Selecting particular columns from large datasets (csv) using R Studio?

So I have large number of csv files (100+) in a directory with same structure and column names. The data is in time series and there are approx 30 columns/file. However i only want to aggregate...

08 February 2021 245 5 View

How much pre-PCR dilution of mixed-template DNA extracted from pollen (honey) is appropriate for Metabarcoding?

I'm working on pollen DNA metabarcoding to identify the floral composition of honey. How much pre-PCR dilution of mixed-template DNA extracted from pollen (honey) is appropriate for the...

28 December 2020 9,132 1 View

How to add two vertical and parallel Fresnel reflection coefficients to retrieve overall reflection coefficient for a right hand circular wave?

I have a problem in which a right hand circular polarized wave (GPS wave) encounters an ideal smooth plane obliquely, and then is reflected off that. To solve this kind of problems, the wave is...

28 December 2020 2,271 3 View

Which is better to focus on teaching or research for a good academic life and Why?

Which is better to focus on teaching or research for For a good academic life and Why?

26 December 2020 5,737 9 View

Is ag paste suitable for back contact on silicon wafer? or i should deposit al on the back surface using pvd or plasma sputtering?

Fabricating silicon solar cell

22 December 2020 4,906 7 View

Which renewable source is the best ?

wind hydro solar etc.

21 December 2020 6,360 16 View

Why is light pure energy?

light is pure because the light is the simplest electromagnetic construct but the energy of any object is also of the same kind.

20 December 2020 207 4 View

How to handle Missing Values for Skipped Questions (Systematic Missing) in R ?

10 December 2020 435 4 View

What is the best industrial emulsifier to make silicon oil in water emulsion?

I need to make long-lasting stable emulsions of 6 wt. % percent silicon oil in DI water. The previousely made emulsions using Tween and Span Emulsifiers did not remain stable after a week.

31 October 2020 3,568 3 View

Carbon Emission calculation factors ?

I am thinking about writing a paper on carbon emissions based on electricity consumption data from some buildings. From a research perspective, which factors should i specially focus while...

09 October 2020 4,142 3 View

How to determine characteristic eddy diameter from power spectrum density distribution?

I have acquired the power spectrum density from turbulent data (plotting [m^2 s^2 Hz^-1] over [Hz]), using welch's method and am trying to translate this to an approximate eddy diameter. This is...

26 November 2020 8,108 2 View

Psychological characteristics of a "novice swimming child" 5 years ?

What are the cognitive characteristics of a 5-year-old "novice swimming child", and everything related to motor learning, psychological and kinetic tests and measurements compatible with the study?

06 September 2020 9,327 2 View

Psychological characteristics of a "novice swimming child" 5 years ?

What are the cognitive characteristics of a "novice swimming child" 5 years old, all related to motor learning, psychological and kinetic tests and measurements that are compatible with the study

06 September 2020 258 2 View

Are there any good free fish swimming tracker software for mac?

I am trying to track multiple sheepshead minnows swimming behavior

14 June 2020 8,424 3 View

Daily habits to keep our brain from shrinking?

Our brains really do shrink as they age. But new research finds that regularly engaging in reading, swimming, gardening, or other activities could slow the process.

29 March 2020 9,049 95 View

What are some good recommendations for free software that could be used to quantify video data on juvenile fish behavior and swimming activity?

Ideally I would like to use free software that can be used with a Macintosh. My objective is to quantify individual swimming patterns from 2-dimensional video data. I would like to collect...

16 March 2020 7,635 3 View

Does benzocaine or euthanasia solution affect RNA extraction?

I want to do RNA extraction for zebrafish embryos/larvae at 2dpf, 5dpf and 7dpf. I'm using Trizol and I want to store the larvae in Trizol at -20 oC first before extraction at a later time....

31 December 2019 7,791 2 View

What's an effective calcium channel blocker for E.coli?

I would like to use a calcium channel blocker to prevent calcium entry in E.coli. The effect of the channel blocker will be observed on swimming agar plates after 12-18 hours growth period. Also,...

05 June 2019 6,843 2 View

Is salt to generate chlorine for swimming pools toxic?

I am trying to aquire recent research, that either confirms or disproves, that salt used to generate chlorine for swimming pools is more toxic to humans than standard clorine. Thanks! David

27 May 2019 8,034 3 View

Why diazepam and other standard were administered intraperitoneally (i.p), while extract were administered by orally using gavage?

Evaluation of neuropharmacological activity of plant extract using behavioral models like (EPM, Hole board, Hole cross, Forced swim and Tail suspension test) is it mandatory to use same route for...

24 May 2019 8,115 2 View