Chemical intolerance

Chemical intolerance (CI) is a term used to describe a condition in which the sufferer experiences a complex array of recurrent unspecific symptoms attributed to low-level chemical exposure that most people regard as unproblematic. Severe CI constitutes the distinguishing feature of multiple chemical sensitivity (MCS). The symptoms reported by CI subjects are manifold, involving symptoms from multiple organs systems. In severe cases of CI, the condition can cause considerable life-style limitations with severe social, occupational and economic consequences. As no diagnostic tools for CI are available, the presence of the condition can only be established in accordance to criteria definitions. Numerous modes of action have been suggested to explain CI, with the most commonly discussed theories involving the immune system, central nervous system, olfactory and respiratory systems as well as altered metabolic capacity, behavioral conditioning and emotional regulation. However, in spite of more than 50 years of research, there is still a great deal of uncertainties regarding the event(s) and underlying mechanism(s) behind symptom elicitation. As a result, patients are often misdiagnosed or offered health care solutions with limited or no effect, and they experience being met with mistrust and doubt by health care professionals, the social care system and by friends and relatives. Evidence-based treatment options are currently unavailable, however, a person-centered care model based on a multidisciplinary treatment approach and individualized care plans have shown promising results. With this in mind, further research studies and health care solutions should be based on a multifactorial and interdisciplinary approach.</p

Chemosensory perception, symptoms and autonomic responses during chemical exposure in multiple chemical sensitivity

PURPOSE: Multiple chemical sensitivity (MCS) is a prevalent medically unexplained symptom characterized by symptom reactions to everyday chemical exposure below hygienic thresholds. The aim of this study was to investigate the expressions of hyper-reactivity in MCS during whole-body exposure to low concentrations of the odorant n-butanol.METHODS: We exposed 18 participants with MCS and 18 non-ill controls to a low concentration of the odorant n-butanol using an exposure chamber. The first 10 min constituted blank exposure, after which the n-butanol concentration increased and reached a plateau at 11.5 mg/m(3).RESULTS: MCS participants, compared with controls, reported greater perceived odor intensities, more unpleasantness to the exposure and increasing symptoms over time. MCS participants also expressed higher pulse rate and lower pulse rate variability than controls did. No group differences were found for breathing rate or tonic electrodermal activity responses.CONCLUSIONS: We conclude that MCS sufferers differ from healthy controls in terms of autonomic responses, symptoms and chemosensory perception during chemical exposure.</p

Reduced order modeling in structural dynamics : Consideration of local nonlinearities

A structural design process may include various load cases for which a sufficient load-bearing capacity must be demonstrated. In addition to static load cases, a verification of dynamic loads, e.g. accidental loads such as blast and impact loading, may be required. To this end, the response may be estimated using a computational model representing an idealized structure. Particularly in the conceptual design phase, a time-efficient and straightforward modelingapproach can be of great utility, allowing for an interactive design process where alternative designs may be tested. Furthermore, a dynamic response analysis often requires some form of time (or frequency) discretization and can therefore become computationally expensive compared to the corresponding static analysis. The balance between performance and accuracy as well as the purpose, i.e. the output quantities of interest, are thus important aspects in a dynamic response analysis.A structural dynamics analysis typically requires a model being accurate as well as computationally efficient. The model accuracy is particularly important in a verification of structurescharacterized by brittle failure modes, i.e. that do not deform plastically before failure. Furthermore,to avoid a too conservative design and to ensure sufficient accuracy, it can be necessary to consider the nonlinear response of a structure, e.g. due to contact interactions or nonlinear material behavior. However, a nonlinear structural dynamic problem often requires computationallyexpensive solution methods. Consequently, there is a need for modeling strategies that enable time-efficient, accurate analyses and a straightforward modeling approach, appropriate in a structural design process. To achieve this, a reduced order model can be established providing an accurate prediction of important output quantities.Dynamic substructuring turns out to be an important aspect in the process of developing reduced order models. By subdivision of the structure into substructures, dynamic substructuring can be employed to effectively adjust the level of accuracy for different parts of the structure. For example, substructures that remain linear elastic can typically be modeled using mode-superposition methods whereas substructures which exhibit a nonlinear behavior can berepresented by a refined submodel.In the dissertation, strategies for reduced order modeling are investigated on the basis of structural engineering applications within two different areas, namely concrete structures subjected to blast loading and glass structures subjected to soft-body impact. Interestingly, however, some of the challenges with regard to the structural dynamics problems are similar. In particular, the response of higher order modes may be of importance and, moreover, an accuraterepresentation of the structural behavior may necessitate a model considering local nonlinearities.By means of dynamic substructuring, computationally efficient analysis techniques are developed for evaluating concrete structures subjected to blast loading, appropriate for use in a structural design process. In particular, a comparison to commonly used modeling strategies, using equivalent single-degree-of-freedom systems, suggests that the developed models providean increased accuracy of the shear force. Brittle failure modes such as shear failure are typically critical for concrete structures subjected to blast loading.Furthermore, reduced order models are established for verification of glass panels subjected to soft-body impact. In particular, a non-linear viscous single-degree-of-freedom system is proposed for reduced modeling of the standardized EN 12600 impactor. Further, the response of higher order modes is considered using a set of load-dependent mode shapes. The developed models are validated by experimental tests of impact on glass panels.Finally, a review of various reduced order modeling techniques is presented which, in a broader perspective, provide a basis for developing reduced order models in various structural engineering applications

