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  • Rajitha Indukuri added an answer in Restriction Digestion:
    How do I eliminate nonspecific bands in final product?

    I have PRRL-ABCB7, a plasmid (8000 bp) with insert ABCB7 (3000 bp) subculture in top10 cells and purified by Qiagen midi. My work is to cut the insert from plasmid by double digesting it with Age and Mlu I (both from NEB). So Iam digesting 10µg of vector, first with Age in buffer 1.1 and run aliquot in the gel to check complete digestion with AgeI. Then iam purifying the Age digested vector by Ampure magnetic beads and digesting it with Mlu I in buffer 3.1. Running the gel after complete digestion with Mlu. From the gel two separate and clear bands were seen at 8000 bp (plasmid) and 3000 bp (insert), i have cut the band at 8000bp and purified  from gel. But after purification, when I check the final product in gel, along with 8000 bp band I have seen some bands at 7000, 6000 bp. When I am purifying the band from 8000 bp, why I am getting these non specific bands along with my desired product. I have tried so many times with different enzyme concentrations, incubation times, gel extraction kits and running slowly for long time in the gel (low gelling agarose), but nothing works and at the end the product is same. I have attached the pictures. Give me suggestions to eliminate these extra bands ??

    Thank you all in advance.                 

    Rajitha Indukuri · Karolinska University Hospital

    Hi Mark Farman, i have tried cloning, as you said its failure. After plasmid extraction, iam doing digestion with Age 1 followed by Mlu 1. I have extracted the plasmid with qiagen elution buffer (10 mM Tris·Cl). In digestion reactions and purifications iam always using the nuclease free water.  But always ending up with same results and product. how can i overcome this.

  • Paul Adekola added an answer in Cities:
    Please suggest comparative studies of city districts in Italy, post WW2 ?

    I am interested in cases of urban planning that proved successful in their many ( 20, 30, 40) years of history and urban life, as well as changes which occurred along.

    Paul Adekola · Covenant University Ota Ogun State, Nigeria

    You can visit any department of Urban and Regional Planning of any University in your locality then. They should be able to assist.

  • Christopher Gomez added an answer in Channels:
    Does anyone know about channel Sinuosity Index Measurement?

    What should be the minimum/ideal reach length for SI calculation of any sample basin? Rosgen (1996) suggested taking 20 to 40 time of bankfull width of the study reach; this may be too short to examine planform characteristics such as sinuosity.

    We can find the huge variation between reach scales SI as suggested by Rosgen and long reach scale SI calculation.

    Then, what should be followed for better result?

    Christopher Gomez · University of Canterbury

    Please go and see the series of publications on the subject by H. Piegay and Albert, or eventually the book H. Piegay co-wrote with M. Kondolf: 

    Tools in Fluvial Geomorphology edited by G. Mathias Kondolf, Hervé Piégay.

    You will find all your answers in there.

  • Khalid Hassan added an answer in Pearson's Correlation:
    Is it possible to use Pearson Correlation Test for a data base of scale variables and an ordinal variable?

    I am hoping to find a correlation between some samples of routine blood tests taken on the first day of arrival at the hospital for some pacients with community-acquired pneumonia and the number of antibiotics empirically chosen (mono therapy, bi therapy, and multiple antibiotics). 

    Khalid Hassan · University of Diyala

    Pearson correlation used between scale variables , while when your data consist of scale variable and the other was ordinal variable you can use Spearman correlation or Kendal correlation which both depend on ranks not on values its self .

    other situation , if your data has normal distribution and scale in this case you can use Pearson , but if your data has not normal distributed you must use Spearman .

    Good Luck

  • Omer Iqbal added an answer in Platelets:
    Why is a 0.32 M- sucrose phosphate buffer used in the precipitation of glycogen from platelets?

    I'm currently trying to precipitate glycogen from platelets; however, the protocol I have uses ice cold 0.32 M sucrose buffer in platelet isolation process. I just can't figure out why?

    Omer Iqbal · Loyola University Medical Center

    Ice-cold sucrose solution would cause the activation and eventual death of platelets, releasing platelet components including glycogen.  Cold itself can cause death of platelets.  Perhaps concentration gradient due to sucrose in addition to the cold helps break the platelets effectively releasing platelet components including glycogen.

  • Eva Shehi asked a question in Education:
    How can I find some questionnaire about adolescent educational aspiration and parents education level?

