a break on rest of the week... a break on tuesday but after that, the impact of low pressure starts to be felt. temperatures close to normal for the time of year. this is bbc news. our latest headlines: sources tell the bbc that traces of the nerve agent used to poison sergei and yulia skripal was found on and around the table where they ate in salisbury last sunday afternoon. it comes as england's chief medical officer says up to 500 diners and pub—goers have been told to wash clothes and possessions. the chancellor says there's cause for economic optimism ahead of his spring statement on tuesday. china approves the removal of term limits for its leader — it effectively allows president xi to remain in power indefinitely. rail delays continue after pro—kurdish demonstrators force the closure of manchester piccadilly station. do stay with us on bbc news. coming

up do stay with us on bbc news. coming up now, click. this week: the app that helps record and report sexual assault. the ai going after cancer. and the man who wants us all to live forever. as international women's day was marked this week, it brought with it further focus on the many issues still to be faced in bringing about true gender

equality in all walks of life. the technology industry, of course, has its own issues, as we'll hear later. silicon valley's culture and its treatment of women raises a lot of questions. but tech can also be a force for good. it's beenjust six months or so since the me too movement gave a voice to so many women around the world, who used social media to expose just how widespread sexual harassment and assault is. many women feel that reporting sexual assault can also be really traumatic, and the experiences of some women in silicon valley have spurred them to create something that may make thatjust a little bit easier. sumi das has travelled to stanford university to meet survivors of sexual abuse, and the creators of callisto. every tattoo tells a story. for stanford university studentjacqueline lin, the story is bittersweet. lin was one of 50 sexual assault

survivors invited to share the stage with lady gaga during the 2016 oscars. while we were rehearsing, i remember at one point we were all crying and hugging each other, and someone just said, "we need to get a tattoo to commemorate this and to give us strength." something to look at when you are feeling down, and you know that you're alone. lin says that a few days after she was assaulted by a friend in 2015, she told the title ix office, which investigate sexual misconduct. i decided to report because i didn't want him to do it to anyone else, and later i did find out that he had done a lot of... a lot of harassment, stalking and also assault on someone else. what was that experience like? it was awful. my gpa dropped down, and i was fighting with the school back and forth every single hour, every single day. lin, now an activist, wants greater transparency

in the adjudication process. they're trying to cover up the number of sexual assault that happen on their campus, because that makes your university look safer. it's better for your public relations. stanford told click: stanford changed its title ix process in 2016 and has begun reporting case numbers. in the us, one in five women is sexually assaulted while in college. i was sexually assaulted by a friend. over a year after that happened, i decided to report my assault, and i ended up finding the process of reporting to be more traumatic than the event itself. feeling not believed by the people who i thought were there to protect me was incredibly destabilising. jessica ladd's ordeal spurred her to create callisto, so survivors would have a way

of reporting sexual assault. they can, one, just say what happened to them with a timestamp, doesn't have to go anywhere if they don't want to. two, report electronically to the authorities at their school. 0r three, just say what happened to them for now but report electronically if someone else names the same assailant. you can think of callisto as an international information escrow agency. it holds onto records and only alerts schools when there's a match. students often report to protect others. this matching feature helps do that by detecting repeat offenders. people might use different names, they may look different. how do you make sure you've got the right person? we ask victims to put in notjust the name of their perpetrator, but also a series of unique identifiers. currently, facebook profiles are used to match. some students want more ways to id, and callisto may add mobile numbers and e—mail addresses in the future. 12 us colleges use callisto. the university of san

francisco was the first. we knew students weren't reporting. if you look at our numbers from once we first started with callisto, three years ago, to now, there is definitely an increase in reporting. callisto allows for our students to write what happened, to write about the incident. and sometimes just writing your perpetrator‘s name gives people power. seeing the need for callisto, shanta katipamula led an effort to bring it to stanford. it is just available 21w, and they have seen spikes in usage during times like spring break, when the title nine office might not be available, but students wanted to file a report, or during the weekend, when no—one‘s staffing. with callisto, survivors recount what happened at the own pace, privately. 0ften victims, including in in—person interviews, will want to seem credible, so they want to fill in all the details and tell a wonderful story arc. but that's not how memory works, and that's particularly not how

