bluuebunny/crossref_metadata_2025 huggingface dataset:
The NMDA Receptor Subunit (GluN1 and GluN2A) Modulation Following Different Conditions of Cocaine Abstinence in Rat Brain Structures
Authors: Smaga Irena , Wydra Karolina , Suder Agata , Frankowska Małgorzata , Sanak Marek , Caffino Lucia , Fumagalli Fabio , Filip Małgorzata
Published: March 2021

Different neuronal alterations within glutamatergic system seem to be crucial for developing of cocaine-seeking behavior. Cocaine exposure provokes a modulation of the NMDA receptor subunit expression in rodents, which probably contributes to cocaine-induced behavioral alterations. The aim of this study was to examine the composition of the NMDA receptor subunits in the brain structures in rats with the history of cocaine self-administration after cocaine abstinence (i) in an enriched environment, (ii) in an isolated condition, (iii) with extinction training, or (iv) without instrumental task, as well as the Grin1 (encoding GluN1) and Grin2A (encoding GluN2A) gene expression were evaluated after 10-day extinction training in rat brain structures. In the present study, we observed changes only following cocaine abstinence with extinction training, when the increased GluN2A subunit levels were seen in the postsynaptic density fraction but not in the whole homogenate of the prelimbic cortex (PLC) and dorsal hippocampus (dHIP) in rats previously self-administered cocaine. At the same time, extinction training did not change the Grin1 and Grin2A gene expression in these structures. In conclusion, NMDA receptor subunit modulation observed following cocaine abstinence with extinction training may represent a potential target in cocaine-seeking behavior.
Revisiting Hans Böker’s "Species Transformation Through Reconstruction: Reconstruction Through Active Reaction of Organisms" (1935)
Authors: Fábregas-Tejeda Alejandro , Nieves Delgado Abigail , Baedke Jan
Published: March 2021

Against the common historiographic narratives of evolutionary biology, the first decades of the 20th century were theoretically far richer than usually assumed. This especially refers to the hitherto neglected role that early theoretical biologists played in introducing visionary research perspectives and concepts before the institutionalization of the Modern Synthesis. Here, we present one of these scholars, the German theoretical biologist and ecomorphologist Hans Böker (1886–1939), by reviewing his 1935 paper “Artumwandlung durch Umkonstruktion, Umkonstruktion durch aktives Reagieren der Organismen” ("Species Transformation Through Reconstruction: Reconstruction Through Active Reaction of Organisms"), published in the inaugural volume of the journal Acta Biotheoretica. While largely forgotten today, this work represents a melting pot of ideas that adumbrate some of today’s most lively debated empirical and conceptual topics in evolutionary biology: the active role of organisms as actors of their own evolution, environmental induction and phenotypic plasticity, genetic assimilation, as well as developmental bias. We discuss Böker’s views on how species change through (what he calls) "Umkonstruktion," and how such reconstruction is exerted through active reactions of organisms to environmental perturbations. In addition, we outline the aims and wider context of his "biological comparative anatomy," including Boker’s reprehensible political affiliation with the Nazi Party. Finally, we highlight some of the historical reasons for why Böker’s views did not have a larger impact in evolutionary biology, but we also recount some of the direct and indirect legacies of his approach in research areas such as ecomorphology and (Eco)EvoDevo. Böker’s paper is available as supplementary material in the online version of this article, as part of the journal's "Classics in Biological Theory" collection; the first translation of the paper into English, by Alexander Böhm and Jan Baedke, is also being published in this volume.
Dynamics of lubricated spiral bevel gears under different contact paths
Authors: Cao Wei , He Tao , Pu Wei , Xiao Ke
Published: March 2021

To assess the meshing quality of spiral bevel gears, the static meshing characteristics are usually checked under different contact paths to simulate the deviation in the footprint from the design point to the heel or toe of the gear flank caused by the assembly error of two gear axes. However, the effect of the contact path on gear dynamics under lubricated conditions has not been reported. In addition, most studies regarding spiral bevel gears disregard the lubricated condition because of the complicated solutions of mixed elastohydrodynamic lubrication (EHL). Hence, an analytical friction model with a highly efficient solution, whose friction coefficient and film thickness predictions agree well with the results from a well-validated mixed EHL model for spiral bevel gears, is established in the present study to facilitate the study of the dynamics of lubricated spiral bevel gears. The obtained results reveal the significant effect of the contact path on the dynamic response and meshing efficiency of gear systems. Finally, a comparison of the numerical transmission efficiency under different contact paths with experimental measurements indicates good agreement.
On-line hemodiafiltration modulates atherosclerosis signaling in peripheral lymphomonocytes of hemodialysis patients
Authors: Simone Simona , Chieti Annarita , Pontrelli Paola , Rascio Federica , Castellano Giuseppe , Stallone Giovanni , Infante Barbara , Gesualdo Loreto , Grandaliano Giuseppe , Pertosa Giovanni
Published: March 2021

Background

Hemodialysis patients present a dramatic increase in cardiovascular morbidity/mortality. Circulating immune cells, activated by both uremic milieu and dialysis, play a key role in the pathogenesis of dialysis-related vascular disease. The aim of our study was to identify, through a high-throughput approach, differences in gene expression profiles in the peripheral blood mononuclear cells (PBMCs) of patients treated with on-line hemodiafiltration and bicarbonate hemodialysis.

