Lluitar contra els virus a les granges seguint la seva evolució filogenètica

La irrupció de l'anàlisi genètica com a mètode de diagnosi de malalties ha suposat un avenç important del que la indústria ramadera s'està beneficiant. L'estudi de les seqüències de nucleòtids dels virus permet fer reconstruccions filogenètiques que permetran deduir característiques d'aquests agents patògens, podent seguir l'evolució del virus i traçar l'origen d'un brot. Aquests tipus d'estudis permetran, en un futur, controlar amb èxit les malalties a les granjes.La irrupción del análisis genético como método de diagnóstico de enfermedades ha supuesto un avance importante, algo de lo que la industria ganadera se está beneficiando. El estudio de las secuencias de nucleótidos de los virus permite hacer reconstrucciones filogenéticas que permitirán deducir características de estos agentes patógenos, pudiendo seguir la evolución del virus y trazar el origen de un brote. Este tipo de estudio permitirán, en un futuro, controlar exitosamente las enfermedades a las granjas

Improving Stability Prediction in Peripheral Milling of Al7075T6

Chatter is an old enemy to machinists but, even today, is far from being defeated. Current requirements around aerospace components call for stronger and thinner workpieces which are more prone to vibrations. This study presents the stability analysis for a single degree of freedom down-milling operation in a thin-walled workpiece. The stability charts were computed by means of the enhanced multistage homotopy perturbation (EMHP) method, which includes the helix angle but also, most importantly, the runout and cutting speed effects. Our experimental validation shows the importance of this kind of analysis through a comparison with a common analysis without them, especially when machining aluminum alloys. The proposed analysis demands more computation time, since it includes the calculation of cutting forces for each combination of axial depth of cut and spindle speed. This EMHP algorithm is compared with the semi-discretization, Chebyshev collocation, and full-discretization methods in terms of convergence and computation efficiency, and ultimately proves to be the most efficient method among the ones studied.The authors wish to acknowledge the financial support received from HAZITEK program, from the Department of Economic Development and Infrastructures of the Basque Government and from FEDER funds. Additional support was provided by the Tecnologico de Monterrey, through the Research Group in Nanomaterials and Devices Design

Political Participation in Latin America

En este simposio se busca responder a las siguientes preguntas:1. Fundamentos de la participación. Partiendo de la base de que debe haber participación de la ciudadanía en los asuntos públicos ¿cuáles serían, a su juicio, los fundamentos de esta participación, ya sea desde la teoría democrática o desde los derechos humanos? ¿En qué debiera consistir entonces la participación?2. Mecanismos de participación. Entre los mecanismos de participación ciudadana normalmente utilizados ¿hay alguno que usted considere  particularmente valioso o, por el contrario, que haya demostrado su falta de efectividad o sus efectos perversos a la luz de los derechos humanos?3. Déficits en la participación y protestas sociales. ¿Qué diagnóstico haría usted respecto de las fortalezas y déficits de los mecanismos de participación en  América Latina? ¿Son las protestas sociales un signo de que los mecanismos de participación tradicionales no están funcionando como debieran, de que no  existen suficientes canales para participar, o pueden considerarse estas protestas como una vía más de participación?4. Participación a nivel local, nacional e internacional. La participación puede darse en distintos niveles: local, regional, nacional o incluso a nivel  internacional. ¿Qué desafíos se le plantean a las estrategias de participación en una sociedad globalizada, donde las instancias de poder parecen cada vez más alejadas no solo de la ciudadanía, sino también de las instancias nacionalesde decisión?In this symposium, the following issues are analyzed:1. Theoretical grounds for participation2. Participation mechanisms3. Deficits in participation and social demonstrations4. Participation at the local, national and international level

Estimation of the capacitor voltages in flying capacitor multi-level converters

Flying capacitor multi-level converters use charged capacitors as a critical element. For proper operation, the capacitor voltages must be known and regulated. Direct measurement is straightforward, but when the number of required measurements is high, this is a complicated approach. This paper introduces an estimation method for n capacitor voltages. The scheme is based on a system of (n + 1) equations, which is defined in a way that it incorporates information of the actual capacitor voltages and open-loop estimates of the capacitor voltages. The solution of the system gives the best estimates of the capacitor voltages in the sense of least square errors. The method requires only output voltage and output current sensors and its computational burden is low, saving cost and design efforts, and simplifying the hardware system. The performance of the proposed scheme is evaluated experimentally in a 9-level flying capacitor chopper, where the estimates are used by the voltage balancing strategy and by the output current controller

Evaluation of the Thermal Stability of a Vaccine Prototype Based on Virus-like Particle Formulated HIV-1 Envelope

The long-term storage stability of vaccines has a major impact on the roll-out and success of global immunization programs. For the Human Immunodeficiency Virus type 1 (HIV-1) virus-like particle (VLP) vaccine prototype evaluated here, nanoparticle tracking analysis (NTA), and enzyme-linked immunoabsorbent assay (ELISA) results demonstrated a remarkable structural stability. VLPs maintained their integrity and the recognition of relevant B-cell epitopes for three months at 4 and -20 °C. Interestingly, most particles remained intact and preserved the recognition of relevant epitopes even after a week of storage at room temperature.This research was funded by Instituto de Salud Carlos III within the Spanish AIDS Research Network (RIS), grant number RD16CIII/0002/0001 (Plan Estatal de I + D + I 2013-2016) and cofunded by European Regional Development Fund (ERDF) “A way to build Europe”. This study was also supported by the Spanish Ministry of Science, Innovation and University, Instituto de Salud Carlos III [PI17CIII-00049 (MPY126/18)] and the Spanish Ministry of Science and Innovation, Instituto de Salud Carlos III [PI20CIII-00039 (MPY315/20)]. This project has received funding from the European Union’s Horizon 2020 research and innovation program under grant agreement no. 681137 (EAVI-2020).S

