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
  • What is the basic papers/data sets in Brain Function Analysis?

    Hi, I wanna start a new research for developing machine learning methods for Brain Function Analysis, especially for analyzing the cortex of Human Vision. Would you please help me to find some significant papers and fMRI data sets, which are related to mentioned subject? 

  • Can you suggest a method for agar analysis?

    My recent studies showed that the presence of some protein hydrolysate (e.g. yeast extract) in agar plate will inhibit the development of mosquito embryo.   The inhibitory effect on embryo development is not due to the protein hydrolysate alone, since the protein hydrolysate have to be mixed with the agar and subject to autoclave to exhibit the inhibitory effect.   This suggest that some interaction occurs in between the protein hydrolysate and agar.   Therefore, I would like to know is there anyway to analyze the constitute of agar? (a polysaccharide?)      

    Patrick Druggan · Synergy Health, Chorley, United Kingdom

    Yeast extract contains a high concentration of riboflavin. This could be acting as a photosensitizer and forming free radicals. It could also be that you have formed Maillard reaction products during autoclaving,that might inhibit the growth of the embryo. I'd suggest filter sterilising the yeast extract and adding that to the molten sterile agar. 

  • Fernando Testa added an answer in Political Culture:
    Is it required to know Argentine Culture and Latinoamerican Theology to understand Pope Francis' teaching and ministry?

    Perhaps Pope Francis could be enough understood as a sensible Jesuit in dialogue with up-to-date global social, economical, political and cultural happenings.

    Fernando Testa · Centro Universitário Ítalo-brasileiro - Uniítalo

    If one happens to be Argentinian, South American, a connoisseur of south american theology (specially liberation theology) or know Francis' personal history, this knowledge will certainly help him to understand his speeches and style better. But if someone completely lacks this knowledge, it's clear that it is still possible to understand him to some extent. So, I wouldn't say "required", for it would suggest is impossible to understand him at all  – which obviously cannot be true.

  • Brain scans of severely depressed people show reduction of of grey matter in various areas of the brain but when does this degeneration begin?

    Brain scans of severely depressed patients show reduction in grey matter volume in a number of areas of the brain associated with regulation of mood and cognition.

    But what comes first? Is it the slow pre- depression build up of increasingly negative thinking that precipitates these reductions to the point where specific brain systems regulating mood and cognition suddenly fail to the point which tips the person into severe depression and then begin to degenerate further thus underpinning the illness?

    Edward E. Stambaugh II, Ph.D. · Family Medicine Associates, Broomfield, CO

    One of the most promising current hypotheses is the inflammation approach which sees depression as an inflammatory process that involves the brain in its entirety  as cytokines lay down inflammation markers that initiate the destruction of healthy neurons.

  • Mila Pravda added an answer in Biosensors:
    Biosensors: cleaning the analite so the biosensor can be used again. If we are detecting a bacteria, is it absurd to use an antibiotic as a cleaner?

    It can't affect the immobilized antibodies.I thought of using Ag nanoparticles, but this may clutter the device by adsobing to the walls.Is there other bactericidal solutions, something I could use to rinse the bacteria, without affecting the immobilized molecules?

    Mila Pravda · University College Cork

    It won't work, but keep thinking. Your ideas may once change the world. Antibacterial action generally falls within one of four mechanisms, three of which involve the inhibition or regulation of enzymes involved in cell wall biosynthesis, nucleic acid metabolism and repair, or protein synthesis, respectively. The fourth mechanism involves the disruption of membrane structure. 

  • Kenneth M Towe added an answer in Gas:
    Are there cost-effective ways of capturing and harvesting 'biogenic' combustible gases from seeps in the seafloor?

    In the current 'climate change' syndrome, we are constantly looking for ways of ridding the atmosphere of accumulating radiative gases (so-called 'greenhouse gases, GHGs': H2O, CO2, and CH4). Over the last 3 decades, we have found thousands of locations in the seafloor, where one of the strongest GHGs is escaping, namely methane, CH4. These are active gas vents, or seeps, which are easily tracked acoustically, their manifestations known as mid-water gas plumes, or just 'flares'. I have recently found a way of harvesting such gas seepage, with a device (or system) called SUMECO: "submarine methane collector" (see my latest written contribution, in my profile). I belive this to be a viable and cost-effective way of harvesting methane from the seafloor, for use as a resource.

  • Abdallah M. Albeltagy added an answer in Atomic:
    Is the amount of energy converted from an amount of mass depending on the kind of the element itself ?

    As we know the amount of energy converted from an element depend on the binding energy o of this element, and this amount is different from element to another .

    Abdallah M. Albeltagy · Plant Protection Research Institute (PPRI)

    As we know the amount of energy converted from an element depend on the binding energy  of this element, and this amount is different from element to another

  • Belhamiti Omar added an answer in Epidemics:
    What type of boundary conditions are necessary to be imposed for epidemic model?

