A generalization of a Burridge-Knopoff spring-block model is investigated to illustrate the dynamics of transform faults. The model can undergo Hopf bifurcation and fold bifurcation of limit cycles. Considering the cyclical nature of the spring stiffness, the model with periodic perturbation is further explored via a continuation technique and numerical bifurcation analysis. It is shown that the periodic perturbation induces abundant dynamics, the existence, the switch, and the coexistence of multiple attractors including periodic solutions with various periods, (...) quasiperiodic solutions, chaotic solutions through torus destruction, or cascade of period doublings. Throughout the results obtained, one can see that the system manifests complex dynamical behaviors such as chaos, self-organized criticality, and the transition of dynamical behaviors when it comes to periodic perturbations. Even very small variation of a parameter can result in radical changes of the dynamics, which provides a new insight into the fault dynamics. (shrink)

Based on a nonlinear demand function and a market-clearing price, a cobweb model is introduced in this paper. A gradient mechanism that depends on the marginal profit is adopted to form the 1D discrete dynamic cobweb map. Analytical studies show that the map possesses four fixed points and only one attains the profit maximization. The stability/instability conditions for this fixed point are calculated and numerically studied. The numerical studies provide some insights about the cobweb map and confirm that this fixed (...) point can be destabilized due to period-doubling bifurcation. The second part of the paper discusses the memory factor on the stabilization of the map’s equilibrium point. A gradient mechanism that depends on the marginal profit in the past two time steps is adopted to incorporate memory in the model. Hence, a 2D discrete dynamic map is constructed. Through theoretical and numerical investigations, we show that the equilibrium point of the 2D map becomes unstable due to two types of bifurcations that are Neimark–Sacker and flip bifurcations. Furthermore, the influence of the speed of adjustment parameter on the map’s equilibrium is analyzed via numerical experiments. (shrink)

In this work, we introduce a new non-Shilnikov chaotic system with an infinite number of nonhyperbolic equilibrium points. The proposed system does not have any linear term, and it is worth noting that the new system has one equilibrium point with triple zero eigenvalues at the origin. Also, the novel system has an infinite number of equilibrium points with double zero eigenvalues that are located on the z -axis. Numerical analysis of the system reveals many strong dynamics. The new system (...) exhibits multistability and antimonotonicity. Multistability implies the coexistence of many periodic, limit cycle, and chaotic attractors under different initial values. Also, bifurcation analysis of the system shows interesting phenomena such as periodic window, period-doubling route to chaos, and inverse period-doubling bifurcations. Moreover, the complexity of the system is analyzed by computing spectral entropy. The spectral entropy distribution under different initial values is very scattered and shows that the new system has numerous multiple attractors. Finally, chaos-based encoding/decoding algorithms for secure data transmission are developed by designing a state chain diagram, which indicates the applicability of the new chaotic system. (shrink)

This paper presents the nonlinear dynamic analysis of energy-based models arisen from the applied systems characterized by the energy transport in the presence of fractional order derivative and time delay. The studied model is the fractional version of Bianca-Ferrara-Dalgaard-Strulik model of economy which is viewed as a transport network for energy in which the law of motion of capital occurs. By considering the time delay as bifurcation parameter, a proof to investigate the existence of Hopf bifurcation and the (...) phase lock solutions using the Poincare-Linstedt and the harmonic balance methods is given. At definite values of time delay, period-doubling bifurcations followed up by the consequences of chaotic states are detected. Simulation results assure that the BFDS model can generate new chaotic attractors beyond half order derivatives through the effect of the time delay on that system. In accordance with the literatures related to the problem of chaos, the concluded results confirm the proposed theorem by El-Borhamy in which the time delay possesses the ability to change the dynamic state of nonlinear systems from regular to chaotic within the fractional order derivative domain. (shrink)

We investigate the isochronous bifurcations of the straight-line librating orbit in the Hénon–Heiles and related potentials. With increasing scaled energy e, they form a cascade of pitchfork bifurcations that cumulate at the critical saddle-point energy e=1. The stable and unstable orbits created at these bifurcations appear in two sequences whose self-similar properties possess an analytical scaling behavior. Different from the standard Feigenbaum scenario in area preserving two-dimensional maps, here the scaling constants α and β corresponding to the two spatial directions (...) are identical and equal to the root of the scaling constant δ that describes the geometric progression of bifurcation energies en in the limit n→∞. The value of δ is given analytically in terms of the potential parameters. (shrink)

In this paper, a discrete-time dynamic duopoly model, with nonlinear demand and cost functions, is established. The properties of existence and local stability of equilibrium points have been verified and analyzed. The stability conditions are also given with the help of the Jury criterion. With changing of the values of parameters, the system shows some new and interesting phenomena in terms to stability and multistability, such as V-shaped stable structures and different shape basins of attraction of coexisting attractors. The eye-shaped (...) structures appear where the period-doubling and period-halving bifurcations occur. Finally, by utilizing critical curves, the changes in the topological structure of basin of attraction and the reason of “holes” formation are analyzed. As a result, the generation of global bifurcation, such as contact bifurcation or final bifurcation, is usually accompanied by the contact of critical curves and boundary. (shrink)

