
David J Glass MD
@davidjglassMD
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Book: Experimental Design for Biologists. Journal: Skeletal Muscle. Focus areas: Aging; Muscle. Works for a biotech company; views are mine.
New York
Joined December 2013
Catch up on FSHD: .DUX4 at 25: how it emerged from “junk DNA” to become the cause of facioscapulohumeral muscular dystrophy.
skeletalmusclejournal.biomedcentral.com
Double Homeobox 4 (DUX4) is a potent transcription factor encoded by a retrogene mapped in D4Z4 repeated elements on chromosome 4q35. DUX4 has emerged as pivotal in the pathomechanisms of facioscap...
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Don't write something in a review that you wouldn't appreciate reading from a reviewer. I don't care if you've been traumatized by prior hostile reviewers. Be better.
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The Reverend Bayes' original example was figuring out how close a billiard ball was to a line on the pool table. You can posit multiple potential possibilities, assigning priors to each; the data updates your priors, getting you to reality. There's no binary "yes/no" involved.
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Scientists who argue that aging isn't programmed need to explain how you get a 6-fold difference in lifespan between rats and squirrels (both rodents; both the same size, etc) without programming. Or consider budgies vs african grey parrots - 5 to 6 fold difference in lifespan.
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Another feature of a query-based experimental framework is that it eliminates the "positive vs negative" data binary. If your data answers the question you've posed, it's simply data - neither positive nor negative. This significantly decreases the incentive to cherry-pick.
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RT @davidjglassMD: If you frame an experiment with a hypothesis or expectation, and then set out to test that claim, you're always at risk….
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As to "why do we age?" I don't find "why" questions very helpful. The fact is we do age, in a reproducible manner. If aging weren't programmed, we wouldn't see reproducible gene expression changes at specific times throughtout life. We'd break down randomly - like a car.
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I guess the most straightforward evidence that aging is programmed is that related species have different, but reproducible lifespans. Rats live around 2.5 years. Squirrels can live 15 years. Both are rodents, similarly sized, but there's a reproducible 6x difference in lifespan.
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Here is one thing I think I understand about aging, which is pretty amazing: aging is programmed. We've performed aging gene signatures - assessing changes in gene expression with age via RNAseq - and you see the same changes happening at the same time in the same tissues.
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Advantages to the MD degree: you know when you'll finish. You're judged on things which are entirely under your control. You get a liberal arts education in pathology. Disadvantage: learning medicine doesn't prepare you to be a scientist; you still need that training.
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One straightforard way to demonstrate reproducibility is have someone else in your lab repeat the experiment. Then publish both experiments. If there's a range of results, publish the range. It's a rare result that can be found every time; show the probability of the result.
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PhD students rarely choose their own projects, so for them to have to take a long time to graduate is unfair, as is judging them on project success. A PhD should be like an MD: 4 year term; learn method, process and necessary background facts. Choose your project as a postdoc.
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My top scientists of all time:.Archimedes, Hippocrates, Pythagorus, Euclid, Galen, Vesalius, Copernicus, Galileo, Bacon, Harvey, Redi, Hooke, Newton, Bayes, Galvani, Pasteur, Venn, Darwin, Mendel, Einstein, Curie, Bohr, Fleming, Turing, Franklin, Meselsohn & Stahl, Baltimore.
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Just a reminder as to the mechanism of action of Bimagrumab, and it's origins ;-). An Antibody Blocking Activin Type II Receptors Induces Strong Skeletal Muscle Hypertrophy and Protects from Atrophy.
pmc.ncbi.nlm.nih.gov
The myostatin/activin type II receptor (ActRII) pathway has been identified to be critical in regulating skeletal muscle size. Several other ligands, including GDF11 and the activins, signal through...
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No one reads your paper more closely than your biggest competitor. Therefore you should work hard to make sure it's bullet-proof, no?.
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Is taurine an aging biomarker? Apparently not. Do taurine levels correlate with any sort of health status? Apparently not. Were prior high-profile claims as to the benefits of taurine reproducible? Apparently they were not.
science.org
Low circulating taurine concentrations have been proposed as a driver of the aging process. We found that circulating taurine concentrations increased or remained unchanged with age in three geogra...
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Federal Reserve Chair Jerome Powell gave the commencement address at Princeton yesterday. Among his remarks:. “At the end of the day, your integrity is all you have. Guard it carefully.”.
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GDF8 and activin A are the key negative regulators of muscle mass in postmenopausal females: a randomized phase I trial.
nature.com
Nature Communications - GDF8 and activin A are the dominant negative regulators of muscle mass in animal models. This two-part, randomized, placebo-controlled Phase 1 trial suggests that GDF8 and...
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