排序方式: 共有87条查询结果,搜索用时 15 毫秒
51.
Phillips RJ Zuber MT Smrekar SE Mellon MT Head JW Tanaka KL Putzig NE Milkovich SM Campbell BA Plaut JJ Safaeinili A Seu R Biccari D Carter LM Picardi G Orosei R Mohit PS Heggy E Zurek RW Egan AF Giacomoni E Russo F Cutigni M Pettinelli E Holt JW Leuschen CJ Marinangeli L 《Science (New York, N.Y.)》2008,320(5880):1182-1185
The Shallow Radar (SHARAD) on the Mars Reconnaissance Orbiter has imaged the internal stratigraphy of the north polar layered deposits of Mars. Radar reflections within the deposits reveal a laterally continuous deposition of layers, which typically consist of four packets of finely spaced reflectors separated by homogeneous interpacket regions of nearly pure ice. The packet/interpacket structure can be explained by approximately million-year periodicities in Mars' obliquity or orbital eccentricity. The observed approximately 100-meter maximum deflection of the underlying substrate in response to the ice load implies that the present-day thickness of an equilibrium elastic lithosphere is greater than 300 kilometers. Alternatively, the response to the load may be in a transient state controlled by mantle viscosity. Both scenarios probably require that Mars has a subchondritic abundance of heat-producing elements. 相似文献
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OBJECTIVE: To assess effects of treatment with phenylbutazone (PBZ) or a combination of PBZ and flunixin meglumine in horses. ANIMALS: 24 adult horses. PROCEDURE: 13 horses received nonsteroidal antiinflammatory drugs (NSAIDs) in a crossover design. Eleven control horses were exposed to similar environmental conditions. Treated horses received PBZ (2.2 mg/kg, PO, q 12 h, for 5 days) and a combination of PBZ and flunixin meglumine (PBZ, 2.2 mg/kg, PO, q 12 h, for 5 days; flunixin meglumine, 1.1 mg/kg, IV, q 12 h, for 5 days). Serum samples were obtained on day 0 (first day of treatment) and day 5, and total protein, albumin, and globulin were measured. RESULTS: 1 horse was euthanatized with severe hypoproteinemia, hypoalbuminemia, and colitis during the combination treatment. Comparisons revealed no significant difference between control horses and horses treated with PBZ alone. There was a significant difference between control and treated horses when administered a combination of PBZ and flunixin meglumine. Correction for horses with values >2 SDs from the mean revealed a significant difference between control horses and horses administered the combination treatment, between control horses and horses administered PBZ alone, and between horses receiving the combination treatment and PBZ alone. Gastroscopy of 4 horses revealed substantial gastric ulcers when receiving the combination NSAID treatment. CONCLUSIONS AND CLINICAL RELEVANCE: Analysis of results of the study indicates the need for caution when administering a combination NSAID treatment to horses because the detrimental effects may outweigh any potential benefits. 相似文献
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Cusser Sarah Grando Carolina Zucchi Maria Imaculada López-Uribe Margarita M. Pope Nathaniel S. Ballare Kimberly Luna-Lucena Danielle Almeida Eduardo A. B. Neff John L. Young Kenneth Jha Shalene 《Landscape Ecology》2019,34(7):1825-1836
Landscape Ecology - Bees are the most important pollinators of crops worldwide. For most bees, patches of semi-natural habitat within or adjacent to crops can provide important nesting and food... 相似文献
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Harran N d'Anjou MA Dunn M Beauchamp G 《The Canadian veterinary journal. La revue veterinaire canadienne》2011,52(9):999-1003
The purposes of this retrospective study were to assess the prevalence of gallbladder sludge (GBS) in a population of cats presented for abdominal ultrasound in a teaching hospital and to determine its association with increased serum alanine aminotransferase (ALT), alkaline phosphatase (ALP), and total bilirubin (TB). Gallbladder sludge was detected in 152 (14%) of the cats undergoing abdominal ultrasound between 2004 and 2008. This population was compared to a control group of 32 cats without GBS. Alanine aminotransferase, ALP, and TB mean values were significantly higher in cats with GBS than in controls (P ≤ 0.0005) and odds for increased values in cats with GBS were 4.2 [95% confidence interval (CI): 1.6 to 11.0], 9.5 (95% CI: 2.2 to 41.7), and 4.1 (95% CI: 1.5 to 11.5), respectively (P ≤ 0.007). In conclusion, GBS is an uncommon ultrasonographic finding in cats that is predictive of increased liver enzymes and TB. More studies are needed to establish potential links between GBS and hepatobiliary disease in cats. 相似文献
55.
