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.
- What is the best questionnaire for self assessment of percieved stress?
Looking to add a questionnaire on perceived stress to a study in which music therapy is given to subjects who self identify as having high stress levels. I've seen the Perceived Stress Questionnaire which seems to have been highly validated and reliable. Just looking for other opinions/options.Following
- How does fiscal policy stabilize output?
Fiscal policy has a stabilizing effect on an economy if the budget balance—the difference between expenditure and revenue—increases when output rises and decreases when it falls. For instance, if output suddenly contracts, policymakers can let tax revenues fall along with income (or even deliberately cut tax rates) and let unemployment benefits increase with the number of unemployed. This maintains income and purchasing power for individuals, and supports demand. Policymakers can also raise demand directly by deliberately spending more. Either way, higher deficit (or a lower surplus) effectively cushions the blow on output.
Thank you very much Dr.Subhash C. Kundu for your helpful answers.Following
- Does anyone know about an electrochemical method to eliminate Zinc into water ? Any paper to see reactions or reactors for aplly method in industry.?
I'm starting a project to create an electrochemical reactor to recover zinc into aqueous wastes from galvanized industry. I'm interested to know if anyone has worked before in theme. So I'm looking for any paper or suggest.
I woulk like to thanks to everyone interested in solve my question.Following
- Why am I always getting false positive clones?
Hi, I just started work as a Technician here and have been trying to get 1 positive clone, but still no luck.
I have a 1.5kb insert in a 6.4kb vector. The latest I've used is 1:3 to 1:6 molar ratios of insert/vector, but still false positive clones. Insert and vectors are digested with Hind3/SstI restriction sites separately. I did not vector dephosphorylate since there is no complementation in the sticky ends.
The DH5a competent cells are home made, I've used LB instead of SOC for transformation. Each Amp plate has many colonies from spreading 100ul of cell mixture, but after doing boiling minilysate every single clone had an empty vector. Also tried PCR of the gene from the isolated plasmids from the cells, with no luck. How could this be??
1. Maybe the insert is toxic to the E. coli cell since it is a gene from another bacteria strain. How to overcome this?
2. The pores of competent cells are not big enough to take in the recombinant vector (~8kb). Maybe switch to XL-Blue cells and remake competent cells?
Any help would be much appreciated. ThanksFollowing
- Can someone help on hair analysis for heavy and trace metals ?
Hello dear Scientist
i am working on hair analysis for heavy and trace metals on Particle induce x ray emission i want to convert hair into powder from how i can? please send me related articles or easy way to convert hair into powder your cooperation will be appreciated in my Thesis thank you ...
[removed by admin]
Hair can be powdered by using Pulverization technique which is performed at a rotation frequency of 5000 rpm in 3 cycle interval. Process take place in extremely low temperature. Kindly see :
Kim et al , 2010.,Forensic Science International, volume 196, 43-50.Following
- Does anybody Know about a course where you can learn how to use CASA sperm class analyser software?
I am looking forward to learn how to use CASA for signalizing sperm parameters but everybody says it is very arduous to lean, and very tough to calibrate... I was wondering if there was any course focusing in CASA?Following
- Simulating risk on a property portfolio?
I have created a forecasting model, which comes up with future values for a rental index.
Further, I have transformed this volatile values into percentage risk, whereas 100% is the highest point in this values and 0% the lowest.
For example let`s take the time series:
2010 100 -> risk: 0%
2011 150 -> risk: 100%
2012 125 -> risk: 50%
2013 130 -> risk: ~68%
2014 140 -> risk: 75%
I would like to use the risk values on a real estate portfolio, to simulate the outcome and visualize cyclicality for a portfolio manager. Has something like that being done?
Currently, I couln`t find any research doing what I would like to do? However, I was wondering if there exists some related field or research to this idea.
I kindly ask you for good papers / theses of using "risk on property portfolios"?
Thx in advance for your replies!Following
- How might I confirm S. aureus isolates were vancomycin resistant?
The Disc diffusion Vancomycin resistant isolates should be retested using vancomycin Etests and the MICs should be reported. Which one is golden standard method for conforming VRSA?
E_test only can confirm résistance go vancomycin or other ATB
Be carreful with type of discsFollowing
- What elements should be used in mesh module for shell analysis subjected to bending in ABAQUS?
While I am doing a simple shell analysis subjected to bending using linear elements in ABAQUS, the analysis completed without any errors. But while I use quadratic elements, the analysis aborted. I have heard that for bending analysis of shell elements, quadratic elements should be used. But then why the analysis aborted? Meanwhile, I have used static general steps for my analysis.Following
- Would you like to get new results from old ERP data?
