bluuebunny/crossref_metadata_2025_split huggingface dataset:
Fingerprints of the protosolar cloud collapse in the Solar System: Refractory inclusions distribution and isotopic anomalies in meteorites
Authors: Pignatale Francesco C. , Jacquet Emmanuel , Chaussidon Marc , Charnoz Sébastien 
Published: October 2020

AbstractIncreasing evidences suggest that the building blocks of Ca-Al-rich inclusions (CAIs) could have formed with the Sun, during the collapse of the parent cloud. However, determination of the relative age of CAIs relies on the homogeneous distribution of their short-lived radionuclide 26Al that is used as a chronometer. Some CAIs show evidence of 26Al/27 Al variation that is independent of decay.We investigate the dynamical and chemical evolution of refractories from the collapsing cloud to their transport in the protoplanetary disk focusing to the predicted isotopic anomalies resulting from 26Al heterogeneities.The interplay between the thermal properties of the dust, the isotopic zoning in the cloud and disk dynamics produce aggregates that resemble chondrites. An abrupt raise of 26Al close the center of the cloud followed by a plateau throughout the cloud best matches the observations. As a consequence, the 26Al -chronometer retains validity from the formation of canonical CAIs onward.
Laboratory investigations aimed at building a database for the interpretation of JWST spectra
Authors: Elisabetta Palumbo Maria , Baratta Giuseppe A. , Fedoseev Gleb , Fulvio Daniele , Scirè Carlotta , Strazzulla Giovanni , Giovanni Urso Riccardo 
Published: October 2020

AbstractThe James Webb Space Telescope (JWST) is expected to be launched in 2021. The JWST’s science instruments will provide high quality spectra acquired in the line of sight to young stellar objects whose interpretation will require a robust database of laboratory data. With this in mind, an experimental work is in progress in the Laboratory for Experimental Astrophysics in Catania to study the profile (shape, width, and peak position) of the main infrared bands of molecular species expected to be present in icy grain mantles. Our study also takes into account the modifications induced on icy samples by low-energy cosmic ray bombardment and by thermal processing. Here we present some recent results on deuterium hydrogen monoxide (HDO), N-bearing species, and carbon dioxide (CO2).
Formation of NH2CHO and CH3CHO upon UV processing of interstellar ice analogs
Authors: Martín-Doménech Rafael , Öberg Karin I. , Rajappan Mahesh 
Published: October 2020

AbstractComplex organic molecules (COMs) may have played a role in the formation of life in the early Earth (Herbst & van Dishoeck (2009)). Here we present the formation of NH2CHO and CH3CHO upon vacuum-ultraviolet (VUV) irradiation of CO:NH3 and CO:CH4 ice mixtures, simulating the UV processing of interstellar ices in the interior of dense clouds. We have found that the conversion from ${\rm{N}}{{\rm{H}}_{\dot 2}}$ radicals to NH2CHO is 4–15 times higer than that from ${\rm{N}}{{\rm{H}}_{\dot 3}}$ to CH3CHO, probably due to the competing formation of larger hydrocarbons in the latter case.
Laboratory experiments on cosmic dust and ices
Authors: Jäger Cornelia , Potapov Alexey , Rouillé Gaël , Henning Thomas 
Published: October 2020

AbstractThe existence of cosmic dust is attested by the interstellar extinction and polarization, IR emission and absorption spectra, and elemental depletion patterns. Dust grains are efficiently processed or even destroyed in shocks, molecular clouds, or protoplanetary disks. A considerable amount of dust has to be re-formed in the ISM. In various astrophysical environments, dust grains are covered by molecular ices and therefore contribute or catalytically influence the chemical reactions in these layers. Laboratory experiments are desperately required to understand the evolution of grains and grain/ice mixtures in molecular clouds and early planetary disks. This review considers recent progress in laboratory approaches to dust/ice experiments.
White-dwarf asteroseismology: An update
Authors: Córsico Alejandro H. 
Published: October 2020

