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Olfaction - Science topic
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There is an abundance of new scientific literature that has been published (over the past year and a half) on new clinical research developments of electronic-nose (e-nose), or artificial olfaction and related technologies, for the early detection and diagnosis of Covid-19 coronavirus infections in human patients. This question centers around the idea of whether any of these research approaches have actually been further developed (beyond proof of concept) to the extent that new diagnostic methods (based on e-nose instruments) are already being used in clinical practice. I am not looking for literature (published research) on experimental trials, but rather actual examples of clinical uses (locations of medical facilities and technologies used) that have already been implemented in a known clinical setting or for point-of-care testing (POCT).
Retronasal flavor is sensation referral via mouth. Retronasal is not only volatile substances, but airborne containing particles, liquid drop. Retronasal substances could be recognized after swallowing.
GC-MS-O filters many interesting flavoring substances for retronasal sensation during sample preparation. Orthonasal olfaction could not reflect the performance of flavoring substances by swallowing.
It is time to invent new instrument to identify retronasal substances.
I have a student who interested in Olfactory Cognition. We want to make a comparison between the items on the VOIQ and the PSI-Q before we make a decision. I am struggling to get hold of the VOIQ or the original paper. An electronic copy of the below would be really helpful.
Gilbert, A. N., Crouch, M., & Kemp, S. E. (1998). Olfactory and visual mental imagery. Journal of Mental Imagery, 22(3-4), 137-146.
In a patient with hereditary desminopathy (Thr341Pro DES mutation in a heterozygous state) with disease progression, a significant decrease in olfaction is noted. How can this fact be explained?
What i mean is that if we are talking that the olfactory sensitivity of people is fluctuating due to different reasons (physiological state, mental state etc.), does it mean that the level of sensitivity is equal in case of all aroma compounds or it is possible that the sensitivity to some compounds /groups of compounds is lowers but to the others same time higher.
I'm looking for literature relating insect detection of entomophagous fungi (olfaction/gustation) ... Sensory physiology or behaviour
I sometimes believe that olfaction actually represents a basic form of affective processing. Has olfaction maybe always been the earliest form of an emotion system (evolutionary start of an emotion system)? Smelling things is so obviously and directly related to a "feeling" of pleasant or unpleasant, much more than it is related to "knowledge" about its origin (or semantic content).
The sense of olfaction has the most direct connections with the limbic system (e.g. amygdala) among all senses. Thus, neuroanatomy would strongly support this idea too.
Detection and recognition of smells
I am looking to purchase an olfactometer similar to the one shown in the attached picture. Any help would be greatly appreciated.
If the neurotransmitters can promote chemotaxis they may bind to receptor over cell membrane of N. fowleri to stimulate them to move cephalhead.
We have an old ATI Unicam 610 Series GC in our lab. This instrument is fitted with an olfactory port which is why I would like to "resurrect" the instrument. Unfortunately, the user manual is no longer with us.
I was hoping to connect the GC via its 9-pin "PL4 Datastation" port to a PC in order to record the basic data output, i.e. response vs. time. We do not need any form of integration as these samples have already been characterised on a GC-MS. We would simply like to be able to correlate the smell of eluting peaks with the GC-MS data.
Any suggestions on basic software that could record the output of the instrument is highly appreciated. Thanks to everyone in advance!
Olfactometers allow for the systematic administration of odorants to humans. I'm looking for something similar (preferably commercially-available and computer-controlled) for tastes/liquids. I've looked around, but so far, I haven't found anything. I'm trying to avoid making my own if possible! :-)
I am looking to build my dissertation around the use of aroma's such as lavender, lemon balm, camomile etc in products around acute mental health wards to reduce instances of agitation in psychosis and behavioural disorders.
Any information would be gratefully accepted, thank you.
The least weasel has suffered population decline in Switzerland over the past years. Due to its small body mass, presence / absence data is relativley hard to obtain. One method which has proven use full is the use of tracking tunnels.
But even if weasel presence is certain, the detectability of the species is low (i.e. the number of tracking nights needed per detection is high) . Baiting a tunnels with meat can raise the chances of detection, but at the same time attracts a high number of unwanted visitors making the tracking papers hard to impossible to interpret.
Least weasels have shown a strong preference for the odours of its selected prey, bank vole (Myodes glareolus) (link attached). Would it be possible to synthesize this odour to attract least weasels into tunnels? Can such an odour be synthesized? Another option would be to use a weasel lure used by trappers (link attached). Does anybody have experience with this? Valeria tincture does not seem to have a significant effect on least weasels, or am I wrong?
Any help is appreciated!
EDIT: Thank you very much for taking the time to share your knowledge, you've offered some very helpful advice. In response to your questions:
@ Ole: Camera trapping has proved to be very difficult due to their small body size and the speed of their movement. We definitely want to test the newest camera traps on the marked to see how they fare with the least weasel, maybe we can design and experiment where we test lures and camera traps simultaneously. A closed enclosure with captive weasels would be the best way, since we have very little knowledge of weasel presence in our area.
@ Peter: Your approach to eliminate the odour sounds very reasonable. Again, we would need some captive weasels to test this. In response to the mechanic selection with body size: The “problematic” mammals who hamper the evaluation of footprints are mostly species of the same size or smaller: Rats, Mice and snails often invade the footprint tunnels, more so if meat is placed inside the tunnel to lure the weasels.
Any troubles getting it working?
