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  • Luis Carlos Ramos added an answer in Plant Hormones:
    How is it done the ABA germination biotest with lettuce seeds?

    I keep reading reports that seeds of lettuce (var. Grand Rapids, for instance) are used in such a biotest. However, I don't find the precise amount (uM/L) used. Conditions are usually dark ~25 to 28°C for 48 hours. Are you aware of a specific concentration for effective germination inhibition in uM/L?

    My purpose is actually to test if my ABA is still good...

    Luis Carlos Ramos · Instituto Agronômico de Campinas

    thanks, Muayed. Do oyou have a reference on how is this test done? What levels of ABA?

  • Pardis Td added an answer in Aversive Therapy:
    Do you believe obligation can be benevolent or is the perception of obligation always aversive?
    Kant described benevolence in obligation. Are there any situations in which people might regard being in a situation of obligation to others as benevolent?
  • Teodoro S Kaufman added an answer in Nalidixic Acid:
    How can I determine if nalidixic acid is pure?

    I received (Nalidixic Acid) as a gift sample , when I used it it alwayes give tailing & the other product synth from it give the same tailing! 

    its suspecious as in TLC I measured its MP= 204 not (229-230 as reported)

    Teodoro S Kaufman · Instituto de Química Rosario

    Run NMR. Other alternatives are DSC, IR, etc.

  • About the Loschmidt's paradox: what breaks the time reversibility of the classical mechanics ?

    The Loschmidt's paradox poses the following problem:

    As the laws of the classical mechanics are time-reversible, then a gas left free in a in a container with perfectly reflecting walls, and initially in a thermodynamic state of non-equilibrium, should at some time return to the non-equilibrium state. But the 2nd law of the thermodynamics denies such an evolution.

    As the walls of the container are perfectly reflecting, Loschmidt considered that at some time the velocities of all the molecules in the gas would be reversed, s.t. the gas should return to the initial state. So, in the evolution of the gas there should be an interval of time during which the entropy increases, e.g. from t0 to t1, followed by an interval during which the entropy should decrease, see the simulation in Internet http://mw.concord.org/modeler/showcase/thermodynamics/loschmidt.html .

    However, such an evolution is though in conflict with the 2nd law of the thermodynamics.

    My question: what exactly breaks the time symmetry of the laws of the mechanics? What is the effect that disobeys this symmetry?

    AN EXAMPLE: assume for simplicity that the container has two identical chambers, A and B, of square transversal section and separated by a wall. Initially the gas is confined to the chamber A, and at a time t_0 the wall is pulled out.

    (I have a certain image about this issue, but I want to see other opinions.)

    Clifford Chafin · North Carolina State University

    Arturo, is this for a discretized diffusion model?  I have never known how far to take these in relation to classical gases.  Can you post some links?  

  • Does anyone happen to know why frequency domain echo grating AI-s are not used for gravitational acceleration measurements?

    There are AIs using time-domain echo grating for g measurements, so I was wondering if anyone happens to know if there is any information on frequency domain echo grating AIs on g measurements. Is it even possible?Any published articles would be helpful.

    Heleri Ramler · University of Aberdeen

    I was wondering if you could clarify another thing for me? How come in the time-domain experiments the measurements do not rely on the phase of the scattered electric field (page 162 of http://www.sciencedirect.com/science/article/pii/B9780123855084000036)? I thought the scattered electric field carries the phase of the grating? Or is there some other meaning behind it? Because in gravity measurements it is again necessary to account for the vibrations.

    Thank you!


  • Kenan Mahmutovic asked a question in Marketing:
    Which metrics to use to measure marketing effectiveness and marketing efficiency?

    Which metrics should we use to measure marketing effectiveness and marketing efficiency?

    Do you agree that marketing performance = marketing effectiveness + marketing efficiency + adaptability ?

    Please list those metrics that you usually use in your MPMS. (marketing performance management system).

  • Bhagya Deepachandi added an answer in ELISA:
    Optimized serum dilution for ELISA?

    Is there any standard range or a limit for diluting the serum for ELISA optimizing? If the optimized dilution is about greater than 1:10000 (eg. 1:16000, 1:64000) and still giving a good OD value for positive control, can we take that dilution for assaying samples?


    should we optimize the assay for lower serum dilutions (like 1:500 or 1:1000) by changing (optimizing) the blocking buffer to get minimum non-specific background?

    Bhagya Deepachandi · Faculty of Medicine, University of Colombo, Sri Lanka

    Thanks Adam, I agree with you. I have an another problem. For the optimization I use a confirmed positive sample which was rarely picked within my study cohort. Most of patients having lower (very minimum level compare to that positive) antibody concentration. In that case how should I do sample analysis? should I use lower serum dilutions also?

  • Amali Guruge added an answer in DOCK:
    What are the steps to prepare 3QX3 crystal structure for docking process using Chimera?

