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 Social Cognition:
    Should we hold people accountable for their mistakes?

    Dear RG friends,

    This is an important matter, for me as researcher and as human being. It is about errors and we know: "Errare humanum est, perseverare-diabolicum".

    Human errors and the adverse events which may follow, are problems of psychology, systems thinking, behavioral sciences and engineering (in technical systems). Understanding, predicting, and modulating human performance in any complex setting requires a detailed understanding of both the setting and the factors that influence performance. The social cognition research on cycles of accountability clearly captures the complexity of the effects and demonstrates the naïveté of the belief that improving society only requires holding others accountable.

    The “culture of blame” never worked. Why don't people just follow the rules, legislation, procedures?

    My starting point in formulating this question was occupational and system safety, but I would like to have your (expert or personal non expert opinions) in a general sense of human accountability in various fields, activities and situations?

    + 1 more attachment

    Roland Iosif Moraru

    Good point Subhash,

    To relate the error admittance to self-respect. We can not wait for respect if we do not respect ourselves in the first place.

  • Andre Patrick Arrigo added an answer in Literature Studies:
    Article recommendations for ROS-mediated regulation of transcriptional factors?

    I've been digging through piles and piles of literature for studies of ROS mediated control of signaling cascades - does anyone have any good article suggestions?   (feel free to toot your own horn here!)

    There is a surprisingly large amount of poor or confusing info out there - I'm trying to speed my search and not get distracted by misleading studies 

    Andre Patrick Arrigo

    You can check a paper I wrote

    Free Radical Biology & Medicine, Vol. 27, Nos. 9/10, pp. 936 –944, 1999
    Can be down loaded from my page

    Andre Patrick Arrigo

  • H. Jimenez added an answer in Amphipods:
    Can anyone identify these amphipods?

    Collected from British Columbia (Canada) central coast in August. Preserved in ethanol. Need ID to genus, but not sure if that is possible via photos. Thanks in advance.

    + 4 more attachments

    H. Jimenez

    Could be a a Hyalellidae like Hyalella azteca, which is a species complex. There is a good description on The Light and Smith Manual

  • Eugene F Kislyakov added an answer in Cognitive Systems:
    Is Chalmers' so-called "hard problem" in consciousness real?

    In his 2014 book "Consciousness and the Brain: Deciphering How the Brain Codes Our Thoughts" Stanislas Dehaene wrote "Chalmers, a philosopher of the University of Arizona, is famous for introducing a distinction between the easy and the hard problems. The easy problem of consciousness, he argues, consists in explaining the many functions of the brain: how do we recognize a face, a word, or a landscape? How do we extract information form the senses and use it to guide our behavior? How do we generate sentences to describe what we feel?

    “Although all these questions are associated with consciousness,” Chalmers argues, “they all concern the objective mechanisms of the cognitive system, and consequently, we have every reason to expect that continued work in cognitive psychology and neuroscience will answer them. By contrast the hard problem is the “question of how physical processes in the brain give rise to subjective experience … the way things feel for the subject. When we see for example, we experience visual sensations, such as that of vivid blue. Or think of the ineffable sound of a distant oboe, the agony of an intense pain, the sparkle of happiness or the meditative quality of a moment lost in thought … It is these phenomena that poses the real mystery of the mind”."

    Stanislas Dehaene's opinion is "that Chalmers swapped the labels: it is the “easy” problem that is hard, while the “hard” problem just seems hard because it engages ill-defined intuitions. Once our intuition is educated by cognitive neuroscience and computer simulations, Chalmers’ “hard problem” will evaporate".

    Personally, I agree with Stanislas Dehaene's opinion.

    Eugene F Kislyakov

    I don't know such idealist permises, Alfredo.

  • Paul Howard Riley added an answer in Turbine:
    Does anyone know any references on the efficiency trade off in very low volume turbo-generators?

