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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

The lamellar structure of the shell of Patella crenata a crystallographic study /

Pramatarova, Radina. January 2003 (has links) (PDF)
Hamburg, University, Diss., 2003.
2

Neuroendocrine control of water balance in the decapod crustacean, Thalamita crenata / Water balance in the decapod crustacean, Thalamita crenata

Tullis, Richard E January 1972 (has links)
Typescript. / Bibliography: leaves [65]-70. / vii, 70 l illus., tables
3

Criteria signaling reapplication of controlled-release fertilizer for maximum growth of Ilex crenata Thunb. 'Helleri' /

Shiflett, Melinda Cole, January 1992 (has links)
Thesis (M.S.)--Virginia Polytechnic Institute and State University, 1992. / Vita. Abstract. Includes bibliographical references (leaves 19-20). Also available via the Internet.
4

Phosphorus nutrition of Ilex crenata 'Helleri' grown in a pine bark medium

Yeager, Thomas H. January 1981 (has links)
The purpose of this research was to characterize the phosphorus nutrition of Ilex crenata 'Helleri' and pine bark P relationships. Branched liners of 'Helleri' holly were grown in a pine bark medium in which 0, 5, 10, 15, 20, 25, or 30 ppm P were maintained. Shoot dry weight increased as the pine bark P level increased to 10 ppm P, while root dry weight decreased with increasing pine bark P levels. Total mg of P in shoot tissues continued to increase with P treatments higher than 10 ppm, indicating luxury consumption of P. Total mg of P in root tissues increased to the 10 ppm P treatment. Total µg of Fe, Cu, and Zn in shoot tissues followed the dry weight response, increasing to the 5-10 ppm P treatment then tending to decrease as pine bark P levels increased. Root tissue Fe was erratic while Cu did not vary with treatment and Zn decreased with increasing pine bark P levels. Total µg of Mn in shoot tissues increased with P treatments while total µg of Mn in root tissues decreased with increasing pine bark P levels. Dry shoot weights of 'Helleri' holly grown in a pine bark medium amended with either 270, 540, or 810 g/m³ of P or fertilized with 10 ppm P were not different while root dry weights decreased with increasing pine bark P levels. Water extractable P for the 810 g/m³ treatment decreased 245 ppm during the experiment and by week 5 was below 10 ppm. Amending the pine bark medium with 270 g/m³ of P did not increase the dry shoot weight of ‘Helleri’ holly when subsequently fertilized with a complete slow-release granular or water soluble fertilizer. The pine bark medium contained indigenous P which leached rapidly. When ‘Helleri’ holly were fertilized with a nutrient solution without P, 0.08 mg of indigenous P were absorbed. The pine bark adsorbed 7.5 µg of P per g of pine bark when equilibrated with a 10 ppm P nutrient solution. These studies indicate that maintaining 10 ppm P in the pine bark medium results in the greatest dry weight of 'Helleri' holly. A stable pine bark P level was not attained with superphosphate-amended pine bark, thus superphosphate is not recommended as a P source. Pine bark P relationships revealed that ‘Helleri’ holly absorbed indigenous P while a negligible amount of P was bound by the pine bark compared to the amount of P used by a ‘Helleri’ holly grown in a 1 liter container. / Ph. D.
5

Criteria signaling reapplication of controlled-release fertilizer for maximum growth of Ilex crenata Thunb. 'Helleri'

Shiflett, Melinda Cole 12 September 2009 (has links)
Medium solution N and electrical conductivity (EC), and foliar N levels were measured to determine criteria which signal the need for reapplication of a controlled-release fertilizer (CRF) in order to maximize growth of container-grown Ilex crenata Thunb. ‘Helleri’. Rooted cuttings of ‘Helleri’ holly were initially fertilized (7 Mar. 1991) with 8-9 month (18N-2.6P-9.9K) or 12-14 month (17N-3.1P-9.9K) Osmocote. A subset of 12 plants received a CRF reapplication (half rate) of the respective Osmocote formulation on 19 July, 2 Aug., or 16 Aug. In addition to reapplication treatments, 12 plants received a liquid fertilizer (LF) solution with each irrigation starting on 19 July. Canopy widths of plants receiving LF or CRF reapplication on 19 July and 2 Aug. were greater than those plants without supplemental fertilizer (control). At the time of the second reapplication date (2 Aug.), medium solution N and EC, and foliar N levels of control plants were = 40 mg liter⁻¹, 0.4 d m⁻¹ and 2.3%, respectively. Since growth of control plants was less than those of LF, CRF 19 July and 2 Aug. reapplications, medium solution N and EC, and foliar N values at the time of the second reapplication (2 Aug.) signaled the need for CRF reapplication or LF supplementation. There was a strong relationship between medium solution EC and N (NO₃ + NH₄) (r² = 0.91, P = 0.05), indicating that growers could use EC measurements to predict medium solution N concentration, as well as to assess the adequacy of the fertilizer regime. / Master of Science
6

First Responders to Cataclysmic Upheaval: Earthquake–Driven Effects on Microalgae in the Avon-Heathcote Estuary, Christchurch, New Zealand.

