《科学》（20190125出版）一周论文导读

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《科学》（20190125出版）一周论文导读

2019 年 1 月 26 日 科学网

翻译 | 唐一尘

Science, 25 JANUARY 2019, Vol 363, Issue 6425

《科学》2019年1月25日，第6425期363卷

生物学Biology

Metabolic asymmetry and the global diversity of marine predators

代谢不对称与海洋食肉动物的全球多样性

▲ 作者：John M. Grady、Brian S. Maitner、Ara S. Winter、Kristin Kaschne，et al

▲ 链接：

http://science.sciencemag.org/content/363/6425/eaat4220

▲ 摘要：

地球上大多数的生物多样性集中在热带附近，即越靠近赤道，生物多样性就越高，然而，对海洋哺乳动物和鸟类而言，其实际情况却与之南辕北辙。

研究人员编纂了一个含有998种海洋顶级捕食动物（包括鲸鱼、鲨鱼、其他鱼类、海鸟及爬行动物）的分布数据库，它揭示了温血（内温性）和冷血（变温性）捕食动物生物地理分布所存在的显著差异。

结果显示，在高纬度的寒冷水域中，海洋中的温血哺乳动物和鸟类颇为兴旺，它们能稳定地进食冷血猎物，后者因为温度低而变得呆滞缓慢。而在热带地区，诸如海豹、鲸鱼和企鹅等温血哺乳动物和鸟类几乎绝迹，只有海豚才真正能扎根于热带的温暖海水之中。

▲ Abstract

Species richness of marine mammals and birds is highest in cold, temperate seas—a conspicuous exception to the general latitudinal gradient of decreasing diversity from the tropics to the poles. We compiled a comprehensive dataset for 998 species of sharks, fish, reptiles, mammals, and birds to identify and quantify inverse latitudinal gradients in diversity, and derived a theory to explain these patterns. We found that richness, phylogenetic diversity, and abundance of marine predators diverge systematically with thermoregulatory strategy and water temperature, reflecting metabolic differences between endotherms and ectotherms that drive trophic and competitive interactions. Spatial patterns of foraging support theoretical predictions, with total prey consumption by mammals increasing by a factor of 80 from the equator to the poles after controlling for productivity.

A regulatory circuit conferring varied flowering response to cold in annual and perennial plants

一年生和多年生植物对寒冷的不同开花反应的调节回路

▲ 作者：Youbong Hyun、Coral Vincent、Vicky Tilmes、Sara Bergonzi、Christiane Kiefer，et al

▲ 链接：

http://science.sciencemag.org/content/363/6425/409

▲ 摘要：

植物的繁殖策略千差万别。“短命”的一年生植物在萌发后不久就大量开花，而寿命较长的多年生植物则会推迟和限制开花。研究人员使用CRISPR/Cas9和种间基因转移研究了一年生和多年生十字花科植物之间生殖模式的差异。

结果发现，多年生黄花亭荠在冬季寒冷条件下的开花依赖于花整合因子鳞状细胞启动子结合蛋白样15（SPL15），其活性在寒冷条件下仅局限于老枝。而在一年生植物中，这个调节系统是保守的，但冷诱导开花发生在幼芽中，当植物生存环境变暖时，不需要SPL15，而是通过光周期途径调节。

通过重建多年生植物的年响应，我们得出结论：一年生和多年生植物的生殖特征模式是通过依赖于不同开花途径的变异产生的。

▲ Abstract

The reproductive strategies of plants are highly variable. Short-lived annuals flower abundantly soon after germination, whereas longer-lived perennials postpone and spatially restrict flowering. We used CRISPR/Cas9 and interspecies gene transfer to understand divergence in reproductive patterns between annual and perennial crucifers. We show that in perennial Arabis alpina, flowering in response to winter cold depends on the floral integrator SQUAMOSA PROMOTER BINDING PROTEIN-LIKE 15 (SPL15), whose activity is limited to older shoots and branches during cold exposure. In annuals, this regulatory system is conserved, but cold-induced flowering occurs in young shoots, without requirement for SPL15, through the photoperiodic pathway when plants return to warm. By reconstructing the annual response in perennials, we conclude that characteristic patterns of reproduction in annuals and perennials are conferred through variation in dependency on distinct flowering pathways acting in parallel.

