Syftet med studien var att undersöka hur känsla av sammanhang (KASAM) påverkas i vuxenlivet hos individer som farit illa i barndomen. Tidigare forskning tydliggör vilken omfattande problematik det kan vara. Vidare undersöker studien betydelsen av vändpunkter och motståndskraft för posttraumatiskt växande. Den kvalitativa metoden består av sex semistrukturerade intervjuer. Den kvantitativa metoden innefattar en webbenkät där 101 respondenter deltog. Antonovskys KASAM tillsammans med Mays existentialism och Honneths erkännandeteori lägger grunden för studiens teoretiska ansats. Resultatet visar att en förlust av grundtillit och egenvärde i barndomen leder till en svag känsla av sammanhang. Urvalsgruppens KASAM-värden var avsevärt lägre än normalbefolkningens, dock med hög meningsfullhet. I vuxenlivet tycks det viktigt att ta igen barndomens förluster. Samtalsstöd med ett salutogent synsätt kan kompensera för denna förlust. Det tillsammans med meningsskapande processer kan leda till posttraumatiskt växande. / The aim of this study was to examine how sense of coherence (SOC) is affected in adulthood in people who have suffered from adverse childhood experiences. Previous research indicate on how comprehensive of a problem this is. We also wanted to examine the impact of turning points and resilience for posttraumatic growth. The qualitative method consists of six semi- structured interviews. The quantitative method is composed of a web survey in which 101 respondents participated. Antonovsky's SOC together with May's existentialism and Honneth's theory of recognition lays the foundation for the study's theoretical approach. The result shows that a loss of basic trust and intrinsic value in childhood leads to a low sense of coherence. Participants SOC values was significantly lower than the normal population, however they scored high on meaningfulness. In adulthood it seems important to reclaim these losses from childhood. Different types of counseling with a salutogenic approach can make up for that loss. This, together with meaning-making, can lead to posttraumatic growth.

Brottsligheten i Sverige har ökat. Två av fem individer återfaller i brott efter frigivning. De individer som lever i utanförskap och kriminalitet är i en utsatt position. Flertalet av kriminalvårdens klienter har behov av insatser från olika verksamheter för att klara sig från återfall i kriminalitet. Syftet med studien är att få en djupare förståelse om vad före detta kriminella anser har varit betydelsefullt i deras process att lämna sin kriminella livsstil. Syftet är även att belysa vilken inverkan kriminalvården och socialtjänstens insatser har utgjort i denna process. De frågeställningar som studien ämnar besvara är: Vad har varit betydelsefullt för att kunna lämna den kriminella livsstilen? Vilken betydelse har insatser från kriminalvården utgjort i processen att lämna den kriminella livsstilen? Vilken betydelse har insatser från socialtjänsten utgjort i processen att lämna den kriminella livsstilen? För att besvara dessa frågor har vi använt oss av en kvalitativ ansats. Åtta semistrukturerade intervjuer har genomförts med medlemmar från KRIS och X-cons. Resultatet har analyserats utifrån teorin om sociala band samt tidigare forskning inom den valda studiens område. Det informanterna har uppgett som mest betydelsefullt är att känna ett sammanhang och meningsfullhet till sådant som sysselsättning, fritid och sociala relationer. Det som också har haft betydelse är de vändpunkter som informanterna har kommit i kontakt med. Dessa har varit sådant som fängelsestraff, försämrad hälsa, kontakt med föreningar och insatser från kriminalvården och socialtjänsten som sedan lett dem till insikt och möjlighet till förändring av deras livssituation. / Crime in Sweden has increased. Two out of five individuals reoffend after release from prison. Those individuals who are living in alienation and crime are in a vulnerable position. Most of the prison service and probation clients are in need of support from various authorities in order to desist from crime. The aim of this study is to gain a deeper understanding of what ex-criminals think has been important in their process to leave their criminal lifestyle. It also aims to view the impact of prison service and probation and social services support in this process. The questions which the study intends to answer are: What has been important to be able to leave the criminal lifestyle? How important has the efforts of the prison and probation service been in the process of leaving the criminal lifestyle? How important has the efforts of social services been in the process of leaving the criminal lifestyle? To answer these questions, we used a qualitative approach. Eight semi-structurerd interviews were conducted with members of KRIS and X-cons. The results have been analyzed according to the theory of social bonds and previous research of the selected study field. The informants have indicated that the most important factor is to feel a connection and meaningfulness such as employment, leisure and social relationships. What also played an important role were the turning points that the informants have come in contact with. These have been such as a prison sentance, impaired health, contact with organizations and efforts of prison and probation service and social services which then led them to the knowledge and ability to change their lives.

