bluuebunny/crossref_metadata_2025 huggingface dataset:
Electrochemical Detection of 4‐Chlorophenol Using Glassy Carbon Electrodes Modified with Thulium Double‐Decker Phthalocyanine Salts
Authors: Sekhosana Kutloano Edward , Shumba Munyaradzi , Nyokong Tebello
Published: August 2019

This paper presents newly developed electrochemical sensors based on green and blue lanthanide double‐decker phthalocyanines (LnPc2), with the green LnPc2 derivative referred to as 2 a while the blue counterpart is designated 2 b. The modified glassy carbon electrode (GCE) based on the blue LnPc2 complex is referred to as 2 b‐GCE while that which is based on the green LnPc2 complex is named 2 a‐GCE. The oxidation of 4‐chlorophenol is extensively investigated and found to differ from one modified electrode to the next. Interestingly, the electrode modified with blue LnPc2 complex (2 b‐GCE) showed lower peak potential 0.88 V vs Ag|AgCl and higher catalytic current of 593 μA compared to that based on the green LnPc2 counterpart (2 b‐GCE) which exhibited ∼ 1.05 V vs Ag|AgCl and 65 μA, respectively. Remarkable differences in Tafel slopes were also found to be complimented by high rate constants in the order: 2 b‐GCE>2 a‐GCE. The lowest limit of detection (LOD) was found for 2 b‐GCE at 4.16 ×10−8 M in comparison to that for 2 a‐GCE at 6.14 ×10−6 M. When investigating the electrochemical behavior, it was found that the first one‐electron oxidation minus the first one‐electron reduction differences were very low at 0.36 V and 0.55 V vs Ag|AgCl for 2 b and 2 a, respectively. Such values are comparable to the literature values for lutetium bisphthalocyanines.
Tiny Ruthenium‐Cobalt‐Cobalt Hydroxide Nanoparticles Supported on Graphene for Efficiently Catalyzing Naphthalene Complete Hydrogenation
Authors: Zhu Lihua , Cui Jingjing , Ruan Luna , Zhang Huan , Yu Changlin , Chen Bing Hui , Xiao Qiang
Published: August 2019

The nanocatalyst of graphene‐supported ruthenium/cobalt/cobalt hydroxide nanoparticles (denoted as Ru/Co/Co(OH)2/G) was obtained at ambient temperature by using chemical reduction with hydrazine hydrate as reducing agent and galvanic replacement reaction methods. The nanostructure of Ru nanoclusters‐on‐cobalt‐on‐cobalt hydroxide nanoparticles (NPs) has been proved in Ru/Co/Co(OH)2/G by X‐ray diffraction (XRD), X‐ray photoelectron spectroscopy (XPS), transmission electron microscope (TEM), high resolution TEM (HRTEM), scanning transmission electron microscopy‐energy dispersive X‐ray spectroscopy (STEM‐EDS) elemental line scanning and mapping analysis, and high‐sensitivity low‐energy ion scattering (HS‐LEIS) measurement techniques. The Ru/Co/Co(OH)2/G catalyst showed excellent catalytic activity and 100% selectivity toward decalin for naphthalene hydrogenation reaction at the reaction temperature of 100 °C under initial 4.48 MPa hydrogen pressure probably owing to the synergetic effect of Ru, Co and Co(OH)2 active sites.
Selective Carbon Dioxide Capture Using Silica‐Supported Polyaminals
Authors: Senthilkumaran Marimuthu , Saravanan Chokalingam , Eswaran Lakshmanan , Puthiaraj Pillaiyar , Mareeswaran Paulpandian Muthu
Published: August 2019

The development of a stable CO2 sequestration material is an urgent need for effective CO2 capture applications. In this sense, the silica supported materials are envisaged as promising materials. In this work the synthesis of silica supported polyaminals (Si‐PA‐1 and Si‐PA‐2) by single step condensation is achieved and characterized by FT‐IR and solid‐state NMR spectral techniques. The surface morphology and crystallinity are studied using SEM and PXRD techniques. The BET surface of the Si‐PA‐1 and Si‐PA‐2 is around 155 m2/g which is demonstrated using N2 adsorption. The CO2 uptake for Si‐PA‐1 and Si‐PA‐2 are observed around 45 mg/g. The high selectivity of CO2 over N2 (180.6) and considerable selectivity of CO2 over CH4 (38.7) are observed. Two types of adsorption isotherm models (Langmuir and Freundlich model) are used to evaluate isotherm parameters. Thermodynamic parameters such as Gibb's free energy, change in enthalpy and entropy are calculated from Van't Hoff equation and these results suggest that the adsorption is spontaneous and exothermic process. The physical interaction between Si‐PAs and CO2 is confirmed by the heat of adsorption (37‐22 KJ/mol) evaluated from Clausius–Clapeyron equation.
Photochromic Properties of Novel One‐pot Multicomponent Synthesized Tetraarylimidazoles
Authors: Nadamani Meysam Pasandideh , Mahmoodi Nosrat O. , Mamaghani Manouchehr , Zanjanchi Mohammad Ali , Nahzomi Hossein Taherpour
Published: August 2019

