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

  • Roland Iosif Moraru added an answer in Chimpanzee:
    What makes us human?

    Just looking at our DNA won't tell us – the human genome is 99% identical to a chimpanzee's and, for that matter, 50% to a banana's. We do, however, have bigger brains than most animals – not the biggest, but packed with three times as many neurons as a gorilla (86bn to be exact).

    A lot of the things we once thought distinguishing about us – language, tool-use, recognising yourself in the mirror – are seen in other animals.

    Roland Iosif Moraru · University of Petrosani

    Dear Sarwan

    Maybe you are too hard with us, poor humans. But I understood what you meant and I confess that sometimes I had the same impression.

    Dear Mahmoud, Marcel and Andras,

    Your interactions are adding to this dialog (multi-alog) value and new insights, more profound and -sometimes- shining.

    The last question of Mahmoud (regarding Artificial Intelligence) self-contains the answer too.

    For me the importance of RG consists not only in scientifically correct answers, but in have a confirmation of the fact that "Humans are great not when give answers, but they put questions!" That's me. And here's a quote from Werner Heisenberg.

    "What we observe is not nature itself, but nature exposed to our method of questioning."

  • Is there any difference between Optics and Photonics ?

    As we know, BASIC terminologies and their meanings in science are not something used randomly because they represent some particular or specific ideas! Since I study Optics I tried to understand the clear-cut difference between Optics and Photonics ! Some scholars use them interchangeably. Where as others think that they are two separate entities that Optics represents classical concepts of light while Photonics is for quantum aspects.  For example, in this article,which I found reasonable,( http://optics.org/article/32348 ),  we can see that there is no convention among exerts regarding the two terms! Thus, I perceived that there is no clear-cut difference or we can use them interchangeably! However, I am still not satisfied and want to know more if there is some scientific definition or method to differentiate them clearly! Besides, as fields of study, Optics and Photonics should have clearly defined meanings if they are two different things. 

    Thanks in advance! 

    Alexandr Egorov · Russian Academy of Sciences

    You are right, it is so has developed historically, that there is no binding agreement on use of these terms. It is caused by their known definitions (look, for example, here: http://en.wikipedia.org/wiki/Optics and http://en.wikipedia.org/wiki/Photonics), which are in many respects crossed. In both cases it is a question of light and electromagnetic waves of a visible range and their use, etc. As a whole Photonics is more applied area in comparison with Optics. It is also underlined in specified article: http://en.wikipedia.org/wiki/Photonics
    "The term photonics more specifically connotes:
       - The particle properties of light,
       - The potential of creating signal processing device technologies using photons,
       - The practical application of optics, and
       - An analogy to electronics."


  • Ahmed Elragal added an answer in Research Data:
    What could be the best topic to research in Data Mining?

    Various issues in performance are being regarded a large overhead in Data extraction. Also various query techniques are being used for various purposes. So i need to know what are some new research trends in Data Mining.

    Ahmed Elragal · German University in Cairo (GUC)-Egypt & Luleå University of Technology-Sweden

    I suggest Higher Order Mining (HOM), specially in light of the sheer amount of (big) data available. HOM basically works on extracted models, not on source data which might not be always available e.g.. data streaming, or there is insufficient credentials to obtain it. 

  • Can anyone suggests the working concentration of DAPI for fluorescence studies?
    Concentration of DAPI for fluorescence studies
    Le Thi Thanh Huong · Vinmec International Hospital

    I always use DAPI stain at 5ug/ml  in 2 minutes.

  • Anju Manuja added an answer in MTT Assay:
    Anyone used MTT assay and Human Dermal Fibroblast?

    Hello there,

    Has anyone done an MTT assay on Human Dermal Fibroblast? I'm going to start preforming this as part of my thesis and was wondering if there are tips and things I should lookout for.

    I'm going to be using XTT instead of MTT. Any good protocols out?

    Anju Manuja · National Research Centre on Equines

    with XTT can get soluble Formazon, for MTT you need to dissolve in DMSO, ethanol etc.  

  • Sonali Biswas asked a question in Defects:
    How do we know crystal defect (specially point defect) for a lattice experimentally?

    For example i have doped Co (trivalent) on the side of Mg (divalent) then to maintain charge neutrality there is a possibility of cationic vacancy in lattice. so how do we conform about that vacancy?

  • Subash Paudyal asked a question in Text Mining:
    Best Tool to extract online forum user q&a data?

    Hello, anybody doing research in data mining, text mining or web semantics, please help me out the best way to extract the user behavior from the online forums.


