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

Browse by research topic to find out what others in your field are discussing.

Browse Topics

  • Montadhar Almoussawi added an answer in ANSYS:
    Does anyone know how to make heat flux in Fluent as a function of coordinates?
    I need to represent heat flux as a function of cylindrical coordinates in my model but I didnt find a way to do that. Some would say use the UDF but I still need help on how to do that.
    Montadhar Almoussawi · Sheffield Hallam University

    thanks it helpfull

  • Leo Gurney added an answer in DNA Contamination:
    Do I need to validate qPCR arrays with separate qPCR of individual genes of interest?

    Dear all,

    Apologies if this question is daft but I am new to qPCR - therefore any advice gratefully received.

    I will be performing qPCR arrays of 42 genes for comparison of two conditions on a series of 96 well plates i.e. Replicated twice on each plate: 42 GOI, 3x housekeeping, 1x Reverse Transcription Control, 1x Positive PCR Control and 1x Human Genomic DNA Contamination Control (these plates are already purchased and ready to go).

    For the subset of GOI that are maximally differentially expressed in my conditions I could perform individual qPCR, however this would involve me needing to purchase individual primer sets etc; whereas I currently have the capacity just to increase the n of my arrays.

    I am uncertain of the relative disadvantages / advantages of either approach and would appreciate all help given.



    Leo Gurney · Newcastle University

    Thanks John - I'll take that on board

  • Alexander Kukalev added an answer in Optimisation:
    How do I remove IgG band covering my protein sample while doing a western blot for ChIP?

    I am optimising ChIP for my protein which is approx. 45kDa in size. Upon doing Western Blot to check my pulldown I see a big IgG band that covers up my protein. Can anyone suggest me how to resolve this? qPCR is another option but I want to first see the pulldown by Western blotting.

    Also, can some one suggest me secondary antibodies that do not recognise the IgG have chain that I can use to avoid this situation?

    Alexander Kukalev · Max-Delbrück-Centrum für Molekulare Medizin

    You can try the suggestion from Katrin, even so in my experience, light-chain specific secondary NEVER worked well :) Whatever salesmen tells you, in reality such AB always gave strong cross-reactivity with heavy chains. However, another thing you can do is to simply remove DTT or beta-mercapto (whatever you are using) from the sample buffer and boil your samples for a shorter period of time. In this case, most of your AB do not brake into light and heavy chains (partially they still do, just due to the heating, but to much lesser extent) and you have much higher chances to resolve your protein of interest from IgGs.

  • Sujayraj R.S added an answer in Cancer Research:
    Do any sporadic (non NF associated) MPNST cell lines exist?
    I'm looking for MPNST cell lines that are strictly from sporadic (non NF associated) MPNSTs to compare to NF associated MPNST. I know of STS-26T and HS-Sch-2, but do others exist? There seem to be very few.
    Sujayraj R.S · Mangalore university

    Non NF associated MPNST do exist but the lifetime risk of having only MPNST  have a 0.001% chances in the general population....

    ST88-14, and NF90-8 are the other cell lines on which you will find few work done...

    Find the attached articles to know more..

    Hope it will be helpful...

    All the best

  • Samuel A Awe asked a question in FactSage:
    Does anyone has information on thermodynamic data for lithium interaction with slag and matte phases during copper metallurgy?

    I am interested in making thermo calculation of Li distribution in Slag, matte and metal phases using FactSage software. Unfortunately, thermodynamic data relating to these systems are not available in FactSage data bases. Could someone provide me a useful information in this regards. Many thanks for your response.

  • Can someone help me in finding tools or papers regarding to sentiment analysis support systems in collaborative decision-making?

    I want to start a research regarding to sentiment analysis support systems in collaborative decision-making and please help me with some references and remarks. 

    Lucian-Vasile Szabo · West University of Timisoara


    You will try to find information in this researches

  • Which ResearchGate features you find most useful and how could they be further improved?
    Which ResearchGate features are most useful to you and how would you like to improve them?
    Balázs Székely · Eötvös Loránd University

    An update: the improved way of presenting Stats (introduced last week (?)) is really a great deal, IMHO. I find it very transparent and an order of magnitude more informative than the previous version (which was not bad, but this one is much better). Thanks, RG! Balázs

  • Vesna Šukalović added an answer in Buffer:
    Is this a proper method for SOD assay?

