Catálogo de publicaciones - revistas

<jats:title>Digging for water</jats:title> <jats:p> Water is scarce in dryland ecosystems. Some larger animals in these regions dig wells that may provide water to other species. This behavior may have been common among megafauna that are now extinct, especially in North and South America, where megafaunal extinctions were the most severe. Lundgren <jats:italic>et al.</jats:italic> tested whether feral equids (horses and donkeys) reintroduced to desert regions in the North American southwest dig wells that provide ecosystem-level benefits. They found that equid-dug wells increased water availability, were used by a large number of species, and decreased distance between water sources. Abandoned wells also led to increased germination in key riparian tree species. Such equid-dug wells improve water availability, perhaps replacing a lost megafaunal function. </jats:p> <jats:p> <jats:italic>Science</jats:italic> , this issue p. <jats:related-article issue="6541" page="491" related-article-type="in-this-issue" vol="372">491</jats:related-article> </jats:p>

<jats:title>An optically active spiral</jats:title> <jats:p> The material cupric oxide exhibits magnetoelectric coupling, meaning that its magnetic properties can be controlled by electric fields. In its spin spiral phase, cupric oxide has a spiral magnetic ordering that can be right- or left-handed. Masuda <jats:italic>et al.</jats:italic> used electric fields to create purely left- or right-handed samples and then studied their optical activity. The samples exhibited natural optical activity, which the researchers were then able to control with electric fields. </jats:p> <jats:p> <jats:italic>Science</jats:italic> , this issue p. <jats:related-article issue="6541" page="496" related-article-type="in-this-issue" vol="372">496</jats:related-article> </jats:p>

<jats:title>Gated ion flow in graphene oxide membranes</jats:title> <jats:p> Cells are adept at fast, gated ion flow through tailored channels, which is key to many biological processes. Xue <jats:italic>et al.</jats:italic> developed ion transistors from reduced graphene oxide membranes and observed a field-enhanced diffusivity of the ions (see the Perspective by Hinds). By applying electrical gating, the average surface potential on the graphene layer could be controlled, thus altering the energy barrier for ion intercalation into the channel and leading to very high diffusion rates. The authors observed selective ion transport two orders of magnitude faster than the ion diffusion in bulk water. </jats:p> <jats:p> <jats:italic>Science</jats:italic> , this issue p. <jats:related-article issue="6541" page="501" related-article-type="in-this-issue" vol="372">501</jats:related-article> ; see also p. <jats:related-article issue="6541" page="459" related-article-type="in-this-issue" vol="372">459</jats:related-article> </jats:p>

<jats:title>Varying the stop lights</jats:title> <jats:p> Traffic light protocols can help to mitigate induced earthquakes from unconventional oil production. However, they are not geographically tuned to account for how shaking may actually translate to structural damage. Schultz <jats:italic>et al.</jats:italic> incorporated damage tolerance into a traffic light protocol for the Eagle Ford shale play. They found that shut-off may be necessary more quickly in populated regions, whereas sparsely populated areas of the play can take up to a magnitude 5 earthquake without issue. This risk-based strategy provides a more nuanced approach to regulating induced seismicity. </jats:p> <jats:p> <jats:italic>Science</jats:italic> , this issue p. <jats:related-article issue="6541" page="504" related-article-type="in-this-issue" vol="372">504</jats:related-article> </jats:p>

<jats:title>Move aside, aluminum</jats:title> <jats:p> Some of the most promising schemes for quantum information processing involve superconductors. In addition to the established superconducting qubits, topological qubits may one day be realized in semiconductor-superconductor heterostructures. The superconductor most widely used in this context is aluminum, in which processes that cause decoherence are suppressed. Pendharkar <jats:italic>et al.</jats:italic> go beyond this paradigm to show that superconducting tin can be used in place of aluminum (see the Perspective by Fatemi and Devoret). The authors grew nanowires of indium antimonide, which is a semiconductor, and coated them with a thin layer of tin without using cumbersome epitaxial growth techniques. This process creates a well-defined, “hard” superconducting gap in the nanowires, which is a prerequisite for using them as the basis for a potential topological qubit. </jats:p> <jats:p> <jats:italic>Science</jats:italic> , this issue p. <jats:related-article issue="6541" page="508" related-article-type="in-this-issue" vol="372">508</jats:related-article> ; see also p. <jats:related-article issue="6541" page="464" related-article-type="in-this-issue" vol="372">464</jats:related-article> </jats:p>

