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  • Shyam Nyati added an answer in GPR:
    Need for interpretation: UNC5B gene (GPR Fold Change = 90,43) ?

    I found this results in a research about apoptosis in Lymphoma B (WSU-NHL)*, can someone help for interpretation?

    Gene 1: UNC5B (= UNC5H2 or p53RDL1) : GPR Fold Change = 90,43

    Gene 2: DDIT3 (= CHOP; CEBPZ; CHOP10; CHOP-10; GADD153): GPR Fold Change =  23,23

    Gene 3: HRK (= DP5; HARAKIRI) : GPR Fold Change =  15,93

    Gene 4: IGF1 (= IGFI; IGF-I; IGF1A): GPR Fold Change = 15,53

    Gene 5: TNFRSF1A: GPR Fold Change = 11,06

    .....

    Gene BNIP3L (= NIX; BNIP3a): GPR Fold Change = -9,31

    Gene E2F2 (= E2F-2): GPR Fold Change = -10,98

    * We used: Human Apoptosis pathway 96 StellARray™ qPCR Array ; Harbor Bioscientific™).

    Shyam Nyati · University of Michigan

    GPR is a Microsoft Excel based algorithm for Global Pattern Recognition (GPR) for PCR/qRT-PCR based techniques. If your GPR fold change for a gene is 96.45, means that the said gene is expressed at 96 fold higher level (compared to control).

    Basically you are measuring deferentially expressed genes from multiple replicates ( from at least two conditions/samples).

    See some of the links below:

    https://www.bhbio.com/BHB/(S(pbw4hguf2capymwtwa13fam5))/GUI/SP/Gpr.aspx?AspxAutoDetectCookieSupport=1

    http://research.jax.org/faculty/roopenian/GPR.pdf

    http://darwin.biochem.okstate.edu/gpap/faq.html

    http://www.biocat.com/bc/pdf/GPR%20At%20A%20Glance.pdf

    Hope this information is helpful.

  • Jen i-chen asked a question in Ligases:
    How can I compare the results of coimmunoprecipitation between e3 ligase and its substrate with or without MG132?

    If I performed coip between e3 ligase and its putative substrate with or without MG132, the substrate band would be enriched by e3 ligase with MG132. So I say that MG132 stabilizes the protein complex. This means the interaction between e3 ligase and substrate will promotes substrate degradation. Supposing that I use similar level of substrate protein for coip with MG132 or without it, after the experiment, the level of substrate will be different. With MG132, the substrate level will be higher. My question is: the enrichment of substrate with MG132 may be only caused by the higher concentration of substrate. So this result can't demonstrate that their interaction can promote substrate degradation. (Substrate may be degraded by other endogenous e3 ligases but not the one of interested) Am I right?

  • How would I know the maximum power output of a generator and How do I determine critical loading?

    I would like to test performance of generator.

    I will give it different running conditions, with some variable load. I want to find out how much power output.

    Inno Davidson · University of KwaZulu-Natal

    It is necessary to specify the type of generator - ac synchronous generator, poly-phase induction generator, dc generator, etc. Each has a different performance characteristic. For 3-Phase synchronous generator, the capability curve may be sufficient to determine that when your power angle is 90 degree and synonymous with dynamic stability limit. For practical applications, there are other operating issues that curtail such limits.

  • What kind of imperative can force quantum randomness?

    If the decision between two choices is to be made, but neither choice is preferred over the other, because there is perfect symmetry between the two, then no information separates the choices and the only decision that can be made is a random one.

    What kind of imperative can force such a decision, and does such a decision resist the imperative?

    Michael Mudurian · Navy's Space and Naval Warfare Systems Command

    Random time.

  • How can I correct the variation between my ELISA plates?

    I am in the middle of a large screen using an ELISA based assay and I find that even though I use the same standards and conditions for each plate there still exists some variation between my plates. This became more apparent to me when I ran the assay twice for the same samples (one assay showed an average of 1.6x higher results after I fitted the readings to the standard curve but the variation between the samples was similar in both the plates - the results seem to cluster for each plate). There may be many reasons for this and obviously some may be out of my control. My main question is that is there a statistical method to correct such variations between two plates (inter-assay)?

