this is bbc news. the headlines: ukraine's president zelensky has urged europe to remain united in the face of russia's use of energy as a weapon. his wife has told the bbc the economic impact of the war is tough on ukraine's allies but ukranians are counting casualties rather than pennies. donald trump has accused joe biden of being the real enemy of the state, days after the president branded him a threat to american democracy. the former us president was holding a rally in pennsylvania, the first since the fbi raided his mar—a—lago residence, in florida. nasa has called off the planned launch of the artemis mission to the moon for the second time in a week.

the lift—off of the giant rocket was postponed after the discovery of a much larger fuel leak, than the one that prevented the first launch. now on bbc news, click. this week we are at the hospital that's using ai to try and cut waiting times for surgery. we are all at sea to see if sailing can go solar, we are finding our funny at the fringe festival to ask whether tiktok comedians can make it on stage. there is so much scope for error. and there's so much stuff

that's not in our control. on tiktok it is actually all in our control. and talking of control, we'll see how trying to track the twitter bots is no laughing matter... i said no laughing matter...oh, never mind. you are back, we're back, everybody is back, and this august so was the edinburgh festival, the world—famous celebration of the arts that takes over the city the whole month. it is a melting pot of theatre, music, dance and opera, and on the side, as its name suggests, is the edinburgh fringe. please, neverspeak to me again... filled with experimental performance, innovative shows and, my favourite, comedy. one of the beautiful things about the fringe is that it takes over loads of venues in the city, including this one, the university of edinburgh's old medical school. and before we get stuck

into the comedy, we are going to talk about medicine, specifically medical waiting times. now, if you're waiting for surgery, it can feel like an eternity and we all know waiting times are longer than anyone would want but one nhs trust in england is trailing an artificial intelligence that might be able to manage waiting lists better and ultimately bring down waiting times. marc cieslak has been to find out more. lorna ashburn has been suffering from hip pain for three years. essentially what this is saying is that, because of your background, there is a medium risk of developing what we would consider post—operative complication. the consultation occurring here uses a new ai system which helps determine the level of risk lorna will be exposed to by undergoing surgery. i have arthritis in both hips, both knees. i am struggling. i've actually had

to give up myjob. we saw the cardiovascular history and the smoking history and the consequences of smoking were the biggest determinants of your outcome from developing a risk post—operatively. hopefully i'm getting a hip replacement which will take away the pain. i want to be more active and get back into walking my dog longer, things like that. lorna is being treated at the wansbeck hospital in northumberland. she has been told it is a five—month wait for her surgery. this new ai model has been developed by orthopaedic surgeonsjustin green and mike reed nat northumbria healthca re nhs trust. it measures risk associated with surgery. traditionally, factors such as previous heart attacks and strokes present significant risk factors for somebody about to undergo surgery. the ai model takes into account 220 different factors to work

out each individual patient�*s risk. the patient comes for an operation, they bring with them a lifetime of medical history as well. that is really important to the patient but it takes a lot of understanding, from a clinical perspective, in terms of how that influences the outcome of their operation. what we are doing with the system is using artificial intelligence or machine learning to try and predict the outcome of surgery for patients, so essentially trying to predict what complications they may have and also to try and work out potentially the best site for them to have their surgery. staff shortages and ongoing fallout from the covid—19 pandemic have placed immense pressure on the nhs. cutting waiting lists is one of a growing list of priorities for the health service. we are currently working with hip and knee replacement, and that's partly because it is a very common operation. most patients do not require

intensive care facilities when they are having an operation but some do, and it is important to work out which patients require which hospitals when they have their surgery, and what we are working with, with this machine learning algorithm, is to try and improve that prediction. with over six million people waiting in the uk waiting for routine hospital treatment, hospital waiting lists have become a massive issue, putting increasing strain on the system. hospital trusts are exploring and experimenting with things like this al, to try and tackle the problem, but with wider concerns about artificial intelligence and data privacy, are these technologies a good fit with healthcare? the bma has been concerned for a while about the use of data, particularly patient identifiable data, being sold to parties for profit—making reasons. there is a tension in the system because you need to make sure that the different systems that you have got can intra—operate so that one app can talk to another app

