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  • John O Meredith added an answer in Risk Analysis:
    Web based Project Risk Analysis Software?

    I am developing a project risk assessment model for energy projects in my country. Which free (or cheaper) web based software can help me do this more so that i expect more than 15 experts to participate in virtually scoring the risks based on probability and impact of each risk factor. The software must accommodate expert scores which must be automatically collated.

    The output must enable me to see which risk factors are more riskier and then do some further quantitative risk analysis to develop weights for each risk factor which can be used on a case study?

  • Alexey Stepanov added an answer in Nanomaterials:
    Can anyone inform me how can I completely remove sodium hydroxide and other sodium residues from the carbon dots without adding any acid?

    After synthesis of carbon dots in sodium hydroxide solution, how can I remove complete sodium from the carbon dots? Please inform me.

    Thank you

    Alexey Stepanov

    You can simply remove NaOH and other sodium residues by multiple washing with water. I would use a few sonication/redispersion steps. Next, its always possible to remove water under reduced pressure for example.

  • Ruth Leon asked a question in Transfer Factor:
    Can transfer factor molecules be tested in a model organism at an undergraduate level?

    I am an undergraduate biology student at Whittier College. As a student fascinated with the workings of the immune system, I am hoping to do research on the immune response of transfer factors in a model organism. Because we are such a small institution, money is an issue and so is the proper equipment to do a large scale experiment. Therefore, I am hoping to test transfer factors on a model organism such as C. elegans or maybe bacteria. I have been looking up literature on transfer factors and have yet to find any experiments other than in humans or mice. Does anyone know if it is possible to test transfer factor in a model organism with viable results? I would like to conduct a longevity study for sure and am looking into other avenues of study available if possible. Any help would be greatly appreciated! 

  • Ioan Domuta added an answer in Wireless Communications:
    How do you understand the coexistence in Wireless Communication Systems?

    The coexistence of wireless devices (WDs) represent an important challenge. As far I understand the coexistence concept considers at least two considerations - spectrum (frequency) & coverage area- and I include other one: time. With these three 'parameters' I can describe, in wide sense, the coexistence but I do not know if my context is complete, then I would like to know your idea,

    -How do you define Coexistence of WDs?     

    -What parameter must I consider to define it?

    Your comments are important for me.


    Ioan Domuta

    coexistence: The ability of one system to perform a task in a given shared environment where other systems have an ability to perform their tasks and may or may not be using the same set of rules. (IEEE Std 802.15.2™-2003)

    By the standards are limited the transmission power (20 dBm/2.4 GHz), spectral density (10 dBm/100KHz for 802.15.4) and spurious emissions. To limit the spectral density and increase the immunity to noise is carried out spectrum spread by FHSS, DSSS, very short impulse UWB, ...

    The MAC plays a very important role to avoid collisions.

  • Louis Brassard added an answer in Gravitational Waves:
    What are the philosophical questions raised by gravitational waves?

    'On February 11, 2016, the Advanced LIGO team announced that they had directly detected gravitational waves from a pair of black holes merging' (Wikipedia)

    This is to invite views what sort of philosophical questions might be implied by this discovery?

    Louis Brassard

    Dear Ferenc,

    Thanks for your kind words. Yes these feelings are a testimony and echos in us of this cosmic message which is the primordial art or our creation.

    I found some relevant information that might explain Hawking's comments on the relation between gravitational waves and inflation.  A few years ago, they detected traces of gravitational waves in the CMB in the BICEP2 experiment (see information below) which under certain caution might confirms Gutt's inflationary model.  It is mentioned that other methods of probing gravitational waves generated earlier than the CMB would have to confirm this discovery.  I do not know if LIGO will reach the sensibility level able to detect these gravitational waves of the early universe but other gravitational observatories will surely allow us to gravitationally probe that early universe. 


    BICEP2 uses about 250 thumbnailsize polarization detectors to look for a difference in the CMB light from a small patch of sky coming through its telescope in two perpendicular orientations. The instrument collected data between January 2010 and December 2012 at the Amundsen–Scott South Pole Station, where the cold, dry air offers especially stable viewing conditions.

