Q&A

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  • Selva Chemist (Bio) added an answer in DMSO:
    How does solvent affect on the molecular weight of polymer?

    " Between DMSO, DMAC & NMP solvent." I cant understand it even with polarity !

    Selva Chemist (Bio) · GreyMatterResearch Foundation, India

    Dear Bahareh Razavi ,

    I Don't know which type of polymer you are using either cross-linked resin or some other,

    Anyway answer for your question is, Polar solvent means resin get swell more and also in some case non-polar also get swell more that based on the polymer functional group.,

    Polymer have high capacity functional group that means high % of functional group means from this H+ or OH- loss will be more and the solvent functional group Pyrolidone Group from NMP, DMSO group effect will alter the molecular weight its quiet common with polar solvent,, so molecular weight difference will occur.,

    Due to Weak  bond between functional group of the polymer or weak cross-linking some will be there due to polar solvent addition.

    Due to more solvent absorption, some internal bonding and alteration you feel molecular weight affect., 

    This are the reason for your problem but its minor,

    Hope you got.,

    Good Luck & Regards

    R.Selva........

  • What is the use of Principal component analysis (PCA) in ecological health assessment of a body of water, and how can it be used?

    I am working on project "Ecological health assessment of lake". and I could not understand the PCA.

    Chin Yik Lin · Universiti Malaysia Sabah (UMS)

    Dear Saurabh,

    How many sampling sites do you have? Bear in mind that PCA requires at least 200 observations/samples for its results to be statistically valid. But sometimes 100 samples are also acceptable. If you do not have sufficient amount of data as mentioned, I would like to suggest you to run a cluster analysis. Then, only you may try to run PCA and see both results give you reasonable output.

    Maybe this paper might be useful to you. I hope this help. Good luck.

  • Mingqing Wang added an answer in Digital Holography:
    How can I reconstruct a clear image plane digital hologram?

    As far as I know, the angular spectrum method is a good idea, but I cannot get a clear reconstructed image. Could you give me some advice?

    Mingqing Wang · Beijing University of Aeronautics and Astronautics (Beihang University)

    Dear Tatiana Latychevskaia

    Yes, you are right. I am using plane waves.My hologram is off-axis, wavelength is 671 nm, and the distance is decide by the lense, the length of object  is 1.5 centimeter and the width is 1 centimeter. Could you give me some advice? Thank you in advance!

  • Grant M Harris added an answer in Camera Trapping:
    Software for processing and collating camera trapping photos?

    Hi everyone,

    We are about to start processing photos from a camera trapping study. There are many many thousands of photos and I cant help but think there must be some neat programs out there to speed up or automate the process. So far, 'Camera Base' (CamBase) appears to be the wildlife ecologists' tool of choice. Anyone out there have any other recommendations?

    UPDATE: The identification of species will be done by eye (human). What I am looking for is  suggestions of programs that would facilitate the process of going through many photos and that would generate a database based on our identification.

    Thanks a lot!

    Chris

    Grant M Harris · U.S. Fish and Wildlife Service

    Hi Chris: As M. Butler wrote, a method pioneered by J. Sanderson has the following steps A) automatic renaming of images by date and time that the image was taken B) the user sorts camera trap images into a standardized file structure based on species names and # observed in the image and B) a set of programs analyzes this structure to make a text file describing species observed, location and time, plus a number of summary metrics. A number of Federal lands in the SW USA, and projects globally have been using this method successfully. It's been a huge time saver (especially for making occupancy matrices), and facilitates meta-analyses (by sharing and analyzing the text files, not the images themselves). We've tried to remove as much human input as possible (to reduce error), though the drag and drop does take time. To our knowledge, there are no automatic methods to identify species or # of them yet from such imagery.  We've been handling millions of images this way.  Literally - one site we analyzed had > 2 million images.

    References include: Publication - http://www.esajournals.org/doi/full/10.1890/0012-9623-91.3.352
    Publication- http://www.smallcats.org/files/Sanderson_Harris2013.pdf
    New book - http://www.publish.csiro.au/nid/18/pid/7150.htm
    Programs and further material: http://www.smallcats.org/CTA-executables.html
    Hope you find this useful.

    Grant

  • Mojtaba Akhtari asked a question in Splenomegaly:
    Is any role for splenectomy before allogeneic hematopoietic stem cell transplantation in patients with chronic myelomonocytic leukemia (CMML)?

    Is there any role for elective splenectomy before allogeneic hematopoietic stem cell transplantation in patients with CMML who have massive splenomegaly?

  • Dr A. Kumar added an answer in Photo:
    How can i measure the lifetime of photoexcited carriers from Open Circuit Photovoltage decay anaysis ?

