Breeding value estimation for somatic cell score in South African dairy cattle

Two fixed regression testday models were applied for variance component estimation and prediction of breeding values for somatic cell score, using testday records of the first three lactations of South African Holstein and Jersey cows. The first model (ML-model) considered the testdays of the different lactations as different traits in a multiple-trait animal model and the second analysis (RM-model) treated later lactation records as repeated measures of the first lactation. Heritabilities from the RM-model were more in the range of literature estimates compared to that of the ML-model, i.e. 0.19 + 0.003 for the Holstein breed and 0.18 + 0.003 for the Jersey breed. Rank correlations indicated that minor changes occur in the ranking of proven sires between breeding values obtained from the ML- and RM-models. Although genetic correlations between parities are not unity, the RM-model estimates more competitive variances and requires extensively less computer time to predict breeding values compared to the ML-model and are therefore recommended for breeding value estimation on a national basis. South African Journal of Animal Science Supp 2 2004: 32-3

Urban Cholera transmission hotspots and their implications for Reactive Vaccination: evidence from Bissau city, Guinea Bissau

Use of cholera vaccines in response to epidemics (reactive vaccination) may provide an effective supplement to traditional control measures. In Haiti, reactive vaccination was considered but, until recently, rejected in part due to limited global supply of vaccine. Using Bissau City, Guinea-Bissau as a case study, we explore neighborhood-level transmission dynamics to understand if, with limited vaccine and likely delays, reactive vaccination can significantly change the course of a cholera epidemic

Una visión general sobre la implementación de metaheurísticas paralelas en la nube

Metaheuristics are among the most popular methods for solving hard global optimization problems in many areas of science and engineering. Their parallel implementation applying HPC techniques is a common approach for efficiently using available resources to reduce the time needed to get a good enough solution to hard-to-solve problems. Paradigms like MPI or OMP are the usual choice when executing them in clusters or supercomputers. Moreover, the pervasive presence of cloud computing and the emergence of programming models like MapReduce or Spark have given rise to an increasing interest in porting HPC workloads to the cloud, as is the case with parallel metaheuristics. In this paper we give an overview of our experience with different alternatives for porting parallel metaheuristics to the cloud, providing some useful insights to the interested reader that we have acquired through extensive experimentation.Las metaheurísticas son uno de los métodos más populares en muchas áreas de la ciencia y la ingeniera para la resolución de problemas de optimización global difíciles. Su implementación paralela, aplicando técnicas de HPC, es una aproximación común a la hora de reducir el tiempo necesario para obtener una solución lo suficientemente buena con un uso eficiente de los recursos disponibles. Paradigmas como MPI u OMP son las opciones habituales cuando se ejecutan en clústeres o supercomputadores. Además, la utilización generalizada de la computación en la nube y la aparición de modelos de programación como MapReduce o Spark, han generado un interés creciente por portar aplicaciones HPC a la nube, como ocurre en el caso de las metaheursticas paralelas. En este trabajo recogemos una visión general de nuestra experiencia con diferentes opciones a la hora de portar metaheursticas paralelas a la nube, proporcionando información útil al lector interesado, que hemos ido adquiriendo a través de nuestra experiencia practica.Facultad de Informátic

Implementing cloud-based parallel metaheuristics: an overview

[Abstract] Metaheuristics are among the most popular methods for solving hard global optimization problems in many areas of science and engineering. Their parallel im- plementation applying HPC techniques is a common approach for efficiently using available resources to re- duce the time needed to get a good enough solution to hard-to-solve problems. Paradigms like MPI or OMP are the usual choice when executing them in clusters or supercomputers. Moreover, the pervasive presence of cloud computing and the emergence of programming models like MapReduce or Spark have given rise to an increasing interest in porting HPC workloads to the cloud, as is the case with parallel metaheuristics. In this paper we give an overview of our experience with different alternatives for porting parallel metaheuris- tics to the cloud, providing some useful insights to the interested reader that we have acquired through extensive experimentation.Gobierno de España; DPI2017-82896-C2-2-RGobierno de España; TIN2016-75845-PXunta de Galicia; R2016/045Xunta de Galicia; ED431C 2017/0

Una visión general sobre la implementación de metaheurísticas paralelas en la nube

