bluuebunny/crossref_metadata_2025 huggingface dataset:
Tail asymptotics of an infinitely divisible space-time model with convolution equivalent Lévy measure
Authors: Stehr Mads , Rønn-Nielsen Anders
Published: February 2021

We consider a space-time random field on ${{\mathbb{R}^d} \times {\mathbb{R}}}$ given as an integral of a kernel function with respect to a Lévy basis with a convolution equivalent Lévy measure. The field obeys causality in time and is thereby not continuous along the time axis. For a large class of such random fields we study the tail behaviour of certain functionals of the field. It turns out that the tail is asymptotically equivalent to the right tail of the underlying Lévy measure. Particular examples are the asymptotic probability that there is a time point and a rotation of a spatial object with fixed radius, in which the field exceeds the level x, and that there is a time interval and a rotation of a spatial object with fixed radius, in which the average of the field exceeds the level x.
Scale-free percolation in continuous space: quenched degree and clustering coefficient
Authors: Dalmau Joseba , Salvi Michele
Published: February 2021

Spatial random graphs capture several important properties of real-world networks. We prove quenched results for the continuous-space version of scale-free percolation introduced in [14]. This is an undirected inhomogeneous random graph whose vertices are given by a Poisson point process in$\mathbb{R}^d$. Each vertex is equipped with a random weight, and the probability that two vertices are connected by an edge depends on their weights and on their distance. Under suitable conditions on the parameters of the model, we show that, for almost all realizations of the point process, the degree distributions of all the nodes of the graph follow a power law with the same tail at infinity. We also show that the averaged clustering coefficient of the graph isself-averaging. In particular, it is almost surely equal to the annealed clustering coefficient of one point, which is a strictly positive quantity.
The martingale comparison method for Markov processes
Authors: Köpfer Benedikt , Rüschendorf Ludger
Published: February 2021

Comparison results for Markov processes with respect to function-class-induced (integral) stochastic orders have a long history. The most general results so far for this problem have been obtained based on the theory of evolution systems on Banach spaces. In this paper we transfer the martingale comparison method, known for the comparison of semimartingales to Markovian semimartingales, to general Markov processes. The basic step of this martingale approach is the derivation of the supermartingale property of the linking process, giving a link between the processes to be compared. This property is achieved using the characterization of Markov processes by the associated martingale problem in an essential way. As a result, the martingale comparison method gives a comparison result for Markov processes under a general alternative but related set of regularity conditions compared to the evolution system approach.
Self-exciting multifractional processes
Authors: Harang Fabian A. , Lagunas-Merino Marc , Ortiz-Latorre Salvador
Published: February 2021

We propose a new multifractional stochastic process which allows for self-exciting behavior, similar to what can be seen for example in earthquakes and other self-organizing phenomena. The process can be seen as an extension of a multifractional Brownian motion, where the Hurst function is dependent on the past of the process. We define this by means of a stochastic Volterra equation, and we prove existence and uniqueness of this equation, as well as giving bounds on the p-order moments, for all $p\geq1$. We show convergence of an Euler–Maruyama scheme for the process, and also give the rate of convergence, which is dependent on the self-exciting dynamics of the process. Moreover, we discuss various applications of this process, and give examples of different functions to model self-exciting behavior.
The coastal lowland of northwestern Germany as an archive of Holocene landscape evolution: basis for a spatial evaluation of Stone Age settlement patterns in the Dornumer tidal basin
Authors: Becker Thorsten , Siegmüller Annette
Published: February 2021

The ‘Wadden Sea Archive of landscape evolution, climate change and settlement history’ project (WASA) focuses on the analysis of marine sediment archives from the East Frisian Wadden Sea region. It aims at understanding the formation of palaeolandscapes since the end of the last ice age. One part of the project studies the possible correlation and shift of archaeological settlement patterns, climate change and sea-level rise through time in order to derive archaeological expectancy maps. In this paper we present our findings for a quantifiable set of Stone Age sites in the area of the prehistorical Dornumer tidal basin, discussing them against the background of coastal environmental factors and the applied methodology of our modelling. To enable spatial analysis of these sites, we developed a palaeographic elevation model, which was subsequently flooded at 2000-year intervals between the Boreal and early Subboreal periods. Particular challenges are posed by the dynamics of marine transgression, the related changes in the natural environment and their spatial extent. As a result of our GIS-based approach, the model can be extended geographically and provides a basis for future research.
Experimental Plastic Reactivation of Pseudotachylyte‐Filled Shear Zones
Authors: Passelègue François X. , Tielke Jacob , Mecklenburgh Julian , Violay Marie , Deldicque Damien , Di Toro Giulio
Published: February 2021

Pseudotachylytes are fine‐grained fault rocks that solidify from melt that is produced in fault zones during earthquakes. Exposed sections of natural fault zones reveal evidence of postseismic plastic deformation (i.e., reactivation) of pseudotachylyte, which suggests these rocks may contribute to aseismic slip behavior in regions of repeated seismicity. To measure the plastic flow behavior of pseudotachylyte, we performed high‐temperature deformation experiments on pseudotachylyte from the Gole Larghe Fault Zone, Italy. Plastic reactivation of pseudotachylyte occurs at temperatures above 700°C for strain rates accessible during laboratory experiments. Extrapolation of experimental results to natural conditions demonstrates that pseudotachylyte deforms via diffusion creep at crustal conditions and is much weaker than host rocks in seismically active regions. Importantly, the presence of plastically deforming pseudotachylyte may influence the thickness of the seismogenic layer in some fault zones that experience repeated seismicity.
Diffuse Auroral Electron Scattering by Electrostatic Electron Cyclotron Harmonic Waves in the Dayside Magnetosphere
Authors: Lou Yuequn , Cao Xing , Ni Binbin , Tu Weichao , Gu Xudong , Fu Song , Xiang Zheng , Ma Xin
Published: February 2021

