ResearchGate Q&A lets scientists and researchers exchange questions and answers relating to their research expertise, including areas such as techniques and methodologies.
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- Any researcher interested in working with transportation regulations and their impacts in megacities regarding developing countries?
Economic growth in metropolitan urban areas in developing countries is resulting in increasing demands from companies for goods and services. In fact, Governmental regulations aim decreasing mainly traffic congestion, although many others problems have emerged. Are these regulations enough? Which regulations are the most relevant/necessary in freight distribution system?
Thank you for your interest. Very interesting your work. Could you share it with us? Best regards, José
- How can I confirm presence of invisible gold in sulphides?
SEM study has confirm the presence of fine gold (2 micron). But I suspect presence of invisible gold as in chemical and EPMA data we are getting upto 600 ppm gold and silver values.
Proton induced X-ray emission (PIXE) technique can help you further and identifying the presence of both Au and Ag at a certain depth.
But such techniques may be available at BARC in India
Enclosing a nice article which may be of interest to you.
- How can I calculate thermal residual stress with ansys?
i am trying to analyze thermal residual stress in plastic deformation.
what i have been doing for until now is analyzing transient heat transfer during welding.
and I guess i can read these analysed file with 'ldread command'.
but the problem is that residual stress is not just affected by heat distribution at each time but is also affected by former stress .
so the problem is that with 'ldread command' i can just use analysed file of heat distribution of each time and i can just analysis heat stress of each time with that heat distribution but what i need is to connect each of stress in some way to analysis residual stress.
i will be so appreciated if someone knows and help.
The residual stresses in plastic and thermosetting resins is a rather involved problem. The description of it the method to overcome the difficulties to recover the residual stresses can be found in the papers below. I didn't find anywhere the prediction of residual stresses with equivalent accuracy as described in the following papers.
To illustrate the complexity , please, take into account that for amorphous non- reacting polymers
1) when stresses arise they may also relax , due the viscoelastic nature of polymers.
2) the specific volume at a point is a complex function of the heating/cooling rate at that point (the local volume variation is the real origin of residual stresses) (please see Ref. 3 below)
3) structural relaxation phenomena as those described above require a constitutive law for the kinetics of glass transition.
For reacting resins the chemical shrinkage phenomena and the kinetics of crosslinking reactions are superposed to the problematics expressed above. All these arguments are fully described in Ref 1-3 below.
1- Grassia L., D’Amore A. (2013) , “Calculation of the shrinkage-induced residual stress in a viscoelastic dental restorative material” Mechanics of Time-Dependent Materials Volume 17, Issue 1, February 2013, Pages 1-13
2- D'AMORE A, M. ZARRELLI, L. GRASSIA, F. CAPUTO (2006). Numerical evaluation of structural relaxation-induced stresses in polymers,. COMPOSITES. PART A: APPLIED SCIENCE AND MANUFACTURING, vol. 37, p. 556-564, ISSN: 1359-835X
3- ZARRELLI, M., PARTRIDGE, I.K., D'AMORE A (2006). Warpage induced in bi-material specimens: Coefficient of thermal expansion, chemical shrinkage and viscoelastic modulus evolution during cure. COMPOSITES. PART A: APPLIED SCIENCE AND MANUFACTURING, vol. 37, p. 565-570, ISSN: 1359-835XFollowing
- Is there any cut off value for Childbirth Attitudes Questionnaire which measure fear of childbirth??
The Childbirth Attitudes Questionnaire was validated in Farsi. it is recommended to use cut off value=28 for identifying fear of childbirth. I could not find any references indicating so. It is consisted of 14 items. Each item is scored 1–4 (1=not at all, 4=very much) with total points of 14–56.
Great question. I am not aware of any at the present time.Following
- How can i know the total number of transcript variant of a particular gene?
i want to study the transcript variants of a particular gene so before doing that i need to know number of known transcripts of concerned gene. is there any database or website?
For specific genes it is also still worth to check AceView http://www.ncbi.nlm.nih.gov/IEB/Research/Acembly/index.html although it looks not too much updated recently.
