We live in an age where science fiction is quickly becoming science fact. Dick Tracy's 2-way wrist TVs are Apple Watches. Automated smart homes are plentiful. Cars are now able to drive themselves. And in those cars, riders no longer need to depend on a deejay to choose their music for them; these listeners build their own radio stations, on the spot, out of any music and conversation they want to hear, all at the touch of a button that is fully connected to Wi-Fi, the internet, and unlimited cell data plans.This research will examine digital radio's impact upon traditional radio in the current media environment. It will first take a look at the history of radio, specifically examining radio's reaction and adaptation when a new form of competitive media moved into the mass communication environment, and how radio fared in the face of that competition. The research will then look at uses and gratifications for both traditional and digital radio, which will be analyzed using media niche theory. From this, we will ascertain the niche breadth of each medium, as well as how much overlap exists between the two, and finally, which medium achieves niche superiority over the other in terms of gratifications observed.

In light of the niche theory, the study aims to understand the competition among the four telecommunication services, including fixed network telecom, second generation telecom service, third generation telecom service and internet phone in the taiwan market. In this study, we put emphasis on the gratification of the telecom user, because the more gratification the telecom get, the more competition it have. The findings suggest that there are eight factors about the gratification of the telecom consumer, including functional, affection, information-seeking, fashion, uitility, entertainment and pricing structure. In addition , there is strong competition between the fixed network telecom, second generation telecom service, third generation telecom service and internet phone. Four telecom services are good at different factors, therefore, new telecom services would not form competitive displacement for fixed network telecom. Thus, we argue that four telecom services satisfy different consumers needs, and they will survive in different segmentations of telecom market service.

Tradicionalmente, nichos populacionais são descritos como a somatória de todos os recursos utilizados por uma população. Entretanto, diversos estudos mostram que indivíduos dentro de uma população podem usar recursos de forma distinta. Investigamos três maneiras pelas quais indivíduos podem variar quanto ao uso do recurso. Indivíduos podem apresentar a mesma preferência por presas, mas diferir na propensão à adição de novos itens alimentares em sua dieta (Preferências Compartilhadas); indivíduos podem apresentar a mesma presa preferida mas diferirem em suas presas alternativas (Refúgio Competitivo); ou indivíduos podem apresentar presas preferidas distintas (Preferências Distintas). Estudamos os padrões de interação que emergem sob os pressupostos de cada um dos modelos usando redes de interação entre indivíduos e os recursos que eles consomem. Dessa forma, para derivarmos as previsões de cada um dos modelos de uso de recurso, desenvolvemos modelos simples que geram redes de interação segundo regras que seguem os pressupostos dos modelos e confrontamos essas previsões com dados empíricos, comparando a estrutura dessa redes de interação. Encontramos que o modelo que menos se assemelha ao padrão de uso de recurso observado para as populações estudadas foi o modelo de Preferências Compartilhadas. Para as populações estudadas, a variação intrapopulacional na escolha de presas parece estar mais associada a diferenças nas sequências de preferências por presas entre indivíduos e não à propensão desses indivíduos em adicionarem novos recursos às suas dietas. / Traditionally, a population\'s niche is described as the sum of all resources consumed by a population. However, several studies have highlighted that individuals within a population can use resources differently. We investigate three ways in which individuals can vary in their resource use. Individuals can show the same preference for prey, but differ in their likelihood of adding new prey to their diets (Shared Preferences); individuals can share the same top-ranked prey but differ in their alternative prey (Competitive Refuge); or individuals can have different top-ranked prey (Distinct Preferences). We studied the pattern of interaction that emerges under each model\'s assumption using interaction networks between individuals and the resources they consume. In this sense, to derive the predictions associated with each model of resource use, we developed simple models that generates interaction networks according to a set of rules that represent the assumptions of each model and then confronted these predictions with empirical data on interaction networks, by looking at the structure of these interaction networks. We found that the model that least resembles the pattern of resource use observed in the populations studied was the Shared Preferences model. For the studied populations, intrapopulation variation is not associated with individuals sharing the same rank sequence and differing in their willingness to add new resources to their diets. Instead, it seems that differences in the rank sequence of prey choice are more important in structuring the pattern of resource use in these populations.

