Livestock Husbandry between Ethics and Economics: Finding a Feasible Way Out by Target Costing?

Livestock husbandry is a major line of conflict in many industrialized countries. Farmers are caught in a dilemma between ethical considerations imposed by, for instance, nongovernmental organizations and the wider public on the one hand and competitive and economic pressures on the other. In this paper we use a target-costing approach to determine whether it is possible to implement more animal-friendly husbandry conditions for turkey fattening in Germany without sacrificing competitiveness. Empirical results show that, at first glance, the willingness on the part of consumers to pay for more animal welfare exceeds the costs to farmers of more animal-friendly husbandry systems. A critical discussion reveals that this result may be flawed by methodological problems for which no solutions have yet been found.animal welfare, livestock husbandry, target costing, willingness to pay, Livestock Production/Industries, D12, D63, Q12,

Existence and Vanishing of the Breathing Mode in Strongly Correlated Finite Systems

One of the fundamental eigenmodes of finite interacting systems is the mode of {\em uniform radial expansion and contraction} -- the ``breathing'' mode (BM). Here we show in a general way that this mode exists only under special conditions: i) for harmonically trapped systems with interaction potentials of the form $1/r^\gamma$ $(\gamma\in\mathbb{R}_{\neq0})$ or $\log(r)$, or ii) for some systems with special symmetry such as single shell systems forming platonic bodies. Deviations from the BM are demonstrated for two examples: clusters interacting with a Lennard-Jones potential and parabolically trapped systems with Yukawa repulsion. We also show that vanishing of the BM leads to the occurence of multiple monopole oscillations which is of importance for experiments

Ground state of a confined Yukawa plasma

The ground state of an externally confined one-component Yukawa plasma is derived analytically. In particular, the radial density profile is computed. The results agree very well with computer simulations on three-dimensional spherical Coulomb crystals. We conclude in presenting an exact equation for the density distribution for a confinement potential of arbitrary geometry.Comment: 5 pages, 4 figure

Formation and structure of calcium carbonate thin films and nanofibers precipitated in the presence of poly(allylamine hydrochloride) and magnesium ions

That the cationic polyelectrolyte poly(allylamine hydrochloride) (PAH) exerts a significant influence on CaCO₃ precipitation challenges the idea that only anionic additives have this effect. Here, we show that in common with anionic polyelectrolytes such as poly(aspartic acid), PAH supports the growth of calcite thin films and abundant nanofibers. While investigating the formation of these structures, we also perform the first detailed structural analysis of the nanofibers by transmission electron microscopy (TEM) and selected area electron diffraction. The nanofibers are shown to be principally single crystal, with isolated domains of polycrystallinity, and the single crystal structure is even preserved in regions where the nanofibers dramatically change direction. The formation mechanism of the fibers, which are often hundreds of micrometers long, has been the subject of intense speculation. Our results suggest that they form by aggregation of amorphous particles, which are incorporated into the fibers uniquely at their tips, before crystallizing. Extrusion of polymer during crystallization may inhibit particle addition at the fiber walls and result in local variations in the fiber nanostructure. Finally, we investigate the influence of Mg²+ on CaCO₃ precipitation in the presence of PAH, which gives thinner and smoother films, together with fibers with more polycrystalline, granular structures

Regionalwirtschaftliche Effekte veränderter Wassernutzung in Nordost-Niedersachsen

Mit der Wasserrahmenrichtlinie hat die EU einen juristischen Rahmen geschaffen, alle aquatischen Ökosysteme, zu denen auch die Grundwasserkörper gehören, zu schützen. Diese vornehmlich auf den Wasserschutz abzielende Maßnahme zieht neben klaren Vorteilen für den Wasserhaushalt und die -versorger möglicherweise auch Vor- wie Nachteile für landwirtschaftliche Betriebe wie landwirtschaftlich geprägte Regionen nach sich. Mit dem vorliegenden Beitrag wird untersucht, welche regionalen Effekte eine verminderte Beregnung für eine der am stärksten von Trockenheit betroffenen Regionen Nordostniedersachsen besitzen würde. Mit Hilfe des Regionalmodels „POMMARD“ wurden die regionalen Effekte (a) einer Halbierung des verfügbaren Beregnungswassers sowie (b) eines vollständigen Verzichts auf Beregnung projiziert. Die Ergebnisse zeigen, dass eine Beschränkung der Wasserentnahmeerlaubnisse schwach negative Konsequenzen für die Region besitzt. Der vollständige Verzicht auf Beregnung dagegen hat deutliche Auswirkungen sowohl auf den Agrarsektor als auch auf die regionale Entwicklung. Die Wasserrahmenrichtlinie kann deshalb bei sachgerechter Festlegung der Entnahmemengen für Feldberegnung als eine Möglichkeit gesehen werden, die Wassernutzungseffizienz zu erhöhen und gleichzeitig natürliche Ressourcen zu schonen.Feldberegnung, Input-Output Analyse, Systemdynamiken, Regionale Wirtschaftskreisläufe, Environmental Economics and Policy,