bluuebunny/crossref_metadata_2025_split huggingface dataset:
Correlations Between the Thermosphere's Semiannual Density Variations and Infrared Emissions Measured With the SABER Instrument
Authors: Weimer D. R. , Mlynczak M. G. , Emmert J. T. , Doornbos E. , Sutton E. K. , Hunt L. A. 
Published: October 2018

AbstractThis paper presents measurements of the amplitudes and timings of the combined, annual, and semiannual variations of thermospheric neutral density, and a comparison of these density variations with measurements of the infrared emissions from carbon dioxide and nitric oxide in the thermosphere. The density values were obtained from measurements of the atmospheric drag experienced by the Challenging Minisatellite Payload, Gravity Recovery and Climate Experiment A, Gravity field and Ocean Circulation Explorer, and three Swarm satellites, while the optical emissions were measured with the Sounding of the Atmosphere using Broadband Emission Radiometry (SABER) instrument on the Thermosphere Ionosphere Mesosphere Energetics and Dynamics satellite. These data span a time period of 16 years. A database containing global average densities that were derived from the orbits of about 5,000 objects (Emmert, 2009, https://doi.org/10.1029/2009JA014102, 2015b, https://doi.org/10.1002/2015JA021047) was employed for calibrating these density data. A comparison with the NRLMSISE‐00 model was used to derive measurements of how much the density changes over time due to these seasonal variations. It is found that the seasonal density oscillations have significant variations in amplitude and timing. In order to test the practicality of using optical emissions as a monitoring tool, the SABER data were fit to the measured variations. Even the most simple fit that used only filtered carbon dioxide emissions had good correlations with the measured oscillations. However, the density oscillations were also well predicted by a simple Fourier series, contrary to original expectations. Nevertheless, measurements of the optical emissions from the thermosphere are expected to have a role in future understanding and prediction of the semiannual variations.
Arctic‐Wide Sea Ice Thickness Estimates From Combining Satellite Remote Sensing Data and a Dynamic Ice‐Ocean Model with Data Assimilation During the CryoSat‐2 Period
Authors: Mu Longjiang , Losch Martin , Yang Qinghua , Ricker Robert , Losa Svetlana N. , Nerger Lars 
Published: October 2018

AbstractExploiting the complementary character of CryoSat‐2 and Soil Moisture and Ocean Salinity satellite sea ice thickness products, daily Arctic sea ice thickness estimates from October 2010 to December 2016 are generated by an Arctic regional ice‐ocean model with satellite thickness assimilated. The assimilation is performed by a Local Error Subspace Transform Kalman filter coded in the Parallel Data Assimilation Framework. The new estimates can be generally thought of as combined model and satellite thickness (CMST). It combines the skill of satellite thickness assimilation in the freezing season with the model skill in the melting season, when neither CryoSat‐2 nor Soil Moisture and Ocean Salinity sea ice thickness is available. Comparisons with in situ observations from the Beaufort Gyre Exploration Project, Ice Mass Balance Buoys, and the NASA Operation IceBridge demonstrate that CMST reproduces most of the observed temporal and spatial variations. Results also show that CMST compares favorably to the Pan‐Arctic Ice‐Ocean Modeling and Assimilation System product and even appears to correct known thickness biases in the Pan‐Arctic Ice‐Ocean Modeling and Assimilation System. Due to imperfect parameterizations in the sea ice model and satellite thickness retrievals, CMST does not reproduce the heavily deformed and ridged sea ice along the northern coast of the Canadian Arctic Archipelago and Greenland. With the new Arctic sea ice thickness estimates sea ice volume changes in recent years can be further assessed.
The Simulation of East Asian Summer Monsoon Precipitation With a Regional Ocean‐Atmosphere Coupled Model
Authors: Dai Yongjiu , Li Haiqin , Sun Liqiang 
Published: October 2018

AbstractA fully coupled regional ocean‐atmosphere model was used to simulate the East Asian summer monsoon (EASM) precipitation. This coupled regional climate modeling system consists of the Regional Spectral Model (RSM) for the atmosphere and the Regional Ocean Modeling System for the ocean. The ocean and atmosphere share the same horizontal grid resolution. The coupled model is forced by the National Centers for Environmental Prediction‐Department of Energy (R‐2) global atmospheric reanalysis and Simplified Ocean Data Assimilation global oceanic reanalysis through the lateral boundary. This study examines EASM surface oceanic state and precipitation variability from a 22‐year (1984–2005) integration with a horizontal resolution of 40 km. The coupled model captures the features of observed sea surface temperature (SST), sea surface height, and ocean surface currents. Compared with the control run of the uncoupled RSM forced with observed SSTs, the coupled model shows more realistic simulation of the EASM precipitation climatology. The coupled model also improves the simulation of precipitation variability at both interannual and intraseasonal scales. It is the coupled model, not the uncoupled RSM, represents the observed SST‐precipitation and SST‐evaporation relationships. This study indicates that the ocean‐atmosphere coupling is essential for model simulations of the EASM precipitation.
Model Resolution Sensitivity of the Simulation of North Atlantic Oscillation Teleconnections to Precipitation Extremes
Authors: Mahajan Salil , Evans Katherine J. , Branstetter Marcia L. , Tang Qi 
Published: October 2018

