Q&A

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  • L. Jagadeesan asked a question in Marine Biology:
    Can anyone help to calculate the zooplankton Biomass and Density in vertical hauls and their expression?

    Zooplankton

    Marine Biology

    Plankton

  • Krzysztof Krygier added an answer in Functional Food:
    Are toxicity studies required for functional foods?

    we are developing a functional food , so would like to know whether sub- chronic toxicity study is required.

    Krzysztof Krygier · Warsaw University Of Life Sciences

    Toxity studies are required for all types of foods, including functional foods. Special studies are not required, because formally functional food does not exist.

  • Marcella Bini added an answer in SEM Analysis:
    How sample can be prepared for SEM analysis???

    Hi everybody...

    I have prepared Ni doped ZnS nano particles, for SEM analysis, how sample will be prepared???

    Marcella Bini · University of Pavia

    I think that the previous explanation is complete. In general I don't press the powder but I blow away the excess of powder with compressed air. If you want to perform also EDS analysis maybe it can be better that you covers your particles with carbon, to avoid the gold interference.

  • Jelle van Dijk added an answer in Visual Fields:
    How can we test machine consciousness? How can we test various theories of consciousness?

    What are the existing tests for machine consciousness that directly tests qualia generated in a device? I find many proposals, but they only seem to test functional aspects of consciousness related neural processing (e.g. binding, attentional mechanisms, broadcasting of information), but not consciousness itself.

    I have a proposal of my own and would like to know how it compares with other existing ideas.

    https://archive.org/details/Redwood_Center_2014_04_30_Masataka_Watanabe

    The basic idea is to connect the device to our brain and test if qualia is generated in our "device visual field". The actual key to my proposal is how we connect the device and how we set the criteria for passing the test, since modern neurosynthesis (e.g. artificial retina)  readily leads to sensory experience.

    My short answer is to connect the device to one of our cortical hemispheres by mimicking inter-hemispheric connectivity and let the device take over the whole visual hemifield. We may test various theories of consciousness by implementing candidate neural mechanisms onto it and test whether subjective experience is evoked in the device's visual hemifield.

    If we experience qualia in the "device visual hemifield" with the full artificial hemisphere, but not when the device is replaced with a look-up table that preserves all brain-device interaction, we have to say that something special, say consciousness, has emerged in the full device. We may conclude that the experienced qualia is due to some visual processing that was omitted in the look-up table. This is because, in regard to the biological hemisphere, the neural states would remain identical between the two experimental conditions.

    The above argument stems from my view that, in case of biological to biological interhemispheric interaction, two potentially independent streams of consciousness seated in the two cortical hemispheres are "interlinked" via "thin inter-hemispheric connectivity", without necessarily exchanging all  Shannon information sufficient to construct our bilateral visual percept.

    Interhemispheric connectivity is "thin" in the sense that low-mid level visual areas are only connected at the vertical meridian. We need to go up to TE, TEO to have full hemifield connectivity. Then again, at TE, TEO, the visual representation is abstract, and most probably not rich enough to support our conscious vision as in Jackendoff's "Intermediate Level Theory of Consciousness".

    The first realistic step would be to test the idea with two biological hemispheres, where we may assume that both are "conscious". As in the last part of the linked video above, we may rewire inter-hemispheric connectivity on split brain animals to totally monitor and manipulate inter-hemispheric neural interaction. Investigating conditions which regains bilateral percept (e.g. capability of conducting bilateral matching tasks) would let us test existing ideas on conscious neural mechanisms.

    Jelle van Dijk · Universiteit Twente

    Do you know Scott Kelso's work?

  • Julien Prados added an answer in Feature Selection:
    Is it necessary to do feature selection before classification by SVM algorithm?

    e.g., 100 dimensional features, and 200 observations. Thanks

    Julien Prados · University of Geneva

    I'm sorry to go against most of the answer, even very categorial once, but I do think that feature selection is not necessary for SVM algorithm. It is because SVM already embedded a feature selection algorithm with the regularization term controlled by the C parameter. The C parameter can indeed be seen as a parameter controlling the number of feature to select by the SVM for classification, and the kernel function is here to build an appropriate feature space. 

