NSFGEO-NERC: Collaborative Research: Novel imaging, physiology and numerical approaches for understanding biologically mediated, unsteady sinking in marine diatoms

NSFGEO-NERC：合作研究：用于了解海洋硅藻生物介导的不稳定下沉的新颖成像、生理学和数值方法

• 批准号: 2023434
• 负责人: Lee Karp-Boss
• 金额: $ 18.14万
• 依托单位: University of Maine
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2021
• 资助国家: 美国
• 起止时间: 2021-04-01 至 2025-03-31
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2023434&HistoricalAwards=false
• 关键词: NSFGEO; NERC; Collaborative; Research; Novel

This is a project that is jointly funded by the National Science Foundation's Directorate of Geosciences (NSF/GEO) and the National Environment Research Council (UKRI/NERC) of the United Kingdom (UK) via the NSF/GEO-NERC Lead Agency Agreement. This Agreement allows a single joint US/UK proposal to be submitted and peer-reviewed by the Agency whose investigator has the largest proportion of the budget. Upon successful joint determination of an award, each Agency funds the proportion of the budget and the investigators associated with its own investigators and component of the work.This project takes a small-scale approach to look at individual cells to investigate the sinking of marine diatoms, which on larger scales has implications for how food for larger organisms, carbon, and organic particles move throughout the ocean. Diatoms are a type of phytoplankton, cells that use photosynthesis in surface waters to produce roughly half of the world’s oxygen and the food to support ocean food webs. They have a heavy, glass-like outer wall which causes them to sink and move up to 40% of particulate organic carbon from the ocean’s surface to the deep sea. The investigators are using novel methods to determine how diatoms regulate their sinking quickly in response to different environmental conditions. These include state-of-the-art video measurements of individual cells, a micoelectrode approach to understand changes at cell surfaces, and microscopy to see changes inside and at the surface of cells. The resulting information will be used to build a model to understand how and why diatoms use unsteady sinking behavior based on their environment. The project supports early career investigators, provides training for a postdoctoral scientist and undergraduate students, and develops a collaboration between US and UK scientists. The team is also developing lesson plans in conjunction with local high schools with high populations of underrepresented students in STEM fields. The problem of sinking and suspension of diatoms has received considerable attention because of its ecological, evolutionary and biogeochemical significance, yet understanding of the processes that regulate sinking rates remains rudimentary. The investigators have used new techniques to make preliminary observations showing that some species of diatom exhibit an unsteady sinking behavior that consists of rapid changes of buoyancy on time scales of seconds. However, it remains unclear how widely this behavior matters across species and ocean conditions. In this study, the team of investigators is using state-of-the-art video-based measurements of sinking rates of individual cells to assess the prevalence of unsteady sinking among centric and pennate diatoms of varying cell sizes and quantify how this behavior changes in response to sharp gradients in nutrients and light. The project leverages an interdisciplinary, international collaboration to combine innovative optical techniques, advanced tools to assess cell physiology, and numerical modeling approaches to characterize suspension properties for individual diatom cells. Results are likely to transform the way we think about the ecology of diatoms, their strategies for nutrient acquisition, and mechanisms to control their buoyancy, in particular the modulation of volume and membrane of the central vacuole. This project contributes to the development of novel tools for single cell physiological studies, most notably direct measurement of diffusive boundary layers around cells under varying flow conditions and numerical modeling of cell-level processes.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

这是一个联合的项目，国家科学基金会（NSF/GEO）和英国（UK）（英国）（英国）的国家环保拱门委员会（NSF/GEO-GEO-NERCC LEACCC LEAC CANCE协议允许）一项联合美国/英国提交的提议将在成功的联合确定裁决后提交预算，每个机构为预算提供了资金，与其自己的调查人员相关的调查人员采取了小规模的方法不知所措，在较大的尺寸上，这对食物食品的含义较大，整个海洋中有一些更大的生物。从海洋表面到深海的有机碳正在使用方法来调节其下沉的方法，以响应不同的环境条件。细胞表面和显微镜将在细胞的RFACE内部看到。和科学家。速度仍然是基本的，研究人员使用了新技术，使一些硅藻在该研究中的行为中广泛地表现出某些硅藻的浮力表现出浮力的行为。研究人员是对单个细胞的下沉速率的最新测量，以评估不稳定的下沉，central和倾斜的细胞大小的MS，并量化了这种行为如何响应营养和光中的尖锐梯度，结合创新的光学技术，评估细胞的高级工具和数值的国际协作，以表征单个硅藻细胞的悬浮物。 vacura。用于单元生理学研究的含量，使用基金会的智力优点和更广泛的影响标准。

项目成果

Measurements of trajectories and spatial distributions of diatoms (Coscinodiscus spp.) at dissipation scales of turbulence

湍流耗散尺度下硅藻（Coscinodiscus spp.）的轨迹和空间分布测量

• DOI: 10.1007/s00348-021-03240-5
• 发表时间: 2021
• 期刊: Experiments in Fluids
• 影响因子: 2.4
• 作者: Pujara, Nimish;Du Clos, Kevin T.;Ayres, Stephanie;Variano, Evan A.;Karp-Boss, Lee
• 通讯作者: Karp-Boss, Lee