bluuebunny/crossref_metadata_2025 huggingface dataset:
Epsilon-negative media from the viewpoint of materials science
Authors: Fan Guohua , Sun Kai , Hou Qing , Wang Zhongyang , Liu Yao , Fan Runhua
Published: April 2021

A comprehensive review of the fundamentals and applications of epsilon-negative materials is presented in this paper. Percolative composites, as well as homogeneous ceramics or polymers, have been investigated to obtain the tailorable epsilon-negative properties. It's confirmed the anomalous epsilon-negative property can be realized in conventional materials. Meanwhile, from the perspective of materials science, the relationship between the negative permittivity and the composition and microstructure of materials has been clarified. It's demonstrated that the epsilon-negative performance is attributed to the plasmonic response of delocalized electrons within the materials and can be modulated by it. Moreover, the potential applications of epsilon-negative materials in electromagnetic interference shielding, laminated composites for multilayered capacitance, coil-less electric inductors, and epsilon-near-zero metamaterials are reviewed. The development of epsilon-negative materials has enriched the connotation of metamaterials and advanced functional materials, and has accelerated the integration of metamaterials and natural materials.
Real contact ratio and tooth bending stress calculation for plastic/plastic and plastic/steel spur gears
Authors: Jabbour Toni , Asmar Ghazi , Abdulwahab Mohamad , Nasr Jose
Published: April 2021

This paper presents an iterative method for calculating the effective contact ratio and the bending tooth stress for a pair of plastic/plastic and plastic/steel spur gears with an involute profile. In this method, the pinion and the gear are modeled, at each moment of the mesh cycle, as equivalent springs in parallel undergoing the same displacement along the line of action. This leads to the calculation of the bending stress by taking into account the number of teeth initially in contact and those which enter in contact prematurely. We also investigate the influence of certain gear parameters, such as, the number of teeth, the pressure angle, and the module on the behavior of a pair of meshed gears. In addition, the variation of the bending stress at the tooth fillet is investigated for a pair of plastic/plastic and a pair of plastic/steel spur gears, in order to determine the critical configurations for which the bending stress is maximum. In general, the results obtained from the present method also show that the stress variation in plastic/plastic gears differs markedly from that in plastic/steel gears.
How does an industry control a decision support system for a long time?
Authors: Jani Mrudul Y. , Chaudhari Urmila , Sarkar Biswajit
Published: April 2021

The inventory system has been affected by many characteristics, among which deterioration of a food product is a critical issue. Chilled foods deteriorate during storage time, and their quality reduces over time. Indian Spiced Pulled Pork Sandwiches are very observable customer goods in India that are, in fact, unpreserved. If chilled foods’ original value reduces over time, consumers are not much likely to buy them. The retail price of chilled food maintained is strictly dependent on its quality. From the vendor’s approach, measuring quality and leftover value should be a severe commercial issue. The model aims to study deterioration together with the quality prediction of Indian Spiced Pulled Pork Sandwiches. This model measures food quality and leftover value. Deterioration rate is considered as a function of two-parameter Weibull distribution, suitable for bacterial inactivation, microbial growth, enzymes, nutrients, and pigments dreadful environments under a non-isothermal atmosphere. The dynamic structure of demand has its importance in business. The price-storage time of product-dependent demand rate is debated in this model as demand rarely remains constant. The objective is to maximize the vendor’s total profit concerning storage time and the product’s selling price. A numerical example supports the model. Sensitivity analysis is carried out to derive insights for decision-makers. The graphical result, in three dimensions, is exhibited with a supervisory decision.
On duality theory for multiobjective semi-infinite fractional optimization model using higher order convexity
Authors: Yadav Tamanna , Gupta S.K.
Published: April 2021

In the article, a semi-infinite fractional optimization model having multiple objectives is first formulated. Due to the presence of support functions in each numerator and denominator with constraints, the model so constructed is also non-smooth. Further, three different types of dual modelsvizMond-Weir, Wolfe and Schaible are presented and then usual duality results are proved using higher-order (K×Q) − (ℱ,α,ρ,d)-typeIconvexity assumptions. To show the existence of such generalized convex functions, a nontrivial example has also been exemplified. Moreover, numerical examples have been illustrated at suitable places to justify various results presented in the paper. The formulation and duality results discussed also generalize the well known results appeared in the literature.
Leptospirose-assoziiertes Kawasaki-Syndrom – Differenzialdiagnose oder Krankheitsassoziation?
Authors: Nashawi Mohammed , Reichert Friedrich , Blankenburg Friederike , Heinkele Anita , Stirnkorb Christian , Noll Felix , Timmermann Kirsten , Hospach Toni
Published: April 2021

Einleitung: Das Kawasaki-Syndrom (KS) ist eine systemische Vaskulitis, die mittelgroße Arterien betrifft. Obwohl Diagnose- und Klassifizierungskriterien existieren, kann die Abgrenzung von anderen Krankheiten schwierig sein.

Falldarstellung: Bei einer 3-jährigen Patientin wurden neben Fieber folgende Symptome und Befunde festgestellt: Konjunktivitis, zervikale Lymphadenopathie, Palmarschwellung, gerötete und rissige Lippen sowie ein makulöses Exanthem. Diese Befunde sind mit einem kompletten KS vereinbar. Die Urin-PCR auf Leptospiren war positiv. Nach 2 Wochen entwickelte sich eine periunguale Schuppung.

