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Marine organic matter in the remote environment of the Cape Verde islands - an introduction and overview to the MarParCloud campaign 期刊论文
ATMOSPHERIC CHEMISTRY AND PHYSICS, 2020, 20 (11) : 6921-6951
作者:  van Pinxteren, Manuela;  Fomba, Khanneh Wadinga;  Triesch, Nadja;  Stolle, Christian;  Wurl, Oliver;  Bahlmann, Enno;  Gong, Xianda;  Voigtlaender, Jens;  Wex, Heike;  Robinson, Tiera-Brandy;  Barthel, Stefan;  Zeppenfeld, Sebastian;  Hoffmann, Erik Hans;  Roveretto, Marie;  Li, Chunlin;  Grosselin, Benoit;  Daele, Veronique;  Senf, Fabian;  van Pinxteren, Dominik;  Manzi, Malena;  Zabalegui, Nicolas;  Frka, Sanja;  Gasparovic, Blazenka;  Pereira, Ryan;  Li, Tao;  Wen, Liang;  Li, Jiarong;  Zhu, Chao;  Chen, Hui;  Chen, Jianmin;  Fiedler, Bjoern;  Von Tuempling, Wolf;  Read, Katie Alana;  Punjabi, Shalini;  Lewis, Alastair Charles;  Hopkins, James Roland;  Carpenter, Lucy Jane;  Peeken, Ilka;  Rixen, Tim;  Schulz-Bull, Detlef;  Monge, Maria Eugenia;  Mellouki, Abdelwahid;  George, Christian;  Stratmann, Frank;  Herrmann, Hartmut
收藏  |  浏览/下载:23/0  |  提交时间:2020/08/18
Quantifying uncertainties of climate signals in chemistry climate models related to the 11-year solar cycle - Part 1: Annual mean response in heating rates, temperature, and ozone 期刊论文
ATMOSPHERIC CHEMISTRY AND PHYSICS, 2020, 20 (11) : 6991-7019
作者:  Kunze, Markus;  Kruschke, Tim;  Langematz, Ulrike;  Sinnhuber, Miriam;  Reddmann, Thomas;  Matthes, Katja
收藏  |  浏览/下载:11/0  |  提交时间:2020/06/16
Massive formation of early diagenetic dolomite in the Ediacaran ocean: Constraints on the "dolomite problem" 期刊论文
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA, 2020, 117 (25) : 14005-14014
作者:  Chang, Biao;  Li, Chao;  Liu, Deng;  Foster, Ian;  Tripati, Aradhna;  Lloyd, Max K.;  Maradiaga, Ingrid;  Luo, Genming;  An, Zhihui;  She, Zhenbing;  Xie, Shucheng;  Tong, Jinnan;  Huang, Junhua;  Algeo, Thomas J.;  Lyons, Timothy W.;  Immenhauser, Adrian
收藏  |  浏览/下载:17/0  |  提交时间:2020/06/16
Doushantuo Formation  clumped isotope  early diagenesis  carbonate geochemistry  early oceans  
Estimating US fossil fuel CO2 emissions from measurements of C-14 in atmospheric CO2 期刊论文
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA, 2020, 117 (24) : 13300-13307
作者:  Basu, Sourish;  Lehman, Scott J.;  Miller, John B.;  Andrews, Arlyn E.;  Sweeney, Colm;  Gurney, Kevin R.;  Xu, Xiaomei;  Southon, John;  Tans, Pieter P.
收藏  |  浏览/下载:14/0  |  提交时间:2020/06/09
fossil fuel CO2  radiocarbon  atmospheric inverse modeling  
Nearest neighbours reveal fast and slow components of motor learning 期刊论文
NATURE, 2020, 577 (7791) : 526-+
作者:  Kollmorgen, Sepp;  Hahnloser, Richard H. R.;  Mante, Valerio
收藏  |  浏览/下载:4/0  |  提交时间:2020/07/03

A new method for analysing change in high-dimensional data is based on nearest-neighbour statistics and is applied here to song dynamics during vocal learning in zebra finches, but could potentially be applied to other biological and artificial behaviours.


Changes in behaviour resulting from environmental influences, development and learning(1-5) are commonly quantified on the basis of a few hand-picked features(2-4,6,7) (for example, the average pitch of acoustic vocalizations(3)), assuming discrete classes of behaviours (such as distinct vocal syllables)(2,3,8-10). However, such methods generalize poorly across different behaviours and model systems and may miss important components of change. Here we present a more-general account of behavioural change that is based on nearest-neighbour statistics(11-13), and apply it to song development in a songbird, the zebra finch(3). First, we introduce the concept of '  repertoire dating'  , whereby each rendition of a behaviour (for example, each vocalization) is assigned a repertoire time, reflecting when similar renditions were typical in the behavioural repertoire. Repertoire time isolates the components of vocal variability that are congruent with long-term changes due to vocal learning and development, and stratifies the behavioural repertoire into '  regressions'  , '  anticipations'  and '  typical renditions'  . Second, we obtain a holistic, yet low-dimensional, description of vocal change in terms of a stratified '  behavioural trajectory'  , revealing numerous previously unrecognized components of behavioural change on fast and slow timescales, as well as distinct patterns of overnight consolidation(1,2,4,14,15) across the behavioral repertoire. We find that diurnal changes in regressions undergo only weak consolidation, whereas anticipations and typical renditions consolidate fully. Because of its generality, our nonparametric description of how behaviour evolves relative to itself-rather than to a potentially arbitrary, experimenter-defined goal(2,3,14,16)-appears well suited for comparing learning and change across behaviours and species(17,18), as well as biological and artificial systems(5).


