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  • Wiyada Dankai added an answer in Gene Expression:
    What is the best formula between 2^dCt and 2^ddCt for analyzing the data from stress and non-stress condition?

    Dear, researchers

    I try to study the gene expression between stress and non-stress condition, for example, I treat the sample with H2O2 at 37C for 1 h (stress condition) while the normal condition I incubate the sample  at 37C for 1 h (same as stress condition). 

    What the best formula between 2^dCt and 2^ddCt for analyzing the data from stress and non-stress condition?

    Thank you all.

    Wiyada Dankai

    Thank you all,
    Zyanya Reyes-Castillo;

    Mikhail A Gavrilin;

    Jochen Wilhelm, 

    Thank you for the useful comments,
    Now, I have many samples such as wild-type, mutant and complemented strain. Hence, I would like to compare the interested gene expression under normal and stress condition between wild-type, mutant and complemented strain. 

    Is it better if I use 2^dCt for comparing the gene expression?

    ฺBest Regard,

    Wiyada Dankai

  • Abdul aziz Jaafar added an answer in UAV:
    Is there any reference to develop an intelligent hybrid UAV capable to take off and land from unequipped runway?

    Is there any reference to develop an intelligent hybrid UAV capable to take off and land from unequipped runways.to generate product concept?

    Abdul aziz Jaafar

    Dear Kaung

    Have a look at open source UAV project  APM... I think fow low cost application... the community has mentioned a problem of using sensor for auto landing.. For take-off .. the uav concepts from this project do not incorporate that features.. but it is possible for you to introduce that feature.. 

    Good luck and have fun


  • Dejenie A. Lakew added an answer in Teaching:
    Today is International Teacher's Day. Are teachers respected in your country?

    Depending on your answer, why or why not are teachers respected?

    Dejenie A. Lakew

    This is my first time to read such a day exists. When and who declared this day to be teachers day? 

    Theoretically teachers should be respected as they provide the necessary knowledge and skills someone needs to lead a successful and productive life in society. But in practice I doubt it is not the case. The first reason is the pay they get-which makes them the lowest income members of society as respect nowadays comes from living standards.

    A teacher who lives in his vehicle or in a tiny room, will not expect respect from society and there is no any rational social members to respect such a person aside from the humanity side of it. It is when teachers get reasonable payment to make good living in society, the notion of respect will always be an illusion. 

  • Ahmed Abdelfattah added an answer in QIIME:
    What's the approximate cost of using Amazon EC2 for 16S analysis with QIIME?

    Just curious to see an order of magnitude cost estimate (for any sample size/# of runs) from someone that has used QIIME via an Amazon EC2 instance.

    Ahmed Abdelfattah

    Agreeing with Rumakanta, try to assume your run based on your free trial. each person is different based on their speed in running the commands and your internet speed for upload/download. also remember that if you cancel your account to stop paying you risk removing your data from the server. 

  • Prasanta Kumar Ray added an answer in Western Blot Analysis:
    For mGluR5 antagonists, do people prefer MTEP or MPEP? Which is better for in vitro applications?

    Which is better for in vitro applications such as Western blot analysis?

    Prasanta Kumar Ray

    See a published report on this

  • Prasanta Kumar Ray added an answer in Shigella flexneri:
    Can anyone share an exact protocol for antibodies FITC conjugation without using any commercial kits?

    I have a highly purified and lyophilized monoclonal antibodies against Shigella flexneri K13 serotype. I was wondering whether it is possible to make FITC tagged antibodies for direct immunofluorescence. And if it is, can someone please share an exact protocol for FITC tagging without using any commercial tagging kits.

    Prasanta Kumar Ray

    There are many papers published in journals all over showing as to how FITC conjugation of antibody molecules could be done succesfully.Please follow a recent method for your purpose.

  • Keisha Njenga added an answer in Cassava:
    What could be the cause of my invitro cassava plantlets change in colour to white after subculturing on Basic culture media?

    I am planning to regenerate cassava from nodes and my plantlets are turning white after subculturing in basic culture media that i have incorporated with silicon.

    Keisha Njenga

    By basic media I meant cassava basic media containing Murashige and skoog with vitamins,CUSO4,Sucrose,and gelrite. Addition was silicon to the media above was to assess the impact it would have on the growth and establishment of the invitro explants.

  • Godfried Van Moorsel added an answer in Shellfish:
    Is it possible to identify what made these marks on the inside of this king scallop shell?