so that the information can be shared usefully. you've got to make sure that any new systems that get brought in respect the patient�*s privacy and respect the importance of the nhs�*s intra—operation being done in a secure way. northumbria's ai model is hosted in microsoft azure cloud, using the company's machine learning infrastructure. the raw data entered into the system is anonymized. microsoft doesn't and cannot look at the data that's created in projects like this. the data belongs to the nhs and belong to patients and clinicians. this technology could be applied to different types of surgery and while it is likely artificial intelligence will have a greater role to play in medicine in the future, healthcare professionals stress that this is stilljust a tool to help inform decisions made by human caregivers. that was marc. laughter is the best medicine, they say, well, not the scientists but if you're looking for something

to tickle your funny bone, the edinburgh fringe festival is a great place for treatment. the tickle of that hair, the most beautiful feeling i have had in my whole life. but in the two years when live shows were cancelled, comedy has taken a turn. aw, whoa, who are you? i'm julie from four months in the future. actually? a new type of comedian has arisen, one who films their own sketches and posts them on youtube, instagram and tiktok and who sometimes could become a viral sensation. tiktok actually has quite a big presence at the fringe this year. it is one of the main sponsors. it's invited several creators down to make tiktoks about the event and, in fact, some comedians onstage started their careers on tiktok. the question is, does that kind of funny work in front of a live audience? # but my sister just saw you on tinder,

# my friends made that account as a joke. chloe and tabby are the sugarcoated sisters. their reworked covers and original songs have won them 35 million views and several awards and their most viewed video is an original number about tabby�*s type 1 diabetes and chloe's bipolar disorder. # yourjokes are fat—phobic, try to stay in range # and my blood we are constantly adjusting # got no time to feel judged # and the chronic with the chronic disease. at the fringe, they made the leap to live with an especially—written show called bittersweet and they told me that performing on social media and now on stage may help everyone talk more openly and have a laugh. i trained as an actress in musical theatre. one of my biggest insecurities was the fact that my type 1 diabetes would hold me back and, you know, i did not want to have a pump because i thought, if i was dancing it

would get in the way, or casting directors would think i would be a hassle and would not want to hire me and blah, blah, blah. whereas now, it's like, i feel incredibly unapologetic about the fact that bipolar and diabetes is part of the deal. it informs our comedy, it informs the way we are as people, it informs our creativity. # call me crazy # say i'm lazy tiktok famously has a very effective algorithm, putting the right content in front of the right eyes and helping budding performers to find their audiences in record time. it kind of levelled the playing field in the sense that, if you have ten followers, you are much more likely to get a viral hit than on other platforms. because on instagram, if you had ten followers, no—one would see your videos. on tiktok there is always a chance it but go viral. that's the difference. so you have come from very highly produced videos, where you can control exactly what they look like, because you are editing them to fractions of a second. now you are performing live, one—take wonder, in front of an audience — those just seems so different.

how have you found that difference? there is so much scope for error. and so much stuff that is not in our control. on tiktok it is actually all in our control. people would come for the jeopardy? people would come for the peril? they did. also the difference between tiktok and the live shows as well is that the tiktoks that we put out are done. once we press post, it is out of our hands, it will either go well or it won't. but with the live show, it is live, it is there for the hour. it is a changing organism. which is really exciting. ok, right now watching this, there is at least one person who wants to start the journey you are on now. they want to make content but maybe they do not have many viewers. what is the advice? maybe it'sjust testing loads of stuff and getting out there. try not to be too perfectionistic. just put something out and see what happens. it is a quantity thing, not quality thing. wow, that is very