I denna studie har fyra biografier/självbiografier producerade av tidigare kriminella tematiskt analyserats. Målet var att ta reda på vilka omständigheter som gör att individer går från kriminalitet till laglydighet. Genom en överblick av tidigare forskning, utökades studiens fokus med att inkludera teorier som kontrollteori och genusteori. Genom studiens resultatanalys identifierades sju olika teman, som var betydande för deltagarna: barn, relationer, mognad & identitet, arbete & annat engagemang, religion, tilltro samt betydelse av fängelsestraffet. Egna och andras barn skapar motivation till förändring, goda relationer bidrar med förändrade attityder till brottslighet, mognad och identitet bidrar med utveckling mot ett annat sätt att förhålla sig till sig själv och brottslighet, arbete och engagemang stärker självförtroendet i kunskap om att andra möjligheter finns, religion bidrar med styrka och tröst i svåra stunder, tilltro ger stöd och förebilder och fängelsestraffet ger tid för eftertanke och erfarenheter. / In this study, four biographies/autobiographies produced by former criminals have been thematically analysed. The goal was to find out what circumstances make individuals go from criminality to law-abiding. Through an overview of previous research, the focus of the study was expanded to include theories such as control theory and gender theory. Through the study's result analysis, seven different themes were identified, which were significant for the participants: children, relationships, maturity & identity, work & other commitment, religion, faith and the meaning of the prison sentence. Own and other people's children create motivation for change, good relationships contribute to changing attitudes to crime, maturity and identity contribute to development towards a different way of relating to oneself and crime, work and commitment strengthen self-confidence in the knowledge that other opportunities exist, religion contributes with strength and comfort in difficult moments, faith provides support and role models and the prison sentence gives time for reflection and experiences.

The entrance of women into ordained ministry positions is a relatively new phenomenon in the North American Christian church, and has yet to be given adequate scholarly attention. This thesis probes the experiences of several pioneering women, presenting both the substantial and theoretical contributions emerging from a qualitative study of female pastors ministering in Protestant congregations across Canada. Data collection and analysis were approached through the lens of symbolic interactionism and grounded theory. The main findings emerging from 44 qualitative, in-depth interviews have been organized into three distinct papers to constitute a sandwich dissertation. The first paper outlines how some women experience a “call” to ministry and how this change in trajectory impacts their identity and constructions of the past, while the second two papers address different facets of performing the pastoral role once within it. Paper 2 explores the dilemmas women encounter in the area of clothing and appearances, a concern many of the women identified as influencing their performance of the pastoral role. Paper 3 explores in greater depth the ways women feel they perform the pastoral role differently than their male counterparts, and raises questions about the impact this may have on changing the role in the future. Taken together, the three papers contribute to a broad range of debates in the theoretical literature about key facets of the human experience, including: changing career trajectories, role making and performance of self, and microlevel influences on institutional change. The dissertation also encourages a new direction for sociological research – human interactions with the divine. / Thesis / Doctor of Philosophy (PhD) / This thesis investigates what it is like to be a female pastor in the Christian church in Canada, as women have only recently been able to be fully ordained in most Protestant denominations. Three themes are explored: (1) how women decide to enter into Christian ministry, (2) how they navigate dilemmas around clothing in the pastoral role, and (3) how they feel they do pastoral ministry differently than their male counterparts. On a more theoretical level, this thesis also helps us understand the experiences of women entering traditionally male occupations, illuminating how they – and perhaps anyone who undergoes a career transition – navigate changes in work roles and identities, how clothing can help them achieve legitimacy in a role, and how women may be changing the professions they enter into in large numbers by doing their work differently.

