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  • Proloy Deb added an answer in Infiltration:
    I intend using the empirical cumulative infiltration equation  y = atα+ b, but I do not know the first scientist that proposed it. Can you help?

     I intend using the empirical cumulative infiltration equation y = atα+ b, but I do not know the first scientist that proposed it. Can you help?

    Proloy Deb · University of Newcastle

    Hello Isoteim,

    Please find the attached file as reference for your question. The equation you want to know about is although not exactly given in the article. However it is similar to Philip (1957). You can get all the details in the article provided. 

  • Albert Manfredi added an answer in RF Propagation:
    What is the best strategy for jamming frequency hopping&Direct sequence Hybrid spread spectrum signals?

    What is the best strategy for jamming frequency hopping&Direct sequence Hybrid spread spectrum signals ?

    Albert Manfredi · The Boeing Company

    Let me get this out of the way first: it's illegal to do so. But as an exercise in design ...

    There's always the brute force way. Transmit something loud in the CDMA or other spread spectrum channel. These are not UWB, where this technique would be too hard.

    A more elegant way is to design a proper femtocell, so that within close range, the spread spectrum phones in the area will switch over to that femtocell. And then you don't connect the femtocell to anything.

  • Nauman Rahim Khan added an answer in Transdermals:
    Can anyone help us with the development of an easy protocol for semi-solid transdermal drug formulations from various plant extracts?

    We want to extract active medicinal constituents from locally available plants and to formulate them into semi slid transdermal formulations like, emulgel, ointments etc.

    Nauman Rahim Khan · Gomal University

    Sir i can suggest a formulation when if you tell me what type of extract is it, means ethanolic, ether, water etc, whether hydrophilic or hydrophobic. Secondly you want to develop formulation for crude extract or specific isolated compound from that extract??How much percent formulation you intend to prepare?? After knowing this, i can then help in formulation. If wana discuss in private, email at naumanpharma@gmail.com

  • Samy Yousef added an answer in Polymer Composites:
    Can anyone help me with a UMAT Plasticity code in ABAQUS?

    I have been struggling so much to write a user subroutine for a plasticity model in ABAQUS based on the model presented in "Micromechanical analysis of polymer composites reinforced by unidirectional fibres: Part 1 Constitutive Modeling". the problem is that I can't get appropriate convergency. I know that the author of the paper has attached a CD including all codes of the thesis but I can't access to the CD. Would you please help me?

    Samy Yousef · Akhbar Elyom Academy

    Hi Mah,

    In the attached paper you will find the solution, only you will replace CNT by CNF

    With regards,


  • Med Nait asked a question in Semen:
    What are the practical criteria to define the hyperactivation of bovine semen in the CASA system data?

    I have a long time looking on the internet, I found its criteria for particularly human, rabbit, dog, rat but not for bovine sperm

  • Shih-Liang Lee added an answer in Antigen Retrieval:
    Any working protocols or suggestions to JB-4 resin immunohistochemistry?

    Hi everyone,

    I have mice skin samples fixed in 4% PFA and embedded in JB-4 Resin.

    Cut at 4 microns, I'm having trouble getting any immuno stains except for alpha-actin stains.

    I've tried multiple antigen retrieval steps, including citrate at pH 6, Tris-EDTA pH 9 and Trypsin. 

    Any suggestions would be greatly appreciated. 

    Thank you.

    Shih-Liang Lee · Heart Research Institute

    Thanks for the replies.

    The main concern with JB-4 is that it cannot be deplastinated, so I've been playing with antigen retrieval steps. 

    I know the marker works because I've done it on paraffin (looking for CD31).

    My general primary incubation is always overnight, and from experience that's pretty much the best you can do.

    Currently exploring the option of ABC detection method to greatly amplify the signal, so any suggestions would again be appreciated!

    Thanks again

  • Lagiem El-aguri added an answer in Nitrification:
    What do r-strategists or K-strategists mean in nitrification processes?

    What does r-strategists or K-strategists mean ? for example,
    Nitrifiers bacteria can be categorized as either r-strategists or K-strategists.

