bluuebunny/crossref_metadata_2025 huggingface dataset:
The Use of a Jet Reference Frame to Analyze Drifter Trajectories in the Agulhas Current
Authors: d'Hotman Jethan Shaun , Malan Neil , Collins Charine , de Vos Marc , Lumpkin Rick , Morris Tamaryn , Hermes Juliet
Published: May 2019

Studies based on drifters that are deployed using fixed geographical locations can alias the variability in the Agulhas Current. Numerical model simulations have shown that tracking particles using jet coordinate systems will improve our understanding of the variability in western boundary currents. In this study we use in situ observations to show the potential of quasi‐Lagrangian measurements with an investigation into the relationship of the upstream surface velocity configuration and the trajectories surface drifters follow. Additionally, we use these drifters, along with ship‐based measurements, to expose biases in satellite‐derived geostrophic velocities in the Agulhas Current. Between September 1992 and October 2017, 49 surface drifters crossed the altimeter track #096 in a nonmeandering state. Of the 49 surface drifters, 16 crossed inshore of the surface velocity maxima, 3 of which leaked into the South Atlantic Ocean. Biases between altimetry‐derived geostrophic velocities and absolute velocities from ship acoustic Doppler current profiler and drifters measurements have pointed toward surface drifters leaking from inshore of the Agulhas Current core in a region of high shear. However, the bias between these velocities is inconsistent, with the highest range in bias found inshore of the Agulhas Current core. Due to the lack of data in the Agulhas Current and various sources of error, much work remains to be done and results presented here may provide motivation for further targeted drifter deployments in the future.
Global Warming Increases the Incidence of Haze Days in China
Authors: Xu Bing , Gu Zhaoyan , Wang Luo , Hao Qingzhen , Wang Haizhi , Chu Guoqiang , Lv Yanwu , Jiang Dabang
Published: May 2019

Both wind strength and anthropogenic emissions have been assumed to be the dominant factors in determining the occurrence of hazy weather in China. However, few records are available with sufficient temporal length and resolution, which enable the two signals to be separated, and hence address the dynamics of haze days and the global impact of the anthropogenic emissions in China, particularly in the context of global warming. Here we present the first long‐term (last ~180 years) lake sediment records of changes in wind strength and atmospheric loading of anthropogenic emissions in China. Our results show that the atmospheric loading of anthropogenic emissions and haze formation are closely related to the changes in wind strength associated with temperature changes, which are likely forced by tropical sea surface temperature. Comparison of our results with Pb isotope records from Japan and with the record of Pb concentrations in Greenland ice core indicates that the anthropogenic pollutants emitted in China stagnate mainly over the source area and neighboring regions, which thus favors haze formation under a warming climate. However, they would be transported worldwide under conditions of strong winds and decreased temperature. Climatic warming, together with the periodic changes in temperature, has caused unprecedented heavy haze days in recent decades in China. The observed pattern of periodic temperature variations suggests that in the next ~30 years, wind strength will increase and thus reduce the incidence of haze days. However, this reduction may be attenuated by continued climatic warming as anthropogenic greenhouse gases emissions continue.
Relative Contributions of North and South Pacific Sea Surface Temperature Anomalies to ENSO
Authors: Ding Ruiqiang , Tseng Yu‐heng , Li Jianping , Sun Cheng , Xie Fei , Hou Zhaolu
Published: May 2019

Variations in the sea surface temperature (SST) field in both the North Pacific (represented by the Victoria mode [VM]) and the South Pacific (represented by the South Pacific quadrapole [SPQ] mode) are related to the state of the El Niño–Southern Oscillation (ENSO) three seasons later. Here with the aid of observational data and numerical experiments, we demonstrate that both VM and SPQ SST forcing can influence the development of ENSO events through a similar air‐sea coupling mechanism. By comparing ENSO amplitudes induced by the VM and SPQ, as well as the percentages of strong ENSO events followed by the VM and SPQ events, we find that the VM and SPQ make comparable contributions and therefore have similar levels of importance to ENSO. Additional analysis indicates that although VM or SPQ SST forcing alone may serve as a good predictor for ENSO events, it is more effective to consider their combined influence. A prediction model based on both VM and SPQ indices is developed, which is capable of yielding skillful forecasts for ENSO at lead times of three seasons.
Is the Southern Ocean Getting Greener?
Authors: Del Castillo Carlos E. , Signorini Sergio R. , Karaköylü Erdem M. , Rivero‐Calle Sara
Published: May 2019

The Southern Ocean is a key player in regulating the planet's biogeochemistry, productivity, and climate. Ocean color data from two National Aeronautics and Space Administration satellites show statistically significant increases in the concentration of chlorophyll in all sectors of the Southern Ocean, particularly in the Sub‐Antarctic Zone and Permanently Open Ocean Zone. The smallest changes were observed in the Atlantic and Pacific sectors of the Sub‐Tropical Zone. These trends seem accentuated by higher chlorophyll concentrations during the austral winter. Increases in the annual and wintertime chlorophyll concentrations can have implications for the Southern Ocean biological pump and ocean productivity and higher trophic levels.
Statistical Characteristics of Ionospheric Hiss Waves
Authors: Xia Zhiyang , Chen Lunjin , Zhima Zeren , Santolík Ondrej , Horne Richard B. , Parrot Michel
Published: May 2019

