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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.
571

The Venture Capital behavioral bias and the ecosystem investment flows : A comparative quantitative study about the relationship between Venture Capitalist's drivers and their investment behavior in Stockholm and Silicon Valley

Cottin Arredondo, Randall Ismael, Garry, Enzo January 2017 (has links)
The purpose of this study is to test if there is bias in the Venture Capital investment decision-making process towards ecosystems. To guide the research and ensure the fulfillment of the study’s main purpose, we will analyze two specific ecosystems (Stockholm and Silicon Valley). This choice is motivated by their respective importance (Worldwide and Nordics reference) in the global entrepreneurial landscape. The aim is to make an empirical contribution regarding how a herding behavior from Venture Capital investments can drive irrational investment flows towards specific ecosystem such a Silicon Valley, regardless available information towards other ecosystems, in this case, Stockholm. Most researches until today have been focusing on the assessment of startup-focused factors which we believe only picture partly the attractiveness of a startup ecosystem. In our perception, environmental factors in which the ecosystem take place also play an essential role in the attractiveness of an ecosystem to invest in. Is there a behavioral bias in the investment decision processes of Venture Capital regarding startup ecosystems? To assess the presence or absence of a behavioral bias in the investment decision of Venture Capital investors, we are first going to establish an objective attractiveness score using environment-based factors. These factors are going to be combined into six main variables that picture the environmental attractiveness of both ecosystems. In a second time, we are going to submit these six variables to two populations of investors operating in each ecosystem. To do so, we will operate a quantitative study of Stockholm and Silicon Valley-localized private Venture Capital investors towards our different environmental variable. This will enable us to obtain their specific drivers toward these variables and therefore adapt our objective attractiveness scores to obtain weighted attractiveness scores. In a third time, we are going to compare our obtained weighted attractiveness scores per ecosystem with the investment flows effectuated respectively in both ecosystems in 2016. To be able to compare both settings on the same range, we are going to calculate both investment flow data: investment volumes and number of deal closed per capita. The results of this comparison will then bring us either a correlation relation between weighted attractiveness and investment flows per capita for both ecosystems, infirming our theory or a non-correlative relation, which would confirm our theory. Indeed, a non- correlative relation will show that investors do no follow a rational investment behavior based only on the attractiveness of their ecosystem.
572

Jsou žraloci cennější živí nebo mrtví? Analýza projevených preferencí ohledně ekoturistiky a výprav za žraloky v Kostarice. / Are Sharks Worth More Alive Than Dead? A Stated Preference Study on Shark Ecotourism in Costa Rica.

Berrios, Alicia Maria January 2017 (has links)
i Charles University Faculty of Social Sciences Institute of Economic Studies MASTER'S THESIS Are Sharks Worth More Alive Than Dead? A Stated Preference Study on Shark Ecotourism in Costa Rica. Author: Bc. Alicia Maria Berrios Supervisor: Mgr. Milan Ščasný PhD. Academic Year: 2016/2017 ii Declaration of Authorship The author hereby declares that he compiled this thesis independently; using only the listed resources and literature, and the thesis has not been used to obtain a different or the same degree. The author grants to Charles University permission to reproduce and to distribute copies of this thesis document in whole or in part. Prague, January 01st , 2017 Signature iii Acknowledgments With boundless appreciation, I would like to extend my gratitude to Mgr. Milan Ščasný PhD., for his incredible support in writing this research. He spent a countless number of hours on this thesis work, and ultimately, this research wouldn't have been possible without him. I would also like to express my gratitude to Carlos Avila, for his generosity in helping me conduct the in-person interviews. I would also like to express my gratitude to Prof. Melville Saayman, who helped tremendously in the experimental design of this work. Thank you to Mgr. Martin Kryl for programming the survey instrument. Lastly, I would like to...
573

Tourism as a tool for communicating complex environmental issues : Applying the ecosystem services framework to nature-based tourism activities across Iceland

