bluuebunny/crossref_metadata_2025 huggingface dataset:
HALE wing experiments and computational models to predict nonlinear flutter and dynamic response
Authors: Amato E. M. , Polsinelli C. , Cestino E. , Frulla G. , Joseph N. , Carrese R. , Marzocca P.
Published: June 2019

Experimental and numerical investigations into the linear and nonlinear aeroelastic behaviour of very flexible High Altitude Long Endurance (HALE) wings are conducted to assess the effect of geometrical nonlinearities on wings displaying moderate-to-large displacement. The study shows that the dynamic behaviour of wings under large deflection, and specifically the edgewise and torsion natural frequencies and modal characteristics, are largely affected by the presence of geometrical nonlinearities. A modular wing structure has been manufactured by rapid prototyping and it has been tested to characterise its dynamic and aeroelastic behaviour. At first, several simple isotropic cantilever beams with selected crosssections are numerically investigated to extract their modal characteristics. Experiments are subsequently conducted to validate the geometrically nonlinear dynamics behaviour due to high tip displacement and to understand the influence of the beam cross-section geometry. The structural dynamics and aeroelastic analysis of a very flexible modular selected wing is then investigated. Clean-wing wind-tunnel tests are carried out to assess flutter and dynamic response. The wind-tunnel model display interesting aeroelastic features including the substantial influence of the wing large deformation on its natural frequencies and modal characteristics.
Stagnation pressure effect on the supersonic minimum length nozzle design
Authors: Zebbiche T.
Published: June 2019

The aim of this work is to develop a calculation model based on the method of characteristics making it possible to study the effect of the stagnation pressure of the combustion chamber on the 2D and axisymmetric minimum length nozzle design giving a uniform and parallel flow at the exit section. The model is based on the use of the real gas approach. The co-volume and the intermolecular interaction effect are taken into account by the use of the Berthelot state equation. The effect of molecular vibration is considered in our model to evaluate the behaviour of gas at a high temperature. In this case, the stagnation pressure and the stagnation temperature are important parameters in our model. The resolution of the algebraic equations is done by the finite difference corrector predictor algorithm. The validation of the results is controlled by the convergence of the critical section ratios calculated numerically as obtained by the theory. The mass and the thrust are evaluated to improve the efficiency of the nozzle. The comparison is made with the high temperature and perfect gas models. The application is made for air.
A new species of dercetid (Teleostei, Aulopiformes) from the type Maastrichtian of southern Limburg, the Netherlands
Authors: Wallaard Jonathan J.W. , Fraaije René H.B. , Diependaal Henk J. , Jagt John W.M.
Published: June 2019

On the basis of dissociated and scattered skull bones and several types of scutes and scales of a single, large-sized individual, a new species of dercetid is recorded from the lower to middle portion of the Maastricht Formation (upper Gronsveld, Schiepersberg or Emael members) as formerly exposed at ’t Rooth quarry near Bemelen, east of Maastricht, the Netherlands. This new taxon,Pelargorhynchus grandisn. sp., the fifth dercetid recorded to date from the type area of the Maastrichtian Stage, is characterised by the presence of both large, smooth scutes and small ornamented scales, by the degree of curvature of skull bones, the presence of unfused premaxillae and the lack of teeth.
ON THE RECOGNITION OF RIGHT-ANGLED ARTIN GROUPS
Authors: BRIDSON MARTIN R.
Published: June 2019

There does not exist an algorithm that can determine whether or not a group presented by commutators is a right-angled Artin group.
A Unified Architecture for Physical and Ergonomic Human–Robot Collaboration
Authors: Ferraguti Federica , Villa Renzo , Talignani Landi Chiara , Maria Zanchettin Andrea , Rocco Paolo , Secchi Cristian
Published: June 2019

Industrial applications that involve working on and moving a heavy load or that constrain the operator to work in uncomfortable positions can take advantage of the assistance of a robotic assistant. In this paper, we propose an architecture for an ergonomic human–robot co-manipulation of objects of various shapes and weight. The object is carried by the robot and, thanks to an ergonomic planner, is positioned in the most comfortable way for the user. Furthermore, thanks to an admittance control with payload compensation, the user can easily adjust the position of the object for working on different parts of it. The proposed architecture is experimentally validated in a robotic cell including an ABB industrial robot.
Her Storyor their own stories? Digital game-based learning, student creativity, and creative writing
Authors: Lee Sangmin-Michelle
Published: June 2019

This qualitative study investigates a media transfer project in which a digital game was used to promote student creativity in an English as a foreign language (EFL) class. The paper first addresses the potential of opportunities for stimulating student creativity and motivation. Creativity has been highlighted as a core competency and has garnered considerable interest in many fields in recent years; however, creativity and creative writing are rarely cultivated in EFL writing classrooms. This study uses a digital game and designs a creative writing project to provide an authentic learning opportunity through which students were able to develop their creativity, use the target language in a meaningful way, and enjoy learning. A murder mystery game,Her Story, was selected because it provides a springboard for creative writing due to its fragmented and ambiguous narrative. Based on the game plot, 25 Korean university students reimagined the narrative in creative writing projects of their own. The study analyzes the students’ writing according to three constructs in Torrance’s model of creativity: originality, flexibility, and elaboration. The results demonstrate how the students’ writing exhibits considerable creativity in all three constructs. Student reflection papers and surveys indicate that participating in the project enhanced the students’ motivation for and engagement in learning.
‘Ces grandes dames, ça ne va pas souvent à l’église’: A corpus-based investigation of dislocation featuring co-referent clitic ça
Authors: Linares Emily
Published: June 2019

