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  • Ian Er asked a question in Drought:
    Why different molecular weight of Polyethylene glycol (PEG) give different drought stress effect on plant cell?

    Polyethylene glycol (PEG) act as drought agent to simulate drought condition on plant cell for water stress study. Why different molecular weight of PEG give different effect on same genotype of the plant cells? if What is reason behind?Does anyone know the mechanism? thank you.

  • Does a gravitation wave change propagation direction passing near a massive gravitation center (star)?

    As we know light wave passing near a gravitation center (star) changes its propagation direction. Is this true for a gravitation wave? 

    Patrick Das Gupta · University of Delhi

    Hi Minas,

     Image positions depend on the projected mass density of the Gravitational lens.

    You may see this:   http://ned.ipac.caltech.edu/level5/Mellier/Mellier2_1.html


  • Which model will be perfect for this problem?

    Outcome variable is a count variable ranging from 0 to 4. Now I have observation of outcome variable for every month up to 2 years ie. 24 observations (panel or repeated measures). Similarly, for some variables I have 24 months panel data and some demographic information variable (age, gender, etc.) as cross-sectional data. Please suggest me which model would be perfect for this type of question?  

    Jeffrey A. Tamburello · Baylor University

    It sounds like a situation for an ordered logit with a lag for the DV, possibly controlling for earlier iterations of the IV as well. Without seeing a bit more of the research, that's my thought.

    If you're privy to Structural Equation Modeling (SEM), you'd have a bit of flexibility in specifying the model, too.

  • Aida Nourbakhsh asked a question in RNA Decay:
    How can I incubate animal tissue (ileum) with Actinomycin D in an organ bath to measure RNA decay?

    I have tried to treat mouse ileum/colon tissue with Actinomycin D in an organ bath up to 12 hr time points.  I used 18s as my housekeeping gene.  When I isolated RNA with Trizol I got a very high concentration of RNA using nanodrop and the purity looked fine.  When I did RT-PCR I saw a step wise fold reduction in the 18s Ct value however for my gene of interest I did not see a reduction in Ct value.  This leads to a relative expression that is increasing overtime rather than decreasing.  Can anyone tell me what could be the possible reason for this? I am thinking that since I see a reduction in 18s Ct value the actinomycin D treatment is working.

  • Can you predict thickness of a deposited nanotube/wire from the no. of moles of metal deposited?

    Electrochemical deposition of metal through the pores of a membrane; active surface area of membrane known, and pore density known.

  • Bijan Yavar asked a question in Literacy:
    From Your Point of View What are the Important Factors Which can Turn the Social Networks to Means Which can Reduce Risks Efficiently?

    i.e. Level and Status of Literacy, Age, Gender, Facilities, Training Courses Undertaken, Level of Consciousness, Talent, EQ, IQ, SQ, etc.

  • Nicholas Stavris asked a question in Terrorism:
    Does anyone know of any good journals or books on family and the domestic space in contemporary fiction?

    Trauma studies; Post 9/11; Terrorism; Identity

  • Cristián Quintero added an answer in Lipase:
    Any suggestions on lipase purification with His tag?

    hello every one, i am expressing lipase protein with N.terminal His tag. some have His tag is not working. i am loosing great amount of protein when i do nickel affinity cinematography, i changed my His tag to C-terminal, my protein lost the activity. so i continued to work with Protein contain N-terminal his tag. but when i purify my protein further, lot of junk protein is still remained in the sample. can any one suggest me the solution for solving this issue.

    Cristián Quintero · National University of Cuyo

    Dear Dachuri,

    You can assay with an Imidazole gradient (from 20mM to 500mM). You probably will lose some of your protein in the first elutions, but the last ones should be cleaner.

    Good luck

  • Jack Silver added an answer in Peptides:
    How to isolate cationic peptides from bacteria?

    Please kindly let me know if any procedure is there to isolate cationic peptides from bacteria

    Jack Silver · Teledyne ISCO, Inc

    Would ion exchange resins work for you?

