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  • Marc Tessera 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.

    So Louis, according to you, all the scientific questions are indeed questions within an ideology. I wonder which question is not! 

    The problem with this philosophical approach is that everything is in everything and the confusion is total. Belief is a synonym of ideology which is itself a synonym of science which a synonym of religion … and so on.

    I wonder how it is possible to keep a clear mind in such a mess.

  • What splits us up?

    What renders common communication so difficult at times? What makes solidified human relations scarce and unusual sometimes?

    António Manuel Abreu Freire Diogo · University of Coimbra

    An unusual answer, Dear Marwan:

    a) Nothing, if we use our brains;

    1) Bad humour; and

    2) The egos.

  • Is Loretnz symmetry conserved for all velocity ranges?

    I want to know whether Lorentz symmetry is conserved for all the velocity ranges or not?

    Is the Lorentz invariance completely related to Lorentz symmetry; i.e. if Lorentz symmetry conserved then Lorentz invariance is also conserved or there are certain conditions where the Lorentz invariance conserved while Lorentz symmetry is not? what are they if there are such conditions.

    To Johan

    The Lorentz formulas come from a well specified set of assumptions.

    You mix coordinates (what are they .), information, Doppler effect, inertial frames, waves, a cartesian metric, which have no clear definition. With this kind of narrative, that is too common in Physics, you can prove anything.

  • Nitesh Sule added an answer in Tyrosinase:
    Can anyone suggest an easy spectrometric assay using L-dopa for tyrosinase activity?

    tyrosinase activity determination using l dopa as substrate

    Nitesh Sule · Texas A&M University

    Tyrosinase converts L-Dopa to dopaquinone, which then forms dopachrome. You can measure the formation of dopachrome using a UV/Vis spectrophotometer at 475 nm (extinction coefficient of dopachrome at 475 nm is 3700 M-1cm-1).  

    This assay is usually monitored for less than 90 s, since the dopachrome eventually forms melanin. Alternatively, you can monitor the reaction for longer times by using a "coupled assay" in which ascorbic acid is added. Dopaquinone (produced by tyrosinase from L-Dopa) causes oxidation of ascorbinc acid, and this can be monitored as reduction in absorbance at 265 nm, for up to 2 min.

    Good luck!

  • Steingrimur Stefansson added an answer in Collagen:
    Trouble with BMEC (brain microvascular endothelial cell) culture.

    I have recently failed many attempts at culturing BMEC and I don't quite understand why.

    Even though I was able to plate endothelial cells before, now they won't attach to the plate anymore. I initially thought the collagen was causing the problem since collagen coating is essential for endothelial cell culture. However, after discussing with Sigma aldrich, the source of my collagen, I am not sure anymore. It seems that I was storing collagen correctly and have been following the exact protocol of collagen coating given by Sigma.

    Can somebody help me what I am doing wrong?

    I am using the protocol from this paper with slight modification.

    Demeuse, P. et al. Compartmentalized coculture of rat brain endothelial cells and astrocytes: a syngenic model to study the blood-brain barrier. J. Neruosci. Methods 121, 21-31 (2002)

    modification - since our lab doesn't have ultracentrifuge, rather than continuous percoll gradient centrifugation, I used 1.07g/ml percoll and 1.03g/ml percoll solution to purify endothelial cells. [Since endothelial cell density is around 1.06g/ml]

    Steingrimur Stefansson · HeMemics Biotechnologies Inc

    4 weeks is a long time. How were your reagents stored? If they were not frozen, then they might have bacterial or fungal contaminations. 

    Without trying to figure out what going wrong, just make up fresh reagents. If they work, then there is something happening when you store the reagents. If that's the case, then don't store the reagents.

  • James D. Korp added an answer in X-Ray:
    Which is the best (and user friendly) Single-crystal X-ray diffractometer on the market now?

    We are a research group in an academic institution and looking into buying a diffractometer for single-crystal X-ray studies of small molecules. We want an instrument combining excellent capabilities with a user-friendly interface and great customer support. Any suggestions on this? Thanks! 

