Does sunscreen block the synthesis of both vitamin D and β-endorphin in the skin when out in the sun? |
- Does sunscreen block the synthesis of both vitamin D and β-endorphin in the skin when out in the sun?
- AskScience AMA Series: We've discovered that pancreatic cancer is detectable based on microbes in stool, with the potential for earlier screening in the future. AUA!
- Is baleen modified teeth? Or what?
- What part of the olfactory system distinguishes mirror molecules?
- How does formaldehyde preserve tissue?
- Why were offspring of cross-bred hominids (e.g., Homo sapiens and homo neanderthalensis) viable to breed, but other cross-bred species like mules or ligers are infertile?
- Why do a lot of numbing chemicals/medicines end in the word “Caine”?
- Do insects like ants or bees have a proper sleep cycle?
- Why are some magnets more powerful than others? Can any given magnet be made more or less magnetic? Is their a theoretical or real limit to how powerful a magnet can be?
- Are there diseases that cause temporary loss of senses besides taste and smell?
- Are there electronic devices to substitute sniff dogs for forensics?
- Under what geographic conditions do salt mines form?
- What is the likelihood of getting long-lasting neurological issues after an infection with Covid-19?
- Do teeth whitening procedures whiten the dentin part of a tooth?
- Can a single electron produce magnetic field?
- is there such a thing as a liquid that is flammable in its liquid state?
- Does increase in dopamine signaling in the mesolimbic pathway DRIVES engagement with the stimuli (craving), or does the increase in dopamine signaling FOLLOWS the engagement with said stimuli?
- Why do fangtooth moray eels have transparent teeth?
- Are there any saltwater lakes with an outflow?
- How much CO2 is in the Martian poles?
- What biome has a lot of microeukaryotes (e.g., protists, fungi) besides marine and human gut?
- What cations/anions can't move past a salt bridge like one seen in a galvanic cell? If said ions exist, why cant they move past said salt bridge?
- Monarch butterflies are shown to very rarely be white, but it is not albinism, can butterflies be albino?
| Posted: 21 Mar 2022 08:44 PM PDT Does it block one or the other? Are vitamin D and β-endorphin synthesis both mediated by the same spectrum of UV light? Relevant paper on β-endorphin addiction to UV light: [link] [comments] |
| Posted: 21 Mar 2022 04:01 AM PDT Hi Reddit! We are Ece Kartal (u/psecekartal), Sebastian Schmidt (u/TSBSchm) and Esther Molina-Montes (u/memmontes). We are lead authors on a recently published study showing that non-invasive (and early) detection of pancreatic cancer may be possible using stool samples. Ask Us Anything! Pancreatic cancer is a horrible disease: although few people develop this form of cancer, only around 1 in 20 patients survive for 5 years or longer after diagnosis. This is in part due to late detection: symptoms are unspecific and often occur only when the disease has already progressed to advanced stages, so that diagnosis if often too late for therapeutic intervention (surgery and/or chemotherapy). This makes the earlier detection of pancreatic cancer an important goal in mitigating the disease, yet no approved non-invasive or minimally invasive, inexpensive tests currently exist. We studied a Spanish population of patients diagnosed with pancreatic ductal adenocarcinoma (PDAC, the most common form of pancreatic cancer) and clinically matched controls that were either pancreas-healthy or suffered from chronic pancreatitis (inflammation of the pancreas, an important risk factor for the development for PDAC). We found that a set of 27 microbial species detected in feces provide a very specific signature for PDAC patients, even in early stages. When combined with a blood serum-based cancer progression (not diagnostic) marker, prediction accuracy increased even further. We confirmed this finding in an independent German cohort, and also made sure that this microbiome signature did not falsely predict PDAC among thousands of subjects that were either healthy or suffered from other diseases. Moreover, we were able to trace some of these signature microbes between mouth, pancreatic healthy tissue, pancreatic tumors, and the gut which suggests that they may be more than just indicators. Our study is freely available online in the journal GUT (Kartal, Schmidt, Molina-Montes, et al; 2022): https://gut.bmj.com/content/early/2022/01/26/gutjnl-2021-324755 A commentary by R. Newsome and C. Jobin in the same issue puts our work into context: https://gut.bmj.com/content/early/2022/02/21/gutjnl-2021-326710 For less formal introductions, check the press releases by one of our funding bodies (Worldwide Cancer Research) or the lead institutions EMBL