Catálogo de publicaciones - revistas

<jats:title>Conspiring interactions in a cuprate</jats:title> <jats:p> More than 30 years after the discovery of high-temperature superconductivity in copper oxides, its mechanism remains a mystery. Electron pairing mediated solely by lattice vibrations—phonons—is thought to be insufficient to account for the high transition temperatures. He <jats:italic>et al.</jats:italic> found a rapid and correlated increase of the superconducting gap and electron-phonon interactions as the chemical composition of their bismuth-based cuprate samples was varied across a critical doping concentration. The interplay of electron-phonon with electron-electron interactions may lead to enhanced transition temperatures. </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="6410" page="62" related-article-type="in-this-issue" vol="362" xlink:href="10.1126/science.aar3394">62</jats:related-article> </jats:p>

<jats:title>Insulator or a metal?</jats:title> <jats:p> When a metal is cooled to low temperatures and placed in an external magnetic field, its resistivity may oscillate as the magnitude of the field is varied. Seeing these so-called quantum oscillations in an insulating material would be very unusual. Xiang <jats:italic>et al.</jats:italic> report such findings in the insulator ytterbium dodecaboride (YbB <jats:sub>12</jats:sub> ) (see the Perspective by Ong). In addition to oscillations in resistivity, the authors observed oscillations in the magnetic torque. The results present a challenge to theories that aim to explain the insulating state of YbB <jats:sub>12</jats:sub> . </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="6410" page="65" related-article-type="in-this-issue" vol="362" xlink:href="10.1126/science.aap9607">65</jats:related-article> ; see also p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6410" page="32" related-article-type="in-this-issue" vol="362" xlink:href="10.1126/science.aau3840">32</jats:related-article> </jats:p>

<jats:title>Hot carriers reducing thermal barriers</jats:title> <jats:p> Plasmonic catalysts can generate hot charge carriers that can activate reactants and, in turn, reduce the overall barrier to a reaction. Zhou <jats:italic>et al.</jats:italic> studied the decomposition of ammonia to hydrogen on a copper alloy nanostructure that absorbed light and generated electrons that activated nitrogen atoms on ruthenium surface atoms (see the Perspective by Cortés). By measuring reaction rates at different wavelengths, light intensities, and catalyst surface temperatures, the light-induced reduction of the apparent activation barrier was quantified. </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="6410" page="69" related-article-type="in-this-issue" vol="362" xlink:href="10.1126/science.aat6967">69</jats:related-article> ; see also p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6410" page="28" related-article-type="in-this-issue" vol="362" xlink:href="10.1126/science.aav1133">28</jats:related-article> </jats:p>

<jats:title>Secrets revealed by kangaroo teeth</jats:title> <jats:p>The teeth of mammals display complex adaptations to diet and can thus provide a window into the environments of extinct species. Couzens and Prideaux used such a window to examine the expansion and diversification of kangaroos, Australia's largest herbivores (see the Perspective by Polly). True kangaroos diversified not in response to drying in the Miocene, as suggested by molecular results, but rather as grasslands expanded during the Pliocene. Furthermore, the now-extinct short-faced kangaroos were not declining because of increases in aridity at the end of the Pleistocene but instead were experiencing an increase in dietary divergence.</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="6410" page="72" related-article-type="in-this-issue" vol="362" xlink:href="10.1126/science.aas8788">72</jats:related-article> ; see also p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6410" page="25" related-article-type="in-this-issue" vol="362" xlink:href="10.1126/science.aav1602">25</jats:related-article> </jats:p>

