Catálogo de publicaciones - revistas

<jats:p> DNA sequence variants are associated with factors and epigenetic states that modify gene expression and contribute to quantitative differences in traits. <jats:named-content content-type="related-content"> [Also see Reports by <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6159" page="744" related-article-type="in-this-issue" vol="342" xlink:href="10.1126/science.1242463"> Kilpinen <jats:italic>et al.</jats:italic> </jats:related-article> , <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6159" page="747" related-article-type="in-this-issue" vol="342" xlink:href="10.1126/science.1242429"> McVicker <jats:italic>et al.</jats:italic> </jats:related-article> , and <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6159" page="750" related-article-type="in-this-issue" vol="342" xlink:href="10.1126/science.1242510"> Kasowski <jats:italic>et al.</jats:italic> </jats:related-article> ] </jats:named-content> </jats:p>

<jats:p> Structural analyses help to elucidate a key step in DNA transcription. <jats:named-content content-type="related-content"> [Also see Research Article by <jats:ext-link xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="uri" xlink:href="http://www.sciencemag.org/content/342/6159/1238724.full"> Murakami <jats:italic>et al.</jats:italic> </jats:ext-link> ] </jats:named-content> </jats:p>

<jats:title>Optomechanically Entangled</jats:title> <jats:p> Quantum entanglement allows engineered quantum systems to exceed classical information processing bounds. <jats:bold> Palomaki <jats:italic>et al.</jats:italic> </jats:bold> (p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6159" page="710" related-article-type="in-this-issue" vol="342" xlink:href="10.1126/science.1244563">710</jats:related-article> , published online 3 October; see the Perspective by <jats:bold> <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6159" page="702" related-article-type="in-this-issue" vol="342" xlink:href="10.1126/science.1245797">Hammerer</jats:related-article> </jats:bold> ) extend this quantum resource into the domain of micromechanical oscillators by demonstrating entanglement between a microwave field and a mechanical oscillator. The mechanical part of the entangled state could then be transferred to a second microwave field. </jats:p>

<jats:title>Cold Thermoelectrics</jats:title> <jats:p> Thermoelectric effects—such as the creation of a voltage drop in response to a thermal gradient (known as the Seebeck effect)—can be used for a number of applications, including converting wasted heat into power. However, especially in solids that exhibit electronic interactions, this type of behavior is not well understood. <jats:bold> Brantut <jats:italic>et al.</jats:italic> </jats:bold> (p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6159" page="713" related-article-type="in-this-issue" vol="342" xlink:href="10.1126/science.1242308">713</jats:related-article> , published online 24 October; see the Perspective by <jats:bold> <jats:related-article issue="6159" page="" related-article-type="in-this-issue" vol="342">Heikkilä</jats:related-article> </jats:bold> ) studied the Seebeck effect in the very controllable setting of cold atomic gases. Two initially identical reservoirs of <jats:sup>6</jats:sup> Li atoms were connected using a quasi–two-dimensional channel, and the particle current after heating one of the reservoirs was measured. The atoms moved from the warmer to the cooler reservoir, the extent of which fit with theoretical predictions as the disorder in the channel and its geometry were varied. </jats:p>

<jats:title>Battery Breakdown</jats:title> <jats:p> Although a range of materials can be used for chemically storing electrical charge, many cannot be made into batteries that retain their capacity over many cycles. Failure may be because of secondary reactions, poisoning through the formation of surface coatings, or volumetric changes leading to fracture. <jats:bold> Ebner <jats:italic>et al.</jats:italic> </jats:bold> (p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6159" page="716" related-article-type="in-this-issue" vol="342" xlink:href="10.1126/science.1241882">716</jats:related-article> , published online 17 October) studied this last scenario in an operating battery using synchrotron x-ray tomographic microscopy, tracking both the chemical changes in the battery and the resulting mechanical changes in a tin oxide model system, which is known to undergo large volume changes. </jats:p>

