Catálogo de publicaciones - revistas

<jats:p>Future experiments may tell us if quantum mechanics is an approximation to a deeper-level theory.</jats:p>

<jats:p>Interactive evolutionary algorithms are increasingly implemented in Web sites to respond to user preferences.</jats:p>

<jats:p>A novel class of materials called topological insulators allows spin physics to be probed without the need for magnetic fields.</jats:p>

<jats:title>Dissecting Dyslexia and Learning</jats:title> <jats:p> Difficulties in learning to read, despite reasonable effort and instruction, form the basis of dyslexia. <jats:bold>Gabrieli</jats:bold> (p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" page="280" related-article-type="in-this-issue" vol="325" xlink:href="10.1126/science.1171999">280</jats:related-article> ; see the cover) now reviews the latest research into the causes of dyslexia. Neuroimaging studies may give early notice of impending dyslexia, and it is hoped that early interventions may lessen the impact of dyslexia. Learning occurs in many settings. Humans uniquely use the formalized settings of schools and curriculum. Infants and children also do plenty of learning outside these settings, often intermingling social interactions. <jats:bold> Meltzoff <jats:italic>et al.</jats:italic> </jats:bold> (p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" page="284" related-article-type="in-this-issue" vol="325" xlink:href="10.1126/science.1175626">284</jats:related-article> ) survey the variety of learning contexts that people experience and discuss how recent advances in neuroscience and robotics are driving a new synthesis of learning. </jats:p>

<jats:title>Dissecting Dyslexia and Learning</jats:title> <jats:p> Difficulties in learning to read, despite reasonable effort and instruction, form the basis of dyslexia. <jats:bold>Gabrieli</jats:bold> (p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" page="280" related-article-type="in-this-issue" vol="325" xlink:href="10.1126/science.1171999">280</jats:related-article> ; see the cover) now reviews the latest research into the causes of dyslexia. Neuroimaging studies may give early notice of impending dyslexia, and it is hoped that early interventions may lessen the impact of dyslexia. Learning occurs in many settings. Humans uniquely use the formalized settings of schools and curriculum. Infants and children also do plenty of learning outside these settings, often intermingling social interactions. <jats:bold> Meltzoff <jats:italic>et al.</jats:italic> </jats:bold> (p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" page="284" related-article-type="in-this-issue" vol="325" xlink:href="10.1126/science.1175626">284</jats:related-article> ) survey the variety of learning contexts that people experience and discuss how recent advances in neuroscience and robotics are driving a new synthesis of learning. </jats:p>

<jats:p>Increased horse race speed over the past century can be attributed to the crouching posture and increased work done by jockeys.</jats:p>

<jats:title>Ecology of Diarrhea</jats:title> <jats:p> Rotavirus is an important cause of morbidity and mortality globally, and, although the infection takes a terrible toll on infant lives, its epidemiology is rather poorly known. New vaccines have become available and are being introduced in the United States prior to global rollout, but they may have some unexpected effects on disease dynamics. <jats:bold> Pitzer <jats:italic>et al.</jats:italic> </jats:bold> (p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" page="290" related-article-type="in-this-issue" vol="325" xlink:href="10.1126/science.1172330">290</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="5938" page="274" related-article-type="in-this-issue" vol="325" xlink:href="10.1126/science.1177475">Medley and Nokes</jats:related-article> </jats:bold> ) analyzed data and developed models describing the epidemiology of rotavirus before and during adoption of the vaccine. Ecological analysis showed that the birth rate predicted the timing of epidemics much better than climatic variables and that shifts in birth rates explained changes over the years. But as increasing numbers of infants are vaccinated, the pool of susceptible individuals in the population will be reduced, which will affect the annual waves of geographic spread of rotavirus. </jats:p>

<jats:title>Living on the Edge</jats:title> <jats:p> Topological insulators are a recently described state of matter in which the bulk material is an insulator but with a metallic surface state that is protected by the topology of the Fermi surface. <jats:bold> Roth <jats:italic>et al.</jats:italic> </jats:bold> (p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" page="294" related-article-type="in-this-issue" vol="325" xlink:href="10.1126/science.1174736">294</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="5938" page="278" related-article-type="in-this-issue" vol="325" xlink:href="10.1126/science.1177157">Büttiker</jats:related-article> </jats:bold> ) now show that the current flow on the surface takes place in edge states around the boundary of the sample. These are similar to the current transport in high-quality two-dimensional electron gases in high magnetic field, which confirms theoretical work on these materials. </jats:p>

<jats:title>A Multiple Photon Pileup</jats:title> <jats:p> The field of quantum optics began with the observation that two independent photons emitted from a thermal source tend to bunch together. The same is true for any number of bosons, but how do the statistics and correlations evolve experimentally as the number increases? <jats:bold> Aβmann <jats:italic>et al.</jats:italic> </jats:bold> (p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" page="297" related-article-type="in-this-issue" vol="325" xlink:href="10.1126/science.1174488">297</jats:related-article> ) have developed a streak-camera technique that can distinguish the photon number and measure the higher-order correlations between the photons at the detector. The results confirm the predicted “ <jats:italic>n</jats:italic> factorial” dependence, showing that the tendency to bunch gets stronger as the number of independent photons is increased. </jats:p>

<jats:title>Coupled Copper Surface States</jats:title> <jats:p> Periodic arrays of quantum dots can create new electronic states that arise from coupling of the states created by confinement. <jats:bold> Lobo-Checa <jats:italic>et al.</jats:italic> </jats:bold> (p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" page="300" related-article-type="in-this-issue" vol="325" xlink:href="10.1126/science.1175141">300</jats:related-article> ) show that the electronic surface-state of copper can be converted into a regular array of quantum dots. An organic overlayer that is created on the copper surface has pores 1.6 nanometers in diameter that trap the surface states. The coupling of these trapped states is revealed in photoemission experiments, in which a shallow dispersive electronic band is formed. </jats:p>