Deforestation threatens more than half of all tree species in the Amazon, a study suggests.

Researchers, whose work was published in the journal Science Advances, studied the status of more than 15,000 Amazonian tree species, including the Brazil nut and the plants that produce cacao and açaí palm.

By comparing maps of projected deforestation with data collected in the forest, the researchers found that at least 36 percent and up to 57 percent of the Amazon’s tree species should qualify as threatened on the International Union for Conservation of Nature’s Red List, the most widely recognized authority on threats to species conservation. Their findings suggest that the number of globally threatened plant species could increase by about 22 percent, and globally threatened tree species by 36 percent.


Taste hard-wired into the brain

You probably know that we perceive five basic tastes, and that taste has something to do with the tongue and the brain. But a study shows just how weird our perception of reality is: Scientists showed that all it takes to convince a mouse that its mouth is full of sweet nectar or bitter poison is the manipulation of a few brain cells.

Learning more about this mechanism could unlock secrets of the human brain, perhaps even paving the way for new treatments for eating disorders, the researchers say.

The results published in Nature show that taste is hard-wired in the brain, and can be triggered as easily by electrical signals as it can be by actual flavor chemicals.


Fingerprint may identify gender

A simple test performed at a crime scene may help forensic scientists determine whether a fingerprint belongs to a man or a woman, a study reports.

The test is based on certain amino acids found in the fingerprints. Levels are twice as high in the sweat of women as in that of men. The report was published in the journal Analytical Chemistry.


Flower power blooms in lab

A bedside light powered by the houseplant sitting next to it? It may be possible.

Engineers in Sweden have managed to introduce electronic circuits into living plants, said a study in the journal Science Advances.

The scientists placed plant cuttings in water that contained a water-soluble polymer called PEDOT-S. After the plants absorbed the water, hardened polymer remained, distributed through the plant as a conductive “wire.” The researchers used rose cuttings in their study, as well as some living rose plants.

By combining the wires with electrolytes naturally present in the plant, the researchers were able to create a transistor that converts electrochemical signals into electrical output.

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