    James D. Korp · University of Houston

    Yes, you can certainly narrow the scans from the usual 2 to 5 degrees in omega.   However, if you want to minimize peak overlap from competing twin domains you need to use an arc similar to that used on CCD machines, namely 0.3 to 0.5 degrees, and that means you need to collect about 5-10 times more images on the IP XRD.   Since each image has a large amount of overhead time associated with it (to drop the plate, read the plate, erase the plate, and raise the plate), this would make data collection take far longer than on a conventional CCD machine.   That's why I say IP is the worst possible choice for analyzing twins.   It takes far longer to get the same degree of accuracy.   By the way, earlier this year I discovered several major errors in Rigaku CrystalClear software, mainly with the XPLAIN routines.   The company tells me that they revised the software to fix these, and I assume they have put the latest changes on their web site.  If you haven't upgraded your Rigaku software in the past 6 months, you need to do so.

  • Leonardo Cannizzaro added an answer in Tuna:
    Has anyone worked on Fish Aggregating Devices (FADs) and can you write your experience ?

    In India we have deployed Fish Aggregating Devices at Andaman & Nicobar Islands and Lakshadweep group of Islands for the benefit of Fishermen community as requested by the respective Fisheries Administration. According to the Lakshadweep fishermen the Tuna aggregation is nearer FADs and they are getting a good catch. Please share your experience. I can provide more details whenever required. Thank you.  

    Leonardo Cannizzaro · National Research Council


  • What about the low dose response for EBT3 film?

    Most of time, we used five or several point dose vs OD values to produce the fitting equation, then we use this equation to translate the optical density to dose.

    Question : For the calibration film,

    Supposing we chose five dose levels (50cGy,100cGy,150cGy,200cGy,300cGy) and background film, the lowest dose level was around 50cGy. If we wanted to perform low dose measurements for TOMO MVCT dosimetry, because of  low dose, the measurements were repeated several times. This method was used to improve the signal to noise ratio of 30cGy doses. Does it overestimate or underestimate the low dose for EBT3 film ?

    Constantin Daniel Negut · Horia Hulubei National Institute of Physics and Nuclear Engineering

    Wouter Crijns,

    thank you for the paper. sorry, I didn't read it yet, but I'll do it soon.

    my example wasn't for a ebt3 film dosimetry system (actually, figures are from a ECB, but it doesn't matter). the ideea is one does not perform measurement measurement outside de calibration curve.

    and a 0 Gy signal will not solve the problem, as it is affected by high uncertainties.

  • What is the difference between X-Ray Diffraction (XRD) single crystal X-ray crystallography?

    I need your precious comments.

    Peter Kimpende Mangwala · University of Kinshasa

    A crystal is a solid in which a basic pattern, called unit cell, is repeated regularly in the three space directions. A crystal in which all the unit cells are oriented in the same way is called single crystal. In the single crystal X-ray crystallography, diffraction measurements are perfomed using single crystals to determine the crystal structure. If single crystals are of too small dimensions to be analyzed individually, we talk about powder. For diffraction study, an amount of powder is needed. In the powder lattices are randomly oriented, and one speaks, in this case, of the Powder X-ray diffraction (PXRD).

    In both cases X-rays are absorbed and scattered by the crystal. As the crystals spread the X-rays only in certain preferred directions, the phenomenon is called X-ray diffraction (XRD) instead of X-ray diffusion.

    In sum, XRD is general, while single crystal X-ray crystallography only involves single crystals.

  • Ulrich G. Hofmann added an answer in Algorithms:
    Is there someone who is extracting overlapping spike in his/her multiunit recordings?


    Is there someone who is extracting overlapping spike in his/her multiunit recordings?

    I would like to understand the algorithm behind it and also I would like to compare the algorithm I use.

    Ulrich G. Hofmann · Universitätsklinikum Freiburg

    Aaah, so, you do not need to separate by time signals, but can use geometry! We use(d) silicon probes with up to 40µm c/c site distance and where able to see one unit on two or three sites (see fig for a 8channel Si probe).... We call that: Searching the footprint.

    Check out the work of Tim Blanche (Blanche, T. J., M. A. Spacek, J. F. Hetke and N. V. Swindale (2005). "Polytrodes: High-density silicon electrode arrays for large-scale multiunit recording." J. Neurophysiol. 93: 2987-3000.) or with more mathematical sophistication the work of Karim Oweiss on Wavelet Package usage: 

    Oweiss, K. G. and D. J. Anderson (2002). "Spike sorting: a novel shift and amplitude invariant technique." Neurocomputing 44-46: 1133-1139.
    Eleryan, A., M. Vaidya, J. Southerland, I. S. Badreldin, K. Balasubramanian, A. H. Fagg, N. Hatsopoulos and K. Oweiss (2014). "Tracking single units in chronic, large scale, neural recordings for brain machine interface applications." Front Neuroeng 7: 23.

