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
  • Mostafa Rezaei asked a question in Graphene Oxide:
    Role of reduce graphene oxide in photocatalytic activity?

    role of reduce graphene oxide in photocatalytic activity? please help me

  • Mandy Taisto added an answer in Antibodies:
    Does anybody have experience with muscle fiber typing? Any suggestions?

    I'm trying to at max label three types of fibers/myosin isoforms with little success in gastroc and sol tissues.

    So in my KO mouse model I'm trying to assess muscle pathology according to fiber type. I've tried two different batches of antibodies for fast and slow (Lecia and Abcam), I've tried using vector's M.O.M (mouse on mouse) kit, I've tried it without, I've varied incubation times and antibody concentrations and it always looks like garbage.  Either there is little labeling or everything is labeled. 

    Frankly, I'm at a loss for words as to why I can't get decent labeling. I will post the various information/protocols that I've attempted. 

    Any suggestions are greatly appreciated.   

    Mandy Taisto · Northern Michigan University

    Thank you all for your suggestions and papers! Ornella, would you mind sending your protocol? My email is ataisto@nmu.edu.   Thanks again folks. Hopefully I can post a successful progress report! 

  • Jaafar Mohammed added an answer in Seismics:
    What is the behavior of fiber in underground structure under seismic impact?

    The behavior of fiber for tunnel under seismic impact.

    Jaafar Mohammed · VŠB-Technical University of Ostrava

    Mr.Jianhua Liu, Yes ,you're right about that , but I need it under seismic load

  • Huasen Wu added an answer in Smartphone:
    What are some measures for daily smartphone use?

    Dear fellows, 

    I would like to open a threat that summarizes papers using measures for daily smartphone use, considering use as a "trait" (daily) rather than a "state"(mood, etc.) 

    Items should be like "On a regular day, how often do you check your phone" or "What app do you use most often on a daily basis"....

    As this is a topic of increased importance, I thank everyone for contributing and hope we can help each other out by summarizing findings. 
    Cheers, 
    Frederic H. 

    Huasen Wu · University of California, Davis

    Some recent work that may be related:

    Lee, Yu-Kang, et al. "The dark side of smartphone usage: Psychological traits, compulsive behavior and technostress." Computers in Human Behavior 31 (2014): 373-383.

    Bolle, C. L. "Who is a smartphone addict? The impact of personal factors and type of usage on smartphone addiction in a Dutch population." (2014).

    Chui, Raymond Chi Fai. "Smartphone Usage, Social Relations and Life Satisfaction of Hong Kong College Students." New Media, Knowledge Practices and Multiliteracies. Springer Singapore, 2015. 171-178.

  • Annick Daneels added an answer in Mesoamerica:
    Has anyone found any effigy mounds in Mesoamerica?

    I currently know of two - one (a snake) at Casas Grandes (Paquime) in Chichihuah and the other in the Municipio de Tacuichamona, in Sinaloa, (Weigand, personal communication 2010).  However, I am hereby canvassing the archaeological community to learn of any others.  Any and all information will be duly acknowledged in publication.  Many thanks!!

    Annick Daneels · Universidad Nacional Autónoma de México

    Will do!

  • Eirini Gkougkoulia asked a question in Ethanol:
    What is the best way to extract proteins from fluke tissues stored in ethanol?

    Any suggestion is wellcome since i dont have experience with tissues stored in ethanol.

  • Matthias Haucke asked a question in Multi-Level Model:
    When doing multi-level modelling in SPSS: "This co-variance parameter is redundant, cannot compute test statistics " What can I do?

    When I do multi-level modeling via the mixed models option in SPSS the intercept can be calculated as an random effect. However, the problem occurs when I want to add random slopes. When I add covariates as random effect SPSS gives following output for "This co-variance parameter is redundant, cannot compute test statistics and confidence interval " What can I do?

  • Howard King added an answer in Medicine:
    Medical Student Networking
    Hi there, I just wanted to let you know of a site I have set up called Memorable Medicine. It's a free revision and social networking site for medical students and junior doctors. Here's a link to the internal medicine section: http://www.memorablemedicine.com/course/view.php?id=7

    Please get in touch if you would like to be more involved in its evolution!

    Regards,
    Nick
    Howard King · Town Hill Hospital, Pietermaritzburg, South Africa

    Nick

    It is extremely difficult to gain access to your website - end up with Japanese writing, but despite translating it does not appear to give access to your website.

    Howard.

  • Hello, Having the scatter search algorithm and the genetic algorithm. Which one is simpler (algorithmic complexity, sophistication of operators,..)?

