What are the evolutionary origins of the vitamin B12 molecule?

More Derek Townshend's questions See All

Why are my barium titanate sputtered thin films rapidly changing color when I take them out of the chamber?

Hello, I have been attempting to grow barium titanate thin films with sputtering by using 99.95% pure separate Barium and Titanium targets and varying oxygen flow rates to my sputtering chamber....

16 July 2020 9,297 4 View

How does sublimation temperature change in Ultra-High Vacuum?

We have a molecule that we are thinking of annealing/depositing onto a substrate in ultra-high vacuum (UHV). From our past experience, we know that the molecule sublimates around 90C at 10mtorr....

16 July 2019 1,784 4 View

What is the role of IL-4 in generation of BM-DCs?

I see protocols for generation of mouse bone marrow derived macrophages generated with just GM-CSF or GM-CSF plus IL-4. Can someone tell me what role the added IL-4 plays in generation of these cells?

13 April 2019 3,255 2 View

Why is value of my blank higher than value of my samples in UV vis spectroscopy?

I am trying to plot a graph with R^2 > 0.8 with increasing values of Cadmium chelate from 0,2,4,6,8,10 mg/l . According to a paper I have read Cadmium-Alizarin Chelate is used in this method so...

16 February 2019 2,410 3 View

I have Cadmium +2 ions in a solution, What possible compounds can I add to this solution to make UV spectroscopy so as to find how much Cd +2 absorbs?

According to my teacher and research papers I have come to understand that UV spectroscopy requires Cadmium to be in a Chelating compound or a larger compound . What possible compounds can I add...

24 January 2019 4,711 2 View

Help Calculating Sample Size for Sickle Cell Disease Screening?

The current reported disease prevalence is .6% of the population. I've tried using the formula n=Z^2(p(1-p))/M^2 with a confidence level of 95% and M=0.05 but my n value is obviously too small if...

15 May 2018 5,253 3 View

Should I look at BCL-2 in whole cell or subcellular fraction?

I'm looking at BCL-2 in cultured cells. I'm comparing treatments that appear to inhibit apoptosis. I'd like to look at BCL-2 levels in whole cell lysates, but I'm wondering if I should be looking...

06 November 2017 5,424 3 View

Is there a specific statistical package(s) that would be best to run a longitudinal linear regression?

I am interesting in running a longitudinal linear regression and am wondering if there is anyone that has experience in this technique, and namely, if anyone can direct me to statistical packages...

06 August 2017 1,088 6 View

Does anyone have difficulty distinguishing BK viral cytopathic changes versus atypical urothelial cells in degenerated specimens?

This question pertains to urinary cytology specimens when screening for high grade urothelial carcinoma.

28 July 2015 4,684 2 View

How can I establish good 4T1 tumors in-vivo?

I'm growing 4T1 cells in mice. I'm implanting two contralateral tumors per mouse. I'm having a hard time getting the tumors to grow symmetrically. I understand they won't all be perfect, but I'm...

04 June 2015 9,106 6 View

MD MOE RMSD

How to calculate the RMSD values for a MD simulation using MOE?

07 August 2021 0 0 View

MD MOE RMSD

How to calculate the RMSD values for a MD simulation using MOE?

07 August 2021 0 0 View

fatal error

When I tried to energy minimization my system, I got fatal error as below. Fatal error: Atomtype opls_116 not found Although I've already added this line: ; include water #include "oplsaa.ff/spc.itp" to [molecultype] directive in my topology.

16 June 2021 0 0 View

fatal error

16 June 2021 0 0 View

fatal error

16 June 2021 0 0 View

fatal error

16 June 2021 0 0 View

What kind of fluid could I use for a pitfall trap that also does not invalidate molecular testing?

Hi, I want to start testing pitfall trap to obtain ants samples, but I need to conduct molecular analysis on those insects. So, what kind of fluid can I use? Ethanol expires too early and I need...

03 March 2021 5,978 5 View

Is there any test to determine the cardiovascular risk of patients with obesity? from the perspective of obesity?

We found tests to determine cardiovascular risk taking into account lipid profile, blood pressure, age, history of diabetes, other laboratories. But when weight is involved, there is a paradox. I...

02 March 2021 6,036 1 View

How to repeat an operation on an atom selection for multiple times in PyMol?

Hi, I am trying to construct a multi-layer fibril structure from a single layer in PyMol by translating the layer along the fibril axis. For now, I am able to use the Translate command in PyMol...

02 March 2021 4,569 4 View

New Journal, "Integrative Psychological and Behavioral Science" -- do you not know, and have you not seen, this done before?

Question to you and THEM, the New Journal, "Integrative Psychological and Behavioral Science" -- do you not know, and have you not seen, this done before? There appears to be a core problem for...

02 March 2021 3,024 2 View

Scott Ferrenberg

Not sure if this article is answering your question, but it describes the independent evolution, and likely selective driver of B12 synthesis in microbial taxa.

http://mbe.oxfordjournals.org/content/28/10/2921.full

Derek Townshend

Thanks Scott. That is exactly the type of background information I am looking for.