Catálogo de publicaciones - revistas

<jats:title>Setting the tempo for development</jats:title> <jats:p> Many animals display similarities in their organization (body axis, organ systems, and so on). However, they can display vastly different life spans and thus must accommodate different developmental time scales. Two studies now compare human and mouse development (see the Perspective by Iwata and Vanderhaeghen). Matsuda <jats:italic>et al.</jats:italic> studied the mechanism by which the human segmentation clock displays an oscillation period of 5 to 6 hours, whereas the mouse period is 2 to 3 hours. They found that biochemical reactions, including protein degradation and delays in gene expression processes, were slower in human cells compared with their mouse counterparts. Rayon <jats:italic>et al.</jats:italic> looked at the developmental tempo of mouse and human embryonic stem cells as they differentiate to motor neurons in vitro. Neither the sensitivity of cells to signals nor the sequence of gene-regulatory elements could explain the differing pace of differentiation. Instead, a twofold increase in protein stability and cell cycle duration in human cells compared with mouse cells was correlated with the twofold slower rate of human differentiation. These studies show that global biochemical rates play a major role in setting the pace of development. </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="6510" page="1450" related-article-type="in-this-issue" vol="369" xlink:href="10.1126/science.aba7668">1450</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.aba7667">eaba7667</jats:related-article> ; see also p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6510" page="1431" related-article-type="in-this-issue" vol="369" xlink:href="10.1126/science.abe0953">1431</jats:related-article> </jats:p>

<jats:title>A mess of plastic</jats:title> <jats:p> It is not clear what strategies will be most effective in mitigating harm from the global problem of plastic pollution. Borrelle <jats:italic>et al.</jats:italic> and Lau <jats:italic>et al.</jats:italic> discuss possible solutions and their impacts. Both groups found that substantial reductions in plastic-waste generation can be made in the coming decades with immediate, concerted, and vigorous action, but even in the best case scenario, huge quantities of plastic will still accumulate in the environment. </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="6510" page="1515" related-article-type="in-this-issue" vol="369" xlink:href="10.1126/science.aba3656">1515</jats:related-article> , p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6510" page="1455" related-article-type="in-this-issue" vol="369" xlink:href="10.1126/science.aba9475">1455</jats:related-article> </jats:p>

<jats:title>Nature of the molecule-surface encounter</jats:title> <jats:p> Adsorption is an important initial step in all heterogeneous chemical processes. However, detailed adsorption dynamics are complex and challenging to follow experimentally. Using the fact that vibrationally excited carbon monoxide molecules can be trapped on the Au(111) surface with all degrees of freedom being equilibrated except the vibrational ones, Borodin <jats:italic>et al.</jats:italic> show that the vibrational relaxation time can serve as an internal clock to follow the microscopic pathways of adsorption and equilibration on the surface. On the basis of molecular beam experiments and theoretical modeling of this prototypical system, the authors reveal the intricate interplay between physisorption and chemisorption states. These observed characteristics are relevant to many other heterogeneous systems. </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="6510" page="1461" related-article-type="in-this-issue" vol="369" xlink:href="10.1126/science.abc9581">1461</jats:related-article> </jats:p>

<jats:title>Better relaxing lockdown together</jats:title> <jats:p> Even during a pandemic, all countries—even islands—are dependent in one way or another on their neighbors. Without coordinated relaxation of nonpharmaceutical interventions (NPIs) among the most closely connected countries, it is difficult to envisage maintaining control of infectious viruses such as severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Ruktanonchai <jats:italic>et al.</jats:italic> used mobility data from smartphones to estimate movements between administrative units across Europe before and after the implementation of NPIs for coronavirus disease 2019 (COVID-19). Modeling disease dynamics under alternative scenarios of countries releasing NPIs, in particular stay-at-home orders, showed that if countries do not coordinate their NPIs when they relax lockdown, resurgence of disease occurs sooner. Coordination of on-off NPIs would significantly increase their effectiveness at reducing transmission across Europe. </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="6510" page="1465" related-article-type="in-this-issue" vol="369" xlink:href="10.1126/science.abc5096">1465</jats:related-article> </jats:p>

<jats:title>How ribosomes are made</jats:title> <jats:p> The formation of eukaryotic ribosomes is a complex process that starts with transcription of a large precursor RNA that assembles into a large 90S preribosome, which matures to finally give the 40S small subunit of the ribosome. Cheng <jats:italic>et al.</jats:italic> and Du <jats:italic>et al.</jats:italic> give insight into this process, using cryo–electron microscopy to look at intermediates along the pathway. Together, these studies reveal how a cast of molecular players act to coordinate the compositional and structural changes that transform the 90S preribosome into a pre-40S subunit. </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="6510" page="1470" related-article-type="in-this-issue" vol="369" xlink:href="10.1126/science.abb4119">1470</jats:related-article> , p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6510" page="1477" related-article-type="in-this-issue" vol="369" xlink:href="10.1126/science.aba9690">1477</jats:related-article> </jats:p>

<jats:title>How ribosomes are made</jats:title> <jats:p> The formation of eukaryotic ribosomes is a complex process that starts with transcription of a large precursor RNA that assembles into a large 90S preribosome, which matures to finally give the 40S small subunit of the ribosome. Cheng <jats:italic>et al.</jats:italic> and Du <jats:italic>et al.</jats:italic> give insight into this process, using cryo–electron microscopy to look at intermediates along the pathway. Together, these studies reveal how a cast of molecular players act to coordinate the compositional and structural changes that transform the 90S preribosome into a pre-40S subunit. </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="6510" page="1470" related-article-type="in-this-issue" vol="369" xlink:href="10.1126/science.abb4119">1470</jats:related-article> , p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6510" page="1477" related-article-type="in-this-issue" vol="369" xlink:href="10.1126/science.aba9690">1477</jats:related-article> </jats:p>