bluuebunny/crossref_metadata_2025 huggingface dataset:
Significant Broadening of the Substrate Scope for the Hydrated Imidazoline Ring Expansion (HIRE) via the Use of Lithium Hexamethyldisilazide
Authors: Krasavin Mikhail , Grintsevich Sergey , Sapegin Alexander
Published: February 2022

Substrates that are insufficiently activated towards the hydrated imidazoline ring expansion (HIRE) process have been previously found to deliver exclusively the products of aminoalkyl side-chain ring expansion. Attempted reversal of the process by thermal activation towards HIRE failed. We have found that for such problematic substrates the HIRE-type ring expansion can be effectively achieved by applying lithium hexamethyldisilazide (LHMDS) in toluene. LHMDS is thought to promote intramolecular transamidation, which leads to ring-expanded 10- and 11-membered heterocyclic products in modest to good yields. The process significantly broadens the substrate scope amenable to the HIRE strategy.
The First Presentation of Localized Scleroderma at Birth: Scleroderma as a Differential Diagnosis of Congenital Skin Lesion
Authors: Memar Elmira Hajiesmaeil , Safavi Moeinadin , Moradinejad Mohammad-Hassan , Ziaee Vahid
Published: February 2022

Localized scleroderma is an uncommon autoimmune disease characterized by fibrosis of the skin and underlying tissue without involvement of blood vessels or internal organs. It usually affects children during later childhood, and early presentation of localized scleroderma during infancy is rare. In the current study, we report a child with localized scleroderma-related presentations occurring at birth. A 2-day-old male neonate presented with a firm, erythematous, and slightly pigmented plaque on his left thigh, leading to a change in the diameter of the affected foot and contracture of the left knee. At the age of 7 months, he was referred to our rheumatology clinic with normal growth and development. Laboratory studies, including urine and blood high-performance liquid chromatography assay, antinuclear antibodies, antitopoisomerase I, and rheumatic factor, were in the normal range. No signs of ocular involvement were noted during ophthalmological consultation. Skin biopsy showed mild acanthosis and collagen bundles, which replaced the fat around the sweat glands. A final diagnosis of localized scleroderma was made. Treatment was started with oral prednisolone, oral methotrexate (MTX), and colchicine. The skin lesion stopped progressing after 3 months of treatment. Steroid was then tapered over 6 months, while MTX and colchicine were continued for 2 years. Localized scleroderma during early infancy is a rare disease, but it should be considered as a differential in infants with erythematous and firm lesions on their body at birth because early treatment can prevent future complications.
Assessment of Health-Seeking Behavior among Undergraduate Students at a University
Authors: Aranha Priya Reshma , Lobo Melba Roshini , Patil Seema
Published: February 2022

Background Students studying at a university of health sciences may have different perceptions regarding illness and treatment. Moreover, as they have access to healthcare, it may influence their health-seeking behavior. It is important to identify the health-seeking behavior of the students and to guide them accordingly.

Methods The present study was designed to assess the health-seeking behavior of undergraduate students. It was a cross-sectional descriptive study. A total of 236 students pursuing undergraduate courses in medicine, dentistry, nursing, and physiotherapy participated in the study. Checklist and perception scales were used to collect data that were then analyzed using descriptive and inferential statistics.

Results Use of the Internet to get information about illness, treatment, and medications (60.3%; 139), self-investigations (50.6%; 122) as well as self-medication practices (54.4%; 130) was commonly seen in students. Among the self-medications, antibiotics (63.7%; 152), antipyretics (45.6%; 109), analgesics (43.9%; 104), and cough syrup (48.9%; 116) were common. Regarding perception on health-seeking behavior, the majority (49.3%; 118) opined neutral for the statement that self-diagnosis is not wrong, (49.4%; 120) reported that over-the-counter medications can be taken, (66.5%; 157) agreed that keeping healthy by eating healthy can keep you away from the hospital. The barriers for health-seeking behavior, stigma, fear of confidentiality issues, fear of unwanted intervention, and unaware where to seek help were more commonly reported for mental healthcare-seeking behavior (odds ratio [OR]: 29.33, 23.18, 34.16, and 11.96, respectively), whereas issues relating to high cost, the long waiting hour in healthcare facility, and fear of side effects were reported for physical healthcare-seeking (OR: 9.80, 7.15, and 18.66, respectively) behavior.

Conclusion Self-investigation, self-medications, and use of the Internet to seek healthcare information are evident among students of university. Students exhibited different health-seeking behavior for physical and mental illnesses. Barriers to health-seeking also differed. Institutions should use this information for the effective usage of healthcare services by students.
Cartilage Chips in Rhinoplasty
Authors: Apaydin Fazil , Fernández-Pellón Garcia Rodrigo Fortunato , Sahin Fetih Furkan , Rahavi-Ezabadi Sara
Published: February 2022

Objective This study reveals that the cartilage chips can be a good solution for camouflage and augmentation in rhinoplasty.

Methods In this study, 64 patients who had undergone rhinoplasty from 2014 to 2019 were retrospectively studied. The average age was 31. Forty-nine patients had primary and 15 revision rhinoplasties. Cartilage chips were cut into less than 0.5-mm thickness dimensions changing from 2 to 10 mm. They were used to fill deep radix, depressions at the key area, supratip area, around the grafts to prevent their visibility at the tip. In addition, they were used in the fascia for augmentation. The cartilage chips were sculpted from the septal cartilage in 47, rib in 16, and ear cartilage in one case.