    Based on many criteria such as : algorithmic complexity, sophistication of the operators, ..... and many others. Which one of the Scatter Search and the Genetic Algorithm is simpler ?. Any references are welcome. Thanks in advance.

    Fanrong Xie · Nanchang University

    I also agree with Antonio. I would like to  choose GA, too.

  • Ali Chaibakhsh added an answer in ANFIS:
    Warning: Some input values are outside of the specified input range?

    Hello every body, I am working on ANFIS system. When I want to evaluate the ANFIS i got this error Warning: Some input values are outside of the specified input range. In evalfis at 75.

    how to rectify this. I am new for ANFIS?

    Ali Chaibakhsh · University of Guilan

    Hi, you could perform the following tasks to deal with this problem:

    1- normalize dataset by dividing on the maximum value of each input.

    2- on fuzzy GUI, choose the smallest and largest membership functions as "Z" and "S", respectively, instead of for example Gaussian mfs.

    3- you could also completely ignore this error, especially in the cases that you try to optimize the parameters of membership function. you could do this by writing "warning off" on command window.

    4- export the FIS file to drive, and try to open edit by Matlab editor, for example

    open myfile.fis

    and manually change the upper and lower bounds for input and output membership functions.

  • Is gender a natural inhibiting parameter in learning and doing mathematics and mathematical thinking?
    In most traditional societies there are some differentiating parameters whose origins have social and cultural basis. Contemporary societies refute that not because of simply liking the idea of being equal but because it has no scientific merit and empirically and scientifically false. In my classes for instance there are good female students with a higher score than some boy students and also some boy students with higher score than some girl students. That simply proves their performances do not at all depend on their gender.

    But this idea still lingers even in some prestigious schools like Harvard University, in which Larry Summers, a onetime president of the university said “women have some natural limitations in learning and doing abstraction, mathematics and in general things that are mathematical”, which I found it shocking but at the same time false. Again, the dean of business school of the same university apologized for treating female business students and faculty members with contempt and substandard membership. That means the university has a systemic problem in its foundations regarding women and what they are capable off naturally as men in all aspects of human endeavors to perform and achieve equally with high standards as men.

    For instance here in Research Gate, I have followers and who I follow, that are women and mathematicians, physicists, engineers, chemists, business women, philosophers, economists, artists, etc, practically in all aspects of science and the arts that mathematics is used. There are also women of global stature that perform and achieve well in science and mathematics.

    What do you think?
    Dejenie A. Lakew · John Tyler Community College

    Dear saeed,

    If you need to support an idea of someone you can vote for it, but still I have difficulty understanding your points as you paraphrasing an earlier comment made. 

  • Diego Valencia asked a question in Turbidity:
    I tested a blend based on PAC and a cationic floculant for a low alkalinity water. In jar test went well but not in plant. What other blend can I try?

    pH: 7.0 - 7.3

    Turbidity: 6.0 - 12.0 NTU

    Alkalinity: 30 mg/l CaCO3

  • Remi Cornwall added an answer in Causality:
    Is a concept of causality required in science?

    John D. Norton characterized "Causation as Folk Science",

    (see http://quod.lib.umich.edu/p/phimp/3521354.0003.004/1).

    Would you say that causality is a well-defined concept that is

    essentially required in science?

  • George Stoica added an answer in Personality:
    What is the most difficult challenge for a human?

    Personal question.

    George Stoica · Mathematics and Statistics

    To be clever.

  • Luisiana Cundin added an answer in Climate Science:
    Do you think there is any substantial and meaningful difference between stationary stochastic processes and chaotic systems?

    It seems in the history of climate science that most scientist spoke of the climate as being stochastic, until about the mid 1980s, where a shift occurred and the climate was more described as being chaotic. Obviously, the shift reflects the wishes of climate scientist to enable prediction and mathematical capture, but it appears only wishful thinking, at best. So, as a survey, what does the RG community think about this fundamental conundrum in the Sciences?

    Luisiana Cundin · Die Wand : leben heißt kampf

    I present the following hypothesis for "From whence does order come?" 

    "By virtue of system constraints, does order arise and is nothing more."

  • Is chaos an utterly orderless system, or a system with a highly complex order ?
    All systems at macro level that are observed to have orders are chaotic at quantum levels.
    Dejenie A. Lakew · John Tyler Community College

    Dear Saeed,

    I am not sure what your point here is. Are you supporting what Stefan has said? 

  • What role does the electromagnetic spectrum play in remote sensing?

    Different roles of electromagnetic spectrum and also how the value of satellite imagery is lost when they are printe.

