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  • Rink-Jan Lohman added an answer in Animal Studies:
    In animal study which gender and age of sprague dawley rat is preferred ?

    As I have seen in the Journal papers about the gender specification.

    Rink-Jan Lohman

    rats are larger thus provide more tissue, and express disease symptoms more readily. Mice generally don't show any normal sickness behaviours until it is too late. Rats are also usually easier to handle and measure symptoms.

  • Mohamed El Naschie added an answer in Gravitation:
    In GR, can we always choose the local speed of light to be everywhere smaller that the coordinate speed of light? Can this be used in a theory?

    It seems that many, if not all, solutions of Einstein's equations, such as black holes and grav. waves, can be given coordinates x\mu in such a way that the local speed of light is always slower than the coordinate speed of light. Think of gravitational lensing: the index of refraction of a gravitational potential always seems to be >1, in practical examples, so a gravitational potential slows light down, and never speeds it up (if coordinates are chosen carefully). This wouldn't be true for a negative-mass Schwarzschild solution, but that seems to be outlawed in nature.

     Now this was only a conjecture, I have not attempted to prove it. How would a rigorous mathematical theorem be formulated? And did anybody - and here I mean a wise person, not the average blogger - ever try to do something interesting with this observation? Like constructing a “hidden medium” for curved space-time?

    Mohamed El Naschie

    Dear Prof. ‘tHooft,

    Let me first say that I appreciate it very much, surely like everyone on this page of ResearchGate, that you take the time and make the effort to discuss with us your most inner and important research ideas.  This is really in keeping with your proverbial modesty but then again it is not only a matter of modesty and I pray to God or such higher instance that you keep your health and strength for the benefit of all of us.  The point you highlighted about this mysterious and yet not so mysterious medium is truly the crux of the matter.  I could say from your question as well as your few additional comments and remarks that you already sensed, if not solved, probably the most basic problems connected to the greatest brain teaser that modern physics encountered by which I mean the black hole information paradox.  I think I could have a few ideas in this respect which you may or may not accept immediately.  Never the less not forgetting the distance between us in knowledge and experience in mathematical and theoretical physics, I am a little bit hesitant to express these opinions here, in the open, and want to work on it a little bit longer particularly because I know that you are a formidable opponent, mathematically speaking and not easily swayed by hand waving arguments.  So let me just summarize what I said: you are definitely talking about the most important, so far overlooked or not properly solved issued in fundamental physics and I would like to come back to the same points hopefully very soon but of course it is a matter of scale as to what soon means.  At the beginning of the paragraph I alluded to the higher instance.  Of course I know you do not believe in it but then again it would not harm because quite honestly I am not sure either but I always say to myself what Heisenberg and Carl Friedrich Weizsäcker told themselves, it could not harm and in fact it may be useful at least in our case.

    With my best wishes to your good self and family.  Mohamed El Naschie

  • Sandi Kartasasmita added an answer in Anthropology:
    Who would like to cooperate with us in a large-scale cross-populational research project?

    Dear Colleague,
    We would like to invite you to our new, large-scale cross-cultural research project.
    Our previous research projects, conducted in 53 study sites, turned out to be a great success. One of our manuscripts (from a first project) was published in Journal of Cross-Cultural Psychology, other from the new project is currently under review in the same journal, one will soon be submitted to the Journal of Marriage and Family, and three more papers are in the final stages of preparations. Thanks to our efficient team work we now collaborate with, e.g., David Buss.

    It is more or less psychological study, bu we would like to invite to coopaeration scientists from all fields of social or biological sciences.

    This time, we plan to conduct six studies.
    a) Sexual Morality Project
    b) Comparison of daily life touch between countries
    c) Creativity study
    d) Love study
    e) Mate study
    f) Facebook study

    Now, we have collaborators from +- 60 countries (see list below). New collaborators from                                   - O T H E R - countries are WELCOME!

