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  • Miguel Coutinho added an answer in Glossectomy:
    What are the pros and cons of Tonsillectomy with ultrasonic instrument?

    I have never done this before. We have used the technique for glossectomy and thyroidectomy. What is your experience? 

    Miguel Coutinho · Centro Hospitalar do Porto

    I'm used to working with bipolar and microscope , etching only the blood vessels with minimal blood loss during surgery and after surgery without further complications. I am also accustomed to the use of radio frequency with Coblator , with good results, despite the higher cost. I've tried ultrasonic instrument and see no advantages.

  • Fajri Koto added an answer in Text Classification:
    Text Classification: How can I train a classifier like SVM using a word list to classify unseen documents?

    Hi. I have a query regarding Text Classification. I have a list of words with the following attributes. word, weight, class. The class can be positive or negative. Weight is between -1 to 1. How can I train a classifier like SVM using this word list to classify unseen documents? An example in any tool is welcome

    Fajri Koto · Samsung R&D Institute Indonesia

    It seems you are using sentiment lexicon to classify the document. First you need to extract the attributes based on your lexicon. There are some ways, but the easiest is by extracting two attributes, call it as posScore and negScore that represent score sum of positive words and negative words consecutively, for each your unseen document. Then do classification.

    The other way, you also can consider, the minimum, maximum, average score for both type.

  • Hina Narayan added an answer in Culturing:
    Can anyone help me with some suggestions and recommendations for culturing immortalized oral epithelial cells?

    I am working on tert- modified OKF4, OKF6 and OKP7 cell lines.

    Hi Carl! Thanks for your response.... please could you suggest how to split the cells?... considering that we are using serum-free media, how to inactivate the trypsin? also what do you think is the best confluence (in %) to split cells and the split ratio?...i am having a tough time passaging my cells....

  • Christopher R Heier added an answer in PCR Cloning:
    How can I clone a fragment of 8 kb cut with two different Restriction enzymes?

    I need to clone a fragment of 8 kb which is cut with two different REs? Obviously it can be done into a Blunt end cloning vector after blunting (as in CloneJet PCR cloning kit of Life Technologies) but I need to again obtain the fragment by RE digestion in order to ligate with other fragment. Is it possible to clone it and again obtain that after digestion?

  • Muhammad Khattab asked a question in Glycerol:
    Could you please tell me the solvent dipolarity and polarizability (SdP and SP) of Glycerol and N-methylformamide according to Catalan scale?

    I already got a reference stating the values of most solvents, but not including glycerol and N-methylformamide. I appreciate if you could help in this matter.

  • Yuan-Yeu Yau added an answer in Honey:
    What is the major diference between C-3 and C-4 plants?

    Why is it that honey requires C-3 plant sugars?

    Yuan-Yeu Yau · Northeastern State University

    @ David,

    They should have no biochemical difference between sucrose from C3 and C4 plants. One of the differences is, as you said, C3 and C4 plants result in differences in the proportions of heavy and light carbon isotopes from CO2 (atmospheric CO2  contains 1.1% of non-radioactive 13C, and 98.9% 12C) being assimilated. See the attached classic paper. In the paper, it shows the different ratio of these carbons in C3 and C4 plants. I think it is very interesting.

    And I think the original question more focus on why almost all the honey (produced by bee) come from C3 plants. This phenomenon may give some people the misconception that honey can only be make from C3 plant sugars.

  • I want to asked why the DNA bands of PCR product and Genomic DNA appear after the loading dye on the gel ?


    Sarah Kathryn Hewitt · University of Nottingham

    Different loading dyes migrate different distances and the distance migrated depends on the agarose percentage of your gel. For example, Bromophenol blue (NEB loading dye, and many others) migrates at approximately 300 bp on 1% TBE agarose gel. Which dye do you use? Perhaps your PCR product is smaller than your loading dye tracker? (though I doubt that this is the case for your genomic DNA).

