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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
31

Asymmetry of Gains and Losses in Human Decision-Making and Choice: Behavioral Correlates of Loss Aversion, Money, Food, and the Menstrual Cycle

Ventura, Marcia Mackley 04 October 2022 (has links)
The purpose of this research is to determine if loss aversion is replicable as an overt behavioral response to potential gains and losses in complex, recurring, uncertain, and risky choice with real gains and losses of money and food. Cognitive methods used to determine the effect of loss have primarily measured verbal response to hypothetical choice scenarios in which participants cognitively predict their behavior in a series of bets or situations involving imagined monetary gains and losses. Less has been done using behavioral methods that measure overt behavioral response to gains and losses of actual commodities. The present study uses the experimental analysis of behavior to measure the asymmetrical effect of loss in multiple choice domains. A series of four experiments investigated four factors likely to affect the expression and degree of loss aversion: (a) learning and experience with consequences of choice; (b) real gains and losses instead of hypothetical quantities or imagined commodities; (c) gains and losses of a non-quantitative, primary reinforcer (food); and (d) the menstrual cycle. Participants played one of two computer games in which they earned or lost coins or food tokens exchanged for real food. Participants (N = 27, 15 women) played several 18-minute sessions in gains-only conditions and 16 sessions in 36-minute gains+punishment conditions. Recurring, complex, uncertain, and risky choice was simulated in the games by using 6-ply interdependent concurrent variable interval schedules of reinforcement (gains) and punishment (losses). Choice behavior with real gains and losses of money and food was modeled using the generalized matching law, allowing for the quantification of the effects of potential loss, relative to gains, as a change in bias and sensitivity. Loss aversion was operationalized as gain-loss asymmetry ratios derived from bias estimates produced in unpunished and punished choice conditions. Gain-loss asymmetry was replicated in both women and men in complex, recurring, uncertain, and risky choice with potential gains and losses of real money and food. Average gain-loss asymmetry ratios were 3 to 6 times greater in choice with money and 4 to 16 times greater in choice with food than those reported in the cognitive and behavioral literature. Although individual differences in response to loss were striking, the asymmetrically larger behavioral effects of loss, relative to gains, were nearly ubiquitous. Marked disruption in sensitivity to reinforcement was observed in punished choice for most participants, but for 33% of participants in choice with money and 42% in choice with food, sensitivity to reinforcers increased. No evidence was found for behavioral choice varying with the menstrual cycle.
32

Le langage de Claude Vivier : essai d’approche endogénétique d’un style musical

Rhéaume, Martine 04 1900 (has links)
La version intégrale de cette thèse est disponible uniquement pour consultation individuelle à la Bibliothèque de musique de l’Université de Montréal (www.bib.umontreal.ca/MU) / Cette recherche propose la description panoramique du style mélodique du compositeur québécois Claude Vivier (1948-1983) d’un point de vue qualifié d’endogénétique. L’entreprise repose sur l’analyse de seize (16) œuvres, composées entre 1973 et 1982 et allant de Chants à Samarkand. Il s’agit, en les considérant dans l'ordre chronologique de leur composition, de déterminer quels traits stylistiques mélodiques sont propres à chacune des œuvres, comment ils sont transformés d’une œuvre à l’autre, et quels traits stylistiques nouveaux apparaissent. Dans certains cas, une de ces caractéristiques est utilisée comme moteur unique d'une œuvre : un élément utilisé parmi d'autres dans certaines œuvres – la mélodie principale, la construction mélodique par ajouts de hauteurs, les accords-couleurs – apparaît comme l’élément principal d'une œuvre spécifique, pour ensuite être réintégré dans une autre, mais en étant ramené à un rôle secondaire au profit d'un autre élément. L’ensemble donne lieu à une description dynamique du style de Vivier comme évoluant de façon hélicoïdale plutôt que de façon linéaire. La thèse est constituée de trois chapitres précédés d'une introduction, consacrée au parcours biographique du compositeur, à la revue critique de la littérature analytique qui lui a été consacrée et à la notion de style. Le premier chapitre présente le choix des œuvres analysées et la méthodologie suivie, en particulier les principes de l'analyse paradigmatique, utilisée systématiquement pour chacune des seize œuvres analysées. Les parcours analytiques des œuvres forment le chapitre central de la thèse et permettent la constitution de fiches stylistiques dont les résultats sont compilés dans un tableau synthèse servant de base à un chapitre final où l’évolution endogénétique du style mélodique de Vivier est synthétisée. La seconde partie de la thèse présente en annexe les analyses paradigmatiques des seize œuvres, auxquelles renvoient les parcours analytiques du deuxième chapitre. Cette recherche a notamment démontré des similitudes d'axes paradigmatiques entre les œuvres, ce qui a donné lieu à une dénomination uniforme des axes d'une œuvre à l'autre ; ils sont décrits avec précision au début du second chapitre. Bien que la méthodologie utilisée donne une importance première au paramètre mélodique, les autres paramètres musicaux sont également mis en lumière dans les parcours analytiques. / This research proposes the panoramic description of the musical melodic style of Quebec composer Claude Vivier (1948-1983) from a perspective identified as endogenetic. The endeavour is based on the analysis of sixteen (16) works composed between 1973 and 1982, from Chants to Samarkand. This entails considering them in their chronological order of composition, so as to determine which stylistic traits are present in each work, how these are transformed from one work to the next, and what new stylistic melodic traits appear. In some cases, a single trait is used to propel an entire work: thus, an element that is one among many in certain works–the mélodie principale (principal melody), additive melodic construction based on pitch, accords-couleurs (colour-chords)–appears as the principal element of a particular work, to then be reintegrated into a subsequent work, this time in a subordinate role to some other element. Taken as a whole, these analyses lead to a dynamic description of Vivier’s style as having evolved in spirals rather than in a linear fashion. This dissertation is comprised of three chapters preceded by an introduction that is dedicated to the biographical elements of Vivier’s life, to a review of analytical literature devoted to the composer, and to a discussion of style as a concept. Chapter One presents the selection process of the works chosen for analysis and the methodology applied, in particular the fundamentals of paradigmatic analysis, used systematically for each of the sixteen works analyzed. The analytical overview for each of the works forms the core of the central chapter of the dissertation, facilitating the production of style index cards whose results are compiled in a summary chart that provides the foundation for the final chapter, where a synthesis of the endogenetic evolution of Vivier’s melodic style is presented. In the second part of the dissertation, an annex contains the paradigmatic analyses of all sixteen works, as referred to in Chapter Two during discussion of the analytical overview. In particular, this research has demonstrated the presence of similar paradigmatic axes between works, which has resulted in a standardization of the naming structure of these axes from one work to another; these are explained in detail at the beginning of the second chapter. Although the chosen methodology allots particular importance to the melodic parameter, the other musical parameters are also brought to light during the analytical overviews.
33