Acetic acid mediated synthesis of novel tetraarylimidazoles derivatives has been reported via multicomponent reaction of benzil or phenanthrene‐9,10‐dione, NH4OAc, vanillin and aniline derivatives under microwave irradiation. Several novel tetraarylimidazole derivatives, phenanthroimidazole and bis‐tetraphenylimidazole bearing a 2‐methoxyphenol substituent at position 2 of imidazole ring were prepared. The advantages of this method are the one‐pot preparation of compounds, in short reaction times (4‐7 min) and good yields. All synthesized compounds with a 2‐methoxyphenol substituent at position 2 of imidazole ring exhibited good photochromic behavior. The photoisomerization can be performed from ground state to triplet excited state according to TD‐DFT calculation. The results showed that the presence of ortho‐methoxy substituent to hydroxyl substitution has the greatest effect on photochromic properties of target compounds. Furthermore, a pattern was successfully visualized upon UV light irradiation, which suggested that these compounds can be served as a security ink or an anti‐counterfeiting mark for photo printing.
CoFe2O4@SiO2‐PA‐CC‐Guanidine MNPs as an Efficient Catalyst for the One‐Pot, Four‐Component Synthesis of Pyrazolopyranopyrimidines
Authors: Rostami Hedieh , Shiri Lotfi
Published: August 2019

A new and mild protocol for the synthesis of pyrazolopyranopyrimidines using CoFe2O4@SiO2‐PA‐CC‐Guanidine MNPs in water at room temperature was reported. Pyrazolopyranopyrimidine derivatives were synthesized from reaction between hydrazine hydrate, ethylacetoacetate, aldehydes and barbituric acid derivatives in good to excellent yields. This nanocatalyst was characterized by FT‐IR spectroscopy, scanning electron microscopy (SEM), energy dispersive X‐ray spectroscopy (EDX), X‐ray diffraction (XRD), Thermogravimetric analysis (TGA) and vibrating sample magnetometry (VSM) techniques. CoFe2O4@SiO2‐PA‐CC‐Guanidine MNPs have high activity and easy separation from the reaction mixture. This magnetic nanocatalyst has recovery capability and can be reused for the several times.
Realization of Visible Light Photocatalysis by Wide Band Gap Pure SnO2 and Study of In2O3 Sensitization Porous SnO2 Photolysis Catalyst
Authors: Peng Li , Xiao Yang , Wang Xiao‐li , Feng Da‐wei , Yu Hui , Dong Xiang‐ting
Published: August 2019

SnO2 is a wide band gap semiconductor which has no photocatalysis under visible light. In this study, the disordered porous SnO2 precursor was constructed which showed obvious photocatalysis under visible light irradiation. Its degradation rate to RhB was 51.66% after 100 min, and the amount of hydrogen produced could reach 11.13 mmol⋅g−1 after 3.5 h under visible light irradiation. And then, In2O3 was used as sensitizer to increase the specific surface area of porous SnO2 matrix. The specific surface area of porous SnO2 was increased from 167.355 m2⋅g−1 to 544.394 m2⋅g−1 when the doping amount of In2O3 was 1.5 wt.%. The photocatalytic properties of the porous SnO2 matrix was also vastly increased. The highest photocatalytic activity was observed for the In2O3/SnO2‐1.5 sample, the degradation rate of RhB was 93.50% after 100 min which was 1.85 times of the SnO2 matrix, and the hydrogen production rate could reach 21.51 mmol⋅g−1 after 3.5 h which was 1.94 times of the SnO2 matrix under visible light irradiation. The catalyst had a much higher stability which could be recycled utilize.
Effects of single and combined immunotherapy approach targeting amyloid β protein and α‐synuclein in a dementia with Lewy bodies–like model
Authors: Mandler Markus , Rockenstein Edward , Overk Cassia , Mante Michael , Florio Jazmin , Adame Anthony , Kim Changyoun , Santic Radmila , Schneeberger Achim , Mattner Frank , Schmidhuber Sabine , Galabova Gergana , Spencer Brian , Masliah Eliezer , Rissman Robert A.
Published: August 2019

Introduction

Immunotherapeutic approaches targeting amyloid β (Aβ) protein and tau in Alzheimer's disease and α‐synuclein (α‐syn) in Parkinson's disease are being developed for treating dementia with Lewy bodies. However, it is unknown if single or combined immunotherapies targeting Aβ and/or α‐syn may be effective.

Methods

Amyloid precursor protein/α‐syn tg mice were immunized with AFFITOPEs® (AFF) peptides specific to Aβ (AD02) or α‐syn (PD‐AFF1) and the combination.

Results

AD02 more effectively reduced Aβ and pTau burden; however, the combination exhibited some additive effects. Both AD02 and PD‐AFF1 effectively reduced α‐syn, ameliorated degeneration of pyramidal neurons, and reduced neuroinflammation. PD‐AFF1 more effectively ameliorated cholinergic and dopaminergic fiber loss; the combined immunization displayed additive effects. AD02 more effectively improved buried pellet test behavior, whereas PD‐AFF1 more effectively improved horizontal beam test; the combined immunization displayed additive effects.

Discussion

Specific active immunotherapy targeting Aβ and/or α‐syn may be of potential interest for the treatment of dementia with Lewy bodies.
System analysis of turbo-electric and hybrid-electric propulsion systems on a regional aircraft
Authors: Gesell Hendrik , Wolters Florian , Plohr Martin
Published: August 2019

The increasing environmental requirements in the air transport sector pose great challenges to the aviation industry and are key drivers for innovation. Besides various approaches for increasing the efficiency of conventional gas turbine engines, electric propulsion systems have moved into the focus of aviation research. The first electric concepts are already in service in general aviation. This study analyses the potentials of electric and turbo hybrid propulsion systems for commercial aviation. Its purpose is to compare various architectures of electrical powertrains with a conventional turboprop on a regional aircraft, similar to the ATR 72, on engine and flight mission levels. The considered architectures include a turbo-electric (power controlled and direct driven), hybrid-electric (serial and parallel) and a pure electric concept. Their system weights are determined using today’s technology assumptions. With the help of performance models and flight mission calculations the impact on fuel consumption, CO
${}_{2}$
emissions and aircraft performance is evaluated.
Social Media Usage During Disasters: Exploring the Impact of Location and Distance on Online Engagement
Authors: Deng Qing , Liu Yi , Liu Xiaodong , Zhang Hui , Deng Xiaolong
Published: August 2019

