abstract: Weevils are among the most diverse and evolutionarily successful animal lineages on Earth. Their success is driven in part by a structure called the rostrum, which gives weevil heads a characteristic "snout-like" appearance. Nut weevils in the genus Curculio use the rostrum to drill holes into developing fruits and nuts, wherein they deposit their eggs. During oviposition this exceedingly slender structure is bent into a straightened configuration - in some species up to 90° - but does not suffer any damage during this process. The performance of the snout is explained in terms of cuticle biomechanics and rostral curvature, as presented in a series of four interconnected studies. First, a micromechanical constitutive model of the cuticle is defined to predict and reconstruct the mechanical behavior of each region in the exoskeleton. Second, the effect of increased endocuticle thickness on the stiffness and fracture strength of the rostrum is assessed using force-controlled tensile testing. In the third chapter, these studies are integrated into finite element models of the snout, demonstrating that the Curculio rostrum is only able to withstand repeated, extreme bending because of modifications to the composite structure of the cuticle in the rostral apex. Finally, interspecific differences in the differential geometry of the snout are characterized to elucidate the role of biomechanical constraint in the evolution of rostral morphology for both males and females. Together these studies highlight the significance of cuticle biomechanics - heretofore unconsidered by others - as a source of constraint on the evolution of the rostrum and the mechanobiology of the genus Curculio. / Dissertation/Thesis / Doctoral Dissertation Evolutionary Biology 2009

Les microtubules sont des composants structuraux de cellules et gouvernent des fonctions cellulaires essentielles telles que les mitoses et le transport des vésicules. Ils sont composés de deux sous-unités non identiques (tubulines α et β), formant un dimère, et sont arrangés de sorte à former une structure tubulaire de 20nm de diamètre. Généralement, ils sont constitués de 13 ou 14 protofilaments arrangés en spirale. Les liaisons longitudinales entre dimères sont plus rigides et fortes que les liaisons latérales. Aussi, les microtubules sont des structures fortement anisotropes. Dans ces travaux de thèse, nous avons pour but de définir l'ensemble des coefficients élastique qui permet de reproduire leur comportement atomistique ainsi que de rendre compte de leur réponse mécanique selon des chemins de chargement variés. En négligeant la discontinuité hélicoïdale souvent observée, un microtubule est représenté par une structure triangulaire de dimères à partir desquels un volume élémentaire représentatif est défini. Un potentiel harmonique est utilisé pour décrire les interactions entre dimères voisins. A partir de l'estimation des constantes élastiques et de l'utilisation de la méthode proposée par Arslan et Boyce (2006) -alors pour analyser le comportement mécanique d'un réseau triangulaire de spectrines composant les membranes des globules rouges-, un modèle continu de comportement mécanique est présenté pour reproduire le comportement des parois des microtubules. Un modèle numérique éléments finis est ensuite créé pour modéliser le comportement d'un microtubule dans sa globalité. Des éléments coques sont utilisés pour reproduire les fines parois des microtubules. Les propriétés du modèle éléments finis sont ajustées à partir des résultats du modèle présenté ainsi qu'aux données expérimentales provenant de la littérature. La rigidité de flexion calculée au cours de simulation des tests de flexion 3 points est en accord avec les valeurs de la littérature. Ces tests révèlent les mécanismes de déformation en fonction de la longueur utile du tube utilisé: Flexion et cisaillement locaux de la paroi gouvernent la déformation pour de "petits" tubes. Pour des longueurs "moyennes" le cisaillement et la flexion du tube prédominent. Enfin, dans le cas de tubes "longs", la déformation est uniquement associée aux effets de flexion. Ces résultats témoignent de l'influence de l'anisotropie du tube sur la réponse observée selon différents mode de sollicitation. Ils permettent également d'expliquer l'évolution de la rigidité de flexion avec la longueur utile du tube, comme reportée dans la littérature. Enfin, des micrographes montrent la propension des extrémités des microtubules à diverger radialement -"à boucler"-. Une telle géométrie est causée par des instabilités propres aux microtubules et implique un état précontraint. Un «modèle d'interactions» est alors proposé de manière à considérer un état précontraint et ainsi reproduire la cinétique des instabilités des microtubules au cours de la polymérisation/dépolymérisation.