Anyway - if it is your particular gene of interest, try also methods independent of known isoforms, such as cufflinks on RNAseq - the transcription landscape is very often much more complex than standard databases...Following
- Is it possible to carry out a metaanlysis with the SPSS? I wonder if with some extensions can I make an analysis of size effect?
Personally I've never done meta-analysis using SPSS. There are specific software for this type of analysis. I suggest using Comprehensive Meta-analysis.Following
- What is the best software for calculating state estimation?
What is the best software for calculating state estimation?
I find the DIgSILENT PowerFactory 15.1.7 x86 in this link:
this software is state estimation plc of poya co.Following
- How to convert EEG raw data to frequency in order to obtain alpha and beta waves?
I am working with EEG signals using NeuroSky headset. I can get and plot EEG raw data but I need to convert these data to frequency and get alpha waves.
So I have some questions :
- What are the metrics of EEG raw data? Are they in time-domain or frequency-domain?
- When we want to do a Fourier Transform to get frequency domain, we need to give an specific function (e.g sin(x)) to calculate frequency. But when we are getting EEG data, we don't have any specific function. What we have is just some online data. How can I obtain online frequency domain using the EEG raw data?
- Is there any other way to get alpha and beta frequencies using Raw EEG data?
Actually I am looking for the answer of these questions:
- Are EEG raw signals in time-domain or frequency domain?
- To do Fourier Transform do we need the function who is generating the EEG signals?
- Is anyone doing research on micro-grids or mini-grids?
Looking for technical approaches for mini-grids worldwide, especially prototype and pilot project related,
which control strategy would be feasible and reliable. how about droop controlFollowing
- What are the steps to modify a database (thermodynamics and kinetics) to model a reactive transport system?
I want to model leaching of fly ash deposits using a reactive transport code, and the existing database does not include all of the reactions I need. Has anybody done modification on database? What are the steps and considerations? I know that convergence of the data is an important concern, but how should I care about it?
Concerning thermodynamic data, you can visit the webpage https://www.thermochimie-tdb.com. There is a database that, as far as I know, is being currently updated. Moreover, it gives you the data base in crunch format.
Once you have it and in case you still need, you can add species/solid phases trying to be consistent with data already in the database. In the webpage you will find information on how to select and introduce data.
Concerning kinetic data, things are not as clear. You can find the law you need in the literature or by yourself and then "translate" it to the Crunch format.
- I have a twelve year old boy with osteolytic lesions, pancytopenia and dry tap on bone marrow. What is your opinion?
USG ABD- Mild Hepatosplenomegaly
osteolytic lesions- skull, ribs, humerus and pelvis.
protein electrophoresis normal
Just out of curiosity: why the downvote ?
I mean: the downvote is not a problem but I'm rather interested in the reasons:
Answering Karthik question:
'In a young boy presenting with pancytopenia and osteolytic lesions. What would be your order of investigations.'
I said I would initially check:
1) CBC + PB smear + Standard Biochemistry (of note: LDH, Urate) + Electrolytes
2) Bone marrow aspirate (dry tap in this case) + Biopsy
@DOWNVOTER/other colleagues: please argument the reasons you disagree with this approach.Following
- Has anyone published a quantitative longitudinal study of the entire class of an elite university?
I would also be interested in any other large samples of graduates of elite universities over the sample's lifespan (or first 25 years, etc.)
Cambridge University has many colleges which keep tabs on their graduates. Trinity College Cambridge keeps good records, as far as I know. My daughter attended her 10 year anniversary, and there was a good crowd there, presumably drawn from the College lists.Following
- What human health care procedures are being used to aid sea turtles?
I recently learned about the adaptation of TPN to help sea turtles survive malnutrition, chronic debilitation syndrome (CDS) and other illnesses (http://blogs.discovermagazine.com/crux/2015/03/19/health-care-sea-turtles/#.VbJDdvmRLVt).
I know the invitro fertilization is used (and highly regulated) in sea turtles and human medications are also used. But are there other procedures also being adapted to help this threatened/endangered species?
A magazine I write for is interested in a story about this topic, so I'm looking for examples.
