The CBRE Urban Photographer of the Year competition – now in its ninth year – encourages professional and amateur photographers to capture cities at work. Here: Dog Walker – 15:00. The competition allows photographers to enter up to 24 images, one representing each hour of the day. (Photo by Johanna Siegmann)

Renowned amphibian and reptile photographer Matthijs Kuijpers has released his first book, “Cold Instinct”. Kuijpers says the aim of the work is “for the viewer to abandon the fear and negative thoughts that often surround these animals”. What’s left is the bizarre beauty of these creatures in their simplest form – no backgrounds and no distractions. Here: Mossy frog (Theloderma corticale). (Photo by Matthijs Kuijpers/The Guardian)

These images are enough to make viewers do a double-take. Although they look like vibrant works of abstract art, they are actually drone photographs taken by brothers J.P. and Mike Andrews, from near Wolverhampton, England. Here: Kickflip. (Photo by J.P. Andrews/Mike Andrews/Caters News Agency)

This 2014 series Shanghai Tian Wa saw Chinese photographer Liu Tao train his lens on two distinct districts in Shanghai. Here: “Shanghai Tian Wai №26, 2014”. (Photo by Liu Tao/The Guardian)

Ukrainian artist Dariya Marchenko works on a portrait of Russian President Vladimir Putin named “The Face of War” which is made out of 5,000 cartridges brought from the frontline in eastern Ukraine, in Kiev, July 23, 2015. The portrait will be presented along with a novel which will tell personal stories of six people involved in this project including Daria's own story and stories of people who helped her to collect shells from the frontline. Daria Marchenko calls her art approach philosophic symbolism where every element has its hidden meaning. In her works cartridges mean human's life that was brutally ended. (Photo by Gleb Garanich/Reuters)

A man speaks on his mobile phone on May 31, 2011 in New York City. In a new report by 31 scientists meeting at the World Health Organization's International Agency for Research on Cancer (WHO/IARC) it was found that using a mobile phone may increase your risk for certain kinds of brain cancers. While further scientific work will be conducted, the group of scientists from 14 countries classified cell phones in the carcinogenic category 2B, which is similar to the pesticide DDT and gasoline engine exhaust. (Photo by Spencer Platt/Getty Images)

A woman looks at photographs of dogs to choose a pet to rent at Puppy The World on January 24, 2009 in Tokyo, Japan. Rent-a-dog is becoming increasingly popular amongst people who love dogs but are unable to look after a pet full time due to limited living space or long working hours. Customers pay the dog-rental outlet around 2500 yen (32.5 USD) for an hour, and usually take their rented pet for a walk along the nearby beach. (Photo by Junko Kimura/Getty Images)