中国蒙药资源可持续利用现状和对策

蒙药是蒙医师用于防治疾病的药物,是蒙医药事业发展的物质基础。蒙医药事业的可持续发展必须保障药材的质量和供应。随着蒙药资源使用量的增加和蕴藏量的减少,蒙药资源的可持续利用显得越来越重要。因此,一定要重视蒙药资源的可持续利用研究。文章着重介绍了蒙药资源可持续利用情况。     

Equatorial X-ray Emissions: Implications for Jupiter's High Exospheric Temperatures

Observations with the High Resolution Imager on the Rontgensatellit reveal x-ray emissions from Jupiter's equatorial latitudes. The observed emissions probably result from the precipitation of energetic (>300 kiloelectron volts per atomic mass unit) sulfur and oxygen ions out of Jupiter's inner radiation belt. Model calculations of the energy deposition by such heavy ion precipitation and of the resulting atmospheric heating rates indicate that this energy source can contribute to the high exospheric temperatures(>800 kelvin at 0.01 microbar) measured by the Galileo probe's Atmospheric Structure Instrument. Low-latitude energetic particle precipitation must therefore be considered, in addition to other proposed mechanisms such as gravity waves and soft electron precipitation, as an important source of heat for Jupiter's thermosphere.     

Interregional Spillovers in Regional Impact Assessment: New Mexico,Texas, and the Supreme Court

ABSTRACT Input-output models are frequently used to estimate impacts, benefits or damages from some event. These analytic models and the questions they are designed to answer are usually based on political definitions of regions. However the true impacts propagate according to the actual spatial pattern of the regional economy. Because of the divergence between the political regions used for analysis and the economic regions on the ground, the economic impacts which spill over political boundaries can sometimes become analytically important. This paper applies these concepts to a case study of allocating irrigation water from the Pecos River in Texas and New Mexico. The U.S. Supreme Court has ruled that New Mexico used water belonging to Texas. Our analysis suggests that the spillover benefits to Texas from New Mexico's use of the water might equal or exceed the benefits which Texas would have gotten from using the water itself. Texas might be better off because New Mexico took its water.     

The infectivity by different routes of exposure and shedding rates of Aeromonas salmonicida subsp. salmonicida in Atlantic salmon, Salmo salar L., held in sea water

Abstract. The infectivity of the bacterial fish pathogen Aeromonas salmonicida subsp. salmonicida to Atlantic salmon, Salmo salar L., in sea water was investigated and found to be similar to that reported for fresh water. The minimal infective dose in short duration bath exposures (1–3 days) was 10⁴ colony-forming units (cfu) per ml, while prolonged exposure for three weeks, but not for 1 week, produced infection with 10² cfu/ml. Intragastric intubation of A. salmonicida established infection with doses of >10⁵ cfu. Release of bacteria from dead or morbid infected fish was monitored and found to be in the order of 10⁵–10⁸ cfu/fish/h. These results emphasize the importance of removing dead fish from farm sites.     

Effect of initial age variation on production of Florida red tilapia fry under intensive, brackishwater tank culture

Abstract. Growth and survival were compared among uniform- and mixed-age groups of Florida red tilapia fry during sex reversal in brackishwater (12ppt) tanks, under commercial-scale hatchery conditions. Three treatment groups of post-yolksac (i.e. free-swimming) stage fry of different age compositions were compared: (1) 100% fry collected at the free-swimming stage (FSF); (2) 100% fry obtained through artificial incubation of eggs and non-swimming sacfry (ENS); and (3) a mixed group consisting of 50% of each type (FSF+ENS). Fry were stocked into 530–1 cylindroconical tanks at a density of seven fish/l (3700/tank) and reared on an androgen-treated diet for 30 days. While specific growth rates (range = 17·1–17·8% body weight/day) did not differ (P > 0·05) among treatments, significant (P < 0.05) differences were observed for survival and feed conversion ratio (FCR). ENS showed highest survival (76·8%) and lowest FCR (1·14), FSF showed intermediate survival (59·2%) and FCR(l·33), while the mixed-age group (FSF+ENS) showed lowest survival (38·5%) and highest FCR (1·70). Under all treatments, a majority of fry losses were attributed to cannibalism. A highly significant ( P < 0·001) negative regression between survival and coefficient of variation of initial weights (CV = SD/) indicated that cannibalism was reduced by minimizing age/size variation at stocking. The CV of initial weight may be a useful parameter for predicting fry survival under intensive tank culture.     

Heterogeneity of extracellular proteases produced by different isolates of Aeromonas hydrophila and A. sobria pathogenic for fish

Abstract. Ten isolates of Aeromonas hydrophila and two of A. sobria were investigated with regard to elastase and caseinase production, and the pI, heat and EDTA sensitivity of extracellular caseinase enzymes. An extreme degree of heterogeneity amongst the strains was observed. In isoelectricfocusing, the ECP of the various strains possessed between 19 and 31 proteins, and the number of extracellular proteases ranged from one to 12. Similarities between strains using one criterion of comparison (e.g. IEF patterns) did not hold true by other criteria (e.g. heat or EDTA sensitivity of proteases).