Catálogo de publicaciones - revistas

<jats:title>Can you spot a speck of space dust?</jats:title> <jats:p> NASA's Stardust spacecraft has been collecting cosmic dust: Aerogel tiles and aluminum foil sat for nearly 200 days in the interstellar dust stream before returning to Earth. Citizen scientists identified most of the 71 tracks where particles were caught in the aerogel, and scanning electron microscopy revealed 25 craterlike features where particles punched through the foil. By performing trajectory and composition analysis, Westphal <jats:italic>et al.</jats:italic> report that seven of the particles may have an interstellar origin. These dust particles have surprisingly diverse mineral content and structure as compared with models of interstellar dust based on previous astronomical observations. </jats:p> <jats:p> <jats:italic>Science</jats:italic> , this issue p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6198" page="786" related-article-type="in-this-issue" vol="345" xlink:href="10.1126/science.1252496">786</jats:related-article> </jats:p>

<jats:title>Clues to a mystery with RAVE results</jats:title> <jats:p> An unknown interloper systematically picks off light from galactic sources, snatching at specific wavelengths ranging from the ultraviolet to the infrared. The cause of what astronomers term diffuse interstellar bands (DIBs) still evades identification. Kos <jats:italic>et al.</jats:italic> combined nearly 500,000 stellar spectra from the RAVE survey to make a telling map that may clue us in further. This pseudo–three-dimensional map shows the distribution of the carrier that absorbs light at 862 nm, and it closely follows a separate map of interstellar dust, but with a significantly larger scale height in the Galactic plane. Though this is only one DIB of many, this analysis sets a path for the future study of others. </jats:p> <jats:p> <jats:italic>Science</jats:italic> , this issue p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6198" page="791" related-article-type="in-this-issue" vol="345" xlink:href="10.1126/science.1253171">791</jats:related-article> </jats:p>

<jats:title>Large-scale robotic self-assembly</jats:title> <jats:p> When individuals swarm, they must somehow communicate to direct collective motion. Swarms of robots need to deal with outliers, such as robots that move more slowly than the rest. Rubenstein <jats:italic>et al.</jats:italic> created a large swarm of programmed robots that can form collaborations using only local information. The robots could communicate only with nearby members, within about three times their diameter. They were able to assemble into complex preprogrammed shapes. If the robots' formation hit snags when they bumped into one another or because of an outlier, additional algorithms guided them to rectify their collective movements. </jats:p> <jats:p> <jats:italic>Science</jats:italic> , this issue p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6198" page="795" related-article-type="in-this-issue" vol="345" xlink:href="10.1126/science.1254295">795</jats:related-article> </jats:p>

<jats:title>The future of RNA origami writ large</jats:title> <jats:p> Researchers have long fabricated intricate nanostructures from carefully linked DNA strands. Now they can use RNA made by gene expression, which avoids the costly strand synthesis and lengthy annealing steps necessary with DNA origami. Geary <jats:italic>et al.</jats:italic> used molecular modeling to extend the size of folded RNA origami structures (see the Perspective by Leontis and Westhof). The modeling revealed assembly patterns for linking single-stranded RNA into A-form helices. The authors created two-dimensional structures as large as 660 nucleotides on mica surfaces. </jats:p> <jats:p> <jats:italic>Science</jats:italic> , this issue p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6198" page="799" related-article-type="in-this-issue" vol="345" xlink:href="10.1126/science.1253920">799</jats:related-article> ; see also p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6198" page="732" related-article-type="in-this-issue" vol="345" xlink:href="10.1126/science.1257989">732</jats:related-article> </jats:p>

<jats:title>Setting the stage for release of oxygen</jats:title> <jats:p> Plants transform water into the oxygen we breathe using a protein-bound cluster of four manganese (Mn) ions and a calcium ion. Cox <jats:italic>et al.</jats:italic> now establish the precise electronic structure in that cluster immediately before formation of the O-O bond (see the Perspective by Britt and Oyala). Using the technique of electron paramagnetic resonance spectroscopy, they confirm a hypothesis that all four Mn ions are octahedrally coordinated and in the 4+ oxidation state. Such clues to the efficiency of the photosynthetic process, so essential to life on Earth, may also facilitate the development of artificial waters-plitting catalysts. </jats:p> <jats:p> <jats:italic>Science</jats:italic> , this issue p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6198" page="804" related-article-type="in-this-issue" vol="345" xlink:href="10.1126/science.1254910">804</jats:related-article> ; see also p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6198" page="736" related-article-type="in-this-issue" vol="345" xlink:href="10.1126/science.1258008">736</jats:related-article> </jats:p>

<jats:title>Strangleweed shares too much information</jats:title> <jats:p> Because RNA normally functions within an individual cell, we generally think that we keep our RNAs to ourselves. Kim <jats:italic>et al.</jats:italic> now show that the parasitic dodder plant breaks that rule. When dodder attacks a host plant, it opens up a conduit through which messenger and perhaps other regulatory RNAs are exchanged between parasite and host. Because a single dodder plant can attack multiple hosts, such exchanges may underlie instances of genes transferring between species. </jats:p> <jats:p> <jats:italic>Science</jats:italic> , this issue p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6198" page="808" related-article-type="in-this-issue" vol="345" xlink:href="10.1126/science.1253122">808</jats:related-article> </jats:p>