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
  • What are the disadvantages of the current system of copyright protection the most detrimental to the development of science?

    With which of them you had to face? Please share with us your experience.

    Behrouz Ahmadi-Nedushan · University of Yazd

    The disadvantage is that copyright laws prevent people from using protected materials without the copyright holder's permission and at times users can not afford to pay the high price.
    on the other hand, support of writers and other professionals and their rights means they get more incentive to create future works.

  • Ruby C Y Lin added an answer in KEGG:
    I have a gene sequence, how can I determine which pathway it might be related to?

    I have a sequence of a susceptibility gene and would like to blast it in KEGG or any other pathway database. How would one do that?

    Ruby C Y Lin · Asbestos Disease Research Institute, affiliated with University of Sydney

    It's best you blat the sequence in UCSC Genome Browser and find what it is. If you do know already, KEGG is a great way to find pathways. If you have commercial software e.g. MetaCore or Ingenuity, both are useful ways to find signalling pathways. Check Interactome as well. 

  • Filippo Salustri added an answer in eye health:
    What are some design principles to guide the design of visual displays to reduce eye strain?

    In designing educational software, I'm concerned about eye health.  What colors are best for backgrounds, and how can we optimize contrast and brightness?

  • Peng Dong added an answer in Coping:
    How do you prepare a TEM sample of organogel?

    I have tried to dip copper mash on the surface of the gel as indicated by some articles. But it was to thick to observe my material. how can i cope with that? THX

    Peng Dong · Sun Yat-Sen University

    I see. I will try the way you told me. Thank you, sir.

  • Peng Dong added an answer in Copper:
    How can I prepare a TEM sample of organogel?

    I have tried to dip copper mash on the surface of the gel as indicated by some articles. But it was to thick to observe my material. how can i cope with that? THX

    Peng Dong · Sun Yat-Sen University

    Thanks for your advice. I will try it.

  • Filippo Salustri added an answer in Philosophy:
    Has science lost its liberating power?
    After the European Middle Ages, science was one of the liberating forces. But now, more than ever, science is part of the social world and institutionalized in nearly all countries. Some philosophers like Adorno and Feyerabend developed very critical perspectives on that topic.
    There are some associated problems: e.g. scientific superiority of nations, science as a measure of suppression or science and power, liberty and technological development, social science and social technology, medical progress and personal freedom.
    But on the other hand there is an international exchange of ideas in science that seems free and often liberal.
    What do you think about the liberating power of science? What do you think is the current state in this discussion?
  • Suraiya Ishak added an answer in Organizations:
    What are the indicators or variables (attributes) to measure organizational effectiveness?

    Organizational effectiveness is commonly referred to as the degree to which predetermined goals are achieved, whereas Organizational Efficiency refers to the economical manner in which goal oriented operations are carried out- something of an input/output ratio. What are the indicators or variables to show that the organisation effective?

    Suraiya Ishak · National University of Malaysia

    In laymen term- effectiveness is about "doing the right things", whereas efficiency is about "doing things right".  Therefore organization effectiveness can best be evaluated from its' performance in terms of fulfilling the organization's purpose/objectives - if the organization's  purpose/objective is "for-profit", financial indicators such as ROI, ROA and P/E can be use as effectiveness indicators.  The reason is because such indicators represent the ultimate output that derived from doing the right things for the organaizition.  As in the non-profit organization (NPO) the indicators would be different- such as numbers of students produced, patients treated and etc., referring back to the main objectives of the particular organization.

  • Maher Ibrahim asked a question in VB.NET:
    How we can convert .tif raster into .bgd format using Dotspatial in Vb.Net?

    I want to convert a tif file format into .bgd format to do analysis like hillshade in dotspatial with vb.net

  • Can anyone explain the jurisprudence of data protection law?
    Is jurisprudence of privacy law different from jurisprudence of data protection law?
    Siti Hajar Mohd Yasin · Universiti Teknologi MARA

    Privacy law comprises of the bodily privacy, communicational privacy and informational privacy. Data protection is only concerning the informational privacy.

  • Roshan Jahn Mohd Salim asked a question in IC50:
    IC50 determination

    Hello there,

    I would like to ask an opinion regarding the issue as described: I had a Growth Inhibition % associated with their concentration as following:

    200 ug/ml:15%, 100ug/ml:20%, 50ug/ml:22%,25ug/ml:24%, 12.5ug/ml:23%.

    How do I interpolate this result? Even though the growth inhibition is very low, I cant determine the IC50 as none of the concentration is giving 50% of inhibition. If I do increase the concentration there would be color interference. Please advice. Many thanks.

  • Tessie Mcneely added an answer in Biofilms:
    How can I stain biofilm with Congo Red?

