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

  • Shivani Poornima added an answer in Sleep Medicine:
    Does anyone know of anyone in the US or somewhere else who is effectively treating those with delayed sleep phase syndrome?

    There is a facebook group with almost 1500 people on it who have delayed sleep phase syndrome, and I've been told that most of them have no idea where to go for effective treatment.  I think many to most of these people have had sleep medicine doctors, but nothing they've suggested has helped.  Does anyone know of some experts with effective clinical treatment in this area where these patients are not being referred?  Thanks!

  • Frank Gräbner added an answer in Ferrites:
    Can anyone answer this question on Microwave Absorption-Ferrites?

    Recently, i measured absorbed power of ferrite sample backed by metal plate in rectangular waveguide (ATD method). One of the composition reflects all the microwave signal falling on it i.e. no absorption. (i) When i removed metal plate, it exhibited same behavior (just to check signal is not reflected from plate). Its e' and e" varies from 15-13 and 22-16 at X-band, where as for other compositions e' and e" varies 9-8 and 1- 0.1.
    (ii) Then i placed the composition by angle 90 (thickness-5mm) w.r.t. previous position (length=waveguide length). Now there was lot of air gap, since composition was covering only 5mm end of waveguide.
    I used CRO to display the signal passed through the sample in both cases and in both cases it does not pass the signal through it. The interesting point is of second case, how composition, covering only 5mm of W/G end, does not pass signal. I did it in three positions i.e. placing composition in centre and both sides waveguide end.

    I think this is very interesting phenomenon, it has strong polarization and loss as well but why it reflects the signal in case (i) and (ii) at all freq. of X-band? There can be scattering in case (i), but i don't understand how signal is not able to pass through air gap of more than 1 cm with just 5mm taken by composition.
    (u' and u" are minimum in all compositions).

    Frank Gräbner

    Dear Mr. Singh,

    you have 2 ferrite cases. If you have a anisotrope ferrite, then you have a polarisation effect for the absorption. If you have a isotrope ferrite , then a matching of the impedance of the field to the ferrite material.

    This is interesting.

    Sincerely yours

    F. Gräbner

  • Yuan-Yeu Yau added an answer in Botany:
    What is land scalping and what is the significance?

    Land scalping in botany, what is it all about?

    Yuan-Yeu Yau

    Attached is an article with more complete lists of the importance of landscaping involved plants.

  • Akash Mondal added an answer in Neural Network Model:
    Which open source simulators are used for IoT and neurual networks?

    I need tools to build, test and evaluate IoT and neural network models?

    Akash Mondal

    I agree that NetSim is an excellent tool. There support is very good too

  • Tatsuo Tabata added an answer in Cultural Communication:
    Kung Hei Fat Choi! Are you, your country, town or community celebrating the New Chinese Lunar Year of the Fire Monkey?

    In 2007, we have started an ongoing research project on “Globalization of Holidays and the Calendar”. In the beginning, we were only interested in trying to understand the rapid spread of holidays that, as Halloween and St. Valentine, didn’t have any cultural tradition in Chinese communities but became an important economic asset as well as festivals mobilizing casinos, hotels, restaurants, then schools and associations, nowadays firmly installed in social networks exchanges. Thereafter, we have also started studying the diffusion of public and private festivities of the New Lunar Chinese Year along with the growing economic presence of China worldwide. We have been systematically inviting Master and PhD students to research the topic and I would like to appeal to your collaboration. Can you give us information, pictures, videos or any other documents regarding the diverse celebrations of the Chinese New Year in our country, town or local communities? If there aren’t any commemorations at all, can you explain the situation? What do you think about this clear globalization, industrialization and marketization of holidays that, in some cases relatively new, are being celebrated among other cultures and communities? Is there a main economic driven factor or there also are much more complex cultural and social elements?

    Tatsuo Tabata

    Attached is a news article with a photo of the annual Nagasaki Lantern Festival in Nagasaki, Japan, to celebrate the Chinese New Year. Similar festivals are also held in Yokohama and Kobe. In each of these cities, there is a rather big China town. Japanese people also enjoy festivals there.

  • Ahmed Elazab added an answer in Image Segmentation:
    Which software is good at obtaining ground truth for the 3D heart vessels?

    Hi. Iam segmenting  heart vessels. i need ground truth data . Which software is good at obtaining ground truth for the 3D heart vessels?

    Ahmed Elazab

    Ground truths are usually created by experts, practitioners, and/or radiologists for the image/volume under study not by software. Ground truth are considered as the perfect or perfect most accurate segmentation. Then you use the ground truth to compare the accuracy of  your segmentation with it, mostly using Dice coefficient, Jaccard similarity or Hausdorff distance.

