CARL AZUZ, CNN 10 ANCHOR: Thanks for starting up your week with CNN 10, your objective explanation of world news. I`m Carl Azuz at the CNN Center.

First, today, we`re taking you to southwestern Europe. There are about 49 million people who live in the nation of Spain. Sixteen percent of them live in Catalonia. This is a wealthy region of Spain that held a referendum, a vote yesterday on whether Catalonia should become an independent country.

Catalonia has its own government, which determines much of the region`s health care, education and tax collection policies. But Catalonia also pays tax to Spain and some of the politicians who wanted to be independent say it`s unfair for the tax money from wealthier regions like Catalonia to go toward funding other parts of Spain.

But back in 1978, more than 90 percent of Catalan voters supported the Spanish constitution, which mentioned the indissoluble unity of the Spanish nation. Only Spain`s parliament can change that constitution and the nation`s government and supreme court have said it`s illegal for Catalonia to hold a vote on independence.

Spanish national police raided some Catalan polling stations and fired rubber bullets, in an effort to keep the vote from happening. Hundreds of injuries were reported. Most of them of civilians, but 13 officers were hurt as well. The Spanish government and the Catalan government each blamed the other side for the violence.

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REPORTER: First, it was the students, then came the firemen, and finally, the farmers. The last day of campaigning in Catalonia`s independence referendum may have drawn to an end, but the tension on the streets is only building. The Spanish government has said Sunday`s vote is illegal and must not go ahead.

Barcelona`s port has become a staging ground for Spanish police, extra forces and police vans shipped end from the across the country, all to try to block people from voting.

The Spanish government has seized millions of ballots and campaign leaflets, arrested Catalan officials and closed down political Websites.

It`s a vote long campaigned for by separatists in Catalonia. The region in northeastern Spain already has limited autonym from the central government in Madrid. It has its own flag, its own national anthem, and its own language.

But still, many Catalans want more. They want full independence for their region, which is Spain`s number one tourist destination. Famous for Gaudi - the iconic Sagrada Familia.

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AZUZ (voice-over): Ten-second trivia:

Chronic traumatic encephalopathy is a disease associated with what organ?

The brain, the heart, the liver or the skin?

Also known as CTE, this disease is associated with repeated injuries to the brain.

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AZUZ: There`s a lot of mystery surrounding CTE, and one of the biggest medical challenges of this disease is that doctors aren`t able to diagnose it in anyone alive. They`ve had to examine the brains of dead people to confirm evidence of CTE.

But that could change, thanks to something called CCL11. It`s a protein found in the body. It`s associated with inflammation.

And a new study published in the journal "PLOS ONE" found that brains previously diagnosed with CTE also had increased amounts of the CCL11 protein. If a link is confirmed between this protein and CTE and if CCL11 can be detected in the blood, there`s a chance it could establish an indication that someone has CTE before he or she dies.

But researchers say it`s too early to know if any of this is for sure and even if a link is established, there`s no known treatment for CTE.

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DR. SANJAY GUPTA, CNN CHIEF MEDICAL CORRESPONDENT: Lately, it`s been difficult to talk about football without mentioning concussions. Why?

Well, mounting concern over disease called chronic traumatic encephalopathy, more commonly known as CTE.

SUBTITLE: What is CTE?

GUPTA: In the world of medicine, CTE is a relative newcomer. In football, we just learned about it 10 to 15 years ago.

Here`s what we can say: it`s a progressive degenerative brain disease. It is like Alzheimer`s. It can start with memory loss, mood swings, and difficulty in concentration, developing into progressive dementia, even possible thoughts of suicide.

But unlike Alzheimer`s, CTE can also result in significant aggression and lack of impulse control.

The big difference: symptoms tend to begin much earlier in life, closer to your 40s instead of your 60s. In both diseases, there is no known cure.

Researchers believe there`s only one way to get CTE and that is repeated hits to the head. What happens is that you get a build up of an abnormal protein called Tau in the brain. Scientists do know both the location of the Tau and how much Tau in the brain determines the symptoms you might exhibit.

