A young girl smiles as teacher Damisa Rahila praises the girl in front of the rest of the class in Sakwatawa, a small community near Keffi in Nasarawa state, Nigeria. The school, which holds classes under a mango tree for younger students and inside an old building for older students, has about 75 students.

Ayanda Mathebula sweeps outside her family's home in Mamelodi, South Africa. She dreams of becoming a social worker but first she must pass her last two matric exams, which she failed before. She sometimes finds it hard to study because she must care for her two younger sisters and two younger boy cousins. Ayanda's mom died when she was 12. Her grandmother, the sole breadwinner, leaves for work at 4 a.m. "I find at home things are a bit overwhelming and then sometimes I don't find enough time to study," Ayanda said.

Haymanot Aimro prepares to feed supper to her nine-month-old son Bokallu Mosfon in Guraghe zone, Sodoo district, Ethiopia. Earlier in the day, Bokallu received his last of nine mandatory childhood immunizations. Ethiopia and 13 other countries are strengthening their immunization systems and increasing advocacy for those systems under a Gavi grant administered by Catholic Relief Services.

Aasima Hajja Spruill readies her children Avemaria, 4, and Zaheir, 2, for school in Norfolk, Va. Aasima hopes that with her small family, she can break the cycle of poverty and abuse that she grew up with.

A schoolgirl pulls down the Democratic Republic of the Congo flag at a primary school on Idjwi Island. Idjwi, which is in the middle of Lake Kivu between Rwanda and the mainland DRC, has been a safe haven for the past 30 years for people fleeing violence in both countries. The island is peaceful but lacks paved roads, electricity, water and strong social services such as healthcare and education for its 220,000 residents.

An American flag hangs off the side of the Pentagon at the opening of the Pentagon 9/11 Memorial in 2008.

People leaving the “We Are One” concert, a free Obama pre-presidential inauguration event at the Lincoln Memorial, look up at snipers on top of the Old Executive Office Building in Washington, D.C., on Saturday, January 18, 2009.

Demographic shifts in Mexico mean that over the long term, fewer young people — like these high schoolers in San Miguel Huautla, Oaxaca — are entering the workforce. This also means that fewer young Mexicans who can’t find jobs will go to the United States.

Therese Umuhire, 35, sifts sorghum in front of her home in Nyamirambo village, Rwanda. Umuhire is a member of a local coffee farmers cooperative that aims to help small-time coffee growers support themselves and their families with other enterprises even if the coffee business isn't thriving. In Therese’s case, she brews and sells sorghum beer.

Tohomina Akter washes pots and dishes in a pond near her home in Char Baria, Barisal, Bangladesh.

Choir members pull on their robes before mass at The Shrine of Our Lady of Sorrows in Kibeho, Rwanda. This is the only Marian shrine in Africa sanctioned by the Catholic Church.

Florence Bayisenge, 16, was moved out of Mpore Pfefa Orphanage after six years and has lived with her foster mother, Pauline, in Kigali, Rwanda, for eight months.

Helen helps Desire put on her shoes at Omoana House, a residential rehabilitation center for malnourished children in Njeru, Uganda. The older kids pitch in with caring for the younger kids, often treating them like siblings. Once the children are recovered, they return to living with their parents or guardians.

A mother holds her child while listening to Juliette Mukayinga, a research nurse for the Kabeho study, as she asks questions at the Remera Health Center in Kigali, Rwanda. Mothers meet with their respective study nurses once a month to answer a series of questions about their health and their child's health and nutrition.

The Elizabeth Glaser Pediatric AIDS Foundation is partnered with the Rwandan government to study the connection between nutrition and the prevention of mother-to-child transmission of HIV in 608 HIV+ mothers and their children. Globally, nearly 700 children become infected with HIV daily. About 90% of those infections are from mother-to-child-transmission, in which the virus is passed from an HIV positive mother during pregnancy, childbirth or breastfeeding.

People watch a screening of "Rooster Says," an original animated film by Africa Digital Media Academy, and "Open Heart," a documentary by Cori Stern, in Bugesera, Rwanda.