Selection - Science topic

Dear Colleague,

I hope this message finds you well. Determining the optimal puromycin concentration for selecting non-small cell lung cancer (NSCLC) cell lines transformed with lentivirus requires an initial kill curve experiment to identify the lowest concentration that effectively kills untransfected cells while sparing the transfected ones. Here is a detailed and logical approach to determining the best puromycin concentration:

Steps to Determine the Optimal Puromycin Concentration

Example Protocol

By following these steps, you can accurately determine the best puromycin concentration for selecting NSCLC cell lines transformed with lentivirus, ensuring effective selection of transduced cells while minimizing toxicity.

Should you have any further questions or require additional assistance, please feel free to reach out.

This protocol list might provide further insights to address this issue.

Thank you Muhammad Irvan . Appreciate the feedback. Seems like is getting more popular.

Hello again Nico,

DId you have your pilot study respondents rate each of the purported utilitarian products on the hedonic dimensions/attributes, and vice versa?

Otherwise, how could you be certain that an out-of-category product wouldn't rate higher than the in-category products? (Even if you thought that such an outcome was unlikely.)

If you must reduce each set, then likely you would opt for utilitarian products which had highest average ratings across the five utilitarian dimensions _and_ (ideally) lowest average ratings across the five hedonic dimensions; the opposite would be the target for hedonic products.

I don't think that PCA would be productive here, since any observed coalition of products might be due to some completely different attribute, and not necessarily the 5 (utilitarian) and 5 (hedonic) you've identified.

Good luck with your work.

Can u pls suggest me a selective media for deinococcus isolation

Hey Lindsay Kelly , I saw your question today and it's exactly my question nowadays. Did you have to settle any parameter?

Hi, I am working on the analysis of black lion tamarin populations sampled from GBS data. The dataset contains 2597 polymorphic loci. I ran PCAdapt using all loci and found around 200 outliers. As suggested also run un Bayescan without population stratification. However, there are no outliers in this analysis.

I'd be thankful if anyone could give me some insight into why this is happening, or if they could suggest a parameter that I could alter to test it. Jose Alberto Lopez-Aleman Olga Kozhar

You may read this article, I think it may help you, based on practices.....

Hi,

As Nokuthula suggests, usually, peoples use 100ug/ml zeocin concentration for P. Pastori's culture.

The high concentration of Zeocin could help in the transformed clone screening. You can use 100-300ug/ml of Zeocin. 200ug/ml worked for me.

To see the colonies on Zeocin plate, the proper transformation protocol should be followed and consider the factors affecting transformation efficiency like

Way the competent cell prepared

nature of the recovery medium

Cell density

DNA concentration

Best

Plesiomonas spp. is actually easy to isolate through the use of most media that are routinely used in the laboratory such as SBA or CHOC agar. The most convenient screening procedure to do is an oxidase test on such media for most strains of plesiomonads ferment lactose – as their delayed positive reaction. However, even if specialized media are not often recommended for the isolation of plesiomonads, the use of inositol-Brilliant green-bile salts (IBB) is claimed to be highly efficient in enhancing the isolation of Plesiomonas spp. from both clinical and environmental specimens.

As for the enrichment of Plesiomonas spp., some studies stated that alkaline peptone water (APW) which has a pH 8.6 can be used, as well as Gram-negative broth. (more effective when ratio of coliforms to plesiomonads is elevated; usually during chronic diarrhea). In addition, another enrichment broth is claimed to be more effective than APW and is said to be the enrichment of choice or is more recommended for the isolation of plesiomonads, which is the bile peptone broth.

References: https://cmr.asm.org/content/29/2/349#ref-152

Hi Sven Falkenberg

Unless I'm missing something and these are your only constraints (e.g., you need not worry about future pairings), then the single period pairing problem can be modeled as a bipartite maximum weight matching problem. You can set the value for pairing the same element with itself to small enough value to enforce that self-matchings will not occur.

This problem is also known as the assignment problem and can be solved with an LP solver.

You can also apply the Hungarian algorithm:

Best regards,

Juho

I'm interesting..