AbstractWe evaluate a high‐resolution (0.25°), four‐member ensemble simulation of the global climate (1979–2005) with the U.S. Department of Energy's Energy Exascale Earth System Model v0.3—forced with observed ocean surface temperatures and sea ice extent—for its ability to represent the North Atlantic Oscillation (NAO) teleconnections to winter precipitation extremes over western Europe. As compared to the low‐resolution model (1°), it simulates a stronger impact of NAO on daily precipitation extremes over the western slopes of mountain ranges over southwestern Norway, northwestern United Kingdom, and the Western Balkan states. Precipitation extremes and their linear relationship with NAO are quantified using the generalized extreme value distribution. NAO‐dependent large‐scale (stratiform) precipitation intensity strengthens in the high‐resolution model on seasonal time scales and plays a dominant role during simulated daily precipitation extremes. Improvements in the high‐resolution model over these varied‐topography regions largely appear to be due to finer resolved scales of motion that amplify NAO‐dependent seasonal vertical moisture fluxes and enhance stable condensation. However, the high‐resolution model simulates a weaker than observed impact of NAO on extratropical cyclone activity and total precipitable water, generally underperforming the low‐resolution model These effects possibly offset the impact of enhanced vertical moisture fluxes on NAO‐dependent precipitation extremes in the high‐resolution model in these regions. Over the southwestern Iberian peninsula, the high‐resolution model underperforms the low‐resolution model simulating weaker than observed impact of NAO on precipitation extremes. This appears to be due to the reduction in total precipitable water despite an increase in NAO‐dependent extratropical activity there.
The Linkage Between Arctic Sea Ice and Midlatitude Weather: In the Perspective of Energy
Authors: Gu Sen , Zhang Yang , Wu Qigang , Yang Xiu‐Qun 
Published: October 2018

AbstractThe influence of Arctic changes on the weather in the highly populated midlatitude is a controversial topic with little agreements regarding its existence or its mechanism. Utilizing eddy energy as metrics of circulation and temperature fluctuations with weather patterns, this study highlights the robust relationship between the early autumn Arctic sea ice and the wintertime transient activities over northern Eurasia on interannual time scale, by comparing groups of statistical and diagnostical results. With the reduction of sea ice in early autumn in Barents, Kara, Laptev, and East Siberia Seas, the atmosphere over those polar regions exhibits significant increase in eddy energy in the following winter. In the adjacent Eurasia, the wintertime synoptic eddy energy decreases, while the low‐frequency eddy energy, corresponding to persistent weather patterns, exhibits evident and dominant increase. The enhanced southward energy propagation of low‐frequency waves from the polar region to the north of middle‐to‐east Asia suggests a mechanism for the Arctic‐midlatitude linkage, indicating that Arctic sea ice could be a source of predictability for both extended‐range and subseasonal to seasonal forecasts.
Polar Jet Associated Circulation Triggered a Saharan Cyclone and Derived the Poleward Transport of the African Dust Generated by the Cyclone
Authors: Francis Diana , Eayrs Clare , Chaboureau Jean‐Pierre , Mote Thomas , Holland David M. 
Published: October 2018

