‘Bacterial signatures’ from genital areas could serve as a forensic tool to identify perpetrators of sexual assault, even if there is no trace of sperm, according to a study published in the journal iScience, by the Cell group. After sequencing the DNA of bacteria from genital samples from 12 stable couples, the authors show that a transfer of bacterial species occurs during intercourse, allowing the identification of each person’s own genital microbiome or ‘sexome’.

An international team of scientists from the KM3NeT collaboration has detected the signal from the highest-energy cosmic neutrino to date, some 30 times higher than those previously detected. The result suggests that the particle came from beyond the Milky Way, although its precise origin has yet to be determined. The results are published in the journal Nature. 

Two papers published in Nature Climate Change analyse the possibility of exceeding the Paris Agreement targets of limiting warming to 1.5°C above pre-industrial temperatures. Both papers suggest that having exceeded this warming threshold by 2024 could indicate that we have entered a period of several decades with average global warming of 1.5 °C. According to the authors, rigorous climate mitigation efforts are needed to keep the Paris Agreement targets within reach.

A study in 2024 described how the Earth's core had slowed down its rotation speed in recent decades. Now, the same international team of scientists adds that its shape has also changed over the last two decades. Until now, it was thought that both processes could not occur simultaneously. According to the researchers, who publish the results in the journal Nature Geoscience, the finding could improve our knowledge of the core's properties and structure.

Every 11 February is celebrated as World Medical Women's Day, which coincides with the International Day of Women and Girls in Science, although its commemoration refers to Elizabeth Blackwell, the first woman to obtain a medical degree in the USA, in 1849. More than a century and a half later, despite the increasing number of women graduates, inequalities persist in the profession, especially in senior positions.

Toddlers' screen time has a negative correlation with their language skills, according to a study published in PLoS ONE. However, the use of educational content and screen time in the company of adults show a positive association with language skills. The study included nearly 1,900 children between one and four years old from 19 Latin American countries.

Thousands of people congregate at the San Fermín festival in Pamplona. By analysing camera images from the Plaza Consistorial during the chupinazo in four editions, a team has modelled what the movement of this human tide looks like. The physical theory of dense crowds can be applied in other circumstances, say the authors, who include scientists from the University of Navarra. In their paper published in Nature, they offer a strategy to anticipate these movements in real time and help prevent events such as avalanches.

The report Participation of women scientists as expert sources in the media: motivations and obstacles, carried out by FECYT's SMC España with the Gureiker research group (UPV/EHU) analyses the data from a survey, a pioneer in Spain, on the factors that influence the media participation of scientists as expert voices. All the people contacted as information sources by the SMC Spain team were surveyed over a three-month period, starting in March 2024. Of the sources consulted, 43.91% were women and 56.09% were men. However, of the total number of people who accepted SMC's proposals and appeared as sources, 37.66% were women and 62.34% were men. The greater media exposure of male scientists benefits them for future interventions. In terms of barriers that prevent researchers from speaking in the media, lack of time due to family responsibilities affects female scientists (22.95 % of respondents) more than male scientists (10 %).  

A paper published in The Lancet Respiratory Medicine has analyzed new cases of lung cancer worldwide during the year 2022. While the incidence in women continues to approach that of men, the decrease in tobacco consumption in many countries causes the proportion of cases in non-smokers to increase. This increase is associated with air pollution, especially in countries such as China. 

A multidisciplinary team of US researchers has analyzed the presence of micro- and nanoplastics in 52 human cadavers between 2016 and 2024. The concentrations of these particles were higher in the brain than in the liver or kidneys. They were also higher in the brains of people with dementia, although the researchers acknowledge that causality cannot be established. The results are published in the journal Nature Medicine.