This is great information, Jennifer. Thanks. I'll watch for the paper.Following
- Do you know any tricks to decrease the ratio 260/230?
Hi guys! Im doing DNA extraction of fresh leaves with DNeasy Plant Mini Kit. But the result of ratio 260/230 is always around 2,39.
Do you know any tricks to decrease the ratio?.
Until now I have resolved this problem adding more ARNase when I have finished the extraction but I would like to know another way. Thanks!
Hi everyone, Thanks for all your advice.Following
- What is the best method for extraction of essential oils from black seed(Nigella sativa)??
crude extract of Ngilla sativa essential oilsFollowing
- How can I infer that two genes are paralogous using phylogenetic analysis?
I have two genes that are known to be paralogues (in bacteria) although I've never seen any work in the literature proving this assumption. I would like to conduct a phylogenetic analysis to prove (or not) this.
How could I do it?
I was trying to build a database with several sequences of each gene but one problem that I am facing and that I don't know how to deal with is during the alignment of sequences. The result of the alignment is giving me hundreds of sequences that are from the same specie, same genus or very closely bacteria. But to infer gene divergence or a duplication event I would need more distant related sequences, wouldn't I? I think it would be better to represent several classes and groups of bacteria to give me a trustful tree. How could I address this?
I only know the basis of phylogenetic analysis, so I really would appreciate your help.
Thank you Atai Rabby. I'll look carefully the paper and tools.Following
- Does anyone know the relationship between the correlation and flexibility of a protein?
I found an enzyme becomes more rigid after binding with another protein, however, it seems the correlation between CA atoms is stronger in the apo enzyme than in the complex? Are they conflicted?
what you are observing may be some real structure adaption to minimize entropy loss upon binding (e.g. higher correlations minimize entropy in the free state), which would be interesting, or it may simply be an artifact because you perhaps look at two systems of different size (free / bound) without the necessary correction.
I know this is shameless self-advertisement but you should have a look at this old paper: Grunberg et al. 2006: Flexibility and conformational entropy in protein-protein binding. PMID 16615910 PDF: http://biskit.pasteur.fr/use/publications/structure2006
We simulated 7 complexes and their free structures and I discuss in detail what kind of flexibility changes you can expect (interface more rigid, rest often more flexible after binding) and what kind of technical issues exist when you analyze this kind of data.
- Can anyone provide information on livestock culture (Broiler and Rhode Island)?
I have an idea to set-up an integrated model (Livestock and Aquaculture) in a small scale.
I agree with Bishwo Pokharel; in my country there is a concept about "Self-sustainable farms" that integrate all productions for the benefit of others.Following
- Is there any use in constructing/defining integration over (some subset of) the rationals?
I was working on 2 papers on statistics when I recalled a study I’d read some time ago: “On ‘Rethinking Rigor in Calculus...,’ or Why We Don't Do Calculus on the Rational Numbers’”. The answer is obviously trivial, and the paper was really in response to another suggesting that we eliminate certain theorems and their proofs from elementary collegiate calculus courses. But I started to wonder (initially just as a thought exercise) whether one could “do calculus” on the rationals and if so could the benefits outweigh the restrictions? Measure theory already allows us to construct countably infinite sample spaces. However, many researchers who regularly use statistics haven’t even taken undergraduate probability courses, let alone courses on or that include rigorous probability. Also, even students like engineers who take several calculus courses frequently don’t really understand the real number line because they’ve never taken a course in real analysis.
The rationals are the only set we learn about early on that have so many of the properties the reals do, and in particular that of infinite density. So, for example, textbook examples of why integration isn’t appropriate for pdfs of countably infinite sets typically use examples like the binomial or Bernoulli distributions, but such examples are clearly discrete. Other objections to defining the rationals to be continuous include:
1) The irrational numbers were discovered over 2,000 years ago and the attempts to make calculus rigorous since have (almost) always taken as desirable the inclusion of numbers like pi or sqrt(2). Yet we know from measure theory that the line between distinct and continuous can be fuzzy and that we can construct abstract probability spaces that handle both countable and uncountable sets.
