Purchasing an autoclave and a cryogenic freezer to foster research on the effects of environmental change on plankton

由于数十年的酸沉积，以及多次伐木和森林再生长的循环，加拿大东部土壤和湖泊中的钙（Ca）浓度目前正在下降。因此，富钙生物群的数量，如浮游水蚤，水蚤，正在减少。由于水蚤是远洋生物多样性的重要贡献者，也是鱼类食物和能量的管道，它们的损失引起了水生生态学家和知情的湖泊管理者的关注。水蚤对钙下降的反应因其营养状况而异，也可能与暴露于其他压力源（如金属）有关。因此，为了量化有害的钙阈值，我们必须在实验中注意其他应激源，如营养物质和金属。为了确定作用机制，我们还需要控制实验室生物测定，然后在生化和分子（即基因表达）水平上进行研究。约克大学的多重生态压力评估实验室（火焰实验室）设备齐全，可以对水蚤进行所需的多重压力源生物测定，但没有必要的设备来控制生物测定介质中的细菌水平，也没有必要的设备来保持样品在稳定的条件下进行后续的分子测定。我需要一个高压灭菌器和一个低温冷冻机来满足这些需求。该设备将大大改善分析介质中细菌水平的控制，并将促进在日益复杂的世界（即水温变暖、磷和金属含量降低）中对水蚤低钙胁迫的机制的研究。该设备将培养4名年轻科学家在新认识到的、广泛存在的环境钙下降威胁方面的跨学科培训。加拿大拥有得天独厚的淡水湖，但它们的保护和管理需要新的工具来处理新认识到的复杂性。本应用程序中的设备将促进毒物基因组学的实际发展，这是一个准备生产一整套全新评估工具的领域，需要从多种可能的环境破坏原因中进行选择的工具，那些需要管理干预的干扰的实际原因。

Because of decades of acid deposition, and multiple cycles of logging and forest re-growth, calcium (Ca) concentrations are currently falling in soils and lakes in Eastern Canada. In consequence, populations of Ca-rich biota, such as the planktonic water flea, Daphnia, are declining. Because Daphnia are important contributors to pelagic biodiversity, and conduits of food and energy to fish, their losses are of concern to aquatic ecologists and informed lake managers. The response of Daphniids to Ca decline varies with their nutritional status, and likely with exposure to other stressors, such as metals. Thus to quantify the damaging Ca thresholds, we must pay attention in our experiments to other stressors such as nutrients and metals. To identify the mechanisms of effect, we also need controlled laboratory bioassays, followed by research at both the biochemical and molecular (i.e. gene expression) levels. York University's Field Laboratory for the Assessment of Multiple Ecological Stressors (FLAMES lab) is well equipped to conduct the needed multiple-stressor bioassays on daphniids, but does not have the needed equipment to control bacterial levels in bioassay media, nor to maintain samples in a stable condition for subsequent molecular assays. I request an autoclave and a cryogenic freezer to fill these needs. This equipment will permit much improved control of bacterial levels in assay media, and will foster research on the mechanisms underlying low Ca stress on daphniids in an increasing complex world, i.e. with warming waters, lower phosphorus and metals. This equipment will foster the interdisciplinary training of 4 young scientists in the newly recognized, widespread threat of environmental calcium decline. Canada is uniquely blessed with freshwater lakes, but their protection and management requires new tools to deal with newly recognized complexities. The equipment in this application will foster the practical development of toxicogenomics, a field poised to produce a whole new box of assessment tools, tools needed to select from among multiple plausible causes of environmental damage, those actual causes of disturbance that warrant management intervention.