Q&A

ResearchGate Q&A lets scientists and researchers exchange questions and answers relating to their research expertise, including areas such as techniques and methodologies.

Browse by research topic to find out what others in your field are discussing.

Browse Topics

A B C D E F G H I J K L M N O P Q R S T U V W X Y Z
  • Can you describe, analogously, the purpose of a nested k-folds method.

    I understand how/why one goes about breaking data up into a train/test/cross validation set; however, it is unclear how this works analogously when the more rigorous nested k-folds method.  Additionally, can you describe the motivational difference between a k-folds method and a nested k-folds method.  The link below provides mathematical details for the nested k-folds method.

    Dr. Indrajit Mandal · SASTRA University

    dear friend

    The aim of these kind of Cross validation is to

    1. see that the train set and the test set are independent. 

    2. To evaluate the average performance of the classifiers.

    3. To see how the algorithm will behave given another dataset is given....

    Nested CV is done for more rigorous testing and training.

    You just see my publications , you will find more details....

    Mandal, I., Sairam, N. New machine-learning algorithms for prediction of Parkinson's disease (2014) International Journal of Systems Science, 45 (3), pp. 647-666. DOI: 10.1080/00207721.2012.724114

    Mandal, I., Sairam, N. Accurate telemonitoring of Parkinson's disease diagnosis using robust inference system (2013) International Journal of Medical Informatics, 82 (5), pp. 359-377. DOI: 10.1016/j.ijmedinf.2012.10.006

    Mandal, I., Sairam, N. Accurate prediction of coronary artery disease using reliable diagnosis system (2012) Journal of Medical Systems, 36 (5), pp. 3353-3373. DOI: 10.1007/s10916-012-9828-0

    Mandal, I., Sairam, N. Enhanced classification performance using computational intelligence (2011) Communications in Computer and Information Science, 204 CCIS, pp. 384-391. DOI: 10.1007/978-3-642-24043-0_39

    Mandal, I. Software reliability assessment using artificial neural network (2010) ICWET 2010 - International Conference and Workshop on Emerging Trends in Technology 2010, Conference Proceedings, pp. 698-699. DOI: 10.1145/1741906.1742067

    Mandal, I. A low-power content-addressable memory (CAM) using pipelined search scheme (2010) ICWET 2010 - International Conference and Workshop on Emerging Trends in Technology 2010, Conference Proceedings, pp. 853-858. DOI: 10.1145/1741906.1742103


    Indrajit Mandal, Developing New Machine Learning Ensembles for Quality Spine Diagnosis, Knowledge-Based Systems, Available online 19 October 2014, ISSN 0950-7051, http://dx.doi.org/10.1016/j.knosys.2014.10.012.
    http://www.sciencedirect.com/science/article/pii/S0950705114003797

    Mandal, I. A novel approach for accurate identification of splice junctions based on hybrid algorithms (2014) Journal of Biomolecular Structure and Dynamics
    pp. 1-10 | DOI: 10.1080/07391102.2014.944218 PMID: 25203504
    http://bit.ly/1vQZsei

    Thanks a lot. 

    I hope this will help you.

    Best,

    Dr.Indrajit Mandal

  • What are appropriate scavengers in the t-butyl group deprotection in peptide synthesis?

    I have a peptide of 31 amino acid chain length, consisting of amino acids like histidine, arginine, tryptophan. I have to remove the t-butyl group from the alpha carboxyl of glutamic acid. I am looking for the suggestions regarding the scavenger combinations required in this TFA mediated cleavage step. 

    Pratap Subhashrao Patil · Saviorlifetec Corporation, Zhunan, Taiwan

    Dear Ruben Leenders,

    Thiol specially EDT in combination with thioanisol and phenol is the best option (from my search). However, in industry not many people prefer to use thiol....So I am keeping this as a last option.. 

  • Can you suggest a scale for measuring effects of microfinance on entrepreneurial intention?