    I'm trying to check rat's liver homogenate's SOD activity based on Marklund's method (Marklund, S. and Marklund, G., Eur. J. Biochem., 47, 469-474, 1974). However, I have a problem that liver homogenate have color enough to affect to the absorbance in 420nm. So I designed it's solution.


    I made 3 groups.

    A : buffer 2.6ml + DW 0.2ml + pyrogallol 0.1ml

    B : buffer 2.6ml + sample 0.2ml + pyrogallol 0.1ml

    C : buffer 2.6ml + sample 0.2ml + DW 0.1ml

    reaction is stopped by adding 0.1ml of 1M HCl after 10 min.

    * buffer is 50mM Tris-HCl(+10mM EDTA, pH 8.5)

    sample means liver homogenate

    In group A, pyrogallol will be oxidized,

    In group B, pyrogallol's oxidation will be depressed because of sample

    In group C, the liquid is cloudy because of sample but may not be changed in absorbance.



    % inhibition = [1-{(B-C) / A}] * 100

    - the capitals mean the difference of absorbance for each group.


    I thought this idea, and is it available or how can I fix it properly?

    If it is absolutely wrong, what is your recommended method?

    Vesna Šukalović · University of Belgrade

    Dear Chung-Su Kim,

     If the samples turbidity is the the only problem, try to centrifuge samples just before absorbance reading. 

  • Paul Hibbert added an answer in Leadership:
    How to identify and measure responsible leadership? Is any link between responsible leadership and competencies?

    I'm interested in research about the responsible leadership and I am looking for some references, research, surveys, case studies, and suggestions of methods. Thank all for any help;

    Paul Hibbert · University of St Andrews

    In some recent research it's my colleague Ann Cunliffe, we argue that a capacity for responsible management (and leadership) is related to reflexive practices. That is, critical and self-awareness are strongly connected with the development of responsibility.  I have attached our paper.

    But I also recommend that you look at work on authentic leadership - writing in this area ofree has a strong focus on moral development, and so is likely to be useful. One good recent paper in this area - as a starting point - is:

    Algera, M. & Lips-Wiersma, M. (2012). radical authentic leadership: Co-creating the conditions under which all members of the organization can be authentic. Leadership Quarterly, 10, 118-131.

  • Palyam Subramanyam asked a question in Quantum Dots:
    How to make Bi2s3 and Sb2s3 quantum dot solar ?

    please give me information,

  • Are there any effects of hydrogen peroxide on the arbuscular mycorrhizal colonization?

    Can anybody help me to know about the effect of hydrogen peroxide on the arbuscular mycorrhizal colonization? Are there any beneficial effects hydrogen peroxide on the cell functions?

    P. Pardha-Saradhi · University of Delhi

    Yes, H2O2 will have effect of colonization of arbuscular mycorrhizal fungi. It depends on the concentration of H2O2. At lower concentrations it can help in signal transduction and play critical role in expression of several genes. Above threshold levels it can disrupt cellular metabolism directly or by promoting generation of OH. etc. You may download Sharmila et al. (2009) from our Reserachgate account.

  • Zheng Feei Ma asked a question in Thyroglobulin:
    Should we use Tg (thyroglobulin) CRM-457 as our quality control material when analysing Tg?

    Tg, thyroglobulin, thyroid, iodine 

  • Le Phuc Nguyen added an answer in Biomass:
    Can anyone know what is the acceptable pressure from Nitrogen gas regulator ?

    I need nitrogen gas to purge my biomass and I need to buy gas regulatore for scientific purposes, so what is the  acceptable and safe pressure of Nitrogen gas that can be released out from gas regulator to purge a biomass safely?

    Le Phuc Nguyen · Vietnam Petroleum Institute

    a 20 bar regulator is enough for you

    B R,

  • Halina E Tegetmeyer added an answer in Methanotroph:
    Can anyone suggest me Primer (f & r) sequence for methyl coenzyme-M reductase (mcrA) gene &particulate methane monooxygenase (pmoA) for DGGE analysis?

    I am doing experiment waste water methane production and oxidation. I used acetate as a carbon source in the Synthetic Waste Water. I want to detect Methanogens and Methanotrophs in my systems and in my lab, we can do DGGE analysis. Therefore I request relative researcher to help me to prepare the gene specific primer for DGGE analysis that possible cover most of the Methanogens and Methanotrophs. Any references in this regard will be highly appreciated.

