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...

Small hydropower plants do more harm than good: Conflicting goals in European environmental and energy policy

Hydropower is renewable, but mostly not environmentally friendly. A study led by the Leibniz Institute of Freshwater Ecology and Inland Fisheries (IGB) shows for Romania how the expansion of hydropower runs counter to the goals of EU environmental policy. Hydropower conflicts with the requirements of the Flora-Fauna-Habitat Directive (Natura 2000) and the European Water Framework Directive (WFD):...

Newly discovered African 'climate seesaw' drove human evolution

While it is widely accepted that climate change drove the evolution of our species in Africa, the exact character of that climate change and its impacts are not well understood. Glacial-interglacial cycles strongly impact patterns of climate change in many parts of the world, and were also assumed to regulate environmental changes in Africa during the critical period of human evolution over the...

Extreme greenhouse effect heated up the young Earth

Very high atmospheric CO2 levels can explain the high temperatures on the still young Earth three to four billion years ago. At the time, our Sun shone with only 70 to 80 percent of its present intensity. Nevertheless, the climate on the young Earth was apparently quite warm because there was hardly any glacial ice. This phenomenon is known as the 'paradox of the young weak Sun." Without an...

Overconfidence in news judgement

A new study published in Proceedings of the National Academy of Sciences finds that individuals who falsely believe they are able to identify false news are more likely to fall victim to it. In the article published today, Ben Lyons, assistant professor of communication at the University of Utah, and his colleagues examine the concern about the public's susceptibility to false news due to their...

New 'Swiss Army knife' cleans up water pollution

Phosphate pollution in rivers, lakes and other waterways has reached dangerous levels, causing algae blooms that starve fish and aquatic plants of oxygen. Meanwhile, farmers worldwide are coming to terms with a dwindling reserve of phosphate fertilizers that feed half the world's food supply.

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

Art Garfunkel once described his legendary musical chemistry with Paul Simon, "We meet somewhere in the air through the vocal cords ... ." But a new study of duetting songbirds from Ecuador, the plain-tail wren (Pheugopedius euophrys), has offered another tune explaining the mysterious connection between successful performing duos.

Using fossil plant molecules to track down the Green Sahara

Researchers have developed a new concept to explain the phenomenon known as Green Sahara. They demonstrate that a permanent vegetation cover in the Sahara was only possible under two overlapping rainy seasons. Dr. Enno Schefuß of MARUM—Center for Marine Environmental Sciences of the University of Bremen, Dr. Rachid Cheddadi of the University of Montpellier, and their colleagues have now...

Researchers report reference genome for maize B chromosome

Three groups recently reported a reference sequence for the supernumerary B chromosome in maize in a study published online in PNAS. Dr. James Birchler's group from University of Missouri, Dr. Jan Barto's group from Institute of Experimental Botany of the Czech Academy of Sciences and Dr. Han Fangpu's group from the Institute of Genetics and Developmental Biology of the Chinese Academy of Sciences...

Study among college students shows that 39.2% send sexual content via mobile phone or social networks

As many as 39.2% of young university students surveyed in a study carried out by Enrique García-Tort and Laura Monsalve Lorente, from the Department of Teaching and School Organisation at the University of Valencia, have practiced sexting: Sending sexual content via mobile phone or social media. The research also shows a correlation between moral assessment, risk perception and frequency, meaning...

Right-wing rhetoric and the trivialization of pandemic casualties

Right-wing voices set out powerful but misleading arguments to justify inaction by the Trump administration during the COVID-19 pandemic, according to a new study of the rhetoric used by high-level government officials and influential commentators in the US during the first half of 2020.