    Lagiem El-aguri · Concordia University Montreal

    Kindly, let me know if I got something wrong!

  • A. A. El-Sayed added an answer in Chelating Agents:
    Does anyone have an idea of whether EDTA affect the measure of calcium concentration by ICP analysis?

    Now I have a solution of calcium in EDTA medium (the concentration of EDTA.2Na varys from 0.1% to 3% ), I want to determine the calcium concentration in such solution.

    Since EDTA (or EDTA.2Na) can form complexes with calcium (acting as a chelating agent), I am wondering if EDTA can be a factor influencing the determination by ICP-MS (a quadrupole inductively coupled plasma–mass spectrometer) or ICP-AES (an inductively coupled plasma–atomic emission spectrometer ).

    A. A. El-Sayed · Taibah University

    i think at 9000 k the temperature will destroy the bond between edta-ca. however the only factor affect will be the matrix

  • A. Subba Rao added an answer in Nitrogen:
    How do I check the percent recovery of nitrogen in a Kel-plus distillation system?

    May I know the chemicals to be used and procedure to be followed for understanding the accuracy and percent recovery of nitrogen in Kjeldahl automatic Nitrogen distillation system (KEL PLUS)...?

    A. Subba Rao · Coromandel International

    Dr.Srivastava,please provide the reference  based on which you commented that the Asija and Subbiah method incorporates sizable fraction of non -mineralizable nitrogen pool of soil.Dr.Gyawali,it is probably Subbaiah and Asija 1956 not Asija and Subbaiah,!956 please check.

  • Sana Ullah asked a question in Comet Assay:
    Principles of Comet Assay?

    Dear Researchers,

    According to you: What are the basic principles of Comet Assay?

  • Gerald Doh asked a question in RNA-Seq:
    UV to inflict DNA damage to HEK293 cells in culture?

    I am studying a protein and from imaging I can see that my protein is recruited to sites of DNA damage. I wish to UV irradiate HEK293 cells in culture prior to collection and analyses by RNA-seq and mass spectrometer. Does anyone have an idea of how to (protocol and instrumentation) UV irradiate cells in culture for such studies? 

  • Geng Ouyang added an answer in Philosophy of Cognitive Science:
    Are curiosity and the freedom to doubt. Identical, or dizygotic twins?
    • To many Physicists, Richard P. Feynman is either known as the Nobel Laureate who shared his prize with Julian Schwinger about some mathematical problems in quantumelectrodynamics and how to solve them - with a trick.
    • Or they know Feynman as the author of the Feynman Lectures in Physics, I think 3 books on Experimental Physics which were even recommended for the Theoretical Physics course at my alma mater.

    Or they know Feynman for both.

    • I know Feynman particularly for the other books - about him. Surely you're joking, Mr. Feynman. Six not so easy pieces. Six easy pieces. What do you care what other people think? ...

    Tonight I came across a YouTube video with Bertrand Piccard, where he gave a public lecture on Zeitgeist Americas 2013:


    Piccard, who is known for a number of pioneering which I would call "aeronautical stunts", starts out in his lecture with a claim, a statement which he read at the entrance to his auditorium. It's being claimed there: "Everyone is looking for new things all the time."

    Piccard responds: "I'm not sure it's true. I believe that maybe here in this room we are all looking for new things. We are curious. And actually we find our balance into the unknown. But so many people in life don't trust life at all. So many people are afraid of the unknown. Afraid of the doubts. Afraid of the question marks. So what do they do? They try to find completely other tools than curiosity. They try to find control, power, speed. Because this helps them to fight against the doubt and the question marks. This helps them to fight against the uncertainty, against the "changeants". Against everything that can threaten their comfort zone. So what I love so much in ballooning actually is the fact that when you fly a balloon you learn exactly the other things, exactly the opposite, exactly the contrary. You learn to have - no power. Because you have no engine. You learn to have no control, because you're pushed by the wind. ..."

    Now this is very interesting, the distinction between a) people who are curious and in there find their balance, b) and those people who are scared of doubts and questions and rather seek power and control for their balance.