    Note: all samples are evaluated in a triplicate manner and intra-assay CV values are below 5 percent.

    Dipjyoti Chakraborty · Banasthali University

    I agrre with Wihelm but although I can understand some variation for a biological replicate, but if it a technical replicate gives much variation, that is undesireable - so if you are using the same standard concenration then there should be minimal reading variation both inter and intra plate taking into consideration pipeting errors etc. Otherwise, have a technician have a look at your machine or check with the manufacturer of plates   

  • Can you highiy recommend an excellent tooth vitality tester/electric pulp tester to me?

    I am doing a research about caries, I need to know the status of precise puip vitality , so can you highly recommend an electric pulp tester to me?

    Bernardino Isaac Cerda-Cristerna · Universidad Autónoma de San Luis Potosí

    Dear Isabella, 

    First, you should remember that an EPT does´t measure "pulp vitality", the EPT can detect if the tooth will give a responde to an electrical stimulus. Thus it does´t mean vitality, it means "sensibility" to an electrical stimulus. There´s no way to measure pulp vitality with an EPT.  To measure vitality, you should use some sophisticated techniques such as laser doppler flowmetry or pulse oximetry; these systems can measure blood flow and levels of oxygen, signs related to tooth vitality. Indeed, these systems have been considered as the "gold standard" for pulpal diagnosis. 

    Also, you should consider, based on a scientific rational, what is the best diagnostic tests for your objetive. Remember, the accuracy of a diagnosis test is based on "sensitivity", "specificity", "positive predictive value", "negative predictive value", etc. 

    I suggest first to revise the actual concepts of pulpal diagnosis and then to revise the bases of the pulpal diagnosis techniques (What do they measure? How?). After that you can choice the best test to solve your research problem. Maybe an EPT or "cold spray" (1, 1, 1, 2-tetrafluoroethane) are suitable for your objetive, but then you should re-consider to measure "sensibility" but not "vitality". 

    I suggest to read these articles: 

    "Identify and Define All Diagnostic Terms for Pulpal Health and Disease States" http://www.jendodon.com/article/S0099-2399(09)00793-6/abstract

    "Review of pulp sensibility tests. Part I: general information and thermal tests"

    https://www.researchgate.net/publication/45099950_Review_of_pulp_sensibility_tests._Part_I_general_information_and_thermal_tests

    Best regards.

  • Vijay Bhaskar Semwal added an answer in ANFIS:
    How memberhip function equation updated after bacprogation in matlab?

    actually i want to know how membership functon equation changes. for example in triangular memberhsip function for half portion, it is written as :

    x-b/b-a , where x is input and b is mid point of triangle and a is starting point of triangle, now how this equation modified after each epoch.

  • Shuang Zhu added an answer in Real-Time PCR:
    In RT-PCR, only one peak occurs in negative control with only primers?

    I ran a negative control with only primers in RT-PCR, but one significant peak occurred in melt curve. Then i tried running it with cDNA, the peaks in negative control is lower(Tm) than peaks with cDNA sample.

    In attached files, 'negative control' contains only negative controls with two primers. and in '050215-testify with negative control', the first line(Line A) are negative controls, and second line(Line B) are with cDNA samples.

    The sequence of every primers are showed in 'primer sequence' file. And the amount of reagents are showed in 'experiment info' file.

    Thank you very much!

    Shuang Zhu · Seoul National University

    Dear Prabu Paramasivam,

    Thank you very much for your help. I'll perform another PCR experiment following your direction ASAP. 

    And sorry for that the files I uploaded can't be opened..I was so inconsiderate. Here are the pictures captured from the PCR results and data in excel file. Thank you very much!

    Best wishes,

    Shuang

  • Why electromagnetic field propagates via void vacuum?

    Water wave propagates via the water. Sound wave propagates via matters in solid, liquid or gas states. It is pretty logical.

    "Electromagnetic field propagates via void vacuum" is commonly accepted. In this case, void vacuum is media for light. If vacuum is true void, why it can be a media for carrying electromagnetic wave? Can you provide a logical answer?

    Akira Kanda · University of Toronto

    Ziliang,

    So, we have done it. We have no reason to believe that classical addition of speed has to be changed. Classical physics predicted MM results. So, let us wonder why we have to consider CSL which leads to contradictions.