    I am doing research in entrepreneurial intention. I want to measure the effects of microfinancing on the intention of becoming an entrepreneur. Please suggest a relevant scale to measure effectiveness of microfinance.

    Upananda Witta Arachchilage · Wayamba University of Sri lanka

    Dear Shoaib Farooq,

    Thanks for your prompt acknowledgement.!

    Upananda (Sri Lanka)

  • How do I determine the optimal partial ratios of a three (or multi stage) stage gearbox?

    I have a 3 stage gearbox of which I am trying to optimize the total volume. Is there any way to find the optimal partial ratios of the 1st, 2nd and 3rd stages, if suppose I know the total gear ratio of the entire gearbox (say in my case the total reduction ratio is 15). 

    Maddali V S Murali Krishna · Chaitanya Bharathi Institute of Technology

    Please follow this paper where detailed prodedure is given for calucating partial gear ratio-Optimal Calculation of Partial Transmission Ratios of Four-Step Helical Gearboxes for Getting Minimal Gearbox Length,

    World Academy of Science, Engineering and Technology,  Vol:2 2008-01-23 

  • Ji Ryong Cho added an answer in Hydrodynamics:
    What is the difference between hydrodynamic cavitation and flash boiling?

    I can't figure out the difference between cavitation and flash boiling in the field of spray atomization? Both of them generate bubbles, does these bubbles have the same content? 

    Ji Ryong Cho · Inje University

    Hello!

    One big difference is the form of energy contained inside the bubble. Cavitation bubble is dominated by the pressure energy while boiling bubble is dominated by the thermal (temperature) energy.

  • Hai-Yao Deng added an answer in Glass Transition:
    What's the viscosity of PMMA at glass transition temperature?

    Polymer viscosity reduces when temperature is at or above glass transition temperature. PMMA is very widely used polymer. 

    Hai-Yao Deng · National Institute for Materials Science

    Technically, the viscosity of any glass formers at the transition temperature is defined to be ~ 10^12 Pas. 

  • Gedda Gangaraju asked a question in Calibration curve:
    What is the meaning of y-intercept standard deviation and how to calculate ?

    (LOD=3sy/b (being sy the y-intercept standard deviation and b the slope of the calibration curve)) Can any explain here in this formal (1)details about y-intercept standard deviation my question is that what is the meaning of y-intercept standard deviation and how to calculate ?

  • What will be the probable effect of water and sediment pollution on mangroves?

    Due to rapid pace of industrialization and urbanization, the estuarine water and sediment are getting polluted day by day. As a result, the pollutants are also getting accumulated into the tissues of mangroves. In this scenario, what will be the fate of mangroves in the future? Will they be able to withstand the adverse effect of pollution?

    John W Farrington · Woods Hole Oceanographic Institution

    I am late to this discussion because of other responsibilities. I did wish to point out the following references to add for oil pollution in mangroves.  They note the multi-year fate and effects of spilled oil in this mangrove ecosystem. Best wishes, John


    J. B. C. Jackson, J. D. Cubit, B. D. Keller, V. Batista,
    K. Burns, H. M. Caffey, R. L. Caldwell, S. D. Garrity, C.
    D. Getter, C. Gonzalez, H. M. Guzman, K. W. Kaufmann,
    A. H. Kanp, S. C. Levings, M. J. Marshall, R. Steger, R. C.
    Thompson, and E. Weil, “Ecological Effects of a Major
    Oil Spill on Panamanian Coastal Marine Communities,”
    Science 243 (1989): 37–44.

     S. D. Garrity, S. C. Levings, and K. A. Burns, “The
    Galeta Oil Spill. I. Long Term Effects on the Physical
    Structure of the Mangrove Fringe,” Estuarine, Coastal and
    Shelf Science 38 (1994): 327–48.

