Dissertations / Theses on the topic 'Regenerative change'

Background: Climate change has become the most pressing challenge of our time. Current business approaches to sustainability are instrumental that may portray sustainability as a source of corporate profit rather than acting for change beyond mitigation and adaptation. A regenerative approach to sustainability challenges current practices and aims to create and strengthen environmental and social well-being. Purpose: The purpose of this study is to deepen the understanding of how change agents can be a part of a regenerative sustainability transition. This is done by investigating the attitudes of change agents to such a transition. The aim is to contribute to theoretical and practical implications of organizational change theory, addressing the phenomena of organizational regenerative sustainability. Method: The paradigm of this study is of critical realist nature with an exploratory research design. An abductive model inspired the research approach, and semi-structured interviews were performed to collect primary data. A thematic analysis was then performed to draw conclusions from this study. Results: The analysis uncovered both welcoming and reluctant attitudes toward a regenerative transition. The welcoming attitudes were inherently more optimistic toward a regenerative transition, whereas change agents with reluctant attitudes identified more challenges and barriers for implementing a regenerative transition simultaneously as their perspectives were more business-centered. When weighing the evidence, it appears that the welcoming attitudes are relatively more likely to have a positive impact on implementing regenerative change as well as succeed with the initiation.

Food embodies our most intimate relationship with nature. We ingest it to survive. Without it, perish. Through time humans have physically distanced the places of food cultivation from human inhabitation. In recent decades green planning initiatives embraced urban agriculture as a critical element of sustainable communities. However, current approaches to bring food cultivation into cities require labor, capital, and physical resources that are often unavailable in sufficient quantity, quality, or duration for provisioning sites to be considered sustainable. Within each pillar of sustainability - economy, ecology, and equity - barriers exist. Rooted in indigenous land stewardship and food provisioning practices, permaculture (permanent agriculture) offers strategies and tactics to overcome those barriers. Despite mounting evidence that permaculture will result in more sustainable food systems, adoption is limited. Social aesthetics is the term employed by cultural theorists to describe how institutions, social groups, and collective projects codify their values and beliefs. The diffusion of innovation theory suggests that ideas and information from a highly specialized world require translation into a language the rest of society understands to reach widespread adoption. This thesis translates permaculture to contribute to a sustainable social aesthetic for food provisioning and change American food culture. The translation occurs on iconic public land - 'America's front yard'. In 1901 the National Mall was envisaged to serve as a stage on which democratic values are expressed and became the prototype for America's City Beautiful movement. Today, its carpet of lawn framed by American Elm trees epitomizes the economic, ecological, and equity challenges of monoculture landscapes. This project aims to express democratic values through polyculture. It invites every citizen to participate in acts of justice rather than submit to illusions of order and control. From site selection through design, spatial and temporal scale is critical. This thesis explores food's past to understand our present and imagine our future. The design creates an immersive food experience that equips visitors with the knowledge and resources to apply permaculture at the homestead, neighborhood, city, and regional scales. The remade front yard becomes the symbol of a country where places of food cultivation and human inhabitation are one and the same.
Master of Landscape Architecture
Food embodies our most intimate relationship with nature. We ingest it to survive. Without it, perish. Through time humans have slowly increased the distance between where we grow our food (the country) and where we live (the city). In the process, we have built a system where millions of people either suffer from diet-related illnesses or experience hunger on a regular basis. We have damaged our soils and introduced chemicals that have contaminated our waters and polluted our air. We have built a system that both contributes to and is threatened by climate change. Our relationship with nature has become toxic. For decades there have been movements to change, transform, or replace the food system. In cities across the country, these movements appear as organic food in grocery stores, community gardens, urban farms, farmers' markets, farm-to-table restaurants, and more recently, food forests. The problem is each requires labor, capital, and physical resources that are often unavailable in sufficient quantity, quality, or duration for them to be sustainable, let alone scalable. What if there is another way to grow food - a way that heals the soil, decontaminates water, supports biodiversity, and provides enough for everyone? Rooted in indigenous land stewardship and food provisioning practices, permaculture (permanent agriculture) offers strategies and tactics to reverse the negative impacts of the existing food system. Despite mounting evidence that permaculture will result in more sustainable food systems, adoption is limited. For it to become mainstream, someone has to translate it into a language society understands. I try to do that through this thesis. My translation occurs on iconic public land - 'America's front yard'. In 1901 the National Mall was imagined to serve as a stage on which democratic values are expressed and became the prototype for America's City Beautiful movement. Today, its carpet of lawn framed by American Elm trees epitomizes the economic, ecological, and equity challenges of monoculture landscapes. This project aims to express democratic values through polyculture. This thesis explores food's past to understand our present and imagine our future. The design creates an immersive food experience that equips visitors with the knowledge and resources to apply permaculture at the homestead, neighborhood, city, and regional scales. The remade front yard becomes the symbol of a country where places of food cultivation and human inhabitation are one and the same.

The dissertation investigates the formative influence of hydrology in shaping the spatiality and socio-economic production processes of the urban environment. It acknowledges the surging pattern of human development, the unprecedented growth of cities and the reality of climate change to propose an intervention which aims to introduce the concept of Regenerative Architecture to a South African context. The intervention manifests as an Integrated Biotectural System for the Production and Reclamation of Water, a new architectural typology which is adapted to suit local conditions and to provide innovative possibilities for socio-economic production. The site of the intervention is located behind the G Berth in the Duncan Dock of the Port of Cape Town, extending up the Heerengracht Axis, the most prominent remnant of the formative influence of hydrology on the City of Cape Town. The intervention proposes to form part of a larger Continuous Productive Urban Landscape defined by water, which connects Robben Island – a UNESCO World Heritage Site – from Duncan Dock, through the Heerengracht, Adderley Street, the Company’s Gardens, Orange Street and De Waal Park through to Table Mountain. The intervention acts as a productive landscape that regenerates the connection between the city, the hidden and inaccessible shorelines and the socio-economic production processes those shorelines inherently represent. It harvests the heritage and cultural resources of a historically productive City of Cape Town to present the socio-economic production possibilities of the future: the generation of water and food and the regeneration of land within the urban environment. Copyright
Dissertation (MArch(Prof))--University of Pretoria, 2011.
Architecture
Unrestricted

Background: The importance of sustainability is growing; however, the mindset of many businesses remains in the profit-driven take-make-waste economy, aiming for limitless growth. Humanity cannot continue with business-as-usual, and a paradigm shift must occur to ensure a future for the planet. SMEs represent 99% of the businesses in the EU, and to ensure a safer tomorrow for all, they need to evolve to reach sustainable development and capture the opportunities of regenerative strategies. Nevertheless, regenerative business practices are not widely appropriated in practice. Purpose: The purpose of the paper is to explore the phenomenon of regenerative businesses on SME level through the perspective of Swedish sustainability consultants. The authors aim to gain an understanding of the transformation processes in order to investigate if SMEs can reach a regenerative stage and, if so, how? Method: The study was conducted with an inductive qualitative approach under the interpretivism paradigm, and a multiple case study approach was chosen to best capture the phenomenon. The primary data was collected through semi-structured interviews with sustainability consultants from various SMEs in Sweden, and a thematic data analysis was conducted to interpret the empirical findings to relate them to the theories presented. Conclusion: The findings pointed to eight factors that enable and restrict SMEs in transitioning to a regenerative phase. Internally, SMEs are impacted in their transition by the mindset, values, sustainability awareness, strategy and communication, and the organizational structure of the business. In addition, the main external factors influencing the transition are the ambiguity regarding the sustainability concept and pressure from various stakeholders. The findings also highlighted the interconnectedness of the factors and the importance of a paradigm shift to whole systems thinking.

The research project studies the impact of urban regeneration in the historic centre of Naples during the 1990s. It examines how the centre-left administration, elected in 1993, harnessed the city's cultural and architectural heritage with the view to encouraging tourism, attracting inward investment and fostering among Neapolitans a sense of civic pride and a greater participation in urban life. It is argued that the reimaging of the built environment during the 1990s entailed re-definitions of citizenship, public space and urban history and the construction of a consensual vision about a 'new' Naples, but that this process was at the same time renegotiated and contested by residents and city users. The research focuses on three key urban sites - two piazzas and a park built after the 1980 earthquake - in order to analyse how the material and discursive consequences of regeneration led to conflicts over meanings and uses of public space. These case studies involved extensive periods of observation and interviews as well as consultation of newspapers and historical material. The study of Piazza Plebiscito, a former car park pedestrianized in 1994 and since officially adopted as the city's new symbol, examines disparate notions of heritage and urban decorum. Piazza Garibaldi, located in front of the main railway station and reconceived during the 1990s as the 'gateway' to the historic centre, analyses the relationship between immigrants and the piazza and the representation of such groups in debates about the regenerational city. Lastly, DAMM, an occupied centro sociale ('social centre') situated in an abandoned neighbourhood park, examines both the representation of the central popular quarters in debates about the city's renovation and the attempts by a group of local residents and young people to organize an alternative public space.

Critical writing on public art in the late 20th century in the UK and USA either legitimized public art as an extension of studio art intended to widen its public, or implied a new relation to public space - as demonstrated in texts by Cork (1995) and Phillips (1988) respectively. This suggests a polarization of art's aesthetic and social dimensions. A deeper understanding of the relation between these dimensions is found in the work of Marcuse, Bloch and Adorno. Marcuse, in his early work, sees art as serving the needs of bourgeois society by displacing ideas of a better world to an independent aesthetic realm; Bloch sees art as giving form to hope, shaping a recurrent aspiration for a better world; Adorno sees the tension between the aesthetic and social dimensions of art as unresolvable, and, like Marcuse in his later work, sees art's autonomy as a space of criticality. But, as Bloch argues, conditions for change are noncontemporaneous, fostering culture which is both progressive and regressive. In this respect, Gablik's appropriations of other cultures may be seen as regressive, whilst Lippard's concern for locality offers art a basis for progressive intervention. The introduction of the local, as a point of reference alongside the aesthetic and social, leads to consideration of three cases of art practice: Common Ground's Parish Maps (1986-96), the Visions of Utopia Festival coordinated by the Artists Agency (1996-8), and 90% Crude (1996--), a project by PLATFORM in London. The originality of the thesis is in its investigation of these cases; and equally in making connections between them and the elements of art criticism and critical theory noted above.

Craniosynostosis is the premature fusion of one or more cranial sutures in the developing skull. If left untreated, craniosynostosis can result in developmental delays, blindness, deafness, and other impairments resulting from an increase in the intracranial pressure. In many cases, the treatment consists of complex calvarial vault reconstruction with the hope of restoring a normal skull appearance and volume. Re-synostosis, the premature re-closure following surgery, occurs in up to 40% children who undergo surgery. If this occurs, a second surgery is needed to remove portions of the fused skull in an attempt to correct the deformities and/or relieve an increase in intracranial pressure. These subsequent surgeries are associated with an incredibly high incidence of life threatening complications. To address this unmet clinical need we have developed strategies to delay the post-operative bone growth in a clinically relevant murine model of re-synostosis. The overall objective of this thesis was to develop a hydrogel based therapy to delay rapid bone regeneration in a murine model of re-synostosis. The overall hypothesis was that delivery of key BMP inhibitors involved in regulating normal suture development and regeneration will delay the rapid bone growth that in seen in a pediatric murine model of re-synostosis. The overall approach is to use micro-computed tomography (µCT) to determine the time course of suture fusion and to identify genes associated with key developmental time points, to develop a pediatric specific mouse model that displays rapid re-synostosis, and lastly to develop a hydrogel based therapy to delay the re-synostosis of this cranial defect.