No Digital "Castles in the Air": Online Non-Participation and the Radical Left

This article presents results from a study of online presence in activist milieus associated with the radical left in Sweden discussed from a perspective of non-participation. With the aim to further the understanding of digital non-participation as communicative strategy in activism, it builds upon empirical findings and argues that the online practices and use of social media, as could be observed in milieus associated with the radical left, indicates active non-participation and that this, in turn, is related to the ambition to claim autonomy. The article draws from existing scholarship on critical perspectives on protest movements and social media as well as empirical examples of online content published by radical leftist groups. Furthermore, it analyses how these activities could be understood in terms of active and passive non-participation, abstention or adaptation to social media affordances, as well as implosion of the social in digital media. The findings suggest that much of the activities in the material could be described as active non-participation and that this media practice relates to ideological positioning and values in the milieu

Miniaturized high-energy radiation drain filters for quantum computing applications

Quantum Processing Units (QPUs) using superconducting qubits are known for their sensitivity to various types of radiation and many different aspects are being worked on in order to increase their resilience against noise. Superconducting qubits are especially sensitive frequencies with energy exceeding twice the superconducting energy gap of the superconductor. Above this frequency, Copper-pairs start to break, which partially disrupts superconductivity and degrades the performance of the QPU. In order to tackle this problem, a new type of low pass filtering technique called High Energy Radiation Drain (HERD) has been developed at at Chalmers University of Technology. Unlike previously employed filters relying on absorptive materials and resonant circuits to block high-frequency photons, this novel filtering technique overcomes the trade-off between low losses in the passband and high attenuation in the stopband. However, the filter is relatively large compared other filtering techniques, which makes it less suitable for high qubit density systems. In this thesis, we focus on the miniaturization of the HERD filtering technology and present two devices which have a reduced size of 32-57% and 47% respectively compared to their predecessor. The first device, implemented in printed circuit board technology, is manufactured and characterized with a resulting insertion loss of more than 40 dB above 80 GHz and an insertion loss of less than 0.29 dB below 8 GHz, measured at 77 K. The results show good agreement between measurements and simulations. In addition, a software is developed for performing eigenmode field decomposition of the filtering structure, which is used to better understand how the field couples to the filtering structure inside the prototype. The insights obtained from simulations and the field decomposition is then used to design the second device, a miniaturized coaxial HERD filter. The results shows that the HERD filtering technique can be made suitable for high qubit density systems where further miniaturization beyond this thesis should be possible

Reduced Order Modeling and Substructuring : Applications in Nonlinear Structural Dynamics

