bluuebunny/crossref_metadata_2025_split huggingface dataset:
Arctic Ocean Freshening Linked to Anthropogenic Climate Change: All Hands on Deck
Authors: Haine Thomas W. N. 
Published: November 2020

AbstractArctic Ocean freshwater storage increased since the mid‐1990s, but the cause was unknown. Jahn and Laiho (2020, https://doi.org/10.1029/2020GL088854) use ensemble runs of a coupled climate model to suggest that the observed increase is anthropogenic. The paper quantifies when the anthropogenic signals should emerge from the noise of natural variability. This result contextualizes research on the Arctic Ocean freshwater system and sketches an unprecedented opportunity. Future work should elucidate mechanisms, seek to observe the anthropogenic freshwater changes, and investigate the impacts on biogeochemistry and the North Atlantic Ocean circulation.
Thermal Characterization of Pockmarks Across Vestnesa and Svyatogor Ridges, Offshore Svalbard
Authors: Riedel M. , Villinger H. , Freudenthal T. , Pape T. , Bünz S. , Bohrmann G. 
Published: November 2020

AbstractThe Svalbard margin represents one of the northernmost gas hydrate provinces worldwide. Vestnesa Ridge (VR) and Svyatogor Ridge (SR) west of Svalbard are two prominent sediment drifts showing abundant pockmarks and sites of seismic chimney structures. Some of these sites at VR are associated with active gas venting and were the focus of drilling and coring with the seafloor‐deployed MARUM‐MeBo70 rig. Understanding the nature of fluid migration and gas hydrate distribution requires (among other parameters) knowledge of the thermal regime and in situ gas and pore fluid composition. In situ temperature data were obtained downhole at a reference site at VR defining a geothermal gradient of ~78 mK m−1 (heat flow ~95 mW m−2). Additional heat probe data were obtained to describe the thermal regime of the pockmarks. The highest heat flow values were systematically seen within pockmark depressions and were uncorrelated to gas venting occurrences. Heat flow within pockmarks is typically ~20 mW m−2 higher than outside pockmarks. Using the downhole temperature data and gas compositions from drilling we model the regional base of the gas hydrate stability zone (BGHSZ). Thermal modeling including topographic effects suggest a BGHSZ up to 40 m deeper than estimated from seismic data. Uncertainties in sediment properties (velocity and thermal conductivity) are only partially explaining the mismatch. Capillary effects due to small sediment grain sizes may shift the free gas occurrence above the equilibrium BGHSZ. Changes in gas composition or pore fluid salinity at greater depth may also explain the discrepancy in observed and modeled BGHSZ.
Fluid Migration and Widespread Remagnetization in the Dabashan Fold and Thrust Belt, China
Authors: Zhang Yong , Jia Dong , Muxworthy Adrian R. , Zhang Yueqiao , Li Yongxiang , Yin Hongwei , Chen Zhuxin , Brzozowski Matthew J. , Li Wei , Wang Maomao , Li Zhigang 
Published: November 2020

AbstractTo better understand the fluid migration in orogenic zones and associated chemical remagnetization, we have conducted a detailed magnetic, petrographic, and strontium isotope study in an important orogenic belt of China, the Jurassic Dabashan fold and thrust belt. This belt formed by the continued collision of the North and South China blocks after the Late Triassic closure of the Paleo‐Tethys Ocean. Samples were collected in a variety of rock units of Ediacaran to Permian age, in both the thrust and the fold belts. Paleomagnetic analysis indicates that all the samples were remagnetized and carry a Middle‐Late Jurassic paleo‐direction. Rock magnetic data and scanning electron microscopy observations found that the proposed remagnetization is carried by framboidal magnetite, which likely formed by the replacement of pyrite. The pervasive nature of the chemical remagnetization in these units and belts and its temporal and spatial association with the orogeny suggest that it resulted from the alteration of orogeny‐induced fluids. Sr‐isotopic analysis of the units that are thought to be remagnetized suggests that the sediments in the thrust belt were altered by externally derived evolved fluids, whereas the Permian samples in the fold belt were altered by internal pore fluid mixing during the orogeny. Together with the lithological and structural features, we conclude that the external orogenic fluids migrated preferentially along thrust faults and unconformities but were blocked by layers of low‐permeability gypsum. Our results help to constrain the origin of widespread remagnetization in South China.
The Response of the Northern Hemisphere Storm Tracks and Jet Streams to Climate Change in the CMIP3, CMIP5, and CMIP6 Climate Models
Authors: Harvey B. J. , Cook P. , Shaffrey L. C. , Schiemann R. 
Published: November 2020

