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  • Oscar Gonzalez added an answer in Hummingbirds:
    Does anyone know the long-term monitoring experiences and banding of hummingbirds in neotropical communities?

    We are currently initiating a monitoring program on mountain north of the Andes ecosystems, would be very important for us to know other implemented experiences and results that are of particular interest to account for future comparisons.

    Oscar Gonzalez

    Hi Aquiles; I did my dissertation on bird nectarivore networks in the central Andes of Peru from 2011 to 2014 and I am currently writing the papers on that. One group of researchers that can help you and I recommend become part of, is Hummingbird Monitoring Network (http://www.hummonnet.org/) they organize training sessions for researchers that want to learn how to monitor hummingbirds, mainly in the United States and Mexico. We organized one workshop in Cuzco, right after the Neotropical Ornithological Congress in 2011, they are eager to get contact with researchers from the neotropics. Espero haber ayudado, hasta pronto.

  • Agnes Machado asked a question in Absorbance:
    How to estimate the initial rates for the determination of kinetic parameters?

    Hello all,

    We have an enzyme that must follow Michaelis-Menten kinetics (we
    have an experimental way to avoid the inverse reaction), so we need to
    estimate initial rates at different initial substrate concentrations,
    then do the double reciprocal graph (Lineweaver-Burk).
    Raw data from a spectrophotometer is absorbance x time ; OK, we can
    relate absorbance to the amount of product formed.
    The question is: is there a formal , statistical way, to evaluate
    the point to which the rate is constant such that this one might be used
    to approximate the *initial rate*. Event better, I wonder of a software
    (very preferably free, even better if for linux) that might get the raw
    data (Abs x time) and apply the statistics to estimate the initial rate
    (we should have triplicates for several substrate concentrations - so,
    several curves). Our doubt here is, considering that though one has a
    good spectrophotometer, random oscillation might occur as in any
    experimental measurement and the inherent characteristic of such an
    experiment, id est, as the substrate concentration falls the rate falls
    (not necessarily in a linear way) as well.
    If such way is not available, I wonder how people have been
    estimating initial rate for abs x time.
    Thank you,


  • Tanya Procyshyn added an answer in Oxytocin:
    Does anyone know a lab that will test oxytocin levels in saliva?

    does anyone know a lab that will test oxytocin levels in saliva?

    Tanya Procyshyn

    Hi Kitkat - I'm at SFU in Vancouver and doing similar work measuring oxytocin in saliva.  I hope to do the assays here using the kits from Enzo. 

  • Céline E Riera added an answer in Cell Death:
    Can someone provide a protocol to induce resiniferatoxin-mediated TRPV1 neuron cell death in neonatal and adult mice?

    I am looking for a pharmacological alternative to ablate TRPV1 sensory nerves in mice. thank you for helping me if you have an established protocol.

    Céline E Riera

     Thank you Sam!

  • Cristiano Roussado added an answer in Microorganisms:
    How can I identify bacterial species in a mixed culture?

    I want to identify the bacterial species that have ability to degrade diesel range organics (DRO). I am planning to enrich microorganisms in a diesel oil medium for 1 week with mineral salts and diesel as carbon source. The biofilm attached to anode of microbial fuel cell that used to treat diesel contaminated waste-water will be scrapped into medium as the inoculum. 

    After the incubation period, I want to identify the bacterial species in the medium. What is the cheapest and easiest way to identify them?

  • Ahmad Al-Dissi asked a question in Veterinary Pathology:
    I am wondering if there is a well-established research protocol to induce prostate cancer in dogs and if there are good biomarkers?

    I am part of a multidisciplinary research group at the University of Saskatchewan Canada, who are studying prostate cancer. I am wondering if there is well established research protocol to induce prostate carcinoma in dogs. We need dogs with prostate carcinoma to use for imaging studies.

    Anybody who has a protocol or can help do this and would like to establish collaboration?

    Thanks very much

    Ahmad Al-Dissi

    BVetSc., MSc., PhD, Diplomate ACVP

    Assistant Professor
    Department of Veterinary Pathology
    Western College of Veterinary Medicine
    University of Saskatchewan
    52 Campus Dr.
    Saskatoon, SK, S7N 5B4, Canada                                                                                                          
    Phone: (306) 966-7643 
    Fax:  (306) 966-7439                                                                                                               

  • Leah Dublin asked a question in Confocal Microscope:
    Protocol for AV Explant fixing, staining, and imaging with confocal microscope?

    I am currently doing AV explants for my research and have seen in publications that people often fix, immunostain, and image the AV explants. Does anyone have a protocol for this?

