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.

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  • Kasturi Dasgupta added an answer in Plant Tissue Culture Techniques:
    Does anyone have a good DNA extraction protocol from plant leaves without using liquid nitrogen?

    I have used to to three protocols but very minute quantity with high impurity DNA extracted, so i need little more good protocol.

    Kasturi Dasgupta · USDA-ARS / University of California, Davis

    Simply use fresh biological material for DNA extraction. Use grinder to crush your leaves and then use CTAB extraction protocol. I use it for most of my DNA extraction from various plant species. Its usually very clean.

  • Robert Gieseler added an answer in Dendritic Cells:
    How can I improve the purity or positive rate of dendritic cells?

    When we isolate the dendritic cells from mouse bone marrow, how to improve the purity or positive rate of dendritic cells?

    Robert Gieseler · Rodos BioTarget GmbH

    Dear Enping,

    Apologies for misspelling your first name...

    Robert

  • Jackson Achankunju added an answer in Plant Growth Regulators:
    Are various effects of LED lighting on algae explored?

    Apart from high luminous efficiency, less power consumption and longer service life, light emitting diode (LED) systems are consider to have several physiological effects including plant growth regulator etc in higher plants. I was wondering if similar studies are available in algal systems. Any feedback is most welcome.  

    Jackson Achankunju · A'Sharqiyah University

    Dear Vaibhav,

    Please have a look at the following paper.

    High-Density Algal Photobioreactors Using Light-Emitting Diodes 

    Choul-Gyun Lee and Bernhard 

    http://deepblue.lib.umich.edu/bitstream/handle/2027.42/37932/260441002_ftp.pdf

    Good luck!!

  • Muhammad Yasin added an answer in Electron Transport:
    Is it possible for a Fe-S protein to have its sulfur (S) substituted by selenium (Se)?

    Considering that organic selenium (as seleno-methionine) is not metabolically differentiated from sulfur-methionine, is it possible that this substitution occurs also on Fe-S proteins at the Complex I and II of of mitochondrial electron transport?

    Muhammad Yasin · Previous: Colorado State University, USA

    Hi, 

    I think so. I have been working with plant treated with Se. and what I found when certain plant species are treated with high concentration of Se the total concentration of S (in acid digested samples) is affected negatively in above ground plant parts and plants protein contents are also affected by supplementation with high Se content in soil. 

  • Valentine Azom added an answer in Biometric Identification:
    Where can I find a standard fingerprint database?

    Where can I find a standard fingerprint database?hello every one, as i have started my research on bio-metrics, and i am focusing on fingerprints, i need standard database for my experiments. i need the FVC 2000 or 2002 or 2004 entire database. IF any one has it please do share it.

    Valentine Azom · University of KwaZulu-Natal

    http://biometrics.idealtest.org

  • Dee Donald asked a question in Purchasing:
    What is your opinion of public health 101 healthy people healthy populations? Is it a good text to use???

    I'm looking into purchasing and wanted more opinions on it.

  • Rane L. Curl added an answer in Plagiarism:
    What percentage (maximum) of plagiarism is generally allowed in a review paper?

    I want know about what percentage of plagiarism is allowed to make a review paper acceptable in journals.

    Rane L. Curl · University of Michigan

    Yes the original question was about Review articles. Since a Review article is describing the work of others,  it is inevitable that much of the same vocabulary and phrases from other work will be used. The result would be that a plagiarism detection program would find much overlap - even though there is zero plagiarism, which is claiming the work of others is yours.  I agree that software cannot make that distinction.

  • Amit Nahor added an answer in Band Gap:
    How to find the Band gap energy of an Oxide Semiconductor from Photoluminescence spectra?

    1.    Is it possible to find that whether the material is Direct or Indirect bandgap semiconductor from PL spectra?

    2.   What other information, we can get from PL spectra?

    THANKS

    Amit Nahor · Hebrew University of Jerusalem

    I will need to see the spectra in order to help some more. 
    As Arindam Mallick suggested using the Tauc plot is a more accurate way. 
    In short, in both plots (Tauc or PL) if you extrapolate the linear regime of the plot to the energy axis, the point of intersect with the axis gives the band gap energy. 

  • Y. D. asked a question in Cell Culture:
    How to test toxicity in a cell culture experiment?

    What is the protocol for adding a mixture to a cell culture to test for cellular toxicity, proliferation, etc?

  • Craig Charles Platt asked a question in Lymphocytes:
    Anybody researching Large Granular Lymphocytic Leukaemias ?

    Is anybody researching LGL Leukaemias

  • Hessam Aref added an answer in Transport Engineering:
    What are the main factors for installing traffic lights at intersections and how they obtained?

