1. |
- Amirian, Benhour, et al.
(author)
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Thermodynamically-consistent derivation and computation of twinning and fracture in brittle materials by means of phase-field approaches in the finite element method
- 2022
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In: International Journal of Solids and Structures. - : Elsevier. - 0020-7683 .- 1879-2146. ; 252
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Journal article (peer-reviewed)abstract
- A theoretical-computational framework is proposed for predicting the failure behavior of two anisotropic brittle materials, namely, single crystal magnesium and boron carbide. Constitutive equations are derived, in both small and large deformations, by using thermodynamics in order to establish a fully coupled and transient twin and crack system. To study the common deformation mechanisms (e.g., twinning and fracture), which can be caused by extreme mechanical loading, a monolithically-solved Ginzburg–Landau-based phase-field theory coupled with the mechanical equilibrium equation is implemented in a finite element simulation framework for the following problems: (i) twin evolution in two-dimensional single crystal magnesium and boron carbide under simple shear deformation; (ii) crack-induced twinning for magnesium under pure mode I and mode II loading; and (iii) study of fracture in homogeneous single crystal boron carbide under biaxial compressive loading. The results are verified by a steady-state phase-field approach and validated by available experimental data in the literature. The success of this computational method relies on using two distinct phase-field (order) parameters related to fracture and twinning. A finite element method-based code is developed within the Python-based open-source platform FEniCS. We make the code publicly available and the developed algorithm may be extended for the study of phase transformations under dynamic loading or thermally-activated mechanisms, where the competition between various deformation mechanisms is accounted for within the current comprehensive modeling approach.
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2. |
- Amirian, E. Susan, et al.
(author)
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Approaching a Scientific Consensus on the Association between Allergies and Glioma Risk : a report from the Glioma International Case-Control Study
- 2016
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In: Cancer Epidemiology, Biomarkers and Prevention. - : American Association for Cancer Research. - 1055-9965 .- 1538-7755. ; 25:2, s. 282-290
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Journal article (peer-reviewed)abstract
- Background: Several previous studies have found inverse associations between glioma susceptibility and a history of allergies or other atopic conditions. Some evidence indicates that respiratory allergies are likely to be particularly relevant with regard to glioma risk. Using data from the Glioma International Case-Control Study (GICC), we examined the effects of respiratory allergies and other atopic conditions on glioma risk. Methods: The GICC contains detailed information on history of atopic conditions for 4,533 cases and 4,171 controls, recruited from 14 study sites across five countries. Using two-stage random-effects restricted maximum likelihood modeling to calculate meta-analysis ORs, we examined the associations between glioma and allergy status, respiratory allergy status, asthma, and eczema. Results: Having a history of respiratory allergies was associated with an approximately 30% lower glioma risk, compared with not having respiratory allergies (mOR, 0.72; 95% confidence interval, 0.58-0.90). This association was similar when restricting to high-grade glioma cases. Asthma and eczema were also significantly protective against glioma. Conclusion: A substantial amount of data on the inverse association between atopic conditions and glioma has accumulated, and findings from the GICC study further strengthen the existing evidence that the relationship between atopy and glioma is unlikely to be coincidental. Impact: As the literature approaches a consensus on the impact of allergies in glioma risk, future research can begin to shift focus to what the underlying biologic mechanism behind this association may be, which could, in turn, yield new opportunities for immunotherapy or cancer prevention. (C) 2016 AACR.
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3. |
- Atã, Pedro, PhD candidate, 1990-, et al.
(author)
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O externalismo semiótico ativo de C. S. Peirce e a cantoria de viola como signo em ação : The active semiotic externalism of C. S. Peirce and the "Cantoria de viola" as a sign in action
- 2021
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In: Trans/Form/Ação. - : Universidade Estadual Paulista, Departamento de Filosofia. - 0101-3173 .- 1980-539X. ; 44:3, s. 177-204
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Journal article (peer-reviewed)abstract
- The main purpose of this work is to provide a semiotic ontology for redescription of active cognitive externalism, recently developed by the paradigm 4E (embodied, embedded, enactive, extended cognition). In our approach, distributed cognitive systems (DCSs) are described as semiosis, signs in action. We explored the relationship between semiosis and cognition, as conceived by C. S. Peirce, in association with the notion of distributed cognitive system (DCS). We introduce Peircean externalist approach with an emphasis on the notion of temporal distribution of semiosis, and describe DCSs, and their elements, as "sign in action". To develop this argument, we describe an example of DCS -- verbal-musical improvisation of repente, repentismo, or viola singing. It is a phenomenon of verbal-musical improvisation that takes the form of a challenge in versified oral poetry. We describe the phenomenon as the embodiment of the formal structure of a cognitive task and an inferential process. This embodiment corresponds to a semiotization of the repente performances as DCSs. The temporally distributed tendency of repentismo organizes the DCS as a system that performs metasemiotic experiments on the action of signs.