Ideally you would need to simulate your data under the assumption of neutrality or selection under a relevant demographic scenario, then run the test on the simulated datasets to estimate the rates of false positives and false negatives given a threshold. A software like SliM3, msms or discoal can be used to perform these simulations. Comparing the results from different approaches as suggested earlier is also valuable.

Once you have your list of genomic windows, you might want to perform permutation tests to see how likely it is that you detect MYB by chance given that you have n windows classified as selected. The R package regioneR may be helpful for that.

Good luck!

I performed my own kill curve analysis using this Lentivirus: https://shop.essenbioscience.com/products/nuclight-red-lentivirus-reagent-ef1a-puro

Concentrations were 0, 2, 5, and 10ug/mL Puromycin. 2ug concentration was ideal in this scenario, though 5 and 10 work as well given more time

@Mubashar Hussain Shah Yes, questionnaires are tools for obtaining specific information from some fields of study. But I think, It is necessary to have a general "picture" of the researched area, in order to determine relevant components, their relation. That can be got by means of some kind of "brainstorming", where people expose their ideas around the topics. And discussions can act as a mean for that aim. On that basis, the researcher can identified some trends, regularities, structures, functionalities, which can be detailed later, using other methods, techniques and tools.

i'm interesting and following the answers

Hi Prasanth and Andreas,

I will provide more info on the experimental setting. So I am working on wild type mice and the neurons are first isolated and plated. Afterwards I am aiming to transfect them with 1) pX330 plasmids expressing cas9 and the gRNA for my specific target and 2) a selection vector harboring the sequence that the gRNA should recognize and cut. It also contains a frameshifted non-functional blasticidin resistance gene. When the cas9 cuts the sequence on the plasmid a frameshift will repair the blasticidin gene.

Before starting the experiment I want to find out which is the lowest concentration of blasticidin needed to kill cells without blasticidin resistancy. I tried concentrations ranging from 1-8 ug/ml and they all had their axons degrading and looked dead or dying atleast but did not detach from the well.

In this case, can I trust that this kind of selection would work? That when replating them the transfected neuron with the resistance gene would again attach in the new well but that the dead ones would float? Or should I just go higher in blasticidin resistance risking toxicity to my transfected cells?

Best,

Linn

I normally added puromycin after 48 hours of post-transfection,.

Many thanks dear Michael for your valuable answer.

Gianluca,

Thanks for the feedback. My comments below:

1. Pluralism in the MS just means acknowledging measured contributions of the main evolutionary forces: selection, drift, gene flow and mutation.

But there is no mention of mechanisms for the origin of mutation and their spread through populations without selection, drift, or gene flow.

2. Either a structure has an effect on the fitness of the organism, then being either maladaptive or adaptive, or it hasn't, thus being non(ad)aptive. In the latter case, it just does not have any function (neutral).

If you wish to define function that way.

3. Exaptations (shifts of function from either an adaptation or a nonaptation) are real stuff, not dreams.

Not so sure about that.

4. Gene duplications, pseudogenes and genetic shifts of functions are the results of historical events, not dreams.

Sure, but the dreaming comes in when people invoke ‘selective pressures’ or other such without any evidence.

5. Bird feathers are …the end result of a historical process made of contingencies and interactions between biological systems and environments:

true of anything (and anyway, a feature is really two feathers in one)

6. Gould ….. aimed to contrast adaptationism by reinforcing structuralist themes, which seems quite the opposite of what you're saying.

OK. Although I think he just further muddied the waters of Darwinian evolution. But that is just a personal opinion.

Cheers, John

Your question is very wide and abroad from a research idea. See, science and specifically computer science has multiple disciplines. Each one tries to solve a wide range of problems, for example, image processing, parallel processing, operating systems, artificial intelligent and so on. In each one, there are many (may be more than 10 ) subfields, which application may be used into another disciplines (such as AI-> Machine Learning-> classification-> disease diagnosis !).

What I think you should do is the following - if you are talented and hardworker, and motivated to research big questions:

1- Target a question , ask as much as possible, with the time you will ask for little effective questions ;-)

2- Check available solutions and make either official literature review or for your own notes.

