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.

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  • Rush Qq asked a question in Professional Identity:
    Consider having a professional identity as a tutors?

    That is, when he is granted the status of tutor deemed not necessary to build a professional identity to execute that role.

  • Khondokar Fida Hasan added an answer in Thin Films:
    Which articles should we prefer to cite in our publications, review papers or original research reports?
    As more and more research articles are published every year, it is understood that to cite review papers is a convenient way and save our time to dig into original reports. The number of review publications is also rapidly growing apparently. Related to this question, how should we value the review publications and original research reports?
    Khondokar Fida Hasan · Queensland University of Technology

    I think, it is always better to cite the original work unless otherwise they are not available, in such case citing survey is well considerable.

  • Xu Ji added an answer in Nanocrystals:
    Does anyone know how fluoride etching cause a red shift in the emission Wavelength of semiconductor nanocrystals?

    I am dealing with a strange case in my research and I could not find a proper answer in literature.

    My problem is basically related to spectral changes of carbon nanocrystals (doped with sulfur) upon addition of potassium fluoride. Based on the scientific reports on the effect of fluoride etching on band edge emission of Quantum dots, etching cause surface traps to be removed , therefore the emission wavelength shows a blue shift accompanying with signal enhancement.

    Although I can see signal enhancement, I cannot explain the red shift observed in my system upon addition of fluoride.

    Xu Ji · Sun Yat-Sen University

    the HF etching treatment of semiconductor nanocrystals removes or passivates surface states to produce bandedge luminescence

  • What is the link between Urban and regional development planning and policy and International migration?

    Specifically the role of planning and policy in international migration issues especially on the receiving countries of immigrants especially developing ones. Key articles are welcome

    Richard John Smith · Wayne State University

    I have a few working papers about these issues. I am looking at the United States primarily. I would look at the work on immigrant and ethnic enclaves and how that fits into broader urban theories about land rent, succession, spatial assimilation, gentrification and right to the city. In the US, immigrant integration has been coordinated at the Federal level by the State Department, Homeland Security, and Health and Human Services. Urban Development is mostly the US Dept. of Housing and Urban Development, but also Commerce, Transportation, Treasury and more. In the past five years, efforts to link the two issues has been getting a great deal of attention. 

  • Is there a simple protocol for extraction of genomic DNA in archaea?

    Hello everybody, I am looking for a simple protocol or commercial kit for genomic DNA extraction from hyperthermophilic Archaea (e.g., P. furiosus)

    Ravi Luckhun · University of Mauritius

    You can use modified Takai and Sako (1999) and Anton et al. (2000) methods for DNA extraction.

  • Nimmy JOSE Jose added an answer in Marine Biology:
    Are there any publications comparing the soil organic carbon (SOC) in different coastal regions?
    The amount of SOC depends on soil texture, climate, vegetation and historical and current land use/management. Soil texture affects SOC because of the stabilizing properties that clay has on organic matter. Organic matter can be trapped in the very small spaces between clay particles making them inaccessible to micro-organisms and therefore slowing decomposition. In addition, clay offers chemical protection to organic matter through adsorption onto clay surfaces, which again prevents organic matter from being decomposed by bacteria.
    Nimmy JOSE Jose · Kerala Agricultural University

    The organic carbon status of the soils of Kuttanad, identiifed as Globally Important Agriculture Heritage sysytem by FAO, in kerala, India  for the below sea level farming system has rice fields reclaimed from lake. The SOC status is very high 2-3% and clay content is 40-50 %. There are records and even publications on the SOC of the coastal regions of Kuttanad and other coastal belts of Kerala  maintained by Kerala Agicultural University.

  • Any one can explain the techniques which are used to measure the level of nutrition in human body?

    Nutrition, nourishment, or aliment, is the supply of materials - food - required by organisms and cells to stay alive. In science and human medicine, nutrition is the science or practice of consuming and utilizing foods.
    In hospitals, nutrition may refer to the food requirements of patients, including nutritional solutions delivered via an IV (intravenous) or IG (intragastric) tube.

    Muhammad Iqbal Basagili · Gadjah Mada University

    there are so many nutrition in human body such as vitamins, minerals, kind of proteins. and each of them has different technique to identify in human body. Could you specify what nutrition do you mean?

  • Yu Wei Chen asked a question in EDC:
    RGD or DGR, which one can bind intergrin?

    Hi everyone, recently I have been trying to conjugate the RGD peptides onto my nanoparticle in order to target the intergrin. But when I was to use EDC/NHS to react with the N terminal of the RGD, I am not sure whether to buy GGGRGD or GGGDGR (G is my N terminal and would react with COOH -containing ligands already  bound to my NPs) Should I buy GGGRGD or the other instead?

