post

New non-photosynthesising orchid discovered in Japan

A new species of orchid has been discovered by Japanese scientists on the subtropical islands of Amami-Oshima and Tokunoshima. The new species, called Gastrodia amamiana, resembles the Gastrodia uraiensis but boasts subtle differences in the structure of the petals and the stem.

It is a plant that “self-fertilizes” forming the bud without opening the flowers, one of those non-photosynthesising plants that grow on the soil of forests in environments that are not usually visited by flying pollinators such as butterflies and bees. According to the researchers, this plant has evolved so that it no longer opens its flowers because the same opening action exhausts too many resources. Schemes similar at the evolutionary level can be noted among other things also in other mycoheterotrophic plants, that is, plants that no longer do photosynthesis and that have evolved to be parasites feeding on mushrooms.

Among other things, the same island of Amami-Oshima has seen this year the discovery of two new species of mycoherotrophic plants, the Lecanorchis moritae amamiana and the Didymoplexis siamensis. However, the deforestation in progress in these areas is making the trees thinner and the drier soil could have a negative impact on the fungi and therefore also on this type of plant.

post

High levels of estrogen in the uterus linked to autism according to new study

Exposure to higher levels of fetal estrogen in the uterus would be linked to higher chances of developing autism according to a study conducted by a team of researchers from the University of Cambridge.

The study began in 2015 when scientists at the English University, in collaboration with the Swedish Statens Serum, began to analyze the levels of four prenatal steroid hormones present in amniotic fluid in the uterus. Long-term analysis has allowed us to discover the connection between the high levels of these hormones and the autism developed by children. The researchers found that the highest levels in male fetuses were present in which children then developed autism once they were born.

In particular, the connection was stronger against the androgenic hormones. The latter, which also plays a role in the number of connections between brain cells, are produced mostly in male fetuses rather than in female fetuses and this would explain, according to the press release published on the University website, also because autism is more contracted by male children.

Researchers noted that all four estrogens existed at higher levels, on average, in fetuses that then developed autism than fetuses they did not develop.

Simon Baron-Cohen, director of the Autism Research Center in Cambridge, states in the press release: “This new discovery supports the idea that an increase in prenatal steroid hormones is one of the potential causes of the condition.”

According to the scientist, these hormones probably influence the development of the brain of the fetus by acting on genetics.

post

Small exoplanet mass 254 light-years away measured with unprecedented precision

A new extrasolar planet has been analyzed thanks to the NASA Kepler space telescope that does not want to know how to retire. This planet turns out to be the one for which the mass has been identified in a more precise way than any other exoplanet so small, at least until today. The same researcher who carried out the measurement, Aaron Hamann, first author of the study, declares that it was a “completely unexpected” thing.

There is talk of a “record precision” allowed precisely by the ways in which this planet, along with another, revolves around its star. The first time Kepler scoured the K2-146 star, located 258 light-years away from us, the scientists noticed an irregular darkening pattern. We talk about the darkening caused by the passage of the planet in front of the star from our point of view, which allows us to implement the so-called “transit method,” one of the most used to discover planets beyond the solar system.

Comparing the data of the first passage with those of the second and third, always identified by Kepler years later, the scientists understood that this irregularity was caused by a second smaller planet that pulled the first planet by gravitational force. Every time they approached, a sort of “mini slingshot effect” was created, as reported by Hamann himself.

If this strong gravitational bond between the two planets is added that the two planets orbit around their star in a few days (3.99 days for the largest and 2.66 days for the smallest), there is also a strong effect on the orbit so much that sometimes they can have significantly shorter or longer years: “It would be as if your birthday sometimes arrived almost a month before or later than you would normally expect,” reports the researcher to cite a case in point.

Kepler also observed the planets in key points during the transits: they were basically caught at the right time at the moment of transit, always from our point of view, in front of their star. In this way, they measured the mass of the smallest planet with an accuracy of 3%.