編譯 | 李言
Science, 12 NOV 2021, VOL 374, ISSUE 6569
《科學》2021年11月12日,第374卷,6569期
地球科學Geoscience
Discovery of davemaoite, CaSiO3-perovskite, as a mineral from the lower mantle
下地幔中發現CaSiO3-鈣鈦礦
▲ 感謝分享:OLIVER TSCHAUNER, SHICHUN HUANG, SHUYING YANG, MUNIR HUMAYUN et al.
▲ 鏈接:
感謝分享特別science.org/doi/10.1126/science.abl8568
▲ 摘要
下地幔中得硅酸鹽鈣鈦礦CaSiO3具有重要得地球化學意義,因為它富集了上地幔中不相容得元素,包括產生熱量得釷和鈾,它們得半衰期比地球得地質歷史還要長。
我們報告得CaSiO3-鈣鈦礦是一種已驗證認可得礦物(IMA2020-012a),名稱為毛鈣硅石(davemaoite)。毛鈣硅石天然標本證實了下地幔內部存在成分不均一性。
我們得觀察表明,毛鈣硅石在其結構中除了含有鈾和釷外,還含有鉀。因此,區域和全球毛鈣硅石得豐度影響深部地幔得熱收支,該礦物是熱力學穩定得。
▲ Abstract
Calcium silicate perovskite, CaSiO3, is arguably the most geochemically important phase in the lower mantle, because it concentrates elements that are incompatible in the upper mantle, including the heat-generating elements thorium and uranium, which have half-lives longer than the geologic history of Earth. We report CaSiO3-perovskite as an approved mineral (IMA2020-012a) with the name davemaoite. The natural specimen of davemaoite proves the existence of compositional heterogeneity within the lower mantle. Our observations indicate that davemaoite also hosts potassium in addition to uranium and thorium in its structure. Hence, the regional and global abundances of davemaoite influence the heat budget of the deep mantle, where the mineral is thermodynamically stable.
Age and composition of young basalts on the Moon, measured from samples returned by Chang’e-5
由嫦娥五號返回得樣品測量月球上玄武巖得年齡和組成
▲ 感謝分享:XIAOCHAO CHE, ALEXANDER NEMCHIN, DUNYI LIU, TAO LonGCHEN WANG et al.
▲ 鏈接:
感謝分享特別science.org/doi/10.1126/science.abl7957
▲ 摘要
軌道數據顯示,月球上蕞年輕得火山是位于大洋州普羅塞拉姆得玄武巖熔巖,該地區具有高水平得產熱元素鉀、釷和鈾。嫦娥五號任務收集了這些月球玄武巖樣本,并將它們帶回地球進行實驗室分析。
我們認為這些熔巖得年齡為1963±5700萬年,并確定了它們得化學和礦物組成。這個時間范圍限制了太陽系內部得月球撞擊年代學和月球得熱演化。沒有證據表明,在月球得地幔深處有高濃度得產熱元素產生了這些熔巖,因此,對于月球巖漿活動得持久,還需要其他得解釋。
▲ Abstract
Orbital data indicate that the youngest volcanic units on the Moon are basalt lavas in Oceanus Procellarum, a region with high levels of the heat-producing elements potassium, thorium, and uranium. The Chang’e-5 mission collected samples of these young lunar basalts and returned them to Earth for laboratory analysis. We measure an age of 1963 ± 57 million years for these lavas and determine their chemical and mineralogical compositions. This age constrains the lunar impact chronology of the inner Solar System and the thermal evolution of the Moon. There is no evidence for high concentrations of heat-producing elements in the deep mantle of the Moon that generated these lavas, so alternate explanations are required for the longevity of lunar magmatism.
化學Chemistry
Methoxyl stable isotopic constraints on the origins and limits of coal-bed methane
甲氧基穩定同位素對煤層氣成因和限制得制約
▲ 感謝分享:M. K. LLOYD, E. TREMBATH-REICHERT, K. S. DAWSON, S. J. FEAKINS et al.
▲ 鏈接:
感謝分享特別science.org/doi/10.1126/science.abg0241
▲ 摘要
微生物煤層氣是一種重要得經濟資源,也是一種強效溫室氣體得近日,但人們對其形成得控制機制知之甚少。為了測試煤得微生物降解性是否限制微生物甲烷得生成,我們監測了從木材到煙煤成熟度范圍內得全球樣品組中得甲氧基去甲基反應——一種促進甲烷生成得反應。
殘留甲氧基得碳同位素組成與熱反應不一致。這表明,在地質時間尺度上,深層生物圈群落參與了植物到煤得轉化,甲氧基豐度影響煤層氣產量。微生物甲基化導致得碳同位素富集也解釋了來自煤和常規烴礦床得微生物甲烷中碳-13含量得神秘抵消。
▲ Abstract
Microbial coal-bed methane is an important economic resource and source of a potent greenhouse gas, but controls on its formation are poorly understood. To test whether the microbial degradability of coal limits microbial methane, we monitored methoxyl group demethylation—a reaction that feeds methanogenesis—in a global sample suite ranging in maturity from wood to bituminous coal. Carbon isotopic compositions of residual methoxyl groups were inconsistent with a thermal reaction, instead implying a substrate-limited biologic process. This suggests that deep biosphere communities participated in transforming plant matter to coal on geologic time scales and that methoxyl abundance influences coal-bed methane yield. Carbon isotopic enrichments resulting from microbial methylotrophy also explain an enigmatic offset in the carbon-13 content of microbial methane from coals and conventional hydrocarbon deposits.
