Science, 21 OCT 2022, VOL 378, ISSUE 6617
《科学》2022年10月21日，第378卷，6617期
信息科学Information Science
Delocalized photonic deep learning on the internet’s edge
可用于互联网边缘设备的去局部化光子深度学习
▲ 作者：ALEXANDER SLUDDS, SAUMIL BANDYOPADHYAY, ZAIJUN CHEN et al.
▲ 链接：
https://www.science.org/doi/10.1126/science.abq8271
▲ 摘要：
由于电源、处理和内存的限制，先进的机器学习模型目前无法在智能传感器及无人机等边缘设备上运行。在此，我们介绍一种基于网络去局部化模拟处理的机器学习推理方法。
这种方法名为Netcast，基于云端“智能收发器”传输权重数据到边缘设备，使超高效光子推理成为可能。我们演示了图像识别在40 attojoules / multiply （小于1光子/ multiply）的超低光能下，具有98.8%(93%)的分类精度。
我们使用了86公里的部署光纤，波长复用超过3太赫兹的光带宽，在波士顿地区的现场试验中再现了这一性能。Netcast允许毫瓦级边缘设备具有最小的内存和处理能力，计算速度为高功率云计算机所保留的每秒万亿次浮点运算速度。
▲ Abstract：
Advanced machine learning models are currently impossible to run on edge devices such as smart sensors and unmanned aerial vehicles owing to constraints on power, processing, and memory. We introduce an approach to machine learning inference based on delocalized analog processing across networks. In this approach, named Netcast, cloud-based “smart transceivers” stream weight data to edge devices, enabling ultraefficient photonic inference. We demonstrate image recognition at ultralow optical energy of 40 attojoules per multiply (<1 photon per multiply) at 98.8% (93%) classification accuracy. We reproduce this performance in a Boston-area field trial over 86 kilometers of deployed optical fiber, wavelength multiplexed over 3 terahertz of optical bandwidth. Netcast allows milliwatt-class edge devices with minimal memory and processing to compute at teraFLOPS rates reserved for high-power (>100 watts) cloud computers.
物理学Physics
Miniaturized spectrometers with a tunable van der Waals junction
带有可调谐范德华结的微型光谱仪
▲ 作者：HOON HAHN YOON, HENRY A. FERNANDEZ, FEDOR NIGMATULIN et al.
▲ 链接：
https://www.science.org/doi/10.1126/science.add8544
▲ 摘要：
可以使用设备光谱响应和重建算法的组合获得入射光谱的小型化计算光谱仪，是芯片上和植入应用的必要条件。
使用单一探测器的高灵敏度光谱测量可以使此类光谱仪的描迹按比例缩小，同时实现接近台式系统的光谱分辨率。我们报道了一种基于单一范德华结的高性能计算光谱仪，该光谱仪具有电可调输运介导的光谱响应。
我们实现了高峰值波长精度（约0.36纳米），高光谱分辨率（约3纳米），宽操作带宽（从约405到845纳米），以及概念验证光谱成像。我们的方法提供了一条通向超微型化的道路，并为单探测器计算光谱仪提供了前所未有的精度、分辨率和操作带宽方面的性能。
▲ Abstract：
Miniaturized computational spectrometers, which can obtain incident spectra using a combination of device spectral responses and reconstruction algorithms, are essential for on-chip and implantable applications. Highly sensitive spectral measurement using a single detector allows the footprints of such spectrometers to be scaled down while achieving spectral resolution approaching that of benchtop systems. We report a high-performance computational spectrometer based on a single van der Waals junction with an electrically tunable transport-mediated spectral response. We achieve high peak wavelength accuracy (∼0.36 nanometers), high spectral resolution (∼3 nanometers), broad operation bandwidth (from ∼405 to 845 nanometers), and proof-of-concept spectral imaging. Our approach provides a route toward ultraminiaturization and offers unprecedented performance in accuracy, resolution, and operation bandwidth for single-detector computational spectrometers.
材料科学Materials Science
Highly flexible and superhydrophobic MOF nanosheet membrane for ultrafast alcohol-water separation
用于超快醇-水分离的高柔性超疏水MOF纳米片膜
▲ 作者：LI-HAO XU, SHEN-HUI LI, HENG MAOYAN LI et al.
▲ 链接：
https://www.science.org/doi/10.1126/science.abo5680
▲ 摘要：
高性能渗透汽化膜在工业分离应用中具有潜力，但克服渗透-选择性权衡是一个挑战。我们报告了一种在聚合物基质上具有偏好形结构的高柔性金属-有机框架纳米片（MOF-NS）膜用于醇-水分离的策略。
控制成长速度后，我们采用表面涂层方法有效地生产出柔性和无缺陷的超疏水MOF-NS膜。电子显微镜捕捉到了柔性MOF-NS的可逆变形和垂直层间通路。
同时，通过分子模拟证实了其结构，揭示了传递机制。MOF-NS的超快输运通道在40°C条件下，在乙醇-水渗透汽化过程中具有极高的通量和8.9的分离因子，可用于生物燃料回收。MOF-NS和聚二甲基硅氧烷在分离性能上具有协同作用。
▲ Abstract：
High-performance pervaporation membranes have potential in industrial separation applications, but overcoming the permeability-selectivity trade-off is a challenge. We report a strategy to create highly flexible metal-organic framework nanosheet (MOF-NS) membranes with a faveolate structure on polymer substrates for alcohol-water separation. The controlled growth followed by a surface-coating method effectively produced flexible and defect-free superhydrophobic MOF-NS membranes. The reversible deformation of the flexible MOF-NS and the vertical interlamellar pathways were captured with electron microscopy. Molecular simulations confirmed the structure and revealed transport mechanism. The ultrafast transport channels in MOF-NS exhibited an ultrahigh flux and a separation factor of 8.9 in the pervaporation of 5 weight % ethanol-water at 40°C, which can be used for biofuel recovery. MOF-NS and polydimethylsiloxane synergistically contribute to the separation performance.