I denna mastersuppsats undersöker författaren det möjliga värdet av karriärteorier. Värdet är empiriskt undersökt med utgångspunkt I tio fallstudier av intervjutyp. Författaren kommer till slutsatsen att kunskap om karriärteorier möjliggör en bättre förståelse av hur individer fattar karriär- och utbildningsbeslut. Författaren argumenterar för att kunskap om karriärteorier är, och bör vara relevant för vägledarnas profession och yrkesroll. / In this master thesis the author investigates the potential value of career theories. The potential value is empirically investigated on the basis of ten interviewee case studies. The author reaches the conclusion that career theories does enable a better understanding of how individuals make career- and educational choices and argues that knowledge of career theories is, and should be relevant for the guidance counsellors professional role.

Malgré l’intérêt grandissant des études portant sur le processus de désistement du crime, cet aspect demeure l’un des moins bien compris de la carrière criminelle. À ce jour, peu de recherches se sont penchées sur le lien entre la carrière criminelle passée et la période qui lui succède, soit le désistement. Cette présente étude vise à reconstruire les trajectoires criminelles d’individus ayant poursuivi une carrière criminelle. Les données colligées proviennent des récits narratifs de 15 participants ayant connu une carrière criminelle significative et s’identifiant comme s’étant désistés avec succès. L’objectif derrière ce projet est de mieux saisir le processus de maintien à long terme du désistement criminel. Une attention particulière est accordée à l’influence de la trajectoire criminelle (ses circonstances, ses paramètres) et sur la façon dont se déploie le processus de désistement. L’échantillon de délinquants examinés dans cette recherche se démarque par le fait que les individus rencontrés étaient essentiellement impliqués dans une criminalité à but lucratif. L’objectif spécifique des analyses qualitatives réalisées était d’observer s’il y avait un lien entre le niveau de réussite (revenu criminel et évitement des sanctions pénales) et le sens ou la représentation du désistement criminel. La première contribution est de montrer, comme d’autre avant nous, que le désistement est un processus et non un moment précis dans la carrière criminelle. La seconde contribution est d’avoir montré l’incidence de la réussite criminelle sur les autres paramètres de la trajectoire criminelle. La troisième contribution est d’avoir identifié deux types d’influences de la réussite criminelle (les deux côtés de la médaille) ; d’un côté elle prolonge la carrière criminelle et de l’autre, une fois ladite carrière terminée, la réussite peut faciliter la réinsertion sociale. À la lumière des résultats, la réussite criminelle se doit d’être considérée comme un paramètre « officiel » de la carrière criminelle. Finalement, une telle recherche permet d’orienter le développement de programmes visant la réinsertion sociale. / Despite the increasing interest of researchers towards criminal desistance, this aspect remains one of the less understood of the criminal career. To this day, only few researches have attempted to analyze the link between an individual’s past criminal career and the period that follows it, which would be known as the desistance period. This present study attempts to reconstruct the criminal trajectory of individuals who have pursued criminal careers. The collected data come from 15 participant’s self-narrative stories who have led significant criminal careers and who now identify themselves as having successfully desisted. The objective behind this project is to better understand the long-term maintenance process of the criminal desistance. Particular attention will be given to the influence of the criminal trajectory (the circumstances, the parameters) and how the desistance process takes place. The sample of examined criminals in this research stands out by the fact that the surveyed individuals were essentially involved in lucrative crimes. The specific objective of the qualitative analyses was to observe if there was a link between the success level (criminal revenues and avoidance of criminal sanctions) and the meaning or the representation of criminal desistance. The first contribution is to demonstrate, as others before us, that desistance is a process and not a precise moment in the criminal career. The second contribution is the demonstration of the incidence of criminal success on the other parameters of the criminal trajectory. The third contribution is the demonstration that two types of influence were associated with criminal success (the two sides of the medal); on one side, it lengthens the criminal career, and on the other, it can facilitate the social rehabilitation once the individual quits his criminal career. The results suggest that criminal success has to be considered as an “official” parameter of the criminal career. Finally, this type of research helps orientate the development of programs aimed toward social rehabilitation.

