HN user

azalemeth

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Medical physicist. Nerd. jack dot miller at physics dot org; DPhil [PhD] FInstP; MIPEM; AFHEA. Associate professor of medical physics & molecular imaging; Aarhus University, Denmark; Fellow by Resolution in Physics, St Hugh's College, University of Oxford, `U'K.

Google scholar page: https://scholar.google.co.uk/citations?user=LhYjunkAAAAJ&hl=en

Posts183
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www.gov.uk 5d ago

Profile: GRU cyber and hybrid threat operations

azalemeth
2pts0
petition.parliament.uk 16d ago

Do not ban children from using virtual private networks

azalemeth
1pts0
www.tsb.gc.ca 1mo ago

Marine Transportation Safety Investigation [Titan] Submersible Implosion [pdf]

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1pts0
www.etsi.org 1mo ago

GSM, UMTS, LTE and 5G Standard Protocols and Procedures for Lawful Interception [pdf]

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2pts0
www.gov.uk 1mo ago

Today is the last day of the UK's consultation on social media and VPNs

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3pts0
tom7.org 2mo ago

GradIEEEnt half decent – The hidden power of imprecise lines(2023) [pdf]

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www.theguardian.com 3mo ago

Peers vote to ban pornography depicting sex acts between stepfamily members

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54pts90
arstechnica.com 3mo ago

Apple begins age checks in the UK with latest iOS update

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6pts0
www.theregister.com 4mo ago

Microsoft Authenticator to nuke Entra creds on rooted and jailbroken phones

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31pts12
www.gov.uk 4mo ago

Open consultation: Growing up in the online world

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1pts0
www.theguardian.com 5mo ago

Police arresting 1000 paedophiles a month across the UK

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9pts8
arxiv.org 5mo ago

Biases in the Blind Spot: Detecting What LLMs Fail to Mention

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2pts0
petition.parliament.uk 5mo ago

Do not ban children from using virtual private networks

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4pts2
keirstarmer.substack.com 5mo ago

"Giving children the space to grow"

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3pts1
www.theverge.com 5mo ago

Grok is still undressing men

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5pts3
neodyme.io 6mo ago

Diving into the Depths of Widevine L3

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2pts0
christopher-parsons.com 6mo ago

NSA Network Shaping 101 [2007, Snowden leak] [pdf]

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1pts0
christopher-parsons.com 6mo ago

(2023) GCHQ [Sigint] Summaries

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1pts0
games.jmir.org 7mo ago

Games’ affordance of childlike wonder and reduced burnout risk in young adults

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168pts133
archive.org 9mo ago

'Sharps and flats': a [guide to] cheating at games of chance and skill (1894)

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1pts0
www.theregister.com 9mo ago

Microsoft 'illegally' tracked students via 365 Education, says data watchdog

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59pts12
www.blocked.org.uk 11mo ago

Online Safety Act – shutdowns and site blocks

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284pts302
www.bbc.co.uk 11mo ago

VPNs top App Store charts as Online Safety Act age checks kick in

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4pts0
arstechnica.com 1y ago

UK backing down on Apple encryption backdoor after pressure from US

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555pts422
cybernews.com 1y ago

Largest ever data leak exposes over 4B user records

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8pts0
www.resecurity.com 1y ago

DragonForce Ransomware – Reverse Engineering Malware Analysis

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2pts0
ia600100.us.archive.org 1y ago

EP-3E Collision: Cryptologic Damage Assessment and Incident Review (2001) [pdf]

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4pts0
pulls.name 1y ago

Mullvad DAITA v1 and v2 defenses

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1pts0
news.ycombinator.com 1y ago

The Home Office's Response to my questions about the removal of Apple's ADP

azalemeth
8pts3
www.phoronix.com 1y ago

AMD Ryzen 9 9950X3D Delivers Excellent Performance for Linux Developers

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19pts1
Blender 5.2 LTS 4 days ago

I "grew up" using Cinema 4D. Likewise I just find that the UI of blender is for whatever reason _incredibly_ not intuitive for me. I also don't really like the fact that everything is a youtube video nowadays; I guess it's easier to monetise for the kind people who make tutorials but when I learnt 3D modelling as a teenager (in ~2005 with a desire for 3D printing!) C4D just intuitively "clicked" and they had a lot of hugely detailed, technical information with a lot of physics in it. One of my dad's friends had a license for it, and I was somehow able to just internalise its various primitives and object based workflow.

I've tried many times to get to grips with Blender but for whatever reason I've found doing the simplest things very tiring. If there's a big, illustrated PDF manual out there for a recent version, I'd love to know of a link to it...or even better yet a conversion guide from C4D (!)