honest, actually. so if you can just be yourself, and eventually you will tap into a market of other people that are looking for creators to voice the things going on in their heads. good luck with the show and thank you so much for your time. it has been brilliant. thank you, spencer, it has been really fun, thank you for having us. and now it is time for a look at this week's tech news. meta and geo are launching a new grocery shopping experience on whatsapp in india. customers will be able to browse their groceries on whatsapp, add items to a cart, and then make a payment without ever leaving the chat. moxie, a large boxed—sized device on nasa's perseverance rover has reliably being creating oxygen on mars since 2021. researchers on the mit—led experiment envision a larger version could be sent to mars for a human mission to continuously produce oxygen at the rate of several hundred trees. and that is a substantial accomplishment and maybe more

important though is that it brings closer to the day when we can the umbilical cord to earth. ——when we can cut the umbilical cord to earth. after an experiment with al, the french government has amassed 10 million euros. the software developed by google and capgemini has spotted more than 20,000 hidden swimming pools which must be declared under french law. and finally, google is paving the way for multi—device connectivity. the software is in development and aims allows android apps to be able to work across all devices. apps will be able to play across android, discover nearby devices, and establish secure connections. as we have seen from comedy acts, like the sugarcoated sisters, social media has a lot of power these days. it can launch careers and it can carry messages far and wide.

sometimes those messages and opinions can be carried much further than they should be, retweeted, amplified, made to look more widely held than they really are by users who are not real people, they are bots. it is really hard to tell what is a bot and what is not a bot, just ask elon musk. and james clayton has been finding out why. twitter says that it has nearly 240 million monetizable daily active users. millions of those accounts though are not real, they are bots, spam and fake accounts. that is something that twitter, and elon musk accept. but what they don't agree on is how many accounts are fake or even what a bot is. depending on how you define bot, you could have anywhere from less than !% to 20%. from less than i% to 20%. it is a debate that has turned into $41; billion question as elon musk attempts to back out of a deal to buy twitter.

so how many bots are there on twitter? first of all twitter claims that less than 5% of all of its daily active users are bots. elon musk, though, says that figure is nonsense. what do you think it is? what is the... if it is not 5%, what is it? i think it is a number- that is probably at least four or five times that number. this is why elon musk, at least he claims, is backing out of the deal. he has even accused twitter of fraud. the centre of the disagreement comes down to a definition. what actually is a bot? michael carney is founder of twitter bot0rnot. you have an account thatjust tweets out gibberish based on a computer algorithm, but then one time, if that account is tweeted from someone�*s cellphone and a real person making their honest comment on the world — is that a bot account or not? so it is not a static thing that exists.

without an agreed—on definition, elon musk had a go at trying to estimate the number anyway. in his countersuit his team claimed to use a tool called botometer, and concluded that 33% of all twitter accounts were bots. the problem is botometer doesn't actually say whether an account is a bot or not, just a score out of five. five being likely to be a bot, zero unlikely. so where did elon musk draw the line? so how to choose this threshold is key to the answer of how many bots are there on the platform. it is not clear what elon musk�*s team did, right. so to me they can choose any threshold they want. twitter�*s bot claims are also at the very least questionable. this is clayton davis, one of the researchers who created botometer. twitter has slightly conflicting boundaries, on one hand they care about credibility but they also care about having high user numbers. that charge was backed up by twitter whistle—blower

and former head of security, peter zatko, who claimed that twitter executives are financially incentivised to count bots as people. this all comes down to how twitter actually counts its bots and it is way less techy than you might imagine. their chief executive parag agrawal described in a tweet how they do this: elon musk says that is totally unscientific. and yet the creator and maintainer of botometer, the tool that elon musk is using thinks that twitter�*s methodology actually isn't that bad. if i were the people in twitter i would probably be doing something similar. it is still to me how they define those things. it is not clear. if they really want to do this, they can sit together so we can say oh, can we agree on this account is a bot, this account is a human. but twitter and elon musk aren't sitting down together, they simply cannot agree how many bots twitter has, and that is the fundamental