地球科学Earth Science
Spillover benefits from the world’s largest fully protected MPA
全球最大的海洋保护地带来溢出效应
▲ 作者：SARAH MEDOFF, JOHN LYNHAM AND JENNIFER RAYNOR
▲ 链接：
https://www.science.org/doi/10.1126/science.abn0098
▲ 摘要：
以往的研究对海洋保护区（MPAs）为迁移物种提供庇护和渔业溢出效益的潜力提出了质疑，因为大多数海洋保护区相对于这些物种的地理范围较小。我们测试了世界上最大的完全受保护的MPA——帕帕哈瑙莫夸基亚国家海洋保护区，所产生溢出效应的证据。
利用独立渔业观察员收集的特定物种数据，我们研究了2016年保护区扩张前后，靠近和远离保护区的单个船只的捕捞率变化。我们发现了黄鳍金枪鱼和大眼金枪鱼的溢出效益的证据。
▲ Abstract：
Previous research has cast doubt on the potential for marine protected areas (MPAs) to provide refuge and fishery spillover benefits for migratory species as most MPAs are small relative to the geographic range of these species. We test for evidence of spillover benefits accruing from the world’s largest fully protected MPA, Papahānaumokuākea Marine National Monument. Using species-specific data collected by independent fishery observers, we examine changes in catch rates for individual vessels near to and far from the MPA before and after its expansion in 2016. We find evidence of spillover benefits for yellowfin (Thunnus albacares) and bigeye tuna (Thunnus obesus).
生物学Biology
Disease outbreaks select for mate choice and coat color in wolves
疾病爆发决定了狼的配偶选择和皮毛颜色
▲ 作者：SARAH CUBAYNES, ELLEN E. BRANDELL, DANIEL R. STAHLER et al.
▲ 链接：
https://www.science.org/doi/10.1126/science.abi8745
▲ 摘要：
我们对病原体的进化和新疾病株的出现了解很多，但对宿主耐药性以及它是如何向其他个体发出信号并随后保持下来的却知之甚少。在北美洲，出现黑毛狼的频率变化被假设为与犬瘟热病毒（CDV）的爆发有关。
我们使用来自北美狼种群的横断面数据来验证这一假设，这些数据在CDV流行率和使皮毛变黑的等位基因方面有所不同，还有来自黄石国家公园的纵向数据以及建模。我们发现，CDV爆发的频率产生波动选择，导致杂合子优势，反过来影响黑色等位基因的频率、最佳交配行为和整个大陆的黑狼分布情况。
▲ Abstract：
We know much about pathogen evolution and the emergence of new disease strains, but less about host resistance and how it is signaled to other individuals and subsequently maintained. The cline in frequency of black-coated wolves (Canis lupus) across North America is hypothesized to result from a relationship with canine distemper virus (CDV) outbreaks. We tested this hypothesis using cross-sectional data from wolf populations across North America that vary in the prevalence of CDV and the allele that makes coats black, longitudinal data from Yellowstone National Park, and modeling. We found that the frequency of CDV outbreaks generates fluctuating selection that results in heterozygote advantage that in turn affects the frequency of the black allele, optimal mating behavior, and black wolf cline across the continent.
Time-restricted feeding mitigates obesity through adipocyte thermogenesis
限时进食可通过脂肪细胞产热以缓解肥胖情况
▲ 作者：CHELSEA HEPLER, BENJAMIN J. WEIDEMANN, NATHAN J. WALDECKBILIANA MARCHEVA et al.
▲ 链接：
https://www.science.org/doi/10.1126/science.abl8007
▲ 摘要：
进食节奏与明暗循环的失调会导致周围昼夜节律时钟紊乱和肥胖。相反，只在活动时期进食可缓解代谢综合征，虽然其机制尚不明晰。
我们发现，通过消融锌指蛋白423（ZFP423），脂肪细胞产热的基因增强通过增加小鼠的无效肌酸循环，减轻了在不活跃期摄入高脂肪饮食引起的肥胖。
脂肪细胞肌酸代谢的昼夜节律控制是饮食诱导产热的时间基础，通过过度表达时钟激活因子大脑和肌肉arnt样蛋白-1（BMAL1）来增强脂肪细胞的昼夜节律，可以改善饮食诱导肥胖期间的代谢并发症。这些发现揭示了在限时进食时，节律性肌酸介导的产热是驱动代谢效益的基本机制。
▲ Abstract：
Misalignment of feeding rhythms with the light-dark cycle leads to disrupted peripheral circadian clocks and obesity. Conversely, restricting feeding to the active period mitigates metabolic syndrome through mechanisms that remain unknown. We found that genetic enhancement of adipocyte thermogenesis through ablation of the zinc finger protein 423 (ZFP423) attenuated obesity caused by consumption of a high-fat diet during the inactive (light) period by increasing futile creatine cycling in mice. Circadian control of adipocyte creatine metabolism underlies the timing of diet-induced thermogenesis, and enhancement of adipocyte circadian rhythms through overexpression of the clock activator brain and muscle Arnt-like protein-1 (BMAL1) ameliorated metabolic complications during diet-induced obesity. These findings uncover rhythmic creatine-mediated thermogenesis as an essential mechanism that drives metabolic benefits during time-restricted feeding.
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