Why (111) peak of ZeoliteX changes depending on dry or wet?

09 February 2021 6,307 3 View

What's the best way to measure growth rates in House sparrow chicks from day 2 to day 10?

What's the best way to measure growth rates in House sparrow chicks from day 2 to day 10? Since, the growth curve from day 2 to 10 won't be like the "Logistic curve" it might not follow logistic...

03 March 2021 1,401 3 View

Standard curve shifting over time. How do I stabilise the ELISA?

24 February 2021 1,365 3 View

How does the injection volume impact LLOQ and ULOQ in regression analysis (LC-MSMS)?

Hello, I have run into an issue that has sparkled a debate at work: is the LLOQ/ULOQ impacted by injection volume under the following circumstances: 1) Same dilution factor of all samples 2)...

23 February 2021 9,159 3 View

Using the Pfaffl method: Is it possible that the ratio of the calibrator does not equal 1?

Hi all, I have a question regarding calculations using the Pfaffl method. I have 3 groups per experiment: 1 control group (calibrator) and 2 treatment groups with 6 to 7 biological repeats per...

19 February 2021 8,351 2 View

Is an issue for serial correlation when it is not found with the xtreg, fe on its lag ,but the lag become significant when you've vce(robust) std. er?

Dear Sir/Madam I have a dateset that suffers from heteroskedasticity and serial correlation. To address the serial correlation lag my variables of the fixed effect regression. I retrieve the...

15 February 2021 3,700 1 View

How to estimate/know plant virus concentration to make a standard curve in ELISA after serial dilution?

Hello, I am trying to know tomato virus titer/concentration in samples and I will perform serial dilution of the positive control. I wanted to ask How to estimate/know plant virus concentration to...

13 February 2021 6,534 4 View

How to best represent qPCR DD Ct or D Ct as a box plot?

I've been reading up on how to best represent qPCR data, specially on answers given on this site by Dr. Jochen Wilhelm. I understand box plots are the way to go, but I still don't understand them...

11 February 2021 7,228 3 View

XRPD Quantification - Building a calibration curve of drug excipient?

I am aiming to utilise XRPD to quantify a drug excipient within a drug product and have been having a little trouble building the calibration curve to allow for this quantification up until this...

10 February 2021 6,145 3 View

Gain and offset values in Sentinel-2 L1C?

Hello everyone. I have been trying to apply radiometric calibration on Sentinel-2 L1C images (bands 2,3,4 and 8), but every time after layerstacking I come across this error: "Calibration...

28 January 2021 7,160 1 View

How do I keep duplicates based on specific variable in STATA?

Hello everybody. Im new to STATA and this forum but I hope you can help me. I am doing a research project where I intend to estimate the prevalence of venous thromboembolic events (vte) up to 30...

24 January 2021 665 5 View