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81.
Steven D. Allison David S. LeBauer Randy Reyes Tri M. Tran 《Soil biology & biochemistry》2009,41(2):293-302
Climate warming and associated increases in nutrient mineralization may increase the availability of soil nitrogen (N) in high latitude ecosystems, such as boreal forests. These changes in N availability could feed back to affect the decomposition of litter and organic matter by soil microbes. Since fungi are important decomposers in boreal forest ecosystems, we conducted a 69-day incubation study to examine N constraints on fungal decomposition of organic substrates common in boreal ecosystems, including cellulose, lignin, spruce wood, spruce needle litter, and moss litter. We added 0, 20, or 200 μg N to vials containing 200 mg substrate in factorial combination with five fungal species isolated from boreal soil, including an Ascomycete, a Zygomycete, and three Basidiomycetes. We hypothesized that N addition would increase CO2 mineralization from the substrates, particularly those with low N concentrations. In addition we predicted that Basidiomycetes would be more effective decomposers than the other fungi, but would respond weakly or negatively to N additions. In support of the first hypothesis, cumulative CO2 mineralization increased from 635 ± 117 to 806 + 108 μg C across all fungal species and substrates in response to 20 μg added N; however, there was no significant increase at the highest level of N addition. The positive effect of N addition was only significant on cellulose and wood substrates which contained very little N. We also observed clear differences in the substrate preferences of the fungal species. The Zygomycete mineralized little CO2 from any of the substrates, while the Basidiomycetes mineralized all of the substrates except spruce needles. However, the Ascomycete (Penicillium) was surprisingly efficient at mineralizing spruce wood and was the only species that substantially mineralized spruce litter. The activities of β-glucosidase and N-acetyl-glucosaminidase were strongly correlated with cumulative respiration (r = 0.78 and 0.74, respectively), and Penicillium was particularly effective at producing these enzymes. On moss litter, the different fungal species produced enzymes that targeted different chemical components. Overall, our results suggest that fungal species specialize on different organic substrates, and only respond to N addition on low N substrates, such as wood. Furthermore, the response to N addition is non-linear, with the greatest substrate mineralization at intermediate N levels. 相似文献
82.
83.
Boudrieau RJ McCarthy RJ Sprecher CM Künzler TP Keating JH Milz S 《American journal of veterinary research》2006,67(7):1258-1265
OBJECTIVE: To determine the material properties of Slocum TPLO plates and assess the soft tissue reaction adjacent to these plates in dogs that had undergone tibial plateau leveling osteotomy (TPLO). SAMPLE POPULATION: 3 new TPLO plates, 8 retrieved TPLO plates, and 1 new Synthes dynamic compression plate. PROCEDURES: Metallurgic analyses were performed. Tissue samples were obtained from areas adjacent to retrieved plates and submitted for histologic examination. RESULTS: All of the TPLO plates had a 2-phase microstructure consisting of austenite and ferrite in various amounts. Residua, inclusions, and cavities were seen during microscopic examination of the plate surface. The major differences between new and retrieved TPLO plates were the presence of small gaps separating many inclusions from the surrounding matrix and the presence of various-sized pits on the surface of the retrieved plates. The dynamic compression plate had a nearly pure austenitic structure and was largely free from residua, inclusions, and cavities. Histologic examination of tissue samples obtained from areas adjacent to retrieved TPLO plates revealed intra- and extracellular particulate debris. Two types of particles (one consisting of chromium, nickel, molybdenum, and iron and the other consisting of aluminum and silicon) were seen. CONCLUSIONS AND CLINICAL RELEVANCE: Results determined that new and retrieved TPLO plates were manufactured from 316L stainless steel and produced by a casting process, but not all plates met specifications for chemical composition of cast surgical implants (American Society for Testing Materials standard F745); tissues surrounding retrieved plates had evidence of adverse reactions, probably as a result of plate corrosion. 相似文献
84.
Jiff Randy Caban Saranya Kuppusamy Jang Hwan Kim Young-Eun Yoon Song Yeob Kim Yong Bok Lee 《Water, air, and soil pollution》2018,229(3):104
Veterinary antibiotics like sulfonamides are frequently detected in arable lands and they can potentially contaminate food crops. It is thus of great importance to identify strategies to reduce food crops’ uptake of antibiotics. For the first time, using a pot culture experiment, sulfathiazole (STZ) uptake by lettuce (Lactuca sativa L.) grown in antibiotic-contaminated soils (10 and 100 mg STZ kg?1 soil) and treated with (in)organic amendments, namely chemical fertilizer (NPK), compost, and hairy vetch, was investigated. Subsequent enhanced plant growth was witnessed when using hairy vetch treatment. The amount of antibiotic uptake was significantly reduced to 5 and 33% with hairy vetch application compared to compost or NPK application at 10 and 100 mg kg?1 STZ, respectively. The total amounts of accumulated STZ in plant parts increased as the levels of STZ contaminated in soils were increased. STZ was much more abundant in the roots than the leaves. Within 30 days, the extractable STZ in the treated soils—especially with hairy vetch—diminished considerably to concentrations that are frequently detected in arable soils. We conclude that utilization of green manure (cover crop—hairy vetch) is a viable strategy for safer crop production in antibiotic-contaminated soils. 相似文献
85.