    I need to stain bacteria growing on transwells in vitro, to make sure the bacteria are producing a polysaccharide containing biofilm.  How can I use Congo Red to stain the biofilm? Is there a better stain to use?

    Tessie Mcneely · PhotoSonix Medical Inc.

    Thank you Ammar for this reference and suggestion.  I'll give it a try.

  • Md Abdus Sabur added an answer in Adsorption:
    What is physical sorption (physisorption) and what does it "include"?

    So, are there any flaws in the text?

    Physical sorption results from the electrostatic and van der Waals interactions (forces). Sometimes only van der Waals forces are mentioned. Although motivation to do so is not clear, there could be at least two possible reasons. First of all, term “van der Waals interactions” is sometimes used loosely for the totality of nonspecific attractive or repulsive intermolecular forces. Secondly, if adsorption is caused due to the electrostatic interaction, sometimes it has been called electrostatic adsorption, e.g., there are three types of adsorption - chemisorption, electrostatic adsorption and physisorption. As terms “electrostatic forces” and “Coulombic forces” are synonyms, in some research papers the latter term is used, for example, …

    Md Abdus Sabur · University of Waterloo

    H-bonding is a class of electrostatic attraction. So, when adsorption takes place through the formation of H-bond, I would term then physisorption. 

  • Dennis Robert added an answer in Computer Vision:
    Why translation vector of an extrinsic matrix does not correspond to the camera position?

    Given an extrinsic matrix, it is granted that it transforms a point in world coordinate to a point in camera coordinate.

    Let E be the extrinsic matrix:

    R11 R12 R13 t1

    R21 R22 R23 t2

    R31 R32 R33 t3

    0       0      0    1

    Technically, extrinsic matrix gives you the orientation of world coordinate frame with respect to camera coordinate frame. It also gives you the translation of world coordinate frame with respect to camera coordinate frame. Thus, t1 should be distance from camera coordinate origin to world coordinate origin in x direction and t2 in y direction and t3 in z direction. This indirectly means that camera coordinate origin is located -t1 in x direction, -t2 in y direction and -t3 in z direction from the world coordinate origin. That is, (-t1, -t2, -t3) is the camera coordinate origin in world coordinate frame. Camera coordinate origin should correspond to camera position and thus (-t1, -t2, -t3) should correspond to camera position in world coordinate frame. However, it isn't so.

    Let Xw be the camera position in world coordinate frame and Xc be the camera position in camera coordinate frame. We need to find Xw.

    Then:

    E * Xw = Xc

    Xc is (0,0,0) and hence:

    Xw = -1 * (R)' * (t), where R (3*3) and t (3*1) are the rotation and translation components of E respectively.

    Why is Xw not equal to (-t1, -t2, -t3)?

    Yes, but the position of the origin (which is what we are concerned with), does not change by rotation in X,Y or Z axes.

  • Fiona Pixley added an answer in Macrophage:
    Why don't the M2 Marker Genes express in RAW 264.7 cells?

    Now I am trying to induce macrophage M2 phenotypes in different cell types. It works fine in BMDM from C57 mice. But when I turn to RAW264.7 cell lines, it did't work. I used the same condition (10 ng/ml IL4 for 24h) but almost all the M2 marker genes did't express. Why? Anyone know happened here? From our ChIP-seq data we think there is not so much difference between BMDM and RAW 264.7. When we knockout or knockdown our protein in both cell lines it behave the same in M1 phenotype, so we want to know whether it's the same in M2 phenotype. Now I am stopping inducing.

    Fiona Pixley · University of Western Australia

    I suspect that primary macrophages are much more plastic compared to macrophage cell lines and would suggest that you keep working with primary cells if you can. I know they're much more difficult to manipulate in terms of knock down approaches but they're a better system for examining activation phenotypes.

  • Fernando Godinez added an answer in Zinc:
    Has anyone tried to prepare zerovalent zinc nanoparticles reducing Zn2+ with sodium borohydride?

     Although literature reports this protocol I've tried but instead of getting grey particles I got white ones that I suppose to be zinc oxide...

    Fernando Godinez · Center for Research and Advanced Studies of the National Polytechnic Institute

    I have been working with Ni, Co and Cu nanoparticles, one of the biggest problems is to obtain metallic nanoparticles because they are very reactive, however using approtic solvents as THF and surfactant as tetrabutylammonium boronhydride, I could obtain good results, of course you should mantain inert atmosphere during reaction (N2 or Ar). good look!!

  • Daniel J. Tulloch added an answer in Mac:
    Stats & Graph Programme(s) for Mac

    Can anyone recommend good statistical and good graphics apps / programmes for a Mac? (It would be helpful, if you could describe your experience with them.) Thanks.