AbstractThe vast majority of stars that populate the Universe will end their evolution as white-dwarf stars. Applications of white dwarfs include cosmochronology, evolution of planetary systems, and also as laboratories to study non-standard physics and crystallization. In addition to the knowledge of their surface properties from spectroscopy combined with model atmospheres, the global pulsations that they exhibit during several phases of their evolution allow spying on the deep interior of these stars. Indeed, by means of asteroseismology, an approach based on the comparison between the observed pulsation periods of variable white dwarfs and the periods predicted by representative theoretical models, we can infer details of the internal chemical stratification, the total mass, and even the stellar rotation profile and strength of magnetic fields. In this article, we review the current state of the area, emphasizing the latest findings provided by space-mission data.
Convection in common envelopes and the formation of double white dwarfs
Authors: Wilson E. C. , Nordhaus J. 
Published: October 2020

AbstractFormation of close double white dwarfs likely requires the initial binary system to evolve through two successive common envelope (CE) phases. A prominent method for describing CE outcomes involves defining an ejection efficiency, αeff, which quantifies the fraction of orbital energy available to unbind the envelope. Reproducing observed post-CE orbital parameters has proven difficult for numerical simulations, as the companion’s decaying orbit fails to eject the envelope. The ejection failure seen in numerical simulations may be resolved with a proper treatment of convection, whereby the binary orbit shrinks before energy can drive ejection. Where the orbital decay timescale exceeds the convective transport timescale, the energy released during inspiral is carried to the stellar surface and radiated away. By including convection, we produce sub-day post-CE orbital periods, a result consistent with observations. We comment on the effects of convection for the population of double white dwarfs that evolve through two CEs.
Validation of asteroseismic fitting with the new white dwarf evolution code
Authors: Kim Agnès 
Published: October 2020

AbstractThe new version of the White Dwarf Evolution Code (Bischoff-Kim & Montgomery 2018) overcomes limitations of earlier versions by utilizing MESA modules for the equations of state and opacities, now allowing regions of the model with a mix of helium, carbon, and oxygen. This single improvement allows us to almost exactly replicate models output by other stellar evolution codes. Armed with this new capability, we use as a star to fit, a hydrogen atmosphere white dwarf model from the La Plata group (using the LPCODE). We present results of fitting different subsets of periods for that model. This allows us some validation of our fitting methods, knowing exactly what properties we should be recovering in our best fit model.
Compact quintuple notched-band UWB BPF with high selectivity and wide bandwidth
Authors: Bai Lei , Zhuang Yiqi , Zeng Zhibin 
Published: October 2020

AbstractIn this paper, a compact quintuple notched-band ultra-wideband bandpass filter with high selectivity and wide bandwidth is proposed. The filter adopts an approximate closed-loop C-shaped stepped impedance resonator to generate triple notched bands, and uses Hilbert fractal curve slit and L-shaped resonator to create single notched band, respectively. Multiple notched-band are centered at 5.29, 6.61, 7.92, 8.95, and 9.93 GHz to eliminate undesired interference from coexisting wireless services of WLAN, C-band, and X-band. Additionally, two transmission zeros are introduced to enhance the sharp skirt selectivity up to 0.944. This filter could exhibit high sharp selectivity and wider bandwidth simultaneously. The filter is fabricated on a RT/Duroid 5880 substrate (ɛr = 2.2 and thickness = 0.787 mm) and measured to verify the simulation results. Both simulation and measurement are in well agreement, showing the good performance of the filter.
Glyphosate-induced hormesis: impact on seedling growth and reproductive potential of common sowthistle (Sonchus oleraceus)
Authors: Mobli Ahmadreza , Matloob Amar , Chauhan Bhagirath Singh 
Published: October 2020

AbstractIn Australia, glyphosate is widely used in glyphosate-tolerant crops and fallows to control weeds such as common sowthistle (Sonchus oleraceus L.). It has been hypothesized that glyphosate at sublethal doses, as a consequence of herbicide drift, may have a stimulatory effect on S. oleraceus growth. In 2017, pot trials were conducted to evaluate the effect of low doses of glyphosate on growth and seed production of this weed at the Weed Science Screenhouse Facility at the University of Queensland, Australia. At the 4- to 5-leaf stage (3-wk-old rosette), plants were treated with low doses of glyphosate (0 [control], 5, 10, 20, 40, 80, and 800 g ae ha−1), and their responses were recorded until plant maturity. The study was repeated after completion of the first experimental run. An additional glyphosate dose (2.5 g ha−1) was added in the second run. The low doses of glyphosate (<40 g ha−1) caused a significant increase in S. oleraceus plant height and number of leaves compared with the no-glyphosate treatment. The highest stimulatory effect was observed at 5 g ha−1. At 5 g ha−1 glyphosate, S. oleraceus seed production increased by 154% and 101% in the first and second experimental runs, respectively, compared with the no-glyphosate treatment. The results of this study suggest that the sublethal doses of glyphosate produced hormetic effects on growth and seed production of S. oleraceus that changed the dynamics of weed–crop competition.
Dust Impacts of Rapid Agricultural Expansion on the Great Plains
Authors: Lambert Andrew , Hallar A. Gannet , Garcia Maria , Strong Courtenay , Andrews Elisabeth , Hand Jenny L. 
Published: October 2020

