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La télomérase est essentielle pour le maintien des télomères. Elle compense le problème de réplication de l’ADN télomérique par l’ajout de séquences d’ADN aux extrémités des chromosomes. Chez l’humain, elle est très active dans les premiers stades du développement (embryon, fœtus). Puis, son activité est réprimée pour devenir indétectable dans la plupart des cellules. Ceci conduit au raccourcissement de l’ADN télomérique, à la déprotection de l’ADN et à un arrêt de division cellulaire, appelé senescence. Par contre, dans 90% des cellules de type cancéreux, elle est suractivée. Elle contribue donc à une capacité continue de la prolifération de ces cellules et à leur immortalisation. Notre organisme d’étude est la levure bourgeonnante, Saccharomyces cerevisiae. En plus de ses nombreux avantages d’utilisation, chez cette levure, la télomérase est exprimée constitutivement, ce qui signifie qu’elle nous rapproche le plus du contexte de cellule cancéreuse. Mon projet de maîtrise vise à étudier un des composants de la télomérase chez la levure S. cerevisiae, c’est-à-dire la sous-unité ARN, appelée Tlc1, et plus particulièrement une sous-partie de cet ARN, formant une jonction à trois branches (« Three Way Junction »). Jusqu’à présent, cette structure a été considérée comme étant non essentielle. Pourtant, cette structure très conservée a été démontrée comme étant essentielle à l’assemblage de la télomérase et à son activité, chez une grande variété d’espèces. Avec ce projet, j’ai tenté de déterminer si cette structure à trois branches a un quelconque rôle à jouer que ce soit dans l’assemblage ou dans l’activité de la télomérase. J’ai exploré cette structure en y réalisant des mutations et en analysant leurs effets sur la croissance cellulaire et sur la longueur des télomères. Parmi tous les mutants, la simple substitution d’un nucléotide spécifique, l’adénine 119, conduit à des télomères plus courts qui demeurent stables au fil des générations et les levures sont viables. De plus, ce raccourcissement est de l’ordre de la centaine de paires de bases lorsque la délétion d’une partie ou de la structure au complet est réalisée. C’est donc un raccourcissement significatif, représentant près d’un tiers de la longueur normale des télomères. Par ailleurs, sur des cellules présentant des télomères anormalement courts, l’ajout de ces mutations de la TWJ de TLC1 crée un phénotype létal. / Abstract : Telomerase is essential for telomere maintenance. It compensates for the End-replication problem by adding DNA sequences to the ends of chromosomes. In humans, telomerase is very active in the early stages of development (embryos, foetus). Later, its activity is repressed, and in most cells its activity becomes undetectable. This leads to telomere shortening, a deprotection of chromosome ends and to an arrest of cellular divisions, a highly regulated process also called cellular senescence. However, in cancer cells of 90% of all subtypes, telomerase is up-regulated. Hence, this enzyme promotes the proliferative capacity of cancer cells and their immortalization. The budding yeast Saccharomyces cerevisiae is our organism of study. In addition to its ease of access, telomerase is constitutively expressed in this yeast, which makes it a useful and inexpensive model of cancer cells. My master’s project aims at studying one of the telomerase components in S. cerevisiae, namely the RNA subunit Tlc1, and more specifically a part of this RNA, forming a Three-Way Junction (TWJ). So far, this structure was considered as non-essential for cell viability. However, this structure is highly conserved among species, and in diverse species it was shown to be crucial for telomerase assembly and activity. My project hence consisted in trying to determine whether or not this structure plays a role in telomerase assembly or activity. The requirements on this structure were explored by creating mutations and by analyzing their effects on cell growth and telomere length. Of all the mutants, a specific nucleotide substitution, Adenine 119 in the TWJ, leads to shortened telomeres, and this shortening is stable during further outgrowth. Furthermore, a telomere shortening of up to 100 base pairs is observed when a part or the complete TWJ structure is deleted. This shortening is quite significant as it represents about one third of the normal length of telomeres. Moreover, expressing these mutants of the TWJ in cells with short telomeres creates a synthetic lethal effect.

