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.

The price is right: Modeling economic growth in a zero-emission society

With increasing public awareness of crises associated with degraded environments and mounting pressure to act, governments worldwide have begun to examine environmentally sustainable policies. However, there are many questions about whether enacting these policies will negatively affect economic growth. Now, a model suggests that sustained GDP growth is possible even after spending to clean up...

Scientists discover a new genetic form of ALS in children

In a study of 11 medical-mystery patients, an international team of researchers has discovered a new and unique form of amyotrophic lateral sclerosis (ALS). Unlike most cases of ALS, the disease began attacking these patients during childhood, worsened more slowly than usual, and was linked to a gene, called SPTLC1, that is part of the body's fat production system.

Digital forensics experts prone to bias, study shows

Participants found more or less evidence on hard drive depending on what contextual information they hadDevices such as phones, laptops and flash drives are becoming increasingly central to police investigations, but the reliability of digital forensics experts’ evidence has been called into question.A study found that experts tended to find more or less evidence on a suspect’s computer hard...

Isolating an elusive missing link

The water oxidation reaction (WOR) is one of the most important reactions on the planet since it is the source of nearly all the atmosphere's oxygen. Understanding its intricacies can hold the key to improve the efficiency of the reaction. Unfortunately, the reaction's mechanisms are complex and the intermediates highly unstable, thus making their isolation and characterisation extremely...

How teachers can use video games to motivate students

If you ask your teens to do their homework they'll find a thousand other things to do. But put them in front of a video game, and they'll focus on it for hours. How exactly do game designers create this kind of engagement? And what would happen if we applied these principles to teaching?

California wildfires disproportionately affect elderly and poor residents, study finds

California's wildfire burn area has increased by more than 23,000 acres per year over the past two decades, and the number of people who have been adversely affected has nearly doubled. In a paper published recently in the International Journal of Environmental Research and Public Health, UCI researchers show that elderly and low-income residents have suffered a disproportionate share of the...

HIRAX: Looking deep into the universe for answers about dark matter

How is matter distributed within our universe? And what is the mysterious substance known as dark energy made of? HIRAX, a new large telescope array comprising hundreds of small radio telescopes, should provide some answers. Among those instrumental in developing the system are physicists from ETH Zurich.

Destination Moon: Is it time for us to send astronauts back?

The series For All Mankind (2019) is a fictional alternate history that imagines a world where the Soviet Union was the first power to send an astronaut to the moon. From that starting point, the two rival superpowers compete to establish their own lunar station.

Prehistoric carvings of red deer found in Scottish neolithic tomb

Amateur archaeologist exploring Dunchraigaig cairn found animal depictions by chanceDelicate prehistoric carvings of adult red deer, thought to be the oldest of their type in the UK, have been found in a tomb in one of Scotland’s most famous neolithic sites.The carvings, which depict two male red deer with full-grown antlers and several thought to be young deer, were discovered by chance in...

Tidal debris detected in a nearby galaxy group

Using the MeerKAT telescope, an international team of astronomers has identified wide-spread tidal debris in a nearby galaxy group known as NGC 7232. The newly found structure is composed of cold neutral atomic hydrogen and extends over 450,000 light years. The finding is reported in a paper published May 21 on arXiv.org.