Q&A

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  • Dominique Casajus added an answer in Editing:
    How do I edit a publication already listed?

    How do I edit a publication that is already listed under my name?

    Dominique Casajus · French National Centre for Scientific Research

    Dear Julie

    you can go to this publication (by clicking on the title), and then you will see, under its title and your name, the following line (in blue):


    Add supplementary resources    Download    Generate a DOI       Edit

    Go to "Edit".

    All the best

  • Hamid Reza Lashgari added an answer in Machining:
    Which material is added with aluminium to improve machining parameters?

    Which material is added with aluminium to improve machining parameters.

    Hamid Reza Lashgari · University of New South Wales

    Generally, ceramic particles are to be added to improve the hardness and wear behavior which makes the machining very difficult through regular methods and other methods such as electro discharge machining should be used. Graphite particles might be helpful since it is soft and provides lubrication ;however, wettability is poor and it needs to be coated with active elements such as Ti to improve wettability.

  • Middela Siddartha asked a question in Econometric Modeling:
    How to estimate the future traffic estimated on a corridor using Econometric modelling??

    I need the Procedure.. :)

  • Robert Anthony Watson added an answer in Special and General Relativity:
    Could gravitational source provide a fixed reference frame for the speed of light measurements?

    I have wondered if a gravitational source could provide the fixed reference frame for the measurements of c? There is, at least one, experiment which could prove my hypothesis wrong, I mean an object moving relative to the center of a gravitational source, and object has a light source on it and at least two photon detectors at the same distance from the light source opposite to each other (in-line with the light source).

    Synchronized clocks (on the object) are attached to the detectors so that we can record the time when photons hit them. Let's even restrict the object's movement so that it occurs on Earth's idealized spherical surface.

    If the object moves so that the line connecting the detectors and the light source is parallel to the object's heading then according to my hypothesis there should be different times on those clocks when light from the source has first hit the detectors. I can't find an experiment (described above or equivalent) which would rule my hypothesis wrong.

    Other kind of experiments wouldn't disprove my hypothesis, would they?

    Robert Anthony Watson · The University of Manchester

    Kimmo. But you seem to be assuming absolute Newtonian time, so of course there will be conflicts with SR. but all of SR. You need to explain time dilation if SR isn't assumed and you are providing something more at a more fundamental level to explain it.

  • Christopher Mumbere added an answer in AMOS:
    How can I interpret standardized regression coefficients?

    Hello all,

    I am quite new to SEM and i am struggling to understand how to interpret some of the output. I am using Amos to investigate the impact of business size on RFID technology adoption. Business size is a latent construct defined by indicators such as "Number of employees", "Annual turnover", etc. I have run the model and have obtained the regression coefficients. As can be seen in the attached file, the direct relationship between business size and RFID has a path loading of .64 (which i understand to mean amount of change in the dependent variable per SD change in the predictor variable). However, how do i interpret the path loadings leading from the latent construct back to the indicators? Are these path loadings directly relating to the dependent variable as well?

    Many thanks as i await your response(s)

    Christopher Mumbere · Kampala International University (KIU)

    Normally when a regression model is computed in most of the Statistical packages, unstandardized and standardized coefficients will be displayed . in a simpler way, standardized coefficients portray "modification of the data" or standardization. To make an interpretation of these values, depending on the unit of measurement of the explanatory and explained variables, a unit change in the explanatory variable leads to a "unit standard change" in the explained variable Ceteris Peribus. 

  • Tomasz Szmidt added an answer in R Programming:
    How to learn "R" in an easy way?

    Could anybody please tell me how I can learn R programming. I have found some manual and online guideline but it seems harder to me. I need some definite protocol and formatting data which can generate graph or plot or histogram for example. 

    Tomasz Szmidt · Institute of Fundamental Technological Research

    I learned R from this classical document (well, a past version, it was 10 years ago) "An Introduction to R", see the attachment. In fact, we were asked by our statistics lecturer to read this at home, and after that we started using R during our classes.

  • Witold Orlik added an answer in Mplus:
    What does it mean we control for another variable in multiple regression?

    In multiple regression on SPSS or Mplus I have two predictors

    1. Years in education

    2. Years of working experience

    Based on those two I am predicting annual income. 

    I have two coefficients for predictors (both significant). So I report that one of those two is a significant predictor of annual income while controlling for the other predictor. But what exactly does this mean - "CONTROLLING FOR".

    Thank you for answers

    Witold Orlik · University of Ulster

    Thanks t everybody for explanations. They were very helpful. 

