ResearchGate Q&A lets scientists and researchers exchange questions and answers relating to their research expertise, including areas such as techniques and methodologies.
Browse by research topic to find out what others in your field are discussing.
- How can you manage open-coding without losing too much content in qualitative content analysis?
I have issues in relation to managing my first QCA. I am using an inductive approach, with analysis focus groups.
While open-coding, I feel that a lot of the content is lost. Does anyone have any advice?
Write your "main question" on a page and place it in front of yours ( focused on the Topic) when coding.Following
- How to get the volume of elements in UMAT?
I want to average the strains/stress in the reduced integration elements in a UMAT subroutine. Is there any function/variable that can used inside UMAT?
We know that there is NOEL parameter inside the UMAT that corresponds to element number. So can we link this parameter to volume? OR Is there any parameter for element volume in UMAT subroutine?
Thanks for you reply,
EVOL, is not defined inside the UMAT :( It is in "output" part of ABAQUS.Following
- How do I categorize raw data into categories "Low," "Average," and "High"?
I have data for number of phone calls made from a list of different people where:
So if somebody makes 11 calls, I would like them to fall under the category "average"
If somebody makes 0, low and 76, high. My questions is how to divide up the rest of the data so it falls into one of these categories? I am working with a sample size of 1000.
I have dealt with mixed metric data sets many times. In the simplest case involving dichotomous [characteristic present (1)or absent (0)] and continuous variables, one can proceed pairwise through the data set using the point biserial correlation coefficient. See: https://en.wikipedia.org/wiki/Point-biserial_correlation_coefficient. This is unwieldy to the extent that you want to predict the strength of relationships between the continuous dependent variable, work load, and a set of categorical variables. There are many approaches, depending on whether you are testing an explicit prediction model or looking for possible predictors. If the latter, the use of classification and regression trees can provide an efficient and elegant solution. See: Systat 10: Statistics I, Chapter 3. I have archived an article on ResearchGate that uses this method. See: https://www.researchgate.net/publication/274959835_The_economics_of_equality_an_exploration_of_country_differences_in_S.S._Herr_L.O._Gostin_and_H.H._Koh_The_Human_Rights_of_Persons_with_Intellectual_Disabilities_pp._387-414?ev=prf_pub.
I will be happy to provide whatever guidance you need if you choose to try this approach.Following
- What is "Flex Learning" and how does it compare to an "Independent Study" course?
The topic of creating a new model called Flex Learning to offer courses came up today in my office. This model is supposed to be completely student-driven in terms of delivery of content - the student can decide to do their course f2f, online or blended. In all of the descriptions I have seen, I have not seen any mentions of group work or collaborative learning methods to enhance learning opportunities. Thus this led me to believe its probably based on an "Independent Study" model. Can anyone confirm or deny this?
From what I can gather, Flex Learning is an umbrella term for all the hybrid learning options out there, i.e. blended (online/classroom), online only with or w/o discussion boards, self-paced, independent study, the flipped classroom, MOOCS, etc. The institution sets the parameters for their version(s) of flex learning options. There are probably as many variations as people who create and use them.
- What references do you recommend me to learn "ANFIS" for forecasting of Organizational systems in filed of Management??
An adaptive neuro-fuzzy inference system or adaptive network-based fuzzy inference system (ANFIS) is a kind of artificial neural network that is based on Takagi–Sugeno fuzzy inference system. The technique was developed in the early 1990s.Since it integrates both neural networks and fuzzy logic principles, it has potential to capture the benefits of both in a single framework. Its inference system corresponds to a set of fuzzy IF–THEN rules that have learning capability to approximate nonlinear functions. Hence, ANFIS is considered to be a universal estimator.
You can see my paper:
Adaptive Fuzzy System Modeling published in 2001.
or Ch2 and Ch3 form:
Li-Xin Wang, Adaptive Fuzzy Systems and Control, Design and Stability Analysis, Prentice-Hall, Inc 1994Following
- Any suggestions for a single-copy gene in nematodes for qPCR?
