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

  • Suman Maroju asked a question in Speaker Recognition:
    What are the techniques to differentiate between two signals?

    Signals can be of different types like

    Voice signals,

    Vibration signals,

    2d signals like picture signals,

    Now my question is how to differentiate between the signals, i.m how to say one signal are different from other.

    There are many techniques like that are used in face recognition, or speaker recognition. So what are the best techniques to difference between signals.

    I want to know the best methods irrespective of particular type of signal.

  • Erick Arguello asked a question in Computer Modeling:
    Which would be a good journal for submitting a review article on the computational modeling of Pain?

    Dear Researchers, I just finished an article on the strategies used in computational modeling of pain, from the single-cell level to the whole-model level. Do you know any Journal that would be interested on that topic?

  • Archana Prakash added an answer in Earthquake:
    How do you measure an earthquake without the Richter scale?

    The earthquake of Shilong, which took place in 1897, was measured magnitude 8.2 on the Richter scale. If the Richter scale was not invented at that time, how did they measure the magnitude of the earthquake that took place? Question asked in an interview. People who have an idea please reply.

    Archana Prakash · National Institute of Oceanography

    Thank you to both of you! Its useful.

  • Kona Madhavinadha Prasad asked a question in Naphthols:
    How to make standard curve of alpha/beta-naphthol for estimating esterase enzyme activity ?

    Please suggest How to dissolve the naphthol in buffer for making standard curve ? 

  • Saima Mushtaq added an answer in Indexing:
    Is there any wrong in XRD Indexing in following figure ?

    In my manuscript, one of the reviewer comment: "XRD indexing is wrong in below figure"? please suggest, where is my fault. Thank You.

  • Michael Shinder added an answer in Self-Motion:
    Cerebellar impairment caused deficits in hippocampal place cells, but why?

    There is recent evidence suggesting that cerebellar function is necessary for place cells to form place fields (their spatial sensitivity) in the dark when a landmark is not present. However, it is not fully clear why. In the dark when a landmark was available, the hippocampus was able to form place fields, suggesting that self-motion could be used if it could be referenced to the landmark. This seems counter-intuitive to a pure self-motion processing deficit, and suggests that the cerebellum may not only be simply processing sensorimotor information, but may be vital in registering self-motion information to an internal model of a fixed environmental reference (in this case, displacement in the environment could be computed by using a model of gravity and sensory input about self-movement, which may be disrupted by cerebellar damage). Without normal cerebellar function, the same self-motion information can still be turned into displacement relative to a fixed landmark, even in the dark. This would then imply that the conversion of sensory information about translation through space can be converted into displacement without the cerebellum. Why then would the hippocampus be so dependent upon the cerebellum without a fixed landmark? Why could the navigation pathways not just used as an arbitrary starting location of the fixed reference for path integration purposes?

    The problem of self-localizing without a landmark could mean that there are two different processes by which self-motion is computed (landmark-based and un-cued). It could also mean that without a landmark there is no way for error correction to occur, and errors accumulate and deteriorate the spatial alignment of the place cell firing with the environment. In this possibility, the cerebellum acts to correct spatial errors in the dark without a landmark - suggesting a possible role in working memory for the reference location (internal landmark location) used in the correction, along with a possible role in sensory processing for displacement.

    Is anyone aware of evidence that might better distinguish the role of the cerebellum in hippocampal place field responses?

    Michael Shinder · Baylor College of Medicine

    The possibility of further studies sound very hopeful and intriguing. Vladimir, evaluating the hippocampal-cerebellar connection during spatial navigation in freely moving mice seems to be a good starting point. Laure, might I ask what you mean by goal-directed behavior and what motivated your thinking in using goal-directed behavior? In trying to think of experiments that might better elucidate the function of the connection, I have been driven to reduce and simplify the tasks. In this way I think that the constraints will better allow me to identify what internal variables are critical to the function of this pathway. Goal directed behavior seems to be a different perspective, attempting to challenge the system and define its function by identifying points of failure. Am I correct in this? In which case, it would seem the two types of experiments could be complimentary and provide different understandings about how the same system works.