    Hi there;

    i want to know if there are any obvious factors, except those in MUTCD,for deciding whether or not to install a traffic signal at intersections.

    or specially, where and how did the numbers and tables in MUTCD, in it's 8 warrants, come from?

    thanks everybody

    Hessam Aref · Iran University of Science and Technology

    thanks Gerald, Perfect!

    I really thank you Kamarudin.

  • Andrew W Phillips added an answer in Online Research:
    Do you have any suggestions on articles or books that contain evidence-based best practices for online surveys?

    Hi there,

    I am conducting a project where I hope to send research participants consent and a survey over the internet. I have seen survey monkey used a lot but would like to use a reliable and valid tool, if possible. I am looking for articles or books on best practices for conducting survey based online research.  Any help would be greatly appreciated.

    Best regards,

    Kayla 

    Andrew W Phillips · Stanford University

    Agree about the Dillman book. I just wrote a review paper on the topic (still in press or I would share it with you)and his book was a major reference for the online specifics.

    As for service to use, a lot of institutions purchase Qualtrics and give free access to institution members. I'd highly recommend it if you get it for free. It even automatically saves the answers with variable descriptors for SPSS analysis.

  • Denise Goins added an answer in Collective Intelligence:
    Does Collective Intelligence Exist?

    Simply put: I'm interested in how groups 'think,' 'learn,' 'perform,' and in turn; how this relates back to the individual.

    In particular, I am currently undertaking a Ph.D. on the topic of 'Collective Intelligence' under the supervision of Prof. John Hattie

    I am fascinated by the idea of expanding the typically individualistic notion of 'Intelligence' and 'Intelligence Testing' and applying these psychological subdisciplines to 'groups' of two or more people.

    For example, is there such as thing as a 'Collective Intelligence Factor' that distinctively represents the intelligence of groups (e.g. two or more people) and if so does this 'c-Factor' set the group apart from the intelligence of its individual members?

    In other words: is the Collective Intelligence of groups greater than the sum intelligence of its individual members?

    How can this collective intelligence be measured?

    Does 'group learning' translate to 'group intelligence'?

    Can we use existing psychometric tests (e.g. IQ tests) to measure and predict cognitive differences in groups?

    What makes one group more intelligent than another?

    Do groups made up of highly intelligent members demonstrate higher 'collective intelligence' and outperform groups made up of low or moderate intelligence members?

    If you have any links, papers, conferences, or general thoughts that would help me explore these ideas; i'd love to hear from you.

    Denise Goins · Northcentral University

    Thanks, Luke, for your answer.  There is a lot there that I have considered--probably because my mother was a teacher--but hadn't really thought through.

    I also read through Mr. Locke's response to your answer.  While group dynamics are well known on some levels, there are deeper,  more complex levels that haven't been explored such as how combining intelligence of individuals equals more than the sum parts of the group.  (Note:  the idea that a marriage is greater than the sum parts of its contents).

    There is the spiritual aspect of individuals that is largely unknown but that is where I believe that greater-than-the-sum-of-its-parts comes from.  It is mystical?  Yeah, in that we know very little about our spiritual selves from a scientific stand point.  Is this lack of knowledge something that can be studied and increase the knowledge base?  I don't know.  I haven't thought it through that far.  Thus far, our knowledge about the spiritual aspect of us comes from our religion or lack thereof.  That doesn't discount it.  Not at all, in fact.

    But if I am right & that is where the greater-than-the-sum-of-its-parts comes from, could that also be where collective intelligence is best understood?

  • Allan A Jon added an answer in Folklore:
    Is anyone aware of recent research into the way that 'heritage' and 'identity' interact as constructed social processes?

    The primary fields of thought that I am interested in for this are: Heritage Studies, Folklore and Anthropology, but research into this process from any discipline could help.

    Allan A Jon · University of Canterbury

    @Steve Quinn Thank you that looks really interesting!

  • Gwen Moody added an answer in Nurse Practitioners:
    Does anyone know of any learning modules for Nurse Practitioners regarding Hepatitis C?

    Looking for a learning module that gives background information regarding the virus and the role NPs have in identifying and treating HCV

    Gwen Moody · Westmead Hospital

    I would suggest you liaise with Karleen Gribble. She has published on this.

    Gwen

  • Manidipto Mukherjee added an answer in Residual Stress:
    Modelling of Residual stress in case of arc welding in APDL?

    I am modelling residual stress in case of arc welding. I am not getting proper temperature profile. The main doubt I have is whether center of heat source should be on surface of base plate or on top of weld bead?