    Algieria, Argentina, Australia, Austria, Belgium, Brazil, Canada, Chile, China, Costa Rica Croatia Cuba Czech Rep Denmark Estonia Etiopia France Georgia Germany Ghana Greece Hong Kong Hugary India Iran Ireland Italy Japan Kenya Korea Latvia Lebanon Lithuania Macedonia Malaysia Malta Mauritius Mexico Nepal Netherlands New Zealand Nigeria Norway Pakistan Peru Philippines Poland Portugal Romania Russia Salvador Slovakia Slovenia
    South Africa Spain Sweden Switzerland Turkey Uganda UK Ukraine Uruguay

    Sandi Kartasasmita

    Piotr, very interesting research. I will Join with you research

  • Hari Pandey added an answer in MATLAB:
    How can I calculate expected value by MATLAB?

    I want to calculate expected value a phrase that contained a random variable whit exponential distribution (power gain channel), I don’t have probability function for this phrase. How to calculate expected value by MATLAB? , find attachment as follow.

    my variables in attachment are GST0,PR and  GST1,PR , these have same exponential distribution and same mean.

    Hari Pandey

    .   E(X) = x1P1 + x2P2 + x3P3 + . . . + xnPn.

    E[x]=∑xif(xi) where f is PDF (probability distribution function for variables (x1,x2,..xn)

    just write a simple forloop i=1..N, and add, if you have probability distribution function

  • Thomas I. Madura asked a question in Astronomy & Astrophysics:
    Will you help bring astronomy and astrophysics to the visually impaired?

    For details, visit:


  • Matt Lee asked a question in Noise:
    Have anybody know the reason?

    work on LTP slice, Have 1 hz noise when liquid flow, but noise was gone when liquid flow Interrupt, have anybody know the reason?

    Thank you.

  • Jacques Lavau added an answer in Quantum Mechanics:
    How much time does an electron need for impressing a photographic plate? Does this datum speak in favor of full/empty waves?

    Consider the following experiment: a source of slow electrons emits in the direction z wave-packets with a group velocity 1000Km/s. The wave-packets are of Gaussian form in all three dimensions, with 0.1cm width. We pass the beam through a beam-splitter with such a small transmission coefficient that there remains on average 1 electron per wave-packet. The transmitted part of the wave-packets illuminates a photographic plate.

    From these data there results that the wavelength of the electrons is of the order of 10-7cm=10Å, and that a wave-packet crosses the photographic plate in 10-9s.

    The question is: how much time is needed for an electron of such a velocity to destroy a molecule of the photographic plate? Probably much less by orders of magnitude. Then, could it be that this fact tells us that the wave-packet is mostly ineffective (empty wave) and only a small part inside it (full wave) impresses the plate?

    Jacques Lavau

    It seems you are living under illusions. When you emit a burst of electrons, they never become a wave, with a phase. They are fermions, each in a different state, all with slightly different energies, momenta, frequencies, directions and phases. Your gaussian shape is only statistical for the burst.

    If your beam splitter stops or diverts most of the electrons elsewhere, on the meager beam your initial burst is only sampled by very few electrons, say just one electron. How such a meager sampling could conserve the initial bulk (length, duration and width) of the original burst ?

  • Irene Lim asked a question in Lysis Buffer:
    What is the minimal time for the slides to incubate in lysis buffer for comet assay?

    From my findings, I found that it's 1 hour. Is there any protocol has less than1 hour?

  • Ng Kim-Soon added an answer in Lean Manufacturing:
    Which Lean manufacturing tools can we use in semiconductor industry ?

    Lean Manufacturing Tools possible to use in semiconductor industries ? 

    Ng Kim-Soon

    There are free videos shared and available at: http://www.tpslean.com/leanvideos.htm

    Check these out and probably will give a better grasp on leans concepts and its implementations.

  • Ritesh Raval added an answer in Neurotoxicity:
    What are the best ways to assess neurotoxicity of a new drug?

    hi what are the best ways to assess neurotoxicity of a new drug? thanks 

    Ritesh Raval

    many thanks  for the replies. appreciate the help

  • Marina P. Banchetti added an answer in Greek Philosophy:
    Verificationism has the aim to find a link between propositions and experience. What are the propositions verifiable and why?

