Simultaneous Existence Research Articles

Isochronicity of bi-centers for symmetric quartic differential systems

<p style='text-indent:20px;'>In this paper we investigate the simultaneous existence of isochronous centers for a family of quartic polynomial differential systems under four different types of symmetry. Firstly, we find the normal forms for the system under each type of symmetry. Next, the conditions for the existence of isochronous bi-centers are presented. Finally, we study the global phase portraits of the systems possessing isochronous bi-centers. The study shows the existence of seven non topological equivalent global phase portraits, where three of them are exclusive for quartic systems under such conditions.</p>

Silicon cuboid nanoantenna with simultaneous large Purcell factor for electric dipole, magnetic dipole and electric quadrupole emission

The Purcell effect is commonly used to increase the spontaneous emission rate by modifying the local environment of a light emitter. Here, we propose a silicon dielectric cuboid nanoantenna for simultaneously enhancing electric dipole (ED), magnetic dipole (MD) and electric quadrupole (EQ) emission. We study the scattering cross section, polarization charge distribution, and electromagnetic field distribution for electromagnetic plane wave illuminating the silicon dielectric cuboid nanoantenna, from which we have identified simultaneous existence of ED, MD and EQ resonance modes in this nanoantenna. We have calculated the Purcell factor of ED, MD and EQ emitters with different moment orientations as a function of radiation wavelength by placing these point radiation source within the nanoantenna, respectively. We find that the resonances wavelengths of the Purcell factor spectrum are matching with the resonance modes in the nanoantenna. Moreover, the maximum Purcell factor of these ED, MD and EQ emitters is 18, 150 and 118 respectively, occurring at the resonance wavelength of 475, 750, and 562 nm, respectively, all within the visible range. The polarization charge distribution features allow us to clarify the excitation and radiation of these resonance modes as the physical origin of large Purcell factor simultaneously occurring in this silicon cuboid nanoantenna. Our theoretical results might help to deeply explore and design the dielectric nanoantenna as an ideal candidate to enhance ED, MD and EQ emission simultaneously with very small loss in the visible range, which is superior than the more popular scheme of plasmonic nanoantenna.

Supply/demand ratio for medical consultations, diagnostic tests and chronic kidney disease monitoring in the Brazilian National Health System: a descriptive study, state of São Paulo, Brazil, 2019.

To determine the supply/demand ratio for procedures related to diagnosis and treatment for chronic kidney disease in the Brazilian National Health System (SUS), in the state of São Paulo, Brazil, 2019. This was a descriptive study, using data from the SUS outpatient and hospital information systems. The numbers of medical consultations, diagnostic and chronic kidney disease monitoring tests, performed in the period, were compared with the demand estimation, obtained through ministerial guidelines. Exclusive SUS users were 28,791,244, and individuals with arterial hypertension and/or diabetes mellitus, 5,176,188. The number of procedures performed and the ratio between this number and the needs of the population were 389,414 consultations with nephrologists (85%); 11,540,371 serum creatinine tests (223%); 705,709 proteinuria tests (14%); 438,123 kidney ultrasounds (190%); and 1,045 kidney biopsies (36%). In the chronic kidney disease care in the SUS it could be seen simultaneous existence of lack of supply, waste and inadequate screening of important procedures.

Barriers to a sustainability transformation of meat production practices - An industry actor perspective

The negative impacts caused by current industrial meat production challenge industry actors to transform meat production towards more sustainable practices. However, despite the necessity for change and the availability of various sustainability solutions, transformational shifts have failed to materialize, so far. This study applies and extends the Kollmuss-Agyeman model of pro-environmental behavior to the context of producers and analyzes their perceived barriers to the transformation of meat production practices. The qualitative empirical study is based on 23 interviews with actors along the meat production chain. The analysis reveals that industry actors’ perceived barriers are highly complex. This complexity results from (1) multiple interactions among and between internal and external influencing factors and (2) the simultaneous existence of barriers that reinforce the status quo on the one hand and restrain the pursuit of sustainable production practices on the other hand. Based on these findings, opportunities for overcoming barriers are discussed in today's context. This study's contributions are twofold: First, the analysis complements previous research on barriers to sustainable meat production practices by detailing barriers and their interactions for actors along the entire meat production chain. Second, this investigation extends the Kollmuss-Agyeman model by specifying interactions of external influencing factors and by differentiating reinforcement and restraint barriers relevant for producers.

