bluuebunny/crossref_metadata_2025 huggingface dataset:
Which Extratropical Cyclones Contribute Most to the Transport of Moisture in the Southern Hemisphere?
Authors: Sinclair V. A. , Dacre H. F.
Published: February 2019

Predicted changes in Southern Hemisphere (SH) precipitation and Antarctic ice mass correspond to variations in the meridional moisture flux (MMF). Thirty‐five years of ERA‐Interim reanalysis data are combined with an extratropical cyclone (ETC) identification and tracking algorithm to investigate factors controlling SH MMF variability in the midlatitudes and near Antarctica. ETC characteristics which exert the strongest control on ETC MMF are determined thus identifying which ETCs contribute most to SH moisture transport. ETC poleward propagation speed exerts the strongest control on the ETC MMF across the Antarctic coastline. In SH winter, ETCs with the largest poleward propagation speeds transport 2.5 times more moisture than an average ETC. In the midlatitudes, ETC genesis latitude and poleward propagation speed have a similar influence on ETC MMF. Surprisingly, ETC maximum vorticity has little control on ETC MMF. Cyclone compositing is used to determine the reasons for these statistical relationships. ETCs generally exhibit a dipole of poleward and equatorward MMF downstream and upstream of the cyclone center, respectively. However, ETCs with the largest poleward propagation speeds resemble open frontal waves with strong poleward moisture transport downstream of the cyclone center only and thus result in the largest MMF. These results suggest that inhomogeneous trends and predicted changes in precipitation over Antarctica may be due to changes in cyclone track orientation, associated with changes to the large‐scale background flow, in addition to changes in cyclone number or intensity.
Global Occurrence and Chemical Impact of Stratospheric Blue Jets Modeled With WACCM4
Authors: Pérez‐Invernón F. J. , Gordillo‐Vázquez F. J. , Smith A. K. , Arnone E. , Winkler H.
Published: February 2019

In this work we present the first parameterizations of the global occurrence rate and chemical influence of Blue Jets, a type of transient luminous event taking place in the stratospheric region above thunderclouds. These parameterizations are directly coupled with five different lightning parameterizations implemented in the Whole Atmosphere Community Climate Model (WACCM4). We have obtained a maximum Blue Jet global occurrence rate of about 0.9 BJ per minute. The geographical occurrence of Blue Jets is closely related to the chosen lightning parameterization. Some previously developed local chemical models of Blue Jets predicted an important influence onto the stratospheric concentration of N2O, NOx, and O3. We have used these results together with our global implementations of Blue Jets in WACCM4 to estimate their global chemical influence in the atmosphere. According to our results, Blue Jets can inject about 3.8 Tg N2O‐N/year and 0.07 Tg NO‐N/year near the stratosphere, where N2O‐N and NO‐N stand for the mass of nitrogen atoms in N2O and NO molecules, respectively. These production rates of N2O and NOx could have a direct impact on, for example, the acidity of rainwater or the greenhouse effect. We have found that Blue Jets could also slightly contribute to the depletion of stratospheric ozone. In particular, we have estimated that the maximum difference in the concentration of O3 at 30 km of altitude between simulations with and without Blue Jets can be about −5% in equatorial and polar regions.
Differences in Eddy‐Correlation and Energy‐Balance Surface Turbulent Heat Flux Measurements and Their Impacts on the Large‐Scale Forcing Fields at the ARM SGP Site
Authors: Tang Shuaiqi , Xie Shaocheng , Zhang Minghua , Tang Qi , Zhang Yunyan , Klein Stephen A. , Cook David R. , Sullivan Ryan C.
Published: February 2019

Differences in the surface turbulent heat fluxes measured by the eddy correlation flux measurement system (ECOR) and the energy balance Bowen ratio system (EBBR) are examined using 12 years of continuous measurements collected at multiple stations in the Atmospheric Radiation Measurement (ARM) program Southern Great Plains (SGP) surface observational network. The flux measurements are found strongly impacted by their upwind surface types, which vary with wind direction. For collocated ECOR and EBBR at the central facility, the fluxes measured by ECOR and EBBR agree much better when their upwind fetches are over the same surface type. Among all stations at SGP, ECOR measures more over winter wheat fields while EBBR measures mostly over grassland. The different seasonality of growth cycles between winter wheat and grass causes systematic differences in measured fluxes between ECOR and EBBR. These differences impact the derived large‐scale forcing as illustrated in a constrained variational analysis, in which the state variables have to be adjusted according to different fluxes to keep the column‐integrated energy and moisture budgets in balance. This impact prevails in summertime on nonprecipitating days. A single‐column model test shows that model‐simulated boundary layer development is impacted by using the large‐scale forcing data of different surface turbulent fluxes. It is recommended to include both ECOR and EBBR measurements to better represent the domain‐mean turbulent fluxes and atmospheric budgets of energy and water vapor at the SGP.
Dynamo Action in the Steeply Decaying Conductivity Region of Jupiter‐Like Dynamo Models
Authors: Wicht J. , Gastine T. , Duarte L. D. V.
Published: February 2019