Burfoot, Christopher January 2017 (has links)
Throughout the twenty-first century, the lowering cost and increased availability of travel options has resulted in virtually uninterrupted economic growth of the international tourism sector. While financially beneficial, the increased movement of people has also been shown to have a negative impact on the environment, leading to the growth of a more environmentally-friendly approach to travel called nature-based tourism. One country at the forefront of the nature-based tourism movement is Iceland, and while the sector has grown significantly in the country over the past decade, the way in which information concerning environmental issues is communicated to tourists has not been widely researched. Being the case, the aim of this study was to examine the extent to which environmental issues are communicated to the general public through the use of the ecosystem services framework. Four popular nature-based tourism activities were selected for analysis; a whale watching tour, a horse riding tour, a boat tour of a glacial lagoon and a spa experience in a geothermal hot spring. A literature review concerning how the ecosystem services framework related to each of these tours was carried out and findings were compared to observatory data gathered through participation in said tourism activities. Results showed that while scientific publications could be found for each tour/ecosystem service combination, information concerning environmental issues was not widely communicated to participants in the nature-based tourism activities using the ecosystem services framework.
574

Biofuel feedstocks: implications for sustainability and ecosystem services

Diop, El Hadji Habib Sy January 1900 (has links)
Doctor of Philosophy / Department of Agronomy / Charles W. Rice / Biofuel feedstocks such as grains and cellulose are gaining increased attention as part of the U.S. portfolio of solutions to address climate change and improve energy security. As the future of biofuels unfolds, major concerns are emerging, including the sustainability of the soil resource in bioenergy cropping system. With a clear understanding of the sustainability risks that exist within the agricultural soil resources, it is now essential to develop metrics that document the soil health as well as the total biomass production of different cropping system. We tested the effectiveness of eight bioenergy plant species grouped between annual and perennial crops. Our main objective was to determine the sustainability of bioenergy cropping systems. There was significantly greater soil structural stability plus greater root biomass under the perennial crops but greater aboveground biomass in the annual crop. Differences in soil carbon measured to 1.2 m were not significant between energy crops after five years. A transparent, unbiased method to identify possible change in soil characteristics under bioenergy cropping practice was offered. Our next metrics were soil aggregate stability and microbial community structure as indicators of soil ecosystem health and environmental stability. The effects 24 years of differing levels of residue and fertilizer inputs on soil aggregate stability, aggregate C and microbial community structure were evaluated. A native, undisturbed prairie site, located nearby was used as a reference in this study. The results showed that greater inputs of inorganic N and increased returns of crop residues did not cause a proportionately greater increase in SOC. The abundance of microbial parameters generally followed their potential carbon pool in cultivated soils but a strong mismatch was observed in the native prairie site. Our results showed for the first time a clear disconnect between decomposers and macroaggregates; highlighting the role of soil structure in protecting organic matter. Soil carbon sequestration is one of the mechanisms that have been proposed as temporary measure to mitigate global climate change. However, there was a particularly large risk of negative effects of mitigation measures related to the increased removal of crop residues from cropping systems for use in bioenergy, if this means that soil carbon is reduced. Effective measurement of soil C at the field scale requires an understanding of the spatial variability of soil C on a landscape scale. Recent technological advances in soil C measurement offer new opportunities in this area. Our surface measurements of soil C by near infrared spectroscopy (NIRS) provided a quick assessment of soil C and, soil C predicted by NIRS and measured by dry combustion laboratory measurements was correlated with and R-squared of 0.84.
575

Microbial Ecosystem Functions Along the Steep Oxygen Gradient of the Landsort Deep, Baltic Sea

