search for: lc50

I am attempting to estimate LC50 (analogous to LD50, but uses exposure concentration rather than dose) by fitting a Weibull model; but I can't seem to get it to work. From what I can gather, I should be using survreg() from the survival package. The survreg() function relies on time-to-event data; my data result from 96 h ex...

Dear All: good morning I need helps with the calculation of the *LC50* from the data below x<-c(0,0.3,0.7,1,4,10) y<-c(100,86,65,51.3,19.2,7.4) yxreg<-lm(y~x) any help will be highly appreciated. with many thanks abou ______________________ *AbouEl-Makarim Aboueissa, PhD* *Professor of Statistics* *Department of Mathematics and Statistics* *Unive...

Hello, I used the glm function in R to fit a dose-response relationship and then have been using dose.p to calculate the LC50, however I would like to calculate the NOEL (no observed effect level), ie the lowest dose above which responses start occurring. Does anyone know how to do this? [[alternative HTML version deleted]]

Classification: UNCLASSIFIED Caveats: NONE A similar question has been posted in the past but never answered. My question is this: for probit analysis, how do you program a 95% confidence interval for the LD50 (or LC50, ec50, etc.), including a heterogeneity factor as written about in "Probit Analysis" by Finney(1971)? The heterogeneity factor comes into play through the chi-squared test for homogeneity and is equal to h=chi^2/(k-2), where k is the number of doses and k-2 are the degrees of freedom. I...

...gt; > >>> > >>> > On Mon, 2 Apr 2012 14:45:06 -0800, Danielle Duncan wrote >>> > > Hello, I used the glm function in R to fit a dose-response >>> relationship >>> > and >>> > > then have been using dose.p to calculate the LC50, however I would >>> like >>> > to >>> > > calculate the NOEL (no observed effect level), ie the lowest dose >>> above >>> > > which responses start occurring. Does anyone know how to do this? >>> > > >>> > >...

i wanna add left menu in the http://demo.projectfedena.org/ login:admin password:admin123 as there is no left menu in that i thought of adding a left menu. can any one tell how to do that with ROR. -- You received this message because you are subscribed to the Google Groups "Ruby on Rails: Talk" group. To post to this group, send email to

...008.nae.ds.army.mil> Content-Type: text/plain; charset="us-ascii" Classification: UNCLASSIFIED Caveats: NONE A similar question has been posted in the past but never answered. My question is this: for probit analysis, how do you program a 95% confidence interval for the LD50 (or LC50, ec50, etc.), including a heterogeneity factor as written about in "Probit Analysis" by Finney(1971)? The heterogeneity factor comes into play through the chi-squared test for homogeneity and is equal to h=chi^2/(k-2), where k is the number of doses and k-2 are the degrees of freedom. I...