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

  • Raghu Ram Achar added an answer in Azocasein:
    In the Protease assay, which substrate (Azocasein or casein) and method should be taken?

    I followed some literature concerning the protease assay but I am a little bit confused about what substrate should be taken for the assay. Yes, casein is cheaper than azocasein, but is there any differences among them. Both are universally accepted or not? Thanks in advance for your replies.

    Raghu Ram Achar · Sri Jayachamarajendra College of Engineering

    both are accepted..caseinolytic you check at 660nm and Azocasein degradation at 440nm..

    and you can also study action of your protease(s) on casein, azocasein and hemoglobin.. that will add to your data and interpretations on substrate specificity while characterizing the protein.. 

  • Omar Mayyas asked a question in FACTS:
    Please any information scientific or religious about detected discontinuity at depth 1257 km, that named of Abu Al-Qasim ( صلى الله عليه وسلم )?

    Facts a bout the detected of Abu Al- Qasim ( صلى الله عليه وسلم ) discontinuity.
    A- “Religion Fact“- Aerial distance from Al- Kaaba in Saudi Arabia and Al- Aqsa Mosque in Palestine, which is equal 1257 km is matching the depth of discovered Erath Discontinuity.
    B- Scientific Facts:
    - Density and P- wave velocity significantly increasing after penetration of this discontinuity.
    - Temperature and Pressure gradually are increasing with depth.
    - Displacement starts growing semi- constant from the moment of crossing discontinuity.
    - (σ- relationship between seismic velocities) begin a gradual decrease after penetration of this discontinuity.
    - Ed/Es begins to decrease initial from discontinuity surface towards with depth.
    - Attenuation of seismic waves (dB) almost disappears completely in the earth’s strata under this discontinuity and it is a new very little appearance will be at depth of 2700 km
    - Amplitude of liquid (km) and wave’s decrement (δ (dB/Hz^2.sec)) begin increase steadily from penetration this discontinuity.
    - Coefficient of seismic wave attenuation α (dB/Hz.km) begins gradually decrease up to discontinuity ,where begins quickly decrease as soon it’s values closed to zero under discontinuity that continue to very deep depth.
    9- Stiffness k (kg/s^2) gradually decreases up to discontinuity then disappears completely in the earth’s strata under this discontinuity and it is a new very little appearance will be at depth of 2700 km.
    - Stress (kg/m.sec) begins to increase up to this discontinuity then begins significantly and steadily increasingly with depth.
    - API and Barrels of crude oil per metric ton decrease from discontinuity with a depyh.
    - at a depth of ( 700 km ??? ) and almost disappear as crossing this discontinuity to a depth of 2700 km, where it appears again timidly after this depth.
    - Volumetric size of the earth layers V ( m^3 ) is generally decreases toward with the depth as the peak decreasing at the earth depth interval from 1700- 2700 km then to begin upwardly timidly clear.

  • Samer Ismail added an answer in Mutation Screening:
    What is a suitable method for screening for mutations?

    We sequence patients DNA in order to detect the different mutations associated with the disorders; if it is simple gene with few exons and small number of patients then it is feasible to use either capillary or next generation sequencing, but if we have a complicated gene with many exons and many patients, it is more feasible to do mutation screening before sequencing. Because there are many mutation screening methods, the question now is, what is a suitable method for doing mutation screening which is accurate, fast and cheap?

    Samer Ismail · Taif University

    Thank you all for the answers.

    Dear Antony,

    it is long gene that contains 36 exons.

    the associated mutation differs from population to population

    the mutation is expected in more than 100 patients in a population that was not studied before; i.e. I need to screen all the exons in the 100 patients.

  • Deepak KUMAR Sahay added an answer in Soil:
    In which specific criteria one should provide pile-wall retaining structures ?

    There are lots of different type of retain structure available to retain soil. Pile-wall retaining wall is one of them. But it's expensive relative to other type of soil retaining system. So, in which case we should provide pile-wall retaining structures ? 