Diskussion: Dieser Fall zeigt, dass eine Leptospirose nicht nur ähnliche Symptome wie das KS aufweist, sondern auch mit dieser Erkrankung assoziiert sein kann. Dafür sprechen spezifische Befunde wie Schuppungen an Fingern, Zehen und Veränderungen der oropharyngealen Schleimhäute.
Therapie von Sprachentwicklungsstörungen: Eine Leitlinie ist längst überfällig
Authors: Kiese-Himmel Christiane
Published: April 2021

Für die Therapie von Sprachentwicklungsstörungen (SES) ist bislang weitgehend unklar, wie die Evidenz aus individueller therapeutischer Expertise in das klinisch-praktische Vorgehen integriert wird. Die Entwicklung einer Leitlinie zur Therapie von SES, insbesondere für Kindergarten- und Vorschulkinder, ist daher aus 2 Gründen längst überfällig und zugleich eine besondere Herausforderung: (1) SES, die nicht im Zusammenhang mit einer Komorbidität stehen, werden mit verschiedenen Termini belegt und (2) bilden alle SES eine Schnittstelle medizinischer, psychologischer, pädagogischer, linguistischer und sprachtherapeutischer Fachdisziplinen. Die Deutsche Gesellschaft für Phoniatrie und Pädaudiologie hat nun eine „Interdisziplinäre (S3-) Leitlinie zur Therapie von Sprachentwicklungsstörungen“ (Register-Nr. 049–015) bei der Arbeitsgemeinschaft Wissenschaftlicher Medizinischer Fachgesellschaften AWMF e. V. angemeldet. Damit soll die Lücke zwischen sprachtherapeutischer Praxis und Forschungsevidenz geschlossen werden, um für den individuellen Behandlungsfall eine möglichst optimale Therapieempfehlung bzw. Therapieentscheidung treffen zu können – basierend auf dem besten wissenschaftlich verfügbaren Fachwissen.
A Randomized Controlled Trial on the Effect of Standardized Video Education on Prenatal Genetic Testing Choices: Uptake of Genetic Testing
Authors: Stortz Sharon K. , Mulligan Sheila , Snipes Marie , Hippman Catriona , Shridhar Nirupama Nini , Stoll Katie , Lutgendorf Monica A.
Published: April 2021

Objective This study aimed to assess the use of a standardized prenatal genetic testing educational video and its effects on patient uptake of prenatal testing, patient knowledge, decisional conflict, and decisional regret.

Study Design This was an Institutional Review Board–approved randomized controlled trial. Patients were randomized to intervention (standardized video education) or control (no video education). The video education group viewed a 5-minute educational video on genetic testing options, and the control group did not review the video. Both groups answered validated questionnaires to assess maternal knowledge (Maternal Serum Screening Knowledge Questionnaire [MSSK]), conflict (Decisional Conflict Scale [DCS]), and regret (Decisional Regret Scale [DRS]). The primary outcome was genetic testing uptake; secondary outcomes were knowledge-based test score, and level of decisional conflict and regret.

Results We enrolled 210 patients between 2016 and 2020, with 208 patients randomized, 103 patients in the video education group and 105 patients in the control group. Four patients were excluded from the video education group for missing data. Video education was associated with a 39% lower chance of prenatal testing compared with patients who did not receive video education, (odds ratio 0.39, 95% confidence interval 0.16–0.92). Patients in the video education group had higher mean MSSKQ scores by 2.9 points (8.5 vs. 5.7, p < 0.001), lower Decisional Conflict Scores by 7.3 points (31.5 vs. 38.8, p < 0.001), lower Decisional Regret Scores by 5.4 points (23.8 vs. 29.2, p < 0.001).

Conclusion We found that video education on prenatal genetic testing improved patients' knowledge, decreased testing and decisional conflict and regret regarding testing. This may indicate improved understanding of testing options and more informed decisions that align with their personal values and beliefs. This standardized video can be easily implemented in clinical practice to increase patient understanding and support decisions that align with patient's values.

Key Points
Latency Period after Preterm Premature Rupture of Membranes: Singletons versus Twins
Authors: Madden Nigel , Andrikopoulou Maria , Overton Eve , Gyamfi-Bannerman Cynthia
Published: April 2021

Objective Several studies have evaluated the differences in duration of latency and clinical outcomes between singleton and twin pregnancies after preterm premature rupture of membranes (PPROM); however, these data are limited to single-institution analyses and based on small sample sizes. The aim of this study was to assess differences in latency and clinical outcomes in singletons versus twin gestations affected by PPROM in a large, diverse cohort of women.

Study Design This is a secondary analysis of a multicenter trial of magnesium for neuroprotection in women at high risk of preterm birth. Our study included women with PPROM ≥ 24 weeks with singleton and twin gestations. We compared singleton versus twin gestation and our primary outcome was duration of latency after PPROM. Secondary outcomes included selected perinatal and neonatal outcomes including long-term neurodevelopmental outcomes. We fit a linear regression model to assess independent risk factors for latency duration.

