The Silkworm Knowledgebase (SilkDB) is a webbased repository for the curation, integration and study of silkworm genetic and genomic data. With the recent accomplishment of a 6X draft genome sequence of the domestic silkworm (Bombyx mori), SilkDB provides an integrated representation of the large-scale, genome-wide sequence assembly, cDNAs, clusters of expressed sequence tags (ESTs), transposable elements (TEs), mutants, single nucleotide polymorphisms (SNPs) and functional annotations of genes with assignments to InterPro domains and Gene Ontology (GO) terms. SilkDB also hosts a set of ESTs from Bombyx mandarina, a wild progenitor of B.mori, and a collection of genes from other Lepidoptera.Comparative analysis results between the domestic and wild silkworm, between B.mori and other Lepidoptera, and between B.mori and the two sequenced insects, fruitfly and mosquito, are displayed by using B.mori genome sequence as a reference framework. Designed as a basic platform, SilkDB strives to provide a comprehensive knowledgebase about the silkworm and present the silkworm genome and related information in systematic and graphical ways for the convenience of in-depth comparative studies. SilkDB is publicly accessible at http://silkworm.genomics.org.cn.

The relaxation phenomena are critical aspects of fruit rheological properties. Little detailed information is available on the non-homogeneous and anisotropic relaxation properties of fruits. The objective of this study was to determine the effects of specimen orientation and location with the pear on the equilibrium modulus, the decay modulus, time of relaxation, and specific viscosity in the relaxation model. The stress relaxation tests were performed on Dangshan pear using the Instron universal testing machine. The decay modulus, the equilibrium modulus, time of relaxation, and specific viscosity in the relaxation model are significantly influenced by specimen orientation, latitude, and depth. The longitude of the specimen and initial deformation are not significant.

An experimental system was set up to generate the impact force, measure the response signal and analyse the frequency spectrum for physical property detection of biological products. The pear dynamic resonance frequencies were obtained based on analysis of the dynamically measured frequency response of an excited pear with changes in the excitation points, the detection points, the impact intensity and the excitation material, and under different pear firmness and mass conditions. As a result of the analysis, it was found that the dominant frequency was significantly affected by the pear firmness and mass. The excitation point, the detection point, the excitation intensity and the impacting material did not significantly affect the dominant frequency. The dominant frequency increased with increasing pear firmness and decreased with increasing pear mass. A good relationship was obtained between the dominant frequency and the pear firmness or the pear mass, and the firmness index regressed on the Magness-Taylor firmness also showed a good relationship.

We describe a genetic variation map for the chicken genome containing 2.8 million single-nucleotide polymorphisms (SNPs). This map is based on a comparison of the sequences of three domestic chicken breeds (a broiler, a layer and a Chinese silkie) with that of their wild ancestor, red jungle fowl. Subsequent experiments indicate that at least 90% of the variant sites are true SNPs, and at least 70% are common SNPs that segregate in many domestic breeds. Mean nucleotide diversity is about five SNPs per kilobase for almost every possible comparison between red jungle fowl and domestic lines, between two different domestic lines, and within domestic lines-in contrast to the notion that domestic animals are highly inbred relative to their wild ancestors. In fact, most of the SNPs originated before domestication, and there is little evidence of selective sweeps for adaptive alleles on length scales greater than 100 kilobases.