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.

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  • Voltage or current controlled device is a BJT? And what does "voltage controlled" and "current controlled" mean? Is this a property of the BJT?
    This discussion is old as the very bipolar transistor... but it is still interesting...

    In my opinion, a BJT can be controlled either by voltage or current depending on the situation. If we want a maximum gain (the case of amplifying stages), we apply a small (to be a linear device) AC voltage (e.g., ±100 mV) with an additional appropriate DC biasing voltage (e.g., 0.65 V) directly to the base-emitter junction; then we can consider the BJT as a voltage-controlled device. The problem is that the base-emitter junction, like a diode n-p junction, is not so suitable for a voltage control since it behaves as a voltage source (more precisely, as a constant-voltage nonlinear "resistor"). Figuratively speaking, there is a conflict between two constant-voltage devices connected to each other (an incorrect arrangement). The dual incorrect arrangement is if we try to inject a current into the BJT collector (the "dynamic load" odd idea).

    If we want a maximum input voltage range, we drive the BJT base-emitter junction through a resistor Rb (the picture in the attachment below); then we can consider the BJT as a current-controlled device. We may look at this arrangement from two viewpoints. First, we can think of the combination "Vin + Rb" as a simple current source that is shorted by the transistor input (the base-emitter junction acts as a current load). Second, we can think of the combination "Rb + base-emitter junction" as a transistor with a large voltage range (a voltage load).; as though the transistor has enlarged many times its input voltage range and it has transmuted into a kind of FET-:) The increased linearity will be an additional advantage...

    This is an old V-to-I technique widely used in the measurement in the past - imagine an old-fashioned analog voltmeter built by an ammeter (a movement) and a resistor connected in series. Like in the case of the BJT above, we can control a real ammeter by a small voltage (a few hundred mV). The only difference will be the linearity...

    But yet, what does "voltage controlled" and "current controlled" mean? Is this a property of the input source or of the very BJT?
    Lutz von Wangenheim · Hochschule Bremen

    Gentlemen - for my opinion, this discussion didn`t come to a - more or less - common conclusion. So - I am not very satisfied.

    In another technical forum I recently had a similar discussion - and from this I have learned that most of the disagreements can be solved based not on explanations of physical effects (carrier physics internally to the BJT) but simply by test&measurements.

    Therefore, in the following I ask you two questions - and I kindly ask all forum members which belong to the "current-control" party to give an answer:  

    1.) From feedback theory we know that the signal input resistance goes up if the feedback signal is a voltage (and goes down for current feedback). Now - because an emitter resistor Re increases the signal input resistance (nobody can deny this), can we concluse that the controlling quantity must be a voltage?

    2.) The explanation for the Early effect is based on the narrowing of the depletion area (and the corresponding increase of the electrical field inside this area).  Therefore, the current Ic increases - for a constant current Ib!    Does this phenomenon proof that the current Ic depends on the voltage  which determines the field strength within the pn junction?

    Can somebody explain the Early effect (Ic increase for Vce increase ) as a result of Ib (which was held constant).

    _______________________

    I am very interested in some answers from RG memebers who are "current-control" believer.

    Lutz vW

  • Samares Kar asked a question in Static Electricity:
    Can static electric and magnetic fields from high voltage direct current power transmission lines cause harm to human and other living beings?

    High voltage power transmission lines create strong electric and magnetic fields. High voltage direct current lines have lower losses and are believed to be less harmful to health than the alternating current lines. Still, can the strong electric and magnetic fields interfere with our system, e.g. cause polarisation and harmful dipoles and/or interact with the internal magnetic fields?

  • Is there any software by which we could attach two domains via a 24 AA in Gly rich linker?

    I am looking for an approach and or tool/software by which I could link one protein domain to another protein domain via linker (24AA and Gly rich linker)?

    Thank you

    Jonathan Elegheert · University of Oxford

    Hi Navaneet, sounds like a good plan. In principle, Coot can handle making and renumbering the loop as well (under the "calculate" and "Extensions" menus) ...

