A period of relative stability has put the Iranian capital No1 on the list of world cities that have achieved biggest improvements in liveability over the past five years, as calculated by the Economist Intelligence Unit. The “most improved” top 10 contains some unexpected names. So, eg, the fourth place: Abidjan, Ivory Coast. Latest ranking: 128; Ranking five years ago: 131; Five-year index movement: 3.8%. Here: A supporter of Ivory Coast president Alassane Ouattara campaigns in a market in the city’s Koumassi quarter. (Photo by Sia Kambou/AFP Photo)

Darth Mykolaiovych Vader, who is dressed as the “Star Wars” character Darth Vader, poses for a picture as he dries his mask and helmet with a hairdryer in the bathroom of his apartments in Odessa, Ukraine, December 2, 2015. Darth Vader was bent on galactic domination, but his Ukrainian namesake enjoys more mundane pursuits: local politics, walking the family dog and a spot of embroidery. The Ukrainian citizen, who has changed his name to Darth Mykolaiovych Vader, ran for the post of local mayor in October, his political backers dressed as Stormtroopers. In his trademark black outfit, he is a regular sight around Odessa, a major port city on southern Ukraine's Black Sea coast. (Photo by Valentyn Ogirenko/Reuters)

Girls of the Long Horn Miao ethnic minority group wear headdresses as they prepare gather for Tiaohua or Flower Festival as part of the Lunar New Year on February 6, 2017 in Longga village, Guizhou province, southern China. (Photo by Kevin Frayer/Getty Images)

An adorable baby koala is seen enjoying a snooze after a traumatic start to life. The baby koala, nicknamed “Blondie Bumstead”, is being cared for by a volunteer from the Ipswich Koala protection society in Queensland after her mother was killed by a dog. Blondie, who was named for her light fur, was given just a 50-50 chance of pulling through after the attack. But after a course of antibiotics and some tender loving car from volunteer Marilyn Spletter she has now been given a clean bill of health. According to Marilyn she has hand-reared around 40 baby koalas but says that Blondie, who will be released back into the wild after 15 months, is one of her favourites. She said: “She's got a little character all of her own and she knows what she wants and what she doesn't. When she's stressed I kiss her on the nose or I rub my nose on hers and it relaxes her”. (Photo by Jamie Hanson/Newspix/REX Features)

These black-and-white photos are taken from the new book “Armoured Warfare in the First World War 1916 – 1918” by Anthony Tucker-Jones and published by Pen & Sword Military. Here: British troops hitch a ride on a Mark IV after the massed tank fleet spearheading attack at Cambrai on November 20, 1917. (Photo by Anthony Tucker-Jones/Mediadrumworld.com)

The National Geographic Photo Ark is a travelling exhibition of photographer Joel Sartore’s quest to create a photo archive of biodiversity around the world. So far, Sartore has captured studio portraits of more than 6,000 species – a number that he hopes to double. On 1 July, the ark will open at Melbourne zoo – the first time it has been exhibited in the southern hemisphere. More than 50 portraits will be on display, including many of Australian endangered animals being protected by programs at the zoo itself. These captions have been edited from text supplied by Melbourne zoo. Here: Barking owl. (Photo by Joel Sartore/National Geographic Photo Ark/The Guardian)

“The ONE Campaign is a international, nonpartisan, non-profit organization which aims to increase government funding for and effectiveness of international aid programs. ONE was originally founded by a coalition of 11 non-profit humanitarian and advocacy organizations — including DATA, World Vision, Oxfam America, and Bread for the World — with funding from the Bill & Melinda Gates Foundation. In 2007, ONE announced that it would be merging with DATA. Currently, ONE is campaigning for resources to help developing countries adapt to climate change. During the 2008 U.S. presidential election the organization launched a campaign, called ONE Vote '08, which was co-chaired by former U.S. Senate majority leaders Tom Daschle (D-SD) and Bill Frist (R-TN). The campaign is named after the U2 song “One” which was a top ten hit single on the critically acclaimed 1991 Achtung Baby album”. – Wikipedia

Photo: Bill Gates, founder of Microsoft and now philanthropist, poses with One.org charity volunteers at Pariser Platz square during a brief stop at Brandenburg Gate on April 6, 2011 in Berlin, Germany. Gates is in Berlin to meet with German government officials, including Chancellor Angela Merkel and Development Minister Dirk Niebel, to discuss aid for developing countries and promote his One.org charity initiative, which is part of the Bill and Melinda Gates Foundation. (Photo by Sean Gallup/Getty Images)