bluuebunny/crossref_metadata_2025_split huggingface dataset:
Multiscale and Multispectral Characterization of Mineralogy with the ExoMars 2022 Rover Remote Sensing Payload
Authors: Allender E. J. , Cousins C. R. , Gunn M. D. , Caudill C. M. 
Published: February 2020

AbstractIn 2022, the European Space Agency and Roscosmos will launch the ExoMars rover, with the scientific objective to detect evidence of life within the Martian surface via the deployment of a 2 m drill. The ExoMars Pasteur payload contains several imaging and spectroscopic instruments key to this objective: the Panoramic Camera (PanCam), Infrared Spectrometer for ExoMars (ISEM), and Close‐UP Imager (CLUPI). These instruments are able to collect data at a variety of spatial (sub‐mm to decimeter) and spectral (3.3 to 120 nm) resolutions across the 440 to 3,300 nm wavelength range and collectively will form a picture of the geological and morphological characteristics of the surface terrain surrounding the rover. We deployed emulators of this instrument suite at terrestrial analog sites that formed in a range of aqueous environments to test their ability to detect and characterize science targets. We find that the emulator suite is able to effectively detect, characterize, and refine the compositions of multiple targets at working distances spanning from 2 to 18 m. We report on (a) the detection of hydrothermal alteration minerals including Fe‐smectites and gypsum from basaltic substrates, (b) the detection of late‐stage diagenetic gypsum veins embedded in exposures of sedimentary mudstone, (c) multispectral evidence of compositional differences detected from fossiliferous mudstones, and (d) approaches to cross‐referencing multi‐scale and multi‐resolution data. These findings aid in the development of data products and analysis toolkits in advance of the ExoMars rover mission.
Evaluation of Different Heat Flux Products Over the Tropical Indian Ocean
Authors: Pokhrel Samir , Dutta Ushnanshu , Rahaman Hasibur , Chaudhari Hemantkumar , Hazra Anupam , Saha Subodh Kumar , Veeranjaneyulu Chinta 
Published: January 2020

AbstractNet heat flux (Qnet) and its components from four reanalysis (NCEP‐2, CFSR, ERA5, and MERRA) and two blended products (OAFlux & TropFlux) are compared with in situ observation (two Research Moored Array for African‐Asian‐Australian Monsoon Analysis and Prediction buoys and one Woods Hole Oceanographic Institution buoy) over the north Indian Ocean to quantify their uncertainties in daily, seasonal, and annual scales. These comparisons provide the present status of Qnet error in most state of the art reanalysis/blended products. The root‐mean‐square error (RMSE) remains similar to the RMSE a decade earlier, despite more observation and improved models and reanalysis methods. However, there is a clear separation of flux quality from the older generation of reanalysis (NCEP‐2) to the newer production of reanalysis (MERRA, CFSR, and ERA5). While individually ERA5 provides the best estimate, the ensemble mean (i.e., average of ERA5, CFSR, MERRA, TropFlux, and OAFlux) is very close to ERA5 both in terms of correlations and RMSE and provides the most reliable estimate by virtue of removal of some of the uncertainties in estimation of flux by each of the flux products. A significant reduction of RMSE in Qnet estimates from 100 W/m2 (in NCEP‐2) to 45 W/m2 (in the ensemble mean) is considerable progress. It is noteworthy that all the recent flux products estimate the increasing trend of Qnet in the north Bay of Bengal and subseasonal fluctuations with significant fidelity. Also, in the south of equator location vigorous subseasonal fluctuations in boreal winter are well captured. We believe that this is significant progress in the estimation of Qnet over the Indian Ocean.
High Peak‐Current Lightning Discharges Associated With Downward Terrestrial Gamma‐Ray Flashes
Authors: Wada Y. , Enoto T. , Nakamura Y. , Morimoto T. , Sato M. , Ushio T. , Nakazawa K. , Yuasa T. , Yonetoku D. , Sawano T. , Kamogawa M. , Sakai H. , Furuta Y. , Makishima K. , Tsuchiya H. 
Published: January 2020