<p>This paper examines pupils’ conception of the Swedish schools constitutive values expressed in the Swedish curriculum. The main question was, at to what extent the schools constitutive values have influenced the pupils conception of their own values. That question problematizes the relation between values, constructed and carried by central administration, and their interpretation at local level by pupils. The study was conducted with qualitative analysis which included qualitative interviews with seven pupils in the last year of the Swedish school system. Phenomenology, hermeneutics, and phenomenographics have influenced the study. The qualitative interviews were abstracted into categories, related to this papers theoretical framework. The categories were taken from a taxonomy that breaks up the constitutive values into smaller pieces. The categories are presented here: <em>questions about conception of life, moral education, values education, civics education and citizenship education</em>. As well as categories the taxonomy shows a variable that goes from private to public and <em>questions about conception of life,</em> is the most private area and <em>citizenship education</em> is the most public. What each category resulted in was that pupils´ conception of the schools constitutive values could relate to the theoretical framework. Although many of the informants’ quotations pointed out standpoints that were related to the theoretical framework, some weren’t. Those included mostly the categories of public questions, such as <em>civic education</em> and <em>citizenship education</em>. In question of the pupils conception of moral education and values education the quotations showed that schools tend to focus on a rule based philosophy when fostering the pupils in to good moral and values. Also, pupils tend to focus on private good and see the schools constitutive values as a way to gain private good. This papers result brings up questions about; if the schools constitutive values are not well understood by pupils or if the constitutive values only are to be understood as private good. It also shows that the values constructed at a central level have a long way to travel to be acknowledged by the pupils. And along that travel several actors, such as teachers, interpret the constitutive values.</p>

Background and purpose: 5-Hydroxytryptamine (5-HT) has been shown to control and modulate many physiological and behavioural functions in insects. In this study, we report the cloning and pharmacological properties of a 5-HT1 receptor of an insect model for neurobiology, physiology and pharmacology. Experimental approach: A cDNA encoding for the Periplaneta americana 5-HT1 receptor was amplified from brain cDNA. The receptor was stably expressed in HEK 293 cells, and the functional and pharmacological properties were determined in cAMP assays. Receptor distribution was investigated by RT-PCR and by immunocytochemistry using an affinity-purified polyclonal antiserum. Key results: The P. americana 5-HT1 receptor (Pea5-HT1) shares pronounced sequence and functional similarity with mammalian 5-HT1 receptors. Activation with 5-HT reduced adenylyl cyclase activity in a dose-dependent manner. Pea5-HT1 was expressed as a constitutively active receptor with methiothepin acting as a neutral antagonist, and WAY 100635 as an inverse agonist. Receptor mRNA was present in various tissues including brain, salivary glands and midgut. Receptor-specific antibodies showed that the native protein was expressed in a glycosylated form in membrane samples of brain and salivary glands. Conclusions and implications: This study marks the first pharmacological identification of an inverse agonist and a neutral antagonist at an insect 5-HT1 receptor. The results presented here should facilitate further analyses of 5-HT1 receptors in mediating central and peripheral effects of 5-HT in insects.

The biogenic amine serotonin (5-HT) plays a key role in the regulation and modulation of many physiological and behavioural processes in both vertebrates and invertebrates. These functions are mediated through the binding of serotonin to its receptors, of which 13 subtypes have been characterized in vertebrates. We have isolated a cDNA from the honeybee Apis mellifera (Am5-ht7) sharing high similarity to members of the 5-HT7 receptor family. Expression of the Am5-HT7 receptor in HEK293 cells results in an increase in basal cAMP levels, suggesting that Am5-HT7 is expressed as a constitutively active receptor. Serotonin application to Am5-ht7-transfected cells elevates cyclic adenosine 3',5'-monophosphate (cAMP) levels in a dose-dependent manner (EC50 = 1.1-1.8 nM). The Am5-HT7 receptor is also activated by 5-carboxamidotryptamine, whereas methiothepin acts as an inverse agonist. Receptor expression has been investigated by RT-PCR, in situ hybridization, and western blotting experiments. Receptor mRNA is expressed in the perikarya of various brain neuropils, including intrinsic mushroom body neurons, and in peripheral organs. This study marks the first comprehensive characterization of a serotonin receptor in the honeybee and should facilitate further analysis of the role(s) of the receptor in mediating the various central and peripheral effects of 5-HT.

