Catálogo de publicaciones - revistas

<jats:title>Using the past to inform the future</jats:title> <jats:p> The late Quaternary paleorecord, within the past ∼130,000 years, can help to inform present-day management of the Earth's ecosystems and biota under climate change. Fordham <jats:italic>et al.</jats:italic> review when and where rapid climate transitions can be found in the paleoclimate record. They show how such events in Earth's history can shape our understanding of the consequences of future global warming, including rates of biodiversity loss, changes in ecosystem structure and function, and degradation in the goods and services that these ecosystems provide to humanity. They also highlight how recent developments at the intersection of paleoecology, paleoclimatology, and macroecology can provide opportunities to anticipate and manage the responses of species and ecosystems to changing climates in the Anthropocene. </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.abc5654">eabc5654</jats:related-article> </jats:p>

<jats:title>To continue or to switch strategy?</jats:title> <jats:p> Successful behavior in an uncertain, changing, and open-ended environment critically relies on the ability to decide between continuing with the ongoing strategy or exploring new options. Neuroimaging studies have shown that the human medial prefrontal cortex (mPFC) is the part of the brain that primarily deals with this dilemma. However, the contribution of the different mPFC regions remains largely unknown. Domenech <jats:italic>et al.</jats:italic> recorded neuronal activity in six epileptic patients with depth electrodes in this brain area (see the Perspective by Steixner-Kumar and Gläscher). The ventral mPFC inferred the reliability of the ongoing action plan according to action outcomes. It proactively flagged outcomes either as learning signals to better exploit this plan or as potential triggers to explore new ones. The dorsal mPFC then evaluated action outcomes and generated an adaptive behavioral strategy. </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.abb0184">eabb0184</jats:related-article> ; see also p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6507" page="1056" related-article-type="in-this-issue" vol="369" xlink:href="10.1126/science.abd7258">1056</jats:related-article> </jats:p>

<jats:title>Synthetic excitatory synaptic organizer</jats:title> <jats:p> The human brain contains trillions of synapses within a vast network of neurons. Synapse remodeling is essential to ensure the efficient reception and integration of external stimuli and to store and retrieve information. Building and remodeling of synapses occurs throughout life under the control of synaptic organizer proteins. Errors in this process can lead to neuropsychiatric or neurological disorders. Suzuki <jats:italic>et al.</jats:italic> combined structural elements of natural synaptic organizers to develop an artificial version called CPTX, which has different binding properties (see the Perspective by Salinas). CPTX could act as a molecular bridge to reconnect neurons and restore excitatory synaptic function in animal models of cerebellar ataxia, familial Alzheimer's disease, and spinal cord injury. The findings illustrate how structure-guided approaches can help to repair neuronal circuits. </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.abb4853">eabb4853</jats:related-article> ; see also p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6507" page="1052" related-article-type="in-this-issue" vol="369" xlink:href="10.1126/science.abd4762">1052</jats:related-article> </jats:p>

<jats:title>Building niches for multiple microbes</jats:title> <jats:p> Microbial conversion of heterogeneous feedstocks such as lignocellulose into one or more desired products requires assembly of pathways to both break down the inputs and produce the outputs. Shahab <jats:italic>et al.</jats:italic> assembled a collection of microbes that occupy different spatial niches within a bioreactor and have different metabolic capabilities. In the simplest version of their setup, an aerobic fungus adeptly breaks down cellulose into short sugar chains, an oxygen-tolerant bacterium converts these to lactic acid, and an anaerobic bacterium uses the lactic acid to synthesize the short-chain fatty acid butyric acid. Additional microbes handle limitations in the intermediate stream or divert lactic acid to longer-chain fatty acids, which are potentially more valuable. The integrated production and use of lactic acid for biosynthetic reactions could ideally serve as a platform for biosynthesis using robust, heterogeneous microbial consortia. </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.abb1214">eabb1214</jats:related-article> </jats:p>

<jats:title>You can find your own way</jats:title> <jats:p> Migration of cells through tissues and embryos is often steered by gradients of attractive chemicals in a process called chemotaxis. Cells are best at navigating complex routes, for which they use “self-generated chemotaxis” and create their own attractant gradients. An example of this is when neutrophils migrate into tissues to attack infection. Using modeling and live-cell data, Tweedy <jats:italic>et al.</jats:italic> found that self-generated chemotaxis allows cells to obtain surprising amounts of information about their environment. Cells of the slime mold <jats:italic>Dictyostelium discoideum</jats:italic> and mouse pancreatic cancer–derived cells were able to use the diffusion of attractants to identify the best route through complex mazes, even when the correct path was long and twisted, without ever entering incorrect paths. </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.aay9792">eaay9792</jats:related-article> </jats:p>

<jats:p>The world needs to trust science if vaccines are to prove useful, particularly those being developed to combat coronavirus disease 2019 (COVID-19). That is what makes the recent appearance of highly visible “do-it-yourself” (DIY) vaccine research so morally troubling. It's an obstacle to securing this trust.</jats:p>

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

<jats:p>FDA's emergency move raises fears of rushed approval for other experimental medicines.</jats:p>