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Using a combination of modern cell biology techniques, including #trafficking assays, #CRISPR, and secretomics, Pereira, Stalder, David Gershlick et al. Cambridge University reveal that the exocyst complex has a fundamental role in protein secretion.

16,269 görüntüleme • 3 yıl önce •via X (Twitter)

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The most detailed 3D reconstruction of a cell ever created. Blows my mind every time. But what exactly are we looking at here? The average human cell contains: ~ 15-20 total distinct organelle types, totalling between ~1-10 million working together per cell. All these nano-machines in the cell are made up of proteins. ~ 8,000-10,000 distinct types of unique proteins, adding up to between 40 million - 10 trillion total proteins making up all those cellular systems. ~ 10,000 - 15,000 distinct types of RNA shuttling information around the cell, totalling up to ~10 million RNA molecules moving around the cell simultaneously. ~ Billions of Lipid molecules packed together into the cell membrane, which is also packed tightly with millions more protein-based nano-machines. And let's not forget billions of lines of DNA information to build and run it all. That's TRILLIONS of of individual molecular pieces working together to make a single cell function. That means there is more complexity in a single cell than humanity's largest cities. And people still believe this wasn't Divinely Designed. This is God's Glory on Display. But to make the point. A cell couldn't have evolved from some nebulous simpler "protocell" because even the simplest cells still require massive complexity. The "simplest" cell ever created was engineered by scientists knocking out pieces of a functional cell until it stopped functioning. Here is what they found is the absolute necessary minimal requirements of a cell to function: - Over ~531,000 lines of coded DNA information - 473 total genes to create hundreds of unique protein products (they later added 19 genes back in because the cell was so weak) - Hundreds of thousands of total proteins all working together - Extensive regulatory networks guiding all these interactions If the cell doesn't have all these systems in place, from the start... it doesn't live. Cell rely on an intricate network of complex systems, which are themselves built from complex interconnected pieces woven together into an incomprehensibly complex web of functionilty. Only intelligence has ever been observed creation vast interconnected systems like this. Life was clearly Created. It couldn't happen any other way.

Divinely Designed

165,777 görüntüleme • 1 ay önce

To replace animal testing with AI, we need MASSIVE human datasets. Today, we're thrilled to share Axiom's new data exploration tool, providing the ability to visually explore the world's largest primary human liver toxicity dataset. Built with Axiom's proprietary wetlab protocols, our dataset includes detailed liver toxicity profiles for over 100,000 distinct molecules. The key to this dataset is our ability to do high-throughput, multiplexed high-content screening with primary human liver cells. Traditionally, toxicity assays either sacrifice throughput or sacrifice biological relevance (using easy-to-grow immortalized cell lines instead of real human cells). We managed to combine throughput, physiological relevance, and multiplexing in one platform. The assays run in a high throughput format using automation, meaning thousands of compound-dose conditions can be tested in one experiment. We achieved this using pooled primary human hepatocytes, which are often fragile and expensive. By systemizing our automation and quality control processes, we were able to run over 120+ batches on the same donor pool with incredible reproducibility and consistency. We did this while integrating many readouts per well, whereas many existing toxicity assays only do a single readout. Our multiplexed approach provides far more data per experiment enabling us to measure 10-20 different toxicity phenotypes such as apoptosis, necrosis, mitochondrial fission, endoplasmic reticulum stress, stress granule formation, microtubules, and more all from a single well on a 384-well plate! The combination of scale, high content information, and data quality is exactly what is needed to train highly accurate AI models in biology. If you're interested, please explore the dataset in the comments below and let me know if you want to chat about the details!

