Most life forms, including plants, are more or less susceptible to infection by pathogens. Whereas plant-pathogen interactions are well studied in human-managed systems they are less known in natural ecosystems. In this thesis the interactions between the sterilising anther-smut fungus Microbotryum silenes-dioicae and the host plant Silene dioica were studied in natural habitats in the Skeppsvik archipelago in northern Sweden. The purpose was to study some population characteristics that can potentially influence the colonization of anther-smut (Microbotryum silenes-dioicae) in young Silene dioica populations. Specifically, it was tested whether the population age, floral-  and total density, population size and distances to nearest diseased populations affect incidence of disease (presence of disease) and prevalence of disease (proportion of diseased individuals in populations) in younger host populations. It was found that incidence and prevalence of disease increased with host population age and size. In addition, it was seen that distances to diseased populations could not explain incidence or prevalence of disease. These results can potentially be used to predict disease risk in similar plant-pathogen systems.

The freshwater input from the Arctic into the North Atlantic is an important component of the global climate system through its effects on deepwater formation. Part of this freshwater is transported through the Canadian Arctic Archipelago (CAA) via sea ice and low density surface water, where it is able to set up buoyancy boundary currents (BBCs). To infer the existence of freshwater transport via BBCs in the southwest CAA, data are examined from summer cruises conducted in 1995, 1999, and 2000. The hydrographic data are supplemented with traditional knowledge relevant to this study. The presence, predominantly on the south side of channels, of driftwood originating from the Mackenzie River confirms an eastward transport through the region. The hydrographic data also show that the southwest CAA is relatively fresh compared to surrounding regions, and that the sources of buoyancy forcing are large and from different origins. The presence of BBCs on both sides of the channels appears to be a frequent occurrence with, as shown in previous work, the fresher water being more often present on the south shore. Some data from the summer 2000 show a different feature with much fresher water on the north side. A subsequent strong wind event creates a complete reversal of this situation, setting up a strong cross-channel horizontal salinity gradient and an amplified BBC on the south shore. In this region, buoyancy and wind forcing act together to force an eastward freshwater transport in the southwest CAA. / Graduate

På gränsen mellan hav och land, Haninge och Nynäshamn, naturreservat och lokalsamhälle, infinner sig Arschipelag skärgårdscenter. Genom överbryggandet av dessa gränsdragningar förankrar och sammanflätar projektet platsens olika element, för att skapa en knytpunkt tillgängliggjord från både fastlandet och Östersjön. Sammanstrålandet av gränserna sker i en vik intill Gamla Nynäsvägen, en bortglömd landremsa med vy över fjärden. Med utgångspunkt i ett behov av att tillgängliggöra åtkomst till vatten och angränsande naturreservat, synliggöra den kommunalt förbisedda tätorten samt nyttja de kommunikationsmöjligheter som läget erbjuder till sjöss och på land, har programmet formulerats. Som en nod för besökare från bägge håll syftar projektet till att uppmärksamma närområdets och skärgårdens kvalitéer genom ett skärgårdscenter som riktar sig mot en bred publik. En mötesplats och förankringspunkt för arkipelagens boende och aktörer, en lärande hubb som möjliggör kunskapsutbyte för besökare och en attraktion som aktiverar närområdet.  Med inspiration från platsens rika historia och marina typologier har projektet gestaltats med stundvis motsättande ledord; massivitet och lätthet, låg- och högteknologiskt, inramning och avskärmning. Närliggande fornlämningar har fått forma det beständiga markplanet, för att bära det symboliskt och geografiskt överbryggande övre planet. Fackverket sträcker ut sig horisontellt, ramar in den obrutna passagen till vattnet och landar lätt på det nedre fortet. / At the border between sea and land, Haninge and Nynäshamn, nature reserve and local community, Arschipelag archipelago Center emerges. By bridging these boundaries, the project anchors and interweaves the different elements of the site, creating a focal point accessible from both the mainland and the Baltic Sea. The convergence of borders takes place in a bay near Gamla Nynäsvägen, a forgotten strip of land with a view of the fjord. Based on the need to provide access to water and adjacent nature reserves, highlight the municipally overlooked urban area, and leverage the communication opportunities offered by the location both at sea and on land, the program has been formulated. As a node for visitors from both directions, the project aims to showcase the qualities of the surrounding area and the archipelago through an archipelago center that caters to a broad audience. It serves as a meeting place and anchor point for residents and stakeholders of the archipelago, a learning hub that enables knowledge exchange for visitors, and an attraction that activates the surrounding area. Inspired by the site's rich history and marine typologies, the project has been designed with occasionally contrasting keywords: solidity and lightness, low- and high-tech, framing and shielding. Nearby ancient remains have shaped the substantial ground plane, to carry the symbolically and geographically traversing upper plane. The truss structure extends horizontally, framing the uninterrupted passage to the water and gently landing on the lower fort.