Metaheuristics are among the most popular methods for solving hard global optimization problems in many areas of science and engineering. Their parallel implementation applying HPC techniques is a common approach for efficiently using available resources to reduce the time needed to get a good enough solution to hard-to-solve problems. Paradigms like MPI or OMP are the usual choice when executing them in clusters or supercomputers. Moreover, the pervasive presence of cloud computing and the emergence of programming models like MapReduce or Spark have given rise to an increasing interest in porting HPC workloads to the cloud, as is the case with parallel metaheuristics. In this paper we give an overview of our experience with different alternatives for porting parallel metaheuristics to the cloud, providing some useful insights to the interested reader that we have acquired through extensive experimentation.Las metaheurísticas son uno de los métodos más populares en muchas áreas de la ciencia y la ingeniera para la resolución de problemas de optimización global difíciles. Su implementación paralela, aplicando técnicas de HPC, es una aproximación común a la hora de reducir el tiempo necesario para obtener una solución lo suficientemente buena con un uso eficiente de los recursos disponibles. Paradigmas como MPI u OMP son las opciones habituales cuando se ejecutan en clústeres o supercomputadores. Además, la utilización generalizada de la computación en la nube y la aparición de modelos de programación como MapReduce o Spark, han generado un interés creciente por portar aplicaciones HPC a la nube, como ocurre en el caso de las metaheursticas paralelas. En este trabajo recogemos una visión general de nuestra experiencia con diferentes opciones a la hora de portar metaheursticas paralelas a la nube, proporcionando información útil al lector interesado, que hemos ido adquiriendo a través de nuestra experiencia practica.Facultad de Informátic

Una visión general sobre la implementación de metaheurísticas paralelas en la nube

Metaheuristics are among the most popular methods for solving hard global optimization problems in many areas of science and engineering. Their parallel implementation applying HPC techniques is a common approach for efficiently using available resources to reduce the time needed to get a good enough solution to hard-to-solve problems. Paradigms like MPI or OMP are the usual choice when executing them in clusters or supercomputers. Moreover, the pervasive presence of cloud computing and the emergence of programming models like MapReduce or Spark have given rise to an increasing interest in porting HPC workloads to the cloud, as is the case with parallel metaheuristics. In this paper we give an overview of our experience with different alternatives for porting parallel metaheuristics to the cloud, providing some useful insights to the interested reader that we have acquired through extensive experimentation.Las metaheurísticas son uno de los métodos más populares en muchas áreas de la ciencia y la ingeniera para la resolución de problemas de optimización global difíciles. Su implementación paralela, aplicando técnicas de HPC, es una aproximación común a la hora de reducir el tiempo necesario para obtener una solución lo suficientemente buena con un uso eficiente de los recursos disponibles. Paradigmas como MPI u OMP son las opciones habituales cuando se ejecutan en clústeres o supercomputadores. Además, la utilización generalizada de la computación en la nube y la aparición de modelos de programación como MapReduce o Spark, han generado un interés creciente por portar aplicaciones HPC a la nube, como ocurre en el caso de las metaheursticas paralelas. En este trabajo recogemos una visión general de nuestra experiencia con diferentes opciones a la hora de portar metaheursticas paralelas a la nube, proporcionando información útil al lector interesado, que hemos ido adquiriendo a través de nuestra experiencia practica.Facultad de Informátic

Towards cloud-based parallel metaheuristics: A case study in computational biology with Differential Evolution and Spark

[Abstract] Many key problems in science and engineering can be formulated and solved using global optimization techniques. In the particular case of computational biology, the development of dynamic (kinetic) models is one of the current key issues. In this context, the problem of parameter estimation (model calibration) remains as a very challenging task. The complexity of the underlying models requires the use of efficient solvers to achieve adequate results in reasonable computation times. Metaheuristics have been the focus of great consideration as an efficient way of solving hard global optimization problems. Even so, in most realistic applications, metaheuristics require a very large computation time to obtain an acceptable result. Therefore, several parallel schemes have been proposed, most of them focused on traditional parallel programming interfaces and infrastructures. However, with the emergence of cloud computing, new programming models have been proposed to deal with large-scale data processing on clouds. In this paper we explore the applicability of these new models for global optimization problems using as a case study a set of challenging parameter estimation problems in systems biology. We have developed, using Spark, an island-based parallel version of Differential Evolution. Differential Evolution is a simple population-based metaheuristic that, at the same time, is very popular for being very efficient in real function global optimization. Several experiments were conducted both on a cluster and on the Microsoft Azure public cloud to evaluate the speedup and efficiency of the proposal, concluding that the Spark implementation achieves not only competitive speedup against the serial implementation, but also good scalability when the number of nodes grows. The results can be useful for those interested in using parallel metaheuristics for global optimization problems benefiting from the potential of new cloud programming models.Ministerio de Economía y Competitividad and FEDER; through the Project SYNBIOFACTORY; DPI2014-55276-C5-2-RMinisterio de Economía y Competitividad and FEDER; TIN2013-42148-PMinisterio de Economía y Competitividad and FEDER; TIN2016-75845-PXunta de Galicia; R2014/04

