Q&A

ResearchGate Q&A lets scientists and researchers exchange questions and answers relating to their research expertise, including areas such as techniques and methodologies.

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  • Krishnan Umachandran added an answer in SPSS:
    Do you use any software to teach statistics?

    There are arguments that we should teach statistics, not only using manual calculation but also by using software such as spss,minitab,stats and etc. Most of teacher or lecture prefered to use manual calculation. What is your expert opinion on this?

    Krishnan Umachandran · Nelcast Ltd.,

    Many of my students in Personnel Management and Industrial relations have forgotten statistical formulas, as the blindly load the data and get results through SPSS package. It is my personnel opinion that SPSS package use in academic projects upto Masters should be avoided as it make students to take easy way of getting results without going through the rationale and calculations of the statistics.

  • Yuan-Yeu Yau added an answer in Primer Design:
    Primer designing.

    I am designing primer for xylose reductase and xylitol dehydrogenase gene. Can anyone suggest me what parameters should be their in primer designing.
    If anybody having protocol please provide me. 

    Yuan-Yeu Yau · Northeastern State University

    @ Mahboubeh,

    Maybe I am not aware of it, but why we need at least one C or G at the 3' end of the primers? Just curious. Thanks.

  • Eliningaya Kweka added an answer in Mosquitoes:
    Who can provide a simple method of extracting pesticides from mosquito larvae?

    the assumption is that mosquito larvae reside in water which may be contaminated with water from farms where theres a lot of agricultural activities.

    Eliningaya Kweka · Tropical Pesticides Research Institute

    The best option is to know that, Larvae are living in water and they pick up residues from water and soil in their habiats. The best practice is to get soil and habitat water pesticides residues. I guess i have responded

  • Manjunath K N asked a question in Sigmoid Colon:
    How colon distension gradings are classified in abdominal CT images?

    Dear friends,

    In abdominal CT images, the distension of large intestine is classified in G0 (completely collapsed), G1 (partial collapse), G2 (sub optimal distension) and G3 (optimally distended). I want to know,

    1. What is the measurement in mm, for classifying in to above categories.

    2. Is this measurement done manually using distance measurement tool on axial slices?

    3. For one colon segment, lets say ascending or descending part, does this grading size remain same across all the slices? or can it vary?

    4. How the transverse and sigmoid colon distensions are measured (using which MPR view)?

    Can you please provide some source of information about colon grading. I could not find anywhere in internet.

    - Manjunath

  • Can I carry out overexpression of lncRNAs using something other than traditional mammalian vectors?

    A good point by another post doc in my lab was brought up as I gave my cloning strategy to overexpress my lncRNA during lab meeting...

    Are traditional mammalian vectors the only option?  I need to stably transfect cells.  

    If anyone is doing this type of overexpression which kind of vector are you using? I'm worried about the non coding transcript that would flank my inserted lncRNA at the multiple cloning site. This isn't usually a problem for protein expression, but would potentially pose a problem when studying noncoding RNA function. It seems many publications utilize the traditional expression vector approach...why isn't the lncRNA degraded, or the secondary structure altered?

    Any pointers are appreciated.  Thanks.

    Thanks.

  • What are the best techniques for Image processing in agriculture?

    What are best suitable techniques in image processing to identify the real time change in the region of farm and what are the best suitable techniques to identify the real time change in the leaf of a plant to identify the plant diseases?

    Kampanart Piyathamrongchai · Naresuan University

    You might need to write automated program to process the image. For instance, ArcPy (Geoprocessing using Python script), IDL script (ENVI) etc.  

  • Peter T Breuer added an answer in OpenFOAM:
    OpenFOAM installation on Slackware

    am new to Slackware LINUX environment and so do not know how to install OpenFOAM from the source.The online help pages of OpenFOAM do not tell how to install it on Slackware, although for other linux distributions, the help is available on OpenFOAM documentation site. If anyone have the experience, kindly hwlp me out..It will be a great favor for me...Thanks

    Peter T Breuer · Birmingham City University

    Is there anything special you have to do for OpenFoam (whatever that is! Please provide full explanation in your question). If you have the source, then you compile it (usually make config; make) according to the README, and you install any configuration files where the README says to to install them.

