Characterization and Preparation of Bimetallic Nanoparticles

1 Results Bimetallic particles in the nanometer size range are of substantial interest due to their vast applications in catalysis[1].The synthesis of bimetallic nanoparticles with definite size with a well-control over their nanostructure remains a challenging problem.Thus there exists a great demand for both synthesis and atomic level characterization of nanostructure of bimetallic nanoparticles (NPs).With the recent advent of high-intensity tunable sources of X-rays,now available at synchrotron radia...     

Tissue-specific and reversible RNA interference in transgenic mice

Genetically engineered mice provide powerful tools for understanding mammalian gene function. These models traditionally rely on gene overexpression from transgenes or targeted, irreversible gene mutation. By adapting the tetracycline (tet)-responsive system previously used for gene overexpression, we have developed a simple transgenic system to reversibly control endogenous gene expression using RNA interference (RNAi) in mice. Transgenic mice harboring a tet-responsive RNA polymerase II promoter driving a microRNA-based short hairpin RNA targeting the tumor suppressor Trp53 reversibly express short hairpin RNA when crossed with existing mouse strains expressing general or tissue-specific 'tet-on' or 'tet-off' transactivators. Reversible Trp53 knockdown can be achieved in several tissues, and restoring Trp53 expression in lymphomas whose development is promoted by Trp53 knockdown leads to tumor regression. By leaving the target gene unaltered, this approach permits tissue-specific, reversible regulation of endogenous gene expression in vivo, with potential broad application in basic biology and drug target validation.     

Recombination and linkage disequilibrium in Arabidopsis thaliana

Linkage disequilibrium (LD) is a major aspect of the organization of genetic variation in natural populations. Here we describe the genome-wide pattern of LD in a sample of 19 Arabidopsis thaliana accessions using 341,602 non-singleton SNPs. LD decays within 10 kb on average, considerably faster than previously estimated. Tag SNP selection algorithms and 'hide-the-SNP' simulations suggest that genome-wide association mapping will require only 40%-50% of the observed SNPs, a reduction similar to estimates in a sample of African Americans. An Affymetrix genotyping array containing 250,000 SNPs has been designed based on these results; we demonstrate that it should have more than adequate coverage for genome-wide association mapping. The extent of LD is highly variable, and we find clear evidence of recombination hotspots, which seem to occur preferentially in intergenic regions. LD also reflects the action of selection, and it is more extensive between nonsynonymous polymorphisms than between synonymous polymorphisms.     

The neuronal sortilin-related receptor SORL1 is genetically associated with Alzheimer disease

The recycling of the amyloid precursor protein (APP) from the cell surface via the endocytic pathways plays a key role in the generation of amyloid beta peptide (Abeta) in Alzheimer disease. We report here that inherited variants in the SORL1 neuronal sorting receptor are associated with late-onset Alzheimer disease. These variants, which occur in at least two different clusters of intronic sequences within the SORL1 gene (also known as LR11 or SORLA) may regulate tissue-specific expression of SORL1. We also show that SORL1 directs trafficking of APP into recycling pathways and that when SORL1 is underexpressed, APP is sorted into Abeta-generating compartments. These data suggest that inherited or acquired changes in SORL1 expression or function are mechanistically involved in causing Alzheimer disease.     

Gastrointestinal helminths of nine species of Cnemaspis (Squamata: Gekkonidae) from Peninsular Malaysia,one species from Cambodia and Thailand and two species from Vietnam

A total of 12 species of Cnemaspis (N = 104) from Southeast Asia were examined for gastrointestinal helminths. Samples consisted of nine species (n = 86) from Peninsular Malaysia: Cnemaspis affinis (n = 4); Cnemaspis baueri (n = 17); Cnemaspis biocellata (n = 12); Cnemaspis grismeri (n = 8); Cnemaspis kumpoli (n = 11); Cnemaspis limi (n = 9): Cnemaspis monachorum (n = 7); Cnemaspis pemanggilensis (n = 10); Cnemaspis peninsularis (n = 8); one species (n = 5) from Cambodia and Thailand, Cnemaspis chanthaburiensis (n = 5); and two species (n = 13) from Vietnam: Cnemaspis nuicamensis (n = 6) and Cnemaspis tucdupensis (n = 7). The aggregate helminth community consisted of one species of Cestoda, Cylindrotaenia malayi and nine species of Nematoda: Bakeria schadi, Meteterakis singaporensis, Parapharyngodon maplestoni, Maxvachonia sp., Physalopteroides sp., Physalopteridae gen. sp., Riticulariidae gen. sp., Seuratoidea gen. sp., Ascaridoidea gen. sp. Meteterakis singaporensis had the largest number of individuals (457) and greatest prevalence (24%). Twenty-eight new host records are reported.     

A new species of Schizopera (Copepoda: Harpacticoida) from Japan,its phylogeny based on the mtCOI gene and comments on the genus Schizoperopsis

The predominantly marine genus Schizopera Sars, 1905 has only two significant inland water species-flocks, one in the ancient African Lake Tanganyika and the other in subterranean waters of Western Australia. Discovery of Schizopera abei sp. nov. from several interstitial locations in the vicinity of the ancient Lake Biwa has wider implications for the study of morphological homoplasies in the genus, as well as for the study of freshwater invasions in harpacticoid copepods. The new Schizopera species belongs to a small group of congeners with a two-segmented endopod of the fourth leg, which used to be recognised as a separate genus, Schizoperopsis Apostolov, 1982. Our reconstructed phylogenies based on the mtCOI partial sequences suggest that this character probably evolved convergently in at least some Schizopera, thus rendering the genus Schizoperopsis polyphyletic. However, almost all basal nodes in our cladograms are weakly supported, which shows limitations of a single-gene approach for reconstructing phylogenetic relationships. The new species is the first member of its genus from Japanese inland waters, and it has no close relatives among extent congeners anywhere in the world. We speculate that its ancestor may have invaded Lake Biwa, and subsequently its surrounding subterranean waters, from brackish areas around central Japan, presumably during a period of high sea water level through its major outflow river. This discovery may provide further support for the hypothesis about the role of ancient lakes as biodiversity pumps for subterranean habitats.

http://zoobank.org/urn:lsid:zoobank.org:pub:1F71F7AD-B7C8-4AD3-BE44-5E1BEE4E2AA8