38 resultados para In Between Space and Space-Times


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Placental insufficiency is one major cause of intrauterine growth restriction and also relates to neurodevelopment. Preterm infants with very low birth weight are at risk of postnatal growth restriction as well as neurodevelopmental impairments. However, the optimal postnatal growth for long-term neurodevelopment is still unclear. The objective of this study was thus to investigate the association between growth and neurodevelopment in very preterm infants. The study populations consisted of 83 (I), 55 (II), 36 (III) and 181 (IV) infants with very low birth weight (below 1501 grams), and very or extremely low gestational age (below 32 and 26 weeks). Foetal blood circulation in relation to two-year neurodevelopment and the association between early growth and brain maturation at term age were studied. Postnatal growth, and its association with five-year cognitive outcome, was analysed. Changes in foetal blood circulation related to placental insufficiency associated with an adverse two-year cognitive outcome. Early postnatal growth in extremely preterm infants was comparable to a similar Swedish cohort. Preterm infants with slow intrauterine growth had less mature brains at term age; rapid catch-up growth until term age did not eliminate this difference. Weight gain and head circumference growth from birth until two years of age associated positively with five-year cognitive outcome in appropriate for gestational age infants. In small for gestational age infants, head circumference growth from term age to four months (corrected age) associated positively with their five-year cognitive outcome. The association between postnatal growth and neurodevelopment was different for prenatally normally grown versus slow grown preterm infants.

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The along-scan radiometric gradient causes severe interpretation problems in Landsat images of tropical forests. It creates a decreasing trend in pixel values with the column number of the image. In practical applications it has been corrected assuming the trend to be linear within structurally similar forests. This has improved the relation between floristic and remote sensing information, but just in some cases. I use 3 Landsat images and 105 floristic inventories to test the assumption of linearity, and to examine how the gradient and linear corrections affect the relation between floristic and Landsat data. Results suggest the gradient to be linear in infrared bands. Also, the relation between floristic and Landsat data could be conditioned by the distribution of the sampling sites and the direction in which images are mosaicked. Additionally, there seems to be a conjunction between the radiometric gradient and a natural east-west vegetation gradient common in Western Amazonia. This conjunction might have enhanced artificially correlations between field and remotely-sensed information in previous studies. Linear corrections may remove such artificial enhancement, but along with true and relevant spectral information about floristic patterns, because they can´t separate the radiometric gradient from a natural one.

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Living organisms manage their resources in well evolutionary-preserved manner to grow and reproduce. Plants are no exceptions, beginning from their seed stage they have to perceive environmental conditions to avoid germination at wrong time or rough soil. Under favourable conditions, plants invest photosynthetic end products in cell and organ growth to provide best possible conditions for generation of offspring. Under natural conditions, however, plants are exposed to a multitude of environmental stress factors, including high light and insufficient light, drought and flooding, various bacteria and viruses, herbivores, and other plants that compete for nutrients and light. To survive under environmental challenges, plants have evolved signaling mechanisms that recognise environmental changes and perform fine-tuned actions that maintain cellular homeostasis. Controlled phosphorylation and dephosphorylation of proteins plays an important role in maintaining balanced flow of information within cells. In this study, I examined the role of protein phosphatase 2A (PP2A) on plant growth and acclimation under optimal and stressful conditions. To this aim, I studied gene expression profiles, proteomes and protein interactions, and their impacts on plant health and survival, taking advantage of the model plant Arabidopsis thaliana and the mutant approach. Special emphasis was made on two highly similar PP2A-B regulatory subunits, B’γ and B’ζ. Promoters of B’γ and B’ζ were found to be similarly active in the developing tissues of the plant. In mature leaves, however, the promoter of B’γ was active in patches in leaf periphery, while the activity of B’ζ promoter was evident in leaf edges. The partially overlapping expression patterns, together with computational models of B’γ and B’ζ within trimeric PP2A holoenzymes suggested that B’γ and B’ζ may competitively bind into similar PP2A trimmers and thus influence each other’s actions. Arabidopsis thaliana pp2a-b’γ and pp2a-b’γζ double mutants showed dwarfish phenotypes, indicating that B’γ and B’ζ are needed for appropriate growth regulation under favorable conditions. However, while pp2a-b’γ displayed constitutive immune responses and appearance of premature yellowings on leaves, the pp2a-b’γζ double mutant supressed these yellowings. More detailed analysis of defense responses revealed that B’γ and B’ζ mediate counteracting effects on salicylic acid dependent defense signalling. Associated with this, B’γ and B’ζ were both found to interact in vivo with CALCIUM DEPENDENT PROTEIN KINASE 1 (CPK1), a crucial element of salicylic acid signalling pathway against pathogens in plants. In addition, B’γ was shown to modulate cellular reactive oxygen species (ROS) metabolism by controlling the abundance of ALTERNATIVE OXIDASE 1A and 1D in mitochondria. PP2A B’γ and B’ζ subunits turned out to play crucial roles in the optimization of plant choices during their development. Taken together, PP2A allows fluent responses to environmental changes, maintenance of plant homeostasis, and grant survivability with minimised cost of redirection of resources from growth to defence.

