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Effects of composting manure on viability of Giardiacysts (GC) and Cryptosporidiumcysts (CO) were determined in a two-year study with manure from feedlot cattle bedded on barley straw or woodchips. Each year, manure was deposited in 8 m × 2.5 m × 2 m windrows (one per bedding type) on a sheltered concrete pad. On day 0, porous bags containing 100 g of feces from confirmed Giardia- and Cryptosporidium-positive cattle (9 bags per retrieval day in Year 1; 3 per day in Year 2) were implanted in the windrows. Replicate bags were placed on the concrete pads as uncomposted controls. Windrow temperature and water content were measured and compost was turned mechanically twice each week. Fecal bags were retrieved and subsampled for enumerations of total and viable cysts and cysts after 1, 2, 3, 7, 10, 17, 24 and 31 days in 1998 and after 1, 2, 3, 7, 9, 16, 23, 30, 42, 56, 70 and 98 days in 1999. Windrow temperatures (TEMP) exceeded 55°C during the fourth week of composting, and remained above 50°C for 4 wk thereafter in 1999. Bedding material did not affect overall mean temperature in either year, but TEMP was higher with straw than with woodchip from day 10 to day 17 in 1998 (P< 0.05) and on day 16 and day 42 in 1999 (P< 0.10). In 1998, moisture content decreased from 62.2 to 43.2% during composting of woodchip manure and from 67.3 to 39.3% during composting of straw manure. In 1999, moisture content decreased from 61.0 to 31.8% for woodchip and from 64.5 to 28.6% for straw compost. Percentage of viable CO declined gradually over the 31 days in 1998. The following year revealed a rapid decline in viability of GC and CO once compost temperature exceeded 55°C and viabilities of GC and CO were reduced to zero after 42 days (straw compost) and after 56 days (woodchip compost). Exposure of CO and GC to temperatures > 55°C for a period of 15 days appears to be an effective method of inactivating Giardiacysts and Cryptosporidiumcysts in feedlot manure.

Traditionally, performing myocardial contrast echocardiography with OPTISON required maximal bolus dosing. However, sustained and consistent opacification of the myocardium would be preferable for perfusion imaging. Methods: Images of 5 anesthetized dogs and 6 human volunteers were obtained with a second harmonic ultrasound system during bolus administration of OPTISON and 2 infusion techniques. One infusion technique used diluted OPTISON, and the other used the buoyant properties of OPTISON microspheres by placing the contrast agent between an infusion source and the intravenous site in a vertically oriented extension line (ELT). Myocardial intensities and in vitro microsphere characteristics were analyzed to assess the consistency of microsphere delivery over time. Results: In addition to providing higher myocardial opacification intensity than diluted infusions, ELT infusions provided consistent microsphere concentration, phantom enhancement, and near-peak bolus-level myocardial opacification for 7 to 15 minutes. The myocardial intensity at 3 and 5 minutes in human subjects during ELT infusions (30 mL/h; 2.5 mL) was lower (220 arbitrary units [au] and 165 au, respectively) but not significantly different (P = .3 and .1, respectively) than the peak myocardial intensity (265 au) after bolus administration. Conclusion: This new ELT infusion method provides an acceptable alternative to bolus administration of OPTISON for prolonged myocardial opacification. (J Am Soc Echocardiogr 1999;12:1027-34.)