TWiV 878: Shape matters sometimes

March 20, 2022

TWiV revisits chronic wasting disease of cervids and the ability of the prions to infect meadow voles and raccoons, and the suggestion that stochastic assembly of influenza virus particles may play a role in phenotypic diversity.

Hosts: Vincent Racaniello, Dickson Despommier, Rich Condit, and Amy Rosenfeld

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Download TWiV 878 (75 MB .mp3, 124 min)
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RichSearching for the origin of the smallpox vaccine: Edward Jenner and his little-known horsepox hypothesis
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Intro music is by Ronald Jenkees

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6 comments on “TWiV 878: Shape matters sometimes

  1. [A clarifying edit of my YouTube comments] I understood that Prion Disease is limited to the CNS. It does not somehow migrate into the tissues because it *has no vector* per se, as it is a misfolding of a native protein found *in the CNS* initiated by another identical or nearly identical protein which has found this more energetically stable conformation thus having the thermodynamic potential energy to pass on, in the constant probabilistic variability found at the atomic/molecular level, [characteristic at this scale]. The entire critter, deer,sheep,cow is not “infective,” just it’s CNS tissue.
    The origin of CJD in humans came as I understand it, from using feed supplemented with products from *whole* cow/sheep carcasses including their CNS tissue. The meat becomes contaminated with this diseased CNS tissue during slaughter and preparation for humans. It is intuitively an Awful use of Offal . . 🙂 The evolutionary conservation of basic molecular structures, it seems, has lead to the interspecies transmission of *so-called* prion proteins which are just certain sequences of amino acids that can lead to energetically/conformationally unstable structures that happen to become more stable and resistant to denaturing via refolding, and are not the conformation that *initially* exits the ribosome during translation.
    The wasting/neurological symptoms result from a process I think seems alarmingly similar to Alzheimer’s disease [and many other rare, heritable mutations] in which a molecule achieves a configuration which evades normal cellular “disposal” machinery, thus accumulating in (CNS) tissue. To treat CJD/wasting disease as a vector-driven infectious disease seems similar to treating Alzheimer’s as an infectious disease of unknown etiology, ignoring the basic native molecular mechanism. Prion disease is fascinating because it evades our standard approach {via Koch, Pasteur, Lister} to transmissible disease, ignoring the native genetic component giving hidden vulnerability to novel causation. Long-COVID is teaching us that we must be careful not to misappropriate language which fortifies these assumptions about vector and host.

  2. LizinOregon Mar 20, 2022

    The answer to too many deer is to bring stop killing wolves and mountain lions and learn to live with them.

  3. A poetic reminder of human scientific frailty, written in 1784 by Alexander Pope:

    Essay on Man: Epistle 2
    Alexander Pope, 1734

    Know, then, thyself, presume not God to scan; The proper study of mankind is man.
    Placed on this isthmus of a middle state, A being darkly wise, and rudely great:
    With too much knowledge for the sceptic side, With too much weakness for the stoic’s pride,
    He hangs between; in doubt to act, or rest; In doubt to deem himself a god, or beast;
    In doubt his mind or body to prefer; Born but to die, and reasoning but to err;
    Alike in ignorance, his reason such, Whether he thinks too little, or too much:
    Chaos of thought and passion, all confused; Still by himself abused, or disabused;
    Created half to rise, and half to fall; Great lord of all things, yet a prey to all;
    Sole judge of truth, in endless error hurled: The glory, jest, and riddle of the world!

    Go, wondrous creature! mount where science guides, Go, measure earth, weigh air, and state the tides;
    Instruct the planets in what orbs to run, Correct old time, and regulate the sun;
    Go, soar with Plato to th’ empyreal sphere, To the first good, first perfect, and first fair;
    Or tread the mazy round his followers trod, And quitting sense call imitating God;
    As Eastern priests in giddy circles run, And turn their heads to imitate the sun.
    Go, teach Eternal Wisdom how to rule— Then drop into thyself, and be a fool!

    Superior beings, when of late they saw A mortal man unfold all Nature’s law,
    Admired such wisdom in an earthly shape And showed a Newton as we show an ape.

    Could he, whose rules the rapid comet bind, Describe or fix one movement of his mind?
    Who saw its fires here rise, and there descend, Explain his own beginning, or his end?
    Alas, what wonder! man’s superior part Unchecked may rise, and climb from art to art;
    But when his own great work is but begun, What reason weaves, by passion is undone.
    Trace Science, then, with Modesty thy guide; First strip off all her equipage of pride;
    Deduct what is but vanity or dress, Or learning’s luxury, or idleness;
    Or tricks to show the stretch of human brain, Mere curious pleasure, or ingenious pain;
    Expunge the whole, or lop th’ excrescent parts Of all our vices have created arts;
    Then see how little the remaining sum, Which served the past, and must the times to come!

    The URL is to avkurzgesagt video on YouTube, from a link you posted previously, regarding little lies told in the service of explaining the universe.

  4. Jason Mar 22, 2022

    A gut pile after field dressing a deer is not uncommon or unusual at all. It’s done so the meat doesn’t spoil or develop a bad taste. Yes, it’s often left right in the woods and scavengers clean it up.