Thureborn, Petter January 2016 (has links)
Through complex metabolic interactions aquatic microbial life is essential as a driver of ecosystem functions and hence a prerequisite for sustaining plant and animal life in the sea and on Earth. Despite its ecological importance, infor­mation on the complexity of microbial functions and how these are related to environmental conditions is limited. Due to climate change and eutrophication, marine areas facing oxygen depletion are increasing and predicted to continue to do so in the future. Vertically steep oxygen gradients are particularly pronoun­ced in the Baltic Sea. In this thesis, therefore, the ecosystem functions of micro­bial communities were investigated, using metagenomics, to understand how they were distributed along the steep oxygen gradient at the Landsort Deep, the deepest point of the Baltic Sea. Furthermore, microbial communities from the Lands­ort Deep transect were compared to microbial communities of other marine environments to establish whether the environment at this site resulted in a characteristic community. To reveal what microbial community functions and taxa were active in the anoxic sediment a metatranscriptomic approach was used. Results showed a marked effect of the coupled environmental parameters dissolved oxygen, salinity and temperature on distribution of taxa and par­ti­cularly community functions. Microbial communities showed functional capa­cities consistent with a copiotrophic life-style dependent on organic ma­terial sinking through the water column. The eutrophic condition with high organic load was further reflected in the metatranscriptome of the anoxic sedi­ment com­munity, which indicated active carbon mineralisation through ana­erobic hetero­trophic-autotrophic community synergism. New putative linkages between nitro­gen and- sulphur metabolisms were identified at anoxic depths. Further­more, viable Cyanobacteria in the anoxic sediment was evident from the tran­script analyses as another reflection of marine snow. High abundance and expres­­sion of integron integrases were identified as a charac­teristic feature of the Lands­ort Deep communities, and may provide these communities with a mech­an­ism for short-term-adaptation to environmental change. In summary, this thesis clearly documents what impact eutrophication and oxygen depletion have on microbial community functions. Furthermore, it specifically advances the mechanistic insight into microbial processes in anoxic deep-water sediment at both genomic and transcriptional level. Given the predicted progress of oxygen depletion in marine and brackish environments, this work advances information necessary to estimate effects on marine and in particular brackish ecosystem functions where anoxic conditions prevail. / Mikroorganismer är essentiella för fungerande ekosystemfunktioner i akvatiska miljöer och därmed en förutsättning för övrigt växt- och djurliv på vår planet. Trots deras ekologiska nyckelroll är kunskapen om mikroorganismernas funk­tion och komplexitet samt hur dessa är relaterade till miljön begränsad. På grund av eutrofiering och klimatförändringar har marina områden som lider av syrebrist ökat och en ytterligare utbredning av marina och bräckta områden med syrebrist är predicerad i framtiden. Stora områden av Östersjön kännetecknas av vertikala syregradienter med syresatt ytvatten och anoxiskt bottenvatten. I denna avhandling undersöktes därför med metagenomik hur mikrobiella ekosystems funktioner var utbredda längs den vertikala syregradienten i Östersjöns djupaste del, Landsortsdjupet. Dessutom jämfördes de mikrobiella samhällena från Lands­­­ortsdjupet med mikrobiella samhällen från andra marina miljöer för att utröna om den karakteristiska miljön i Landsortsdjupet återspeglade de mikro­biella samhällen som lever där. För att undersöka vilka mikroorganismer samt vilka mikrobiella ekosystemfunktioner som var aktiva i det anoxiska sedimentet i Lands­ortsdjupet användes metatranskriptomik. Resultaten visade en stark kor­re­lation mellan miljöparametrarna syrehalt, salinitet och temperatur och för­del­ningen av mikrobiell taxa och i synnerhet mikrobiell funktion längs Lands­orts­djupets transekt. De mikrobiella samhällena uppvisade en funktionell kapa­citet förenlig med en livsstrategi beroende av organiskt material som sjunker genom vattenkolonnen som en konsekvens av eutrofiering. Eutrofa förhållanden med hög halt av organiskt material var även återspeglad i metatranskriptomet från det anoxiska sedimentet, som indikerade aktiv mineralisering av organiskt kol genom anaerob heterotrof-autotrof synergism. Nya möjliga kopplingar mellan kväve- och svavelmetabolism identifierades i det anoxiska vattnet. Vidare visade resultat från metatranskriptom-analys att livsdugliga cyanobakterier var abun­danta i det mörka och anoxiska sedimentet, vilket även detta kan vara en konse­kvens av sjunkande organiskt material. Hög abundans och hög transkribering av integrongener kunde identifieras som ett karakteristiskt kännetecken hos de mikro­biella samhällena i Landsortsdjupet vilket skulle kunna förse dem med en me­kanism för anpassning till miljöförändringar. Sammanfattningsvis dokumen­terar denna avhandling tydligt vilken påverkan eutrofiering och syrebrist har på mikrobiella funktioner. Dessutom för den specifikt kunskapen om mikrobiella processer i anoxiska djupvattensediment framåt på både genom- och transkrip­tions­nivå. Mot bakgrund av en predicerad ökning av syrebristen i marina mil­jöer, bidrar denna avhandling med information som är viktig för att kunna förutse vilka effekter anoxiska förhållanden kan komma att få på ekosystemfunktioner i marina miljöer och i brackvattenmiljöer i synnerhet.
576

Biotic responses to alterations in habitat-flow as a result of water abstraction and release in the lower Elands (Mpumalanga) and Mvoti (Kwazulu-Natal) Rivers, South Africa

