welcome to bbc news. i'm david eades. our top stories: a blunt warning from the us vice president on a visit to central america — don't come to the us, because you won't get in. the first new treatment for alzheimer's for nearly 20 years has been approved by us regulators. a dramatic fall in applications from asians to study at american universities is put down to an increase in racist attacks. and — going down in the world — the chinese villagers who moved from the top of a cliff to a new housing estate.

hello. thank you very much for being with us. the us vice president, kamala harris, who's visiting guatemala, has urged its citizens not to come to the united states. this is herfirst stop on a regional tour aimed at tackling the undocumented mass migration to america, right at the source. ms harris with the biden administration are pledging $310 million in immediate humanitarian aid. in addition, there will be long term investments worth $4 billion to boost development and security across the region. it's notjust money, though, last week the us said it would send 1.5 million vaccines doses to guatemala and mexico. at the same time, one us aid study looking into programmes in guatemala found that from 2006 to 2011, incomes rose less in places

that got us funding, compared to similar areas that received nothing at all. and the numbers heading north keep growing. in april, us border agents encountered nearly 180,000 migrants at the border — that is a 20—year high. i want to emphasise that the goal of our work is to help guatemalans find hope at home. at the same time, i want to be clear to folks in this region who are thinking about making that dangerous trek to the united states—mexico border, do not come. our us partner cbs is travelling with kamala harris. senior white house correspondent ed 0'keefe is live in guatemala city. it's very good to see you. it certainly is a pretty blunt message, even if there is a financial cushion to soften the blow. it financial cushion to soften the blow. , . , financial cushion to soften the blow. , ., , ~ blow. it sure was, david. and

in some _ blow. it sure was, david. and in some ways. _ blow. it sure was, david. and in some ways, lays _ blow. it sure was, david. and in some ways, lays a - blow. it sure was, david. and in some ways, lays a red - blow. it sure was, david. and in some ways, lays a red line for the biden administration. saying they are going to be securing the border. but what if they do, and the wave continues over the next several months and in coming years? does that mean the biden administration will change immigration policy? that is going to be a question they face. and i also find it interesting that you put there, the offer of aid has been consistent for several months, but it is important to figure out the issues in central america. out the issues in central america-— out the issues in central america. . ~ ~ america. yeah. well, ithink, ou america. yeah. well, ithink, you know. — america. yeah. well, ithink, you know. you _ america. yeah. well, ithink, you know, you make - america. yeah. well, ithink, you know, you make a - america. yeah. well, ithink, you know, you make a good i america. yeah. well, i think, - you know, you make a good point that there is this — you are prepared to make the point

there is a quid pro quo low here, it doesn't come from nothing. corruption prevention, an important issue. and just listening to how you put it. that have a listen to this. do ou that have a listen to this. do you consider the governments in el salvador, guatemala, honduras or pneumatics go —— mexico — honduras or pneumatics go —— mexico to— honduras or pneumatics go —— mexico to be corrupt? gn honduras or pneumatics go -- mexico to be corrupt?- mexico to be corrupt? on the issue of corruption, _ mexico to be corrupt? on the issue of corruption, the - mexico to be corrupt? on the issue of corruption, the issue j issue of corruption, the issue i had —— conversation i had with the president was very frank and candid. this is a quality that he and i appreciate in each other. we don't have time for glassing over concerns that we have. translation:— over concerns that we have. translation: ,.,. ., translation: the social needier networks -- _ translation: the social needier networks -- media _ translation: the social needier networks -- media networks, - networks —— media networks, rather than information, give you misinformation. iwill turn the cases of —— question a new. how many cases of corruption have i've been accused of? zero. it interesting. for

kamala harris, it is a big part of her portfolio to solve this problem. how much does that way on her in terms of the way she will be perceived? it is on her in terms of the way she will be perceived?— will be perceived? it is a command _ will be perceived? it is a command this _ will be perceived? it is a command this test - will be perceived? it is a command this test of. will be perceived? it is al command this test of her mettle, really, internationally. this is her debut on the world stage, in america'syard and heading to the next—door neighbour, mexico. she faces a real test. and she at least demonstrated that she is training the biden administration —— trying with the biden administration could be an effective attack in the next election. that has been something dragging the approval rating of president biden over

