Biophysical properties at patch scale shape the metabolism of biofilm landscapes.

Phototrophic biofilms form complex spatial patterns in streams and rivers, yet, how community patchiness, structure and function are coupled and contribute to larger-scale metabolism remains unkown. Here, we combined optical coherence tomography with automated O microprofiling and amplicon sequencing in a flume experiment to show how distinct community patches interact with the hydraulic environment and how this affects the internal distribution of oxygen. We used numerical simulations to derive rates of community photosynthetic activity and respiration at the patch scale and use the obtained parameter to upscale from individual patches to the larger biofilm landscape.

Morphogenesis and oxygen dynamics in phototrophic biofilms growing across a gradient of hydraulic conditions.

Biofilms are surface-attached and matrix-enclosed microbial communities that dominate microbial life in numerous ecosystems. Using flumes and automated optical coherence tomography, we studied the morphogenesis of phototrophic biofilms along a gradient of hydraulic conditions. Compact and coalescent biofilms formed under elevated bed shear stress, whereas protruding clusters separated by troughs formed under reduced shear stress.

Flow and epiphyte growth effects on the thermal, optical and chemical microenvironment in the leaf phyllosphere of seagrass ().

Intensified coastal eutrophication can result in an overgrowth of seagrass leaves by epiphytes, which is a major threat to seagrass habitats worldwide, but little is known about how epiphytic biofilms affect the seagrass phyllosphere. The physico-chemical microenvironment of L. leaves with and without epiphytes was mapped with electrochemical, thermocouple and scalar irradiance microsensors as a function of four irradiance conditions (dark, low, saturating and high light) and two water flow velocities (approx.

Self-regulation and STEM persistence in minority and non-minority students across the first year of college.

Psychological factors have been implicated in STEM persistence but remain poorly understood. In particular, the role of self-regulation--the cognitive, behavioral, and emotional skills that allow individuals to work efficiently toward their desired goals, especially when under stress--has received minimal attention. Psychological factors may be particularly important for persistence by underrepresented minority (URM) students, many of whom face significant barriers to success in STEM.