The Juno mission is delivering spectacular data of Jupiter's magnetic field, while the gravity measurements finally allow constraining the depth of the winds observed at cloud level. However, to which degree the zonal winds contribute to the planet's dynamo action remains an open question. Here we explore numerical dynamo simulations that include a Jupiter‐like electrical conductivity profile and successfully model the planet's large‐scale field. We concentrate on analyzing the dynamo action in the Steeply Decaying Conductivity Region (SDCR) where the high conductivity in the metallic Hydrogen region drops to the much lower values caused by ionization effects in the very outer envelope of the planet. Our simulations show that the dynamo action in the SDCR is strongly ruled by diffusive effects and is therefore quasi‐stationary. The locally induced magnetic field is dominated by the horizontal toroidal field, while the locally induced currents are dominated by the latitudinal component. The simple dynamics can be exploited to yield estimates of surprisingly high quality for both field and currents. These could potentially be exploited to predict the dynamo action of the zonal winds in Jupiter's SDCR but also in other planets.
Groundwater Storage in High Alpine Catchments and Its Contribution to Streamflow
Authors: Cochand M. , Christe P. , Ornstein P. , Hunkeler D.
Published: February 2019

There is limited knowledge about groundwater storage in alpine catchments, although it might strongly influence how these catchments react to earlier snowmelt due to climate change. The objective of the study was to develop and test a method to quantify seasonal groundwater storage in alpine catchments and evaluate how groundwater storage is related to hydrogeological properties. As representative water table observations are challenging to acquire in such environments, we used a water balance approach targeting the main snowmelt period when most groundwater recharge is expected to occur. Based on a detailed quantification of the snow water equivalent at the onset of snowmelt combined with discharge measurements, it is possible to quantify groundwater storage with a low uncertainty even if other terms of the water balance are less well constrained. The application of the method to an 11‐km2 research catchment revealed a large seasonal increase of groundwater storage by 300 mm or 45% of the premelt snow water equivalent. An independent quantification of groundwater storage depletion during the 7‐month‐long recession period provided a similar value of 330 mm, demonstrating that the stored groundwater is available to sustain streamflow. At the end of the recession, catchment outflow still amounted to 0.9 mm/day with a composite bedrock aquifer providing a disproportionally high share as demonstrated by hydrochemical data. The study demonstrates that high alpine aquifers can seasonally redistribute water and stabilize catchment outflow in an otherwise very dynamic environment and thus might strongly influence the response of such catchments to climate change.
Spatiotemporal Analysis of Soil Moisture and Optimal Sampling Design for Regional‐Scale Soil Moisture Estimation in a Tropical Watershed of India
Authors: Singh Gurjeet , Panda Rabindra Kumar , Mohanty Binayak P.
Published: February 2019

Regional‐scale soil moisture estimates are essential for several hydrological applications and for validating remote sensing‐based soil moisture products. Characterization of the regional‐scale soil moisture variability requires a robust in situ monitoring strategy at point scale to balance between representativeness and minimization of monitoring cost. In this study an optimal sampling design was determined to capture the spatiotemporal variability of soil moisture at watershed scale. The study was conducted for the typical Indian conditions of extreme seasonal variability that leads to very wet (during monsoon) to dry (during hot summer) in the eastern India. Soil moisture monitoring was done at 83 locations in an agricultural watershed of 500 km2 for 56 days of field campaigns across a year. Based on the analyses of 41,832 measurements collected during field campaigns, it was found that maximum numbers of required locations necessary to estimate watershed‐mean soil moisture within ±2% accuracy are 30. Moreover, five randomly selected locations were found to be sufficient for capturing the temporal variability of watershed‐mean soil moisture with an accuracy of ±3%. In addition, five most representative locations identified through time stability analysis can provide robust estimate of watershed‐mean soil moisture with accuracy of ±2%. Further, soil properties and topography are identified as significant physical parameters that jointly control the spatiotemporal persistence and variability of soil moisture in the Indian watershed. These findings will be quite useful to provide guidelines for optimizing short‐term soil moisture campaigns by sampling at few selected points representative of the watershed‐mean behavior.
Isolation of Individual Saturated Fatty Acid Methyl Esters Derived From Groundwater Phospholipids by Preparative High‐Pressure Liquid Chromatography for Compound‐Specific Radiocarbon Analyses
Authors: Schwab Valérie F. , Nowak Martin E. , Trumbore Susan E. , Xu Xiaomei , Gleixner Gerd , Muhr Jan , Küsel Kirsten , Totsche Kai U.
Published: February 2019

Determining the biogeochemical pathways utilized by microbes living in groundwater is essential for understanding the subsurface C cycle and the fate of organic compounds, including pollutants. The radiocarbon signature (Δ14C) of fatty acid methyl esters derived from microbial phospholipids (PLFA) provides useful information for differentiating microbial C sources and infering microbial metabolism. However, in subsurface environments, those analyses remain challenging. Here we present a method combining large volume groundwater filtration (up to 10,000 L) and PLFA purification for subsequent compound‐specific radiocarbon analyses. The analytical method involves conventional chemical extraction of PLFA followed by purification of individual compounds by semipreparative high‐performance liquid chromatography. Different saturated PLFA in amounts of up to 10 μg each can be simultaneously separated on a C18 high‐load column using a mixture of MeOH/water and acetonitrile as the mobile phase. Our procedure introduced dead‐Cext contaminations of 0.57 ± 0.29 and 0.35 ± 0.18 μg for the high‐performance liquid chromatography and combustion/graphitization steps of the sample preparation, respectively. However, tests on different high‐performance liquid chromatography C18 columns revealed a large difference in dead Cext associated with column bleed. Modern Cext in the amount of 0.40 ± 0.20 μg was introduced by the combustion/graphitization step of the sample preparation, but other steps did not add modern Cext. The entire method recovered ∼50% of the purified compounds on average, but this did not affect their 14C content. This method will allow routine analysis of the Δ14C of PLFA isolated from groundwaters or other sample types, revealing the relationships between microbial and soil‐derived C, sedimentary or dissolved C sources.
Varying Impact of Earthquake- and Monsoon-Induced Landslides
Authors: Kornei Katherine
Published: February 2019