Brandon White

25,117 görüntüleme • 1 yıl önce

A pro-Palestinian 🇵🇸 group slashed and spray-painted a century-old portrait of the author of the Balfour Declaration at the University of Cambridge in England 🏴󠁧󠁢󠁥󠁮󠁧󠁿 In March 2024; a pro-Palestinian group slashed and spray-painted a century-old portrait of Arthur James Balfour at the University of Cambridge on Friday, defacing a painting of the British official whose pledge of support in 1917 for “the establishment in Palestine of a national home for the Jewish people” helped pave the way to Israel’s founding three decades later. The group, Palestine Action, said in a statement that the destruction of the portrait in Trinity College, Cambridge, was intended to call attention to “the bloodshed of the Palestinian people since the Balfour Declaration was issued,” particularly in light of the current conflict in Gaza. A spokeswoman for Trinity, whose alumni include King Charles III as well as Balfour himself, said in a statement on Friday that the college “regrets the damage caused to a portrait of Arthur James Balfour during public opening hours” and that it had notified the police. A Cambridge police statement said officers were on the scene to investigate a report of “criminal damage.” Palestine Action posted a video of a protester first spraying the portrait, painted in 1914 by Philip Alexius de László, with red paint and then slashing it with a sharp object. The group’s statement said Balfour had given away the homeland of the Palestinians — “a land that wasn’t his to give away” — touching off what it described as decades of oppression. Since October 7 - 2023, when Hamas militants invading southern Israel killed approximately 1,200 people and abducted 240 others, Israeli bombings and invasions have killed more than 30,000 people, according to Gaza health officials. Defacing art has become a popular protest tactic in recent years. It is perhaps most closely associated with environmentalists, who have targeted paintings by van Gogh, Vermeer and Monet. In 2024, two women from an environmental group entered the Louvre and flung soup at the Mona Lisa. Most of the paintings that have been targeted were covered or protected in some way, and very few were damaged. The pro-Palestinian protesters have targeted art in New York. A few dozen demonstrators disrupted the opening of an Israeli artist’s show at a Manhattan gallery, Hyperallergic reported. In February 2024, protesters interrupted a conversation featuring an Israeli artist whose drawings depicting October 7, 2023 are being exhibited at the Jewish Museum and dozens chanted “Free Palestine” in a demonstration at the Museum of Modern Art. © The New York Times #archaeohistories

Archaeo - Histories

29,959 görüntüleme • 1 yıl önce

Facial reconstruction of a 315,000-year-old man from Morocco The first discovery at the Jebel Irhoud site was made in 1961, when a remarkably complete skull of an archaic human was unearthed. Subsequent excavations revealed another cranial vault, the mandible of a child, and several additional bone fragments. The site has been dated multiple times, with estimates ranging from 30,000 to 190,000 years ago. By 2007, the accepted age was approximately 160,000 years. However, new analyses conducted by the same research team demonstrated that the Jebel Irhoud deposits are significantly older, dating between 240,000 ± 35,000 and 378,000 ± 30,000 years ago, with an average age of approximately 315,000 ± 34,000 years. The Jebel Irhoud individuals occupy an intermediate position between modern humans (including Upper Paleolithic Cro-Magnons) and more archaic groups such as Heidelberg humans, Neanderthals, and African Middle Pleistocene populations. This pattern is evident across nearly all studied anatomical features, including the skull, mandible, brain, and dentition. The occipital and temporal bones of Irhoud 1 retain several archaic characteristics, whereas the frontal bone exhibits more derived traits. The face of Jebel Irhoud 1 is essentially indistinguishable from that of modern humans and, in some respects, appears even more modern than that of certain Upper Paleolithic Homo sapiens specimens. The mandible displays a receding chin, although a very weak indication of chin prominence may be present. Considered in isolation, the jaw appears relatively archaic; however, in combination with the facial morphology, it does not seem particularly primitive. Viewed from a three-quarter angle, Irhoud 1 appears remarkably modern, while its archaic features become most apparent in profile. The cranial vault bones of Jebel Irhoud 1 are thick, and the vault itself is low and elongated. The forehead is low and receding, although less sloping than that of European Neanderthals. The brow ridge is massive, postorbital constriction is pronounced, and the occipital region exhibits a chignon-like morphology. The mandibular fossa of the temporal bone is moderately deep and spacious. The articular eminence is well developed, and the postglenoid process is large. The face is extremely high and broad. The upper face is relatively flattened, while alveolar prognathism is strongly expressed. The orbits are tall and square-shaped, and the nose is very broad. A canine fossa is absent, and the alveolar process is high. The teeth are large. The brain morphology resembles that of the Kabwe (Broken Hill) specimen. Cranial capacity has been estimated at 1,305–1,480 cm³. (Hublin et al. (2017), Richter et al. (2017), Antropogenez, S. Drobyshevski (2017)).