    K. A. Burns, S. D. Garrity, D. Jorissen, J.
    MacPherson, M. Stoelting, J. Tierney, and L. Yelle-
    Simmons, “The Gaketa Oil Spill. II. Unexpected
    Persistence of Oil Trapped in Mangrove Sediments,”
    Estuarine, Coastal and Shelf Science 38 (1994): 349–64;

    S.C. Levings, S. D. Garrity, and K. A. Burns, “The Galeta
    Oil Spill. III. Chronic Reoiling, Log-Term Toxicity of
    Hydrocarbon Residues and Effects on Epibiota in the
    Mangrove Fringe,” Estuarine, Coastal and Shelf Science 38
    (1994): 365–95;

    K. A. Burns, and L. Yelle-Simmons, “The

    Galeta Oil Spill. IV. Relationship Between Sediment and
    Organism Hydrocarbon Loads,” Estuarine, Coastal and
    Shelf Science 38 (1994): 397–412.

    K. A. Burns, S. D. Garrity, and C. Levins. “How
    Many Years Until Mangrove Ecosystems Recover From
    Catastrophic Oil Spills?,” Marine Pollution Bulletin 26
    (1993): 239–45.

  • Indrikis Krams asked a question in Insect:
    I need to detect the total amount of carbon (C) and nitrogen (N) in insects and plants. Does anyone know methods to do this?

    Carbon : Nitrogen ratio is sensitive to stress, and it is also well known that any change of soil pH may cause changes in the content of C and N in plants.

  • Carlos Araújo Queiroz added an answer in Silver:
    How to influence Oxygen solubility in Silver melt?

    I'm looking for data about Oxygen solubility in Silver above melting temperature and influence of alloying elements.

    Is any element helping to decrease Oxygen solubility in a Silver melt?

    Carlos Araújo Queiroz · New University of Lisbon

    You may find worthy to check another thread which discusses the possible interdependent effect of other gases at the solubility of a particular gas in a melt:

    https://www.researchgate.net/post/If_the_pressure_of_a_gas_is_the_only_factor_that_determines_the_amount_of_dissolution_of_it_in_melt_why_the_other_gases_dont_affect_it

  • Amin Fatoni asked a question in Peroxidases:
    Are there any chemical to colorimetrically detect hydrogen peroxide without enzyme (peroxidase)?

    I am looking for some chemical / dye / reagent that can react directly with hydrogen peroxide to produce color, for simple colorimetric detection. Mostly, hydrogen colorimetric assay involved peroxidase enzyme. I am looking for the hydrogen peroxide reaction to produce color without peroxidase enzyme
    Thank you

  • Erik Walinda added an answer in Zinc Sulfate:
    Is anyone familiar with Zinc addition to E. coli growth medium?

    I am facing serious trouble with expression of a zinc-binding protein in M9 labeled media. The protein is a GST-fusion protein and is said to bind to zinc ions. It expresses extremely well in LB medium (several tens of miligrams per liter of culture), but does not express at all in M9 medium (and also in CIL medium "Spectra 9"). Of course everyone I ask tells me that this is strange and something is seriously wrong.

    Indeed the cells grow well in M9, so I asume this is purely an expression problem. When I run the E. coli cell extract on a gel, I see a sharp band for where GST would migrate and only a faint band where I would expect my target protein.

    Therefore, I am currently assuming that transcription is correctly initiated by IPTG, however the protein does not fold correctly and is thus degraded in the bacterial cell and only the soluble GST tag remains. Misfolding could occur if the cells cannot access zinc (which would be available in LB in traces, but not in M9 if my zinc administration is wrong). Therefore, I would like to ask for the correct method of addition of zinc to a culture of M9 minimal media.

    I tried the following variety of conditions without success for expression in M9:

    E. coli: BL21(de3) / C41(de3) / C43(de3)
    IPTG 0.1 - 1 mM
    Temperature: 16 - 22 C
    OD600 at induction: 0.5-0.8

    Zinc administration: stock solution (50 mM zinc sulfate) is added to the culture flask 30 minutes prior to induction with IPTG (final concentration of zinc sulfate: 0.2 mM).


    I also tried Marley's method (grow the cells in LB first and exchange the medium to M9) which also resulted in no protein yield at all.

