bluuebunny/crossref_metadata_2025 huggingface dataset:
Heparin-binding VEGFR1 variants as long-acting VEGF inhibitors for treatment of intraocular neovascular disorders
Authors: Xin Hong , Biswas Nilima , Li Pin , Zhong Cuiling , Chan Tamara C. , Nudleman Eric , Ferrara Napoleone
Published: May 2021

Significance

Vascular endothelial growth factor (VEGF) inhibitors have transformed the treatment of intraocular vascular disorders. However, the burden of frequent intravitreal injections reduces patient compliance such that the impact in the “real world” is less than in clinical trials. Thus, there is a need to discover VEGF inhibitors than can be administered less frequently. We hypothesized that the ability to bind heparan-sulfate proteoglycans may be a strategy to promote intraocular retention and increase half-life. We designed a series of VEGF receptor 1 variants and identified some with strong heparin-binding characteristics that are more effective and durable in action in animal models of intraocular neovascularization than a standard of care like aflibercept. The work should fulfill an unmet medical need and advance therapy.
LXR directly regulates glycosphingolipid synthesis and affects human CD4+ T cell function
Authors: Waddington Kirsty E. , Robinson George A. , Rubio-Cuesta Beatriz , Chrifi-Alaoui Eden , Andreone Sara , Poon Kok-Siong , Ivanova Iveta , Martin-Gutierrez Lucia , Owen Dylan M. , Jury Elizabeth C. , Pineda-Torra Inés
Published: May 2021

Significance

This work shows that the liver X receptor (LXR) regulates glycosphingolipid biosynthesis expression in primary human T cells, thereby influencing T cell plasma membrane lipid composition, subsequent immune synapse formation, and T cell receptor-mediated signaling and function. Furthermore, we show LXR actions are differentially regulated in functional T cell subsets, supporting an important role for lipid metabolism in human T cell homeostasis. This new mode of action for LXR could be of therapeutic relevance to disorders characterized by defects in T cell signaling and metabolism, including autoimmune and neurodegenerative diseases, cardiovascular disease, and cancer.
Topological clustering of multilayer networks
Authors: Yuvaraj Monisha , Dey Asim K. , Lyubchich Vyacheslav , Gel Yulia R. , Poor H. Vincent
Published: May 2021

Significance

Multilayer network clustering is used in such diverse areas as optimal islanding of critical infrastructures, analysis of trade agreements, and monitoring ecological interaction patterns. We propose a perspective on multilayer network clustering based on the concept of shape. By invoking the machinery of topological data analysis, we first study a shape of each node neighborhood and then group nodes based on how similar shapes of their local neighborhoods are. The significance of this methodology can be viewed through an emerging problem of sustainability of house insurance to climate risks. The topological perspective opens possibilities for more systematic, robust, and mathematically rigorous integration of higher-order network properties and their interplay to the analysis of complex networks.
A biophysical limit for quorum sensing in biofilms
Authors: Narla Avaneesh V. , Borenstein David Bruce , Wingreen Ned S.
Published: May 2021

Significance

Biofilms are a ubiquitous form of bacterial community. Within biofilms, bacteria communicate via chemical signals in a process called quorum sensing (QS). However, if signal production is nutrient-limited, then the nutrient-deficient interior of a biofilm cannot contribute to QS, which limits the ability of bacteria to assess their own population and behave accordingly. Numerical simulations of competitions among biofilm bacteria led us to discover a biophysical limit on the efficacy of nutrient-limited QS. In view of this limit, we conclude that to be most effective QS signal production should be a prized function that is not metabolically slaved.
Cell lineage tracing links ERα loss in Erbb2-positive breast cancers to the arising of a highly aggressive breast cancer subtype
Authors: Ding Yunfeng , Liu Yonghong , Lee Dong-Kee , Tong Zhangwei , Yu Xiaobin , Li Yi , Xu Yong , Lanz Rainer B. , O’Malley Bert W. , Xu Jianming
Published: May 2021

Significance

HER2
+
breast cancers (BrCs) are heterogeneous, but they are treated as a single type. Using a mouse model with Erbb2 (the rodent homolog of HER2)-induced BrC and cell lineage-tracing capacity, we found that ERα
+
Erbb2
+
cancer cells proliferate slowly and are nonmetastatic but then progressively lose ERα expression to become fast proliferating and highly metastatic ERα
−
Erbb2
+
cancer cells. ERα
−
Erbb2
+
cancer cells with an ERα
−
origin proliferate fast, but they metastasize weakly. These findings suggest: 1) ERα expression should be preserved in ERα
+
HER2
+
BrCs to restrict growth and metastasis; 2) ERα
−
HER2
+
BrCs contain a highly metastatic subtype with an ERα
+
origin and a weakly metastatic subtype with an ERα
−
origin, indicating a future need to identify and differentially treat these two subtypes.
Galectin-1 fosters an immunosuppressive microenvironment in colorectal cancer by reprogramming CD8
+
regulatory T cells
Authors: Cagnoni Alejandro J. , Giribaldi María Laura , Blidner Ada G. , Cutine Anabela M. , Gatto Sabrina G. , Morales Rosa M. , Salatino Mariana , Abba Martín C. , Croci Diego O. , Mariño Karina V. , Rabinovich Gabriel A.
Published: May 2021

