Quorum sensing-induced phenotypic switching as a regulatory nutritional stress response in a competitive two-species biofilm: An individual-based cellular automata model

Competition for nutrients in a polymicrobial biofilm may lead to susceptible species being subjected to nutritionalstress. The influence of bacterial growth rates and interspecies interactions on their susceptibility and response tonutritional stress is not well understood. Pseudomonas aeruginosa and Staphylococcus aureus are two prevalentcausative pathogens that coexist in biofilm-associated infections. Despite being the slower-growing species, P.aeruginosa dominates in a two-species biofilm by inducing phenotypic switching of S. aureusto a metabolicallychallenged small colony variant (SCV) via the release of 2-heptyl-4-hydroxyquinoline N-oxide (HQNO). Wehypothesize that P. aeruginosa experiences nutritional stress in competition with S. aureus, and that the release ofHQNO is an adaptive response to nutritional stress. We present an individual-based two-species biofilm model inwhich interactions between entities induce emergent properties. As the biofilm matured, the difference in growthrates of the two species caused a non-uniform distribution of nutrients leading to nutritional stress for P. aeruginosa and a concurrent increase in the proportion of S. aureus subpopulation. The latter resulted in increasedrelease of autoinducer, and subsequently the upregulation of P. aeruginosa cells via quorum sensing. UpregulatedP. aeruginosa cells released HQNO at enhanced rates, thereby inducing phenotypic switching of S. aureus toSCVs which consume nutrient at a reduced rate. This shifted the nutrient distribution back in favor of P.aeruginosa, thereby relieving nutritional stress. Increase in nutritional stress potentiated the transformation of S.aureus into SCVs. HQNO production decreased once nutritional stress was relieved, indicating that phenotypicswitching acts as a regulatory stress-adaptive response.

A paixão pelo autômato: a condição maquínicas / The passion towards the automaton: the machinic condition / La pasión por el autómata: la condición maquínica

Neste escrito, visamos a explorar os desdobramentos da figura do autômato no cinema e o fascínio que ele desperta. Sob a forma de ensaio, traçamos a genealogia do autômato na cultura, da Grécia antiga a Hollywood, e examinamos sua aparição ao longo da história do cinema, assinalando alguns dos filmes em que suas diversas facetas encontram-se representadas. Do precipitado formado pela incidência fílmica do autômato, sublinhamos os traços conferidos na Contemporaneidade a essa composição, acentuando a filiação ao homem, a natureza robótica e a obediência ao desígnio. Dialogando com a psicanálise, examinamos o conceito de duplo e de compulsão à repetição, assinalando a figura do autômato como duplo do sujeito da Contemporaneidade, encarnando a fantasia de denegação do mal-estar produzida como legado do tecnicismo, do cientificismo e do capitalismo tardio. Concluímos que os autômatos do cinema desvelam uma verdade sob o caráter de ficção: os sujeitos da Contemporaneidade fantasiam os ideais da condição maquínica.

In this article we intend to explore the displays of automaton figure on movies and the passion it arouses. Written in the form of an essay, this paper traces the automaton genealogy inside our culture, from Ancient Greece to Hollywood, and his presence in cinema history, pointing out some of the movies where its multiple appearances are represented. We have highlighted from the automaton occurrence on movies, the traces checked at contemporary times in this composition, underlining the filiation to mankind, the robotic nature and the submission to fate. Keeping a dialogue with psychoanalytical theory, the authors explore the concepts of the double and the repetition compulsion, marking the automaton figure as a double of the contemporary subject, embodying the fantasy of denying the uneasiness produced as a legacy of technicality, scientism and late capitalism. Our conclusion is that the movies automata unveil the truth hiding under the status of fiction: contemporary subjects fantasize the ideals of machinic condition

En este escrito nos proponemos estudiar, con la ayuda del psicoanálisis, los desdoblamientos de la figura del autómata en el cine y la fascinación que provoca. En forma de ensayo, rastreamos la genealogía del autómata en la cultura, desde la antigua Grecia a Hollywood, y su aparición en la historia del cine, enumerando algunas de las películas en las que sus diversas facetas son representadas. De la observación de la incidencia del autómata en películas, se destacan los rasgos que hoy en día son conferidos para esta composición, subrayando la filiación al hombre, la naturaleza robótica y la obediencia a su destino. Dialogando con el psicoanálisis, examinamos los conceptos de doble y de compulsión de repetición, teniendo en cuenta el autómata como el doble del sujeto de la actualidad, que incorpora la fantasía de negación del malestar producida como un legado del tecnicismo, del cientificismo y del capitalismo tardío. Llegamos a la conclusión de que los autómatas del cine dieron a conocer una verdad bajo el status de ficción: los sujetos contemporáneos fantasean con los ideales de la condición maquínica.

Simulating the behavior of patients who leave a public hospital emergency department without being seen by a physician: a cellular automaton and agent-based framework

The objective of this study was to develop an agent based modeling (ABM) framework to simulate the behavior of patients who leave a public hospital emergency department (ED) without being seen (LWBS). In doing so, the study complements computer modeling and cellular automata (CA) techniques to simulate the behavior of patients in an ED. After verifying and validating the model by comparing it with data from a real case study, the significance of four preventive policies including increasing number of triage nurses, fast-track treatment, increasing the waiting room capacity and reducing treatment time were investigated by utilizing ordinary least squares regression. After applying the preventing policies in ED, an average of 42.14% reduction in the number of patients who leave without being seen and 6.05% reduction in the average length of stay (LOS) of patients was reported. This study is the first to apply CA in an ED simulation. Comparing the average LOS before and after applying CA with actual times from emergency department information system showed an 11% improvement. The simulation results indicated that the most effective approach to reduce the rate of LWBS is applying fast-track treatment. The ABM approach represents a flexible tool that can be constructed to reflect any given environment. It is also a support system for decision-makers to assess the relative impact of control strategies.