Results They were applied on the radix in 25, middle vault in 37, supratip area in 32, and on the tip in 12 cases. In 30 cases, cartilage chips were mixed with cartilage dust for better fixation and camouflage. They were placed in the fascia in three cases for dorsal augmentation. Complications were seen in three cases in the form of irregularities.

Conclusion Cartilage chips are found to be a powerful solution in terms of camouflage and augmentation.
SARS-CoV-2 Rapid Antigen Detection in Respiratory and Nonrespiratory Specimens in COVID-19 Patients
Authors: Kiro Vandana Vijayeta , Singh Parul , Srivastav Sharad , Aggarwal Richa , Soni Kapil Dev , Singh Yudhyavir , Singh Abhishek , Trikha Anjan , Mathur Purva
Published: February 2022

Rapid antigen testing for coronavirus disease 2019 (COVID-19) available at present provides immediate results at low cost with less expertise and without any need of sophisticated infrastructure. Most of these test kits available are for nasopharyngeal samples. This is a novel study to detect the presence of COVID antigen in samples other than throat and oropharyngeal. Various samples received from patients admitted in the COVID-19 dedicated center were tested for the presence of antigen. Same procedure was followed as done for the nasopharyngeal sample. A total of 150 samples were tested, which included ascitic fluid, pleural fluid, drain fluid, bile, bronchoalveolar lavage, cerebrospinal fluid, endotracheal tube aspirate, sputum, tissue, and urine. Out of 150, 11 (7.33%) were positive and 138 (92.66%) were negative for the antigen test. The COVID-19 antigen test kit, though designed for nasopharyngeal samples, was able to detect the presence of antigen in other clinical samples.
Frequency and Antibiotic Susceptibility of Pathogens from Cases of Urinary Tract Infection: A Prospective Observational Study
Authors: Choudhary Gautam Ram , Jain Pritesh , Pandey Himanshu , Madduri Vijay Kumar Sarma , Singh Mahendra , Gupta Prateek , Goyal Suresh , Tak Vibhor , Nag Vijaya Lakshmi
Published: February 2022

Objectives Urinary tract infection (UTI) is one of the most common diagnoses in patients visiting urology clinics. Rampant use of empiric and inadequate doses of antibiotics leads to an increase in resistance and poses a huge financial burden. We evaluated UTI in relation to antibiotics used, frequency, susceptibility, and resistance pattern of different pathogens at a tertiary care center and made some important observations.

Methods Prospectively 729 patients diagnosed with UTI attending a urology outpatient department from July 2018 to January 2020 were managed accordingly. Antibiotics were started on the basis of urine culture and sensitivity (c/s) or empirically and changed according to subsequent urine c/s. Repeat urine c/s was performed after 5 to 7 days of starting therapy and 10 days after completion of therapy.

Results Out of 729 subjects, 417 (57.2%) were males and 312 (42.8%) were females. The most common symptom at diagnosis was dysuria 512 (70.2%), whereas 221 (30.3%) patients presented with fever. Escherichia coli was the most common organism isolated, 453 (62.1%). Among 729 patients, 239 took antibiotics without c/s report, whereas in 490 patients antibiotics were prescribed after the report. A total of 431 (59.1%) patients required one antibiotic session for clearance of pathogen, whereas 135 (18.5%) required two sessions, and three sessions were required in 66 (9%) cases. Among 239 patients whose culture came out to be positive, 145 (60.6%) were found to be resistant to the previously given antibiotic and the common pathogens isolated were E. coli (61 [42%]), Pseudomonas (28 [19.3%]), Enterococcus (22 [15.1%]), Klebsiella (14 [9.6%]), and others.

Conclusion Unchecked, rampant, and inadequate use of antibiotics leads to complicated UTI with the increasing share of Pseudomonas, Klebsiella, or other dangerous microbes, which are difficult to treat as well as pose threat in the future.
Bilateral Pulmonary Hydatid Cyst in a Young Child: A Rare Case Report from North India
Authors: Datta Priya , Sharma Bhawna , Peters Nitin James , Khurana Sumeeta , Sehgal Rakesh
Published: February 2022

Echinococcosis or hydatid disease is caused by the larval stage of the dog tapeworm, that is, Echinococcus granulosus, E. multilocularis, E. vogeli, or E. oligarthrus. Echinococcus granulosus causes cystic echinococcosis, which has a worldwide distribution. Liver is the most common site, affecting approximately two-third of the patients, whereas lung involvement is seen in approximately 25% of cases. This case is a very rare scenario of bilateral pulmonary hydatid cysts in a young child having exposure to a pet dog with negative hydatid serology and normal eosinophil count.
Matching disruptive innovation paths with entrepreneurial networks: a new perspective on startups’ growth with Chinese evidence
Authors: Yu Weizhen , Dai Shuanping , Liu Feng , Yang Yi
Published: February 2022

