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Background: Activity monitors (AM) are small, electronic devices used to quantify the amount and intensity of physical activity (PA). Unfortunately, it has been demonstrated that data loss that occurs when AMs are not worn by subjects (removals during sleeping and waking hours) tend to result in biased estimates of PA and total energy expenditure (TEE). No study has reported the degree of data loss in a large study of adults, and/or the degree to which the estimates of PA and TEE are affected. Also, no study in adults has proposed a methodology to minimize the effects of AM removals. Methods: Adherence estimates were generated from a pool of 524 women and men that wore AMs for 13 - 15 consecutive days. To simulate the effect of data loss due to AM removal, a reference dataset was first compiled from a subset consisting of 35 highly adherent subjects (24 HR; minimum of 20 hrs/day for seven consecutive days). AM removals were then simulated during sleep and between one and ten waking hours using this 24 HR dataset. Differences in the mean values for PA and TEE between the 24 HR reference dataset and the different simulations were compared using paired t-tests and/or coefficients of variation. Results: The estimated average adherence of the pool of 524 subjects was 15.8 ± 3.4 hrs/day for approximately 11.7 ± 2.0 days. Simulated data loss due to AM removals during sleeping hours in the 24 HR database (n = 35), resulted in biased estimates of PA (p < 0.05), but not TEE. Losing as little as one hour of data from the 24 HR dataset during waking hours results in significant biases (p < 0.0001) and variability (coefficients of variation between 7 and 21%) in the estimates of PA. Inserting a constant value for sleep and imputing estimates for missing data during waking hours significantly improved the estimates of PA. Conclusion: Although estimated adherence was good, measurements of PA can be improved by relatively simple imputation of missing AM data. [ABSTRACT FROM AUTHOR]

Urea is the most widely used N fertilizer due to its high N concentration (46%), cost effectiveness and ease of handling. However, urea is susceptible to loss as N 2 O, a greenhouse gas and catalyst of stratospheric ozone decline. Polymer-coated fertilizers may be effective in reducing such losses but the appropriate coating thickness for effective field performance is unknown. We prepared urea granules with polyurethane coating (PCU) based on castor oil at 2%–8% by weight. We tested the fertilizer value of these materials for maize (Zea mays L.) and measured field loss of N 2 O. Maize grain yield and N uptake were similar in treatments fertilized with urea (uncoated) and each of the coated materials. Cumulative N 2 O–N per unit of grain yield, however, was reduced by 80% with PCU8% compared with uncoated urea. Results indicate that polyurethane-coated urea performs similarly to uncoated urea for maize production while reducing soil N 2 O emissions up to 60–80%, with an efficiency factor twice as high as that suggested by the Intergovernmental Panel on Climate Change (IPCC) for N fertilizers. Our results indicate that urea with a polyurethane coating of 8% (PCU8%) had the best combined agronomic and environmental performance in a field study. Image 1 • Polyurethane-coated urea reduced soil N 2 O emissions up to 60–80%. • Control of urea release achieved using polyurethane coating derived from castor oil. • Rate of urea release was controlled by the thickness of the coating. [ABSTRACT FROM AUTHOR]

In 1998, twenty-five 4-Poster deer treatment bait stations were deployed on Gibson Island (GI), Maryland, as part of the U.S. Department of Agriculture (USDA) Northeast Area-Wide Tick Control Project. Treatments concluded in June 2002, having achieved 80% and 99.5% control of blacklegged ticks, Ixodes scapularis, and lone star ticks, Amblyomma americanum, respectively. No area-wide tick control was attempted again on the island until 2003, when 15 Dandux-manufactured 4-Posters were purchased by the GI Corporation and operated until the present. Annual flagging at sites on the island and a similar untreated area on the nearby mainland in May and June from 1998 to 2007 has demonstrated that populations of host-seeking nymphs of both tick species have remained at consistently low levels on the island during GI Corporation administration of the 4-Posters, in spite of 40% fewer 4-Posters and increased deer density during 2003-2007.

From 1998-2002 twenty-five deer self-treatment devices (4-Posters), using 2% amitraz, were operated at three locations in Maryland to determine their effectiveness in controlling blacklegged ticks, Ixodes scapularis Say, and lone star ticks, Amblyomma americanum (L.). Each treatment site was approximately 518 ha and paired with a similar site lacking 4-Posters. Locations varied in deer density, tick abundance, and land use. Flagging for host-seeking ticks showed declines in tick populations at all treatment sites compared to control sites by the third year. By 2002, control of I. scapularis nymphs attributable to the 4-Poster intervention at the three sites was 69.0%, 75.8%, and 80%. Control of A. americanum nymphs at the two sites where they occurred was 99.5% and 95.3%. In 2003, the first posttreatment year, control of I. scapularis remained around 2001-2002 levels, but by 2004, an upward trend in nymphal numbers was detectable. Populations of A. americanum showed no increase posttreatment. These results demonstrate that control of these tick species is locally possible with 4-Poster intervention.