Results Our study included 1,753 women, 1,602 singleton gestations (91%) and 151 twin gestations (9%). The median latency period was significantly shorter in twins (4 [interquartile range, IQR: 1–10] vs. 7 [IQR: 3–16] days, p < 0.001) and gestational age at delivery was significantly earlier (29.3 vs. 30.1 weeks, p = 0.001). Twins were more likely to develop neonatal sepsis (20.1 vs. 13.4%, p = 0.004), but rates of chorioamnionitis and abruption did not differ. Twins were more likely to suffer from adverse short-term neonatal outcomes, had higher rates of neonatal demise (7.9 vs. 3.8%, p = 0.002), and had higher rates of cerebral palsy (7.3 vs. 3.7, p = 0.005). When adjusting for confounders, twin gestation remained an independent risk factor for shorter latency (p < 0.001).

Conclusion Twin gestations affected by PPROM had shorter latency, earlier delivery, and higher rates of short- and long-term morbidity. Despite having longer latency, singleton gestations did not have higher rates of complications associated with expectant management.

Key Points
Electronics meet biology to better measure cellular contraction
Authors: Patrick Chris
Published: April 2021

This perspective hopes to encourage involvement in the field of bioelectronics and its application to monitoring cellular contraction in real time and in vivo.
Dynamics of a fractional epidemiological model with disease infection in both the populations
Authors: Baishya Chandrali , Achar Sindhu J. , Veeresha P. , Prakasha D. G.
Published: April 2021

In order to depict a situation of possible spread of infection from prey to predator, a fractional-order model is developed and its dynamics is surveyed in terms of boundedness, uniqueness, and existence of the solutions. We introduce several threshold parameters to analyze various points of equilibrium of the projected model, and in terms of these threshold parameters, we have derived some conditions for the stability of these equilibrium points. Global stability of axial, predator-extinct, and disease-free equilibrium points are investigated. Novelty of this model is that fractional derivative is incorporated in a system where susceptible predators get the infection from preys while predating as well as from infected predators and both infected preys and predators do not reproduce. The occurrences of transcritical bifurcation for the proposed model are investigated. By finding the basic reproduction number, we have investigated whether the disease will become prevalent in the environment. We have shown that the predation of more number of diseased preys allows us to eliminate the disease from the environment, otherwise the disease would have remained endemic within the prey population. We notice that the fractional-order derivative has a balancing impact and it assists in administering the co-existence among susceptible prey, infected prey, susceptible predator, and infected predator populations. Numerical computations are conducted to strengthen the theoretical findings.
Tuning optical properties of self-assembled nanoparticle network with external optical excitation
Authors: Şenel Zeynep , İçöz Kutay , Erdem Talha
Published: April 2021

DNA-driven self-assembly enables precise positioning of the colloidal nanoparticles owing to specific Watson–Crick interactions. Another important feature of this self-assembly method is its reversibility by controlling the temperature of the medium. In this work, we study the potential of another mechanism to control the binding/unbinding process of DNA-functionalized gold nanoparticles. We employ laser radiation that can be absorbed by the gold nanoparticles to heat their network and disassociate it. Here, we show that we can actively control the optical properties of the nanoparticle network by external optical excitation. We find out that by irradiating the structure with a green hand-held laser, the total transmittance can increase by ∼30% compared to the transmittance of the sample not irradiated by the laser. Similarly, the optical microscopy images indicate the transformation of the nanoparticle network from opaque to transparent, while the nanoparticles formed a network again after the laser irradiation stopped. Our results prove that the optical excitation can be used to tailor the structure and thus the optical properties of the DNA-self-assembled nanoparticle networks.
Low temperature growth of stress-free single phase α-W films using HiPIMS with synchronized pulsed substrate bias
Authors: Shimizu Tetsuhide , Takahashi Kazuki , Boyd Robert , Viloan Rommel Paulo , Keraudy Julien , Lundin Daniel , Yang Ming , Helmersson Ulf
Published: April 2021

Efficient metal-ion-irradiation during film growth with the concurrent reduction of gas-ion-irradiation is realized for high power impulse magnetron sputtering by the use of a synchronized, but delayed, pulsed substrate bias. In this way, the growth of stress-free, single phase α-W thin films is demonstrated without additional substrate heating or post-annealing. By synchronizing the pulsed substrate bias to the metal-ion rich portion of the discharge, tungsten films with a ⟨110⟩ oriented crystal texture are obtained as compared to the ⟨111⟩ orientation obtained using a continuous substrate bias. At the same time, a reduction of Ar incorporation in the films are observed, resulting in the decrease of compressive film stress from σ = 1.80–1.43 GPa when switching from continuous to synchronized bias. This trend is further enhanced by the increase of the synchronized bias voltage, whereby a much lower compressive stress σ = 0.71 GPa is obtained at Us = 200 V. In addition, switching the inert gas from Ar to Kr has led to fully relaxed, low tensile stress (0.03 GPa) tungsten films with no measurable concentration of trapped gas atoms. Room-temperature electrical resistivity is correlated with the microstructural properties, showing lower resistivities for higher Us and having the lowest resistivity (14.2 μΩ cm) for the Kr sputtered tungsten films. These results illustrate the clear benefit of utilizing selective metal-ion-irradiation during film growth as an effective pathway to minimize the compressive stress induced by high-energetic gas ions/neutrals during low temperature growth of high melting temperature materials.
Flow destabilization and nonlinear solutions in low aspect ratio, corrugated duct flows
Authors: Pushenko V. , Gepner S. W.
Published: April 2021