    Are physicist all illogical? Where does physics stands. They may say, experiments. Ah, pity. The MM experiment lead them to the wrong conclusion. Illogical contemplation upon the correct experimental result lead the entire physics into pure insanity.  We now are blessed by Mr. Kaku Michio's fantacy world. Karl Sagan was not enough for those illogical thinkers. MM result wrongly interpreted lead the humanity to understand sprit and our brain through CSL.

    There seems to be nothing they can do to rebut. Name calling, personal insulting and troll game of voting down without expressing any scientific response.

  • Eric B. J. Harris added an answer in Amines:
    What is a suitable method to remove water from an aqueous amine solution?

    I have an aqueous amine, about 3 ml I would like to remove the water, what is a suitable solution? Is it enough to use anhydrous sodium sulfate? Or should I extract my sample with organic solvent?

    Eric B. J. Harris · Australian National University

    The half life for reaction of amines with DCM isn't of significant concern for the length of contact you might have for extraction and solvent removal (10-20 minutes), with the potential exception of quinuclidine based on the paper. Likewise for the formation of amides with ethyl acetate. If you do have some concern about the nucleophilicity of the amine then use diethyl ether or THF for the extraction.

  • What is the difference between knowledge source and knowledge base ?

    I know the answer and explain it in informal way. I need to help to explain in paper with clear explanation (academic way). 

  • Myra Locquiao added an answer in School:
    Does too much of schooling leading to lack of (failure to apply) commonsense?

    Education

    Schooling

    Myra Locquiao · Lorma Colleges

    YES and NO. yes, because at times due to so much knowledge earned from school people tend to over rationalize things and tendency is they lost commonsense. no, because commonsense is innate. we have it all and it is available all the time...its just a matter of picking it up and utilizing it.

  • Albert Manfredi added an answer in Chips:
    What is a decoupling capacitor and how do I know if I need one?

    What is a decoupling capacitor (or smoothing capacitor as referred to in the link below)?

    How do I know if I need one and if so, what size and where it needs to go?

    This question mentions many chips needing one between VCC and GND; how do I know if a specific chip is one?

    Would an SN74195N 4-bit parallel access shift register used with an Arduino need one? (To use my current project as an example) Why or why not?

    I feel like I'm starting to understand the basics of resistors and some places they're used, what values should be used in said places, etc, and I'd like to understand capacitors at the basic level as well.

    Albert Manfredi · The Boeing Company

    With respect to the power connections to an integrated circuit or really any active circuit element, I would add that the local decoupling capacitor is used to attenuate any ripple remaining AND to remove any noise the power trace may have picked up along its path. This cap is meant to shunt to ground any of this high frequency noise, immediately before reaching the circuit element.

    Like Kristinn Andersen says, larger capacitors used in the power supply circuit are often not good at removing high frequency ripple and noise from the power trace. So that, and also induced noise, has to be managed. I've used both. A small ceramic cap in parallel with the each filter capacitor in the power supply, plus that local decoupling cap at each active device's power lead.

  • Thangaradjou T. added an answer in Gracilaria:
    Can someone provide help in Isopod identification?

    We are working on epiphytic infestation of seaweeds, the following animal causes extensive damage to Gracilaria spp. (Gracilaria edulis, G. dura) due to its attachment and grazing. Could any one help me in providing its taxonomic identity? The photographs of its dorsal and ventral view are appended.

    Thangaradjou T. · Centre of Advanced Study in Marine Biology

    Dear Dr. Vibhav,

    You can contact Dr. Ravichandran (sravicas@gmail.com) or Dr. K. Raja (k.raja722@gmail.com) for this matter. They are good in identifying the species. 

  • Matthew Clare added an answer in Standard Error:
    How to estimate error on statistical measures?

    I am working on statistics taken on samples, about which I cannot assume any given distribution shape. I have the need to establish an uncertainty budget about these measurements; I still have some doubts about what I'm doing.

    - The error on a mean can be estimated by the standard error, i.e. the sample standard deviation divided by the square root of the number of samples; is this always true, irrespective of the underlying distribution?

