• Safia Belhadj added an answer:
    How can we observe Juniperus phoenicea stomata?
    It is difficult to use standard imprints method.

    Can anybody help? Thank you.
    Safia Belhadj · Ziane Achour University of Djelfa

    thank you for your answer Massakib Bekkaye.

  • Margaret Moss added an answer:
    Why isn’t nutrition a bigger part of conventional medical school education?
    Diet is arguably the single most important preventive measure for healthy aging because it affects the functioning of every organ in the body and is a factor both in the development of disease and in recovery.
    Margaret Moss · Nutrition and Allergy Clinic

    I use tests of enzyme activity for vitamins B1, 2 and 6. For B1, the activity of erythrocyte transketolase is measured before and after the addition of excess vitamin. For B2, erythrocyte glutathione reductase is used. For B6, erythrocyte glutamic-oxaloacetic transaminase is used.

    Without a lab, issues brought by the patient can often be resolved. A complaint of sore eyes may be resolved with vitamin B2, molybdenum, or both. Frequent viral infections may be avoided with vitamins C, D and zinc. Energy levels may be improved with B vitamins, magnesium and ubiquinol. Anxiety and insomnia may be resolved with magnesium and inositol. If the patient improves with supplementation, and deteriorates on stopping the supplements, it seems reasonable to conclude there is a deficiency.

  • Jasmer Singh added an answer:
    Is hair analysis of minerals and trace elements reliable?
    Especially in alternative medicine, hair analysis often used to detect deficits and surpluses of minerals and trace elements. Are these tests reliable? What are the minerals and trace elements suitable for element analysis in hair, and what are not suitable?
    Jasmer Singh · Guru Angad Dev Veterinary and Animal Sciences University

    Hi  Hair mineral analyses is not a new technique but from time immemorial days , of course, whatever methods were available -qualitative etc., have been in use. However, with progress in technological innovations "Hair mineral analysis"  has made its mark as most dependable, precise and well recognized technique in clinical investigations. However, the interpretation of its analytical results needs thorough basic knowledge of interactions of minerals and the proteins e.g., enzyme catalysts, and their imbalances in molecular reactions in relation to disease.

    Jasmer Singh 

  • Edward Siguel added an answer:
    Does the human body have a mechanism for storing EFAs or EAAs ?

    Can the human body distinguish essential and non-essential fatty acids or amino acids, or does it simply indiscriminately burn what it finds in the bloodstream depending on the body's needs at the moment?

    Edward Siguel

    There are two main "storage" systems for EFAs and their derivatives. I coined the term essential fats = EFA + DEFA (FA derivatives from EFAs).

    Membranes have essential fats for their function; they are not there for storage in the sense that we use storage as a place where we keep surplus when we need them.

    However, if there is a deficiency, the body recycles things. Will do it for amino acids and likely for essential fats.

    Adipose tissue is the storage form for FA. The main FAs in fat storage are the EFAs, not the DEFA, and saturated FA. Notice that humans do not store extra EPA, DHA, ARA. Instead, they store ALA and LA.

  • Michael Nordine added an answer:
    Using NIRS underwater?

    Has anyone any experience/advice for measuring central/distal hemoglobin via NIRS (NIRO-200, Hamamatsu Photonics) during water immersion? Will the electrodes function underwater? Will immersion destroy the electrodes? Before I test this out, and potentially make a very expensive mistake, just wondering if anyone has tried this before.


    Michael Nordine · Charité Universitätsmedizin Berlin

    Hey David, thanks for the article recomendation. After reading it, it appears that using something like the Iswim (a waterproof seal for smart phones) may work to our advantage, with a few modifications.

  • Prasanna Waichal added an answer:
    Control Biopac's Stimulator (STM100C) through SuperLab?

    Dear all,

    I'm using Biopac's STM100C as a stimulator connected to a computer with AcqKnowledge through MP150 and another computer with SuperLab sending outputs to this system through StimTracker. I've been trying to control STM100C from SperLab's Digital Output without success.