This study examines the impacts of entrepreneurial networks on startups’ performance with a sample of 618 startups in China’s Yangtze River Delta region, focusing on matching disruptive innovation paths with network types. The results indicate that entrepreneurial networks (both heterogeneous and homogeneous) are meaningful for startups’ growth performance. The study finds that startups exploring low-end disruption may benefit more from heterogeneous peers and avoid networking with an abundance of homogeneous peers. However, if exploring new markets, both types of networks could provide positive impacts. The asymmetric mediation effects of disruptive innovation paths highlight the core of leveraging entrepreneurial networks, whether homogeneous or heterogeneous, is to activate network resources with proper disruption paths.
Visibility of development stories in selected religious media discourse
Authors: Gessese Negesse , Gebru Amanuel , Nigatu Biset
Published: February 2022

This study explores patterns in the portrayal of development issues in the religious media from 1993 to 2021, in an attempt to illustrate the existence of hierarchical representations of development issues using sources, actors, and dominant frames. To this end, we use a quantitative method that considers the development content of two Ethiopian religious magazines: Hamer and Hintset. Our results reveal that across the selected years, the two magazines together presented 685 articles on development (359 the Hamer and 326 in Hintset). We employ data analysis using SPSS software, in which both descriptive and inferential statistical techniques were utilized for data presentation. We determine that political, economic, and natural resource development issues are the most scarcely covered issues as compared to social, moral, peace themes. Economic (chi-square = 5.122, p = 0.024, and p < 0.05), social development issues (chi-square = 6.207, p = 0.018, and p < 0.05) have a relationship with the year of publication in Hintset. Adherents, believers at the grassroots level, were the most frequent sources and story actors in the magazines. This shows participatory development communication was employed in the mediatization of development issues. The frame of development issues did not have a relationship with the year of publication. Finally, Hamer and Hintset included significant coverage of development issues, although development priorities are different. Hamer covered more social development issues whereas Hintset covered more moral development issues. In summary, our findings reveal that the religious media’s representation of development (685 articles, 38.8%) is at a high level in Ethiopia. We, therefore, suggest that local and global development agencies should work with faith-based media as development partners.
Modeling pandemic surges using an electric circuit analogue
Authors: Thompson Avery
Published: February 2022

The spread of COVID-19 has much in common with the behavior of an electric circuit, which can be used to predict pandemic trends.
Nonlinear complexification of periodic orbits in the generalized Landau scenario
Authors: Herrero R. , Farjas J. , Pi F. , Orriols G.
Published: February 2022

We have found a way for penetrating the space of the dynamical systems toward systems of arbitrary dimension exhibiting the nonlinear mixing of a large number of oscillation modes through which extraordinarily complex time evolutions may arise. The system design is based on assuring the occurrence of a number of Hopf bifurcations in a set of fixed points of a relatively generic system of ordinary differential equations, in which the main peculiarity is that the nonlinearities appear through functions of a linear combination of the system variables. The paper outlines the design procedure and presents a selection of numerical simulations with a variety of designed systems whose dynamical behaviors are really rich and full of unknown features. For concreteness, the presentation is focused on illustrating the oscillatory mixing effects on the periodic orbits, through which the harmonic oscillation born in a Hopf bifurcation becomes successively enriched with the intermittent incorporation of other oscillation modes of higher frequencies while the orbit remains periodic and without the necessity of bifurcating instabilities. Even in the absence of a proper mathematical theory covering the nonlinear mixing mechanisms, we find enough evidence to expect that the oscillatory scenario be truly scalable concerning the phase-space dimension, the multiplicity of involved fixed points, and the range of time scales so that extremely complex but ordered dynamical behaviors could be sustained through it.
Gain-switching of 1.55 µm InP-based Qdash lasers grown on Si
Authors: Lin Qi , Xue Ying , Luo Wei , Huang Jie , Lin Liying , Lau Kei May
Published: February 2022

Reliable lasers on Si with large bandwidth are desirable for high-performance data communication systems on Si-photonics platforms. Here, we report short optical pulses generated by gain-switched InP-based 1.55 µm quantum dash (Qdash) lasers directly grown on (001) Si. The laser performance and related physical parameters were investigated by carrying out a gain-switching test for lasers on both Si and native InP substrates. The shortest pulses obtained were 217 and 252 ps for the lasers on InP and Si, respectively. By varying the electrical bias and pulse duration systematically, the evolution of the generated optical pulse duration and peak power was studied. The impact of cavity size on the optical pulse was also examined. Parameters were extracted using established equations fitted with our measurement results to gain insight into the underlying physics and correlation with the observed behavior. The obtained results indicate that the pulse width is limited by the low differential gain and strong gain compression of the active material. Our results indicate that Qdash lasers on Si can demonstrate comparable performance to those on a native InP substrate and manifest its potential application in an Si-based photonics chip for optical on-chip communications.
Application of hyperbolic geometry of multiplex networks under layer link-based attacks
Authors: Moshiri Mahdi , Safaei Farshad
Published: February 2022