Although previous research has documented dislocations in which a dislocated noun phrase (NP) occurs with the co-referent pronounça(e.g., Carlier, 1996; Jones, 1996), this study represents the firstcorpus-drivenexamination focused on this syntactic construction. In examining examples identified in both an oral and a written corpus, the investigation serves to nuance the association between dislocation and orality (McLaughlin, 2011). The research also interrogates the relationship between dislocations featuring co-referent cliticçaand genericity. The extent to which this construction more frequently signals a pejorative attitude towards certain groups of animate NPs than others is also explored. Finally, this study advances methodological considerations for research on rare syntactic forms.
Alternative modelling and inference methods for claim size distributions
Authors: Raschke Mathias
Published: June 2019

The upper tail of a claim size distribution of a property line of business is frequently modelled by Pareto distribution. However, the upper tail does not need to be Pareto distributed, extraordinary shapes are possible. Here, the opportunities for the modelling of loss distributions are extended. The basic idea is the adjustment of a base distribution for their tails. The (generalised) Pareto distribution is used as base distribution for different reasons. The upper tail is in the focus and can be modelled well for special cases by a discrete mixture of the base distribution with a combination of the base distribution with an adapting distribution via the product of their survival functions. A kind of smoothed step is realised in this way in the original line function between logarithmic loss and logarithmic exceedance probability. The lower tail can also be adjusted. The new approaches offer the opportunity for stochastic interpretation and are applied to observed losses. For parameter estimation, a modification of the minimum Anderson Darling distance method is used. A new test is suggested to exclude that the observed upper tail is better modelled by a simple Pareto distribution. Q-Q plots are applied, and secondary results are also discussed.
High‐Resolution Measurements of the Cross‐Shock Potential, Ion Reflection, and Electron Heating at an Interplanetary Shock by MMS
Authors: Cohen Ian J. , Schwartz Steven J. , Goodrich Katherine A. , Ahmadi Narges , Ergun Robert E. , Fuselier Stephen A. , Desai Mihir I. , Christian Eric R. , McComas David J. , Zank Gary P. , Shuster Jason R. , Vines Sarah K. , Mauk Barry H. , Decker Robert B. , Anderson Brian J. , Westlake Joseph H. , Le Contel Olivier , Breuillard Hugo , Giles Barbara L. , Torbert Roy B. , Burch James L.
Published: June 2019

The Magnetospheric Multiscale (MMS) spacecraft obtained unprecedented high‐time resolution multipoint particle and field measurements of an interplanetary shock event on 8 January 2018. The spacecraft encountered the supercritical forward shock of a forward/reverse shock pair in the pristine solar wind upstream of the bow shock near the subsolar point as they neared apogee at ~25 RE. The high‐time resolution measurements from the four spacecraft, separated by only ~20 km, allowed direct measurement of particle distributions revealing evidence of electron heating and near specularly reflected ions. The cross‐shock potential is calculated directly from 3‐D electric field measurements. This is the first reported direct high temporal resolution (<1 s) observation at an interplanetary shock of near specularly reflected ions. Calculation of the cross‐shock potential yields a potential jump significant enough to reflect at least some of the protons from the incident solar wind beam. The cross‐shock potential calculated here is consistent with previous estimations based on particle measurements and numerical/analytical simulations. The ambipolar contribution to the cross‐shock potential calculated from the four‐spacecraft divergence of the electron pressure tensor is somewhat higher than that inferred form the Liouville‐mapped electron energy gain across the shock. Furthermore, the high‐time‐resolution 3‐D electric field measurements reported here reveal small‐scale nonlinear structures embedded in the shock layer that contribute to the nonmonotonic shock transition.
Connecting Direct Effects of CO2 Radiative Forcing to Ocean Heat Uptake and Circulation
Authors: Menzel Molly E. , Merlis Timothy M.
Published: June 2019

The ocean's response to direct atmospheric effects of increased carbon dioxide's (CO2) radiative forcing is examined. These direct effects are defined as the climate changes that result from forcing on a fast time scale of about a year, independent of the slower surface warming that the forcing also provokes. To evaluate how these direct effects impact ocean heat uptake and circulation, output of atmospheric general circulation model (GCM) simulations are used to force an ocean GCM with comprehensive boundary conditions. Perturbation simulations with the prescribed response to a quadrupling of atmospheric CO2 include altered surface winds, freshwater fluxes, downwelling shortwave radiation, and downwelling longwave cloud radiative effect. The perturbation simulations show that the intensification and poleward shift of surface winds, particularly in the Southern Ocean, strengthen the shallow overturning circulation in the tropical Pacific and deep overturning in the Atlantic. This, in turn, has a cooling effect on the global ocean at shallow depths. A two‐layer energy balance model, designed to capture transient global mean climate change, is adapted to account for the altered ocean heat uptake from direct effects. The direct change in global mean ocean heat uptake is a decrease of about 0.3 W/m2 for quadrupling of CO2, offsetting about 5% of the surface longwave forcing.
Ancient Water Underlies Arid Egypt
Authors: Morton Mary
Published: June 2019

