The Io UV footprint (IFP) is one of the most spectacular signatures of the Io-Jupiter interaction. It consists of several auroral spots and an extended tail which are located close to the feet of the magnetic field lines passing through Io in each hemisphere. The purpose of the present study is to demonstrate that a careful analysis of the Io UV footprint based on observations acquired with the STIS and ACS high resolution and high sensitivity FUV cameras on board the Hubble Space Telescope can provide us with essential information on the ongoing physical processes. The thesis is organized around basic questions: What is the Io footprint?, Where is the Io footprint?, How high is the Io footprint?, How big is the Io footprint? and finally: How bright is the Io footprint? The answers to these questions have profound implications for the understanding of the phenomenon. Among the most important results of this work is the unexpected finding of a faint auroral spot appearing upstream of the main Io spot in one hemisphere while only downstream spots are seen in the opposite hemisphere. The detailed study of the evolution of the inter-spot distances puts previous models describing the footprint morphology under question. We propose a new interpretation which involves that some spots are caused by electrons accelerated away from the planet along the field lines in one hemisphere, crossing the equatorial plane in the form of electron beams and precipitating in the opposite hemisphere, creating the so-called Trans-hemispheric Electron Beam (TEB) spots. The information provided by the position of the satellite footprints is not restricted to the interaction between the moon and the Jovian magnetosphere. The analysis of the footpaths of Io, Europa and Ganymede helped us to further constrain the magnetic field models, notably through the identification of a large magnetic anomaly in the northern hemisphere. Additionally, the study of the speed of the Io footprint along its reference contour suggests that a second anomaly regions may also exist in the North. In this work, we present a new and direct method to measure the altitude of the different footprint features. The main spot and the tail emissions have a peak altitude of 900 km while the peak altitude of the Trans-hemispheric Electron Beam spot is 700 km. These results suggest that the main spot and tail emissions are caused by the precipitation of electrons with a mean energy around 1 keV, far lower than the 55 keV value previously derived from spectral measurements. The vertical extent of these emissions is surprisingly broad (scale height ~400 km) and is best fitted with an incoming kappa electron energy distribution (spectral index ~2.3). This suggests that the electron acceleration is supplied by processes related to inertial Alfvén waves rather than by quasi-static potentials as proposed by some theoretical models. The size of the main footprint spot is carefully estimated on a much larger image sample than before: its length along the footpath is ~900 km while its width perpendicular to the footpath is <200 km. Larger lengths are sometimes observed but in that case, they are attributed to the mix of individual spots. The spot length is larger than the projected diameter of Io around the magnetic field lines but is consistent with recent simulations. As far as the Io footprint brightness is concerned, variations on two timescales have been studied. On timescales of minutes, systematic brightness fluctuation on the order of 30% (and going up to 50%) are observed. Additionally, cases of simultaneous variations of the main and the TEB spots are reported, which suggests that the process that triggers these fast variations is located close to the planet. Variations of the main spot brightness with the System III longitude of Io are also analyzed. Our new measurement method fully considering the multi-spot structure of the IFP and the real geometry of the observations provides more accurate estimates for the precipitating energy flux (between 100 and 500 mW/m for the main spot). The main spot brightness peaks at 110° and 290° longitude, which could be attributed either to an enhanced interaction strength when Io is near the dense torus center or to spots merging which is also observed to occur in these sector. Nevertheless, strong North-South asymmetries are also observed, which suggests that the surface magnetic field strength also influences the spots brightness. ---------------------------------------------------------------------- L'empreinte aurorale d'Io est l'une des signatures les plus impressionnantes de l'interaction Io-Jupiter. Présente dans chaque hémisphère, elle se situe à proximité des pieds des lignes de champ magnétique qui interceptent Io et se compose de plusieurs taches suivies d'une longue trainée. Cette