    I hope that helps a little


  • How many samples should be used for mergers and acquisition of UK oil and gas companies?

    my research topic is: The impact of mergers and acquisition of UK quoted exploration and production oil and gas companies on shareholder profitability

  • Marzieh Aghababaie asked a question in Biodiesel:
    Can i just inject the biodiesel sample to GC. i mean what will happen for the unreacted TG, DG and MG ?

    i want to determine the FAME produced from oil. i have read about it but it has mentioned that upper phase and heptane will inject to the GC. what if it contains the oil? will it harm the GC coulmn?

  • Merilee Karr added an answer in History of Medicine:
    Does anyone have good resources on the power of storytelling in medicine?

    Has anyone worked in the development of created patient education material and given it to patients and received feedback? Thanks! Embarking on a new project. siguides.com 

    Merilee Karr · Oregon Health and Science University

    This is a busy field. Look up Rita Charon at Columbia, and Narrative Medicine. Bellevue Literary Review should be a gold mine, too.

  • Do you think whether it is proper to connect gravity exclusively with the speed of light?

    Since the beginning of the twentieth century the speed of light is thought to be fundamental to gravitation and its transmission effectiveness. Mathematical physics seeks whether this idea is sufficient for explanation of all phenomena related to mass attraction. Is a change of position needed? What is your opinion?

    Manuel Morales · Institute of Prephysical Research

    Arno, why do you insist that "humble" opinions have value when it comes to nature? Please conduct an experiment, any experiment, without first making a selection. Then, and only then, can you or anyone else say that opinions have merit.

    I have given you the means to prove that you know what you are talking about yet you have failed to do so time and time again. Stop trying to think of nature as being effectual. The unambiguous empirical evidence has shown that nature is causal. Get over it and learn what nature has been telling us all along.

  • Ho are interested to participate at the workshop entitled :Management and Genetic Improvement of Animal Resources, Social –participative Approach ?

    Please find a provisor leaflet

  • Barrie Gilbert added an answer in Physics Education:
    How to make 1st year electrical engineering student understand voltage, current, resistor?

    How to make 1st year engineering student understand voltage, current, resistor?

    Barrie Gilbert · Analog Devices, Inc.


    Yes, I withdraw my assertion that the question "Which comes first, the Voltage or the Current" (which was described in another post as a "Chicken or Egg" problem) is a purely philosophical one. What "came first" were ELECTRONS -- in abundance, which created E-Fields throughout the universe; and much, much later, allowed Volta to show Napoleon his "battery" and as a consequence to be given high office.... and then came wireless. And here we are. 

    By the way, while it is convenient to throw "current sources" and "voltage sources" into a circuit simulation, neither exist "within the IC". The voltages are applied from an external source (a store of electrons) and the currents (a flow of electrons) are generated in the IC by these applied voltages - with a few rare exceptions (such as the harvesting of weak RF fields to operate, say, a medical transducer, and other deviations from the principal theme). 

    In short (no pun intended) a current can only flow when persuaded to do so by a previous-arranged storehouse of electrons. They are an inseparable pair, just as wireless waves are inseparably both voltages and currents - the former generating E-fields and the latter generating H-fields.

    Returning directly to the originally-posted question, there is - perhaps - a case to be made for beginning to teach "electricity and magnetism" by first teaching about EM waves - maybe with the help of a few cheap radio receivers being handed out to the students.

    But the most important skill of a teacher is to transmit a massive sense of enthusiasm for the subject matter. You could read from a dictionary and still gain the attention and admiration of your students provided you do it with enthusiasm coming from the heart and your own vivid excitement about the topic.

    Some years ago, in Japan, I was asked by my host to speak to a body of Electrical Engineering students at Tokyo University. "Hmm.. What shall I talk about?", I asked. "It doesn't matter. You could just read a dictionary and they will lap it up".


  • Kyle H Ramsey added an answer in Primer:
    Does anyone have tips and techniques for the development of PCR Primers for highly conserved regions with Single Nucleotide Polymorphism variation?