    About a research

  • Artur Braun added an answer in Impedance:
    Is impedance electrochemical non destructive ?

    is it possible to apply more than a test of the impedance électrochimical on the same sample while changing the immersion time in a corrosive medium NaCl 3 %

    Artur Braun · Empa - Swiss Federal Laboratories for Materials Science and Technology

    Globally I would say electrochemical impedance spectroscopy is non-destructive - unless you do electrochemistry :-)

    There are cases where you want to study the charge carrier dynamics at electrochemical potentials which may inevitably alter the condition of your sample. Like when you apply positive or negative potentials, you are oxidizing or reducing your samples, and literature is there where it says that such ca destruct your sample, at least the surface. This holds particular for biological samples such as with biosensors.

    When you do Mott-Schottky analysis you do EIS for various potentials.

    Your question is a good one and practical one. I would not discourage anyone from EIS for the mere danger of sample destruction. You simple have to take this into account and proper plan and design the experiment with a multiple of specimen.

    EIS can be destructive.

  • Hugo Alberto Fernández added an answer in Electromagnetic Radiation:
    Do different electromagnetic radiations have different mass?

    different electromagnetic radiations are differentiated on the basis of their energy or frequency of photons.characteristic of  Electromagnetic radiations is, all of them travel with a constant speed, that is of light c which is maximum possible velocity in our universe.

    Now I have a confusion here ; since E=mc2 and c is a constant whether photon of higher energy is having higher mass in comparison to a lower energy photon..?

    Hugo Alberto Fernández · National University of Technology

    Dear Usha, your question refers to an old absurd controversy about the use of relativistic mass. I say “absurd” because the SR theory may be rigorously developed with or without the relativistic mass.
    In 1966 (Taylor and Wheeler) began a current of opinion for to only use the term "mass" with reference to the "rest mass". The main reasons for this attitude were the rest mass invariance with respect to a Lorentz transformation and the four-dimensional space-time approach by Minkowski.
    The controversy acquired its climax in 1989 due to a silly article by Okun, who required forbid the relativistic mass in text books. This article correctly insists with geometrical aspects (Lorentz invariants and four-dimensional vectors) but did not mention at all on physical aspects inherent to relativistic mass.
    Although the Okun's proposal was biased, subjective and arbitrary, it was adopted by the main scientific community. Nevertheless, I am sure that most physicists continue using relativistic mass.

    I will refer about forgotten aspects of such controversy and some opinions here.

    1 – According with “abolitionists” the equivalence principle between mass and energy only is valid for bodies at rest.
    Although this law has not a general deduction (to any kind of processes), it has a rigorous theoretical deduction in relativistic mechanics, resulting:

    E = m0 c2 (1-v2/c2) -1/2 = m c2 , where:

    v is the mass velocity (it is not a LT);
    m0 is the rest mass;
    m is the relativistic mass, also called inertial mass.

    Simple calculus gives:

    E2 = p2c2 + m02 c4 = (mc2)2 , where p is the momentum (p = m v)

    The expression p2c2 + m02 c4 is exactly the same as (mc2)2, no one has priority.
    It is interesting noting, in pedagogical sense, that without the relativistic mass it is necessary a new momentum definition (p = m0 v (1-v2/c2) -1/2).
    Besides, the principle (E = mc2) without restrictions is the unique expression referring to total energy, no other law gives the total energy content of a physical system.

    So, the claim that this important law is only valid for bodies at rest was a fancy and, worst, a mistake, which unfortunately was transferred to several (not all) recognized physicists.
    Anyway, it is a principle which has been experimentally tested without any movement restriction, and physicist, including those who sustain the restriction, applies without limitations.

    2 – The relativistic mass is a “property” of every physical system, a fundamental aspect that was ignored by Okun and followers.
    We say that a physical magnitude is a system property when its closed line integral is null for any closed line (processes), condition that relativistic mass fulfills.
    The knowledge of system properties is fundamental to understand the phenomenon behavior because at least two system properties are modified during any interaction.
    The use of system properties allows a better description of interactions.

    3 – In Modern Physics a real particle has the following three characteristics: energy, momentum and bounded spatial structure.
    The mathematical model of a photon (Fourier integral) fulfills such conditions.
    - E = hv
    - p = hv/c
    - Bounded structure ~ Coherence length
    So, a photon is a particle.

    4 – “Reality” is a subjective concept which depends on different philosophical approaches.
    Physicists consider that reality is according with correct experimental measurements. In this sense, a photon has real relativistic mass (Compton effect) and zero rest mass.


  • James Field added an answer in Teeth:
    With increasing the number of the abutment teeth, can we use Fixed PD rather than RPD in cross-arch long edentulous span?

    Kennedy Class IV.