    How we choose  boundary and initial conditions  for spatial-temporal  epidemic model.

    Belhamiti Omar · Université Abdelhamid Ibn Badis Mostaganem

    Thanks for your answer, the epidemic in question is Dengue and the model used SEIR for the human and SEI for the mosquitos.

  • Alexander Tolstov added an answer in Polymerization:
    What is the best polymeric film in the market to hot press your polymeric samples in between (no adhesion, no contamination, high thermal stability) ?

    I know that one choice might be Teflon (PTFE or PFA) , but they have severe delamination that contaminates your sample.

    Alexander Tolstov · National Academy of Sciences of Ukraine

    I have used Kapton polyimide film and PTFE composite tape with surface lamination (there are variety of products). But if you use antiadhesive film in few hot press cycles at temperature above you need the effect contamination should be excepted. PET is also good choice but for lower temperatures than PI and PTFE. Good luck

  • Doug A King added an answer in Telemetry Systems:
    Is there any correlation and validation of the X2 Biosystems XPatch with the HITS?

    I'm using the XPatch from X2 Biosystems and am looking for validation studies and comparison with the Head Impact Telemetry System HITS).

    Doug A King · Hutt Valley DHB

    Thanks - have that article and the one published in the Clin J Sports Med. I have a paper about to be published using the XGuard - just need validation studies for the XPatch

  • Erick Messler added an answer in Alcohol Abuse:
    What are the best predictors of alcohol relapse following treatment?

    Thanks in advance for your replies.

    Erick Messler · Wilford Hall Ambulatory Surgery Center

    Gentlemen, thank you for your responses. I am tasked with selecting pre- and post-measures for an intensive outpatient alcohol treatment program. I'd like to know whether our treatment program affects factors associated with relapse, and eventually, whether these factors are associated with relapse several years post-treatment with our population (active duty military). So, specifically, I am interested in modifiable factors that predict relapse. Thank you!

  • How do bacteria develop multi-drug resistance?

    Methicilin-resistant S. aureus were originally resistant to Methicilin but later on develop resistance to many other antibiotics. Similarly, vancomycin resistant Enterococci (VRE) also develop multi-drug resistance.  Why it is so often that bacteria develop multiple resistance? How do they acquire the multiple resistance? 

    Abdolmajid Ghasemian · Tarbiat Modares University

    several ways include: mutations in the bacterial chromosome, acquiring of genetic extra-chromosomals such as plasmids, integrons, IS elements, Transposons and Bacteriophages. for MRSA isolates, entry of SCCmec types is a great reason for this. moreover selective pressure from antibiotics causes several mutations in genome. 

  • Jan Štefka added an answer in Illumina:
    Any experience with amplicon sequencing of MHC loci on Illumina?
    We are trying to decide between Illumina and 454 technologies for a MHC genotyping project in a bird species (class II B exon2). After running a preliminary run on Roche Junior and carefully filtering out artefacts, we found we need a very large sequencing depth to saturate the variability of alleles in each individual (up to tens of alleles). For the full experiment of genotyping 200+ individuals I would prefer MiSeq over Titanium given the price tag. But amplicon sequencing may get tricky there (low complexity problem) and I heard about huge headaches when analysing such MHC data from Illumina. The only related discussion I found on RG is this:
    https://www.researchgate.net/post/Are_there_any_strategies_for_sequencing_a_polymorphic_locus_eg_MHC_without_using_cloning
    But it does not quite address the problem.
    Jan Štefka · Biology Centre, ASCR

    Hi Franziska,

    we decided for IonTorrent and already processed the data, but we're switching to MiSeq with our next MHC project too. The Iontorrent was definitely workable and much more cost effective than 454, but suffered relatively high error rates. Thanks for the reference, I've seen a few Illumina MHC papers recently, not this one though. Best, Jan.

  • Marc Tessera added an answer in Cognitive Systems:
    Is Chalmers' so-called "hard problem" in consciousness real?

    In his 2014 book "Consciousness and the Brain: Deciphering How the Brain Codes Our Thoughts" Stanislas Dehaene wrote "Chalmers, a philosopher of the University of Arizona, is famous for introducing a distinction between the easy and the hard problems. The easy problem of consciousness, he argues, consists in explaining the many functions of the brain: how do we recognize a face, a word, or a landscape? How do we extract information form the senses and use it to guide our behavior? How do we generate sentences to describe what we feel?

