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Wormcasts of Allolobophora caliginosa have been shown to have higher phosphatase activity than occurs in uningested soil, resulting in an increase in inorganic P released by mineralization of organic P. This paper describes similar observations on organic wastes which may be used for vermiculture. Besides A. caliginosa, three species which will feed on dung or other organic substrates were investigated, Eisenia foetida, Dendrobaena veneta and Lumbricus rubellus. When cow dung was used as a substrate, background phosphatase activity was too high for the effects of earthworm activity to be detected and a culture medium was therefore developed from sterilized paper waste sludge with added phytin. Phosphatase activity, assayed by a modified Hoffman method, was higher in the presence of all four earthworm species than in controls. It showed two peaks in relation to pH, at 3–5 and 9–10. The former is attributed to microbial activity and the latter to microbial activity or earthworm alkaline phosphatase. After 1 month, cultures of paper waste sludge with phytin contained about twice as much water soluble P when worms were present than in their absence. 相似文献
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K. F. Ortved S. Witte K. Fleming J. Nash A. R. Woolums J. F. Peroni 《Equine Veterinary Education》2008,20(7):357-361
This reports describes the surgical management of a horse evaluated for recurrent colic. These frequent colic episodes were attributed by exclusion to an abnormally enlarged spleen (idiopathic splenomegaly). Splenectomy was elected and performed with a laparoscopic assisted technique. The advantages observed by using this surgical approach were a clear view of the visceral aspect of the spleen and consequently an accurate dissection of the hilus of the spleen and associated vasculature. Ultimately the laparoscopic technique allowed the surgeons to reduce the size of the laparotomy incision required to remove the spleen and the overall invasiveness of the procedure. The horse recovered well from the procedure and ultimately returned to the previous level of competitiveness. 相似文献
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Concerns about the long-term sustainability of overstocked dry conifer forests in western North America have provided impetus for treatments designed to enhance their productivity and native biodiversity. Dense forests are increasingly prone to large stand-replacing fires; yet, thinning and burning treatments, especially combined with other disturbances such as drought and grazing, may enhance populations of colonizing species, including a number of non-native species. Our study quantifies plant standing crop of major herbaceous species across contrasting stand structural types representing a range in disturbance severity in northern Arizona. The least disturbed unmanaged ponderosa pine stands had no non-native species, while non-native grasses constituted 7–11% of the understory plant standing crop in thinned and burned stands. Severely disturbed wildfire stands had a higher proportion of colonizing native species as well as non-native species than other structural types, and areas protected from grazing produced greater standing crop of native forbs compared to grazed unmanaged stands. Standing crop of understory plants in low basal area thinned and burned plots was similar to levels on wildfire plots, but was comprised of fewer non-native graminoids and native colonizing plants. Our results also indicate that size of canopy openings had a stronger influence on standing crop in low basal area plots, whereas tree density more strongly constrained understory plant standing crop in dense stands. These results imply that treatments resulting in clumped tree distribution and basal areas <10 m2 ha−1 will be more successful in restoring native understory plant biomass in dense stands. Multiple types and severity of disturbances, such as thinning, burning, grazing, and drought over short periods of time can create greater abundance of colonizing species. Spreading thinning and burning treatments over time may reduce the potential for non-native species colonization compared to immediately burning thinned stands. 相似文献
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Jordyn M Boesch DVM Robin D Gleed BVSc Diplomate ACVA Jason W Gagne BS Kyla Ortved DVM Nathan L Dykes DVM Diplomate ACVR & William A Horne DVM PhD Diplomate ACVA 《Veterinary anaesthesia and analgesia》2009,36(6):567-573
ObservationsA 1-month-old Nubian goat presented for sialocyst resection. Physical examination and bloodwork were unremarkable. While pre-oxygenating, the goat was sedated with midazolam and morphine (0.1 mg kg?1 each) intravenously (IV). General anesthesia was induced 5 minutes later with 1.7 mg kg?1 propofol. Sevoflurane was administered in oxygen without assisted ventilation via a cuffed orotracheal tube. Throughout the first 85 minutes of anesthesia, the goat was well-oxygenated (SpO2, ≥97%), ventilating adequately (Pe′CO2, 36–48 mmHg), and had normal mean arterial blood pressure (MAP, 60–85 mmHg). Blood-gas values at 45 minutes were consistent with adequate ventilation on oxygen. At 75 minutes, the goat moved in response to surgical stimulation, requiring additional propofol (0.4 mg kg?1). After 10 minutes, MAP dropped precipitously to 40 mmHg and frequent multiform premature ventricular contractions (PVCs) were observed. Crystalloids, hetastarch, and dopamine (5 μg kg?1 minute?1) were administered to correct the hypotension. Arterial blood-gas analysis revealed that the goat had become hypoxemic (PaO2, 50 mmHg). Intermittent positive pressure ventilation (IPPV) was initiated. Subsequent blood-gas analysis did not show significant improvement in PaO2 (53 and 56 mmHg, respectively). Occasional PVCs were observed thereafter. Surgery ended, and sevoflurane and IPPV were discontinued. The goat was extubated within 7 minutes and received 100% oxygen by mask. Diffuse crackles were ausculted over both hemithoraces. Suspecting pulmonary edema, furosemide (1 mg kg?1) was administered IV. Radiographs taken immediately post-operatively revealed a severe, caudodorsal airspace (alveolar) pattern, confirming the diagnosis. Respiration improved considerably within an hour with nasal oxygen and two additional doses of furosemide.ConclusionsThe goat developed acute, drug-induced, noncardiogenic pulmonary edema in response to the second dose of propofol. 相似文献
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Laparoscopic‐Guided Compared to Skilled Instructor Support for Student Rectal Examination Training Using Live Horses in the Veterinary Curriculum 
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下载免费PDF全文 Rolfe M. Radcliffe DVM Diplomate ACVS & ACVECC Alison C. Manchester DVM Hussni O. Mohammed BVSc MPVM PhD Kyla Ortved DVM Diplomate ACVS Heidi L. Reesink VMD Diplomate ACVS Lauren V. Schnabel DVM Diplomate ACVS Hayley M. Lang DVM Peter V. Scrivani DVM Diplomate ACVR Susan L. Fubini DVM Diplomate ACVS 《Veterinary surgery : VS》2015,44(3):352-358
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Vegetation patterns at the landscape scale are shaped by myriad processes and historical events, and understanding the relative importance of these processes aids in predicting current and future plant distributions. To quantify the influence of different environmental and anthropogenic patterns on observed vegetation patterns, we used simultaneous autoregressive modeling to analyze data collected by the Carnegie Airborne Observatory over Santa Cruz Island (SCI; California, USA). SCI is a large continental island, and its limited suite of species and well documented land use history allowed us to consider many potential determinants of vegetation patterns, such as topography, substrate, and historical grazing intensity. As a metric of vegetation heterogeneity, we used the normalized difference vegetation index (NDVI) stratified into three vegetation height classes using LiDAR (short, medium, and tall). In the SAR models topography and substrate type were important controls, together explaining 8–15 % of the total variation in NDVI, but historical grazing and spatial autocorrelation were also key components of the models, together explaining 17–21 % of the variation in NDVI. Optimal spatial autocorrelation distances in the short and medium height vegetation models (600–700 m) were similar to the home range sizes of two crucial seed dispersers on the island– the island fox (Urocyon littoralis santacruzae) and the island scrub-jay (Aphelocoma insularis)—suggesting that these animals may be important drivers of the island’s vegetation patterns. This study highlights the importance of dynamic processes like dispersal limitation and disturbance history in determining present-day vegetation patterns. 相似文献