Single-file dynamics with different diffusion constants

We investigate the single-file dynamics of a tagged particle in a system consisting of N hardcore interacting particles (the particles cannot pass each other) which are diffusing in a one-dimensional system where the particles have different diffusion constants. For the two particle case an exact result for the conditional probability density function (PDF) is obtained for arbitrary initial particle positions and all times. The two-particle PDF is used to obtain the tagged particle PDF. For the general N-particle case (N large) we perform stochastic simulations using our new computationally efficient stochastic simulation technique based on the Gillespie algorithm. We find that the mean square displacement for a tagged particle scales as the square root of time (as for identical particles) for long times, with a prefactor which depends on the diffusion constants for the particles; these results are in excellent agreement with very recent analytic predictions in the mathematics literature.Comment: 9 pages, 5 figures. Journal of Chemical Physics (in press

Cyclical population dynamics of automatic versus controlled processing : an evolutionary pendulum

Psychologists, neuroscientists, and economists often conceptualize decisions as arising from processes that lie along a continuum from automatic (i.e., “hardwired” or over-learned, but relatively inflexible) to controlled (less efficient and effortful, but more flexible). Control is central to human cognition, and plays a key role in our ability to modify the world to suit our needs. Given its advantages, reliance on controlled processing may seem predestined to increase within the population over time. Here, we examine whether this is so by introducing an evolutionary game theoretic model of agents that vary in their use of automatic versus controlled processes, and in which cognitive processing modifies the environment in which the agents interact. We find that, under a wide range of parameters and model assumptions, cycles emerge in which the prevalence of each type of processing in the population oscillates between two extremes. Rather than inexorably increasing, the emergence of control often creates conditions that lead to its own demise by allowing automaticity to also flourish, thereby undermining the progress made by the initial emergence of controlled processing. We speculate that this observation may have relevance for understanding similar cycles across human history, and may lend insight into some of the circumstances and challenges currently faced by our species

Shafranov's virial theorem and magnetic plasma confinement

Shafranov's virial theorem implies that nontrivial magnetohydrodynamical equilibrium configurations must be supported by externally supplied currents. Here we extend the virial theorem to field theory, where it relates to Derrick's scaling argument on soliton stability. We then employ virial arguments to investigate a realistic field theory model of a two-component plasma, and conclude that stable localized solitons can exist in the bulk of a finite density plasma. These solitons entail a nontrivial electric field which implies that purely magnetohydrodynamical arguments are insufficient for describing stable, nontrivial structures within the bulk of a plasma.Comment: 9 pages no figure

The evolution and devolution of cognitive control : the costs of deliberation in a competitive world

Dual-system theories of human cognition, under which fast automatic processes can complement or compete with slower deliberative processes, have not typically been incorporated into larger scale population models used in evolutionary biology, macroeconomics, or sociology. However, doing so may reveal important phenomena at the population level. Here, we introduce a novel model of the evolution of dual-system agents using a resource-consumption paradigm. By simulating agents with the capacity for both automatic and controlled processing, we illustrate how controlled processing may not always be selected over rigid, but rapid, automatic processing. Furthermore, even when controlled processing is advantageous, frequency-dependent effects may exist whereby the spread of control within the population undermines this advantage. As a result, the level of controlled processing in the population can oscillate persistently, or even go extinct in the long run. Our model illustrates how dual-system psychology can be incorporated into population-level evolutionary models, and how such a framework can be used to examine the dynamics of interaction between automatic and controlled processing that transpire over an evolutionary time scale

Realidade aumentada: tecnologia para o mercado imobiliário em um mundo virtual e real

A tecnologia de Realidade Aumentada permite a ocorrência que impactou no relacionamento das pessoas, por meio de novas formas de realizar a visualização, a comunicação e interação com pessoas e informações. A arte das aplicações de RA a diversos contextos (medicina, montagem e manutenção de maquinaria complexa, registro e visualização de zonas), com especial destaque para a questão da realidade aumentada aplicada ao ramo imobiliário e suas vertentes. A realidade aumentada consiste em adicionar informações digitais no ambiente real. A imagem virtual se sobrepõe com elementos 3D animados, desta forma, as páginas do catálogo podem subitamente ganhar vida com elementos que saem das suas páginas. A elaboração da Realidade Aumentada para Negócios Imobiliários utilizou-se do aplicativo SACRA. As aplicações de Realidade Aumentada utilizam um marcador para posicionar e orientar os elementos virtuais no mundo real, tornando-se um meio de interação do usuário com a aplicação. As distorções são evitadas com os parâmetros de câmera. Após a criação do arquivo (casa.dat), o código do arquivo vrml data (patern 2) sofre alterações. A linha do código “Data/casa” indica ao marcador casa.dat do diretório e a captura imediata de webcam para ilustrar a imagem 3D. As aplicações de Realidade Aumentada utilizam um marcador para posicionar e orientar os elementos virtuais no mundo real, e se configura em um meio de interação do usuário com a aplicação. Esses marcadores reconhecidos pelo ARToolKit, consistem em figuras geométricas quadradas, que no seu interior contém símbolos para sua melhor identificação. Após, o marcador é colocado na frente da webcam para cadastrá-lo no aplicativo. Em tempos de difusão da ideia de sustentabilidade ambiental, deixar de utilizar panfletos, publicar em jornais, fabricar maquetes é uma possibilidade que a RA traz para consolidar tal ideia. Basta observar as revistas e jornais de grande circulação que têm estimulado a utilização da RA como complemento da publicidade clássica

