Tag Archives: Qualities

New Research Explores Mysterious Qualities of Liquid Brine Found on Mars

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Mars is at the extreme of salt water stability. And only the combination of the most favorable environmental conditions and the salt with the lowest eutectic temperature could stabilize brine, at least temporarily, on the surface of Mars, one researcher says. new research Published in Proceedings of the National Academy of Sciences.

This image of an impact crater in the Sirenum Fossai region of Mars was taken by NASA's Mars Reconnaissance rover on March 30, 2015. The crater is approximately 3,300 feet (1 km) wide and appears to be relatively recent due to its sharp edges and wells. -Stored emissions. The steep inner slopes are carved by canyons and contain slope lines that may recur on the equator-facing slopes. Image credit: NASA / JPL / University of Arizona / Alfred McEwen.

Liquid water is an important prerequisite for a habitable planet. However, the combination of Mars' low temperatures, atmospheric pressure, and water vapor pressure means that any liquid water found on Mars would likely freeze, boil, or evaporate quickly, making it unlikely that Mars exists. .

However, paleontologists continue to insist that liquid water exists on Mars.

Of particular interest is the discovery of seasonal black stripes called repeat slope lines.

These features appear in some places on Mars when temperatures rise above -23 degrees Celsius (-10 degrees Fahrenheit) and disappear when it gets colder.

They are often described as possibly being associated with liquid water.

The new study puts a damper on the idea that liquid water is likely to be found soon in Mars' recurring slopes, permafrost, or salt water.

“If we look closely at RSL, its behavior is consistent with a sand or dust flow, and water is not required for RSL formation,” said lead author Dr. Vincent Chevrier, a researcher at the University of Arkansas. said.

Other researchers believe that brine, a highly salty solution like Earth's oceans, may hold the key to finding liquid water on Mars.

Salt water can freeze at much lower temperatures, and Mars is rich in salt.

Among these salts, perchlorate appears to be the most promising because of its extremely low eutectic temperature (the temperature at which the melting point of the mixture is lower than that of the single components).

For example, calcium perchlorate brine freezes at -75 degrees Celsius (-14 degrees Fahrenheit), but the average surface temperature near the equator of Mars is -50 degrees Celsius (-58 degrees Fahrenheit), so theoretically This suggests that there may be zones where calcium coagulates. Perchlorate water can remain liquid, especially underground.

Dr. Chevrier and his colleague, Dr. Rachel Srank of the Lunar and Planetary Institute, then considered all the arguments for and against brine that could form a stable liquid.

“A variety of limiting factors, including the relatively small amount of most promising salts, water vapor pressure, and ice position, strongly limit the amount of brine present at the surface and in the shallow subsurface,” the researchers said. Ta.

“And even if saline waters formed, they would still remain uninhabitable by terrestrial standards.”

“Despite these drawbacks and limitations, there is always a possibility that Martian life adapted to these salt waters and some terrestrial life could survive in them. This is a planetary protection consideration because there is a possibility that

“Therefore, detecting brine in situ remains a key objective for Mars exploration.”

The next hurdles ahead, the authors say, are improving the equipment needed to detect small amounts of brine, better identifying the best places to look for brine, and conducting more experiments under Martian conditions. It is suggested that this is to enable room measurements to be carried out.

“Despite our best efforts to prove otherwise, Mars remains a cold, dry, and completely uninhabitable desert,” Chevrier said.

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Vincent F. Chevrier and Rachel A. Slank. 2024. The elusive nature of liquid brine on Mars. PNAS 121 (52): e2321067121;doi: 10.1073/pnas.2321067121

Source: www.sci.news

Ill chimpanzees search for different plants with medicinal qualities

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A chimpanzee eating sandpaper nuts in Budongo Forest, Uganda.Fig genus

Elodie Freyman (CC-BY)

Some plants that chimpanzees eat when they are sick or injured have been found to have medicinal properties, providing some of the strongest evidence yet that our close relatives self-medicate.

Although there have been reports for decades of chimpanzees using plants to self-medicate, it's difficult to pinpoint when wild animals get sick and what effect their diet may have.

Elodie Freyman Oxford University researchers tracked wild chimpanzees in Uganda's Budongo Forest, recording when they became ill and what they ate. By analysing feces for signs of intestinal parasites and examining urine samples for elevated levels of immune cells, the researchers identified chimpanzees with obvious wounds or intestinal infections.