    Thanks for answering!!

    P.S the GGG sequence acts as spacer.

  • How can one design an Air Electric Heater to heat air up to 700C?

    I tried to heat air with flow of 5L/sec from 30oC up to 700oC through a tubular electric heater, as illustrated in the pictures. I used kanthal wires three coils, with 150V*15A*3=6.75kw.

    But the max. Temp. was 200oC.
    Do you think increasing the pathway of air as illustrated in the attached drawing to increase the pathway 3 times could enable to achieve 700oC.

    Any, suggestion, Please.

    Best Regards!

    Azd.

    Maddali V S Murali Krishna · Chaitanya Bharathi Institute of Technology

    By using Newton's law of convection, q=hA (Dfference of temp). h value is known to us, whether it is forced circuation (h=130 units) bor free and natural circulation (h= 100 units, q can be suotably assumed. ( 500 Watts or 1000 W). Hence area of the coil can be estimated from which diameter of the coil can be determined. This is some what simple calculation, rather than assuming dimensionless numbers from which coil diameter can be esitmated.

  • Ravi Luckhun added an answer in Plants:
    How do we confirm that a plant encountered is a new species or not?

    Suppose we encounter a plant in an area and going through the published literature or flora of that place does not provide any ample proof of its record. What are the necessary steps that we must take to establish that the plant is a new record or not?

    Ravi Luckhun · University of Mauritius

    Dear Mr Goyal,

    To confirm the discovery of a new species, as mentioned in the previous comments, you will need to be sure that you have verified everything, including books, consultation in herbarium, local people etc.

    Now if you are not able to find the closest relatives to classify it, DNA barcoding remains an option, though it is quite costly. Good Luck.

  • Can we measure motivation in students?Are there any standardized questionnaire to measure?

    This question is regarding medical education.

    a) How will we know that a student is motivated to learn the subject ?

    b) Is it intrinsic motivation or extrinsic motivation?

    Saileela Kondapaneni · Kamineni Institute of Medical Sciences

    thank you for your interest.  I am not aware of the curriculum in your medical school.

    my work is regarding -how much case studies can influence the motivation in students in learning medical Microbiology?

  • Nimmy JOSE Jose added an answer in Soil Fertility:
    How can we apply wood ash to field properly to avoid its spread to neighbouring fields and other losses?

    I want to conduct a field experiment to study the effect of wood ash on crop productivity and soil fertility.

    Nimmy JOSE Jose · Kerala Agricultural University

    As done in the case of application of Rock phosphate which is available in the powder form, moisten the ash and apply it in moist soil to avoid drift 

  • Diem Phuong Nguyen added an answer in Proteinases:
    Should we purify Metalloproteinase 9 (MMP-9) after being activated by p-aminophenylmercuric acetate?

    Hello, is there anybody currently working on cell-secreted protease which is mainly focused on Matrix Metalloproteinase 9?

    I'm new to cell manipulation research. I'd like to ask whether we should purify Metalloproteinase 9 (MMP-9) after being activated by p-aminophenylmercuric acetate?

    I'm working to figure out the catalytic activity of MMP-9 on a customed peptide and I need to make sure the proenzyme form is totally converted into active form (My proenzyme is from Sigma). Is it necessary to add p-aminophenylmercuric acetate to activate the cell-secreted MMP-9, too?

    Thank you for reading,

    Diem Phuong Nguyen · Chung-Ang University

    To Dr. Sangeetha and Dr. Stefansson:Thank you so much for your valuable advices!

  • Jesus Alezones added an answer in Maize:
    What is the latest management practice for stalk rot of maize?

    What is the latest management practice for stalk rot of maize?

    stalk rot of maize/corn

    Jesus Alezones · Fundacion Danac

    Stalk rot in maize is a complex disorder caused by several pathogens like Cephalosporium, Fusarium, Pythium, Colletotrichum, Macrophomina, Botryodiplodia or Diplodia. Each one of these pathogens grows better under determinate environmental conditions. First you have to determine what kind of fungus is affecting the maize in your area and then you can develop a strategy for control, for example if the fungus grows better under very humid soils it´s possible control it by improving soil drainage. On the other hand several maize hybrids and varieties are very resistant to these pathogens. Other very useful strategy for fungus like Pythium and others oomycets is the use of fungicide (Methalaxyl / Mefenoxam) treated seeds. Right know in the market are modern fungicide molecules that protect maize in early stages like Fludioxonil or Sedaxane.

  • Is there a study to show to what extent testosterone act via convertion to its metabolites than by itself.