(2021) Volume 2, Issue 4 Cultural Implications of China Pakistan Economic Corridor (CPEC Authors: Dr. Unsa Jamshed Amar Jahangir Anbrin Khawaja Abstract: This study is an attempt to highlight the cultural implication of CPEC on Pak-China relations, how it will align two nations culturally, and what steps were taken by the governments of two states to bring the people closer.

(2021) Volume 2, Issue 4 Cultural Implications of China Pakistan Economic Corridor (CPEC Authors: Dr. Unsa Jamshed Amar Jahangir Anbrin Khawaja Abstract: This study is an attempt to highlight the cultural implication of CPEC on Pak-China relations, how it will align two nations culturally, and what steps were taken by the governments of two states to bring the people closer.

When multiple logics initiate a butterfly effect: the case of locum tenens physicians in Germany

AbstractModern work structures and organizations are often characterized by the simultaneous existence of multiple logics. Research has made profound efforts in describing a wide range of possible responses to different constellations of multiple logics in recent decades. But less is known about the subsequent effects of those responses. Since responses to multiple logics aim to change the initial constellation, they are likely to provoke counter-responses that alter the new constellation. Thus, as butterfly effect, certain strategies in dealing with multiple logics can initiate a series of responses that can lead to a fundamental change in the constellations of logics. The rise and fall of locum tenens physicians in Germany illustrate how series of responses can evolve, increase, and fundamentally alter the given constellation of logics. Thereby, our multi-method study also sheds light on the role of omnipresent actors and raises the question of how the actors can be theorized in a setting of multiple logics.

Evolutionary adaptation of DHFR via expression of enzyme isoforms with various binding properties and dynamics behavior: a bioinformatics and computational study.

We compared the binding properties and dynamics of three experimentally reviewed isoforms of human dihydrofolate reductase (DHFR). The cytoplasmic variants including isoforms1 and 2 (iso1 and iso2) are produced by alternative splicing; while the mitochondrial form is located in the mitochondria. The iso1 as the canonical sequence contains 187 residues, and iso2 differs from the iso1, where it has 1-52 residues missing at the N-terminus of canonical sequence. Here, the structural models of the iso2 and mitochondrial forms were constructed by the MODELLER program using the crystal structure of the iso1 as the template. Bioinformatics analysis on ligand-bearing structures demonstrates that mitochondrial variant forms more stable complex with ligands compared with iso1 and 2, indicating their different binding properties. The root mean square fluctuation (RMSF) data suggest that C-terminus of iso1 contains two representative highly flexible fragments, while iso2 contains a highly flexible fragment at N-terminus end. Interestingly, both ends of mitochondrial variant have a degree of rigidity. Finally, the observation of differences in structural dynamics and binding properties predicts that the simultaneous existence of enzyme isoforms is a way to increase the speed of the enzyme maneuver in response to various environmental conditions. This prediction needs to be tested experimentally.