    The Background Imaging of Cosmic Extragalactic Polarization 2 (BICEP2) experiment at the South Pole found a pattern called primordial B-mode polarization in the light left over from just after the big bang, known as the cosmic microwave background (CMB). This pattern, basically a curling in the polarization, or orientation, of the light, can be created only by gravitational waves produced by inflation. “It looks like a swirly pattern on the sky,” says Chao-Lin Kuo, a physicist at Stanford University, who designed the BICEP2 detector. “We’ve found the smoking gun evidence for inflation and we’ve also produced the first image of gravitational waves across the sky.”
    Such a groundbreaking finding requires confirmation from other experiments to be truly believed, physicists say.

     The BICEP2 detectors found a surprisingly strong signal of B-mode polarization, giving them enough data to surpass the “5-sigma” statistical significance threshold for a true discovery. In fact, the researchers were so startled to see such a blaring signal in the data that they held off on publishing it for more than a year, looking for all possible alternative explanations for the pattern they found. Finally, when BICEP2’s successor at the same location, the Keck Array, came online and began showing the same result, the scientists felt confident. “That played a major role in convincing us this is something real,” Kuo says.

  • William F. Hansen added an answer in Water Resources:
    How can illegal mining be controlled to manage natural water resources?

    Protection of water resources.

    management of wetlands .

    improper land use.

    William F. Hansen

    I dealt with this years ago as a hydrologist in Oregon and N California.  Situations of trespass, mining without permit, miner  leaving a project half done and disappearing, some do good work, others just lie, do not perform or underperform.  Those willing to do good work, should not be penalized because of bad actors.  But if you end up with most bad actors, it may be hard to get them to change.  If you, landowner, agency or state issue permits, for many operations, get a performance bond to fix things if the miner does not.  But, the first thing, you need good laws on the books, and people willing to enforce if necessary.  someone in law enforcement or appropriate agency with authority to go with.  Miners may have guns, so be aware and don't put yourself at undue risk.  We would usually discuss the rules with the miner, discuss what is acceptable types of mining, and what is not, and give a warning, outlining what would be needed to fix, rehabilitate or restore conditions.  If things were too bad or no cooperation, we would issue a citation, take plenty of pictures always, water samples if needed, etc. If there,were hazardous materials, fish kills, lots of bank erosion and sediments in the stream, citation was common as damages were likely substantial.  If you need to go in front of a judge, you should prepare estimate of infractions and damages to resources and if available, damages to downstream water users, any fish kills, hectares disturbed, etc.  Learning to read individuals (I.e., the miners), confronting them in a way you get your point across but don't get shot, and be ready to back off by all means if things go wrong, live and come back another day if miner gets,threatening and you are not prepared.  We shut operations of unresponsive miners down, and also would help them develop responsible plans if they were willing to consider resources and to recycle their wash water on site and not discharge it into streams, and process gold off site, rather than in the national forest.  They are responsible in their permit to keep sediment and Chemicals out of the streams, and reshape and restore the area after completed.  Miners should not be given a permit until they can provide proof that there is a need to mine, valuable minerals so it is viable operation, and they recognize and conserve the resources to an acceptable degree.  The goal is not necessarily to stop all mining, but consider legal mining with good, well thought out plans, operations that avoid and mitigation of damages, regular inspections of work, with an adequate performance bond if they abandon the site.  

  • Charles Bertelsen added an answer in Unpublished Works:
    What wisdom or literature do you have now that you wish you had when you started graduate school in the sciences?

    Entering graduate school, for many of us, heralds a time of rapid change and maturing as professionals.  But a lot of that maturing comes about through painful lessons about how to be good scientists.  Sometimes much of this wisdom has already been written about and can be given to graduate students at the start of their degree to help them see the pitfalls many of us fall into as we develop into professionals.

    What literature (papers, unpublished work, blog posts, books even) do you consider to be fundamental to new graduate students in the sciences?  What wisdom or resources do you have now that you wish you had when you were starting? I'd like to focus on broad stuff- not necessarily fundamental papers specific to a field, though those also have value.

    Three pieces that were helpful to me were:

    Forscher 1963.  Chaos in the brickyard. Science.

