Applying and Extending the Sustainable Value Method related to Agriculture – an Overview

Sustainable Value is a method to measure the contribution of an economic entity, such as a farm or the entire agricultural sector, towards the sustainability (sustainable development) of a region, a country or on a global scale. A positive sustainable value is created once resources are used more efficiently than by a benchmark. It shows the excess return that is created or lost by the use of economic, environmental and social resources by an economic entity relative to a benchmark. The purpose of this paper is to give an overview on the characteristics and requirements of the SV and to provide information on (a) possible applications and (b) extensions of the SV method related to the agricultural sector. A particular emphasis is put on the choice of sustainability indicators (resource figures, welfare figure) to be included, the generic steps of SV calculation, the meaning of weighting and aggregation in the SV, the role of the Return-to-Cost Ratio in taking farm size into consideration, and the interpretation and communication of the results of an agriculture-related SV assessment. After sketching out possible extensions and variations of the SV method, the paper closes with a summary of those aspects to keep in mind when applying the SV to agriculture.sustainability contributions, value, measurement, Environmental Economics and Policy,

Algunas observaciones sobre las oraciones condicionales

El cumplimiento de la condición expresada por la frase (1) Si Pedro viene, María se va. significa que María se va. Además parece que el incumplimiento de esta condición signifique que María no se va. Pero no es así. Si sería así, el texto (2) Si Pedro viene, María se va. Si Pedro no viene, ella se va también. fuese contradictorio, y no lo es, sin embargo. Además, es obvio que del incumplimiento de la condición de (3) Si esta es su foto, María es lindísima. no se puede deducir que María no sea lindísima. El cumplimiento o incumplimiento de la condición expresada por la subordinada de una oración condicional no tiene, pues, nada que ver con la afirmación o la negación de la principal.Facultad de Humanidades y Ciencias de la Educació

Reshaping Global Change Science for the 21st Century: Young Scientists’ Perspectives

Humanity is facing unprecedented environmental, social, and economic challenges. We ask what the role of the global science community should be in tackling these challenges. Increased awareness of the social context in which science is being produced; acceptance of the importance of controversy; and reflection around normative assumptions underlying research are needed. To help solve humanity’s grand challenges scientists need to move towards a transdisciplinary view of science where knowledge emerges from a collaborative environment and where young scientists are trained to work across disciplinary boundaries and engage with policy communities

Re-shaping Sustainability Science for the 21st Century: Young Scientists’ Perspectives

Humanity is facing unprecedented environmental, social and economic challenges. We ask what the role of the sustainability science community should be in tackling these challenges, focusing particularly on young scientists’ perspectives on the issue. On the basis of a questionnaire and a workshop with young scientists, we identify four major challenges facing humanity and develop three guidelines for sustainability science that seeks to address them. Results show that to help address humanity’s grand challenges, sustainability scientists need to move towards a trans-disciplinary system view of science and sustainability science problems. According to this view knowledge emerges from a collaborative and transdisciplinary environment and young scientists are trained to work across disciplinary boundaries and engage with policy communities

Electron-Phonon Scattering in Metallic Single-Walled Carbon Nanotubes

Electron scattering rates in metallic single-walled carbon nanotubes are studied using an atomic force microscope as an electrical probe. From the scaling of the resistance of the same nanotube with length in the low and high bias regimes, the mean free paths for both regimes are inferred. The observed scattering rates are consistent with calculations for acoustic phonon scattering at low biases and zone boundary/optical phonon scattering at high biases.Comment: 4 pages, 5 figure

Critical temperature and density of spin-flips in the anisotropic random field Ising model

We present analytical results for the strongly anisotropic random field Ising model, consisting of weakly interacting spin chains. We combine the mean-field treatment of interchain interactions with an analytical calculation of the average chain free energy (``chain mean-field'' approach). The free energy is found using a mapping on a Brownian motion model. We calculate the order parameter and give expressions for the critical random magnetic field strength below which the ground state exhibits long range order and for the critical temperature as a function of the random magnetic field strength. In the limit of vanishing interchain interactions, we obtain corrections to the zero-temperature estimate by Imry and Ma [Phys. Rev. Lett. 35, 1399 (1975)] of the ground state density of domain walls (spin-flips) in the one-dimensional random field Ising model. One of the problems to which our model has direct relevance is the lattice dimerization in disordered quasi-one-dimensional Peierls materials, such as the conjugated polymer trans-polyacetylene.Comment: 28 pages, revtex, 4 postscript figures, to appear in Phys. Rev.

Molecular dynamics symulation of hydrogen diffusion in palladium

In the present work, the diffusion of hydrogen atoms in the crystal lattice of palladium was investigated using the molecular dynamics. The diffusion coefficients, activation energies and preexponential factors were determined for structures with different hydrogen concentration. It is determined that the diffusion coefficients decrease and the activation energy of diffusion grows with increasing concentrations of hydrogen

Optimization of Immunoglobulin Substitution Therapy by a Stochastic Immune Response Model

Background: The immune system is a complex adaptive system of cells and molecules that are interwoven in a highly organized communication network. Primary immune deficiencies are disorders in which essential parts of the immune system are absent or do not function according to plan. X-linked agammaglobulinemia is a B-lymphocyte maturation disorder in which the production of immunoglobulin is prohibited by a genetic defect. Patients have to be put on life-long immunoglobulin substitution therapy in order to prevent recurrent and persistent opportunistic infections. Methodology: We formulate an immune response model in terms of stochastic differential equations and perform a systematic analysis of empirical therapy protocols that differ in the treatment frequency. The model accounts for the immunoglobulin reduction by natural degradation and by antigenic consumption, as well as for the periodic immunoglobulin replenishment that gives rise to an inhomogeneous distribution of immunoglobulin specificities in the shape space. Results are obtained from computer simulations and from analytical calculations within the framework of the Fokker-Planck formalism, which enables us to derive closed expressions for undetermined model parameters such as the infection clearance rate. Conclusions: We find that the critical value of the clearance rate, below which a chronic infection develops, is strongly dependent on the strength of fluctuations in the administered immunoglobulin dose per treatment and is an increasing function of the treatment frequency. The comparative analysis of therapy protocols with regard to the treatment frequency yields quantitative predictions of therapeutic relevance, where the choice of the optimal treatment frequency reveals a conflict of competing interests: In order to diminish immunomodulatory effects and to make good economic sense, therapeutic immunoglobulin levels should be kept close to physiological levels, implying high treatment frequencies. However, clearing infections without additional medication is more reliably achieved by substitution therapies with low treatment frequencies. Our immune response model predicts that the compromise solution of immunoglobulin substitution therapy has a treatment frequency in the range from one infusion per week to one infusion per two weeks