Methods

The transcriptomic profile was investigated in PBMCs isolated from eight patients on on-line hemodiafiltration and eight patients on bicarbonate hemodialysis by microarray analysis. The results were evaluated by statistical and functional pathway analysis and validated by real time PCR (qPCR) in an independent cohort of patients (on-line hemodiafiltration N = 20, bicarbonate hemodialysis n = 20).

Results

Eight hundred and forty-seven genes were differentially expressed in patients treated with  on-line hemodiafiltration and bicarbonate hemodialysis. Thirty-seven functional gene networks were identified and atherosclerosis signaling was the top canonical pathway regulated by on-line hemodiafiltration. Among the genes of this pathway, on-line hemodiafiltration was associated with a reduced expression of Platelet-derived growth factor A chain (PDGF A), Clusterin, Monoamine Oxidase A, Interleukin-6 (IL-6) and Vascular Endothelial Growth
Factor C (VEGF-)C and with an increase of Apolipoprotein E. qPCR confirmed the microarray results. Platelet derived growth factor AA (PDGF-AA), IL-6 and VEGF-C serum levels were significantly lower in the on-line hemodiafiltration group. Finally, 10 patients previously on bicarbonate hemodialysis  were switched to on-line hemodiafiltration and PBMCs were harvested after 6 months. The qPCR results from this perspective group confirmed the modulation of atherosclerotic genes observed in the cross-sectional analysis.

Conclusions

Our data suggest that type of dialysis (on-line hemodiafiltration versus bicarbonate hemodialysis) may modulate the expression of several genes involved in the pathogenesis of atherosclerotic disease.
The Core Requirements of the International Rule of Law in the Practice of States
Authors: Arajärvi Noora
Published: March 2021

Is it possible to identify some foundational elements of international law that can be generally accepted by all States? Can such core elements reach a normative threshold to be considered requirements rather than “values” or “virtues” ? And finally, what are these core requirements of the international rule of law? This contribution propositions that, indeed, such core elements exist, identifies them—non-arbitrariness, consistency and predictability—from the practice of States at the international level and conceptualises them as the minimum requirements of the international rule of law. It presents an empirical study of statements of governments at the United Nations (UN) during a five-year period (2012–2017), accompanying the relevant findings with references to decisions and opinions of the International Court of Justice (ICJ).
Effect of chemical and sanitary intervention on rat sightings in urban communities of New Providence, the Bahamas
Authors: Awoniyi Adedayo M. , Thompson Andrew , Ferguson Luther , Mckenzie Melony , Souza Fabio N. , Zeppelini Caio G. , Costa Federico
Published: March 2021

Rats are invasive pest species that commonly infest low-income urban environments. Their association with humans constitutes a threat of rodent-borne disease transmission. We evaluated the outcome of a chemical and sanitary intervention on rat sightings in seven low-income urban settlements of New Providence, the Bahamas. The intervention consisted of rodenticide application, education about environmental sanitation, and improvement in waste disposal. Rat sightings were systematically recorded by trained staff before and three months after the intervention. The intervention slightly decreased rat sightings, with an average of 2.7-fold with varied effectiveness across locations. Four out of seven locations (57%) registered a decrease in rat sightings. Our results suggest that social and environmental differences among communities may be responsible for the mixed efficacy observed in the current rodent management practice in urban communities of the Bahamas. However, a new set of control measures needs to be developed for areas where rodent decline was not observed. This study provides novel data on how rat population behaves post-intervention in a unique ecological setting like the Bahamas, presenting an informed judgment for their management, especially in the event of a natural disaster.
Effectiveness of Dietary Interventions in the Treatment of Endometriosis: a Systematic Review
Authors: Nirgianakis Konstantinos , Egger Katharina , Kalaitzopoulos Dimitrios R. , Lanz Susanne , Bally Lia , Mueller Michael D.
Published: March 2021

A patients’ increasing interest in dietary modifications as a possible complementary or alternative treatment of endometriosis is observed. Unfortunately, the therapeutic potential of dietary interventions is unclear and to date no guidelines to assist physicians on this topic exist. The aim of this study, therefore, was to systematically review the existing studies on the effect of dietary interventions on endometriosis. An electronic-based search was performed in MEDLINE and COCHRANE. We included human and animal studies that evaluated a dietary intervention on endometriosis-associated symptoms or other health outcomes. Studies were identified and coded using standard criteria, and the risk of bias was assessed with established tools relevant to the study design. We identified nine human and 12 animal studies. Out of the nine human studies, two were randomized controlled trials, two controlled studies, four uncontrolled before-after studies, and one qualitative study. All of them assessed a different dietary intervention, which could be classified in one of the following principle models: supplementation with selected dietary components, exclusion of selected dietary components, and complete diet modification. Most of the studies reported a positive effect on endometriosis; they were however characterized by moderate or high-risk bias possibly due to the challenges of conducting dietary intervention trials. According to the available level of evidence, we suggest an evidence-based clinical approach for physicians to use during consultations with their patients. Further well-designed randomized controlled trials are needed to accurately determine the short-term and long-term effectiveness and safety of different dietary interventions.
The General Theory of Relativity
Authors: Rahaman Farook
Published: March 2021

