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.

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

Browse Topics

A B C D E F G H I J K L M N O P Q R S T U V W X Y Z
  • Is there any analogous protein for TGFB1 to detect in plasma through ELISA?

    I dont have kit but rather have the antibodies and OPD to detect my samples. But problem does arise based on the standard samples. Any possible outcome apart from kit based assay. Yes making recombinant protein is quite a solution but would like to know any possibilities of an analogous protein for TGFB1 standard assay 

    Saumyadip Sarkar · Institute of Life Sciences

    Dear Bassem

    Yes recombinant protein is important and will go for that.

    Dear Prakash

    Yes recombinant protein is required. What if recombinant protein is made using complement cells? Would that be cheap and efficient?

  • Sushil Kumar Sharma asked a question in Social Media:
    Do Social Media have any influence on society or its just an activity of a few technosavy geeks ?

    Do Social Media have any influence on society or its just an activity of a few technosavy geeks ? 

    A few people keep posting their view / opinions on the social media. 

    Most of the time they are unaware of ground realities. 

    Do these people really have any influence over society or its just an assumption?

  • John F Black added an answer in Fiber Optics:
    Is it possible to send electrical power through a fiber optics cable?

    Is it possible to send electrical power through fiber optics cable??

    John F Black · Start-up Company

    Yes - JDSU has this http://www.jdsu.com/en-us/power-over-fiber/Pages/default.aspx#.VJXXPl4DA 

  • Can anybody tell me how to determine Faraday efficiency of alkaline and Direct methanol fuel cells?

    Faraday efficiency is defined as ratio of observed cell current to estimated theoretical current. I am just wondering how to determine the theoretical current for for given gas by using Faraday's law.

  • Can anyone help me with the calculation of temporal patterns in an enteric methane emissions trial?

    How can I unify data from one year of measurements without making an average of averages?

    We were informed that data collection was carried out approximately one week in each of the seasons of one year.

    My experiment was done in a randomized block design with three replications. Is there a stochastic pattern that is likely to mess up this temporal analysis?

    Any feedback is welcome!

    Susantha Jayasundara · University of Guelph

    Dear Raphael,

    While searching for some literature to derive enteric CH4 emission factors for grazing beef cattle, I came across on following papers that might be useful for your question.
    Lassey, K.R., Pinares-Pati˜nob, C.S., Martina, J.R., Molanob, G. And McMillan, A.M.S. (2011) Enteric methane emission rates determined by the SF6 tracer technique: Temporal patterns and averaging periods. Animal Feed Science and Technology 166– 167 (2011) 183– 191.
    McCaughey, W. P., Wittenberg, K. and Corrigan, D. 1999. Impact of pasture type on methane production by lactating beef cows. Can. J. Anim. Sci. 79: 221–226. (attached below)

    I did not attached Lassey et al. 2011 paper since I am not sure about copyright issues. If you cannot access it, please let me know. I will send a PDF copy.

    I have not involved in measuring enteric CH4 emissions, but have read few papers as part estimating GHG intensity (carbon footprint) of milk and meat from cattle. Your question is an interesting one. From what I have read, I think grazing season may have an effect on enteric methane production (g CH4/kg DMI) since pasture quality seems to vary depending on the season (e.g. spring vs. summer).

    Susantha.

  • Dona Strauss added an answer in Topological Groups:
    Is every neighborhood of identity in an abelian topological group absorbing?

    Let G be an abelian topological group and U be a neighborhood at identity. Do we have the identity that the union of nU in which n is a positive integer equals to whole of G? We have the same situation in a topological vector space. I am interested to know if it is true for topological groups, too.

    Dona Strauss · University of Leeds

    Let G be any abelian topological group. If H = G x Z_2, then G x {0} is a neighbourhood of the identity in H and is not absorbing.

  • Davood Shaghaghi asked a question in PID Control:
    Any body know about PD Controller tuning rules ?

    I want to design a controller for a model that has an integrator .For this reason, i would to design a PD Controller instead of PID and so on. almost of books and refs discuss about tuning rules of PI and PID controllers. Is there any rules about tuning of PD Controller ?

  • Ali Isbilir added an answer in Peptide Synthesis:
    What is a good Europe-based company for custom peptide synthesis?

    Dear colleagues,

    This is the first time I need a customly synthesized peptide for in vitro use. I, of course, found a lot of companies on the internet, but I guess it is better to get an opinion from the people who are already experienced on this field. 

    All in all, could you suggest me any European company for custom peptide synthesis?
    Thank you all in advance!

    Ali Isbilir

    Ali Isbilir · Bogazici University

    Thanks all. I found Biomatik (a Canadian-based company though). They offer better prices compared to the other compaines you offered so far.

  • What was most useful to you in your postdoctoral training?

