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  • Does anyone have references on quality of learning services in ubiquitous learning environment and methods used to compute it?

    Does any one have references on quality of learning services in ubiquitous learning environment and methods used to compute it ?

    Ines Bayoudh Saâdi · École Nationale supérieure des Ingénieurs de Tunis


    Thank you really it is helpfull

  • How can I find an image formed by the maximal disc along a skeleton?

    this is required for thinning algorithms

    Gulshan Goyal · Chandigarh University

    thanks for you answer. i am trying the same. Sir, can u plz help me what new can i add in thinning area.

  • Can anyone explain to me what MolProbity does?

    Furthermore, I would like to know if the new hydrogen added and optimized model is to be used for evaluation or should I keep on working with the original model? 

    Thank you. 

    Mohsin Lone · Central University of Gujarat

    Dear Aparna!

    MolProbity will provide you summary statistics of your model. Although, this online webserver is very easy to handle but, remember that it context -sensitive.

  • Muhammad, Israr asked a question in Nano:
    Uterine cancer in women?

    What are the major causes of the uterine cancer in the aged women and are the nano technology of chemotherapy are suitable methods for its treatment. 

  • How much work must an external agent (by means of a torque applied to the molecule) do to rotate water molecule from theta= 0 to 180°?

    For example, a water molecule (H2O) in its vapor state has an electric dipole moment of magnitude 6.2*10^-30 C.m.

    How much work must an external agent do to rotate this molecule by 180°, starting from its current position, for which theta= 0?

    What do you think about the below calculations?

    The work done by an external agent (by means of a torque applied to the molecule) is equal to the change in the molecule’s potential energy due to the change in orientation.

    Wa= U180 - U0
         =(-pE cos 180) - (-pE cos 0)

         = 2pE = (2)(6.2*10^30 C.m)

         = 1.24*10^-29 J

    Maher A. A. Abdelsamie · Putra University, Malaysia

    Dear Jesus E Mora Ramírez,

    Thank you for your comment . The two articles below validate the effects of low intensity electromagnetic fields on water and its hydrogen bonding network. 


    2- https://www.researchgate.net/publication/244506290_Experimental_evidence_of_a_microwave_non-thermal_effect_in_electrolyte_aqueous_solutions?ev=prf_pub_bmark

    You said " The more energy you apply to the molecule, the more spin or angular momentum you get."   I agree with this.
    but i can't agree with what you said " it is very difficult to say that a water molecule got spinning in consequence, since in liquid phase"   because it is the opposite of what you said previously.

    If the low intensity electromagnetic radiation will not rotate water molecules, you have to explain the mechanism of interaction between low intensity radiation and water molecules from your point of view.  Do you know the mechanism ?

    Best Regards

  • Nisha Shankhwar added an answer in Fiber:
    How can I prepare the samples using electrospun fiber mats for XRD measurements?

    XRD measurements of electrospun fibers.

  • What is rapamycin dose for live animals?

    i want to use rapamycin in my control group of hamsters infected with prion...whats the recommended dose?


    Nastaran eizadi-mood · Isfahan University of Medical Sciences

    Dear Colleage,

    This is not in my area of speciality. I'm managing acute poisoning cases and work on that area.



  • Muhammad, Israr asked a question in Calculations:
    Multicollinearty and primary data?

    How to calculate Multicollinearty in primary data and how to overcome this problem in research.

  • Kay Wong added an answer in MS/MS:
    Can anyone advise me on GC mass spectrometry for metabolomics?

    MS or MS/MS?; single quad or triple quad?

    As a newbie, I find it puzzling with the many different configurations a GC-mass spectrometer can possess (for metabolites identification and profiling).

    I would appreciate it a lot if you could please enlighten me on a few questions below:

    1.      Is the same concept in LC-MS/MS proteomics transferrable to the field of GC-MS or GC-MS/MS based metabolomics? E.g., GC-MS/MS allows one to achieve additional structural confirmation, while triple quad allows one to perform targeted analysis of selected metabolites, etc.

    2.     Would you mind sharing with me the system you are using for routine metabolites identification and profiling, preferably with a “all-in-one functionality”?

