bluuebunny/crossref_metadata_2025_split huggingface dataset:
Performance of BDS Navigation Ionospheric Model During the Main Phase of Different Classified Geomagnetic Storms in China Region
Authors: Xue Junchen , Aquino Marcio , Veettil Sreeja Vadakke , Hu Xiaogong , Quan Lin 
Published: March 2020

AbstractGeomagnetic storms can have a great impact on the Earth's upper atmosphere, that is, the ionosphere. The activity of the ionosphere could be more pronounced during geomagnetic storms, which can make key ionospheric parameters, like total electron content (TEC), very hard to be modeled. The use of a Global Navigation Satellite System (GNSS) navigation ionospheric model is a conventional option for users to correct the ionospheric delay, which could suffer from the effects of storms. In this study, the performance of Beidou Navigation Satellite System (BDS) navigation ionospheric model in the China region during the main phase of different classes of geomagnetic storms is investigated for the first time. The analysis of the results revealed that the accuracy of the BDS navigation ionospheric model was impacted to different degrees during the storms. The effects during strong storms were the greatest, followed by moderate and weak storms. The impact on the accuracy of the model was characterized by latitude and local time. Furthermore, the accuracy of the model during the same class of storms was not always at the same level. The finding in this study could benefit the prediction of GNSS navigation ionospheric models' performance during geomagnetic storms.
The Impact of Rain on Ocean Surface Waves and Currents
Authors: Laxague Nathan J. M. , Zappa Christopher J. 
Published: March 2020

AbstractPrecipitation is an important component of the interaction between Earth's atmosphere and oceans, modifying air‐sea fluxes of momentum, heat, and gas. It has been hypothesized that rain's suppression of ocean surface gravity waves and centimeter‐scale wave enhancement should alter the nature of air‐sea momentum flux, resulting in increased near‐surface current. Here, we use field observations to describe this impact and measure the very near‐surface current response to rainfall. During heavy rain, surface‐roughening ring waves were generated and longer gravity waves were suppressed; immediately following, the magnitude of the near‐surface current increased in response to wind forcing but died as the rain subsided and long waves recovered. These first‐of‐their‐kind field observations indicate that rain reduces ocean wave form drag in favor of tangential stress, resulting in the acceleration of current near the sea surface.
Rosenbluth and Sagdeev in Trieste: The Birth of Modern Space Plasma Physics
Authors: Kennel Charles F. 
Published: March 2020

AbstractI was present at the birth of modern space plasma physics. Plasma physics and space physics had grown up, side‐by‐side, in the Cold War, and their child, space plasma physics, was conceived in America and the Soviet Union and born in 1965–1966 at the International Centre for Theoretical Physics in the Adriatic Port of Trieste, Italy, on the border with then Yugoslavia.
Social approach and social vigilance are differentially regulated by oxytocin receptors in the nucleus accumbens
Authors: Williams Alexia V. , Duque-Wilckens Natalia , Ramos-Maciel Stephanie , Campi Katharine L. , Bhela Shanu K. , Xu Christine K. , Jackson Kenneth , Chini Bice , Pesavento Patricia A. , Trainor Brian C. 
Published: March 2020

AbstractOxytocin is currently being considered as a novel therapeutic for anxiety disorders due to its ability to promote affiliative behaviors. In the nucleus accumbens (NAc) activation of oxytocin receptors (OTR) promotes social approach (time spent near an unfamiliar individual). Here, we show that stressful social experiences reduce the expression of NAc OTR mRNA, coinciding with decreases in social approach. Social stressors also increase social vigilance, characterized as orienting to an unfamiliar individual without approaching. Vigilance is a key component of behavioral inhibition, a personality trait that is a risk factor for anxiety disorders. To understand whether NAc OTR can modulate both social approach and vigilance, we use pharmacological approaches to assess the impact of activation or inhibition of NAc OTR downstream pathways on these behaviors. First, we show that in unstressed male and female California mice, inhibition of OTR by an unbiased antagonist (L-368,899) reduces social approach but does not induce social vigilance. Next, we show that infusion of Atosiban, an OTR-Gq antagonist/OTR-Gi agonist, has the same effect in unstressed females. Finally, we show that Carbetocin, a biased OTR-Gq agonist, increases social approach in stressed females while simultaneously inhibiting social vigilance. Taken together these data suggest that OTR in the NAc differentially modulate social approach and social vigilance, primarily through an OTR-Gq mechanism. Importantly, pharmacological inhibition of OTR alone is insufficient to induce vigilance in unstressed mice, suggesting that mechanisms modulating social approach may be distinct from mechanisms modulating social vigilance.
Loss of the nuclear Wnt pathway effector TCF7L2 promotes migration and invasion of human colorectal cancer cells
Authors: Wenzel Janna , Rose Katja , Haghighi Elham Bavafaye , Lamprecht Constanze , Rauen Gilles , Freihen Vivien , Kesselring Rebecca , Boerries Melanie , Hecht Andreas 
Published: March 2020