    Very low volume turbines (< 10 L/s) running on air have low efficiencies. I want a curve that shows typical efficiency versus volume flow rate so I can make some trade offs. I know that efficiency depends on type of turbine, axial, radial, impulse reaction etc. I just need a simple graph for initial trade-off studies to put me in the right ball-park before the heavy analysis.

    Paul Howard Riley

    Thanks Geoff, but I am after very low flow rates, where the losses in boundary layer dominate. As flow rates drop losses increase significantly. If I read your image correctly, this is just a standard turbine map?



  • Steen Gimsing added an answer in Presbycusis:
    Anyone familiar with unacceptability of frequency lowering hearing aids in clinical setup ?

    Though presbycusis is the most common type of hearing loss, frequency lowering hearing aids are very rarely used. What are the reason behind this?

    Steen Gimsing

    When hearing dropped it felt the fullness in the ear. The ear canal was not obstructed by anything. So the hearing aid did remove the feeling of fullness.

  • Idris Akyuz added an answer in Thermal Evaporation:
    Do you have any suggestions (evaporation current, boat type, etc.) on the thermal evaporation of Zn and Sn metals ?

    Do you have any suggestions on the thermal evaporation of Zn and Sn metals? (evaporation current, boat type, etc.)

    Idris Akyuz

    ok. I will try...thank you...

  • Durgesh Verma added an answer in Polygala:
    Can anyone help me in identifying this plant?

    to me looks like member of fabaceae. Earlier i was thinking, it is some sp. of Polygala as flowers are similar looking.

    It is herb of about 30-40 cm height. Originally collected from meghalaya, north east India. It flowers in july- august

    + 1 more attachment

    Durgesh Verma

    No Arvind ji its not Milletia, it is herbaceous plant. Milletia is a tree species. Any ways thanks for suggestions.

  • Romuald Jagodzinski asked a question in Environmental Law:
    Any suggestions on the doctrine (interpretation, meaning) of 'effective, dissuasive and proportionate' sanctions in implementation of EU directives?

    I am researching the topic of implementation of European directives on workers' information and consultation (specifically European Works Councils) where I am looking at enforcement frameworks and their implementation. The EWC directive 2009/38 stipulates that Member States need to ensure that there are sanctions in place which are 'effective, dissuasive and proportionate'. I have gathered some material on the concrete meaning of these terms, but am looking for more tips on how to concretise these abstract notions. I have been looking at general legal literature, environmental law (where some specific sanctions are applied, like restitutio ad integrum, immediate stopage of a breach), but so far less into the EUCJ jurisprudence (I intend to do that later).

    Any ideas on the line of argument, tips, interesting sources or official EU documents would be very helpful.

  • Natalia Gorlatova added an answer in Viral Infection:
    What is the true method to quantify the cleaved protein bands in Western blot?

    I have been working on a protein which is get cleaved at its c-terminal in response to a viral infection. Whenever, I see my western blots, I can see partial or complete cleavage with two bands. But, I am very confused regarding the quantification of the protein (cleaved ones). Should I consider both bands or should I consider only the band at molecular weight of the normal protein? The purpose of the quantification is to see change in the expression of protein at polypeptide level. Let me know, if any other information required.

    Best Regards

    Natalia Gorlatova

    It is not clear from the description what is the goal of your experiment. Do you study the expression of specific cell protein upon viral infection or you suspect that occasional  viral infection of culture occurred during protein induction so the protein of interest is cleaved? I would check the specificity of your primary antibodies with serially diluted purified  target protein (of course if it available). In my experience  an observation of  two bands on WB in control untreated cell lysate may indicate on non-specific protein recognition by used antibodies. If used antibodies are specific to target protein and the second band belongs to cleaved target protein you should add protease inhibitors to the extraction buffer. There are commercial Protease Inhibitors cocktails from Clontech, Sigma Aldrich etc which work pretty well suppression of different classes of cell proteases...