I wonder if there is any ERP scholar interested in reanalyzing old ERP data
using longer pre-stimulus interval (at the least from -1000 ms if the ISI allows) to verify the presence of two components in your sensory-motor tasks.
In stimulus-locked ERP, well before stimuli onset, it should be presents:
1) The old BP/RP (Bereitschaftspotential or readiness potential)
2) The new prefrontal negativity (pN)
It would be interesting to see how this top-down control is modulated by different cognitive tasks or in different groups.
For an example of this analysis, take a look to the attached paper.
This question is actual a proposal to all ERP researchers,
Could you reanalyze new or old ERP data using longer pre-stimulus interval (at the least from -1000 ms if the ISI allows) to verify the presence of two components in your sensory-motor tasks (the pN and the pP).
If you try, please let me know.Following
- DISTLM on presence/absence data?
got a data set of three variables set as presence/absence (ie 8 possibilities) among 1200 stations and I would like to run a DISTLM model on Permanova (Primer) but I am not sure if we can run a such model on presence/absence data. Thanks for your help!
I put down my apology....My answer is misplaced to this question.It should be for other one I have traced it.Following
- Is there a Taylor expansion at any order of the eigenfunctions of a given symmetric positive matrix?
There are classical results at order 1 but I am looking for an infinite expansion, in the case where eigenvalues are isolated. Are there also some results in the degenerate case ?
Thank you V.G. Kurbatov. I have just realized I already had this book !
Thank you Erkki for the Padé representation, I am gonna explore it.
Dmitry, what do you mean by partial differential equation 4+2+2 or 2+2+2 in space or time ?Following
- Where can I access trend data on solar LCOE for Europe?
I am looking for data on solar levelized cost of energy. I have US data. I am looking for Europe from 2009-2014. Is there anything available on the public domain? Most of the IEA/IRENA reports seem to be reporting for just one year or two. I am looking for trend data.
This study from ISE-Fraunhofer is very relevant:
- How effective is extrinsic motivation in the case of adult learners?
I certainly believe extrinsic motivation should only be applied in extreme cases, and that we should be intrinsic motivated to learn and to perform our work better than yesterday. How do you feel about being rewarded to learn?
Society and environment play a big role in learning. If boss/teacher behavior is bad, intrinsic motivation is not possible. In bad work environment, ideas are not born, even in those people mind who are self motivated and want to to learn.Following
- How can I perform a calculation with "charge" keyword freezing some atoms of the system?
I' m doing an embedded cluster calculation in which I have to fix the positions of some atoms and to add point charges with Gaussian09 program. this is my input file :
#P PBE1PBE/gen opt=modred nosymm scf=xqc freq pseudo=read Charge
and after the cartesian atomic coordinates, I specified the atoms that I want to freeze.
the calculation ends with this error "Cannot AddRedundant with Cartesian or Z-matrix opts.".Following
- How do we control MLSS concentration the in sludge activated system?
How do we control MLSS concentration the in sludge activated system?
please, how to keep [MLSS] constant during MBR's operation?Following
- What is the best method for measruing NADPH oxidase activity of membane fractions from skeletal muscle?
I need some advice on how best to measure NADPH oxidase activity in tissue from skeletal muscle.
Since there is no specific assay for NOX activity I plan to do subcellular fractination and then measure superoxide production just in the membrane fraction in order to exclude other cellular sources of superoxide.
What would be the adequate superoxide assay for this sort of experimental set up? As far as I have read, there are many possibilties but none of them is ideal.
I would really appriciate some help...
NOX activity is tightly regulated. Biochemical assays in in vitro may not be the best approach.
It is best studied or reconstituted at live cell level.
Pharmacological inhibition and knockdown (against subunits) approaches may be used.Following
- How can I interpret path coefficients greater than 1 in magnitude after we have removed multicollinearity in the data?
I conducted path analysis of some variables. However, some direct and indirect effects were more than one. Using variance inflation factor (VIF) and Condition Index values, some of the variables were removed from the model. However, even after removing multicolinearity, I get path coefficients more than 1 in magnitude. Any thoughts?
I don't know what method you are using to calculated the correlations but it sounds like you have a scaling problem (one or more of your variables are on wildly different scales) or the co-linearity problem is so bad that you are close to dividing by zero in the calculations. You could also have a coding error, extreme outliers or just bad data elements somewhere in your data set.