    Stearns. Some modest advice for graduate students. http://stearnslab.yale.edu/some-modest-advice-graduate-students

    Huey.  Reply to Stearns: Some acynical advice for graduate students. http://faculty.washington.edu/hueyrb/pdfs/reply.pdf

    Charles Bertelsen

    I'm a little surprised you haven't received any answers to what I think is a very interesting question. I entered graduate school 50 years ago, and to put it mildly a lot has changed. I think it is very important to keep up with what is happening in your field and related fields, and the internet is an incredible boon. (We didn't even have computers back then.) And I don't mean Wikipedia. Sign up for newsletters such as phys.org (set up an account at https://sciencex.com/ and select topics) and use Google scholar a lot. One great feature of Google scholar is the alerts tab--enter a lots of key words, and you'll be amazed at how many great papers you'll hear about via e-mail. You can quickly weed through a lot of stuff in a very short time and end up with very useful papers.

  • Godfried Van Moorsel added an answer in Ecological Niche Modeling:
    What is the ecological role of barnacles/balanids in a marine trophic food web?

    What role do the barnacles play in a trophic food web? I would appreciate getting some references on fossil barnacles in this context.

    Godfried Van Moorsel

    In addition to the contribution of Robert S. Prezant I would like to add that substrate modification by barnacles is especially important in early phases of succession. In the North Sea, new and empty hard substrates may become completely covered by barnacles after an immersion of only a few weeks.

  • David Charles Wright-Carr added an answer in Creative Thinking:
    How to innovate new ideas?

    How to increase creativity, imagination, and innovate new ideas?

    David Charles Wright-Carr

    Put some distance between yourself and old habits, routines, and conditioning. Don't pay attention to those around you who say that whatever you are trying to do can't be done. Then do it.

  • Radouane Bahloul added an answer in Reflectance Spectroscopy:
    How do you find out the band gap using diffuse reflectance spectroscopy curve?


    I am confused about how to accurately find out the band gap of a semiconductor using diffuse reflectance curve. I have plotted the data but am bit doubtful about the tangent to be drawn. I am uploading curve and have followed two methods to find band gap using tangent. Please confirm the correct method.

    Is the method in image B correct or in B ? If not then how do I proceed.

    + 1 more attachment

    Radouane Bahloul

    I have the same quotion as that of Nouman Rafiq Does anyone have a response ? 

  • Ameen Salem Alwashmi added an answer in HEK Cells:
    Why Hek cells does not grow well after thawing ?

    Any idea about how many days i should give to my newly thawed Hek cells to grow ?

    I usually just change the medium after the day i thaw them and then i wait for them to reach 80% confluency but sometimes they just don't attach at all...

    Ameen Salem Alwashmi

    I used to have HEK cell. It needs more appropriate care especially when you want to freeze them down. If the cells contain few media before mixing with any preservative agents like DMSO, then the cells will not survive at least few of them will grow slowly, and vice versa. So, in order to make the HEK cells to survive for most of them after freezing and thawing, should not have any remaining media. That what I experienced with.

  • Ioan-Alexandru Rădac asked a question in Species Diversity:
    Any suggestions for a leaf litter sampling protocol in order to collect true bugs (C-Europe zone)?

    By the end of winter, I'm interested in comparing the species diversity and density of 3-4 sites. The areas are all riparian, so the ground is not all the time flat.

    For the moment I have planed the following design:

    • 3 samples per site (near water, 2 m and 4 m from water)
    • each sample in a plastic bag
    • hand searching in the lab (it's time consuming but seems to be more efficient in collecting the bugs from the samples) 

    I'm still thinking on sample size (in many papers is usually one square meter) and how to choose the sampling site in order to be objective.

    Suggestions / comments / or any other collecting protocol are gladly welcome. 

    Thank you!

  • Rajeev Dwivedi, Ph.D. added an answer in GIS Softwares:
    What are the differences between attribute and properties ?

    From philosophical point of view, Classification point of view and GIS point of view. For example in a GIS software everything is treated as an attribute. In philosophy it is more difficult task. Please clarify 

    Rajeev Dwivedi, Ph.D.

    TRUE! Exact answer by Dr. PANOS.

  • Delon Wilson asked a question in DNA Fragmentation:
    How to create a short list, satisfying specific criteria or filters from a public SNP database?