京都大学 / 0048 / 新制・課程博士 / 博士(エネルギー科学) / 甲第17795号 / エネ博第278号 / 新制||エネ||58(附属図書館) / 30602 / 京都大学大学院エネルギー科学研究科エネルギー社会・環境科学専攻 / (主査)教授 石原 慶一, 教授 東野 達, 准教授 奥村 英之 / 学位規則第4条第1項該当 / Doctor of Energy Science / Kyoto University / DFAM

A spark ignition engine was retrofitted to operate on biogas fuel. Biogas was synthetically generated through the mixing of various pure gases. The air-fuel ratio was accurately controlled using a closed feedback system consisting of flow controllers and a wide range oxygen sensor. A natural gas catalytic converter was implemented with the use of biogas fuel. To achieve full NOx and CO reduction the engine was required to run at a slightly rich equivalence ratio. Methane emissions posed to be the hardest to reduce across the catalyst. The biogas fuel composition had no effect on the catalyst performance. The catalyst performance was only affected by exhaust temperature and equivalence ratio. The catalyst requires tight A/F ratio control for optimal performance. A Catalytic converter can be used to reach low emissions but requires the knowledge of the biogas fuel composition.

A spark ignition engine was retrofitted to operate on biogas fuel. Biogas was synthetically generated through the mixing of various pure gases. The air-fuel ratio was accurately controlled using a closed feedback system consisting of flow controllers and a wide range oxygen sensor. A natural gas catalytic converter was implemented with the use of biogas fuel. To achieve full NOx and CO reduction the engine was required to run at a slightly rich equivalence ratio. Methane emissions posed to be the hardest to reduce across the catalyst. The biogas fuel composition had no effect on the catalyst performance. The catalyst performance was only affected by exhaust temperature and equivalence ratio. The catalyst requires tight A/F ratio control for optimal performance. A Catalytic converter can be used to reach low emissions but requires the knowledge of the biogas fuel composition.

Doctor of Philosophy / Department of Chemical Engineering / Keith L. Hohn / Extensive research has gone into developing and modeling the three-way catalyst (TWC) to reduce the emissions of hydrocarbons, NOx and CO from gasoline-fueled engines level. However, much less has been done to model the use of the three-way catalyst to treat exhaust from natural gas-fueled engines. Our research address this gap in the literature by developing a detailed surface reaction mechanism for platinum based on elementary-step reactions. A reaction mechanism consisting of 24 species and 115 elementary reactions was constructed from literature values. All reaction parameters were used as found in the literature sources except for steps modified to improve the model fit to the experimental data. The TWC was simulated as a one-dimension, isothermal plug flow reactor (PFR) for the steady state condition and a continuous stirred-tank reactor (CSTR) for the dithering condition. This work describes a method to quantitatively simulate the natural gas engine TWC converter performance, providing a deep understanding of the surface chemistry in the converter. Due to the depletion of petroleum oil and recent volatility in price, synthesizing value-added chemicals from biomass-derived materials has attracted extensive attention. 1, 3-butadiene (BD), an important intermediate to produce rubber, is conventionally produced from petroleum. Recently, one potential route is to produce BD by dehydration of 2, 3-butanediol (BDO), which is produced at high yield from biomass. This reaction was studied over two commercial forms of alumina. Our results indicate acid/base properties greatly impact the BD selectivity. Trimethylamine can also modify the acid/base properties on alumina surface and affect the BD selectivity. Scandium oxide, acidic oxide or zirconia dual bed systems are also studied and our results show that acidic oxide used as the second bed catalyst can promote the formation of BD, while 2,5-dimethylphenol is found when the zirconia is used as the second bed catalyst which is due to the strong basic sites.

A one dimensional discretized model of a two brick three way catalyst (TWC) system was developed and implemented in MATLAB, Simulink and TargetLink in collaboration with Volvo Cars and Linköpings Universitet - ISY. The purpose of this thesis was to increase system understanding and create a model based TWC control for further development at Volvo Cars. A total of 50 states were modelled, including emission concentrations (O2, CO, C3H6, C3H8, H2, NOx, CO2, H2O), temperature and oxygen buffer level (OBL). A model based control structure was implemented in the form of five separate PID-controllers enabling possibilities to control the OBL of each separate slice of each brick individually and through simple reference handling. The control structures includes anti-windup, feedforward control and feedback safety for model reset during sensor indication of leakage. Specific equipment and software used included MATLAB, Simulink, TargetLink, Volvo SULEV30 TWC and testing rigs. Overall increase in system understanding was achieved in comparison with contemporary TWC modelling and control, as well as sufficient system performance in regard to estimate emissions, simulation duration and pedagogical value. Concluding thoughts of the thesis revolve the complexity of the actual TWC modelling, parameter estimation as well as control. The model presented in this thesis has great potential of describing TWC systems but with great effort during parameter estimation. With ECU performance available in temporary vehicle production year 2019, a complex model may be combined with a simple control strategy whilst a simple model may be combined with a complex control strategy.