    James Field · Newcastle University

    Just to throw this into the mix :-)

    Clin Oral Implants Res. 2007 Jun;18 Suppl 3:63-72.
    Ante's (1926) law revisited: a systematic review on survival rates and complications of fixed dental prostheses (FDPs) on severely reduced periodontal tissue support.

  • Sergei A. Ostroumov added an answer in Lymnaea:
    Which publications on ecotoxicological studies on the pond snail (Lymnaea stagnalis) could be recommended?

    This species of water mollusks is one of common species of aquatic ecosystems.

    Sergei A. Ostroumov · Lomonosov Moscow State University

    These are relevant related publications:

    Apr 5, 2015 - ... ‏@Sergeiost Apr 5. Lymnaea stagnalis, #toxicology, great pond snail, ...


    Full text paper, free:



  • Artur Braun added an answer in Superalloys:
    How do I measure oxide scale thickness on alloy other than cross section SEM?

    Oxidation of superalloys.

    Artur Braun · Empa - Swiss Federal Laboratories for Materials Science and Technology

    By the way, is your sample flat with optical quality surface, or is it a rough porous specimen?

  • James Field added an answer in Dentistry:
    Which scoring system for dental wear is the most appropriate for living subjects?

    Trying to develop a simple scoring system for charting.

    James Field · Newcastle University

    Absolutely Khaled :-) I completely agree. For record keeping you might be best using a scale that has more versatility, like Smith and Knight (modified). BEWE is blunt and won't really add any value to your clinical notes, in my opinion.

    Hope this helps!

  • Louis Brassard added an answer in Consciousness:
    How does the subjective consciousness of self emerge?

    I am and I can experience this very well but what is going on to create such a consciousness of myself in early childhood. 

    Louis Brassard ·


    "“To reproduce is to re live"

    To reproduce (simulate) is to re experience

    The two translations conveys the same meaning for me because

    Living and Experiencing means exactly the same thing for me.

  • Guenter Grundmann added an answer in Gold Deposits:
    Is it right to say mesothrmal gold and orogenic gold deposits are one and the same thing?

    I just want to know if its correct to use mesothermal and orogenic gold deposits interchangeably?

    Guenter Grundmann · Technische Universität München

    Dear Mr. Xaba

    The term 'mesothermal' refers to a hydrothermal mineral deposit, formed at considerable depth and in the temperature range of 200-300 degrees Celsius (Park & MacDiarmid, 1970, p.317).
    The term 'orogenic' includes thrusting, folding, and faulting in the higher levels of the earth crust, and ductile deformation, metamorphism and plutonism in the deeper layers (Glossary of Geology, 2.ed.).
    Now you can decide whether these two terms or complexes are interchangeable itself.

    Best regards,

    G. Grundmann

  • 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.

    Marc Tessera


    "Why don't you present what you consider "the most relevant experiments for testing a model of consciousness", and I and others can present what we consider the most relevant experiments and we can discuss the pros and cons. This seems to be a reasonable way to move ahead".

    Indeed I don't feel the most competent to define what might be the most relevant experiments but I would say that the methodology used and the experiments performed by research scientists like Stanislas Dehaene and Jean-Pierre changeux seem quite relevant to me.

    Such methodology and experimental measures of conscious access include:

    1. Sudden, all-or-none ignition of prefronto-parietal networks; 
    2. Concomitant all-or-none amplification of sensory activation; 
    3. A late global P3b wave in event-related potentials; 
    4. Late amplification of broad-band power in the gamma range; 
    5. Enhanced longdistance phase synchronization, particularly in the beta range;
    6. Enhanced causal relations between distant areas, including a significant top-down component.

    "Many of these measures are also found during complex serial computations and in spontaneous thought. There is evidence that they rely on an anatomical network of long-distance connections that is particularly developed in the human brain. Finally, pathologies of these networks or their long-distance connections are associated with impairments of conscious access".

    "In the future, as argued by Haynes (2009), the mapping of conscious experiences onto neural states will ultimately require not only a neural distinction between seen and not-seen trials, but also a proof that the proposed conscious neural state actually encodes all the details of the participant’s current subjective experience. Criteria for a genuine one-to-one mapping should include verifying that the proposed neural state has the same perceptual stability (for instance over successive eye movements) and suffers from the same occasional illusions as the subject’s own report. Multivariate decoding techniques provide pertinent tools to address this question and have already been used to infer conscious mental images from early visual areas (Haynes and Rees, 2005; Thirion et al., 2006) and from inferotemporal cortex (Schurger et al., 2010; Sterzer et al., 2008). However, decoding the more intermingled neural patterns expected from PFC and other associative cortices is clearly a challenge for future research (though see Fuentemilla et al., 2010).