I am running a qPCR to quantify the ratio of genomic to mitochondrial DNA in my samples. I was planning on using 18s as my genomic marker, however this can be present in 50-350 repeats in the genome based on the literature, so is not comparable to the gene marker I have selected from the mtgenome (which is only a single copy per genome). I'm thinking of using vinculin, which is shown to be a single copy in C. elegans... any other suggestions? Thank you!
Thanks- I'm not actually doing any multiplexing- it's just a very simple SYBR deltadelta ct experiment. I have the reaction working very well with 18s but my comparison between the two is essentially meaningless because I have no idea what the copy number of 18s is in my species (I'm working in marine mammal parasitic nematodes, and there is almost no available sequence data).Following
- What is the best application of plant growth promoting rhizobacteria ?
what is the best method to evaluate the plant growth promoting potential for my strain on arabidopsis thaliana ; inoculation of seed or soil? and in vitro or vivo?
you can also directly inoculate soil with bacterial culture (with broth media).
This will provide some nutrient (carbon source) to bacteria for primary stabilization in soil and probably helpful for bacteria to adapt soil environment under in-vivo conditions. I have used this method by my self and the result were quite effective.Following
- What dielectric materials are transparent in visible region and high reflective in NIR?
I want to design a low pass filter.Following
- How is the switching table implemented in direct torque control of induction motor using three level inverter?
please tell me three level inverter fed induction motor drive complete switching table showing with the condition of flux and torque.
You can find a good paper in this issue in research gate (Torque Ripple Minimization for Induction Motor Driven By A Photovoltaic Inverter)
oor from JPE journal : 2-JPE 09-46Following
- Is it possible to produce white, electrically conductive, doped zinc oxide powders, without sintering/calcining?
I am trying to synthesize white, electrically conductive powders by doping zinc oxide with other metal oxides. I am trying to maintain as white a color as possible so many dopants are not an option. Most literature I have read calls for treating the powder at high temperatures but I don't have access to a high temperature furnace in order to anneal/sinter the powders.
I would appreciate any suggestions or links to literature that may help guide me to an answer. Thank you.Following
- Critically discuss the following statement. Gene expression data and systems biology is allowing us to understand the control of complex traits?
Im havin bit of trouble tackling this question? any help on what I should write about or the points i shud mention would be much appreciated. I keep seeing articles about eQTL and QTL are these relevant as well?
Thank you in advanceFollowing
- Which solvent is better to dissolve polysulfone ?
polysulfone polymer is used for preparing asymmetric membrane by inversion phase method , we need to use a solvent like DMF, NMP,... I would like to discuss with you
which solvent is optimum in point of view chemical, economic and environmental ?
Dear Nizar Matar,
Many thanks for your kind response, that study show well the effect of solvent on the morphology and permeation through PSF membrane.
I'm very grateful for your nice contributionFollowing
- How do I make a boundary layer in icem cfd?
How to make a boundary layer in icem cfd. I am doing meshing; i noticed, i don't really need a structured meshing in the far field. So wny do i not ignore it. Need to find the right tab to do the boundary layer in icem cfd.Following
- Studies of the relation of water depth and (ecological) water quality in standing water bodies?
Standing water bodies like ditches, canals and (small) lakes that are shallow (< 1 meter) can have a bad ecological water quality with high nutrient concentrations and algal blooms. I am looking for studies that describe the relationship between water depth and water quality and possibly also the underlying processes. Any suggestions?
