Complutense University of Madrid

According to a report published yesterday in The New York Times, most of the members of the Subcommission on Quaternary Stratigraphy had rejected the proposal to declare the beginning of the Anthropocene, thus showing their opposition to the idea that this is a new geological epoch. Other sources told El País that the result of the vote was not formally confirmed. If this proposal is defeated, the process could be restarted from scratch at a later date.

At an informative meeting organized by the Science Media Centre Spain, the coauthor of a paper published this week in the journal Cell discussed his findings with journalists. Although the study was conducted with mice, he is confident in being able to analyze human eggs to see if his conclusions could explain the loss of fertility that occurs in women with age.

An international team, led by a Spanish group, has published the mechanism that allows immature egg reserves (oocytes) to survive for many years, up to almost half a century in the case of humans. The research studies how oocytes are affected by protein aggregates similar to those that damage other cells such as neurons and can cause neurodegenerative diseases such as Alzheimer's disease. The finding of how these egg reserves are kept healthy may help to understand some causes of infertility. The results are published in the journal Cell.

This week, Spain’s Ministry of Health launched a process to develop a Royal Decree on the medical use of cannabis, assuring that it will be "a rigorous measure based on the best scientific evidence available.” The goverment is conducting a public consultation until 4 March to gather the opinions of citizens, civil society organisations, professional associations and scientific societies. In this explainer, we attempt to answer the main questions that arise regarding the medical use of cannabis. 

A team of researchers has demonstrated how a non-invasive ultrasound technique can increase the movement of human sperm in the laboratory by up to 266%. Using microfluidic droplets to evaluate individual sperm cells, which had not been done before, they found that ultrasound exposure induced movement in immobile sperm and improved swimming speeds in mobile ones. The work is published today in the journal Science Advances.

In an anonymous online survey of dog owners in Denmark, 38% of respondents said they administered cannabinoid products - such as cannabidiol drops - to their pets without a prescription, even though their use is not legal in animals. Reasons given included pain, behavioural problems and allergies in their dogs. Some 2,000 people responded to the survey, the results of which are published in the journal PLoS ONE.

Fifteen years ago, the European Space Agency's (ESA) Mars Express probe revealed the presence of large deep deposits on Mars, in an area called the Medusae Fossae Formation (MFF), located at its equator. Now, new data from the probe's MARSIS radar indicate that the deposits are deeper than previously thought - up to 3.7 kilometers thick - and include both ice-rich and dusty layers. The results are published in Geophysical Research Letters.

A study carried out in two hospitals in Denmark has compared the brain health of 120 patients admitted for covid over 18 months with that of other hospitalized patients with similar severity due to pneumonia, heart attack or need for intensive care, as well as with healthy people. The conclusions are that patients with covid worsened with respect to the latter, but did so in a similar way to other hospitalized persons. According to the authors, "although studies are needed to confirm these findings, brain health after covid-19 appears generally comparable to that of other diseases of similar severity."

Babies' brains specialise in their native language from pregnancy, according to a study carried out in France. The research team used encephalograms to measure the brain activity of 33 infants born to French-speaking mothers while listening to a story in French, English or Spanish. The results provide "the most compelling evidence to date that language experience already shapes the functional organization of the infant brain, even before birth," the authors write in Science Advances.

A review of 25 studies conducted over nearly 50 years has found an association between insecticide exposure and lower sperm concentration. According to the authors, "insecticides are a public health concern for all men, who are exposed mainly through consumption of contaminated food and water". The results are published in the journal Environmental Health Perspectives.