    Since 3QX3 contains DNA, I want to know how to do the 'dock prep' process for enzyme? (I want to keep the DNA molecule for docking process)

    Amali Guruge · Institute of Chemistry Ceylon, Sri Lanka

    Thank you Qazi. I am doing the docking process using DOCK6. Before the docking process, we can use 'dock prep' option in Chimera to prepare the receptor for docking. But my problem is how to do that process, when receptor contains DNA?

  • Pradipta Bhakta asked a question in Pain Management:
    Anybody interested in good academic discussion in anaesthesia, intensive care and pain management?

    Please join our "Anaesthesia Interactive Group" in Facebook by clicking this link: https://www.facebook.com/groups/Anaesthesiainteractivegroup/
    Make sure you have a Facebook account and you update your speciality and area of interest in your public profile before clicking the "Join the Group" icon. 

  • GHENIM Asma Fethia asked a question in Cretaceous:
    How to succes the Taphonomic study of my Cretaceous Fossils?

    Hello--- I am writing to you for asking: How to succes the Taphonomic study of my Cretaceous Fossils? Thank you for your time.

  • Has anyone done a literature search on SET (student evaluation of teaching) who can give me some clues on how to narrow the search?

    I'm particularly interested in getting a handle on the broad areas covered by the research in say the last 20 years so I can confirm (or deny) a notion I have that little attention has been paid to the consequential validity of SET

    Michael Marston · Macquarie University

    Hello Pencho,

    Thank you for the link - it's a very rich site.


  • Could we use the global geoid undulation as a complementary information for geophysical exploration such as groundwater finding?

    As is well known the geoid separation is computed from gravity information which is related to the densities of the material on the Earth. now the question is: Could we use the global geoid undulation (e.g., EGM2008) as a complementary information for geophysical exploration such as groundwater finding?

    A. M. Ebraheem · Assiut University

    Dear Dr. Seedahmed

    Thank you very much for this fruitful discussion . I am convinced and totally agree with what you have said. I heard about GRACE but I do not have any experience on that. Kind Regards

  • Uğur Canpolat added an answer in Galectin 3:
    What Cardiac markers are specific for fibrosis particularly in the atria?

    I am trying to understand what biomarkers I can use to predict fibrosis and recurrence of AF in a given patient population.

    Does anyone know if others exist besides ST2, Galectin-3, TGF beta and TNF-alpha?

    Uğur Canpolat · Hacettepe University


    Muscarinic (M2) receptor antagonists





  • Yoann Pageaud asked a question in CGI:
    What is the difference in the creation of a phylogenetic tree with/without the outgroup ?

    HI everyone, 

    I'm trying to build a phylogenic tree for the insulin protein throught various species.

    In order to do this I'm using a website that allow the creation of tree. Here is the link to the page of the website I use : 
    But the arrangement of the phylogenic tree resulting is not the same if I take, or not, the outgroup (take a look at the pictures attached).

    I know the calculus is not the same and that it use Markov Chains but nothing more.

    So can anyone explain to me why the results are different?
    Thank you for your help.

  • Adekunle Oke added an answer in VSM 2013:
    Has anybody recently used the 2013 Values Survey Module (i.e. Hofstede survey)? I have results (300+) from Slovakia I can share if you have.?

    I have recently done the Hofstede Value Survey Module 2013 in some businesses in Slovakia. As Slovakia was not an original country where his survey was done, it is difficult to find reliable data. I'd be willing to share my results with anybody interested if I can get some results from a recent (perhaps yet unpublished) survey. I have about 70 results from the US, but it isn't a big enough sample for me to use. So I'm looking for anybody else who might be willing to help. Thanks.

    Adekunle Oke · The Robert Gordon University

    Collaborating isn't a bad idea. . .

  • Uğur Canpolat asked a question in Patient Experience:
    Any prognostic value of seasonal variation in requirement for antihypertensive medication?

    Why some patients experience seasonal variation in blood pressure values?

    Any data about prognostic importance of this finding?

  • Uğur Canpolat asked a question in Pathophysiology:
    Any association between ventricular rate and atrial thrombus in AF?

    Any study investigating the mean ventricular rate and atrial thrombus formation?

    Any pathophysiological relationship?

  • Heart rate is a fact or myth for hypertensives?

    Reduction in heart rate using anti-hypertensive drugs should be or should not be a therapeutic target among hypertensives free of overt cardiovascular disease?

    Use of beta-blockers or CCB for hypertensives to reduce heart rate or none of them?

    Is there a must or should for physicians to reduce heart rate below a known level in hypertension?

  • Christopher Daniel Duntsch added an answer in EDTA:
    What is exact role of Trypsin and EDTA in dislodging the plated cells ?

    role of Trypsin and EDTA in dislodging the plated cells

    Christopher Daniel Duntsch · Hybrid Bioscience, Inc., Synthetic Investments, Inc., The University of Tennessee Health Science Center

    Direct question and answer. And as above, Dr. La Rocca.