    How can i calculate the life time of electrons and holes generated from photo excitation of oxide based semi conductors with the help of open circuit photovoltage decay analysis. ?

         
    Dr A. Kumar · Harcourt Butler Technological Institute

    Life time of photo generated charge carriers can be calculated from the time dependence of photovotage when light is switched off. For a trap free semiconductor it is an exponen

  • How could i remove my neuronal cultue cell from coverslip for performing electrophysiology ?

    During perfprmance of electrophysilogy on nuronal primery culture cell that has attached to the coveslip i could not patch it well and seal the patch also to hold for long time to measure the current of the cell is there any way to remove the cell form coverslip without any damage of cell to culture media?

    Md Nazmul Haque Habib · Dongguk University

    Thanks all of you for your kind sugession and specially thanks to Elise Stanley for explanation the whole matter in details.........

  • Raid Amin added an answer in Statistical Programs:
    What is the best statistical program can be used for multivariate analysis?

    There are many statistical programs produced by software companies, enough to one should decide which software program is more fit to present and analyze the data. If we have data on ages of trees, size, growth rate, vitality, and seeds production. What is the best statistical program can be used for multivariate analysis for these parameters?

    Raid Amin · University of West Florida

    The Grateful Paul! 

  • Aditi Narsale added an answer in NCBI BLAST:
    When I blast a primer sequence is shows up as retro - Actb on the UCSC blat tool. What does this mean? Can I use this fwd primer for PCR?

    NCBI blast tool does not identify the primer at all.

    Aditi Narsale · San Diego BioMedical Research Institute, SDBRI

    Thanks for the feedback!! It is a good primer indeed!

  • Chin Yik Lin added an answer in Water Harvest:
    Does anybody have any experience or knowledge about quality of water harvested from air?

    I have harvested water from air and measured by YSI device some water quality parameters (pH, TDS, DO and Salinity etc.) under the home condition. At the 20.1°C temperature, pH=7.26, TDS= 88.40 ppm, Salinity=0.06 ppb, DO=4.1 ppm like that.

    Air humidity is very important for semi-dry and dry ecosystem in terms of living organism especially for plants. So, by determining quality of water in the air may be we will open new gates in different ecosystem in terms of plant health.

    Chin Yik Lin · Universiti Malaysia Sabah (UMS)

    Dear Ugur Kezik,

    Im interested in your study. May I know what technique did you use to harvest the water? Is it a real time measurement technique? Bear in mind that possible contamination and chemical changes may occur when you harvest the water. Thank you very much.

  • Viet Truong Xuan asked a question in Solr:
    Is there some tutorials by using Solr for indexing binary files inside Cloudera?

    Dear all,

    I'm trying Cloudera Search, the Solr is alrealy integrated inside. So, the configurations of using solrconfig.xml and schema.xml are quite different with the 'pore' Solr. Is there some helps?

    Thanks,

    Viet

  • What (recent) accounts on language evolution would you identify as 'alternatives' outside of the nativist-v-emergentist dichotomy—if any?

    The pervasive polarization over the emergence and evolution of language—cf. nativism vs. emergentism—persists because it reflects a very relevant distinction at the core of language. So, this is hard question I'm asking but, if we were to identify alternative accounts falling a bit further from the large dichotomy—with a novel theory or method—, could you think of any? 

    Thank you

    Magnus Pharao Hansen · Brown University

    Marc Verhaegen: To even state that any single change in a trait "disproves" any evolutionary hypothesis about the environment of adaptation is so weird it makes my head spin. I cant even wrap my head around how decreasing importance of olfaction can possibly be considered decisive evidence for any hypothesis of human evolution whatsoever. Surely that could be compatible with any number of possible environmental niches.

    I have read some recent stuff about the AAT (including Philip Tobias endorsement), but really it strikes me as unconvincing in the extreme. It may look good in a simple dichotomy between savannah and waterside - but luckily hardly anyone in paleoanthropology thinks in such simplistic terms. Yes humans need to reside close to water. But it it a gigantic leap from that to deriving all other adaptations from that single fact. Much more so to propose that water provided the necessary pre-adaptations for language, in spite of the mountains of evidence demonstrating other factors being much more decisive in that process. 

    I may change my mind when your conference proceedings start getting cited in mainstream publications. I would be interested in reading Langdon. Johanson and Stanfords contributions, to hear their evaluations, but I cant find them online. Apart from them and a few others the line-up for the conference looks mostly like the longstanding AAT clique. Certainly not an event that looks like it would have caused a major paradigm shift. 