    You better use standard dataset or publicly available database to avoid this obstacle as if you tried to make the ground truth is very time consuming and definitely requires a lot of experience which mostly not available for junior researchers.

    Good Luck 

  • Awais Mirza asked a question in Research Papers:
    How to cite famous methods like "Arithmetic Mean" or "Geometric Mean" in the reference section of research paper?

    While using such methods within a research paper, how can we mention them in Reference section.

  • Shekhar Reddy added an answer in Reaction Mechanisms:
    Gloyoxalic acid reaction with sulfuric acid mechanism?

    to prepare the mandelic acid

    Shekhar Reddy

    thnak you Brennan and Rafik for your response

  • Jasmin Ćosić added an answer in Ontologies:
    Is there any contextual ontology for business concepts ?

    When using domain-specific ontologies for describing business collaboration, the used concepts (or more precisely, the value of the concept) my have different contextual interpretations according to the local business context (e.g. for the concept "Price" there is many contextual dimensions : Currency, VAT, Date, etc.)

  • Dres Damgaard added an answer in In Vitro Techniques:
    The factors that influence In vitro calcium availability result?

    We are checking on different sources of calcium and it is giving different result of the calcium availabiilty via in vitro study. It is suspected that the solubility of the calcium may become one of the factor. However, just wonder whether the molecular size, type of calcium sources (manually synthesis from raw sources or chemically synthesis), the sample preparation or other factors may influence as well. Hope to get further explanation. Thank you in advance! 

    Dres Damgaard

    I am not sure if the same applies to your sources of calcium, but we are doing studies where calcium (CaCl2) is an activator and at only >0.5% PBS we can see an effect (phophate binds calcium), thus PBS might influence your study if any steps/reagents includes PBS.

  • Syed A Ali added an answer in Adeno-associated Virus:
    Virus particle purification?

    I am transfecting T293 cells with pAAV (adeno-associated virus vector). How can I purify the recombinant virus after transfection?

    Syed A Ali


    You may want to go through this paper:


  • Anoop Kumar Srivastava added an answer in Nutrients:
    Even though, STCR based SSNM studies has been thoroughly done in Agricultural crops, Why research is so scanty in Horticulture using STCR approach??

    In the era of sustainability, soil test based fertilizer approach is one of the viable options for the dynamic adjustment of nutrients based on soil fertility status. Even though STCR based SSNM concept emerged in the early 1960's and a lot of research has been done on food grains and cereal crops, why that kind of research has not implemented in flower crops till now. How far it is worthful if we follow in flower crops too???

    Anoop Kumar Srivastava

    You are dead right Lakshmi . Horticultural crops are not mandated under   NRM division of ICAR. And soil scientists working under Hort. Div., you can count them on fingers . Flower crops , I do not think ,  its worth trying , for the simple reason , its not  so much nutrient extracting compared to fruits and vegatables to some extent .

  • Kamal Ahmed added an answer in Climate Data:
    Any suggestions of reliable data bases (websites) offer daily observed climate data for cities around the world especially those in The Middle East?

    I need daily observed historical climate data (precipitation and temperature mainly) for surface water basin shared between Jordan and Syria. I have date for the Jordanian side from the ministry but none from the Syrian side. Someone suggested on me that many organisations already over those data with proper manipulation such as United Nations (UN) in specific websites. So anyone can provide me to these websites links and which is the best and reliable.

    Thank you in advance 

    Kamal Ahmed

    Dear  Alham

    There are number of data sets available that can be used. You can visit following link


    You can try APHRODITE products, they have a version for middle east (Middle East (ME_V0902)).

    Reliability of theses datasets can be assessed by comparing with some of observed data already available with you.


  • Raymond J Ritchie added an answer in Chlamydomonas:
    Why is it that Chlamydomonas is the preferred chlorophyte for hydrogen production?

    Greetings colleagues,

    Why is it that Chlamydomonas is the preferred chlorophyte for hydrogen production?

    “Chlamydomonas AND hydrogen” have 1365 hits on web of science, compared to only 829 for chlorella, and the Chlamy publications enjoy substantially higher rates of citation (admittedly not the best method of determining the degree to which a subject is studied). Chlorella grows more prolifically and in my understanding does much better when scaled up. Is Chlamydomonas simply better at producing hydrogen, if so is this a function of its hydrogenase concentration, superior hydrogen pathway isozymes, or another factor? If any of you have definite figures on the maximum H2 evolution rates from the two species that would be much appreciated, with the various strains and culture conditions being tested I have found it challenging to find a discrete maximum H2 production rate in the literature.

