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  • Andrei I. Fischer added an answer in Chemical Kinetics:
    Is cobaltic acetate or cobalt (III) acetate an easily available chemical?

    I need a few grams of cobaltic acetate also called cobalt (III) acetate (not cobaltous acetate) as a reference material in my research work but no suuplier provides this material in Pakistan. I wonder if it is available in other countries?

    Andrei I. Fischer

    The ‘cobaltic acetate’ can be synthesized by cobaltous acetate ozonation in glacial acetic acid. For that you can use my method (see link below) without of the treatment with nitric acid. The resulting solution needs to be evaporated, and the dark green residue needs to be dried.

  • A. Subba Rao added an answer in Soil Fertility:
    How can we proceed for decision on soil resource-based cropping sequence?

    Development of soil resource inventory of a given area , is considered highly imperative to take decisions on the options about the suitability of different crops in a farming system mode. At the same time, the information on edaphological requirements of different crops , is equally paramount , so that both are super-imposed in such a way, to delineate soil-crop analogues. This will pave the way for better land utilization efficiency. My further querries in this regard are as follows:

    * How should we develop a soil resource inventory ?. Shall we go for master soil pfofile stdies  or follow the grid- based soil sampling  coupled soil profiles to be later used for developing soil fertility variograms?. 

    * How shall we identify the soil fertility constraints of multiple nature from such soil resource inventory?.

    * What methodology , shall we adopt to identify   optimum soil requirement for different crops ?.

    * How should we identify the cropping sequence based on such soil resource inventory?.

    * Whether cropping sequence and land utilization efficiency are inter-related ?.If so , in what way?.

    I request my esteemed colleagues to share their experiences on these issues. Regards

    A. Subba Rao

    Dr.Daka,generating and collating information at soil series level and use it in crop planning and input use is  a difficult task.I know that some states like Punjab ,Haryana and Tamilnadu have  very good soil information up to soil series level.In the soil series reports information may be available on current crops grown and suggested crops based on soil information(soil properties and fertility status.).I do not know how far this information is used in crop planning and input use.Also as the information becomes old one has to revisit and update the information to make it relevant to current needs of farmers.

  • Roman Mezencev added an answer in Carboplatin:
    What is the optimal exposure time of carboplatin by sensitivity test of cells?

    By chemosensitivity test of cell lines to carboplatin, different exposure time of cells to the drug were described in the literature, typically 3-4 days. Very rarelly, there were also tests with 1-4 hours of exposure time. Can someone tell me what would be the optimal time and why? Thank you.

    Roman Mezencev

    Dear Dan, thank you for your interesting comment. I will be very interested to see the details when they are available (published). There are facts supporting commonality of the mode of action of these two drugs, and there are also some facts  that may imply diversity in their modes of action. In my view, current evidence points more towards commonality of their modes of action. If we consider the role of non-DNA targets, as you suggest, we may reasonably expect some differences due to different reactivity of cisplatin and carboplatin with various biomolecules and that may imply different targets and different associated mechanisms; however, this is true only for their original molecules and once the drugs are activated (aquated) to form reactive intermediates, the differences in their reactivities are minimal, if any. Also their high cross-resistance and high similarity of their profiles across NCI60 panel suggest similarity of their modes of action (importantly, the similarity of mechanisms of drugs that display similar activity profiles across NCI60 cell panel has been experimentally validated in many examples). On the other hand, it will be very interesting to see the new evidence that challenges this conclusion, as it may bring new insight to the pharmacology of Pt-based anticancer drugs. Best Wishes, Roman 

  • David B. Saint John added an answer in Bitcoin:
    Will bitcoins and blockchains supplant financial markets as we know it?

    The development and rise of the bitcoin / blockchain phenomenon has huge implications, positive and negative, on the future of money and global payment systems. Will it be paradigm shifting ?  By decoupling from conventional global benchmark currencies, will it level the playing field for emerging economies

    David B. Saint John

    Certainly, there is that possibility, and you can find proponents of responses along the lines of "Yes", "No", and "Somewhat/Maybe".

    At some basic technological level, it certainly represents a breakthrough (Byzantine Generals Problem) and a challenge (currency or pseudocurrency without a central issuer).  

    In black and/or grey markets, bitcoin and its children have already supplanted traditional currency as a means to conduct business, despite the ability to track transactions through the blockchain.  On this basis alone one might expect its utility to leak into more traditional spaces.  M-PESA shows that even in less developed countries, digital currency can be adopted and used if the critical infrastructure and motive is there.   