    Another important question concerns the genetic mechanisms that, in the course of biological evolution, have led to the development of the global neuronal workspace architecture, particularly the relative expansion of prefrontal cortex, higher associative cortices, and their underlying longdistance white matter tracts in the course of hominization (see Avants et al., 2006; Schoenemann et al., 2005; Semendeferi et al., 2002). Finally, now that measures of conscious processing have been identified in human adults, it should become possible to ask how they transpose to lower animal species (Changeux, 2006, 2010) and to human infants and fetuses (Dehaene-Lambertz et al., 2002; Gelskov and Kouider, 2010; Lagercrantz and Changeux, 2009), in whom genuine but immature long-distance networks have been described (Fair et al., 2009; Fransson et al., 2007)".

  • Artur Braun added an answer in Electrochemical Impedance Spectroscopy:
    What does current disjunction mean in the electrochemical impedance spectroscopy (EIS) measurement?

    While performing the electrochemical impedance spectroscopy (EIS), frequently encountering the message, current disjunction, on the computer screen from the software of voltalab. My question is what does it mean current disjunction? Does signify anything positive or negative about the coatings on the metallic substrates?

    (see the attached image)

    Artur Braun · Empa - Swiss Federal Laboratories for Materials Science and Technology

    Voltalab 80, we frequently notice this error message. At what potential are you running the EIS? Are you maybe forming a dielectric film on your working electrode (or counter electrode?) and thus chemically disconnect your system? Maybe you could form unwillingly an insulating film on top. Or poor mechanical connection of leads to the system.

  • Fadoua Ataa Allah added an answer in Arabic:
    What are the free or open source Arabic morphological analysers, which we can download from Internet?

    What are the free or open source Arabic morphological analysers, which we can download from Internet?

    Please provide the links.

    Fadoua Ataa Allah · Institut Royal de la Culture Amazighe

    You can try these tools. I hope they help.

    - AraComLex: M. Attia et al., « An Open-Source Finite State Morphological Transducer for Modern Standard Arabic », Proceedings of the 9th International Workshop on Finite State Methods and Natural Language Processing, pages 125–133, Blois (France), July 12-15, 2011.

    - Buckwalter-fst: M. Hulden and Y. Samih, «  Conversion of Procedural Morphologies to Finite-State Morphologies: a

    Case Study of Arabic », Proceedings of the 10th International Workshop on Finite State Methods and Natural Language Processing, pages 70–74, Donostia–San Sebastia´n, July 23–25, 2012.

  • Mohemid Al-Jebouri added an answer in Art:
    Does anyone know how to explain how it is that after the pos-modern style of art, again coming moderm art?

    Modern, has always meant something never seen until the moment of occurrence. Modern, involves looking through "different glasses". Seeing the same phenomenon as no one has seen before. It is modern contemporaries always been a bit "silly".

    Mohemid Al-Jebouri · University of Tikrit

    Dear Prof.Doko;

    One of the characteristic features of your drawing is the creative endlessness cycles among your diagrams which just a reflection of infinity of living,education,arts and nature secrets.They are amezing congragulations to you.

  • Abdulnaser Ibrahim Nour asked a question in Corporate Governance:
    Is their a relationship between principles of corporate governance and liquidity of market shares?

    i mean if you are applying corporate governance the liquidity of market shares will effect.

  • Roman Buchheit added an answer in Graphite:
    What is the conductivity and the optical reflection of metals and graphite?

    Why metals usually have shinning surface and luster? Is there a connection between the optical reflection and the conductivity?

  • Benhlal Youness asked a question in Risk Modeling:
    What are the latest and the most used risk's models in economics ?

    Modeling risk and return 

  • Carlos Adrian Peñaloza Becerra added an answer in FDA:
    Could anybody help me with the guidelines or recommendations of FDA/EMA for the administration of ODT in bioequivalence & bioavailability studies?

    Could anybody help me with the guidances or recommendations of FDA/EMA for the administration of ODT in bioequivalence & bioavailability studies? Thanks in advance

    Carlos Adrian Peñaloza Becerra · Instituto Nacional de Enfermedades Respiratorias

    Do anybody know if a protocol about administration of this kind of dosage forms in clinical studies is available?

  • Jakub Svoboda added an answer in Literature Review:
    Comparing my results with existing research?

    Hi, I would like to know if there is some method how to compare results of my research (qualitative conducted by interviews) with other existing reserach in this area. 

    Example: I have a set of benefits, barriers and motivation factors that resulted from interviews I conducted and now I would like to compare them with the same type of elements in other research.

    I hope that I am clear enough what I ams struggling with..

