bluuebunny/crossref_metadata_2025 huggingface dataset:
Maternal hypothyroidism in mice influences glucose metabolism in adult offspring
Authors: Kemkem Yasmine , Nasteska Daniela , de Bray Anne , Bargi-Souza Paula , Peliciari-Garcia Rodrigo A. , Guillou Anne , Mollard Patrice , Hodson David J. , Schaeffer Marie
Published: May 2020

Aims/hypothesis

During pregnancy, maternal metabolic disease and hormonal imbalance may alter fetal beta cell development and/or proliferation, thus leading to an increased risk for developing type 2 diabetes in adulthood. Although thyroid hormones play an important role in fetal endocrine pancreas development, the impact of maternal hypothyroidism on glucose homeostasis in adult offspring remains poorly understood.

Methods

We investigated this using a mouse model of hypothyroidism, induced by administration of an iodine-deficient diet supplemented with propylthiouracil during gestation.

Results

Here, we show that, when fed normal chow, adult mice born to hypothyroid mothers were more glucose-tolerant due to beta cell hyperproliferation (two- to threefold increase in Ki67-positive beta cells) and increased insulin sensitivity. However, following 8 weeks of high-fat feeding, these offspring gained 20% more body weight, became profoundly hyperinsulinaemic (with a 50% increase in fasting insulin concentration), insulin-resistant and glucose-intolerant compared with controls from euthyroid mothers. Furthermore, altered glucose metabolism was maintained in a second generation of animals.

Conclusions/interpretation

Therefore, gestational hypothyroidism induces long-term alterations in endocrine pancreas function, which may have implications for type 2 diabetes prevention in affected individuals.
Yang–Mills Measure and the Master Field on the Sphere
Authors: Dahlqvist Antoine , Norris James R.
Published: May 2020

We study the Yang–Mills measure on the sphere with unitary structure group. In the limit where the structure group has high dimension, we show that the traces of loop holonomies converge in probability to a deterministic limit, which is known as the master field on the sphere. The values of the master field on simple loops are expressed in terms of the solution of a variational problem. We show that, given its values on simple loops, the master field is characterized on all loops of finite length by a system of differential equations, known as the Makeenko–Migdal equations. We obtain a number of further properties of the master field. On specializing to families of simple loops, our results identify the high-dimensional limit, in non-commutative distribution, of the Brownian bridge in the group of unitary matrices starting and ending at the identity.
The use of whole-body cryotherapy: time- and dose-response investigation on circulating blood catecholamines and heart rate variability
Authors: Louis Julien , Theurot Dimitri , Filliard Jean-Robert , Volondat Marielle , Dugué Benoit , Dupuy Olivier
Published: May 2020

Purpose

A predominance of parasympathetic drive is observed following cold exposure. Such modulation of the autonomic nervous system (ANS) is associated with faster post-exercise recovery. Within this context, whole-body cryotherapy (WBC) has been spreading in sport medicine, though the optimal temperature and frequency are unclear. The aim of this study was to examine the effects of different cryotherapy conditions on the sympathovagal balance.

Methods

Forty healthy males were randomly assigned into five different groups (− 110 °C, − 60 °C, − 10 °C, control temperature [≃ 24 °C]) and undertook 5 WBC sessions over 5 consecutive days. Cardiac autonomic activity was assessed through heart rate variability (HRV) using power density of high frequency (HF), root-mean square difference of successive R–R intervals (RMSSD) and sympathovagal balance (LF/HF). Systemic sympathetic activity was assessed via circulating blood catecholamines.

Results

Mean weekly RMSSD (pre: 48 ± 22 ms, post: 68 ± 29 ms) and HF (pre: 607 ± 692 ms2, post: 1271 ± 1180 ms2) increased (p < 0.05) from pre to post WBC, only in the − 110 °C condition. A rise in plasma norepinephrine was found after the first − 110 °C WBC session only (pre: 173 ± 98, post: 352 ± 231 ng L−1, p < 0.01); whereas, it was not significant after the 5th session (pre: 161 ± 120, post: 293 ± 245 ng L−1, p = 0.15).

Conclusion

These results suggest that one − 110 °C WBC exposure is required to stimulate the ANS. After five daily exposures, a lower autonomic response was recorded compared to day one, therefore suggesting the development of physiological habituation to WBC.
MSC encapsulation in alginate microcapsules prolongs survival after intra-articular injection, a longitudinal in vivo cell and bead integrity tracking study
Authors: Khatab Sohrab , Leijs Maarten J. , van Buul Gerben , Haeck Joost , Kops Nicole , Nieboer Michael , Bos P. Koen , Verhaar Jan A. N. , Bernsen Monique , van Osch Gerjo J. V. M.
Published: May 2020