  • Raid Amin asked a question in Science Statistics:
    What is Data Science, in your view?

    This new buzz word (Data Science), is it a mix of computer science and statistics? How would you define it, based on your views about it? How would you incorporate it into your own university? 

  • Cristiano Roussado added an answer in DNA Staining:
    Could i use DNase I in biofilm stained with live/dead already?


    I want to apply DNase I traitement on my biofilm which is stained with live/dead dye because i want to quantify (biovolume) my biofilm before and after treatement in the same sample. But i don't know if the DNA stain dye (live/dead) can affect the DNAse I activity, i  will test this  by comparing between staining before traitment and after traitment but it will take times..... is there some advises or suggestions?



  • Bernd Schmeikal 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.

  • Chibuike C Udenigwe added an answer in Protein Hydrolysates:
    What are the most suitable buffer used to seperate peptide from protein hydrolysate resulted from enzymatic digestion?

    hoping to know if the kind of buffer used affect on peptide separation from the whole hydrolysate.  and after separation how can i make concentration to the peptide separated and get rid of the buffer with maintaining its activity.

  • Frank Denaro added an answer in Fixed Cell:
    Anyone familiar with acetone:methanol fixation?

    Hi all,

    I am planning to fix cells, something I have not done before. So, please forgive me with these basic questions:

    1- I plan to fix my cells for immunofluorescense staining of tight junctions proteins using ice cold acetone:methanol (1:1) fixation method. I assume after I prepare the solution, I need to store them in -20C. I also assume that the solution will freeze under that temprature and I need to thaw them back for fixing my cells. Am i right?

    2- May I know how long I can store the cells before I can use them for immunofluorescence staining?

    3- How should I store the cells (after fixing them)? In 1X PBS? Or just the cells only? And at what temperature? 4C or -20C?

    Thanks in advance for your help!



    Frank Denaro

    Are you planing to do FACS, this may be a good reason for keeping them in suspension. But if you are going to be looking thorough a microscope, one approach is to fix them on the slide. To do this, wash you cells in buffer. Then  you should put a drop of your cells on a "+" slides ( which have a coating which helps the cells stick). Give them time to stick but do not let them dry out. After about  2-10 minutes, rinse them in buffer and go directly into your fix.  You can chill it .(About 10-20 secs). Then let them dry out. These slides can then be stored at -20 or -70C.  Place them in an air tight slide box with dye rite. You will be able to store them for a long time.

    There is also a modification of this fix. You can add 5 cc of 10% formalin (use the saturated formaldehyde solution to make a "10 %" solution.)  This fix  can be used in the same way. but after fixation, rinse in water and then let the slides dry. This may be a good compromise fix for what you are looking at, as you may not need to do any permeabilzation  but you have included some formalin. Good luck

  • Raid Amin asked a question in Research Statistics:
    Do you allow graduate students to work as a group on some research projects?

    I have bene experimenting since a few years with an alternative options to a Master's thesis option or the non-thesis option in mathematical sciences. We offer a two-course sequence on research in statistics (and also separately, research in mathematics). During the first semester, students are exposed to many ideas and publications, along with software packages that could be used in applied research projects. The entire class of students works together on one or two research projects that are built around one theme, such as disease surveillance (cluster analysis) of large data sets. Students work together as a team, sharing information, and tutoring each other. Each student wprks on an individual project duirng the second course. We have found a very high level of acceptance and enthusiasm by our graduate studnets to sign up for such a two-course research sequence.

    What are your thoughts on this option for research? 

  • Niousha Nazemi asked a question in 6LoWPAN:
    How to simulate a 6LowPAN network by Cooja?

    I'm trying to simulate an IEEE 802.15.4 based network with Cooja Simulator and having these modules: 6lbr, FFD, RFD, sending beacon frames , and checking the authentication of each node joining the network. Can anyone help me give a tutorial or pseudo codes, if exists, or any clue to get the result?

    Thanks in advance

  • Cristiano Roussado added an answer in Agrobacterium:
    Could anyone explain the steps of doing serial dilution of agrobacterium culture, for example, from OD_600 of 1.0 to 0.25?

    Would I need to convert units from OD to volume or density of bacteria? Thanks!

  • Oluwafemi Samson Balogun added an answer in Biostatistics:
    Would anyone consider using a free online biostatistical package?

    www.eBiostatistics.com (beta version) is the first comprehensive, web-based, biostatistical package in the internet. 