3- Explore thoughts other than performance.

4- Come up with your own thought to solve the question.

5- Work on performance and other related things.

Wish that helps

All the best

Allele frequency largely depend on the choice of your markers per se. It is difficult to make any conclusion without further information on the number of markers you are using, their repartition across the genome, and so on... What about HW disequilibrium?

Potentially beneficial recessive mutations will hidden by dominant wild type alleles, unless you can find a way to self the crop.

I would have loved to help, but i dont know

Protein family refers to a group of structurally similar proteins which are mutually evolutionary and encoded in corresponding gene families.

A classification of proteins in families due to their amino acid sequence and the architecture of the sequence-internal protein domains helps in the theoretical understanding of the evolutionary development of these protein families.

Predicting 35% of the variance is no small feat! That implies a correlation between test results and later performance of about r = .60. Given that many factors contribute to one's success (not to mention randomness in the ratings), that's huge.

The general rule is that if you have a battery of valid tests and you start to take tests out, your predictions will become less accurate. More measurements means more accurate predictions.

As for anxiety and fatigue - well, if a person tends to choke under pressure or quickly get too tired to function, that person probably won't make a very good pilot. Think about it.

area of lightining

Thank you so much. Mr. Heinz Dorr.

Thank you

Thanks

Hi,

pSG5-FLAG-CaMKKbeta rat S100A, S495A and S511A (Plasmid #33320)Insert: Calcium/Calmodulin dependent protein kinase kinase beta ( Camkk2 Rat )

Tags: FLAG

Expression: Mammalian

Mutation: S99A, S494A, S510A

Use:

Deposited by: Anthony Means

(from this link:https://www.addgene.org/search/advanced/?q=PSG5&page=2)

Any calculation that involves lesser degree of dilution will be always be more accurate . For example , net plot yield converted into per hectare yield will be more accurate compared to per hectare yield , based on yield parameters of few plants in a given plot (since  you dont  consider the yield translation to all plants in a given plot )  , then converted into yield per hectare ... For sure , two different results will come up ..

Thanks for your help Anupama.

wow thanks a lot Mr. Sébastien Fernandez... bless you :)

First order elements suffer from shear locking (if fully integrated) or hourglassing (with reduced integration) and may suffer from volumetric locking.

If your solution is expected to be smooth, second-order is usually a better choice. Second-order elements may have problems in contact and when deformation is very severe.

Details also depend on your FE software because each program has a different selection of elements.

Any reasonable introduction to FE should discuss the implications of this choice in detail.

Historically, we typically used three things: (1) OCP measurements (as discussed above), (2) electrochemical equilibrium or E-pH diagrams (aka, Pourbaix Diagrams), and (3) cyclic voltammograms (CVs, from below hydrogen evolution to above oxygen evolution at a high scan rate). However, it really depends on what you want to know (measure). If you want to do linear polarization resistance (LPR) to estimate corrosion rates via the Stern-Geary approximation, then only +/- 50mV wrt OCP should be sufficient. For estimation of Tafel kinetics, a large range is required, as discussed above (OCP +/- 250mV), if you want to know about the passive current density and passive film breakdown, then you want to scan to potentials above those that would cause pitting in a halide containing solution. However, if the pitting potential is greater then the oxygen evolution potential, you will not be able to measure it accurately. To measure the OCP, all you need is a reference electrode and a meter with an input impedance of greater than 1E10 ohms. Any electrochemical reaction with a fixed potential wrt the hydrogen evolution reaction can be used as a reference electrode, but they are commercially available and inexpensive. Of course, you can readily make your own (e.g. see Ives and Janz, 1961). Most commercial voltmeters have an input impedance of 1E6 ohms and require too much current for accurate measurements from a reference electrode. However, you can easily fabricate a unity gain buffer amp (aka voltage follower) from inexpensive op-amps. Any introductory book on op-amp circuit design will show you how. I believe that Sawyer (Sawyer DT, Sobkowiak A, Roberts JL (1995) Electrochemistry for Chemists (J. Wiley & Sons, Inc., New York), Vol. 2nd Ed.) provides details on how to set up an electrochemical experiment.   