Mesenchymal stem cells (MSC) are promising candidates for use as a biological therapeutic. Since locally injected MSC disappear within a few weeks, we hypothesize that efficacy of MSC can be enhanced by prolonging their presence. Previously, encapsulation in alginate was suggested as a suitable approach for this purpose. We found no differences between the two alginate types, alginate high in mannuronic acid (High M) and alginate high in guluronic acid (High G), regarding MSC viability, MSC immunomodulatory capability, or retention of capsule integrity after subcutaneous implantation in immune competent rats. High G proved to be more suitable for production of injectable beads. Firefly luciferase-expressing rat MSC were used to track MSC viability. Encapsulation in high G alginate prolonged the presence of metabolically active allogenic MSC in immune competent rats with monoiodoacetate-induced osteoarthritis for at least 8 weeks. Encapsulation of human MSC for local treatment by intra-articular injection did not significantly influence the effect on pain, synovial inflammation, or cartilage damage in this disease model. MSC encapsulation in alginate allows for an injectable approach which prolongs the presence of viable cells subcutaneously or in an osteoarthritic joint. Further fine tuning of alginate formulation and effective dosage for might be required in order to improve therapeutic efficacy depending on the target disease.
Validation of risk models for control of leaf blotch diseases in wheat in the Nordic and Baltic countries
Authors: Jørgensen Lise Nistrup , Matzen Niels , Ficke Andrea , Nielsen Ghita C. , Jalli Marja , Ronis Antanas , Andersson Björn , Djurle Annika
Published: May 2020

Risk models for decisions on fungicide use based on weather data, disease monitoring, and control thresholds are used as important elements in a sustainable cropping system. The need for control of leaf blotch diseases in wheat (caused by Zymoseptoria tritici, Parastagonospora nodorum and Pyrenophora tritici-repentis) vary significantly across years and locations. Disease development is mainly driven by humidity events during stem elongation and heading. Two risk models were tested in field trials in order to identify situations favourable for the development of leaf blotch diseases in Lithuania, Norway, Sweden, Finland and Denmark. The Crop Protection Online (CPO) model uses days with precipitation (>1 mm), while the humidity model (HM) uses 20 continuous hours with relative humidity (RH) ≥ 85% as criteria for the need of a fungicide application. Forty-seven field trials were carried out during two seasons to validate these two risk-models against reference fungicide treatments. The season 2018 was dry and 2019 had an average precipitation profile. The two risk models with few exceptions provided acceptable disease control. In 2018, very few treatments were recommended by the models, saving 85–98% of treatments compared to the reference treatments, while in the wetter season 2019, 31% fewer applications were recommended. Based on specific criteria including fungicide input and net yield responses the models gave correct recommendations in 95% of the trials in 2018 and in 54–58% of the trials in 2019 compared with reference treatments dominated by 2–3 sprays. In comparison with single spray references, the models gave correct recommendations in 54–69% of the situations.
Molecular signature of eutopic endometrium in endometriosis based on the multi-omics integrative synthesis
Authors: Prašnikar Erika , Knez Jure , Kovačič Borut , Kunej Tanja
Published: May 2020

Purpose

To synthesise data from genome-wide studies reporting molecular signature of eutopic endometrium through the phases of the menstrual cycle in endometriosis.

Methods

Extraction of data from publications reporting genetic signatures characterising endometrium associated with endometriosis. The nomenclature of extracted differentially expressed transcripts and proteins was adopted according to the HUGO Gene Nomenclature Committee (HGNC). Loci were further sorted according to the different phases of the menstrual cycle, i.e. menstrual (M), proliferative (P), secretory (S), early-secretory (ES), mid-secretory (MS), late-secretory (LS), and not specified (N/S) if the endometrial dating was not available. Enrichment analysis was performed using the DAVID bioinformatics tool.

Results

Altered molecular changes were reported by 21 studies, including 13 performed at the transcriptomic, 6 at proteomic, and 2 at epigenomic level. Extracted data resulted in a catalogue of total 670 genetic causes with available 591 official gene symbols, i.e. M = 3, P = 188, S = 81, ES = 82, MS = 173, LS = 36, and N/S = 28. Enriched pathways included oestrogen signalling pathway, extracellular matrix organization, and endothelial cell chemotaxis. Our study revealed that knowledge of endometrium biology in endometriosis is fragmented due to heterogeneity of published data. However, 15 genes reported as dysregulated by at least two studies within the same phase and 33 significantly enriched GO-BP terms/KEGG pathways associated with different phases of the menstrual cycle were identified.

Conclusions

A multi-omics insight into molecular patterns underlying endometriosis could contribute towards identification of endometrial pathological mechanisms that impact fertility capacities of women with endometriosis.
Genetic and morphologic determination of diatom community composition in surface sediments from glacial and thermokarst lakes in the Siberian Arctic
Authors: Huang S. , Herzschuh U. , Pestryakova L. A. , Zimmermann H. H. , Davydova P. , Biskaborn B. K. , Shevtsova I. , Stoof-Leichsenring K. R.
Published: May 2020