Something essential in this project is to highlight the spirit of the archipelago. My project is creating spaces where you can experience the calm, the ruff, the warm and the cold. The sea can give such a variety of conditions. It changes with the seasons but it also changes with the weather and can quickly go from still breeze to full storm. It is a place that offers an escape in the same time as it ground you in the purest of realities. I have located my project at Landsort, in the south part of Stockholm archipelago, close to Nynäshamn. This part of the archipelago has a close connection to main land, and also takes you out fast to open sea. On Landsort I have created something I call Örum. In opposite of a Naturum, I want to preserve the possibility to explore the nature rather than preserve the nature itself. I believe the nature will change and the outer archipelago will be harder to visit. With my structures it will be possible to visit & explore Landsort for many years to come.

Submarine topographic features of the channels, sounds, fiords, and bays can best be explained as the products of extensive glacial excavation of a pre-existing drainage system. Troughs, hanging troughs, strings of deeps or basins, terminal sills, linear rises and depressions, and oversteepened deltas are considered direct or indirect evidence of glacial scour. Following glaciation, a negative movement of the Sverdrup Basin was accompanied by flooding of the northern part of the Archipelago. Only the upper portions of former interfluvial areas remained above sea level. These topographic highs are the present-day islands of the Canadian Arctic Archipelago. Statistical analyses of beach, fluvial, deltaic, and offshore marine sediments reveal characteristics that may be unique to polar deserts and ice-covered seas. Textures of beach and fluvial sediments are a function of associated relief and parent material. The deltaic environment is defined as that portion of the sea floor extending from the mouth of a river to approximately 3,200 feet from shore. Deltaic sediments show a progressive decrease in grain size seaward. Size distribution is related to the settling velocities of particles of different diameters. Offshore sediments have uniform textural properties. They are a combination of silt and clay (settled from suspension), and a minor but significant portion of sand- to granule-sized sediment (ice-rafted). An increase in mean grain size on the crests of submarine topographic highs suggests that winnowing by currents is taking place over these features. Two large areas of the sea floor lack a cover of Recent sediment. Organic carbon constitutes 0.84 to 2.14% of the offshore sediments. A dual source, terrigenous and phytoplanktonic, may explain the relatively high percentage of organic carbon. There is a positive correlation between percent organic carbon and amount of clay in the samples. Results of semiquantitative clay-mineral analyses of source rock, fluvial, deltaic, and offshore marine sediments indicate that montmorillonite, kaolinite, and illite are the dominant clay minerals. In this northern region, there is no change in clay mineralogy during weathering and transport. It is suggested that this may be characteristic of weathering under polar desert conditions. The mineralogy of parent materials on the islands controls the clay mineral distribution in offshore areas. In Louise Fiord, well-crystallized kaolinite is differentially flocculated close to shore. A study of the roundness of quartz grains of sand, silt, and clay size reveals that the distribution of this property is bimodal. Coarse and medium sands are well rounded, fine sands through coarse silts are angular, and fine silt and clay-sized particles are well rounded. High roundness of grains in the medium to coarse sand grades is attributed to abrasion. Well rounded quartz in the silt-clay size range is considered to be a product of solution. / text