Dear Ranvir,

The ideal, as mentioned by Mr. Arpan, is to use the maximum switching frequency possible in order to reduce the harmonics.

However, the limitation is the temperature of the semiconductors switches. Higher switching frequencies mean higher switching losses. You'll have to estimate the total losses (switching and conduction ones) and semiconductor junction temperatures according to the information provided in the switches data sheet (Eon, Eoff, Erec, VCEsat, Vf, Rthj-c, Rthc-s) and the heatsink and cooling system you are intended to use (Rths-a).Then you'll be able to compare with the maximum allowed operation temperature of the junction  (Tvj, usually 125 ºC).

The process is iterative, but a simple MATLAB script  should solve your problem. 

I hope this information can help you in your design.

The first factor is the planned application and type of loading. Most commonly the powder metallurgy composites are intended as wear resistant materials. Therefore main factors will be hardness and fracture toughness which in their turn are determined by the hardness and fracture toughness of hard component as well as the ductility and wetting ability of the matrix metal. Also the structurally stable matrix should be selected properly to prevent pulling out the hard particles during wear

Dear Dr Esteftah ElKomy,

greetings, many thanks for your question. It is interesting to answer for your question from breeders "plant breeding" point of view.

I think if you have a wide population you can select first individuals "selection"

Then try make wide crosses between them and neglect the self crossing as make inbreeding depression "you will face low yield and growth" 

and try select for economic traits that important for consumers 

DNA markers is the best tools and you need to select the MAS marker assisted selection i.e,. SSRs, SNPs, ESTs

for enhancement the DNA markers I think you could find that in previous work.

with best regards

Khaled

First, you have to analyze the splitting patterns and J constants in order to distinguish among the proton signals of the meta-, ortho- and para- isomers. After that, you will be able to integrate and compare the relative integration and thus knowing the proportion. 

Phenomenology is a paradigm, ethnography is a domain of knowledge and GT is a method and its product of knowledge. So, I can approach a theme of ethnography (customs, traditions, values of ethnic?- groups) from a phenomenological perspective and I can develop a GT on the chosen theme.

Hello Viji I need full protocol. From starting to result. Thank you.I will try MEA media

hi Leila

this error could be due to divergence or very slow convergence or using user subroutine UMAT with some mistakes.

explain more about your model, so may be able to help you

regards

When you click save as there is a little drop down menu with different format types. The options (button with 3 dots and some lines, next to the drop down menu) allows you to change the codec. When I've needed to save videos for use in powerpoint in the past I've just tried several different file and codec types until I get something that plays. It usually doesn't take more than a few minutes to get something that works.

NSGA-II is the best for arriving pareto front and to find the best compromising solution among the available pareto solutions use methods like TOPSIS, AHP, PROMOTHEE etc

Hello Yousef,

That is not an easy question to answer. I think it would be best to define a project and study different aspects including environmental, social, technological and economic to make sure all stakeholders benefit. We worked on a similar project, evaluating the impacts of superfast broadband in rural areas of Gloucestershire and Herefordshire. We worked with BT and Fastershire, I cannot share more info due to the confidentiality but it would be a good idea to contact(email) Prof. Ali Parsa in (Dean of School of Real Estate and Land Management at the Royal Agricultural University, UK or simply ask your question in the project on our profile in Researchgate (there are some updates by our team) so he can see it and probably can share some information with you.

You need to run several models with different parameters combinations and you need the results in raw format (nor logistic or cumulative) . You need to create a script file (*.csv ) with the complete route to the occurrences points,model results and the lambdas for each run model.