  • Tapan Chatterji added an answer in Entropy:
    How could we separately calculate magnetic and lattice entropy for a magneto-structural transition (i.e. magnetic and structure are coupled)?

    All researchers. How could we separately calculate magnetic and lattice entropy for a magneto-structural transition (i.e. magnetic and structure are coupled)?

    Tapan Chatterji

    If there is no clear manetic phase transition then the magnetic contribution will come from the short-range magnetic order. If the system is low dimensional then there are analytic expressions of the magnetic specific heat (Onsager, Boner-Fischer etc.). You can try to ft those if the dimensionality of your system is known. But I am afraid that a broad hump like structure on top of lattice contribution will be more difficult to tackel by least squar fit. But you can try.

  • Shahrukh Khan asked a question in Periodontal Diseases:
    Are there any papers on Electronic cigarettes and Periodontal disease?

    I m looking for studies relating E smoking and periodontal disease.

  • Mahmoud Melhem asked a question in Social Networks:
    What is the first Academic social network?

    I need a brief history about the emergence of Academic Social Network

  • Philippe Bouaziz added an answer in Tissue Engineering:
    What is possible explanation for this observation?

    After Electrospinning of PCL Nanofibers and Aminolysis via Ethylendiamine treatment and N2  Plasma treatment we have cultured Smooth muscle cells on these scaffold. in SEM images below we see fractures between cell-nanofiber interfaces. we have done the same with HUVECs and nothing like these fractures were observed. 

    + 1 more attachment

    Philippe Bouaziz

    Hi, what you observed is due to the washing processed during the fixation try using a more biological fixation process methanol 2 min -20°c and then heat-freeze your simple.



  • Charis Ghartey added an answer in Qualitative Research:
    How can I provide a justification of my topic research?
    Should I search for any other people who have undertaken the same and/or similar research as mine?
    Charis Ghartey

    very useful

  • Elham Rahmani added an answer in Data Visualization:
    What are the best tools to use with R Shiny, D3.js or D3Plus for data visualization and manipulation?

    I am going to use data production tools for data visualization and manipulation. Do you know which tools are more applicable between R Shiny, D3.js and D3Plus? Thank you very much in advance.

    Elham Rahmani

    woow... great links. Thank you very much Andreas :)

  • Bundit Boonyarit asked a question in Amber:
    I need to run MD with Amber, How can I start?

    I have complex (ligand + protein) from docking result and I need to run MD with amber, but I'm not sure in procedure. How can I start to use amber or Do you have some tutorial in ligand-protein MD, Please suggest to me.


  • Astor Mignone added an answer in Hydrophobic Interaction Chromatography:
    Can you help me with my hydrophobic interaction chromatography setup?


    I am purifying my protein without any tag. The first step of purification is ion exchange chromatography and the second step is hydrophobic interaction chromatography. I was wondering if I need to buffer exchange my protein before the second step, since the concentration of NaCl into my sample will be 1M at the end of the chromatography. Otherwise, can I leave the NaCl into the sample and only add 1M Ammonium Sulfate salt to the sample before hydrophobic interaction chromatography? 

    Thank you for your help, 


    Astor Mignone

    You can try to change the elution salt of the ion exchange. instead using NaCl try ammonium sulfate and then, if neesary, add some more to the eluted material in order to ensure a proper binding to the HIC

  • Adela E. Croce added an answer in Chlorophyll a:
    How can I calculate chlorophyll a concentrations using a fluorometer?

    I just want calculate chlorophyll a and b concentrations using a fluorometer.

    I know the equation by using absorbance spectrometer, but I don't know using fluorometer. 

    According to the reference paper, there are excitation and emission peak, but I could not find calculation method.

    Adela E. Croce

    To obtain concentrations from fluorescence spectra, the fluorescence quantum efficiency as a function of wavelength of the emitting species has to be known, as well as the total absorbed light. Besides, unless you measure the total emitted light, a calibration of the geometrical distribution of the emitted light is required. The details may be read in a classical books on fluorescence like Principles of fluorescence spectroscopy by J.R.Lakowicz. 

