Three things you need to know today.

U.N. health meeting: For only the second time in the history of the United Nations, the General Assembly will hold a meeting on a health issue.

The body convenes in New York on Monday to discuss non-communicable diseases. Each year 36 million people worldwide die of non-communicable diseases, the World Health Organization reports. Those include cancer, diabetes, heart attacks and strokes and chronic respiratory disease. That's 63% of all deaths worldwide, the agency says.

The aim of the two-day U.N. conference is "to adopt a concise, action-oriented outcome document that will shape the global agendas for generations to come," according to the WHO's website.

Eighty percent of deaths from non-communicable diseases occur in low- or middle-income countries, the WHO says. On Sunday, the organization released a study saying that low-income countries could introduce strategies and treatments to fight non-communicable diseases that would cost just $1.20 per year per person. Some of those strategies include anti-smoking campaigns, reduce salt content in food and public awareness programs about diet and physical activity.

Troy Davis hearing: Georgia's parole board will convene Monday morning to hear a last-minute appeal by Troy Davis, who is set to die by lethal injection for the murder 21 years ago of a Savannah police officer.

A jury convicted Davis of murder in 1991, paving the way for his execution, which has been delayed three times and is now scheduled for 7 p.m. Wednesday at a state prison in Jackson, Georgia.

The Georgia Board of Pardons and Paroles noted in a press release Sunday it is "the sole authority in Georgia for granting clemency to inmates." Options for the board include commuting a death sentence without parole, giving a convict a life sentence or denying clemency - which, in this case, would pave the way for Davis' execution.

Its closed meeting will start at 9 a.m. Monday in a state office building in Atlanta.

Home-invasion killings: Joshua Komisarjevsky goes on trial in Connecticut on Monday in the 2007 home-invasion killings of Jennifer Hawke-Petit and her daughters - 17-year-old Hayley Petit and 11-year-old Michaela Petit. Dr. William Petit, Hawke-Petit's husband and the girls' father, was beaten and tied up at the beginning of the attack before he managed to escape.

In December, Steven Hayes was sentenced to death after being convicted on 16 of 17 charges related to the killings.

Hayes forced Hawke-Petit to go to a bank and withdraw $15,000 from an account after finding evidence the account held between $20,000 and $30,000, authorities said.

Prosecutors allege that Hayes and Komisarjevsky went into the home, beat and tied up Petit, raped and strangled his wife, molested one of their daughters, then set their house on fire before attempting to flee.