In this study, we use the observations of electromagnetic waves by Detection of Electromagnetic Emissions Transmitted from Earthquake Regions satellite to investigate propagation characteristics of low‐altitude ionospheric hiss. In an event study, intense hiss wave power is concentrated over a narrow frequency band with a central frequency that decreases as latitude decreases, which coincides to the variation of local proton cyclotron frequency fCH. The wave propagates obliquely to the background magnetic field and equatorward from high latitude region. We use about ∼6 years of observations to statistically study the dependence of ionospheric hiss wave power on location, local time, geomagnetic activity, and season. The results demonstrate that the ionospheric hiss power is stronger on the dayside than nightside, under higher geomagnetic activity conditions, in local summer than local winter. The wave power is confined near the region where the local fCH is equal to the wave frequency. A ray tracing simulation is performed to account for the dependence of wave power on frequency and latitude.
Effects of the Hall Conductivity in Ionospheric Heating Experiments
Authors: Tulegenov B. , Streltsov A. V.
Published: May 2019

We investigate the role of Hall conductivity in ionospheric heating experiments. Ionospheric heating by powerful X‐mode waves changes the Hall and Pedersen conductances in the E and D regions, which lead to the generation of ultra‐low frequency (ULF)/extremely‐low frequency/very low frequency waves, when the electric field exists in the ionosphere. The importance of the Hall currents in the magnetosphere‐ionosphere interactions, carried by ULF waves and field‐aligned currents, has been consistently overlooked in studies devoted to the active experiments. Simulations of the three‐dimensional two‐fluid magnetohydrodynamic (MHD) model, presented in this paper, demonstrate that the Hall conductivity changes (1) the growth rate and the amplitude of ULF waves generated by the heating and (2) the orientation and the direction of propagation of the generated waves. These findings provide insight in the experiments where the waves were generated with a geometric modulation technique and suggest a new and more efficient approach for conducting such experiments in the future.
Analytical Propagation of Runoff Uncertainty Into Discharge Uncertainty Through a Large River Network
Authors: David Cédric H. , Hobbs Jonathan M. , Turmon Michael J. , Emery Charlotte M. , Reager John T. , Famiglietti James S.
Published: May 2019

The transport of freshwater from continents to oceans through rivers has traditionally been estimated by routing runoff from land surface models within river models to obtain discharge. This paradigm imposes that errors are transferred from runoff to discharge, yet the analytical propagation of uncertainty from runoff to discharge has never been derived. Here we apply statistics to the continuity equation within a river network to derive two equations that propagate the mean and variance/covariance of runoff errors independently. We validate these equations in a case study of the rivers in the western United States and, for the first time, invert observed discharge errors for spatially distributed runoff errors. Our results suggest that the largest discharge error source is the joint variability of runoff errors across space, not the mean or amplitude of individual errors. Our findings significantly advance the science of error quantification in model‐based estimates of river discharge.
Generation of EMIC Waves and Effects on Particle Precipitation During a Solar Wind Pressure Intensification With Bz>0
Authors: Lessard Marc R. , Paulson Kristoff , Spence Harlan E. , Weaver Carol , Engebretson Mark J. , Millan Robyn , Woodger Leslie , Halford Alexa , Horne Richard , Rodger Craig J. , Hendry Aaron
Published: May 2019

During geomagnetic storms, some fraction of the solar wind energy is coupled via reconnection at the dayside magnetopause, a process that requires a southward interplanetary magnetic field Bz. Through a complex sequence of events, some of this energy ultimately drives the generation of electromagnetic ion cyclotron (EMIC) waves, which can then scatter energetic electrons and ions from the radiation belts. In the event described in this paper, the interplanetary magnetic field remained northward throughout the event, a condition unfavorable for solar wind energy coupling through low‐latitude reconnection. While this resulted in SYM/H remaining positive throughout the event (so this may not be considered a storm, in spite of the very high solar wind densities), pressure fluctuations were directly transferred into and then propagated throughout the magnetosphere, generating EMIC waves on global scales. The generation mechanism presumably involved the development of temperature anisotropies via perpendicular pressure perturbations, as evidenced by strong correlations between the pressure variations and the intensifications of the waves globally. Electron precipitation was recorded by the Balloon Array for RBSP Relativistic Electron Losses balloons, although it did not have the same widespread signatures as the waves and, in fact, appears to have been quite patchy in character. Observations from Van Allen Probe A satellite (at postmidnight local time) showed clear butterfly distributions, and it may be possible that the EMIC waves contributed to the development of these distribution functions. Ion precipitation was also recorded by the Polar‐orbiting Operational Environmental Satellite satellites, though tended to be confined to the dawn‐dusk meridians.
Dynamic Intermediate Waters Across the Late Glacial Revealed by Paired Radiocarbon and Clumped Isotope Temperature Records
Authors: Hines Sophia K. V. , Eiler John M. , Southon John R. , Adkins Jess F.
Published: May 2019