AbstractDuring 2017–2018 winter operation of the Gamma‐Ray Observation of Winter Thunderclouds experiment in Japan, two downward terrestrial gamma‐ray flashes (TGFs) that triggered atmospheric photonuclear reactions were detected. They took place during winter thunderstorms on 5 December 2017 and 9 January 2018 at Kanazawa, Ishikawa Prefecture, Japan. Each event coincided with an intracloud/intercloud discharge, which had a negative‐polarity peak current higher than 150 kA. Their radio waveforms in the low‐frequency band are categorized as a distinct lightning type called “energetic in‐cloud pulse” (EIP). Negative‐polarity EIPs have been previously suggested to be highly associated with downward TGFs, and the present observations provide evidence of the correlation between them for the first time. Furthermore, both of the downward TGFs followed “gamma‐ray glows,” minute‐lasting high‐energy emissions from thunderclouds. It is suggested that the negative EIPs took place with downward propagating negative leaders or upward positive ones developed in highly electrified regions responsible for the gamma‐ray glows.
The Extraterrestrial Dust Flux: Size Distribution and Mass Contribution Estimates Inferred From the Transantarctic Mountains (TAM) Micrometeorite Collection
Authors: Suttle M. D. , Folco L. 
Published: January 2020

AbstractThis study explores the long‐duration (0.8–2.3 Ma), time‐averaged micrometeorite flux (mass and size distribution) reaching Earth, as recorded by the Transantarctic Mountains (TAM) micrometeorite collection. We investigate a single sediment trap (TAM65), performing an exhaustive recovery and characterization effort and identifying 1,643 micrometeorites (between 100 and 2,000 μm). Approximately 7% of particles are unmelted or scoriaceous, of which 75% are fine‐grained. Among cosmic spherules, 95.6% are silicate‐dominated S‐types, and further subdivided into porphyritic (16.9%), barred olivine (19.9%), cryptocrystalline (51.6%), and vitreous (7.5%). Our (rank)‐size distribution is fit against a power law with a slope of −3.9 (R2 = 0.98) over the size range 200–700 μm. However, the distribution is also bimodal, with peaks centered at ~145 and ~250 μm. Remarkably similar peak positions are observed in the Larkman Nunatak data. These observations suggest that the micrometeorite flux is composed of multiple dust sources with distinct size distributions. In terms of mass, the TAM65 trap contains 1.77 g of extraterrestrial dust in 15 kg of sediment (<5 mm). Upscaling to a global annual estimate gives 1,555 (±753) t/year—consistent with previous micrometeorite abundance estimates and almost identical to the South Pole Water Well estimate (~1,600 t/year), potentially indicating minimal variation in the background cosmic dust flux over the Quaternary. The greatest uncertainty in our mass flux calculation is the accumulation window. A minimum age (0.8 Ma) is robustly inferred from the presence of Australasian microtektites, while the upper age (~2.3 Ma) is loosely constrained based on 10Be exposure dating of glacial surfaces at Roberts Butte (6 km from our sample site).
New Paths for Survivability of Organic Material in the Martian Subsurface
Authors: Montgomery W. 
Published: January 2020

AbstractRecent space missions have identified organics, chlorinated and non‐chlorinated, on Mars. Understanding the origin, current state and reactivity of this carbonaceous material is critical to efforts to detect organic signatures of possible past life on Mars. Environmental effects such as ultraviolet radiation, pressure, diagenesis, aqueous activity, and presence of perchlorates have been assessed previously using analog experiments. To this list, Fox, et al. adds and quantifies the effect of galactic cosmic rays and solar winds on organic material on the surface and in the near subsurface of Mars. Their work, using laboratory analog materials and radiation, shows that the same organic acids, formic and oxalic acid, are produced after exposure equivalent to that over Martian history at depths of less than 5 cm, independent of mineral matrix or starting organic materials. These experiments suggest that planned subsurface exploration using the drill on the Rosalind Franklin Rover (ExoMars) will sample organic material which has not been altered by cosmic rays, although it may have been exposed to other environmental factors such as water or salts.
Tectonic Control on Rapid Late Miocene—Quaternary Incision of the Mekong River Knickzone, Southeast Tibetan Plateau
Authors: Replumaz Anne , San José Malwina , Margirier Audrey , van der Beek Peter , Gautheron Cécile , Leloup Philippe Hervé , Ou Xiong , Kai Cao , Wang Guo‐Can , Zhang Yuan‐Ze , Valla Pierre G. , Balvay Mélanie 
Published: January 2020

