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  • Josef Punčochář added an answer in PID Control:
    Opamp - Integrator has been saturated if the input voltage is D.C, why?

    Dear Friends,

                            Currently i am designing a closed loop system using a PID controller in Analog (usign OPAMP), the basic objective to maintain a constant D.C voltage across a load, if i give the input of PID controller as D.C voltage (the difference between set voltage and the reference voltage), the OPAMP(integrator) has been saturated. So, what is the solution to built a PID controller for D.C voltage control.

    Josef Punčochář

    The integrator gives a zero voltage, if the mean value of the input signal is zero.

  • Jochen Wilhelm added an answer in Bayesian Analysis:
    Can Bayesian methods be used to account for possible bias (of uncetrain size and direction) of the data?

    The usual Bayesian analysis takes a prior and updates it to a posterior, using some given data (and a probability model -> likelihood). The prior represents what we already know (believe) about the model. There is nothing like an absolutely uninformative prior, but there can be priors with very high information content (like sharp peaks at a particular hypothesis).

    Now consider the experiments to measure the speed of light from Michelson and Morley. The data shows systematic differences between runs and experiments. Given we knew this variability and performed only a single experiment, how could we include the knowledge about the variabilty between experiments? I suspect that this should give wider credible intervals.

    As I understand do "non-informative priors" like Jeffreys prior still assume that the data is "globally representative", so the posterior tells me what to expect given my particular experiment, but it ignored that I know that a further experiment would likely give me a different estimate.

    I know that a possible solution was to actually perform several Experiments, but here I want to consider the case that I have some konwledge about the variability between experiments but that I can not actually perform several experiments [due to contraints on availability, money].

    Another example: a hospital investigates the effect of a particular treatment of its patients. The data is representative for this hospital, but it is well known that the effects will vary between hospitals. If this information is available (at least approximately), is it possible to consider this in the analysis of the data that was obtained only from a single hospital?

    Jochen Wilhelm

    Thanks, Keith, the paper looks interesting. I need to digest it...

  • Jai Ghosh added an answer in DNA Extraction:
    Any advice on why there is no band on gel for sample, but band for +ve control and poison PCR?

    I have crushed up woodlice, serial diluted and spread plated and have growth of fungus on SDA+antibiotics.

    I have also done a DNA extraction and run PCR with fungal primers, bacterial primers and have no band for the woodlouse DNA, I ran a poison tube with woodlouse DNA and the positive control and I got a band, meaning there is no inhibitor in the woodlouse DNA.

    For the DNA extraction I used a kit that said to elute into DES water, I found that the samples degraded in the fridge so eluted into TE buffer, would this cause a problem, some has mentioned TE buffer being a chelator and may bind to mg and prevent the extraction from working?

    I have no idea what to do now, anyone know why it may not be binding to the primers?


    Jai Ghosh

    I would suggest that since you have been advised to use DES water. Try it. You have seen that due to binding of EDTA in TE buffer to Mg it is inhibiting your reaction.

  • Yan Teck Ho added an answer in Nanocapsules:
    Does anyone know a cationic polymer like Eudragit RS-100 for Nanocapsules, but biodegradable?

    I will start to work with nanocapsules and need to use a cationic polymer, like Eudragit-RS100. But, we will spray dry these nanocapsules to use in pulmonary route. As we know, Eudragit RS-100 is not a good candidate because it is not biodegradable and can be stored at the pulmonary branches. Anyone know a polymer like EUDRAGIT - RS100, but biodegradable? Thanks in advance.

    Yan Teck Ho

    Poly-L-Lysine (PLL) is another possibility

  • Niek J M Opdam added an answer in Tooth Crown:
    To crown or not to crown endo-treated teeth?

    Many of us are faced with the question of whether to crown or not to crown endodontically treated teeth. Any guidlines or criteria available in literature?

    Niek J M Opdam

    I always tell my students:' more dentistry more trouble'. Or another one: 'look on the panoramic radiograph which tooth in the mouth of the patient has the worst prognosis: it is often the most expensively treated tooth with a crown....'.