    All the best, Jonathan

  • Richard L. Meehan added an answer in Construction:
    Is construction considered a lesser academic endeavor? And why?

    Look at societies overall perception of the construction industry.

    Richard L. Meehan · Stanford University

    Why shouldn't it be considered a lesser academic activity? It is not an academic entity in the first place. The more academic you would like to make it, the less effective you will be at it. If you want to succeed at it in some way aside from being a bureaucrat, you should forget about academics and go do it. Do you imagine that academic accomplishment is important? Then you don't belong in the construction business except as an employee.

  • Xqg 911 added an answer in Cell Line:
    Does anyone have thyroid cellline?

    Hello everyone, 

    we are working in thyroid cancer, and currently using K1 and Nthy, does anyone working in other thyroid cell lines?

    Xqg 911 · Jilin University

    How can I contact you?

  • Are wound swabs from open fractures for bacterial cultures practical?

    Hi everybody. What has been your experience regarding obtaining swab cultures from traumatic wounds done initially in the emergency dept? are they worth it?

    Abdolmajid Ghasemian · Tarbiat Modares University

    The respective comments of previous scientific responses are correct. when sampling from wound it is necessary to work completely in sterile condition. also any microorganism that is isolated from sterile body sites should be seemed as pathogen.

  • Has there been research to showing that increasing education improves ethics in a community?

    'Students often know the right thing to do. How can schools help them to do it?

    The numbers are in and they don't look good." That was the assessment of the Josephson Institute of Ethics last October, when they conducted a survey about the moral standards of more than 20,000 middle and high school students. Almost half the young people reported stealing something from a store in the previous 12 months. In the same period, seven out of 10 cheated on an exam.
    Should we be worried? Many observers say that we should. We see evidence of more antisocial behavior than ever among our youth—a sort of divorce between personal ethics and everyday behavior.'

    Has there been research to show that with increasing education, there has been improved ethics in a community?  Can you share, give some evidence? Thanks.

    Atena Eslami · Lorestan University

    Hi

    I think these two papers are useful to answer this question:

    http://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=3&cad=rja&uact=8&ved=0CC0QFjAC&url=http%3A%2F%2Funesdoc.unesco.org%2Fimages%2F0014%2F001490%2F149079e.pdf&ei=BiCcVNL8KYTkUomjgZAL&usg=AFQjCNEDesTQ04JAicy4emNFi3RXixGHXw&sig2=ir3rjP-yayjo4234MQpZng&bvm=bv.82001339,d.d24

    http://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=10&cad=rja&uact=8&ved=0CFsQFjAJ&url=http%3A%2F%2Fwww.emro.who.int%2Fdsaf%2FEMRPUB_2012_EN_1362.pdf&ei=BiCcVNL8KYTkUomjgZAL&usg=AFQjCNGm85ZhHWzO77AdBT1pJxTXf5EuzQ&sig2=sr6u_LIiSYoUwp6KtRv36Q&bvm=bv.82001339,d.d24

  • What are the health benefits of Guava?

    Some excerpts from the article "Go guavas – 10 reasons to eat this fruit!" by Sameer:

    "Guavas or amrood is blessed with many nutrients by nature. Originally found in South America, this fruit was presumably brought to India by the Portuguese. Here are some of its health benefits:

    Improves your immunity

    Guavas contain four times the Vitamin C content present in oranges. Vitamin C helps in improving your immunity and thus keeps your body healthy and protects it from pathogens that cause infections. (Read: Immunity-boosting foods that are available in India and easy on the pocket!)

    Improves your hormonal function

    Copper, present in guava, helps in the production and absorption of hormones. This property helps in improving the function of your endocrine system especially thyroid glands which is responsible for the way in which you metabolize food, use energy, etc.

