Q&A

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.

Browse Topics

A B C D E F G H I J K L M N O P Q R S T U V W X Y Z
  • How to manage higher total soluble salt water for irrigation?

    Water management or Agronomist, Soil scientist

    Muayed Fadhil Abbas · University of Basrah

    it  is possible to manage  total soluble  salt water  content for irrigation by using either  drainage water which contains high salinity levels or prepare different levels of NaCl in mM concentrations. In both cases, it is necessary  to use tanks for the storage of such high salinity irrigation water.To get  the best result, drip irrigation system is the best. The level of salinity used,of course, depends on plant species. The  levels of salinity in the tanks must be checked regularly.

  • Ha Pham asked a question in Collaborative Writing:
    Does anyone know any work on assessment of collaborative writing?

    If it's possible, can you tell me what the methodology and method are? Thanks.

  • Moumita Ghosh added an answer in Marine Benthos:
    Is anyone familiar with an alternative staining procedure other than Rose Bengal in case of benthos sample?

    Your suggestions would be highly appreciable.

    Thanks in advance.

    Moumita Ghosh · Presidency University

    Dear Craig M Robertson,

    For meiobenthos Methyl Blue can be used?

  • Can a native plant species be referred to as Invasive?

    In some cases, a species native in a given region can exhibit rapid growth and biomass accumulation, high reproductive output, phenotypic plasticity, plasticity of reproductive strategies and many other characteristics of invasive alien species.

    An example is Digitaria abyssinica, a plant native in tropics, but a very noxious weed as it forms dense mats of grass that suffocate co-occurring species. Also a a problem for agriculturalists in Africa. When i checked some invasive plant databases, i found it was not listed as invasive.
    Does that mean we only classify plants that are alien to a given geographical range as invasive?

    ANINDITA CHATTERJEE · Indian Statistical Institute

    Hi Nelson,

    According to the standard definition, an invasive species is a plant/animal which is not native to that specific location. Invasive species are mostly alien species and have been introduced into that eco-region from other places and have a very high growth and reproductive ability. Thereby, such species have a high tendency to spread, often at the expense of native species; and may cause multi-fold damage to the environmental and socio-ecological system.

    Often, even native species exhibit many 'characteristics' of invasive species, such as rapid growth and reproduction; and may often out-compete other native species, stunting their growth. In such a scenario, such native species are generally regarded as pest or weed species.

    Best,

    Anindita.

  • Faramarz E. Seraji asked a question in Harmonics:
    Anyone could suggest some valid references for Measurement of Second and Third Harmonics in Si-Photodiodes?

    Some references containing second and third harmonics in Silicon-Photodiodes, obtained experimentally.

  • Lee Siggens asked a question in Prostate:
    Does anyone have a protocol to stimulate AR dependent gene expression with DHT in PNT2 cells?

    We want to stimulate PNT2 or other prostate cells with DHT to stimulate AR dependent gene expression. What is the best way to do that and where can one buy cell culture grade DHT?

  • Please suggest the solution that can dissolve aggregated Bovine serum albumin (BSA).

    Please suggest the solution that can dissolve aggregated Bovine serum albumin (BSA).

    Thanking you

    With best regards

  • Senthilkumar Rathnasamy asked a question in ATP:
    Is it possible to functionalise PEG in ATP system?

    What are the laboratory protocol available to functionalise the polymer in two phase extraction. In order to enhance the partition coefficient of the taken system i want to extract more amount of protein to desired phase with more affinity. kindly suggest

  • Prashanth Suravajhala added an answer in Cytoscape:
    How to annotate the nucleotide sequences in terms of KEGG Orthology (KO)?

    I have a RNA-Seq data in which I have to construct the KEGG Pathway for DGE between two samples. I also have nucleotide sequences (contigs) in the fasta format (.fa) file. Kindly tell me how to assign the KO IDs to these nucleotide sequences. Also help me in construction of pathways either using KEGG, Cytoscape or any other pathway network builder software/server.

    Prashanth Suravajhala · University of Copenhagen

    Dear Punith

    The best way is to use Galant plugin in Cytoscape which solves the purpose that you aim for.   Please make sure that the ids are obtained from nuc sequences using NCBI's batch entrez before you construct the pathway networks. 

    Hope this helps

    Prash 

  • Apart from the "traditional" three dimensions of sustainable development (environment, economy, society), what other classifications can be used?