    In other words: try to avoid overtreatment, think minimally invasive and base your decission on individual risk assessment. What do we know?

    - Endodontically treated teeth have a higher risk for unfavourable fracture

    - More tooth reduction leads to higher risk for tooth loss and restoration failure

    - Bruxism, caries risk have a higher impact on restoration longevity then materials.

    So if a first molar has an mod restoration and much tissue left buccaly and lingually, I would preferably make a minimal invasive restoration. If the tooth is heavily loaded (bruxism?) make a cusp capping restoration, If your good in direct techniques, make it direct, if you're good in indirect techniques, do it indirect (combined with Deep Margin elevation?). In a high caries risk situation, go for minimally invasive solutions, more direct restorations are probably more favourable. If the endodontic treatment is done on a crowned tooth, go for a new crown (when the old crown has failed, otherwise, go for a repair).

    One cannot say which solution is the best, it's all dependant from risk assessment, the wishes of the patient, and trying to be as minimally invasive as possible. And of course which skills you have as a dentist.

  • Ahilan Anantha Krishnan asked a question in Roughness:
    To what extent really the emmisivity changes with changes in surface roughness ?

    For example, I have a thick sheet of teflon for which emissivity to be checked. It is worn out at some abrasive environment, leading to surface roughness in microscopic scale. How the emissivity of the surface compare before and after it was worn out ?

  • Ane Ripoll-Zarraga added an answer in Corporate Social Responsibility:
    Is there such a thing as a business case for corporate social responsibility?

    It’s not just about getting better at what we do – addressing impacts throughout our supply chain – it’s about striving for the best, creating value for the business and innovating for a better world (A Definition of CSR by Nike in Andrew Crane, Dirk Matten and Laura J. Spence, 2014 - CSR Readings & Cases)


    • Source
      [Show abstract] [Hide abstract]
      ABSTRACT: Corporate social responsibility (CSR) policies can be re-conceived strategically to confer competitive advantage as implied by the proponents of the ‘shared value’ notion. A qualitative research involved in-depth, semi structured interview questions that explored eco-certified accommodation establishments’ ethos for responsible behaviors. The findings have indicated that discretionary spending in socially and environmentally-sound initiatives have led to improved stakeholder relationships, effective human resources management, better market standing, operational efficiencies and cost savings, along with other benefits.
      American Marketing Association: Marketing and Public Policy Conference, Washington DC; 06/2015
    Ane Ripoll-Zarraga

    I do not think so. The main reason is because there is not regulatory framework behind CSR (this is as not being compulsory for companies). Also, there is a divergence between SMEs and Big companies in terms of resources (human factors and timing as well as financial resources). Consequently, I do not think that we could extrapolate from one case study to build up conclusions.

    I am adding the same answer I provided to another colleague about CSR from a critical perspective:

    Since CSR is not a standard (as defined by IFRS; IASs and ISAs), the fact that a company does not publish disclosures regarding CSR does not necessarily imply that there is not fully or partially CSR considered (for example in terms of social  or economical aspects). CSR disclosures are voluntarly for entrpreises in Europe and are cost and time consuming. SMEs may apply for example an environmental aspect since SMEs tend not to have enough resources (human factor or economical-timing) to write further notes. 

    CSR are normally published by big companies because they have resources to do so, but again some information may not be disclosure deep enough.

    I would also highlight another aspect of CSR commonly forgotten (it may potentially recent) that it is the institutional one. This is specific regulatory framework applied to some companies due to be performing in very specialised sectors that may be regulated (energy) or sectors that affect the social welfare in specific countries (connectivity in terms of airports such as in Norway, etc.) that may imply tailored standards or sections of them and it is essential to reflect this as part of CSR.  

    I wish this helps, Ane

  • Robert Ose added an answer in Fluorescence:
    Is there any membrane-impermeable cell tracker (tracer) which shows fluorescence only inside the cell?

