13 research outputs found
Preservation of viral genomes in 700-y-old caribou feces from a subarctic ice patch
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
Educational attainment and the (growing) importance of age structure: Indigenous and non-indigenous Australians
Propagation of Stationary Planetary Waves in the Upper Atmosphere under Different Solar Activity
Division of family property in Taiwan
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
A Holocene calcrete from North Yorkshire, England: implications for interpreting palaeoclimates using calcretes
A new method for assaying propantheline and its degradation product, xanthene-9- carboxylic acid using high performance liquid chromatography
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