Hamiltonian energy computation and complex behavior of a small heterogeneous network of three neurons: circuit implementation

Brain functions are sometimes emulated using some analog integrated circuits based on the organizational principle of natural neural networks. Neuromorphic engineering is the research branch devoted to the study and realization of such circuits with striking features. In this contribution, a novel small network of three neurons is introduced and investigated. The model is built from the coupling between two 2D Hindmarsh–Rose neurons through a 2D FitzHugh–Nagumo neuron. Thus, a heterogeneous coupled network is obtained. The biophysical energy released by the network during each electrical activity is evaluated. In addition, nonlinear analysis tools such as two-parameter Lyapunov exponent, bifurcation diagrams, the graph of the largest Lyapunov exponent, phase portraits, time series, as well as the basin of attractions are used to numerically investigate the network. It is found that the model can experience hysteresis justified by the simultaneous existence of three distinct electrical activities using the same set of parameters. Finally, the circuit implementation of the network is addressed in PSPICE to further support the obtained results.

The State, Crisis, and Working-Class Strategy in Antonio Gramsci’s Prison Notebooks

Abstract This article conducts a philological and diachronic reconstruction of the emergence and progressive formation of Gramsci’s theory of the state in the Prison Notebooks, in the process demonstrating its organic nexus with a specific conception of the nature and dynamics of crises, and its implications for working-class strategy in the struggle to construct a hegemonic alternative to the capitalist state. On the basis of this analysis, it seeks to extract the contemporary relevance of Gramsci’s theory of the integral state, political crises and his strategic proposal of the war of position for our contemporary global conjuncture, defined by the simultaneous existence of multiple interlocking crises – economic, public health, ecological and social.

The simultaneous existence of modernist and neo-avant-garde tendencies in nonconformist art of Ukraine in the 1980s

In the early 1980s, the nonconformist art movement in Odesa, which had been developing since the mid-1950s, was widened by a new generation of artists. Their art searches differed significantly from their senior colleagues, which led to the formation of a separate movement within nonconformism, which later became known as APTART. The differences were mainly in the worldview of artists, aesthetics, themes, artistic techniques. The art of the new generation was closer to the Western neo-avant-garde, while their older colleagues tended toward modernism. The presence of two different well-defined movements within the nonconformism, a phenomenon in itself countercultural to official culture, distinguished the artistic process in Odesa in the 1980s from other cities in Ukraine. It is these features of the artistic life of that time, still insufficiently covered and analysed. The text considers the part of the work of the Odesa APTART artists, which the most clearly displays the elements of neo-avant-garde aesthetics, that, accordingly, affected the artistic means: acts, performances happenings; the differences between the two groups of artists belonging to the nonconformist subculture were analysed. Specific acts, works of the APTART artists opposed to the background of creative activity of their colleagues are considered. The stages of the APTART artists’ creativity development are traced. Within the disclosure of the research theme, the text highlights the processes of nonconformist artistic life in the main cities of Ukraine, traces parallels to similar phenomena in world art. Due to the experience of recent researches, the terms that directly affect the subject of the paper are specified: nonconformism, informal art, avant-garde, modernism, neo-avant-garde.

Photon energy and photon behavior discussions

Photons (Solar) are the main source of energy available on Earth and provide hope of clean energy in the future, photon energy has particle characteristics, and there is an inevitable connection between the wave behavior and the particle behavior of light, in-depth understanding and exploration are required. Based on the hypothesis of the strong interaction between electrons and protons to generate photons, the energy and behaviors of photons are discussed herein. By analyzing and calculating the photon speed, the negative photon speed was found to be in excellent agreement with the existing light speed constant. The Compton effect wavelength shift was analyzed and deduced considering the interaction of positive photons and atoms, and new conclusions are drawn, proposing the reason why X-rays are positive photons. Based on existing data, the observed estimation value of the negative photon velocity shift is 0.0295 ppm. From the interaction of the spin-charged particles, the relationship between the photon wavelength and its magnetic moment was calculated. In addition, we analyzed and calculated the characteristics of photon orbits, inferred the mechanism of atomic luminescence, and qualitatively explained the phenomenon of blackbody radiation. Based on the effect of charged spin photons and the electromagnetic potential field, we explain the reason for the simultaneous existence of reflection and refraction. The relationship between the incident angle and the reflectivity was analyzed, and refractive index formulas were derived to reasonably explain the characteristics of the X-ray refractive index. As a result, edge diffraction is considered a special case of refraction. By analyzing the fluctuation of the potential field inside the atom, the diffraction phenomenon of charged particles is described, and a particle explanation of the phenomenon of light waves and beat frequencies interference is provided. It is believed that the physical model of photon charging conforms to the existing physical laws. Photon energy is kinetic energy and is derived from the potential energy of electrons or protons.