    - Is there a way to estimate the error on the sample's standard deviations, irrespective of the underlying distribution?

    Matthew Clare · Lancaster University

    Jochen, 

    I do apologise for providing an answer. However I'm right in what I said, as were you when you said it is approximate and assumes normal distribution of the sample. Never did I suggest that it is perfect, so don't ridicule like that.

    Next, if you are doing an experiment, I hope that you are using more than 2 pieces of information. However, and please bear in mind that my knowledge of pilot whales is very very limited, but actually if you were to use 4 pieces of information you'd be looking at x/2 rather than x/1.41 so you'd have a smaller SE and can assume that your result is more accurate. But from your data it would be impossible to prove a normal distribution and the standard error would be an inappropriate test, because as you said "When the data distribution is far from being "normal" and the sample size is not really large, then the approximation of the sampling distribution by the normal distribution may not be good enough. In this case the standard error is no good or meaningful measure of the uncertainty of the mean estimate."

    But the major assumption of the SEM is that your sample contains fewer data points than the entire population. It is described as 'the error in the sample mean with respect to the true mean'. And it has been proven that it is an underestimation several times, and the underestimation of your 2 point sample is roughly 25% whereas in 6 data point, the SEM only underestimates by approx 5%, as shown by Gurland and Tipathi (1971). The more data points in the sample the better, assuming you can prove normal distribution.

    Hope that clears up your point Jochen. 

  • James F Peters added an answer in Dynamical Systems:
    Seifert Conjecture Via holomorphic foliation?

    Seifert  conjecture says a nonsingular vector field on S^3 has at least one closed orbit. This conjecture is disproven in various smooth categories.

    Now  my question :

    Can one give an alternative  counter example  to  Seifert conjecture  in the following way:?

    A polynomial vector field on $C^{2}$ defines a one dimensional singular holomorphic  foliation. So we have a two dimenional real foliation of R^{4}-singularities. Is there an example of such foliation which is transverse to S^{3}\subset C^{2} and the corresponding one dimensional foliation of S^{3} disproves the Seifert  conjecture? 

    James F Peters · University of Manitoba

    This a good question.

    A good place to start in answering this question is

    J. Etnyre, R. Ghrist, Contact topology and hydrodynamics  II: Solid tori:

    http://www.math.upenn.edu/~ghrist/preprints/tubes.pdf

    This paper has good set of references to work on the Seifert conjecture.   In addition, it is observed that, for flows of arbitrary regularity, there is "too much room" to have a topological forcing theory (p. 1).   Hence, many constraints are required, many of which should be geometric in nature.

    Another way to state Seifert's conjecture is given in

    J.R. dos Santos Filho, M.F. da Silva, Global solvability for first order real linear partial differential operators, J. of Diff. Equations 247, 2009, 2688-2704:

    http://ac.els-cdn.com/S0022039609003283/1-s2.0-S0022039609003283-main.pdf?_tid=d5a78cb6-f1ee-11e4-80da-00000aab0f26&acdnat=1430697061_b9c722303ae22bfc9ed738bd5f8d4377

    Seifert conjecture: Every smooth vector field on the 3D sphere has a periodic orbit. This conjecture was proved to be false by P. Schwitzer for $C^1$ vector fields and K Kuperberg in the $C^{nifty}$. It has also been shown to be true for a real non-singular field on $\mathbb{R}^3$ such that (b.2) $\not\Rightarrow (a), p. 2690.

    It shown that the Seifert conjecture  is true for the restricted class of Reeb vector fields in

    C. Abbas, H. Hofer, Holomorphic curves and global questions in contact geometry, 2006:

    https://math.berkeley.edu/~simic/Home_page/Hofer_book.pdf

    See Ch. 6, starting on page 113, on periodic orbits of the real vector field.

  • Hatem A Abou-Ouf asked a question in Bioinformatics:
    How to get the chromosomal location of a list of genes?

    I am looking for a bioinformatic website or tool to get the locations of a list of genes but in one shot instead of doing it gene by gene. Is there a way to do this? Also, If you have R script to do so, please share. 

    Thanks

  • Gabriel Costa asked a question in EPANET:
    How to solve some EPANET simulation errors?

