32 research outputs found
RoboCup 2D Soccer Simulation League: Evaluation Challenges
We summarise the results of RoboCup 2D Soccer Simulation League in 2016
(Leipzig), including the main competition and the evaluation round. The
evaluation round held in Leipzig confirmed the strength of RoboCup-2015
champion (WrightEagle, i.e. WE2015) in the League, with only eventual finalists
of 2016 competition capable of defeating WE2015. An extended, post-Leipzig,
round-robin tournament which included the top 8 teams of 2016, as well as
WE2015, with over 1000 games played for each pair, placed WE2015 third behind
the champion team (Gliders2016) and the runner-up (HELIOS2016). This
establishes WE2015 as a stable benchmark for the 2D Simulation League. We then
contrast two ranking methods and suggest two options for future evaluation
challenges. The first one, "The Champions Simulation League", is proposed to
include 6 previous champions, directly competing against each other in a
round-robin tournament, with the view to systematically trace the advancements
in the League. The second proposal, "The Global Challenge", is aimed to
increase the realism of the environmental conditions during the simulated
games, by simulating specific features of different participating countries.Comment: 12 pages, RoboCup-2017, Nagoya, Japan, July 201
Gliders2d: Source Code Base for RoboCup 2D Soccer Simulation League
We describe Gliders2d, a base code release for Gliders, a soccer simulation
team which won the RoboCup Soccer 2D Simulation League in 2016. We trace six
evolutionary steps, each of which is encapsulated in a sequential change of the
released code, from v1.1 to v1.6, starting from agent2d-3.1.1 (set as the
baseline v1.0). These changes improve performance by adjusting the agents'
stamina management, their pressing behaviour and the action-selection
mechanism, as well as their positional choice in both attack and defense, and
enabling riskier passes. The resultant behaviour, which is sufficiently generic
to be applicable to physical robot teams, increases the players' mobility and
achieves a better control of the field. The last presented version,
Gliders2d-v1.6, approaches the strength of Gliders2013, and outperforms
agent2d-3.1.1 by four goals per game on average. The sequential improvements
demonstrate how the methodology of human-based evolutionary computation can
markedly boost the overall performance with even a small number of controlled
steps.Comment: 12 pages, 1 figure, Gliders2d code releas
Functional transcription factor target discovery via compendia of binding and expression profiles
Genome-wide experiments to map the DNA-binding locations of
transcription-associated factors (TFs) have shown that the number of genes
bound by a TF far exceeds the number of possible direct target genes.
Distinguishing functional from non-functional binding is therefore a major
challenge in the study of transcriptional regulation. We hypothesized that
functional targets can be discovered by correlating binding and expression
profiles across multiple experimental conditions. To test this hypothesis, we
obtained ChIP-seq and RNA-seq data from matching cell types from the human
ENCODE resource, considered promoter-proximal and distal cumulative regulatory
models to map binding sites to genes, and used a combination of linear and
non-linear measures to correlate binding and expression data. We found that a
high degree of correlation between a gene's TF-binding and expression profiles
was significantly more predictive of the gene being differentially expressed
upon knockdown of that TF, compared to using binding sites in the cell type of
interest only. Remarkably, TF targets predicted from correlation across a
compendium of cell types were also predictive of functional targets in other
cell types. Finally, correlation across a time course of ChIP-seq and RNA-seq
experiments was also predictive of functional TF targets in that tissue.Comment: 15 pages + 8 pages supplementary material; 6 figures, 6 supplementary
figures, 5 supplementary table
Fluoride inhibits the response of bone cells to mechanical loading
The response of bone cells to mechanical loading is mediated by the cytoskeleton. Since the bone anabolic agent fluoride disrupts the cytoskeleton, we investigated whether fluoride affects the response of bone cells to mechanical loading, and whether this is cytoskeleton mediated. The mechano-response of osteoblasts was assessed in vitro by measuring pulsating fluid flow-induced nitric oxide (NO) production. Osteocyte shape was determined in hamster mandibles in vivo as parameter of osteocyte mechanosensitivity. Pulsating fluid flow (0.7 ± 0.3 Pa, 5 Hz) stimulated NO production by 8-fold within 5 min. NaF (10-50 μM) inhibited pulsating fluid flow-stimulated NO production after 10 min, and decreased F-actin content by ~3-fold. Fluid flow-induced NO response was also inhibited after F-actin disruption by cytochalasin B. NaF treatment resulted in more elongated, smaller osteocytes in interdental bone in vivo. Our results suggest that fluoride inhibits the mechano-response of bone cells, which might occur via cytoskeletal changes. Since decreased mechanosensitivity reduces bone mass, the reported anabolic effect of fluoride on bone mass in vivo is likely mediated by other factors than changed bone cell mechanosensitivity. © 2011 The Society of The Nippon Dental University
Distributed gene expression modelling for exploring variability in epigenetic function
BACKGROUND: Predictive gene expression modelling is an important tool in computational biology due to the volume of high-throughput sequencing data generated by recent consortia. However, the scope of previous studies has been restricted to a small set of cell-lines or experimental conditions due an inability to leverage distributed processing architectures for large, sharded data-sets. RESULTS: We present a distributed implementation of gene expression modelling using the MapReduce paradigm and prove that performance improves as a linear function of available processor cores. We then leverage the computational efficiency of this framework to explore the variability of epigenetic function across fifty histone modification data-sets from variety of cancerous and non-cancerous cell-lines. CONCLUSIONS: We demonstrate that the genome-wide relationships between histone modifications and mRNA transcription are lineage, tissue and karyotype-invariant, and that models trained on matched -omics data from non-cancerous cell-lines are able to predict cancerous expression with equivalent genome-wide fidelity
Information theoretic approaches for inference of biological networks from continuous-valued data
BACKGROUND: Characterising programs of gene regulation by studying individual protein-DNA and protein-protein interactions would require a large volume of high-resolution proteomics data, and such data are not yet available. Instead, many gene regulatory network (GRN) techniques have been developed, which leverage the wealth of transcriptomic data generated by recent consortia to study indirect, gene-level relationships between transcriptional regulators. Despite the popularity of such methods, previous methods of GRN inference exhibit limitations that we highlight and address through the lens of information theory. RESULTS: We introduce new model-free and non-linear information theoretic measures for the inference of GRNs and other biological networks from continuous-valued data. Although previous tools have implemented mutual information as a means of inferring pairwise associations, they either introduce statistical bias through discretisation or are limited to modelling undirected relationships. Our approach overcomes both of these limitations, as demonstrated by a substantial improvement in empirical performance for a set of 160 GRNs of varying size and topology. CONCLUSIONS: The information theoretic measures described in this study yield substantial improvements over previous approaches (e.g. ARACNE) and have been implemented in the latest release of NAIL (Network Analysis and Inference Library). However, despite the theoretical and empirical advantages of these new measures, they do not circumvent the fundamental limitation of indeterminacy exhibited across this class of biological networks. These methods have presently found value in computational neurobiology, and will likely gain traction for GRN analysis as the volume and quality of temporal transcriptomics data continues to improve
Virtual Reference Environments: a simple way to make research reproducible
'Reproducible research' has received increasing attention over the past few years as bioinformatics and computational biology methodologies become more complex. Although reproducible research is progressing in several valuable ways, we suggest that recent increases in internet bandwidth and disk space, along with the availability of open-source and free-software licences for tools, enable another simple step to make research reproducible. In this article, we urge the creation of minimal virtual reference environments implementing all the tools necessary to reproduce a result, as a standard part of publication. We address potential problems with this approach, and show an example environment from our own work