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1.
  • Larsson, Anders, 1977- (författare)
  • Androgen receptors and endocrine disrupting substances
  • 2010
  • Doktorsavhandling (övrigt vetenskapligt)abstract
    • Throughout the animal kingdom, organisms are dependent on substances such as steroid hormones to help them maintain internal balances. Examples of important tasks that are under regulation of steroid hormones are somatic and gonadal development, sexual performance and behavior (both social and sexual) as well as sex differentiation. Balance in the biology of reproduction is important for all organisms, and is sensitive to alterations and disturbances. If the environment is altered in a manner that lead to higher estrogenic or androgenic levels, the sex ratio of organisms that do not rely on genetic differences in the sex differentiation, will be biased towards more females or males in the population. It has been known for some time that there are pollutants in the environment that affect steroid pathways, such as the estrogenic and thyroid systems, but not much has been known about the androgenic systems. Examples of populations being masculinized have been recorded, and estrogenic compounds have been known to act as antiandrogens, but not until recently the first androgen agonist was identified. We used a combination of in vitro and computational modeling to identify the brominated flame retardant, 1,2-dibromo-4-(1,2-dibromoethyl)cyclohexane, as a potent androgen agonist to the human androgen receptor.In addition to this we cloned and characterized the androgen receptor from, a frequently used model organism, zebrafish (Danio rerio) as a receptor primarily activated by 11-ketotestosterone. This is a feature the zebrafish share with several other teleost fishes, such as the three-spined stickleback. Thus fish androgen receptors differ from most mammalian androgen receptors, where dihydrotestosterone is the most potent activator. 
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2.
  • Larsson, Anders, 1954- (författare)
  • Att vara – tillsammans
  • 2011
  • Doktorsavhandling (övrigt vetenskapligt)abstract
    • This thesis is focused on two phenomena: normative citizenship ideals and onto-logical notions of man. The study is an inductive search for different attributes to describe a variation of these phenomena. The search is conducted from several different perspectives: Current research within citizenship theory, history in a material sense, the history of political ideas, the philosophy of science and thematic analyses of important aspects of the two phenomena.Throughout the thesis attributes are collected and sorted in order to build typologies that can define the variation.In the end the attributes of normative citizenship ideals are sorted into three groups. The ideals are explained in three ways: why they came in to existence, how the transition from one ideal to another took place and how the idealistic content of the ideals were transformed.The attributes of ontological notions of man are sorted into sex types and four of them are defined to have relevance for an existing variation today.Finally the relations between the two typologies are analyzed and ten combinations are found to be possibly useful in studies of contemporary societal contexts.Together, the results are contributing to theories of citizenship.Apart from the results of the study it is argued for a broader definition of politics in political science, for more specific ways to handle egalitarian questions in the field rights of man / citizenship rights and finally against the possibility of a neutral order, for example a neutral state.
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4.
  • Larsson, Anders (författare)
  • Inhibited electrical discharges in air
  • 1997
  • Doktorsavhandling (övrigt vetenskapligt)abstract
    • Modem society requires a stable electricity supply, the reliability of which is partlydetermined by the dielectric strength of the outdoor high-voltage insulation systems.This thesis concentrates upon one particular discharge phenomenon that occurs whensuch a system is subjected to rain, namely the inhibited discharge. This is a dischargewhere the energy input into the discharge channel is limited by the presence of a largeseries resistor in the discharge circuit.Two experimental arrangements have been used: A quasi-uniform 10 mm electrodegap (simulating discharges between water drops) and a rod-to-plane 1 m electrode gap(simulating the flashover of a high-voltage post insulator).The presence of the series resistance caused no increase in the disruptive dischargevoltage for the 10 mm gap, but for the 1 m gap it induced an increase that was morepronounced for negative than positive polarity.The transition from a cold discharge to a hot plasma was significantly prolongedwhen a large series resistance was introduced in the discharge circuit. This is interestingfor engineering purposes since it increases the time window in which action can betaken before the end of the disruptive discharge.A five order-of-magnitude difference in the peak streamer-to-spark transition current(1 mA - 100 A) was found in the literature for 10 mm gaps. This difference has notbeen thoroughly investigated previously. Here an explanation is suggested for thisphenomenon.The experimental results revealed that the streamer propagation was not inhibited bythe presence of a large series resistance in the discharge circuit, but the final jump was.The effect upon streamer propagation was confirmed by calculations using a well-established streamer model. A final-jump model was derived as part of the work presented here and good agreement was obtained between the experiments and the calculations. This model should be useful in the design of high-voltage insulators.
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5.
