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  • Khairun Nadiaa asked a question in Honey:
    Antibacterial activity of honey on staphylococcus aureus and e.coli?

    the activity of the bacteria?

  • Estefa Violeta asked a question in HEK Cells:
    How can I assure the transfection of Hek cells with pCMX plasmid?

    I'm gonna transfect Hek293 cells with a pCMX-LXR construct, and I want to know how can I select the cells that have the construct? 

  • José Torregrosa added an answer in Corpus Linguistics:
    Does anyone have experience in Linguistic Corpus Analysis - German and other corpora?

    I am looking for colleagues who have experience in linguistic corpus analysis. What is your research about? Anyone doing analysis in German Corpora? Italian or French? Thanks a million for your input and experiences!

    José Torregrosa

    I try to investigate the best way of teaching German as a foreign language taking into account a communicative approach. In this way, I need analyse audiovisual corpus. It is not enough, to analyse the structure of language itself, I mean only the linguistic system. I need to analyse, what it is said, but also what kind of melodies or intonation is applied and how all of that is moved using gestures.

    I think, my students will need all of this to be communicative competent and to communicate effectively with the native of the target language.

    Therefore, I analyse recorded conversations on the street, because this is the type of German communication I think my students have to learn to be communicative competent. We also carry out intonation analysis to show what kind of melodies are used in the different communicative situations and what kind of meaning are involved. Finally, we also pay attention to the gestures that are developed during these communicative interchanges in order to analyse how they are co-estructured with the other semiotic systems (verbal language and intonation), but also to analyse what kind of meaning are being communicated.

  • Shahabaldin Rezania added an answer in Chemical Analysis:
    How do you calculate fixed carbon in biomass?
    How do you calculate fixed carbon in biomass?
    Shahabaldin Rezania

    Is there good references for this equation??

    FC= 100 - Moisture - VM - Ash

  • Kartik Parelkar added an answer in Eustachian Tube:
    Have you ever had a patient with eustachian tube foreign body?

    A 20 yr old male with active squamousal disease in his right ear was advised HRCT B/L temporal bones,which showed an incidental finding of a tiny metallic foreign body 3000 HU in middle of the eustachian tube and soft tissue inflammation all along the eustachian tube.

    What would be the ideal way to remove such a foreign body and should it be in the same sitting with the modified radical mastoid surgery that he was being planned for?

    Kartik Parelkar

    Could a wait and watch policy or leaving behind the foreign body and doing an aerotympanoplasty be a risky option? Could the foreign body migrate or cause erosion of the bony wall of the carotid? A scary thought ! 

  • Lu Sun asked a question in Puromycin:
    The optimum puromycin concentration for Raw 264.7

    Hi! I am trying to knockdown a gene in Raw 264.7 by shRNA. First I need to do a puromycin killing curve. I already increase the puromycin as 16 ug/ml, on the 4th day of antibiotic added, still has 10% Raw cells not be killed. Because most concentration range of puromycin for selection is 0.5-10 ug/ml. Does anyone has experience of using puromycin to select Raw cell transduced by a pLKO.1?


  • Miranda Jane Walker added an answer in Anxiety:
    Interrelationships between MOTIVATION & ANXIETY / FLA: can anyone recommend RECENT articles, please?

    I'm interested in any recent (post 2014) articles on the interrelations between motivation and anxiety. Thank you!!

    Miranda Jane Walker


  • Kartik Parelkar added an answer in Vestibular Diseases:
    What is positional PTA?

    Its an useful test in perilympatic fistula cases. But can someone explain how it works exactly . Thanks.

    Kartik Parelkar

    Thank you sir. So is it the air bubbles in the cochlea which cause the improvement in hearing after a patient of perilymph fistula lies down and gets up? Sir is there any particular method of doing this test? 

  • Hossein Javadi added an answer in General Relativity:
    A hot iron is heavier than a cold one, true or false?

    Why does the same object weigh more when it is hot than when it is cold?

