Goats : rising systems and trading alternatives

Este trabajo propone caracterizar la producción caprina del norte y oeste de Córdoba (Argentina). Para ello analiza diacrónica y sincrónicamente los datos censales a nivel provincial y focaliza el relevamiento de datos productivos en la región NO de la provincia. Luego establece las distintas estrategias de comercialización del producto principal, el cabrito: • venta directa 48 % • venta a intermediario 28 % • reposición 14 % • consumo 10 %This paper aims to characterise goat production in the North and West of Córdoba (Argentina). It analises the literature at the provincial level both diachronicaly and sinchronicaly, focusing the data survey on the NW area. The paper concludes that there are different channels for trading goat-kids (the main product sent by peasants to the market): • direct sales to final consumers 48 % • to middlemen 28 % • female kids to replace old goats 14 % • and meat for peasant households 10 %Fil: Ferrer, G.. Universidad Nacional de CórdobaFil: Barrientos, M.. Universidad Nacional de CórdobaFil: Saal, G.. Universidad Nacional de CórdobaFil: Visintini, A.. Universidad Nacional de Córdob

Pinning forces of sliding drops at defects

Wetting of surfaces depends critically on defects which alter the shape of the drop. However, no experimental verification of forces owing to the three phase contact line deformation at single defects is available. We imaged the contact line of sliding drops on hydrophobic surfaces by video microscopy. From the deformation of the contact line, we calculate the force acting on a sliding drop using an equation going back to Joanny and de Gennes (J. Chem. Phys., 81 (1984) 554). The calculated forces quantitatively agree with directly measured forces acting between model defects and water drops. In addition, both forces quantitatively match with the force calculated by contact angle differences between the defect and the surface. The quantitative agreement even holds for defects reaching a size of $40\%$ of the drop diameter. Our validation for drop’s pinning forces at single defects is an important step towards a general understanding of contact line motion on heterogeneous surfaces

Dynamic multilevel modelling of industrial energy demand in Europe

Previous studies of industry level energy demand have not accounted for the hierarchical nesting of industries within a system that also adequately allows for country specific determinants of energy demand. The principal contribution of this paper is therefore to analyse energy demand for European industries over the period 1995–2009 using a dynamic multilevel model that accounts for this hierarchical data structure. Among other things, we find, firstly, that our dynamic multilevel model suggests that if industry income and the industry energy price increase by 10%, long run energy demand will increase by 8.1% and fall by 6.8%, respectively. Secondly, we find that the corresponding long run income and price elasticities are substantially larger in a standard dynamic model of industry level energy demand which does not account for the hierarchical data structure. Our results therefore suggest that not accounting for the hierarchical data structure results in unreliable estimates of energy demand elasticities. From a policy perspective we argue that it is imperative that future industry level energy demand studies account for the hierarchical structure of the data. This is to prevent energy policy making being based on industry level evidence that substantially inflates the responsiveness of long run energy demand to income and price changes

Multiplexing Stimulus Information through Rate and Temporal Codes in Primate Somatosensory Cortex

Our ability to perceive and discriminate textures relies on the transduction and processing of complex, high-frequency vibrations elicited in the fingertip as it is scanned across a surface. How naturalistic vibrations, and by extension texture, are encoded in the responses of neurons in primary somatosensory cortex (S1) is unknown. Combining single unit recordings in awake macaques and perceptual judgments obtained from human subjects, we show that vibratory amplitude is encoded in the strength of the response evoked in S1 neurons. In contrast, the frequency composition of the vibrations, up to 800 Hz, is not encoded in neuronal firing rates, but rather in the phase-locked responses of a subpopulation of neurons. Moreover, analysis of perceptual judgments suggests that spike timing not only conveys stimulus information but also shapes tactile perception. We conclude that information about the amplitude and frequency of natural vibrations is multiplexed at different time scales in S1, and encoded in the rate and temporal patterning of the response, respectively.</p

Small oscillations and the Heisenberg Lie algebra

The Adler Kostant Symes [A-K-S] scheme is used to describe mechanical systems for quadratic Hamiltonians of $\mathbb R^{2n}$ on coadjoint orbits of the Heisenberg Lie group. The coadjoint orbits are realized in a solvable Lie algebra $\mathfrak g$ that admits an ad-invariant metric. Its quadratic induces the Hamiltonian on the orbits, whose Hamiltonian system is equivalent to that one on $\mathbb R^{2n}$. This system is a Lax pair equation whose solution can be computed with help of the Adjoint representation. For a certain class of functions, the Poisson commutativity on the coadjoint orbits in $\mathfrak g$ is related to the commutativity of a family of derivations of the 2n+1-dimensional Heisenberg Lie algebra $\mathfrak h_n$. Therefore the complete integrability is related to the existence of an n-dimensional abelian subalgebra of certain derivations in $\mathfrak h_n$. For instance, the motion of n-uncoupled harmonic oscillators near an equilibrium position can be described with this setting.Comment: 17 pages, it contains a theory about small oscillations in terms of the AKS schem