Significance

Although immune checkpoint blockade therapies have achieved long-term responses in several malignancies, in colorectal cancer (CRC) patients clinical benefit is observed only in heavily mutated tumors that are mismatch-repair–deficient or have high microsatellite instability. This limitation urges the identification of novel immune escape mechanisms and the design of additional immunotherapeutic modalities. We show that Galectin-1 (Gal-1) confers immune privilege to CRC by increasing the frequency of CD8
+
CD122
+
PD-1
+
regulatory T cells (Tregs) and accentuating their immunosuppressive activity in experimental models. Accordingly, analysis of CRC patient datasets revealed a “poor prognosis signature” characterized by high Gal-1 expression and elevated CD8
+
Treg score. Thus, targeting Gal-1/glycan interactions may represent a potential immunotherapeutic modality for treating CRC by recalibrating the CD8
+
Treg compartment.
Rhotics in Standard Scottish English
Authors: Meer Philipp , Fuchs Robert , Gerfer Anika , Gut Ulrike , Li Zeyu
Published: May 2021

The present study investigates rhotics in Standard Scottish English (SSE). Drawing on an auditory analysis of formal
speeches given in the Scottish parliament by 49 speakers (members of parliament and the general public), it examines whether an underlying
rhotic standard exists for SSE speakers from all over Scotland, whether and where rhotics are realized as trills/taps or approximants, and
what factors influence variation in the realization and distribution of rhotics. The results show that SSE is variably rhotic, with 54% of
all non-linking coda /r/ realized, and that trills/taps are more frequent in intervocalic (onset and linking coda) position. The findings
contradict the idea of SSE being generally rhotic but rather confirm previous reports of increasing occurrence of non-rhoticity, not just by
specific speaker groups, but also in a formal context. They further show that variation in rhotics in SSE foremost tends to be affected by
language-internal than language-external factors.
Reconsidering poetry’s difficulty and value in English as a second language and English as a foreign language
education
Authors: Boldireff Anastasia , Bober Chris
Published: May 2021

There is a longstanding stigma attached to the use of poetry in English Language Teaching (ELT). Poetry is
considered difficult and peripheral to ELT curricula and L2 teacher education. Until recently, there was little scholarly interest
in studying the effectiveness of poetry in second language teaching. This article aims to advance the research on the use of
poetry in ELT. Using a systematic literature review approach covering the years 2008–2020, the present study investigates whether
poetry remains underused and undervalued. It is structured around the questions: Is poetry a difficult subject to teach to ESL/EFL
learners and learn by L2 students? What value is there to teaching poetry in ELT? Of the 199 peer reviewed journal articles
retrieved, 43 met the inclusion criteria for this study and were examined in-depth. Two themes emerged from the analysis: the
perception of poetry and using poetry as a research tool in ELT. The majority of evidence was qualitative research, which included
19 case studies; whereas, the most used quantitative research designs were Random Control Trials. We attest to the need for more
rigorous scholarship on the part of researchers. Results show that poetry is a valuable tool for ESL/EFL students and teachers,
and not difficult for L2 learners. This study concludes with a call for including poetry in teaching practices.
Acute metformin administration increases mean power and the early Power phase during a Wingate test in healthy male subjects
Authors: Bastos‐Silva Victor José , Marinho Alisson Henrique , Bezerra da Silva José Bruno , de Barros Sousa Filipe Antônio , Learsi Sara , Balikian Pedro , Gomes de Araujo Gustavo
Published: May 2021

The present study tested the hypothesis that acute metformin would increase peak power measured during a Wingate test. Fourteen men (24 ± 6 years; 75.8 ± 10.2 kg; 177 ± 7 cm) participated in four test sessions, conducted in a crossover, counterbalanced, double‐blind model. The first and second sessions consisted of anthropometric measurements and one Wingate test per day to assess test‐retest reliability. In the last two sessions, the Wingate tests were performed on metformin (500 mg capsule, 1 hour before) or placebo (cellulose capsule, 1 hour before) condition. No differences were found between the placebo and metformin for peak power (1056.8 ± 215.8 W vs. 1095.2 ± 199.3 W, respectively; p = 0.24). Mean power (630.9 ± 87.8 W vs. 613.1 ± 94.8 W, respectively; p=0.01) and total work (18928 ± 2633 kJ vs. 18393 ± 2845 kJ, respectively; p = 0.01) in the metformin condition were higher than the placebo. The power were greater in metformin when compared to the placebo in moments 3 (p = 0.01), 4 (p = 0.01), 5 (p = 0.04), 6 (p = 0.04), 7 (p = 0.02), 8 (p = 0.03) and 9 (p = 0.01) seconds. There were no differences between conditions for the peak lactate (p = 0.08) and the rating of perceived exertion (p = 0.84). Acute metformin administration increased the early power phase and the mean power of a Wingate test.
When Is Scientific Dissent Epistemically Inappropriate?
Authors: Miller Boaz
Published: May 2021

