编译 | 冯维维
Science, 17 APRIL 2020, Vol 368, Issue 6488
《科学》2020年4月17日，第368卷，6488期
生态学Ecology
Meeting fisheries, ecosystem function, and biodiversity goals in a human-dominated world
实现渔业、生态系统功能和生物多样性目标
▲ 作者：Joshua E. Cinner, Jessica Zamborain-Mason, David Mouillot
▲ 链接：
https://science.sciencemag.org/content/368/6488/307
▲ 摘要
全球范围内珊瑚礁的减少，需要针对性的管理方面的解决方案，以维持珊瑚礁和依赖珊瑚礁的人们的生计。然而，人们对不同珊瑚礁管理工具在实现多种社会和生态目标的作用知之甚少。
随着人类压力梯度的不同，实现渔业、生态功能和生物多样性综合目标的可能性是非线性的，在实施管理中发生相对较小的变化可能对是否能实现这些目标会产生重大影响。
重要的是，管理可以为大多数珊瑚礁的渔业和生态功能提供大量的保护效益，但不能实现生物多样性的目标，因为它们的状态已经退化，而且面临着人类的压力。
▲ Abstract
The worldwide decline of coral reefs necessitates targeting management solutions that can sustain reefs and the livelihoods of the people who depend on them. However, little is known about the context in which different reef management tools can help to achieve multiple social and ecological goals. Because of nonlinearities in the likelihood of achieving combined fisheries, ecological function, and biodiversity goals along a gradient of human pressure, relatively small changes in the context in which management is implemented could have substantial impacts on whether these goals are likely to be met. Critically, management can provide substantial conservation benefits to most reefs for fisheries and ecological function, but not biodiversity goals, given their degraded state and the levels of human pressure they face.
Large contribution from anthropogenic warming to an emerging North American megadrought
北美干旱由人为叠加自然因素驱动
▲ 作者：A. Park Williams, Edward R. Cook, Jason E. Smerdon, Ben Livneh, etc.
▲ 链接：
https://science.sciencemag.org/content/368/6488/314
▲ 摘要
21世纪，北美西南部持续的严重干旱让人们将其与中世纪的特大干旱相提并论，并对人为因素对气候变化的作用提出质疑。
作者使用水文模型和一棵拥有1200年历史的树木的新年轮重建夏季的土壤水分，以此证明2000年至2018年北美西南的干旱是自公元800年以来第二次最严重的持续19年的干旱，仅次于16世纪后期的特大干旱。
2000年至2018年的超级大略样的土壤湿度轨迹，是由人为原因造成的变暖导致的干旱叠加自然变异驱动的。
▲ Abstract
Severe and persistent 21st-century drought in southwestern North America (SWNA) motivates comparisons to medieval megadroughts and questions about the role of anthropogenic climate change. We use hydrological modeling and new 1200-year tree-ring reconstructions of summer soil moisture to demonstrate that the 2000–2018 SWNA drought was the second driest 19-year period since 800 CE, exceeded only by a late-1500s megadrought. The megadrought-like trajectory of 2000–2018 soil moisture was driven by natural variability superimposed on drying due to anthropogenic warming.
化学Chemistry
A dual light-driven palladium catalyst: Breaking the barriers in carbonylation reactions
照亮来回的路
▲ 作者：Gerardo M. Torres, Yi Liu, Bruce A. Arndtsen
▲ 链接：
https://science.sciencemag.org/content/368/6488/318
▲ 摘要
催化剂通过打破现有的化学键然后形成新的化学键来加速化学反应。
通常，有利于第一个过程的因素会搅乱第二个过程，从而限制了催化剂的通用性。作者发现，钯配合物的可见光激发可以促进碳-卤素键的断裂和形成。
该反应通过多种烷基或芳基溴化物和碘化物的羰基化反应而形成酸氯化物。这些产物反过来又能进一步反应形成酰胺和酯。
▲ Abstract
Catalysts accelerate chemical reactions by breaking existing bonds and then forming new ones. Often, the factors that favor the first process can muddle the second one, constraining a catalyst's generality. Torres et al. found that visible light excitation of a palladium complex can facilitate both the breaking and making of carbon-halogen bonds. The reaction specifically forms acid chlorides by carbonylation of a wide variety of alkyl or aryl bromides and iodides. These products in turn can react further to form amides and esters.
