Tag: science

Unintuitive RNA

RNA are much larger than Proteins

But we don’t have to get into such details in order to see how “off” our perceptions are. I, and probably many others, have a mental picture of an mRNA sequence being read out and transcribed into a larger protein, but that can’t be right. And it isn’t! In reality, the mRNAs are ~10x the size of proteins themselves. This feels wrong to us, because we’re used to our own preferences for algorithmic compression: blueprints are smaller than houses, but not inside the cell.

RNA Universal Computation

This demonstrates that universal computation is well within the reach of molecular biology. It is therefore reasonable to assume that life has evolved – or possibly began with – a universal computer that yet remains to be discovered.

Almost All the Stars

the formation of stars reached a peak 11 ga ago. The great majority of stars that the universe will ever make—perhaps 95%—have already been made.

COVID-19 Genome

Hello and welcome to my COVID-19 Genome Walkthrough. (Hoping someone comes out with that Vaccine Speedrun soon. This boss battle is really shaping up to be an intense one and we’ll need all the artifacts we can get.)

Life’s Energy Limits

For individual cells, this power minimum hovers around a zeptowatt, or 10−21 watts. That is the power required to lift 0.001% of a grain of salt 1 nanometer once a day. (For reference, a human body uses ~100 watts, the power of a reading light.) The new model suggests that cells living in sub-seafloor sediments are drawing only slightly more power than that.

2022-11-02: Inert spores may be close to that energy limit, and use a passive sensing technique.

The spores might be able to sense small cumulative changes in their environment, until enough signals build up to trigger a sort of wake-up alarm. The mechanism that would induce these changes would be the movement of ions out of the cell—specifically, potassium ions.

These movements can be triggered by positive environmental signals, like the presence of nutrients. When the ions travel out of the cell thanks to passive transport, they generate a difference in potassium concentration inside versus outside the cell. This concentration difference allows the spore to store potential energy. Over time, as the spore continues to sense more positive signals, more ions would move out of the cell. This would also create a corresponding drop in potassium levels, as the ions exit. Eventually, the potassium content in the spore would lower to a certain threshold, signaling that it is safe for the cell to wake up. That would trigger reanimation and germination.

2024-07-23: Most life is dormant

60% of all microbial cells are hibernating at any given time. Even in organisms whose entire bodies do not go dormant, like most mammals, some cellular populations within them rest and wait for the best time to activate. esearchers reported the discovery of a new hibernation factor, which they have named Balon. The protein is shockingly common: A search for its gene sequence uncovered its presence in 20% of all cataloged bacterial genomes. And it works in a way that molecular biologists had never seen before.

Previously, all known ribosome-disrupting hibernation factors worked passively: They waited for a ribosome to finish building a protein and then prevented it from starting a new one. Balon, however, pulls the emergency brake. It stuffs itself into every ribosome in the cell, even interrupting active ribosomes in the middle of their work. Before Balon, hibernation factors had only been seen in empty ribosomes.

Mitochondria stress response

Mitochondria may hold keys to anxiety and mental health

Mitochondria seem to be central to the very existence of a stress response, serving both as mediators of it and targets for the damage it can do.

Proteus

The indestructibility of this new aluminum foam metal relies on an embedded ceramic material

Ancient Egyptian Tattooing

It seems that women were primarily being tattooed The tattoos from Deir el-Medina are on women associated with temples as priestesses, who had roles in singing and dancing and performance. The most eye-opening find was a single mummy that bore at least 30 tattoos, based on the current analysis. Some of the tattoos, adorning the arms, chest, and neck, were visible with the naked eye—and sound more Brooklyn than Egypt.

2021-09-29: Now combine that with DNA facial reconstruction

Mummy samples were estimated to be between 2023 and 2797 years old. Researchers performed enzymatic damage repair on each mummy before conducting DNA sequencing. Then Parabon used the resulting whole-genome sequencing data and selected 3 samples with the highest quality to analyze. The This is the first comprehensive DNA phenotyping the company has performed on human DNA of this age. They used Snapshot, a phenotyping method to predict the ancestry of mummies, to predict the ancestry, pigmentation, and face morphology of the 3 mummies. The overall genetic makeup of the mummies is closer to the modern Mediterranean or the Middle East people than modern-day Egyptians. Researchers generated 3D meshes for the outline of the faces and calculated heat maps to highlight differences between the 3 faces. They combined these results with the Snapshot predictions and reveal that the mummies once had light brown skin with dark eyes and hair.

Academic whistleblower

Journal editor breaks protocol to thank an anonymous whistleblower. Perhaps the scientific process is slowly getting better?

Hybrid Fish

Sturddlefish go shockingly far beyond classic crossbreeds like mules and ligers, whose parent species sit close together on the tree of life. Sturddlefish result from the merger of different taxonomic families. It’s like if they had a cow and a giraffe make a baby. Then he quickly corrected himself, because the lineages of those 2 ruminants split only 40 ma ago. The evolutionary paths of paddlefish and sturgeons diverged 184 ma ago. For those fish to breed is more like if a human came out of a platypus egg.