    Please ask the users forum or the developer in case of doubt. This is not the appropriate place.

  • Does anybody know what is the best method for 6 or more objective functions in optimization problem?

    I’m trying to optimize six-objective optimization problem and the problem has 10 variables. I use NSGA-II method for this. But the results are not very good. However, what is the best method in multi-objective optimization problems with more objectives such as 6 or more?
    If anybody knows, help me, thanks!!!!!!

    Bhaba Krishna Mohanty · Indian Institute of Management

    There are lot of methods to solve multiple objective programming problems. May be you can use OWA for this solution.

  • Grace Ngorota asked a question in Likert Scale:
    How best can you analyse likert scale data using SPSS

    please help me with a step to step approach

  • Miguel Ángel Montes added an answer in Pedagogy:
    Are there any colleagues working in the field of mathematics teaching and learning in culturally and linguistically diverse settings?
    I'm really interested in this field of research and I'd like to discuss about with other researchers their theoretical and methodological approaches to the issue of diversity in mathematics education.
    Miguel Ángel Montes · Universidad de Huelva

    I think you could read the work of Nuria Planas from the University of Barcelona, I have read some of her articles of learning in different languages, and found them very interesting. You have an example of her work in the last volume (87, issue 1) of the Educational Studies in Mathematics.

  • Kate L Laskowski added an answer in Fish Behavior:
    How to deal with maximum latency times in behavioral experiments?

    I run some experiments on fish behavior , and extracted some variables from each test (tests are replicated twice). One of the variable is "latency to exit a shelter" which is a classical operational definition for boldness and/or exploratory behavior.

    Although most of my fish left the shelter during the test time (1200 seconds), some of them never left in either replicate 1 and replicate 2 (very shy fish I guess). When estimating repetabilities, I wonder how to treat these maximum latencies (1200 s). I read in the literature that sometimes those values are simply included in the dataset together with the "real" latencies from the other fish. But my concern is that this could overestimate repetabilities since the match between the first and the second replicate is assumed to be perfect (1200 s in both replicates).

    Is there any way to account for this or this is just the way to go?

    Edited: a further concern of including these values is that the distribution of the data could be difficult to handle. For example not considering those values I have a clear poisson or gamma distributions (a lot of values close to zero). But if I include these maximum latencies, then I have an accumulation of data on the right end of the distribution, which complicate thigns I guess.

    Thanks!

    David

    Kate L Laskowski · Leibniz-Institute of Freshwater Ecology and Inland Fisheries

    Hi David,

    This is definitely a tricky problem that most behavioral ecologists run into at some point.  In an ideal world, all individuals would "behave" in all our assays all the time.  That has yet to happen to me though.  Some thoughts on dealing with this:

    1 - How many fish (X out of Y) did not leave the shelter? If it's a fairly small number (~10-15%) then that's good and the few that didn't leave the shelter are actually exhibiting a true "behavior" (that is they are super shy/risk-averse/whatever).  However if a large portion of them (>40%) didn't leave the shelter, then you definitely need to do some tweaking with your assay as clearly a significant portion of the fish view it as too threatening.  Alternatively perhaps the data distribution is more bi-modal (individuals emerge yes/no)?  Though of course, don't force it into a bi-modal distribution if it really is more continuous.

    2 - Remove those individuals or not? Assuming a relatively low proportion of the fish didn't leave the shelter, I'm generally fairly reluctant to throw out data.  Even though those fish didn't emerge, they clearly are still giving you information about their behavior.  However, if you really just want to investigate their behavior within the arena (i.e. after they emerge), you could potentially be justified in removing individuals that didn't emerge BOTH times.  You would then just need to have the caveat that your results/interpretations only apply to those individuals that responded to your assay in a certain way (left the shelter). 