    As evidenced testosterone can be metabolized to its derivatives estrogen or dihydrotestosterone and then exert some its function thereafter. specially in males, it is a question for me that what portion of all functions contributed to the testosterone is related to testosterone itself and what portion is related to its metabolites particularly estrogen.  

  • Saileela Kondapaneni added an answer in Coagulase:
    Can anyone suggest methods for coagulase tests using Citrated plasma?

    I am about to perform the coagulase test on a large number of clinical isolates, to do so I purchased 300 ml of human plasma from the blood bank (it will be more cost effective than lyophilized rabbit plasma especially because I am surveying a large number of isolates ). I found that some sources say that "citrate utilizers" could consume citrate and give false positive results, but in my case I have already done many tests before coagulase "microscopical , catalase , mannitol salt agar "

    In this case, can I use Citrated plasma effectively or not?

    Saileela Kondapaneni · Kamineni Institute of Medical Sciences

    plasma should be diluted for tube coagulase test.

    1 in 5 dilution ( 1 part plasma +4 parts normal saline) 

    Coagulase reacting factor present in plasma is required for reaction . for this appropriate dilution is required

    over night culture broth is preferred to direct colony for  coagulase test because free coagulage should be released from organisms into broth. this is for better results.

  • What can I use as a replacement for STI-agarose?

    I am doing protein expression and purification and the protocol lists using STI-agarose for removing enterokinase. I am not able to find STI-agarose, so does anyone have recommendations for a replacement, or where I can buy it?

    Thanks!

    Wolfgang Schechinger · Chang Gung Memorial Hospital

    Hi Kelsey,

    if you google for "STI agarose", you should find at least one supplier. However, I'd rather prepare it myself: Get some soybean trypsin inhibitor (STI) and couple it to NHS activated cross-linked agarose (AKA NHS-activated Sepharose) at about 1...5mg/ml resin.

  • Kamlesh Shah added an answer in Fusarium:
    Fusarium fungus

    I want to know more about how fusarium grow on media, what are the stages of life. What is conidia, spores, siri (misspelled)? How can I find a region in the genome using RFLPs and PCR? Also what are the stages in sexual and asexual reproduction resulting in 8 ascospores. Thank you so much for the help. 

    Kamlesh Shah · Pramukh Swami Science & H.D.Patel Arts College

    you can grow fusarium om PDA or RBA medium after Growth of 3- 4 days you can have perfect sporulation. 

  • Lev Kra added an answer in Utrophin:
    How would one attach a myosin-promoter upstream of a gene that regulates utrophin production?

    Gene therapy experiment where I am trying to produce muscle specific expression of the artificial gene UtroUp in cells infected with Duchenne Muscular Dystrophy.

    Lev Kra · Bergen County Academies

    The intended purpose of the myosin-promoter (which after doing some more research I plan to change to an alpha-actin promoter) is to facilitate muscle specific expression of the gene I plan to insert. And currently I'm deciding between an adenovirus or plasmid vector.

    I'm also looking into the process for synthesizing genes on GenScript so I'll get back to you on that shortly.

  • Louis Altamura asked a question in Westerns:
    Has anyone used the ProteinSimple Wes capillary western blot system?

    Does it work as well as advertised? How does it compare to traditional westerns?

  • Zuhaib Haider added an answer in MATLAB:
    How can I generate lorentzian and gaussian profiles with the same FWHM using Matlab?

    I want to plot Gaussian and Lorentzian functions with the same FWHM using matlab. If anyone have any idea about how to do it, kindly guide me.

    Regards

    Zuhaib Haider · Universiti Teknologi Malaysia

    I used respective functions and input same values to FWHM variable. It went fine.

    Thanks :)

  • Yan Chen added an answer in Immunohistochemistry:
    Does anyone have a good protocol for detection of CK19 in the liver tissues by immunohistochemistry?

    I hope to find a good protocol for detection  of CK19 in the liver tissues by immunohistochemistry. 

    Yan Chen · The University of Hong Kong

    Dear Ivan

    Is your antibody working well with mouse liver? where do you purchase? using santa cruz CK19, I cannot get any signal from mouse liver, but very good for human liver samples

  • Post Cholecystectomy Syndrome?

    Has anybody experienced, or noticed that most patients after about 12 months after Cholecystectomy present, frequently watery diarrhea, skin rash with allergy, bone or articulation pains without trauma and unspecific anxiety, apart from other relative laboratory analysis like Cholesterol, Liver enzymes etc.   

