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  • Feng Shi asked a question in Laplace Transformation:
    Why the z-transform does not follow the same form as the Laplace transform?

    both Laplace and z-transform use the whole complex plane to move from time domain to complex exponential s-domain or z-domain, but z-transform has a different looking from the Laplace, my question is that why z-transform doesn't take the form, for example as the one in the attached image (an imagining one)

  • Palani Kumar added an answer in FLUENT:
    Can anyone know haw to calcule time averaged values of LES and turbulent dissipation rate from fluent?


    I have a question similar to above question. I run LES for 1000 time steps and I save my fluent files every 100 time steps. I have 2 questions: 1. I would like to calculate turbulent dissipation rate. However, it is not available in fluent. Does anyone know how to calculate it in fluent? 2. I would like to calculate average value of a parameter lets say fluctuating velocities from those fluent files. is there a way that fluent opens all those files that I save in different time steps and take the average of those and give me the averaged value?

    Thank you,

    Palani Kumar · Andong National University


    For calculating time averaged value, follow the steps below.

    1. Running simulation for 2-3 flow scales (flow scale = domain length / fluid velocity).

    2. In the "run calculation" panel, enable the option "Data Sampling for Time Statistics" and continue running for another 2-3 flow scales. You will be able to plot contours of time averaged data.


  • Arunkumar Rengaraj added an answer in Sodium Alginate:
    Does ph have any effect on posrosity of sodium alginate?

    Best range of sodium alginate pH for enzyme encapsulation, such that its not too exposed or too trapped to react.

    Arunkumar Rengaraj · Inha University

    pH plays important role in the gelation process and there is no constant pore size for enzyme entrapped.It vary based on your enzyme (size,charge) and the reaction condition.I hope u need to optimize some variables,then only u can be sure what pH u required

  • Semih Can Akıncılar asked a question in CRISPR/Cas:
    Does anybody have experience to target lncRNA for silencing?

    Hi, we have novel lncRNA and we want to knock it down by CRISPR CAS system. However 80% of the sequence (starting from 5' site) is overlapping with an other coding gene in other strand. I am afraid that any manipulations around will affect coding gene also. Does anyone have done this kind of work?

    Thank you in advance.

  • Trang Nguyen added an answer in Nuclear Proteins:
    How can I detect only nucleus protein instead of both nucleus & cytoplasm?

    Dear all,

    My protein stays in the nucleus and in the cytoplasm of the cancer cell, but I concern only nuclear immunoreactivity. Can I detect a protein of interest buy using indirect staining for flow cytometry?

    Thank you all.

    Trang Nguyen

    So many thank for your suggest Ms. Loise.

    I didn't use this kit. But I wonder if I detect another surface marker together, this kit can do.

  • Paulo Magno Martins Dourado asked a question in Biochemical Markers:
    Can plasma C-reactive protein (CRP) be used as a screening tool to select among low-risk patients to stratify Coronary Artery Disese (CAD)?

    The high cost of diagnostic methods, even of biochemical markers, limit many of the tools necessary for the diagnosis of CAD, especially if we consider the group of low-risk patients. Can CRP be a cost-effective strategy, as some studies have shown, to stratify these low-risk patient groups and separate which should effectively continue the investigation to elucidate the presence of CAD?

  • Editha Cagasan added an answer in Rice:
    How can we effectively control rice stem borer?

    It's rice harvest season here in Leyte, Philippines and many farmers have been complaining of a very low harvest because of stem borer infestation. The hybrids planted later in June this year are the ones highly affected.

    Editha Cagasan · Visayas State University

    Thank you very much Sir, this article is very informative.

  • Robert Marks added an answer in Legal History:
    Where in 1853 was the first mention of prohibition with a capital P?

    There are a number of sources on the Internet indicating that the word Prohibition, meaning forced alcohol abstinence, was first used in 1853 in America, perhaps in Maine. All of the sources appear to refer to each other. Exactly where and when was the word Prohibition first used?

    Robert Marks · University of New South Wales

    Glad to see my 1990 article is still being quoted. 

    The first use of the phrase "prohibition of alcohol" in any Australian newspaper appeared in the Melbourne Argus of 23 June 1859, where the Maine Act is mentioned, at

    The first use of the phrase "Prohibition of alcohol" (with a capital P) appeared in the Gawler Bunyip of 10 July 1896, at

  • Anthony Foris added an answer in NMR Spectroscopy:
    How can I differentiate ester and acid carbonyl in a polymer network by C-13 NMR spectroscopy?