problem — perhaps no—one can. that was james. so i have been at the edinburgh fringe festival to find out how tiktok is giving a new type of comedian a chance to spread their funnies further. but i also wanted to get the thoughts of a more traditional stand—up comic. it is such a dream to be on click, i love this show. that is just the weirdest thing i've ever heard — him saying that to me. when he is not devouring past episodes of his favourite tech programme, philwang is one of several huge comedians whose gigs have been filmed for streaming services. in fact he also kick—started his career using online video. my first solo show in 2013, ijust recorded it myself, and put it on youtube. because i thought no—one else is buying this, so i might as well put it somewhere. and also because youtube was where i learned stand—up. i wonder whether we are going to see two types of comedian emerge from this. the comedians who have cut their teeth on live audience but also

the comedians who built their craft around highly produced videos, who are giving much more of a performance rather than interaction with the audience. i think the way i see it is i don't think things like tiktok have separated comedians into two streams, i think it has just provided a new way for comedians we wouldn't have seen otherwise come through. because they are two very different things, live stand—up, live comedy, and making videos for online. and they are very few, as far as i can see, comedians who are good at the live stuff who can be pretty good at the online stuff. do you think you could have built your career and your skills in this new world rather than building them in front of live audiences doing gigs? frankly, i think i am too lazy to have done well in this new model. it takes so much impetus, and so much discipline. these people, they are notjust going on tiktok and making silly videos, they are planning, they are writing, they are performing, they are doing many takes, they are editing, you know,

they are actors, writers, producers and directors all in one. and the very successful ones are doing it a lot. just because they are funny on stage doesn't mean comedians are always funny offstage. but if you want to know why this is happening, i will post the full thing on social media for you. meanwhile, let's leave the fringe and head to the coast now where kitty knowles has been looking at how sailing is going green out in the blue. sail gp is one of the biggest events on water. teams from australia, along with great britain, canada and new zealand, are leading the pack so far, and the third leg of this year—long event is being held right here in the uk city of plymouth. 0n race days, these boats go faster than 60 miles an hour. commentator: the french are trying to barge in. wow, that was punchy as the line went clear. but speed isn't the only thing the pros here are getting

competitive about. as more of us think about our climate impacts, they are hoping to earn points and a place on the podium by going green. this is the second year that an impact league has taken place alongside the main sail gp competition. and who better to show off the british boat than three—time 0lympic medallist, hannah mills. how's it going, hannah? nice to meet you! nice to meet you too. the gbr catamaran has been tailored for green efficiency, with greener boat paint and kit, and 3d printed materials replacing throwaway ones. for safety, we have spare cable on the boat in case something goes wrong. beforehand you need to attach the boat by cable ties, so we 3d printer these, the right shape, tested it and then it got rolled out across the whole fleet so actually it is like, i think we save about 2000 cable ties per year. solar panels are rigged o the pier to power the kitchen.

the solar panels feed into, that then feeds into here, and the batteries, and this thing here turns it into 240 volts, so we can power anything in the container. so the solar is charging the batteries, the battery is charging the fridge, and the fridge is keeping all the team charged up. mainly the coffee machine. both of those items are essential. with every bit of energy consumed counting against them, britain's chaser boats have been kitted out too. which one is our boat then? we have a lot of electrical equipment. so we have got all these screens here, a lot of radios, all things that need to be powered up and charged. we decided, could we test a solar set up on the boat so that it can charge these all the time, so that when we come to the boat, they are ready to go and we don't have to run the engines?