    In thinking about training of postdocs with less resources, I am interested in hearing what are the most value parts of the postdoc experience, what works well, etc as seen from the perspective of those who have continued in research. Viewed as an apprenticeship what types of teaching helped you most and over the longer term.

    Michael Helmut Werner Hoffmann · Universität Ulm

    I am an engineering doctor. As more than 90% of German engineering doctors, I worked for industry after completing my doctorate. I did that for six years, before I became a professor. These six years of experience were the best preparation for teaching, I could imagine, since I had to explain my ideas to customers, and since I had to find out in practice what was relevant and what was not relevant.

  • Ali Al-Mehdar asked a question in Laboratory Animals:
    Is streptozocin not effective to induce diabetes in rabbits?

    I tried to induce type 2 diabetes in rabbits with the usual dose of sreptozocin 65 mg/kg intraperitonial but without any response......... Is anyone has another method to make that by streptozocin or we must to change rabbits by other laboratory animals?  

  • What can we do today about oak decline in mediterranean ecosystems?

    Periodic occurrences of decline and death of oaks over widespread areas have been recorded since 1900 in all the world. These outbreaks, variously named oak decline, oak dieback, or oak mortality, are caused by a complex interaction of environmental stresses and pests and given the name oak decline.
    Please describe the experience in your country.

    Kenny Ribbeck · Louisiana

    perhaps a management program focused on improving oak tree vigor through appropriate thinning of less vigorous stems via harvest for local use can improve all situations.  This allows the residual stems in the forest more space for growth while allowing locals to legally utilize the less vigorous stems for their needs.

  • Patrick Druggan added an answer in Cosmetics:
    Does cosmetic product development require clinical trial?

    My question does not just refer to their commercial use but also the R&D one… Let’s say I want to submit a Horizon 2020 project for a nano-functionalized cosmetic crème (not a medical grade one), would I still have to foresee clinical trials?
    Does anyone have any experience on the EU’s ethics guidelines on this point?

    Patrick Druggan · Synergy Health, Chorley, United Kingdom

    The recent recommendations for substantiating claims is that a clinical trial of Phase II type should be considered. This is not a regulatory requirement to my knowledge, but it is about good practice regarding primary end point, sample size and statistical planning and analysis. You are required to carry out a number of tests to show that the your cosmetic does not cause sensitisation et.c under the Cosmetic Directive 76/768/EEC, and you may have obligations associated with regulations around nano materials http://ec.europa.eu/consumers/sectors/cosmetics/cosmetic-products/nanomaterials/index_en.htm

  • Bruce Weaver added an answer in AMOS:
    Why do I obtain different results provided by SPSS and AMOS while doing the same thing?

    I did a factor analysis in SPSS on 5 variables (ML method, since this is the method that AMOS uses) and saved the factor scores using the regression method. This factor Y, correlated with variable X .77.

    Then, I do the same thing in AMOS, i.e. I create a factor (Y_a) with 5 indicators: all factor loadings are nicely the same as I got in the factor analysis in SPSS. So far so good.

    Then I correlate the factor Y_a in AMOS by drawing a covariance path to the variable X (since this is an observed variable I create a latent variable with X as single indicator without error). However, now the correlation between the Y_a and X is .94.

    How is this possible??

    Bruce Weaver · Lakehead University Thunder Bay Campus

    I suggest you post your question to the SPSS mailing list (see link below).

  • Where can I find the complete literature of Alberto Malatesta?
    I am working in marine deposits of Neogene in Canary Islands.
    Esther Martín González · Museo de la Naturaleza y el Hombre

    Dear Fabio, thanks you, I remenber you in february.

    Merry Chritsmans and Happy New Year.

    Esther

  • Marcel M. Lambrechts added an answer in Invention:
    Is forbidden knowledge a myth or a fact?

    For an example:

    "Suppressed Inventions & other Discoveries" - True Stories of Suppression By Jonathan Eisen

    To compile this book, editor Jonathan Eisen traveled the world in search of documented stories of scientific cover-ups, covert operations, and programs of deliberate misinformation, all designed to hide controversial inventions and discoveries, such as anti-gravity devices, limitless energy sources, results of cancer and AIDS research, and more. 40 photos. 30 illustrations. 

    Marcel M. Lambrechts · Centre d'Ecologie Fonctionnelle et Evolutive, Montpellier, France

    @Ljubomir: An emotionally neutral remark about UFO's.

    Why are there so many people that testified they observed UFO's (e.g. Discovery Channel, MUFON, GEIPAN...) versus the billions of dollars spend on research trying to discover life on another planet in our solar system?

  • What is the difference between potentiostatic polarization and ptentiondynamic polarization ?

    What is the difference between potentiostatic polarization and ptentiondynamic polarization in electrochemical corrosion tests?

    Yasser M. Abd-elrhman · Egypt-Japan University of Science and Technology

    I agree with Dr. Fahamsyah's answer.