2) We already have a perfectly good way to deal with countably infinite sets using measure theory (not to mention both discrete calculus and discretized calculus). But the majority of those who regularly use statistics and therefore probability aren’t familiar with measure theory.
The third and most important reason is actually the question I’m asking: nobody has bothered to rigorously define the rationals to be continuous to allow a more limited application of differential and integral calculi because there are so many applications which require the reals and (as noted) we already have superior ways for dealing with any arbitrary set.
Yet most of the reasons we can’t e.g., integrate over the rationals in the interval [0,1] have to do with the intuitive notion that it contains “gaps” where we know irrational numbers exist even though the rationals are infinitely dense. It is, in fact, possible to construct functions that are continuous on the rationals and discontinuous on the reals. Moreover, we frequently use statistical methods that assume continuity even though the outcomes can’t ever be irrational-valued. Further, the Riemann integral is defined in elementary calculus and often elsewhere as an integer-valued and thus a countable set of summed "terms" (i.e., a function that is Riemann integrable over the interval [a,b] is integrated by a summation from i=1 to infinity of f(x*I)Δx, but whatever values the function may take, by definition the terms/partitions are ordered by integer multiples of i). As for the gaps, work since Cantor in particular (e.g., the Cantor set) have demonstrated how the rationals “fill” the entire unit interval such that one can e.g., recursively remove infinitely many thirds from it equal to 1 yet be left with infinitely many remaining numbers. In addition to objections mostly from philosophers that even the reals are continuous, we know the real number line has "gaps" in some sense anyway; how many "gaps" depends on whether or not one thinks that in addition to sqrt(-1) the number line should include hyperreals or other extensions of R1. Finally, in practice (or at least application) we never deal with real numbers anyway (we can only approximate their values).
Another potential use is educational: students who take calculus (including multivariable calculus and differential equations) never gain an appreciable understanding of the reals because they never take courses in which these are constructed. Initial use of derivatives and integrals defined on the rationals and then the reals would at least make clear that there are extremely nuanced, conceptually difficult properties of the reals even if these were never elucidated.
However, I’ve been sick recently and my head has been in a perpetual fog from cold medicines, so the time I have available to answer my own question is temporarily too short. I start thinking about e.g., the relevance of the differences between uncountable and countable sets, compact spaces and topological considerations, or that were we to assume there are no “gaps” where real numbers would be we'd encounter issues with e.g., least upper bounds, but I can't think clearly and I get nowhere: the medication induced fog won't clear. So I am trying to take the lazy, cowardly way out and ask somebody else to do my thinking for me rather than wait until I am not taking cough suppressants and similar meds.
I seriously doubt that "the Cantor set can be very useful in elementary courses in mathematics of the sort researchers take," since it describes rather pathological phenomena, such as singular measures and singular functions that never appear in the more elementary mathematics the researchers need. Can you give an example of Cantor set being useful in elementary statistics?Following
- KH powder form supplier ?
Dear colleagues, I need to find a supply of KH in powder form. Does anyone know where can I find it ? I have tried SIGMA, ALFA, but they just got KH in mineral oil and KH in paraffin.Thanks in advance for your help.Following
- How to do Online Fourier Transform Using Online Generated Signals By an Uknown Function?
I have an online signal but I don't know which function is generating these signals. So is the Fourier Transform (e.g. Fast Fourier Transform) needs the function (e.g. Sin(x+2) ) who is generating the signal or it is possible to use Fourier Transform for some generated data without knowing which function is generating these signals?Following
- Should we hold people accountable for their mistakes?
Dear RG friends,
This is an important matter, for me as researcher and as human being. It is about errors and we know: "Errare humanum est, perseverare-diabolicum".
Human errors and the adverse events which may follow, are problems of psychology, systems thinking, behavioral sciences and engineering (in technical systems). Understanding, predicting, and modulating human performance in any complex setting requires a detailed understanding of both the setting and the factors that influence performance. The social cognition research on cycles of accountability clearly captures the complexity of the effects and demonstrates the naïveté of the belief that improving society only requires holding others accountable.
The “culture of blame” never worked. Why don't people just follow the rules, legislation, procedures?