In light of the niche theory, the study aims to understand the competition between the print magazine and the e-learning industries within the English language learning market in Taiwan. A niche analysis which compares the gratification niches of the two media was conducted in order to measure the patterns of resource use and to assess the superiorities. The findings suggest that there is strong competition between the two media. The e-learning meets a wider spectrum of needs and has a competitive displacement effect on the print magazine; the results indicate the e-learning¡¦s superiority over print magazine on the ¡§socialize,¡¨ ¡§economic,¡¨ and ¡§interaction¡¨ dimensions, whereas neither medium is superior on the ¡§choices¡¨ dimension. Significantly, the superiority in convenience of the e-learning may contribute to decreasing magazine use. Therefore, a medium should endeavor to better serve the needs for convenience, and to provide a wider choice of teaching materials.

Tradicionalmente, nichos populacionais são descritos como a somatória de todos os recursos utilizados por uma população. Entretanto, diversos estudos mostram que indivíduos dentro de uma população podem usar recursos de forma distinta. Investigamos três maneiras pelas quais indivíduos podem variar quanto ao uso do recurso. Indivíduos podem apresentar a mesma preferência por presas, mas diferir na propensão à adição de novos itens alimentares em sua dieta (Preferências Compartilhadas); indivíduos podem apresentar a mesma presa preferida mas diferirem em suas presas alternativas (Refúgio Competitivo); ou indivíduos podem apresentar presas preferidas distintas (Preferências Distintas). Estudamos os padrões de interação que emergem sob os pressupostos de cada um dos modelos usando redes de interação entre indivíduos e os recursos que eles consomem. Dessa forma, para derivarmos as previsões de cada um dos modelos de uso de recurso, desenvolvemos modelos simples que geram redes de interação segundo regras que seguem os pressupostos dos modelos e confrontamos essas previsões com dados empíricos, comparando a estrutura dessa redes de interação. Encontramos que o modelo que menos se assemelha ao padrão de uso de recurso observado para as populações estudadas foi o modelo de Preferências Compartilhadas. Para as populações estudadas, a variação intrapopulacional na escolha de presas parece estar mais associada a diferenças nas sequências de preferências por presas entre indivíduos e não à propensão desses indivíduos em adicionarem novos recursos às suas dietas. / Traditionally, a population\'s niche is described as the sum of all resources consumed by a population. However, several studies have highlighted that individuals within a population can use resources differently. We investigate three ways in which individuals can vary in their resource use. Individuals can show the same preference for prey, but differ in their likelihood of adding new prey to their diets (Shared Preferences); individuals can share the same top-ranked prey but differ in their alternative prey (Competitive Refuge); or individuals can have different top-ranked prey (Distinct Preferences). We studied the pattern of interaction that emerges under each model\'s assumption using interaction networks between individuals and the resources they consume. In this sense, to derive the predictions associated with each model of resource use, we developed simple models that generates interaction networks according to a set of rules that represent the assumptions of each model and then confronted these predictions with empirical data on interaction networks, by looking at the structure of these interaction networks. We found that the model that least resembles the pattern of resource use observed in the populations studied was the Shared Preferences model. For the studied populations, intrapopulation variation is not associated with individuals sharing the same rank sequence and differing in their willingness to add new resources to their diets. Instead, it seems that differences in the rank sequence of prey choice are more important in structuring the pattern of resource use in these populations.

The Unified Neutral Theory of Biodiversity has been advanced as a universal theory for species coexistence in forests worldwide, but few studies have examined its relevance to high-elevation, stressful environments. I established the Utah Forest Dynamics Plot (UFDP) in a heterogeneous subalpine forest at 3,091 m elevation on the Colorado Plateau to examine three underlying assumptions of neutral theory (functional equivalence, ecological equivalence, and habitat generality) and one prediction (the species abundance distribution). The UFDP comprises 27,845 stems ≥1 cm diameter at breast height of 17 species, 10 genera, and 6 families over 13.6 ha. The neutral model was a poor fit to the observed species abundance distribution, but I did not find the alternative lognormal model to provide a better fit. Using spatial pattern analyses of tree data, topography, and soil type, I found some limited support for the neutral theory assumptions of functional and ecological equivalency, with notable exceptions. Populus tremuloides, Pinus flexilis, and Pinus longaeva were characterized by non-neutral recruitment processes, and Abies bifolia and Populus tremuloides exhibited asymmetric competitive and facilitative interactions. The assumption of habitat generality was strongly contradicted, with all ten abundant species in the UFDP having habitat preference. In this subalpine temperate forest, species diversity and community structure are influenced more by habitat heterogeneity, species differences, and niche selection, with neutral processes playing a lesser role.