Line Scan Spatial Speckle Contrast Imaging and Its Application in Blood Flow Imaging

Laser speckle imaging has been an indispensable tool for visualizing blood flow in biomedical applications. We proposed a novel design of the laser speckle imaging system, which combines confocal illumination and detection with various speckle analysis methods. The system can be operated by three imaging modes. One is surface illumination laser speckle contrast imaging (SI-LSCI) and the other two are line scan temporal speckle contrast imaging (LS-TSCI) and line scan spatial speckle contrast imaging (LS-SSCI). The experimental results of flow phantoms have validated the mixture model, which combines the Lorentzian and Gaussian models to describe the simultaneous existence of both Brownian motions and ordered flow. Our experimental results of in vivo chick embryos demonstrate that LS-SSCI maintains high temporal resolution and is less affected by motion artifacts. LS-SSCI can provide better image quality for in vivo imaging blood chick embryos than LS-TSCI. Furthermore, the experiential results present that LS-SSCI can detect and quantify the blood flow change during vascular clipping, and shows great potential in diagnosing vascular diseases, such as angiosclerosis, angiostenosis, or angiemphraxis.

Panic behavior induces multiple endemic states and backward bifurcation

The aim of this paper is to investigate the effect of drastic behavioral changes on the dynamics of infectious diseases. An SIS model with two classes of individuals with different susceptibilities is analyzed. It focuses in a transition function between both classes of susceptible individuals depending on the density of the infected population. A classification of all the possible bifurcation diagrams that the model can present is done. Specifically, some conditions for the simultaneous existence of backward bifurcation and multiple endemic states are shown.

Quantised control for local Mittag–Leffler stabilisation of fractional‐order neural networks with input saturation: A refined sector condition

This brief focuses on the local Mittag–Leffler stabilisation of fractional-order neural networks via quantised control with input saturation. First, a refined sector condition is put forward, which can deal with the problem of the simultaneous existence of quantiser effect and actuator constraint. With the aid of refined sector condition, theoretical analysis on the local Mittag–Leffler stabilisation of the resulting closed-loop systems is carried out by using some inequality techniques on Mittag–Leffler function and fractional-order Lyapunov theory. In addition, two convex optimisation schemes are respectively developed to minimise the cost of actuators and to enlarge the admissible initial region. Finally, a three-neurons fractional-order neural networks is applied to illustrate the effectiveness of the derived results.

Characterization of Fault Signature Due to Combined Air-Gap Eccentricity and Rotor Faults in Induction Motors

An accurate means of non-invasive condition monitoring of the popular industrial drive, three-phase squirrel-cage induction motor, can help to avoid unscheduled maintenance downtime and loss. Faults like air-gap eccentricity can exist even in a newly assembled drive and hence may co-exist with other internal defects. Despite it being a possible situation, the occurrence of simultaneous faults has seldom been studied. Therefore, there is a need for identifying fault signatures of combined fault conditions in a non-invasive manner. This paper presents a detailed model-based study on a three-phase squirrel-cage induction motor with the simultaneous existence of broken rotor-bar and air-gap mixed eccentricity faults using spectral analysis of stator current, instantaneous power, and estimated air-gap torque signals. The modelling of the machine is done using the Multiple Coupled Circuit method and modified to model the presence of the combined fault conditions. A comparative evaluation with various fault conditions and their severity is carried out by spectral analysis, and unique slip-dependent frequency components are identified in the spectra of diagnostic signals. This fault characterization is the most significant contribution of this paper.