Autogene Regenerationserscheinungen in erzgebirgischen Moorwäldern und deren Bedeutung für Schutz und Entwicklung der Moore

Wendel, Dirk 19 July 2010 (has links)
- Ziele der Arbeit - Ziel vorliegender Arbeit ist, zu analysieren und zu beurteilen, in welchem Umfang autogene Moorregeneration nach anthropogenen Störungen auftritt, welche Voraussetzungen sie erfordert und welche Prozesse von Bedeutung sind. Forstliche und naturschutzfachliche Relevanz der Erkenntnisse sind zu prüfen. - Versuchsanlage und Methoden - Die Versuchsanlage umfasst verschiedene räumliche Skalenebenen und Zeitabschnitte. Im Untersuchungsraum sächsisches Erzgebirge befinden sich fünf Untersuchungsgebiete. Geschichtliche Aspekte werden auf Basis von Recherchen, der aktuelle Moorzustand anhand von Geländeerhebungen zu Vegetation und Standort analysiert. Langzeitbeobachtungen dienen dem Nachweis von Sukzessionsprozessen und den sie beeinflussenden Umweltfaktoren. Regenerationsprozesse werden anhand von Regenerationsmerkmalen, die eigens für diese Zwecke erarbeitet wurden, lokalisiert und im Kontext mit dem aktuellen Moorzustand und den Erfordernissen von Naturschutz und Forstwirtschaft interpretiert. - Ergebnisse und Schlussfolgerungen - - Das Aufnahmematerial lässt die Differenzierung von 28 Vegetationstypen zu, die anhand von Artengruppen und Zeigerwerten charakterisiert und als Kartiereinheiten zur Bewertung der Moore verwendet werden. Die Moorfläche im Untersuchungsraum wird auf 8.500 ha geschätzt. Jedes untersuchte Moor weist eine spezifische Kombination abiotischer sowie biotischer Merkmale auf und ist deshalb individuell zu bewerten. Entwässerungen und Torfstiche führen zu starker Degeneration, Dominanz von Wald, Seltenheit moortypischer Pflanzenarten, Offengesellschaften, nässegeprägter hydromorphologischer Strukturen sowie ökosystemrelevanter Schlüsselarten. Hinzu kommt eine Schädigung der Baum- und Moosschicht durch SO2-Immissionen bis in die 1990er Jahre und eine nachfolgende Regeneration. - Wiedervernässungen durch Graben- und Torfstichverlandung sind anhand von Zeitreihen und aktuellen Regenerationsmerkmalen nachweisbar. Autogene Moorregeneration kommt selbst in stark degenerierten Mooren vor. Regenerationsbereiche sind häufig, erreichen aber nur einen geringen Anteil an der Moorfläche (Untersuchungsraum: 1 %, Untersuchungsgebiete: 12 %). Sie haben meist mesotrophen Charakter. Eine erhöhte Regenerationsdisposition tritt u. a. bei konvergenten Wasserströmen und geringen Neigungen auf. Lokale Prozesse wie die Bildung von Fließhindernissen beeinflussen das Unwirksamwerden von Gräben. Die Etablierung torfbildender Vegetation nimmt eine Schlüsselstellung ein. Verschiedene Stufen eines diskontinuierlichen Regenerationsfortschritts sind zu unterscheiden und in bisher bekannte Prozessabläufe einzuordnen. Häufigkeit und Flächenverhältnis initialer und fortgeschrittener Regeration legen nahe, dass Regenerationsprozesse auf größerer Fläche ablaufen, jedoch nicht erkannt werden. Regeneration führt zu Standortsdrift und Ausbreitung moortypischer Arten. Das Regenerationspotenzial ist abiotisch vorgegeben. Irreversible Veränderungen der hydromorphologischen Struktur durch Entwässerung oder Torfabbau setzen der Regeneration Grenzen. Anthropogene Stoffeinträge und Mangel an Schlüsselarten bewirken weitere Einschränkungen. - Soweit eine rentable Holzproduktion Ziel ist, stellen autogen regenerierende Moore schwer bis nicht bewirtschaftbare Standorte dar, die aufgrund von Standortsdrift und teils Gehölzfeindlichkeit ein hohes Produktionsrisiko bergen. Naturschutzfachlich sind Regenerationsprozesse eine Chance und ein bedeutendes Schutzgut, da sie zu höherwertigeren Moorlebensräumen führen. Bei fortgeschrittener Regeneration erübrigen sich kostenintensive Eingriffe. Ein statischer Schutz wird dem Prozesscharakter nicht gerecht. Initialstadien und Bereiche, die noch nicht regenerieren, aber ein hohes Potenzial aufweisen, lassen sich effizient fördern. Die starke Degeneration der Moore im Untersuchungsraum begründet bei geringem Anteil aktueller Regenerationsbereiche einen hohen Handlungsbedarf, einschließlich eines abschirmenden Schutzes sowie effizienter Kontrollmechanismen. - Geeignete Datengrundlagen zur Lokalisierung von Flächen mit einem hohen Regenerationspotenzial fehlen weitgehend. Eine