Heidelberg, Germany and CNIO Madrid, Spain (text in Spanish). Our work is an early proof of principle and will need to be further validated on larger and independent cohorts. Yet our findings hold some promise for a future inexpensive, non-invasive screening method for pancreatic cancer. Such a screen could initially target risk groups, e.g. above a certain age or with a family history of PDAC. Ideally, with further development and in combination with other biomarkers, our approach might be developed into an actionable diagnosis method in the future. That said, none of us is a medical doctor; we cannot and will not provide any medical advice, and none of what we post here should be construed as such. We will be on at Noon Eastern (16 UT), and are looking forward to your questions, AUA! Who we are:
[link] [comments] |
| Is baleen modified teeth? Or what? Posted: 22 Mar 2022 03:47 AM PDT What's the origin of baleen? Is it modified teeth? Modified bone? Something else? How did it arise? What was the transition between toothed ancestors and baleen whales look like? [link] [comments] |
| What part of the olfactory system distinguishes mirror molecules? Posted: 21 Mar 2022 07:39 PM PDT Caraway smells like spearmint to me--to the point where Rye bread tastes like toothpaste, and I can't eat it. It doesn't seem that is very common. I know that carvone is the chemical that makes spearmint taste like spearmint and caraway taste like caraway (whatever that means), but they are mirror molecules, and most people perceive them differently. So, what causes this? [link] [comments] |
| How does formaldehyde preserve tissue? Posted: 21 Mar 2022 02:41 PM PDT And does it work in all species? Would it work for a fish? [link] [comments] |
| Posted: 21 Mar 2022 08:28 PM PDT |
| Why do a lot of numbing chemicals/medicines end in the word “Caine”? Posted: 21 Mar 2022 04:41 PM PDT Examples: lidocaine, novocaine, benzocaine, tetracaine ect. [link] [comments] |
| Do insects like ants or bees have a proper sleep cycle? Posted: 21 Mar 2022 07:06 PM PDT |
| Posted: 21 Mar 2022 06:04 AM PDT |
| Are there diseases that cause temporary loss of senses besides taste and smell? Posted: 21 Mar 2022 05:07 PM PDT I know that colds and other similar diseases can cause temporary loss of taste, smell, or both. Are there others diseases that can cause a temporary loss of other senses? Sight, hearing, or touch? [link] [comments] |
| Are there electronic devices to substitute sniff dogs for forensics? Posted: 21 Mar 2022 08:42 AM PDT Is a device that sniffs illicit substances around a house a thing that is possible ?? If it exists, why didn't it replace sniffing dogs already? (Sorry for the flair, wasn't sure which flair fits.) [link] [comments] |
| Under what geographic conditions do salt mines form? Posted: 21 Mar 2022 08:59 AM PDT I am writing a novel where salt is an even more important item than in real life and so a big part of the setting has to do with salt production and trade. I know I can't be 100% accurate but I wouldn't want my geography to be outrageous and have salt mines where it would make no sense. Are there any specific geographic conditions for salt mines to form? Like, does the place need to be arid or humid? Cold or warm? Near the coast or deep inland? I have researched a bit about how they get formed but I'm not entirely sure about these more pop-science questions. Feel free to give me any tips or further information on this! [link] [comments] |
| What is the likelihood of getting long-lasting neurological issues after an infection with Covid-19? Posted: 21 Mar 2022 05:09 AM PDT Curious about any well-made studies on the topic, happy to read any links by myself. It seems to me like earlier studies often lacked a control group of non-infected people, and therefore could not give a reliable answer with regards to the difference Covid makes. [link] [comments] |
| Do teeth whitening procedures whiten the dentin part of a tooth? Posted: 21 Mar 2022 07:14 AM PDT During a teeth whitening procedure, does the hydrogen peroxide/carbamide peroxide penetrate the enamel and reach the dentin part of the tooth? If yes, does it provide a whitening effect to the dentin (naturally yellow) part of the tooth? [link] [comments] |
| Can a single electron produce magnetic field? Posted: 21 Mar 2022 07:53 AM PDT |
| is there such a thing as a liquid that is flammable in its liquid state? Posted: 21 Mar 2022 08:13 AM PDT Or are only their vapors flammable? Is it even possible to know since only the top layers of atoms are exposed to oxygen, so we'd never see lower layers burn before those above vaporized and/or burned? [link] [comments] |