  • Patrick Druggan added an answer in Agar:
    Why is there a greenish metallic sheen to E coli colonies in EMB agar?

    Why is there a greenish metallic sheen to E coli colonies in EMB agar?

    Patrick Druggan · Synergy Health, Chorley, United Kingdom

    Binsy,  Eosin Y and Methylene Blue precipitate out together to form a black pigment at low pH.  The greenish-gold metallic sheen is reputed to be due to the production of aldehydes, and is supposed to be specific for E.coli, but I have not found that to be the case as it tends to be related to the buffering capacity. I think that the effect is due to formation of a state of the pigment at low pH. The effect is also dependent on the quality of the Methylene Blue and possibly the relative molar concentration.

  • Is there a difference between velocities of photons in vacuum and velocity of fermions?

    The velocity of photons is isotropic property in vacuum, while in fermions it's affected by the uncertainty principle. How can we understand this conflict. If there is a velocity transformation between a fermion and a classical observer. Do you think it will be real or imaginary?

    and If there is a velocity transformation between a photon and a classical observer do you think it will be real or imaginary? with the reason please.

    Muhammad Aslam Baig · National Center for Physics, Quaid-i-Azam University, Islamabad

    Dear Stam Nicolis,

    thanks for explaining the process so beautifully. 

    Aslam

  • Is “ Ni(CO)4 is stable but Ni(CO)2Cl2 is not. On the other hand, Pt(CO)2 Cl2 is stable but Pt(CO)4 is generally unstable” true?

    “ Ni(CO)4 is stable but Ni(CO)2Cl2 is not. On the other hand, Pt(CO)2 Cl2 is stable but Pt(CO)4 is generally unstable”. Please give arguments.

    Metal Carbonyls

    Manohar Sehgal

    Anand Pratap Singh · Rajiv Gandhi Institute of Petroleum Technology

    It is bcz of 16 e- complexes of Pt are stable ,on the other hand that of Ni are unstable. the reason is that on going down the gr. CFSE increases by 40 - 50 % from first to second and by same amount from second to third row....

  • Seyyed Morteza Hoseini added an answer in Pyridines:
    How can I detect taurine amino acid in human and rat serum?

    deproteinization of plasma with acetonitrile then it dries

    pyridine and MSTFA is add and shake well for 30 sec

    MSTFA + 1% TMCS 

    pyridine is anhydrous

    incubation condition 

    temperature  60 c

    time 45 min

    Seyyed Morteza Hoseini · Gorgan University of Agricultural Sciences and Natural Resources

    Which method are you following? Give the citation. What is your problem with the assay?

  • JC Spender added an answer in Teaching:
    Could we teach anything else than subject matter anyway?

    Teaching is teaching something: that is mostly subject matter, a disciplinary content or whatever other content. The key word here is content. What else?
    Many people believe this. What’s your opinion?  

    JC Spender · Kozminski University

    Well, who knows how to answer that?  For me the notion of MY imagination - since I cannot know anything whatsoever about YOURS, a consequence of our total, utter inability to know as a another person might (no matter how capable we might be of Smithian empathy or sympathy) - presupposes our mind's acceptance of absence, of a vast unknown that is conjured into possibility by our sense of knowing something.  A sort of "Is that all there is?" response to knowing something.

    Now is that capability an entity?  Depends what you want the words to mean.  For me, no.  I see entity on the 'known' side of the line between knowing and imagining.

    But others might think - or know - different.

  • Douglas R. Daugherty added an answer in Curriculum:
    How can I research about effectiveness hidden curriculum ?

    Hi , I want research about effectiveness hidden curriculum on learning students in the high school .

    Douglas R. Daugherty · University of New Mexico

    Yes Lewis,

    I do know that book. I do not think that I am making myself clear. For example, here in the states we elect school board members. They run on a political, economic, philosophical "platform" that is then translated into school policy and curriculum choices, so when I use the term "these values" that is what I am refering to because we know them. Is the system in South Amerisca the same? 

    If it is or they is a way of clearly identifying thse values can you articulate them? I would be very interested due to my studying and research in Brazil and Poalo Freire's work.

    Thanks,

    Douglas

  • How can we measure the surface resistance of an anisotropic conductive surface?

    Imagine we have a surface in xy plane. there are some conductive lines in x direction which makes the surface conductive in x-direction but in y direction it is not conductive. For sure four point probe is useless here but how can we report sheet conductivity? 

    Resistivity is a tensor and the case you are describing is associated with an anisotropic resistivity tensor. Any measurement on the system under consideration should attempt to determine all independent components of this tensor. So, on account of the anisotropy, for instance the voltage measured in the y direction depends on the current measured in the x direction. Etc. Because in the absence of magnetic field (or better, when time-reversal symmetry is intact -- in the presence of magnetic filed, one has the Onsager relationship which can be fruitfully employed) the resistivity, of conductivity, tensor is symmetric so that in two dimensions in general one needs at least three independent measurements to determine the three independent components of this tensor. To suppress systematic errors in the measurement, one should carry out more than three independent measurements and determine the three independent components by means of for instance a least-squares fit. 