Lakes cover large parts of the climatically sensitive Arctic landscape and respond rapidly to environmental change. Arctic lakes have different origins and include the predominant thermokarst lakes, which are small, young and highly dynamic, as well as large, old and stable glacial lakes. Freshwater diatoms dominate the primary producer community in these lakes and can be used to detect biotic responses to climate and environmental change. We used specific diatom metabarcoding on sedimentary DNA, combined with next-generation sequencing and diatom morphology, to assess diatom diversity in five glacial and 15 thermokarst lakes within the easternmost expanse of the Siberian treeline ecotone in Chukotka, Russia. We obtained 163 verified diatom sequence types and identified 176 diatom species morphologically. Although there were large differences in taxonomic assignment using the two approaches, they showed similar high abundances and diversity of Fragilariceae and Aulacoseiraceae. In particular, the genetic approach detected hidden within-lake variations of fragilarioids in glacial lakes and dominance of centric Aulacoseira species, whereas Lindavia ocellata was predominant using morphology. In thermokarst lakes, sequence types and valve counts also detected high diversity of Fragilariaceae, which followed the vegetation gradient along the treeline. Ordination analyses of the genetic data from glacial and thermokarst lakes suggest that concentrations of sulfate (SO42−), an indicator of the activity of sulfate-reducing microbes under anoxic conditions, and bicarbonate (HCO3−), which relates to surrounding vegetation, have a significant influence on diatom community composition. For thermokarst lakes, we also identified lake depth as an important variable, but SO42− best explains diatom diversity derived from genetic data, whereas HCO3− best explains the data from valve counts. Higher diatom diversity was detected in glacial lakes, most likely related to greater lake age and different edaphic settings, which gave rise to diversification and endemism. In contrast, small, dynamic thermokarst lakes are inhabited by stress-tolerant fragilarioids and are related to different vegetation types along the treeline ecotone. Our study demonstrated that genetic investigations of lake sediments can be used to interpret climate and environmental responses of diatoms. It also showed how lake type affects diatom diversity, and that such genetic analyses can be used to track diatom community changes under ongoing warming in the Arctic.
Chromium(VI) reduction and accumulation on the kaolinite surface in the presence of cationic soil flocculant
Authors: Szewczuk-Karpisz Katarzyna , Fijałkowska Gracja , Wiśniewska Małgorzata , Wójcik Grzegorz
Published: May 2020

Purpose

Heavy metal soluble forms pose a threat to plants, soil microflora, and microfauna. To limit their toxicity and mobility, various immobilizing additives are being developed. The main aim of the study was to determine the influence of soil flocculant (cationic polyacrylamide (CtPAM)) on the hexavalent chromium ion reduction and accumulation on the kaolinite surface. In this way, the efficiency of the selected polymer conditioner in the soil remediation was determined.

Materials and methods

The adsorbed amounts of Cr(VI) and CtPAM on the kaolinite surface was determined spectrophotometrically (spectrophotometer UV/Vis) using specific indicators. The structure of electrical double layer formed on the kaolinite surface in the mixed system of cationic polyacrylamide and Cr(VI) ions was described based on the adsorptive measurements, zeta potential measurements, as well as potentiometric titration. The kaolinite aggregation in the presence of CtPAM and/or Cr(VI) ions was determined spectrophotometrically and proved using SEM microscopy. The reduction process of Cr(VI) to Cr(III) occurring in the adsorption layer was determined by diffuse reflectance spectroscopy (DRS).

Results and discussion

The obtained results indicated that cationic polyacrylamide contributes to Cr(VI) reduction to Cr(III) form in the kaolinite suspension. This heavy metal ions are strongly adsorbed by the applied clay mineral, especially at pH 5 (then the Cr(VI)-adsorbed amount equals 5.42 mg/g). The CtPAM addition favors the Cr(VI) ion immobilization on the kaolinite surface. In the conditioner presence, the heavy metal-adsorbed amount is even at 7.34 mg/g. The adsorption of CtPAM and chromium(VI) ions induces changes in the kaolinite surface charge density and electrokinetic potential. What is more, both substances favors the kaolinite aggregation.

Conclusions

Cationic polyacrylamide may be considered a substance reducing the toxicity of chromium(VI) ions in the natural environment and decreasing their availability for soil organisms. It can improve the soil structure (by stimulating aggregation) and reduce environment pollution with heavy metals simultaneously.
Electric Arc Length-Voltage and Conductivity Characteristics in a Pilot-Scale AC Electric Arc Furnace
Authors: Pauna H. , Willms T. , Aula M. , Echterhof T. , Huttula M. , Fabritius T.
Published: June 2020

The heat transfer processes and the molten metal bath kinetics of the electric arc furnace are governed by the changes in the arc length and voltage. Thus, information on the electric arc behavior with respect to the voltage is important for accurate computation of the furnace processes and adjustment of the industrial furnace parameters. In this work, the length-voltage characteristics of electric arcs have been studied in a pilot-scale AC electric arc furnace with image analysis, electrical data from the furnace, and slag composition. The arc length was determined with image analysis and the relation between the arc length and voltage from test data. The relation between arc length and voltage was found to be non-linear and dependent on the slag composition. The voltage gradients of the arcs were evaluated as a function of arc length and sum of anode and cathode voltage drops resulting in a reciprocal relation. Furthermore, the electrical conductivity of the arc plasma with respect to arc length was estimated.
The structure of lay-concepts within the fear spectrum revealed using emotional verbal fluency
Authors: Gawda Barbara
Published: May 2020

Given the fact that natural language analysis can distinguish constituents of mental constructs, the present research was designed to investigate the structure of concepts related to the broad spectrum of emotions comprising worry, fear, anxiety, and panic, which in this article is referred to as the ‘fear spectrum’. A new technique presented here is based on a word association task and enables a description of the structure of emotion concepts. The technique is a variant of a verbal fluency task, i.e. emotional verbal fluency technique. Two studies have been conducted: the first to examine the cognitive structure of concepts within thefearspectrum (n = 280, 150 women, 130 men) and the second to confirm the stability of word association in thefeartasks and differentiation of thefearconcepts in relation to trait anxiety and dogmatism (n = 190, 100 women, 90 men). A hierarchical clustering analysis, based on the linguistic material, i.e. words produced by the participants for the task ofanxiety, was performed to present in what way the emotional verbal fluency technique can be applied to explore the structure of emotional concepts. According to our results, there is a relatively constant tendency in producing semantic clusters (emotional word association) among lay people. Moreover, produced clusters allow to describe the structure and to differentiate lay-concepts within thefearspectrum, such asworry, fear, anxiety, panic[respectively in Polish: obawa, lęk, strach, panika].
Conserving genetic resources for agriculture: economic implications of emerging science
Authors: Gollin Douglas
Published: June 2020