    • (e.g. Would a triple quadrupole GC-MS/MS system the most applicable to process a much broader types of metabolites, and could fulfill the needs for most diverse scenarios of metabolomics experiments)? Just like the latest QTOF or Orbitrap mass spec which allows one to do protein/peptide quantification, quantitation; discovery, as well as certain level of targeted (MRM) analysis on the same instrument.

    If there is one such "comprehensive" GC mass spec, it would be a useful starting point for me to focus, consolidate, and read more on the literature related to its applications.

    Appreciate your advice. Thank you very much.

    Kay Wong · The University of Hong Kong

    Hi Mark,

    Thanks for your advice on lipids analysis.

    Have a nice weekend!

  • Nisha Shankhwar added an answer in Electrospinning:
    Does anyone know what factors influence the elongation of fibrous membranes which fabricated by electrospinning?

    In my experiments, some different electrospun membranes were fabricated from the PHB solution with the different solvents. And the results showed the solvents have the obvious effect on the elongation of these fibrous membranes. For investigating the mechanism,what characterizations should I do?

  • Is there evidence linking oil palm production to soil degradation?

    In Mesoamerica, oil palm plantations are often assumed to cause land degradation, mainly compaction, and the drying of soils. I have not found scientific literature proving this link. Are there any studies on this?

    Antonio Castellanos-Navarrete · Wageningen University

    Hi Sara,

    I will check the publications you mention. It would be great to have the paper on soil changes once is published.



  • Arshad Sultan added an answer in Gastroenterology:
    Any suggestions about treating a patient with Toxic Mega colon ?

    11 year old is admitted due to Toxic mega colon , colon diameter 7 cm . Started with i.v steroider , anti biotics , NPO and TPN . Due to insufficient response , is given Infliximab yesterday

    1. How many days it takes before one can see response to Infliximab ?

    2. After how many days , another medisine like Cyclosporin can be tried ?

    Arshad Sultan · Vestre Viken Hospital Trust

    First dose of inlfiximab is given and expecting response with in 72 hours . If pt does not response  within 72 hours so cyclosporin can be tried ? Anybody has experience about this . One study showed that a group of pt who did not respond to infliximab ,   33 % responded to cyclosporin . Group of pts who did not respond to cyclosporin 40% of them responded to infliximab...

  • Juliana Okoro added an answer in Nursing Education:
    Nursing Care Plans Rubric?

    Hi, I'm in the process of working on my Capstone for my Master's in Nursing Education. I would like to create a standardized rubric to use across all three levels of clinical, and I need 30 research articles to support it. Does anyone know of any good resources? 

    Juliana Okoro · Walden University

    Hi Janiece, here are two resources I have found:Boateng, B.A., Bass, L.D., Blaszak, R.T., & Farrar, H.C. (2009).The Development of a Competency-Based Assessment Rubric to Measure Resident Milstone. Journal of Graduate Medical Education, 1(1): 45-48. Retrieved from www.ncbi.nim.nih.gov/pmc/articles/PMC2931941
    Eymard, A.S., Davis, A & Lyons, R. (2013).Progressive Clinical Education Tools Based on the Quality and Safety Education in Nursing Competences. Journal of Nursing Education and Practice, 4(2): 116-122. Retrieved from www.sciedu.ca/jnep

  • Thor Friis added an answer in MrBayes:
    Any advice in mixing datatypes (DNA and protein) and species in MrBayes?

    I'm doing phylogenetic analyses on my favourite gene and I've decided to use DNA rather than protein since the former gives me better resolution in the vertebrates. Besides vertebrates, my GOI is also found in molluscs, invertebrate chordates, the freshwater hydra, as well as Naegleria gruberi (an amoeboflagellate) and some 30+ bacteria and counting.

    The problem I have encountered with nucleotide analysis is long branch attraction with some of the invertebrates. The Neagleria in particular is bouncing all over the place. When I use protein sequences, without exception, the bacteria are at the base, followed by Naegleria, hydra, protostomes, invertebrate chordates, cartilaginous fishes, and so on. 