    Halina E Tegetmeyer · Alfred Wegener Institute Helmholtz Centre for Polar and Marine Research

    For mcrA amplification, the paper by Narihiro and Sekiguchi also lists the primer pair ME1/ME2, designed by Hales et al., 1996 (aem.asm.org/content/62/2/668), which we used for taxonomic characterization of uncultured methanogens (http://www.sciencedirect.com/science/article/pii/S0168165612002349). The PCR product length is about 750bp.

  • If I have a polyclonal primary antibiody raised in a rabbit and a primary monoclonal antibody raised in a mouse can I add them both at the same time?

    I am interested in undertaking double antigen labelling immunohistochemistry. Does anyone have any experience with this? In particular, which of the primary antibodies should I add first? Alternatively, can I add them both at the same time as they are directed towards different antigens and raised in different species.?

    Henrik Martens · Synaptic Systems GmbH

    Hi Richard,

    pay attention the minimal cross-reactivity of your secondary antibody to the other species. Many secondary reagents are offered as cross-adsorbed variants. Cross-reacticve antibodies reacting with other than the target species have been removed.



  • Tobi Oshodi added an answer in Pashtuns:
    How to theorize or under what theoretical framework to study lost significance or neglected native language of the majority ethnic group?

    In Pakistan, different ethnic identities live and normally have grievances against each other. Almost all the ethnic identities take pride in their respective cultures, especially language e.g., Pashtunes, Baluchis, Sindhis, etc. But Punjabis, which comprise biggest ethnic identity in the country, normally do now take pride in speaking their native language. They either use Urdu or English to interact with each other. They do not normally let their children speak Punjabi. Parents speak Punjabi with each other but speak Urdu with their kids. 

    What theories explain this phenomenon? One explanation is that when a community feels itself politically and economically deprived, it strives to claim a 'nationality' rather than an ethnic identity, and therefore, focuses on the native language - a characteristic of a nation. Sometimes dialects of the same language are claimed as separate language because of the political and economic differences between people speaking these dialects. 

    Other than that what theories can explain this phenomenon?

    Tobi Oshodi · KU Leuven

    To a large extent, numerous theories and theoretical frameworks could be adopted to explain the tendency for parents to speak to their kids in certain languages or, at a broader level, why certain native languages are gaining more grounds than others in a multi-ethnic setting. For sure, the foregoing interventions from colleagues above remain valid only to the extent that societies are considered as an evolving entity with sometimes unpredictable "tentative stops." Numerous logic guides these tentative stops - one of which could be in terms of the expansions or shrinkage of languages - as (variedly) propelled by socioeconomic factors that are in themselves shaped and reshaped by the precolonial, colonial and post-colonial realities and experiences of respective societies. Thus, while I agree that perceptions of ethnic groups ('we' versus 'them') could influence the expansion or shrinkage in the use of native languages, there are other instances where rather than expand or shrink, existing groups have struggled to promote hybrid languages like the Pidgin English in Nigeria. Yet there are instances where certain natives languages have 'naturally' been adopted by other groups in society or at least a systematic/historical import of certain languages into others as for instance the impact of Hausa language on other languages in some West Africa. In other sense, some languages have developed and have become popular among non-speakers as with the popularity of Twi among Ghanians. My point is that while these tentative stops could be located within the context of post-colonial theory or even Marxian theory, the relevance of ethnic entrepreneurs suggests that the good old elite theory and group theory could also be useful. More importantly, apart from socialization theories, depending on the role (or otherwise) of the state in this expansion or shrinkage, the theory of horizontal inequality could be useful. At least for the Nigerian situation, Onigu Otite’s (1976) thesis of “marginal systemic analysis” in understanding such phenomenon could also be useful (i.e. his “On The Concept of A Nigerian Society,” in A. O. Sanda (ed.). Ethnic Relations in Nigeria, Ibadan: The Department of Sociology, University of Ibadan). Ultimately, I think your particular area of interest, discipline, period of study and subjective drives will determine your choice. This is not to discredit triangulation... 

  • Gábor Seress added an answer in Animals:
    Could someone suggest a recent textbook on zootaxonomy & animal evolution & phylogeny for teaching purposes which covers ca. the whole Animal kingdom?

    I'd prefer a book using results based on both molecular and classical methods. If there's no such book covering the whole animal phylogeny, then I'd also welcome a book on "Chordata" or "Vertebrata".

    Gábor Seress · University of Pannonia, Veszprém

    Thank you all your helpful answers, these are the books I've looked for!

