13 research outputs found

    Preservation of viral genomes in 700-y-old caribou feces from a subarctic ice patch

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    Viruses preserved in ancient materials provide snapshots of past viral diversity and a means to trace viral evolution through time. Here, we use a metagenomics approach to identify filterable and nuclease-resistant nucleic acids preserved in 700-y-old caribou feces frozen in a permanent ice patch. We were able to recover and characterize two viruses in replicated experiments performed in two different laboratories: a small circular DNA viral genome (ancient caribou feces associated virus, or aCFV) and a partial RNA viral genome (Ancient Northwest Territories cripavirus, or aNCV). Phylogenetic analysis identifies aCFV as distantly related to the plant-infecting geminiviruses and the fungi-infecting Sclerotinia sclerotiorum hypovirulence-associated DNA virus 1 and aNCV as within the insect-infecting Cripavirus genus. We hypothesize that these viruses originate from plant material ingested by caribou or from flying insects and that their preservation can be attributed to protection within viral capsids maintained at cold temperatures. To investigate the tropism of aCFV, we used the geminiviral reverse genetic system and introduced a multimeric clone into the laboratory model plant Nicotiana benthamiana. Evidence for infectivity came from the detection of viral DNA in newly emerged leaves and the precise excision of the viral genome from the multimeric clones in inoculated leaves. Our findings indicate that viral genomes may in some circumstances be protected from degradation for centuries

    Division of family property in Taiwan

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    Since property ownership affords the elderly some control over resources and perhaps even support and respect from potential caretakers, examination of the decision to transfer property to children can help us gain insight into the underlying dynamics of intergenerational exchanges between the elderly and their children. In this paper we use data from the 1989 Survey of Health and Living Status of the Elderly in Taiwan to explore the demographic and social characteristics associated with pre-mortem property division. From both bivariate and multivariate analyses, we find that the likelihood of property division is positively related to age, widowhood, natality in Taiwan, rural residence, and the number of living children, and negatively related to education. After controlling for other characteristics, our results show that widows are more than twice as likely as widowers to have divided all their property. These results lend statistical support to findings in the ethnographic literature on the Chinese family.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/42992/1/10823_2004_Article_BF00973799.pd

    Metallothioneins in Drug Resistance

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    A new method for assaying propantheline and its degradation product, xanthene-9- carboxylic acid using high performance liquid chromatography

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    A rapid, specific, and precise high-performance liquid chromatographic method is described for the simultaneous analysis of propantheline bromide and its hydrolysis product, xanthene-9-carboxylic acid. Reversed-phase chromatography was conducted using a mobile phase of 40:60, acetonitrile-0.05 M phosphate buffer (pH 2.5) delivered at 2 ml/min. Detection was at 254 nm. Methantheline bromide (internal standard), propantheline bromide, and xanthene-9-carboxylic acid gave retention times of 4.1, 5.4, and 8.3 min, respectively. Within-day, between-day, and total precision (CV) for assay of 15 mg/10 ml propantheline bromide are 1.2, 1.1, and 1.6%, respectively (n = 20). Similar precision was obtained for xanthene-9-carboxylic acid. The limit of detection was 2 ng. The assay is useful for routine quality assurance of propantheline in dosage forms and for stability and kinetic studies
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