15 August 2008 (has links)
The South African National Water Act (NWA) (No. 36 of 1998) recognises that in order to sustain the goods and services that are provided by rivers and their associated biological communities, it is necessary to conserve the entire aquatic ecosystem. Conservation and maintenance of ecosystem functioning entails the protection of the biotic components (i.e. fish, macroinvertebrates, riparian vegetation, etc.) and ensuring that the abiotic driver aspects (i.e. required amount and variability of flow, water quality and fluvial geomorphology) are addressed and met (Malan and Day, 2003). According to the Reserve Determination methodology (DWAF, 2003), sustainable utilisation of the river resources requires proper, responsible management and that exploitation without understanding or limits, impacts negatively on the ecological processes, functions and communities, both in the present and the future. Manipulation of the flow regimes of rivers, to provide water when and where people need it, has resulted in a growing deterioration in the condition (health) of riverine ecosystems (King et al., 2000). Stressors on aquatic ecosystems originating from these anthropogenic activities, include point and non-point loadings, land use influences and changes, and stream modification. These are usually defined by the drivers of aquatic ecosystems namely the geomorphology, hydrology and water quality. In turn, the effects on the physical habitat and water quality have both direct and indirect effects on the biotic communities present and are usually defined by biological responses to these changes (Kleynhans et al., 2005). There is currently limited data available to formally propose a methodology to quantify the significance of altered flows in riverine ecosystems brought about by the abstraction or excessive release of water by industrial activities on a reach scale. The aim of this study was to determine the degree and magnitude of habitat-flow alterations caused by pulp and paper mill activities in the Elands and Mvoti Rivers and to link the related biological responses to them. / Prof. V. Wepener
577

Regional scale risk assessment methodology using the relative risk model as a management tool for aquatic ecosystems in South Africa

05 November 2012 (has links)
Ph.D. (Zoology) / Due to the excessive utilisation of the ecological services of surface aquatic ecosystems in South Africa, the integrity state of these systems continues to decline resulting in the loss of key ecosystem services. This trend suggests that the national requirements to maintain a sustainable balance between the use and protection of these systems are not being met. In an attempt to address this status quo, all stakeholders of these systems need to become more closely engaged in the social and institutional decision making processes to manage these systems. Management plans need to be integrated and take a wide range of conservation and use objectives for specific ecosystems into account. Furthermore, approaches need to allow for the assessment of multiple stressors that have synergistic effects, while the unique characteristics of the ecosystem taken into consideration. Risk assessments entail assigning magnitudes and probabilities to hazards or anthropogenic activities or natural catastrophes that have adverse effects m ecosystems. In these assessments the existence of a hazard and the related uncertainty of its effects results in the formulation of risk. An Ecological Risk Assessment is a structured approach that describes, explains and organises scientific facts, laws and relationships, thereby providing a sound basis to develop sufficient protection measures for the environment, which facilitates the development of utilisation strategies for the environment. A Regional Scale Risk assessment using the Relative Risk Model (RRM) is a form of Ecological Risk Assessment that is carried out on a spatial scale where considerations of multiple sources of multiple stressors affecting multiple endpoints are allowed. The use of the RRM also allows for the characteristics of the landscape that may affect the risk estimate to be considered. This study is based on a research hypothesis that the RRM is a suitable water resources management tool that can address the risk assessment of multiple stressors in South African freshwater environments. To test this hypothesis this study aims to contextualise the RRM methodology within the current water resources management practices in South Africa and demonstrate the applicability of RRM within the South African water resources management framework. The applicability of the RRM will be tested using two case study regions. The case studies are the Elands River and its associated ecosystems in the upper Crocodile River catchment in Mpumalanga and the entire catchment of the Umvoti River in KwaZulu-Natal
578

Enhancing User Engagement in Electronic Commerce Through the Transition to a Digital Ecosystem

Yang, Binbin January 2016 (has links)
Electronic Commerce (EC) companies are faced with a highly competitive environment today. Strengthening user engagement in digital ecosystems is a promising approach to increasing value co-creation. However, enterprise-oriented user engagement strategies examined in previous studies are relatively inadequate to meet today’s expectations. This paper looks to answer the question, “how to effectively strengthen user engagement to acquire a sustainable value co-creation system in EC.” A plausible user engagement strategy was revealed by analyzing a single case study in the music sector based on details of a digital ecosystem. Semi-structured interviews performed with company Xiami along with their users, show that the recognition of user-oriented needs and the expansion of user-driven demands are two key aspects for EC companies to maintain a sustainable growth of value co-creation.
579