Social media play an important role in emergency management. The location of citizens and distance from a disaster influence the social media usage patterns. Using the Tianjin Port Explosion, we apply the correlation analysis and regression analysis to explore the relationship between online engagement and location. Citizens’ online engagement is estimated by social media. Three dimensions of the psychological distance – spatial, temporal, and social distances – are applied to measure the effects of location and distance. Online engagement is negatively correlated to such 3 kinds of the distance, which indicates that citizens may pay less attention to a disaster that happens at a far away location and at an area of less interaction or at a relatively long period of time. Furthermore, a linear model is proposed to measure the psychological distance. The quantification relationship between online engagement and psychological distance is discussed. The result enhances our understanding of social media usage patterns related to location and distance. The study gives a new insight on situation awareness, decision-making during disasters.
Formation and interaction of multiple secondary flow vortical structures in a curved pipe: transient and oscillatory flows
Authors: Najjari Mohammad Reza , Cox Christopher , Plesniak Michael W.
Published: August 2019

Transient, steady and oscillatory flows in a $180^{\circ }$ curved pipe are investigated both numerically and experimentally to understand secondary flow vortex formation and interactions. The results of numerical simulations and particle image velocimetry experiments are highly correlated, with a low error. To enable simulations in a smaller domain with shorter inlet section, an analytical solution for the unsteady Navier–Stokes equation is obtained with non-zero initial conditions to provide physical velocity profiles for the simulations. The vorticity transport equation is studied and its terms are balanced to find the mechanism of vorticity transfer to structures in the curved pipe. Several vortices are identified via various vortex identification (ID) methods and their results are compared. Isosurfaces of the $\unicode[STIX]{x1D706}_{2}$ vortex ID are used to explain the temporal and spatial evolution of vortices in the curved pipe. Eigenvalues and eigenvectors of the velocity gradient tensor are calculated for the swirling strength vortex ID method, which also determines vortex axis orientation. The classical Lyne vortex in oscillatory flow with an inviscid core is also revisited and its results are compared with the transient and steady flows. These in-depth analyses provide a better understanding and characterization of vortical structures in the curved pipe flow. Our findings show that, although there are some visual similarities between cross-sectional views of steady/transient flows and oscillatory flows, the structure herein designated as Lyne-type vortex detected in the cross-sections (under steady, transient and pulsatile flows) is not the same as the classical Lyne vortex pair (in oscillatory flows).
A Postcolonial Dilemma Tale from the Harbour of St. Thomas in the US Virgin Islands
Authors: Brichet Nathalia
Published: August 2019

The port of Charlotte Amalie on St. Thomas has long been a vibrant centre for ship trafficking in the Caribbean, as it was during Danish colonial rule starting in 1672. In 1917, Denmark officially sold and left what became the US Virgin Islands. Not everybody left, though. The Danish-owned West Indian Company, which owned the majority of the St. Thomas port and its attendant facilities, stayed until 1993. At that point the harbour was sold to the Virgin Islanders, who for some time had complained about the fact that a Danish company still profited from the islands. The harbour of Charlotte Amalie, which is my central analytical unit here, thus provides a lens through which to approach Danish colonial imprints.

The harbour is and has been characterised by activities of a temporary and opportunistic kind: industries blossom, people and crops from far away get uprooted and replanted in the Caribbean, businesses provide work for locals, goods are shipped out to be consumed in other places. The transitory nature of projects designed by people elsewhere, I argue, is part of what colonialism is. As I will show, the traces of such projects appear not only as particular ecologies but also as dilemmas to be grappled with long after the foreign decision-makers have left. My approach to colonial legacies on the Virgin Islands, then, mobilises the shifting flows of people, commodities, and interests shipped in and out of Charlotte Amalie to leave behind altered landscapes that are continuously debated.
Village Elections, Grassroots Governance and the Restructuring of State Power: An Empirical Study in Southern Peri-urban China
Authors: Wong Siu Wai , Tang Bo-sin , Liu Jinlong
Published: August 2019

China's urbanization has revitalized grassroots governance under which millions of villagers have become increasingly keen to participate in grassroots elections and influence decision making in their village affairs. To maintain its political legitimacy over a rapidly transforming society, the authoritarian party-state has progressively promoted open, competitive grassroots elections in response to the increasing demand by villagers for more public participation. Based on in-depth field research in urbanizing villages in southern China, this article provides an empirical analysis of how the local state has adopted different interventionist strategies in elections to support villagers’ active participation while sustaining its direct leadership over daily village governance. Our findings explain why the recent development of open and transparent grassroots elections is reinforcing the ruling capacity of the socialist state rather than enhancing self-governance and grassroots democracy, although villagers now have more opportunities to defend their economic and social rights through elections.
Does Non-Quota Strategy Matter? A Comparative Study on Candidate Selection and Women's Representation at the Local Level in Germany
Authors: Ruf Florian
Published: August 2019

