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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.
31

Use of a Net Rate of Energy Intake Model to Examine Differences in Juvenile Steelhead (Oncorhynchus mykiss) Densities and the Energetic Implications of Restoration

Wall, C. Eric 01 May 2014 (has links)
The Bonneville Power Administration (BPA) Fish and Wildlife Program mitigates for impacts of hydroelectric dams on ESA-listed salmon and steelhead populations in the Columbia River Basin (CRB). Considering the sizable investments in mitigation and the diversity of stream habitats within the CRB, there has been a pointed effort to develop and identify meaningful metrics relating to fish populations and trends in their habitat across the CRB. The Integrated Status and Effectiveness Monitoring Program (ISEMP) was developed in 2003 specifically for this purpose, and is tasked with developing and testing strategies for determining the status and trend of salmonid populations and their habitats in the CRB. This thesis was funded by the BPA, ISEMP, Eco Logical Research Inc., the Snake River Salmon Recovery Board, and the Intensively Monitored Watershed project in the Asotin Creek basin with the purpose of investigating the efficacy of foraging modeling as part of a large fish habitat monitoring program. The primary objectives were i) to assess a foraging model's ability to predict fish density in study sites involved in long-term monitoring and ii) to evaluate energetic implications of restoration design and progress after implementation using a foraging model. To assess the foraging model's ability to predict fish density (objective i), we collected topography, drift, temperature, discharge, and fish population information to support foraging modeling, and we simulated flow patterns, drift, foraging, swimming costs, carrying capacity, and density. We then compared observed and predicted densities in 22 study sites from the John Day and Asotin Creek watersheds: Linear regression between observed and predicted fish densities was significant (R2 = 0.61, p < 0.001). When assuming spatially uniform drift densities and small fish territories, carrying capacity predictions were related to the number of foraging locations simulated, suggesting the model is highly sensitive to territory size assumptions. To evaluate restoration design and monitor restoration progress (objective ii), we simulated foraging before restoration, after a virtual restoration (carried out using the restoration designs in a GIS environment), and again followinfg restoration implementation. We used raster differencing to compare the "before" results to the virtual restoration results and then the "before" results to the "after" results. Hydraulic and foraging models suggested: Mean net energy intake increased following both simulated and actual restoration. Restoration structures generally slowed water's progress through the study site or caused pooling, both resulting in an increase in energetically favorable areas. Generally, more areas shifted from another state to having an acceptable energy balance than to an unacceptable energy balance.
32

Susceptibility of select salmonids to Myxobolus cerebralis and effects of exposure on anadromous salmonids in Oregon

Sollid, Sarah A. 27 September 2002 (has links)
Myxobolus cerebralis, a myxozoan parasite of salmonids, is the causative agent of whirling disease. The parasite is considered widespread throughout northeastern Oregon in the Grande Ronde and Imnaha River basins where threatened and endangered salmonid populations exist. The work presented in this thesis comprises several studies that assess the effects of M. cerebralis on resident and anadromous salmonids in Oregon. Laboratory challenges to determine the susceptibility of indigenous Deschutes River, Oregon, salmonids to M. cerebralis were conducted as part of a study to assess the risk of reintroducing anadromous salmon above a migration barrier on that river. This study was the first to assess the susceptibility of kokanee salmon Oncorhynchus nerka to M. cerebralis, and results contribute to the understanding of salmonid susceptibility as it relates to species and age. Further, this study demonstrates that the indigenous salmonids present in the river are susceptible to infection, but resident rainbow trout Oncorhynchus mykiss would be most at risk should introduction of M. cerebralis occur in this system. The susceptibility of chinook salmon Oncorhynchus tshawytscha to M. cerebralis was assessed following laboratory challenges at different ages to different parasite levels. Results from this study indicate that chinook salmon are more resistant to M. cerebralis infection than susceptible rainbow trout; resistance to disease developed in chinook salmon exposed after 3 weeks of age. Sustained exposures to a low parasite dose were performed to model the conditions chinook salmon would encounter in a natural exposure. Following continuous exposure to low parasite densities, chinook salmon were very resistant to infection and disease. Managed populations of chinook salmon and steelhead Oncorhynchus mykiss juveniles are held in acclimation facilities on their natal streams before release to commence their seaward migration. Rainbow trout fry were held at each of the acclimation facilities to detect the presence of M. cerebralis and to assess the prevalence of exposure during the acclimation period. Results from these exposures indicate that the Wallowa acclimation facility is a high-risk site for parasite exposure of steelhead juveniles. Further, detection was confirmed in several rivers and streams where the presence of M. cerebralis has been suggested. Finally, a preliminary study on the effect of M. cerebralis on survival of steelhead juveniles upon transfer to saltwater was conducted. Results from this study indicate that M. cerebralis exposure and infection may increase mortality among juvenile steelhead during saltwater adaptation. / Graduation date: 2003
33