    Daniel J. Tulloch · University of Otago

    Hi Christoph,

    I use STATA as a general purpose statistical software package. STATA can be difficult to begin with as you must learn the coding syntax. In recent years, the user-interface has become more accessible. STATA is accompanied by an extensive instruction manual which I find useful and adequate enough to complete the analyses I need. The instruction manual highlights the syntax, theory, options available, and practical examples for most tests.

    There are additional learning supports available such as the STATA forum, STATA youtube page, and STATA journal (published quarterly); all are full of user-written commands for specific models. The downside, depending on which license you need, is that STATA can be expensive.

  • What is the best technique for improving wear resistance on stainless steel without compromising the corrosion performance?

    See above

    Everardo E Granda-Gutiérrez · Corporación Mexicana de Investigación en Materiales

    What technique do you suggest?

  • How do you predict raman spectra for inorganic metal complexes with amine groups?

    How do you predict raman spectra for M(L)nXn.  L= aromatic amine, X = halogens.  Is there any software to identify the spectral measurements?

    Sudarsan VenkatRamani · University of Florida

    Firstly, If the symmetry of the molecule is known then a manual normal modes of vibration analysis can be done. Identifying irreducible representations and then ruling out the one's that do not correspond could be a good starting point. If access to high performance computing facility is available, then I believe one can perform a ground-state optimisation of the structure (run a single point calculation) and then also request for the frequencies to be shown. As suggested above by Luca, comparing this data with the experimentally obtained spectrum should help resolve most of the task.

  • W N N W Marzudi asked a question in CST:
    What need to consider in designing stub of MIMO Antenna design using CST in wideband frequency?

    Add stub to improve coupling between element in MIMO antenna. Is there any specific consideration for stub design in CST. How to check the actual impedance either the stub match 50ohm

  • John Sowa added an answer in Linguistics:
    Is human thought a form of internal speech or is it independent of language?
    Can it be that, by necessity, all psychological faculties are innate and learned, biologically restricted and socially constructed at the same time? At the end, the human body is (innately) pre-structured to interact with the world external to it. Is it possible, therefore, that most discussions about Sapir-Whorf hypothesis are just a case of simple misunderstanding?
    John Sowa · VivoMind Resarch, LLC

    I agree with Bill's response to Wes.  Peirce made the point that "symbols grow" -- and that includes all combinations of symbols in language. He made the point that the listener's interpretation of what the speaker says may be more developed, less developed, or just different from what the speaker had intended.

    For example, consider a newspaper report of some scientific discovery.  The reporter, who is not likely to understand the details, will have a less developed interpretation than the scientist who made the announcement.  But another scientist who reads the newspaper version can often "read between the lines" to derive a better understanding of the original science than the reporter who wrote the article about it.

  • Hossein Mehdaoui added an answer in Protamines:
    Do you have experience with protamine bolus dose and ECMO circuit clotting?

    I recently had a pediatric patient on CPB which we transitioned to ECMO which of course continued to surgical site bleeding.  The surgeon requested 1/2 dose protamine for which I administed and approximate 5 minutes later the ECMO circuit clotted off.  Has anyone else experience this event?  Is this common practice if you were in the same situation where you work?

    Hossein Mehdaoui · Hospital Centre University of Fort de France

    I work in an adult critical care unit performing ECMO. We never used protamine in this indication.

    1- We check for surgical solutions against local bleeding (major issue) and we stop heparin infusion

    2- We try to optimize hemostasis parameters using platelet transfusions, FFP, clotagen

    3- We change the ECMO circuit

    4- We consider activated factor VII (Novoseven) after hemostasis optimization

    5- We always investigate to diagnose infectious complications

    Hope this may help.

  • Mark David Levin added an answer in Morphology:
    Why is it that in any single lead are QRS complexes not always the same height even though they are the same morphologically?

    For example: I have an ECG if front of me now.

    The QRS complexes in lead II are morphologically the same but they are not all the same height, varying from 6-10mm. This height differences is present in all 12 leads. Can anyone explain this for me and put an old man out of his misery?

    Mark David Levin · Washington University in St. Louis

    The qrs amplitude in the black and white ecg seems to vary with respiratory cycle.  Looking at the v5 lead rhythm strip, you can see that not only is the amplitude changing but the rate changes some as well.  This may suggest that the is a change in impedence ( and hence waveform amplitude) with inspiration.  It is interesting however that this is a much more subtle change in heart rate than often seen with pronounced sinus arrhythmia.  Any more details about that patient? The colored ecg has some clear abnormalities but lacks a rhythm strip

  • Carol Oliver added an answer in Education Research:
    Which are the most effective ways to do vocational guidance for students selecting science careers?
    There are decreases in the number of students who choose science careers because
    they fear not having good performance.
    Carol Oliver · University of New South Wales

    I note I mistyped the link to the Mars Lab! It is http://www.themarslab.org

  • A. K Gautam added an answer in Fabrication:
    I have to fabricate an microstrip patch antenna of dimensions ,,,, length of substrate =21mm and width =18mm . is it possible to fabricate it.

