Displaying 20 results from an estimated 78 matches for "tissues".
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2005 Feb 10
5
sample
I am trying to sample a subset from a matrix using sample.
The size of the matrix is 20X 1532. It works fine with this,
but when I transpose the matrix and try to sample it, it returns
null.
pick.set<-sample(tissue.exp.t,5,replace=FALSE,prob=NULL)
Is there something that I am missing here ?
Thanks ../Murli
2008 Sep 14
2
Help please! How to code a mixed-model with 2 within-subject factors using lme or lmer?
Hello,
I'm using aov() to analyse changes in brain volume between males and
females. For every subject (there are 331 in total) I have 8 volume
measurements (4 different brain lobes and 2 different tissues
(grey/white matter)). The data looks like this:
Subject Sex Lobe Tissue Volume
subect1 1 F g 262374
subect1 1 F w 173758
subect1 1 O g 67155
subect1 1 O w 30067
subect1 1 P g 117981
subect1 1 P w 85441
subect1 1 T g 185241
subect1 1 T w 83183
subect2 1 F g 255309
subect2 1 F w 164335
subect2 1 O g...
2011 Sep 20
1
A question regarding random effects in 'aov' function
Hi,
I am doing an analysis to see if these is tissue specific effects on the
gene expression data .
Our data were collected from 6 different labs (batch effects). lab 1 has
tissue type 1 and tissue type 2, lab 2 has tissue 3, 4,5,6. The other labs
has one tissue type each. The 'sample' data is as below:
2007 Feb 14
1
nested model: lme, aov and LSMeans
I'm working with a nested model (mixed).
I have four factors: Patients, Tissue, sex, and tissue_stage.
Totally I have 10 patients, for each patient, there are 2 tissues
(Cancer vs. Normal).
I think Tissue and sex are fixed. Patient is nested in sex,Tissue is
nested in patient, and tissue_stage is nested in Tissue.
I tried aov and lme as the following,
> aov(gene ~ tissue + gender + patients%in%gender + stage%in%tissue
>lme(gene ~ tissue + gender, random...
2008 Sep 13
2
moving from aov() to lmer()
Hello,
I've used this command to analyse changes in brain volume:
mod1<-aov(Volume~Sex*Lobe*Tissue+Error(Subject/(Lobe*Tissue)),data.vslt)
I'm comparing males/females. For every subject I have 8 volume measurements
(4 different brain lobes and 2 different tissues (grey/white matter)).
As aov() provides only type I anovas, I would like to use lmer() with type
II, however, I have struggled to find the right syntaxis.
How should I write the model I use with aov() using lmer()??
Specifying Subject as a random effect is straightforward
mod2<-lmer(Volume~S...
2011 Oct 30
1
Normality tests on groups of rows in a data frame, grouped based on content in other columns
Dear R users,
I have a data frame in the form below, on which I would like to make normality tests on the values in the ExpressionLevel column.
> head(df)
ID Plant Tissue Gene ExpressionLevel
1 1 p1 t1 g1 366.53
2 2 p1 t1 g2 0.57
3 3 p1 t1 g3 11.81
4 4 p1 t2 g1 498.43
5 5 p1 t2 g2 2.14
6 6 p1 t2 g3 7.85
I
2004 Jan 22
0
problem fitting linear mixed models
Hello,
I'm fitting linear mixed models to gene-expression data from
microarrays, in a data set where 4608 genes are studied.
For a sample of 5 subjects and for each gene we observe the expression
level (Intensity) in four different tissues: N, Tp, Tx and M.
I want to test whether the expression level is different accross
tissues. Between-subject variability is modeled with a random intercept,
and the within-subject by allowing heteroscedastic and correlated errors
accross tissues. The proposed model can then be fitted by
lme(Inte...
2010 Nov 25
1
difficulty setting the random = argument to lme()
My small brain is having trouble getting to grips with lme()
I wonder if anyone can help me correctly set the random = argument
to lme() for this kind of setup with (I think) 9 variance/covariance
components ...
Study.1 Study.2 ...
Study.10
Treatment.A: subject: 1 2 3 4 5 6 etc. 28 29 30
Treatment.B: subject: 31
2010 Apr 23
2
Problem with parsing a dataset - help earnestly sought
Dear fellow R-help members,
I hope to seek your advice on how to parse/manage a dataset with hundreds of
columns. Two examples of these columns, 'cancer.problems', and
'neuro.problems' are depicted below. Essentially, I need to parse this into
a useful dataset, and unfortunately, I am not familiar with perl or any such
language.
data <- data.frame(id=c(1:10))
2007 Jun 05
1
Can I treat subject as fixed effect in linear model
Hi,
There are 20 subjects grouped by Gender, each subject has 2 tissues
(normal vs. cancer).
In fact, it is a 2-way anova (factors: Gender and tissue) with tissue
nested in subject. I've tried the following:
Model 1: lme(response ~ tissue*Gender, random = ~1|subject)
Model 2: response ~ tissue*Gender + subject
Model 3: response ~ tissue*Gender
It seems like Mod...