Corticosteroidogenesis as a Target of Endocrine Disruption for the Antidepressant Fluoxetine in the Head Kidney of Rainbow Trout (Oncorhynchus mykiss)

Stroud, Pamela A 11 January 2012 (has links)
Fluoxetine (FLX), the active ingredient of Prozac™, is a member of the selective serotonin reuptake inhibitor (SSRI) class of anti-depressant drugs and is present in aquatic environments worldwide. Previous studies reported that FLX is an endocrine disruptor in fish, bioconcentrating in tissues including the brain. Evidence implicates that serotonin influences the activity of the hypothalamo-pituitary-interrenal (HPI) stress axis, thus exposure to FLX may disrupt the teleost stress response. This study examined in vitro cortisol production in rainbow trout (Oncorhynchus mykiss) head kidney/interrenal cells exposed to FLX and 14C-pregnenolone metabolism in head kidney microsome preparations of FLX-exposed trout. Results indicated that cells exposed in vitro to increasing concentrations of FLX had lower cortisol production and cell viability (versus control) and microsomes isolated from trout exposed to 54 μg/L FLX had higher pregnenolone metabolism versus those of control and low FLX-exposed (0.54 μg/L) trout.
34

Use of bioelectrical impedance analysis (BIA) to predict water and energy content of juvenile Rainbow Trout (Oncorhynchus mykiss)

Bourdages, Christopher 01 August 2011 (has links)
Accurate measurements of energy content and body composition are essential to effectively assess the well-being of fish. Bomb calorimetry and proximate analysis are currently the most dependable and accurate methods to estimate energy content and body composition. However, bioenergetic studies that employ the traditional methodology necessitate the killing of fish to determine physiological composition and energy content in a target tissue. The killing of the individual negates the ability for repeated measures on the same individual, and also suppresses compositional studies involving endangered or threatened species. Recent research has shown Bioelectrical Impedance Analysis (BIA), a quick, easy-to-use, non-invasive, and most importantly, non lethal technique to be an effective method for estimating the proximate composition and energy content of fish. The focus of this research is to evaluate the capability of BIA to accurately assess the bioenergetics of juvenile rainbow trout (Oncorhynchus mykiss), and to develop species-specific indices to predict energy content, total body water and dry mass. To do this, juvenile rainbow trout were subjected to one of three ration regimes: maintenance (0.4 % bw/day), optimum (1.9 % bw/day) and satiation (3.4 % bw/day) for 90 days. Subsamples from each treatment were taken every 30 days to be subjected to BIA testing. Tissue samples were collected from the subsampled trout for future caloric and compositional analysis via bomb calorimetry and proximate analysis. It was found that BIA demonstrated a strong predictive relationship with regard to energy content (r2 = 0.90), total body water (r2 = 0.89) and dry mass (r2 = 0.80). BIA was also able to successfully reflect a notable statistical difference between treatments with regard to total energy content, energy density, total body water, dry mass. These results, along with much of the existing literature, indicate that BIA may be an accurate and reliable tool to estimate the bioenergetics and proximate composition of fish. / UOIT
35