AbstractClimate change and land use are altering the landscape of the U.S. Great Plains, producing increases in windblown dust. These increases are investigated by combining coarse mode aerosol observations from the Moderate Resolution Imaging Spectroradiometer (MODIS) sensor in addition to the Aerosol Robotic Network (AERONET) and Interagency Monitoring of Protected Visual Environments (IMPROVE) aerosol monitoring networks. Increasing trends of up to 5%/year in MODIS aerosol optical depth for dust observations are observed throughout the Great Plains (2000–2018). Cropland coverage has increased 5–10% over the majority of the Great Plains (2008–2018), and positive monthly trends in IMPROVE (1988–2018) and AERONET (1995–2018) coarse mode 90th percentile observations coincide with planting and harvesting seasons of predominant crops. Presently, results suggest increased dust due to agricultural expansion is negatively influencing human health and visibility in the Great Plains. Furthermore, results foreshadow a future where desertification becomes an increasing risk in the Great Plains.
3‐D Tomographic Reconstruction of SED Plume During 17 March 2013 Storm
Authors: Zhai Changzhi , Lu Gang , Yao Yibin , Wang Wenbin , Zhang Shunrong , Liu Jing , Peng Wenjie , Kong Jian , Chen Jun 
Published: October 2020

AbstractThe three‐dimensional computerized ionospheric tomography (3DCIT) technique is used to reconstruct the spatial distribution of storm‐enhanced density (SED) based on the global positioning system total electron content measurements over the North American area during the 17 March 2013 storm. The reconstruction results are carefully validated with observations from three ionosonde stations, the constellation observing system for meteorology, ionosphere, and climate (COSMIC) radio occultations, and the Millstone Hill incoherent scatter radar. The electron density profiles from the 3DCIT reconstruction show a good agreement with the ionosonde and COSMIC electron density profiles. The 3DCIT‐derived electron density difference between the storm day of 17 March and the quiet day of 16 March also captures the similar SED plume signature that was observed by the Millstone Hill incoherent scatter radar. The 3DCIT reconstruction allows us for the first time to unveil the 3‐D configuration of the SED plume and its spatiotemporal evolution. It was found that the SED plume first appeared around 400 km and then expanded downward to ~300 km as well as upward to ~500 km over the course of a 3‐hr period from 19 to 22 UT on 17 March. Our study also showed that the density enhancement within the SED plume occurred mostly above the storm time F layer peak height.
Gravity and Pressure‐Gradient Currents Using Ionospheric Electron Density Measurements From COSMIC Satellites
Authors: Sreelakshmi J. , Vichare Geeta 
Published: October 2020

AbstractThe gravity‐driven and pressure‐gradient currents coexist in the ionosphere, and their effects are significant in there, rather than at the outside of the ionosphere; and can be important while studying the ionospheric currents using low‐Earth‐orbiting (LEO) satellite measurements. Maute and Richmond (2017, https://doi.org/10.1002/2017JA024841) (MR17) have demonstrated that above the F region peak, directions of these two coexisting currents are opposite and the net magnetic effects along the ambient magnetic field are nonsignificant. In the view of the diamagnetic corrections being applied to the LEO magnetic field measurements to account for the pressure‐gradient currents, it is imperative to examine the proposition of MR17. In the present paper, we have estimated the gravity and pressure‐gradient currents, using altitude profiles of electron density obtained from the Constellation Observing System for Meteorology, Ionosphere, and Climate (COSMIC)‐1 satellite cluster. In order to get the latitudinal profiles of magnetic field variations at a fixed local time (LT) using COSMIC data, it is required to combine either different days at a fixed longitude or all the longitudes on a fixed day, thus compromising with either days or longitudes. It is found that the net magnetic field is significant in the low‐latitude region, which increases with solar flux and decreases with altitude. The magnetic field effects show strong LT dependence and are significant in the noon to evening sector. The comparison of the present estimates with the diamagnetic corrections emphasizes that correcting for only one current can introduce unviable errors and thus supports the suggestion of MR17.
Interannual Salinity Variability Associated With the Central Pacific and Eastern Pacific El Niños in the Tropical Pacific
Authors: Zhi Hai , Zhang Rong‐Hua , Lin Pengfei , Yu Peng , Zhou Guanghui , Shi Shiwei 
Published: October 2020

