JOHN YANG: Tonight on "PBS News Weekend," as jockeys and horses prepare for the 148th Streetness a look at the state of horse racing and why so many horses die at America racetracks.

Then, what you need to know about the growing use of artificial intelligence in medicine and how three native communities in Louisiana are fighting to save their tribal lands from rising sea levels.

WOMAN: We have outsiders come here, and they see the lack, and they see the loss.

We who belong here, we see what's still here, what's still viable, what still makes life in this region so precious.

(BREAK) JOHN YANG: Good evening.

I'm John Yang.

President Biden is headed into the last day of the G7 Summit in Japan while keeping an eye on the potential for economic disaster at home if he can't make a deal with Congress on raising the debt limit.

Last night, White House and House Republican negotiators met for more than an hour in the Capitol with no apparent signs of progress.

The president's due back at the White House late Sunday from his abbreviated trip.

In Japan today, Mr. Biden said he's not worried after Friday's pause and restart of the talks.

JOE BIDEN, U.S. President: What happens is the carriers go back to the principals and say, this is what we're thinking about.

And then people put down new claims.

I still believe we'll be able to avoid a default and we'll get something decent done.

JOHN YANG: The US.

Treasury could run out of cash and need to borrow to meet its debts as early as June 1st.

That's the day that $47 billion in Medicare benefits are due to be paid.

Ukrainian President Volodymyr Zelenskyy is also at the G7 Summit gathering support from world leaders ahead of anticipated counteroffensive to take back Russian controlled territory.

Today, Zelenskyy met Indian Prime Minister Narendra Modi face to face for the first time.

Modi has so far refused to condemn Russia's invasion of Ukraine.

Tomorrow, he's scheduled to meet with President Biden.

In Los Angeles.

Last night, WNBA star Brittney Griner played in her first regular season game since she was freed from a Russian prison.

Vice President Kamala Harris attended the game and spoke to Griner and her Phoenix Mercury teammates before the opening tip off.

KAMALA HARRIS, U.S. Vice President: All that you did in supporting Brittney because I know that was rough and that was so difficult for you.

A team is a team.

That's family.

JOHN YANG: The team was greeted with a standing ovation when they took the court.

Griner was the top scorer in the Mercury's loss to the Los Angeles Sparks.

She ended the night with 18 points, six rebounds and four blocks.

Still to come on "PBS News Weekend", medicine's use of artificial intelligence and native communities fight rising sea levels.

(BREAK) JOHN YANG: People will be watching this evening's Preakness Stakes in Baltimore to see if Derby winner Mage wins the second race in the Triple Crown and to see if all seven horses make it around the 1 mile oval safely.

Already during one of the preliminary races this afternoon, a horse was fatally injured and euthanized at Pimlico.

Racehorse desert tracks are alarmingly common.

Over 10 days leading up to the Kentucky Derby, seven horses died at Churchill Downs, according to a group that opposes racing as inhumane.

So far this year, 136 thoroughbreds have died, and last year, 901.

That's more than two every day.

Beth Harris covers the horse racing industry for the Associated Press.

Beth, you've heard the numbers that we cited, and they do come from a group that opposes wants to see horse racing go away.

What would you say to put into perspective and context?

BETH HARRIS, Associated Press: Well, John, I think you also have to look at some other numbers, and these would be from the Equine injury database that the Jockey Club maintains, and they take their numbers and granularize them from various race tracks around the country.

And those actually show that per 1,000 starters in 2022, the rate of fatalities declined.

It was the fourth straight year that the rate has declined.

So, everybody has their different sets of numbers, but that's generally considered the industry standard as the Equine injury database.

JOHN YANG: Are you saying that there is an acceptable level or is the industry saying there's an acceptable level of horse death?

BETH HARRIS: I think the industry would say the acceptable level is zero, but they also realize and understand that you're never going to get to zero.

It's just something that over time you can get as close to zero.

