970 research outputs found

    Harnessing low-level tuning in modern architectures for high-performance network monitoring in physical and virtual platforms

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    Tesis doctoral inédita leída en la Universidad Autónoma de Madrid, Escuela Politécnica Superior, Departamento de Tecnología Electrónica y de las Comunicaciones. Fecha de lectura: 02-07-201

    Red de procesadores evolutivos para solucionar el problema de los tres colores : implementación en hardware

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    En este trabajo se diseña una Red de Procesadores Evolutivos (NEP) para solucionar el Problema de los Tres Colores. Para obtener el resultado, se utilizó como recurso de Hardware un FPGA. El objetivo principal de este trabajo, es demostrar la factibilidad de la implementación física de algoritmos paralelos para solucionar problemas NP ? Completos. Con esta implementación se logra que la ejecución de la solución al problema se haga de forma fiable, rápida y eficaz. El proyecto fue desarrollado usando la herramienta ISE 12.1 de Xilinx, utilizando como lenguaje de descripción de hardware al VHDL. Para la simulación se utilizó la herramienta ISim 12.1, también de Xilinx. Los resultados fueron probados utilizando la plataforma Atlys Board de la compañía Digilent la cual contiene un FPGA Spartan-6 LX45, también de Xilinx. Se muestran imágenes de la herramienta empleada, del Kit de Pruebas, así como de la simulación realizada y una tabla con los datos que demuestran que la implementación de este algoritmo complejo utilizó muy pocos recursos del FPGA empleado. ABSTRACT In this paper, a Network of Evolutionary Processors (NEP) is implemented, to solve the problem of the three colors. To achieve implementation, it was used as an FPGA hardware resource. The main objective of this work is to demonstrate the feasibility of the physical implementation of parallel algorithms to solve problems NP - complete. With this implementation is achieved that the implementation of the solution to be made reliably, quickly and efficiently. The project was developed using the Xilinx ISE 12.1 tool, using hardware description language to VHDL. For the simulation tool was used ISim 12.1, also from Xilinx. The results were tested using the platform Atlys Board Company which contains a Digilent Spartan-6 LX45 FPGA, Xilinx also. Images of the tool used, the Test Kit and simulation performed and a table of data showing that the implementation of this complex algorithm used very few FPGA resources used are shown

    Physical Forces Shape Group Identity of Swimming Pseudomonas putida Cells

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    The often striking macroscopic patterns developed by motile bacterial populations on agar plates are a consequence of the environmental conditions where the cells grow and spread. Parameters such as medium stiffness and nutrient concentration have been reported to alter cell swimming behavior, while mutual interactions among populations shape collective patterns. One commonly observed occurrence is the mutual inhibition of clonal bacteria when moving toward each other, which results in a distinct halt at a finite distance on the agar matrix before having direct contact. The dynamics behind this phenomenon (i.e., intolerance to mix in time and space with otherwise identical others) has been traditionally explained in terms of cell-to-cell competition/cooperation regarding nutrient availability. In this work, the same scenario has been revisited from an alternative perspective: the effect of the physical mechanics that frame the process, in particular the consequences of collisions between moving bacteria and the semi-solid matrix of the swimming medium. To this end, we set up a simple experimental system in which the swimming patterns of Pseudomonas putida were tested with different geometries and agar concentrations. A computational analysis framework that highlights cell-to-medium interactions was developed to fit experimental observations. Simulated outputs suggested that the medium is compressed in the direction of the bacterial front motion. This phenomenon generates what was termed a compression wave that goes through the medium preceding the swimming population and that determines the visible high-level pattern. Taken together, the data suggested that the mechanical effects of the bacteria moving through the medium created a factual barrier that impedes to merge with neighboring cells swimming from a different site. The resulting divide between otherwise clonal bacteria is thus brought about by physical forces—not genetic or metabolic programs.This work was supported by the EVOPROG (FP7-ICT-610730), ARISYS (ERC-2012-ADG-322797), and EmPowerPutida (EU-H2020-BIOTEC-2014-2015-635536) Contracts of the European Union, and the CAMBIOS (RTC-2014-1777-3) and CONTIBUGS (PCIN-2013-040) Projects of the Spanish Ministry of Economy and Competitiveness.Peer Reviewe