At present, network science can be considered one of the prosperous scientific fields. The multi-layered network approach is a recent development in this area and focuses on identifying the interactions of several interconnected networks. In this paper, we propose a new method for predicting redundant links for multiplex networks using the similarity criterion based on the hyperbolic distance of the node pairs. We retrieve lost links found on various attack strategies in multiplex networks by predicting redundant links in these networks using the proffered method. We applied the recommended algorithm to real-world multiplex networks, and the numerical simulations show its superiority over other advanced algorithms. During the studies and numerical simulations, the power of the hyperbolic geometry criterion over different standard and current methods based on link prediction used for network retrieval is evident, especially in the case of attacks based on the edge betweenness and random strategies illustrated in the results.
Quantitative evaluation of energy harvesting capabilities on flexoelectric and piezoelectric materials
Authors: Zhang Shuwen , Zhai Chongpu , Liu Kaiyuan , Song Siyang , Ji Hui , Shao Shubao , Xu Minglong
Published: February 2022

Piezoelectric and flexoelectric materials have attracted increasing attention for mechanical energy harvesting (EH) in various applications, owing to their simple configuration, easy accessibility, high compatibility, and electro-mechanical conversion efficiency. In order to quantitatively evaluate the EH capability of different types of piezoelectric and flexoelectric materials, a coefficient m is proposed in this work, defined as the ratio of the square of electro-mechanical coupling coefficients and dielectric constant. With this proposed coefficient, we elucidate the underlying mechanism for the reason that polymer, ceramics, and ceramic–polymeric composite materials demonstrate different levels of energy conversion capabilities in piezoelectric and flexoelectric EH processes. Additionally, this proposed coefficient was used to guide the selection of piezoelectric EH materials for the power supply of a load cell integrated in a petroleum pumping system under extreme environments.
Design and modeling of a piezo-driven three-dimensional bridge-type amplification mechanism with input/output guiding constraint
Authors: Zhou Kuiyong , Liu Pengbo , Lu Shuaishuai , Yan Peng
Published: February 2022

Owing to the limited stroke of piezo stacks, compliant amplification mechanisms are widely employed to magnify the displacement of piezoelectric actuators for emerging applications in precision engineering. In this study, a three-dimensional (3D) bridge-type amplification mechanism composed of two serially connected bridge-type amplifiers with a novel constraint form has been developed. The parallel guiding beams mounted at the input and output ends significantly increase the lateral stiffness and minimize parasitic displacements for higher accuracy. Furthermore, a new theoretical model is established to predict the magnification behavior of the 3D amplifier that takes into account the displacement loss caused by the coupling of the two bridge-type amplifiers. The accuracy of this model and the mechanical performance of the developed amplifier are verified by conducting finite element simulations and experimental studies on the manufactured prototypes.
Sparse identification of nonlinear dynamical systems via non-convex penalty least squares
Authors: Lu Yisha , Xu Wei , Jiao Yiyu , Yuan Minjuan
Published: February 2022

This paper proposes a non-convex penalty regression method to identify governing equations of nonlinear dynamical systems from noisy state measurements. The idea to connect the non-convex penalty function instead of the l1 - norm with least squares is due to the fact that the l1 - norm excessively penalizes large coefficients and may incur estimation bias. The purpose of this work is to improve the accuracy and robustness in regression tasks. A threshold non-convex penalty sparse least squares optimization algorithm is developed, wherein the threshold parameter is selected using the L-curve criterion. With two examples of nonlinear dynamical systems, we illustrate the accuracy and robustness of the non-convex penalty least squares on noisy state measurements, indicating the validity of our method in a wide range of potential applications.
Energy filtering and phonon scattering effects in Bi2Te3–PEDOT:PSS composite resulting in enhanced n-type thermoelectric performance
Authors: Kim Cham , Lopez David Humberto
Published: February 2022

We blend n-type Bi2Te3 with an inexpensive abundant conducting polymer, poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS), to gain a bulk-structured composite, in which energy filtering and phonon scattering effects should occur at the interface of two components. The composite records somewhat higher electrical resistivity than pristine Bi2Te3, because the interface possibly interrupts carrier transport. However, the composite completely compensates for the resistivity increment with a significant increase in the Seebeck coefficient, which is caused by energy filtering effects at the interface; thus, it exhibits the improved power factor. The composite also records a much lower thermal conductivity than the pristine Bi2Te3 because of phonon scattering effects at the interface. The composite induces significant decoupling of electrical and thermal properties, thus affording the remarkably enhanced figure of merits (ZTmax ∼ 1.19 at 132 °C, ZTave ∼ 1.14 at 50–150 °C), which are approximately double those of the pristine Bi2Te3. The ZT values are not only predominant among the performance of n-type binary Bi2Te3, but they are also as competent as the excellent performance of n-type ternary Bi2(Te,Se)3 previously reported.
Effect of disordered nanoporosity on electrical and thermal properties of layered Ca3Co4O9 films
Authors: Paul Biplab , Zhang Yun , Zhu Wenkai , Xin Binbin , Ramanath Ganpati , Borca-Tasciuc Theodorian , Eklund Per
Published: February 2022

Independently controlling electronic and thermal transport in solids is a challenge, because these properties are coupled. Here, we show that disordered nanoporosity in Ca3Co4O9 thin films can decrease the thermal conductivity without significantly hampering electronic transport. Scanning thermal microscopy was used to determine the out-of-plane thermal conductivity and estimate the in-plane values. Nanoporous Ca3Co4O9 films exhibit a thermal conductivity of 0.82 W m−1 K−1, which is nearly twofold lower than that obtained from nonporous Ca3Co4O9 films. Nanoporous Ca3Co4O9 exhibit a room-temperature electrical resistivity of 4 mΩ cm, which is comparable to polycrystalline Ca3Co4O9 and twice that reported for single-crystal Ca3Co4O9. Our results suggest that controlling nanoporosity and their degree of disorder can offer a means of decoupling electrical and thermal properties in materials.
A machine learning method for transition prediction in hypersonic flows over a cone with angles of attack
Authors: Meng Deying , Shi Mingtao , Shi Yipeng , Zhu Yiding
Published: February 2022