  • Robin Andrews asked a question in Earthworms:
    Earthworms vs enchytraeids?

    How to you tell a enchytraeid from a lumbricidae: the pot worm vs earthworm dilemma? I probably only need to separate out invasive Dendrobaena octaedra. from a native enchytraeid, any suggestions? Is there anything I could see in a alcohol preserved specimen? Both are small usually less than 2cm in length

  • Can anyone provide any basic research paper on the topic "Composite Finite Element Method"?

    I need a basic paper on the topic “composite finite element method”. So, I need basically some attach file such that I can download.

    Claes Richard Fredö · Qring Technology Intl. AB


    You find a nice paper on how to use microstructure models in this discussion link.



  • Nyembo Salama added an answer in 4G:
    Major differences in 4G and 4.5G wirless networks?

    Can someone identify the major changes in Release 13 and 14 pf 3GPP from Rel 12 LTE Advanced. When the networks would be deployed.

    Nyembo Salama · University of Bridgeport

    Thanks Dr. Abdul for providing the detail

  • Salam Abbas asked a question in Hydrological Modeling:
    Link climate change to ArcSWAT ?

    I start learn ArcSWAT for the purpose of constructing hydrological modelling for selected case study and my main focus is (study the effect of climate change on water quantity) could anyone tell me how can I connect climate change effect into hydrological modelling in ArcSWAT?

    Many thanks in advance,

    salam :)

  • What are the interface properties between ABS and carbon nano tube?

    Interface properties between CNT and polymer affects the elastic modulus of the CNFRP.It will be great if any one can provide the interface properties between CNT and ABS polymer.Thank You

    Flores-Ruiz Francisco Javier · Center for Research and Advanced Studies of the National Polytechnic Institute

    Please check this paper and references therein


  • Crystina Kriss asked a question in Ideas:
    Everytime I run human liver samples on our mass spec they clog our column.

    Everytime I run human liver samples, cytosolic and nuclear fractions, on our mass spec they clog our column. I use sodium deoxycholate to solubilize membrane proteins, along with FASP & desalt to clean up the samples. Any ideas what would cause this?

  • Adam Hughes added an answer in Silver:
    What are the optical properties of silver nanoparticle monolayers?

    I have found several spectra of the UVVis absorbance of silver nanoparticles in free solution (ie in a cuvette).  Does anyone have any curves that might show the transmission or reflectance of light incident on a glass slide with a silver nanoparticle monolayer?  We've done a simulation that seems to imply, depending on how the silver is affixed to the glass, that the plasmon resonance peak might actually be blue-shifted on the silver layer as opposed to in free solution.  We're having a lot of trouble finding such measurements, either on slides or optical fibers with silver nanoparticle monolayers.  Does anyone have any resources on this?

    For comparison, here are sequences of curves showing the spectral reflectance off of a monolayer of GOLD nanoparticles on an optical fiber endface from:

    Jeong eg. al http://www.ncbi.nlm.nih.gov/pubmed/23421143

    Adam Hughes · George Washington University

    Thanks!  I wonder if this blue-shift could be a problem of interpretation, at least in part?  I'll have to read up more.  We've done some simulations on our optical fiber biosensor and confirmed some seemingly odd results.  For example, the sensor response to glycerin has a response profile that peaks at around 480nm, while the gold nanoparticles on the sensor absorb mostly at 540nm.  It turns out to be completely confirmed by simulation and is a biproduce of the state of the glycerine and glass substrate and their interaction with AuNPs.  In any case, that's not to say this has anything to do about the silver blue shift....

  • Why does the Schroedinger equation for a free particle contain the particle mass?

    Classical dynamic equations for free motion of a body do not contain the mass of the body. What is a reason, why the Schroedinger equation contain the particle mass?