    We came across some king scallop shells (Pecten maximus) during some of our sampling in Shetland, UK, which had some interesting black 'burrows' on the inside of the shell.  Some had a corresponding globule-like projection on the outside of the shell (see pictures) as well.  I'm guessing they were possibly made by a boring tubeworm but is there a way of identifying what made them?

    Many thanks,


    + 1 more attachment

    Godfried Van Moorsel

    Hi Richard

    I agree with Wayne one a polydorid worm. Around Shetland you may expect Polydora ciliata. In the Netherlands this species is known to bore in oysters cockles and mussels. Sometimes blisters are made on the inside of the shell when the worm threatens to perforate the shell.

    Some photos of borings in shells may be found in Cadée & Wesselingh 2008. From living mollusc to fossil shell: taphonomy of shells from Dutch beaches (in Dutch), see link

  • Michael Negraeff added an answer in Knowledge Exchange:
    Does anyone know of any online education program about pain management for physicians/nurses/psychologists?

    I mean, I'm looking for some model on a program not for students, but for professionals.
    Both for learning and also for educational knowledge exchange for caring for critically ill children.
    I have found some examples documented (e.g: Wolbrink, Kissoon, Burns, 2014; Jarrett et al., 2013). Someone else?

    Any contribution will be appreciated!

    Michael Negraeff

    Pain BC Society has a number of webinars on different topics painbc.ca

    University of Alberta runs a distance education certificate: http://rehabilitation.ualberta.ca/professional-development/certificate-programs/certificate-in-pain-management


  • Jean-François Gueugnon added an answer in Mutual Funds:
    How can we measure the contribution of actively managed mutual funds to market efficiency?
    There is extensive research suggesting that active management by mutual funds add little value, and more likely destroys value for the investor. Since this idea becomes more widespread, investors are now increasingly following passive strategies. There it seems that less and less investors are doing active research, and it makes one wonder when this eventually effects the level of market efficiency.

    This raises a couple of questions, such as: are there other people working on this topic?, can we measure the level of market efficiency? How many active investors do we need for an efficient market?
    Jean-François Gueugnon


    The answer is also in the definition of efficiency market.. According to the immediate, short or long term considered, this question is linked strongly or not to the cost of the market liquidity (and its definition in microstructure or not).

    Market Efficiency= Market performance / Market Means

    with : Performance = ? Means = ? In witch term (yiled, risk, liquidity ...) ?

    Sometimes, you have here a mixt with :

    effectiveness  : Market Performance / Market Goal

    All these instruments trying to measure and explain the distance between Objective and Performance (via means or the phenomena).


    P.S. : I'm mainly specialized in firm management (cash management, financial debt ....)and a bit in public management. But I know pretty well the financial markets.

  • Ricardo Zavala-Yoe added an answer in Control Systems Engineering:
    Can someone help me to find the stat equation for this problem? (without bond graph way)

    This problem same as problems in chapter 4 of Karnopp book. But in that book from the bond graph model find the state spas. I want to find this equation in normal way . 

    Ricardo Zavala-Yoe

    You could try the Euler - Lagrange equations. Apparently, your system seems suitable to be modeled with them.

  • Ameer Ahmad asked a question in Specific Gravity:
    How to find the composition of ore whether elemental or component? And which equipment is used to find the specific gravity of the powdered mineral?

    I want to know that what is best analytical testing equipment to find out the composition of Barite. Share any research paper or book to help me out. 

  • Peter Pediaditakis added an answer in Protein Extraction:
    Does anyone have any suggestion for tris-buffered phenol preparation?

    I have a protocol for preaparation of tris-buffered phenol for leaf protein extraction. in that protocol it is mentioned to prepare tris-buffered phenol from crystalline phenol. but i have saturated phenol (saturated with 10%water). shall i use this phenol or should i use crystalline phenol only? experts please clarify my doubt.

    Peter Pediaditakis

    It should not matter for proteins but will matter for nucleic acids.  A small portion of aqueous phase will go into the phenol.  The point of saturating the phenol is to fill that compartment in the phenol with aqueous media.  The tris is used to buffer phenol to insure that the "aqueous compartment" is at a suitable pH for what you are doing.  Normally, this compartment will be at a pH of greater than 7.8 for nucleic acid extraction to insure that nucleic acids do not enter the phenol which will be a little bit acidic.  I used a variant of this method to extract extremely dilute proteins.  So I discarded the upper aqueous phase where nuclei acids were and kept the lower phase where the proteins are.  Proteins go to the lower phase (phenol).  The subsequent steps I used diethyl ether to remove the phenol.  The protein would then move into the aqueous compartment that was previously n the saturated phenol.

