Unified models of the cosmological dark sector

We model the cosmological substratum by a viscous fluid that is supposed to provide a unified description of the dark sector and pressureless baryonic matter. In the homogeneous and isotropic background the \textit{total} energy density of this mixture behaves as a generalized Chaplygin gas. The perturbations of this energy density are intrinsically non-adiabatic and source relative entropy perturbations. The resulting baryonic matter power spectrum is shown to be compatible with the 2dFGRS and SDSS (DR7) data. A joint statistical analysis, using also Hubble-function and supernovae Ia data, shows that, different from other studies, there exists a maximum in the probability distribution for a negative present value $q_{0} \approx - 0.53$ of the deceleration parameter. Moreover, different from other approaches, the unified model presented here favors a matter content that is of the order of the baryonic matter abundance suggested by big-bang nucleosynthesis.Comment: 4 pages, 1 figure, submitted to the Proceedings of the Spanish Relativity Meeting - ERE 2010, Granada, September 6 - September 10, 201

Viscous dark fluid universe

We investigate the cosmological perturbation dynamics for a universe consisting of pressureless baryonic matter and a viscous fluid, the latter representing a unified model of the dark sector. In the homogeneous and isotropic background the \textit{total} energy density of this mixture behaves as a generalized Chaplygin gas. The perturbations of this energy density are intrinsically non-adiabatic and source relative entropy perturbations. The resulting baryonic matter power spectrum is shown to be compatible with the 2dFGRS and SDSS (DR7) data. A joint statistical analysis, using also Hubble-function and supernovae Ia data, shows that, different from other studies, there exists a maximum in the probability distribution for a negative present value $q_0 \approx - 0.53$ of the deceleration parameter. Moreover, while previous descriptions on the basis of generalized Chaplygin gas models were incompatible with the matter power spectrum data since they required a much too large amount of pressureless matter, the unified model presented here favors a matter content that is of the order of the baryonic matter abundance suggested by big-bang nucleosynthesis.Comment: 19 pages, 6 figure

A dynamic field approach to goal inference and error monitoring for human-robot interaction

In this paper we present results of our ongoing research on non-verbal human-robot interaction that is heavily inspired by recent experimental findings about the neuro-cognitive mechanisms supporting joint action in humans. The robot control architecture implements the joint coordination of actions and goals as a dynamic process that integrates contextual cues, shared task knowledge and the predicted outcome of the user’s motor behavior. The architecture is formalized by a coupled system of dynamic neural fields representing a distributed network of local but connected neural populations with specific functionalities. We validate the approach in a task in which a robot and a human user jointly construct a toy ’vehicle’. We show that the context-dependent mapping from action observation onto appropriate complementary actions allows the robot to cope with dynamically changing joint action situations. This includes a basic form of error monitoring and compensation.Fundação para a Ciência e a Tecnologia (FCT) - POCI/V.5/A0119/2005, CONC-REEQ/17/200

Pattern breaking: a complex systems approach to psychedelic medicine

Recent research has demonstrated the potential of psychedelic therapy for mental health care. However, the psychological experience underlying its therapeutic effects remains poorly understood. This paper proposes a framework that suggests psychedelics act as destabilizers, both psychologically and neurophysiologically. Drawing on the ‘entropic brain’ hypothesis and the ‘RElaxed Beliefs Under pSychedelics’ model, this paper focuses on the richness of psychological experience. Through a complex systems theory perspective, we suggest that psychedelics destabilize fixed points or attractors, breaking reinforced patterns of thinking and behaving. Our approach explains how psychedelic-induced increases in brain entropy destabilize neurophysiological set points and lead to new conceptualizations of psychedelic psychotherapy. These insights have important implications for risk mitigation and treatment optimization in psychedelic medicine, both during the peak psychedelic experience and during the subacute period of potential recovery.Peer Reviewe

Propriedades físicas e infiltração de água de um Latossolo Vermelho Amarelo (Oxisol) do noroeste do estado de São Paulo, Brasil, sob três condições de uso e manejo

This study presents the results obtained in a field experiment carried out at Glicério, Northwest of São Paulo state, Brazil, whose objective was to analyze changes of selected soil physical properties and water infiltration rates on a Yellow-Red Latosol, under three different management conditions. The experimental design was arranged as completely randomized split-block with twelve treatments, which corresponded to four depths (0-0.05 m; 0.05-0.10 m; 0.10-0.20 m and 0.20-0.40 m) and three conditions of soil use and management with four replications. The soil surface conditions were: conventional tillage (one disking with moulboard plus two levelling passes with harrow), nine months before starting filed experiences; recent conventional tillage (also one disking with moulboard plus two levelling passes with harrow) and native forest. The conventional tillage areas were cropped for about fifteen years with annual cultures. The considered soil general physical properties were: macroporosity, microporosity, total porosity, bulk density, soil moisture and penetration resistance and, in addition; soil water infiltration rates were also recorded. According to our results, differences on general soil physical properties and infiltration rates appeared when both tilled sub-treatments and native forest were compared. Both, plots recently prepared by conventional tillage and those prepared by tillage but left nine months in rest, presented a statistically significant decrease of constant (final) water infiltration rates of 92.72% and 91.91% when compared with native forest plots

A dynamic field approach to goal inference, error detection and anticipatory action selection in human-robot collaboration

