Respiratory syncytial virus (RSV) is the most commonly identified viral agent in young children

BackgroundThe Tibetan Plateau is not only the highest and largest plateau on earth; it is also home to numerous freshwater lakes potentially harbouring endemic faunal elements. As it remains largely unknown whether these lakes have continuously existed during the Last Glacial Maximum (LGM), questions arise as to whether taxa have been able to exist on the plateau since before the latest Pleistocene, from where and how often the plateau was colonized, and by which mechanisms organisms conquered remote high altitude lentic freshwater systems. In this study, species of the plateau-wide distributed freshwater gastropod genus Radix are used to answer these biogeographical questions.Methodology/Principal FindingsBased on a broad spatial sampling of Radix spp. on the Tibetan Plateau, and phylogenetic analyses of mtDNA sequence data, three probably endemic and one widespread major Radix clade could be identified on the plateau. Two of the endemic clades show a remarkably high genetic diversity, indicating a relatively great phylogenetic age. Phylogeographical analyses of individuals belonging to the most widely distributed clade indicate that intra-plateau distribution cannot be explained by drainage-related dispersal alone.Conclusions/SignificanceOur study reveals that Radix spp. persisted throughout the LGM on the Tibetan Plateau. Therefore, we assume the continuous existence of suitable water bodies during that time. The extant Radix diversity on the plateau might have been caused by multiple colonization events combined with a relatively long intra-plateau evolution. At least one colonization event has a Palaearctic origin. In contrast to freshwater fishes, passive dispersal, probably by water birds, might be an important mechanism for conquering remote areas on the plateau. Patterns found in Radix spp. are shared with some terrestrial plateau taxa, indicating that Radix may be a suitable model taxon for inferring general patterns of biotic origin, dispersal and survival on the Tibetan Plateau.

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We investigated the phylogeny of the viviparid genus Margarya, endemic to Yunnan, China, using two mitochondrial gene fragments (COI and 16S rRNA). The molecular phylogeny based on the combined dataset indicates that Margarya is polyphyletic, as two of the three well-supported clades containing species of Margarya also comprise species from other viviparid genera. In one clade, sequences of four species of Margarya even cluster indiscriminately with those of two species of Cipangopaludina, indicating that the current state of Asian viviparid taxonomy needs to be revised. Additionally, these data suggest that shell evolution in viviparids is complex, as even the large and strongly sculptured shells of Margarya, which are outstanding among Asian viviparids, can apparently be easily converted to simple smooth shells. The molecular data also indicate that the species status of the six extant species of Margarya should be reassessed .

Nelson Bay orthoreovirus (NBV) is a species in the genus Orthoreovirus, family Reoviridae, containing 4, possibly 5, members. Here, we report a putative sixth member, Xi River virus (XRV), isolated from fruit bats collected in a location near the Xi River, Guangdong Province, China. This virus showed the same electron microscopic morphology as NBV, fusogenic CPE, and a 10-segmented double-strand RNA genome, as well as high sequence identity to NBV members. It is the first bat reovirus isolated in China.

This paper presents a three-dimensional (3D) range migration algorithm (RMA) suitable for downward-looking 3D-SAR with single-transmitting and multiple-receiving linear array antennas (STMR-LAA). As the round-trip range equation in 3D-SAR with STMR-LAA is a dual square root, the signal spectrum in 3D wavenumber domain contains nonlinear phase terms besides constant and linear phase terms. In this paper, the approximate expression of the signal spectrum is derived by expanding the implicit phase term to its Taylor series. Then the constant and nonlinear phase terms are calculated and compensated by multiplying the wavenumber filters. Finally, a 3D wavenumber mapping is proposed to make the signal evenly sampled in 3D wavenumber domain. Some simulating results are presented to validate the correctness of the analysis and the feasibility of the algorithm. In addition, the required accuracy on the platform position is analyzed at the end of the paper.

a b s t r a c tIn this paper, three historical biodiversity datasets (from 1940s, 1980-1999 and 2000-2004) and results from the recent inventory are used to trace the long-term changes of the mollusks in the eutrophic Lake Dianchi. Comparison of the obtained results with those of earlier investigations performed during the period of 1940s and 1980-1999 as well as [2000][2001][2002][2003][2004] showed that changes have occurred in the interval. There were 31 species and 2 sub-species recorded prior to the 1940s, but the species richness decreased from a high level of 83 species and 7 sub-species to 16 species and one sub-species from 1990s to the early of 21st century in lake body. Species from the genera of Kunmingia, Fenouilia, Paraprygula, Erhaia, Assiminea, Galba, Rhombuniopsis, Unionea and Aforpareysia were not found in Dianchi basin after 2000. The species from the genera Lithoglyphopsis, Tricula, Bithynia, Semisulcospira and Corbicula were only found in the springs and upstream rivers. Anoxia and the changing of substrates and fish species composition could explain why molluscan community composition changed in eutrophic Lake Dianchi. Additionally, the different sampling methods and ignore of the specific groups in earlier studies are cause for Sphaerium and Pisidium first found in our study. This study is first time to enlarge the investigation region to the Dianchi basin. Although some endemic species disappeared in the lake body, they still distribute in the springs and upstream rivers. The springs and upstream rivers are important refuges for mollusks.

The loach genus Oreonectes is reviewed in this study. Six valid species are recognized, including two new species. Oreonectes polystigmus sp. nov., and Oreonectes microphthalmus sp. nov. are described from the Guangxi Zhuang Autonomous Region, China. Among its congeners, O. polystigmus is most similar to O. platycephalus in morphology. It can be distinguished from all its congeners by an incomplete lateral line with 6–8 pores; a cephalic lateral-line system with 7 supraorbital and 4+7 infraorbital pores; sexual dimorphism (males have a genital papilla located immediately posterior of the anus, and the gonad is opened at the end of a fleshy prominence); and a body with many differently shaped spots. Oreonectes microphthalmus is most similar to O. furcocaudalis in morphology. It can be distinguished from all congeners by its degenerate eyes, which only have black pigment; a cephalic lateral-line system with 2+2 supratemporal, 7 supraorbital, 3+0 infraorbital and 8 preoperculomandibular pores; and an incomplete lateral line with 3 pores. A key to all valid Oreonectes species is provided. The validity of some related species is discussed. Nemacheilus liboensis, Oreonectes liboensis and Oreonectes translucens are all proved to be synonyms of Paracobitis longibarbatus, and Paracobitis longibarbatus is actually a species of Triplophysa.