New challenges have arrived for the conservation of plant genetic resources for food and agriculture. Increased pressure on the environment, including the added threat of climate change, has had adverse effects on biodiversity and agricultural systems. Emerging science and new technologies have at the same time altered the scope of possibilities for collection, conservation, and utilization of genetic resources for agriculture. Taken together, these changes imply a need for a refocusing of global strategies for the management of genetic resources for agriculture. This paper argues that simple theoretical models provide relatively little guidance for key questions about genebank management. The fundamental uncertainty of scientific possibility and global futures makes it challenging – and perhaps futile – to attempt economic valuation of gene banks. A more useful application of economic tools will be in the prioritization of collection and conservation. Economic analysis may also offer useful insights into the efficient management of genetic resources.
Dephosphorylation of cGAS by PPP6C impairs its substrate binding activity and innate antiviral response
Authors: Li Mi , Shu Hong-Bing
Published: May 2020

The cyclic GMP-AMP (cGAMP) synthase (cGAS) plays a critical role in host defense by sensing cytosolic DNA derived from microbial pathogens or mis-located cellular DNA. Upon DNA binding, cGAS utilizes GTP and ATP as substrates to synthesize cGAMP, leading to MITA-mediated innate immune response. In this study, we identified the phosphatase PPP6C as a negative regulator of cGAS-mediated innate immune response. PPP6C is constitutively associated with cGAS in un-stimulated cells. DNA virus infection causes rapid disassociation of PPP6C from cGAS, resulting in phosphorylation of human cGAS S435 or mouse cGAS S420 in its catalytic pocket. Mutation of this serine residue of cGAS impairs its ability to synthesize cGAMP upon DNA virus infection. In vitro experiments indicate that S420-phosphorylated mcGAS has higher affinity to GTP and enzymatic activity. PPP6C-deficiency promotes innate immune response to DNA virus in various cells. Our findings suggest that PPP6C-mediated dephosphorylation of a catalytic pocket serine residue of cGAS impairs its substrate binding activity and innate immune response, which provides a mechanism for keeping the DNA sensor cGAS inactive in the absence of infection to avoid autoimmune response.
A Review on Nano-/Microstructured Materials Constructed by Electrochemical Technologies for Supercapacitors
Authors: Lv Huizhen , Pan Qing , Song Yu , Liu Xiao-Xia , Liu Tianyu
Published: May 2020

The article reviews the recent progress of electrochemical techniques on synthesizing nano-/microstructures as supercapacitor electrodes. With a history of more than a century, electrochemical techniques have evolved from metal plating since their inception to versatile synthesis tools for electrochemically active materials of diverse morphologies, compositions, and functions. The review begins with tutorials on the operating mechanisms of five commonly used electrochemical techniques, including cyclic voltammetry, potentiostatic deposition, galvanostatic deposition, pulse deposition, and electrophoretic deposition, followed by thorough surveys of the nano-/microstructured materials synthesized electrochemically. Specifically, representative synthesis mechanisms and the state-of-the-art electrochemical performances of exfoliated graphene, conducting polymers, metal oxides, metal sulfides, and their composites are surveyed. The article concludes with summaries of the unique merits, potential challenges, and associated opportunities of electrochemical synthesis techniques for electrode materials in supercapacitors.
Grade repetition and boys’ risk of being repeated in early schooling in Queensland, Australia
Authors: Anderson Robyn , Anderson Carla
Published: June 2020

Despite the fact that many research studies (Canon & Lipscomb, 2011 ; Jimerson, 2001 a, 2001 b, 2004 ; Martin, 2011 ) have shown that grade repetition offers few benefits to students, it continues to be used as an early intervention practice to address students’ low levels of readiness for school or early school failure. The study contributes to the evidence-based research on grade repetition in Australian schools by drawing on, and analysing, the most recent data on grade repetition from Queensland’s state education department, the Department of Education and Training. Descriptive statistics and relative risk ratio, used to analyse the data, found that boys aged 5 years are overrepresented in grade repetition in the first year of schooling, ‘Prep’, in Queensland state schools. Possible reasons for the disproportionate overrepresentation of boys aged 5 years repeated in Prep are discussed, together with recommendations for future policy and practice.
Phylogeny of the Eocene Antarctic Tapetinae Gray, 1851 (Bivalvia, Veneridae) from the La Meseta and Submeseta formations
Authors: Alvarez Maximiliano Jorge , del Río Claudia Julia
Published: June 2020

Systematic analysis shows that the Southern Hemisphere bivalve genus Retrotapes includes the Antarctic species R. antarcticus, R. newtoni, and R. robustus and recognizes for the first time the presence of Katelysia represented by K. florentinoi. Two new genera were erected in this study: Marciachlys new genus to include M. inflata new combination, and Adelfia new genus, which includes A. austrolissa new combination and A. omega new species from the Eocene of Antarctica, and the late Eocene Chilean A. arenosa new combination. Eurhomalea carlosi was synonymized with K. florentinoi; Cyclorismina marwicki with R. antarcticus; Gomphina iheringi was considered an indeterminate species; and Cockburnia lunulifera was excluded from the Tapetinae. These systematic assignments are supported by a phylogenetic analysis, which recognizes an Austral clade of Tapetinae, comprising all the genera mentioned above, along with Marcia, Paleomarcia, Atamarcia, and Protapes.