A hidden trove of groundwater is left over from the last ice age.
Spatial Scales and Plasma Properties of the Distant Magnetopause: Evidence for Selective Ion and Electron Transport
Authors: Lukin A. S. , Artemyev A. V. , Petrukovich A. A. , Angelopoulos V. , Runov A. , Wang C.‐P. , Yushkov E. V.
Published: June 2019

One of the most important sources of magnetospheric plasma is particle entry through the distant magnetotail boundary, the nightside magnetopause. This entry mechanism depends on the magnetopause configuration. Off the equator, the strong lobe magnetic field renders the magnetopause a tangential or a rotational discontinuity, and thus the magnetosheath field orientation predominantly controls particle entry through magnetic reconnection. At the equatorial, distant tail magnetopause, however, the magnetic field's control of particle entry is diminished because the plasma beta there is large on both sides of the boundary. Thus, transport there can be significantly different from that at the dayside and off‐equatorial magnetopauses. Using observations from two Acceleration, Reconnection, Turbulence and Electrodynamics of the Moon's Interaction with the Sun probes, we investigate plasma transport mechanisms around the distant equatorial magnetopause. We find that transport occurs as a series of abrupt transitions in density, ion and electron temperatures, and ion kinetic energy of spatial scales as small as a typical plasma sheet ion gyroradius. Analysis of the particle phase space density reveals that an energy‐selection mechanism controls electron transport across the magnetopause, whereas ion transport is likely controlled by spatial diffusion driven by low‐frequency magnetic field fluctuations. We discuss the importance of these fluctuations for the magnetopause structure (e.g., the thickness of the transitions in plasma density, ion and electron temperatures, and ion kinetic energy).
Global 3‐D Simulations of the Triple Oxygen Isotope Signature Δ17O in Atmospheric CO2
Authors: Koren Gerbrand , Schneider Linda , van der Velde Ivar R. , van Schaik Erik , Gromov Sergey S. , Adnew Getachew A. , Mrozek Martino Dorota J. , Hofmann Magdalena E. G. , Liang Mao‐Chang , Mahata Sasadhar , Bergamaschi Peter , van der Laan‐Luijkx Ingrid T. , Krol Maarten C. , Röckmann Thomas , Peters Wouter
Published: June 2019

The triple oxygen isotope signature Δ17O in atmospheric CO2, also known as its “17O excess,” has been proposed as a tracer for gross primary production (the gross uptake of CO2 by vegetation through photosynthesis). We present the first global 3‐D model simulations for Δ17O in atmospheric CO2 together with a detailed model description and sensitivity analyses. In our 3‐D model framework we include the stratospheric source of Δ17O in CO2 and the surface sinks from vegetation, soils, ocean, biomass burning, and fossil fuel combustion. The effect of oxidation of atmospheric CO on Δ17O in CO2 is also included in our model. We estimate that the global mean Δ17O (defined as
with λRL = 0.5229) of CO2 in the lowest 500 m of the atmosphere is 39.6 per meg, which is ∼20 per meg lower than estimates from existing box models. We compare our model results with a measured stratospheric Δ17O in CO2 profile from Sodankylä (Finland), which shows good agreement. In addition, we compare our model results with tropospheric measurements of Δ17O in CO2 from Göttingen (Germany) and Taipei (Taiwan), which shows some agreement but we also find substantial discrepancies that are subsequently discussed. Finally, we show model results for Zotino (Russia), Mauna Loa (United States), Manaus (Brazil), and South Pole, which we propose as possible locations for future measurements of Δ17O in tropospheric CO2 that can help to further increase our understanding of the global budget of Δ17O in atmospheric CO2.
FBXO22 mediates polyubiquitination and inactivation of LKB1 to promote lung cancer cell growth
Authors: Zhu Xiao-Na , He Ping , Zhang Liang , Yang Shuo , Zhang Hui-Lin , Zhu Di , Liu Meng-Di , Yu Yun
Published: June 2019

Liver kinase B1 (LKB1) regulates both cell growth and energy metabolism. Inactivated mutations of LKB1, observed in 20–30% of nonsmall cell lung cancers (NSCLC), contribute significantly to lung cancer malignancy progression. However, the upstream signalings regulating LKB1 activity remain incompletely understood. Here, we present evidence that FBXO22 interacts with and promotes polyubiquitination of LKB1. More intriguingly, FBXO22 mediates Lys-63-linked LKB1 polyubiquitination and inhibits kinase activity of LKB1. Furthermore, over-expression of FBXO22 promotes NSCLC cell growth through inhibiting LKB1-AMPK-mTOR signaling in vitro and in vivo. Clinically, FBXO22 is highly expressed in human lung adenocarcinoma and high FBXO22 expression predicts significant poor prognosis. Our study provides new insights into the upstream regulation of LKB1 activation and identifies FBXO22 as a potential therapeutic target for lung cancer treatment.
Integrated NMR and cryo-EM atomic-resolution structure determination of a half-megadalton enzyme complex
Authors: Gauto Diego F. , Estrozi Leandro F. , Schwieters Charles D. , Effantin Gregory , Macek Pavel , Sounier Remy , Sivertsen Astrid C. , Schmidt Elena , Kerfah Rime , Mas Guillaume , Colletier Jacques-Philippe , Güntert Peter , Favier Adrien , Schoehn Guy , Schanda Paul , Boisbouvier Jerome
Published: June 2019