    When I heard these words from Piccard, I was then reminded of Feynman who elaborated on the "Meaning of it all" and "The Freedom to doubt".

    Let me quote (http://laserstars.org/bio/Feynman.html) here Richard Feynman from the book "What do you care what other people think?:

    "The scientist has a lot of experience with ignorance and doubt and uncertainty, and this experience is of very great importance, I think. When a scientist doesn't know the answer to a problem, he is ignorant. When he has a hunch as to what the result is, he is uncertain. And when he is pretty darned sure of what the result is going to be, he is in some doubt. We have found it of paramount importance that in order to progress we must recognize the ignorance and leave room for doubt. Scientific knowledge is a body of statements of varying degrees of certainty -- some most unsure, some nearly sure, none absolutely certain.

    Now, we scientists are used to this, and we take it for granted that it is perfectly consistent to be unsure - that it is possible to live and not know. But I don't know whether everyone realizes that this is true. Our freedom to doubt was born of a struggle against authority in the early days of science. It was a very deep and strong struggle. Permit us to question -- to doubt, that's all -- and not to be sure. "

    And this reminds me of an opinion brought forward by John F. Kennedy in his well known speech "The President and the Press", where he says "No President should fear public scrutiny of his program. For from that scrutiny comes understanding; and from that understanding comes support or opposition. And both are necessary."


    Obviously, the principle of doubt (controversy) which is known to scientists as a painful evolution (Galileo Galilei) has made it also into modern politics, at least by Kennedy, and to at least one ancient lawmaker (Solon), if you read on Kennedy's speech.

    Whereas in law making and in politics, doubt could be considered a necessary systemic reflex against unilateralism and totalitarianism, in science I believe it could have a true academic origin, this is the curiosity.

    Coming back to Piccard's speech, he says there is two sorts of people, the ones who are curious, I would say the ones who seek questions, rather than answers. And then there is the other class of people, those who  cannot stand questions and won't rest until they have an answer. The latter are the ones who need control over things, the ones who are not apt to the idea of freedom.

    Can the aforementioned systemic reflex of doubt against unilateralism still be considered as originating from the same field like the freedom to doubt in scientific affairs?

    Geng Ouyang · MinNan Normal University

    Dear Mr. Tushar Kanti Ray,

    I think it is really difficult sometimes for a researcher to govern and balance the subjective and objective worlds because they both exist as the knower and the cognized worlds are both exist, too. Each knower has his (her) own inside subjective world.

    Too much subjective portion or too much objective portion in our research fruits (knowledge) will surely hurt the scientificity of our research fruits (knowledge).

    It is also really difficult sometimes for a knowledge learner to identify the content proportion of subjective and objective worlds in our knowledge--------- the scientificity of our research fruits.

    Yours, Geng

  • Raul A DeLa Cadena added an answer in Plasminogen:
    Has anyone done an in vitro plasminogen activation assay?

    I'm looking for a proper cell line and protocol to test the inhibition of a known plasminogen receptor. I'm thinking that exogenously adding plasminogen and then immunoblotting for cleaved plasmin would be an appropriate way to measure this. However, in this case the cells used would need to express tPA and/or uPA and I'm having a bit of trouble finding an appropriate cell line. Possibly a vascular endothelial cell line? Any suggestions would be helpful. 

    Raul A DeLa Cadena · Temple University

    Only one was uploaded by the system, here goes the second one, this one is on fibroblasts and looking for thrombin and FXa instead of plasmin. As you can see, the chromogenic substrate provides the specificity of the enzyme you are interested in measuring. You are lucky because there is one for plasmin S-2251.

  • Paul Kowal added an answer in Research Projects:
    How do I get the latest elderly population data?

    I am doing one research project so i need elderly population

    Paul Kowal · World Health Organization WHO

    Dear Prashant, 

    Just to let you know that the UN Population Division just released the World Population Prospects: 2015 Revision, at: www.un.org/en/development/desa/population/events/other/10/index.shtml

    A recent publication highlighted the quality of the UN data in the cross-section and over time.  It allows you to generate whatever population data you require, include proportions of older adults by age and sex, life expectancies, etc., for all countries in the world - and adjusts for some of the politicization that may be associated with some national data.