    Lowers risk of cancer

    Being diagnosed with cancer can be a person’s worst nightmare. Being rich in Vitamin C and antioxidants like lycopene, eating guavas can protect your cells from damage and reduce your chances of getting cancer. Additionally, Vitamin C boosts your immunity which is critical in fighting cancer cells. (Read: Top 10 food habits to prevent cancer)

    Good for diabetics

    Rich in fibre and with a low glycaemic index, guavas can be consumed by diabetics and those who want to prevent diabetes. When you have diabetes, your body stops producing insulin which is responsible for the absorption of glucose. Consuming fruits and vegetables rich in fibre is recommended.

    Has anti-ageing properties for your skin

    Guavas are rich in Vitamin C, Vitamin A and antioxidants like lycopene and carotene which protect your skin from wrinkles and fine lines, thus making you look younger. Old-age is a certainty in everyone’s life, and eating a guava every day can at least prolong the process.

    Helps treat constipation

    Constipation is caused when food is stuck in our colon. Guava, is rich in fibre which helps in clearing the blocked pathway and thus curing your constipation. (Read: Top 10 home remedies for constipation)

    Helps improve vision

    Even though, guavas are not as rich in Vitamin A as carrots, they still are still a very good source of the nutrient. Vitamin A helps keep your eyes in good condition, and also helps improve your vision. Night blindness is one of the diseases associated with a Vitamin A deficiency.

    Good for pregnant mothers

    Guavas contain Folic acid, or Vitamin B-9, which is recommended for pregnant mothers since it can help in developing the baby’s nervous system and protect the newborn from neurological disorders.

    Helps you relax

    Magnesium present in guavas helps in relaxing your nerves and muscles. In today’s stressful times, consuming a guava to combat stress and relax is certainly a good idea. (Read: Feeling stressed? Try these natural remedies)

    Good for your brain

    Brain is one of the major organs of our body, and keeping it healthy should be on our priority list regardless of how intelligent we consider ourselves. Guavas contain Vitamin B3 and Vitamin B6, also known as niacin and pyridoxine, which helps in improving blood circulation to the brain and relaxing your nerves."

    Your views are welcome! - Sundar

    Sundarapandian Vaidyanathan · Vel Tech - Technical University

    See this link also for knowing more on the health benefits of Guava:

    Some excerpts below:

    "The health benefits of guava include the treatment of diarrhea, dysentery, constipation, cough, cold, skin care, high blood pressure, weight loss and scurvy.

    Many of you may have tasted this mouth-watering treat, or have at least seen or heard about it. Guava is very common in Asian countries, but is increasingly available in the western world, particularly as more of its health benefits are revealed. It is a somewhat round or pear-shaped seasonal fruit, and is light green, yellow, or maroon in color on the outside when it is ripe. Guava also has white or maroon flesh and lots of small hard seeds enveloped in very soft, sweet pulp. It is eaten raw (ripe or semi-ripe) or in the form of jams and jellies.

    This popular fruit is a powerhouse of nutrients. If the traditional adage says that “An apple a day keeps the doctor away” in Europe and Americas, the phrase is probably changed to “A few guavas in the season keeps the doctor away for the whole year” in the Indian Subcontinent and places where guavas typically grow. Its scientific name is Psidium Guajava.

    What makes guava special is that protecting the fruit does not require excessive use of chemical pesticides as in the case of grapes, apple, and other so-called “exotic” fruits. It is one of the least chemically treated and sprayed fruits."

  • Amr Abdulfattah Hassan added an answer in Ontology:
    I want to apply clustering on extracted key concepts for ontology learning. Can anyone help me in this regard?

    I have a domain ontology and I want to enrich it. I have extracted many concepts but these are too many. So I want to apply some clustering according to base ontology classes. Anyone can give me any idea in this regard?

    Amr Abdulfattah Hassan · Karl-Franzens-Universität Graz

    if you can change you data into numbers I suggest to use neural networks with self organizing map

  • Arturo Geigel added an answer in Learning:
    Do you agree with Daphene Koller's view on what we are learning through on-line education?

    On line education is the in thing and is going to alter the way we learn and form our world view. Do you agree with this. Here is an interesting view put forth by Daphene Koller.

