bluuebunny/crossref_metadata_2025_split huggingface dataset:
The dynamics of the globular cluster M22 (NGC 6656)
Authors: Chen D. , Chen L. , Wang J. J. 
Published: March 2020

AbstractWe have used the Hubble Space Telescope (HST) observations to measure proper motion of the globular cluster NGC 6656 (M22) with respect to the background bulge stars and its internal velocity dispersion profile. Based on the proper motion of the clusters, its space velocity and orbit are also calculated. The central velocity dispersion in radial and tangential components of the internal motion of cluster stars is 16.99 km s−1. We derive the mass-to-light ratio M/LV∼3.3 ± 0.2 which is relatively higher than the previous works.
Supermassive stars as the origin of the multiple populations in globular clusters
Authors: Gieles Mark , Charbonnel Corinne 
Published: March 2020

AbstractGlobular clusters (GCs) display anomalous light-elements abundances (HeCNONaMgAl), resembling the yields of hot-hydrogen burning, but there is no consensus yet on the origin of these ubiquitous multiple populations. We present a model in which a super-massive star (SMS, ≳103 M⊙) forms via stellar collisions during GC formation and pollutes the intra-cluster medium. The growth of the SMS finds a balance with the wind mass loss rate, such that the SMS can produce a significant fraction of the total GC mass in processed material, thereby overcoming the so-called mass-budget problem that plagues other models. Because of continuous rejuvenation, the SMS acts as a ‘conveyer-belt’ of hot-hydrogen burning yields with (relatively) low He abundances, in agreement with empirical constraints. Additionally, the amount of processed material per unit of GC mass correlates with GC mass, addressing the specific mass budget problem. We discuss uncertainties and tests of this new self-enrichment scenario.
Unveiling forming star clusters in the young Universe
Authors: Vanzella E. , Calura F. , Meneghetti M. , Caminha G. B. , Mercurio A. , Castellano M. , Rosati P. , Grillo C. , Sani E. , Cupani G. 
Published: March 2020

AbstractThe identification of young massive star clusters (YMCs) at high redshift is becoming a real fact. We present recent results from Hubble deep imaging and VLT/ MUSE - X-Shooter observations boosted by strong gravitational lensing. We report on two parsec-scale star-forming systems at z = 6.145 and 2.37 (>10 Gyrs of look back time) currently representing the best candidate high-z YMCs. All of this also implies that the search for globular cluster precursors has already begun.
Atmospheric Freshwater Transport From the Atlantic to the Pacific Ocean: A Lagrangian Analysis
Authors: Dey Dipanjan , Döös Kristofer 
Published: March 2020

AbstractThe Atlantic‐to‐Pacific atmospheric freshwater transport was calculated using Lagrangian water mass trajectories. These were decomposed into eastward and westward moving classes, carrying water over Afro‐Eurasia and over America, respectively. The results reveal that the midlatitude westerlies are contributing to midlatitude precipitation in the Pacific Ocean through transporting water mass from the midlatitude Atlantic Ocean over Afro‐Eurasia. In addition, precipitation in the Eastern Tropical Pacific Ocean is found to be associated with the easterly winds carrying water mass from the tropical Atlantic Ocean. A quantitative analysis of the atmospheric freshwater transport furthermore shows that annually, the westerlies carry 0.40 Sv, approximately twice as much water as the easterly trade winds (0.26 Sv) to the Pacific Ocean, but with a strong seasonality. The Atlantic Ocean exports more freshwater across Afro‐Eurasia than across America, except during the June–August periods. The average residence time of this atmospheric water transport is roughly twice as long when it crosses Afro‐Eurasia (54 days) rather than America (24 days).
The Relationship Between Cusp Region Ion Outflows and East‐West Magnetic Field Fluctuations at 4,000‐km Altitude
Authors: Hatch S. M. , Moretto T. , Lynch K. A. , Laundal K. M. , Gjerloev J. W. , Lund E. J. 
Published: March 2020