AbstractThe transcription factor TCF7L2 is indispensable for intestinal tissue homeostasis where it transmits mitogenic Wnt/β-Catenin signals in stem and progenitor cells, from which intestinal tumors arise. Yet, TCF7L2 belongs to the most frequently mutated genes in colorectal cancer (CRC), and tumor-suppressive functions of TCF7L2 were proposed. This apparent paradox warrants to clarify the role of TCF7L2 in colorectal carcinogenesis. Here, we investigated TCF7L2 dependence/independence of CRC cells and the cellular and molecular consequences of TCF7L2 loss-of-function. By genome editing we achieved complete TCF7L2 inactivation in several CRC cell lines without loss of viability, showing that CRC cells have widely lost the strict requirement for TCF7L2. TCF7L2 deficiency impaired G1/S progression, reminiscent of the physiological role of TCF7L2. In addition, TCF7L2-negative cells exhibited morphological changes, enhanced migration, invasion, and collagen adhesion, albeit the severity of the phenotypic alterations manifested in a cell-line-specific fashion. To provide a molecular framework for the observed cellular changes, we performed global transcriptome profiling and identified gene-regulatory networks in which TCF7L2 positively regulates the proto-oncogene MYC, while repressing the cell cycle inhibitors CDKN2C/CDKN2D. Consistent with its function in curbing cell motility and invasion, TCF7L2 directly suppresses the pro-metastatic transcription factor RUNX2 and impinges on the expression of cell adhesion molecules. Altogether, we conclude that the proliferation-stimulating activity of TCF7L2 persists in CRC cells. In addition, TCF7L2 acts as invasion suppressor. Despite its negative impact on cell cycle progression, TCF7L2 loss-of-function may thereby increase malignancy, which could explain why TCF7L2 is mutated in a sizeable fraction of colorectal tumors.
Loss of copy of MIR1-2 increases CDK4 expression in ileal neuroendocrine tumors
Authors: Contractor Tanupriya , Harris Chris R. 
Published: March 2020

AbstractIleal neuroendocrine tumors (I-NETs) are the most common tumors of the small intestine. Although I-NETs are known for a lack of recurrently mutated genes, a majority of tumors do show loss of one copy of chromosome 18. Among the genes on chromosome 18 is MIR1-2, which encodes a microRNA, MIR1-3p, with high complementarity to the mRNA of CDK4. Here we show that transfection of neuroendocrine cell lines with MIR1-3p lowered CDK4 expression and activity, and arrested growth at the G1 stage of the cell cycle. Loss of copy of MIR1-2 in ileal neuroendocrine tumors associated with increased expression of CDK4. Genetic events that attenuated RB activity, including loss of copy of MIR1-2 as well as loss of copy of CDKN1B and CDKN2A, were more frequent in tumors from patients with metastatic I-NETs. These data suggest that inhibitors of CDK4/CDK6 may benefit patients whose I-NETs show loss of copy of MIR1-2, particularly patients with metastatic disease.
Microbial symbionts and ecological divergence of Caribbean sponges: A new perspective on an ancient association
Authors: Freeman Christopher J , Easson Cole G , Matterson Kenan O , Thacker Robert W , Baker David M , Paul Valerie J 
Published: March 2020