    Thanks in advance.

    Anthony Foris · Dupont, Retired

    In case there is any confusion about "shielded vs. deshielded resonances" as mentioned above, please see attached.

  • Teresa S Johnson added an answer in Public Health:
    Can anyone guide me to an exemplar model that integrates postpartum clinical and public health services?
    • From my research and clinical care experiences, it seems like clinical and public health programs exist in silos. I am looking for evidence-based interventions to promote optimal population-focused inter-conception care in 'high-risk' populations of mothers.
    Teresa S Johnson · University of Wisconsin - Milwaukee

    She will be reviewing prenatal assessments that all women who are interested in home visitations in the county complete. This will provide information about whether or not they participated in home visitation. The home visitation program has a inter conception intervention. She will have the length of time between birth of the last child through conception with this next pregnancy. The goal is > 16 mos.

  • Yoshihiro Yonekawa added an answer in Stem Cell Therapy:
    Does anyone know about stem cell therapy for grade 5 retinopathy of prematurity?

    A 3 month old male infant with grade 5 retinopathy of prematurity. Is there any hope for stem cell therapy? What about available specialized centers in this field? 

    Yoshihiro Yonekawa · Associated Retinal Consultants, William Beaumont Hospital

    Hope the surgery went well. Surgery or observation are the only options currently for Stage 5 ROP. Ehab El Rayes in Cairo probably has the most experience in your area. At ARC/Beaumont in the US, we're a busy international referral center for pediatric retina surgery, where many pediatric retina surgeons have trained (including Dr. El Rayes and Dr. Wong mentioned above). Always happy to consult electronically.

  • Carole Rushton added an answer in Positive Psychology:
    Can you help me with my mixed-methods research dilemma ?

    I am beginning a research project where I conduct 3 to 4 individual interviews (30minutes) with older subjects in nursing homes suffering from depression. In line with positive psychology, we will be discussing difficult moments/periods in their past and exploring the positive qualities/ressources/traits that enabled them to get over these difficult periods. The hypothesis is that these sessions will lower depression and increase positive affect. The scales to measure this are the CES-D depression scale, the Positive and Negative Affect Schedule and Diener's Satisfaction with Life scale. Measures will be taken pre and post intervention and then at 7 weeks to see how well the results were sustained.

    One problem I have is that I suspect that because they are depressed they will have difficulties identifying the positive qualities they had that enabled them to get over the difficulty. I want to avoid orienting the discussions or being the one to point out the qualities they demonstrated : ideally I should only guide them to see these aspects themselves. Does anyone have a recommendation for a good practical qualitative research methods guide that could help me with this aspect of the interviewing ?

    Problem 2 : what do you think of the scales I've chosen ? The goal being to pinpoint that it is the effects of the intervention (i.e. identification of positive traits in past situations of adversity) that lowers depression and increases positive affect.

    Problem 3 : I recognize the biais that the interviews and the rapport created between myself and the participants in this therapeutic context could in and of itself be the factor that lowers depression and raises positive effect. I do not see how to distinguish in the results the effects of the intervention and the therapeutic relationship. Does it seem feasible in a thesis research project to simply identify this biais ?

    I truly would appreciate your help with this. Unfortunately my thesis professor has not been able to give me enough guidance with this dilemma. Any recommendations are welcome !

    Thanks in advance


    Carole Rushton · Griffith University

    Hi Holly,

    Let me reflect back to you what I understand your project to be about.

    But first...

    The purpose of the study is what?

    The rationale for the study is what?

    Design: A sequential mixed-methods evaluation using an experimental approach will be conducted using quantitative data gathered by way of survey and qualitative data gathered by way of interviews.

    The intervention is aimed at addressing depression among older people in residential care. The intervention involves what?

    The quantitative component of the will use pre-post testing to test the hypothesis which is? (refer back to purpose and rationale for doing the study) using statistical analysis? [matched pair] Not sure if a control group is the best way to go?

    see https://www.youtube.com/watch?v=cbGmJBIbVG0

    The qualitative component of the outcome evaluation will use [which] qualitative analysis [thematic/content] to explore what?

    I wonder if addressing the above would help you to clarify what you are doing and why?

    Hope this helps.

  • Avula srinivasa rao added an answer in Chemical Biology:
    How to remove DMF completely after completion of reaction ( DMF used as solvent in reaction)?

    I proceeded one reaction with DMF used as solvent, after completion of reaction i did workup with water and ethyl acetate system. I observed some amount of DMF still present in the organic layer. can you please give  some suggestions how to remove DMF completely.   