    Deepak KUMAR Sahay · Manav Rachna International University

    Some examples are :-

    1 ) in case of Metros / Cities this method is used for the construction of  Underground Metro Stations , Underpasses etc.

    2) In case of Industrial areas Matreial Handling system tunnels etc.

  • Hanno Krieger added an answer in Writing:
    Does being strong in writing in a first language corellates with the probability of being strong in writing in a second language?

    I am just wondering if ESL learners who write well in their first language will be able to write in the same quality in a second language. Are there any relationships between the writing quality in both languages?

    Hanno Krieger · retired from Justus-Liebig-Universität Gießen

    Dear András,

    may be that we wouldn´t have had problems if we had learned grammer later on or in my first native language. But I´ve no chance to make a new experience, im no more a young pupil. Today I prefer for children the talk and write techniques.

  • James R Knaub added an answer in P Value:
    Can Scientific research exist without p-values?

    Many people panic after spending months collecting data, analyzing ... only to find out that the hypothesis they are testing does not correspond to a significant p-value (e.g. p<0.05). Some times is makes you wonder, what the scientific community would be without this "thing" called the p-value. It brings happiness when one finds p<0.05 and frustration, otherwise (p>0.05). Surely, p>0.05 is not the end of the world, or is it? 

    James R Knaub · Energy Information Administration

    Jimmy -

    You are correct. A p-value is far overused, and in particular, the level set for a 'decision' should be different based upon sample size. A p-value is a function of sample size, and needs to be supplemented by a power analysis or some other sensitivity analysis. A single, isolated p-value is not very meaningful.

    Whenever you can use a confidence interval instead, that would generally be preferable as being more informative and practical.

    Unfortunately, many want to see p-values reported, not understanding that this is actually widely used bad practice.

    Cheers -Jim 

  • V. R. R. Medicherla added an answer in XPS:
    How much powder sample is required for XPS analysis?

    I am  going to characterize

    powder sample by using XPS

    V. R. R. Medicherla · Siksha O Anusandhan University

    Powder samples are not good for XPS analysis. If you make a pellet out of the powder and sinter it, it will work better. Powder particles are covered with adsorbed contaminants like carbon, oxygen etc. When it is in the form of pellet, you can remove contamination by scrapping the surface in UHV. Powder as such can not be cleaned in-situ. In any case, many people carry out XPS studies on powder samples. XPS signals are influenced by contamination. Your interpretation may be wrong if XPS is taken on powder as it is. If you have no option than doing on the powder, for usual XPS(no-monchromatic), X-ray spot size is about 5 to 10 mm, you should have enough powder to cover whole of this area. It cannot be mentioned in terms of mass, as it depends on the kind of sample you have.

  • Manish Gupta added an answer in Transfer Learning:
    What are the factors which facilitate transfer of learning?

    What are the factors which facilitate transfer of learning?

    Manish Gupta · ICFAI Business School

    Academic engagement of course !

  • Cemile Sönmez added an answer in PHA:
    Is anyone familiar with PHA stimulation of PBMC ?

    I will do cell culture with specific patients PBMC. I isolated the PBMC and now will stimulate them with PHA as I want to see Th17 association with the disease. After stimulation I will take the supernatan and assess with cytokine ELISA. What must be the cell counts per well for 96 well plate, 24 well plate. What must be the concentration of PHA? And how long must be the stimulation? Is PHA solely enough for the stimulation for cytokine expression? Anybody have any suggestions.

    Cemile Sönmez · Public Health Agency

    Thank's Craig.  I will stimulate all the PMBC of patients to investigate cytokine profile after nonspesific stimulation but in parallel there will be PBMC of patients which will not be stimulated.  I am thinking to do a 100.000 cells per well of a 96 well plate or 1 million cells/well for a 24 well plate. In articles PHA is used 1-5 microgram/ml. I will stimulate 72 hours. After stimulation I will take the supernatan and use ELISA's for IL-23, IL-12/23P40, IL-17AF and IL-35 to investigate the relationship of Th17, Treg with the disease. Does the method sounds good?