    Arturo Geigel · Polytechnic University of Puerto Rico

    I think that it is a step in the right direction but it is only part of the way. If you analyze the communication of ideas it can be broken down into:

    1)The ideas that the professor has

    2)How he articulates it

    3) How it is received by the student perceptually

    4) How is that perception broken down into concepts by the the student(receiver).

    The "big data" approach that Daphne uses only identifies where the communication has gone wrong, but does not identify in which step did the communication broke down. Automating this part is another story

  • Clemens Anklin added an answer in Octanes:
    How to distinguish the stereoisomers of bicyclo[3.3.0]octane, for example cis- and trans-ones?

    organic chemsitry

  • Mathan Sambu added an answer in Impedance:
    How to obtain or derive IMPEDANCE TUBE (2 microphones) method in mathematical formula term?

    I would like to know and understand more on Impedance Tube method to obtain on acoustical properties in formula term. It may very helpful to me, by proving the term in derive way. Thank you to all.

    Mathan Sambu · Universiti Tun Hussein Onn Malaysia

    Thank You Mr. Jacek Konieczny and Mr. Eric Rosenkrantz. great help for me. tq

  • Naouar Belghini added an answer in Activity Theory:
    Any theorotical approach for context modelling ?

    Dear all,

    I am doing a state of the art about context modeling. From theoretical point of view i didn't find many works related to context modeling except some works based on activity theory to model context as in http://link.springer.com/chapter/10.1007/11740674_1#page-1 and other works related also to human cognition discussed in the work of Nardi, B. A. (Ed.). (1996). Context and consciousness: activity theory and human-computer interaction. Mit Press.

    Do you know any methodological approach for context modelling ?

    Best regards,

    Ines

    Naouar Belghini · Université Sidi Mohamed Ben Abdellah

    first you should determine context parameters.

    for example if you consider time as context parameter, you can fix:

    Time_para={morning, afternoon, evening, night }

    and an easy way to represent this context , is to set to 1 or 0 the considered attributes.

    thus if you want to specify that it is "afternoon" => Time_para={0, 1, 0, 0}

  • What is meant by setpoint and integral gain in scanning probe microscopy?

    Setpoint and Integral gain seems to be vital parameters that control the scanning of the sample surface during scanning probe microscopy. How do these parameters control the final image characteristics?

    Janusz Rebis · Warsaw University of Technology

    Preparation of steel (because of corrosion) is difficult. Best results I got after electrolytic polishing or grinding sandpaper 2500. Most important thing is to measure quickly after specimen preparation. Are You sure You got flat samples w/o oxides? Another problem with AFM may be the Z scale (in Veco/Bruker/DI nanoscopes is aprox 6um). Higher differences than 6um on the sample may cause inability to study. If I understand You well, you have Hysitron nanoindenter? If so, AFM head in this device is only for 'preview' - if I remember well - in contact mode. If You got problems with obtain picture try to change gain from small to higher value. For differ materials in CM I changing gain in range 0.2 to 30 (on nanoscope). Always try to start imaging from small area - if You will be able to scan 1x1um - You will be sure SPM works ok. On the other hand, maybe using AFM (not spm head from Hysitron) in PhaseImaging, ForceModulation or MFM could show You differences of phases?

  • Pınar Sancak added an answer in Carbon Nanotubes:
    Can anyone help me the solubility of PAMAM modified multiwalled carbonnanotubes?

    Hi everyone,

    I try to carry GFP trough to HEK cells by using PAMAM modified carbonnanotubes..

    My problem is the aggregation of carbonnanotubes on HEK cells. When i get a complex with GFP/carbonnanotubes and i applied on cells, Carbon nanotubes aggregate on cells so is there any advice for this situation?? And the note that i used sonication during 30min and there was no any positive results..

    What should i do? 

    Pınar Sancak · Fatih University

    Thank you very much for all the answers.