étude vise à démontrer qu'une analyse minutieuse de l'empreinte UV d'Io basée sur les observations des instruments STIS et ACS du Télescope Spatial Hubble peut apporter des informations cruciales sur les processus physiques qui sont en jeu. Cette thèse est organisée autour de questions relativement basiques: Qu'est-ce que l'empreinte d'Io?, Où se trouve-t-elle?, A quelle altitude se trouve-t-elle?, Quelle est sa taille? et enfin Quelle est sa brillance?. Les réponses à ces questions ont de profondes implications pour la compréhension du phénomène. Parmi les résultats principaux de ce travail, il y a la découverte inattendue d'une faible tache aurorale apparaissant en amont de la tache principale dans un hémisphère alors que les seules taches observées dans l'hémisphère opposé sont situées en aval. L'étude détaillée de la distance inter-taches remet en question les précédents modèles décrivant la morphologie de l'empreinte. Nous proposons ici une nouvelle interprétation de certaines de ces taches: elles seraient causées par des électrons initialement accélérés le long des lignes de champ dans la direction opposée à Jupiter, qui ensuite traverseraient le plan équatorial sous la forme de faisceaux d'électrons et qui précipiteraient finalement dans l'hémisphère opposé en générant la tache du Faisceau d'Electrons Trans-hemisphérique (FET). Les informations fournies par la position des empreintes de satellites ne se limitent pas à l'interaction entre Io et la magnétosphère de Jupiter. L'analyse des contours parcourus par les empreintes d'Io, d'Europe et de Ganymède permet de mieux contraindre les modèles de champ magnétique joviens, entre autre à travers l'identification d'une importante anomalie magnétique dans l'hémisphère nord. De plus, l'étude de la vitesse de l'empreinte d'Io le long du contour de référence suggère qu'elle pourrait être accompagnée d'une deuxième anomalie dans cet hémisphère. Dans cette étude, nous présentons une méthode directe pour mesurer l'altitude des différentes sous-structures qui forment l'empreinte. Le pic d'émissions de la tache principale et de la trainée est situé à 900 km d'altitude alors que celui de la tache FET est à 700 km. Ces résultats suggèrent que la tache principale et la trainée sont la conséquence de la précipitation d'électrons ayant une énergie moyenne d'approximativement 1 keV, une valeur largement inférieure aux 55 keV déduits à partir de précédentes mesures spectrales. L'extension verticale de ces émissions est étonnamment large (hauteur d'échelle: ~400 km) et la distribution d'énergie des électrons incidents qui reproduit au mieux les observations est une distribution kappa d'indice spectral ~2.3. Cela suggère que l'accélération des électrons est liée à des ondes d'Alfvén inertielles plutôt qu'aux potentiels quasi-statiques proposés par certains modèles théoriques. La taille de la tache principale a été mesurée sur un ensemble d'images beaucoup plus étendu qu'auparavant: sa longueur le long du contour est de ~900 km alors que sa largeur telle que mesurée perpendiculairement à celui-ci est de <200 km. Des longueurs plus importants sont parfois observées mais elles résultent de la superposition partielle de plusieurs taches individuelles. La longueur des taches est plus grande que la projection du diamètre d'Io le long des lignes de champ, ce qui était prévu par des simulations récentes. En ce qui concerne la brillance des taches, deux échelles de temps ont été étudiées en particulier. A l'échelle de la minute, nous avons mis en évidence des fluctuations de l'ordre de 30% de la brillance moyenne et pouvant atteindre jusqu'à 50 % de celle-ci. Dans certains cas, on observe des variations corrélées de la tache principale et de la tache FET, ce qui suggère que le processus qui induit ces variations rapides se situe près de la surface de Jupiter. Les variations de la brillance de la tache principale en fonction de la longitude Système III d'Io ont également été analysées. Notre nouvelle méthode de mesure prend pleinement en compte la géométrie de l'observation ainsi que le fait que l'empreinte est composée de différentes taches, ce qui permet une estimation plus précise du flux d'énergie incident (entre 100 et 500 mW/m pour la tache principale). La brillance de la tache principale possède deux maxima, un à 110° et un autre à 290° de longitude. Ces augmentations de brillance peuvent avoir deux origines: soit elles sont dues à l'augmentation de l'intensité de l'interaction entre Io et le plasma quand Io est proche du centre du tore, soit elles sont liées à la superposition des taches principales et FET qui se produit également dans ces secteurs. Néanmoins, de fortes asymétries Nord-Sud sont aussi observées, ce qui semble indiquer que l'intensité du champ magnétique de surface joue aussi un rôle en ce qui concerne la brillance des spots.