    3 - How to handle the analysis?  As a starting point, I would recommend running the analysis both ways - with and without the non-responders.  Hopefully, your results are robust and won't really change either way, in which case, then you should really keep all the data you collected.  The problem will be if your results are dependent on the inclusion of these non-responders.  If your results/interpretation change based on their inclusion, then you really need to think about what that tells you about your original research question.   This in itself could be interesting though.  This might also be an argument for investigating this behavior as more of a bimodal yes/no behavior?

    4 - In terms of this skewing your repeatability estimate, it of course, could.  I would be more concerned about the non-responders affecting your among-indivdiual variance estimate, especially if you had a lot of other individuals that DID emerge - then it will really increase the variation between your fish.  But again, run the repeatability analysis both ways and see what it says.

    I'm not sure what analyses you're looking to run, but potentially a quasi-Poisson distribution can more adequately model the over-dispersion if including the non-responders skews the data?  Or a negative binomial can be a bit more forgiving than the Poisson.  Or you can try the bimodal route if that seems to fit what you observed. 

    That is generally my thought process when I run into this problem (which is pretty often!).  Good luck!

  • Zhou Xu added an answer in Rare Earth Metals:
    Could TEM melt amorphous alloy?

    Due to their low melting point and low thermal glass stability, the Al-based metallic glasses without rare earth metals that contain magnesium and calcium are unstable under a high voltage (200keV) electron beam and samples have been found to crystallise. However, would the samples melt under any circumstance?

    Zhou Xu · Monash University (Australia)

    It's highly possible that you may melt your sample when you are imaging at high mag, or when your electron beam is converged to a small area. It is more common using STEM where electron beam is focused to one point. Drop the voltage to 80k might help.

  • Zwi Barnea added an answer in Crystallization:
    What methods can I use to check the shape of crystals?

    Dear All

    I have analyzed the quasicrystal i have prepared by xrd, but i'm not sure if the crystallization is correct. I know that we can check it via TEM or another method. May I ask about the other method which we can check the shape of the crystal?

    BR

    Zwi Barnea · University of Melbourne

    You could try tomography.

  • How do I design a distribution system for a factory where there are 11 kV loads, and 415 V loads?

    Transformers selection, cables selections, protection units selection. The load includes induction motors and air-conditioners, pumps, and lighting.

    Muhammad Ramzan · Sukkur Institute of Business Administration

    R= (kV)2 / MW    eq 1

    X = (kV)2 / MVAr eq 2

    Replace Active Load by resistor and reactive by inductor. The values of resistor and inductor may be calculated by eq 1, eq 2.

    This may help you to get important simulation results for any system.

  • Begoña Pellicer added an answer in Emergency:
    Are we doing enough to reduce falls in the emergency department?

    I am doing my Masters In Emergency Care Major Degree and interested in finding out why we still have falls in the Emergency department, find any gaps and then come up with recommendations of what can be done. What measures are other Emergencies implementing?

    Begoña Pellicer · Universidad San Jorge

    Hola, yo tengo varios artículos publicados de caídas en pacientes geriátricos. Te invito a 

  • Does quantum field theory resolve the measurement problem in quantum mechanics?

    Recently I read a paper titled "Quantum field theory solves the problem of the collapse of the wave function" by Alexey V. Melkikh (arXiv:1311.0205v1 -
    quant-ph). An earlier paper on the same topic is " Measurement problem in quantum mechanics" by Michael Danos & Tien D. Kieu (Int. J. Mod. Phys, vol-8, p-257, 1999). Both these papers claim that the measurement problem is completely resolved with in the framework of quantum field theory because it incorporates both the particle and wave aspects, while quantum mechanics deals only with the wave aspect. While the arguments in these papers are convincing, I would like to know the general consensus on this topic.

    Charles Francis · Jesus College, Cambridge

    Leyvraz, I have shown it in mathematics. A quantum current is not classical. It is a different mathematical object. It is no good saying it is just words. It is up to you to learn the mathematical difference which the words describe. The fact that you treat quantum current as a c-number is a very specific mathematical error in your proof. In fact this is so obvious and clear a mathematical error which shows that neither Bohm nor any of the Bohmians have any understanding of quantum mechanics whatsoever. The solution I gave is at the level of a first course in quantum mechanics. It is quite clear than no one who understands qm could think that it obeys a c-number continuity equation.