Deus está morto. Viva o autômato! / God is dead. Long live the automaton! / Dios ha muerto. ¡Viva el autómata!

O artigo propõe-se a pensar algo do pathos da Modernidade ­ a paixão pelo autômato ­, à luz do conceito nietzschiano Morte de Deus. Nesse sentido, toma como matéria de análise dois clássicos do cinema de ficção científica: 2001: uma odisseia no espaço, de Stanley Kubrick, e Blade runner, de Ridley Scott. Se a paixão pelo autômato consiste em uma forma do sujeito moderno denegar a finitude, nos filmes em debate tal condição é elaborada de um modo muito singular. 2001 e Blade runner oferecem ao espectador a possibilidade de resistir à assunção dessa inclinação da subjetividade moderna. Em 2001, o autômato é demasiado humano e uma narrativa trágica promove outro modo de enfrentar a finitude. Em Blade runner, o autômato é o portador das angústias fundamentais do sujeito moderno ­ origem e finitude ­ e a identificação a ele permite ao espectador ir além do homem. (AU)

The article proposes to address an issue from Modernity pathos ­ the passion for the automaton ­, in the light of Nietzschian Death of God concept. In this sense, it analyses two science fiction classic movies: 2001: a space odyssey, by Stanley Kubrick, and Blade runner, by Ridley Scott. If passion for the automaton consists in a form of the modern subject to deny finitude, in the films here discussed such condition is elaborated in a very peculiar way. 2001 and Blade runner offer the spectator the possibility of resisting the assumption of such tendency of modern subjectivity. In 2001, the automaton is too human and a tragic narrative promotes another way of tackling finitude. In Blade runner, the automaton is the bearer of fundamental anguishes of the modern subject ­ origin and finitude ­ and by identifying with him the viewer is allowed to go beyond man. (AU)

El artículo se propone a pensar algo respecto al pathos de la Modernidad ­ la pasión por lo autómata ­ bajo el concepto de Nietzsche Muerte de Dios. En este sentido, el análisis toma como materia dos clásicos del cine de ciencia ficción: 2001: una odisea del espacio, de Stanley Kubrick, y Blade runner, de Ridley Scott. Si la pasión por lo autómata consiste en una forma del sujeto moderno denegar la finitud, en esas películas tal condición es elaborada de una manera muy singular. 2001 y Blade runner ofrecen al espectador la posibilidad de resistir a la asunción de tal inclinación de la subjetividad moderna. En 2001, el autómata es demasiado humano y una narrativa trágica promueve otro modo de enfrentar la finitud. En Blade runner, el autómata es el portador de las angustias fundamentales del sujeto moderno ­ de origen y finitud ­ y la identificación a él le permite al espectador ir más allá del hombre. (AU)

Simulation of the epidemic of influenza A(H1N1)in a university using cel-lular automata model / 中国感染控制杂志

Objective To explore the application value of cellular automata(CA)in simulating the epidemic spread of out-break of influenza A(H1N1).Methods The publications regarding influenza A(H1N1)from January 2009 to March 2015 were collected from the China National Knowledge Infrastructure(CNKI),epidemiological data of H1N1 were retrieved ac-cording to inclusion criteria,the Matlab 7.0 software was adopted to construct CA model for simulating and analyzing the epidemic of H1N1 occurred in a university in Chongqing between October 12 and November 20,2009.Results There were a total of 17 820 students in this university,the epidemic of influenza lasted 40 days in 2009;When the parameter,the ef-fective infection rate was 0.04,the model of CA fit well,and gave estimate for basic reproduction number (R0 )1.202. Conclusion CA has certain reliability in simulating epidemics of airborne infectious diseases,it can provide reference for the prevention and control of disease.

Aging is not senescence: a short computer demonstration and implications for medical practice

INTRODUCTION: The discussion regarding the evolution of aging is almost as old as Darwinian Evolution Theory, but to date, it has remained one of biology's unresolved problems. One issue is how to reconcile natural selection, which is understood as a process that purges deleterious characteristics, with senescence, which seems to offer no advantages to the individual. METHOD: A computer simulation that illustrates an evolutionary mechanism for the development of senescence in populations is presented. DISCUSSION: In this article, we debate that two popular explanations for the existence of senescence, namely, (1) the removal of elders for the benefit of the species and (2) the progressive deterioration of the organic machine due to continuous use, are not correct. While human populations continue to age, it is important that the physician understands that senescence, here defined as the progressive impairment of an organism, does not necessarily accompany aging, which we here define as the mere passage of time. As such, we argue that certain processes that were originally assumed to be part of aging should have their status changed because they are actually diseases. Physicians often encounter situations that depend on a better understanding of what limitations senescence imposes on most living species. The concepts of aging (the unavoidable passage of time), senescence (progressive physiologic impairment), and senility (the pathological development of diseases), are discussed.

Dynamical Complexity in Cognitive Neural Networks

In the last twenty years an important effort in brain sciences, especially in cognitive science, has been the development of mathematical tool that can deal with the complexity of extensive recordings corresponding to the neuronal activity obtained from hundreds of neurons. We discuss here along with some historical issues, advantages and limitations of Artificial Neural Networks (ANN) that can help to understand how simple brain circuits work and whether ANN can be helpful to understand brain neural complexity.