Bioinformatics connects life sciences and quantitative sciences, typically involving the application of software and algorithms to solve computationally intensive questions, such as those in genomics, sequence analysis, and systems biology. Questions tagged Bioinformatics should have a direct ...

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73 views

Software to calculate Fst from sequence data

I'm looking for a software to calculate Fst from 3 loci DNA data of individuals from a metapopulation. I don't have any prior on the population structure (have no idea of the number of subpopulations ...
2
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1answer
37 views

Quantitative Comparisons of Phylogenetic trees

I am working on a broad phylogenomic analysis of proteins involved in one particular cellular process. I have constructed a phylogenetic tree for each protein. I am now working on comparing those ...
4
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1answer
63 views

Blosum matrix with probabilities instead of the positive and negative scores

I am trying to find a version of the BLOSUM matrix that has the frequencies instead of the scaled log-odds. i.e. instead of the common version that tells us that the score LEU/ASP is -4, I would like ...
3
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1answer
57 views

Should the sum of RPKMs be constant over experiments

I have cufflinks data from 18 different RNA-seq experiments. I've noticed that if the sum all the RPKM values for a particular experiment, are vastly different between experiments. How could this be? ...
2
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0answers
29 views

dbSNP database table desciptions

I am trying to build a local implementation of dbSNP. I would like to know the descriptions of tables listed on ftp://ftp.ncbi.nlm.nih.gov/snp/database/organism_data/human_9606 and on ...
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0answers
24 views

What percentage of chimeric takes up in a cDNA library?

I get a cDNA library of species of Mollusca,and complete some of the clones with polyA tails.But when I translate them with three frames,I find there is a large percentage of sequences that cannot ...
3
votes
1answer
60 views

Local storage of NCBI database in MongoDB [closed]

My short term goal in a project is to build a local database of the NCBI dbSNP database. The data and schema are available on the FTP site(). I was going to implement the database using MySQL, but I ...
3
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1answer
44 views

Regarding the NCBI FTP site

I am trying to extract information about SNP data from the FTP server of NCBI. Could someone please explain to me how the directory is organised? There are many many files and folders and I can't ...
5
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3answers
171 views

Protein structures given in PDB and SNP's

There are millions of proteins given in PDB, the sequence for which we can download in FASTA format. There are also hundreds of SNP's given in NCBI dbSNP. My question is whether the proteins in PDB ...
3
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1answer
36 views

I2D vs STRING for protein-protein interactions

Can someone clearly explain me the differences between STRING and I2D(Interlogous interaction database) ? What does each database do best ? Which database is better for what kinds of studies etc ?
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1answer
31 views

Alleles notation in SNPPedia criteria

I can understand the allele notation when is in the form rs8176719(T;T) or rs8176719(G) but recently i found this ones rs8176719(T;-) or rs8176719(-;T). So im confused, rs8176719(T;-) is the same as ...
2
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1answer
39 views

What do the Clustal Alignment Symbols Mean?

Occasionally I will run protein alignments on peptide families and I can never remember what the symbols mean to show degrees of identity. What do they mean?
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1answer
20 views

Why are different lengths of nucleotides taken for structure prediction from an miRNA match area after BLAST analysis?

Generally in miRNA prediction most researchers do as Blast search with a set of miRNAs downloaded from miRBase with the parameters they require. Later on usually custom methods are utilized to get an ...
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0answers
36 views

Meta-Data Retrieval from Bio-Rad Images

I asked a related question on SO, but I also had some biology related questions to this issue. One of the big things I'd like to do is sort between DNA/UV images and Western/Chemi images. After ...
1
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1answer
61 views

downloading a reference genome for alignment

I am currently working through the code example on the MATLAB website. It requires me to download the reference genome of Arabidopsis thaliana (thale cress) so I can use BowTie2 to align the Chip-Seq ...
5
votes
5answers
137 views

What are some examples of evolving networks in biology?

