• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 59
  • 59
  • 35
  • 24
  • 20
  • 13
  • 11
  • 8
  • 7
  • 5
  • 3
  • 3
  • 3
  • 3
  • 3
  • Tagged with
  • 257
  • 27
  • 24
  • 20
  • 20
  • 19
  • 18
  • 16
  • 16
  • 15
  • 15
  • 14
  • 13
  • 13
  • 12
  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
21

Vägen mot en jämställd svensk golf : - En dröm eller verklighet? / The road to equal Swedish golf : A dream or reality?

Andersson, Alvin, Pedersen, Fabian January 2024 (has links)
The study aims to create an understanding of golf clubs' gender equality work, thechoice of gender equality efforts and to see how this change can become financiallysustainable. Historically, both society and sport have consisted of structures and normsthat have subordinated women. As society has begun to question these structures, golfhas taken a clearer stance on gender equality by providing an education program toclubs. Traditional norms still influence golf today, as there is a perception that golf is asport for rich and older men, which discourages women from participating. The studysample consists of seven golf clubs selected by Annica Lundström from the SwedishGolf Association (SGF) due to her strong relationships and knowledge of the researchtopic. These golf clubs have all done the Vision 50/50 club development program andhave also been certified. The collection of data was carried out through semi-structuredinterviews with various representatives from each club, the material was supplementedby reviewing the clubs' annual reports, membership statistics and their websites. Thedata were then analyzed using a theoretical framework consisting of institutional theoryto understand internal and external pressures. Feminist theory was also used to explaingendered structures and norms within organizations. In addition, resource dependencytheory was applied to understand the resource challenges facing the golf clubs.Theresults indicate that many golf clubs have implemented measures to better integratewomen. This has been done by addressing the club's course, cultural attitudes andrepresentation. The number of female board representatives has increased. However thenumber of female members has decreased in most clubs, in some cases significantly. / Studien syftar till att skapa förståelse för golfklubbars jämställdhetsarbete, valet avjämställdhetsinsatser samt att se hur detta förändringsarbete kan bli ekonomiskt hållbart.Historiskt sett har samhället och idrotten bestått av strukturer och normer som harunderordnat kvinnor. I takt med att samhället börjat ifrågasätta dessa strukturer hargolfen tagit en allt tydligare ställning till jämställdhet genom att tillhandahålla ettutbildningsprogram till klubbar. Traditionella normer präglar golfen än idag då det finnsen uppfattning om att golf är en rikemanssport, gubbsport och detta kan hejda kvinnorfrån golf. Studiens urval består av 7 golfklubbar som valts ut av Annica Lundström påSGF eftersom hon har en god relation och kunskapsbas om forskningsämnet. Dessagolfklubbar har alla genomgått klubbutvecklingsprogrammet vision 50/50 och dessutomblivit diplomerade. Insamlingen av datan genomfördes genom semistruktureradeintervjuer med olika representanter från varje klubb, materialet kompletterades genomatt granska klubbarnas årsrapporter, medlemsstatistik och information via deraswebbsidor. Datan har sedan analyserats av det teoretiska ramverket bestående avinstitutionell teori för att förstå interna och externa påtryckningar. En annan teori varfeministisk teori för att förklara könsbaserade strukturer och normer inomorganisationer. Utöver detta har tillämpningen av resursberoende förekommit för attförstå golfklubbarnas resursutmaningar. Resultatet tyder på att många golfklubbar hartillhandahållit insatser för att integrera kvinnor. Detta har gjorts genom attuppmärksamma klubbens bana, kulturella attityder och representation. Antalet kvinnligastyrelserepresentanter har ökat och antalet kvinnliga medlemmar sjunkit. Majoriteten avgolfklubbar har minskat antalet kvinnliga medlemmar, vissa har dessutom gjort detmarkant.
22

Kan NOSACQ-50 mäta säkerhetsklimat inom grundskoleverksamhet? : en explorativ studie med Nordic Safety Climate Questionnaire NOSACQ-50 som verktyg / Is it possible to meassure safetyclimate within primary activity with NOSACQ-50? : an explorative study with Nordic Safety Climate Questionnaire as a instrument