Impacts of humans on ecosystems in western United States have necessitated ecological restoration, which includes the development of native seed that can be used for revegetation efforts. Development of such seed sources are costly and time consuming. This study describes the use of non-parametric multiplicative regression analysis (NPMR) to develop a predictive model for occurrence of sulfur-flower buckwheat (Eriogonum umbellatum Torrey) population seed collection. This perennial forb species is of interest for seed source development in the western United States. Presence and absence data for E. umbellatum was taken from the Utah Division of Wildlife Resources Big Game Range Trend project as well as herbarium specimens across Utah, U.S.A. NPMR, a statistical niche modeling system that selects the best predictor variables and develops probability of occurrence estimates multiplicatively, was used to select predictor variables from spatially explicit data made available in a Geographic Information System (GIS). Two models were created using NPMR, one with a suggested default minimum average neighborhood size and the other with a less-restricted minimum average neighborhood size. GIS maps of models were created, artificially classified into low, medium, and high probability areas, and validated in the field in Tooele County, Utah. Of 68 possible physiographic, climatic, and soil variables provided for analysis, NPMR selected 4 variables for the default minimum average neighborhood model and 10 variables for the less restricted neighborhood model. The default model had a higher descriptive statistic (log β value) and mapped a larger area than the less restrictive neighborhood model. When increased minimum neighborhood sizes were selected during the development of the probability maps, the resulting areas of probability prediction decreased. The presence rates of E. umbellatum in field-validated test sites were 7.4%, 12.0%, and 28.6% for the low, medium, and high probability sites, respectively. Although presence rates of field validated data were lower than the predicted probability ranges for those same sites, presence rates increased with increased probability ranges. Using the generated model can reduce the cost and time necessary to locate plants compared to searching for species populations using an undirected approach.

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Submitted by Cássia Santos (cassia.bcufg@gmail.com) on 2016-09-21T11:25:10Z No. of bitstreams: 2 Dissertação - Fernanda Guimarães Fava - 2015.pdf: 1670100 bytes, checksum: 9979efb88c3552d0b60a34d9f6cf82d0 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Approved for entry into archive by Luciana Ferreira (lucgeral@gmail.com) on 2016-09-21T13:58:05Z (GMT) No. of bitstreams: 2 Dissertação - Fernanda Guimarães Fava - 2015.pdf: 1670100 bytes, checksum: 9979efb88c3552d0b60a34d9f6cf82d0 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Made available in DSpace on 2016-09-21T13:58:05Z (GMT). No. of bitstreams: 2 Dissertação - Fernanda Guimarães Fava - 2015.pdf: 1670100 bytes, checksum: 9979efb88c3552d0b60a34d9f6cf82d0 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Previous issue date: 2015-03-30 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / To simplify and measure all the great diversity of life on Earth we use models to summarize the processes driving community patterns. The community models structured by deterministic processes are based on species niche. Those models structured by stochastic processes are based on disperson and ecological drift. The spatial scale (i.e. extent) is a very important factor to evaluate the relative importance of deterministic and stochastic processes, because it determines the spatial and environmental heterogeneity. Traditionally, we consider that local species interactions with the environment and other species are important in explaining the diversity at the local level, while in larger geographic scales the differences in species niche could be not so important and these follow a probabilistic distribution of extinction and colonization processes. However, a opposite idea has arisen, that niche could have a greater influence on large scales and stochastic events may predominate at small scales. The organism type is also important for assemblies studies due to differences in dispersal ability. Tadpoles depend on the adult form to disperse and frogs generally have low movement ability. Thus, the spatial scale and the organism type will determine the relative importance of deterministic and stochastic factors in assemblies studies. / Para simplificar e conseguir mensurar toda a diversidade biológica existente na Terra utilizamos modelos que tentam sumarizar os processos que governam as comunidades. Modelos de comunidades estruturadas por processos determinísticos são baseados no nicho das espécies, enquanto os modelos de comunidades estruturadas por processos estocásticos são baseados na dispersão e deriva ecológica. A escala (aqui referida como extensão espacial) é um fator muito importante na avaliação da importância relativa de processos determinísticos e estocásticos, pois ela influencia a variação espacial e a heterogeneidade ambiental. Tradicionalmente, consideramos que as interações locais de espécies com o ambiente e outras espécies são importantes para explicar a diversidade em nível local e que em escalas geográficas maiores as diferenças no nicho das espécies podem não ser importantes, seguindo uma distribuição probabilística de processos de extinção e colonização. Porém, uma ideia contrária tem surgido, de que o nicho pode exercer uma maior influência em grandes escalas e eventos estocásticos podem predominar em pequenas escalas. O tipo de organismo também é importante para estudos de assembleias devido às diferenças na capacidade de dispersão. Girinos dependem da forma adulta para se dispersarem e os anuros em geral possuem baixa capacidade de movimentação. Desse modo, a escala e o tipo de organismo vão influenciar a importância relativa de fatores determinísticos e estocásticos em estudos de assembleias.