    So far, I tried to trigger AcqKnowledge's Digital Channel 15 as the STP100C responds to changes (0 or 1) in this channel when its "source" knob is set to "pulse". I managed to control changes in AcqKnowledge's Digital Channels 8 to 10 sending sending Digital Outputs from SuperLab, but not AcqKnowledge's Digital Channels 15.

    Would anyone happens to have a clue on how to control AcqKnowledge's Digital Channel 15 through SuperLab and/or any other way to trigger Biopac's STM100C through SuperLab?



    Prasanna Waichal · Fiji National University

    This video link to Youtube from Biopac might be of your help.

    Sorry for late response, a bit busy! I have sent to my video to your mail ID.

    Keep in touch!

  • Siamak Gholamalipour added an answer:
    what kind of adenosine receptor (A2A , A1) is activated in responding to the secretion of ATP by astrocyte?
    ATP released from astrocytes is degraded to adenosine and activates presynaptic adenosine A2 or A1 receptors that leads to an increase or decrease in its release probability (Panatier et al. , 2011). Now the problem is:
    After secretion of ATP by astrocyte:
    Which mechanism is activated A2A receptor on presynaptic neuron?
    Which mechanism is activated A1 receptor on presynaptic neuron?
    Which mechanism determines that what kind of adenosine receptors on the presynaptic neuron (A2A , A1) should be activated in response to astrocyte adenosine secretion?
    Siamak Gholamalipour · Urmia University

    Hi Hossein 

    please check this article 

    I hope it's helpful .

  • Domingos Pandelo added an answer:
    Is individual soccer training more effective than training in a group? Are there any research studies which prove that?

    For my bachelor thesis about "individual soccer training" I need studies which prove that individual trainings for physiological, technical, psychological and tactical aspects of soccer are more effective than working in the whole team.

    Thank you for your help

    Domingos Pandelo · Fundação Getulio Vargas

    Hi Robin, maybe this links can help u with some insights :)

    Hope it helps. I am from quantitative research area, so i love math and statistics, and sport science,  :)

  • Edward Narayan added an answer:
    Would irradiating faecal samples before extracting glucocorticoid hormones affect the results of the EIA?
    For safety reasons (to kill potentially infective micro-organisms) I would like to irradiate faecal samples (from various mammalian species) before performing enzyme immunoassays for faecal glucocorticoid metabolites. I use freeze-drying, followed by a chemical extraction method (using 80% methanol) to extract the GC hormones from the faeces. I would like to do the irradiation before the freeze-drying step. I am currently using both cortisol and corticosterone EIAs on the extracts. Is the irradiation likely to affect the EIA results?
  • Danny J Gustafson added an answer:
    Is there a non-parametric equivalent of a 2-way ANOVA?
    I have two groups, drug treated vs control, and obtained tissue and made measurements at 5 different time points. A 2-way ANOVA works for some of the variables which are normally distributed, however I'm not sure what test to use for the non-normally distributed ones. Samples size varies but ranges from 7-15 per group at each time point.
    Danny J Gustafson · The Citadel

    Thank you for the very helpful question and replies. I am also happy to see the specific chapter and page reference to Sokal and Rohlf -biometry (my STATs bible from grad school). 

  • Valbona Aliko added an answer:
    Is there any virus which can infect the RBC ?
    RBC doesn't have a nucleus so is there any exception virus which can affect the RBC?
    Valbona Aliko · University of Tirana

    Fish, amphibians, reptilians and birds possess nucleated erythrocytes. So of course, in these cases a virus infection can exists. In mammalian, during erythropoyesis erythrocyte possess nucleus than it looses it.Maybe if virus infect the precursors of  red blood cells!!!???

  • Valbona Aliko added an answer:
    Which one is more preferable for blood collection from wistar albino rats by retro orbital or by jugular vein?
    Actually, I want to know which method should be used to collect blood from rats because the jugular vein has to be exposed to collect blood which make rat experience a small trauma and additionally there may be a chance of getting infection on that exposed site.
    Alternatively retro orbital is very very painful for rats.
    Valbona Aliko · University of Tirana

    I will suggest tail vein. Just keep it warm for a little bit (by hand or in warm water). You can use this route for small amounts of blood.

    Good luck!