In this study, complex dynamics of Briggs–Rauscher reaction system is investigated analytically and numerically. First, the Briggs–Rauscher reaction system is reduced into a new nonlinear parametric oscillator. The Melnikov method is used to derive the condition of the appearance of horseshoe chaos in the cases ω = Ω and ω ≠ Ω. The performed numerical simulations confirm the obtained analytical predictions. Second, the prediction of coexisting attractors is investigated by solving numerically the new nonlinear parametric ordinary differential equation via the (...) fourth-order Runge–Kutta algorithm. As results, it is found that the new nonlinear chemical system displays various coexisting behaviors of symmetric and asymmetric attractors. In addition, the system presents a rich variety of bifurcations phenomena such as symmetry breaking, symmetry restoring, period doubling, reverse period doubling, period-m bubbles, reverse period-m bubbles, intermittency, and antimonotonicity. On the contrary, emerging chaotic band attractors and period-1, period-3, period-9, and period-m bubbles routes to chaos occur in this system. (shrink)

Demarcation of elements for two subsets appears to be the most fundamental approach to their classification. If one draws a vertical straight line through the middle of each block of elements in the Periodic table, all the elements are divided into two subsets: “early” and “later”. For example, in the d-block, the early ones are Sc–Mn, and the late ones, respectively, are Fe–Zn. Later elements partially repeat the properties of the early ones, and this is defined as the internal periodicity. (...) Another criterion for dividing the elements into two subsets is the evenness and oddness of the sum of n + l, where n is the principal quantum number, and l is the orbital quantum number for the outer electron subshells. Properties of the odd elements are closer to each other than to properties of even elements, and vice versa. This regularity is manifested as the secondary periodicity. The history of concepts, which considered the existence of subsets as well as of inner and secondary periodicities, is discussed. The features of the electronic structure, which underlie the existence of subsets, are considered. The existence of subsets was depicted earlier by dividing the periodic table into two tables or by applying a mirror-symmetric table. Small changes are proposed in the conventional Periodic table, allowing to reflect the existence of the considered subsets. (shrink)

Demarcation of elements for two subsets appears to be the most fundamental approach to their classification. If one draws a vertical straight line through the middle of each block of elements in the Periodic table, all the elements are divided into two subsets: “early” and “later”. For example, in the d-block, the early ones are Sc–Mn, and the late ones, respectively, are Fe–Zn. Later elements partially repeat the properties of the early ones, and this is defined as the internal periodicity. (...) Another criterion for dividing the elements into two subsets is the evenness and oddness of the sum of n + l, where n is the principal quantum number, and l is the orbital quantum number for the outer electron subshells. Properties of the odd elements are closer to each other than to properties of even elements, and vice versa. This regularity is manifested as the secondary periodicity. The history of concepts, which considered the existence of subsets as well as of inner and secondary periodicities, is discussed. The features of the electronic structure, which underlie the existence of subsets, are considered. The existence of subsets was depicted earlier by dividing the periodic table into two tables or by applying a mirror-symmetric table. Small changes are proposed in the conventional Periodic table, allowing to reflect the existence of the considered subsets. (shrink)

In this paper, a finance system with delay is considered. By analyzing the corresponding characteristic equations, the local stability of equilibrium is established. The existence of Hopf bifurcations at the equilibrium is also discussed. Furthermore, formulas for determining the direction of Hopf bifurcation and the stability of the bifurcating periodic solutions are derived by applying the normal form method and center manifold theorem. Finally, numerical simulation results are presented to validate the theoretical analysis. Numerical simulation results show that delay (...) can lead a stable system into a chaotic state. (shrink)

When reasoning about dependence relations, philosophers often rely on gradualist assumptions, according to which abrupt changes in a phenomenon of interest can only result from abrupt changes in the low-level phenomena on which it depends. These assumptions, while strictly correct if the dependence relation in question can be expressed by continuous dynamical equations, should be handled with care: very often the descriptively relevant property of a dynamical system connecting high- and low-level phenomena is not its instantaneous behavior, but its stable (...) fixed points (those in the vicinity of which it spends most of the time, after comparatively short transitory periods), and stable fixed points can change abruptly as a result of infinitesimal changes of the low-level phenomenon. We illustrate this potential gradualist trap by showing that Chalmers’s fading qualia argument falls in it. (shrink)

Neurons encode and transmit signals through chemical synaptic or electrical synaptic connections in the actual nervous system. Exploring the biophysical properties of coupling channels is of great significance for further understanding the rhythm transitions of neural network electrical activity patterns and preventing neurological diseases. From the perspective of biophysics, the activation of magnetic field coupling is the result of the continuous release and propagation of intracellular and extracellular ions, which is very similar to the activation of chemical synaptic coupling through (...) the continuous release of neurotransmitters. In this article, an induction coil is used to connect two HR neurons to stimulate the effect of magnetic field coupling. It is inevitable that time delays can affect the coupling process in the transmission of information, and it should be considered in the coupled model. Firstly, the firing characteristics and bifurcation modes of two coupled HR neurons are studied by using one parameter and two parameters bifurcation. With the increase of propagation delay and coupling gain, the chaotic state of neurons disappears and the high-period window decreases due to the influence of energy transfer between neurons. Then, the synchronization patterns of two HR neurons with different stimulation are analyzed by error diagrams and time series diagrams. It is confirmed that the synchronous pattern has certain regularity and is related not only to the neurons with large stimulation current but also to the time delay and coupling gain. The research conclusions of this article will provide the corresponding theoretical basis for medical experiments. (shrink)

Chaos in nervous system is a fascinating but controversial field of investigation. To approach the role of chaos in the real brain, we theoretically and numerically investigate the occurrence of chaos inartificial neural networks. Most of the time, recurrent networks (with feedbacks) are fully connected. This architecture being not biologically plausible, the occurrence of chaos is studied here for a randomly diluted architecture. By normalizing the variance of synaptic weights, we produce a bifurcation parameter, dependent on this variance and (...) on the slope of the transfer function, that allows a sustained activity and the occurrence of chaos when reaching a critical value. Even for weak connectivity and small size, we find numerical results in accordance with the theoretical ones previously established for fully connected infinite sized networks. The route towards chaos is numerically checked to be a quasi-periodic one, whatever the type of the first bifurcation is. Our results suggest that such high-dimensional networks behave like low-dimensional dynamical systems. (shrink)

The dynamical behaviour of a very general model of neural networks with random asymmetric synaptic weights is investigated in the presence of random thresholds. Using mean-field equations, the bifurcations of the fixed points and the change of regime when varying control parameters are established. Different areas with various regimes are defined in the parameter space. Chaos arises generically by a quasi-periodicity route.