  • Mason N Dean added an answer in Osteology:
    Does anybody has some references on the mineralogy or ultrastructure of the rostrum of Xiphias gladius (Swordfish)?

    Hello all:

    I am looking for any works dealing with the ultrastructure of the rostrum (bill) of any fish in the families Istiophoridae or Xiphiidae (bill-fishes), in particular of swordfish, marlin or similar species.

    I have some osteological works but I am looking for something more structural.

    Thanks in advance,

    Juan Francisco.

    Mason N Dean · Max Planck Institute of Colloids and Interfaces

    glad to share, thanks for the interest - if you end up doing anything with Xiphias, we'd love to hear about it, they're fantastic animals!



  • What's the interpretation of single photon interference in a double slit experiment?

    I want to know what are the reasons of this interference.

    How does quantum mechanics look for this interference? Does the photon interfere with itself or are the waves accompanied with it interfering with each other?

    What's the relation of wave particle duality with this experiment?

    What are the most acceptable interpretations of this experiment?

    Johan Frans Prins · Sage Wise 66 (Pty) Ltd

    Dear Harry,

    I have not ducked anything ever. You NEVER give a fully reasoned response. Why do you think that what you call "antibunching" proves that a photon-wave IS NOT A SINGLE COHERENT WAVE. Please stop wasting my time by expecting from me to guess how your warbled brain works.

  • In your dealings with journals, did reviewers or editors hint or state that you do well to cite articles of that journal? What is your reaction?

    So far I have published in two local journals.  I sent one article to 1 of them in January this year, and got feedback at the end of March.  One reviewer commented that the paper could be accepted, another asked for minor modifications, and a third asked for major modifications and said the paper could not be accepted.  This 3rd reviewer also suggested that I should include references of that Journal B.  But I improved my paper and now the paper is accepted, although I did not cite papers of Journal B.

    After that, I tried to explore a journal with impact factor (C), based in another country. The sub-editor wrote back to say that my paper could not be accepted, although he admitted that I extended the work of 2 other papers, that were quite significant in the field.  He suggested that I should read articles of that Journal C to improve my discussion.  Actually, I'm most willing to read, and also to cite, but I don't have access to many journals, being without a research grant.  I also thought my paper was good because even that sub-editor admitted that I had extended the research.  That gave me a certain hint that I should cite articles in Journal C, although it wasn't plainly stated as done by reviewer of Journal B.  Please let me have your thoughts, thanks.

    Patricia Abrao Possik · Netherlands Cancer Institute

    Dear Miranda,

    I have had comments that I should cite a specific author, and sometimes a specific article, which was supposedly an expert in the field that I had failed to cite properly. I found it acceptable and understood that the reviewer wanted me to give a better overview of the current literature. So in my opinion, if the reviewer or editor of these journals had the same intention, it is acceptable. But if you feel that what they wanted is just that you cite a specific journal, I think it is completely unacceptable and unethical... 

  • Anju Manuja added an answer in Hemolysis:
    Does anyone have a protocol or advice on how to avoid hemolysis while taking blood samples from a mouse?

    I perform a colorimetric assay on serum prepared from these blood samples and the red color due to hemolysis is highly interfering with my readout.

    I tried tail vein, cardiac puncture and still have quite some hemolysis in some of the samples.

    I collect the blood in BD Microtainer SST tubes (ref 365951) and spin them 5 minutes at 10000 rpm, room temperature to prepare the serum.

    Anju Manuja · National Research Centre on Equines

    You can collect the blood in drops from tip of tail using a very small cut. further for serum/plasma collection, pl see  Harris et al., 2007 Infect. Immun. 75(5): 2366-73 

  • İbrahim Karakurt added an answer in Larva:
    Does anyone have identification keys for Gonothrombium (Adult and larvae)?

    I have two gonothrombium species (Both of them includes larvae obtained from the adult female by experimental rearing). The tarsal claw formula 2-2-3 or 3-3-3 for gonothrombium larvae. I don't know for sure.

    İbrahim Karakurt · Erzincan University

    Dear Saboori

    Thank you for your interest. If you can get papers. I will wait for you to send its.

