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  • Curious about your main assumption regarding high-fat diets: Is there significant evidence that you could cite that supports your claims?
    The premise at the top of your study, "Consumption of high-fat foods is one of the major causes of obesity," seems to me to be something that's been up for debate for some number of years now, with people actually losing weight on high-fat/low-carb diets. Is there significant evidence that you could cite that supports this claim? If this is your assumption on the outset, doesn't that naturally skew the parameters of the study?

    Aren't many obese people who consume high amounts of fat also impacted by other factors, such as thyroid disruptors in the environment; the excess of omega-6 oils in most packaged foods, high-carb + high fat diets, and sedentary work in temperature controlled environments?
    William Wilson · Wilson Institute of Neurobiology

    Michael--I respectfully disagree with your perspective. It is fat too simplistic for the complex world of biology. My friend Gary Taubes summed it up very well in this article:


    I sympathize with your perspective. If we could grind down biology into the simple perspective that your propose--it's all about the calories, then we could all go home and relax. Unfortunately that approach has not worked out very well. Let's give Mother Nature the respect she deserves and recognize the complexities of our world.

  • How can we identify propaganda and publicity in Public Relations?

    The question in other words is that even having clear cut academic definitions of Advertising, Propaganda ,Marketing , and Persuasion, it is very hard to differentiate them from Public Relations practices.Any tips?

    Lai Che Ching Abd.Latif · Universiti Malaysia Sabah (UMS)

    I tend to concur with Brendan Joseph, the boundary between public relations and propaganda is unclear. I know there are some attempts to differentiate between the two but it can only work in certain social/political condition. Because, public relations practice should be seen outward based on social and political condition.  

  • Yahya Al Naggar asked a question in Human Cell Lines:
    What is the best material used as human cell proliferation stimulants?

    i will test a new extract as  anti-proliferate to human cell line and  i need a proliferate stimulant? can anyone help?

  • Ashkan Khalili added an answer in Abaqus:
    How can I print out the global stiffness matrix in ABAQUS?

    Hi everyone,

    I'm using UEL in ABAQUS. My model just have one 4-node beam element (defined in UEL) fixed in one end.When I'm running the UEL, it's working without any problem. But when I'm trying to print out the global stiffness matrix I'm getting this error: "aborted with system error code 1073740940". This is the way that I'm trying to print it out:


    Would you please let me know What's the problem and how I can fix it?


    Ashkan Khalili · Mississippi State University


    Thanks for your valuable answer. It seems like a good point. I have to check it out to make sure. I will let you know about it.

    Best Regards,

  • Redar Tahsin Ismail added an answer in E-Commerce:
    What are the basic steps to analyze E-commerce data?

    I want to analyze the data of an online shopping site to improve our e-commerce business. Please suggest me some tools so I can achieve all needed requirements.

    or name some NLP, machine learning algorithms.

    Redar Tahsin Ismail · DePaul University


  • Sridhar Vadahanambi added an answer in Nano:
    Can anybody help locate published articles about nanotechnology in agriculture?

    Agriculture is an area where new technologies are often applied to improve the yield of crops. Nano agriculture involves the employment of Nano particles in agriculture these particles will impart some beneficial effects to crops. The emergence of nanotechnology and the development of new Nanodevices and Nanomaterials open up potential novel applications in agriculture and biotechnology. Nanoparticles are materials that are small enough to fall within the nanometric range, with at least one of their dimensions being less than a few hundred nanometers. 

    Sridhar Vadahanambi · Global Core Research Center for Ships and Offshore Plants,


  • Rajagopal Appavu added an answer in Liposomes:
    How can I purify or isolate the different sizes of liposomes?

    I have gold nanoparticle encap. liposome in different sizes in the flask. Please let me know how I can purify those different size liposome and protocol please.


    Many thanks Dr. Khalid Ferji, and Dr. Jaime Guillen. I am clear now.

  • Does anyone know which mechanism (s) deficient RecA E. coli use to make deletions/recombination in a plasmidial gene and how to avoid it?

    I have a library with variants of the same gene, and after selection steps (antibiotic resistance) I have observed a large number of variants with deletions. I don't have these deletions in my naive library, they are found only in the selected clones. I use the SNO 301 strain (AMPD1, ampA1, ampC8, pyrB, recA, rpsL) for screenings. Anybody have any suggestions about this issue?