Les lasers excimeres pompes par decharge sont de puissantes sources impulsionnelles de lumiere ultraviolette capables de delivrer des puissances moyennes de quelques kilowatts a des taux de repetition superieurs au khz. Leur utilisation dans le cadre d'une chaine amplificatrice permet de generer des impulsions courtes et de forte energie appropriees pour certaines applications. L'objectif du concepteur d'une chaine xecl est d'adapter les parametres de l'amplificateur aux proprietes optiques requises pour l'application. On connait les conditions electriques optimales de decharge pour les lasers xecl (ne/xe/hcl). D'autre part, la relation entre le gain petit signal g 0, l'intensite de saturation i s et l'intensite optique du laser est bien connue. Mais il manque un chainon raccordant les conditions de pompage aux caracteristiques amplificatrices du plasma. Dans le chapitre 1, on etablit les relations entre la densite de puissance electrique w i n de la decharge et l'intensite optique du laser puis entre w i n et g 0 d'une part et i s d'autre part. En conclusion, on propose un algorithme permettant de definir tout d'abord les valeurs des parametres g o et i s puis electriques adaptes a toute application. Cela constitue un precieux outils qui permet, dans tous les cas, de reduire notablement l'etude parametrique experimentale. Dans le chapitre 2, une chaine xecl est developpee grace a l'algorithme propose. Cette chaine originale et tres simple delivre un train d'impulsions nanosecondes a partir d'une impulsion unique et affiche un taux d'extraction superieur a 60%. Dans le chapitre 3, une chaine xecl de puissance est developpee permettant de realiser des experiences de generation d'extreme uv a 13,9 nm avec trois durees d'impulsion differentes (1,9 ns, 40 ns et 150 ns). Le rendement de conversion pour differentes cibles metalliques a ete mesure. On a aussi compare la duree d'emission euv a celle du laser.

A major environmental concern throughout the tropics is deforestation. While many forests are in a state of crisis, such an encompassing narrative can obscure significant instances where forest-cover expands. This research investigates the geography of forest regeneration in rural Costa Rica from a social and institutional perspective. Attracted to the Pacific coast, foreigners purchase farms, change the patterns of land ownership, and extensively promote secondary forest growth. Environmental change and a declining agriculture sector have forced peasants to sell or abandon land and diversify their livelihoods. Two conservation NGOs collaborate at an institutional level to promote reforestation and consolidate protected properties into the Mesoamerican Biological Corridor. Drawing on foreign funding, they serve as an avenue through which external visions of land management become reproduced locally. This case illustrates how the values and management decisions of a constellation of actors synergistically interlink to influence local land-use and ultimately join to expand forest-cover.

The outcomes of sustainable neighbourhood regeneration (NR) practice, delivered by a range of NR organisations, have offered a lifeline of support in many disadvantaged communities. However, since dramatic ‘policy shift’ following the financial crisis and installation of the Conservative Liberal-Democrat Coalition Government in 2010, sustainable NR practice has faced a radically changing and far more challenging landscape under ‘austerity’, threatening NR organisations’ ability to deliver such practice, in a context where inequalities continue to deepen. This Critical Overview Document (the ‘thesis’) draws together a coherent body of inter-related research, published between 2009 and 2013, to identify and conceptualise organisational factors considered critical to sustainable NR practice in the English context, and how these have changed following dramatic policy shift. First, using existing literature and empirical research findings from a set of case study NR organisations, the thesis identifies and conceptualises these organisational factors, framing them within an ‘NR Factor Menu’. The empirical research is then drawn upon to characterise the process of dramatic policy shift and its impact on sustainable NR practice, manifest in how case study NR organisations are changing their operational activities. The thesis subsequently conceptualises these changes, representing them in a ‘post-policy shift’ NR Factor Menu. Representing a contribution to knowledge in this arena, this conceptualisation is then used to develop a better understanding of the broader role and nature of sustainable NR practice under ‘austerity’ and beyond, identifying the potential impacts of this for other NR organisations and communities. The conceptual explanation essentially identifies that dramatic policy shift has resulted in a ‘narrowing’ of those organisational factors critical to sustainable NR practice, brought about by a necessary focus on income generation and entrepreneurial activity. This has taken place through the development of new organisational factors – the ‘income generation engine’ and ‘organisational dynamism’. Such processes appear to have weakened community ownership of the NR process and, more broadly, reduced the importance of community advocacy and social mission in sustainable NR practice. This improved understanding informs policy and practice suggestions for other NR organisation strategies and further research.

Public art has long been seen as a phenomenon with little intimate connection to its surroundings, whether it is as a discursive formation surrounding a work or an abstract object encountered by passers-by as a relatively passive aesthetic experience. This thesis seeks to demonstrate how public artworks, rather than having sites formed around them by discourse, or sitting still within physical locations, actually create their own multi-layered sites through a process of enrolment and implication of a wide network of factors; physical, spatial, temporal, political and more. Taking inspiration from the works of Bruno Latour and John Law, this research seeks to investigate the specifically created sites of environmentally autonomous artistic interventions by recasting the limited Actor-Network Theory as a practical research methodology especially suited to determining some of the nature of this 'active' public art and its role in ongoing processes of urban regeneration. In doing so, the research draws particularly on contemporary archaeology, and its close links with anthropology and material culture studies, in using the contemporary environment, a flattened time in which past, present and future are actively constituted, to develop a contextual approach to researching public art that, in particular, takes close account of multiple temporalities and the simultaneity of different networks' enrolment and implication. Tightly focussed on one public art scheme in one place, Cabot Circus, Bristol, this research seeks to make use of a multi-disciplinary micro-study to draw wider conclusions about the nature of developers' and local governments' engagements with public art, while also outlining the potential for archaeologists to engage with urban regeneration in a new way that uses public art as the catalyst for a deeper engagement with, and understanding of, ongoing change and its relationship to daily life in the contemporary city.

Electric fields, which are generated by the movement of charged ions across membranes, are found in all biological systems and can influence cellular components ranging from amino acids to biological macromolecules. Physiological field strengths range from 1 – 200 mV/mm, and these electric fields are especially elevated at sites of cellular growth during development and regeneration. It has previously been demonstrated that elevated electric fields induce alignment of astrocyte processes in vitro, enhancing the rate of neurite outgrowth. It is believed that electric fields of varying physiological strength affect other astrocytic responses associated with regeneration. To characterize the duration over which these changes emerge, cultured rat astrocytes were exposed to different direct-current electric field strengths. The resulting cellular behaviors were recorded every three minutes with an inverted microscope equipped with DIC optics and a stage incubator. Electric fields were found to induce astrocyte responses similar to those observed during periods of neurodevelopment and regeneration. Changes in astrocyte movement, proliferation, & morphology emerged within the first hour and persisted through the course of the electric field application, leading mammalian astrocytes to revert to an earlier maturation state resembling those seen in amphibian astrocytes associated with central nervous system regeneration. Collectively, these results suggest that applied electric fields lead to astrocyte dedifferentiation, with certain electric field strengths eliciting and enhancing specific cell responses.

This thesis concentrates on the consequences of strong commitment⁄ Engagement in contemporary work. The aim of the thesis is to Build knowledge on regeneration and development of human resources. The empirical research consists of three case studies mainly Based on interviews: two are explorative studies on four strongly Committed champions within two projects of radical reorganisation. The third Empirical study is exploring one strongly engaged champion within an extensive Business rationalisation. The two first case studies were originally set for Other research and are therefore analyzed secondarily here. The case studies indicate that the strong commitment that is needed in contemporary Work is problematic when crises arise. The commitment and energy Tend to reduce quickly in bad managed crises. In order to break an evil Circle of energy loss the manager’s support is central, and also the possibility to Learn from experiences in an acceptable climate.
Avhandlingen fokuserar på det starka engagemangets konsekvenser i Det samtida arbetet. Syftet är att bidra med förståelse kring engagemangets Betydelse för regenerativ utveckling av mänskliga resurser. Avhandlingen baseras på studier av fem förändringsledare och deras Tre utvecklingsprojekt. Den främsta metoden för insamling av Information var intervjuer, men även andra metoder såsom deltagande observationer Har använts. Av de fem starkt engagerade förändringsledarna som Studerats var det fyra som misslyckades att nå sina projektmål, endast en lyckades Och gick stärkt ur projektet. Två av projekten var radikala, det vill säga de Sökte bryta med befintliga värderingar och organisera arbetet efter en annan Människosyn. Studien visar på att starkt engagemang som ju ofta behövs i ett samtida Gränslöst arbete också kan vara problematiskt när krissituationer uppstår. Individens Engagemang och energi tenderar att förbrukas, istället för att återskapas Vid en illa behandlad kris. För att kunna bryta en ond cirkel av energiförbrukning Föreslås chefers stöd vara en viktig komponent, men också möjligheten Att lära från sina erfarenheter i ett tillåtande klimat.
QC 20100902

Plans currently exist to extend the range of native woodland within the Scottish Highlands. The effects of such an expansion on birds, mammals and above ground invertebrates have been previously been investigated, but little consideration has been given to soil invertebrates. This research looks at effects of Scots pine (Pinus sylvestris) regeneration on the meso- and macro- soil invertebrate communities. Within the Abernethy Forest Reserve (the largest remaining tract of native Scots pine woodland within the UK) mature woodland (pine-dominated) and moorland (Calluna vulgaris-dominated) sites were chosen on the three soil types present; an iron podzol, humus-iron podzol and peat. Three intermediate regeneration sites, upon two of the soil types, were also selected based on tree density and diameter at breast height (dbh). Together these sites formed two transects representing succession from moorland to mature woodland on the two soil types. At each site soil invertebrates were collected to a depth of 0.1 in and pitfall traps set. Litter bags were placed at the woodland and moorland sites to examine invertebrate succession during Pinus and Calluna litter decomposition. All invertebrates were identified to order and oribatid mites identified further using the morphospecies technique. The influences of soil type, depth, season and tree age on invertebrate communities were analysed using TWINSPAN and CANOCO. Results suggested that differences were present in invertebrate abundance and community structure between the two soil types, with more variation occurring along the peat transect than podzol transect. A number of oribatid morphospecies showed differences in density between transect sites and indicator species were present which separated the younger regenerating sites form older woodland. CANOCO analysis demonstrated that this was primarily due to changes in soil pH and temperature. In litter bags, Calluna showed significantly greater colonisation compared with Pinus at all sites and woodland litter bags supported a greater diversity of invertebrates than comparable moorland bags. Calluna litter is more complex than Pinus and may therefore provide a greater number of niches for invertebrates and shelter from prey. Differences between sites may be due to the presence of species adapted to utilising both litter types at the woodland end of the transect. In general concentrations of N and P significantly influenced the community composition within litter bags (pc0.05), but there were no significant relationships with other macronutrients. This work has shown that there are differences in the invertebrate community composition during the regeneration of Scots pine and decomposition of litter, however it is currently unclear whether these changes are truly successional.