But these fatalities have a slew of reasons behind them and it's just highly unpredictable in terms of sending horses and jockeys out to race every day what could happen.

JOHN YANG: Another thing that critics talk about is the medication and doping of horses.

They say it allows or it's to keep horses competing who may be fragile in health and sort of threatening their health by doing this.

What's the industry's response?

BETH HARRIS: Well, the industry has gotten something called HISA, the Horse Racing Integrity and Safety Authority.

It's going to kick in two days after the pregnancy in terms of its anti-doping and medication controls.

They are hoping that this will be the so called central office for the Florida racing in the U.S. much like you have the Commissioner's office in baseball, football, hockey and basketball.

This will be a centralized authority that will oversee the pre-race, post-race testing.

They plan on doing extensive out of competition testing as well, and there will be a set level of standards that will be adhered to.

Also, when there is a positive test, there'll be a set procedure and they plan to notify the parties involved in a quicker fashion than what we typically have seen when it's left up to the individual racing states, which is the way it's been for many years now.

JOHN YANG: I know that it was congressionally mandated after a high number of deaths at Santa Anita in 2018 and 2019.

Has there been any opposition?

Has there anyone fighting that either in the industry or in state racing commissions?

BETH HARRIS: Very much so.

There's a handful of states as well as an organization that represents about 30,000 trainers and owners in the U.S. who have filed multiple lawsuits against HISA, claiming that it's violating constitutionality.

These groups would rather have the states and state elected racing officials mandate what's going on instead of turning it over to the higher power that Congress has approved.

JOHN YANG: You mentioned that there have been clusters of deaths, and there are multiple reasons for horse racing deaths.

But when you get clusters like the one we saw at Santa Anita in 2018, 2019, I think 30 horses died during the racing season.

You had a cluster of seven in a month at Laurel Park a couple of years ago.

This string of seven at Churchill Downs.

Is there a commonality through those clusters?

BETH HARRIS: Yes, some of the injuries occurred during training.

Some of them occurred in actual races, most recently with the death at Churchill Downs.

It was a variety of situations.

Two of them occurred in races on Derby Day.

Another occurred when a horse flipped in the paddock.

It apparently may have been spooked by something it saw and it flipped and hurt itself and was not able to be saved.

So generally, there are a variety of causes.

It could be a catastrophic leg injury.

Some horses have dropped dead of heart attacks.

Each case can be individual, and there's obviously standards by which they investigate these deaths.

They do necropsies to analyze the animal, and much like we would have an autopsy in a human being.

So there's a variety of reasons, and I think that's what's most befuddling to the industry and also to fans and the critics is that there just is no pat answer.

There's no easy answer for why this is happening.

JOHN YANG: Beth Harris of the Associated Press.

Thank you very much.

BETH HARRIS: Thanks, John.

JOHN YANG: Artificial intelligence is finding its place in all sorts of scientific fields, and perhaps none holds more life savings promise than healthcare programs are learning to answer patient's medical questions and diagnose illnesses.

But there's still some problems to be worked out.

Earlier, I spoke with Dr. Isaac Kohane, the editor-in-chief of the New England Journal of Medicine AI, and the chair of Harvard's Department of Biomedical Informatics.

I asked him about AI's potential in medicine.

DR. ISAAC KOHANE, Editor-in-Chief, New England Journal of Medicine AI: Doctors can definitely use AI as an augmentation, so they'll remember or be reminded of all the things that they should know about their patient, their specific patient, and all other similar patients like them.

At the same time, patients are all too aware that in the United States, we don't have enough primary care doctors.

And so we have very little time with doctors if we can get any time.

And so providing another, if flawed resource to get them medical advice so they can decide whether or not to actually seek medical advice is also probably going to be transformative.

When a doctor sees me, then I can tell you they've forgotten a lot of details about me.

What if you could actually just have and it's doable today a summary that says, what are all the important things that Isaac Kohane has medically that you should know about today?

