Houthi followers perform the traditional Baraa dance ahead of a demonstration against the Saudi-led air strikes in Yemen's capital Sanaa August 24, 2015. The nothern-based Houthis, a Shi'ite Muslim group, took control of Sanaa last September. Arab countries intervened in the conflict in March to halt a Houthi advance into the south which caused the Saudi-backed government to flee to Riyadh from its refuge in the southern port of Aden. (Photo by Khaled Abdullah/Reuters)

Dajana Djuric, 25, who has worked as a chimney sweep since the age of six, cleans a chimney in Brcko, Bosnia and Herzegovina. Dajana Djuric, believed to be the only female chimney sweep in Bosnia and Herzegovina, has to contend with perilous roofs in the depth of winter. (Photo by Dado Ruvic/Reuters)

An altar is pictured after it was decorated by the Antar family with some 3,000 traditional cheese and corn buns called “chipas”, in celebration of Kurusu Ara in Asuncion May 3, 2015. Kurusu Ara, the Day of the Cross, is a Catholic festival that is combined with local Gurani culture and falls annually on May 3. Paraguayans typically celebrate the festival with chipas, used to decorate religious shrines and altars. The chipas are later distributed to attendees. The buns at the top are arranged to read, “March 3 live”. (Photo by Jorge Adorno/Reuters)

“A series of ads, developed as a creative idea for UN Women by Memac Ogilvy & Mather Dubai, uses genuine Google searches to reveal the widespread prevalence of sexism and discrimination against women. Based on searches dated 9 March, 2013 the ads expose negative sentiments ranging from stereotyping as well as outright denial of women’s rights”. – UN Women. (Photo by Ogilvy & Mather, Dubai, UAE/UN Women)

In a north London hospital, scientists are growing noses, ears and blood vessels in the laboratory in a bold attempt to make body parts using stem cells. It is among several labs around the world, including in the U.S., that are working on the futuristic idea of growing custom-made organs in the lab. (Photo by Matt Dunham/AP Photo)

Buildings are seen near the ocean as reports indicate that Miami-Dade County in the future could be one of the most susceptible places when it comes to rising water levels due to global warming on March 14, 2012 in North Miami, Florida. Some cities in the South Florida area are starting to plan for what may be a catastrophic event for the people living within the flooding area. (Photo by Joe Raedle/Getty Images)

Armless professional photographer Rusidah, 44, takes a photograph as she carries out camera maintenance on March 13, 2012 in Purworejo, Indonesia. Rusidah shoots weddings and parties and has a small studio at home in the village of Botorejo, Bayan District, Purworejo, Central Java where her husband and son also reside. She has been in the photography business for nearly 20 years. (Photo by Ulet Ifansasti/Getty Images)

David Rawcliffe, house and monument steward at the National Trust's Chedworth Roman Villa cleans a Roman mosiac in the new environmentally-controlled conservation shelter on March 19, 2012 near Cirencester, England. Opened this month, the multi-million pound building allows visitors to walk on suspended walkways just above the 1600-year-old Roman floors and to see recently excavated mosaics not seen for 150 years, with more to be uncovered over the coming year. (Photo by Matt Cardy/Getty Images)