  
Millennial-scale hydroclimate control of tropical soil carbon storage 期刊论文
NATURE, 2020, 581 (7806) : 63-+
作者:  Lam, Tommy Tsan-Yuk;  Jia, Na;  Zhang, Ya-Wei;  Shum, Marcus Ho-Hin;  Jiang, Jia-Fu;  Zhu, Hua-Chen;  Tong, Yi-Gang;  Shi, Yong-Xia;  Ni, Xue-Bing;  Liao, Yun-Shi;  Li, Wen-Juan;  Jiang, Bao-Gui;  Wei, Wei;  Yuan, Ting-Ting;  Zheng, Kui;  Cui, Xiao-Ming;  Li, Jie;  Pei, Guang-Qian
收藏  |  浏览/下载:25/0  |  提交时间:2020/05/13

Over the past 18,000 years, the residence time and amount of soil carbon stored in the Ganges-Brahmaputra basin have been controlled by the intensity of Indian Summer Monsoon rainfall, with greater carbon destabilization during wetter, warmer conditions.


The storage of organic carbon in the terrestrial biosphere directly affects atmospheric concentrations of carbon dioxide over a wide range of timescales. Within the terrestrial biosphere, the magnitude of carbon storage can vary in response to environmental perturbations such as changing temperature or hydroclimate(1), potentially generating feedback on the atmospheric inventory of carbon dioxide. Although temperature controls the storage of soil organic carbon at mid and high latitudes(2,3), hydroclimate may be the dominant driver of soil carbon persistence in the tropics(4,5)  however, the sensitivity of tropical soil carbon turnover to large-scale hydroclimate variability remains poorly understood. Here we show that changes in Indian Summer Monsoon rainfall have controlled the residence time of soil carbon in the Ganges-Brahmaputra basin over the past 18,000 years. Comparison of radiocarbon ages of bulk organic carbon and terrestrial higher-plant biomarkers with co-located palaeohydrological records(6) reveals a negative relationship between monsoon rainfall and soil organic carbon stocks on a millennial timescale. Across the deglaciation period, a depletion of basin-wide soil carbon stocks was triggered by increasing rainfall and associated enhanced soil respiration rates. Our results suggest that future hydroclimate changes in tropical regions are likely to accelerate soil carbon destabilization, further increasing atmospheric carbon dioxide concentrations.


  
IL-17a promotes sociability in mouse models of neurodevelopmental disorders 期刊论文
NATURE, 2020, 577 (7789) : 249-+
作者:  Reed, Michael Douglas;  Yim, Yeong Shin;  Wimmer, Ralf D.;  Kim, Hyunju;  Ryu, Changhyeon;  Welch, Gwyneth Margaret;  Andina, Matias;  King, Hunter Oren;  Waisman, Ari;  Halassa, Michael M.;  Huh, Jun R.;  Choi, Gloria B.
收藏  |  浏览/下载:11/0  |  提交时间:2020/07/03

A subset of children with autism spectrum disorder appear to show an improvement in their behavioural symptoms during the course of a fever, a sign of systemic inflammation(1,2). Here we elucidate the molecular and neural mechanisms that underlie the beneficial effects of inflammation on social behaviour deficits in mice. We compared an environmental model of neurodevelopmental disorders in which mice were exposed to maternal immune activation (MIA) during embryogenesis(3,4) with mouse models that are genetically deficient for contactin-associated protein-like 2 (Cntnap2)(5), fragile X mental retardation-1 (Fmr1)(6) or Sh3 and multiple ankyrin repeat domains 3 (Shank3)(7). We establish that the social behaviour deficits in offspring exposed to MIA can be temporarily rescued by the inflammatory response elicited by the administration of lipopolysaccharide (LPS). This behavioural rescue was accompanied by a reduction in neuronal activity in the primary somatosensory cortex dysgranular zone (S1DZ), the hyperactivity of which was previously implicated in the manifestation of behavioural phenotypes associated with offspring exposed to MIA(8). By contrast, we did not observe an LPS-induced rescue of social deficits in the monogenic models. We demonstrate that the differences in responsiveness to the LPS treatment between the MIA and the monogenic models emerge from differences in the levels of cytokine production. LPS treatment in monogenic mutant mice did not induce amounts of interleukin-17a (IL-17a) comparable to those induced in MIA offspring  bypassing this difference by directly delivering IL-17a into S1DZ was sufficient to promote sociability in monogenic mutant mice as well as in MIA offspring. Conversely, abrogating the expression of IL-17 receptor subunit a (IL-17Ra) in the neurons of the S1DZ eliminated the ability of LPS to reverse the sociability phenotypes in MIA offspring. Our data support a neuroimmune mechanism that underlies neurodevelopmental disorders in which the production of IL-17a during inflammation can ameliorate the expression of social behaviour deficits by directly affecting neuronal activity in the central nervous system.


