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  • Radoslaw Jagiello added an answer in Leaf Area Analysis:
    What is an instrument for measuring leaf thickness via a non-destructive measure?

    We are looking for some instrument for non-destructive measuring leaf thickness. Can anybody recomend instrument for this kind of measure ?

    Radoslaw Jagiello · Polish Academy of Sciences

    Maybe it's a best solution. There is a lot of instruments like this, but those with resolution +/- 0,001mm are very expensive (digital ones). There are few sizes of pressure elements - also with diameter ~5-6 mm, so the problem with thick veins could be resolved (in case of "my" leaves). Thanks for all answers.

  • Mohammed Impelee added an answer in Micronutrient deficiencies:
    Why the malnutrition rate has been incresing in most of Subsaharan African countries nomatter all the nutrition programmes?

    Why the malnutrition rate has been incresing in most of Subsaharan African countries nomatter all the nutrition programmes?

    Mohammed Impelee · Otterbein University

    Food insecurity is the number one factor alongside lack of good nutritional knowledge in most African communities. Plant based diet for instance to some degree is available and affordable in most African communities and yet they don't utilize them.

  • Daniele Sasso added an answer in Special Relativity:
    Is the neutrino rest-mass a reality, or is an illusion?

    I am no specialist in the topic of neutrino flavor oscillations, but I examined a lot of articles, theoretical and experimental, on this topic. And the result is that I remained with doubts on whether the neutrinos really have a rest-mass.

    Here are some of my doubts.

    1. The velocity of the neutrino is extremely close to that of the light. The theory of the flavor oscillation requires, in order to be able to see such oscillations, to have  r = ct, where r is the distance travelled by the neutrino and t the travel time.

    2. The extremely low values found for the presumed rest-masses ~ 10-3eV (i.e. 1.7x10-35gr.)

    2. In a correct quantum treatment of the neutrino, i.e. as a wave-packet of limited dimensions, the neutrino is never considered at rest. A particle at rest has linear momentum ZERO and can be anywhere in the space. But, until now, nobody produced a neutrino at rest, while an electron, a proton, a muon, and others, can be set at rest.

    3. The values of the elements of the Pontecorvo–Maki–Nakagawa–Sakata matrix which connect the flavor states of the neutrino with the mass states, are not precise, and experimenters rely on some elements measured in some experiment, for measuring other elements in other (different) experiments.

    Does somebody know whether there are alternative explanations of the neutrino flavor oscillations, without assuming rest-masses for neutrino?

    Daniele Sasso · Progetto Indipendente ARS

    Matts, I have a critical view in regard to modern and postmodern physics but for you it is pure nonsense. Your speech has a false start. Modern physics historically begins from the Michelson-Morley experiment untill to the theorization of the Standard Model. Postmodern physicists are in continuity with modern physics and they think critical research is pure nonsense. Critical research just is a characteristic of contemporary research that strives to exit from crisis in wich postmodern physics is. You have the right to don't understand or don't accept it but I not will use insults towards you.

  • Max Emmanuel added an answer in Electrostatics:
    Could the fundamental dimension of Electric Charge be Mass only?

        After solving dimensions of electrical equations, I found out that the fundamental dimension of Electric charge is mass only. This also leads to the derivation of dimensions of other Electrical units like Electric Current, Magnetic flux density etc in terms of Mass, Length and Time only. These are not cgs units.
         This discovery can help unify the force of gravitation that uses mass and the electrostatic force(Force between charges).This will help contribute to the theory of everything, also in better understanding of the electrical units and equations. e.g Work done=Charge times Voltage. Substituting the right handside with their dimensions of Charge=Mass and Voltage=L^2T^-2 proves that the equation is dimensionally consistent. Also other theories can be uncovered and better understood with this finding.
         I wish to be challenged if possible and I will show the steps of the derivation.

    Max Emmanuel · Makerere University

    Stam, charge and mass are both properties of matter, all have field properties then why is it that mass stays the same in all dimensions and yet charge changes.

     I would prefer a relation basing on the standard MLT physical dimensions. Anyway from your conclusion in two dimensional space charge is equal to mass. So the conclusion is that charge is equal to mass.

  • Rashmi Gangwar added an answer in Gel Documentation System:
    Has anyone used the PCR machines and gel documentation systems made by Labnet?

    These equipments from Labnet look very enticing, but oddly, seem very unpopular, as none of my colleagues knows about them, and I could not find any customer reviews. Any feedback highly appreciated.