    Trypsin is a mixture of proteases derived from porcine pancreas where each target specific peptide sequences and cleave them, thereby breaking inter and intracellular bonds and primary attachment, fixation biology at the protein and peptide level. Due to its digestive strength, it is widely used for cell dissociation, during routine cell culture passaging and primary tissue dissociation. EDTA is a Ca+2 chelator, with several biologic roles in chelating free and bound Ca+2 in the fluid composite, tissue culture biology, in vivo tissue digestions, increasing Tryspin activity and protein peptide access in real time.

  • Alejandro Rivero added an answer in MS/MS:
    Is it obvious that the physical masses and coupling constants are independent of the renormalization scheme? How can you prove it?

    The most trivial example being that MS and MS bar appear to give different answers for these in, say, \phi^3 theory in 6 dimensions.

    Alejandro Rivero · University of Zaragoza

    By Physical do you mean the pole masses, or some running scheme?

    For reference, I did recently a similar question here in this link

  • How can I estimate paleotemperatures based on oxygen isotopes of dolomite cement? Could someone point me to a good reference?

    How can I estimate paleotemperatures based on oxygen isotopes of dolomite cement? Could someone point me to a good reference?

  • How to get a perfect intervertebral disc from this image?

    my code is

    sd=stdfilter(I, [3 3]);
    result=m1 & m3;

    res = result;

    [L,n] = bwlabel(result,8);



    for i=1:maxi






    i didnt get a perfect intervertebral disc

    Christopher Daniel Duntsch · Hybrid Bioscience, Inc., Synthetic Investments, Inc., The University of Tennessee Health Science Center


    Your question and code reference to a T2 weighted sagital lumbar MRI, that includes T10 - S1 and lower elements, requires some comments and clarifications.

    You refer to a perfect intervertebral disc, from an image with 7 - 8 IV discs shown. Are you using IVD generically, or looking at a T10 vs L1 vs L3 vs L5 disc for example. I gave those disc levels intentional because they are all very different and unique from each other, per normal spinal disc biology and medicine in humans, per anatomy, size, etc.

    As above, L5S1 is moderately degenerated. So let's stay from that one.

    The rest of discs look relatively normal, healthy.

    Finally, in the real world there are no perfect discs. Instead there are healthy normal disc defined by imaging, osmotics and water content vs disc pressure, biomechanics, size in every dimension and direction, normal gross and histologic anatomy and biology AND by the patients themselves, clinically.

    Attached is a good article that attempts to define normal and degenerating discs in space, and time, and biology, and imaging. Other refs as well. Given the code above, should be of interest.

    Christopher Duntsch, MD, PhD

    1: Colombier P, Clouet J, Hamel O, Lescaudron L, Guicheux J. The lumbar
    intervertebral disc: from embryonic development to degeneration. Joint Bone
    Spine. 2014 Mar;81(2):125-9. doi: 10.1016/j.jbspin.2013.07.012. Epub 2013 Aug 7.
    Review. PubMed PMID: 23932724.

    2: Pattappa G, Li Z, Peroglio M, Wismer N, Alini M, Grad S. Diversity of
    intervertebral disc cells: phenotype and function. J Anat. 2012
    Dec;221(6):480-96. doi: 10.1111/j.1469-7580.2012.01521.x. Epub 2012 Jun 11.
    Review. PubMed PMID: 22686699; PubMed Central PMCID: PMC3512276.

    3: Chan WC, Sze KL, Samartzis D, Leung VY, Chan D. Structure and biology of the
    intervertebral disk in health and disease. Orthop Clin North Am. 2011
    Oct;42(4):447-64, vii. doi: 10.1016/j.ocl.2011.07.012. Review. PubMed PMID:

  • David C. Rine added an answer in Natural Numbers:
    Is it logical to say: “real number set has more elements than natural number set”, so “real number set is more infinite than natural number set”?

    Why we say mathematically something is more or less, bigger or smaller … than the other (different grade)? One of the main scientific reasons is because of different quantities (not being bijective).

    So, just by different quantities, it is logical to say mathematically “real number set is bigger than natural number set”; “real number set is more infinite than natural number set” ….

    David C. Rine · George Mason University


    Very interesting idea. Has this affected you in the past? How would like like to propose some changes? I am looking back to find would for what RG stands. Help. 

    Following up a bit more. Are you all (above) suggesting that in, for examples, areas such as the Life Sciences there is a philosophy of science(s) underlying the more dominant culture such that if this philosophy of science(s) is not adhered to there is an underlying bias towards work of those on the 'outside'?

    Replace Life Sciences with Physical Sciences. Is the same idea, philosophy of science(s), prevalent?