ABSTRACTThe incision history of the Three Rivers (Salween, Mekong, and Yangtze) region in the Southeast Tibetan Plateau has been linked to both tectonic and climatic controls. In this study, we report new apatite (U‐Th)/He and fission‐track thermochronology data from the >6,000‐m‐high Kawagebo massif, which forms the edge of the high plateau on the western flank of the steepened knickzone reach of the middle Mekong River valley. Thermal‐history modeling of a thermochronological age‐elevation profile shows rapid cooling since ~1.5 Ma and suggests a mean Quaternary exhumation rate of >1 km/Myr at the valley bottom. The amount of Quaternary exhumation is too high to be caused by fluvial incision alone and requires additional tectonic uplift. Comparing our data from the western flank of the Mekong River valley with published data from the eastern flank shows differential exhumation across the valley in the late Miocene, with the western flank undergoing more exhumation, but relatively uniform exhumation in the Quaternary. We relate rapid exhumation since the late Miocene on the western flank of the Mekong valley and the high topography of the Kawagebo massif to localized tectonic uplift associated with a restraining (left stepping) overstep between the still‐active right‐lateral Parlung and Zhongdian strike‐slip faults. The pattern of river steepness index across the knickzone also indicates that it results from locally focused uplift. Our results demonstrate the importance of detailed thermochronologic studies in this very active region to constrain the complex multiphase tectonic history before invoking any potential climatic forcing of river incision.
On the Impact of Salt Marsh Pioneer Species‐Assemblages on the Emergence of Intertidal Channel Networks
Authors: Bij de Vaate I. , Brückner M. Z. M. , Kleinhans M. G. , Schwarz C. 
Published: February 2020

AbstractTidal marshes play an important role in climate change mitigation through natural coastal protection. The effectiveness of the natural coastal defense by tidal marshes is closely related to their channel network which is in turn greatly influenced by their vegetation cover and shape. Previous research suggests a dual effect of vegetation on marsh topography; stabilizing sediment on the one hand versus promoting erosion and channel incision on the other hand. This study links these effects to different vegetation species,Salicornia procumbens,Spartina anglica, andPuccinellia maritima(further referred to asSalicornia,Spartina, andPuccinellia), by means of a coupled bio‐hydromorphodynamic modeling study. Single species, species‐assemblages, and species shifts were studied, incorporating both species‐specific physical plant properties and spatiotemporal growth strategies. The results indicate the influence of vegetation on the marsh topography to be highly species‐dependent, but also of a very complex nature. Both the presence ofSpartinaandPuccinelliaresulted in significant channel development, whereasSalicorniadid not induce topographic change. The combination of several species promoted or reduced channel development depending on the included species. Species‐shifts linked with climatic changes resulted in increased erosion of the existing channel network potentially reducing the protective capacity of the marsh.
Isocitrate dehydrogenase 2 protects mice from high-fat diet-induced metabolic stress by limiting oxidative damage to the mitochondria from brown adipose tissue
Authors: Lee Jae-Ho , Go Younghoon , Kim Do-Young , Lee Sun Hee , Kim Ok-Hee , Jeon Yong Hyun , Kwon Taeg Kyu , Bae Jae-Hoon , Song Dae-Kyu , Rhyu Im Joo , Lee In-Kyu , Shong Minho , Oh Byung-Chul , Petucci Christopher , Park Jeen-Woo , Osborne Timothy F. , Im Seung-Soon 
Published: February 2020

AbstractIsocitrate dehydrogenase 2 (IDH2) is an NADP+-dependent enzyme that catalyzes the oxidative decarboxylation of isocitrate to α-ketoglutarate in the mitochondrial matrix, and is critical for the production of NADPH to limit the accumulation of mitochondrial reactive oxygen species (ROS). Here, we showed that high-fat diet (HFD) feeding resulted in accelerated weight gain in the IDH2KO mice due to a reduction in whole-body energy expenditure. Moreover, the levels of NADP+, NADPH, NAD+, and NADH were significantly decreased in the brown adipose tissue (BAT) of the HFD-fed IDH2KO animals, accompanied by decreased mitochondrial function and reduced expression of key genes involved in mitochondrial biogenesis, energy expenditure, and ROS resolution. Interestingly, these changes were partially reversed when the antioxidant butylated hydroxyanisole was added to the HFD. These observations reveal a crucial role for IDH2 in limiting ROS-dependent mitochondrial damage when BAT metabolism is normally enhanced to limit weight gain in response to dietary caloric overload.
Autophagy in metabolic syndrome: breaking the wheel by targeting the renin–angiotensin system
Authors: Menikdiwela Kalhara R. , Ramalingam Latha , Rasha Fahmida , Wang Shu , Dufour Jannette M. , Kalupahana Nishan S. , Sunahara Karen K. S. , Martins Joilson O. , Moustaid-Moussa Naima 
Published: February 2020