    I'm working on a project where we would use SNPs to detect donor vs recipient DNA fragments in plasma DNA samples. First we need to create a panel of SNPs filtered by the ethnicity of our patients and with MAF> about 43%. How is this done?

  • Paula Garcia asked a question in Statistical Testing:
    How many deviant stimuli are necessary to elicit a reliable MMN response?

    and what statistical test would be appropriate to test whether the MMN elicited by a small number of deviants is statistically significant?


  • Aishwarya Jacob added an answer in Matrigel:
    MCF10A acini recovery from matrigel for RNA isolation?


    I am trying to recover my acini for RNA isolation from matrigel. However, even after incubation in the Corning® Cell Recovery Solution (Product #354253), I find that there is "goop" or gel when I try to pellet my cells. The incubation was on ice for 1h. The centrifugation was at 200g for 5 min at 4 deg. I am unable, as a result, to recover the acini efficiently for lysis and RNA isolation. Any advice would be appreciated.

    Aishwarya Jacob

    These are acini that I have grown in 3D.

  • Girmay Kahsay Gebremeskel asked a question in Water Conservation:
    What kind of econometric model is appropriate for analysing risks of water conservation and harvesting technologies by smallholder farmers?

    I am  working a research on risks related to  farmers on water conservation and harvesting technologies. So, I want a clear method to analyse risk perception, risk sources and management practices of smallholder farmers on water conservation and harvesting practices. Getting relevant  literature is highly appreciated for my study.

  • Mahdi Rahimi added an answer in Encapsulation:
    Drug Encapsulation Efficiency in Nanoparticles can be more than 100% or not?

    I want to ask from experts that if we load drug in nanoparticles like SLN, Inorganic NP's etc, either drug loading or encapsulation efficiency in NP's may be more than 100% or not?

    Drug encapsulation efficiency is seen by indirect method i.e. by taking the absorbance of supernatant (obtained after centrifugation of Drug-NP's mixture) in UV Spectra.

    Mahdi Rahimi

    Dear Deepak Bhambere

    If polymer dissolve in solvent, it could alter the absorbent. So how we determine the concentration of drug?

  • Luisa Zupin asked a question in Cell Culture:
    HI! has anyone experience with DOK cell line?

    I'm working with DOK cell line but I have some problems. The cell don't proliferate quickly and I split them once a week. How can I improve the cell culture conditions?

  • Hamid Sharif Nia added an answer in Questionnaire:
    How do i interpret my Alpha cronbach value?

    Dear researchers,

    I have estimated internal consistency for a questionnaire with 50 items (five -likert point) by alpha cronbach. Alpha was .98.

    What is your interpretation?

    What can the cause be from your point of view?   

    Thanks for your help.

    Hamid Sharif Nia

    dear Dr Jorge Wilfredo Carrillo Flores and Dear Dr David L Morgan

    thank you so much for your help

  • James Leigh added an answer in ANOVA:
    Is there any assumption to be verified in a crossover model?

    Dear all,
    I need your help to clarify the following doubt about the crossover design and the underlying model, please.
    Is there any assumption to be verified for the validity of this model?
    For instance, I know that for an ANOVA model for repeated measurements, there are some tests about sphericity/compound symmetry.

    Is there anything like even for the crossover?

    Many thanks for any clarification!

    James Leigh

    crossover studies are only valid if the effects  of the exposure  occur  promptly and are short lived.

  • Dhirendra Kumar added an answer in Proteomics:
    I have a list of proteins and I want to get the information about how they are functionally involved in atherosclerosis, is there any database?
    Dhirendra Kumar

    If you are interested in knowing about the gene (not necessarily the protein) and its relationship with a disease, try DisGeNET. (http://www.disgenet.org/web/DisGeNET/menu;jsessionid=15gl6du1cmyrv77xqzmqt2b1a)

    It links articles which might have suggested association or functional aspects of a given gene with the disease. 

  • Urreynz Balasa added an answer in Soil Science:
    Does anyone has an Idea How to sterilize a soil ?

    for inoculation of biofertilizers.

    and for my research methodology.

    Thank you very much

    Urreynz Balasa

    Thank you very much sir , do you have an article or a research paper with you to support your answer ? please do send me . 

  • Luisa Zupin asked a question in Hydrocortisone:
    HI! what is hydrocortisone stability in culture medium?