  • Amandeep Kaur asked a question in Dance Therapy:
    What are the various effects of dance therapy seen in a clinical or general population?

    I want to do a study with dance therapy as my intervention. I am unable to find a variable which hasn't been researched upon and is also/can be affected by dance therapy. can i get any suggestions?

  • Shafiq UR Rehman asked a question in Library Science:
    What is the difference between information science and library science?

    please response

  • Aisha Y. Malik added an answer in Health Statistics:
    Do we need an ethical approval to conduct an observational-retrospective human genetic study and why?

    I assume that we want to conduct a small observational-retrospective human genetic study and publish it to a journal. Example subject: detected Down syndrome rate in a city from 2001 to 2010. Our laboratory already has necessary data because we have done this test for ten years and data were save automatically by the data management system.

    So do we need an ethical approval, why and how to get it?

    If we need one, so how do the national health statistics office conduct their job in this case, for a nation?

    Thank you.

    Aisha Y. Malik · Ethox Research Associate, Ethox Centre

    There is a question I want to ask: what is the purpose of this publication/research?

    The answer could/ would be any of the following (and perhaps more):
    1. Publish for academic interest
    2. Help improve detection rate
    3. Make some sort of guidelines for detection
    These purposes make this research different from a census. The data collected for census may be anonymous /non identifiable and is perhaps for internal publications only, as confidential report to guide policy etc., BUT this (your) research will be using that retrospectively collected data for external publication in a peer-reviewed journal, for consumption by a wider group of people (albeit academics).

    Research Ethics Committee (REC):
    Non-identification and anonymity are important for two reasons (both ethical):
    1. Confidentiality and 2. Non-maleficence (the harm that may be caused by identifying that group/peoples). Having said this, I am sure you have thought of these yourself as well. However, it is important that a REC is contacted which will be able to guide you on how to:
    1. Maintain confidentiality –so perhaps it may be that they say that if the data cannot be linked to individuals it is exempt from review. BUT if there is any possibility of identification they may want to review it –
    2. Obtain consent (from the participants of the original data-set) for this publication (difficult though it may be with a retrospective study –from 2001-2010- to obtain consent from ALL those in the original data-set –even if it had it all the identifiers).
    The above can be dealt with by a REC (which may exempt or expedite the review!!!).

    National Bioethics Committee:
    IF the publication is by an independent/private laboratory then there may be a National Bioethics Committee (NBC)-  perhaps the best bet is to write to your national research council for information on this.

    Survey studies:
    As regards survey based studies –it is /may be essential to obtain ethical approval because sometimes survey questions lead to identification of a group (no matter how small). And, briefly, if the survey is on a particularly sensitive issue then there is the problem of stigmatization/vulnerability.

    I hope this is useful.

    Good Luck

  • Isn't now a great time to start the baseline of a longitudinal study of Non Communicable Diseases, especially cardiovascular disease, in Cuba?

    Now might be a great time to start the baseline of a longitudinal study of NCDs, especially cardiovascular disease, in Cuba before foreign direct investment by companies such as McDonald's, Yum Brands, etc. takes over the island. It would be interesting to see if, as incomes rise and people have more disposable income, whether they eat fast food, whether their BMI increases and if this causes higher cardiovascular morbidity and mortality. We have anecdotal evidence from East Asia following the 1997 currency crisis, where because the value of the bhat and other currencies fell relative to the dollar, people could not afford to eat fast food as much as they had been. People reported that they didn't eat fast food as much and felt better after moving back to a more traditional diet but there is no quantitative evidence of the effects on the incidence of cardiovascular disease.

    Just a thought.

    Thierry C Gillebert · Ghent University

    Hi David,

    This is an extremely interesting topic. I could direct you to the European Cardiovascular Disease Statistics 4th edition 2012, published in the European Heart Journal. You can easily see the consequences of liberalisation in Central- and East-European countries. You presumably know these data. 

    Last week I found a fascinating contribution on South-West China insurance registries by Gregory Lip and collaborators in Chest, Jan 2015 (DOI: 10.1378/chest.14-0321) One of the investigated topics were the longitudinal trends in the prevalence of atrial fibrillation, a proxy for cardiovascular diseases. Over an 11-year period, the prevalence of AF increased 20-fold, whereas AF-related stroke increased 13-fold! 