    Verificationism (according to Wikipedia) is an epistemological and philosophical positioning that considers necessary and sufficient a criterion of verification for acceptance or validation of a hypothesis, a theory or a single statement or proposition. Essentially the verificationism says that a statement, added to a scientific theory, which can not be verified, is not necessarily false, but basically meaningless because it is not demonstrable at the empirical evidence of the facts. There could in fact be multiple statements inherently logical for the explanation / interpretation of a certain phenomenon, which, however, in principle only one by definition is true.

    Nonsense does not mean false; only its value of truth can not be decided and then such a proposition can have no claim to be cognitive or foundational in scientific theory. It is defined a proposition any statement that may be assigned a truth value (in the classical logic, true or false). A proposition for which it is not possible to attribute this value is therefore a statement devoid of verifiability and so, for this kind of epistemology, not with any sense, and finally to be eliminated as mere opinion or metaphysical proposition. Verificationism is usually associated with the logical positivism of the Vienna Circle, in particular to one of its greatest exponents, Moritz Schlick, whose basic thesis can be summarized as follows:

    The propositions with sense are those that can be verified empirically.

    Science through the scientific method is the cognitive activity par excellence, since bases the truth of his propositions on this verificationist criterion .
    The propositions of metaphysics are meaningless as they are based on illusory and unverifiable concepts .The propositions of metaphysics, says Carnap, express at most feelings or needs.
    The valid propositions are, as had claimed the English empiricist Hume, the analytical ones, which express relationships between ideas (like mathematical propositions), and propositions that express facts (such as the propositions of physics). Math, as logic, does not express anything of the world, it should not be empirically verifiable, but must serve to concatenate propositions among themselves those verifiable and meaningful to give them the character of generality that is missing for the contingent propositions.
    • The purpose of philosophy is to perform a critique of knowledge in order to eliminate all nonsensical propositions that claim to be cognitive. The philosopher must be able to perform on the language both a semantic analysis (relationship reality-language) and a syntactic analysis (ratio of the signs as they are linked together).
    Verificationism has as a structural basis to find a connection between statements and experience, that is, sensations that give meaning to those. This connection is called verification.

    The epistemological attitude that gives rise to verificationism, can be found within the history of philosophy and science as early as the Greek philosophy, to Thomas Aquinas passing by William of Occam, and English empiricism, positivism and Empiriocriticism of Avenarius and Mach.

    According to English empiricism (whose leading exponents can be considered Locke, Berkeley and Hume) the only source of knowledge is experience.

    As Berkeley says, in fact, "the objects of human knowledge are or ideas really impressed by the senses or ideas formed with the help of memory and imagination composing or dividing those perceived by the senses." So there is no other way of formulating sentences or judgments from the data of experience and the only way to verify the truth value is still using experience. The judgments that are thus based on data that can not be verified through experience do not have sense and are therefore to be rejected as unscientific.

    A position that seriously reflects the consequences of empiricism is the version of Hume, who, considering that only experience can provide the truth value of a proposition, rejects all of them that claim to have universal validity. A law becomes true only if verified, but once it is verified, through experience, nothing can guarantee that the experience will occur whenever you present similar conditions that made it possible. The verification of an empirical proposition is always contingent, never needed. Difficult for Hume, therefore, is to give a definitive foundation to the same science in the traditional sense, i.e. as a set of knowledge that be certain and necessary.

    Sciences, says the positivist Comte, must seek the immutable laws of nature and as such be verified regardless of any contingent experience that shows them to senses or should occur whenever the law so provides.

    Some positivists (principle of verification ‘strong’) note, however, that the principle of verifiability makes significant some metaphysical judgments, such as "The soul is immortal." Indeed, there is a method of verification and simply “wait a while and die”. To avoid that statements of this type can be equipped with sense, it is processed a stronger version of the principle of verifiability. This states that a judgment has meaning only because it can be shown definitively true or false; i.e. it must give an experience that can show this value of truth.