  • Ali Ibrahim Al-Mosawi asked a question in Tax:
    Creativity between neglect and belligerent ?

    Tax paid by the creators in many countries is negligence and whether the case of high exposure creative creativity to fight?

  • Ugur Kezik added an answer in Water Harvest:
    Does anybody have any experience or knowledge about quality of water harvested from air?

    I have harvested water from air and measured by YSI device some water quality parameters (pH, TDS, DO and Salinity etc.) under the home condition. At the 20.1°C temperature, pH=7.26, TDS= 88.40 ppm, Salinity=0.06 ppb, DO=4.1 ppm like that.

    Air humidity is very important for semi-dry and dry ecosystem in terms of living organism especially for plants. So, by determining quality of water in the air may be we will open new gates in different ecosystem in terms of plant health.

    Ugur Kezik · Istanbul University

    Thank you very much  Dear Hevia and Molina for valuable study. Really its help me a lots. 

    Also Thank you so much Dear Saeid, if you don't mind, may you share your study with us?

  • Musa paradisiaca responds low in Tissue culture in Multiplication Stage. Any suggestion on growth regulators and its combination?

    Plant Tissue Culture

    Mustafa Cuce · Karadeniz Technical University

    Hi Palani Manasa,

    I don't have so much knowladge about the biological and physiological composition of Musa species. But ı can say, you can try zeatin concentration (0.25, 0.5, 1.0, 2.0 and 4.0 mg/L) with IBA concentration (0.1, 0.2 and 0.3 mg/L). If you dont have any good results you have to modify the medium ingredient especially amounts of Ca and Mg

  • Ali Ibrahim Al-Mosawi asked a question in Society:
    Intellectual persecution, past and present?

    In the past oppression practiced by superstitious people clung to in order to protect their interests but now practiced by people who have obtained a university degree by suspicious ways and goal is to prevent the persecution of the creators of the real take their place in society and in both cases it is society that is paying for the intellectual backwardness?

  • Bubba Nicholson added an answer in Schizophrenia:
    Could anyone give me some "hints" about the drug-induced PPI disruption? Does it model positive symptoms of schizophrenia or cognitive deficits?

    Thanks in advance!

    Bubba Nicholson · NicholsonScience.com

    Collect the grease from the skin of your nose with any food substrate (wraps and chewing gum work) and provide it to schizophrenics p.o.  

  • Javier Garcia-Monreal added an answer in Optics:
    Is there any effective method to unwrap the precise phase distribution from a single digital hologram?

    As far as I know, the optical phase unwrapping method with two or more wavelengths is a good choice. However, it is complicated and hard to operate.

    Javier Garcia-Monreal · University of Valencia

    If I would have to answer in a single word, the short answer is NO. But there are plenty of details.

    In a reconstructed phase the phase is wrapped in 2*pi. Two flat surfaces with sharp borders with depth giving 2*pi or 4*pi would be indistinguishable. No matter which the unwrapping algorithm (on the object) is. Information is limited. You cannot know how many turns a wheel has turned in 100 m.

    The only way is to brake the ambiguity with more information. Say that you use two wheel with different radii. Then for a given combination of position of the wheels, the number of posibilities is greatly reduced. This is the equivalent of using 2 wavelengths. The range without ambiguity depends on the relative difference of lambdas. Using many lambdas you can enormously increase the range. This is equivalent to the 3D digitizers which projects fringes with different periods and have meters of range with a very sub-mm accuracy.

    All above refers to a phase map (or a few ones with different lambdas). You could use other information. In the answers by Davood Khodadad he refers to a method using defocusing. This, implictly is using the fact that the holograms exhibit paralax. You have several views of the object (assuming the number of pixels in the hologram are significantly larger than in the imaged part of the object). This extra information could be used by itself for better unwrapping.

    Nevertheless I'm unaware of a method using just this information, without needing multi-lambda. This could be a good subject for reseach :-)

    By the way, if you have a continuous phase (no regions separated by steps from the rest), try any of the well known unwrapping algorithms, like Flynn (google "flynn unwrap" to find details and even code)

  • Maria Beatriz Bruxelas asked a question in Biosensors:
    Biosensors: cleaning the analite so the biosensor can be used again. If we are detecting a bacteria, is it absurd to use an antibiotic as a cleaner?

    It can't affect the immobilized antibodies.I thought of using Ag nanoparticles, but this may clutter the device by adsobing to the walls.Is there other bactericidal solutions, something I could use to rinse the bacteria, without affecting the immobilized molecules?