GC-MS
http://www.metabolon.com/
This site is to serve as my note-book and to effectively communicate with my students and collaborators. Every now and then, a blog may be of interest to other researchers or teachers. Views in this blog are my own. All rights of research results and findings on this blog are reserved. See also http://youtube.com/c/hongqin @hongqin
Monday, March 25, 2013
Saturday, March 23, 2013
Anaerobic growth of microbes (in progress)
Anaerobic growth of microbes
http://www.800ezmicro.com/products/anaerobic-hypoxic-systems/114-whitley-workstation-dg250.html
Wednesday, March 20, 2013
NGS services (in progress)
Beckman Coulter
Genomics, $899, based on a batch of 32 samples including library construction, 2x75bp sequencing on Illumina HiSeq 2000 and primary data analysis. This means 32x900 ~ 30K per order.
Friday, March 15, 2013
Probability of radioactive isotope survival and lifetime
Based on wikipedia, particle decays is a Poisson process. The probability that a particle survives for time t before decaying is the Poisson waiting time, i.e., an exponential distribution. This is amazingly similar to the coalescence simulation in population genetics.
Spelman international travel application link
For students to take international trips, please apply through this link:
Faculty should contact HR about approval, travel insurance, and polices about taking international trips.
Contact person is Dr. Dimeji Togunde
Faculty should contact HR about approval, travel insurance, and polices about taking international trips.
Notes on ZipfR
ZipfR is for Large Number of Rare Events (LNRE) modeling of lexical distributions. So its parameters are named related to the lexicon.
N = sample size.
V = vocabular size.
Number of types (Vm) per frequency class (m).
The question is how to specify gamma for the power-law network model?
ZipfR limits alpha in ZM model between 0 and 1, this seems to be a major problem for biology network simulation that often have power-law coefficient between 2 and 3.
Power law, Zipf, Pareto distribution, and gene network
Power law distribution refers to the general form of y = a * x^ k.
In gene interaction networks with infinite number of genes, the power law distribution of connectivity is
where k is the connectivity, and Z(gamma) is the Riemann zeta function. This definition implies that when gamma <=3, the mean does not exists because its distribution has a infinite variance.
Zipf law is defined in a finite population with N number of elements with discrete values.
Zipf law can be generalized as the Zipf–Mandelbrot law.
where k is the rank of data, and q and s are distribution parameters. This generalized Zipf-Mandelbrot law also covers the specialized form for a 'pure' gene/protein network in power-law configuration as in Eq 1.
In R, a package zipfR is available. See discussion http://pidgin.ucsd.edu/pipermail/r-lang/2007-July/000047.html and http://zipfr.r-forge.r-project.org/.
Pareto distribution is defined for continuous variable x. It is seemed to designed to describe the tail distribution in economics. It cumulative distribution function given by wikipedia is:
In gene interaction networks with infinite number of genes, the power law distribution of connectivity is
where k is the connectivity, and Z(gamma) is the Riemann zeta function. This definition implies that when gamma <=3, the mean does not exists because its distribution has a infinite variance.
Zipf law is defined in a finite population with N number of elements with discrete values.
The above is basically the probability mass function. In this form, the variance is always finite. So, the theoretic property is different from Eq 1 definition.
Zipf law can be generalized as the Zipf–Mandelbrot law.
where k is the rank of data, and q and s are distribution parameters. This generalized Zipf-Mandelbrot law also covers the specialized form for a 'pure' gene/protein network in power-law configuration as in Eq 1.
In R, a package zipfR is available. See discussion http://pidgin.ucsd.edu/pipermail/r-lang/2007-July/000047.html and http://zipfr.r-forge.r-project.org/.
library(zipfR)
Z <- lnre("zm", alpha=.8, B=1e-3)
hist( as.integer(rlnre(Z, 1000)))
As an alternative, the "rmutil" package by Jim Lindsey provides Pareto distributions.
It seems netmodels also provide power-law distribution, but this package become orphaned.
library(igraph)
data(test.net,package="netmodels")
dist <- degree(test.net)
alpha <- calc.alpha(dist)
dist.power.law(alpha,5)
Pareto distribution is defined for continuous variable x. It is seemed to designed to describe the tail distribution in economics. It cumulative distribution function given by wikipedia is:
Zipf distribution can be viewed as a discrete Pareto distribution. So, I can use 'rpareto{extremevalues}' or 'rpareto{VGAM}' to generate the randome number and then discretize them. (See http://tuvalu.santafe.edu/~aaronc/powerlaws/plfit.r).
Rich Wash wrote some R scripts to provide dpowerlaw(), ppowerlaw(), rpowerlaw() functions.
http://code.google.com/p/evaltools/source/browse/trunk/lib/powerlaw.r?spec=svn11&r=11
The igraph package provide a power-law fit function that seems to uses mle().
References and links:
http://tuvalu.santafe.edu/~aaronc/powerlaws
http://tuvalu.santafe.edu/~aaronc/powerlaws/plfit.r
http://code.google.com/p/evaltools/source/browse/trunk/lib/powerlaw.r?spec=svn11&r=11
Rich Wash wrote some R scripts to provide dpowerlaw(), ppowerlaw(), rpowerlaw() functions.
http://code.google.com/p/evaltools/source/browse/trunk/lib/powerlaw.r?spec=svn11&r=11
The igraph package provide a power-law fit function that seems to uses mle().
