Abstract Crude oil is a complex mixture that includes polycyclic aromatic hydrocarbons (PAHs) as one of its major components. The toxicity some chemically substituted PAHs found in oil, such the methylated species, are relatively understudied. A combination chemical fractionation and analysis coupled with bioassay was used to identify subset activated aryl hydrocarbon receptor (AHR). Silica gel...

El’gygytgyn Crater Lake, NE Siberia was investigated for sedimentological proxies for regional climate change with a focus on the past 65 ka. Sedimentological parameters assessed relative to magnetic susceptibility include stratigraphy, grain size, clay mineralogy and crystallinity. Earlier work suggests that intervals of high susceptibility in these sediments are coincident with warmer (interg...

Ice accretion on exposed surfaces of aero-engine components has been widely recognized as a significant hazard to aviation safety in cold weathers. Icing process due the impingement supercooled water droplets suspended cloud onto inlet aeroengines have studied extensively for decades. Since ice particles were believed simply bounce off from components, crystals clouds initially considered not p...

The extent to which birds select specific microsites during their diurnal activity and the thermal consequences of microsite selection during the day has received scant attention (DeWoskin 1980; Walsberg 1985, 1993: Weathers and Sullivan 1989). Most research has focused on microsite selection and the physiological consequences of occupancy of specific sites such as nocturnal roosts or nest site...

In the mountainous Rio Icacos watershed in northeastern Puerto Rico, quartz diorite bedrock weathers spheroidally, producing a 0.2–2 m thick zone of partially weathered rock layers ( 2.5 cm thickness each) called rindlets, which form concentric layers around corestones. Spheroidal fracturing has been modeled to occur when a weathering reaction with a positive DV of reaction builds up elastic st...

1. The duration of maximal activity and the intensity of anaerobic metabolismwere measured in lowland Sceloporus occidentalis at low (200 ft) and high (10,150 ft) elevations and compared to those of resident S. occidentalis and S. graciosus at high altitude. 2. The duration of maximal activity is independent of altitude: all groups of S. occidentalis had the same stamina, regardless of the alti...

SSSAJ: Volume 72: Number 6 • November–December 2008 Soil Sci. Soc. Am. J. 72:1786-1794 doi:10.2136/sssaj2007.0344 Received 19 Sept. 2007. Corresponding author ([email protected]). © Soil Science Society of America 677 S. Segoe Rd. Madison WI 53711 USA All rights reserved. No part of this periodical may be reproduced or transmitted in any form or by any means, electronic or mechanical, including ph...

Leaf area index (LAI) is a key parameter to characterize vegetation dynamics and ecosystem structure that determines the ecosystem functions and services such as clean water supply and carbon sequestration in a watershed. However, linking LAI dynamics and environmental controls (i.e., coupling biosphere, atmosphere, and anthroposphere) remains challenging and such type of studies have rarely be...

North, discusses and illustrates stress and frustration among rural adolescents. The article is based on tapes of classroom discussion and written work produced while the author was a teacher. We live in the fourth most densely populated country in the world. For the most part we are town dwellers, thinking urban thoughts, experiencing urban feelings, constructing urban plans for the future. We...