But scientists don`t yet have a magic number of hits that results in CTE. It also isn`t known who exactly would develop CTE. There`s some players who take many hits and never develop symptoms. Factors like genetics and age of exposure to the trauma could play a role.

How do you know if you have CTE? Just because you have symptoms doesn`t mean you have the disease. In fact, as things stand now, you can only be diagnosed for sure after death. Scientists are researching how to diagnose in living people.

A prominent group of researchers have found over 90 percent of former NFL players have developed CTE. But remember something important here, the number could be so high because of something known as selection bias, that means the brains that were studied were from people who worried that they had CTE. Also, it`s not just football players that need to be concerned. Boxers, soccer players, people in the military, anyone who`s exposed to constant head trauma can develop it, too.

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AZUZ: Stan Hays has responded to more than 40 disasters across America in the past years. And that includes Hurricanes Harvey and Maria. He`s not a first responder or an expert in search and rescue. He`s a grand champion pitmaster, an expert in barbecue.

And with the help of 6,200 volunteers, Hays` nonprofit organization, Operation Barbecue Relief, has provided almost 1.7 million meals for survivors and rescuers.

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DON LEMON, CNN ANCHOR: All right. Joplin, Missouri, hit by a devastating tornado.

STAN HAYES, CNN HERO: May 2011, the Joplin tornado hit. It`s about two and a half hours from my house. I have been competing in barbecue for years. So, we decided we`re going to get a bunch of the barbecue family together and go down there and help.

A hundred and twenty thousand mills were served in 11 days. We came to a realization that we got an opportunity here to do something that could make a difference.

UNIDENTIFIED MALE: I`ll talk to you.

HAYS: Over the last six years, we responded to tornadoes, floods, hurricanes.

Heading down to Texas to Hurricane Harvey.

Our goal is always to be in an area within 24 to 48 hours after a disaster strikes.

We have water on that interstate. Holy cow, what this community is going through.

Our focus is getting it done.

Hurricane Harvey is our 42nd disaster.

Here, you got 48 more for these pork loins going on. They`re rubbing them down.

The core group are all pitmasters or grill masters. But our volunteers come from everywhere.

So, these smokers just keep rolling.

It gets in to the logistics of supplies coming in.

We`ll load those on and then come back.

We have pork, turkey, vegetables. The greatest thing really is, everybody coming together.

There`s a lot of love put into this by a lot of people that want to help.

UNIDENTIFIED MALE: That`s the whole spirit of everybody here. Let`s just get those meals into the belly of people who need it.

HAYS: We put the world out through different groups. In that way, we know where the meals are going.

Barbecue, besides being a nourishing meal, is comfort food.

Do you guys need any meals?

UNIDENTIFIED FEMALE: You have no idea what a hot meal means to somebody who`s lost everything they own. So -

HAYS: To know that you`re a little part of picking their spirits up, you can`t help but bring a smile to your face.

It`s amazing. Yesterday, you guys put out 43,350 meals. Thank you to everybody that was here.

(APPLAUSE AND CHEERS)

HAYS: It is people helping people the best way we know how.

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AZUZ: It`s one thing to call a cab. It`s another to take a seat in one of these. It`s a taxi service being tested in Dubai, United Arab Emirates.

And you`ll notice first that it flies, and second, that it has no driver. Sound a little sketchy?

Well, the Emirates crown price was the first person to try it, so that might boost confidence in the service. No word on cost yet, but the drone taxis has 18 rotors. It`s guided by GPS. It`s electric buggy, buggy, buggy. And it can take off and land vertically so there`s no need to taxi down the runway.

We`re not sure how the competition would respond if they see that thing flying Uber-head, or actually giving people a Lyft. They may call it unfair, but it could be the future of both a ride and the thrill ride, or at least the service that is literally above all the rest.

I`m Carl Azuz and this is my stop. Hop in tomorrow for more CNN 10.