Hutt, Shevelle Dionne January 2013 (has links)
The Avon-Heathcote Estuary is of significant value to Christchurch due to its high productivity, biotic diversity, proximity to the city, and its cultural, recreational and aesthetic qualities. Nonetheless, it has been subjected to decades of degradation from sewage wastewater discharges and encroaching urban development. The result was a eutrophied estuary, high in nitrogen, affected by large blooms of nuisance macroalgae and covered by degraded sediments. In March 2010, treated wastewater was diverted from the estuary to a site 3 km offshore. This quickly reduced water nitrogen by 90% within the estuary and, within months, there was reduced production of macroalgae. However, a series of earthquakes beginning in September 2010 brought massive changes: tilting of the estuary, changes in channels and water flow, and a huge influx of liquefied sediments that covered up to 65% of the estuary floor. Water nitrogen increased due to damage to sewage infrastructure and the diversion pipeline being turned off. Together, these drastically altered the estuarine ecosystem. My study involves three laboratory and five in situ experiments that investigate the base of the food chain and responses of benthic microalgae to earthquake-driven sediment and nutrient changes. It was predicted that the new sediments would be coarser and less contaminated with organic matter and nutrients than the old sediments, would have decreased microalgal biomass, and would prevent invertebrate grazing and bioturbation activities. It was believed that microalgal biomass would become similar across new and old sediments types as the unstable new sediments were resuspended and distributed over the old sediments. Contact cores of the sediment were taken at three sites, across a eutrophication gradient, monthly from September 2011 to March 2012. Extracted chlorophyll a pigments showed that microalgal biomass was generally lower on new liquefied sediments compared to old sediments, although there was considerable site to site variation, with the highly eutrophic sites being the most affected by the emergence of the new sediments. Grazer experiments showed that invertebrates had both positive and negative site-specific effects on microalgal biomass depending on their identity. At one site, new sediments facilitated grazing by Amphibola crenata, whereas at another site, new sediments did not alter the direct and indirect effects of invertebrates (Nicon aestuariensis, Macropthalmus hirtipes, and A. crenata) on microalgae. From nutrient addition experiments it was clear that benthic microalgae were able to use nutrients from within both old and new sediments equally. This implied that microalgae were reducing legacy nutrients in both sediments, and that they are an important buffer against eutrophication. Therefore, in tandem with the wastewater diversion, they could underpin much of the recovery of the estuary. Overall, the new sediments were less favourable for benthic microalgal growth and recolonisation, but were less contaminated than old sediments at highly eutrophic sites. Because the new sediments were less contaminated than the old sediments, they could help return the estuary to a noneutrophic state. However, if the new sediments, which are less favourable for microalgal growth, disperse over the old sediments at highly eutrophic sites, they could become contaminated and interfere with estuarine recovery. Therefore, recovery of microalgal communities and the estuary was expected to be generally long, but variable and site-specific, with the least eutrophic sites recovering quickly, and the most eutrophic sites taking years to return to a pre-earthquake and non-eutrophied state. changes in channels and water flow, and a huge influx of liquefied sediments that covered up to 65% of the estuary floor. Water nitrogen increased due to damage to sewage infrastructure and the diversion pipeline being turned off. Together, these drastically altered the estuarine ecosystem. My study involves three laboratory and five in situ experiments that investigate the base of the food chain and responses of benthic microalgae to earthquake-driven sedimen tand nutrient changes. It was predicted that the new sediments would be coarser and less contaminated with organic matter and nutrients than the old sediments, would have decreased microalgal biomass, and would prevent invertebrate grazing and bioturbation activities. It was believed that microalgal biomass would become similar across new and old sediments types as the unstable new sediments were resuspended and distributed over the old sediments. Contact cores of the sediment were taken at three sites, across a eutrophication gradient, monthly from September 2011 to March 2012. Extracted chlorophyll a pigments showed that microalgal biomass was generally lower on new liquefied sediments compared to old sediments, although there was considerable site to site variation, with the highly eutrophic sites being the most affected by the emergence of the new sediments. Grazer experiments showed that invertebrates had both positive and negative site-specific effects on microalgal biomass depending on their identity. At one site, new sediments facilitated grazing by Amphibola crenata, whereas at another site, new sediments did not alter the direct and indirect effects of invertebrates (Nicon aestuariensis, Macropthalmus hirtipes, and A. crenata) on microalgae. From nutrient addition experiments it was clear that benthic microalgae were able to use nutrients from within both old and new sediments equally. This implied that microalgae were reducing legacy nutrients in both sediments, and that they are
7