Behebung dieses Defizits ist möglich. / - Objectives - The objective of this work is to analyse and to assess to which extent autogenous peatland regeneration occurs after anthropogenic disturbances, what preconditions it requires and what processes are important. Relevance of the findings for forestry and nature conservation is to be examined. - Experimental set-up and methods - The experimental set-up comprises various spatial scale levels and time periods. Five study sites are located in the study area Saxon Erzgebirge Mountains. Historical aspects are analysed based on investigations, the actual condition of the peatland is determined by ground surveys focusing on the vegetation and the site. Long-term observations serve to prove succession processes and the environmental factors influencing them. Regeneration processes are localized by means of regeneration characteristics, which were elaborated just for this purpose, localized, and interpreted in the context of the actual peatland condition and of the requirements of nature conservation and forestry. - Results and conclusions - - The material under survey allows distinguishing between 28 vegetation types which are characterised by means of species groups and indicator values and which are used as mapping units for evaluating the peatlands. The peatland area in the study area comprises an estimated 8500 ha. Each investigated peatland has a specific combination of abiotic and biotic characteristics and therefore needs to be evaluated individually. Drainage and peat cuttings lead to strong degeneration, dominance of forest, rarity of plants species typical of peatland, open-land associations, wetness-coined hydromorphological structures as well as ecosystem-relevant key species. In addition, the tree and moss layer had been damaged by SO2-pollution up to the 1990ies and a succeeding regeneration. - Recurring wetting due to filling-up of ditches and peat cuttings by sedimentation are verifiable by time sequences and actual regeneration characteristics. Autogenous peatland regeneration occurs even in heavily degenerated peatlands. Regeneration areas are frequent, accounting, however, only for a small share at the peatland area (study area: 1 %, study sites: 12 %). Often they are of mesotrophic nature. An increased disposition to regeneration is found, among others, in case of convergent water flows and slight inclinations. Local processes like the formation of obstacles for the flowing may cause ditches to become ineffective. Establishing of peat-forming vegetation is a crucial phenomenon. Various stages of a discontinuous regeneration progress can be differentiated and allocated to the processes that are known so far. Frequency and the area ratio of initial and progressed regeneration suggest that regeneration processes take place on a larger area, but that they are not recognised. Regeneration leads to site drifting and the distribution of peatland species. The regeneration potential is given by abiotic conditions. Irreversible changes of the hydro-morphological structure due to drainage or peat cutting are limiting factors for the regeneration. Anthropogenic input of matter and lack of key species bring about other restrictions. - If a profitable timber production is aimed at, autogenously regenerated peatlands are sites difficult to manage or that cannot be managed at all, involving a high production risk due to site drifting and partly inadequacy for woody plants. For nature conservation, regeneration processes are a chance and an important asset worth of protection, as they lead to high-grade peatland habitats. In the case of advanced regeneration cost-intensive operations are not necessary. A protection of static nature is inadequate for the process character. Initial stages and zones not yet under regeneration, implying, however, a high potential, can be promoted efficiently. Heavy degeneration of the peatlands in the study area, given a low proportion of actual regeneration zones, justifies a strong call for action, including a shielding protection as well as efficient control mechanisms. - An appropriate data basis for localisation of areas, having a high regeneration potential, is largely missing. Remedying this deficit is possible.

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