Strömberg, Fanny, Lind, Felicia January 2016 (has links)
Grundskolan i Sverige är den största organisationen i landet och risker för attentat och andra förödande händelser kan förekomma. Skolattacken i Trollhättan som under hösten 2015 inträffade är ett exempel på ett sådant attentat som skett inom svensk skolverksamhet. Vid närmare granskning upptäcktes det att det finns mycket få publicerade studier kring säkerhetsklimat inom skolverksamhet, vilket väckte ett intresse att undersöka detta närmare. Syftet med föreliggande studie var att med kvantitativ ansats undersöka om Nordic Safety Climate Questionnaire kan mäta säkerhetsklimat inom grundskoleverksamhet. Mätinstrumentet NOSACQ-50 består av 50 påståenden som är indelade i 7 säkerhetsklimatdimensioner och 2 undersökningsområden. Då skolor präglas av barn och ungdomar har personalen ett stort ansvar för deras säkerhet och därför var det de som blev föreliggande studies undersökningsdeltagare. I föreliggande studie gjordes ett bekvämlighetsurval och studien avgränsades till grundskoleverksamhet då det där fanns kontakter och goda möjligheter för att underlätta datainsamlingen. Urvalet bestod av 60 undersökningsdeltagare från 3 grundskolor i södra Sverige. Undersökningsdeltagarna var mellan åldrarna 22 år till 68 år där 17 var män, 43 var kvinnor och där 5 stycken har en arbetsledande befattning. Studiens resultat visade att NOSACQ-50 kan mäta säkerhetsklimat inom grundskoleverksamhet. NOSACQ-50 uppvisade en hög tillförlitlighet men två dimensioner (4 och 5) uppvisade ett lägre alfavärde. Det kan bero på att frågorna i dessa dimensioner kan vara mindre lämpade för att mäta säkerhetsklimat inom grundskoleverksamhet. NOSACQ-50 kunde inte urskilja säkerhetsklimatnivåer mellan grundskolorna. / The elementary school in Sweden is the largest organization in the country and the risks of attacks and other devastating events can occur. The school attack in Trollhattan in the autumn of 2015 is an example of such an attack that occurred in the Swedish school activity. During closer examination it was discovered that there are very few published studies about the safety climate in school activities, which created an interest to investigate this further. The aim of the present study was to investigate the quantitative approach of the Nordic Safety Climate Questionnaire, which is an instrument that can measure the security climate in primary activities. The measuring instrument NOSACQ-50 consists of 50 claims that are divided into 7 security climate dimensions and 2 study areas. When children and young people characterize schools, the staff has a great responsibility for their security and therefore it was those who were present studies survey participants. In the present study a convenience sample was made and the study was restricted to primary business since there were available contacts and therefore a good opportunity to facilitate data collection. The sample consisted of 60 study participants from 3 primary schools in southern Sweden. Study participants were between the ages of 22 years old to 68 years old, where 17 were men, 43 were women and where 5 have a managerial position. The study results showed that NOSACQ-50 could measure the security climate in primary activities. NOSACQ-50 showed a high reliability but 2 dimensions (4 and 5) exhibited a lower alpha value. It may be due to issues in these dimensions may be less suited for measuring safety climate in primary activities. NOSACQ-50 could not distinguish the security climate levels from primary schools.
23

Histórias em quadrinhos sobre a História do Brasil na década de 50: A narrativa dos artistas da Ebal e outras editoras / Histórias em quadrinhos sobre a História do Brasil na década de 50: A narrativa dos artistas da Ebal e outras editoras

