Tag Archives: downstream

Unchecked Antibiotic Use in Animals May Affect Global Human Health

The increasing production and use of antibiotics, about half of which is used in animal production, is mirrored by the growing number of antibiotic resistance genes, or ARGs, effectively reducing antibiotics’ ability to fend off diseases – in animals and humans.

A study in the current issue of the Proceedings of the National Academy of Sciences shows that China – the world’s largest producer and consumer of antibiotics – and many other countries don’t monitor the powerful medicine’s usage or impact on the environment. (more…)

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Landslides Linked to Plate Tectonics Create the Steepest Mountain Terrain

Some of the steepest mountain slopes in the world got that way because of the interplay between terrain uplift associated with plate tectonics and powerful streams cutting into hillsides, leading to erosion in the form of large landslides, new research shows.

The work, presented online May 27 in Nature Geoscience, shows that once the angle of a slope exceeds 30 degrees – whether from uplift, a rushing stream carving away the bottom of the slope or a combination of the two – landslide erosion increases significantly until the hillside stabilizes.

“I think the formation of these landscapes could apply to any steep mountain terrain in the world,” said lead author Isaac Larsen, a University of Washington doctoral student in Earth and space sciences. (more…)

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A River Ran Through It

About the image: A now dry Colorado River delta branches into the Baja/Sonoran Desert near the Sea of Cortez. Image credit: Pete McBride

Rivers and streams supply the lifeblood to ecosystems across the globe, providing water for drinking and irrigation for humans as well as a wide array of life forms from single-celled organisms up to the fish humans eat.

But humans and nature itself are making it tough on rivers to continue in their central role to support fish species, according to new research by a team of scientists including John Sabo, a biologist at Arizona State University.

Globally, rivers and streams are being drained due to human use and climate change. These and other human impacts alter the natural variability of river flows.

Some affected rivers have dried and no longer run, while others have seen increases in the variability of flows due to storm floods. (more…)

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