    Cheers, J

    Raymond J Ritchie

    Jonathan - Photosynthetic bacteria can be photoheterotrophic and photoautotrophic depending on the strain.  The isolation procedures used by microbiologists use organic carbon sources and so there is a great deal of isolation bias.  Rhodopseudomonas palustris will use almost any organic compound to grow on including dirty used cooking oil, acetate, jet fuel, toluene, moth balls, benzoic acid and waste from all sorts of food processing including oil palm oil sludges.  There is an awful lot of waste fixed carbon around.

  • Raghul Damodaran asked a question in Tissue Regeneration:
    What ratio of hydroxyapatite can be reinforced with polymer for bone tissue regeneration scaffold?

    Project is based on biodegradable materials.

  • Monica Jolly added an answer in Agarose Gel Electrophoresis:
    How to purify a high molecular weight DNA fragment (>10kb) from agarose gel?

    Needs some expert advice in purifying a 10,3000 kb fragment (after restriction) from agarose gel? I am getting very low yield, only few ngs!!! whereas my starting concentrations is more than 5 ugs. Any suggestions!

    Monica Jolly

    i am sure gel extraction kit for high mol wt DNA works well . Try Zymoclean™ Gel DNA Recovery Kit (for DNA 11 kb to 23 kb the recovery is 50-70%.)

  • Catalin Lazar added an answer in Romania:
    Does anybody know rectangular pot-stands from Neolithic or other prehistoric periods?

    Does anybody know support-pots with a rectangular shape such as those from the attached picture dated in Neolithic or other prehistoric periods?
    In Romania, they are specific to Boian culture, final phases (ca. 5000-4500 BC).

    Thanks in advance.

    Catalin Lazar

    Dear Martin,

    Thanks for the info. 

    Best wishes,


  • Mazhar Ali added an answer in Sociology of Religion:
    Are you aware of any articles about impact of religiosity on brand switching intentions especially in context of Islam?

    looking for articles about impact of religiosity on brand switching.Product should not be food or clothing.

    Mazhar Ali

    i have read it. anyways thanks

  • Guan Wang asked a question in shRNA:
    How to test siRNA or shRNA silence efficiency toward PD-1?

    I want to test siRNA or shRNA silence efficiency toward PD-1 in whatever cell lines, just to make sure that our siRNA sequence works. Which way is the easiest, WB, FACS or qRTPCR? which cell line should be used that produce much PD1? Can IFNγ stimulate T cell line to produce more PD1 which is just good to be used? Can I transduce virus to stimulate PD1 level, and then silence it? Thank you

  • Jasmin Ćosić added an answer in Ontology:
    How can I assess the complexity of ontologies?

    I need to design my case experiments to address both a simple ontology and a complex ontology. How can I quantify ontologies in terms of the number of classes, entities, etc?

  • Vladimir Puzovic asked a question in Peripheral Nerves:
    Article about peripheral nerve vascular system?

    Dear professors, colleagues and friends does anybody know a good review article about peripheral nerve vascular system, micro-circulation inside peripheral nerve and similar topics?

    Thanks for help!


  • Michael Cuellar added an answer in Big Data Analysis:
    How to pick a topic for research?

    I have been recently enrolled in PhD Computer Science program and studying Research Methodology subject where my supervisor assign me to pick a topic of your interest for RM subject which will later lead you to Independent study I & II in next two semesters. My PhD thesis will be started after completion of my course work of 18 credit hours. I am studying Research Methodology, advance algorithms & Analysis (Semester-I), Advance Data mining , Independent Study-I (Semester-II) and Machine Learning, Independent Study-II (Semester-III). Objective of Research Methodology class is to implement paper review techniques, methods, processes, criticism . . . . on your chosen topic and at the end of the semester deliver a presentation and report in the form of quality Research paper. I have to explore minimum 12 research papers of last 5 years on my picked topic being approved by my supervisor. My plan to do my PhD in the domain Business Intelligence, big data analysis, data mining, prediction, analytics or any area relating to that. I have already done MS in Business Intelligence and a decade experience in Telecom BI. Can someone guide me which topic should I choose for my RM subject where Problem statement must be presented? Here I want to lock my plan for Independent study-I & II topics and my PhD Research area as well. If you have any supportive material please email me on shoaib.malik80@gmail.com or +923018541575 (Whats app)


    Michael Cuellar

    Doing your dissertation in BI is a good topic. It is the current hot area in the field. 

    I would have thought surely a decade in practice would have generate a series of research questions that you would like to have answered. I'm surprised that you entered a PhD program from practice without one. 