A nanosecond? The speed of sound at sea level in dry air is approximately 330m/s. So at say 3.3 kHz, the rough logarithmic middle of the audible spectrum, K=2π/lambda is 2π/0.1 m=20 π rad/m. A phase difference from a source difference k. ∆r would therefore likely be far more easily resolved than that for many physical ∆rs then, no?

I'm a medical physicist. I literally haven't been able to get Fable to answer a question I have written -- all of my work is verboten. I have however asked Claude Code (opus 4.8) to ultracode "a Fable oracle that <deals with the high level difficult problems> in a digraphed, clean content, isolated environment with a minimally scoped working codebase. Ask the model at the start and the end to report exactly what its version string is. If it is not claude-fable-5, stop the agent and refine the prompt until this changes"

It burns through tokens like anything but apparently Claude is much better at prompting Claude than I am.

Would I pay for it? God no. I'm still smarter than I am and it just will not work on my actual problems.

For what it is worth, your site has been blocked by the UK's national cyber security centre on my current connection:

    This site may be associated with malicious activity or malware.
     Access to this site has been blocked by the Protective DNS Service
    Site: wtf.korridzy.com
    Please contact your local Network Administrator or IT support if you require further assistance


    Look up this site on Cloudflare Radar [1] for more information.
I would wear this as a badge of pride!

[1] https://radar.cloudflare.com/domains/domain/wtf.korridzy.com

I'm an international prizewinning academic likely to reduce my hours due to health concerns but very interested in fun, physics-heavy problems and out-of-bag collaborations.

Location: UK

Remote: Yes

Willing to relocate: No

Technologies: Medical Imaging, Magnetic Resonance and biomedical research in general -- and in a more nerdy context, HPC, MPI, C, C++, R, a bit of python (though, frankly, I do not like it) /tensorflow, and bash / mathematica / matlab. Not popular, I know. Oh, and LaTeX. I'll write a shopping list in LaTeX. You probably don't want that.

Website: Have a glance at https://scholar.google.co.uk/citations?user=LhYjunkAAAAJ for a flavour of the many random things I've worked on

Email: See my HN Userpage.

I haven't bought a single Sony product since then. I used to have a Sony walkman, clock radio, buy classical Sony CDs (or their sub brands), etc, nearly got an original PlayStation.

I wrote a letter to them after the rootkit fiasco saying they've lost a consumer for life. Didn't get a real response. Wrote to them last anti DRM day. Didn't get a response.

Really, this is the only power one has in capitalism -- don't buy their products.

Lift Challenge 1 month ago

I know you're joking, but changes in isotopes mildly affect reduced mass and hence enzyme kinetics. Maize and other C4 plants already preferentially enrich themselves with 13C [0-3] which occasionally buggers up metabolomic experiments. Famously, a few drugs use 2H rather than natural abundance H typically in order to exploit a kinetic isotopic effect and get a better Km in their binding pocket [4].

[0] https://en.wikipedia.org/wiki/Fractionation_of_carbon_isotop... [1] https://pubmed.ncbi.nlm.nih.gov/7577891/ [2] https://pubmed.ncbi.nlm.nih.gov/1734681/ [3] https://en.wikipedia.org/wiki/List_of_C4_plants [4] https://en.wikipedia.org/wiki/Deuterated_drug#Examples

I think it's worth mentioning the likes of tor, lokinet, yggdrasil, i2p, freenet and maybe other "esoteric" forms of networking like vless or v2ray. If they really do put significant barriers in the way of nerd-to-nerd communication, other metrics will only grow really.

At the moment, it's network effects that are the biggest deterrent to using these technologies -- at the moment I don't want to browse eepsites or .loki domains at the moment although I think the technology is interesting -- because the use cases are "normal" consensual porn, horrific illegal porn / CSAM, illegal drugs, and organised crime, none of which are me. If they manage to drive even 0.1% of the population towards talking about, say, cat pictures, unreal tournament matches (gamer-to-gamer communication is itself banned under these proposals without age verification!), or something that normal nerds would like, then (a) the popularity of these methods would explode; (b) the ability of law enforcement to surveil them as proxies for genuinely bad stuff would be significantly hampered; and (c) I think the net result is that more people would be exposed tangentially at least to criminality than before.

It's a shockingly short-sighted proposal. I wrote to my MP about it; her response was basically "We have a difference of opinion".

Academia is the most relevant, toxic example that I can think of. Be horrible to others on a short term contract (grad students, postdocs) and break them whilst extracting maximum value -- get more papers, more grants written -- more money -- success.

Be nice, think about hard problems for a long period of time, only speak up when you have something positive to contribute -- be labelled an underperforming academic and managed into obscurity.

