BOL: Related items

Surrogate Variable Analysis (SVA)

Jit — Thu, 30 Oct 2014 08:01:58 -0500

The sva package contains functions for removing batch effects and other unwanted variation in high-throughput experiment. Specifically, the sva package contains functions for the identifying and building surrogate variables for high-dimensional data sets. Surrogate variables are covariates constructed directly from high-dimensional data (like gene expression/RNA sequencing/methylation/brain imaging data) that can be used in subsequent analyses to adjust for unknown, unmodeled, or latent sources of noise. The sva package can be used to remove artifacts in three ways:

(1) identifying and estimating surrogate variables for unknown sources of variation in high-throughput experiments (Leek and Storey 2007 PLoS Genetics,2008 PNAS),

(2) directly removing known batch effects using ComBat (Johnson et al. 2007 Biostatistics) and

(3) removing batch effects with known control probes (Leek 2014 biorXiv).

Removing batch effects and using surrogate variables in differential expression analysis have been shown to reduce dependence, stabilize error rate estimates, and improve reproducibility, see (Leek and Storey 2007 PLoS Genetics, 2008 PNAS or Leek et al. 2011 Nat. Reviews Genetics).

More at http://www.bioconductor.org/packages/release/bioc/html/sva.html

Ph.D. student in Computational Systems Biology

Tue, 10 Dec 2013 18:46:05 -0600

Ph.D. student in Computational Systems Biology

Location : The Luxembourg Centre for Systems Biomedicine (LCSB) at the University of Luxembourg, Luxembourg, Luxembourg
Deadline for applications : unknown.
Description :

The Luxembourg Centre for Systems Biomedicine (LCSB) was created within the Health Technologies Initiative from the Government of Luxembourg as one of the research priorities of the University of Luxembourg. The LCSB is an Interdisciplinary Centre of the University that combines experimental and computational approaches to analyse complex biological systems and disease processes. The Computational Biology Group (CBG) provides the LCSB with a solid infrastructure in developing theoretical framework for computational modeling on biomedical problems, especially in the area of network biology in the context of cellular programming/reprogramming. The CBG group includes researchers with theoretical, computational and wet lab backgrounds, thereby providing an unusually interdisciplinary environment.
The Computational Biology Group seeks a highly-skilled Ph.D. student to work on an exciting project on reconstruction and analysis of an integrated gene regulatory network model to elucidate key mechanisms of cellular reprogramming. The model will rely on the integration and mining of diverse transcriptomics and epigenomics data of different cell types from the Central Nervous System. The Ph.D. student is expected to collaborate with other members of the CBG to develop a computational methodology aiming at designing, in-silico, cellular reprogramming events, with a focus on the nervous system. This project will be carried out in collaboration with Prof. Noel Buckleys lab at Kings College London.
Requirements of the ideal candidate:
Master degree in Bioinformatics, Computer Science, Biology or a related discipline
Prior experience in mathematical modelling of biological networks, especially in network inference and analysis
Excellent working knowledge in English.
.
We offer:
Full contract for Ph.D. student for three years with possibility of renewal
Opportunity to do applied research to medical problems within a highly dynamic research institution (LCSB) and in collaboration with internationally recognized partners
An exciting international environment
A very competitive salary

For further information, please contact:

Prof. Dr. Antonio del Sol
E-mail: antonio.delsol@uni.lu

Applications should contain the following documents:
A detailed curriculum vitae
cover letter mentioning the reference number
description of past research experience and future interests
name and addresses of three referees

All applications should be sent preferably in electronic version until December 31st, 2013 to the following address:

Luxembourg Centre for Systems Biomedicine (LCSB)
University of Luxembourg
7, avenue des Hauts-Fourneaux
L-4362 Esch-sur-Alzette
Tel: +352-466644-6982 (Office)
Email: antonio.delsol@uni.lu
http://www.lcsb.lu

Circular plots in R

Jit — Mon, 19 Jun 2017 06:20:27 -0500

Circular plots are useful to represent complicated informations. They are used in 2 specific cases: when you have long axis and numerous categories, and when you want to show relationships between elements. The circos gallery displays several examples of circular plots, what gives a nice overview of the possibilities. Circos is the most famous

tool to create circular plots. Thanks to Zuguang Gu, the Circlize library makes the circos functions available in R! It implements low-level graphic functions for adding common graphics in a circular layout. This page aims to learn you how to use the library, so I strongly advise to read the graphics in the proposed order!

http://www.r-graph-gallery.com/portfolio/circular-plot/

Address of the bookmark: http://www.r-graph-gallery.com/portfolio/circular-plot/

Research Fellow @ Mendel laboratory

Tue, 26 Nov 2013 00:07:57 -0600

IRCCS Casa Sollievo della Sofferenza – Mendel laboratory is seeking one talented bioinformatician (Rome)
Start date: immediate

Duration: 1 year

Funding Source: Institutional
Salary on grant: B2 (€ 22.000/year gross)
Contact Person (Referent): Tommaso Mazza
Ref. E-Mail: t.mazza@css-mendel.it
Tel: +39 06 44160526
Fax: +39 06 44160548

Job Description: The bioinformatics unit at IRCCS Casa Sollievo della Sofferenza - Mendel laboratory in Rome is looking for one young PhD bioinformatician with specific experience and/or interest in the analysis of transcriptomic data.