Les trajectoires d’entrée dans la vie adulte sont parsemées d’événements, de périodes de crise, de carrefours biographiques devant lesquels les jeunes sont amenés à réagir, à faire des choix et à opérer parfois un changement brutal dans leur parcours. Dans ces moments de crise, de basculement et de réalisation de l’improbable, se révèlent des enjeux et des logiques de choix qui resteraient invisibles dans le cours tranquille des choses.À partir d’une enquête qualitative longitudinale auprès d’un panel de jeunes, je propose (...) ici une tentative d’exploration de la notion de bifurcation. Les récits et les argumentaires développés permettent d’identifier les « ingrédients » mobilisés dans la prise de décision. Sont parcourus là divers registres structurels, contextuels, relationnels et individuels, ainsi que des temporalités diverses en interaction. C’est peut-être justement leur conjonction qui autorise cette « rupture » de l’ordre social attendu.The trajectories of entry into adulthood are cluttered with events, periods of crisis, life crossroads to which young people have to face up, to make choices and sometimes operate radical changes in the course of their lives. In these moments of crisis, upheavals and unexpected turning points, new stakes and logics of orientation appear, which would have remained unseen in a quieter course of things.Working from a qualitative longitudinal survey of a panel of young people, this paper offers an attempt to explore the notion of bifurcation. The life stories and the arguments these young people developed allow to identify the components of choice-making. Various structural, topical, relational and individual registers have been identified, along with various interacting temporalities. It is their conjunction that is likely to make possible a breaking up of the expected social order. (shrink)

Direct Informational Semantics, according to which [X]s represent X if ‘Xs cause [X]s’ is a law, and Fodorian naturalistic semantics both suffer from double disjunctivitis. I argue that robustness, properly construed, characterizes both represented properties and representing symbols: two or more properties normally regarded as non-disjunctive may each be nomologically connected to a non-disjunctive symbol, and two or more non-disjunctive symbols may each be nomologically connected to a property. This kind of robustness bifurcates the so-called disjunction problem into a Represented-Disjunction (...) Problem, of which Fodor was aware, and a Representer-Disjunction Problem, of which he was on the whole oblivious. Fodor fails to solve these problems: his solution to the former, the Asymmetric Dependence Condition, presupposes a successful solution to the latter, while possible responses that Fodor might make to the latter either beg the former or cannot be met or else flout the Naturalistic Requirement and the Atomistic Requirement. Even setting the Representer-Disjunction Problem aside, the Represented-Disjunction Problem does not get solved, because the robustness involving phonological/orthographic sequences guarantees that nothing can meet the Asymmetrical Dependence Condition. Indeed there is a serious problem of individuating phonological/orthographic tokens and types in a manner that satisfies Fodor’s expectations. This is made manifest by the presence of orthographic tokens embedded in larger tokens. (shrink)

Spatially and temporally restricted expression of Hox genes requires multiple mechanisms at both the transcriptional and the post-transcriptional levels. New insight into this precise expression mechanism comes from recent findings of a novel sense–antisense miRNA combination from the bithorax complex of Drosophila melanogaster.1-4 These two miRNAs encoded from the same locus target 3′ untranslated regions of anterior hox genes, Antp, Ubx and abd-A to establish the dominance of posterior hox gene Abd-B in its expression domain. Such double-edge tools, sense–antisense miRNA (...) combinations, also operate at multiple loci in the genome implicating their wider impact on the post-transcriptional gene regulation in eukaryotes. BioEssays 30:1058–1061, 2008. © 2008 Wiley Periodicals, Inc. (shrink)

Interwar Japan saw the rise of a generation of intellectuals, bureaucrats, and educators who were uneasy about modern life. One expression of this malaise was the introduction of calligraphy in the 1941 and 1943 school curricula. Calligraphy injected aesthetics into writing education. Yet it also compromised the speed and efficiency of writing, which lay at the core of Japan's system of modern education. The solution was to teach writing twice, once as an art in the `art section' and once as (...) a functional skill in the `language section'. As an art, writing was a means to cultivate the spirit, discipline the body, escape from the calculated logic of linear time and produce an aesthetic epiphany. As a functional tool, it was a skill for keeping pace with the demands of the modern world by communicating meaning quickly and efficiently. Bureaucrats and educators from 1941 were thus simultaneously engaged in the task of overcoming modernity on the one hand and of instilling proficiency in modern life on the other. This duality of the word as a functional code for transmitting meaning and the word as an aesthetic form both echoed and shaped the double nature of Japan's modernity. (shrink)

Interwar Japan saw the rise of a generation of intellectuals, bureaucrats, and educators who were uneasy about modern life. One expression of this malaise was the introduction of calligraphy in the 1941 and 1943 school curricula. Calligraphy injected aesthetics into writing education. Yet it also compromised the speed and efficiency of writing, which lay at the core of Japan's system of modern education. The solution was to teach writing twice, once as an art in the `art section' and once as (...) a functional skill in the `language section'. As an art, writing was a means to cultivate the spirit, discipline the body, escape from the calculated logic of linear time and produce an aesthetic epiphany. As a functional tool, it was a skill for keeping pace with the demands of the modern world by communicating meaning quickly and efficiently. Bureaucrats and educators from 1941 were thus simultaneously engaged in the task of overcoming modernity on the one hand and of instilling proficiency in modern life on the other. This duality of the word as a functional code for transmitting meaning and the word as an aesthetic form both echoed and shaped the double nature of Japan's modernity. (shrink)

