Catálogo de publicaciones - revistas

<jats:title>Structures of eukaryotic ribonuclease P</jats:title> <jats:p> Ribonuclease P (RNase P) is a ribozyme that processes transfer RNA (tRNA) precursors and is found in all three kingdoms of life. Now, Lan <jats:italic>et al.</jats:italic> report the structures of yeast RNase P (see the Perspective by Scott and Nagai). The aporibozyme structure reveals how the protein components stabilize the RNA and explains how the structural roles of bacterial RNA elements have been delegated to the protein components in RNase P of higher organisms during evolution. The structure of yeast RNase P in complex with its natural substrate, a tRNA precursor, demonstrates the structural basis for substrate recognition and provides insights into its catalytic mechanism. </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" related-article-type="in-this-issue" xlink:href="10.1126/science.aat6678">eaat6678</jats:related-article> ; see also p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6415" page="644" related-article-type="in-this-issue" vol="362" xlink:href="10.1126/science.aav4743">644</jats:related-article> </jats:p>

<jats:title>A framework for cognitive spaces</jats:title> <jats:p> Ever since Tolman's proposal of cognitive maps in the 1940s, the question of how spatial representations support flexible behavior has been a contentious topic. Bellmund <jats:italic>et al.</jats:italic> review and combine concepts from cognitive science and philosophy with findings from neurophysiology of spatial navigation in rodents to propose a framework for cognitive neuroscience. They argue that spatial-processing principles in the hippocampalentorhinal region provide a geometric code to map information domains of cognitive spaces for high-level cognition and discuss recent evidence for this proposal. </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" related-article-type="in-this-issue" xlink:href="10.1126/science.aat6766">eaat6766</jats:related-article> </jats:p>

<jats:p>I came to the United States in 2016—from Paris to Pittsburgh—in the aftermath of a horrific series of terrorist attacks in France that targeted everyone. As a clinician-scientist, I wanted to continue focusing my efforts on therapies to restore vision rather than constantly check the news. As a Jew, I wanted to live according to ethical principles nurtured by my identity in an open society that does not consider deviation from secularism as questionable. As a father, I wanted my children and grandchildren to grow within a humanistic perspective and at the same time to honor their dual heritage. In 2012, the very mild reaction to the killing of soldiers and Jews, especially of children in a Jewish school, in Toulouse, was saddening, and there was great uncertainty about how a society infected by anger, fear, and intolerance would evolve. Two weeks ago, the mass killing at a Pittsburgh synagogue proved what I knew but wanted to forget—that no place on Earth is “safe” from hatred. But regardless of where any one of us lives and works, we are faced with the same, immense challenge: The quest for facts, enlightenment, and care versus ignorance and hatred matters more than ever.</jats:p>

<jats:p>A roundup of weekly science policy and related news.</jats:p>

<jats:p>Kilogram and other units will be derived from fixed constants of nature.</jats:p>

<jats:p>Ancient DNA and protein help solve evolutionary riddle.</jats:p>

<jats:p>Trove of new samples reveals expansion of Clovis hunters and mysterious 9000-year-old population turnover.</jats:p>

<jats:p>Clerics declare measles and rubella vaccine made with pork components impure.</jats:p>

<jats:p>Nonhuman primates grow in research importance, but trend alarms animal activists.</jats:p>

<jats:p>Jellyfish almost killed Angel Yanagihara. Now, she is on a mission to save others from their fatal venom.</jats:p>