  • Valbona Aliko added an answer:
    Can feces can have traces of hormones, which can give clues about oestrus?
    At least in the case of higher mammals
    Valbona Aliko · University of Tirana

    It is possible to find steroids in feces. here below you can find a very interesting article on the subject. I hope you can find it useful.

    Reproductive Biology and Endocrinology 2013, 11:83 doi:10.1186/1477-7827-11-83

    "Fecal estrogen, progestagen and glucocorticoid metabolites during the estrous cycle and pregnancy in the giant anteater (Myrmecophaga tridactyla): evidence for delayed implantation"
    Katrina K Knott1*, Beth M Roberts1, Morgan A Maly1, Carrie K Vance12, Jennifer DeBeachaump1, Jackie Majors1, Peter Riger34, Heather DeCaluwe3 and Andrew J Kouba1

  • Valbona Aliko added an answer:
    Is there a method (Not the Anthrone reagent) to determine of glycogen in both liver and muscles?

    I need to determine the glycogen in both liver and cardiac muscle, so I need another method to do different from the Anthrone reagent.

    Valbona Aliko · University of Tirana

    We had used successfully the amyloglucosidase method in measuring glycogen content in frog liver and sceletical muscle.

  • Ricardo Matias added an answer:
    Do you know a wearable device (wrist or arm) to measure physiological response (ECG and EDA)?

    I am searching for a device to measure ECG and EDA. Ideally the device should be worn on the wrist or the arm. I prefer not to use chest band or similar. 



    Ricardo Matias · Instituto Politécnico de Setúbal

    Hi Davide,

    Any of these DIY platforms will help you for sure:

    - BITalino
    - Libelium e-Health Sensor Platform
    - OpenEEG

    I hope it helps pushing your project.

  • Xiaogang Feng added an answer:
    What is the total cell number of a C57 mice Popliteal lymph node ?

    Hi , I need to know the total cell number of a C57 mice popliteal lymph node.

    Xiaogang Feng · Karolinska Institutet

    depends on my eperience, it could be around 350000, which is counted from alive cell from 4 weeks old mice without any infection! Good luck!

  • Ricardo Matias added an answer:
    Do you have any knowledge on real time human performance monitoring?

    I am looking for any devices (especially telemetric) that are capable of monitoring real time the human performance (e.g. during running, or roller skating). Any device counts which suitablly monitors pulse, speed, blood lactate, blood pressure etc. For example Team Polar or Polar RC3GPS. Preferably the devices with the more types of data would be better.


    Ricardo Matias · Instituto Politécnico de Setúbal

    Hi Béres,

    In a more low-cost perspective I would say:

    - You could simply develop a Do it Yourself project;
    - Or thinking more outside the box I would say give it a try with some mobile sensing (to some parameters) using today's smartphone technology.

    For both cases I am pointing some hardware and software links that I hope can still help you:

  • Abhijit Naskar added an answer:
    What are the physiological mechanisms involved in cognitive impairment?

    What are the physiological mechanisms involved in cognitive impairment?

    Abhijit Naskar

    My new book The Art of Neuroscience in Everything explores the arena of the physiology behind cognitive characteristics of the brain. Grab your copy and embark on a journey of scientific revelation through the mysterious human experiences, behaviors, feelings and instincts. like faith. love, religion, lust, attraction, sex, kindness, empathy, good and evil.

    Best Wishes
    A. Naskar

  • Lee Purdioux added an answer:
    Have the physiological responses to humor been studied?

    Are there distinct or unique physiological responses to humorous stimuli? Of special interest is political humor such as in editorial/political cartoons. Such political humor also has been posited as generating anger responses so a second question would be if there are differences in humor and anger responses that can clearly identify the source of the humor/anger response.

    Lee Purdioux · Capella University

    Hi Edward,

    Many researchers tried to measure the affective nature of humor setting smiling and laughter as objective indicators; however, coefficients rarely exceeded between .30 and .40.  When this research was re-evaluated using FACS, they found correlations to be .65 and above, indicating that the early research on humor did not separate different types of smiles.  You might want to look at Ekman’s work on FACS, or Ruch’s work on laughter.


  • Federico Bellavere added an answer:
    How do you report and interpret the frequency-domain analysis of HRV? Do you report both total power and normalized unit?

