What the scientists are saying…
Globe-trotting bed bugs That infestations of bed bugs have soared in recent years, fuelled by the growth of low-cost international travel, is well established. But something has long puzzled scientists: the creepy-crawlies, which are a problem in hotels in particular, prefer to keep a low profile, hiding in mattresses or in the crevices of sofas – so what possesses them to venture out into travellers’ suitcases? Now a team at the University of Sheffield has come up with an answer. Bed bugs are attracted to soiled clothes (presumably because it has the residual odour of the humans whose blood they feast on). For the study, researchers at Sheffield placed open bags of soiled and non-soiled laundry in two identical rooms that contained an equal number of bed bugs. After a few days, far more bugs had congregated in and around the bags of soiled laundry than the clean ones. For travellers hoping not to bring bugs home, the solution is obvious: keep your dirty clothes in a sealed bag.
Sea animals and plastic rafts The Japanese tsunami of 2011 prompted the biggest continental migration of sea creatures ever recorded, scientists have discovered. Since 2012, nearly 300 living species – including mussel, worms, crustaceans and sea slugs – have been found off North America’s Pacific coast still attached to debris, such as pieces of buoys, crates and vessels, swept out to sea by the tsunami. Of these, more than twothirds had never previously been seen in the US. The scientists believe that the creatures survived because the slow progress of their “ocean rafts” gave them time to adjust to their new environments. However, it is as yet unclear whether any have actually colonised North American waters or what their long-term impact on native species could be. According to the report, published in the journal Science, such migrations are likely to become more common even without further tsunamis, because of the sheer volume of man-made material in the sea. A 2015 study, also published in Science, estimated that around ten million tonnes of plastic waste enter the ocean each year – a figure that is likely only to increase in coming decades.
Half of abortions “unsafe” Of the 56 million abortions each year, nearly half – 25 million – are unsafe, according to a report published in The Lancet. Researchers from the World Health Organisation (WHO) and the Guttmacher Institute in New York looked at abortions performed worldwide between 2010 and 2014, and divided them into three categories – safe, less safe and least safe – based on what procedures were used and whether a trained provider was involved. Less safe procedures, which accounted for 17 million per year (31%), were ones that used an outmoded method but were provided by a trained person, or which used a safe method but without professional oversight. The largest proportion of procedures in this category took place in Latin America, and involved women using the labour-inducing drug misoprostol – which is approved by the WHO – but doing so outside formal medical channels. The eight million (14.4%) “least safe” abortions were performed by, for instance, consuming toxic substances or inserting wire into the uterus, and were carried out by untrained providers; most of these took place in Africa. The report warns that Donald Trump’s reinstatement of rules blocking US aid to agencies which perform abortions, or offer advice on them, is likely to lead to yet more unsafe abortions.
The foods that make you full It has long been known that some foods trick the brain into feeling full, but scientists have never been clear about the chemical pathways involved. Now, researchers at the University of Warwick have identified an appetite-regulating brain cell that switches on immediately when certain foods are consumed. Using fluorescent tagging, the team discovered that the brain cells, known as tanycytes, are activated within 30 seconds of certain amino acids touching the tongue. The finding suggests that people seeking to lose weight should eat the high protein foods that are rich in these key amino acids – including pork shoulder, chicken, mackerel, lentils and almonds – and could lead to the development of new appetite suppressant drugs that target tanycytes.