Syftet med denna uppsats har varit att undersöka hur uppfattningen av det svenska vattenkraftsystemet förändrades under 1960-talet, samt att tillämpa teorin Social Construction of Technology, SCOT, på vattenkraften genom att studera debatten om Vindelälven. Frågan om Vattenfall skulle tillåtas bygga ut Vindelälven var central i 1960-talets vattenkraftsdebatt. I uppsatsen undersöks hur de tre grupperna Vattenfall, Svenska Naturskyddsföreningen och lokalbefolkningen längs älven förhöll sig till frågan om Vindelälvens framtid och vilka argument de använde sig av i debatten om älven. Uppsatsen undersöker om Vattenfall, Naturskyddsföreningen och lokalbefolkningen kan förstås som tre relevanta grupper enligt SCOTs definition, samt huruvida det svenska vattenkraftsystemet nådde closure 1970. Det material som har studerats utgörs av tidnings- och tidskriftsartiklar från de tre grupperna, publicerade under perioden 1960—1970. Resultatet av undersökningen visar att Vattenfall och Naturskyddsföreningen uppfyller kriterierna för att betraktas som två relevanta grupper enligt SCOT. Vad gäller lokalbefolkningen är det mer komplicerat. Invånarna längs älven delar inte en gemensam uppfattning om utbyggnaden av Vindelälven och kan således inte betraktas som en relevant grupp, däremot finns det undergrupper som eventuellt uppfyller kriterierna. 1970 års beslut att bevara älven var avgörande för den fortsatta utbyggnaden av svenska älvar och kan ses som ett första steg på det svenska vattenkraftsystemets väg mot closure, vilket förmodligen nåddes 1993 i och med riksdagens beslut att klassa fyra älvar som nationalälvar.

Premolars are the most commonly extracted teeth to provide space to correct crowding and excessive labial protrusion. After treatment, the extraction spaces have to remain closed. Nevertheless, several studies have shown that there is a tendency for some relapse even in patients finished with an adequate occlusion. The objective of this study was to compare the stability of extraction space closure of the first and second premolars. A sample 72 patients´ dental casts were divided into two groups. Group 1, comprised 29 patients (116 extraction spaces) were treated with first premolar extractions at a mean initial age of 13.78 years and group 2, comprised 43 patients (100 extraction spaces) were treated with second premolar extractions at a mean initial age of 15.20 years. The dental casts obtained at pretrement, posttreament and a between 3 to 4 years postretention were digitized using a 3- dimensional scanner (R700; 3Shape,Copenhagen, Denmark). Chi-Square tests were used to compare the numbers of open and closed extraction spaces after treatment and at long-term posttreatment. T tests were used to compare the amount of spaces at posttreatment and at the long-term posttreatment stages. These tests were also performed in subgroups with completely closed extraction sites at posttreatment. The groups showed similar numbers of extraction sites reopening. First and second premolar extraction space closure present a similar tendency for reopening. Considering only the cases that showed completely closed extraction spaces in the final dental models, extraction space reopening was larger in the first premolar extraction group in the maxillary arch. / Os pré-molares são os dentes mais comumente extraídos para corrigir o apinhamento dentário e à protrusão labial excessiva. Após o tratamento, os espaços das extrações deveriam permanecer fechados. Contudo, muitos estudos demostraram que existe uma tendência à reabertura dos espaços de extrações em pacientes finalizados com uma oclusão adequada. O objetivo deste estudo foi comparar a estabilidade dos espaços de extrações de primeiro e segundo prémolares. A Amostra deste estudo foi composta por 72 modelos dentários dividido em dois grupos. O Grupo 1 composto por 29 pacientes (116 espaços de extração) foram tratados com extrações dos primeiros pré-molares com idade media inicial de 13,78 anos e o grupo 2 composto por 43 pacientes (100 espaços de extração) foram tratados com extrações dos segundos pré-molares com idade media inicial de 15.20 anos. Os modelos dentários obtidos no pré-tratamento, pós-tratamento e 3 a 4 anos de controle e foram digitalizados mediante um scanner 3Shape R700 3D (3Shape A/S, Copenhagen, Dinamarca). Os testes t e do Qui-Quadrado, foram utilizados para comparar o número de espaços de extração abertos e fechados após o tratamento e pós-tratamento em longo prazo. Os resultados demostraram números similares de reabertura do espaço de extração entre os grupos. Concluiu-se que considerando apenas os casos que mostraram espaços de extração completamente fechados no final do tratamento, a quantidade de reabertura dos espaços de extrações dos primeiros pré-molares ocorre mais frequentemente que dos segundos pré-molares no arco superior.