    The reason why hot objects are heavier is because E=mc^2. If you have absolutely identical objects that have the same weight exactly when they are at same temperature, then when one object is heated, it will weigh more. This is because the gravitational force depends on the stress energy tensor in general relativity.  The stress energy tensor 00 component is the total energy of the body, which includes the rest mass plus the kinetic energy of the object. Temperature differences means that there is a different amount of kinetic energy in the motion of the atoms of the two bodies.


     How is it describable by massless photon (electromagnetic energy)?

    Hossein Javadi

    Dear Santosh
    You are right. The argument "the same object weigh more when it is hot than when it is cold." is true regarless of its size (affectetd of heat).

  • Renee Wever added an answer in Scientific Writing:
    How recent must one's sources have been published to be referenced in a peer-reviewed journal article?
    I understand that sources should be cited no matter their age. However, I am noticing a highly prominent journal article-trend in which works older than two decades are rarely referenced in text. Is there some sort of unspoken disrespect for writers who cite papers from say - the 1960's? There are many great works from these time periods that laid the foundation of much of today's published research. It seems that scientists are going out of their way to cite more recent articles, with similar information, rather than the original research due solely to the date on the citation.

    Why have these papers been left out of reference lists so frequently? Does a paper seem less "current" with the inclusion of aged journal articles?
    Renee Wever

    Apart from the reasons provided above, a rule of thumb is that you need to provide references for those claims that are not based on your own results, nor are commonly known. The latter is of course somewhat tricky, but one could state that something is commonly known if it is in all the undergrad textbooks on a subject. This could well be the case for findings from the 1960s, again, depending on your particular field of study.

  • David L Morgan added an answer in Social Science:
    What strategies do you use to present large amounts of qualitative data in academic articles?

    I'd like to hear the strategies you use to present large amounts of qualitative data in academic articles. Thank you! 

    David L Morgan

    Those are very good suggestions from Han Ping Fung. I usually recommend to my students that they try to organize their Results section around 3-5 basic themes because readers cannot keep track of more than that. Also, some of your major themes can have sub-themes, but if you try to present every one of those sub themes in detail, you will once again run the risk of overwhelming the reader.

    Another option is to create a tale where each theme is a row and three columns contain: the name of the theme, its definition, and very brief sample quotes to illustrate the content associated with that theme.

  • Julia B. Smith added an answer in Fixatives:
    How can I compare latent means in CFA without taking multiple groups or logitudinal measurement?

    I'd like to compare the means of some factors in my CFA, but these are all fixed to zero. What can I do?

    Julia B. Smith

    They are fixed to zero because they use z-scores to compute CFA and SPSS saves the z-score combined measure to the file.  Your easiest solution is to compute your own combined measure based on the information from the CFA.

       If all you care about is items going together, with no weighting, just use the mean operator in your computation.  If you want the items to be weighted, you will need to get the factor score matrix from your CFA to make your computations.

  • David Garofalo added an answer in Astronomy & Astrophysics:
    An old question that is still fresh: Is gravity a Newtonian force or Einstein space-time curvature?
    No gravitational wave was measured yet, no graviton was detected accordingly. On the other hand no space- time curvature was observable. There is no successful experiment to validate the current theories. What is the nature of the mysterious gravity? What is the velocity of this effect ?
    David Garofalo

    Dear Stephen, sidestepping your deep insights into the universe for a moment, could you also give us some advice on landscaping and maybe some insiders tips on plumbing?


  • Kåre Olaussen added an answer in Complexity:
    Are there 2-D extension of real number like complex numbers that is non-commutative?

    Quaterion is non-commutative but it is a 4-D type hypercomplex number. We also have Dual Numbers and Hyperbolic or Perplex Numbers but they are still commutative. Are there other 2-D hypercomplex numbers similar to complex number but non-Abelian?   

    Kåre Olaussen

    Anton> sigma(z) doesn't generate a(11) = 1/a(22) = a.

    What is your definition of  σzAccording to mine, and I think most others, 

    exp(t σz) = diag( exp(t), exp(-t) ) = diag( a, 1/a) with a = exp(t).