The airway epithelium demonstates the ability to quickly repair following physical injury. The morphologic features of this dynamic repair process have been well characterised at the anatomic and cellular level using a number of animal model systems and these studies have provided a solid foundation upon which our understanding of normal repair is build. With the advent of molecular and bioinformatic tools and resources the opportunity exists to extend the value of these models in defining the molecular pathways and interactions that underlay the normal repair process. This thesis represents a realisation of this opportunity. A large animal model was developed in which selected areas of airway epithelium were subjected to bronchial brush biopsy as part of routine bronchoscopic examination prcedures in anaethetised sheep. The process resulted in a physical perturbation of the normal pseudostratified structure of the sheep airwway epithelium at specific locations. By careful experimental design it was possible, within the same animals. to identify and sample from sites undergoing repair at different intervals subsequent in injury. To supplement the histological evaluation of the repair process and align findings with extablished small animal models of airway epithelial repair proliferative cell labelling strategies were implemented in order to study the location and extent of cellular proliferation occurring duringthe repair process. Molecular approaches towards defining the transcriptional response to physical injury comprised application of microarray technology using a commercially sources array platform. Such approach demanted preliminary effort directed towards optimising RNA integrity and yield from airway samples. Following preliminary studies directed towards optimising the model conditions patterns of airway epithelial repair following bronchial brush biopsy were studies in eight sheep at degined time points (6 hours, 1,3, & 7 days) post-injury. Bronchial brush biopsy resulted in the acute removal of the epithelial cell layer and components of the underlying structures. repair processes were rapidly implemented through initial epithelial dedifferentiation, proliferatino and migration at the wound margins and subsequent time-depentend changes in the proportion of subepithelial structures, including smooth muscle and blood vessels, as the epithelial surface moved towards repair. Transcriptional analysis revewaled that over 13,000 probes showed evidence of differential expession at some point during the repair process (p<0.05), whilst of these, 1491 probes had in excess of a two-fold change in expression. array results were validated against conventional semi-quantitative RT-PCR for selected genes. Differentially expressed genes with previously characterised roles in epithelial migration, prolifereation and differentiation were identified during the repair process. The relative emphasis of gene products with particular functional roles varied during the course of repair. Indeed gene ontology (GO) terms identified included those associated with the inflammatory response, cellular migration, extracellular matrix activities, differentiation, proliferation, cellular development, cell cycle activities, cellular adhesion, apoptosis and mitosis. In addition the Kyoto Encyclopedia of Genes and Gneomes (KEGG) databases were queried and such process indicated the involvement of cell communication, 053 and complement and coagulation cascade pathways throughout the repair process, initial (6h) Toll-like receptor and cytokine-cytoine receptor interaction pathways, and the progressive involement of cell cycle, focal adhesion and extracellulaar matrix (ECM)-receptor, and cytokine interaction pathways as the epithelium repaired. The model of airway epithelial injury developed in this thesis generated features broadly consistent with those previosly described in relation to various small animal model systems. Importantly, and in addition, this thesis defines the molecular features associated with repair in this model system and provides a useful resource with which to assess the comparative fetures of the airway transcriptional response to physical injury, It is through such comparison, using analogous methodology, that the fundamental pathways and interactions that underlay normal repair and regeneration can be identified and therafter extended towards inderstanding the basis for variation associated with natural and experimental disease.

Spatial coupling of plant recruitment processes was measured during 1996 in a dynamic post-agricultural successional environment on the Port Hills of Banks Peninsula. Steps along a conceptual vegetation→seed rain→seedlings recruitment continuum were measured, and the degree of spatial coupling (as measured by correlations of DCA ordination axis position) between each determined. Spatial coupling of recruitment processes provides a direct measure of potential vegetation change; tight coupling indicates vegetation is changing little as each recruitment step is spatially similar to the step previous, whereas weak coupling indicates dynamic change as steps are not spatially related. Coupling was weakest at the vegetation→seed rain and seed rain→seedlings stages, indicating that at these stages plant dispersal and vegetation change are most strongly expressed. Coupling was strongest at the vegetation→seedling stage, indicating that processes associated with seedling establishment and survival offer the strongest impediments to vegetation change. Coupling of all steps was weakest at the habitat-type level, with spatial patterns related to presumed successional age, indicating that vegetation change is proceeding in a process of within-valley succession and species migration. This result confirms those of previous studies which have investigated vegetation change on the Port Hills and Banks Peninsula. It indicates that with the removal of proximate causes of disturbance (fire, grazing, agriculture, etc.) the overwhelming trend of vegetation change in post-agricultural successional environments such as this is toward forest dominated by native species.

This master thesis is intended as a contribution to the understanding of the influencestructural changes has on urban transformation in housing domain, by focusing onmechanisms behind the upgrading as accidental model for regeneration of the collectivehousing. In particular, the aim is to do so in relation to a comparison between differentoperational scales on which process is carried out. The process is investigated at the city,neighborhood and street/square scale. With the use of qualitative methods, such asinterviews, in depth analysis of policies and regulations and observations, differences inmanifestation of the regeneration on different scales are discovered. It is suggested thatundefined strategy, indifferent attitude of local authorities, inconsistent legislativeenvironment, disconnection between the operational scales and presence of the market asessential driving force of the process, results in asymmetric outcomes of upgrading, both inphysical and social terms. But on the other hand, in respect to wider political and economicalenvironment in which regeneration happened, it is acknowledged that considerable housingstock is renovated and living standards are improved. The most critical issue in the process isproved to be the uneven awareness of the importance of the regeneration among the actorsat different scales and consequently their performance in respect to it. Furthermore,influence of upgrading on the community life and social relation in the regeneratedneighborhoods are totally neglected, which has for its consequences decreased use ofcommon space between the buildings and erosion of existed communities. It is proved alsothat fully market driven regeneration has rather regressive consequences on urbantransformation in context of Nis but in same time gives valuable lessons for improvement ofthe future upgrading as regeneration model for collective housing. Based on these lessons,adaptive policy changes are suggested and platform for further studies in system or processoriented urban regeneration and design is established. Thesis is organized as follows: firstmethodological approach is explained, second it situate problem in wider regional and localcontext in respect to urban transformation and housing trends, third thesis discuss analysisof operational scales and conclude with final cross-scale discussion and potentials for furtherresearch.

The widespread threat of species extinctions caused by the destruction and degradation of tropical primary forest (PF) could potentially be mitigated by the expansion of regenerating secondary forest (SF). However, the conservation value of SF remains controversial, and is dependent on many site- and landscape-scale factors, such as habitat age and isolation. The aim of this thesis was to assess the role that SF can play in conserving forest bird communities in central Panama. We study a chronosequence of SF aged 20 – 120-years-old, with sites either isolated from or connected to extensive PF. Our results suggest that SF supports high levels of avian species diversity, and similar community composition to PF. Whilst forest age plays a small role in determining compositional similarity to PF, connectivity to extensive PF was the main determinant of community composition. However, despite high species richness and complex community composition, some specialist PF bird species were consistently absent from SF, and isolated PF. The functional diversity of bird communities did not vary substantially across the forest age and isolation gradient, although we did find some inter-guild differences; with distinct responses in communities of avian insectivores and frugivores. Isolation caused shifts in the trophic traits of insectivores, but resulted in alterations in the dispersal traits of frugivores. The response of bird and tree community composition to forest age and isolation was similar, although isolation had a stronger impact on bird communities. Bird diversity and composition tracked changes in forest structure over succession. When examining the role of birds in seed-dispersal networks, we found bird gape width was the key predictor of seed size consumed. Large-gaped birds consume a wider variety of seed-sizes than small-gaped birds, and small-seeded trees attract a greater number of bird species than large-seeded trees. These results imply high levels of redundancy among small-gaped avian frugivores and small-seeded plant species, but low levels of redundancy among large-seeded plant species and their avian dispersers. This suggests that large-seeded plants may be most at risk of dispersal failure following any change in avian frugivore assemblages. Together, these results suggest that SF can play a key role in sustaining most tropical biodiversity, and in maintaining ecosystem services. Our findings emphasise the importance of integrating SF into conservation strategies to support and buffer tropical PF habitats.

Altitudinal treeline advance represents a sensitive and well-studied example of species response to climate warming. Although a great deal of work has been conducted globally, few studies have considered subtropical alpine treelines and little is known about their structure and function. This research aims to investigate the response of high altitude forests in Taiwan to climate variation by characterising treeline advance in the area, exploring the mechanisms driving the advance, and considering the consequences of advance for the wider community. The thesis consists of a general introduction to the topic followed by a series of papers, exploring: (1) Possible consequences of treeline shifts for biodiversity and ecosystem function. (2) The advance of the Abies kawakamii treeline through aerial photograph analysis. (3) The changes in growth rate of Abies kawakamii at treeline and the influence of altitude and temperature on growth. (4) Regeneration patterns at treeline and the importance of microclimate and topographic sheltering. (5) Consequences of the range shift for the wider forest community. The work is then concluded with a general discussion and synthesis. The main aims of this work are therefore to characterise and understand the pattern and pace of treeline advance and forest structural change throughout the Central Mountain Range of Taiwan. Treeline advance is characterised through the study of repeat aerial photographs and the mechanisms behind the observed shift are explored through the study of two key responses associated with forest advance: tree growth at treeline and seedling establishment beyond treeline. The consequences of treeline advance for the wider subalpine community are investigated through the study of epiphytic lichen communities at treeline sites. This investigation of an understudied region will allow for improved understanding of treeline response at a global scale.

Ecological restoration that aims to reinstate indigenous processes may be constrained by regional and local conditions, especially those that drive dispersal and colonisation. Local conditions can be managed, while regional conditions cannot. The management of costly rehabilitation programmes is considered best practice when scientifically informed. My thesis documents the responses of biological communities to a range of local conditions developing in coastal dune habitats in response to ecological restoration. Here, landscape-level (spatial structure of patches of tree canopies) local conditions were distinguished from site-level (topography, soil nutrient content, woody plant community richness, microclimatic variables) local conditions. The spatial structure of tree canopies varied over time and differed between the mining lease site and the relatively undisturbed benchmark site prior to (1937- 1970), and after (1990-2006) mining. For example, approximately 20% of the mining lease site and 40% of the benchmark site was covered by tree canopies prior to mining. However, after mining and rehabilitation, the structure of tree canopies began to converge towards that of the benchmark. The topographic profile of coastal dunes was less heterogeneous after mining and rehabilitation than before. Aspect, elevation and gradient of dune slopes were also different and had shifted in space. Variability in the structure of tree canopies could not explain variability in species richness, forest-associated species richness and proportion of benchmark species for the millipede, dung beetle and bird communities ashad been expected. However, species composition did change (though idiosyncratically) with age-related changes in soil nutrient availability and tree species diversity. Temperature, relative humidity and light intensity varied with dune topography, but soil nutrient content (C: N ratio and pH) was better accounted for by the age of the regenerating forest than by dune topography. Similarly, analysis of covariance suggested that tree canopy density, woody plant richness and millipede species richness only responded to the aspect, elevation and gradient of restored coastal dunes when age was taken into account as a covariate. However, the response of keeled millipedes to dune topography, regardless of regeneration age, suggested that the microclimatic variability brought about by topographic heterogeneity may provide these specialists with suitable microhabitats. Throughout my thesis, the age of regenerating patches of indigenous canopies was often more important as an explanatory variable than habitat conditions per se. Age itself is not a determinant of biological communities, but merely the axis along which habitat conditions change with succession, and later, patch dynamics. Therefore, as elsewhere, my thesis has highlighted age as a useful proxy for the response of biological communities to local conditions. It seems that managing local variables such as those considered in my assessment is not an avenue through which to enhance restoration. After kick-starting initial conditions, best practice rehabilitation management should therefore focus on minimizing external disturbances rather than interfering with natural processes.
Thesis (PhD)--University of Pretoria, 2013.
Zoology and Entomology
unrestricted