AbstractMetabolic syndrome (MetS) is a complex, emerging epidemic which disrupts the metabolic homeostasis of several organs, including liver, heart, pancreas, and adipose tissue. While studies have been conducted in these research areas, the pathogenesis and mechanisms of MetS remain debatable. Lines of evidence show that physiological systems, such as the renin–angiotensin system (RAS) and autophagy play vital regulatory roles in MetS. RAS is a pivotal system known for controlling blood pressure and fluid balance, whereas autophagy is involved in the degradation and recycling of cellular components, including proteins. Although RAS is activated in MetS, the interrelationship between RAS and autophagy varies in glucose homeostatic organs and their cross talk is poorly understood. Interestingly, autophagy is attenuated in the liver during MetS, whereas autophagic activity is induced in adipose tissue during MetS, indicating tissue-specific discordant roles. We discuss in vivo and in vitro studies conducted in metabolic tissues and dissect their tissue-specific effects. Moreover, our review will focus on the molecular mechanisms by which autophagy orchestrates MetS and the ways future treatments could target RAS in order to achieve metabolic homeostasis.
α-Linolenic acid but not linolenic acid protects against hypertension: critical role of SIRT3 and autophagic flux
Authors: Li Guohua , Wang Xinpei , Yang Hongyan , Zhang Pengfei , Wu Fangqin , Li Yunchu , Zhou Yingjie , Zhang Xing , Ma Heng , Zhang Wei , Li Jia 
Published: February 2020

AbstractAlthough dietary α-linolenic acid (ALA) or linolenic acid (LA) intake was reported to be epidemiologically associated with a lower prevalence of hypertension, recent clinical trials have yielded conflicting results. Comparable experimental evidence for the roles of these two different fatty acids is still lacking and the underlying mechanisms need to be further elucidated. Our data showed that ALA but not LA supplementation alleviated systolic blood pressure elevation and improved ACh-induced, endothelium-dependent vasodilation in both spontaneously hypertensive rats (SHRs) and AngII-induced hypertensive mice. In addition, SHRs displayed reduced vascular Sirtuin 3 (SIRT3) expression, subsequent superoxide dismutase 2 (SOD2) hyperacetylation and mitochondrial ROS overproduction, all of which were ameliorated by ALA but not LA supplementation. In primary cultured endothelial cells, ALA treatment directly inhibited SIRT3 reduction, SOD2 hyperacetylation, mitochondrial ROS overproduction and alleviated autophagic flux impairment induced by AngII plus TNFα treatment. However, these beneficial effects of ALA were completely blocked by silencing SIRT3. Restoration of autophagic flux by rapamycin also inhibited mitochondrial ROS overproduction in endothelial cells exposed to AngII plus TNFα. More interestingly, SIRT3 KO mice developed severe hypertension in response to a low dose of AngII infusion, while ALA supplementation lost its anti-hypertensive and endothelium-protective effects on these mice. Our findings suggest that ALA but not LA supplementation improves endothelial dysfunction and diminishes experimental hypertension by rescuing SIRT3 impairment to restore autophagic flux and mitochondrial redox balance in endothelial cells.
Locus-specific DNA methylation of Mecp2 promoter leads to autism-like phenotypes in mice
Authors: Lu Zongyang , Liu Zhen , Mao Wei , Wang Xinying , Zheng Xiaoguo , Chen Shanshan , Cao Beibei , Huang Shisheng , Zhang Xuliang , Zhou Tao , Zhang Yu , Huang Xingxu , Sun Qiang , Li Jia-Da 
Published: February 2020

