Conjectured in 1943, Hadwiger’s conjecture is one of the most challenging open problems in graph theory. Hadwiger’s conjecture states that if the chromatic number of a graph G is k, then G has a clique minor of size at least k. In this thesis, we give motivation for attempting Hadwiger’s conjecture for circular arc graphs and also prove the conjecture for proper circular arc graphs. Circular arc graphs are graphs whose vertices can be represented as arcs on a circle such that any two vertices are adjacent if and only if their corresponding arcs intersect. Proper circular arc graphs are a subclass of circular arc graphs that have a circular arc representation where no arc is completely contained in any other arc. It is interesting to study Hadwiger’s conjecture for circular arc graphs as their clique minor cannot exceed beyond a constant factor of its chromatic number as We show in this thesis. Our main contribution is the proof of Hadwiger’s conjecture for proper circular arc graphs. Also, in this thesis we give an analysis and some basic results on Hadwiger’s conjecture for circular arc graphs in general.

<p>BACKGROUND: The general comprehension of the populace is that the continent of Africa is very deprived. However, South Africa, the economic powerhouse in the Southern African region, has a stock exchange that rates amid the twenty largest in the world. With a well-developed infrastructure as well as democratic political system, the area has become increasingly more unwavering for companies disposed to invest. Reasons are cheap labour and availability of natural resources where South Africa has an abundant supply. However, there are also drawbacks to consider before investing in South Africa. Examples can be high criminality, high HIV-prevalence, lack of skilled workers and huge socio-economic disparities. Increased foreign direct investments and developed international trade can be means for South Africa to accelerate growth and employment and thereby contribute to a changed distribution of wealth and income in the country.</p><p>PURPOSE: The purpose with this thesis is to explore entering strategies of Swedish-related manufacturing companies that have entered South Africa. As a purpose extension our intention also includes exploring the organizational structure used in the subsidiary and whether any cultural circumstances affect the business climate.</p><p>METHOD: In our thesis the method chosen is a qualitative approach with in-depth interviews of people in, and associated to, Swedish-related manufacturing companies in South Africa. An interpretivistic and abductive perspective is used throughout the completion of the thesis.</p><p>CONCLUSION: Our study indicates that motives for investing in South Africa are merely on behalf of market penetration and utilization of the nation as a springboard towards the Sub-Saharan market. The entering strategy most frequently used is acquisitions and the organizational structure is multinational with an ethnocentric staffing approach. No cultural divergences between Swedes and South Africans interfere in the day-to-day business environment according to our study.</p>

Untersucht wird die Kapazität von Nebenströmen auf Knotenpunkten, die - mit dem Verkehrszeichen 301 bzw. 306 sowie dem Verkehrszeichen 205 geregelt werden, - keine abknickende Vorfahrt aufweisen, - auf zweistreifigen Stadtstraßen liegen und - eigene Fahrstreifen für Linksabbieger auf der Hauptstraße besitzen. Aufbauend auf vorhandenen Untersuchungen werden Auswirkungen von Fahrzeugstrom- und Straßencharakteristiken auf die Kapazität von Nebenströmen sowie verschiedene Aspekte des unmittelbaren Verkehrsablaufs auf Vorfahrtknoten analysiert. Fahrzeugstrom- und Straßencharakteristiken, die zu einer verstärkten Pulkbildung in übergeordneten Fahrzeugströmen führen, ziehen im Vergleich mit zufälligem Verkehrsfluss eine Kapazitätserhöhung nach sich. Mit Hilfe eines erstellten Bewertungsschemas ist es möglich, die Auswirkungen auf die Kapazität von Nebenströmen zu quantifizieren. Um die Interaktionen zwischen einander untergeordneten Fahrzeugströmen bei der Kapazitätsberechnung zu berücksichtigen, werden - die Wahrscheinlichkeit für rückstaufreien Zustand, - die Zusammensetzung des Hauptstroms von kreuzenden Fahrzeugen und Linkseinbiegern sowie - die Berechnung der Kapazität von Mischströmen mit Hilfe von Simulationen untersucht. Zur Berechnung der Wahrscheinlichkeit für rückstaufreien Zustand wird ein vereinfachtes Verfahren dargelegt, das auf bereits vorhandene Arbeiten aufbaut. Für die Zusammensetzung des Hauptstroms von kreuzenden Fahrzeugen und Linkseinbiegern werden die Ansätze aus früheren Untersuchungen präzisiert, indem die Interaktionen zwischen einander vorfahrtrechtlich untergeordneten Fahrzeugströmen stärker berücksichtigt werden. Eine Präzisierung erfährt ebenfalls der Ansatz für die Berechnung der gemeinsamen Kapazität von Mischströmen in Nebenstraßenzufahrten. Hierbei wird gezeigt, dass die gegenseitigen Behinderungen von Fahrzeugen innerhalb von Mischströmen, im Vergleich mit dem bisherigen Ansatz, zu einer niedrigeren gemeinsamen Kapazität führen.

