Recent comments in /f/askscience

mayonnace t1_j4g2dsa wrote

Reply to Can a recessive gene become a dominant gene? If so, how long would it take? by Pretend-Recover-4418

I think, they are relative to each other. Like, dark eye color is dominant. Other gene might have been expressing its own color too, but the dark color is what we see effectively at the end.

Different genes may have different mechanisms, but the idea is how a single gene can't be enough for making that function effective.

For example, we might have three eye colors which, one is dominant to other, and the last one is recessive to both. Like, A > B > C or something. If gene A somehow would get disappear from the genetic pool, then we might start calling B simply a dominant gene, instead of comparing it with another.

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fleur_essence t1_j4g0y8w wrote

Reply to comment by Minute_Farmer in Is there physical differences between blood types? by terrip_t1

One caveat: while Rh is a protein, A and B are carbohydrate antigens.

For the most part, you can’t tell under the microscope a person’s blood type. However, some antigens, if they’re missing entirely, result in misshapen cells. For example, if missing all Rh antigens (not just the D that gives +/- as mentioned above) you get a shape called “stomatocyte”, where instead of a pale round area in the middle, it looks more like a closed mouth.

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catiecat25 t1_j4g038g wrote

Reply to How do the new generation of weight loss drugs (Semaglutide, tirzepatide) work and why are they seemingly so effective? by harpoonhambone

GLP1 (and GIP, tirzepatide is different than semaglutide, liraglutide, and other GLP1 agents as it works on both) moderate hunger/satiety. These agents help patients feel full quicker and stay full longer, helping to cut down on portion sizes, snacking, etc.

We’ve had Saxenda approved for years (liraglutide) and recently got Wegovy approved in 2021 (semaglutide), and hopefully will see tirzepatide approved for a weight management indication soon - currently is only approved under a diabetes indication. Wegovy, and tirzepatide for weight loss (see SURMOUNT clinical trials if interested) have demonstrated much greater weight loss than other indicated agents for weight management, approaching the amount of weight loss we see from some types of bariatric surgery.

These agents are a big deal in the management of overweight/obesity due to long term safety- patients stay on these agents for potentially their lifetime in the diabetes indication, and they are safe and continue to be effective. It’s truly a turning point in seeing and treating overweight/obesity as a chronic medical condition- not just a moral failing that quick diet/diet pill schemes can fix in a few weeks. As a provider that manages patients with chronic medical conditions, my patients on this class of medications for weight management are doing incredibly well- but as stated above, it HAS to go along with lifestyle modifications (exercise, dietary modification) and appropriate check ins with the medical team, just like any other chronic medical condition.

As a patient myself, I’ve lost a significant amount of weight with Wegovy over the past year and a half, and it has completely changed my outlook on my health, both physical and mental. I’m the healthiest I have ever been because I’ve been able to get control of the processes in my brain that encouraged me to eat, treat stress with desserts, and I finally feel in control of something I have never felt in control of before.

The issue is several insurance plans (including any government plans - Medicare, Medicaid, etc) do not cover treatment for weight management, as it was seen as ~cosmetic~ when these rules were initially put in place. That’s where the diabetes backorders came from- providers knew these agents would be clinically beneficial in their patients, but couldn’t get the “weight loss “ branded version, so prescribed the diabetes version.

I certainly wish the pharmaceutical companies (looking at you, Novo) would quit advertising Ozempic, Rybelsus, etc here on Reddit, and use that money to lobby Congress (why else are y’all employing Queen Latifah to be a spokesperson) to allow coverage of weight management treatments, now that we have safe and effective ways to manage it as a chronic condition.

Soapbox over.

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CrateDane t1_j4fvene wrote

Reply to Can a recessive gene become a dominant gene? If so, how long would it take? by Pretend-Recover-4418

It's not genes that are recessive or dominant, it's variants (alleles) of genes. A recessive allele is generally a gene that doesn't work, but if your other copy of the gene still works you still have enough activity to be unaffected. Changing that to a dominant allele isn't trivial. I can't come up with any examples of that happening quickly in evolutionary terms. On longer timescales it's easier, like if the gene product goes from acting as a monomer to a dimer and the broken allele then makes the dimer inactive - then the loss of activity can be enough to leave heterozygous individual affected.

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OverthrowYourMasters t1_j4fr8sl wrote

Reply to comment by higashidakota in How do we know oxygen, and not another element, is the third most abundant element in the universe? by ChickFleih

how are the odd numbered elements made and why are they so less abundant if hydrogen is the most common? wouldn't adding a hydrogen to an even pair be common? my uneducated hypothesis is that elements are layered inside stars, so they mostly interact at the layers. however, if this were the case, then squared elements would be the most common.

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WellQuiet t1_j4flqbj wrote

Reply to How do the new generation of weight loss drugs (Semaglutide, tirzepatide) work and why are they seemingly so effective? by harpoonhambone

These medicine are of a class called GLP-1 receptor agonists. They work by mimicking the effect of GLP-1 which is endogenous to the body. Normally enzymes in your body break down and inactivate GLP-1, these drugs however stay in circulation for days.

They were developed for diabetes because they lower blood sugar levels by stimulating the release of insulin when you eat -the main function of your body’s own GLP-1. But they found weight loss at pretty high levels, which is good for people with type 2 diabetes.

The exact weight loss mechanism is unknown, as far as I’m aware, but we do know there are GLP-1 receptors in the brain, and it seems to regulate appetite. People that take these medicine just eat less, they are even reported to enjoy food less.

There are in fact other effective weight loss medicines (amphetamine -like substances) but they suffer from side effects. It’s always complicated with drugs that affect the brain. So far the GLP1 class of drugs seem relatively safe. But unregulated use because people want to lose weight quickly is a bad thing imo.

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