Catálogo de publicaciones - revistas

<jats:title>Quantum cats here and there</jats:title> <jats:p> The story of Schrödinger's cat being hidden away in a box and being both dead and alive is often invoked to illustrate the how peculiar the quantum world can be. On a twist of the dead/alive behavior, Wang <jats:italic>et al.</jats:italic> now show that the cat can be in two separate locations at the same time. Constructing their cat from coherent microwave photons, they show that the state of the “electromagnetic cat” can be shared by two separated cavities. Going beyond common-sense absurdities of the classical world, the ability to share quantum states in different locations could be a powerful resource for quantum information processing. </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="6289" page="1087" related-article-type="in-this-issue" vol="352" xlink:href="10.1126/science.aaf2941">1087</jats:related-article> </jats:p>

<jats:title>Cold atoms do geometry</jats:title> <jats:p> Electrons in solids populate energy bands, which can be simulated in cold atom systems using optical lattices. The geometry of the corresponding wave functions determines the topological properties of the system, but getting a direct look is tricky. Fläschner <jats:italic>et al.</jats:italic> and Li <jats:italic>et al.</jats:italic> measured the detailed structure of the band wave functions in hexagonal optical lattices, one resembling a boron-nitride and the other a graphene lattice. These techniques will make it possible to explore more complex situations that include the effects of interactions. </jats:p> <jats:p> <jats:italic>Science</jats:italic> , this issue pp. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6289" page="1091" related-article-type="in-this-issue" vol="352" xlink:href="10.1126/science.aad4568">1091</jats:related-article> and <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6289" page="1094" related-article-type="in-this-issue" vol="352" xlink:href="10.1126/science.aad5812">1094</jats:related-article> </jats:p>

<jats:title>Cold atoms do geometry</jats:title> <jats:p> Electrons in solids populate energy bands, which can be simulated in cold atom systems using optical lattices. The geometry of the corresponding wave functions determines the topological properties of the system, but getting a direct look is tricky. Fläschner <jats:italic>et al.</jats:italic> and Li <jats:italic>et al.</jats:italic> measured the detailed structure of the band wave functions in hexagonal optical lattices, one resembling a boron-nitride and the other a graphene lattice. These techniques will make it possible to explore more complex situations that include the effects of interactions. </jats:p> <jats:p> <jats:italic>Science</jats:italic> , this issue pp. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6289" page="1091" related-article-type="in-this-issue" vol="352" xlink:href="10.1126/science.aad4568">1091</jats:related-article> and <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6289" page="1094" related-article-type="in-this-issue" vol="352" xlink:href="10.1126/science.aad5812">1094</jats:related-article> </jats:p>

<jats:title>The fuel for fungal enzymes</jats:title> <jats:p> Many microorganisms have specialized enzymes to target and break down plant biomass. In fungi, these enzymes, called lytic polysaccharide monooxygenases (LPMOs), partner with electron transfer partners to oxidatively cleave the polysaccharide backbone of lignocellulosic polymers. Kracher <jats:italic>et al.</jats:italic> examined several potential extracellular electron transfer partners for LPMO, including other enzymes and small redoxactive metabolites (see the Perspective by Martínez). All three were able to donate electrons to the single-copper active site. Such versatility helps these fungi adapt to a range of redox conditions and potentially use other extracellular electron donors to fuel biomass degradation. </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="6289" page="1098" related-article-type="in-this-issue" vol="352" xlink:href="10.1126/science.aaf3165">1098</jats:related-article> ; see also p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6289" page="1050" related-article-type="in-this-issue" vol="352" xlink:href="10.1126/science.aaf8920">1050</jats:related-article> </jats:p>

<jats:title>Calcium signals the making of symbiosis</jats:title> <jats:p> Plant cell nuclei respond to signals from symbiotic nitrogenfixing rhizobial bacteria or arbuscular mycorrhizal fungi with oscillating Ca <jats:sup>2+</jats:sup> release. Charpentier <jats:italic>et al.</jats:italic> identified a trio of responsible Ca <jats:sup>2+</jats:sup> channels in a legume. These channels contain nuclear localization signals and are expressed in root cell nuclear envelopes. The channels function early in the establishment of symbiosis to produce oscillations in Ca <jats:sup>2+</jats:sup> release from nuclear stores. </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="6289" page="1102" related-article-type="in-this-issue" vol="352" xlink:href="10.1126/science.aae0109">1102</jats:related-article> </jats:p>