Barbosa, Alexandre Valença Alves 17 April 2006 (has links)
Este trabalho procura fazer levantamentos sobre histórias em quadrinhos que narram fatos históricos, com ênfase nas histórias produzidas no Brasil na década de 50, principalmente aqueles produzidas pela editora EBAL. Uma analogia com outros países que produziram quadrinhos similares no mesmo período é apresentada no intuito de comparar as narrativas em cada um deles e no Brasil. As narrativas são analisadas de forma separada, ou seja, o texto e as imagens que compõem a história em quadrinhos são primeiramente classificados e depois um paralelo é traçado para que se possa verificar a forma como artistas e roteiristas trabalhavam este gênero. O estudo mostra como os artistas trabalhavam a informação histórica e como faziam sua adaptação para histórias em quadrinhos. Mostra também como esta narrativa de fatos históricos produzida no Brasil, na década de 50, foi influenciada e no que influenciou posteriormente. / This work try makes a survey in comics what tell about historical facts, with emphasis in histories produced in Brazil in the decade of 50, mainly those produced by the EBAL publishing company. An analogy with other countries that had produced similar comics in the same period in intention to compare the narratives in each one of them and Brazil. Narratives are analyzed in separate form, or either, the text and the images that compose the comics are classified in first and after a parallel are traced to verify the form as artists and scriptwriters worked this sort. The study it shows as the artists worked the historical information and how they did adaptation for comics. Sample also as this narrative of historical facts produced in Brazil, in the decade of 50, was influenced and in that influenced later.
24

Samband och könsskillnader mellan kriminalvårdares personlighetsdrag och upplevelse av säkerhetsklimat / Relationships and gender differences between the personality traits of prison officers and their experiences of safety climate

Severinsson, Louise, Åkesson, Maria January 2011 (has links)
Anstalten Hall utanför Södertälje tillhör säkerhetsklass A, vilket innebär att de intagna utgör en hög risk för allmänheten. De anställda har därmed ett stort ansvar i att upprätthålla säkerheten på anstalten. Syftet med föreliggande studie var att undersöka möjliga samband mellan kriminalvårdarnas personlighet, deras upplevelse av säkerhetsklimatet och upplevda incidenter. Vidare studerades könsskillnader avseende personlighetsdrag och upplevelse av säkerhetsklimat. För att undersöka detta användes säkerhetsformuläret NOSACQ-50 och personlighetsskalan Swedish universities Scales of Personality (SSP). Totalt ingick 30 deltagare i studien. Signifikanta samband fanns mellan personlighetsdragen misstroende, bitterhet, somatisk ångestbenägenhet, social konformitet och verbal aggressionsförmåga i förhållande till hur de anställda upplevde säkerhetssystemet samt ledningen och kollegornas säkerhetsarbete.  Signifikanta skillnader i personlighetsdragen fanns endast mellan mäns och kvinnors somatiska ångestbenägenhet, där kvinnor hade utmärkande högre värden. I övrigt visades inga signifikanta skillnader mellan personlighetsdragen. Vad det gällde upplevelser av säkerhetsklimatet på anstalten mellan könen kunde vissa skillnader utläsas, men dessa var inte signifikanta. Resultaten antyder att människor som arbetar inom kriminalvården är ganska lika varandra och att personlighetsdrag till viss del kan inverka på upplevelsen av arbetsplatsens säkerhetsklimat. Då antalet deltagare är begränsat bör dock slutsatser dras med försiktighet. / The prison Hall near Södertälje has safety class A. This means that prisoners constitute a high risk to the public and the employees have a great respons­ibility in maintaining security at the prison. The purpose of this study was to explore possible relationships and differences between the prison officers’ views on safety climate and their personal traits. Furthermore gender differences in personality traits and experience of safety climate were studied. The security form NOSACQ-50 and Swedish universities Scales of Personality (SSP) were used. A total of 30 participants were included in the analysis. Significant correlations were found between the personality traits mistrust, embitterment, somatic trait anxiety, social desirability and verbal trait aggression in relation to how the employees experienced the safety climate. Significant differences in personality traits were found between male and female only in somatic trait anxiety, where women had distinctively higher values then men. When it came to perceptions of safety climate between the sexes some differences could be seen, but these were not significant. The results suggest that men and women working in prisons are quite similar and that personality traits may to some extent affect the experience of the workplace safety climate. As the number of participants is limited, however, care should be taken when making conclusions.
25

Histórias em quadrinhos sobre a História do Brasil na década de 50: A narrativa dos artistas da Ebal e outras editoras / Histórias em quadrinhos sobre a História do Brasil na década de 50: A narrativa dos artistas da Ebal e outras editoras