    Rashmi Gangwar · Indian Institute of Technology Roorkee

    i have used a PCR machine from labnet and the results were pretty good. Yes it is not that popularly used but  it is ok.

  • Andrea Sanchez asked a question in Fixatives:
    IHC for CD3, CD4 and CD8 with frozen sections or PFA?

    Dear Collegues, 

    I have been trying to do an IHC in lungs with both frozen (non fixed before freeze) and tissues fixed in 4% PFA. I am not having positive results with any of these methods. Can someone share a protocol or some advice with me. I am using Santa Cruz BT antibodies. 

    Thank you

  • Musfique Ahmed added an answer in Microbial Fuel Cell:
    What are the best options to generate bacteria in a microbial fuel cell (MFC)?

    In MFC, bacterias work as catalyst to oxidize organic and inorganic matter and generate current. Electrons produced by this bacteria are ultimately transferred to the anode. I need some help regarding the ways which actually use in MFC to generate or produce bacteria in MFC.

    Musfique Ahmed · Independent University, Bangladesh

    Thanks Mr. Yahampath.

  • Mohd Khalid Khalil added an answer in Animal Feed:
    How can I calculate Metabolizable energy in Rice Polish?

    This is the formula I want to know,

    ME = (35x crude Protein + 85 x crude Fat + 35 NFE )

    NFE = 100 - (Moisture + Crude Protein + Crude Fat + Crude Fibre + Ash)

    I want to calculate ME for rice polish,wheat, Soya Bean Meal and any other raw material for animal feed specialy for poultry.

    1) I want to know if above equation is correct or wrong ?
    2) How they derive 35, 85 & 35
    3) any Book related to this subject
    These are My Questions.

    Mohd Khalid Khalil · University Malaysia Sarawak

    Hi guys, can i use the same formula to calculate the energy in fish feed?

  • Phil Troy added an answer in Discrete Event Simulation:
    Does anyone know what is the best software tool for develop a discrete event simulation?

    There are free and paid tools that develop discrete event simulations , in particular we are looking for one that is easy to use but at the same time contains all the functionality required for such simulations.

    Phil Troy · McGill University

    I agree with Alexander (mostly).

    How to design a simulation is a bit of a challenge.  With most simulation packages you do it from a flow chart like approach.  Which I happen to think is not a good approach, except for smaller simulations.  If it is a small simulation then Simul8, arena, anylogic, . .  are all fine.  I did try out extend one time but didn't like all the wires on it (connectors between simulation blocks), but it essentially captures the same approach.

    A better approach, in my opinion, for larger simulations is to use an object oriented design and then implement it using an object oriented tool.  (I am not talking about object oriented in the manner that Simio presents itself as being object oriented, I am talking about the way programmers think about object oriented.  If you can program in SSJ (from Pierre L'Ecuyer at the University of Montreal), that is a good approach and free.(Please see my winter simulation conference presentations/proceedings)  I also hope to have an object oriented set of tools based on what I have discussed in my presentations/proceedings but they are in progress.

    Good Luck.

    Phil Troy

    Philip M. Troy, Ph.D.

    Process & Quantitative Decision Support/Systems Analyst
    Les Entreprises TROYWARE

    Adjunct Professor of Surgery
    McGill University

  • David Sacks asked a question in DNA Ligation:
    How many streptavidin per Dynabead?

    How many streptavidin molecules are on each magnetic Dynabead and DNA ligated streptavdin beads? Can one saturate a bead or a 96 well plate with SA? 

    Would culturing naive B-cells in this environment under selective/proliferative conditions result in the evolution of higher affinity BCR?

  • Andrea Sanchez added an answer in Immunohistochemistry:
    IHC-Why non-fixed section for CD4 and CD8...
    Hi, everyone. I am going to do IHC to stain CD4, CD8, CD3, MHC II in brain sections, and I was told by my superviser that non-fixed section should be used.
    But in papers that I had read, PFA fixed sections were used, only in this paper 'The Inflammatory Reaction Following 1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine Intoxication in Mouse' they used non-fixed section(free frozen section) for MHC II, but PFA fixed section for CD4 et.al.
    Can anyone tell me is it true that non-fixed section should be used for staining for lymphocyte? Why is that? Any other cases that non-fixed section should be used?
    Many thanks.
    Andrea Sanchez · Colorado State University

    Hi Ariel, did you have any luck with your IHC? I am doing an IHC with non-fixed frozen sections for CD3, CD4 and CD8 but I am not having positive results. I was wondering if you have a protocol for these IHC in frozen sections that you can share with me. it will be a lot of help. 