Skeldon NC Gerber KL Wilson RJ Cunnington SJ 《Journal of Feline Medicine and Surgery》2010,12(12):960-966
The significance of mastocytaemia in cats is different from that in dogs because it appears exclusively associated with mast cell neoplasia. The prevalence of mastocytaemia was 0.05% of all feline submissions to a private laboratory and 43% in cats with mast cell neoplasia. None of 30 healthy cats had mastocytaemia. There was no sex bias or significant age difference between mastocytaemic and non-mastocytaemic cats with mast cell tumours (MCT). Buffy coat (BC) examination was the best screening method for detection of mastocytaemia but direct blood film examination was more accurate for quantifying degree of mastocytaemia. BC examination should be performed in all cases of suspected/known mast cell neoplasia as mastocytaemia was missed on nearly 30% of occasions when direct film examination only was used. Mastocytaemia was associated with decreased haematocrit (HCT) but not with other haematological parameters. Mastocytaemic cats can survive significant lengths of time (up to 27 months) even when splenectomy is not performed. 相似文献
86.
Lynn RC Hepler DI Kelch WJ Bertone JJ Smith BL Vatistas NJ 《Veterinary therapeutics : research in applied veterinary medicine》2004,5(2):128-138
A topical 1% diclofenac liposomal cream proved to be safe, easy to use, and effective in reducing equine lameness caused by degenerative joint disease. Diclofenac liposomal cream was shown to reduce lameness as graded by owners and veterinarians, regardless of the severity or chronicity of the clinical condition. Topical application allowed for more convenient administration than oral or injectable agents, and no clinically relevant hematologic or serum biochemical changes were noted. The liposomal cream provided a delivery system for diclofenac, an NSAID, to achieve therapeutic levels locally with decreased risk for systemic toxicity and side effects and improved targeting of the painful area. 相似文献
87.
Anderson D Kollias-Baker C Colahan P Keene RO Lynn RC Hepler DI 《Veterinary therapeutics : research in applied veterinary medicine》2005,6(1):57-66
The liposomal cream formulation of diclofenac, an NSAID, is an effective, safe, and convenient way to treat localized areas of inflammation in horses. The results of this study reveal urinary and serum concentrations of diclofenac following topical administration of 1% liposomal diclofenac cream for 10 days at the labeled dose and at 2X and 4X the labeled dose. These results demonstrate the slow absorption and elimination of 1% liposomal diclofenac cream and may be useful when estimating the withdrawal time needed before a competition in order to prevent an inadvertent positive drug test. 相似文献
88.
Herman RA Phillips AM Collins RA Tagliani LA Claussen FA Graham CD Bickers BL Harris TA Prochaska LM 《Journal of agricultural and food chemistry》2004,52(9):2726-2734
Maize (Zea mays L.) plants have been transformed to express a Cry1F insecticidal crystal protein originally isolated from Bacillus thuringiensis Berliner. This protein controls lepidopteran pests of maize, including the European corn borer, Ostrinia nubilalis (Hübner). As part of the safety assessment for crops containing transgenes, a compositional analysis of the food and feed is conducted. This analysis is designed to detect unintended changes in the nutrient and antinutrient content of the raw commodities produced by the crop due to the insertion of the genes into the genomic DNA of the plant (pleotropic effects). Samples of transgenic and nontransgenic maize forage and grain were collected from six field sites located in the U.S. and Canada. Forage samples were analyzed for proximates and minerals, and grain was further analyzed for fatty acids, amino acids, vitamins, secondary metabolites, and antinutrients. Results demonstrated that maize expressing the Cry1F protein was equivalent to nontransgenic maize with respect to these important components. Comparison of the variability within the nontransgenic and transgenic hybrid, as compared to composition values reported in the literature, suggest that factors other than transgenes may contribute more substantially to the composition of crops. 相似文献
89.
Randy Spronk 《兽医导刊》2019,(3)
正美国有很多猪肉行业的机构,它们具有不同的职能,负责不同的领域,但是他们共同为猪肉行业争取合理的立法和监管,开发和捍卫出口市场机会,有助于保护养殖者的生计,以及根除和净化疫病,美国猪肉生产者一直致力于做正确的事情,推动猪肉行业的发展。 相似文献
90.
Ploetz RC 《Phytopathology》2006,96(6):648-652
ABSTRACT The world's oldest ecosystems are found in the tropics. They are diverse, highly evolved, but barely understood. This and subsequent papers describe diseases of tropical, perennial plants that are caused by Fusarium spp. Many of these are economically significant, difficult to manage, and of scientific interest. Some represent coevolved patho-systems (e.g., Panama disease, tracheomycosis of coffee, fusariosis of pineapple, and Fusarium wilt of oil palm), whereas others may be new-encounter diseases or are caused by generalist pathogens (cushion gall of cacao). New vector relationships are evident in other pathosystems (e.g., mango malformation), and two or more pathogens have been shown to cause some of the diseases (Panama disease and tracheomycosis of coffee). More work on these pathosystems is warranted as they could reveal much about the evolution of plant pathogens and the important diseases they cause. 相似文献