bluuebunny/crossref_metadata_2025 huggingface dataset:
Two‐Dimensional Full‐Wave Simulation of Whistler Mode Wave Propagation Near the Local Lower Hybrid Resonance Frequency in a Dipole Field
Authors: Xu Xiang , Chen Lunjin , Zhou Chen , Liu Xu , Xia Zhiyang , Simpson Jamesina J. , Zhang Yuannong
Published: March 2020

We investigate the propagation of whistler mode waves near the local lower hybrid resonance (LHR) frequency in a dipole field with a two‐dimensional full‐wave model. First, we run a simulation in which a parallel whistler with frequency above the local LHR frequency is launched at the equatorial region in electron plasma. We find that whistler emission propagates along the dipole field line to a high latitude, turns quasi‐electrostatic where the wave frequency is close to the local LHR frequency, and continues to propagate until being absorbed. Then, the proton response is considered. We find that (1) a quasi‐electrostatic whistler reflects where the wave frequency is below the local LHR frequency and propagates to a larger L‐shell and lower latitude, (2) a strong standing‐wave pattern is formed in the LHR reflection region, and (3) the whistler emission turns from right‐hand circularly polarized to linearly polarized near the reflection region. Finally, we run a simulation in which a quasi‐electrostatic whistler is launched at a high latitude with a small‐scale density irregularity added as a depletion to the background plasma. We find that a small portion of quasi‐electrostatic whistler energy can be coupled to a parallel whistler, which can propagate to a much lower altitude while most of the wave energy experiences LHR reflection. Moreover, the mode coupling depends on the transverse and longitudinal sizes of the density irregularity. This makes a possible explanation of ground observations of nonducted whistler emission, which could have been reflected in the high‐latitude ionosphere and magnetosphere.
A DRP‐4DVar‐Based Coupled Data Assimilation System With a Simplified Off‐Line Localization Technique for Decadal Predictions
Authors: He Yujun , Wang Bin , Liu Li , Huang Wenyu , Xu Shiming , Liu Juanjuan , Wang Yong , Li Lijuan , Huang Xiaomeng , Peng Yiran , Lin Yanluan , Yu Yongqiang
Published: March 2020

A new weakly coupled data assimilation (CDA) system based on the dimension‐reduced projection four‐dimensional variational data assimilation (DRP‐4DVar) with a simplified off‐line localization technique and a fully coupled model, i.e., the Grid‐point Version 2 of Flexible Global Ocean‐Atmosphere‐Land System Model (FGOALS‐g2), was developed for the initialization of decadal predictions. A 1‐month assimilation window was adopted for the CDA system, in which monthly mean temperature and salinity analyses were assimilated along the trajectory of the coupled model during the initialization for the period of 1945–2006. The system is efficient because the 62‐year initialization only takes about 2.375 times of the time cost of the uninitialized run for the same period. Compared with the uninitialized simulation and the initialization without localization, ocean temperature and salinity, sea surface elevation, surface air temperature, and precipitation are in better agreement with the verification data. Furthermore, climate variabilities in the Pacific and Atlantic regions such as El Niño‐Southern Oscillation, Pacific Decadal Oscillation (PDO), and Atlantic Multidecadal Oscillation (AMO) are more realistically captured. Starting from the initial conditions (ICs) generated by the initialization, 10‐member ensemble decadal prediction experiments were conducted each year from 1961 to 1996. The results demonstrate that higher decadal prediction skills of surface air temperature anomalies averaged over the globe, ocean, land, and the North Pacific subpolar gyre are achieved than those obtained from persistence, the uninitialized simulation, and the prediction initialized from the ICs without localization. Besides, PDO and AMO indices exhibit significant correlation skills in most lead times.
Assessment of Climate, Sizing, and Location Controls on Green Infrastructure Efficacy: A Timescale Framework
Authors: Hung F. , Harman C. J. , Hobbs B. F. , Sivapalan M.
Published: March 2020

We investigate how the effectiveness of green infrastructure (GI) to mitigate the frequency and magnitude of significant discharge events and combined sewer overflows (CSOs) depend on both climate and sewershed characteristics and propose a theoretical framework for a holistic assessment of GI's efficacy. The framework is based on the comparison of three characteristic timescales that control the production of peak discharge: rainfall duration (tr), travel time in the sewer network (tn), and the duration of rain that would be required to fill the GI's storage (tGI). Storm events can then be characterized by two ratios of these timescales: Tn = tn/tGI and Tr = tr/tGI. A third dimensionless number characterizes critical storms during which adverse events (such as CSOs) occur and allows us to identify the combinations of Tn and Tr for which GI may substantially mitigate those events. The results of numerical experiments with the model demonstrate that the storms for which GI can substantially reduce peak discharge and CSO volume typically occur in a narrow band of Tn and Tr. Within that band, the efficacy of GI may depend on the location of GI within the sewershed if network routing substantially affects the timing and magnitude of flood peaks. The proposed framework is applied to examine the efficacy of GI using historical precipitation data from two major U.S. cities: Philadelphia, PA, and Seattle, WA, and the results of this comparative analysis suggest that GI location is an important control on catchment‐scale GI efficacy in Philadelphia, but less so in Seattle.
New Analytical Models for Flow Induced by Pumping in a Stream‐Aquifer System: A New Robin Boundary Condition Reflecting Joint Effect of Streambed Width and Storage
Authors: Huang Ching‐Sheng , Wang Zicheng , Lin Ye‐Chen , Yeh Hund‐Der , Yang Tao
Published: March 2020

