1 |
Drivers and Hindrances to Med-Tech Innovation : A device's guide to the Swedish healthcare galaxyWagrell, Sofia January 2017 (has links)
Today, the expectations on new medical technology solutions are substantial. On the one hand, healthcare policy expects new technologies both to improve the quality of people’s life and to reduce the burgeoning healthcare costs. On the other hand, innovation policy expects new med-tech solutions to stimulate economic growth, with large emphasis on the production of new solutions. However, despite the growing importance of med-tech innovations it is cumbersome to embed these innovative promising products into use in the Swedish healthcare sector. This thesis investigates med-tech innovation by following a microwave-based device in the treatment of the common disease BPH, Benign Prostatic Enlargement. This is an empirically based longitudinal study where the microwave device is used as a probe to capture a med-tech innovation journey. We follow the device through the efforts of technological and scientific development, through complex industrial production structures and foremost inits struggles to achieve widespread use in Swedish public healthcare. This study identifies a number of hindrances and drivers and, importantly, how they are interconnected in the innovation process. By applying the different settings of development, production and use of this device, a central finding is that the very same mechanisms can have contradicting effects in the different settings. Moreover, what functions as a trigger to innovation during development, can become later a hindrance to use. The study also shows that, whereas drivers prevail over hindrances in the development and production of med-tech solutions, hindrances clearly prevail in their use, which involves the provision of healthcare services. Not only has the use setting a generally weak financial support, but its organisational structures and regulations do also have a negative impact on the spread of new solutions in healthcare.
|
2 |
Sharing, Superposition and Epansion : Geometrical Studies on the semantics and Implementation of lambda-calculi and proof-nets / Partage, superposition et développement : Etudes géométriques sur la sémantique et l'implémentation de lambda-calculs et de réseaux de preuvesSolieri, Marco 30 November 2016 (has links)
Des sémantiques élégantes et des implémentations efficaces des langages de programmation fonctionnels peuvent être décrits par les mêmes structures mathématiques, notamment dans la correspondance Curry-Howard, où le programmes, les types et l’exécution, coïncident aux preuves, formules et normalisation. Une telle flexibilité est aiguisé par l’approche déconstructive et géométrique de la logique linéaire (LL) et les réseaux de preuve, et de la réduction optimale et les graphes de partage (SG).En adaptent la géométrie de l’interaction de Girard, cette thèse propose une géométrie de l’interaction des ressources (GoRI), une sémantique dynamique et dénotationnelle, qui décrit algébriquement par leurs chemins, les termes du calcul des ressources (RC), une variation linéaire et non-déterministe du lambda calcul (LC). Les séries infinis dans RC sont aussi le domaine du développement de Taylor-Ehrhard-Regnier, une linéarisation du LC. La thèse explique la relation entre ce dernier et la réduction démontrant qu’ils commutent, et présente une version développé de la formule d’exécution pour calculer les chemins du LC typé.Les SG sont un modèle d’implémentation du LC, dont les pas sont locales et asynchrones, et le partage implique et les termes et les contextes. Bien que les tests ont montré des accélérations exceptionnelles, jusqu à exponentielles, par rapport aux implémentations traditionnelles, les SG n’ont pas que des avantages. La thèse montre que, dans le cas restreint des réseaux élémentaires, où seule le cœur des SG est requis, les désavantages sont au plus quadratique, donc inoffensifs. / Elegant semantics and efficient implementations of functional programming languages can both be described by the very same mathematical structures, most prominently with in the Curry-Howard correspondence, where programs, types and execution respectively coincide with proofs, formulæ and normalisation. Such a flexibility is sharpened by the deconstructive and geometrical approach pioneered by linear logic (LL) and proof-nets, and by Lévy-optimal reduction and sharing graphs (SG).Adapting Girard’s geometry of interaction, this thesis introduces the geometry of resource interaction (GoRI), a dynamic and denotational semantics, which describes, algebra-ically by their paths, terms of the resource calculus (RC), a linear and non-deterministic variation of the ordinary lambda calculus. Infinite series of RC-terms are also the domain of the Taylor-Ehrhard-Regnier expansion, a linearisation of LC. The thesis explains the relation between the former and the reduction by proving that they commute, and provides an expanded version of the execution formula to compute paths for the typed LC. SG are an abstract implementation of LC and proof-nets whose steps are local and asynchronous, and sharing involves both terms and contexts. Whilst experimental tests on SG show outstanding