    Jennifer Phillips · University of Colorado Colorado Springs

    Do you need band information or are you asking for specific wavelength information (i.e.: infrared as an indicator for photosynthesis)?

  • Oscar Otero added an answer in Rabbit:
    What is the best procedure to purify Ab from rabbit test bleed ?

    I have test bleed from immunized rabbits and would like to purify my Antibody of interest from it. I was thinking of the following steps based on literature analysis :

    1. Ammonium sulphate precipitation.

    2. Protein A column

    3. Ag-conjugated column.

    What would you suggest ? This is my first time purifying Ab from crude. 

    Oscar Otero · Finlay Instituto

    Dear Sivasankari , in agreement with above answer, I will choose Protein A/G affinity chromatography to purify IgG from rabbit serum in this scale. Purification protocols based on differential of solubility (e.i salting out with ammonium sulphate) are more adequate for large volumes of serum. Bioaffinity chromatography is an excellent option but you must have enough antigen to coupling to a matrix (mgs). On the other hand, it could be "the tale of the egg and the hen". If you dont have pure antigen all antibodies that you obtain will be against all proteins  immobilized onto  the matrix.

    I understood that you want to use these polyclonal rabbit antibodies in a WB and in accordance with Natalie´s suggestion, you assayed complete serum in WB. Many bands were observed in this assay in both immunized and non immunized rabbit sera including the protein band of interest. Am I right? If yes, I question you, why non immunized animals have antibodies titer vs your Ag? What is the serum dilution that you are using? What  kind of antigen are you using?

  • How do I use principal component analysis (PCA) for mixed data?

    I have a data-set about cities features like population, poverty, economic position, income etc. population, poverty and economic position are continues but poverty is based on a scoring. We have 100,70,50 and 30 scores for cities (only these values). cities with 100 score has highest poverty and cities with 30 score has lowest poverty. Now i want use PCA for this data-set.

    * Is PCA suitable for this mixed data because one of the assumptions of PCA is continues inputs. If not, what are suitable techniques to do that? Finally i need rotated component matrix based on varimax rotation and need a software or package to do the rotation on loadings for me.

    * Should i standardize data when using correlation matrix (not covariance) in PCA? (currently because of some theoretical aspects i select a city as base city and it's feature values as denominator of other cities values + removing outliers using x-mean(x)>=2S.D rule)

    * Should i use correlation matrix here? we use it when we have different scales for features but here my data is scaleless.

    * Normal distribution of inputs is an assumption of PCA? because my inputs don't show normal distribution, should i transform data using log()?

    Julia B. Smith · Oakland University

    Not if you are putting the measure into a scale with other items, as a means of data reduction.  If you are testing psychometrics on your scale, I would try it a couple different ways to see which do and do not make a difference.

  • Anver va added an answer in Comsol Multiphysics:
    Is there anyone who can help me converge this highly deforming model in Comsol Multiphysics 5?

    My purpose is to model a two dimensional living cell assuming it as a hyper-viscoelastic material. In this model the cell boundary undergoes a prescribed deformation as a function of time and the radius increases from 12.6 micrometer to 30.9 micrometer. I faced various kind of errors. Also I tried adaptive mesh refinement but there are variety of other errors. Every solution will be appreciated.

    Anver va · University of Kerala

    Try moving mesh conditions,
    If you have a Geometric Non-linearity option enable it, if not you have to add moving mesh separately.

    I am not sure if this works. But worth a try..., 

  • What is 4T1–6A1 transition?

    . For octahedral Mn+2 emission peak is red orange due to 4T18-6T18 transition and for tetrahedral it is 4T1-6A1 transition. 

    Brian M Walsh · NASA

    The subscript g is always added to irreducible representations of the Oh group. So, in octahedral you write 4T1g-6A1g, while in tetrahedral you write 4T1-6A1

  • Can you suggest articles about FL lesson planning paradox?

    I HAVE BEEN LOOKING FOR RESEARCH ON LESSON PLANNING PARADOX AND THE WAYS OF DEALING WITH IT DURING FL PRACTICUM. Thank you for your help in advance.

    Overcoming the "language gap" is not just a matter of sectoral policy and budgeting. The challenges of learning a language are fundamental: even before the process starts, a learner's own cultural background and personality help determine performance in the new language.

  • Please, does any one have a suggestion concerning morphological techniques in digital image processing?

    CAMERA IMAGE PROCESSING

    Nasim Nematzadeh · Flinders University

    MultiScale DoG filtering. There might be a need for elongated version of DoG, when the morphological demands need considering the directionality information as well. This filtering is similar to Gabor wavelet, with weigh long history before wavelets in the CV but a more bio plausible technique...based on recent biological findings.