A Robin type boundary condition (BC), commonly adopted at stream‐aquifer interface, excludes a term associated with streambed accounting for the effects of streambed storage and width. This study presents two new analytical models for describing confined flow induced by pumping in a stream‐aquifer system. One model considers a single‐zone aquifer and treats the streambed as a lagging Robin BC with a time lag parameter related to the effects. The other considers a two‐zone aquifer consisting of aquifer and streambed zones. A Dirichlet BC for stream water level is specified at the edge of the streambed. The time‐domain solutions of both models are developed to describe spatiotemporal drawdown and temporal stream filtration/depletion rate (SDR). The finite element solutions (FESs) of both models are also built. Results suggest the lag time equals the half of the squared streambed width divided by the streambed hydraulic diffusivity. The effects of streambed width and storage on SDR should be considered when their lumped parameter exceeds 0.1. Neglecting their effects causes 25% difference in SDR when the lumped parameter equals 10. Based on the FESs, the use of the lagging Robin BC takes nearly a tenth of computing time of obtaining accurate steady‐state SDR for the simulation of the two‐zone aquifer. In addition, the present solutions agree to a field SDR experiment conducted by Hunt et al. (2001, https://doi.org/10.1111/j.1745‐6584.2001.tb02310.x). To conclude, this study presents two new models for describing groundwater flow in a stream‐aquifer system and explores the joint effect of streambed width and storage on SDR.
The Polar Wind Modulated by the Spatial Inhomogeneity of the Strength of the Earth's Magnetic Field
Authors: Li Kun , Förster Matthias , Rong Zhaojin , Haaland Stein , Kronberg Elena , Cui Jun , Chai Lihui , Wei Yong
Published: March 2020

When the geomagnetic field is weak, the small mirror force allows precipitating charged particles to deposit energy in the ionosphere. This leads to an increase in ionospheric outflow from the Earth's polar cap region, but such an effect has not been previously observed because the energies of the ions of the polar ionospheric outflow are too low, making it difficult to detect the low‐energy ions with a positively charged spacecraft. In this study, we found an anticorrelation between ionospheric outflow and the strength of the Earth's magnetic field. Our results suggest that the electron precipitation through the polar rain can be a main energy source of the polar wind during periods of high levels of solar activity. The decreased magnetic field due to spatial inhomogeneity of the Earth's magnetic field and its effect on outflow can be used to study the outflow in history when the magnetic field was at similar levels.
State-of-the-art neonatal cerebral ultrasound: technique and reporting
Authors:   eurUS.brain group, Dudink Jeroen , Jeanne Steggerda Sylke , Horsch Sandra
Published: March 2020

In the past three decades, cerebral ultrasound (CUS) has become a trusted technique to study the neonatal brain. It is a relatively cheap, non-invasive, bedside neuroimaging method available in nearly every hospital. Traditionally, CUS was used to detect major abnormalities, such as intraventricular hemorrhage (IVH), periventricular hemorrhagic infarction, post-hemorrhagic ventricular dilatation, and (cystic) periventricular leukomalacia (cPVL). The use of different acoustic windows, such as the mastoid and posterior fontanel, and ongoing technological developments, allows for recognizing other lesion patterns (e.g., cerebellar hemorrhage, perforator stroke, developmental venous anomaly). The CUS technique is still being improved with the use of higher transducer frequencies (7.5–18 MHz), 3D applications, advances in vascular imaging (e.g. ultrafast plane wave imaging), and improved B-mode image processing. Nevertheless, the helpfulness of CUS still highly depends on observer skills, knowledge, and experience. In this special article, we discuss how to perform a dedicated state-of-the-art neonatal CUS, and we provide suggestions for structured reporting and quality assessment.
Urban vacant lands impart hydrological benefits across city landscapes
Authors: Kelleher Christa , Golden Heather E. , Burkholder Sean , Shuster William
Published: March 2020

Cities evolve through phases of construction, demolition, vacancy, and redevelopment, each impacting water movement at the land surface by altering soil hydrologic properties, land cover, and topography. Currently unknown is whether the variable physical and vegetative characteristics associated with vacant parcels and introduced by demolition may absorb rainfall and thereby diminish stormwater runoff. To investigate this, we evaluate how vacant lots modulate citywide hydrologic partitioning by synthesizing a novel field dataset across 500+ parcels in Buffalo, New York, USA. Vacant lot infiltration rates vary widely (0.001 to 5.39 cm h−1), though parcels are generally well-vegetated and gently sloped. Extending field estimates to 2400 vacant parcels, we estimate that vacant lands citywide may cumulatively infiltrate 51–54% additional annual rainfall volume as compared to pre-demolition state, in part by reducing and disconnecting impervious areas. Our findings differentiate vacant lots as purposeful landscapes that can alleviate large water fluxes into aging wastewater infrastructure.
Electroosmotically generated disinfectant from urine as a by-product of electricity in microbial fuel cell for the inactivation of pathogenic species
Authors: Gajda Iwona , Obata Oluwatosin , Greenman John , Ieropoulos Ioannis A.
Published: March 2020