  • Larsson, Anders Olof, 1979- (författare)
  • Doing Things in Relation to Machines
  • 2012
  • Doktorsavhandling (övrigt vetenskapligt)abstract
    • The Internet is often discussed in conjunction with various notions of interactivity. Recently, conceptualizations of a “Web 2.0″, mainly focusing on harnessing user-generated content, have grown increasingly common in both public discourse and among researchers interested in the continued growth and transformation of the Internet.This thesis approaches the use and non-use of online interactive features by societal institutions. Specifically, the thesis focuses on online newspapers and online political actors, studying the practitioners working within those institutions and on their respective audiences. Consisting of four empirical studies, the thesis is informed theoretically by the application of conceptual tools pertaining to structuration theory. In Anthony Giddens’ original conception, structuration theory posits that social structure is recursively shaped (and possibly altered) as human agents choose to re-enact certain modalities of specific structures. By changing their uses of the rules and resources made available to them by structure, humans are given agency in relation to overarching, macro-level structures. Giddens’ writings have also been contextualized to the study of information technology use by Wanda Orlikowski, who has mostly focused on organizational research.Combining insights from Giddens and Orlikowski, the thesis suggests that most Internet users are enacting a “structure of audiencehood”, entailing somewhat traditional consumer behavior, rather than a “structure of prosumerism”, which would entail extensive uses of the interactive features made available online. Similar traditional use patterns are discerned for practitioners. The thesis suggests that we should not be surprised at relatively low levels of use of interactive features by practitioners and audiences in these contexts. While the chosen areas of study are often surrounded by expectations and “hype” regarding the consequences of online interactivity, institutionalized news and politics can be said to represent stable structures – structures that have functioned in similar ways for extended periods of time, and, thus, are not so easily amended.
6.
  • Larsson, Anders, 1961- (författare)
  • Proximity Matters? Geographical aspects of changing strategies in automotive subcontracting relationships:the case of domestic suppliers to Volvo Troslanda assembly plant.
  • 1999
  • Doktorsavhandling (övrigt vetenskapligt)abstract
    • This study analyses the significance of geographical proximity in the restructuring process of a domestic subcontractor system in the Swedish automotive industry, using the Volvo Torslanda assembly plant as a case. The focus is on: i) the organisation of buyer-subcontractor relationships, ii) time-related delivery strategies, iii) the significance of geographical proximity. The findings provide an empirical contribution to the general understanding of the geographical buyer- subcontractor relationships in the automotive industry. The case covers the development of the domestic subcontractor system in the 1990s and is subdivided into three parts: i) the 40 most important domestic subcontractors in 1996/97, ii) the development of the Arendal supplier-park project 1997-1998, and iii) an analysis of Hydro- Raufoss Automotive Plastics AB, a Norwegian subcontractor, 1993-1998. Up until 1996/97 geographical proximity played a marginal role in the organisation of domestic subcontracting. The system was in the initial stage of an organisational restructuring, showing the first signs of an emerging subcontractor hierarchy. The average delivery frequency increased from weekly to daily deliveries during the 1990s, facilitated by a good infrastructure. Proximity became an important strategic factor with the development of the S80-model, launched in 1998. The main reason was the accelerating use of sequential production on the Volvo assembly line, which directly integrated the production processes of Volvo and its subcontractors. To better respond to the tight time schedule, a number of subcontractors established operations in the new Volvo-led supplier-park, five minutes from the assembly plant. In the introductory phase, there were no explicit plans for subcontractor co-operation. Instead, the park served as a Odelivery-pointO where incoming components were sorted in sequence and delivered to Volvo on an hourly basis. An exception to this was Hydro-Raufoss, which had developed from a delivery-warehouse into a complete production unit. The launch of new models offers an opportunity to implement structural changes in the subcontractor system. Whether the recent change in VolvoOs ownership will also have a bearing on this is, however, a moot point.
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8.