  • Kamarul Mansor added an answer in Exploratory Factor Analysis:
    If you have Positively and Negatively Correlated items in the same factor, is it possible to separate them into two factors?

    I am completely new to the performance of factor analysis and any insight would be much appreciated.

    I have performed an exploratory factor analysis on the Situational Motivation Scale (SIMS) as part of my on-going research. I was expecting to obtain 4 factors (as per the scale) but instead I obtained 3 with two of the factors in the same factor (one factor positively correlated and the other negatively correlated).

    I have attached a word format of the table obtained. Any guidance at all would be very much appreciated. Thank you in advance for any responses

    Kamarul Mansor · Universiti Teknologi Mara (Kedah)

    Dear Kathleen,

    Looking at your output attachment, I do agree with Prof Muayyad.  What I suggest that you try to re-code the response for the items with negative correlation (i.e., items for Identified Regulation) and fixed the number of factors extracted to 4.  Try it and see if the result suits what you really needs.  Good Luck.

  • Tiek Aun Tan added an answer in Sulfur Acids:
    How do I prepare a 0.01 M Sn(II)SO4 in 4M H2SO4 plating solution?

    I have problems with what I think is hydrolysis.
    I;ve tried adding tin sulfate into sulfuric acid then boiling it under agitation, and
    adding tin sulfate into boiling sulfuric acid but I still have a whitish cloudy solution either way. The precipitate settles down after a day.
    How do I get a clear solution for use in electroplating?

    Tiek Aun Tan · Universiti Malaysia Perlis

    Good day Prof Muralidharan.

    Unfortunately, red tape and the lack of funds, and time will prevent me from obtaining tin citrate. I must make do with tin sulfate now.

    Thank you. 

  • 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.

    Louis Brassard ·


    ``I disagree as for me a belief imposes itself on the person (e.g., religious beliefs).``

    If the person believe something, whatever the method: explanation , brain washing, indoctrination, beating with a stick, water boarding, enhanced interogation techniques, whatever method, that something becomes the person's belief.

  • Aditya Rao SJ added an answer in Autodock:
    Using autodock tool is it possible to dock two different peptides at a binding site of a receptor?

    I want to dock two different peptides with a receptor simultaneously. Then I need to create a PDB file of two peptides (in one PDB file) by different softwares (like avogadro), which I think is not possible (as per my knowledge). So, what's the solution for docking two different peptides at a binding site of a receptor?

    Aditya Rao SJ · Kuvempu University

    Please go through the following link

  • Ognian Marinov added an answer in Charge Transport:
    How does charge carrier hopping depend upon the dimensions of nano-structure?

    using VRH or ES model for semiconductors

    Ognian Marinov · McMaster University

    The shortest paper on your question that I know is

    G. Paasch, T. Lindner, S. Scheinert, "Variable Range Hopping as Possible Origin of a Universal Relation between Conductivity and Mobility in Disordered Organic Semiconductors", Synthetic Metals, 132(1), 97-104, 2002

    Even so, you still need good luck... In a year you will know why I write so.

  • Gaurav Kumar Singh added an answer in Agarose Gel:
    How do I get higher molecular weight band after PCR clean up followed by gel extraction of double digested inserts?

    It's confusing to find extra bands of higher molecular weight in my insert sample which was PCR purified by gel extraction method. The insert bands were very clean in 0.8% agarose gel. It was followed by double digestion with NheI and HindIII enzymes at 37 degree overnight. During the second round of gel extraction after digestion, I found two bands-one equivalent to my insert size and another band higher than my insert.

    Can anyone has suffered the same problem? Please give your inputs.


    Gaurav Kumar Singh · IIT Kharagpur

    @Augusta Jamin- thanks for your suggestion. I have one doubt, even if i have used the same razor to cut the insert and vector, will it be possible that razor will contain such a high detectable amount of vector in the gel?

    @Jacques Davy Ibaba- Ho do I get undigested vector in my insert sample? It was gel purified PCR product after digestion.

  • Sheikh Adil Edrisi added an answer in Soil Science:
    Which methods are used to measure the bulk density of different soil depths?

    I want to measure the bulk density in three depths (0-10, 10-20, and 20-30 cm).  for 0-10 i use from volumetric ring (5 cm of internal diameter and 10 cm of height). Can I measure bulk density in 10-20 and 20-30 depths with this ring? 

  • Martin E. McBriarty added an answer in Crystal Structure:
    Can anybody please explain me the following figure ?