Flows through narrow, rectangular ducts, with width to height aspect ratio below the established linear stability threshold of 3.2 and modified with grooves on top and bottom walls, are investigated. The primary objective of the current work lies in reintroduction of the linear destabilization mechanism, which is not present for the case of low aspect ratio rectangular ducts, via geometrical modifications of boundaries. The flow is assumed periodic in the streamwise- and bounded by sidewalls in the spanwise-direction. Applied geometrical modifications consist of two wavelengths of sinusoidal grooves running parallel to the flow direction. The current analysis starts with a brief characterization of flows through rectangular ducts and recalls some canonical results on hydrodynamic stability in such flows. In the second part, we illustrate that grooved geometries may lead to the onset of unstable modes in the form of waves traveling downstream, in the case of narrow ducts, already at relatively low values of the Reynolds number. The work is concluded with a concise characterization of flow states resulting from amplification of unstable modes into the nonlinear regime.
Spectroscopic properties of ErF3 doped tellurite–gallium oxyfluoride glass for ∼3 μm laser materials
Authors: Wan Rui , Wang Pengfei , Li Shengwu , Ma Yuan , Zhang Guangwei
Published: April 2021

ErF3-doped TeO2–Ga2O3–BaF2–AlF3–Y2O3 (TGBAY) glasses with high fluorescence efficiency and a high thermal damage threshold were developed for potential mid-infrared fiber laser applications. A model 2.7-μm fiber laser based on this material was analyzed using rate and propagation equations. Under 808 and 980 nm laser pumping, fluorescence emissions with central wavelength at 1.55 and 2.73 μm were detected. Based on the Judd–Ofelt (J–O) theory, the intensity parameters (Ωλ, λ = 2, 4, and 6) and radiative transition property were calculated and characterized through absorption and emission spectra. The results indicated that tellurite–gallium oxyfluoride glass had a high glass transition temperature (Tg, ∼391 °C), large emission cross sections at 1.55 μm (6.32 × 10−21 cm2) and 2.73 μm (9.68 × 10−21 cm2) as well as a longer fluorescence lifetime (6.84 ms at 1.55 μm and 262 μs at 2.73 μm) relative to the conventional Er3+-doped tellurite glass. The temperature dependence of the emission spectra indicated that TGBAY-2Er glass was more favorable to achieve infrared emission at low temperatures. Numerical simulation revealed the feasibility of achieving a ∼2.7 μm fiber laser operation based on the developed Er3+-doped tellurite–gallium oxyfluoride glass fiber.
Droplet collision and jet evolution hydrodynamics in wetting modulated valley configurations
Authors: Agrawal Shubham , Khurana Gargi , Dhar Purbarun
Published: April 2021

Droplet impact hydrodynamics on “V”-shaped valleys or grooves of variant wettability and geometric dimensions have been studied experimentally and probed theoretically. The groove geometry makes the hydrodynamics three-dimensional, as in addition to the droplet dynamics in the lateral direction, liquid jets are generated from the post-impact droplet along the axial direction of the groove. The effect of the impact Weber number (We) on the jet velocity, the non-dimensional spreading width (γ), and north-pole height (h*) has been studied. It has been observed that the inertial forces dominate over the surface forces for higher impact We and hence, the effect of wettability is not important. However, the wettability of the substrate has a significant role in lower impact We as recoiling of the droplet is observed for the impact on the superhydrophobic substrate in this case. It has been observed that the spreading width of the post-impact droplet decreases with the increase in groove steepness. The jetting hydrodynamics has been probed and instantaneously after the impact, the generated jets travel at high velocity, but quickly reduce to a steady value. Jet velocity is observed to increase with an increase in the hydrophobicity of the substrate as well as the impact We. A semi-analytical formalism has been proposed to predict the jet velocity evolution in terms of governing Weber (We) and capillary (Ca) numbers. The predictions from the proposed model are in good agreement with the experimental results.
Bistable nanomagnet as programmable phase inverter for spin waves
Authors: Baumgaertl Korbinian , Grundler Dirk
Published: April 2021

To realize spin wave logic gates, programmable phase inverters are essential. We image using phase-resolved Brillouin light scattering microscopy propagating spin waves in a one-dimensional magnonic crystal consisting of dipolarly coupled magnetic nanostripes. We demonstrate phase shifts upon a single nanostripe of opposed magnetization. Using micromagnetic simulations, we model our experimental finding in a wide parameter space of biasfields and wave vectors. We find that low-loss phase inversion is achieved, when the internal field of the oppositely magnetized nanostripe is tuned such that the latter supports a resonant standing spin wave mode with an odd quantization number at the given frequency. Our results are key for the realization of phase inverters with optimized signal transmission.
Global order parameters for particle distributions on the sphere
Authors: Božič A. , Franzini S. , Čopar S.
Published: April 2021