  • Matt Colloff added an answer in Soil Science:
    What is the "shelf-life" of the knowledge in your field?

         For centuries now, our educational system at the university level has been based on the idea that in 4 or 5 years after high school, we could give students all the information they will need during their whole career. This assumes that students actually remember some of what we teach them (that is a big "if", contradicted by the very little research done on the topic). But it also assumes that the knowledge we give to students has a "shelf-life" at least equal to the average career length of our students (roughly 40 years). This second assumption has been questioned not just by education specialists but also by discipline specialists themselves, who consider that in their field, knowledge becomes obsolete much faster than 40 years. In the sciences, the number of 5 to 10 years has been advanced as more realistic... In my own field of soil science, it is clear that some things are evolving very rapidly... In the last 15 years, the perception of what humid matter is in soils has evolved dramatically. So has the importance of soil functions or ecosystem services, and the view of soils in society... What do you think? What is the "shelf-life" in your field?

    Matt Colloff · CSIRO Land and Water

    Hi Philippe, thanks for a very interesting and challenging question. From the perspective of the "shelf life" of the content in the fields of research I'm involved in, it stretches from very long for invertebrate taxonomy (I regularly cite publications from the first half of the 19th Century in my papers) to very short for environmental genomics and adaptation climate change (definitely in the five-to-ten-year category, if not less), with my main discipline base of ecology somewhere in between, depending on research activity in its numerous sub-disciplines. But on the process side, and relating to how (rather than what) students get taught at university, the skills they pick up in critical and systems thinking will last a lifetime, if they have enlightened lecturers who recognise these can be applied to almost any content and context. With hindsight, two of the things I would have found invaluable in my later career to learn more of at university would have been philosophy of science and some basic grounding in political science and economics. These would have taught me to think and act differently in relation to my main discipline base of ecology. I am now making up for lost time. Kind Regards, Matt

  • Manish Kuchya added an answer in Mortar:
    Dose the following statement in the ASTM C1439-13 standard mean that the flow should be between 205 mm and 215 mm?

    It is specified in the ASTM C1439-13 that the amount of water should "produces a flow of 105 to 115 % when tested according to Test Method C1437." Does this indicate that the flow of the test mortar should be around 205 mm to 215 mm when tested according to C1437?

  • Jana Harizanova added an answer in Mitotracking:
    Does anyone have a mitotracker or ER tracker staining and late an immunofluorescence procedure?

    I'm using the mitotracker and ER-tracker in live cells. Later I do the fixation and immunofluorescence protocol to the golgi. When I go to analyze in confocal microscopy, it seems like that the staining to the both trackers and golgi colocalizes, such as a cross-talking of the fluorescences. Does it normal? 

    Jana Harizanova · Max Planck Institute of Molecular Physiology

    Hello Ricardo,

    Would you please write the cat. number and the company for the ER tracker. 

  • Ane Ripoll-Zarraga added an answer in Stochastic:
    How can I calculate technical efficiency of each household in the STATA?

    I used sfcross command to estimate stochastic frontier of production function.

    The example of STATA command :
    sfcross lnYield lnLand lnChemfer lnLaborloc lnMachineryh if Typology==0
    predict e,u

    I wonder if the value of e represent the technical efficiency? I really doubt it.

    Ane Ripoll-Zarraga · The London School of Economics and Political Science

    I see, in this case you have the option for cross sectional data also. 

    Good luck

  • Thinley Dorji asked a question in Plant Production:
    What are the optimization parameters and sizes for the bio-gas plant in the production of Bio-gas?

    Optimization of bio-gas plant layout.

  • Cenap Özel asked a question in Matrices:
    Is anybody interested to max-plus algebra and matrices?

    Max-plus operation, matrices, generalized inverses.

  • Jenisha Suberi added an answer in Bamboo:
    Can anyone help me on how to find the age of a bamboo?

    I am doing a project on using bamboo as reinforcement, but I am not able to find any article on how to find the age since it's said a bamboo gains it's strength at the age of 3 and loses as it gets older.

    Thanks

    Jenisha Suberi · Abertay University

    Thank you for the suggestion Edwin. I am from Bhutan and we don't produce glulam here. It is not in use here. I changed my topic now since there was lack of equipment to conduct some test.

  • Desouza Blaise added an answer in Soil Chemistry:
    How do I measure soil microbial C,N & P using fumigation?