    MEDUSA©: A novel Python-based software ecosystem to accelerate brain-computer interface and cognitive neuroscience research

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    Producción CientíficaBackground and objective. Neurotechnologies have great potential to transform our society in ways that are yet to be uncovered. The rate of development in this field has increased significantly in recent years, but there are still barriers that need to be overcome before bringing neurotechnologies to the general public. One of these barriers is the difficulty of performing experiments that require complex software, such as brain-computer interfaces (BCI) or cognitive neuroscience experiments. Current platforms have limitations in terms of functionality and flexibility to meet the needs of researchers, who often need to implement new experimentation settings. This work was aimed to propose a novel software ecosystem, called MEDUSA©, to overcome these limitations. Methods. We followed strict development practices to optimize MEDUSA© for research in BCI and cognitive neuroscience, making special emphasis in the modularity, flexibility and scalability of our solution. Moreover, it was implemented in Python, an open-source programming language that reduces the development cost by taking advantage from its high-level syntax and large number of community packages. Results. MEDUSA© provides a complete suite of signal processing functions, including several deep learning architectures or connectivity analysis, and ready-to-use BCI and neuroscience experiments, making it one of the most complete solutions nowadays. We also put special effort in providing tools to facilitate the development of custom experiments, which can be easily shared with the community through an app market available in our website to promote reproducibility. Conclusions. MEDUSA© is a novel software ecosystem for modern BCI and neurotechnology experimentation that provides state-of-the-art tools and encourages the participation of the community to make a difference for the progress of these fields. Visit the official website at https://www.medusabci.com/ to know more about this project.Ministerio de Ciencia e Innovación/Agencia Estatal de Investigación/10.13039/501100011033/' y el Fondo Europeo de Desarrollo Regional (FEDER) grants (PID2020-115468RB-I00 and RTC2019-007350-1

    The distribution of Cuban Brown Anoles, Anolis sagrei (Squamata: Dactyloidae), in Mexico, with new records and comments on ecological interactions

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    The Cuban Brown Anole (Anolis sagrei) is native to the Bahamas, the Cuba Archipelago, and Little Cayman, but is now among the world’s most widely distributed invasive lizards. In Mexico, the species has been reported from the states of Campeche, Chiapas, Jalisco, Quintana Roo, Tabasco, Tamaulipas, Veracruz, and Yucatán. However, no complete compendium exists summarizing the locality-level distribution of A. sagrei in Mexico. Herein we provide an exhaustive compilation of vouchered Mexican specimens based on museum records and the literature. Supplementing this review are reports of five new localities for A. sagrei in Veracruz and Tabasco. We conclude with brief comments on the potential ecological effects of this species in Mexico

    ITACA: An open-source framework for Neurofeedback based on Brain-Computer Interfaces

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    Producción CientíficaNeurofeedback (NF) is a paradigm that allows users to self-modulate patterns of brain activity. It is implemented with a closed-loop brain-computer interface (BCI) system that analyzes the user’s brain activity in real-time and provides continuous feedback. This paradigm is of great interest due to its potential as a non-pharmacological and non-invasive alternative to treat non-degenerative brain disorders. Nevertheless, currently available NF frameworks have several limitations, such as the lack of a wide variety of real-time analysis metrics or overly simple training scenarios that may negatively affect user performance. To overcome these limitations, this work proposes ITACA: a novel open-source framework for the design, implementation and evaluation of NF training paradigms.Ministerio de Ciencia e innovación, Agencia Estatal de Investigación y FEDER (PID2020-115468RB-I00, RTC2019-007350-1 y TED2021-129915B-I00

