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<jats:p> A vascular system of microchannels delivers polymer-forming reagents that seal and repair large damaged regions. <jats:named-content content-type="related-content"> [Also see Report by <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6184" page="620" related-article-type="in-this-issue" vol="344" xlink:href="10.1126/science.1251135"> White <jats:italic>et al.</jats:italic> </jats:related-article> ] </jats:named-content> </jats:p>

<jats:p> People in wheat-cultivating areas of China are more individualistic and analytical than those in rice-cultivating areas. <jats:named-content content-type="related-content"> [Also see Research Article by <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6184" page="603" related-article-type="in-this-issue" vol="344" xlink:href="10.1126/science.1246850"> Talhelm <jats:italic>et al.</jats:italic> </jats:related-article> ] </jats:named-content> </jats:p>

<jats:p> Newly formed hippocampal neurons participate in the encoding of new memories in adult rodents, but too much neurogenesis may jeopardize memory retention. <jats:named-content content-type="related-content"> [Also see Research Article by <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6184" page="598" related-article-type="in-this-issue" vol="344" xlink:href="10.1126/science.1248903"> Akers <jats:italic>et al.</jats:italic> </jats:related-article> ] </jats:named-content> </jats:p>

<jats:title>Forget It!</jats:title> <jats:p> When examining the relationship between the production of new neurons in the hippocampus and memory, studies have generally first manipulated hippocampal neurogenesis and afterward investigated memory formation and found that new neurons help to encode new memories. However, when investigating how similar manipulations of neurogenesis impact established hippocampus-dependent memories, <jats:bold> Akers <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="6184" page="598" related-article-type="in-this-issue" vol="344" xlink:href="10.1126/science.1248903">598</jats:related-article> ; see the Perspective by <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6184" page="594" related-article-type="in-this-issue" vol="344" xlink:href="10.1126/science.1254236"> <jats:bold>Mongiat and Schinder</jats:bold> </jats:related-article> ) uncovered a role for neurogenesis in memory clearance. Thus, the continuous addition of new neurons both degrades existing information stored in hippocampal circuits and simultaneously provides substrates for new learning. </jats:p>

<jats:title>Individualism Rules?</jats:title><jats:p>On a diverse and large set of cognitive tests, subjects in East Asian countries are more inclined to display collectivist choices, whereas subjects in the United States are more inclined to score as individualists.<jats:bold>Talhelm<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="6184" page="603" related-article-type="in-this-issue" vol="344" xlink:href="10.1126/science.1246850">603</jats:related-article>; see the Perspective by<jats:bold><jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6184" page="593" related-article-type="in-this-issue" vol="344" xlink:href="10.1126/science.1253815">Henrich</jats:related-article></jats:bold>) suggest that one historical source of influence was societal patterns of farming rice versus wheat, based on three cognitive measures of individualism and collectivism in 1000 subjects from rice- and wheat-growing regions in China.</jats:p>

<jats:title>Under the Dome</jats:title> <jats:p> The superconducting transition temperature <jats:italic> T <jats:sub>c</jats:sub> </jats:italic> of copper oxides has a dome-shaped dependence on chemical doping. Whether there is a quantum critical point (QCP) beneath the dome, and whether it is related to the enigmatic pseudogap, has been heavily debated. Two papers address this question in two different families of Bi-based cuprates. In (Bi,Pb) <jats:sub>2</jats:sub> (Sr,La) <jats:sub>2</jats:sub> CuO <jats:sub>6+δ</jats:sub> , <jats:bold> He <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="6184" page="608" related-article-type="in-this-issue" vol="344" xlink:href="10.1126/science.1248221">608</jats:related-article> ) found that the Fermi surface (FS) undergoes a topological change as doping is increased, which points to the existence of a QCP at a doping close to the maximum in <jats:italic> T <jats:sub>c</jats:sub> </jats:italic> , seemingly uncorrelated with the pseudogap. <jats:bold> Fujita <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="6184" page="612" related-article-type="in-this-issue" vol="344" xlink:href="10.1126/science.1248783">612</jats:related-article> ) studied a range of dopings in Bi <jats:sub>2</jats:sub> Sr <jats:sub>2</jats:sub> CaCu <jats:sub>2</jats:sub> O <jats:sub>8+δ</jats:sub> to find an FS reconstruction simultaneous with the disappearance of both rotational and translational symmetry breaking, the latter of which has been associated with the pseudogap. These findings point to a concealed QCP. </jats:p>

