Simulation of Wave Propagation Used for the Detection of Submerged Stone Age Artifacts

With the expansion of industrial digging in the sea for construction of traditional and alternative energy sources, there is a growing need to quickly identify submerged indigenous archeological sites. The two main methods used outside of this research are insufficient: 1) The use of high-frequency (600 – 2000 kHz) sound waves by way of side-scan sonar; 2) Using geophysics to identify landmarks that could have attracted pre-contact (indigenous) people. Morgan Smith and his team are using a sub-bottom profiler (SBP) to more accurately identify submerged cultural artifacts, as the SBP allows for lower-frequency (4 – 24 kHz) sound waves that more closely match resonance frequencies of stone artifacts. In conjunction with experimental data gathered from sea beds in relatively shallow waters, we are using the finite element method to numerically solve a mathematical model based on the elastic wave partial differential equation. Appropriate specification of the parameters in this model allows for the simulation of wave propagation in various media, in particular water as well as layered soil and rock. The success of this collaborative effort will result in a significant increase in the speed at which sites can be cleared for construction and the number of submerged indigenous archeological sites that are preserved

Global Instability in Experimental General Equilibrium: The Scarf Example

Scarf (1960) proposed a market environment and a model of dynamic adjustment in which the standard tatonnement price adjustment process orbits around, rather than converges to, the competitive equilibrium. Hirota (1981) characterized the price paths by the configuration of endowments. We explore the predictions of Scarf's model in a nontatonnement experimental double auction. We find that the average transaction prices in each period do follow the path predicted by the Scarf and Hirota models. When the model predicts prices will converge to the competitive equilibrium, our data converge; when the model predicts prices will orbit our data orbit the equilibrium, and in the direction predicted by the model. Moreover, we observe a weak tendency for prices within a period to follow the path predicted by the model

The barley pan-genome reveals the hidden legacy of mutation breeding

Genetic diversity is key to crop improvement. Owing to pervasive genomic structural variation, a single reference genome assembly cannot capture the full complement of sequence diversity of a crop species (known as the ‘pan-genome’1). Multiple high-quality sequence assemblies are an indispensable component of a pan-genome infrastructure. Barley (Hordeum vulgare L.) is an important cereal crop with a long history of cultivation that is adapted to a wide range of agro-climatic conditions2. Here we report the construction of chromosome-scale sequence assemblies for the genotypes of 20 varieties of barley—comprising landraces, cultivars and a wild barley—that were selected as representatives of global barley diversity. We catalogued genomic presence/absence variants and explored the use of structural variants for quantitative genetic analysis through whole-genome shotgun sequencing of 300 gene bank accessions. We discovered abundant large inversion polymorphisms and analysed in detail two inversions that are frequently found in current elite barley germplasm; one is probably the product of mutation breeding and the other is tightly linked to a locus that is involved in the expansion of geographical range. This first-generation barley pan-genome makes previously hidden genetic variation accessible to genetic studies and breeding

Global instability in experimental general equilibrium: the Scarf example

Scarf (Int. Econ. Rev. 1 (1960) 157) proposed a model of dynamic adjustment in which the standard tatonnement price adjustment process orbits around, rather than converges to, the competitive equilibrium. Hirota (Int. Econ. Rev. 22 (1981) 461) characterized the price paths. We explore the predictions of Scarf's model in a non-tatonnement experimental double auction. The average transaction prices in each period do follow the path predicted by the Scarf and Hirota models. When the model predicts convergence the data converge; when the model predicts orbits, the data orbit in the direction predicted by the model. Moreover, we observe a weak tendency for prices within a period to follow the path predicted by the model

Characterization of cilia beat frequency and mucociliary transport in racetrack cultures.

A) Average cilia beat frequency for each quadrant of two separate cultures. B) Overall average cilia beat frequency from five cultures. C) Mean MCT rates of beads in PBS for five separately prepared and evaluated cultures. Data is representative of the average and standard deviation of ≥3 individual measurements.</p