Heintz N 《Science (New York, N.Y.)》2003,301(5629):59-60
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OBJECTIVE: To assess changes in systemic hydration, concentrations of plasma electrolytes, hydration and physical properties of colonic contents and feces, and gastrointestinal transit in horses with access to large amounts of grain. ANIMALS: 6 horses with right dorsal colon (RDC) fistulas. PROCEDURE: In a crossover design, horses were alternately fed 1 of 3 diets: orchard grass hay ad libitum after being adapted to this diet for at least 5 days, orchard grass hay ad libitum and 4.55 kg of grain offered every 12 hours after being adapted to orchard grass hay ad libitum for at least 5 days, or orchard grass hay ad libitum and 4.55 kg of grain offered every 12 hours after being adapted to this diet for at least 5 days. Physical examinations were performed and samples of blood, colonic contents, and feces were collected every 6 hours during a 48-hour observation period. RESULTS: Grain ingestion had several effects, including changes in the concentrations of electrolytes in plasma; RDC contents became more homogenous, dehydrated, foamy, and less dense; RDC contents flowed spontaneously when the cannula was opened; RDC contents expanded when heated in an oven; and feces became fetid and less formed. Horses did not have any clinical signs of colic, endotoxemia, or laminitis. CONCLUSIONS AND CLINICAL RELEVANCE: Changes observed in the colonic contents and feces may be explained by the large amounts of hydrolyzable carbohydrates provided by grain. Access to large amounts of grain may increase the risk of tympany and displacement of the large intestine. 相似文献
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Wereszka MM White NA Furr MO 《Journal of the American Veterinary Medical Association》2007,230(8):1195-1200
OBJECTIVE: To identify factors associated with outcome (ie, survival and return to function) following treatment of horses with septic tenosynovitis. DESIGN: Retrospective case series. ANIMALS: 51 horses with septic tenosynovitis. PROCEDURES: Information was obtained from medical records and through follow-up conversations with owners. Factors analyzed for an association with outcome included affected limb, etiology, duration of clinical signs prior to examination, presence of complications, primary treatment, secondary treatments, number of surgical procedures, and hospitalization time. RESULTS: Concurrent complications were identified in 41 (80%) horses. The primary treatment consisted of through-and-through lavage in 26 (51%) horses, tenoscopy in 20 (39%), and tenosynoviotomy combined with lavage in 5 (10%). Forty (78%) horses were discharged, and 37 (73%) survived at least 1 year after surgery; 21 of the 37 (57%) returned to their previous or a higher level of performance. Percentages of horses that survived 1 year after discharge and percentages that returned to their intended use did not vary significantly among treatments. Horses with tendon rupture or sepsis of an adjacent joint were significantly less likely to survive. Horses with tendon injury or pannus were significantly less likely to return to their intended use. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggested that various factors were associated with outcome in horses with septic tenosynovitis. However, surgical technique was not found to be associated with survival rate or rate of return to intended use. 相似文献
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Isotopologue fractionation during microbial reduction of N2O within soil mesocosms as a function of water-filled pore space 总被引:1,自引:1,他引:0
Malee Jinuntuya-Nortman Robin L. Sutka Peggy H. Ostrom Hasand Gandhi Nathaniel E. Ostrom 《Soil biology & biochemistry》2008,40(9):2273
Isotopologue analyses of N2O within soil mesocosm experiments were used to evaluate the influence of N2O reduction on isotope fractionation. We investigated fractionation during N2O reduction at 60%, 80% and 100% water-filled pore space (WFPS) and found net isotope effects (NIE) for δ15N of 4.2–7.8‰, δ18O of 12.5–19.1‰, δ15Nα of 6.4–9.7‰ and δ15Nβ of 2.0–5.9‰. Consequently, N2O reduction has a marked affect on isotopologue values and the importance of this process in flux chamber studies should not be ignored. With the exception of SP (the difference between the δ15N of the central, α, and terminal, β, atoms) inverse relationships between the NIE, reaction rate and reaction rate constant and WFPS were observed. Isotopic discrimination in SP during N2O reduction was small and the average NIE for the treatments varied between 2.9‰ and 4.5‰. A strong correlation was evident between δ18O vs. δ15N and δ18O vs. δ15Nα during reduction with slopes of 2.6 and 1.9, respectively, which contrasts from a slope of <1 commonly observed for mixing between soil-derived and atmospheric N2O in flux chambers. 相似文献