Sampling C-obstacles border using a filtered deterministic sequence

This paper is focused on the sampling process for path planners based on probabilistic roadmaps. The paper first analyzes three sampling sources: the random sequence and two deterministic sequences, Halton and sd(k), and compares them in terms of dispersion, computational efficiency (including the finding of nearest neighbors), and sampling probabilities. Then, based on this analysis and on the recognized success of the Gaussian sampling strategy, the paper proposes a new efficient sampling strategy based on deterministic sampling that also samples more densely near the C-obstacles. The proposal is evaluated and compared with the original Gaussian strategy in both 2D and 3D configuration spaces, giving promising results

Programming assignments to learn how to build a Probabilistic Roadmap Planner

Research in robot motion planning requires the availability of a simulation environment where to test and validate the theoretic contributions. Nevertheless, PhD programs and graduate studies that include robot motion planning courses usually cover the subject only from a theoretical perspective. Therefore, students aiming to focus their research in this line, face the big challenge of developing their own simulation environment. To cope with this problem, this paper proposes the use of a programming framework based on multi-platform open source code, and presents a set of twelve programming assignments to allow students of any robot motion planning course a quick mastering of the basic skills involved, covering from graphical rendering issues to collision detection or graph representations and algorithms

A roadmap to robot motion planning software development

"This is the peer reviewed version of the following article: Pérez, A. and Rosell, J. (2010), A roadmap to robot motion planning software development. Comput. Appl. Eng. Educ., 18: 651-660. doi:doi.org/10.1002/cae.20269, which has been published in final form at https://doi.org/10.1002/cae.20269. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Self-Archiving."PhD programs and graduate studies in robotics usually include motion planning among its main subjects. Students that focus their research in this subject find themselves trapped in the necessity of programming an environment where to test and validate their theoretic contributions. The programming of this robot motion planning environment is a big challenge. It requires on the one hand good programming skills involving the use of software development tools, programming paradigms, or the knowledge of computational complexity and efficiency issues. On the other hand it requires coping with different related issues like the modeling of objects, computational geometry problems and graphical representations and interfaces. The mastering of all these techniques is good for the curricula of roboticists with a motion planning profile. Nevertheless, the time and effort devoted to this end must remain reasonable. Within this framework, the aim of this paper is to provide the students with a roadmap to help them in the development of the software tools needed to test and validate their robot motion planners. The proposals are made within the scope of multi-platform open source codePeer ReviewedPostprint (author's final draft

The spread of media content through blogs

Blogs are a popular way to share personal journals, discuss matters of public opinion, pursue collaborative conversations, and aggregate content on similar topics. Blogs can be also used to disseminate new content and novel ideas to communities of interest. In this paper, we present an analysis of the topological structure and the patterns of popular media content that is shared in blogs. By analyzing 8.7 million posts of 1.1 million blogs across 15 major blog hosting sites, we find that the network structure of blogs is “less social” compared to other online social networks: most links are unidirectional and the network is sparsely connected. The type of content that was popularly shared on blogs was surprisingly different from that from the mainstream media: user generated content, often in the form of videos or photos, was the most common type of content disseminated in blogs. The user-generated content showed interesting viral-spreading patterns within blogs. Topical content such as news and political commentary spreads quickly by the hour and then quickly disappears, while non-topical content such as music and entertainment propagates slowly over a much long period of time

IAMBEE : a web-service for the identification of adaptive pathways from parallel evolved clonal populations

IAMBEE is a web server designed for the Identification of Adaptive Mutations in Bacterial Evolution Experiments (IAMBEE). Input data consist of genotype information obtained from independently evolved clonal populations or strains that show the same adapted behavior (phenotype). To distinguish adaptive from passenger mutations, IAMBEE searches for neighborhoods in an organism-specific interaction network that are recurrently mutated in the adapted populations. This search for recurrently mutated network neighborhoods, as proxies for pathways is driven by additional information on the functional impact of the observed genetic changes and their dynamics during adaptive evolution. In addition, the search explicitly accounts for the differences in mutation rate between the independently evolved populations. Using this approach, IAMBEE allows exploiting parallel evolution to identify adaptive pathways. The web-server is freely available at http://bioinformatics.intec.ugent.be/iambee/ with no login requirement

C-space decomposition using deterministic sampling and distances

Hierarchical cell decompositions of Configuration Space can be of great value for enhancing sampling-based path planners, as well as for other robotic tasks with requirements beyond the planning of free paths. This paper proposes an efficient method to obtain a hierarchical cell decomposition of C-space that is based on: a) the use of a deterministic sampling sequence that allows an uniform and incremental exploration of the space, and b) the use of distance measurements to handle as much information as possible from each sample in order to make the procedure more efficient. The proposed cell decomposition procedure is applied to different path planning methods.Peer Reviewe