Something like this:

C:\documentos\papers_chile\maxent\new_paper\maxent\puntos_belloto\points_belloto.csv,C:\documentos\papers_chile\maxent\new_paper\maxent\results\belloto\autofeatures\Beilschmiedia_miersii.asc, C:\documentos\papers_chile\maxent\new_paper\maxent\results\ belloto\autofeatures\Beilschmiedia_miersii.lambdas

C:\documentos\papers_chile\maxent\new_paper\maxent\puntos_belloto\points_belloto.csv,C:\documentos\papers_chile\maxent\new_paper\maxent\results\ belloto\H_thr_1\Beilschmiedia_miersii.asc, C:\documentos\papers_chile\maxent\new_paper\maxent\results\ belloto\H_thr_1\Beilschmiedia_miersii.lambdas

...And so on. 

When you are done building the *.csv file, you go to ENMTOOLS to the model selection menu and point to the file you just created. I usually get a couple of errors because of typos in the *.csv file. Do not panic, just check your file. 

A detailed tutorial on how to do this is in the manual provided with ENMTOOLS. 

Depends on many factors;

1.  Extraction method.

2.  Detector response

3.  Sample matrix.

4.  Other..

Your question is MUCH to general to answer!

Dear Ren,

That really depends on your objectives, costs, availability of data on species, and many other factors. I think you should clarify your question more.

Hope that helps

Abdelbaset -

When you use probability-of-selection design-based methods for sampling, generally for finite populations, though being finite is not always necessary, the estimation technique is determined by the randomized sampling design.  There is a school of thought which says this is too artificial, and regression modeling of the population is important in itself, not just for helping to establish the best probability-based design.  There is an interesting review of these thoughts here:

    Ken Brewer's Waksberg Award article: 

.....

    Brewer, K.R.W. (2014), “Three controversies in the history of survey sampling,” Survey Methodology,

(December 2013/January 2014), Vol 39, No 2, pp. 249-262. Statistics Canada, Catalogue No. 12-001-X.

http://www.statcan.gc.ca/pub/12-001-x/2013002/article/11883-eng.htm.

    He believed in using probability sampling and models together, but he explains the different approaches, the pros and cons. 

....

In your case, you appear to be referring to the most popular of the rigorous quantitative techniques for finite population sampling:  a randomized design, where the probabilities of selection are used in estimates of totals, means, and sometimes proportions, and estimates of variance and bias.  The simplest case is discussed in my encyclopedia entry here:

 https://www.researchgate.net/publication/262971887_SURVEY_WEIGHTS

For a finite population there is this consideration:

 https://www.researchgate.net/publication/262970761_FINITE_POPULATION_CORRECTION_fpc_FACTOR

.............

To understand much of this better, it may be helpful for you to study the Horvitz-Thompson estimator, as it may convey the connection between randomized selection of a sample and the use in estimating a total better than others:

 https://onlinecourses.science.psu.edu/stat506/node/16

If you are new to all of this, however, you might first look at simple random sampling:

 https://onlinecourses.science.psu.edu/stat506/node/5

I think that these Pennsylvania State University online materials are often very good.  Here, you may just want to start with this:

 https://onlinecourses.science.psu.edu/stat506/node/1

Best wishes - Jim

PS -  When using auxiliary data to help improve estimates, one may use "calibration."  In this context, "calibration" means that the survey (design-based) weights are modified to form calibration weights, which may also include regression weights.  You can find a few notes on the concept of calibration weights in the following:

 https://www.researchgate.net/publication/261508465_Use_of_Ratios_for_Estimation_of_Official_Statistics_at_a_Statistical_Agency

I agree with the above explanations. Neutral value should not be removed to maintain the credibility of the scale and reproducibility of results.

Regards 

SM Najim

Onome,

From the Failure module, you can choose the type of failure as count, and then choose the probability distribution you want from every resource to follow.

I've used JmodelTest in the past and have found it helpful. Once the analysis is finished, the software will compile the results into a summary table. In the table, you can use multiple scores in different columns to identify the most relevant model for your dataset.

It is important to store this information since not all models and parameters are accessible in the phylogenetic tree generation programs.

Hi Patrick,

Unfortunately a disadvantage of Plaxis is this problem. But you can solve problem with an innovative solution, if you want axial and bending moment in the plate element:

- select some stress points for monitoring

- after completed your model, extract your history in the excel file

- use this formula based on strength material law: 

Sigma1=(My/I)+(Axial force/A)

Sigma3= (My/I)-(Axial force/A)

you have two equations with two unknown parameters.

