bluuebunny/crossref_metadata_2025_split huggingface dataset:
Robust Increases in Extreme Pacific North American Events Under Greenhouse Warming
Authors: Liu Zhongfang , He Xiaogang , Ma Wentao , Wang Yue 
Published: January 2020

AbstractThe Pacific North American (PNA) pattern is an internal mode of the Northern Hemisphere atmosphere, which strongly affects the hydroclimate and ecosystems of the Pacific‐North American sector. Recent studies have suggested a more positive PNA pattern in response to greenhouse warming, but how extreme PNA events will change remains unclear. Based on results from the Coupled Model Intercomparison Project Phase 5 multimodel ensemble, we find a 50% increase in the frequency of extreme positive PNA events and a 32% increase in extreme negative PNA events in the 21st century relative to the twentieth century. The increased frequency arises from a shift toward a more positive PNA pattern and is enhanced by more frequent ENSO events under greenhouse warming. Our study suggests that a continued increase in greenhouse‐gas emissions is likely to cause increased occurrence of extreme PNA events, thus increasing the risk of extreme weather and climate in North America.
The Far Ultraviolet Signatures of Conjugate Photoelectrons Seen by the Special Sensor Ultraviolet Spectrographic Imager
Authors: Kil Hyosub , Schaefer Robert K. , Paxton Larry J. , Jee Geonhwa 
Published: January 2020

AbstractThis study investigates the origin of anomalous far ultraviolet emissions observed at night at the subauroral region by the Special Sensor Ultraviolet Spectrographic Imager on board the Defense Meteorological Satellite System‐F16 satellite. The global distribution of the anomalous emission is derived using the measurements of the oxygen atom 130.4‐nm emission in 2017. Our results show the extension of the anomalous emission from high latitudes to middle latitudes in the Northern American‐Atlantic sector during the December solstice and in the Southern Australia‐New Zealand sector during the June solstice. These observations indicate that the anomalous emission occurs in the winter hemisphere and is pronounced at locations close to the magnetic poles. The good agreement between the morphology of the anomalous emission and the predicted distribution of conjugate photoelectrons leads to the conclusion that the anomalous emissions are the signatures of conjugate photoelectrons.
Is Nightside Outflow Required to Induce Magnetospheric Sawtooth Oscillations
Authors: Zhang Binzheng , Brambles Oliver J. , Lotko William , Lyon John G. 
Published: January 2020

AbstractIonospheric outflow plays an important role in the mass coupling between the ionosphere and the coupled solar wind‐magnetosphere system. Previous modeling studies have shown that outflowing ionospheric ions may induce magnetospheric sawtooth oscillations through mass loading of the magnetotail, stretching the magnetic field lines, and reducing nightside reconnection. The spatial distribution of polar cap outflow in these simulation studies produces significant outflow in the auroral oval and lacks a distinct cusp source. Thus, the question arises whether cusp outflow can induce sawtooth oscillations. We show controlled numerical experiments with magnetospheric sawtooth oscillations induced by an idealized cusp outflow for driving conditions representative of the interaction of an interplanetary coronal mass ejection with Earth's magnetosphere. The analysis shows that although only a small portion (10%) of the cusp outflow is entrained within the plasma sheet, it is effective in inducing magnetospheric sawtooth oscillations, similar to previous experiments.
Gravity Wave Influences On Mesoscale Divergence: An Observational Case Study
Authors: Stephan C. C. , Lane T. P. , Jakob C. 
Published: January 2020

AbstractCharacteristics of tropospheric low‐frequency gravity waves are diagnosed in radiosonde soundings from the Tropical Warm Pool‐International Cloud Experiment near Darwin, Australia. The waves have typical vertical wavelengths of about 4 km, horizontal wavelengths of about 600 km, and intrinsic periods of about 12 hr. These scales match those of the vertical, horizontal, and temporal variability found in area‐averaged horizontal wind divergence over the same domain. Vertical profiles of divergence show wave‐like structures with variability of the order of 2
10
s
in the free troposphere. The results for Darwin are similar to previously reported observed mesoscale patterns of divergence/convergence over the tropical Atlantic. The findings imply that tropical divergence on spatial scales of a few hundred kilometers, which is known to influence the organization of convection, may be forced by gravity waves.
Coordinated Observations of 8‐ and 6‐hr Tides in the Mesosphere and Lower Thermosphere by Three Meteor Radars Near 60°S Latitude
Authors: Liu Guiping , Janches Diego , Lieberman Ruth S. , Moffat‐Griffin Tracy , Fritts David C. , Mitchell Nicholas J. 
Published: January 2020