    However, if small concentrations and emissions are measured, from the equation

     IF=  FIF I0 (1-10^(-eps.c.l))

    where FIF : fluorescence quantum efficiency at a given wavelength;,IF:  fluorescence intensity;I0: incident light intensity; eps: molar absorption coefficient at a given wavelength; c: molar concentration; l: optical path length of the cell,

     a lineal dependence of IFwith c may be obtained. In fact, for small c values  

     IF=  FIF I0 eps.c.l

    and you may construct a calibration curve from the spectra of solutions of known (low) concentrations. If a straight line through the origin is obtained, you have chosen the conditions rightly!

  • Iliana Leontari asked a question in LC-MS/MS:
    Can anyone help me with quantification of Pegylated-peptide with a molecular weight of 20.000Da with a triple quadropole lc-ms/ms?

    I want to analyze a peg-peptide with a molecular weight of 20.000Da by lc-ms/ms triple quadropole in mouse plasma.

    I know that there is a mass limitation with this instrument and furthermore i am interesting to reach a limiti of quantification of ng/mL

  • Touraj Farzani asked a question in TA Cloning:
    Is it true that the DNA purification kits have the potential of destroying the A tail of PCR products created by the Taq polymerase enzyme?

    I am going to do cloning by using the TA cloning kit.I am afraid that purification of the PCR products by DNA purification kit will destroy the A tail and my reaction fails.Is it possible?Thanks in advance.

  • Mohammad zakaria Masoud added an answer in Wireshark:
    What is the best opensource tool to capture wifi traffic in montor mode ?

    in my setup host A is connected to an AP and i am capturing packets on host B, I am currently using Wireshark, (the channel and SSID are fixed) I am observing a packet drop for data packets of around 50% on  (by comparing packets captured on host A and the host B) i would like some help/suggestions to improve on the capture setup. also i have tried adding a capture filter (based on mac address and to only capture data packets)  in WireShark but the packet drop still exists.

    Mohammad zakaria Masoud

    try Aircrack-ng.

  • Salah Ouhamdouch added an answer in Climate Change Impacts:
    Does anyone know how to prove the impact of climate change on groundwater by using both hydro-geochemical and isotopic approaches?

    I would be grateful if someone help me to have a section dealing theme.
    thank you in advance.

    Salah Ouhamdouch


  • Mohamed El Naschie added an answer in Quantum Physics:
    Why has the classical electron radius generally been rejected in quantum physics?

    There is a very close and accurate agreement between the classical electron radius, alpha, the electron Compton wavelength and the Bohr radius. such that:

    re = alpha. lambdae /2pi = alpha2 a0

    Given the great accuracy ascribed to alpha in particular, this would suggest that the classical electron  radius is valid.  

    Mohamed El Naschie


  • Rudy Situmeang added an answer in IT Managment:
    How can I synthesize a FeOOH (Goethite) sample with high degree of Al substitution (near 30%)?

    We already managed to make a synthesis of FeOOH with some Al in the structure. However, although we have made a synthesis which should contain 30 mol % Al, the real amount in the final product was only 5 mol %.

    Rudy Situmeang

    Hi Daniel, in addition to previous answer, I agreed that [OH-] or pH, salt concentration, suspension concentration and temperature will affect the formation goethites and/or hematite and also the aluminum content in goethites. you can read Clays and Clay Minerals, Vol. 27, No. 3, pp. 195-200, 1979,  ; JOURNAL OF GEOPHYSICAL RESEARCH, VOL. 117, B02102, doi:10.1029/2011JB008605, 2012 and Magnetism And Magnetic Materials Hyperfine Interactions July 1990, Volume 54, Issue 1, pp 467-472.

  • Ibrahim Shnawa added an answer in Immune Response:
    How can I improve the penetration of DNA into the muscle?