    Best regards,


  • Hello to all. Can anyone tell me what are dimensions of strategic performance of supply chain in automotive industries?

    what are the dimensions of strategic performance of supply chain (SPSC) in automotive industries if we assumed  SPSC as dependent variable.

  • Baljit Singh added an answer in Social Engineering:
    I am doing my Ph.D. on e-learning security and password security problems and challenges. Anyone who is interested in joining research on the above?

    I published a paper on e-learning platforms security issues and I just submitted an extensive version.

    I am working on password complexity, strength, dictionary attacks and how those things changed over the years, what is the situation today, and what we can do to improve it. I am researching the password strength against dictionary attack based not only on strength and complexitiy but also on social engineering and cultural aspects.

    If there is any interest, please contact me.

    Baljit Singh · Kurukshetra University

    Dear George.

    Find your discussion interested so just joined in. I have gone through the answer of Mr. Abdelrahman Osman on plagiarism. Plagiarism in E-Learning of E-contents is most challenging term to tackle. Now these days the world of E-learning or E-education is going through plagiarism which makes the orginality of content to be lost at wrong hands. Contents on E-learning or E-education are being presented either in same way or after making irrelevant changes because of plagiarism. 

  • Each EDM is actually a powder EDM?

    If we look at Powder Mixed Electrical Discharge Machining using nanoparticles and analyze, then we would not have to handle any electrical discharge machining so, because even the most removal-solid particulate components are in the micron range.

  • Closed form solution for mixed Poisson-Gaussian distribution?

    Can anyone can simplify the attached distribution, that is, the convolution of a Poisson distribution and a Gaussian distribution? An approximation which holds for all \theta (small and large) is also acceptable.

    Robert Verity · Imperial College London


    I see. In that case it might be a tricky one. Perhaps you could approximate the shape of the Poisson with a gamma distribution, or a normal-inverse-gaussian with the same first few moments? Both of these are conjugate to the normal and can then be integrated over analytically (replacing your sum over a Poisson distribution). Replacing a discrete distribution with a continuous one is not ideal, but this does necessarily mean that the final answer won't turn out close enough.

    Some other ideas (none of them thought through very well); perhaps you could approximate the normal with a gamma distribution, in which case you can sum over the Poisson to get a non-central chi-square distribution. Or perhaps you could replace the normal with a binomial approximation, which is conjugate to the Poisson? Not convinced that either of these ideas would work.


  • Zheng Feei Ma asked a question in Adjustment:
    How do we use intra-individual variation to correct for a biological distribution?

    intra-individual variation, biological distribution, statistics, adjustment

  • Can anyone suggest how to perform Histone ChIP seq on low number of cells ?

    I would like to perform ChIP seq for Histone modifications on primary cells.The number of cells are below 10,000. I would appreciate help from someone who has experience working with such low number ChIP protocols. I have read some papers about low ChIP though. Any suggestions or tricks are welcome. Thank you

    Rajendra Kumar Chauhan · Erasmus MC

    Dear Pavan,

    Thanks a lot

    I already had look at iChIP protocol earlier and trying to work on it.Seems to be very helpful.Lets see,If that works..Still discussing with sequencing facility for adapter ligation etc.Will update you ..

  • Sulie L Chang added an answer in Alcohols:
    Alcohol is oxidized further in the presence of oxygen. Can you suggest any paper or references regarding this?

    Aerobic oxidation of alcohols

    Sulie L Chang · Seton Hall University

    This 1985 paper is about organic chemistry of alcohol oxidation. Is this what you look for?

    March, Jerry (1985), Advanced Organic Chemistry: Reactions, Mechanisms, and Structure (3rd ed.), New York: Wiley, ISBN 0-471-85472-7

  • Uma Sriram added an answer in T-Cell Culture:
    What medium is best for transfecting human T cells?

    I am also new to transfection protocols and right now I am trying to do an siRNA on human T cells. Which is the best serum free medium to use? I usually use X-vivo 20 for my regular T cell culture. Can I use the same without serum for transfection?Thanks in advance for the replies.

    Uma Sriram · Temple University

    ok. that's good to know .Thanks.

  • How would gold mobility change with metamorphic grade?

    If gold mineralisation occurs very early in the orogenic cycle (i.e. pre-pre-peak metamorphism) how would we expect the gold to re-mobilise through the prograde-retrograde metamorphic loop? (Assuming that the peak metamorphic grade reached is the granulite facies).

    Any suggestions for papers discussing this would also be welcome.