6,284 articles mezi dny 1.5.2021 a 31.5.2021

Iceland's glaciers lose 750 km2 in 20 years

Iceland's glaciers have lost around 750 square kilometers (290 square miles), or seven percent of their surface, since the turn of the millennium due to global warming, a study published on Monday showed.

Unravelling the mysteries of seasonal reproduction in lynx: New insights into mechanisms of corpus luteum in cats

Most of the existing 39 cat species are threatened. Successful reproduction under breeding conditions is hindered by a lack of knowledge and appropriate techniques. But now scientists from the German Leibniz Institute for Zoo and Wildlife Research (Leibniz-IZW) have succeeded in testing the influence of selected hormones on cell cultures of domestic cats and translated the methods to wild cat...

Researchers discover that a mechanical cue is at the origin of cell death decision

In many species including humans, the cells responsible for reproduction, the germ cells, are often highly interconnected and share their cytoplasm. In the hermaphrodite nematode Caenorhabditis elegans, up to 500 germ cells are connected to each other in the gonad, the tissue that produces eggs and sperm. These cells are arranged around a central cytoplasmic "corridor" and exchange cytoplasmic...

Extreme CO2 greenhouse effect heated up the young Earth

Although sun radiation was relatively low, the temperature on the young Earth was warm. An international team of geoscientists has found important clues that high levels of carbon dioxide in the atmosphere were responsible for these high temperatures. It only got cooler with the beginning of plate tectonics, as the CO2 was gradually captured and stored on the emerging continents.

Duetting songbirds 'mute' the musical mind of their partner to stay in sync

Researchers say that the auditory feedback exchanged between wrens during their opera-like duets momentarily inhibits motor circuits used for singing in the listening partner, which helps link the pair's brains and coordinate turn-taking for a seemingly telepathic performance. The study also offers fresh insight into how humans and other cooperative animals use sensory cues to act in concert with...

Newly discovered African 'climate seesaw' drove human evolution

A scientific consortium has found that ancient El Niño-like weather patterns were the primary drivers of environmental change in sub-Saharan Africa over the last 620 thousand years - the critical time-frame for the evolution of our species. The group found that these ancient weather patterns had more profound impacts in sub-Saharan Africa than glacial-interglacial cycles more commonly linked to...