    I am looking for a suitable approach for reporting HRV parameters extracted in the frequency domain (VLF, LF, and HF) and their interpretation:

    - Do you report both power in LF and HF bands and normalized unit values for LF and HF bands?

    - For physiological interpretation, do you use total power or normalized unit?

    Federico Bellavere · APSS Trento

    First: if you have not the respiratory signal you should consider that in case of youg people ( athetes..) the respiratory frequency can almost shift in the LF band (below 0.12 Hz) and your analisis could be seriously affected by a methodological error. It is very simple to have a respirtory frequecy control as most of thelemetries give it . You can use also a "strain gaudge"  loop (which cost more and gives less...") . In case you have already preformed a study without the respratory signal, you can interpret the LF/HF ratio of normalised units during standing when respiatrory frequncy is "usually"  higher than 0.12 Hz  also in Young people, just to have a measure of sympathovagal balance, but this in not a very appropriate measurement....

  • Sean Tomlinson added an answer:
    How do I calculate total body water content using deuterium dilution technique?

    Currently I am using the formula by Tam et al 2011., 

    TBW = [((T x A/a) x ((Ea – Et)/(Es-Ep)))/1000]/1.04,
    where A is the amount of dose solution drunk (g); a, amount of dose solution diluted in T (g); T, amount of water in which ‘‘a’’ was diluted in (g); Ea, enrichment of diluted dose; Et, enrichment of water used to dilute the dose; Ep, enrichment of baseline sample; Es, enrichment of postdose sample; 1.04, correction factor for overestimation of TBW by the use of D2O. 

    As the doubly labelled water solution that I've used came in a pre-mixed drinkable solution, I'm unsure about the values to substitute for 'T' as well as 'a'. 

    Sean Tomlinson · University of Western Australia

    Yeah, I agree with Prof Cruz-neto and White, just reach for the Bible:

    Speakman, J. R. (1997). Doubly labelled water: theory and practice. London: Chapman & Hall.

    It's a tough read, but it will have all the equations and permutations that you need.

    I also found that Nagy and Costa was a good entry point to the Speakman (1997) book. Speakman can be a bit dense, but Nagy and Costa's work is a little more intuitive for a first read:

    Nagy, K. A. and Costa, D. P. (1980). Water flux in animals: analysis of potential errors in the tritiated water method. American Journal of Physiology Regulatory Integrative Comparative Physiology 238, R454-R465.

    Hope this helps, although it sounds like you might be onto it annyway

  • Stefan De Smet added an answer:
    How does hypoxic training (live low - train high) improve anaerobic performance?

    I would like to know anything about mechanism of hypoxic training especially 'live low - train high' method on anaerobic performance improvement. How about pathway of this mechanism?

    Stefan De Smet · KU Leuven

    Small correction previous post: EPO is mainly a HIF-2 target and not HIF-1 target of course...

  • Paul Bresser added an answer:
    How is exercise capacity affected in interstitial lung disease?
    Cardiopulmonary exercise testing, field testing, VO2, oxygen desaturation, mechanical limitation.
    Paul Bresser · Onze Lieve Vrouwe Gasthuis

    Last year, we have published a paper on CPET in IPF in Repirology; first author Mart van der Plas.

    Maybe this paper can answer most of your questions.

  • Michael Nordine added an answer:
    Is there an SVR maximum for humans?

    We can calculate a heart rate maximum for humans using the equation 220-years of age. However, is there a systemic vascular resistance maximum for humans in either absolute or percentage?

    Michael Nordine · Charité Universitätsmedizin Berlin

    Good point Alexandre. Based on %CO to different organ systems, one could determine the SVR for a specific organ system, this is where impedance measurements would come in handy. The total SVR is the sum or average of organ system SVR's, which would be based on the current oxygen demand of that organ system. During physical activity, SVR in the skeletal muscle decreases, due to high 02 demand, whilst gastrointestinal SVR increases, for example. The total SVR would not reflect this distribution then. In this light, I guess I would have to rephrase my question, in asking if there is an organ specific SVR maximum?

