The effects of a diet containing Hanseniaspora opuntiae C21 on growth and digestive enzyme activity were estimated in juvenile Apostichopus japonicus. Groups of sea cucumbers were fed diets containing H. opuntiae C21 at 0(control), 10 4, 10 5, and 10 6 CFU(colony-forming units)/g feed. Results showed that after 45 d the specific growth rate(SGR) of sea cucumbers fed a C21-supplemented diet at 10 4 CFU/g feed was significantly higher than that of the control( P 0.05). Intestinal trypsin and lipase activities were significantly enhanced by C21 administration at 10 4 and 10 5 CFU/g feed compared with the control( P 0.05). After feeding for 23–42 d, C21 was demonstrated by denaturing gradient gel electrophoresis to be present in the intestine of sea cucumbers. In addition, after feeding the C21-supplemented diets for 15 d, the sea cucumbers were switched to an unsupplemented diet and C21 was confirmed to be capable of colonizing the intestine for at least 31 d after cessation of feeding. In conclusion, C21 was shown to successfully colonize the intestine of juvenile A. japonicus via dietary supplementation, and improve growth and digestive enzyme activity. 相似文献
Zircon stability in silicate melts—which can be quantitatively constrained by laboratory measurements of zircon saturation—is important for understanding the evolution of magma. Although the original zircon saturation model proposed by Watson and Harrison (Earth Planet Sci Lett 64(2):295–304, 1983) is widely cited and has been updated recently, the three main models currently in use may generate large uncertainties due to extrapolation beyond their respective calibrated ranges. This paper reviews and updates zircon saturation models developed with temperature and compositional parameters. All available data on zircon saturation ranging in composition from mafic to silicic (and/or peralkaline to peraluminous) at temperatures from 750 to 1400 °C were collected to develop two refined models (1 and 2) that may be applied to the wider range of compositions. Model 1 is given by lnCZr(melt) = (14.297 ± 0.308) + (0.964 ± 0.066)·M − (11113 ± 374)/T, and model 2 given by lnCZr(melt) = (18.99 ± 0.423) − (1.069 ± 0.102)·lnG − (12288 ± 593)/T, where CZr(melt) is the Zr concentration of the melt in ppm and parameters M [= (Na + K + 2Ca)/(Al·Si)] (cation ratios) and G [= (3·Al2O3 + SiO2)/(Na2O + K2O + CaO + MgO + FeO)] (molar proportions) represent the melt composition. The errors are at one sigma, and T is the temperature in Kelvin. Before applying these models to natural rocks, it is necessary to ensure that the zircon used to date is crystallized from the host magmatic rock. Assessment of the application of both new and old models to natural rocks suggests that model 1 may be the best for magmatic temperature estimates of metaluminous to peraluminous rocks and that model 2 may be the best for estimating magmatic temperatures of alkaline to peralkaline rocks.
Two modes of regulating the water quality of experimental ponds in indoor raceway culture of Litopenaeus vannamei were evaluated using simple water treatment facilities. A self-made water purifying net, aeration stone, composite microbe
preparation, and Ceratophyllum demersum were placed in the experimental ponds and the culture water was circulated along the raceway inside the pond using a paddle
wheel aerator. In addition, the water quality in the experimental pond was improved by draining effluent from the pipeline
at the bottom of ponds 7 and 8 (mode I) and exchanging the circulating water in pond 10 (mode II) with the reservoir water
in pond 9 using a pump and pipeline. The water quality in the experimental ponds was similar in response to regulation using
mode I or mode II. Water quality parameters in the experimental ponds were controlled within a suitable range by simple facilities
during culture period without using any chemical treatments. The rich content of dissolved oxygen was maintained by the circular
flow and continuous aeration of the pond water. The respective average values of the main water parameters in experimental
ponds 7 and 10 in response to regulation of the water quality using modes I and II were as follows: pH 8.17 and 7.99; DO 5.16
mg/L and 5.97 mg/L; CODMn 18.45 and 12.61 mg/L; TAN (NH3-N) 0.854 mg/L (0.087 mg/L) and 0.427 mg/L (0.012 mg/L); NO2-N 0.489 mg/L and 0.337 mg/L. Moreover, the average body length and body weight of harvested shrimp of pond 7 and pond 10
were 7.56 cm and 8.99 cm, 5.10 g and 8.33 g, respectively. Furthermore, the survival rate, average biomass yield and average
condition factor of the shrimp harvested were 70% and 60%, 2.54 kg/m2 and 2.14 kg/m2, and 0.675 g/cm and 0.927 g/cm, respectively. Linear equations describing the relationship between body length and culture
time and cubic or power functions describing the relationship between body weight and body length were obtained based on evaluation
of the growth data of shrimps throughout the culture period. 相似文献