Le réseau de signalisation qui répond à l’insuline et aux nutriments est conservé chez les métazoaires, où il joue un rôle central dans le contrôle du métabolisme et de la croissance. Les nutriments assimilés sont soit directement utilisés pour la croissance tissulaire, soit stockés principalement sous forme de triglycérides. Chez la drosophile, l’activation de ce réseau de signalisation dans le corps gras, un organe qui remplit à la fois les fonctions hépatiques et destockage, induit une augmentation du stockage de lipides sous forme de nombreuses gouttelettes lipidiques (LDs). A l’inverse, la carence alimentaire se traduit par une augmentation de la taille des LDs et une diminution de lipides stockés. La kinase TOR (TargetOf Rapamycine) et son substrat S6 Kinase (S6K) jouent un rôle central dans cette régulation.Chez la drosophile, ces 2 kinases (dTOR et dS6K) contrôlent les aspects autonome-cellulaireset hormonaux de la croissance. En dépit de nombreuses études sur divers organismes modèles,destinées à comprendre les mécanismes régulateurs de S6K, rien n’est connu à ce jour sur lecontrôle de sa dégradation.Nous avons utilisé une banque de lignées exprimant des ARN interférant (RNAi) contre unegrande quantité de gènes de la drosophile, pour réaliser 3 des cribles génétiques destinés à identifier de nouveaux régulateurs du métabolisme et de la croissance. Dans le premier crible,les RNAi ont été induits dans la glande prothoracique, siège de la production de l’hormonestéroïde ecdysone connue pour réguler la croissance et les étapes du développement, souscontrôle de la nutrition et de la signalisation dTOR. Sur 7000 gènes criblés, 620 ont étéidentifiés comme nécessaire à la production d’ecdysone. Dans le second crible, nous avonsexprimé les RNAi de 4000 gènes dans le corps gras pour rechercher ceux qui induisaient uneaugmentation de la taille des LDs. L’objectif était d’identifier des gènes impliqués dans la réponse à la carence alimentaire, et nous avons ainsi retenu 24 candidats intéressants. Le troisième crible représente la majeure partie du travail de thèse, où nous avons criblé les RNAi susceptibles de modifier un phénotype de croissance induit par dS6K. Sur 7000 gènes testés,nous en avons retenu 45 qui ont ensuite été utilisés pour générer un diagramme d’interaction en utilisant les informations disponibles dans les banques de données. Les candidats les plus intéressants ont ensuite été analysés en culture de cellules pour identifier ceux qui régulent l’activité de dS6K et ceux qui régulent sont niveau d’expression. Parmi ces derniers, nousavons identifié le gène codant pour Archipelago (Ago), connue pour contrôler la dégradationrégulée des protéines-cibles au niveau du protéasome. Nous avons réalisé de nombreusesexpériences qui montrent que ago et dS6K interagissent génétiquement. En outre, il est indiquédans les banques de données que ces protéines interagissent entre elles par la technique des 2-hybrides en levure. Tous ces résultats révèlent que Ago régule la dégradation de dS6K, etposent les premières pierres de ce niveau de régulation. / The evolutionary conserved insulin and nutrient signaling network regulates growth andmetabolism. Nutrients are directly utilized for growth or stored, mostly as triglycerides. InDrosophila, activation of insulin/nutrient signaling in the fat body (the fly equivalent of liverand adipose tissue), causes an increase in fat stores composed of several small-size lipiddroplets (LDs). Conversely, fasting produces an increase in LD size and a decrease in fatcontents. The TOR kinase and its substrate S6 kinase (S6K) play a central role in this response,and particularly in Drosophila, they have been shown to orchestrate cell-autonomous andhormone-controlled growth. However, despite extensive research studies on different modelorganisms (mouse, fly, worm) to decipher the molecular and physiological functions of S6K,nothing is known about how its degradation is regulated.Taking advantage of the inducible RNA interfering (RNAi) library from NIG (Japan), we haveperformed three genetic screens to identify novel regulators of steroidogenesis, lipidmetabolism and dS6K-dependent growth. First, RNAi lines were screened in the ring gland; anorgan that controls the progression of the developmental steps by producing the steroidhormone ecdysone. Out of 7,000 genes screened, 620 positive candidates were identified toproduce developmental arrest and/or overgrowth phenotypes. Then, we challenged 4,000 genesby RNAi screening able to recapitulate the larger sized LD phenotype as obtained uponstarvation, leading to the identification of 24 potential candidates. Finally, the RNAi lines werescreened for their ability to enhance a growth phenotype dependent of the Drosophila S6K(dS6K). Out of 7,000 genes screened, 45 genes were identified as potential negative regulatorsof dS6K. These genes were further used to design a novel protein-protein interaction networkcentered on dS6K through the available data from yeast-2-hybrid (Y2H) assay. The most potentinteractors were then analyzed by treatment of cultured S2 cells with the corresponding doublestrand RNA (dRNA). Western blotting thus, allowed us to discriminate between the geneproducts that regulate dS6K levels versus those that regulate its phosphorylation, as a hallmarkfor its kinase activity. Interestingly, archipelago (ago), which encodes a component of an SCFubiquitinligase known to regulate the degradation of dMyc, Cyclin E and Notch, was identifiedas a negative regulator of dS6K-dependent growth. Based on the Y2H available data showingthat Ago and dS6K interact each other and the presence of a putative Ago-interaction motif indS6K, we hypothesized that Ago causes an ubiquitin-mediated degradation of dS6K. Ourmolecular data showed that loss of ago caused an elevated level of dS6K, which confirms arole of Ago in controlling dS6K degradation. Altogether our findings emphasize the importanceof the saturating screening strategies in Drosophila to identify novel regulators of metabolicand signaling pathways.