The intraparty mechanisms through which parties recruit, motivate, and select their candidates are central explanatory factors for the representation of women. This article analyzes the effects of intraparty factors on women's representation by measuring the impact of (1) parties’ non-quota strategies at the regional level—such as establishing women's sections, mentoring programs, or campaign funding for women—and (2) central party gatekeepers at the local level. Exploiting an original, newly compiled data set consisting of 1,475 electoral lists from the 2014 local council elections in the German state of Baden-Wuerttemberg, this article shows that parties’ non-quota strategies and central gatekeepers play crucial roles in determining the share of women on local party tickets. This means that who runs for office is, in this case, a question of intraparty dynamics. These dynamics are caused by different mechanisms of non-quota strategies and gender-biased candidate selection combined with interparty effects of local party competition and left-party strength. The almost consistent conditions that the subnational level provides show that the parties’ capacities (or lack thereof) for gendered recruitment is one major explanatory factor and should be tested at least in cross-national comparisons.
Measurement method for characterizing a millimeter-wave traveling-wave power combiner using in-situ test accessories
Authors: Sun Honglei , Zhu Xiao-Wei , Shi Xuesong , Liu Ruijia
Published: August 2019

This paper presents a novel assessment method that minimizes test-fixture-induced errors in non-coaxial power combiner measurement by extending the port reduction method. This method involves terminating certain ports to acquire the scattering matrix of an N-port network from the scattering matrix measured at a reduced port order. The entire DUT scattering matrix is obtained from multiple scanning measurements, which are taken from partial coaxial accessible ports, based on a set of configurable terminating states. This advantage is leveraged to exclude a major portion of coaxial launch structures that would otherwise be incorporated in the conventional multiport test fixture. An analogous concept here is applied to measure a waveguide traveling-wave power combiner. A sandwiched twin structure, containing a divider/combiner pair with certain auxiliary through-type components cushioned between them, is utilized to assess the combiner characteristics. A theoretical framework of the proposed method was established to test its potential precision. Thereafter, an in-situ implementation was conducted to test its practical application on a traveling-wave combined amplifier prototype operating at the Q-band (33–39 GHz).
Compact transition from CBCPW to substrate integrated suspended line (SISL) for operation up to 46 GHz
Authors: Parment F. , Ghiotto A. , Vuong T.-P. , Carpentier L. , Wu K.
Published: August 2019

A compact transition between conductor-backed coplanar waveguide (CBCPW) and substrate integrated suspended line (SISL) is presented. Compared to the reported transitions from CBCPW to SISL, performance and compactness are improved. For demonstration purpose, a multilayer transition is designed and fabricated for operation up to 46 GHz. Experimental results, based on an electronic calibration and thru–reflect–line calibration allowing measurement in the 0.01–50 GHz frequency range, demonstrate an insertion loss of 0.59 ± 0.51 dB with a return loss of better than 10 dB in the 10 MHz to 46 GHz frequency range.
The Curious Case of Ghana/Côte d'Ivoire: A Consistent Approach to Hydrocarbon Activities in the Disputed Area?
Authors: ZHAO Bin
Published: August 2019

The Ghana/Côte d'Ivoire case is the first time that an ITLOS ad hoc chamber has addressed the lawfulness of unilateral hydrocarbon activities in a disputed maritime area. This paper analyzes the Chamber's ruling on Côte d'Ivoire's submission no. 2, which covers several important issues: the jurisdiction of the Chamber to decide on submission no. 2, the alleged violation of sovereign rights, and the alleged violation of Article 83(3) of UNCLOS. The paper argues that the Chamber's jurisdictional basis of forum prorogatum is questionable, and that there are inconsistent approaches between the Judgment and the Order of the provisional measures. Additionally, there are not only inconsistent understandings of the “Ivorian maritime area” within the same submission no. 2 by the Chamber, but also a logical gap in the Chamber's reasoning with regard to submission no. 2(iii). Consequently, the Chamber's inconsistent approaches may jeopardize the persuasiveness of its judgment.
The Culmination of an Oblique Time‐Transgressive Arc Continent Collision: The Pollino Massif Between Calabria and the Southern Apennines, Italy
Authors: Filice Francesco , Seeber Leonardo
Published: August 2019

The Pollino Massif is the most southeastern outcrop of the Apennine core. It marks the transition between Apenninic shortening and extension, respectively, SE and NW of the massif and is also the cusp of a southeastward plunge that characterizes the submerged Apennines. The SE limit of NE‐SW extension merges with the east limit of Tyrrhenian extension in Calabria. This strategic position is expected to transition southeastward in the progressive oblique collision of the Calabrian forearc and Apulia. We test this hypothesis using published results and new field data. The time‐transgressive emergence of basins on the Apennine thrust wedge is quantitatively consistent with the ESE rollback of the Calabrian arc. Specifically, a thrust‐normal slip reversal on a SW dipping fault is responsible for the tectonic collapse that lead to the Mercure Basin along strike NW of the Pollino Massif and to an east‐to‐west reversal of drainage. This reversal is timed by an intermediate stage of trapped internal drainage with Mid‐Pleistocene lacustrine sedimentation, but it may young to SE as the normal displacement on the border fault decreases gradually to SE and vanishes near the apex of the massif. On the SE side of the massif, contractional tectonics persists at least into the Mid‐Pleistocene and likely later, while NE‐SW extension is absent. Prominent normal faults in that area accommodate range‐parallel extension and are coupled with the thrust faults. The combination of longitudinal extension with a counterclockwise rotation of hanging‐wall units and thrust directivity can account for the final setting in the Apennines.
Correlated Time‐Varying Magnetic Fields and the Core Size of Mercury
Authors: Wardinski I. , Langlais B. , Thébault E.
Published: August 2019