    There are certainly grand visions of paradigm shifting associated with bitcoin, often driven by crypto-anarchic visions of the future.  Some have argued, that a dismantling of national currency in favor of a transnational one would mitigate some degree of warfare, whether their vision is one consisting of a controlled society managed for a privileged elite (often described as a "New World Order" scenario in a dark sense) or a vision of a more open and utopian humanity united  looking toward the stars after resolution of resource-based conflict (A happy dream, but perhaps too much to hope for to most people).    As bitcoin is not widely distributed, it is not hard to imagine how a national or global shift to digital currency might create a new 0.1%, with Satoshi (or his heirs) being among them.  

    I guess it's a fun question for discussion which no one knows the real answer to at this point with any certainty.

  • Ruben Alvarez-Fernandez added an answer in DNA Extraction:
    Does Anyone knows the recipe for binding buffer for plasmid DNA extraction and enotoxin removal methods ?

    Does Anyone knows the recipe for binding buffer for plasmid DNA extraction and enotoxin removal methods ?

    Ruben Alvarez-Fernandez

    Hello Prashanth,

    You can refer to this post, there I uploaded some home-made recipes.




  • Santosh Suryavanshi asked a question in Culturing:
    Does anybody have experience in culturing human cardiomyocyte cell lines??

    cell culture conditions

  • Ruben Alvarez-Fernandez added an answer in Agrobacterium:
    Is any pTi disarmed plasmid naturally maintained in Agrobacterium strains without any selection?

    Is any pTi disarmed plasmid naturally maintained in Agrobacterium strains (i.e. GV2260, LBA4404) without any selection? I assume that it should derive from wild plasmid only missing of the T-DNA region, so naturally capable to persist in the Agrobacterium cells.

    Does it strictly imply that cured strain are not (or less?) virulent?

    Ruben Alvarez-Fernandez

    In addition to previous remarks, I'd like to add that Ti plasmids are substantially big (we are talking about plasmids ranging 200 Kb). Therefore, it's much less likely for them to be cured than for helper or binary plasmids. That explains why a selective agent, in the case of Ti plasmids, acts more as an ID to the strain than as a means to keep the plasmid in the cell population.

  • Mera Saad asked a question in Digestion:
    Hello everyone, I had an experiment about the subject below, and I got these results. My professors wants me to write a lab report. I do not know how?

    Carry out the digestion of Lambda DNA (Bacteriophage) and double digestion of Plasmid DNA (pET29(a)+ECD2) using restriction enzymes: HindIII, EcoRI, BstEII, NotI and NcoI.

    I have the protocol, but how can I know if my experiment was right or not? 

    Could you please help me?


    + 3 more attachments

  • Abdelati Reha asked a question in Antennas:
    What's UWB antennas ?

    what are  the conditions to qualify  an antenna as one for UWB applications

  • Duc Phan added an answer in Agarose:
    How to remove spheroids from 96-well flat-bottom plate with agarose?


    I am doing an assay with colorectal cancer cell lines using a 96-well flat-bottom plates with 1,5% agarose and it is forming what looks like spheroids. However the problem is how to remove it from the plate to an eppendorf? I tried different options like a little spoon to try to catch the agarose and hopefully the spheroid too, or to remove it with a pipette but with the pipette it was impossible because it was "stuck" in there simply.

    Can anyone help me please?

    Thanks in advance!

    Duc Phan

    I suggest to use low adherent 96 well plate instead of regular tissue culture treated well plate. you can get from any vendor like Fisher or VWR.

    A better method to make spheroid is using the microwell that stem cell people use to make embryoid body. These are more expensive than normal well plate, but you can generate a lot of spheroids in short time. I use the Aggrewell from Stem Cell Technologies. They sell a 24-well plate that has 8 wells at the center modified to contain 400 microwells. So with 1 shot, you make ~400 spheroids. Link here: http://www.stemcell.com/en/Products/Popular-Product-Lines/AggreWell.aspx

    This method is super easy to do to generate a lot of spheroids at once. The well plate can be reused 2-3 times by washing thoroughly with PBS after harvesting. Hope this helps.  

  • Francisco J Barrantes added an answer in In Silico:
    Is there an easy way to identify lipid-binding domains in silico that are not necessarily trans-membrane helices?

    I was wondering whether it is possible to extract some information concerning the propensity of hydrophobic stretches of sequences to interact with a particular type of lipids? The lipid binding domains do not necessarily have to be transmembrane helices.

    Francisco J Barrantes

    Please find 2 reviews from our own harvest on cholesterol recognition motifs. 



    + 1 more attachment

  • Brahim Sekkaki asked a question in Thermal Evaporation:
    Can anyone suggest to me the deposition parameters for ZnO and AZO thin film on glass with thermal evaporator (from Powder)?