  • Muzaffer Çetin asked a question in Ideas:
    Is there anyone who is interested in exchanging ideas on e-mentoring?

    is there anyone who is interested in exchanging ideas on e-mentoring?

  • Carlos Araújo Queiroz added an answer in Glycols:
    Can you suggest a method for ethylene glycol determination in sea water?

    LOQ it's about 0,05 ppm


    Carlos Araújo Queiroz · New University of Lisbon

    Also possibly useful is the following NIOSH protocol: National Institute for Occupational Safety and Health (NIOSH): Manual of Analytical Methods (NMAM®), 4th ed., 1994, Supplement Publication Nº 1, 15 May 1996, Method 5523: Glycols (by S.M. Pendergrass), 5 pp.; http://www.cdc.gov/niosh/docs/2003-154/pdfs/5523.pdf

  • Can we change isomers of one components in a plant by post harvesting process? what are max ranges?

    Sometimes we can change some components in plants by simple method in library or store instead of hard action in the farm. Is there any paper to describe these methods?

    Saeid Davazdahemami · Research Institute of Forests and Rangelands

    thanks a lot

  • Arjun Singh asked a question in I-V Measurements:
    Why the short circuit current calculated from EQE measurement is different than Jsc from I-V measurement? Could it be corrected?

     I have calculated Jsc from EQE measurement which is almost 1mA/cm2 less than normal Jsc measured from  solar cell I-V data. Could anyone help to correct it. I will be very thankful. 

  • Is there a specific reference or guideline that we can refer to for the theory/methodology behind setting significance levels other than 0.05?

    Generally, the significance level used to detect statistical significance is set at 0.05. However, for investigations involving much larger samples, a very small difference can yield significance levels that mislead us to think that these values are statistically significant. Therefore, some studies set a much more strict (conservative) significance levels for their analysis.

    1. Is there a specific reference or guideline that we can refer to for the theory/methodology behind these strict, conservative significance levels?

    2. Can this new, strict significance level be applied to all statistical analyses in a given study or would we have to re-designate a significance level for each analytic method used?

    James R Knaub · Energy Information Administration

    Ye-Sle Shin -

    The problem is that a single p-value is a function of sample size and is not very meaningful on its own. A power analysis or other sensitivity analysis is needed in each case. Some perform power analyses to pick a test, but what I mean here is to basically compare, for the experiment made, two hypotheses, to see which is relatively more preferable, such that the null and alternative hypotheses are analogous to the two ends of a confidence interval.

    Sequential hypotheses do this by testing until you decide between two simple hypotheses.

    Whenever you can use a confidence interval instead, however, that is generally much more practical, interpretable, and useful.

    Setting a level of 0.5 is actually a bad habit, arrived at collectively. It really should be changed based on your sample size, as you indicated. A quick answer to your question would be that a power analysis could be used to adjust it, based on your sample size each time.

    The letter at the attached link discusses this problem.

    Cheers - Jim 

  • Baraka Maiseli added an answer in MATLAB:
    Is anyone familiar with extracting image from avi video?

    I've used some Matlab codes for image extracting from geovision camera (.avi video) but I faced this error ("The file requires the following codec(s) to be installed on your system:GMP4"). I cannot solve this problem after installing GMP4 codec!!! I can play video with some players like windows media player. does any one know how can I do it.

    Baraka Maiseli · University of Dar es Salaam

    I managed to use the code posted by Arvind Kumar and extracted automatically about 6000 frames from a .avi video (using matlab R2014a). The code is attached with this message;  just edit the third line to include your file.

  • Mohan Lal added an answer in Dental Science:
    How can vertical integration be applied in teaching of preclinical dental students?

    Vertical integration is combining knowledge of basic medical/ dental sciences with clinical sciences. Dental students go to clinics in 3rd year of their education. How can clinical knowledge be imparted to preclinical dental students?

