Metabolite diversity among representatives of divergent Prochlorococcus ecotypes.

Approximately half of the annual carbon fixation on Earth occurs in the surface ocean through the photosynthetic activities of phytoplankton such as the ubiquitous picocyanobacterium Prochlorococcus. Ecologically distinct subpopulations (or ecotypes) of Prochlorococcus are central conduits of organic substrates into the ocean microbiome, thus playing important roles in surface ocean production. We measured the chemical profile of three cultured ecotype strains, observing striking differences among them that have implications for the likely chemical impact of Prochlorococcus subpopulations on their surroundings in the wild. Subpopulations differ in abundance along gradients of temperature, light, and nutrient concentrations, suggesting that these chemical differences could affect carbon cycling in different ocean strata and should be considered in models of Prochlorococcus physiology and marine carbon dynamics

Final Report of the Information Technology Subcommittee for the Campus Master Plan

Through its work, data collection, outreach, and careful review of various studies and information, the committee is led to conclude that as it moves forward with implementation of its Master Plan, UMass Boston has a tremendous opportunity to plan for and design spaces that support and promote the learning, teaching, and research requirements of the campus community. It is hoped that the recommended guidelines and standards outlined in this report will assist and inform the planning and design of new and renovated campus facilities and specifically address the technological needs of classrooms, laboratories, offices, informal study areas, and social spaces throughout the campus. As technology transforms rapidly and the needs of the campus evolve, the committee also recommends that this report is reviewed and updated on a yearly basis

Reversible Loss of Bernal Stacking during the Deformation of Few-Layer Graphene in Nanocomposites

The deformation of nanocomposites containing graphene flakes with different numbers of layers has been investigated with the use of Raman spectroscopy. It has been found that there is a shift of the 2D band to lower wavenumber and that the rate of band shift per unit strain tends to decrease as the number of graphene layers increases. It has been demonstrated that band broadening takes place during tensile deformation for mono- and bi-layer graphene but that band narrowing occurs when the number of graphene layers is more than two. It is also found that the characteristic asymmetric shape of the 2D Raman band for the graphene with three or more layers changes to a symmetrical shape above about 0.4% strain and that it reverts to an asymmetric shape on unloading. This change in Raman band shape and width has been interpreted as being due to a reversible loss of Bernal stacking in the few-layer graphene during deformation. It has been shown that the elastic strain energy released from the unloading of the inner graphene layers in the few-layer material (0.2 meV/atom) is similar to the accepted value of the stacking fault energies of graphite and few layer graphene. It is further shown that this loss of Bernal stacking can be accommodated by the formation of arrays of partial dislocations and stacking faults on the basal plane. The effect of the reversible loss of Bernal stacking upon the electronic structure of few-layer graphene and possibility of using it to modify the electronic structure of few-layer graphene is discussed

Final Report of the Information Technology Subcommittee for the Campus Master Plan

Through its work, data collection, outreach, and careful review of various studies and information, the committee is led to conclude that as it moves forward with implementation of its Master Plan, UMass Boston has a tremendous opportunity to plan for and design spaces that support and promote the learning, teaching, and research requirements of the campus community. It is hoped that the recommended guidelines and standards outlined in this report will assist and inform the planning and design of new and renovated campus facilities and specifically address the technological needs of classrooms, laboratories, offices, informal study areas, and social spaces throughout the campus. As technology transforms rapidly and the needs of the campus evolve, the committee also recommends that this report is reviewed and updated on a yearly basis

Activation of hTREK-1 by polyunsaturated fatty acids involves direct interaction

International audienceTREK-1 is a mechanosensitive channel activated by polyunsaturated fatty acids (PUFAs). Its activation is supposed to be linked to changes in membrane tension following PUFAs insertion. Here, we compared the effect of 11 fatty acids and ML402 on TREK-1 channel activation using the whole cell and the inside-out configurations of the patch-clamp technique. Firstly, TREK-1 activation by PUFAs is variable and related to the variable constitutive activity of TREK-1. We observed no correlation between TREK-1 activation and acyl chain length or number of double bonds suggesting that the bilayer-couple hypothesis cannot explain by itself the activation of TREK-1 by PUFAs. The membrane fluidity measurement is not modified by PUFAs at 10 µM. The spectral shift analysis in TREK-1-enriched microsomes indicates a K$_{D,TREK1}$ at 44 µM of C22:6 n-3. PUFAs display the same activation and reversible kinetics than the direct activator ML402 and activate TREK-1 in both whole-cell and inside-out configurations of patch-clamp suggesting that the binding site of PUFAs is accessible from both sides of the membrane, as for ML402. Finally, we proposed a two steps mechanism: first, insertion into the membrane, with no fluidity or curvature modifications at 10 µM, and then interaction with TREK-1 channel to open it

Rewilding: science, practice, and politics

Rewilding is being promoted as an ambitious alternative to current approaches to nature conservation. Interest is growing in popular and scientific literatures, and rewilding is the subject of significant comment and debate, outstripping scientific research and conservation practice. Projects and research are found the world over, with concentrations in Europe, North America, and on tropical islands. A common aim is to maintain, or increase, biodiversity, while reducing the impact of present and past human interventions through the restoration of species and ecological processes. The term rewilding has been applied to diverse concepts and practices. We review the historical emergence of the term and its various overlapping meanings, aims, and approaches, and illustrate this through a description of four flagship rewilding case studies. The science of rewilding has centered on three different historical baselines: the Pleistocene, the Holocene, and novel contemporary ecosystems. The choice of baseline has differing implications for conservation in a variety of contexts. Rewilding projects involve a range of practical components—such as passive management, reintroduction, and taxon substitution—some of which have attracted criticism. They also raise a series of political, social, and ethical concerns where they conflict with more established forms of environmental management. In conclusion, we summarize the different goals, approaches, tools, and contexts that account for the variations in rewilding and identify priorities for future research and practice

Exploration of the Northern Guaymas Basin

Author Posting. © The Oceanography Society, 2018. This article is posted here by permission of The Oceanography Society for personal use, not for redistribution. The definitive version was published in Oceanography 31, no. 1, supplement (2018): 39-41