Allotetraploid hybrids produced by protoplast fusion for seedless triploid <Emphasis Type="BoldItalic">Citrus</Emphasis> breeding

In connection with crop improvement strategies for marginal regions it has been proposed to increase the outcrossing rate in barley which would presuppose high and persistent pollen viability to ensure successful cross fertilisation. The present study was designed to investigate the viability of mature pollen from extruded and non-extruded anthers of cultivated and wild barley (Hordeum vulgare ssp vulgare and ssp spontaneum, respectively) in comparison with the closely related but obligatory outcrossing species H. bulbosum. Pollen viability (PV) was assessed employing the p-phenylenediamine-peroxidase-test on pollen derived from spikes or anthers immediately after collection and after treatment at 20, 30 and 40 ^∘C for 1, 2, 4, 8 and 16 h. The latter treatment was interposed after 8 h by a 10 h period of darkness at 12 ^∘C and thus called 26 h treatment, consecutively. Initial PV was high with 98% across all genotypes and even at 40 ^∘C did not fall below 80% after 8 h. After the 26 h treatment, PV of two H. vulgare genotypes originating from semi-arid regions and of H. bulbosum fell below 60% while the other genotypes retained a PV of > 80%. Viability of pollen of extruded anthers in H. vulgare ssp. spontaneum was on average slightly but significantly lower than PV of non-extruded anthers but still remained above 90%, even after the 26 h treatment at 40 ^∘C. Pollen viability of the outcrossing species H. bulbosum ranged on a very similar level as PV of H. vulgare. Results indicate that pollen of H. vulgare retains a sufficiently high level of viability to ensure successful cross-fertilisation over a period of at least 26 h even at high temperatures of up to 40 ^∘C.     

Tyrosinase inhibitory activity of proanthocyanidins from woody plants

Flavanol values, molecular weight distributions, polyphenolic patterns, and tyrosinase inhibitions of proanthocyanidins (PACs) from karamatsu (Larix sp.) bark, acacia Morishima (Acacia mearnsii) bark, and commercial quebracho (Schinopsis lorentzii) extracts were examined to investigate the relation between the structures of PACs from woody plants and tyrosinase inhibitory activities. Aqueous acetone (70%) extracts of acacia showed high flavanol contents and strong tyrosinase inhibition. On the other hand, the quebracho extracts inhibited tyrosinase activity slightly despite its high flavanol content. Phenyl nucleus analysis by the nucleus exchange reaction provided information that karamatsu, quebracho, and acacia extracts consist of procyanidin, profisetinidin, and prorobinetinidin, respectively. The relation between the phenolic hydroxylation pattern and tyrosinase inhibition suggested that the PACs with a 5,7-dihydroxyphenyl structure in the A-ring and a 3,4,5-trihydroxyphenyl structure in the B-ring have potent tyrosinase inhibitory activity.Part of this paper was presented at the 49th Annual Meeting of the Japan Wood Research Society, Tokyo, April 1999     

Immunostimulatory effects of fermented vegetable product on the non-specific immunity of Japanese flounder <Emphasis Type="Italic">Paralichthys olivaceus</Emphasis>

The stimulatory effect of fermented vegetable product (FVP) upon the phagocytic and superoxide generation of leukocytes was studied in the Japanese flounder Paralichthys olivaceus. The phagocytic activity of casein-induced, intraperitoneal leukocytes was investigated and quantified, that is the activity significantly increased (P<0.05 or <0.01) by the addition of FVP beyond 3 mg/kg body weight. Further analysis investigated the effect of FVP on superoxide generation in leukocytes. Established in vitro cytochrome c reduction assay was used to measure superoxide generation; reduced levels of FVP in assay samples had a profound effect on superoxide generation. FVP was also incorporated in commercial diets and fed to Japanese flounder for 4 weeks. The phagocytic activities and superoxide generation of peritoneal induced leukocytes were significantly higher (P<0.05, <0.01) in fish fed the FVP supplemented diet than fish fed the control diet. FVP feeding in fish had a significantly higher (P<0.05) activity of lysozyme than in the control fish.     