    Mohan Lal · Government Medical College Amritsar

    In our institution, Integrated teaching is not for graduate or postgraduate ,but we have integrated teaching ,in which teacher from various department according to the topic specific present their presentation, and after this question answer session is arranged to clarify the query of the other faculty staff members and Postgraduates students. Topics are chosen according to their importance in the current situation.But In thinking integrated teaching require a lot of efforts to evaluate the level of knowledge and skills of the students.For this effective planning,implementation and evaluation should be planned.

  • Hojat Rezaei added an answer in Chronic Leukemia:
    What is the best method for laboratory examination of ALL and CML? I means ABL-BCR Fusion?

    I can't get good bands in electrophoresis in nested-PCR, how can I take it?

    Hojat Rezaei · University of Isfahan

    oh, yes im working base Cross et al method but i have not original article and i have a problem in primers A-B and C-D. so i cant get band in A-B primers and i get band by C-D primers in normal similar patient but cant understand it.

    do u have original article or can help me? 

  • Ravindra Verma added an answer in Hydrology:
    How can I plot the wilcox diagram in SAR irrigation water quality?
    Can I use Exel or other else that free program? How much it hard to be used? Thank you very much.
    Ravindra Verma · NITIE-National Institute of Industrial Engineering

    Dear Sir,
    please send me link of wilcox diagram software


  • How to start learning CFD?
    I am proficient enough in programming using C and MATLAB but when I open any CFD text book, all i find is calculus. I want to slowly learn writing my own code but the books don't give any idea how to proceed with those hifi mathematical schemes.
    Chandra Sekhar · Rutgers, The State University of New Jersey


    I cant add anything new to what everyone has said, but I want to put forth an idea (this is not related to the asked question). I am a CFD enthusiast and I would very much like to pursue it as a hobby first and then hopefully a career later. I am currently developing a GPU code for 3d navier stokes flow (I think gpu are the future in CFD:) ). I would like to know if anyone is interested in collaborating. 

    After some research I have realized that CFD is not difficult but painstakingly elaborate and vast,  so would be awesome if anyone would like to collaborate.if interested please reply to this message or email me at chandrasekhar971@gmail.com. 


  • Which modern language uses a partially syllabic writing system?

    Please if you have any idea about the syllabic writing system, share your knowledge
    Thank you in advance

    Mohammad Hamad Al-khresheh · Al-Isra University

    Dear Ella, I am unsure whether Hebrew uses a partially syllabic writing system.

  • Are there any papers related to HPTLC on both in vivo and in vitro plant materials simultaneously?

    I worked on two related plants. I want to identify that both plants contain the same secondary metabolites by taking a single metabolites.

    Yuan-Yeu Yau · Northeastern State University

    Please see the attached paper. They also involved the use of HPTLC for the analysis of the in vivo and in vitro plant materials.

    "Subcellular Localization and Quantification of Camptothecin in Different Plant Parts of Chonemorpha Fragrans"

    [The objective of the present study was to reveal the accumulation of the alkaloid camptothecin (CPT) in both in vitro as well as in vivo plant material of C. fragrans.]

  • Sergei A. Ostroumov asked a question in Altmetrics:
    Which ecology publications have big impact according to criteria used in altmetrics (including mentions of the articles from all across the Web)?

    Altmetrics is a modern way of assessing impact of scholarly publications.

  • Devendra Pratap Singh added an answer in TNF:
    Is anyone familiar with TNF alpha and NSAIDS enteropathy?

    There is a strong link between tnf alpha and mitochondrial dysfunction. But to what extent would anti tnf therapy be useful in nsaid enteropathy as tnf levels are also required for knowing the state of the disease condition?

    Devendra Pratap Singh · B.V. Patel Pharmaceutical Education & Research Development (PERD) Centre

    Dear Sir

    By NSAID enteropathy i maean damage to small intestine only. NSAIDs are prescribed for symptomatic relief in RA patients and it has been reported that NSAID alone or in combination with PPIs damage intestine.

