Read the best science news from around the world this week
Male contraceptive trail 100 per cent effective
A male contraceptive gel, that is set to rival reversible vasectomies and condoms as a viable contraceptive alternative, has been found to be 100 per cent successful in monkeys. The expected pregnancy rate under normal conditions is 80 per cent but no pregnancies occurred during the six-month trial. Vasalgel™ is injected into the vas deferens, the tubes through which sperm travel from the testes to the penis. The gel acts as a barrier to prevent sperm from moving. The non-toxic and non-hormonal gel is also reversible, as it can be dissolved using ultrasound.
Alien worms destroy African farms
The fall army earthworm is spreading rapidly across Africa, ruining maize crops and putting farmer’s livelihoods at risk. Scientists have called for urgent action as the spread could be harmful to food security and agricultural trade. The worm is not native to the continent, and is thought to have been brought over from North or South America. Dr Matthew Cook, of Cabi, has said: “This invasive species is now a serious pest spreading quickly in tropical Africa and with the potential to spread to Asia. Urgent action will be needed to prevent devastating losses to crops and farmers’ livelihoods.”
Mexican car ban fails to improve air pollution levels
Scientists have found that banning cars on Saturdays in Mexico City, in a bid to reduce vehicle emissions by at least 15 per cent, has been unsuccessful. According to the new study, residents avoided the restrictions by carpooling, using taxis, and purchasing extra vehicles. The system is based on number plates, so only certain cars can drive. Mexico City was once named the world’s most polluted city, in 1992. The city’s pollution problem sees thousands of people hospitalised every year with related health issues.
Injection could permanently lower cholesterol
A new injection replicates a natural mutation that causes people to have a lower risk of heart disease, without unwanted side effects. The mutation means the PCSK9 protein is produced, which lowers cholesterol levels. This permanent change to DNA is yet to be tested on humans. Heart-related problems, often caused by high levels of cholesterol, are responsible for a quarter of deaths each year. For now, Dr Lambert, of the pioneering team, says the idea is still ‘very far-fetched’ and a decade off from being successful in humans.