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We have analyzed the global tropospheric temperature for 1978 to 2002 with the use of passive microwave sounding data from the NOAA series of polar orbiters and the Earth Observing System Aqua satellite. To accurately retrieve the climatic trend, we combined the satellite data with an analytic model of temperature that contains three different time scales: a linear trend and functions that define the seasonal and diurnal cycles. Our analysis shows a trend of +0.22 degrees to 0.26 degrees C per 10 years, consistent with the global warming trend derived from surface meteorological stations. 相似文献
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A Ortega‐Pacheco M Jiménez‐Coello E Gutiérrez‐Blanco KY Acosta‐Viana E Guzmán‐Marín MA Zavala‐Sánchez NE Montalvo‐Beltrán MS Pérez‐Gutiérrez 《Reproduction in domestic animals》2010,45(6):1126-1129
Papaya seeds (Carica papaya Linn) have been found to have a significant effect on sperm characteristics in some mammals, including humans, but no studies have investigated the effects on dogs. In the present study, a significant decrease in sperm concentration was observed in a group of dogs treated with extracts from washed papaya seeds, but no decrease was observed in the group of dogs treated with non‐washed seeds. An important effect of extract components from washed seeds such as fatty acids is probably involved in the reduction of sperm production because of Sertoli cell damage, as has been suggested for langur monkeys. Dilution of the active components in the non‐washed papaya seeds or interference with some of the components may reduce the expected effect on spermatogenesis. This first report on the effects of a chloroformic extract of papaya seeds in dogs suggests that an increased dose is necessary to achieve azoospermia. 相似文献
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Global Warming and Northern Hemisphere Sea Ice Extent 总被引：1，自引：0，他引：1
Vinnikov KY Robock A Stouffer RJ Walsh JE Parkinson CL Cavalieri DJ Mitchell JF Garrett D Zakharov VF 《Science (New York, N.Y.)》1999,286(5446):1934-1937
Surface and satellite-based observations show a decrease in Northern Hemisphere sea ice extent during the past 46 years. A comparison of these trends to control and transient integrations (forced by observed greenhouse gases and tropospheric sulfate aerosols) from the Geophysical Fluid Dynamics Laboratory and Hadley Centre climate models reveals that the observed decrease in Northern Hemisphere sea ice extent agrees with the transient simulations, and both trends are much larger than would be expected from natural climate variations. From long-term control runs of climate models, it was found that the probability of the observed trends resulting from natural climate variability, assuming that the models' natural variability is similar to that found in nature, is less than 2 percent for the 1978-98 sea ice trends and less than 0.1 percent for the 1953-98 sea ice trends. Both models used here project continued decreases in sea ice thickness and extent throughout the next century. 相似文献
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LIU Qiang HUANG Ying-xiang WANG Cong DONG Sheng College of Animal Science Veterinary Medicine Shanxi Agricultural University Taigu Shanxi Province China Karl Dawson Worldwide Research Alltech INC. Nicholasville KY MIAO Chao-hua GAO Deng-hong Beijing Alltech Biological Products Co. Ltd China 《家畜生态》2007,(5)
选用35头处于干奶期40d、泌乳期相近和上胎平均日产奶量20kg的荷斯坦奶牛,采用完全随机区组设计分为7组,即:对照组,基础日粮(不加硒);试验组1、2、3添加亚硒酸钠,分别在基础日粮中加硒7.5mg/d、15mg/d和22.5mg/d;试验组4、5、6添加赛乐硒,分别在基础日粮中加硒7.5mg/d、15mg/d和22.5mg/d,研究赛乐硒和无机硒对奶牛发情周期生殖激素分泌和繁殖性能的影响。结果表明:赛乐硒较无机硒显著提高了发情周期促性腺激素释放激素、促卵泡素、促黄体素、雌二醇和孕酮含量,显著提高了受配率和受胎率,缩短了胎衣排出周期,促进母牛正常发情。适宜补硒量为15 mg/d。 相似文献
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