    Some questions that you might might want to answer might include such things a developing new analytical techniques to tease out patterns in the data that might be useful. You probably have an idea for a few of them that you wished you had from practice.

    Another area is developing an advance on Hadoop/MapReduce for handling large data, perhaps using grid computing.

    Another area is handling missing data, dirty data. Perhaps you can find improved methodologies for resolving these areas.

    Improved data visualization techniques are always interesting.

    Another area is improved analysis of textual data. Text Analytics is probably the wild west in analytics. if you could provide an advance on LSI that actually identifies the semantic content of data and then correlates it and extract meanings and trends, this would be a major contribution.

    Anyway .... some ideas.

    Best regards,

  • Han Ping Fung added an answer in 3D Printing:
    What are the hurdles in implementation of 3D Printing for complex and sensitive products ? what are the essentials to achieve this success ?

    can anybody suggest me , what kind of facilities/ services are not supporting to produce the complex and sensitive products (physical components) at the points of consumption ? 

    Han Ping Fung

    Some of the inhibitors for 3D printing can be found in the following links inter alia:

    1. The 3D printed parts typically not strong as its objective mainly for prototyping.
    2. Possible accuracy problem as its primary objective is for prototyping.
    3. 3D printing takes longer time to produce its per unit output vs traditional mass production.
    4. Large amount of energy consumption of 3D printer compare to traditional mass production.
    5. Since technology change very fast, there should be solution to provide upgradable 3D printer design.
    6. Difficulty to introduce recycled materials so that 3D printer output can be easily recycled into 3D printer input / raw materials.
    7. Limited size of the 3D printed parts / output that can be produced.
    8. How to control the 3D printing of dangerous items like guns, knife etc.
    9. Violating copyright that can raise ethical concerns.
    10. Increasing number of counterfeit products that can damage authentic branded products.







  • S R Salakinkop added an answer in Organic Waste:
    How can I stop a habit of a community to burn up organic waste?

    socialize waste management 3 R in community...

    S R Salakinkop

    Practical way of recycling is sorting at household level. degradable waste can be heaped,watered and covered with thin layer of soil so as make best compost out of wastes. Product thus prepared can be used for improving fertility of soil  for crop production and garden.

  • Ankur Jyoti Saikia added an answer in Plant Biology:
    Flowering of Dendrocalamus gianteus?

     Is there any scope of work with respect to flowering in flowering of Dendrocalamus gianteus?

    Ankur Jyoti Saikia

    Thanks Dr. Singh and Dr. Mitra.

  • Nithyanandan Manickam asked a question in Kuwait:
    A goby fish from Kuwait, can anyone help on the ID?

    Dear All,

    Recorded this Goby in a sandy patch adjacent to seagrass meadow at 2 m depth in Kuwait. The goby was approximately 3 cm in total length. Can someone help on the ID?

    Best Regards,

    M. Nithyanandan

  • Dalia Yacout asked a question in Aquaculture:
    What are the most common formulas for aquaculture feed ?

    I am looking for the most common formulas for aquaculture feed 

  • Richard Peterson added an answer in LabVIEW:
    How can we control a turbo molecular pump based on Pfeiffer technology remotely using LabVIEW ?
    Basically, we need to monitor TMP vacuum,etc parameters as well as to turn ON / OFF it remotely, if possible.
    Richard Peterson

    Hello everyone my research group is looking to remote control our Pfeiffer turbo pumps through LabVIEW.  If any of you had any luck could you give me some pointers.

  • Su-Lin L Leong added an answer in Fungi:
    Ochratoxin A producing strain?

    Would you be able to provide an ochratoxin A producing strain of fungi, preferably its toxin production conditions are well characterized and optimized for high OTA production and also free of other toxins.

    Thank you in advance.

    Su-Lin L Leong

    Could I ask what you want to do with the strain? If you are looking at biosynthesis / molecular biology / chemistry of ochratoxin A, then the A. ochraceus strain provided by a colleague should be fine.

    If the strain is for ecological studies, then please select the relevant species for the ecological system you are examining. For example, much of the ochratoxin A contamination in dried foods associated with contamination of yellow Aspergilli is made by A. westerdijkiae and A. steynii, not necessarily A. ochraceus. These first two species look similar to A. ochraceus but were separated out from A. ochraceus, and they usually make higher levels of ochratoxin A than A. ochraceus. The black Aspergilli, particularly A. carbonarius is the most relevant ochratoxin A producer in grapes, also in coffee (together with yellow Aspergilli). Penicillium verrucosum and P. nordicum are relevant in dried grain in temperate climates, cheese and cured meats, etc.