Catálogo de publicaciones - revistas

<jats:title>Arenes get a light boost onto copper</jats:title> <jats:p> Insertion of palladium into an aryl halide bond is the first step in numerous variants of cross-coupling chemistry used to make carbon-carbon bonds. Copper is an appealing alternative catalyst for such reactions because of its abundance and downstream reactivity profile. However, this preliminary step, termed oxidative addition, is often prohibitively slow for the cheaper metal. Le <jats:italic>et al.</jats:italic> report a photocatalytic way around this problem. A photoredox catalyst paired with a silane can activate aryl bromides to react with copper, likely via aryl radicals. The copper in this case then catalyzes trifluoromethylation of the arenes. </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="6392" page="1010" related-article-type="in-this-issue" vol="360" xlink:href="10.1126/science.aat4133">1010</jats:related-article> </jats:p>

<jats:title>Controls on seed dormancy</jats:title> <jats:p> Herbivores and an inopportune cold snap can destroy fragile plant seedlings. Plants control the dormancy of their seeds in anticipation of more favorable growth conditions. Chen and Penfield analyzed the molecular controls on seed dormancy in the model plant <jats:italic>Arabidopsis thaliana.</jats:italic> Two genes and an antisense RNA, known from the process of vernalization, integrate ambient temperature to control seed dormancy via their opposing configurations. </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="6392" page="1014" related-article-type="in-this-issue" vol="360" xlink:href="10.1126/science.aar7361">1014</jats:related-article> </jats:p>

<jats:title>Predation favors the unadventurous</jats:title> <jats:p> Selection is likely to shape behavior by acting on behavioral differences between individuals. Testing this idea has been challenging. Lapiedra <jats:italic>et al.</jats:italic> took advantage of a chain of small islands in the Caribbean colonized by anole lizards. A series of repeated behavioral selection experiments were set up in which brown anole populations were established with and without predators. On predator-free islands, animals that were more exploratory were favored, whereas when predators were present, less adventurous animals survived better. Selection for behavior occurred simultaneously with morphological selection but was predominant when predators were present. </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="6392" page="1017" related-article-type="in-this-issue" vol="360" xlink:href="10.1126/science.aap9289">1017</jats:related-article> </jats:p>

<jats:title>Curtailed conversations</jats:title> <jats:p>Most articles written about U.S. politics in the past few years have mentioned the increasing polarization of the electorate. But is this real, or does it merely reflect the increasing polarization of the media? Chen and Rohla estimate that in 2016, Thanksgiving dinners in which the hosts and guests lived in oppositely voting precincts were up to 50 minutes shorter than same-party-precinct dinners. That is, family members, adjured to avoid talking about contentious subjects, may have simply talked less.</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="6392" page="1020" related-article-type="in-this-issue" vol="360" xlink:href="10.1126/science.aaq1433">1020</jats:related-article> </jats:p>

<jats:title>Founder effects in modern populations</jats:title> <jats:p> The genomes of ancient humans can reveal patterns of early human migration (see the Perspective by Achilli <jats:italic>et al.</jats:italic> ). Iceland has a genetically distinct population, despite relatively recent settlement (∼1100 years ago). Ebenesersdóttir <jats:italic>et al.</jats:italic> examined the genomes of ancient Icelandic people, dating to near the colonization of Iceland, and compared them with modernday Icelandic populations. The ancient DNA revealed that the founders had Gaelic and Norse origins. Genetic drift since the initial settlement has left modern Icelanders with allele frequencies that are distinctive, although still skewed toward those of their Norse founders. Scheib <jats:italic>et al.</jats:italic> sequenced ancient genomes from the Channel Islands of California, USA, and Ontario, Canada. The ancient Ontario population was similar to other ancient North Americans, as well as to modern Algonquian-speaking Native Americans. In contrast, the California individuals were more like groups that now live in Mexico and South America. It appears that a genetic split and population isolation likely occurred during the Ice Age, but the peoples remixed at a later date. </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="6392" page="1028" related-article-type="in-this-issue" vol="360" xlink:href="10.1126/science.aar2625">1028</jats:related-article> , p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6392" page="1024" related-article-type="in-this-issue" vol="360" xlink:href="10.1126/science.aar6851">1024</jats:related-article> ; see also p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6392" page="964" related-article-type="in-this-issue" vol="360" xlink:href="10.1126/science.aat7257">964</jats:related-article> </jats:p>

<jats:title>Founder effects in modern populations</jats:title> <jats:p> The genomes of ancient humans can reveal patterns of early human migration (see the Perspective by Achilli <jats:italic>et al.</jats:italic> ). Iceland has a genetically distinct population, despite relatively recent settlement (∼1100 years ago). Ebenesersdóttir <jats:italic>et al.</jats:italic> examined the genomes of ancient Icelandic people, dating to near the colonization of Iceland, and compared them with modernday Icelandic populations. The ancient DNA revealed that the founders had Gaelic and Norse origins. Genetic drift since the initial settlement has left modern Icelanders with allele frequencies that are distinctive, although still skewed toward those of their Norse founders. Scheib <jats:italic>et al.</jats:italic> sequenced ancient genomes from the Channel Islands of California, USA, and Ontario, Canada. The ancient Ontario population was similar to other ancient North Americans, as well as to modern Algonquian-speaking Native Americans. In contrast, the California individuals were more like groups that now live in Mexico and South America. It appears that a genetic split and population isolation likely occurred during the Ice Age, but the peoples remixed at a later date. </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="6392" page="1028" related-article-type="in-this-issue" vol="360" xlink:href="10.1126/science.aar2625">1028</jats:related-article> , p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6392" page="1024" related-article-type="in-this-issue" vol="360" xlink:href="10.1126/science.aar6851">1024</jats:related-article> ; see also p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6392" page="964" related-article-type="in-this-issue" vol="360" xlink:href="10.1126/science.aat7257">964</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>