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sitharus

4,237 karmajoined hace 15 años

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sitharus
·hace 22 horas·discuss
Really? Where I live a patient is always able to refuse any medical procedure or treatment, unless they’re unconscious or otherwise mentally unable and the procedure is considered necessary to save their life. They certainly can opt for a non-ambulance transfer, though here it would be free even though a regular ambulance service typically isn’t.

Consent for treatment is a core principle of medical practice.
sitharus
·hace 8 días·discuss
I have a Polestar 2, 2022 model even so it's not fresh off the lot.

CarPlay navigation shows on the instrument cluster. The speed, state of charge, etc all move to the side so the map is right in the middle for quick viewing. Then the infotainment screen can show music or the tiled music/navigation view that CarPlay supports.

Basic music controls are on the steering wheel of course, readily accessible.

The lack of multitouch is slightly annoying, but it's not something I ever use. If I ever can't see what I need on the navigation I simply look outside for the road signs, which still exist.
sitharus
·hace 28 días·discuss
A lack of wear components.

A permanent magnet motor uses permanent magnets on the rotor, but an electrically excited synchronous motor has an electromagnet on the rotor. This requires a rotating electrical contact which has normally been made with slip rings and carbon brushes. These wear over time and need replacement.

Most large electric generators are externally excited synchronous generators using carbon slip rings, so it's a well understood field.

This can be made contactless using inductive coupling and a rectifier - since inductive coupling needs AC but the excitation coil needs DC - at the expense of some efficiency.

You can see the efficiency difference - Renault claim 92% efficiency but permanent magnet motor EVs have touted efficiency over 95% in the motor.
sitharus
·hace 2 meses·discuss
Structural colour works by destructive interference of reflected light. It requires the light to be scattered for this effect, so light travelling through at 90° won't be affected.

On the image in the article you can still see a trace of the image on the active screen from indirect light.
sitharus
·hace 2 meses·discuss
Higher quality video https://www.youtube.com/watch?v=EdoLjsp5hkM, you can see the landing gear just after 8 seconds for one frame.
sitharus
·hace 2 meses·discuss
The notification contents are sent over secure channels but are not end-to-end encrypted.

You can add additional data to the payload and have a helper app decrypt on the device when a notification is received.
sitharus
·hace 2 meses·discuss
When it was developed it was assumed that the cost of cellular equipment and, in some countries, the regulatory hurdles required to get authorisation to purchase radio transmitters that operate on licensed bands would make it almost impossible to do this.

I worked in a company that had a base station emulator in their testing lab in 2008. I can’t recall the cost but it was well over $10,000 and only worked with direct antenna coupling, it couldn’t broadcast.

Now we have software defined radios.
sitharus
·hace 3 meses·discuss
That’s not how it works. Not on iOS anyway.

For a standard notification the content of that notification is sent through the push notification servers. This includes the title, text, icon, grouping, and sound presets to use. The majority of user-visible notifications are sent this way - the app on the device does not run.

That allows the OS to display your notification without ever running the app, which saves limited resources on the phone. Originally this was the only option, a push notification couldn’t start your app.

These days an app can also register a notification extension which is a standalone program that can modify the incoming notification. It has 30 seconds to do whatever it needs to, though you need to be careful with RAM use or the OS will kill the process and present the notification unaltered. Generally you’d put something generic in the push as a fallback.

There’s also background notifications. These let the app run for 30 seconds and the app can post a local notification during this time, but they’re not guaranteed to be delivered. The OS can decide the system doesn’t have the resources and defer or drop them, or terminate the app before it’s finished if the ram is needed elsewhere.

There are some other special cases depending on what your app does.
sitharus
·hace 3 meses·discuss
With medicine both can be true, the response depends on so many factors in your body. Same way that for some people, particularly those with ADHD, taking stimulants can make them sleepy.
sitharus
·hace 3 meses·discuss
> but it does absolutely nothing with actual pain

Neither paracetamol nor ibuprofen work by blocking pain. Depending on the type of pain and your physiology it can range from really effective to not at all.

I only take paracetamol, it works better than both ibuprofen and opioids for me. I know other people who have the exact opposite experience. There’s no absolute here.
sitharus
·hace 3 meses·discuss
It’ll depend on how well grounded you are compared to how well grounded the laptop is, where it’s touching your body, and your sensitivity to electricity which varies.
sitharus
·hace 3 meses·discuss
They can’t, it’s caused by the capacitors required to suppress electromagnetic interference caused by the switch-mode power supply. These allow a very very tiny amount of current to leak through from the mains side, which is then capacitively coupled to the metal case (IIRC Apple do not connect the case to power negative) reducing it further, but it’s enough for humans to sense it.

