Even though low mass stars (< 8 solar masses) vastly outnumber high mass stars (< 8 solar masses), the more massive stars drive the chemical evolution of galaxies from which the next generation of stars and planets can form. Understanding mass loss of asymptotic giant branch stars contributes to our understanding of the chemical evolution of the galaxy, stellar populations, and star formation history. Stars with mass < 8 solar masses form planetary nebulae, while those with mass < 8 solar masses go supernova. In both cases, these stars enrich their environments with elements heavier than simple hydrogen and helium molecules. While some general info about how stars die and form planetary nebulae are known, specific details are missing due to a lack of high-resolution observations and analysis of the intermediate stages. For example, we know that mass loss in stars creates morphologically diverse planetary nebulae, but we do not know the uniformity of these processes, and therefore lack detailed models to better predict how spherically symmetric stars form asymmetric nebulae. We have selected a specific group of late-stage stars and observed them at different scales to reveal the uniformity of mass loss through different layers close to the star. This includes observing nearby masers that trace the molecular shell structure around these stars. This study revealed detailed structure that was analyzed for uniformity to place constraints on how the mass loss processes behave in models. These results will feed into our ability to create more detailed models to better predict the chemical evolution of the next generation of stars and planets.

Tese de mestrado integrado. Engenharia Electrotécnica e de Computadores (Major em Energia). Faculdade de Engenharia. Universidade do Porto. 2009

Tese de mestrado integrado. Engenharia Mecânica. Faculdade de Engenharia. Universidade do Porto. 2009

IntroductionThe STARx Questionnaire was designed with patient and provider input, to measure self-management and transition skills in adolescents and young adults (AYA) with chronic health conditions. With proven reliability and an empirically-based factor structure, the self-report STARx Questionnaire requires further validation to demonstrate its clinical and research utility. In this study we examine the concurrent, predictive, and discriminant validity of the STARx Questionnaire.MethodsTo examine concurrent validity, the STARx Questionnaire was compared to two other published transition readiness tools. Predictive validity was examined using linear regressions between the STARx Total Score and literacy, medication adherence, quality of life, and health services use. Discriminant validity was examined by comparing the performance of three chronic illness conditions on the STARx Total Score and associated subscales.ResultsThe STARx Questionnaire and its subscales positively correlated with the scores for both transition readiness tools reflecting strong concurrent validity. The STARx Questionnaire also correlated positively with the literacy, self-efficacy, and adherence measures indicating strong predictive validity; however, it did not correlate with either quality of life or health care utilization. The performance of AYA across three different clinical conditions was not significant, indicating the clinical utility of this HCT tool for a variety of chronic health conditions.ConclusionThe strong validity of the STARx Questionnaire, in tandem with its strong reliability, indicated adequate psychometric properties for this generic self-report measure. These strong psychometric properties should contribute to the STARx being a viable measure of health care transition for both research and clinical purposes.