  • Manu Singla asked a question in Brain Imaging:
    Can anyone help me with how to get 2-D slices from 3-D volume of brain MR Images?

    Hi, I want to perform segmentation operation on Brain images using matlab.

    I have 3-D volume of brain MR Images and want to convert them into single 2D slices in order to apply segmentation algorithms on that.

  • Jorge Gonzalez Gonzalez added an answer in Chaos:
    What are the famous chemical reactions yielding chaos?

    In chaos literature, it is well-known that Belousov–Zhabotinsky reaction or BZ reaction is a famous chemical reaction exhibiting chaotic behaviour. Belousov-Zhabotinsky reaction provides an interesting chemical model of nonequilibrium biological phenomena, and the mathematical models of the BZ reactions themselves are of theoretical interest as they exhibit chaos under some operating conditions. Are there other famous chemical reactions yielding chaos? Your views are welcome on this topic! Thank you..

    Jorge Gonzalez Gonzalez · Independent Researcher

    The oxidation of NADH by O2 catalyzed by horseradish peroxidase: http://www.powershow.com/view1/165b65-ZDc1Z/Chemical_Sensing_and_Biological_Networks_powerpoint_ppt_presentation

    The Briggs-Rauscher Reaction: http://ocw.mit.edu/high-school/chemistry/demonstrations/videos/briggs-rauscher-reaction/

    The BZ reaction you cited: https://www.youtube.com/watch?v=3JAqrRnKFHo

    The Bray-Liebhafsky reaction: https://www.youtube.com/watch?v=fT0hhWlAbb4


  • Which methodology is the best for bacterial capsule staining?

    Fundemantal Microbiology Laboratory

    Kaushik Bhattacharjee · North Eastern Hill University

    The method described by Dr. Shraddha is better.

  • Lokesh Ravi asked a question in Magnesium:
    What is the UV range for Magnesium nanoparticle ?

    I have been searching for a while now., but i couldnt get any information on the spectrum range for Magnesium nanoparticles.

    For.eg., Silve Nanoparticle falls between 400 to 500nm in UV spectrum,

                  Similarly is there any range for Magnesium Nanoparticle?

    Thanks in advance

  • How should I use rabbit polyclonal antibody to 6XHis tag (Sigma), conjugated to HRP for immunohistochemistry?

    I'm trying to stain for a 6xHis-tagged protein which accumulated in skin tissue in mice. I want to use mouse polyclonal antibody to 6XHis tag (Sigma), conjugated to HRP (one step procedure) and then DAB as antibody substrate in immuno-histochemistry. Does anybody know a proper protocol for applying this antibody in immunohistochemistry (on cryo-sections)? 



    Prasanta K Ray · Centre for Applied Science and Technology (CAST)

    Follow any published method!

  • Sivan Kober added an answer in Hysteresis:
    Can I create a viscous aqueous solution with no hysteresis with temperature change (heating and cooling)?

    So far the thickeners I have worked with have caused a permanent change in texture and viscosity and I am trying to avoid it. My usual working temperature is 15-35 deg. celsius and I am doing tests after heating and cooling (50 and 0 deg celsius, respectively).

    Sivan Kober · biofeed

    I am working with CMC and xanathan and I am trying to wisely select my next candidate.. time is no limit (can be days) but faster is better..

  • Erick Arguello added an answer in Oligodendrocytes:
    What's oligodendrocytes morphology in culture?

    I am culturing primary glial cells from mouse cortex. I have found several cells with a curious morphology. They have a round prespicent soma and a flat sheet-like soma with several holes within, in a lace-like manner. Can they be oligodendrocytes?

    Thanks in advance


    Erick Arguello · Simon Bolívar University

    Hi Francesco,

    There is a myelin/oligodendrocyte-specific protein, MOSP, which has been identified by using a monoclonal antibody on the surface of cultured oligodendrocytes (see: Journal of Neuroscience Research, Volume 28, Issue 4, pages 607–613, April 1991). Perhaps you need immunohistochemical approach to determine whether those cells you found are oligodendrocytes..