    This version is called strong because of the fact that it excludes that any knowledge be given  that is not empirical and logical and therefore excludes that a sense can be given to any expression that is not the result of empirical knowledge or logical deduction derived from empirical propositions. This version of verificationism will be criticized by some positivists less radical, as Neurath and Carnap, for the simple fact that, if to give sense to a proposition is necessary its verification, even the principle of verifiability itself must be verified, and this It is not possible.

    Numerous propositions of common use, whose meaning seems clear for the terms that we use, are unverifiable as statements that express the past or the future, such as “Churchill sneezed 47 times in 1949” or "Tomorrow it will rain." These propositions can, in principle, be verified, then it can be provided a method for the verification and for the principle of verifiability ‘weak version’ are equipped with meaning, but not for the ‘strong version’; they are only nonsense.

    There are to be rejected the assertions about the Absolute and in general of metaphysical nature, at least as propositions to which it is possible to apply the positive verificationist method, even though this does not exclude its existence: to try to deny a metaphysical proposition has the same meaning as to try to prove it. The metaphysical propositions are therefore omitted, unrebutted.

    Comte rejects the so-called absolute empiricism, which states that any proposition that is not established by the facts is to be rejected as senseless and therefore not liable to be taken as a scientific proposition.

    Special mention must be made of math, no science, for Comte, but language and therefore the basis of any positive science. Mathematics as well as logic, as will say the logical empiricists, has the purpose of showing the connections between propositions in order to maintain the truth value of these, not to produce new values. The propositions of mathematics are ‘a priori’ truth, therefore, as such, can not be verified and therefore they say nothing of the world, but tell us how of the world it must be spoken after having experienced it.

    The critique perhaps best known to the principle of verifiability is provided by Popper. He, though being its main critic, never abandons the beliefs set in the positivist poster and the idea that science has a rational and deductive structure, though describable in ways other than those contemplated by Schlick. In particular the principle of verification, weak and strong version, is abolished and replaced by that of falsifiability. This principle is in fact an admission of the impossibility of science to arrive at statements that they claim to be checked as they are, and also a condemnation of the principle of induction when it claims to provide a basis for the formulation of necessary laws . Popper says that billions of checks are not enough to determine if a given theory is certain; it is enough a falsification to show it is not true. The criterion of controllability of Carnap becomes the possibility of a statement to be subjected to falsification and the structure of science, as already stated by Hume, is that it does not confirm the hypothesis, to the maximum falsifies it. The experiments themselves to which are subject the laws of science are useful when trying to falsify the laws themselves foreseen by them and not if they try to verify them.

    Criticism burying verificationism come from the so-called post-positivist epistemology, whose leading exponents are Kuhn, Lakatos and Feyerabend. In varying degrees all three claim that a fact can not be verified because the bare facts not even exist, but can only be represented in a theory already considered scientific. Therefore, there is no distinction between terms of observation and theoretical terms, and even the same concepts considered basic of science possess the same meaning if designed within two different theories (think for example to the concept of mass for Newton and Einstein) . According to post-positivism also science itself is not empirical because even its data are not empirically verifiable and there is no criterion of significance, that is, it is not possible to separate a scientific statement from one that concerns other human activities.

    Now, finally, we follow the position of Professor Franco Giudice for whom in the work “Controllability and meaning” (1936-1937) Rudolf Carnap recognizes that absolute verification in science is almost impossible. It must, therefore, change the criterion of significance; the principle of verification must be replaced with the concept of confirmation: a proposition is significant if, and only if, it is confirmable. The criterion of verifiability of propositions consists only of confirmations gradually increasing. Thus, the acceptance or rejection of a proposition depends on the conventional decision to consider a  given degree of confirmation of the proposition as sufficient or insufficient. Then, the meaning of a proposition is determined by the conditions of its verification (verification principle): a proposition is significant if, and only if, there is an empirical method for deciding if it is true or false. If such a method is not given, then it is an insignificant pseudo-proposition.

