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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.
1

Study on biochemical characteristics of hemocyanins in mud crab Scylla olivacea

Chen, Hong-Yu 10 August 2006 (has links)
Hemocyanin, a copper containing protein, is the respiratory protein of Crustacea. Here, 4 major hemocyanin molecules in the hemolymph of Scylla olivacea were purified and studied. Both two-hexamer (24S) and hexamer (16S) form of hemocyanin are present in all adult¡¦s hemolymph. In vitro, 24S hemocyanin dissociates into two 16S hemocyanin in the absence of calcium under high pH value (> 8.9). Little of 16S hemocyanin assembles spontaneously into 24S hemocyanin after calcium is added. Both 16S and 24S hemocyanins were purified from hemolymph, the 16S hemocyanin differs from the 24S hemocyanin in the presence of intersubunit disulfide bonds, it is inferred that not all native 16S hemocyanin dissociates from 24S hemocyanin. Besides the 24S and 16S hemocyanin, there are two massive proteins in the hemolymph of ovary-maturing female S. olivacea. One is female-specific hemocyanin (FSH), which occurs in the hemolymph of ovary-maturing females, but not in the hemolymph of juveniles of either sex or in adult males. FSH is confirmed as a hemocyanin due to its copper content and oxygen binding ability. FSH is also found in ovary, embryo and early-stage zoea, and is proposed to be an important hemocyanin that supplies enough oxygen for ovary-maturing female crab, egg, embryo and early-stage zoea. Another massive hemolymph protein is a non-respiratory protein (NRP) that is present in hemolymph of adults of both sex, the molecular mass of its subunits is similar to hemocyanin and FSH, and one of subunits can be slightly recognized by anti-FSH antibody. NRP is not a respiratory protein, there is neither copper containing nor absorbance of 340nm. FSH and NRP, especially NRP, contain more carbohydrates than the 16S hemocyanin.
2

Ecologia e Conservação de Tartarugas Marinhas Através da Análise de Encalhes no Litoral Paraibano

