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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.
11

Effect of EPA on Intercellular Lipid Droplets Degradation

Amir Alipour, Mohsen January 2017 (has links)
Although the beneficial effects of omega-3 fatty acid in reducing the risk of various of human diseases, such as hypertriglyceridemia and nonalcoholic fatty liver disease, have been demonstrated in clinical and pre-clinical studies, the mechanism of its action is poorly understood. several studies has been reported that Dietary supplementation with fish oil induces many changes in plasma TG profile. N-3 fatty acid found in fish oil has been reported that reduce plasma TG and VLDL lev- els. Intercellular lipid droplets is the key regulator of plasma fatty acids and lipoproteins level. Here we show that n-3 fatty acid supplementation triggers intercellular lipid droplets degradation independent from known fatty acid mobilization pathways namely lipophagy and lipolysis . ATGL and HSL are consider as two major lipolysis enzymes.SiRNA study of these two lipolysis enzymes did not attenuate lipid droplets degradation. Lipophagy has been reported as a selective mechanism for degradation of lipid droplets during the starvation condition. Knock down of autophagy (macroautophagy) related pro- teins, could not block degradation of intercellular lipids by EPA. Degradation of lipid droplets is lysosomes dependent and requires lysosomal motility machinery. Lysosomes are interacting directly with lipid droplets during the process that is similar to kiss and run pattern. The morphological examination of this process by electron microscopy indicated its re- semblance to microautophagy like structure. Importantly, (over expression) Arl8b which has been shown that play a role in peripheral distribution of lysosomes along with FYCO1, specifically accelerates the effect of EPA on degradation of intercellular lipid droplets independent from its role in engagement of lysosomal plus end distribution. in particular, Arl8b recruited HOPS protein complex in EPA dependent fashion and si- lencing of HOPS complex interfered with normal lysosomal degradation of lipid droplets. Thus, this finding reveals new mechanism for intercellular lipid mobilization and offer an explanation for the therapeutic benefits of omega-3 fatty acids.
12

Steelhead trout otoliths for age, race, and stock analysis /

McKern, John L. January 1971 (has links)
Thesis (M.S.)--Oregon State University, 1971. / Typescript (photocopy). Includes bibliographical references. Also available via the World Wide Web.
13

Movement of tagged lingcod and rockfishes off Depoe Bay, Oregon /

DeMott, Glenn E. January 1982 (has links)
Thesis (M.S.)--Oregon State University, 1983. / Typescript (photocopy). Includes bibliographical references (leaves 47-48). Also available on the World Wide Web.
14

The Comparison of Larval Fish Assemblages in Tapeng Bay and Kaoping Coastal Waters

Hsieh, Hung-Yen 19 August 2002 (has links)
Abstract¡G The principal objectives of this research are to investigate the species composition and distribution of larval fish in relation to water temperature¡Bsalinity¡Bchlorophyll a and the abundance of copepods in Tapeng Bay and Kaoping coastal waters. Thirty-one species of the larval fish belonging to 29 genera and 16 families were identified in Tapeng Bay, with the mean numerical abundance of 22.9 ¡Ó40.7 ind./100m3 during the sampling period between June 1999 and December 2001. The trend of seasonal change in numerical abundance of the larval fish was not coincident interannually. The 7 most dominant species were Omobranchus sp., Tridentiger obscurus, Pterogobius Zonoleucus, Blenniidae gen. sp., Gobiidae gen. sp., Entomacrodus lighti and Engraulis japonicus, occupied 94% of the total larval fish abundance¡Famong these, the first two dominant species, Omobranchus sp. and T. obscurus contributed to 80% of the total count. One hundrad and eighty-four species of the larval fish belonging to 130 genera and 69 families were identified in Kaoping coastal waters, with the mean numerical abundance of 390.6¡Ó593.5 ind./100m3 during the sampling period between June 1999 and June 2001. Generally, the numerical abundance of the larval fish showed significantly seasonal changes, with lowest in winter and up to highest value in summer. The 10 most dominant species were Sillago japonica, Engraulis japonicus, Tridentiger obscurus, Gobiidae gen. spp., Pagrus major, Scomberoides lysan, Leiognathus nuchalis, Ceratoscopelus warmingi, Scatophagus argus and Diogenichthys laternatus, occupied 67% of the total larval fish abundance. The mean abundance, species number and species diversity index of the larval fish were obvious higher in Kaoping coastal waters than in Tapeng Bay. The dominant species of larval fish in Tapeng Bay were mostly sandy benthic species (Blenniidae and Gobiidae) and coastal epipelagic species (Engraulidae). The larval fish assemblage in Kaoping coastal waters was diverse, and dominated by benthic species (Sillaginidae), sandy bottom species (Blenniidae and Gobiidae), coastal epipelagic species (Engraulidae), mesopelagic species (Myctophidae) and coastal-migrant species (Scatophagidae).
15