    Desperately hoping for a bit of advice,

    Sincerely,

    Erik

    Erik Walinda · Kyoto University

    Dear Woonghee Lee,

    Thank you very much for your answer.

    I checked the methods section in your link.

    Preparation of Uniformly 15N and 13C/15N-Labeled Protein on a Large-Scale

    I have two questions.

    • Does your metal mix contain EDTA?
    • If it does not, does your zinc chloride precipitate upon addition to M9 media? (In my case zinc phosphate is readily formed and I get white precipitates upon zinc addition into M9)
  • Tylor Burrows added an answer in Lectures:
    How can I help my intro psych students improve their test scores?

    I am currently teaching introductory psychology using "Psychology: From Inquiry to Understanding" by Lilienfeld, Lynn, Namy, and Woolf. It's a lecture format class, but exams are taken using MyPsychLab and the questions come from MyPsychLab's test bank. The scores from the first exam were well below what I would have liked to see. Has anyone had the experience of trying to improve test scores after a disappointing first exam? What techniques did you use? How do you keep students motivated after a rough first outing?

    Tylor Burrows · University of Ottawa

    Interesting question.  

    For improving test scores, one approach would be to look at the kinds of questions that are being asked, particularly the knowledge/skills that students need to answer.  If you know the expected learning outcomes/objectives which are being assessed by MyPsychLab's test bank, then you have an idea of where you are trying to go with your students.  Some people might consider this teaching to the test, but if the test is well constructed -and your goal is to increase their scores as a reflection of their learning- I have no problem with that.  At this point you will know what you are trying to teach them (based on the book and MyPsychLab) and how students' understanding will be assessed (based on MyPsychLab).

    The next thing to do is look at the teaching/learning activities that are meant to help students meet the intended learning objective.  If you are assigning readings and then giving a lecture -which is common- and the students don't seem to be learning,  perhaps something more or different is required.  This is probably the main question you are asking.  The short answer is that students should be actively engaged in the materials; reading and listening are essentially passive activities and unless students are prompted they may not stop to understand or apply what they are receiving.

    Exactly what active learning techniques you could try depends on yourself, your students, and your content.  I like making jigsaw puzzles when the material fits, and discussion activities like think-share-pair are a good standby.  If you are technically savvy students could tweet answers to your questions or you could create online polling questions to liven up the class.  With smaller groups of students you could assign seminar periods where the students teach each other.  Psychology isn't my field, but there is lots of research to support the rather broad suggestion above.  I quickly dug up a few links for you to consider:

    Your university has a teaching and learning centre with people who will probably sit down with you (and the textbook and syllabus) and can make concrete suggestions on active learning strategies: http://www.utoledo.edu/campus/centers/index.html

    There is a good primer for active learning at: http://www.crlt.umich.edu/tstrategies/tsal.  

    Topical teaching ideas and resources are available here: http://topix.teachpsych.org/w/page/19980993/FrontPage

    I highly recommend this book if you can get access to it: http://www.amazon.com/Teaching-Learning-University-Research-Education/dp/0335242758

    There is also a scholarship of teaching and learning for psychology that might want to become familiar with.  A good journal to start with would probably be: http://www.apa.org/pubs/journals/stl/

    * A final note --> don't forget to take a few minutes after a lecture to REFLECT AND RECORD what went well with the lesson and what didn't.  Sometimes new ideas don't work and need adjustment, but learning how you want to teach your subject is a process which should be ongoing as you and your audience change over time :)

  • How do I convert kinetic energy of electrons to temperature?

    In thermionic emission, electrons are produced by applying output voltage and filament current. From that we can calculate kinetic energy of electrons. What will be the temperature of the incident beam that are produced. How do I convert the kinetic energy of the beam to temperature. 

    If I know the temperature could I correlate the ingot temperature by hitting the electron beam in EB-PVD system.

