Coming dissertations at Uppsala university
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Frustrated magnetism in icosahedral structures : The influence of order-disorder in quasicrystals and approximant crystals
Link: http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-524558
This work will begin with an introduction to quasicrystals (QCs) and their structure, defining the unit cell-equivalent for icosahedral quasiperiodicity: a 3D tiling based on the golden ratio and aperiodic in all three dimensions. We briefly present the cut-and-project method used to generate QCs from a higher dimension hypercrystal, and how to build the 3D Penrose tilings, composed of the two golden rhombohedra. We introduce the atomic elementary units used to understand Tsai-type icosahedral QCs and their related approximant crystals (ACs). Approximants are conventional periodic crystals with local atomic environments very similar to their QC counterparts. Two methods for synthesis of Tsai-type QCs and approximants are introduced, the self-flux method as well as a rapid quench method. We describe briefly the differences between the two methods and aspect about phase stability for QCs and ACs obtained in binary and ternary systems. Various types of structural modulations can be induced in ACs which are absent from QCs. We present a new criterion discovered during the doctoral studies, which links the structure of existing ACs to the existence of stable QC counterparts. Basic concepts of magnetism relevant to Tsai systems are then introduced, with a description of the 4f shell magnetism in lanthanide elements, how it differs from transition metal magnetism, with localized (and relatively large) magnetic moments. In intermetallic systems such as Tsai-type QCs and ACs, the main type of magnetic interaction is of RKKY type. We link their structure to the magnetic behavior and phase transition that can occur in frustrated systems: spin glass, reentrant spin glass, spin ice, etc. and how they can be related to various Tsai systems.
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Playing with the Global : Family Dynamics and International Education in a Marketised Preschool Landscape
Link: http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-524213
The surge in popularity of international schools around the world has extended to the domain of Early Childhood Education and Care. In the past few decades, international preschools have become more commonplace in marketised educational contexts. This thesis studies families who enrol their children in international preschools in Stockholm, Sweden, framing the rise of these institutions as embedded within two aspects of globalisation: the growing worth of transnational assets and the increasing prevalence of transnational families, encompassing those raising their children in foreign countries and those composed of parents from different national backgrounds.
The study, departing from Pierre Bourdieu’s relational sociology, examines preschool choice from two angles. The first inspects the social recruitment of international preschools through statistical analysis of individual-level register data concerning families. This analysis considers social characteristics such as education level, income, and migration histories. Secondly, through interviews with middle-class parents, it explores families’ choice-making processes, examining how they navigate their children’s preschool options and ultimately select international preschools.
The results show that international preschools cater to families with strong and weak social positions and those with Swedish and foreign backgrounds, which evidences a widespread belief in the value of transnational attributes. However, differences between international preschools’ specific languages highlighted that some languages are more closely linked with social advantage than others. Preschool choice was found to be shaped by complex dynamics, wherein social class, gender, migration experiences, family structures, and parenting cultures intersected with the local context and supply of preschools, both international and not. This first encounter with institutionalised education emerged as a situation where families renegotiated their family identity and priorities. Due to preschool children’s young age, transnational assets were not always easily transmitted or acquired, especially when parents desired divergent international and national investments. Such acquisition demanded considerable efforts in parenting, commuting to international preschools, and altering family dynamics. Preschools were shown to serve as providers of transnational assets and as possible hindrances to the particular forms of internationality families wished to nurture in their children.
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Information prior to prenatal diagnosis : Knowledge, informational needs and decision-making
Link: http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-521768
The overall aim of this thesis was to explore different aspects of information relevant to decision-making regarding prenatal diagnosis (PND) for chromosomal anomalies (CA).
In Papers I–II, women and partners undergoing combined ultrasound and biochemistry (CUB) tests, invasive tests or declining PND for CAs answered a questionnaire. Overall, expectant parents had varying to low levels of knowledge about Down syndrome (DS), with few differences between women and partners, or between those accepting or declining PND. Thus, knowledge at these levels does not seem to influence the decision to accept or decline PND. Some seem to regard CUB as a routine test.
Paper III explored midwives' perspectives with a questionnaire. The majority believed they had not received sufficient education about PND, and few felt knowledgeable enough to provide information about DS. Most midwives desired more education regarding tests and DS. Actual knowledge levels concerning DS varied, and in some cases, were low.
Paper IV explored the factors influencing decisions concerning PND through interviews with pregnant women. The decision-making process is affected by individual factors (i.e. attitude towards anomalies, worry and need for reassurance, and self-perceived risk) and external factors (i.e. test characteristics and influence from others). The quality of life for an affected individual and the impact on the family is important for some women when making decisions about PND. Healthcare professionals can influence women’s decisions through their attitudes, how they present the tests, and the woman’s individual probability of CAs.
Paper V used Q methodology to explore women’s views on what is important when receiving information about PND. Some women prefer receiving information gradually, while others prefer comprehensive information early in pregnancy. Some value information about the conditions tested for early in the process. The extent to which women wanted to involve their partner in the decision-making process varied. None preferred group information sessions.
In conclusion, providing information and pre-test counselling to pregnant women is a complex task. There is room for improvement in the information provided to expectant parents, and in the education provided to midwives related to PND and DS. Women’s decisions regarding PND are influenced by both individual and external factors. Information about test characteristics and conditions tested for could be helpful for pregnant women when they make decisions. Healthcare professionals’ approach can influence women’s decisions. Women have varying informational needs, making individual and non-directive pre-test counselling with a competent healthcare professional essential to facilitate informed decision-making.