Paired radiocarbon and clumped isotope temperature records from U/Th‐dated Desmophyllum dianthus corals in the North Atlantic and Southern Ocean provide unique information about the history of intermediate waters (∼1,500–1,700 m) across the late glacial and deglaciation (∼35–10 ka). These measurements allow for the construction of radiocarbon‐temperature crossplots, which help to identify water mass endmembers at different times across the deglaciation. Radiocarbon and temperature values from the late glacial fall outside the range of modern ocean data from near the sample collection sites. In the North Atlantic, radiocarbon values tend to be much older than the modern, while in the Southern Ocean, they are more often younger than the modern. Reconstructed temperatures vary around respective modern ocean values; however, warm waters are observed at the Last Glacial Maximum and across the deglaciation in the north and south. We interpret our data in the context of the modern hydrography of the Western North Atlantic and Southern Ocean, and we draw upon direct comparisons between sediment core‐derived reconstructions of ocean circulation from the South Indo‐Pacific and our deep‐sea coral data from the Southern Ocean. Our North Atlantic data support accepted patterns of reduced North Atlantic Deep Water formation during Heinrich Stadials 1 and 2. In the Southern Ocean, deep‐sea coral populations respond to changes in ocean structure that are also reflected in a depth profile of δ13C data from New Zealand, and data indicate that there was less influence of Pacific Deep Water between 1,500 and 1,700 m south of Tasmania across much of the deglaciation.
Strategic-tuning of radiative excitons for efficient and stable fluorescent white organic light-emitting diodes
Authors: Wu Zhongbin , Liu Yuan , Yu Ling , Zhao Chenyang , Yang Dezhi , Qiao Xianfeng , Chen Jiangshan , Yang Chuluo , Kleemann Hans , Leo Karl , Ma Dongge
Published: May 2019

The emerging thermally activated delayed fluorescence materials have great potential for efficiencies in organic light-emitting diodes by optimizing molecular structures of the emitter system. However, it is still challenging in the device structural design to achieve high efficiency and stable device operation in white organic light-emitting diodes. Here we propose a universal design strategy for thermally activated delayed fluorescence emitter-based fluorescent white organic light-emitting diodes, establishing an advanced system of “orange thermally activated delayed fluorescence emitter sensitized by blue thermally activated delayed fluorescence host” combined with an effective exciton-confined emissive layer. Compared to reference single-layer and double-layer emissive devices, the external quantum efficiency improves by 31 and 45%, respectively, and device operational stability also shows nearly fivefold increase. Additionally, a detailed optical simulation for the present structure is made, indicating the validity of the design strategy in the fluorescent white organic light-emitting diodes.
Physical origin of giant excitonic and magneto-optical responses in two-dimensional ferromagnetic insulators
Authors: Wu Meng , Li Zhenglu , Cao Ting , Louie Steven G.
Published: May 2019

The recent discovery of magnetism in atomically thin layers of van der Waals crystals has created great opportunities for exploring light–matter interactions and magneto-optical phenomena in the two-dimensional limit. Optical and magneto-optical experiments have provided insights into these topics, revealing strong magnetic circular dichroism and giant Kerr signals in atomically thin ferromagnetic insulators. However, the nature of the giant magneto-optical responses and their microscopic mechanism remain unclear. Here, by performing first-principlesGWand Bethe-Salpeter equation calculations, we show that excitonic effects dominate the optical and magneto-optical responses in the prototypical two-dimensional ferromagnetic insulator, CrI3. We simulate the Kerr and Faraday effects in realistic experimental setups, and based on which we predict the sensitive frequency- and substrate-dependence of magneto-optical responses. These findings provide physical understanding of the phenomena as well as potential design principles for engineering magneto-optical and optoelectronic devices using two-dimensional magnets.
Curvature induction and membrane remodeling by FAM134B reticulon homology domain assist selective ER-phagy
Authors: Bhaskara Ramachandra M. , Grumati Paolo , Garcia-Pardo Javier , Kalayil Sissy , Covarrubias-Pinto Adriana , Chen Wenbo , Kudryashev Mikhail , Dikic Ivan , Hummer Gerhard
Published: May 2019

FAM134B/RETREG1 is a selective ER-phagy receptor that regulates the size and shape of the endoplasmic reticulum. The structure of its reticulon-homology domain (RHD), an element shared with other ER-shaping proteins, and the mechanism of membrane shaping remain poorly understood. Using molecular modeling and molecular dynamics (MD) simulations, we assemble a structural model for the RHD of FAM134B. Through MD simulations of FAM134B in flat and curved membranes, we relate the dynamic RHD structure with its two wedge-shaped transmembrane helical hairpins and two amphipathic helices to FAM134B functions in membrane-curvature induction and curvature-mediated protein sorting. FAM134B clustering, as expected to occur in autophagic puncta, amplifies the membrane-shaping effects. Electron microscopy of in vitro liposome remodeling experiments support the membrane remodeling functions of the different RHD structural elements. Disruption of the RHD structure affects selective autophagy flux and leads to disease states.
A few Ascomycota taxa dominate soil fungal communities worldwide
Authors: Egidi Eleonora , Delgado-Baquerizo Manuel , Plett Jonathan M. , Wang Juntao , Eldridge David J. , Bardgett Richard D. , Maestre Fernando T. , Singh Brajesh K.
Published: May 2019

Despite having key functions in terrestrial ecosystems, information on the dominant soil fungi and their ecological preferences at the global scale is lacking. To fill this knowledge gap, we surveyed 235 soils from across the globe. Our findings indicate that 83 phylotypes (<0.1% of the retrieved fungi), mostly belonging to wind dispersed, generalist Ascomycota, dominate soils globally. We identify patterns and ecological drivers of dominant soil fungal taxa occurrence, and present a map of their distribution in soils worldwide. Whole-genome comparisons with less dominant, generalist fungi point at a significantly higher number of genes related to stress-tolerance and resource uptake in the dominant fungi, suggesting that they might be better in colonising a wide range of environments. Our findings constitute a major advance in our understanding of the ecology of fungi, and have implications for the development of strategies to preserve them and the ecosystem functions they provide.
Emerging therapies for cartilage regeneration in currently excluded ‘red knee’ populations
Authors: Martín Anthony R. , Patel Jay M. , Zlotnick Hannah M. , Carey James L. , Mauck Robert L.
Published: May 2019