As communities and managers become aware of the long-term impacts of mangrove loss, estimated at 1-2% per year, interest in sediment erosion and mangrove rehabilitation has increased substantially. In this thesis project I 1) examine erosion rates within coastal fringing Rhizophora mangle ecosystems following mangrove clearing and compare these rates to accretion rates in intact mangroves; and 2) investigate the abiotic factors influencing mangrove seedling survival and regeneration of naturally colonizing R. mangle, in historic mangrove habitat after anthropogenic clearing. Differences in erosion were compared between patches of open-coast intact and anthropogenically cleared R. mangle to quantify the sediment trapping function provided by mangroves and its loss following clearing over a 24 month period. Growth rates of mangrove seedlings in intact forest were compared to seedlings in cleared areas. Seedling growth indicators were measured on 100 seedlings at five sites (50 in the intact and 50 in the cleared areas). To examine the limiting factors on seedling growth rates, nutrient addition and wave protection treatments were applied to seedlings in three disturbed areas. Sites within intact mangroves had sediment accretion (M= +3.83 mm) while areas cleared of mangroves had sediment erosion (M= -7.30 mm). Seedling growth (height) over the 2 year study period significantly differed between intact mangrove (M = 15.6 cm) and cleared (M = 10.24 cm) areas. Seedling mortality from the cleared areas (31%) differed from the intact areas (13%). Average seedling growth (height) was: greater with both nutrient/wave (M = 18.4 cm) and nutrient (M = 17.65 cm) treatments compared to controls (M = 10.8 cm), which suggests that providing nutrients and/or wave protection result in growth outputs comparable to seedlings found in intact mangroves. This study may prove to be useful in identifying areas that are most vulnerable to erosion following mangrove removal and ideal location of restoration following mangrove removal. Areas cleared of mangroves can lead to intensified erosion in areas where fringing reefs are not continuous. When managers are determining areas to focus resources for restoration, focusing on areas with nutrient rich habitat may result in higher survival rates and growth outputs.

京都大学
新制・課程博士
博士(人間健康科学)
甲第23426号
人健博第93号
新制||人健||6(附属図書館)
京都大学大学院医学研究科人間健康科学系専攻
(主査)教授 山田 重人, 教授 林 悠, 教授 森本 尚樹
学位規則第4条第1項該当
Doctor of Human Health Sciences
Kyoto University
DFAM

The development of human societies rests on functioning ecosystems. This thesis builds on integrated theories of linked social-ecological systems and complex adaptive systems to increase the understanding of how to strengthen the capacity of ecosystems to generate services that sustain human well-being. In this work, I analyze such capacity in human-dominated production ecosystems in Tanzania and Madagascar, and how this capacity is related to local management practices. Resilience of social-ecological systems refers to the capacity to buffer change, to re-organize following disruption, and for adaptation and learning. In Papers I and II, qualitative interview methods are used for mapping and analyses of management practices in the agroecosystem of the Mbulu highlands, Northern Tanzania. Practices such as soil and water conservation, maintenance of habitats for pollinators and predators of pests, intercropping, and landscape diversification, act to buffer food production in a variable environment and sustain underlying ecological processes. The practices are embedded in a decentralized but nested system of institutions, such as communal land rights and social networks, that can buffer for localized disturbances such as temporary droughts. Paper II compares these findings with practices in a farming system in Sweden, and suggests that similar mechanisms for dealing with uncertainty and change can exist in spite of different biophysical conditions. In Papers III and IV, interviews are combined with GIS tools and vegetation sampling to study characteristics and dynamics of the dry forests of Androy, southern Madagascar. Paper III reports on a previously underestimated capacity of the dry forest of southern Madagascar to regenerate, showing areas of regeneration roughly equal areas of degenerated forest (18 700 ha). The pattern of forest regeneration, degradation, and stable cover during the period 1986-2000 was related to the enforcement of customary property rights (Paper III). Paper IV reports on a network of locally protected forest patches in Androy that is embedded in a landscape managed for agricultural or livestock production and contributes to the generation of ecosystem services and ecosystem resilience at a landscape scale. Forest protection is secured by local taboos that provide a well-functioning and legitimate sanctioning system related to religious beliefs. In Paper V, two spatial modeling tools are used to assess the generation of two services, crop pollination and seed dispersal, by the protected forest patches in southern Androy. The functioning of these services is dependent on the spatial configuration of protected patches in the fragmented landscape and can be highly vulnerable to even small changes in landscape forest cover. In conclusion, many of the identified practices are found to make ecological sense in the context of complex systems and contribute to the resilience of social-ecological systems. The thesis illustrates that the capacity of human-dominated production ecosystems to sustain a flow of desired ecosystem services is strongly associated with local management practices and the governance system that they are embedded in, and that, contrary to what is often assumed, local management can and does add resilience for desired ecosystem services. These findings have substantial policy implications, as insufficient recognition of the dynamics of social-ecological interactions is likely to lead to failure of schemes for human development and biodiversity conservation.

To be creative or innovative is a highly praised trait within the labor market of today. Though it has often been seen as a talent only granted to a chosen few, most evidence imply that it is something that we all possess and can develop. Creativity within education also appears to have positive impacts on school-results, attendance and confidence among students. Yet creativity has a low status within the current education system, making the opportunities to develop our creative ability insufficient.  Architectural projects and development strategies focused around creativity have occurred frequently on the agenda since the release of Richard Floridas book “The Rise of the Creative Class” in 2002. An increase of creative activity has been linked to growth but lately also to gentrification, as if this was an inevitable result. The focus has been on economic growth and increased tourism, instead of what creativity can bring to the individual and the community.  This thesis aims to answer two main questions: First, how can creative places benefit the schools and communities in socio-economically challenged areas? Second, how can these creative places best be designed to achieve these benefits? Creative places refer in this thesis to public spaces that encourages creativity, which can be places for creative production but also places for experiencing creative works of others. The aim is also to implement the learnings into a design proposal, where the area Vivalla in Örebro is chosen as the site for implementation. In order to answer the first question, the paper examines the existing conditions of vulnerable areas in Sweden and some of the available research on creativity in relation to education. To gain knowledge about design aspects four existing projects that aims to be places for creativity are analyzed. The local conditions of Vivalla are mainly researched through qualitative methods of observation, interviews and a workshop with students from the local school. Finally, the ideas and findings are implemented into a design-proposal, which is a vision for a new creative platform. Rather than a finished project, the proposal should be seen as a vision showing the potentials of the site that can be used as a basis for discussion with the local actors, This paper provides some useful arguments to why creative places in socio-economically challenged areas are worth investing in and highlights the importance of an inclusive development process. Finally, it also provides a diverse view of one of Sweden’s most segregated areas.

L’inquiétude au sujet du devenir des forêts tempérées de moyenne montagne va croissant, du fait du changement climatique d’une part, et des difficultés de régénération liées à la pression exercée par les grands ongulés d’autre part. Les populations d’ongulés herbivores connaissent en effet une forte augmentation depuis le milieu du XXème siècle dans l’hémisphère Nord ; et leur abroutissement sélectif, dû à leurs préférences alimentaires, exerce une forte pression sur la régénération, dont l’intensité sur les essences varie selon leur appétence. La réponse de la régénération au changement climatique en termes de survie et de croissance demeure méconnue, mais de premiers résultats suggèrent qu’elle pourrait être encore plus affectée que les arbres adultes, et de manière différentielle également du fait des diverses autécologies des essences. Dans ce contexte de changements globaux, le recours aux forêts mélangées est envisagé comme une option valable de minimisation des risques. Comment caractériser la réponse de la régénération à ces deux pressions de sélection, et quel pourrait être l’avenir d’un peuplement mélangé dans ce contexte ? Notre étude se focalise sur les effets de l’abroutissement par les grands ongulés et du changement climatique sur la régénération du sapin, du hêtre et de l’épicéa en mélange. Nous utilisons pour cela diverses approches. Nous montrons que la germination et l’installation de semis de hêtres n’est pas affectée par l’éclairement au sol plus faible en situation de mélange. Nous mettons en évidence une quasi-inversion d’essences entre sapin et épicéa au niveau de la strate de régénération, bénéficiant à l’épicéa, lorsqu’ils sont soumis à une forte pression d’abroutissement. A l’échelle des traits foliaires, nous trouvons des réponses différentes entre les trois essences aux pressions du climat et de l’abroutissement, le sapin étant le seul à exprimer une réponse claire à l’abroutissement (tissus plus résistants, augmentation du rapport C/N foliaire). Nos résultats démontrent également une diminution de l’abroutissement avec l’augmentation de la température hivernale et un effet plus important de l’abroutissement que de la température printanière sur la croissance des semis de sapin, hêtre, érable. Enfin, via une approche de modélisation, nous avons simulé la dynamique d’un peuplement mélangé de sapin, hêtre et épicéa sur une durée de 100 ans, et montré une modification des seuils de tolérance à la sécheresse par l’abroutissement, et vaildé la possible disparition du sapin dans des scénarios comprenant abroutissement et changement climatique. Ces travaux soulignent l’influence des grands ongulés en interaction avec les conditions climatiques sur la dynamique de la régénération forestière, et l’importance de prendre cette pression en compte dans les protocoles de recherche destinés à étudier l’évolution de la régénération en contexte climatique changeant
There is growing concern about the future of temperate mountainous forests, because of climate change and of the difficulties in regenerating forests caused by large ungulates pressure. Herbivore ungulate populations have strongly increased since the middle of the XXth century in the northern hemisphere. By their selective browsing due to their dietary preferences, they exert a strong pressure on regeneration, which intensity on each tree species varies with their palatability. The response of regeneration to climate change in terms of growth and survival is still poorly known, but some results suggest it could be affected differentially given the different autecologies of the species. In such a global changes context, mixed forests are considered a valuable option of adaptation. How would the regeneration phase respond to those two pressures, and what could be the future of a mixed stand in such a context? This study focuses on the effects of browsing by large ungulates and climate change on mixed silver fir, Norway spruce and beech stand regeneration. We show that the lower amount of light reaching the ground in mixed stands does not affect beech regeneration germinating. We demonstrate a quasi-substitution of silver fir by Norway spruce saplings when submitted to high browsing pressure. At the finer scale of foliar traits, we find different responses among the three species to varying climate and browsing pressure, silver fir being the only species expressing an answer to browsing (increase in shoot mechanical resistance and in foliar C:N). Our results also demonstrate a decrease in browsing with increasing winter temperature, and a stronger effect of browsing than of spring temperature on saplings growth for silver fir, beech and sycamore maple. Finally, our simulations of the dynamics of a mixed silver fir-Norway spruce-beech stand suggest a shift in tolerance to drought thresholds due to browsing, and confirm the possible eradication of silver fir in scenarios combining browsing and climate change. This work highlights the influence of large ungulates interacting with climate conditions on forest regeneration dynamics, and the importance to consider this pressure in research protocols aiming at studying the behaviour of regeneration in changing climate contexts