Balancing volumetric and gravimetric uptake in highly porous materials for clean energy
平衡用于清洁能源的材料的体积和重量
▲ 作者：Zhijie Chen, Penghao Li, Ryther Anderson, Xingjie Wang, Xuan Zhang, Lee Robison, Omar K. Farha
▲ 链接：
https://science.sciencemag.org/content/368/6488/297
▲ 摘要
在交通工具上储存甲烷和氢气的压力通常被限制在100巴（1巴=10万帕）以内，因为使用的是轻量容器，但随着吸收材料的使用，其储存量可以增加。
高效的存储和传输需要容量和重量的平衡。作者设计了一个三铝节点的金属有机框架和一个大型六齿芳香链接器，优化了这两个参数。
这种材料超过了美国能源部为甲烷设定的目标，其可输送氢的能力（按重量计）为14%。
▲ Abstract
The pressure for onboard storage of methane and hydrogen on vehicles is usually limited to 100 bar for the use of lightweight containers, but the amount stored can be increased with the use of absorbent materials. Efficient storage and delivery require a balance of volumetric and gravimetric storage. Chen et al. designed a metal-organic framework with trialuminum nodes and a large hexadentate aromatic linker that optimizes both parameters. This material surpassed the U.S. Department of Energy targets for methane and had a deliverable capacity of 14% by weight for hydrogen.
物理学Physics
Topological funneling of light
拓扑光漏斗
▲ 作者：Sebastian Weidemann, Mark Kremer, Tobias Helbig, Tobias Hofmann, etc.
▲ 链接：
https://science.sciencemag.org/content/368/6488/311
▲ 摘要
耗散是非厄米系统的一个普遍特征。但非厄米度并非不可避免的麻烦，它可以被精确地控制，因此可以用于复杂的应用，比如灵敏度更高的光学传感器。
作者通过裁减最近邻耦合的各向异性来实现一个非厄米光子晶格。界面的出现导致整个本征模态谱的完全崩溃，导致界面上所有模态的指数局部化。
因此，晶格内的任何光场，无论其形状和输入位置，都向这个界面运动。基于这种被称为“非厄米表皮效应”的拓扑现象，作者展示了一个高效的光漏斗。
▲ Abstract
Dissipation is a general feature of non-Hermitian systems. But rather than being an unavoidable nuisance, non-Hermiticity can be precisely controlled and hence used for sophisticated applications, such as optical sensors with enhanced sensitivity. In our work, we implement a non-Hermitian photonic mesh lattice by tailoring the anisotropy of the nearest-neighbor coupling. The appearance of an interface results in a complete collapse of the entire eigenmode spectrum, leading to an exponential localization of all modes at the interface. As a consequence, any light field within the lattice travels toward this interface, irrespective of its shape and input position. On the basis of this topological phenomenon, called the “non-Hermitian skin effect,” we demonstrate a highly efficient funnel for light.
生物学Biology
Temperature-dependent sex determination is mediated by pSTAT3 repression of Kdm6b
温度影响性别设定
▲ 作者：Ceri Weber, Yingjie Zhou, Jong Gwan Lee, Loren L. Looger, etc.
▲ 链接：
https://science.sciencemag.org/content/368/6488/303
▲ 摘要
在许多爬行动物中，性别是由孵化卵时的巢温决定的。温度调节一种称为Kdm6b的表观遗传修饰基因的表达，该基因负责睾丸的发育。
然而，这一因子的温度和性别特异性表达之间的分子联系以前是未知的。
作者发现了温度与Kdm6b的关键调控因子激活之间的联系，该调控因子被称为信号转换器和转录激活因子3 （STAT3）。
在温度更高的生产雌性的Ca2+流入后，STAT3会磷酸化，让Kdm6b转录沉默，从而抑制睾丸发育。
▲ Abstract
In many reptiles, sex is determined by nest temperature during egg incubation. Temperature regulates the expression of an epigenetic modifier gene called Kdm6b, which is responsible for testis development. However, the molecular connection between temperature and sex-specific expression of this factor was previously unknown. Weber et al. have identified a link between temperature and the activation of a key regulator of Kdm6b called signal transducer and activator of transcription 3 (STAT3). After an influx of Ca2+ at the warmer, female-producing temperature, STAT3 is phosphorylated and silences Kdm6b transcription to repress testis development.
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