Myc oncogenes encode transcription factors that bind to E-box sequences in DNA, driving the expression of a large number of target genes and are deregulated in approximately 70% of human cancers. Deregulated Myc expression cause enhanced proliferation (which is counteracted by apoptosis), angiogenesis and cancer. Though Myc’s importance in induction of S phase has been established, less is known about its functions in the G2 and M phases of the cell cycle. Paper I addresses the targeting of the Myc targets Aurora kinase A and B that have roles in G2/M transition and provide evidence that pharmaceutical Aurora kinase inhibition causes cell cycle arrest and apoptosis in a Myc-selective manner and is useful in treating Myc-induced lymphomas in vivo. The assumption that the important target genes responsible for the biological effects of Myc overexpression were those encoding components of the cell cycle machinery lead to little interest in other potentially important groups of target genes. However, recent work challenged this view by indicating that Myc target genes encoding metabolic enzymes may be critical for Myc-induced tumorigenesis. Importantly, the targeting of Myc target genes encoding metabolic enzymes has the potential of providing a new treatment strategy of Myc-induced cancers. Paper II covers the pharmaceutical targeting of the Myc-induced spermidine synthase (Srm) that shows promise as a tool for chemoprevention by affecting proliferation, but not for the treatment of established tumors. Paper III focuses on the negligible effect an Ldha mutation has on Myc- induced lymphomagenesis. Ldha has long been known to be a Myc target gene and in vitro experiments have recently indicated it to be important for transformation. It seems the negligible effect of the Ldh mutation can be explained by the high frequency of loss of either Arf or p53 in this mouse model, since enforced Ras-Myc oncogenic cooperation in soft agar assays of Ldh mutant MEFs effectively inhibits colony formation, and λ-Myc;Ldh mutant bone marrow infected with oncogenic Ras does not give rise to tumors when transplanted into wild-type mice. A role for Ldh in the ability of tumors to evade the immune system was also indicated in this study. The combined experiences and very different outcome of the three studies included in this thesis draw attention to the value of in vivo assessment of Myc downstream targets in Myc-induced lymphomagenesis.

Research has shown fear of childbirth to be as common among men as women, but the phenomenon has not been as studied among men. Some men have trouble talking about their fear and therefore don’t get the support that they need. Where to go to get help is not so obvious for these men. The name mostly used for this clinic is Aurora. Men and women come here to get help and support to process their fears and plan for the upcoming delivery. Aurora is also available after a traumatic deliver to process the experience. The aim of this study was to describe men’s experiences of Aurora clinics as husband/partner accompanying a woman with fear of childbirth, and to investigate the existence of fear among the men themselves. Questionnaires were sent to 41 men, of who 27 answered who took part in Aurora clinic at a hospital in south of Sweden. The data was analyzed descriptive, with Chi-2 test and Wilcoxon Signed Ranks Test. The results showed that all part taking men suffered from fear of childbirth to some extent, but the men chose to take part in Aurora mainly to support the woman. The men felt confirmed, supported and taken seriously. Most men had a positive childbirth experience after taking part in Aurora. A surprising find was that few men stated that a birth plan had been established, even thou this should be routine. The findings were surprisingly positive. The midwife giving antenatal care, is the one how should identify fear of childbirth in men and women, but no specific measures are taken to find them. In our study we found several men who were afraid of childbirth, who hadn’t been discovered before. Screening all parents-to-be for fear of childbirth could possibly be a way to find more. / Studier visar att förlossningsrelaterad rädsla och oro är ungefär lika vanligt hos män som hos kvinnor, men ämnet är inte lika väl belyst ur ett manligt perspektiv. Vissa män har svårt att tala om sin rädsla och får därför inte det stöd de behöver. Vart de rädda männen ska vända sig för att få hjälp är heller inte alltid så självklart. Den verksamhet som finns för förlossningsrädda kallas oftast Auroraverksamhet. Hit kan kvinnor och män vända sig för att få stöd och hjälp att bearbeta sin rädsla och planera inför kommande förlossning. Det finns även möjlighet till kontakt med Aurora efter traumatisk förlossning för att bearbeta händelsen. Syftet med denna studie var att undersöka mäns erfarenheter av Auroraverksamheten som medföljande make/sambo till förlossningsrädd kvinna, samt förekomst av rädsla/oro hos männen själva. En