The field of articular cartilage repair has made significant advances in recent decades; yet current therapies are generally not evaluated or tested, at the time of pivotal trial, in patients with a variety of common comorbidities. To that end, we systematically reviewed cartilage repair clinical trials to identify common exclusion criteria and reviewed the literature to identify emerging regenerative approaches that are poised to overcome these current exclusion criteria. The term “knee cartilage repair” was searched on clinicaltrials.gov. Of the 60 trials identified on initial search, 33 were further examined to extract exclusion criteria. Criteria excluded by more than half of the trials were identified in order to focus discussion on emerging regenerative strategies that might address these concerns. These criteria included age (<18 or >55 years old), small defects (<1 cm2), large defects (>8 cm2), multiple defect (>2 lesions), BMI >35, meniscectomy (>50%), bilateral knee pathology, ligamentous instability, arthritis, malalignment, prior repair, kissing lesions, neurologic disease of lower extremities, inflammation, infection, endocrine or metabolic disease, drug or alcohol abuse, pregnancy, and history of cancer. Finally, we describe emerging tissue engineering and regenerative approaches that might foster cartilage repair in these challenging environments. The identified criteria exclude a majority of the affected population from treatment, and thus greater focus must be placed on these emerging cartilage regeneration techniques to treat patients with the challenging “red knee”.
Transcript expression profiling in two contrasting cultivars and molecular cloning of a SKP-1 like gene, a component of SCF-ubiquitin proteasome system from mungbean Vigna radiate L.
Authors: Bharadwaj Nandita , Barthakur Sharmistha , Biswas Akash Deep , Kumar Das Monoj , Kour Manpreet , Ramteke Anand , Gogoi Nirmali
Published: May 2019

Protein degradation and turnover under various environmental stresses is basically regulated by ubiquitin-proteasome system (UPS), of which SKP1 is a very essential component. Isolation and cloning of an identified potential stress responsive candidate gene SKP1, was successfully done for the first time to fathom the role of SKP1 in drought tolerance at genetic level in drought tolerant mungbean cultivar Pratap, which was screened after a detailed physio-biochemical screening amongst seven popular mungbean cultivars. The cloned gene SKP1 (accession number KX881912) is 550 bp in length, encodes 114 amino acids. It shows high sequence homology with SKP1 from Zea mays (NP_001148633). The protein expression of isolated SKP1 was confirmed by GUS fused expression using a Histochemical assay under control as well as under drought stress. Further, up-regulation in relative expression level of SKP1 in different plant parts under drought stress confirmed its utility as a potential drought responsive candidate gene certainly demanding extensive genetic research for further incorporation in breeding programs. Moreover, the structure of VrSKP1 (Vigna radiata SKP1) has been modelled, validated and an Essential Dynamics (ED) was done on the Molecular Dynamics (MD) simulation trajectories for filtering large-scale concerted motions. Free-energy calculations on the ED revealed a complex free-energy landscape (FEL) implying the conformational diversity of the modelled VrSPK1 protein.
Integrate CRISPR/Cas9 for protein expression of HLA-B*38:68Q via precise gene editing
Authors: Yin Yuxin , Reed Elaine F. , Zhang Qiuheng
Published: May 2019

The determination of null- or low-expressed HLA alleles is clinically relevant in both hematopoietic stem cell transplantation and solid organ transplantation. We studied the expression level of a questionable (Q)HLA-B*38:68Qallele, which carries a 9-nucleotide (nt) deletion at codon 230–232 in exon 4 ofHLA-B*38:01:01:01using CRISPR/Cas9 gene editing technology. CRISPR/Cas9 gene editing ofHLA-B*38:01:01:01homozygous EBV B cell line resulted in oneHLA-B*38:68Q/B*38:01:01:01heterozygous and oneHLA-B*38:68Qhomozygous clone. Flow cytometric analysis of monoclonal anti-Bw4 antibody showed the protein expression ofHLA-B*38:01:01:01in homozygous cells was 2.2 fold higher thanHLA-B*38:68Q/B*38:01:01:01heterozygous cells, and the expression ofHLA-B*38:68Q/B*38:01:01:01heterozygous cells was over 2.0 fold higher thanHLA-B*38:68Qhomozygous cells. TheHLA-B*38:68Qexpression was further confirmed using anti-B38 polyclonal antibody. Similarly, the expression of theHLA-B*38:01:01:01homozygous cells was 1.5 fold higher than that ofHLA-B*38:68Q/B*38:01:01:01heterozygous cells, and theHLA-B*38:68Q/B*38:01:01:01heterozygous cells was over 1.6 fold higher than that ofHLA-B*38:68Qhomozygous cells. The treatment ofHLA-B*38:68Qhomozygous cells with IFN-γ significantly increased its expression. In conclusion, we demonstrate thatHLA-B*38:68Qis a low-expressing HLA allele. The CRISPR/Cas9 technology is a useful tool to induce precise gene editing in HLA genes to enable the characterization of HLA gene variants on expression and function.
Liver MR relaxometry at 3T – segmental normal T1 and T2* values in patients without focal or diffuse liver disease and in patients with increased liver fat and elevated liver stiffness
Authors: Obmann V. C. , Mertineit N. , Marx C. , Berzigotti A. , Ebner L. , Heverhagen J. T. , Christe A. , Huber A. T.
Published: May 2019