  • Kanchan Shendre asked a question in LIBSVM:
    How to plot an ROC curve for multiclass classification of attacks in IDS dataset in matlab?

    I am using multiclass SVM for classification of intrusion detection datasets (KDD corrected, NSL KDD). I am also using LIBSVM in matlab.

  • Can anyone suggest papers on agricultural risk assessment?

    I wanted a mathematical representation of agricultural risk assessment through climate change or other important factors affecting agriculture. Please help me

    Luis Fernando Gómez Gallego · Universidad del Valle (Bolivia)


    Try fuzzy logic.

  • Where can I find a drug with a name and CAS? 

    I am trying to reorder a small molecule identified in a HT screen. The main vendor does not have it, I have a CAS number, any suggestions?

    Christopher Lloyd · Field Water Testing

    I've had great luck before using ChemSpider (http://www.chemspider.com/Search.aspx) - search by CAS number in the simple search, choose the appropriate compound from the results by clicking on the idetifier number to the left and there is a "Chemical Vendors" tab below that has useful links.  Good luck!

  • Rodney E. Rohde asked a question in Medical Laboratory:
    Are you aware of what Medical Laboratory Professionals do?

    Medical Laboratory Professionals SAVE LIVES everyday by generating up to 70% of the medical data (lab results) that physicians and other healthcare professionals need to make a diagnosis and do their job. Yet, we are often a hidden profession and many people, both medical and lay public, don't understand exactly how critical our profession is to the healthcare system. Please take a moment to check out this article if you have never heard of us: http://www.elsevier.com/connect/the-hidden-profession-that-saves-lives

    And, share it with your colleagues and friends. It's a wonderful career path alternative to medical school or other allied health professions. And, if you do know who we are...THANKS and keep spreading the word!

  • How to fabricate a flexible all-solide-state supercapacitor device with good performance?

    Is polyethylene terephthalate (PET) indispensable?

    Is hot-press needed?

    Shuijian He · Chinese Academy of Sciences

    Thank you very much!

  • Antoine Balzeau added an answer in Down Syndrome:
    Is there in any collection a microcephalic skulls of an adult with Down syndrome?

    I get a request from a colleague. In the context of a paläanthropological research project he asked me for a microcephalic skulls of an adult with Down syndrome. In my collection there is not such a skull.

    Antoine Balzeau · Muséum National d'Histoire Naturelle

    nothing like this in the collection of the national museum of natural history in paris.

    as far as I know, such a case is not reported in the medical litterature.

  • Aymen Nefla added an answer in Sparrows:
    Have you seen any changes is avian population densities or species makeup during the last two years?

    During the last two years I've seen a reduction of pigeons and an increase in morning doves in the farm country of the Pacific Northwest.  The doves have replaced the pigeons from their traditional habitats, such as barns, grain silos, etc. At the same time I'm seeing a significant reduction in sparrows, juncos as well as other small seed eaters.  I'd like to know if anyone else has noticed these changes, where they are occurring and your thoughts.

    Aymen Nefla · Faculté des Sciences de Tunis

    In North African region (Algeria and Tunisia) there is a huge expansion of (Streptopelia decaocto) which replacing (Streptopelia senegalensis) at many zones. The first couple of  Streptopelia decaocto in Tunisia was recorded in 1994.

  • Nicolas Fromont added an answer in Iron Age:
    Does anyone have knowledge of postholes structures similar to that of illustration 1 in the attached document?

    Do you have knowledge of similar structures in that of the illustration 1?

    It is constituted by two series of 4 pits bounding two rectangles not centered. The outside rectangle measures 15 m by 8,60 m and is directed NNO-SSE It is bounded by 4 big pits, about 80 cms in diameter and depth, containing one post (fig. 2). The internal rectangle, of similar orientation, is however moved towards the northwest. More irregular, he measures from 4,30 to 4,70 m of length for 1,80 in 2 m of wide. Diggings are smaller and more irregular (fig. 3). The analysis of their filling is not obvious, but it seems that these structures contained one or two posts which were not necessarily were set up at the same time. Certain pits delivered some shards of rather protohistoric invoice.