Problems and directions of improving the insurance of agricultural crops and plantings of perennial plantations against the risks of natural emergencies

The simultaneous existence of two interrelated forms of state aid - subsidizing classical agricultural insurance and compensation for damage to affected regions from the federal budget - requires understanding the basic principles of interaction and assessing the mutual impact of these areas of support. The purpose of the study is to identify the problems of the development of crop insurance and planting of perennial crops against the risks of natural emergencies. The research was carried out in the context of insurance statistics of Russian regions using generally accepted methods. The conducted research revealed the negative dynamics of a significant decrease in the volume of crop insurance of agricultural crops in 2016-2020. Regional authorities in the conditions of a single subsidy are not interested in the independent distribution of funds allocated by the state for the development of agricultural insurance. This is due to the fact that when the agricultural sector has significant losses as a result of the impact of natural disasters, the practice of introducing an emergency regime by the region is widespread. Which gives grounds for receiving compensation for half of the amount of damage directly from the federal budget. This determines the main problem of the development of classical agricultural insurance - the lack of expediency and material interest in this mechanism of protection of property interests both on the part of producers of agricultural products and on the part of regional authorities. In this regard, a brief justification was given for the feasibility of transforming the mechanism for providing direct assistance to the regions from the federal budget into a separate area of crop risk insurance in case of a natural emergency. This line of support will complete the classic multi-risk agricultural insurance.

“Consent Is F#@king Required”: Hashtag Feminism Surrounding Sexual Consent in a Culture of Postfeminist Contradictions

Hashtag feminism exists in a time of postfeminist contradictions marked by the simultaneous existence of popular feminism and popular misogyny. In one such contradiction, popular feminism has led women to expect the successful negotiation of sexual consent, while popular misogyny permits the circulation of traditional sexual scripts that disregard the necessity of consent. In this study, we analyze messages conveyed through digitized narratives of sexual consent posted on Tumblr, a social media site that is popular among feminist activists, to identify the ways that users construct meaning around the dissonance between expectations for consent and the inequalities that inhibit its negotiation. We specifically explore whether hashtag feminism navigates postfeminist contradictions in a way that simultaneously calls out misogyny and calls on feminism. We find that the Tumblr posts in our sample did both, albeit in a manner that failed to offer tangible solutions to the problem at hand. Calls on feminism were largely limited to tagging feminist allies and recirculating existing feminist campaigns. Thus, we argue that the hashtag ultimately became a handoff to a larger feminist abstraction. Future research should explore conditions under which activists link tangible issues, actors, and agendas to an otherwise abstract popular feminism.

Optical phonon mode assisted thermal conductivity in p-type ZrIrSb half-Heusler alloy: a combined experimental and computational study

Half-Heusler (HH) alloys with an 18 valence electron count have attracted significant interest in the area of research related to thermoelectrics (TEs). Understanding the novel transport properties exhibited by these systems with semiconducting ground state is an important focus area in this field. The large thermal conductivity shown by most of the HH alloys poses a major hurdle to improving the figure of merit (ZT). In addition, understanding the mechanism of thermal conduction in heavy-constituent HH alloys is an interesting aspect. Here, we have investigated the high-temperature TE properties of ZrIrSb through experimental studies, phonon dispersion and electronic band structure calculations. ZrIrSb is found to exhibit a substantially lower magnitude of resistivity and Seebeck coefficient near room temperature due to the existence of anti-site disorder between Ir/Sb and vacant sites. Interestingly, in ZrIrSb, lattice thermal conductivity is governed by a coupling between the acoustic and low-frequency optical phonon modes, which originates due to heavier Ir/Sb atoms. This coupling leads to an enhancement in the Umklapp processes due to the optical phonon excitations near the zone boundary, resulting in a lower magnitude of κ L. Our studies point to the fact that the simultaneous existence of two heavy mass elements within a simple unit cell can substantially decrease the lattice degrees of freedom.