    Where i can get basic details regarding the point groups of symmetry elements in an hexagonal crystal (wurtzite crystal structure), comparatively easier texts are preferred, kindly suggest.

    Martin E. McBriarty · Pacific Northwest National Laboratory

     Although it's from a baffling source (the "Britney Spears Guide to Semiconductor Physics"), this page gives a straightforward explanation of the relationship between real space (including symmetry elements) and reciprocal space, leading to the construction of the Brillouin zone and the identification of some special points (as shown in the image you posted).

  • Frank Gräbner added an answer in Antennas:
    How can I minimize horn device antenna in consideration of dielectrics?

    hello everybody,

    how can i minimize horn antenna with dielectrics materials in condition that the loss be little and gain does not decrease incredibly

    thanks for notice

    Frank Gräbner · Hörmann IMG

    Dear Sir,

    you can calculate the resonances of the horn antenna with the geometry. Then you can use a dielectric material what have a great eps´´(f) - a good Absorption - in this resonance frequency.

    This Absorption dielectric material you can use for a better horn antenna.

    All the best

    F. Gräbner

  • Zeljko Stojanov added an answer in Qualitative Data Analysis:
    I am looking for help with regard to " How to identify themes" in qualitative data analysis?

    I experience difficulties to determine the themes when it comes to qualitative data analysis, case study method. Any pertinent links, concepts or files, Pls share me ! 

    best regards, 

    Zeljko Stojanov · University of Novi Sad

    actually all approaches for analyzing qualitative data are based on identifying themes (maybe named differently).

    The most straightforward approach for identifying themes is thematic analysis. You can find detailed process for thematic analysis in article:

    Virginia Braun and Victoria Clarke (2006) Using thematic analysis in psychology. Qualitative Research in Psychology, 3 (2). 77-101. DOI: 10.1191/1478088706qp063oa. [available at Internet]

    Very similar approach for thematic analysis, with detailed description of data analysis process you can find in article:

    Jennifer Attride-Stirling (2001) Thematic networks: an analytic tool for qualitative research. Qualitative Research, 1(3), 385-405. DOI: 10.1177/146879410100100307. [available at Internet]

    You can still use the general inductive approach described in article:

    David R. Thomas (2006) A General Inductive Approach for Analyzing Qualitative Evaluation Data. American Journal of Evaluation, 27(2), 237-246. DOI:10.1177/1098214005283748. [available at Internet]

    Of course, more complicated, but powerful approach is grounded theory. For example:

    Kathy Charmaz. Constructing Grounded Theory: A Practical Guide through Qualitative Analysis. Sage Publications. 2006.


  • Vinay Baranwal added an answer in RNA-Seq:
    For RNA-seq on rice, which reference transcriptome database should we use?

    We got RNA-seq done on rice (Nipponbare). The sequencing facility aligned the reads to the reference transcriptome (Ensembl Oryza_sativa_japonica IRGSP-1.0). Ensembl database does not match rice database at MSU as far as Gene/Locus ID goes (http://rice.plantbiology.msu.edu/index.shtml).

    Ensembl nomenclature is different than MSU database. What is the easiest way (other than BLAST) to see which gene in MSU database corresponds to Ensembl ones. In general, when people do RNA-seq on rice, which reference transcriptome/genome database they use to align the reads?  I am not happy with the annotation/gene description of Ensembl database. Please let me know. Thanks!

    Vinay Baranwal · University of Delhi

    Well thats an interesting situation.

    Its not very surprising to see these many numbers of differentially expressed genes.

    Now to analyze these differentially expressed genes to come to a conclusive point, you have to use some enrichment analysis based on functional connotations.

    Here are the steps you should follow which I feel could be relevant to give you some hint.

    1. From the same site of RGAP, download the GO (Gene Ontology) slim IDs of your differntially expressed genes.

    2. Use Cytoscape along with BINGO plugin to get those GO which are significantly enriched. THis will give you some information about your genes based on their categorization in different GOs.

    3. Finally you have to identify some key genes based on your expectations that in what pathway your mutated gene in question is sitting and how does it is regulated. In what way it is regulating the various developmental aspects. Like for example if there are any link to homeotic genes in your downregulated set of genes. Also you could identify some genes which controls cell division and its expansion. Like BRI1 etc.

    This answer is a hint about how you can proceed. Basically you have to find needle in haystack. These techniques and tools has been used to make the haystack size smaller.

    All the best ahead.

  • Gaurav Kumar Singh added an answer in Bacterial Cloning:
    What is the best way to select and confirm clones prior to sequencing?