AbstractA number of interdependent conditions and processes contribute to ionospheric‐origin energetic (
10 eV to several keV) ion outflows. Due to these interdependences and the associated observational challenges, energetic ion outflows remain a poorly understood facet of atmosphere‐ionosphere‐magnetosphere coupling. Here we demonstrate the relationship between east‐west magnetic field fluctuations (
) and energetic outflows in the magnetosphere‐ionosphere transition region. We use dayside cusp region FAST satellite observations made near apogee (
4,180‐km altitude) near fall equinox and solstices in both hemispheres to derive statistical relationships between ion upflow and
spectral power as a function of spacecraft frame frequency bands between 0 and 4 Hz. Identification of ionospheric‐origin energetic ion upflows is automated, and the spectral power
in each frequency band is obtained via integration of
power spectral density. Derived relationships are of the form
for upward ion flux
at 130‐km altitude, with
the mapped upward ion flux for a nominal spectral power
nT
. The highest correlation coefficients are obtained for spacecraft frame frequencies
0.1–0.5 Hz. Summer solstice and fall equinox observations yield power law indices
0.9–1.3 and correlation coefficients
, while winter solstice observations yield
0.4–0.8 with
. Mass spectrometer observations reveal that the oxygen/hydrogen ion composition ratio near summer solstice is much greater than the corresponding ratio near winter. These results reinforce the importance of ion composition in outflow models. If observed
perturbations result from Doppler‐shifted wave structures with near‐zero frequencies, we show that spacecraft frame frequencies
0.1–0.5 Hz correspond to perpendicular spatial scales of several to tens of kilometers.
Tide‐Storm Surge Interactions in Highly Altered Estuaries: How Channel Deepening Increases Surge Vulnerability
Authors: Familkhalili R. , Talke S. A. , Jay D. A. 
Published: March 2020

AbstractWe develop idealized analytical and numerical models to study how storm surge amplitudes vary within frictional, weakly convergent, nonreflective estuaries. Friction is treated using Chebyshev polynomials. Storm surge is represented as the sum of two sinusoidal components, and a third constituent represents the semidiurnal tide (D2). An empirical fit of storm surge shows that two sinusoidal components adequately represent storm surge above a baseline value (R2 = 0.97). We find that the spatial transformation of surge amplitudes depends on the depth of the estuary, and characteristics of the surge wave including time scale, amplitude, asymmetry, and surge‐tide relative phase. Analytical model results indicate that surge amplitude decays more slowly (larger e‐folding) in a deeper channel for all surge time scales (12–72 hr). Deepening of an estuary results in larger surge amplitudes. Sensitivity studies show that surges with larger primary amplitudes (or shorter time scales) damp faster than those with smaller amplitudes (or larger time scales). Moreover, results imply that there is a location with maximum sensitivity to altered depth, offshore surge amplitude, and time scale and that the location of observed maximum change in surge amplitude along an estuary of simple form moves upstream when depth is increased. Further, the relative phase of surge to tide and surge asymmetry can change the spatial location of maximum change in surge. The largest change due to increased depth occurs for a large surge with a short time scale. The results suggest that both sea level rise and channel deepening may also alter surge amplitudes.
Topographical Control of the Source‐Sink and Wind Stress‐Driven Planetary Geostrophic Circulation in a Polar Basin
Authors: Gavilan Pascual‐Ahuir Estanislao , Willmott Andrew J. , Morales Maqueda Miguel , Luneva Maria 
Published: March 2020

AbstractThe effects of topography on the barotropic circulation in a polar basin are examined analytically and numerically. New approximate linear analytical solutions are presented for steady‐state wind and boundary forced barotropic planetary geostrophic circulation in a circular polar basin with a step shelf. The solutions are obtained by retaining the full spherical geometry in the derivation of the forced potential vorticity equation; thereafter the colatitude is fixed in the coefficients of this governing equation. The accuracy of the analytical solutions is evaluated by comparing them with the equivalent numerical solutions obtained using the NEMO modeling system. Subsequently, the impact of a nonuniform width shelf on source‐sink‐driven circulation is investigated numerically. The equipartition of fluid entering the source strait into cyclonic and anticyclonic shelf currents, exiting the basin at the sink strait, in a basin with a uniform width shelf is shown to be modified when the shelf width varies. In general, the wider shelf supports a current with larger transport, irrespective of the azimuthal extent of the wider shelf. The study concludes with a numerical investigation of wind‐driven circulation in a basin with a step shelf, three straits, and a transpolar ridge, a prototype Arctic Ocean simulation. Topographic steering by the ridge supports a transpolar drift current, the magnitude of which depends on the ridge height. Without the ridge, the transpolar drift current is absent and the circulation is confined to gyres on the shelf and in the deep basin.
Large Eddy Simulation on Horizontal Convective Rolls that Caused an Aircraft Accident during its Landing at Narita Airport
Authors: Ito J. , Niino H. , Yoshino K. 
Published: March 2020