    Is it possible to use protein sequences for the basal species and nucleotides for the vertebrates? I've looked at the "cynmix.nex" example in the MrBayes 3.2 manual but it's not the same problem. In that example they used the same taxa with two data types (morph and DNA). In my case I want to try protein for 45 invertebrates and DNA for 170 vertebrates. I can aligned it in Clustal and get an interleaved data file, but how do I tell MrBayes what data type is with what taxon?

    Anyone got some experience with this in MrBayes?

    Thanks in advance.

    Thor Friis, PhD

    Queensland University of Technology

    Thor Friis · Queensland University of Technology

    I'll check out Exabayes--thanks for the link Fabricius.  I'll see if get the IT crowd downtown to set it up on their high performance computers. As it happens the guy in charge is good colleague.

    I've set up two codon model analyses on MrBayes on my desktop. I aligned the sequences in MEGA using both Clustal and Muscle and running the following parameters in MrBayes:

    begin mrbayes;
    set autoclose=no;
    lset nucmodel=codon omegavar=ny98;
    report possel=yes;
    report siteomega=yes;
    mcmc ngen=1000000 printfreq=100 samplefreq=100 nchains=4 nruns=2 savebrlens=yes diagnfreq=1000 stoprule=yes stopval=0.0099;
    sump relburnin=yes burnin=0.25;
    sumt relburnin=yes burnin=0.25 contype=halfcompat showtreeprobs=yes;

    You're right about the codon model being slow Artur--both runs still got 377 hr to go so I'll definitely have them run on the HPC come Monday. Sixteen days for a mere 1 million generations; if I'm going to wait a couple of weeks for results then I may as well run the analyses for at least 50 million generations or so.

    But even after a mere 38,000 generations the tree topologies are looking quite decent. I take intermittent peeks at the trees by copying the *.t files and making trees using the TreeAnnotator program in BEAST1.8.  

    And while the codon models are chugging along, I've got a GTR nucleotide analysis running on the same data set, but this after I tidied up the Naegleria sequence. I edited out rubbish sequence both fore and aft that had zero homology with metazoan species, but which still left me with over 80% of the coding sequence. That should reduce the LBA artefact considerably. The preliminary trees at 3 million generations are looking promising.

  • Can I use Mincer's earnings function as a research model?

    My research scope is to measure the contribution that University education brings to an employee's (annual salary).

    From what I've studied, Mincer's earnings function is the commonly used function for this kind of estimation.

    It's form is:

    lnY = lnB + aED + b1EX + b2EX2 (+ disturbance)


    Y --- salary of employee with univ. degree

    which is explained by:

    B --- salary of employee with base education (for example, high school degree)

    ED --- number of years of univ. education

    EX --- number of years of work experience (which is calculated "age - total formal education - 6)

    Now.., I am at a point where I have received the needed questionnaire data and I am able to figure Y, B, ED and EX.

    For the sake of the argument, let's assume that:

    1. sample size BA degree interviewees is 500 people.
    2. sample size of High School degree interviewees is 400 people.
    3. Interviewees of both samples are roughly in the same age group: 30 to 40 years old, with a mean of 37 years of age)
    4. assuming that a BA degree lasts roughly 5 years, variable "ED" would be = 5
    5. assuming that BA degree interviewees start work at roughly 23 years of age, variable "EX" would be 37 - 23 = 14

    so we have:

    Y = $65000/year (average of 500 BA degree interviewees)

    B = $52000/year (average of 400 high school interviewees)

    ED = 5

    EX = 14

    Plugging in the numbers, we have:

    lnY = lnB + aED + b1EX + b2EX2

    ln(65000) = ln(52000) + a*5 + b1*14 + b2*14

    My goal here, of course is to solve for a. a would basically tell me the percentage of earnings deriving solely from those 5 years of university education. But in order to solve for a, I need to have the values of coefficients b1 and b2 given. And I don't have those...

    Maybe SPSS calculates them automatically once the dataset variables are entered in the program? If yes, to what specific quesions in the quesitionnaire will these two coefficients be connected? Because I feel I need to pay very much attention to including those questions.

    Is it even possible to plug this equation into SPSS? Or any other statistics program for that matter? Or I am following a "dead end" in this case?

    Your thoughts are very much appreciated. Thank you.