    As all said, I should give more information about my experiments. Okey, first i said that I used PAMAM-modified multi walled carbon nanotubes for GFP delivery but i have no any positive results.
    My experiment steps are:
    1) Synthesis of MWCNT-PAMAM
    2) Solubility of MWCNT-PAMAM
    3) Preperation of MWCNT-PAMAM/GFP complex
    4) Transfection HEK cells with MWCNT-PAMAM/GFP

    For Synthesis of MWCNT-PAMAM,
    After amine functional carbon nanotubes (outer diameter: 13-18nm, length 3-30μm) is dispersed in methyl alcohol, methyl acrylate dissolved in methyl alcohol with the same way and it is slowly added with stirring and it is kept stirring for 3 days at 400C. Then the excess methyl acrylate and methanol are decanted from the reaction medium and washed 5 times with methanol by decantation. The resulting ester functional carbon nanotubes are dispersed in methyl alcohol and ethylenediamine solution again dissolved in methyl alcohol is added slowly into the carbon nano tube solution. After stirring the mixture for 4 days at 400C, excess ethylenediamine and methyl alcohol are decanted and washed 5 times with methanol by decantation. Amine functional generation 1 (G-1) dendrimer was obtained on the carbon nanotubes. Next generations (G2, G-3, G-4 and G-5) were synthesized by repeating these steps. Amine functional carbon nanotubes were activated using EDC and NHS.
    Note: MWCNTs were purchased and modification and being more generation processes just were carried out by our chemical research group.

    For solubility of MWCNT-PAMAM, I used different solvents such as distiled water, PBS, DMEM and Ethanol which are biocompatible molecules except ethanol that shows differances at applied dose. While the solubility level of MWCNT-PAMAM is almost same in PBS, DMEM and distiled water, it shows more solubility in ethanol. However, MWCNT-PAMAM in ethanol is more cytotoxic for HEK cells. I mean, I overcome the solubility problem when i used MWCNT-PAMAM with ethanol but at this time cells die due to ethanol effect. After i got this results, i changed experimental protocole. After dissolving of MWCNT-PAMAM in PBS, DMEM and distiled water, i used ultrasonic bath for 30 minutes and then ultrasonic probe for 5 minutes. In spite of this processes, the results didn’t change. And although my advisor or other chemistry scientists said me that after using sonication methods it will be more easier for me, it doesn’t work.

    For the preperation of MWCNT-PAMAM/GFP complex, i use different molar ratio of MWCNT-PAMAM and GFP. In order to analyse the interaction of MWCNT-PAMAM with GFP, i carry out agarose gel electrophoresis. And then the concentration that allows for interaction of MWCNT-PAMAM with GFP is used for transfection on HEK cells.

  • Vasily Osipov added an answer in Rough Set Theory:
    Whats the difference between feature selection in machine learning and feature reduction in information systems?

    I'm working on feature selection methods. I found feature reduction in rough sets theory a concept similar to feature selection in machine learning and data processing tasks. However it seems that they have some principal differences. Can anybody explain if I can use them in place of each other?

    Vasily Osipov · Russian Academy of Sciences

    There is no clear boundary. In all cases, we are able to use the same methods. However, when it comes to the application of neural networks and traditional methods, the difference is obvious. In the first case, due to training, we associate the elements of the signals, their characteristics and other features. Then, we use them for recognition and selection. Using traditional methods, we are hard-coded rules. As regards the theory of sets in the space of breeding, including the use of neural networks, see the article " Cover T. M. Geometrical and Statistical Properties of Systems of Linear Inequalities with Applications in Pattern recognition // IEEE Transactions on Electronic Computers, June, 1965".

  • How can I estimate the calories from food images (new method)?

    Thanks in advance

    Sundaram Muniasamy · Kamaraj College of Engineering and Technology

    it is not possible I think so

  • Shahinaz Mahmood Shams added an answer in cDNA:
    How should i design the 96 well plate of qPCR for 2 samples and i have 5 different apoptosis genes?

    I have two cDNA samples

    i need to compare the expression of 5 different genes ?