Primary Angle Closure Glaucoma (PACG) is a worldwide leading cause of irreversible blindness much more prevalent in Asia than in European-derived populations. Patterns of ethnic differences may account for prevalence variation of the disease. Recent papers have reported a predicted rise in European-derived populations. Ocular risks associated with PAC(G) include an axially small, hypermetropic eye with a large lens. Potentially, there are patients in the UK with 'at risk' ocular biometrics predisposing them to PAC(G). Biometric disparities between ethnicities infer morphological variation of PAC(G).The morphology of PAC(G) can be evaluated using ultrasound biomicroscopy (UBM) and the development of a novel linear probe has enhanced its clinical utility. UBM allows quantitative analysis of the anterior chamber, however, there are inherent difficulties in identifying the landmark scleral spur. Qualitative image analyses are urgently required to assess the morphology of closure. Clinical grading scales (CGS) have been successful in other areas within ophthalmology; their application to PAC(G) is investigated within this thesis. The specific aims of the thesis are to: a) examine biometric differences between Caucasian & Chinese patients with PAC(G); b) describe the development of a series of CGS for PAC(G) and c) validate the CGS.Biometric differences between Chinese and Caucasian sample populations exist. The Caucasian cohort exhibit typical biometric findings associated with PAC(G): significantly smaller eyes, shallower anterior chambers, larger lenses, and a significantly shorter vitreous depth, when compared to Chinese counterparts. Biometric differences lend support to variation of PAC(G) mechanisms between ethnicities. A series of clinical CGS were developed using a 'consensus' based approach. The results: utilize psychometric techniques to evaluate inter-observer error; analyse intra-observer agreement by visualising concordance; target pruning to eliminate inter-observer confusion when constructing the CGS. A new custom-made software was developed to evaluate the performance of the CGS. The results show good intra- and inter- observer repeatability to characterise the morphology of closure. This is the first study describing a comprehensive method to construct and validate CGS in PAC(G). These can be used to evaluate the morphology of closure and in the future assess the fidelity of PAC(G) management.

The European project BACCHUS (impact of Biogenic versus Anthropogenic emissions on Clouds and Climate: towards a Holistic UnderStanding) focuses on aerosol-cloud interactions. Vertical wind velocities near cloud base, and cloud condensation nuclei (CCN) spectra, are the two most important input parameters for aerosol-cloud parcel models in determining cloud microphysical and optical properties. Therefore, the present study focuses on the instrumental development for vertical wind measurements to improve aerosol-cloud closure studies. Enhancements in Remotely Piloted Aircraft Systems (RPAS) have demonstrated their potential as tools in atmospheric research to study the boundary layer dynamics, aerosols and clouds. However, as a relatively new tool for atmospheric research, RPA require instrumental development and validation to address current observational needs. A 5-hole probe is implemented on a remotely piloted aircraft (RPA) platform, with an inertial navigation system (INS) to obtain atmospheric wind vectors. The 5- hole probe is first calibrated in a wind tunnel (at Météo-France, Toulouse, France), and an error analysis is conducted on the vertical wind measurement. Atmospheric wind vectors obtained from RPA flights are compared with wind vectors determined from sonic anemometers located at different levels on a 60 m meteorological mast (Centre de Recherches Atmosphériques, Lannemezan, France). Good agreements between vertical wind velocity probability density functions are obtained. The power spectral density of the three wind components follow the -5/3 line for the established regime of turbulence (Kolmogorov law). Turbulent kinetic energy (TKE) values calculated from the RPA are somewhat higher than TKE compared to the sonic anemometer; however, the results agree with those reported in other experiments that compare RPA platforms and sonic anemometers (Lampert et al. (2016), Båserud et al. (2016)). As the RPA equipped with a 5-hole probe (defined as the ``wind-RPA'') is developed for aerosol-cloud observations, updraft velocities near cloud base are compared with cloud radar data during a BACCHUS field campaign (Mace Head Research Station, Ireland). Three case studies illustrate the similarity of in-cloud updrafts measured between the wind-RPA and the cloud radar. A good agreement between vertical velocities of both instruments over a range of different meteorological conditions is found. Updraft velocity measurements from the wind-RPA are implemented in the aerosol-cloud parcel model to conduct a closure study for stratocumulus case with convection sampled during a BACCHUS field campaign in Cyprus. Aerosol size distributions and CCN were measured at a ground-site, which served as input to the aerosol-cloud parcel model along with the updraft velocities at cloud base measured by the RPA. In addition, the RPA conducted a vertical profile through the cloud layer and measured the shortwave transmission of solar irradiance during the ascent. The aerosol-cloud parcel model also shows that entrainment has a greater impact on cloud optical properties than variability in updraft velocity and aerosol particle concentration. Results of the case study for the Cyprus field experiment are consistent with results for similar closure studies conducted during the Mace Head field campaign (Sanchez et al., 2017), and reinforce the significance of including entrainment processes in cloud models to reduce uncertainties in aerosol-cloud interactions.