the last several months. in conversations with the guatemalan president, i appreciate she is frank, she doesn't hold back and is willing to deal with these issues. that suggests a humility to speak truth to global counterparts will be important in foreign policy. it is going to be interesting. ed 0'keefe, joining us from guatemala city. we apologise for the quality of the line. it was a bit scratchy, wasn't it, but i think we got the gist of what ed was saying. a controversial new treatment for alzheimer's has been approved by regulators in the us. aducanumab targets the underlying cause of the disease rather than just easing symptoms. patient groups have campaigned for its approval, but it's a contentious decision — some experts and the federal drug agency's

independent advisory committee opposed its approval. 0ur medical editor, fergus walsh, reports. this is an historic moment in the battle against alzheimer's. for the first time, a drug has been approved which tackles not just the symptoms but the underlying cause of this devastating disease. aducanumab is not yet licensed in the uk and available only as part of a clinical trial — like here, at the national hospitalfor neurology, in central london. aldo ceresa, who's 68, was diagnosed with alzheimer's ten years ago and had to stop working as a surgeon. he receives aducanumab every month, via infusion, and is certain it's helped him. i felt that i wasn't getting so mixed up. my cognitive tests were improving quite markedly. two years ago, aducanumab was written off as a failure and the trial aldo was taking part in was abandoned. but the manufacturers, biogen, analysed more data and concluded those on the highest doses had better cognition, memory and language.

this is the brain of someone with early alzheimer's. the red areas show a build—up of amyloid, a protein which can form toxic deposits. this is the same individual after a year of aducanumab — significant amounts of amyloid have been cleared. so, this drug was approved on the basis of this drop in amyloid that you're seeing here. the doctor who is leading the clinical trials of aducanumab in the uk is delighted. this is a pivotal moment for the alzheimer's research community.

this will give hope to the people who haven't had any hope for a very long time. those patients and participants in my trials who are desperate to find something that helps. in recent years, over 100 promising alzheimer's drugs have flopped, so to now have a medicine that can potentially slow the disease is a huge moment and will encourage scientists to redouble their efforts and find even better treatments. aldo has been back on aducanumab for six months and says he's already beginning to feel the benefits. i've noticed that i'm getting less confused. although it's still there, it's not quite as bad. and i'm just feeling that bit more confident now. aducanumab is suitable only for those with mild alzheimer's, when damage to brain function is still limited. it could take more than a year before uk regulators decide whether to approve the drug. if they do, demand here will be enormous. fergus walsh, bbc news. the us government says it has managed to recover $2.3

million worth of cryptocurrency which had been paid to hackers who shut down a major fuel pipeline last month. the colonial pipeline was hacked by a group called darkside, which the usjustice department believes is based in russia. the cyberattack caused petrol shortages and price hikes across the eastern united states. bryan cunningham is executive director of the university of california's cybersecurity policy and research institute. he joins us from seattle. first of all, how did they track the money down? well, this is what _ track the money down? well, this is what were _ track the money down? well, this is what were common - this is what were common methods in mail days as caa officer. they are not going to reveal many of their tricks are

-- cia. reveal many of their tricks are —— cia. they went to a united statesjudge —— cia. they went to a united states judge who —— cia. they went to a united statesjudge who had —— cia. they went to a united states judge who had the authority to act the hacker is —— hack the hackers. it authority to act the hacker is -- hack the hackers.- -- hack the hackers. it feels like we have _ -- hack the hackers. it feels like we have equalised - -- hack the hackers. it feels like we have equalised after| like we have equalised after going 1—0 in a soccer match. how easy was it for the hackers in the first place?— in the first place? this is frustrating _ in the first place? this is frustrating to _ in the first place? this is l frustrating to cybersecurity experts. 0n the one hand, this uptake on attacks in critical infrastructure, whether it is gas transmission or the food system, is a genuine threat to national security eight on the other hand, ransomware is one of the easiest possible attacks to prevent if you are a business, including a critical infrastructure sector. you simply backup your data in a system that is not connected to your regular database system. you train your employees not to