This work presents a small scale and low cost ceramic based microbial fuel cell, utilising human urine into electricity, while producing clean catholyte into an initially empty cathode chamber through the process of electro-osmostic drag. It is the first time that the catholyte obtained as a by-product of electricity generation from urine was transparent in colour and reached pH>13 with high ionic conductivity values. The catholyte was collected and used ex situ as a killing agent for the inactivation of a pathogenic species such as Salmonella typhimurium, using a luminometer assay. Results showed that the catholyte solutions were efficacious in the inactivation of the pathogen organism even when diluted up to 1:10, resulting in more than 5 log-fold reduction in 4 min. Long-term impact of the catholyte on the pathogen killing was evaluated by plating Salmonella typhimurium on agar plates and showed that the catholyte possesses a long-term killing efficacy and continued to inhibit pathogen growth for 10 days.
New Dromaeosaurid Dinosaur (Theropoda, Dromaeosauridae) from New Mexico and Biodiversity of Dromaeosaurids at the end of the Cretaceous
Authors: Jasinski Steven E. , Sullivan Robert M. , Dodson Peter
Published: March 2020

Dromaeosaurids (Theropoda: Dromaeosauridae), a group of dynamic, swift predators, have a sparse fossil record, particularly at the time of their extinction near the Cretaceous-Paleogene boundary. Here we report on a new dromaeosaurid, Dineobellator notohesperus, gen. and sp. nov., consisting of a partial skeleton from the Upper Cretaceous (Maastrichtian) of New Mexico, the first diagnostic dromaeosaurid to be recovered from the latest Cretaceous of the southern United States (southern Laramidia). The holotype includes elements of the skull, axial, and appendicular skeleton. The specimen reveals a host of morphologies that shed light on new behavioral attributes for these feathered dinosaurs. Unique features on its forelimbs suggest greater strength capabilities in flexion than the normal dromaeosaurid condition, in conjunction with a relatively tighter grip strength in the manual claws. Aspects of the caudal vertebrae suggest greater movement near the tail base, aiding in agility and predation. Phylogenetic analysis places Dineobellator within Velociraptorinae. Its phylogenetic position, along with that of other Maastrichtian taxa (Acheroraptor and Dakotaraptor), suggests dromaeosaurids were still diversifying at the end of the Cretaceous. Furthermore, its recovery as a second North American Maastrichtian velociraptorine suggests vicariance of North American velociraptorines after a dispersal event during the Campanian-Maastrichtian from Asia. Features of Dineobellator also imply that dromaeosaurids were active predators that occupied discrete ecological niches while living in the shadow of Tyrannosaurus rex, until the end of the dinosaurs’ reign.
Effect of Thomas Rotation on the Lorentz Transformation of Electromagnetic fields
Authors: Malhotra Lakshya , Golub Robert , Kraegeloh Eva , Nouri Nima , Plaster Bradley
Published: March 2020

A relativistic particle undergoing successive boosts which are non collinear will experience a rotation of its coordinate axes with respect to the boosted frame. This rotation of coordinate axes is caused by a relativistic phenomenon called Thomas Rotation. We assess the importance of Thomas rotation in the calculation of physical quantities like electromagnetic fields in the relativistic regime. We calculate the electromagnetic field tensor for general three dimensional successive boosts in the particle’s rest frame as well as the laboratory frame. We then compare the electromagnetic field tensors obtained by a direct boost $$\overrightarrow{\beta }+\delta \overrightarrow{\beta }$$β→+δβ→ and successive boosts $$\overrightarrow{\beta }$$β→ and $$\Delta \overrightarrow{\beta }$$Δβ→ and check their consistency with Thomas rotation. This framework might be important to situations such as the calculation of frequency shifts for relativistic spin-1/2 particles undergoing Larmor precession in electromagnetic fields with small field non-uniformities.
Bipyrazone: a new HPPD-inhibiting herbicide in wheat
Authors: Wang Hengzhi , Liu Weitang , Jin Tao , Peng Xuegang , Zhang Lele , Wang Jinxin
Published: March 2020

Bipyrazone, 1,3-dimethyl-4-(2-(methylsulfonyl)-4-(trifluoromethyl) benzoyl)-1H-pyrazol-5-yl 1,3-dimethyl-1H-pyrazole- 4-carboxylate, is a 4-hydroxyphenylpyaunate dioxygenase (HPPD)-inhibiting herbicide. Greenhouse and field experiments were conducted to explore the potential of post-emergence (POST) application of bipyrazone in wheat fields in China. In the greenhouse study, bipyrazone at 10 and 20 g active ingredient (a.i.) ha−1 effectively controlled Descurainia sophia L., Capsella bursa-pastoris (L.) Medic., Lithospermum arvense L. and Myosoton aquaticum L. Whereas, all tested 16 wheat cultivars showed high degree of tolerance to bipyrazone at 375 and 750 g a.i. ha−1. In a dose-response experiment carried on the Shannong 6 wheat cultivar and five weed biotypes, bipyrazone was safe to the wheat cultivar, and C. bursa-pastoris, M. aquaticum and D. sophia were sensitive to this herbicide. The selectivity index (SI) between the Shannong 6 and weeds ranged from 34 to 39. The field experiments confirmed that a mixture of bipyrazone and fluroxypyr-mepthyl is practical for controlling broadleaf weeds, and bipyrazone applied alone at 30 to 40 g a.i. ha−1 can also provide satisfactory control of sensitive broadleaf weeds. These findings suggest that bipyrazone POST application has good potential for broadleaf weed management in wheat fields.
Obestatin and growth hormone reveal the interaction of central obesity and other cardiometabolic risk factors of metabolic syndrome
Authors: Yu Angus P. , Ugwu Felix N. , Tam Bjorn T. , Lee Paul H. , Ma Vicki , Pang Simon , Chow Angel S. , Cheng Kenneth K. , Lai Christopher W. , Wong Cesar S. , Siu Parco M.
Published: March 2020