    Avula srinivasa rao · Southwest University in Chongqing

    Thanks to all for their valuable suggestions. 

  • Farah fadwa ben belgacem added an answer in Pyruvate Decarboxylase:
    How can I find an unknown gene in known genome?

    I have a wild type streptococcus and the whole genome of it sequenced and recorded in NCBI. But there is a few genes of it identified. I want to find pyruvate decarboxylase sequence in this strain but it's not identified. How can I find the sequence of this gene? I was find the same gene sequence from other organism and BLAST it to whole genome sequence of my strain but I cannot find my gene.

    Farah fadwa ben belgacem · International Islamic University Malaysia

    In case of known genome you can align and compare your genome with all the genomes of this species and then use Conserved domaine database to find conserved domains sequences CDS of pyruvate decarboxylase to find your gene of interest. 

  • Nilesh Manubhai Meghani added an answer in Nanotechnology in Drug Delivery:
    Are there pharmacological techniques to utilize unique mechanical properties of cancer environment in order to specify drug delivery to tumor cells ?

    Tumor differ from normal tissue in their mechanical properties , stroma of breast cancer as example is stiffer than those of normal tissue , now do we have available pharmacological technique or amenable to develop that can be activated or release their contents at degree of stiffness exist in cancer but not normal tissue.

    I think that this unique property may offer a way for drug delivery specification at least theoretically.

    However , i know little about about utilize of nanotechnology in drug delivery and diagnosis but i think it can be utilized in this situation.

    Nilesh Manubhai Meghani · Ajou University

    In my view, most of the drug delivery systems have targeted the cancer by means of the ligands specific to the tumor surfaces. For example, folic acid for overexpression of folate receptors in colon cancer. Nanoparticle based systems have advantage of the leaky vasculature of the tumor enviornment and thus having the benefit of enhanced permeability and retention (EPR) due to particle size and also ligands they carry on their surface help to target the cancer. I am not quite sure that other mechanical properties can have a role in delivery of a drug for cancer.


  • Ariel Linden added an answer in Statistical Software:
    Does anyone know some statistical test to perform in this situation?

    I am working with caged fish in different polluted areas along a river and I designed a bifactorial experiment: 4 locations (A, B, C, D) and 2 hidrological stations, wet and dry), therefore I have 8 different  treatments. At the end of the experiment most of fish survived but in one treatment (D-Dry) all the individuals died. When was carring out the statistical analisis of the measured variables  eg. Acetylcholinesterase Activity (bifactorial ANOVA with interaction), all statistical softwares that I've been using, showed me an error because of this treatment without  data (just one location in one hidrological station, in the other station there is data).

    I hope someone can help me,

    thanks in advance

    María Laura

    Ariel Linden · University of Michigan

    Hi Maria,

    First off, I am not sure why you are using an ANOVA when your outcome is survival, or more generally, a rate. This is the wrong model for such data. You should probably be  using a count model (Poisson, negative binomial, etc.). Moreover, you could further consider using a multilevel model with sites as the random effects.

    All that said, you are likely getting an error because you are making comparison between two groups in which one of the groups has 100% of the cases (or outcomes) determined. As a test, you could recreate the outcome for that group and replace a few of the values with zero (that is, change the scenario where instead of 100% of cases died, only 90% of cases, died). You will most likely get the model to produce output. That said, this is still the wrong model to be using.

    I hope this helps


  • Luan Hong Duong asked a question in Software Technology:
    How can we get definitions in relation to BIM right?

    As far as I see, research on BIM often uses terminologies in many different ways. Some use BIM tools and BIM process. Others prefer BIM compatible software/technologies and BIM methodology. For my understanding, BIM tools and BIM compatible software/technologies are the same aspects. Also, BIM process and BIM methodology are likely to share many points in common.

    How are BIM experts using these terms?

  • Robin Braun added an answer in Software Defined Network:
    Will software defined networking or autonomic computing be better a solution for a Next Generation Network?

    Software defined networking able to controls varies brands driven snmp and it will be lead by central software management. Is it better compared to autonomic networking or the concept are equally identical.

    Robin Braun · University of Technology Sydney

    This is a rather confused question. Let's clarify it

    1. Software Defined Networks (SDN) and Autonomic Computing (AC) cannot be compared. They are completely different things.
    2. SDN is a way of abstracting the physical infrastructure of a network so that it can be generalized to be able to provide connectivity without having to get into the network elements themselves. In other words, SDN allows a network infrastructure to be able to behave in much the same way as a computing infrastructure does with an operating system and applications.
    3. On the other hand AC is a concept where a system is able to parametise itself, and learn how to do this itself.
    4. It turns out that SDN holds out the hope that networks can be made to exhibit some Autonomic behaviour. 