Topology and geometry of a sphere create constraints for particles that lie on its surface, which they otherwise do not experience in Euclidean space. Notably, the number of particles and the size of the system can be varied separately, requiring a careful treatment of systems with one or several characteristic length scales. All this can make it difficult to precisely determine whether a particular system is in a disordered, fluid-like, or crystal-like state. Here, we show how order transitions in systems of particles interacting on the surface of a sphere can be detected by changes in two hyperuniformity parameters, derived from a spherical structure factor and cap number variance. We demonstrate their use on two different systems—solutions of the thermal Thomson problem and particles interacting via an ultra-soft potential of the generalized exponential model of order 4—each with a distinct parameter regulating their degree of ordering. The hyperuniformity parameters are able to not only detect the order transitions in both systems but also point out the clear differences in the ordered distributions in each due to the nature of the interaction leading to them. Our study shows that hyperuniformity analysis of particle distributions on the sphere provides a powerful insight into fluid- and crystal-like orders on the sphere.
Functional supramolecular systems: design and applications
Authors: Antipin Igor S. , Alfimov Mikhail V. , Arslanov Vladimir V. , Burilov Vladimir A. , Vatsadze Sergey Z. , Voloshin Yan Z. , Volcho Konstantin P. , Gorbatchuk Valery V. , Gorbunova Yulia G. , Gromov Sergey P. , Dudkin Semyon V. , Zaitsev Sergei Yu. , Zakharova Lucia Ya. , Ziganshin Marat A. , Zolotukhina Anna V. , Kalinina Maria A. , Karakhanov Eduard A. , Kashapov Ruslan R. , Koifman Oskar I. , Konovalov Alexander I. , Korenev Vladimir S. , Maksimov Anton L. , Mamardashvili Nugzar Zh. , Mamardashvili Galina M. , Martynov Alexander G. , Mustafina Asiya R. , Nugmanov Ramil I. , Ovsyannikov Alexander S. , Padnya Pavel L. , Potapov Andrei S. , Selektor Sofiya L. , Sokolov Maxim N. , Solovieva Svetlana E. , Stoikov Ivan I. , Stuzhin Pavel A. , Suslov Evgenii V. , Ushakov Evgeny N. , Fedin Vladimir P. , Fedorenko Svetlana V. , Fedorova Olga A. , Fedorov Yury V. , Chvalun Sergei N. , Tsivadze Aslan Yu. , Shtykov Sergei N. , Shurpik Dmitriy N. , Shcherbina Maxim A. , Yakimova Luidmila S.
Published: April 2021

The interest in functional supramolecular systems for the design of innovative materials and technologies, able to fundamentally change the world, is growing at a high pace. The huge array of publications that appeared in recent years in the global literature calls for systematization of the structural trends inherent in the formation of these systems revealed at different molecular platforms and practically useful properties they exhibit. The attention is concentrated on the topics related to functional supramolecular systems that are actively explored in institutes and universities of Russia in the last 10–15 years, such as the chemistry of host–guest complexes, crystal engineering, self-assembly and self-organization in solutions and at interfaces, biomimetics and molecular machines and devices.

The bibliography includes 1714 references.
Potential expansion of Hass avocado cultivation under climate change scenarios threatens Mexican mountain ecosystems
Authors: Charre-Medellín Juan F. , Mas Jean-François , Chang-Martínez Laura A.
Published: April 2021

Analysis of potential areas for crop establishment is necessary for sustainable agricultural planning, conservation of natural ecosystems, and achievement of food security’s current global objective. This study aims to model the current potential distribution of the optimal areas for Hass avocado crop in Mexico, along with the likely impact of climate change on the crops and the surrounding mountain ecosystems in the state of Michoacán, the principal producer. The maximum entropy approach was used to model the current and future potential distribution of the avocado using points of presence of avocado cultivation in Mexico and climatic variables under 10 global climate models (GCMs) and three representative concentration pathways (RCPs) from the IPCC. We estimated a current potential area for the establishment of Hass avocado crops in Mexico of 54 597 km2, associated with the temperate forests of the Transversal Volcanic Belt and the Sierra Madre del Sur. The loss of area for the establishment of avocado crops in Mexico was 31.1% under the most optimistic scenario, RCP 2.6, whereas 43.0% would be lost under the most pessimistic scenario, RCP 8.5. Currently, the potential distribution for the establishment of Hass avocado crops in the state of Michoacán is 22 561 km2. Given optimistic scenarios RCP 2.6 and RCP 8.5 of climate change by 2050, temperate forests mountain would represent 59 and 72.3%, respectively, of the potential area for establishing avocado in the state. Commercial pressure and climate change can lead to forest mountain ecosystem deforestation to establish new avocado crops and exacerbate water resource scarcity problems, jeopardising the entire production system’s sustainability. Territorial planning should prioritise conservation policies to avoid land-use change and establish strategies to maintain avocado crop sustainability in the long-term under climate change scenarios.
The long-distance flight behavior of
Drosophila
supports an agent-based model for wind-assisted dispersal in insects
Authors: Leitch Katherine J. , Ponce Francesca V. , Dickson William B. , van Breugel Floris , Dickinson Michael H.
Published: April 2021

Significance

Flying insects play a vital role in terrestrial ecosystems, and their decline over the past few decades has been implicated in a collapse of many species that depend upon them for food. By dispersing over large distances, insects transport biomass from one region to another, and thus, their flight behavior influences ecology on a global scale. Our experiments provide key insight into the dispersal behavior of insects and suggest that these animals employ a single algorithm that is functionally robust in both still air and under windy conditions. Our results will make it easier to study the ecologically important phenomenon of long-distance dispersal in a genetic model organism, facilitating the identification of cellular and genetic mechanisms.
Distinct signaling by insulin and IGF-1 receptors and their extra- and intracellular domains
Authors: Nagao Hirofumi , Cai Weikang , Wewer Albrechtsen Nicolai J. , Steger Martin , Batista Thiago M. , Pan Hui , Dreyfuss Jonathan M. , Mann Matthias , Kahn C. Ronald
Published: April 2021