    I am using Element Birth - Death technique to model it.

    Manidipto Mukherjee · Jadavpur University

    I will suggest to use conduction heat transfer in transverse direction of the heat source instead of convection on top surface of the plate domain. You can use convection and radiation in bead domain. However, using convection is crucial in terms of true atmospheric condition. 

  • Frank Berninger added an answer in Climatology:
    Which GCM result is best for wind resources downscaling in complex rerrain like Nepal?

    I am currently doing thesis on "Impact of Climate Change on energy Generation from Wind Resources". 

    Frank Berninger · University of Helsinki

    With a regional climate model you are usually fixed to one GCM o it will not possible to estimate the difference of GCM:s for the simulation. The grid size of a RCM is usuall about 40 km x 40 km so it might be to small to capture the fine variation in terrain in Nepal. 

  • John A. Scales added an answer in Ultrasonics:
    Does anybody know a software capable of calculating resonance frequencies of solid parts?

    I am searching for a software used for example for design of ultrasonic tools. I need to be able to define my own model, own input material properties and be able to obtain results about resonance frequencies in the longitudinal tension - compression mode.

    John A. Scales · Colorado School of Mines

    In addition to the free C++ code on my site, you can get fortran from Al Migliori.  Unless you have a really odd shape that you must use or must go to very high eigenvalues, I would avoid finite difference or finite element.  Rayleigh-Ritz with polynomials is incredibly efficient for the geometries I mentioned.  It's all linear algebra and you can very easily exploit the elastic symmetries via matrix symmetries (at least up to orthorhombic).

  • Jackson Achankunju added an answer in Software:
    Can anyone suggest me the various soft wares by which we can study evolution of plant viruses?

    software names especially for geminivirus evolution

    Jackson Achankunju · A'Sharqiyah University

    Dear Sajad,

    Sequence analysis of the nucleic acid using the softwares available on  National Centre for Biotechnology Information (NCBI) database.The genetic distance in nucleotide  substitutions can be calculated using MEGA 4.0 and then plot against time [Ferguson et al., 2003].Hope the attached paper will be helpful.

    Good luck!!

  • Sudharsan Pandiyan asked a question in Inversion:
    How to calculate the radial distribution function of a heterogeneous system?

    I want to calculate the g(r) of two liquids that are not miscible. I want the effective potential between the molecules in two liquids. I need the g(r) for using iterative Boltzmann inversion to get the potential. So what is the effective way to calculate the radial distribution?

  • Halldis Ringvold added an answer in Echinodermata:
    Which key is best to identify sea stars?

    And if the samples are froze under -80c and will the thawing process degrades the DNA? I have about 30 samples of sea star and my study is to examine species diversity of asteroid using morphological and molecular data. This is my final year project. So, i would like to hear more from you. Thank you. 

    Thank you.

    Halldis Ringvold

    Hi

    For Molecular analysis it is best to either conserve animals in pure ethanol or freeze them. If starting to degrade I would either put them in pure ethanol or use them at once.

    The best book regarding id of Asteroidea in the Atlantic Ocean is "Starfish of the Atlantic" by Clark & Downey, 1992. Also e.g. Mortensen 1927.

    As for the Asian area I know of e.g.:

    "Echinoderms of the Asia/Indo-Pacific, Identification, Biodiversity, Zoology" by Coleman 2007.

    "Coral Reef Animals of the Indo-Pacific" by Gosliner et al. 199

    "A Guide to Sea Stars and Other Echinderms of Singapore" by Lane et al. 2003                              

    It is also Worth knowing about "The World Asteroidea Database":

    http://www.marinespecies.org/asteroidea/

    and the Attached overview article "The Echinoderm fauna of the South-China Sea" by Lane et al. 2000. 

    Kind regards,

    Halldis Ringvold

  • Christopher Wilson added an answer in Phosphoflow:
    Could anyone provide a reference for a paper/protocol that shows robust AKT signaling via phosphoflow in T cells using anti-CD3/28?

    I am using primary mouse splenocytes.

    I have used plate bound, dynabead bound and soluble anti-CD3/28.

    I am mostly looking to understand the optimal fix/perm conditions and if nutrient deprivation is necessary before stimulation.

    Christopher Wilson · Vanderbilt University

    I've really scoured the literature for timepoints that others have used for AKT signaling in T cells via TCR stim. The published literature seems to say 5-10 mins is the best time point to assess this signaling. I was hoping to utilize phosphoflow for T-reg, Memory cell, etc discrimination. I may just move to Western blot though because I have had no success with AKT via phosphoflow.

