Catálogo de publicaciones - revistas

<jats:title>Ancient reefs provided fishy refuges</jats:title> <jats:p> Climate fluctuations have occurred repeatedly in Earth's history, and so there is much to be learned from examining the responses of past systems. Pellessier <jats:italic>et al.</jats:italic> reconstructed paleoenvironments over the past 3 million years from sediment cores collected across coral reef systems to explore the impacts of past conditions on reef fish diversity. Coral reefs survived in the Indo-Australian regions during times of otherwise extensive habitat loss. These robust reefs can explain much of the diversity found in present-day reef fish species. </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="6187" page="1016" related-article-type="in-this-issue" vol="344" xlink:href="10.1126/science.1249853">1016</jats:related-article> </jats:p>

<jats:title>Making and breaking neuronal synapses</jats:title> <jats:p> As the brain develops, early synapse formation is exuberant and haphazard. But as development progresses, connections are refined into functional networks. In that process, many synapses get eliminated. Uesaka <jats:italic>et al.</jats:italic> now show that molecules already known for axon guidance are functional later on when they regulate the synaptic pruning needed to refine the circuits connected during axon guidance. </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="6187" page="1020" related-article-type="in-this-issue" vol="344" xlink:href="10.1126/science.1252514">1020</jats:related-article> </jats:p>

<jats:title>High-definition view of the synapse</jats:title> <jats:p> Individual neurons communicate with one another via their synapses, so to understand the nervous system, we need to understand in detail how the synapses are organized. Wilhelm <jats:italic>et al.</jats:italic> present a quantitative molecular-scale image of the “average” synapse populated with realistic renditions of each of the protein components that contribute to the inner workings of neurons. </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="6187" page="1023" related-article-type="in-this-issue" vol="344" xlink:href="10.1126/science.1252884">1023</jats:related-article> </jats:p>

<jats:title>Conservation vs. eradication</jats:title> <jats:p> What's an ecologist to do when an endangered bird lives in an invasive grass? Ecosystems are complicated networks, with one species relying on another, and managing one species in isolation may damage other members of a community. Lampert <jats:italic>et al.</jats:italic> (see the Perspective by Buckley and Han) looked at the conflict between eradicating a damaging invasive grass species and protecting an endangered bird species that uses the grass as its home. The most effective management and restoration approach focused not on eradicating the invasive grass as quickly as possible but on making changes slowly enough that the birds could adapt. This approach may prove useful in other situations in which active restoration conflicts with other conservation goals. </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="6187" page="1028" related-article-type="in-this-issue" vol="344" xlink:href="10.1126/science.1250763">1028</jats:related-article> ; see also p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6187" page="975" related-article-type="in-this-issue" vol="344" xlink:href="10.1126/science.1254662">975</jats:related-article> </jats:p>

<jats:title>Motors stirring within the living cell</jats:title> <jats:p> Cytoskeletal dynamics is key to cellular function. At very short time scales, thermal motions probably dominate, whereas on time scales from minutes to hours, motor-protein-12–based directed transport is dominant. But what about the times in between? Fakhri <jats:italic>et al.</jats:italic> tracked kinesin molecules labeled with carbon nanotubes and monitored their motion in living cells for milliseconds to hours. The kinesins motored along microtubule tracks, but sometimes moved more randomly as the tracks themselves were moved by active, larger-scale cell movements. This active “stirring” of the cytoplasm may play a role in nonspecific transport. </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="6187" page="1031" related-article-type="in-this-issue" vol="344" xlink:href="10.1126/science.1250170">1031</jats:related-article> </jats:p>

<jats:title>How to recruit membrane trafficking machinery</jats:title> <jats:p> PI4KIIIβ is a lipid kinase that underlies Golgi function and is enlisted in biological responses that require rapid delivery of membrane vesicles, such as during the extensive membrane remodeling that occurs at the end of cell division. Burke <jats:italic>et al.</jats:italic> determined the structure of PI4KIIIβ in a complex with the membrane trafficking GTPase Rab11a. The way in which the proteins interact gives PI4KIIIβ the ability to simultaneously recruit Rab11a and its effectors on specific membranes. </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="6187" page="1035" related-article-type="in-this-issue" vol="344" xlink:href="10.1126/science.1253397">1035</jats:related-article> </jats:p>

<jats:title>How bacteria manage to breathe on rust</jats:title> <jats:p> In the absence of oxygen, anaerobic bacteria turn to other chemical compounds during respiration. This can be helpful in detoxifying heavy-metal pollution. Flynn <jats:italic>et al.</jats:italic> (see the Perspective by Friedrich and Finster) found that alkaline conditions prevent a detoxifying bug— <jats:italic>Shewanella oneidensis</jats:italic> —from using enzymes to reduce rust-like minerals. Instead, the bacteria reduce elemental sulfur compounds, generating hydrogen sulfide that reduces the iron indirectly. This interplay between anoxic biogeochemical cycles may explain why some anaerobic bacteria contain the genetic machinery necessary to reduce multiple compounds besides oxygen. </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="6187" page="1039" related-article-type="in-this-issue" vol="344" xlink:href="10.1126/science.1252066">1039</jats:related-article> ; see also p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6187" page="974" related-article-type="in-this-issue" vol="344" xlink:href="10.1126/science.1255442">974</jats:related-article> </jats:p>

<jats:title>Transcription takes a pause to consider</jats:title> <jats:p> A short sequence in DNA causes RNA polymerase (RNAP) to pause at thousands of previously undocumented locations in the genome. Larson <jats:italic>et al.</jats:italic> mapped these pause sites at single-nucleotide resolution in vivo in actively growing bacteria. Transcriptional pausing can be critical for the regulation of gene expression, by allowing RNA folding events and in the recruitment of other transcription factors. </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="6187" page="1042" related-article-type="in-this-issue" vol="344" xlink:href="10.1126/science.1251871">1042</jats:related-article> </jats:p>

<jats:p>A weekly roundup of information on newly offered instrumentation, apparatus, and laboratory materials of potential interest to researchers.</jats:p>

<jats:p>On this week's show: The impact of Tiananmen Square on science, 25 years later and a roundup of stories from our daily news site.</jats:p>