The corpus of late antique Babylonian incantation bowls comprises a class of double-bowl sets, consisting of two bowls facing each other, fastened together with bitumen. Occasionally, such bowl sets have been found to contain inscribed egg shells or human bones. The double-bowl configuration is highly reminiscent of the double-jar burial practice attested in Mesopotamia from the second millennium to the sixth century BCE. The double-jar burial involved placing the deceased between two wide-mouthed jars, occasionally joining them with bitumen at the (...) rims. This article explores the double-bowl configuration and suggests a connection between double-jar burials and the later ritual artifacts of the Sasanian period. The double-bowl sets attached with bitumen may have originated on analogy to the ancient burial practice, intending symbolically to bury evil entities or human adversaries. (shrink)

ABSTRACT Born in periods of crises, utopias adopt a threefold structure: a critique of society, a spatial arrangement, and a new society sustained by this spatial arrangement. Accordingly, space and architecture are recognized as spatial levers to address crises and change societies. However, three problematic characteristics emerge from an analysis of past and contemporary utopias. First, utopias do not always advocate for new societal orders, as some tend to consolidate the existing ones. Second, they have evolved to be increasingly tangible. (...) Third, while appearing as collective narratives, they are written by a single hand, allowing little variations. To address these issues and revitalize their critical potency, utopias could act as beacons rather than concrete projects, work on processes rather than goals, and build collective narratives rather than monologues. Eventually, the article illustrates architecture’s twofold rationale: a means to physically build space and a critical tool to reflect on society. (shrink)

This paper describes the construction of the Periodic Tables for cations of all elements with charges + 1, + 2, + 3 and anions with charge − 1. The Table for cations+1 differs significantly from other newly constructed Tables and from known Tables, as the d- and f-blocks are inserted into s-block and split it up for two parts. Importantly, a new type of 3d- and 4f-shell contractions has been discovered. The manifestations of secondary periodicity in case of anions is (...) absent or opposite to the manifestations observed for atoms and cations. For kainosymmetric anions, the ionization energies are lowered, which contradicts the theoretical assumptions and experimental data supporting the classical concept of kainosymmetry. Simple formulas are proposed for quantitative description of the manifestations of internal periodicity and kainosymmetry. The regularities of change in these manifestations depending on the charge and the position of ions or atoms in the Periodic Table are established. In the 6th period, the bifurcation in the properties characteristic of the internal periodicity does not occur at usual position, i.e. in the middle of the row from the block of the Periodic Table, but takes place earlier, along with the transition of the electronic configurations p2–p3. In other words, the place of transition from "early" to "late" elements changes. (shrink)

DNA double‐strand breaks (DSBs) are extremely hazardous lesions for all DNA‐bearing organisms and the mechanisms of DSB repair are highly conserved. In the eukaryotic mitotic cell cycle, DSBs are often present following DNA replication while, in meiosis, hundreds of DSBs are generated as a prelude to the reshuffling of the maternally and paternally derived genomes. In both cases, the DSBs are repaired by a process called homologous recombinational repair (HRR), which utilises an intact DNA molecule as the repair template. Mitotic (...) and meiotic HRR are managed by ‘checkpoints’ that inhibit cell division until DSB repair is complete. Here we attempt to summarise the substantial recent progress in understanding the checkpoint management of HRR in mitosis (focussing mainly on mammals) and then go on to use this information as a framework for understanding the presumed checkpoint management of HRR in mammalian meiosis. BioEssays 29:974–986, 2007. © 2007 Wiley Periodicals, Inc. (shrink)

The core of this article is a comparative analysis of the double movement of the late nineteenth and early twentieth century with the double movement of the late twentieth and early twenty-first century. In both periods the movement toward allegedly self-regulating markets called forth a countermovement of protection. Nevertheless, important differences exist due, first, to differences in the nature of the hegemonic state and, second, to the greater role of subordinate forces in constraining the movement toward self-regulating markets in the (...) late twentieth century. (shrink)

At the heart of chemistry lies the periodic system of chemical elements. Despite being the cornerstone of modern chemistry, the overall structure of the periodic system has never been fully understood from an atomic physics point of view. Group-theoretical models have been proposed instead, but they suffer from several limitations. Among others, the identification of the correct symmetry group and its decomposition into subgroups has remained a problem to this day. In an effort to deepen our limited understanding of the (...) periodic law, we have extended the traditional Lie algebraic framework to account for the peculiar degeneracy structure of the periodic system. Starting from the four-dimensional hidden symmetry and accidental degeneracy of the hydrogen atom, as first revealed by Fock in 1935, our research has mainly focussed on the way this SO(4) symmetry of the Coulomb potential gets broken in the periodic system as a consequence of the transformation of the hydrogenic (n, l) filling order to the Madelung (n+l, n) order due to electronic repulsions, relativistic effects and spin-orbit couplings. In this PhD dissertation, a new left-step format of the periodic table is first proposed on the basis of the Madelung rule. Following the particle physics tradition, the chemical elements are then considered as various states of some 'atomic matter', which is described by a non-compact spectrum-generating dynamical Lie group. The chemical elements are shown to form a basis for a single infinite-dimensional degeneracy space of the SO(4,2) ⊗ SU(2) group. An explanation for the period doubling is then proposed in terms of a particular symmetry breaking of the SO(4,2) group to the anti de Sitter SO(3,2) group. The Madelung rule is rationalised on the basis of nonlinear Lie algebras which reflect the screening of the Coulomb hole. This opens new perspectives for a symmetry-based understanding of how the periodic law emerges from its quantum mechanical foundations, and holds the future promise of complementing our current phenomenological approach by a direct atomic physics approach. (shrink)