  • Gaurav Kumar Singh asked a question in Imidazoles:
    A very general query: What is the normal voltage condition for SDS-PAGE containing Ni-NTA eluted protein samples?

    I applied 140, 120. and 100 volts and I have obseved a very random migration of protein sample. It may be due to presence of salts (imidazole, NaCl, TisCl) in the sample. Sometimes the sample gets heated. Any suggestions?? 

  • Josipa Kern added an answer in Informal Learning:
    What do you think about informal learning?

    Informal learning is, by default, any learning that is non-formal learning.

    In recent years, many researchers seem to have rediscovered informal learning.

    Please tell us about your point of view, experiences and so on.

    Josipa Kern · University of Zagreb

    As I understand, informal learning is to acquire new knowledge and skills by the school and / or college. Results informal learning does not have to be (and usually are) not confirmed with a diploma or any other document. Nowadays, most people can not afford formal lifelong learning, and therefore informal learning is very desirable. The problem of informal learning that remains can be expressed by the question: how to confirm the attainment of knowledge / skills? It seems that the answer lies in the development of standards for testing knowledge / skills, the standards which could be used for checking the aquired knowledge / skills, in both formal and informal learning.

  • Boon Lee Chai asked a question in Sectioning:
    How to score the epithelial section of intestine for immunohistochemistry?

    I am confused with scoring the epithelial sections of intestine because there is the vertical and longitudinal section. Which should I score if both structure exist? 

  • How do you best combine focus groups and individual interviews in qualitative research?

    Has anyone experiences in combining focus groups and individual interviews in qual.research?

    I am wondering about what the most fruitful approach would be to investigate into how cancer coordinators contribute to cooperation in interdisciplinary cancer care:

    Starting with focus groups (different stakeholders in the HCS), and going into depth in follow-up individual interviews (with CCs); or starting with individual interviews and basing the focus groups on knowledge derived from individual interviews?

    I am specifically interested in existing literature on combining these methods, and thankful for any input / shared experience or link.

    Thanks!

    Samantha Stressing · University of Southampton

    I personally did them simultaneously, mainly due to time restraints, but actually found this very fruitful as I could add themes from both data collection tools as I went. It also improved my recruitment rate as some participants couldn't attend the focus groups but were keen to contribute in some way, and so were interviewed. Other's did both, either before or after the focus group, as had an interest in the discussion points but wanted to give more in-depth information via a semi-structured interview that they didn't feel they could say in a focus group. This worked well but again may vary in different contexts (e.g. my sample was with a professional body in the UK). It may be that for more sensitive topics, you might want to separate the two, as you may find some topics are not discussed in focus groups.

    There is plenty of literature out there (e.g. Barbour et al 1999 Combining focus groups and interviews: Telling how it is; telling how it feels) sorry I can't think of anything more up to date off the top of my head. Great discussion point though.

  • Does anyone have experience with sound insulation of underfloor heating systems?

    Hi, I am looking for papers and data on impact sound insulation and dynamic stiffness of materials commonly used in these systems, in particular polystyrene.

  • Actor-Network Theory can be used in innovation studies? How?

    I am not very familiar with Actor-Network Theory yet, but as far as I understand it is applied in STS, whereas Innovation studies use maybe more case-studies or so. I am doing a research on innovation in bioenergy diffusion in two regional case studies and I will study actors and networks that characterize the system and also (among other things) how this helps innovation in bioenergy diffusion.

    Thank you in advance

    Bianca

    Romaric Servajean-Hilst · École Polytechnique

    You can also have a look on the work of Eoin Whelan - you have an example of his results in his article "Creating employee networks that deliver open innovation" in the MIT Sloan Management Review in 2011

  • Why can't I see my protein in immunofluorescence assay?