Metabolic syndrome (MetS) is a multi-factorial disorder including central obesity (CO), insulin resistance, hyperglycemia, dyslipidemia and hypertension which increases the risk of diabetes mellitus and cardiovascular diseases. CO is considered as an essential component of MetS according to International Diabetes Federation (IDF), which may further modulate distinct signalling pathways compared with the other four MetS risk factors. Given that ghrelin signalling and the growth hormone/insulin-like growth factor-1 (GH/IGF-1) axis regulates energy balance and metabolic homeostasis, this study examined the changes in various ghrelin products and circulating hormones in response to the interaction between CO and other MetS components including blood pressure, fasting blood glucose, triglycerides, and high-density lipoprotein cholesterol in 133 Hong Kong Chinese adults. Circulating obestatin and GH were increased and reduced, respectively, by either CO or the other 4-risk factor cluster. These changes were further augmented by the presence of all MetS risk factors. However, changes of ghrelin levels were not mediated by CO but the other MetS risk factors. Our findings suggest that CO does not predict all the dysregulation of signalling pathways in individuals with MetS. Although CO and other MetS may share common signalling targets (i.e., obestatin and GH), CO does not contribute to the perturbation of ghrelin signalling.
Shear Induced Interactions Cause Polymer Compression
Authors: Dunstan Dave E. , Harvie Dalton J. E.
Published: March 2020

Shear induced particle pressure occurs in concentrated suspensions of particles. Importantly, the significance of the shear induced particle pressure has not been recognized in polymer rheology. The shear induced particle pressure results in an inward pressure on the polymer chains resulting in a shear dependent compressive force. The analytical form of the force balance equations that incorporate the effect of shear induced particle pressure predict a reduced polymer blob size and reducing viscosity with increasing shear rate as has been observed experimentally. Power law behavior is found for the viscosity in accord with the general observations for concentrated polymer rheology.
Evaluating the potential of hyperpolarised [1-13C] L-lactate as a neuroprotectant metabolic biosensor for stroke
Authors: Hyacinthe Jean-Noël , Buscemi Lara , Lê Thanh Phong , Lepore Mario , Hirt Lorenz , Mishkovsky Mor
Published: March 2020

Cerebral metabolism, which can be monitored by magnetic resonance spectroscopy (MRS), changes rapidly after brain ischaemic injury. Hyperpolarisation techniques boost 13C MRS sensitivity by several orders of magnitude, thereby enabling in vivo monitoring of biochemical transformations of hyperpolarised (HP) 13C-labelled precursors with a time resolution of seconds. The exogenous administration of the metabolite L-lactate was shown to decrease lesion size and ameliorate neurological outcome in preclinical studies in rodent stroke models, as well as influencing brain metabolism in clinical pilot studies of acute brain injury patients. The aim of this study was to demonstrate the feasibility of measuring HP [1-13C] L-lactate metabolism in real-time in the mouse brain after ischaemic stroke when administered after reperfusion at a therapeutic dose. We showed a rapid, time-after-reperfusion-dependent conversion of [1-13C] L-lactate to [1-13C] pyruvate and [13C] bicarbonate that brings new insights into the neuroprotection mechanism of L-lactate. Moreover, this study paves the way for the use of HP [1-13C] L-lactate as a sensitive molecular-imaging biosensor in ischaemic stroke patients after endovascular clot removal.
Relative posture between head and finger determines perceived tactile direction of motion
Authors: Chen Yueh-Peng , Yeh Chun-I , Lee Tsung-Chi , Huang Jian-Jia , Pei Yu-Cheng
Published: March 2020

The hand explores the environment for obtaining tactile information that can be fruitfully integrated with other functions, such as vision, audition, and movement. In theory, somatosensory signals gathered by the hand are accurately mapped in the world-centered (allocentric) reference frame such that the multi-modal information signals, whether visual-tactile or motor-tactile, are perfectly aligned. However, an accumulating body of evidence indicates that the perceived tactile orientation or direction is inaccurate; yielding a surprisingly large perceptual bias. To investigate such perceptual bias, this study presented tactile motion stimuli to healthy adult participants in a variety of finger and head postures, and requested the participants to report the perceived direction of motion mapped on a video screen placed on the frontoparallel plane in front of the eyes. Experimental results showed that the perceptual bias could be divided into systematic and nonsystematic biases. Systematic bias, defined as the mean difference between the perceived and veridical directions, correlated linearly with the relative posture between the finger and the head. By contrast, nonsystematic bias, defined as minor difference in bias for different stimulus directions, was highly individualized, phase-locked to stimulus orientation presented on the skin. Overall, the present findings on systematic bias indicate that the transformation bias among the reference frames is dominated by the finger-to-head posture. Moreover, the highly individualized nature of nonsystematic bias reflects how information is obtained by the orientation-selective units in the S1 cortex.
The effect of phylogeographic history on species boundaries: a comparative framework in Hyla tree frogs
Authors: Dufresnes Christophe , Berroneau Matthieu , Dubey Sylvain , Litvinchuk Spartak N. , Perrin Nicolas
Published: March 2020

