Getting Growers to Go Digital: The Power of a Positive User Experience

Using web-based applications is an innovative approach for delivery of Extension resources. For example, myFields.info is a mobile-friendly application focused on directing stakeholders to information at the field level. Acceptance and diffusion of such applications depends on initial experiences resulting from traditional face-to-face interactions with Extension personnel. We found that crop school participants involved in an Extension training event for a web-based sampling plan showed increased willingness after the training to incorporate sampling plans in their management decisions and share relevant data with others. Specifically, our study demonstrated the value of providing hands-on experience when attempting to encourage stakeholders to accept technologies

Symmetry Protected Topological phases and Generalized Cohomology

We discuss the classification of SPT phases in condensed matter systems. We review Kitaev's argument that SPT phases are classified by a generalized cohomology theory, valued in the spectrum of gapped physical systems. We propose a concrete description of that spectrum and of the corresponding cohomology theory. We compare our proposal to pre-existing constructions in the literature.Comment: 27 pages, 10 figures. v2: citation updat

Ecophysiology of coral reef primary producers across an upwelling gradient in the tropical central Pacific

© The Author(s), 2020. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Johnson, M. D., Fox, M. D., Kelly, E. L. A., Zgliczynski, B. J., Sandin, S. A., & Smith, J. E. Ecophysiology of coral reef primary producers across an upwelling gradient in the tropical central Pacific. Plos One, 15(2), (2020): e0228448, doi:10.1371/journal.pone.0228448.Upwelling is an important source of inorganic nutrients in marine systems, yet little is known about how gradients in upwelling affect primary producers on coral reefs. The Southern Line Islands span a natural gradient of inorganic nutrient concentrations across the equatorial upwelling region in the central Pacific. We used this gradient to test the hypothesis that benthic autotroph ecophysiology is enhanced on nutrient-enriched reefs. We measured metabolism and photophysiology of common benthic taxa, including the algae Porolithon, Avrainvillea, and Halimeda, and the corals Pocillopora and Montipora. We found that temperature (27.2–28.7°C) was inversely related to dissolved inorganic nitrogen (0.46–4.63 μM) and surface chlorophyll a concentrations (0.108–0.147 mg m-3), which increased near the equator. Contrary to our prediction, ecophysiology did not consistently track these patterns in all taxa. Though metabolic rates were generally variable, Porolithon and Avrainvillea photosynthesis was highest at the most productive and equatorial island (northernmost). Porolithon photosynthetic rates also generally increased with proximity to the equator. Photophysiology (maximum quantum yield) increased near the equator and was highest at northern islands in all taxa. Photosynthetic pigments also were variable, but chlorophyll a and carotenoids in Avrainvillea and Montipora were highest at the northern islands. Phycobilin pigments of Porolithon responded most consistently across the upwelling gradient, with higher phycoerythrin concentrations closer to the equator. Our findings demonstrate that the effects of in situ nutrient enrichment on benthic autotrophs may be more complex than laboratory experiments indicate. While upwelling is an important feature in some reef ecosystems, ancillary factors may regulate the associated consequences of nutrient enrichment on benthic reef organisms.This work was supported by funding from the Moore Family Foundation, the Gordon and Betty Moore Foundation, the Scripps family, and anonymous donors. The funders had no role in study design, data collection and analysis, or preparation of the manuscript