    Maddali V S Murali Krishna · Chaitanya Bharathi Institute of Technology

    Kinetic theory tprovides a microscopic explanation of temperature, based on macroscopic systems' being composed of many microscopic particles, such as molecules and ions of various species, the particles of a species being all alike. It explains macroscopic phenomena through the classical mechanics of the microscopic particles. The equipartition theorem of kinetic theory asserts that each classical degree of freedom of a freely moving particle has an average kinetic energy of kBT/2 where kB denotes Boltzmann's constant. The translational motion of the particle has three degrees of freedom, so that, except at very low temperatures where quantum effects predominate, the average translational kinetic energy of a freely moving particle in a system with temperature T will be 3kBT/2.

  • Bhoj R Singh added an answer in A549 Cells:
    What is the concentration of the gentamicin to kill the extra-cellular bacteria during infecting the cells by the Kleibsella pneumoniae?

    I am trying to infect a A549 cell line by Kleibsella pneumoniae. But after 6-8 hrs of infection I observed the high presence of extra-cellular bacteria despite treating earlier with 200ug/ml of gentamicin. I am wondering, what concentration should I use?

    Bhoj R Singh · Indian Veterinary Research Institute

    It all depend on the MBC of gentamicin for your strain, you should conduct a time kill experiment for your strain and select the appropriate concentration, that concentration should also be checked  for toxicity on cells you are using. 

  • Goutam Brahmachari asked a question in HTTP:
    Are you interested to take part in the upcoming HOT Issue of Current Organocatalysis, being guest edited by me?

    Esteemed Colleagues:

    You are welcome to contribute to the HOT issue of Current Organocatalysis being guest edited by me. Please visit the following links for more information.

    http://benthamscience.com/journal/special-issues.php?journalID=cocat

    http://benthamscience.com/journal-files/special-issue-details/COCAT-SII20141022-01.pdf

    You can feel free to inquire at me via brahmg2001@yahoo.co.in / brahmg2001@gmail.com

    Looking forward to your participation! Goutam Brahmachari

  • Martin Balog added an answer in Bruker:
    Is there someone with access to a Bruker OHN Galileo analyzer?

    I am in need of reproducible oxygen measurement in UFG Al produced by compaction of fine gas atomized CP Al powders. Oxygen is present in a form of native nano scale Al2O3 phase introduced in situ (expected content ~ 0.5-2 wt% O). Thanks in advance.

    Martin Balog · Slovak Academy of Sciences

    Hi Cecilia, thanks for reply. Is that a machine you meant which is in Dr. Christian EDTMAIER group? I have pursued this option year ago with no success. To our experience Leco OHN is inferior compare to Bruker OHN in terms of Al based materials (and it is the other way around for the case of Ti). BTW we have got brand new Leco OHN at IMMM.

  • Barbara Goodrich added an answer in Qualia:
    What role has anticipation in consciousness?

    Philosophers says the brain is an anticipation machine. I miss this statement in the present discussions of consciousness on RG. Is there any interrelation of consciousness, Qualia and anticipation?

    Barbara Goodrich · University of Colorado

    Second comment, a recommendation: From the humanities (music) perspective, David Huron's 2007 book Sweet Anticipation: Music and the Psychology of Expectation fleshes out much of the phenomenology of anticipation in useful ways.  It still might be useful to scientists even now, and I suspect it didn't get much coverage outside the music world, sadly.   

  • Bhoj R Singh added an answer in Reproductive Health:
    Do probiotics improve your reproductive health and reduce your age of puberty?

    Our observations on mice and poultry birds reveals that Axone (fermented soybean) reduces age of sexual maturity, increases reproductive efficiency and harmonize humoral immunity.

    Bhoj R Singh · Indian Veterinary Research Institute

    Thank You Marie for the reply, I also think it might be soybean phytoestrogen, but I have one suspision either these molecules are stable at boiling for 90 min or not. It is the important and very first step in preparation of Axone.

