Bio Suisse Bans Hybrid Cereals

On April 19th, 2006, the 100 delegates of Bio Suisse, the Swiss organic umbrella organization, voted to ban Hybrid varieties in organic cereals (except maize). This decision primarily concerns rye. Organic rye is grown on only 250 ha, about 20% of which is sown to hybrid varieties at present. About 60% of total organic demand is imported. Hybrid varieties of the other cereals are not yet being grown. The delegates decided that it is time to act now to send a signal to breeders and to the international organic community before the alternatives to hybrids vanish

Nitrate Contamination of Groundwater: Determinants and Indicators

Nitrogen is an important input to agricultural production but also detrimentally affects the environmental quality of air, soil and water. Identifying the determinants of nitrate pollution and in turn defining sensible performance indicators to design, enforce and monitor regulatory policies is therefore of utmost importance. Using data on more than 1000 Austrian municipalities, we provide a detailed econometric analysis of (1) the determinants of nitrate concentration in groundwater, and (2) the predictive abilities of one of the most commonly used agri-environmental indicators, the Nitrogen Balance. We find that the proportion of cropland exerts a positive effect on the nitrate content in groundwater. Additionally, environmental factors such as temperature and precipitation are found to be important. Higher average temperature leads to lower nitrate pollution of groundwater possibly due to increased evapotranspiration. Equally, higher average precipitation dilutes nitrate content in the soil, reducing nitrate concentration in groundwater. To assess the Nitrogen Balance, we link observed pollution levels to the theoretical indicator and evaluate its ability to measure nitrate pollution effects. Indeed, the indicator proves to be a good predictor for nitrate pollution. We also show that its predictive power can be improved if average precipitation of a region is taken into account. If average precipitation is higher, the Nitrogen Balance predicts nitrate levels in groundwater more precisely.nitrate concentration, groundwater, Nitrogen Balance, agriculture, regression analysis., Agricultural and Food Policy, Crop Production/Industries, Environmental Economics and Policy, Farm Management, Land Economics/Use, Production Economics,

Generalization of polynomial chaos for estimation of angular random variables

“The state of a dynamical system will rarely be known perfectly, requiring the variable elements in the state to become random variables. More accurate estimation of the uncertainty in the random variable results in a better understanding of how the random variable will behave at future points in time. Many methods exist for representing a random variable within a system including a polynomial chaos expansion (PCE), which expresses a random variable as a linear combination of basis polynomials. Polynomial chaos expansions have been studied at length for the joint estimation of states that are purely translational (i.e. described in Cartesian space); however, many dynamical systems also include non-translational states, such as angles. Many methods of quantifying the uncertainty in a random variable are not capable of representing angular random variables on the unit circle and instead rely on projections onto a tangent line. Any element of any space V can be quantified with a PCE if V is spanned by the expansion’s basis polynomials. This implies that, as long as basis polynomials span the unit circle, an angular random variable (either real or complex) can be quantified using a PCE. A generalization of the PCE is developed allowing for the representation of complex valued random variables, which includes complex representations of angles. Additionally, it is proposed that real valued polynomials that are orthogonal with respect to measures on the real valued unit circle can be used as basis polynomials in a chaos expansion, which reduces the additional numerical burden imposed by complex valued polynomials. Both complex and real unit circle PCEs are shown to accurately estimate angular random variables in independent and correlated multivariate dynamical systems”--Abstract, page iii

Computational studies of biomembrane systems: Theoretical considerations, simulation models, and applications

This chapter summarizes several approaches combining theory, simulation and experiment that aim for a better understanding of phenomena in lipid bilayers and membrane protein systems, covering topics such as lipid rafts, membrane mediated interactions, attraction between transmembrane proteins, and aggregation in biomembranes leading to large superstructures such as the light harvesting complex of green plants. After a general overview of theoretical considerations and continuum theory of lipid membranes we introduce different options for simulations of biomembrane systems, addressing questions such as: What can be learned from generic models? When is it expedient to go beyond them? And what are the merits and challenges for systematic coarse graining and quasi-atomistic coarse grained models that ensure a certain chemical specificity

Wulf Hopf: Freiheit - Leistung - Ungleichheit. Bildung und soziale Herkunft in Deutschland. Weinheim/München: Juventa 2010 [Rezension]

Rezension von: Wulf Hopf: Freiheit – Leistung - Ungleichheit. Bildung und soziale Herkunft in Deutschland. Weinheim/München: Juventa 201

An Open Model for Researching the Role of Culture in Online Self-Disclosure

The analysis of consumers’ personal information (PI) is a significant source to learn about consumers. In online settings, many consumers disclose PI abundantly - this is particularly true for information provided on social network services. Still, people manage the privacy level they want to maintain by disclosing by disclosing PI accordingly. In addition, studies have shown that consumers’ online self-disclosure (OSD) differs across cultures. Therefore, intelligent systems should consider cultural issues when collecting, processing, storing or protecting data from consumers. However, existing studies typically rely on a comparison of two cultures, providing valuable insights but not drawing a comprehensive picture. We introduce an open research model for cultural OSD research, based on the privacy calculus theory. Our open research model incorporates six cultural dimensions, six predictors, and 24 structured propositions. It represents a comprehensive approach that provides a basis to explain possible cultural OSD phenomena in a systematic way

Ethnography in Health Services Research: Oscillation Between Theory and Practice

The well-known divergence between what policy and protocol look like on paper, and what happens in the actual practice of daily life remains a central challenge in health services provision and research. This disparity is usually referred to as the theory–practice gap and contributes to concerns that scientific evidence fails to make substantial impacts on the processes of service delivery. In this article, we present an argument for the inclusion of ethnographic methods in health services research and show that this approach enables researchers to address this divergence by working within it. We trace how ethnography, through generative processes of oscillation, can take us beyond lamenting the gap and capture the relational dynamics of people working together in complex systemic arrangements. By moving from example to methodological reflection, to principle of research, we demonstrate how the oscillation of ethnographic research between theory and practice can productively contribute to the field of health service research

Rezension des Buches Bildungskarrieren von Jugendlichen und ihre Peers an exklusiven Schulen, von Heinz-Hermann Krüger, Catharina Keßler und Daniela Winter

[Rezension des Buches Bildungskarrieren von Jugendlichen und ihre Peers an exklusiven Schulen, von Heinz-Hermann Krüger, Catharina Keßler und Daniela Winter.