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  • Hadrien Louchet added an answer in Optical Networks:
    Which simulation tool can be used to simulate hybrid WDM-TDM passive optical network?

    I have designed one network and I would like to evaluate the performance of that network. Parameters are latency, average power consumption, number of required wavelengths etc. to serve that network. Which simulation can be used to determine these parameters? Thank you in advance.

    Hadrien Louchet · VPIphotonics

    Hello Amit,
    check this application example on the VPI website:

  • Nizar Matar added an answer in Bureaucracy:
    How might responsible decision making be encouraged?

    How might responsible decision making be encouraged?

    It seems universal and timeless that for any organization, people who 'rise' to positions of authority and management are very often ill-equipped to perform their functions.  They often are very vague or even clueless regarding the best goals of the organization. Being proficient at obtaining power does not appear to correlate well with knowing how to perform one's responsibilities. This is often seen in industry, government bureaucracy, politics, and I would suspect in laboratory management and in any other organization one might care to name. It's an unfortunate circumstance of the human condition. (Unfortunately I would also have to add irresponsible leadership in religious organizations in this problem as well.  We often do not "practice what we preach.") 

    At any rate, incompetent management can almost certainly come to mind in many research and related organizations.  The people who most need to listen and learn, don't.  A famous example of someone trying to solve this problem may be found in the odyssey of W. Edwards Deming in the last century. He did not have much luck in the US.

    So what can be done to encourage more responsible leadership?  I think that good  leadership has most often occurred at levels below that of the ones with the most control, and that this is a further frustrating factor.  It is very difficult to have responsibility and no authority to perform it. How do we encourage better management and decision making?  How do we encourage a more cooperative and less antagonistic environment, when people often take control because they are egotistical by nature?

    Though this seems an obviously universal problem, circumstances and emphases vary.  Perhaps some anecdotes (no names, please), though hardly a scientific study, may stimulate some ideas for creative problem solving.

    - Thank you.   

    Nizar Matar · An-Najah National University

    Great question, I must say.

    Reaching the positions of management (with given authorities) is usually sought after by many individuals using various means including deceit, affiliations, and connections to influential politicians or aristocrats. If some person becomes a "boss" by a devious method only, very low expectations will be envisaged if s/he is left alone to administer.

    The incompetent manager is usually the first to know about his/her incapability, so assistants are appointed to help. However, if these aides are appointed by the same deceitful way then the organization will be in real trouble.

    To cure the problem from its roots, any appointment for a boss ought to be ideally based on merits only. However, since such cases are real & not ideal then the smart efficient persons (even if they are few) will have an extra duty which ought to work on 2 fronts: one is remedial and consists of trying to change the environment from the bottom to the top with an eventual target of converting the management into apt leadership. The other one is revolutionary and consists of trying to remove the imposed boss by peaceful means without confrontation & relying upon logical visible evidences.

  • What is variance inflation factor and how can be accounted for?

    I know that variance inflation factor quantifies the severity of multicollinearity in an ordinary least squares regression analysis but I need to know practically how this should be implemented. 

  • What is the simplest Dipteran species to be rearing and obtaining many maggots at the same stage?

    Could you please tell me how to obtain a lot of maggots at the same stage to achieve a bioassay of a biopesticide against Diptera

    So, I need to get a big colony with ability to design a rearing method to separate maggots at the same age

    Galina. V. Benkovskaya · Russian Academy of Sciences

    Yes, house fly is the simplest species for rearing and testing pestcides .

  • What is the appropriate immunosuppressive therapy for MCTD children?

    I would like to know what is the appropriate immunosuppressive drug for treatment of pediatric mixed connective tissue disease (MCTD).

    I already know the following articles.
    1. Tiddens HA, et al. J Pediatr 1993.
    2. Nakata S, et al. Nihon Rinsho Meneki Gakkai Kaishi 1997.
    3. Mier RJ, et al. Rheum Dis Clin North Am 2005.

    By the way, our patient with pediatric MCTD has arthritis, and myositis-like symptoms are main.
    I believe that administration of methotrexate may be the appropriate treatment for our case.

    Any suggestions will be greatly appreciated.

    Hiroyuki Wakiguchi · Yamaguchi University

    Dear Donald,

    I appreciate your detailed description.
    Your suggestion is also reasonable.

    Thank you so much.

    Please see the following article about renal disease of pediatric MCTD.