Study on larval culture and metamorphosis of portunid crab, Thalamita creanata

Hsieh, Wen-jui 09 November 2012 (has links)
The combination of two factors, temperature and salinity might affect zoeal survival and morphological pattern of Thalamita crenata. In order to know the effect, newly hatched zoeae were reared under 45 combinations of temperature and salinity (i.e. combinations of five temperatures variables: 20, 25, 30, 33, 35¢J and nine salinity variables: 18,20,22,25,30,35,38,40,42 psu ). The zoeae were fed with newly hatched Artemia nauplii. The results showed that temperature and salinity as well as the interaction of the two parameters significantly affected the survival rate of zoeae. The effect of temperature at 20¢J and 35¢J resulted in no zoeal survival from zoea to megalopa stage. Under the temperature range of 25~33¢J, There is significant difference between the survival rates of zoeae (p < 0.05). High survival rate (above 64%) occurred at temperature range of 25~30¢J and salinity range of 30~35 psu. Survival rate decreased at salinity range of 20,22,25,38 psu. Under 30¢J and 18 psu condition, zoeae could develop into megalopa stage. Temperature, salinity and their interaction also significantly affected zoeal development. At 25¢J, the shortest zoeal developmental time to reach megalopa was 18 days under salinity 30 and 35 psu conditions and the developmental time extended to 20 and 21 days under salinity 38 and 20 psu conditions. At 30¢J, the shortest zoeal developmental time to reach megalopa was 11 days under salinity 30 psu conditions and the developmental time extended to 23 days under salinity 18 psu conditions. Under 33¢J and 25 psu condition, the zoeal developmental time to reach megalopa ranged from 16 to 22 days. The larval development of Thalamita crenata has five zoeal stages. Four tested zoeae had morphological differences in antennules, maxillule and maxilla in fifth stage which are shown as follow. There are 5 additional setae on the top of antennule exopod . The endite of maxillule coxal has 14 plumose setae; The basal endite has 8 plumose setae. The maxilla basal endite has 8 plumose setae. The scaphognathite has 27 plumose setae. In addition to basic five zoeal stages, an additional zoeal stages was observed from the tested crab. There were evidences suggested that the appearance of the additional zoeae was associated with limited temperature condition for life and lower salinity. Based on exuviae and larval specimens, the major morphological characteristics of the additional zoeal larvae were as follow: oblong carapace, lateral spine disappeared; prolonged cheliped and pereiopods compared to Z5 stage; with setae on pleopods.
8

Avaliação da atividade antinociceptiva e antiinflamatória do óleo essencial de Hyptis crenata (Pohl) ex Benth / Evaluation of the antinociceptiva and antiinflammatory activity of the essential oil of Hyptis crenata (Pohl) former Benth