An analysis of 53 plant extracts ingested by sick or injured chimpanzees found that 88 percent were effective against bacteria pathogenic to humans, including antibiotic-resistant strains like MRSA, and extracts from all species sampled had anti-inflammatory properties.

This systematic approach has allowed the researchers to identify and characterize more species used by chimpanzees than ever before. Kirsty Graham “It's a very impressive project,” said Robert Cole, a researcher at the University of St. Andrews in the UK who was not involved in the work.

Sick chimpanzees would leave the safety of their group to eat certain plants, often choosing plants that were rarely eaten in that area. The rarity of these events makes self-medicating behavior very difficult to observe, but at the same time, it is one of the strongest pieces of evidence that it is a targeted response to illness.

Chimps are typically hesitant to try unfamiliar foods that might be dangerous, Freiman says, so choosing to eat an unusual plant means they have a special reason to do so: “If they're sick, they're not going to stuff their mouths with things that might make them sicker,” she says.

But this doesn't capture everything that's going on, Graham says, because chimpanzee diets are still very diverse. Over generations, a chimpanzee community may be able to overcome this reluctance to new foods if chimpanzees learn from other animals which plants to eat. Simultaneous direct comparisons of the diets of sick and healthy chimpanzees might reveal whether these are active choices, Graham suggests.

Team Members Fabian Schultz Researchers at the Brandenburg University of Applied Sciences in Germany hope that by identifying active compounds in plant extracts, they might uncover promising drug candidates for humans. “What if we could save human lives by following the example of our animal companions?” he says.

In a report released earlier this year, an orangutan, another great ape, was spotted applying plant leaves directly to a wound in an apparent act of self-medication.

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Source: www.newscientist.com

Researchers find natural method to enhance the meat-like qualities of plant-based meat

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Recent research has revealed that fermenting alliums such as onions with fungi can naturally mimic the flavor of meat, offering a promising solution for enhancing plant-based meat substitutes without the use of synthetic additives. measures are provided.

Plant-based alternatives like tempeh and bean burgers offer protein-rich options for those looking to cut back on meat. However, it is difficult to imitate the taste and aroma of meat, and many companies use artificial additives for this purpose. Recent research in ACS Journal of Agricultural and Food Chemistry revealed a promising solution. Onions, chives, and leeks can produce natural compounds that resemble meat flavors when fermented with typical fungi.

An innovative approach to natural meat flavoring

When food manufacturers want their plant-based meat alternatives to taste more like meat, they often add precursor ingredients found in the meat that transform into flavorants during cooking. Alternatively, flavors are first prepared by heating flavor precursors or other chemical manipulations and then added to the product.

Because these flavors are created through a synthetic process, many countries do not allow food manufacturers to label them as “natural.” To utilize plant-based “natural” meat flavors, flavor chemicals must be physically extracted from plants or produced biochemically using enzymes, bacteria, and fungi. So YanYan Zhang and colleagues wanted to see if they could produce the same chemicals from vegetables and spices using fungi, which are known for producing meat-like tastes and smells from synthetic ingredients.

Allium releases the aroma of meat

The team fermented different fungi seed After experimenting with different foods, I found that meaty aromas only come from foods in the allium family, such as onions and leeks. The sample with the strongest aroma was one in which the fungus Polyporus umbellatus was used to ferment onions for 18 hours, producing a fatty and meaty aroma similar to liverwurst.

The researchers used gas chromatography-mass spectrometry to analyze onion ferments to identify flavor and odor chemicals, many of which are known to be responsible for various flavors in meat. discovered a chemical substance. One of the chemicals they identified was bis(2-methyl-3-furyl) disulfide, a strong odorant found in meat and savory foods.

The researchers say the high sulfur content of alliums contributes to their ability to produce meat-flavoring compounds, and these compounds often also contain sulfur. These onion ferments could one day be used as a natural flavoring agent in a variety of plant-based meat substitutes, the researchers say.

Reference: “Sensoproteomic discovery of taste-modulating peptides and taste re-engineering of soy sauce” Manon Jünger, Verena Karolin Mittermeier-Kleßinger, Anastasia Farrenkopf, Andreas Dunkel, Timo Stark, Sonja Fröhlich, Veronika Somoza, Corinna Dawid, and Thomas Hofmann, 2022 May 20th Journal of Agricultural and Food Chemistry.
DOI: 10.1021/acs.jafc.2c01688

The authors acknowledge funding from Adalbert-Raps-Stiftung.

Source: scitechdaily.com