The book aims to expound the general theory of relativity with a mathematical point of view. Catering to the needs of postgraduate students and researchers in the field of astrophysics and mathematical physics, it offers the readers a comprehensive understanding of the advanced topics of the subject matter. It specifically discusses the mathematical foundation of tensor calculus, gives a background of geodesics, Einstein's field equations, linearised gravity, spacetime of spherically symmetric distribution of matter and black holes, and particle and photon orbits in spacetime. Apart from the formulation of general relativity, Lie derivatives and its applications, and causality of spacetime are also discussed in detail. Certain preliminary concepts of extrinsic curvature, Lagrangian formalism of general theory of relativity and 3 + 1 decomposition of space-time are covered and are provided in the book as appendices.
Britain and the German Churches, 1945–1950
Authors: Howson Peter
Published: March 2021

Explores the ways in which the British Religious Affairs Branch aimed to organise religious life in post-war Germany.
The Household Knights of Edward III
Authors: Hefferan Matthew
Published: March 2021

First extended survey of the subject, looking at the knights' activities, roles, background and service.
Compounding Effects of Social Vulnerability and Recurring Natural Disasters on Mental and Physical Health
Authors: Hahn Micah B. , Van Wyck Rebecca , Lessard Lauren , Fried Ruby
Published: March 2021

Objective:

This study evaluated the relationships between the occurrence of recent and recurring natural disasters on the incidence of acute and chronic health outcomes at the census tract level in 500 cities across the United States between 2001 and 2015.

Methods:

Using the Centers for Disease Control and Prevention (CDC) 500 cities data set, the CDC Social Vulnerability Index, and the US Small Business Administration (SBA) Disaster Loan Database, we modeled the incidence of self-reported, poor mental and physical health, or a clinical diagnosis of high blood pressure or asthma in census tracts (N = 27 204 tracts in 500 cities) that had experienced recent or recurring natural disasters while controlling for social and environmental risk factors.

Results:

Communities that experienced a natural disaster in the previous 5 years compared to those that had not had a higher incidence of poor mental health (RR: 1.02, 95% CI: 1.01-1.02), poor physical health (RR: 1.03, 95% CI: 1.02-1.04), high blood pressure (RR: 1.04, 95% CI: 1.02-1.05), and asthma (RR: 1.01, 95% CI: 1.01-1.02). The incidence of these poor health outcomes increased 1-2% with each additional year that a community experienced a disaster.

Conclusions:

Prevention and preparedness plans that work to build resilience in communities before disasters should focus on closing the gap in environmental and social determinants that have been linked with disproportionate health burdens and slow recovery post-disaster.
Socio-ecological colonial transfers: trajectories of the Fascist agricultural enterprise in Libya (1922–43)
Authors: Biasillo Roberta
Published: March 2021

This paper intertwines the two historiographical concerns of migration and colonialism by exploring the case of Italian rule in North Africa from 1922 to 1943 and by adopting the analytic ground of the environment. The role played by the environment in targeting and shaping specific social groups, forming and grounding specific policies, creating and preventing social and natural transfers, has been overshadowed until now, particularly in relation to Italian colonialism. This study articulates the Fascist agricultural enterprise in Libya around the watershed event of the colony's 1932 pacification. To illustrate its development, it looks at the environment-making processes and transfers entailed in the transformation of the Italian colonial project. This reconstruction contributes to the environmental history subfields of migration and colonialism and invites historians to further explore the first decade of Italian rule in Libya and not to limit historical explorations to the lens of settler colonialism.
Evolution, diversity, and disparity of the tiger shark lineageGaleocerdoin deep time
Authors: Türtscher Julia , López-Romero Faviel A. , Jambura Patrick L. , Kindlimann René , Ward David J. , Kriwet Jürgen
Published: March 2021

Sharks have a long and rich fossil record that consists predominantly of isolated teeth due to the poorly mineralized cartilaginous skeleton. Tiger sharks (Galeocerdo), which represent apex predators in modern oceans, have a known fossil record extending back into the early Eocene (ca. 56 Ma) and comprise 22 recognized extinct and one extant species to date. However, many of the fossil species remain dubious, resulting in a still unresolved evolutionary history of the tiger shark genus. Here, we present a revision of the fossil record ofGaleocerdoby examining the morphological diversity and disparity of teeth in deep time. We use landmark-based geometric morphometrics to quantify tooth shapes and qualitative morphological characters for species discrimination. Employing this combined approach on fossil and extant tiger shark teeth, our results only support six species to represent valid taxa. Furthermore, the disparity analysis revealed that diversity and disparity are not implicitly correlated and thatGaleocerdoretained a relatively high dental disparity since the Miocene despite its decrease from four to one species. With this study, we demonstrate that the combined approach of quantitative geometric morphometric techniques and qualitative morphological comparisons on isolated shark teeth provides a useful tool to distinguish between species with highly similar tooth morphologies.
Middle-ear or mastoid granulation pathology associated with retraction of the pars flaccida and low-pitched tinnitus
Authors: Lou Z
Published: March 2021

Objective

This study aimed to evaluate the clinical features and outcomes of patients with middle-ear granulation pathologies associated with attic retractions.

Method

The clinical records of adult patients with middle-ear granulation pathologies and attic retractions confirmed via computed tomography and surgical exploration between January 2012 and January 2019 were retrospectively reviewed.

Results

A total of 59 patients were included. Endoscopic examination showed a normal pars tensa but retraction of the pars flaccida in all patients. No granulation tissue or debris were observed. Low-pitched tinnitus was the principal complaint of 55 patients (100 per cent), followed by ear fullness (14 patients, 23.7 per cent). Of the 59 patients, 52 patients (88.1 per cent) underwent canal wall up mastoidectomy and 7 patients (11.9 per cent) underwent endoscopic endaural atticoantrotomy. No ossicular chain destruction was evident. All patients were followed up for 12 months. Tinnitus disappeared completely in 48 patients (81.4 per cent), improved significantly in 9 patients (15.3 per cent) and improved mildly in 2 patients (3.3 per cent).