    What is however important is to optimize the C parameter, and eventually the kernel function. I you do so, I think that most of the feature selection methods would decrease your SVM classification performance because they are not aware of the classification algorithm and then there is a risk to eliminate pertinent features.

    Good luck,

  • Ahmet Karakoç asked a question in GRASS GIS:
    What does it mean "litter degradadtion"?

    litter is degradation of grasses.

    is litter degradadtion "degredadtion of degredated grasses?."

    Cite: "....lingin end nitrogen govern  litter degredation". (He and Mui, 2010).

  • Javad Asad Poor added an answer in Content Analysis:
    Who knows any research work (paper, book, reviews) related to implementation of content analysis in investigating the concept of "city images"?

    In operating a qualitative research one of the analysis techniques that is highly applicable in analysing subjective and abstract concepts, i.e. city image is a method namely content analysis. Since my research deals with the concept of city image I think this analysis technique should be useful, and I appreciate any information related to this analysis technique especially in association with my topic which is"city image".

    Javad Asad Poor · Mashhad Branch-Azad University of Iran

    Dear Sedighe

    Thanks a lot. May I know the topic of the research? If possible let me know how to make a connection with youfriend?

    Sincerely Yours

    Javad

  • Jose Manuel Sanchez Vilchez added an answer in Fault Diagnosis:
    Can anyone suggest literature on fault diagnosis?

    i need some literature on fault tolerance systems and diagnosis.

    i want to apply machine learning techniques .

    Jose Manuel Sanchez Vilchez · Institut Mines-Télécom

    I have a paper (self-modeling based self-diagnosis) and a poster (Self-healing Mechanisms for Software Defined Networks) on fault diagnosis. Inside, I cite very interesting model-based diagnosis approaches for fault diagnosis that you may find suitable in your case 

  • Yavar Mahmoudzadeh added an answer in FRAP:
    Can I do the FRAP test (total antioxidant) in animal tissue?

    i want to estimate total antioxidant(with FRAP test) in the liver tissue homogenate but the frap test usually done in serum or plasma.whats difference between method of meassuring FRAP in serum and tissue homogenate?

    Yavar Mahmoudzadeh · Ardabil University of Medical Sciences

    Tanks all

  • Xiaohan Du added an answer in Abaqus:
    How can I use MATLAB to call ABAQUS?

    Hello! 

    I was learning linking ABAQUS with MATLAB in this website: http://www.overvelde.com/#downloads

    Where I downloaded the content in ''ABAQUS MATLAB connection''.

    So I typed: system(['abaqus cae script=Main.py']) in MATLAB, and put file Main.py in ABAQUS Temp folder and MATLAB path. 

    However after clicking run, I got this error: The system cannot find the path specified.
    Abaqus Error: The following file(s) could not be located: Main.py 

    Can someone explain why? I already put Main.py in Temp.

    Thanks!

    Xiaohan Du · Cardiff University

     Now it is done! I simply deleted this line in Python code ''from Numeric import*'',and it worked! Thank you all!

  • Alex See added an answer in Materials Physics:
    Why does the XRD show a single phase after sintering, while the SEM clearly showing the second phase CeO2?

    XRD of calcined samples of Ce-doped SrTiO3 is showing the peak of secondary phase, but after sintering the sample at 1300C the XRD  not showing the peaks of secondary phase. But, the SEM images of the same samples clearly showing secondary phase. what is the reason behind it? 

    Alex See · Putra University, Malaysia

    After plotting and looking at your XRD, I did not find any broadening effect which may account for possible amorphous or secondary phase formation. You may need to consider that the Rietveld analysis of the possible peaks in your XRD. Depending on your material processing temperature, I think that the Ce doping effect may not have a strong presence due to the difficulty in displacing the Strontium from SrTiO3 structure.; unless the SrTiO3 has a liquid state which Ce diffusion can take place. 

  • Vasile Surducan added an answer in EMI:
    Is there unwanted effect of double shielding of EMI source in Faraday cage?

    Hello.

    I have a plan to make new version of Faraday cage for gas discharge circuit. Unlikely to current cage in which radiation sources such as Thyratron and capacitor are just proximate to some electronics related to discharge triggering, This new box will have additional shielding room for these sources as seen in the attached images.