Although electrostatic electron cyclotron harmonic (ECH) waves are frequently observed in the dayside magnetosphere, their effects on the formation of dayside diffuse aurora remain poorly understood. In this study, we quantitatively evaluate the efficiency of dayside ECH wave scattering in producing the electron diffuse aurora precipitation during a typical ECH wave event by calculating the quasi‐linear bounce‐averaged scattering rates. We find that dayside ECH waves can efficiently pitch angle scatter diffuse auroral electrons on timescales of a few hours to ∼1 day over a broad range of electron energy and equatorial pitch angle α
eq, that is, from ∼300 eV to 10 keV with α
eq from the loss cone to 45°. Especially for ∼300 eV–2 keV electrons, the scattering rates can even approach the strong diffusion limit, resulting in an almost fully filled loss cone. Our results confirm the significant role of ECH waves in driving the dayside diffuse aurora.
Mapping and Interpreting the Uppermost Mantle Reflectivity Beneath Central and South‐West Iberia
Authors: Palomeras I. , Ayarza P. , Andrés J. , Álvarez‐Valero A. M. , Gómez‐Barreiro J. , Díaz J. , Alcalde J. , Carbonell R.
Published: February 2021

At least two sub‐Moho reflectors have been identified in different seismic refraction and wide‐angle reflection experiments conducted in western Iberia since the early 1990s. The wavelet kinematics and characteristics of the shallowest event are probably produced by an increase in P‐wave velocity that forward modeling places at ∼70–75 km depth beneath the Ossa‐Morena Zone (OMZ) shallowing up to 50–60 km beneath the Central Iberian Zone (CIZ). Synthetic modeling suggests that the coda and amplitude of this arrival may correspond to a ∼10‐km‐thick heterogeneous layer. We used a two‐dimensional second‐order finite‐difference acoustic full wavefield modeling scheme with an input model which includes a layer of randomly distributed bodies thinner than one‐fourth of the wavelength of the source waves and ΔVp = ±0.1 km/s at the considered depth range. The resulting synthetic data reproduce well the observed amplitudes and codas because of the constructive interferences caused by this heterogeneous zone. The origin of this layer also discussed here in detail, is very likely related to the phase transition from spinel to garnet lherzolite, the so‐called Hales discontinuity. A second reflection also observed in some of the experiments suggests the presence of a velocity inversion at greater depths. Forward modeling places this discontinuity at around 90 km depth beneath the OMZ, deepening to 105–110 km depth beneath the southeast CIZ and shallowing up to 80 km depth in the northeast CIZ. The observed characteristics of this event are consistent with those of the lithosphere‐asthenosphere boundary.
Long‐Term Carbon Sinks in Marsh Soils of Coastal Louisiana are at Risk to Wetland Loss
Authors: Baustian Melissa M. , Stagg Camille L. , Perry Carey L. , Moss Leland C. , Carruthers Tim J. B.
Published: February 2021

Coastal marshes are essential habitats for soil carbon accumulation and burial, which can influence the global carbon budget. Coastal Louisiana has extensive marsh habitats (fresh, intermediate, brackish, and saline) where soil cores were collected to a depth of 100 cm at 24 sites to assess long‐term carbon accumulation and burial rates. Select soil depth intervals were analyzed for bulk density, total carbon, and radionuclide (137Cs and 210Pb) dating. Marsh habitat maps (years 1949–2013) were also used to determine the most frequently occurring habitat at each field site. Over 5 decades, half of the sites transitioned between marsh habitats at least once. Saline marshes tended to have lower mean total carbon density (0.04 ± 0.002 g cm−3) and lower mean long‐term total carbon accumulation rates (211 ± 46 g TC m−2 yr−1, n = 5, based on 210Pb) compared to the other marsh habitats. Using marsh habitat specific accumulation rates and area, the total carbon burial rate for coastal Louisiana in year 2013 was estimated at 4.3 Tg TC yr−1 which accounts for about 5%–21% of the estimated tidal wetland burial rate globally. Historically, about 1.0 Tg TC yr−1 was lost due to reduced marsh area from 1949 to 2013. With no coastal restoration activity, the predicted wetland loss over the next 50 years could reduce carbon burial in coastal Louisiana to 2.1 Tg TC yr−1, a reduction of about 50% from the year 2013 rate, with potential to significantly alter the global carbon budget.
Using Big Data to Measure Environmental Inclusivity in Cities
Authors: Dacey James
Published: February 2021

Lower-income urban communities bear the brunt of environmental burdens, even in wealthy green cities around the world.
Deep learning identification for citizen science surveillance of tiger mosquitoes
Authors: Pataki Balint Armin , Garriga Joan , Eritja Roger , Palmer John R. B. , Bartumeus Frederic , Csabai Istvan
Published: February 2021

