Catálogo de publicaciones - revistas

<jats:title>General relativity reveals pulsar beams</jats:title> <jats:p> Pulsars are rotating neutron stars that emit beams of radio waves along their magnetic poles, seen as regular pulses if the beam points toward Earth. Desvignes <jats:italic>et al.</jats:italic> monitored a pulsar for more than a decade, observing how its radio pulses vary. General relativity causes precession of the rotation axis, because of the influence of a binary companion. In 2005, two pulses per rotation were visible, one from each magnetic pole, but by 2018 one had precessed out of our line of sight and disappeared. Mapping the radio emission across the magnetic pole determines the beaming angle, the angular region in which a radio observer can detect a pulsar. </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="6457" page="1013" related-article-type="in-this-issue" vol="365" xlink:href="10.1126/science.aav7272">1013</jats:related-article> </jats:p>

<jats:title>Miniaturizing spectrometers</jats:title> <jats:p> Spectroscopy is a ubiquitous characterization tool spanning most scientific and many industrial disciplines. Most handheld spectrometers are based on tabletop optical components, which limits the scale to which these spectrometers can be shrunk. To address the desire for miniaturized spectrometers with a micrometer-scale (and smaller) footprint, Yang <jats:italic>et al.</jats:italic> developed such a microspectrometer based on single, compositionally engineered nanowire. This result is a practical step forward for the use of other light-sensitive nanomaterials for such ultra-miniaturized spectroscopy platforms. </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="6457" page="1017" related-article-type="in-this-issue" vol="365" xlink:href="10.1126/science.aax8814">1017</jats:related-article> </jats:p>

<jats:title>An optical contortionist</jats:title> <jats:p> The development of gauge fields is fundamental to our theoretical understanding of interactions in physical systems. There are two kinds of fields: Abelian, in which the measured effects on an observable parameter are commutative; and non-Abelian (noncommutative), where the sequence in which the field is applied matters. The latter are more difficult to realize in solid-state systems, but recent theoretical work has suggested that these could be synthesized optically. Yang <jats:italic>et al.</jats:italic> generated non-Abelian gauge fields by cascading multiple nonreciprocal optical elements and verified this accomplishment by the observed interference patterns in a Sagnac interferometer. Having a system that is tunable between Abelian and non-Abelian regimes will be important for studying complex topological states in photonic platforms. </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="6457" page="1021" related-article-type="in-this-issue" vol="365" xlink:href="10.1126/science.aay3183">1021</jats:related-article> </jats:p>

<jats:title>An antibody is not the antidote</jats:title> <jats:p> An HIV therapeutic that would give long-term remission without sustained antiretroviral therapy (ART) is a long-term goal. Byrareddy <jats:italic>et al.</jats:italic> [ <jats:italic>Science</jats:italic> <jats:bold>354</jats:bold> , 197 (2016)] reported that treating simian immunodeficiency virus (SIV)–positive macaques with an antibody against integrin α <jats:sub>4</jats:sub> β <jats:sub>7</jats:sub> during and after ART results in sustained virologic control after stopping all treatment. Three studies in this issue question the reproducibility of that result. Di Mascio <jats:italic>et al.</jats:italic> sequenced the virus used in the 2016 study and found that it was a variant with a stop codon in the <jats:italic>nef</jats:italic> gene rather than a wild-type virus. Abbink <jats:italic>et al.</jats:italic> used the same antibody for α <jats:sub>4</jats:sub> β <jats:sub>7</jats:sub> as before but tested control of a more commonly used pathogenic virus. Iwamato <jats:italic>et al.</jats:italic> used the same <jats:italic>nef</jats:italic> -stop virus as in the earlier paper but combined the antibody against the integrin with an antibody against the SIV envelope glycoprotein, which also blocks viral binding of the integrin. None of these three new studies found that treating with the antibody had any effect on virologic control after stopping ART treatment. </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="6457" page="1025" related-article-type="in-this-issue" vol="365" xlink:href="10.1126/science.aav6695">1025</jats:related-article> , p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6457" page="1029" related-article-type="in-this-issue" vol="365" xlink:href="10.1126/science.aaw8562">1029</jats:related-article> , p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6457" page="1033" related-article-type="in-this-issue" vol="365" xlink:href="10.1126/science.aaw7765">1033</jats:related-article> </jats:p>

<jats:title>An antibody is not the antidote</jats:title> <jats:p> An HIV therapeutic that would give long-term remission without sustained antiretroviral therapy (ART) is a long-term goal. Byrareddy <jats:italic>et al.</jats:italic> [ <jats:italic>Science</jats:italic> <jats:bold>354</jats:bold> , 197 (2016)] reported that treating simian immunodeficiency virus (SIV)–positive macaques with an antibody against integrin α <jats:sub>4</jats:sub> β <jats:sub>7</jats:sub> during and after ART results in sustained virologic control after stopping all treatment. Three studies in this issue question the reproducibility of that result. Di Mascio <jats:italic>et al.</jats:italic> sequenced the virus used in the 2016 study and found that it was a variant with a stop codon in the <jats:italic>nef</jats:italic> gene rather than a wild-type virus. Abbink <jats:italic>et al.</jats:italic> used the same antibody for α <jats:sub>4</jats:sub> β <jats:sub>7</jats:sub> as before but tested control of a more commonly used pathogenic virus. Iwamato <jats:italic>et al.</jats:italic> used the same <jats:italic>nef</jats:italic> -stop virus as in the earlier paper but combined the antibody against the integrin with an antibody against the SIV envelope glycoprotein, which also blocks viral binding of the integrin. None of these three new studies found that treating with the antibody had any effect on virologic control after stopping ART treatment. </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="6457" page="1025" related-article-type="in-this-issue" vol="365" xlink:href="10.1126/science.aav6695">1025</jats:related-article> , p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6457" page="1029" related-article-type="in-this-issue" vol="365" xlink:href="10.1126/science.aaw8562">1029</jats:related-article> , p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6457" page="1033" related-article-type="in-this-issue" vol="365" xlink:href="10.1126/science.aaw7765">1033</jats:related-article> </jats:p>