Abstract
Marine sponges host diverse communities of microbial symbionts that expand the metabolic capabilities of their host, but the abundance and structure of these communities is highly variable across sponge species. Specificity in these interactions may fuel host niche partitioning on crowded coral reefs by allowing individual sponge species to exploit unique sources of carbon and nitrogen, but this hypothesis is yet to be tested. Given the presence of high sponge biomass and the coexistence of diverse sponge species, the Caribbean Sea provides a unique system in which to investigate this hypothesis. To test for ecological divergence among sympatric Caribbean sponges and investigate whether these trends are mediated by microbial symbionts, we measured stable isotope (δ13C and δ15N) ratios and characterized the microbial community structure of sponge species at sites within four regions spanning a 1700 km latitudinal gradient. There was a low (median of 8.2 %) overlap in the isotopic niches of sympatric species; in addition, host identity accounted for over 75% of the dissimilarity in both δ13C and δ15N values and microbiome community structure among individual samples within a site. There was also a strong phylogenetic signal in both δ15N values and microbial community diversity across host phylogeny, as well as a correlation between microbial community structure and variation in δ13C and δ15N values across samples. Together, this evidence supports a hypothesis of strong evolutionary selection for ecological divergence across sponge lineages and suggests that this divergence is at least partially mediated by associations with microbial symbionts.
The potential role of the HCN1 ion channel and BDNF-mTOR signaling pathways and synaptic transmission in the alleviation of PTSD
Authors: Ni Lianghui , Xu Yanling , Dong Sixuan , Kong Yujia , Wang Hong , Lu Guohua , Wang Yanyu , Li Qi , Li Changjiang , Du Zhongde , Sun Hongwei , Sun Lin 
Published: March 2020

AbstractThe function of the hyperpolarization-activated cyclic nucleotide-gated channel 1 (HCN1) and the expression of brain-derived neurotrophic factor (BDNF) may be involved in the pathogenesis of post-traumatic stress disorder (PTSD). This study aims to explore the role of the HCN1 channel, BDNF, and mTOR in the actions of PTSD and to examine whether synaptic transmission or plasticity is involved in the regulation of this disease. In the present study, rats were exposed to the single prolonged stress and electric foot shock (SPS&S) procedure, which can induce PTSD-like behaviors in rats. ZD7288 was administered by intracerebroventricular (i.c.v.) injection to one experimental group to inhibit the function of the HCN1 ion channel while 8-Br-cAMP was administered to another group to activate the function of the HCN1 ion channel. A series of behavioral tests and biochemical assessments of certain proteins (HCN1, BDNF, and pmTOR) and synaptic ultrastructure in the prefrontal cortex (PFC) and hippocampus (Hip) were then conducted. The SPS&S procedure induced apparent PTSD-like symptoms in rats. The administration of ZD7288 reduced the immobility time and escape latency time in the forced swim test (FST) and water maze test (WMT) with a decreased level of HCN1, upregulated BDNF-mTOR signaling pathways in the PFC and Hip, and synaptic ultrastructure changes in the PFC. In contrast, the administration of 8-Br-cAMP, which led to a higher level of HCN1 in PFC and Hip, resulted in a decreased number of entries to the open arms without significant change in total arm entries in the elevated plus maze test (EPMT) as well as a shorter center square distance and total distance in the open field test (OFT). Extended escape latency time was also observed in the WMT although there was no alteration of BDNF-mTOR signaling pathways and synaptic ultrastructure in the PFC and Hip. Overall, the inhibition of HCN1, which can alleviate PTSD-like behavior of rats by relieving depression and improving learning ability, may be related to the upregulated BDNF-mTOR signaling pathways and synaptic transmission.
Therapeutic ACPA inhibits NET formation: a potential therapy for neutrophil-mediated inflammatory diseases
Authors: Chirivi Renato G. S. , van Rosmalen Jos W. G. , van der Linden Maarten , Euler Maximilien , Schmets Gonny , Bogatkevich Galina , Kambas Konstantinos , Hahn Jonas , Braster Quinte , Soehnlein Oliver , Hoffmann Markus H. , Es Helmuth H. G. van , Raats Jos M. H. 
Published: March 2020