Systematic studies of the genus Siphateles (Ostariophysi: Cyprinidae) from western North America /

Harris, Phillip M. January 1900 (has links)
Thesis (Ph. D.)--Oregon State University, 2001. / Typescript (photocopy). Includes bibliographical references (leaves 178-189). Also available on the World Wide Web.
16

Feasibility of Habitat Banking in Manitoba

Koster, Kristine 09 April 2013 (has links)
According to the habitat protection provisions of the Fisheries Act, industry must develop or restore habitat as compensation for a “harmful alteration, disruption or destruction to fish habitat” to achieve “no net loss of the productive capacity of fish habitats (NNL).” Occasionally, compensation projects completed in accordance with the conditions of a Fisheries Act Authorization do not achieve NNL of fish habitat. The feasibility of using habitat banking as a compensation tool was investigated through qualitative document review, semi-directed interviews, site visits, and a modified Delphi approach workshop. Results indicated that habitat banking is feasible in Manitoba; however, feasibility in northern Manitoba diminishes because much of the land is owned by the Crown and is sparsely developed. It is recommended that DFO National Head Quarters develop a standard tool for measuring the productive capacity of fish habitat and strive for Canada-wide consistency in their application of the habitat banking policy.
17

Physiological and Behavioural Responses of Largemouth Bass Yearlings (Micropterus salmoides) to Hypoxia at Summer and Winter Temperatures

Li, VERA 21 October 2008 (has links)
The main objective of this thesis was to determine the metabolic and behavioural outcomes from hypoxia exposure to largemouth bass (Micropterus salmoides) yearlings when acclimated to either winter (5°C) or summer (20°C) temperatures. This was achieved by exposing largemouth bass to varying levels of hypoxia and subsequently quantifying metabolites, in addition to observing behavioural patterns. The critical partial pressure of oxygen was also determined for fish at both temperatures. Hypoxia experiments revealed that metabolite concentrations increased or decreased significantly compared to control values as hypoxia levels intensified at 20°C, however there were minimal changes for fish at 5°C. More specifically, end product concentrations of lactate increased, while substrate concentrations of ATP, PCr and glycogen decreased and glucose concentrations did not change significantly at 20°C. It was also found that the magnitude of change was greater for fish at 20°C, indicating the impact of hypoxia is greater at warmer temperatures. In addition, it was noted that hypoxia experiments performed at either identical percent oxygen saturation (%) or identical dissolved oxygen (mg/L) resulted in very similar metabolite trends at both temperatures. In terms of behaviour, ventilation rates increased significantly and peaked at 2mg/L for largemouth bass at 20°C, however there was no change for fish at 5°C. There were also more instances of aquatic surface respiration with increasing hypoxia for fish at 20°C, but nearly no attempts at 5°C. Critical partial pressure of oxygen (Pcrit) values were calculated to be 1.36 ± 0.02 mg/L (16% oxygen saturation) for 20°C and 0.77 ± 0.04 mg/L (5% oxygen saturation) for 5°C fish respectively. The Pcrit levels corresponded to the hypoxia levels that initiated changes in metabolite concentrations at each temperature, thus indicating that largemouth bass undergo anaerobic metabolism. This study shows that the overall impact of hypoxia on largemouth bass yearlings was much greater in warmer water. These results indicate that hypoxia may become a very important physiological stress on younger life stages of fish as water temperatures increase with climate change. / Thesis (Master, Biology) -- Queen's University, 2008-10-16 16:27:56.732
18