AbstractThe representation of the Northern Hemisphere (NH) storm tracks and jet streams and their response to climate change have been evaluated in climate model simulations from Phases 3, 5, and 6 of the Coupled Model Intercomparison Project (CMIP3, CMIP5, and CMIP6, respectively). The spatial patterns of the multimodel biases in CMIP3, CMIP5, and CMIP6 are similar; however, the magnitudes of the biases in the CMIP6 models are substantially lower. For instance, the multimodel mean RMSE of the North Atlantic storm track for the CMIP6 models (as measured by time‐filtered sea‐level pressure variance) is over 50% smaller than that of the CMIP3 models in both winter and summer, and over 40% smaller for the North Pacific. The magnitude of the jet stream biases is also reduced in CMIP6, but by a lesser extent. Despite this improved representation of the current climate, the spatial patterns of the climate change response of the NH storm tracks and jet streams remain similar in the CMIP3, CMIP5, and CMIP6 models. The SSP2‐4.5 scenario responses in the CMIP6 models are substantially larger than in the RCP4.5 CMIP5 models, which is consistent with the larger climate sensitivities of the CMIP6 models compared to CMIP5.
How Wind Shear Affects Trade‐wind Cumulus Convection
Authors: Helfer K. C. , Nuijens L. , de Roode S. R. , Siebesma A. P. 
Published: November 2020

AbstractMotivated by an observed relationship between marine low cloud cover and surface wind speed, this study investigates how vertical wind shear affects trade‐wind cumulus convection, including shallow cumulus and congestus with tops below the freezing level. We ran large‐eddy simulations for an idealized case of trade‐wind convection using different vertical shears in the zonal wind. Backward shear, whereby surface easterlies become upper westerlies, is effective at limiting vertical cloud development, which leads to a moister, shallower, and cloudier trade‐wind layer. Without shear or with forward shear, shallow convection tends to deepen more, but clouds tops are still limited under forward shear. A number of mechanisms explain the observed behavior: First, shear leads to different surface wind speeds and, in turn, surface heat and moisture fluxes due to momentum transport, whereby the weakest surface wind speeds develop under backward shear. Second, a forward shear profile in the subcloud layer enhances moisture aggregation and leads to larger cloud clusters, but only on large domains that generally support cloud organization. Third, any absolute amount of shear across the cloud layer limits updraft speeds by enhancing the downward oriented pressure perturbation force. Backward shear—the most typical shear found in the winter trades—can thus be argued a key ingredient at setting the typical structure of the trade‐wind layer.
Active Deformation and Relief Evolution in the Western Lurestan Region of the Zagros Mountain Belt: New Insights From Tectonic Geomorphology Analysis and Finite Element Modeling
Authors: Basilici Matteo , Ascione Alessandra , Megna Antonella , Santini Stefano , Tavani Stefano , Valente Ettore , Mazzoli Stefano 
Published: November 2020

AbstractTo unravel how and where coseismic and interseismic deformation impacts the spatial and temporal patterns of rock uplift of the Lurestan sector of the Zagros Mountains, we performed an investigation of the large‐scale features of topography and river network coupled with 2‐D finite element modeling. Geomorphological analysis and constraints from parameters such as elevation, local relief, normalized channel steepness index (ksn), river longitudinal profiles, and transformed river profiles (chi plots) were used to unravel the time‐space distribution of vertical motions. Whereas the much longer timescale over which topography grows and/or rivers respond to tectonic or climatic perturbations with respect to even multiple seismic cycles, the outputs of the finite element model yield fundamental information on the source of the late part of the spatiotemporal evolution of surface uplift recorded by the geomorphology. Model outputs shed new light into the processes controlling relief evolution in an actively growing mountain belt underlain by a major blind thrust. The outputs illustrate how coseismic slip controls localized uplift of a prominent topographic feature—the Mountain Front Flexure—located above the main upper crustal ramp of the principal basement thrust fault of the region, while continuous displacement along the deeper, aseismic portion of the same basement fault controls generalized uplift of the whole crustal block located farther to the NE, in the interior of the orogen.
Upscaling of Solute Plumes in Periodic Porous Media Through a Trajectory‐Based Spatial Markov Model
Authors: Bianchi Janetti Emanuela , Sherman Thomas , Guédon Gaël Raymond , Bolster Diogo , Porta Giovanni M. 
Published: November 2020