  • Larsson, Anders (författare)
  • Systematics of Woodsia
  • 2014
  • Doktorsavhandling (övrigt vetenskapligt)abstract
    • Ferns are one of the three main clades of vascular plants. They have few easily studied morphological characters, reflected in a historically unstable classification. The fern genus Woodsia is known to have a complex evolutionary history including numerous polyploid taxa and hybrids. It is a cosmopolitan group of small rock loving ferns mainly found in montane areas.This thesis aims at analyzing the patterns of diploid and polyploid evolution in Woodsia and to resolve and classify the relationships of Woodsiaceae and the other families in the large fern clade Eupolypods II.The Eupolypods II family relationships were inferred with DNA sequences from 81 specimens representing all major lineages. This resulted in the first well supported phylogeny of this clade and revealed Woodsiaceae to be non-monophyletic. The genera previously placed in this family were reclassified into five new or resurrected families. Swedish fern genera that have changed family classification are Woodsia (hällebräknar), now in the monogeneric family Woodsiaceae, Athyrium (majbräknar), now  in Athyriaceeae and Cystopteris (stenbräknar) and Gymnocarpium (ekbräknar) now in Cystopteridaceae.To analyze the evolution of Woodsia, phylogenies were produced from five plastid and two nuclear regions sequenced from 188 specimens. The results show that most taxa in Woodsia are polyploid. Polyploidization is the most common mode of speciation in the genus with an estimated polyploid speciation rate of 54%. The polyploids are mostly young and many of the polyploid taxa seem to have formed multiple times. The results also address several taxonomic and biogeographic questions.In the process of the work we made methodological advancements and developed 20 new low copy nuclear marker regions as well as a software pipeline for finding primers in transcriptome datasets. The alignment editor software AliView was developed for handling the increasing size datasets in a user friendly way.In conclusion this thesis provides new insights into the complexities of the evolution of a fern genus in which much of the diversity is accommodated in young species formed through polyploidization. It provides a framework of phylogenetic relationships at different levels that both answers long standing questions and generates new ones.
9.
  • Larsson, Anders, 1977- (författare)
  • Test Optimization for Core-based System-on-Chip
  • 2008
  • Doktorsavhandling (övrigt vetenskapligt)abstract
    • The semiconductor technology has enabled the fabrication of integrated circuits (ICs), which may include billions of transistors and can contain all necessary electronic circuitry for a complete system, so-called System-on-Chip (SOC). In order to handle design complexity and to meet short time-to-market requirements, it is increasingly common to make use of a modular design approach where an SOC is composed of pre-designed and pre-verified blocks of logic, called cores.Due to imperfections in the fabrication process, each IC must be individually tested. A major problem is that the cost of test is increasing and is becoming a dominating part of the overall manufacturing cost. The cost of test is strongly related to the increasing test-data volumes, which lead to longer test application times and larger tester memory requirement. For ICs designed in a modular fashion, the high test cost can be addressed by adequate test planning, which includes test-architecture design, test scheduling, test-data compression, and test sharing techniques.In this thesis, we analyze and explore several design and optimization problems related to core-based SOC test planning. We perform optimization of test sharing and test-data compression. We explore the impact of test compression techniques on test application time and compression ratio. We make use of analysis to explore the optimization of test sharing and test-data compression in conjunction with test-architecture design and test scheduling. Extensive experiments, based on benchmarks and industrial designs, have been performed to demonstrate the significance of our techniques.
10.
  • Larsson, Anders (författare)
  • On high-frequency distortion in low-voltage power systems
  • 2011
  • Doktorsavhandling (övrigt vetenskapligt)abstract
    • Power quality is a subject that has received a lot of attention during the last 10 to 20 years, both in industry and in academia. Power quality concerns interaction between the power grid and its customers and between the power grid and equipment connected to it, reflected in voltages and currents. Research and other developments in this area have to a great extent concentrated on relatively slow and low-frequency phenomena, with the main emphasis being on voltage dips (reductions in voltage magnitude with duration between about 50 ms and several seconds) and low-frequency harmonics (waveform distortion by frequency components up to about 2 kHz). These phenomena are reasonably well understood and several standards cover the area. For higher-frequency phenomena, above 2 kHz, there is no such general understanding, nor is there anything close to a complete set of standards covering this area. Modern energy efficient equipment connected to the grid, like fluorescent lamps but also solar panels, often uses switching technology, with switching frequencies that can range from a couple of kHz up to several hundreds of kHz. The grid is also used for communication of e.g. meter readings, system controls etc. This so-called power-line communication is using the same frequency range. The main frequency range of interest for this thesis has been the range from 2 to 150 kHz. There are two completely different measurement methods covering this frequency range: time-domain based and frequency-domain based. Time domain based measurements are used throughout the thesis. This gives an opportunity to choose between different analysing tools where among others the joint time-frequency domain has shown to be a useful tool for describing waveform distortion in our frequency range of interest. The majority of the measurements presented in this thesis have been directed towards fluorescent light powered by high frequency ballasts. This type of load has been, due to stringent harmonic limits, one of the first to use a more advanced switching technology called active power factor correction. This technique is also getting more frequently used in other small-power equipment, like computers. Installations of lights in stores etc. normally contain a large number of ballast connected together and the interaction is of importance, for example for setting emission and immunity standards. The measurements on ballasts presented in this work have shown that distortion in the frequency rage 2-150 kHz comes in three types: narrowband distortion; wideband distortion; and recurrent oscillations. The recurrent oscillations are a new type of powerquality disturbance that had not been recognized as such before. The measurements further have shown that the three types of distortion spread in a completely different way from the individual devices to the grid. This knowledge is essential for the setting of emission requirements on energy-efficient equipment.
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