Nature (category filter × )

Why are plants green?
  • Researchers created a photosynthesis model based on complex networks (cellphone, brains, power grids).
  • Based on this model, they found that photosynthetic organisms protect themselves from sudden increases in solar energy by absorbing only specific colors of light.
  • Absorbing only parts of the solar spectrum allows them to minimize noise in the output (=generated energy) of their solar cell system.
  • It’s simple physics, it allows these organisms to protect themselves, conserve energy, and - most excitingly - it is consistent with a lot of biological observations.
  • This is the first qualitative proof that photosynthetic beings (like plants) have colors (say, green) in order to protect themselves from absorbing too much energy.

Differentially charged nanoplastics demonstrate distinct accumulation in Arabidopsis thaliana
  • Study shows that Arabis (rockcress) can absorb and transport nanoplastics smaller than 200nm.
  • The plant absorbs differently charged nanoplastics in different ways, negatively charged ones being the most internalized.
  • This process can damage roots, and influence how plants transport water and nutrients, making the above-ground parts of the plant smaller.
  • Other plants, especially root crops like carrots and turnips, should be studied for the same process, as they are the foundation of many food chains.
  • Further studies will have to confirm if accumulation of nanoplastics will lead to worse crop yields, worse food quality, or even make common foods unsafe to eat.

Wild Hummingbirds can see colors that humans can’t
  • Seeing more colors gives hummingbirds an advantage when looking for food, mating, and avoiding predators.
  • Human eyes have three color-perceiving cones - red, green, blue, whereas hummingbirds have four cones.
  • The fourth cone multiplies the color-combinations these birds can recognize.
  • To discover this, scientists used a simple reward-based test to see if birds see a difference when spectral colors are enhanced with UV light.

New Studies Find Birds Are Eating Hundreds of Plastic Bits Daily
  • Not just land and sea animals are eating plastic, studies show that birds near river banks are eating hundreds of plastic debris pieces every day.
  • Scientists say this clearly tells us that plastic in rivers is moving up the wildlife food chain very quickly.
  • Researchers looked at the dipper, a bird that dives into rivers and eats underwater insects — they inges hundreds of bits of plastic every day, and feed it to their chicks.
  • It’s been known that insects are contaminated with plastic pollution, but this is the first documented transfer of plastic from insects shown in free-living river animals.
  • Similar study in Florida recently showed similar results - out of 63 examined birds of 8 different species, all of them had microplastics in their tiny bird guts.

The emergence of heat and humidity too severe for human tolerance
  • Heat combined with humidity is one of the biggest natural threats to humans, as there is an upper temperature limit on our body’s cooling mechanisms.
  • At 35 Celsius air temperature, we need to sweat to cool off, but when the wet-bulb temperature (adjusted for humidity) exceeds 35 Celsius, our bodies can’t cool off.
  • In known heat wave instances, it took only 28 Celsius wet-bulb temperature to result in severe mortality rates.
  • Global data shows that instances of >=35 Celsius wet-bulb temperatures have doubled since 1979, and are happening sooner that climate models have predicted.
  • All in all, the study warns us that humid heat is a bigger problem than we thought, and it’s getting worse every year.