Short communication: Amino acids antagonistic to the amino acids inhibitory for growth rate of mixed ruminal bacteria

Antagonism of some amino acids (AA) to the inhibitory effects of other AA (Ile, Phe, and Thr) on the growth rate of mixed ruminal bacteria was investigated. In vitro growth rate of the mixed ruminal bacteria was inhibited when the 3 inhibitory AA (1 mM each) were each added to individual control treatments in which an ammonium salt was included as a sole N source. The inhibitory effect caused by Ile was relieved by addition of Leu or Val (equimolar to Ile), and no significant inhibition was shown when both Leu and Val were added together with Ile. The growth inhibition caused by Phe was also alleviated by supplementing with Trp, and was completely negated by adding Tyr. The inhibitory effect of Thr, on the other hand, was not affected by addition of Lys or Met (which are synthesized using a common pathway with Thr), but was mitigated by supplementation with Glu, Ser, Val, Ala, or Gln. Among the antagonistic AA, Leu, Val, Trp, Tyr, and Glu were indispensable for the maximum growth rate of the ruminal bacteria under the experimental condition of supplementation of amino-N, the removal of which from a mixture of 20 protein AA caused the growth rate to decline. Removals of Ile along with Leu or Val or both, of Phe along with Trp or Tyr, and of Thr along with Glu recovered the promotion of bacterial growth rate. It was concluded that inhibitions of the bacterial growth rate caused by Ile, Phe, or Thr could be antagonized by some other AA (Leu, Val, Tyr, Trp, or Glu), and the role of these latter AA as relievers of the inhibitory effects could explain why they are indispensable for maximum growth rate of ruminal bacteria.     

叶面喷施有机硒对大豆不同器官吸收Cd、Pb的影响

通过对大豆进行叶面喷施硒蛋氨酸的盆栽试验,发现能明显提高大豆籽粒硒水平,籽粒富集Se的能力约是对照的6倍,不同器官富集Se的规律为:叶粒茎壳,而其产量没有发生明显变化。大豆叶片吸收Cd,Pb的能力最强,其中叶片Cd含量为0.30~0.90 mg/kg,Pb含量为1.0~1.9 mg/kg,叶片Pb含量是籽粒的42~98倍。大豆植株里的Se对籽粒、壳、叶、茎等各器官吸收Cd、Pb均表现出拮抗作用,对Cd的拮抗作用较强,对Pb的拮抗作用较弱。     

Study on Anti-ship Missile Saturation Attack Model

Based on the analysis for the interception process of ship-to-air missile system to the anti-ship missile stream, the antagonism of ship-to-air missile and anti-ship missile stream was modeled by Monte Carlo method. This model containing the probability of acquiring anti-ship missile, threat estimation, firepower distribution, interception, effectiveness evaluation and firepower turning, can dynamically simulate the antagonism process of anti-ship missile attack stream and anti-air missile weapon system. The anti-ship missile's saturation attack stream for different ship-to-air missile systems can be calculated quantitatively. The simulated results reveal the relations among the anti-ship missile saturation attack and the attack intensity of anti-ship missile, interception mode and the main parameters of anti-air missile weapon system. It provides a theoretical basis for the effective operation of anti-ship missile.