It can be avoided by using a grounded power supply, but because there are large countries that have ungrounded outlets in common use the most designs are ungrounded.
sitharus
·hace 3 meses·discuss
Interesting, those are problems I don't have, I guess due to my work and workflow.

Command-` works for window switching as I expect, probably simply due to being used to it so I know exactly how It works.

Window positioning is an interesting one. I can't stand windows being positioned through tools, I stack them like you would with papers and shuffle through so the edge overlap is really important. Probably showing my age there!

And I never use the dock. Spotlight gets me everything I'd need from there.
sitharus
·hace 3 meses·discuss
What do you find missing from macOS keyboard navigation?

I've been using macs since the 90s so I'm quite used to it, so I'd love to know what I've been missing out on.
sitharus
·hace 4 meses·discuss
often we're told to add Google XSS-as-a-serv.. I mean Tag Manager, then the non-tech people in Marketing go ham without a care in the world beyond their metrics. Can't blame them, it's what they're measured on.

Marketing and managers should be restricted as well, because managers set the priorities.
sitharus
·hace 4 meses·discuss
1.1ng is a very small amount, but the effect is really not that well understood. It’s definitely something we should minimise.

However it’s not a dangerous dose, it’s just the dose that produces detectable changes and we can detect really really small changes. The toxic dose is around 4g/kg body weight. So an average adult would need to consume over 300 grams of pure BPA to be poisoned by it.

Of course the answer is to use non-plastic containers, though the most common plastic used for food (PET - milk bottles, most soft drinks etc) don’t contain any BPA. It’s the reusable ones that do.

I have glass containers for food, though I do still use plastic ones for short term storage for things I won’t heat. Honestly this seems like the best answer, metal, wood and glass if you can.
sitharus
·hace 4 meses·discuss
It's hard to define what 'safe' is.

The research is kind of hazy. Bisphenol-A has been shown to be a very very weak estrogen when measuring receptor binding affinity (about 37,000 times lower than human estrogen https://pmc.ncbi.nlm.nih.gov/articles/PMC2774166/#sec2), but has also been shown to be a potent stimulator in vitro for specific cell types (https://pubmed.ncbi.nlm.nih.gov/22227557/).

The lowest concentration of BPA that's been shown to be estrogenic according the second article is 0.1pMol/L which is around 230 picograms per litre of blood, or 1.1ng total for an average adult.

BPA's biological half life in humans is up to two to five hours depending on a range of factors (https://pmc.ncbi.nlm.nih.gov/articles/PMC2685842/), so taking the worst case you'd need to be continually exposed to around 2.5ng of BPA over a day.

So 'safe' as defined right now would be keeping the absorption below that 2.5ng per day threshold.

I don't know how how much BPA in plastics can transfer out per day, the research I've seen seems to indicate that unless it's a food container it's pretty minimal but I don't know enough to evaluate the quality of that research.

Your skin is also a pretty good barrier so only around 2.2% of any BPA on your skin can pass through in an ideal situation, so absorption from non-food sources is much lower (https://pmc.ncbi.nlm.nih.gov/articles/PMC9210257/)

The other problem is what do they replace BPA with? To be safer it would need at least as well studied as BPA, but often it seems like the 'safer' options are just not very well studied yet and could actually be worse.
sitharus
·hace 4 meses·discuss
If I recall my lectures, which were 20odd years ago now.

CISC ISAs were historically designed for humans writing assembly so they have single instructions with complex behaviour and consequently very high instruction density.

RISC was designed to eliminate the complex decoding logic and replace it with compiler logic, using higher throughput from the much reduced decoding logic (or in some cases no decoding at all) to offset the increased number of instructions. Also the transistors that were used for decoding could be used for additional ALUs to increase parallelism.

So RISC by its nature is more verbose.

Does the tradeoff still make sense? Depends who you ask.
sitharus
·hace 4 meses·discuss
The main distinction now is RISC-descended designs use a load-modify-store instruction set with all ALU functions being register-register, and consequently have a lot more (visible) registers than CISC-descended ISAs (mostly just x86 really).

Historically RISC instructions were 1:1 with CPU operations, in theory allowing the compiler to better optimise logic, but this isn't really true anymore. High performance ARM CPUs use µOPs and macro-op fusion, though not to the extent of x86 CPUs.

This document from ARM has some details on how they use micro-ops, https://developer.arm.com/documentation/102160/latest
sitharus
·hace 4 meses·discuss
A bit more reading shows there's a three instruction general case version for 32-bit additions on the 64-bit RISC-V ISA. I'm not familiar with RISC-V assembly and they didn't provide an example, but I _think_ it's as easy as this since 64-bit add wouldn't match the 32-bit overflowed add.

  add t0, t1, t2
  addw t3, t1, t2
  bne t0, t3, overflow