Die Länge der Vegetationsperiode (VP) spielt eine zentrale Rolle für die interannuelle Variation der Kohlenstoffspeicherung terrestrischer Ökosysteme. Die Analyse von Beobachtungsdaten hat gezeigt, dass sich die VP in den letzten Jahrzehnten in den nördlichen Breiten verlängert hat. Dieses Phänomen wurde oft im Zusammenhang mit der globalen Erwärmung diskutiert, da die Phänologie von der Temperatur beeinflusst wird.<br /> <br /> Die Analyse der Pflanzenphänologie in Süddeutschland im 20. Jahrhundert zeigte:<br /> - Die starke Verfrühung der Frühjahrsphasen in dem Jahrzehnt vor 1999 war kein singuläres Ereignis im 20. Jahrhundert. Schon in früheren Dekaden gab es ähnliche Trends. Es konnten Perioden mit unterschiedlichem Trendverhalten identifiziert werden.<br /> - Es gab deutliche Unterschiede in den Trends von frühen und späten Frühjahrsphasen. Die frühen Frühjahrsphasen haben sich stetig verfrüht, mit deutlicher Verfrühung zwischen 1931 und 1948, moderater Verfrühung zwischen 1948 und 1984 und starker Verfrühung zwischen 1984 und 1999. Die späten Frühjahrsphasen hingegen, wechselten ihr Trendverhalten in diesen Perioden von einer Verfrühung zu einer deutlichen Verspätung wieder zu einer starken Verfrühung.<br /> <br /> Dieser Unterschied in der Trendentwicklung zwischen frühen und späten Frühjahrsphasen konnte auch für ganz Deutschland in den Perioden 1951 bis 1984 und 1984 bis 1999 beobachtet werden.<br /> Der bestimmende Einfluss der Temperatur auf die Frühjahrsphasen und ihr modifizierender Einfluss auf die Herbstphasen konnte bestätigt werden. Es zeigt sich jedoch, dass <br /> - die Phänologie bestimmende Funktionen der Temperatur nicht mit einem globalen jährlichen CO2 Signal korreliert waren, welches als Index für die globale Erwärmung verwendet wurde<br /> - ein Index für grossräumige regionale Zirkulationsmuster (NAO-Index) nur zu einem kleinen Teil die beobachtete phänologischen Variabilität erklären konnte.<br /> <br /> Das beobachtete unterschiedliche Trendverhalten zwischen frühen und späten Frühjahrsphasen konnte auf die unterschiedliche Entwicklung von März- und Apriltemperaturen zurückgeführt werden. Während sich die Märztemperaturen im Laufe des 20. Jahrhunderts mit einer zunehmenden Variabilität in den letzten 50 Jahren stetig erhöht haben, haben sich die Apriltemperaturen zwischen dem Ende der 1940er und Mitte der 1980er merklich abgekühlt und dann wieder deutlich erwärmt.<br /> Es wurde geschlussfolgert, dass die Verfrühungen in der Frühjahrsphänologie in den letzten Dekaden Teile multi-dekadischer Fluktuationen sind, welche sich nach Spezies und relevanter saisonaler Temperatur unterscheiden. Aufgrund dieser Fluktuationen konnte kein Zusammenhang mit einem globalen Erwärmungsignal gefunden werden.<br /> Im Durchschnitt haben sich alle betrachteten Frühjahrsphasen zwischen 1951 und 1999 in Naturräumen in Deutschland zwischen 5 und 20 Tagen verfrüht. Ein starker Unterschied in der Verfrühung zwischen frühen und späten Frühjahrsphasen liegt an deren erwähntem unterschiedlichen Verhalten. Die Blattverfärbung hat sich zwischen 1951 und 1999 für alle Spezies verspätet, aber nach 1984 im Durchschnitt verfrüht. Die VP hat sich in Deutschland zwischen 1951 und 1999 um ca. 10 Tage verlängert.<br /> Es ist hauptsächlich die Änderung in den Frühjahrphasen, die zu einer Änderung in der potentiell absorbierten Strahlung (PAS) führt. Darüber hinaus sind es die späten Frühjahrsphasen, die pro Tag Verfrühung stärker profitieren, da die zusätzlichen Tage länger undwärmer sind als dies für die frühen Phasen der Fall ist. Um die relative Änderung in PAS im Vergleich der Spezies abzuschätzen, müssen allerdings auch die Veränderungen in den Herbstphasen berücksichtigt werden.<br /> Der deutliche Unterschied zwischen frühen und späten Frühjahrsphasen konnte durch die Anwendung einer neuen Methode zur Konstruktion von Zeitreihen herausgearbeitet werden. Der neue methodische Ansatz erlaubte die Ableitung verlässlicher 100-jähriger Zeitreihen und die Konstruktion von lokalen kombinierten Zeitreihen, welche die Datenverfügbarkeit für die Modellentwicklung erhöhten.<br /> Ausser analysierten Protokollierungsfehlern wurden mikroklimatische, genetische und Beobachtereinflüsse als Quellen von Unsicherheit in phänologischen Daten identifiziert. Phänologischen Beobachtungen eines Ortes können schätzungsweise 24 Tage um das parametrische Mittel schwanken.Dies unterstützt die 30-Tage Regel für die Detektion von Ausreissern.