行为学Behavior

Fake news on Twitter during the 2016 U.S. presidential election

美国2016年大选期间推特假新闻呈高度集中化

▲ 作者：Nir Grinberg、Kenneth Joseph、Lisa Friedland、Briony Swire-Thompson、David Lazer

▲ 链接：

http://science.sciencemag.org/content/363/6425/374

▲ 摘要：

在2016年美国总统大选期间，假新闻的概念被人们关注，它所描述的是，社交媒体上对错误信息的分享已经快速植根于如今的时代精神。然而，这一现象的范围与规模一直难以被充分把握。

本研究通过分析超过1.6万名美国登记选民在2016年美国总统大选时如何在推特上与假新闻源互动，发现在所研究的推特用户中仅有约1%占了与假新闻内容接触总量的80%。此外，他们中有0.1%参与了所分享的假新闻中的81%。对大多数人而言，他们所接触的政治新闻来自基于事实的媒体机构。

研究人员表示，在所有组群中，人们所接触的绝大多数政治新闻仍然来自大众型的并非虚假的新闻来源；这一结果“让人放心”，因为它与假新闻比真实新闻在选举时有更多人参与的宣称相左。

▲ Abstract

The spread of fake news on social media became a public concern in the United States after the 2016 presidential election. We examined exposure to and sharing of fake news by registered voters on Twitter and found that engagement with fake news sources was extremely concentrated. Only 1% of individuals accounted for 80% of fake news source exposures, and 0.1% accounted for nearly 80% of fake news sources shared. Individuals most likely to engage with fake news sources were conservative leaning, older, and highly engaged with political news. A cluster of fake news sources shared overlapping audiences on the extreme right, but for people across the political spectrum, most political news exposure still came from mainstream media outlets.

地球科学Earth Sciences

The 2018 rift eruption and summit collapse of Kīlauea Volcano

2018年基拉韦厄火山喷发和顶峰崩塌

▲ 作者：C. A. Neal、S. R. Brantley、L. Antolik、J. L. Babb、M. Burgess, et al

▲ 链接：

http://science.sciencemag.org/content/363/6425/367

▲ 摘要：

2018年，基拉韦厄火山至少200年来下部东断裂带最大规模喷发和火山口崩塌。4月30日，Puuoo火山口崩塌后，岩浆肆虐。5月3日，勒兹火山爆发，裂缝扩大6.8公里。5月4日的一次地震（6.9级）产生了约5米的断层滑动。

熔岩以每秒超过100立方米的速度喷发，最终覆盖了35.5平方公里。峰顶岩浆系统部分流失，产生小规模爆炸和几乎每天的崩塌，释放的能量相当于4.7到5.4级地震。8月4日，火山活动迅速减少。

研究人员表示，仔细分析历史观察和实时监控基拉韦厄火山，能成功预测危险事件。

▲ Abstract

In 2018, Kīlauea Volcano experienced its largest lower East Rift Zone (LERZ) eruption and caldera collapse in at least 200 years. After collapse of the Puuoo vent on 30 April, magma propagated downrift. Eruptive fissures opened in the LERZ on 3 May, eventually extending ~6.8 kilometers. A 4 May earthquake [moment magnitude (Mw) 6.9] produced ~5 meters of fault slip. Lava erupted at rates exceeding 100 cubic meters per second, eventually covering 35.5 square kilometers. The summit magma system partially drained, producing minor explosions and near-daily collapses releasing energy equivalent to Mw 4.7 to 5.4 earthquakes. Activity declined rapidly on 4 August. Summit collapse and lava flow volume estimates are roughly equivalent—about 0.8 cubic kilometers. Careful historical observation and monitoring of Kīlauea enabled successful forecasting of hazardous events.