<jats:title>Seasonal flu by ZIP code</jats:title> <jats:p> Influenza virus strikes communities in northern latitudes during winter, straining health care provision almost to the breaking point. Change in environmental humidity is a key driver, but many other seasonal and social factors contribute. Dalziel <jats:italic>et al.</jats:italic> obtained a geographical distribution of doctor visits for influenza-like illness for more than 600 U.S. cities (see the Perspective by Wallinga). Some ZIP codes regularly experienced sharply defined peaks of cases, or intense epidemics, and others showed a longer, more diffuse influenza season. The surges tended to occur in smaller cities with less residential density and lower household incomes. Larger, more densely populated cities had more-diffuse epidemics, presumably because of higher rates of personal contact, which makes influenza transmission less subject to climate variation. </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="6410" page="75" related-article-type="in-this-issue" vol="362" xlink:href="10.1126/science.aat6030">75</jats:related-article> ; see also p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6410" page="29" related-article-type="in-this-issue" vol="362" xlink:href="10.1126/science.aav1003">29</jats:related-article> </jats:p>

<jats:title>Tree diversity improves forest productivity</jats:title> <jats:p> Experimental studies in grasslands have shown that the loss of species has negative consequences for ecosystem functioning. Is the same true for forests? Huang <jats:italic>et al.</jats:italic> report the first results from a large biodiversity experiment in a subtropical forest in China. The study combines many replicates, realistic tree densities, and large plot sizes with a wide range of species richness levels. After 8 years of the experiment, the findings suggest strong positive effects of tree diversity on forest productivity and carbon accumulation. Thus, changing from monocultures to more mixed forests could benefit both restoration of biodiversity and mitigation of climate change. </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="6410" page="80" related-article-type="in-this-issue" vol="362" xlink:href="10.1126/science.aat6405">80</jats:related-article> </jats:p>

<jats:title>Educating for economic rationality</jats:title> <jats:p> The hypothesis that education enhances economic decision-making has been surprisingly underexplored. Kim <jats:italic>et al.</jats:italic> studied this question using a randomized control trial in a sample of 2812 girls in secondary schools in Malawi. Four years after providing financial support for a year's schooling, they presented the subjects with a set of decision problems (for example, allocating funds to immediate versus future expenses) that test economic rationality. The education intervention enhanced both educational outcomes and economic rationality as measured by consistency with utility maximization in the long run. </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="6410" page="83" related-article-type="in-this-issue" vol="362" xlink:href="10.1126/science.aar6987">83</jats:related-article> </jats:p>

<jats:title>Gene editing and muscular dystrophy</jats:title> <jats:p> Duchenne muscular dystrophy (DMD) is characterized by progressive muscle weakness and a shortened life span. The disease is caused by mutations that reduce or prevent expression of dystrophin, an essential structural protein in skeletal and heart muscle. The gene editing technology CRISPR-Cas9 can correct disease-causing mutations and has yielded promising results in mouse models of DMD. In a small, short-term study, Amoasii <jats:italic>et al.</jats:italic> tested this strategy in a dog model of DMD that exhibits many features of the human disease. Intramuscular or systemic delivery of the gene editing components resulted in a substantial increase in dystrophin protein levels in skeletal and heart muscle. Restoration of dystrophin expression was accompanied by improved muscle histology. </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="6410" page="86" related-article-type="in-this-issue" vol="362" xlink:href="10.1126/science.aau1549">86</jats:related-article> </jats:p>

<jats:title>Some (re)programming notes on cancer</jats:title> <jats:p> Epithelial cancers develop resistance to targeted therapies in a number of different ways. Several cancer types do so by undergoing phenotypic conversion to a highly aggressive cancer called small cell neuroendocrine carcinoma (SCNC). Whether distinct cancer types accomplish this “reprogramming” through the same mechanism has been unclear. Park <jats:italic>et al.</jats:italic> show that the same set of oncogenic factors transforms both normal lung and normal prostate epithelial cells into SCNCs that resemble clinical samples (see the Perspective by Kareta and Sage). This convergence of molecular pathways could potentially simplify the development of new therapies for SCNC, which is currently untreatable. </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="6410" page="91" related-article-type="in-this-issue" vol="362" xlink:href="10.1126/science.aat5749">91</jats:related-article> ; see also p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6410" page="30" related-article-type="in-this-issue" vol="362" xlink:href="10.1126/science.aav1044">30</jats:related-article> </jats:p>

<jats:p>A weekly roundup of information on newly offered instrumentation, apparatus, and laboratory materials of potential interest to researchers.</jats:p>