Madurese, a Western Malayo-Polynesian language spoken on the Indonesian island of Madura, exhibits a three-way laryngeal contrast distinguishing between voiced, voiceless unaspirated and voiceless aspirated stops and an unusual consonant-vowel (CV) co-occurrence restriction. The CV co-occurrence restriction is of phonological interest given the patterning of voiceless aspirated stops with voiced stops rather than with voiceless unaspirated stops, raising the question of what phonological feature they may share. Two features have been linked with the CV co-occurrence restriction: Advanced Tongue Root [ATR] and Lowered Larynx [LL]. However, as no evidence of voicing during closure for aspirated stops is observed and no other acoustic measures except voice onset time (VOT), fundamental frequency (F0), frequencies of the first (F1) and the second (F2) formants and closure duration relating to the proposed features have been conducted, it remains an open question which acoustic properties are shared by voiced and aspirated stops. Three main questions are addressed in the thesis. The first question is what acoustic properties voiced and voiceless aspirated stops share to the exclusion of voiceless unaspirated stops. The second question is whether [ATR] or [LL] accounts for the patterning together of voiceless aspirated stops with voiced stops. The third question is what the implications of the results are for a transparent phonetics-phonology mapping that expects phonological features to have phonetic correlates associated with them. In order to answer the questions, we looked into VOT, closure duration, F0, F1, F2 and a number of spectral measures, i.e. H1*-A1*, H1*-A2*, H1*-A3*, H1*-H2*, H2*-H4* and CPP. We recorded fifteen speakers of Madurese (8 females, 7 males) reading 188 disyllabic Madurese words embedded in a sentence frame. The results show that the three-way voicing categories in Madurese have different VOT values. The difference in VOT is robust between voiced stops on the one hand and voiceless unaspirated and voiceless aspirated stops on the other. Albeit statistically significant, the difference in VOT values between voiceless unaspirated and voiceless aspirated stops is relatively small. With regard to closure duration, we found that there is a difference between voiced stops on the one hand and voiceless unaspirated and aspirated stops on the other. We also found that female speakers distinguish F0 for the three categories while male speakers distinguish between F0 for voiced stops on the one hand and voiceless unaspirated and voiceless aspirated stops on the other. The results for spectral measures show that there are no significant differences in H1*-A1*, H1*-A3*, H1*-H2*, H2*-H4* and CPP between vowels adjacent to voiced and voiceless aspirated stops. In contrast, there are significant differences in these measures between vowels adjacent to voiced and voiceless unaspirated stops and between vowels adjacent to voiceless aspirated and voiceless unaspirated stops. Regarding the question whether voiced and voiceless aspirated stops share certain acoustic properties, our findings show that they do. The acoustic properties they share are H1*-A1* for both genders, H1*-H2* for females, H1*-A3* and H2*-H4* for males, and CPP for females at vowel onset and for males at vowel midpoint. However, they do not share such acoustic properties as VOT, closure duration and F0. Voiceless unaspirated and voiceless aspirated stops can be distinguished by VOT, F0 and spectral measures, i.e. H1*-A1*, H1*-A3*, H1*-H2*, H2*-H4* and CPP. However, these two voiceless stop categories have similar closure durations. As regards the question if [+ATR] or [+LL] might be responsible for the patterning together of voiceless aspirated stops with voiced stops, our findings suggest that either feature appears to be plausible. Acoustic evidence that lends support to the feature [+ATR] includes lower F1 and greater spectral tilt measures, i.e. H1*-A1*, H1*-A3*, H1*-H2* and H2*-H4*, and lower CPP values. Acoustic evidence that supports the feature [+LL] includes lower F1 and greater spectral tilt measures, i.e. H1*-A1*, H1*-A3*, H1*-H2* and H2*-H4*, and lower CPP values. However, the fact that voiceless aspirated stops are voiceless during closure raises a problem for the feature [+ATR] and the fact that F0 for voiceless aspirated stops is higher than for voiced stops also presents a problem for the feature [+LL]. The fact that not all acoustic measures fit in well with either feature is problematic to the idea that the relationship between phonetics and phonology is transparent in the sense that phonological features can be directly transformed into their phonetic correlates. Following the view that not all phonological features may not be expected to be phonetically grounded, for example, when they are related to historical sound change, we hold the idea of a phonetics-phonology mapping which allows for other non-phonetic factors to account for a phonological phenomenon. We also provide historical and loanword evidence which could support that voiceless aspirated stops in Madurese may have derived from earlier voiced stops, which probably retain their historical laryngeal contrast through phonologisation.