    Best regards!

  • Abhishek Mukherjee added an answer in Catalase:
    I want to do catalase assay using 60% H2O2 soln. as standard. plz suggest how to make a standard curve for catalase assay?

    One paper is submitted where catalase assay is done. but preparation for standard curve is not given.

    Abhishek Mukherjee · University of Burdwan

    check the paper

  • How do you define the length of a MD simulation for evaluating the mobility of protein side chains?

    A short MD simulation is often criticized by a referee, however, depending on the phenomenon we observe like in my case side chain mobility, what would be the best simulation time in explicit water for my system?

    I am supposed to evaluate the sampling time by looking at the convergence of a reaction coordinate. If this convergence is reached at 2ns, then is 10ns of simulation time ok?

    Naga Bhushana Rao Karampudi · IIT Kharagpur

    Side chains undergo conformational changes, if your simulation time can allow the sampling of all possible conformations till some threshold (may be 90% ) or some other lower limit which you feel is enough. Then you can convince the reviewer that you have allowed the simulation to mimic real system's behaviour (provided the force field is apt for the system). This way you can evaluate the simulation time needed.

    You can use "bin" system to collect the sampling stats. But, once you reached a threshold (achieved relatively faster) it really needs a very long simulation time to sample that extra 10% of space. So do not try to sample all space.

  • NILESH KUMAR SHARMA asked a question in SDS-PAGE:
    What Should a proper ratio between Voltage and Current while running SDS-PAGE ?

    I running SDS-PAGE and I am facing a problem i.e. if I am setting voltage 100V then current is going to much higher like 400mA. and if I am going through current and setting it 35 mA then voltage is automatically going 7V. 

    Gel is taking too much time to run, approx 9 hr. 

    can anyone suggest me what should be the actual value of it, because at 400mA nothing is visual in Gel.

  • Michal Apollo added an answer in Himalaya:
    Can anyone help me with identify some himalayan plants (Miyar Valley, Western Himalaya, altitude 3850 meters)?

    Can anyone help me with identify some himalayan plants (Miyar Valley, Western Himalaya, altitude 3850 meters).
    Picture with the plants I have enclosed below.
    I will be obliged for any help,
    Michal Apollo

    Michal Apollo · Pedagogical University of Cracow

    Thank you all so much. I added bigger resolution. I am very obliged for all your help.
    Best wishes from Poland,
    Michal Apollo

  • Nandaki Nag asked a question in Membrane Potentials:
    Could you help to find principle to check mitochondrial membrane loss using TMRM?

    i did a mitochondrial membrane potential assay with TMRM. But here i have doubt regrading results because my control and drug treated sample showing me the same values..!!

  • Vikram Zaveri added an answer in General Relativity:
    What physically changes when a particle is elevated and gains gravitational potential energy?

    We frequently speak of an object having gained gravitational potential energy when work is done in lifting a mass from a lower elevation to a higher elevation. However, what exactly has physically changed? Where is this gravitational potential energy stored? When a photon propagates from a lower elevation to a higher elevation, we say that it has undergone a gravitational redshift. However, this is entirely due to the gravitational change in the rate of time. Local clocks at the two elevations are running at different rates of time giving the perception of a lower frequency at the higher elevation. The photon appears to have lost energy but there is no change in frequency if adjustments are made for the different clock rates. If an electron is perceived as a point particle with no internal structure, then it is impossible to assign any change in the internal energy of an electron at two different elevations. Therefore, where is gravitational potential energy stored when an electron or other particle is elevated?

    Vikram Zaveri · Independent Researcher

    John. As the planet in your example moves from apogee to perigee, its gravitational potential energy gets transformed into its kinetic energy and when it moves from perigee to apogee its kinetic energy gets transformed into its gravitational potential energy. Alternatively the planet motion can be described in terms of change in the frequencies of its constituent particles. The frequencies are lower at apogee and
    higher at perigee. So either you can describe the phenomenon in terms of energy or in terms of frequencies, but not both simultaneously. There is no need to bring in clocks and time except for some reference.

