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Muller, Cé,cile,Bang, Iel-Soo,Velayudhan, Jyoti,Karlinsey, Joyce,Papenfort, Kai,Vogel, Jö,rg,Fang, Ferric C. Blackwell Publishing Ltd 2009 Molecular microbiology Vol.71 No.5
<P>Summary</P><P>The alternative sigma factor &sgr;<SUP>E</SUP> is activated by unfolded outer membrane proteins (OMPs) and plays an essential role in <I>Salmonella</I> pathogenesis. The canonical pathway of &sgr;<SUP>E</SUP> activation in response to envelope stress involves sequential proteolysis of the anti-sigma factor RseA by the PDZ proteases DegS and RseP. Here we show that &sgr;<SUP>E</SUP> in <I>Salmonella enterica</I> sv. Typhimurium can also be activated by acid stress. A &sgr;<SUP>E</SUP>-deficient mutant exhibits increased susceptibility to acid pH and reduced survival in an acidified phagosomal vacuole. Acid activation of &sgr;<SUP>E</SUP>-dependent gene expression is independent of the unfolded OMP signal or the DegS protease but requires processing of RseA by RseP. The RseP PDZ domain is indispensable for acid induction, suggesting that acid stress may disrupt an inhibitory interaction between RseA and the RseP PDZ domain to allow RseA proteolysis in the absence of antecedent action of DegS. These observations demonstrate a novel environmental stimulus and activation pathway for the &sgr;<SUP>E</SUP> regulon that appear to be critically important during <I>Salmonella</I>–host cell interactions.</P>
The earliest phases of high-mass star formation, as seen in NGC 6334 by <i>Herschel</i>-HOBYS
Tigé,, J.,Motte, F.,Russeil, D.,Zavagno, A.,Hennemann, M.,Schneider, N.,Hill, T.,Nguyen Luong, Q.,Di Francesco, J.,Bontemps, S.,Louvet, F.,Didelon, P.,Kö,nyves, V.,André,, Ph.,Leuleu, Springer-Verlag 2017 Astronomy and astrophysics Vol.602 No.-
Valdé,s Herná,ndez, Maria del Carmen,Cox, Simon R.,Kim, Jaeil,Royle, Natalie A.,Muñ,oz Maniega, Susana,Gow, Alan J.,Anblagan, Devasuda,Bastin, Mark E.,Park, Jinah,Starr, John M.,Ward Elsevier 2017 NEUROBIOLOGY OF AGING Vol.52 No.-
<P>Structural measures of the hippocampus have been linked to a variety of memory processes and also to broader cognitive abilities. Gross volumetry has been widely used, yet the hippocampus has a complex formation, comprising distinct subfields which may be differentially sensitive to the deleterious effects of age, and to different aspects of cognitive performance. However, a comprehensive analysis of multidomain cognitive associations with hippocampal deformations among a large group of cognitively normal older adults is currently lacking. In 654 participants of the Lothian Birth Cohort 1936 (mean age = 72.5, SD = 0.71 years), we examined associations between the morphology of the hippocampus and a variety of memory tests (spatial span, letter-number sequencing, verbal recall, and digit backwards), as well as broader cognitive domains (latent measures of speed, fluid intelligence, and memory). Following correction for age, sex, and vascular risk factors, analysis of memory subtests revealed that only right hippocampal associations in relation to spatial memory survived type 1 error correction in subiculum and in CA1 at the head (<I>β</I> = 0.201, <I>p</I> = 5.843 × 10<SUP>−4</SUP>, outward), and in the ventral tail section of CA1 (<I>β</I> = −0.272, <I>p</I> = 1.347 × 10<SUP>−5</SUP>, inward). With respect to latent measures of cognitive domains, only deformations associated with processing speed survived type 1 error correction in bilateral subiculum (<I>β</I><SUB><I>absolute</I></SUB> ≤ 0.247, <I>p</I> < 1.369 × 10<SUP>−4</SUP>, outward), bilaterally in the ventral tail section of CA1 (<I>β</I><SUB><I>absolute</I></SUB> ≤ 0.242, <I>p</I> < 3.451 × 10<SUP>−6</SUP>, inward), and a cluster at the left anterior-to-dorsal region of the head (<I>β</I> = 0.199, <I>p</I> = 5.220 × 10<SUP>−6</SUP>, outward). Overall, our results indicate that a complex pattern of both inward and outward hippocampal deformations are associated with better processing speed and spatial memory in older age, suggesting that complex shape-based hippocampal analyses may provide valuable information beyond gross volumetry.</P>
Spiral density waves in a young protoplanetary disk
Pé,rez, Laura M.,Carpenter, John M.,Andrews, Sean M.,Ricci, Luca,Isella, Andrea,Linz, Hendrik,Sargent, Anneila I.,Wilner, David J.,Henning, Thomas,Deller, Adam T.,Chandler, Claire J.,Dullemond, American Association for the Advancement of Scienc 2016 Science Vol.353 No.6307
<P>Gravitational forces are expected to excite spiral density waves in protoplanetary disks, disks of gas and dust orbiting young stars. However, previous observations that showed spiral structure were not able to probe disk midplanes, where most of the mass is concentrated and where planet formation takes place. Using the Atacama Large Millimeter/submillimeter Array, we detected a pair of trailing symmetric spiral arms in the protoplanetary disk surrounding the young star Elias 2-27. The arms extend to the disk outer regions and can be traced down to the midplane. These millimeter-wave observations also reveal an emission gap closer to the star than the spiral arms. We argue that the observed spirals trace shocks of spiral density waves in the midplane of this young disk.</P>