Because it is indicative of reproductive isolation, the amount of genetic introgression across secondary contact zones is increasingly considered in species delimitation. However, patterns of admixture at range margins can be skewed by the regional dynamics of hybrid zones. In this context, we posit an important role for phylogeographic history: hybrid zones located within glacial refugia (putatively formed during the Late-Pleistocene) should be better defined than those located in post-glacial or introduced ranges (putatively formed during the Holocene and the Anthropocene). We test this hypothesis in a speciation continuum of tree frogs from the Western Palearctic (Hyla), featuring ten identified contacts between species spanning Plio-Pleistocene to Miocene divergences. We review the rich phylogeographic literature of this group and examine the overlooked transition betweenH. arboreaandH. molleriin Western France using a multilocus dataset. Our comparative analysis supports a trend that contacts zones resulting from post-glacial expansions and human translocations feature more extensive introgression than those established within refugial areas. Integrating the biogeographic history of incipient species, i.e. their age since first contact together with their genetic divergence, thus appears timely to draw sound evolutionary and taxonomic inferences from patterns of introgression across hybrid zones.
The Lake Chad hydrology under current climate change
Authors: Pham-Duc Binh , Sylvestre Florence , Papa Fabrice , Frappart Frédéric , Bouchez Camille , Crétaux Jean-Francois
Published: March 2020

Lake Chad, in the Sahelian zone of west-central Africa, provides food and water to ~50 million people and supports unique ecosystems and biodiversity. In the past decades, it became a symbol of current climate change, held up by its dramatic shrinkage in the 1980s. Despites a partial recovery in response to increased Sahelian precipitation in the 1990s, Lake Chad is still facing major threats and its contemporary variability under climate change remains highly uncertain. Here, using a new multi-satellite approach, we show that Lake Chad extent has remained stable during the last two decades, despite a slight decrease of its northern pool. Moreover, since the 2000s, groundwater, which contributes to ~70% of Lake Chad’s annual water storage change, is increasing due to water supply provided by its two main tributaries. Our results indicate that in tandem with groundwater and tropical origin of water supply, over the last two decades, Lake Chad is not shrinking and recovers seasonally its surface water extent and volume. This study provides a robust regional understanding of current hydrology and changes in the Lake Chad region, giving a basis for developing future climate adaptation strategies.
Systematic sequence analysis of the FUT3 gene identifies 11 novel alleles in the Sindhi and Punjabi populations from Pakistan
Authors: Zhao Maomao , Adnan Atif , Rakha Allah , Nazir Shahid , Tian Meihui , Zhang Siyi , Pang Hao
Published: March 2020

The FUT3 (Lewis) gene is responsible for the expression of Lewis fucosyltransferase, which is required for the synthesis of the structural determinants of both Lewisa and Lewisb specificity. These factors play an important role not only in clinical but also in medico-legal investigations. The gene sequence is highly polymorphic and ethnically specific. In the current study, we performed systematic sequence analysis of the coding region of FUT3 by DNA sequencing to investigate the genetic variations of FUT3 and the molecular basis of the Lewis phenotype in the Sindhi and Punjabi populations of Pakistan. Twenty-three point mutations were observed, including 7 unreported mutations, among which two missense mutations (490 G > A and 959 T > C) were predicted to be deleterious to enzyme activity by software assessment. In total, we observed 24 Lewis alleles, including 11 novel ones. However, all unreported missense mutations were present in Lewis-negative alleles confirmed previously. According to genotypic data, the Lewis-negative phenotypic frequencies were 11.5% and 22.93% in the Sindhi and Punjabi ethnic groups, respectively. Moreover, we found that le202,314 and le59,1067 were predominant among Lewis-negative alleles, while the frequency of le59,1067 in the Punjabi population was significantly higher than that in the Sindhi population. In summary, our study revealed that there is a relatively high degree of sequence variation of the Lewis gene in Pakistani populations and provided the first genetic data on FUT3 in these two ethnic groups from Pakistan. The allele types and their frequencies showed that these ethnic groups exhibit more Caucasian components.
Stochastic Resonance in Insulator-Metal-Transition Systems
Authors: Bhar Bitan , Khanna Abhishek , Parihar Abhinav , Datta Suman , Raychowdhury Arijit
Published: March 2020

Stochastic resonance (SR) is an ingenious phenomenon observed in nature and in biological systems but has seen very few practical applications in engineering. It has been observed and analyzed in widely different natural phenomenon including in bio-organisms (e.g. Mechanoreceptor of crayfish) and in environmental sciences (e.g. the periodic occurrence of ice ages). The main idea behind SR seems quite unorthodox – it proposes that noise, that is intrinsically present in a system or is extrinsically added, can help enhance the signal power at the output, in a desired frequency range. Despite its promise and ubiquitous presence in nature, SR has not been successively harnessed in engineering applications. In this work, we demonstrate both experimentally as well as theoretically how the intrinsic threshold noise of an insulator-metal-transition (IMT) material can enable SR. We borrow inspiration from natural systems which use SR to detect and amplify low-amplitude signals, to demonstrate how a simple electrical circuit which uses an IMT device can exploit SR in engineering applications. We explore two such applications: one of them utilizes noise to correctly transmit signals corresponding to different vowel sounds akin to auditory nerves, without amplifying the amplitude of the input audio sound. This finds applications in cochlear implants where ultra-low power consumption is a primary requirement. The second application leverages the frequency response of SR, where the loss of resonance at out-of-band frequencies is used. We demonstrate how to provide frequency selectivity by tuning an extrinsically added noise to the system.
A multistimuli responsive heteroleptic iridium(iii) complex: role of hydrogen bonding in probing solvent, pH and bovine serum albumin (BSA)
Authors: Kachwal Vishal , Sharma Parva Kumar , Sarmah Amrit , Chowdhury Shibasish , Laskar Inamur Rahaman
Published: March 2020

