Compare to prevalence before and after covid in population studies?

Dear researchers, I have a prevalence of some diet habit in relatively large narrow population of children 13 years old in 2019 and 2020. Logically they are different population. However, since...

10 January 2021 3,170 9 View

Online self reported survey on nutrition and physical activities of children aged 11-12 years old?

Do you have some recommendation for this this type of survey? Some standard form of survey? I am looking for some short form, that can be easily done by children.

25 July 2020 2,641 3 View

GINI fractional regression and log transformation?

I would like to estimate changes in GINI during 15 years. Should I make log transformation of independet varible? Raw data for some independent varibles are not normaly distributed. Sincerely, A.

23 March 2020 1,601 3 View

Relativity of simultaneity and free fall: Do all observers see that two objects reach the surface at the same time when they are dropped?

Hi there, my question concerns a situation in which the law of free fall and the relativity of simultaneity come into play simultaneously. The general assumptions are as follows: 1. if we let...

03 February 2020 7,392 29 View

Bootstraping DEA scores and SE?

Dear all, I try to do a research based of DEA using bootsraping techniques in R packages: Bootstraping and DEAr. Does someone know how to calculate SE with 95%CI and how to obraine summaried...

24 October 2019 6,353 3 View

GINI coefficient EXCEL/R/SPSS?

Dear colleagues, do you have some EXCEL template for calculate GINI coefficient and create Lorenzo curve? I find some R packages but I am not sure how to use it on my date with population and...

12 April 2019 5,293 2 View

What secretes/produces the cytokine IL4?

Hello, I'm little confused about the secretion of IL4. In some papers it is mentioned that B cells secrete IL4, on other that it is Th cells, or even basophils. Can you also provide me with...

13 August 2018 9,329 3 View

Plants as Methane Producers? What is the latest standard of knowledge?

Dear All, not only in all known to me textbooks, but also in my academic environment, plants are only discussed as carbon sinks and therefore planting forests is said to be one of the main...

08 November 2017 6,587 7 View

Does Occam's razor favor MACHOs as candidates for Dark Matter?

Dear All, not only in our university, but almost in all well known to me lectures about Dark Matter, MACHOs (Massive Astrophysical Compact Halo Objects) are rather incidentally discussed while...

25 October 2017 9,570 2 View

Radnom sample froms survey data?

Using survey data, I planed to make log regression. Original sample size is 2000 and there are obaut 10% cases with outcome and 90% withoit it. May I chose amongst thant 90% random sample matced...

19 September 2017 3,296 1 View

How to normalise data on OPM package from R Studio ?

Good afternoon, I recently used OmniLog from BIOLOG for my experimentations : I tested the metabolism of different strains on 2 types of plates. I have 16 strains of 3 different groups...

02 March 2021 3,584 1 View

How to plot the probability paper of Gumbel distribution using R programing?

In R-studio, there are many commands of Gumbel package. Arguments are also different. I`m asking about the alpha parameter of the Copula which must be greater than 1. If this is the one used to...

25 February 2021 5,229 3 View

Has anyone had luck using cell lines other than HEK 293 (such as COS1) to package lentivirus?

I am looking to package lentivirus in endothelial cells but I am opposed to using 293 cells due to personal ethics regarding the source. I have done some reading and saw that COS1, COS7, & CHO...

25 February 2021 3,030 1 View

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25 February 2021 5,713 1 View

Is anyone working on a project focused on immigrants/newcomers working in the hospitality industry and how they have been impacted by COVID?

The on-going Covid-19 pandemic has had devastating economic effects on many industries. However, few have suffered to the same extent as full-service restaurants. Numerous studies have shown that...

24 February 2021 9,496 4 View

Implementation of chance-constrained optimization problem via scenario approach?

23 February 2021 7,826 2 View

What is the optimum time and temperature of blanching and pre-frying potato for frozen fries?

I am helping a local home industry for developing frozen fries from their local farm. I want to know what is the optimum blanching and pre-frying temperature and time for processing. Please also...

23 February 2021 1,616 5 View

Fictitious Boundary Meshing Method (FBM) in Commercial FEA software?

Is it possible to implement FBM in a commercial FEA software package, such as FEMLAB, COMSOL, or open source software like Moose?

22 February 2021 2,968 1 View

Are there packages (R or Python) for simple models (bucket?) to assess soil water content?

Hi everyone. I am researching droguht effects on soil water drought. I am looking for already implemented functions in R or Python to estimate soil water content from precipitation,...

21 February 2021 2,084 1 View

How reliable are degrees of freedom for lme mixed models in nmle package?

I am running mixed models analyses because I have participants nested in groups. Across the different analyses, I have very different degrees of freedom in the lme output with nlme package (and...

09 February 2021 6,767 3 View