The prediction of the transition location (TL) in three-dimensional (3D) hypersonic boundary layers is of great importance in hypersonic engineering. In the present work, a method using machine learning techniques is presented for the prediction of TLs based on experiment data over a Mach 6.5 inclined cone. A mapping function is directly constructed between TLs and the circumferential angle θ by neural networks (NNs). The results show that the present NN predicts well for both interpolations of both the angle of attack (AOA) and unit Reynolds number Re0 and extrapolation of only Re0 whereas errors increase for the extrapolation of a higher AOA. This work sheds new light on the fast prediction of TLs in hypersonic complex 3D boundary layers.
Features of accelerator-based neutron source for boron neutron capture therapy calculated by particle and heavy ion transport code system (PHITS)
Authors: Matsuya Yusuke , Kusumoto Tamon , Yachi Yoshie , Hirata Yuho , Miwa Misako , Ishikawa Masayori , Date Hiroyuki , Iwamoto Yosuke , Matsuyama Shigeo , Fukunaga Hisanori
Published: February 2022

Accelerator-based neutron sources have been developed and installed in recent decades for boron neutron capture therapy (BNCT) in several clinical facilities. Lithium is one of the targets that can produce epithermal neutrons from the 7Li(p,n)7Be near-threshold reaction, and accelerator-based BNCT systems employing a Li target are promising for cancer treatment. The accurate evaluation of the characteristics of an accelerator-based neutron source is a key to estimating the therapeutic effects of the accelerator-based BNCT. Particle and Heavy Ion Transport code System (PHITS) is a general-purpose Monte Carlo code, which can simulate a variety of diverse particle types and nuclear reactions. The latest PHITS code enables simulating the generation of neutrons from the 7Li(p,n)7Be reactions by using the Japanese Evaluated Nuclear Data Library 4.0 high-energy file. Thus, the PHITS code can be adopted for dose estimation during treatment planning for the accelerator-based BNCT. In this study, we evaluated the neutron fluence using the PHITS code by comparing it to reference data. The subsequent neutron transport simulations were performed to evaluate the boron trifluoride detector responses and the recoiled proton fluence detected by a CR-39 plastic detector. These comparative studies confirmed that the PHITS code can accurately simulate neutrons generated from an accelerator using a Li target. The PHITS code has a significant potential for a detailed evaluation of neutron fields and for predicting the therapeutic effects of the accelerator-based BNCT.
Numerical simulations for incompressible turbulence cavitation flows with tangent of hyperbola interface capturing (THINC) scheme
Authors: Xiao Teng , Xie Bin , Deng Xi , Du Yanping
Published: February 2022

In this work, we developed high-fidelity numerical solvers for turbulent cavitation flows and presented numerical simulations of cavitation and supercavitation behind an axisymmetric projectile and a conical cavitator. The proposed numerical solver is based on the homogeneous equilibrium model where the mass transfer rate between vapor and liquid is dependent on a volume of fraction (VOF) function. As a result, the numerical results of cavitation turbulent flow are heavily affected by the accuracy of the VOF evolution prediction. Thus, the proposed solver employs the Tangent of Hyperbola for INterface Capture method with Quadratic surface representation and Gaussian Quadrature scheme to accurately resolve the interfacial structures of cavitation bubbles. To effectively model the turbulent effects, the solver utilizes two approaches, respectively, i.e., the Smagorinsky model of large eddy simulation and the shear stress transport model of the Reynolds-averaged Navier–Stokes equation. The homogeneous turbulence equation systems are then discretized by the linear second-order schemes in space and time. The phase transition including both evaporation and condensation is described by the finite-rate mass transfer models such as Schnerr–Sauer and Kunz models. Numerical simulations and comparison studies are performed with the proposed solvers. Compared with previous simulation works, the current simulation results of cavity shape patterns and related hydrodynamic characteristics are in better agreement with experimental data and analytical theories, as well as reference solutions. These results validate that the proposed solver can produce high-fidelity predictions for solving the flow structures of cavitation and reentrant jet in the turbulent cavitation simulations.
Circular turbulent wall jets in quiescent and coflowing surroundings
Authors: Kazemi Mohammad , Khorsandi Babak , Mydlarski Laurent
Published: February 2022

