《科學》（20190531出版）一周論文導讀

翻譯 | 宗華

Science, 31 May 2019, Vol. 364, No. 6443

《科學》2019年5月31日，第6443期364卷

物理學Physics

Imaging the electronic Wigner crystal in one dimension

在一維中對電子維格納晶體進行成像

作者： Shapir, A. Hamo, S. Pecker, et al

鏈接：

https://science.sciencemag.org/content/364/6443/870

摘要：

尤金·維格納在80多年前預測的電子量子晶體，仍是最難以捉摸的物質狀態之一。

在本研究中，我們通過對一維維格納晶體在真實空間中的電荷密度成像，對其進行了直接觀察。

為了以最小的侵入性對碳納米管的多體電子密度成像，我們利用另一個納米管作為掃描電荷擾動。我們得到的一些一維電子的圖像符合強相互作用晶體的理論預測。

晶體的量子性質出現在觀察到的通過勢壘的集體隧穿過程中。這些實驗為小維格納晶體的形成提供了直接的證據，並為通過成像真實空間中的多體密度研究其他脆弱相互作用態開闢了道路。

Abstract

The quantum crystal of electrons, predicted more than 80 years ago by Eugene Wigner, remains one of the most elusive states of matter. In this study, we observed the one-dimensional Wigner crystal directly by imaging its charge density inreal space. To image, with minimal in vasiveness, the many-body electronic density of a carbon nanotube, we used another nanotube as a scanning-charge perturbation. The images we obtained of a few electrons confined in one dimension match the theoretical predictions for strongly interacting crystals. The quantum nature of the crystal emerges in the observed collective tunneling through a potential barrier. These experiments provide the direct evidence fort he formation of small Wigner crystals and open the way for studying other fragile interacting states by imaging their many-body density in real space.

Observation of parity-time symmetry breaking in a single-spin system

在單自旋系統中對宇稱—時間對稱性破缺的觀察

作者：Yang Wu, Wenquan Liu, Jianpei Geng, et al

鏈接：

https://science.sciencemag.org/content/364/6443/878

摘要：

控制單自旋系統的演化是量子計算和量子感測的關鍵。科學家利用具有奇異性質的宇稱—時間對稱哈密頓量理論，研究了量子系統的動力學。

儘管宇稱—時間對稱性已在經典系統中得以研究，但在單個量子系統中對它的觀測仍難以捉摸。

本文提出了一種將一般宇稱—時間對稱哈密頓量擴大為厄密頓量的方法。利用金剛石中單個氮空位中心，從未被破壞到被破壞的PTPT對稱區域，各種量子狀態的演化均得到觀測。

Abstract

Steering the evolution of single spin systems is crucial for quantum computing and quantum sensing. The dynamics of quantum systems has been theoretically investigated with parity-time–symmetric Hamiltonians exhibiting exotic properties. Although parity-time symmetry has been explored in classical systems, its observation ina single quantum system remains elusive. We developed a method to dilate a general parity-time–symmetric Hamiltonian into a Hermitian one. The quantum state evolutions ranging from regions of unbroken to broken PTPT symmetry have been observed with a single nitrogen-vacancy center in diamond. Owing to the universality of the dilation method, our result provides a route for further exploiting and understanding the exotic properties of parity-time symmetric Hamiltonian in quantum systems.

生理學Physiology

Insular cortex processes aversive somatosensory information and is crucial for threat learning

島葉皮層處理令人厭惡的軀體感覺信息，對威脅學習至關重要

作者：Emmanuelle Berret, Michael Kintscher, Shriya Palchaudhuri, et al

鏈接：

https://science.sciencemag.org/content/364/6443/eaaw0474

摘要：

了解威脅對生存至關重要。在威脅學習過程中，無害的感覺知覺如語調，與令人厭惡的刺激（如輕微的足部電擊）相結合時，會獲得情感上的意義。

杏仁核對威脅記憶的形成至關重要，但人們對於處理令人厭惡的軀體感覺信息的上游大腦區域一直知之甚少。

在小鼠中施加光遺傳學技術，我們發現足部電擊時後島葉的沉默可減少急性恐懼行為，並且損害1天的威脅記憶。

島葉皮質神經元對足電擊作出反應，在學習威脅時獲得對音調的反應，並投射出不同的杏仁核分裂來驅動急性恐懼和威脅記憶的形成。因此，後島葉向杏仁核傳遞令人厭惡的足電擊信息，對了解環境中的潛在危險至關重要。

Abstract

Learning about threats is essential for survival. During threat learning, an innocuous sensory percept such as a tone acquires an emotional meaning when paired with an aversive stimulus such as a mild foot shock. The amygdala is critical for threat memory formation, but little is known about upstream brain areas that process aversive somatosensory information. Using optogenetic techniques in mice, we found that silencing of the posterior insula during footshock reduced acute fear behavior and impaired 1-day threat memory. Insular cortex neurons respond to footshocks, acquire responses to tones during threat learning, and project to distinct amygdala divisions to drive acute fear versus threat memory formation. Thus, the posterior insula conveys aversive footshock information to the amygdala and is crucial for learning about potential dangers in the environment.