Corticosteroidogenesis as a Target of Endocrine Disruption for the Antidepressant Fluoxetine in the Head Kidney of Rainbow Trout (Oncorhynchus mykiss)

Stroud, Pamela A 11 January 2012 (has links)
Fluoxetine (FLX), the active ingredient of Prozac™, is a member of the selective serotonin reuptake inhibitor (SSRI) class of anti-depressant drugs and is present in aquatic environments worldwide. Previous studies reported that FLX is an endocrine disruptor in fish, bioconcentrating in tissues including the brain. Evidence implicates that serotonin influences the activity of the hypothalamo-pituitary-interrenal (HPI) stress axis, thus exposure to FLX may disrupt the teleost stress response. This study examined in vitro cortisol production in rainbow trout (Oncorhynchus mykiss) head kidney/interrenal cells exposed to FLX and 14C-pregnenolone metabolism in head kidney microsome preparations of FLX-exposed trout. Results indicated that cells exposed in vitro to increasing concentrations of FLX had lower cortisol production and cell viability (versus control) and microsomes isolated from trout exposed to 54 μg/L FLX had higher pregnenolone metabolism versus those of control and low FLX-exposed (0.54 μg/L) trout.
36

Bioactive phytochemicals in flaxseed : with particular emphasis on the secoisolariciresinol oligomer /

Johnsson, Pernilla, January 2009 (has links) (PDF)
Diss. (sammanfattning) Uppsala : Sveriges lantbruksuniversitet, 2009. / Härtill 5 uppsatser.
37

Naftos ir naftos ploviklio Simple Green bendras toksinis poveikis vaivorykštiniam upėtakiui ankstyvoje ontogenezėje / The toxic effects of crude oil combined with oil cleaner "simple green" on rainbow trout in ontogenesis

Ratkelytė, Eglė 08 September 2009 (has links)
NAFTOS IR NAFTOS PLOVIKLIO SIMPLE GREEN BENDRAS TOKSINIS POVEIKIS VAIVORYKŠTINIAM UPĖTAKIUI ANKSTYVOJE ONTOGENEZĖJE E. Ratkelytė Vilniaus universitetas Santrauka Tyrimai buvo atlikti su vaivorykštinio upėtakio (Oncorhynchus mykiss) ikrais (nuo „akutės“ stadijos) ir lervomis (nuo jų išsiritimo pradžios iki trynio maišelio rezorbcijos), veikiant juos 0,11, 0,22, 0,43, 0,87, 1,73, 3,46, 6,93 g/l naftos koncentracijomis į kiekvieną iš jų pridedant 0,5 g/l ploviklio Simple Green. Toksiškumo kriterijai buvo upėtakio ikrų ir lervų žuvimo procentas, ir tokie fiziologiniai rodikliai, kaip širdies (ŠD) bei kvėpavimo (KD) dažniai. Darbo tikslas buvo ištirti naftos ir naftos ploviklio Simple Green bendrą toksinį poveikį vaivorykštiniam upėtakiui (Oncorhynchus mykiss) ankstyvose jo vystymosi stadijose priklausomai nuo koncentracijos ir poveikio trukmės bei įvertinti ilgalaikio poveikio fiziologiniams rodikliams ypatumus. Apibendrinus gautus rezultatus galima teigti, kad vaivorykštinio upėtakio jautrumas naftos ir ploviklio Simple Green mišiniui priklauso nuo mišiniu veikiamos individo vystymosi stadijos, poveikio trukmės, ir naftos bei ploviklio koncentracijų santykio mišinyje. Nustatyta, kad jautriausios naftos poveikiui pasirodė lervutės ritimosi metu, mažiau jautrūs pasirodė embrionai ankstyvoje „akutės“ stadijoje. Palyginus gautus rezultatus su rezultatais gautais tiriant vien tik naftos poveikį vaivorykštiniam upėtakiui ankstyvoje ontogenezėje, matome, kad ploviklis Simple Green... [toliau žr. visą tekstą] / THE TOXIC EFFECT OF CRUDE OIL COMBINED WITH OIL CLEANER „SIMPLE GREEN“ ON RAINBOW TROUT IN EARLY ONTOGENESIS E. Ratkelytė Vilnius University Summary Long-term effects of crude oil combined with oil cleaner „Simple Green“ were evaluated in chronic toxicity tests by use of rainbow trout (Oncorhynchus mykiss) in early stages of development (embryos, larvae) as test-objects. The following toxicity criteria were studied for evaluation of toxic effects: mortality of embryos and larvae; physiological parameters (heart rate, ventilation frequency). The aim of the study was to investigate the overall effect of crude oil combined with oil cleaner „Simple Green“ on rainbow trout (Oncorhynchus mykiss) in early development stages (embryos, larvae) depending on oil concentration in the mixture and exposure duration and to evaluate the specificity of negative effects of mixture on physiological parameters of fish. It was determined that 0.87, 1.73, 3.46 and 6.93 g/l concentrations of crude oil combined with 0.5 g/l of “Simple Green” resulted in the significant increase in larvae mortality, but practically had no negative effect on embryos. Hatching was found to be the most sensitive stage of development, 1 day age larvae were less and embryos were the least sensitive to the toxic impact of mixture, respectively. It was estimated that 0.87+0.5, 1.73+0.5, 3.46+0.5 and 6.93+0.5 g/l concentrations of crude oil combined with oil cleaner „Simple Green“ disturbed the work of cardiorespiratory... [to full text]
38