    I'm searching for a cell tracker/tracer which is non-fluorescent outside the cell and cannot cross cell membranes freely. Once the dye is brought inside the cell it should remain there and gain fluorescence.

    Has anyone worked with something like that?

    Thanks in advance

    Robert Ose

    Thanks again,

    According to the description i cannot use it because it crosses the membrane freely (prior to the esterase cleavage).

  • Parida Aditya added an answer in Organization:
    What is the best way for assessment of management support in success of an organization?

    What is the best way for assessment of management support in success of an organization?

    Parida Aditya

    To summarize in two words:  "Follow ISO55000",

  • Hamed Abbasi added an answer in Light Science:
    How can I calculate x and y coordinate of any color in CIE 1931 color space chromaticity diagram?

    I want to calculate x and y coordinate of a given color in CIE 1931 color space. What is the practical formula for that? I am attaching herewith the information I got from internet

    In order to calculate x, y coordinates we need to calculate X,Y and Z which is called the tristimulus values of a color.

    Hamed Abbasi

    You can find different matrixes to convert XYZ to RGB as well as RGB to XYZ based on various standards (Adobe RGB, Apple RGB, CIE RGB, ...) here:


  • Béatrice Marianne Ewalds-Kvist added an answer in Sexual Abuse:
    Can anyone recommend a questionnaire on sexual abuse and resilience?

    can anyone suggest a questionnaire on sexual abuse in childhood  and resilience?

    Béatrice Marianne Ewalds-Kvist

    Dear Vineeta, 

    Check these papers out if they are of use for you:

    • Source
      [Show abstract] [Hide abstract]
      ABSTRACT: To evaluate the psychometric properties of a new measure, the Abuse-Related Beliefs Questionnaire (ARBQ), designed to assess abuse-related beliefs among adult survivors of childhood sexual abuse (CSA). Study 1 examined the structure of the scale, and Study 2 evaluated its reliability and validity. One hundred and seventy female CSA survivors recruited into a group psychotherapy intervention study were administered the ARBQ in Study 1. A subsample of 45 women completed the ARBQ again 12 months later. In Study 2, 70 women from a health maintenance organization who identified themselves as survivors of CSA completed the ARBQ along with the Trauma Symptom Checklist-40 (TSC-40) and the Symptom Checklist 90R (SCL-90-R). Three reliable ARBQ subscales emerged in Study 1: Guilt, Shame, and Resilience. Twelve-month test-retest reliability was high (r=.60-.64). The internal consistency of the subscales was further supported in Study 2, and validity was demonstrated by moderate to high correlations with the distress measures. The results indicate that the ARBQ has good psychometric characteristics, supporting the feasibility of its use in measuring abuse-related beliefs in research on survivors of CSA. A next step for validation of the ARBQ would be to evaluate its sensitivity in measuring changes in studies of interventions for treating CSA survivors.
      Child Abuse & Neglect 09/2006; 30(8):929-43. DOI:10.1016/j.chiabu.2006.01.004

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  • Jai Ghosh added an answer in Curcumin:
    If curcuminoid or curcumin is oxidized, does it produce benzo-quinone?

    As far as I know, hydro-quinones and benzo-quinones have at least two hydroxyl groups and oxygens, respectively,  bonded to one phenolic ring.

    But the structure of curcumin or curcuminoid have only one hydroxyl group to each phenolic ring. So I'm guessing oxidation of curcumin doesn't produce quinones. But can't be sure...  Does anyone help..?

    Jai Ghosh

    I think what Rafik has replied is pretty precise. Now it is upto you to find out whether benzoquinone is finally produced or not.

  • Kai Tian added an answer in CPR:
    Why cannot my bicistron express?

    hello, I built a Bicistronic P450 and CPR plasmid in pcw vector. It could not work well while the gene be constructed in pcw can express well respectively. I notice that the second gene can express in this bicistron. Does it mean that the first gene has expressed, but without activity?(I didnot do an SDS-PAGE)

    Another question: Does the length of link sequences between two genes will affect the first gene‘s expression? 


    bolds are stop codon and start codon; italics are RBS.