speedups, up to exponential, with respect to traditional implementations, sharing comes at price. The thesis proves that, in the restricted case of elementary proof-nets, where only the core of SG is needed, such a price is at most quadratic, hence harmless. / Semantiche eleganti ed implementazioni efficienti di linguaggi di programmazione funzionale possono entrambe essere descritte dalle stesse strutture matematiche, più notevolmente nella corrispondenza Curry-Howard, dove i programmi, i tipi e l’esecuzione coincidono, nell’ordine, con le dimostrazioni, le formule e la normalizzazione. Tale flsesibilità è acuita dall’approccio decostruttivo e geometrico della logica lineare (LL) e le reti di dimostrazione, e della riduzione ottimale e i grafi di condivisione (SG).Adattando la geometria dell’interazione di Girard, questa tesi introduce la geometria dell’interazione delle risorse (GoRI), una semantica dinamica e denotazionale che descrive, algebricamente tramite i loro per-corsi, i termini del calcolo delle risorse (RC), una variante lineare e non-deterministica del lambda calcolo ordinario. Le serie infinite di termini del RC sono inoltre il dominio dell’espansione di Taylor-Ehrhard-Regnier, una linearizzazione del LC. La tesi spiega la relazione tra quest’ultima e la riduzione dimostrando che esse commutano, e fornisce una versione espansa della for-mula di esecuzione per calcolare i percorsi del LC tipato. I SG sono un modello d’implementazione del LC, i cui passi sono loc-ali e asincroni, e la cui condivisione riguarda sia termini che contesti. Sebbene le prove sperimentali sui SG mostrino accellerazioni eccezionali, persino esponenziali, rispetto alle implementazioni tradizionali, la condivisione ha un costo. La tesi dimostra che, nel caso ristretto delle reti elementari, dove è necessario solo il cuore dei SG, tale costo è al più quad-ratico, e quindi innocuo.
|
3 |
Biodiversity from the bottom up: causes and consequences of resource species diversity.Narwani, Anita 24 August 2011 (has links)
Species diversity may simultaneously be a cause and a consequence of variability in population, community and ecosystem properties. Ecology has traditionally focused on elucidating the causes of biodiversity. However, in the last decade and a half ecologists have asked the opposite question: What are the consequences of species diversity? The majority of these studies elucidated the effects of species diversity within single trophic levels. Incorporating trophic complexity is the next step in this research program. In this dissertation I investigated the causes of resource species diversity, as well as the impacts that resource diversity has on rates of consumption and the stability of population, community and ecosystem properties over time in planktonic food webs.
The high diversity of phytoplankton found in nature appears to defy the competitive exclusion principle, and elucidating the mechanisms which maintain this diversity continues to be a challenge. In general, variability in limiting factors is required to maintain non-neutral species diversity, but this variability can be generated by forces outside of the competitive community (i.e. exogenous), or may be the outcome of competitive interactions themselves (i.e. endogenous). Using microcosm experiments, I showed that endogenously generated variability in limiting factors was more effective at maintaining phytoplankton species diversity over the long-term, although the strength of this effect depended on the composition of the phytoplankton community.
Existing resource diversity has been proposed to generally weaken consumer-resource interaction strengths and limit consumer control of resource biomass. This is because more diverse resource communities are more likely to contain inedible, unpalatable, toxic or non-nutritious species. However, when resource communities contain multiple palatable species, diversity may also accelerate consumption. Using grazing experiments with multiple zooplankton consumer species, I found that the mechanism, direction and magnitude of modulation of consumption depended on the feeding selectivity of the consumer and the composition of the resource community. By altering consumer-resource interaction strengths in the short-term, resource species diversity may impact the stability of consumer-resource dynamics in the long-term. In separate microcosm experiments, I investigated the influence of resource species diversity, community composition and consumer feeding selectivity on population, community, and ecosystem properties over time. Diversity had positive effects on phytoplankton population biomass, resource community biomass, the rate of photosynthesis, the standing stock of particulate nutrients, and the generalist consumer’s population density. It also stabilized resource community biomass and the stocks of particulate nutrients over time. Unexpectedly, diversity did not stabilize either of the consumer populations, regardless of feeding selectivity. This suggests that effects of diversity on resource community properties do not impact consumer dynamics linearly. Resource community composition was generally more important than resource species diversity in determining food web properties.