    "An Aging World 2015" is also on the horizon from the US Census Bureau, see for example, www.census.gov/prod/2009pubs/p95-09-1.pdf

    Sincerely, Paul

  • James Dalton added an answer in Plasmids:
    Can anyone suggest a protocol suitable for preserving of plasmid for long time period without it getting denatured?

    Is there any such suitable protocol,please let me know.

    James Dalton · University of Auckland

    All of the above methods work great, the only one I'll add is to keep it in a bacterial strain (which one depends on the plasmid) and then store the bacteria as normal (with glycerol at -80C or even in liquid nitrogen). You just revive the strain and do a plasmid prep when needed. As long as there is one bacterium that you can culture you can rescue amplify your plasmid. 

  • Vasundhra Bahl asked a question in PCR:
    Fold change in my end point PCR (checked through a gel) is not the same as array based RT PCR. It is normal or should they match?

    I ran an array based q PCR and obtained data for fold change in genes. I followed this up by running end pint PCR followed by a gel. But the fold change in my end point PCR is not the same as as in my RT PCR. The primer sets are different and conditions were different as the RT PCR was a profiler array from Qiagen.  Does this usually happen or should the fold change in RT PCR and end pint PCR be the same?

    Thank you

  • Alexander V Panov added an answer in Functional Assays:
    Anyone familiar with mitochondrial isolation from small tissue samples (~100 mg)?

    Does anyone have a protocol or experience with a mitochondrial isolation kit to obtain good quality mitochondria for functional assays from small tissue samples (100-200 mg)? Any suggestions would be much appreciated!

    Alexander V Panov · Institute of Molecular Biology and Biophysics

    With skeletal muscle you MUST use treatment with Nagarse (protease) because usually without this treatment the yield of subsarcolemmal mitochondria is too small. Just wash thoroughly to remove the enzyme. There is also the method with isolation with KCl, but I personally have mo experience. what do you do with the mitochondria.

    Just curious. Do you know where Natasha Kubalik is? Regards to your husband.



  • James Dalton added an answer in Plasmid DNA Isolation:
    In isolation of plasmid DNA from bacterial cell by alkali lysis method, why couldn't I observe band on agarose gel?

    while performing the experiment - isolation of plasmid  DNA from bacterial cell by alkali lysis method , i got O.D at 260/280 nm as 0.976 on spectrometer. And I couldn,t observed the band on Agarose gel ,what could be the reason for it. Can anyone suggest me an alternate method for plasmid DNA isolation?

    James Dalton · University of Auckland

    Using the commercial kits definitely saves you a lot headaches. If have personalyy used the Qiagen and Macherey Nagel ones and they all work fine.

    If your lysis step is too long you will drastically reduce your yield. Too much vortexing will result in sheared DNA (usually seen as a smear on a gel). Sounds like you had a low/ no yield.

    Also double check the conditions required for maintanance of your plasmid. Check if it is low copy number/ high copy number. Low copy number plasmids sometimes need maxi prep kits and a lot more culture than you would normally use. 

  • Yan Yan added an answer in Family Violence:
    Can someone help with the history of domestic violence?

    I have already seen some articles and books about domestic violence. I want to know when the public start using uniformly the phrase "domestic violence" to describe family violence ,that is to say, when regarding the phrase as the standard expression. Additionally, some think that is interchangeable between domestic violence and intimate partner violence. Originally, isn't there any differences between them in the perspective of relationships? What is the differences? The reason why i question so is because i want to figure out when cohabitation is put into the protection of violence against women act. Then i question ,is it appropriate that in China cohabitation is within the protection of law. Please reccommend some articles and books. Thank you.

    Yan Yan · China University of Political Science and Law

    Recently, i find out one report about California response to domestic violence. It said that the California  Assembly passed the motion, SB691.Chapter912 raised by Senator Marks in 1977. The revision refer to the extension of Penal Code Section 273.5 from spouses to cohabitating partners. Is it earlier than California? Yet i don't know. So i decide to figure out the historical change of California in legislation and judiciary. It will narrow my scale of searching and drive my energies to focus on dealing with one point. Next, hope i would have new progress. I will update in time.