The idea of accounting as a constitutive means, making people think and act in particular ways, is well established in the social strand of accounting literature. In professional organisations, for example, accounting is claimed to be critical to processes of turning people into rational and responsible economic actors. However, this thesis refocuses the empirical attention away from the organisation and into the private sphere of people’s everyday financial lives. As this is a field partly inhabited by people who for various reasons are believed to have difficulty in making sense of financial accounts, a dilemma arises regarding how to influence people’s way of managing their own finances by means of accounting information. How this dilemma is assumed to be resolved in order to make accounting matter is the query of this thesis. Through a study of four cases, the thesis investigates the practices of public authorities, a television makeover show, and a pension insurance company – here referred to as accounting framers – whose task it is to construct accounting in such a way so as to make it come across as important, relevant and useful to various groups of the general public. By examining how people’s accounting interpretations are elaborated in order to make them responsive to financial accounts, the thesis contributes to problematising the constitutive role of accounting and the conditions believed to enable it to turn people into financially responsible actors.

In this licentiate thesis the work done in the TURBO POWER project Influence of high temperature hold times on the fatigue life of nickel-based superalloys will be presented. The overall objective of this project is to develop and evaluate tools for designing against fatigue in gas turbine applications, with special focus on the nickel-based superalloy Inconel 718. Firstly, the constitutive behaviour of the material has been been studied, where focus has been placed on trying to describe the mean stress relaxation and initial softening of the material under intermediate temperatures. Secondly, the fatigue crack propagation behaviour under high temperature hold times has been studied. Focus has here been placed on investigating the main fatigue crack propagation phenomena with the aim of setting up a basis for fatigue crack propagation modelling. This thesis is divided into two parts. The first part describes the general framework, including basic constitutive and fatigue crack propagation behaviour as well as a theoretical background for the constitutive modelling of mean stress relaxation. This framework is then used in the second part, which consists of the four included papers.

This thesis’ main theme is the relation between school practices and the constitutive values explicitly endorsed in the Swedish national curriculum. It consists of four articles. Article I examines the new educational circumstances in a multicultural society. It problematizes the school’s task to find a balance between contributing to a certain cultural consensus, the common and shared, and to increase the ability to live with a cultural multiplicity. The article addresses the need for intercultural education for the realisation of a democratic classroom. Article II addresses the challenge for schools to advocate constitutive values in a multicultural society. It problematizes the relation between the curriculum’s values, stipulated at central level, and their interpretation and implementation at local level, i.e., in the class-room. An action-research project in a Swedish school illustrates the teachers’ struggle to realize these values in daily practice. The project resulted in the teachers move from abstract to concrete discussions of the constitutive values, as well as changes in their daily practice. Overall, the paper focuses on possibilities for deliberation in a multicultural school. Article III highlights schooling as a moral practice. It builds on a field study which investigates the relation between the curriculum’s stipulated values and the enacted curriculum. Episodes of moral steering are presented together with the teachers’ subsequent evaluation of these incidents. These episodes suggest that insofar as individual beliefs and moment-by-moment responses may lead to actions with counteract constitutive values, moral practices must also be a deliberative practice where alternatives are weighed and courses of action are adopted. Article IV develops the discussion concerning the school as a moral arena. A short lunch episode from the school study illustrates the discrepancy between the curriculum’s constitutive values and their realization in practice. The paper suggests that episodes at the margins of school practices may be just as important to the moral curriculum of school as the knowledge-related elements conventionally deemed to be the core of the curriculum. In summary, the thesis demonstrates that the assignment to foster the coming citizens in a multicultural school is complex. Other values than those stipulated in the curriculum steer teachers’ actions. Moreover, it is a thorny mission to accomplish an equal school in an unequal society. Nonetheless, there is a need for awareness among pedagogues concerning the correspondence between societal values, the hierarchy of social groups, individual values, the curriculum’s values, and the teacher’s assignment. The curriculum’s values have to be taken into account just as well as individual attitudes, prejudices and taken-for-granted notions have to be clarified, confronted, defended or abandoned. Interpreting, internalising and applying democratic values in school is a never-ending process.

