Ultrastructure of the bloodstream forms of the fish trypanosome Trypanosoma pseudobagri dogiel et achmerov, 1959

The ultrastructure of the bloodstream forms of Trypanosoma pseudobagri from its natural host, yellow catfish (Pseudobagrus fulvidraco), a freshwater fish, is described in the present work. The pellicle, consisting of a unit membrane with a superimposed surface coat, the structure and attachment of the flagellum and the subpellicular microtubules show the usual structural and organizational features. Cell organelles and cytoplasmic inclusions such as kinetoplast, mitochondria, nucleus and vacuoles, which occur in trypanosomidae, are observed and described in detail. The ultrastructure of T. pseudobagri has been compared with that of bloodstream forms of other species and culture forms of fish trypanosomes, and similarities and divergences are discussed. The Golgi-complex and endoplasmic reticulum could not be observed and need further investigation.

Redescription of Difflugia tuberspinifera Hu, Shen, Gu et Gong, 1997 (Protozoa : Rhizopoda : Arcellinida : Difflugiidae) from China

The freshwater testate amoeba Difflugia tuberspinifera Hu et al. 1997 collected from pond and lake in China, is investigated by light and scanning electron microscopy. This little known taxon is redescribed and its morphology, biometry and ecology are supplied. After carefully comparison with other six similar species including Difflugia bartosi Stepanek, D. corona Wallich, D. corona cashi Deflandre, D. corona tuberculata Vucetich, D. muriformis Gauthier-Lievre et Thomas and Netzelia tuberculata (Wallich) Netzal we believe that the sub-spherical to spherical shell, the mulberry-shaped appearance, the 7-10 apertural tooth-like structures, the short collar and the conical spines numbering from 4 to 8 at the upper equatorial region in D. tuberspinifera set it apart from other species. Besides, statistical analysis indicates that D. tuberspinifera is a size-monomorphic species characterized by a main-size class and a small size range and the shell height is significant correlated with other morphometric characters at p < 0.05 excepting the number of aperture tooth-like structures and the number of spines. Moreover, D. tuberspinifera inhabits not only lotic but also lentic environment.

卫星遥感监测ET方法及其在水管理方面的应用

概述了利用遥感技术监测流域蒸发(ET)用于流域水管理的研究,利用卫星遥感监测ET比传统地面监测ET方法具有更高的经济合理性和实用性;通过遥感监测的ET,不仅可以对农业用水效率、灌溉系统性能作出更符合实际的评价,还可服务于流域水资源管理和区域水资源利用规划。随着信息技术的快速发展,卫星遥感监测ET的方法在水管理方面的应用前景广阔,我国应加强对该技术的研究和应用。

Identification of herb Acanthopanax senticosus (Rupr. Et Maxim.) harms by capillary electrophoresis with electrochemical detection

In this paper, a rapid, high efficient, sensitive and inexpensive approach based on a combination of simple ultrasonic extract and capillary electrophoresis (CE) separation with electrochemical detection (ED), is described to identify herbs by comparing their CE-ED profiles (namely, CE-ED electropherograms). The proposed method takes advantage of ultrasmall sample volume, low consumption of organic solvent, simple sample pretreatment and easy cleanup procedure. It was applied to analyze the CE-ED profiles of stems of herb Acanthopanax senticosus (Rupr. Et Maxim.) Harms from different sources and different parts (roots, rhizomes, stems and leaves) of this herb. By comparing peak number, peak height and peak height ratio, we found that the CE-ED profiles showed big differences for the herbs from the different sources and the different parts of this herb. In addition, the distribution of bioactive compounds (isofraxidin, rutin and chlorogenic acid) in the different parts of this herb and their content variations affected by the source were studied with the CE-ED method. Based on their own unique CE-ED profiles, these herbs from the different sources and the different parts of this herb could be easily distinguished. Therefore, the proposed approach could be used as a rapid, high efficient and sensitive method for the identification of herbal medicines.

Investigation of the effect of branched structure on the performances of the copolymers synthesized from ethylene and alpha-olefin with rac-Et(Ind)(2)ZrCl2/MMAO catalyst system

The branched copolymers prepared from ethylene and alpha-olefins using rac-Et(Ind)(2)ZrCl2/MMAO catalyst system were studied. Both the absolute molecular weight ((M) over bar (W)) and the molecular size (radius of glyration, R-g) of the polymers eluting from gel permeation chromatography (GPC) columns were obtained simultaneously via a high temperature GPC coupled with a two-angle laser light scattering (TALLS) detector. The branched structures and performances of the copolymers display approximate molecular weight and molecular sizes were investigated. Wide angle X-ray diffraction analyses indicate that 16-carbon side branch could co-crystallize effectively with backbone chain at low alpha-olefin incorporation. The melt behaviors of the copolymers were studied by dynamic rheological measurements. Both branch length and comonomer content affect considerably the loss modulus, storage modulus and complex viscosity of the copolymers. The relationship between the dynamic-mechanical behavior and the comonomer content of the copolymers was also examined by dynamic-mechanical experiments.

Chromosomal localization and molecular marker development of the lipopolysaccharide and beta-1,3-glucan binding protein gene in the Zhikong scallop Chlamys farreri (Jones et Preston) (Pectinoida, Pectinidae)

Zhikong scallop Chlamys farreri(Jones et Preston) is an economically important species in China. Understanding its immune system would be of great help in controlling diseases. In the present study, an important immunity-related gene, the Lipopolysaccharide and Beta-1,3-glucan Binding Protein (LGBP) gene, was located on C. farreri chromosomes by mapping several lgbp-containing BAC clones through fluorescence in situ hybridization (FISH). Through the localization of various BAC clones, it was shown that only one locus of this gene existed in the genome of C. farreri, and that this was located on the long arm of a pair of homologous chromosomes. Molecular markers, consisting of eight single nucleotide polymorphism (SNPs) markers and one insertion-deletion (indel), were developed from the LGBP gene. Indel marker testing in an F1 family revealed slightly distorted segregation (p = 0.0472). These markers can be used to map the LGBP gene to the linkage map and assign the linkage group to the corresponding chromosome. Segregation distortion of the indel marker indicated genes with deleterious alleles might exist in the surrounding region of the LGBP gene.

A preliminary genetic map of Zhikong scallop (Chlamys farreri Jones et Preston 1904)

Zhikong scallop (Chlamys farreri Jones et Preston 1904) is one of the most important aquaculture species in China. The development of a genetic linkage map would provide a powerful tool for the genetic improvement of this species. Amplified fragment length polymorphism (AFLP) is a PCR-based technique that has proven to be powerful in genome fingerprinting and mapping, and population analysis. Genetic maps of C. farreri were constructed using AFLP markers and a full-sib family with 60 progeny. A total of 503 segregating AFLP markers were obtained, with 472 following the Mendelian segregation ratio of 1:1 and 31 markers showing significant (P< 0.05) segregation distortion. The male map contained 166 informative AFLP markers in 23 linkage groups covering 2468 cM. The average distance between markers was 14.9 cM. The female genetic map consisted of 198 markers in 25 linkage groups spanning 3130 cM with an average inter-marker spacing of 15.8 cM. DNA polymorphisms that segregated in a 3:1 ratio as well as the AFLP markers that were heterozygous in both parents were included to construct combined linkage genetic map. Five shared linkage groups, ranging from 61.1 to 162.5 cM, were identified between the male and female maps, covering 431 cM. Amplified fragment length polymorphism markers appeared to be evenly distributed within the linkage groups. Although preliminary, these maps provide a starting point for the mapping of the functional genes and quantitative trait loci in C. farreri.