Often times, the reasoning for poor water quality in shallow ditches, canals, and small lakes, relate to the input of everything from excessive nitrogen and/or carbon input, perhaps from fertilizers, herbicides, insecticides, and fungicides, to dumping of lawn waste and the like, into ditches and canals. Do you see a significant change in pH from day to night? What is the specific conductivity like, i.e., high relative to "clean" bodies of water in the areas? Bad and good water are somewhat relative depending on what is the norm for the area. A lake that is shallow but gets good oxygenation due to wind energy will look comparatively different to a stagnant type of lake. As mentioned above, emergent and submerged macrophytes along with types of algae and diatoms will tell you much, as will the macroinvertebrate fauna. As the old adage goes, dilution is the solution to pollution, i.e., the more water, generally the better chance for "good" water quality. You might have a look at the US EPA protocols for the various methods of sampling different types of water bodies, as well as the protocols used by the USGS National Water Quality Assessment Program (NAWQA), where there is a wealth of information (http://water.usgs.gov/nawqa/), inlcuding many papers of interest to you. This link takes you to the protocols for all the methods of data collection in the field and interpretation (to a degree). By the way, a lot of lake work, much of it shallow, is being done on the North (Arctic) Slope of Alaska (though they are typically what we might determine to be in good ecological condition, but much blows over from the West, and will thus affect the water quality, often in a bad way), and many papers have been written, and can be found by searching http://pubs.er.usgs.gov/ . Good luck and Cheers...BobFollowing
- How to predict temperature intervals for REMD simulation to use with GROMACS ?
I am using GROMACS for doing various simulations, now I started working on REMD (Replica exchange molecular Dynamics) for understanding folding pattern of few of my proteins. If anyone could briefly explain me how to choose a temperature intervals for simulations, it would be so helpful. Also I couldn't exactly get how to use this equation Ti = T0*e k*i to derive temperature intervals. Total atoms in my protein is 757. Please let me know your comments.
- How can I reduce the background from secondary Ab in IF ?
I am trying to look at RAD51 and BRCA1 foci in 293T cells by IF. I have problems with non-specific signal in the "secondary Ab only" control. The following is the protocol that I use:
1. 293 T cells grown on a cover slip coated with Lysine.
2. Wash cells with PBS and fix in 3% PFA in PBS.
3. Permeabilize with 0.1%Triton X-100 and 0.02% SDS in PBS.
4. Block with PF buffer (0.1% Triton X-100, 0.02% SDS and 2% BSA in PBS)/
5. 1:100 primary Ab in PF buffer - incubation at 37C for 1 hour.
6. Wash with PF buffer - 3 times - 5 minutes each.
7. Secondary Ab - 1:500, 1:1000, 1:2000 incubation - 1 hour - RT - dark.
8. Wash with PF buffer - 5 minutes - 3 times.
9. Dip the cover slips in water and mount them on slides using mounting media and sealing with transparent nail varnish.
10. Let it dry and image.
Any idea as to how to reduce the background from the secondary Ab. I am thinking of the following:
1. Titrate the secondary Ab.
2. Increase the BSA to 3 or 5% ?
3. Reduce the Secondary incubation time to 30 minutes - RT.
As the above gave you very good advice,I make only two comments. We found in some instances the washing times can be extended beyond what is often the norm. And two remember images are a question of signal to noise. You can also adjust your optics and and also improve your image.Following
- Is there an online database for actigraphy data of sleep recordings (including hypnograms) ?
i am searching for an online database that provides multi-sensory data of sleep recordings (polysomnography data). It is important that the sensor data includes data of an accelerometer (in the best case wrist worn) as well as an EEG based hypnogram to compare the acceleration to.
Thanks in advance,
Well, in fact there are such databases e.g.
unfortunately most of the provided datasets on that site either lack of the accelerometer data or EEG data respectively. Thats why i asked if there are similar databases. But thanks anyhow.Following
- Does anyone know the maximum number of samples which we can give to sensory panellists to evaluate at a time, in a descriptive test?
I have to evaluate yoghurt samples for six characters (i.e. Color, Appearance, Odour, Taste, Texture and Overall acceptability) using a 5 point hedonic scale. Can I use 5 samples at a time?