    I supplemented the cell culture medium (DMEM) with hydrocortisone (5ug/ml) but I have informations about its stability at -20°, +4° and 37° C.

  • Dean Whitehead added an answer in Scientific Publishing:
    How can we speed up the time of publishing students work, without turn a frustration for their career? Is it getting worse?

    Some data suggest that wait times have increased within certain subsets of journals, such as popular open-access ones and some of the most sought-after titles. At Nature, the median review time has grown from 85 days to just above 150 days over the past decade, according to Himmelstein’s analysis, and at PLoS ONE it has risen from 37 to 125 days over roughly the same period. Many scientists find this odd, because they expect advances in digital publishing and the proliferation of journals to have sped things up. On the other hand it´s very rare the revisions to fundamentally change a paper message.

    Dean Whitehead

    Katrina - that's a sensible plan to build a 'balanced' portfolio. Maria - that is the inverse situation that puzzles many. There is far more competition in the the publishing world and far more journals than a decade ago - especially with the advent of open-access - yet reviews times are often longer. To compound this - journal copy 'in press/in advance lists are getting longer. I have an accepted publication that has been in press for 18-months now - and will still probably be another 6 months before volumed hard copy release. The plain fact is, however, that far more academics want (need) to publish due to revised institutional policies on 'performance' contracts. There was a time not so long ago - that PhD students (such as Katrina) were not 'expected' to publish. Now - most are actively encouraged and that can apply to other RHD students. If PhD students wish to take up an academic position they are often expected to have an emerging publication profile. It's also another way of boosting the publication profile of supervisors who are usually full-time academics. 

    At the end of the day though, there is little that we can do to speed up the process of publication for students. If they have a balanced portfolio and regular submissions over a year - then it might create the illusion that the process is quicker - as one isn't reliant on single feedback from a single source. I'm finding with a lot more journals now that manuscripts get a quick editorial board check first - before going out to review. That, to me, helps the process. It's better to get a quick reject than have to wait months for one. 

  • Mahmoud H Onsa asked a question in Pollution:
    Is it truly 'a zero pollution' when we use solar PV system?

    The answer obviously not. Can anyone give a quantitative figures of the pollutions of PV module fabrication pollution or environmental effects..

  • Aswin Gopakumar added an answer in Nanoparticles:
    In which solvent SnO2 nanoparticles will be dissolved?

    in which solvent SnO2 nanoparticles will be dissolved?

    Aswin Gopakumar


    I think there is a small misunderstanding with the nanoparticle concept here (Please apologize if I am mistaken). They are solids, which in principle can be dispersed as a colloid in a solvent, be it organic or inorganic. They will indeed react with strong acids or bases, but you end up losing the parent SnO2 nature. 

    You can refer this paper for some idea. 


    All the best.

  • G. Bothun added an answer in Galaxy:
    What are the typical values of gas fraction (gas to stellar mass) in a spiral galaxy as a function of Hubble type?

    It is well-known from many galaxy surveys that the value of gas fraction (gas to stellar mass/ surface density) increases as one moves along in the Hubble's tuning fork diagram, from Sa -Scd type. So, does any paper/book talks about the typical representative values of that fraction as a function of Hubble type?

    G. Bothun

    I think you want to access much more recent estimats of H1+ H2 - such as measurements down by ALMA.  Yes there is some general relation in that the lower the bulge component of the galaxy the more gas there is in the disk (to support continued star formation).   Galaxy interactions however can serve to drastically alter the gas content and location : see this example  http://adsabs.harvard.edu/abs/1997ApJ...481..741M

    so I am not sure the concept of "representative value" means all that much

  • Stefano Giammarco added an answer in Plasmids:
    What universal primer shoud i use for sequencing?

    hi i'm writing a kind of essay and i need to sequence a pEGFP C1 coding a CDKL5 gene. so basically i need the sequence of the CDKL5 and i would send the plasmid plus the primers to a company to get it done. The primers, i have to use , have to be universal ones but i don't know what type should i use ( m13 or T7 ) and the reason to choose one instead of another. i hope i explained well. thanks a lot.

    Stefano Giammarco

    thanks a lot for your answer. sorry to bother you but can i use both primer or it has to be only one ?