Solving Nonlinear Aeronautical Problems Using the Carleman Linearization Method

Many problems in aeronautics can be described in terms of nonlinear systems of equations. Carleman developed a technique to linearize such equations that could lead to analytical solutions of nonlinear problems. Nonlinear problems are difficult to solve in closed form and therefore the construction of such solutions is usually nontrivial. This thesis will apply the Carleman linearization technique to three model problems: a two-degree of-freedom (2DOF) ballistic trajectory, Blasius\u27 boundary layer, and Van der Pol\u27s equation and evaluate how well the technique can adequately approximate the solutions of these ordinary differential equations

GPS NAVIGATOR FOR VISUALLY IMPAIRED

The objective of this study is the development of navigation system which supports activities of the visually impaired without help of others. This system navigates a visually impaired person by using information about GPS (Global Positioning system). In this navigation system, after setting the destination, position of user is obtained by GPS and a visually impaired user is guided along the predefined route

Show me what you share and I’ll tell you who you are

Viral marketing is a technique employing consumers as a market force to spread messages in social networks, almost like a virus. The challenge with viral marketing is knowing how it works. We argue that previous research has focused too much on the content of the messages, rather the ones who actually share them. The purpose of this study is to gain deeper insights into viral marketing from a consumer perspective, focusing on the aspects consumers find significant when sharing material online. By conducting qualitative interviews our findings show that even though the respondents were active on social media, they were quite passive users. Our analysis show that what consumers decided to share were contingent upon the purpose of the share, the messages had higher significance than the content. Our analyses show that sharing viral messages is not seen as an innocent share, but rather elements in the respondents identity construction.Viral marknadsföring är en metod som använder konsumenter som en marknadsföringskraft för att sprida budskap i sociala nätverk, likt ett virus. Utmaningen med viral marknadsföring är att förstå hur metoden fungerar. Vi menar att tidigare forskning mest fokuserat på innehållet av materialet snarare än de som faktiskt delar dem. Syftet med denna studie är att erhålla djupare kunskap och förståelse av viral marknadsföring utifrån ett konsumentperspektiv genom att fokusera på de aspekter som konsumenterna anser vara viktiga när material delas på nätet. Genom att genomföra kvalitativa intervjuer har våra upptäckter visat att även om respondenterna var aktiva i sociala medier, var de relativt passiva i sitt själva användande. Analysen visar att vad konsumenter väljer att dela är kopplat till syftet med själva delningen, budskapet är större än själva materialets betydelse. Vår analys visar även att delningar inte är bara är simpla delningar, det är snarare ett verktyg för respondentens identitetsuppbyggnad

Effect of sibling competition and male carotenoid supply on offspring condition and oxidative stress

Early developmental conditions have major implications for an individual's fitness. In species where offspring are born simultaneously, the level of sibling competition for food access is intense. In birds, high sibling competition may subject nestlings to decreased growth rate as a result of limited food and increased levels of oxidative stress through high metabolic activity induced by begging behaviors. We manipulated the level of sibling competition in a natural population of great tits and assessed the consequences for nestling body condition and resistance to oxidative stress. In a full factorial design, we both augmented brood size to increase sibling competition and supplemented the male parents with physiological doses of carotenoids thereby doubling the natural carotenoid intake, aiming at increasing the males' investment in current reproduction and thereby decreasing sibling competition. Nestling body mass was reduced by the brood enlargement and enhanced by the carotenoid supplementation of fathers. Nestling resistance to oxidative stress, measured as total antioxidant defenses in whole blood, was not influenced by the treatments. Because nestlings experience high metabolic activities, an absence of an effect of sibling competition on free radicals production seems unlikely. Nestling body mass decreased and resistance to oxidative stress tended to increase with initial brood size, and hence these correlational effects suggest a trade-off between morphological growth and development of the antioxidant system. However, the result of the experimental treatment did not support this trade-off hypothesis. Alternatively, it suggests that nestling developed compensatory mechanisms that were not detected by our antioxidant capacity measur

Reproductive effort transiently reduces antioxidant capacity in a wild bird

Oxidative stress has been suggested as a proximate cost of reproduction and hence as a major constraint in the evolution of life histories, and it is therefore thought that antioxidants alleviate the effects of reproductive effort on oxidative stress. Furthermore, carotenoid-based ornaments have been proposed to mirror male ability to resist oxidative stress. Using a full-factorial experimental design in a natural population of great tits Parus major, we manipulated brood size and supplemented the male parent with either carotenoids or a placebo. We then assessed antioxidant capacity via a measure of whole blood resistance to a free radical attack during the nestling rearing period. Males of enlarged broods showed impaired antioxidant capacity 5 days after the brood size manipulation. However, 13 days after manipulation, they had their antioxidant capacity restored, an effect that may be due to the development of compensatory antioxidant mechanisms or due to reduced investment in the current reproduction in favor of future survival and reproduction. Carotenoid supplementation did not affect male antioxidant capacity nor was the interaction with the brood manipulation significant. Males with stronger carotenoid-based plumage colors did not show higher antioxidant capacity 5 days after the brood size manipulation, but after 13 days, the relationship was highly significant. This study on a natural population shows that larger brood size can induce a transient decrease in antioxidant capacity. It also supports the hypothesis that carotenoid-based plumage may signal male ability to resist oxidative stress, particularly during the energetically demanding nestling rearing perio

Becoming moss - reimagining vitality by thinking and making-with moss in the seasons of Finland

