Catálogo de publicaciones - revistas

<jats:title>A little help from a friend</jats:title> <jats:p> The Hawaiian sea slug <jats:italic>Elysia rufescens</jats:italic> grazes on an alga called <jats:italic>Bryopsis</jats:italic> sp. The alga defends itself from predators using peptide toxins decorated with fatty acids, called kahalalides. Zan <jats:italic>et al.</jats:italic> wondered if a third party was involved in toxin production (see the Perspective by Mascuch and Kubanek). Within the alga, a species of bacterium with a very reduced genome was discovered to be a factory for the nonribosomal assembly of a family of kahalalides. The authors elucidated the pathways for generating this chemical diversity. It seems that the sea slug not only tolerates the toxins but, to protect itself from being eaten by fish, grazes on the alga to accumulate kahalalide. </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.aaw6732">eaaw6732</jats:related-article> ; see also p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6445" page="1034" related-article-type="in-this-issue" vol="364" xlink:href="10.1126/science.aax8964">1034</jats:related-article> </jats:p>

<jats:p> Kubelka <jats:italic>et al</jats:italic> . (Reports, 9 November 2018, p. 680) claim that climate change has disrupted patterns of nest predation in shorebirds. They report that predation rates have increased since the 1950s, especially in the Arctic. We describe methodological problems with their analyses and argue that there is no solid statistical support for their claims. </jats:p>

<jats:title> The dope on <jats:sc>l</jats:sc> -dopa metabolism </jats:title> <jats:p> The efficacy of <jats:sc>l</jats:sc> -dopa treatment for Parkinson's disease is hugely variable between individuals, depending on the composition of their microbiota. <jats:sc>l</jats:sc> -Dopa is decarboxylated into active dopamine, but if the gut microbiota metabolize <jats:sc>l</jats:sc> -dopa before it crosses the blood-brain barrier, medication is ineffective. Maini Rekdal <jats:italic>et al.</jats:italic> found that different species of bacterium are involved in <jats:sc>l</jats:sc> -dopa metabolism (see the Perspective by O'Neill). Tyrosine decarboxylase (TDC) from <jats:italic>Enterococcus faecalis</jats:italic> and dopamine dehydroxylase (Dadh) from <jats:italic>Eggerthella lenta</jats:italic> A2 sequentially metabolized <jats:sc>l</jats:sc> -dopa into <jats:italic>m</jats:italic> -tyramine. The microbial <jats:sc>l</jats:sc> -dopa decarboxylase can be inactivated by ( <jats:italic>S</jats:italic> )-α-fluoromethyltyrosine (AFMT), which indicates possibilities for developing combinations of Parkinson's drugs to circumvent microbial inactivation. </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.aau6323">eaau6323</jats:related-article> ; see also p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6445" page="1030" related-article-type="in-this-issue" vol="364" xlink:href="10.1126/science.aax8937">1030</jats:related-article> </jats:p>

<jats:title>Cassini's last look at Saturn's rings</jats:title> <jats:p> During the final stages of the Cassini mission, the spacecraft flew between the planet and its rings, providing a new view on this spectacular system (see the Perspective by Ida). Setting the scene, Spilker reviews the numerous discoveries made using Cassini during the 13 years it spent orbiting Saturn. Iess <jats:italic>et al.</jats:italic> measured the gravitational pull on Cassini, separating the contributions from the planet and the rings. This allowed them to determine the interior structure of Saturn and the mass of its rings. Buratti <jats:italic>et al.</jats:italic> present observations of five small moons located in and around the rings. The moons each have distinctive shapes and compositions, owing to accretion of ring material. Tiscareno <jats:italic>et al.</jats:italic> observed the rings directly at close range, finding complex features sculpted by the gravitational interactions between moons and ring particles. Together, these results show that Saturn's rings are substantially younger than the planet itself and constrain models of their origin. </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="6445" page="1046" related-article-type="in-this-issue" vol="364" xlink:href="10.1126/science.aat3760">1046</jats:related-article> , 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.aat2965">eaat2965</jats:related-article> , 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.aat2349">eaat2349</jats:related-article> , 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.aau1017">eaau1017</jats:related-article> ; see also p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6445" page="1028" related-article-type="in-this-issue" vol="364" xlink:href="10.1126/science.aaw3098">1028</jats:related-article> </jats:p>

<jats:p> Bulla <jats:italic>et al</jats:italic> . dispute our main conclusion that the global pattern of nest predation is disrupted in shorebirds. We disagree with Bulla <jats:italic>et al</jats:italic> .’s conclusions and contest the robustness of their outcomes. We reaffirm our results that provide clear evidence that nest predation has increased significantly in shorebirds, especially in the Arctic. </jats:p>