Thesis (PhD)--Stellenbosch University, 2000.
ENGLISH ABSTRACT: Diabetes Mellitus (DM) is synonymous with "B-cell failure". Ligation of the pancreatic duct distally to its confluence into the bile duct has been shown to induce endocrine tissue regeneration from a number of probable sources. The cells responsible for regeneration are supposed to possess either dormant pluripotent stem cell ability and/or the plasticity to undergo metaplasia to form new and surplus endocrine tissue able to replace pathologically and/or experimentally compromised pancreas. The sequence of events (cell lineage) during this process of neogenesis, has been the source of controversy for quite some time as various studies suggest that the cell lineage differs from in vivo and in vitro studies, according to experimental model and species of laboratory animal. The object of this study was to utilise an established experimental laboratory animal model to study islet morphological changes, neogenesis and or both in vivo. Further aims of the study were to determine the extent, sequence and magnitude of pancreatic duct ligation (PDL) induced endocrine neogenesis/morphogenesis in a laboratory rat model using occlusive pancreatic duct ligation. PDL's were performed on six groups of 25 normal adult Sprague-Dawley (SD) rats (300g+) according to the method of Hultquist and Jonsson (1965). Experimental animals were sacrificed at 12 hr intervals from day one post-PDL to day 10 and every 24 hrs thereafter to day 14 as described by Wang, Klëppel, Bouwens (1995). Animals received BrdU (a thymidine marker and cell proliferation indicator) 50mglkg intraperitoneally as described by Wang et al. (1995), one hour prior to removal of the pancreas after which it was fixed in Bouin's solution and histologically processed. Seven consecutive 3-6 urn thick serial sections were sequentially stained with H & E, insulin (I), glucagon (G), somatostatin (ST), pancreatic polypeptide (PP), neuropeptide tyrosine (NPY) and peptide tyrosine tyrosine (PYY). Immunolabeling was done according to the method of Guesdon, Temynck , Avrameas (1979). Double immunolabeling for BrdU and each pancreatic peptide was performed on the sections on days 3,5, 7, 9 and 11 as described by Wang et al (1994). Cellular transformation between one and 3Yz days was characterised by simultaneous total deletion and/or transdifferentiation of the acinar compartment and the appearance of immunoreactive cells for I (11.53 ±1.5%), G (1.85 ±0.8%), pp (1.50 ±0.09%), and ST (1.96 ±0.24%). Changes in the endocrine composition in existing islets, occurred along a pathway that saw PP- and ST-cells invading the islet core, islet mantle glucagon deletion and random appearance of all endocrine cell types within the inter-islet interstitium on day 3Yz. Days 4 to 6Yz saw further endocrine expansion while days 7 to 14 were distinguished by islet reconstitution and consolidation. NPY immunoreactivity appeared on day 4Y2 and persisted intermittently throughout while PVV first appeared on day 4 and disappeared after day 7Yz. The results suggest that PDL firstly induced the development of endocrine tissue distributed haphazardly throughout the space previously occupied by acinar parenchyma. Secondly, the appearance of insulin is preceded by the appearance of PP, glucagon and somatostatin by 24-hours. A still to be determined proportion of the ligation induced endocrine formation appeared to be associated with existing islets, resulting in a number of very large islets, some of which might have secretory access through the glomerularlike capillary network known to occupy the islet core. The remainder appeared to form separate "new" islets, which have a dubious access to the blood stream. In conclusion, if it is true that the pancreas can regenerate some of its endocrine tissue then it has potential clinical implication for the stabilising of diabetes mellitus. Ligated exocrine pancreatic tissue, devoid of its acinar component, has been shown to contain notable quantities of insulin positive cells. This presents intriguing possibilities as an alternative for donor tissue, usually obtained from rat foetuses, during foetal rat pancreas transplantation studies. Pancreas tissue harvested from duct ligated rats could replace the foetal tissue currently used in the treatment of experimental diabetes mellitus in laboratory animals in this laboratory.
AFRIKAANSE OPSOMMING: Diabetes Mellitus is sinoniem met B-sel disfunksie. Endokriene regenerasie kan segmenteel bewerkstellig word deur eksperimentele afbinding van die pankreasbuis distaal tot sy samesmelting met die gemene galbuis. 'n Verskeidenheid van selle word vermoedelik by hierdie proses betrek. Dormante stamselle besit die vermoë en/of plastisiteit om 'n aantal vorms van metaplasie te ondergaan om nuwe en/of oortollige endokriene weefsel te vorm wat patologiese en/of eksperimenteel gekompromiseerde weefsel vervang. Die selontwikkelings volgorde wat tydens hierdie proses plaasvind is al vir 'n geruime tyd die middelpunt van 'n meningsverskil. Sommige studies dui daarop dat die in vivo selontwikkelingsvolgorde verskil van in vitro, volgens eksperimentele model en tipe proefdier gebruik. Die doel van die studie was die gebruik van 'n bestaande eksperimentele laboratorium proefdier model om pankreas eiland morfologiese verandering en/ofneogenese of beide in vivo te evalueer. Die oogmerk van die studie was om die omvang en volgorde van veranderings in die endokriene kompartement (neogenese/morfogenese) te bepaal deur gebruik te maak van 'n pankreas buis afbindings (PBA) model wat totale afsnyding van die buis tot gevolg het. PBA's is uitgevoer op ses groepe van 25 volwasse normale Sprague-Dawley (SD) laboratorium rotte (±300g) soos beskryf deur Hultquist en Jonsson (1965). Proefdiere is elke 12 uur geoffer vanaf dag een post-PBA tot dag tien en elke 24 uur daarna tot dag 14 soos beskryf deur Wang, Bouwens, Kloppel (1995) na die toediening van 50 mg/kg 5-Bromo-2-deoksi-uridien intraperitoneaal ('n selprolifererings aanduider) soos beskryf deur Wang et al. (1995). Die pankreas is werwyder, in Bouin se oplossing gefikseer en histologies geprosesseer. Sewe openvolgende seriesnitte (3-6 urn) is alternatiewelik gekleur met H & E, en immunositochemies, soos beskryf deur Guesdon, Terugnek, Avrameas (1979), vir insulien (I), glukagon (G), somatostatien (ST), pankreatiesepolipeptied (PP), neuropeptied tirosien (NPY) en peptied tirosien-tirosien (PYY). BrdU dubbel-immuunkleuring is ingesluit op dae 3,5, 7, 9 en 11 soos beskryf deur Wang et al. (1994). Sellulêre transformasie tussen dae een en 3~ dae is gekenmerk deur gelyktydige en totale uitwissing en/ofmetaplasie van die asinêre kompartement en die verskyning van selle immunorektiefvir I(11.53 ±1.5%), G (1.85 ±0.8%), PP (1.50 ±0.09%), ST (1.96 ±0.24%). Metaplasie was verantwoordelik vir merkbare veranderings in bestaande endokriene weefsel langs In transformasie weg waar eiland insulien kemselle vervang is deur PP- en ST-selle, glukagon buitelaag uitwissing en die toevallige verskyning van alle endokriene seltipes in the inter-eiland interstitium teen dag 3Y2. Dae 4Y2deur 6~ is gekenmerk deur verdere endokrinetoename terwyl dag 7 deur 14 gekenmerk is deur eiland hersamestelling en konsolidering. NPY immunoreaktiwiteit was vanaf dag 4~, met afwisseling, te bespeur terwyl PVV slegs tussen dae 4 en 7 In verskyning gemaak het. . Die resultate suggereer eerstens, PBA induseer die ontwikkeling van oortollige endokriene weefsel op In lukrake wyse versprei deur die ruimte voorheen deur asinêre parenchiem beset. Tweedens, dat die verskyning van insulien deur dié van PP, glukagon en somatostatien met minstens 24-uur voorafgegaan is. Die verhouding, van nuutgevormde endokriene weefsel wat met bestaande eilande assosieer om In aantal baie groot eilande te vorm, moet nog vasgestel word. Sulke strukture mag moontlik afskeidings toegang hê tot die bloedstroom, deur die glomerulusagtige kapillêre netwerk, in die eilandkern teenwoordig terwyl die oorblywende nuutgevormde endokrine weefsel "nuwe" apparte eilande vorm wat wel of gladnie toegang tot die bloedstroom mag hê nie. As gevolgtrekking, indien dit waar is dat volwasse pankreas eilandweefsel wel regenerasie kan ondergaan, dan het dit kliniese implikasie vir die stabilisering van diabetes mellitus. Weefsel verkry uit PBA bevat geen asinêre weefsel nie maar wel merkbare hoeveelhede endokriene weefsel, veral insulin positief. Dit bied dan interessante alternatiewe as skenker weefsel by fetal rot pankreas oorplantings. PBA en/of die oorplanting van pankreasbuis afgebinde weefsel, na in vitro weefsel kultuur, bied moontlikhede vir die behandeling van diabetes mellitus.

Comprendre comment les variations du climat pourraient influencer le recrutement des arbres en forêt est un défi car la germination, la croissance et la survie des semis sont particulièrement sensibles aux facteurs biotiques et abiotiques. Plusieurs modèles conceptuels généraux, (la " stress gradient hypothesis " SGH et " latitudinal herbivory theory " LHT,) suggèrent que la nature et l'intensité des interactions biotiques varient le long de gradients environnementaux. Ces modèles constituent une base théorique utile pour déterminer le rôle des interactions biotiques dans la réponse des communautés végétales aux variations du climat. Cependant, les études portant sur la SGH se sont limitées aux interactions directes entre plantes et ont négligé les interactions complexes. Les théories développées pour des niveaux trophiques supérieurs (comme la LHT) sont quant-à elles sujettes à débat et ne considèrent qu'un nombre limité d'interactions. Les interactions avec les micro-organismes du sol ont par exemple été négligées. Dans cette thèse, j'ai analysé comment les interactions directes et indirectes entre les semis, les arbres adultes, la végétation herbacée, les insectes herbivores et les pathogènes du sol varient en nature et en intensité le long de gradients climatiques. Pour explorer les interactions entre plantes, j'ai effectué une expérimentation s'appuyant sur la variabilité spatio-temporelle des conditions climatiques dans les Alpes. Les résultats montrent que les effets directs de compétition de la canopée et de la végétation herbacée augmentent avec la température. Cependant, pour les sites les plus chauds, la facilitation indirecte pourrait limiter la compétition directe des herbacées. Pour les interactions avec insectes herbivores,nous avons montré que le long de gradients d'altitude et de latitude, l'herbivorie est minimale là où les stress thermiques et hydriques est fort. Enfin, pour les interactions avec les micro-organismes du sol, nous avons mesuré en chambre de culture la survie de plantules de hêtre dans des sols, stérilisés ou non, collectés le long d'un gradient d'altitude. Les résultats montrent que les effets négatifs des micro-organismes sont plus faibles quand les communautés microbiennes proviennent de sols d'altitudes. Cette thèse suggère que les effets directs négatifs des plantes, des insectes herbivores et des pathogènes du sol sur les semis dominent dans les environnements chauds et productifs et s'atténuent dans des conditions plus froides. Les interactions indirectes semblent varier inversement et pourraient ainsi tamponner l'effet des interactions directes.