The archipelago at the Swedish Baltic coast belonging to the landscapes Södermanland och Östergötland consists of many thousands of islands today. However, about 10 000 years ago, the first islands broke the sea surface due to the land uplift. Despite of the very exteme maritime environment at that time there exist archaeological remains from the mesolitical period from the first visitors. Since that time the maritime landscape has been used for several reasons, such as providing food, establishing industry, defence and trade. In the viking and medieval age the activity was high in the archipelago. This could only be possible with a safe journey between the islands with help from local fishermen who were the experts of the archipelago and severed as pilots as they know the safe routes and the placenamnes. The intention of this essay is to test if the phenomena called "name user circle" is present along the Swedish Baltic Sea coast of Södermanland and Östergötland. This means that a limitid group of people, geographically located, used the same placenamn for, in this case the placenamne Hamnskär (harbour islet). The frequensy and locality of Hamnskär will be studied as well as the historical och archaeological materiel. Other questions will be answered, such as common factors for Hamnskär, who used them, what were they used for, where did the users come from and who gave the islands their placenamnes. The result of the test is that ten Hamnskär have been found relatively frequently along the tested coast, except outside Södertörns coast, a part of Södermanland. Five "Bodskär" ("hut-islet") were located here. To go fishing in the outer archipelago you need a boat, a harbour and a hut, the use of these islets is the same. Archaeological materiel exits on some islets. The islets were used for fishing and for self-sufficiency. As the fishing was very income-generating a lot of people came to fish, even the Crown and burghers. Some other placenames have been found along the tested coast, Björkskär 18 and Alskär 26. The conclusion is that Hamnskär is a part of a local name user circle.