AbstractAn accident occurred when an aircraft landed at Narita International Airport, Japan, on 20 June 2012. The aircraft encountered rapid changes of winds together with strong turbulence, although the weather was fair. In the present study, a two‐domain nested regional weather prediction models are used. The results in the outer domain show that southwesterly winds associated with a synoptic extratropical cyclone were locally accelerated to the southwest of the airport resulting in strong vertical shear. The simulation in the inner domain reproduces horizontal convective rolls, which are similar to those observed by a Doppler lidar at the airport. The wind velocity component parallel to the runway had a spatial variation of about 10 m s
. The present approach using a large eddy simulation is useful for clarifying environments and features of horizontal convective rolls and forecasting low‐level wind shear associated with them, which can be a significant risk for aircraft.
Cooperative synaptic and intrinsic plasticity in a disynaptic limbic circuit drive stress-induced anhedonia and passive coping in mice
Authors: Pignatelli Marco , Tejeda Hugo A. , Barker David J. , Bontempi Leonardo , Wu Jocelyn , Lopez Alejandra , Palma Ribeiro Sissi , Lucantonio Federica , Parise Eric M. , Torres-Berrio Angélica , Alvarez-Bagnarol Yocasta , Marino Rosa A. M. , Cai Zhao-Lin , Xue Mingshan , Morales Marisela , Tamminga Carol A. , Nestler Eric J. , Bonci Antonello 
Published: March 2020

AbstractStress promotes negative affective states, which include anhedonia and passive coping. While these features are in part mediated by neuroadaptations in brain reward circuitry, a comprehensive framework of how stress-induced negative affect may be encoded within key nodes of this circuit is lacking. Here, we show in a mouse model for stress-induced anhedonia and passive coping that these phenomena are associated with increased synaptic strength of ventral hippocampus (VH) excitatory synapses onto D1 medium spiny neurons (D1-MSNs) in the nucleus accumbens medial shell (NAcmSh), and with lateral hypothalamus (LH)-projecting D1-MSN hyperexcitability mediated by decreased inwardly rectifying potassium channel (IRK) function. Stress-induced negative affective states are prevented by depotentiation of VH to NAcmSh synapses, restoring Kir2.1 function in D1R-MSNs, or disrupting co-participation of these synaptic and intrinsic adaptations in D1-MSNs. In conclusion, our data provide strong evidence for a disynaptic pathway controlling maladaptive emotional behavior.
Moth-eye shaped on-demand broadband and switchable perfect absorbers based on vanadium dioxide
Authors: Badloe Trevon , Kim Inki , Rho Junsuk 
Published: March 2020

AbstractTwo biomimetic, moth-eye structure, perfect absorbers in the visible and near infrared regions are introduced and investigated. The moth-eye structure is made up of vanadium oxide (VO2), which is a phase change material that changes from an insulator state to a metallic state at around 85 °C. The VO2 structure sits on top of a sapphire (Al2O3) dielectric spacer layer, above a gold (Au) back reflector. Two perfect absorbers are designed, one with perfect absorption over an ultra-broadband range between 400 and 1,600 nm, for both the insulating and metallic phases, while the second can switch between being a perfect absorber or not in the range 1,000 and 1,600 nm. The absorption profiles and electric and magnetic fields are examined and discussed to provide insight into how absorbers function in the four different situations.
Evaluation of antifungal effect and toxicity of xanthyletin and two bacterial metabolites against Thai isolates of Pythium insidiosum
Authors: Wittayapipath Kittiya , Yenjai Chavi , Prariyachatigul Chularut , Hamal Petr 
Published: March 2020