Late medieval Vlachs in the western Balkans: orality, society and the limits of collective identities

This paper explores the social structures of late medieval Vlachs – particularly the ones inhabiting the Western Balkans (the Dinaric Alps) – in order to determine how collective identities were shaped and reproduced in medieval oral cultures. Southeast European historiographies have often portrayed the Balkan Vlachs as a unitary group and the label „Vlach” as representing a single, homogenous social entity during most of the Middle Ages. Still, social groups cannot exist and function without regular communication – oral or written – between their members. Oral cultures are based on verbal communication and are therefore bound by its specific nature, given that it requires continuous personal contact and oral transfer of information for communication and society to function properly. Literate cultures on the other hand tend to rely on written communication to a considerable extent and given that it allows for information to be conveyed impersonally (by text) its range is (at least in theory) almost limitless – as it is the level of (il)literacy that represents the main communicative and social limit in literate societies. Having in mind the abovementioned communicative and social limits of orality and the fact that it was the predominant if not exclusive form of communication among transhumant pastoralists such as the medieval Balkan Vlachs this paper argues that the range/scope of their group identities and collective identifications was rather limited. Furthermore, this paper discusses the types of collective identities utilized by Vlachs, questioning whether they ever shared a common „Vlach identity” given the fact that the social identity of the medieval people known as „the Vlachs” was primarily shaped and defined from the „outside” and „above” – by state intervention and a legal frame that was forced upon them. The Vlachs in the Medieval Balkans, and particularly in its western part, generally did not possess political authority and power, nor did they have the material resources and literary traditions allowing them to form more complex and enduring communication networks that would in turn have resulted in group identity formation on a larger scale. During the Early Middle Ages the Vlachs were „Vlachs” primarily because they were labelled as such and considered to be a distinct category of population by their Slavic (and later Byzantine) neighbours and overlords, and not necessarily because they originally defined themselves as such. This is not to say that gradually, during the course of the Middle Ages, the bearers of the „Vlach” name could not have started to identify themselves as „Vlachs” by accepting this foreign name (xenonym) as their preferred group name (autonym). Still, when this finally did happen it did not imply a „universal” Vlach identity in the medieval Balkans. Given the communicative limits of oral cultures as well as the Vlachs’ position as legal and political „objects” rather than „subjects” it seems most likely that the medieval Balkans witnessed a simultaneous existence of a multitude of „Vlachnesses” which were usually unrelated and unaware of each other.

Large direct and inverse electrocaloric effects in lead-free Dy doped 0.975KNN-0.025NBT ceramics

Undoped and Dy3+ doped 0.975 K1/2Na1/2NbO3-0.025Na1/2Bi1/2TiO3 (0.975KNN-0.025NBT) ceramics were synthesized using the solid-state synthesis method. X-ray diffraction analysis revealed pure perovskite structure without any secondary phases. The dielectric investigations of both ceramics revealed low dielectric losses in the dysprosium doped ceramic, particularly for temperatures higher than 100 °C. The dielectric loss anomaly around room temperature corroborates the polymorphic phase boundary (PPB) between orthorhombic and tetragonal phases detected by XRD investigations. The electrocaloric effect (ECE) was investigated using the indirect method based on the Maxwell equation and thermal P–E hysteresis loops. The maximum ECE value was found equal to 0.63 K at 83 °C for KNNBT0.025. However, in Dy doped KNNBT0.025 ceramics, both direct and inverse ECE responses were found with values of 1.01 K at 118 °C and −1.79 K at 80 °C, respectively. Besides, yellow light emission was detected under an excitation wavelength of 350 nm. The simultaneous existence of high ECEs, good dielectric performance, and photoluminescence properties makes KNNBT-Dy a promising candidate for solid-state refrigeration and optoelectronic devices.