Global monitoring of disease vectors is undoubtedly becoming an urgent need as the human population rises and becomes increasingly mobile, international commercial exchanges increase, and climate change expands the habitats of many vector species. Traditional surveillance of mosquitoes, vectors of many diseases, relies on catches, which requires regular manual inspection and reporting, and dedicated personnel, making large-scale monitoring difficult and expensive. New approaches are solving the problem of scalability by relying on smartphones and the Internet to enable novel community-based and digital observatories, where people can upload pictures of mosquitoes whenever they encounter them. An example is the Mosquito Alert citizen science system, which includes a dedicated mobile phone app through which geotagged images are collected. This system provides a viable option for monitoring the spread of various mosquito species across the globe, although it is partly limited by the quality of the citizen scientists’ photos. To make the system useful for public health agencies, and to give feedback to the volunteering citizens, the submitted images are inspected and labeled by entomology experts. Although citizen-based data collection can greatly broaden disease-vector monitoring scales, manual inspection of each image is not an easily scalable option in the long run, and the system could be improved through automation. Based on Mosquito Alert’s curated database of expert-validated mosquito photos, we trained a deep learning model to find tiger mosquitoes (Aedes albopictus), a species that is responsible for spreading chikungunya, dengue, and Zika among other diseases. The highly accurate 0.96 area under the receiver operating characteristic curve score promises not only a helpful pre-selector for the expert validation process but also an automated classifier giving quick feedback to the app participants, which may help to keep them motivated. In the paper, we also explored the possibilities of using the model to improve future data collection quality as a feedback loop.
Exploring the conservation of Alzheimer-related pathways between H. sapiens and C. elegans: a network alignment approach
Authors: Apostolakou Avgi E. , Sula Xhuliana K. , Nastou Katerina C. , Nasi Georgia I. , Iconomidou Vassiliki A.
Published: February 2021

Alzheimer disease (AD) is a neurodegenerative disorder with an –as of yet– unclear etiology and pathogenesis. Research to unveil disease processes underlying AD often relies on the use of neurodegenerative disease model organisms, such as Caenorhabditis elegans. This study sought to identify biological pathways implicated in AD that are conserved in Homo sapiens and C. elegans. Protein–protein interaction networks were assembled for amyloid precursor protein (APP) and Tau in H. sapiens—two proteins whose aggregation is a hallmark in AD—and their orthologs APL-1 and PTL-1 for C. elegans. Global network alignment was used to compare these networks and determine similar, likely conserved, network regions. This comparison revealed that two prominent pathways, the APP-processing and the Tau-phosphorylation pathways, are highly conserved in both organisms. While the majority of interactions between proteins in those pathways are known to be associated with AD in human, they remain unexamined in C. elegans, signifying the need for their further investigation. In this work, we have highlighted conserved interactions related to AD in humans and have identified specific proteins that can act as targets for experimental studies in C. elegans, aiming to uncover the underlying mechanisms of AD.
Effect of electrolyte flow on a gas evolution electrode
Authors: Abdelghani-Idrissi Soufiane , Dubouis Nicolas , Grimaud Alexis , Stevens Philippe , Toussaint Gwenaëlle , Colin Annie
Published: February 2021

In this study, the effect of flow of the electrolyte on an electrolysis cell and a zinc cell is investigated. The gain of energy brought by the flow is discussed and compared to the viscous losses in the cells. We point out that the balance between the gained electrical power and the viscous loss power is positive only if the hydrodynamic resistance of the circuit is correctly designed and further comment on the economical viability of the whole process. A model of the studied phenomena is proposed in the last section. This analytical model captures the dynamics of the process, gives the optimal flowing conditions and the limits of the energetical rentability of the process. This study shows that the use of flowing electrolyte in zinc–air batteries can be energetically profitable with the appropriate flowing conditions.
Episomal HPV16 responsible for aggressive and deadly metastatic anal squamous cell carcinoma evidenced in peripheral blood
Authors: Péré Hélène , Vernet Raphael , Pernot Simon , Pavie Juliette , Robillard Nicolas , Puech Julien , Lameiras Sonia , Lucas Marie-Laure , Nicolas Alain , Badoual Cécile , Rance Bastien , Bélec Laurent , Weiss Laurence , Wack Maxime , Veyer David
Published: February 2021

Archival tissue samples collected longitudinally from a patient who died from HPV16-induced high-grade anal intraepithelial squamous cell carcinoma with vertebral HPV16–positive metastasis were retrospectively analyzed by the Capture-HPV method (Capt-HPV) followed by Next-Generation Sequencing (NGS). Full length nucleotide sequences of the same HPV16 were identified from the initial and second anal biopsy samples, from plasma sample and from vertebral metastasis biopsy. Remarkably, HPV was episomal in each sample. The HPV genome sequence was closest to the HPV16 Qv18158E variant subtype (A1 lineage) exhibiting base substitutions and deletions in 7 and 2 HPV loci, respectively. In conclusion, the powerful Capt-HPV followed by NGS allows evidencing the detailed cartography of tumoral and circulating HPV DNA, giving rise to a unique and unexpected episomal virus molecular status in a context of aggressive carcinoma, underlying the importance of HPV status and its association with clinical features for further prospective studies.
A genome-wide association and polygenic risk score study on abnormal electrocardiogram in a Chinese population
Authors: Wang Mengqiao , Gao Jiaqi , Shi Yang , Zhao Xing
Published: February 2021