AbstractOcean reanalysis products and observations are used to analyze the differences between the two types of El Niño in terms of interannual salinity variability in the tropical Pacific; a budget analysis for mixed layer (ML) salinity (MLS) is performed in the region. The center of negative MLS anomalies associated with the central Pacific (CP) El Niño tends to move further westward in winter along the equator, as compared with the eastern Pacific (EP) El Niño. The oscillation period with the EP El Niño is found to be approximately 10 years, longer than that with the CP El Niño (approximately 6–8 years). Our budget analyses further reveal that surface advection, surface forcing, and subsurface effect are the three main contributors to ML tendency of interannual salinity anomalies, which are regionally dependent. In the eastern edge of the warm pool (WP), surface advection makes a larger contribution (about 40–60%) to the MLS budget, and subsurface effect (about 20%) and surface forcing (about 20–40%) are relatively smaller. The subsurface effects on the MLS tendency tend to compensate for the imbalance induced by the surface forcing and advection: A weakened MLS tendency occurs with the CP El Niño, whereas an enhanced MLS tendency occurs with the EP El Niño, respectively. The MLS tendency leads the Niño3.4 SST by 8–10 months for the EP El Niño, whereas there is no such apparent lead/lag relationship for the CP El Niño. It is demonstrated that the relationships between the interannual sea surface temperature (SST) variability and MLS budget terms can be a clear indicator to distinguish the two types of El Niño.
Epigenetic regulation of VENTXP1 suppresses tumor proliferation via miR-205-5p/ANKRD2/NF-kB signaling in head and neck squamous cell carcinoma
Authors: Zhang Li Ming , Su Li Xin , Hu Jing Zhou , Wang De Ming , Ju Hou Yu , Li Xiao , Han Yi Feng , Xia Wei Ya , Guo Wei , Ren Guo Xin , Fan Xin Dong 
Published: October 2020

AbstractAn increasing number of studies have shown that long noncoding RNAs (lncRNAs) play important roles in tumor development and progression. However, their involvement in head and neck squamous cell carcinoma (HNSCC) remains largely unknown. Epigenetic regulation is one major mechanism utilized by cancer cells to control lncRNA expression. We identified that lncRNA VENTXP1 was epigenetically silenced in multiple cancer types, and its lower expression was correlated with poorer survival in HNSCC patients. Through in silico analysis and experimental validation, we identified miR-205-5p and its direct interacting partner of VENTXP1, which regulates HNSCC cell proliferation and tumorigenicity. Using RNA-seq and differential gene expression analysis, we further identified ANKRD2 as a miR-205-5p target, which plays an essential role in modulating NF-kB signaling. These findings suggest that VENTXP1 inhibits tumor growth via suppressing miR-205-5p/ANKRD2-mediated NF-kB signaling in HNSCC. Thus, pharmaceutical targeting of DNA methylation to restore VENTXP1 expression might constitute a therapeutic strategy for HNSCC.
Mitochondrial ClpP serine protease-biological function and emerging target for cancer therapy
Authors: Nouri Kazem , Feng Yue , Schimmer Aaron D. 
Published: October 2020

