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Carlson, K.

Publications and source records attributed to Carlson, K..

2 recordsLinked to original sources

Maize Phyllosphere Microbial Community Niche Development Across Stages of Host Leaf Growth

The phyllosphere hosts a variety of microorganisms, including bacteria, which can play a positive role in the success of the host plant. Bacterial communities in the phylloplane are influenced by both biotic and abiotic factors, including host plant surface topography and chemistry, which change in concert with microbial communities as the plant leaves develop and age. We examined how Zea mays leaf microbial community structure changed with plant age. Ribosomal spacer length (ARISA) and scanning electron microscopic (size trait) imaging strategies were used to assess microbial community composition across maize plant ages, using a novel staggered experimental design. Significant changes in community composition were observed for both molecular and imaging analyses, and the two analysis methods provided complementary information about bacterial community structure within each leaf developmental stage. Both taxonomic and cell-size trait patterns provided evidence for niche-based contributions to microbial community development on leaves.

microbiology

Sparse coding and dimensionality reduction in cortex

Supported by recent computational studies, sparse coding and dimensionality reduction are emerging as a ubiquitous coding strategy across brain regions and modalities, allowing neurons to achieve nonnegative sparse coding (NSC) by efficiently encoding high-dimensional stimulus spaces using a sparse and parts-based population code. Reducing the dimensionality of complex, multimodal sensory streams is critically important for metabolically constrained brain areas to represent the world. In this article, we provide an overview of NSC, summarize evidence for its role in neural computation in disparate regions of the brain, ranging from visual processing to spatial navigation, and speculate that specific forms of synaptic plasticity and homeostatic modulation may underlie its implementation. We suggest that NSC may be an organizing principle in the nervous system.

neuroscience