Les étoiles de masse intermédiaire (2M⊙ ≤ M ≤ 10M⊙) sont parmi les sources dominantes du champ interstellaire FUV dans la Galaxie. Elles régulent les phases du milieu interstellaire et l’ensemble des processus de formation stellaire galactique. Alors que les protoétoiles de type solaire et massives ont été et continuent à faire l’objet de nombreuses études, la formation des étoiles intermédiaires a été relativement peu étudiée. Leur structure physique, composition chimique et leur richesse moléculaire sont un domaine à explorer.L’objectif de ma thèse est d’obtenir un recensement détaillé et aussi complète que possible des propriétés physico-chimiques d’une protoétoile isolée de masse intermédiaire. Notre choix s’est porté sur Cep E-mm (100 L⊙).J’ai pour cela complété un relevé spectral de l’émission moléculaire dans les bandes (sub)millimétriques entre 72 et 350 GHz avec le télescope de 30m de l’IRAM. La sensibilité des observations a permis d’identifier la présence de nombreuses molécules complexes organiques (COMs) dans l’enveloppe de la protoétoile, mais aussi, plusieurs espèces moléculaires inhabituelles dans le jet généré par la protoétoile. Des observations complémentaires avec le télescope de 30m ont permis de cartographier l’émission moléculaire à grande échelle (20’’ à 11’’ ; 15000 à 8000 UA). En parallèle, des cartes interférométriques de l’émission moléculaire entre 86 – 90 GHz et 216 – 220 GHz ont été obtenues avec l’interféromètre de l’IRAM (NOEMA) à 1.4’’ (1000 UA) de résolution angulaire. Ces observations m’ont permis d’obtenir une première description de la distribution de l’émission moléculaire au sein de l’enveloppe, des grandes échelles, dans les parties extérieures de l’enveloppe étendue, aux petites échelles dans la région d’un hot corino. Les études présentées ici ont suivi un travail méticuleux de réduction et d’analyse des données, single-dish et interférométriques. Plus précisément, j’ai identifié et séparé les contributions à l’émission détectée dans le lobe du télescope de 30m de l’IRAM des différentes régions physiques du cœur protostellaire. De ce fait, j’ai identifié et caractérisé quatre composantes physiques qui diffèrent par leurs propriétés spectroscopiques et leurs conditions d’excitation : l’enveloppe étendue, le hot corino, le flot bipolaire basse vitesse et le jet à haute vitesse. Enfin, l’anisotropie de la distribution de brillance du flot et du jet bipolaire ne peut pas être modélisée par l’approche ‘’classique’’ d’une source gaussienne. J’ai développé des outils spécifiques semi-analytiques pour calculer de manière approchée, et plus raisonnable, le couplage entre le lobe du télescope et la source. / Intermediate-mass stars (2 M⊙ ≤ M ≤ 10 M⊙) are among the dominant sources of FUV interstellar field in the Galaxy. They regulate the phases of interstellar medium and the whole process of galactic star formation. While solar-type and massive protostars have been and continue to be the subject of many studies, the formation of intermediate stars has been relatively little studied. Their physical structure, chemical composition and molecular richness are still a subject to explore.The aim of my thesis is to obtain a detailed census, as complete as possible ,of the physical and chemical structure of an isolated intermediate-mass protostar: Cep E-mm (100 L⊙).I have completed a spectral survey of the molecular emission in the (sub)millimetre bands between 72 and 350 GHz with IRAM 30m telescope. The sensitivity of the observations made it possible to identify the presence of numerous complex organic molecules (COMs) in the protostar envelope, but also several unusual molecular species in the protostellar jet. Additionally, further observations with the IRAM 30m telescope made it possible to map the molecular emission at large scale (20’’ to 11’’; 15000 to 8000 AU). In parallel, interferometric maps of the molecular emission between 86 – 90 GHz and 216 – 220 GHz were obtained with NOEMA, the IRAM interferometer, at 1.4’’ (1000 AU) of angular resolution. These observations allowed me to obtain the distribution of molecular emission within the source, from large scales in the outer parts of the extended envelope, to the small scales in the hot corino region. The single-dish and interferometric observations were reduced and analysed in a meticulous manner. More precisely, I identified and separated the molecular emission contribution from the different physical regions as observed with the IRAM 30m telescope. I have identified and characterized fours physical components that differ in their spectroscopic properties and excitation conditions: the extended envelope, the hot corino, the bipolar outflow and the high-velocity jet. Finally, the anisotropy of the brightness distribution from the outflow system cannot be modelled by the “classical” Gaussian approach. I have developed specific tools to estimate, in a semi-analytical manner, the coupling between the telescope lobe and the source.

This paper unpacks the franchise system and the often-tumultuous relationship between Producers and Consumers, especially around the release of new films by the Producers. Star Wars represents far more than just a corporate product. There is a thriving ecosystem around pieces that have touched fans lives personally. The reaction of fans to new media texts in existing franchises is in constant flux. Tumultuous emotions of betrayal come in waves from fans immediately following the release of new content. Specifically focusing on reception to prequel films, Episode 1: The Phantom Menace (1999) and Solo: A Star Wars Story (2018), reveals how both generational differences and technology affect fan interaction and reaction across iterations of the franchise. Fans attempt to remediate the differences in cannon and their own interpretations of the franchise through fan creation. Fans have historically been early embracers of new technologies and have used increasingly available editing software and cameras to express their passion for the franchise. A digital world has created ever expanding platforms of interactivity in which Producers/Consumers can reach one another. The spaces in which these interactions occur have evolved from personal fan websites to social media sites. The amount of online information available to consumers, from reviews to fan content, has diminished the power of official franchise content. The release of Solo revealed a dangerous level of apathy from consumers. As opposed to the fervor surrounding powerful media texts at the time of The Phantom Menace, the diversified media landscape has undoubtedly affected Star Wars.