GENOMIC CHARACTERIZATION OF RECURRENT CHROMOSOMAL ABERRATIONS IN RETINOBLASTOMA

D'Silva, Crystal 19 October 2010 (has links)
Retinoblastoma is the second most common childhood intraocular malignancy and development of the tumour is initiated by bi-allelic loss of the RB1 gene. Bi-allelic RB1 loss may not always directly lead to malignant retinoblastoma. Subsequent mutational events, specifically gain and loss of chromosomal regions harbouring key oncogenes and tumour suppressor genes, appear to underlie the progression of precursor lesions such as retinoma to retinoblastoma. Research thus far has implicated several cytogenetic aberrations in this sequence of molecular events, the two most recurrent and notable being the augmented copy number status of KIF14 and MDM4 on 1q and of DEK and E2F3 on 6p. A small subset of retinoblastoma exhibits high-level amplification of the MYCN gene on chromosome 2p and is characterized by pRb expression and aggressive histology. 1p36 deletion is also associated with MYCN amplification in neuroblastoma. Our project is testing the hypothesis that 1q and 6p gain and 2p amplification – defined by extra copies of KIF14 and MDM4, DEK and E2F3 and MYCN respectively, and 1p36 deletion – are biomarkers of retinoblastoma progression. This study reports the results of formalin-fixed paraffin-embedded fluorescence in situ hybridization (FFPE-FISH) analysis of the aforementioned genes in two pre-constructed tissue microarrays (TMAs) comprising 270 retinoblastoma patient tumours. Results show 1q gain (3-10 copies) in 136/262 (52%), 6p gain in 127/262 (48.7%), MYCN gain in 18/265 (6.8%) and MYCN amplification (>10 copies) in 20/265 (7.5%) patient tumours. MYCN amplification was also observed in a sample which retained pRb protein expression. Additionally we have demonstrated statistically significant associations between 1q and 6p gain and MYCN amplification and 1p36 deletion. The large cohort and consequent statistical power of our results has enabled a better understanding of the M3 to Mn sequence of genomic aberrations in the progression from retinoma to retinoblastoma. Statistically significant associations between 1q and 6p, indicates synergy within these two regions of gain that would be particularly beneficial to tumours. Owing to the biological interactions among the proteins encoded by DEK, E2F3, KIF14 and MDM4, tumour cells manifesting both 1q and 6p aberrations would have a selective survival and proliferative advantage. / Thesis (Master, Pathology & Molecular Medicine) -- Queen's University, 2010-10-18 16:59:40.965
19

Feasibility of Habitat Banking in Manitoba

Koster, Kristine 09 April 2013 (has links)
According to the habitat protection provisions of the Fisheries Act, industry must develop or restore habitat as compensation for a “harmful alteration, disruption or destruction to fish habitat” to achieve “no net loss of the productive capacity of fish habitats (NNL).” Occasionally, compensation projects completed in accordance with the conditions of a Fisheries Act Authorization do not achieve NNL of fish habitat. The feasibility of using habitat banking as a compensation tool was investigated through qualitative document review, semi-directed interviews, site visits, and a modified Delphi approach workshop. Results indicated that habitat banking is feasible in Manitoba; however, feasibility in northern Manitoba diminishes because much of the land is owned by the Crown and is sparsely developed. It is recommended that DFO National Head Quarters develop a standard tool for measuring the productive capacity of fish habitat and strive for Canada-wide consistency in their application of the habitat banking policy.
20

Development and application of methods for extraction and LC/MS/MS analysis of sex steroids and conjugates from fish feces.

Peters, Lisa E. 24 March 2015 (has links)
Non-lethal monitoring of animals using fecal steroid analysis is frequently employed to assess the health/reproductive status of individuals or populations, and may be applied to environmental monitoring of fish. Fecal steroid analysis requires both the non-polar parent and the polar glucuronide/sulfate conjugated forms to be considered. To address this challenge in fish, a reproductive steroid extraction method with HPLC/MS/MS analysis was first developed for Cortland’s in vitro bioassay medium. A 2-step liquid:liquid extraction method successfully captured parent sex steroids and their conjugates. This method was then applied to investigate routes of endocrine disruption in trout gonads exposed to environmentally relevant concentrations of polybrominated diphenyl ether (PBDE) flame retardants, and selected metabolites. Of the two classes, hydroxylated metabolites of PBDE-47 had the greatest effect on steroidogenesis in both male and female trout gonadal tissues. The extraction and LC/MS/MS analysis techniques were then applied to fish feces. The most effective matrix treatment for feces was a lipid removal agent, CleanasciteTM. It removed lipid and pigmented compounds left by acid washing, and prolonged column life without affecting hormone recoveries. Using paired plasma and feces samples from rainbow trout it was determined that fecal estrogens could predict plasma concentrations. Changes in plasma estrogens were typically not reflected in feces, which varied less, until the subsequent week. Fecal concentrations of E2-17 glucuronide best predicted plasma E2 concentrations in female rainbow trout, while the strongest relationship was between plasma E2-3 sulfate and fecal E2-17 glucuronide. Plasma clearance time and partitioning of estrogens into feces, urine and bile was then monitored in two experiments. The first involved in vivo administration of radiolabeled E2 into the blood of rainbow trout, and in the second radiolabelled E2 was introduced into the fish gut. Overall, E2 was cleared from plasma in 72 hours, and estrogens in feces can be a composite of hormones metabolized over > 4 days. Approximately 68% of E2-H3 injected into the gut entered enterohepatic circulation. Understanding hormone metabolism and clearance, and the roles of dietary uptake and enterophepatic circulation, will facilitate further development of fecal steroid analysis as a non-lethal assessment tool for monitoring fish reproduction.

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