  • Ivan Krejci added an answer in Data Acquisition:
    Can anyone suggest a data acquisition tool for PC?

    I would like to take out some data from the micro-controller like ADC value, sensor values on PC so guide for data acquisition.

    Ivan Krejci · 1. HAAL Elektro, Ltd. 2. College of Polytechnics Jihlava

    If you are looking for a data aquisition system, you should have to determine the system parameters you need, e.g. number of channels (number of independent or synchronized channels), measured signal frequency spectrum and its dynamics (these parameters determine the ADC sample rate and its resolution - number of bits). Of course the universal solution is any NI system because they offer hw and sw products. But if you need anything smaller and cheeper I can recommend you any kit containing the powerfull ARM microcontroller, for example TI Tiva or Stellaris LauchPad, or something like it. These kits are equipped with complete debugging needs and their ROMS contain usefull sw libraries, and the processors support floating point operation, especially fot the DSP. The microcontroller itself contains two independent ADCs with the sample rate up to 1 MSPS and 12 bit resolution. You can use the USB channel (UART1) for the communication with a host PC. I have good experince with them.

  • Kristian Svendsen added an answer in FDA:
    Could anybody help me with the guidelines or recommendations of FDA/EMA for the administration of ODT in bioequivalence & bioavailability studies?

    Could anybody help me with the guidances or recommendations of FDA/EMA for the administration of ODT in bioequivalence & bioavailability studies? Thanks in advance

    Kristian Svendsen · Universitetet i Tromsø

    It would seem this guidance does cover at least some of the issues related to orally disintegrating tablets (se chapter 5.1.1 for instance) but it is not mentioned explicitely as far as I could see in the guidance. http://www.ema.europa.eu/docs/en_GB/document_library/Scientific_guideline/2009/09/WC500003008.pdf

  • Salah Alsamarraaee asked a question in Gears:
    How is the distribution of car engine capacity of different proportions on the front and rear axis?

    linking of gears by the laws should be changed rotational speed between the front and rear axle and this is not possible

  • Massey Mizuno added an answer in LC-MS/MS:
    How can I solve my carry over issue in LC-MS/MS?

    Hello! I am having a carry over problem in Tulathromycin by ESI-LC-MS/MS. The C18 columns used are Kinetex and Eclipse.  The mobile phase is 0.1 % formic acid in both water and acetonitrile. The carry over issue existing in different columns as well. Could you please share your suggestions to solve this problem. We are using a needle washing solvent as (1:1:1 of IPA/Methanol/Acetone and 1:1 water/methanol). Thank you, Seeni

    Massey Mizuno · Canadian Food Inspection Agency

    What is the LC manufacturer's carry over specification?  You may be fighting against something that you cannot fix.  You can increase needle wash volume.  You can increase a column equilibration time (a good measure is that if it takes 5 min for analytes to elute from column, then it will take the same or longer time to wash out the column and equilibrate.  Another thing that you can do is to arrange a sequence of running samples.  Start with ascending order in concentration, and then descending order.  Run a blank-blank (just eluting solution mix) after the last descending sample to show that there is a minimum carry over, etc.

  • Aline Collin added an answer in 3T3-L1 Cells:
    I am having a problem keeping 3T3-L1 cells alive when differentiating them with troglitazone. Has anyone encountered this?

    I grow 3T3-L1 cells for my research. In the differentiation process, I use a medium that contains troglitazone for 2 days. This has worked very well for about 1year, but the past couple of time, the cells started dying shortly after the differentiation starts. I am not positive it's from the troglitazone medium, but that's really the one big difference. Before I used IBMX.

    Aline Collin · University of Alaska System

    Hello Alexander,

    I'm actually trying this right now, I should know over the weekend. 

    This is happening on a brand new set of cells.

  • Anver va added an answer in Comsol:
    Heat Transfer in COMSOL ( for designed microstructured fiber ) ?

    Hi , 

    I have modeled a fiber structure ( microstructured one ) in COMSOL 3.5A using FR module. I need to study how the mode profile is changing with temperature (30-60 degree ) in steps of 10 degree . Can anyone let me know how to use heat transfer in COMSOL for my modeled structure?

    I appreciate your help 



    Anver va · University of Kerala

    you can use Thermal expansion in solid mechanics. you can find this physics under structural mechanics module.

    1. Set Tref as 30[degC] and T as 60[degC].

    2. Use Auxiliary parametric sweep under study extensions put "range(30,10,60) 


    Also you can try "Thermal expansion" that has "Heat transfer" and "structural mechanics" modules linked together.

    Have fun Comsoling.!!