click on suspicious links, you exercise crisis response methods and you should never get hit. it's great the justice department and intelligence community was able to get this money back, but it is terrible that it happened in the first place and it has to change don't make it is extraordinary that such measures are not accepted as the way it goes. at accepted as the way it goes. at the same time, they have a choice, colonial, to pay up or lose their things. could they have said, sorry, not vault? this is why the backup is so important, right? if they had copies they could still run their business. in their case, law enforcement will always say never pay a ransom. i have a lot of sympathy with that position. as someone who counsels companies on site for security, sometimes you just don't have a choice. we were, by all public reports, days, if not hours away from not being

able to run mass transportation on our east coast, and damage to gas lines i can understand executives in that moment saying we better pay up so we can get back business. i do not fall them for that, i fault them for letting it happen in them for letting it happen in the first place.— them for letting it happen in the first place. one assumes that it is _ the first place. one assumes that it is really _ the first place. one assumes that it is really a _ the first place. one assumes that it is really a very - that it is really a very effective, secure secret currency, in many ways. the fact that the fda managed to access an account, what does that tell you? —— fbi. i access an account, what does that tell you? -- fbi.- that tell you? -- fbi. ithink ou that tell you? -- fbi. ithink you have _ that tell you? -- fbi. ithink you have to _ that tell you? -- fbi. ithink you have to separate - that tell you? -- fbi. ithink you have to separate the - that tell you? -- fbi. ithink. you have to separate the block chain technology that bitcoin runs on, which is by all reports very safe and secure, in terms of recording transactions accurately and keeping them from bad guy theft, from these digital wallets themselves. apparently this was a very long investigation into darkside by the fbi and other intelligence

agencies. they probably have a lot of spooky ways do nowhere a while that is ——to know where a wallet is. they had a federal judge issue a warrant to help them. i am judge issue a warrant to help them. iam not judge issue a warrant to help them. i am not a judge issue a warrant to help them. iam not a bitcoin investor, but i would not be scared if i were.— scared if i were. thank you, b an scared if i were. thank you, bryan cunningham, - scared if i were. thank you, bryan cunningham, a - scared if i were. thank you, i bryan cunningham, a pleasure scared if i were. thank you, - bryan cunningham, a pleasure to speak to you. and a pleasure to have you with us. stay with us on bbc news. still to come: the flying boat of venice — could this be the vehicle that helps safeguard the future of the ancient city? the day the british liberated the falklands. and by tonight, british troops had begun the task

of disarming the enemy. in the heart of the west german capital, this was gorby—mania at its height. the crowd packed to see the man who, for them, has raised great hopes for an end to the division of europe. it happened as the queen moved towards horse guards parade for the start of trooping the colour. gunshots the queen looks worried but recovers quickly. as long as they'll pay to go and see me, i'll get out. there and kick 'em down the hills. - what does it feel like to be the first man to cross the channel by your own power? it feels pretty neat. it feel marvellous, really. this is bbc news. the latest headlines: the us vice president — kamala harris — has warned guatemalans against coming to the united states — saying they would be

turned back at the border. the first new treatment for alzheimer's for nearly twenty years has been approved by us regulators. with the new academic yearjust months away, universities are sifting through applications to offer places. last year, the us recorded a drop in student visa applications — and this year the number has fallen even further. as sarah toms reports, the pandemic is partly to blame but many students also worry about rising violence against people of asian descent. singapore student dai xiang rong has always dreamed of studying in the usa. he worked hard and got a coveted place at yale university to take computer science and economics. but the 19—year—old has had second thoughts. for a lot of people, especially asians like myself and my friends, you've seen the recent news of anti—asian racism and attacks, especially in the us and other countries. it's quite a deterrent to our dreams to pursue an international education

and it might be because of the pandemic, but beyond that i think there was some sort of racism that was already ingrained in a lot of people's minds. foreign student enrolment at us universities has dropped 16% between the autumn of 2019 and 2020. the stats on new international students look even grimmer, with a 43% drop. health concerns are a major reason as the us has been hit hard by covid. but racism and violence against ethnic asians are also causing many applicants to pause. some people directly blame the anti—china rhetoric of former us president donald trump. kung flu...kung flu. (crowd cheering). attacks against asians in the us, including the murders of six women in atlanta, have sent shock

waves through asia. many asian students are still very willing to study abroad and in spite of the racism, so what they do is they tend to segregate, and they tend to segregate into the ethnic communities, so this will to some extent intensify the racism. to universities, foreign students like these ones here in singapore, bring in plenty of money by paying higher tuition fees. beyond money, they also bring diversity, fresh ideas, and connections for the future. many experts believe western countries risk losing their competitive edge if foreign students feel unwelcome. missing out on all of that will have repercussions for not only universities but entire economies. as for xiang rong, he is willing to take the risk to pursue his dream. sarah toms, bbc news, singapore.