This paper examines pupils’ conception of the Swedish schools constitutive values expressed in the Swedish curriculum. The main question was, at to what extent the schools constitutive values have influenced the pupils conception of their own values. That question problematizes the relation between values, constructed and carried by central administration, and their interpretation at local level by pupils. The study was conducted with qualitative analysis which included qualitative interviews with seven pupils in the last year of the Swedish school system. Phenomenology, hermeneutics, and phenomenographics have influenced the study. The qualitative interviews were abstracted into categories, related to this papers theoretical framework. The categories were taken from a taxonomy that breaks up the constitutive values into smaller pieces. The categories are presented here: questions about conception of life, moral education, values education, civics education and citizenship education. As well as categories the taxonomy shows a variable that goes from private to public and questions about conception of life, is the most private area and citizenship education is the most public. What each category resulted in was that pupils´ conception of the schools constitutive values could relate to the theoretical framework. Although many of the informants’ quotations pointed out standpoints that were related to the theoretical framework, some weren’t. Those included mostly the categories of public questions, such as civic education and citizenship education. In question of the pupils conception of moral education and values education the quotations showed that schools tend to focus on a rule based philosophy when fostering the pupils in to good moral and values. Also, pupils tend to focus on private good and see the schools constitutive values as a way to gain private good. This papers result brings up questions about; if the schools constitutive values are not well understood by pupils or if the constitutive values only are to be understood as private good. It also shows that the values constructed at a central level have a long way to travel to be acknowledged by the pupils. And along that travel several actors, such as teachers, interpret the constitutive values.

The occurrence of hot tearing during solidification is one of the major factors influencing both the quality and productivity of aluminum castings. In order to reduce the formation of hot tears, quantitative information regarding both hot tearing formation and semi-solid deformation is essential. In this study, the mechanisms of hot tearing and semi-solid deformation have been investigated via two novel techniques: x-ray micro-tomography on material deformed in the semi-solid region, and development of a three phase microstructural model based on a geometry derived from a Voronoi diagram with rounded corners and porosity. Numerical techniques were utilized to quantify both the size evolution and orientation of internal damage relative to void growth. In order to conduct the above research, a new semi-solid tensile deformation methodology was devised which uses a two thermocouple control technique to enable accurate measurement of semi-solid tensile strength and ductility. The experimental work was conducted on the aluminum – magnesium alloy AA5182 in the as-cast and hot isostatic pressing (HIP) states. The x-ray micro-tomography technique was used to observe that semi-solid deformation is accommodated by internal damage via growth of as-cast porosity and the nucleation of new damage-based voids. As the volume fraction of damage increases, the growth of voids occurs in an orientation perpendicular to the loading direction, both through expansion within the grain boundary liquid and via coalescence between voids. The damage then localizes, causing failure. The finite element semi-solid microstructural model was used to explore the effects of fraction solid, fraction porosity, and grain size on semi-solid constitutive behaviour. The simulations revealed that increased grain size and fraction porosity lead to a reduction in flow stress for a given fraction solid. Furthermore, local strain accumulation was linked to hot tearing, since strain localizes in the liquid very early in the deformation process. Based on the model predictions, a new constitutive relationship was developed over the range 0.75 < fs < 0.95. Together, these two techniques have provided powerful new insight, such as the critical role played by as-cast porosity, on the phenomena of hot tearing and semi-solid deformation in aluminum alloys.