Micromorphological characterization and label-free quantitation of small rubber particle protein in natural rubber latex

Commercial natural rubber is traditionally supplied by Hevea brasiliensis, but now there is a big energy problem because of the limited resource and increasing demand. Intensive study of key rubber-related substances is urgently needed for further research of in vitro biosynthesis of natural rubber. Natural rubber is biosynthesized on the surface of rubber particles. A membrane protein called small rubber particle protein (SRPP) is a key protein associated closely with rubber biosynthesis; however, SRPP in different plants has been only qualitatively studied, and there are no quantitative reports so far. In this work, H. brasiliensis was chosen as a model plant. The microscopic distribution of SRPP on the rubber particles during the washing process was investigated by transmission electron microscopy–immunogold labeling. A label-free surface plasmon resonance (SPR) immunosensor was developed to quantify SRPP in H. brasiliensis for the first time. The immunosensor was then used to rapidly detect and analyze SRPP in dandelions and prickly lettuce latex samples. The label-free SPR immunosensor can be a desirable tool for rapid quantitation of the membrane protein SRPP, with excellent assay efficiency, high sensitivity, and high specificity. The method lays the foundation for further study of the functional relationship between SRPP and natural rubber content.     

Facultative nitrogen fixation by legumes in the central Congo basin is downregulated during late successional stages

The contribution of the legume community to the nitrogen cycle during natural forest regeneration remains poorly understood. We systematically assessed the changes in abundance and nodulation status of all legumes, across taxa and plant types, in a forest succession gradient in the Equateur Province of the Democratic Republic of the Congo. Our results clearly show that symbiotic N₂ fixation is downregulated during late successional stages.     

Response of bird assemblages to windstorm and salvage logging — Insights from analyses of functional guild and indicator species

Natural disturbances, such as fire, windstorms and insect outbreaks, are important drivers of biodiversity in forest ecosystems, but at the same time cause large economic losses. Among the natural disturbances in Europe, windstorms cause the highest economic loss. After such storms, damaged forest stands are commonly salvage logged to restore economic value. However, such interventions could affect species assemblages of various taxonomic groups, including breeding birds. Despite these potential effects, investigations of the impacts of post-storm logging are largely lacking. We thus investigated assemblages of breeding birds in 21 logged and 21 unlogged windstorm-disturbed forest plots and 18 undisturbed, control forest plots using fixed-radius point-stop counts three, five and seven years after a windstorm within the Bavarian Forest National Park as part of the European Long-Term Ecosystem Research Network. We recorded 2100 bird individuals of 55 bird species. Bird assemblages were predominantly altered by the consequences of the windstorm and affected only to a minor degree by subsequent logging of storm-felled trees. Nevertheless, bird species richness was significantly reduced by post-storm logging within the first season. In general, the windstorm led to a shift in bird assemblage composition from typical forest species towards open- and shrub-land species. Assemblages of logged and unlogged disturbed plots consisted mainly of long-distance migrants and ground-foraging bird species, whereas assemblages of undisturbed control plots consisted of resident species that forage within vegetation. Both unlogged and logged storm-felled coniferous forest stands were inhabited by endangered or declining bird species, such as Water Pipit (Anthus spinoletta) on logged plots and Eurasian Redstart (Phoenicurus phoenicurus) on unlogged plots. Indicator species analyses suggested that species of unlogged storm disturbed plots depended on storm-created legacies, such as pits and snags, for foraging and nesting. Hence, we recommend reducing post-storm logging of these legacies to support species restricted to unlogged disturbed forest. To increase the diversity of breeding birds on the landscape scale, diverse logged and unlogged post-disturbance stands should be provided, which could be gained by a partial benign neglect strategy of storm disturbed forest stands.     

Diversity and Succession of Actinobacteria in the Forelands of the Tianshan Glacier,China

Actinobacteria are typically soil bacteria that have important roles in soil development and biogeochemical cycling. However, little is known about the occurrence or the succession of communities of Actinobacteria in new habitats. In this study, we investigated the diversity and succession of the actinobacterial communities that inhabited the forelands of the Tianshan Glacier (China), which ranged in successional age from 0 to 100 years since the forefield was deglaciated. Actinobacteria was one of the dominant phyla in the glacier foreland and included the orders Acidimicrobiales, Actinomycetales, Rubrobacteriales and Solirubrobacteriales. Actinomycetales was the dominant order, but its relative abundance decreased through the chronosequence. Acidimicrobiales and Solirubrobacteriales were more abundant in the late stages of succession than in the early ones. The abundance of Rubrobacteriales was only high at 74a. The dominant genera Nocardioides and Arthrobacter were widely distributed and were found in each stage of succession. With nonparametric and rarefaction estimated analyses, we found that the phylotype richness of Actinobacteria was significantly correlated with time (r = 0.886, p = 0.019). The succession of actinobacterial communities was divided into 3 stages: the early stage (6a), the intermediate stage (10a and 20a) and the late stage (60a, 74a, and 100a). Based on the canonical correspondence analysis, the actinobacterial communities were affected significantly by soil pH (r = ?0.834, p = 0.039) and somewhat by the C/N ratio (r = 0.783, p = 0.066). The nonmetric multidimensional scaling analysis showed that the effect of geographical isolation on the actinobacterial communities was greater than that of the soils in the development of the chronosequence.     