    Juan D. Bulnes · Universidade Federal do Amapá, AP, Brasil

    Dear Prof. Farid,
    Surely you remember that the standard Lagrangian for the free particle is only one among many possible. For example, a non-trivial Lagrangian for the free particle that does not incorporate the mass of the particle, that depends explicitly on time (t) and includes a harmonic term is as follows:
    L (x, v, t) = (x2 / 2) + xvt  -. (1 / (a2t2)).(sin (a (x-vt)))

    (this is easily verifiable)

    where 'v' is the velocity and 'a' is a parameter that has been incorporated as a conversion factor to the angle unit, expressed in rad / meter

  • Robert Tomsik added an answer in T-Test:
    What is degrees of freedom in calculating t-test or ANOVA?

    When we conduct t-test or ANOVA, then we compare the calculate value of 't' and ANOVA with the table value. For this purpose, we see the table value on two important criterion -(1) confidence interval and (2) degrees of freedom. My question is that what is degrees of freedom?

    Robert Tomsik · University of Constantinus the Philosopher in Nitra - Univerzita Konstant’na Filozofa v Nitre

    DF is number of values in the final calculation of a statistic that are free to vary. If you notice, DF number is number of respondents minus groups of comapring. For example, if you with ANOVA test compare 5 groups and you have 200 respondents,  degrees of freedom is 195.

    Good luck

  • Thomas Andl added an answer in LNA:
    How do I differentiate between DNA and RNA In situ hybridization?

    How can I be sure that my custom made LNA mRNA detection probe does not detect genomic DNA while doing RNA in situ hybridization?

    Thomas Andl · Vanderbilt University

    Good luck.  I tried once to detect transcription from repetitive sequences in the mouse and had so much trouble to get rid of the genomic DNA that I gave up. I think I treated with DNAse twice and still the negative control showed up positive. Therefore, I believe that you have to find a trick to suppress the nuclear signal in order to be able to see the little bit of transcription from these sequences. Are these RNA transcripts exported to the cytoplasm? I don't think the melting temperatures of DNA/RNA versus RNA/RNA hybrids will be good enough to design the hybridization temperature in a way to "wash" of the DNA/RNA hybrids or better preventing them from forming. I assume this had to be a tremendous difference, at least a few degrees celsius and then it may still not work due to the abundance of the repetitive sequence. The question is: how frequent is the sequence you want to detect?

    I also don't think an acidic treatment or DNAse treatment will do the trick...

    Has this been done before?

  • Kevin J. Miller asked a question in MATLAB:
    Can I perform sparse matrix operations in Matlab with single precision?

    I wrote a very nice Matlab code that solves Laplace's equation on a 3-D complicated geometry. The solver is implicit, so my systems of equations is reduced to a matrix equation. I use a sparse-enabled conjugate gradient iterative solver to solve the system. The problem is that I am running out of memory when I have a large geometry. I want to conserve memory by using sinlge-precision values. It seems rather silly to use double precision for such a simple linear PDE, but Matlab's sparse matrix library doesn't seem to support single-precision (seems totally arbitrary to me). At any rate, I was wondering if there was another sparse matrix solver, written in a language other than Matlab, that is jingle-precision compatible and fairly easy to wrap into a Matlab script?

  • Andrew Ahmed added an answer in Acne:
    Which is the single best questionnaire to study the quality of life in acne patients?

    I want to study the quality of life in acne patients by a single questionnaire to make the study procedure and statistical part less cumbersome.

    Andrew Ahmed · University of Toronto

    Why don't you get a psych questionnaire? Like a quality of life Inventory, or something of that sort.

  • Is anyone doing research on or aware of research on interventions to promote physical activity and improving exposure to sunlight?

    There is evidence from the UK to show that lifestyle factors, certain ethnic groups have vitamin D deficiency and vitamin D supplements would prevent the deficiency. However, there is limited evidence on interventions at improving physical activity for example: in winter spending some time outdoors may prevent vitamin D deficiency. Is anyone aware of such studies?