Atomic-resolution structure determination is crucial for understanding protein function. Cryo-EM and NMR spectroscopy both provide structural information, but currently cryo-EM does not routinely give access to atomic-level structural data, and, generally, NMR structure determination is restricted to small (<30 kDa) proteins. We introduce an integrated structure determination approach that simultaneously uses NMR and EM data to overcome the limits of each of these methods. The approach enables structure determination of the 468 kDa large dodecameric aminopeptidase TET2 to a precision and accuracy below 1 Å by combining secondary-structure information obtained from near-complete magic-angle-spinning NMR assignments of the 39 kDa-large subunits, distance restraints from backbone amides and ILV methyl groups, and a 4.1 Å resolution EM map. The resulting structure exceeds current standards of NMR and EM structure determination in terms of molecular weight and precision. Importantly, the approach is successful even in cases where only medium-resolution cryo-EM data are available.
SMPDL3b modulates insulin receptor signaling in diabetic kidney disease
Authors: Mitrofanova A. , Mallela S. K. , Ducasa G. M. , Yoo T. H. , Rosenfeld-Gur E. , Zelnik I. D. , Molina J. , Varona Santos J. , Ge M. , Sloan A. , Kim J. J. , Pedigo C. , Bryn J. , Volosenco I. , Faul C. , Zeidan Y. H. , Garcia Hernandez C. , Mendez A. J. , Leibiger I. , Burke G. W. , Futerman A. H. , Barisoni L. , Ishimoto Y. , Inagi R. , Merscher S. , Fornoni A.
Published: June 2019

Sphingomyelin phosphodiesterase acid-like 3b (SMPDL3b) is a lipid raft enzyme that regulates plasma membrane (PM) fluidity. Here we report that SMPDL3b excess, as observed in podocytes in diabetic kidney disease (DKD), impairs insulin receptor isoform B-dependent pro-survival insulin signaling by interfering with insulin receptor isoforms binding to caveolin-1 in the PM. SMPDL3b excess affects the production of active sphingolipids resulting in decreased ceramide-1-phosphate (C1P) content as observed in human podocytes in vitro and in kidney cortexes of diabetic db/db mice in vivo. Podocyte-specific Smpdl3b deficiency in db/db mice is sufficient to restore kidney cortex C1P content and to protect from DKD. Exogenous administration of C1P restores IR signaling in vitro and prevents established DKD progression in vivo. Taken together, we identify SMPDL3b as a modulator of insulin signaling and demonstrate that supplementation with exogenous C1P may represent a lipid therapeutic strategy to treat diabetic complications such as DKD.
Publisher Correction: Contemporaneous 3D characterization of acute and chronic myocardial I/R injury and response
Authors: Merz Simon F. , Korste Sebastian , Bornemann Lea , Michel Lars , Stock Pia , Squire Anthony , Soun Camille , Engel Daniel R. , Detzer Julia , Lörchner Holger , Hermann Dirk M. , Kamler Markus , Klode Joachim , Hendgen-Cotta Ulrike B. , Rassaf Tienush , Gunzer Matthias , Totzeck Matthias
Published: June 2019

An amendment to this paper has been published and can be accessed via a link at the top of the paper.
Changes in Plant Rhizosphere Microbial Communities under Different Vegetation Restoration Patterns in Karst and Non-karst Ecosystems
Authors: Fan Zhouzhou , Lu Shuyu , Liu Shuang , Guo Hui , Wang Tao , Zhou Jinxing , Peng Xiawei
Published: June 2019

Understanding how patterns of recovery and geological conditions affect microbial communities is important for determining the stability of karst ecosystems. Here, we investigated the diversity and composition of microorganisms in karst and non-karst environments under natural restoration and artificial rehabilitation conditions. The results showed no significant differences in soil microbial diversity, but the microbial communities associated with geological conditions and tree species differed significantly. Variation partitioning analysis (VPA) showed that a total of 77.3% of the variation in bacteria and a total of 69.3% of the variation in fungi could be explained by vegetation type and geological background. There were significant differences in six bacterial classes (Actinobacteria, Alphaproteobacteria, Ktedonobacteria, TK10, Gammaproteobacteria, and Anaerolineae) and nine fungal classes (Eurotiomycetes, Agaricomycetes, unclassified _p_Ascomycota, Sordariomycetes, Tremellomycetes, norank_k_Fungi, Pezizomycetes, Leotiomycetes and Archaeorhizomycetes) among the soils collected from six plots. A Spearman correlation heatmap showed that the microbial community was affected by the major soil properties. Principal coordinates analysis indicated that the microbial community of Pinus yunnanensis in the artificial forest, which was established for the protection of the environment was most similar to that in the natural secondary forest in the karst ecosystem. These findings further our understanding of microbial responses to vegetation restoration and geological conditions.
A lattice model to manage the vector and the infection of the Xylella fastidiosa on olive trees
Authors: Fierro Annalisa , Liccardo Antonella , Porcelli Francesco
Published: June 2019

