Scientists

A team from the United States analyzed 611 samples from 341 model mouse strains stored at the Mutant Mouse Resource and Research Centers (MMRRC), a research resource network supported by the National Institutes of Health (NIH). By comparing the identity of each strain with its actual genetic profile, they found that approximately half of the samples showed discrepancies. Although the expected engineered mutation was generally present and many inconsistencies were relatively minor, some had the potential to compromise the validity and reproducibility of the experiments by introducing hidden genetic variables that could alter biological outcomes. The findings are published in Science.

The eyes are connected to the brain via the retina, which makes it a potential pathway for brain stimulation. A study published in Cell Reports Physical Science has used contact lenses equipped with a system for transcorneal electrical stimulation to treat depression in animal models of the disorder. Mice fitted with the device showed behavioural improvements, including increased sociability, as well as physiological changes, such as the restoration of altered neural connections. The results were comparable to those obtained with fluoxetine —known commercially as Prozac— administered for three weeks in one of the mouse groups.

An analysis by World Weather Attribution shows that players and fans face a much higher risk of extreme heat and humidity at the 2026 FIFA World Cup—to be held from June 11 to July 19 in North America—compared to the 1994 tournament held on the same continent. The report analyzes the likelihood that each of the 104 matches to be played in Canada, the United States, and Mexico will meet the safety guidelines set by the FIFPRO players’ union. Nearly a quarter of the matches will be played when conditions exceed a wet-bulb temperature of 26°C—an index that measures the body’s ability to cool itself—which requires cooling breaks. In addition, five matches will exceed the 28°C threshold for this indicator—equivalent to 38°C in dry heat—a limit set by FIFPRO for postponing matches.

A research team presents a wireless polygraph – colloquially known as a “lie detector” – that attaches to the chest to diagnose stress in adults and sleep disorders in children. According to the study, published in Science Advances, the device is able to identify episodes of waking, hypopnoea and apnoea in children.

A team has proposed an indicator known as the plastic particle footprint (PPF) to measure the environmental impact of microplastics and nanoplastics in products. In an article published in Science Advances, the authors apply this calculation to four everyday items and claim that calculating this footprint could “radically change the best material option”. For example, a polyester T-shirt and a cotton one have a similar carbon footprint, but the PPF of the former is higher than that of the cotton garment.

A global analysis of data from more than 232 million people shows that the rise in obesity has slowed or stabilised in some high-income countries since the 1990s among children and adolescents, and, a decade later, among adults. In Spain, this stabilisation or even a slight decline is also observed. In most low- and middle-income regions, the prevalence of obesity continues to increase and, in some cases, has already surpassed that of more developed economies. The study, published in Nature, included 4,050 studies covering the period from 1980 to 2024 across 200 countries.

A study conducted by the Barcelona Institute for Global Health (ISGlobal), in collaboration with the Barcelona Supercomputing Center (BSC-CNS), has analyzed short-term mortality associated with the combined effects of multiple air pollutants in 31 European countries. According to their estimates, this exposure is associated with 146,500 premature deaths per year and affects people differently depending on age, sex, and cause of death: young men are more vulnerable than young women, but the pattern reverses with age. The authors, who published the study in Nature Health, propose creating a new generation of impact-based early warning systems specifically targeting vulnerable groups.

In the treatment of obesity, maintaining weight loss is the most difficult phase. Two independent clinical trials published in Nature Medicine have adopted two different strategies to achieve this. The first is a phase 3b trial involving the GLP-1 drug orforglipron, administered orally on a daily basis for 52 weeks. This trial included 376 adults in the United States who had already completed 72 weeks of injectable treatment with tirzepatide or semaglutide. Almost 75% and 80% respectively of patients on each injectable drug maintained their weight loss. The second trial involved 90 obese adults from the Netherlands who followed a low-calorie diet for eight weeks and then received a daily supplement of the bacterium Akkermansia muciniphila for 24 weeks, alongside a healthy diet. Although those who received the supplement regained more than 13% of the weight initially lost, those who took the placebo regained almost 33%.

Why do eclipses occur? Is the Earth’s shadow responsible for the phases of the Moon? Is the Moon full during a solar eclipse? These are by no means obvious questions, yet they are extremely useful in teaching astronomy for identifying the obstacles we encounter when thinking about celestial mechanics, regardless of age or educational background. Here are several suggestions for untangling the most common misconceptions and understanding the cosmic dance of the stars as seen from Earth.

Amid an unprecedented international security and coordination operation, the MV Hondius has arrived at the port of Granadilla, in Tenerife, where epidemiologists and members of the Foreign Health Service will examine the passengers and crew, who have not shown any symptoms of hantavirus so far. Once assessed, they will leave the ship, which is moored in a dock, in small boats to the port, grouped by nationality – they come from 23 different countries. From there, they will board military vehicles to reach Tenerife South Airport, from where they will be repatriated on various flights. The 14 Spaniards and a member of the WHO from Africa are bound for Gómez Ulla Hospital (Madrid) to undergo quarantine. Once the process is complete, the cruise ship will refuel and sail to the Netherlands with part of the crew on board and the body of one of the three fatalities.