I'm a master student working on networks analysis in general. A network is something that has nodes and there are links between the nodes. Nodes and links could have attributes. An evolving network is ...
3
votes
1answer
134 views

The parameter for setting the number of mismatches in standalone blast

In a standalone blast search, is there a parameter that could be specified to fix the number of mismatches allowed in an alignment. I went through the parameters and I could only find parameters to ...
2
votes
1answer
64 views

Steps to confirm if predicted miRNA is good or bad

I aligned all miRNAs available to the supercontigs of a particular genome with certain parameters (e value of 0.01 and a word match of atleast 7 as suggested in this paper). I have also isolated the ...
3
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1answer
58 views

mFOLD prediction result interpretation

I am trying to predict the secondary structure of certain predicted pre-miRNAs through mFOLD which is the generally accepted technique for structure prediction in most studies. I am finding it hard to ...
0
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0answers
30 views

What is the suitable terminology to describe this study approach?

I need to know the correct term(s) which are usually used in the parlance of both biology and bioinformatics for this study approach: About 11 transcripts were investigated using qPCR for a number of ...
1
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1answer
42 views

About the quality of microsatellites

I built a script to detect microsatellites in a FASTA file. However, there are thousands of possibilities. So, my question is: what are the markers of a "good" or "useful" microsatellite? - How ...
2
votes
1answer
48 views

Converting Ensembl Compara gene tree DNA alignment to corresponding amino acid alignment

I have Ensembl compara gene tree alignments (Compara.gene_trees.57.fasta.gz downloaded from ftp://ftp.ensembl.org/pub/release-57/emf/ensembl-compara/homologies/) in nucleotide format. According to ...
2
votes
1answer
41 views

H O N C alternatives for organic life?

Most organic structures built from hydrogen, oxygen, nitrogen and carbon. They are represent 1-,2-,3-,4- bond relations (chemical valence) which allow to build variety of chain structures. Are there ...
1
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1answer
47 views

What is the close and related genome used for in Gene models?

all I am a little bit confused about using the related genome or reference genome. When we have a reference genome, we can do alignment. Also we can do the assembly. Can you give some more reason ...
0
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1answer
85 views

Color van der waals bonds in swiss PdbViewer

I'm trying to color certain amino acid's van der waals bonds as in the following picture: can anybody please describe the steps to accomplish that?
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2answers
80 views

Gene perturbation, what is it used for, explain to computer scientists? [closed]

I am trying to build a gene regulation network, and I need some basic knowledge of it. So, in gene research, we perturb genes. Such as knock down them? Can people tell 2 or 3 experiment methods to ...
5
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1answer
79 views

Base Substitution Probabilities Derivation

In Felsenstein's 1981 Paper Evolutionary Trees from DNA Sequences: A Maximum Likelihood Approach, he describes (in equations (6) and (7)) a derivation of the equation of the probability of a ...
2
votes
1answer
52 views

Comparing Shine Dalgarno scores, creating a distribution

I am in the process of creating a poster for the phage that I recently annotated. The phage is an A4 and the portion of the poster I am working on is analyzing the data that we have collected. I have ...
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0answers
43 views

Infering the statistical tests performed in a paper [closed]

I am in great need of help in order to infer the statistical hypothesis tests performed in this paper (Xanthelasmata, arcus corneae, and ischaemic vascular disease and death in general population: ...
0
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1answer
56 views

Needing help in order to infer the statistical hypothesis tests performed in an old paper

I am in great need of help in order to infer the statistical hypothesis tests performed in an old paper. However I need to make some reasonable guesses only from the abstract of the paper since the ...
1
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2answers
110 views

Draw simplified phylogenetic tree for kids

I need to draw simple, phylogenetic tree for kids lecture. I am looking for an online tool where I can enter organisms (e.g., human, wasp, fungus) and get figure of a phylogenetic tree. Tree should ...
0
votes
1answer
54 views

Can someone suggest me good opencourseware links for learning computational biology basics?