    At this moment, I don't know which is good way to get more effective shielding. one image (1st case) shows additional shielding room shares one side to whole Faraday cage while the another (2nd case) is isolated type which is connected to inner surface of the cage via wire.

    In 1st case, What I'm worrying is the possibility that EMI directly hits the cage thus cages are all fluctuated in voltage if EMI is severe.

    Actually EMI is severe. When we enclose the capacitor with aluminum foil, foil is shaken!

    Could you tell me anything about these two design?

    In 2nd case, does external surface of the isolated shielding room keep itself equipotent no matter what happens inside?

    Vasile Surducan · National Institute for Research and Development of Isotopic and Molecular Technologies

    It's not clear for me if you are building those cages to suppress the EMI generated by a device mounted inside the cage to protect the external environment or not. Perhaps you should take a look to anechoic chambers if your purpose is just to take a measurement (for a paper...:) A simple Farady cage is usually so poor that you can call a GSM phone inside without any issue.

    Perhaps case 1 of your drawings is better if:

    a. you are using solid and thick metallic enclosures and

    b. the ground is separately conducted from many points of the outer cage (do not use only one) and many points of the inner cage, to the lowest ground impedance point (measured) using large cross section flexible copper band.

    However, will be a trick to pass the inner cage ground wires to the outer world...

  • M. B. Muradov asked a question in Analytical Chemistry:
    How I can determinate concentration of Total Petrolium Hydrocarbons by UV Vis Spectroccopy?

    Analytic Chemistry

  • Marco Emanuele Favretto added an answer in Nano Biomedicine :
    What is the best biodegradable nano-particle to be combined with papeine enzyme specifically for colorectal cancers that are MDRs?

    I am formulating a food supplement (nano-particle + papeine enzyme) that can be used as an alternative for those who are diagnosed with colorectal cancer that are MDR.  Yes it can also be a "preventive measure".  Genes of those with family history of colorectal cancers may also be prone to have liver or breast cancer, and yes, i am searching for a specific biodegradable nona-particle (to become a food supplement) that may be used to prevent cancers from worsening and/or occurring. Thank you for your help. 

    Marco Emanuele Favretto · University of Chester

    You will face problems, serious problems, going for oral delivery of nanoparticles. It is not impossible, but they really have to deal with lots of unfavorable conditions in the GI tract, mainly acidic gastric environment and the continuous secretion of mucus that protects the GI tract.

    So, you have to find something which is acid resistant (and this likely takes all the polyesters out of the game, even though PLGA/PLA, with and without PEG have been used) and can adhere and permeate the mucus. This limits the choice to polysaccharides (better if they contain a glucosamine unit), methacrylates and polysterene particles, which of course are not biodegradable.

    Ideally, you may want to try to cover PLGA particles with chitosan, but you will have major problems encapsulating the enzyme in this system.

  • Jeremy Dudley added an answer in Activated Sludge:
    'Coeff.for ThOD of SNO3 and O2 are negative for electron donors relative to the redox reference fr ThOD'. Should they be 'electron acceptors' instead?

    In the book "Activated sludge model ASM1, ASM2, ASM2D and ASM3" IWA, it says states page 109, line 4 from the bottom left.

    Jeremy Dudley · WRc Plc

    Reading the report, it looks like you are correct. The best I can offer is that 'electron acceptors' are treated as 'negative electron donors', but that isn't terribly clear.

  • Marco Kelders added an answer in Primer:
    Could anybody please give an advice for RT-PCR Primer selection?

    I'm new to RT-PCR and now have searched for the primer sequence to process RT-PCR.

    I have question that for the same gene expression, can I use the same Primer that is used in q-PCR for RT-PCR ?

    Will there be any effect ?

    Thank you for your answer. 

    Marco Kelders · Maastricht University

    Random primers are used in the RT-reaction, not in a qPCR.... and using random primers, oligo-dT or gene specific primer depends on the experiment.

    But in addition to what is already said above, if you use qPCR primers which normally produce amplicons of 100 bp or maybe even smaller (we have also amplicons of <80 bp), and you separate your RT-PCRs on gel, just be aware that primer dimer bands might run close to your amplicons. Use a good marker (like a 25bp ladder) and run long enough to resolve your bands.

