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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- Is there a pedagogy that is purely inclusive?
A totality of inclusive methodologies strategies, approaches values and attitudes towards teaching and learning facilitation.
exactly, Sipho we need to encourage inclusive, enabling and trans-formative pedagogies in classroomsFollowing
- I am looking for an english native speaker to correct my Manuscript about secondary sexual traits in Bluethroats
The Manuscript deals on sexual ornaments and non-breeding events in a Eurasian ornamented bird. It was fisrtly unaccepted in Bird Study, Animal Behaviour, Behavioural Ecology and Sociobiology, Acta Ethologica.
I hope you've been successful with your paper. I just want to give a quick advise for others who read this while looking for a qualified proofreader: A colleague of mine has recently convinced me to give my paper to http://textlove.de as they work with over 900 academic proofreaders and a lot of native speakers. I'm very impressed by the quality and really recommend this company!Following
- What are the reason for peak disappearance in uv spectrum?
My compounds are Mos2 and Ws2.
The primary reasons for peak disappearance in uv Spectrum could be:
1- Cleavage of the conjugated π-bond systems;
2-The lost of the chromofore from the molecule;
3- Fragmentation of the molécules;
4-Very low concentrations;
5- overlapping of the bands.Following
- Cytochrome c release - WB identification.
Does anybody have some experience in western blot analysis of cytochrome c release? Especially in the context of human cancer cells? Maybe you can recommend some good antibodies? Thanks a lot!
Yes I am looking for cytochrome c release in human breast cancer cells. I would recommend you to go for Santa Cruz antibodies for the same. They are quite good. Happy research :)Following
- I'd like to ask if the steepest decent method can success if the initial assumption for the solution is poor?
In other words which method is not sensitive method for the initial assumption for the input ? secondly can I use it to minimize function such as F=(x,p,u1,u2) with two inputs to minimize u1,u2 at the same time (by using steepest decent method)Following
- Does anyone have a solution to to problems when using Scopus files in VosViwer?
VosViwer is a very poferfull tool in bibliometric analysis but When I select the text corpus option, and then Scopus files I get either a run-time error message or a very sparse density graph, with just few terms analyzed.
I've never had this kind of problem. Even working with 200,000 documents and selecting titles and abstract.
What version of VOS are you using?
How many RAM has your computer?
Can you send me the Scopus files, or unless part of it, to test it?Following
- Mandelbrotian vs Gaussian ?
In engineering/economic practices I encounter many applications that gaussian distribution is used to model the probability of events. I know that distributions like gaussian distribution have a definite variance and mean that gives us good information on the probability of events.
On the other hand mandelbrotian or fat-tailed distributions describe processes that outlier events are not as unlikely as processes that are modeled using gaussian/poisson/exponential distribution.
I see many processes that could be considered mandelbrotian but treated as gaussian (for example in economic predictions/forecast or some machine learning problems).
I wonder who gives us permission to use distributions like gaussian/poisson/exponential distribution with so much confidence in many applications?Following
- What are the suitable EEG electrodes, Active dry electrodes or reusable Ag/AgCl for a BCI related project, also consider their availability in India?
I am confused between choosing suitable eeg electrode for my project.The active dry electrodes like g.SAHARA are costly and not easily available.How about making some DIY active electrodes?Is it appropriate to design active electrodes for a system that itself needs to be tested?Following
- Anyone has come over a weird melt curve and gel image from real time RT-PCR?
I have been trying many times and still failed to give single peak in melt curve. I have designed a new primers to detect all 6 variant of my target gene. Please refer to the blast result as attached. I have done Ta optimisation but the result is weird. My desired PCR products should be 137bp but the gel image didn't match. Final concentration for both forward and reverse primers are 0.5uM. The one step real time RT-PCR is as below:
Cycle 1: (1X)
Step 1: 42.0 °C for 30:00.
Cycle 2: (1X)
Step 1: 95.0 °C for 05:00.
Cycle 3: (40X)
Step 1: 95.0 °C for 00:10.
Step 2: 60.0 °C-65.0 °C for 00:30.
Data collection and real-time analysis enabled.
A: 65.0 B: 64.8 C: 64.2 D: 63.3 E: 62.0 F: 61.1 G: 60.5 H: 60.0
Cycle 4: (1X)
Step 1: 95.0 °C for 01:00.
Cycle 5: (1X)
Step 1: 55.0 °C for 01:00.
Cycle 6: (61X)
Step 1: 65.0 °C-95.0 °C for 00:10.