Ancestral Whispers

106,977 görüntüleme • 1 ay önce

The bacterial flagellum looks like a simple tail, or whip. But it’s actually a rotating motor, and perhaps the most sophisticated protein complex nature has ever evolved. In e. coli, these motors are capable of astonishing speeds; about 15,000 rpm. (The world record, according to one study, is for a Vibrio cell that was “clocked at 100,000 rpm by laser microscopy.) The flagellum propels the cell forward at speeds of 20-30 microns per second, or roughly 15 body lengths per second. If scaled up to the size of a cheetah, E. coli would *nearly* be the fastest land organism. The darting movements of a microbe were first observed in 1676 by Antony van Leeuwenhoek, a Dutch cloth merchant. Antony was delighted by the motion of his “animalcules,” writing: “I must say, for my part, that no more pleasant sight has ever yet come before my eye than these many thousands of living creatures, seen all alive in a little drop of water, moving among one another, each several creature having its own proper motion.” But Leeuwenhoek did not see flagella. He assumed, rather, that these animalcules must be “furnished with paws” instead. Christian Ehrenberg would not properly describe flagella until 1836. But amazingly, all the way up until the 1970s, nobody actually knew how the flagellum spun! In 1973, there were two competing models people argued over: the helical-wave (bending) model and the rotating (corkscrew) model. The first model suggested that the flagellum whipped back and forth, side-to-side, to propel the cell like paddle. The corkscrew model suggested that the whole flagellum instead spins around like a screw. In 1974, the corkscrew model finally won out. For two separate studies, scientists affixed flagella to glass slides using antibodies, and watched as the cells spun around and around like corkscrews. And finally, in just the last year, high-resolution structures of the flagellum have revealed a LOT more about its intricate assembly. The tail is made from ~20,000 self-assembling copies of a single protein, called flagellin. A “driveshaft,” or rod, spins the tail and is itself made of 26 protein subunits. Each “motor” in E. coli consists of 11 stators, each of which is made from 7 proteins.(Other types of cells have even more stators, and swim with much higher torques.) The flagellum spins when protons flow into the cell through tiny channels in these stators; akin to water running through a turbine. Each proton makes a small part of the stator change shape and push against the rotor, nudging it forward one step. With dozens of stators working at once, these nudges quickly spin the propeller. I'm writing an essay for Asimov Press about this now, and am really enjoying learning about the flagellum and its history. It's an extraordinarily complicated structure, though, and has been a challenge to understand!

Niko McCarty.

51,893 görüntüleme • 11 ay önce

✅Explanation of Meaning (by parts): 1. “Having studied and confirmed that biological evolution on planet Earth” : The author begins by referencing the study of biological evolution on Earth, asserting that scientific investigation has established a clear understanding of its processes, setting a foundation for further claims. 2. “which gave birth to all living things” : Evolution is credited with the origin of all life on Earth, emphasizing its role as the mechanism through which the diversity and complexity of living organisms, including humans, arose over billions of years. 3. “had no purpose” : The author asserts that this evolutionary process lacks a predetermined purpose or intentional design, suggesting that life’s development is driven by natural, undirected mechanisms like mutation and selection, not a teleological goal. 4. “one can easily find answers to other fundamental questions of existence” : By accepting evolution’s purposelessness, the author claims that it becomes simpler to address broader existential questions, implying that this understanding provides a framework for tackling issues like the meaning of life or the Universe’s nature. 🗝️Main Idea (refined version): The author asserts that scientific study confirms biological evolution on Earth, which produced all life, operates without purpose, driven by natural mechanisms rather than intentional design. This understanding facilitates answers to fundamental existential questions, offering clarity on life’s meaning and our place in the cosmos. Recognizing evolution’s purposelessness challenges teleological views, fostering a perspective rooted in empirical reality. It encourages humility, acknowledging our existence as a product of chance rather than destiny. This insight simplifies complex philosophical inquiries, aligning them with scientific principles. It inspires a rational approach to exploring existence, free from preconceived notions of purpose. Ultimately, it empowers us to construct personal and collective meaning within a Universe governed by natural laws, embracing our role as products of a remarkable, undirected process.

Zafar Mirzo | Quotes

2,924,909 görüntüleme • 1 yıl önce