let's get some of the day's other news police in canada have arrested a man accused of killing four members of a muslim family with his pick—up truck. the police say it was a premeditated attack. the victims haven't been named, but the oldest was 7a and the youngest 15years old. a nine—year—old boy survived. police in western india say at least eighteen people have died after a fire swept through a chemical manufacturing plant near the city of pune. most of those killed are said to be women workers. local media reports said those killed in the incident were trapped following an explosion in a machine. airline bosses have called for a uk—us travel corridor to be opened up. nearly all uk passengers are currently banned from travelling to the us, while any us travellers are required to quarantine in the uk. the airlines say travel between the countries, which have some of the highest levels of vaccination in the world, is "essential to igniting economic recovery".

the founder of amazon, jeff bezos, says he and his brother will travel into space next month on his rocket company's first suborbital sightseeing trip. a third seat on the spacecraft is being auctioned off. 0ur science correspondent rebecca morelle reports. heading to the edge of space. this is the new shepard rocket. so far, it's only flown with mannequins. now it's ready for its first real passengers, and jeff bezos, who owns the spacecraft, has announced he will be on board, along with his brother. it changes your relationship with this planet, with humanity. it's one earth. i want to go on this flight because it's a thing i've wanted to do all my life. the rocket system will reach 100 kilometres above the earth, where passengers will experience about three minutes of weightlessness, and see the blackness of space and earth's curved horizon. in the future, anyone will be able to take a ride for around £150,000 a ticket.

and it's not the only company to test if space tourism is commercially viable. sir richard branson�*s virgin galactic space plane is expected to carry paying customers by the end of the year. mission control: spacex. separation confirmed. and seats on elon musk�*s spacex capsule cost millions to go into low earth orbit. for now, these trips are only for the super wealthy, but experts say prices should drop. for the young people today particularly, it will become a reality that they could save up some money and choose to go to space, not every day, but it could be something that you could choose to spend a chunk of your savings on, and experience a few minutes of weightlessness. landing gear deployed. the new shepard flight is due to take place injuly.

the capsule carrying jeff bezos and his brother will descend back to earth with parachutes, marking the start of a new era in space tourism. rebecca morelle, bbc news. for the people of venice — life is beginning to get back to normal. most covid restrictions have been eased — and tourists are returning. but venetians face a dilemma — visitors bring money — but too many of them can also endanger the very fabric of the city. the bbc�*s tim allman has more. venice almost seems to defy nature. an ancient city of canals and waterways, its popularity could be its undoing. the sheer number of votes and gondolas can cause erosion. the constant movement of the water damage in the buildings. this may be a possible solution to a swedish designed electric boat that its creators insist could make all

the difference.— creators insist could make all the difference. here in venice ou the difference. here in venice you have _ the difference. here in venice you have a — the difference. here in venice you have a huge _ the difference. here in venice you have a huge problem - the difference. here in venice you have a huge problem with wake damage and without technology when you fly above the canal level of the water level, you reduce that by 95%. who and what troubles the waterways of this city is a big issue for the people who live here. only a few days ago there were noisy protests as the first cruise ship to disembark since covid restrictions eased set sail. reducing numbers and reducing speed may helpful but whatever the solution, is a sense that something must we don. , , ., ., . sense that something must we don. ~, don. this is an ancient city and we — don. this is an ancient city and we all _ don. this is an ancient city and we all love _ don. this is an ancient city and we all love dennis - don. this is an ancient city and we all love dennis and don. this is an ancient city l and we all love dennis and if we can help to save it we should. we can help to save it we should-— we can help to save it we should. ., , , , ., should. tourist numbers are curowin should. tourist numbers are growing once _ should. tourist numbers are growing once more. - should. tourist numbers are growing once more. the - should. tourist numbers are i growing once more. the cafe's and restaurants are seeing more custom. but if venice is to survive perhaps not everything should go back to the way it used to be.