    We are trying to measure microbial C,N and P from rather small soil samples. We reviewed several methods  based on chloroform fumigation. However, the methods to flush the C, N and P are using different solutions (typically KSO4 for C & N and  NaHCO2 for P). Are there any methods that allow washing of all three elements from the soil using the same solution for flushing the soil?

    Desouza Blaise · Central Institute for Cotton Research

    Frank, If the soil is in the alkaline range, a separate extraction for P is suggested and F may not replace P from the soil complex. Thus, two different extractions may be needed. It may work if the soil is in the acidic range as Paul suggests.

    Best, Blaise

  • Ishag Adam added an answer in Malaria:
    What is the impact of Malaria and HBV coinfection?

    HBV and Malaria Endemicity overlaps in a number of geographical regions , a fact that might affect the malaria infection.

    Ishag Adam · University of Khartoum

    Thank  you very much  Gasim

  • Sedi Salimian added an answer in Band Gap:
    Does anyone know about band gap extraction from (lnR-1/T) curve?

    Usually we extract the band gap of semiconductor material from linear part of temperature dependent of resistance (lnR-1/T ) curve, where the curve is exponential in whole range.

    My question is " can we extract band gap from a curve ( lnR-1/T) which is linear in whole temperature range"?

    Sedi Salimian · Kharazmi University

    Thank you so much

  • Chen Shanqiao asked a question in Visual Modeling:
    How to visualize a SVM model on 2D plot with the separation hyper-plate in R?

    We know the score plot of PCA can clearly show the visualized model. Is there such method of plotting for SVM?

  • Shuichi Shinmura added an answer in Integer Programming:
    IS there a theory of perturbations in integer programming?
    Could anyone help in finding information regarding this concept?
    Shuichi Shinmura · Seikei University

    Do you mean a stochastic programming? 

    See the explanation of it on HP of LINDO.

  • Abuzar Baqir added an answer in Phase Change:
    How do I can measure Phase Shift?

    Dear fellows, as electromagnetic waves pass through one medium to another medium its phase is changed. How do I can measure its phase shift?

    Abuzar Baqir · National University of Malaysia

    Thank you so much Yuriy Pigun.

  • Truptimayee Behera added an answer in Comet Assay:
    Why the comet assay was visualize in fluorescent microscope not in gel documentation as stained the slide with Et-Br?

    Why the comet assay was visualize in fluorescent microscope not in gel documentation as stained the slide with Et-Br?

    Truptimayee Behera · Central Institute of Freshwater Aquaculture

    Thank you so much for your suggestion .I must do the silver staining procedure.

  • Praveen kumar A asked a question in THz:
    Do anyone know where the facility of drop mass impact test available in india?

    am in need of performing low velocity impact test of samples using drop mass setup with velocity upto 15 m/s and mass of 50-100kg.plz suggest whether thz machine is available in india.

  • Abdul aziz Jaafar added an answer in Electrostatics:
    How can I model a 3D fixed fixed beam under electrostatic force to calculate the pull in voltage?

    Hello

    Could anyone help me on the modeling of a fixed fixed beam under electroestatic force to calculate the pull in voltage?

    i am beginner in Comsol and i want to model the beam with specs that attached.

    if anyone has a prepared file before like this project it can be helpful.

    thank you

    Abdul aziz Jaafar · Universiti Malaysia Pahang

    Dear Amir

    I think you need to model the material behaviour as part of the process.  Maybe you have to look at the constitutive equation and choose a simple material model before processing to a more realistic material model.. This may need an experimental measurement on the stress strain relations.

    You may need to look at Lagrangian description for the equation of motion and introducing the electrostatic force as a body force.

    The experimental measurement should give you an indication about the relatiosnship between voltage and deflection, and you may need to have a lookup table for that purpose

    Aziz

  • Vishal Giri added an answer in Glucose Transporter:
    Are Glucagon levels elevated in patients with familial glucosuria ?

    Inhibition of the glucose transporter SGLT2 with dapagliflozin in pancreatic alpha cells triggers glucagon secretion. is the same efect in patients with familial glucosuria?

    Vishal Giri · Teerthanker Mahaveer University

    http://www.medscape.com/viewarticle/812072_12      This might be of help.

  • Ben Sharp asked a question in Chitin:
    Deacytlation of chitin to chitosan without using sodium hydroxide or hydrochloric acid possible?

    Does anyone know of a procedure that doesn't involve either of these chemicals?