    Oluwafemi Samson Balogun

    Yes i will,once it does what i want

  • Ilya Tsyrlov added an answer in Prostanoids:
    How to preserve cardioprotective efficiency of aspirin and avoid gastric ulcers resulted from inhibition of COX-derived prostanoids by NSAIDs?

    Aspirin and numerous NSAIDs, including acetaminophen and those inhibiting selectively COX-2, are amongst the most commonly consumed drugs on the planet. Aspirin at doses less than 100 mg per day or greater than 1 gm per day have equivalent effects on platelet COX-1 derived TxA2. They both suppress it completely. However, increasing daily doses of aspirin increasingly inhibit PGI2 coincidentally with this effect, which suggest that the cardioprotective efficacy of aspirin may be progressively attenuated as the dose is increased. Similarly, locally formed, COX-1 derived PGE2 and PGI2 are protective of gastroduodenal epithelial integrity and platelet COX-1 derived TxA2 contributes to hemostatic competence. Disruption of these pathways by NSAIDs (even those which selective for inhibition of COX-2) resulted in serious gastrointestinal events. That may reflect their impact on gastroduodenal epithelial COX-2 dependent prostanoids that accelerate ulcer healing. As we still poorly understand inter-individual differences in anti-inflammatory efficacy amongst the reversibly acting NSAIDs, the hard evidence how to address the above question is in short supply.

    Ilya Tsyrlov

    Because aspirin is a medicine with a high platelet turnover rate (approximately 77% inhibition of platelet aggregation was achieved within 2 hours after aspirin treatment), it was recommended to administer NSAIDs over 2 hours after aspirin. In fact, none of the tested NSAIDs altered the aspirin effect if administration followed that of aspirin.

  • Dominique Boeuf added an answer in Bioreactors:
    Any QPCR universal primer for Bacteria?

    Hi all,

    I want to quantify the total bacteria population in my bioreactor, almost exclusively containing Bacteria.

    Do do that, I would like to run a qPCR to get a proper quantification of the population and be able to create better estimation of the ratio of each of the group of bacteria of interest I have already identify and for which one i already have adequate primers.

    Does anyone has experience with such qPCR primers? any papers to recommend?


    Dominique Boeuf

    You have different populations into the same bioreactor, right? Are they phylogenetically distant (ie are they known to have different number of 16S rDNA copies?)? If you are in pure culture, it's OK to monitor the number of 16S rDNA copies among different conditions you test but if you are not, you have to respect some cautions.
    As I work on natural populations, I always amplify sample (maybe your T0) with the primer couple I will further use, clone the amplicon, and use therefore this clone in known concentration and successive dilutions as a standard (contact me for more details, it is a little bit more complicated). I do that for 16S rDNA (it's called "absolute quantitation") and the gene targeted, then I use a ratio. You can do that with another housekeeping gene that the 16S (like recA), but you have to be sure that the primer couple is general.

    Be aware that the "abundance" view of diversity you have obtained using metagenomic is frequently very far from the real abundance (measured by qPCR) you have in the sample (in seasonal dynamics I have made it is really striking).

  • Chris Leiwakabessy added an answer in Salicylic Acid:
    I am looking for a journal on the interactions between salicylic acid, plant varieties and strains of pathogens, can you help me?

    My research on the effects of the interaction between the salicylic acid, plant varieties and strains of plant pathogens. I am looking for journals on the topic of the interaction between the salicylic acid, plant varieties and strains of pathogens. Can you help me please ?

    Chris Leiwakabessy

    Thank you asif for your information

  • Alice Barnes asked a question in Food Contaminants:
    Can anyone recommend a good dataset for a person beginning her master's degree?

    I need something that lends itself to neural network analysis.  I have a strong interest in health effects of drugs, vaccines, and possible interactions with food contaminants such as glyphosate which have become common and pervasive.

    Thanks for any help you can offer!

  • Carol Fung asked a question in GATE:
    I have accidentally created two accounts under Research gate. How can I merge the two accounts?

    I have accidentally created two accounts under Research gate. How can I merge the two accounts?

  • Guenter Grundmann added an answer in Specific Gravity:
    How to find the composition of ore whether elemental or component? And which equipment is used to find the specific gravity of the powdered mineral?

    I want to know that what is best analytical testing equipment to find out the composition of Barite. Share any research paper or book to help me out. 