This article focuses on the vital role of hydrogen bonding to explain unusual photophysical behaviours (sensing BSA, pH probing, specific solvent effect) of an ‘Aggregation-induced Emission’ (AIE) active Ir(iii) complex.
Facile synthesis of porous Co3O4nanoflakes as an interlayer for high performance lithium–sulfur batteries
Authors: Zheng Xiao-Xiao , Zhao Shi-Xi , Yang Jin-Lin , Lu Yi-Ming , Wu Qi-Long , Zeng Xiang-Tian
Published: March 2020

Co3O4nanoflakes were fabricated using oil bath and calcination methods. Lithium–sulfur batteries with Co3O4–super P interlayer exhibited better performance attributed to the synergistic effects of Co3O4–super P.
An experimental and theoretical study of the coordination and donor properties of tris-2-pyridyl-phosphine ligands
Authors: Hanf Schirin , Colebatch Annie L. , Stehr Philipp , García-Rodríguez Raúl , Hey-Hawkins Evamarie , Wright Dominic S.
Published: March 2020

The donor properties of a range of multidentate 2-pyridyl-phosphines were evaluated using different experimental and computational methods.
Two-stage evolution from phosphate to sulfate of new KTP-type family members as UV nonlinear optical materials through chemical cosubstitution-oriented design
Authors: He Fangfang , Ge Yuwei , Zhao Xiaoyu , He Jing , Huang Ling , Gao Daojiang , Bi Jian , Wang Xin , Zou Guohong
Published: March 2020

New KTP-type antimony(iii)-based NLO materials with sharply enlarged bandgaps were developed through two-stage evolution from phosphate to sulfate.
Highly polarization-sensitive far infrared detector based on an optical antenna integrated aligned carbon nanotube film
Authors: Chen Binkai , Ji Zhaoyu , Zhou Jing , Yu Yu , Dai Xu , Lan Mengke , Bu Yonghao , Zhu Tianyun , Li Zhifeng , Hao Jiaming , Chen Xiaoshuang
Published: March 2020

The optical antenna integrated aligned carbon nanotube film works as a highly polarization-sensitive far infrared detector with a polarization extinction ratio over 13 600.
Facile synthesis of core–shell structured Si@graphene balls as a high-performance anode for lithium-ion batteries
Authors: Jamaluddin Anif , Umesh Bharath , Chen Fuming , Chang Jeng-Kuei , Su Ching-Yuan
Published: March 2020

Encapsulating silicon (Si) nanoparticles with graphene nanosheets in a microspherical structure is proposed to increase electrical conductivity and solve stability issues when using Si as an anode material in lithium-ion batteries (LIBs).
Photochemical rearrangement of diarylethenes: synthesis of functionalized phenanthrenes
Authors: Zakharov A. V. , Yadykov A. V. , Lvov A. G. , Mitina E. A. , Shirinian V. Z.
Published: March 2020

The photocyclization of diarylethenes bearing naphthalene units was explored and a convenient protocol for the synthesis of functionalized phenanthrenes was proposed.
The influence of the electron transport layer on charge dynamics and trap-state properties in planar perovskite solar cells
Authors: Yu Man , Guo Yanru , Yuan Shuai , Zhao Jia-Shang , Qin Yujun , Ai Xi-Cheng
Published: March 2020

The underlying work mechanism of electron transport layers and their significant influence on photovoltaic performance are systematically studied.
Lactic-co-glycolic acid-coated methylene blue nanoparticles with enhanced antibacterial activity for efficient wound healing
Authors: Xu Xiaomu , Hu Yusheng , Zhang Li-peng , Liu Bo , Yang Yue , Tang Taya , Tian Jijing , Peng Kaisong , Liu Tianlong
Published: March 2020

Enhanced antibacterial effect of MPNPs through increased singlet oxygen generation as a result of decreased ACQ effect
Epitaxial synthesis of Ni–MoS2/Ti3C2Tx MXene heterostructures for hydrodesulfurization
Authors: Vinoba Mari , Navvamani R. , Al-Sheeha Hanadi
Published: March 2020

A facile and efficient method is adopted to intercalate promoter and few-layered MoS2 in Ti3C2Tx MXene for high hydrodesulfurization activity via an in situ thermal conversion process.
Poly(3,4-ethylenedioxyselenophene): effect of solvent and electrolyte on electrodeposition, optoelectronic and electrochromic properties
Authors: Yadav Preeti , Naqvi Sheerin , Patra Asit
Published: March 2020

In this article, we report the effect of electropolymerization conditions such as solvent and supporting electrolyte on the redox, optoelectronic and electrochromic properties of PEDOS.
A CO2/H2 fuel cell: reducing CO2 while generating electricity
Authors: Liu Yan , Li Yawei , Chen Yuanzhen , Qu Ting , Shu Chengyong , Yang Xiaodong , Zhu Haiyan , Guo Shengwu , Zhao Shengdun , Asefa Tewodros , Liu Yongning
Published: March 2020

We report an innovative CO2/H2 fuel cell that can convert CO2 into CH4 while generating electricity instead of consuming it.
Preparation and evaluation of osteogenic nano-MgO/PMMA bone cement for bone healing in a rat critical size calvarial defect
Authors: Li Cairong , Sun Jianqiao , Shi Keda , Long Jing , Li Long , Lai Yuxiao , Qin Ling
Published: March 2020

A series of bioactive nano-MgO/PMMA bone cements were prepared with very suitable handling and mechanical properties, good biocompatibility and osteogenic activityin vitro, excellent osteogenesis properties and bone-bonding strength in a rat critical size calvarial defect.
Single-crystal field-effect transistors based on a fused-ring electron acceptor with high ambipolar mobilities
Authors: Xiao Chengyi , Li Cheng , Liu Feng , Zhang Lei , Li Weiwei
Published: March 2020

A fused-ring electron acceptor Y6 was used to fabricate single-crystal organic field-effect transistors, providing high ambipolar mobilities.
Salivary cortisol concentrations in police officers – a cross-sectional study in Beijing, China
Authors: Zhang Yanxia , Liu Jie , Liu Yanqing , Lu Wei , Hou Ailian
Published: March 2020

Objective: We investigated the relationship between salivary cortisol level and the prevalence of depression 585 police officers working at the Police Departments of Beijing.