    Are 3 or 4 pillars enough or should they be discarded completely? The CSD have abandoned the three dimensions and opted for using cross-cutting themes instead.  Is there any other evidence to suggest this is a better way to go?

    Sven Herzog · Technische Universität Dresden

    In my opinion, we have to differetiate between an analytic approach in scientific work. In the latter context, we should keep focusing on the classic three dimensions. CSD is not a  scientific but a political institution. In this context it may sometimes be meaningful to leave the clearly structured path. However, I cannot  identify any benefit arising from the cross-cutting approach.

  • Dr. Kamran added an answer in Butterflies:
    What is the basic morphological character for the identification of cabbage butterfly?

    i need identification key of cabbage butterfly.

    Dr. Kamran · Aligarh Muslim University

     Well Answered by Dr Enrique.

    Dr Enriques is the best authority to follow specially for butterflies.

  • Renzo Bianchi added an answer in Drones:
    Should a lesgislation be enacted by US congress to ban the use of drones for combat and reconniassance mission?

    Drones are very dangerous instruments aimed to kill its intended target on the spot. However on many occasions this has not been the case, instead reports have been given of more deaths and casualties of  innocent civilians that have become victims of  drone strikes then terrorists being killed. According to an analysis carried out by the human rights group, the US drone strike that was intended to target a number of 41 men killed 1,147 people, who were innocent victims in Pakistan.

  • Claudio Messori added an answer in Consciousness:
    Can consciousness be defined?
    Dan Dennett tries to shake our confidence that we ever can know what consciousness is. Would you agree with him?
    Claudio Messori · Azienda Unità Sanitaria Locale Parma

    I suggest the following conversation with Francisco Varela  Consciousness in the Neurosciences, (translated by Tristram Bruce), held in Paris, on January 29, 2001, at the LENA Laboratory in the Hospital of the Pitié-Salpétriêre: 

    http://www.psychomedia.it/jep/number14/varela.htm



  • Chandan Ghosh asked a question in Free Will:
    What type of toxic substances are usually present in ferruginous waters ?

    considerable free carbon dioxide and some toxic agent are present in it, hence it is not advisable to remove iron  alone leaving the free carbon di oxide which may be cause corrosions of mains and pipes and  the identification of those toxic agent are much more essential.

  • Daniel Schwarzkopf added an answer in Missing Data:
    Is there an R package for multivariate distribution for missing data using maximum likelihood estimation?

    I'm currently anaysing the missing data problem using maximum likelihood estimation.

    I would like to test the estimation on missing data for multivariate dataset using R. I found several packages in R for MLE but some of them are only discussing and applying the general function/term/concept to apply MLE but  do not specifically applying on the missing data problem for multivariate dataset.

    My current dataset is having the combination of categorical,continuous and discrete data types

    I would appreciate if someone could recommend me the notes or tutorial for applying missing data using MLE in R

    Thank you in advance 

    Daniel Schwarzkopf · Universitätsklinikum Jena

    Treatment of missing data in Structural equation models (SEM) or linear regression models can be done by Full Information Maximum Likelihood (FIML) estimation. Given missing completly at random or missing at random this leads to unbiased estimations. The package "lavaan" is, to my knowledge, the most complex SEM package for R. It offers the option to fit models by FIML.

    But be aware that FIML is only applicable for models with continious outcomes. If you have categorical outcomes or mediators in your model it will not work.

    For these conditions multiple imputation methods are the best solution. There will surely exist R packages on these too.

    If your study question may be handeled by propensity score analysis, there also other methods that can be used.

  • What New Media do you use in teaching at the University?

    It is said, that New Media transform and revolutionize modern teaching as they improve transmission and distribution of information and knowledge. If it is truth, we should use them.

    I am wondering... to what extend and in which form does New Media are used at the University ???

    Laura Teruel Rodríguez · University of Malaga

    Hi! I used Web 2.0 or Social Web in class. We use Twitter to share news that go with the topics discussed in class. We also use wikis and forums to  to engage students in the collective work . I consider very important to involve each student in the overall group learning and these tools are very helpfull. I have published a paper about that topic and currently I am researching on that question in my university (comparing the use of social media in the different Faculties). If you are interested in that question, we could talk.

  • Diego Baderna asked a question in Sonication:
    Toxicity testing of soluble components from soils.... Metals can promote cell proliferation?

