A Map-Based Service Supporting Different Types of Geographic Knowledge for the Public

The internet enables the rapid and easy creation, storage, and transfer of knowledge; however, services that transfer geographic knowledge and facilitate the public understanding of geographic knowledge are still underdeveloped to date. Existing online maps (or atlases) can support limited types of geographic knowledge. In this study, we propose a framework for map-based services to represent and transfer different types of geographic knowledge to the public. A map-based service provides tools to ensure the effective transfer of geographic knowledge. We discuss the types of geographic knowledge that should be represented and transferred to the public, and we propose guidelines and a method to represent various types of knowledge through a map-based service. To facilitate the effective transfer of geographic knowledge, tools such as auxiliary background knowledge and auxiliary map-reading tools are provided through interactions with maps. An experiment conducted to illustrate our idea and to evaluate the usefulness of the map-based service is described; the results demonstrate that the map-based service is useful for transferring different types of geographic knowledge.     

Genome-wide comparative analysis of the codon usage patterns in plants

Codon usage analysis has been a classical area of study for decades and is important for evolution, mRNA translation, and new gene discovery. Recently, genome sequencing has made it possible to perform studies of the entire genome in plant kingdoms. The base composition of the coding sequence, codon usage pattern, codon pairs, and related indicators of relative synonymous codon usage (RSCU), including the Fop, Nc, RSCU, CAI and GC contents, were analyzed. We found that the GC content of single-celled algae is the highest, whereas dicotyledons are the lowest. Moreover, the base composition of plants is similar within the same family. In addition, the GC content of the second base of the codon is lower than the first and third base. In conclusion, the codon usage characteristics are opposite in Gramineae, single-celled algae, fern and dicotyledon, moss, and Pinaceae. Furthermore, the degree of codon usage bias is decreasing with evolution. Therefore, we hypothesize that the lower the plants, the more that they must optimize codons and that higher plants no longer need to optimize codons.     

Tailor-made approach for selective isolation and elution of low-density lipoproteins by immunoaffinity sorbent on silica

Immunoaffinity procedure was developed for isolation of low density lipoprotein (LDL) from biological samples by using silica-derived immunoaffinity sorbent. Sorbent was prepared by immobilization of monoclonal anti-apoB-100 antibody onto macroporous silica particles, using carefully optimized binding chemistry. Binding capacity of the sorbent towards LDL was determined by batch extraction experiments with solutions of isolated LDL in phosphate-buffered saline, and found to be 8 mg LDL/g. The bound LDL fraction was readily released from the sorbent by elution with ammonia at pH 11.2. The total time needed for isolation procedure was less than 1 h, with LDL recoveries being essentially quantitative for samples containing less than 0.3 mg LDL/mL. With higher concentrations, recoveries were less favorable, most probably due to irreversible adsorption caused by LDL aggreggation. However, reusability studies with isolated LDL at concentration 0.2 mg/mL indicate that the developed immunoaffinity material may be used for multiple binding-release cycles, with minor losses in binding capacity. Finally, the sorbent was successfully applied to isolation of LDL from diluted plasma. Apart from its practical implications for LDL isolation, this study provides crucial insights into issues associated with LDL-sorbent interactions, and may be useful in future efforts directed to development of lipoprotein isolation approaches.     

基于线粒体细胞色素b基因分析海南岛褐家鼠种群遗传多样性

褐家鼠(Rattus norvegicus)是海南岛的主要害鼠之一,海南岛是我国南方海上的重要交通口岸,但关于海南岛褐家鼠的种群遗传多样性以及和邻近地区褐家鼠种群间的基因交流情况还缺乏了解。本研究测序分析了来自海南岛、广东、越南等地91只褐家鼠的细胞色素b基因,分析了不同种群中的Cyt b单倍型,种群间的遗传分化程度(F_(st)),构建了全世界60个褐家鼠的Cyt b单倍型之间的系统进化关系。结果发现,海南岛琼中/澄迈和崖城的褐家鼠种群没有共享的Cyt b单倍型,种群间出现了明显的遗传分化(F_(st)=0.453),但这两个群体分别与广东和菲律宾/越南的褐家鼠分享共同的单倍型,表明海南岛褐家鼠与广东和菲律宾/越南褐家鼠近代存在着基因交流。系统进化分析结果表明,多数海南岛和广东褐家鼠的Cyt b单倍型来自共同的单倍型组CⅢ和CⅦ,说明海南岛和广东省的褐家鼠可能由一个或多个共同的祖先种群扩散而来。由于褐家鼠喜欢与人伴生,褐家鼠很可能随着黎族人在新石器时代中期(大约3 000年前)或更早以前,从广西、广东沿海地区迁移至海南。     

FUNDC1 regulates mitochondrial dynamics at the ER–mitochondrial contact site under hypoxic conditions

In hypoxic cells, dysfunctional mitochondria are selectively removed by a specialized autophagic process called mitophagy. The ER–mitochondrial contact site (MAM) is essential for fission of mitochondria prior to engulfment, and the outer mitochondrial membrane protein FUNDC1 interacts with LC3 to recruit autophagosomes, but the mechanisms integrating these processes are poorly understood. Here, we describe a new pathway mediating mitochondrial fission and subsequent mitophagy under hypoxic conditions. FUNDC1 accumulates at the MAM by associating with the ER membrane protein calnexin. As mitophagy proceeds, FUNDC1/calnexin association attenuates and the exposed cytosolic loop of FUNDC1 interacts with DRP1 instead. DRP1 is thereby recruited to the MAM, and mitochondrial fission then occurs. Knockdown of FUNDC1, DRP1, or calnexin prevents fission and mitophagy under hypoxic conditions. Thus, FUNDC1 integrates mitochondrial fission and mitophagy at the interface of the MAM by working in concert with DRP1 and calnexin under hypoxic conditions in mammalian cells.