Parasteatoda tepidariorum is a cob-web weaving spider abundant in both urban and rural areas across the temperate regions of the globe. They are typically found in sheltered areas such as garages, porches, caves, and between stones where they are able to construct a three-dimensional web structure. Because these organisms function as both predator and prey, proper habitat selection is vital for the survival of the individual. Individuals of this species must find locations that are conducive to high levels of prey availability but also sheltered to avoid undue predator exposure. In their natural habitats, these locations tend to be shaded. Because these spiders do not readily move locations once their webs are built, proper habitat choice is important. With this information in mind, these apparent preferences in habitat may infer specific inclinations towards light exposure. These interactions, however, have not been thoroughly investigated. Because of the natural variation of light levels in these habitats, we hypothesize that these spiders may be utilizing light levels in habitat choice. In this study, we aimed to detect any indications of preferences using adult female P. tepidariorum. Spiders were captured in Sullivan and Washington counties in Tennessee and were returned to the lab where they were maintained under standard conditions prior to being placed into the experimental chamber. This experimental chamber consisted of two concentric circles that created a consistent tunnel structure for web-building throughout. A light gradient was constructed so that one side of the circular tunnel had the maximum light exposure of 410 lux and the other side faded to 0 lux. The chamber was placed in a controlled environment with a 12 h light:12 h dark cycle at ~24° C. One spider was placed into the choice chamber at a time and allowed three full days to explore and choose an environment in which to build a web. After three days, the location of the spider was recorded, and the spider was removed. The chamber was cleaned with ethanol and allowed to dry before another spider was placed into the chamber. Each spider was repeated at least twice. All individuals built webs in the dark half of the arena, and there was a significant preference for very low light (but not complete darkness). These results indicate that P. tepidariorum may select habitats based on light exposures. By investigating these preferences, we are able to get a better understanding of how P. tepidariorum interpret their environment to choose proper web locations.

Made available in DSpace on 2016-01-26T18:56:30Z (GMT). No. of bitstreams: 1 Graziele Cristina de Oliviera.pdf: 394148 bytes, checksum: 62431a9e3875b8437fc76808bdfa964c (MD5) Previous issue date: 2014-04-02 / Studies related to the pursuit of a favorable environment for the production of medicinal plants with a focus on optimizing the synthesis of active substances are necessary in view of the economic and social importance of these species. This study aimed to evaluate the effect of quantitative and qualitative control of the spectrum of light transmitted through the shading nets on growth and essential oil production in plants of Melissa officinalis L. The experiment was conducted in Presidente Prudente / SP. Plants were potted and subjected to shading treatments offered by black net (retention of 50 %), Chromatinet ® red and blue shading nets (50 %) and full sun for a period of 120 days after transplanting (DAT) , in which two cuts were performed. It was determined the global solar radiation, the photosynthetic photon flux density, the chlorophyll content , the plants gas exchange, biometric and anatomical parameters and content and yield of essential oil in leaves . The experiment was performed in a completely randomized design with 4 treatments and 5 replications. Based on the results, it was found that despite melissa be considered as a plant with better development in shaded environments, this specie has adapted to the condition of full sun, in which the photosynthetic data were more significant , indicating no damage to the photosynthetic apparatus. However, the use of the blue net resulted in higher biomass production and essential oil content in plants, and therefore its utilization is indicated for Melissa production. No anatomical changes were observed as a result of the cultivation of Melissa under different quantity and quality of light. / Estudos relacionados à busca de um ambiente favorável de produção de plantas medicinais com foco na otimização da síntese de substâncias ativas se fazem necessários tendo em vista a importância econômica e social destas espécies. O presente trabalho teve o objetivo de avaliar o efeito do controle quantitativo e qualitativo do espectro de luz transmitidas através das malhas fotoconversoras sobre o crescimento e a produção de óleo essencial em plantas de Melissa officinalis L. O experimento foi conduzido em Presidente Prudente/SP. As plantas foram conduzidas em vasos e submetidas aos tratamentos de sombreamento proporcionados por malha preta de retenção de 50%, malhas fotoconversoras Chromatinet® vermelha (50%) e azul (50%) e pleno sol, por um período de 120 dias após o transplantio (DAT), no qual foram realizados dois cortes. Determinou-se a radiação solar global, a densidade de fluxo de fótons fotossintéticos, o índice de teor de clorofila, as trocas gasosas, os parâmetros biométricos e anatômicos e o teor e o rendimento de óleo essencial das folhas. O experimento foi conduzido seguindo delineamento inteiramente casualizado com 4 tratamentos e 5 repetições. Diante dos resultados obtidos, verificou-se que apesar da melissa ser considerada uma planta de com melhor desenvolvimento em meio sombreado, esta espécie se adaptou à condição de pleno sol, na qual os dados fotossintéticos foram mais expressivos, indicando a ausência de danos ao aparato fotossintético. No entanto, a utilização de malha azul resultou maior produção de biomassa e teor de óleo essencial nas plantas, sendo, portanto indicada sua utilização para o cultivo de melissa. Não foram observadas modificações anatômicas em decorrência do cultivo da melissa sob alteração da quantidade e qualidade da luz.