  
OCEAN DATA NEED A SEA CHANGE TO HELP NAVIGATE THE WARMING WORLD 期刊论文
NATURE, 2020, 582 (7811) : 181-183
作者:  Safronova, Marianna S.
收藏  |  浏览/下载:0/0  |  提交时间:2020/07/03
Lineage dynamics of the endosymbiotic cell type in the soft coralXenia 期刊论文
NATURE, 2020
作者:  Lewnard, Joseph A.;  Lo, Nathan C.;  Arinaminpathy, Nimalan;  Frost, Isabel;  Laxminarayan, Ramanan
收藏  |  浏览/下载:14/0  |  提交时间:2020/07/03

Many corals harbour symbiotic dinoflagellate algae. The algae live inside coral cells in a specialized membrane compartment known as the symbiosome, which shares the photosynthetically fixed carbon with coral host cells while host cells provide inorganic carbon to the algae for photosynthesis(1). This endosymbiosis-which is critical for the maintenance of coral reef ecosystems-is increasingly threatened by environmental stressors that lead to coral bleaching (that is, the disruption of endosymbiosis), which in turn leads to coral death and the degradation of marine ecosystems(2). The molecular pathways that orchestrate the recognition, uptake and maintenance of algae in coral cells remain poorly understood. Here we report the chromosome-level genome assembly of aXeniaspecies of fast-growing soft coral(3), and use this species as a model to investigate coral-alga endosymbiosis. Single-cell RNA sequencing identified 16 cell clusters, including gastrodermal cells and cnidocytes, inXeniasp. We identified the endosymbiotic cell type, which expresses a distinct set of genes that are implicated in the recognition, phagocytosis and/or endocytosis, and maintenance of algae, as well as in the immune modulation of host coral cells. By couplingXeniasp. regeneration and single-cell RNA sequencing, we observed a dynamic lineage progression of the endosymbiotic cells. The conserved genes associated with endosymbiosis that are reported here may help to reveal common principles by which different corals take up or lose their endosymbionts.


  
The first dinosaur egg was soft 期刊论文
NATURE, 2020
作者:  Rodstrom, Karin E. J.;  Kiper, Aytug K.;  Zhang, Wei;  Rinne, Susanne;  Pike, Ashley C. W.;  Goldstein, Matthias;  Conrad, Linus J.;  Delbeck, Martina;  Hahn, Michael G.;  Meier, Heinrich;  Platzk, Magdalena;  Quigley, Andrew;  Speedman, David;  Shrestha, Leela;  Mukhopadhyay, Shubhashish M. M.
收藏  |  浏览/下载:47/0  |  提交时间:2020/07/03

Molecular analyses of newly discovered, embryo-bearing ornithischian and sauropod dinosaur eggs suggest that the ancestral dinosaur egg was soft-shelled, and that hard-shelled eggs evolved independently at least three times in the major dinosaur lineages.


Calcified eggshells protect developing embryos against environmental stress and contribute to reproductive success(1). As modern crocodilians and birds lay hard-shelled eggs, this eggshell type has been inferred for non-avian dinosaurs. Known dinosaur eggshells are characterized by an innermost membrane, an overlying protein matrix containing calcite, and an outermost waxy cuticle(2-7). The calcitic eggshell consists of one or more ultrastructural layers that differ markedly among the three major dinosaur clades, as do the configurations of respiratory pores. So far, only hadrosaurid, a few sauropodomorph and tetanuran eggshells have been discovered  the paucity of the fossil record and the lack of intermediate eggshell types challenge efforts to homologize eggshell structures across all dinosaurs(8-18). Here we present mineralogical, organochemical and ultrastructural evidence for an originally non-biomineralized, soft-shelled nature of exceptionally preserved ornithischianProtoceratopsand basal sauropodomorphMussauruseggs. Statistical evaluation of in situ Raman spectra obtained for a representative set of hard- and soft-shelled, fossil and extant diapsid eggshells clusters the originally organic but secondarily phosphatizedProtoceratopsand the organicMussauruseggshells with soft, non-biomineralized eggshells. Histology corroborates the organic composition of these soft-shelled dinosaur eggs, revealing a stratified arrangement resembling turtle soft eggshell. Through an ancestral-state reconstruction of composition and ultrastructure, we compare eggshells fromProtoceratopsandMussauruswith those from other diapsids, revealing that the first dinosaur egg was soft-shelled. The calcified, hard-shelled dinosaur egg evolved independently at least three times throughout the Mesozoic era, explaining the bias towards eggshells of derived dinosaurs in the fossil record.