Normatively inappropriate scientific dissent prevents warranted closure of scientific controversies and confuses the public about the state of policy-relevant science, such as anthropogenic climate change. Against recent criticism by de Melo-Martín and Intemann of the viability of any conception of normatively inappropriate dissent, I identify three conditions for normatively inappropriate dissent: its generation process is politically illegitimate, it imposes an unjust distribution of inductive risks, and it adopts evidential thresholds outside an accepted range. I supplement these conditions with an inference-to-the-best-explanation account of knowledge-based consensus and dissent to allow policy makers to reliably identify unreliable scientific dissent.
The Epistemic Value of the Living Fossils Concept
Authors: Watkins Aja
Published: May 2021

Living fossils, taxa with similar members now and in the deep past, have recently come under scrutiny. Those who think the concept should be retained have argued for its epistemic and normative utility. This article extends the epistemic utility of the living fossils concept to include ways in which a taxon’s living fossil status can serve as evidence for other claims about that taxon. I will use insights from developmental biology to refine these claims. Insofar as these considerations demonstrate the epistemic utility of the living fossils concept, they support retaining the concept and using it in biological research.
Final report, on-going key comparison BIPM.QM-K1, ozone at ambient level, comparison with METAS, July 2020
Authors: Viallon Joële , Idrees Faraz , Moussay Philippe , Wielgosz Robert , Nierderhauser Bernhard
Published: May 2021

Main text

As part of the ongoing key comparison BIPM.QM-K1, a comparison has been performed between the ozone standard of Switzerland maintained by the Swiss Federal Office of Metrology (METAS) and the common reference standard of the key comparison, maintained by the Bureau International des Poids et Mesures (BIPM). The instruments have been compared over a nominal ozone amount-of-substance fraction range from 0 nmol/mol to 500 nmol/mol.

To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/.

The final report has been peer-reviewed and approved for publication by the CCQM, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).
On the potential of hard ferrite ceramics for permanent magnet technology—a review on sintering strategies
Authors: Granados-Miralles Cecilia , Jenuš Petra
Published: May 2021

A plethora of modern technologies rely on permanent magnets for their operation, including many related to the transition towards a sustainable future, such as wind turbines or electric vehicles. Despite the overwhelming superiority of magnets based on rare-earth elements in terms of the magnetic performance, the harmful environmental impact of the mining of these raw materials, their uneven distribution on Earth and various political conflicts among countries leave no option but seeking for rare-earth-free alternatives. The family of the hexagonal ferrites or hexaferrites, and in particular the barium and strontium M-type ferrites (BaFe12O19 and SrFe12O19), are strong candidates for a partial rare-earth magnets substitution, and they are indeed successfully implemented in multiple applications. The manufacturing of hexaferrites into dense pieces (i.e. magnets) meeting the requirements of the specific application (e.g. magnetic and mechanical properties, shape) is not always straightforward, which has in many cases hampered the actual substitution at the industrial level. Here, past and on-going research on hexaferrites sintering is reviewed with a historical perspective, focusing on the challenges encountered and the solutions explored, and correlating the sintering approaches with the magnetic performance of the resulting ceramic magnet.
Cold plasma treatment of catalytic materials: a review
Authors: Di Lanbo , Zhang Jingsen , Zhang Xiuling , Wang Hongyang , Li Hong , Li Yanqin , Bu Decai
Published: May 2021

Catalytic materials play important roles in chemical, energy, and environmental fields. The exhaustion of fossil fuels and the resulting deteriorative environment have become worldwide problems to be solved urgently. Therefore, treatment of catalytic materials by a green process is required for a sustainable future, and the atom efficiency of the catalytic materials should be improved at the same time. Cold plasma is rich in high-energy electrons and active species, and the gas temperature can be close to room temperature. It has been proved to be a fast, facile, and environmentally friendly novel method for treating catalytic materials, and has aroused increasing research interests. First, plasma treatment can achieve the reduction, deposition, combination, and decomposition of active components during the preparation of catalytic materials. The fast, low-temperature plasma process with a strong electric field in it leads to different types of nucleation and crystal growth compared to conventional thermal methods. Correspondingly, the synthesized catalytic materials generally possess smaller particle sizes and controlled structure depending on the plasma processing parameters and the materials to be treated, which can enhance their activity and stability. Second, plasma treatment can achieve the modification, doping, etching, and exfoliation of the catalytic materials, which can tune the surface properties and electronic structures of the catalytic materials to expose more active sites. Third, plasma treatment can regenerate deactivated catalytic materials by removing the carbon deposits or other poisons, and reconstruction of the destroyed structure. This work reviews the current status of research on cold plasma treatment of catalytic materials. The focus is on physical and chemical processes during plasma processing, the processing mechanism of the catalytic materials, as well as the future challenges in this filed.
Design of a magnetically driven current cloak
Authors: García-Gordillo A S , Altshuler E
Published: May 2021