Master of Science / Department of Geology / Kirsten Nicolaysen / The Kerguelen Archipelago and the submarine Northern Kerguelen Plateau consist primarily of basalt erupted by the intraplate Kerguelen hotspot. The exposed volcanic rocks are tholeiitic basalts (29 Ma) followed by lesser alkalic basalts, highly alkaline phonolites, and syenites (24 Ma). This study presents the mineralogy, isotopic and geochemical compositions of lavas (n=59) from a 650 m section exposed in the wall of a glacial valley at Trois Menestrels in the Kerguelen Archipelago. This basalt section, exposed south of the Cook Ice Cap and closest to the Raillier du Baty alkalic plutonic complex, is further south and west of previously studied basalts exposed on the Plateau Central. Results of 40Ar/39Ar dating show the Trois Menestrels lavas erupted approximately 25 Ma, approximately contemporaneously with other Plateau Central lavas and thus provide an opportunity to examine spatial compositional variations within the Kerguelen hotspot. Though the Trois Menestrels lavas are tholeiitic, The samples plot on the tholeiitic field at the stratigraphic section of Trois Menestrels, 80% of lavas from Mt. Tourmente are transitional to alkalic in the younger rocks (25.6 Ma). This sequence of tholeiitic to transitional to alkalic compositions is mirrored at Mt. Capitole and Mt. Marion Dufresne. Sr, Ba, Pb, Nb, Zr versus Nb plots show similar patterns across the Plateau Central and abundances overlap within error. Variations in isotopic composition reveal that Trois Menestrels is rather homogeneous compared to the other sections. A fundamental issue that derives from these results is the close relationship between these different rocks of the various region of the Plateau Central.

Allt eftersom tekniken utvecklas blir elektrisk framdrift ett adekvat alternativ till konventionellt dieselmaskineri, särskilt inom den svenska skärgårdstrafiken eftersom det ofta handlar om korta distanser. En av de allra viktigaste faktorerna vid ett nybygge eller en konvertering av ett fartyg är kostnaden. Den här rapporten belyser de olika utmaningarna som ett mindre skärgårdsrederi möter vid en konvertering till elektrisk framdrivning. Det studien fokuserar på är vilka aspekter man behöver ta hänsyn till vid en konvertering, främst den ekonomiska aspekten och de miljövinster som en konvertering medför. Data har jämförts över hur mycket kostnaderna skiljer sig, för konverteringen och den framtida driften mellan hybriddrift och konventionell drift. Intervjuer har även genomförts med anställda på Koster Marin AB, som varit inblandade i konverteringen till hybriddrift av deras nyinköpta fartyg Kosterbris. Resultatet visar att hybriddrift är ett bättre alternativ än batteridrift för Koster Marin. / With the advance of technology electric propulsion is becoming a plausible alternative to conventional propulsion with diesel engines. Especially for the ferry traffic within the Swedish archipelago, where the conditions often are more favourable to alternatives like battery powered propulsion. One of the most important factors when building a ship or converting an existing one to hybrid propulsion is the cost. This study sheds light on the different challenges a small shipping company could face, when converting a ship. The study primarily focuses on the economic and environmental perspectives. A comparison has been made over the expenses for hybrid- and conventional propulsion, with the conversion and operation in mind. Interviews have also been conducted with employees of Koster Marin AB, who has been involved with the conversion of the company’s recently purchased vessel Kosterbris. The result shows that a hybrid solution is a better option than battery powered operation for Kosterbris.

Estimates from radiocarbon-dated packrat middens indicate that the high elevation woodland communities of the Madrean Sky Islands were continuous as recently as 8,000 to 12,000 years ago. A number of population studies on a diverse collection of taxa have investigated the extent to which the Madrean Sky Island system has limited gene flow among mountain ranges. The results of several of these studies indicate that population divergences may be more ancient than the Holocene. Yarrow’s spiny lizards, Sceloporus jarrovii, were sampled from eight sites representing seven mountain ranges. The populations of S. jarrovii are host to the malarial parasite, Plasmodium chiricahuae. DNA sequences from the lizards and their malarial parasites were used to reconstruct the evolutionary relationships and estimate the ages of the populations for both host and parasite. The findings of these analyses indicate that the sky island populations of S. jarrovii have been isolated for hundreds of thousands of years and did not experience gene flow during the last woodland expansion. In contrast, the results indicate that the malarial infection occurred more recently, possibly during the Holocene woodland expansion. In addition, the prevalence of the malarial infection was compared to multiple attributes of the lizards. This analysis revealed a negative relationship between the genetic diversity of the lizard populations and the prevalence of infection. Furthermore, lizard populations with lower prevalence of infection have a lower frequency of multiclonal infections.