  • Gordon Chirgwin added an answer in Eccentrics:
    I need help calculating the Plastic resistance of an eccentrically loaded CFST Column?

    I need help calculating the plastic resistance (Squash Load) of an eccentrically loaded concrete filled steel tube column. EC4-1-1 did not give a very good explanation on how this could be achieved. i will really appreciate a reference where i can get this equation from.

    Thank you.

    Gordon Chirgwin

    Does EC4 1-1 hove a temperature curve or formula?  If so, set the temperature at ambient and the result should come out.  The elevated temperature part of the function is to correct for the reduction in strength and stiffness for steel at high temperatures.

  • Stephen Ategie asked a question in GDP:
    Growth rate of real GDP(%) or Real GDP($m) as dependent variable in OLS Regression?

    Hello everyone. I did a regression using growth rate of real GDP(%) instead of real GDP figures($m). Would this affect my OLS regression analysis? I am asking because i got some really strange values after conducting the regression analysis.. For example a negative adjusted R2.

  • Magdalena Schimke asked a question in Incubators:
    Copper-based cell incubators - good or bad?

    Does anyone has experience with the usage of Copper-based Cell Incubators? Causing benefits or trouble? Corrosion vs antibacterial effects?

  • Elena Yu. Ladilina added an answer in Nanoparticle Research:
    Respected members, which is the best way to add reducing agent to the solution for nanoparticle synthesis at high temperature?

    i am using three neck round bottom flask on the heating mental at 250oC, usually i add precursor, oleylamine, surfactant and reducing agent at the same time and then i rise the temperature to 250oC but i can not get any product.

    Elena Yu. Ladilina · Russian Academy of Sciences

    Oleylamine can react with W(CO)6 before 250o.

  • Jacques Gleyse added an answer in Masculinity:
    Does anyone know about a measure of masculinist beliefs and attitudes?

    I am interested in people's beliefs and attitudes regarding masculinism, and I am having a hard time finding a measure of such concept that could be used in standard research questionnaires. Any suggestions welcome!

    Jacques.

    Jacques Gleyse · Université Montpellier

    Hello

    I suppose you well know the works of John Williams and Susan Benett (1975) and the other one most general about John Williams and alii. in the journal Sex Roles or those of Sandra Bem (BSRI). Bests regards.

  • Padmagiri G.C. asked a question in Endemism:
    Can someone suggest good reads for Species Colonisation and Endemism?

    Hi,

    I am interested to read more about how species start colonizing in an area and what factors leads for Endemism, can anyone suggest a few good papers or books that I can read?

    Thanks!

  • Yusef Maleki added an answer in Biofouling:
    How can I reduce small pressure variations in tap water pipes?

    The tap water pressure is about 3.5 bar and is varying up to maximal +/- 0.2 bar with time. The pressure variations seem to cause small unwanted variations in water flow in the monitors that are used to study biofilm formation (biofouling) in membrane systems applied for water treatment. The total water flow is 100 to 200 L/h depending on the experimental design of the study. The feed pressure originates from the tap water (pumps located at the treatment plant, several kilometers away from the research location).
    A recommended Wanner-Hydracell pump has been tested ((1) with and without an overflow vessel prior to the pump to have constant pressure before the pump and (2) with and without a pressure reducer after the pump): but the best combination caused still larger pressure pulses (and larger flow pulses} than using tap water feed pressure directly..

    Yusef Maleki · Högskolan i Borås

    Good, you can test it at another location.

    Good luck .

  • Teodora Stella Wijasa asked a question in PMI:
    Best way to do a synaptosomes preparation from Postmortem Human Cortex?

    Dear all, I am trying to do a synaptosomes preparation from Postmortem Human Prefrontal Cortex (frontal). I read few articles, they used 1 to 5 gram at the beginning. I started with low amount of frozen brain, around 300 mg (PMI < 4 hours). From 300 mg weight of prefrontal cortex, I generally obtain ~25 micrograms of total protein from isolated synaptosomes. 

    Is anyone have any idea to increase the yield at the end (beside increasing the weight of the brain)? I do not have a high amount (weight) of human brain.