I would say that we have to find the best compromise between the number of samples tested by the panel and the number of sessions needed to perform an experiment. We have several publications with 10 samples tested in the same session with good results.Following
- How to build a small cluster?
I want to create a small cluster for my group. We want to run jobs in parallel employing Accelrys Material Studio. We have a server with Material studio in it. It has two CPUs and we want to add more CPUs and perform the system for working in parallel maybe with HP-MPI.
What will I need?(Hardware and software)
- Can anyone provide me the link of IRC calcn dealing with catalytic reaction in Gaussian 09?
Can anyone provide me the link of IRC calculation dealing with catalytic reaction in Gaussian 09?
I'm a newbie in this field and I've done some IRC without catalyst but with catalyst I find problem. Actually I've much confusions so to clear all that I need a tutorial and this ain't available on Gaussian website as far as I've searched.
I also have problem with the catalyst cluster making. Can some one please send me the link of this too?
Thanks in advance
I've problem with the complex of cluster with substrate.
And one more problem is with support like Pt on Al2O3.
- A thought experiment inspired by Chalmers' “Fading Qualia”. What manipulations to the neural circuitry demolishes consciousness?
Instead of gradually replacing biological neurons with silicon neurons as in Chalmers' Fading Qualia, I attempt to gradually replace dividable functions of biological neurons with silicon emulation.
The question is, at which manipulation stage does our brain lose consciousness (qualia)?
1) Replacement of axonal spike propagation with an external artificial mechanism that uses radio transmission (e.g. WiFi): Causality between presynaptic neuronal firings and postsynaptic PSPs is preserved, but now neurons are physically isolated.
2) Further replacement of postsynaptic PSP integration with an external artificial mechanism: Causality between presynaptic neuronal firings and postsynaptic somatic membrane potential is preserved, but now without sophisticated dendritic-somatic computation.
3) Further replacement of transformation from postsynaptic somatic membrane potential to postsynaptic firing (Hodgkin-Huxley Eq. mechanisms) with an external artificial mechanism that integrates presynaptic firings and activates postsynaptic neurons by current injection accordingly: Causality between presynaptic neuronal firings and postsynaptic neuronal firings is preserved, but now without an intact internal variable, the membrane potential.
4) Mere replay of spatio-temporal neuronal firing patterns by external current injection: Zero causal interactions among neurons.
We seem to have crossed posts maybe. The problem with the pipeline is that his one is like ten billion balls of string all unwound and tangled together. Not easy to know which pipe you are blocking where!
The other point is that qualia do not pass down the pipeline. Only codes. I am not quite clear what you are wanting qualia to be. They are facets of experience - of some sort of input to something that expreiences. They are not something moved from here to there - we would use a biophysical description to cover that, not a phenomenological one.Following
- How can I calculate Mean Absolute Error (MAE) in pose estimation?
Can anybody help me how I will calculate mean absoulte error(MAE) in pose estimation. I know it is error between ground truth pose and predicted pose but how i will caluclate this. Thanks
Thanks Giovanni Lasio.....I solved the problem....the question is old one....But thanks for your replyFollowing
- How can I prepare a grid connected solar PV simulation model?
I want to prepare a simulation model of grid connected solar PV which may be implemented at my university help by providing some reference link.
The grid-connected PV system is composed of PV model, VSI model, coupling inductance, and grid. You can find these models in our publications on research gate.
- 1. What are some large high-dimensional data collections (sets)? And how can we apply Nearest Neighbor Search?(what are nearest neighbour queries ?
Implementation of nearest neighbor search in high-dimensional data sets. How it is more efficient and more economical.
How can we increase the efficiency of nearest neighbor search.
2.What is Nearest Neighbor search and Waht are the high performance environments that are to be set when applying nearest neighbor search in high-dimensional data sets ?
The question seems as part of your home work. If so Try to do some research on yourself that will benifit you in the long run.
NB is efficient in terms of simplicity and computational complexity.
