Fear or freedom? Visually impaired students’ ambivalent perspectives on physical education

With a growing interest in sport, fitness, and a healthy lifestyle, bodily practices are increasing in importance in our society. In the school context, physical education (PE) is the subject where these practices play a central role. But, the German language discourse shows in an exemplary manner that inherent body-related social normality requirements are articulated in didactic traditions and curricular requirements, and that these normality requirements have exclusionary potential for those students who do not fit into the norms. Against this background, this article seeks to understand children with visual impairments’ (CWVI’s) individual constructions of PE in a school specialized for CWVI in Germany. This interview study with eight CWVI focused on individual opportunities and challenges concerning central aspects in PE. The findings show that the CWVI draw ambivalent perspectives on PE that range from existential fears (e.g., fears of heights) to feeling free in working off energy. These aspects especially gain importance in connection to the body, when the general wish to learn and experience with the body seems to be disturbed by normality requirements – like doing certain movements in a pre-defined way – which lead to existential challenges for the CWVI. Further, the relationship between blind and visually impaired students in PE seems ambivalent. Within this special school setting, the segregation according to the external differentiation in “handicapped” and “non-handicapped” somehow leads to a kind of subsegregation at the blind and visually impaired school.Peer Reviewe

Barriers and Challenges for Visually Impaired Students in PE - An Interview Study With Students in Austria, Germany, and the USA

Physical education (PE) is an important part of school education worldwide, and at the same time, almost the only subject that explicitly deals with body and movement. PE is therefore of elementary importance in the upbringing of young people. This also applies to children with visual impairments. However, existing findings on participation and belonging in PE as well as on physical and motor development reveal that this group of children and adolescents is noticeably disadvantaged in this respect. Against this background, this paper aims to explore fundamental barriers and challenges across different types of schools, types of schooling, and countries from the perspective of visually impaired children. The qualitative interview study with 22 children with visual impairments at different types of schools in three countries (Austria, Germany, USA) reveals that none of the respondents could escape the power of social distinctions and related problematic and existing hierarchies. Hence, ideas of normality and associated values remain the main challenge for all of them. However, the type-forming analysis provides important insight across settings on how visually impaired children differ on this, allowing for greater sensitivity to the concerns of children with visual impairments

...And After That Came Me . Subjective Constructions of Social Hierarchy in Physical Education Classes Among Youth with Visual Impairments in Germany

The aim of this study was to reconstruct subjective constructions of experiences in PE and feelings of being valued within PE classes in Germany by students with visual impairment (VI). Two female and two male students (average age: 19.25 years) participated in the study from the upper level. For the reconstruction of experiences of feeling valued, episodic interviews with a semi-structured interview guide were used. The data analysis was conducted with MAXQDA 2020 based on content-related structuring of qualitative text analysis with deductive-inductive category formation. To structure the analysis, the main category, feelings of being valued, was defined by two poles (positive feelings of being valued as opposed to bullying). As a main finding, respondents primarily reported negative feelings and experiences characterized by instances of bullying, discrimination, and physical and social isolation, perpetuated by both their peers and teachers. In search of a deeper understanding, we identified social hierarchy as an underlying structure determining the students\u27 perceived positioning within the social context and thus directing their feelings of being (de-)valued. It became evident that it is not the setting per se that determined social hierarchy, but that it is more about the concrete manifestation of social hierarchy

Influence of cell shape, inhomogeneities and diffusion barriers in cell polarization models

In silico experiments bear the potential to further the understanding of biological transport processes by allowing a systematic modification of any spatial property and providing immediate simulation results for the chosen models. We consider cell polarization and spatial reorganization of membrane proteins which are fundamental for cell division, chemotaxis and morphogenesis. Our computational study is motivated by mating and budding processes of S. cerevisiae. In these processes a key player during the initial phase of polarization is the GTPase Cdc42 which occurs in an active membrane-bound form and an inactive cytosolic form. We use partial differential equations to describe the membrane-cytosol shuttling of Cdc42 during budding as well as mating of yeast. The membrane is modeled as a thin layer that only allows lateral diffusion and the cytosol is modeled as a volume. We investigate how cell shape and diffusion barriers like septin structures or bud scars influence Cdc42 cluster formation and subsequent polarization of the yeast cell. Since the details of the binding kinetics of cytosolic proteins to the membrane are still controversial, we employ two conceptual models which assume different binding kinetics. An extensive set of in silico experiments with different modeling hypotheses illustrate the qualitative dependence of cell polarization on local membrane curvature, cell size and inhomogeneities on the membrane and in the cytosol. We examine that spatial inhomogenities essentially determine the location of Cdc42 cluster formation and spatial properties are crucial for the realistic description of the polarization process in cells. In particular, our computer simulations suggest that diffusion barriers are essential for the yeast cell to grow a protrusion

