Fertilizers and manure applied to cropland increase yields are often lost via surface erosion, soil leaching, runoff, increasing nutrient loads in sub-surface waters, degrading water quality, worsening the ‘dead zone’ Gulf of Mexico. We leverage spatial temporal variation agricultural practices precipitation events examine how these factors affect stream total phosphorus (TP) concentrations Sug...

Cholinesterase Activity in Female Greenhouse Workers—Influence of Work Practices and Use of Oral Contraceptives: Jesper B NIELSEN, et al. Environmental Medicine, University of Southern Denmark—Objectives—Associations between serum butyryl cholinesterase activity in female greenhouse workers and information from a questionnaire on work, use of personal protective equipment, and lifestyle were ev...

Dissolved organic matter (DOM) is an important factor in aquatic ecosystems, which is involved in a large variety of biogeochemical and ecological processes, and recent literature suggests that it could be strongly affected by agriculture in different climates. Based on novel monitoring techniques, we investigated the interaction of climate and agriculture effects on DOM quantity and quality. T...

Seasonal and spatial variability in environmental factors may affect dissolved organic matter composition and nutrient transformation and retention in streams. The objective of this research was to quantify and describe seasonality, quantity, and quality of nutrient processing and export of ammonium (NH4), soluble reactive phosphate (SRP), and dissolved organic carbon (DOC) into Lake Superior t...

Clear Lake is on Iowa's list of impaired water bodies because of high P concentration. This study assessed soil-test phosphorus (STP), management practices, and P loads from its agricultural watershed. Management practice histories and STP for eight basins were surveyed in 1999. Soil samples (15-cm depth) were analyzed for STP with agronomic [Bray P1 (BP), Olsen (OP), Mehlich 3 (M3P) and enviro...

Accurately determining sediment loads is necessary for managing river environments but difficult because multiple processes can lead to large discharge-independent changes in transport. Thus, estimations of load using discharge–sediment rating curves fit sparse or historical sediment-transport measurements be inaccurate, necessitating alternative approaches reduce uncertainty. Continuous uncert...

High-frequency sampling of two major stream inflows to a large eutrophic lake (Lake Rotorua, New Zealand) was conducted to measure inputs of total suspended sediment (TSS), and fractions of nitrogen and phosphorus (P). A total of 17 rain events were sampled, including three during which both streams were simultaneously monitored to quantify how concentration-discharge (Q) relationships varied b...

OBJECTIVE When matching target force during pain, single motor unit (SMU) discharge is modified in a manner thought to redistribute load in painful tissue. This adaptation might not be appropriate when maintaining joint posture against an external load. We compared changes in SMU discharge rate of knee extensor muscles in a force-control and a position-control task during pain. METHODS Thirte...

A mandatory best management practices (BMP) program was implemented in the Everglades Agricultural Area (EAA) farms basin-wide in 1995 as required by the Everglades Forever Act to reduce P loads in drainage water reaching the Everglades ecosystem. All farms in the EAA basin implement similar BMPs, and basin wide P load reductions have exceeded the 25% reduction required by law; however, differe...

Because of high costs or complex logistics, scientific populations cannot be measured entirely and must be sampled. Accepted scientific practice holds that sample selection be based on statistical principles to assure objectivity when estimating totals and variances. Probability sampling--obtaining samples with known probabilities--is the only method that assures these results. However, probabi...