Catálogo de publicaciones - revistas

<jats:p>Earth's rapidly changing near-surface environment needs systematic observation to better manage future crop production, climates, and water quality.</jats:p>

<jats:p>Alloys based on molybdenum or niobium may allow the high-temperature components of jet engines to run hotter and more efficiently.</jats:p>

<jats:p>An exceptionally long computer simulation offers a glimpse of molecular events leading to methane hydrate formation.</jats:p>

<jats:p>The maize genome sequence will allow further analyses of genetic diversity and the genetic basis for traits critical to plant breeding.</jats:p>

<jats:p>Declines in North American megafauna populations began before the Clovis period and were the cause, not the result, of vegetation changes and increased fires.</jats:p>

<jats:title>Blod</jats:title> <jats:p>Blod.</jats:p>

<jats:title>A-Maize-ing</jats:title> <jats:p> Maize is one of our oldest and most important crops, having been domesticated approximately 9000 years ago in central Mexico. <jats:bold> Schnable <jats:italic>et al.</jats:italic> </jats:bold> (p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" page="1112" related-article-type="in-this-issue" vol="326" xlink:href="10.1126/science.1178534">1112</jats:related-article> ; see the cover) present the results of sequencing the B73 inbred maize line. The findings elucidate how maize became diploid after an ancestral doubling of its chromosomes and reveals transposable element movement and activity and recombination. <jats:bold> Vielle-Calzada <jats:italic>et al.</jats:italic> </jats:bold> (p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" page="1078" related-article-type="in-this-issue" vol="326" xlink:href="10.1126/science.1178437">1078</jats:related-article> ) have sequenced the <jats:italic>Palomero Toluqueño</jats:italic> ( <jats:italic>Palomero</jats:italic> ) landrace, a highland popcorn from Mexico, which, when compared to the B73 line, reveals multiple loci impacted by domestication. <jats:bold> Swanson-Wagner <jats:italic>et al.</jats:italic> </jats:bold> (p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" page="1118" related-article-type="in-this-issue" vol="326" xlink:href="10.1126/science.1178294">1118</jats:related-article> ) exploit possession of the genome to analyze expression differences occurring between lines. The identification of single nucleotide polymorphisms and copy number variations among lines was used by <jats:bold> Gore <jats:italic>et al.</jats:italic> </jats:bold> (p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" page="1115" related-article-type="in-this-issue" vol="326" xlink:href="10.1126/science.1177837">1115</jats:related-article> ) to generate a Haplotype map of maize. While chromosomal diversity in maize is high, it is likely that recombination is the major force affecting the levels of heterozygosity in maize. The availability of the maize genome will help to guide future agricultural and biofuel applications (see the Perspective by <jats:bold> <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="5956" page="1071" related-article-type="in-this-issue" vol="326" xlink:href="10.1126/science.1183463">Feuillet and Eversole</jats:related-article> </jats:bold> ). </jats:p>

<jats:p>During sleep, memories can be influenced in a specific and systematic manner.</jats:p>

<jats:title>Cosmic Acceleration</jats:title> <jats:p> Cosmic rays are thought to be accelerated in the shock waves produced by supernova explosions and can generate gamma rays when they interact with interstellar particles and radiation. Starburst galaxies, with their increased star formation rates, increased stellar explosion rates, and high densities of gas and radiation fields, are considered to be promising sources of gamma-ray emission. Using the High Energy Stereoscopic System (H.E.S.S) array of telescopes, <jats:bold> Acero <jats:italic>et al.</jats:italic> </jats:bold> (p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" page="1080" related-article-type="in-this-issue" vol="326" xlink:href="10.1126/science.1178826">1080</jats:related-article> , published online 24 September) report the detection of gamma rays from one of the closest starburst galaxies, NGC 253. NGC 253 is a spiral galaxy, similar to our own Galaxy, except that its nucleus is undergoing an episode of intense star formation. The H.E.S.S. findings confirm that cosmic-ray acceleration is indeed efficient in starburst galaxies and open up new ways to understand cosmic-ray acceleration. </jats:p>

<jats:title>Hairy Polygon Solution</jats:title> <jats:p> The packing of rods on the surface of a sphere leads to packing defects at the opposite poles. It is, however, possible to flat-pack rods onto a torus. This topological problem is well known as the hairy ball theorem, and arises when you place spherical particles inside a nematic liquid crystal. <jats:bold> Lapointe <jats:italic>et al.</jats:italic> </jats:bold> (p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" page="1083" related-article-type="in-this-issue" vol="326" xlink:href="10.1126/science.1176587">1083</jats:related-article> ) considered the packing of liquid crystal molecules onto lithographically fabricated polygons and found that the number of dipoles that formed depended upon whether the polygon had an odd or even number of sides. The defect structures were attracted to each other, such that the liquid crystal could pull together the particles in a form of controlled self-assembly. </jats:p>