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4. |
- Aziz, Shazed, et al.
(author)
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Plant-Like Tropisms in Artificial Muscles
- 2023
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In: Advanced Materials. - : WILEY-V C H VERLAG GMBH. - 0935-9648 .- 1521-4095.
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Journal article (peer-reviewed)abstract
- Helical plants have the ability of tropisms to respond to natural stimuli, and biomimicry of such helical shapes into artificial muscles has been vastly popular. However, the shape-mimicked actuators only respond to artificially provided stimulus, they are not adaptive to variable natural conditions, thus being unsuitable for real-life applications where on-demand, autonomous operations are required. Novel artificial muscles made of hierarchically patterned helically wound yarns that are self-adaptive to environmental humidity and temperature changes are demonstrated here. Unlike shape-mimicked artificial muscles, a unique microstructural biomimicking approach is adopted, where the muscle yarns can effectively replicate the hydrotropism and thermotropism of helical plants to their microfibril level using plant-like microstructural memories. Large strokes, with rapid movement, are obtained when the individual microfilament of yarn is inlaid with hydrogel and further twisted into a coil-shaped hierarchical structure. The developed artificial muscle provides an average actuation speed of approximate to 5.2% s(-1) at expansion and approximate to 3.1% s(-1) at contraction cycles, being the fastest amongst previously demonstrated actuators of similar type. It is demonstrated that these muscle yarns can autonomously close a window in wet climates. The building block yarns are washable without any material degradation, making them suitable for smart, reusable textile and soft robotic devices.
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6. |
- Fedorov, A., et al.
(author)
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Segmented diffusion-weighted imaging of the prostate: Application to transperineal in-bore 3 T MR image-guided targeted biopsy
- 2016
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In: Magnetic Resonance Imaging. - : Elsevier BV. - 0730-725X. ; 34:8, s. 1146-1154
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Journal article (peer-reviewed)abstract
- Objective: This study aims to evaluate the applicability of using single-shot and multi-shot segmented diffusion-weighted imaging (DWI) techniques to support biopsy target localization in a cohort of targeted MRI-guided prostate biopsy patients. Materials and methods: Single-shot echo-planar diffusion-weighted imaging (SS-DWI) and multi-shot segmented (MS-DWI) were performed intra-procedurally on a 3 Tesla system in a total of 35 men, who underwent in-bore prostate biopsy inside the scanner bore. Comparisons between SS-DWI and MS-DWI were performed with (in 16 men) and without (in 19 men) parallel coil acceleration (iPAT) for SS-DWI. Overall image quality and artifacts were scored by a radiologist and scores were compared with the Wilcoxon-Mann-Whitney rank test. Correlation between the presence of air and image quality scores was evaluated with Spearman statistics. To quantify distortion, the anteroposterior prostate dimension was measured in SS and MS b = 0 diffusion- and T-2-weighted images. Signal-to-noise ratio was estimated in a phantom experiment. Agreement and accuracy of targeting based on retrospective localization of restricted diffusion areas in DWI was evaluated with respect to the targets identified using multi-parametric MRI (mpMRI). Results: Compared to SS-DWI without iPAT, the average image quality score in MS-DWI improved from 2.0 to 33 (p < 0.005) and the artifact score improved from 23 to 1.4 (p < 0.005). When iPAT was used in SS-DWI, the average image quality score in MS-DWI improved from 2.6 to 33 (p < 0.05) and the artifact score improved from 2.1 to 1.4 (p < 0.01). Image quality (rho = 0.74, p < 0.0005) and artifact scores (rho = 0.77, p < 0.0005) both showed strong correlation with the presence of air in the rectum for the SS-DWI sequence without iPAT. These correlations remained significant when iPAT was enabled (rho = 052, p < 0.05 and rho = 0.64, p < 0.01). For the comparison MS-DWI vs SS-DWI without iPAT, median differences between diffusion- and T2-weighted image gland measurements were 1.1 (0.03-10.4) mm and 4.4 (0.5-22.7) mm, respectively. In the SS-DWI-iPAT cohort, median gland dimension differences were 2.7 (0.4-5.9) mm and 42 (0.7-8.9) mm, respectively. Out of the total of 89 targets identified in mpMRI, 20 had corresponding restricted diffusion areas in SS-DWI and 28 in MS-DWI. No statistically significant difference was observed between the distances for the targets in the target-concordant SS- and MS-DWI restricted diffusion areas (5.5 mm in SS-DWI vs 45 mm in MS-DWI, p > 0.05). Conclusions: MS-DWI applied to prostate imaging leads to a significant reduction of image distortion in comparison with SS-DWI. There is no sufficient evidence however to suggest that intra-procedural DWI can serve as a replacement for tracking of the targets identified in mpMRI for the purposes of targeted MRI-guided prostate biopsy. (C) 2016 Elsevier Inc. All rights reserved.