  • What do you think of gender in institutional leadership and security forces?
    I am doing a paper discussing the sexual assaults that have occurred on university grounds. It has been suggested that I also look at the decisions makers in relation to the implementation of policy and follow-up investigations to such events. As far as I can see many of these decision are made by men, and the majority of the security force staff are a ratio of 8:1 (or higher). When I look at research papers discussing security process they appear to be all written by men, and yet the papers discussing sexual assaults are written by women.
    Zana Jano · Technical University of Malaysia Malacca

    Your study is very interesting. When you get to the findings then try to see whether biases exist.

  • Does anyone know this kind of great tit vocalization? May be a contact call?

    I’m recording great tit vocalizations around the nest during breeding. Males can use songs, alarm calls or this kind of call that I am not sure to identify (see the attached files).

    Indrikis Krams · University of Tennessee

    This sounds like a long-range communication call. These are often used while moving fast in the  dense canopy, and when pair or flock members are separated by the distance of 10-15 m at least. 

  • What is the best way to manage keratocystic odontogenic tumours encroaching the maxillary sinus?

    Invasion of skull base will be difficult to manage.

    Lakshmanan Suresh · University at Buffalo, The State University of New York

    Hi,

    In my experience and in literature review, the treatment of choice would be weber – ferguson approach and  enucleation with  peripheral ostectomy with the use of Carnoy's solution and excision of the overlying attached mucosa where needed.  Please see below some reference that may be useful.

    Thank you

    Lakshmanan Suresh

    Selected References:

    Blanas N1, Freund B, Schwartz M, Furst IM. Systematic review of the treatment and prognosis of the odontogenic keratocyst.Oral Surg Oral Med Oral Pathol Oral Radiol Endod. 2000 Nov;90(5):553-8.

    Morgan TA1, Burton CC, Qian F. A retrospective review of treatment of the odontogenic keratocyst.J Oral Maxillofac Surg. 2005 May;63(5):635-9.

    Byun JH, Kang YH, Choi MJ, Park BW.Expansile keratocystic odontogenic tumor in the maxilla: immunohistochemical studies and review of literature.Korean Assoc Oral Maxillofac Surg. 2013 Aug;39(4):182-7. doi: 10.5125/jkaoms.2013.39.4.182. Epub 2013 Aug 23.

  • Jing-Zhe Jiang asked a question in Negative Staining:
    How to prove the surface of a DNA-protein complex is covered by DNA or Protein?

    I have a spherical dsDNA-protein complex, which diameter is about 30nm under negative staining in EM. We suspect it was covered by dsDNA instead of protein because the contrast of its image is not as clear as typic protein structure under negative staining. However, the dsDNA of the complex can resist the degradation of DNase I. If I want to prove the surface of a DNA-protein complex is covered by DNA or Protein, is there any other methods to use?

    Thank you!

  • Sarah Dsane added an answer in Education:
    What would you prefer: daughter’s higher education or son’s higher education? And why?

    In an extreme case and in some parts of the world it can be a real case, if parents have financial capacity to send only ONE of their two children to school for a higher education - they have one son and one daughter. In your view, which one should they prefer to send to school for higher education? Their son or daughter? And why?

    Sarah Dsane · National Film and Television Institute

    If a daughter seems brilliant and can cope with academic work better than a son I would prefer to send a daughter. This is because for me we all have our fields of excellence and if a son will do better in art and can perform better by understudying someone high school and be able make it in life without attending a university so much the better for him..  

  • Varun Penmatsa asked a question in Structural Testing:
    Residue when etching SiO2 using CF4 plasma?

    I am trying to etch 3um vias through 300nm SiO2 using CF4 plasma. These vias connect top ITO layer with bottom metal layer. After CF4 etching, I am able to confirm through the 500um circular vias test structures that SiO2 is completely etched but am unable to get electrical connection through the 3um vias (I have separate test structure to test the connectivity between the two metal layers). I am guessing there might be some hydrocarbon residue from the CF4 etching. Please provide suggestions/ comments on how to solve the problem. I do a low power O2 plasma etching to remove residual photoresist.