Significance

Insulin and IGF-1 receptors share many downstream signaling pathways but have unique biological effects. Here, using global phosphoproteomics, we demonstrate that there are important differences in phosphorylation-mediated signaling between IR and IGF1R in both the basal and ligand-stimulated states involving multiple pathways of cellular regulation. Thus, mTORC1 and PIP3/AKT signaling, which are important in metabolism, are preferentially regulated by IR, while Rho GTPases, mitosis, and cell cycle proteins, which are involved in control of cellular growth, are preferentially regulated by IGF1R. These differences can be mapped to effects of both the extracellular and intracellular domains of these receptors. Thus, despite their high homology, IR and IGF1R preferentially regulate distinct networks of phosphorylation, contributing to the unique effects of these hormones.
Antagonistic activities of cotranscriptional regulators within an early developmental window set
FLC
expression level
Authors: Schon Michael , Baxter Catherine , Xu Congyao , Enugutti Balaji , Nodine Michael D. , Dean Caroline
Published: April 2021

Quantitative variation in expression of the
Arabidopsis
floral repressor
FLC
influences whether plants overwinter before flowering, or have a rapid cycling habit enabling multiple generations a year. Genetic analysis has identified activators and repressors of
FLC
expression but how they interact to set expression level is poorly understood. Here, we show that antagonistic functions of the
FLC
activator FRIGIDA (FRI) and the repressor FCA, at a specific stage of embryo development, determine
FLC
expression and flowering. FRI antagonizes an FCA-induced proximal polyadenylation to increase
FLC
expression and delay flowering. Sector analysis shows that FRI activity during the early heart stage of embryo development maximally delays flowering. Opposing functions of cotranscriptional regulators during an early embryonic developmental window thus set
FLC
expression levels and determine flowering time.
Kindergartens in Northern Norway as semiotic landscapes
Authors: Pesch Anja Maria , Dardanou Maria , Sollid Hilde
Published: April 2021

Educational institutions have a responsibility to ensure that all children receive care and equal possibilities for development, independent of their linguistic and cultural background. However, there is little knowledge about how kindergartens ensure a welcoming and inspiring place for both transnational migrants, Indigenous children, and children from the majority population. Through a semiotic landscape analysis from two kindergartens in Northern Norway, this article contributes to this knowledge gap. Our starting point is that educational spaces are social, cultural, and political places. Applying a Bakhtinian perspective on semiotic landscapes as dialogues, the analysis focuses on two discourses. The first concerns diversity as an individual or shared value, and the second concerns balancing the ordinary and the exotic. We find that diversity related to transnational migration seems to be more integrated into the semiotic landscape, while the minoritised Indigenous Sámi people is stereotypically represented in kindergartens.
Waste to worth: fruit wastes and by-products as animal feed.
Authors: Manju Wadhwa Manju Wadhwa , Bakshi M. P. S. , Makkar H. P. S.
Published: April 2021

The increasing trend future consumption of animal products will give rise to a huge demand of animal feed. Meeting this demand will be a challenge, given the scarcity of natural resources such as land and water. Currently approximately 1.3 billion tonnes of food is lost and wasted annually, and fruit and vegetables (FV) form a substantial part of this loss. Use of FV loss and waste, as animal feed, can contribute to meeting the feed deficiency existing in most developing countries. Also their use as animal feed will bring them back into the human food chain. Simultaneously it will help mitigating environmental problems that arise due to decomposition of such wastes in the environment. This review, first in a series, discusses options and challenges in using fruit wastes and by-products as animal feed. The fruits discussed are amla, apple, apricot, banana, citrus and raspberry, among many others. The nutritional value, conservation methods, feeding management and guidance on the levels at which these unconventional feed resources can be used in the diets of farm animal species are presented. Some of the major constraints in the use of fruit wastes and by-products are the presence of pesticides, pesticide residues, mycotoxins, heavy metals, furans and dioxins. There is a need to regularly monitor such contaminants in these feed resources. Equally important is to conduct risk assessment given the presence of these contaminants in the animal diets. A concerted research and commercial efforts are needed to realize the full potential of such wastes and by-products for the animal agriculture.
SARS-CoV-2 spike therapeutic antibodies in the age of variants
Authors: Baum Alina , Kyratsous Christos A.
Published: April 2021

Christos Kyratsous, Vice President of Research, Infectious Diseases, and Viral Vector Technologies at Regeneron Pharmaceuticals, and Alina Baum, Associate Director, Infectious Diseases Associate at Regeneron Pharmaceuticals, discuss the development of antibody therapeutics targeting the spike protein of SARS-CoV-2.
SVM Approach for Forecasting International Tourism Arrival In East Java
Authors: Purnaningrum Evita , Athoillah Muhammad
Published: April 2021