AbstractIn this study, we identify a new mechanism by which dust aerosols travel over long distances across the eastern side of the North Atlantic Ocean toward the Arctic. The meandering polar jet was at the origin of both dust emission through cyclogenesis over Northwest Africa and poleward transport of the uplifted dust toward the Arctic, through cut‐off circulation. The dust emission was associated with an intense Saharan cyclone that formed over Northwest Africa in early April 2011. The formation of the cyclone was caused by the intrusion into subtropics, of a high‐latitude‐upper‐level trough, linked to the meandering polar jet. The trough initiated cyclogenesis over Northwest Africa after orographic blocking by the Anti‐Atlas Mountains. The still meandering polar jet led to the formation of a cut‐off low further south with which the Saharan dust‐cyclone merged 2 days later and moved northward with the main stream. Beside satellite observations, a simulation at high resolution was performed using the prognostic‐dust permitting model MesoNH. The total dust load carried during this event to areas located north of 40 N was estimated by the model to be 38 Tg and dust deposition was estimated to be 1.3 Tg. The Saharan dust reaching Greenland was accompanied by warm and moist air masses that caused a rise in surface temperature of about 10C for more than 3 consecutive days over the southeastern Greenland. Ice melt over this area of Greenland was detected in the brightness temperature observations.
Nitrogen Oxides Emissions, Chemistry, Deposition, and Export Over the Northeast United States During the WINTER Aircraft Campaign
Authors: Jaeglé L. , Shah V. , Thornton J. A. , Lopez‐Hilfiker F. D. , Lee B. H. , McDuffie E. E. , Fibiger D. , Brown S. S. , Veres P. , Sparks T. L. , Ebben C. J. , Wooldridge P. J. , Kenagy H. S. , Cohen R. C. , Weinheimer A. J. , Campos T. L. , Montzka D. D. , Digangi J. P. , Wolfe G. M. , Hanisco T. , Schroder J. C. , Campuzano‐Jost P. , Day D. A. , Jimenez J. L. , Sullivan A. P. , Guo H. , Weber R. J. 
Published: October 2018

AbstractWe examine the distribution and fate of nitrogen oxides (NOx) in the lower troposphere over the Northeast United States (NE US) using aircraft observations from the Wintertime INvestigation of Transport, Emissions, and Reactivity (WINTER) campaign in February–March 2015, as well as the GEOS‐Chem chemical transport model and concurrent ground‐based observations. We find that the National Emission Inventory from the U.S. Environmental Protection Agency is consistent with WINTER observations of total reactive nitrogen (TNOy) to within 10% on average, in contrast to the significant overestimate reported in past studies under warmer conditions. Updates to the dry deposition scheme and dinitrogen pentoxide (N2O5) reactive uptake probability, ɣ(N2O5), result in an improved simulation of gas‐phase nitric acid (HNO3) and submicron particulate nitrate (pNO3−), reducing the longstanding factor of 2–3 overestimate in wintertime HNO3 + pNO3− to a 50% positive bias. We find a NOx lifetime against chemical loss and deposition of 22 hr in the lower troposphere over the NE US. Chemical loss of NOx is dominated by N2O5 hydrolysis (58% of loss) and reaction with OH (33%), while 7% of NOx leads to the production of organic nitrates. Wet and dry deposition account for 55% and 45% of TNOy deposition over land, respectively. We estimate that 42% of the NOx emitted is exported from the NE US boundary layer during winter, mostly in the form of HNO3 + pNO3− (40%) and NOx (38%).
Latitudinal Double‐Peak Structure of Stationary Planetary Wave 1 in the Austral Winter Middle Atmosphere and Its Possible Generation Mechanism
Authors: Lu Xian , Wu Haonan , Oberheide Jens , Liu Han‐Li , McInerney Joseph M. 
Published: October 2018

AbstractWe report a hitherto unknown latitudinal double‐peak structure in the amplitude of stationary planetary wave 1 (SPW1) geopotential height in the stratosphere and lower mesosphere during austral winter. The primary peak is located at 60–70°S and 30–40 km, and the secondary peak is at 30–50°S and 40–60 km. According to 36 years (1981–2016) of the Modern‐Era Retrospective analysis for Research and Applications, version 2, reanalysis data, the double‐peak structure occurs with frequencies of ~61%, 97%, 53%, and 25% in May, June, July and August, respectively, while it rarely exists in other seasons. Significant downward Eliassen‐Palm fluxes suggestive of downward‐propagating waves are often found above the secondary peak, and phase progressions show opposite directions on its two sides. From the free‐running Whole Atmosphere Community Climate Model and linear mechanistic model simulations, the secondary peak is likely generated by the interference of primary upward‐ and secondary downward‐propagating SPW1 excited in situ by gravity wave forcing in the upper mesosphere. The strengths of the primary and secondary waves need to be comparable to form an effective interference pattern, which may explain the missing double‐peak feature in boreal winter as the primary waves are too dominant. Summer‐to‐winter interhemispheric wave coupling is identified in the austral midwinter and appears to originate from the secondary SPW1 generated in the summer hemisphere. Since the double‐peak structure of SPW1 is sensitive to the mean wind, wave‐mean flow, and wave‐wave interactions, this study provides a reference for general circulation and mechanistic models to simulate the middle atmosphere wave dynamics in austral winter.
BAP1 acts as a tumor suppressor in intrahepatic cholangiocarcinoma by modulating the ERK1/2 and JNK/c-Jun pathways
Authors: Chen Xu-Xiao , Yin Yue , Cheng Jian-Wen , Huang Ao , Hu Bo , Zhang Xin , Sun Yun-Fan , Wang Jian , Wang Yu-Peng , Ji Yuan , Qiu Shuang-Jian , Fan Jia , Zhou Jian , Yang Xin-Rong 
Published: October 2018