  • Bhagat Singh added an answer:
    Dextran, Alexa Fluor retrograde labelling timecourse
    I have used dextran Alexa 488 3,000 MW from Life Technologies/Molecular Probes for tracing nerve fibres innervating the paws of mice and found that 3 days post-injection into the foot pad is usually long enough to identify labelled cells in dorsal root ganglion neurone cultures.

    Does anyone have any advice on how stable such a labelling process would be over time? For example, if I inject into the foot pad, and performed a dorsal root ganglion neurone culture 1 month later, could I expect to see approximately the same number of labelled cells as 3 days post-injection?

    I am not tied to using dextran Alexa 488, just something that has no substantial effect on cell viability and allows for easy identification of cells in culture.
    Bhagat Singh · Harvard Medical School

    Hi Ewan, What worked best for you finally? I am trying similar thing -- injection in the foot pad and isolating DRGs.....

  • Paresh Chandra Ghosh added an answer:
    Is there any possibility to differ auditory and visual reaction in different geographical region of same country ?

    I want to know is it  this reaction time can differ in population of different places.

    Paresh Chandra Ghosh ·

    Yes sir there is ethnic variation as prof Knox has mentioned. Besides ethnic difference anatomical & congenental defect will vary reaction time . It will change less in simple reaction time but significantly change in multiple choice  reaction time.Thank you pcg,CLI,chennai

  • Pierre-Alexandre Chapon added an answer:
    Can anyone recommend any core and skin temperature data loggers for use in severe heat (+150C)?

    This would be used inside large metal containers during live fire drills, underneath standard fire service equipment. We have used some methods but are interested to know if people can recommend any specific devices.

    Pierre-Alexandre Chapon · Unité Inserm U1077

    Working on thermoregulation process, I have also have identified the lack of simple solution to ensure the continuous monitoring of the core temperature during our experimentations. Given the limitations of the existing devices, I decided to create my own product (e-Celsius) for temperature measurement responding to our regular technical needs.

    The device is based on an ingestible capsule which collect and transmit the core temperature data to a dedicated monitor. The main advantage of our solution is the implementation of an internal memory in the pill (capacity  2000 data) which allow to continuously monitor core temperature without the monitor during around 15h. The data stored in the pill are automatically recovered when this one is replaced in the range of communication.

    For more information, I would ask you to visit our website and/or (version dedicated to animal monitoring). Also, I remain at your entire disposal for any complementary informations.

    Best regards

  • Marek Matejak added an answer:
    A formula to calculate Pa02 from Sp02%, anyone have any recommendations?

    I have Sp02% and Fi02%, and I want to calculate a Pa02/Fi02 quotient. Is it possible to calculate a Pa02 from Sp02%? If yes, does anyone have any reliable formulas?

    Marek Matejak · Charles University in Prague

    I can send you all five papers that I wrote here a week ago (including Severinghaus), just write me a email to marek<at>matfyz<dot>cz . 

  • Zafar Azeem added an answer:
    How to overcome overestimated MET values on International Physical Activity Questionnaire Scoring with Continuous Variable?

    International Physical Activity Questionnaire is an instrument used to assess physical activity status of population sample in age group of 20-69 years. On practical usage of the tool, the results are evaluated as MET values for domain specific MET ranges. But, when calculated for total MET values, it scores an individual on highly physical active status(min. of 3000MET min/day)

    Zafar Azeem · Charotar University of Science and Technology

    Thanks James and Joan for the answers..It has certainly helped me gain understanding the shortcomings better and would keep you updated with the developments in this regard.

  • M. Kennedy Hall added an answer:
    Which shock scores commonly used by emergency medical personnel?

    Besides the well known, shock index, are there any other commonly used clincal indices for the assessment of shock, particulalry hypovolemic/hemmorrhagic shock? If so, how are they calculated, and why are they prefered over the shock index?

    M. Kennedy Hall · Yale University

    There is some evidence that serial shock index predicts the use of vasopressors- fairly recent article so not sure if you are aware of it. 

About Physiology

Physiology is the science of the function of living systems. This includes how organisms, organ systems, organs, cells, and bio-molecules carry out the chemical or physical functions that exist in a living system.

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