AbstractMitochondrial ClpP is a serine protease located in the mitochondrial matrix. This protease participates in mitochondrial protein quality control by degrading misfolded or damaged proteins, thus maintaining normal metabolic function. Mitochondrial ClpP is a stable heptamer ring with peptidase activity that forms a multimeric complex with the ATP-dependent unfoldase ClpX (ClpXP) leading to proteolytic activity. Emerging evidence demonstrates that ClpXP is over-expressed in hematologic malignancies and solid tumors and is necessary for the viability of a subset of tumors. In addition, both inhibition and hyperactivation of ClpXP leads to impaired respiratory chain activity and causes cell death in cancer cells. Therefore, targeting mitochondrial ClpXP could be a novel therapeutic strategy for the treatment of malignancy. Here, we review the structure and function of mitochondrial ClpXP as well as strategies to target this enzyme complex as a novel therapeutic approach for malignancy.
Expression of leukotriene B4 receptor 1 defines functionally distinct DCs that control allergic skin inflammation
Authors: Koga Tomoaki , Sasaki Fumiyuki , Saeki Kazuko , Tsuchiya Soken , Okuno Toshiaki , Ohba Mai , Ichiki Takako , Iwamoto Satoshi , Uzawa Hirotsugu , Kitajima Keiko , Meno Chikara , Nakamura Eri , Tada Norihiro , Fukui Yoshinori , Kikuta Junichi , Ishii Masaru , Sugimoto Yukihiko , Nakao Mitsuyoshi , Yokomizo Takehiko 
Published: October 2020

AbstractLeukotriene B4 (LTB4) receptor 1 (BLT1) is a chemotactic G protein-coupled receptor expressed by leukocytes, such as granulocytes, macrophages, and activated T cells. Although there is growing evidence that BLT1 plays crucial roles in immune responses, its role in dendritic cells remains largely unknown. Here, we identified novel DC subsets defined by the expression of BLT1, namely, BLT1hi and BLT1lo DCs. We also found that BLT1hi and BLT1lo DCs differentially migrated toward LTB4 and CCL21, a lymph node-homing chemoattractant, respectively. By generating LTB4-producing enzyme LTA4H knockout mice and CD11c promoter-driven Cre recombinase-expressing BLT1 conditional knockout (BLT1 cKO) mice, we showed that the migration of BLT1hi DCs exacerbated allergic contact dermatitis. Comprehensive transcriptome analysis revealed that BLT1hi DCs preferentially induced Th1 differentiation by upregulating IL-12p35 expression, whereas BLT1lo DCs accelerated T cell proliferation by producing IL-2. Collectively, the data reveal an unexpected role for BLT1 as a novel DC subset marker and provide novel insights into the role of the LTB4-BLT1 axis in the spatiotemporal regulation of distinct DC subsets.
Quantum transport evidence of Weyl fermions in an epitaxial ferromagnetic oxide
Authors: Takiguchi Kosuke , Wakabayashi Yuki K. , Irie Hiroshi , Krockenberger Yoshiharu , Otsuka Takuma , Sawada Hiroshi , Nikolaev Sergey A. , Das Hena , Tanaka Masaaki , Taniyasu Yoshitaka , Yamamoto Hideki 
Published: October 2020

AbstractMagnetic Weyl semimetals have novel transport phenomena related to pairs of Weyl nodes in the band structure. Although the existence of Weyl fermions is expected in various oxides, the evidence of Weyl fermions in oxide materials remains elusive. Here we show direct quantum transport evidence of Weyl fermions in an epitaxial 4d ferromagnetic oxide SrRuO3. We employ machine-learning-assisted molecular beam epitaxy to synthesize SrRuO3 films whose quality is sufficiently high to probe their intrinsic transport properties. Experimental observation of the five transport signatures of Weyl fermions—the linear positive magnetoresistance, chiral-anomaly-induced negative magnetoresistance, π phase shift in a quantum oscillation, light cyclotron mass, and high quantum mobility of about 10,000 cm2V−1s−1—combined with first-principles electronic structure calculations establishes SrRuO3 as a magnetic Weyl semimetal. We also clarify the disorder dependence of the transport of the Weyl fermions, which gives a clear guideline for accessing the topologically nontrivial transport phenomena.
Concepts of extracellular matrix remodelling in tumour progression and metastasis
Authors: Winkler Juliane , Abisoye-Ogunniyan Abisola , Metcalf Kevin J. , Werb Zena 
Published: October 2020

AbstractTissues are dynamically shaped by bidirectional communication between resident cells and the extracellular matrix (ECM) through cell-matrix interactions and ECM remodelling. Tumours leverage ECM remodelling to create a microenvironment that promotes tumourigenesis and metastasis. In this review, we focus on how tumour and tumour-associated stromal cells deposit, biochemically and biophysically modify, and degrade tumour-associated ECM. These tumour-driven changes support tumour growth, increase migration of tumour cells, and remodel the ECM in distant organs to allow for metastatic progression. A better understanding of the underlying mechanisms of tumourigenic ECM remodelling is crucial for developing therapeutic treatments for patients.