Oligogenic inheritance of a human heart disease involving a genetic modifier

一種人類心臟病的低基因遺傳涉及一種遺傳修飾因子

作者：Casey A. Gifford1,2, Sanjeev S. Ranade1,2, Ryan Samarakoon, et al

鏈接：

https://science.sciencemag.org/content/364/6443/865

摘要：

複雜的遺傳機制被認為是許多人類疾病的基礎，但這一模型的實驗驗證一直難以捉摸。

這裡，我們證明，人類心臟異常可以由罕見的、遺傳的雜合突變組合引起。一個核家系的全外顯子組測序顯示，從兒童起患有心肌病的3個後代遺傳了3種錯義突變的MKL2、MYH7和NKX2-5基因單核苷酸變異。

MYH7和MKL2變異繼承自受影響的無癥狀父親，罕見的NKX2-5變異（小等位基因頻率0.0012）則遺傳自未受影響的母親。

我們利用CRISPR-Cas9產生編碼同源變異的小鼠，發現這3種變異的複合雜合性能再現人類疾病的表型。

Abstract

Complex genetic mechanisms are thought to underlie many human diseases, yet experimental proof of this model has been elusive. Here, we show that a human cardiac anomaly can be caused by a combination of rare, inherited heterozygous mutations. Whole-exome sequencing of a nuclear family revealed that three offspring with childhood-onset cardiomyopathy had inherited three missense single-nucleotide variants in the MKL2, MYH7, and NKX2-5 genes. The MYH7 and MKL2 variants were inherited from the affected, a symptomatic father and the rare NKX2-5 variant (minor allele frequency, 0.0012) from the unaffected mother. We used CRISPR-Cas9 to generate mice encoding the orthologous variants and found that compound heterozygosity for all three variants recapitulated the human disease phenotype.

生態學Ecology

Transgenic Metarhizium rapidly kills mosquitoes in a malaria-endemic region of Burkina Faso

在布吉納法索瘧疾流行地區，轉基因綠僵菌能迅速殺死蚊蟲

作者：Brian Lovett, Etienne Bilgo, Souro Abel Millogo, et al

鏈接：

https://science.sciencemag.org/content/364/6443/894

摘要：

瘧疾控制工作需要實施管理殺蟲劑耐藥性的新技術。平沙綠僵菌為強效的昆蟲選擇性毒素提供了一種有效的蚊子特異性傳遞系統。

在瘧疾流行的布吉納法索Soumousso地區一個名為MosquitoSphere的受控、近似自然環境中開展的半現場試驗證實，一種昆蟲特異性毒素（雜交）的表達增加了真菌殺傷力以及抗殺蟲劑的蚊蟲從某個地方被清除的可能性。

此外，由於雜交表達平沙綠僵菌在極低的孢子劑量下有效，因此其藥效比未變性的綠僵菌持續時間更長。

針對蚊子的轉基因綠僵菌的應用可能會很快（取決於適當的註冊），同時其產品可與現有的化學控制策略協同集成，以避免對殺蟲劑產生抗藥性。

Abstract

Malaria control efforts require implementation of new technologies that manage insecticide resistance. Metarhizium pingshaense provides an effective, mosquito-specific delivery system for potent insect-selective toxins. A semifield trial in a Mosquito Sphere (a contained, near-natural environment) in Soumousso, a region of Burkina Faso where malaria is endemic, confirmed that the expression of aninsect-specific toxin (Hybrid) increased fungal lethality and the likelihood that insecticide-resistant mosquitoes would be eliminated from a site. Also, as Hybrid-expressing M. pingshaense is effective at very low spore doses, its efficacy lasted longer than that of the unmodified Metarhizium. Deployment of transgenic Metarhizium against mosquitoes could (subject to appropriate registration) be rapid, with products that could synergistically integrate with existing chemical control strategies to avert insecticide resistance.

The uncertain future of protected lands and waters

受保護土地和水域前途未卜

作者：Rachel E. Golden Kroner, Siyu Qin, Carly N. Cook, et al

鏈接：

https://science.sciencemag.org/content/364/6443/881

摘要：

保護區旨在永久保護生物多樣性，但有證據表明，廣泛的法律變化破壞了保護區的持久性和有效性。

我們記錄了這些法律變化——美國和亞馬遜國家的保護區降級、規模縮小及退化（PADDD）事件，並彙編了全球可用的數據。

美國和亞馬遜國家的政府分別實施了269項和440項PADDD事件。

1892~2018年，73個國家共實施了3749起 PADDD事件，使519857平方公里土地不再受到保護；另外減緩了針對165972平方公里保護區的規定；其中， 78%的事件是2000年以來實施的。

大多數PADDD活動（62%）與工業規模的資源開採和開發有關，這表明PADDD可能損害生物多樣性保護目標。

Abstract

Protected areas are intended to safeguard biodiversity in perpetuity, yet evidence suggests that widespread legal changes undermine protected area durability and efficacy. We documented these legal changes—protected area downgrading, downsizing, and degazettement (PADDD) events—in the United States and Amazonian countries and compiled available data globally. Governments of the United States and Amazonian countries enacted 269 and 440 PADDD events, respectively. Between1892 and 2018, 73 countries enacted 3749 PADDD events, removing 519,857 square kilometers from protection and tempering regulations in an additional 1,659,972 square kilometers; 78% of events were enacted since 2000. Most PADDD events(62%) are associated with industrial-scale resource extraction and development, suggesting that PADDD may compromise biodiversity conservation objectives.

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