Corticosteroidogenesis as a Target of Endocrine Disruption for the Antidepressant Fluoxetine in the Head Kidney of Rainbow Trout (Oncorhynchus mykiss)

Stroud, Pamela A 11 January 2012 (has links)
Fluoxetine (FLX), the active ingredient of Prozac™, is a member of the selective serotonin reuptake inhibitor (SSRI) class of anti-depressant drugs and is present in aquatic environments worldwide. Previous studies reported that FLX is an endocrine disruptor in fish, bioconcentrating in tissues including the brain. Evidence implicates that serotonin influences the activity of the hypothalamo-pituitary-interrenal (HPI) stress axis, thus exposure to FLX may disrupt the teleost stress response. This study examined in vitro cortisol production in rainbow trout (Oncorhynchus mykiss) head kidney/interrenal cells exposed to FLX and 14C-pregnenolone metabolism in head kidney microsome preparations of FLX-exposed trout. Results indicated that cells exposed in vitro to increasing concentrations of FLX had lower cortisol production and cell viability (versus control) and microsomes isolated from trout exposed to 54 μg/L FLX had higher pregnenolone metabolism versus those of control and low FLX-exposed (0.54 μg/L) trout.
39

Behavioural and neuroendocrine effects of stress in salmonid fish /

Øverli, Øyvind, January 1900 (has links)
Diss. (sammanfattning) Uppsala : Univ., 2001. / Härtill 5 uppsatser.
40

Corticosteroidogenesis as a Target of Endocrine Disruption for the Antidepressant Fluoxetine in the Head Kidney of Rainbow Trout (Oncorhynchus mykiss)

Stroud, Pamela A January 2012 (has links)
Fluoxetine (FLX), the active ingredient of Prozac™, is a member of the selective serotonin reuptake inhibitor (SSRI) class of anti-depressant drugs and is present in aquatic environments worldwide. Previous studies reported that FLX is an endocrine disruptor in fish, bioconcentrating in tissues including the brain. Evidence implicates that serotonin influences the activity of the hypothalamo-pituitary-interrenal (HPI) stress axis, thus exposure to FLX may disrupt the teleost stress response. This study examined in vitro cortisol production in rainbow trout (Oncorhynchus mykiss) head kidney/interrenal cells exposed to FLX and 14C-pregnenolone metabolism in head kidney microsome preparations of FLX-exposed trout. Results indicated that cells exposed in vitro to increasing concentrations of FLX had lower cortisol production and cell viability (versus control) and microsomes isolated from trout exposed to 54 μg/L FLX had higher pregnenolone metabolism versus those of control and low FLX-exposed (0.54 μg/L) trout.

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