We compared semen analyses of 45 patients before and after mild covid-19 infection. We found a significant decrease in sperm volume, sperm concentration, total and progressive motility and vitality after infection, and that these effects may be long-term.

The latest episode of competition between research groups working on the same topic, a very common situation in science, should not distract us from the actual achievement: synthetic human embryos, in the laboratory, made from stem cells, up to a post-implantation stage. Now, we must decide what status or condition we will grant to these synthetic embryos. Once again, science is leaping forward and testing the limits of the laws, posing new ethical challenges for us to solve. 

The current situation is only the beginning of what may come in the coming decades, which should lead us to increase efforts in mitigation and adaptation strategies: more green and shaded areas, energy efficiency in buildings and avoiding working outdoors in extreme temperatures.

This year's theme for 8M is "For an inclusive digital world: innovation and technology for gender equality". If we want to innovate for everyone, there must be women doing research in mathematics, an essential discipline in the fields of technology, finance and health. However, the future of mathematical research in Spain has a male profile and this is worrying: advances and major decisions will be made excluding half of the population.

Faults can generate the most devastating earthquakes. The East Anatolian fault, where the earthquakes in Turkey and Syria occurred on 6 February, has been rupturing quite frequently - every few decades to hundreds of years. Seismic hazard maps are used to design buildings and infrastructure to withstand strong shaking during an earthquake. Reinforced concrete buildings with earthquake-resistant designs are the most appropriate, but often unaffordable for certain regions.

Nature's ban on publishing papers written by ChatGPT has brought several debates to the table: is it ethical to use it to produce science texts, and if so, should it sign them? Just as we don't make the Word proofreader a co-author of our articles, let's not make fools of ourselves by giving these new tools the status of co-authors as if they had an entity of their own.

In January 2013, two laboratories demonstrated that CRISPR tools could be used to edit genes in human cells. Ten years later, the first patients are already benefiting from the molecular scissors to overcome incurable diseases. This week in Science, one of the pioneers of CRISPR, Nobel laureate Jennifer Doudna, summarises the history of these tools, without forgetting that it all began thirty years ago with the findings of Francis Mojica in the Santa Pola salt flats.

Since records have been kept, the year we are about to end has been the warmest in Spain. Added to this is a severe meteorological drought and the numerous and powerful wildfires that we record in summer. Adapting our society to these extreme events as a consequence of climate change should be a top priority.

After the World Cup in Qatar, National Microbiology Centre researcher María Iglesias wonders where the social alarm about an alleged outbreak of MERS came from and takes the opportunity to explain some concepts of the virus and its surveillance.

After almost three months of delays caused by various technical problems and two hurricanes, the Artemis I mission was successfully launched this morning, the first of a programme that will take the first woman astronaut to the moon. It has 42 days ahead of it, during which the spacecraft will orbit our satellite and test the stability of this lunar orbit, because in the future a space station will be located there to receive the astronauts on their journey from Earth.