Made available in DSpace on 2016-07-18T17:51:13Z (GMT). No. of bitstreams: 1 Graziele Cristina de Oliviera.pdf: 394148 bytes, checksum: 62431a9e3875b8437fc76808bdfa964c (MD5) Previous issue date: 2014-04-02 / Studies related to the pursuit of a favorable environment for the production of medicinal plants with a focus on optimizing the synthesis of active substances are necessary in view of the economic and social importance of these species. This study aimed to evaluate the effect of quantitative and qualitative control of the spectrum of light transmitted through the shading nets on growth and essential oil production in plants of Melissa officinalis L. The experiment was conducted in Presidente Prudente / SP. Plants were potted and subjected to shading treatments offered by black net (retention of 50 %), Chromatinet ® red and blue shading nets (50 %) and full sun for a period of 120 days after transplanting (DAT) , in which two cuts were performed. It was determined the global solar radiation, the photosynthetic photon flux density, the chlorophyll content , the plants gas exchange, biometric and anatomical parameters and content and yield of essential oil in leaves . The experiment was performed in a completely randomized design with 4 treatments and 5 replications. Based on the results, it was found that despite melissa be considered as a plant with better development in shaded environments, this specie has adapted to the condition of full sun, in which the photosynthetic data were more significant , indicating no damage to the photosynthetic apparatus. However, the use of the blue net resulted in higher biomass production and essential oil content in plants, and therefore its utilization is indicated for Melissa production. No anatomical changes were observed as a result of the cultivation of Melissa under different quantity and quality of light. / Estudos relacionados à busca de um ambiente favorável de produção de plantas medicinais com foco na otimização da síntese de substâncias ativas se fazem necessários tendo em vista a importância econômica e social destas espécies. O presente trabalho teve o objetivo de avaliar o efeito do controle quantitativo e qualitativo do espectro de luz transmitidas através das malhas fotoconversoras sobre o crescimento e a produção de óleo essencial em plantas de Melissa officinalis L. O experimento foi conduzido em Presidente Prudente/SP. As plantas foram conduzidas em vasos e submetidas aos tratamentos de sombreamento proporcionados por malha preta de retenção de 50%, malhas fotoconversoras Chromatinet® vermelha (50%) e azul (50%) e pleno sol, por um período de 120 dias após o transplantio (DAT), no qual foram realizados dois cortes. Determinou-se a radiação solar global, a densidade de fluxo de fótons fotossintéticos, o índice de teor de clorofila, as trocas gasosas, os parâmetros biométricos e anatômicos e o teor e o rendimento de óleo essencial das folhas. O experimento foi conduzido seguindo delineamento inteiramente casualizado com 4 tratamentos e 5 repetições. Diante dos resultados obtidos, verificou-se que apesar da melissa ser considerada uma planta de com melhor desenvolvimento em meio sombreado, esta espécie se adaptou à condição de pleno sol, na qual os dados fotossintéticos foram mais expressivos, indicando a ausência de danos ao aparato fotossintético. No entanto, a utilização de malha azul resultou maior produção de biomassa e teor de óleo essencial nas plantas, sendo, portanto indicada sua utilização para o cultivo de melissa. Não foram observadas modificações anatômicas em decorrência do cultivo da melissa sob alteração da quantidade e qualidade da luz.

