There is significant archaeological evidence marking the collapse of the Shijiahe culture in the middle reaches of the Yangtze River in China during the late Neolithic Period. However, the causes for this cultural collapse remain unclear. Our sedimentary records from a 3.3 m long profile and 76 phytolith and charcoal samples from the Tanjialing archaeological sites provide records of interactio...

a Department of Informatics Engineering, Faculty of Engineering, University of Porto, Rua Dr. Roberto Frias, 4200-465 Porto, Portugal b Department of Informatics Engineering, Faculty of Sciences and Technology, Rua Sílvio Lima, Universidade de Coimbra— Pólo II, 3030-790 Coimbra, Portugal c Centre for Informatics and Systems, Universidade de Coimbra, DEI, Pólo II, Pinhal de Marrocos, 3030-290 Co...

The ecology in the Gulf of California has undergone dramatic changes over the past century, including the emergence of Humboldt squid (Dosidicus gigas) as a dominant predator. In the face of these changes, we compare the ubiquitous and ecologically important concentrations of mid-water organisms that comprise acoustic scattering layers to published results, describing their occurrence in detail...

INTRODUCTION The resin infiltration technique, a minimally invasive method, involves the saturation, strengthening, and stabilization of demineralized enamel by a mixture of polymer resins without the need to use rotary tools or the risk of losing healthy tooth structures. AIM OF THE STUDY To design and synthesize an experimental infiltrant with potential bacteriostatic properties.To compare ...

Binary cycle power plants have been used successfully for electricity generation utilizing co-produced fluids from active onshore oil wells. Adapting this process for use on abandoned wells by circulating the binary working fluid down the wellbore has been previously proposed and a selection of fluids evaluated. This work proposes and evaluates an approach using water as the wellbore fluid in c...

High-mountain lakes are unique ecosystems with very few examples at tropical latitudes for experimentation. A two-year, high-frequency meteorological and water-column dataset from the crater of Nevado de Toluca volcano, in Mexico, an altitude about 4200 m above sea level, allowed study temporal changes thermal structure, water balance Lakes El Sol La Luna, separated by 500 a lava dome. Annual f...

Species richness and diversity of Carabidae (Coleoptera), as well as rates of endemicity, are studied along altitudinal transects in the páramo of Ecuadorian Andes, from 3500 to 5000 m. Whereas a global tendency to reduction of species richness is evident from 4200 m upwards, two zones of high diversity and high proportion of endemic species occur at 3800–4000 m and at 4200–4400 m. Species turn...

1269 Reproducibility of individual response to exposure to high altitude The response of people who live at sea level to the low oxygen concentrations at high altitude varies widely. Some people are relatively unaffected while others suffer severe acute mountain sickness.' Anecdotal reports and experiments in decompression chambers have indicated that responses to high altitude are reproducible...