    Marina P. Banchetti

    What you are referring to when saying "There could in fact be multiple statements inherently logical for the explanation / interpretation of a certain phenomenon" is what philosophers of science call 'the underdetermination of theory by data'.  That is, the same phenomenon can be explained by multiple theories, which are often incompatible with each other.  this underdetermination increases when our theories postulate entities or processes that are unobservable.  Thus, given the nature of the scientific method and especially the inherent problem of underdetermination, no philosopher of science (not even the positivists) ever endorsed verificationism. This is because, whether one is dealing with universal laws or statistical laws, the verification of a hypothesis would require that all possible cases covered by that hypothesis be tested and that each of these tests confirm the hypothesis.  But it is impossible to test all possible cases, thus the best we can have is a high degree of confirmation.  One must recall that, for the logical positivists, the only real statements that could be verified were either analytic statements, whose truth could be established a priori via a simple analysis of the relation between subject and predicate, and observation statements, whose truth could be established by comparing the statement with a direct observation. But, scientific laws and hypotheses do not meet either of these criteria because they explain phenomena by reference to theoretical entities (which are unobservable by definition) and because they cover all possible cases of the phenomena in question (which cannot be observed by definition).  In The Philosophical Foundations of Physics, Rudolf Carnap, himself one of the great proponents of logical positivism, argues precisely this point by stating "At no point is it possible to arrive at complete verification of a law.  In fact, we should not speak of 'verification' at all - if by the word we mean definitive establishment of truth - but only of confirmation." 

  • Ritesh Raval added an answer in Blood Brain Barrier:
    How can I assess if a drug can cross the blood brain barrier?

    hi what would be the best methods to assess if a drug has crossed the blood brain barrier and to what extent? thanks. 

    Ritesh Raval

    hi thanks a lot for the answers. this is a new topic for me, so appreciate the help

  • David Nnaji asked a question in Emotional Intelligence:
    To what extent is emotional intelligence related to self-efficacy, and what significant effect does it have on learners' achievement?

    Emotional intelligence as a tool for supporting IQ.

  • Paulo Auricchio added an answer in Descriptive:
    If a species is described from a whole specimen that is split into two or more museum lots, is the holotype both of the lots, or just one?

    Here's a question for the ICZN buffs out there:

    If a species is described from a whole specimen that is split into separate museum lots, is the holotype both of the lots, or just one?

    For example: I describe a novel species of snail from a specimen, and the description includes a description of the shell, the soft parts, and the radular anatomy. When depositing the specimen, I separate the shell and it gets a dry catalogue number. I separate the radula as well and it gets a separate catalogue number. The soft tissues get their own number and go into the wet collection. Are all of these lots still the holotype? Are they syntypes? They are all parts of the same organism but are obviously separate museum objects if they are prepared this way. 



    Paulo Auricchio

    Unfortunately, some museum numbering systems do not preview a situation like this. In my opinion, the same number shoud be given to all parts, as I use to do with mammals, for example: dry round skin prapared, body with organs (without skin), or skeleton, all receive the same number. Although it may seem weird to some (because one of these collections makes a non sequencial numbering), this method insures no confusion among other million specimens. All parts MUST be consider as one only specimen. 

    Paulo Auricchio

  • Manuel Herrera added an answer in Data Mining:
    Is there any research paper showing comparative study of all the data mining tools?

    (Preferably Weka, R, Orange, Tanagra tools)

    Manuel Herrera

    Hi Vaishali,

    as Peter pointed above, the ability or performance of any ML model depends on the specific problem you are working.

    FYI, I include a link with one of my works in which six different ML based predictive models are compared for forecasting hourly water demand.