An Efficient Ant Colony Optimization Framework for HPC Environments

Financiado para publicación en acceso aberto: Universidade da Coruña/CISUG[Abstract] Combinatorial optimization problems arise in many disciplines, both in the basic sciences and in applied fields such as engineering and economics. One of the most popular combinatorial optimization methods is the Ant Colony Optimization (ACO) metaheuristic. Its parallel nature makes it especially attractive for implementation and execution in High Performance Computing (HPC) environments. Here we present a novel parallel ACO strategy making use of efficient asynchronous decentralized cooperative mechanisms. This strategy seeks to fulfill two objectives: (i) acceleration of the computations by performing the ants’ solution construction in parallel; (ii) convergence improvement through the stimulation of the diversification in the search and the cooperation between different colonies. The two main features of the proposal, decentralization and desynchronization, enable a more effective and efficient response in environments where resources are highly coupled. Examples of such infrastructures include both traditional HPC clusters, and also new distributed environments, such as cloud infrastructures, or even local computer networks. The proposal has been evaluated using the popular Traveling Salesman Problem (TSP), as a well-known NP-hard problem widely used in the literature to test combinatorial optimization methods. An exhaustive evaluation has been carried out using three medium and large size instances from the TSPLIB library, and the experiments show encouraging results with superlinear speedups compared to the sequential algorithm (e.g. speedups of 18 with 16 cores), and a very good scalability (experiments were performed with up to 384 cores improving execution time even at that scale).This work was supported by the Ministry of Science and Innovation of Spain (PID2019-104184RB-I00 / AEI / 10.13039/501100011033), and by Xunta de Galicia and FEDER funds of the EU (Centro de Investigación de Galicia accreditation 2019–2022, ref. ED431G 2019/01; Consolidation Program of Competitive Reference Groups, ref. ED431C 2021/30). JRB acknowledges funding from the Ministry of Science and Innovation of Spain MCIN / AEI / 10.13039/501100011033 through grant PID2020-117271RB-C22 (BIODYNAMICS), and from MCIN / AEI / 10.13039/501100011033 and “ERDF A way of making Europe” through grant DPI2017-82896-C2-2-R (SYNBIOCONTROL). Authors also acknowledge the Galician Supercomputing Center (CESGA) for the access to its facilities. Funding for open access charge: Universidade da Coruña/CISUGXunta de Galicia; ED431G 2019/01Xunta de Galicia; ED431C 2021/3

Multimethod Optimization for Reverse Engineering of Complex Biological Networks

Publication :PBio 2018: Proceedings of the 6th International Workshop on Parallelism in Bioinformatics[Abstract] Optimization problems appears in different areas of science and engineering. This paper considers the general problem of reverse engineering in computational biology by means of mixed-integer nonlinear dynamic optimization (MIDO). Although this kind of problems are typically hard, solutions can be achieved for rather complex networks by applying global optimization metaheuristics. The main objective of this work is to handle them by means of multimethod optimization, in which different metaheuristics cooperate to outperform the results obtained by any of them isolated. For its preliminary evaluation we consider a synthetic signaling pathway case study and we assess the performance of the proposal on a public cloud. These results open up new possibilities for other MIDO-based large-scale applications in computational systems biology.Gobierno de España; DPI2017-82896-C2-2-RGobierno de España; TIN2016-75845-PXunta de Galicia; R2016/045Xunta de Galicia; ED431C 2017/0

Multimethod optimization in the cloud: A case‐study in systems biology modelling

[Abstract] Optimization problems appear in many different applications in science and engineering. A large number of different algorithms have been proposed for solving them; however, there is no unique general optimization method that performs efficiently across a diverse set of problems. Thus, a multimethod optimization, in which different algorithms cooperate to outperform the results obtained by any of them in isolation, is a very appealing alternative. Besides, as real‐life optimization problems are becoming more and more challenging, the use of HPC techniques to implement these algorithms represents an effective strategy to speed up the time‐to‐solution. In addition, a parallel multimethod approach can benefit from the effortless access to q large number of distributed resources facilitated by cloud computing. In this paper, we propose a self‐adaptive cooperative parallel multimethod for global optimization. This proposal aims to perform a thorough exploration of the solution space by means of multiple concurrent executions of a broad range of search strategies. For its evaluation, we consider an extremely challenging case‐study from the field of computational systems biology. We also assess the performance of the proposal on a public cloud, demonstrating both the potential of the multimethod approach and the opportunity that the cloud provides for these problems.Gobierno de España; DPI2014‐55276‐C5‐2‐RGobierno de España; DPI2017‐82896‐C2‐2‐RGobierno de España; TIN2016‐75845‐PXunta de Galicia; R2016/045Xunta de Galicia; ED431C 2017/0