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7. |
- Fejes, Andreas, 1977-, et al.
(author)
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Popular education, migration and a discourse of inclusion
- 2017
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In: Studies in the Education of Adults. - : Taylor & Francis. - 0266-0830 .- 1478-9833. ; 49:2, s. 214-227
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Journal article (peer-reviewed)abstract
- In this article, we focus on how a discourse on inclusion operates through language learning programmes for migrants. We direct our attention to a new form of activities funded by the Swedish government, Swedish from day 1, organised by popular education institutions. These activities emerged in connection to the migra- tion flows in 2015, receiving large sums in funding from the gov- ernment. They target newly arrived migrants who are waiting for a decision on their resident permit application, and the aim is to provide an introduction to the Swedish language as well as to Swedish society. Drawing on a Foucault-inspired theorization, we direct our attention to how a discourse of inclusion operate through the way these initiatives are spoken about, how these activities are described, what they are intended to attain, and what kind of citizen is shaped through such a way of speaking. We analyse policy documents produced by different actors involved in the process of Swedish from day 1, as well as case study descriptions of courses. We argue that the discourse on inclusion that emerges encompasses a wider as well as an instru- mental notion of inclusion. Migrants are positioned as ‘in deficit’, in need of knowledge in order to become included. Such know- ledge does not limit itself to knowledge of the Swedish language and knowledge about Swedish society, but also knowledge of health issues, and knowledge about how the migrants can market themselves and their competencies. We end the article by relating this discourse on inclusion to a wider discussion on neoliberal rationalities of governing.
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8. |
- Fejes, Andreas, 1977-, et al.
(author)
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Prólogo : Un libro sobre Foucault y la educación permanente
- 2010. - 1
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In: Foucault y el aprendizaje permanente. - Xàtiva : Ediciones del CREC. - 9788493777241 ; , s. 23-30
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Book chapter (other academic/artistic)abstract
- Era necesaria en nuestro presente histórico una obra colectiva y plural que cuestionase desde una rigurosa investigación empírica los discursos, las prácticas y las políticas de la educación permanente, entendida no sólo como algo diferente de la educación de adultos, aunque la englobe, sino también como una forma específica de experiencia propia de la racionalidad gubernamental neoliberal Y también era necesario que fuese utilizada la caja de herramientas de Foucault, especialmente la elaborada en torno al concepto de gubernamentalidad, para profundizar la línea de trabajo de una historia crítica del presente, que fuese capaz, a su vez, de articular las aportaciones de Marx con las de Nietzsche en la investigación crítica del presente.
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9. |
- Fejes, Andreas, et al.
(author)
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Recognising Prior Learning : Understanding the Relations Among Experience, Learning and Recognition from a Constructivist Perspective
- 2009
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In: Vocations and Learning. - : Springer Science and Business Media LLC. - 1874-785X .- 1874-7868. ; 2:1, s. 37-55
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Journal article (peer-reviewed)abstract
- This article discusses the relation between experience and learning in the context of recognition of prior learning (RPL) and from an experiential constructivist perspective. The study is based on a case of in-service training, based on RPL, in the care sector for elderly people. The data consist of interviews with actors in this process, which have been analysed with a qualitative interpretative approach. The results show how prior learning plays a central role in the training process, both on an individual and a collective level. The participants’ prior learning is taken as the starting point, particularly in learning conversations where prior learning is made visible and used, and where participants learn from each other. Further, new learning is taking place as a consequence of the recognition process, and the study particularly highlights how prior experiences could be the basis of new learning in a process of reflection and discussion.
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10. |
- Ferm Almqvist, Cecilia, Professor, 1966-, et al.
(author)
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Tid, rum, mellanrum : delaktighet i estetisk verksamhet
- 2023. - 1
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Book (other academic/artistic)abstract
- Här uppmärksammas fenomenet delaktighet i estetisk verksamhet, något som är aktuellt i lärarutbildningar, såväl allmänna som med inriktning på estetiska ämnen, och i utbildningar som riktar sig mot kulturskola och annan fri verksamhet.Författarna har fungerat som följeforskare i två Arvsfondsfinansierade konstpedagogiska projekt, Alla har rätt och Sammankonst drivna av Kulturverket. Baserat på forskningen tydliggörs vad delaktighet i estetisk verksamhet kan vara, och vilka krav det ställer på organisation, kollegium och förhållningssätt i sammanhang där konstuttryck och pedagogik möts.Specifikt belyser författarna delatighetsaspekterna tid, rum och mellanrum liksom det dialogiska förhållningssätt som drivit Kulturverkets arbete.Cecilia Ferm Almqvist är professor i pedagogik och musikpedagogik vid Södertörns högskola respektive Stockholms musikpedagogiska institut. Linn Hentschel är lektor i pedagogiskt arbete med inriktning mot musik vid Umeå universitet.
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