AbstractAtmospheric 8‐ and 6‐hr tides are observed for the first time in the zonal and meridional winds at ~82–97 km altitudes simultaneously at Tierra del Fuego (TDF; 53.7°S, 67.7°W), King Edward Point (KEP; 54.3°S, 36.5°W), and Rothera (ROT; 67.5°S, 68.0°W) at Southern Hemisphere (SH) middle‐to‐high latitudes during long time spans, allowing to reveal climatology and migrating nature. The monthly averaged amplitudes vary between ~1 and 8 m/s for the 8‐hr tides while the amplitudes of 6‐hr tides are smaller ~0.5–4 m/s. Both tides exhibit an annual pattern having the amplitude maxima during SH winter and minima in SH summer. The tidal phases are smaller (earlier) in the zonal wind than in the meridional wind by about 90°. The phase differences observed between TDF and KEP, which are located at similar latitudes but different longitudes suggest the propagation of migrating tides. The study finds that 8‐ and 6‐hr tides are correlated.
Bias Correction of Paleoclimatic Reconstructions: A New Look at 1,200+ Years of Upper Colorado River Flow
Authors: Robeson Scott M. , Maxwell Justin T. , Ficklin Darren L. 
Published: January 2020

AbstractBias correction, while widely used with climate‐model output, is not typically applied to paleoclimatic reconstructions. While many reconstruction models have low average error, they still may contain bias, especially in the tails of distributions. Bias correction, used cautiously, can be a valuable procedure that alters interpretations of past events. Analyzing the iconic tree‐ring reconstruction of Upper Colorado River flow, we find that its probability distribution is markedly different from that of observed flow. Using quantile mapping to bias correct the reconstruction, we analyze the full reconstructed record and two events in particular: the 1100s megadrought and the early 1600s pluvial. Overall, bias correction made the 1100s megadrought, the largest in the 1,200+year record, even more extreme. After bias correction, the early 1600s pluvial marginally exceeds the early twentieth century pluvial in magnitude but not in duration. Overall, bias correction should be considered whenever paleoclimatic reconstructions are compared directly to observations.
Enhanced Carbon Uptake and Reduced Methane Emissions in a Newly Restored Wetland
Authors: Yang Hualei , Tang Jianwu , Zhang Chunsong , Dai Yuhang , Zhou Cheng , Xu Ping , Perry Danielle C. , Chen Xuechu 
Published: January 2020

AbstractWetlands play an important role in reducing global warming potential in response to global climate change. Unfortunately, due to the effects of human disturbance and natural erosion, wetlands are facing global extinction. It is essential to implement engineering measures to restore damaged wetlands. However, the carbon sink capacity of restored wetlands is unclear. We examined the seasonal change of greenhouse gas emissions in both restored wetland and natural wetland and then evaluated the carbon sequestration capacity of the restored wetland. We found that (1) the carbon sink capacity of the restored wetland showed clear daily and seasonal change, which was affected by light intensity, air temperature, and vegetation growth, and (2) the annual daytime (8–18 hr) sustained‐flux global warming potential was −11.23 ± 4.34 kg CO2 m−2 y−1, representing a much larger carbon sink than natural wetland (−5.04 ± 3.73 kg CO2 m−2 y−1) from April to December. In addition, the results showed that appropriate tidal flow management may help to reduce CH4 emission in wetland restoration. Thus, we proposed that the restored coastal wetland, via effective engineering measures, reliably acted as a large net carbon sink and has the potential to help mitigate climate change.
Metallic reflectors with notched RCS spectral signature using dielectric resonators
Authors: Alhaj Abbas A. , El‐Absi M. , Abuelhaija A. , Solbach K. , Kaiser T. 
Published: January 2020

Dielectric resonators are placed in front of the metallic plane plate and corner reflectors. Excitation of the resonant mode produces strong scattering of an incident plane wave which shows up as narrow notch in the mono‐static radar cross section (RCS) spectral signature at the resonance frequency. Experimental proof at V‐band is given with a corner reflector of centimetre size with spherical dielectric resonators of 0.8 mm diameter showing a notch at 64 GHz.
Radio frequency reliability studies of CMOS RF integrated circuits for ultra‐thin flexible packages
Authors: Mitra D. , Hamidi S.B. , Roy P. , Biswas C. , Biswas A. , Dawn D. 
Published: January 2020