    Kevin C Baldridge · University of Texas at Austin

    Just to clarify, is your strain recA, or ΔrecA? I don't believe recA deletion strains should recombine plasmids. From what you describe, it seems like you are probably selecting for deletion mutants in your selection. Any naive library will contain a certain level of indel mutants, but you may not be able to detect them in your initial library characterization if they are much less abundant than your point mutants (usually the case). The power and problem with selection experiments is that they can enrich for very rare variants, such as your deletion mutants.Without knowing more, it sounds like maybe that's what is happening. Alternatively, it might be that your other variants are all binding so well that your elution only releases the partial deletion mutants. Have you performed a mock selection with all appropriate controls with pre-defined pseudolibraries to ensure that your experimental procedure is indeed achieving what you think it's supposed to?

  • How can simulation be used to deliver an economic and environmental impact assessment of a new equipment/production system?

    My goal is to propose a methodology to assess the economic and environmental impact of a new equipment/technology/production system in manufacturing or remanufacturing processes by using simulation and proper KPIs

    I wonder:

    • what are the potentials and the shortcomings in using simulation (discrete event simulation particularly) for this kind of research goal
    • what are the alternative research methodologies (beyond that one above) to address this research goal.

    I warmly embrace answers ranging from the sharing of experiences in this field to references, when clearly connected to the topic.
    Thank you.

    Rajesh Vasudevan · Agency for Science, Technology and Research (A*STAR)

    I beleive economic impact of using new equipment/technology/production system is measuring productivity (labour, material, energy and capital). Environmental impact is energy consumption (electricity ->carbon footprint) which you can find out by simulation. potential of simulation is significant if it involves stochastic variables, scheduling and dispatching rules etc. For drawbacks , refer this  journal 'Warnings about simulation' by J Banks and L Chwif.

  • Hamed Sadabadi asked a question in ZnO:
    How to produce zno nanoparticles by combustion method?

    Thermal production method, precursore

  • Jiaqing Yi added an answer in Reverse Transcription:
    How can I do reverse transcription if the mRNA concentration is extremely low?

    I'm going to do RT-PCR on samples that have very low concentration of mRNA. How could I most effectively do the reverse transcription so that I can measure more gene expression. The concentration of the mRNA is 5 to 20 ng/ul. The current protocol that I have about reverse transcription allow me to measure 5 genes (including beta-actin). Does anyone know how to do it? Thank you so much.

    Jiaqing Yi · Virginia Polytechnic Institute and State University

    Thank you Jack for you insight about the pre-amplication of cDNA. I only have 20 ul of mRNA and yes, it's total RNA. I will try to contact the company to see whether they have some suggestions about the pre-amplication of cDNA. Thanks again:)

  • Victor Lopez-Martinez added an answer in Neuroptera:
    How many species of myrmeleontids can be found in Central Mexico?
    Recently I have seen some dense populations in Morelos and I am trying to determine this at species level.
    Victor Lopez-Martinez · Universidad Autónoma del Estado de Morelos

    Hi Roberto, I saw som pit builder species here in Morelos, but I cant identify it. You need adults or inmatures, or both? How I can sent entomological material to your lab?

    Best wishes

  • What is your opinion on psychometric testing? Is it a reliable? Can psychometric testing reflect a person's interest in reading?

    Psychometric testing refers to the process of measuring a candidate's relevant strengths and weaknesses. This form of measurement is primarily employed to assess employment suitability, including company-candidate fit.

    khairul baharein bin mohd noor · Kolej Poly-Tech Mara Kuala Lumpur

    Companies actually rely on this instrument to measure the soft skills of a candidate apart from interviewing. Hence, results shown to some extent, this instrument is reliable in determining the traits, attitudinal, behavioural aspects of a person.  

  • Graham W Pulford added an answer in Real Time:
    How can we measure the real time acceleration?

    How can we measure the real time acceleration and what is the mathematical formulation behind this?

    Graham W Pulford · Thales Group

    There is more than one way to measure acceleration. I assume you mean linear acceleration rather than angular. In an inertial navigation system it's basically a spring and a mass in each of the 3 dimensions x y and z. You measure the force on the spring via a sensor that converts linearly to an electrical voltage. The mathematical law is F = ma (Newton's second law). If this is not what you seek, please be more specific with your question.

  • Is anyone aware of any research on the impact of parent-child communication about weight on child's behaviour/wellbeing (helpful or harmful)?


