NSF Postdoctoral Fellowship in Biology for FY 2011

本行动资助2011年度美国国家科学基金会生物学博士后研究奖学金，扩大参与。该奖学金支持奖学金获得者在主办实验室的研究和培训计划，该奖学金获得者还提出了扩大生物学参与的计划。西尔维娅·纽维尔的研究和培训计划的题目是“海岸沉积物中固氮剂和反硝化剂的活性”。这个奖学金的主办机构是波士顿大学赞助科学家是罗宾逊·富尔韦勒博士。沿海系统极易受到氮污染的影响，导致大范围的氧气水平降低（缺氧），生物多样性减少，有害藻华增加。据记载，从废水中进入瓦奎特湾的氮负荷自1938年以来增加了一倍多。富营养化沿海生态系统中的缺氧也可以刺激令人费解的微生物反应，包括高速率的同时反硝化（氮去除）和固氮。当固定氮可用时，继续固定氮在能量上是不利的，并导致本研究的核心问题：为什么细菌在充满氮的条件下开启固氮？固氮是否会加剧富营养化和温室气体的产生？本研究调查了沉积物中反硝化和固氮细菌的分布和活动，以确定这些模式是否与高度局部，非常快速的氮转化的存在相一致。培训目标包括学习生物地球化学技术，包括岩心孵化和同位素方法。更广泛的影响包括参与瓦奎特湾国家河口研究保护区面向12-14岁儿童的“女性参与科学”项目，以及向当地少数民族高中提供服务。

This action funds an NSF Postdoctoral Research Fellowship in Biology for FY 2011, Broadening Participation. The fellowship supports a research and training plan in a host laboratory for the Fellow who also presents a plan to broaden participation in biology. The title of the research and training plan for this fellowship to Silvia Newell is "Activity of nitrogen fixers and denitrifiers in coastal sediments." The host institution for this fellowship is Boston University and the sponsoring scientist is Dr. Robinson Fulweiler.Coastal systems are acutely vulnerable to nitrogen pollution, resulting in wide-spread reduced oxygen levels (hypoxia), decreased biodiversity, and increased harmful algal blooms. Nitrogen loading from wastewater into Waquoit Bay is documented and has more than doubled since 1938. Hypoxia in eutrophic coastal ecosystems can also stimulate puzzling microbial responses, including high rates of simultaneous denitrification (nitrogen removal) and nitrogen fixation. Continuing to fix nitrogen when fixed nitrogen is available is energetically unfavorable and leads to the central questions of this research: Why do bacteria turn on nitrogen fixation under nitrogen-replete conditions? Can nitrogen fixation exacerbate eutrophication and greenhouse gas production? This research investigates the distributions and activities of denitrifying and nitrogen-fixing bacteria within the sediment to determine if the patterns are consistent with the existence of highly localized, very rapid nitrogen transformations. Training objectives include learning techniques of biogeochemistry including core incubation and isotope methods. Broader impacts include participation in the Women in Science program for 12-14 year olds at the Waquoit Bay National Estuarine Research Reserve, as well as outreach to local minority-serving high schools.