Two co-authored articles in Nature (Haak et al., 2015; Allentoft et al., 2015) caused a sensation. They revealed genetically the mass migration of steppe Yamnaya culture people in the Early Bronze Age to central and northern Europe. The authors considered this event as the basis of the spread of Indo-European languages. In response, the Russian archaeologist, Leo S. Klejn, expresses critical remarks on the genetic inference, and in particular its implications for the problem of the origins of Indo-European languages. These remarks were shown to the authors and they present their objections. Klejn, however, has come to the conclusion that the authors’ objections do not assuage his doubts. He analyses these objections in a further response.

Focused 30keV gallium ion beam, single-pixel drilling combined with backside particle detection is used to fabricate pores having exit diameters as small as ~11 nm in 200 nm-thick silicon nitride membranes. The backside channelplate detector response obtained about the onset of breakthrough is interpreted by plan-view transmission electron microscopy investigations of hole morphology. Immediately prior to breakthrough, there is a rise in detector signal as the local membrane thickness is reduced. This likely occurs as a result of ion transmission and, possibly, forward sputtering. At the dose required for breakthrough a maximum detector signal is obtained thus providing a potential method for end point detection. The focused ion drilling technique avoids broad area beam exposure methods that are often used to reduce hole diameter to nanometer dimension. In addition, the current approach overcomes difficulties in determining a required dose for breakthrough such as those that arise from an inhomogeneous membrane thickness, redeposition, or ion channeling.

This paper applies the ‘choice experiment’ method to investigate public preferences over the design of wild goose conservation policy in Scotland. We argue that this method can shed useful light on the design of conservation policy, allowing policy-makers to take account of people's preferences, be they members of the general public (whose taxes often pay for conservation actions), local residents more directly affected by the policy, or visitors to wildlife areas. Preferences can be quantified in economic terms, so that the costs and benefits of different policy designs can be compared. In our study, we find that the general public, local residents and visitors have very different preferences for the conservation of geese. Whether geese are shot, the endangered status of geese, the spatial targeting of conservation and the size of the goose population all have impacts on the perceived benefits of conservation. In general, though, people are willing to pay for wild geese conservation.