    Best wishes 

  • Mukhlis Ismail asked a question in Materials:
    What is the different between multifferroic and magentoelectric materials?

    different between multifferroic and magentoelectric materials

  • Can anyone tell me the disadvantages or demerits of dry clinical chemistry analyzer over wet analyzers?
    I have worked a lot on fully and semi-automated analyzers but all instruments were using Wet chemistry reagents. But now we have got a dry chemistry Vitros 250 analyzer. Actually I know a few demerits but if anybody know something more.
    Sutirtha Chakraborty · Peerless Hospital & B.K. Roy Research Center

    The Vitros is really good if you can maintain the lab temperature, dust etc. Comparability of results for some analytes is an issue.

    It has Direct ISE which is a great advantage for electrolytes particularly Sodium.

    It has enzymatic creatinine assay which is much better than the age old Jaffe Kinetic!

  • Andrew Ekstrom added an answer in JMP:
    Is there any way to fit a nonlinear model where we have more than one independent variable?

    I am essentially talking about fitting a model with three independent variables. We are having the data from a biological experiment where the response is showing a sigmoid fashion, thus prohibiting fitting of a linear or polynomial model.

    Also, If anyone ever tried JMP statistical software for kind of analysis please share how you did it.

    Thanks for your time,


    Andrew Ekstrom · University of Michigan

    What is your response variable?

    For example, if your response is % yield, the transform for this data is a Logit.

    If your response is a concentration/rate, you should use a Poisson regression. 

    JMP is a very powerful piece of software. It will have many methods for performing non-linear regression. 

  • Sonia Debattista asked a question in Stock Solution:
    How can I store stock solutions of imipenem?

    Can I prepare microtitre plates with imipenem for broth microdilution and freeze them at -70C? Thank you.

  • Daniel Matovu asked a question in BDNF:
    By what cellular molecular mechanism does cortisol and BDNF inhibit release of CRH in the hypothalamus?

    If anyone is working on the same question, l will be glad to receive a feedback. Thanx

  • Marcel Van de Vel added an answer in Mathematics:
    How does the current view of infinity differ from Greek mathematics?
    Infinity in mathematics is a property of a set of objects that is not finite. The traditional view of infinity has its origin in the writings of Aristotle and the notion of potential infinity. "It is always possible to think of a large number of things, for the number of times a magnitude can be bisected is infinite. Hence the infinite is potential, never actual; the number of parts that can be taken always surpasses any assigned number." [Physics 207b8] ). For the current view of infinity, see the attached file.
    Marcel Van de Vel · VU University Amsterdam

    Dear Geng, can you clarify your view by choosing a position in the following dilemma:

    (a) A paradox is truly a contradiction between mathematical results and (by the rules of logic) invalidates  at least the whole related branch of mathematics, in this case: analysis -- in particular, calculus.

    (b) "Paradox" refers to a (philosophical) experience of contradiction with the intuition. It occurs in neglect of certain strict rules of mathematical manipulations and points at a possible correction of our intuition. It actually does not endanger any part of current mathematics.

    I really enjoy reading about cleverly designed paradoxes based on pure intuition, as this is witnessing a sharpness of mind. At best, it may even provide a reason for trying out some alternative mathematics (e.g., finite mathematics). But I strongly oppose unfounded claims of contradictions in mathematics.

  • Sonia Debattista asked a question in Stock Solution:
    How can I store stock solutions of imipenem?

    Can I prepare microtiter plates with imipenem for broth microdilution and  freeze them at -70C ? Thank you.

  • M. K. Bhanarkar added an answer in HFSS:
    Can Anyone tell me how to add new material in HFSS?


    Can any one tell me how to add new material in HFSS?

    which property do I  have to understand for adding new material ?

    M. K. Bhanarkar · Shivaji University, Kolhapur

    as per your needs, occurances and interest, FR4, RTduroid, silicon

  • Arie Wahyu added an answer in Clustering:
    What is the best clustering (pre-partitioning) method for large scale datasets with size constraints?

    I have a large data set. I want to apply an algorithm that is not scalable and requires some small data sets. So, I have to partition the initial data set into two clusters with almost the same sizes and of course at the same time, SSE (or MSE) are minimized. you help is appreciated.

    Arie Wahyu · Bandung Institute of Technology

    Dear Mr Mortazavi,

    You can try Fuzzy C-Means (FCM), because its simplicity is powerful to handle very large data, as proven in current research.
    You can refer to this paper for more detail:
    (Fuzzy C-Means Algorithm for Very Large Data)

    Good Luck

  • Le-Duy Pham added an answer in Autophagosomes:
    How should one interpret LC3 puncta in immunofluorescence?

    Hi all,

    I am trying to detect autophagy in primary blood neutrophils using LC3 puncta as markers.