This study aims to investigate the developmental ability of beginning and advance L1 English learners of Arabic to pronounce standard Arabic geminate consonants when enrolled in a full time L2 program. The results showed that English learners produced shorter closure duration when pronouncing geminates. In particular, the beginners lengthened singletons more than the advanced learners did, while both groups of learners shortened geminates much more so than native speakers of Arabic. The advanced L1 English learners of Arabic produced longer geminate duration than beginners. The ultimate result was a smaller ratio between singleton and geminate consonants in comparison to native speakers of Arabic.

La fermeture dorsale est un événement majeur de l’embryogénèse de la drosophile durant lequel les cellules les plus dorsales de l’épiderme se différencient et agissent de concert pour refermer une ouverture dorsale temporairement recouverte par l’amnioséreuse. Ce processus présente de nombreuses similarités avec la cicatrisation cellulaire. J’ai montré que les voies JNK et DPP forment une boucle cohérente appelée « feed-forward loop » (boucle d’anticipation) qui contrôle la différentiation des cellules de la marge active. La branche DPP de cette boucle filtre les signaux non désirés de la voix JNK quand les embryons sont soumis à un stress thermique. Je me suis ensuite concentré sur le câble d'actine, une structure supra-cellulaire produite par les cellules de la marge active lors de la fermeture dorsale. J’ai montré que le câble d’actine est une structure discontinue qui n’est pas nécessaire pour la fermeture dorsale ou pour la cicatrisation cellulaire. Le câble d’actine homogénéise les forces et stabilise la géométrie cellulaire pour que la fermeture se fasse de manière parfaite et sans cicatrice. Sans le câble, les cellules ont une forme irrégulière, associé à des défauts de patterning et des défauts de polarité planaire qui ressemblent aux défauts que l’on trouve lors de la formation d’une cicatrice. Nous proposons donc que le câble empêche la formation de cicatrice en « congelant » les propriétés mécaniques des cellules afin de les protéger des forces qui agissent au niveau tissulaire lors de la fermeture dorsale.En conclusion, mon travail apporte un regard neuf sur la signalisation et la morphogenèse lors de la fermeture dorsale de l’embryon de Drosophile. / Drosophila dorsal closure is a key embryonic process during which the dorsal-most epidermal cells called leading edge cells differentiate and act in a coordinated manner to close a transient dorsal hole covered by the amnioserosa in a process reminiscent of wound healing. I showed that JNK and DPP are wired in a network motif called ‘feed-forward loop’ (FFL) that controls leading edge cell specification and differentiation. The DPP branch of the FFL filters unwanted JNK activity that occurs during thermal stress. Next, I focused on the actin cable, a supra-cellular structure produced by the leading edge cells during dorsal closure or wound healing from fly to humans. My data suggest that the actin cable does not provide a major contractile force. Rather, the actin cable balances forces and stabilizes cell geometry so that closure resolves in a perfectly structured and scar-free tissue. The absence of the cable leads to cell shape irregularities as well as patterning and planar cell polarity defects that are reminiscent of scarring. We propose that the cable prevents scaring by acting as a mechanical freeze field that protects fine cellular structures from the major closure forces that operate at tissue level. Altogether, my work brings new insights on the signalling and morphogenesis during dorsal closure.

abstract: Hydraulic fracturing is an effective technique used in well stimulation to increase petroleum well production. A combination of multi-stage hydraulic fracturing and horizontal drilling has led to the recent boom in shale gas production which has changed the energy landscape of North America. During the fracking process, highly pressurized mixture of water and proppants (sand and chemicals) is injected into to a crack, which fractures the surrounding rock structure and proppants help in keeping the fracture open. Over a longer period, however, these fractures tend to close due to the difference between the compressive stress exerted by the reservoir on the fracture and the fluid pressure inside the fracture. During production, fluid pressure inside the fracture is reduced further which can accelerate the closure of a fracture. In this thesis, we study the stress distribution around a hydraulic fracture caused by fluid production. It is shown that fluid flow can induce a very high hoop stress near the fracture tip. As the pressure gradient increases stress concentration increases. If a fracture is very thin, the flow induced stress along the fracture decreases, but the stress concentration at the fracture tip increases and become unbounded for an infinitely thin fracture. The result from the present study can be used for studying the fracture closure problem, and ultimately this in turn can lead to the development of better proppants so that prolific well production can be sustained for a long period of time. / Dissertation/Thesis / Masters Thesis Mechanical Engineering 2014