References and links:
http://tuvalu.santafe.edu/~aaronc/powerlaws
http://tuvalu.santafe.edu/~aaronc/powerlaws/plfit.r
http://code.google.com/p/evaltools/source/browse/trunk/lib/powerlaw.r?spec=svn11&r=11
Thursday, March 14, 2013
Notes on introduction to systems biology (in progress)
ODE models
Bifurcation
Cell cycle model
Modeling butanol production by Clostridium beijerinckii,
Shinto, H, Tashiro, Y. Yamashita, Kobayashi, ..., 2008, Kinetic study of substrate dependency for higher butanol production in acetone-butanol-ethanol-fermentation. Process Biochemistry, 43, 152-1461. (XppAuto ode model is included).
Notes on chemostat (in progress)
DASGIP DASbox
A mini bioreactor system.
Maitreya Dunham lab on chemostat
Botstein lab on chemostat
Botstein lab chemostat manual
Notes on microfluidics in biology (in progress)
http://www.microfluidicsystems.com/
Ruth Williams, sticky lithography, The Scientist.
Amber Dance, live-cell imaging system, The Scientist
Carl Zeiss Cell observer
http://ibidi.com/
Perfusion system
Perfusion pump, Bioptechs, ~$1.2K,
PDMS
pulse and change growth yeast media in microfluidics, such as radicicol
screen of pooled mutants and hybrids.
high throughput phenotyping (lifespan assays)
Candidate projects and data sources for course projects (in progress)
Bioquest
NCBI GEO data
The loan data from Coursea.org data analysis course:
http://cancergenome.nih.gov/
TCGA
linkedlifedata
data.gov
cancer genome atlas
http://cancergenome.nih.gov/
TCGA
https://github.com/tcga/tcga.github.com
http://imagejs.org/
Scientific survey data
http://bioquest.org/2013schedule/
NCBI GEO data
GEO includes gene expression, and NGS dataJohn Snow's cholera data
http://www.r-bloggers.com/john-snows-cholera-data-in-more-formats/
GHO Raw Data Download Web Service
http://datadryad.org/http://apps.who.int/gho/athena/
WHO childhood hunger data, used by Jeff Leek's course
http://datadryad.org/resource/doi:10.5061/dryad.jr4dc oxidative stress and mutation
The loan data from Coursea.org data analysis course:
For this analysis you will use the loans data available from here:
https://spark-public.s3.amazonaws.com/dataanalysis/loansData.csv
https://spark-public.s3.amazonaws.com/dataanalysis/loansData.rda
There is a code book for the variables in the data set available here:
https://spark-public.s3.amazonaws.com/dataanalysis/loansCodebook.pdf
http://cancergenome.nih.gov/
TCGA
linkedlifedata
data.gov
cancer genome atlas
http://cancergenome.nih.gov/
TCGA
https://github.com/tcga/tcga.github.com
http://imagejs.org/
Scientific survey data
Wednesday, March 6, 2013
Bacterial aging (in progress)
Draft in progress.
Francois Taddei
Dukan S, Nystrom T (1998) Bacterial senescence: stasis results in increased and differential oxidation of cytoplasmic proteins leading to developmental induction of the heat shock regulon. Genes Dev 12: 3431–3441.
Dukan S, Nystrom T (1999) Oxidative stress defense and deterioration of growth-arrested Escherichia coli cells. J Biol Chem 274: 26027-26032.
Francois Taddei
Asymmetric segregation of protein aggregates is associated with cellular aging and rejuvenation
Dukan S, Nystrom T (1998) Bacterial senescence: stasis results in increased and differential oxidation of cytoplasmic proteins leading to developmental induction of the heat shock regulon. Genes Dev 12: 3431–3441.
Dukan S, Nystrom T (1999) Oxidative stress defense and deterioration of growth-arrested Escherichia coli cells. J Biol Chem 274: 26027-26032.
Topics on food and/or health disparity (in progress)
Ron Finley: A guerilla gardenner, Ted Talk
"Food is the problem and the solution".
"Growing your food is like printing your money."
Type 2 diabetes declines along out-of-Africa.
http://ailun.stanford.edu/pdf/Diabetes.pdf
Hemoglobin
Prostate cancer
Monday, March 4, 2013
Radiation-dose survival curve of D. radiodurans is similar to Gompertz curve
Radiation-dose survival curve of D. radiodurans is similar to a Gompertz curve. It's broader shoulder suggests a very smaller 'initial mortality rate' scenario.
References:
Daly, M.J., 2012, DNA Repair, Death by protein damange in irradiated cells.
Protein carbonylation and aging (in progress)
Maisonneuve09 stated that "Carbonyl derivatives are mainly formed by direct metal-catalysed oxidation (MCO) attacks on the amino-acid side chains of proline, arginine, lysine and threonine residues. " Maisonneuve09 then focus on the RKPT-enriched regions in proteins.
More genomics methods have been applied to identify carbonylation sites.
Connection to ROS damage and aging? Do aging-hub aging tend to avoid carbonylation motif??
References
- Maisonneuve, E, et al, 2009 Plos ONE, Rules Governing Selective Protein Carbonylation
- AG Madian, FE Regnier - Journal of proteome research, 2010, Proteomic identication of carbonylated proteins and their oxidation sites.
- RC Bollineni, R Hoffmann, M Fedorova - Journal of proteomics, 2011, Identification of protein carbonylation sites by two-dimensional liquid chromatography in combination with MALDI-and ESI-MS.
- Nystrom, Thomas, 2005, Nature, Role of oxidative carbonylation in protein quality control and senescnece.
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Eq. 2 (wikipedia) 