Using nearly 50 years of satellite data and records stretching back millennia, scientists determine the relative frequency—and the erosional power—of monsoon- and earthquake-induced landslides in Nepal.
The Influence of Solar Wind Pressure on Martian Crustal Magnetic Field Topology
Authors: Weber Tristan , Brain David , Mitchell David , Xu Shaosui , Espley Jared , Halekas Jasper , Lillis Robert , Jakosky Bruce
Published: February 2019

We present a study of changes in Martian magnetic topology induced by upstream solar wind ram pressure variations. Using electron energy spectra and pitch angle distributions measured by the Mars Atmosphere and Volatile EvolutioN (MAVEN) spacecraft, we classify the topology of magnetic field lines in the Martian space environment across a range of solar wind conditions. We find that during periods of high solar wind dynamic pressure, draped fields are pushed to lower altitudes on the dayside of the planet, compressing closed fields. At the same time, open topology becomes more prevalent on the nightside due to the broadening of crustal cusp regions. The result is a decrease in closed topology at all locations around Mars, suggesting that the Martian ionosphere becomes significantly more exposed to solar wind energy input during high solar wind pressure. This could likely contribute to elevated levels of ion escape during these periods.
Magnetic Effects of Plasma Pressure Gradients in the Upper F Region
Authors: Laundal K. M. , Hatch S. M. , Moretto T.
Published: February 2019

The Swarm satellites fly at altitudes that at polar latitudes are generally assumed to only contain currents that are aligned with the local magnetic field. Therefore, disturbances along the main field direction are mainly signatures of auroral electrojet currents, with a relatively smooth structure due to the distance from the currents. Here we show that superimposed on this smooth signal is an irregular pattern of small perturbations, which are anticorrelated with the plasma density measured by the Langmuir probe. We show that the perturbations can be remarkably well reproduced by assuming they represent a j × B force, which balances the plasma pressure gradient implied by the density variations. The associated diamagnetic current, previously reported to be most important near the equator, appears to be a ubiquitous phenomenon also at polar latitudes. A spectral analysis indicates that this effect dominates magnetic field intensity variations at small‐scale sizes of a few tens of kilometers.
Intraslab Deformation in the 30 November 2018 Anchorage, Alaska, MW 7.1 Earthquake
Authors: Liu Chengli , Lay Thorne , Xie Zujun , Xiong Xiong
Published: February 2019

Anchorage, Alaska, was strongly shaken on 30 November 2018 by an MW 7.1 earthquake that ruptured within the underthrust Pacific plate at depths of from 45 to 65 km. Ground failures occurred in saturated lowlands filled with sediments, producing notable road damage, but there was limited structural damage in Anchorage, only ~12 km south of the epicenter. The earthquake has a normal faulting geometry with a shallowly dipping east‐west tension axis indicating intraslab deformation, likely between the underthrust Yakutat terrane and adjacent Pacific seafloor. Separate and joint inversions of teleseismic P and SH waves, regional strong ground motions, and GPS static displacements provide a weak preference for a westward steeply dipping rupture plane with up to 2 m of slip distributed over a single slip patch with dimensions of 20 × 20 km. The ~12 s long rupture expanded northward. Aftershocks occur at shallower depths than the mainshock slip zone.
Acetone Atmospheric Distribution Retrieved From Space
Authors: Franco B. , Clarisse L. , Stavrakou T. , Müller J.‐F. , Pozzer A. , Hadji‐Lazaro J. , Hurtmans D. , Clerbaux C. , Coheur P.‐F.
Published: February 2019

As one of the most abundant oxygenated volatile organic compounds in the atmosphere, acetone (CH3C[O]CH3) influences atmospheric oxidants levels and ozone formation. Here we report the first unambiguous identification of acetone from the nadir‐viewing satellite sounder Infrared Atmospheric Sounding Interferometer (IASI). Via a neural network‐based retrieval approach that was previously applied to the retrieval of other weak absorbers, we obtain daily global acetone retrievals. A first intercomparison with independent measurements is conducted. As the retrieval method is computationally fast, it allowed the full reprocessing of the 2007–2018 IASI time series. Analysis of the retrieved global product and its seasonality suggests that emissions of acetone and precursors from the terrestrial biosphere at Northern Hemisphere middle and high latitudes are the main contributors to the atmospheric acetone abundance, more than year‐round oxidation of anthropogenic isoalkanes. Remarkably, biomass burning does not appear to be a strong global source of acetone.
Radar Studies of Height‐Dependent Equatorial F region Vertical and Zonal Plasma Drifts
Authors: Shidler S. A. , Rodrigues F. S. , Fejer B. G. , Milla M. A.
Published: February 2019