UUID: http://zoobank.org/a8c91a9f-99ec-4235-8416-d398771a3eb2
The GLEAM 4-Jy (G4Jy) Sample: I. Definition and the catalogue
Authors: White Sarah V. , Franzen Thomas M. O , Riseley Chris J. , Wong O. Ivy , Kapińska Anna D. , Hurley-Walker Natasha , Callingham Joseph R. , Thorat Kshitij , Wu Chen , Hancock Paul , Hunstead Richard W. , Seymour Nick , Swan Jesse , Wayth Randall , Morgan John , Chhetri Rajan , Jackson Carole , Weston Stuart , Bell Martin , For Bi-Qing , Gaensler B. M. , Johnston-Hollitt Melanie , Offringa André , Staveley-Smith Lister
Published: June 2020

The Murchison Widefield Array (MWA) has observed the entire southern sky (Declination,

$\delta< 30^{\circ}$

) at low radio frequencies, over the range 72–231MHz. These observations constitute the GaLactic and Extragalactic All-sky MWA (GLEAM) Survey, and we use the extragalactic catalogue (EGC) (Galactic latitude,

$|b| >10^{\circ}$

) to define the GLEAM 4-Jy (G4Jy) Sample. This is a complete sample of the ‘brightest’ radio sources (

$S_{\textrm{151\,MHz}}>4\,\text{Jy}$

), the majority of which are active galactic nuclei with powerful radio jets. Crucially, low-frequency observations allow the selection of such sources in an orientation-independent way (i.e. minimising the bias caused by Doppler boosting, inherent in high-frequency surveys). We then use higher-resolution radio images, and information at other wavelengths, to morphologically classify the brightest components in GLEAM. We also conduct cross-checks against the literature and perform internal matching, in order to improve sample completeness (which is estimated to be

$>95.5$

%). This results in a catalogue of 1863 sources, making the G4Jy Sample over 10 times larger than that of the revised Third Cambridge Catalogue of Radio Sources (3CRR;

$S_{\textrm{178\,MHz}}>10.9\,\text{Jy}$

). Of these G4Jy sources, 78 are resolved by the MWA (Phase-I) synthesised beam (

$\sim2$

arcmin at 200MHz), and we label 67% of the sample as ‘single’, 26% as ‘double’, 4% as ‘triple’, and 3% as having ‘complex’ morphology at

$\sim1\,\text{GHz}$

(45 arcsec resolution). We characterise the spectral behaviour of these objects in the radio and find that the median spectral index is

$\alpha=-0.740 \pm 0.012$

between 151 and 843MHz, and

$\alpha=-0.786 \pm 0.006$

between 151MHz and 1400MHz (assuming a power-law description,

$S_{\nu} \propto \nu^{\alpha}$

), compared to

$\alpha=-0.829 \pm 0.006$

within the GLEAM band. Alongside this, our value-added catalogue provides mid-infrared source associations (subject to 6” resolution at 3.4

$\mu$

m) for the radio emission, as identified through visual inspection and thorough checks against the literature. As such, the G4Jy Sample can be used as a reliable training set for cross-identification via machine-learning algorithms. We also estimate the angular size of the sources, based on their associated components at

$\sim1\,\text{GHz}$

, and perform a flux density comparison for 67 G4Jy sources that overlap with 3CRR. Analysis of multi-wavelength data, and spectral curvature between 72MHz and 20GHz, will be presented in subsequent papers, and details for accessing all G4Jy overlays are provided at https://github.com/svw26/G4Jy.
Moraines and late-glacial stratigraphy in central Lake Superior
Authors: Colman Steven M. , Breckenridge Andy , Zoet Lucas K. , Wattrus Nigel J. , Johnson Thomas C.
Published: June 2020

Seismic-reflection surveys of the Isle Royale sub-basin, central Lake Superior, reveal two large end moraines and associated glacial sediments deposited during the last cycle of the Laurentide Ice Sheet in the basin. The Isle Royale moraines directly overlie bedrock and are cored with dense, acoustically massive till intercalated down-ice with acoustically stratified outwash. Till and outwash are overlain by glacial varves, a lower red unit and an upper gray unit.