    “Although all these questions are associated with consciousness,” Chalmers argues, “they all concern the objective mechanisms of the cognitive system, and consequently, we have every reason to expect that continued work in cognitive psychology and neuroscience will answer them. By contrast the hard problem is the “question of how physical processes in the brain give rise to subjective experience … the way things feel for the subject. When we see for example, we experience visual sensations, such as that of vivid blue. Or think of the ineffable sound of a distant oboe, the agony of an intense pain, the sparkle of happiness or the meditative quality of a moment lost in thought … It is these phenomena that poses the real mystery of the mind”."

    Stanislas Dehaene's opinion is "that Chalmers swapped the labels: it is the “easy” problem that is hard, while the “hard” problem just seems hard because it engages ill-defined intuitions. Once our intuition is educated by cognitive neuroscience and computer simulations, Chalmers’ “hard problem” will evaporate".

    Personally, I agree with Stanislas Dehaene's opinion.

    Louis,

    Generally speaking, I may understand you point of view.

    However, with regard to my case I disagree that an aesthetic philosophical consideration was at stake.  

    Indeed, I don't reject a supposed boundary between non-life and life . My claim is merely that the concept of 'life' per se is not scientific and thus irrelevant in the search for the origin of the terrestrial organisms.  

    How do you argue your assertion?  

  • Who can use software that generates maximally disordered sequences on the integers?

    I have taken effort to produce such software and am seeking persons who have suitable application for such sequences.  Currently, the software will compute shustrings on the integers and the nucleotides but will generate maximally (or uniformly) disordered sequences only on the integers; the nucleotides is coming, as is binary and a user selectable symbol set.  For now, understanding the application areas for such sequences, and the provision of same to interested parties, with the hope that users will provide feedback, is solicited.

    This software generates sequences in integral powers of ten, up to length one hundred million digits.  A sequence of one hundred million digits takes just 30 seconds to produce.

    William R. Buckley · California Evolution Institute

    Shuffling allows for mixing of shustrings at any position, while the iterative search through the allowable permutations restricts mixing to the right end of the sequence.  The shuffle operator is the last operator to be implemented in software; earlier I give examples of use.

  • Does 'Perceived Freedom' contribute in Subjective Well-being ?

    Hi Friends, 

    I am interested to know, role of  'Perceived Freedom' in development of Subjective Well-being of Youth. Usually, perceived freedom is being used as part of leisure theory that is actually "perceived freedom in leisure'. But I am interested in its real context i.e. 'perception of individual freedom' of the young people. Can anybody help..........? 

    Muhammad Saleem · The Islamia University of Bahawalpur

    Thanks Dear David Milford

    I do agree with your thought, but few variations are reported by researchers and youth by itself that they are different in terms of freedom from their older generations. Current Youth is more concerned with social satisfaction than gen-X and so...

    Secondly, increasing rate of truancy tell us they are not feeling contentment with this kind of life style. Similarly, rate of court marriages, and honor killing in Pakistan also provide food for thought. 

    Comment plz. 

  • Hakan Boz asked a question in Galvanic Skin Response:
    Measuring Pleasantness / Unpleasantness together with Galvanic Skin Response and Heart Rate Variability?

    Hi dear all!

    In our study we are showing the participants (as potential customers) various types of advertisements and recording their response (microsiemens values) simultaneously thorough Hrv and Electrodermal Activity. I am curious to find out what the microsiemens values would be for instance when the participants like or dislike the ad? In other words would the microsiemens values increase or decrease and how in these emotional states (of like / dislike)? How would we be able to determine like or dislike by looking at microsiemens values? I would be happy if you could provide info about the above.

  • Why does the blocking temperature of superparamagnets decrease with increasing magnetic field (at a constant AC frequency)?

    If the applied field is pinning the particles then their relaxation should be slow and thus the blocking temperature should increase. But I guess this is not the correct way to look at it as this gives a complete contradictory picture to the established one.

    Daniel Baldomir · University of Santiago de Compostela

        What Irene has said is true with respect to the height of the barrier of the potential associated to the supermomentum of the particle under a reversal magnetic field, but there are more subtleties besides the magnetic field that we have tried to study in a simple form in the paper that attach you. I recommend you to have a look to my contributions in research gate because I have others which could be more specific and applied.
     

  • Taras Vitak asked a question in Anti-Aging:
    Did anybody do western blotting of globin?

    I need to do western blot of RBC globin but i can't find how to extract globin from the cells. I will use anti-AGE antibody. Did somebody do something like that? Thank everybody for answers!

  • Patrick Druggan added an answer in Autoclave:
    Is there a way to lessen then likeihood of our autoclaved trash bags exploding under the pressure?

    Some of the materials that we autoclave have a higher salt concentration, as they are used in a microbiology lab. We have tried sticking the autoclaves temperature probe in a beaker of tap water, as tap water has more salt particles and ions than ddH2O. We have also tried double bagging the trash and leaving a two finger wide opening in the rubber band sealed bags, so there is not too much pressure building inside the bag. We also run the trash cycle as a liquid cycle at 121 degrees for 25 minutes. A major percentage of these bags still end up exploding melted agar and LB onto the inside walls of the autoclave, which is a pain to clean. Has anyone else here had a similar issue that they found a solution to or should I just expect that some bags of trash are going to explode no matter what you do to prevent it? 