    • Do changes in parent-child weight-related communication impact on children’s wellbeing and self-perceptions?
    • Do changes in parent-child weight-related communication impact on children’s eating or exercise behaviours and practices?
    • Are the effects of parent-child weight-related communication moderated by; child’s weight, age, gender, stimulus for weight talk, parenting style*
    • What are the specific strategies and techniques within interventions to improve adult-child weight-related communication associated with positive health or wellbeing outcomes?

    Leonard Goeirmanto · Universitas Mercu Buana

    Some articles in Clinical Psychology Review, Psychosocial Intervention,  Behavior Therapy, Appetite and Academic Pediatrics discussed about impact of parent-child communication in relation to eating behavior, social life and health.

  • Can you recommend a multi-criteria decision support tool using AHP for the site selection for the implementation of groundwater recharge aquifer ?

    By using GIS and remote sensing, I want to implement a project on water harvesting and I want to use the amount of harvested water in order to recharge the ground water in the study area. I want to know which are the best factors and how to rank factors by using AHP to estimate the best sites for recharge groundwater.

    Abeyou Wale Worqlul · Bahir Dar University

    Hi Faez, 

    Multi-criteria evaluation should be done by consultation with experienced experts, weighting factors is technology and site dependent. The procedures are simple; I have recently done irrigation suitability mapping using MCE you can find it in my RG (the title is Realistic Assessment of Irrigation Area Suitability). I will try to summarize you the procedures in short:
    1. You have to identify the major factors which affect the rain water harvesting technology that yu have in mind. Some of the factors will be for example soil, slope, land use, you can also have a map shoving the concavity and convexity of the topography.
    2. After identifying the factors the next procedure will be weighting. Out of the different weighting approaches AHP is less bias. For AHP just consult (Saaty 1977), you have to prepare a pairwise comparison matrix by using Saaty scale, then you can calculate the factors wait easily.
    3. The next step is distributing the weights of factors to different levels of suitability, you can use equal interval ranging technique. For example, if one of your factor has a weight of 32 and if you have four levels of suitability; then the most suitable class will get 32, the next level of suitability will get 24, then next level of suitability will get 16 and the last one will have 8.
    4. The last step is overlay analysis of reclassified factor maps.
    My advice is this can be easily done by ArcGIS model builder, the model builder will give a chance to see the sensitivity of weighting.

    Refer this:


  • Suggested longitudinal data analysis method for smaller sample size?

    Hi all,

    I am doing a longitudinal study with two waves of data, and I have a sample size of around 100. With these data, I hope to examine:

    1) the direction of causality of IV and DV 

    2) how IVs and DVs change over a short period of time.

    I am aware the sample size is quite small for a longitudinal study, and SEM cannot be used, so I am wondering if anyone can recommend a suitable way to analyse my data. Thanks a lot! 

    Eddie Seva See · Bicol University

    Longitudinal survey designs are designs that assess subjects on two or more occasions with the same or similar instrument. They examine stability, development, or change in the subjects across a span of time.

    Change or stability can be measured by getting the difference of the variables' means (for ratio/interval measures) between time 1 and time 2, and the difference in frequencies (for nominal measures)  of the variables between time and time 2. If your sample is probability you can proceed to Z test of difference between sample (paired or independent).

    There could be different kinds of samples.

    Panel design. It is a design where data are collected at different point in time from the same subjects (called panel).

    Trend design. It is a design where a new sample is drawn at each measurement period to keep up with changes that may have occurred in the general population.

    Cohort design. It is a variation in trend design in which specific subpopulations, or cohorts, are examined as they change overtime. A cohort is a group of people that have a certain characteristic in common, such as being born in the 1950, graduating from college in 2005, or marrying between 1990 and 2000. The same population is involved throughout the research but a fresh sample is selected every time data are gathered.

    Could you please elaborate on what you mean by direction of causality?

    I hope this helps.

  • Ernie Prokopchuk added an answer in Nitrate:
    Which is the correct resonance form of Nitrate ion?

    I attach the a file containing two sets of resonance structures. Can you please identify which is the correct resonance form of Nitrate ion?

    Ernie Prokopchuk · Yukon College

    It seems to me that Anga's answer and your option II are the same sets of resonance structures and are probably the preferred structures.

  • Garth Owen Watson asked a question in Genome Size:
    Any ideas on methanogen gene copy number for qPCR setup calculations?