    These pits are near a dozen circles, doubtless funeral although there is no rest of grave or incineration (fig. 4). In hundred meters, three enclosures of the final Bronze age and first Iron age are known.

    Thank you for your contributions

    Nicolas Fromont

    Nicolas Fromont · Institut national de recherches archéologiques préventives

    Bonjour Miroslav,

    Sorry for this late answer.

    Thank you for this information. You would have the possibility of sending me a copy of the paper which you quote, because I do not find it from on my side.

  • What is the state of the art with the levels of cognitive processing now?

    I would like to understand how my results fit within the levels of processing framework. However, I am only familiar with the original work that was completed in the 70s.

    What sources (preferably review article(s)) might you recommend for obtaining a contemporary understanding of this phenomenon?



    Nicolás Robertino Lombardi · Hospital Ramos Mejia

    You should check out Semir Zeki's work on neuroesthetics.

  • Arnold Trehub 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.

    Arnold Trehub · University of Massachusetts Amherst

    Marc: "According to this hypothesis the left claustrum would be actually your 'retinoid space ' and as such a kind of 'consciousness center'."

    1. No. The claustrum (left or right) would be the bundle of neurons connecting (synaptically) the self-locus of retinoid space and the various preconscious sensory modalities. In this case, it would be correct to say that it also "mediates increased synchronization between various cortical regions".

    2. This is  an alternative possibility that deserves further empirical investigation.

  • Isolation of genomic DNA following RNA extraction with Qiazol?

    I want to keep both the RNA and genomic DNA from brain samples.

    I'm using for the RNA extraction Qiagen's RNeasy Lipid Tissue Mini Kit, and to isolate the DNA I followed a user developed protocol available through Qiagen's page (https://www.qiagen.com/pt/resources/faq?id=54b752f7-c429-41f5-bdcd-c27263ae0255). At the end of the DNA protocol I got very little amounts of DNA with poor 260/280 and 260/230 ratios.

    I would appreciate any suggestions to this protocol or alternative methods to isolate genomic DNA from the phenol/interphase that you know that have worked before.

    Thanks in advance,


    I used Trizol method many years back. By this method also you can extract both RNA/DNA including Protein. 

    You get good amount of total RNA as well DNA too.

    check the link


    Good Luck!

  • Abdur Mirajkar added an answer in Food Analysis:
    How do I analyze pH of Asian noodles (yellow alkaline noodles)?

    Hi there. I am currently investigating on the texture properties of yellow alkaline noodles (asian noodles made with alkaline water, wheat flour) and I would like to measure the pH of raw/fresh and cooked noodles.

    I have found some papers regarding pH measurement but it doesn't seem to be consistent across the board:

    1. 90 mL distilled water and 10 g noodle sample in a stomacher bag, then measure

    2. 100 mL distilled water and 10 g cooked noodle homogenized (didn't mention which machine was used) for 5 min, stand for 30 min, and filtered before measuring

    There is limited literature on yellow alkaline noodles hence I would like to know which is the better way to measure pH. 

    Abdur Mirajkar · Pivotal Therapeutics Inc. Canada


    AOAC is not a paper .It is official monograph  of Association of Official Analytical Chemists.

  • Dominique Liger added an answer in Competent Cells:
    How can I elute plasmid dried on paper and transform chemically competent E coli cells with it?

    hi!!... I have been trying to transform TOP 10 Ecoli chemically competent cells with plasmids. These plasmids were previously spotted on paper. These were eluted by standard procedure in DD water. However i havent been successful in my transformations. The positive control for transformation that is with pCDNA plasmid and pRT101 plasmid is giving good number of colonies but nothing so far with the eluted pasmids. Please can anyone suggest a method through which i can ensure successful elution of plasmids from the paper and in concentrated form.

    thank you

    Dominique Liger · Université Paris-Sud 11

    Hi there,

    Do you know the amount of plasmid spotted on the filter paper in order to have an idea about the concentration recovered? Actually you don't need much for efficient transformation (ng range and even less) so as mentioned above make sure the plasmid has eluted from the filter prior to run transformation.