Conclusion

A granulation tissue pathology should be considered when a patient complains of low-pitched tinnitus and exhibits retraction of the pars flaccida. Computed tomography and surgical exploration should be scheduled.
The need for multidisciplinary conservation: a case study of Ceratozamia (Zamiaceae, Cycadales) in eastern Mexico
Authors: Martínez-Domínguez Lilí , Nicolalde-Morejón Fernando , Stevenson Dennis Wm. , Santiago-Jiménez Quiyari J. , Rojas-Soto Octavio , Vergara-Silva Francisco
Published: March 2021

As an evolutionary lineage cycads are rare, and the extinction risk is high for many species. The genus Ceratozamia, one of the most diverse in Mexico, is experiencing drastic reductions of its habitat. Ceratozamia is widely distributed along the Sierra Madre Oriental, a complex mountain range, in a region characterized by high ecological and cultural diversity. Since 1990, various conservation and management strategies have been applied to this taxon in Mexico but evidence for the effectiveness of these measures is lacking. Ceratozamia in the Mexican Sierra Madre Oriental is highly diverse and endemic, offering a model for analysing geographical distribution patterns with ecological niche modelling. It also presents an opportunity for assessing the success of conservation and management strategies that have been implemented in this area. Here, we examined three aspects that are considered fundamental for the development and evaluation of conservation strategies: (1) taxonomy, (2) ecology and (3) sociocultural anthropology. Our findings suggest a pessimistic outlook for the long-term survival of Ceratozamia species in their natural environment, indicating the need to review the current IUCN Cycad Action Plan for the genus. To improve the protection of Ceratozamia and other taxonomic and/or ecological assemblages, we encourage a multidisciplinary approach, with increased collaboration between natural and social scientists.
Ventilation History of the Nordic Seas Deduced From Pelagic‐Benthic Radiocarbon Age Offsets
Authors: Telesiński Maciej M. , Ezat Mohamed M. , Muschitiello Francesco , Bauch Henning A. , Spielhagen Robert F.
Published: March 2021

Changes in ocean circulation are considered a major driver of centennial‐to‐millennial scale climate variability during the last deglaciation. Using four sediment records from the Nordic Seas, we studied radiocarbon ventilation ages in subsurface and bottom waters to reconstruct past variations in watermass overturning. Planktic foraminiferal ages show significant spatial variability over most of the studied period. These differences suggest that the ventilation of the shallower subsurface waters is strongly influenced by local conditions such as sea‐ice and meltwater input, changes in mixed‐layer depth, and/or variable contributions of water masses with different 14C signatures. Despite covering a significant water depth range, the benthic foraminiferal records show common long‐term patterns, with generally weaker ventilation during stadials and stronger during interstadials. The Greenland Sea record differs the most from the other records, which can be explained by the greater depth and the geographical distance of this site. The benthic records reflect regional shifts in deep convection and suggest that the deep Nordic Seas have been generally bathed by a single, though changing, deep‐water mass analogous to the present‐day Greenland Sea Deep Water. Since significant offsets in ventilation ages are yielded by different taxonomic or ecological groups of benthic foraminifera, the use of uniform material seems a prerequisite to reconstruct bottom water ventilation histories.
Multidisciplinary Modeling of Mantle Lithosphere Structure Within the Superior Craton, North America
Authors: Snyder David B. , Savard Geneviève , Kjarsgaard Bruce A. , Vaillancourt Aeron , Thurston Phillips C. , Ayer John A. , Roots Eric
Published: March 2021

New 3D multi‐azimuthal receiver function analysis identified four regional seismic discontinuities dipping at 7–13° within the mantle of the Superior craton of North America; most are discordant to known major upper crustal structures. Widely observed crustal‐scale structures with near‐vertical axial planes striking east‐west indicate that the most recent and dominant phase of folding and horizontal shortening strain occurred during the Kenoran (D2) crustal deformation concurrent with Au‐mineralization and peak metamorphism at 2.72–2.66 Ga. Two mantle discontinuities strike 065° and 249°, dipping to the southeast and northwest, respectively. These strikes roughly parallel the northern margin of the Superior craton and some intra‐cratonic features such as the axis of the Quetico Basin. Two discontinuities strike 355° and 187°, dipping to the east and west, respectively, and parallel to the western margin of the craton. Our new observations reveal neither moderately dipping, east‐west striking discontinuities nor coherent eclogitic layers characteristic of modern plate tectonic subduction zones. Prominent east‐ and west‐dipping mantle structures relate best to a Paleoproterozoic (Trans‐Hudson) deformation, which is rarely observed in the crust. A new analysis of mantle xenoliths and xenocrysts indicates that carbonatitic metasomatism predominates above some discontinuities where strongly localized conductivity occurs whereas kimberlitic metasomatism predominates below the discontinuities in the broadly conductive mantle.
Formation of Continental Microplates Through Rift Linkage: Numerical Modeling and Its Application to the Flemish Cap and Sao Paulo Plateau
Authors: Neuharth Derek , Brune Sascha , Glerum Anne , Heine Christian , Welford J. Kim
Published: March 2021