Recently, there has been a growing interest in exploring the relationships between humans and the more-than-human world, particularly in the field of art. Through this thesis, I seek to contribute to this discourse by exploring the potential of interdisciplinary artistic research and creative practices as a means of fostering a deep relational attunement with the living being of moss. Its proliferous and proteiform being entered my life in subtle shades of green, whispering of an ancient and unfathomable connection to time and to the origins of life itself. It has elicited in me a desire to develop bonds of intimacy and understanding with its ecology, temporality, and spirit, encouraging an artistic inquiry which will form the base upon which this thesis stands. This inquiry draws on the posthuman, and new materialist turn in the arts, which emphasizes the entangled and dynamic relationships between humans and nonhumans, as well as the decolonial lens that seeks to challenge the Western-centric worldview that has contributed to the exploitation and destruction of the earth and its inhabitants. By examining the potential of artistic practices to foster a renewed sense of relational attunement with more-than-human life, as well as their vitalist and animistic underpinnings, this thesis will attempt to contribute to ongoing efforts towards ecological and social justice, and the cultivation of more ethical and sustainable ways of living in the world. Becoming Moss is structured around four seasonal chapters and a concluding section exploring future research directions, each centered around a distinctive artwork, project, or medium, where thinking and making come together in a symbiotic dance to inform my mossy worldings and theoretical reflection on vitalist perspectives. It draws on the theory of wonder as a pathway to the fascinating world of moss and examines how the incorporation of the scientific study of moss has been reflected by shifts in my language and understanding, leading to a weaving of knowledge. Each chapter will be linked to my temporal encounters with moss over the course of a year’s seasons, providing a rich and nuanced understanding of moss’s ecology, temporality, and spirit over time. Through interlacing sections of creative writing, practice-led research, and transdisciplinary inquiry, I hope to offer a new way of seeing and experiencing the world of moss, one that is grounded in a deep appreciation of its temporal and ecological complexity. This thesis situates itself within the socio-cultural and ecological landscape of Finland, which has informed my artistic drive and practice, as well as upcoming collaborative endeavors

So kommen wir besser voran

SO KOMMEN WIR BESSER VORAN So kommen wir besser voran / Gaude, Almut (CC BY-SA) ( -

Mitochondrial metabolism in cancer transformation and progression

Cancer cells undergo a multifaceted rewiring of cellular metabolism to support their biosynthetic needs. Although the major determinants of this metabolic transformation have been elucidated, their broad biological implications and clinical relevance are unclear. In this study, I systematically analysed the expression of metabolic genes across 20 different cancer types and investigated their impact on clinical outcome. I found that cancers undergo a tissue-specific metabolic rewiring, which converges towards a common metabolic landscape. Of note, downregulation of mitochondrial genes is associated with the worst clinical outcome across all cancer types and correlates with the expression of epithelial-to-mesenchymal transition (EMT) gene signature, a feature of invasive and metastatic cancers. Consistently, suppression of mitochondrial genes is identified as key metabolic signature of metastatic melanoma and renal cancer, and metastatic cell lines. This comprehensive analysis reveals unexpected facets of cancer metabolism, with important implications for cancer patients stratification, prognosis, and therapy. I then investigated how mitochondrial dysfunction could affect cell behaviour. I capitalised on a recently developed in vitro cell model with increasing levels of m.8993T>G mutation heteroplasmy. I found that impaired utilisation of reduced nicotinamide adenine dinucleotide (NADH) by the mitochondrial respiratory chain leads to cytosolic reductive carboxylation of glutamine as a new mechanism for cytosol-confined NADH recycling supported by malate dehydrogenase 1 (MDH1). This metabolic coupling is facilitated by the formation of a multienzymatic complex between MDH1 and GAPDH. Importantly, such metabolic coupling between glutamine metabolism and cytosolic NADH recycling is able to support increased glycolytic flux, an important hallmark of cells with dysfunctional mitochondria, as well as cancer cells. Finally, increased glycolysis in cells with mitochondrial dysfunction is associated with enhanced cell migration, in an MDH1-dependent fashion. These results describe a novel link between glycolysis and mitochondrial dysfunction, and uncover potential targets for cells that rely on aerobic glycolysis for proliferation and migration, such as cancer cells.MRC DTA studentshi

Nitrogen deficiency in Arabidopsis affects galactolipid composition and gene expression and results in accumulation of fatty acid phytyl esters

Nitrogen is an essential nutrient for plants because it represents a major constituent of numerous cellular compounds, including proteins, amino acids, nucleic acids and lipids. While N deprivation is known to have severe consequences for primary carbon metabolism, the effect on chloroplast lipid metabolism has not been analysed in higher plants. Nitrogen limitation in Arabidopsis led to a decrease in the chloroplast galactolipid monogalactosyldiacylglycerol (MGDG) and a concomitant increase in digalactosyldiacylglycerol (DGDG), which correlated with an elevated expression of the DGDG synthase genes DGD1 and DGD2. The amounts of triacylglycerol and free fatty acids increased during N deprivation. Furthermore, phytyl esters accumulated containing medium-chain fatty acids (12:0, 14:0) and a large amount of hexadecatrienoic acid (16:3). Fatty acid phytyl esters were localized to chloroplasts, in particular to thylakoids and plastoglobules. Different polyunsaturated acyl groups were found in phytyl esters accumulating in Arabidopsis lipid mutants and in other plants, including 16:3 and 18:3 species. Therefore N deficiency in higher plants results in a co-ordinated breakdown of galactolipids and chlorophyll with deposition of specific fatty acid phytyl esters in thylakoids and plastoglobules of chloroplasts