    Ito S, Nakamura T, Yokota S, et al. Glomerulonephritis in children with mixed connective tissue disease. Clin Nephrol 2006; 66: 160-5.

    Pediatric MCTD is known to be associated with a higher risk of nephritis than adult MCTD. Membranous nephropathy and mesangial proliferative glomerulonephritis were common in pediatric MCTD. The hypocomplementemia observed in children with MCTD suggests the high frequency of glomerulonephritis, including membranous lesions.

  • How do I apply Box Cox transformations on a Repeated Measures ANOVA?


    I am performing a multivariate repeated measures ANOVA on insect counts from experimental trays.

    I have six months (repeated measures) of these counts and two of these months fail Levene's test of equality of variances (and are non-normal - one month has lots of 0's).

    Transforming the data for each of these two months separately using a Box Cox test brings them both into a normal distribution and, I hope, may solve the variance problem.

    However, how can I apply this? Presumably any transformations I apply to each month (repeated measure) should be the same? And, if I understand correctly, the Box Cox test is tailoring my transformation to the individual data set? And it wouldn't be correct to pool all months and transform that (which didn't work anyway).

    Have I misunderstood something about repeated measures ANOVA's and Box Cox transformations?

    Jacek Jamiolkowski · Medical University of Bialystok

    Also, I don't think it is right to apply different transformations to subsets of the data (months in your case), only transformation of the pooled data would be valid. Box-Cox transformation would also make results harder to interpret. Previously mentioned non-parametric approach would impede inference on interactions (as you concluded yourself).

    Therefore regression models designed for count data is your best bet. Good luck with your analysis.

  • Ilman Jais added an answer in Antenna:
    How I can bend microstrip patch antenna by CST to get the bending effect on the performances?

    I want to bend the the antenna because my antenna is a kind of flexible antenna. Could u please help me how I can bend this?

    Ilman Jais · Universiti Malaysia Perlis

    i am using CST 2014, also deployed same method as manimaran propose and its working very well.

  • Darshan Panda added an answer in Photobiology:
    Which of these light response curves corresponds with the highest photosynthetic efficiency and why?

    Please check the image and answer. Please explain the reason

    Darshan Panda · Central Rice Research Institute

    Does B has better photosynthetic efficiency at low light than A and C?

  • Cheick Thiam added an answer in Radioactivity:
    What is the mass number of the Radioactive isotope?

    What is the mass number of the Radioactive isotope?

    Cheick Thiam · Atomic Energy and Alternative Energies Commission

    You can find here all informations about Radioactive Isotope :


  • Jiri Sichtar added an answer in Living Donors:
    Does somebody have practical experience with OPU technique in live donor mares?


    I would like to ask some questions regarding technique of oocyte aspiration from live donor mares.

    The mares are sedated, without epidural anaesthesia. We are using 18G needle connected to syringe. We tried to flush the follicle several times (5-8). First, we used gentle pressure. Second we used rough pressure.  During flushing I was sometimes able to move with the needle/ovary to scratch the follicle which should better release the oocyte. Of course this was not the case in all mares. Our successful rate is for the present really low. I had the chance to work with the ovary from slaughter house, because I wanted to see what is happening with the follicle when I work with live donors and I regarding what I saw the pressure of fluid which we pushed back to the follicle should be really gentle.

    My questions are:

    1/Do you think we should focus on “scratching” the follicle every time (all size categories)?

    2/Do you think follicles can leak out from the follicle through the hole around the needle?

    3/Have somebody tried to inject hCG directly to the follicle and harvest the follicles some hours later?

    4/Is it better to rotate the ovary so I can reach all the >2 follicles or is it better to inject the needle through the ovary?

    Thank you very much for your answers.

    Best regards,


    Jiri Sichtar · Czech University of Life Sciences Prague

    Hi Juan.

    Thank you very much. 

    I was doing OPU just yesterday and we are perfect until "scratching" the follicular wall when the needle is injected. I think, that is the main reason we are getting so low numbers of oocytes. 

    Please, does somebody have experience with this "scratching"?

    Thank you,


  • Narasimhan Ashwin Kumar added an answer in Coating:
    How can I characterize coating of metal on metal oxide nanoparticles other than TEM?

    I would like to know different characterization techniques where we can understand the coating of a metal to a metal oxide nanoparticles. At least I wanted to know that the layer is coated on the surface of metal oxide nanoparticles.

    Narasimhan Ashwin Kumar · Indian Institute of Technology Madras, Chennai

    Thanks a lot for all your efforts in giving me valuable ideas... As many friends suggested to do XPS and TEM.. I will try both these techniques to determine the core and shell. 

