Catálogo de publicaciones - revistas

<jats:title>Optimizing flow in dammed rivers</jats:title> <jats:p> Hydropower dams radically alter river flow regimes, often with consequences for the functioning and productivity of the waters downstream. Where fisheries in large tropical river systems are affected, there can be knock-on effects on food security. For the Mekong River, Sabo <jats:italic>et al.</jats:italic> used a data-based time series modeling approach to estimate the features of the flow regime that optimize the fishery that is crucial to food security in Cambodia (see the Perspective by Poff and Olden). Fish futures can be maximized within a managed hydrologic system with careful prescription of flows. Such data-driven approaches can be used to link hydrology to ecology and food production and specify design principles that could help to deliver food security in other river 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="6368" page="eaao1053" related-article-type="in-this-issue" vol="358" xlink:href="10.1126/science.aao1053">eaao1053</jats:related-article> ; see also p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6368" page="1252" related-article-type="in-this-issue" vol="358" xlink:href="10.1126/science.aaq1422">1252</jats:related-article> </jats:p>

<jats:title>Computer or human?</jats:title> <jats:p> Proving that we are human is now part of many tasks that we do on the internet, such as creating an email account, voting in an online poll, or even downloading a scientific paper. One of the most popular tests is text-based CAPTCHA, where would-be users are asked to decipher letters that may be distorted, partially obscured, or shown against a busy background. This test is used because computers find it tricky, but (most) humans do not. George <jats:italic>et al.</jats:italic> developed a hierarchical model for computer vision that was able to solve CAPTCHAs with a high accuracy rate using comparatively little training data. The results suggest that moving away from text-based CAPTCHAs, as some online services have done, may be a good idea. </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="6368" page="eaag2612" related-article-type="in-this-issue" vol="358" xlink:href="10.1126/science.aag2612">eaag2612</jats:related-article> </jats:p>

<jats:p>Pyke and Waser claim that our virtual pollination ecology model makes unrealistic assumptions and fails to predict observed nectar concentrations of bat flowers and negative correlations between pollinator body size and sugar concentration. In their comment, crucial model features are misrepresented, misunderstood, or ignored. Sensitivity to the supply/demand ratio explains both the equilibrium concentrations and the selection for lower concentrations by larger pollinators.</jats:p>

<jats:p> Nachev <jats:italic>et al</jats:italic> . (Reports, 6 January 2017, p. 75) present dilute nectar in bat-pollinated plants as “paradoxical” because bats prefer concentrated nectar, but paradox disappears with realistic assumptions about nectar evolution. We argue that they make unrealistic assumptions about the cognitive abilities of bat pollinators, invoke Weber’s law inappropriately, and cannot predict observed nectar concentrations of bat flowers or negative correlations between pollinator body size and average concentration. </jats:p>

<jats:title>The peopling of Asia</jats:title> <jats:p> In recent years, there has been increasing focus on the paleoanthropology of Asia, particularly the migration patterns of early modern humans as they spread out of Africa. Bae <jats:italic>et al.</jats:italic> review the current state of the Late Pleistocene Asian human evolutionary record from archaeology, hominin paleontology, geochronology, genetics, and paleoclimatology. They evaluate single versus multiple dispersal models and southern versus the northern dispersal routes across the Asian continent. They also review behavioral and environmental variability and how these may have affected modern human dispersals and interactions with indigenous populations. </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="6368" page="eaai9067" related-article-type="in-this-issue" vol="358" xlink:href="10.1126/science.aai9067">eaai9067</jats:related-article> </jats:p>

<jats:p>As the rallying cry against sexual harassment and bullying in many fields, including academia, continues to grow, more and more victims are coming forward with their stories, reflecting how this damaging culture has been the norm across sectors for decades. Studies of women in academia report that more than half have experienced harassment. This behavior has remained obscured for many reasons: fear, resignation, and acceptance. The scientific community must recognize the difficult conversations that have started and embrace this watershed moment as an opportunity for rapid and essential cultural change.</jats:p>

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

<jats:p>Flexible plastic electronics can be wedded to brain tissue to monitor neural chatter.</jats:p>

<jats:p>Data could help satellitemakers avoid deadly microdebris.</jats:p>

<jats:p>Historic fishing ban gives scientists time to probe ecology as northern waters warm.</jats:p>