    Thanks a lot for any suggestions!

    Btw, is there also any method for literature review different than just looking at literature by topic etc. something that gives more academic value?

    Jakub Svoboda · Copenhagen Business School

    Thanks a lot, I will take a look at that!

  • Michael Issigonis added an answer in Capacitor:
    Is it feasible to tap electric from rain water droplets?

    Cloud bears high potential electrostatic charge. Rain droplets are expected to have electrostatic charge on surfaces. If these droplets are collected in electrically insulated large basin (say 1 km radius) having multiple annular metallic walls (without exposing the walls to rain except the inner one) with di-electric in between thus forming electric capacitor, whether this cellular capacitor will store significant electric charges from these rain droplets? Or the atmospheric air will trap all the charges and negligible charge will reach the basin?

    Michael Issigonis · Brandon University

    I think it is definitely worth testing, the pounding itself, if it is on an incline could make a wheel turn and create electricity (like hydroelectricity).

  • James Field added an answer in Teeth:
    Can "Implants AND Natural teeth" be used "together" as abutments to support FPD?

    Taking in consideration all these factors:

    healthy natural teeth, good oral health, and good bone support,

    James Field · Newcastle University

    I agree with most - we teach our students to avoid linking teeth supported with PDL and fixtures osseointegrated into bone. UNLESS the implant restoration is linked to the natural crown with a minor moveable connector. We tend not to prescribe these so often any more, as laboratory experience is waning - but if needs must it is a good solution.

    Hope this helps!

  • Muhammad Siddig added an answer in Social Media in Education:
    Do you believe that social networking is a good education tool?

    Nowadays, social networks are very much in use by almost everybody. In our country, many teachers use Facebook as a communication tool between the students and teachers. Assignments are also upload in Facebook and answers are also sent there, like in the case of fundamentals of research or thesis writing. 

    Are there any similar experience in your country? I would love very much to hear from you. Thank you.

    Muhammad Siddig · Shendi University

    social media applications is the best education tools, because there are a usable and ubiquity with in different levels of ages, also, the time was used in this application is greater than other applications.

  • Edwin A. Locke added an answer in Causality:
    Is a concept of causality required in science?

    John D. Norton characterized "Causation as Folk Science",

    (see http://quod.lib.umich.edu/p/phimp/3521354.0003.004/1).

    Would you say that causality is a well-defined concept that is

    essentially required in science?

    Edwin A. Locke · University of Maryland, College Park

    Thank you Andreas! But I do not see the need to bash ourselves on the grounds that we might discover something new--what is important is what we have learned so far. Those who think they understand the world  are good scientists if their beliefs are based on evidence. We should not judge ourselves by the principle of omniscience--discovery is incremental. Do we know more now than we did in the Middle Ages? Yes. Is there more to learn? Of course. We should be proud of what we have discovered so far. I like to think of science as constructing a building, brick by brick. Sometimes we have to replace some bricks but science moves forward--look at the progress of civilization (with respect to science)!

  • Ivan Bodis-Wollner added an answer in EEG Signal Processing:
    How many types of transform can be used in EEG feature extraction?

    like FFT, STFT,DWT,Stockwell Transform (S-Transform) etc.

    which transform is better and why?

    Ivan Bodis-Wollner · State University of New York Downstate Medical Center

    Ideally you would like to have a signal which represents  action process prior to or overlapping with motor action. CNV could be ideal, but technically difficult. A short lived   burst of osciilatory components, such as gamma or beta , in a relevant time window can be best defined  using time/frequency analysis. Largely unexplored but potentially useful could be to quantify phase shifts in the relevant  frequencies.

  • Flora Todaro-Luck added an answer in Bullying:
    Is "nursery bullying" really a bullying behaviour?

    Hi eveyone! I've been reading about the concept of "Nursery bullying" that refers to bullying behaviours in children under 5's. The more I read about this matter, the more I doubt about its suitableness to bullying definition. 

    Are children under 5 years really able to have intentional bullying behaviours? I'm interested in psychological or isolation behaviours.

    I'm not an expert in children of these ages, can anybody help?

    Flora Todaro-Luck · University of Ulster

    Yes I believe that  children are capable to bullying other as far as in nursery school. This behaviour is probably determined by parents attitude at home. However it can have a long lasting negative effect on The bullied Children. I think that teachers and caregivers should pay a close attention to what happen in nursery school and not discount or overlook it.

  • Rajnish Kumar asked a question in Base Composition:
    Can anyone suggest about reinforced fiber/particle aw 106 polymer based composite?

    Currently I'm working on particle reinforced polymer composite, but unable to find specific application area of this composite?