Since October 2013 a new devastating plant disease, known as Olive Quick Decline Syndrome, has been killing most of the olive trees distributed in Apulia, South Italy. Xylella fastidiosa pauca ST53 is the plant pathogenic bacterium responsible for the disease, and the adult Meadow Spittlebug, Philaenus spumarius (L.) (Hemiptera Aphrophoridae), is its main vector. This study proposes a lattice model for the pathogen invasion of olive orchard aimed at identifying an appropriate strategy for arresting the infection, built on the management of the vector throughout its entire life cycle. In our model the olive orchard is depicted as a simple square lattice with olive trees and herbaceous vegetation distributed on the lattice sites in order to mimic the typical structure of an olive orchard; adult vectors are represented by particles moving on the lattice according to rules dictated by the interplay between vector and vegetation life cycles or phenology; the transmission process of the bacterium is regulated by a stochastic Susceptible, Infected and Removed model. On this baseline model, we build-up a proper Integrated Pest Management strategy based on tailoring, timing, and tuning of available control actions. We demonstrate that it is possible to reverse the hitherto unstoppable Xylella fastidiosa pauca ST53 invasion, by a rational vector and transmission control strategy.
First description of bacterial and fungal communities in Colombian coffee beans fermentation analysed using Illumina-based amplicon sequencing
Authors: de Oliveira Junqueira Ana C. , de Melo Pereira Gilberto V. , Coral Medina Jesus D. , Alvear María C. R. , Rosero Rubens , de Carvalho Neto Dão P. , Enríquez Hugo G. , Soccol Carlos R.
Published: June 2019

In Colombia, coffee growers use a traditional method of fermentation to remove the cherry pulp surrounding the beans. This process has a great influence on sensory quality and prestige of Colombian coffee in international markets, but has never been studied. Here we use an Illumina-based amplicon sequencing to investigate bacterial and fungal communities associated with spontaneous coffee-bean fermentation in Colombia. Microbial-derived metabolites were further analysed by high–performance liquid chromatography and gas chromatography–mass spectrometry. Highly diverse bacterial groups, comprising 160 genera belonging to 10 phyla, were found. Lactic acid bacteria (LAB), mainly represented by the genera Leuconostoc and Lactobacillus, showed relative prevalence over 60% at all sampling times. The structure of the fungal community was more homogeneous, with Pichia nakasei dominating throughout the fermentation process. Lactic acid and acetaldehyde were the major end-metabolites produced by LAB and Pichia, respectively. In addition, 20 volatile compounds were produced, comprising alcohols, organic acids, aldehydes, esters, terpenes, phenols, and hydrocarbons. Interestingly, 56 microbial genera, associated with native soil, seawater, plants, insects, and human contact, were detected for the first time in coffee fermentation. These microbial groups harbour a remarkable phenotypic diversity and may impart flavours that yield clues to the terroir of Colombian coffees.
Development of CS-TPP-dsRNA nanoparticles to enhance RNAi efficiency in the yellow fever mosquito, Aedes aegypti
Authors: Dhandapani Ramesh Kumar , Gurusamy Dhandapani , Howell Jeffrey L. , Palli Subba Reddy
Published: June 2019

Mosquito-borne diseases are a major threat to human health and are responsible for millions of deaths globally each year. Vector control is one of the most important approaches used in reducing the incidence of these diseases. However, increasing mosquito resistance to chemical insecticides presents challenges to this approach. Therefore, new strategies are necessary to develop the next generation vector control methods. Because of the target specificity of dsRNA, RNAi-based control measures are an attractive alternative to current insecticides used to control disease vectors. In this study, Chitosan (CS) was cross-linked to sodium tripolyphosphate (TPP) to produce nano-sized polyelectrolyte complexes with dsRNA. CS-TPP-dsRNA nanoparticles were prepared by ionic gelation method. The encapsulation efficiency, protection of dsRNA from nucleases, cellular uptake, in vivo biodistribution, larval mortality and gene knockdown efficiency of CS-TPP-dsRNA nanoparticles were determined. The results showed that at a 5:1 weight ratio of CS-TPP to dsRNA, nanoparticles of less than 200 nm mean diameter and a positive surface charge were formed. Confocal microscopy revealed the distribution of the fed CS-TPP-dsRNA nanoparticles in midgut, fat body and epidermis of yellow fever mosquito, Aedes aegypti larvae. Bioassays showed significant mortality of larvae fed on CS-TPP-dsRNA nanoparticles. These assays also showed knockdown of a target gene in CS-TPP-dsRNA nanoparticle fed larvae. These data suggest that CS-TPP nanoparticles may be used for delivery of dsRNA to mosquito larvae.
Heavy oxygen recycled into the lithospheric mantle
Authors: Dallai Luigi , Bianchini Gianluca , Avanzinelli Riccardo , Natali Claudio , Conticelli Sandro
Published: June 2019

Magmas in volcanic arcs have geochemical and isotopic signatures that can be related to mantle metasomatism due to fluids and melts released by the down-going oceanic crust and overlying sediments, which modify the chemistry and mineralogy of the mantle wedge. However, the effectiveness of subduction-related metasomatic processes is difficult to evaluate because the composition of arc magmas is often overprinted by interactions with crustal lithologies occurring during magma ascent and emplacement. Here, we show unequivocal evidence for recycling of continental crust components into the mantle. Veined peridotite xenoliths sampled from Tallante monogenetic volcanoes in the Betic Cordillera (southern Spain) provide insights for mantle domains that reacted with Si-rich melts derived by partial melting of subducted crustal material. Felsic veins crosscutting peridotite and the surrounding orthopyroxene-rich metasomatic aureoles show the highest 18O/16O ratios measured to date in upper mantle assemblages worldwide. The anomalously high oxygen isotope compositions, coupled with very high 87Sr/86Sr values, imply the continental crust origin of the injected melts. Isotopic anomalies are progressively attenuated in peridotite away from the veins, showing 18O isotope variations well correlated with the amount of newly formed orthopyroxene. Diffusion may also affect the isotope ratios of mantle rocks undergoing crustal metasomatism due to the relaxation of 18O isotope anomalies to normal mantle values through time. Overall, the data define an O isotope “benchmark” allowing discrimination between mantle sources that attained re-equilibration after metasomatism (>5 Myr) and those affected by more recent subduction-derived enrichment processes.
Differential wing polyphenism adaptation across life stages under extreme high temperatures in corn leaf aphid
Authors: Chen Yu , Verheggen François J. , Sun Dandan , Wang Zhenying , Francis Frederic , He KangLai
Published: June 2019