Continental microplates are enigmatic plate boundary features, which can occur in extensional and compressional regimes. Here we focus on microplate formation and their temporal evolution in continental rift settings. To this aim, we employ the geodynamic finite element software ASPECT to conduct 3D lithospheric‐scale numerical models from rift inception to continental breakup. We find that depending on the strike‐perpendicular offset and crustal strength, rift segments connect or interact through one of four regimes: (1) an oblique rift, (2) a transform fault, (3) a rotating continental microplate or (4) a rift jump. We highlight that rotating microplates form at offsets >200 km in weak to moderately strong crustal setups. We describe the dynamics of microplate evolution from initial rift propagation, to segment overlap, vertical‐axis rotation, and eventually continental breakup. These models may explain microplate size and kinematics of the Flemish Cap, the Sao Paulo Plateau, and other continental microplates that formed during continental rifting worldwide.
A Comparison of the Location of the Mid‐Latitude Trough and Plasmapause Boundary
Authors: Weygand J. M. , Zhelavskaya I. , Shprits Y.
Published: March 2021

We have compared the location of the mid‐latitude trough observed in two dimensional vertical total electron content (vTEC) maps with four plasmapause boundary models, Radiation Belt Storm Probes (RBSP) observations, and IMAGE extreme ultraviolet (EUV) observations all mapped to the ionosphere pierce point using the Tsyganenko (1996) magnetic field line model. For this study, we examine four events over North America: one just after the October 13, 2012 storm, one during the April 20, 2002 double storm, another during a large substorm on January 26, 2013, and one quiet event on May 19, 2001. We have found that in general, the equatorward edge of the mid‐latitude trough is within several degrees in geographic latitude of the mapped model plasmapause boundary location, the plasmapause boundary identified with IMAGE EUV, and the location identified by the RBSP spacecraft. When the mid‐latitude trough is mapped to the inner magnetosphere, the observed boundary agrees with the plasmapause boundary models within two Earth Radii at nearly all local times in the nightside and the observed mid‐latitude boundary is within the uncertainty of the observations at most local times in the nightside. Furthermore, during dynamic solar wind conditions of April 20, 2002, the mid‐latitude trough observed in the vTEC maps propagates equatorward as the plasmapause boundary identified with IMAGE EUV moves earthward. Our results indicate that the mid‐latitude trough observed within the vTEC maps represents an additional means of identifying the plasmapause boundary location, which could result in improved plasmapause boundary models.
Energy Dissipation via Magnetic Reconnection Within the Coherent Structures of the Magnetosheath Turbulence
Authors: Wang Shimou , Wang Rongsheng , Lu Quanming , Burch J. L. , Wang Shui
Published: March 2021

A series of intermittent coherent structures was observed in magnetosheath turbulence in the form of magnetic peaks. These magnetic peaks are always accompanied with enhancement of local current density, and three of them are studied in detail because of their intense current density. Based on the magnetic field signals, magnetic curvatures, and the toroidal magnetic field lines, three peaks are identified as magnetic flux ropes. In each trailing part of these three peaks, an extremely thin electron current layer was embedded within a much broader ion‐scale current layer. The energy dissipation is evident within the peaks and direct evidence of magnetic reconnection was found within the thinnest electron current layer. The electrons were heated mainly in two regions of magnetic peaks, that is, the reconnecting current layer by parallel electric field and the trailing edges by Fermi and betatron mechanisms. These results suggest that the ion‐scale magnetic peaks are coherent structures associated with energy dissipation and electron heating in the magnetosheath. Thin current layers can be formed in magnetic peaks, and magnetic reconnection can play a significant role for the energy dissipation in magnetic peaks.
Constraints on the Upper Mantle Structure Beneath the Pacific From 3‐D Anisotropic Waveform Modeling
Authors: Kendall E. , Ferreira A. M. G. , Chang S.‐J. , Witek M. , Peter D.
Published: March 2021

Seismic radial anisotropy is a crucial tool to help constrain flow in the Earth's mantle. However, Earth structure beneath the oceans imaged by current 3‐D radially anisotropic mantle models shows large discrepancies. Here, we provide constraints on the radially anisotropic upper mantle structure beneath the Pacific by waveform modeling and subsequent inversion. Specifically, we objectively evaluate three 3‐D tomography mantle models which exhibit varying distributions of radial anisotropy through comparisons of independent real data sets with synthetic seismograms computed with the spectral‐element method. The data require an asymmetry at the East Pacific Rise (EPR) with stronger positive radial anisotropy ξ =  = 1.13–1.16 at ∼100 km depth to the west of the EPR than to the east (ξ = 1.11–1.13). This suggests that the anisotropy in this region is due to the lattice‐preferred orientation of anisotropic mantle minerals produced by shear‐driven asthenospheric flow beneath the South Pacific Superswell. Our new radial anisotropy constraints in the Pacific show three distinct positive linear anomalies at ∼100 km depth. These anomalies are possibly related to mantle entrainment at the Nazca‐South America subduction zone, flow at the EPR and from the South Pacific Superswell and shape‐preferred orientation (SPO) of melt beneath Hawaii. Radial anisotropy reduces with lithospheric age to ξ < 1.05 in the west at ∼100 km depth, which possibly reflects a deviation from horizontal flow as the mantle is entrained with subducting slabs, a change in temperature or water content that could alter the anisotropic olivine fabric or the SPO of melt.
Mesospheric Mountain Wave Activity in the Lee of the Southern Andes
Authors: Pautet P.‐D. , Taylor M. J. , Fritts D. C. , Janches D. , Kaifler N. , Dörnbrack A. , Hormaechea J. L.
Published: March 2021