A great example of this is Peter Higgs, who famously said that he'd be unemployed pretty quickly in the academia of 2013. [0]

[0] https://www.theguardian.com/science/2013/dec/06/peter-higgs-...

Claude Fable 5 1 month ago

I saw 'medical physicist' and wondered what you do. Thank you for 'a bit more context', I care! Very interesting stuff. Did you attend medical school + a physics program?

That's a whole separate long answer. I'm not a qualified doctor (and nor would I claim to be), but after a masters' degree in particle physics I moved into an explicitly interdisciplinary training programme that led to a doctorate and at other places in the country I did it in, a separate MPhil. During that initial year I spent a fair amount of time in the dissection room, learning anatomy, as well as most of the first three years (the foundational, preclinical part) of a medical degree combined into one (which contained lots of molecular biology, frankly). My final doctorate was between the departments of condensed matter physics (nominally my awarding institution), biochemistry, radiation oncology, and "the department of physiology anatomy and genetics", which is basically preclinical medicine. The people I work with are 50/50 recovering engineers or physicists, and qualified clinical medics who are trying to learn things like perturbation theory in their time off…

"it just works", completely by luck What does your validation function look like for this? Whenever stuff "just works" for me I get a little nervous until I determine why.

Ah. I do know why: the relevant Damköhler numbers [0] are either very small (chemistry is much quicker than flow) or large (flow is much quicker than chemistry). So the approximations I am building in are justified and an awkward middle region is excluded; we also are only interested in small concentrations in a carrier fluid (e.g. blood, lymph) where the presence or absence of the species in question does not change its rheology.

I am lucky because we have evolved this way. If our circulatory system and its approach to metabolism was more similar to e.g. a reacting polymer foam ("can of expanding foam") which completely consumes its reactants as it goes, this implicit Lagrangian approach would likely not work.

[0] https://en.wikipedia.org/wiki/Damk%C3%B6hler_numbers

Claude Fable 5 1 month ago

Honestly for a "side project" Opus has been fantastic for me writing a hybrid simulation framework that prior to large scale code generation would have been a matter of years (and writing a grant, assembling a team, etc – in order to do it "properly"). I've had a bit of help with a grad student and I hacking together on a project that is basically "please merge the following GPL codebases and different areas of physics into one coherent environment". I've given Opus validated codes in disparate languages (julia, python, C) and asked for aspects of various algorithms as an extension module to a large chunk of C and C++ code that is a monte carlo simulator that has been around since 2004.

A bit more context if you care: it's a meso-scale, physiological simulation environment of "particles" that carry nuclear spin, can move in 3D space, and (should they interact with each other or their environment) undergo chemical kinetics. The idea is to simulate molecules within e.g. organs or blood vessels within a person in an MRI scanner, with the motion of the particles dominated by the Navier Stokes equations, but here solved in a Lagrangian (rather than Eulerian) framework by smoothed particle hydrodynamics.

The fact that particles carry nuclear spin means that we can solve the (semiclassical) Bloch equations and by using a python plugin module import exactly the physical MRI scanner would do (in pulseq format) and be able to predict what signal the machine would record – e.g. there's a whole world of cardiac or neurological flow imaging work done in the context of nasty diseases like stroke or myocardial infarction – which has a bunch of physical artefacts behind it. I'm trying to make a simulation framework that can take in realistic patient geometries and act as a 'data generating process' because if we do it right the various physical artefacts that the machine records are reproduced, surprisingly accurately. Of course you also know the ground truth of where the particles are. I'm specifically interested in a weird technique (which I did my PhD in and you can read an article all about here: [0]) called dynamic nuclear polarisation, where specific spin states of molecules such as [1-13C]pyruvate are injected essentially out of thermodynamic equilibrium and act as short-lived tracers of metabolism – again highly altered in disease. The signal we record is a strong function of the physics of what you told the machine to do, the spatial constraints and environment of the patient's body, and the chemical kinetics of the patients' biochemistry (the latter two are usually what we're interested in).

Getting them to do chemistry as well as act as a "simple" tracer is more involved, because in the Lagrangian framework the number of particles is ≈ the spatial resolution of your simulation. That's fine if you're simulating water, but if you're simulating something that reacts concentration is not scale invariant (if you want to keep the interpretability of the rate constants). I've worked out an analytic set of scaling rules around this and fortunately for my application environments and length scales "it just works", completely by luck.