I am attaching two documents. Go through these to have an understanding of Naive Bayes algorithm. Consequently, you can determince yourself the benifits of using NB algorithm.Following
- How is internal active site pKa determined if a protein unfolds during titration?
Harris and Turner has a very nice review article (attached) that discusses pKa enhancement or perturbation due to various factors stabilizing a buried ionizable residue. Overall the main takeaway is that the pKa of ionizable residues are highly conformation dependent.
One major question that I have regarding active site pKa determination is the issue of unfolding during experiment. My thinking is, as a protein or peptide is titrated, the structure will change dramatically over pH and disrupt the original environment that residue exists in. In that case, wouldn't the measured pKa be the standard "solvent accessible"/"intrinsic" value?
Also, I am looking for any cases in which researchers have tried to determine the pKa of model peptides such as polyalanines, polyglycines, etc.Following
- How can I solve an over constraint error for a 2 part indenter problem with ABAQUS (Finite Element Analysis)?
I am trying to model an AFM tip pressing down on the center of a circular membrane. The AFM indenter is an analytical sphere and the membrane is clamped around the perimeter. These parts have surface-to-surface contact. I am applying a displacement to the AFM tip.
My problem is that I am getting the following warnings that ultimately result in an error:
***WARNING: THE SYSTEM MATRIX HAS 31081 NEGATIVE EIGENVALUES.
***WARNING: SOLVER PROBLEM. NUMERICAL SINGULARITY WHEN PROCESSING NODE
MEMBRANE-1.3306 D.O.F. 1 RATIO = 310.855E+09 .
The nodes it gives error messages for are actually usually half way in between the edges and the center of the circle.
- What are the problems that arise with too much RNA or cDNA in a qPCR reaction?
I'm trying to increase sensitivity (detection) for a gene expression assay. The more RNA or cDNA I add the more detection I get. I need to be able to detect at really low parasitemia, so the thought is that if I keep adding more material, then I might eventually be able to get some detection. My master mix gives me room for about 10ul of material+water to add per reaction. Would there be a problem if I decide to add all 10ul of my material? How would I be able to detect if there is a problem?Following
- How do you manage attendance of students?
I would like to ask how do you provide attendance to your students. I mean what strategies you use in order to require students to attend classes. If I am not wrong, most of the students are generally not interested in attending classes due to many reasons (like most are just interested in getting grades, or they attend due to friends etc).
In such cases, how do you make sure that students would attend classes regularly and take interest in classes, despite the fact that classes are interesting and engaging. Are there some "student variables" which are difficult to manage at all costs?
I'm not superman. I find it very difficult to find out what the needs are of 30 or more students in a class and I teach 3 or 4 classes per term. It says that I am supposed to customize what I do to match their needs. Their needs are expressed to me by what, I am sure, you see all around you all the time: Everyone's nose is buried in his/her Ipod and doing texting, movies, etc. They learn the names of every new entertainer who warbles into a microphone or shakes his/her body in a movie. They've seen every new video that makes a splash on u-tube. But even when I make them purchase a subscription to The Wall Street Journal (and they turn in receipts proving they have gotten it) and a screaming headline announces a major industrial situation, only a few students come to class the next day knowing of the story. There is close to zero curiosity. They go to Wikipedia for everything and use terminology on their PowerPoint slides they were too uninterested to even look up--so they stand and stare when you ask for the meaning of a word on their slide. Yes, they are carrying knowledge and learning according to their potential. They will, I believe, eventually wise up, but by then, they will have damaged themselves rather badly. But right now, beating them over the head with tests, contorting yourself and taking valuable time to tailor your lectures, is going to be of limited success with a lot of them and of zero success with those who don't come to class. But we cannot flunk them out, because then we'd have no classes. Then we, as professors, will get the blame for not being able to teach properly. The latter will, of course, come from administrators sitting high up in their executive ranks and who will make pronouncements on what we do. And blame us for the disinterested students.Following