化学/材料学Chemistry/Materials science

Pharmaceutical diversification via palladium oxidative addition complexes

钯氧化加成络合物使药物多样化

▲ 作者：Mycah R. Uehling、Ryan P. King、Shane W. Krska、Tim Cernak、Stephen L. Buchwald

▲ 链接：

http://science.sciencemag.org/content/363/6425/405

▲ 摘要：

钯催化的交叉偶联反应改变了对材料、药物、化学探针和其他功能分子的化学空间探索。然而，高密度功能化基质的交叉耦合仍然是一个主要挑战。

本研究设计了一种替代方法，使用从药物或类药物芳基卤化物中提取的钯氧化加成络合物（OACs）的化学计量量作为底物。在大多数情况下，与类似的催化反应相比，使用OACs的交叉偶联反应能在更温和的条件下进行，并且取得了更高的成功率。

OACs表现出显著的稳定性，在环境条件下经过几个月的台面存储后，仍能保持其反应活性。研究人员还演示了OACs在各种实验中的效用。

▲ Abstract

Palladium-catalyzed cross-coupling reactions have transformed the exploration of chemical space in the search for materials, medicines, chemical probes, and other functional molecules. However, cross-coupling of densely functionalized substrates remains a major challenge. We devised an alternative approach using stoichiometric quantities of palladium oxidative addition complexes (OACs) derived from drugs or drug-like aryl halides as substrates. In most cases, cross-coupling reactions using OACs proceed under milder conditions and with higher success than the analogous catalytic reactions. OACs exhibit remarkable stability, maintaining their reactivity after months of benchtop storage under ambient conditions. We demonstrated the utility of OACs in a variety of experiments including automated nanomole-scale couplings between an OAC derived from rivaroxaban and hundreds of diverse nucleophiles, as well as the late-stage derivatization of the natural product k252a.

Design and control of gas diffusion process in a nanoporous soft crystal

纳米多孔软晶体气体扩散过程的设计与控制

▲ 作者：Cheng Gu、Nobuhiko Hosono、Jia-Jia Zheng、Yohei Sato、Shinpei Kusaka，et al

▲ 链接：

http://science.sciencemag.org/content/363/6425/387

▲ 摘要：

多孔材料中气体扩散过程的设计具有挑战性，因为收缩孔径是一个先决条件，而客体分子的通道流量是由纳米通道的灵活和动态运动调节的。

在此，研究人员提出了一种多孔配位聚合物（PCP）扩散调节系统的设计。在该系统中，框架结构内的触发器分子运动提供了动门功能，从而实现了高效的气体分离和储存。PCP表现出较强的温度响应吸附，被吸附分子在不同的入口温度下发生分化，促进了氧/氩和乙烯/乙烷的动力学气相分离。

此外，研究人员还演示了乙烯在环境条件下的持久物理封装，这是由于其在特殊纳米通道中的扩散受到了强烈阻碍。

▲ Abstract

Design of the gas-diffusion process in a porous material is challenging because a contracted pore aperture is a prerequisite, whereas the channel traffic of guest molecules is regulated by the flexible and dynamic motions of nanochannels. Here, we present the rational design of a diffusion-regulatory system in a porous coordination polymer (PCP) in which flip-flop molecular motions within the framework structure provide kinetic gate functions that enable efficient gas separation and storage. The PCP shows substantial temperature-responsive adsorption in which the adsorbate molecules are differentiated by each gate-admission temperature, facilitating kinetics-based gas separations of oxygen/argon and ethylene/ethane with high selectivities of ~350 and ~75, respectively. Additionally, we demonstrate the long-lasting physical encapsulation of ethylene at ambient conditions, owing to strongly impeded diffusion in distinctive nanochannels.