Polyphenism, a common phenomenon in nature, is an important form of adaptation in a diverse environment. Corn leaf aphid (CLA), Rhopalosiphum maidis, (Hemiptera: Aphididae), exhibit wing polyphenism in response to poor habitat quality. In this study, we focused on the effects of crowding and thermal cues on morph determination of CLA. Five developmental stages of aphids (1st to 4th nymphs and maternal adults) with increased population densities, were tested under two kinds of temperature patterns, i.e., A) a constant temperature of 22 °C with 2 h exposure to high temperature in the range of 35 to 39 °C during mid-photophase and B) different constant temperatures in the range of 22–30 °C with 2 h exposure to high temperature of 39 °C during mid-photophase. Crowding was found to directly impact winged induction. The 1st and 2nd nymphs were more sensitive for alate morphs induction under high density. In addition, temperature played a significant role in wing production, with the temperature setting of 26/39 °C in pattern B inducing higher alate morphs and survival than other temperature settings. Therefore, we hypothesize that warmer climate with brief high temperature is more favourable for survival and alate morphs production, but cool weather and transient extreme high temperature (>39 °C) is detrimental for CLA. Our results provide a new perspective on understanding the interactions between changes in extreme high temperatures and insect densities that differentially affect wing polymorphism for further demographic and distribution rates of species across temporal and spatial scales.
The spatial parameters of gait and their association with falls, functional decline and death in older adults: a prospective study
Authors: Rodríguez-Molinero Alejandro , Herrero-Larrea Alexandra , Miñarro Antonio , Narvaiza Leire , Gálvez-Barrón César , Gonzalo León Natalia , Valldosera Esther , de Mingo Eva , Macho Oscar , Aivar David , Pinzón Efren , Alba Adilis , Passarelli Jorge , Stasi Nadia , Valverde Rosa Ana , Kruse Liane , Felipe Elisabet , Collado Isabel , Sabater Joan Bosch
Published: June 2019

Association between spatial gait parameters and adverse health outcomes in the elderly has not been sufficiently studied. The goal of this study is to evaluate whether the stride length or the step width predict falls, functional loss and mortality. We conducted a prospective cohort study on a probabilistic sample of 431 noninstitutionalized, older-than-64-years subjects living in Spain, who were followed-up for five years. In the baseline visit, spatial gait parameters were recorded along with several control variables, with special emphasis on known medical conditions, strength, balance and functional and cognitive capacities. In the follow-up calls, vital status, functional status and number of falls from last control were recorded. We found that a normalized-to-height stride length shorter than 0.52 predicted recurrent falls in the next 6 months with 93% sensitivity and 53% specificity (AUC: 0.72), and in the next 12 months with 81% sensitivity and 57% specificity (AUC: 0.67). A normalized stride length <0.5 predicted functional loss at 12 months with a sensitivity of 79.4% and specificity of 65.6% (AUC: 0.75). This predictive capacity remained independent after correcting for the rest of risk factors studied. Step-with was not clearly related to functional loss or falls. Both shorter normalized stride length (OR1.56; AUC: 0.62; p < 0.05) and larger step width (OR1.42; AUC: 0.62; p < 0.05) were associated with risk of death at 60 months; however, none of them remained as independent predictor of death, after correcting for other risk factors. In summary, spatial gait parameters may be risk markers for adverse outcomes in the elderly. Step length is independently associated with functional loss and falls at one year, after correction for numerous known risk factors.
Liver sinusoidal endothelial cells (LSECs) modifications in patients with chronic hepatitis C
Authors: Baiocchini Andrea , Del Nonno Franca , Taibi Chiara , Visco-Comandini Ubaldo , D’Offizi Gianpiero , Piacentini Mauro , Falasca Laura
Published: June 2019

The sinusoidal endothelial cells present in the liver (LSECs) are tipically characterized by the presence of pores (fenestrae). During some pathological conditions LSECs undergo “capillarization”, a process characterized by loss of fenestrations and acquisition of a vascular phenotype. In chronic liver disease capillarization has been reported to precede the development of fibrosis. LSECs modification in the setting of HCV infection is currently poorly investigated. Considering that HCV accounts for important changes in hepatocytes and in view of the intimate connection between hepatocytes and LSECs, here we set out to study in great detail the LSECs modifications in individuals with HCV-dependent chronic hepatitis. Electron microscopy analysis, and evaluation of CD32, CD31 and caveolin-1 expression showed that in HCV infection LSECs display major morphological changes but maintain their phenotypical identity. Capillarization was observed only in cases at initial stages of fibrosis. Our findings showed that the severity of LSECs modifications appears to be correlated with hepatocytes damage and fibrosis stage providing novel insight in the pathogenesis of HCV-chronic hepatitis.
Early corneal nerve fibre damage and increased Langerhans cell density in children with type 1 diabetes mellitus
Authors: Ferdousi Maryam , Romanchuk Kenneth , Mah Jean K. , Virtanen Heidi , Millar Christine , Malik Rayaz A. , Pacaud Danièle
Published: June 2019