My starting point in formulating this question was occupational and system safety, but I would like to have your (expert or personal non expert opinions) in a general sense of human accountability in various fields, activities and situations?
I think we should be accountable to our mistakes.........Following
- What are the advantages of partial least squares path analysis versus AMOS-LISREL type search algorithms?
Advantages of the two techniques when conducting SEM
Thank you Dr. Overstreet and Dr. Waddimba... Your answers are really helpful. They are highly appreciated. How can I cite your paper Dr. Overstreet?Following
- How can I report the ordinal regression?
Hi. I study on my master degree and I'm currently doing on my dissertation
I have some question. I think I will use a ordinal regression. However, I'm quite struggling on how to report this type of regression. I used ordinal data as a dependent variable. and the scale data as an independent variables. In the SPSS, I selected all independent variables as covariates and I quite not sure what exactly I should report. I saw many examples on the websites but most of them using ordinal variables as independent variables.
So anyone can help me or explain me on how to report this type of regression. or any textbook or journal that explain this
@Disna,i agree with youFollowing
- Why ltr retrotransposons are present in abundant manner in plant kingdom?
mechanism behind the abundance of ltr retrotransposons in plantsFollowing
- How to discard recombinant E. coli cultures and plasmids?
What is the proper way to discard the recombinant E. coli strains containing antibiotic resistant genes and also the isolated plasmid DNA.Following
- Opinions of dental teachers / trainers in dental colleges regarding the impact of e-learning?
Are we having consensus that as information technology evolves, the potential for continuing dental education will increase and e-resources will play an important role in future dental practice?
Dear Dr Davide
Ur point is apt..
Eye contact n teachers judgment on d spot to decide how to go about teaching is very imp aspect of conventional teaching.. and technology can be used as an adjuvant but not replacement.
. chalk and talk also boosts the confidence of teacher and student ..Both
PowerPoint presentations should be watermarked.. All material given to any student shud be "read only" uneditable..Following
- What statistical test do I choose when I have a categorical dependent variable and both categorical and continuous independent variables?
I am leaning towards Multinomial Logistic Regression, but I am still unsure.
I conducted a vignette/scenario study where participants were exposed to four fictitious scenario's consisting of two variables: tie strength and intimacy (these two variables are the conditions, so categorical). After exposure to these two variables participants answered questions on a continuous scale (4 variables) and a categorical scale. This latter categorical variable is the dependent variable. To make it more difficult, it is a ranking variable (i.e. rank these four media in preference) and has been split up into four variables (i.e. ranking face-to-face, ranking skype, ranking telephone and ranking chat; participants had to rank all these four media types from 1-4 according to their preference). So these four new variables are my dependent variables and are categorical (I think). What statistical test do I use in this situation? I hope I have been clear, it is kind of a complicated study :)
Thanks in advance!
You are welcomeFollowing
- How can I know if a protein is in a Inclusion body?
I'm working with a T.cruzi mitochondrion protein that has a 20 residues hydrophobic region. I'm using a CodonPlus strain and expressing it into a pET28a vector in LB media, 20ºC, 0.2 uM IPTG overnight. However, im getting only 1.3-1.7 mg/ml of protein and more than 70% of my protein is in my pellet.
How can I know if my protein is in a inclusion body or it is in association with the membrane?
Dr Nelson has given all you need. In addition to it I wish to tell, you can try various different strategies if the said protocol doesn't work (as it happens in certain cases). Urea, Guanidine Hydrochloride, high pH etc are few among them. For help try to check papers by Dr.Amulya Panda.Following
- Has any scientist tested the novel microglial-specific fluorescent CDr10a or CDr10b for live imaging?
I am searching for a specific label of microglia in live, in culture cells and explants.
I have read about the transgenic mouse lines expressing fluorescent green protein but are not microglia specific (they also label macrophages).
Do you know where I can get CDr10 and what is the protocol used?
I found a citation : Cheryl Leong et al. Chem. Commun, 50: 1089-1091 (2014)..If you ask this working group, may be they will offer you a testing aliquot.
If you like to do IHC I recommand the Iba 1- AB for microglia from Wako.