<br /> Neue Phänologiemodelle, die den Blattaustrieb aus täglichen Temperaturreihen simulieren, wurden entwickelt. Diese Modelle basieren auf einfachen Interaktionen zwischen aktivierenden und hemmenden Substanzen, welche die Entwicklungsstadien einer Pflanze bestimmen. Im Allgemeinen konnten die neuen Modelle die Beobachtungsdaten besser simulieren als die klassischen Modelle.<br /> <br /> Weitere Hauptresultate waren:<br /> - Der Bias der klassischen Modelle, d.h. Überschätzung von frühen und Unterschätzung von späten Beobachtungen, konnte reduziert, aber nicht vollständig eliminiert werden.<br /> - Die besten Modellvarianten für verschiedene Spezies wiesen darauf hin, dass für die späten Frühjahrsphasen die Tageslänge eine wichtigere Rolle spielt als für die frühen Phasen.<br /> - Die Vernalisation spielte gegenüber den Temperaturen kurz vor dem Blattaustrieb nur eine untergeordnete Rolle. / The length of the vegetation period (VP) plays a central role for the interannual variation of carbon fixation of terrestrial ecosystems. Observational data analysis has indicated that the length of the VP has increased in the last decades in the northern latitudes mainly due to an advancement of bud burst (BB). This phenomenon has been widely discussed in the context of Global Warming because phenology is correlated to temperatures. <br /> <br /> Analyzing the patterns of spring phenology over the last century in Southern Germany provided two main findings:<br /> - The strong advancement of spring phases especially in the decade before 1999 is not a singular event in the course of the 20th century. Similar trends were also observed in earlier decades. Distinct periods of varying trend behavior for important spring phases could be distinguished.<br /> - Marked differences in trend behavior between the early and late spring phases were detected. Early spring phases changed as regards the magnitude of their negative trends from strong negative trends between 1931 and 1948 to moderate negative trends between 1948 and 1984 and back to strong negative trends between 1984 and 1999. Late spring phases showed a different behavior. Negative trends between 1931 and 1948 are followed by marked positive trends between 1948 and 1984 and then strong negative trends between 1984 and 1999.<br /> This marked difference in trend development between early and late spring phases was also found all over Germany for the two periods 1951 to 1984 and 1984 to 1999.<br /> <br /> The dominating influence of temperature on spring phenology and its modifying effect on autumn phenology was confirmed in this thesis. However,<br /> - temperature functions determining spring phenology were not significantly correlated with a global annual CO2 signal which was taken as a proxy for a Global Warming pattern.<br /> - an index for large scale regional circulation patterns (NAO index) could only to a small part explain the observed phenological variability in spring.<br /> <br /> The observed different trend behavior of early and late spring phases is explained by the differing behavior of mean March and April temperatures. Mean March temperatures have increased on average over the 20th century accompanied by an increasing variation in the last 50 years. April temperatures, however, decreased between the end of the 1940s and the mid-1980s, followed by a marked warming after the mid-1980s. <br /> It can be concluded that the advancement of spring phenology in recent decades are part of multi-decadal fluctuations over the 20th century that vary with the species and the relevant seasonal temperatures. Because of these fluctuations a correlation with an observed Global Warming signal could not be found.<br /> On average all investigated spring phases advanced between 5 and 20 days between 1951 and 1999 for all Natural Regions in Germany. A marked difference be! tween late and early spring phases is due to the above mentioned differing behavior before and after the mid-1980s. Leaf coloring (LC) was delayed between 1951 and 1984 for all tree species. However, after 1984 LC was advanced. Length of the VP increased between 1951 and 1999 for all considered tree species by an average of ten days throughout Germany.