    • Source
      [Show abstract] [Hide abstract]
      ABSTRACT: One of the goals of efficient water supply management is the regular supply of clean water at the pressure required by consumers. In this context, predicting water consumption in urban areas is of key importance for water supply management. This prediction is also relevant in processes for reviewing prices; as well as for operational management of a water network. In this paper, we describe and compare a series of predictive models for forecasting water demand. The models are obtained using time series data from water consumption in an urban area of a city in south-eastern Spain. This includes highly non-linear time series data, which has conditioned the type of models we have included in our study. Namely, we have considered artificial neural networks, projection pursuit regression, multivariate adaptive regression splines, random forests and support vector regression. Apart from these models, we also propose a simple model based on the weighted demand profile resulting from our exploratory analysis of the data.In our comparative study, all predictive models were evaluated using an experimental methodology for hourly time series data that detailed water demand in a hydraulic sector of a water supply network in a city in south-eastern Spain. The accuracy of the obtained results, together with the medium size of the demand area, suggests that this was a suitable environment for making adequate management decisions.
      Journal of Hydrology 06/2010; 387(1-2-387):141-150. DOI:10.1016/j.jhydrol.2010.04.005
  • Laura Fuentes added an answer in Indigenous Studies:
    Any suggestions on studies about aboriginal resilience?

    I would like to know if exist any study trying to explain the resilient process inside to the first nation. For be more exact in front of climate change and role perspective.

    Laura Fuentes

    thank you so much..I found also one relative to your Claire Smith,  "called Culturaral Roots of Well-Being and resilience in Child Mental Health"  I would like with adults but it was Usefull too, beause show me the conextion between culture and resilience....the investigators  contextualize the study in aboriginal communities  from Canada....I will rivew yours thank you....;)

  • Haris Kriještorac asked a question in Social Psychology:
    Is there any (social) psychology literature that suggests what activities we perform for intrinsic vs. extrinsic reasons?

    For example, I would suppose that most people give to charity for extrinsic reasons, whereas they probably go for a run for the intrinsic feeling of it. Is there some social psychology literature that perhaps categorizes these types of activities?

    Additionally, are activities that are perhaps better learned through repetition than others? For example, perhaps it is easy to remember to recycle by being reminded, whereas biting your nails is hard to learn even after someone tells you dozens of times?

  • Fernando Arce Vega asked a question in Breast Ultrasound:
    Does somebody has the link to download The Digital Database for Breast Ultrasound Image (DDBUI)?

    This database is provided by the Harbin Institute of Technology and the Second Affiliated Hospital of Harbin Medical University.

  • Shyam Lakshmanan asked a question in pH:
    In adsorption studies for removing an anionic substance using AC. pHzpc of AC was 8-8.9. Why does adsorption drop, then rise at around pH 9?

    Has anyone observed a rise in adsorption of an anionic substance on activated carbons as pH rises?  Can I get some advice as to what could be happening?

  • Jenny Vo added an answer in Physical Chemistry:
    Anyone knows where can I find a free pdf format of the book: "Quantum chemistry" (MCQuarrie)?
    I need 1 book: "Quantum chemistry" - MCQuarrie and solutions problems of this book. Please help me to find free pdf format of this book.
    Jenny Vo

    Hey all,

    The current PDF copy of the book and solutions are the Vivabooks edition. I have obtained a PDF copy of the regular version if anyone needs that specific one. There is no PDF of the solutions manual for this version. 

  • Domenico Voltolina added an answer in pH:
    Is it possible in a water tank to control pH (for example a tank with volume 15 L)?

    pH and role of atmospheric pressure and other parameter!

    Domenico Voltolina

    perhaps an explanation of what you plan to keep or do in the tanks might help? pH control may be achieved  and fine tuning is perfectly possible. just look at all the possibilities in Mohan Thampi's answer

  • Shyam Lakshmanan added an answer in Drinking Water:
    What is the best removal methodology for toxic elements from drinking water ?

    best removal methodology means cost effective, keep water quality, time

    Shyam Lakshmanan

    I would agree with Peter, and also Dhiman.  First you need to know what you wish to remove.  After that you look at possible options.  In the real world, cost is also to be considered.  Then you need to look at cost effective methods.

    Activated carbon, whether surface modified or otherwise finds application, in a wide range of adsorption applications.  However, since it is expensive, then there arises the question of deterioration during regeneration.  Recent work done on microwave and ultrasound regen seems to show ability for repeated re-use of the AC.  However, then we ned to incorporate designs to enable the use of such technologies for regenerating the AC.  