Alexandre Valença Alves Barbosa 17 April 2006 (has links)
Este trabalho procura fazer levantamentos sobre histórias em quadrinhos que narram fatos históricos, com ênfase nas histórias produzidas no Brasil na década de 50, principalmente aqueles produzidas pela editora EBAL. Uma analogia com outros países que produziram quadrinhos similares no mesmo período é apresentada no intuito de comparar as narrativas em cada um deles e no Brasil. As narrativas são analisadas de forma separada, ou seja, o texto e as imagens que compõem a história em quadrinhos são primeiramente classificados e depois um paralelo é traçado para que se possa verificar a forma como artistas e roteiristas trabalhavam este gênero. O estudo mostra como os artistas trabalhavam a informação histórica e como faziam sua adaptação para histórias em quadrinhos. Mostra também como esta narrativa de fatos históricos produzida no Brasil, na década de 50, foi influenciada e no que influenciou posteriormente. / This work try makes a survey in comics what tell about historical facts, with emphasis in histories produced in Brazil in the decade of 50, mainly those produced by the EBAL publishing company. An analogy with other countries that had produced similar comics in the same period in intention to compare the narratives in each one of them and Brazil. Narratives are analyzed in separate form, or either, the text and the images that compose the comics are classified in first and after a parallel are traced to verify the form as artists and scriptwriters worked this sort. The study it shows as the artists worked the historical information and how they did adaptation for comics. Sample also as this narrative of historical facts produced in Brazil, in the decade of 50, was influenced and in that influenced later.
26

Toward Reproducible Domain-Wall Conductance in Lithium Niobate Single Crystals

Kiseleva, Iuliia 24 October 2023 (has links)
Conductive domain walls (DWs) in lithium niobate (LiNbO3, LNO) are promising constituents for potential applications in nanoelectronics, due to their high conductance, as compared to the surrounding bulk material, their high local confinement at the nanometer scale, and the ability to be created quasi-on-will through dedicated high-voltage poling. However, electrically contacting the DWs unavoidably leads to the formation of a potential barrier between the DW itself and the electrode material. Thus, the focus of this work is the investigation of the various factors influencing the electronic transport across that barrier, namely, the type of electrode material, the quality of the LNO surface (atomically-smooth versus mirror polished), the quality of the crystal lattice (i.e., the presence of higher concentrations of lithium and oxygen vacancies VLi and VO), and the magnitude of the applied voltages during the domain-wall conductivity (DWC) enhancement procedure. It is found that all the above-mentioned factors have a significant impact on the current-voltage characteristics of the DW-electrode system. For example, the metal electrodes deposited onto the surface of the LNO crystal, once, impede the DW motion, while, secondly, stabilizing the DWs inclination across the LNO crystal. Another important finding is the major role played by large negative voltages in the DWC-enhancement procedure that strongly influences the near-surface structure of the DW, and hence the qualitative characteristics of the formed potential barrier, such as characteristic voltage and saturation current. The application of moderate voltages from –50 V to –100 V is also found to influence the structure of the near-surface DW. The creation of a variety of vacancy defects inside the bulk LNO that accompanies the formation of an atomically-smooth surface, is found to have far more influence on the DW charge transport than the quality of the surface, due to the formation and repulsive interaction of a multitude of spike domains stemming from these defects. In summary, the results demonstrate the importance of providing known and reproducible sample surface conditions and identifying promising directions for implementing reproducible domain wall conductivity.
27

Covenant, Typology, and the Story of Joseph: A Literary-Canonical Examination of Genesis 37-50