We present the results of an analysis of long‐term measurements of ionospheric F region E × B plasma drifts in the American/Peruvian sector. The analysis used observations made between 1986 and 2017 by the incoherent scatter radar of the Jicamarca Radio Observatory. Unlike previous studies, we analyzed both vertical and zonal components of the plasma drifts to derive the geomagnetically quiet time climatological variation of the drifts as a function of height and local time. We determine the average behavior of the height profiles of the drifts for different seasons and distinct solar flux conditions. Our results show good agreement with previous height‐averaged climatological results of vertical and zonal plasma drifts, despite that they are obtained from different sets of measurements. More importantly, our results quantify average height variations in the drifts. The results show, for example, the solar flux control over the height variation of the vertical drifts. The results also show the weak dependence of the daytime zonal drift profiles on solar and seasonal variations. We quantify the effects of seasonal and solar flux variations on the morphology of the vertical shear in the zonal plasma drifts associated with the evening plasma vortex. Assuming interchangeability between local time and longitude, we tested the curl‐free condition for the F region electric fields with very good results for all seasons and solar flux conditions. We envision the use of our results to aid numerical modeling of ionospheric electrodynamics and structuring and to assist with the interpretation of satellite observations of low‐latitude plasma drifts.
Glutamine synthetase is necessary for sarcoma adaptation to glutamine deprivation and tumor growth
Authors: Issaq Sameer H. , Mendoza Arnulfo , Fox Stephen D. , Helman Lee J.
Published: February 2019

Despite a growing body of knowledge about the genomic landscape and molecular pathogenesis of sarcomas, translation of basic discoveries into targeted therapies and significant clinical gains has remained elusive. Renewed interest in altered metabolic properties of cancer cells has led to an exploration of targeting metabolic dependencies as a novel therapeutic strategy. In this study, we have characterized the dependency of human pediatric sarcoma cells on key metabolic substrates and identified a mechanism of adaptation to metabolic stress by examining proliferation and bioenergetic properties of rhabdomyosarcoma and Ewing sarcoma cells under varying concentrations of glucose and glutamine. While all cell lines tested were completely growth-inhibited by lack of glucose, cells adapted to glutamine deprivation, and restored proliferation following an initial period of reduced growth. We show that expression of glutamine synthetase (GS), the enzyme responsible for de novo glutamine synthesis, increased during glutamine deprivation, and that pharmacological or shRNA-mediated GS inhibition abolished proliferation of glutamine-deprived cells, while having no effect on cells grown under normal culture conditions. Moreover, the GS substrates and glutamine precursors glutamate and ammonia restored proliferation of glutamine-deprived cells in a GS-dependent manner, further emphasizing the necessity of GS for adaptation to glutamine stress. Furthermore, pharmacological and shRNA-mediated GS inhibition significantly reduced orthotopic xenograft tumor growth. We also show that glutamine supports sarcoma nucleotide biosynthesis and optimal mitochondrial bioenergetics. Our findings demonstrate that GS mediates proliferation of glutamine-deprived pediatric sarcomas, and suggest that targeting metabolic dependencies of sarcomas should be further investigated as a potential therapeutic strategy.
Hyperacidification of Citrus fruits by a vacuolar proton-pumping P-ATPase complex
Authors: Strazzer Pamela , Spelt Cornelis E. , Li Shuangjiang , Bliek Mattijs , Federici Claire T. , Roose Mikeal L. , Koes Ronald , Quattrocchio Francesca M.
Published: February 2019

The sour taste ofCitrusfruits is due to the extreme acidification of vacuoles in juice vesicle cells via a mechanism that remained elusive. Genetic analysis in petunia identified two vacuolar P-ATPases, PH1 and PH5, which determine flower color by hyperacidifying petal cell vacuoles. Here we show thatCitrushomologs, CitPH1 and CitPH5, are expressed in sour lemon, orange, pummelo and rangpur lime fruits, while their expression is strongly reduced in sweet-tasting “acidless” varieties. Down-regulation ofCitPH1andCitPH5is associated with mutations that disrupt expression of MYB, HLH and/or WRKY transcription factors homologous to those activatingPH1andPH5in petunia. These findings address a long-standing enigma in cell biology and provide targets to engineer or select for taste inCitrusand other fruits.
G-quadruplex DNA drives genomic instability and represents a targetable molecular abnormality in ATRX-deficient malignant glioma
Authors: Wang Yuxiang , Yang Jie , Wild Aaron T. , Wu Wei H. , Shah Rachna , Danussi Carla , Riggins Gregory J. , Kannan Kasthuri , Sulman Erik P. , Chan Timothy A. , Huse Jason T.
Published: February 2019

Mutational inactivation of ATRX (α-thalassemia mental retardation X-linked) represents a defining molecular alteration in large subsets of malignant glioma. Yet the pathogenic consequences of ATRX deficiency remain unclear, as do tractable mechanisms for its therapeutic targeting. Here we report that ATRX loss in isogenic glioma model systems induces replication stress and DNA damage by way of G-quadruplex (G4) DNA secondary structure. Moreover, these effects are associated with the acquisition of disease-relevant copy number alterations over time. We then demonstrate, both in vitro and in vivo, that ATRX deficiency selectively enhances DNA damage and cell death following chemical G4 stabilization. Finally, we show that G4 stabilization synergizes with other DNA-damaging therapies, including ionizing radiation, in the ATRX-deficient context. Our findings reveal novel pathogenic mechanisms driven by ATRX deficiency in glioma, while also pointing to tangible strategies for drug development.
Bandgap prediction by deep learning in configurationally hybridized graphene and boron nitride
Authors: Dong Yuan , Wu Chuhan , Zhang Chi , Liu Yingda , Cheng Jianlin , Lin Jian
Published: February 2019

