What the sci­en­tists are say­ing…

The Week - - Health & Science News -

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.

A Ja­panese sea star found in Ore­gon in 2012

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