    Stephen Warren. Meaning and signifcance of energy is that it is a unifying factor of everything in the universe. Everything is reducible to energy. And another feature is that, a particular form of energy can be destroyed but as a whole, energy is indestructible.

  • Dimpi Paul asked a question in Nano:
    How does nanoparticle size depends upon the Refractive index of material?

    Want to know for different size of nano particle what changes can be observed in refractive index or how they depends?

  • how do you do an evacuation-repressurization cycle for hexane displacement to measure porosimetry?

    I'm trying to measure the porosity of some silk scaffolds I made.  From some papers I read, they did a hexane displacement method to measure the porosity.  Part of the methodology states that they did a quick evacuation-repressurization cycle to completely evacuate the pores from air and replace it with hexane.  Initially, I thought of using the vacuum oven.  However after reading the MSDS of hexane (toxic, flammable), I now have second thoughts of doing this.  Can anyone suggest an easy and safe way of performing an evacuation-repressurization cycle? Is just any vacuum pump compatible with this?

    Carlos Araújo Queiroz · New University of Lisbon

    Considering data for the boiling point of n-hexane at the low vacuum range (760 to 25 mm Hg), you have to deal with the fact that (liquid) n-hexane boils by approx. 121 mm Hg at 20 ºC (taken as room temperature). Cf. J. G. Speight (Ed.), "Lange's Handbook of Chemistry", 16th ed., 2005, McGraw-Hill (Table 2.37).

  • Arturo Sánchez González asked a question in Ferns:
    Reeves,T. 1979. A monograph of the fern genus Cheilanthes subgenus Physapteris (Adiantaceae)?

    Could someone assist me to get this reference please? Reeves,T. 1979. A monograph of the fern genus Cheilanthes subgenus Physapteris (Adiantaceae)?

  • How to order Cartosat-1 STEREO data through NRSC while it is not showing on their online order services ???

    Remote Sensing data acquisition

    Amol Pandurang Jarag · Shivaji University, Kolhapur

    Dear Sir,

    Please first fill the from and details information about your study region eg: latitude, longitude, path, row and date of acquisition etc. please see the attachment 

  • How can I solve in explicit form this PDE with the method of characteristics?

    I need to solve in explicit form the PDE of the depth of the current of fluid moving in a non uniform inclined channel under gravity effect. See the attached file.

    Sandro Longo · Università degli studi di Parma

    Dear Rogerio,

    the equation is intended expressed in non-dimensional form after choosing the proper length and time scales. An example of non-dimensional formulation of a similar equation is reported in the manuscript attached to my answer. Thank you.

  • Subhankar Maity added an answer in Polymerization:
    How to determine product is copolymer not a mixture between homopolymers?

    I did ring-opening polymerization to obtain Polymer A then copolymerization by ring-opening with monomer B to obtain copolymer A-co-B. 1H NMR showed both characteristic peak of Polymer A and Polymer B. However, I wonder how to clarified that it is copolymer not mixture of homopolymer.

  • Debabrat Sabat added an answer in Insect:
    What causes the coloration in insects?

    The metallic sheen color found in insects protect them from predators but how does this color gets selectively develops 

    Debabrat Sabat · National Institute of Technology Rourkela

    Thanks Peter!! So is their any nanostructures involved for these coloration...

  • How can humanoids be useful in helping the patients suffering from Autism?
    Some work has already taken place with humanoid development.
    Soroush Sadeghnejad · Amirkabir University of Technology