A structural design process typically involves various load cases for which a sufficient load-bearing capacity must be demonstrated. In addition to static load cases, a verification of dynamic loads, such as blast and impact loading, may be required. To this end, the response can be estimated using computational models representing an idealized structure, often formulated using the finite element method. In contrast to static analyses, a dynamic response analysis generally requires some form of time (or frequency) discretization. Furthermore, to properly capture the structural behavior, it can be necessary to consider nonlinear effects, e.g., due to contact conditions, nonlinear material behaviors, or geometrically nonlinear effects. The repeated solution in time of large nonlinear finite element models can be computationally expensive and time-consuming. Consequently, there is a need for computationally efficient modeling approaches, allowing for an interactive design process where alternative designs may be tested in a time-efficient manner.By generating a reduced order model, the aim is to reduce the system size while maintaining sufficient accuracy of important output quantities. Hence, the computational cost can be reduced by analyzing a smaller, approximate system. For continuous structural dynamics problems discretized using the finite element method, reduced order models can be obtained by introducing a reduction basis. More specifically, the response is approximated using a set of time-independent displacement fields, referred to as mode shapes, which constitute the basis vectors of the modal basis. This approach is well-established and frequently used within linear structural dynamics. In the context of nonlinear structural dynamics, modal methods for reduced order modeling have gained more prominence during the last decades and is still an active area of research.In the dissertation, strategies for nonlinear reduced order modeling are developed on the basis of structural engineering applications within two different areas; namely, concerning concrete structures subjected to blast loading and glass structures subjected to impact loading. Some of the challenges with regard to structural dynamics modeling are similar. In particular, brittle failure modes are often critical, why the response of higher order modes can be of particular importance. Moreover, an accurate representation of the structural behavior typically necessitates models considering nonlinear behaviors. More specifically, the dynamic problems involve localized nonlinearities in the form of contact conditions and joints, as well as geometric nonlinearity which, in contrast, is a distributed nonlinearity where degrees of freedoms throughout the structure are nonlinearly coupled.Impact loading is a fundamental load case in design of glazed barriers, such as full-height facades and balustrades, which often governs the design. In this work, modeling strategies were developed for predicting the pre-failure elastic response of flat glass panels subjected to a standardized impactor, which represent a human body falling towards the glass panel. The response of glass panels, having a small thickness compared to the span width, are typically characterized by bending-stretching coupling effects. To consider these effects, which result in a geometrically nonlinear behavior, reduction bases were generated using bending modes and the associated static modal derivatives, corresponding to the second order terms in a Taylor’s expansion of the quasi-static displacement field. Moreover, approximate techniques for modeling contact were proposed, and a nonlinear viscous single-degree-of-freedom model was developed for reduced modeling of the impacting body. The response was evaluated based on experimental data and detailed finite element models. For the studied load cases, the proposed model was shown to predict important output quantities, such as the glass principal stresses, with high accuracy.Furthermore, computationally efficient analysis techniques were developed for analysis of concrete structures subjected to blast loading. Specifically, reduced models including pre-defined plastic joints were developed by means of dynamic substructuring. A comparison to commonly used modeling strategies, which uses equivalent single-degree-of-freedom systems, suggests that the developed models provide a significantly improved accuracy of shear forces. This can be critical in a verification of brittle failure modes, such as diagonal and direct shear failure.Finally, a review of various reduced order modeling techniques is presented which, in a broader perspective, provide a basis for developing reduced order models in various structural dynamics applications

Child participation in the design of media and information literacy interventions: A scoping review and thematic analysis

The article presents findings from a review of scientific articles about media and information literacy interventions targeted at children and adolescents. More specifically, the review centers on the quantity and quality of child participation in the design of such interventions. The findings indicate that designs with high levels of child participation constitute a minority in the sample. Most of them aim at “behavior-relevant” outcomes, e.g., reduce smoking or obesity. Interventions aimed at “media-relevant” outcomes, e.g., helping children to become competent media users, seem less widespread. Based on these findings, we argue that top-down initiatives to the promotion of media and information literacy among children and adolescents run the risk of becoming irrelevant to the target group, and that child participation in the design of such interventions should be seen as an end in itself, at least if we subscribe to the idea of children’s rights in the digital age