Gravity waves (GWs) generated by orographic forcing, also known as mountain waves (MWs) have been studied for decades. First measured in the troposphere, then in the stratosphere, they were only imaged at mesospheric altitude in 2008. Their characteristics have been investigated during several recent observation campaigns, but many questions remain concerning their impacts on the upper atmosphere, and the effects of the background environment on their deep propagation. An Advanced Mesospheric Temperature Mapper (AMTM) and the Southern Argentina Agile MEteor Radar (SAAMER) have been operated simultaneously during the Austral winter 2018 from Rio Grande, Argentina (53.8°S). This site is located near the tip of South America, in the lee of the Andes Mountains, a region considered the largest MW hotspot on Earth (e.g., Eckermann & Preusse, 1999; Hendricks et al., 2014; Jiang et al., 2003, 2005, 2002; Wright et al., 2016). New AMTM image data obtained during a 6‐month period show almost 100 occurrences of MW signatures penetrating into the upper mesosphere. They are visible ∼30% of time during the period corresponding to the middle of the winter season (mid‐May to mid‐July). Their intermittency is highly correlated with the zonal wind controlled by the semi‐diurnal tide, revealing the direct effect of the atmospheric background on MW penetration into the mesosphere lower thermosphere (MLT, altitude 80–100 km). Measurements of their momentum fluxes (MFs) were determined to reach very large values (average for 36 events ∼250 m2/s2), providing strong evidence of the importance and impacts of small‐scale gravity waves at mesospheric altitudes.
A Global Empirical Model of Electron Density Profile in the F Region Ionosphere Basing on COSMIC Measurements
Authors: Li Qiaoling , Liu Libo , He Maosheng , Huang He , Zhong Jiahao , Yang Na , Zhang Man‐Lian , Jiang Jinzhe , Chen Yiding , Le Huijun , Cui Jun
Published: March 2021

The topside ionosphere accounts for a dominant part of the ionospheric total electron content, whereas accurate global modeling of topside ionospheric electron density (Ne) profile has not been fully achieved. In this study, a high precision Ne profile model, named α‐Chapman Based Electron Density Profile Model (α‐Chapman‐Based‐EDP), was built by using ∼4.5 million Ne profiles from the Constellation Observing System for Meteorology, Ionosphere, and Climate (COSMIC‐1) radio occultations. We first describe each of the profiles using five parameters of the α‐Chapman function, that is, peak density (NmF2) and height (hmF2) of F2 layer, scale height (Hm) as well as its altitude change rates, and then built a model for each of the parameters as a function of latitude, longitude, month, local time, and solar activity, through Empirical orthogonal function (EOF) analysis and Fourier expansion. Combining all the five models, we construct the α‐Chapman‐Based‐EDP. Compared with observations from COSMIC‐1 and ‐2, the model captures the ionospheric climatology well, such as solar activity dependence, seasonal variation, and spatial pattern, including the equatorial ionization anomaly and midlatitude trough as well as their variabilities. Our model can describe nearly 80% variability of Ne in F region. In contrast, the IRI2016 cannot well reproduce these characteristics, with errors higher than our model. The potential applications of our model were also discussed. A dense matrix data calculated by the model will be released in https://www.researchgate.net/profile/Qiaoling_Li5 with the permissions of COSMIC organizations.
MECOM permits pancreatic acinar cell dedifferentiation avoiding cell death under stress conditions
Authors: Backx Elyne , Wauters Elke , Baldan Jonathan , Van Bulck Mathias , Michiels Ellis , Heremans Yves , De Paep Diedert Luc , Kurokawa Mineo , Goyama Susumu , Bouwens Luc , Jacquemin Patrick , Houbracken Isabelle , Rooman Ilse
Published: March 2021

Maintenance of the pancreatic acinar cell phenotype suppresses tumor formation. Hence, repetitive acute or chronic pancreatitis, stress conditions in which the acinar cells dedifferentiate, predispose for cancer formation in the pancreas. Dedifferentiated acinar cells acquire a large panel of duct cell-specific markers. However, it remains unclear to what extent dedifferentiated acini differ from native duct cells and which genes are uniquely regulating acinar cell dedifferentiation. Moreover, most studies have been performed on mice since the availability of human cells is scarce. Here, we applied a non-genetic lineage tracing method of human pancreatic exocrine acinar and duct cells that allowed cell-type-specific gene expression profiling by RNA sequencing. Subsequent to this discovery analysis, one transcription factor that was unique for dedifferentiated acinar cells was functionally characterized. RNA sequencing analysis showed that human dedifferentiated acinar cells expressed genes in “Pathways of cancer” with a prominence of MECOM (EVI-1), a transcription factor that was not expressed by duct cells. During mouse embryonic development, pre-acinar cells also transiently expressed MECOM and in the adult mouse pancreas, MECOM was re-expressed when mice were subjected to acute and chronic pancreatitis, conditions in which acinar cells dedifferentiate. In human cells and in mice, MECOM expression correlated with and was directly regulated by SOX9. Mouse acinar cells that, by genetic manipulation, lose the ability to upregulate MECOM showed impaired cell adhesion, more prominent acinar cell death, and suppressed acinar cell dedifferentiation by limited ERK signaling. In conclusion, we transcriptionally profiled the two major human pancreatic exocrine cell types, acinar and duct cells, during experimental stress conditions. We provide insights that in dedifferentiated acinar cells, cancer pathways are upregulated in which MECOM is a critical regulator that suppresses acinar cell death by permitting cellular dedifferentiation.
HIF1α/HIF2α–Sox2/Klf4 promotes the malignant progression of glioblastoma via the EGFR–PI3K/AKT signalling pathway with positive feedback under hypoxia
Authors: Wang Pan , Zhao Lu , Gong Sheng , Xiong Shuanglong , Wang Junwei , Zou Dewei , Pan Jinyu , Deng Yangmin , Yan Qian , Wu Nan , Liao Bin
Published: March 2021