    BTW, if this is for nucleic acids I would tell you to by pre-made tris buffered phenol.  Crystalline phenol will require a subsequent distillation prior to use to remove quinones ( oxidation products) which can attack diester bonds.  Re-distillation above 160 C is not something many labs can do nor would they want to do.

    If I may ask, what are you going after in the axtraction?

  • Sebastianus Kurniawan Hadisantoso added an answer in Piezoelectricity:
    What is the best sensor to measure range in small precision?

    I want to find the distance of an object ahead of my device. That thing will approach my device and stopped. When that object is stopped, I want to know how far that object will be but it just about just millimeters or smaller away. What is the best sensor to measure that distance? It will be fine if the sensor is contact less or not. I already have 3 ideas:

    1. Using an infrared range finder. But as long as I now the precision is not very good.

    2. Using a piezoelectric sensor. This sensor is usually used to measure force from deforming the material. Can I use the deforming properties to measure the distance of the object from my device?

    3. Using visual measurement from a camera. I can get the picture of the object ahead my device, then calculate the real distance from the picture. I am not very sure about this idea because to get picture in small object like this will need very good camera and it will be very costly.

    What do you think about these ideas? Or there is any better idea?

    Thank you very much, sorry for my English.

    Sebastianus Kurniawan Hadisantoso

    actually the object i want to is human skin, I plan to design an machine that can inject needle to human skin automatically. I want to know how far the needle need to get in for every finger placed in front of the needle. So I think using the two lightbeams won't work because the surface is not flat. Anyway, thank you for the response Fokko.

  • Mohamed Salem added an answer in Trypsin:
    How can I trypsinize sHela?

    I have two questions, I am trying to trypsinize my sHela with trypsin 2 ml for 5 minutes in the incubator, then after checking the percentage of detaching cells under the microscope, It is always low as 30% or less, so how to do a perfect trypsinization to get as much cells. Second question, If I am incubating several 10-cm culture plates, can I put them over each other, like 4 plates over each other, I am afraid they get suffocated

    thanks in advance

    Mohamed Salem

    Thank you guys so much, I  have tried what you said as putting the Trypsin in the incubator for an hour, then I used more PBS to wash my cells 3 times, then I used only 1 ml of Trypsin and incubate it for 5 minutes. Then I moved the plates forward and downward to ensure that cells are covered well by Trypsin. I was surprised how this really worked. Mose of my cells detached out of the surface. Thank You

  • Shail Choksi asked a question in Predictive Analytics:
    Hello, I am working on building the predictive analytics model for diabetes. For that, I need dataset. Can anyone help me please?


    Currently, I am working on building predictive analytics model to predict early diabetes by comparing healthy person habits and symptoms with diabetic patients.There will be few other components of my prediction (that I can not share right now) I am certain that my model and algorithms will work perfectly and provide an accurate result. As you know, data is an important part for the accuracy of the model. Therefore, I need the dataset for training and testing of my model. I have already built the concept and mechanism to provide real time prediction. I would appreciate if someone can help me getting the dataset that includes good amount attributes.



  • Robert C. Baumann added an answer in Insulation:
    How effective is vacuum insulation at high temperatures?

    Hi All,

    I am trying to assess feasibility to store energy as heat. Now, not to loose too much, it needs to be insulated, by eg a double-walled steel tank, with vacuum between both tanks, and filled with some cheap insulation material, like basalt wool.

    Can anybody help me how efficient this would be at hot ?. The highest temperature possible with cheap steel is about 500 degC.

    Best Regards,


    Robert C. Baumann

    Hello Henri,

    My previous general comment seems to cover what you are saying.

    "Any material you put between the inner and outer tanks will basically do three things with the radiation emitted by the inner tank: reflect it back, absorb it, or transmit it."

    Art this point in this thought experiment I will agree that we disagree and it would be interesting to actually do the experiment OR create a heat flow/radiation simulation with realistic material parameters.

    Practical note: putting a high surface area material such as rock wool in the vacuum will greatly increase pump power requirements and pump down times, maybe even limit the ultimate vacuum reached due to outgassing.