    Hi there, I drew my hydraulic model already, but I´m trying to figure out how to deal with some errors along the way that are preventing my simulation to work. One of it is the error 233 which states that some nodes are closed. What does that mean? How can I proceed?

    Thank you in advance for the help.

    Gabriel

  • Is the remark of Richard Feynman (I think I can safely say that nobody understands quantum mechanics) still valid or acceptable?

    Regarding our current understanding of quantum mechanics, especially the interpretation of the theory of measurements in terms of parallel universes.

    Theoretical physics, quantum mechanics, Fundamental physics 

    Luiz C. L. Botelho · Universidade Federal Fluminense

    Dear Yuri and Kare Olaussen

    This kind of study "one particle state " (or whatever equivalent !) for the Dirac Equation may be important to write a not definitive obtained  Path integral for the Dirac equation (the most important problem in Modern QM , in my humble opinion ).-
    Luiz.C.L.Botelho. . A Fermionic Loop Wave Equation For Quantum Chromodynamics.. Physics Letters. B (Print), v. 169B, p. 428-431, 1986. 

  • Ashish Patankar asked a question in Virtuoso:
    How to calculate the area of the circuit designed using Cadence Virtuoso 45nm?

    I am able to find the delay and the power calculations using HSpice. But I am not getting how to compare area of two circuits. Please help me out

  • Timothy Keiffer asked a question in Nocodazole:
    Any way to detach bound proteins from microtubules in vitro from a nuclear extract?

    Is there a way to detach proteins from microtubules (spindle microtubules) from a nuclear extract in vitro?  I've tried to do this in vivo by treating living cells with nocodazole before extraction, but this did not cause significant release of my protein of interest into the supernatant.

    The catch here is that I have to do this without detergents.  

    Any advice about this detachment in vitro would be greatly appreciated.  Thank you.  

  • How are antibodies linked to gold nanoparticles?

    Antibodies are crucial to target cancer cells, how they are attached on gold nanoparticles??

    Ramya Chandrasekaran · Monash University (Australia)

     EDC/NHS chemistry is another way to attach Abs to gold NPs. 

  • Mariza Costa-Cabral added an answer in Downscaling:
    Does anyone know about using the BCSD method to downscale GCMs output?

    Dear all,

    I want to use the BCSD method to downscaling monthly GCMs output. I have this question that, in the quantile-based mapping (QM), DO I have used only tow time series data included the observation and the GCM simulation in base period?

     In the other words, do I have to Create CDFs and quantile mapping for GCM output in base period and observation data sets? Do not need to use the GCM output in future?

    Pleas guide me

    With best regards

         
    Mariza Costa-Cabral · Northwest Hydraulic Consultants

    Equation 1 and 2 are correct.  That is, the future period GCM simulations are modified in the same way as the historical period GCM simulations.

    There's a problem, of course, when the future period has values larger than the historical maximum, i.e., larger than max(Xhis).  For that you need to use some type of extrapolation.  Maybe for your application the extreme values are not important, and the choice of extrapolation matters little.  

    If it does matter, then you could consider fitting an extreme value distribution to the upper tail of Xhis.  There is of course a great deal of uncertainty associated with estimating the parameters.

  • What is (are) the difference(s) between public health and community health?
    Some perceive it as the same (semantically) while others view it as different in principle.
    Dean Whitehead · Flinders University

    And back we go again to the cyclical confusion. using tyhe terms interchangeably in some cases - but not others. I doubt that there will ever be a consensus between the two terms

  • Akira Kanda added an answer in Set Theory:
    Is the set theory (ZFC) consistent?

    Nowadays, the consistency of theories is not demanded and in alternative we search for relative consistency. In the future things may change. In particular, in the answer 70 and more easily in answer 76, it was proved that set theory is consistent as a result of a relative consistency. There were published several datasets proving the consistency of set theory. In the last times it was publshed a paper in a journal, without success, since there is some inertia concerning the acceptance of the consistency of NFU set theory.

