再生稻褐飞虱为害损失测定和防治指标的研究

在福建,褐飞虱是再生稻的重要害虫,中进行了再生稻褐飞虱为害损失的测定,并对褐飞虱为害再生稻造成的产量损失结构进行了通径分析。根据虫量和产量损失的关系,结合现行稻谷价格,产量水平,防治费用等因素。确定允许为害损失率,同时建立了再生稻褐飞虱防治指标模型,按照防治指标模型,制定出不同产量水平的防治指标。     

人源溶菌酶结构与功能的研究进展

人溶菌酶是一类人体内天然存在的能够溶解细菌细胞壁的碱性蛋白的总称。其作用特征是能够裂解肽聚糖中的N-乙酰氨基葡萄糖与N-乙酰氨基甲酸之间的β-(1,4)-糖苷键。人溶菌酶具有抗菌、抗炎、抗病毒和增强免疫力等多种特性,因此在国内外市场上应用广泛。本文就人溶菌酶的结构特点、表达部位、功能表达以及应用情况进行综述。     

Ecological compensation of the impacts of a road. Preliminary method for the A50 road link (Eindhoven-Oss, The Netherlands)

After years of efforts to avoid or reduce the impact of infrastructure projects on nature, the principle of ecological compensation has been incorporated in Dutch governmental policy. Ecological compensation aims to recover those ecological functions and natural values that still remain affected after maximum effort has been made to reduce the impact of the intervention (mitigation). The accepted aim of current policy is thus no-net-loss of area and quality by means of mitigative and compensatory measures. As part of the planning process for construction of a stretch of road in The Netherlands, viz., the A50 road link in the province of North Brabant, a Nature Compensation Plan (NCP) was required to be drawn up. This work has recently been completed by the Regional Directorate of Public Works and Water Management, the initiator of the intervention. The NCP, initially presented as a Draft Plan, was drawn up by the Regional Directorate using a preliminary method designed by the Centre of Environmental Science of Leiden University for deriving compensatory measures. After an opportunity for public comment, the Draft Plan was revised to form a Final NCP. This article describes, firstly, the preliminary method for deriving ecological compensatory measures. The method starts by quantifying the effects of habitat loss, habitat disturbance (by changes in noise emissions, in the water table and in outdoor recreational patterns), barrier action and fauna casualties. Following mitigation of impacts on nature, compensation for non-mitigable effects focuses successively on area size, derived from the impacts on breeding birds, and on area quality, derived from the habitat requirements of the vegetation and fauna groups affected by the road. Guidelines for identifying appropriate locations for compensation are also formulated. Secondly, the compensation method is applied to calculate the mitigative and compensatory measures for the A50 trajectory between Eindhoven and Oss. Thirdly, two comparisons are made: the Draft NCP is compared with the results of the preliminary method, and the Draft and the Final NCP are compared with one another in order to identify the role of the interest groups that played a major role in commenting on the Draft Plan. Finally, realization of the compensatory measures and development of the preliminary method itself are discussed. On the basis of the experience with the A50 case study, a more robust compensation method for road projects is to be developed.     

日粮水平对鲇鱼日总代谢,特殊动力作用和活动代谢的影响

在２５℃不同日粮水平（饥饿─４％体重／ｄ）条件下,采用封闭式呼吸仪测定了３１尾鲇鱼（体重７２．９─１３３．３ｇ）的日总代谢率,然后,将鱼限制在呼吸室中的限动笼内测定了其中２０尾鲇鱼的静止日总代谢率,并计算出了鲇鱼的特殊动力作用（ＳＤＡ）和活动代谢率。日总代谢率和活动代谢率都随日粮水平的升高呈“Ｖ”形变化,分别在约１％和２％体重／ｄ的日粮水平时最低,ＳＤＡ的能量支出占摄入能量的２２．１４％。     

乳链菌肽的分离纯化和部分生物学性质

用乳酸链球菌ＳＭ５２６进行乳链菌肽的发酵生产,产量为４０～５０ｍｇ／ｌ．经中空纤维超滤器超滤,非极性大孔吸附树脂ＸＡＤ－２层析,ＣＭ－ＳｅｐｈａｄｅｘＣ－２５层析和ＳｅｐｈａｄｅｘＧ－５０层析纯化了该肽。ＳＤＳ－ＰＡＧＥ表明达均一,ＲＰ－ＨＰＬＣ表明其纯度不低于９５％。ＳＤＳ－ＰＡＧＥ测其Ｍｒ约为３６００,用ＩＥＦ测其等电点为９．５．酸性条件下稳定且抗热;对胰蛋白酶、胃蛋白酶和木瓜蛋白酶不敏感,但对α－胰凝乳酶和蛋白酶Ｋ敏感。乳链菌肽对多种革兰氏阳性菌有强烈的抑制作用;以枯草杆菌和金黄色葡萄球菌为指示菌,其作用方式是杀菌。     

Antithrombotic effect of topically applied 3-Oxa-Methano-prostaglandin I1 in the microcirculation and antiplatelet functions of its active form

The antithrombotic effect of topical application of the 3-oxamethano-prostaglandin (PG) I₁ analog, SM-10902 in the microcirculation and in vitro antiplatelet functions of its active form SM-10906 were estimated in comparison with PGI₂ and PGE₁. In rat platelets, SM-10906 evoked accumulation of intracellular cyclic adenosine 3′,5′-monophosphate, and exhibited antiaggregatory and disaggregatory activities, which were all enhanced by the phosphodiesterase inhibitor theophylline. Additionally, SM-10906 was shown to inhibit platelet adhesion to collagen in human platelet-rich plasma. PGI₂ and PGE₁ also showed in vitro antiplatelet effects in the order of PGI₂ > SM-10906 ≥ PGE₁. SM-10902 exhibited a dose-dependent antithrombotic effect in the guinea pig mesenteric arteriole by a topical application, and this activity might be exerted by the antiplatelet functions of SM-10906. Although SM-10906, PGI₂ and PGE₁ also showed the antithrombotic effects, SM-10902 was the most potent. In conclusion, the present studies indicate that an external topical preparation of SM-10902 may be useful for the therapy of peripheral circulatory insufficiency.     