It is well-known that the atomic-scale and nano-scale configuration of dopants can play a crucial role in determining the electronic properties of materials. However, predicting such effects is challenging due to the large range of atomic configurations that are possible. Here, we present a case study of how deep learning algorithms can enable bandgap prediction in hybridized boron–nitrogen graphene with arbitrary supercell configurations. A material descriptor that enables correlation of structure and bandgap was developed for convolutional neural networks. Bandgaps calculated by ab initio calculations, and corresponding structures, were used as training datasets. The trained networks were then used to predict bandgaps of systems with various configurations. For 4 × 4 and 5 × 5 supercells they accurately predict bandgaps, with a R2 of >90% and root-mean-square error of ~0.1 eV. The transfer learning was performed by leveraging data generated from small supercells to improve the prediction accuracy for 6 × 6 supercells. This work will pave a route to future investigation of configurationally hybridized graphene and other 2D materials. Moreover, given the ubiquitous existence of configurations in materials, this work may stimulate interest in applying deep learning algorithms for the configurational design of materials across different length scales.
Publisher Correction: Model-Based Therapy Planning Allows Prediction of Haemodynamic Outcome after Aortic Valve Replacement
Authors: Kelm M. , Goubergrits L. , Bruening J. , Yevtushenko P. , Fernandes J. F. , Sündermann S. H. , Berger F. , Falk V. , Kuehne T. , Nordmeyer S. ,   CARDIOPROOF group, Morley-Fletcher E. , De Maldè M. , Muthurangu V. , Khushnood A. , Chinali M. , Pongiglione G. , Hennemuth A. , Mirzae H. , Neugebauer M. , Ecabert O. , Neumann D. , Groenenboom P. , Plank G. , Manset D. , McGuire A. , Naci H. , Salcher M.
Published: February 2019

A correction to this article has been published and is linked from the HTML and PDF versions of this paper. The error has been fixed in the paper.
Publisher Correction: A biomimicry design for nanoscale radiative cooling applications inspired by Morpho didius butterfly
Authors: Didari Azadeh , Mengüç M. Pinar
Published: February 2019

A correction to this article has been published and is linked from the HTML and PDF versions of this paper. The error has been fixed in the paper.
The importance of plasmonic heating for the plasmon-driven photodimerization of 4-nitrothiophenol
Authors: Sarhan Radwan M. , Koopman Wouter , Schuetz Roman , Schmid Thomas , Liebig Ferenc , Koetz Joachim , Bargheer Matias
Published: February 2019

Metal nanoparticles form potent nanoreactors, driven by the optical generation of energetic electrons and nanoscale heat. The relative influence of these two factors on nanoscale chemistry is strongly debated. This article discusses the temperature dependence of the dimerization of 4-nitrothiophenol (4-NTP) into 4,4′-dimercaptoazobenzene (DMAB) adsorbed on gold nanoflowers by Surface-Enhanced Raman Scattering (SERS). Raman thermometry shows a significant optical heating of the particles. The ratio of the Stokes and the anti-Stokes Raman signal moreover demonstrates that the molecular temperature during the reaction rises beyond the average crystal lattice temperature of the plasmonic particles. The product bands have an even higher temperature than reactant bands, which suggests that the reaction proceeds preferentially at thermal hot spots. In addition, kinetic measurements of the reaction during external heating of the reaction environment yield a considerable rise of the reaction rate with temperature. Despite this significant heating effects, a comparison of SERS spectra recorded after heating the sample by an external heater to spectra recorded after prolonged illumination shows that the reaction is strictly photo-driven. While in both cases the temperature increase is comparable, the dimerization occurs only in the presence of light. Intensity dependent measurements at fixed temperatures confirm this finding.
Proteomic analysis of cholera toxin adjuvant-stimulated human monocytes identifies Thrombospondin-1 and Integrin-β1 as strongly upregulated molecules involved in adjuvant activity
Authors: Terrinoni Manuela , Holmgren Jan , Lebens Michael , Larena Maximilian
Published: February 2019

Cholera Toxin (CT) as well as its related non-toxic mmCT and dmLT mutant proteins have been shown to be potent adjuvants for mucosally administered vaccines. Their adjuvant activity involves activation of cAMP/protein kinase A (PKA) signaling and inflammasome/IL-1β pathways in antigen presenting cells (APC). To get a further understanding of the signal transduction and downstream pathways activated in APCs by this group of adjuvants we have, employing quantitative proteomic analytic tools, investigated human monocytes at various time points after treatment with CT. We report the activation of three main biological pathways among upregulated proteins, peaking at 16 hours of CT treatment: cellular organization, metabolism, and immune response. Specifically, in the further analyzed immune response pathway we note a strong upregulation of thrombospondin 1 (THBS1) and integrin β1 (ITGB1) in response to CT as well as to mmCT and dmLT, mediated via cAMP/PKA and NFKB signaling. Importantly, inhibitionin vitroof THSB1 and ITGB1 in monocytes or primary dendritic cells using siRNA abrogated the ability of the treated APCs to promote an adjuvant-stimulated Th17 cell response when co-cultured with peripheral blood lymphocytes indicating the involvement of these molecules in the adjuvant action on APCs by CT, mmCT and dmLT.
High Throughput Laser Process of Transparent Conducting Surfaces for Terahertz Bandpass Ultrathin Metamaterials
Authors: Wang Qinghua , Raglione Michaella , Li Baojia , Jin Xin , Toor Fatima , Arnold Mark , Ding Hongtao
Published: February 2019