<jats:title>A new metal scavenger for bacteria</jats:title> <jats:p> All cells must find a way to acquire trace metals. Bacteria and plants scavenge iron, for instance, by synthesizing and releasing iron-chelating compounds called siderophores. Ghssein <jats:italic>et al.</jats:italic> describe three enzymes in <jats:italic>Staphylococcus aureus</jats:italic> that are responsible for the biosynthesis of another type of metallophore (see the Perspective by Nolan). Metabolomics and a range of biochemical assays show that this compound, named staphylopine, is involved in the uptake of a range of metals, depending on the growth environment. The genes required for staphylopine biosynthesis are conserved across a number of pathogenic bacteria and are similar to those for a broad-spectrum metallophore produced by plants. </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="6289" page="1105" related-article-type="in-this-issue" vol="352" xlink:href="10.1126/science.aaf1018">1105</jats:related-article> ; see also p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6289" page="1055" related-article-type="in-this-issue" vol="352" xlink:href="10.1126/science.aaf8755">1055</jats:related-article> </jats:p>

<jats:title>From neutral to new</jats:title> <jats:p> Many of the particles in the troposphere are formed in situ, but what fraction of all tropospheric particles do they constitute and how exactly are they made? Bianchi <jats:italic>et al.</jats:italic> report results from a high-altitude research station. Roughly half of the particles were newly formed by the condensation of highly oxygenated multifunctional compounds. A combination of laboratory results, field measurements, and model calculations revealed that neutral nucleation is more than 10 times faster than ion-induced nucleation, that particle growth rates are size-dependent, and that new particle formation occurs during a limited time window. </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="6289" page="1109" related-article-type="in-this-issue" vol="352" xlink:href="10.1126/science.aad5456">1109</jats:related-article> </jats:p>

<jats:title>Narrowing down genetic loci of interest</jats:title> <jats:p> Often it can be difficult to identify a gene or genetic region that underlies a specific trait. Traditional mapping relies on naturally occurring recombination events but can be limited in resolution by the natural recombination frequency. Sadhu <jats:italic>et al.</jats:italic> used CRISPR technology to more easily map genomic sites of interest in yeast. The method systematically introduces local recombination events, allowing for the fine mapping of trait variants. They used their method to identify the causative mutation responsible for altered manganese sensitivity in yeast. </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="6289" page="1113" related-article-type="in-this-issue" vol="352" xlink:href="10.1126/science.aaf5124">1113</jats:related-article> </jats:p>

<jats:title>Genes and microbes converge in colitis</jats:title> <jats:p> Both host genetics and intestinal microbes probably contribute to a person's overall susceptibility to inflammatory bowel disease (IBD). The human gut microbe <jats:italic>Bacteroides fragilis</jats:italic> produces immunomodulatory molecules that it releases via outer membrane vesicles (OMVs). These molecules can protect mice from experimentally induced colitis. Chu <jats:italic>et al.</jats:italic> now find that OMV-mediated protection from colitis requires <jats:italic>Atg16l1</jats:italic> and <jats:italic>Nod2</jats:italic> genes whose human orthologs are associated with an increased risk for developing IBD. OMVs trigger an ATG16L1 and NOD2–dependent noncanonical autophagy pathway in dendritic cells (DCs). OMV-primed DCs, in turn, induce regulatory T cells in the intestine that protect against colitis. </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="6289" page="1116" related-article-type="in-this-issue" vol="352" xlink:href="10.1126/science.aad9948">1116</jats:related-article> </jats:p>

<jats:title>Phosphorylation cues exit from mitosis</jats:title> <jats:p> The entry and exit from the cell cycle are controlled by waves of protein phosphorylation and degradation events. Fujimitsu <jats:italic>et al.</jats:italic> describe the precise mechanism by which the cell cycle machinery controls exit from mitosis. The critical event is activation of a ubiquitin ligase, the anaphase-promoting complex or cyclosome (APC/C). The authors used purified components and the Xenopus egg extract system to show that two subunits of APC/C were directly phosphorylated by cyclin-dependent kinase 1 (CDK1). Phosphorylation of one subunit helped recruit CDK1 for further phosphorylation of another subunit. The second subunit interacted with the APC/C activator and target of anticancer therapy known as Cdc20. </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="6289" page="1121" related-article-type="in-this-issue" vol="352" xlink:href="10.1126/science.aad3925">1121</jats:related-article> </jats:p>