Universität Kassel
  • Kassel, Hessen, Germany
Recent publications
Das Handbuch Organisationssoziologie liefert einen umfassenden Überblick über die Entwicklung, den Stand und die Zukunft der Organisationssoziologie als wissenschaftliche Disziplin. Dabei geht es sowohl um die systematische Aufnahme relevanter Theoriestränge, Methoden und Konzepte als auch um die Wechselbeziehungen, Überschneidungen und Komplementaritäten zu Nachbardisziplinen, die in einem Dialog aufgenommen werden. Das Handbuch vermittelt so einen eigenständigen Zugriff auf die Organisationssoziologie und bündelt gleichzeitig dessen Wissen auf dem neuesten Stand. Darüber soll es zu einem Standardwerk zur Organisationssoziologie im deutschsprachigen Raum werden.
In his writings, Gibson firmly claimed that cultural or social factors could never distort perception. Cultural artefacts, social norms, language and signs were instead described as influencing perception and behavior only indirectly. At the same time, in his last monumental monograph, Gibson introduced the concept of affordance as applicable to the “whole realm of social significance”. Unfortunately, Gibson did not elaborate further on the relationship between the notion of affordance and the socio-cultural organization of niches like ours. This issue divided Gibson’s followers into two sides. Some of them followed Gibson, claiming that socio-cultural factors can drive behavior but never permeate perceptual experience to its bottom layers. A second group assumes instead that the presence of a structured socio-cultural context permeates the meaning of affordances already at the perceptual level. The aim of this chapter is twofold. The first part of the chapter aims to reconstruct Gibson’s view on the role of culture and sociality and then highlight the reasoning that animates both groups of theorists. In particular, a large part of the discussion is based on motivating the problematics that led the second group of theorists to disagree with Gibson and his idea that the individual’s social background never permeates sensory perception. The second aim is to throw the seeds to develop a methodological tool available to these theorists in order to characterize the experience of affordances as shaped by the social and cultural context in which they are embedded; the notion of field. This notion has a long history in psychology but its methodological consequences are often overlooked. Notably, one of the risks of the concept of field is, as scholars of the Gestalt school like Parlett and Lee claimed, that the notion could be framed so broadly to include “anything and everything”, making it theoretically and scientifically trivial and hence unable to provide a rigorous characterization of what is encountered in individual experiences. To avoid the trivialization of this concept, I conclude by developing a recent proposal that suggests endorsing the notion of field specifically elaborated by the phenomenologist Aron Gurwitsch.
The 4E approaches have been frequently linked to the claim that they fundamentally change how we theoretically analyze and empirically investigate cognitive phenomena. Despite this aspiration, the methodology of 4E researchers received surprisingly little attention, although the envisaged change of mainstream cognitive studies presupposes elaborated methodical competencies. This chapter argues that a methodology is necessary for the 4Es. However, several preliminary considerations need to precede a methodological analysis of the branch. It is claimed that methodological analyses of 4E research first need to answer the problem of choice whether to support a version of explanatory pluralism or explanatory unification. The answer to this problem significantly influences how a methodology can be developed. The problem can only be properly met, however, if the different versions of pluralist and unificationist positions are related so that we can understand where exactly they diverge or overlap. Below, the spectrum of integration is introduced, which suggests a relation between pluralist and unificationist views. The spectrum is a provisional guide to a 4E methodology as it invites 4E researchers to place themselves within this spectrum and approach methodological and methodical questions from there.
Chapter 2 and Chapter 4, Casper’s “A Methodological Problem of Choice for 4E Research” and Sanches de Oliveira’s “Explanatory Diversity and Embodied Cognitive Science: Reflexivity Motivates Pluralism”, seem to address the same issue: the plurality of methods in the 4E debate. On the one hand, my contribution considers this plurality a severe challenge for 4E researchers and their future studies – since it implies the question of whether and how different methodical approaches and their results can connect on an interdisciplinary level. Sanches de Oliveira, on the other hand, intends to offer a description of this plurality under which such problems disappear. In this comment I point out four problematic aspects of his account.
Methods for evaluating the orientation of carbon fibers in reinforced plastics vary in complexity and are application specific. Here, we report an algorithm that quickly evaluates in-plane fiber orientation based on determining the correlation coefficient of adjacent regions in microscopy images. The result is not the fiber orientation of individual fibers, but the principal fiber orientation of small image areas. This method is applicable to large areas due to its low computation time and captures varying fiber orientations, making it suitable for the study of injection molded samples with complex geometries. A great advantage is that no information about the fibers or the matrix, or their combination, is needed prior to the analysis. This approach is also suitable for samples with surface defects. Demonstrations of this technique are given for Polyamide 6 and Polypropylene with 30 weight % carbon fibers of different fiber lengths.