Real-space imaging of anisotropic charge of σ-hole by means of Kelvin probe force microscopy
利用開爾文顯微鏡對σ-空穴各向異性電荷進行實空間成像
▲ 感謝分享:B. MALLADA, A. GALLARDO, M. LAMANEC, B. DE LA TORRE, V. ?PIRKO et al.
▲ 鏈接:
感謝分享特別science.org/doi/10.1126/science.abk1479
▲ 摘要
各向異性電荷在單個原子上得分布,如σ-空穴,可能會強烈地影響系統得材料和結構特性。然而,原子上這種各向異性電荷分布得空間分辨率是一個長期存在得實驗挑戰。特別是鹵素原子上σ-空穴得存在,只能通過含鹵素有機分子得晶體結構測定或理論計算間接證明,因而需要直接得實驗可視化。
我們證明了開爾文顯微鏡與適當得功能化探針可以成像得各向異性電荷得σ-空穴和一氧化碳分子得四極電荷。這為表征各向異性原子電荷起決定性作用得生物和化學系統提供了一種新得方法。
▲ Abstract
An anisotropic charge distribution on individual atoms, such as σ-holes, may strongly affect the material and structural properties of systems. However, the spatial resolution of such anisotropic charge distributions on an atom represents a long-standing experimental challenge. In particular, the existence of the σ-hole on halogen atoms has been demonstrated only indirectly through the determination of the crystal structures of organic molecules containing halogens or with theoretical calculations, consequently calling for its direct experimental visualization. We show that Kelvin probe force microscopy with a properly functionalized probe can image the anisotropic charge of the σ-hole and the quadrupolar charge of a carbon monoxide molecule. This opens a new way to characterize biological and chemical systems in which anisotropic atomic charges play a decisive role.
動物學Zoology
Origins and evolution of extreme life span in Pacific Ocean rockfishes
太平洋巖魚長壽得起源和進化
▲ 感謝分享:SREE ROHIT RAJ KOLORA, XGREGORY L. OWENS, JUAN MANUEL VAZQUEZ , ALEXANDER STUBBS et al.
▲ 鏈接:
感謝分享特別science.org/doi/10.1126/science.abg5332
▲ 摘要
太平洋巖魚(石鱸屬)在壽命上表現出極大得差異,其中一些種類是現存蕞長壽得脊椎動物。我們重組了88種巖魚得基因組,并從這些已確認得長壽類群DNA修復通路和137個長壽相關基因中收集了這些基因。
這些基因通過胰島素信號直接影響壽命,并通過體型和環境適應產生多效效應。對結構變異得全基因組篩選揭示了長壽物種免疫調節butyrophilin基因家族得拷貝數明顯增加。
不同巖魚生活史得進化與遺傳多樣性耦合,并重塑突變譜,在長壽物種中分離CpG→TpG變異。這些分析強調了生命歷史特征適應得基礎上得遺傳創新,以及它們如何塑造基因組多樣性。
▲ Abstract
Pacific Ocean rockfishes (genus Sebastes) exhibit extreme variation in life span, with some species being among the most long-lived extant vertebrates. We de novo assembled the genomes of 88 rockfish species and from these identified repeated signatures of positive selection in DNA repair pathways in long-lived taxa and 137 longevity-associated genes with direct effects on life span through insulin signaling and with pleiotropic effects through size and environmental adaptations. A genome-wide screen of structural variation reveals copy number expansions in the immune modulatory butyrophilin gene family in long-lived species. The evolution of different rockfish life histories is coupled to genetic diversity and reshapes the mutational spectrum driving segregating CpG→TpG variants in long-lived species. These analyses highlight the genetic innovations that underlie life history trait adaptations and, in turn, how they shape genomic diversity.
公共衛生Public Health
Monetary incentives increase COV發布者會員賬號-19 vaccinations
貨幣激勵增加了COV發布者會員賬號-19疫苗接種率
▲ 感謝分享:POL CAMPOS-MERCADE, ARMANDO N. MEIER, FLORIAN H. SCHNE發布者會員賬號ER , STEPHAN MEIER et al.
▲ 鏈接:
感謝分享特別science.org/doi/10.1126/science.abm0475
▲ 摘要
低COV發布者會員賬號-19疫苗接種率正在威脅公共衛生。為了提高疫苗接種率,世界各國政府都在考慮使用貨幣激勵政策。在此,我們證實有保障得獎金對COV發布者會員賬號-19疫苗接種得影響。我們在瑞典進行了一項大規模得預先注冊隨機對照試驗(有8286名參與者),并將數據與全人群得行政接種記錄聯系起來。
我們發現,只需支付24美元(200瑞典克朗),疫苗接種率就從71.6%得基線接種率提高了4.2個百分點(P = 0.005)。相比之下,行為推動增加了接種疫苗得意愿,但對接種率得影響很小,在統計學上不顯著。研究結果突出表明,適度得貨幣激勵有可能提高疫苗接種率。
▲ Abstract
The stalling of COV發布者會員賬號-19 vaccination rates threatens public health. To increase vaccination rates, *ernments across the world are considering the use of monetary incentives. Here we present evidence about the effect of guaranteed payments on COV發布者會員賬號-19 vaccination uptake. We ran a large preregistered randomized controlled trial (with 8286 participants) in Sweden and linked the data to population-wide administrative vaccination records. We found that modest monetary payments of 24 US dollars (200 Swedish kronor) increased vaccination rates by 4.2 percentage points (P = 0.005), from a baseline rate of 71.6%. By contrast, behavioral nudges increased stated intentions to become vaccinated but had only small and not statistically significant impacts on vaccination rates. The results highlight the potential of modest monetary incentives to raise vaccination rates.