    Benjamin H. Wiseman · Lincoln University New Zealand

    If you want to know the effect of  university education (and/or other covariates have) on one's annual salary you could simply do a linear regression. 

    In R it'd be:

    yourData = read.csv("C://pathToYourData//data.csv")
    mod <- lm(salary ~ education + [otherCovariate] + [otherCovariate2], data = yourData)
    To do stuff like square or take the log of a variable in R wrap in like this: I(vairable^2) 

    I'm telling you how to do it in R because in the long run it's better than SPSS. 

  • Kumari Priyanka asked a question in Soil:
    Soil carbon is influenced by which factors in coal mine regions?

    Around coal mining regions,where there is a possibility of coal particles or carbonate or some other contamination of soil, Can all these affect organic or inorganic carbon of the soil?

    Is these contamination hindered with soil carbon analysis? 

  • H Chris Ransford added an answer in Heritage:
    Can a Society really be Established and Sustained on Ignorance?

    The threatened, and in sadly too many cases destruction of world heritage sites by religious fundamentalists robs not only our generation of knowledge and culture but those to come.  

    This is not a new phenomenon, iconoclasm ironically predates the latest outbreak many centuries before Islam, so this cannot be a manifestation of Islam in any form. 

    Can a society or civilisation be established and sustained on ignorance and dogma or is it doomed to fail?

    H Chris Ransford · Karlsruhe Institute of Technology

    Andras, I kindly disagree.

    If politicians know about mathematical modeling applied to economics, they are not going to commit the egregious mistakes committed by many, such as Mao and others, who implemented economic reforms which simple math modeling would have shown were nonsensical, and which indeed led to widespread misery, much lowered standards of living, and in some cases starvation.

    If politicians knew about evolutionary biology, they would not turn into racist monsters as some sometimes do

    If politicians knew about brain structures left over by man's evolutionary process, they would understand about the ancient tribal imperatives still embedded into our brain structures and they would not believe that people with other religions or whatever should be slaughtered, as many still blithely do today. As an added benefit that they will cast a better educated eye on the limitations of man's made up models of reality, inevitably flawed and/or incomplete, and also understand the differences between Godhood and religion.

    The list is absolutely endless.  A firm grounding in objective science should be a requirement for people in positions of power. I could not care less if they know chess. A horrible little Austrian politician with a ridiculous moustache owned 6000 books and had read most - all of his books vaporous ridiculous musings by folks who did not have the slightest hard science background, and therefore pontificated about racial superiority and economics and whatnot - all of which musings would have been destroyed instantly by straightforward application of simple hard science.

    The list is endless, and it has always been thus throughout history. Incas were sacrificing thousands of teens yearly lest the sun god, in high dungeon at the absence of blood, refuse to rise in the morning. The priests killed away ... all with the best of intents - protect the crops and society - because they were crassly ignorant of simple astronomical science. We are still there.

  • Minh Tran Anh asked a question in Couplers:
    After going through an optical directional coupler, the light at the cross port gets a 90 degree phase shift. What is the physics behind?

    After going through an optical directional coupler, the light at the cross port gets a 90 degree phase shift. What is the physics that causes the phase shift?
    Most of the time, people take it for granted but could we have an intuitive explanation for that?

  • Matti Kummu added an answer in ArcMap:
    How can I merge TRMM (Rainfall data) with elevation so as to see the relationship?

    Is there any way in Arcmap where pixels of DEM or TRMM may be assigned each others values based on spatial location?Or some other software as matlab would have to be used?

    Matti Kummu · Aalto University

    Dear Sharma,

    I find Matlab or R the easiest softwares to calculate the relationships between two rasters. Particularly if you have many time steps and want to do sofisticated statistical analyses. 



  • In a buck converter does the output current relate to max input current of the source?

    In a buck converter which is designed for x ampere and y voltage in output, Is the input source needs to have same or more current capability for feeding x amperes? or if the total power was equal it could work!?

    e.g. Input Source (24V, 5A DC) and our next stage Buck (10V, 10A DC)

    Hamidreza Nasiri · Sharif University of Technology

    Thank you everyone. Yes all of your answers are correct especially the good explanation of Adly. 

  • What advantage of international division of labour will contribute to development of cross-border regions between 2 neighboring countries?