memory works in the event of trauma. so being able to allow somebody to say i don't know the centre, i am not sure that, and only record think that they are sure of, is really essential to make sure that that time stamped record isn't later used against them. students must create a username, password and pass phrase that can't be recovered. not quite a one—click sign up. that deters some users. for callisto, it ensures privacy. since students choose whether to report assaults, some records are never seen by schools. but they're still useful. we provide our institutions with at an aggregate data report that gives them a better sense of what is happening in that store record, what type of years are assault occuring,

what type of assault is it? is it involving alcohol, is it not? what class years are involved? others are also working to make reporting less daunting. the spot app creates a record from the user's conversation with a chat bot, while all voices will let them report electronically. lin isn't sure electronic reporting would have changed her was handled, but she see the potential. what i think callisto is great for is to track perpetrators. if they decide to apply for grad school or transfer schools, i think that's where this can really come in and have a very powerful effect. as we grow, we want to create one system, one database that allows us to track any perpetrator, even as they move through space and time. which would give survivors a way to find out if their assailant is a repeat offender, something ladd says she wonders to this day. that was sumi das at stanford university. now, while callisto was created a team of mostly women, that is rare.

even right here in silicon valley. whenever i've been to visit, i've found it all too easy to think of the valley as sharing the progressive values of san francisco, where all colours and genders seem welcome. but the people i have met, those in charge of the start—ups and tech giants, have been mainly men. it is quite obvious to us that women are underrepresented here, and there are those who feel that silicon valley is just as full of sexism and masculine culture as anywhere else. it's the social challenge where the majority of people... emily chang is a san francisco journalist, and the host of bloomberg technology. and in her new book, brotopia, she's written about the industry that has always self—selected for men. first came the antisocial nerd who suddenly became part of the ruling class, and now she says it's the time of the cocky, self—confident risk taker, the bro.

silicon valley is the heart of the most powerful industry in the world, and that is the technology industry. this is a world that is controlling what we see, what we read, how we shop, how we communicate, how we get around. the reality is, the exclusion from this incredible and progressive industry was not inevitable. it didn't have to be this way. i think of all the women out there who might have started the next facebook or the next google or the next apple, but never got the chance because they didn't look the part. and that is something that needs to change. women hold just 25% ofjobs across the computing industry. they account for 7% of investors. women—led companies getjust 2% of venture capital funding. the most important thing that we need to do is to acknowledge that silicon valley has become toxic for women. so what is bro culture? well, it is exactly what it sounds like.

fratty parties, beer, behaviour that is alienating towards women. i had 12 women overfor dinner at my home, most them engineers who work at companies like uber and google, and the uber engineers told me specifically they would often be invited to strip clubs and bondage clubs in the middle of the day, there was a heavy drinking culture. and so much of the work in silicon valley gets done outside of the office, so at the bar, at the conference, in a hotel lobby, and they're stuck in sort of an impossible catch—22. if they attend, they're disrespected and discredited. if they don't, they're shut out of important business and networking opportunities, because very powerful people, very powerful men, are at these parties. so many female entrepreneurs that i've spoken to have notjust one story, but several stories to tell about how an investor has crossed a line. you know, one of the most sort of egregious examples that i have found is an investor who... a very prominent investor

in companies like twitter and uber who often hosted hot tub parties at his home. well, what female driven wants to get in a hot tub and future business while wearing a bikini and drinking beer? these are the kinds of activities that have been very alienating to women, and unfortunately have created a very unlevel playing field in silicon valley. i think about how different the world might be if women had been at the creation of some of these companies from the start. i sat down with twitter co—founder ed williams, and i asked him, if women had been involved in the founding of twitter, would online harassment and trolling be such a problem? and he said he doesn't think so. they weren't thinking about that when they were building twitter. they were thinking about all the wonderful and amazing things that can be done with twitter, they weren't thinking about how it can be used to send death threats or rape threats. and as a result, online harassment is one of the biggest problems plaguing internet today.