    The Role of Women in a Family Economy. A Bibliometric Analysis in Contexts of Poverty

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    The concept of family economy in the context of extreme poverty is of interest when it comes to analyzing the strategies displayed to prevent or reduce the effects of this situation of exclusion. Gender roles in the nucleus of the family institution will indicate the distribution of these tasks, so that we can understand, in the case of the role of women, the specific weight of their actions in this scenario. For this work, an investigation of our object of study was carried out for the period 1968–2019. A bibliometric analysis of 2182 articles was carried out in which the final versions of articles, books, and book chapters whose subject matter was related to the categories of family economy and poverty were included. The most productive journal was the Journal of Development Economics, while World Economies was the most cited. The authors with the most articles were Ravaillon, Sadoulet, and Lanjouw. The most productive institution was the World Bank. The country with the most publications and citations was the United States. Future research should focus on analyzing the role of women within the family economy in the context of poverty. Thus, a line of research is proposed that also includes the proposals from the 2030 Agenda for Sustainable Development and its 17 Sustainable Development Goals, which means an urgent call for action by all countries

    Non-binary m-sequences for more comfortable brain–computer interfaces based on c-VEPs

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    Producción CientíficaCode-modulated visual evoked potentials (c-VEPs) have marked a milestone in the scientific literature due to their ability to achieve reliable, high-speed brain–computer interfaces (BCIs) for communication and control. Generally, these expert systems rely on encoding each command with shifted versions of binary pseudorandom sequences, i.e., flashing black and white targets according to the shifted code. Despite the excellent results in terms of accuracy and selection time, these high-contrast stimuli cause eyestrain for some users. In this work, we propose the use of non-binary p-ary m-sequences, whose levels are encoded with different shades of gray, as a more pleasant alternative than traditional binary codes. The performance and visual fatigue of these p-ary m-sequences, as well as their ability to provide reliable c-VEP-based BCIs, are analyzed for the first time.Ministerio de Ciencia e Innovación/AEI- FEDER [TED2021-129915B-I00, RTC2019-007350-1 y PID2020-115468RB-I00

    Using a new high-throughput video-tracking platform to assess behavioural changes in Daphnia magna exposed to neuro-active drugs

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    © 2019. ElsevierOne of the major challenges that faces today regulatory risk assessment is to speed up the way of assessing threshold sublethal detrimental effects of existing and new chemical products. Recently advances in imaging allows to monitor in real time the behaviour of individuals under a given stress. Light is a common stress for many different organisms. Fish larvae and many invertebrate species respond to light altering their behaviour. The water flea Daphnia magna as many other zooplanktonic species has a marked diel vertical phototactic swimming behaviour against light due to fish predation. The aim of this study was to develop a high throughput image analysis to study changes in the vertical swimming behaviour to light of D. magna first reproductive adult females exposed to 0.1 and 1 µg/L of four psychiatric drugs: diazepam, fluoxetine, propranolol and carbamazepine during their entire life. Experiments were conducted using a new custom designed vertical oriented four 50 mL chamber device controlled by the Noldus software (Netherlands). Changes in speed, preferred area (bottom vs upper areas) and animal aggregation were analysed using groups of animals under consecutive periods of dark and apical light stimulus of different intensities. Obtained results indicated that light intensity increased the speed but low light intensities allowed to better discriminate individual responses to the studied drugs. The four tested drugs decreased the response of exposed organisms to light: individuals move less, were closer to the bottom and at low light intensities were closer each other. At high light intensities, however, exposed individuals were less aggregated. Propranolol, carbamazepine and fluoxetine were the compounds effecting most the behaviour. Our results indicated that psychiatric drugs at environmental relevant concentrations alter the vertical phototactic behaviour of D. magna individuals and that it is possible to develop appropriate high-throughput image analysis devices to measure those responses.Peer ReviewedPostprint (author's final draft
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