Terahertz (THz) imaging has attracted much attention within the past decade as an emerging nondestructive evaluation technique. In this paper, we present a novel Laser-based Metamaterial Fabrication (LMF) process for high-throughput fabrication of transparent conducting surfaces on dielectric substrates such as glass, quartz and polymers to achieve tunable THz bandpass characteristics. The LMF process comprises two steps: (1) applying ultrathin-film metal deposition, with a typical thickness of 10 nm, on the dielectric substrate; (2) creating a ~100-micron feature pattern on the metal film using nanosecond pulsed laser ablation. Our results demonstrate the use of laser-textured ultra-thin film with newly integrated functional capabilities: (a) highly conductive with ~20 Ω/sq sheet resistance, (b) optically transparent with ~70% transmittance within visible spectrum, and (c) tunable bandpass filtering effect in the THz frequency range. A numerical analysis is performed to help determine the fundamental mechanism of THz bandpass filtering for the LMF-built samples. The scientific findings from this work render an economical and scalable manufacturing technique capable of treating large surface area for multi-functional metamaterials.
Natural biocide disrupts nestmate recognition in honeybees
Authors: Cappa Federico , Petrocelli Iacopo , Dani Francesca Romana , Dapporto Leonardo , Giovannini Michele , Silva-Castellari Jeferson , Turillazzi Stefano , Cervo Rita
Published: February 2019

Honeybee colonies are under the threat of many stressors, biotic and abiotic factors that strongly affect their survival. Recently, great attention has been directed at chemical pesticides, including their effects at sub-lethal doses on bee behaviour and colony success; whereas the potential side effects of natural biocides largely used in agriculture, such as entomopathogenic fungi, have received only marginal attention. Here, we report the impact of the fungus Beauveria bassiana on honeybee nestmate recognition ability, a crucial feature at the basis of colony integrity. We performed both behavioural assays by recording bee guards’ response towards foragers (nestmate or non-nestmate) either exposed to B. bassiana or unexposed presented at the hive entrance, and GC-MS analyses of the cuticular hydrocarbons (CHCs) of fungus-exposed versus unexposed bees. Our results demonstrated that exposed bees have altered cuticular hydrocarbons and are more easily accepted into foreign colonies than controls. Since CHCs are the main recognition cues in social insects, changes in their composition appear to affect nestmate recognition ability at the colony level. The acceptance of chemically unrecognizable fungus-exposed foragers could therefore favour forager drift and disease spread across colonies.
Initial findings of striatum tripartite model in OCD brain samples based on transcriptome analysis
Authors: Lisboa Bianca C. G. , Oliveira Katia C. , Tahira Ana Carolina , Barbosa André Rocha , Feltrin Arthur Sant’Anna , Gouveia Gisele , Lima Luzia , Feio dos Santos Ana Cecília , Martins David Correa , Puga Renato David , Moretto Ariane Cristine , De Bragança Pereira Carlos Alberto , Lafer Beny , Leite Renata Elaine Paraizo , Ferretti-Rebustini Renata Eloah De Lucena , Farfel Jose Marcelo , Grinberg Lea Tenenholz , Jacob-Filho Wilson , Miguel Euripedes Constantino , Hoexter Marcelo Queiroz , Brentani Helena
Published: February 2019

Obsessive-compulsive disorder (OCD) is a psychiatric disorder characterized by obsessions and/or compulsions. Different striatal subregions belonging to the cortico-striato-thalamic circuitry (CSTC) play an important role in the pathophysiology of OCD. The transcriptomes of 3 separate striatal areas (putamen (PT), caudate nucleus (CN) and accumbens nucleus (NAC)) from postmortem brain tissue were compared between 6 OCD and 8 control cases. In addition to network connectivity deregulation, different biological processes are specific to each striatum region according to the tripartite model of the striatum and contribute in various ways to OCD pathophysiology. Specifically, regulation of neurotransmitter levels and presynaptic processes involved in chemical synaptic transmission were shared between NAC and PT. The Gene Ontology terms cellular response to chemical stimulus, response to external stimulus, response to organic substance, regulation of synaptic plasticity, and modulation of synaptic transmission were shared between CN and PT. Most genes harboring common and/or rare variants previously associated with OCD that were differentially expressed or part of a least preserved coexpression module in our study also suggest striatum subregion specificity. At the transcriptional level, our study supports differences in the 3 circuit CSTC model associated with OCD.
Identification of Cytotoxic Flavor Chemicals in Top-Selling Electronic Cigarette Refill Fluids
Authors: Hua My , Omaiye Esther E. , Luo Wentai , McWhirter Kevin J. , Pankow James F. , Talbot Prue
Published: February 2019

We identified the most popular electronic cigarette (EC) refill fluids using an Internet survey and local and online sales information, quantified their flavor chemicals, and evaluated cytotoxicities of the fluids and flavor chemicals. “Berries/Fruits/Citrus” was the most popular EC refill fluid flavor category. Twenty popular EC refill fluids were purchased from local shops, and the ingredient flavor chemicals were identified and quantified by gas chromatography-mass spectrometry. Total flavor chemical concentrations ranged from 0.6 to 27.9 mg/ml, and in 95% of the fluids, total flavor concentration was greater than nicotine concentration. The 20 most popular refill fluids contained 99 quantifiable flavor chemicals; each refill fluid contained 22 to 47 flavor chemicals, most being esters. Some chemicals were found frequently, and several were present in most products. At a 1% concentration, 80% of the refill fluids were cytotoxic in the MTT assay. Six pure standards of the flavor chemicals found at the highest concentrations in the two most cytotoxic refill fluids were effective in the MTT assay, and ethyl maltol, which was in over 50% of the products, was the most cytotoxic. These data show that the cytotoxicity of some popular refill fluids can be attributed to their high concentrations of flavor chemicals.
Gate-Tunable Plasmon-Induced Transparency Modulator Based on Stub-Resonator Waveguide with Epsilon-Near-Zero Materials
Authors: Tao Long , Anopchenko Aleksei , Gurung Sudip , Zhang Jinqiannan , Lee Ho Wai Howard
Published: February 2019

