[Research status and rapid detection methods of antibiotic residues in agricultural products]. / å†œäº§å“æŠ—ç”Ÿç´ æ®‹ç•™çŽ°çŠ¶åŠå¿«é€Ÿæ£€æµ‹æ–¹æ³•ç ”ç©¶è¿›å±•.

Antibiotics are widely utilized in agriculture for the prevention and treatment of animal diseases. How-ever, the abuse and overuse of antibiotics progressively increase the risks of antibiotic residues and antibiotic resis-tance. The bioaccumulation and biomagnification of antibiotics through food chains will negatively affect ecological safety, and finally threaten human health. There are many shortages of traditional antibiotic detection techniques, such as complex procedures, complicated operation and time consuming, and thus are difficult to meet the demand of instant, efficient and accurate on-site detection. Therefore, it is crucial to develop rapid detection techniques of antibiotics to manage the application of antibiotics in agriculture. We reviewed the utilization, and management of antibiotics in animal husbandry, residual characteristics, and potential hazards of antibiotics in agricultural products, summarized the advancements in rapid detection techniques of antibiotics in agricultural products over the past five years, compared the advantages and disadvantages of different rapid detection techniques, and prospected the future development in this area. This review would provide a valuable reference to the control and point-of-care test of antibiotics in agricultural products.

[Research progress on sensitivity of indices for ecotoxicological assays using rotifers.] / è½®è™«ç”Ÿæ€æ¯’ç†å­¦æµ‹è¯•æŒ‡æ ‡çš„æ•æ„Ÿæ€§ç ”ç©¶è¿›å±•.

Human activities have severely polluted environments during industrialization. Rotifers are commonly used as model species for ecotoxicological assays. The sensitivities of ecotoxicological indices of rotifers highly depend on different pollutants. We summarized available ecotoxicological indices of rotifers, and reviewed their sensitivity to commonly investigated pollutants. Under the stress of heavy metals, the life-table demographic parameters, physiological and biochemical indices generally show high sensitivity. In response to persistent organic pollutants, sexual indices generally show higher sensitivity than asexual ones. Some studies showed that swimming speed revealed higher sensitivity after exposure to several pollutants compared with life-table demographic and population growth indices. We suggested to consider swimming speed of rotifer as an alternative index for ecotoxicological assays. Overall, this study would provide a guideline for rotifer ecotoxicological studies in the future.

[CO, release characteristics from Stipa baicalensis meadow steppe in the Hulunbeir region, Inner Mogolia, China].

Based on the measurement of soil CO2 evolution with the Li-8150 from June 2009 to June 2010, the characteristics of soil CO2 flux from the Stipa baicalensis meadow steppe in the Hulunbeir, Inner Mongolia were analyzed. The daily dynamics of soil respiration rate in this study area presented a peak curve in growing season, the daily maximum value appeared in 13:00-15:00 p. m., while the minimum value appeared in 5:00-6:00 a. m. The soil respiration had obviously seasonal dynamics, similar with the dynamics of soil temperature and soil water content. The relationships of soil respiration with soil temperature and soil water content could be better expressed with linear or exponential-power equation. Using the Van' t Hoff exponential equation to fit soil respiration and soil temperature, the results showed that they all had good exponential regression relationships in growing season and in non-growing season. Q10 was slightly different at different depths, varying from 1.68 to 2.14 in growing season and from 3.03 to 3.60 in non-growing season. The effect of soil temperature on soil respiration was more sensitive in non-growing season than in growing season. There was significant a correlation between soil respiration and soil water content at the depth of 10 cm. The annual soil CO2 fluxes were 488.47 g C x a(-1) and 507.20 g C x a(-1) in 2009 and 2010, respectively. The contribution of soil respiration in growing season to the annual soil CO2 flux was about 90%.

[Spatiotemporal characteristics of MODIS NDVI in Hulunber Grassland].

Time-series MODIS NDVI datasets from 2000 to 2008 were used to study the spatial change trend, fluctuation degree, and occurrence time of the annual NDVImax of four typical grassland types, i.e., lowland meadow, temperate steppe, temperate meadow steppe, and upland meadow, in Hulunber Grassland. In 2000-2008, the vegetation in Hulunber Grassland presented an obvious deterioration trend. The mean annual NDVImax of the four grassland types had a great fluctuation, especially in temperate steppe where the maximum change in the mean value of annual NDVImax approximated to 50%. As for the area change of different grade grasslands, the areas with NDVImax between 0.4 and 1 accounted for about 91% of the total grassland area, which suggested the good vegetation coverage in the Grassland. However, though the areas with NDVImax values in (0.4, 0.8) showed an increasing trend, the areas with NDVImax values in (0.2, 0.4) and (0.8, 1) decreased greatly in the study period. Overall, the deteriorating grassland took up about 66.25% of the total area, and the restoring grassland took the rest. There was about 62.85% of the grassland whose NDVImax occurred between the 193rd day and the 225th day in each year, indicating that this period was the most important vegetation growth season in Hulunber Grassland.