An inhomogeneity into a conductive matrix deforms the flow pattern of an applied electric current. A usual current cloak can be defined as a permanent modification of the matrix properties around the inhomogeneity guaranteeing that the current flow pattern is similar before and after passing by the modified zone, so it implies the ‘electrical invisibility’ of the inhomogeneous region. Here we introduce the concept of a current cloak that can be tuned by means on an external field. We demonstrate analytically and using finite elements simulations that a current cloak can be constructed and manipulated by an external magnetic field for a concrete system consisting in a magneto-resistive matrix with an inclusion of larger conductivity.
Programming Ozobots for teaching astronomy
Authors: Balaton Mariana , Cavadas Jorge , Simeão Carvalho Paulo , Lima J J G
Published: May 2021

Experimental teaching is essential for a good understanding of science, especially on Physics. Practical activities play an important role for engaging students with science, mainly when they interact directly with equipment, collect experimental data with computers and/or use interactive software for data analysis. In this work, we present the use of low-cost mini-robots as an ‘object-to-think-with’ for teaching and learning with technology. The activity concerns programming the robots to make them run in circular paths, record videos of their trajectories and analyse them with Tracker Software, to boost the study of Astronomy contents. This kind of practical activity develops multiple skills in students and is usually very well accepted because it involves robots, programming, manipulating technology and for raising topics that are difficult to understand in real-life observations, making them cognitively accessible to the vast majority of students. In this practical activity, students are asked to create the robot programming code and make a video recording (with a smartphone) of the robots’ trajectories, mediated by the teacher, who assists in the construction of the experimental activity and analysis of the data obtained. The results will allow students to understand Kepler’s laws of planetary motion and why some planets seem to have an apparent retrograde motion as seen from the Earth, a problem that arose in IV BC and was only officially solved by the Copernicus heliocentric model, published in 1543, the year of his death.
Impact of the I-value of diamond on the energy deposition in different beam qualities
Authors: Kaveckyte Vaiva , Carlsson Tedgren Åsa , Fernández-Varea José M
Published: May 2021

Diamond detectors are increasingly employed in dosimetry. Their response has been investigated by means of Monte Carlo (MC) methods, but there is no consensus on what mass densityρ, mean excitation energyIand number of conduction electrons per atomnceto use in the simulations. The ambiguity occurs due to its seeming similarity with graphite (both are carbon allotropes). Except for the difference inρbetween crystalline graphite (2.265 g cm−3) and diamond (3.515 g cm−3), their dielectric properties are assumed to be identical. This is incorrect, and the two materials should be distinguished: (ρ= 2.265 g cm−3,I= 81.0 eV,nce= 1) for graphite and (ρ= 3.515 g cm−3,I= 88.5 eV,nce= 0) for diamond. Simulations done with the MC codepenelopeshow that the energy imparted in diamond decreases by up to 1% with respect to ‘pseudo-diamond’ (ρ= 3.515 g cm−3,I= 81.0 eV,nce= 0) depending on the beam quality and cavity thickness. The energy imparted changed the most in cavities that are small compared with the range of electrons. The difference in the density-effect term relative to graphite was the smallest for diamond owing to an interplay effect thatρ,Iandncehave on this term, in contrast to pseudo-diamond media when eitherρorIalone were adjusted. The study also presents a parameterized density-effect correction function for diamond that may be used by MC codes like EGSnrc. Theestarprogram assumes thatnce= 2 for all carbon-based materials, hence it delivers an erroneous density-effect correction term for graphite and diamond. Despite the small changes of the energy imparted in diamond simulated with two differentIvalues and expected close-to-negligible deviation from the published small-field output correction data, it is important to pay attention to material properties and model the medium faithfully.
Development of a new piezoelectric galvanometer scanner: fabrication, operation, and measurements
Authors: Chiu Ya-Chu , Lin Chi-Ying , Yen Chien-Yu , Huang Yu-Hsi
Published: May 2021

Our objective in this study was to overcome the size and complexity of existing galvanometers by developing a direct-drive galvanometer based on the deformation of a double-layer ceramic piezoelectric disc with mirrored surface. The resulting device is extremely compact (0.41 mm), light weight, and highly responsive. The performance of the galvanometer was evaluated using an electronic speckle interferometer to characterize vibration mode characteristics. The voltage and input frequency can be adjusted to match the vibration amplitude and vibration mode required for practical galvanometer operations. Using a position sensitive detector, we recorded changes in the position of a light spot generated by a single-point laser by which to track changes in the optical path imposed by the galvanometer. Experiments using graphics drawn by an open-loop control system verified the performance of the device.
Prediction of crystal structures and motifs in the Fe–Mg–O system at Earth’s core pressures
Authors: Wang Renhai , Sun Yang , Wentzcovitch Renata M , Zheng Feng , Fang Yimei , Wu Shunqing , Lin Zijing , Wang Cai-Zhuang , Ho Kai-Ming
Published: May 2021