Un análisis crítico sobre las recomendaciones de actividad física en España

ResumenObjetivoIdentificar los documentos oficiales de las comunidades autónomas en España que contengan recomendaciones sobre actividad física, para evaluar el grado de conformidad con las recomendaciones sobre actividad física para la salud de la Organización Mundial de la Salud (OMS).MétodosSe realizó un análisis de contenido sobre 55 documentos de las consejerías de sanidad de los distintos gobiernos autonómicos que contienen recomendaciones sobre actividad física.ResultadosEl 84% de las comunidades autónomas en España hacen algún tipo de recomendación sobre actividad física aeróbica y el 37% sobre fortalecimiento muscular. Sin embargo, las que tienen documentos en consonancia con los criterios de la OMS son: actividad física aeróbica (n=11, 58%), personas adultas (n=10, 53%), personas mayores (n=5, 26%), infancia/adolescentes (n=1, 5%); fortalecimiento muscular, personas adultas (n=6, 32%), personas mayores (n=3, 16%), infancia/adolescentes (n=1, 5%); equilibrio (n=5, 26%); al menos 10 minutos continuados de actividad física (n=6, 32%); recomiendan hasta 300 minutos semanales (n=10, 53%); intensidad de la actividad física (n=2, 11%).ConclusionesLas recomendaciones hacen referencia a la actividad física aeróbica y apenas tienen en cuenta el fortalecimiento muscular. Una comunidad autónoma se ajusta a las recomendaciones de la OMS. Las comunidades con mayores índices de envejecimiento y mayor porcentaje de infancia/adolescentes casi no hacen recomendaciones sobre actividad física de acuerdo con las directrices de la OMS.AbstractObjectiveTo identify official documents with recommendations on physical activity published by the autonomous regions of Spain with the goal of evaluating their compliance with the physical activity recommendations of the World Health Organization (WHO).MethodsWe conducted a content analysis of 55 documents of the ministries of health of several regional governments containing recommendations on physical activity.ResultsEighty-four percent of the autonomous regions in Spain made recommendations on aerobic physical activity and 37% made recommendations on strength training. However, the number of documents consistent with the WHO criteria was as follows: aerobic activity (n=11, 58%), adults (n=10, 53%), the elderly (n=5, 26%), children/adolescents (n=1, 5%); strength training, adults (n=6, 32%), the elderly (n=3, 16%), children/adolescents (n=1, 5%); balance (n=5, 26%); at least 10minutes continuous physical activity (n=6, 32%); recommendation of up to 300minutes per week (n=10, 53%); intensity of physical activity (n=2, 11%).ConclusionsThe recommendations of the autonomous regions tend to focus on aerobic physical activity and to under-represent strength training. Moreover, only one autonomous region conforms to the WHO recommendations for physical activity. The regions with higher rates of population aging and a higher percentage of children and adolescents fail to make recommendations on physical activity consistent with the WHO guidelines

The Iturin and Fengycin Families of Lipopeptides Are Key Factors in Antagonism of Bacillus subtilis Toward Podosphaera fusca

Podosphaera fusca is the main causal agent of cucurbit powdery mildew in Spain. Four Bacillus subtilis strains, UMAF6614, UMAF6619, UMAF6639, and UMAF8561, with proven ability to suppress the disease on melon in detached leaf and seedling assays, were subjected to further analyses to elucidate the mode of action involved in their biocontrol performance. Cell-free supernatants showed antifungal activities very close to those previously reported for vegetative cells. Identification of three lipopeptide antibiotics, surfactin, fengycin, and iturin A or bacillomycin, in butanolic extracts from cell-free culture filtrates of these B. subtilis strains pointed out that antibiosis could be a major factor involved in their biocontrol ability. The strong inhibitory effect of purified lipopeptide fractions corresponding to bacillomycin, fengycin, and iturin A on P. fusca conidia germination, as well as the in situ detection of these lipopeptides in bacterial-treated melon leaves, provided interesting evidence of their putative involvement in the antagonistic activity. Those results were definitively supported by site-directed mutagenesis analysis, targeted to suppress the biosynthesis of the different lipopeptides. Taken together, our data have allowed us to conclude that the iturin and fengycin families of lipopeptides have a major role in the antagonism of B. subtilis toward P. fusca.

SDK: A proposal of a general and efficient deterministic sampling sequence

Previous works have already demonstrated that deterministic sampling can be competitive with respect to probabilistic sampling in sampling-based path planners. Nevertheless, the definition of a general sampling sequence for any d-dimensional Configuration Space satisfying the requirements needed for path planning is not a trivial issue, over a multi-grid cell decomposition, of the ordering of the 2d descendant cells of any parent cell. This ordering is generated by the digital construction method using a d x d matrix Td. A general expression of this matrix (i.e. for any d) is introduced and its performance analyzed in terms of the mutual distance. The paper ends with a performance evaluation of the use of the proposed deterministic sampling sequence in different well know path planner