The dynamics and mixing of circular turbulent wall jets released into both a quiescent background and coflowing stream have been investigated experimentally. The statistics of the velocity field (measured by way of acoustic Doppler velocimetry) for the wall jets emitted into a quiescent background agree well with those of the other studies. The experiments involving coflowing wall jets were undertaken at three different jet-to-coflow velocity ratios. The coflowing wall jets were found to decay and spread at slower rates and have lower mean lateral velocities compared to wall jets in quiescent surroundings. Moreover, the decay and spreading rates of the coflowing wall jets increased with increasing jet-to-coflow velocity ratios. The wall jets issued into a coflow also developed more slowly and reached self-similarity at farther downstream distances relative to those emitted into a quiescent background. Given the decreased decay rate, spreading rate, and mean lateral velocities of wall jets in the presence of a coflow, it was inferred that the entrainment into, and mixing of, the wall jets was reduced, presumably due to the suppresion by the coflow of the vortical structures that characterize wall jets in quiescent backgrounds. Finally, the root-mean-square velocities of the wall jets increased when a coflow was present, and were found to be nearly self-similar in the range of measurements studied herein, in contrast with coflowing jets (that are not released in the vicinity of a wall).
K-selective percolation: A simple model leading to a rich repertoire of phase transitions
Authors: Kim Jung-Ho , Goh K.-I.
Published: February 2022

We propose a K-selective percolation process as a model for iterative removals of nodes with a specific intermediate degree in complex networks. In the model, a random node with degree K is deactivated one by one until no more nodes with degree K remain. The non-monotonic response of the giant component size on various synthetic and real-world networks implies a conclusion that a network can be more robust against such a selective attack by removing further edges. From a theoretical perspective, the K-selective percolation process exhibits a rich repertoire of phase transitions, including double transitions of hybrid and continuous, as well as reentrant transitions. Notably, we observe a tricritical-like point on Erdős–Rényi networks. We also examine a discontinuous transition with unusual order parameter fluctuation and distribution on simple cubic lattices, which does not appear in other percolation models with cascade processes. Finally, we perform finite-size scaling analysis to obtain critical exponents on various transition points, including those exotic ones.
Phase diagram of the NaCl–water system from computer simulations
Authors: Bianco V. , Conde M. M. , Lamas C. P. , Noya E. G. , Sanz E.
Published: February 2022

NaCl aqueous solutions are ubiquitous. They can crystallize into ice, NaCl, or NaCl · 2H2O depending on the temperature–concentration conditions. These crystallization transitions have important implications in geology, cryopreservation, or atmospheric science. Computer simulations can help understand the crystallization of these solids, which requires a detailed knowledge of the equilibrium phase diagram. We use molecular simulations in which we put at contact the solution with the solid of interest to determine points of the solid–solution coexistence lines. We follow two different approaches, one in which we narrow down the melting temperature for a given concentration and the other in which we equilibrate the concentration for a given temperature, obtaining consistent results. The phase diagram thus calculated for the selected model (TIP4P/2005 for water molecules and Joung–Cheatham for the ions) correctly predicts coexistence between the solution and ice. We were only able to determine NaCl · 2H2O–solution coexistence points at higher temperatures and concentrations than in the experiment, so we could not establish a direct comparison in this case. On the other hand, the model underestimates the concentration of the solution in equilibrium with the NaCl solid. Our results, alongside other literature evidence, seem to indicate that ion–ion interactions are too strong in the model. Our work is a good starting point for the improvement of the potential model and for the study of the nucleation kinetics of the solid phases involved in the phase diagram.
Compact RSFQ microwave pulse generator based on an integrated RF module for controlling superconducting qubits
Authors: He Yuxing , Shen Hongxiang , Michibayashi Shiori , Zou Xihua , Xie Xiaojun , Yan Lianshan , Pan Wei , Yoshikawa Nobuyuki
Published: February 2022

An on-chip superconducting microwave pulse generator (MPG), incorporating rapid single-flux-quantum (RSFQ) logic gates and passive radio frequency (RF) components, is an energy-efficient solution for controlling superconducting quantum bits (qubits). Traditional RSFQ MPG designs, however, suffer from a large footprint as multiple RF components (including impedance matching networks, filters, etc.) are separately implemented one after another. In this Letter, we propose a compact on-chip MPG by introducing an integrated RF module. Using a generalized filter synthesis technique, the integrated RF module combines the functionalities of impedance matching and bandpass filtering as a single inductor-capacitor (LC) lumped network. Plenty of circuit elements can, thus, be saved, and the resultant LC network is applicable to both real and complex terminal impedance cases. For validation, a superconducting MPG adopting a fourth-order, 5 GHz centered, 100 MHz bandwidth integrated RF module is designed and fabricated, whose correct operations are confirmed through both simulation and measurement. These results raise the availability of controlling large-scale quantum systems by low-power superconductor technology in the future.
Elastic stiffening induces one-dimensional phonons in thin Ta2Se3 nanowires
Authors: Pan Zhiliang , Lee Seng Huat , Wang Ke , Mao Zhiqiang , Li Deyu
Published: February 2022

Compared to extensive studies of thermal transport in two-dimensional materials, very limited attention has been paid to the corresponding phenomenon in quasi-one-dimensional van der Waals crystals. Here, we show that Ta2Se3 can be easily exfoliated into thin nanowires, indicating strong anisotropy in the bonding strength within the basal plane. Systematic thermal property measurements disclose signatures of one-dimensional phonons as the nanowire hydraulic diameter reduces below 19.2 nm with linearly escalating thermal conductivity as temperature increases and size dependence inconsistent with the classical size effect. We further show that these unusual transport properties are induced by elastic stiffening occurring for wires of <30 nm diameter.
Spectral triple with real structure on fuzzy sphere
Authors: Chakraborty Anwesha , Nandi Partha , Chakraborty Biswajit
Published: February 2022