    Kai Tian

    Thanks for Kevin and Jolanta. I will run a SDS-PAGE.

  • Christian Punckt added an answer in Metal Oxides:
    Can I get exact weight percentage of any metal from EDS analysis for a catalyst sample?

    If the catalyst contains different metal oxide. Then is it possible to know exact weight percentage of the metals? If not, then what is the exact technique to know that percentage?

  • Parthasarathy Iyengar added an answer in Sequence Analysis:
    Can someone help in the DNA sequencing technique and recommend a book and a program for the sequence analysis?

    Plz i want some help in the DNA sequencing technique, so any recommendation for a book and a programe for the sequence analysis???

    Parthasarathy Iyengar
    1. The knowledge on biochemistry on DNA and genes is most essential for DNA analysis
    2. it comprises of finding a gene
    3. it states about the comparison of that gene or genome with other gene or genome or protein etc.
    4. books like Author wood curren etc will guide you much on this topic
  • Jeffrey J Weimer added an answer in Langmuir:
    What is the negative value obtained in Langmuir Isotherm Model? Is there any specific range for b constant so that the value is logical?

    Hi. I have random questions regarding Langmuir Isotherm Model.

    1) What does it means if I have negative intercept value for Langmuir Equation in the graph of:

    Ce/qe = 1/Q (Ce) + 1/Qb

    2) How do I know whether the obtained value of  b constant is logical or not?

    Jeffrey J Weimer

    To be blunt, I would answer this new report in the same way as before.

    Have you repeated the experiment at least three times to confirm that you get what seems to be the same raw data? Have you considered other models to fit your data? Have you done non-linear regression analysis on all experiments to get fitting values and their standard uncertainties? Have you propagated the uncertainties in fitting values and the experiment uncertainties to know the true confidence in your work?

    With so many options for interpretation, no one can tell you what your results really mean. We can however tell you what you need to do to figure it out yourself.

  • Ana Donevska-Todorova asked a question in Mathematics Education:
    How Much Mathematics is There in Early Mathematics Education?

    I would like to hear your opinion about the current state of how much mathematics is there really in the mathematics education in primary schools today.

  • Helen Gough added an answer in Narrative Inquiry:
    Narrative inquiry: can anyone direct me to an example of a narrative interview guide?

    I have developed a narrative interview guide drawing on Clandinin et al's  (2007) three commonplaces but it would be useful to see other examples.  Plus in narrative inquiry does anyone have a link to literature about giving the interview schedule to the participant prior to interview?  I thought I would but have no evidence to support this. helen

    Helen Gough

    Dear Lynn

    many thanks for this generous reply and I very much appreciate the information and expertise. Thank you I have the text that you highlight and will re visit Andrews stories. In a previous study I used collaborative action research study and I was aware that when I met a group of experienced nurses that before we could begin our work on developing the study it was important for them as a group to share stories about various experiences. I always timetabled time for this over our next few meetings. On reflection this was not a new phenomenon as I began to recognise storytelling among my lecturer colleagues too. This seemed to be a way that nurse teachers shared meaningful experiences and I was very much part of this storytelling activity myself. I had already gathered some narratives from the older generation in my family and the power of the story and its content became more meaningful as I began to plan the empirical element of my Prof Doc programme. My study focuses on the career and educatonal experiences of nurse teachers and when I discovered the work of Clandinin and Connelly (via Dewey) the approach resonated with me strongly and led me to investigate this mehodogy more closely.  I have developed two interview questions to initiate stories with participants and have included some follow up questions when the story comes to a natural end 

    ·        what were your hopes, desires, feelings (temporality)

    ·        who were the people, factors  involved    (sociality)

    ·        can you tell me about the environment/location where this took place   (place)