    I should have qualified the group further by specifying a>0. And the "origin" (the unit element) is, as always,  t=0 or a=1. You should not be distracted by the missing i in the exponent; this is just a very special convention used by physicists when they want to generate unitary representations with hermitian generators. But Lie groups are much more than that, even to physicists.

  • Dawid Szutowski added an answer in Newspapers:
    Do you know any news, data and insight databases?

    I look for a database (preferably free one), which covers newspapers, journals, magazines, television and radio transcripts, photos, etc. I study different innovation announcements of European companies. For a long time I have been using Factiva by Dow Jones but unfortunately I cannot subscribe it anymore.

    Dawid Szutowski

    Dear Yulia,

    thank you very much for the answer! I also think that social media may be a very rich source of information.

    Best regards

  • Julia B. Smith added an answer in Multilevel Modeling:
    Please guide for the sampling mechanism for multilevel modeling (two levels, individuals and department)?

    How to select sample for multi level modeling? Specifically for a two level modeling

    Please recommend a book that address all the basis/ preliminary issues related to multi level modeling including

    how to select sample and how much sample size is required at each level,, how to collect data then, how to enter data for multi level analysis, its interpretation , softwares etc etc

    Julia B. Smith

    Hoffman's book is good for looking at change within person, but it can be tricky to apply to persons nested within organizations.  My go-to source for multi-level modeling will always be Raudenbush and Bryk.  Their most recent book is this one, but if you search on either Raudenbush, Steve or Bryk, Anthony you will also find articles on the issues involved in multi-level modeling:

    Raudenbush, S. & Bryk, A. (2001).  Hierarchical Linear Models: Applications and Data Analysis Methods (Advanced Quantitative Techniques in the Social Sciences).  Thousand Oaks CA: Sage Publ.


    I also became a fan of Robson and Pevalin's book the last time I taught HLM:

    Robson, K. & Pevalin, D. (2015) Multilevel Modeling in Plain Language.  Thousand Oaks CA: Sage.


  • Gabriel OMONIYI Ayeni added an answer in Clinical Assessment:
    If the results were statistically significant, does it mean that it is should be clinically important?

    For example, two treatments could be statistically significantly different, but their clinical effects may irrelevant ?. In this case how should we interpret the results?

    Gabriel OMONIYI Ayeni

    Statistically significance does not necessarily mean clinical significance. it mainly reflects the true outcome of a research process as originally designed. It is also a function of other factors such as the sample size, degree of validity, reliability, sensitivity of clinical research instruments

  • Nita Tchabasvili added an answer in Suicidal Ideation:
    Does anyone know the scores for Beck Scale for Suicide Ideation ( BSS)? which scores are high, middle or low in this inventory?
    Nita Tchabasvili
    Thanks for your halp Beatrice
  • Mohamed Mousa added an answer in Power Electronics:
    What are the current research areas for pursuing Master Thesis in the field of Power Electronics?

    Which research area in Power Electronics will make for a good Master thesis in the field of Power Electronics? Would be obliged if someone can inform me about the ongoing scope of such research projects. I am searching for a good research proposal for my Master thesis in the domain of Power Electronics. 

    Would be obliged, for your help.

    Mohamed Mousa

    Dear Muhammad Munir;

    If you want any thing else, please do not hesitate to contact me. 

  • Abdelhalim Zekry added an answer in Copper:
    Cable of which dia meter I should use for the following conditions.

    Full Load current = 125A

    Length = 150 m

    Temperature = 40C

    Cable will be used underground at depth of 1m

    Note. Cable will be 3.5 core , armoured copper conductor.

    Abdelhalim Zekry

    Dr Dreher answered the question and gave an estimation of the cross section according to the the maximum voltage drop on the the length of the cable delta V = IR, since delta v and I are given one can estimate the R. Since R= Roh x L/A , one gets the cross esctional area of the cable knowing the resistivity  Roh of the copper.