Mercury is characterized by a very peculiar magnetic field, as it was revealed by the MESSENGER mission. Its internal component is highly axisymmetric, dominated by the dipole, and very weak. This in turns leads to a very dynamic magnetosphere. It is known that there exist relationships between the internally generated field and the external field, although their dynamics are complex. In this study we derive steady and time‐varying spherical harmonic models of Mercury's magnetic field using MESSENGER measurements and interpret these models both in terms of correlated features and of the internal structure of Mercury. The influence of the hemispheric data distribution of MESSENGER is evaluated to grant the robustness of our models. We find a quadrupole‐to‐dipole ratio of 0.27 for the steady magnetic field. The time‐varying models reveal periodic and highly correlated temporal variations of internal and external origins. This argues for externally inducing and internally induced sources. The main period is 88 days, the orbital period of Mercury around the Sun. There is no measurable time lag between variations of external and internal magnetic fields, which place an upper limit of 1 S/m for the mantle conductivity. Finally, the compared amplitudes of external and internal time‐varying field lead to an independent (from gravity studies) estimate of the conductive core radius, at 2,060 ± 22 km. These analyses will be further completed with the upcoming BepiColombo mission and its magnetic field experiment, but the presented results already lift the veil on some of the magnetic oddities at Mercury.
Initiation and Flow Conditions of Contemporary Flows in Martian Gullies
Authors: de Haas T. , McArdell B. W. , Conway S. J. , McElwaine J. N. , Kleinhans M. G. , Salese F. , Grindrod P. M.
Published: August 2019

Understanding the initial and flow conditions of contemporary flows in Martian gullies, generally believed to be triggered and fluidized by CO2 sublimation, is crucial for deciphering climate conditions needed to trigger and sustain them. We employ the RAMMS (RApid Mass Movement Simulation) debris flow and avalanche model to back calculate initial and flow conditions of recent flows in three gullies in Hale crater. We infer minimum release depths of 1.0–1.5 m and initial release volumes of 100–200 m3. Entrainment leads to final flow volumes that are ∼2.5–5.5 times larger than initially released, and entrainment is found necessary to match the observed flow deposits. Simulated mean cross‐channel flow velocities decrease from 3–4 m/s to ∼1 m/s from release area to flow terminus, while flow depths generally decrease from 0.5–1 to 0.1–0.2 m. The mean cross‐channel erosion depth and deposition thicknesses are ∼0.1–0.3 m. Back‐calculated dry‐Coulomb friction ranges from 0.1 to 0.25 and viscous‐turbulent friction between 100 and 200 m/s2, which are values similar to those of granular debris flows on Earth. These results suggest that recent flows in gullies are fluidized to a similar degree as are granular debris flows on Earth. Using a novel model for mass flow fluidization by CO2 sublimation we are able to show that under Martian atmospheric conditions very small volumetric fractions of CO2 of ≪1% within mass flows may indeed yield sufficiently large gas fluxes to cause fluidization and enhance flow mobility.
Updating a Crucial Source of Sea Surface Temperature Data
Authors: Cook Terri
Published: August 2019

A new version of a major sea surface temperature data set reduces systematic errors in measurements of one of the most important indicators of the state of Earth’s climate system.
Fate of Hydrous Fe‐Rich Silicate Melt in Earth's Deep Mantle
Authors: Du Zhixue , Deng Jie , Miyazaki Yoshinori , Mao Ho‐kwang , Karki Bijaya B. , Lee Kanani K. M.
Published: August 2019

Density of silicate melt dictates melt migration and establishes the gross structure of Earth's interior. However, due to technical challenges, the melt density of relevant compositions is poorly known at deep mantle conditions. Particularly, water may be dissolved in such melts in large amounts and can potentially affect their density at extreme pressure and temperature conditions. Here we perform first‐principles molecular dynamics simulations to evaluate the density of Fe‐rich, eutectic‐like silicate melt (E melt) with varying water content up to about 12 wt %. Our results show that water mixes nearly ideally with the nonvolatile component in silicate melt and can decrease the melt density significantly. They also suggest that hydrous melts can be gravitationally stable in the lowermost mantle given its likely high iron content, providing a mechanism to explain seismically slow and dense layers near the core‐mantle boundary.
Pliocene Warmth Consistent With Greenhouse Gas Forcing
Authors: Tierney Jessica E. , Haywood Alan M. , Feng Ran , Bhattacharya Tripti , Otto‐Bliesner Bette L.
Published: August 2019

With CO2 concentrations similar to today (410 ppm), the Pliocene Epoch offers insights into climate changes under a moderately warmer world. Previous work suggested a low zonal sea surface temperature (SST) gradient in the tropical Pacific during the Pliocene, the so‐called “permanent El Niño.” Here, we recalculate SSTs using the alkenone proxy and find moderate reductions in both the zonal and meridional SST gradients during the mid‐Piacenzian warm period. These reductions are captured by coupled climate model simulations of the Pliocene, especially those that simulate weaker Walker circulation. We also produce a spatial reconstruction of mid‐Piacenzian warm period Pacific SSTs that closely resembles both Pliocene and future, low‐emissions simulations, a pattern that is, to a first order, diagnostic of weaker Walker circulation. Therefore, Pliocene warmth does not require drastic changes in the climate system—rather, it supports the expectation that the Walker circulation will weaken in the future under higher CO2.
Statistical Modeling of Tidal Weather in the Mesosphere and Lower Thermosphere
Authors: Vitharana Ashan , Zhu Xuwen , Du Jian , Oberheide Jens , Ward William E.
Published: August 2019