    I will not know the potential participants (three from across the UK hopefully) and I thought that once they have contacted me and we arranged date for interview I could forward the questions as a way of initiating a relationship by being transparent in my approach. Hence my original question, but I could not find any evidence for doing this. I hope to meet Jean Clandinin in Glasgow next year at the qualitative methods conference and I have submited an abstract for this.  An opportunity to travel to Alberta and participate on a course on narrative inquiry would be fantastic but unfortunately not likely for a number of reasons. Great you may visit Ireland next year and a catch up may be possible depending on location in Ireland and dates and times. Once again thank you for such an encouraing reply Lynn. Best wishes helen

  • David Jule Mack added an answer in Image Enhancement:
    How to generate Gaussian noise with certain variance in MATlab?
    Can anyone explain how to generate Gaussian noise, speckle and impulse noise at different variances and standard deviation values? Please help me.
    David Jule Mack

    Dear Isreal,

    SD    = sqrt(1/n*sum((X-XMean)^2)); %Biased estimator.
    RMS = sqrt(1/n*sum(X^2));

    SD = RMS for XMean = 0 (which is the case for white Gaussian noise),

    I don't think you need a reference for that. Hope that answers the question.

    Greetings, David

  • Hany Mohamed asked a question in Arabic Language:
    Did anyone works with word-net affect or its related?


    please i need your help in working with such database and how it handles with Arabic language, also how to implement it using any of software language?


  • Jai Ghosh added an answer in Antibacterial Activity:
    Has anyone applied SPSS tests to their antioxidant & antibacterial activity of compounds or extracts?

    Has anyone applied SPSS tests to their antioxidant & antibacterial activity of compounds or extracts?

    Jai Ghosh

    I agree with both Joao and Abdelrahim.

  • Kenan Lopcu added an answer in Panel Data:
    Is it necessary to run stationary (panel unit root) test for panel data?

    Is it necessary to run stationary (panel unit root) test for panel data? When the T =30years and N =15.

    Kenan Lopcu

    Check the following papers. The first one does not deal with cross sectional dependence. For a review and application look at the last article. You can find it in the internet /researchgate readly. Good luck.

    Im, K., Pesaran, H., and Y. Shin, (2003), “Testing for Unit Roots in Heterogeneous Panels,” Journal of Econometrics, 115, 53-74.

    Pesaran, M. Hashem (2004) “General Diagnostic Tests for Cross Section Dependence in Panels” Cambridge Working Papers in Economics, No. 435, University of Cambridge, and CESifo Working Paper Series No. 1229.

    Pesaran, M. Hashem (2007) “A Simple Panel Unit Root Test In The Presence Of CrossSection Dependence” Journal of Applied Econometrics, Vol.22, 265-312.

    Lopcu, K., & Ateş, S. (2009). Income Convergence between Turkey and EU Regions: A Panel Unit Root Approach. In Anadolu International Conference in Economics.

  • Mohamed El Naschie added an answer in Boundary Condition:
    Any guidance on the procedure to get the natural frequency of a plate with general boundary condition?

    Pse guide on the proceedure to get the natural frequency of a plate with general boundary condition?

    Mohamed El Naschie

    what is the shape of the plate and how general the boundry condition?  other wise the problem is rather siple and classical eigenvalue in structural mechanics

  • Hugh Lachlan Kennedy added an answer in Acceleration:
    What does FFT transform affect on the acceleration unit? Is it m/s2 in frequency domain?

    I have a signal in time domain, actually, acceleration was calculated in time domain and the acceleration changes between [-4,4] m/s2. Then I did an FFT on the signal and converted to frequency domain; but the amplitude of acceleration in frequency domain is between [10e-4,1]. Why this difference? Is acceleration normalized during the FFT transform or not?

    What will be the difference between unit of both the domain?

    Hugh Lachlan Kennedy

    I don't know how you would interpret the spectrum of acceleration data. Why not stay in the time domain? What was your motivation for frequency-domain analysis?