AbstractExcessive release of neutrophil extracellular traps (NETs) is associated with disease severity and contributes to tissue injury, followed by severe organ damage. Pharmacological or genetic inhibition of NET release reduces pathology in multiple inflammatory disease models, indicating that NETs are potential therapeutic targets. Here, we demonstrate using a preclinical basket approach that our therapeutic anti-citrullinated protein antibody (tACPA) has broad therapeutic potential. Treatment with tACPA prevents disease symptoms in various mouse models with plausible NET-mediated pathology, including inflammatory arthritis (IA), pulmonary fibrosis, inflammatory bowel disease and sepsis. We show that citrulline residues in the N-termini of histones 2A and 4 are specific targets for therapeutic intervention, whereas antibodies against other N-terminal post-translational histone modifications have no therapeutic effects. Because citrullinated histones are generated during NET release, we investigated the ability of tACPA to inhibit NET formation. tACPA suppressed NET release from human neutrophils triggered with physiologically relevant human disease-related stimuli. Moreover, tACPA diminished NET release and potentially initiated NET uptake by macrophages in vivo, which was associated with reduced tissue damage in the joints of a chronic arthritis mouse model of IA. To our knowledge, we are the first to describe an antibody with NET-inhibiting properties and thereby propose tACPA as a drug candidate for NET-mediated inflammatory diseases, as it eliminates the noxious triggers that lead to continued inflammation and tissue damage in a multidimensional manner.
Titanium-based potassium-ion battery positive electrode with extraordinarily high redox potential
Authors: Fedotov Stanislav S. , Luchinin Nikita D. , Aksyonov Dmitry A. , Morozov Anatoly V. , Ryazantsev Sergey V. , Gaboardi Mattia , Plaisier Jasper R. , Stevenson Keith J. , Abakumov Artem M. , Antipov Evgeny V. 
Published: March 2020

AbstractThe rapid progress in mass-market applications of metal-ion batteries intensifies the development of economically feasible electrode materials based on earth-abundant elements. Here, we report on a record-breaking titanium-based positive electrode material, KTiPO4F, exhibiting a superior electrode potential of 3.6 V in a potassium-ion cell, which is extraordinarily high for titanium redox transitions. We hypothesize that such an unexpectedly major boost of the electrode potential benefits from the synergy of the cumulative inductive effect of two anions and charge/vacancy ordering. Carbon-coated electrode materials display no capacity fading when cycled at 5C rate for 100 cycles, which coupled with extremely low energy barriers for potassium-ion migration of 0.2 eV anticipates high-power applications. Our contribution shows that the titanium redox activity traditionally considered as “reducing” can be upshifted to near-4V electrode potentials thus providing a playground to design sustainable and cost-effective titanium-containing positive electrode materials with promising electrochemical characteristics.
Groundwater as a major source of dissolved organic matter to Arctic coastal waters
Authors: Connolly Craig T. , Cardenas M. Bayani , Burkart Greta A. , Spencer Robert G. M. , McClelland James W. 
Published: March 2020

AbstractGroundwater is projected to become an increasing source of freshwater and nutrients to the Arctic Ocean as permafrost thaws, yet few studies have quantified groundwater inputs to Arctic coastal waters under contemporary conditions. New measurements along the Alaska Beaufort Sea coast show that dissolved organic carbon and nitrogen (DOC and DON) concentrations in supra-permafrost groundwater (SPGW) near the land-sea interface are up to two orders of magnitude higher than in rivers. This dissolved organic matter (DOM) is sourced from readily leachable organic matter in surface soils and deeper centuries-to millennia-old soils that extend into thawing permafrost. SPGW delivers approximately 400–2100 m3 of freshwater, 14–71 kg of DOC, and 1–4 kg of DON to the coastal ocean per km of shoreline per day during late summer. These substantial fluxes are expected to increase as massive stocks of frozen organic matter in permafrost are liberated in a warming Arctic.
Protein-polymer bioconjugates via a versatile oxygen tolerant photoinduced controlled radical polymerization approach
Authors: Theodorou Alexis , Liarou Evelina , Haddleton David M. , Stavrakaki Iren Georgia , Skordalidis Panagiotis , Whitfield Richard , Anastasaki Athina , Velonia Kelly 
Published: March 2020

AbstractThe immense application potential of amphiphilic protein-polymer conjugates remains largely unexplored, as established “grafting from” synthetic protocols involve time-consuming, harsh and disruptive deoxygenation methods, while “grafting to” approaches result in low yields. Here we report an oxygen tolerant, photoinduced CRP approach which readily affords quantitative yields of protein-polymer conjugates within 2 h, avoiding damage to the secondary structure of the protein and providing easily accessible means to produce biomacromolecular assemblies. Importantly, our methodology is compatible with multiple proteins (e.g. BSA, HSA, GOx, beta-galactosidase) and monomer classes including acrylates, methacrylates, styrenics and acrylamides. The polymerizations are conveniently conducted in plastic syringes and in the absence of any additives or external deoxygenation procedures using low-organic content media and ppm levels of copper. The robustness of the protocol is further exemplified by its implementation under UV, blue light or even sunlight irradiation as well as in buffer, nanopure, tap or even sea water.
Coral skeletons reveal the history of nitrogen cycling in the coastal Great Barrier Reef
Authors: Erler Dirk V. , Farid Hanieh Tohidi , Glaze Thomas D. , Carlson-Perret Natasha L. , Lough Janice M. 
Published: March 2020

