urea tagged posts

Scientists uncover what delayed Earth’s oxygen boom for a billion years

What Delayed Earth’s Oxygen for a Billion Years
High levels of nickel and urea once throttled early cyanobacteria, keeping Earth’s air oxygen-free. Their gradual decline unleashed an oxygen boom that transformed the planet and made complex life possible. Credit: Shutterstock

Billions of years ago, cyanobacteria began releasing oxygen through photosynthesis, but the atmosphere stayed oxygen-poor for ages. Researchers uncovered that trace compounds like nickel and urea may have delayed Earth’s oxygenation for millions of years. Experiments mimicking early Earth revealed how their concentrations controlled cyanobacterial growth, dictating when oxygen began to accumulate. As nickel declined and urea stabilized, photosynthetic life thrived, sparking the Great Oxidation Event...

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Simulated Mission to Mars: Salty diet makes you Hungry, Not Thirsty

Renal urea accumulation, plasma Na+ and urea concentration, and plasma osmolality in response to experimental salt loading

Renal urea accumulation, plasma Na+ and urea concentration, and plasma osmolality in response to experimental salt loading

New studies show that salty food diminishes thirst while increasing hunger, due to a higher need for energy. We’ve all heard it: eating salty foods makes you thirstier. But what sounds like good nutritional advice turns out to be an old-wives’ tale. In a study carried out during a simulated mission to Mars, an international group of scientists has found exactly the opposite to be true. “Cosmonauts” who ate more salt retained more water, weren’t as thirsty, and needed more energy.

For some reason, no one had ever carried out a long-term study to determine the relationship between the amount of salt in a person’s diet and his drinking habits...

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