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Patterned surfaces can enhance the sensitivity of laser desorption ionization mass spectrometry by segregating and concentrating analytes, but their fabrication can be challenging. Here, a simple method to fabricate substrates patterned with micrometer-scale wells that yield more accurate and sensitive mass spectrometry measurements compared to flat surfaces is described. The wells can also concentrate and localize cells and beads for cell-based assays.

Bacteria residing within biofilm communities can coordinate their behavior through cell-to-cell signaling. However, it remains unclear if these signals can also influence the behavior of distant cells that are not part of the community. Using a microfluidic approach, we find that potassium ion channel-mediated electrical signaling generated by a Bacillus subtilis biofilm can attract distant cells. Integration of experiments and mathematical modeling indicates that extracellular potassium emitted from the biofilm alters the membrane potential of distant cells, thereby directing their motility. This electrically mediated attraction appears to be a generic mechanism that enables cross-species interactions, as Pseudomonas aeruginosa cells also become attracted to the electrical signal released by the B. subtilis biofilm. Cells within a biofilm community can thus not only coordinate their own behavior but also influence the behavior of diverse bacteria at a distance through long-range electrical signaling. PAPERCLIP.

The American Deaf community for several decades has been involved in sometimes complicated and often contested ways of defining what it means to be Deaf. It is our thesis that the processes of identity construction and the recent discourse of Deaf identity are not unique phenomena at all but echo the experience of other embedded cultural groups around the world, particularly those that are stressed by the assertion of hegemony over them by others. We turn to 2 particular theorists, Jose Marti and W. E. B. DuBois, to help us understand both the dilemmas that Deaf people face and the possible solutions that they propose. This article argues that identities are constructed not just within Deaf communities but within the social contexts in which Deaf communities are embedded.

Cells that reside within a community can cooperate and also compete with each other for resources. It remains unclear how these opposing interactions are resolved at the population level. Here we investigate such an internal conflict within a microbial (Bacillus subtilis) biofilm community: cells in the biofilm periphery not only protect interior cells from external attack but also starve them through nutrient consumption. We discover that this conflict between protection and starvation is resolved through emergence of long-range metabolic co-dependence between peripheral and interior cells. As a result, biofilm growth halts periodically, increasing nutrient availability for the sheltered interior cells. We show that this collective oscillation in biofilm growth benefits the community in the event of a chemical attack. These findings indicate that oscillations support population-level conflict resolution by coordinating competing metabolic demands in space and time, suggesting new strategies to control biofilm growth., Cooperation and competition are complex social interactions that can have critical roles in biological communities. Cooperative behaviour often increases the overall fitness of the population through processes such as division [...]

The issue of professional ethics is often the subject of media attention. Currently in many parts of Australia, the behaviour of politicians, police, teachers, and journalists is under scrutiny, leading [...]

The American Deaf community for several decades has been involved in sometimes complicated and often contested ways of defining what it means to be Deaf. It is our thesis that the processes of identity construction and the recent discourse of Deaf identity are not unique phenomena at all but echo the experience of other embedded cultural groups around the world, particularly those that are stressed by the assertion of hegemony over them by others. We turn to 2 particular theorists, Jose Martí and W. E. B. DuBois, to help us understand both the dilemmas that Deaf people face and the possible solutions that they propose. This article argues that identities are constructed not just within Deaf communities but within the social contexts in which Deaf communities are embedded. [ABSTRACT FROM PUBLISHER]