<p>The purpose of this thesis is to look into the teaching methods and content in Zimbabwean biology education, and the possible influences that the teachers’ view of nature have on this education. The study was performed in and around Mutare in eastern Zimbabwe with eleven observations and six interviews in primary and secondary schools, corresponding to years four to nine in the Swedish compulsory school. </p><p>My study shows that the teachers’ view of nature is in many parts similar to the Swedish view of nature, but differ in a closer connection to religiosity and in a more every-day-life relation to nature. This is reflected in several of the concepts that view of nature consist of. The view of nature is influencing the content in biology partly. Since science hold universal concepts which are the same all around the world, the view of nature does not influence the scientific parts of biology, but have influence on where the emphases in the education is put. The results show no direct influence of the view of nature on teaching methods, but indirectly influenced by the choice of content.</p>

Whether a global greenhouse interval is a distinct or distant future, it is important to understand the dynamics of a greenhouse system. During such intervals the oceans, in the absence of sizeable polar ice caps, flood the continental shelf. The stratification and circulation of these epicontinental seas are open to debate, because there are no Recent analogs. The carbon and oxygen stable isotope record of fossil molluscan shell from epicontinental seas has the potential to reveal their stratification and seasonal cycles. Whether a global greenhouse interval is a distinct or distant future, it is important to understand the dynamics of a greenhouse system. During such intervals the oceans, in the absence of sizeable polar ice caps, flood the continental shelf. The stratification and circulation of these epicontinental seas are open to debate, because there are no Recent analogs. The carbon and oxygen stable isotope record of fossil molluscan shell from epicontinental seas has the potential to reveal their stratification and seasonal cycles. As a study sample, mollusks from the Baculites compressus and Baculites cuneatus biozones of the Western Interior Seaway of North America were collected from three locations: Kremmling, Colorado; Trask Ranch, South Dakota; Game Ranch, South Dakota. These fossils date to the Campanian (Late Cretaceous). Taxa include ammonites, bivalves, gastropods, and nautiloids. The first part of this investigation, described in Chapter 2, investigates the degree of alteration in these specimens. Elevated concentrations of minor elements such as magnesium and strontium reveal alteration from the original aragonite and/or calcite skeletons. Concentrations of these elements obtained by ICP-OES analysis are compared within several suites of specimens: mode of preservation, shell testing location, shell color, cementation, appearance under light microscope, and appearance under scanning electron microscope. Each of these suites tests a hypothesis about optimal shell preservation. Shell was found to be preserved best in shale rather than concretions, ammonite phragmacone rather than septa, opalescent specimens rather that nonopalescent ones, and uncemented shells rather than cemented shells, especially those with second-order versus first-order cement. Salinity and temperature values were derived for the organisms in the Western Interior Seaway: while bivalves produced unusually low temperatures, the others were reasonable for an inland sea. The second part of this study, described in Chapter 3, examines the isotopic record within exemplary mollusk shells, taken perpendicular to growth lines. The data for this investigation in sclerochronology documents the dominant isotopically enigmatic bottom-water habitat of the Inoceramus, the geochemical signature of the overlying water mass inhabited by Baculites, and short-term migrations between the two water masses in the nautiloid Eutrephoceras.

