Comparison of the spectral sensitivity of juvenile red sea bream investigated by the physiological technique and by the behavioral technique

ABSTRACT:   The optomotor reaction of the red sea bream Pagrus major was utilized in order to measure its spectral sensitivity. The high spectral sensitivity of this species in twilight conditions was estimated to be from 480 to 560 nm, whereas it was observed to be also on longer wavelengths in the probable photopic vision. This result was compared with the sensitivity curve obtained by the physiological technique of the induction of electroretinogram. The form of both sensitivity curves did not show similar tendencies. It will be necessary to investigate the adjustment of a physiological phenomenon and a behavioral phenomenon concerned with various stimulus-reaction systems.     

Biology of the gametes of some teleost species

Our knowledge of the biology of fish gametes is still limited. Up to now research was short-term, aiming at solving practical questions connected with gamete storage and artificial insemination. More information on gamete biology is now available and has been summarized in this minireview.In vivo storage of gametes in the genital tract after ovulation or spermiation may be influenced by the osmotic environmentvia changes in the ionic composition of the companion fluid. There is great inter-individual variability in gamete survival bothin vivo andin vitro. Mechanisms involved in the initiation of trout sperm motility have been analysed; after dilution in water or NaCl solution (125 mM) at pH > 7, Ca⁺⁺ entry due to changes in membrane potential have been observed. The involvement of cAMP and protein phosphorylation has been reported. The morphological, physical and biochemical changes in eggs that have been studied after fertilization and the corticol reaction lead to a better understanding of the mechanisms of polyspermy blockage.     

Detection of monodon baculovirus and white spot syndrome virus in apparently healthy Penaeus monodon postlarvae from India by polymerase chain reaction

The simultaneous presence of monodon baculovirus (MBV) and white spot syndrome virus (WSSV) in apparently healthy postlarvae of Penaeus monodon from different hatcheries in India was studied by nested polymerase chain reaction (PCR). MBV could be detected in 54% of the samples. However, only 15% of samples were positive by non-nested reaction. WSSV could be detected in 75% of samples, 19% being positive by non-nested reaction. The results show simultaneous presence of WSSV and MBV in many samples at various degrees of infection. Only 14% of the samples analysed were negative for both viruses.     

木质素磺酸钠合成水性环氧固化剂的研究

通过曼尼希反应,用木质素磺酸钠改性脂肪族多胺,合成了一种新型的水性环氧固化剂,红外光谱表征了目标产物的结构.通过测试固化体系的邵氏硬度、拉剪强度、正拉黏接强度和耐热性等,研究了NaOH水溶液用量、原料的配比、反应温度、反应时间、固化剂与环氧树脂的配比等对固化体系性能的影响.结果表明:在不使用NaOH水溶液情况下,木质素...     

In vitro metabolism in Sprague-Dawley rat liver microsomes of forsythoside A in different compositions of Shuang-Huang-Lian

Shuang–Huang–Lian (SHL), a traditional Chinese formula containing Lonicerae japonicae flos (LJF), Scutellariae radix (SR) and Forsythiae fructus (FF), is commonly used to treat acute upper respiratory tract infection, acute bronchitis and light pneumonia. Forsythoside A is one of the main active ingredients in Forsythiae fructus, a key herb in SHL. In the present study, effects of different compositions in SHL on the in vitro metabolism in Sprague–Dawley rat liver microsomes of forsythoside A were investigated. The observations from Sprague–Dawley rat liver microsomes in the presence of β-NADPH or UDPGA that forsythoside A may be the substrates of CYP3A4, CYP2C9, CYP1A2, UGT1A6, UGT1A3, UGT1A1 and UGT1A9; Chlorogenic acid may be the substrates of CYP3A4, CYP2C9, CYP1A2, CYP2C19, UGT1A6, UGT1A3 and UGT1A1; Baicalin may be the substrates of CYP3A4, CYP2C19, CYP1A2, UGT1A9, UGT1A1 and UGT1A3; Baicalein may be the substrates of CYP3A4, CYP2E1 and UGT1A6. It was also found that the residue of forsythoside A in SHL, FF + LJF and FF + SR was greatly increased compared with that in FF in Sprague–Dawley rat liver microsomes in the presence of β-NADPH or UDPGA, which indicated that the metabolism of forsythoside A in SHL may be influenced by chlorogenic acid in LJF acting on the CYP3A4, CYP2C9, CYP1A2, UGT1A6, UGT1A3 and UGT1A1; baicalin in SR acting on the CYP3A4, CYP1A2, UGT1A9, UGT1A1 and UGT1A3; baicalein acting on the CYP3A4 and UGT1A6 respectively.     

智能电子称重与土壤温湿度检测系统的研究

为解决在环境植物保护、农业生产发展及工业生产进步过程中电子秤存在的操作地点受限、操作功能单一及操作结果无法实时处理等问题,研究设计了一套智能电子称重与土壤温湿度检测系统。该系统电子称量精度高(可达0.001g),通过GPS对野外操作地点和时间实时标注记录,采用土壤温度传感器和水分传感器实时检测土壤温湿度,将操作结果存储于中央处理器内,同时利用GPRS对实时操作获取的数据信息无线传输到终端计算机。试验证明,系统实现了野外取样实时称量、土壤温湿度检测、环境信息记录和操作结果的实时处理。     

Selection of sites for preliminary maize yield trials in the rainforest zone of South-Western Nigeria

Summary Grain-yield data obtained from 49 varieties of maize (Zea mays L.), grown at each of five sites for two years, were analyzed with the objective of identifying two or three sites where mean performance adequately predicted the mean performance of all five sites combined. Regression of overall varietal mean on site or site-combination means was done and the predictive potential of a site or combination of sites was judged by four criteria: (i) r²0.9, (ii) b1.0, (iii) high yield (i.e., yield greater than or equal to overall mean yield) and (iv) consistent yield (i.e., yield did not fall below the mean yield by more than 10%). In addition, a trial differentiation index, D, was used to compare the site combinations selected on the basis of the above criteria with the differentiation potential of all five sites combined. None of the five individual sites and the ten two-site combinations satisfactorily predicted overall mean yield. However, five three-sites combinations had values of D similar to that of all the five sites. Rank-correlation coefficients of the three-site combinations with all five sites ranged from 0.90 to 0.79. It was concluded that certain three-site combinations could be satisfactorily used for preliminary maize yield trials in the rainforest ecological zone of S.W. Nigeria.     

Screening sweet potato for source potentials

Summary Screening sweet potato, Ipomoea batatas, L., for source potentials is more difficult than for sink capacities. Twenty clones were grafted to four tester varieties to screen them for source potentials in relation to sink capacities which are interdependent. Source potential of a clone was measured by its average scion effect when grafted on the four tester varieties. There were significant differences in source potentials among the twenty clones. Seven clones were selected for having high source potentials. Clone TIS 2498 was the best. Degrees of response of source to sink were estimated using the regression method for twenty clones showed significant differences and ranged from b–0.45 to b=2.06. Source potential showed significant relationship (r=0.62^**) with response of source to sink. Implication of this approach to sweet potato breeding is discussed.