Poli, Camila 28 July 2011 (has links)
Made available in DSpace on 2015-04-17T14:55:19Z (GMT). No. of bitstreams: 1 arquivototal.pdf: 691952 bytes, checksum: aa37d23f6ffbb0e86e790fa6ad93ee28 (MD5) Previous issue date: 2011-07-28 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / Five sea turtle species use the Brazilian coast for reproduction and feeding: loggerhead turtle (Caretta caretta), green turtle (Chelonia mydas), leatherback turtle (Dermochelys coriacea), olive turtle (Lepidochelys olivacea) and hawksbill turtle (Eretmochelys imbricata). These species are included in the threatened categories, as much globally, according to the Red List of Threatened Species, issued by the International Union for Conservation of Nature (IUCN), as regionally, according to the Livro Vermelho da Fauna Brasileira Ameaçada de Extinção, published by the Ministério do Meio Ambiente. Sea turtles naturally face a wide variety of stressors, both natural and anthropogenic, like diseases, predation by other animals, incidental capture in fishing artifacts, marine pollution and the hunt. Systematic data collection from stranded sea turtles can provide useful biological information, such as seasonal and spatial patterns in their occurrence, and mortality, age structure, sex ratio, diet, interannual variations associated with climatic or anthropogenic events, as well as possible mortality causes. Thus, this study aimed to examine sea turtle strandings on the coast of Paraíba State, from August 2009 to July 2010, emphasizing the observation of the occurrence of ingestion of anthropogenic debris. In this period, 124 strandings were recorded. The species observed were C. mydas (n = 106), E. imbricata (n = 15), L. olivacea (n = 2) and C. caretta (n = 1). Of the total strandings that could be measured (n = 122), only twelve individuals (9.7%) could be considered adults. In 20 individuals, synthetic anthropogenic debris were found inside the gastrointestinal tract and of these, in 13 individuals it was concluded that the death cause was the ingestion of these residues. In 43 individuals, other traces of human interactions were observed, such as injuries caused by entanglement in fishing lines or nets, collisions with vessels, direct contact with oil spills, and lesions caused by knives and harpoons. In 28.5% of the stranded turtles, the presence of external tumors was noted, suggestive of fibropapillomatosis. Moreover, in 9.7%, shark bite marks were observed. A significant difference was found in the occurrence of strandings between males and females, being that the females were more frequent. Also, a significant difference was found in the occurrence of strandings between the different seasons, being that in the spring/summer (dry season), the strandings were more frequent. The most worrying result of this study was the observation of human interactions in half of the strandings analyzed. Stranding monitoring is necessary along the whole coast of Brazil and, indeed, along those of the entire world, because it has a fundamental role in studies of the ecology, biology and conservation of these species, generating benefits for local action, directed to the major problems observed. / Cinco espécies de tartarugas marinhas utilizam a costa brasileira para reprodução e alimentação: a tartaruga cabeçuda (Caretta caretta), a tartaruga verde (Chelonia mydas), a tartaruga de couro (Dermochelys coriacea), a tartaruga oliva (Lepidochelys olivacea) e a tartaruga de pente (Eretmochelys imbricata). Estas espécies estão incluídas em categorias de ameaça, tanto mundialmente, de acordo com a lista vermelha de animais ameaçados de extinção da União Internacional para a Conservação da Natureza (IUCN), como regionalmente, de acordo com o Livro Vermelho da Fauna Brasileira Ameaçada de Extinção, do Ministério do Meio Ambiente. As tartarugas marinhas, naturalmente, encontram uma ampla variedade de estressores, tanto naturais quanto antrópicos, como doenças, predação por outros animais, captura incidental em artefatos de pesca, poluição marinha e a caça. A coleta sistemática de dados de tartarugas marinhas encalhadas pode fornecer informação biológica útil, como por exemplo, padrões sazonais e espaciais na ocorrência e mortalidade, estrutura etária, proporção sexual, dieta, variações interanuais associadas a eventos climáticos ou antropogênicos bem como as possíveis causas de mortalidade. O objetivo deste trabalho foi analisar os encalhes de tartarugas marinhas na costa do estado da Paraíba, no período de agosto de 2009 a julho de 2010, enfatizando a observação da ocorrência de ingestão de material antropogênico. Neste período foram registrados 124 encalhes. As espécies observadas foram C. mydas (n = 106), E. imbricata (n = 15), L. olivacea (n = 2) e C. caretta (n = 1). Do total de encalhes que puderam ser mensurados (n = 122), apenas doze indivíduos (9,7%) puderam ser considerados adultos. Em 20 indivíduos, foram encontrados resíduos antropogênicos sintéticos dentro do trato gastrointestinal e destes, em 13 indivíduos foi possível concluir que a causa da morte foi a ingestão destes resíduos. Em 43 indivíduos foram observados outros vestígios de interações humanas, como ferimentos provocados por emaranhamentos em linhas ou redes, ferimentos provocados por colisões com embarcações, contato direto com manchas de óleo e ferimentos provocados por facas e arpões. Em 28,5% das tartarugas encalhadas notou-se a presença de tumores externos sugestivos de fibropapilomatose. Em 9,7% foi possível observar marcas de mordidas de tubarões. Observou-se uma diferença significativa na ocorrência de encalhes entre machos e fêmeas, sendo que as fêmeas foram mais frequentes. Também verificou-se uma diferença significativa na ocorrência de encalhes entre as diferentes estações, sendo que no período de primavera/verão (estação seca) os encalhes foram mais frequentes. O resultado mais preocupante deste estudo foi a observação de evidências de interação com atividades antrópicas em metade dos encalhes analisados. O monitoramento de encalhes se faz necessário em toda a costa do Brasil e do mundo, pois este tem papel fundamental em estudos de ecologia, biologia e conservação destas espécies, gerando assim subsídios para ações locais e direcionadas aos principais problemas observados.
3

