On correlation between protein secondary structure, backbone bond angles, and side-chain orientations

We investigate the fine structure of the sp3 hybridized covalent bond geometry that governs the tetrahedral architecture around the central C$_\alpha$ carbon of a protein backbone, and for this we develop new visualization techniques to analyze high resolution X-ray structures in Protein Data Bank. We observe that there is a correlation between the deformations of the ideal tetrahedral symmetry and the local secondary structure of the protein. We propose a universal coarse grained energy function to describe the ensuing side-chain geometry in terms of the C$_\beta$ carbon orientations. The energy function can model the side-chain geometry with a sub-atomic precision. As an example we construct the C$_\alpha$-C$_\beta$ structure of HP35 chicken villin headpiece. We obtain a configuration that deviates less than 0.4 \.A in root-mean-square distance from the experimental X-ray structure

How to understand and handle divergent views on the need for leadership interventions: a social constructionist approach

This paper addresses the challenge of how to understand and handle divergent views on the need for leadership interventions between managers and subordinates. Recent popular discourses of leadership, such as the authentic leadership perspective, privileges the potential leader himself or herself as the origin of leadership. This perspective thereby neglects the view of the followers and the essentially socially constructed relationship between leaders and followers. Based upon a critique against essentialist views of leadership such as authentic leadership we suggest a model on how to analyse divergent views between leaders and followers and its implications regarding managerial discretion regarding leadership initiatives

Alternative food networks in food system transition—values, motivation, and capacity building among young Swedish market gardeners

This study sheds light on a new generation of Swedish food producers, market gardeners, who are attracting attention in terms of food system sustainability, prompted by increasing consumer awareness about the value of healthy and locally produced food. Market gardening is part of a global agroecological movement opposed to industrialized agriculture and its negative impacts on the environment and rural communities. These food producers challenge the incumbent agri-food regime through the building of alternative food networks. This case-based study involving 14 young vegetable producers showed that young people who engage in market gardening are strongly motivated by dual incentives, namely entrepreneurship and transformation to sustainability. Six main competences were identified as important for market gardeners: practical skills related to growing vegetables, business management, innovation and continuous learning, systems thinking, pioneering, and networking. Individuals develop their skills through continuous experiential learning and gain knowledge through peer-to-peer learning using social media. However, they need to acquire certain skills relating to their daily work in the field and to managing a business. Market gardeners currently face a number of barriers erected by the sociopolitical environment, in particular regarding access to research-based knowledge, extension services, and business support

Elastic Energy and Phase Structure in a Continuous Spin Ising Chain with Applications to the Protein Folding Problem

We present a numerical Monte Carlo analysis of a continuos spin Ising chain that can describe the statistical proterties of folded proteins. We find that depending on the value of the Metropolis temperature, the model displays the three known nontrivial phases of polymers: At low temperatures the model is in a collapsed phase, at medium temperatures it is in a random walk phase, and at high temperatures it enters the self-avoiding random walk phase. By investigating the temperature dependence of the specific energy we confirm that the transition between the collapsed phase and the random walk phase is a phase transition, while the random walk phase and self-avoiding random walk phase are separated from each other by a cross-over transition. We also compare the predictions of the model to a phenomenological elastic energy formula, proposed by Huang and Lei to describe folded proteins.Comment: 12 pages, 23 figures, RevTeX 4.