Doktorgradsavhandlinger (BFE-fak)
DSpace/Manakin Repository
Doktorgradsavhandlinger (BFE-fak)
Recent additions
-
Tandberg, Anne Helene S. (Doctoral thesis; Doktorgradsavhandling, 19-Dec-2011)[+][-]
Abstract: The Amphipod-genus Metopa is a relatively large genus, with currently 55 accepted species. This PhD thesis consists of redescriptions of 23 of these species based on typespecimens or specimens collected and identified by the original authors; this has been done to create consistent descriptions that could form a basis for a phylogenetic analysis of Metopa. For some species Scanning Electron Microscopy has been used to look for characters that have been overlooked by the original authors. The redescriptions are presented in 3 papers (Papers 1-3), with a phylogenetic analysis of 37 Metopa species (mostly based on personal examinations, but 6 based on literature-information) together with 6 Stenula species (partly based on literature, but most from examinations performed by Dr. Traudl Krapp-Schickel) presented in a manuscript (Paper 6). The result of the phylogenetic analysis is two clear clades (A and B), both including species from both original genera. This result could suggest a thorough change in stenothoid systematics, with the possible synonymization of Stenula into the older Metopa and erection of one or more new genera to include the species of clade A, but we have argued against doing this before further investigations have been undertaken. The stability of the resulting phylogeny is discussed, and in our opinion further studies are necessary to strengthen the conclusions reached here, before we formally make the necessarily very extensive nomenclatorial changes. However, the indications that Metopa and Stenula are paraphyletic are strong. Two papers (Papers 4-5) examine the ecology of Metopa species associated with mollusks. Paper 4 is a short note about findings of Metopa alderii inside the mussel Musculus spp., whereas Paper 5 is a more thorough discussion on the possible life history strategies for Metopa glacialis in its well known association with the mussel Musculus discors based on data collected by Svalbard. We show the presence of more than one broods in several examined mussels, and from the brood sizes and cohort compositions we suggest two possible scenarios: 3 or more seasons of single broods and parental care over more than 1 year after hatching, or multiple broods in one season and extended parental care. The introductory synthesis to the papers gives a short discussion of the papers, in addition to a historical introduction to both taxonomy and the amphipod-genus Metopa. A complete list of taxa that at some time have been included in Metopa is presented, this includes synonymies and references to the auctors and different authors who have moved the different taxa. There is also a table with biogeographical information about the genus, and the ecology of Metopa is discussed. A short discussion on molecular methods and the possible ways to ensure more data for a better phylogenetic analysis is also included. Description: The papers of this thesis are not available in Munin.
1. Tandberg, A.H.S. and Vader, W.: 'A redescription of Metopa species (Amphipoda, Stenothoidae) based on the type material. 1. Zoological Museum, Copenhagen (ZMUC)', Zootaxa (2009) 2093:1-36. Available at http://www.mapress.com/zootaxa/
2. Tandberg, A.H.S.: 'A redescription of Metopa species (Amphipoda, Stenothoidae) based on the type material. 2. The United States National Museum of Natural History (NMNH)', Zootaxa (2009) 2309:43-68. Available at http://www.mapress.com/zootaxa/
3. Tandberg, A.H.S.: 'A redescription of Metopa species (Amphipoda, Stenothoidae) based on the type material. 2. The Natural History Museum Oslo (NHM)', Zootaxa (2010) 2465:1-94. Available at http://www.mapress.com/zootaxa/
4. Tandberg, A.H.S., Schander, C. and Pleijel, F.: 'First record of the association between the amphipod Metopa alderii and the bivalve Musculus', Marine Biodiversity Records (2010) 3, e5. Available at http://dx.doi.org/10.1017/S1755267209991102
5. Tandberg, A.H.S., Vader, W. and Berge, J.: 'Metopa glacialis : an analysis of its ecology and its association with Musculus discors', Polar Biology (2010) 33:1407-1418. Available at http://dx.doi.org/10.1007/s00300-010-0833-9
6. Tandberg, A.H.S. and Vader, W.: 'Phylogenetic analysis of the stenothoid genera Metopa and Stenula (Crustacea, Amphipoda, Stenothoidae)' (manuscript)URI: http://hdl.handle.net/10037/3808 File(s) in this item: 1
