Affordable Diffusion Microchamber Array Designs for Isolating Microbes in Classrooms and Laboratories

Diffusion microchamber array (DMA) devices have provided contemporary microbiologists with a successful alternative to the century-old plating method using petri dishes to isolate and cultivate environmental bacteria. The “ichip” DMA device, developed by the research group of Slava Epstein, is exemplary of this technology, using membranes to culture rare or otherwise nonmodel bacterial taxa, whereby the target cells are nourished by environmental medium across the separating membrane.

Structural Diversity in Early-Stage Biofilm Formation on Microplastics Depends on Environmental Medium and Polymer Properties

Plastics entering the environment can not only undergo physical degradation and fragmentation processes, but they also tend to be colonized by microorganisms. Microbial colonization and the subsequent biofilm formation on plastics can alter their palatability to organisms and result in a higher ingestion as compared to pristine plastics. To date, the early stage of biofilm formation on plastic materials has not been investigated in context of the environmental medium and polymer properties. We explored the early-stage biofilm formation on polyamide (PA), polyethylene terephthalate (PET), and polyvinyl chloride (PVC) after incubation in freshwater and artificial seawater and categorized the structural diversity on images obtained via scanning electron microscopy. Furthermore, by the measurement of the initial ζ-potential of the plastic materials, we found that PA with the highest negative ζ-potential tended to have the highest structural diversity, followed by PET and PVC after incubation in freshwater. However, PVC with the lowest negative ζ-potential showed the highest structural diversity after incubation in seawater, indicating that the structural diversity is additionally dependent on the incubation medium. Our results give insights into how the incubation medium and polymer properties can influence the early-stage biofilm formation of just recently environmentally exposed microplastics. These differences are responsible for whether organisms may ingest microplastic particles with their food or not.

Office Plant as a mediating technology of organization

This chapter is dedicated to the office plant. The office plant takes on different roles: as environmental medium, it transforms offices into natural habitats. As medium of organization, it shapes everyday work life and its social relations. Based on artistic documentations (of office plants) and a history of knowledge of indoor plants and their cultivation, the office plant’s career is retraced and reconstructed—from a seemingly inconsequential prop of office organization to an agential medium that retains its efficacy even (or especially) under conditions of digitalization and virtualization.

Formats

With the umbrella term formats, this chapter explores the history of technical enhancements of swarm research between 1930 and 1980. It is concerned with the various attempts that were made to gain quantitative and formalizable access to the swarm by suppressing noise. Efforts were made to record swarms with optical media in a variety of experimental systems, and in the open sea researchers additionally tried to make swarms visible by means of innovative diving techniques and sonar technology. Again and again, however, disruptive forces like the internal movements of the collectives or the distortive effects of the environmental medium of water interrupted the acquisition of data. Empirical research thus found itself mired in a ‘technological morass.’