Magnetic resonance (MR) T1 and T2* mapping allows quantification of liver relaxation times for non-invasive characterization of diffuse liver disease. We hypothesized that liver relaxation times are not only influenced by liver fibrosis, inflammation and fat, but also by air in liver segments adjacent to the lung – especially in MR imaging at 3T. A total of 161 study participants were recruited, while 6 patients had to be excluded due to claustrophobia or technically uninterpretable MR elastography. Resulting study population consisted of 12 healthy volunteers and 143 patients who prospectively underwent multiparametric MR imaging at 3T. Of those 143 patients, 79 had normal liver stiffness in MR elastography (shear modulus <2.8 kPa, indicating absence of fibrosis) and normal proton density fat fraction (PDFF < 10%, indicating absence of steatosis), defined as reference population. T1 relaxation times in these patients were significantly shorter in liver segments adjacent to the lung than in those not adjacent to the lung (p < 0.001, mean of differences 33 ms). In liver segments not adjacent to the lung, T1 allowed to differentiate significantly between the reference population and patients with steatosis and/or fibrosis (p ≤ 0.011), while there was no significant difference of T1 between the reference population and healthy volunteers. In conclusion, we propose to measure T1 relaxation times in liver segments not adjacent to the lung. Otherwise, we recommend taking into account slightly shorter T1 values in liver segments adjacent to the lung.
Very- and ultra-long-period seismic signals prior to and during caldera formation on La Réunion Island
Authors: Fontaine F. R. , Roult G. , Hejrani B. , Michon L. , Ferrazzini V. , Barruol G. , Tkalčić H. , Di Muro A. , Peltier A. , Reymond D. , Staudacher T. , Massin F.
Published: May 2019

Early detection of the onset of a caldera collapse can provide crucial information to understand their formation and thus to minimize risks for the nearby population and visitors. Here, we analyse the 2007 caldera collapse of Piton de la Fournaise on La Réunion Island recorded by a broadband seismic station. We show that this instrument recorded ultra-long period (ULP) signals with frequencies in the range (0.003–0.01 Hz) accompanied by very-long period (VLP) signals (between 0.02 and 0.50 Hz) prior to and during the caldera formation suggesting it is possible to detect the beginning of the collapse at depth and anticipate its surface formation. Interestingly, VLP wave packets with a similar duration of 20 s are identified prior to and during the caldera formation. We propose that these events could result from repeating piston-like successive collapses occurring through a ring-fault structure surrounding a magma reservoir from the following arguments: the source mechanism from the main collapse, the observations of slow source processes as well as observations from the field and the characteristic ring-fault seismicity.
Improving the foundation for particulate matter risk assessment by individual nanoparticle statistics from electron microscopy analysis
Authors: Brostrøm Anders , Kling Kirsten Inga , Koponen Ismo Kalevi , Hougaard Karin Sørig , Kandler Konrad , Mølhave Kristian
Published: May 2019

Air pollution is one of the major contributors to the global burden of disease, with particulate matter (PM) as one of its central concerns. Thus, there is a great need for exposure and risk assessments associated with PM pollution. However, current standard measurement techniques bring no knowledge of particle composition or shape, which have been identified among the crucial parameters for toxicology of inhaled particles. We present a method for collecting aerosols via impaction directly onto Transmission Electron Microscopy (TEM) grids, and based on the measured impactor collection efficiency and observed impact patterns we establish a reproducible imaging routine for automated Scanning Electron Microscopy (SEM) analysis. The method is validated by comparison to scanning mobility particle sizer (SMPS) measurements, where a good agreement is found between the particle size distributions (PSD), ensuring a representative description of the sampled aerosol. We furthermore determine sampling conditions for achieving optimal particle coverage on the TEM grids, allowing for a statistical analysis. In summary, the presented method can provide not only a representative PSD, but also detailed statistics on individual particle geometries. If coupled with Energy-dispersive X-ray spectroscopy (EDS) analysis elemental compositions can be assessed as well. This makes it possible to categorize particles both according to size and shape e.g. round and fibres, or agglomerates, as well as classify them based on their elemental composition e.g. salt, soot, or metals. Combined this method brings crucial knowledge for improving the foundation for PM risk assessments on workplaces and in ambient conditions with complex aerosol pollution.
Retinol binding protein 4 abundance in plasma and tissues is related to body fat deposition in cattle
Authors: Liu Yinuo , Albrecht Elke , Dannenberger Dirk , Hammon Harald M. , Kuehn Christa , Sauerwein Helga , Yang Runjun , Zhao Zhihui , Maak Steffen
Published: May 2019