We study the statistical properties of tidal weather (variability period <30 days) of DW1 amplitude using the extended Canadian Middle Atmospheric Model (eCMAM) and Sounding of the Atmosphere using Broadband Emission Radiometry (SABER). A hierarchy of statistical models, for example, the autoregressive (AR), vector AR, and parsimonious vector AR models, are built to predict tidal weather. The quasi 23‐day oscillation found in the tidal weather is a key parameter in the statistical models. Comparing to the more complex vector AR and parsimonious vector AR models, which consider the spatial correlations of tidal weather, the simplest AR model can predict one‐day tidal weather with an accuracy of 89% (R2: correlation coefficient squared). In the AR model, 23 coefficients at each latitude and height are obtained from seven years of eCMAM data. Tidal weather is predicted via a linear combination of 23 days of tidal weather data prior to the prediction day. Different sensitivity tests are performed to prove the robustness of these coefficients. These coefficients obtained from eCMAM are in very good agreement with those from SABER. SABER tidal weather is predicted with an accuracy of 86% and 87% at one day by the AR models with coefficients from eCMAM and SABER, respectively. The five‐day forecast accuracy is between 60 and 65%.
The CR of Evaporation: A Calibration‐Free Diagnostic and Benchmarking Tool for Large‐Scale Terrestrial Evapotranspiration Modeling
Authors: Ma Ning , Szilagyi Jozsef
Published: August 2019

Monthly evapotranspiration (ET) rates for 1979–2015 were estimated by the latest, calibration‐free version of the complementary relationship (CR) of evaporation over the conterminous United States. The results were compared to similar estimates of three land surface models (Noah, VIC, Mosaic), two reanalysis products (National Centers of Environmental Protection Reanalysis II, ERA‐Interim), two remote‐sensing‐based (Global Land Evaporation Amsterdam Model, Penman‐Monteith‐Leuning) algorithms, and the spatially upscaled eddy‐covariance ET measurements of FLUXNET‐MTE. Model validations were performed via simplified water‐balance derived ET rates employing Parameter‐Elevation Regressions on Independent Slopes Model precipitation, United States Geological Survey two‐ and six‐digit Hydrologic Unit Code (HUC2 and HUC6) discharge, and terrestrial water storage anomalies from Gravity Recovery and Climate Experiment, the latter for 2003–2015. The CR outperforms all other multiyear mean annual HUC2‐averaged ET estimates with root‐mean‐square error = 51 mm/year, R = 0.98, relative bias of −1%, and Nash‐Sutcliffe efficiency = 0.94, respectively. Inclusion of the Gravity Recovery and Climate Experiment data into the annual water balances for the shorter 2003–2015 period does not have much effect on model performance. Similarly, the CR outperforms all other models for the linear trend of the annual ET rates over the HUC2 basins. Over the significantly smaller HUC6 basins where the water‐balance validation is more uncertain, the CR still outperforms all other models except FLUXNET‐MTE, which has the advantage of possible local ET measurements, a benefit that clearly diminishes at the HUC2 scale. As the employed CR is calibration‐free and requires only very few meteorological inputs, yet it yields superior ET performance at the regional scale, it may serve as a diagnostic and benchmarking tool for more complex and data intensive models of terrestrial evapotranspiration rates.
Consumption of a Leuconostoc holzapfelii-enriched synbiotic beverage alters the composition of the microbiota and microbial extracellular vesicles
Authors: Yang Jinho , McDowell Andrea , Kim Eun Kyoung , Seo Hochan , Yum Kyujin , Lee Won Hee , Jee Young-Koo , Kim Yoon-Keun
Published: August 2019

Synbiotics, the combination of probiotics and prebiotics, are known to confer health benefits via intestinal microbiota modulation. However, significant intestinal microbiota alterations can be difficult to determine in intervention studies based on solely bacterial stool metagenomic analysis. Intestinal microbiota constituents secrete 20–200-nm-sized extracellular vesicles (EVs) containing microbial DNA, proteins, and lipids that are distributed throughout the body, providing an alternative target for microbiota metagenomic analysis. Here, we determined the impact of a synbiotic beverage enriched with the kimchi-derived bacterium Leuconostoc holzapfelii (L. holzapfelii) on the intestinal microbiota and local and circulatory microbiota-derived EV composition of healthy Korean adults. We isolated microbial DNA from stool bacteria, stool EVs, and urinary EVs and conducted next-generation sequencing of the 16S rDNA V3–V4 regions before and after synbiotic consumption. The species diversity of circulating urinary EVs was significantly increased after synbiotic consumption, while stool bacterial and EV diversity remained unchanged. Furthermore, we found that while a single genus was decreased among the stool bacteria constituents, stool EVs and urinary EVs showed significant alterations in four and eight genera, respectively. Blood chemistry assays revealed that synbiotic consumption significantly lowered aspartate aminotransferase (AST) serum levels, particularly in subjects with starting levels above the normal range (>40 UI/L). In conclusion, the L. holzapfelii-enriched synbiotic beverage greatly altered serum AST levels and microbial EV composition in urine and stool, while only minor changes were observed in the gut microbiota composition. Based on these findings, we suggest the potential use of microbiota-derived EVs as surrogate markers in future predictive diagnosis studies.
circHECTD1 facilitates glutaminolysis to promote gastric cancer progression by targeting miR-1256 and activating β-catenin/c-Myc signaling
Authors: Cai Juan , Chen Zhiqiang , Wang Jinguo , Wang Junfeng , Chen Xianjun , Liang Linhu , Huang Min , Zhang Zhengrong , Zuo Xueliang
Published: August 2019

