Giant urban bears
Black bears that live in urban settings reproduce younger and grow faster, biologists at North Carolina State University have found. In the Journal of Mammology, they compare 36 black bears captured in Asheville, a town of 80,000 people two hours west of Charlotte, and 95 black bears captured in the forests of North Carolina. All the bears were 1 year old. Urban bears were twice as big, 50 kg versus 25 kg. The females were studied again a year later. By 2 years, half of the urban females had given birth, compared to none of the forest females. Researchers suggest eating in the city is easier.
What influence has the climate had in China for 1000 years?
When there was warming over decades, roof slopes became less steep in China. Researchers from the University of Nanjing analyzed the roofs of 200 buildings built for 1000 years in the Middle Empire. They noted that during the Little Ice Age, in the XVIe and XVIIe centuries (when the canals of the Netherlands were frozen on the boards of the time), the roofs were steeper. At the start of the period of their analysis (corresponding to the Medieval Climatic Optimum, an unusually warm period when the Vikings colonized Greenland), the roofs were flatter. The Chinese study was published in early September in Science Advances.
This is the number of major human migrations between Africa and Asia for 400,000 years, according to a German study. Analyzing stone tools found in different locations near the Jubbah oasis in northern Saudi Arabia, researchers at the Max Planck Institute for Chemical Ecology in Jena found that such tools were particularly plentiful in times when the climate was wetter, 400,000 years ago, 300,000 years ago, 200,000 years ago, 130,000 years ago and 55,000 years ago. There were then lakes in this region. Their work was published in early September in Nature.
Bricks of blood and urine
It is possible to make bricks from Martian soil, a protein found in human blood, and urea (urine and sweat). This is the conclusion of engineers at the University of Manchester, who have worked with simulated Martian soils. In the review Materials Today Bio at the end of August, British researchers noted that animal blood was added to the mortar of buildings before the advent of the first chemical binders, in the 18th century.e century.
Earthquakes that occurred before the arrival of the Spanish conquistadors are described in one of the few Aztec manuscripts that were not destroyed by settlers, Mexican archaeologists have found. In the Seismological Research Letters At the end of August, researchers from the National Autonomous University of Mexico identified 12 earthquakes described in the Codex Telleriano-Remensis. This Codex was created in the XVIe century in Mexico, from documents that no longer exist, with Aztec pictographic writing. Archaeologists have dated them with similar annotations, for example mentions of solar eclipses. Some of the descriptions are very precise: for example, an earthquake in 1507 in the south of the Mexican capital damaged a temple and resulted in the drowning of 1,800 soldiers in a river.