Retinol binding protein 4 (RBP4) facilitates the transport of retinol in the body but is also an adipokine and fatty acid transporter. Our study was aimed at investigating the associations between RBP4 abundance and fat deposition in cattle. Blood samples of 246 crossbred bulls were taken at 8 months of age and at slaughter at 18 months of age for the determination of RBP4, hormone levels, and fatty acid composition. Significant correlations between plasma RBP4 abundance at 8 months of age and carcass traits at 18 months of age were detected (e.g., r = 0.3; P < 0.001 to carcass fat). Furthermore, RBP4 abundances in the plasma and subcutaneous fat were higher (P < 0.05) in bulls with increased fat deposition, whereas the liver RBP4 expression was not (P > 0.05). Retinol binding protein 4 was immunohistochemically localized in or close to adipocytes within muscle and adipose tissue and in liver stellate cells but not in hepatocytes. Overall, our results indicate that increased RBP4 levels were associated with increased fat deposition and altered fatty acid composition, but not with altered glucose tolerance, in crossbred bulls. Moreover, our results suggest that adipose-tissue-derived RBP4 may contribute to the circulating RBP4 level.
Plasmonic colours predicted by deep learning
Authors: Baxter Joshua , Calà Lesina Antonino , Guay Jean-Michel , Weck Arnaud , Berini Pierre , Ramunno Lora
Published: May 2019

Picosecond laser pulses have been used as a surface colouring technique for noble metals, where the colours result from plasmonic resonances in the metallic nanoparticles created and redeposited on the surface by ablation and deposition processes. This technology provides two datasets which we use to train artificial neural networks, data from the experiment itself (laser parameters vs. colours) and data from the corresponding numerical simulations (geometric parameters vs. colours). We apply deep learning to predict the colour in both cases. We also propose a method for the solution of the inverse problem – wherein the geometric parameters and the laser parameters are predicted from colour – using an iterative multivariable inverse design method.
Laparoscopic uterine graft procurement and surgical autotransplantation in ovine model
Authors: Sánchez-Margallo Francisco Miguel , Moreno-Naranjo Belén , Pérez-López María del Mar , Abellán Elena , Domínguez-Arroyo José Antonio , Mijares José , Álvarez Ignacio Santiago
Published: May 2019

Currently, uterus transplantation (UTx) is a clinical option for infertile women. Over the past three decades, treating benign or malignant gynecological diseases with minimally invasive gynecological surgery has improved, providing significant advantages over conventional open surgery. This study addresses the method used for laparoscopic live-donor ovariohysterectomy and graft harvest from a sheep model. Using a microsurgical practice, ten grafts were autotransplanted after uterine perfusion. End-to-end anastomosis techniques were used to approximate veins and arteries. Follow-ups were carried out 2-months after surgery and postoperative studies included ultrasound scan, diagnostic hysteroscopy, vascular angiography, and exploratory laparoscopy. All transplants were completed without complications. After vascular anastomosis, total reperfusion of the tissue was accomplished in all animals without confirmation of arterial or venous thrombosis. Angiographic explorations did not show any statistically significant dissimilarity in the arterial diameters between the different examination times. 3-months after uterine transplantation all animals underwent assisted reproduction techniques. Patent uterine arteries were observed 4, 8 and 12 months after the transplant. 6-months after transplantation, six sheep (60%) became pregnant with assisted reproduction practices. We noticed an increase in the degree of fibrosis of the cervix samples in non-pregnant animals of the transplant group. Laparoscopic surgery can be an advantageous approach for the uterus retrieval procedure during uterine transplantation. However, larger sample sized reports are needed in order to accomplish validation, standardization and wider use of this route.
Visual modelling supports the potential for prey detection by means of diurnal active photolocation in a small cryptobenthic fish
Authors: Bitton Pierre-Paul , Yun Christmann Sebastian Alejandro , Santon Matteo , Harant Ulrike K. , Michiels Nico K.
Published: May 2019

Active sensing has been well documented in animals that use echolocation and electrolocation. Active photolocation, or active sensing using light, has received much less attention, and only in bioluminescent nocturnal species. However, evidence has suggested the diurnal triplefin Tripterygion delaisi uses controlled iris radiance, termed ocular sparks, for prey detection. While this form of diurnal active photolocation was behaviourally described, a study exploring the physical process would provide compelling support for this mechanism. In this paper, we investigate the conditions under which diurnal active photolocation could assist T. delaisi in detecting potential prey. In the field, we sampled gammarids (genus Cheirocratus) and characterized the spectral properties of their eyes, which possess strong directional reflectors. In the laboratory, we quantified ocular sparks size and their angle-dependent radiance. Combined with environmental light measurements and known properties of the visual system of T. delaisi, we modeled diurnal active photolocation under various scenarios. Our results corroborate that diurnal active photolocation should help T. delaisi detect gammarids at distances relevant to foraging, 4.5 cm under favourable conditions and up to 2.5 cm under average conditions. To determine the prevalence of diurnal active photolocation for micro-prey, we encourage further theoretical and empirical work.
Real-Time Observation of Carbon Oxidation by Driven Motion of Catalytic Ceria Nanoparticles within Low Pressure Oxygen
Authors: Li Boyu , Sediako Anton D. , Zhao Pei , Li Jingde , Croiset Eric , Thomson Murray J. , Wen John Z.
Published: May 2019