    Akira Kanda · University of Toronto

    Jaycov,

    For more than a century, a religious war has been fought on the MM experiment which changed the shape of entire physics. Despite all of this, we have had no decisive argument to explain their results. The war between mainstream physics and aether theory split physics community into two mutually hostile groups continuing this endless shouting match which tarnished the reputation of Physics. Under this situation, reasonable thinkers will start reexamining the experiment itself from different view point, not just that of the precision of measurement.
    Here we will show that MM experiment was wrongly interpreted leading to the catastrophe which destroyed 20th century Physics. MM wanted to check if the speed of light will be affected by the speed of the emitter and receiver of light. To do this, there was a known difficulty to them. To measure the speed of light, we must set the emitting point and receiving point very far away because of the high speed of light. Then we must synchronize the clocks at each end to do the measurement. Due to he large distance, we must use light (em wave) signals to do this. This means that light speed measured in this way always is the same as the light speed we assumed to synchronize the clocks. To conquer this difficulty of vicious circle, MM used one clock and mirror to reflect the light back to the sender.
    They thought that in this way, if the whole apparatus of this two way light speed measuring is moving, we could detect the effect of this motion in their measurement of the speed of light. If so, by placing the apparatus in align with the direction of the motion of our planet in the cosmos, we could be able to detect the difference in the measurement of the speed of light in this direction and in all other direction. The outcome of their experiment was negative. The speed of light measured in all possible directions they could test was the same. This lead to the axiom of the CSL which says that the speed of light is constant c in all inertial frames. Adding this axiom to the axioms of Galilean Relativity Theory, Einstein created the Special Theory of Relativity.
    Here we will show that MM's prediction that the speed of the motion of the apparatus will appear in the measurement is false. Assume the distance between the emitter of light and the reflecting mirror is d. Let the apparatus of this length d move with speed v. Assume light is emitted towards the mirror with speed c. Then it is moving towards the mirror with speed c+v. Remember that MM was operating on the classical theory and tired to find the effect of the classical addition of speed. Assume it takes time t to reach the mirror. Then we have

    d+vt=(c+v)t

    as the mirror moves distance vt. Thus we have

    d=ct.

    Now consider the reflected light. As the mirror is moving with speed v, the speed of light going back towards the emitter is c-v. Let the backward journey takes time t′ to reach the approaching emitter. Then as the emitter approaches distance vt′ towards light we have

    d-vt′=(c-v)t′.

    Whence, we have

    d=ct′

    from here we conclude

    2d=c(t+t′).

    This means that we fail to detect the effect of v on the speed of light.
    All of this says that classical theory which allows the Galilean addition of speed c+v and c-v fails to detect the over all effect of v on the speed of light. So, MM result is completely consistent with the classical physics and there is no need for abandoning classical physics on this ground.

    <remark/>Intuitively speaking, the effect of v as c+v is cancelled because the mirror moves with speed v. Also the effect of v as c-v is cancelled because the emitter moves towards the mirror with speed v.

    In conclusion, as it is our fate that we have to use reflected light to measure the speed of light, it is impossible to detect the classical addition effect of the speed of light and the speed of the emitter of light.
    One of the major source of confusion here was Maxwell's ill fated idea of aether. Treating light as wave which travels through a medium called aether is not acceptable. As we have discussed, aether is an "ontological" interpretation of the abstract "mathematical" object called em fields. The problem is that as em field itself does not exist in reality, it is just a metaphysical fiction to make calculation easier, there is no such thing as aether as physical reality. This made it so difficult to cut down to the essence of the MM's experiment. Indeed this confusion clearly appeared in the following communication from Prof. Karl Olesen [Olesen] which appeared in Research Gate:

    Regarding the MM-experiment, the situation you describe does not correspond to the experiment, where the mirrors are at rest in an inertial frame moving with velocity v relative to the (hypothetical) ether. Hence the light round-trip time, calculated according to non-relativistic physics, becomes

    T_{tot}=d/(c+v)+d/(c-v)=(2d/c)/[1-(v/c)∗∗2]

    The situation you analyze corresponds to the case where the mirrors are moving together with the ether, as observed from the frame above.