    Can anyone suggest to me the deposition parameters for ZnO and AZO thin film on glass with thermal evaporator (from Powder)?

  • Stam Nicolis added an answer in derivative of operators in time:
    How do we understand a conservation law (Noether's theorem) in quantum mechanics?

    In the classical mechanics Noether's theorem says that

    "if a system has a continuous symmetry property, then there are corresponding quantities whose values are conserved in time"

    As a simple particular case, a quantity A that doesn't depend on time explicitly, neither through other parameters on which it depends, i.e. dA/dt = 0, is a constant of motion.

    The question is what becomes of this law in quantum mechanics (QM)? Does it hold at all? And if it does, what is its meaning?

    The QM gives the following formula for the time derivative of an operator Ȃ:

    (1) dȂ/dt = ∂Ȃ/∂t + i/ħ (ĤȂ - ȂĤ),

    where Ĥ is the Hamiltonian of the system, and Ȃ is a Hermitic operator attached to an observable of the system.

    Assume now that Ȃ doesn't depend explicitly on time and commutes with Ĥ, therefore dȂ/dt = 0. How shall we understand this result? Does it mean that the value of the operator Ȃ is fixed during the system evolution, even if we don't measure it?

    Or, alternatively, does it mean that performing a measurement of Ȃ on identically prepared systems, we are bound to find the same value of Ȃ?

    In other words, in the QM, a quantity which is a constant of motion, possesses a value, and it is fixed in time, independently on whether we measure it or not? Or, alternatively, it takes a value only if we measure it, and the value is the same if we repeat the measurement on identically prepared systems?

    Stam Nicolis

    Please read the previous message. The reason is that the Hamitlonian, as a beam splitter, contains cross terms-that's what a beam splitter means. So it is of the form written in the previous message, with A=/=0 and A^+ =/=0. That's how iit can take an initial state, |ψ> = p|a> + q|b> with |p|^2+|q|^2=1 and send it to |a> or |b>.

  • Ronald Fricke added an answer in Fossils:
    What is the smallest size of an adult vertebrate which ever lived or lives on planet Earth?

    From Contructional and Functional viewpoint it would be interesting to know the smallest size of fossil or living Vertebrate.

    Ronald Fricke

    The small paedomorphic goby Schindleria brevipinguis reaches a maximum size of 8.4 mm, but is very thin and has much less body mass than a frog.

    Watson, W. and H. J., Jr. Walker 2004
    The world's smallest vertebrate, Schindleria brevipinguis, a new paedomorphic species in the family Schindleriidae (Perciformes: Gobioidei). Records of the Australian Museum v. 56 (no. 2): 139-142.


  • Daya Nidhi Gautam asked a question in Leachate:
    Is there a possibility of thermal stratification in a leachate lagoon?

    We do have a landfill leachate lagoon (7m depth) present in subtropical Auckland. The min air temp recorded 1 degree C. There are 3-4 aerators operating continuously but in June (winter in NZ) a low dissolved oxygen level in the leachate was noted and strong odour was present which resulted in multiple odour complaints from the surrounding community. Could it be related to the thermal stratification followed by the overturning of the leachate present in the pond?

    Thank you.


  • Zameer Hossenee asked a question in Gentamicins:
    Does concentration of antibiotic discs matter in antibiotic susceptibility testing?

    Hi. I am currently working on my final year project and the latter deals with antibiotic discs. My question is: " Does the concentration of a particular disk affect the inhibition zone?" For e.g, does a 10 microgram gentamicin disc and a 30 microgram gentamicin disc perform the same way with respect to the diameter of the inhibition zone; that is, do they produce the same diameter of inhibition zone? IF possible I would really appreciate if I can get a breakpoint table for all the discs with different concentrations since I am getting only for 10 microgram disc. Thank you in advance.

  • Hasnaa Aboelwafa asked a question in Stem Cells:
    The better method to separate and culture stem cell for research?

    detailed methodology for separation of stem cell?

  • Arnold Trehub 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.

    Arnold Trehub


    Read the following passage from Metzinger's article:

    "For instance, phenomenally transparent representations are always activated within a virtual window of presence and are functionally integrated into a unified global model of the world. Conscious content is always bound into an experiential “Now,” and functionally it is intimately connected with those mechanisms constituting short-term memory ..." [emphasis mine]

    1. If you actually believe that Metzinger is not referring to a transparent brain representation/model of the world external to the brain, then I suggest that you read more of what Metzinger has published with Blanke, particularly on the subject of out-of-body experiences.

    2. I have repeatedly written on this thread and in my other publications that the pattern of autaptic-cell activity in retinoid space constitutes our phenomenal world.