Additive Manufacturing and Vulcanization of Carbon Black Filled Natural Rubber Based Components

Additive manufacturing of thermoplastics or metals is a well-approved sustainable process for obtaining rapidly precise and individual technical components. Except for crosslinked silicone rubber or thermoplastic elastomers, there is no method of additive manufacturing of elastomers. Based on the development of the additive manufacturing of elastomers (AME) process, the material group of rubber-based cured elastomers may gain first access to the process field of three-dimensional (3D) printing. Printing and crosslinking of rubber is separated into two steps. In the first step, printing is realized by extrusion of the rubber by using a twin-screw extruder, which works according to the derived fused-filament-fabrication principle. In the second step, the component is vulcanized in a high-pressure hot-air autoclave. Because of the plastic flow behavior of non–crosslinked rubber materials, a thermoplastic shell is probably needed to maintain the geometry and position of the additively manufactured rubber. In this way, one layer of thermoplastic and one layer of rubber are printed alternatingly until the component is finished. Afterward, the manufactured binary component is placed in an autoclave to obtain the elastomer after vulcanization under a hot-air and high-pressure atmosphere. Then, the thermoplastic shell is removed from the elastomer and can subsequently be recycled. As compared with conventional thermoplastics, the high viscosity of rubber during processing and its instable shape after extrusion are challenging factors in the development of the AME. This contribution will show a modified 3D printer; explain the printing process from the designed component, via shell generation, to the vulcanized component; and show first printed components

Modelling Ser129 Phosphorylation Inhibits Membrane Binding of Pore-Forming Alpha-Synuclein Oligomers

Background: In several neurodegenerative diseases, hyperphosphorylation at position Ser129 is found in fibrillar deposits of alpha-synuclein (asyn), implying a pathophysiological role of asyn phosphorylation in neurodegeneration. However, recent animal models applying asyn phosphorylation mimics demonstrated a protective effect of phosphorylation. Since metal-ion induced asyn oligomers were identified as a potential neurotoxic aggregate species with membrane pore-forming abilities, the current study was undertaken to determine effects of asyn phosphorylation on oligomer membrane binding. Methods: We investigated the influence of S129 phosphorylation on interactions of metal-ion induced asyn oligomers with small unilamellar lipid vesicles (SUV) composed of POPC and DPPC applying the phosphorylation mimic asyn129E. Confocal single-particle fluorescence techniques were used to monitor membrane binding at the single-particle level. Results: Binding of asyn129E monomers to gel-state membranes (DPPC-SUV) is slightly reduced compared to wild-type asyn, while no interactions with membranes in the liquid-crystalline state (POPC-SUV) are seen for both asyn and asyn129E. Conversely, metal-ion induced oligomer formation is markedly increased in asyn129E. Surprisingly, membrane binding to POPC-SUV is nearly absent in Fe3+ induced asyn129E oligomers and markedly reduced in Al3+ induced oligomers. Conclusion: The protective effect of pseudophosphorylation seen in animal models may be due to impeded oligomer membrane binding. Phosphorylation at Ser129 may thus have a protective effect against neurotoxic asyn oligomers by preventing oligomer membrane binding and disruption of the cellular electrophysiological equilibrium. Importantly, these findings put a new complexion on experimental pharmaceutical interventions against POLO-2 kinase

Motor skill learning depends on protein synthesis in the dorsal striatum after training

Functional imaging studies in humans and electrophysiological data in animals suggest that corticostriatal circuits undergo plastic modifications during motor skill learning. In motor cortex and hippocampus circuit plasticity can be prevented by protein synthesis inhibition (PSI) which can interfere with certain forms learning. Here, the hypothesis was tested that inducing PSI in the dorsal striatum by bilateral intrastriatal injection of anisomycin (ANI) in rats interferes with learning a precision forelimb reaching task. Injecting ANI shortly after training on days 1 and 2 during 4days of daily practice (n=14) led to a significant impairment of motor skill learning as compared with vehicle-injected controls (n=15, P=0.033). ANI did not affect the animals' motivation as measured by intertrial latencies. Also, ANI did not affect reaching performance once learning was completed and performance reached a plateau. These findings demonstrate that PSI in the dorsal striatum after training impairs the acquisition of a novel motor skill. The results support the notion that plasticity in basal ganglia circuits, mediated by protein synthesis, contributes to motor skill learnin