AbstractAutism spectrum disorder (ASD) is a neurodevelopmental disease with a strong heritability, but recent evidence suggests that epigenetic dysregulation may also contribute to the pathogenesis of ASD. Especially, increased methylation at the MECP2 promoter and decreased MECP2 expression were observed in the brains of ASD patients. However, the causative relationship of MECP2 promoter methylation and ASD has not been established. In this study, we achieved locus-specific methylation at the transcription start site (TSS) of Mecp2 in Neuro-2a cells and in mice, using nuclease-deactivated Cas9 (dCas9) fused with DNA methyltransferase catalytic domains, together with five locus-targeting sgRNAs. This locus-specific epigenetic modification led to a reduced Mecp2 expression and a series of behavioral alterations in mice, including reduced social interaction, increased grooming, enhanced anxiety/depression, and poor performance in memory tasks. We further found that specifically increasing the Mecp2 promoter methylation in the hippocampus was sufficient to induce most of the behavioral changes. Our finding therefore demonstrated for the first time the casual relationship between locus-specific DNA methylation and diseases symptoms in vivo, warranting potential therapeutic application of epigenetic editing.
Parents’ motivations, concerns and understanding of genome sequencing: a qualitative interview study
Authors: Lewis Celine , Sanderson Saskia , Hill Melissa , Patch Chris , Searle Beverly , Hunter Amy , Chitty Lyn S. 
Published: January 2020

AbstractThe 100,000 Genomes Project is a hybrid clinical and research project in which patients and parents are offered genome sequencing for cancer and rare and inherited disease diagnosis; all participants receive their main findings and contribute their data for research, and are offered optional secondary findings. Our aim was to explore participating parents’ attitudes towards and understanding of genome sequencing in this hybrid context. We conducted in-depth telephone interviews with 20 parents of children with rare diseases participating in the 100,000 Genomes Project. Parents were positive about contributing to research, although some had needed reassurance about data protections. Although most felt positive about secondary findings, some could not recall or misunderstood key aspects. Some were also concerned about potential emotional impact of results and a few raised concerns about life insurance implications, and the impact of future legal changes. Participants were generally positive about consent appointments, but several raised concerns about ‘information overload’ because of deciding about secondary findings at the same time as about the main diagnostic genome sequencing and data contribution. Additional information resources, particularly online tools, were highlighted as potentially useful ways of supporting the consent process. We conclude that parents offered genome sequencing as part of a national hybrid clinical and research project report many positive attitudes and experiences, but also concerns and misunderstandings. Further research is needed on how best to support informed consent, particularly about secondary findings. Additional resources such as online tools might usefully support future genome sequencing consent processes.
Flickering nanometre-scale disorder in a crystal lattice tracked by plasmonic flare light emission
Authors: Carnegie Cloudy , Urbieta Mattin , Chikkaraddy Rohit , de Nijs Bart , Griffiths Jack , Deacon William M. , Kamp Marlous , Zabala Nerea , Aizpurua Javier , Baumberg Jeremy J. 
Published: February 2020

AbstractThe dynamic restructuring of metal nanoparticle surfaces is known to greatly influence their catalytic, electronic transport, and chemical binding functionalities. Here we show for the first time that non-equilibrium atomic-scale lattice defects can be detected in nanoparticles by purely optical means. These fluctuating states determine interface electronic transport for molecular electronics but because such rearrangements are low energy, measuring their rapid dynamics on single nanostructures by X-rays, electron beams, or tunnelling microscopies, is invasive and damaging. We utilise nano-optics at the sub-5nm scale to reveal rapid (on the millisecond timescale) evolution of defect morphologies on facets of gold nanoparticles on a mirror. Besides dynamic structural information, this highlights fundamental questions about defining bulk plasma frequencies for metals probed at the nanoscale.
Carbon dioxide electroreduction on single-atom nickel decorated carbon membranes with industry compatible current densities
Authors: Yang Hengpan , Lin Qing , Zhang Chao , Yu Xinyao , Cheng Zhong , Li Guodong , Hu Qi , Ren Xiangzhong , Zhang Qianling , Liu Jianhong , He Chuanxin 
Published: January 2020

AbstractCarbon dioxide electroreduction provides a useful source of carbon monoxide, but comparatively few catalysts could be sustained at current densities of industry level. Herein, we construct a high-yield, flexible and self-supported single-atom nickel-decorated porous carbon membrane catalyst. This membrane possesses interconnected nanofibers and hierarchical pores, affording abundant effective nickel single atoms that participate in carbon dioxide reduction. Moreover, the excellent mechanical strength and well-distributed nickel atoms of this membrane combines gas-diffusion and catalyst layers into one architecture. This integrated membrane could be directly used as a gas diffusion electrode to establish an extremely stable three-phase interface for high-performance carbon dioxide electroreduction, producing carbon monoxide with a 308.4 mA cm−2 partial current density and 88% Faradaic efficiency for up to 120 h. We hope this work will provide guidance for the design and application of carbon dioxide electro-catalysts at the potential industrial scale.