    I have attached 2 figures with different morphology of LC3 distribution (green color).

    I speculated that: In the Ctrl figure, LC3 is accumulated which indicated fewer autophagosome. In treated cells, LC3 puncta distributed in the cytosol indicating a higher level of autophagosome.

    Am I right? Could you please let me know your opinion to interpret those figures?

    Thank you very much for your help.

    Le-Duy Pham · Ajou University

    Thank you Phillippe,

    However, LC3 is an intracellular molecules. Could that phenomenon happen to those molecule?

    Thank you again!

  • What does mean by dispersion and distribution of the filler into polymer matrix ?

    Or why good dispersion and bad distribution of filler is good for electrical conductivity ? Thanks in advance 

    Alain Celzard · University of Lorraine

    Distribution is the way the particles fill the space, whereas dispersion is the way these particles are agglomerated or not. With a good distribution, each particle is as far as possible from its nearest neighbour, so that the space is homogeneoulsy filled with particles. With a good dispersion, all particles have the same shape and size, as small as possible, as no agglomerates exist. Therefore, it is quite possible to have good distribution but poor dispersion, or poor disribution and good dispersion, see attached Figure. If particles are conducting and if you want a high conductivity, you shoud indeed prefer the situation in which particles can make a conducting path by touching each other, but agglomerates should be avoided as many particles would be useless because behaving as dead ends for the conducting path.


  • Zhou Hongyang asked a question in Comsol:
    How can l set the stop condition in transient solver of comsol?

    The stop condition is the rate of electric potential change<0.1; as Fig shown. I know what is the stop condition, but how can I express it in comsol??

    Thanks very much~~~~

  • Le-Duy Pham asked a question in Myeloperoxidase:
    IL-8 can affect the release of neutrophil MPO (myeloperoxidase)?

    Hello all,

    As I know, IL-8 can trigger neutrophil degranulation and therefore induce the release of MPO into the culture supernatant. However, I could not find any study investigating the direct effect of IL-8 on MPO production ex vivo.

    Is there anyone has tested the effect of IL-8 on MPO release from neutrophils? How is the phenomenon?

    Thank you very much for your information!

  • Ram Nageena Singh added an answer in PCR:
    Any recommendations for a good thermocycler?
    My lab is looking to finally get our own thermocycler. We currently borrow a MJ Research PTC 200, which works wonderfully, but they are no longer manufactured. We have been looking at the Bio-Rad C1000 and S1000, and the GeneAmp PCR System 9700. Does anybody have any advice? We need: temperature gradient, heated lid, relatively easy to use, and not really different from the PTC 200 in terms of reliability and consistency.

    Ram Nageena Singh · Indian Agricultural Research Institute

    Bio-Rad C-1000 and Varity (ABI) are very good Thermal cyclers.

  • In what extent climate change adaptation has been taken into account?

    What is the level of progress in climate change adaptation in your country?

  • Yuri Rylov added an answer in Riemannian Geometry:
    Can geometry have no definite dimension?

    Presentation of the Riemannian geometry begins sa follows: "Let us consider a manifold, where there is a coordinate system, and dimension of the manifold is equal n. Does it mean, that the dimension is a fundamental concept, which cannot be expressed via another more fundamental geometric concepts?

    Yuri Rylov · Russian Academy of Sciences

    Dear Eric,  Unfortunately mathematicians do not able to construct a generalized gtometry as a deformation of the proper Euclidean geometry. The can only sew a generalized geometry from pieces of the Euclidean geometry. For such a sewing they needs a topology. If a generalized geometry is constructed as a deformation of the Euclidean geometry, it obtains new properties. It may be multivariant. It may have no definite dimension, which is defined in Euclidean geometry  as maximal number of linear independent vectors. 

    For details, see, for instance  "Geometry without topology" http://arXiv.org/abs/math.MG/0002161

  • How can one build Knowledge Management Infrastructure in an organization?

    Building knowledge management infrastructure in an organization is essential to get many required benefits. How/what factors/issues should be considered to do so? Your respected answers and experiences are so welcomed and needed.

    Ra'ed (Moh'd Taisir) Masa'deh · University of Jordan

    Thank you Fung for your great detailed contribution.

  • Hamid Nadri asked a question in Sybyl:
    Would anyone intoduce me a free software for doing receptor-based 3d QSAR study? Is there any softwre except SYBYL for doing that?

    Would anyone introduce me a free software for doing receptor-based 3d QSAR study? Is there any software except SYBYL for doing that?