Fe, Mg, and O are among the most abundant elements in terrestrial planets. While the behavior of the Fe–O, Mg–O, and Fe–Mg binary systems under pressure have been investigated, there are still very few studies of the Fe–Mg–O ternary system at relevant Earth’s core and super-Earth’s mantle pressures. Here, we use the adaptive genetic algorithm (AGA) to study ternary Fe
x
Mg
y
O
z
phases in a wide range of stoichiometries at 200 GPa and 350 GPa. We discovered three dynamically stable phases with stoichiometries FeMg2O4, Fe2MgO4, and FeMg3O4 with lower enthalpy than any known combination of Fe–Mg–O high-pressure compounds at 350 GPa. With the discovery of these phases, we construct the Fe–Mg–O ternary convex hull. We further clarify the composition- and pressure-dependence of structural motifs with the analysis of the AGA-found stable and metastable structures. Analysis of binary and ternary stable phases suggest that O, Mg, or both could stabilize a BCC iron alloy at inner core pressures.
The smooth distributions of the surface states in a semi-bounded medium with an abruptly change in characteristics in dependence on the field amplitude
Authors: Savotchenko S E
Published: May 2021

The wave equation with the stepwise nonlinear coefficient on the semi-axis is considered. The boundary problems allowing to obtain the exact solutions of such nonlinear wave equation are proposed. Obtained solutions describe the features of the field localization near the surface covered with fully shielding film in the medium with an abruptly change in characteristics depending on the field. Five types of the surface states with the same structure but different amplitudes, phases, characteristic localization lengths and positions of the domain boundary are found. The features of the wave distributions and the influence of control parameters such as the threshold value of the switching field, surface amplitude and their derivatives on the wave characteristics are analyzed. The change in control parameters allows us to vary the position of the domain boundary.
Exact Anti-Self-Dual four-manifolds with a Killing symmetry by similarity transformations
Authors: Paliathanasis Andronikos
Published: May 2021

We study the group properties and the similarity solutions for the constraint conditions of anti-self-dual null Kähler four-dimensional manifolds with at least a Killing symmetry vector. Specifically we apply the theory of Lie symmetries to determine all the infinitesimal generators of the one-parameter point transformations which leave the system invariant. We use these transformations to define invariant similarity transformations which are used to simplify the differential equations and find the exact form of the spacetime. We show that the constraint equations admit an infinite number of symmetries which can be used to construct an infinite number of similarity transformations.
On the magnetized 3D flow of hybrid nanofluids utilizing nonlinear radiative heat transfer
Authors: Waqas Hassan , Farooq Umar , Alghamdi Metib , Muhammad Taseer , Alshomrani Ali Saleh
Published: May 2021

This article analyzes the heat transfer, non-linear thermal radiation, the Cattaneo-Christov heat flux model and velocity slip effects in hybrid nanofluid flow over a 3D moving sheet. The hybrid type nanoparticles like Ag-Cu and MoS2 and GO are suspended in working liquid. Hybrid nanoliquid is homogeneous-mixture with novel physical and chemical structures making it a promising option for improving thermal efficiency. Hybrid nanoliquids have high ability to absorb and preserve the hydrogen because of their very huge unique surface-area and distinctive and unusual nature of an each nanostructure. Nanostructure carbon atoms like graphite, graphene and few metals like molybdenum and magnesium have recently been found to store hydrogen due to their larger storage-capacity and the higher dehydrogenation and hydrogenation speeds. The system of the mathematical relation in PDEs form is converted to system of ODEs by employing suitable variables. The bvp4c tool available in computational software MATLAB is used for solving the dimensionless ordinary differential system. Furthermore, the flow expectations for each physical flow parameter like

0.1
≤
α
≤
1.2
,

0.4
≤
β
≤
1.2
,

2.0
≤
P
r
≤
5.0
,

0.1
≤
γ
≤
1.2
,

0.2
≤
R
e
≤
0.8
,

0.1
≤
M
≤
1.2
,

0.0
≤
R
d
≤
0.8
,

0.1
≤
E
c
≤
0.4
,

0.1
≤
N
r
≤
1.2
,

0.2
≤

ϕ

1

=

ϕ

2

≤
0.5.
,

0.1
≤
Ω
≤
0.6
,

1.5
≤

θ

w

≤
1.8
,

are discussed. The physical consequence of flow parameters against subjective flow fields are graphically highlighted with physical justifications. The vitality of prominent parameters against velocity field and temperature distribution is illustrated through graphs. The velocity field diminishes with a larger velocity slip parameter. The velocity field is enhanced by the higher estimations of the Grashof number. The consequence of temperature ratio parameter on thermal field is delineated. By enhancing the thermal relaxation parameter, the thermal field reduces.
Dynamic behaviors of a star-coupled underdamped system with multiplicative quadratic noise and periodic excitation
Authors: Li Pengfei , Tang Zeyu , Zhang Qian , Zhang Wei
Published: May 2021

The star-coupled linear underdamped system subject to multiplicative quadratic noise and periodic sinusoidal excitation are considered. The multiplicative noise is modeled as a quadratic polynomial function of symmetric trichotomous noise. Firstly, the stability conditions of the system and the stationary solution of the mean field are deduced by establishing the differential equations of the mean field. Then the synchronization conditions of the principal and general particles are obtained respectively. These conditions are beneficial for studying the collective behavior of the system and the motion characteristics of particles in different situations. Then the output signal-to-noise ratio of the coupled system is derived in detail for the first time. Moreover, the dynamic behaviors of the system are analyzed by analytical results and numerical simulations, including the collective behavior under different conditions, and the concrete influence of parameters on the output signal-to-noise ratio.
Parisi-Sourlas-like dimensional reduction of quantum gravity in the presence of observers
Authors: Podolskiy Dmitriy , Barvinsky Andrei O. , Lanza Robert
Published: May 2021