The maximum extent of late Younger Dryas-age readvance into the western Lake Superior basin is uncertain, but it was probably controlled by both ice dynamics and climate. Our data indicate that during retreat from the maximum, the ice paused just long enough to construct the outer of the two moraines, >100 m high, and then retreated to the inner moraine, during which time most of the lower glacial-lacustrine sequence (red varves) was deposited. Retreat from the inner moraine coincided with a marked flux of icebergs at the calving margin and a change to gray varves. Rapid retreat may be related to both an influx of meltwater from Glacial Lake Agassiz about 10,500 cal yr BP and retreat of the calving margin down an adverse slope into the Isle Royale sub-basin.
Trans-fatty acids alter the gut microbiota in high-fat-diet-induced obese rats
Authors: Hua Yinan , Fan Rong , Zhao Lei , Tong Chao , Qian Xiaomeng , Zhang Meng , Xiao Rong , Ma Weiwei
Published: June 2020

The gut microbiota is directly influenced by dietary components, and it plays critical roles in chronic diseases. Excessive consumption of trans-fatty acids (TFA) is associated with obesity induced by alterations in gut microbiota, but the links between obesity and gut microbiota remain unclear. Therefore, studies examining the impact of TFA on intestinal microflora are essential. In our study, we performed 16S ribosomal RNA gene sequencing on faecal samples from Sprague–Dawley rats fed a basal diet (control (CON) group), high-fat (HF) diet (diet-induced obesity (DIO) group) or TFA diets (1 % TFA group and 8 % TFA group) for 8 weeks to investigate the effects of TFA/HF diets on obesity and gut microbiota composition. We found that the TFA/HF diets significantly induced obesity and changes in blood and brain physiological parameters of the rats. The relative abundance of the phyla Firmicutes and Bacteroidetes was inversely altered in the three test groups compared with the CON group. Proteobacteria increased slightly in the DIO, 1 % TFA and 8 % TFA groups. The genus Bacteroides increased in the DIO and 1 % TFA groups, but Muribaculaceae decreased in all experimental groups compared with the CON group. Moreover, significant differences were observed among clusters of orthologous group functional categories of the four dietary groups. Our observations suggested that the TFA/HF diets induced obesity and dysfunction of gut microbiota. Gut dysbiosis might mediate the obesity effects of TFA/HF diets.
Cross-chain interoperability among blockchain-based systems using transactions
Authors: Pillai Babu , Biswas Kamanashis , Muthukkumarasamy Vallipuram
Published: June 2020

The blockchain is an emerging technology which has the potential to improve many information systems. In this regard, the applications and the platform they are built on must be able to connect and communicate with each other. However, the current blockchain platforms have several limitations, such as lack of interoperability among different systems. The existing platforms of blockchain applications operate only within their own networks. Even though the underlying technology is similar, it relies on centralized third-party mediators to exchange or retrieve information from other blockchain networks. The current third-party intermediaries establish trust and security by preserving a centralized ledger to track ‘account balances’ and vouch for a transaction’s authenticity. The inability for independent blockchains to communicate with one another is an inherent problem in the decentralized systems. Lack of appropriate inter-blockchain communication puts a strain on the mainstream adoption of blockchain. It is evident that blockchain technology has the potential to become a suitable solution for some systems if it can scale and is able to cross communicate with other systems. For the multisystem blockchain concept to become a reality, a mechanism is required that would connect and communicate with multiple entities’ blockchain systems in a distributed fashion (without any intermediary), while maintaining the property of trust and integrity built by individual blockchains. In this article, we propose a mechanism that provides cross-chain interoperability using transactions.
Grazing incidence X-ray diffraction measurement of silver nanoparticles in metal-assisted etching of silicon
Authors: Tang Yunhui , Wang Bo , Xue Rui , Yan Hui
Published: June 2020

Silicon nanowires (SiNWs) were fabricated in a metal-assisted chemical etching method with two steps including dipping silicon wafers in AgNO3/HF solutions and then in H2O2/HF solutions. Grazing incidence X-ray diffraction measurements with a set of incidence angles were carried out on the resulting samples to detect characteristics of silver nanoparticles in the etched silicon. Compared with the uniform size of silver nanoparticles on the surface, the silver nanoparticles in etched silicon were found with size increasing and content decreasing corresponding to the depths. Based on the silver size increasing phenomenon, a detailed supplementary hypothesis about SiNWs formation was proposed about silver disintegration and redeposition in the later stage of silicon etching. For 2, 3, 4, and 8 mM AgNO3 solutions used to study their effect on the SiNWs, it was found that a higher quantity of Ag+ concentration such as 8 mM were not beneficial for producing good quality SiNWs.
Association between maternal adverse childhood experiences and mental health problems in offspring: An intergenerational study
Authors: Doi Satomi , Fujiwara Takeo , Isumi Aya
Published: June 2020

The aim of this study is to examine the association between maternal adverse childhood experiences (ACEs) and mental health problems in adolescent offspring. Data were obtained from the population-based Kochi Child Health Impact of Living Difficulty (K-CHILD) study in 2016, and participants were 10,810 children in the fifth grade (3,144 pairs), eighth grade (3,497 pairs), and eleventh grade (4,169 pairs) living in Kochi Prefecture, Japan. Mothers of participating children were asked about their ACEs, childhood social economic status, current mental and physical health, current social economic status, positive parenting behaviors, child maltreatment, marital status, and child behavior problems using the Strength and Difficulty Questionnaire. Children reported their depressive symptoms using the Depression Self-Rating Scale. Children of mothers with a larger number of ACEs showed higher levels of behavior problems (p for trend <.001) and depressive symptoms (p for trend <.001), adjusting for potential confounders. In particular, maternal psychological distress mediated the association between maternal ACEs and child mental health. The adverse effects of maternal ACEs may have a direct intergenerational impact on behavior problems and depressive symptoms in adolescent offspring. Further studies to elucidate possible mediators are needed.
STREAMLINED SOLUTIONS TO MULTILEVEL SPARSE MATRIX PROBLEMS
Authors: NOLAN TUI H. , WAND MATT P.
Published: June 2020