Corneal confocal microscopy (CCM) has been used to identify corneal nerve damage and increased Langerhans cell (LC) density in adults with Type 1 diabetes mellitus (T1DM). The purpose of this study was to evaluate whether corneal confocal microscopy can identify early corneal nerve damage and change in LC density in children and adolescents with T1DM. 64 participants with T1DM (age-14.6 ± 2.5 years, duration of diabetes-9.1 ± 2.7 years, HbA1c-75.66 ± 2.53 mmol/mol [9.1 ± 1.8%]) and 48 age-matched healthy control subjects underwent CCM. Sub-basal corneal nerve morphology and the density of mature and immature LCs was quantified. Corneal nerve fibre length and branch density were lower, whilst fibre density and tortuosity did not differ and both immature and mature LC density was significantly higher in T1DM compared to control subjects. There was no association between HbA1c and duration of diabetes with nerve fibre parameters or LC’s density. Children and adolescents with T1DM demonstrate early immune activation and nerve degeneration.
The ketogenic diet in children 3 years of age or younger: a 10-year single-center experience
Authors: Kim Se Hee , Shaw Alexandra , Blackford Robyn , Lowman Wesley , Laux Linda C. , Millichap John J. , Nordli Douglas R.
Published: June 2019

The ketogenic diet (KD) is an effective treatment option for intractable epilepsy. Here, we reviewed the last 10 years of our experience with the KD and characterized its use in patients under 3 years of age. Medical records of all patients under the age of 3 years who were treated with the ketogenic diet from April 2004 to June 2014 were retrospectively reviewed. One hundred and nine patients with drug-resistant epilepsy were included. The mean age at the initiation of the KD was 1.4 ± 0.8 years old. The youngest patient was 3 weeks old. After 3 months, 39% (42/109) of patients responded to the KD and experienced more than 50% seizure reduction. Of those 42 patients, 20 (18%) achieved complete seizure control. Patients with a genetic etiology showed a better response to the KD in seizure reduction than the other patients (p = 0.03). Age at initiation of the KD was not related to eventual seizure outcome (p = 0.6). The KD continues to be an effective, safe, and well tolerated treatment option for infants with intractable epilepsy.
Optical Signatures Derived From Deep UV to NIR Excitation Discriminates Healthy Samples From Low and High Grades Glioma
Authors: Mehidine Hussein , Chalumeau Audrey , Poulon Fanny , Jamme Frédéric , Varlet Pascale , Devaux Bertrand , Refregiers Matthieu , Abi Haidar Darine
Published: June 2019

Among all the tumors of the central nervous system (CNS), glioma are the most deadly and the most malignant. Surgical resection is the standard therapeutic method to treat this type of brain cancer. But the diffusive character of these tumors create many problems for surgeons during the operation. In fact, these tumors migrate outside the tumor solid zone and invade the surrounding healthy tissues. These infiltrative tissues have the same visual appearance as healthy tissues, making it very difficult for surgeons to distinguish the healthy ones from the diffused ones. The surgeon, therefore, cannot properly remove the tumor margins increasing the recurrence risk of the tumor. To resolve this problem, our team has developed a multimodal two-photon fibered endomicroscope, compatible with the surgeon trocar, to better delimitate tumor boundaries by relying on the endogenous fluorescence of brain tissues. In this context, and in order to characterize the optical signature of glioma tumors, this study offers multimodal and multi-scaled optical measurements from healthy tissues to high grade glioma. We can interrogate tissue from deep ultra-violet to near infrared excitation by working with spectroscopy, fluorescence lifetime imaging, two-photon fluorescene imaging and Second Harmonic Generation (SHG) imaging. Optically derived ratios such as the Tryptophan/Collagen ratio, the optical redox ratio and the long lifetime intensity fraction, discriminated diseased tissue from its normal counterparts when fitted by Gaussian ellipsoids and choosing a threshold for each. Additionally two-photon fluorescence and SHG images were shown to display similar histological features as Hematoxylin-Eosin stained images.
Replication fork rescue in mammalian mitochondria
Authors: Torregrosa-Muñumer Rubén , Hangas Anu , Goffart Steffi , Blei Daniel , Zsurka Gábor , Griffith Jack , Kunz Wolfram S. , Pohjoismäki Jaakko L. O.
Published: June 2019

Replication stalling has been associated with the formation of pathological mitochondrial DNA (mtDNA) rearrangements. Yet, almost nothing is known about the fate of stalled replication intermediates in mitochondria. We show here that replication stalling in mitochondria leads to replication fork regression and mtDNA double-strand breaks. The resulting mtDNA fragments are normally degraded by a mechanism involving the mitochondrial exonuclease MGME1, and the loss of this enzyme results in accumulation of linear and recombining mtDNA species. Additionally, replication stress promotes the initiation of alternative replication origins as an apparent means of rescue by fork convergence. Besides demonstrating an interplay between two major mechanisms rescuing stalled replication forks – mtDNA degradation and homology-dependent repair – our data provide evidence that mitochondria employ similar mechanisms to cope with replication stress as known from other genetic systems.
Studies of Black Diamond as an antibacterial surface for Gram Negative bacteria: the interplay between chemical and mechanical bactericidal activity
Authors: Dunseath O. , Smith E. J. W. , Al-Jeda T. , Smith J. A. , King S. , May P. W. , Nobbs A. H. , Hazell G. , Welch C. C. , Su B.
Published: June 2019