<jats:title>An antibody is not the antidote</jats:title> <jats:p> An HIV therapeutic that would give long-term remission without sustained antiretroviral therapy (ART) is a long-term goal. Byrareddy <jats:italic>et al.</jats:italic> [ <jats:italic>Science</jats:italic> <jats:bold>354</jats:bold> , 197 (2016)] reported that treating simian immunodeficiency virus (SIV)–positive macaques with an antibody against integrin α <jats:sub>4</jats:sub> β <jats:sub>7</jats:sub> during and after ART results in sustained virologic control after stopping all treatment. Three studies in this issue question the reproducibility of that result. Di Mascio <jats:italic>et al.</jats:italic> sequenced the virus used in the 2016 study and found that it was a variant with a stop codon in the <jats:italic>nef</jats:italic> gene rather than a wild-type virus. Abbink <jats:italic>et al.</jats:italic> used the same antibody for α <jats:sub>4</jats:sub> β <jats:sub>7</jats:sub> as before but tested control of a more commonly used pathogenic virus. Iwamato <jats:italic>et al.</jats:italic> used the same <jats:italic>nef</jats:italic> -stop virus as in the earlier paper but combined the antibody against the integrin with an antibody against the SIV envelope glycoprotein, which also blocks viral binding of the integrin. None of these three new studies found that treating with the antibody had any effect on virologic control after stopping ART treatment. </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="6457" page="1025" related-article-type="in-this-issue" vol="365" xlink:href="10.1126/science.aav6695">1025</jats:related-article> , p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6457" page="1029" related-article-type="in-this-issue" vol="365" xlink:href="10.1126/science.aaw8562">1029</jats:related-article> , p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6457" page="1033" related-article-type="in-this-issue" vol="365" xlink:href="10.1126/science.aaw7765">1033</jats:related-article> </jats:p>

<jats:title>Precisely folding nanographene</jats:title> <jats:p> Graphene nanostructures that would result from folding or rolling graphene monolayers or bilayers have been predicted to have a number of interesting electronic properties, but control over such folding processes has been limited. Chen <jats:italic>et al.</jats:italic> used a scanning tunneling microscope tip to fold and unfold graphene nanoislands etched on graphite surfaces at low temperatures (4 kelvin). The fold angle could be precisely controlled to create different twist angles in bilayer graphene and a tubelike edge in folded graphene. They also folded 5 ring–7 ring defects and explored this heterojunction with scanning tunneling spectroscopy. </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="6457" page="1036" related-article-type="in-this-issue" vol="365" xlink:href="10.1126/science.aax7864">1036</jats:related-article> </jats:p>

<jats:title>Ocean greening off Hawai'i</jats:title> <jats:p> From June to August 2018, the eruption of Kīlauea volcano triggered a diatom-dominated phytoplankton bloom. Wilson <jats:italic>et al.</jats:italic> set sail to sample the plume, deploying subsea gliders and using satellite monitoring to measure the dynamics of this rare event in the nutrient-poor Pacific (see the Perspective by Ducklow and Plank). They found subsurface chlorophyll maxima not visible by remote sensing, performed transcriptome and N isotope marker analysis, and measured nutrients, partitioning of biomass into different organisms, and primary production. Much of the data are corroborated by physical modeling of the ocean dynamics. The authors conclude that the plume was fed by the lava heating subsurface water and triggering upwelling of deepwater nutrients to the surface rather than by direct injection of micronutrients from lava. </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="6457" page="1040" related-article-type="in-this-issue" vol="365" xlink:href="10.1126/science.aax4767">1040</jats:related-article> ; see also p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6457" page="978" related-article-type="in-this-issue" vol="365" xlink:href="10.1126/science.aay8088">978</jats:related-article> </jats:p>

<jats:title>Stabilizing synthetic gene circuits</jats:title> <jats:p> Making synthetic gene circuits in bacteria is one thing, but making them stable under selective pressure with high mutation rates is another. Liao <jats:italic>et al.</jats:italic> addressed this problem with an ecological strategy in which they created three strains of bacteria, each of which could kill or be killed by one of the other strains (see the Perspective by Johnston and Collins). Once the first strain of bacteria hosting the engineered circuit underwent mutations that decreased function, the system could be “rebooted” by addition of another strain that killed the first but also contained the desired synthetic circuit, allowing its function to proceed unperturbed. This strategy provides a way to control synthetic ecosystems and maintain synthetic gene circuits without using traditional selection to maintain plasmids with antibiotics. </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="6457" page="1045" related-article-type="in-this-issue" vol="365" xlink:href="10.1126/science.aaw0542">1045</jats:related-article> ; see also p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6457" page="986" related-article-type="in-this-issue" vol="365" xlink:href="10.1126/science.aay3157">986</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>