2007-2016年度国家自然科学基金医学科学领域"病毒 、病毒感染与宿主免疫"项目申请与资助情况分析

本文统计分析了2007-2016年度国家自然科学基金"病毒、病毒感染与宿主免疫(申请代码:H1904)"学科领域内的项目申请及资助情况,希望能对一线科研人员有所帮助.     

Phenological studies on the wing dimorphism of a semi-aquatic bug,Microvelia douglasi (Heteroptera: Veliidae)

Seasonal changes in the percentage of macropterous individuals in natural population of Microvelia douglasi in permanent habitats were investigated in Shimane, western part of Japan. Macropterous forms of 5th instar nymphs occurred most frequently from late June to early July. However, the seasonal appearance of macropterous adults differed between habitats and years. There were significant effects of density, temperature, photoperiod and food availability on the percentage of macropters under laboratory conditions. The percentage of macropterous forms generally increased with density, but the mode of the response was modified by temperature, photoperiod and food availability. When insects were reared under long day photperiod (16L8D) with abundant food (0.5–1.0 g/container/day), the percentage of macroptery varied most among the different density treatments at the intermediate temperature (24°C) and the difference was reduced at higher temperature (28° and 32°C). Effects of temperature were small under the short day photoperiod (12L12D). Under 12L12D photoperiod sensitivity of density responses were higher at 32°C and lower at 24°C than those under 15L8D photoperiod. When the insects were supplied with food every other day, the density response became obscure. Ecological significance of environmental responses in the wing morph determination was discussed in relation to the heterogeneous environment of water surface.     

当代森林动态的计算机模型述评

一、引言森林动态这一广义语,包括森林生态系统随时间的任何变化。要想经营好森林,使其为人类创造出最大的财富,必须深刻认识森林的动态规律。在过去的一个多世纪里,森林生态学家们对森林动态规律进行了广泛而深入的研究,现已形成各种动态学说。随着科学的发展以及森林经营水平的提高,人们逐渐用各种方     

Inconsistencies in standard approximations for selection coefficients at loci affecting a polygenic character

Inconsistencies exist in the standard expansions used to approximate selection coefficients for alleles at a locus underlying a quantitative character. Allelic (marginal) fitnesses obtained from expansions based on average excesses differ from allelic fitnesses obtained from expansions based on genotypic values. Similarly, the mean population fitness based on summing over either allelic or genotypic fitnesses usually differs mean population fitness obtained by averaging over the unrestricted phenotypic distribution. A consistent value of requires no variation in genotypic values. If, as suggested by Nagylaki (1984), expansions are corrected for the decrease in phenotypic variance resulting from conditioning on the presence of a particular allele or genotype, inconsistencies still exist. Unless W(z)[V _z p(z) + zp(z) + p(z)] dz = 0, where p(z) is the phenotypic probability density function, V _z the phenotypic variance, W( _z ) the fitness of phenotypic value z, the primes denote differentiation with respect to z, allelic fitnesses based on average effects differ from allelic fitnesses based on genotypic values. This condition must also be satisfied in order for either expansion to give a consistent , as first shown by Nagylaki. For arbitrary W(z), this is satisfied if and only if phenotypes are normally distributed.     

Interspecific hybridization betweenDaphnia hyalina,D. galeata,andD. cucullata and seasonal abundances of these species and their hybrids

The three cladoceran speciesDaphnia hyalina, D. galeata, andD. cucullata frequently coexist in the lakes of northern Germany. Although there are some problems in distinguishing them morphologically, they are easily determined by gelelectrophoresis: each species carries a different allele at the glutamate oxaloacetate transaminase (GOT) locus. Animals morphologically intermediate between two species are heterozygous for the alleles carried by the species they resemble. This pattern is in agreement with the findings at other loci, where also diagnostic alleles exist. These findings are most easily explained by interspecific hybridization between the three species. No evidence is found for backcrosses involving hybrids ofD. cucullata, whereas some backcrosses betweenD. hyalina, D. galeata, and their hybrids are found in some lakes. In four lakes the seasonal abundances of the three species and their hybrids are determined.