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重新生长，加拿大东部土壤和湖泊中的钙(Ca)浓度目前正在下降。因此，富钙生物群的数量正在下降，例如浮游水蚤。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见多识广的湖泊管理者的关注。达夫尼虫对钙含量下降的反应因其营养状况不同而不同，可能与暴露于其他应激源，如金属有关。因此，为了量化破坏性的钙阈值，我们在实验中必须注意其他应激源，如营养物质和金属。为了确定作用机制，我们还需要受控的实验室生物测定，然后在生物化学和分子(即基因表达)水平上进行研究。约克大学的多生态应激源评估野外实验室(FLAMES LAB)设备齐全，可以对甲虫进行所需的多应激源生物分析，但没有必要的设备来控制生物分析介质中的细菌水平，也没有为后续分子分析将样品保持在稳定条件下所需的设备。我要求一台高压灭菌器和一台低温冷冻机来满足这些需求。该设备将大大改善对检测介质中细菌水平的控制，并将促进在一个日益复杂的世界中，即随着水域变暖，磷和金属的减少，低钙胁迫对丝虫的潜在机制的研究。该设备将促进4名年轻科学家在新认识的、普遍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应对新认识的复杂性。这一应用中的设备将促进毒性基因组学的实际发展，这一领域将产生一套全新的评估工具，从多种看似合理的环境破坏原因中进行选择所需的工具，那些需要管理干预的实际干扰原因。

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.