    If the component to be removed is ionic in nature, perhaps specific ion exchange resins could be the adsorbent of choice as it will enable repeated re-use through regeneration.  

  • Drilon Bunjaku asked a question in MATLAB:
    Is there anyone who has already established an interface between Robotis LN-101 (controller CM-700) and Matlab?

    Currently, I am making a research with Robotis controller CM-700, which is connected to PC through a module called LN-101. The controller works perfect with Robotis software called RoboPlus.

    I am wondering if there is possibility to control this controller through Matlab?!

     I would really appreciate your help!

  • Grant Mitman added an answer in Algae Culture:
    Does any have a technical idea on how to control algae population in sand and nutrient solution?

    I am doing sand culture pot experiment in glass house. I control the algae by tear the sand and disturb the nutrient solution. In this method I control the algae population. But I cannot do daily. So, anyone can give me the permanent solution to control the alga population in sand culture pot experiment and refer me good article.

    Grant Mitman

    copper sulfate in low conc or http://www.amazon.com/Pondcare-Algaefix-Algae-Control-1-Gallon/dp/B000HCMN8I/ref=sr_1_1?ie=UTF8&qid=1444775943&sr=8-1&keywords=algae+kill

  • Marcelo Preite added an answer in Column Chromatography:
    If synthesis of 8-Methyl-2′-deoxycarbaguanosine from 2′-deoxycarbaguanosine, during this reaction the sugar cleaved, please help me ?

    To a solution of 4 (0.5 g, 1.5 mmol) and FeSO4‚7H2O (3.4 g, 12 mmol) in 80 mL of 1 N H2SO4 was added an aqueous solution (50 mL) containing 1.3 mL of 70% tert-butyl hydroperoxide (9.5 mmol) dropwise over a period of 5 min. After being stirred at 0 °C for 60 min, the reaction mixture was neutralized with saturated KOH solution. The supernatant obtained by centrifugation resulting in a brownish solid was triturated three times with 100 mL of methanol. The combined methanol solution was concentrated, and the residue was subjected to silica gel column chromatography. Elution with CH2Cl2/methanol (9:1) afforded 8-meth- yl-N-isobutyryl-2′-deoxycarbaguanosine (5) as a white powder, yield

    Marcelo Preite

    Is this the original reference, Thana?:

    DOI: 10.1021/ja036233i

  • Jenny Vo asked a question in Bioanalyzer:
    Weird Bioanalyzer results?

    Hey all, I've been having issues with my bioanalyzer results, where the electrophoresis doesn't run all the way through the length of the "gel", and the bands are all squished down at the bottom. 

    I know it is not the priming station or the machine because someone else used them successfully just an hour before. The Agilent DNA kit was also new and not expired, and the gel-dye mix was made just 5 days ago. 

    I am wondering if any one has seen results like this? 

  • Justin Camara asked a question in Transporter:
    Can anyone provide an overview of techniques for measuring the subcellular localization of a transporter protein similar to GLUT4 (pm vs vesicle)?

    I can find innumerable articles discussing techniques for subcellular localization of transmembrane proteins, but I don't have the experience to determine the pros and cons of various techniques that are currently available to researchers. I need help selecting the best techniques for subcellular localization a transporter similar to the GLUT family of transporters. I'm mainly interested in differentiating between plasma membrane levels and vesicular levels.

  • Chithan C Kandaswami added an answer in Carcinogenesis:
    Is there any evidence about the carcinogenesis of artificial sweeteners?

    Is there any evidence about the carcinogenesis  effect of artificial sweeteners used by diabetes mellitus patients? 

    Chithan C Kandaswami

    Thank you, Dr Graymer.


  • Meri Diana Strauss Foesch asked a question in Roots:
    Can anyone suggest a non destructive method to primary roots measurement?

    I'm trying to evaluate the effects of the roots on stabilization of slope.