abstract: A previously developed small time scale fatigue crack growth model is improved, modified and extended with an emphasis on creating the simplest models that maintain the desired level of accuracy for a variety of materials. The model provides a means of estimating load sequence effects by continuously updating the crack opening stress every cycle, in a simplified manner. One of the significant phenomena of the crack opening stress under negative stress ratio is the residual tensile stress induced by the applied compressive stress. A modified coefficient is introduced to determine the extent to which residual stress impact the crack closure and is observed to vary for different materials. Several other literature models for crack closure under constant loading are also reviewed and compared with the proposed model. The modified model is then shown to predict several sets of published test results under constant loading for a variety of materials. The crack opening stress is formalized as a function of the plastic zone sizes at the crack tip and the current crack length, which provided a means of approximation, accounting for both acceleration and retardation effects in a simplified manner. A sensitivity parameter is introduced to modify the enlarged plastic zone due to overload, to better fit the delay cycles with the test data and is observed to vary for different materials. Furthermore, the interaction effect induced by the combination of overload and underload sequence is modeled by depleting the compressive plastic zone due to an overload with the tensile plastic zone due to an underload. A qualitative analysis showed the simulation capacity of the small time scale model under different load types. A good agreement between prediction and test data for several irregular load types proved the applicability of the small time scale model under variable amplitude loading. / Dissertation/Thesis / Masters Thesis Mechanical Engineering 2016

abstract: Reynolds-averaged Navier-Stokes (RANS) simulation is the industry standard for computing practical turbulent flows -- since large eddy simulation (LES) and direct numerical simulation (DNS) require comparatively massive computational power to simulate even relatively simple flows. RANS, like LES, requires that a user specify a “closure model” for the underlying turbulence physics. However, despite more than 60 years of research into turbulence modeling, current models remain largely unable to accurately predict key aspects of the complex turbulent flows frequently encountered in practical engineering applications. Recently a new approach, termed “autonomic closure”, has been developed for LES that avoids the need to specify any prescribed turbulence model. Autonomic closure is a fully-adaptive, self-optimizing approach to the closure problem, in which the simulation itself determines the optimal local, instantaneous relation between any unclosed term and the simulation variables via solution of a nonlinear, nonparametric system identification problem. In principle, it should be possible to extend autonomic closure from LES to RANS simulations, and this thesis is the initial exploration of such an extension. A RANS implementation of autonomic closure would have far-reaching impacts on the ability to simulate practical engineering applications that involve turbulent flows. This thesis has developed the formal connection between autonomic closure for LES and its counterpart for RANS simulations, and provides a priori results from FLUENT simulations of the turbulent flow over a backward-facing step to evaluate the performance of an initial implementation of autonomic closure for RANS. Key aspects of these results lay the groundwork on which future efforts to extend autonomic closure to RANS simulations can be based. / Dissertation/Thesis / Masters Thesis Aerospace Engineering 2017

abstract: Anderies (2015); Anderies et al. (2016), informed by Ostrom (2005), aim to employ robust feedback control models of social-ecological systems (SESs), to inform policy and the design of institutions guiding resilient resource use. Cote and Nightingale (2012) note that the main assumptions of resilience research downplay culture and social power. Addressing the epistemic gap between positivism and interpretation (Rosenberg 2016), this dissertation argues that power and culture indeed are of primary interest in SES research. Human use of symbols is seen as an evolved semiotic capacity. First, representation is argued to arise as matter achieves semiotic closure (Pattee 1969; Rocha 2001) at the onset of natural selection. Guided by models by Kauffman (1993), the evolution of a symbolic code in genes is examined, and thereon the origin of representations other than genetic in evolutionary transitions (Maynard Smith and Szathmáry 1995; Beach 2003). Human symbolic interaction is proposed as one that can support its own evolutionary dynamics. The model offered for wider dynamics in society are “flywheels,” mutually reinforcing networks of relations. They arise as interactions in a domain of social activity intensify, e.g. due to interplay of infrastructures, mediating built, social, and ecological affordances (An- deries et al. 2016). Flywheels manifest as entities facilitated by the simplified interactions (e.g. organizations) and as cycles maintaining the infrastructures (e.g. supply chains). They manifest internal specialization as well as distributed intention, and so can favor certain groups’ interests, and reinforce cultural blind spots to social exclusion (Mills 2007). The perspective is applied to research of resilience in SESs, considering flywheels a semiotic extension of feedback control. Closer attention to representations of potentially excluded groups is justified on epistemic in addition to ethical grounds, as patterns in cul- tural text and social relations reflect the functioning of wider social processes. Participatory methods are suggested to aid in building capacity for institutional learning. / Dissertation/Thesis / Doctoral Dissertation Anthropology 2017