Catálogo de publicaciones - revistas

<jats:p>Bayes' theorem plays an increasingly prominent role in statistical applications but remains controversial among statisticians.</jats:p>

<jats:p> The detection of a pocket of trapped particles may provide a hint to understanding the mechanism of planet formation. <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="6137" page="1199" related-article-type="in-this-issue" vol="340" xlink:href="10.1126/science.1236770"> van der Marel <jats:italic>et al.</jats:italic> </jats:related-article> ] </jats:named-content> </jats:p>

<jats:p>A retrospective carbon dating approach proves that there is substantial production of new neurons in the adult human brain throughout life.</jats:p>

<jats:p> A gene cluster that regulates limb development is controlled in two phases by regulatory elements that flank the cluster and operate independently. <jats:named-content content-type="related-content"> [Also see Research Article by <jats:ext-link xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="uri" xlink:href="http://www.sciencemag.org/content/340/6137/1234167.full"> Andrey <jats:italic>et al.</jats:italic> </jats:ext-link> ] </jats:named-content> </jats:p>

<jats:p>Epithelia are robust tissues that support the structure of embryos and organs and serve as effective barriers against pathogens. Epithelia also chemically separate different physiological environments. These vital functions require tight association between cells through the assembly of junctions that mechanically stabilize the tissue. Remarkably, epithelia are also dynamic and can display a fluid behavior. Cells continuously die or divide, thereby allowing functional tissue homeostasis. Epithelial cells can change shape or intercalate as tissues deform during morphogenesis. We review the mechanical basis of tissue robustness and fluidity, with an emphasis on the pivotal role of junction dynamics. Tissue fluidity emerges from local active stresses acting at cell interfaces and allows the maintenance of epithelial organization during morphogenesis and tissue renewal.</jats:p>

<jats:p>Recent examples have highlighted how stem cells have the capability to initiate morphogenesis in vitro; that is, to generate complex structures in culture that closely parallel their in vivo counterparts. Lgr5, the receptor for the Wnt-agonistic R-spondins, marks stem cells in multiple adult organs of mice and humans. In R-spondin–based three-dimensional cultures, these Lgr5 stem cells can grow into ever-expanding epithelial organoids that retain their original organ identity. Single Lgr5 stem cells derived from the intestine can be cultured to build epithelial structures that retain hallmarks of the in vivo epithelium. Here, we review the mechanisms that support this notable example of self-organization and discuss applications of this technology for stem cell research, disease modeling (e.g., for colorectal cancer and cystic fibrosis), and regenerative medicine.</jats:p>

<jats:title>A Comet in the Sun</jats:title> <jats:p> In 2011, comet Lovejoy plunged into the solar atmosphere and survived its flight through a region of the Sun that has never been visited by spacecraft. <jats:bold> Downs <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="6137" page="1196" related-article-type="in-this-issue" vol="340" xlink:href="10.1126/science.1236550">1196</jats:related-article> ) used spacecraft observations of this Sun-grazing comet, combined with advanced magnetohydrodynamic simulations, to constrain the magnetic field of the solar atmosphere—a quantity that has been very difficult to measure directly. </jats:p>

<jats:title>From Dust Grains to Planets</jats:title> <jats:p> Almost 900 extrasolar planets have been identified, but we still struggle to understand exactly how planets form. Using data from the Atacama Large Millimeter Array, <jats:bold> van der Marel <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="6137" page="1199" related-article-type="in-this-issue" vol="340" xlink:href="10.1126/science.1236770">1199</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="6137" page="1179" related-article-type="in-this-issue" vol="340" xlink:href="10.1126/science.1239404">Armitage</jats:related-article> </jats:bold> ) report a highly asymmetric distribution of millimeter-sized grains surrounding a young star. Modeling suggests that these particles—the material from which planets form—are being trapped within a protoplanetary disk by an anticyclonic vortex. Localized concentration of large grains within a protoplanetary disk is thought to be a step in planet formation. </jats:p>

<jats:title>Trapped and Coupled</jats:title> <jats:p> Trapped single atoms are ideal for storing and manipulating quantum information. <jats:bold> Thompson <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="6137" page="1202" related-article-type="in-this-issue" vol="340" xlink:href="10.1126/science.1237125">1202</jats:related-article> , published online 25 April; see the Perspective by <jats:bold> <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6137" page="1175" related-article-type="in-this-issue" vol="340" xlink:href="10.1126/science.1239500">Keller</jats:related-article> </jats:bold> ) were able to control single atoms interacting coherently with a field mode of a photonic crystal cavity. An optical tweezer was used to trap the single atom, which enabled positioning of the atom in close proximity to the photonic crystal waveguide, coupling the atom to the optical mode of the cavity. Such coupling should prove useful in quantum measurement, sensing, and information processing. </jats:p>