    3. If retinoid space constitutes our phenomenal world around us, and if our brain is not represented in retinoid space, it follows that we perceive events located in the phenomenal world around us and cannot perceive events as located in our brain.

  • Martha McClain, PhD added an answer in human intelligence:
    When is it best to use row verses column percentages to report research findings?
    I want to report research findings.
    Martha McClain, PhD

    I would suggest checking with your university dissertation manual or publication. I used both in my research findings. I also used graphs.

  • Grant Mitman added an answer in Algae:
    A suggestion for a proposed use of some species of algae?

    Dear all: Looking for a progress in integrating the theoretical framework of a proposal to spread the importance of algae, i am looking for any suggestion for a proposed use of a species,... This is greatly appreciated :).

    Grant Mitman

    which species?what sort of environment?

  • Hasnaa Aboelwafa asked a question in Platelets:
    How can I detect platelets microparticles or platelets contamination in FFP transfusion by flowcytometry?

    to decrease the effect of platelet abs formation in FFP transfusion , the role of flow-cytometry  in detection of platelets micropartcles?

  • Godwin-Charles A. Ogbeide added an answer in Service:
    How can revisit intention in service sector be measured?

    I am wondering if there are any papers dealing with this topic and what scales have been developed for measuring it. It will be great !

    Godwin-Charles A. Ogbeide

    In addition to some points above, some customers, even if they are not satisfy may be interested in revisiting… if the customer-oriented complaint management process can transform displeased clients into loyal customers (Barlow & Moller, 1996). The utilization of a suitable complaint management procedure in hospitality organizations is critical for customer satisfaction and retention (Bowie & Buttle, 2011). Hence, it depends on your questions, objectives, or hypothesis. You may also want to see the methodology section of past studies with similar questions, objectives, or hypothesis to yours.  

  • Adedeji Owonibi asked a question in Research Topics:
    Forensic Audit and Accounting Dissertation question?

    Hello all, i am considering a dissertation in Forensic Audit and Accounting, and wondering what the research topic should be. i need help on which direction deserve a research work and how difficult or otherwise will it be to access materials in this field.?

  • Alejandro Canaza Jorges asked a question in Yarrowia:
    What media can I use for reactivate Candida, Pichia and Yarrowia strains that were conserved three years in glycerol mix under -80C?

    Hi, I'm looking for suggestions and some experience that you already had about similar situations. In the beginning I'll will use Malt Extract. Thank you.

  • Paul Rutland added an answer in DNA Purification:
    Are there some procedures that would allow keeping the DNA integrity after extraction of human cells?

    After performed DNA extraction , the sample obtained is losing very fast stability and  in our laboratory we have the willingness temperature -20° C to save the sample.

    Paul Rutland

    Genomic DNA should store for a long time at 4C if dissolved in alkaline TE. The edta removes magnesium so stops nucleases working and the pH must be alkaline to avoid acid depurination. if this is how you are storing your DNA then sterility could be a problem and a bacteriostat should be added or the samples stored at -20C or,as Prakash says, dried DNA stores very well at ambient temperatures

  • Dejenie A. Lakew added an answer in Strategic Planning:
    What is the difference between a strategic plan and a strategy?

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

    Dejenie A. Lakew

    The strategic plans enable us to carry out the strategy we devised to solve a problem. Compare plan of action and the action.  We therefore devise a strategy and then we develop plans how to implement that strategy so that we act. 

  • Martha McClain, PhD added an answer in Pursuing PHD:
    Is it allowed for a student to have multiple transcripts of records?
    I finished my first undergraduate course in 2006. Then I took up Nursing and MA at the same time. I was informed by our school that I should only have one official transcript of records. Then I planned to enroll in PhD this year but I am concerned that my MA will not be incorporated to my most recent transcript of records. Am I still eligible to enroll in PhD or should I pursue another MA/MS before I enroll in PhD? I'm concerned because I wasn't aware with this rule about transcripts.
    Martha McClain, PhD

    To this date, I have multiple transcripts; for example, a bachelor degree at one school, master and specialist from another university, and a doctorate from a different university. If I include my high school transcript, it would be four. All of my transcripts were excepted! Investigate!!! Perhaps, they want you to finish all of your degrees at that particular university. Good luck!

  • Graciela Reybet asked a question in Chromatography:
    Which method is reliable measurement isothiocynates unused chromatography?
    • or myrosinase activity
  • Anass Elouaddari asked a question in Alkynes:
    Is it possible that the Carbon (CH) of the terminal alkyne does not appear in the NMR DEPT (135)?

    is it possible that the Carbon (CH) of the terminal alkyne does not appear in the NMR DEPT 135), it behaves like a quaternary carbon ?