| Posted: 21 Mar 2022 05:02 PM PDT I've been trying to understand the involvement of dopaminergic system in addiction (and reward processing at large). However, I am unable to fully understand the very fundamental principle of what exactly drives an individual to act: is it increased dopamine signaling in the striatum (upon presentation of a cue) which facilitates seeking behavior for a particular stimuli (associated with the cue)? Or is it the lack of dopamine signaling that forces an individual to engage with the stimuli which in turn results in dopamine signaling increase AFTER the engagement with the stimuli? The classic Schultz et al. study led me to believe that an increase in dopamine signaling precedes the engagement with the stimuli and is observed upon the presentation of a cue, in turn leading to craving. By this logic, I assumed that an increase in dopamine signaling in the striatum would facilitate craving and the associated seeking behavior. Similarly, a study investigating the effect of chronic cannabis (THC) exposure in mice reported elevated levels of D2/3 (dopamine) receptors in the striatum after 3 weeks of daily THC injections, suggesting hypersensitivity to dopamine and would explain addiction associated with THC, since repeated use would make striatum more sensitive to dopamine and would result in stronger craving. Moreover, it would explain why during the initial stages of withdrawal, a risk of relapse would be greater, since the striatum would be more receptive to dopamine (due to more readily available D2/3 receptors) in the presence of a cue, facilitating a stronger motivation to seek cannabis in an addicted individual compared to someone whose D2/3 receptors are at baseline levels. However, this model that started to make sense in my mind was shattered by findings of dr. Nora Volkow, who is somewhat of an authority in addiction research. In her paper that evaluated dopamine signaling in marijuana users, she concludes that marijuana users demonstrate "[...] reduced brain reactivity to dopamine stimulation that in the ventral striatum might contribute to [...] drug craving". Moreover, in her papers on changes in dopamine signaling in users of other drugs (e.g. cocaine, opioids) she demonstrated reduced levels of D2/3 receptors in the striatum which, in her opinion, contributes to addiction. She even makes a case that individuals with inherently lower D2 receptor availability in nucleus accumbens are more susceptible to addictions. Interpreting this hypothesis by applying the previously laid out logic results in a contradiction. If increase in dopamine signaling increases the craving for a stimuli and facilitates addiction, how could a lower availability of D2 receptors in the striatum result in elevated drug craving? If Volkow model is accepted, then it would be the deficiency of dopamine signaling that would create a craving, in turn suggesting that after the engagement with the stimuli, dopamine signaling would increase. In other words, an addicted individual would be seeking the stimuli to increase the dopamine signaling, rather than increased dopamine signaling driving the individual to engage with the stimuli. I do understand that I am probably missing some essential details here (like the role of presynapting autoregulating dopamine receptor availability, for example), but I feel like I am stuck in understanding the basic principle upon which all of the aforementioned studies are build on. [link] [comments] |
| Why do fangtooth moray eels have transparent teeth? Posted: 21 Mar 2022 04:49 PM PDT https://www.fishbase.in/summary/Enchelycore-anatina.html There's little surprise why these things are named after their teeth. On top of being many, sharp, and big, they're transparent! But I haven't found much documentation of why online. I will note that eels' whole bodies are transparent when they're babies; could that have something to do with it? [link] [comments] |
| Are there any saltwater lakes with an outflow? Posted: 21 Mar 2022 04:05 PM PDT I understand most saltwater lakes are so because they are formed on endorheic basins, but is there any exception to the rule? Something like a saltwater river? [link] [comments] |
| How much CO2 is in the Martian poles? Posted: 21 Mar 2022 08:23 AM PDT If you somehow melted all the CO2 dry ice at the polar ice caps on Mars. Let's say with some kind of mirror system. What atmospheric pressure would the planet reach? Would it reach/surpass the Armstrong limit? (6kpa or 0.06atm) [link] [comments] |
| What biome has a lot of microeukaryotes (e.g., protists, fungi) besides marine and human gut? Posted: 21 Mar 2022 05:07 PM PDT I'm looking for a dataset that will have a lot of microeukaryotes but I'm not sure which microbiomes to look through? I know marine environments do but I need something else. Same with gut. [link] [comments] |
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