The need for aggregating privacy policies is present in a variety of application areas today. In traditional client/server models, websites host services along with their policies in different private domains. However, in a cloud-computing platform where aggregators can merge multiple services, users often face complex decisions in terms of choosing the right services from service providers. In this computing paradigm, the ability to aggregate policies as well as services will be useful and more effective for users that are privacy conscious regarding their sensitive or personal information. This thesis studies the problems associated with the Platform for Privacy Preference (P3P) language, and the present issues with communicating and understanding the P3P language. Furthermore, it discusses some efficient strategies and algorithms for the matching and the merging processes, and then elaborates on some privacy policy conflicts that may occur after merging policies. Lastly, the thesis presents a tool for matching and merging P3P policies. If successful, the merge produces an aggregate policy that is consistent with the policies of all participating service providers.

Background and Problem definition: Atypical employment is something that has becomeincreasingly common in recent decades, these are defined as positions where no relationship is of thetraditional type in which the employee has a long term relationship with the employer and where hecarries out his work at the premises of the employer. These atypical employments can take variousforms, it can be fixed term contracts, project work or jobs in employment agencies and so on. Thestaffing sector in Sweden has grown rapidly since the 90s, and since international research shows thatthe three-way relationship arising from the use of staffing agencies may lead to challenges in differentparts of HRM, we have chosen to study this topic. Aim: The purpose of this paper is to describe and understand how HRM is handled in atypicalemployment relationships.Method: The epistemological starting point for this work is hermeneutics, as a result of this theresearch approach is qualitative and inspired by abduction. The authors have chosen to carry out thework as a case study of three primary cases, each one consisting of an employment agency, a clientorganization and an employee. The analysis is based on the hermeneutics principles of interpretationand concentration of meaning. Results: What emerged as central to how HRM is handled are the interdependencies that existbetween the business environment and the strategies of the firm, how they affect different parts ofHRM and how participation and liminality have an impact on the three-way relationship.Keywords: HRM, atypical employment, staffing agencies, three-way relationship and strategy. / Bakgrund och Problematisering: Atypiska anställningsförhållanden är något som har blivit meroch mer vanligt förekommande de senaste decennierna, dessa definieras som anställningar där interelationen är av den traditionella typen där den anställde har en långsiktig relation med arbetsgivarenoch där denne utför sitt arbete på plats hos arbetsgivaren. Dessa atypiska anställningsförhållanden kanta sig olika uttryck, det kan vara olika visstidsanställningar, arbete i projektform eller anställningar ibemanningsföretag och så vidare. Bemanningsbranschen i Sverige har vuxit i snabb takt sedan 90-talet, och då internationell forskning visar på att det trepartsförhållande som uppstår vid användandetav bemanningsföretag kan leda till utmaningar när det gäller olika delar av HRM har vi valt dettaämne att studera. Syfte: Syftet med detta arbete är att beskriva och förstå hur HRM hanteras i atypiskaanställningsförhållanden.Metod: Den epistemologiska utgångspunkten för detta arbete är hermeneutiken, som en följd avdetta är forskningsansatsen kvalitativ och inspirerad av abduktion. Författarna har valt att genomföraarbetet som en fallstudie bestående av tre primärfall som var och ett består av ett bemanningsföretag,en kundorganisation och en anställd. Analysen bygger på hermeneutikens tolkningsprinciper ochmeningskoncentrering. Resultat: Det som framkommit som centralt för hur HRM hanteras är de ömsesidigaberoendeförhållanden som föreligger mellan företagens förutsättningar och strategier, hur dessapåverkar olika delar av HRM och hur delaktighet och liminalitet har inverkan på trepartsförhållandet.Sökord: HRM, atypiska anställningsförhållanden, bemanningsföretag, trepartsförhållande och strategi.