    How should i do this?

    Shahinaz Mahmood Shams · Georgia Regents University

    Thanks so much Celestina for your answer

    we hav in the lab. both syber green and taq-man probes

    it will be great if you send me your en house protocol

    i will use GAPDH as the house keeping gene

    but the reference sample, you mean the negative control without any therapy?

    i did not extract RNA from a negative control cell line, i only extracted from the comparison arms only !!

    but you are right i should have a reference sample

  • How to design DC side capacitor?

    I need to design capacitor for shunt active power filter for the inverter?

     What parameters do I need to consider?

    Navdeep Singh · Motilal Nehru National Institute of Technology

    Normally, ripple current is controlled by inductor value which is directly connected after the inverter and also switching frequency of the system.

    If we use a higher value of capacitor, it affected the dc link voltage also . 

    CB2B = Iin,rms/(4√2·VDC·VDC· fsw1)

    VDC is the relative peak to peak DC-link ripple (limited to 1%), VDC is the DC-Link voltage, Iin is the current ripple.The DC voltage itself is designed taking a 10% safety margin on the rated voltage (VDC = 1.1√2VLL).

    MAY be it is sufficient for your question 

  • Robert Tomsik added an answer in Likert Scale:
    How to do data analysis for likert scale?

    I have prepared a questionnaire which contains Likert scale.Respondents are in four different age groups and there are 20 questions asked using likert scale. Can i use 1 way ANOVA?

    Robert Tomsik · University of Constantinus the Philosopher in Nitra - Univerzita Konstant’na Filozofa v Nitre

    Dear Yogesh Raut,

    the answer is yes you can. You can compare those groups in mean of all scale, subscales or specific question.

    Good luck!

  • Pamela Shiao added an answer in Hazard Ratio:
    Can hazard ratios and odds ratio be used interchangeably in meta-analysis? If not how can I convert hazard ratio to odds ratio?

    For meta-analysis: Can hazard ratios and odds ratio be used interchangeably in meta-analysis? If not how can I convert hazard ratio to odds ratio?

    Pamela Shiao · Azusa Pacific University

    Another 2008 reference by Ian Scott addressed this issue, specifically in pages 14-15. Scott, I. Interpreting risks and ratios in therapy trails Australian Prescriber, 2008;31:12-16. http://www.australianprescriber.com/magazine/31/1/12/6

  • Ishag Adam added an answer in Antimalarial Drug:
    In reference to antimalarial drugs what is the difference between Gametocidal and Gametocytocidal ?

    Q.In reference to antimalarial drug what is difference b/w Gametocidal and Gametocytocidal ??

    Ishag Adam · University of Khartoum

    I do  not feel  that  we have to  go  deep  differentiating gametocyte and a gamete

  • How parse trees database can be stored as relational database?

    I want to know how parse trees are stored in relational databases and how a query in parse tree query language can be generated automatically in the presence and absence of training data.

  • Tom Koch added an answer in Ecosystems:
    What do standard ecological models predict will happen if humans were suddenly to go extinct?

    In light of recent concerns around climate change and the health of global ecosystems, I've been wondering:

    Is the net effect of humans on the global ecosystem positive or negative?

    How would major ecosystems fare if we disappeared? Which systems would fail? Which would flourish? How would nature adjust? Could it adjust?

    Would be good to know the more subtle, less obvious effects we're having and how they would change the planet as well.

    Tom Koch · University of British Columbia - Vancouver

    These are really two different questions: Wht is the effect of humans on the evolving global ecological system and what would be the effect if humans were to be exstnguished. The first answer is ... profound. As a dominant species we are an integral part of the global ecosystem. Our programs of deforestation, hunting, pollution, etc. have been a critical factor in its accomodating changes. The ecosystem at present is one that reflects our tenure on the land and, over the last century, our ill-use of it. The result is climate change, species extinction, etc.