The importance of community composition in determining both the causes and consequences of resource diversity in these experiments points to the importance of species’ traits and the outcomes of their interactions. I suggest that the use of complex adaptive systems theory and trait-based approaches in the future will allow a consideration of the feedbacks between the causes and consequences of species diversity in food webs. / Graduate
|
4 |
Drivers and Hinders for Circular Land Use in the Swedish Built Environment / Drivkrafter och hinder för cirkulär markanvändning i svensk bebyggd miljöWohlers, Veronika January 2024 (has links)
Land qualifies as a finite, non-renewable resource. Converting natural or semi-natural land into built-up and artificial areas is understood as land take. Despite the EU’s ‘no net land take by 2050’ goal, the rate of land take is expected to continue unsustainably, particularly due to urban sprawl. The negative consequences of land take, namely landscape fragmentation, habitat loss and biodiversity decline, are, therefore, directly linked to the activities of the built environment sector. Land recycling, i.e. brownfield redevelopment, is key to reducing land take and enhancing circularity in land use. Although land use planning is recognised as a tool to both implement circular economy practices and reduce land take, land as a resource remains understudied in literature on circular economy in the built environment.This study focuses on circular land use in the form of green land recycling, grey land recycling, and densification and what drives and hinders circular land use for real estate developers and municipalities as key actors in land development in the Swedish built environment sector. It draws upon the Industrial Marketing and Purchasing (IMP) perspective by employing a resource interaction approach (RIA) to, firstly, map the resource interfaces of the focal resource land and secondly, explore the drivers and hinders for adapting to circular land use in these interfaces from the perspectives of real estate developers and municipalities.This cross-sectional interview study employed a mono-method qualitative methodology using semi-structured interviews to collect data. The interviews were conducted both with employees of Swedish municipalities and real estate developers based and active in Sweden. Thematic analysis was utilised to analyse data and structure the presentation of the findings.The findings allowed to identify specific resource combinations needed for land to become valuable for developers and municipalities. Valuable land for developers is determined by economic value, whereas for the municipalities social values are similarly important. In identifying key drivers and hinders the findings affirm the role of neighbours as hindering and future users and collaborations between the two actors as driving circular land use. Furthermore, the findings reveal the positive effects of land take restricting guidelines, emphasising the significance as well as the susceptibility of land use planning instruments in reducing land take. The study substantiates the understanding of circular land use and provides insights into drivers and hinders specifically for the context of land use in Sweden. Moreover, the application of the RIA in this context broadens the IMP perspective. / Mark är en ändlig, icke-förnybar resurs. Omvandling av naturlig eller halvnaturlig mark till bebyggda och konstgjorda områden kallas för ianspråktagande av mark. Trots EU:s mål om "no net land take by 2050" förväntas mark fortsättningsvis användas på ett ohållbart sätt, särskilt på grund av stadsutbredning. De negativa konsekvenserna av ianspråktagandet av mark, såsom landskapsfragmentering, förlust av livsmiljöer och minskad biologisk mångfald, är därför direkt kopplade till den byggda miljöns verksamhet. Återvinning av mark, dvs. ombyggnad av tidigare exploaterade områden, är en viktig faktor för att minska markanvändningen och öka cirkuläriteten i markanvändningen. Även om fysisk planering är ett erkänt verktyg för att både implementera cirkulär ekonomi och minska markanvändningen, finns det få studier som kopplar samman cirkularitet i den byggda miljön med markanvändning. Denna studie fokuserar på cirkulär markanvändning i form av så kallad grön och grå återvinning av mark och förtätning samt vad som driver och hindrar cirkulär markanvändning för fastighetsägare och kommuner som nyckelaktörer inom markutveckling i den svenska samhällsbyggnadssektorn. Studien utgår ifrån ett interaktivt perspektiv på resurser (RIA - Resource Interaction Approach) baserat på industriell nätverksteori (IMP - Industrial Marketing and Purchasing). RIA har använts för att kartlägga vilka andra viktiga resurser som krävs för att mark ska bli en värdefull resurs. Därigenom kunde centrala drivkrafter och hinder för cirkulär markanvändning identifieras, ur både privata fastighetsägares och kommuners perspektiv.Denna intervjustudie använde en kvalitativ metodik med semistrukturerade intervjuer för att samla in data. Intervjuerna genomfördes med anställda på svenska kommuner och fastighetsägare som är baserade och verksamma i Sverige. Tematisk analys användes för att analysera data och strukturera presentationen av resultaten.Resultaten visar på specifika resurskombinationer som gör att mark blir värdefull för privata fastighetsägare och för kommuner. Värdefull mark för fastighetsägare bestäms av det ekonomiska värdet, medan sociala värden är lika viktiga för kommunerna. De identifierade drivkrafterna och hindren bekräftar grannars roll i att hindra, och framtida användares samt samarbeten mellan dessa två aktörer i att driva på på cirkulär markanvändning. Vidare visar resultaten på de positiva effekterna av riktlinjer som begränsar markanvändningen, och betonar betydelsen av och mottaglighet hos planeringsinstrument för markanvändning för att minska ianspråktagande av mark. Studien ger större förståelse för cirkulär markanvändning ur ett interaktivt resursperspektiv och ger insikter om drivkrafter och hinder specifikt för markanvändningen i Sverige. Studien representerar också ett nytt empiriskt område för att tillämpa RIA och industriell nätverksteori.
|
Page generated in 0.1132 seconds