Emadi, Samuel Cyrus 23 December 2016 (has links)
This dissertation defends the notion that Joseph, understood according to a literary-canonical analysis, functions as the resolution to the plot of Genesis and that this story typologically influences how later biblical authors narrate redemptive history culminating in the NT’s portrayal of Jesus as an antitypical Joseph. My research explores two questions: First, what is the literary and biblical-theological significance of the Joseph narrative as the conclusion to Genesis? Second, how do later biblical authors interpret and reuse the Joseph narrative? Chapter 1 explains the rationale for this project and introduces readers to the supposed “problem” of Joseph’s prominence in Genesis and relative absence in the rest of the canon. In this chapter, I survey the dominant approaches to the Joseph story with regard to his role in Genesis in particular and, more generally, in the canon. Most historical-critical scholars posit that Joseph’s story is largely disconnected from the rest of the Genesis narrative. This chapter also surveys the history of the interpretation of the Joseph narrative. I note that almost all pre-modern interpreters saw Joseph primarily as a typological character—a tradition which continues among many evangelical interpreters of Scripture. Chapter 2 explains the methodology of this dissertation. In this chapter, I defend my understanding of biblical-theology and my approach to typology as one regulated by the interpretive practices of the New Testament authors. I argue that types are historical, prospective, textual, covenantal, and that they exhibit escalation in moving from type to antitype Chapter 3 examines the story of Joseph within the context of Genesis. I explore Joseph’s place with the toledot structure of Genesis, his relationship to the Abrahamic covenant, and his role in the storyline of Genesis. By considering Joseph’s relationship to the land, seed, blessing, and kingship promises of the Abrahamic covenant, I conclude that Joseph is an anticipatory fulfilment of the covenant promises. Furthermore, I demonstrate how Joseph reverses fraternal conflict and famine—two major themes in Genesis. In light of these and other evidences, I argue that, even within the context of Genesis itself, Joseph is a typological figure. Chapter 4 investigates the explicit mentions of Joseph in the OT in order to discern how later biblical authors interpreted the Joseph story. I argue that Psalm 105 interprets Joseph within the framework of the Abrahamic promises. The psalmist sees Joseph as God’s instrument for fulfilling those promises in a provisional, anticipatory way. This chapter also explores allusions to the Joseph narrative in Daniel and considers Joseph’s contribution to the canonical motif of the exalted Jew in a foreign court. I conclude that the OT authors interpreted Joseph’s life as a harbinger of the exodus and as an archetypal figure whose life anticipated later events in Israel’s history. Finally, chapter 5 investigates two explicit references to Joseph in the NT: Acts 7 and Hebrews 11. In Hebrews 11, Joseph is presented as a moral exemplar on account of his faith in God’s promises. My analysis of Acts 7 shows that Stephen interpreted Joseph’s story as a microcosm of Israel’s history. Joseph and Moses exemplify Israel’s rejection of their deliverers, a pattern which culminates in their rejection of Jesus. Jesus makes the same point in the parable of the tenants. Israel’s constant rebellion against God’s messengers typifies their ultimate rejection of the “beloved son”—an event anticipated by the patriarchs’ rejection of Joseph. These passages, then, explicitly confirm what appears suggested throughout the OT—namely, Joseph is a type of the Messiah.
28

Las imágenes heroicas en la trilogía narrativa de Luis Loayza: El avaro (1955), Una piel de serpiente (1964) y Otras tardes (1985)