Circular RNAs (circRNAs) have emerged as crucial regulators of human cancers. Glutaminolysis supplies cancer cells with adequate nitrogen and carbon to replenish the tricarboxylic acid cycle, contributing to the survival and progression of tumor cells. However, the association between circRNAs and glutaminolysis remains unclear. In this study, we showed that circHECTD1 expression was markedly upregulated in gastric cancer (GC) and was associated with lymph node metastasis and American Joint Committee on Cancer stage. The circHECTD1 expression level was found to be an independent prognostic factor for GC patients. circHECTD1 knockdown inhibited GC cell glutaminolysis, proliferation, migration, and invasion, whereas circHECTD1 overexpression promoted GC progression. Dual-luciferase and RNA immunoprecipitation assays demonstrated that miR-1256 was a direct downstream target of circHECTD1. circHECTD1 targeted miR-1256 and subsequently increased the expression level of USP5. The circHECTD1/miR-1256/USP5 axis exerted its tumor-promoting effects by activating the downstream β-catenin/c-Myc signaling pathway. In vivo mouse models further verified the oncogenic roles of circHECTD1 in GC. Our results revealed that circHECTD1 is a glutaminolysis-associated circRNA that promotes GC progression. The circHECTD1/miR-1256/USP5 axis could thus be used as a therapeutic target for GC.
Site-specific phosphorylation of Fbxw7 by Cdk5/p25 and its resulting decreased stability are linked to glutamate-induced excitotoxicity
Authors: Ko Yeon Uk , Kim Chiho , Lee Juhyung , Kim Dana , Kim Yoonkyung , Yun Nuri , Oh Young J.
Published: August 2019

Cyclin-dependent kinase 5 (Cdk5) is a serine/threonine protein kinase that regulates brain development and neurodegeneration. Cdk5 is activated by p25 that is generated from calpain-dependent cleavage of p35. The generation of p25 is responsible for the aberrant hyper-activation of Cdk5, which causes neurodegeneration. Using in vitro assays, we discovered that F-box/WD repeat-containing protein 7 (Fbxw7) is a new substrate of Cdk5. Additionally, Cdk5-dependent phosphorylation of Fbxw7 was detected in the presence of p25, and two amino acid residues (S349 and S372) were determined to be major phosphorylation sites. This phosphorylation was eventually linked to decreased stability of Fbxw7. Using a culture model of cortical neurons challenged with glutamate, we confirmed that decreased stability of Fbxw7 was indeed Cdk5-dependent. Furthermore, diminished levels of Fbxw7 led to increased levels of transcription factor AP-1 (c-Jun), a known substrate of Fbxw7. Given that previous reports demonstrate that c-Jun plays a role in accelerating neuronal apoptosis in these pathological models, our data support the concepts of a molecular cascade in which Cdk5-mediated phosphorylation of Fbxw7 negatively regulates Fbxw7 expression, thereby contributing to neuronal cell death following glutamate-mediated excitotoxicity.
Extracorporeal photochemotherapy induces bona fide immunogenic cell death
Authors: Tatsuno Kazuki , Yamazaki Takahiro , Hanlon Douglas , Han Patrick , Robinson Eve , Sobolev Olga , Yurter Alp , Rivera-Molina Felix , Arshad Najla , Edelson Richard L. , Galluzzi Lorenzo
Published: August 2019

Extracorporeal photochemotherapy (ECP) is employed for the management of cutaneous T cell lymphoma (CTCL). ECP involves the extracorporeal exposure of white blood cells (WBCs) to a photosensitizer, 8-methoxypsoralen (8-MOP), in the context of ultraviolet A (UVA) radiation, followed by WBC reinfusion. Historically, the therapeutic activity of ECP has been attributed to selective cytotoxicity on circulating CTCL cells. However, only a fraction of WBCs is exposed to ECP, and 8-MOP is inactive in the absence of UVA light, implying that other mechanisms underlie the anticancer effects of ECP. Recently, ECP has been shown to enable the physiological differentiation of monocytes into dendritic cells (DCs) that efficiently cross-present tumor-associated antigens (TAAs) to CD8+ T lymphocytes to initiate cognate immunity. However, the source of TAAs and immunostimulatory signals for such DCs remains to be elucidated. Here, we demonstrate that 8-MOP plus UVA light reduces melanoma cell viability along with the emission of ICD-associated danger signals including calreticulin (CALR) exposure on the cell surface and secretion of ATP, high mobility group box 1 (HMGB1) and type I interferon (IFN). Consistently, melanoma cells succumbing to 8-MOP plus UVA irradiation are efficiently engulfed by monocytes, ultimately leading to cross-priming of CD8+ T cells against cancer. Moreover, malignant cells killed by 8-MOP plus UVA irradiation in vitro vaccinate syngeneic immunocompetent mice against living cancer cells of the same type, and such a protection is lost when cancer cells are depleted of calreticulin or HMGB1, as well as in the presence of an ATP-degrading enzyme or antibodies blocking type I IFN receptors. ECP induces bona fide ICD, hence simultaneously providing monocytes with abundant amounts of TAAs and immunostimulatory signals that are sufficient to initiate cognate anticancer immunity.
Successful application of prime and pull strategy for a therapeutic HSV vaccine
Authors: Bernstein David I. , Cardin Rhonda D. , Bravo Fernando J. , Awasthi Sita , Lu Peiwen , Pullum Derek A. , Dixon David A. , Iwasaki Akiko , Friedman Harvey M.
Published: August 2019