    Hello,

    I am trying to see flag tag protein (clonned in pcDNA plasmid) in U2OS cell lines using immunofluorescence assay. My control (pcDNA+GFP) shows high transfection efficiency (>80%). However, under the microscope I only see that ~5% of the cells contain my flag protein (colored red). My primary antibody is m anti FLAG from SIGMA. my secondary antibody is alexa555 from abcam. 

    I see the protein in western blot using the FLAG antibody.

    Thanks

    Attila Lehotzky · Hungarian Academy of Sciences

    You mention your tagged protein localizes in the nucleus normally. Did you see there? Probably the transport does not work normally or weak because of tagging... 

  • What does the term “Research Culture” mean to you?
    When we discussed about Research Culture, I saw this is an interesting topic that researchers have different opinions about it. Please share your opinion with me.
    Is there any dos and don'ts in research? Is the term Research Culture in existence? Is it positive? Does it have any negative facet?
    Vahid Mohammadi · Shahrekord University

    Dear Dr. Noori Aldallal,

    Thank you so much specially for the useful link.

  • M. K. Meric added an answer in Agronomy:
    Is vertical farming the future of agriculture?
    We all know that arable land is becoming a limited resource and as such is planting vertically really the way to increase production in smaller spaces?
    M. K. Meric · Ege University

    Maybe the following commercial videos give an idea about future of vertical farming...

    http://www.youtube.com/watch?v=hjh97obNgUI

    http://www.youtube.com/watch?v=84zh7XL15n8

  • Misha Soskine added an answer in Protocols:
    Can anyone direct me to a proven-to-work protocol for generating chemically ultra-compatent E.coli cells?

    I've tried several methods: the Inoue et al. MnCl2 method, 0.1M CaCl2 method and MgCl2+CaCl2 method. I managed to get only about 10^5 efficiency.

    I need a proven method for 10^8 - 10^9 efficiency.

    Can anyone please help? 

    Misha Soskine · University of Leuven

    I would just go for electroporation.

  • Timo Seppälä added an answer in Business Models:
    Is there work out there about how to measure the stability of a business model based on financial data?

    I currently test some ways to figure about whether a business model is stable or not like for example the usage of the coefficient of determination used over 10 years. Till now all tests are negative which means that there is no method out there which  can help investors to define businesses as stable fist just based on financial data. Maybe someone has an idea.

    Timo Seppälä · Research Institute of the Finnish Economy, Finland, Helsinki

    Dear Björn,
    Please find our working paper as an enclosure. In that paper we explore the empirical roots of the concept of profiting from product innovation in the industrial and commercial machinery and equipment industry, offer a global value chain analysis of how an EU-27 headquartered firm has employed an effective business model for capturing value added from product innovation. I hope this helps!
    Best Regards
    Timo

  • Condensed Matter Physics

    Can anybody please let me know what the ideality factor (greek symbol eta) in standard current voltage equation of a p-n diode represent? Is it just a factor used for modeling I-V characteristic or it has other signficance ?

    Sebastian Wilken · Carl von Ossietzky Universität Oldenburg

    Hi,

    in a first place, you can say the ideality factor (other usual symbols are n or A) is some kind of form factor which was introduced to describe also "imperfect junctions" with the Shockley equation. Typical values of the ideality factor are between 1 and 2 (sometimes higher).

    On the other hand, the ideality factor has also some physical interpretation and can tell you something about the dominant recombination mechanism. For instance, an ideality factor of 1 is often related to band-to-band recombination, whereas an ideality factor of 2 may indicate a process where tow charge carriers are involved, e.g. recombination within the p-n-junction. However, the interpretation of the ideality factor is often tricky, especially when you use materials other than textbook-like crystalline semiconductors.

  • Remy Fannader added an answer in GAP:
    Is it possible to explain the operational/tactical/strategic classification in terms of real-time KM ?

    The basic idea is to use events and the processing of associated data to bridge the gap between operational and decision-making systems.

    Remy Fannader · caminao

    On the contrary, when information is traced back to events it becomes possible to deal with its origin, human or otherwise, and therefore to take the real world into account.