<jats:title>Oxygen Control of Graphene Growth</jats:title> <jats:p> The growth of graphene on copper surfaces through the decomposition of hydrocarbons such as methane can result in a wide variety of crystal domain sizes and morphologies. <jats:bold> Hao <jats:italic>et al.</jats:italic> </jats:bold> (p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6159" page="720" related-article-type="in-this-issue" vol="342" xlink:href="10.1126/science.1243879">720</jats:related-article> , published online 24 October; see the cover) found that the presence of surface oxygen could limit the number of nucleation sites and allowed centimeter-scale domains to grow through a diffusion-limited mechanism. The electrical conductivity of the graphene was comparable to that of exfoliated graphene. </jats:p>

<jats:title>Which Side of the Moon?</jats:title> <jats:p> The far- and nearsides of the Moon are geologically different. Using high-precision crustal thickness maps derived from NASA's Gravity Recovery and Interior Laboratory (GRAIL) mission, <jats:bold> Miljković <jats:italic>et al.</jats:italic> </jats:bold> (p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6159" page="724" related-article-type="in-this-issue" vol="342" xlink:href="10.1126/science.1243224">724</jats:related-article> ) show that the distribution of lunar impact basins is also highly asymmetrical. Numerical simulations of impact basin formation coupled with three-dimensional simulations of the Moon's asymmetric thermal evolution suggest that lateral variations in temperature within the Moon's crust have a large effect on the final size of an impact basin. </jats:p>

<jats:title>Lighting Up Immunity</jats:title> <jats:p> T <jats:sub>H</jats:sub> 17 cells are CD4 <jats:sup>+</jats:sup> T helper cells that produce the proinflammatory cytokine interleukin-17. In the intestines, T <jats:sub>H</jats:sub> 17 cells protect the host from fungal and bacterial infections, and their proinflammatory function is linked with autoimmune diseases including inflammatory bowel disease. <jats:bold> Yu <jats:italic>et al.</jats:italic> </jats:bold> (p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6159" page="727" related-article-type="in-this-issue" vol="342" xlink:href="10.1126/science.1243884">727</jats:related-article> ) show that the molecular circadian clock directly regulates the differentiation of T <jats:sub>H</jats:sub> 17 cells in the intestine, which suggest that both nutrition and light are important environmental factors that directly regulate the immune response. </jats:p>

<jats:title> <jats:italic>Caulobacter</jats:italic> Chromosome </jats:title> <jats:p> Chromosomal DNA must be highly compacted to fit within the tiny volume of the cell, while at the same time it must maintain a conformation that allows critical cellular processes access to the genome. <jats:bold> Le <jats:italic>et al.</jats:italic> </jats:bold> (p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6159" page="731" related-article-type="in-this-issue" vol="342" xlink:href="10.1126/science.1242059">731</jats:related-article> , published online 24 October) analyzed the structure of the circular chromosome in the prokaryote <jats:italic>Caulobacter crescentus</jats:italic> by using chromosome conformation capture and deep-sequencing. Highly self-interacting regions (chromosomal interaction domains, or CIDs) were observed—similar to the topologically associated domains previously seen in eukaryotes. Supercoiling helped to establish CIDs, and CID boundaries were defined by highly expressed genes. CIDs appeared to be established during or shortly after DNA replication, and could potentially facilitate chromosomal segregation by preventing newly replicated chromosomes from becoming entangled. </jats:p>

<jats:title>Mitochondrial Fusion and Heart Development</jats:title> <jats:p> The role of mitochondria in fueling homeostatic cell processes is well appreciated, but whether and how they influence cell differentiation is much less clear. Using in vivo embryonic mouse models and mouse embryonic stem cell cultures, <jats:bold> Kasahara <jats:italic>et al.</jats:italic> </jats:bold> (p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6159" page="734" related-article-type="in-this-issue" vol="342" xlink:href="10.1126/science.1241359">734</jats:related-article> , published online 3 October) found that an intact mitochondrial fusion pathway was essential for the cellular signaling that drives mesodermal cell differentiation into cardiomyocytes. </jats:p>