Carbon particulate matter (PM) is an undesirable aerosol pollutant formed from combustors such as power plants, refineries, and engines. The most common and effective method of mitigating PM emission is the capture of particulates using a filter, before particles are released into the atmosphere. In order to develop and improve advanced filtering materials, a better understanding is required of their chemical and mechanical behavior. We report on a novel phenomenon on the mobility and oxidation behavior of catalytic iron doped ceria nanoparticles in contact with mobile carbon black nanoparticles. The process is recorded by real time imaging within an environmental transmission electron microscope. In contrast to observations in previous studies, the separated ceria nanoparticles are found to actively move on the substrate and consume the connecting carbon particles one-by-one. The velocity of particle motion is correlated to the reaction temperature and oxygen pressure, both determining the reaction rate. Modeling using the Density Functional Theory suggests this motion is driven by the chemical bonding between the surface oxygen of the catalyst and the graphite layers of carbon black, initiated through the Van der Waals force between two types of nanoparticles.
Annual Thermal Stress Increases a Soft Coral’s Susceptibility to Bleaching
Authors: Slattery Marc , Pankey M. Sabrina , Lesser Michael P.
Published: May 2019

Like scleractinian corals, soft corals contain photosymbionts (Family Symbiodiniaceae) that provide energy for the host. Recent thermal events have resulted in soft coral bleaching in four of five years on Guam, where they dominated back-reef communities. Soft coral bleaching was examined in Sinularia maxima, S. polydactyla, and their hybrid S. maxima x polydactyla. Results from annual field surveys indicated that S. maxima and the hybrid were more susceptible to bleaching than S. polydactyla, and this was related to differences in their Symbiodiniaceae communities in 2016 and 2017. The photosymbionts of S. polydactyla were apparently more stress tolerant and maintained higher photosynthetic potential through three years of bleaching, in contrast to the other species that exhibited a decline in photosynthetic potential after the first year of bleaching. Nonetheless, by the 2017 bleaching event all soft coral populations exhibited significant bleaching-mediated declines and loss of photosynthetic efficiency suggesting a declining resiliency to annual thermal stress events. While S. polydactyla initially looked to succeed the other species as the dominant space occupying soft coral on Guam back-reefs, cumulative bleaching events ultimately turned this “winner” into a “loser”, suggesting the trajectory for coral reefs is towards continued loss of structure and function.
Improved drought stress tolerance in Arabidopsis by CRISPR/dCas9 fusion with a Histone AcetylTransferase
Authors: Roca Paixão Joaquin Felipe , Gillet François-Xavier , Ribeiro Thuanne Pires , Bournaud Caroline , Lourenço-Tessutti Isabela Tristan , Noriega Daniel D. , Melo Bruno Paes de , de Almeida-Engler Janice , Grossi-de-Sa Maria Fatima
Published: May 2019

Drought episodes decrease plant growth and productivity, which in turn cause high economic losses. Plants naturally sense and respond to water stress by activating specific signalling pathways leading to physiological and developmental adaptations. Genetically engineering genes that belong to these pathways might improve the drought tolerance of plants. The abscisic acid (ABA)-responsive element binding protein 1/ABRE binding factor (AREB1/ABF2) is a key positive regulator of the drought stress response. We investigated whether the CRISPR activation (CRISPRa) system that targets AREB1 might contribute to improve drought stress tolerance in Arabidopsis. Arabidopsis histone acetyltransferase 1 (AtHAT1) promotes gene expression activation by switching chromatin to a relaxed state. Stable transgenic plants expressing chimeric dCas9HAT were first generated. Then, we showed that the CRISPRa dCas9HAT mechanism increased the promoter activity controlling the β-glucuronidase (GUS) reporter gene. To activate the endogenous promoter of AREB1, the CRISPRa dCas9HAT system was set up, and resultant plants showed a dwarf phenotype. Our qRT-PCR experiments indicated that both AREB1 and RD29A, a gene positively regulated by AREB1, exhibited higher gene expression than the control plants. The plants generated here showed higher chlorophyll content and faster stomatal aperture under water deficit, in addition to a better survival rate after drought stress. Altogether, we report that CRISPRa dCas9HAT is a valuable biotechnological tool to improve drought stress tolerance through the positive regulation of AREB1.
Vitamin D and Wnt3A have additive and partially overlapping modulatory effects on gene expression and phenotype in human colon fibroblasts
Authors: Ferrer-Mayorga Gemma , Niell Núria , Cantero Ramón , González-Sancho José Manuel , del Peso Luis , Muñoz Alberto , Larriba María Jesús
Published: May 2019

The Wnt/β-catenin signalling pathway is essential for intestinal epithelium homeostasis, but its aberrant activation is a hallmark of colorectal cancer (CRC). Several studies indicate that the bioactive vitamin D metabolite 1α,25-dihydroxyvitamin D3 (1,25(OH)2D3) inhibits proliferation and promotes epithelial differentiation of colon carcinoma cells in part through antagonism of the Wnt/β-catenin pathway. It is now accepted that stromal fibroblasts are crucial in healthy and pathologic intestine: pericryptal myofibroblasts are constituents of the stem cell niche and cancer-associated fibroblasts (CAFs) contribute to CRC progression. However, studies on the combined action of 1,25(OH)2D3 and Wnt factors in colon fibroblasts are lacking. Here we show by global transcriptomic studies that 1,25(OH)2D3 and Wnt3A have profound, additive, partially overlapping effects on the gene expression profile of CCD-18Co human colon myofibroblasts. Moreover, 1,25(OH)2D3 and Wnt3A inhibit CCD-18Co cell proliferation and migration, while 1,25(OH)2D3 reduces, but Wnt3A increases, their capacity to contract collagen gels (a marker of fibroblast activation). These data were largely confirmed in patient-derived primary colon normal fibroblasts and CAFs, and in fibroblasts from other origins. Our results indicate that 1,25(OH)2D3 and Wnt3A are strong regulators of colon fibroblast biology and contribute to a better knowledge of intestinal homeostasis and stromal fibroblast action in CRC.
Changes in the distribution of hydro-climatic extremes in a non-stationary framework
Authors: Ouarda Taha B. M. J. , Charron Christian
Published: May 2019