The flowmeter provided does not go over 160 ml/ min, which should be too low according to literature. Would the flow speed needed depend on the size of the olfactometer (current one - activity area diameter 30 cm)?
Do some odorants get internalized by the OSN, metabolized perhaps? Do some odorants just pop off each OR they activate and tumble into the next OR? Are there Odorant Binding Proteins shuttling odorants in reverse i.e. from OSN back into the mucous? What are typical odorant residence times on ORs?
Kite patch are promoted as repellents rendering you "virtually invisible to mosquitoes". They are based on the results of basic studies on mosquito olfaction suggesting that chemoreception can be blocked by particular chemicals. A crown-founded campaign is financing field tests in Uganda.
It is known that 1-2 nm zinc metal nanoparticles being added with odorant significantly enhance sense of smell. We can speculate that zinc nanoparticles play the role of electron donors in the interaction with olfactory receptors (Turin L. A spectroscopic mechanism for primary olfactory reception. Chemical Senses. 1996;21(6):773-91). We see that only small nanoparticles, smaller than 4 nm are physiologically active. Is there any physical rational for the size dependence? I guess, it should be a discrete dependence, not continues, as everything in a quantum physics. Good reference?
I'm actively looking for a library of olfactory receptor. The goal is to have the broadest diversity. Do you have any idea about academic or commercial resources? Any advice for generating such library? Thank you.
We are exploring the possibility of collecting biopsies or exfoliates from the nasal mucosa. What is the best and more reliable methodology? Has anyone ever tested which of neural precursors lines from nasal mucosa or from iPSCs show higher concordance with the patient genome?
Scent marking, integumentary glands, seasonal differences in scent marking, chemical communication in mammals
We want to produce PEX granule using Silane grafting method.However our final sample has an undesirable odor of silane. any idea how to reduce or totally eliminate that odor from the sample?
We'd like to look at gene expression profiles in olfactory/nasal epithelium but have no experience in isolating this tissue correctly. We'd like to investigate this both histologically (RNA in situ and or immunohistochemistry) and by quantitative RT-PCR. Any help or advice would be greatly appreciated!
how can i determine the taste detection threshold for difefrent compounds?
Coffee beans are used in perfume houses and sometimes left on counters selling fragrances (eg essential oils).
I found that gravid condition inhibits olfaction (need long time to give a response towards biopesticide odor). Can anyone provide me information to support this statement? Thank you so much
It is known that enantiomers of some compounds can elicit different behavioral or olfactory responses in several species. I would like to know if such differences can be explained by triggering different transduction pathways. For instance, can one enantiomer trigger the adenylyl cyclase pathway and other enantiomer the inositol phosphate pathway in the same receptor?
By associating olfactory cues to pain/no pain, drosophila and other animals can be trained to strongly avoid/prefer scents to which they were indifferent prior to training. Has anyone tried this with a "monoreceptor" animal, i.e. one where all but one olfactory receptor genes are knocked out? If you train using odorants known to be specific to the single remaining receptor the monoreceptor animal will likely behave no different than one with a full complement of receptors. What happens if one tried using odorant pairs that are known to NOT activate that receptor (e.g. in Ca++ influx or other assays). In other words, in the absence of other receptors, can training cause a receptor to expand its specificity to ligands it was previously "anosmic" to? We know point mutations tune a receptor's specificity, but what about post translational modifications or epigenetic changes effected by "training" of the molecule?
I have done tracksphere experiments of a pest caterpillar with Syntech Tracksphere LC 300. I have recorded the responses of the caterpillar towards 6 different plant leaf extracts, extracted in dichloromethane (uninfested and infested leaf extracts of 3 varieties). Five replicates were recorded for each extract, each time with a new caterpillar (separate recordings were done for dcm alone and for air). Can anyone please suggest a method for its statistical analysis?
I'm working on seal olfaction and did a PCA on a matrix of 220 scent compounds from 82 individuals. Is there a good way to figure out how many PCs may be relevant? I already did a scree plot and there are 3 'elbows' at PC´s 2,7,9. Also eigenvalues may be a criterion.
Why not some other number of TMs such as 3 or 5 or 9 which could still form binding pocket, have variable specificity, multiple activation modes etc. What's so magical about 7?
I have been looking for information indicating that humidity might be able to influence sensitivity and/or perceived odor quality in canine (mammal) olfaction. However I only found some correlations between canine detection probability of odor sources and humidity where humidity is (in my opinion) influencing the odor source and not the olfaction process. Does anyone know of any scientific reliable information that indicate that there is or is not an influence of olfaction by humidity?
By sampling headspace of plant volatiles by using PET oven bags we have sometimes measured contaminations by decanal and occasionally by different plant volatiles. Did you make similar experiences with such contaminations? We think the decanal is directly emitted by some charges of PET foil, while plant volatiles seem to penetrate the foil. This could be caused maybe due to quality differences of the product.
I am currently preparing a study that uses two odors, a pleasant one and an unpleasant one, as context cues, i.e., the odors will be dispensed in the experimental chamber and ss will perform a number of tasks. We have tried to match odor intensity by means of subjective intensity ratings on visual analog scales but the results were only partly satisfactory. In particular, different samples of ss (N=10 each) rated the intensity of the same concentration of the unpleasant odor significantly different while two different concentrations of the pleasant odor were rated different. Eventually the two odors were rated as iso-intense but I'm unhappy about how this aim was achieved. Any suggestions welcome.