HN user

Metacelsus

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Grad student working on in vitro oogenesis.

I write https://denovo.substack.com/

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www.nytimes.com 1mo ago

In a First, Scientists Precisely Edit Human Embryo Genes

Metacelsus
6pts1
www.science.org 2mo ago

Pushed by Trump policies, top U.S. battery scientist is moving to Singapore

Metacelsus
67pts37
reich.hms.harvard.edu 3mo ago

Ancient DNA reveals pervasive directional selection across West Eurasia [pdf]

Metacelsus
73pts70
www.nature.com 3mo ago

Investigating the replicability of the social and behavioural sciences

Metacelsus
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www.corememory.com 4mo ago

Ovelle Bio Wants to Give Women More Eggs

Metacelsus
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en.wikipedia.org 6mo ago

Prototaxites

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centuryofbio.com 6mo ago

Going Founder Mode on Cancer

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www.nytimes.com 8mo ago

Scientists Grow More Hopeful About Ending a Global Organ Shortage

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arxiv.org 9mo ago

An Introduction to Mars Terraforming, 2025 Workshop Summary

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www.nature.com 11mo ago

People are having fewer babies: Is it the end of the world?

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www.nytimes.com 11mo ago

How one company kept a US monopoly on fire retardant

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5pts0
www.futurehouse.org 12mo ago

About 30% of Humanity's Last Exam chemistry/biology answers are likely wrong

Metacelsus
3pts1
www.science.org 1y ago

CASP protein structure prediction contest may be eliminated due to NIH cuts

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www.sfchronicle.com 1y ago

California passes major overhaul of CEQA

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www.pnas.org 1y ago

Viable and fertile mice generated from two sperm using epigenetic editing

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3pts1
www.cell.com 1y ago

A wireless forehead e-tattoo for mental workload estimation

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en.wikipedia.org 1y ago

Qian Xuesen

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www.sciencedirect.com 1y ago

Near-infrared vision in humans enabled by upconversion contact lenses

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www.nationalchurchillmuseum.org 1y ago

Fifty Years Hence (Winston Churchill, 1931)

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2pts1
asteriskmag.substack.com 1y ago

We Can, Must, and Will Simulate Nematode Brains

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3pts0
www.science.org 1y ago

Vaccines Through Protein Degradation

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www.nature.com 1y ago

Heritable polygenic editing: the next frontier in genomic medicine?

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1pts0
www.asimov.press 1y ago

The Dangers of Mirrored Life

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www.science.org 1y ago

Many human infections with 'cow flu' are going undetected

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3pts0
www.science.org 1y ago

Complete fruit fly brain connectome unveiled

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www.sciencedirect.com 1y ago

Metformin decelerates aging clock in male monkeys

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www.science.org 2y ago

Scientists propose glacier geoengineering to avoid sea level rise

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www.science.org 2y ago

FDA advisory panel rejects use of MDMA for PTSD treatment

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en.wikipedia.org 2y ago

Schmidt Sting Pain Index

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twitter.com 2y ago

AlphaFold 3 Announced

Metacelsus
8pts2

The actual study: https://www.biorxiv.org/content/10.64898/2026.05.30.728989v1

Abstract:

Cas9-based tools enable the introduction of genetic lesions to investigate DNA repair outcomes and edit the genome at disease-relevant loci. DNA double-strand breaks (DSBs) induced by CRISPR/Cas9 result in frequent aneuploidy and large deletions, revealing a repair deficiency in early human embryos and limiting the clinical application of this technology. Here we evaluated the DNA repair outcomes of DNA nicks and mismatches introduced using base editors in human embryos at two targets, PCSK9 and HBG. Editing was efficient and, unlike Cas9-induced DSBs, did not result in either chromosomal abnormalities or large deletions. Small insertions or deletions after base editing were rare, and off-target activity was dependent on the guide RNA. Delivering the base editor as a protein at fertilization or at the pronuclear stage allowed normal development to the blastocyst stage and the derivation of edited stem cell lines. In stark contrast, introduction of the editor as RNA resulted in early embryo arrest. Our results demonstrated that, unlike DSBs, DNA nicks and mismatches are efficiently repaired in human embryos, allowing specific on-target changes without genotoxic consequences.

My overall thoughts: This type of study has been done in animals a lot (including primates) so it's not a surprise it works in humans too. Unlike He Jiankui's work, which was quite sloppy and rushed, this might actually be clinically useful.

See also the press release: https://hms.harvard.edu/news/massive-ancient-dna-study-revea...

This study covers about 10,000 years of recent human evolution in Europe and West Asia.

From the abstract:

in the past ten millennia, we find that many hundreds of alleles have been affected by strong directional selection. We also document one-standard-deviation changes on the scale of modern variation in combinations of alleles that today predict complex traits. This includes decreases in predicted body fat and schizophrenia, and increases in measures of cognitive performance. These effects were measured in industrialized societies, and it remains unclear how these relate to phenotypes that were adaptive in the past. We estimate selection coefficients at 9.7 million variants, enabling study of how Darwinian forces couple to allelic effects and shape the genetic architecture of complex traits.

Legit password resets for example come from more random top level domains with "microsoft" in it, like microsoftonline.com

Or aka.ms

25 Years of Eggs 4 months ago

And if the price reflected the externalities of factory farming, eggs would be even more expensive!

Gemini 3 Deep Think 5 months ago

According to benchmarks in the announcement, healthily ahead of Claude 4.6. I guess they didn't test ChatGPT 5.3 though.

Google has definitely been pulling ahead in AI over the last few months. I've been using Gemini and finding it's better than the other models (especially for biology where it doesn't refuse to answer harmless questions).

“The fact that the paper still exists means that medical students, pharmacy students, and, presumably, genetics students are being taught this as if it’s a real thing, and it has implications,” Juurlink told Scherer.

Yup. This paper was a lesson in my genetics class (2017)