Characterization of strength properties of branchwood and stemwood of some tropical hardwood species

The mechanical strength properties of the branchwood of Aningeria robusta and Terminalia ivorensis with diameters ranging from 10 to 25 cm were examined to determine the suitability of branchwood as raw material for downstream processing. The study precisely assessed the static bending strengths, compression strengths and shear strengths parallel to the grain of the branchwood and stemwood of T. ivorensis and A. robusta. It was observed that under static bending, the overall (sapwood and heartwood combined) modulus of rupture and modulus of elasticity of the branchwood of A. robusta and T. ivorensis were lower than that of their corresponding stemwood. The results further show that the overall compression and shear strengths parallel to the grain of the branchwood of A. robusta and T. ivorensis were higher than that of their corresponding stemwood. Under static bending, compression parallel to the grain, and shear parallel to the grain, the experimental results indicate that the sapwood of the branchwood from both T. ivorensis and A. robusta had lower strength values than that of their corresponding heartwood. Similar results were recorded for the stemwood of T. ivorensis where the heartwood had higher strength values than the sapwood. However, in the case of the stemwood of A. robusta, the sapwood had higher strength values than the corresponding heartwood.     

Models of microfibril elastic modulus parallel to the cell axis

Based on different physical assumptions six possible models are developed or adopted concerning the component of the elastic modulus of a single microfibril, i.e. the elastic modulus that is parallel to cell axis about which the microfibril is coiled like a loose or lazy spring. A thorough evaluation regarding the disparities between the rigorous and simplified models is presented. The simulation demonstrates that the simplified models differ considerably from the rigorous one especially in the small microfibril angle range. This would explain the poor estimations of cell wall stiffness at low microfibril angles as seen in previous modelling studies.An erratum to this article can be found at     

聚乙二醇对烟草种子活力及幼苗保护酶活性的影响

 以烟草种子为材料,用不同浓度的聚乙二醇（PEG）浸种不同时间,测定了浸种后种子萌发过程中和萌发后幼苗中某些生理生化指标及保护酶活性的变化。结果表明,PEG浸种能显著提高种子发芽率和幼苗活力指数,增强萌发种子的呼吸强度和淀粉酶活性,以20% PEG-6000浸种48 h效果最好。不同活力水平的种子经20%PEG处理后,幼苗活力指数明显提高,叶片超氧物歧化酶（SOD）、过氧化氢酶（CAT）和过氧化物酶（POD）等保护酶活性升高,膜脂过氧化产物丙二醛（MDA）和超氧阴离子（O₂^-）含量及电解质外渗率显著低于对照。研究还发现,PEG处理能提高种子在低温下的萌发率,增强幼苗抗冷性。     

Interactive and dynamic graphics in statistical consulting

Twelve years ago, Unwin wrote an article titled “How Interactive Graphics Will Revolutionize Statistical Practice.” Well, has it? I think it has. At that time Data Desk was the prime commercially available package for interactive statistical graphics. Since then interactive and dynamic graphics have become increasingly available in many statistical and visualization packages, and some are even available, or easy to set up, in general spreadsheets like Excel. Examples of using interactive and dynamic graphics in ways that are useful in statistical consulting will be given. We’ll gain insight into some old data and into some new data, including microarray data.     

Dimensional instability of cement bonded particleboard: contributions to its occurrence

An intensive programme of research has been carried out to understand the dimensional instability of cement bonded particleboard (CBPB) and establish methods of improving its stability. The quantitative appraisal and qualitative interpretation of the instability were through investigations on CBPB, wood chips and cement paste. Aspects studied included the sorption of all three materials, SEM, image analysis and carbonation of CBPB, and stabilisation of CBPB using various pre-treatments. As part of this programme, this paper discusses the occurrence of instability of CBPB. It was found that the movement of CBPB was attributable to the contributions of its components, the distribution of wood chips and cement paste, carbonation, and residual stresses in CBPB. The behaviour of wood chips and cement paste dominated the movement of CBPB, with the effect of wood chips being greater than that of cement paste; but the behaviour of the cement paste dominated the behaviour of CBPB over a prolonged exposure. Carbonation resulted in a significantly irreversible increase in mass and decrease in dimension of CBPB under both constant and changing RH. The distribution of wood chips in CBPB determined that the change between length and width was almost identical due to a random distribution of wood chips on the horizontal surface (about 45° to the longitudinal edge), and the thickness change was much higher than length change due to wood chips almost lying flat (about 11° to the horizontal). The generation and distribution of stresses had a significant influence on the behaviour of CBPB.