     It is unlikely humans will disappear from the earth. It is very possible that the changes resulting from our industrial tenure will result in a catastrophic reduction in human population. This will be from economic collapse, climatic changes, new diseases, etc. So that would reduced our place in the world as a species and, depending on the nature of the catastrophic trigger, our continuing effect on the ecologies of the world. Anything more specific would be just speculation.

    But it's also fairly clear from a series of studies that were we to cease to be, or cease to be as industrial beings, that the world would reclaim it's own. Buildings would crumble in the process that promotes fundal, bacterial, and plant habitation of our built materials. Air quality would change (after 9/11 we saw an example of this when jets were grounded and the air became clearer), water quality would change, etc.

  • Arijit Basuray added an answer in Capacitance:
    How can I determine the values of capacitances Ca, Cb and Cc of voids present in the dielectrics?

    Ca is the capacitance of healthy insulation

    Cb is the capacitance in series with the void

    Cc is the capacitance of void.

    I don't know about the size of the void. How can I calculate the above mentioned capacitances?

    Arijit Basuray · Jadavpur University

    Normally the dimensions of voids are microscopic compared to bulk insulation and concentration is also very low. Though the capacitance of void is different from the surrounding media it hardly affect the global capacitance of the bulk insulation. So we can use Ca, Cb etc to build a model to explain PD but  individual  Capacitance values can not be detected by direct measurement. However dimensions and concentration of voids may be detected by X ray or infrared thermography.

  • Martin Denbar added an answer in Sleep Apnea:
    What is the role of a sleep study in pediatric population when there is disturbed sleep with Apneic spells due to obstructive upper airway disease?

    Sleep study is mandatory for adult patients with sleep apnea. Is it the same for pediatric patient with sleep apnea?

    Martin Denbar · Texas A&M University System Health Science Center

    I agree with what you are saying, but the studies are showing that tongue level associated with mouth breathing and snoring are also implicated in Sleep Disordered Breathing (SDB).  Also, if the tongue situation is not corrected there is more of a chance post pubertal for  SDB to return.  Of course if the population is more inclined to breast feeding then the natural development of a proper tongue placement, palatal height, occlusion, side plumb line, swallowing pattern and posterior airway space will be developed.  Since many countries are not experiencing normal breast feeding but rather bottle feeding, you will probably have more of an issue in non-breast fed populations.  This is where the field of Myofunctional Therapy enters into the picture.

  • Julia Shaparenko added an answer in Minority Groups:
    What is the best theory to use in researching entrepreneurial success among ethnic minority entrepreneurs?

    The research is looking at alternatives measures of success among ethnic minority groups. Apart from the attribution theory, what other theory(ies) best explain the construct of success?

  • Why can't we run proteins on horizontal gel electrophoresis and DNA and plasmid samples on vertical gel electrophoresis?

    Why can't we run proteins on horizontal gel electrophoresis and DNA and plasmid samples on vertical gel electrophoresis?

  • Where is the best place to place a radiation measument lab, 4th floor or basemnet?

    You want to establish a radiation measurement lab.  You also have the option of choosing either the basement or a top floor (say 4th floor).  The lab is supposed to be capable of measuring all types of environmental radiations.  What would be the best option?

    Hanno Krieger · retired from Justus-Liebig-Universität Gießen

    This will depend on the kind of radiation you will measure. Give you an example, look at the radon distribution within a house. Or try to measure environmental gammas down in the base floor with all the screening effects. Please give some more details!

  • B.A. Padder added an answer in Mycobacteria:
    Does anyone have knowledge of the efficacity of TaKaRa Ex Taq Hot-Start Version kit in large spectre PCR for diagnosis?

    I'm trying to optimize a polymerase chain reaction for detection of eubacterias, mycobacterias, among other things. I'm trying several different kits and I wanted to know the pros/contras of this one.

    I will also try FastStart PCR Master from roche and an another one from Applied biosystems.

    Thank you

    B.A. Padder · Sher-e-Kashmir University of Agricultural Sciences and Technology

    Better to go with applied biosystems than takara