The psychoanalytical case history was in many ways the pivot point of John Forrester’s reflections on case-based reasoning. Yet the Freudian case is not without its own textual forebears. This article closely analyses texts from two earlier case-writing traditions in order to elucidate some of the negotiations by which the case history as a textual form came to articulate the mode of reasoning that we now call ‘thinking in cases’. It reads Eugène Azam’s 1876 observation of Félida X and her (...) ‘double personality’—the case that brought both Azam and Félida to prominence in late 19th-century French science—against a medico-surgical case penned by the Bordeaux physician in the same decade. While the stylistics of Azam’s medical case mirror its epistemic underpinnings in the ‘vertical’ logics of positivist science, the multiple narratives interwoven in Félida’s case grant both Azam and his patient the role of knowledge-making actors in the text. This narrative transformation chimes with the way Azam reasons ‘horizontally’ from particulars to Félida’s singular condition, but sits in tension with his choice to structure the observation along a ‘vertical’ axis. Between the two, we glimpse the emergence of the psychological observation as a mode of writing and thus of thinking in cases. (shrink)

Many kinds of multifunctional regulatory proteins have been identified that perform distinct biochemical functions in the nucleus, the cytoplasm, or both. Here we describe the recent discovery by Hall et al. (2004)1 of a new type of multifunctional protein: a metabolic enzyme that doubles as a transcription factor. This enzyme, Arg5,6, functions as a catalytic enzyme in ornithine biosynthesis and also binds and regulates the promoters of nuclear and mitochondrial genes. It may also regulate precursor mRNA metabolism. We discuss how (...) proteins that serve as both metabolic enzymes and transcription factors might have evolved. BioEssays 27:467–471, 2005. © 2005 Wiley Periodicals, Inc. (shrink)

Kafka's writings are frequently interpreted as representing the historical period of modernism in which he was writing. Little attention has been paid, however, to the possibility that his writings may reflect neural mechanisms in the processing of self during hypnagogic (i.e., between waking and sleep) states. Kafka suffered from dream-like, hypnagogic hallucinations during a sleep-deprived state while writing. This paper discusses reasons (phenomenological and neurobiological) why the self projects an imaginary double (autoscopy) in its spontaneous hallucinations and how Kafka's (...) writings help to elucidate the underlying cognitive and neural mechanisms. I further discuss how the proposed mechanisms may be relevant to understanding paranoid delusions in schizophrenia. Literature documents and records cognitive and neural processes of self with an intimacy that may be otherwise unavailable to neuroscience. To elucidate this approach, I contrast it with the apparently popularizing view that the symptoms of schizophrenia result from what has been called an operative (i.e., pre-reflective) hyper-reflexivity. The latter approach claims that pre-reflective self-awareness (diminished in schizophrenia) pervades all conscious experience (however, in a manner that remains unverifiable for both phenomenological and experimental methods). This contribution argues the opposite: the. (shrink)

The phenomena, molecular path in a liquid or a gas, fluctuating price stoke, fission and fusion, quantum field theory, relativistic wave motion, etc., are modeled through the nonlinear time fractional clannish random Walker’s parabolic equation, nonlinear time fractional SharmaTassoOlver equation, and the nonlinear space-time fractional KleinGordon equation. The fractional derivative is described in the sense of conformable derivative. From there, the G ′ / G, 1 / G -expansion method is found to be ensuing, effective, and capable to provide functional (...) solutions to nonlinear models concerning physical and engineering problems. In this study, an extension of the G ′ / G, 1 / G -expansion method has been introduced. This enhancement establishes broad-ranging and adequate fresh solutions. In addition, some existing solutions attainable in the literature also confirm the validity of the suggested extension. We believe that the extension might be added to the literature as a reliable and efficient technique to examine a wide variety of nonlinear fractional systems with parameters including solitary and periodic wave solutions to nonlinear FDEs. (shrink)

The hardest part of replicating a genome is the beginning. The first step of DNA replication (called “initiation”) mobilizes a large number of specialized proteins (“initiators”) that recognize specific sequences or structural motifs in the DNA, unwind the double helix, protect the exposed ssDNA, and recruit the enzymatic activities required for DNA synthesis, such as helicases, primases and polymerases. All of these components are orderly assembled before the first nucleotide can be incorporated. On the occasion of the 50th anniversary of (...) the discovery of the DNA structure, we review our current knowledge of the molecular mechanisms that control initiation of DNA replication in eukaryotic cells, with particular emphasis on the recent identification of novel initiator proteins. We speculate how these initiators assemble molecular machines capable of performing specific biochemical tasks, such as loading a ring‐shaped helicase onto the DNA double helix. BioEssays 25:1158–1167, 2003. © 2003 Wiley Periodicals, Inc. (shrink)