    I'm looking for optimised methods and techniques for dealing with areas of low variation. 

    Kyle H Ramsey · Midwestern University

    We have used the TaqMan SNP Genotyping Assays (Applied Biosystems/Life Technologies, Grand Island, NY, USA). Primers are designed using the Custom TaqMan Assay Design Tool (https://www.lifetechnologies.com/order/custom-genomic-products/tools/genotyping/). PUblication pending revsions and second review. 

  • Parviz Parvin added an answer in AES:
    How can we calculate the small-signal gain of a laser amplifier?

    there is a formula in koechner that go=Ep/ηl

    Ep= pumping energy

    l=cavity length

    η = ηtηaηSηQηBηStηASE/AES

    but in this formula there isn't any coefficient for dopant density Nd:YAG.

    Parviz Parvin · Amirkabir University of Technology

    I have measured the small-signal gain and saturation intensities of various gain media over two recent decades!

    In fact, g0 = Delta N * Sigma and Is can be measured through input/output intensities of amplifier, amplification relation and best fitting based on least square method (LSM). However, changing pressure of gaseous amplifier or dopant  concentration of  solid-state and fiber lasers can alter the small signal gain of amplifying media.

    Theoretically, the  concentration indirectly affect on Delta N.

    Please visit our recent papers available  in RG:

    For instance,

    Article: Sajjad Mohammadian, Parviz Parvin, Maryam Ilchi-Ghazaani, Reza Poozesh, Kamran Hejaz  "Measurement of gain and saturation parameters of a single-mode Yb:silica fiber amplifier ", Optical Fiber Technology 10/2013.

  • Sigurður Smárason added an answer in LC-MS:
    I am not getting Precursor/Product ion of Diacylgymnemic acid using LC-ESI-MS/MS after so many trials. Any suggestions?

    Whatever precursor/product ions get it will not be repeated the next day. So, I can't finalize the method.

    Sigurður Smárason · Europaeische Akademie Bozen - Accademia Europea Bolzano

    Your mass of 647 (NL of 36) is not consitent with DAGA, at least not at first glance, With you experimental data not fitting with the certificate of analysis, which is only stating their results but not showing any of the data, I would ask for the data behind their conclusions. Also since they claim mass information perhaps find out how they are measuring that? 

    As this is the only analyte you are having trouble with, to me this points to the company you are buying it from. Is there any chance to get even a small amount from someone else?  

    If that is not a posibility I would strongly suggest derivatization as the next thing to try.

  • George E. Varelis added an answer in Shear Walls:
    How can I create a shear wall with reinforcement in ABAQUS?

    I am trying to create a shear wall section with reinforcement in Abaqus. Anyone know how to do please help? The detailed drawing is attached in this message

    George E. Varelis · University of Thessaly


    Check the layered shell elements option from the Theory/User manual. You can define reinforcement layers (area and spacing of reinforcement) at both sides of the shell element at a specific offset from the central plane. It works well for simple geometries and it is less computationally expensive than a a full 3-D approach.. 



  • Sajjeev Jagannathan added an answer in Myeloma:
    Luciferase tagged human myeloma cell line?


    We are looking to inject the mice with luciferase tagged myeloma cell lines so I was wondering if anyone would be interested in sharing their cells with us. I can send you our fedex information for shipping.


    Sajjeev Jagannathan · University of Cincinnati

    Thank you Sandeep, Do you happen to have any lentiviral plasmids or virus with gfp that you could share?

  • Is possible to "measure" social or institutional innovations, or technology transfer procesess developed for small agricultural growers?

    Measuring innovation is cristal clear when a patent, an utility model, a plant variety or a new trade mark is developed by researchers. However, when social or institutional innovations are developed, or technology transfer is done with peasants or small farmers, innovation is very difficult to measure.