    Prasanna Kumar Reddy · Apollo Hospitals

    Dear Rasheed,I  mentioned in one of our previous discussions we have large numbers

    but we do see diarrhoea and dyspeptic symptoms but I have not come across other symptoms and signs mentioned.Interesting to note the physiological theories mentioned.

  • ¿Which is the optimal number of reads per sample in a library?

    Hi

    I'd like know which's the optimal number of reads per sample in a library obtained by genotyping by sequencing, I have differences in the reads por example

    Code plate reads
    C8 278
    G9 1876
    . .
    . .
    . .
    C9 7668388
    A10 8204584

    I have 96 samples ranging from 278 to 8204584, Which use? a optimal range? I'm working in discovery SNP in a native tree chilean, without reference genome.

  • Cloud Jon added an answer in Bioenergy:
    What is the current scope of bioenergy or biofuels?
    For last 5-6 years, the words bioenergy and biofuel are gaining much publicity, but we are still using non-renewable petroleum-based products as fuels. So much research has been done and currently going on the field of bioenergy & biofuels, but still the commercialization of these has not been undertaken. What do you think; Is it economical to make bioenergy & biofuels commercial? Are they more efficient than petro-based products?
    Cloud Jon · Cloud Holding Inc.

    Kunal,

    I would like to clarify a large misconception held by most people and stated in your original "call for discussion."  Petroleum is in fact a natural and renewal product.  Starting about 3.4 billion years ago the Earth's production of algae began in earnest.  The algae contained varying percentages of oil within their bodies.  The dead marine algae drifted to the bottom of the oceans and form sediments.  Once the sediments reached 4,000 feet in depth the oil had been squeezed out and collected in the sponge-like rock structure of the sedimented material.  

    So, petroleum is actually from algae and diatoms produced billions of years ago.  The processes used by biofuel production is simply an acceleration of this process.  How can we then say petroleum is not renewable.  In fact it is being renewed as we speak. 

  • Thomas Marcussen added an answer in Phylogenetics:
    Is it possible to detect hybridization using PhyloNet?

    Dear all,

      We have four species. However, we are not able to get a certain phylogenetic relationship between them after several runs of starBeast. We suppose that it is a signal of hybridization for one of the four species. So, is it possible to detect hybridization using PhyloNet? Our data contains multiple sequences for each species, and each species were sequenced by 9 loci. 

          Any advice would be appreciated.

    Thomas Marcussen · Norwegian University of Life Sciences (UMB)

    Before doing anything more fancy, please make sure that the *BEAST analyses have run long enough for proper mixing to have occurred. All ESS values should be >200. Analyses with many OTUs and many genes may have to run for several hundred million generations, especially if you do not use a strict clock.

    Yes, it is possible to use Phylonet. But note that the program uses tree topology only to place onto the phylogeny (by parsimony/likelihood) the number of hybridisation events *a priori* specified by the user. You will therefore need to run several analyses, each with a different number of hybridisations, and the program does not tell you what is the optimal number, which is a drawback. Also, coalescent stochasticity (i.e. branch length) is not considered, and with only nine genes you'll probably need to explore all aspects of the data and not just topology.

    What might be helpful is to generate a (rooted) chronogram for each gene, extract coalescence times for each pair of OTUs, and use those data to estimate pairwise genome divergence times under the multispecies coalescent. Plotting that distance matrix as a splits network should enable you to see more clearly between which samples hybridisation may have happened. For details, you could check the supplementary data of https://www.researchgate.net/publication/264004279_Ancient_hybridizations_among_the_ancestral_genomes_of_bread_wheat

    I hope this was helpful.

  • Dima Lisin added an answer in SIFT:
    How to track Rotation and scale invarint features without sift & surf?

    In my images,sometime i don't get feature with sift algorithm so how to track scale and rotation invariant features?

    Dima Lisin · The MathWorks, Inc

    If you need to track points, try the KLT (Kanade-Lucas-Tomasi) algorithm.  It is available in the Computer Vision System Toolbox:

    http://www.mathworks.com/help/vision/ref/vision.pointtracker-class.html

  • Cecile Furstenberg asked a question in Aristotle:
    Logic and Ethic/ Aristotle

    Which links exist between the logic in De Interpretatione and the ethic of Nicomac, between truth and good for Aristotle? Would you say that there is an implicit logic in the Ethic or that the purpose of good in a way means truth? 

  • Veena Anand added an answer in Database Management:
    Cdms for investigator initiated trials

    how to use excel effectively as a clinical database management system? any other program useful for investigator initiated trials in resource limited setting

    Veena Anand · T.D. Medical College

    which one is better  and easy reg installation and maintenance redcap or openclinica for an individual investigator not institutions