FORAGING ECOLOGY OF NESTING GREEN, OLIVE RIDLEY, AND LEATHERBACK TURTLES FROM NORTHWEST COSTA RICA

Alison Jenele Meeth (10716291) 28 April 2021 (has links)
<div>Understanding what sea turtles are feeding on and where they are feeding is key to understand their overall biology and will aid in understanding what type of management actions are necessary in order to conserve and protect these endangered species. Here I set out to (1) examine the population-level isotopic profiles of three sea turtle species in the Eastern Tropical Pacific; (2) determine differences in their foraging strategies; (3) attempt to gain insights about their pre-nesting origins; and (4) determine whether body size would influence the isotopic values of an individual turtle.</div><div>Stable isotope analysis (δ<sup>13</sup>C and δ<sup>15</sup>N values) was conducted on tissue samples from 52 sea turtles nesting on Playa Cabuyal, Costa Rica; 28 Pacific green (<i>Chelonia mydas</i>), 20 olive ridley (<i>Lepidochelys olivacea</i>), and 4 leatherback (<i>Dermochelys coriacea</i>). Nine satellite transmitters were also deployed on a separate population of post-nesting Pacific green turtles from Playa Cabuyal.</div><div>Based on isotopic profiles, green turtles in the Eastern Tropical Pacific were found to be feeding at a higher trophic level when compared to green turtles in other regions and this was supported by their increased δ<sup>15</sup>N values (16 ± 0.8 ‰). Rather than shifting to herbivory as adults, green turtles foraging in the eastern Pacific are potentially remaining omnivorous. Tracking data further confirmed that green turtles are coastal migrators and are probably inhabiting areas with high δ<sup>15</sup>N values within this region. Olive ridley turtles are exhibiting similar behavior to olive ridley turtles elsewhere due to minimal variance in their isotopic profiles (δ<sup>13</sup>C = -15.1 ± 0.7 ‰, δ<sup>15</sup>N =14.2 ± 0.8 ‰) and their known nomadic behavior. Although a small sample size, leatherback turtles showed a shift in their foraging habitats suggesting they are also feeding inshore in addition to their pelagic behavior due to their increased δ<sup>13</sup>C values (-15.5 ± 0.4 ‰). Further, as body size increased in olive ridley’s, the δ<sup>15</sup>N values significantly decreased suggesting that larger turtles prefer deeper pelagic waters with less enriched N isotope concentrations. However, in order to rule out possible external factors influencing this relationship, knowing where the turtle is originating from is crucial. This project provides data for developing isoscapes in the Eastern Tropical Pacific to aid in understanding the spatial distribution of sea turtles and their foraging grounds and the impact that foraging area may have on overall biology of these species. This information can be used to prioritize high use foraging habitats and determine the most effective management practices for protecting these species and the prey and habitat on which they rely.</div>
4