    Cheers, Robert

  • Professor Zhang added an answer in Blots:
    Why there is nothing in Loading control but Protein specific signal at the right size?

    Running a 10-20% Tris-Tricine blot with nuclear and cytoplasmic fraction of cell lines transfected with 4 different expression constructs.

    Got desired protein bands (9 kd) for two constructs in right size with protein specific antibody but strangely no bands found for loading control either in cyto or nuclear fraction but found bands for tubulin and Lamin B for the other two expression constructs .

    How I am getting nice bands for the protein of my interest but nothing in the control lane?

    What could be the explanation for this situation or what should I change?

    I followed the abcam nuclear fraction protocol.

    Professor Zhang

    No bands found for loading control but found bands for the other two expression constructs. Are you sure you have  followed protocol rightly? It is mostly likely to be a mistake because there is no resonable explanation accounting for this phenomenon. Maybe you have ignored some important things.

  • Emil Berengut added an answer in Manual Therapy:
    Can physical therapists actually break up scar tissue?

    There is much research in pain science that PTs don't actually break adhesions and any manual therapy that causes a release is a neurological function. I'm a little unclear if that's still the case with scar tissue

    Emil Berengut

    Ralph, if I understand your question correctly-pain modification. In oncology we're working with patients with severe scarring-both from surgery and radiation. While there's pain modulation after soft tissue mobilization- it's short term. I have no reason to believe or evidence that we've "broken" any scar tissue. In cases of manipulation under anesthesia, usually performed by physicians in the US-while there's improved range, but it creates additional scarring and long term outcomes are severely affected.

  • Mehrdad Khatami added an answer in Nanoparticle Research:
    How to stabilize bio synthesized nanoparticles?
    I have used sodium do-decyl sulphate (SDS) for stabilizing my magnesium nanoparticles but I get agglomerate within 24 hours.
    Mehrdad Khatami

    A large number of stabilizing agent reported in literature.

    I suggest you used carbohydrate like glucose.

  • Chris Leiwakabessy asked a question in Salicylic Acid:
    I am looking for a journal on the interactions between salicylic acid, plant varieties and strains of pathogens, can you help me?

    My research on the effects of the interaction between the salicylic acid, plant varieties and strains of plant pathogens. I am looking for journals on the topic of the interaction between the salicylic acid, plant varieties and strains of pathogens. Can you help me please ?

  • Alexander Obydenov added an answer in Strategic Planning:
    What is the difference between a strategic plan and a strategy?

    There are many different approaches. Is a strategy part of a strategic plan or a strategic plan elaborates a strategy?

    Alexander Obydenov

    It seems that strategic plan is a particular case of strategy. Among other kinds of strategy it can be ploy, pattern, position, perspective (Mintzberg, H., Ahlstrand, B. W., & Lampel, J. (1998). Strategy safari: A guided tour through the wilds of strategic management).

    As far as strategy realization is concerned we can use balanced scorecard or strategic change concept for these purposes. As well without any planning it could be done.

    • Source
      [Show abstract] [Hide abstract]
      ABSTRACT: One of the effective approaches to the strategic management could be that one based on the use of formal rules. Application of such rules as the main instrument should ensure the achievement of target steady state or functioning mode by managed economic system. The strategic management setup, which is a purposeful institutional change under such an approach, appears to be a separate task. The set of instruments and methods could be used in order to ensure the efficiency of such transformation process – the gradualness of implementation of developed rules; compensations; application of formal institutional alternatives consistent with the internal informal institutional environment. Attraction of participants interested in to the development and implementation of the rules could be useful as well. Self-regulation organization or self-governing firm appear to be the marginal case of such a participation. It is these organizations that possess the necessary prerequisites for fundamental resolution of the problem of "controlling the controller». The selective incentives could be applied in order to increase the efficiency of collective actions.
  • Muhammad Asim added an answer in TRNSYS:
    How can I add the information of HVAC in type 56, to creat the HVAC system in to get the information of energy consumption of HVAC system?

    Trnsys simulation studio project of desiccant cooling system.

    Muhammad Asim

    i think you can not add directly,,you need to do it through revelation type manager.

  • Mehrdad Khatami added an answer in Nanoparticle Synthesis:
    What is the origin of different colours in noble metal nanoparticles and semiconductor quantum dots?
    Mehrdad Khatami

    SPR is reason of this color changes

  • Gerard t Hooft added an answer in Foundations of Physics:
    Do you agree with Stephen Hawking's recent conclusion that black holes don't exist?
    Black holes don't exist. I published this many years ago. Cantor's Universe doesn't allow the concept.