Electrocardiography is a common and widely-performed medical examination based on the measurement and evaluation of electrocardiogram (ECG) to assess the up-to-date cardiac rhythms and thus suggest the health conditions of cardiovascular system and on a larger level the individual’s wellness. Abnormal ECG assessment from the detection of abnormal heart rhythms may have clinical implications including blood clots in formation, ongoing heart attack, coronary artery blockage, etc. Past genetic-phenotypic research focused primarily on the physical parameters of ECG but not the medical evaluation. To unbiasedly uncover the underlying links of genetic variants with normal vs. abnormal ECG assessment, a genome-wide association study (GWAS) is carried out in a 1006-participant cohort of Chinese population effectively genotyped for 243487 single nucleotide polymorphisms (SNPs). Both age and sex are influential factors, and six novel SNPs are identified for potential association with abnormal ECG. With the selected SNPs, a polygenic risk score (PRS) differentiates the case–control subgroups, and correlates well with increased risk of abnormal ECG. The findings are reproduced in an independent validation cohort. The derived PRS may function as a potential biomarker for prospectively screening the high-risk subgroup of heart issues in the Chinese population.
Optical coherence tomography angiography and Humphrey field analyser for macular capillary non-perfusion evaluation in branch retinal vein occlusion
Authors: Terashima Hiroko , Okamoto Fumiki , Hasebe Hiruma , Ueda Eriko , Yoshida Hiromitsu , Fukuchi Takeo
Published: February 2021

We non-invasively evaluated macular non-perfused areas (m-NPAs) of branch retinal vein occlusion (BRVO) using optical coherence tomography (OCT) angiography and the Humphrey visual field analyser 10-2 programme (HFA 10-2). We enrolled 30 patients (30 eyes) with macular oedema secondary to BRVO. OCT angiography was used to photograph the macula at 6 × 6-mm; sizes of m-NPAs in the superficial capillary plexus (SCP) and deep capillary plexus (DCP) were measured in four areas. For HFA 10-2, we divided the actual measurement threshold of 68 points into four areas and calculated the mean central visual field sensitivity (CVFS). The correlation between the mean m-NPA and mean CVFS (dB) in each area was examined. There was a strong correlation between the m-NPA of each region detected in SCP and DCP, and the mean CVFS of each corresponding area (SCP: r = − 0.83, r = − 0.64, r = − 0.73, and r = − 0.79; DCP: r = − 0.82, r = − 0.71, r = − 0.71, and r = − 0.70), p values were < 0.001 for all. m-NPAs were associated with decreased visual field sensitivity in BRVO. Non-invasive m-NPA evaluation was possible using OCT angiography and HFA 10-2.
An exploratory study into the influence of laterality and location of hippocampal sclerosis on seizure prognosis and global cortical thinning
Authors: Mansouri Alireza , Germann Jurgen , Boutet Alexandre , Elias Gavin J. B. , Karmur Brij , Neudorfer Clemens , Loh Aaron , McAndrews Mary Pat , Ibrahim George M. , Lozano Andres M. , Valiante Taufik A.
Published: February 2021

In mesial temporal lobe epilepsy (mTLE), the correlation between disease duration, seizure laterality, and rostro-caudal location of hippocampal sclerosis has not been examined in the context of seizure severity and global cortical thinning. In this retrospective study, we analyzed structural 3 T MRI from 35 mTLE subjects. Regions of FLAIR hyperintensity (as an indicator of sclerosis)—based on 2D coronal FLAIR sequences—in the hippocampus were manually segmented, independently and in duplicate; degree of segmentation agreement was confirmed using the DICE index. Segmented lesions were used for separate analyses. First, the correlation of cortical thickness with disease duration and seizure focus laterality was explored using linear model regression. Then, the relationship between the rostro-caudal location of the FLAIR hyperintense signal and seizure severity, based on the Cleveland Clinic seizure freedom score (ccSFS), was explored using probabilistic voxel-wise mapping and functional connectivity analysis from normative data. The mean DICE Index was 0.71 (range 0.60–0.81). A significant correlation between duration of epilepsy and decreased mean whole brain cortical thickness was identified, regardless of seizure laterality(p < 0.05). The slope of cortical volume loss over time, however, was greater in subjects with right seizure focus. Based on probabilistic voxel-wise mapping, FLAIR hyperintensity in the posterior hippocampus was significantly associated with lower ccSFS scores (greater seizure severity). Finally, the right hippocampus was found to have greater brain-wide connectivity, compared to the left side, based on normative connectomic data. We have demonstrated a significant correlation between duration of epilepsy and right-sided seizure focus with global cortical thinning, potentially due to greater brain-wide connectivity. Sclerosis along the posterior hippocampus was associated with greater seizure severity, potentially serving as an important biomarker of seizure outcome after surgery.
New insight into the photocatalytic degradation of organic pollutant over BiVO4/SiO2/GO nanocomposite
Authors: Trinh Dang Trung Tri , Channei Duangdao , Nakaruk Auppatham , Khanitchaidecha Wilawan
Published: February 2021

