EC Visa Facilitation and Readmission Agreements: Implementing a New EU Security Approach in the Neighbourhood

With the Eastern Enlargement successfully completed, the EU is searching for a proper balance between internal security and external stabilisation that is acceptable to all sides. This paper focuses on an EU foreign policy instrument that is a case in point for this struggle: EC visa facilitation and readmission agreements. By looking at the EU's strategy on visa facilitation and readmission, this paper aims to offer a first systematic analysis of the objectives, substance and political implications of these agreements as a means to implement a new EU security approach in the neighbourhood. In offering more relaxed travel conditions in exchange for the signing of an EC readmission agreement and reforming domestic justice and home affairs, the EU has found a new way to press for reforms in neighbouring countries while addressing a major source of discontent in these countries. The analysis concludes with the broader implications of these agreements and argues that even if the facilitated travel opportunities are beneficial for the citizens of the target countries, the positive achievements are undermined by the Schengen enlargement, which makes the new member states tie up their borders to those of their neighbours.EU, EC visa facilitation, readmission agreements, European Neighbourhood Policy, Stabilisation and Association Process, Justice and Home Affairs

Total variation regularization of multi-material topology optimization

This work is concerned with the determination of the diffusion coefficient from distributed data of the state. This problem is related to homogenization theory on the one hand and to regularization theory on the other hand. An approach is proposed which involves total variation regularization combined with a suitably chosen cost functional that promotes the diffusion coefficient assuming prespecified values at each point of the domain. The main difficulty lies in the delicate functional-analytic structure of the resulting nondifferentiable optimization problem with pointwise constraints for functions of bounded variation, which makes the derivation of useful pointwise optimality conditions challenging. To cope with this difficulty, a novel reparametrization technique is introduced. Numerical examples using a regularized semismooth Newton method illustrate the structure of the obtained diffusion coefficient.

An Experimental Investigation of Perceived Differences in Personality and Leadership Attributes of Social Entrepreneurs Compared to for Profit Entrepreneurs and Non-Profit Organisations Leaders

Social enterprises (SEs) strive for the fulfilment of a social mission based on an elaborated income strategy. Consequently, they are largely conceptualised as hybrid enterprises combining logics of traditional non-profit organisations (NPOs) and for-profit enterprises (FPEs). This is sound on the organisational level; however, it remains unclear to which extent the perception of SE leaders on the personal level mirrors this hybridity as previous studies are limited in scope and methodology. Our work examines perceived personality traits, work-related values, leadership styles and leader attributes of SE leaders compared to FPE and NPO leaders. Using a vignette-based, comprehensive experimental design with a sample of business students (N = 170), we find that whereas notable differences in personality and leadership comparing SE and FPE leaders exist, SE and NPO leaders were perceived as not different. Based on our findings, theoretical and practical implications are discussed

Forecasting long memory time series under a break in persistence

We consider the problem of forecasting time series with long memory when the memory parameter is subject to a structural break. By means of a large-scale Monte Carlo study we show that ignoring such a change in persistence leads to substantially reduced forecasting precision. The strength of this effect depends on whether the memory parameter is increasing or decreasing over time. A comparison of six forecasting strategies allows us to conclude that pre-testing for a change in persistence is highly recommendable in our setting. In addition we provide an empirical example which underlines the importance of our findings

Optimal control of semilinear parabolic equations by BV-functions

Optimal control problems for semilinear parabolic equations with control costs involving the total bounded variation seminorm are analyzed. This choice of control cost favors optimal controls which are piecewise constant and it penalizes the number of jumps. It is an appropriate choice if a simple structure of the optimal controls is desired, which, however, is still sufficiently flexible so that good tracking properties can be maintained. Existence of optimal controls, necessary and sufficient optimality conditions, and sparsity properties of the derivatives are obtained. Convergence of a finite element approximation is analyzed and numerical examples illustrating structural properties of the optimal controls are provided.The work of the first author was supported by Spanish Ministerio de Economía y Competitividad under project MTM2014-57531-P. The work of the third author was supported by the Austrian Science Fund (FWF) under grant SFB F32 (SFB “Mathematical Optimization and Applications in Biomedical Sciences”)

“Digital In, Digital Out?“ – Evidence for a Curvilinear Relationship Between IT Experience in Top Management Teams and Firms’ Digital Orientation

To drive digital transformation, firms are increasingly adding IT-experienced executives to their top management team (TMT). Yet, whether IT-experienced executives can aid firms to achieve digital transformation remains unresolved theoretically and empirically. Drawing on human capital and group literature, we propose that there are limits to the benefits received from adding IT-experienced executives to a TMT, resulting in a curvilinear relationship between the share of IT-experienced executives in the TMT and a firm’s digital orientation. We also propose that this relationship is moderated by CEO entrepreneurial orientation and power concentration in the TMT. We test and find support for most of our hypotheses using a secondary panel data set comprising 1,855 firm-year observations from 256 firms listed in the S&P 500 between 2005 and 2017

Prebiotic Nucleoside Synthesis: The Selectivity of Simplicity

Ever since the discovery of nucleic acids 150 years ago, major achievements have been made in understanding and decrypting the fascinating scientific questions of the genetic code. However, the most fundamental question about the origin and the evolution of the genetic code remains a mystery. How did nature manage to build up such intriguingly complex molecules able to encode structure and function from simple building blocks? What conditions were required? How could the precursors survive the unhostile environment of early Earth? Over the past decades, promising synthetic concepts were proposed providing clarity in the field of prebiotic nucleic acid research. In this Minireview, we show the current status and various approaches to answer these fascinating questions

Molecular support for temporal dynamics of induced anti-herbivory defenses in the brown seaweed Fucus Vesiculosus

Grazing by the isopod Idotea baltica induces chemical defenses in the brown seaweed Fucus vesiculosus. A combination of a 33 day induction experiment, feeding choice assays and functional genomic analyses was used to investigate temporal defense patterns and to correlate changes in palatability to changes in gene expression. Despite permanent grazing, seaweed palatability varied over time. Controls were significantly more consumed than grazed pieces only after 18 and 27 days of grazing. Relative to controls, 562/402 genes were up-/down-regulated in seaweed pieces that were grazed for 18 days, i.e. when defense induction was detected. Reprogramming of the regulative expression orchestra (translation, transcription), up-regulation of genes involved in lipid and carbohydrate metabolism, intracellular trafficking, defense and stress response, as well as downregulation of photosynthesis was found in grazed seaweed. These findings indicate short-term temporal variation in defenses and that modified gene expression patterns arise at the same time when grazed seaweed pieces show reduced palatability. Several genes with putative defensive functions and cellular processes potentially involved in defence, such as reallocation of resources from primary to secondary metabolism, were reveale

A Research Program on Innovations in Prehistory and Antiquity

The authors discuss the simultaneous appearance of technological innovations in three key technologies (metallurgy, wheeled vehicles, weighing systems) in the second half of the 4th millennium. This is done from a source-critical perspective because the innova- tions are discussed with the help of dynamic maps from the Topoi project Digital Atlas of Innovations. Besides indications of diffusion gradients influenced by special research conditions, exceptional waves of innovation can be detected for all three technologies in the discussed period. These waves of innovation cannot, however, be generalized but have to be understood on the basis of the respective technology traditions and lines of devel- opment specific to local areas. Monocentric diffusion theories can be clearly disproven, local technology developments and their converging in certain centrally situated regions have to be assumed instead. Similarly, the transfer of objects and their châine opératoire can only be detected rather infrequently, while the adaptation to local socio-economic and environmental factors can be demonstrated