One promising approach for a herpes simplex virus vaccine uses a vaccine to prime and a chemoattractant to pull immune cells into the genital tract. We evaluated subunit vaccines (prime) and imiquimod (pull) in the guinea pig (gp) model of recurrent Herpes simplex virus type-2 (HSV-2). Following vaginal HSV-2 infection, gps were vaccinated with various combination of glycoproteins and adjuvant with or without subcutaneous or local applications of imiquimod after infection. Animals were examined daily for recurrent lesions and vaginal swabs collected for recurrent shedding. Although both the vaccines alone and imiquimod alone reduced recurrent HSV disease, the combination of local imiquimod and vaccine (Prime and Pull) was the most effective. In the first study, immunization with the trivalent vaccine alone or imiquimod alone decreased recurrent disease. However, the largest decrease was with the combination of vaccine and local imiquimod (P < 0.001 vs. placebo or vaccine alone). No effect on recurrent shedding was observed. In the second study, recurrent disease scores were similar in the PBS control group and the trivalent-immunized group treated with subcutaneous imiquimod however, significant reductions with glycoprotein vaccines and local imiquimod (p < 0.01 vs. placebo) were noted. The number of qPCR-positive recurrent swabs, ranged from 5 to 11% in the vaccinated+local imiquimod groups compared 29% in the PBS control group (P < 0.05). No recurrent swab samples from vaccinated groups were culture positive. We conclude that the strategy of prime (subunit HSV vaccine) and topical pull (intravaginal/topical imiquimod) decreased recurrent HSV more effectively than vaccine alone.
Neurons-derived extracellular vesicles promote neural differentiation of ADSCs: a model to prevent peripheral nerve degeneration
Authors: Roballo Kelly Cristine Santos , da Silveira Juliano Coelho , Bressan Fabiana Fernandes , de Souza Aline Fernanda , Pereira Vitoria Mattos , Porras Jorge Eliecer Pinzon , Rós Felipe Augusto , Pulz Lidia Hildebrand , Strefezzi Ricardo de Francisco , Martins Daniele dos Santos , Meirelles Flavio Vieira , Ambrósio Carlos Eduardo
Published: August 2019

Potential mechanisms involved in neural differentiation of adipocyte derived stem cells (ADSCs) are still unclear. In the present study, extracellular vesicles (EVs) were tested as a potential mechanism involved in the neuronal differentiation of stem cells. In order to address this, ADSCs and neurons (BRC) were established in primary culture and co-culture at three timepoints. Furthermore, we evaluated protein and transcript levels of differentiated ADSCs from the same timepoints, to confirm phenotype change to neuronal linage. Importantly, neuron-derived EVs cargo and EVs originated from co-culture were analyzed and tested in terms of function, such as gene expression and microRNA levels related to the adult neurogenesis process. Ideal neuron-like cells were identified and, therefore, we speculated thein vivofunction of these cells in acute sciatic nerve injury. Overall, our data demonstrated that ADSCs in indirect contact with neurons differentiated into neuron-like cells. Neuron-derived EVs appear to play an important role in this process carrying SNAP25, miR-132 and miR-9. Additionally,in vivoneuron-like cells helped in microenvironment modulation probably preventing peripheral nerve injury degeneration. Consequently, our findings provide new insight of future methods of ADSC induction into neuronal linage to be applied in peripheral nerve (PN) injury.
Environmental influence on calcification of the bivalve Chamelea gallina along a latitudinal gradient in the Adriatic Sea
Authors: Mancuso Arianna , Stagioni Marco , Prada Fiorella , Scarponi Daniele , Piccinetti Corrado , Goffredo Stefano
Published: August 2019

Environmental factors are encoded in shells of marine bivalves in the form of geochemical properties, shell microstructure and shell growth rate. Few studies have investigated how shell growth is affected by habitat conditions in natural populations of the commercial clam Chamelea gallina. Here, skeletal parameters (micro-density and apparent porosity) and growth parameters (bulk density, linear extension and net calcification rates) were investigated in relation to shell sizes and environmental parameters along a latitudinal gradient in the Adriatic Sea (400 km). Net calcification rates increased with increasing solar radiation, sea surface temperature and salinity and decreasing Chlorophyll concentration in immature and mature shells. In immature shells, which are generally more porous than mature shells, enhanced calcification was due to an increase in bulk density, while in mature shells was due to an increase in linear extension rates. The presence of the Po river in the Northern Adriatic Sea was likely the main driver of the fluctuations observed in environmental parameters, especially salinity and Chlorophyll concentration, and seemed to negatively affect the growth of C. gallina.
Ecology, threats and conservation status of Carex buekii (Cyperaceae) in Central Europe
Authors: Więcław Helena , Šumberová Kateřina , Bosiacka Beata , Hrivnák Richard , Dajdok Zygmunt , Mesterházy Attila , Minuzzo Chiara , Martinetto Edoardo , Koopman Jacob
Published: August 2019

Carex buekiiis a tall sedge, forming large stands in wetlands, particularly in river floodplains across Central Europe and thus on many sites determining the typical appearance of riverine habitats. Our paper aims at increasing the knowledge on ecology ofC. buekiiand its role in the wetlands. Field data were collected in Poland, the Czech Republic, Slovakia, Hungary, and Italy.Carex buekiiusually occurs in nutrient rich habitats, but is also capable of colonising relatively nutrient-poor ones; it grows on both acidic and alkaline soils (pH 3.3–7.4) with diverse concentrations of assimilable elements (Ca, Mg, P, K). One of the most important ecological characteristics ofC. buekiiis its relationship to the floodplains of watercourses. It seems to be dependent on, or at least very tolerant to regular disturbances by streaming, floods and transport of sediments.Carex buekiiusually forms relatively uniform stands of its own association,Caricetum buekii. The species most frequently accompanyingC.buekiiareUrtica dioica,Calystegia sepium,Galium aparine,Rubus caesius,Phalaris arundinacea, andCirsium arvense. The sedge also occurs in the understorey of forests with e.g.Alnus glutinosa,Salix fragilis,Padus avium, andQuercus robur.Carex buekiiis able to colonise man-made or man-changed habitats such as railway embankments and roadsides or regulated river banks. Taking into account the IUCN Red List Criteria we propose to regardC.buekiias a least-concern (LC).