My internet is slow and I have only 1GB data usage allowed for this month. And I want to make maximum out of it for learning some basics of computational biology. Which are the best online course ...
0
votes
2answers
112 views

How do download a list of the gene length of all genes?

I would like to get the gene length information of all the human genes. Is there a quick way to get this information? Thank you!
1
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2answers
112 views

What is most simple eukaryotic genome?

Expressed in number of Base Pairs or Bytes, about how large is the simplest eukaryotic genome? How much of this is 'junk-DNA' (non-coding)?
2
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1answer
92 views

Biological meaning/interpretation of clustering coefficience

I have been looking for some time to find an answer to the following question. I would be grateful for any help/advice or directions. I work very frequently with large number of proteins and assess ...
4
votes
3answers
81 views

Does anyone know a good software for producing tanglegrams?

I'm trying to look at relationships between parasite and host phylogenetic trees. I have done a bit of searching for a software in which to do this with, and I have tried using Dendroscope and ...
2
votes
2answers
80 views

chimeric sequences [closed]

I understand that chimeric sequence identification is done in results of sequencing projects to remove them and improve the quality of the output. I am unsure as to how they show up during sequencing. ...
2
votes
2answers
77 views

Sequence alignment scoring

The following table is from Deonier's text Computational Gene Analysis at p. 152. This is an exercise in global sequence alignment and scoring of alternative sequences. The text proposed a solution ...
0
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1answer
22 views

How do I share a protocol on Synbiota? [closed]

After I create a protocol on Synbiota, how can I share it with colleagues not in my project?
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2answers
49 views

Which types of hydrogen bonds are known to exist in RNA secondary structures?

I'm programming an implementation of an algorithm for pattern matching in RNA structures. The algorithm assumes the following types of base pairs: Plain: No base pairs (just the primary structure of ...
0
votes
0answers
26 views

Degenerate primer design for DIG in situ hybridization

New to molecular and have learned to design primers from google/youtube so any info would help Would someone be willing to share their protocol for degenerate primer design? Breakdown: Trying to ...
0
votes
2answers
51 views

is there a way to do batch download for all gene pathways?

I would like to download all the gene pathways and genes of each pathway. Preferably, gene length of each gene as well. It would be a lot more convenient if there is an R package.
0
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0answers
51 views

Width of vein in finger

I am working on my bachelors thesis, where one part of it is to find width of vein in fingertip. I use database images and extract vein patterns from it, but i have to calculate the width of vein and ...
5
votes
2answers
137 views

introduction to Chip Seq

I hope this question is suitable for this site. I am concerned about the Chip experiment part so I think it should be okay. I am a Applied Math student starting to get into bioinformatics and so I've ...
7
votes
1answer
177 views

List of np-hard problems in biology/bioinformatics

I'm not sure if this is the right place for this but... I am looking for a list of computationally "hard" problems such that if a problem from this list could be solved effectively, it would be ...
1
vote
2answers
230 views

TCGA gene expression data are missing matched normal

I'm trying to use the TCGA data portal to get gene expression data for cancer tissues, but I'm not sure what "Tumor matched normal" means. It is unclear to me if the values are already compared to a ...
3
votes
1answer
64 views

Book suggestion on computational molecular evolution

I'm currently reading Computational Molecular Evolution by Yang. Can you recommend alternatives to this book? I am finding it to be lacking on conceptual discussion (it's more focussed on the ...
2
votes
1answer
42 views

Number of autoregulation and FFL motifs in a network

Suppose we have a network with N* nodes (N* is the number of internal nodes). Every directed link in this network exists with probability p. What would be the number of: motifs that are ...
3
votes
1answer
53 views

relative-rate of evolution

I am supposed to calculate the relative rate of evolution of two sequences (human and sheep) with a chicken serving as the outgroup. The sequences are pretty long, so I will just create a short ...
4
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0answers
103 views

Comment on the introduction to a bioinformatics paper

I've written a paper about DNA sequence analysis. This paper attempts to use Bayesian modelling for a set of DNA sequences. It will probably end up either in a statistics journal, or, more likely, in ...