Heifer contracting : the collaboration between the dairy farmer and the custom dairy heifer grower

This master thesis is about the collaboration between the custom dairy heifer grower and the dairy producer. The custom dairy heifer grower is a rather unusual strategy of reproductive management in Sweden compared to other countries like U.S. and Denmark where the specialization within dairy production gone much further. In these countries the research also has reached much further within this type of industry. However in Sweden there has been research made in the area of collaboration, but then only within collaborations in the industries of crop production, dairy production and pork meat. The down going trend of profitability within dairy production together with poor profitability in the beef industry could partly remedy if more collaborations around heifer contracting would arise. But since the industry still is of a rare kind in Sweden the knowledge about how these types of collaborative arrangements works and their contracts are put together is poor. By that the aim of this master thesis is formulated as follows: "how is usually the collaborative arrangement between the dairy producer and custom dairy heifer grower designed". Beyond this main purpose the thesis also answers which the main motives are and the pros and the cons of this type of collaborative arrangement. To answer the aim of this master thesis there has been a literature review made preferentially from U.S. studies together with a study made of contract theory applied on agriculture businesses. But the core of this thesis is the case studies interviews which are the main part of the empirical part of the thesis. The interviews were made with six custom heifer growers and four dairy producers in Sweden. Also some template calculations were made as a part of the empirical part of the thesis to cast some light on the difference between different contracting types. The empirical part of the thesis was analyzed by the help of the literature review and the contract theory. As follows a sample of the conclusions made in this master thesis. The most common type of contract among the studied cases was the buy/sell contract. A written contract should always be constituted in this type of collaborative arrangements. One of the most common motives for the heifer grower to be part in this type of collaborative arrangement is the possibility to lower the workload compared to the former dairy production. One of the most common motives for the dairy producer to take part in this kind of collaborative arrangement is the possibility to increase the number of milking cows. And much more can be reed in the conclusion part around motives, pros and cons and the design of this type of collaborative arrangement

The Role of Gender Differences in Partnering and Re-partnering for Gender Differences in Completed Fertility

Individuals increasingly enter a series of relationships during their reproductive years. As births in higher-order unions increase, fertility becomes partially contingent on re-partnering. Previous research suggests that men re-partner at higher rates than women. This study analyzes whether gender differences in partnering and re-partnering influence gender differences in cohort fertility. We use Finnish register data on all births, marriages, and cohabitations between the ages of 18 and 47 over four full birth cohorts. The gender differences in cohort fertility rate are decomposed into components due to birth rate differences and a compositional component owing to gender differences in the share partnered and re-partnered. We observe no impact of "re-partnering premium" on male fertility. Men have marginally higher re-partnering rates at older ages, when birth rates are low, whereas women have higher rates of partnering and re-partnering at prime childbearing ages. This compositional effect drives a "partnering" advantage for female fertility. This connection between gender differences in partnering and cohort fertility is true across educational levels

TVÄTTEN I ÖKNEN En diskursanalys av svensk och qatarisk mediebevakning av fotbolls – VM i Qatar

The FIFA World Cup 2022 in Qatar is amongst the most controversial sporting events in history. The country is accused of using the tournament as a political tool in order to launder its reputation and profile itself as attractive for future investment and tourism. Previous research has established that countries primarily host mega-sporting events to gain soft power. By using discourse analysis, this study examines how Qatari media tries to associate the tournament and the state with attractive values to gain soft power. The study also examines Swedish media in order to see whether Qatar’s soft power efforts have been successful or not. The results show that Qatari media portray the event as a symbol of pride in the middle east and associate it with attractive values such as peace, harmony and sustainability while also describing the state as tolerant and open to all peoples of the world. However, this is not the case in Swedish media who instead portray the tournament and the state of Qatar in a negative and unattractive way. This suggests that a soft – disempowerment effect has occurred in the Swedish context and an orientalist discourse appears which portrays Qatar as “the other”