Der demografische Wandel und die damit verbundene Stadtschrumpfung führen in vielen sächsischen Städten zu städtebaulichen Missständen. Als Reaktion darauf formulieren die Städte mit dem Stadtumbau Ost Ziele zur Wiederherstellung nachhaltiger Siedlungsstrukturen. Das Handeln der Gemeinden wird dabei durch überörtliche Institutionen des Stadtumbau-Programms beeinflusst. Ziel der Arbeit ist die Ermittlung des Zusammenhangs zwischen den gemeindlichen siedlungspolitischen Zielen und den überörtlichen Vorgaben im sächsischen Stadtumbau. Als Erklärungszusammenhang für den oben beschriebenen situativen und institutionellen Kontext wird der akteurzentrierte Institutionalismus herangezogen. Ziele sind eines der vier Elemente der Stadtplanung. Es bestehen sowohl Gründe für eindeutige als auch für vage Ziele. Die vertikalen Zielbeziehungen vom Zweck bis zum Handlungsziel ergeben eine Zielhierarchie, die sich in den überörtlichen Vorgaben im Stadtumbau-Programm als hybride Zielhierarchie wiederfindet. Für den Anwendungsfall der siedlungspolitischen Ziele, die sich aus flächen- und gebäudepolitischen Aussagen zusammensetzen, wird ein Kategorienschema entwickelt, mit dem die Stadtumbaukonzepte untersucht werden können. Der empirische Teil der Arbeit basiert auf einer inhaltsanalytischen Themenanalyse von 24 Stadtumbaukonzepten im Direktionsbezirk Chemnitz. Dabei wird grundsätzlich die Programmorientierung der Gemeinden nachgewiesen. Allerdings formulieren sie eindeutige, vielfach aber auch vage Handlungsziele. Ein Vorrang der gebäude- gegenüber den flächenpolitischen Zielen ist nicht festzustellen. Im Ergebnis ist im sächsischen Stadtumbau weder ein Vorrang der Eindeutigkeit noch der Vagheit festzustellen. Die sächsischen Gemeinden im Stadtumbau Ost orientieren sich bei der Zielformulierung zwar an den überörtlichen Vorgaben. Zugleich orientieren sie sich aber an den Risiken des demografischen Wandels und der Stadtschrumpfung. Daher wird das Postulat der Ziel- und Risikoorientierung formuliert. Auf dieser Basis werden Handlungsempfehlungen für die überörtlichen raumpolitischen Ebenen gegeben, um das Programm Stadtumbau Ost hinsichtlich der siedlungspolitischen Ziele zu optimieren. Diese Empfehlungen beziehen sich auf die Stadtumbau-Paragrafen, das Förderprogramm sowie die Arbeitshilfe und sonstigen Formen der Betreuung der Gemeinden.

En s’inscrivant dans le champ de la sociologie urbaine, ce travail de thèse s’interroge sur les conditions d’émergence du changement social dans l’espace urbain. Comment passe-t-on d’un état sociétal à un autre ? L’espace urbain étant à la fois un cadre matériel et un cadre social en interaction, ce travail tente de montrer que l’action urbaine, en définissant un ensemble de démarches qui exercent un contrôle sur la physionomie des espaces, et en tentant de corriger leurs déséquilibres et leurs dysfonctionnements, est l’instrument de la mise en place d’un nouvel ordre social sur un territoire. En s’appuyant sur l’exemple d’une action urbaine, le renouvellement urbain, ce travail se propose d’en faire une lecture sociologique en observant et en analysant ce qu’il préconise pour changer le cadre spatial pour ensuite rendre compte de ses effets sur la réalité sociale. L’intérêt de la recherche est d’observer un processus, au moment même où il se développe, en mettant en exergue ses conditions d’apparition sur un territoire. La réflexion porte sur la manière dont l’espace conçu et pensé rencontre l’espace vécu et pratiqué
This thesis, set in the field of urban sociology, explores the conditions favoring a modification of the social order in the urban space. How do new structures impose themselves thus transforming the social reality into a new one ? The urban space having at the same time a material and a social content interacting with each other. This work intends to demonstrate that urban action is an instrument which creates a new social order, because this process implies a control on the aspect of spaces by trying to correct their potential imbalances and defects. Following the example of a urban regeneration, this work sociologically observes and analyses the propositions made to change the urban space and the effects it has on the social reality. The interest of this research is to observe a process at the same time it is being developed. The aim of the study is to show how the space that has been conceived and thought beforehand meets the space where one lives

This thesis contributes to the growing EU-US literature by comparing and explaining the evolution of urban policy in these two federal systems. The thesis begins with a puzzle: after introducing two similar and equally short-lived regeneration schemes—Model Cities (MC) (1967) and URBAN (1994)—the US and the EU followed different paths: the former replaced MC with the durable Community Development Block Grant (CDBG) in 1974, while the latter ended urban policy by ‘mainstreaming’ URBAN in its regional policy in 2006. To solve the puzzle I formulate a two-part argument: first, I explain the similarities between MC and URBAN as resulting from three factors: a favourable political context, holistic urban policy ideas, and centre-periphery mistrust. I then explain subsequent trajectories by looking at the interplay of policy and politico-constitutional institutions. While both MC and URBAN were unable to ‘stick’ because of their inherent weaknesses, the result of their demise depended on the existence of a federal ‘city welfare’ state. In the US, the Housing and Urban Development Department (HUD) embodied this state, and channelled Nixon’s attacks on MC into the creation of the structurally stronger CDBG. In the EU, conversely, DG Regio could not provide a comparable anchor for urban policy: when URBAN was attacked by regions and cities, the DG just reverted to its ‘business as usual’ by mainstreaming the programme. I test my argument with a macro-historical comparison of the two cases and four in-depth city studies—Arlington, VA and Baltimore, MD on the US side, and Bristol, UK and Pescara, Italy on the EU side—aimed at analysing micro-level institutional dynamics. In both parts of the study I use a wide range of sources: secondary and grey literature, statistical sources and, especially, archival material and elite interviews. At both levels of analysis the test confirms my argument.

Les territoires et les paysages littoraux sont soumis à des risques naturels de mieux en mieux identifiés et croissants (tempêtes, submersions…), notamment sous les effets du changement climatique, dont les manifestations, pas seulement eustatiques, auront d’autres conséquences sur les paysages. Comment, dans une logique proactive, tirer parti des modifications de paysages tout en limitant, contrôlant, voire corrigeant les dérives induites par la hausse du niveau marin sur les littoraux ? L’objectif est de montrer qu’il est possible de s’ajuster à ces risques par la prise en compte des paysages et par la pratique d’une gestion plus douce et raisonnée des aménagements côtiers. Après avoir établi un bilan argumenté sur la prise en compte du paysage dans les stratégies aujourd’hui mises en œuvre pour réduire les risques d’inondation et de submersion, la thèse évalue comment le projet de paysage, processus holistique de conception et de partage de visions à long terme, peut-il être un outil de réduction de la vulnérabilité du territoire et de sa société. Puis, la thèse se focalise sur la Camargue, territoire deltaïque emblématique dont les processus naturels et sociaux ont permis d’inventer une société et des paysages créateurs de richesses dans un équilibre dynamique face aux risques permanents d’inondation et de submersion. Cependant, avec, entre autres causes, celle du changement climatique, cet équilibre stratégique est remis en question et nécessite d’élaborer les hypothèses d’une autre Camargue. Ainsi, dans une dimension exploratoire, la thèse propose une illustration argumentée de nouveaux modèles de développement et d’ajustement du système camarguais. La double prise en compte du paysage et du changement climatique et les premiers résultats de l’étude de dépoldérisation des Bas-Champs Picards, nous amènent à revendiquer la mise en œuvre d’une politique de renouvellement littoral en tant que réponse aux problèmes des territoires côtiers d’aujourd’hui et plus encore de demain
Coastal territories and landscapes are submitted to increasing yet better identified natural risks (storms, flooding, etc.), especially under the effects of climate change. Its reflections, the eustatic ones among others, have various consequences on the landscape. How is it possible, in a proactive reasoning, to take advantage of the lanscape alterations at the same time as limitating, controling and why not correcting the excesses due to the sea level rise on the coasts ? The aim is to show that it is possible to adjust to these risks upon taking landscapes into account and managing the coastal structures a lighter and better thought-out way.An argued assessment on the way the landscape is taken into account in current strategies used to reduce the flooding risks, is followed with an evaluation of the way the landscape project, a holistic process of designing and sharing long term visions, can be used as a tool to reduce the vulnerability of both the territory and its society. Then, the thesis focuses on the emblematic Camargue delta, a territory which natural and social processes allowed to develop a society together with lanscapes creators of wealth in a dynamic balance considering the permanent flooding risks. However, keeping in mind, among other causes, that of climate change, this strategic balance is being questioned and needs the elaboration of hypotheses for another form of Camargue. Thus, in an exploratory dimension, the thesis suggests an argued illustration of new models of development and adjustment for the system of Camargue. Taking into account both the landscape and climate change, the first results of a study on managed realignment in Bas-Champs, Picardie, lead us to a demand for the implementation of a coastal regeneration policy as the answer to the issues of coastal terriories for today, and even more for tomorrow

The subject of this graduation thesis is a conceptual architectural study of the former house of correction extension, annex and reconstruction and also a new ideological solution of adjacent areas and total building plan . The house is located in the Brno’s Bronx district. The reconstruction is focused on the use of alternative housing concepts with the general target at the whole city quarter reneration – address change.

This research project is based upon the assumption that humanity is passing through a period of great transition, or “Great Turning,” in which we have a critical opportunity to pass from a destructive “industrial growth society” to a “life-sustaining society” (Macy and Brown, 1998). I argue that the current scale of social, political, environmental, economic, psychological, and spiritual challenges reflects an underlying “disconnect disorder” (Arabena, 2006), and that these combined external and internal crises present an opportunity for widespread transformative learning and a collective shift. My core hypothesis is that this transition depends on humanity’s ability to engage in a dual process of individual and collective transformation through remembering our connections with ourselves, with one another, with the natural world, and with a sense of purposeful engagement in the world. I investigate this hypothesis through an in-depth, relational study of the Ecology of Leadership program (EOL) at the Regenerative Design Institute (RDI) in Bolinas, California, an organization that aims to “serve as catalyst for a revolution in the way humans relate to the natural world.” The Ecology of Leadership represents a unique model of transformative adult education that incorporates the principles of “inner permaculture” and regenerative design to support participants in cultivating personal and collective transformation. I introduce a “relational” theory and methodological approach, which centralizes Indigenous and ecological principles of relationship, respect, reciprocity, and regeneration. Using interviews (p=20), surveys (p=409), arts-based data (p=12), sharing circles (p=8), and participatory research, I integrate personal and participant narratives together with images, graphics, poems, and practices to bring this case study of the Ecology of Leadership to life. I also advocate for a new model of “regenerative research,” in which the research itself is life-giving and contributes to the healing, transformation, and regeneration of the researcher, the community of research, and the whole system. Based upon my interactions, observations, and interviews in the EOL program and my reflections and supportive research, I conclude by articulating the “Ecology of Transformation,” a holistic model for transformation that incorporates inner and outer change with practices for reconnection to oneself, the natural world, and the village.