    Hi to all,

     I have performed an HepG2 cell proliferation assay on 14 soil samples from two sites in the north of Italy. I have exposed cells to water soluble extracts of soil (soil suspension in water (soil water ratio 1:4 w/v ), sonicated for 1 hour, deposited for 24 h and sonicated for 1 h... centrifuged and liophilized).

    After 24h and 72 hours of exposure I have recorded a proliferative effects in most o f the samples. Cells are more than 120% respetc to their control (untreated). In some sample the stimulation effect is present at low dose, in other samples the effects are present in all the tested doses.

    Someone have articles or works that I can cite about this proliferative effects?

    Are metals able to promote proliferation?

    What compound can be responsible of these effects?

    I have hypothesized that there are some phytoormones which can promote proliferation... I think that these compounds are not estradiol-like compounds because HepG2 do not express ER receptors.

    Please help me!

  • Can anyone working with qualitative methodology recommend authors on multi-sited research?

    I am doing research comparing three cities and I think that a multi-sited approach is more suitable for the project. However, I do not have literature talking on this from a political science perspective.

    Thanks for your help

    Some essential readings:

    Falzon, M.-A. 2009. ‘Multi-sited Ethnography: Theory, Praxis and Locality in Contemporary Research’, in M.-A. Falzon (ed.) Multi-sited Ethnography: Theory, Praxis and Locality in Contemporary Research. Aldershot: Ashgate, pp. 1-23.

    Hage, G. 2005. ‘A not so multi-sited ethnography of a not so imagined community’, Anthropological Theory 5(4): 463-475.

    Hannerz, U. 2003. ‘Being there... and there... and there!: Reflections on Multi-Site Ethnography’, Ethnography 4(2): 201-216.

    Marcus, G.E. 1995. ‘Ethnography in/of the World System: The Emergence of Multi-Sited Ethnography’, Annual Review of Anthropology 24: 95-117.

    Marcus, G.E. 2005. ‘Multi-sited Ethnography: Five or Six Things I Know About It Now. Problems and Possibilities in Multi-sited Ethnography Workshop, 27-28 June 2005’. Sussex: University of Sussex. Retrieved 6 May 2015 from http://eprints.ncrm.ac.uk/64/

    Nadai, E. and C. Maeder. 2005. ‘Fuzzy Fields. Multi-Sited Ethnography in Sociological Research’, Forum: Qualitative Social Research 6(3).

    Robben, A.C.G.M. 2007. ‘Introduction to Part VII: Multi-Sited Fieldwork’, in A. C. G. M. Robben and J. A. Sluka (eds), Ethnographic Fieldwork. An Anthropological Reader. Oxford: Blackwell Publishing, pp. 331-336.

    Weisskoppel, C. 2005. ‘Moving across: Looking at multi-sited-ethnography in theory and practice’, Zeitschrift Fur Ethnologie 130(1): 45-68.

  • Abu-Bakre Mohamad asked a question in Abaqus:
    Can anyone help me to monolithic loading in Abaqus ?

    I have concrete wall with foundation beam modeled in Abaqus. I used pressure load to simulate the effect of gravity load and I have horizontal loading so I applied displacement load at reference point (coupling to surface) is it right procedure.

    After analysis how to know the maximum value of horizontal loading and how to draw the load displacement curve?

    Thanks

  • Philip Jehu asked a question in Financial Reporting:
    Please, what model can I use for financial analysts'processing of financial reporting information?

    Analysts processing of financial reporting information to make stock recommendations. They use earnings forecasts etc.

  • Joyyan Lam asked a question in Phosphatases:
    How to assay Factor M-P?

    A question asks that:

    a phosphatase is discovered and it will remove a phosphate from Factor M-P:

    Factor M-P + phosphatase-->Factor M

    How do I assay this phosphatase?

    Should I use the substrate concentration at the plateau of the curve? As the product formation rate is nearly constant at that point.

  • Roy Goldman added an answer in Electromigration:
    How thick should Ti adhesion layer be?

    Making 100 nm wide nanowires to break controllably using electromigration, see DR Strachan et al. for example.

    Previously I've used 2 nm Ti adhesion layer and 14 nm Au; I use ebeam evaporation to deposit the metals in vacuum, into a PMMA negative from EBL. I am concerned however that a 2 nm film of Ti is not continuous, and that 4 nm would be safer.