The nanocomposite of BiVO4-based material has been synthesized by one-step solvent method. The morphological, physical, chemical properties of the nanocomposite have been investigated. The results revealed that the surface area of BiVO4, BiVO4/SiO2 and BiVO4/SiO2/GO was 11.13, 28.47 and 43.93 m2/g, respectively. The structural test by XRD proved that the nanocomposites were monoclinic phase of bismuth vanadate. Adsorption and photocatalytic degradation were two main mechanisms that strongly related to pollutant removal efficiency (i.e., methylene blue and phenol). The BiVO4/SiO2/GO nanocomposite obtained the greatest MB removal efficiency due to its high adsorption ability from high surface area, whereas the photocatalytic degradation was insignificant mechanism. In contrast, the relatively low adsorption ability of BiVO4/SiO2/GO nanocomposite was observed when the pollutant was phenol due to negative charge and high stability of phenoxide ions, then the photocatalytic degradation became the main mechanism for phenol removal. The phenol removal efficiency reached approximately 70% in 6 h with H2O2 assistance. The combination of SiO2 and GO improved the surface property of BiVO4-based photocatalyst, however the excessive combination ratio generated the excellent adsorbent material rather than the photocatalyst. Hence, the optimal combination ratio is essential to archive the greatest nanocomposite for photocatalytic application.
Leukocyte related parameters in older adults with metabolically healthy and unhealthy overweight or obesity
Authors: Zhang Shan-Shan , Yang Xue-Jiao , Ma Qing-Hua , Xu Yong , Chen Xing , Wang Pei , Pan Chen-Wei
Published: February 2021

It remains unclear whether leukocyte-related parameters could be used as biomarkers to differentiate metabolically unhealthy overweight/obesity (MUO) from metabolically healthy overweight/obesity (MHO). We aimed to examine the differences in the distribution of leukocyte-related parameters between older adults with MHO and MUO and the correlations of leukocyte-related parameters with individual components of metabolic abnormality. In the Weitang Geriatric Diseases Study on older Chinese adults aged 60 years or above, 404 individuals with MHO and 480 with MUO contributed to the analysis. Overweight/obesity was defined as body mass index (BMI) of 25 kg/m2 or more. MHO and MUO were discriminated based on the Adult Treatment Panel III (ATP III) criteria. Leukocyte-related parameters were assessed using an automated hematology analyzer. All leukocyte-related parameters except monocytes were elevated in MUO group compared with MHO group (all P < 0.05). The prevalence of MUO increased by 24% with each 109/L increase of leukocytes after adjusting for confounders in the multiple-adjusted model (P < 0.01) and each unit elevation of other parameters except lymphocytes and monocytes were significantly associated with the presence of MUO (all P < 0.01). Trend tests revealed a linear trend for the association between MUO and all the leukocyte-related parameters (all P for trend < 0.05). Significant interactions between leukocyte-related parameters and sex on the presence of MUO were observed (all P value for interaction < 0.05). Higher leukocyte-related parameters were found in patients with MUO than those with MHO and were associated with higher prevalence of MUO which seems to be sex-dependent. Further studies are needed to see whether these parameters could be used as biomarkers for the screening or diagnosis for MUO in clinical or public health practice.
Author Correction: Comparative transcriptome analysis of Sclerotinia sclerotiorum revealed its response mechanisms to the biological control agent, Bacillus amyloliquefaciens
Authors: Yang Xiaoxiang , Zhang Lei , Xiang Yunjia , Du Lei , Huang Xiaoqin , Liu Yong
Published: February 2021

An amendment to this paper has been published and can be accessed via a link at the top of the paper.
Characterizing an allosteric inhibitor-induced inactive state in with-no-lysine kinase 1 using Gaussian accelerated molecular dynamics simulations
Authors: Jonniya Nisha Amarnath , Sk Md Fulbabu , Kar Parimal
Published: February 2021

The binding of an allosteric inhibitor in WNK1 leads to the inactive state.
Characterization of the mechanical properties of van der Waals heterostructures of stanene adsorbed on graphene, hexagonal boron–nitride and silicon carbide
Authors: Rahman Md. Habibur , Chowdhury Emdadul Haque , Redwan Didarul Ahasan , Mitra Shailee , Hong Sungwook
Published: February 2021

Stanene could be integrated with other 2D nanomaterials such as graphene, hBN, and SiC in the form of vertical heterostructures to improve mechanical strength.
Metal-catalyzed silylation of sp3C–H bonds
Authors: Li Bin , Dixneuf Pierre H.
Published: February 2021

Metal-catalyzed activations of inert sp3C–H bonds have recently brought a revolution in the synthesis of useful molecules and molecular materials, due to the interest of the formed sp3C–SiR3 silanes, stable organometallic species, and for further functionalizations that sp3C–H bonds cannot reach directly.
A family of luminescent metal–organic frameworks: synthesis, structure, and sensing studies
Authors: Pulijala Hariprasad , Rao Tentu Nageswara , Ahmed Faheem , Prashanthi Y.
Published: February 2021

Herein we report three novel luminescent metal–organic frameworks (MOFs) viz. [Co(bpeb)(hfipbb)0.5]n (LCo-1), [Zn(bpeb)2(hfipbb)]n (L-Zn) and [Co(bpeb)2(oba)]n (LCo-2) which were synthesized through the solvothermal method and characterized by SC-XRD.
Direct conversion of cellulose to ethyl levulinate catalysed by modified fibrous mesoporous silica nanospheres in a co-solvent system
Authors: Zhang Zhi , Huang Zhihang , Yuan Hong
Published: February 2021