    Anti TNF agents are highly effective against NSAID enteropathic damage in clinical studies so there has to be some relationship (Pls see attachment) . Please throw some light  in this regard.

  • Jung Dayoon added an answer in Purkinje Cells:
    Does anyone know how to maintain whole-cell condition with the antibody in your glass pipette?

    Hi, nowadays i am trying to apply channel antibody into cerebellar Purkinje cell.

    However, every time I tried, whole cell condition went bad in 10 minutes (even initial condition was quite good).

    Cerebellar Purkinje cell, especially its dendrites, is rather larger than other cells, so I should wait at least 20 minutes until the internal solution spread out enough.

    I can see the common problems in Rs configuration; decreasing holding current, increasing leak current by time.

    If you know any know-how, please let me know

    thank you 

    Jung Dayoon · Seoul National University

    Yes, everytime I changed internal solution from antibody internal to just normal K+ internal, cell's condition maintained normally. That happened in a same slice.

  • Ashish Kumar asked a question in C:
    Hi, I'm solving energy equation in Fluent 14.0 I want to extract the value the temperature gradient at every iteration.. Is there any way out.?

    Here is the code what I'm trying but it is giving error... (Asses Violation)
    #include "udf.h"
    #include "mem.h"
    # include <stdio.h>
    #define filename "temperature23.out"


    Domain *d;
    Thread *t;
    cell_t c;

    FILE *temp_file;
    real p;
    d = Get_Domain(3);

    temp_file = fopen(filename, "w");
    p= NV_MAG(C_T_G(c,t)[0]);
    C_UDMI(c,t,0) = p;
    fprintf(temp_file,"%f", p);


  • Rayehe Rahmanian asked a question in Perfectionism:
    Which statistical analysis do i use for data analysis of a questionnaire?

    i am writing a research proposal and i have to give a proposal data analysis.

    my research is about perfectionism, parenting style and academic achievement. and i am using two questionnaire( MPS and PAS ). but i am not sure which statistical analysis to use for my results.?

  • Gerro Prinsloo added an answer in Simulink:
    How can I generate a PWM signal using simulink?

    Actually I need to generate PWM signal using simulink, but if I have the reference voltage in discrete form, I have some problems. It cannot detect the values which are very small. I have attached the model pic. -Thanks and regards, Manoj.

    Gerro Prinsloo · Stellenbosch University

    Dear Sai

    We use this block for generating PWM signals in solar tracking applications and sun tracker systems where the DC motor and actuator speed is controls the tracking speed in azimuth and elevation angles using Matlab code to track the sun position as the sun traverses the sky. In Simulink simulations the link to the PWM control block is:


    The Mathworks page also contains examples that you can look at.

    trust this helps



  • Sayed Zaheen Alam added an answer in Drought:
    What are the criterion to delineate the drought prone regions of India?

    There are different types of droughts. Along with rainfall what are the other criterions for the delineation of drought prone regions of India.

    Sayed Zaheen Alam · University of Delhi

    Kindly note down from my own teacher’s (Delhi School of Economics, D.U.) book Saroj K Pal,1998: India 50 years of Independence; 1947-1997 Status, Growth and Developemnt DROUGHT, B.R.Publication, New Delhi.

    Drought Indices in India:
    1. Aridity Indices
    2. Climate Soil Water Balance
    3. Index of Moisture and Computing (Potential Evapotranspiration by Thornthwaite’s Method)
    4. Computation of Actual Evapotranspiration
    5. Determinant of Water Deficit (Water Surplus and and Surface Runoff)
    6. The misture regime of climate
    7. Computation of potential Evapotranspiration by H.L.Penman’s Method


  • Abhishek Karwa added an answer in HFSS:
    Are there any companies that design microstrip patch antennae from HFSS?


    Abhishek Karwa · JIET Group of Institutions

    Sir i have fabricated the microstrip patch antenna for uwb range is it possible to get measured results from vna at your university.