Dear Dr Razzeghi

please tell me how and for what problem you want helping?

Dear Amor

Every day we receive a number of emails from Journal have no history invited us to publish a paper, in spite we hope to encourage the new Journals to appear  and contribute in publishing the scientific research results which lead to scientific development . But the appearance of not reviewed paper from this Journal and publish wrong data may lead to harmful confusion to the wide range of researchers, so we must be careful when we chose Journal to publish or to take reference. I hope to good new Journals to have shining future and be a stone in the scientific building .

Predatory publishers aimed to quick economic benefits without care for the quality of articles and they ask high charges for publishing.

In another hand, maybe we read a random list of Journals described as predatory within a process of competition between old and new publishers.

Good Luck

thank you all so much! Was big help ! 

It is possible to observe transgressive segregants in any segregating generation.

Transgressive segregation occurs due to the accumulation of alleles with positive (or negative) effect upon the trait being measured, either through additivity, dominance, or epistasis, such that an individual possessing a particular combination of alleles will display a phenotype beyond the range observed in the parents of the original cross. Since such favorable combinations of alleles can occur in any generation, transgressive segregation can be observed in any segregating generation.

Thanks Stalin

Jeraltin:

I believe you can but the attached related studies can confirm for you. 

Best regards,

Debra

Thanks everyone for your helpful answers. I switched to Tantalum as electrode material and the problem is solved.

L9 Taguchi optimization with title (2015) "Clove oil nanoemulsion as an effective antibacterial agent: Taguchi optimization. Desalination and water treatment, Taylor & Francis, Impact Factor: 1.173, ISSN: 1944-3994, DOI: 10.1080/19443994.2015.1092893” is available via the link below!

See page 15 of the PAML manual, under the subsection "Tree file format and representations of tree topology". What you have looks correct to me. The manual suggests checking your labeling by loading your tree into TreeView. 

I've done some selectivity studies (habitat use and diet). My first suggestion is to avoid simply dividing use by availability as this ratio is unbound and biased to small sample sizes and either extreme.i use Jacobs index (based on Jurgen Jacobs Oikos paper from the 1970s. This and Strauss 1974 highlight why their methods are better than straight ratios. If you have data on lots of individual birds, then you can calculate a Jacobs index value for each habitat used by each  individual and then test these against a mean of 0 using t-tests. If not, the chi squared method (as described byJuan) or compositional analysis can be used.

Cheers

Matt

The method chosen for action research should first and foremost be a good fit with the context in which the research is being undertaken. Consider the context and participants, along with the ideological orientation of the research. For example, if it is an individual teacher in a classroom investigating aspects of their practice, then a practitioner action research approach fits best. If the research focuses on empowerment in an impoverished community, then principles of participatory action research fit best. It is common for action researchers to 'borrow' elements of different action research approaches that best suit the context in which they are conducting the research. For my doctoral research, I was an outside facilitator of action research who worked with educators in two early years settings on a topic of my choosing. In this sense, it was important to attend to key principles of collaborative action research, but also address the role of an external facilitator. Of key importance is that the action research cycles of questioning, gathering data, reflecting and deciding on a course of action are enacted systemically in the context in which you are researching. Different elements of action research may come in to play at different times depending on the context, the participants and the orientation of the topic investigated.

Three main methods of potash processing are heavy media separation, flotation, dissolution and crystallization.

Potash mineral flotation done in the saturated medium with aliphatic amines. but dodecyl sodium sulfate one of the anionic collector that use in potash flotation.

To improving of potash flotation with amines, adding 8 to 10 moles alcohol hexyl and octyl improves potash flotation capability significantly. If there are clay in the flotation, the clay absorb amine collectors. De-slimming of clay must be done.

Common frother that use in potash flotation is MIBC (methyl isobutyl carbonyl).

Flotation of the ore is done at neutral pH and ambient saturation.