  • Abu-Hussein Muhamad asked a question in Chromosome 22:
    Dental Mangement in The 22q11.2 Deletion Syndrome?

    A 22q11.2 distal deletion is a rare genetic condition caused by a tiny missing part of one of the body’s 46 chromosomes – chromosome 22.

    What is Dental  Mangement in The 22q11.2 Deletion Syndrome?

  • Hany Mohamed asked a question in Sentiment Analysis:
    Are you interested to joint research?

    Dears, if anyone interested in sentiment analysis or emotion mining research, and willing to do joint research, kindly contact me by inbox Thank you

  • Emrah Dolgunsoz added an answer in Eye Tracking:
    Can anyone suggest any Eye Tracking device (with weblink) for conducting cognitive experiment?

    I am looking for an Eye Tracking device to conduct cognitive experiments. Easy to understand the interpretation language is the first prerequisite. It would be a nice help if some one can send me any web link with price and shipment procedure. I would like to buy this device for my Dhaka University Memory Research Unit (DUMRU), Dhaka, Bangladesh. 

    Emrah Dolgunsoz

    To spot the best device suitable for your experimental purposes, you may specify more features such as sampling rate and analysis qualiy. For low cost devices, "gazepoint eye tracker" works well. Tobii and SMI are high end brands with a relatively higher cost and more preferences regarding technical features. Good luck.

  • Sofia Moura asked a question in Business Plans:
    How do I extract DNA from Human Placenta for analysis of PMS2 gene?

    I have never worked with human placenta before and now as my final year dissertation that is that type of sample that is going to be provided. I also have to do a business plan but I cannot find anywhere how much would cost me to get a sample of human placenta. Any help? Also what are the best kits ?


  • Kaleem Ullah asked a question in Books:
    Evanescent Waves From Newtonian Optics to Atomic Optics??

    Hi everyone you know there is less literature about the Evanescent field i have found a very good book which is written by F.de Fornel the link is as attached but unfortunately i and my friends have no access to that book and also i have requested author to give me book through Research Gate but she did not give me feed back so please send me this book if you have access i shall be very thankful to you for this.

  • Béatrice Marianne Ewalds-Kvist added an answer in Cognitive Neuroscience:
    Are there any publications mentioning formant transition durations between VV (vowel-vowel) and CV (consonant-vowel) syllables?

    Does anybody know what the average duration of a vowel to vowel formant transition is compared to a consonant to vowel transition?

    Béatrice Marianne Ewalds-Kvist

    Dear Paul, 

    Check the references to these papers out if there is something useful for you: 

    • [Show abstract] [Hide abstract]
      ABSTRACT: The purpose of this study was to assess the perceptual role of brief synthetic consonant-vowel syllables as cues for vowel perception in children and adults. Nine types of consonant-vowel syllables comprised of the stops [b d g] followed by the vowels [i a u] were synthesized. Stimuli were generated with durations of 10, 30, or 46 ms, and with or without formant transition motion. Eight children at each of five age levels (5, 6, 7, 9, and 11 years) and a control group of eight adults were trained to identify each vowel in a three-alternative forced-choice (3AFC) paradigm. The results showed that children and adults extracted vowel information at a generally high level from stimuli as brief as 10 ms. For many stimuli, there was little or no difference between the performance of children and adults. However, developmental effects were observed. First, the accuracy of vowel perception was more influenced by the consonant context for children than for adults. Whereas perception was similar across age levels for stimuli in the alveolar context, the youngest children perceived vowels in the labial and velar contexts at significantly lower levels than adults. Second, children were more affected by variations in stimulus duration than were adults. This finding was particularly prominent for the syllable [ga], where the dependency on duration decreased with age in a nearly linear fashion. These findings are discussed in relation to current hypotheses of vowel perception in adults, and hypotheses of speech perception development.
      The Journal of the Acoustical Society of America 01/1997; 100(6):3813-24. DOI:10.1121/1.417338

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