  • Richard R. Shaker added an answer in Ocean:
    How do rivers affect the salinity of oceans?

    How do rivers affect the salinity of oceans?

    Richard R. Shaker · Ryerson University


  • Samy Yousef added an answer in Polymer Composites:
    How do I disperse nanoparticles/tubes/wires/crystals in polymers?

    Nano particles, Polymers, Composites, 

    Samy Yousef · Akhbar Elyom Academy

    If you need to produce bulk polymer nanocomposite please check this link

  • Richard R. Shaker added an answer in FRAGSTATS:
    Does anyone know a R package to calculate a contagion/proximity index for a cover class ?

    I’m looking for an index/metric that will permit to quantify the contrasting spatial distribution of a cover A (which is located mostly in the south of my study area) vs. a cover B (which is well distributed over the study area). I know that Fragstats can do that but I dont have the spatial analysis extension in my computer. Thank you for your answers !!

    Richard R. Shaker · Ryerson University

    I would agree that the best landscape metrics R package remains: https://cran.r-project.org/web/packages/SDMTools/index.html

  • Richard R. Shaker added an answer in FRAGSTATS:
    Does anyone know a R package to calculate a contagion/proximity index for a cover class ?

    I’m looking for an index/metric that will permit to quantify the contrasting spatial distribution of a cover A (which is located mostly in the south of my study area) vs. a cover B (which is well distributed over the study area). I know that Fragstats can do that but I dont have the spatial analysis extension in my computer. Thank you for your answers !!

    Richard R. Shaker · Ryerson University

    Dear Yan,

    If you have not seen this yet, a good place to start would be: http://www.statsteachr.org/

  • Charles E. Pekins added an answer in Camera Trapping:
    Can you suggest articles on camera trap data analysis techniques?

    Any one with scientific papers or any leading information on carnivore density estimation using camera traps preferably data analysis ? kindly assist thank you. 

    Charles E. Pekins · United States Army

    My colleague and I published a paper on density estimation of North American bobcats using camera traps and SECR analysis.

  • Fadoua Ataa Allah added an answer in Computational Linguistics:
    What are the best currently available (and preferably open source) Chinese textmining tools?

    Textmining tools are become ever more useful, but it remains difficult to find good tools for CJK languages. If anybody knows of good tools for - especially - Chinese, I'd be grateful for a link. 

    Fadoua Ataa Allah · Institut Royal de la Culture Amazighe

    Try also the following tools. They are usful form many languages including chinese.

    Good luck.

  • Guillermo Auad added an answer in Land Surface Modeling:
    Is there any simple atmospheric model with community land model available in the literature?

    I am trying to study land surface process sensitivities on the surface fluxes. So, I need simple atmospheric model that responds to the changes in the surface fluxes done by the tinkering of processes in the land surface model. Could anybody please suggest me the model for my needs.

    Thank you.


  • Guillermo Auad added an answer in Air-Sea Interaction:
    Where can I find information about coupling two models ( WRF & ROMS )?

    I wanted to couple WRF V3.4.1 and ROMS (Regional Ocean Modeling System) to study some properties of air-sea interaction. Where can i find valuable information about setting and other setup information in web?

    I have a very low configured computer resource (A small server with 12 gb ram). Is it possible to run the models in there for 5 days data?

    Thanks in advance

  • Samy Yousef added an answer in Polymer Blends:
    Can anyone give me an example for synthetic polymer blends?

    I read the papers on polymer blends but most are related with natural polymer but i want synthetic polymer blends for bio-medical applications?

    Samy Yousef · Akhbar Elyom Academy

    For bio-medical applications, you must using POM, PEEK and UHMWPE as a base polymer material and CNT or Graphene as nanofiller material 

    For mixing nanofiller with POM and PEEK please check this link 

    For mixing nanofiller with UHMWPE (Ball milling or Min lab Extruder). If you are interesting I will explain for you