This Letter presents for the first time radio frequency (RF) reliability studies of fully integrated CMOS RF integrated circuits (RFICs) for next generation wireless communication applications involving conformal bodies where wireless communication RFICs will be embedded on ultra‐thin flexible packages. As a test case, RF characteristics of a CMOS voltage‐controlled oscillator (VCO) chip with multiple die‐substrate thicknesses were measured and results are analysed. The CMOS VCO chip under study was designed and fabricated using 180 nm RF‐CMOS process. Reliability of performances of the VCO chips are characterised and results are compared before and after die thinning from 250 to 50, 35, and 25 μm, respectively. Critical RF performance parameters such as frequency of oscillation, output power, and phase noise are considered for analysis, respectively. All the dies are placed face‐up for probing on the top of a metal chuck with ground connection inside the micro‐chamber of a probe station. While the deviations of frequency and output power are within ±1% and ±1 dB, respectively, due to the die thinning affect, the phase noise deteriorations are observed significant. It confirms the well‐known fact of phase noise sensitiveness to the substrate thickness due to the leakage and SOI CMOS is discussed widely to minimise these parasitic effects.
Low‐profile broadband aperture coupled magneto‐electric dipole array antenna for millimetre‐wave applications
Authors: Yang Guopeng , Zhang Jinping , Zhou Zhipeng 
Published: January 2020

This Letter presents a low‐profile broadband cavity‐backed magneto‐electric (ME) dipole antenna fed by a substrate integrated waveguide aperture. To reduce the antenna profile, a U‐shaped slot is etched on the electric dipole. Compared to the traditional ME dipole antenna whose profile is generally , the thickness of the proposed radiation structure is , where is the wavelength in the dielectric substrate. A array antenna with the proposed antenna as its element is then designed, simulated and fabricated. With the return loss is below −10 dB, a 19.1% (30.3–36.7 GHz) impedance bandwidth has been achieved. The radiation pattern of the proposed array antenna is quite stable, and the peak gain varies below 1 dB within the operating band.
Dual‐wideband dual‐polarised magnetoelectric dipole antenna for 4G/5G microcell base station
Authors: Zhu Congcong , Wang Bin , Luo Wei , Hao Honggang , Wang Ping 
Published: January 2020

A novel dual‐wideband dual‐polarised magnetoelectric (ME) dipole antenna for the fourth generation (4G)/fifth generation (5G) microcell base station is proposed. Using a pair of orthogonal ME dipoles and Γ‐shaped tapered cross feeding lines, the initial antenna achieves dual‐band and dual‐polarised. Then, four U‐shaped gaps, added in electric dipoles, effectively extend the lower impedance bandwidth. Finally, a circular parasitic patch with capacitive properties is innovatively loaded above the ME antenna, which obviously reduces the high‐resonant frequency from 5.5 to 4.9 GHz. Meanwhile, a box‐shaped reflector is employed to achieve stable gain and radiation patterns. As a result, the measured results show the good dual‐wideband performance of 52.4% (2.14–3.66 GHz) and 7.4% (4.68–5.04 GHz) with voltage standing wave ratio (VSWR) < 2, high isolation (>25 dB) and high gain (9.5 and 5.5 dBi, respectively). In addition, a stable radiation pattern with a half‐power beam width of and good cross‐polarisation discrimination (>20 dB) on the E‐plane is realised over these two bands.
300‐GHz integrated heterodyne receiver with carrier lock‐in Costas loop
Authors: Yi C. , Choi S.‐H. , Kim M. 
Published: January 2020

A carrier signal lock‐in experiment using a 300‐GHz integrated heterodyne circuit is presented. The circuit contains a single voltage‐controlled oscillator with a single set of quadrature mixers that are fabricated using 250‐nm InP double hetero‐junction bipolar transistor technology. An external feedback loop containing packaged baseband components such as amplifiers, a phase discriminator, and a filter is connected to the integrated circuit to form a complete receiver system. For a −25 dBm of input RF signal with 3.5‐GHz single‐tone carrier‐suppressed modulation, the receiver system responds with successful lock‐in range of 110 MHz centred around 311 GHz.
A parsec-scale wobbling jet in the high-synchrotron peaked blazar PG 1553+113
Authors: Lico R. , Liu J. , Giroletti M. , Orienti M. , Gómez J. L. , Piner B. G. , MacDonald N. R. , D’Ammando F. , Fuentes A. 
Published: January 2020