In this paper, we have illustrated the construction of a real structure on a fuzzy sphere S*2 in its spin-1/2 representation. Considering the SU(2) covariant Dirac and chirality operator on S*2 given by U. C. Watamura and Watamura [Commun. Math. Phys. 183, 365–382 (1997) and Commun. Math. Phys. 212, 395–413 (2000)], we have shown that the real structure is consistent with other spectral data for KO dimension-4 fulfilling the zero order condition, where we find it necessary to enlarge the symmetry group from SO(3) to the full orthogonal group O(3). However, the first order condition is violated, thus paving the way to construct a toy model for an SU(2) gauge theory to capture some features of physics beyond the standard model following Chamseddine et al. (J. High Energy Phys. 2013, 132).
NaCl stress modifies the concentrations of endophytic fungal hyphal and peramine in
Authors: Chen Taixiang , Simpson Wayne R. , Nan Zhibiao , Li Chunjie
Published: February 2022

Context Infecting grasses with an Epichloë endophyte contribute significantly to host plant salt tolerance. The Epichloë endophyte alkaloid peramine is primarily responsible for feeding deterrence against some herbivorous insects. Infection by an Epichloë is required for peramine production in the host grass. Limited information is available regarding the effects of salinity stress on Epichloë endophyte colonisation and associated production of peramine metabolites. Aims and methods In this study, we determined the effects of NaCl stress on the concentration of endophytic hyphae and peramine in wild barley (Hordeum brevisubulatum (Trin.) Link) seedlings infected with Epichloë bromicola. Key results Seedings dry weight at 4 weeks declined from 7.05 to 4.27 g/plant over the range, 0–300 mM NaCl. The hyphal concentration, as well as the peramine concentration, increased in response to high NaCl concentrations, hyphae and peramine concentration at 4 weeks increased from 13.29 to 264.60 copies/ng gDNA and from 26.75 to 43.19 μg/g DW, respectively. Peramine concentration was positively correlated with the concentration of hyphae (R2 = 0.4012, P < 0.001). Conclusions and implications It seems that peramine concentration was mostly explained by the in-planta variation in endophyte hyphae concentration in wild barley infected with Epichloë species under highly saline conditions.
Simulation of maize and soybean yield using DSSAT under long-term conventional and no-till systems
Authors: Rai Teerath , Kumar Sandeep , Nleya Thandiwe , Sexton Peter , Hoogenboom Gerrit
Published: February 2022

Context No-tillage (NT) has been gaining popularity over the conventional tillage (CT) for agricultural sustainability. Field experiments conducted worldwide to compare crop production under NT vs CT systems are generally site specific and expensive to maintain over longer duration. To overcome this gap, process-based models have been used to simulate the potential impact and benefits of various management practices on crop yield and soil properties under different environmental conditions. Aims (1) We evaluated the Cropping System Model (CSM)-CERES-Maize and CSM-CROPGRO-Soybean model for NT and CT systems; and (2) compared the long-term impacts of NT and CT on crop yield and soil organic carbon (SOC). Methods Two crop models, available in the Decision Support System for Agrotechnology Transfer (DSSAT), were calibrated and evaluated using maize (Zea mays L.) and soybean (Glycine max L.) yield data from 2006 through 2011 under CT and NT treatments. Key results For crop yield, we showed that the coefficient of determination (R2) for the calibration and evaluation phases of CERES-Maize model were 0.94 and 0.94, respectively, while the index of agreement (d) for these phases were 0.93 and 0.86. Similarly, the R2 values for the calibration and evaluation phases of CROPGRO-Soybean model were 1.00 and 0.65, respectively, with d-values of 0.99 and 0.85. Conclusions The results from these long-term (30-year) simulations suggest that compared to CT, the NT system enhanced SOC over time and, hence, crop yield and biomass production. Implications Application of NT can be beneficial for enhancing the soils and crop production in the long-term as compared to the CT system.
Relationship between elemental content determined
Authors: Faria Alvaro José Gomes de , Silva Sérgio Henrique Godinho , Melo Leônidas Carrijo Azevedo , Botelho Lívia , Guilherme Luiz Roberto Guimarães , Curi Nilton
Published: February 2022

Context Studies comparing the elemental contents obtained via portable X-ray fluorescence (pXRF) spectrometry under different scanning conditions and traditional time-consuming concentrated acid-digestion-based methods are rare in tropical soils. Aims (1) To compare the contents of Al, Ca, Cu, Fe, K, Mn, Zn, Cr, Ni, Ti, V and Zr obtained by pXRF with the results of the USEPA 3051a method; and (2) to evaluate the impacts of different conditions on the pXRF results. Methods Soil samples were analysed with pXRF under five conditions: field (F), post-field (PF), air-dried fine earth (ADFE, <2 mm), macerated (M), and macerated and sieved (MS, <150 μm). Linear regressions were adjusted between the USEPA 3051a and pXRF results for the five conditions. Coefficient of determination (R2), root-mean-square error (RMSE), and residual prediction deviation (RPD) were used as validation parameters for the models. Key results The different scanning conditions provided contrasting results for the total elemental contents via pXRF. The validation generated good models, as indicated by the condition, R2, and RPD values, and the results were, respectively: Ca (M; 0.88; 3.00), Cu (F; 0.91; 3.29), Fe (ADFE; 0.94; 4.14), Mn (F; 0.85; 2.65), Cr (ADFE; 0.86; 2.77), and Ni (ADFE and M; 0.74 for both; 2.10 and 2.08). Conclusions PXRF can accurately determine the contents of Ca, Cu, Fe, Mn, Cr and Ni in tropical soils compared with the 3051a method. Implications Results of the USEPA 3051a method can be accurately predicted via pXRF and regression models, reducing time, cost and work required.
The dynamic trophic architecture of open-ocean protist communities revealed through machine-guided metatranscriptomics
Authors: Lambert Bennett S. , Groussman Ryan D. , Schatz Megan J. , Coesel Sacha N. , Durham Bryndan P. , Alverson Andrew J. , White Angelicque E. , Armbrust E. Virginia
Published: February 2022