    There is standard cables sizes for certain nominal current carrying capabilities under specified working and installation  conditions. The cables specified in the tables given in the following Link can satisfy your requirement and you can choose a one suitable from them:http://www.aeicables.co.uk/literature/CurrentRatings.pdf

    This is an example and there are other tables given by other companies.

    After inspecting the table i found that the estimations of Dreher are quite acceptable.

    wish you success

  • Ali Veismoradi added an answer in Polyamides:
    How can dissolved nylon 11 in 1-4 butanediol ?

    A solution was prepared from 0.6 gr polyamide 11 and 4.5 gr 1-4 butandiol in 165 degree. but the pellets of polyamide did'nt dissolved. Can we use this solvent for polyamide 11?

    Ali Veismoradi

    Dear Marius

    thank a lot for youe helping.  It's  really  useful for me.  Do you have any idea  for using reflux system  to dissolved  this polymer?  I'm  glad ti know your suggestions.  Thanks alot

  • Rafik Karaman added an answer in Autophagy:
    Link between ERK1/2 activation and LC3-II, any comments?

    Who could give me information about a possible link between ERK 1/2 activation and autophagy?

    Rafik Karaman

    Dear Patrice,

    The following recent paper describes the link between ERK1/2 activation and autophagy:

    Sci Rep. 2015; 5: 13013.
    Published online 2015 Aug 12. doi:  10.1038/srep13013
    PMCID: PMC4532997
    Rhus coriaria induces senescence and autophagic cell death in breast cancer cells through a mechanism involving p38 and ERK1/2 activation
    Hussain El Hasasna,1,* Khawlah Athamneh,1,* Halima Al Samri,1,* Noushad Karuvantevida,1 Yusra Al Dhaheri,1Soleiman Hisaindee,2 Gaber Ramadan,1 Nedaa Al Tamimi,1 Synan AbuQamar,1 Ali Eid,a,3 and Rabah Iratnib,1
    Author information ► Article notes ► Copyright and License information ►
    Go to:
    Here, we investigated the anticancer effect of Rhus coriaria on three breast cancer cell lines. We demonstrated that Rhus coriaria ethanolic extract (RCE) inhibits the proliferation of these cell lines in a time- and concentration-dependent manner. RCE induced senescence and cell cycle arrest at G1 phase. These changes were concomitant with upregulation of p21, downregulation of cyclin D1, p27, PCNA, c-myc, phospho-RB and expression of senescence-associated β-galactosidase activity. No proliferative recovery was detected after RCE removal. Annexin V staining and PARP cleavage analysis revealed a minimal induction of apoptosis in MDA-MB-231 cells. Electron microscopy revealed the presence of autophagic vacuoles in RCE-treated cells. Interestingly, blocking autophagy by 3-methyladenine (3-MA) or chloroquine (CQ) reduced RCE-induced cell death and senescence. RCE was also found to activate p38 and ERK1/2 signaling pathways which coincided with induction of autophagy. Furthermore, we found that while both autophagy inhibitors abolished p38 phosphorylation, only CQ led to significant decrease in pERK1/2. Finally, RCE induced DNA damage and reduced mutant p53, two events that preceded autophagy. Our findings provide strong evidence that R. coriaria possesses strong anti-breast cancer activity through induction of senescence and autophagic cell death, making it a promising alternative or adjunct therapeutic candidate against breast cancer.