The maneuver of international tourists visiting Indonesia, especially the East Java area, in positive correlation with time. In accordance with the government’s work program to increase GDP from the tourism sector. However, the condition necessary to be supported by the existence of feasibility and adequate tourism services. Facility improvements certainly require a projection of international tourist arrivals visiting East Java. SVM is a machine learning method that has shown excellent performance in predicting time series. In addition, analysis results have shown that SVM had able to predict foreign tourist visits with a high degree of accuracy. Therefore, this research can be used as a support for tourism facility procurement policies, especially in East Java.
Numerical study of disturbances generated by localized impulse action in a flat-plate boundary layer at Mach 2
Authors: Khaibullina S R , Yatskikh A A , Semenov A N , Kocharin V L
Published: April 2021

The work is devoted to the numerical simulation of the excitation and development of localized disturbances in the supersonic boundary layer of a plate with a sharp leading edge at a Mach number of 2 in a two-dimensional formulation. Artificial disturbances are generated with the help of localized in time and space by changing the boundary conditions to the velocity component normal to the surface. The studies for two intensities of the impulse action were carried out. It was found that with an increase in the intensity of the action on the boundary layer, the amplitude of the generated disturbances increases. The development of disturbances of various amplitudes is similar. The ratio of the level of total temperature pulsations to the level of mass flow pulsations was estimated for the investigated disturbances. It was found that at small distances from the source of disturbances, this ratio increases downstream, at the same time in the far field, it reaches a constant value.
The study of heat transfer during condensation on inclined pipes by gradient heatmetry
Authors: Mityakov V Yu , Sapozhnikov S Z , Zainullina E R , Babich A Yu
Published: April 2021

The paper presents results of studying of heat transfer during condensation on the outer surface of inclined pipe by using gradient heatmetry. The proposed approach made it possible to estimate distribution of local heat flux per unit area in several sections along the pipe’s length. Combination of gradient heatmetry and thermometry allows us to show dependence of heat transfer coefficient from the angle of pipe inclination. Under experimental conditions the maximal average heat transfer coefficient, α = 6.94 kW/(m2 • K), was observed when the pipe was tilted at the angle of ψ = 20° from vertical. The relative uncertainty of measured heat flux per unit area was of 7.5 %, and for heat transfer coefficient it does not exceed the level of 8.4%. The use of gradient heatmetry in this study provides us information about films thickness distribution over the pipe surface without optical visualization, which is especially important in experiments at industrial heat exchangers.
Experimental investigation of vortex core properties of a finite span wing and an isolated rotor model
Authors: Stepanov R P , Kusyumov A A , Pakhov V V , Mikhailov S A , Tarasov N N , Mirgazov R M
Published: April 2021

This work outlines results of an experimental investigation of vortex core properties of a finite span wing and a helicopter rotor model operating at hover mode. Experimental data was obtained using Stereo-PIV in T1-K wind tunnel at KNRTU-KAI named after A.N. Tupolev. An empirically derived formula is proposed, allowing to estimate the dependence of the vortex core size from the threshold Q-value. The wing tip vortices were measured for different angles of attack. The tip vortices from the rotor blades were measured at two collective pitch angles. The results indicate that the obtained empirical equation can be used to estimate the impact of the lowest threshold Q-value selection on the size of the vortex core, which facilitates a more objective approach compared to known methods, when used to eliminate non-essential vortical regions.
Effect of wood structure geometry during firebrand generation in laboratory scale and semi-field experiments
Authors: Kasymov D P , Agafontsev M V , Tarakanova V A , Loboda E L , Martynov P S , Orlov K E , Reyno V V
Published: April 2021

As the set of experiments result, statistically substantiated data were obtained on the laws of ignition of a model angular structure under conditions of a point source of heat exposure. The use of IR diagnostics made it possible to control the thermal picture in the experimental area, as well as to capture areas of the highest and lowest heating. In the Large Aerosol Chamber of IAO SB RAS, preliminary experiments were carried out on a “firebrand shower” model exposure, which is naturally occurring firebrands (flaming or glowing embers) with some types of construction materials (chipboards). The exposure of the samples to firebrands stream was provided using a firebrand generator of own original design. It was experimentally confirmed that particle size plays a significant role in the ignition of a building structure. If the characteristic particle size, which can be defined as the ratio of its volume to the surface area in contact with the wood, is less than a certain characteristic value, then the ignition mode with a sharp temperature maximum near the phase interface is not fulfilled. This can be explained by the prevailing heat removal into the external environment in comparison with the amount of heat coming from a heat gun and resulting from chemical reactions.
Dependence of the surfactant solutions surface tension on the concentration and on the temperature
Authors: Sibiryakov N
Published: April 2021

This paper presents the dependence of the surface tension on the surfactant concentration and on the temperature for anionic cetyltrimethylammonium bromide (CTAB) with a concentration of 1 mmol/L and two-ionic lauryl hydroxysultaine (LHS) with a concentration of 2.8 mmol/L. At a low concentration of the surfactant, the surface tension drops sharply at a certain temperature, and at a high concentration it changes slightly, much slower than surface tension of the pure water. Surface tension rapidly drops because micelles in the bulk become unstable and surfactant particles relocate to the interface.
Verification of the method for determining heat fluxes and heat loses in experiments with a shear-driving liquid film
Authors: Tkachenko E M , Belosludtsev V V
Published: April 2021