  • Psi weights are not small enough for the Ljung-Box tests. What is the implication of this result?

    Using R programming, I carried out a Model Diagnostics of the First-Order on a monthly time serial AR Model, however, the p-value and its graph could not be estimated and plotted since the psi weights are not small enough for the Ljung-Box tests. What is the implication of this result? Reference material will be helpful.

    Makuachukwu Gabriel Ojide · International Institute of Tropical Agriculture

    I am actually (comparing) fitting a particular time serial with nonlinear (SETAR) model and linear (AR) model. During Model Diagnostics, the SETAR model gave the the p-value and its graph; while AR model did not. For the AR model, the R programming I used reported that the p-value and its graph could not be estimated and plotted since the psi weights are not small enough for the Ljung-Box tests.I wish to understand the meaning and implication of that note. A material on "psi weights in Ljung-Box tests" could be helpful. Thank you, Thomas Walther for your concern.

  • Ying Zou added an answer in STAR-CCM+:
    How do I set a wall prandtl number in Star CCM+?

    I know how to set turbulent prantl number in Star CCM+,but i have no idea to set the wall prandtl number.

    If use FLUENT, we can set like this:modle-viscous model-mocel constant-wall prandtl number.

    If use OpenFOAM,it is more easier: 0 file- kappat file

    If you have any idea ,please contact me as soon as possible.

    Appreciate you!

    Ying Zou · Tianjin University

     Thank Christian,

    I' m a green hand of Star CCM+. I spend some time to understand what you said and  the user guide about user code and field funciton, but i still have some queations.

    1. Now i know what's the meaning of the prt, but if i use standard k-e model and set like this"region-fluid- boundary-my wall boundary" in Star CCM+, i will find   E and kappa, the coefficients of  dimensionless temperature function T+. I dont know the relation between E, kappa and Prt in Star CCM+. I just know a funtion of T+ in fluent. It is  about Molecular prandtl numbe, turbulent prandtl number, E and kappa. That is to say what is the function of Prt  in Star CCM+?

    2. I just know Prt=DynamicViscosity * SpecificHeat, how can i set the defined field function as you said? just in field fucntion is enougn or i have to compile the user code? I think the latter is more likely, but i think i should  make sure from you.



  • Fabian Hermann asked a question in Cyclophosphamide:
    Cyclophosphamide instead of irradiation, GvHD mouse model ?

    Is there a GvHD mouse model which uses Cyclophosphamide or an other chemotherapeutic agent instead of irradiation to create immun deficiend mice?

  • M. Baerns added an answer in Gasoline:
    What is the best method of gasoline quality check with respect to lead content?

    Gasoline, also spelled gasolene, also called gas or petrol, mixture of volatile, flammable liquid hydrocarbons derived from petroleum and used as fuel for internal-combustion engines (Encyclopedia Britannica). 

    Normally the higher the octane number the better for the engine. Previously, high octane is obtained by adding Lead which is poisonous and later was replaced  with alcohol "e.g. methanol" to give unleaded high octane. The question is how we can  check whether lead is added or methanol with a non destructive method? In Addition, if methanol is added how can we recognize that the correct percentage is added and no cheating is taking place? 

    M. Baerns · Ruhr-Universität Bochum

    don't use lead at all!!!!! :-)

  • Dimitar P. Mitev added an answer in Nanofluids:
    Can anyone suggest the method to do a teflon coating of 50 micro meter on a 100 micro meter platinum wire of length 250 mm?

    its for the conductivity test of nanofluid.

    Dimitar P. Mitev · Bulgarian Academy of Sciences

    You may try dipping into these suspensions (several times if necessary), with subsequent heating/melting:


    PS: There are also soluble PTFE-like copolymers; check the page for Teflon AF

  • Zeinab Araghirostami asked a question in Group Theory:
    Are there real world applications of finite group theory?

    I am interested in applications of topics specifically coming from finite group theory.