Brownlee Emily F.

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Brownlee
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Emily F.
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Author: Sosik, Heidi M. ×

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Now showing 1 - 11 of 11
  • Dataset
    2014 labeled IFCB images
    ( 2014) Sosik, Heidi M. ; Peacock, Emily E. ; Brownlee, Emily F.
  • Dataset
    2011 labeled IFCB images
    ( 2011) Sosik, Heidi M. ; Peacock, Emily E. ; Brownlee, Emily F.
  • Dataset
    2007 labeled IFCB images
    ( 2007) Sosik, Heidi M. ; Peacock, Emily E. ; Brownlee, Emily F.
  • Article
    Microzooplankton community structure investigated with imaging flow cytometry and automated live-cell staining
    (Inter-Research, 2016-05-25) Brownlee, Emily F. ; Olson, Robert J. ; Sosik, Heidi M.
    Protozoa play important roles in grazing and nutrient recycling, but quantifying these roles has been hindered by difficulties in collecting, culturing, and observing these often-delicate cells. During long-term deployments at the Martha’s Vineyard Coastal Observatory (Massachusetts, USA), Imaging FlowCytobot (IFCB) has been shown to be useful for studying live cells in situ without the need to culture or preserve. IFCB records images of cells with chlorophyll fluorescence above a trigger threshold, so to date taxonomically resolved analysis of protozoa has presumably been limited to mixotrophs and herbivores which have eaten recently. To overcome this limitation, we have coupled a broad-application ‘live cell’ fluorescent stain with a modified IFCB so that protozoa which do not contain chlorophyll (such as consumers of unpigmented bacteria and other heterotrophs) can also be recorded. Staining IFCB (IFCB-S) revealed higher abundances of grazers than the original IFCB, as well as some cell types not previously detected. Feeding habits of certain morphotypes could be inferred from their fluorescence properties: grazers with stain fluorescence but without chlorophyll cannot be mixotrophs, but could be either starving or feeding on heterotrophs. Comparisons between cell counts for IFCB-S and manual light microscopy of Lugol’s stained samples showed consistently similar or higher counts from IFCB-S. We show how automated classification through the extraction of image features and application of a machine-learning algorithm can be used to evaluate the large high-resolution data sets collected by IFCBs; the results reveal varying seasonal patterns in abundance among groups of protists.
  • Dataset
    2013 labeled IFCB images
    ( 2013) Sosik, Heidi M. ; Peacock, Emily E. ; Brownlee, Emily F.
  • Article
    Sixty years of Sverdrup : a retrospective of progress in the study of phytoplankton blooms
    (The Oceanography Society, 2014-03) Fischer, Alexis D. ; Moberg, Emily A. ; Alexander, Harriet ; Brownlee, Emily F. ; Hunter-Cevera, Kristen R. ; Pitz, Kathleen J. ; Rosengard, Sarah Z. ; Sosik, Heidi M.
    One of the most dramatic large-scale features in the ocean is the seasonal greening of the North Atlantic in spring and summer due to the accumulation of phytoplankton biomass in the surface layer. In 1953, Harald Ulrik Sverdrup hypothesized a now canonical mechanism for the development and timing of phytoplankton blooms in the North Atlantic. Over the next 60 years, Sverdrup's Critical Depth Hypothesis spurred progress in understanding of bloom dynamics and offered a valuable theoretical framework on which to build. In reviewing 60 years of literature, the authors trace the development of modern bloom initiation hypotheses, highlighting three case studies that illuminate the complexity, including both catalysts and impediments, of scientific progress in the wake of Sverdrup's hypothesis. Most notably, these cases demonstrate that the evolution of our understanding of phytoplankton blooms was paced by access not only to technology but also to concurrent insights from several disciplines. This exploration of the trajectories and successes in bloom studies highlights the need for expanding interdisciplinary collaborations to address the complexity of phytoplankton bloom dynamics.
  • Dataset
    2006 labeled IFCB images
    ( 2006) Sosik, Heidi M. ; Peacock, Emily E. ; Brownlee, Emily F.
  • Dataset
    2010 labeled IFCB images
    ( 2010) Sosik, Heidi M. ; Peacock, Emily E. ; Brownlee, Emily F.
  • Dataset
    2012 labeled IFCB images
    ( 2012) Sosik, Heidi M. ; Peacock, Emily E. ; Brownlee, Emily F.
  • Dataset
    2009 labeled IFCB images
    ( 2009) Sosik, Heidi M. ; Peacock, Emily E. ; Brownlee, Emily F.
  • Dataset
    2008 labeled IFCB images
    ( 2008) Sosik, Heidi M. ; Peacock, Emily E. ; Brownlee, Emily F.