    Kinases play an integral role in the inception and execution of autophagy. Several recent studies implicate the mitogen-activated protein kinase p38 and ERK in autophagy and ER stress responses. In fact, ERK was shown to induce autophagy in response to anticancer agents, such as soyasaponins in colon cancer cells55, dendropanoxide (DP) in human osteosarcoma cells56 and capsaicin in breast cancer cells50. In the case of capsaicin, ERK activity was also shown to be required at the step of maturation of autophagic vacuoles and inhibition of ERK resulted in increased LC3-II indicative of degradation blockade50. Similarly, Wong and collaborators showed that sustained ERK1/2 activation act as an upstream effector controlling both autophagy and apoptosis in response to high level of intracellular ROS, triggered by a small molecule compound referred a C1, and that its pharmacological inhibition blocked the C1 induced autophagy and apoptosis57. Also, inhibition of ERK was associated with a decrease in autophagy and increased cellular sensitivity to tumor necrosis factor-α (TNF) in breast cancer MCF-7 cells58. As for p38, there are controversial data as for whether it promotes or inhibits autophagy. Activation of p38 was shown to positively regulate autophagy by induced by bromelain59 and capsaicin50 in breast cancer or resveratrol in hepatocellular carcinoma cells60. Conversely, Thyagarajan et al., showed that induction of autophagy byGanoderrma lucidum in colon cancer cells, requires the inhibition of p3861. In the present work, we showed that R. coriaria induced a sustained activation of p38 and ERK1/2 in MDA-MB-231 cells. Moreover, the activation of these MAPKs occurred as early as 12 h post-treatment, a time at which autophagy was detected, as revealed by the accumulation of LC3-II. Interestingly, we found that activation of p38 was completely inhibited by 3-MA or CQ, hence suggesting that p38 activation is involved at all stages of autophagy, i.e. (i) formation of autophagosomes and (ii) fusion of autophagosomes with lysosomes leading to the formation of autophagolysosomes. We also found that only CQ reduced significantly the level of ERK1/2 phosphorylation thus, suggesting that ERK1/2 activation intervenes only in the process of the maturation of autophagolysosomes. The question as to whether the p38 and ERK1/2 acts in concert or independently in the process of autophagolysosomes maturation still remains to be eludicated. It is noteworthy to mention that similar mechanistic observations were reported. For example, it was recently shown that p38 is involved in autophagosomes formation, while ERK1/2 modulates the maturation of autophagolysosomes49.

    There are an increasing number of reports that provides compelling evidence linking cellular senescence and autophagy. Most recent evidence came from the work by Qi et al. (2013). They showed that pharmacological inhibition of autophagy by either 3-MA or CQ blocked senescence induced by pseudolaric acid B, a natural compound isolated from Pseudolarix kaempferi, in murine aneuploidy fibrosacroma L929 cells62. More evidence supporting the notion that autophagy is required for senescence comes from the work of Knizhnik and collaborators. They showed that senescence induced by the chemotherapeutic drug temozolomide (TMZ) was completely abolished by 3-MA in LN-229 glioma cells63. Here, we showed theR. coriaria induced both senescence and autophagy in breast cancer cells. We also showed that while autophagy was induced starting 12 h post-treatment, senescence however, become detectable only after 48 h treatment and increased over time. Most interesting is that inhibition of autophagy by CQ markedly reduced the ratio of senescent cells. Hence our work adds supplementary evidence supporting the notion that autophagy can be a prerequisite for cellular senescence.


    Hoping this will be helpful,


  • Mohammad Zim asked a question in Lysis Buffer:
    What is the best lysis buffer for sf9 cells ?

    I'm trying to isolate proteins from sf9's cytosol but I have a problem with cell lysis .

    Any idea for lysis buffer or lysis protocol ?

    PS: we do NOT want to centrifuge cells then lyse them .. we harvest them using cross flow filtration and then add lysis buffer to retentate ..

    in the other words, we want to keep cells within cross flow and lyse them to proceed next step - Clarification -


  • David L Morgan added an answer in Well-Being At Work:
    Can I conduct a mediation analysis with two variabels measuring the same construct (baseline/follow-up) and a mediator (post intervention)?

    My aim is to investigate why an intervention known to increase well-being works. I identified a plausible moderator variabel and currently plan a longitudinal study to test my hypotheses.

    My question is: do I need an experimental design in order to create variance and a predictor variable? group --> intervention yes/no --> mediator post --> well-being follow-up

    Or is it possible to conduct a mediation analysis without a control group? well-being baseline --> intervention --> mediator post --> well-being follow-up

    Thanks for your ideas, I'm really stuck here ...

