Implementar Programas de Qualidade e de Segurança do Doente: Que Ganhos Podemos Esperar?

A segurança e a qualidade num sistema de saúde têm uma expressão individual e sistémica: o doente submete-se a cuidados progressivamente mais tecnológicos, invasivos e fragmentados numa organização que pretende garantir que o ganho em complexidade não se traduza simultaneamente em maior risco e lesão. Qualidade e segurança são habitualmente difíceis de quantificar. Que definições usar? Quais as medidas adequadas para avaliar lesão, erro ou fiabilidade? São necessárias medidas objetivas e úteis que permitam a monitorização, pelas equipas de saúde, dos ganhos obtidos na implementação de planos de melhoria da prática clínica. Nas equipas de saúde é frequente a incompreensão dos conceitos de qualidade e segurança. Com base na experiência de 12 anos da implementação de um programa de Qualidade e Gestão de Risco num Centro Hospitalar de Lisboa, tentamos aqui responder a algumas das questões que são habitualmente levantadas sobre o tema

Small perturbations in a finger-tapping task reveal inherent nonlinearities of the underlying error correction mechanism

Time estimation is critical for survival and control of a variety of behaviors, both in humans and other animals. Time processing in the few hundred milliseconds range, known as millisecond timing, is involved in motor control, speech generation and recognition, and sensorimotor synchronization like playing music or finger tapping to an external beat. In finger tapping, a mechanistic explanation in terms of neuronal activations of how the brain achieves average synchronization against inherent noise and perturbations in the stimulus sequence is still missing despite considerable research. In this work we show that nonlinear effects are important for the recovery of synchronization following a perturbation (a step change in stimulus period), even for perturbation magnitudes smaller than 10% of the period, which is well below the amount of perturbation needed to display other nonlinear effects like saturation. We build a mathematical model for the error correction mechanism and test its predictions, and further propose a framework that allows us to unify the description of the three common types of perturbations and all perturbation magnitudes with a single set of parameter values. While previous works have proposed that multiple mechanisms/strategies are used for correcting different perturbation conditions (based on fitting the model?s parameters separately to different perturbation types and sizes), our results suggest that the synchronization behavior can be interpreted as the outcome of a single mechanism/strategy, and call for a revision of the idea of multiple strategies.Fil: Bavassi, Mariana Luz. Universidad Nacional de Quilmes. Departamento de Ciencia y Tecnologia; Argentina;Fil: Tagliazucchi, Enzo. Universidad Nacional de Quilmes. Departamento de Ciencia y Tecnologia; Argentina;Fil: Laje, Rodrigo. Universidad Nacional de Quilmes. Departamento de Ciencia y Tecnologia; Argentina; University Of California; Estados Unidos de América

Smooth operator: Avoidance of subharmonic bifurcations through mechanical mechanisms simplifies song motor control in adult zebra finches

Like human infants, songbirds acquire their song by imitation and eventually generate sounds that result from complicated neural networks and intrinsically nonlinear physical processes. Signatures of low-dimensional chaos such as subharmonic bifurcations have been reported in adult and developing zebra finch song. Here, we use methods from nonlinear dynamics to test whether adult male zebra finches (Taenopygia guttata) use the intrinsic nonlinear properties of their vocal organ, the syrinx, to insert subharmonic transitions in their song. In contrast to previous data on the basis of spectrographic evidence, we show that subharmonic transitions do not occur in adult song. Subharmonic transitions also do not arise in artificially induced sound in the intact syrinx, but are commonly generated in the excised syrinx. These findings suggest that subharmonic transitions are not used to increase song complexity, and that the brain controls song in a surprisingly smooth control regimen. Fast, smooth changes in acoustic elements can be produced by direct motor control in a stereotyped fashion, which is a more reliable indicator of male fitness than abrupt acoustic changes that do not require similarly precise control. Consistent with this view is the presence of high fidelity at every level of motor control, from telencephalic premotor areas to superfast syringeal muscles

Learning of Temporal Motor Patterns: An Analysis of Continuous Versus Reset Timing