  • Mohammad M Khan added an answer in Olfactory Bulb:
    What is the best method for counting BrdU+ cells, BrdU+ / DCX+ and BrdU+ / NeuN+ in the SVZ and the olfactory bulb?

    I'm performing immunohistochemistry with a treatment that is expected to increase in vivo neurogenesis in the SVZ. I would be really grateful if somebody suggested the best way to count cells and to analyze data.

    Mohammad M Khan · University of Zawia


    Both the doctors above gave good advice. I can brief it, if you are using DAB staining  you can use light microscope based stereology (Optical fractionator method) to count the single labeled cell, it can also be done manually just by taking pictures and counting it but, stereology is unbiased and more precise. If you are using immunofluorescence double leveling, in that case you  will have to use confocal microscope based stereology.  You will get good estimate of BrdU+ cells  in the olfactory bulb but in SVZ, you have to set your coordinates carefully. 

    Stereology is a costly business, there may be some centers/facilities doing it by charging a price. They have many in USA, but I don't know if your can find one in Italy, if your working there.

    Good luck

  • Is there anyone who saw such a pillow basalt from intra-oceanic seamount?

    The thin section is from a basaltic pillow within circum-Pacific accretionary complex. However, it is not typical basalt...

    Need help to identify the rock type. It will be perfect if you had saw such kind of rock before.

    Thank you.

    Mutum Rajanikanta Singh · National Geophysical Research Institute

    Dear Mingdao,

    Will you please show me the field photographs of your pillow basalts. 

  • Stephen Hammel added an answer in Plasmids:
    I need to extract plasmid from glycerol stock bacteria. After done with extraction Im unable to find any band on gel. May I know the reason?

    Molecular biology, cell culture, genetic, microbiology

    Stephen Hammel · University College Dublin

    Hi Deyvani

    Are you growing your bacteria in selective media e.g. in the presence of an antibiotic such as ampicillin? If not you may be selecting for non-transformed cells.

    Did you try quantifying your purified extract before running on a gel using a nanodrop or qubit? If you got a very low yield from your extraction it will be very hard to see any band on a gel.


  • Juan Luis Mateo added an answer in In Silico:
    In silico enzyme digestion of a eukaryotic genome?

    Hi, I'm trying to simulate MspI digested fragments from a eukaryotic genome, but all the tools I've found seem to be designed for much, much smaller sizes. Can anybody recommend a program or method?


    Juan Luis Mateo · Universität Heidelberg

    Hi Tauras,

    I use the restrict command from the EMBOSS suite (http://emboss.sourceforge.net/apps/cvs/emboss/apps/restrict.html). There is also an online version of it (http://emboss.bioinformatics.nl/cgi-bin/emboss/restrict) but for genome wide restriction the command line version will be better. For vertebrate genomes it will take only a few minutes.



  • Oswald Dirwayi added an answer in Decentralization:
    Any strategies to improve participation and accountability through decentralization?

    Best ways to promote participation and accountability through decentralization

    Oswald Dirwayi · Africa University

    From an African perspective and with particular focus on local governance decentralization we have applied the four Ps + C of participation (Planning, Priority setting, Producing and Paying + Consumption.(Kauzya, 2003). Basically it has been observed participation is very high at product consumption level.  Efforts to inculcate a sense of ownership at planning level should be strengthened.  We have applied community based planning approaches to motivate ownership at planning and priority setting. Results have been varied due to the mindsets which have been tuned towards dependency. The above should be applied in an environment of institutional strengthening or capacity building at local level. Local level institutions are the pillars of decentralization and they are the medium through which citizen participation, as Japhace says above "take hold of the development process" can be improved.

  • What are the advantages of using organic coagulants instead of Inorganic like Ferric Chloride and Aluminium Sulphate?

    I treat about 20 000 L of effluent before discharge aiming to correct the pH, Conductivity, reduce sulphates and chlorides to below 1500 mg/l. Reducing the COD as well to levels below 5000 mg/l. I have been achieving good results with ferric chloride as coagulant and reducing the sulphates, suspended & dissolved solids using lime. 

    I'm just interested in knowing the advantages of using organic coagulants, I do all my preliminary tests in the lab (jar tests) and in my pilot plant on site (treating 1000 L of influent).