Meta-analyses of treatment effects in randomized control trials are often faced with the problem of missing information required to calculate effect sizes and their sampling variances. Particularly, correlations between pre-and posttest scores are frequently not available. As an ad-hoc solution, researchers impute a constant value for the missing correlation. As an alternative, we propose adopting a multivariate meta-regression approach that models independent group effect sizes and accounts for the dependency structure using robust variance estimation or three-level modeling. A comprehensive simulation study mimicking realistic conditions of meta-analyses in clinical and educational psychology suggested that imputing a fixed correlation 0.8 or adopting a multi-variate meta-regression with robust variance estimation work well for estimating the pooled effect but lead to slightly distorted between-study heterogeneity estimates. In contrast, three-level meta-regressions resulted in largely unbiased fixed effects but more inconsistent prediction intervals. Based on these results recommendations for meta-analytic practice and future meta-analytic developments are provided.
This chapter takes a holistic look at social justice leadership practices and the education of refugee students in Turkish context. Building on Bronfenbrenner’s ecological systems theory, we elaborate on multiple and interwoven dynamics shaping and influencing the schooling of refugee-background students. From the school ecology to the national education policies, this study maps the terrain of social justice leadership in Turkey by depicting the practices, actions, and initiatives utilized to overcome the challenges and barriers faced in creating socially just schools and supportive communities. This study contributes to the scholarship and understanding of social justice leadership by providing a multi-level approach for both educational researchers, practitioners and school leaders in examining the phenomenon.
Analysts have long advocated a linkage between international cooperation on climate change and trade measures, such as border tariffs, as a means of enforcing agreements to achieve deeper cooperation. Nevertheless, it has remained difficult to evaluate whether policy makers will allow such linkages and whether linking climate and trade would, in reality, yield beneficial effects to international cooperation. Working with a large sample of climate experts who are highly experienced in climate diplomacy and policy, we elicited how they view the legitimacy and usefulness of linking trade and climate and what factors can explain those views. We find that experts from richer countries, especially Europe, are more likely to see linkage as legitimate and effective. These experts are particularly likely to favor universal border adjustments (UBAs) that apply to all countries to level the economic playing field, rather than trade measures that define an exclusive “club” of countries making extra efforts to cut emissions while punishing non-club members. This finding reveals tensions between a shift in academic thinking about the value of club-based strategies—including clubs that use border measures for enforcement—and what climate policy experts see as valuable. European experts are particularly likely to favor UBAs and they are also least likely to see risks in implementing trade measures. In general, countries with high quality national institutions see lower risks in using trade measures to enforce greater cooperation on climate change. A particularly robust finding is that experts who perceive their home country’s emissions reduction pledge as ambitious are more likely to see risks from using trade measures. While these are the countries that could benefit the most from using trade measures, they are also the countries that are offering the most under the existing Paris Agreement. Experts seem to be increasingly aware of the dissonance between the voluntarism of the Paris Agreement and growing political pressures to apply trade measures. We also find the attributes of experts, such as training and career experience, can affect their assessments. In some models, experts with economic or business backgrounds are more likely to favor trade measures while those with careers in natural science, diplomacy, and national government are less sanguine. Our results suggest that diverging views on the need for trade-based enforcement are robust, associated with important attributes of countries such as their commitments, and likely to persist—suggesting that policy strategies favoring the use of trade measures must pay close attention to the conditions that will determine where and how trade measures can be implemented. Experts from many countries that are the biggest supporters of the Paris approach to climate cooperation also doubt the legitimacy of trade measures.
Surgical Smoke is generated during the cauterization of tissue with high-frequency (HF) devices and consists of 95% water vapor and 5% cellular debris. When the coagulation tweezers, which are supplied with HF voltage by the HF device, touch tissue, the electric circuit is closed, and smoke is generated by the heat. In-vivo investigations are performed during tracheotomies where surgical smoke is produced during coagulation of tissue. Furthermore, in-vitro parametric studies to investigate the particle number and size distribution and the spatial distribution of surgical smoke with laser light sheet technique are conducted. With higher power of the HF device, the particles generated are larger in size and the total number of particles generated is also higher. Adding artificial saliva to the tissue shows even higher particle counts. The study by laser light sheet also confirms this. The resulting characteristic size distribution, which may include viruses and bacterial components, confirms considering the risk arising from surgical smoke. Furthermore, the experiments will provide the database for further numerical investigations.