Benefits from ecosystem services in Sahelian village landscapes

Sinare, Hanna January 2016 (has links)
Rural people in the Sahel derive multiple benefits from local ecosystem services on a daily basis. At the same time, a large proportion of the population lives in multidimensional poverty. The global sustainability challenge is thus manifested in its one extreme here, with a strong need to improve human well-being without degrading the landscapes that people depend on. To address this challenge, knowledge on how local people interact with their landscapes, and how this changes over time, must be improved. An ecosystem services approach, focusing on benefits to people from ecosystem processes, is useful in this context. However, methods for assessing ecosystem services that include local knowledge while addressing a scale relevant for development interventions are lacking. In this thesis, such methods are developed to study Sahelian landscapes through an ecosystem services lens. The thesis is focused on village landscapes and is based on in-depth fieldwork in six villages in northern Burkina Faso. In these villages, participatory methods were used to identify social-ecological patches (landscape units that correspond with local descriptions of landscapes, characterized by a combination of land use, land cover and topography), the provisioning ecosystem services generated in each social-ecological patch, and the benefits from ecosystem services to livelihoods (Paper I). In Paper II, change in cover of social-ecological patches mapped on aerial photographs and satellite images from the period 1952-2016 was combined with population data and focus group discussions to evaluate change in generation of ecosystem services over time. In Paper III, up-scaling of the village scale assessment to provincial scale was done through the development of a classification method to identify social-ecological patches on medium-resolution satellite images. Paper IV addresses the whole Sudano-Sahelian climate zone of West Africa, to analyze woody vegetation as a key component for ecosystem services generation in the landscape. It is based on a systematic review of which provisioning and regulating ecosystem services are documented from trees and shrubs on agricultural lands in the region. Social-ecological patches and associated sets of ecosystem services are very similar in all studied villages across the two regions. Most social-ecological patches generate multiple ecosystem services with multiple benefits, illustrating a multifunctional landscape (Paper I). The social-ecological patches and ecosystem services are confirmed at province level in both regions, and the dominant social-ecological patches can be mapped with high accuracy on medium-resolution satellite images (Paper III). The potential generation of cultivated crops has more or less kept up with population growth in the villages, while the potential for other ecosystem services, particularly firewood, has decreased per capita (Paper II). Trees and shrubs contribute with multiple ecosystem services, but their landscape effects, especially on regulating ecosystem services, must be better studied (Paper IV). The thesis provides new insights about the complex and multi-functional landscapes of rural Sahel, nuancing dominating narratives on environmental change in the region. It also provides new methods that include local knowledge in ecosystem services assessments, which can be up-scaled to scales relevant for development interventions, and used to analyze changes in ecosystem services over time. / <p>At the time of the doctoral defense, the following papers were unpublished and had a status as follows: Paper 2: Manuscript. Paper 3: Manuscript.</p><p> </p>
580

An Assessment of the U.S. Army Corps of Engineers' Environmental Plan Evaluation Methods

Holland, Michael 20 May 2011 (has links)
The U.S. Army Corps of Engineers is a federal agency with a mission to develop water resource projects to benefit the nation. Some of its large scale projects have been built to benefit cities, but through unintended consequences have caused economic and environmental damages. For example, its control of Mississippi River flooding has protected the City of New Orleans, but contributed to land loss in coastal Louisiana, and by some accounts, made the population more susceptible to hurricane damage. The agency has now embarked on a mission to restore some of the damaged environmental areas. This dissertation evaluates whether policies and practices used by the agency to evaluate and select plans to implement is logically flawed and could produce suboptimal project selection. The primary issue is the practice of including only implementation costs in the analysis while excluding other positive and negative economic impacts. A case study is performed using the method to evaluate a traditional economic development project for which optimal project selection has already been determined using widely accepted benefit-cost practices. The results show that the Corps' environmental project evaluation method would cause rejection of the most efficient plan. The loss of welfare that would result from using this technique is measured by comparing the welfare gain of the optimal project to the welfare gain of the suboptimal projects which could be selected using the flawed methodology. In addition, the dissertation evaluates whether suboptimal results could be produced using two other current Corps policies: selecting projects based on production efficiency, and the exclusion of environmental benefits from the discounting process. For the first policy, a simple counter example shows how clearly inferior choices may come from including only supply considerations in investment choices. For the second policy, it is demonstrated mathematically that refraining from discounting benefits while discounting costs causes a bias towards selection of plans that take longer to build, are delayed in their implantation, or a combination of the two.

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