We show that in the presence of disorder induced by random networks of observers measuring
covariant quantities (such as scalar curvature) (3+1)-dimensional
quantum gravity exhibits an effective dimensional reduction at large spatio-temporal scales, which is
analogous to the Parisi-Sourlas phenomenon observed for quantum field theories
in random external fields. After averaging over disorder associated with observer networks, statistical properties of the latter determine both the value of gravitational constant and the effective cosmological constant in the model. Focusing on the dynamics of infrared degrees of freedom we find that
the upper critical dimension of the effective theory is lifted
from D
cr = 1+1 to D
cr = 3+1 dimensions.
Testing clockwork axion with gravitational waves
Authors: Chiang Cheng-Wei , Lu Bo-Qiang
Published: May 2021

We investigate the gravitational waves (GWs) produced from the Peccei-Quinn (PQ) phase transition associated with the clockwork axion. The PQ phase transition can be first-order when the dimension-6 operator is included into the scalar potential. The GWs from the PQ phase transition at scale in the range of 103-106 GeV are detectable for the BBO and ALIA interferometers. The LISA and Taiji interferometers can probe the GWs from the PQ scale f ≤ 104 GeV, while the GW signals from the scale f ≥ 105 GeV can be detected by the ground-based GW observatories ET and CE. We find that the parameter space κm
∼ 0.06-0.001, κl
∼ 0.04-0.001, and ε ∼ 0.1-0.01 at the scale f = 105 GeV and most of the parameter regions at the scale f = 106 GeV
have been excluded by the LIGO O2 run. The LIGO O3 and design phases can further probe the remaining parameter space.
We show that the GWs from the annihilation of domain walls with a PQ scale f ≃ 2 × 105 GeV can induce the
stochastic signals with the right amplitude for the NANOGrav 12.5-year observations, but having a steeper spectral slope than the observations.
The LIGO O3 run has the opportunity of detecting the GW signals from the first-order PQ phase transition around this scale.
Wavelike propagation of quorum activation through a spatially distributed bacterial population under natural regulation
Authors: Patel Keval , Rodriguez Coralis , Stabb Eric V , Hagen Stephen J
Published: May 2021

Many bacteria communicate using diffusible pheromone signals known as autoinducers. When the autoinducer concentration reaches a threshold, which requires a minimum population density or ‘quorum’, the bacteria activate specific gene regulatory pathways. Simple diffusion of autoinducer can activate quorum-dependent pathways in cells that are located at substantial distances from the secreting source. However, modeling has predicted that autoinducer diffusion, coupled with positive feedback regulation in autoinducer synthesis, could also allow a quorum-regulated behavior to spread more rapidly through a population by moving as a self-sustaining front at constant speed. Here we show that such propagation can occur in a population of bacteria whose quorum pathway operates under its own natural regulation. We find that in unstirred populations of Vibrio fischeri, introduction of autoinducer at one location triggers a wavelike traveling front of natural bioluminescence. The front moves with a well-defined speed ∼2.5 mm h−1, eventually outrunning the slower diffusional spreading of the initial stimulus. Consistent with predictions from modeling, the wave travels until late in growth, when population-wide activation occurs due to basal autoinducer production. Subsequent rounds of waves, including waves propagating in the reverse direction, can also be observed late in the growth of V. fischeri under natural regulation. Using an engineered, lac-dependent strain, we show that local stimuli other than autoinducers can also elicit a self-sustaining, propagating response. Our data show that the wavelike dynamics predicted by simple mathematical models of quorum signaling are readily detected in bacterial populations functioning under their own natural regulation, and that other, more complex traveling phenomena are also present. Because a traveling wave can substantially increase the efficiency of intercellular communication over macroscopic distances, our data indicate that very efficient modes of communication over distance are available to unmixed populations of V. fischeri and other microbes.
Enhancement for P300-speller classification using multi-window discriminative canonical pattern matching
Authors: Xiao Xiaolin , Xu Minpeng , Han Jin , Yin Erwei , Liu Shuang , Zhang Xin , Jung Tzyy-Ping , Ming Dong
Published: May 2021

Objective. P300s are one of the most studied event-related potentials (ERPs), which have been widely used for brain–computer interfaces (BCIs). Thus, fast and accurate recognition of P300s is an important issue for BCI study. Recently, there emerges a lot of novel classification algorithms for P300-speller. Among them, discriminative canonical pattern matching (DCPM) has been proven to work effectively, in which discriminative spatial pattern (DSP) filter can significantly enhance the spatial features of P300s. However, the pattern of ERPs in space varies with time, which was not taken into consideration in the traditional DCPM algorithm. Approach. In this study, we developed an advanced version of DCPM, i.e. multi-window DCPM, which contained a series of time-dependent DSP filters to fine-tune the extraction of spatial ERP features. To verify its effectiveness, 25 subjects were recruited and they were asked to conduct the typical P300-speller experiment. Main results. As a result, multi-window DCPM achieved the character recognition accuracy of 91.84% with only five training characters, which was significantly better than the traditional DCPM algorithm. Furthermore, it was also compared with eight other popular methods, including SWLDA, SKLDA, STDA, BLDA, xDAWN, HDCA, sHDCA and EEGNet. The results showed multi-window DCPM preformed the best, especially using a small calibration dataset. The proposed algorithm was applied to the BCI Controlled Robot Contest of P300 paradigm in 2019 World Robot Conference, and won the first place. Significance. These results demonstrate that multi-window DCPM is a promising method for improving the performance and enhancing the practicability of P300-speller.
Overview of the II International Conference on Metrological Support of Innovative Technologies – ICMSIT-II-2021
Authors: Antokhina Yu A , Ovodenko A A , Okrepilov V V , Kovalev I V , Voroshilova A A
Published: May 2021