AbstractPythiosis is a harmful disease caused by Pythium insidiosum, an aquatic oomycete. Therapeutic protocols based on antifungal drugs are often ineffective because the cytoplasmic membrane of P. insidiosum does not contain ergosterol. Therefore, the treatment of pythiosis is still challenging, particularly making use of natural products and secondary metabolites from bacteria. In this study, xanthyletin and substances obtained from Pseudomonas stutzeri ST1302 and Klebsiella pneumoniae ST2501 exhibited anti-P. insidiosum activity and, moreover, xanthyletin was non-toxic against human cell lines. The hyphae of P. insidiosum treated with these three substances exhibited lysis holes on a rough surface and release of anamorphic material. Therefore, xanthyletin could be considered a promising alternative agent for treating cutaneous pythiosis in the near future.
Quantum State Optimization and Computational Pathway Evaluation for Gate-Model Quantum Computers
Authors: Gyongyosi Laszlo 
Published: March 2020

AbstractA computational problem fed into a gate-model quantum computer identifies an objective function with a particular computational pathway (objective function connectivity). The solution of the computational problem involves identifying a target objective function value that is the subject to be reached. A bottleneck in a gate-model quantum computer is the requirement of several rounds of quantum state preparations, high-cost run sequences, and multiple rounds of measurements to determine a target (optimal) state of the quantum computer that achieves the target objective function value. Here, we define a method for optimal quantum state determination and computational path evaluation for gate-model quantum computers. We prove a state determination method that finds a target system state for a quantum computer at a given target objective function value. The computational pathway evaluation procedure sets the connectivity of the objective function in the target system state on a fixed hardware architecture of the quantum computer. The proposed solution evolves the target system state without requiring the preparation of intermediate states between the initial and target states of the quantum computer. Our method avoids high-cost system state preparations and expensive running procedures and measurement apparatuses in gate-model quantum computers. The results are convenient for gate-model quantum computations and the near-term quantum devices of the quantum Internet.
Shelf humic substances as carriers for basin-scale iron transport in the North Pacific
Authors: Yamashita Youhei , Nishioka Jun , Obata Hajime , Ogawa Hiroshi 
Published: March 2020

AbstractIron is one of the key elements controlling phytoplankton growth in large areas of the global ocean. Aeolian dust has traditionally been considered the major external source of iron in the North Pacific. Recent studies have indicated that sedimentary iron from the shelf region of the Sea of Okhotsk has a strong impact on the iron distribution in the North Pacific, while the mechanism supporting its long-distance transport remains poorly understood. Here, we report that refractory shelf humic substances, which complex and carry dissolved iron, are transported conservatively at least 4000 km from the shallow sediments of the Sea of Okhotsk to the subtropical North Pacific with the circulation of intermediate water. This result indicates that shelf humic substances are probably one of the key factors shaping the distribution of dissolved iron in the ocean interior.
T-Cell Receptor Variable β Domains Rigidify During Affinity Maturation
Authors: Fernández-Quintero Monica L. , Seidler Clarissa A. , Liedl Klaus R. 
Published: March 2020

AbstractWe investigated T-cell receptor variable β chains binding to the superantigen staphylococcal enterotoxin C3 (SEC 3) with structure information in different stages of affinity maturation. Metadynamics in combination with molecular dynamics simulations allow to access the micro-to-millisecond timescale and reveal a strong effect of energetically significant mutations on the flexibility of the antigen-binding site. The observed changes in dynamics of the complementarity determining region (CDR) loops, especially the CDR 2, and HV 4 loop on this specific pathway of affinity maturation are reflected in their structural diversity, thermodynamics of conformations and kinetics of structural transitions. In addition, this affinity maturation pathway follows the concept of conformational selection, because even without the presence of the antigen the binding competent state is present in this pre-existing ensemble of conformations. In all stages of this affinity maturation process we observe a link between specificity and reduced flexibility.
Multi-genomic analysis of the cation diffusion facilitator transporters from algae
Authors: Ibuot Aniefon , Dean Andrew P , Pittman Jon K 
Published: March 2020