    When setting up a protocol for methanogen qPCR, I need to know the genome size and copy number. My questions are 1) Is it appropriate to use E.coli for genome size since I am interested in all methanogens that I am likely to find in an environmental sample? and, 2) I am wondering whether the actual copy number of the methanogen gene is variable across taxa or if I can assume this is simply one gene per genome. I haven't chosen the primer set yet but hoping that the gene it targets should only occur once per cell. Therefore I would be using the values - Genome size = 4.6Mb and copy number = 1.

    I am following this protocol from Applied Biosciences

  • Muhammad Farhan asked a question in Laser:
    Mirror setup for 2-axis CNC machining (DMLS)?

    I am aware of two setups which are common in laser-based machines for 2 axis operations:

    1. Use two separate lasers

    2. Mount laser on a moving arm with a third mirror moving perpendicular to laser (similar to buildyourcnc.com setup)

    I want to know if there is any method of setting up mirrors in a way that I can achieve two axis operation with a single laser, within a CNC environment.

  • Can somebody provide me the softcopy of the following paper?

    Pores as fracture origins in ceramics by Roy W. Rice published in the Journal of Materials Science March 1984, Volume 19, Issue 3, pp 895-914

    Abdur-Rasheed Alao · James Cook University

    Hi Hawa,

    Thank you so much for the sent paper. This gesture of yours has made my day.



  • Daniel Crowley added an answer in DNA Cloning:
    Suggestions on cloning 2kb gene using Life's pET TOPO 100 kit?

    I'm having difficulty cloning a 2kb gene into life's TOP 10 cells using their pET TOPO 100 kit. I hope to express these proteins, but am not at that step yet. I am new to cloning and appreciate any advice. 

    This was part of a procedure in which I was cloning 3 PCR amplified genes (sizes 400bp, 900bp, and 2kb)

    The two smaller genes worked well. I had a similar amount of PCR product for all three genes (amplified using a proofreading polymerase-makes blunt end products), diluted them appropriately to obtain the recommended molar ratio of PCR product to plasmid gene, incubated them for 10 minutes with the linear plasmid, then inserted them into TOP 10 cells. 

    The smaller genes resulted in numerous colonies that were confirmed to have the gene insert by PCR and RE digest. The larger 2kb product resulted in fewer colonies, 20-30, and RE digest and PCR showed that 7/8 colonies tested had no insert (it appears as if the plasmid was not linear, but had ligated to itself) and that 1/8 of the tested colonies potentially had the insert, but it looked as if it had been cloned in the wrong direction.

    I repeated the PCR of the 2 KB product to obtain a stronger PCR product, then cleaned it using zymo's clean and concentrator kit. I had a strong band by electrophoresis with no primer dimers, extra bands, etc. 

    This time I increased the PCR product/plasmid reaction time from 10 minutes to 30 minutes (per Life's recommendations). However, this time I have NO colonies. 

    Any suggestions on how to move forward from here?

    1. I have no reason to think this protein is toxic, but little is known about it. 

    2. I did not run a positive control, however the smaller genes worked so does this negate the need for a positive control? 

    Anyways, hope this makes sense I'm new to posting in forums and hope I provided all the needed information. 

    Daniel Crowley · Occidental College

    Thanks for everyone's suggestions. I did solve the problem, in case anyone ever looks at this forum for answers I'll finish it off. 

    Larger PCR inserts have a lower ligation rate. Life's protocol acknowledges this and has you increase your insert concentration/total amount of PCR product, thus increasing the molar ratio of insert:vector.  Their costumer service represented repeated this when I called for advice. 

    To test this I increased the molar ratio of insert to vector, starting at their recommendation of 1:1 and going up to 500:1. It wasn't until I got to 250:1 or so that I started to get a lot of positive colonies, even then most of my vectors were still self annealing. I did have some that worked with the insert though.

    So moral of the story: by ignoring the protocol and technical support scientist I  drastically increased the molar ratio of PCR insert to vector for the large 2kb insert and got great results. Don't think I invented the wheel here, many people seem to do this who have a lot of experience cloning. 

  • Alexandra Simmons asked a question in GATE:
    How do i remove a paper I accidentally uploaded?

    Instead of sending a paper privately, I accidentally uploaded it to research gate. I wish to remove it. I don't know how. Please help.

  • How do I perform discriminant analysis with 16 dependent variables?

    Discriminant analysis on SPSS is limited to 12 dependent variables. However, I need 16 for a study I am conducting. Does anyone have a work-around for this or know of a package that can analyse 16 dichotomous variables?