    Cross-border regional development

    Richard Croucher · Middlesex University, UK

    Ok thank you for the clarification Choen.  That is a massive question.

    There are clearly some very different ways in which the international division of labour can operate and that means that the context will be very important.  The content of the international division of labour within or between companies and countries is not a static phenomenon but a changing one and how it relates to the development of regions is the outcome of negotiated interactions within and between companies and countries, not to mention regional government as a player.  At the global level and within MNCs, a good illustration of that negotiation is contained in Peer Hull Kristensen and Jonathan Zeitlin's book Local players in Global Games (Oxford University |Press 2004). 

    Some of the most important issues in the developmental effects at the regional level are likely to be: (1) the nature of the industries involved.  Where there are relatively high levels of technology transfer across the borders (not very common although equally far from unknown) and (2) where these transfers are encouraged effectively by state policy one can see that the possibilities of cross-border mutually interdependent regions developing in positive synergy will be higher.  Where the industries operate within a ''low road' (low technology, low pay) paradigm these possibilities still exist but the developmental effects will be reduced.  The earnings issue is quite important here because where there is combined development of a cross-border region based on low skill, low tech and low pay the impact on regional development will be reduced compared to the opposite model simply because workers capacity to raise levels of consumer demand will be reduced, thereby reducing the developmental effects.  The aim really needs to be to develop clusters of companies (especially relevant with small companies) so that they can pool and share resources that they could not individually support. 

    Its all a question of combined but uneven development.  The political playing field is probably more level in South-South cooperations than in MNC-local subsidiary interactions.

    I hope that helps a bit


  • What is the effect of sex hormone and sebum in Acne fulminans?

    Dear Sir,

    I need to know,whether the increased secretion of sex hormone in the body induce the production of sebum and intense to play a substrate for bacterial growth.

    How the bacteria protect from immune system.

  • Are there any peak shifts that happen in powder XRD by changing the solvent to grow crystal of same starting material? if yes what is reason?

    Different solvent grown crystals are subjected to Powder XRD

    Devanarayanan Sankaranarayanan · University of Kerala

    The question seems to be interesting. Whatever be the solvent used for crystal growth it is a fact that a single crystal grown will have its unit cell, i.e. crystal structure unaffected. This means its XRD pattern will be unique (i.e., the same).

  • Vini Bains added an answer in Nursing Research:
    How we can promote nurses to get involved in research?
    What are the strategies that has been followed by hospitals in Europe in promoting nurses to research?
    is it so that Indian hospitals require only patient care from nurses rather than in promoting research?
    Vini Bains · Vancouver General Hospital

    Just do it! The best way to learn about research and appreciate it is just to jump in and do it. 

    One thing that has been done for a while in my neck of the woods is the Research Challenge. It is a small grant $5000, that is specifically for nursing and allied health to conduct a research study.  It is a team's grant. Potential teams submit first a letter of intent, they are then matched with a research mentor that is committed to help the team, and the teams must attend a series of compulsory and optional workshops on literature search, grant proposal development, ethics etc. before submitting the final proposal. I believe this year there is funds to support 18 teams at our facility. It is quite amazing what past recipients have accomplished with these small grants. they have turned into ongoing research, larger projects, masters thesis, and organization wide QI projects. Here is the website for this current year's competition. Feel free to contact the team at VCHRI for more information. I have found them to be incredibly supportive.



  • Can I use Gauss Model to predict TSP's emission concentration from concrete batching plant in rural area near plant ?

    I wonder, can i use Gauss Model to predict where and how high the concentration of TSP's emission from concrete batching plant in rural area near plant?

    Because in those areas, wind direction is different in every hour but there is a dominant one. Wind velocity almost stable but in a range of 0 - 4 m/s. Is it too low?

    Or is there any other model to predict concentration of air pollutant in rural area? Can you give me any recommendation models to predict concentration of air pollutant (especially for Total suspended particulate) in rural area?

    Your answer is a great help, thanks a lot researcher

    Khotimah Ratna Indradjanue · University of Indonesia

    yes, i mean it Sharad

  • How can I measure the rise time of a pulse using nuclear electronics?