    Stephen Hawking now came up with the same conclusion. Read: http://www.spektrum.de/news/es-gibt-keine-schwarzen-loecher/1222059

    In my opinion he is right this time. What is your opinion? Was he right then or is he correct now?
    Gerard t Hooft

    @Manuel: not the public self-corrects science, science itself does. GR and the SM are based on much more solid evidence than you seem to imagine, so that amateurs kicking at them can't make a dent. Sorry about that.

    Amateurs kick at science when they fail to grasp why real scientists are not at all interested in their own private contraptions. I hope you aren't one of those.

  • Karin Reinprecht added an answer in Business Models:
    The Business Model Canvas: What theory could identify/explain its advantages over other business model approaches?

    The Business Model Canvas is tremendously successful. But what’s bothering me is the question of WHY?

    Obviously, good marketing by Osterwalder & Pigneur is involved (workshops, blogs etc.). However, this can’t be the whole story, right? Not so many people would use the Canvas if it didn’t have any value over competing business model approaches.

    I believe the success cannot arise from the choice of the nine components either. A number of authors have proposed business model components similar to those in the Canvas but did not have comparable success.

    Rather, to me it seems to be about the visualization (visualization = the "grid/matrix" that visually arranges the nine components). But then the question is: How does the visualization make the Canvas good/useful? And which theories could help to shed light on this? Is it possible at all to provide a theoretical explanation?

    What are your ideas concerning these questions? I am looking forward to any hint or suggestion :-)

    Many thanks in advance!!!

    Karin Reinprecht

    Is Business Model Canvas successful? When I first saw it, I thought that it can maybe be used as a quick diagnosis tool and entry point into deeper analysis. I then used it for a concrete small business - and stopped mid-way. It felt to me too superficial, never coming to the really tricky/pivotal/key points. Is there research on the usefulness of the tool to practitioners/users?

  • Ahmed Abdelfattah added an answer in Microbial Communities:
    Are there other reliable free-wares for microbial community analysis?

    I am looking for other software (FREE) that are easier to use and more user-friendly? I am using MacQIIME and CLC Bio software. I want to explore and try other microbial community softwares/GUI? Any suggestions?

    Ahmed Abdelfattah

    Hi Edward,

    to my knowledge, there's no free GUI to analyze comprehensively microbial data. Qiime in my opinion is the best solution now, although they tried to do GUI of Qiime, it's not as popular and useful. 


    Illumina also provide some tools (Apps) that you can use, but very limited. 

    If I find anything i will let you know

    Good luck 

  • Fuminori Kawano added an answer in Real-Time PCR:
    Any advice on QPCR ChIP Analysis?

    I am optimizing a ChIP protocol.

    I do not understand very well how the analysis work.

    I performed the ChIP in 200 µL of Sherared Chormatin, reversed the cross link and purified my samples (PCR purification kits), and I treated the inputs (20µL) the same way I made fold dilutions to determine the best concentration of sample (1x, 2x, 4x, 16x) and used the same volume for input and sample to run qPCR.

    I performed qPCR and calculated as Percent Input Method 100*2^(Adjusted input Ct- Ct ( ChIP).

    When I use the formula above I found 7% and 14% of two genes of interested (2x diluted sample), but when I make the same calculation with the 4x diluted sample the concentration are 2% and 0,6 % respectively for the same genes.

    Someone could explain this difference? Is that correct the way that I am calculating my Percent Input (I am following the instruction from Thermo Fisher website)?

    Thank you very much

    Fuminori Kawano

    Hi Dalila,

    I think it's question of the ratio between antibody and DNA amount in chromatin. In my experience, DNA yield by IP would be drastically lowered if the rate being under a particular level. But this would be different if genes or primer sequences differed. In your test results, one gene shows over-less reaction when you reduced applied chromatin amount by 2x to 4x. The other gene seems exhibiting a reasonable result, though. I reccomend higher concentration to use for your case. I usually apply at least 500ng DNA including in chromatin for a single reaction for ChIP.

    Size of DNA fragment is also one of key factors affecting efficiency of ChIP reaction. I like to adjust 500-1000bp of mean size by sonication for ChIP-qPCR. Reaction will be weaker if this size gets smaller.

    Hope this works.