<jats:title>Under the Dome</jats:title> <jats:p> The superconducting transition temperature <jats:italic> T <jats:sub>c</jats:sub> </jats:italic> of copper oxides has a dome-shaped dependence on chemical doping. Whether there is a quantum critical point (QCP) beneath the dome, and whether it is related to the enigmatic pseudogap, has been heavily debated. Two papers address this question in two different families of Bi-based cuprates. In (Bi,Pb) <jats:sub>2</jats:sub> (Sr,La) <jats:sub>2</jats:sub> CuO <jats:sub>6+δ</jats:sub> , <jats:bold> He <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="6184" page="608" related-article-type="in-this-issue" vol="344" xlink:href="10.1126/science.1248221">608</jats:related-article> ) found that the Fermi surface (FS) undergoes a topological change as doping is increased, which points to the existence of a QCP at a doping close to the maximum in <jats:italic> T <jats:sub>c</jats:sub> </jats:italic> , seemingly uncorrelated with the pseudogap. <jats:bold> Fujita <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="6184" page="612" related-article-type="in-this-issue" vol="344" xlink:href="10.1126/science.1248783">612</jats:related-article> ) studied a range of dopings in Bi <jats:sub>2</jats:sub> Sr <jats:sub>2</jats:sub> CaCu <jats:sub>2</jats:sub> O <jats:sub>8+δ</jats:sub> to find an FS reconstruction simultaneous with the disappearance of both rotational and translational symmetry breaking, the latter of which has been associated with the pseudogap. These findings point to a concealed QCP. </jats:p>

<jats:title>Upgrading Methane Sans Oxygen</jats:title> <jats:p> Direct routes to converting methane to higher hydrocarbons can allow natural gas to be used to provide chemical feedstocks. However, the reaction conditions needed to activate the strong C-H bond tend to overoxidize the products. <jats:bold> Guo <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="6184" page="616" related-article-type="in-this-issue" vol="344" xlink:href="10.1126/science.1253150">616</jats:related-article> ) report a high-temperature nonoxidative route that exposes methane to isolated iron sites on a silica catalyst. Methyl radicals were generated and coupled in the gas phase to form ethylene and aromatics along with hydrogen. The isolation of the active sites avoided surface reactions between the radicals that would deposit solid carbon. </jats:p>

<jats:title>Self-Healing Larger Wounds</jats:title> <jats:p> By loading a polymer with pockets of monomer, it is possible to heal small cracks in a sample through the polymerization of the monomer following the formation of a crack. However, large holes are much harder to repair. <jats:bold> White <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="6184" page="620" related-article-type="in-this-issue" vol="344" xlink:href="10.1126/science.1251135">620</jats:related-article> ; see the Perspective by <jats:bold> <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6184" page="591" related-article-type="in-this-issue" vol="344" xlink:href="10.1126/science.1254317">Zhao and Arruda</jats:related-article> </jats:bold> ) developed a vascular-like repair system involving a dual-stage strategy to self-heal epoxy thermosets. After injecting a damaged site with precursors, a gel with reversible cross-links rapidly formed, so the material stayed in place that then solidified further upon cross-linking. The approach successfully patched holes larger than 3 centimeters in diameter. </jats:p>

<jats:title>Nanowire Growth Observed</jats:title> <jats:p> In the hypothetical microcrucible growth mechanism for nanowires, a molten catalytic particle located in a pore on a substrate continually feeds the outward growth of the wire. To observe such a mechanism requires the ability to examine nanowire growth in situ. <jats:bold> Boston <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="6184" page="623" related-article-type="in-this-issue" vol="344" xlink:href="10.1126/science.1251594">623</jats:related-article> ) studied various stages of Y <jats:sub>2</jats:sub> BaCuO <jats:sub>5</jats:sub> nanowire growth using transmission electron microscopy and were able to observe a microcrucible growth mechanism directly. </jats:p>