A KCC-1/Al–SO3H catalyst with Si/Al = 5 was prepared to directly catalyse the synthesis of ethyl levulinate from cellulose in an ethanol/toluene co-solvent system. A reaction yield of 28.8 mol% was achieved after 6 h at 200 °C.
Metal-free visible-light-induced aerobic oxidation of α-diazoesters leading to α-ketoesters in air
Authors: Liu Ruisheng , Liu Qishun , Meng Haoran , Ding Hongyu , Hao Jindong , Ji Zhongyin , Yue Huilan , Wei Wei
Published: February 2021

A metal-free and visible-light-induced strategy has been established for the construction of α-ketoesters via aerobic oxidation of α-diazoesters with dioxygen in air at room temperature.
Evaluating the cytotoxicity of Ge–Sb–Se chalcogenide glass optical fibres on 3T3 mouse fibroblasts
Authors: Mabwa David , Kubiena Teo , Parnell Harriet , Su Rong , Furniss David , Tang Zhuoqi , Leach Richard , Benson Trevor M. , Scotchford Colin A. , Seddon Angela B.
Published: February 2021

We present a study that aims to evaluate the cytotoxicity of Ge20Sb10Se70at% glass optical fibres on 3T3 mouse fibroblast cells. To observe the toxicity of these optical fibres, 3T3 fibroblast proliferation was investigated.
Molecular dynamics investigation on the interaction of human angiotensin-converting enzyme with tetrapeptide inhibitors
Authors: Liu Xiaoting , Wang Zheren , Gao Yawen , Liu Chunlei , Wang Ji , Fang Li , Min Weihong , Zhang Ji-Long
Published: February 2021

Molecular dynamics simulation results implemented that tetra-peptide YRHP is the “best” ACE inhibitor with the strongest binding affinity.
In(ONf)3-catalyzed 7-membered carbon-ring-forming annulation of heteroarylindoles with α,β-unsaturated carbonyl compounds
Authors: Tsuchimoto Teruhisa , Johshita Takahiro , Sambai Kazuhiro , Saegusa Naoki , Hayashi Takumi , Tani Tomohiro , Osano Mana
Published: February 2021

We developed the two recipes, on the indium-catalyzed reductive and oxidative 7-membered carbon-ring-forming annulations of heteroarylindoles with a,β-unsaturated carbonyl compounds.
Effect of Noise on Speech Intelligibility and Perceived Listening Effort in Head and Neck Cancer
Authors: Eadie Tanya L. , Durr Holly , Sauder Cara , Nagle Kathleen , Kapsner-Smith Mara , Spencer Kristie A.
Published: February 2021

Purpose

This study (a) examined the effect of different levels of background noise on speech intelligibility and perceived listening effort in speakers with impaired and intact speech following treatment for head and neck cancer (HNC) and (b) determined the relative contribution of speech intelligibility, speaker group, and background noise to a measure of perceived listening effort.

Method

Ten speakers diagnosed with nasal, oral, or oropharyngeal HNC provided audio recordings of six sentences from the Sentence Intelligibility Test. All speakers were 100% intelligible in quiet: Five speakers with HNC exhibited mild speech imprecisions (speech impairment group), and five speakers with HNC demonstrated intact speech (HNC control group). Speech recordings were presented to 30 inexperienced listeners, who transcribed the sentences and rated perceived listening effort in quiet and two levels (+7 and +5 dB SNR) of background noise.

Results

Significant Group × Noise interactions were found for speech intelligibility and perceived listening effort. While no differences in speech intelligibility were found between the speaker groups in quiet, the results showed that, as the signal-to-noise ratio decreased, speakers with intact speech (HNC control) performed significantly better (greater intelligibility, less perceived listening effort) than those with speech imprecisions in the two noise conditions. Perceived listening effort was also shown to be associated with decreased speech intelligibility, imprecise speech, and increased background noise.

Conclusions

Speakers with HNC who are 100% intelligible in quiet but who exhibit some degree of imprecise speech are particularly vulnerable to the effects of increased background noise in comparison to those with intact speech. Results have implications for speech evaluations, counseling, and rehabilitation.
Stator inter‐turn faults diagnosis in induction motors using zero‐sequence signal injection
Authors: Otero Marcial , de la Barrera Pablo M. , Bossio Guillermo R. , Leidhold Roberto
Published: February 2021

This study presents a strategy for stator inter‐turn faults diagnosis in induction motors (IMs) operating under time‐variable load and time‐variable speed conditions. The strategy consists in injecting a zero‐sequence high‐frequency signal in order to analyse variations in the stator inductances. Incipient stator inter‐turn faults are detected by a simple signal processing of the derivatives of the currents. A feature of the strategy is that the zero‐sequence high‐frequency signal is generated by the inverter that feeds the machine, without modifying the standard space vector modulation of the IM‐drive. Experimental results show that faults representing <1% of the stator winding can be detected, as well as the phase location of the fault, validating this proposal.
Predictive event‐triggered H∞ load frequency control for hybrid power systems under denial‐of‐service attacks
Authors: Hossain Md Musabbir , Peng Chen
Published: February 2021