    Kim Helleshoj Soerensen · Wabag Watertechnology Ltd

    It is obvious that in your case the advantage of using an Organic Coagulant will be that no salts will be added avoiding to increase Chlorides. You will on the other hand not achieve the pH reduction that you have by using FeCl3.

  • M. Adly added an answer in MPPT:
    What are the used MPPT methods in industry that can find the global maximum power in partially shaded PV systems?

    I am aware of all the methods available in the literature but I need to know which ones are used in industrial applications.

  • What is the chemical reaction happening while etching FTO (fluorine doped tin oxide) glass with Zn powder and HCl?

    I know that Zn reacts with HCl to form ZnCl2 and hydrogen gas,, however, I couldn't understand how this reaction removes FTO from surface?

    Dipak Vijaykumar Shinde · Pohang University of Science and Technology

    Wow, this is interesting! Thank you for the answer Yomen.

  • Dipendra Gautam asked a question in Earthquake:
    How much is the acceleration time history representative for ground response analysis?

    Some measurements during Nepal earthquake were obtained on 3rd storey of building. How can we do correction for concrete? Or simply this is good enough for ground response analysis?

  • Levin Dieterle added an answer in Comsol:
    Does anyone know about piezoelectric device and MEMS physics in Comsol?

    I have a piezoelectric cantilever and I want to apply a (9*sin(2*pi*f0*t) mechanical vibration (shaker) to it.

    Levin Dieterle · VEGA Grieshaber KG


    I think the value "t" is not defined in frequency Domain. Just apply "V0" as Signal, which will be varying with the frequency f.

  • Barry Turner added an answer in Reputation:
    How do you determine whether a news source is reputable? Or a news story is reliable?

    We are thinking through some of the problems in distinguishing reputable news from phony ones. What might give you a clue that an online story you are reading is bogus, fake, or unreliable? We'd appreciate examples of what appears to be a reliable news source and what doesn't. Worldwide. Any language.

    Thanks so much! VR

    Barry Turner · University of Lincoln

    We have to assume that most news, while not being phoney is biased to an extent that it is not fully accurate.  News tends to be presented, now matter how 'unbiased' the source claims to be from a perspective of the culture in which the news provider is based.  

    This can be excellently observed in watching the reports on the multiple wars in the Middle East.  The BBC portrays it from the perspective of the modern democracy (not necessarily as benign as westerners often like to think).  RT presents it from a purely chauvinistic Russian perspective and even Al Jazeera, purporting to be the Middle eastern view adopts a capitalist, corporate view of a minority in a geopolitical zone with a vast range of cultures, political and religious belief systems.

    News is biased because people are biased.  British and American newspapers are deliberately biased in order to pander to their readership.  Many readers are less concerned with the accuracy and veracity of news stories than the pandering to their prejudices.  

  • Can we use median filter for multi-scale edge decomposition ?

    Median filter is generally used to remove salt and pepper noise but it comes under the class edge preserving filters like bilateral filter, guided image filter and Local lapalcian filters etc..,

    As like above filters can we use Median filter to separate a given image as base and detail layers for the purpose of detail layer manipulations.??

    Nasim Nematzadeh · Flinders University

    Definitely we can...This was Marr's idea at first I guess :-)

  • Grzegorz Karoń added an answer in Bluetooth:
    Bluetooth traffic detectors - what are your experience?

    What are your experiences in use and research of Bluetooth devices (cellular phones, on-board units and stationary installations) as measurement or monitoring of traffic? Is it really useful for traffic monitoring or traffic measure? Is it really useful for transportation modelling?

    Grzegorz Karoń · Silesian University of Technology

    Dear Wim, you are right, this technology is rather for monitoring and not for collecting useful data for modeling/measuring of traffic flows. But maybe someone has experience with comapring data from bluetooth and otner sensorc, like loop detectors or video detectors?

  • Choen Krainara asked a question in Organic Agriculture:
    What is the current and future marketing prospect for organic agricultural commodities regionally and globally?

    Global marketing prospect for organic agricultural commodities.

  • GC-MS analysis of natural products, How it's possible to have two different retention time in the GC-MS spectra of the same compound?

    For example I have at 19.10 min carvone and 21.86 min also for carvone????? I find some articles with these kind of ......

    If at 15.8 min I have a compound followed by the same compound 16.5 min in the same spectra, this mean that the compound was to concentrated, or the separation failed? 

    Look at Fig. 4 and the corresponding sample table.