Method: Cross-sectional data were obtained from 585 Chinese police officers recruited from Beijing, China. Salivary cortisol was assayed using the chemiluminescence immunoassay. A multiple logistic regression analysis adjusted for potential confounders was used to assess independent associations between salivary cortisol level and depression.

Results: The median age of the included was 38 years (IQR, 29–45), 20.9% were female (n = 122). Finally, 15.6% (91/585; 95% CI: 12.6–18.5%) were considered to have depression. The median salivary cortisol level was significantly higher in police with depression than those police without depression [14.5(IQR, 11.9–15.9) nmol/l vs. 11.8(IQR, 9.4–14.2) nmol/l; P < 0.001]. The depression distribution across the salivary cortisol quartiles ranged between 5.4% (first quartile) and 26.9% (fourth quartile), P for trend <0.001. In multivariate models comparing the second (Q2), third and fourth quartiles against the first quartile of the salivary cortisol, cortisol in Q3 and Q4 were associated with depression, and increased prevalence of depression by 148% (OR: 2.48; 95% CI: 1.55–3.86) and 277% (3.77; 2.12–5.36). Based on ROC curves, the optimal cutoff value of salivary cortisol level to diagnose the depression was 13.8 nmol/l, which yielded the highest sensitivity and specificity [63.8% and 71.7%, respectively; area under the curve (AUC) = 0.695, 95% CI: 0.639–0.751; P < 0.0001].

Conclusions: The data showed that elevated levels of salivary cortisol were associated with increased prevalence of depression.
Serial Recall Predicts Vocoded Sentence Recognition Across Spectral Resolutions
Authors: Bosen Adam K. , Barry Michael F.
Published: March 2020

Purpose

The goal of this study was to determine how various aspects of cognition predict speech recognition ability across different levels of speech vocoding within a single group of listeners.

Method

We tested the ability of young adults (
N
= 32) with normal hearing to recognize Perceptually Robust English Sentence Test Open-set (PRESTO) sentences that were degraded with a vocoder to produce different levels of spectral resolution (16, eight, and four carrier channels). Participants also completed tests of cognition (fluid intelligence, short-term memory, and attention), which were used as predictors of sentence recognition. Sentence recognition was compared across vocoder conditions, predictors were correlated with individual differences in sentence recognition, and the relationships between predictors were characterized.

Results

PRESTO sentence recognition performance declined with a decreasing number of vocoder channels, with no evident floor or ceiling performance in any condition. Individual ability to recognize PRESTO sentences was consistent relative to the group across vocoder conditions. Short-term memory, as measured with serial recall, was a moderate predictor of sentence recognition (ρ = 0.65). Serial recall performance was constant across vocoder conditions when measured with a digit span task. Fluid intelligence was marginally correlated with serial recall, but not sentence recognition. Attentional measures had no discernible relationship to sentence recognition and a marginal relationship with serial recall.

Conclusions

Verbal serial recall is a substantial predictor of vocoded sentence recognition, and this predictive relationship is independent of spectral resolution. In populations that show variable speech recognition outcomes, such as listeners with cochlear implants, it should be possible to account for the independent effects of spectral resolution and verbal serial recall in their speech recognition ability.

Supplemental Material

https://doi.org/10.23641/asha.12021051
Laryngeal Manifestations of Autoimmune Diseases
Authors: Pierce Jenny L.
Published: March 2020

Purpose

This review article provides an overview of autoimmune diseases and their effects on voice and laryngeal function.

Method

A literature review was conducted in PubMed. Combinations of the following keywords were used: “autoimmune disease and upper airway,” “larynx,” “cough,” “voice,” “dysphonia,” and “dyspnea.” Precedence was given to articles published in the past 10 years due to recent advances in this area and to review articles. Ultimately, 115 articles were included for review.

Results

Approximately 81 autoimmune diseases exist, with 18 of those highlighted in the literature as having laryngeal involvement. The general and laryngeal manifestations of these 18 are discussed in detail, in addition to the clinical implications for a laryngeal expert.

Conclusions

Voice, breathing, and cough symptoms may be an indication of underlying autoimmune disease. However, these symptoms are often similar to those in the general population. Appropriate differential diagnosis and timely referral practices maximize patient outcomes. Guidelines are provided to facilitate correct diagnosis when an autoimmune disease is suspected.
Large step size electromagnetic transient simulations by matrix transformation‐based shifted‐frequency phasor models
Authors: Ye Xiaohui , Tang Yong , Shu Dewu
Published: March 2020