BRAVIM, Luciana Silva 07 November 2008 (has links)
Made available in DSpace on 2011-03-23T21:19:37Z (GMT). No. of bitstreams: 0 / Item created via OAI harvest from source: http://www.bdtd.ufpa.br/tde_oai/oai2.php on 2011-03-23T21:19:37Z (GMT). Item's OAI Record identifier: oai:bdtd.ufpa.br:274 / Hyptis crenata (Pohl) ex Benth. is a herbaceous aromatic and medicinal plant, belongs to Lamiaceae, popularly known as salva-do-marajó, malva-do-marajó and hortelã-bravo. This plant is distributed since the mouth of Amazonas River, Marajó Island, Pantanal, and extending up to the states of Minas Gerais. Its essential oil is characterized by presence of monoterpenes and sesquiterpenes. The leaf tea is used as sudorific, tonic, stimulant, as well as to treat the eyes and throat inflammation, constipation and arthritis. Based in these information, we decided to evaluate the antinociceptive and anti-inflammatory activity of the oil (HcEO) of Hyptis crenata in mouse throught the following tests: abdominal constriction, hot plate, formalin, croton oil-induced ear edema, rat paw edema induced by dextran and carrageenan, carrageenan-induced peritonitis. The statistical method used in this study was ANOVA followed by multiple comparison (Student-Newman-Keuls test or Student t test). The essential oil was extracted by hydrodistillation, yield was 0,6% and their main components were monoterpenes (94,5%). The lethal dose (DL50) was 5000 mg/kg. In the abdominal constriction test, at doses of 250, 350 and 500 mg/kg, the HcEO inhibited the abdominal constrictions in 22,56%, 60,76% and 75,53%, respectively, in a dose-dependent manner when compared to the control group. The DE50 calculated was 364,22 mg/kg with a correlation coefficient of 0,9341. The oil not changed significantly the time of latency in the hot plate test. HcEO (364,22 mg/kg) caused an inhibition of the phase I in 26,42% and an inhibition of the phase II in 43,86% of the formalin test. Naloxone, an antagonist of opioid receptor, reverted the analgesic effect of EOHc. HcEO reduced croton oil-induced ear edema in 44,26%. In rat paw edema induced by dextran, HcEO produced inhibition at the dose of 364,22 mg/kg, but the rat paw edema induced by carrageenan this inhibition was not observed. In carrageenan-induced peritonitis, HcEo significantly decreased the leucocyte and neutrophil migration in 47,55% e 66,47%, respectively. Based on the results we are suggesting that the essential oil of H. crenata has an antinociceptive activity.It is probably as consequence of direct action on the nociceptive fiber, as well as the opioid system is involved in this effect. Further, our results suggest that anti-inflammatory activity of HcEO is probably of peripheral origin. It can be suggested, too, that the possible components responsible for these actions are the compounds monoterpenes presents in HcEO. / Hyptis crenata (Pohl) ex Benth. é uma planta herbácea, medicinal e aromática, pertencente à família lamiaceae, conhecida popularmente como salva-do-marajó, malva-do-marajó e hortelã-bravo. Distribui-se no estuário do Rio Amazonas, Pantanal e no estado de Minas-Gerais. Seu óleo essencial é caracterizado pela presença de monoterpenos e sesquiterpenos. É utilizada popularmente como sudorífico, tônico, estimulante, bem como para tratar inflamação de olhos e garganta, constipação e artrite. Baseado nessas informações, decidiu-se avaliar a atividade antinociceptiva e antiinflamatória do óleo essencial desta espécie (OEHc) através dos seguintes testes: teste das contorções abdominais induzidas por ácido acético, placa quente, formalina, dermatite induzida pelo óleo de croton, edemas induzidos por dextrana e carragenina e peritonite induzida por carragenina. Para a análise estatística utilizou-se ANOVA seguida de um método de múltiplas comparações (Teste de Student-Newman-Keuls ou teste "t" de Student). O óleo foi extraído por hidrodestilação, obtendo um rendimento de 0,6%. É composto predominantemente por monoterpenos (94,5%). A dose letal media DL50 foi de 5000 mg/kg. Nas contorções abdominais induzidas por ácido acético o óleo (250, 350 e 500 mg/kg) reduziu de forma significante de maneira dose-dependente estas contorções em 22,56%, 60,76% e 75,53%, respectivamente, cujo coeficiente de correlação linear foi de r = 0,9341 e DE50 = 364,22 mg/kg. No teste da placa quente, o óleo não foi capaz de aumentar o tempo de latência de maneira significante. No teste da formalina, o OEHc produziu uma inibição da 1 fase em 26,49% e da 2 fase em 43,39%. Além disso, a naloxona reverteu o efeito do OEHc neste teste. Na dermatite induzida pelo óleo de croton, o OEHc reduziu o edema de maneira significante em 44,26%. No edema induzido por dextrana, o óleo foi capaz de impedir o desenvolvimento do edema na dose de 364,22 mg/kg de maneira significante em relação ao grupo controle. Porém, no edema induzido por carragenina esta inibição não foi observada. Na peritonite induzida por carragenina, o OEHc reduziu o número de leucócitos e o de neutrófilos em 47,55% e 66,47%, respectivamente. A partir dos resultados obtidos, sugere-se que o OEHc apresenta atividade antinociceptiva provavelmente através da ação direta sobre as fibras nociceptivas, além de sugerir que os receptores opióides possam estar envolvidos neste processo; e atividade antiinflamatória provavelmente de origem periférica. Pode-se sugerir, também, que os possíveis componentes responsáveis por essas ações sejam os compostos monoterpênicos presentes no OEHc.

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