    Anna Bartkowiak · University of Wroclaw


    I think that you are concerned   de facto  with one variable which may appear in K=16 categories. You have a sample of n data vectors given as a data matrix X of size nxd, where n stands for number of rows (say, samples of wine), and d for number of columns (say, some chemical attributes characterizing the given wine samples). Generally, the wine samples were recorded in K locations.

    You would like  to construct an algorithm which could predict -- for a given  sample of wine -- in which location  this wine sample  was produced.

    This is a typical problem which may be solved easily by ANN, Artificial Neural Networks, in particular by Multilayer Perceptron (MLP) with one hidden layer, d inputs and K outputs. You will obtain some scores expressing probabilities that a given data sample was produced in each of the assumed K locations.

    There is a splendid package NETLAB written by Ian Nabney in Matlab. The package is free and can be downloaded from the author's homepage. Of course, you need license for the basic version of Matlab (certainly, your University has such licence, it is not free, however - without all the toolboxes - Matlab is not so much expensive).  Working with NETLAB you are not limited to 12 or 20 categories/classes, however, as was mentioned above, with larger number of classes also a larger data sample is needed. There is also a book by Ian Nabney: NETLAB, Algorithms for Pattern Recognition  or another book by C.M. Bishop: Neural Networks for Pattern Recognition explaining the foundations and building strict mathematical models.

     You will have much fun working with MLP. 


  • Bhuwan Chhetri asked a question in Plant Extracts:
    My plant isolate does not dissolve in anything?

    Hi, I have a plant extract fraction that I want to dissolve in a solvent. Tried all solvents possible from Hexane, benzene to DMSO and water. Did not dissolve in anything. Any suggestions?

  • Muhammad Farhan asked a question in Pro-E:
    What are the benefits of working in assembly/ part environments in SolidWorks?

    I have recently switched from Creo (formerly Pro/E) to SolidWorks. I have learnt that in SolidWorks, I can work on an assembly in part mode and then convert it to separate part files through "Insert > Features > Save Bodies". Hence, I am building a assembly within a part mode. 

    Second mode, which is the most common mode in any parametric software, is assembly mode. Where you import different part files, define relations and build an assembly. 

    I want an expert opinion on the advantages and disadvantages of both techniques before I continue to build complex machinery models and suffer consequences at a later stage.

    I usually use Solid CAD tools along with Sheet Metal Design in SolidWorks 2015.

  • Siyamak Sarabi added an answer in Microgrids:
    Which software is the best for the shape design in papers?

    As you know and see in electrical papers such as IEEE or SD, there are many shapes for demonstration of the concepts at papers. I want to know that often which design softwares are used for drawing shape in papers except Visio? For example I've attached a shape in microgrid area.

    Siyamak Sarabi · Ecole Nationale Supérieure d'Arts et Métiers


    Edraw is also useful. Also Xmind for diagram and chart designing.

    In Edraw you have different clip arts that you can easily select and use them in your design. Even the electrical circuit elements are available .

    download link: http://p30download.com/fa/entry/1670/ 

    I hope it would be helpful for you.

    Good job and lucky

  • Maykel Manawan added an answer in Thiourea:
    Why do we not see any peak in the XRD pattern of iron sulfide on increasing concentration of thiourea?

    I synthesized iron sulfide nanoparticles using thiourea but when i increase the amount of thiourea, i observe no peak in  XRD pattern corresponding to iron sulfide. Please help or you can attach related text.

    Maykel Manawan · University of Indonesia

    Please attach ur file

  • Which fitting function is better for determining the crystallite size from XRD pattern: pearson VII or pseudoVoigt?

    Using psdvoigt in origin 9.0, I obtain two different FWHM parameters (wG and wL). Which one of these should I use for determinating the crystallite size using Scherrer equation? thank you

    Maykel Manawan · University of Indonesia

    Martin, why use Origin instead of XRD software?

    Crystallite size lie on Lorentzian broadening, strain lie on Gaussian broadening.

    Did u use the standard sample to get the instrument information?

    For powder sample u must use all the peaks up to higher 2theta.

    Even if powder and use WH-plot (size-strain analysis) u still can end up with 5-10% deviation if ur powder statistic is not good enough, or u had anisotropic shape or preferred orientation.

  • Thomas J. Scheff asked a question in Websites:
    Can you upload the hundred articles and notes on my website?

    http://www.soc.ucsb.edu/faculty/scheff/     Many of the requests for uploads are there.