enkät skickades ut till 41 män som deltagit vid Auroraverksamheten vid en kvinnoklinik i södra Sverige, 27 svarade. Studien hade en kvantitativ ansats. Studien analyserades med deskriptiv statistik, Chi-2 test och Wilcoxon Signed Ranks Test. Resultatet visade att alla män som deltog i studien själva upplevde viss förlossningsrädsla. Trots detta hade männen till största del deltagit för att stötta kvinnan. Vid besöken på Aurora kände sig männen bekräftade, hjälpta och tagna på allvar. De flesta hade en positiv förlossningsupplevelse efter besöken. Ett förvånande resultat var att få av männen uppgav att en förlossningsplan upprättats, då detta bör vara rutin vid Auroraverksamheten. Resultaten var överraskande positiva. Barnmorskorna på mödrahälsovården är de som ska identifiera förlossningsrädsla hos både kvinnor och män, men i dagsläget görs inga speciella åtgärder för att finna dem. Möjligen kan någon form av screening göra att fler får hjälp, då vi genom enkätens frågor funnit flera ej tidigare identifierade förlossningsrädda män.

The main purpose of this stydy was to evaluate the Aurora clinic (for women afraid of birth/delivery) in the south of Sweden. Questionnaires were sent to 197 women who had contact with the Aurora clinic during 2007 and 2008. The group of participants contained both pregnant women and women who have given birth. A total of 136 women replied. The results showed that both the average age and the level of education of the women were high. Nulli-paras and multi-paras had different reasons for fearing delivery. The study also showed that most women felt that the contact with an Aurora midwife helped them to feel secure and to be better prepared before delivery, that the midwife understood them and took them seriously and that the content of the meetings was satisfactory. Three out of four women, who initially wished for a caesarean section, subsequently accepted a normal delivery. This study supports previous research that shows the importance of the supportive conversation provided at the Aurora clinic for women with fear of delivery.

The maintenance of normal cell function and tissue homeostasis is dependent on the precise regulation of multiple signaling pathways that control cellular decisions to either proliferate, differentiate, arrest cell growth, or initiate programmed cell death (apoptosis). Cancer arises when clones of mutated cells escape this balance and proliferate inappropriately without compensatory apoptosis. Deregulated cell growth occurs as a result of perturbed signal transduction that modulates or alters cellular behavior or function to keep the critical balance between the rate of cell-cycle progression (cell division) and cell growth (cell mass) on one hand, and programmed cell death (apoptosis, autophagy) on the other. AGC kinases are activated downstream of a wide range of extracellular stimuli by distinct mechanisms. AGC kinase members such as Aurora-A and Akt regulate fundamental cellular functions including cell cycle, cell growth and survival. Inappropriate activation of those kinases has been associated with the development of diseases such as diabetes, autoimmunity, and cancer. The molecular mechanism of AGC kinases including Aurora-A and Akt involved in human cancers indicates that Aurora-A and Akt are important targets for cancer therapeutic strategies. We demonstrate, for the first time, that Aurora-A interacts with AR and phosphorylates AR at Thr282 and Ser293 in vitro and in vivo. Aurora-A induces AR transactivation activity in a phosphorylation-dependent manner. Ectopic expression Aurora-A in LNCaP cells induces the PSA expression and cell survival whereas knockdown of Aurora-A sensitizes LNCaP-RF cells to apoptosis and cell growth arrest. These data indicate that AR is a substrate of Aurora-A and that elevated Aurora-A could contribute to androgen-independent cell growth by phosphorylation and activation of AR. The NACHT leucine-rich repeat protein 1 (NALP1) is a member of the Ced-4 family and locates at chromosome 17p13.2 near TP53 locus. Here we demonstrated frequent somatic mutations and epigenetic silence of the NALP1 in human non-small cell lung, breast, ovarian and colon cancer. Restoration of NALP1 resulted in the inhibition of tumorigenic activity of the cell lines with NALP1 alterations. In addition to apoptosis, the cells expressing NALP1 largely undergo autophagy. Expression of NALP1 induces PI3KC3 kinase activity through directly interacts with Beclin 1, a protein required for activation of PI3KC3. Moreover, Akt phosphorylates NALP1 and disrupts the interaction between NALP1 and Beclin 1, leading to abrogation of NALP1-induced PI3KC3 activation and autophagy. Taken collectively, these data indicate that the NALP1 is a novel tumor suppressor gene on chromosome 17p13 and plays an important role in tumorigenesis by regulation of Beclin 1/PI3KC3 autophagic pathway and that Akt inhibits autophagy through regulation of NALP1/Beclin/ PI3KC3 cascade.