Significance

Mixotrophy is a ubiquitous nutritional strategy in marine ecosystems. Although our understanding of the distribution and abundance of mixotrophic plankton has improved significantly, the functional roles of mixotrophs are difficult to pinpoint, as mixotroph nutritional strategies are flexible and form a continuum between heterotrophy and phototrophy. We developed a machine learning–based method to assess the nutritional strategies of in situ planktonic populations based on metatranscriptomic profiles. We demonstrate that mixotrophic populations play varying functional roles along physicochemical gradients in the North Pacific Ocean, revealing a degree of physiological plasticity unique to aquatic mixotrophs. Our results highlight mechanisms that may dictate the flow of biogeochemical elements and ecology of the North Pacific Ocean, one of Earth's largest biogeographical provinces.
Self-healing codes: How stable neural populations can track continually reconfiguring neural representations
Authors: Rule Michael E. , O’Leary Timothy
Published: February 2022

Significance

The brain is capable of adapting while maintaining stable long-term memories and learned skills. Recent experiments show that neural responses are highly plastic in some circuits, while other circuits maintain consistent responses over time, raising the question of how these circuits interact coherently. We show how simple, biologically motivated Hebbian and homeostatic mechanisms in single neurons can allow circuits with fixed responses to continuously track a plastic, changing representation without reference to an external learning signal.
Bacteroides thetaiotaomicron
uses a widespread extracellular DNase to promote bile-dependent biofilm formation
Authors: Béchon Nathalie , Mihajlovic Jovana , Lopes Anne-Aurélie , Vendrell-Fernández Sol , Deschamps Julien , Briandet Romain , Sismeiro Odile , Martin-Verstraete Isabelle , Dupuy Bruno , Ghigo Jean-Marc
Published: February 2022

Significance

Biofilms are communities of surface-attached bacteria exhibiting biofilm-specific properties. Although anaerobic biofilms impact health, industry, and environment, they are mostly studied in aerobic bacterial species. Here, we studied biofilm formation in
Bacteroides thetaiotaomicron
, an anaerobic gut symbiont degrading diet sugars and contributing to gut maturation. Although
B. thetaiotaomicron
adhesion contributes to intestinal colonization, little is known about the determinants of its biofilm capacities. We identified that bile is a physiologically relevant gut signal inducing biofilm formation in
B. thetaiotaomicron
and other gut Bacteroidales. Moreover, we showed that, in contrast to the known scaffolding role of extracellular DNA, bile-dependent biofilm requires a DNase degrading matrix DNA, thus revealing a previously unrecognized factor contributing to the adhesion capacity of major gut symbionts.
Fracture of model end-linked networks
Authors: Barney Christopher W. , Ye Ziyu , Sacligil Ipek , McLeod Kelly R. , Zhang Han , Tew Gregory N. , Riggleman Robert A. , Crosby Alfred J.
Published: February 2022

Significance

Fracture of polymer networks is molecular in nature as chains must rupture for a crack to propagate. Predicting macroscopically measured fracture properties from molecular parameters a priori has remained elusive, even for well-defined networks. This work shows that a newly developed theory, which accounts for network defects, quantitatively describes both experimental measurements and molecular dynamics (MD) simulation data for fracture of a polymer network with independently defined or measured parameters. This advance provides a missing link between chemistry and materials science and engineering for polymer networks.
Somatostatin-type and allatostatin-C–type neuropeptides are paralogous and have opposing myoregulatory roles in an echinoderm
Authors: Zhang Ya , Yañez-Guerra Luis Alfonso , Tinoco Ana B. , Escudero Castelán Nayeli , Egertová Michaela , Elphick Maurice R.
Published: February 2022

Significance

Somatostatin (SS) and allatostatin-C (ASTC) are related neuropeptide hormones that act as inhibitory regulators of physiological processes in chordates (e.g., humans) and protostome invertebrates (e.g., insects), respectively. We have discovered that echinoderms (e.g., starfish) uniquely have both SS-type and ASTC-type neuropeptides, which act as inhibitory and excitatory regulators of muscle activity, respectively. Our findings suggest that SS-type and ASTC-type neuropeptides evolved by duplication of a common ancestral encoding gene. Then, one of the neuropeptides was lost in protostomes and chordates, probably because of their functional redundancy as inhibitory regulators. Conversely, the unique retention of both neuropeptide types in echinoderms may be explained by evolution of an excitatory role for ASTC-type neuropeptides mediated by yet-to-be-determined signaling mechanisms.