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The thesis examines the phenomenon most commonly known as “ayahuasca tourism” – i.e. the practice of westerners traveling to South America and partaking in ceremonies in which a powerful entheogenic brew, ayahuasca, is consumed. While this popular phenomenon has been steadily increasing during the last decades, it has, however, been insufficiently studied by scholars. An important question which has not been properly addressed in earlier studies is how ayahuasca tourism relates to the wider occurrence of travel and how it should be perceived with reference to the theoretical frameworks on the subject of travel. Drawing on theories regarding pilgrimage and tourism, the main purpose of this thesis is to examine the relationship between ayahuasca tourism and the broader spectrum of travel. In particular, the study tests the designations “pilgrimage”, “religious tourism” and “spiritual tourism” with reference to ayahuasca tourism. Utilizing earlier literature as well as ayahuasca tourists‟ reports obtained from an Internet forum as a basis for analysis, I search for a suitable terminology to be used for the phenomenon. The study lays special emphasis on the protagonists‟ motivations, experiences and outcomes in order to take note of various aspects of the wide-ranging occurrence of ayahuasca tourism. Key findings indicate that ayahuasca tourism is best understood as a combination of pilgrimage and tourism. On the basis of the analysis I argue that ayahuasca tourism should be labeled as “pilgrimage” and/or “spiritual tourism”, and the tourists respectively as “pilgrims” and/or “spiritual tourists”. The category of “religious tourism/tourist”, on the other hand, turns out to be an inappropriate designation when describing the phenomenon. In general, through my study I show that the results are consistent with the present trend in the study of travel to perceive pilgrimage and tourism as theoretically similar phenomena. The study of ayahuasca tourism serves thus as living proof of contemporary travel, in which the categories of pilgrimage and tourism are often indistinguishable. I suggest that ayahuasca tourism is by no means exceptional on this point, but can rather be used as an illustration of modern travel forms on a general level. Thus, the present study does not only add to the research of ayahuasca tourism, but also provides additional insights into the study of travel.

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This dissertation centres on the themes of knowledge creation, interdisciplinarity and knowledge work. My research approaches interdisciplinary knowledge creation (IKC) as practical situated activity. I argue that by approaching IKC from the practice-based perspective makes it possible to “deconstruct” how knowledge creation actually happens, and demystify its strong intellectual, mentalistic and expertise-based connotations. I have rendered the work of the observed knowledge workers into something ordinary, accessible and routinized. Consequently this has made it possible to grasp the pragmatic challenges as well the concrete drivers of such activity. Thus the effective way of organizing such activities becomes a question of organizing and leading effective everyday practices. To achieve that end, I have conducted ethnographic research of one explicitly interdisciplinary space within higher education, Aalto Design Factory in Helsinki, Finland, where I observed how students from different disciplines collaborated in new product development projects. I argue that IKC is a multi-dimensional construct that intertwines a particular way of doing; a way of experiencing; a way of embodied being; and a way of reflecting on the very doing itself. This places emphasis not only the practices themselves, but also on the way the individual experiences the practices, as this directly affects how the individual practices. My findings suggest that in order to effectively organize and execute knowledge creation activities organizations need to better accept and manage the emergent diversity and complexity inherent in such activities. In order to accomplish this, I highlight the importance of understanding and using a variety of (material) objects, the centrality of mundane everyday practices, the acceptance of contradictions and negotiations well as the role of management that is involved and engaged. To succeed in interdisciplinary knowledge creation is to lead not only by example, but also by being very much present in the very everyday practices that make it happen.