Made available in DSpace on 2015-03-26T13:36:41Z (GMT). No. of bitstreams: 1 texto completo.pdf: 1212166 bytes, checksum: 3f37e080ab7fd33c90b19c34980f54cb (MD5) Previous issue date: 2011-02-16 / Conselho Nacional de Desenvolvimento Científico e Tecnológico / The present study was carried out in order to analyse the contributions of hydraulic, diffusive (stomatal and mesophilic) and biochemical limitations to photosynthesis in coffee, the nitrogen partitioning within the photosynthetic machinery as well as its activation state in response to light. To this end, arabica coffee (Coffea arabica L.) plants were grown in pots during 12 months under two light availabilities (0 and 90% shading). Compared to sun plants, shade plants showed higher specific leaf area (63%), chlorophyll (76%), carotenoids (62%) and nitrogen (N) (15%) mass-based concentrations, as well as higher chlorophyll/N ratio (53%); in contrast, shade plants showed lower stomatal density (32%), stomatal index (20%), venation density (27%), stomatal (27%) and mesophyll (37%) conductance and N concentration on an area basis (30%). There were no differences in pigment concentrations (on an area basis) or in the chlorophyll a/b ratio between treatments. The N partitioning invested in Rubisco and electron transport chain components differed little between the phenotypes; however, higher N fraction was invested in structural components (13%) in shade plants compared to sun plants. There were no differences in mass-based gas exchange parameters except for the maximum carboxylation velocity calculated on a Cc basis, 24% higher in shade plants than in sun plants. In contrast, on an area basis, sun plants exhibited higher maximum carboxylation velocity (32%), maximum photosynthetic rate (45%) and electron transport rate (43%). Apparently, mesophyll conductance may be of equal or less importance than stomal conductance to explain the low photosynthetic rates in coffee, regardless of growth irradiance. It is suggested that the hydraulic architecture is the most limiting primary factor to photosynthesis in coffee plants. The results support the hypothesis that shade plants would take better advantage of sunflecks energy in relation to sun plants as a result of having higher activation states and lower induction losses, in addition to absence of photoinhibition in the shade leaves. The results help to explain, in part, the low photosynthetic nitrogen-use efficiency, as a consequence of high investment of N into non-photossynthetic components. / O presente estudo foi conduzido procurando-se analisar as contribuições das limitações hidráulicas, difusivas (estomática e mesofílica) e bioquímicas à fotossíntese do cafeeiro, a partição do nitrogênio dentro da maquinaria fotossintética e a ativação desta maquinaria em resposta à irradiância. Para tal, plantas de café arábica (Coffea arabica L.) foram cultivadas em vasos durante 12 meses, sob duas intensidades lumínicas (0 e 90% de sombreamento). Comparadas com as plantas de sol, as plantas à sombra exibiram maiores área foliar específica (63%), concentrações (em base de massa) de clorofilas (76%), carotenóides (62%) e de nitrogênio (N) (15%), como também maior razão clorofilas/N (53%); em contraste, as plantas sombreadas exibiram menores densidade estomática (32%), índice estomático (20%), densidade de venação (27%), condutâncias estomática (27%) e mesofílica (37%) e concentração de N em base de área (30%). Não houve variações significativas nas concentrações de pigmentos em base de área e na razão clorofila a/b entre os tratamentos. A partição do N investido em Rubisco e em componentes envolvidos no transporte de elétrons pouco diferiu entre os fenótipos; porém, maior fração do N investida em componentes estruturais (13%) foi observada nas plantas à sombra em relação às plantas ao sol. Não houve diferenças, em base de massa, nos parâmetros de trocas gasosas, com exceção da velocidade máxima de carboxilação tomando-se por base a concentração de CO2 nos sítios de carboxilação, 24% maior nas plantas sombreadas em relação às plantas a pleno sol. Em contraste, em base de área, as plantas de sol exibiram maiores velocidade máxima de carboxilação (32%), taxa fotossintética máxima (45%) e taxa de transporte de elétrons (43%). Aparentemente, a condutância mesofílica tem importância igual ou inferior à da condutância estomática na explicação das baixas taxas fotossintéticas, independentemente da irradiância de crescimento. Sugere-se que a arquitetura hidráulica seja o fator primário mais limitante à fotossíntese no cafeeiro. Os resultados suportam a hipótese de que as plantas sombreadas aproveitariam melhor a energia de sunflecks em relação às plantas de sol, em razão dos maiores estados de ativação e menores perdas de indução fotossintética, além de ausência de fotoinibição nas folhas de sombra. Os resultados ajudam a explicar, em parte, a baixa eficiência fotossintética do uso do N, em decorrência de alto investimento desse elemento em compostos não-fotossintéticos.

The regeneration in oak-dominated stands following five silvicultural treatments was examined on four sites in the mountains of Virginia and West Virginia. Treatments included: silvicultural clearcut, leave-tree, commercial clearcut, shelterwood, and group selection. The effects of harvesting were compared among sites and among treatments. Oak regeneration dominance, measured by the relative density of dominant and codominant oak regeneration, was the most important variable calculated from the data. Oak regeneration dominance varied by site, but did not vary by silvicultural treatment; all treatments resulted in relatively low numbers. Therefore, the silvicultural treatments used here were not enough to overcome the site specific limitations to successful oak regeneration. Oak species also seemed to be less important in the regenerating stands than in their parent stands. The biggest losses in oak importance occurred on the intermediate and high quality sites; competitive oak regeneration was relatively scarce on two of the three sites with an oak site index (base age 50) of over 70 ft. Multiple linear regression analysis was used to identify the factors controlling oak regeneration at a smaller scale. The most important variables were those that described the oak stump sprouting potential, the understory and overstory oak component in the pre-harvest stand, post-harvest light and soil nitrogen levels. / Master of Science

This master’s thesis deals with establishment of parameters of the PPI filter material using methods of image analysis. The first part is aimed at general methods used in practice, an overview of splitting into filter clasification and characterization of the PPI filter material. The second part represents an introduction to problems of machine vision. There are outlined basic methods of image processing. Last parts of the thesis study the method using detection of bright light levels. The measurement and interpretation of results is performed with the PPI material - types 10/6 and 10/12. For image processing is used the MATLAB program, version 7.0.1.