if women had been more involved in building these products and building these services, maybe online harassment and trolling wouldn't be such a problem. i fully believe that the people who have already changed the world in so many wondrous ways, the people who are taking us to mars, the people who are building self—driving cars, the people who have given us rides at the push of a button, if they can do all that, they can change this too. hello, and welcome to the week in tech. it was the week that sony blocked the videogame super seducer for being released on the playstation 4. it's been criticised as too sleazy and for promoting toxic behaviour. dyson announced it won't be making plug—in vacuum cleaners any more, they'll be developing their cordless battery range. dating app bumble has banned members

from posing with guns in their profile pictures, though an exception is being made for military and law enforcement officers in uniform. solving in three, two, one. and a robot managed to solve a rubik's cube in under a second. blink and you'll miss it. here it is again in slo—mo. it was the week that mobile companies three and vodafone came under investigation over the way they handle data on their network. 0fcom's looking at whether they're intentionally slowing down internet speeds while customers are abroad. internet artists invaded new york's museum of modern art, transforming the jackson pollock room into their own augmented reality gallery without the museum's permission. the project was called hello, we're from the internet. and finally, flippy the robot has been working at a restaurant in la. itsjob — yep, you've guessed it, is flipping burgers. it uses image recognition and heat sensing to cook.

the company, caliburger, is installing flippy in 50 locations but it's not cheap at $60,000 a robot. hope those burgers taste good. the idea of personalised or precision medicine is really gaining ground, and in the not—too—distant future, every single time we're prescribed something, exactly what that is could be dependent on our height, weight, sex and even our genetic make—up. personalising your medication doesn't always need complex biomedical data to be beneficial, though. what i have here is the beta version of the exactcure app. you input your data first, your height, your weight, your sex and details of any other medication you're taking, because that could have an affect. after you've done that you can put in information on what drug you're about to take. and this is how you do it. so this is paracetamol.

now, i would probably take two 500mg tablets, so let's see the effect that would be likely to have. it's going to last about four hours, which is pretty much what i would've expected, but where this dark blue is showing it shows i could be ever so slightly overdosing, so someone of my height and weight maybe doesn't need to be taking to tablets in one go. whilst the dark blue may represent a little more than needed, when you're clearly taking too much the dial will turn fully red. with a simple questionnaire on you, on your environment, on your body, with something like five or six questions we can cover something like 90% of the cases and for the remaining 10% we need complimentary informations, like are you a smoker or not, which kind of regiment do you have, and of course genetics. we think pharmacists in the future should have an important role to play in this ecosystem. not only by selling

drugs but by selling the exact drug and the exact dose for the patients. artificial intelligence is at the forefront of this revolution, analysing massive quantities of biomedical data that could transform treatment. well, imagine you're a scientist and you could read every piece of information that had ever been written about biomedicine. you could store that information and then you could use it to make new discoveries in diseases. there are billions of potential combinations of genes, diseases and drugs and here hugely powerful algorithms are at work to establish the best combinations. genetics will also play a central role in personalising what you're prescribed in future. astrazeneca are analysing genomes from over 2 million people, and this data could soon be at your gp‘s fingertips. patients will actually be

at the point where maybe they'll be able to go into the clinic, go into your local gp, and have that genotype already available. the doctor will then be able to look up not only the type of genotype but also your individual genotype, and match that to the best medicine for you. some people are even talking about doing this at birth so by the time you develop a disease, the doctor's already got your dna. so any one—size—fits—all approach to medicine could soon become a thing of the past, with your prescription always being specific to your needs. that was lara, looking at the very specialist techniques that may soon treat the diseases none of us want to face. but there are those who are going further, they're notjust trying to treat, manage and cure life—shortening

diseases, they're actually trying to lengthen the human lifespan. in an unassuming research facility in silicon valley, i met aubrey de grey, who's leading a project that treats ageing itself as a disease which can be cured. and he's made some seemingly rather outlandish claims in the past. am i right you are the guy that said the world's first i,000—year—old has already been born? i always make clear that it's only something i think is probable. but yes, i do think it's probable. if we look at the logic, it's very straightforward, the risk of dying in your 20s is low. if you get to your 26th birthday your chance of reaching your 27th birthday is very high. the chance of not reaching it is less than one in 1,000. the only reason that people don't live to 1,000 already

is because of ageing, because their probability of death in the coming year goes up. it happens to go up by about 10% per year. does it, 10% per year? you are 10% more likely to die at the age of exactly 63 than you are at the age of exactly 62 and so on. blimey, that's quite high. but if we can fix this damage that doesn't happen