    I think its size may be a problem.

    If yes then if any one know where to fabricate ,please tell me.

    A. K Gautam · Govind Ballabh Pant Engineering College

    My number is 8979719397

  • João L Ellera Gomes added an answer in Arthroscopy:
    In patella instability with TT TG ratio 20 mm, Caton Deshamps index 1.34, trochlear dysplasia of grade 1, what should be the sequence of corrections?
    I usually perform distalization of tibial tubercle as the first procedure to correct the patella alta. If need be, I add MPFL reconstruction as the second staged procedure. I never had to add trochlear plasty.
    João L Ellera Gomes · Universidade Federal do Rio Grande do Sul

    Static image exams are always important in patella instability, but I will never decide which surgery will be more appropriated without evaluating the patella tracking during active flexo-extension. In patients with subluxation in extension, Fulkerson alone is frequently not enough. 

  • Sebastian Raschka added an answer in Python:
    SCATTER PLOT: Comparing two different datasets

    I have two different fits files with different shapes (i.e. (310, 256, 256) & (560, 4, 786432)). How do i make two scatter plots to compare them using python? That's plotting one data on the other.

    Sebastian Raschka · Michigan State University

    Or the same thing in 3D?

    from mpl_toolkits.mplot3d import Axes3D
    import numpy as np
    from matplotlib import pyplot as plt

    # Generating a Gaussion dataset:
    # creating random vectors from the multivariate normal distribution
    # given mean and covariance
    mu_vec1 = np.array([0,0,0])
    cov_mat1 = np.array([[2,0,0],[0,2,0],[0,0,2]])

    x1_samples = np.random.multivariate_normal(mu_vec1, cov_mat1, 100)
    x2_samples = np.random.multivariate_normal(mu_vec1+0.2, cov_mat1+0.4, 100)


    fig = plt.figure(figsize=(8,8))
    ax = fig.add_subplot(111, projection='3d')

    ax.scatter(x1_samples[:,0], x1_samples[:,1], x1_samples[:,2], marker='x',
    color='blue', alpha=0.7, label='data from fit 1')
    ax.scatter(x2_samples[:,0], x2_samples[:,1], x2_samples[:,2], marker='o',
    color='green', alpha=0.7, label='data from fit 2')

    ax.set_xlabel('variable X')
    ax.set_ylabel('variable Y')
    ax.set_zlabel('variable Z')

    plt.title('3D Scatter Plot')

  • Which one is a better start: cultivation-independent or cultivation-dependent approaches to microbial community assessment?
    Only a very small fraction of microbes living in soil can be cultured using classical approaches. On the other hand, the use of cultivation independent methods has greatly improved our understanding about microbial community structure and function in soil.
    Jakson Leite · Federal Rural University of Rio de Janeiro

    I agree with Lira Junior. But one advantage of cultivation-independent approaches is that it allows a preliminary analysis of the associated community and can help to draw future strategy for cultivation-independent approach. We recently used data of cultivation-independent approach to isolate Bradyrhizobium associated with roots of sugarcane (Rouws et al 2014).

  • Daniel J. Tulloch added an answer in Causality:
    Could any one help to one of my colleague- to find out how many lags to be taken for valuing the granger causality test

    She is doing research on  cross listed stocks ( ADRs , GDRs) for valuation purpose she is using granger causality test through E views software, to compare the companies local and international stock market price. For that she need suggestion, of how many lags to be taken into consideration for the above test,

    Daniel J. Tulloch · University of Otago

    Hi Nuzhath,

    I have run Johansen co-integration tests in STATA and am aware of Akaike Information Criterion (AIC) to automatically optimize for lags (this is specifically useful in panel data - accounts for heterogeneity of panels).

    It would appear that this option is available for Johansen's cointegration test using Eviews. Perhaps see if EViews provides a similar option to AIC for the Granger causality test?

    http://forums.eviews.com/viewtopic.php?f=18&t=1247

    Also, during a cursory search of academic articles related to your specific problem, I did find this well-cited paper; this may be of use to your friend:

    Lag-Length Selection and Tests of Granger Causality Between Money and Income
    Daniel L. Thornton and Dallas S. Batten
    Journal of Money, Credit and Banking
    Vol. 17, No. 2 (May, 1985) , pp. 164-178
    Published by: Ohio State University Press
    Stable URL: http://www.jstor.org/stable/1992331