    Guenter Grundmann

    Dear Mr. Ahmad,

    The first step in analyzing a pulverized ore is the study of a dispersed sample embedded in resin. From this resin-preparation a thick polished section is then made. The polished surface is then examined under a polarizing microscope under the vertically reflected light and the optical properties of the minerals can be studied. See the reference:

    Ore microscopy and ore petrography - 2nd ed.
    James R. Craig and David J. Vaughan
    i-xiv + 434 pages. ISBN 0-471-55175-9

    The particularly selected ore particles can be marked and removed for high resolution analyzers.
    High resolution crystal structure analyzers are:
    X-ray powder diffraction-device, such as a CCD diffractometer equipped Xcalibur PX Ultra. A proven evaluation method is the Rietveld Refinements (see PDF attached).

    High resolution analyzer to determine the chemical composition of single ore fragments is for example a JEOL thermal field-emission-type electron probe X-ray microanalyzer (FE-EPMA) JXA-8500F (Hyperprobe).

    The density can be calculated on the basis of the mean chemical composition and unit-cell parameters derived from the single-crystal X-ray study.

    Best regards,

    G. Grundmann

  • John Robert Hawkins added an answer in Money:
    Where can I find the dollar values or the percentages of each type of money, e.g. M0, M1, M2, and M3?

    I can't find anything other than the Fed of St. Louis.

    John Robert Hawkins

    The data are compiled by the Federal Reserve. You can find them at http://www.federalreserve.gov/releases/h6/current/default.htm

  • Juan De Sanctis added an answer in HUVEC:
    Why are HUVECs non-responsive to treatments?

    Hello everyone,

    So I am culturing HUVECs (purchased from Lonza) to estimate their activation responses to some growth factors. However, I notice no change in the output, such as cytokine production, or nitric oxide levels. Previously published reports suggest that there is an upregulating effect of these treatments.  

    I used cells between passage 2-4, and seeded in low-serum medium (EBM2 + 0.5% FBS) supplemented with hydrocortisone and ascorbic acid,  and incubated for upto 18 hours (starvation) before adding my treatments. 

    Please help me track the problem, or suggest an appropriate scheme, as I consulted many papers to follow the method but the problem seems to persist in my case. 

    Thank you very much!

    Juan De Sanctis

    Dear Manindra yes CD31 or vWF are the key markers. However the issue is to get confluent cell culture in short time. Regards,

  • Juan Pablo Carrascal added an answer in Basic Statistical Methods:
    What statistical test should I use to compare total fish catch?

    I am looking for a statistical test to compare the amount of fish catch between 2 rivers.


    River 1 caught a total of 200 fish

    River 2 caught a total of 15 fish

    Is there a test that will show if there is a statistical difference of total fish caught between river 1 (200) and river 2 (15)? My thought is to use a chi-squared test. Does this sound correct?

    Juan Pablo Carrascal

    Is the number of fish caught one single time your only variable? If that is the case, you are simply comparing two numbers, so you do not need a statistical test for that. However, you can not make any generalizations on the basis of that comparison (like saying that River 1 will always be better for fishing). On the other hand, if you have:

    - additional factors/variables, so you would be trying to find if there is an influence of such variables on the fish catch, or,
    - several data points over time for both rivers, so you would be comparing two populations,

    then you would be able to apply a statistical test.

    But it is hard to say which one would be appropriate without further information.

    I hope this helps.

  • Angelle Anderson asked a question in LIS:
    What do the terms "multiculturalism and diversity mean in the context of LIS and libraries as it pertains to this article?

    The issue of race has been evaded in the field of Library and Information Studies (LIS) in the United States through an unquestioned system of white normativity and liberal multicultural discourse. To counteract these paradigms, this paper draws from various scholarly writings about race and racial
    formation in order to center race as the primary axis of analysis in the reinterpretation of major theoretical issues in LIS. Beginning with an analysis of the historical construction of libraries as an institution complicit in the production and maintenance of white racial privilege and then turning
    toward present-day discourses surrounding diversity and multiculturalism, this paper discusses at length the epistemological forms of racism that exist in LIS.

  • Shuichi Shinmura added an answer in Discriminant Analysis:
    How can I asses if the distance between centroids is significant?

    Once I've established that at least one discriminant function is able to discriminates my groups, how can I assess if the reduced distance between centroids, that this function produces, is significant? should I use the standard criterion of +/- 1.96 SD (due to the fact that this function is expressed in standard units)?

    Shuichi Shinmura

     I think  you try t-test of discriminant scores.Just, I am writing a paper including t-test of discriminant scores about the best discriminant model.

  • Aida Arami asked a question in Neurofeedback:
    How Neurofeedback is used to cure ADHD?

    I am a  student in biomedical engineering and I interested in neuro science, I will be thankful if you help me to know more about this field.