Since performers first became credited for their on-screen work in the early twentieth century, stardom has been understood as a primary factor distinguishing cinema as a unique, discrete art form. Much of the work done by canonical film scholars emphasizes film as a continuous medium defined by relation, as well as the irreducible value of human presence in creating meaning that transcends the boundaries of film. These are important cornerstones of star studies, a subfield within film studies that interrogates how film performers accrue and project meaning and value. They also isolate continuity as a singular tool for developing approaches to understanding cultural and ideological value of film stars – determining why certain stars are such powerful commodities and addressing the deceptively elusive question of what they actually mean. Through careful inspection of the transactions between film production and culture, my dissertation – “He’ll Just Be Paul Newman Anyway: Film Continuity and the Star Image” – pursues two primary goals regarding the cultivation of stardom and our understanding of star persona. First, I reestablish the star image as a discrete force, informed by on-screen performances and off-screen biography but remaining distinct from both (following the framework of French film theorist Edgar Morin). I attempt to disentangle these figures, asserting star image – the intangible, ethereal collection of values, expectations, and investment constituted from both performer and character – as the central mechanism for interpreting human presence. Second, I explore the notion that narrow range of performance and on-screen consistency are more essential to developing stardom than the revelation of the performer’s actual self. This position applies both to the production of stars and to our critical understanding of them, creating compelling connections to central debates of film studies. In doing so, my goal is to reassert the star as the most valuable and definitive source of meaning in film. The combination of Paul Newman’s on-screen continuity, enduring persona, and career trajectory (rising to stardom during the fall of the studio system) makes him uniquely valuable for understanding the evolution of film stardom and encourages new perspective on the development and deployment of star image. Moreover, Newman is an ideal subject for investigating the star image as a discrete force and the function of range in its development. Through critical examination of his on-screen tendency to “go his own way,” I demonstrate the immense value stars can offer to our understanding of the moving image and surrounding culture(s). Moreover, in asserting star persona as a discrete force integral to interpreting the meaning of human presence in film, I also cultivate a contextual understanding of the rebel archetype in response to changing dominant cultural ideologies. In doing so, my work directly addresses valuable questions essential to and extending beyond film studies: why stardom is essential to defining film and understanding how it signifies, how star persona is accumulated and deployed in individual films and across a whole career, and what meanings are generated and revealed by the star as an projection of social values and ideals.

This thesis attempts to better understand how film reboots empower fans by offering unique insight as critiques of the original texts and by displacing hierarchies amongst audience, critic, and author. My hypothesis is that reboots, as an act of adaptation, allow audience members of the original franchise to become authors, in this case screenwriters. By extension these screenwriters become critics by highlighting, expanding, or even disregarding themes found in the original film series. This complicates the reboot beyond a simple capitalistic venture to make money and invites us to consider the way they position and displace interactants to better foster critical engagement with works of art, specifically films.

Compact Objects (Neutron Stars) form in the last moments of a star's life, during the violent events known as supernovae. As the star's core fusion falters, matter undergoes a dramatic gravitational compression resulting in internal densities rivaling subatomic particles. Ever since their discovery in the mid-twentieth century, these highly magnetized and rapidly rotating balls of condensed matter have provided a bountiful playground for astronomers seeking out exotic physics. Neutron Stars that emit electromagnetic radiation are seen by observers as Pulsars, named such for the pulse of intensity as the pulsar's radiation beam passes into our line of sight. These beams are comprised of two unique regions with differing phenomenology; core emission that arises close to the pulsar polar cap and centered within the radiation beam, and higher altitude conal emission that lies along the beam's periphery. While pulsars can and do emit over a wide frequency range, most known pulsars are seen as radio sources, at sensitivities where studies of the pulsar single-pulses allows us to probe the rich details of the plasma-filled pulsar magnetosphere. Even then, the radio emission often has a steep spectra, restricting the frequencies in which radio telescopes can study pulsars. We have utilized the unmatched sensitivity of Arecibo Observatory to conduct a multi-frequency single-pulse survey, between 327 MHz and the novel 4.5 GHz, of Arecibo's brightest high-frequency pulsars. The broad frequency range and single-pulse resolutions have allowed us to set accurate beam classifications for these nearly two dozen pulsars while extending constraints on important population trends to higher frequencies. Several of the pulsars in our survey exhibit deviant behavior, and are thus useful as followup case studies to further our understanding of pulsar radio emission. One of the most interesting cases involves pulsar B0823+26, where we find evidence for an age-dependent death-line separating core and conal dominated pulsars, suggesting that the plasma generating capabilities of a pulsar changes as they age. For the other three, they fall in the ``Partial Cone'' class; a type of pulsar that is characterized by strong delays in their emission. We find that all three of these pulsars show evidence of core emission.

This thesis examines the nature and impact of the Reagan administration’s self-described projection of “peace through strength.” It argues that Reagan’s defense spending surge, “Star Wars” (SDI) missile shield policy, and 1983 invasion of Grenada gave the president confidence and political cover that allowed him to withdraw U.S. Marines from Beirut in early 1984. Analysts and commentators focus on his muscular power projection like defense spending, SDI, and the invasion of Grenada, but in practice Reagan exercised a high level of restraint in troop deployment. These projections of power and the avoidance of protracted war in Lebanon gave Reagan further confidence and cover to pursue arms control negotiations with the Soviet Union, against the protestations of anti-Soviet hardliners. Although Reagan supporters have credited the administration with either frightening or bankrupting the Soviets into disarmament, these policies—particularly his military restraint in Lebanon—did more to bring Reagan himself to the negotiation table. These power projection measures contributed to a “peace through strength” narrative embraced by much of Reagan’s domestic audience, allowing him to fend off accusations of Munich-style appeasement. While the defense spending surge helped give Reagan the confidence to ink an arms control agreement, the buildup created nonlinear consequences that will outlive arms control treaties.