    Liljana, I also agree with your statement that all venues are useful. I dont have a problem with syntax at all, I just dont believe that a formalist perspective on syntax (generativist or otherwise) is likely to prove useful in understanding language evolution (because I dont believe syntax is evolutionary fixed). I may have misunderstood your general approach having only read your posts in this thread, if that is the case I apologize.  I will nonetheless look forward to reading your book which looks extremely interesting and certain to provide valuable insights. 

  • Mahmoud M Suhail added an answer in Boswellia:
    Is there a data base of supplements like Boswellia or Curcumin for pain?

    I am making a list of supplements that can help for inflammation. There are  many different kinds and they are produced differently. I need to find some that are organic and Constantin no dyes, or gluten. I want to learn how these ingredients work. I am trying to find good product to buys and to recommend to my friends. I have an autoimmune disease. Many people find supplements but how do you know they are produced good.?

  • Murat Karakus added an answer in Gauss:
    Is there any method better than Gauss Quadrature for numerical integration?

    For FEA, I am using GQ for calculation of the energy for each element though I am wondering if there is any other method which supersedes GQ?

    Murat Karakus · University of Adelaide

    Thank you for your comment, Belhamiti. I know Simpson's rule is more accurate than trapezoidal method but not sure if it can produces more precise results than Gauss.

  • Vitaly Voloshin added an answer in Universe:
    Will we ever meet our interstellar neighbours?

    Somewhere 'out there' in interstellar space are people like us, wondering if they are alone in the universe.

    Will we ever meet them to do the laws of physics prevent that ever happening?

    Vitaly Voloshin · Troy University

    The distance is so colossal that the life time of our civilization is not sufficient to cover it.  Unless something extraordinary will be discovered that resolves this contradiction. So my answer is NO.

  • How to estimate and isolate anticancerous drug from plant material?
    I would like to check the activity of a plant as an anticancerous drug but I am unaware of a method to do this - can anyone recommend a protocol?

    It's not really a drug, although what is anticancerous is that it effects the brain in a way that alters DNA production at a later stage. It's not as if we can treat metastatic cancers with tea alone, for instance.

  • What are the universal markers for pulses?

    universal markers as a tool of DNA Barcoding

    Blood type genes and regulatory proteins can be detected in a blood test.

    You tagged 'Universe' so I assume you're aware that pulses are located within the universe as waves in the space-time continuum, marked by dark matter ofc.

  • Xin ma added an answer in Tophat:
    How can I get uniquely mapped reads from Tophat(v2.0.12)?

    I am new to RNA-seq, Now I want to get unique alignment form the result of Tophat(v2.0.12), for example accepted_hits.bam that tophat produced. Who could help me? Thanks in advance!

    Xin ma · China Agricultural University

    Thanks above!

  • Marie Askholm added an answer in Chondrogenesis:
    What exactly is the effect of dexamethasone for differentiation of MSCs? and other supplements?

    I´m working on a project with 3-lineage differentiation of equine MSCs from adipose tissue and peripheral blood. I differentiate them towards catilage, bone and adipose tissue. In the following you can see the media and supplements I use.

    My question is what exatly is the effect of dexamethasone to the cells, since the supplements is used for all 3 lineages it cannot be for the differentiation towards a specific lineage. Also what is the excat effect of asorbic acid (it generally seems to be used in a much higher density in medias towards osteogenesis than towards chondrogenesis), beta-glycerophosphate, TGFbeta, insulin and IBMX, indometahcin.

    Or maybe you know a good place to find information about the exact effect of these supplements. Im very new i this field, so sorry if the question is a little stupid.  

    Osteogenesis
    Monolayer, DMEM-LG, FCS, 1% pen/strep,50 µg/ml gentamycin

    0,1 µM dexamethasone
    50 µM L-ascorbicacid-2-phosphate
    10 mM β-glycerophosphate

    Chondrogenesis 

    3D pellets, DMEM-HG, 10% FCS, 1% pen/strep,50 µg/ml gentamycin

    0,1 µM dexamethasone
    1 µM L-ascorbicacid-2-phosphate
    10 ng/ml TGFβ3

    Adipogenesis 

    Monolayer, DMEM-LG, 15% Rabbitserum, 1% pen/strep, 50 µg/ml gentamycin

    1 µM dexametason
    0,5 mM IBMX
    10 µg/ml rh insulin
    0,2 mM indomethacin

    all are stored in a incubator with 37 degree C, and 5 % CO2. 

    Marie Askholm · University of Copenhagen

    thank you all very much

  • Mahmoud M Suhail added an answer in Vasospasm:
    Who is interested in collaborating on how “Buerger’s Disease” or “Raynaud’s phenomenon” can be treated completely in just days?