Chemistry and temperature of saturated solution influenced on the contact angle and thus the flotation capability of KCl and NaCl. 

If the brine temperature increases of 18 to 37°C, the contact angle of potassium chloride, decreased.  Sodium chloride remains constant while the contact angle. 

The contact angle in the greater than 28°C are similar in both mineral. 

Dear Colin

Natural selection appear his effects through the viability and fertility of individuals in the population . good genotypes which suitable to the environmental requirements will be high fertility and have good viability so their offspring represent the normal genotype .

In other hand genotypes lived in environment with extreme changes cause mortality or low fertility and may be sterile so they will not contribute in the offspring of the next generation , or contribute in low percent , and referred as abnormal genotypes .

Good Luck

Dear Sami,

I guess that means you have a qBase+ licence in which case you can get support here.

There's a manual with info on the reference gene validation on page 46 but if that is not clear enough, I've found that the Biogazelle Tech support is pretty good.

Unfortunately, my licence expired so I can't lead you through it step by step.

Now for an actual response: it is trivially true that something about the processes that result in conscious experiences require both pre-conscious (or pre-emptive) signals and that the strength of these matter. This is regardless of whether or not a global workspace or global neuronal workspace exists. The pre-emptive part comes from the fact that we cannot be conscious of e.g., visual stimuli without neural firing in the PNS component(s) of the visual system. That the strength of signal matters is somehow trivial and yet complicated. One issue is that there are various theories in neuroscience concerning what a "signal" is. Ignoring action potentials that are nothing other than noise, there exist different theories concerning the nature of how spike trains or more simply action potentials "work". The brain is constantly active. For us to become aware of some visual stimulus, something has to change and unless virtually all of brain research is wrong, that something is mostly or entirely based upon action potentials. However, single action potentials don't really matter. What matters may be the rate at which sequences of action potentials generated by various neurons connected to another neuron's dendrite or dendrites (in terms of the cortex, the plural "dendrites' doesn't quite cut it; we are talking about tens of thousands of dendritic connections or more). Or it may be that the rate doesn't matter but the timing does. Or both. Or neither. Also, the most widely used neural model (the one upon which basically all others are somehow based on) doesn't work via all-or-nothing spikes. And there are other complications.

That said, we can demonstrate the triviality of signal strength by going to the PNS again. Specifically, nociceptors or "pain neurons". Most of the time that we experience pain it is mechanical (this covers everything from bumping your elbow to being having limbs chopped off). There are, however, other types (e.g., chemical and thermal), but there is in particular a rather unique kind of mechanical (presssure) induced pain- the mechanical/pressure pain that we experience due to mechano-insensitive nociceptors. These are interesting and ideal here because unlike most pain signals they do not begin as noxious. In order for mechano-insensitive nociceptors to generate a signal powerful enough to be perceived as painful, there must be an initially non-noxious pressure applied repeatedly and over time (tonic pressure) such that eventually the repetition causes mechano-insensitive nociceptors to encode a signal perceived as pain. Normally, things work the other way around. Stimuli initially perceived as noxious, whether from walking out into the freezing cold from a warm house or being pinched, nociceptors using A-fibers or C-fibers initially send a strong signal. Also, the noxious stimulus generally causes the same or mostly the same nociceptors to fire, and unless the stimulus is significant the repeated activation of these nociceptors will be modulated by the CNS (i..e, the CNS says "stop paying attention to these signals, we're doing fine"). Finally, most of the time signals from these nociceptors aren't consciously experienced.  So we require a sufficiently strong initial signal to experience thermal, chemical, & most mechanical stimuli as noxious, but for mechano-insensitive  nociception we the signals strength is locally modulated by repetition and time (i.e., no signal will be generated locally until the stimulus has been applied locally for a sufficiently long time interval and with a particular regularity).

The question "Is the Neuronal Workspace theory correct in assuming that there is a

"strength" difference between modules, or is there some other decision making process involved such as Pre-emptive Selection?"

