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Cake day: August 4th, 2023

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  • modeler@lemmy.worldtovegan@lemmy.worldThat is not vegan.
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    6 days ago

    As an aside, oysters are not bivalves, they are brachiopods. Brachiopods do have a nervous system - some even have eyes.

    What’s the difference and how do you tell a brachiopod from a bivalve? It’s the plane of symmetry. In bivalves the plane of symmetry is where the shells (also known as valves) join. So bivalves have two identical shells. Whelks and razor shells are bivalves. Brachiopods also have two shells, but the shells are normally quite different. The oyster for example has one big concave shell and one small flat one on top. The big shell has a hole at the apex (just next to the hinge) and a root-like anchor grows from it to bind the brachiopod to the matrix on which it lives. Brachiopods have an axis of symmetry from this root/foot that vertically separates each shell into two mirrored parts.


  • This is true for only red and green loght detecting proteins (opsins) - the blue opsin gene is on chromosome 7.

    The red and green detecting proteins have an interesting history in humans.

    Fish, amphibians, lizards and birds have 4 different opsins: for red, green, yellow and blue colours. And the blue opsin sees up into the ultra-violet. Most animals can see waaaay more colours in the world than we (or any mammal) can. So what happened that makes mammal vision so poor?

    It’s thought that all mammals descend from one or a few species of nocturnal mammal that survived the catastrophe that wiped out the dinosaurs at the end of the Cretaceous. The colour detecting cells (the cones) need a lot of light compared to ones that see in black-and-white (the rods) and therefore nocturnal animals frequently lose cones in favour of the more sensitive rods for better night vision. The mammals that survived the Cretaceous extinction had also lost the green and yellow opsins while keeping red and blue - basically the two different ends of the light spectrum.

    Consequently today most mammals still have only 2 opsins so your cat or dog is red-green colourblind.

    Why do humans see green? Probably because our monkey forebears, who lived in trees and ate leaves, needed to distinguish red leaves and red fruit (visible to birds) from the green background.

    But how did we bring back the green opsin? A whole section of the X chromosome (where the red opsin is coded) got duplicated in a dna copying mistake and then there were two genes for red opsins. As there are different alleles (versions), they could be selected for independently and so one red opsin drifted up the spectrum to be specific for green. So our green opsin is a completely different gene to the green opsin in fish, birds, etc. This kind of evolution happens a lot which is why, for example, there are many families of similar hormones like testosterone and estrogen. And steroids too.





  • All junior devs should read OCs comment and really think about this.

    The issue is whether is_number() is performing a semantic language matter or checking whether the text input can be converted by the program to a number type.

    The former case - the semantic language test - is useful for chat based interactions, analysis of text (and ancient text - I love the cuneiform btw) and similar. In this mode, some applications don’t even have to be able to convert the text into eg binary (a ‘gazillion’ of something is quantifying it, but vaguely)

    The latter case (validating input) is useful where the input is controlled and users are supposed to enter numbers using a limited part of a standard keyboard. Clay tablets and triangular sticks are strictly excluded from this interface.

    Another example might be is_address(). Which of these are addresses? ‘10 Downing Street, London’, ‘193.168.1.1’, ‘Gettysberg’, ‘Sir/Madam’.

    To me this highlights that code is a lot less reusable between different projects/apps than it at first appears.




  • It is terribly sad - they must live in a world of hurt.

    However so many of these people actively try to hurt LGBTQ+ and trans people by inciting hate and changing laws to harm the non-straight. In particular they have been preaching that being gay/trans equates to being a child molester. This is horrific and needs to stop. Exposing the hypocrisy is essential to reducing the harm they are inflicting to real people right now



  • Ackshually they do this, not with cars but, with WW2 era prop planes.

    The Spitfire for example:

    The Merlin consumed an enormous volume of air at full power (equivalent to the volume of a single-decker bus per minute), and with the exhaust gases exiting at 1,300 mph (2,100 km/h) it was realised that useful thrust could be gained simply by angling the gases backwards instead of venting sideways.

    During tests, 70 pounds-force (310 N; 32 kgf) thrust at 300 mph (480 km/h), or roughly 70 hp (52 kW) was obtained, which increased the level maximum speed of the Spitfire by 10 mph (16 km/h) to 360 mph (580 km/h). The first versions of the ejector exhausts featured round outlets, while subsequent versions of the system used “fishtail” style outlets, which marginally increased thrust and reduced exhaust glare for night flying.

    From Wikipedia



  • You need at least two copies in two different places - places that will not burn down/explode/flood/collapse/be locked down by the police at the same time.

    An enterprise is going to be commissioning new computers or reformatting existing ones at least once per day. This means the bitlocker key list would need printouts at least every day in two places.

    Given the above, it’s easy to see that this process will fail from time to time, in ways like accicentally leaking a document with all these keys.






  • That was one of the original proposed mechanisms to explain how the (obviously false) autism was caused.

    But since then, since thiomersal was removed, other ‘causes’ and moral issues have been invented, including cells from abortions.

    The one that makes me laugh the most is that it’s terrible that the poor poor baby is exposed to so many illnesses (measles, mumps, rubella, polio, tetanus, notovirus, rotovirus and more) in such a short space of time, it’s no wonder the poor dear’s immune system is compromised. And then the same mother drops the kid off at daycare and exposes the poor dear to all those viruses and more - and live viruses at that.

    There is no bleeding logic, just feels. And they get so angry at the fake harm that medicine is causing, and simultaneously actually causing real harms to real people.