hundreds of low—lying coastal cities like plymouth could soon be hit by rising sea levels, putting people and homes at risk. this grand prix location and others like st tropez and sydney face a future where water could rise 50 centimetres by 2050. so it makes sense that the main competition is cleaning up its act too. you have to get your house in order and operate events sustainably and actually shift the industry you are in. for me the opportunities in the marine industry are clean energy and i am really proud to say that over 70% of our temporary power is from green energy. robotic buoys are being used as racetrack markers and can be moved into position more easily. and when these are on the water, they are not anchored to the sea floor and that protects all the creatures that are living there, even the crabs. and solar is being scaled up to power the site as a whole. given the energy prices

and the issues we are having, it will save money, is more efficient and it's environmentally friendly. win—win. win—win for everyone. obviously we know that sail boats are green already and we have seen so much innovation on site, but where is there still improvements to be made? we have a lot of non—clean energy powered operations here at sail gp, we have on—water fleet around the f50, most of them by petrol, except for the electric engines which we are trialling. helicopter in the air, again, broadcast technology — everyone knows we need to solve it but it is all about finding the right innovations to do that. sailing out to see the boats in action feels all the better from an electric rib that isn't polluting the environment. team great britain over there, can't spot the solar rib but with this sunshine i'm sure it is making the most of it. commentator: 0h! but whoever wins sail gp or the impact league, greener sports will always be

a winner in my book. that was kitty knowles out on the water. can ijust say, brilliant! that is it from us from the first full edinburgh fringe for a couple of years, and it has been wonderful to be back. next week, we are going to be at the massive berlin tech show, ifa, the first time that has been on for a couple of years as well, and i cannot wait, so thanks for watching and i will see you in berlin. hello. the second half of this weekend continues with this mixed picture across the uk — warm sunshine for some, heavy rain for others. the heavy rain tied in

with this slow—moving area of low pressure, which stays with us as we go into the new working week. and we start sunday with some heavy rain initially across northern ireland and northern england, pushing its way north and eastwards across scotland, not reaching the northern isles until much later in the day. the showers elsewhere will fade through the morning, some spells of sunshine, but likely to see some heavy showers developing across south—west england through the afternoon. showers are likely to crop up almost anywhere, could be heavy and thundery where we do see them but quite well scattered, east anglia and south—east england staying mainly dry. quite a breezy day, particularly for irish sea coasts, where we could see stronger gusts for a time, but a warm day for most of us, especially across east anglia and south—east england, where we see the best of the sunshine. 2a, 25, maybe even 26 celsius here, and the low to mid 20 celsius for many of us. through sunday night, we see another band of heavy rain pushing up from the south, and that is likely to affect a large swathe of the uk. heaviest across england and wales, perhaps not reaching the far north of scotland until much later in the night.

once again, it is a warm and muggy night, with temperatures not much lower than 1a or 15 celsius. so, then, we start the new week still with this area of low pressure to the west of the uk — it is going nowhere fast. notice the squeeze on the isobars, so still some stronger gusts of wind, particularly across south—west england and for irish sea coasts, and further showers as well on monday. the rain initially heavy across northern england and scotland through the morning. it will be easing away, and actually behind it, a good deal of sunshine but there will be some showers cropping up, and where we see them, again they could be heavy and thundery, somewhat hit and miss, some will have a largely dry and warm day, again temperatures in the low if not mid 20 celsius as we start the new working week. this area of low pressure really isn't going to go away through much of next week, slow—moving eastwards across the uk, and it is going to bring showers or longer spells of rain on most days, some much—needed rain, but we need to keep an eye on the south of england, because we could see some very heavy rain here for a time

through the week. one way or another, most of us are going to see some showers or some longer spells of rain in the week ahead, and the temperatures will be slowly coming down, too. bye— bye.

this is bbc world news. i'm rich preston. our top stories: president zelensky of ukraine urges europe to remain united in the face of russia's use of energy as an economic weapon — his wife tells the bbc about the continuing impact of the war on the ukranian people. translation: the prices are going up in ukraine i as well, but in addition our people get killed. so when you start counting pennies in your bank account or in your pocket, we do the same and count our casualties. donald trump accuses joe biden of being the real enemy of the state, days after the president branded him a threat to american democracy.