     Would any of you from the above mentioned dialog wish to share examples that illustrate these biases? That might be interesting and it might help to improve peer review processes.

    Best wishes.

  • Ronald Fricke added an answer in Fish Taxonomy:
    Can a fish person (marine biologist) identify this fish?

    from karachi

    Ronald Fricke · State Museum of Natural History Stuttgart

    No, it cannot count as a Lessepsian species; to qualify as a Lessepsian species, it needs a) to occur in the Red Sea, and b) to immigrate through the Suez Canal into the Mediterranean. Neither is the case with this species. It is restricted to the Western Indian Ocean as far as we know.

  • Louis Brassard added an answer in Cognitive Systems:
    Is Chalmers' so-called "hard problem" in consciousness real?

    In his 2014 book "Consciousness and the Brain: Deciphering How the Brain Codes Our Thoughts" Stanislas Dehaene wrote "Chalmers, a philosopher of the University of Arizona, is famous for introducing a distinction between the easy and the hard problems. The easy problem of consciousness, he argues, consists in explaining the many functions of the brain: how do we recognize a face, a word, or a landscape? How do we extract information form the senses and use it to guide our behavior? How do we generate sentences to describe what we feel?

    “Although all these questions are associated with consciousness,” Chalmers argues, “they all concern the objective mechanisms of the cognitive system, and consequently, we have every reason to expect that continued work in cognitive psychology and neuroscience will answer them. By contrast the hard problem is the “question of how physical processes in the brain give rise to subjective experience … the way things feel for the subject. When we see for example, we experience visual sensations, such as that of vivid blue. Or think of the ineffable sound of a distant oboe, the agony of an intense pain, the sparkle of happiness or the meditative quality of a moment lost in thought … It is these phenomena that poses the real mystery of the mind”."

    Stanislas Dehaene's opinion is "that Chalmers swapped the labels: it is the “easy” problem that is hard, while the “hard” problem just seems hard because it engages ill-defined intuitions. Once our intuition is educated by cognitive neuroscience and computer simulations, Chalmers’ “hard problem” will evaporate".

    Personally, I agree with Stanislas Dehaene's opinion.

    According to Plato, Socrates often said  the Delphic maxim: ''Know thyself''.  This thyself is our Mind,  The human mind is so far  incapable  of comprehending itself.

  • Aakanksha Sinha asked a question in Urban Planning:
    Is anyone currently working on food deserts?

    I am increasingly finding the issue of food deserts very interesting. Particularly in context of urban planning and decision-making by grocery stores and the driving factors. Is anyone currently working on this, or is interested in working on something together in this area? 

  • Rosie Morland added an answer in Pdf:
    Are there other alternatives to WebPlotDigitizer?

    I use WebPlotDigitizer (http://arohatgi.info/WebPlotDigitizer/) to extract data from plots in publications (typically pdf files ). What else do people use?

    Rosie Morland · Imperial College London

    It's probably in Ricardo's list, but I use the built in measuring tools in Adobe Acrobat - can send you a protocol if you'd like! V.easy and you can save the measurements on the pdf for later reference

  • Could anyone suggest me lipases for triacylglycerol synthesis?

    I am looking for commercial lipases to synthesize triacylglycerols using glycerol and EPA/DHA-ethyl esters as substrates. Could you give me any suggestions according to your expertise? Thank you so much.

    Miguel Ángel Rincón Cervera · University of Chile

    Thanks, Israel. I will try that lipase and I hope it is ok. Best regards!

  • José Eduardo Jorge added an answer in SPSS:
    Anyone who knows how to replace missing values in spss, kindly help

    like in stata how one may replace for missin values ussually given by a (.) into something like 0

    José Eduardo Jorge · National University of La Plata

    To explore the subject more deeply , I recommend you to study the methods for "imputation of missing values" in Tabachnick & Fidell: Using Multivariate Statistics. If you can, see the little book Allison, Paul: Missing Data (Sage). I linked to a brief exposition of the latter. 

  • How do you optimize HRT of anaerobic digester fed with kitchen waste?

    I am working on bi phasic semi continuous fed batch biogas reactor system. kitchen waste , the raw material, is fed daily to the system assuming HRT of the system to be 20 days. When  the reactor could not be fed on some day its biogas production is affected. In this condition how would the HRT of the reactor be affected? 

    Sebastian Borowski · Lodz University of Technology

    HRT of 20 days means that within 20 days the whole reactor volume is likely to be replaced. Hence, if you for instance have a reactor with an active volume of 1 liter, you should provide  a daily discharge of 50 ml of digestate and feeding the digester with the same volume of feedstock. If you feed the digester, let's say, five days a week (only in working days) then the calculated HRT is 28 days. In this case, to achieve a HRT of 20 days (or rather to be precise 21 days), you should fee the reactor with approx 67 ml every working day.