Analysis of the genetic effects for several traits in oil palm (Elaeis guineensis Jacq.) populations. I. Population means

An oil palm experiment was set up in the Ivory Coast to compare the effects of crossing and selfing within two origins, Deli and La Mé, on the mean and the variability of Deli x Mé between-origin hybrids. The originality of the experiment lay in the crossing plan, which provided access to genetic parameters related to additivity, dominance and different components of epistasis. This first part covers the analysis of the components of the mean. The parents used were obtained from four palms, two from each origin. Those of La Mé origin were half-sibs. The common parent came from a wild stand in the Ivory Coast. Those of Deli origin were from two different populations bred in Southeast Asia for several generations from a narrow genetic base. These four parents gave rise to nine Deli x La Mé hybrid populations with double-cousintype links. The additive component is more important within the Deli origin than within the La Mé origin. This may be explained by the large genetic divergence between the two Deli parent palms. On the other hand, the additive^* additive epistasis is more substantial within the La Mé origin, probably because of inbreeding. The discussion concentrates on how this information should be used when choosing parents to be crossed and tested and to produce improved populations. The crossing plan proposed can be of general use and is suitable for other species in a reciprocal recurrent selection programme.     

Seasonal variation in hydrochloric acid, malic acid, and calciumions secreted by the trichomes of chickpea (Cicer arietinum)

A novel experimental set-up and method of recording of electrical potential differences in plants have been developed which enable continuous, 8-channel monitoring of electrical activity over extended periods of time using inserted, extracellular electrodes. The investigations were carried out on 21- to 23-day-old Helianthus annuus plants, and spontaneously-generated action potentials were recorded during monitoring sessions lasting for 3 days and nights. Characteristics of these spontaneous action potentials were elaborated, adopting as parameters their typical form, amplitude, duration, velocity, direction, and distance of propagation and frequency of occurrence in morphologically different parts of the plant, Variability, similarities, and interdependence of the above parameters in individual plants and in a group of 15 plants were determined. A hypothesis concerning propagation of action potentials in plants along specific impulse-propagating 'columns' is discussed. The frequency of generated impulses is highest at night and lowest in the day and also displays an apparent 24-h rhythm. Presumably this mechanism is under both endogenous and exogenous control and may be partly dependent on a biological clock.     

Synergism of thidiazuron and benzyladenine in axillary shoot formation depends on sequence of application in Miscanthus X ogiformis ‘Giganteus’

Shoots of Miscanthus X ogiformis Honda Giganteus transferred from medium with benzyladenine (BA) to thidiazuron (TDZ) formed significantly more axillary shoots than shoots grown continuously on either medium, or transferred from TDZ to BA. Shoot formation on axillary shoots transferred from BA-containing media to media with kinetin or isopentenyladenine (2iP) or transferred from media with TDZ, kinetin or 2iP to media with BA, corresponded to the number of shoots formed in the previous subculture. Shoot formation on shoots transferred from medium containing BA to media containing combinations of BA and/or TDZ increased with increasing concentrations of TDZ in the first subculture, whereas shoot formation in the second and third subculture depended on the BA concentration. When shoots were transferred from media with BA to media with TDZ, the time for shoot formation, as well as shoot size, indicate that the combined effect of BA and TDZ is expressed only during the early phase of the subculture. The results suggest that adenine- and phenylurea-type cytokinins have a common binding site in the plant cell, and a model is proposed.Abbreviations BA 6-benzyladenine - CBP cytokinin-binding protein - 2iP isopentenyladenine - KIN kinetin - MS Murashige & Skoog - TDZ thidiazuron     

Evidence for selective effects of vanadium on adipose cell metabolism involving actions on cAMP-dependent protein kinase

The insulin-like effects of vanadiumin vivo are likely to be achieved at micromolar concentrations. Demonstrated effects of vanadium on adipose tissue of streptozotocin-diabetic rats include inhibition of basal and stimulated rates of lipolysis and effects on fat cell protein phosphorylation. The studies described below examined the effects of vanadium (to a maximum concentration of 0.5 mM) on adipose cells or tissuein vitro. Vanadium, added as a vanadyl-albumin complex or as sodium orthovanadate, produced a marked (greater than 50%) inhibition of isoproterenol-stimulated lipolysis. Inhibition of lipolysis equivalent to that seen with insulin, was achieved with 100 M vanadium. In contrast, no insulin-like stimulation ofde novo fatty acid biosynthesis was observed with vanadium below 0.5 mM. Surprisingly, the antilipolytic effects of vanadium persisted in the presence of cilostamide, an inhibitor of the insulin-sensitive isoform of cyclic nucleotide phosphodiesterase. Studies with purified preparations of the catalytic subunit of cyclic AMP-dependent protein kinase revealed dose-dependent inhibition with vanadyl-glutathione (to a maximum of 40% inhibition). Equivalent inhibition of cyclic AMP-dependent phosphorylation of Kemptide (50%) was observed upon incubation of freshly-prepared fat-pad supernatant fractions with vanadyl-glutathione. These results suggest that effects of low concentrations of vanadium may be mediated, at least in part, by actions on the catalytic subunit of cyclic AMP-dependent protein kinase.