    David L Morgan

    Your statistical program will not "know" when any of your variables were measured, so you can specify a standard mediation model for your final variable. As Laura points out, however, this will not make sense unless your mediator variable was truly available to operate at the time your intervention was carried out. In particular, if you can argue that the values on the mediator variable did not change between the pre- and post-test that should be good enough.

    Still, your design is unusual enough that you are likely to face questions from reviewers about the time ordering of your data collection.

  • Haroon Rashid added an answer in Biotechnology:
    What is the future of bio medical engineering?

    biomedical engineering is important for millions to help heart patients and all  tools to help artificial organs ,which are now required by millionsThe human heart is a pump that is made of muscle tissue. A special group of cells
    called the sinus node is located in the right atrium. The sinus node generates
    electrical stimuli that make the heart contract and pump out blood. The normal
    human heart beats about 75 times per minute (i.e., about 40 million times a year) –
    i.e., the heart pumps 5 l of blood per minute. The normal systemic blood pressure is
    120/80 mmHg. The mechanical power (calculated by multiplying the pressure by
    the flow rate) of the human heart is about 1.3W. However, to provide this
    mechanical power, the heart requires 10 times much higher rate of energy turnover,
    owing to its low mechanical efficiency (less than 10%).
    However, the development in biotechnology can open the opportunity for
    tissue engineering (a branch of biotechnology) – a prospect of saving people with
    extremely complex or irreversible failure heart will still be realized using mechanical
    heart support devices.
    During the last half-century, various blood pumps were introduced into
    clinical practice, which can partially support or replace the heart during openheart
    surgery or considerably for a longer time period until heart recovers or
    until transplantation is performed. Several millions of people owe their health
    and lives to these devices.so what are the future of this topic now?

    Haroon Rashid

    Hello. Well I guess biomedical engineering has a great future ahead of it. As far as dentistry is concerned, the division of dental material science is a sub-division of biomedical engineering in many countries specially north America. A lot of research is being carried out in that field e.g. surface characterization of materials etc.etc and I guess a lot more will be done and newer results will be obtained.


  • Luis Miguel Constantino added an answer in Cinchona:
    Can anyone explain the cultivation of cinchona ?

    Also why there are only 3 species have been cultivated.

    Luis Miguel Constantino


    There is a good compendium on Cinchona pubescens (quinine tree) in this link that can answer your question.



    Luis Miguel

  • Renee Wever added an answer in Biomimicry:
    Anyone interested in Biomimicry?

    I am working on my PhD thesis. Looking for professionals to work with. 

    Renee Wever

    I have two possible leads for you:

    1. Recently, a project on nature inspired design with industrial partners was finalised at Delft University of Technology. The final report can be downloaded for free at www.natureinspireddesign.nl. 

    2. A recent PhD defence on sustainable design in Turkey did questionnaires and case studies with Turkish companies. These may also be interested in biomimicry. Full text of thesis can be found: http://repository.tudelft.nl/view/ir/uuid%3A60c56fba-987c-4155-9ba8-229d5c2a1c3b/ 

    best of luck!

  • Faris Alshubiri added an answer in CSR:
    Do you think CSR has to be the same meaning in all countries?

    CRS has a lot of approaches, my question is if you think CSR has to be the same meaning (not practices) in all countries?

    Faris Alshubiri

    Dear Katia Beatriz Villafán Vidales


    Yes I agree what Krzysztof Zięba  said.

    Best Regards

  • Aurelio David added an answer in Public Understanding of Science:
    Any bibliographical reference on how to measure/evaluate laypersons' understanding of technical/complex issues?

    In particular, I need to develop a questionnaire to submit to laypersons.

    Aurelio David

    Dear Mr. Conroy and Ms. Strekalova. Thanks to your suggestions I will surely improve the still vague conceptualisation of "understanding", and make it more precise. I am studying how different media used in participation processes in urban design make people more or less aware of the complexity of the issue at stake, which is usually addressed by a team of experts.