We demonstrate an electrically tunable ultracompact plasmonic modulator with large modulation strength (>10 dB) and a small footprint (~1 μm in length) via plasmon-induced transparency (PIT) configuration. The modulator based on a metal-oxide-semiconductor (MOS) slot waveguide structure consists of two stubs embedded on the same side of a bus waveguide forming a coupled system. Heavily n-doped indium tin oxide (ITO) is used as the semiconductor in the MOS waveguide. A large modulation strength is realized due to the formation of the epsilon-near-zero (ENZ) layer at the ITO-oxide interface at the wavelength of the modulated signal. Numerical simulation results reveal that such a significant modulation can be achieved with a small applied voltage of ~3V. This result shows promise in developing nanoscale modulators for next generation compact photonic/plasmonic integrated circuits.
Genome-wide association study suggests impact of chromosome 10 rs139401390 on kidney function in patients with coronary artery disease
Authors: Schmitz Boris , Kleber Marcus E. , Lenders Malte , Delgado Graciela E. , Engelbertz Christiane , Huang Jie , Pavenstädt Hermann , Breithardt Günter , Brand Stefan-Martin , März Winfried , Brand Eva
Published: February 2019

Chronic kidney disease (CKD) is an independent risk factor for onset and progression of coronary artery disease (CAD). Discovery of predisposing loci for kidney function in CAD patients was performed using a genome-wide association approach. Inclusion criteria were CAD with ≥50% stenosis (≥1 coronary artery) and a creatinine-based estimated glomerular filtration rate (eGFR) of 30–75 ml/min/1.73 m2. An association of rs139401390 located to a region 58.8 kb upstream of renalase (RNLS) with eGFR was detected in the Ludwigshafen Risk and Cardiovascular Health (LURIC) study (n = 499, p = 7.88 × 10−9, mean eGFR 60.7 ml/min/1.73 m2). Direct genotyping of rs139401390A > G suggested increased eGFR by 12.0 ml/min/1.73 m2 per A allele (p = 0.000004). Genome-wide replication of rs139401390A > G in the Coronary Artery Disease and Renal Failure (CAD-REF) registry with a mean eGFR of 47.8 ml/min/1.73 m2 (n = 574, p = 0.033) was only nominally significant. Comparison of rs139401390 genotypes for risk of reduced kidney function in the overall LURIC study revealed higher adjusted odds ratios (OR) for eGFR <60 ml/min/1.73 m2 for CAD patients (n = 1992, OR = 2.36, p = 0.008, G/A + G/G vs A/A) compared to patients with/without CAD (n = 2908, OR = 1.97, p = 0.014, G/A + G/G vs A/A). No significant risk elevation was detected in patients without CAD (n = 948, p = 0.571). rs139401390 may affect kidney function in CAD patients with mild reduction in eGFR.
SerpinB2 is involved in cellular response upon UV irradiation
Authors: Majoros Hajnalka , Ujfaludi Zsuzsanna , Borsos Barbara Nikolett , Hudacsek Viktória Vivien , Nagy Zita , Coin Frederic , Buzas Krisztina , Kovács Ilona , Bíró Tamás , Boros Imre Miklós , Pankotai Tibor
Published: February 2019

Ultraviolet light induced pyrimidine dimer is a helix distortion DNA damage type, which recruits repair complexes. However, proteins of these complexes that take part in both DNA damage recognition and repair have been well-described, the regulation of the downstream steps of nucleotide excision repair (NER) have not been clearly clarified yet. In a high-throughput screen, we identified SerpinB2 (SPB2) as one of the most dramatically upregulated gene in keratinocytes following UV irradiation. We found that both the mRNA and the protein levels of SPB2 were increased upon UV irradiation in various cell lines. Additionally, UV damage induced translocation of SPB2 from the cytoplasm to the nucleus as well as the damage induced foci formation of it. Here we show that SPB2 co-localizes with XPB involved in the NER pathway at UV-induced repair foci. Finally, we demonstrated that UV irradiation promoted the association of SPB2 with ubiquitylated proteins. In basal cell carcinoma tumour cells, we identified changes in the subcellular localization of SPB2. Based on our results, we conclude that SPB2 protein has a novel role in UV-induced NER pathway, since it regulates the removal of the repair complex from the damaged site leading to cancerous malformation.
Cavitation dose painting for focused ultrasound-induced blood-brain barrier disruption
Authors: Yang Yaoheng , Zhang Xiaohui , Ye Dezhuang , Laforest Richard , Williamson Jeffrey , Liu Yongjian , Chen Hong
Published: February 2019

Focused ultrasound combined with microbubble for blood-brain barrier disruption (FUS-BBBD) is a promising technique for noninvasive and localized brain drug delivery. This study demonstrates that passive cavitation imaging (PCI) is capable of predicting the location and concentration of nanoclusters delivered by FUS-BBBD. During FUS-BBBD treatment of mice, the acoustic emissions from FUS-activated microbubbles were passively detected by an ultrasound imaging system and processed offline using a frequency-domain PCI algorithm. After the FUS treatment, radiolabeled gold nanoclusters, 64Cu-AuNCs, were intravenously injected into the mice and imaged by positron emission tomography/computed tomography (PET/CT). The centers of the stable cavitation dose (SCD) maps obtained by PCI and the corresponding centers of the 64Cu-AuNCs concentration maps obtained by PET coincided within 0.3 ± 0.4 mm and 1.6 ± 1.1 mm in the transverse and axial directions of the FUS beam, respectively. The SCD maps were found to be linearly correlated with the 64Cu-AuNCs concentration maps on a pixel-by-pixel level. These findings suggest that SCD maps can spatially “paint” the delivered nanocluster concentration, a technique that we named as cavitation dose painting. This PCI-based cavitation dose painting technique in combination with FUS-BBBD opens new horizons in spatially targeted and modulated brain drug delivery.
A role for Vibrio vulnificus PecS during hypoxia
Authors: Bhattacharyya Nabanita , Lemon Tiffany L. , Grove Anne
Published: February 2019