    SNMP is a whole different thing and cannot be put in this mix itself. It is a protocol for managing agents to connect with network elements. It is just nowhere similar to SDN or AC.

  • Shukla Acharjee added an answer in Fluvial Geomorphology:
    Are catchment, watershed and drainage basin synonymous? If so, what are the criteria to delineate a drainage basin?

    Drainage basin is a place of work for fluvial geomorphologists not only as a geomorphic unit but gets attracted by many researcher also due to its interdisciplinary nature. Therefore, the delineation and mapping of it is the foremost work of further researches. The shortfall of narratives on methodology to delineate and mapping a drainage basin/catchment preludes the scientific society to make a common consensus or standardisation of this vital task of map making in broader perspectives. Please put forward your views & comments...

    Shukla Acharjee · Dibrugarh University

    to prepare a drainage map, kindly digitize the finger tip or first order stream, then second order and so on. feed the attribute table. clean and build your vector layer you will get not only your streams with orders as a vector layer but also the total number of first order stream and others separately and also the length of each stream order in the attribute table. now since you have dizitized all the stream of a basin or sub-basin or water shed or sub or micro watershed of your AOI your can easily delineate the basin boundary as a polygon vector layer. after getting the all these info you can calculate all other morphometric parameters for your study. regards

  • Seongho Jeon asked a question in Scherrer's Equation:
    Why XRD particle size is bigger than TEM or Chemisorption?

    I've made Pt on metal oxides or carbon supports catalysts, than I check particle size by using XRD with Scherrer equation. So, I've got around 30~40 nm Pt particle by XRD. But normally it's very undesirable data.

    on the other hand, I've co check with CO Chemisorption and TEM image. It found 2~4nm size Pt. It is well known data that normally impregnation method. Pt metal was impregnated about 5 wt %. 

    So. Here is my question. Why XRD particle size by Scherrer equation is bigger than other method that Chemisorption method or TEM image. 

  • Abdul Ghafar Wattoo added an answer in Organic Semiconductors:
    Is band gap tuning only in organic semiconductors or in inorganic semiconductors also?

    I would like to know about the band gap tuning in organic semiconductors as well as inorganic semiconductors

    Abdul Ghafar Wattoo · Ningbo Institute of Materials Technology and Engineering, University of Chinese Academy of Sciences, China

    Yes, possible in both

  • Robin Braun added an answer in Wireless Sensor Network:
    Gaussian Source, Noise and Distribution for wireless sensor network ?

    in my recent work for wsn , i faced some questions about what is the differences Gaussian Source ,Gaussian  Noise,and and Gaussian Distribution nodes for wireless sensor network . and how i can implement that in matlab ?

    Robin Braun · University of Technology Sydney

    Start with Gaussian Noise

    1. This is noise that is produced by naturally occurring phenomena and is random and its magnitude is distributed by the Gaussian probability function.
    2. That is, when you sample it, its amplitude is Gaussian distributed.

    Now go on to the Gaussian Source

    1. This is some physical source that produces the noise described above.
    2. Generally this is a collection of naturally occuring sources such as radio noise measured by their noise temperature

    Now Gaussian Distribution

    1. This is a mathematical model that enables you to calculate the likelihood that a sample of the noise will be between two specified values 
  • Alveta Vanessa Reese added an answer in Health-Related Quality Of Life:
    I desperately need help recruiting adult cancer survivors for my doctoral dissertation. Does anyone have ideas?

    Hello! I am currently working on my dissertation and am having a really hard time finding participants to complete my survey.   I am conducting research on health-related quality of life among cancer survivors, specifically adult survivors, aged 18 years and older.   All cancer diagnoses will be considered and there is no limit to how long individuals must have been in remission.  My questionnaire is posted in many Cancer Support Centers in the Chicago area, as well as in Ohio. Additionally, the link to my research can be found on the National Cancer Institute Facebook page. My survey is accessible online via SurveyMonkey and takes about 20 minutes to complete a short demographic tool and a 41-item self report measure.  Currently, I am well below the sample size I need to obtain significant results, so I am reaching out to all the avenues I am aware of.  Please let me know if you have any connections to this specific population (any cancer type) or recommendations of organizations that would be open to disseminating my information to their participants. I am looking forward to any feedback and appreciate your consideration! Thank you in advance!!