The overview describes the main directions and results of the II International Conference “ICMSIT-II-2021” held in St. Petersburg in March 3-6, 2021. It gives the details about the participants and the proceedings. The anchor partner of Krasnoyarsk Science and Technology City Hall was St. Petersburg State University of Aerospace Instrumentation. A description of the main trends in modern innovative technologies, engineering and industrial physics as well as in the development of the third International Forum “Metrological Support of Innovative Technologies” by the St. Petersburg State University of Aerospace Instrumentation is given in the overview.
Building of a digital model of aluminum electrolysis modes
Authors: Vereschagina E A , Zolkin A L , Lavrov E A , Fakhertdinova D I , Dragulenko V V
Published: May 2021

The article discusses the issues of constructing a digital model of aluminum electrolysis modes. This model allows to achieve the specified criteria of the production process on the basis of scientific processing of historical data accumulated during the industrial production of aluminum at factories using a mathematical apparatus as well as to obtain recommendations on the values of control parameters. The study is aimed at achieving the business goals of the company’s management in particular on increasing of the profits by improving the quality and quantity of products with reduced production costs.
Competence-based approach in the training of physicists
Authors: Vasylyshyn Vitalii , Yekimov Sergey , Svitlana Nakhod , Yuliya Voytsekhovska , Otroshchenko Nataliia , Gavrilko Tetiana , Zheludenko Maryna , Mikheev Andriy , Tetiana Vynnyk
Published: May 2021

Competence is the ability of an individual to solve various practical tasks, a set of knowledge, skills and abilities required to perform a specific practical activity. The use of intersubject connections during the training of physicists, in our opinion, will make it possible to prepare specialists with a broad Outlook and good qualifications. The knowledge acquired in this way will allow future physicists to compete more successfully in the labor market. This may be important if, due to certain circumstances, it is not possible to work in a previously acquired specialty, this will allow you to choose a new profession in which you will be able to maximize the use of previously acquired competencies, as well as make the choice of a new profession more consciously.
Modeling the interaction of PbSe nanoparticles
Authors: Zakharov P V , Lutsenko I S , Markidonov A V , Cherednichenko A I
Published: May 2021

In this work, the interaction of two PbSe nanoparticles is studied by means of atomistic modeling within the framework of the molecular dynamics method. The considered model consisted of two nanoparticles, each of which contained 5398 atoms. The interaction between particles was described by means of the Leonardo-Jones pair potential supplemented by the Coulomb interaction. The paper considers the effect of temperature on the process of combining nanoparticles depending on the distance between them. Attention is paid to the deformation of PbSe particles. At the initial stage of model relaxation, diffusion processes occur along the surface of nanoparticles due to the presence of polarly charged (111) planes on the crystal surface. This process is accompanied by deformation of particles along the axis of mutual arrangement of PbSe. There is a tendency to an increase in deformation with increasing temperature. The tendency of increasing deformation with increasing distance between particles is characteristic. The presence of PbSe near the second particle leads to an increase in deformation with increasing temperature. The maximum deformation of the particles increased by 5%, compared to a single particle, where the deformation is due only to its own dipole moment.
Application of artificial intelligence and digital technologies in the organization of the educational process of specialists in the field of physics, engineering and metrology
Authors: Shamina S V , Munister V D , Zolkin A L , Verbitskiy R A , Dragulenko V V
Published: May 2021

The article deals with the problems and the importance of modern advanced learning. A model of teaching for students mastering programs of secondary and higher vocational education, based on the terminal-matrix approach, which includes the integration of several related disciplines, is proposed. The importance of artificial intelligence methods in engineering, physical, engineering education is substantiated by the example of checking of research results.
Modeling of rotational oscillations in a diesel locomotive wheel-motor block
Authors: Djanikulov Akhat T , Mamayev Sherali I , Kasimov Obidjon T
Published: May 2021

This article highlights the importance of the effective movement of the rolling stock and the coefficient of friction between the wheels and rails in their use. Factors affecting wheel friction with the rails were considered. During the study, the dependence of the coupling coefficient between the wheel and the rails on the speed of movement was considered. Accordingly, it was found that the coefficient of adhesion decreases with increasing speed.
One of the scenarios of transition to the turbulent mode of the flow of liquid crystals
Authors: Denisova O A
Published: May 2021