And then saying, what are all the other patients who are like Isaac Kohane?

What are the right treatments?

Is he on the right treatments?

Are there any screening tests that we should do on him today during his visit?

Medicine is getting increasingly more complex.

There are more things that we know how to do for preventive medicine, but in fact, prevention is getting less and less attention in many ways because doctors are so busy.

These AI programs are not infallible.

In fact, they can make mistakes, but at least it's a conversation you can have and then you can go decide, should I actually discuss this with my doctor?

JOHN YANG: How far off are these things?

How soon before they're realized?

ISAAC KOHANE: Right now they are highly imperfect, but they're being used today.

The reason they're being used today is because there is such a great need.

We've all heard of the so called Dr. Google.

The fact is that people use search already to obtain medical advice.

When ChatGPT was released by OpenAI this past winter, patients started using it already.

We know that for a fact.

We know that doctors started using already.

People don't realize that 30 percent of the costs of healthcare are administrative overhead, the billing procedures, getting authorization, deciding whether to do reimbursements.

They involve some judgment medical judgment about how appropriate the care is, whether patients should be allowed or not.

So that is happening right now, today.

JOHN YANG: You've said a number of times that it's flawed, it's imperfect.

What should the patient be looking for?

Are there red flags that the patient should be looking for?

ISAAC KOHANE: Sometimes it can be quite subtle, but I think the obvious ones are it makes a reference to an authoritative source.

Check that source.

These programs have been known to make up citations.

I know that Google and Microsoft are working hard to eliminate those by having independent programs.

Second, I would never actually do anything that was at all risky without first checking with the medical authority.

So if it told you to change your medication, which it won't, but if it says this medication may not be appropriate, that's useful in the sense that it should allow you to have a conversation, I would not do it.

The other thing is that using human common sense turns out to be an incredibly useful filter.

JOHN YANG: Looking farther down the road, what's the promise of AI?

What do developers and doctors and others in healthcare hope that it will be able to do in the future?

ISAAC KOHANE: So I think that doctors are not spending enough time with patients.

They're spending too much times as bureaucrats.

Having AI take care of that bureaucracy will allow doctors, we hope, to interface more with patients.

That's a short term hope.

The longer term hope, which is when I say long term, I don't mean 20 years, I'm talking about five years, is that these programs will actually be able to look at all our data under the right privacy provisions and actually come up with new biomedical insights, new potential treatments, groups of patients who could benefit from these treatments and actually accelerate the drug discovery process as well.

Because again, the same limitations that were talking about human beings as doctors also afflict human beings as life science researchers, they can't know everything.

They can't know of all the discoveries that are being made at one time.

These programs are pretty good about knowing about everything.

JOHN YANG: Is that the biggest potential pitfall?

People putting too much reliance, too much trust in it?

ISAAC KOHANE: I think that is absolutely the absolute pitfall.

First of all, I would rely on our common sense.

I am not convinced, nor are others, that it has common sense at all times.

And even if it did have a kind of common sense, in the end, we have to be true to our values.

I pretty sure that at this point we cannot rely on these programs, on sharing our values.

But I think the most important thing that these companies could do would be tell us which data were these trained on, these models trained on?

We don't know what these models were trained on.

That tells me, for example, that I don't know, does it correctly represent the problems that American patients have, or did it see a lot of data from India?

And so not knowing which data were used to train these models, a lot of uncertainty around quality and applicability to different populations.

JOHN YANG: Dr. Isaac Kohane of the New England Journal of Medicine AI, thank you very much.

ISAAC KOHANE: Thanks.

It's been a pleasure talking to you.

JOHN YANG: In Louisiana, coastal erosion claims an average of a football field of land every hour.

Some Native American communities in southeastern Louisiana are the hardest hit.

Special correspondent Megan Thompson brings us the story of three indigenous communities fighting to save their land.