Previous studies have suggested that hypoxic responses are regulated by hypoxia-inducible factors (HIFs), which in turn promote the malignant progression of glioblastoma (GBM) by inhibiting apoptosis and increasing proliferation; these events lead to a poor prognosis of GBM patients. However, there are still no HIF-targeted therapies for the treatment of GBM. We have conducted series of experiments and discovered that GBM cells exhibit features indicative of malignant progression and are present in a hypoxic environment. Knocking out HIF1α or HIF2α alone resulted in no significant change in cell proliferation and cell cycle progression in response to acute hypoxia, but cells showed inhibition of stemness expression and chemosensitization to temozolomide (TMZ) treatment. However, simultaneously knocking out HIF1α and HIF2α inhibited cell cycle arrest and promoted proliferation with decreased stemness, making GBM cells more sensitive to chemotherapy, which could improve patient prognosis. Thus, HIF1α and HIF2α regulate each other with negative feedback. In addition, HIF1α and HIF2α are upstream regulators of epidermal growth factor (EGF), which controls the malignant development of GBM through the EGFR–PI3K/AKT–mTOR–HIF1α signalling pathway. In brief, the HIF1α/HIF2α–EGF/EGFR–PI3K/AKT–mTOR–HIF1α signalling axis contributes to the growth of GBM through a positive feedback mechanism. Finally, HIF1α and HIF2α regulate Sox2 and Klf4, contributing to stemness expression and inducing cell cycle arrest, thus increasing malignancy in GBM. In summary, HIF1α and HIF2α regulate glioblastoma malignant progression through the EGFR–PI3K/AKT pathway via a positive feedback mechanism under the effects of Sox2 and Klf4, which provides a new tumour development model and strategy for glioblastoma treatment.
Author Correction: A data-driven simulation platform to predict cultivars’ performances under uncertain weather conditions
Authors: de los Campos Gustavo , Pérez-Rodríguez Paulino , Bogard Matthieu , Gouache David , Crossa José
Published: March 2021

A Correction to this paper has been published: https://doi.org/10.1038/s41467-021-22384-w
First observation of seasonal variations in the meat and co-products of the snow crab (Chionoecetes opilio) in the Barents Sea
Authors: Solstad Runar Gjerp , Descomps Alexandre , Siikavuopio Sten Ivar , Karstad Rasmus , Vang Birthe , Dragøy Whitaker Ragnhild
Published: March 2021

The snow crab (Chionoecetes opilio), SC, is a newly established species in the Barents Sea. The snow crab fishery has established itself as a new and profitable industry in Norway in the last decade. The fishery started as a year-round fishery, without any information of possible seasonal variations in the quality of the product. In 2017 a total allowable catch was established by the Norwegian government, and the fisheries were subsequently closed during the summer months. In order to optimize fishing times, and to evaluate this growing industry in the Barents Sea, seasonal variations of the meat content of the clusters, as well as variations in content and quality of co-products were investigated, aiming to identify the seasons where the exploitation of different products from SC can be most profitable. The results show seasonal variations in meat content and in composition of co-products. The highest co-product quantities and meat content are from February to April, followed by a period from June to September with decreasing meat and co-products. Our recommendation is to capture the SC in the winter–spring period in the Barents Sea, supporting the current situation and creating most value for the fisheries.
Potential novel biomarkers for chronic lung allograft dysfunction and azithromycin responsive allograft dysfunction
Authors: Veraar Cecilia , Kliman Jonathan , Benazzo Alberto , Oberndorfer Felicitas , Laggner Maria , Hacker Philipp , Raunegger Thomas , Janik Stefan , Jaksch Peter , Klepetko Walter , Ankersmit Hendrik J. , Moser Bernhard
Published: March 2021

Chronic Lung Allograft Dysfunction (CLAD), manifesting as Bronchiolitis Obliterans Syndrome (BOS) or Restrictive Allograft Syndrome (RAS), is the main reason for adverse long-term outcome after Lung Transplantation (LTX). Until now, no specific biomarkers exist to differentiate between CLAD phenotypes. Therefore, we sought to find suitable cytokines to distinguish between BOS, RAS and Azithromycin Responsive Allograft Dysfunction (ARAD); and reveal potential similarities or differences to end-stage fibrotic diseases. We observed significantly increased Lipocalin-2 serum concentrations in RAS compared to BOS patients. In addition, in RAS patients immunohistochemistry revealed Lipocalin-2 expression in bronchial epithelium and alveolar walls. Patients with ARAD showed significantly lower Activin-A serum concentrations compared to Stable-LTX and BOS patients. Further, increased serum concentrations of Lipocalin-2 and Activin-A were predictors of worse freedom-from-CLAD in Stable-LTX patients. These biomarkers serve as promising serum biomarkers for CLAD prediction and seem suitable for implementation in clinical practice.
Fasciola hepatica hijacks host macrophage miRNA machinery to modulate early innate immune responses
Authors: Tran Nham , Ricafrente Alison , To Joyce , Lund Maria , Marques Tania M. , Gama-Carvalho Margarida , Cwiklinski Krystyna , Dalton John P. , Donnelly Sheila
Published: March 2021

