Dynamical complexity of discrete time regulatory networks

Genetic regulatory networks are usually modeled by systems of coupled differential equations and by finite state models, better known as logical networks, are also used. In this paper we consider a class of models of regulatory networks which present both discrete and continuous aspects. Our models consist of a network of units, whose states are quantified by a continuous real variable. The state of each unit in the network evolves according to a contractive transformation chosen from a finite collection of possible transformations, according to a rule which depends on the state of the neighboring units. As a first approximation to the complete description of the dynamics of this networks we focus on a global characteristic, the dynamical complexity, related to the proliferation of distinguishable temporal behaviors. In this work we give explicit conditions under which explicit relations between the topological structure of the regulatory network, and the growth rate of the dynamical complexity can be established. We illustrate our results by means of some biologically motivated examples.Comment: 28 pages, 4 figure

Integrated sizing and scheduling of wind/PV/diesel/battery isolated systems

In this paper we address the optimal sizing and scheduling of isolated hybrid systems using an optimization framework. The hybrid system features wind and photovoltaic conversion systems, batteries and diesel backup generators to supply electricity demand. A Mixed-Integer Linear Programming formulation is used to model system behavior over a time horizon of one year, considering hourly changes in both the availability of renewable resources and energy demand. The optimal solution is achieved with respect to the minimization of the levelized cost of energy (LCOE) over a lifetime of 20 years. Results for a case study show that the most economical solution features all four postulated subsystems

Environmental impact of how carcasses from turkeys production industry are eliminated: a case study

The Americas is the largest turkey region in the world producing over 60% of the world total. After US, Brazil is the second largest producer in the region with more than 500,000 tons per year and, after European Union, the third producer in the world. For several reasons turkey production is prone to lost high number of effective, particularly the young poults are vulnerable to respiratory disease, outbreaks, including salmonellosis, which they become listless and, eventually, died. The production plants eliminate the turkey carcasses by composting them however when the compost facility is full, or many turkey poults died, the elimination can be done by burying them. The main aim of this work is study the practical conditions used by the production plants to landfill turkey carcasses. To perform the study a qualitative methodology was used combining the documentation analysis, including the legal framework and the companys records, and field work to make observations and interview the owner. The company chosen for this case study operated in Carlos Barbosa municipality (RS) with 5 collaborators and 12 years of uninterrupted activity, and capacity for 8,580 turkeys. In average the company lose by dead or illness around 1,500 turkeys per month and use 3 composting facilities each one with 2x1.5x1 m to disposal carcasses. Nevertheless, the company landfill nearby of its facilities dead turkeys without any control of aquifer or soil waterproof capacity. In conclusion, burying turkey carcasses needs an environmental impact assessment put in place and the incineration is not an economical viable treatment for this activity.info:eu-repo/semantics/publishedVersio

A Methodology to Design FPGA-based PID Controllers

This paper presents a methodology to implement PID (Proportional, Integral, Derivative) controllers in FPGAs (Field-Programmable Gate Arrays) using fixed-point numerical representation. The Matlab/Simulink environment is used for modeling, simulation and evaluation the performance provided by different fixed-point representations using a given control process. A static bit-width analyzer is used to give a specialized fixed-point representation for each operand/operator in the controller system. After bit-width analysis, a VHDL represen-tation of the system is generated. Results show that the proposed methodology leads to shorten design cycles achieving important resource savings by employing specialized fixed-point repre-sentations

Programa de formação avançada sobre a avaliação do desempenho das estações de tratamento de águas residuais

A água é um bem precioso para o desenvolvimento sustentável e para o bem-estar e dignidade humana. A sua escassez afeta mais de 40% da população mundial e a água potável representa somente 0,002% do total deste recurso natural. Assegurar a disponibilidade e gestão sustentável da água e saneamento para todos é, atualmente, um dos grandes desafios sociatais. O correto tratamento dos efluentes líquidos, por estações de tratamento de águas residuais (ETAR), antes de serem libertados para os receptores ambientais superficiais é de primordial importância. A formação avançada de técnicos de meio ambiente que possam contribuir para um melhor gerenciamento das ETAR é, concomitantemente, muito relevante. Este trabalho tem como objetivo apresentar um programa de formação avançada, desenhado e desenvolvido em Portugal, para a capacitação de um técnico a trabalhar numa ETAR mais bem preparado. A metodologia deste estudo de caso foi de natureza mista, envolvendo componente experimental e observacional em termos de competências técnicas e em termos de formação a metodologia foi qualitativa. Descrevem-se as principais atividades e são discutidos os principais pontos críticos de todo o processo de formação. Como conclusão é apresentada a forma como o formando integrou os diferentes conhecimentos e vivenciou a sua formação.info:eu-repo/semantics/publishedVersio

Analysis of Circulating Haemocytes from Biomphalaria glabrata following Angiostrongylus vasorum Infection Using Flow Cytometry

Angiostrongylus vasorum is an emerging parasite of dogs and related to carnivores that have an indirect life cycle, with a wide range of terrestrial and aquatic gastropods as the obligatory intermediate host. Unfortunately, the relationship between A. vasorum and their snail hosts remains poorly understood. Circulating haemocytes are the main line of cellular defence involved in the destruction of helminths in snails. Aiming to further characterize the haemocyte subsets in Biomphalaria snails, we have performed a flow cytometric analysis of whole haemolymph cellular components using a multiparametric dual colour labelling procedure. Our findings demonstrated that B. glabrata infected with A. vasorum have two major circulating haemocyte subsets, referred to as small and large haemocytes. Differences in the cell proportion occurred over time. The development of better invertebrate infection control strategies would certainly result in the better control of human diseases caused by other species of the genus Angiostrongylus. Such knowledge will assist in the establishment of novel control strategies aimed at parasites that use molluscs as intermediate hosts and clarify new aspects of the parasite-host relationship regarding cell recognition and activation mechanisms, which are also found in the innate response of vertebrates

Reduction and approximation in gyrokinetics

The gyrokinetics formulation of plasmas in strong magnetic fields aims at the elimination of the angle associated with the Larmor rotation of charged particles around the magnetic field lines. In a perturbative treatment or as a time-averaging procedure, gyrokinetics is in general an approximation to the true dynamics. Here we discuss the conditions under which gyrokinetics is either an approximation or an exact operation in the framework of reduction of dynamical systems with symmetryComment: 15 pages late

Control of Hamiltonian chaos as a possible tool to control anomalous transport in fusion plasmas

It is shown that a relevant control of Hamiltonian chaos is possible through suitable small perturbations whose form can be explicitly computed. In particular, it is possible to control (reduce) the chaotic diffusion in the phase space of a Hamiltonian system with 1.5 degrees of freedom which models the diffusion of charged test particles in a turbulent electric field across the confining magnetic field in controlled thermonuclear fusion devices. Though still far from practical applications, this result suggests that some strategy to control turbulent transport in magnetized plasmas, in particular tokamaks, is conceivable. The robustness of the control is investigated in terms of a departure from the optimum magnitude, of a varying cut-off at large wave vectors, and of random errors on the phases of the modes. In all three cases, there is a significant region of maximum efficiency in the vicinity of the optimum control term.Comment: 17 pages, 21 figure