    Patrick Druggan · Synergy Health, Chorley, United Kingdom

    I'm not sure why the salt concentration is affecting this. Can you explain a little more?

  • Muath Najjar asked a question in Traffic Engineering:
    What is the innovations in traffic data collection and analysis?

    As all of us know that data is a very important while dealing with traffic engineering


     What is the innovations in traffic data collection and analysis?

  • Abdolmajid Ghasemian added an answer in DNA:
    Why sometime after DNA extraction there is no band in electrophoresis?

    I extracted DNA from bacteria by using extraction Kit, by when I run the DNA on agarose gel no DNA band detected, but when I did the PCR reaction I got good result. And when I run it on agarose gel I got good bands?

    Abdolmajid Ghasemian · Tarbiat Modares University

    Sometimes the amount of DNA template in whole cells is very scant and you cannot see in electrophoresis, but the PCR is sensitive enough to amplify the very low amount of DNA template. 

  • Does anyone have ideas on how to improve the sensitivity of the drugs with high LOD's and LOQ's?

    I am working on quantifying about 10 drugs in plasma using UPLC - MS. The Limit of Detection and Limit of Quantification of some of the drugs specifically (Amlodipine) are very high as compared to the others. Any ideas on how to improve the sensitivity of the drugs with high LOD's and LOQ's?

    Patrick Druggan · Synergy Health, Chorley, United Kingdom

    I think you are using the wrong detector. I think you would get better results with a UV-Vis diode array, rather than MS. 

  • How can I get localized vibration characteristics of a structure from an accelerometer sensor?

    Can we get the localized characteristics of a structure from accelerometer data?

    I mean FRF and other parameters that give global characteristics of a structure.

    I think the accelerometer data contains both the local and global vibration characteristics of a structure.

    How can I get the localized information to the default localization of a structure?

    Sebastià Vicenç Amengual Garí · Hochschule für Musik Detmold

    I am not sure if I understand your question correctly. If what you want is to get only local information about the vibrational characteristics of a structure, when you use an accelerometer you are doing this. In other words, the accelerometer will give only information about the point in which it is located. Of course, this vibration depend on the global behaviour of the structure and its vibrational modes, but the signal received from the accelerometer will correspond strictly to that specific point.

    Moreover, the global vibration characteristics and modal analysis of the bridge cannot be extracted from a single point measurement. In order to get the vibrational characteristics of the whole structure you will need to scan the structure at several points and generate a model from that measurements.

  • Patrick Druggan added an answer in Scattering:
    An alternative for scatter plot?

    Are there any other ways than scatter plot to visually represent the relationship between x and y?


    Thanking you,
    Irshad

    Patrick Druggan · Synergy Health, Chorley, United Kingdom

    What are you trying to show?

  • Ofer Dekel added an answer in Celebrity:
    Could anyone refer me to literature on fan cults/culture for a research on the relationship between youtube celebrity and their fans?

    We would like to de-construct the fans' comments and learn about the nature of these relationship

    Ofer Dekel · Sheffield Hallam University

    Thank you Lars

    this is so helpful

  • Tamara Heredia added an answer in Keratinocytes:
    If I have cultured keratinocytes expressing only K14 gene, is it possible that under certain conditions, they become activated and express K16?

    If I have cultured keratinocytes expressing only K14, treated with IL-1ß, is possible that they become activated and therefore they express K16?

    That happens in basal keratinocytes, but I am not sure if "cells that express only K14 gene" means that all the other genes are not there, or they are just inhibited and eventually they could be activated.

    Tamara Heredia · University of Leipzig

    Thank you for answering. But in case of K14, if I have cultured cells only with K14 gene, then is it possible that treatment with IL-1ß induce the activation of cells and afterwards, they express K16??? is that possible?? Or knock out keratinocytes, (lack all keratins) is possible that they become activated and express some gene with IL-1ß treatment??

  • Has anyone collected blood to get serum for CH50 assay?

    For me, I put the blood tube on ice immediately after drawing with a few times of turning up and down. After about 2h, centrifuge blood at 2000g, zero degree for 10min. But afterwards I always have gel-like things inside the tube.Did anyone have similar problems? How to solve this problem?

    Patrick Druggan · Synergy Health, Chorley, United Kingdom

    Shengye, it sound like you have formed a fibrin clot. Serum has no clotting factors in it. I am no expert, but it would seem that you either need to remove the fibrin clot - glass beads or sterile sand might work to form the clot - or allow the clot to contract expelling the serum.