2004 Jul 21
2
RE: Comparison of correlation coefficients - Details
...ze" correlation coefficients from
different sample sets? Could an expression such as "corr * (1 - pval)"
be used for normalization? Maybe, it is not possible to normalize
correlation coefficients?
Would a barplot comparing the correlation coefficients between two
genes for different tissues be meaningful? (Alternatively, I have
tried to use (1-pval) to calculate the gray-level of the bars.)
Any further suggestions would be appreciated very much.
Best regards
Christian Stratowa
-----Original Message-----
From: Stratowa,Dr.,Christian FEX BIG-AT-V
Sent: Monday, July 19, 2004 15:00
T...
2011 Sep 15
1
Questions on 'lme' function, urgent!
Hi Dear all,
I have some gene expression data samples from different tissue types
-----------------------------------------------
- 120 samples from blood (B)
- 20 samples from Liver (L)
- 15 samples from Kidney (K)
- 6 samples from heart (H)
-----------------------------------------------
All the samples are from different individuals, so there are in total 161
individuals from which the DNA was
2010 Nov 02
2
multi-level cox ph with time-dependent covariates
...marker measurements
(and hundreds of covariates) at different time points from different
tissue samples of different patients. Suppose that the data were
coming from animal model with very few subjects (n=6) that were
followed up given a pathogen exposure, measured several times,
sampling different tissues in the same days, until a certain outcome
was reached (or outcome censored). Suppose that the pathogen can vary
over time (might be a bacteria that selects for drug-resistance) and
that also it can vary across different tissue reservoirs within the
same patient.
In other words: names(data) = patie...
2009 Oct 15
0
Setting random effects within a category using nlme
...r each
Type/Tissue combination. Nevertheless, I *think* this is doing what I want.
Given my limited stats training, I also like the fact that the Corr b/w aL and
aN is very low.
Moving on, the second model I would like to fit assumes that the population of
aN and aL values across the set of Tissues differ between Types. I have tried
a number of different syntaxes, but I can't seem to get the output I was
expecting. For example, if I run
------------------------------------------
> model2 = nlme(Count ~ quad.PBMC.model(aL, aN, T0),
+ data = tissueData,
+ start = list( fixe...
2004 Jul 22
0
RE: Comparison of correlation coefficients - Details
...efficients from different
> sample sets? Could an expression such as "corr * (1 - pval)" be used
> for normalization? Maybe, it is not possible to normalize correlation
> coefficients? Would a barplot comparing the correlation coefficients
> between two genes for different tissues be meaningful? (Alternatively,
> I have tried to use (1-pval) to calculate the gray-level of the bars.)
>
> Any further suggestions would be appreciated very much.
>
> Best regards
> Christian Stratowa
>
> -----Original Message-----
> From: Stratowa,Dr.,Christian FEX BIG...
2007 Nov 13
1
Cleaning database: grep()? apply()?
Dear R users,
I have a huge database and I need to adjust it somewhat.
Here is a very little cut out from database:
CODE NAME DATE DATA1
4813 ADVANCED TELECOM 1987 0.013
3845 ADVANCED THERAPEUTIC SYS LTD 1987 10.1
3845 ADVANCED THERAPEUTIC SYS LTD 1989 2.463
3845 ADVANCED THERAPEUTIC SYS LTD 1988 1.563
2836 ADVANCED TISSUE
2008 Jul 14
1
Tissue specific genes by ANOVA?
Hello,
unfortunately I have I big problem I can't solve.
I have to analyse if a gene is tissue specific. For example for the gene xyz
I have following expression values:
Heart Liver Brain
8.998497 10.013561 12.277407
9.743556 10.137574 11.033957
For every tissue I have two values from two different experiments.
Now I want to test if Heart is significant higher
2008 Feb 21
3
variable syntax problem
dear members,
i would like to write a variable in a plot title (main="") but i don't
know the right syntax:(...i tried a lot of different ways without success.
here my example:
y=30
z=33
for (i in 10:length(tissue)) {
png(filename = tissues[i], width = 1024, height = 768, pointsize = 12,
bg = "white")
gene.graph("ENSG00000115252", rma.affy, gps=list(1:3, y:z),
type="mean-int", gp.col=c("red", "blue"), by.order=TRUE,
scale.to.gene=FALSE, use.symbol=TRUE, use.mt=FALSE, *main="PDE...
2011 May 20
1
How to do covariate adjustment in R
Hi, I have a question about how to do covariate adjustment.
I have two sets of 'gene expression' data. They are from two different
tissue types, 'liver' and 'brain', respectively.
The purpose of my analysis is to compare the pattern of the whole genome
'gene expression' between the two tissue types.
I have 'age' and 'sex' as covariates. Since
2006 Dec 07
6
Response To Form Submission Hanging
Hello,
I am using Mechanize to post a form to a website. When I do this by
hand in my browser the response takes about 35s to come back (it''s a
long page full of tables and graphics). When I do this with
Mechanize, the server starts to respond and then appears to hang.
The obvious conclusion is that my code is wrong but I am reasonably
sure that I haven''t altered it