    Each minced prep is immediately homogenized by applying 20 slow stokes using a teflon-glas tissue grinder (grinding chamber clearance is 0.15 mm). Then I use layering of discontinuous sucrose gradient.

    I am thinking to use a glas-glas tissue grinder (grinding chamber clearance is 0.025 - 0.076 mm).

    I welcome any idea.

    Cheers,

    Stella

  • Ravi Ananth added an answer in X-ray Reflectivity:
    Would anyone have a clue as to the origin of "unexpected spots" in the real time 2D XRR signal from thin film samples on substrates?

    X-ray reflectivity (XRR) is a technique abundantly used and vetted, for determining film thicknesses and "flatness" of thin film samples on substrates, over the past century. We have implemented this method in real time using a 2D detector to examine (1) the NIST 2000 SRM (standard reference material) and (2) a sputtered Pt thin film sample on (001) Si substrate.

    The 2D XRR signal was acquired using AXIS25 2D imaging system with spatial resolution of 27.7um, 12.5 fps, 12 Bit dynamic range. The XRR signal using Omega-2Theta scan, shows some interesting persistent "spots" on either side of the "main beam". I'm unable to ascertain the origin of these "unexpected spots" that appear in both cases. We've used the Bruker D8 for the NIST 2000 sample and a Panalytical X'Pert for the Pt. thin film with nearly identical optics and beam conditioners. The incident beam was monochromated to KAlpha 1 only while the KAlpha 2 component was  attenuated!

    Please share your experience and knowledge in XRR to help explain the origin of these "unexpected spots". The angular range (0-0.2o, between the main beam and the total internal reflection angle) is too small for these to be from some diffraction phenomenon such as "slit scattering", isn't it?

    Your helpful suggestions will be deeply appreciated!

    Ravi Ananth · OnSight Technology USA

    You are the Man, Dirk! Thanks a million for sharing & opening this awesome "door" to knowledge! We are all embellished and un-afraid of fruits from the "knowledge tree" :-)

    • What is the practical implication of these observations?
    • What Nano structural parameters could be extracted from such observations?
    • How do we take advantage of this in a practical "production" environment since we can quantify it without the help of the Synchrotron?

    Danke! I have a lot to learn yet :-)

  • Carmen Wrede added an answer in Philosophy Of Science:
    Is the economic collapse – a black hole syndrome?
    Mathematics justifies that greed and extreme selfishness cause economic collapse of societies.

    Any system that is established from relations from different groups and the forces created thereof, continues to exist if the relations remain fair and the forces that are created from the relations to keep the system alive remain on balance and valid to all parts. When one of the forces dominates to the extent of diminishing the strength or eliminating the powers of others, then only a force of pulling towards the dominant entity remains and that leads to the collapse of the system - this is what I call it the black hole syndrome.

    What do you think, is greed and extreme selfishness the cause of economic system collapse?
    Carmen Wrede · FernUniversität in Hagen

    "I understand that German people are to stress the individualism because of the Nazi past."

    I understand that some people are to stress conforminism because of a misunderstanding of spirituality. The funny thing is that I have seen that is Buddhism and likewise in some parts of the Russian society.

    "Philosophers call this as the difference in category."

    I am well educated enough in philosophy to know each and every position and even the western view promoted by Keupp. Believe me: I understood you and I understood you right.

    Talking about categorisation what I experienced the last few days from you was this:

    Based on your personal 'bus experience' (remember it was you who gave me this introspection) you showed me how you think about youth, especially the youth in western civilasation. You did not become tired of distributing from time to time pieces of asian wisdom. But what I must say is kinda shocking is the fact you are starting to point out now my nationality trying to tell me I am due to my nationality not able to see it 'right'. You know how I call that? I call that a straight 'ad hominem'.

    So that is where conformism (in more than one way)  leads to? To a bunch of ad hominems without any scientific base based on 'I sometimes get a bloody nose when going outside'.

    WE ALL GET A BLOODY NOSE FROM TIME TO TIME. DEAL WITH IT.

    And that is another thing I hate about being human: You are collecting bloody noses. And if you are not careful enough you end up hating everyone promoting every idiotic ideology you think might end your personal struggle.