<br /> It is predominately the change in spring phases which contributes to a change in the potentially absorbed radiation. Additionally, it is the late spring species that are relatively more favored by an advanced BB because they can additionally exploit longer days and higher temperatures per day advancement. To assess the relative change in potentially absorbed radiation among species, changes in both spring and autumn phenology have to be considered as well as where these changes are located in the year.<br /> For the detection of the marked difference between early and late spring phenology a new time series construction method was developed. This method allowed the derivation of reliable time series that spanned over 100 years and the construction of locally combined time series increasing the available data for model development.<br /> Apart from analyzed protocolling errors, microclimatic site influences, genetic variation and the observers were identified as sources of uncertainty of phenological observational data. It was concluded that 99% of all phenological observations at a certain site will vary within approximately 24 days around the parametric mean. This supports to the proposed 30-day rule to detect outliers. <br /> New phenology models that predict local BB from daily temperature time series were developed. These models were based on simple interactions between inhibitory and promotory agents that are assumed to control the developmental status of a plant. Apart from the fact that, in general, the new models fitted and predicted the observations better than classical models, the main modeling results were: <br /> - The bias of the classical models, i.e. overestimation of early observations and underestimation of late observations, could be reduced but not completely removed. <br /> - The different favored model structures for each species indicated that for the late spring phases photoperiod played a more dominant role than for early spring phases. <br /> - Chilling only plays a subordinate role for spring BB compared to temperatures directly preceding BB.

This thesis concerns the differences in how ethinic groups co-exist in two different environments in the same country, with a focus on the ethno-political. My research questions are: Why are ethnic or interpersonal relations characterized differently in different regions? How and why do conflicts or agreements arise in specific environments? The aim is to understand the connection between inter-ethnic relations and environmentally specific factors. I am concerned with those mechanisms and processes which determine the type of ethnic relation – as conflict or mutual understanding - in specific environments. The thesis uses case studies of two contrasting multiethnic cities with different interethnic relations – Erbil and Kirkuk in Kurdistan/Iraq. My explanatory model consists of four main factors: I) historical factors in terms of critical events; II) institutional factors such as institutional efficiency and security; III) structural factors such as group size, territorial base and different tolerance systems; and IV) social relational factors such as the significance of inter-ethnic contacts and social capital. The empirical work demonstrates that the relations between the above mentioned factors in the respective environments determine the outcome of the inter-ethnic relations. The results show that one factor can be more important than another factor, but how the factors impact upon one another and under what circumstances is of significance. The presentation of environmentally specific differences shows that ethnic groups do not have static boundaries and are not necessarily hostile to one another. Conflict is not the given form of relationship between ethnic groups. That is, the result can be read as a critique of those who necessarily see potential conflicts between groups with cultural differences and those who essentialize cultural groups. In this context one can see a chain of interrelated factors; the relevance of which is dependent on the specific situation. Some of the negative factors that can increase the possibility of conflict and decrease the possibility for peaceful co-existence include: Instability in the political climate; insecurity; institutional ineffectiveness; segregation; undefined relations of power; and an ethnic composition maintaining the balance of power. If these factors combined result in a high level of complexity, which makes ethnicity stand out in terms of ethnic competition, the likelihood of ethnic conflict is significant.