The two waves of COVID-19 in India have had severe consequences for the lives of people. The Indian State-imposed various regulatory mechanisms like lockdowns, encouraged remote work, online teaching in academic institutions, and enforced adherence to the COVID protocols. The use of various technologies especially digital/online technologies not only helped to adapt to the “new normal” and cope with the disruptions in pursuing everyday activities but also to manage one’s well-being. However, the availability and accessibility of digital technologies to various (...) sections of the population were not uniform. This paper reports a series of three studies examining the nature of pandemic stress, the impact of technology use on people’s emotional well-being during turbulent times, and the effects of technology use on psychological resources like resilience, self-efficacy, motivation to work, and emotional well-being. The differences in the residential background and SES in the extent of the use of technology and strength of psychological resources were assessed. The findings indicated that the most common causes of concern included worrying about family, friends, partners, fears of getting and giving the viral infection to someone; frustration and or boredom; and changes in normal sleep patterns. It was noted that technology was a double-edged sword and created barriers as well as opportunities for the people. Also, self-efficacy mediated the relationship between the use of technology and emotional wellbeing. The results have policy implications for building resilient communities in the post COVID period. (shrink)

A double delayed hybrid stochastic prey-predator bioeconomic system with Lévy jumps is established and analyzed, where commercial harvesting on prey and environmental stochasticity on population dynamics are considered. Two discrete time delays are utilized to represent the maturation delay of prey and gestation delay of predator, respectively. For a deterministic system, positivity of solutions and uniform persistence of system are discussed. Some sufficient conditions associated with double time delays are derived to discuss asymptotic stability of interior equilibrium. For a stochastic (...) system, existence and uniqueness of a global positive solution are studied. By using the invariant measure theory and singular boundary theory of diffusion process, existence of stochastic Hopf bifurcation and stochastic stability are investigated. By constructing appropriate Lyapunov functions, asymptotic dynamic behavior of the proposed hybrid stochastic system with double time delays and Lévy jumps is discussed. Numerical simulations are provided to show consistency with theoretical analysis. (shrink)

The numerical study of a glycolytic model formed by a system of three delay differential equations reveals a multiplicity of stable coexisting states: birhythmicity, trirhythmicity, hard excitation and quasiperiodic with chaotic regimes. For different initial functions in the phase space one may observe the coexistence of two different quasiperiodic motions, the existence of a stable steady state with a stable torus, and the existence of a strange attractor with different stable regimes (chaos with torus, chaos with bursting motion, and chaos (...) with different periodic regimes). For a single range of the control parameter values our system may exhibit different bifurcation diagrams: in one case a Feigenbaum route to chaos coexists with a finite number of successive periodic bifurcations, in other conditions it is possible to observe the coexistence of two quasiperiodicity routes to chaos. These studies were obtained both at constant input flux and under forcing conditions. (shrink)

In this article we analyze Georg Büchner’s tragedy ‘Danton’s Death‘ on the basis of implementation of double idealization principle as meaning- and structure-forming item of the text. It is proved that the principle of double idealization is connected with the antiquity; from the one hand, Ancient Greece comes out as a self-sufficient timeless ideal, opposed to the temporal ideal of Ancient Rome in the Republic period; on the other hand, the double idealization principle can be considered as a method (...) applied during the formation of the new (in the historical context) ideal. However, in the world - which is interpreted by the dramaturge as the supremacy of chaos and fatalism of history, antiquity is once again is a constant point, from which the motion can start. (shrink)

Afrocentrism. Eurocentrism. Caribbean Studies. British Studies. To the forces of cultural nationalism hunkered down in their camps, this bold hook sounds a liberating call. There is, Paul Gilroy tells us, a culture that is not specifically African, American, Caribbean, or British, but all of these at once, a black Atlantic culture whose themes and techniques transcend ethnicity and nationality to produce something new and, until now, unremarked. Challenging the practices and assumptions of cultural studies, The Black Atlantic also complicates and (...) enriches our understanding of modernism. Debates about postmodernism have cast an unfashionable pall over questions of historical periodization. Gilroy bucks this trend by arguing that the development of black culture in the Americas arid Europe is a historical experience which can be called modern for a number of clear and specific reasons. For Hegel, the dialectic of master and slave was integral to modernity, and Gilroy considers the implications of this idea for a transatlantic culture. In search of a poetics reflecting the politics and history of this culture, he takes us on a transatlantic tour of the music that, for centuries, has transmitted racial messages and feeling around the world, from the Jubilee Singers in the nineteenth century to Jimi Hendrix to rap. He also explores this internationalism as it is manifested in black writing from the "double consciousness" of W. E. B. Du Bois to the "double vision" of Richard Wright to the compelling voice of Toni Morrison. In a final tour de force, Gilroy exposes the shared contours of black and Jewish concepts of diaspora in order both to establish a theoretical basis for healing rifts between blacks and Jews in contemporary culture and to further define the central theme of his book: that blacks have shaped a nationalism, if not a nation, within the shared culture of the black Atlantic. (shrink)

To this day, a hundred and fifty years after Mendeleev's discovery, the overal structure of the periodic system remains unaccounted for in quantum-mechanical terms. Given this dire situation, a handful of scientists in the 1970s embarked on a quest for the symmetries that lie hidden in the periodic table. Their goal was to explain the table's structure in group-theoretical terms. We argue that this symmetry program required an important paradigm shift in the understanding of the nature of chemical elements. The (...) idea, in essence, consisted of treating the chemical elements, not as particles, but as states of a superparticle. We show that the inspiration for this came from elementary particle physics, and in particular from Heisenberg's suggestion to treat the proton and neutron as different states of the nucleon. We provide a careful study of Heisenberg's last paper on the nature of elementary particles, and explain why the Democritean picture of matter no longer applied in modern physics and a Platonic symmetry-based picture was called for instead. We show how Heisenberg's Platonic philosophy came to dominate the field of elementary particle physics, and how it found its culmination point in Gell-Mann's classification of the hadrons in the eightfold way. We argue that it was the success of Heisenberg's approach in elementary particle physics that sparked the group-theoretical approach to the periodic table. We explain how it was applied to the set of chemical elements via a critical examination of the work of the Russian mathematician Abram Ilyich Fet the Turkish-American physicist Asim Orhan Barut, before giving some final reflections. (shrink)

We investigate the dynamics of a nonautonomous stochastic SIS epidemic model with nonlinear incidence rate and double epidemic hypothesis. By constructing suitable stochastic Lyapunov functions and using Has’minskii theory, we prove that there exists at least one nontrivial positive periodic solution of the system. Moreover, the sufficient conditions for extinction of the disease are obtained by using the theory of nonautonomous stochastic differential equations. Finally, numerical simulations are utilized to illustrate our theoretical analysis.