    I would like to measure the rise time of the pulses of a silicon detector using a multichannel analyzer, I'm wondering if I can use the timing output of a preamplifier like ortec 142, because it's a differential output and the rise time it's proportional to the derivative of the signal, but I don't know how to put this into a multichannel, What kind of amplifier should I use? Any suggestion is welcome. Also any combination of TAC, CFD or anything.

    Bashir Bashiri · University of Isfahan

    use a spectroscopy amplifier and select your shaping time.in case of high activities shorter shaping time 

  • Behrouz Zarei asked a question in Abaqus:
    Abaqus initial stress defininig in version 6.10?

    hi there,

    is there any one who can tell me is initial stress in predefined load exist by own in abaqus 6.10 or we shoud define it in subroutine?

  • How do you improve research involvement at a community hospital not traditionally involved in research?
    What strategies have institutions used to successfully implement a research program from "the ground up"?
    Vini Bains · Vancouver General Hospital

    One thing that has been done for a while in my neck of the woods is the Research Challenge. It is a small grant $5000, that is specifically for nursing and allied health to conduct a research study.  It is a team's grant. Potential teams submit first a letter of intent, they are then matched with a research mentor that is committed to help the team, and the teams must attend a series of compulsory and optional workshops on literature search, grant proposal development, ethics etc. before submitting the final proposal. I believe this year there is funds to support 18 teams at our facility. It is quite amazing what past recipients have accomplished with these small grants. they have turned into ongoing research, larger projects, masters thesis, and organization wide QI projects. Here is the website for this current year's competition. Feel free to contact the team at VCHRI for more information. I have found them to be incredibly supportive.


  • Can heavy metal soap in 100 PPM scale damage gas chromatography column or parts?

    I have oil sample containing 100 PPM copper soap and some colleagues suggest to perform glycerides content analysis using GC with HT column, but I feel worry if that metalic soap can harm the instrument. Please, tell me whether if this is truly risky or not. I also open to any suggestions on sample pretreatment steps. Thank you for any responses.

    Mario Vincenzo Russo · Università degli Studi del Molise

    Dear Eugene
    thank you very much
    Best regards

  • Stefano Quattrini added an answer in Gravity:
    Does a gravitational field have energy density like an electric field?

    Some physicists believe that gravity is not a real force like the electromagnetic or the strong force because an inertial frame of reference eliminates the effects of gravity.  However, it can be argued that a body in free fall in a gravitational field is just experiencing offsetting forces.  The gravitational force is being offset by the inertial “force” because of the accelerating frame of reference.  The acceleration also produces an offsetting rate of time gradient and an offsetting spatial effect.  One way to prove that gravity is a true force is if a gravitational field can be shown to possess energy density. When two masses undergo unsymmetrical acceleration, they emit quadrupole gravitational waves that definitely possess energy.  A similar acceleration of two of the same polarity charged particles produces quadrupole EM radiation.  Therefore, does a gravitational field possess energy density? Does gravity exert gravity?

    Stefano Quattrini · Ordine degli ingegneri della provincia di Ancona

    Thierry De Mees

    " I also suppose that everyone can agree that the action of attraction upon a mass is exerted by that (detected) gravity. So, work has been exerted.
    If one can agree upon that, then there must be a gravitational energy density present at that time."

    The gravitational energy density exists and can be seen also as a local consequence of the warpage of the hypermedium (space-time). Eddington said in his space time and gravitation:

    "Density multiplied by volume in space gives us mass or, what appears to be the same thing, energy. But from our space-time point of view, a far more important thing is density multiplied by a four-dimensional volume of space and time; this is action."

    There is an energy density in any case locally, othewise there would not be any action, no motion, gravitation would not be able to move anything.

    But according strictly to GRT such energy cannot be localized for the Einstein principle of equivalence, (which I gently refute). The EEP  is not the EP or Newton EP which was experimentally demostrated by Lorand Eotvos. The EP can be for sure be incorporated into Gravitaton, regardless of the theory.

    The EEP is the derivation Einstein made, assuming the WEP (direct consequence of the Newton's second law for falling bodies) and the Local Lorentz Invariance which gives rise to other problems.

    It is interesting how necessary is to get rid of the EEP for the correct coupling. See the publication below.