I've used Claude to port various SPH algorithms and boundary condition handling ideas (which are absolutely critical and highly not obvious – we have leaky walls in some places, and e.g. LCR / circuit theory models of the microcirculation to plug in) and it's been a godsend. But I'm running into its limitations constantly. It both confidently makes shit up, claims it is mathematically justified and when the resulting simulation explodes says "I apologise; I lied above" (!) or "I apologise; I am wrong" and I periodically have to yell at it to try to do something more productive.

The real hope is that this simulation environment would be both generally useful for basically anyone doing flow MRI, and help our basic scientific understanding of what we're measuring (the technique is in many hospitals!) but also be able to produce meaningful synthetic training data for image reconstruction algorithms later on. It'll end up permissively licensed (all of the "starting" codebases have compatible OSS licenses, and we're releasing our contributions similarly).

I really hoped that Fable would be better at this sort of work. Occasionally, relating to my work DNP [1], I have need to talk about proper nuclear physics and I have seen Opus's chat interface write a wall of text (e.g. talking about photonuclear reactions and cross section differences in millibarn) and then just delete it all. Support have told me that yes, I've hit the nuclear filter and, well, tough shit, basically.

I wrote a version of the above to them yesterday, and just got the most boilerplate response that I've yet to test:

    Thanks for reaching out to Anthropic Support.
   
       We're sorry to hear of the issue that you're running into with accessing Fable 5. I'm happy to say the issue has now been resolved and you should be able to access the model within Claude.

    I'll close this case out for now, but please feel free to reach back out to us here if you have any follow up questions or concerns or if you're still in need of assistance. We'll be happy to help.
which doesn't fill me with hope...

[0] https://physicsworld.com/a/dynamic-nuclear-polarization-how-... [an "accessible" article] [1] https://www.science.org/doi/pdf/10.1126/sciadv.adz4334

Claude Fable 5 1 month ago

I genuinely can't use Fable. I'm a medical physicist. I use the word nuclear a lot. Opus is fine (well, 99% of the time - I've certainly hit the CBRN filters a few times and even been invited to email anthropic about the false positives).

Fable has literally refused to work on any of my problems (even those about fluid dynamics!) and just tells me that I'm violating anthropic's AUP. I've reached out to their support and don't expect to hear anything sensible back. One thing I do look forward to though is OpenAI offering an equivalent model but with less safeguards...

I'm a medical physicist. I use the word nuclear a lot. Opus is fine (well, 99% of the time - I've certainly hit the CBRN filters a few times and even been invited to email anthropic about the false positives).

Fable has literally refused to work on any of my problems (even those about fluid dynamics!) and just tells me that I'm violating anthropic's AUP.

This statistic comes from here -- https://www.gov.uk/government/publications/parental-support-... -- a preliminary analysis of the consultation. The headline statement is:

    "Of the parents and carers of children aged 21 and under who responded to Question 12 on the full-length version of the consultation, 89% supported “a legal requirement for social media services to have a minimum age of access”." 
However, what the government (and the media) are _NOT_ reporting is that the consultation also paid an independent firm to undertake a nationally representative survey of adults in the general population. The above document acknowledges this itself, by stating:
    Caveats and limitations

    Users should note the following when interpreting these results: 
    Self-selecting sample

    The consultation was open to anyone who chose to respond. The results reflect the views of parents and carers who were motivated to take part, and are not representative of parents and carers nationally. As with any open public consultation, respondents may differ systematically from the wider population in their views and characteristics. 
    Question routing

    These questions were only presented to respondents who wanted to respond to Chapter 2: Interventions for safer, more positive experiences. All questions in this section were optional. Finally, Question 13 was only presented to respondents who answered “Yes” to Question 12 (i.e. those who supported a legal requirement for a minimum age of access in principle). The 96% figure therefore relates to the level of agreement with a minimum age of at least 16 among those parents and carers who opted to respond to this Chapter and already supported some form of minimum age requirement. It does not represent the views of all consultation respondents, nor all parents and carers who responded.
    Full consultation only

    The figures relate only to the full-length version of the consultation, not the streamlined parents’ and children’s consultations.
Status of results
   These figures should be treated as provisional. A comprehensive analysis of all consultation responses will be published separately.consultation, respondents may differ systematically from the wider population in their views and characteristic
So, it's 90% of 9499 parents who specifically went out of their way to respond to a consultation widely heralded as being predetermined and about blocking access to social media. For context, in the 2021 census (massively disrupted by covid) there were 11.5 million schoolchildren and full-time students whose parents were the target of the survey.

The representative study isn't published yet. The provisional headline 90% number is.

[1] https://www.ons.gov.uk/peoplepopulationandcommunity/educatio...

I'm someone with an academic background who is always interested in new collaborations and interesting problems to explore.