AbstractCurrent therapeutic options for intrahepatic cholangiocarcinoma (ICC) are very limited, which is largely attributed to poor understanding of molecular pathogenesis of ICC. Breast cancer type 1 susceptibility protein-associated protein-1 (BAP1) has been reported to be a broad-spectrum tumor suppressor in many tumor types, yet its role in ICC remains unknown. The aim of this study was to investigate the clinical implications and biological function of BAP1 in ICC. Our results showed that the messenger RNA and protein levels of BAP1 were significantly downregulated in ICC versus paired non-tumor tissues. Overexpression of wild-type but not mutant BAP1 significantly suppressed ICC cell proliferation, cell cycle progression, and invasion in vitro, as well as tumor progression in vivo. Conversely, knockdown of BAP1 yielded opposing effects. Mechanistically, BAP1 functioned as a tumor suppressor in ICC by inhibiting the extracellular signal-regulated kinase 1/2 and c-Jun N-terminal kinase/c-Jun pathways, and this function was abolished by inactivating mutations. Clinically, low BAP1 expression was positively correlated with aggressive tumor characteristics, such as larger tumor size, presence of lymphatic metastasis, and advanced tumor node metastasis stage. Survival analysis revealed that low BAP1 expression was significantly and independently associated with poor overall survival and relapse-free survival after curative surgery. In conclusion, BAP1 is a putative tumor suppressor of ICC, and may serve as a valuable prognostic biomarker as well as potential therapeutic target for ICC.
Comparison of breast cancer metastasis models reveals a possible mechanism of tumor aggressiveness
Authors: Pillar Nir , Polsky Avital Luba , Weissglas-Volkov Daphna , Shomron Noam 
Published: October 2018

AbstractIn breast cancer patients, the lungs are among the first sites of cancer metastasis, and in nearly one quarter of metastatic patients, the exclusive first event. Two common mouse models mimic breast cancer lung colonization and distal metastasis: an orthotopic model and intravenous (IV) cell injections. Gene expression analysis of pulmonary lesions from these two methods demonstrated high inter-model resemblance. However, microRNA (miRNA) expression profiles were not compared. In this study, we compared the overall miRNA expression profiles (miRNome) of the orthotopic and IV breast cancer metastasis models and identified significant miRNome changes between the two models. Overexpression of the most significant candidate, miR-96 or downregulation of its validated gene-target, ABCE1 reduced cancer cells 2D/3D cell movement and proliferation in vitro, and abated tumor growth and metastasis formation in vivo. Human data analysis further strengthened miR-96/ABCE1 role in breast cancer tumor aggression. Taken together, our results indicate that IV- and orthotopic models differ by their miRNome. Specifically in our study, breast cancer aggressiveness was dictated by miR-96 regulating ABCE1. Overall, miRNome analysis of various metastatic cancer models may lead to the identification of candidate genes critical to metastasis development.
Diosgenin promotes antitumor immunity and PD-1 antibody efficacy against melanoma by regulating intestinal microbiota
Authors: Dong Mengxue , Meng Zhefeng , Kuerban Kudelaidi , Qi Feilong , Liu Jiayang , Wei Yuxi , Wang Qian , Jiang Shanshan , Feng Meiqing , Ye Li 
Published: October 2018

AbstractDiosgenin, a natural steroidal saponin, can exert antitumor effect by regulating immune function and improving intestinal microbiota. The response to anti-PD-1 immunotherapy is associated with intestinal microbiota and effector T cells in tumor microenvironment. We hypothesize that the modulation of diosgenin on intestinal microbiota can facilitate antitumor immunity and the therapeutic efficacy of PD-1 antibody. In melanoma-bearing C57BL/6 mice, we observed that the anti-melanoma effect of diosgenin relied more on antitumor immunity than direct tumor inhibition activity evidenced by obvious CD4+/CD8+ T-cell infiltration and IFN-γ expression in tumor tissues, and it could improve the compositions of intestinal microbiota. Antibiotics impaired the therapeutic efficacy and immunity responses of diosgenin through disturbing intestinal microbiota, indicating the importance of intestinal microbiota in diosgenin’s in vivo antitumor activity. More importantly, the combined administration of PD-1 antibody with diosgenin aggravated the tumor necrosis and apoptosis by eliciting augmented T-cell responses. Taken together, diosgenin can be used as a microecological regulator to induce antitumor immunity and improve the efficacy of immune checkpoint antibody, making it more suitable for the treatment of malignant tumors.
Increasing G9a automethylation sensitizes B acute lymphoblastic leukemia cells to glucocorticoid-induced death
Authors: Poulard Coralie , Baulu Estelle , Lee Brian H. , Pufall Miles A. , Stallcup Michael R. 
Published: October 2018

