Dynamic Thermal Physiology of Host-Parasite Interactions

气候变化和大流行病是21世纪最严峻的两项挑战。在这个有可能增加温度和气候变化的新时代，控制传染病的传播将需要深入了解气候变化如何影响寄生虫病。大多数关于气候-疾病相互作用的研究都集中在平均气温和降水量上，而忽略了短期气候波动。这种方法假设，无论是寄生虫，也不是他们的主机适应温度的变化，尽管有证据表明，这样的适应反应是普遍存在于变温主机。考虑到这些适应反应可能会极大地改变气候疾病模型的预测，特别是对于具有变温宿主和媒介的疾病（例如，疟疾）。然而，目前还没有定量的理论来描述寄生虫和宿主对温度变化的适应反应。约翰逊和他的同事们将通过以下方式填补这一重要的知识空白：（1）开发一个数学模型，描述温度变化如何影响寄生虫感染;（2）使用一系列受控温度实验在吸虫-蝌蚪系统中对该模型进行参数化;（3）在人工池塘中测试该模型在不同温度变化时间尺度上的定量预测。他们的核心假设是，寄生虫比宿主更快地适应温度变化，因为它们的体积更小，代谢更快，导致在变温条件下感染率更高。该项目还将培训本科生，研究生和博士后研究学者，并通过公共宣传和K-12教师研讨会提高科学意识。

Climate change and pandemic disease are two of the most daunting challenges of the twenty-first century. In this new era with the potential for increased temperatures and climate variability, controlling the spread of infectious diseases will require a deep understanding of how climate variation influences parasitic diseases. Most studies of climate-disease interactions have focused on mean temperature and precipitation, ignoring short-term climate fluctuations. This approach assumes that neither parasites nor their hosts acclimate to temperature shifts, despite evidence that such acclimation responses are pervasive in ectothermic hosts. Accounting for these acclimation responses could dramatically alter predictions of climate-disease models, particularly for diseases with ectothermic hosts and vectors (e.g., malaria). However, there is currently no quantitative theory describing parasite and host acclimation responses to temperature shifts. Johnson and his colleagues will fill this important gap in knowledge by (1) developing a mathematical model describing how temperature variability influences parasitic infection, (2) parameterizing this model in a trematode-tadpole system using a series of controlled temperature experiments, and (3) testing quantitative predictions of the model across different timescales of temperature variability in artificial ponds. Their central hypothesis is that parasites acclimate to temperature changes more rapidly than their hosts because of their smaller sizes and faster metabolisms, leading to higher infection rates under variable-temperature conditions. This project will also train undergraduate, graduate, and post-doctoral research scholars and promote science awareness through public outreach and workshops for K-12 teachers.