- Last 7 days
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aeon.co aeon.co
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Thus English is indeed an odd language, and its spelling is only the beginning of it.
I feel that there are multiple "acceptable" ways to say the same thing in English. The various ways make English more odd that other languages.
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I should make a qualification here. In linguistics circles it’s risky to call one language ‘easier’ than another one, for there is no single metric by which we can determine objective rankings
I think that on a individual level, even though most of have been exposed to English since birth, we can find a language easier or harder based on experience, media, and location. Every way we learn anything can affect how difficult we find it based on our needs.
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- Oct 2024
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www.youtube.com www.youtube.com
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1:04:44 Debt mirrors in NATURE as the seeds, plants, trees, flowers, roots, soil, water, nutrients, pollinators, worms, rock and minerals - WE ARE IN DEBT TO NATURE - NATURE GIVES US SURPLUS
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- Mar 2023
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scitechdaily.com scitechdaily.com
- Feb 2023
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www.biorxiv.org www.biorxiv.org
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Review coordinated by Life Science Editors.
Reviewed by: Dr. Angela Andersen, Life Science Editors
Potential Conflicts of Interest: None
Background: The ability to reproduce decreases with age in many animals - including humans and worms. Oocytes age earlier than other tissues, and their decline in quality contributes to reduced reproduction. Diminished mitochondria number/activity in human oocytes correlates with age-related decline.
Question: Does mitochondrial dysfunction cause (or just correlate with) reduced egg quality?
Summary: The authors compared the proteomes of mitochondria isolated from young worms, old worms and daf-2 mutant worms (c. elegans) (insulin/igf-1 receptor mutant) that have longer lifespans & longer reproductive lifespan. * Mitochondria from young & mutant worms had high levels of BCAT-1 (branched chain aminotransferase). * RNAi of bcat-1 reduced the longevity, reproductive longevity & egg quality of daf2 mutants, and increased mitochondrial activity/mtROS. * Similar effects of bcat-1 kd in wt worms, but interestingly the effects on reproductive longevity were more severe in wt than daf2 mutants (from a quick look), but there was no effect on lifespan in wt animals. * Overexpressing bcat-1 in wt extended reproduction & egg quality but not lifespan. * Treating animals with vitamin B1 (a cofactor downstream of BCAT1 in BCAA metabolism) delayed reproductive aging, slightly extended lifespan, improved oocyte quality, reduced mtROS in aged worms..
Advance: BCAT-1 levels/BCAA metabolism correlate with mitochondrial quality & reproductive longevity. Vit B1, which promotes BCAA metabolism, can extended reproductive longevity.
Significance: More/strong evidence that dysfunctional mitochondria cause a decline oocyte quality, reduce reproductive longevity. If vitamin B1 supplements are a safe way to delay age-related decline of eggs in female mammals (humans) that would be amazing. .
Ang asks:
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is this effectively dietary restriction of BCAA? Would that be a better (albeit perhaps more difficult to sustain) approach?
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How does this relate to some recent papers pointing out that mitochondria in eggs are special (e.g. Cheng et al. Mammalian oocytes store mRNAs in a mitochondria-associated membraneless compartment, Science 2022; Rodriguez-Nuevo et al., Oocytes maintain ROS-free mitochondrial metabolism by suppressing complex I, Nature 2022) and a role for BCAA in longevity (e.g. Richardson et al., Lifelong restriction of dietary branched-chain amino acids has sex-specific benefits for frailty and life span in mice, Nature Aging 2021).
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How does low BCAA metabolism lead to mitochondrial dysfunction/oocyte aging? Is it related to accumulation of amino acids in the cytosol and toxicity to mitochondria? (e.g. Hughes et al., Cysteine toxicity drives age-related mitochondrial decline by altering iron homeostasis, Cell 2020).
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Overall these data support the idea that oocytes are particularly vulnerable to conditions that drive aging, and conserved aging mechanisms in the soma and germline as well as across species.
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