    This company claims they have a patent pending on the process but I can't find it > http://tidalvisionusa.com/press_kit/

    Thanks, Ben

  • Pham Viet Hung added an answer in Conventional PCR:
    Anyone familiar with smear after pre-QPCR with Cawthon 2009's tel primers?

    I have been trying out Cawthon 2009's telomere primers with conventional PCR before moving forward to QPCR: 

    http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2647324/

    After running the DNA product out on a gel I am getting a smear, vs a fixed single-length product expected from these primers according to the paper. Any one else have these issues?

    Pham Viet Hung · National Hospital of Pediatrics

    If the condition quite specific, the problem might come from two common ways:

    - The yield of your PCR very good, all product cannot pass well during electrophoresis, like traffic jam. 

    - Two much template was added, then you have a mix of your PCR product and extra DNA from extraction, and non-specific binding.

    As I read the reference, SYBR QPCR Fig.2, had high background (above 500), they may have same issue with you, but did not describe.

    The solution: try do serial dilution of your samples, and check a good concentration. Or more simple, add less PCR product on electrophoresis (2-5 ul)

  • Prashanta Kumar Pal added an answer in Microscopic Techniques:
    How do I prepare slides of Collembolans for microscopic photos?

    I need to prepare slides of Collembolans for microscopic photos.  I need to know about the fixative also. 

    Prashanta Kumar Pal · Mangalayatan University

    Dammini, Hi!

    If I understand correctly, you are asking :How you can go for photographic output (Slides etc) of your sample of Collembolans? Isnt it ? IIf yes, then I will follow-up with possibilities in next communication of mine.

    Best wishes

    Prashanta Kumar Pal

    prashanta_p@rediffmail.com

  • Raj K Shankar added an answer in Journal Impact Factor:
    Usually, open access journals have higher impact factor, but lower reputation. How to evaluate these journals? How to choose journal for your paper?

    professors and PhD researchers

    Raj K Shankar · Entrepreneurship Development Institute of India

    A dilemma that seems to haunt the entire researcher population!

    I believe that we should choose journals based on the alignment between paper's topic and journal's aims and objectives. For every paper that we write, I am sure there will be journals at every level (A*, A, B, C and some without ranking too). There are also open access journals. Choose the highest journal that you think meets your alignment challenge. Read a number of papers. Write well and submit there. If you are not accepted, go to the next lower ranked journal and so on. If you go through this exercise regularly, over time you will quickly recognise which level of journal will fit the paper right.

    But some conditions when you choose journals to submit your work:

    1. Ensure they have a good editor/editorial board.

    2. Ensure that they have a review mechanism which will give you feedback.

    3. Ensure they publish according to their aims and scope.

    Submit to journals that have a strong review framework. Even if it takes time, even if they reject your paper, at least the paper will have a chance to be improved upon. Publishing is not necessarily the only goal in research, high quality publishing is. There is a certain amount of learning and joy that comes from revising and rewriting too. Experience it.

    Just my thoughts! Hope you find it useful. Best wishes with your writing and publishing efforts.

  • Matteo Cassotti added an answer in 3D-QSAR:
    Can anyone suggest free tools to perform QSAR?

    How to interpret the QSAR results?

    I want to start from Descriptor calculation, 2D and 3D QSAR studies, free tools for QSAR and its result interpretation. Looking for researchers who can guide me for the same.

    Matteo Cassotti · Università degli Studi di Milano-Bicocca

    I would add to the previous suggestions PaDEL for the calculation of molecular descriptors and binary fingerprints (http://padel.nus.edu.sg/software/padeldescriptor/). It is based on the Chemistry Development Kit library (CDK). I think there is also a plugin for KNIME, since it was suggested.  Never tried but there are some tools here, as well: http://www.scbdd.com/chemdes/

    Another free patform that allows to import data, calculate descriptors (also from very good commercial software like DRAGON) and build QSAR models by different methods is OCHEM (https://ochem.eu/home/show.do). There can be limitations to what you can export, but you can work online and have your models stored there.

    Regarding the interpretation of the results, that part is up to the researcher, not the software. I try to interpret each molecular descriptor of the model (both what information it encodes and what it tells me about my specific dataset), than I link this with my QSAR model. If I have coefficients, then I know the contribution of each descriptor in the calculation of the property. If I don't have coefficients (e.g. if I'm using kNN or other methods), I usually use plots. These can be scatter plots if I only have 1,2 or 3 descriptors or, if I have more, a principal component analysis (PCA). Then I color the compounds by their response (either class or quantitative response) and again try to understand the relationships between descriptors with the response.