DEVON PARFAIT, Louisiana Tribal Chief, on Climate Change and Preserving Customs: Mama Mafin is buried all the way in the back right hand corner.

Who is my grandpa's mom.

MEGAN THOMPSON: At a small cemetery on Louisiana's Gulf Coast.

Devon Parfait pays respects to his native American ancestors.

He spent his early years here in Dulak, Louisiana, as part of the Grand Caillou Dulac Band of Biloxi-Chittimacha-Choctaw.

The tribe of nearly 1,100 people has been in the area for centuries.

But now Parfait's worried about its future.

DEVON PARFAIT: One of the biggest problems that whenever we have storms that come in, the storm surge that it brings will sometimes carry these coffins out.

And people will have to go out into the water and grab these coffins and bring them back.

MEGAN THOMPSON: The coffin that was once in this grave has disappeared.

Some of the tombstones that remain are deteriorating or turned upside down.

The destruction of this final resting place is just one part of a much bigger problem.

DEVON PARFAIT: This right here is the lot where I lived up until the second grade.

MEGAN THOMPSON: Parfait's childhood home was destroyed in 2005 by Hurricane Rita.

DEVON PARFAIT: I think about all that's been lost.

I mean, our culture, our heritage, the physical lands.

I think about the efforts going on now about coastal restoration and how they don't do enough for these communities who are living on the front lines here.

MEGAN THOMPSON: Parfait is now in a position to help change that.

DEVON PARFAIT: Great to meet you.

How you doing?

MEGAN THOMPSON: Last year, at age 25, he became the chief of his tribe.

He also earned a bachelor's degree in geoscience so he could study how much coastal land loss was affecting tribal communities.

DEVON PARFAIT: My research specifically was answering questions that other scientists didn't come down here to answer.

MEGAN THOMPSON: Parfait found that some tribal communities in this area are losing land at more than double the rate of the rest of coastal Louisiana because, he explains, tribes were pushed out to the farthest reaches of Louisiana's southeastern coast after the U.S. government forced them to relocate in the 1800.

DEVON PARFAIT: Even in my lifetime, I've noticed that the shoreline has encroached and moved further inland.

MEGAN THOMPSON: Parfait also has a new job working for the Environmental Defense Fund.

He's partnering with other tribal leaders and Louisiana State University to tackle one major cause of erosion the 27,000 abandoned canals dug over decades by the oil and gas industry that have sliced up the wetlands.

THERESA DARDAR, Pointe-au-Chien Indian Tribe: All the bayou's are getting wider.

MEGAN THOMPSON: Theresa Dardar and her husband Donald are members of the Pointe-au-Chien Tribe based in Montegut, 16 miles east of Parfait's tribal home.

They're working with Parfait to convince out siders that tribal land is worth saving.

THERESA DARDAR: Whenever we have meetings, I tell them we're the bumper, but if you don't protect us, next.

MEGAN THOMPSON: All of this used to be forest where Donald would hunt as a boy.

Now they're surrounded by water as far as the eye can see, the trees killed by salt water.

The Dardars blame the old canals, like this one, intersecting their bayou for allowing the ocean water in.

All this moving water also makes the shoreline erode faster.

THERESA DARDAR: It pretty much washes away that bottom and then eventually works its way up until it all falls into the water.

MEGAN THOMPSON: The oil and gas companies were supposed to fill the canals back in with soil, but the state stopped enforcing the requirement long ago.

So the Dardars and their partners secured over $550,000 in grants to start doing it themselves.

They hope this canal will be the first.

Research from Louisiana State University shows filling the canals back in repairs the land and is relatively inexpensive.

DONALD DARDAR, Pointe-au-Chien Indian Tribe: They got a muscle on there.

Two muscles, three muscles, four muscles.

MEGAN THOMPSON: Donald is leading another restoration project to protect the shoreline here.

He and a team from the Coalition to Restore Coastal Louisiana stack bags of oyster shells collected from local restaurants along the banks.

