Recent comments in /f/askscience

fayalit t1_j72cf0v wrote

Reply to comment by CrustalTrudger in Do we have any records of meteor impacts on the moon? Is there any way to monitor this? by AnonymousAutonomous

I'm curious about whether it would be possible to create a calibrated dating curve for lunar impact craters similar to how LaHusen et al., 2016 did for landslides in a particular river valley in Washington.

I vaguely remember hearing that, similar to landslides, impact craters start out with a high surface roughness but become smoother over time. This presupposes high quality DTMs of the lunar surface so it's purely theoretical. But I'm curious if it's possible to calibrate a roughness curve with some absolute dates or if the surface processes or timescales are just too dissimilar to be comparable.

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FirstSynapse t1_j72b0mn wrote

Reply to comment by Foreign_Implement897 in Back in the late 90s, I remember hearing that scientists “cloned a sheep”. What actually happened with the cloning, and what advancements have been made as a result of that? by foxmag86

If you mean embryonic stem cells, their main advantage over iPSCs is that ESCs have been around for longer and can be considered somewhat more reliable. iPSCs need to be generated in the first place from mature cells, and although this process is relatively simple (only four factors in the case of Yamanaka's Nobel prize-winning research), there is still a lot of debate over how it should be done and how it can affect the resulting phenotypes.

ESCs, on the other hand, are already naturally capable of generating tissues, so there is a larger likelihood that the resulting mature cells will resemble more the actual human ones. In studies in which the mutations of the diseases that are being studied are generated by genetic manipulation, ESCs are still preferred by many labs because of this reason.

But this is an issue for iPSCs just because it is still a very young technology, and huge advances are being made constantly that make ESCs less relevant. Being able to obtain cells directly from patients is a huge advantage as it allows to study diseases that have an important but not entirely known genetic component, like most neurological disorders.

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CrateDane t1_j7297wt wrote

Reply to comment by EducationalCan3358 in Back in the late 90s, I remember hearing that scientists “cloned a sheep”. What actually happened with the cloning, and what advancements have been made as a result of that? by foxmag86

No, CAR-T simply uses T cells extracted from an adult. Either the patient themselves or a donor. The cells are then gene edited to express the chimeric antigen receptor, and the successfully edited cells are put back in the patient.

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FirstSynapse t1_j727ikl wrote

Reply to comment by ElxirBreauer in Back in the late 90s, I remember hearing that scientists “cloned a sheep”. What actually happened with the cloning, and what advancements have been made as a result of that? by foxmag86

It is pretty nice, and the models get better every day. As a caveat, I must say that there are LOTS of things to consider when doing research with iPSCs, mainly related to how accurately your cells represent actual human cells. For example, I work with iPSC-derived neurons and any change in the process of maturation of iPSCs into neurons vastly changes the properties of the final cells. Also, neurons and other cell types take long to mature from iPSCs. In the case of my cells, it takes around two months until they are at a stage I can use for my experiments, and they have to be maintained for that long and lots of things can go wrong.

All of this is, of course, also a problem with ESCs, but not with animal models. If human genetics are important for your experiments, iPSC models are almost the only choice you have. If there is a good animal model for the disease you're studying and organism physiology is more important, then animal models are better.

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to_old_for_that_shit t1_j71zji9 wrote

Reply to Are plants growing from cuttings as healthy as those grown from seed? by [deleted]

The whole weed industry lives on doing cuttings from the best mother plants and putting them in small root cubes until that cube is fully rooted through, then put them in bigger pots to mature

I suggest not puting the cuttling deeper then half an inch into very little earth, like 2-3 kubic inch of earth Put a see through cover on it to keep moisture trapped until some roots are there (3-5 days) make sure to air it out and keep from getting dry

Clonex or something similar may help the cuttlings getting roots quicker and more reliable..

The „new“ plants should be just as healthy as seed grown depending on how good/bad the mother is doing

Good luck

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