To evaluate and improve the performances of control and protection strategies for large‐scale AC grids, simulation models that can adopt a much larger time‐step, provide instantaneous and wide frequency‐band phasor values simultaneously are desirable. However, the traditional electromagnetic transient (EMT) model is numerically expensive and the transient stability (TS) model only preserves low‐frequency dynamics. To resolve these issues, the shifted frequency phasor (SFP) modelling is generalised based on specific matrix transformations and SFP models of typical components in large‐scale AC grids are derived hereafter. Unlike traditional models, the SFP models can produce instantaneous and wide frequency‐band phasor waveforms simultaneously, while the latter matches the envelopes of the former exactly. Moreover, the simulation efficiency is dramatically improved by adopting a much larger time‐step. The performance concerning the accuracy and efficiency is compared with the traditional EMT and TS models by simulating a practical large‐scale AC grid under different scenarios.
Infrared spectra of complex organic molecules in astronomically relevant ice mixtures
Authors: Rachid M. G. , Terwisscha van Scheltinga J. , Koletzki D. , Linnartz H.
Published: March 2020

Context. Complex organic molecules (COMs) have been largely identified through their characteristic rotational transitions in the gas of interstellar and circumstellar regions. Although these species are formed in the icy mantles that cover dust grains, the most complex species that has been unambiguously identified in the solid-phase to date is methanol (CH3OH). With the upcoming launch of the James Webb Space Telescope (JWST), this situation may change. The higher sensitivity, spectral and spatial resolution of the JWST will allow for the probing of the chemical inventory of ices in star-forming regions. In order to identify features of solid-state molecules in astronomical spectra, laboratory infrared spectra of COMs within astronomically relevant conditions are required. This paper is part of a series of laboratory studies focusing on the infrared spectra of frozen COMs embedded in ice matrices. These reflect the environmental conditions in which COMs are thought to be found.

Aims. This work is aimed at characterizing the infrared features of acetone mixed in ice matrices containing H2O, CO2, CO, CH4, and CH3OH for temperatures ranging between 15 K and 160 K. Changes in the band positions and shapes due to variations in the temperature, ice composition, and morphology are reported. This work also points out the IR features that are considered the best promising tracers when searching for interstellar acetone-containing ices.

Methods. Acetone-containing ices were grown at 15 K under high-vacuum conditions and infrared (IR) spectra (500–4000 cm−1/20–2.5 μm, 0.5 cm−1 resolution) in transmission mode were recorded using a Fourier transform infrared spectrometer. Spectra of the ices at higher temperatures are acquired during the heating of the sample (at a rate of 25 K h−1) up to 160 K. The changes in the infrared features for varying conditions were analyzed.

Results. A large set of IR spectra of acetone-containing ices is presented and made available as a basis for interpreting current and future infrared astronomical spectra. The peak position and full width at half maximum of selected acetone bands have been measured for different ice mixtures and temperatures. The bands that are best suitable for acetone identification in astronomical spectra are: the C=O stretch mode, around 1710.3 cm−1 (5.847 μm), that lies in the 1715–1695 cm−1 (5.83–5.90 μm) range in the mixed ices; the CH3 symmetric deformation, around 1363.4 cm−1 (7.335 μm) that lies in the 1353–1373 cm−1 (7.28–7.39 μm) range in the mixed ices; and the CCC asymmetric stretch, around 1228.4 cm−1 (8.141 μm), that lies in the 1224–1245 cm−1 (8.16–8.03 μm) range in the mixed ices. The CCC asymmetric stretch band also exhibits potential as a remote probe of the ice temperature and composition; this feature is the superposition of two components that respond differently to temperature and the presence of CH3OH. All the spectra are available through the Leiden Ice Database.
Physical properties of bright Ca II K fibrils in the solar chromosphere
Authors: Kianfar Sepideh , Leenaarts Jorrit , Danilovic Sanja , de la Cruz Rodríguez Jaime , José Díaz Baso Carlos
Published: March 2020

Context. Broad-band images of the solar chromosphere in the Ca II H&K line cores around active regions are covered with fine bright elongated structures called bright fibrils. The mechanisms that form these structures and cause them to appear bright are still unknown.

Aims. We aim to investigate the physical properties, such as temperature, line-of-sight velocity, and microturbulence, in the atmosphere that produces bright fibrils and to compare those to the properties of their surrounding atmosphere.

Methods. We used simultaneous observations of a plage region in Fe I 6301-2 Å, Ca II 8542 Å, Ca II K, and Hα acquired by the CRISP and CHROMIS instruments on the Swedish 1 m Solar Telescope. We manually selected a sample of 282 Ca II K bright fibrils. We compared the appearance of the fibrils in our sample to the Ca II 8542 Å and Hα data. We performed non-local thermodynamic equilibrium inversions using the inversion code STiC on the Fe I 6301-2 Å, Ca II 8542 Å, and Ca II K lines to infer the physical properties of the atmosphere.

Results. The line profiles in bright fibrils have a higher intensity in their K2 peaks compared to profiles formed in the surrounding atmosphere. The inversion results show that the atmosphere in fibrils is on average  −100 K hotter at an optical depth log(τ500 nm) = −4.3 compared to their surroundings. The line-of-sight velocity at chromospheric heights in the fibrils does not show any preference towards upflows or downflows. The microturbulence in the fibrils is on average 0.5 km s−1 higher compared to their surroundings. Our results suggest that the fibrils have a limited extent in height, and they should be viewed as hot threads pervading the chromosphere.
ICHTML 2020 – How learning technology wins coronavirus
Authors: Hamaniuk Vita , Semerikov Serhiy , Shramko Yaroslav
Published: March 2020

This is an introductory text to a collection of papers from the ICHTML 2020: The International Conference on History, Theory and Methodology of Learning, which held in Kryvyi Rih State Pedagogical University, Kryvyi Rih, Ukraine, on the May 13-15, 2020. It consists of short introduction, conference review and some observations about the event and its future.