AbstractAnthropogenic nutrient discharge to coastal marine environments is commonly associated with excessive algal growth and ecosystem degradation. However in the world’s largest coral reef ecosystem, the Great Barrier Reef (GBR), the response to enhanced terrestrial nutrient inputs since European settlement in the 1850’s remains unclear. Here we use a 333 year old composite record (1680–2012) of 15N/14N in coral skeleton-bound organic matter to understand how nitrogen cycling in the coastal GBR has responded to increased anthropogenic nutrient inputs. Our major robust finding is that the coral record shows a long-term decline in skeletal 15N/14N towards the present. We argue that this decline is evidence for increased coastal nitrogen fixation rather than a direct reflection of anthropogenic nitrogen inputs. Reducing phosphorus discharge and availability would short-circuit the nitrogen fixation feedback loop and help avoid future acute and chronic eutrophication in the coastal GBR.
Degree and site of chromosomal instability define its oncogenic potential
Authors: Hoevenaar Wilma H. M. , Janssen Aniek , Quirindongo Ajit I. , Ma Huiying , Klaasen Sjoerd J. , Teixeira Antoinette , van Gerwen Bastiaan , Lansu Nico , Morsink Folkert H. M. , Offerhaus G. Johan A. , Medema René H. , Kops Geert J. P. L. , Jelluma Nannette 
Published: March 2020

AbstractMost human cancers are aneuploid, due to a chromosomal instability (CIN) phenotype. Despite being hallmarks of cancer, however, the roles of CIN and aneuploidy in tumor formation have not unequivocally emerged from animal studies and are thus still unclear. Using a conditional mouse model for diverse degrees of CIN, we find that a particular range is sufficient to drive very early onset spontaneous adenoma formation in the intestine. In mice predisposed to intestinal cancer (ApcMin/+), moderate CIN causes a remarkable increase in adenoma burden in the entire intestinal tract and especially in the distal colon, which resembles human disease. Strikingly, a higher level of CIN promotes adenoma formation in the distal colon even more than moderate CIN does, but has no effect in the small intestine. Our results thus show that CIN can be potently oncogenic, but that certain levels of CIN can have contrasting effects in distinct tissues.
Lipid analogs reveal features critical for hemolysis and diminish granadaene mediated Group B Streptococcus infection
Authors: Armistead Blair , Herrero-Foncubierta Pilar , Coleman Michelle , Quach Phoenicia , Whidbey Christopher , Justicia Jose , Tapia Ruben , Casares Raquel , Millán Alba , Haidour Ali , Granger Javier Rodriguez , Vornhagen Jay , Santana-Ufret Verónica , Merillat Sean , Adams Waldorf Kristina , Cuerva Juan Manuel , Rajagopal Lakshmi 
Published: March 2020

AbstractAlthough certain microbial lipids are toxins, the structural features important for cytotoxicity remain unknown. Increased functional understanding is essential for developing therapeutics against toxic microbial lipids. Group B Streptococci (GBS) are bacteria associated with preterm births, stillbirths, and severe infections in neonates and adults. GBS produce a pigmented, cytotoxic lipid, known as granadaene. Despite its importance to all manifestations of GBS disease, studies towards understanding granadaene’s toxic activity are hindered by its instability and insolubility in purified form. Here, we report the synthesis and screening of lipid derivatives inspired by granadaene, which reveal features central to toxin function, namely the polyene chain length. Furthermore, we show that vaccination with a non-toxic synthetic analog confers the production of antibodies that inhibit granadaene-mediated hemolysis ex vivo and diminish GBS infection in vivo. This work provides unique structural and functional insight into granadaene and a strategy to mitigate GBS infection, which will be relevant to other toxic lipids encoded by human pathogens.