AbstractWe propose an approach to upscale solute transport in spatially periodic porous media. Our methodology relies on pore‐scale information to predict large‐scale transport features, including explicit reconstruction of the solute plume, breakthrough curves at fixed distances, and spatial spreading transverse to the main flow direction. The proposed approach is grounded on the recently proposed trajectory‐based spatial Markov model (tSMM), which upscales transport based on information collected from advective‐diffusive particle trajectories across one periodic element. In previous works, this model has been applied solely to one‐dimensional transport in a single periodic pore geometry. In this work we extend the tSMM to the prediction of multidimensional solute plumes. This is obtained by analyzing the joint space‐time probability distribution associated with discrete particles, as yielded by the tSMM. By comparing numerical results from fully resolved simulations and predictions obtained with the tSMM over a wide range of Péclet numbers, we demonstrate that the proposed approach is suitable for modeling transport of conservative and linearly decaying solute species in a realistic pore space and showcase the applicability of the model to predict steady‐state solute plumes. Additionally, we evaluate the model performance as a function of numerical parameters employed in the tSMM parameterization.
Race/ethnicity in systemic AL amyloidosis: perspectives on disease and outcome disparities
Authors: Staron Andrew , Connors Lawreen H. , Zheng Luke , Doros Gheorghe , Sanchorawala Vaishali 
Published: November 2020

AbstractIn marked contrast to multiple myeloma, racial/ethnic minorities are underrepresented in publications of systemic light-chain (AL) amyloidosis. The impact of race/ethnicity is therefore lacking in the narrative of this disease. To address this gap, we compared disease characteristics, treatments, and outcomes across racial/ethnic groups in a referred cohort of patients with AL amyloidosis from 1990 to 2020. Among 2416 patients, 14% were minorities. Non-Hispanic Blacks (NHBs) comprised 8% and had higher-risk sociodemographic factors. Hispanics comprised 4% and presented with disproportionately more BU stage IIIb cardiac involvement (27% vs. 4–17%). At onset, minority groups were younger in age by 4–6 years. There was indication of more aggressive disease phenotype among NHBs with higher prevalence of difference between involved and uninvolved free light chains >180 mg/L (39% vs. 22–33%, P = 0.044). Receipt of stem cell transplantation was 30% lower in Hispanics compared to non-Hispanic White (NHWs) on account of sociodemographic and physiologic factors. Although the age/sex-adjusted hazard for death among NHBs was 24% higher relative to NHWs (P = 0.020), race/ethnicity itself did not impact survival after controlling for disease severity and treatment variables. These findings highlight the complexities of racial/ethnic disparities in AL amyloidosis. Directed efforts by providers and advocacy groups are needed to expand access to testing and effective treatments within underprivileged communities.
Distinct CCK-positive SFO neurons are involved in persistent or transient suppression of water intake
Authors: Matsuda Takashi , Hiyama Takeshi Y. , Kobayashi Kenta , Kobayashi Kazuto , Noda Masaharu 
Published: November 2020