The cooling of microelectronic equipment is currently one of the most difficult problems of thermal physics. To achieve high heat fluxes and reduce the volume of liquid used, the technological solution looks especially promising, where heat is transferred from the fuel element to a thin, intensely evaporating film of liquid moving under the action of friction of a forced gas flow in a mini-or micro-channel. In recent works, the study of heat losses and determination of the true heat flux in experiments with an intensely evaporating liquid film moving under the action of a gas flow in a mini-channel was carried out. In this paper, the task is to verify the method for determining heat losses. Heat transfer in the convective flow regime is investigated. The experimental and calculated Nusselt numbers in convection experiments with complete channel flooding are in good agreement. In addition, the experimental and calculated Nusselt numbers for film flows are in good agreement. This indicates the correctness of the method for determining heat flux and heat losses in previous studies.
Optical properties of nanocolumnar silver films obtained by pulsed laser deposition
Authors: Starinskiy S V , Rodionov A A , Shukhov Yu G , Bulgakov A V
Published: April 2021

Nanostructured silver films are considered as an important material for biomedical applications due to their unique optical and antiviral/bactericidal properties. The character of silver films depends on morphology, structure and thicknesses, which are determined by the method and regime of synthesis. In present work we show that a relative thick silver film obtained by pulsed laser deposition has an interesting porous nanocolumnar morphology. Optical properties of the produced samples are investigated. An empirical dependence for determining the thickness of the silver coating from the optical transmission spectra is proposed.
Numerical simulation of crystallization on a stationary and rotating cooled disk
Authors: Kislitsyn S A , Berdnikov V S
Published: April 2021

The process of crystallization of silicon melt on a monotonically cooled disk located on the free surface of the melt is studied numerically. The influence of thermogravitational, thermal gravitational-capillary and mixed convection on the shape of the crystal-melt interface is investigated. In mixed convection modes, the speed of uniform rotation of the disk is set. The calculations were carried out in an axisymmetric formulation of problems by the finite element method using an adaptive triangular mesh and taking into account the latent heat.
The features of cavitation flow around a cylinder with a very low aspect ratio
Authors: Skripkn S G , Tsoy M A , Kravtsova A Y
Published: April 2021

The arising of the cavitation cavity behind the circular cylinder with aspect ratio 0.06 has been investigated using high-speed visualization. High-speed imaging at a sampling rate up to 200 kHz and even higher for the local areas allowed the spatial structure and dynamics of gas-vapor cavities thoroughly to be studied. The time dependence of the volume of the cavitation cavity on time was obtained for all investigated regimes. The vapor volume fraction, as expected, was found to increase with a decrease in cavitation number at higher flowrates. The feature of the separated cavitation cavity behind the cylinder is the complex structure consisting of the set of the flatted bubbles with a thin liquid interface between them. The collapse of the cavitation cavity proved to be always initiated only near one of the channel walls.
Void fraction of nitrogen-water flow in flat microchannels
Authors: Dementyev Yu A , Ronshin F V , Chinnov E A
Published: April 2021

In this study, we investigated a behavior of time-averaged void fraction in five flat microchannels with cross sectional area of 0.05x10, 0.09x10, 0.15x10, 0.05x20 and 0.15x20 mm2. The experiments have been conducted at fixed superficial velocity of liquid phase. The dependence between time-averaged void fraction and superficial gas velocity has been studied. It was shown, that this dependence may be approximate by power law with R2=0.968. The dependence between time-averaged void fraction and homogeneous void fraction has been investigated. It was shown that the height of channel has not been affected by void fraction behavior, however the width of channel has influence: with an increasing of the channel width the dependence line shifts towards lager homogeneous fractions. However to take into account the influence of the channel width on surface area occupied by gas and to generalize data further investigations are required.
Plasma-chemical synthesis of germanium nanotubes
Authors: Timerkaev B A , Kaleeva A A , Feltsinger V S , Zalialieva A A , Suleimanov R M , Ibragimov I S , Sorokina A R , Akhmetvaleeva A R
Published: April 2021

The paper describes the synthesis of germanium nanotubes in an argon microarc. The article presents the results of two experiments. The evaporation of germanium atoms was carried out from the surface of single-crystal germanium, which served as the anode of the microarc discharge. The synthesis of nanotubes was observed on the surface of a molybdenum cathode in the first experiment and on the surface of a graphite rod in the second experiment. The diameters of the obtained germanium nanotubes reach 800-900nm.
Simulation of electrical characteristics of positive glow discharge column in plane channel with longitudinal gas flow and additional gas injection through the side wall
Authors: Galeev I G , Asadullin T Y , Tsybikov R O
Published: April 2021

A model of positive glow discharge column in longitudinal flowing glow discharge with additional gas injection through the side wall is proposed. The main flow is pumped through the mesh electrodes located at the beginning and end of the plane discharge chamber. Analytical expressions are obtained for the distribution of the most important electrical characteristics in the discharge region: the electric field strength and the degree of gas ionization.
On the effect of large-scale perturbations of surface of a liquid electrolyte cathode on the properties of gas
Authors: Tazmeev A K , Tazmeeva R N , Tazmeev B K
Published: April 2021

A gas discharge between a liquid electrolyte cathode and a copper anode was experimentally investigated in the current range of 1-15 A in the presence of disturbances on electrolyte surface. Two options were considered. In the first variant, disturbances were created by supplying gas to the inside of surface layer of electrolyte. And in the second version, a two-level cathode zone was organised on the electrolyte surface.