Klotho is a protein whose concentrations tend to decline with age and which has been linked to ageing processes. Now, researchers have found that administration of the protein improves cognitive function in aged rhesus macaques, including benefits in spatial and working memory. According to the authors, who publish the results in the journal Nature Aging, its use "may be therapeutic in humans".

The IceCube neutrino observatory, built deep under Antarctic ice, has detected the emission of high-energy neutrinos from within the Milky Way. According to the research, published in the journal Science, this is the first time scientists have obtained solid evidence for the emission of these particles within our galaxy, as they had previously identified high-energy neutrino emission from extragalactic sources.

The International Pulsar Timing Array (IPTA) consortium has discovered evidence for the existence of a cosmic background of gravitational waves. The results, published by different IPTA consortia in several scientific journals, would show that this cosmic background would be the result of collisions of supermassive black holes. In 2015, researchers from the LIGO and Virgo collaborations made the first direct observation of gravitational waves caused by the collision of two stellar-mass black holes. These waves oscillate several times per second. What the consortia have now found are gravitational waves emitted by supermassive binary black holes at the centre of galaxies, waves that oscillate on timescales of many years.

Reuters has reported that aspartame, one of the most common artificial sweeteners, will be listed as "possibly carcinogenic to humans" by the International Agency for Research on Cancer (IARC), an agency of the World Health Organisation, in July.

The use of hormonal replacement therapy (HRT) for menopause is associated with the development of dementia and Alzheimer's disease, even for short prescriptions before the age of 55, according to an analysis of data from the Danish national registry published in The BMJ. The research - which observes associations and cannot determine causality - also shows that the use of progesterone alone and vaginal oestrogen are not associated with the development of dementia.

Pre-exposure prophylaxis (PrEP), which usually consists of taking a daily oral anti-HIV drug, is a highly effective measure to prevent HIV infection. However, it only works well if people strictly follow the protocol, and some people end up not adhering to it. To improve this situation, researchers have tested an implant under the skin of non-human primates that releases the antiretroviral drug islatravir and maintains adequate concentrations for at least 20 months. The results, published in the journal Science Translational Medicine, show complete protection against infection with repeated exposure.

Living near green spaces over a long period of time is associated with better health, an association more marked in women and white people than in men and black people, according to a study conducted in four US cities. The analysis concludes that exposure to urban green space between 1985 and 2006 is associated with slower epigenetic ageing, and that this association is stronger in disadvantaged neighbourhoods. The international team publishing this paper in Science Advances includes a researcher from ISGlobal in Barcelona. 

Although outbreaks of H5N1 avian influenza have reached record numbers in recent years, human infections remain anecdotal. A study published today in Nature identifies a protein responsible for inhibiting the replication of this virus in humans, while 'human' flus are able to evade it. The authors propose that this protein with antiviral activity evolved in primates and consider that resistance or sensitivity to it should be taken into account when assessing the zoonotic potential of avian influenza viruses.

A study concludes that climate change will lead to less precipitation in the form of snow and more extreme rainfall events, especially at high altitudes in the northern hemisphere, increasing the risk of floods, landslides and infrastructure damage. According to the authors, this is the first time this risk of extreme precipitation in liquid and solid form has been studied separately. Their calculations indicate that for each degree of temperature increase, the risk of extreme rainfall in high-altitude regions will increase by 15 %. The authors publish their results in the journal Nature.

An international team, involving researchers from Hospital Clínic-IDIBAPS and the Multiple Sclerosis Centre of Catalonia (Cemcat), has identified for the first time a genetic variant related to the progression of multiple sclerosis. It is located near two genes that had not previously been linked to multiple sclerosis. According to Stephen Sawcer, co-lead author of the study, "understanding how the variant exerts its effects on the severity of multiple sclerosis will pave the way for a new generation of treatments that can prevent disease progression". The results are published in the journal Nature.