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Everest glaciers are melting at a dizzying pace according to satellite photos

The glaciers of Everest, considered the highest mountain in the world, are melting at a much faster rate than ever before: this is what an article published in Live Science suggests, citing declassified photos taken by spy satellites.

These are images taken over several decades through which it is possible to see and calculate the melting of the ice even in the long term. It is these images that show that, from 1962 to 2018, the glaciers on the sides of the mountain were “significantly” reduced. Among other things, the topic was also the subject of a study presented at the annual meeting of the American Geophysical Union.

These are more than 800,000 photos taken by the C.I.A. in the context of the Cold War, later declassified in 1995. Among the various regions of the world photographed by satellites, there is also that of the Himalayas. The researchers analyzed these photos and compared them with other (unclassified) satellite photos of the following years or images taken by airplanes and calculated the loss relative to the mass of ice from the 60s until today.

The comparison is merciless: the glaciers seem to retreat in a visible way and then expose the underlying rock, something that is well calculable from above. The first significant signs of ice reduction began in the 1960s: since 1962 the rate of glacier loss has been about 20 cm per year.

Over the last few decades, moreover, the same ice loss seems to have accelerated, an acceleration that would have started in the early 1980s. Among the various damages that could be caused by the loss of ice on Everest is that related to the freshwater supply in the surrounding region.

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Modern humans have crossed paths with at least five groups of archaic humans

A new study published in the Proceedings of the National Academy of Sciences (PNAS) gives us some details on the so-called blending events that have seen modern men join different groups of archaic humans in the course of their history following their departure from Africa.

It is thought that modern human beings crossed with at least five different archaic human groups in the course of their history that saw them move from Africa through Eurasia to Southeast Asia and beyond. Two of these archaic groups are known: the Neanderthals and the Denisovans group. The others remain unknown although DNA analysis shows the union of our ancestors with other different populations.

In particular, according to the researchers, it was the area of ​​South-East Asia that was a “hotbed of diversity.” As João Teixeira, a researcher at the University of Adelaide, specifies the first author of the study, “These archaic groups were widespread and genetically different and survive in each of us. Their story is an integral part of what we have become.”

An example is given by the fact that today’s populations show in their DNA about 2% of the DNA of the Neanderthals. This, and other genetic data, shows that mixing with Neanderthals must have taken place almost immediately after our ancestors left Africa, in a period between about 50,000 and 55,000 years ago somewhere in the Middle Orient. However, our ancestors, traveling further east, met and mixed with other different groups of humans.

Using various information regarding these migratory routes, the researchers concluded that an important mixing event must have occurred in the areas of southern Asia, in Southeast Asia, with a group that was named “Hominino Estinto 1.” Other crossings, probably of lesser incidence, must then have taken place in East Asia, in the Philippines and near the island of Flores, Indonesia, with another group that the same researchers called “Hominino Estinto 2.”

This information shows that the history of our ancestors once they left Africa seems to be much more complex than I previously deduced and that the South East Asian region played a very important role in the mixing events that led to modern men thanks also to a relative geographical isolation of these populations for hundreds of thousands of years.

Furthermore, this information also suggests that the disappearance of these archaic human populations occurred substantially coinciding with the arrival of modern humans.

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Cortisol levels in hair indicative of depression or mental illness in adolescents

According to a group of researchers from Ohio State University, one day it may be possible to diagnose depression or mental illness in adolescents by analyzing their hair.

Analyzing the concentration of cortisol, a stress hormone, in the hair as well as the same symptoms of depression in 432 adolescents aged between 11 and 17 years, the researchers have in fact found what was defined in the press release appeared on the website of the University as a “surprising connection.”

In fact, higher cortisol levels seemed to correspond to a greater probability of depression while lower levels could be linked to mental problems. Few types of research in the past have considered this hormone as a possible predictor of depression and in this sense, this research provides fairly new data in this sense.

In the scientific article, which appeared in Psychoneuroendocrinology, we describe the experiments and analyzes carried out by researchers who suggest, as specified by Jodi Ford, a nursing professor at the aforementioned university and the principal author of the study, that there may be an average level of cortisol which can be considered as “normal”: a level that is too low or too high could therefore indicate bad things.

This discovery leads to an important connection whose demonstration requires further research though, as Ford itself points out, “it is possible for some people to experience a reduction in the stress response that reduces cortisol production or changes the way in which is processed. Maybe the body isn’t using cortisol the way it should in some cases.”