Catálogo de publicaciones - revistas

<jats:title>Getting around the capacity crunch</jats:title> <jats:p> The growing appetite for an ever-faster Internet and enhanced long-haul communication requires the pumping of more light down optic fibers. However, light-induced nonlinearities limit how much light can be pumped into the fiber without compromising the signal. This limitation has led to the prospect of a “capacity crunch.” Temprana <jats:italic>et al.</jats:italic> eliminated the effects of nonlinearity by using digital back-propagation methods with mutually coherent laser pulses from a single frequency comb. </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="6242" page="1445" related-article-type="in-this-issue" vol="348" xlink:href="10.1126/science.aab1781">1445</jats:related-article> </jats:p>

<jats:title>A quantum twist on classical optics</jats:title> <jats:p> Interpreting recent experimental results of light interactions with matter shows that the classical Maxwell theory of light has intrinsic quantum spin Hall effect properties even in free space. Complex effects in condensed-matter systems can often find analogs in cleaner optical systems. Bliokh <jats:italic>et al.</jats:italic> argue that the optical systems exhibiting such complex phenomena should also be simpler (see the Perspective by Stone). Their theoretical study shows that free-space light has a nonzero topological spin Chern number and thus should have counterpropagating surface modes. Such modes are actually well known and can be described as evanescent modes of Maxwell equations. </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="6242" page="1448" related-article-type="in-this-issue" vol="348" xlink:href="10.1126/science.aaa9519">1448</jats:related-article> ; see also p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6242" page="1432" related-article-type="in-this-issue" vol="348" xlink:href="10.1126/science.aac4368">1432</jats:related-article> </jats:p>

<jats:title>Complex shapes from chemical lithography</jats:title> <jats:p> Lithographic printing of semi-conductors builds up complex patterns one layer at a time. The process involves multiple steps to mask, print, and etch each layer. Luo <jats:italic>et al.</jats:italic> tweaked the same process used to grow silicon nanowires to pattern them into complex three-dimensional (3D) shapes. Gold acted as a catalyst to grow and elongate silicon nanowires from the vapor phase. Varying the pressure of the growth process altered the rate of gold diffusion along the surface of the wire. Upon etching the wires, the non-uniform coating of gold acted as a lithographic mask. The authors were thus able to make complex-shaped silicon spicules with a series of ridges and notches by strictly chemical means. </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="6242" page="1451" related-article-type="in-this-issue" vol="348" xlink:href="10.1126/science.1257278">1451</jats:related-article> </jats:p>

<jats:title>Driving liquid deuterium into metal</jats:title> <jats:p> Quick and powerful compression can force materials to change their properties dramatically. Knudson <jats:italic>et al.</jats:italic> compressed liquid deuterium to extreme temperatures and pressures using high-energy magnetic pulses at the Sandia Z-machine (see the Perspective by Ackland). Deuterium began to reflect like a mirror during compression, as the electrical conductivity sharply increased. The observed conditions for metallization of deuterium and hydrogen help us to build theoretical models for the universe's most abundant element. This a our understanding of the internal layering of gas giant planets such as Jupiter and Saturn. </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="6242" page="1455" related-article-type="in-this-issue" vol="348" xlink:href="10.1126/science.aaa7471">1455</jats:related-article> ; see also p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6242" page="1429" related-article-type="in-this-issue" vol="348" xlink:href="10.1126/science.aac6626">1429</jats:related-article> </jats:p>

<jats:title>Some like it hot</jats:title> <jats:p> Coral reefs are threatened by increasing temperatures. Acute temperature increases stress and damage corals. However, more gradual temperature changes can result in adaptation and subsequent tolerance for higher temperatures. Dixon <jats:italic>et al.</jats:italic> show that the heat tolerance that currently exists across coral populations from different latitudes can be inherited. Thus, natural variation in temperature tolerance may facilitate rapid adaptation among corals as our climate warms. </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="6242" page="1460" related-article-type="in-this-issue" vol="348" xlink:href="10.1126/science.1261224">1460</jats:related-article> </jats:p>

<jats:title>Protection from too much light</jats:title> <jats:p> Photosynthetic organisms protect themselves from too much light using pigment photoswitches that absorb excess energy. Leverenz <jats:italic>et al.</jats:italic> analyzed the structure of an active, energy-dissipating form of the orange carotenoid protein (OCP) from a cyanobacterium. When activated by excess light, OCP moves its hydrophobic carotenoid pigment 12 Å within the protein to accommodate nonphotochemical quenching by the broader photosynthetic antenna complex. </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="6242" page="1463" related-article-type="in-this-issue" vol="348" xlink:href="10.1126/science.aaa7234">1463</jats:related-article> </jats:p>

<jats:title>Sourcing the smell of the seaside</jats:title> <jats:p> Marine phytoplankton plays a critical role in the global sulfur cycle. Algae, for instance, are the main source of the aromatic compound dimethylsulfide (DMS) released from the oceans into the atmosphere. Alcolombri <jats:italic>et al.</jats:italic> identified the lyase enzyme responsible for DMS production in the bloom-forming marine phytoplankton <jats:italic>Emiliania huxleyi</jats:italic> (see the Perspective by Johnston). The presence of this gene in other globally distributed phytoplankton and corals suggests that it may serve as a reliable indicator of DMS production across diverse phyla. Because DMS gets oxidized to sulfur aerosols, which act as cloud condensation nuclei, this enzyme is a key global biogeochemical catalyst. </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="6242" page="1466" related-article-type="in-this-issue" vol="348" xlink:href="10.1126/science.aab1586">1466</jats:related-article> ; see also p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6242" page="1430" related-article-type="in-this-issue" vol="348" xlink:href="10.1126/science.aac5661">1430</jats:related-article> </jats:p>

<jats:title>Walking back talk of the end of warming</jats:title> <jats:p> Previous analyses of global temperature trends during the first decade of the 21st century seemed to indicate that warming had stalled. This allowed critics of the idea of global warming to claim that concern about climate change was misplaced. Karl <jats:italic>et al.</jats:italic> now show that temperatures did not plateau as thought and that the supposed warming “hiatus” is just an artifact of earlier analyses. Warming has continued at a pace similar to that of the last half of the 20th century, and the slowdown was just an illusion. </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="6242" page="1469" related-article-type="in-this-issue" vol="348" xlink:href="10.1126/science.aaa5632">1469</jats:related-article> </jats:p>

<jats:title>Looming in on the threat-response circuit</jats:title> <jats:p> What are the neural elements that transmit threat-relevant inputs in the brain? Shang <jats:italic>et al.</jats:italic> systematically identified the key neuronal subtypes in the mouse superior colliculus underlying active avoidance and defensive-like behaviors. They found a pathway that responded to looming objects, linking input from the retina to the fear center in the brain. </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="6242" page="1472" related-article-type="in-this-issue" vol="348" xlink:href="10.1126/science.aaa8694">1472</jats:related-article> </jats:p>