    I am wary of going too thick however, as when the gap breaks via electromigration, I try to trap a molecule in the gap, connecting two Au electrodes. the Ti can be problematic for two reasons:

    1. If the exposed Ti, which is presumably not oxidized because it was protected by the Au, does not also electromigrate then it will short the ends. Some recent work suggests that Ti can electromigrate however so it is possible that it would do so.
    2. If the Ti does electromigrate, a Ti-Ti tunnel junction would not likely contain the molecule (I use thiolated molecules to form self-assembled monolayers on the Au).

    Previous work, my favorite of which is from Takhee Lee et al. has used 1-2 nm of Ti or Cr, so I am further hesitant to go thicker. It is difficult to test this matter as well.

    Thanks in advance for any advice.

    Roy Goldman · Marvell Technology Group

    Hi Darin,

    I had similar problem when I fabricated OTFT with a short channel. Only in my case the gap between the Gold electrodes is much wider (~50nm) and I don’t produce it via electromigration.

    Eventually I used Cr as adhesion layer, and after producing the gap I used a short step of Cr etch to remove the Cr from the gap. It couldn’t work with Ti since our Ti etcher contain HF so it attacks the SiO2

  • What assessment strategies are faculties employing in their blended courses?

    Blended learning requires in most instances a mix of F2F and online sessions in courses. How are assessment strategies changing as a result of having to use technology to teach?

    Jeannette Paulin-Campbell · Boston Media House Sandton South Africa

    I'm following this chain with interest, and Antonio, i would be particularly interested to hear more about your innovative initiative, thank you

  • Mohammad Jane Alam added an answer in Autodock:
    Which is the best software for large polymer-protein docking calculations?

    Hello everyone,

    I have a problem regarding the performance of a docking calculation between a large polymer and a protein. The polymer is really huge.

    I have tried vina and autodock, but the polymer has more than 32 rotable bonds. Additionally I have tried other softwares like Rosetta or HEX, but with not succes, because are prepared for small molecules.

    Any advice or possible solution?

    Thanks in advance,

    Best regards,

    Mohammad Jane Alam · Aligarh Muslim University

    Have you tried SwissDock - The online docking web server  ?

  • Sergey V Cheresiz added an answer in Transduction:
    After how much time can we infect the cells with Lentivirus?

    Hi everyone. I prepared the Jurkat cells for transduction i.e by adding polybrene, IL-2 and RPMI with 10% FBS, I want to know that after this, if somehow i could not add the virus immediately, and i add it after 2 hrs, does it affect the transduction process?

    Sergey V Cheresiz · Novosibirsk State University

    You may also try protamine sulphate instead of polybrene. Slightly less efficient, but much less toxic and you can use higher concentrations and times of infection. And, I agree with Mikhail, spinoculation works better, both with suspension and adherent cells.

  • Xuran Zuo added an answer in Erosion:
    How can we have rectangular-shape aeolian erosion?

    I observed rectangular-shape aeolian erosion in the coastal area of South China, as shown in the attached picture, very regular pattern and spectacular. We know this kind of caves/holes are usually caused by wind or water force during the erosion. But how can we have such a neat distribution of rectangular holes? Does it mean that during the erosion, the wind was always blowing from one direction that is perpendicular to the outcrop?

    Xuran Zuo · The University of Hong Kong

    Natalia,

    I don't know if the permafrost can be involved. The field location is at the southern most part of China, with a latitude of about 22 N, where the temperature seldom decreases to 0 degree. According to the plate reconstructions, the South China Block has been always moving around the equator since Devonian. But I'm not sure about the global temperature in the past...

    What kind of evidence can we observe in the field if the permafrost is involved?

    Thanks!

  • How to enrich Transcriptome data analysis ?

    I am working on algal transcriptome I performed a de novo assembly of the database retrieved reads made annotation with Blastx , GO, Pfam, PRIAM and Interproscan I have got the data only for about 5% of the total contigs I obtained the KO ids from KAAS I require ideas to enrich my data and to proceed further for pathway reconstruction with the transcriptome data Kindly suggest tools and ideas for the above problem

    Lakshmi Krishnakumaar · Anna University, Chennai

    thank you Mr Patel for the answer

  • V. Baranwal added an answer in Solid State:
    Does anyone know of a table listing the solid state properties of common semiconductor materials?

    Ideally it should list crystal structure, workfunction, melting points etc of CdSe, CdS, InP etc.

    V. Baranwal · University of Allahabad

    http://www.semiconductors.co.uk/propiivi5410.htm#CdS,CdSe,CdTe

    http://www.semiconductors.co.uk/propiiiv5653.htm#InP,InAs,InSb

    The above links may be useful for you..