Hydro-climatic extremes are influenced by climate change and climate variability associated to large-scale oscillations. Non-stationary frequency models integrate trends and climate variability by introducing covariates in the distribution parameters. These models often assume that the distribution function and shape of the distribution do not change. However, these assumptions are rarely verified in practice. We propose here an approach based on L-moment ratio diagrams to analyze changes in the distribution function and shape parameter of hydro-climate extremes. We found that important changes occur in the distribution of annual maximum streamflow and extreme temperatures. Eventual relations between the shapes of the distributions of extremes and climate indices are also identified. We provide an example of a non-stationary frequency model applied to flood flows. Results show that a model with a shape parameter dependent on climate indices in combination with a scale parameter dependent on time improves significantly the goodness-of-fit.
Shell-type acoustic metasurface and arc-shape carpet cloak
Authors: Ma Fuyin , Xu Yicai , Wu Jiu Hui
Published: May 2019

We systematically propose a thin shell-type acoustic metasurface, which could be used to design a carpet cloak that closely covers an arc-shaped object, therefore providing the necessary support for hiding an object with any arbitrary shape. To facilitate the experimental measurement, however, the work here starts with some rotary spherical shell-type and ellipsoidal shell-type cell structures. The measured and calculated sound transmission loss (STL) results of these structures suggest that the sound insulation performances of the shell-type structure are quite different from those of the plate-type structure, indicating a possible break in the shape of the classical sound insulation curve. Considering also that cylindrical shell structures are more widely used in practice than the rotary shell structures, a number of two-dimensional bilayer cylindrical and elliptic cylindrical shell structures were, therefore, designed in this assay. Due to the asymmetry of the structure, the shell-type cells could exhibit bianisotropic sound absorption, reflection and effective parameters. Furthermore, the stiffness of the thin shell structure changed nonlinearly with the changing of the radius of curvature, with a wing shape tendency. In addition, a bilayer cylindrical shell-type acoustic metasurface and an arc-shaped carpet acoustic cloak were successively designed, wherein the phased compensation of differently shaped cell structures could be adjusted by means of a new engineering iso-phase design method. This work could provide the necessary guidance to extend existing results in the field of membrane- and plate-type acoustic metamaterials for shell-type structures, and the realization of the arc-shaped cloak could provide support for the design of a carpet acoustical cloak for use with arbitrary shapes.
Cathode coating using LiInO2-LiI composite for stable sulfide-based all-solid-state batteries
Authors: Kwak Hwan Wook , Park Yong Joon
Published: May 2019

All-solid-state batteries with inorganic solid electrolytes are ideal to overcome the safety issues related to the flammable organic electrolyte in lithium ion batteries. Sulfide materials are promising inorganic electrolytes due to their high ionic conductivity and good elasticity. Nevertheless, their application is limited by their high reactivity and instability at the cathode/electrolyte (Li[Ni0.8Co0.15Al0.05]O2/75Li2S–22P2S5–3Li2SO4) interface. In this study, LiInO2 and LiInO2–LiI were introduced as new cathode coating materials to suppress such undesirable reactions. The LiInO2–LiI composite coating layer reduced the undesirable interfacial reactions and prevented the diffusion of S and P ions from the sulfide electrolyte to the oxide cathode. Moreover, the electrochemical properties of all-solid-state cells were improved by the cathode coating. The LiInO2–LiI-coated electrode presented better rate capability and lower impedance than the pristine and LiInO2-coated electrodes. Hence, the LiInO2–LiI composite coating was successful at improving the cathode stability while providing superior electrochemical properties.
An ultra wideband-high spatial resolution-compact electric field sensor based on Lab-on-Fiber technology
Authors: Calero V. , Suarez M. -A. , Salut R. , Baida F. , Caspar A. , Behague F. , Courjal N. , Galtier L , Gillette L. , Duvillaret L. , Gaborit G. , Bernal M. -P.
Published: May 2019

Non-intrusive, wide bandwidth and spatial resolution are terms often heard in electric field sensing. Despite of the fact that conventional electromagnetic field probes (EMF) can exhibit notable functional performances, they fail in terms of perturbation of the E-field due to their loaded metallic structure. In addition, even though electro-optical technology offers an alternative, it requires large interaction lenghts which severely limit the sensing performances in terms of bandwidth and spatial resolution. Here, we focus on miniaturizing the interaction volume, photon lifetime and device footprint by taking advantage of the combination of lithium niobate (LN), Lab-on-Fiber technologies and photonic crystals (PhC). We demonstrate the operation of an all-dielectric E-field sensor whose ultra-compact footprint is inscribed in a 125 μm-diameter circle with an interaction area smaller than 19 μm × 19 μm and light propagation length of 700 nm. This submicrometer length provides outstanding bandwidth flatness, in addition to be promising for frequency detection beyond the THz. Moreover, the minituarization also provides unique features such as spatial resolution under 10 μm and minimal perturbation to the E-field, accompanied by great linearity with respect to the E-field strength. All these specifications, summarized to the high versatibility of Lab-on-Fiber technology, lead to a revolutionary and novel fibered E-field sensor which can be adapted to a broad range of applications in the fields of telecommunications, health and military.