Amplification and sequencing of Trichuris trichiura ancient DNA extracted from archaeological sediments

Despite high prevalence of Trichuris trichiura infection, PCR-based analysis on T. trichiura from archaeological samples has not been established so far. In the present study, we sought to perform PCR-based amplification of T. trichiura aDNA using the sediments from medieval tomb of Korea. The presence of Trichuris eggs were first detected by microscopic observation; then confirmed by PCR-based aDNA analysis. Obtained sequence showed 100% homology to that of the small subunit ribosomal RNA (SSUrRNA) gene of T. trichiura but distinct from that of other Trichuris species. PCR-based aDNA analysis in this study can serve as effective method to confirm the presence of T. trichiura eggs in the soils or coprolites collected from archaeological sites.     

SUFFICIENT CONDITIONS FOR NEGATIVE EXPONENTIAL DENSITIES A FURTHER ANALYSIS

ABSTRACT Brueckner correctly pointed out that one of the sufficient conditions for negative exponential densities is a unitary price elasticity of the compensated, not the uncompensated, demand for housing. This note shows that the Brueckner condition implies a zero income elasticity of housing demand when income and price elasticities are constrained to be constants. It also derives the utility function that gives rise to negative exponential densities in this case, given that other standard assumptions are satisfied. In light of empirical evidence, justification for the popular negative exponential functional form seems rather weak.     

Seismic Hazard Analysis Using Discrete Faults in Northwestern Pakistan: Part I – Methodology and Evaluation

This article is the first of two companion articles that evaluate the seismic hazard in northwestern Pakistan. The area, located at the western edge of the Himalayas, has numerous active faults including the Main Boundary Thrust (MBT) and Main Mantle Thrust (MMT). This article describes the methodology used to perform regional deterministic and probabilistic seismic hazard analyses. Here, seismic sources were defined from 32 identified faults while prior studies have been based on diffuse seismicity and areal source zones. Fault parameters were selected using available data and empirical correlations for faults elsewhere. Recurrence relations were constructed for all discrete faults based on both historical and instrumented seismicity in addition to geologic evidence. Due to lack of region specific attenuation relationships, four plate boundary attenuation relations from the Next Generation Attenuation of Ground Motions Project [Abrahamson et al., 2008 Abrahamson, N., Atkinson, G., Boore, D., Bozorgnia, Y., Campbell, K., Chiou, B., Idriss, I. M., Silva, W. and Youngs, R. 2008. Comparisons of the NGA ground-motion relations. Earthquake Spectra, 24(1): 45–66. [Crossref], [Web of Science ®] , [Google Scholar]] were employed to predict ground motions. Predicted ground motion parameters are compared to measurements from the recent 2005 Kashmir earthquake. In the companion article, the methodology developed and evaluated here is used to conduct deterministic and probabilistic seismic hazard analyses for the entire study region.