Studies on the epidemiology of black-foot disease of grapevine in Spain

Agustí Brisach, Carlos 12 March 2013 (has links)
Las enfermedades de la madera se encuentran entre las patologías más dañinas que afectan al cultivo de la vid. El pie negro es una de las más destacadas, afectando a las plantas en vivero y en plantaciones jóvenes. Los agentes causales están incluidos dentro de los géneros Campylocarpon, ¿Cylindrocarpon¿, Cylindrocladiella e Ilyonectria. Éstos se caracterizan por ser habitantes del suelo y, se ha demostrado que permanecen en él, infectando al material de propagación cultivado en campos de vivero. La presencia de hongos asociados al pie negro en vivero, así como sus fuentes potenciales de inóculo en suelos de vivero y de viñedos comerciales, no han sido nunca estudiados en España. En este sentido, el objetivo de esta Tesis ha sido estudiar la epidemiología de hongos que causan el pie negro de la vid en España. En primer lugar, las distintas fases del proceso viverístico se evaluaron como fuentes potenciales de inóculo de estos patógenos. Se tomaron muestras en cuatro fases del proceso de propagación de las que se extrajo el ADN, detectándose las especies causantes del pie negro de la vid mediante multiplex, nested PCR. En las fases estudiadas se detectaron I. liriodendri y el complejo I. macrodidyma. También se estudió la detección de especies de Ilyonectria en material de propagación de vid, antes y después de la fase de enraizamiento en campos de vivero, mediante técnicas de aislamiento y multiplex, nested PCR. Este estudio confirmó que el número de plantas infectadas con estos patógenos aumenta durante el proceso de enraizamiento en campos de vivero. Ilyonectria torresensis fue la única especie aislada de las plantas tras la inducción del callo. Sin embargo, las especies I. liriodendri, I. novozelandica e I. torresensis se aislaron frecuentemente tras el período de cultivo en campos de vivero. Respecto a la detección molecular, se detectaron un número elevado de muestras positivas en planta tras la inducción del callo y después del proceso de enraizamiento. Mediante el uso de cuatro técnicas diferentes, aislamiento fúngico a partir de raíces de plántulas de vid utilizadas como plantas trampa, aislamiento a partir de raíces de malas hierbas, multiplex, nested PCR y qPCR, se estudió el suelo de campos de plantas madre como fuente de inóculo de estos patógenos. De las raíces de plantas trampa se aislaron las especies I. alcacerensis, I. macrodidyma, I. novozelandica e I. torresensis. ¿Cylindrocarpon¿ macrodidymum fue la única especie aislada de las raíces de malas hierbas. En los análisis de suelos realizados mediante multiplex, nested PCR así como mediante qPCR se observó un elevado porcentaje de detección del complejo I. macrodidyma en muestras de ADN de suelo, mientras que el porcentaje de detección de I. liriodendri fue menor. Las mismas técnicas descritas para campos de plantas madre se utilizaron para estudiar los suelos de campos de vivero y de viñedos comerciales. Los resultados obtenidos en estos dos tipos de campos fueron similares a los obtenidos en campos de plantas madre. Finalmente, se estudió el efecto de la temperatura, pH y potencial osmótico (¿s) sobre el crecimiento miceliar, la esporulación y la producción de clamidosporas de ¿C.¿ liriodendri, ¿C.¿ macrodidymum y ¿C.¿ pauciseptatum, con el objetivo de mejorar el conocimiento de los factores que afectan al crecimiento, reproducción y supervivencia de estos patógenos. Todos los aislados estudiados crecieron en un rango de temperaturas comprendido entre 5 y 30ºC. Se observó crecimiento miceliar en un rango de pH comprendido entre 4 y 8. Respecto al efecto del ¿s, el crecimiento miceliar fue mejor en medio de cultivo PDA ajustado a -0,5, -1,0 y/o -2,0 MPa en comparación con el crecimiento miceliar observado en PDA sin ajustar a ningún ¿s (-0,3 MPA). La mayoría de los aislados de ¿Cylindrocarpon¿ esporularon a todas las temperaturas, pHs y valores de ¿s estudiados. En general, la producción de clamidosporas no se vio afectada por la temperatura, el pH y el ¿s. / Agustí Brisach, C. (2013). Studies on the epidemiology of black-foot disease of grapevine in Spain [Tesis doctoral]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/27598
5

DEPREDATION OF OLIVE RIDLEY AND LOGGERHEAD TURTLE CLUTCHES ON BEACHES WITH AND WITHOUT PREDATOR MANAGEMNT

Carlynn Nicole Cornhill (11002167) 23 July 2021 (has links)
<p>Management of predation on sea turtle nesting beaches is vital to conservation efforts for the vulnerable loggerhead turtles (<i>Caretta caretta</i>) and olive ridley turtles (<i>Lepidochelys olivacea</i>). Sea turtles increasingly face threats from invasive and human-tolerant mammalian predators as human disturbances on nesting beaches rises. The intensity of mammalian predation has increased in Las Baulas National Park in Costa Rica which is an important nesting site for several species of threatened and endangered sea turtles. I analyzed loggerhead and olive ridley nest predation on four beaches in the United States and Costa Rica that were chosen for variations in degree of human disturbance and management strategies. My objectives were to 1) determine if egg predation rates differ at the four sites, 2) determine the most destructive predators at each location, and 3) suggest management options to alleviate mammalian threats to turtle clutches on Playa Grande and Playa Cabuyal in Costa Rica. My results show that the beaches without a nest protection or predator control program had very high rates of predation. Invasive mammalian predators and mammalian predators associated with human disturbance were the most destructive at the four sites. I recommend that regulations regarding dogs and the take of eggs from the beach are enforced at Playa Cabuyal and that physical nest protection is rapidly implemented at Playa Grande. I also recommend that the National Park consider managing raccoon predation by removing problem individuals, but caution that they do so in a way that maintains the animals’ role in the ecosystem.</p>

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