<jats:title>Biosynthesis and replication, from A to Z</jats:title> <jats:p> Four nucleobases. adenine (A), cytosine (C), guanine (G), and thymine (T), are usually thought to be invariable in DNA. In bacterial viruses, however, each of the DNA bases have variations that help them to escape degradation by bacterial restriction enzymes. In the genome of cyanophage S-2L, A is completely replaced by diaminopurine (Z), which forms three hydrogen bonds with T and thus creates non–Watson-Crick base pairing in the DNA of this virus (see the Perspective by Grome and Isaacs). Zhou <jats:italic>et al.</jats:italic> and Sleiman <jats:italic>et al.</jats:italic> determined the biochemical pathway that produces Z, which revealed more Z genomes in viruses hosted in bacteria distributed widely in the environment and phylogeny. Pezo <jats:italic>et al.</jats:italic> identified a DNA polymerase that incorporates Z into DNA while rejecting A. These findings enrich our understanding of biodiversity and expand the genetic palette for synthetic biology. </jats:p> <jats:p> <jats:italic>Science</jats:italic> , this issue p. <jats:related-article issue="6541" page="512" related-article-type="in-this-issue" vol="372">512</jats:related-article> , <jats:related-article issue="6541" page="516" related-article-type="in-this-issue" vol="372">516</jats:related-article> , <jats:related-article issue="6541" page="520" related-article-type="in-this-issue" vol="372">520</jats:related-article> ; see also p. <jats:related-article issue="6541" page="460" related-article-type="in-this-issue" vol="372">460</jats:related-article> </jats:p>

<jats:title>Biosynthesis and replication, from A to Z</jats:title> <jats:p> Four nucleobases. adenine (A), cytosine (C), guanine (G), and thymine (T), are usually thought to be invariable in DNA. In bacterial viruses, however, each of the DNA bases have variations that help them to escape degradation by bacterial restriction enzymes. In the genome of cyanophage S-2L, A is completely replaced by diaminopurine (Z), which forms three hydrogen bonds with T and thus creates non–Watson-Crick base pairing in the DNA of this virus (see the Perspective by Grome and Isaacs). Zhou <jats:italic>et al.</jats:italic> and Sleiman <jats:italic>et al.</jats:italic> determined the biochemical pathway that produces Z, which revealed more Z genomes in viruses hosted in bacteria distributed widely in the environment and phylogeny. Pezo <jats:italic>et al.</jats:italic> identified a DNA polymerase that incorporates Z into DNA while rejecting A. These findings enrich our understanding of biodiversity and expand the genetic palette for synthetic biology. </jats:p> <jats:p> <jats:italic>Science</jats:italic> , this issue p. <jats:related-article issue="6541" page="512" related-article-type="in-this-issue" vol="372">512</jats:related-article> , <jats:related-article issue="6541" page="516" related-article-type="in-this-issue" vol="372">516</jats:related-article> , <jats:related-article issue="6541" page="520" related-article-type="in-this-issue" vol="372">520</jats:related-article> ; see also p. <jats:related-article issue="6541" page="460" related-article-type="in-this-issue" vol="372">460</jats:related-article> </jats:p>

<jats:title>Biosynthesis and replication, from A to Z</jats:title> <jats:p> Four nucleobases. adenine (A), cytosine (C), guanine (G), and thymine (T), are usually thought to be invariable in DNA. In bacterial viruses, however, each of the DNA bases have variations that help them to escape degradation by bacterial restriction enzymes. In the genome of cyanophage S-2L, A is completely replaced by diaminopurine (Z), which forms three hydrogen bonds with T and thus creates non–Watson-Crick base pairing in the DNA of this virus (see the Perspective by Grome and Isaacs). Zhou <jats:italic>et al.</jats:italic> and Sleiman <jats:italic>et al.</jats:italic> determined the biochemical pathway that produces Z, which revealed more Z genomes in viruses hosted in bacteria distributed widely in the environment and phylogeny. Pezo <jats:italic>et al.</jats:italic> identified a DNA polymerase that incorporates Z into DNA while rejecting A. These findings enrich our understanding of biodiversity and expand the genetic palette for synthetic biology. </jats:p> <jats:p> <jats:italic>Science</jats:italic> , this issue p. <jats:related-article issue="6541" page="512" related-article-type="in-this-issue" vol="372">512</jats:related-article> , <jats:related-article issue="6541" page="516" related-article-type="in-this-issue" vol="372">516</jats:related-article> , <jats:related-article issue="6541" page="520" related-article-type="in-this-issue" vol="372">520</jats:related-article> ; see also p. <jats:related-article issue="6541" page="460" related-article-type="in-this-issue" vol="372">460</jats:related-article> </jats:p>

<jats:title>How an early variant got ahead</jats:title> <jats:p> Throughout the COVID-19 pandemic, epidemiologists have monitored the evolution of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) with particular focus on the spike protein. An early variant with an aspartic acid (D) to glycine (G) mutation at position 614, D614G, rapidly became dominant and is maintained in current variants of concern. Zhang <jats:italic>et al.</jats:italic> investigated the structural basis for the increased spread of this variant, which does so even though it binds less tightly to the host receptor (see the Perspective by Choe and Farzan). Structural and biochemical studies on a full-length G614 spike trimer showed that there are interactions not present in D614 that prevent premature loss of the S1 subunit that binds angiotensin-converting enzyme 2. This stabilization effectively increases the number of spikes that can facilitate infection. </jats:p> <jats:p> <jats:italic>Science</jats:italic> , this issue p. <jats:related-article issue="6541" page="525" related-article-type="in-this-issue" vol="372">525</jats:related-article> ; see also p. <jats:related-article issue="6541" page="466" related-article-type="in-this-issue" vol="372">466</jats:related-article> </jats:p>