Observation of Free-Space Single-Atom Matterwave Interference

We observe matterwave interference of a single cesium atom in free fall. The interferometer is an absolute sensor of acceleration and we show that this technique is sensitive to forces at the level of $3.2\times10^{-27}$ N with a spatial resolution at the micron scale. We observe the build up of the interference pattern one atom at a time in an interferometer where the mean path separation extends far beyond the coherence length of the atom. Using the coherence length of the atom wavepacket as a metric, we directly probe the velocity distribution and measure the temperature of a single atom in free fall.Comment: 5 pages, 4 figure

Noch Platz für Nischen? - Bedeutung und Potential alter und gefährdeter Rinderrassen im Ökologischen Landbau

Not only the biodiversity of wild species, but also the diversity in livestock is declining rapidly: Out of 6.300 registered livestock breeds in the world 1.250 are endangered or already extinct. In Germany 16 out of 32 cattle breeds are endangered, while three of the most popular cattle breeds make up 92 % of the more than two million herd-book cows. Due to their adaptation to local conditions on first sight many rare and endangered cattle breeds appear to be well suited for organic farming systems, but the percentage of rare breeds on organic farms is not much higher than on conventional ones. Council Regulation (EC) No 1804/1999 on livestock production in organic farming recommends to encourage biological diversity and to favour the use of breeds which are already adopted to the local conditions. This paper summarises a study on the motivations of organic farmers for keeping rare and endangered cattle breeds, and on which role breeding issues and livestock biodiversity play for organic farming organisations and controlling agencies. The main reasons for keeping rare cattle breeds were good fodder utilization, low susceptibility to diseases, good adaptation to local conditions, but above all a personal relation to a specific breed. Conservation aspects and breed-specific subsidies were of lower importance. Nevertheless, husbandry of rare cattle breeds should be economically viable. Unfortunately most organic farming organisations and controlling agencies hardly touched on breeding and choice-of-breed aspects in their advisory work; they more or less shared the view that the issue was of minor importance for organic farms. The paper concludes with a vision under which conditions rare cattle breeds could be better integrated into organic farming systems and on how organic farming could contribute to the in-situ conservation of livestock genetic resources

Homotopy nilpotent groups

We study the connection between the Goodwillie tower of the identity and the lower central series of the loop group on connected spaces. We define the simplicial theory of homotopy n-nilpotent groups. This notion interpolates between infinite loop spaces and loop spaces. We prove that the set-valued algebraic theory obtained by applying $\pi_0$ is the theory of ordinary n-nilpotent groups and that the Goodwillie tower of a connected space is determined by a certain homotopy left Kan extension. We prove that n-excisive functors of the form $\Omega F$ have values in homotopy n-nilpotent groups.Comment: 16 pages, uses xy-pic, improved exposition, submitte

Pion scattering in Wilson ChPT

We compute the scattering amplitude for pion scattering in Wilson chiral perturbation theory for two degenerate quark flavors. We consider two different regimes where the quark mass m is of order (i) a\Lambda_QCD^2 and (ii) a^2\Lambda_QCD^3. Analytic expressions for the scattering lengths in all three isospin channels are given. As a result of the O(a^2) terms the I=0 and I=2 scattering lengths do not vanish in the chiral limit. Moreover, additional chiral logarithms proportional to a^2\ln M_{\pi}^2 are present in the one-loop results for regime (ii). These contributions significantly modify the familiar results from continuum chiral perturbation theory.Comment: 20 pages, 4 figures. V3: Comments on finite size effects and the axial vector current added, one more reference. To be published in PR

The Army lessons process: supporting individual and organisational learning in the Australian Army

This paper provides a brief outline of the Army lessons process that is applied when developing and applying lessons across all Army activities. The Army lessons process supports the conduct of operations and informs Army Raise-Train-Sustain functions, through the incorporation of lessons into doctrine, training and capability development. The paper focuses upon four distinct foci. Firstly, we examine the whole of Army responsibility in relation to the transfer of knowledge into lessons. Secondly, we consider the vital roles and responsibilities of knowledge authorities in this transfer. Thirdly, we examine the ways in which observations and insights transform into findings and lessons. Finally, we propose the establishment of the Army Lessons Network as a formal means of knowledge interaction