    I have found how “Buerger’s Disease” or “Raynaud’s phenomenon” can be treated, just at some days completely and forever, and I think that this discovery (because of the remedy’s anti vasospasm effects) can be one of the most important discoveries in the science of medicine and numerous patients who suffer from diseases which are related to vasospasm will be able to find their healthy life again. But there are some problems for establishing the discovery worldwide, and I need supporters, collaboration or guidance of some professionals in the field. Who is interested in collaborating me for establishing it in scientific ways?
    Samad Esmaeilzadeh

  • Jack Payette added an answer in Marine Biology:
    How can I fix and preserve the jellyfish and at the same time maintain their colors?
    .
    Jack Payette · University of Massachusetts Boston

    I agree Alexis; I don't think Ethanol is a good option for this application but for other "hard-bodied" invertebrates like Arthropods, it makes sense I think.

  • Muhammad Arslan asked a question in Internal Standard:
    What is the procedure to quantify TPH in sediment samples using GC/FID? Urgent. Than you

    I would appreciate a detailed answer as I really need it urgently.

    Actually, I want to quantify Total Petroleum Hydrocarbon (TPH) from the foreshore sand (different stations with different source of organic pollution). I have tried to search previously asked questions as well as literature but have a few queries actually.

    1. Is it ok to air dry the foreshore sand and then follow soxhlet extraction? If no, what could be the best way not to lose some volatile compounds?

    2. After having chromatogram, how can I quantify the amount in each station? I guess internal standard will be used - but what could be the internal standard for TPH measurement? Please note i don;t want to measure any single specific compound like benzene etc.

    3. What formula should i use for the quantification?

    PS: I would be thankful if somebody provide me GC/FID profile details like injection temperature, gas flow, etc etc.

    Thanking you in anticipation.

  • Divaker Choubey added an answer in Transfection:
    How can I identify gene promoter (Cis-regulatory element)?

    I want to check if promoters of a few genes (from cattle) are active in the cells. I want to clone GFP under the promoters and transfect the cells with the vector. The problem is I don`t know the promoters. How can I identify the promoters. Would it be OK if I clone 200 – 300 bp of 5` untranscribed region assuming the promoters are there?

    Divaker Choubey · University of Cincinnati

    If you have sequence of 5'-regulatory region of a gene, check the sequence for the presence of "promoter region" cis elements using programs that are available from NCBI to predict a promoter region. This would a start. If it is predicted that the sequence contains "promoter region", next thing would be to test the sequence experimentally using an approach that you mentioned.

    I would use at least 2000 bp upstream sequence from the predicted transcriptional start site in the gene to test promoter region experimentally.

  • Divaker Choubey added an answer in Cell Line:
    Do cell confluence affect SaOS-2 cell´s drug sensitivity ?

    Hi, I'm currently working on mineralization of SaOS-2 cell line in the presence of my drug of interest. Previously the drug which showed effect on the mineralization ability of the SaOS-2 cell line is now showing no effect at all.

    Do the cell confluence alters SaOS-2 cell line drug sensitivity? Any one has earlier experience on this ? please share.

    Divaker Choubey · University of Cincinnati

    I agree with an earlier comment. Increase in cell density in culture is known to decrease sensitivity to a number of agents and increase cell survival. Therefore, it may be desirable to fix the concentration of compound of interest and vary cell density from 25% to 100% to assess the desired cell density.

  • Rachid Rouabhi added an answer in DMSO:
    Can I administrate DMSO intravenously in rats?

    Experiments are performed in rats, injecting DMSO through tail vein.

    I need to dissolve a very hydrophobic drug in DMSO for in vivo administration, but  this reactive is quite toxic. Is there any accurate protocol to perform this administration, or any other suitable solvent? 

    Thank you very much

    Rachid Rouabhi · Université de Tébessa

    Of course you can in condition to don't pass 100 ppm.

  • Dmitry Kovriguine asked a question in Propagation:
    How two identical KdV-solitons would be interacting?

    Let the KdV-equation be written in a standart form for u(x,t); solutions are related to a simple initial Cauchy problem: i.e., these propagate at the same direction x, the distance between them let initially be a.

  • What are the possibilties of antibacterial activity /ihibition vs antibiotic concentration revers correlations ?

    efficacy of drugs

    R.M. Udayangani Ratnayake · Rajarata University of Sri Lanka

    exactly ...thanks i will look in to solubility issue.. used spread plates for measuring colony growth

  • For object recognition in an image which is the best method?

    i am doing the project on object recognition based on image processing, can anyone suggest me which approach is best one, statistical or structural. and give me suggestions to implement this project  

  • Rachid Rouabhi asked a question in Hepatitis:
    What is the best method to dose the NADPH activity in hepatic cells?

    what is the best method to dose the NADPH activity in hepatic cells?