In this chapter we present results of our ongoing research on efficient and fluent human-robot collaboration that is heavily inspired by recent experimental findings about the neurocognitive mechanisms supporting joint action in humans. The robot control architecture implements the joint coordination of actions and goals as a dynamic process that integrates contextual cues, shared task knowledge and the predicted outcome of the user's motor behavior. The architecture is formalized as a coupled system of dynamic neural fields representing a distributed network of local but connected neural populations with specific functionalities. We validate the approach in a task in which a robot and a human user jointly construct a toy 'vehicle'. We show that the context-dependent mapping from action observation onto appropriate complementary actions allows the robot to cope with dynamically changing joint action situations. More specifically, the results illustrate crucial cognitive capacities for efficient and successful human-robot collaboration such as goal inference, error detection and anticipatory action selection.FCT grants POCI/V.5/A0119/2005 and CONC-REEQ/17/2001 / fp6-IST2 EU-IP Project JAST (proj. nr. 003747

Equipo mecánico para la cosecha de tunas

México es el mayor productor y consumidor de tunas en el mundo, donde alrededor 20,000 pequeños productores cultivan nopal tunero en una extensión de aproximadamente 74,500 ha

Multiple Resistance to Glyphosate and 2,4-D in Carduus acanthoides L. from Argentina and Alternative Control Solutions

Carduus acanthoides L. is an invasive species native to Europe and distributed in other parts of the world, including North and South America. In Cordoba, Argentina, control failures of this species have been reported in Roundup Ready (RR) soybean crops where glyphosate and 2,4-D have frequently been applied, although there are no confirmed reports worldwide of resistance to glyphosate and 2,4-D in this species. Dose–response tests showed multiple-resistance to both active principles. The resistant population (R) had LD50 values of 1854.27 and 1577.18 g ae ha−1 (grams of acid equivalent per hectare), while the susceptible (S) population had LD50 values of 195.56 and 111.78 g ae ha−1 for glyphosate and 2,4-D, respectively. Low accumulations of shikimic acid (glyphosate) and ethylene (2,4-D) at different doses in the R population compared to the S population support the results observed in the dose–response curves. No significant differences in leaf retention were observed for glyphosate and 2,4-D in the R and S populations. However, the use of adjuvants increased the retention capacity of herbicides in both populations. Ten alternative herbicides with seven different action mechanisms (MOAs) were evaluated and the most effective active principles were dicamba, bromoxynil, atrazine, tembotrione, flazasulfuron, glufosinate, and paraquat. These findings are the first evidence of glyphosate and 2,4 D resistance in C. acanthoides

Papéis e competências dos responsáveis pelos recursos humanos nos cuidados de saúde primários

Mestrado em Gestão de Recursos HumanosUma das novidades da Reforma dos Cuidados de Saúde Primários foi a criação de Agrupamentos de Centros de Saúde (ACES), com unidades funcionais, que agrupam um ou mais Centros de Saúde com a missão de garantir Cuidados de Saúde Primários à população de determinada área geográfica. Com base nos papéis e competências que a literatura reconhece fundamentais num gestor de Recursos Humanos procura-se para o ACES em estudo, e como objetivos, especificar e descrever: o modelo organizacional que enquadra o modelo de gestão de recursos humanos (GRH); o modelo de produção; os papéis e competências de GRH que os responsáveis pelos RH desenvolvem; o modelo de GRH, as suas forças e fraquezas e o seu posicionamento estratégico e/ou operacional. Optou-se por um estudo de caso único inclusivo (o modelo de GRH) com uma única unidade de análise embutida (um dos ACES da Região de Saúde de Lisboa e Vale do Tejo). Foi realizado um grupo focal conduzido por uma facilitadora e uma co-facilitadora que contou com a participação de cinco dirigentes do ACES. A discussão, gravada depois de obtida a autorização verbal de todos os presentes, foi orientada por um guião. A gravação foi transcrita e o texto foi sujeito a análise de conteúdo segundo uma abordagem qualitativa categorial, garantindo-se o anonimato dos intervenientes. Estes foram informados dos objetivos da investigação e deram verbalmente autorização para gravar a entrevista. Os resultados apontam para um modelo organizacional em que o principal mecanismo de coordenação é o ajustamento mútuo, a tomada de decisão está centrada nos gestores intermédios e os postos de trabalho estão tendencialmente organizados numa esoecialização horizontal, em ambiente complexo mas estável. A organização do trabalho é feita através de uma divisão vertical do trabalho flexível, trabalho em grupo, rotação de tarefas e polivalência limitada; predominam os trabalhadores qualificados com uma baixa proporção do trabalhador indirecto; o sistema de informação/comunicação é multidireccional. Os RH participam e relacionam-se através da participação direta e de relações de trabalho de cooperação. No ACES não existe um gestor de RH. A função gestora de RH é partilhada entre a Administração Central do Sistema de Saúde (ACSS), a ARS e os vários dirigentes no ACES. No modelo de GRH na ACES, a principal função pessoal reflecte-se no alargamento e enriquecimento de tarefas e no ajustamento às previsíveis necessidades; o âmbito da ação da GRH conge-se à aplicação da regulamentação jurídica e de normas internas, garantindo as operações administrativas necessárias ao funcionamento da organização. O posdicionamento da GRH no ACES é essencialmente operacional e centrado nos processos. Estes resultados reforçam a perceção de que a gestão e o desenvolvimento dos recursos humanos, aqui, como noutras reformas, são uma área negligenciada. Os responsáveis pelos RH nos ACES não estão claramente identificados e os papéis, competências e técnicas de GRH ou não são conhecidos ou, se conhecidos, estão dispersos por diversos atores, não só nos ACES mas até em organismos da ACSS - uma conclusão surpreendente se considerarmos que a reforma nasceu muito centrada em questões de GRH, de um conjunto de experiências que, ao longo de duas décadas, foi procurando novas formas de organizar e remunerar o trabalho dos médicos de família.N/