  • Philip M. Perrin added an answer in Atlas.ti:
    What qualitative analysis software should I use for process/sequential modeling?

    I am currently using Atlas.ti for analyzing transcribed conversations from which I would like to extract a process or a sequence of events. However, Atlas.ti is more content-oriented and is not really adequate to sequential analyses. Does anyone have any suggestions?

    Thanks in advance!

    Philip M. Perrin · Botanical, Environmental and Conservation Consultants

    If Sequence Viewer is what you really need and you have a PC, I guess you could try installing OS X as virtual machine? That said I would be very careful as I had to reinstall Windows once after playing around with VirtualBox.

  • Abhinay Ramaprasad added an answer in RNA-Seq:
    Has anybody tried TrueSeq stranded total RNA seq?

    Anybody tried true seq stranded total RNA seq (Illumina) for lncRNA identification and gene expression analysis after their depletion?  thanks!

    Abhinay Ramaprasad · King Abdullah University of Science and Technology

    Yes, we use TruSeq stranded total RNAseq kit routinely in our lab for gene expression analysis. No problems whatsoever. It is also possible to identify lncRNA using the kit if you couple it with riboMinus kit for rRNA depletion. 

  • Anatolij K. Prykarpatski added an answer in Differential Equations:
    What differential equation has a solution of the form F(x)=(1+1/Kx)^-2?

    I'm aware that the solution to xd/dxF(x)=F(x)(1-F(x)) is (1+1/Kx)-1, where K is an arbitrary constant.  I'm looking for a similar equation with solution (1+1/Kx)-2.  It's been a long time and I'm a bit rusty with substitutions and so forth, and I thought some mathematician on RG might have the answer off the top of his or her head.  Thanks in advance for the help.

    Anatolij K. Prykarpatski · AGH University of Science and Technology in Kraków

    The problem should be specified, namely  a sense of the  constant k ought to be explaine - if it is a free parameter appering owing to the Cauchy initial data, and there are  no other cosntants, this means that equation under question should be of thefirst order. If so, it can be found a very simople way - it is enough to finf this constant k from the solution presented above and differentiate it with respect to the independent variable x:

    one obtains easily that 

    k=(((F(x)^{-1/2}-1)⁻¹)/x),

    whence we get finally that the diffrenetial equation under search looks as

    ((dx)/(dx))[(((F(x)^{-1/2}-1)⁻¹)/x)]=0.

    What is interesting, this equation is a uniqely possible whish possesses the solution F(x) =(1+1/Kx)-2!

    Regards!

  • Phil Barbonis added an answer in Business Model Innovation:
    Is there a problem with not having a specific process for business model innovation?

    In my research I am attempting to determine if this is a problem worth futher research and will my likely outcome be another model or framework.  Is there a need to have a specific process for business model innovation that can be replicated?

    Phil Barbonis ·

    I tend to agree with M Eppler.

    At the outset, I have to say that my response may not  resonate with some of the other responses... but I tend to be "disruptive", if readers will forgive the expression.

    By their very nature, however innovative a business model is, it  may constrain creativity or out-of-the box thinking, to use an over-worked metaphor. Disruptive innovations require unusual, unexpected, imaginative and may be fantasie-land thinking. Whilst working for a Dutch MNC, some 20 years ago,  I called for and proposed the development of robotic vacuum cleaners incorporating sensors which would first go about "mapping" a room and remembering where objects like furniture were placed. When deployed, it would vacuum-clean the whole room with its dust-detecting sensors making decisions and pointing to what needs to be done. The Director of Engineering of the company laughed and said I was  letting my fantasy go wild. Today these vacuum-cleaners are availble here in Europe for less than Euro200.  I  also proposed  developing robotic chefs (i.e. robotic arms) which could turn out a meal.... my ideas came to nought at that  MNC. Had that MNC paid attention, they would have been possibly the first company to produce and market robotic vacuum cleaners. That said, it is possible a new business model might  have been necessary, and that would not be too difficult; the more difficult part  is the disruptive innovation, its conception, realization and the production in Industrial quantities that would bring in revenues.

    My advice is: look at different models and go out, gaze at the stars, walk in wooded or  beautiful landscapes and imagine how the world might be if  X or Y could be done. Then, find champion(s) who will back you up and take you to places you  never imagined....

  • Paul Chaney added an answer in Narrative Inquiry:
    Suggestions for references on using narrative analysis or narrative inquiry in grounded theory research?

    I am looking for references that discuss the use of narrative analysis in grounded theory research using case study design. References on narrative analysis alone might be also good. 

    Paul Chaney · Cardiff University

    Dear Osama Mansour,

    I hope the following references/ links and attachments may be of some help.