The candidate will be mainly in charge of developing research on a range of hot applications and projects, dealing with microarrays, RNA-Seq and miRNA-Seq data. Main activities will be: (i) data analysis (short-reads mapping, variants call and annotation, functional enrichment analysis of gene expression data); (ii) networks analysis and simulation (artificial knockout, redundancy and lethality analysis, gene set essentiality); (iii) developing of ad-hoc software solutions/routines on clusters of CPUs and GPUs.

The correct cultural background (training in Biology / Computer Science / Statistics or a mix of the three) and a strong interest in working with high throughput data analysis will be considered at the same level of specific experience in the above-mentioned fields.
Knowledge of molecular modeling and simulation and one of these languages: python, perl, R, Java, C++, C# is a golden plus. Good knowledge of Scientific English will be positively evaluated for this position, together with good presentation and teamwork skills.

A CV with one professional reference, details on educational background and of the biological and/or bioinformatic and/or data analysis skills and experience should be sent by email for a preliminary selection to: Tommaso Mazza, CSS-Mendel: t.mazza@css-mendel.it

Context
Casa Sollievo della Sofferenza is an Institute for hospitalization, care, and scientific research located in San Giovanni Rotondo, Italy. It integrates clinical assistance (with inpatient and outpatient facilities) and research. It has an affiliate institute, CSS-Mendel, located in Rome. Between the two sites, it employs over 100 researchers who focus on genetics. The Center is equipped with state of the art genomics technology (SOLiD 5500XL next generation sequencer, Illumina MiSeq, Affymetrix/Agilent microarray platforms, etc) as well as a dedicated high performance computing facility, a non-conventional workstation of GPUs and a short- and long-term storage disk.

Applications
Candidates should send:
• a cover letter explaining the role they would like to undertake within the Center, even if it is not listed in this job adv, stating clearly why they would be a good fit to the proposed role, and what they would bring to the Center in terms of expertise, ideas, talent;
• a CV including a list of publications;
• List of referees;

More at http://www.css-mendel.it/

MinION_GC: An R script to do some QC on MinION data

Radha Agarkar — Sun, 03 Dec 2017 15:19:18 -0600

Other tools focus on getting data out of the fastq or fast5 files, which is slow and computationally intensive. The benefit of this approach is that it works on a single, small, .txt summary file. So it's a lot quicker than most other things out there: it takes about a minute to analyse a 4GB flowcell on my laptop.

https://github.com/roblanf/minion_qc

Address of the bookmark: https://github.com/roblanf/minion_qc

Bioinformatics group at Boku University

Thu, 12 Dec 2013 17:53:10 -0600

The Bioinformatics group at Boku University has two main areas of interest, underpinning a common goal, the study of complex systems in living organisms. To overcome the engineered redundancies and combinatorial effects prevalent in higher eukaryotes, novel views augmenting the classical gene by gene approaches are required. We combine

1. Work to establish improved quantitative experimental assays (such as microarrays or differential in-gel electrophoresis) and
2. Development of modern computational methods (such as hierarchical probabilistic models or integration of heterogeneous data sources)

Lab page @ http://bioinf.boku.ac.at/

R 3.5.0 has been Released!

Jit — Thu, 26 Apr 2018 11:31:58 -0500

The latest version of R is a major release! It comes with a ton of new features, including performance and speed improvements
All R packages will now be byte-compiled, hence boosting packages installed from GitHub
You may need to re-install all previously installed R packages; old scripts however will continue to work normally

More at https://cran.r-project.org/doc/manuals/r-release/NEWS.html

Free math books

Manisha Mishra — Thu, 12 Dec 2013 19:38:34 -0600

Bioinformatics require some match skills, therefore I decided to provide this wonderful math eBooks links to the BOL community.

Please add ur links/bookmarks in comment section.

Address of the bookmark: http://physicsdatabase.com/free-math-books/

Making 2D Hilbert Curve

Jit — Mon, 17 Sep 2018 05:43:35 -0500

Hilbert curve is a type of space-filling curves that folds one dimensional axis into a two dimensional space, but still keeps the locality. It has advantages to visualize data with long axis in following two aspects:

greatly improve resolution of the visualization fron n to √nn;
easy to visualize clusters because generally data points in the axis will also be close in the 2D space.

This package aims to provide an easy and flexible way to visualize data through Hilbert curve. The implementation and example figures are based on following sources:

Address of the bookmark: https://bioconductor.org/packages/devel/bioc/vignettes/HilbertCurve/inst/doc/HilbertCurve.html

Bioinformatics software for biologists in the genomics era

Poonam Mahapatra — Sun, 22 Dec 2013 17:31:05 -0600

The genome sequencing revolution is approaching a landmark figure of 1000 completely sequenced genomes. Coupled with fast-declining, per-base sequencing costs, this influx of DNA sequence data has encouraged laboratory scientists to engage large datasets in comparative sequence analyses for making evolutionary, functional and translational inferences. However, the majority of the scientists at the forefront of experimental research are not bioinformaticians, so a gap exists between the user-friendly software needed and the scripting/programming infrastructure often employed for the analysis of large numbers of genes, long genomic segments and groups of sequences. We see an urgent need for the expansion of the fundamental paradigms under which biologist-friendly software tools are designed and developed to fulfill the needs of biologists to analyze large datasets by using sophisticated computational methods. We argue that the design principles need to be sensitive to the reality that comparatively small teams of biologists have historically developed some of the most popular biological software packages in molecular evolutionary analysis. Furthermore, biological intuitiveness and investigator empowerment need to take precedence over the current supposition that biologists should re-tool and become programmers when analyzing genome scale datasets.

Address of the bookmark: http://bioinformatics.oxfordjournals.org/content/23/14/1713.full