According to recent reports, increases in water acidification and changes in seawater salinity are predicted to occur in the next 100 years. The increase of atmospheric CO2 already caused a pH reduction in surface waters by more than 0.1 units below the pre-industrial average of 8.1, and it is expected to decrease between -0.13 and -0.43 units by the end of this century. Climate change can also occur through alterations in seawater salinity. Warmer temperatures and reduced rainfall increase seawater salinity, while extreme rainy events decrease seawater salinity. Both situations will promote species responses. Therefore, identifying the effects of predicted climate change in aquatic ecosystems must be a priority in order to maintain their biodiversity. Aside from climate change, there is an increasing concern about the large number of emerging pollutants that have been released into the environment without yet being regulated. Among these emerging pollutants are Engineered nanoparticles (ENPs). One of the types of ENPs that are most commonly used in recent years are Carbon Nanotubes (CNTs). Due to their unique chemical and nanotoxicological properties, it is expected that CNTs enter aquatic environments and accumulate in aquatic biota. As a matter of fact, CNTs toxicology in aquatic systems is complex. In the first instance particle size, shape, chemistry and capping agents will all play a role regarding the stability, and thus bioavailability. However, nanomaterial toxicity not only has been attributed to core structure and surface modification/functionalization, but also by the physico-chemical parameters of the media where the CNTs are presented, altering their dispersion and consequently their detection: aggregation/disaggregation, adsorption/desorption, sedimentation/resuspension and dissolution. Several works have described their impacts in the aquatic environment; however, no information is known on how predicted Climate Change could alter the CNT’s toxicity and their effects on marine organisms. Benthic species are a good model to evaluate the impacts of Climate Change and ENPs as they are sensitive to several environmental constrains. Essentially due to their life-history characteristics, as well as their relatively rapid response to pollution, several studies have been using benthic species as bioindicators for anthropogenic and natural stresses. Thus, the evaluation of the impacts of CNTs, under salinity changes and pH reduction on aquatic organisms is an urgent issue needing attention. Particularly, Ruditapes philippinarum (bivalve), Hediste diversicolor and Diopatra neapolitana (polychaetes) have been identified by several authors as a group of marine invertebrates that respond quickly to environmental disturbances, with a wide spatial distribution and economic relevance, namely in Portugal. Thus, the present proposal evaluated the toxic effects in terms of biochemical (energy reserves and metabolic activity, oxidative and neuro status) and physiological responses (regenerative capacity) in the cited species of salinity shifts and pH variation and the presence of CNTs acting along and in combinations. The two CNT materials selected in the present study were the pristine multi walled carbon nanotubes (Nf-MWCNTs) and the chemically functionalized MWCNTs, by introducing polar groups such as carboxyl groups (-COOH) increasing their stability and dispersibility in the water media. As a starting point we evaluated the possible effects of the carboxylation/functionalization of the surface of MWCNTs in organisms for each exposure concentration. In all invertebrate species it was possible to observe a dose-dependent increased of the toxicity, especially in terms of oxidative status, which is in line with the information provided by the literature. Moreover, comparing the toxic effects of both CNTs, in all invertebrate species major cellular damage was induced by carboxylated forms of MWCNTs in comparison to the pristine one. Subsequently we selected the two most deleterious concentrations of Nf-MWCNTs and f-MWCNTs, and we exposed the three invertebrate species to the combination of CNT materials with salinity shifts and pH variations assessing if both climate change factors altered the toxicity of both MWCNT materials as well as the sensitivity of all these species exposed to these contaminates. The present findings underlined that Nf-MWCNTs and f-MWCNTs under control salinity and low pH generated major toxic impacts in the organisms compared to individuals maintained under low salinity and control pH, confirming that salinity shifts and pH variations may alter the chemical behaviour of both MWCNTs and consequent fate in exposed individuals. Moreover, we observed species-dependent sensitivity to contaminants confirming that the higher susceptibility observed in some species would however be expected not only to depend on the characteristics of the compounds, but also on the physiology of that particular species. For a better environment protection, the Ecological Risk Assessment of the mentioned stressors must include ecologically relevant endpoints and exposure scenarios to drive accurate safety levels towards biodiversity conservation.
De acordo com publicações recentes, nos próximos 100 anos prevê-se um aumento na acidificação da água do mar e alterações na sua salinidade. Nas águas superficiais, o aumento do CO2 atmosférico já causou uma diminuição do pH em mais de 0,1 unidades comparando com 8,1, a média referente à época pré-industrial. Está previsto que até ao final deste século, esta redução do pH possa atingir valores na ordem das 0,13 e 0,43 unidades. As alterações climáticas podem também resultar em alterações na salinidade da água do mar. A salinidade é mais alta quando as temperaturas são mais altas e os períodos de chuva são reduzidos enquanto que, eventos de chuva intensa diminuem a salinidade da água do mar. Em qualquer dos cenários, estas alterações irão promover respostas por parte das espécies. Portanto, é imperativo identificar os efeitos das alterações climáticas nos ecossistemas aquáticos de modo a conservar a sua biodiversidade. Para além das alterações climáticas, há uma preocupação crescente com o grande número de poluentes emergentes que têm sido descartados no meio ambiente sem serem devidamente regulamentados. Entre estes poluentes emergentes estão as nanopartículas artificiais (Engineered nanoparticles - ENPs). Um dos tipos de ENPs mais usados nos últimos anos são os Nanotubos de Carbono (Carbon nanotubes - CNTs). Devido às suas propriedades químicas e nano-toxicológicas únicas, é expectável que os CNTs entrem nos ambientes aquáticos e se acumulem na fauna que lá vive. De facto, a toxicologia dos CNTs em sistemas aquáticos é complexa. Numa primeira análise, o tamanho, a forma, a estrutura química e os agentes de revestimento desempenharão um papel no que diz respeito à estabilidade e, portanto, à biodisponibilidade da partícula. No entanto, a toxicidade dos nano-materiais tem sido atribuída não só à sua estrutura central e modificação/funcionalização da sua superfície, mas também aos parâmetros físico-químicos do meio em que os nanotubos se apresentam e que podem alterar a sua dispersão e consequentemente a sua deteção: agregação/desagregação, adsorção/dessorção, sedimentação/ressuspensão e dissolução. O impacto dos nanotubos no meio aquático já foi descrito por vários autores; no entanto, ainda não se sabe de que forma as alterações climáticas podem alterar a toxicidade dos CNTs e subsequentemente os efeitos sobre os organismos marinhos. As espécies bentónicas são um bom modelo para avaliar os impactos das Alterações Climáticas e ENPs, uma vez que são sensíveis às mudanças ambientais. Principalmente devido às características do seu ciclo de vida, bem como à sua resposta relativamente rápida à poluição, há vários estudos que usam espécies bentónicas como bioindicadores para fatores de stress antropogénicos e naturais. Sendo assim, é urgente avaliar os impactos dos CNTs, sob alterações de salinidade e redução do pH em organismos aquáticos. Ruditapes philippinarum (bivalve), Hediste diversicolor e Diopatra neapolitana (poliquetas) são invertebrados marinhos que respondem rapidamente a perturbações ambientais e são caracterizados por uma ampla distribuição espacial e relevância económica, nomeadamente em Portugal. Pelo que, esta tese pretendeu avaliar os efeitos tóxicos de desvios de salinidade, variação de pH e presença de CNTs (atuando isolados ou em combinação) ao nível da resposta bioquímica (reservas de energia e atividade metabólica, estado oxidativo e neurotoxicidade) e da resposta fisiológica (capacidade regenerativa) das espécies acima citadas. Neste estudo, os dois materiais de CNT selecionados foram os nanotubos de carbono de parede múltipla, não funcionalizados (pristine multi walled carbon nanotubes - Nf-MWCNTs) e os MWCNTs quimicamente funcionalizados através da introdução de grupos polares como grupos carboxilo (-COOH), que aumentam sua estabilidade e capacidade de dispersão no meio aquoso. Como ponto de partida, para cada concentração de exposição, avaliamos os possíveis efeitos da carboxilação/funcionalização da superfície dos MWCNTs nos organismos. Em todas as espécies de invertebrados foi possível observar uma relação positiva entre o aumento da dose e a toxicidade, principalmente no que diz respeito ao estado oxidativo, o que está de acordo com a informação disponível na literatura. Além disso, comparando os efeitos tóxicos de ambos os CNTs, em todas as espécies de invertebrados, verificaram-se maior dano celular induzido pela forma carboxilada da MWCNT em comparação com a forma não funcionalizada. Posteriormente, selecionamos as duas concentrações de Nf-MWCNTs e f-MWCNTs mais perniciosas, e expusemos as três espécies de invertebrados à combinação destes materiais CNT com variações de salinidade e variações de pH, avaliando desta forma se estes fatores relacionados com as alterações climáticas modificavam a toxicidade de ambos os materiais MWCNT bem como a sensibilidade das espécies expostas a esses contaminantes. Os resultados obtidos salientam que Nf-MWCNTs e f-MWCNTs sob salinidade controlo e pH baixo, geraram grandes impactos tóxicos nos organismos em comparação com indivíduos mantidos em condições de salinidade baixa e pH controlo. Confirmou-se desta forma que, alterações de salinidade e variações de pH podem alterar o comportamento químico de ambos os MWCNTs e consequentemente o efeito em indivíduos expostos. Além disso, observamos que a sensibilidade ao contaminante é dependente da espécie o que confirma que a maior suscetibilidade observada em algumas espécies não é apenas um resultado das diferentes características dos compostos usados, mas também da fisiologia dessas espécies em particular. Para uma melhor proteção do meio ambiente, a Avaliação de Risco Ecológico dos fatores de stress mencionados, deve incluir objetivos e cenários de exposição ecologicamente relevantes para impulsionar medidas de segurança corretas e adaptadas com respeito à conservação da biodiversidade.
Programa Doutoral em Biologia e Ecologia das Alterações Globais

碩士
臺北醫學大學
生物醫學材料研究所
93
Reconstituted type I collagen matrix extracted from the rat tail tendon was utilized to regenerate the temporomandibular joint disc in the rabbit. The aim of this study was to examine extracellular matrix changes and mechanisms of regeneration in the temporomandibular joint disc. Thirty-two New Zealand rabbits underwent either sham surgical procedures or partial temporomandibular joint discectomy. In animals that underwent partial discectomy, the discs were replaced by reconstituted collagen templates. Some of the surgerized animals did not receive any implant. Tissue sections of the surgerized temporomandibular joint were obtained at 1-, 2-, and 3-month interval after surgery. Tissue morphology was evaluated either by gross and histology. Collagen changes of the disc were determined using immunohistochemistry. To confirm the structure and function of regenerative disc, this study compared the differences of regenerative and native disc. Additionally the changes of extracellular matrix and cell morphology were taken to understanding the mechanism of disc regeneration. Histology showed that the joint appeared more severe degeneration in the partially discectomized joint without implantation when time passed. After 3 months, the cartilage was fully destroyed and the bone was entirely exposed. In untreated joints, the condyle exhibited type I collagen in the fibrous regions and type II collagen in areas of proliferative cartilage. In contrast, discs that recievied reconstituted collagen template regenerated and the extracellular matrix of regenerative disc could return normal to protect joint. Cells in the regenerative tissue expressed extracellular matrix first, and then the tissue formed fibers randomly. Gradually, fibers became regular and compact by tissue remodeling and collagen expression increased. The reparative cells differentiated into chondroblasts, and the peri-cellular fibers showed a heavy density. Cell morphology appeared smaller compared to the early stage of repair. Finally, the morphology, extracellular matrix composition and the collagen expression of the disc and condyle was similar to that of normal tissue. In conclusion, the reconstituted collagen template effectively facilitated a regeneration for the surgically discectomized discs. The regeneration of articular discs had correlate closely with extracellular matrix, especially type I and type II collagen.

The impact of a bark beetle outbreak, and the following sanitation management actions, on the mountain spruce forest in the central part of the Šumava Mountains were compared after twelve years of development. The survey was focused on natural regeneration of trees and herb-layer vegetation.