    As we stressed, aether is a fictitious entity which has no physical existence. There is no such thing as the distribution of electric force per unit charge. To begin with force does not distribute. It acts upon a point object. So, there is no such thing as aether which is an ontology for fictitious em field.
    Moreover, Prof. Olsen fails to recognize that the issue is not the aether but purely kinematic issue of if classical addition of speed c+v and c-v can be detected using two way path experiment of MM. The answer we presented is negative. Physicist at that time are as confused as now. They did not realize that the issue had nothing to do with aether.
    This argument holds for not only light but also any object. If we replace light with a ball and mirror with a wall, then exactly the same argument holds. By two way experiment, we can not detect the effect of v on the speed of the ball. But in this case, we can use one way measurement method to measure the speed of the ball. Then we can detect the speed of the ball as c+v where c is the speed of the bail and v is the speed of the emitter of the ball.
    Prof. Thim of Lintz University (in a private communication) pointed out that it may be possible to replace the two way measurement of the speed of light by making the one way measurement which synchronizes two clocks using mechanical means. He told the author that recent mechanical engineering created near perfect solution to shynchronization of timing of the ignition problem in automobile industries. When I asked him what about the precision of clocks to match the precision of synchronization mechanism, I received no response. As we make the distance between emitting point and receiving point very short to facilitate such synchronization mechanism, time interval between emission and reception becomes extremely small and we certainly have not clocks which can do the job, have we? But Prof. Thim is correct. One way measurement of the speed of light is theoretically possible. It is the matter of engineering. But obviously, we have not such technology and what we need is a trust worthy empirical result for the claim that addition of speed v and c yields the speed c+v.

    1.This problem pauses some serious challenge to the empiricism. MM and relativists made some hasty decision based upon empirical result that we "can not detect" the effect of the speed of the emitter and receiver of light upon the speed of the light emitted. They thought that all of this implies that it is the nature of light not to be affected by the speed of emitter and and receiver of it.
    2.Empiricism basically assumed that it was almighty. Empiricists thought that empiricism can deliver final verdict to theoretical predictions. Philosophically and logically this claim was refuted by B. Russell and Kuhn. The former pointed out that all empirical refutation of a theory is logically invalid as it uses the theory to be refuted to device the experiment. Kuhn pointed out that one can not experimentally refute probabilistic predictions due to the large number theorem.
    3.What is interesting in this development is that finally theoretical physics started to produce serious "negative results" which are worthwhile to be studied seriously. The first such result was the discovery that one can not measure the speed of light in one way emission. This result however was not taken seriously enough. Physicists do not like negativity. So, they developed an alternative way of reflected light measurement and forgot about this negative result. They had absolutely no idea that this would haunt them later.
    4.In mathematics, negative results are more appreciated than positive result because the purpose of mathematics is not to get number correct. The purpose of mathematics is to understand. Negative results tend to tell us more about the theory we are working on. In mathematics, most of the negative results were obtained by Cantorian diagonalization which leads to contradiction. It is interesting that in physics, it seems not to be the case. The result discussed here involves no contradiction.

  • Klaus Harzer added an answer in Triglycerides:
    Can someone help with a calculation of triglyceride amount in liver tissue?

    I extracted lipids using Folch technique and evaporated the chloroform/methanol mixture and resuspended the lipid in 200-uL of DMSO. I then determined the concentration of triglyceride (mg/dL) using an assay kit. To determine the amount of triglyceride (mg), do I multiply the concentration by the original sample volume (before evaporation) or the resuspended volume. I am slightly confused as I have seen others multiply the original volume.

    Klaus Harzer · University of Tuebingen

    Your confusion is understandable. If you determine the triglyceride concentration in the reduced volume (200 µl), you may take the determined "x" mg/dL = "x" mg/100 mL = "x" µg/0.1 mL = "x" µg /100µL = "x"/100 µg/µL, and multiply the "x" by 200, so, you have all triglyceride in the 200 µl, but as µg.

    Another question is whether all of the originally extracted triglyceride has been recovered in the 200 µL, but I think you are sure about this,

    K.H.

  • What's the logic behind the calculation of standardized weight in cases of multiple regression?

    I want the logic how we are calculating these values mathematically. As we know that by using  spss we are getting it directly? 

    Kumar Banerjee · University of Roehampton

    Ramendra, thank you for starting a thought provoking discussion on a topic that is a source of debate to many individuals in epidemiology and other fields.

    Kumar