    Autism is a neurodevelopmental disorder characterized by impaired social interaction, verbal and non-verbal communication, and by restricted and repetitive behavior. Children affected by Autism Spectrum Disorder (ASD) show early impairment in Joint Attention and Imitation. Several researches focused on the use of robots during therapeutic sessions with impaired people. It is possible to categorize such applications into four dierent kinds: a) robot vs humans behavior comparison; b) child behaviors elicitation; c) active skills training; d) providing feedback on performances. In the first case, the behavior of the child during interactions with a humanoid robot is compared with his behavior in the same interaction performed with a human therapist: here the focus is on how the human characteristics in influence the interaction. In the behavior elicitation case, the humanoid robot stimulates a social reaction of the child: its presence, absence, and more in general, the quality of this response is helpful during the therapy assessment carried out by the therapists. The humanoid robot is also able to model, teach and practice a skill: in this case the aim is to facilitate the learning of such skill by the child and its eventual transfer in interactions with humans. At last, humanoid robots can provide feedbacks to the child about his current activity, to reinforce the learning. Also, the robot can help the therapist on achieving a more natural interaction, by providing information regarding the internal stimuli of the child and increasing in this way the individualized nature of the therapy. They all done by the features that a humanoid robot have in comparison to the robot's characteristics and features. It is like a human and if it has a funny look and appearance, it could help more the autism.

  • Michael Shinder added an answer in Volition:
    What exactly are the signal processing mechanisms performed by the parietal cortex during navigation?

    The parietal cortex has long been associated with navigation, but the specific function has been somewhat difficult to pin down. One theory is more sensory and holds that parietal neurons encode path or distance relative to various reference frames in the environment (landmarks, local vs global space, personal distance or path integration). Another theory is more movement oriented, and holds that the parietal cortex encodes the procedural parts of navigation - the volitional ability to move along the given path in a particular context, linking to the behavior and not the environment. It is possible the parietal cortex aligns both - ideothetic and allothetic spatial information? Is it put in register? However, I have yet to see strong evidence for this combination in navigation tasks. 

    Does anyone have an idea about what exactly are the signal processing mechanisms performed by the parietal cortex during navigation? 

    Michael Shinder · Baylor College of Medicine

    Thank you for the input. Most certainly we are not yet at the point at which we can point to a given parietal neuron and say that it's output equals some known function of a given set of inputs. Without this information we cannot determine how the parietal cortex is reducing the dimensional qualities of sensory information to form a more cognitive representation that would be informative for the process of spatial navigation. Further, in absence of establishing what information neurons are representing, we are yet further steps away from understanding the functional network transformations related specific navigational functions in a given behavioral context.

    However, I think there are a number of indications that hint at possible parietal functions coming from various different directions in neuroscience. It would seem strange from a broader perspective for the parietal cortex to do something so simple as to encode motion without having that be part of a larger, more extensive functional process. In the same vein, it is also counter intuitive to think that spatial navigation is completely encapsulated within the parietal (even if we are liberal in the cortical regions to which we apply the name). 

    We could suppose that the parietal cortex is intrinsically functionally adapt at creating a common reference to align multiple inputs (for example: being able to take and egocentric map of self-motion and an allocentric map of space, but you could imagine any two ordered sequences of information). This would allow one input to be evaluated in terms of the other (self-motion producing displacement through space establishes a change in location during navigation, or again more generally the parietal could allow comparison of one system of information in terms of another like in Luder's example above we could use verbal cues from language in an arbitrary alignment with visual cues in a given task where both visual and verbal cues carry information and the resulting combination must be assessed). 

    While this makes a pretty hypothesis, as has been noted, the parietal cortex is not some homogeneous region. There are a number of specialized subdivisions and many functional anatomical pathways that likely have very specific computational behaviors - like encoding rotation during spatial navigation. 

    I am curious and hopeful that further investigation into the information being represented and the transformations being performed both at the neuronal and network level will give us a better understanding of parietal function if we can tie the physiology to appropriately directed behaviors and environmental contexts. Yet, admittedly, I see a lot of endless possibilities here, and appreciate as much input and constraint as I can find.

  • What will be the best way to remove traces of crotonic acid present in the crotonaldehyde?

    Storing crotonaldehyde in refrigerator for few weeks produces traces of crotonic acid which poison the catalyst used for the reaction. I filtered through basic alumina but could not help.  Aqueous treatment is not suitable for my further reaction.

    Kachapur Arunkumar · Dr. Reddy's Laboratories

    Just go for bicarbonate washing before experiment to get rid of acid.

  • Krishnan Umachandran 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.

    Krishnan Umachandran · Professor

    What Makes Us Human is a short film being produced by the Electronic Arts Department at Missouri State University.