AbstractThe control of water-intake behavior is critical for life because an excessive water intake induces pathological conditions, such as hyponatremia or water intoxication. However, the brain mechanisms controlling water intake currently remain unclear. We previously reported that thirst-driving neurons (water neurons) in the subfornical organ (SFO) are cholecystokinin (CCK)-dependently suppressed by GABAergic interneurons under Na-depleted conditions. We herein show that CCK-producing excitatory neurons in the SFO stimulate the activity of GABAergic interneurons via CCK-B receptors. Fluorescence-microscopic Ca2+ imaging demonstrates two distinct subpopulations in CCK-positive neurons in the SFO, which are persistently activated under hyponatremic conditions or transiently activated in response to water drinking, respectively. Optical and chemogenetic silencings of the respective types of CCK-positive neurons both significantly increase water intake under water-repleted conditions. The present study thus reveals CCK-mediated neural mechanisms in the central nervous system for the control of water-intake behaviors.
Space station biomining experiment demonstrates rare earth element extraction in microgravity and Mars gravity
Authors: Cockell Charles S. , Santomartino Rosa , Finster Kai , Waajen Annemiek C. , Eades Lorna J. , Moeller Ralf , Rettberg Petra , Fuchs Felix M. , Van Houdt Rob , Leys Natalie , Coninx Ilse , Hatton Jason , Parmitano Luca , Krause Jutta , Koehler Andrea , Caplin Nicol , Zuijderduijn Lobke , Mariani Alessandro , Pellari Stefano S. , Carubia Fabrizio , Luciani Giacomo , Balsamo Michele , Zolesi Valfredo , Nicholson Natasha , Loudon Claire-Marie , Doswald-Winkler Jeannine , Herová Magdalena , Rattenbacher Bernd , Wadsworth Jennifer , Craig Everroad R. , Demets René 
Published: November 2020

AbstractMicroorganisms are employed to mine economically important elements from rocks, including the rare earth elements (REEs), used in electronic industries and alloy production. We carried out a mining experiment on the International Space Station to test hypotheses on the bioleaching of REEs from basaltic rock in microgravity and simulated Mars and Earth gravities using three microorganisms and a purposely designed biomining reactor. Sphingomonas desiccabilis enhanced mean leached concentrations of REEs compared to non-biological controls in all gravity conditions. No significant difference in final yields was observed between gravity conditions, showing the efficacy of the process under different gravity regimens. Bacillus subtilis exhibited a reduction in bioleaching efficacy and Cupriavidus metallidurans showed no difference compared to non-biological controls, showing the microbial specificity of the process, as on Earth. These data demonstrate the potential for space biomining and the principles of a reactor to advance human industry and mining beyond Earth.
Slim-panel holographic video display
Authors: An Jungkwuen , Won Kanghee , Kim Young , Hong Jong-Young , Kim Hojung , Kim Yongkyu , Song Hoon , Choi Chilsung , Kim Yunhee , Seo Juwon , Morozov Alexander , Park Hyunsik , Hong Sunghoon , Hwang Sungwoo , Kim Kichul , Lee Hong-Seok 
Published: November 2020

AbstractSince its discovery almost 70 years ago, the hologram has been considered to reproduce the most realistic three dimensional images without visual side effects. Holographic video has been extensively researched for commercialization, since Benton et al. at MIT Media Lab developed the first holographic video systems in 1990. However, commercially available holographic video displays have not been introduced yet for several reasons: narrow viewing angle, bulky optics and heavy computing power. Here we present an interactive slim-panel holographic video display using a steering-backlight unit and a holographic video processor to solve the above issues. The steering-backlight unit enables to expand the viewing angle by 30 times and its diffractive waveguide architecture makes a slim display form-factor. The holographic video processor computes high quality holograms in real-time on a single-chip. We suggest that the slim-panel holographic display can provide realistic three-dimensional video in office and household environments.
Trans-basin Atlantic-Pacific connections further weakened by common model Pacific mean SST biases
Authors: Li Chen , Dommenget Dietmar , McGregor Shayne 
Published: November 2020

AbstractA robust eastern Pacific surface temperature cooling trend was evident between ~1990–2013 that was considered as a pronounced contributor to the global surface warming slowdown. The majority of current climate models failed to reproduce this Pacific cooling trend, which is at least partly due to the underrepresentation of trans-basin teleconnections. Here, we investigate whether common Pacific mean sea surface temperature biases may further diminish the Atlantic-Pacific trans-basin induced Pacific cooling. Our results suggest that background Pacific SST biases act to weaken the trans-basin teleconnection by strengthening the Atlantic atmospheric stability and reducing Atlantic convection. These Pacific SST biases also act to substantially undermine the positive zonal wind-SST feedback. Furthermore, when combined, the Pacific and Atlantic SST biases led to Pacific cooling response that is almost non-existent (underestimated by 89%). Future efforts aim at reducing the model mean state biases may significantly help to improve the simulation skills of trans-basin teleconnections.
NeoR, a near-infrared absorbing rhodopsin
Authors: Broser Matthias , Spreen Anika , Konold Patrick E. , Schiewer Enrico , Adam Suliman , Borin Veniamin , Schapiro Igor , Seifert Reinhard , Kennis John T. M. , Bernal Sierra Yinth Andrea , Hegemann Peter 
Published: November 2020