    This is a very basic problem while selecting clones. Sometimes double digestion fails to give insert fall off but PCR does. What should be the most prudent way to overcome the dilemma over selecting right clones? Please give your valuable inputs.

    PCR or restrction digestion or combinatiion of both?


    Gaurav Kumar Singh · IIT Kharagpur

    Thanks alot to vevryone for your valuable feedback. 

    @Panduranga Rao- your suggestion is helpful.

  • Frank Gräbner added an answer in EMI:
    Is there unwanted effect of double shielding of EMI source in Faraday cage?


    I have a plan to make new version of Faraday cage for gas discharge circuit. Unlikely to current cage in which radiation sources such as Thyratron and capacitor are just proximate to some electronics related to discharge triggering, This new box will have additional shielding room for these sources as seen in the attached images.

    At this moment, I don't know which is good way to get more effective shielding. one image (1st case) shows additional shielding room shares one side to whole Faraday cage while the another (2nd case) is isolated type which is connected to inner surface of the cage via wire.

    In 1st case, What I'm worrying is the possibility that EMI directly hits the cage thus cages are all fluctuated in voltage if EMI is severe.

    Actually EMI is severe. When we enclose the capacitor with aluminum foil, foil is shaken!

    Could you tell me anything about these two design?

    In 2nd case, does external surface of the isolated shielding room keep itself equipotent no matter what happens inside?

    Frank Gräbner · Hörmann IMG

    Dear Lady,

    of course we have unwanted effects. We have the resonances in the Farraday shielded box. It is important, that you know the geometry and the mode and the source frequency, so you can calculate the resonance frequency. In this resonance frequency the shielding have lower values. This is bad.

    All the best

    F. Gräbner

  • P A Azeez added an answer in Didactics:
    Which are, in your opinion, the most important issues of modern didactics?

    Didactic has long been constructed as a separate field of study, and today is probably the most advanced pedagogical discipline. However, not only in my opinion, but in opinion of most famous educators in the field of teaching and didactics are expected in the present and near future many fundamental review. Compared to most other inherited or new components of school and many relations that exist within the school system, teaching is essentially little changed, although it is constantly upgraded, refined, modernized, etc.

    P A Azeez · Salim Ali Centre for Ornithology and Natural History

    Teaching should be a means to show the large vista of knowledge available for the youngsters to choose and pursue. It in effect should train them to explore and learn for themselves. But the teaching methods have been predominantly reduced to just "teaching" the young ones how to think and live and work as a 'normal' human beings - it is in fact 'normative' and largely not 'innovative' and 'liberating'.  There has been changes, but that are very scarce and not commonly accepted, perhaps the society is more promotes "status quo".

  • Rashmi Gangwar added an answer in Electrophoresis:
    Anyone there to explain?

    Is it ok to use DNA molecular weight marker in RNA electrophoresis? Or only RNA molecular weight marker should be used  to see RNA integrity?

    Rashmi Gangwar · Indian Institute of Technology Roorkee

    preferably you should use an RNA ladder that would give an exact size of your RNA

  • Tiek Aun Tan added an answer in Electrolytes:
    If I use a non-aqueous electrolyte, with a minor component of water, (around 10 - 30%), should I use a non-aqueous or aqueous reference electrode?

    Which one is more accurate for electrochemical analysis?
    Contamination from water is not important but I am worried if the measured potential will be inaccurate.

    Tiek Aun Tan · Universiti Malaysia Perlis

    Good day and again thank you for your replies.

    Dear Samaras, yes, they all are very good proposals in my opinion also. I may understand wrongly, but do you mean that I should check the performance of different reference electrodes in my electrolyte by chronopotentiometry? What should I look for?

    Dear Indra, I intend to use methanol as my organic solvent. Do you suggest against the use of DMSO as the electrolyte itself or in the salt bridge as suggested by George?

    Thanks again. 

  • Suresh Chandra added an answer in Milk:
    What is effect of formalin on raw milk properties if used more than recommended 40% amount?

    Please accurate answer if available

    Suresh Chandra · Sardar Vallabhbhai Patel University of Agriculture and Technology

    Thanks Laxmana naik g

  • Sundararajan S added an answer in Alginate:
    After nitrogen bubbling, how long will the oxygen dissolve in the DI water?

    If the DI water was first bubbled with nitrogen to remove oxygen, and alginate was dissolved in water with stirring during 12 hours, is it possible any oxygen would be dissolved in the alginate solution?

    Sundararajan S · National Institute of Ocean Technology

    Dear Wang,

    What do you mean thick solution? is it high viscosity or high density ?