Abstract
Metal transport processes are relatively poorly understood in algae in comparison to higher plants and other eukaryotes. A screen of genomes from 33 taxonomically diverse algal species was conducted to identify members of the Cation Diffusion Facilitator (CDF) family of metal ion transporter. All algal genomes contained at least one CDF gene with four species having &gt;10 CDF genes (median of 5 genes per genome), further confirming that this is a ubiquitous gene family. Phylogenetic analysis suggested a CDF gene organisation of five groups, which includes Zn-CDF, Fe/Zn-CDF and Mn-CDF groups, consistent with previous phylogenetic analyses, and two functionally undefined groups. One of these undefined groups was algal specific although excluded chlorophyte and rhodophyte sequences. The majority of sequences (22 out of 26 sequences) from this group had a putative ion binding site motif within transmembrane domain 2 and 5 that was distinct from other CDF proteins, such that alanine or serine replaced the conserved histidine residue. The phylogenetic grouping was supported by sequence cluster analysis. Yeast heterologous expression of CDF proteins from Chlamydomonas reinhardtii indicated Zn2+ and Co2+ transport function by CrMTP1, and Mn2+ transport function by CrMTP2, CrMTP3 and CrMTP4, which validated the phylogenetic prediction. However, the Mn-CDF protein CrMTP3 was also able to provide zinc and cobalt tolerance to the Zn- and Co-sensitive zrc1 cot1 yeast strain. There is wide diversity of CDF transporters within the algae lineage, and some of these genes may be attractive targets for future applications of metal content engineering in plants or microorganisms.
Circulating lncRNA DANCR as a potential auxillary biomarker for the diagnosis and prognostic prediction of colorectal cancer
Authors: Shen Xianjuan , Xue Yajing , Cong Hui , Wang Xudong , Fan Zhiwei , Cui Xiaopeng , Ju Shaoqing 
Published: March 2020

Abstract
Studies have shown that long non-coding RNAs (lncRNAs) play vital roles in the development of cancer, including colorectal cancer (CRC). Our purpose is to validate the diagnostic value of serum differentiation antagonizing non-protein coding RNA (DANCR) in CRC by focusing on its expression and clinical application. lncRNA expression profiles of CRC patients were obtained and analyzed by repurposing the publically available microarray data. Tissue or serum specimens were obtained from 40 patients with primary CRC, 10 patients with recurrent CRC, 40 patients with colorectal polyps, and 40 healthy controls. It was found that DANCR level in the CRC tissue and serum was significantly increased, and serum DANCR expression was decreased in post-operative patients as compared with that in pre-treatment patients and recurrent patients. In addition, serum DANCR expression was significantly correlated with different TNM stages. Correlation analysis of DANCR and other diagnostic indicators showed that the serum DANCR expression level was significantly correlated with CA199 but not with CEA in CRC patients. As for diagnostic efficiency by ROC analysis, the area under the curve (AUC) of serum DANCR was higher than that of CEA and CA199 in CRC group vs. colorectal polyp group. Simultaneous detection of DANCR, CEA and CA199 yielded the highest sensitivity and AUC as compared with either of them alone. Taken together, serum DANCR was up-regulated in CRC patients and high expression of DANCR may prove to be a potential biomarker for the diagnosis of CRC.
Astragalus polysaccharides inhibit ovarian cancer cell growth via microRNA-27a/FBXW7 signaling pathway
Authors: Guo Yanling , Zhang Zhenxing , Wang Zhaoxia , Liu Guoqi , Liu Yingying , Wang Huijie 
Published: March 2020

Abstract
Astragalus polysaccharide (APS), a natural antioxidant found in Astragalus membranaceus emerging as a novel anticancer agent, exerts antiproliferative and pro-apoptotic activity in various cancer cell types, but its effect on ovarian cancer (OC) remains unknown. In the present study, we tried to elucidate the role and mechanism of APS in OC cells. Our results showed that APS treatment suppressed the proliferation and induced apoptosis in OC cells. Afterward, the microRNA (miRNA) profiles in APS-treated cells were determined by a microarray assay, and whether APS affected OV-90 cells through regulation of miRNA was determined. Among these aberrant miRNAs, miR-27a was selected for further study as its oncogenic roles in various human cancers. Moreover, we found overexpression of miR-27a reversed the antiproliferation and pro-apoptotic effects of APS on OC cells. F-box and WD-40 domain protein 7 (FBXW7), a classical tumor suppressor, was found directly targeted by miR-27a and its translation was suppressed by miR-27a in OC cells. Finally, it was also observed that knockdown of FBXW7 by si-FBXW7 reversed the tumor suppressive activity of APS in OC cells, which is similar to the effects of miR-27a overexpression. Our findings demonstrate that APS can suppress OC cell growth in vitro via miR-27a/FBXW7 axis, and this observation reveals the therapeutic potential of APS for treatment of OC.