AbstractThe Rhizoclosmatium globosum genome encodes three rhodopsin-guanylyl cyclases (RGCs), which are predicted to facilitate visual orientation of the fungal zoospores. Here, we show that RGC1 and RGC2 function as light-activated cyclases only upon heterodimerization with RGC3 (NeoR). RGC1/2 utilize conventional green or blue-light-sensitive rhodopsins (λmax = 550 and 480 nm, respectively), with short-lived signaling states, responsible for light-activation of the enzyme. The bistable NeoR is photoswitchable between a near-infrared-sensitive (NIR, λmax = 690 nm) highly fluorescent state (QF = 0.2) and a UV-sensitive non-fluorescent state, thereby modulating the activity by NIR pre-illumination. No other rhodopsin has been reported so far to be functional as a heterooligomer, or as having such a long wavelength absorption or high fluorescence yield. Site-specific mutagenesis and hybrid quantum mechanics/molecular mechanics simulations support the idea that the unusual photochemical properties result from the rigidity of the retinal chromophore and a unique counterion triad composed of two glutamic and one aspartic acids. These findings substantially expand our understanding of the natural potential and limitations of spectral tuning in rhodopsin photoreceptors.
Single-cell analysis of developing and azoospermia human testicles reveals central role of Sertoli cells
Authors: Zhao LiangYu , Yao ChenCheng , Xing XiaoYu , Jing Tao , Li Peng , Zhu ZiJue , Yang Chao , Zhai Jing , Tian RuHui , Chen HuiXing , Luo JiaQiang , Liu NaChuan , Deng ZhiWen , Lin XiaoHan , Li Na , Fang Jing , Sun Jie , Wang ChenChen , Zhou Zhi , Li Zheng 
Published: November 2020

AbstractClinical efficacy of treatments against non-obstructive azoospermia (NOA), which affects 1% of men, are currently limited by the incomplete understanding of NOA pathogenesis and normal spermatogenic microenvironment. Here, we profile >80,000 human testicular single-cell transcriptomes from 10 healthy donors spanning the range from infant to adult and 7 NOA patients. We show that Sertoli cells, which form the scaffold in the testicular microenvironment, are severely damaged in NOA patients and identify the roadmap of Sertoli cell maturation. Notably, Sertoli cells of patients with congenital causes (Klinefelter syndrome and Y chromosome microdeletions) are mature, but exhibit abnormal immune responses, while the cells in idiopathic NOA (iNOA) are physiologically immature. Furthermore, we find that inhibition of Wnt signaling promotes the maturation of Sertoli cells from iNOA patients, allowing these cells to regain their ability to support germ cell survival. We provide a novel perspective on the development of diagnostic methods and therapeutic targets for NOA.
Strategies for simultaneous strengthening and toughening via nanoscopic intracrystalline defects in a biogenic ceramic
Authors: Deng Zhifei , Chen Hongshun , Yang Ting , Jia Zian , Weaver James C. , Shevchenko Pavel D. , De Carlo Francesco , Mirzaeifar Reza , Li Ling 
Published: November 2020

AbstractWhile many organisms synthesize robust skeletal composites consisting of spatially discrete organic and mineral (ceramic) phases, the intrinsic mechanical properties of the mineral phases are poorly understood. Using the shell of the marine bivalve Atrina rigida as a model system, and through a combination of multiscale structural and mechanical characterization in conjunction with theoretical and computational modeling, we uncover the underlying mechanical roles of a ubiquitous structural motif in biogenic calcite, their nanoscopic intracrystalline defects. These nanoscopic defects not only suppress the soft yielding of pure calcite through the classical precipitation strengthening mechanism, but also enhance energy dissipation through controlled nano- and micro-fracture, where the defects’ size, geometry, orientation, and distribution facilitate and guide crack initialization and propagation. These nano- and micro-scale cracks are further confined by larger scale intercrystalline organic interfaces, enabling further improved damage tolerance.