In the Periodic Tables the transition from atoms to double-charged cations is accompanied by alterations in the composition of s and p blocks and reciprocal location of blocks, as well as by changes in the composition and length of periods. We have previously described the relationship between the atom properties and the total number of differentiating electrons. This paper demonstrates that, despite the above transition-related alterations, this relationship is also valid for the description of the properties of double-charged cations. This (...) can be exemplified by the dependence of the ionization energy on the total number of p electrons in p block, d electrons in d block, and f electrons in f block. Furthermore, a single periodic equation is sufficient for the description of properties of all of double-charged cations from each block. (shrink)

To describe and analyze the unstable periodic orbits of the Rucklidge system, a so-called symbolic encoding method is introduced, which has been proven to be an efficient tool to explore the topological properties concealed in these periodic orbits. In this work, the unstable periodic orbits up to a certain topological length in the Rucklidge system are systematically investigated via a proposed variational method. The dynamics in the Rucklidge system are explored by using phase portrait analysis, Lyapunov exponents, and Poincaré first (...) return maps. Symbolic encodings of the periodic orbits with two and four letters based on the trajectory topology in the phase space are implemented under two sets of parameter values. Meanwhile, the bifurcations of the periodic orbits are explored, significantly improving the understanding of the dynamics of the Rucklidge system. The multiple-letter symbolic encoding method could also be applicable to other nonlinear dynamical systems. (shrink)

In lieu of an abstract, here is a brief excerpt of the content:Philosophy and Rhetoric 34.4 (2001) 292-307 [Access article in PDF] The Rhetoric of the Geometrical Method Spinoza's Double Strategy Christopher P. Long A double strategy may be apprehended in the first definitions, axioms and propositions of Spinoza's Ethics: the one is rhetorical, the other, systematic. Insofar as these opening passages constitute a geometrical argument that leads ultimately to the strict monism that lies at the heart of Spinoza's philosophy, (...) they function systematically as grounding principles. However, insofar as they are designed to uncover errors at the heart of the Cartesian system, they function rhetorically as a critique of Descartes's equivocal theory of substance. The geometrical mode of presentation lends an aura of necessity to the systematic strategy and tends to eclipse the rhetorical strategy that functions as a critique of Cartesian dualism. 1 To this extent, the systematic strategy itself functions rhetorically. On the other hand, to the extent that any seventeenth-century attempt to establish a monistic system would inevitably have had to involve a critique of Cartesian dualism, the rhetorical strategy itself functions systematically. Thus, although two distinct strategies are simultaneously discernible in the opening passages of the Ethics, the two work together, each arguing on a different front, to establish Spinoza's monism. By focusing on the rhetorical side of this double strategy, the underlying nature of Spinoza's critique of Descartes can be clarified and certain gaps in the systematic, geometrical argument for monism can be explained. Descartes's theory of substance The rhetorical strategy Spinoza employs at the outset of the Ethics involves a brilliant use of equivocation and ambiguity designed to draw a reader dedicated to Cartesian dualism into the heart of an argument designed to [End Page 292] undermine this dualism itself. The impetus behind this rhetorical critique is surely Spinoza's dissatisfaction with Descartes's theory of substance. 1. Descartes's equivocation Descartes's theory rests upon a fundamental equivocation: on the one hand, the term "substance" is meant strictly to designate that which is absolutely self-sufficient, namely, God; on the other hand, Descartes allows for a weaker understanding of substance, which pertains to those things (specifically res cogitans and res extensa) that require only the concurrence of God in order to exist (Principles I, 51-52; AT VIIIA24-25). 2 Thus, for Descartes, although God is, strictly speaking, the only substance, there remains a sense in which both res cogitans and res extensa may be understood as substances as well.Ultimately, this equivocal understanding of substance may be traced to a tension internal to Descartes between the Aristotelian notion of substance as underlying subject and the seventeenth-century mutation of that notion, which came to be defined in terms of causal self-sufficiency. 3 Jonathan Bennett traces the source of this mutation back to the view held by Aristotle that the existence of some property depends upon its being instantiated--that is, there can be no courage unless there exists someone courageous. He continues his interesting argument thus: This suggests that there is a relation of dependence running from properties to the things that have them and not conversely. The dependence would be logical: the thesis must be that "existent but uninstantiated property" is conceptually defective, not merely contrary to physics. Thus, one mark of a genuine thing, or substance, is its not being logically dependent for its existence on anything else. (Bennett 1984, 56) The development of this line of thinking leads to the conception of substance we find both in Descartes's Principles and in Spinoza's Ethics, namely, that a substance must not causally depend on anything outside of itself for its existence. 4 However, with Descartes, what emerges out of this tradition is a hybrid understanding of substance in which the term "substance" is not reserved simply for that which is utterly self-sufficient (God), but extends to those things that depend only upon the concurrence of God for their existence (rescogitans and resextensa). This bifurcated understanding of substance seems to stem from the distinction at work in [End Page 293] Aristotle... (shrink)