    Joan Vaccaro · Florida International University

    I did not mean to be confusing. The one publication about Finish people states that at times of higher serum vitamin D levels there is a lower prevalence of type 1 diabetes in children. For seasons with limited sunlight there is an expected higher incidence. Yes, Tausif, I agree that people with type 2 diabetes have a greater Odds of having insufficient serum vitamin D as compared to their healthy counterparts.

  • Jeffrey J Weimer added an answer in Chemical Bonds:
    Can a forward reaction rate of chemical reaction be calculated from Gibb's energies of substrates?

    The idea is to divide the equation of equilibrated chemical reaction into forward and backward part. The equation dG = - T R ln(kf/kb) into dGp - dGs = T R ln(kb) - T R ln(kf), where dG is Gibb’s energy of reaction, dGs is Gibb’s energy of substrates, dGp is Gibb’s energy of products, T temperature, R gas constant, kf forward rate coefficient, kb backward rate coefficient.
    Looking at this form I suggest the following equation:
    B + dGs = T R ln(kf), where B is some constant (may be dependent on type of the chemical bond).
    Is the equation correct? What should be behind the parameter B? For which chemical reactions has B the same value?

    Jeffrey J Weimer · University of Alabama in Huntsville

    For your proposal to work, the reaction must follow microscopic reversibility. Only elemental reaction steps do so. Therefore, your proposal only applies to elemental reaction steps. It absolutely does not apply to multi-step reactions by principle. When it seems to apply due to experiments, it is only by good fortune or serendipity.

    Adding an enzyme to a reaction system changes the overall mechanism. Even when you would perhaps be considering elemental steps, you cannot compare apples (a reaction without an enzyme) and oranges (a reaction with an enzyme) as you seem to want to do.

  • Aleksei Bykov added an answer in Wavefunction:
    How does gravity affect the Schrodinger wave function?

    How does gravity affects Schrodinger wavefunction?

  • James Leigh added an answer in Case-Control Studies:
    Why Epidemiologists use Odds Ratio at Nested case-control studies ?

    please answer with reliable references

    James Leigh · University of Sydney

    In terms of analysis, a nested case control study is the same as any case control study. in fact all case control studies could be conceptually regarded as nested within  a cohort.. Odds ratio is the effect measure because true incidence rates are not measured . The controls(referents) when their exposures are ascertained only give the ratios of the sizes of the exposed and unexposed polulations, assuming controls are selected independently of exposure. see Rothman and Greenland 2nd ed 1998 Lippincott  Ch 7 p93. and Breslow and Day Vol 1 1980 IARC sci Pub 32.

  • Samantha CW Chan added an answer in Silver Nitrate:
    How can i separate all the proteins from salt solution in a cell culture medium with bovine serum?

    I want to determine the binding of metal ions to salt and protein complex in cell culture medium .

    Samantha CW Chan · Empa - Swiss Federal Laboratories for Materials Science and Technology

    Thanks everyone for the answer!

  • How can I calculate the elastic properties of a composite (Micro mechanical approach) using FEM?


     I am calculating the elastic properties of composite using finite element method.

    The value of longitudinal modulus calculated using analytical and FEM approach are matching, but the transverse Modulus values of the analytical and FEM approach are not matching. I am attaching the paper which i am following. It will be great if any body tell the reason 

    Claes Richard Fredö · Qring Technology Intl. AB


    I have never worked this problem myself but I had a look out of curiosity and, for what it is worth, can make some guesses to your question

    • The analytical volume mixture model mixes material based on volume fraction, i.e. ignores the specific shape of the composite mixture, which is accounted for in the FE model. It appears that this assumption, i.e. ignoring geometry, is more robust for the longitudinal modulus than is the case for the transverse modulus.
    • The Halpin-Tsai model is semi-empirical, i.e. a best fit from experiments likely is used to overcome the above limitations.
    • The periodic microstructure model accounts for geometry using Fourier series. A Fourier series never explicityly match the exact function as it is energy correct, i.e. it will always err somewhere but pinpoints the total energy. In any case, from my glancing the paper, it seems to me that the match is better between FE and this model, though the match is better for some shapes than other shapes. The difference in match between shapes may be related to how well the Fourier series works for the particular geometry, e.g. a Fouries series can never catch a square wave (see the Gibb's phenomenon) but has an easier job capturing circular geometry.