Context. The detection of quasi-periodic variability in active galactic nuclei in general, and in blazars in particular, is key to our understanding of the origin and nature of these objects as well as their cosmological evolution. PG 1553+113 is the first blazar showing an approximately two-year quasi-periodic pattern in its γ-ray light curve, which is also revealed at optical frequencies.
Aims. Such quasi-periodicity might have a geometrical origin, possibly related to the precessing nature of the jet, or could be intrinsic to the source and related to pulsational accretion flow instabilities. In this work we investigate and characterise the high-resolution radio emission properties of PG 1553+113 on parsec scales in order to differentiate between these different physical scenarios.
Methods. We monitored the source with the very long baseline array (VLBA) at 15, 24, and 43 GHz during an entire cycle of γ-ray activity in the period 2015–2017, with a cadence of about 2 months, both in total and polarised intensity. We constrained the jet position angle across the different observing epochs by investigating the total intensity ridge lines.
Results. We find a core-dominated source with a limb-brightened jet structure extending for ∼1.5 mas in the northeast direction whose position angle varies in time in the range ∼40°−60°. No clear periodic pattern can be recognized in the VLBA light curves during 2015–2017 or in the 15 GHz Owens Valley Radio Observatory light curve during the period 2008–2018. The core region polarisation percentage varies in the range ∼1−4%, and the polarisation angle varies from being roughly parallel to roughly transverse to the jet axis. We estimate a rotation measure value in the core region of ∼−1.0 ± 0.4 × 104 rad m−2. The brightness temperature (TB) is found to decrease as the frequency increases with an intrinsic value of ∼1.5 × 1010 K and the estimated Doppler factor is ∼1.4.
Conclusions. Although the jet wobbling motion indicates that geometrical effects can produce an enhanced emission through the Doppler boosting modulation, additional mechanisms are required in order to account for the quasi-periodic variability patterns observed in γ rays. The intrinsic TB value indicates that the total energy in the core region is dominated by the magnetic field.
A Comprehensive Tyrosine Phosphoproteomic Analysis Reveals Novel Components of the Platelet CLEC-2 Signaling Cascade
Authors: Izquierdo Irene , Barrachina María N. , Hermida-Nogueira Lidia , Casas Vanessa , Morán Luis A. , Lacerenza Serena , Pinto-Llorente Roberto , Eble Johannes A. , de los Ríos Vivian , Domínguez Eduardo , Loza María I. , Casal José Ignacio , Carrascal Montserrat , Abián Joaquín , García Angel 
Published: January 2020

AbstractC-type lectin-like receptor 2 (CLEC-2) plays a crucial role in different platelet-related physiological and pathological processes. It signals through a tyrosine kinase-mediated pathway that is highly dependent on the positive feedback exerted by the platelet-derived secondary mediators, adenosine diphosphate (ADP) and thromboxane A2 (TXA2). Here, we aimed to analyze the tyrosine phosphoproteome of platelets activated with the CLEC-2 agonist rhodocytin to identify relevant phosphorylated tyrosine residues (p-Tyr) and proteins involved in platelet activation downstream of this receptor. We identified 363 differentially p-Tyr residues, corresponding to the majority of proteins previously known to participate in CLEC-2 signaling and also novel ones, including adaptors (e.g., DAPP1, Dok1/3, CASS4, Nck1/2), kinases/phosphatases (e.g., FAK1, FES, FGR, JAK2, SHIP2), and membrane proteins (e.g., G6F, JAM-A, PECAM-1, TLT-1). To elucidate the contribution of ADP and TXA2 at different points of the CLEC-2 signaling cascade, we evaluated p-Tyr levels of residues identified in the analysis and known to be essential for the catalytic activity of kinases Syk(p-Tyr525+526) and Src(p-Tyr419), and for PLCγ2 activity (p-Tyr759). We demonstrated that Syk phosphorylation at Tyr525+526 also happens in the presence of ADP and TXA2 inhibitors, which is not the case for Src-pTyr419 and PLCγ2-pTyr759. Kinetics studies for the three phosphoproteins show some differences in the phosphorylation profile. Ca2+ mobilization assays confirmed the relevance of ADP and TXA2 for full CLEC-2-mediated platelet activation. The present study provides significant insights into the intracellular events that take place following CLEC-2 activation in platelets, contributing to elucidate in detail the CLEC-2 signalosome.
Reduced Plasma Magnesium Levels in Type-1 Diabetes Associate with Prothrombotic Changes in Fibrin Clotting and Fibrinolysis
Authors: Sobczak Amélie I. S. , Phoenix Fladia A. , Pitt Samantha J. , Ajjan Ramzi A. , Stewart Alan J. 
Published: January 2020