    Alveta Vanessa Reese · Tuskegee University


    Have you tried the American Cancer Society Support Network, The ONS nurse support site, ASCO ( American Society of Clinical Oncology) Susan G, Komen Foundation

  • Gomaa A. M. Ali added an answer in Composites:
    Why does particle size increase by the introduction of graphene?

    I have synthesized CeO2 and CeO2-Graphene composite in identical conditions but the particle size of CeO2 nanopartilces in composite is found almost double than that of bare CeO2 nanopartilces. Can anyone suggest the possible reasons behind this?

    Gomaa A. M. Ali · Al-Azhar University

    Actually this is unexpected, suppose the particles size decreased as graphene sheets prevent particle agglomerations 

  • Khalid El BAIRI added an answer in Metastasis:
    How to induce metastasis in vitro?

    I am searching for protocols inorder to induce metastasis in vitro. I need to know how long will the procedure take.

    Khalid El BAIRI · Université Mohammed Premier

    Here are some protocols : http://link.springer.com/search?query=cancer+metastasis&facet-content-type=%22Protocol%22

  • Kenneth M Towe added an answer in Global Warming:
    [Global Warming] Mitigation and Adaptation: which is more important ?

    Most climate issues' stakeholders do not deny that, we need to develop a "integrated series" of mixed policy, both to reduce greenhouse gas emissions (mitigation strategy), but also to deal with the consequences of global warming (adaptation strategy). The biggest divide is over which strategy should be paid more attention to.

    My dear peers, what do you think about it ? Any contribution is greatly appreciated.

  • Vaibhav Mantri added an answer in Marine Aquaculture:
    Are there any studies pertaining to the stability of aquaculture structures in open sea?

    I would like to know if there are any studies related to structural stability of different aquaculture structures (preferably different shapes) in open sea, especially simulations of wave directions, speed etc. If some one can provide me literature it would be of great help.

    Vaibhav Mantri · Central Salt and Marine Chemicals Research Institute

    Many thanks Matthias!

  • Aaron Seng Wai Wong added an answer in EEGLAB:
    How can I import events from BioPac into an EEGLAB event structure?

    I need to replace the event structure in Brain Vision EEG data with BioPac event information, and can't figure out how to do so. I tried importing the data into EEGLAB via the import functions plugin with no success. Any guidance would be greatly appreciated.   

    Aaron Seng Wai Wong · University of Newcastle


    BIOPAC seems to have special tools to read their file formats. As shown from their FAQ:

    My suggestion is to follow something in the lines of this:

    But fortunately, some of the steps are already written and available online.

    1. Read the data into matlab:

    2. Convert the data into the format required, above is the format format suggestion for FieldTrip, but for EEGLAB you can use the following site to obtain the structure.
    E.g. Insert Your Epoch/event information into EEG_biopac.events
    Some matlab code may be required to achieve this task.

    3. Merge with your Brain Vision Data, (overwrite the BrainVisionEvents)
    EEG_fromBrainVision.events = EEG_biopac.events;

    Good luck!


  • Julie Crudele added an answer in Protocols:
    Is it posiible to culture two types of cells together? does anyone have such experience before ?

    protocols to culture two types of cells together? what is the limitations and how to overcome them ?

    Julie Crudele · University of Washington Seattle

    I've done transwell culturing, where the two cells don't directly mix, but soluble factors can pass through the membrane.  Do your cells need to be in direct contact with each other?

  • Sergiy Yershov added an answer in Computational Fluid Dynamics:
    I need some resources on Upwind Scheme used in modern CFD?

    Actually i want some well organized documents on Upwind schemes that are used in modern CFD e.g. Flux splitting,Godunov scheme, TVD, Hartel Lax van Leer(HLL), etc. A book on techniques used in modern CFD will be perfect. I read the book 'Computational fluid dynamics: The basics with applications' by John Anderson. He wrote a very little about the state-of-arts used in modern CDF in Chapter 11 in this book. I do some googling but all the documents on these topics are discrete and quite hard to capture. 

    Thanks in Advance.

    Sergiy Yershov · http://sergiyyershov.com


    You can try "Riemann Solvers and Numerical Methods for Fluid Dynamics" by E.F.Toro.

    But he does not consider modern ENO/WENO schemes, which you can find in

    "Essentially non-oscillatory and weighted essentially non-oscillatory schemes for hyperbolic conservation laws"  by Chi-Wang Shu (https://math.la.asu.edu/~gardner/ENO.pdf)