    We want to analyze the immune response against a protein. Our approach is to make intra-muscular injections of a plasmid that encodes for the expression of the protein. (We do not have enough AAV to do this experiment and we do not have electric devices for proceeding to an additional electric choc after injection.)

    Ibrahim Shnawa

    Or you can use other known immuno- adjuvants.

  • Gordon Ade-ojo added an answer in Dialogical Self:
    Does anyone know of research that has combined Bakhtinian dialogic and self study methodologies?

    Does anyone know of research that has combined Bakhtinian dialogic and self study methodologies? OR of research that has employed a self study approach to explore the practice of infant teachers?

    Gordon Ade-ojo

    I am not aware of anything that directly responds to your question. Nonetheless, there are a couple of work I have come across which explores gthe bakhtinian argument and have sought to relate then to educational concepts which I think you might find useful.. See titles and links below:

    In Theory Bakhtin: Dialogism, Polyphony and Hroglossia


    This particular work explores Bakhtin and connectedness, which in my view is very useful for self study.

    The other piece of work is 
    Wegerif, R (2008) Dialogic or Dialectic? The significance of ontological
    assumptions in research on Educational Dialogue. British Educational Research
    Journal 34(3), 347-361.]   The link below


  • Laszlo Jicsinszky added an answer in Azides:
    How can I quantitatively determine organic azides?

    I have a azide capped PEG polymer grafted onto a silica surface and i need to determine the amount of azide groups for further radio labeling.

    Laszlo Jicsinszky

    IR spectroscopy, using ATR technology. Around 2110 cm-1.

    You can make a calibration curve with sodium azide and not azidated PEG/silica.

  • Luis Estrada-Flores added an answer in Nanocapsules:
    Which technique do you suggest to study release of Sorafenib from sorafenib loaded lipidic nanocapsules?

    Hi there. I have encapsulated Sorafenib in lipidic nanocapsules with size of  50 nm. I have planned to study drug release by Sink Conditions through using dialysis membrane (MWCO: 100kD) in "PBS-1% Tween 80" as medium. The problem is that approximately all the released sorafenib attaches on the membrane and does not enter to the medium. What do you suggest to solve this problem? Can I add something like blank lipidic nanocapsules into the medium to increase the mobility of the drug? Thanks a lot.

    Luis Estrada-Flores

    You may look for different dialysis membranes, perhaps sorafenib does not attach to all types of membranes. You may also change the pH of dissolution media as pH has an influence in the Surface charges of the membrane.

  • Pranjal Singh added an answer in FSI:
    How does parabolic velocity assumption affect the Blood flow FSI simulation?


    I've been trying to simulate pulsatile blood flow. I've assumed hypothetical artery dimensions for which womersely number is about 1-2. I'm not getting reasonable compliance phenomenon in the arterial wall. It acts as if it is rigid tube. Does this mean that although pulsatile flow assumption is valid, I can't get realistic wall shear and forces to obtain compliance phenomenon in elastic domain unless I use womersely profile (complicated UDF to be written)?


    Pranjal Singh

    Thank you Andrey.
    I'm considering a simple elastic tube model with laminar pulsatile blood flow.
    Mean Diameter: 2.5 mm Thickness: 0.3 mm
    Young Modulus: 3MPa Poission Ratio: 0.45

    I've obtained reasonable results for rigid tube simulation. It is just that instead of propagation of a pressure pulse through the tube, I'm getting compliance effect just at the inlet. The pressure pulse isn't propagating.

    I'm thinking that this maybe analogous to giving excitation to a string fixed at other end. The pulse is only generated if I shake the end rapid enough. So, maybe the velocity variation isn't that rapid and the artery wall easily comes back to original position without transmitting the wave

    So, more specifically, I want to know: Is it because of the parabolic assumption? If not, how do you make sure that the 'pulse propagation' phenomenon is captured?