AbstractSynthetic glucocorticoids (GCs) are used to treat lymphoid cancers, but many patients develop resistance to treatment, especially to GC. By identifying genes that influence sensitivity to GC-induced cell death, we found that histone methyltransferases G9a and G9a-like protein (GLP), two glucocorticoid receptor (GR) coactivators, are required for GC-induced cell death in acute lymphoblastic leukemia (B-ALL) cell line Nalm6. We previously established in a few selected genes that automethylated G9a and GLP recruit heterochromatin protein 1γ (HP1γ) as another required coactivator. Here, we used a genome-wide analysis to show that HP1γ is selectively required for GC-regulated expression of the great majority of GR target genes that require G9a and GLP. To further address the importance of G9a and GLP methylation in this process and in cell physiology, we found that JIB-04, a selective JmjC family lysine demethylase inhibitor, increased G9a methylation and thereby increased G9a binding to HP1γ. This led to increased expression of GR target genes regulated by G9a, GLP and HP1γ and enhanced Nalm6 cell death. Finally, the KDM4 lysine demethylase subfamily demethylates G9a in vitro, in contrast to other KDM enzymes tested. Thus, inhibiting G9a/GLP demethylation potentially represents a novel method to restore sensitivity of treatment-resistant B-ALL tumors to GC-induced cell death.
Early redox activities modulate Xenopus tail regeneration
Authors: Ferreira Fernando , Raghunathan VijayKrishna , Luxardi Guillaume , Zhu Kan , Zhao Min 
Published: October 2018

AbstractRedox state sustained by reactive oxygen species (ROS) is crucial for regeneration; however, the interplay between oxygen (O2), ROS and hypoxia-inducible factors (HIF) remains elusive. Here we observe, using an optic-based probe (optrode), an elevated and steady O2influx immediately upon amputation. The spatiotemporal O2influx profile correlates with the regeneration ofXenopus laevistadpole tails. Inhibition of ROS production but not ROS scavenging decreases O2influx. Inhibition of HIF-1α impairs regeneration and stabilization of HIF-1α induces regeneration in the refractory period. In the regeneration bud, hypoxia correlates with O2influx, ROS production, and HIF-1α stabilization that modulate regeneration. Further analyses reveal that heat shock protein 90 is a putative downstream target of HIF-1α while electric current reversal is a de facto downstream target of HIF-1α. Collectively, the results show a mechanism for regeneration via the orchestration of O2influx, ROS production, and HIF-1α stabilization.
A shear-dependent NO-cGMP-cGKI cascade in platelets acts as an auto-regulatory brake of thrombosis
Authors: Wen Lai , Feil Susanne , Wolters Markus , Thunemann Martin , Regler Frank , Schmidt Kjestine , Friebe Andreas , Olbrich Marcus , Langer Harald , Gawaz Meinrad , de Wit Cor , Feil Robert 
Published: October 2018

AbstractMechanisms that limit thrombosis are poorly defined. One of the few known endogenous platelet inhibitors is nitric oxide (NO). NO activates NO sensitive guanylyl cyclase (NO-GC) in platelets, resulting in an increase of cyclic guanosine monophosphate (cGMP). Here we show, using cGMP sensor mice to study spatiotemporal dynamics of platelet cGMP, that NO-induced cGMP production in pre-activated platelets is strongly shear-dependent. We delineate a new mode of platelet-inhibitory mechanotransduction via shear-activated NO-GC followed by cGMP synthesis, activation of cGMP-dependent protein kinase I (cGKI), and suppression of Ca2+ signaling. Correlative profiling of cGMP dynamics and thrombus formation in vivo indicates that high cGMP concentrations in shear-exposed platelets at the thrombus periphery limit thrombosis, primarily through facilitation of thrombus dissolution. We propose that an increase in shear stress during thrombus growth activates the NO-cGMP-cGKI pathway, which acts as an auto-regulatory brake to prevent vessel occlusion, while preserving wound closure under low shear.