Submitted by Cássia Santos (cassia.bcufg@gmail.com) on 2016-09-23T10:56:00Z No. of bitstreams: 2 Dissertação - Barbbara da Silva Rocha - 2016.pdf: 2351043 bytes, checksum: d95e10f7a1753a91ecc8fa4dfc41a698 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Approved for entry into archive by Luciana Ferreira (lucgeral@gmail.com) on 2016-09-26T12:08:34Z (GMT) No. of bitstreams: 2 Dissertação - Barbbara da Silva Rocha - 2016.pdf: 2351043 bytes, checksum: d95e10f7a1753a91ecc8fa4dfc41a698 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Made available in DSpace on 2016-09-26T12:08:34Z (GMT). No. of bitstreams: 2 Dissertação - Barbbara da Silva Rocha - 2016.pdf: 2351043 bytes, checksum: d95e10f7a1753a91ecc8fa4dfc41a698 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Previous issue date: 2016-02-26 / Conselho Nacional de Pesquisa e Desenvolvimento Científico e Tecnológico - CNPq / One of the main focuses of ecology and biogeography has been better understanding as historical factors, environmental factors and dispersal ability influence the pattern of species distribution. Besides the environmental conditions and space being considered important components to control the variation in communities, another factor that can influence the beta diversity, but has been little studied, is the land use type. We aimed determine the relative influence of local, spatial components (directional and non-directional) and land use in the taxonomic and functional composition of phytoplankton and zooplankton communities in tropical reservoirs. Data was collected in 25 sampling points in reservoirs in the Rio Preto Basin, which is located in the Federal District-DF, Brazil. We performed a partial redundancy analysis to determine the influence of each component. The space was the only component with significant influence over the two groups (phytoplankton and zooplankton) and both approaches. Local variables had no significant influence on the variation of the communities, as well as the land use. Given the importance of space in the analyzed communities, we applied a protocol based on an spatial autocorrelation analysis, which indicated that the spatial pattern of the communities could be purely associated with dispersal by neutral factors. Our results demonstrated that the spatial component can be significant even in small scale studies to organisms with passive dispersal. Furthermore, it is important consider the connectivity among the environments in investigations with these microorganisms. as well as the use of the functional approach for studies of planktonic distribution, because of it show patterns similar to those found in the taxonomic approach. / Um dos principais focos da ecologia e biogeografia tem sido conhecer melhor como fatores históricos, ambientais e a capacidade de dispersão das espécies influenciam no padrão da distribuição das mesmas. Além das condições ambientais e do espaço serem considerados importantes componentes ao controlar a variação nas comunidades, outro fator que também pode influenciar a diversidade beta em ambientes aquáticos é o tipo de uso de solo. O objetivo do presente trabalho é determinar a influência relativa dos componentes locais, espaciais (direcional e não-direcional) e de uso de solo na composição taxonômica e funcional das comunidades fitoplanctônicas e zooplanctônicas em reservatórios tropicais. Os dados foram coletados em 25 pontos amostrais em reservatórios na Bacia do Rio Preto, que está localizada no Distrito Federal- DF, Brasil. Para determinar a influência relativa dos componentes realizamos uma análise de redundância parcial. O espaço foi o único componente com influência significativa sobre os dois grupos (fitoplanctônico e zooplanctônico) em ambas abordagens. As variáveis locais não apresentaram influência significativa sobre a variação das comunidades, assim como o tipo de uso de solo. Devido ao importante papel apresentado pelo espaço nas comunidades analisadas, foi aplicado um protocolo baseado em uma análise de autocorrelação espacial, na qual demonstrou que o padrão espacial das comunidades poderia ser associado puramente a fatores neutros de dispersão. Nossos resultados demonstraram que o componente espacial pode ser significativo mesmo em estudos de pequenas escalas para organismos com dispersão passiva. Além disso, é importante considerar a conectividade dentre os ambientes em investigações com esses microrganismos, bem como a utilização da abordagem funcional para estudos sobre a distribuição planctônica, pelo fato da mesma demonstrar padrões semelhantes aos encontrados na abordagem taxonômica.