Over time, the barrier builds up as new oysters and mussels grow on top of the old shells.

DONALD DARDAR: The goal of this is for this to just keep growing and expanding.

Hopefully, they go bust through these bags and just keep growing.

MEGAN THOMPSON: Since 2019, they've built 2,400 foot reefs from about 400 tons of oyster shells.

During that time, the bank that isn't protected has eroded by several feet.

DONALD DARDAR: Since we didn't go no further with the bags, and right here, it eroded.

MEGAN THOMPSON: For the Dardars to have any hope of saving their land, these projects need to be done at a much larger scale.

Louisiana is already spending billions on its coastal master plan, an almost two decadelong effort to battle the rising seas.

But the Dardars feel left out.

THERESA DARDAR: We have to go on our own, looking for funds to try to save our community, because they're not.

MEGAN THOMPSON: The Dardars are fighting with another tribal leader, Rosina Philippe, to get more funding for resiliency projects and storm repairs.

For years, Philippe was president of the First People's Conservation Council, which advocates for tribes along Louisiana's coast.

She's also a tribal elder in Grand Bayou Village, 40 miles east of the Dardars.

It's a tiny indigenous community only accessible by boat.

ROSINA PHILIPPE, President, First People's Conservation Council: We've been inhabitants of Louisiana for many centuries.

Our whole lives tied around being on the coast and connecting to the water.

MEGAN THOMPSON: Damage from Hurricane Ida in 2021 is obvious everywhere.

ROSINA PHILIPPE: That dock is washed away and it needs to be replaced.

MEGAN THOMPSON: Homes are destroyed and boats lifelines for the community wrecked.

ROSINA PHILIPPE: I'm borrowing this boat today because my boat is still damaged from Ida.

MEGAN THOMPSON: Philippe's brother Maurice earns a living from fishing.

He also gives away hundreds, sometimes thousands of pounds of seafood each year to help feed his community.

But Hurricane Ida caused $25,000 worth of damage to his boat.

MAURICE PHILIPPE, Louisiana's Grand Bayou Indian Village: I've been having boats all my life, and this is supposed to be my last one, hopefully.

Seeing it the way it is right now is heartbreaking.

MEGAN THOMPSON: The Federal Emergency Management Agency, FEMA could help out.

Last year, it handed out more than $3 billion to victims of disasters.

But the National Congress of American Indians says federal money for security and emergencies isn't delivered evenly.

Tribal citizens receive only $3 for every $26 that nontribal citizens receive from the Department of Homeland Security, which houses FEMA.

ROSINA PHILIPPE: The government is paper heavy.

Paper.

It's not an indigenous concept.

It's not how we record time or events.

MEGAN THOMPSON: Tribe members often don't have documents like land deeds and home records that the government requires on top of it, many don't have basic computer skills, but the applications are all online.

So Philippe has helped create a program to train tribal members to navigate these complex government systems.

ROSINA PHILIPPE: We're trying to find a way to make the connection between who we are and what they expect.

MEGAN THOMPSON: Recently, a small victory.

After lobbying from Philippe and others, the Biden administration extended the deadline for Hurricane Ida relief in Louisiana to June 1st.

Philippe says the hard work is worth it because despite the challenges, her people will never leave.

ROSINA PHILIPPE: We have outsiders come here, and they see the lack and they see the loss.

We who belong here, we see what's still here, what's still viable, what still makes life in this region so precious.

We don't just survive here.

We thrive.

MEGAN THOMPSON: For PBS news weekend, I'm Megan Thompson in Grand Bayou Village, Louisiana.

JOHN YANG: Now online, more reporting on the environment, including Instagram story on what it will take to reduce global plastic pollution.

All that and more on our web page, I'm sorry, NewsHour Instagram page.

That is PBS news weekend for this Saturday.

I'm John Yang.

For all of my colleagues, thanks for joining us.

See you tomorrow.