    All in all, using FE would be the general method. The FE approach might be less good than analytical models for random fiber mixes, i.e. where angle, diameter etc is varied. I would expect FE to outperform other methods for explicit composite arrangements, i.e. arrangements with low variation of microstructure geometry.

    Just my 2 cents.


  • Anyone know whether there is any research on participants' perspectives of being invited to validate their own data?

    I am curious about whether when participants are shown transcripts & study reports and offered an opportunity to comment and challenge - do they ever do this? I suspect not (power relations bw researcher & participant, dominant social science "rules") ....which makes me wonder how useful it is as a way of enhancing trustworthiness of qualitative research

    Edith Steffen · University of East London

    Hi Laura,

    Your post raises some really interesting ethical questions, for example about the extent to which a qualitative analysis could be said to 'represent' participants. The function of participant validation of transcripts and reports is likely to be different depending on the methodology employed and the overarching ethical stance taken. I would assume that it increases the trustworthiness of research which prioritises participants' perspectives generally and where participants may already be involved in some of the decision-making, as in participatory research, while it might serve a more tokenistic function elsewhere. While I don't know about any examples of the kind of research you are interested in, I can recommend Miller, Birch, Mauthner & Jessop (2012) Ethics in qualitative research (2nd ed.) for further reading, as it highlights ethical issues to do with the participant-researcher relationship, particularly from a feminist perspective.

  • How can I measure the perception of innovation of academics?

    I want measure the perception of the academics in universities. Is there any survey about this?

    Asst.Prof.Dr.Mustafa Zincirkiran · Dicle University

    Thank you for your help. I will consider all papers that you suggested. We also try to develop multidiscipline scale for the innovation.

  • Can anyone recommend an instrument for measuring leadership skills?

    Why do entrepreneurship,  perseverance, emotional intelligence and effective communication link to leadership skills?

    Mohammed Nadeem · National University (California)

    Hi, Norasmah:

    Leadership measurement perhaps is vital because of bottom line benefits!

    To explain why measuring the bottom line benefits of leadership development has become increasingly important in an unstable economy, a recent research study (Hayward, 2011) highlighted ways in which Human Resource professionals can demonstrate the financial impact of leadership measurement/development programs alongside other relevant measurements, in line with organisational strategy.

    The author argued widely used evaluation models and also draws on case study material from a leading specialist insurance company, Hiscox, to highlight the importance of selecting appropriate financial measurements alongside other quantitative and qualitative evaluation methods. The Hiscox case study element of this study demonstrates the importance of selecting appropriate measures and viewing bottom line benefits as a critical element of overall leadership measurement/development evaluation. The author offers practical advice for HR professionals on how to measure effectively the bottom line benefits of leadership development!

    • Hayward, S. (2011). Connecting leadership development to bottom line benefits. Strategic HR Review, 10(1), 28-34.

    Hope this helps!


  • Lyamine Mezedjri added an answer in Bathymetry:
    Can anyone provide me a bathymetric map of the Algerian coast?


    Lyamine Mezedjri · Université 20 août 1955-Skikda

    Their is a set of bathymetric maps of Algerian coasts but not in numerical version, they are thalassa maps 

  • Dean Whitehead added an answer in Hermeneutics:
    Is there any simple explanation about HERMENEUTICS methods in Qualitative research?

    I need to develop a case study using hermeneutics method related to philosophical thinking among educators but still couldn't understand about this term and the procedure.

    Dean Whitehead · Flinders University

    Hi all,

    Some good responses. Not sure what happened with my earlier broken response - but I had meant to say that there was no 'simple' approach to hermeneutics (and certainly not from a YouTube clip) - and that case-study is not that conducive to hermeneutical approaches.