Increase set point temperature after cycle 2 by 0.5 °C
Melt curve data collection and analysis enabled.
I did not have positive control.
Below are the primer sequences:
Forward primers: 5'-tca ttt tga cgg aaa tgg caa cc-3'
Reverse primers: 5'-aag gaa cat agc ttc aac cgc ag-3'Following
- Can anyone help me in designing a safe method for UV light exposure(from lamp) to cell cultures?
I need a safe procedure as it involves radiation. I am working on PDT, which involves UV light exposure to cell cultures. I need to know a safe, simple procedure to do the same. The source of light will be a portable lamp producing UV rays. What measures to be taken to confine it to a small place and what safety aspects should I undertake, when performing the experiment.
- What electric field one meens talking about field dependence charge mobility in organic materials?
When we talk about charge carrier mobility dependence on electric field (for ex. Poole-Frenkel behavior) what electric field is it: total field applied by external voltage or local field which takes into account the local charge densities? How can we benchmark this dependence with experiments?Following
- Is anyone aware of implementation of modelling of two interval forced choice behavioral data?
Is anyone aware of implimentation of modelling of two interval forced choice behavioral data (like drift diffusion models for two alternative force choice experiments)? There are mutual inhibition models for modelling neuronal data (Machens, Romo, & Brody, 2005) and also one indirect implimentation using psychometric function for oculomotor response that I have found (Liston & Stone, 2008). My experiment is a two interval forced choice experiment with button responses. Help appreciated!!
Hi James Broadway,
Thanks for your reply. Signal detection theory is indeed the most preferred method of analyzing behavioral data from two interval forced choice experiments and we are also using it. However, we would like to model the data so that we can make more inferences about how the data was generated (by changing input parameters).
Drift diffusion models (atleast that I have found) apply to two alternative single interval forced choice experiments which model the decision variable from the start of the trial for the two alternatives. The problem with two intervals is that the two alternatives are not presented simultaneously but sequentially (often with an interval in between). Thus, there are suggestions that models like drift diffusion and race models don't apply well to the two interval tasks (attached conversation).
Although there are suggestions from neural models of two interval forced choice experiments that the decision variable is kept in memory for the first alternative till the other alternative is presented (Machens, Romo, & Brody, 2005), this is mostly applied in neural models (along with influences of working memory). I have not found any behavioral analysis of such data.
One of the other ways (that will also be useful for us) would be to use a function that can transform from stimulus properties to a psychometric function (like in Liston & Stone, 2008). However, they use an explicit function for oculomotor responses. I do not know if there is a function that can transform from stimulus properties to generate a psychometric function in our button press responses (that I can compare with actual psychometric function from data).
- can anyone get the frequency dispersion of wave propagation in an infinite cylinder with the symmetry?
I want to study the propagation of a wave in a cylinder. Due to the symmetry of cross section, 1/4 of cross-section needs to be researched for the reduction of computational times. So I want to write a code to get the dispersion relation with the characteristics of displacements, thus the node displacements are transformed to 1/4 nodes displacements. Therefore, I need to find the transform matrix, how can I get it ? Can anyone help me?
Tanks for your suggestions! Good luck!Following
- Homicide regression: What variables can be interacted?
I have a homicide model with the following variables: my dependent variable is the log of intentional homicide rate while the explanatory variables are: Gini Index (log), GDP per capita (log), Trade, Unemployment, Rule of Law index, Corruption Index, Urban population and Government Expenditures across 6 regions - Latin America, North America, Europe, South & East Asia, Middle East and Sub-Saharan Africa.
Please I need ideas on which of these variables can be interacted that will make intuitive sense. I have some results already, I only want to enrich my results. Thanks in anticipation.
Homicide rate is the dependent variable and there are 9 explanatory vars: Gini index, GDP per capita, male youth 15-24yrs, pry enrol rate, sec enrol rate, rule of law (rol), corruption, male unempl and death penalty. Out of these, only death penalty is 'binary'. 1 for countries upholding the dtpen and 0 otherwise. I have a global dataset - 137 countries, 7 regions. Analysis from data show that LAC region has higher homicide rate and higher income inequality while Europe is low in both variables relative to Sub-Saharan Africa (base region). I'm just wondering how the relationships among these vars can be further investigated beyond the a priori that the 'Gini index is a strong determinant of homicide rate'. Will it make any intuitive sense to explore the role of institutional quality by interacting rol and unemployment rate; rol and education vars?....any thoughts, please? Thank you.Following
- Can I do qPCR with no biological replicates? How reliable data from a single sample in a tumoral cell line can be?
