Now celebrating its 40th year, Nikon Small World is widely regarded as the leading forum to recognize proficiency and photographic excellence of photography taken under the microscope. To select the winners, competition judges analyzed entries from all over the world covering subjects ranging from chemical compounds to up-close-and-personal looks at biological specimens. The 2014 winners will be revealed on October 30th. In 2014, the competition received over 1,200 entries from more than 79 countries around the world. (Photo by Dr. Igor Robert Siwanowicz/Nikon Small World 2014)

As the world marks the International Day of the Girl Child, women's rights activists point to progress on a wide array of issues but say more needs to be done to protect girls from child marriage, sexual assault and other forms of exploitation. Here is a selection of pictures showing the daily lives of girls across the globe, all taken by female Associated Press photojournalists. Here: In this December 14, 2015, file photo, a young clown rides in the back of a car following a procession to the Basilica of Our Lady of Guadalupe in Mexico City. Hundreds belonging to various clown associations made their annual pilgrimage to the Basilica to pay their respects to the Virgin of Guadalupe, Mexico's patron saint. (Photo by Rebecca Blackwell/AP Photo)

The Northern Lights glow green in a spectacular light show above a field of trees frozen solid with snow. (Photo by Jaak Sarv/Solent News & Photo Agency)

A young oriental small-clawed otter at the zoo in Neumuenster, Germany, March 5, 2014. The six young otters (one male, five female) were born on December 7, 2013. (Photo by Maja Hitij/EPA)

Legend by Damien Hirst in the gardens of Chatsworth House on September 9, 2011 in Chatsworth, England. The never before seen work by Hirst is part of the Beyond Limits exhibition of modern and contemporary sculpture displayed in the gardens of Chatsworth by Sotherby's between 9th September to 30th October 2011. (Photo by Christopher Furlong/Getty Images)

Opposition protesters take to the streets of Moscow. Mass meeting in Bolotnaya Square on December 10, 2011 in Moscow, Russia.

Photo by: Stas Sedov and Dmitry Chistoprudov; Source: AirPano

Performers wait for delegations to arrive for traditional nomadic Naadam festival performance during the Asia-Europe Meeting (ASEM) summit just outside Ulaanbaatar, Mongolia, July 15, 2016. (Photo by Damir Sagolj/Reuters)

These tiny insects are so well camouflaged it is nearly impossible to make out their cleverly disguised forms. Canadian photographer and adventurer Paul Bertner attempted to catch the bugs in their natural habitats as part of a hide-and-seek game to show biodiversity in nature. Here: Stick insects. (Photo by Paul Bertner/Caters News)