In this study, a novel predictive event‐triggered load frequency control has been developed for a hybrid power system with renewable energy sources (RESs) to deal with denial‐of‐service (DoS) attacks, where the DoS duration (the time attack lasts) are boundless. A predictive event‐triggered transmission scheme is built for the multi‐area hybrid power systems under DoS attacks to reduce the load of network bandwidth while maintaining adequate levels of performance. Therefore, an observer‐based predictive controller is developed in the presence of both external disturbances and DoS attacks by formulating the LFC problem as a disturbance attenuation issue. In the proposed method, a hybrid power system with RESs is used to achieve novel and better security strategies. Based on the new model, sufficient conditions are obtained using the Lyapunov stability theory to ensure a stable multi‐area hybrid power system with a prescribed performance. Moreover, an algorithm is provided to obtain the control strategy of DoS attacks. Finally, the simulation of a hybrid power system with RESs is presented to demonstrate the effectiveness of the proposed method in dealing with the DoS attacks.
Balanced principal component for 3D shape recognition using convolutional neural networks
Authors: Luo Wenjie , Zhang Han , Ni Peng , Tian Xuedong
Published: February 2021

Currently, PCA (principal component analysis) is widely used in many neural networks and has become a crucial part of the convolutional neural network (CNN) feature extraction. However, whether PCA is suitable for this process remains to be elucidated. The authors proposed a new method called balanced principal component (BPC) that generates a balanced local feature and combines with CNN as a layer to cope with the fusion problem. Specifically, BPC layer includes regionalisation module and average compression PCA (AC‐PCA) module. First, they used regionalisation module to generate some sub‐region that focuses on the local feature in each view. Secondly, the AC‐PCA module is a computational process that enlarges the feature matrix by PCA and eventually compacts the matrix to a one‐dimensional (1D) vector by AC. Next, all 1D vectors are compacted by AC to obtain a multi‐dimensional balance. Finally, they designed this layer with an end‐to‐end trainable structure to promote the feature extraction task of CNN. They addressed 3D shapes using a projection method that is pre‐trained on ImageNet and migration learning on ModelNet dataset. By comparing with the state‐of‐the‐art network, they achieved a significant gain in performance of retrieval and classification tasks.
Edge‐guided single facial depth map super‐resolution using CNN
Authors: Zhang Fan , Liu Na , Chang Liang , Duan Fuqing , Deng Xiaoming
Published: February 2021

In recent years, consumer depth cameras have been widely used in digital entertainment and human‐machine interaction due to the advantages of real‐time performance and low cost. Facial depth maps have shown great potential in 3D‐face‐related studies. However, disadvantages of low resolution and precision limit its further applications. In this work, the authors propose an edge‐guided convolutional neural network for single facial depth map super‐resolution. It consists of two parts: an edge prediction sub‐network and a depth reconstruction sub‐network. The edge prediction sub‐network generates an edge guidance map to guide the depth reconstruction sub‐network to recover sharp edges and fine structures. Effective data augmentation methods are proposed as well. The network is patch‐based and able to cope with any size of the input depth maps. In addition, it is insensitive to the face pose since the synthetic training dataset they generated covers a wide range of face poses. The proposed method is validated with three datasets including a synthetic facial depth data set, a real Kinect V2 facial depth data set and Middlebury Stereo Data set. Experimental results show that it outperforms the state‐of‐the‐art methods on all the three data sets.
Optimised hybrid classifiers for automatic HEp‐2 cell classification
Authors: Chariyamparambil Chandran Manju , Victor Jose Marianthiran
Published: February 2021

This paper introduces a new HEp‐2 cell classification model under two phases. In the initial phase, the input image is segmented using the morphological operations (opening and closing), and the segmented image is given for Convolutional Neural Network (CNN) classifier that gives the classified output. In the second phase, the given input is processed under (i) segmentation process (ii) Feature Extraction, and (iii) Classification. From the segmented images; the features like Gray level co‐occurrence Matrix TGLCM) and Gray level Run Length Matrix (GLRM) are extracted. After extracting the features, they are subjected to a classification process, where Neural Network (NN) is used. Finally, the mean of both classified output (first phase and second phase) is considered to be the final classified output. As the main contribution, to enhance the classification accuracy, the hidden neurons of both classifiers (CNN and NN) are optimally chosen during the classification process. To make this possible, this paper aims to propose a new Randomized Update based Grey Wolf Optimization (RP‐GWO) algorithm. Finally, the performance of the implemented approach is compared over other conventional approaches and its superiority is proven with respect to certain measures.
Multi‐scale supervised network for crowd counting
Authors: Wang Yongjie , Zhang Wei , Huang Dongxiao , Liu Yanyan , Zhu Jianghua
Published: February 2021

Crowd counting is getting more and more attention in our daily life, because it can effectively prevent some safety problems. However, due to scale variations and background noise in the image, such as buildings and trees, getting the accurate number from image is a hard work. In order to address these problems, this work introduces a new multi‐scale supervised network. The proposed model uses part of vgg16 model as the backbone to extract feature. In the training process, a multi‐scale dilated convolution module is added at the end of each stage of the backbone network to generate attention map with different resolutions to help the model focus on the head area in feature map. In addition, the dilated convolution adopts three dilation ratios to fit different sizes of head in the image. Finally, in order to get the high‐quality density map with high‐resolution, the authors employ the upsampling operation to restore the density map size to the quarter size of original image. A large number of experiments on these four datasets show that the proposed network has greatly improved the counting accuracy of many existing methods.
Two‐scale fusion method of infrared and visible images via parallel saliency features
Authors: Duan Chaowei , Xing Changda , Lu Shanshan , Wang Zhisheng
Published: February 2021