Prediction Methods and Experimental Techniques for Chatter Avoidance in Turning Systems: A Review

The general trend towards lightweight components and stronger but difficult to machine materials leads to a higher probability of vibrations in machining systems. Amongst them, chatter vibrations are an old enemy for machinists with the most dramatic cases resulting in machine-tool failure, accelerated tool wear and tool breakage or part rejection due to unacceptable surface finish. To avoid vibrations, process designers tend to command conservative parameters limiting productivity. Among the different machining processes, turning is responsible of a great amount of the chip volume removed worldwide. This paper reports some of the main efforts from the scientific literature to predict stability and to avoid chatter with special emphasis on turning systems. There are different techniques and approaches to reduce and to avoid chatter effects. The objective of the paper is to summarize the current state of research in this hot topic, particularly (1) the mechanistic, analytical, and numerical methods for stability prediction in turning; (2) the available techniques for chatter detection and control; (3) the main active and passive techniques.Thanks are addressed to Basque country university excellence group IT1337-19. The authors wish to acknowledge also the financial support received from HAZITEK program, from the Department of Economic Development and Infrastructures of the Basque Government and from FEDER funds. This research was funded by Tecnologico de Monterrey through the Research Group of Nanotechnology for Devices Design, and by the Consejo Nacional de Ciencia y Tecnologia (CONACYT), Project Numbers 242269, 255837, 296176, and the National Lab in Additive Manufacturing, 3D Digitizing and Computed Tomography (MADiT) LN299129

Hierarchical Modeling for Diagnostic Test Accuracy Using Multivariate Probability Distribution Functions

[EN] Models implemented in statistical software for the precision analysis of diagnostic tests include random-effects modeling (bivariate model) and hierarchical regression (hierarchical summary receiver operating characteristic). However, these models do not provide an overall mean, but calculate the mean of a central study when the random effect is equal to zero; hence, it is difficult to calculate the covariance between sensitivity and specificity when the number of studies in the meta-analysis is small. Furthermore, the estimation of the correlation between specificity and sensitivity is affected by the number of studies included in the meta-analysis, or the variability among the analyzed studies. To model the relationship of diagnostic test results, a binary covariance matrix is assumed. Here we used copulas as an alternative to capture the dependence between sensitivity and specificity. The posterior values were estimated using methods that consider sampling algorithms from a probability distribution (Markov chain Monte Carlo), and estimates were compared with the results of the bivariate model, which assumes statistical independence in the test results. To illustrate the applicability of the models and their respective comparisons, data from 14 published studies reporting estimates of the accuracy of the Alcohol Use Disorder Identification Test were used. Using simulations, we investigated the performance of four copula models that incorporate scenarios designed to replicate realistic situations for meta-analyses of diagnostic accuracy of the tests. The models’ performances were evaluated based on p-values using the Cramér–von Mises goodness-of-fit test. Our results indicated that copula models are valid when the assumptions of the bivariate model are not fulfilled

A model-based sustainable productivity concept for the best decision-making in rough milling operations

[EN]There is a need in manufacturing as in machining of being more productive. However, at the same time, workshops are also urged for lesser energy waste in cutting operations. Specially, rough milling of impellers and bladed integrated disks of aircraft engines need an efficient use of energy due to the long cycle times. Indeed, to avoid dramatic tool failures and idle times, cutting conditions and operations tend to be very conservative. This is a multivariable problem, where process engineers need to handle several aspects such as milling operation type, toolpath strategies, cutting conditions, or clamping systems. There is no criterion embracing productivity and power consumption. In this sense, this work proposes a methodology that meets productivity and sustainability by using a specific cutting energy or sustainable productivity gain (SPG) factor. Three rough milling operations-slot, plunge nad trochoidal milling-were modelled and verified. A bottom-up approach based on data from developed mechanistic force models evaluated and compared different alternatives for making a slot, which is a common operation in that king of workpieces. Experimental data confirmed that serrated end milling with the highest SPG value of 1 is the best milling operation in terms of power consumption and mass removal rate (MRR). In the case of plunge milling technique achieve an SPG < 0.51 while trochoidal milling produces a very low SPG value.The authors acknowledge the support from the Spanish Government (JANO, CIEN Project, 2019.0760) and Basque Government (ELKARTEK19/46, KK-2019/00004). This research was funded by Tecnologico de Monterrey through the Research Group of Nanotechnology for Devices Design, and by the Consejo Nacional de Ciencia y Tecnologia de Mexico (Conacyt), Project Number 296176, and National Lab in Additive Manufacturing, 3D Digitizing and Computed Tomography (MADiT) LN299129. The authors also acknowledge the support from Garikoitz Goikoetxea and fruitful discussions with Mr. Jon Mendez (Guhring (c)) and Endika Monge (Hoffmann Group (c))

Equivalent Representation Form of Oscillators with Elastic and Damping Nonlinear Terms

In this work we consider the nonlinear equivalent representation form of oscillators that exhibit nonlinearities in both the elastic and the damping terms. The nonlinear damping effects are considered to be described by fractional power velocity terms which provide better predictions of the dissipative effects observed in some physical systems. It is shown that their effects on the system dynamics response are equivalent to a shift in the coefficient of the linear damping term of a Duffing oscillator. Then, its numerical integration predictions, based on its equivalent representation form given by the well-known forced, damped Duffing equation, are compared to the numerical integration values of its original equations of motion. The applicability of the proposed procedure is evaluated by studying the dynamics response of four nonlinear oscillators that arise in some engineering applications such as nanoresonators, microresonators, human wrist movements, structural engineering design, and chain dynamics of polymeric materials at high extensibility, among others