    Mohammad Nazrul Islam Bhuiyan · Hokkaido University

    I think, it is possible. One may be d-Carvone or (4S)-(+)-carvone (main constituent of caraway (Carum carvi) and dill (Anethum graveolens) seed oils ) and other l-Carvone or (4R)-(−)-carvone (spearmint odour and is the main constituent of spearmint (Mentha spicata). So, different retention time in GC-MS column. Both are the main sources are essential oils and identified by GC-MS.

  • Nella Roccuzzo added an answer in Slurry:
    What is the best cell disruption technique for microalgae?

    After the harvesting of microalgae grown outdoors, what is the best cell disruption technique and does it work on dry powder or slurry form?

    Nella Roccuzzo · The University of Sheffield


    I work with Chlorella Vulgaris and I found that either microwave or sonications do not work well. So,  I use a solution 30% triton x-100 in ethanol to lyse the cells,  then incubate at 100°C for 5min and finally centrifuge at 13400rpm for 2min to separate supernatant from debris. 


  • Rafał Szabla added an answer in Atoms:
    TD-DFT coupled to PCM in Gaussian09; why is the excitation energy is even lower than ground state?

    I am using (TD)CAM-B3LYP/6-31G* coupled to the SMD solvation model to calculate the energy of excited states with partial or complete charge transfer character in a system of almost 100 atoms (mainly carbon atoms). I use the externaliteration keyword as implemented in Gaussian09; therefore I am using the State-Specific approach.

    The system I study is a dye-sensitized solar cell; therefore it can be divided into a donor and an acceptor fragment. The orbital HOMO is fully located at the donor, and many other HOMO's and LUMO's are localed at the acceptor fragment. As a result an excitation HOMO -> LUMO turns out to lead to an intramolecular charge transfer state. Here some results:

    Excitation HOMO -> LUMO

    gas-phase = 3.47 eV and 48.1 debye

    nonequilbrium solvation = 1.04 eV and 53.5 debye

    equilibrium solvation = -0.97 eV and 56.5 debye

    So, despite the increasing of the dipole moment is reasonable the excitation energy is strongly understimated, it is even below the ground state; how come?

    Any help or info would be well appreacitated,

    Kindest regards,

    Juan Pablo

    Rafał Szabla · Institute of Biophysics ASCR

    Hi Pablo,

    The problem with linear response methods like TDDFT is that they can sometimes give you negative excitation energies. I observed this multiple times when using ADC(2) and CC2 and the principle of getting the excitation energies in TDDFT is very similar.

    I am not surprised by the outcome of your calculation. First of all, as your probably now, the equilibrium calculation means that you relax your reaction field (implicit solvent) with respect to both states and substract the energies. Since your excited state is of charge transfer character, it is much more polar than the ground state and what follows it is much more stabilized by strongly polar solvent. This may actually result in negative excitation energy. Though, it doesn't mean the result is physically correct - it is just something I would expect.

    However, if you are interested in vertical excitation energies, you should not ever perform equilibrium calculation. The nonequilibrium scheme means that your implicit solvent is divided into two parts: fast part and slow part. Making things easy -slow part is supposed to mimic the positions of the solvent molecules and fast part somehow represents their polarizabilities. Since electronic excitation is practically a sub-femtosecond event, the solvent molecules have no time to redistribute, and only their polarizabilities react to the vertical excitation. Your excitation energy is significantly red-shifted, since the electric dipole moments of the ground and excited states will be most likely parallel and have the same directions. As a result the fast part is still sufficient to compensate for this modest change in the magnitude of the electric dipole moment and you get a red-shift in the spectrum.

    Your red-shift in nonequilibrium solvation scheme is, however, quite significant. If this is something that you don't expect, there can be several things you can try. In reality the nonequilbirum solvation for electronic excitations is never perfect with linear response methods and it often falsifies the results. A wave function method like CASPT2/CASSCF should give you much more reliable solvatochromic shifts (you can find such a scheme in Molcas program). In this particular case your system is probably too large for CASPT2/CASSCF. In the case of TDDFT, you can perhaps have a look at some works by Benedetta Menucci - she did a lot of developments in the field. I can't give you the exact references immediately, but I remember her mentioning during a presentation, that sometimes addining some crucial explicit solvent molecules helps in obtaining more reasonable results. You can certainly find something about it in her publication record:).

    Another problem can be TDDFT itself, which might have some problems in describing your system... Since you have a CT state you can try the range separated wB97XD functional (available in gaussian), and maybe your results will be a bit better.

    Good luck,