The genus Vibrio includes serious human pathogens, and mollusks are a significant reservoir for species such as V. vulnificus. Vibrio species encode PecS, a member of the multiple antibiotic resistance regulator (MarR) family of transcription factors; pecS is divergently oriented to pecM, which encodes an efflux pump. We report here that Vibrio species feature frequent duplications of pecS-pecM genes, suggesting evolutionary pressures to respond to distinct environmental situations. The single V. vulnificus PecS binds two sites within the pecS-pecM intergenic region with Kd = 0.3 ± 0.1 nM, a binding that is attenuated by the ligands xanthine and urate, except when promoter DNA is saturated with PecS. A unique target is found in the intergenic region between genes encoding the nitric oxide sensing transcription factor, NsrR, and nod; the nod-encoded nitric oxide dioxygenase is important for preventing nitric oxide stress. Reporter gene assays show that PecS-mediated repression of gene expression can be relieved in presence of ligand. Since xanthine and urate are produced as part of the oxidative burst during host defenses and under molluscan hypoxia, we propose that these intermediates in the host purine degradation pathway function to promote bacterial survival during hypoxia and oxidative stress.
Biomechanical properties of fishing lines of the glowworm Arachnocampa luminosa (Diptera; Keroplatidae)
Authors: von Byern Janek , Chandler Pete , Merritt David , Adlassnig Wolfram , Stringer Ian , Meyer-Rochow Victor Benno , Kovalev Alexander , Dorrer Victoria , Dimartino Simone , Marchetti-Deschmann Martina , Gorb Stanislav
Published: February 2019

Animals use adhesive secretions in highly diverse ways, such as for settlement, egg anchorage, mating, active or passive defence, etc. One of the most interesting functions is the use of bioadhesives to capture prey, as the bonding has to be performed within milliseconds and often under unfavourable conditions. While much is understood about the adhesive and biomechanical properties of the threads of other hunters such as spiders, barely anything is documented about those of the New Zealand glowwormArachnocampa luminosa. We analysed tensile properties of the fishing lines of the New Zealand glowwormArachnocampa luminosaunder natural and dry conditions and measured their adhesion energy to different surfaces. The capture system ofA.luminosais highly adapted to the prevailing conditions (13–15 °C, relative humidity of 98%) whereby the wet fishing lines only show a bonding ability at high relative humidity (>80%) with a mean adhesive energy from 20–45 N/m and a stronger adhesion to polar surfaces. Wet threads show a slightly higher breaking strain value than dried threads, whereas the tensile strength of wet threads was much lower. The analyses show that breaking stress and strain values inArachnocampa luminosawere very low in comparison to relatedArachnocampaspecies and spider silk threads but exhibit much higher adhesion energy values. While the mechanical differences between the threads of variousArachnocampaspecies might be consequence of the different sampling and handling of the threads prior to the tests, differences to spiders could be explained by habitat differences and differences in the material ultrastructure. Orb web spiders produce viscid silk consisting of β-pleated sheets, whereasArachnocampahas cross-β–sheet crystallites within its silk. As a functional explanation, the low tear strength forA.luminosacomprises a safety mechanism and ensures the entire nest is not pulled down by prey which is too heavy.
Phosphorylation Changes in Response to Kinase Inhibitor H89 in PKA-Null Cells
Authors: Limbutara Kavee , Kelleher Andrew , Yang Chin-Rang , Raghuram Viswanathan , Knepper Mark A.
Published: February 2019

Protein phosphorylation, mediated by protein kinases, plays a crucial role in cellular regulation. One of the most important protein kinases is protein kinase A (PKA). N-[2-p-bromocinnamylamino-ethyl]-5-isoquinolinesulphonamide (H89) is often used as a “PKA specific inhibitor” to study the involvement of PKA in signaling pathways. However, evidence from cell-free experiments has suggested that H89 can also inhibit other protein kinases. In this study, previously generated PKA-null and PKA-intact mouse cell lines derived from mpkCCD cells were treated with H89 over a range of concentrations commonly used in the literature, followed by mass spectrometry-based phosphoproteomics to globally assess changes in phosphorylation. From a total of 14,139 phosphorylation sites quantified, we found that 571 and 263 phosphorylation sites with significant changes in abundance in PKA-intact and PKA-null cells, respectively. Analyses of sequence logos generated from significantly decreased phosphorylation sites in PKA-intact and PKA-null cells both revealed a preference for basic amino acids at position −3 and −2. Thus, H89 appears to inhibit basophilic kinases even in the absence of PKA. Likely H89 targets include basophilic protein kinases such as AKT, RSK, AMPK and ROCK. We conclude that, in intact cells, H89 can affect activities of protein kinases other than PKA, and therefore responses to H89 should not be regarded as sufficient evidence for PKA involvement in a signaling process.