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Biofilm matrix composition and localization [Microbiology]

PNAS Early Edition Articles - Wed, 08/26/2015 - 12:04
Biofilm formation is a complex, ordered process. In the opportunistic pathogen Pseudomonas aeruginosa, Psl and Pel exopolysaccharides and extracellular DNA (eDNA) serve as structural components of the biofilm matrix. Despite intensive study, Pel’s chemical structure and spatial localization within mature biofilms remain unknown. Using specialized carbohydrate chemical analyses, we unexpectedly...

Single-molecule FRET studies on neuronal NOS [Biochemistry]

PNAS Early Edition Articles - Wed, 08/26/2015 - 12:04
Mechanisms that regulate the nitric oxide synthase enzymes (NOS) are of interest in biology and medicine. Although NOS catalysis relies on domain motions, and is activated by calmodulin binding, the relationships are unclear. We used single-molecule fluorescence resonance energy transfer (FRET) spectroscopy to elucidate the conformational states distribution and associated...

Intracisternal arrays within the native Golgi [Cell Biology]

PNAS Early Edition Articles - Wed, 08/26/2015 - 12:04
We acquired molecular-resolution structures of the Golgi within its native cellular environment. Vitreous Chlamydomonas cells were thinned by cryo-focused ion beam milling and then visualized by cryo-electron tomography. These tomograms revealed structures within the Golgi cisternae that have not been seen before. Narrow trans-Golgi lumina were spanned by asymmetric membrane-associated...

Commissioning of Ignalina solid waste facilities under way

World Nuclear News - Wed, 08/26/2015 - 08:38
Cold testing - one of the first stages of the commissioning process - has started at the new Solid Waste Management and Storage Facilities at the shut down Ignalina nuclear power plant in Lithuania.

Canadian accident study puts risks into perspective

World Nuclear News - Wed, 08/26/2015 - 08:05
A Canadian Nuclear Safety Commission study has concluded that there would be no detectable increase in cancer risk for most of the population from radiation released in a hypothetical severe nuclear accident.

Vanity Fair: Global Warming hitting Film Industry Hard – ‘How Extreme Weather Is Melting Hollywood’s Winter Shoots’

Climate Depot - Tue, 08/25/2015 - 20:06
Eric Holthaus, a meteorologist who works for Slate, says climate change may affect Hollywood in several ways: The frequency of extreme weather makes it harder to predict which areas of the world may have snow, rain, or sunny days during any given month. And Hollywood may not be able to rely on “locations that are [...]

Keel-laying for new US nuclear ship

World Nuclear News - Tue, 08/25/2015 - 16:10
The keel for the US Navy's second Gerald Ford-class nuclear-powered aircraft carrier, the John F Kennedy, has been laid at a ceremony in Newport News, Virginia.

Native root bacteria rescue a native plant [Ecology]

PNAS Early Edition Articles - Tue, 08/25/2015 - 09:22
Plants maintain microbial associations whose functions remain largely unknown. For the past 15 y, we have planted the annual postfire tobacco Nicotiana attenuata into an experimental field plot in the plant’s native habitat, and for the last 8 y the number of plants dying from a sudden wilt disease has...

Activating reserve olfactory epithelial stem cells [Neuroscience]

PNAS Early Edition Articles - Tue, 08/25/2015 - 09:22
Adult tissue stem cells can serve two broad functions: to participate actively in the maintenance and regeneration of a tissue or to wait in reserve and participate only when activated from a dormant state. The adult olfactory epithelium, a site for ongoing, life-long, robust neurogenesis, contains both of these functional...

Mechanical control of mitotic progression [Biophysics and Computational Biology]

PNAS Early Edition Articles - Tue, 08/25/2015 - 09:22
Despite the importance of mitotic cell rounding in tissue development and cell proliferation, there remains a paucity of approaches to investigate the mechanical robustness of cell rounding. Here we introduce ion beam-sculpted microcantilevers that enable precise force-feedback–controlled confinement of single cells while characterizing their progression through mitosis. We identify three...

Neurogenic delay of pallial progenitors [Neuroscience]

PNAS Early Edition Articles - Tue, 08/25/2015 - 09:22
The classical view of mammalian cortical development suggests that pyramidal neurons are generated in a temporal sequence, with all radial glial cells (RGCs) contributing to both lower and upper neocortical layers. A recent opposing proposal suggests there is a subgroup of fate-restricted RGCs in the early neocortex, which generates only...
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