The purpose of the study is to describe and research students roate into the programme, and what it means to students to follow a special secondary school course. The students attended a small specail needs teaching group based on the neuropsychiatric diagnosis of Asperger´s syndrome, which had been made during their years at school. In this connetction, the study will also clarify and analyse the interface between the organisation of a secondary school and the special needs students, from the players´persepctive where the student´attendance at school forms the basis of their education. The students already had a negative image of themselves as pupils before starting their secondary scool education and the learning environment in which they participated in secondary school. Attandance becomes another turning point in the students´statements about their time at school. The experience of being at school has changed. From their perspective- "an inner perspective"- both the courses they had taking, and the school environment, is emphasised as something positive. The fact that affiliation to the programme is positive is an ongoing feature in students´statements. Identification with friends of similar age, who have comparable experinces, above all in relation to school, is emphasised by most students as something positive. Studnets´feeling of communityis based on the knowledge that the reason why they are on programme is because they have had different problems in relation to school. For students, the environment is a type of identity- creating forum, where students with the same problems can undertake their education. The diagnosis plays a central part in how students perceive themselves in relation to school and the obstacles they face.

Dans cette thèse, nous nous sommes intéressés à l'analyse locale de systèmes différentiels linéaires singulièrement perturbés et de systèmes de Pfaff complètement intégrables et multivariés à croisements normaux. De tels systèmes ont une vaste littérature et se retrouvent dans de nombreuses applications. Cependant, leur résolution symbolique est toujours à l'étude. Nos approches reposent sur l'état de l'art de la réduction formelle des systèmes linéaires singuliers d'équations différentielles ordinaires univariées (ODS). Dans le cas des systèmes différentiels linéaires singulièrement perturbés, les complications surviennent essentiellement à cause du phénomène des points tournants. Nous généralisons les notions et les algorithmes introduits pour le traitement des ODS afin de construire des solutions formelles. Les algorithmes sous-jacents sont également autonomes (par exemple la réduction de rang, la classification de la singularité, le calcul de l'indice de restriction). Dans le cas des systèmes de Pfaff, les complications proviennent de l'interdépendance des multiples sous-systèmes et de leur nature multivariée. Néanmoins, nous montrons que les invariants formels de ces systèmes peuvent être récupérés à partir d'un ODS associé, ce qui limite donc le calcul à des corps univariés. De plus, nous donnons un algorithme de réduction de rang et nous discutons des obstacles rencontrés. Outre ces deux systèmes, nous parlons des singularités apparentes des systèmes différentiels univariés dont les coefficients sont des fonctions rationnelles et du problème des valeurs propres perturbées. Les techniques développées au sein de cette thèse facilitent les généralisations d'autres algorithmes disponibles pour les systèmes différentiels univariés aux cas des systèmes bivariés ou multivariés, et aussi aux systèmes d''equations fonctionnelles. / In this thesis, we are interested in the local analysis of singularly-perturbed linear differential systems and completely integrable Pfaffian systems in several variables. Such systems have a vast literature and arise profoundly in applications. However, their symbolic resolution is still open to investigation. Our approaches rely on the state of art of formal reduction of singular linear systems of ordinary differential equations (ODS) over univariate fields. In the case of singularly-perturbed linear differential systems, the complications arise mainly from the phenomenon of turning points. We extend notions introduced for the treatment of ODS to such systems and generalize corresponding algorithms to construct formal solutions in a neighborhood of a singularity. The underlying components of the formal reduction proposed are stand-alone algorithms as well and serve different purposes (e.g. rank reduction, classification of singularities, computing restraining index). In the case of Pfaffian systems, the complications arise from the interdependence of the multiple components which constitute the former and the multivariate nature of the field within which reduction occurs. However, we show that the formal invariants of such systems can be retrieved from an associated ODS, which limits computations to univariate fields. Furthermore, we complement our work with a rank reduction algorithm and discuss the obstacles encountered. The techniques developed herein paves the way for further generalizations of algorithms available for univariate differential systems to bivariate and multivariate ones, for different types of systems of functional equations.