Terrestrial soil is a large reservoir of atmospherically deposited mercury (Hg). However, few studies have evaluated the accumulation of Hg in terrestrial ecosystems in the northeastern United States, a region which is sensitive to atmospheric Hg deposition. We characterized Hg and organic matter in soil profiles from 139 sampling sites for five subregions across the northeastern United States ...

[1] Little is known about the role of vegetated hillslope sediment transport in the soil C cycle and soil-atmosphere C exchange. We combined a hillslope sediment transport model with empirical soil C measurements to quantify the erosion and temporal storage of soil organic carbon (SOC) within two grasslands in central California. The sites have contrasting erosional mechanisms: biological pertu...

in recent years, machine vision and optical sensors, which can be used in an autonomous weed killing equipment, are being used extensively to detect weeds from crops. in this study, seven types of weeds that grow in most of the sugar beet fields in iran, especially in fars province, were considered in real outdoor conditions. several color feature extraction algorithms have also been investigat...

The impact of increasing anthropogenic atmospheric nitrogen deposition on marine biogeochemistry is uncertain. We performed simulations to quantify its effect on nitrogen cycling and marine productivity in a global 3-D ocean biogeochemistry model. Nitrogen fixation provides an efficient feedback by decreasing immediately to deposition, whereas water column denitrification increases more gradual...

The relative role of protein synthesis and degradation in determining postprandial net protein deposition in human muscle is not known. To this aim, we studied forearm leucine and phenylalanine turnover by combining the arteriovenous catheterization with tracer infusions, before and following a 4 h administration of a mixed meal in normal volunteers. Forearm amino acid kinetics were assessed in...

The major N-containing polymer compounds in the body include protein, RNA, and DNA. The endogenous gastrointestinal secretions as well as the portal-drained visceral and peripheral immune responses are basic physiological functions. Elevated endogenous secretions and immune activities, as affected by developmental stages, diets, and management factors, decrease the availability of dietary nutri...

the aim of this study was to evaluate the physical characteristics, chemical composition and protein fractions of sugar beet pulp produced in iran and comparing them with the tabular values of cornell net carbohydrate and protein system. a total of 39 samples of 13 different sugar factories were sampled from iran-wide. particle size distributions of samples were determined using the penn state ...

abstract the purpose of this study is investigating factors affect on probability of willingness to pay sugar beet farmers for taking of agricultural extension services. logit model was used for cross sectional data in 2009 between 150 sugar beet farmers that were selected by random sampling in the city of mashhad. in addition, tobit model was used to analyse factors affecting on willingness to...