An efficient fusion method of infrared and visible images is proposed based on the parallel saliency features. The method integrates significant feature information from the source images of multiple imaging modalities into a single fused image in a multi‐scale domain, while suppressing visual artefacts and retaining more detail and texture information. First, the input images are decomposed into two‐scale image representations, namely the base and detail layers, using a Gaussian filter. Second, the parallel saliency features of the high contrast and detail textures are captured to acquire the saliency maps. The contrast saliency weight map of the base layers based on the weighted local intensity energy aims to highlight the salient targets in infrared images and preserve the high‐intensity regions in visible images, while the detail saliency weight map of the detail layers using the structure tensor to extract the detail texture information. Finally, the final image is reconstructed by the fused base and detail layers. Sufficient experimental results convincingly demonstrate that the presented method can achieve a comparable or superior performance compared with several state‐of‐the‐art fusion methods via subjective assessments and objective evaluations, and it is more suitable for the practical applications due to the high computing efficiency.
A highly non-Keplerian protoplanetary disc
Authors: Wölfer L. , Facchini S. , Kurtovic N. T. , Teague R. , van Dishoeck E. F. , Benisty M. , Ercolano B. , Lodato G. , Miotello A. , Rosotti G. , Testi L. , Ubeira Gabellini M. G.
Published: February 2021

Context. In recent years high-angular-resolution observations have revealed that circumstellar discs appear in a variety of shapes with diverse substructures being ubiquitous. This has given rise to the question of whether these substructures are triggered by planet–disc interactions. Besides direct imaging, one of the most promising methods to distinguish between different disc-shaping mechanisms is to study the kinematics of the gas disc. In particular, the deviations of the rotation profile from Keplerian velocity can be used to probe perturbations in the gas pressure profile that may be caused by embedded (proto-) planets.

Aims. In this paper we aim to analyse the gas brightness temperature and kinematics of the transitional disc around the intermediate-mass star CQ Tau in order to resolve and characterise substructure in the gas caused by possible perturbers.

Methods. For our analysis we used spatially resolved ALMA observations of the three CO isotopologues 12CO, 13CO, and C18O (J = 2−1) from the disc around CQ Tau. We further extracted robust line centroids for each channel map and fitted a number of Keplerian disc models to the velocity field.

Results. The gas kinematics of the CQ Tau disc present non-Keplerian features, showing bent and twisted iso-velocity curves in 12CO and 13CO. Significant spiral structures are detected between ~10 and 180 au in both the brightness temperature and the rotation velocity of 12CO after subtraction of an azimuthally symmetric model, which may be tracing planet–disc interactions with an embedded planet or low-mass companion. We identify three spirals, two in the brightness temperature and one in the velocity residuals, spanning a large azimuth and radial extent. The brightness temperature spirals are morphologically connected to spirals observed in near-infrared scattered light in the same disc, indicating a common origin. Together with the observed large dust and gas cavity, these spiral structures support the hypothesis of a massive embedded companion in the CQ Tau disc.
Expression of TIGIT in splenic and circulatory T cells from mice acutely infected with Toxoplasma gondii
Authors: Wang Shuai , Li Haoran , Zhang Fuqiang , Jiao Yuankai , Xie Qing , Zhang Zhenchao , Li Xiangrui
Published: February 2021

The surface protein TIGIT (T cell immunoglobulin and immunoreceptor tyrosine-based inhibitory motif (ITIM) domain) has been characterized as an important regulator of cell-mediated immune responses in various infections. However, TIGIT expression in immune cells of mice infected with Toxoplasma gondii has not been investigated. Here, we detected TIGIT expression and related phenotypes by flow cytometry and real-time PCR in splenic and circulatory T cells of mice infected with the T. gondii RH strain. We found that the expression of TIGIT on the surface of CD4+ T cells and CD8+ T cells from the spleen and peripheral blood mononuclear cells decreased in the early stage, but increased significantly in the late stage of acute T. gondii infection in mice. Importantly, TIGIT expression was positively correlated with lesions in the murine spleen. In addition, T. gondii-specific TIGIT+TCM cells in the spleen were activated and transformed into TIGIT+ TEM cells. Hematoxylin and eosin staining of spleen sections and real-time PCR showed that the severity of splenic lesions was positively correlated with the T. gondii load. This study demonstrates that acute T. gondii infection can regulate the expression of TIGIT in T cells and affect immune cell function.
N-Acylbenzotriazoles as Proficient Substrates for an Easy Access to Ureas, Acylureas, Carbamates, and Thiocarbamates via Curtius Rearrangement Using Diphenylphosphoryl Azide (DPPA) as Azide Donor
Authors: Tiwari Vinod K. , Yadav Mangal S. , Singh Sumt K. , Agrahari Anand K. , Singh Anoop S.
Published: February 2021

A diverse range of ureas, N-acylureas, carbamates, and thiocarbamates has been synthesized in good to excellent yields by reacting N-acylbenzotriazoles individually with amines or amides or phenols or thiols in the presence of diphenylphosphoryl azide (DPPA) as a suitable azide donor in anhydrous toluene at 110 °C for 3–4 hours. In this route, DPPA was found to be a good alternative to trimethylsilyl azide and sodium azide for the azide donor in Curtius degradation. The high reaction yields, one-pot and metal-free conditions, straightforward nature, easy handling, use of readily available reagents, and in many cases avoidance of column chromatography are the notable features of the devised protocol.