AbstractIndividuals with type-1 diabetes mellitus (T1DM) have a higher risk of thrombosis and low plasma magnesium concentrations. As magnesium is a known regulator of fibrin network formation, we investigated potential associations between fibrin clot properties and plasma magnesium concentrations in 45 individuals with T1DM and 47 age- and sex-matched controls without diabetes. Fibrin clot characteristics were assessed using a validated turbidimetric assay and associations with plasma magnesium concentration were examined. Plasma concentrations of fibrinogen, plasminogen activator inhibitor-1 (PAI-1), and lipids were measured and fibrin fiber diameters assessed using scanning electron microscopy. Fibrin clot maximum absorbance was unchanged in subjects with T1DM compared with controls, while lysis time was prolonged (p = 0.0273). No differences in fibrin fiber diameters or in lipid profile were observed between T1DM and controls. PAI-1 concentration was lower in the T1DM group compared with the controls (p = 0.0232) and positively correlated with lysis time (p = 0.0023). Plasma magnesium concentration was lower in the T1DM group compared with controls (p < 0.0001). Magnesium concentration negatively correlated with clot maximum absorbance (p = 0.0215) and lysis time (p = 0.0464). A turbidimetric fibrin clot lysis assay performed in a purified system that included PAI-1 and 0 to 3.2 mM Mg2+ showed a shortening of lysis time with increasing Mg2+ concentrations (p = 0.0004). Our findings reveal that plasma magnesium concentration is associated with changes in fibrin clot and lysis parameters.
Global shape of Toll activation is determined bywntDenhancer properties
Authors: Rahimi Neta , Carmon Shari , Averbukh Inna , Khajouei Farzaneh , Sinha Saurabh , Schejter Eyal D. , Barkai Naama , Shilo Ben-Zion 
Published: January 2020

SignificanceA central issue in robust patterning mediated by morphogens is how to buffer variability in morphogen distribution between embryos. We previously described a class of mechanisms that buffers variability through “distal pinning,” a global feedback mechanism that modulates the spread of the gradient and terminates only when morphogen values at a distal position reach some given, fixed level. We have previously shown inDrosophilaembryonic dorso-ventral patterning that the secreted WntD protein modulates Toll pathway activation. We have altered the wntD enhancer and demonstrate a global contraction of the Toll gradient. The demonstration of a direct link between the enhancer properties of the modulator gene and the morphogen activation profile establishes a molecular mechanism for buffering variability in morphogen distribution.
Beneficial Opioid Management Strategies: A Review of the Evidence for the use of Opioid Treatment Agreements
Authors: McAuliffe Staehler Tuesday M. , Palombi Laura C. 
Published: January 2020

Background: The Centers for Disease Control and Prevention (CDC) and American Society of Interventional Pain Physicians (ASIPP) guidelines recommend opioid treatment agreements to reduce the misuse and abuse of opioids, but evidence of their effectiveness has not been well-established. This controversy has led to their varied use in primary care settings. The purpose of this review is to collect studies that assess the value of opioid treatment agreements and associated opioid misuse outcomes in patients with chronic non-cancer pain. Methods: This study used a modified preferred reporting items for systematic reviews and meta-analyses (PRISMA) approach which is organized by five distinct elements or steps: beginning with a clearly formulated question, using the question to develop clear inclusion criteria to identify relevant studies, using an approach to appraise the studies or a subset of the studies, summarizing the evidence using an explicit methodology, and interpreting the findings of the review. Results: Of 283 articles identified, six eligible studies were evaluated and assessed for quality. The study design, setting, and participants varied across the studies evaluated, and the methods of measuring primary and secondary outcomes were also diverse across all studies. One study was a randomized clinical trial (RCT), four studies were retrospective cohort studies (RCS), and one study was a prospective cohort study (PCS). The design, methods, and indication for misuse of these studies contributed to quality scores of very low for one study, low for four studies, and moderate for one study. Conclusion: This systematic review shows weak evidence to support the effectiveness of patient prescriber agreements in the reduction and mitigation of opioid misuse and abuse. Further research is needed to determine if these agreements are beneficial as an opioid management strategy.