Location: Mostly in Oxford, UK Remote: Yes Willing: no Technologies: Prize-winning physicist and physical scientist. Deeply familiar with maths and physics and statistical inference, in a biomedical context. I've worked on everything from pythons to potatoes (and from assembly code to, well, python). Google Scholar is probably a better judge of my outputs than a strict CV; https://scholar.google.co.uk/citations?hl=en&user=LhYjunkAAA... Email: in profile.

Exactly. A decent digital communication, spectrum or vector network analyser from the likes of Keysight (AKA HP or Agilent) or R&S is crazy money – many thousands.

Compared to any piece of "proper" test and measurement equipment even if Flipper 1 is $1k it's a steal, for example. Heck, the last thing I put on a grant application was a 220 GHz AWG that was something like $1.5m. Admittedly quite different from a single m2 plugin socket but a 1 GHz spectrum analyser starts at $2.4k and everything fancier is "price on application" [0].

I realise this is not the same piece of kit as Flipper One, but with the right daughter boards, hackability, and <s>graduate student</s> labour I imagine you could do a lot (I am interested in RF at <1 GHz for NMR reasons as well as electronic Larmor frequencies at ~100 GHz frequencies). Their SDR daughter boards are designed for communication but there's a whole world of academic nerds who do weird things and would love a genuinely open, hackable broadband SDR (they exist, with limitations! I have a lime SDR somewhere…)

[0] https://www.rohde-schwarz.com/us/products/test-and-measureme...

This looks flippin' amazing, but also like the definition of project scope creep. I imagine it will be brilliant, unaffordable, surprisingly cheap, terrible and awesome (in both senses of the word) all at the same time. 3GPP really needs a light shining through it.

I sincerely hope I work out a way of getting someone else to buy the thing for me. And the push towards all in-tree source is fantastic. Genuinely impressed.

It is perhaps worth highlighting that Mozilla has done this in response to a specific UK government consultation [1] all about "growing up in the online world", which has, buried about 30 pages deep, a specific question about age-gating VPNs and similar technologies.

As far as I can tell, there is no requirement to be a UK citizen to answer this – if you are, were, or could be resident in the UK I urge you to fill it out and help provide a voice of reason...

[1] https://www.gov.uk/government/consultations/growing-up-in-th...

You really do provide a reassuring, good service -- thank you.

It's also worth stating that the client (including the cli client -- which, with a bit of work, you can get running in most situations where you'd use native wireguard) by default has a key rotation interval of I think 72 hours.

`mullvad tunnel get` will show it and `mullvad tunnel set rotation-interval <hours>` will change it. This is the preferred mitigation method of the post.

I personally don't mind having a pseudo-static IP (some other suppliers offer a static IPv4 as a feature!) as I wish to prevent network-level snooping from my ISP and governments. It's also worth stating that I think having a smaller IP space is an advantage for a privacy VPN: there are more potential users acting behind any given externally visible IP. Combined with technologies like DAITA (which effectively adds chaff to the tunnel) and multi-hop entrances and I personally think that this service really does plausibly make harder the life of those who snoop netflows all day.

I really have an odd nostalgia for longwave. I grew up listening to radio 4 lw in the middle of nowhere and it was the only station that had consistently good signal. The fact that it carried somewhere out into the Atlantic blew my mind!

I understand it's closing because some insanely high powered, insanely expensive valve or thyristor or triac or generic high power "niche" component is reaching the end of its life, but I will be sad nevertheless when this goes.

DAB doesn't work reliably with my phone charging in the same room...

I distinctly remember being an 8 year old in primary school and not being believed by a teacher that tungsten existed. I was told I must be wrong about the density of this metal being higher than lead and unless I could find a book to prove it I should shut up about it. In reality I'd been to a museum and learnt all about wonderful wulfram and probably just must have been insufferable.

Wikipedia is a godsend.

Very ironically I get this error trying to read the article:

403 ERROR The request could not be satisfied. Request blocked. We can't connect to the server for this app or website at this time. There might be too much traffic or a configuration error. Try again later, or contact the app or website owner. If you provide content to customers through CloudFront, you can find steps to troubleshoot and help prevent this error by reviewing the CloudFront documentation. Generated by cloudfront (CloudFront)

Qui blockat blockodiodes? Cloudfare, it turns out....

Ubuntu 26.04 3 months ago

I know that the interim releases had issues with zfs and trying to update gave the message "Sorry, cannot upgrade this system to 25.04 right now System freezes have been observed on upgrades to 25.04 with ZFS enabled. Please see https://wiki.ubuntu.com/PluckyPuffin/ReleaseNotes for more information. "

The release notes don't seem to mention zfs. I hope these issues have been fixed?