Good luck, BrianFollowing
- Why is there low yield adenovirus production with HEK293A cells?
I got some problem with producing CRE adenovirus. I bought this virus from company. When I tried to amplify it with 293A cells (MOI=10), I observed the Cytopathic effect (CPE). But this came very quickly, usually within 24h and all cells detached within 36h. The yield is very very low.
I read some protocols saying the CPE usually appears 4 days after infection. So is this means my 293A cells are not good (I use a very low passage, P4~P7)? Or is there any tricks to improve the adenovirus production? Thank you.Following
- Is there any reliable, relatively comprehensive sequence analysis, alignment, and cloning software available for either major platform? I'm looking for sequence analysis/alignment/cloning software that is free or relatively inexpensive (ie Vector NTI is off the table). BioEdit takes care of some of the functions I need, but I'm looking for something that integrates a variety of cloning functions into a single program - restriction digestion, ligation, BLAST, DNA->protein translation, quality checks for things like Kozak sequences, in-frame start/stop codons. This would save me an IMMENSE amount of time, so if anyone has any recommendations they would be greatly appreciated.
Did you try Genome Compiler? It's free, supports Mac and Windows, online and offline. You can use it in order to clone and map your vectors, for sequence analysis and alignment, primer design, etc.Following
- What is the correlation between XRD peak and ion irradiation doses?
Is it possible that XRD peak intensity decresing with increasing ion irradiation ?
Mushtaq Ahmad ji..... Please explain in details, How?Following
- What are the new methods for improving cashew nut production?
It could be observed that cashew nut production has drastically come down.
Something went wrong in composing the above.
It should read:
the internet has very good sources.
See form example
"Regional Office for Asia and the Pacific Integrated Production Practices of Cashew in Asia", an FAO publication from the late nineties but still very relevant.
"Cashew for higher income and improved living conditions in Mozambique’s rural areas"
available in pdf form.
But there is much more. Important is that management of cashew gets improved, the processing is modernized, and nuts and apple material are both used in the processing. Pests must be dealt with, especially insect pests
- Is it possible to use the EcoRI for complete digestion (based on digestion map) of E. coli total DNA in vitro?
The origin of EcoRI endonuclease is from Escherichia coli. in order to prevent destruction of its own DNA by the restriction enzymes, the bacterium marks its own DNA by adding methyl groups to it.
Franco is correct, for example with E. coli K-12, it should not be a problem with EcoRI.
It always depends on the strain you are using.Following
- Where can I get to know about India and China's pollution impact on earth ?
Air pollution to be specific.
In this paper you can catch some ideas:
- What is the most effective way to design an inclusive and effective SDG indicator framework?
The SDG agenda is broader and goes further than that of the MDGs, which poses challenges in terms of designing an effective and inclusive indicator framework. In our recent Lancet comment Measuring the SDGs: a two-track solution (Davis et al., 2015), we argue that a solution that could break a potential deadlock is a two-track approach, which would involve separate lists of indicators at the political and technical levels.
What would be other options for an efficient SDG indicator framework?
I want to share this snippet; a publication of the Fund for sustainable development - United Nations
“What is the background of the sustainable development objectives?
The background of the objectives of sustainable development (SDG-F, for its acronym in English) is a mechanism for development cooperation created in 2014 by UNDP on behalf of the system of the United Nations, with an initial contribution from the Government of Spain, in order to promote sustainable development through joint programmes of integrated and multidimensional character. The bottom part of the experience, knowledge, lessons learned and best practices accumulated during the term of the Fund to the achievement of the objectives of the Millennium Development (2007-2013).
At the same time, it aims to expand its activities promoting sustainable development paying greater attention to alliances between the public and private sectors. Gender mainstreaming and the empowerment of women constitute cross-cutting priorities in all our areas of work. The ODS Fund seeks to act as a bridge in the transition mechanism from the MDGs to the ODS, offering concrete examples of "how" to achieve a sustainable and inclusive world beyond 2015”.Following
- Does anyone know of studies on the relationship between use of new media and engagement in neighborhood (or district) life?
Social and cultural projects organized grassroots, to find solutions to common problems and develop social practices of development and planning.
Dear Vania you can look for these resources:
- Does anyone know of a green algae that has cell structure like mougeotia but has branches?
