who think we can, or even ought to, return to the pre-2008 economic model, are gravely mistaken. The current economic downturn marks the end of the ‘neo-liberal’ model and the beginnings of the transition (an inevitable transition, this article will argue) towards a new low carbon, renewable, green and sustainable economy and society.