    J. D. Etchevers · Colegio de Postgraduados

    Of course it can be measured.  We did it in Sierra Norte de Oaxaca.  The manuals are available. You need to have a base line and then to measure the change.  We measured the increment in family income, in productivity, in several other áreas.  This ideas can be applied to institutions. Academically you can measured the number of person pertaining to the SNI, you can meadured the number of project approved in national and international convocatories, you can account the amount of money entering to the institution by mean of international projects.  In this case your are centering your action in having the human resources qualified to the task of generating new ideas to be transfered to the small farmer and the money to generate these ideas.  Without these two ingredient there is not progress.  The second thing is to take these ideas to the farmers (Norman Borlaugh dix it) an there you can measured the degree of adoption of the new technologies, the increment in family income, the quality of the life (potable water, sanitary services, etc).  It can be done. It has been done. The worst thing that can happens to an institution like yours and mine is to look only to the inside believing that advancement and progress is controlling every movement of the institutional life  and producing rules for almost any action. We are killing the drive and the interest to work in the sustantial subject established in the institutional mision. Only two projects were accepted in the last CONACYT openning. It is a shame. This happens in our institution. In addition,there are people that think that the real  progress is only be creative and some other that believe that transfering technology is the solution. The true is in between. My question is: who is going to generate the  appropriate technology to be transferred if everybody dedicated his effort to transfer information? .  We need to listen to actors and then generate the change.  Any action must bottom up and no the opposite. 

  • Omar S Barnaby added an answer in Protein Isolation:
    Have you made a comparison of membrane protein isolation kits?

    Has anyone compared/contrasted different kits for isolating membrane proteins? Any advice/ideas on which kits have the highest total yield and/or the highest purity yields? Thanks

    Omar S Barnaby · Harvard Medical School

    Thanks for the responses Muralidhar and Pugazendhi. Pugazendhi - do you mind sharing the protocol that worked well for you? Thanks!

  • Thomas Baldwin added an answer in CRISPR/Cas:
    What is the best type of promoter for expression of guide RNAs in the CRISPR CAS system?

    Exploring the use of CRISPR-CAS in filamentous fungi.

    Hypothesis: Promoters that express small transcriptional regulatory RNA would have the highest expression of guide RNAs for CRISPR-CAS,

    Any thoughts or experiences are appreciated? Many Thanks 

    Thomas Baldwin · United States Department of Agriculture

    Thank you Dr. Enguita and Dr. Sprink. I'll use the U6 promoter in the fungus and see if I can get adequate expression.  

  • Antonio Vives Moreno added an answer in Moths:
    Lepidoptera storage: What can I do with thousands of unidentified moths in ethanol?

    I am working with a collection of > 3000 light trap samples collected in Grand Canyon, AZ, USA over the last three years, with up to 1500 more samples coming in each year. They are currently stored in 250 mL plastic Nalgene containers, and are identified mostly to order with the exception of aquatic taxa.

    The time has come to consolidate this bulky sample set. I know it is always better to save specimen, but what about moths in ethanol? Will a specialist ever be willing to look at these? My lab does not have the time to pin these, and they do not pin well after sitting in 95% Etoh for 2+ years anyway. Can anyone honestly advise throwing these specimens away without a sinking feeling in their belly?

    Yes, you can study this material with the genital slide, but it' s a big job.

    Please, in alcohol only the inmature stages of Lepidoptera.

  • Does the field of Alzheimer's research suffer from the 'Airbag problem'?
    Here is the link to a paper that explains what the Airbag problem is. It should encourage you to think about it. Please let me know what is your opinion on the subject.
    Dimitrije Krstic · University of Belgrade

    “Whenever a theory appears to you as the only possible one, take this as a sign that you have neither understood the theory nor the problem which it was intended to solve.” Karl Popper

  • Do you know a free dendrochronology software?

    We have about 100 disks with diameter from 20 cm to 1.2 meter. We want to measure tree ring width for growth analyzes. We dont have access to lintab, so we are searching for a free software that accept importing scanned images of disks. Since we want to publish our results in a scientific journal, we would like to use a scientifically valid one.

    Jesús Julio Camarero · Spanish National Research Council

    Dear Hormoz, Cdendro and Coorecorder may be useful and very cheap tools for your purposes. See: http://www.cybis.se/forfun/dendro/helpcoorecorder7/index.htm

    Otherwise you can try ImageJ (free and easy)

    I would also advise to polish finely your disks, xdate them  and to a 2nd study on growth-climate associations (this could be really interesting if your species have been little explored by dendroecologists). Good luck

  • Raja Sakthivel asked a question in Coloration:
    What is the reason for coloration effect in high temperature grown single crystals ?

    what is the reason for coloration effect in high temperature grown single crystals ?

  • Daniel Ahmed asked a question in Particle Tracking:
    Is there any plugin for particle tracking in image J?

    Image processing, Image J