in china's sichuan province, the residents of a 200—year—old clifftop village are being moved into new homes — as part of an initiative to tackle poverty. the village drew worldwide attention in 2016 after images emerged of residents climbing perilous rattan ladders up the cliffside to reach their homes. courtney bembridge has the details. the only way to reach this cliff top village is an 800 metre climb that takes two hours and a lot of courage. babies are carried but the children in the village have had to make the trip every day to get to school. translation: my daughter's feet are small and _ there is a gap between the ladder step. so she could easily lose her footing. now this family has moved to an urban housing estate at the bottom of the mountain along

with dozens of other families from the village. translation: i have always. wanted an apartment and now the wish has finally come true. my eldest daughter will start first grade next semester. the school is so close. we're so happy to be to bring our children here. the relocation of these villages is part of a wider campaign in china to lift 100 million people out of poverty. translation: our focus last year was to move down - the impoverished households first. now we're going to move down all the remaining villages on the mountain. the houses left behind have been transformed into homestays and tourists now make the climb. you can find out more about

that village on our website. that brings you up to date. thank you for watching bbc world news. hello there. it's been a warm start to the new week. quite a bit of cloud around on monday, but i think certainly for today, it's looking sunnier across the board. it's going to stay warm for the rest of this week, and in fact, we're going to start to import some tropical air across the country, so it's going to feel quite humid. there will be further patchy cloud and rain across northern and western areas, as low pressure will always be nearby. and that's certainly the setup into tuesday, higher pressure to the south, lower pressure to the northwest, so it does mean we'll start off rather grey for much of scotland and northern ireland, through this morning, some patchy, light rain and drizzle. but conditions will start to improve for northern ireland — skies brightening up here and across northeast scotland. elsewhere, after a bit of early cloud and mist, there's going to be

a sunny day, and it's going to feel warmer with more sunshine around. we could see 25 degrees across south east england, 22 or 23 for the northeast of scotland. there could be just the odd shower here and there, but most places will be dry.

now, as we head through tuesday night, we'll see further cloud returning to scotland and northern ireland. patchy rain here, some coastal fog, too. further south, and it's drier with clearer skies, and we'll start to see some humid air being imported from the southwest, so everywhere staying in low teens celsius. on wednesday, we'll have high pressure to the south, lower pressure to the northwest with these weather fronts, and the orientation of these pressures will draw up this warm and humid airfrom the tropics, so it really will be quite noticeable on wednesday. again, rather grey across parts of scotland and northern ireland, perhaps western england and wales. best of the sunshine further south and east. could see a little bit of light rain and drizzle over western hills, but it's going to feel warm, particularly when you factor in the humidity. could see highs of 26 degrees on wednesday in the sunshine. if you add the humidity to that, it's going to feel even warmer than the temperatures suggest. thursday's another warm and humid day. perhaps a bit more cloud across the board. patchy rain for northwestern parts of scotland and northern ireland. bit more cloud for england and wales, but some sunny spells here and there. most places across england and wales should stay dry, but it'll be a bit breezier across the board. windier in the far northwest of scotland, where we'll have most of the rain. but you can see, it is another warm day.

low to mid 20s celsius for england and wales. factor in the humidity, of course, it's going to feel warmer than that, and nights are also going to be warm and muggy. could see something a little bit fresher across scotland, northern ireland on friday. otherwise, it's going to remain warm with some sunshine into the weekend.

hello again. this is bbc news. the headlines: the us vice president, kamala harris, has warned guatemalans against coming to the united states, saying they would be turned back at the border. speaking during a visit to guatemala, she said the trip north was extremely dangerous and would mainly benefit people smugglers. the first new treatment for alzheimer's for nearly 20 years has been approved by regulators in the united states. aducanumab targets the underlying cause of alzheimer's. the drug, given as a monthly infusion, targets amyloid, that's a protein that builds up in the brains of alzheimer's patients. the us government says it's managed to recover more than $2 million worth of cryptocurrency which had been paid to hackers who shut down a major fuel pipeline last month. the colonial pipeline was hacked by a group called darkside, which the us justice department believes is based in russia.

with more and more people now planning stay—cations