Chávez Caro, Helen Dianne January 2015 (has links)
Las imágenes heroicas de Loayza han sufrido diversas modificaciones desde sus primeros relatos hasta llegar a consolidarse en Otras tardes, pero siempre han conservado sus rasgos fundamentales. En el siguiente trabajo, nuestra hipótesis es que pese a las diferencias genéricas de sus creaciones, la figura del héroe en el caso de Loayza debe ser vista como una constante cuya función principal se encuentra en llevar a cabo el proceso de desmitificación. En el primer capítulo revisaremos los enfoques a partir de los cuales se ha planteado el origen de las imágenes heroicas desde los mitos de la antigüedad hasta los tiempos actuales. Con ello buscamos presentar un panorama de la evolución de la figura del «héroe» en la literatura. Además haremos la diferenciación entre las categorías de héroe y antihéroe. En el segundo capítulo se incluye una revisión crítica de la obra de Luis Loayza desde los años cincuenta hasta la fecha. Luego se procederá a estudiar los elementos narrativos constantes encontrados en «la trilogía», la cual está conformada por tres de sus obras principales: El avaro, Una piel de serpiente y Otras tardes. Entre los elementos abordados en nuestro trabajo están la soledad, la inacción y la incomunicación. Estas son características propias de las imágenes heroicas de Luis Loayza. Empezaremos el tercer capítulo con un marco metodológico de los conceptos que serán empleados en el análisis de los relatos. Partiremos de la definición de mundos posibles de Lubomír Doležel y continuaremos con la revisión de los conceptos de metaficción estudiados por la investigadora colombiana Clemencia Ardila, puesto que son herramientas que se pueden aplicar a las tres obras a pesar de sus diferencias genéricas. Posteriormente, se realizará el análisis respectivo de cada relato, cuyo objetivo consiste en demostrar la actitud desmitificadora del héroe en la narrativa de Luis Loayza. Para el abordaje del trabajo emplearemos, Relatos tomo donde se reúne la obra narrativa completa del escritor. Este texto fue editado en el año 2010 por la Universidad Ricardo Palma y revisado por Loayza antes de su publicación. A modo de conclusión, señalaremos que el abordaje de los elementos narrativos encontrados en las tres obras es fundamental para determinar la configuración de las imágenes heroicas, ya que de esta forma se establece su rol desmitificador y la figura del «héroe» puede ser vista como una constante narrativa en la obra de Luis Loayza.
29

Mission to the Gentiles in Luke-Acts as fulfilling God's promise to Israel: A critical reading of the Apostolic Decree of the Jerusalem Council in Acts 15:1-29

Min, Guofang January 2018 (has links)
Thesis advisor: Christopher R. Matthews / Thesis advisor: Thomas D. Stegman / The overall narrative in the Acts of the Apostles displays a noticeable dual-emphasis of the author: emphasis on the mission to the Gentiles despite the obstructions of the Jews and emphasis on the Jewish roots of the Gentile mission, which results in an ambivalent attitude toward the Jews and Judaism. These seemingly contradictory emphases easily push careless readers to an unbalanced interpretation and reading of Acts, and the Holocaust is the ultimate horrible consequence of the anti-Semitic interpretation of Acts. This thesis argues that the two emphases, rather than being contradictory, are mutually intertwined: Jewish roots help illuminate the origin and meaning of the mission to the Gentiles, and the mission to the Gentiles fulfills the promise God made to Israel. A good example of this is the Apostolic Letter composed at the Jerusalem Council, which was held to address and solve the problem of the conditions by which the Gentiles could be members of the church (cf. Acts 15:2). In this study, I will place the Apostolic Letter (15:23-29) within a larger theological and narrative framework of Luke-Acts—the fulfillment of God’s promise to Israel— and argue that, as Luke’s rhetorical device, the Decree (15:20, 29; 21:25) not only serves to explain some already existing practices among Jewish and Gentile Christians, but more importantly, serves as a guiding principle for concrete table fellowship between Jewish believers and Gentile believers within a community that calls its believers to be of “one heart and soul” (4:32). / Thesis (STL) — Boston College, 2018. / Submitted to: Boston College. School of Theology and Ministry. / Discipline: Sacred Theology.
30

The role of host dendritic cells during the effector phase of intestinal graft-versus-host disease / Die Rolle der dendritischen Zellen in der akuten intestinalen Graft-versus-Host Reaktion