Tese de mestrado. Biologia (Biologia da Conservação). Universidade de Lisboa, Faculdade de Ciências, 2010
As regiões montanhosas representam importantes áreas para a conservação da biodiversidade, sendo igualmente vitais para grande parte da população humana, que depende dos bens e serviços prestados pelos ecossistemas de montanha (MA 2005, Schuler et al. 2004). Na Europa, as regiões montanhosas evoluiram durante milénios sob intervenção humana, com a agricultura e a pastorícia a desempenharem um papel fundamental na definição dos ecosistemas de montanha (Blondel 2006, Mitchley et al. 2006). Nas últimas décadas, muitas destas regiões têm sofrido importantes transformações nas suas paisagens, como consequência do êxodo rural das populações e do consequente abandono das actividades agro-pastoris tradicionais (Rey- Benayas et al. 2007). Na freguesia de Castro Laboreiro, situada na região do Minho (NW de Portugal – Figura 1) o abandono agrícola teve ínicio na década de 50, despoletado por diversas forças motrizes de natureza socioeconómica (Lima 1996). Em 1929 foi lançada no país a Campanha do Trigo, que beneficiava sobretudo as regiões do Sul. Segundo Graça (1996), a região Sul recebeu entre 1935 e 1959, cerca de 84% dos fundos para a lavoura nacional, o que contribuiu para a marginalização das áreas agrícolas do Norte. Com a abertura das portas para a emigração, que se encontravam fechadas desde a II Guerra Mundial, iniciou-se o êxodo da população (Barreto 2002). Como parte integrante do Parque Nacional da Peneda-Gerês, a freguesia de Castro Laboreiro representa um lugar de particular interesse para a conservação da natureza. A sua paisagem apresenta uma enorme diversidade de habitats, onde se destacam as manchas de carvalhal galaico-português (Quercus robur e Quercus pyrenaica), das mais emblemáticas e melhor conservadas do país (2006a). A rotina pastoral dos habitantes da vila organizava-se em torno de um sistema único de alternância de residência, entre as localmente designadas brandas e inverneiras (Geraldes 1996, Lima 1996). Durante a Primavera, Verão e Outono as populações permaneciam nas povoações serranas mais elevadas, no planalto (brandas) regressando ao vale (inverneiras) para o Inverno (Geraldes 1996). Actualmente, a maioria das inverneiras da área de estudo encontra-se abandonada. A forma como a paisagem evolui em resposta ao abandono depende de muitos factores, mas principalmente das características da área abandonada (tipo e intensidade da acção anterior ao abandono), das condições para a ocorrência da sucessão ecológica e dos respectivos padrões de regeneração da vegetação, dos regimes de perturbação dominantes na área e das escalas temporais e espaciais consideradas (Farina 2007, McDonald et al. 2000). Uma das implicações mais comum do abandono agrícola é a modificação do mosaico da paisagem, devido à substituição das áreas abandonadas por áreas de matos e floresta, o que em Castro Laboreiro representa uma oportunidade para a regeneração e expansão da floresta de carvalhal, de elevado valor para a conservação da biodiversidade. No presente trabalho analisamos as alterações da paisagem de Castro Laboreiro entre 1960 e 2007 com especial foco nas alterações ocorridas nas áreas agrícolas e nas áreas de carvalhal. Incidimos a nossa abordagem em três questões principais: (i) está a expansão das florestas de carvalhal a ocorrer na área? Se sim, a que taxa?; (ii) que factores ambientais estão a actuar no processo de regeneração da floresta? e (iii) que factores ambientais influenciam o abandono dos campos? A evolução da paisagem foi analisada através da interpretação de fotografias aéreas e de ortofotos da área de estudo, registadas nos anos de 1960, 1990 e 2007. Utilizou-se a técnica de actualização regressiva para a interpretação das imagens, e as cartas de ocupação do uso do solo para os anos de 1990 e 2000 (IGEO 1990 e PNPG 2000a) para auxiliar a foto-interpretação. Foram definidas 8 categorias de uso do solo (área agrícola, carvalhal, pinhal, matos baixos, matos altos, rocha, água e aldeia – Tabela 1) e foram produzidos 3 temas vectoriais, um para cada ano analisado. Para medir as taxas e a direcção das alterações ocorridas – questão (i) - derivámos 3 matrizes de transição, uma para cada intervalo de tempo (1960-1990, 1990-2007 e 1960-2007) e construímos um diagrama de trajectórias (1960-1990-2007), através da intersecção dos temas vectoriais. As análises foram efectuadas em ArcMap 9.3 (ESRI). Aplicaram-se várias métricas para a análise da estrutura da paisagem, usando o programa Fragstats v.3.3(McGarigal et al. 2002). Para responder às questões (ii) e (iii) realizámos uma série de regressões logísticas, usando como variável resposta a ocorrência ou não de transição e como variáveis predictivas os atributos ambientais da paisagem. Realizámos dois tipos de análise: (A) focando a regeneração de carvalhal, em que a transição pode ocorrer de campos agrícolas, matos baixos ou matos altos para carvalhal; (B) focando o abandono dos campos agrícolas, em que a transição ocorre dos campos em uso para campos abandonados. Como atributos ambientais da paisagem seleccionámos as seguintes variáveis: altitude (ELE), declive (SLO), orientação (ASP), distância à àgua (dWAT), distância à fonte de sementes de carvalhal mais próxima (dOAK), distância à estrada mais próxima (dROAD), distância à aldeia mais próxima (dVILL), e fogo (FIRE). As análises foram efectuadas à escala da paisagem e à escala das brandas e inverneiras (ver detalhes na Tabela 2). A selecção dos modelos mais parsimoniosos foi baseada no critério do AIC mais reduzido e a área sob a curva ROC foi seleccionada como medida de desempenho dos modelos. As análises foram efectuadas no programa R (R Development Core Team 2010). A paisagem de Castro Laboreiro tem sido dominada por matos baixos e rocha, que em conjunto representam cerca de 65% da área analisada. Os resultados sugerem importantes transformações na paisagem entre 1960 e 2007, sendo a alteração mais significativa a redução das áreas agrícolas, que registaram um declinio de 52% face à àrea ocupada em 1960. Os matos altos aumentaram em 68% a sua representação na paisagem. Já as áreas de floresta de carvalhal registaram um aumento muito modesto (cerca de 4%)(ver Tabela 3 e Figura 2). O primeiro intervalo do estudo, (1960-1990) foi caracterizado por uma diminuição substancial da área agrícola (Anexo Ia), e o segundo período (1990-2007) foi marcado pela expansão de matos altos (Anexo Ib) e por uma tendência para a estabilização da paisagem (ver diagonal da matriz Anexo Ib). O abandono das áreas agrícolas entre 1960 e 2007, ocorreu em simultâneo com o declínio populacional na freguesia (Figura 3) e as áreas abandonadas foram naturalmente substituídas por áreas de matos altos (dominados por giestas - Cytisus sp.)(Figura 4). As giestas eram usadas para alimentar e forrar as camas do gado e para a produção de estrume. O estrume era aplicado nos campos, o que poderá ter criado um banco de sementes, promovendo a conversão directa dos campos abandonados para giestal (Eastbrook 1994). As métricas de paisagem aplicadas mostram uma tendência para a homogenização da paisagem, onde a distribuição espacial dos campos agrícolas exibe uma tendência para a fragmentação e para a simplicação da forma dos patches (Tabela 4), e as áreas de carvalhal uma tendência para a agregação dos patches e para a complexificação das suas formas (Tabela 4). Na análise da regeneração da floresta, um dos padrões mais óbvios detectados foi a relação negativa com a distância à fonte de sementes de carvalhal mais próxima (dOAK). Esta foi uma variável estatísticamente siginificativa em todas as análises de regeneração da floresta (quer à escala da paisagem, quer à escala das brandas e inverneiras), indicando que quanto menor for a distância à fonte de sementes, maior é a probabilidade de regeneração da floresta (Tabela 5). O mesmo padrão foi encontrado nos estudos de Gellrich et al. (2007) e Tasser et al. (2007). As variáveis topográficas orientação e declive também demonstraram um efeito sigificativo na regeneração da floresta. Na transição de campos agrícolas abandonados para carvalhal, a relação positiva encontrada com o declive aponta para um abandono preferencial dos campos agrícolas localizados em terrenos declivosos (Tabela 5). Quanto ao efeito do fogo, este apenas mostrou ser significativo na transição de matos baixos para carvalhal, indicando uma maior probabilidade de regeneração das áreas não ardidas (Tabela 6). Em relação ao abandono dos campos, os resultados apontam para um efeito positivo da altitude, do declive e da distância à aldeia na probabilidade de abandono (Tabela 7). Assim, os campos agrícolas localizados a altitudes mais elevadas, com declives mais acentuados e mais distantes das aldeias têm maior probabilidade de serem abandonados. Estes resultados estão de acordo com os obtidos por Sluiter e M. de Jong (2007) na localidade de Peyne, França. A análise à escala das brandas e inverneiras permitiu detectar padrões que não são visiveis à escala da paisagem. Contrariamente ao que seria de esperar, os resultados mostram que proporcionalmente houve mais abandono agrícola nas brandas do que nas inverneiras, o que indica que apesar de abandonadas, alguns campos ainda são mantidos nas inverneiras. A menor altitude e as características do solo nas inverneiras permitem o cultivo de culturas diferentes (árvores de fruto e hortas) daquelas que são cultivadas no planalto (centeio e batata)(Geraldes 1996). A expansão da floresta em Castro Laboreiro foi muito modesta (+4%) quando comparada com outros estudos europeus em áreas de montanha (e.g. Roura-Pascual et al. (2005) identificaram um aumento de 19% na área de floresta no Maciço-Este dos Pirinéus Espanhóis e Conti e Faragazzi (2004) um aumento de 17% no Alpes Italianos). Uma das explicações prendese com o erro associado à interpretação e classificação das imagens, onde cerca de 35% das áreas intepretadas como matos altos correpondem a carvalhal, levando a uma possível subestimação da área total de carvalhal. Tendo em conta a tendência populacional de Castro Laboreiro nos últimos 50 anos, é razoável assumir que o abandono irá continuar, bem como a regeneração das áreas de matos e floresta. O aumento das áreas de matos, conduz ao aumento do risco de incêndios, representando um desafio para a adopção de medidas de gestão adequadas.
Many European mountain areas are facing important changes in their landscapes due to farmland abandonment. This process favors the natural progress of ecological succession, therefore representing an opportunity for forest regeneration. In Portugal, farmland abandonment in mountain areas started around 1950’s and has continued ever since. In this study we aimed to assess the landscape changes in Castro Laboreiro parish (Northwestern Portugal) between 1960 and 2007, searching for patterns in oak regeneration and in abandonment of fields. We performed landscape interpretation using aerial-photographs and orthophotos taken in 1960, 1990 and 2007. We built transition matrices and a trajectory diagram to assess rates and directions of change, and we use logistic regression to search for relations between both oak regeneration and abandonment of fields and the environmental attributes of the landscape. Results show a tendency for landscape homogenization, indicating a reduction of open areas associated with agricultural fields. Farming area declined by 52%, with fields located at higher elevations, in steeper slopes and far from villages, being more likely to become abandoned. Former fields were mainly replaced by tall shrublands. Oak forests increased by 4% their area in the landscape, and models suggest that distance to the nearest oak source was the main environmental attribute explaining oak regeneration. We conclude that Castro Laboreiro parish underwent two important processes: the reduction in agricultural areas as a consequence of farmland abandonment, followed by the replacement of former fields with shrublands and forest.