I have algae in a sample from a freshwater lake. There are several single filaments that I thought were mougeotia because of the shape of the cell wall and the twisted chloroplasts. I have recently found the same type on the slide but it has branches. That has me confused again. The branches sometimes have the same type of cells coming off and other branches are smaller node-like filaments instead of distinct cells. Each nodes of those portions each have a brown/red spot inside. Previously (in other slides/samples) I had seen several of these node-like filaments on their own and had not identified them. This is the first time that I found the node-like filaments attached to/ branching off of the filament that looks like mougeotia. I will try to add a picture to this later once my camera is charged but in the mean time if anyone can throw out some possible names for me to search down I'd appreciate it. I keep hitting a dead end.Following
- Is it time we shift emphasis from technological solutions to climate change & focus on the 'Human Dimension'?
Is it not obvious that nature can heal itself, if only left alone, and it is we humans who need regulation? Many natural parks managers do just that; seal off the area from human interference to let nature heal and recover. It is classified as 'Strict Nature Reserve"by IUCN. Complacency and inaction are not advocated here, as many have misunderstood, but the shifting of focus from technology to the human being. As technology is no match for human greed, isn't introspection & restraining ourselves more relevant than developing more technology, which caused the mess in the first place, by making it easy for a few to consume more? Since technology is only a short term quick fix which fails after a short time, isn't the real problem our addiction to material consumption & our lack of understanding about human nature? Isn't developing more technology sustaining the addiction instead of correcting it, leading to more complex problems later on, needing more complex technological quick fixes like higher drug dosages, more ground troops & equipment, (along with their debilitating side effects) in the future? Isn't this the vicious addiction circle we are trapped in? As researchers, do we merely buy more time with technology OR go to the very root of the problem, the human being?
A lot of hue and cry is made about climate change and the environment in general. Public and private money is poured into research to study its effects on the environment, sustainability etc. Should we study nature or ourselves?
" Our studies must begin with our selves and not with the heavens. "-Ouspensky
Human activities have been found to have a direct correlation to climate change and its impact on the environment(I=P x A x T, the Ehrlich and Holdren equation), in spite of what some complacent sections say to protect their own self interests.
We hardly know about Human nature. We can scarcely predict human behavior. We need to find out why we think like we do and why we do what we do and why, in spite of all knowledge and wisdom, consume more than what we need, in the form of addictions to consumption and imbalance not only ourselves but also the family, society and environment around us..
Humanity is directly responsible for all the unnatural imbalances occurring on the planet. Yet we refuse to take responsibility and instead focus on climate change, or fool the public exchequer with a 'breakthrough in renewable energy just around the corner'. We scarcely know what drives human beings. If we had known, all the imbalances around us would have had solutions by now, given the amount of money plowed into finding such solutions. Are we blindly groping in the dark of climate change because we don't know the answers to our own nature?
Is it not high time we focus on what makes us human, correct our consumptive behavior and leave nature to take care of climate change? Why focus effort on 'externals' when the problem is 'internal'- 'me'?
Aren't we addicts denying our addiction and blaming everything else but ourselves?
" We are what we Think.
All that we are arises with our thoughts.
With our thoughts, we make the world." - Buddha
IMHO, We don't need to save the World. It is enough if we save ourselves from ourselves. The need of the hour is not vain glorious interventions, but self-restraint and self-correction!
The Mind is the Final frontier.
I wonder what you will think about population after you see this:
Here are wmv and mp4 versions of Albert Bartlett's famous talk on the exponential function:
- Vitiligo, how does one be certain to classify a focal Vitiligo to a general Vitiligo vulgaris?
Focal Vitiligo and generalized vitiligo both can start as a simple focus, of hypopigmentation. How can one be sure to say that the lesion is focal. Can a simple epidermal graft cure focal Vitiligo, or should the same treatment be followed as in generalized Vitiligo?
It depends on age of presentation and evolution. A stable, dermatomeric, depigmented macule abrupted in a child and stable in its evolution in months/years can be described as a segmental focal vitiligo; on the other hand, a new lesion in an adult, with tendency to grow dimensionally during short time, requires a more strict follow up to exclude a possible evolution to non segmental form and correct systemic laboratory examination to exclude concurrent autoimmune disorder such as Hashimoto or Basedow tyroiditis. Epidermal graft and all possible surgical and physical intervention are restricted to very limited number of selected patients, that should be treated first line with topical treatment (corticosteroids, calcineurin inhibitors) and/or medical phototherapy (PUVA, UVBnb, UVA1, for example) and camouflage.Following
- How might bacteria in liquid medium be counted?
If bacteria is cultured in nutrient broths,how it may be quantified?
Plating the media after serial dilutions will give you the count of only viable cells unlike a spectrophotometer which will combine both viable and nonviable cells.Following