    Kind regards,

    Paul Chaney

    Gola, G. (2009) Informal learning of social workers: a method of narrative inquiry Source: The Journal of Workplace Learning, Volume 21, Number 4, 2009, pp. 334-346. http://dx.doi.org/10.1108/13665620910954229

    Burck, C. (2005) Comparing qualitative research methodologies for systemic research: the use of grounded theory, discourse analysis and narrative analysis, Journal of Family Therapy, Volume 27, Number 3, August 2005, pp. 237-262. http://dx.doi.org/10.1111/j.1467-6427.2005.00314.x [attached]

    Seban, D. (2009) Researching reflective field practices of elementary pre-service teachers: two-dimensional analysis of teacher narratives, Reflective Practice, Volume 10, Number 5, November 2009, pp. 669-681. http://dx.doi.org/10.1080/14623940903290745

    Reissner, Stefanie C. (2005) Learning and innovation: a narrative analysis, Journal of Organizational Change Management, Volume 18, Number 5, 2005, pp. 482-494. http://dx.doi.org/10.1108/09534810510614968

    Liebenberg, Linda; Didkowsky, Nora; Ungar, Michael (2012) Analysing image-based data using grounded theory: the Negotiating Resilience Project, Visual Studies, Volume 27, Number 1, 1 March 2012, pp. 59-74. http://dx.doi.org/10.1080/1472586X.2012.642958

    van der Vyver, Abraham Gert; Marais, Mario (2015) Evaluating Users’ Perceptions of the Digital Doorway: A Narrative Analysis, Information Technology for Development, Volume 21, Number 1, 2 January 2015, pp. 99-112. http://dx.doi.org/10.1080/02681102.2013.841629

    Maura, Striano (2012) Reconstructing narrative: A new paradigm for narrative research and practice, Narrative Inquiry, Volume 22, Number 1, 2012, pp. 147-154. http://dx.doi.org/10.1075/ni.22.1.09str

    Souto-Manning, Mariana (2014) Critical narrative analysis: the interplay of critical discourse and narrative analyses, International Journal of Qualitative Studies in Education, Volume 27, Number 2, 7 February 2014, pp. 159-180. http://dx.doi.org/10.1080/09518398.2012.737046

    Michael, Bamberg (2012) Why narrative? Narrative Inquiry, Volume 22, Number 1, 2012, pp. 202-210. http://dx.doi.org/10.1075/ni.22.1.16bam

    Sandelowski, M. (2000) Focus on Research Methods - Whatever Happened to Qualitative Description? Research in Nursing & Health, 2000, 23, 334-340 [attached]

  • Fernando Lobo Pimentel added an answer in Ranking:
    For a given node i there are k ranked lists of its neighbors. Any suggestions to compute relative importance for each ranking list in s big graph?

    graph signature

    Fernando Lobo Pimentel · Bank of Portugal

    I like Fabrice idea of the sum of the absolute value of the rank differences.

    However, if the ranks have very different relative importances, you can try to use techniques from Multiple Criteria Decision Making. Maybe you could normalize all your rank orders to a 0...100 interval and assign weights to each rank between 0 and 100 (as percentages) such that they sum 100 % over all ranks. One technique to assign weights is the one called  "Swinging Weights".

    Good luck. 

  • Klaus Petritsch added an answer in Employment:
    In times of financial crisis, what would the purpose of vocational education be?

    In times of financial crisis, would vocational education help students to prepare for "more and better employment opportunities" or "fewer difficulties in finding employment"? These are quotes from two different education policy documents. Could you recommend studies addressing the financial crisis and vocational education?

    Klaus Petritsch

    I would like to think the purpose of vocational teaching should at least partly address the reasons for the ongoing (and not painless fixable) financial crisis.

    If every grown-up would know e.g. that (without hyperinflation) there can never be enough money in the world to pay back all debt - given that interest is charged in the moment of fiat-money creation, we would get a lot more people thinking of alternative systems (which do exist).

    Another topic for vocational education would be revealing the fairy tale that delegating political decision making to representatives  is compatible with the idea of citizens checking their leaders (democracy). The Internet (especially block-chain technology of crypto-currencies) would today already make possible more direct forms of democracy more akin to the direct democracy they had in Athens 2500 years ago - perhaps even on scales thousands of times bigger than in those days.

    I also believe, becoming an entrepreneur in a time of affluence and an oversupply of labour,  entertainment and products, and GDP fetishism is not going to work for most people - unless they create more artificial needs.

    Ideas are needed to decentralize political and financial power systems, not to produce more stuff or even more aggressive marketing.