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This is a Minor Fields Study (MFS) project with the aim to facilitate the handling of empty PET bottles in Uganda. The eight weeks in Uganda gave an insight in how products are produced and how the waste surplus material is managed by local producers as well as factories. During the time in Uganda a problem concerning waste management of used PET-bottles was discovered as well as a need for a concept that facilitates the handling of PET bottles in restaurants and hotels. This thesis describes the development of a product prototype, which is designed by following product design process and from the knowledge gathered in Uganda. The product is designed to be manufactured and used in Uganda. The main purpose of the product is to compress used PET-bottles, to accomplish a size reduction. This will make it easier to gather the bottles and transport them to a recycling plant. / Detta är ett Minor Field Study (MFS) projekt som har resulterat i en prototyp till en produkt som ska underlätta hanteringen av använda PET-flaskor i Uganda. Projektet påbörjades i Uganda under 8 veckors tid, där man undersökte hur restmaterial hanteras i lokala verkstäder och fabriker. Då uppmärksammades ett stort behov av ett koncept som underlättar hanteringen av PET flaskor, främst i restauranger och hotell. Denna rapport beskriver hur en prototyp har utvecklats utifrån produktdesign metodik och erfarenheter i fält. Prototypen är utvecklad på så vis att den ska kunna byggas och användas i Uganda. Produktens huvuduppgift är att trycka ihop använda PET flaskor vilket medför en storleksminskning. Detta i sin tur underlättar förvaringen av flaskorna men underlättar också transporten till en återvinningsanläggning.

Contexte. Les phénotypes ABO et Rh(D) des donneurs de sang ainsi que des patients transfusés sont analysés de façon routinière pour assurer une complète compatibilité. Ces analyses sont accomplies par agglutination suite à une réaction anticorps-antigènes. Cependant, pour des questions de coûts et de temps d’analyses faramineux, les dons de sang ne sont pas testés sur une base routinière pour les antigènes mineurs du sang. Cette lacune peut résulter à une allo-immunisation des patients receveurs contre un ou plusieurs antigènes mineurs et ainsi amener des sévères complications pour de futures transfusions. Plan d’étude et Méthodes. Pour ainsi aborder le problème, nous avons produit un panel génétique basé sur la technologie « GenomeLab _SNPstream» de Beckman Coulter, dans l’optique d’analyser simultanément 22 antigènes mineurs du sang. La source d’ADN provient des globules blancs des patients préalablement isolés sur papiers FTA. Résultats. Les résultats démontrent que le taux de discordance des génotypes, mesuré par la corrélation des résultats de génotypage venant des deux directions de l’ADN, ainsi que le taux d’échec de génotypage sont très bas (0,1%). Également, la corrélation entre les résultats de phénotypes prédit par génotypage et les phénotypes réels obtenus par sérologie des globules rouges et plaquettes sanguines, varient entre 97% et 100%. Les erreurs expérimentales ou encore de traitement des bases de données ainsi que de rares polymorphismes influençant la conformation des antigènes, pourraient expliquer les différences de résultats. Cependant, compte tenu du fait que les résultats de phénotypages obtenus par génotypes seront toujours co-vérifiés avant toute transfusion sanguine par les technologies standards approuvés par les instances gouvernementales, les taux de corrélation obtenus sont de loin supérieurs aux critères de succès attendus pour le projet. Conclusion. Le profilage génétique des antigènes mineurs du sang permettra de créer une banque informatique centralisée des phénotypes des donneurs, permettant ainsi aux banques de sang de rapidement retrouver les profiles compatibles entre les donneurs et les receveurs. / Background. ABO and Rh(D) phenotyping of both blood donors and transfused patients is routinely performed by blood banks to ensure compatibility. These analyses are done by antibody-based agglutination assays. However, blood is not routinely tested for minor blood group antigens on a regular basis because of cost and time constraints. This can result in alloimmunization of the patient against one or more minor antigens and may complicate future transfusions. Study design and Methods. To address this problem, we have generated an assay on the GenomeLab SNPstream genotyping system (Beckman Coulter, Fullerton, CA) to simultaneously test polymorphisms linked to 22 different blood antigens using donor’s DNA isolated from minute amounts of white blood cells. Results. The results showed that both the error rate of the assay, as measured by the strand concordance rate, and the no-call rate were very low (0.1%). The concordance rate with the actual red blood cell and platelet serology data varied from 97 to 100%. Experimental or database errors as well as rare polymorphisms contributing to antigen conformation could explain the observed differences. However, these rates are well above requirements since phenotyping and cross-matching will always be performed prior to transfusion. Conclusion. Molecular profiling of blood donors for minor red blood cell and platelet antigens will give blood banks instant access to many different compatible donors through the set-up of a centralized data storage system.