Our ability to generate well-timed sequences of movements is critical to an array of behaviors, including the ability to play a musical instrument or a video game. Here we address two questions relating to timing with the goal of better understanding the neural mechanisms underlying temporal processing. First, how does accuracy and variance change over the course of learning of complex spatiotemporal patterns? Second, is the timing of sequential responses most consistent with starting and stopping an internal timer at each interval or with continuous timing? To address these questions we used a psychophysical task in which subjects learned to reproduce a sequence of finger taps in the correct order and at the correct times – much like playing a melody at the piano. This task allowed us to calculate the variance of the responses at different time points using data from the same trials. Our results show that while “standard” Weber’s law is clearly violated, variance does increase as a function of time squared, as expected according to the generalized form of Weber’s law – which separates the source of variance into time-dependent and time-independent components. Over the course of learning, both the time-independent variance and the coefficient of the time-dependent term decrease. Our analyses also suggest that timing of sequential events does not rely on the resetting of an internal timer at each event. We describe and interpret our results in the context of computer simulations that capture some of our psychophysical findings. Specifically, we show that continuous timing, as opposed to “reset” timing, is consistent with “population clock” models in which timing emerges from the internal dynamics of recurrent neural networks

Complexity without chaos: Plasticity within random recurrent networks generates robust timing and motor control

It is widely accepted that the complex dynamics characteristic of recurrent neural circuits contributes in a fundamental manner to brain function. Progress has been slow in understanding and exploiting the computational power of recurrent dynamics for two main reasons: nonlinear recurrent networks often exhibit chaotic behavior and most known learning rules do not work in robust fashion in recurrent networks. Here we address both these problems by demonstrating how random recurrent networks (RRN) that initially exhibit chaotic dynamics can be tuned through a supervised learning rule to generate locally stable neural patterns of activity that are both complex and robust to noise. The outcome is a novel neural network regime that exhibits both transiently stable and chaotic trajectories. We further show that the recurrent learning rule dramatically increases the ability of RRNs to generate complex spatiotemporal motor patterns, and accounts for recent experimental data showing a decrease in neural variability in response to stimulus onset

Taxonomía del token digital

La irrupción de la tecnología blockchain representa un cambio de paradigma en la construcción de confianza y de entender el funcionamiento de las sociedades modernas. Ello es así dado que permite la creación de activos digitales sin necesidad de contar con un intermediario ni una autoridad central que valide el proceso. El desafío que recae sobre el universo de actores interesados (dirigentes políticos, empresarios, emprendedores, etc.), será generar bases sólidas y uniformes que permitan inyectar previsibilidad y confianza en el sistema. De allí la necesidad de explorar este aspecto sumamente controvertido como es la taxonomía del Token Digital

Spatiotemporal perturbations in paced finger tapping suggest a common mechanism for the processing of time errors

Paced finger tapping is a sensorimotor synchronization task where a subject has to keep pace with a metronome while the time differences (asynchronies) between each stimulus and its response are recorded. A usual way to study the underlying error correction mechanism is to perform unexpected temporal perturbations to the stimuli sequence. An overlooked issue is that at the moment of a temporal perturbation two things change: the stimuli period (a parameter) and the asynchrony (a variable). In terms of experimental manipulation, it would be desirable to have separate, independent control of parameter and variable values. In this work we perform paced finger tapping experiments combining simple temporal perturbations (tempo step change) and spatial perturbations with temporal effect (raised or lowered point of contact). In this way we decouple the parameter-and-variable confounding, performing novel perturbations where either the parameter or the variable changes. Our results show nonlinear features like asymmetry and are compatible with a common error correction mechanism for all types of asynchronies. We suggest taking this confounding into account when analyzing perturbations of any kind in finger tapping tasks but also in other areas of sensorimotor synchronization, like music performance experiments and paced walking in gait coordination studies.Fil: Lopez, Sabrina Laura. Universidad Nacional de Quilmes. Departamento de Ciencia y Tecnología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Laje, Rodrigo. Universidad Nacional de Quilmes. Departamento de Ciencia y Tecnología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

A propósito de la libertad religiosa

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La voluntad del Padre en la soteriología de Santo Tomás

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