    And by the way: Only with this simple trick (pointing on bloody noses) the Nazis were able to convert a lot of people for their column.

    So keep your composure. We are scientists and not an encounter group. Otherwise I will bring in daily questionaires about how everyone is feeling today and be your personal nurse Ratched.

    https://www.youtube.com/watch?v=OXrcDonY-B8&feature=youtu.be&t=1m38s

  • Sankar Sasidharan added an answer in Nanorods:
    What are the preparation techniques for getting aligned rod nanoparticles over a substrate like glass?

    Is it possible to get aligned nanorods during synthesis over a substrate ?

    What techniques could be adopted for aligned rods after formation ?

    Sankar Sasidharan · National Institute for Interdisciplinary Science and Technology

    @rajagopalan pandey : Thanks for the answer..! What i would like to grow are RePO4 rods in aligned manner over the substrate! 

  • Fabrizio Proietti added an answer in Oxidative Stress:
    What is the gold standard laboratory exam to analyze oxidative stress in organ transplantation?

    We are doing a research project in experimental intestinal transplant in swines and we are having some problems to find the best laboratory exam to see the oxidative stress after revascularization of the intestine.

    We have Malondialdeido, lactate, PACAP and PCR. Is there any other? What is the best to apply?

    Fabrizio Proietti · Azienda Ospedaliera Universitaria Senese

    Based on my experience F2-Isoprostanes is the best marker of lipid peroxidation. The measurements must be performed in mass spectrometry because ELISA kit shows crossreactivity with prostaglandins. About MDA I have some doubts because there might be some crossreactivity. About protein peroxidation Di-Tyrosine, Nitro Tyrosine are both good markers, but also AOPP could be used. In addition you could measure NPBI as catalyst in Fenton reactions.      

  • Marc Cowling added an answer in Business Cycles:
    What is the interaction between business cycle and banks credit risk or non-performing loans ?

    I am having some trouble to find the literature review that theoretically explain the relationship between macroeconomics factors (i.e., GDP, Unemployment, Interest rates ) and non-performing loans.

    If you help me I would really appreciate.

    Marc Cowling · University of Brighton

    I think that many of the answers relate to more aggregated and essentially large firm textbook views of the firm-bank lending market. In relation to SME lending we have some interesting stylised facts relating to economic cycles.

    1. SMEs demand less credit during an economic recession (a demand effect) as the set of viable investment opportunities diminishes.

    2. Banks raise the 'hurdle' rate (i.e less loan applications are accepted). This is a supply effect.

    3. As most loans are collateral backed (i.e the entrepreneur places firm or personal assets as security) this raises an issue for non-performing loans as asset prices are generally falling. Should a bank call its security in when it is worth less than when it was posted against a loan?

    4. The process by which banks assess loans becomes more focused on a smaller set of determinants (firm age, firm size, and the availability of collateral) in an economic recession.

    5. Banks often reschedule payments (repayment holidays) to established customers to ease their per period cash repayments in economic recessions.

    6. As the hurdle rate for loan acceptance is higher in economic recessions, the marginal borrower quality actually rises. In booms, as banks relax their approval conditions, they tend to over-lend and the marginal borrower is of lower quality.

    Hope this helps?

    Cheers, Marc

  • Stefan Axelsson added an answer in Intrusion Detection:
    How can i use KDD Cup 99 Intrusion Detection dataset ? can i use matlab or simulation (which one) or what and how?

    how can i use KDD Cup 99 Intrusion Detection dataset ? can i use matlab or simulation (which one) or what and how?

    Stefan Axelsson · Blekinge Institute of Technology

    The short answer is you can't. The underlying dataset itself is far too old and laden with artifacts to be useful for current intrusion detection research. The KDD cup 99 dataset is only a subset of the whole Darpa evaluation subset, so it's even only a part of an already flawed dataset.

    There are unfortunately no good alternatives, especially when it comes to labeled datasets. So, make your own and publish it. The research community would be much better served by that than yet another (flawed) study based on the KDD cup 99 dataset. (As a reviewer, we will critizise any study based on this or the underlying DARPA dataset mercilessly).