Contemporary debates about scientific institutions and practice feature many proposed reforms. Most of these require increased efforts from scientists. But how do scientists’ incentives for effort interact? How can scientific institutions encourage scientists to invest effort in research? We explore these questions using a game-theoretic model of publication markets. We employ a base game between authors and reviewers, before assessing some of its tendencies by means of analysis and simulations. We compare how the effort expenditures of these groups interact in (...) our model under a variety of settings, such as double-blind and open review systems. We make a number of findings, including that open review can increase the effort of authors in a range of circumstances and that these effects can manifest in a policy-relevant period of time. However, we find that open review’s impact on authors’ efforts is sensitive to the strength of several other influences. (shrink)

Paul Ramsey has argued that the rule of double effect is morally significant because of the existence of indeterminate choices between incommensurable values. I interpret his argument as the following disjunctive syllogism. There are two sorts of principles we can appeal to in dealing with indeterminate choices: the rule of double effect and a commensurate reason principle. The second does not work, so we are left with the first. I respond, first, that this argument commits the fallacy of bifurcation (...) and second, that for all Ramsey has shown, and surprisingly, a commensurate reason principle can deal with indeterminate choices. (shrink)

This paper presents the evaluation and the regulation of an initial teacher training programme which has been investigated from a scientifical point of view. The different researches realized have conduct the trainers to adapt the teacher training programme. These adaptations concern conceptual, pedagogical and methodological aspects. The assessment of the effects of these adaptations over a period of about ten years illustrate the approach that combines research and training and the richness of the double role of the researchers who (...) are also trainers. (shrink)

In 1837 the German-born astronomer F. G. W. Struve published his famous catalogue of double stars. For Struve this was the culmination of 12 years' detailed observation of a class of celestial objects lying exclusively beyond the solar system; for historians of astronomy it poses the problem of explaining why the study of double stars became a significant part of astronomical endeavour, as it did, during the 1820s and 1830s. For, although Struve's interest was extreme, it was shared to a (...) lesser extent by several eminent contemporaries, including John Herschel, Friedrich Bessel, Johann Encke, James South and Félix Savary. Their combined efforts represented an important transition in astronomy: for the first time one of the emphases of the subject moved beyond the solar system to the so-called fixed stars. The question of the emergence of interest in double stars is of historical significance, therefore, as it is related to the problem of the origins of ‘stellar astronomy’. This essay is thus intended to offer an explanation of astronomers' interest in double stars, and to tackle the related question of whether this transition constituted a major break in the history of astronomy. Furthermore it is proposed that answers to these problems may be found by considering the practice of astronomy dominant during the first half of the nineteenth century. Astronomers in this period were overwhelmingly concerned with a refined form of positional astronomy. The problems they chose to solve were by and large related to the difficulties of the accurate reduction of observational data, and the compilation of reliable tables and star charts, which were then used as a background against which the motions of solar system objects were plotted. By assessing individuals' studies of double stars within this context it can be seen firstly that such studies were no more or less than specific examples of a general case, and secondly that the stars themselves were not usually of intrinsic interest. In general it was the positions of the stars on the. (shrink)

What role do science and scientists play in the transition between food regimes? Scientific communities are integral to understanding political struggle during food regime transitions in part due to the broader scientization of politics since the late 1800s. While social movements contest the rules of the game in explicitly value-laden terms, scientific communities make claims to the truth based on boundary work, or efforts to mark some science and scientists as legitimate while marking others as illegitimate. In doing so, scientific (...) communities attempt to establish and maintain the privileged position of science in contests over policy. In this paper, we situate scientific boundary work within its world historical context in order to ask two key questions: (1) how does scientific boundary work vary across food regimes; and, in turn, (2) what role does scientific boundary work play in the political contestation that drives transitions between food regimes? We explore these questions through the case of one scientific community—the AOAC (Association of Official Analytical Communities)—involved in food safety regulation across the British, US, and corporate food regimes. We argue that scientific boundary work is shaped by historically specific patterns of social conflict within food regimes and, in particular, the double-movement dynamics that Polanyi (The great transformation: the political and economic origins of our times. Boston: Beacon, 1957[1944]) theorizes. Moreover, as scientific communities reconstruct their internal rules, norms, and procedures to claim their own legitimacy in relation to prevailing forms of social conflict, they also reshape who sets scientific agendas and thus the knowledge available for making new rules within periods of food regime transition. To elaborate this argument in theoretical terms, we build on recent efforts to integrate a neo-Polanyian perspective into food regime analysis and link this to research on scientific boundary work by scholars in science and technology studies. (shrink)

Cet article analyse la place occupée dans les parcours de vie par différents événements historiques de la période transitoire entre l’époque soviétique et postsoviétique. Il s’appuie sur deux terrains de recherche : un conduit en Russie auprès de familles d’au moins trois générations, l’autre – en Allemagne auprès de migrants arrivés en tant que Juifs de l’espace soviétique. L’article montre que dans les récits, les différentes dates officielles de l’époque ne sont pas réellement distinguées, mais traités davantage comme un seul (...) événement, ne se décomposant pas en éléments distincts. Nous proposons de distinguer trois types de discours biographiques en fonction de la place accordée à la période dans les parcours de vie. Le premier type de discours peut être qualifié d’anhistorique car il tend à ignorer les changements macrosociaux. La deuxième façon de mettre son parcours de vie en récit consiste à présenter la période transitionnelle comme une rupture, causant une bifurcation individuelle. Enfin, certains de nos interlocuteurs qualifient la transition d’une parenthèse, en rapprochant à travers leur vécu la période soviétique et postsoviétique. (shrink)