LAMBDA was an exploration of science and art in two components: a performance-lecture and an art installation. This project asserted that performance and art are effective methods of delivering scientific information to a general audience. The first component was a solo performance-lecture that used lights, projection, costumes, props, and sound in a hybrid classroom space. The performance-lecture covered the topics of light, the Aurora Borealis, gravitational lensing, and the cosmic microwave background. The art installation used light emitting objects to visually represent the gravitational disturbances that exist within a section of space-time. / text

<p>Bytt namn till Sam Holmqvist</p>

Io, the innermost Galilean satellite of Jupiter, exhibits a wide variety of complex phenomena such as interaction with Jupiter’s magnetosphere, volcanic activity, and a rarefied multi-species sublimating and condensing atmosphere with an ionosphere. Io’s orbital resonance with Jupiter and the other Galilean satellites produces intense tidal heating. This makes Io the most volcanically active body in the solar system with plumes that rise hundreds of kilometers above the surface. In the present work, the interaction of Io’s atmosphere with the Jovian plasma torus is simulated via the Direct Simulation Monte Carlo (DSMC) method and the aurora produced via electron-neutral excitation collisions is examined using electron transport Monte Carlo simulation. The electron-transport Monte Carlo simulation models the electron collisions with the neutral atmosphere and their transport along field lines as they sweep past Io, using a pre-computed steady atmosphere and magnetic field. As input to the Monte Carlo simulation, the neutral atmosphere was first modeled using prior 2D sunlit continuum simulations of Io’s atmosphere produced by others. In order to justify the use of a sunlit atmosphere for eclipse, 1D two-species (SO2 and a non-condensable) DSMC simulations of Io’s atmospheric dynamics during and immediately after eclipse were performed. It was found that the inclusion of a non-condensable species (SO or O2) leads to the formation of a diffusion layer which prevents rapid collapse. The degree to which the diffusion layer slowed the atmospheric collapse was found to be extremely sensitive to both the initial non-condensable mole fraction and the reaction (or sticking) probability on the surface of the “non-condensable”. Furthermore, upon egress, vertical stratification of the atmosphere occurred with the non-condensable species being lifted to higher altitudes by the rapid sublimation of SO2 as the surface warms. Simulated aurorae (specifically the [OI] 6300 Å and the S2, SO, and SO2 molecular band emission in the middle ultraviolet) show good agreement with observations of Io in eclipse and an attempt was made to use the simulations to constrain the upstream torus electron temperature and Io’s atmospheric composition, structure, and volcanic activity. It is found that the position of the bright [OI] 6300 Å wake spot relative to Io’s equator depends on the position of Io relative to the plasma torus’ equator and the asymmetric electron number flux that results. Using HST/STIS UV-Vis spectra, the upstream electron temperature is weakly constrained to be between 3 eV and 8 eV depending on the flux of a low energy (35 eV), non-thermal component of the plasma (more non-thermal flux requires lower thermal plasma temperatures to fit the spectrum). Furthermore, an upper limit of 5% of the thermal torus density (or 180 cm−3 based on the Galileo J0 plasma density at Io) is obtained for the low energy non-thermal component of the plasma. These limits are consistent with Galileo observations of the upstream torus temperature and estimates for the the non-thermal component. Finally, plume activity and S2 content during eclipse observations with HST/STIS were constrained by examining the emission intensity along the spatial axis of the aperture. During the August 1999 UV-Vis observations, the auroral simulations indicate that the large volcanoes Pele and Surt were inactive whereas Tvashtar was active and that Dazhbog and possibly Loki