grassland and not going anywhere are no longer cowpaths. The photograph shows the currently used paths in the grassland bowed toward the lower left by encroaching shrubs while faint scars above reveal where the paths once passed. In the grassland these old paths are obliterated by grass; in the shrub zone they remain bare and become broader. The great broad white zones of bare ground both insid...

Reanalysis and direct accelerator mass spectrometry radiocarbon dating of the cucurbit assemblage from Coxcatlan Cave provide information on the timing and sequence of the initial appearance of three domesticated plants in the Tehuacán Valley (Puebla, Mexico) and allow reassessment of the overall temporal context of plant domestication in Mexico. Cucurbita pepo is the earliest documented domest...

Even though the faba bean (Vicia faba L.) is among the most ubiquitously cultivated crops, very little is known about its origins. Here, we report discoveries of charred faba beans from three adjacent Neolithic sites in the lower Galilee region, in the southern Levant, that offer new insights into the early history of this species. Biometric measurements, radiocarbon dating and stable carbon is...

Above-ground thermonuclear weapons testing from 1952 through 1962 nearly doubled the concentration of radiocarbon ((14)C) in the atmosphere. As a result, organic material formed during or after this period may be radiocarbon-dated using the abrupt rise and steady fall of the atmospheric (14)C concentration known as the bomb-curve. We test the accuracy of accelerator mass spectrometry radiocarbo...

Bayesian methods are now widely used for analysing radiocarbon dates. We find that the non-informative priors in use in the literature generate a bias towards wider date ranges which does not in general reflect substantial prior knowledge. We recommend using a prior in which the distribution of the difference between the earliest and latest dates has a uniform distribution. We show how such pri...

Cycads in South Africa are facing an extinction crisis due to the illegal extraction of plants from the wild. Proving wild origin of suspect ex situ cycads to the satisfaction of a court of law is difficult, limiting law enforcement efforts. We investigated the feasibility of using multiple stable isotopes to identify specimens removed from the wild. Relocated and wild specimens from two specie...

[1] The vertical and spatial structure of the atmospheric El Niño-Southern Oscillation (ENSO) signal is investigated using radio occultation (RO) data from August 2006 to December 2010. Due to their high vertical resolution and global coverage, RO data are well suited to describe the full 3-dimensional ENSO structure in the troposphere and lower stratosphere. We find that interannual temperatur...

The continental drift, or more generally the mobilism controversy lasted sixty years. It was the longest and most important controversy of the last century in Earth science, and one of the more important in all of science in that period. Within it were many sub-controversies and their important feature was that some were long-lived too, even surviving the controversy itself. For example, the ap...

We present a simple argument that the missing x-ray flux from the Galactic Center source Sgr A* ist not evidence against – as claimed by Goldwurm et al. 1994 – but rather indirect evidence for the presence of a supermassive black hole. The radio spectrum provides a strict lower limit for the size of Sgr A* (R > 3 · 10cm). A more compact source would be completely synchrotron self-absorbed. This...

Radio frequency interference (RFI) has plagued radio astronomy from its inception. The Workshop on the Mitigation of Radio Frequency Interference in Radio Astronomy (RFI2004) was held in Penticton, BC, Canada in July 2004 in order to consider the prognosis for the RFI problem, in particular as it impacts the planned Square Kilometre Array (SKA). This paper concludes that RFI is unlikely to be a...