‘Black silicon’ (bSi) samples with surfaces covered in nanoneedles of length ~5 µm were fabricated using a plasma etching process and then coated with a conformal uniform layer of diamond using hot filament chemical vapour deposition to produce ‘black diamond’ (bD) nanostructures. The diamond needles were then chemically terminated with H, O, NH2 or F using plasma treatment, and the hydrophilicity of the resulting surfaces were assessed using water droplet contact-angle measurements, and scaled in the order O > H ≈NH2 >F, with the F-terminated surface being superhydrophobic. The effectiveness of these differently terminated bD needles in killing the Gram-negative bacterium E. coli was semi-quantified by Live/Dead staining and fluorescence microscopy, and visualised by environmental scanning electron microscopy. The total number of adhered bacteria was consistent for all the nanostructured bD surfaces at around 50% of the value for the flat diamond control. This, combined with a chemical bactericidal effect of 20–30%, shows that the nanostructured bD surfaces supported significantly fewer viable E. coli than flat surfaces. Moreover, the bD surfaces were particularly effective at preventing the establishment of bacterial aggregates – a precursor to biofilm formation. The percentage of dead bacteria also decreased as a function of hydrophilicity. These results are consistent with a predominantly mechanical mechanism for bacteria death based on the stretching and disruption of the cell membrane, combined with an additional effect from the chemical nature of the surface.
Hepatic tumor classification using texture and topology analysis of non-contrast-enhanced three-dimensional T1-weighted MR images with a radiomics approach
Authors: Oyama Asuka , Hiraoka Yasuaki , Obayashi Ippei , Saikawa Yusuke , Furui Shigeru , Shiraishi Kenshiro , Kumagai Shinobu , Hayashi Tatsuya , Kotoku Jun’ichi
Published: June 2019

The purpose of this study is to evaluate the accuracy for classification of hepatic tumors by characterization of T1-weighted magnetic resonance (MR) images using two radiomics approaches with machine learning models: texture analysis and topological data analysis using persistent homology. This study assessed non-contrast-enhanced fat-suppressed three-dimensional (3D) T1-weighted images of 150 hepatic tumors. The lesions included 50 hepatocellular carcinomas (HCCs), 50 metastatic tumors (MTs), and 50 hepatic hemangiomas (HHs) found respectively in 37, 23, and 33 patients. For classification, texture features were calculated, and also persistence images of three types (degree 0, degree 1 and degree 2) were obtained for each lesion from the 3D MR imaging data. We used three classification models. In the classification of HCC and MT (resp. HCC and HH, HH and MT), we obtained accuracy of 92% (resp. 90%, 73%) by texture analysis, and the highest accuracy of 85% (resp. 84%, 74%) when degree 1 (resp. degree 1, degree 2) persistence images were used. Our methods using texture analysis or topological data analysis allow for classification of the three hepatic tumors with considerable accuracy, and thus might be useful when applied for computer-aided diagnosis with MR images.
Merensky-type platinum deposits and a reappraisal of magma chamber paradigms
Authors: Chistyakova Sofya , Latypov Rais , Hunt Emma J. , Barnes Stephen
Published: June 2019

Most of the world’s economically-viable platinum deposits occur as ‘reefs’ in layered intrusions – thin layers of silicate rocks that contain sulphides enriched in noble metals. There are two contrasting magmatic hypotheses for their formation. The first suggests accumulation through gravity-induced settling of crystals onto the magma chamber floor. The alternative argues for in situ crystallization, i.e. upward growth from the floor. Here we report on our discovery of the Merensky Reef in the Bushveld Complex that occurs on subvertical to overturned margins of depressions in a temporary chamber floor. Such relationships preclude crystal settling and demonstrate that the reef crystallized in situ. This finding indicates that platinum deposits can grow directly at the chamber floor, with immiscible sulfide droplets sequestering ore-forming noble metals from strongly convecting silicate magmas. Our model also provides evidence for the paradigm that argues for magma chambers being masses of nearly crystal-free melt, which gradually loses heat and crystallizes from the margins inward.
RETRACTED ARTICLE: Amelioration of obsessive-compulsive disorder in three mouse models treated with one epigenetic drug: unraveling the underlying mechanism
Authors: Todorov German , Mayilvahanan Karthikeyan , Ashurov David , Cunha Catarina
Published: June 2019

Mental health disorders are manifested in families, yet cannot be fully explained by classical Mendelian genetics. Changes in gene expression via epigenetics present a plausible mechanism. Anxiety often leads to avoidant behaviors which upon repetition may become habitual, maladaptive and resistant to extinction as observed in obsessive compulsive disorders (OCD). Psychophysical models of OCD propose that anxiety (amygdala) and habits (dorsolateral striatum, DLS) may be causally linked. The amygdala activates spiny projection neurons in the DLS. Repetitive amygdala terminal stimulation in the DLS elicits long term OCD-like behavior in mice associated with circuitry changes and gene methylation-mediated decrease in the activity of protein phosphatase 1 (PP1). Treatment of OCD-like grooming behavior in Slitrk5, SAPAP3, and laser-stimulated mice with one dose of RG108 (DNA methyltransferase inhibitor), lead to marked symptom improvement lasting for at least one week as well as complete reversal of anomalous changes in circuitry and PP1 gene methylation.