So far I always perform biologial replicates (n=3 for cell lines, n=6 for mice, and n=20 for human), but now due to the huge number of conditions I've been aske to do only one sample per treatment. Would that be acceptable?
I can appreciate the need to streamline things especially when bottlenecks arise from mass amounts of experiments/ conditions...etc. But I must agree with both comments above, that the lack of biological replicates is a circumstance that must be avoided.
Obviously in some cases the availability of replicates is lacking therefore only one experiment can be conducted, but as you know for scientific validity there must always be replicates. Considering the use of qPCR, replicates form a crucial part to overall work flow employed by this technique simply because there is so much variation. This could be from inter-patient/ animal variation, RNA extraction method/s, RT efficiency, sampling error, handling error...and so on. A tough set of variables to guess against when you only one biological sample to test.
I don't know the full set of circumstances you are under by being asked to only conduct one sample per treatment. I can also appreciate that it might put you in somewhat of a pickle. But I would strongly suggest that you stick to your guns and maintain a stance of scientific correctness, no matter what the repercussions may be. Moreover, I would strongly suggest you have a formal meeting with whoever asked you to conduct this work in this way and discuss a new strategy if all else is not possible at this time. This is important for the validity of your work (which will ultimately enrich your work/ research field) and also the validity of yourself as a scientist. I hope this has helped, and I also hope things aren't blown out of proportion for yourself.
- Does somebody have information on the nitrogen (NO3- and NH4+) levels in marine healthy environments (e.g. open bays)?
In the South-eastern Pacific, usually concentrations of NO3- are much higher than NH4+ levels in open bays. However, we have detected some seasons with similar and even lower concentrations of NO3-. Which should be the chemical/environmental cause if sampling and quantification protocols have not changed so far? Any help/comment will be very welcomed.
Limnology and Oceanography - LIMNOL OCEANOGR 01/1969; 14(6):912-920. DOI: 10.4319/lo.1969.14.6.0912
The question is ambiguous, but for sure this can help. See the topic of photoinhibition of NO2 oxidation to NO3 in the photic layer, find the article (Kiefer et al....). Nitrification, denitrification, water masses.....plenty topics to think about.Following
- What conditions are necessary for you to work comfortably?
This question is not intended to be used to design a work environment.
Answers can consider any type of conditions that help your work. As examples among others, you might focus on sound levels, or you might focus on particular types of illumination, or any other conditions you personally deem good for you to work.
Please freely discuss with each other.
Thank you very much for your feedback.
I think there is no special or fixed conditions that can be generalized in order to work comfortably. The most important thing to keep in mind that physically and psychological, everybody have different capabilities and limitations. Since homeostatic conditions in the body were not disturbed, then we can work or do activities comfortably. For example our senses have threshold limit value in which should not allowed to be exceeded.Following
- Is it possible to monitor air quality by remote sensing satellite imagery?
We normally monitor air quality by measuring pollutant gases such as CO,COT,SO2,NH3 and H2S by special instruments. But this is very costly. Remote sensing will be more economical and effective if we could measure these gases using satellite imagery.
Yes, It is possible to monitor air quality using satellite remote sensing, for more details you can find recent publications of Dr. Bilal at
- If any coordinates will do in General Relativity, is spatial curvature necessary? Is GR more complex than necessary, and is curvature verified?
GR was introduced along with the principle that not only is no coordinate system preferred, but that any arbitrary coordinate system would do. The complex mathematical machinery of covariance was introduced (including tensors) to express the laws of physics, any of the laws not just GR, in arbitrary coordinates. This allows coordinate systems in which the distances vary with position and orientation, and in which the speed of light is non-isotropic (varies by direction), and such coordinates are routinely used in famous solutions such as Schwarzschild.
So, it is not just the curvature of Riemannian geometry that requires complexity, but most of it is required by independence from coordinates. And if indeed physics is independent of coordinates, can coordinates be found for solving GR problems in which space (if not spacetime) is flat and therefore graspable to the ordinary intuition?
For an introduction to analysis of orbits using only time dilation, not spatial curvature, see paper linked below. GR was derived from the equivalence principle on the assumption that curvature was the only way to explain equivalence, but this is an argument not a proof according to GR verification authority Cliff Will. If another method is available, it becomes a weak argument. Is there empirical proof of curvature?