Jordan Garrote, Ana-Laura January 2014 (has links) (PDF)
Monocytes can be functionally divided in two subsets, both capable to differentiate into dendritic cells (DCs): CX3CR1loCCR2+ classical monocytes, actively recruited to the sites of inflammation and direct precursors of inflammatory DCs; and CX3CR1hiCCR2− non-classical monocytes, characterized by CX3CR1-dependent recruitment to non-inflamed tissues. Yet, the function of non-classical monocyte-derived DCs (nc-mo-DCs), and the factors, which trigger their recruitment and DC differentiation, have not been clearly defined to date. Here we show that in situ differentiated nc-moDCs mediate immunosuppression in the context of intestinal graft-versus-host disease (GVHD). Employing multi-color confocal microscopy we observed a dramatic loss of steady state host-type CD103+ DC subset immediately after transplantation, followed by an enrichment of immune-regulatory CD11b+ nc-moDCs. Parabiosis experiments revealed that tissue-resident non-classical CX3CR1+ monocytes differentiated in situ into intestinal CD11b+ nc-moDCs after allogeneic hematopoietic cell transplantation (allo-HCT). Differentiation of this intestinal DC subset depended on CSF-1 but not on Flt3L, thus defining the precursors as monocytes and not pre-DCs. Importantly, CX3CR1 but not CCR2 was required for this DC subset differentiation, hence defining the precursors as non-classical monocytes. In addition, we identify PD-L1 expression by CX3CR1+ nc-moDCs as the major mechanism they employ to suppress alloreactive T cells during acute intestinal GVHD. All together, we demonstrate that host nc-moDCs surprisingly mediate immunosuppression in the context of murine intestinal GVHD – as opposed to classical “inflammatory” monocyte-derived dendritic cells (mo-DCs) – via coinhibitory signaling. This thorough study unravels for the first time a biological function of a - so far only in vitro and phenotypically described - DC subset. Our identification of this beneficial immunoregulatory DC subset points towards alternate future strategies in underpinning molecular pathways to foster their function. We describe an unexpected mechanism of nc-moDCs in allo-HCT and intestinal GVHD, which might also be important for autoimmune disorders or infections of the gastrointestinal tract. / Monozyten (MO) lassen sich funktionell in zwei Subpopulationen unterteilen, die sich in dendritische Zellen (DC) differenzieren können: 1) Klassische Monozyten (CX3CR1loCCR2+), die direkte Vorläuferzellen von inflammatorischen DCs (mo-DCs) sind und aktiv an die Stelle der Entzündung rekrutiert werden und 2) nicht-klassische Monozyten (CX3CR1hiCCR2−). Bisher ist weder die Funktion der, aus nicht-klassischen Monozyten abstammenden, DC-Subpopulation (nc-mo-DCs) bekannt, noch ist geklärt, welche Faktoren die Ausdifferenzierung und die Rekrutierung der nc-mo-DCs in periphere Gewebe ermöglichen. In dieser Dissertationsarbeit zeige ich, dass nc-mo-DCs in situ differenzieren und in der akuten intestinalen Graft-versus-Host Erkrankung (GVHD) immunsuppressiv wirken. Konfokale Mikroskopie verdeutlichte den Rückgang der, im gesunden Gleichgewicht im intestinalen Gewebe dominierenden, CD103+ DCs direkt nach allogener hämatopoetischer Zelltransplantation (HCT) zugunsten immunregulatorischer CD11b+ nc-moDCs. Weiterhin zeigten Parabiose Experimente, dass nicht-klassische CX3CR1+ Monozyten im intestinalen Gewebe ansässig sind und sich nach allogener HCT in situ zu CD11b+ nc-moDCs ausdifferenzieren. Die Differenzierung findet in Abhängigkeit von CSF-1 und unabhängig von Flt3L statt, ein Beweis dafür, dass dieser Zelltyp aus Monozyten und nicht aus DC-Vorläuferzellen gebildet wird. Die Differenzierung dieser intestinalen DC Subpopulation hängt von CX3CR1, nicht jedoch von CCR2 ab, ein Beweis dafür, dass dieser Zelltyp aus nicht-klassischen Monozyten gebildet wird. Mechanistisch zeigen wir, dass nc-moDCs alloreaktive T-Zellen durch die Expression von PD-L1 supprimieren. Zusammenfassend beschreiben wir erstmalig nc-moDCs als neue DC Subpopluation, die im Mausmodell die intestinale GVHD unterdrückt und sich damit wesentlich von den bisher beschriebenen, klassischen proinflammatorischen mo-DCs unterscheidet. Die von den nc-moDCs vermittelte immunregulatorische Wirkung könnte weiterhin eine wichtige Rolle bei Autoimmunerkrankungen und Infektionen im Magen-Darm-Trakt spielen und sollte daher in zukünftigen Therapieansätzen berücksichtigt werden.

Page generated in 0.0362 seconds