Partially Dual variables in SU(2) Yang-Mills Theory

We propose a reformulation of SU(2) Yang-Mills theory in terms of new variables. These variables are appropriate for describing the theory in its infrared limit, and indicate that it admits knotlike configurations as stable solitons. As a consequence we arrive at a dual picture of the Yang-Mills theory where the short distance limit describes asymptotically free, massless point gluons and the large distance limit describes extended, massive knotlike solitons.Comment: 4 pages, revtex twocolum

The hyperornithinemia-hyperammonemia-homocitrullinuria syndrome

Hyperornithinemia-hyperammonemia-homocitrullinuria (HHH) syndrome is a rare autosomal recessive disorder of the urea cycle. HHH has a panethnic distribution, with a major prevalence in Canada, Italy and Japan. Acute clinical signs include intermittent episodes of vomiting, confusion or coma and hepatitis-like attacks. Alternatively, patients show a chronic course with aversion for protein rich foods, developmental delay/intellectual disability, myoclonic seizures, ataxia and pyramidal dysfunction. HHH syndrome is caused by impaired ornithine transport across the inner mitochondrial membrane due to mutations in SLC25A15 gene, which encodes for the mitochondrial ornithine carrier ORC1. The diagnosis relies on clinical signs and the peculiar metabolic triad of hyperammonemia, hyperornithinemia, and urinary excretion of homocitrulline. HHH syndrome enters in the differential diagnosis with other inherited or acquired conditions presenting with hyperammonemia

Highly efficient organic light-emitting diodes and light-emitting electrochemical cells employing multiresonant thermally activated delayed fluorescent emitters with bulky donor or acceptor peripheral groups

Jingxiang Wang thanks the China Scholarship Council (202006250026). We thank the Engineering and Physical Sciences Research Council (EP/R035164/1, EP/W015137/1, and EP/W007517/1) for support. Ludvig Edman and Shi Tang acknowledge financial support from the Swedish Research Council (2019-02345 and 2021–04778), the Swedish Energy Agency (50779-1 and P2021-00032), the Wallenberg Initiative Materials Science for Sustainability (WISE) funded by the Knut and Alice Wallenberg Foundation (WISE-AP01-D02), and the European Research Council for an ERC Advanced Grant (Project 101096650).Multiresonant thermally activated delayed fluorescence (MR-TADF) emitters have been the focus of extensive design efforts as they are recognized to show bright, narrowband emission, which makes them very appealing for display applications. However, the planar geometry and relatively large singlet?triplet energy gap lead to, respectively, severe aggregation-caused quenching (ACQ) and slow reverse intersystem crossing (RISC). Here, a design strategy is proposed to address both issues. Two MR-TADF emitters triphenylphosphine oxide (TPPO)-tBu-DiKTa and triphenylamine (TPA)-tBu-DiKTa have been synthesized. Twisted ortho-substituted groups help increase the intermolecular distance and largely suppress the ACQ. In addition, the contributions from intermolecular charge transfer states in the case of TPA-tBu-DiKTa help to accelerate RISC. The organic light-emitting diodes (OLEDs) with TPPO-tBu-DiKTa and TPA-tBu-DiKTa exhibit high maximum external quantum efficiencies (EQEmax) of 24.4% and 31.0%, respectively. Notably, the device with 25 wt% TPA-tBu-DiKTa showed both high EQEmax of 28.0% and reduced efficiency roll-off (19.9% EQE at 1000 cd m?2) compared to the device with 5 wt% emitter (31.0% EQEmax and 11.0% EQE at 1000 cd m?2). The new emitters were also introduced into single-layer light-emitting electrochemical cells (LECs), equipped with air-stable electrodes. The LEC containing TPA-tBu-DiKTa dispersed at 0.5 wt% in a matrix comprising a mobility-balanced blend-host and an ionic liquid electrolyte delivered blue luminance with an EQEmax of 2.6% at 425 cd m?2. The high efficiencies of the OLEDs and LECs with TPA-tBu-DiKTa illustrate the potential for improving device performance when the DiKTa core is decorated with twisted bulky donors.Peer reviewe