In phase change simulations, material properties such as density, viscosity, or thermal conductivity may exhibit jump discontinuities, possibly of several orders of magnitude. These jump discontinuities represent interfaces between the phases, and they emerge naturally during the simulation; thus, their exact location is generally unknown a priori. Our goal is to simulate phase change processes with a meshfree generalized finite difference method in a monolithic model without distinguishing between the different phases. There, the material properties mentioned above appear as coefficients inside elliptic operators in divergence form and the jumps must be treated adequately by the numerical method. We present a numerical method for discretizing elliptic operators with discontinuous coefficients without the need for a domain decomposition or tracking of interfaces. Our method facilitates the construction of diagonally dominant diffusion operators that lead to M‐matrices for the discrete Poisson's equation, and thus, satisfy the discrete maximum principle. We demonstrate the applicability of the new method for the case of smooth diffusivity and discontinuous diffusivity. We show that the method is first‐order accurate for discontinuous diffusion problems and provides second‐order and fourth‐order convergence for continuous diffusion coefficients.
The autosomal recessive diphthamide deficiency syndrome presents as intellectual disability with developmental abnormalities, seizures, craniofacial and additional morphological phenotypes. It is caused by reduced activity of proteins that synthesize diphthamide on human translation elongation factor 2. Diphthamide synthesis requires seven proteins (DPH1-DPH7) with clinical deficiency described for DPH1, DPH2 and DPH5. So far, just a limited set of variant alleles from syndromic patients were functionally analyzed, but databases (gnomAD) list additional so far uncharacterized mutations of human DPH1 and DPH2. Because DPH enzymes are conserved among eukaryotes, their functionality can be assessed in yeast and mammalian cells. Our experimental assessment of known and so far uncharacterized DPH1 and DPH2 missense alleles showed that six mutations are tolerated despite of inter-species conservation. 10 additional human DPH1 (G113R, A114T, H132P, H132R, S136R, C137F, L138P, Y152C, S221P, H240R) and two DPH2 variants (H105P, C341Y) showed reduced functionality and are hence deficiency-susceptibility alleles. Structure models indicate that some variants locate close to the active centers of the enzymes (may directly affect catalysis), others more distant (possibly relevant for electron transfer mediated enzyme activation).
Reforestation after forest clearcutting is an effective measure to increase soil organic carbon (SOC) sequestration. However, the soil C balance and functions of microbial communities under reforestation remain to be determined. Samples of organic (0-2 cm) and mineral (2-10 cm) horizons were collected from the 7-, 15-, 20-, 29-, and 36-year-old forest stands of Chinese fir developed after plantation clearcutting in subtropical climate zone under the condition of phosphorus limitation. Particulate organic carbon (POC), mineral-associated organic carbon (MAOC), microbial phospholipid fatty acids (PLFAs), and enzymatic activities for C, nitrogen (N), and phosphorus (P) acquisition were analyzed. The lowest contents of POC (10 %) and MAOC (13 %) in the organic horizon were found in 7-year-old stands due to the slow tree regrowth and extensive decomposition of SOC in the first years of forest regrowth. POC (2.0x) and MAOC (0.8x) increases in the organic horizon with forest age were attributed to the stand development and accumulation of above and belowground litter. The organic horizon had a higher POC: MAOC ratio than the mineral (0.7-1.1 vs. 0.2-0.5), indicating lower SOC stability in the first one. A positive correlation of the Gram-positive to Gram-negative bacteria (G+:G-) ratio with the POC: MAOC ratio may point to developing specific substrate utilization strategies for microbial communities. Microorganisms were limited by C and P; however, the C limitation was alleviated in the 36-year-old plots in the organic horizon due to increased litter input. Microbial C and P limitations increased with total PLFAs and the G+:G- ratio, indicating the strong influence of community structure on nutrient acquisition from SOC. Thus, soil C sequestration under reforestation of Chinese fir can be controlled by microbial community structure and metabolic limitation, which both shifted with the stand age.
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Arno Ehresmann
  • Institute of Physics
Ossama Kullie
  • Natural Sciece/Theoretical Physics
Mönchebergstraße 19, 34109, Kassel, Hessen, Germany
Head of institution
Prof. Dr. Reiner Finkeldey
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