Actually involves several questions. First, nothing about the particulars matter if the theory is simply wrong. Second, there must exist these "modules". Third, there is the question of whether or not pre-emptive selection is non-trivial, incompatible with either GW theory or GNW theory, or actually descriptive of the theory. Fourth, there is the question that, granting a suitably non-trivial definition of pre-emptive, is it or are other processes involved in the mechanisms underlying what determines what we consciously experience.

At the moment, I can't see a way in which "pre-emptive" could be defined non-trivially or interpret the way it is defined ("something must be 'known'", which suggests it is already something one is conscious of) such that it isn't paradoxical. Nor am I quite sure how the question actually relates to and distinguishes between GW theory, GNW theory, and "Neuronal Workspace theory". But I don't think much of cognitive theories involving (massive) modularity (in the evolutionary & cognitive psychology sense, i.e., "massive modularity" or extreme domain specificity). Also, as both GW theory and GNW theory require domain general mechanisms, and in fact are rather fundamentally based upon the idea of highly synchronized activity between nonlocal neural populations, I am not sure that how "modules' may play a role in these theories (thought I can imagine ways in which they might).

Hao - 

The best kind of purposive sampling for continuous data is when you have regressor data on the entire population, and can make use of the variance of the prediction error.  If you could use a reference(s) on that, I can provide it. 

Regardless of your sampling and/or estimation methodology, good stratification can improve accuracy. 

Cheers - Jim   

Yes I do, however, without any luck! I wanted to knock down my GOI using this construct. Initially I used Clontech's shRNA designing online tool and picked up 3 target sequences. With those I developed 3 different constructs, each targeting a separate sequence in the target mRNA. None of them worked! Takara recommends using upto 1ug/ml of Doxycyclin, but I went up to 40 ug/ml without any effect. I also tried to generate stably transfected cell line with this construct. I Initially did a kill curve for G418 and found that for my cells 0.5mg/ml is enough to kill 100% of them. However, once transfected and grown over time, I have cells growing in 1.5mg/ ml G418 without any knock down after treatment with various doses of Doxycyclin for 72 hrs. By the way, I always look for protein expression. Also, the inserts have MluI cut site and all three were cut with MluI, suggesting that I was not working with false positive clones.

Once I ordered some siRNA from Origene for the same GOI. Out of the three that they sent, one of them constantly give me 75-80% KD after 72 hrs. treatment. When I checked the sequence of this particular oligo, surprisingly I found that this one targets the same region as one of the shRNA in the pSingle that I cloned earlier. Target sequences for pSingle constructs were 19 bases long, where as these oligos were 25 bases long, with the first 19 bases from the 5' end matching exactly the sequences for the shRNA. 

This is altogether what my experience is with pSingle.

Gd luck!

In your survey, whatever the attributes you wish to discuss to be treated into fuzzy. Make an appropriate statistical analysis to fix membership values for those attributes. 

Positive selection: also called (Darwinian selection) variants that increase in frequency until they fix in the relevant population. The selective pressure that leads to this fixation is termed positive selection.

Negative selection: Also called purifying selection, it means that selection is purging changes that cause deleterious impacts on the fitness of the host.

Thanks Kelli for replying... Much appreciated

The question can be answered only when you specify "how small?". In finite sampling, depending on nature of the population(whether it is homogeneous or heterogeneous) various techniques exist for drawing the samples. One can always decide for optimal size. In field surveys or social surveys, usually if sample size is very large, occurrence of non sampling errors will me more resulting in spurious results.

Selecting the appropriate attributes that define each case is the most important and hard task to do. Case indexing is the 1st step in the case representation step in in CBR problem solving life cycle.... 

Do any believe case indexing can be better done in anyway than DB technology? Like defining the structure and description of each attribute within the case? Please share your experience.

Look up this paper:

Electrical and Electronics Engineering: An International Journal (ELELIJ) Vol 3, No 3, August 2014, DOI : 10.14810/elelij.2014.3304 43

INVESTIGATIONS WITH MODE DIVISION MULTIPLEXED TRANSMISSION

Devendra Kr.Tripathi*, Pallavi Singh, N.K.Shukla, H.K.Dixit