We define and solve classes of sparse matrix problems that arise in multilevel modelling and data analysis. The classes are indexed by the number of nested units, with two-level problems corresponding to the common situation, in which data on level-1 units are grouped within a two-level structure. We provide full solutions for two-level and three-level problems, and their derivations provide blueprints for the challenging, albeit rarer in applications, higher-level versions of the problem. While our linear system solutions are a concise recasting of existing results, our matrix inverse sub-block results are novel and facilitate streamlined computation of standard errors in frequentist inference as well as allowing streamlined mean field variational Bayesian inference for models containing higher-level random effects.
Conceptualizing the business corporation: insights from history
Authors: Gindis David
Published: June 2020

The purpose of this symposium is to shed light on the genealogy of the idea of a business corporation, an economic institution which has long been regarded with a mixture of awe and apprehension. Each of the four original contributions addresses the history of some of its key features. In the process, each contributor reveals some of the insights that history has to teach us regarding the central concepts that inform contemporary debates about the nature of the corporation, the contours of the corporation's purpose, the sources of corporate power, the functions of corporate law, the duties of directors, the status of shareholders, and the legitimacy of corporate rights.
Calibration of the loop probe for the near-field measurement
Authors: Dimitrijević Tijana , Atanaskovic Aleksandar , Dončov Nebojša S. , Thomas David W. P. , Smartt Christopher , Baharuddin Mohd Hafiz
Published: June 2020

Accurate near-field measurements for either deterministic or stochastic electromagnetic fields characterization require a relevant process that removes the influence of the probes, transmission lines, and measurement circuits. The main part of the experimental work presented here is related to a calibration procedure of a test setup consisting of a microstrip test structure and a scanning loop probe. The calibration characteristic, obtained by comparing measured and simulated results, is then used to convert the measured voltage into the magnetic field across and along the microstrip line at the specific height above it. By performing the measurements and simulations of the same test structure with the loop probe in the presence of an additional scanning probe, the influence of the additional probe to the measured output is thoroughly investigated and relevant corrections are given. These corrections can be important when two-point correlation measurement is required, especially in scanning points when two probes are mutually close.
Exchange Dynamics of Typical Emerging and Legacy Persistent Organic Pollutants at the Air‐Water Interface Over a Strongly Human‐Influenced Large River Estuary
Authors: Guo Tianfeng , Li Yuanyuan , Lin Tian , Wu Zilan , Jiang Yuqing , Guo Zhigang
Published: May 2020

To explore the riverine or atmospheric influence on the source‐sink fates of typical persistent organic pollutants (POPs): polybrominated diphenyl ethers (PBDEs) and polychlorinated biphenyls (PCBs) in the large river estuary, atmospheric and seawater samples were collected simultaneously over a whole year at a remote small island in the Yangtze River Estuary (YRE), the East China Sea. A comparable net input of BDE‐209 from the atmosphere to the sea for both air‐water gas exchange and dry/wet deposition was observed. The gas deposition of BDE‐209 had a strong dependence on the gaseous concentration, which was in turn governed by atmospheric transport. For Br<10‐BDEs, which have been prohibited in recent years, the gas exchange almost reached equilibrium at the air‐water interface during the whole observation period. However, a strong net gas volatilization was observed for legacy ΣICESPCBs especially in the flood season, and the volatilization was significantly associated with ambient parameter‐wind speed. These remarkably different exchange dynamics of PBDEs and PCBs at the air‐water interface over the YRE could be attributed to their primary emission intensity and inconsistent environmental transport pathways. The reversal of the source‐sink fates of BDE‐209 and legacy PCBs suggest that the strongly human‐influenced large river estuary water could act as a source‐sink buffer for POPs during the switch from approved to prohibited usage.
Are Geysers a Signal of Magma Intrusion Under Yellowstone?
Authors: Klemetti Erik
Published: May 2020

Steamboat Geyser, the world’s tallest, is in the midst of one of its largest periods of activity. Is it linked to new magma intruding under the Yellowstone caldera?
Chemical Weathering of Loess and Its Contribution to Global Alkalinity Fluxes to the Coastal Zone During the Last Glacial Maximum, Mid‐Holocene, and Present
Authors: Börker Janine , Hartmann Jens , Amann Thorben , Romero‐Mujalli Gibran , Moosdorf Nils , Jenkins Chris
Published: May 2020

Loess sediments are windblown silt deposits with, in general, a carbonate grain content of up to 30%. While regionally, loess was reported to increase weathering fluxes substantially, the influence on global weathering fluxes remains unknown. Especially on glacial‐interglacial time scales, loess weathering fluxes might have contributed to land‐ocean alkalinity flux variability since the loess areal extent during glacial epochs was larger. To quantify loess weathering fluxes, global maps representing the loess distribution were compiled. Water chemistry of rivers draining recent loess deposits suggests that loess contributes over‐proportionally to alkalinity concentrations if compared to the mean of alkalinity concentrations of global rivers (~4,110 µeq L−1 for rivers draining loess deposits and ~1,850 µeq L−1 for the total of global rivers), showing comparable alkalinity concentration patterns in rivers as found for carbonate sedimentary rocks. Loess deposits, covering ~4% of the ice‐ and water‐free land area, increase calculated global alkalinity fluxes to the coastal zone by 16%. The new calculations lead to estimating a 4% higher global alkalinity flux during the Last Glacial Maximum (LGM) compared to present fluxes. The effect of loess on that comparison is high. Alkalinity fluxes from silicate‐dominated lithological classes were ~28% and ~30% lower during the LGM than recent (with loess and without loess, respectively), and elevated alkalinity fluxes from loess deposits compensated for this. Enhanced loess weathering dampens due to a legacy effect changes in silicate‐dominated lithologies over the glacial‐interglacial time scale.
Years of the Maritime Continent
Authors: Yoneyama K. , Zhang C.
Published: May 2020