were also actively venting gas. The S2 content inferred for the large Pele-type plumes was between 5% (Tvashtar) and 30% (Loki, if active), consistent with prior observations (Spencer et al., 2000; Jessup et al., 2007). A 3D DSMC simulation of Io’s sublimation and sputtered atmosphere including photo- and plasma-chemistry was developed. In future work these atmospheric simulations will replace the continuum target atmosphere in the auroral model and thus enable a better match to the observed high altitude auroral emission. In the present work, the plasma interaction is modeled by a flux of ions and electrons which flow around and through Io’s atmosphere along pre-computed fields and interact with the neutral gas. A 3D DSMC simulation of Io’s atmosphere assuming a simple thermal model for the surface just prior to ingress into eclipse and uniform frost coverage has been performed in order to understand how Io’s general atmospheric dynamics are affected by the new plasma model with chemistry and sputtering. Sputtering was found to supply most of the nightside atmosphere (producing an SO2 column of ~5×1013 cm−2); however, the dense dayside sublimation atmosphere was found to block sputtering of the surface. The influence of the dynamic plasma pressure on the day-to-night circumplanetary flow was found to be quite substantial causing the day-to-night wind across the dawn terminator to flow slightly towards the equator. This results in a region of high density near the equator that extends far (~2000 km for the condensable species) onto the nightside across the dawn terminator. Thus, even without thermal lag due to rotation or variable surface frost, highly asymmetric equatorial column densities relative to the subsolar point are obtained. The non-condensable O2, which is a trace species on the dayside, is the dominant species on the nightside despite increased SO2 sputtering because the loss rate of O2 is slow. Finally, a very intriguing O2 flow feature was observed near the dusk terminator where the flow from the leading hemisphere (pushed by the plasma) meets the flow from the dayside trailing hemisphere. Since the O2 does not condense on the surface, it slowly convects towards the poles and then back onto the nightside, eventually to be dissociated or stripped away by the plasma. / text

Measurements with satellite and sounding rocket borne instruments contain important information on remote and local processes in regions containing matter in the plasma state. The characteristic features of the particle distributions can be used to explain the morphology and dynamics of the different plasma populations. Charged particles are lost from a region due to precipitation into the atmosphere, charge exchange processes, or convection to open magnetic field lines. The sources of the Earth’s magnetospheric plasma are mainly ionization and extraction of upper atmosphere constituents, and entry of solar wind plasma. The intensity and distribution of auroral precipitation is controlled in part by the conditions of the interplanetary magnetic field causing different levels of auroral activity. Acceleration of electrons and positive ions along auroral field lines play an important role in magnetospheric physics. Electric fields that are quasi-steady during particle transit times, as well as fluctuating fields, are important for our understanding of the behaviour of the plasma in the auroral region. High-resolution data from the Swedish Viking and the Swedish/German Freja satellites have increased our knowledge considerably about the interaction processes between different particle populations and between particles and wave fields. This thesis describes acceleration processes influencing both ions and electrons and is based on in-situ measurements in the auroral acceleration/heating region, with special emphasis on; processes at very high latitudes, the role of fluctuating electric fields in producing so called electron conics, and positive ion heating transverse to the geomagnetic field lines. / <p>Diss. (sammanfattning) Umeå : Umeå universitet, 1994, härtill 6 uppsatser.</p> / digitalisering@umu.se

No description available.