Fasciola hepatica, a global worm parasite of humans and their livestock, regulates host innate immune responses within hours of infection. Host macrophages, essential to the first-line defence mechanisms, are quickly restricted in their ability to initiate a classic protective pro-inflammatory immune response. We found that macrophages from infected animals are enriched with parasite-derived micro(mi)RNAs. The most abundant of these miRNAs, fhe-miR-125b, is released by the parasite via exosomes and is homologous to a mammalian miRNA, hsa-miR-125b, that is known to regulate the activation of pro-inflammatory M1 macrophages. We show that the parasite fhe-miR-125b loads onto the mammalian Argonaut protein (Ago-2) within macrophages during infection and, therefore, propose that it mimics host miR-125b to negatively regulate the production of inflammatory cytokines. The hijacking of the miRNA machinery controlling innate cell function could be a fundamental mechanism by which worm parasites disarm the early immune responses of their host to ensure successful infection.
Differentiation of Mitragyna speciosa, a narcotic plant, from allied Mitragyna species using DNA barcoding-high-resolution melting (Bar-HRM) analysis
Authors: Tungphatthong Chayapol , Urumarudappa Santhosh Kumar J. , Awachai Supita , Sooksawate Thongchai , Sukrong Suchada
Published: March 2021

Mitragyna speciosa (Korth.) Havil. [MS], or “kratom” in Thai, is the only narcotic species among the four species of Mitragyna in Thailand, which also include Mitragyna diversifolia (Wall. ex G. Don) Havil. [MD], Mitragyna hirsuta Havil. [MH], and Mitragyna rotundifolia (Roxb.) O. Kuntze [MR]. M. speciosa is a tropical tree belonging to the Rubiaceae family and has been prohibited by law in Thailand. However, it has been extensively covered in national and international news, as its abuse has become more popular. M. speciosa is a narcotic plant and has been used as an opium substitute and traditionally used for the treatment of chronic pain and various illnesses. Due to morphological disparities in the genus, the identification of plants in various forms, including fresh leaves, dried leaf powder, and finished products, is difficult. In this study, DNA barcoding combined with high-resolution melting (Bar-HRM) analysis was performed to differentiate M. speciosa from allied Mitragyna and to assess the capability of Bar-HRM assays to identify M. speciosa in suspected kratom or M. speciosa-containing samples. Bar-HRM analysis of PCR amplicons was based on the ITS2, rbcL, trnH-psbA, and matK DNA barcode regions. The melting profiles of ITS2 amplicons were clearly distinct, which enabled the authentication and differentiation of Mitragyna species from allied species. This study reveals that DNA barcoding coupled with HRM is an efficient tool with which to identify M. speciosa and M. speciosa-containing samples and ensure the safety and quality of traditional Thai herbal medicines.
Author Correction: Precursor-surface interactions revealed during plasma-enhanced atomic layer deposition of metal oxide thin films by in-situ spectroscopic ellipsometry
Authors: Kilic Ufuk , Mock Alyssa , Sekora Derek , Gilbert Simeon , Valloppilly Shah , Melendez Giselle , Ianno Natale , Langell Marjorie , Schubert Eva , Schubert Mathias
Published: March 2021

An amendment to this paper has been published and can be accessed via a link at the top of the paper.
Author Correction: The causality from solar irradiation to ocean heat content detected via multi-scale Liang–Kleeman information flow
Authors: Wang Gang , Zhao Chang , Zhang Min , Zhang Yuanling , Lin Min , Qiao Fangli
Published: March 2021

An amendment to this paper has been published and can be accessed via a link at the top of the paper.
Chemisorption of nitronyl–nitroxide radicals on gold surface: an assessment of morphology, exchange interaction and decoherence time
Authors: Poggini Lorenzo , Lunghi Alessandro , Collauto Alberto , Barbon Antonio , Armelao Lidia , Magnani Agnese , Caneschi Andrea , Totti Federico , Sorace Lorenzo , Mannini Matteo
Published: March 2021

A multitechnique approach integrated by advanced computational characterization demonstrated the intact chemisorption of nitronyl–nitroxide radicals on Au(111) and allowed determination of its decoherence time.
The different composites of cellulose nanocrystals with d- or l-histidine
Authors: Gu Zehao , Lu Mengfan , Feng Kai , Jin Zhaoxia
Published: March 2021

The composite films of cellulose nanocrystal and histidine with d- or l-configuration presented the chirality-related difference in the self-assembled nanostructure of CNC, optical property, and the crystallization of amino acid.
Zeolitic octahedral niobium oxide with microchannels of seven-membered rings for photocatalytic H2 evolution from saline water
Authors: Qiu Chuntian , Zhu Qianqian , Yao Yanling , Zhang Zhenxin
Published: March 2021

A zeolitic octahedral niobium oxide was synthesized with high microporosity. A high catalytic activity for H2 evolution was achieved by the material.
Magnetic liquid metal loaded nano-in-micro spheres as fully flexible theranostic agents for SMART embolization
Authors: Wang Dawei , Wu Qirun , Guo Rui , Lu Chennan , Niu Meng , Rao Wei
Published: March 2021

Schematic illustration of soft magnetic liquid metal nanoparticles for the construction of multifunctional “nano-in-micro” embolic microspheres, and realization of dual-modality imaging guided and tri-modality therapeutic enhanced TACE.