As I said, you do not have to assume that a photon exchanges energy with the gravitational field in order to use a gravitational potential. That are two different questions. So it is o.k. to use the potential and energy conservation arguments.Following
- Can you explain generalized concepts on selection criteria for restriction enzyme that should be used to detect copy number of transgene integration?
I'm new to this field and want to learn generalized concepts on selection criteria for restriction enzyme that should be used to detect copy number of transgene integration? please help me on this and I thank in advance for your support.
Transgenes can be inserted as tandem copies (multiple copies in a row) in the genome. For digital PCR quantification, it is crucial that the different copies are detached from each other; each reaction should receive just one copy, otherwise, you underestimate the transgene copy number. There is a presentation on the Biogazelle website about digital PCR based transgene quantification.Following
- SDS gel loading dye becoming red while running, what is the reason behind it?
I am following all standard protocol of SDS page, but sometimes when I run my cell protein samples , they tend to show this red coloring , and I wonder how Bromophenol blue is becoming red, any reason behind it?
I hope you already got your answer from previous posts. I would also suggest you to check the pH of your loading dye as well as extraction buffer (Buffer you have used to extract/finally dissolve your protein). You can try adjusting the pH of your loading dye with 1M Tris-ClFollowing
- It is stony dye or something else?
Anyone seen this stuff? It is stony dye or something else?
We have found it in a tomb of the Neolithic age in China.
Thank you for your sharing, your suggestions are very useful, I will take these samples for more analysis, is there any published papers on ''pumice''?Following
- Can anyone help with protein extraction from cell lines for nuclear magnetic resonance spectroscopy? I would like to get a protocol in order to extract proteins from cell lines to be subjected to nuclear magnetic resonance spectroscopy. Of course both homemade methods or kits would be fine.
You may ask to Roberto Anedda who is a Chemist with a strong expertise in NMR.
Roberto is currently working at Porto Conte Ricerche (PCR) you can find his email very easily on the PCR web site.Following
- Does anyone have experience with a Leica DM IL microscope- How does one use fluorescence?
We have a Leica DM IL inverted microscope. Can anyone help me out on how to switch to the fluorescence settings? When viewing my stained slides.. Instead of a black background, I am viewing a grey one. Please help.
First: the microscope should be on and inside the dark room
Second: change the view type to GFP (if your are using the green fluorescence) you can do this from the top middle part of the microscope
Third: open the filter on the right side of the microscope
Last: Take picture and save to your space
This is the manual for Leica DM inverted microscopes
- Can anyone help with dopamine in vivo measurement by FSCV?
The background waveform changed when the CFE is inserted into striatum, and the sensitivity of CFE get low.(as shown in the following picture). After stimulation of MFB, only the stimulate artifact can be recorded, no dopamine redox current can be seen. I don't know why the CFE works well in vitro but badly in vivo.
My setup include: Axon 700B with CV7B headstage, CED micro 1401 mkII
Probably your electrode doesn't´t work well or the MFB stimulation is not in the right place.Following
- Etching of the ITO?
How to etch the ITO coated on glass for electrode in organic solar cell?
You can use a polyamide tape as pattern.Following
- Sebastian Maaß added an answer in Silver Nanoparticle:Does anyone know of software for Analysis of TEM images of Silver Nanoparticles?
Does anyone know of a good program for determining the size distribution of nanoparticles from TEM images?
Dear Asher, could you upload one example image. It will be much easier to discuss the right program with one image in mind. We developed some IA algorithms. You might want to look on the publication as wellFollowing
- Is Water Desalination powered by CSP a good idea or what are the major barriers for commercialization?
It makes sense at first, you put a CSP plant in a coastal area (i.e. MENA region) and produce electricity through a steam turbine to power an RO desalination plant and use the waste heat for multi stage/multi flash desalination. But
-salt and aerosols of coastal winds harm solar field through corrosion
-DNI in coastal areas is lower and coastal weather impacts solar fields performance
-putting the CSP plant inland and connecting it to a desalination plant in a coastal location increases the cost of water and electricity due to the transmission of electricity to the coast.
I'm thankful for personal assessments of the issue and any tips regarding studies in this field.
I agree with Dmitri that direct solar distillation makes more sense. I am not aware of any report of a pilot or feasibility plant using CSP, which could guide toward erecting a large scale commercial plant. Have you thought of perhaps evacuated heat pipe solar collector attached to a "geyser"? The combination is proven/capable of reaching boiling conditions. I guess you can size it to your own delight.Following