The article presents the results of an experimental study of the transition to a turbulent flow regime of thin layers of nematic liquid crystals (4-octyl-4’-cyanobiphenyl) with a thickness of 20-125 μm at temperature of 39° C. The cell we used was a “sandwich”, which was assembled from three translucent glass plates separated by narrow strips of gaskets. Shear effects on the cell were carried out by the pendulum method with a frequency of 190 Hz, the phoner method was used. The analysis of the amplitude dependence of the optical signal, its spectrum, as well as the amplitude dependence of the width of the spectrum showed that low-frequency modes appear in the fluctuation spectrum, which lead to the appearance of periodic convection in the nematic liquid crystal layer.
Developing a robot with computer vision for automating business processes of the industrial complex
Authors: Gavrilovskaya N V , Kuvaldin V P , Zlobina I S , Lomakin D E , Suchkova E E
Published: May 2021

Robotic Process Automation technology is one of the solutions implemented in mechanical engineering and industrial production. A business process is automated by observing how a person is doing a task in a graphical user interface. Then the cyberphysical device repeats the same task. A significant problem of the implementation of such automated systems is that if the work is to be carried out through the interface of a virtual desktop, then it is impossible to obtain data on the elements of the graphical interface without computer vision. The object of the research is the automation of business processes of the industrial complex using computer vision. The purpose of the study is to apply computer vision methods to automate business processes and develop an appropriate software robot. The paper analyzes computer vision methods for recognizing user interface elements and text within these elements. Moreover, the authors have developed and tested a cross-platform application that reproduces a business process using computer vision. The test results have shown that selected computer vision methods will help automate industrial production business processes on any platform with a virtual desktop interface.
Study of analytical solution of the thermal conductivity equation considering relaxation phenomena under the third class boundary conditions
Authors: Zhukov V V
Published: May 2021

Applying the variable separation method, an exact analytical solution is found for thermal conductivity equation, established based on the modified Fourier’s law with thermal flux relaxation and temperature gradient under Newton’s boundary conditions (BC). An alternative method is proposed for modeling the transient heat conduction in the plate washed at the boundaries by a liquid or gas, which differs from the traditional one in the absence of the need to determine the heat transfer coefficients from the criterial heat transfer equations, instead of which it is proposed to introduce summands into the classical heat conductivity equation. The summands should take into account the relaxation nature of solids, the features of heat transfer at the boundary, acceleration of heat flux and temperature gradient during the process.
Automatic adaptation of a Solar Plant Intelligent Control System
Authors: Engel E A , Engel N E
Published: May 2021

The article continues the authors’ scientific research in the field of solar plant intelligent control system. This paper presents a developed on-line and off-line automatic adaptation methods which allow solar plant intelligent control system to adapt to rapid dynamic of insolation in real time and to seasonal insolation fluctuations during night time. The experimental results show that the proposed solar plant intelligent self-adaptive control system produced robust and rapid maximum power point tracking, as compared to a classical solar plant MPPT system based on Perturb & Observe or particle swarm optimization under seasonal fluctuations or rapid dynamic of insolation.
Online training of students of applied physics in the field of circuitry
Authors: Luchaninov D , Bazhenov R , Sabirova V , Mamyrova M , Zholdosheva A
Published: May 2021

The aim of the study is to test the effectiveness of online teaching of students of applied physics (directions “Electric power and electrical engineering”, “Physics”) to the basics of circuitry and robotics. For the practical development of the principles of circuitry, the TinkerCAD Circuits modeling system is used, lectures and consulting events are implemented using Skype online communication and YouTube broadcasts. The training is based on the principles of gradual complication of tasks and training in invention. The study was conducted at Sholom-Aleichem Priamursky State University and Osh State University in the 2020-2021 academic year. Two groups were selected for the study, the control group (60 students) studied the basics of circuitry using the prepared tasks, the experimental group (72 students) used the TinkerCAD modeling system for training. The results of the study showed the effectiveness of the methodology used for the assimilation of knowledge and skills: an increase in the control group was 13 percent, while in the experimental group an increase of 42 percent was noted. During the research, an increase in the interest of students in the performance of work, attempts to self-improve working devices was noted. Further improvement of the methodology may be associated with the technical design of remote laboratories for circuitry and robotics.
Statistical series for the ordered array approximation of random variable
Authors: Polosin V G
Published: May 2021

Many papers contain the study of observation results by using statistical moments and signs of the shape of distributions of random variables. Most of the directions of the application of moments are based on the relationship of moments with the parameters of the shape and scale of distributions. Expansion of the boundaries for the distribution parameters area is possible by identifying new qualitative properties of these characteristics. For this reason, it is relevant to study the possibility of using the central moments of the n-th order when constructing a statistical series. The paper demonstrates the possibility of using distribution moments to construct a series of approximations of a sorted data sequence. In particular, a method is developed for the expansion of a monotone varying function in a power series, that it is based on obtaining the coefficients of the series by using the central moments of the n-th order which calculated from a random sample of data. There are also examples of sorted series approximation for typical known symmetric and asymmetric distributions. There are also examples of sorted series approximation for typical known symmetric and asymmetric distributions. The article illustrates the use of a statistical series for the study of arrays of random variables by the example of approximating a sorted sequence of one cycle of an electrocardiosignal.