Years of the Maritime Continent (YMC) is a multiyear international program with participants from over 15 countries. Its overarching goal is to expedite the progress toward improving understanding and prediction of the local oceanic and atmospheric multiscale variability of the Indo‐Pacific Maritime Continent (MC) and its global impacts. YMC is motivated by the unique role of the MC in both the local and global weather climate systems, our lack of understanding of the key processes governing this role, and persistent systematic biases and errors in numerical model output for the region. YMC builds a comprehensive observational data set of the MC weather climate system, encourages observation‐modeling integration, and educates the next generation of scientists who will be the core workforce and leaders to further advance the study of the MC.
Observations of a Deep Submesoscale Cyclonic Vortex in the Arabian Sea
Authors: de Marez Charly , Carton Xavier , Corréard Stéphanie , L'Hégaret Pierre , Morvan Mathieu
Published: May 2020

Submesoscale coherent vortices (SCVs) are numerous in high‐resolution numerical simulations, but their observations are scarce. Among the few in situ available measurements of SCVs, a vast majority concern anticyclones. No cyclonic SCV with large dynamical Rossby number (|ζ/f| > 1) has ever been sampled. This suggested that such small cyclones may lack robustness. Here, we present in situ measurements of an intense cyclonic SCV in the Arabian Sea. This eddy lay at 600 m depth, with a Rossby number
and a dynamical Rossby number |ζ/f| > 1.5. This cyclone was most likely generated at the mouth of the Gulf of Aden. It trapped and advected Red Sea Water, from there on. This highlights the role of deep SCVs in the spreading of salty waters across the Arabian Sea.
Ice‐Wedge Evidence of Holocene Winter Warming in the Canadian Arctic
Authors: Holland Kira M. , Porter Trevor J. , Froese Duane G. , Kokelj Steven V. , Buchanan Casey A.
Published: May 2020

Arctic summer temperatures mostly cooled over the last ~7 kyr, owing to decreasing summer insolation. However, knowledge of the winter season is limited in the Arctic paleoclimate literature. Here we develop a composite record of δ18O from ice wedges—a winter precipitation archive—to reconstruct changes in winter climate in the northwestern Canadian Arctic since ~7.4 kyr b2k. Our record shows a long‐term δ18O enrichment (+(0.14 ± 0.10)‰ kyr−1), suggesting winter temperatures increased since the mid‐Holocene, a finding that is corroborated by reconstructions from the Siberian Arctic. Winter warming over the last ~7 kyr is consistent with increasing winter insolation and greenhouse gas forcing. This study provides some of the first insights on the sensitivity of winter temperatures in the Canadian Arctic to past, and potentially future, climate forcings, and contributes to a more seasonally holistic understanding of the Arctic system.
Spectral Broadening of NWC Transmitter Signals in the Ionosphere
Authors: Xia Zhiyang , Chen Lunjin , Zhima Zeren , Parrot Michel
Published: May 2020

In this study, we use about 6.5 years of observation of Detection of Electromagnetic Emissions Transmitted from Earthquake Regions (DEMETER) satellite to study the spectral broadening of NWC ground transmitter signals and examine key parameters that control the width and intensity of the broadening power. First, we analyze a typical spectral broadening event, with enhanced wave intensity between lower hybrid resonance frequency and NWC signal frequency (19.8 kHz). The width and intensity of broadening power are positively proportional to the NWC wave amplitude. A following statistical analysis reveals a similar dependence on the NWC wave amplitude. The statistical analysis also indicates a significantly negative correlation of broadening spectral intensity and width with the background plasma density. The observations are consistent with existing theories predicting that lower plasma density drives a lower threshold for spectral broadening.
Role of Fluid Injection on Earthquake Size in Dynamic Rupture Simulations on Rough Faults
Authors: Maurer Jeremy , Dunham Eric M. , Segall Paul
Published: May 2020

An outstanding question for induced seismicity is whether the volume of injected fluid and/or the spatial extent of the resulting pore pressure and stress perturbations limit rupture size. We simulate ruptures with and without injection‐induced pore pressure perturbations, using 2‐D dynamic rupture simulations on rough faults. Ruptures are not necessarily limited by pressure perturbations when (1) background shear stress is above a critical value, or (2) pore pressure is high. Both conditions depend on fault roughness. Stress heterogeneity from fault roughness primarily determines where ruptures stop; pore pressure has a secondary effect. Ruptures may be limited by fluid volume or pressure perturbation extent when background stress and fault roughness are low, and the maximum pore pressure perturbation is less than 10% of the background effective normal stress. Future work should combine our methodology with simulation of the loading, injection, and nucleation phases to improve understanding of injection‐induced ruptures.