thesis.pdf (35.46Mb) -
Hynes, Natasha (Doctoral thesis; Doktorgradsavhandling, 18-Oct-2011)[+][-]
Abstract: Flagellin is the principal structural protein in the locomotive organ flagellum present on flagellated bacteria, and is known to be an important evolutionarily conserved PAMP. Flagellin has been shown to bind to the PRR TLR5 which induces innate immune system responses and signaling pathways. In mammals, much focus has been placed on this protein in vaccine studies for its possible function as an adjuvant. Flagellin (FlaD from Vibrio anguillarum) was recombinantly produced in two forms, full-length (FDL) and a truncated form (FDS) with portions of the N- and C-termini removed to prevent polymerization. Both forms of flagellin were tested alone and in combination with an antigen in a dose response study to determine the most effective dosage to produce a strong immune response. A polyclonal antibody for FDS was produced and showed good specificity in immunoblot testing. Cell culture was used to compare the NF-κB response after stimulation with FDL versus FDS and resulted in a significantly larger response in cells stimulated with FDL. QPCR mRNA gene expression results showed a strong innate immune response with a number of genes known to be induced downstream by the TLR signaling pathway up- regulated including important TLR5S and inflammatory cytokines and chemokines (TNFα, IL-6, IL-8, IL-1β). Microarray analysis of salmon injected with flagellin caused reproducible gene up-regulation of inflammatory cytokines, chemokines and receptors (IL-8, TNFRSF11B, IL-1R), antimicrobial peptides (hepcidin, cathelicidin), immune genes (C/EBP, thioredoxin, C-type lectin receptor B), complement genes (complement component C7 and C7-1), peptidases (MMP-9) and genes involved in the Ras/MAPK pathway (Ras-related proteins). Down-regulation of interesting immune genes also occurred including myxovirus resistance 1, clusterin-1 and LPS-induced TNF-α homolog. Some genes exhibited early, delayed or extended response over the sampling time and flagellin seemed to be the key component to eliciting a response. Flagellin was shown to induce innate immune responses in Atlantic salmon. Description: The papers of this thesis are not available in Munin:
1. Natasha A. Hynes, Clemens Furnes, Børge Nilsen Fredriksen, Tori Winther, Jarl Bøgwald, Atle N. Larsen, Roy A. Dalmo: 'Immune response of Atlantic salmon to recombinant flagellin', Vaccine (2011) vol. 29, no 44, pp 7678–7687. Available at http://dx.doi.org/10.1016/j.vaccine.2011.07.138
2. Natasha A. Hynes, Tiago S. Hori, Roy A. Dalmo and Matthew L. Rise: 'Functional genomics analysis of the immunological responses of Atlantic salmon (Salmo salar) spleen to injection with recombinant flagellin from Vibrio anguillarum' (manuscript)URI: http://hdl.handle.net/10037/3798 File(s) in this item: 1
thesis.pdf (1.079Mb) -
Jensen, Louise Kiel (Doctoral thesis; Doktorgradsavhandling, 11-Nov-2011)[+][-]
Abstract: Summary Petroleum exploitation is emerging in the Arctic. In the Norwegian Arctic the southern Barents Sea is opened for development of oil and gas fields. This same area holds some of the world's largest and well managed commercial fish stocks such as Herring (Clupea harengus), Capelin (Mallotus villosus), Haddock (Melanogrammus aeglefinus), Atlantic Cod (Gadus morhua). For the interest of the fishing industry, as well as for maintaining a healthy ecosystem, petroleum related Environmental Risk Assessments (ERA) for the Barents Sea must be based on sound scientific knowledge of the special features of the Arctic ecosystem. In colder areas the physical behavior of oil is different compared to warmer areas. The lower temperature and lack of sun light during the Arctic winter slows down the natural physical weathering process of oil. In ERA in temperate areas the effects of exposure to the most volatile fraction of the oil are neglected due to short exposure time. However, in the Arctic the exposure to biota of this volatile fraction may be prolonged due to lower evaporation rates and the volatile fraction may be an important contributor to the overall adverse effect of an oil spill. Likewise, the exposure to the heavier oil fractions may be prolonged and knowledge on the long-term effects of exposure is essential. As an adaptation to the Arctic environment species found here have longer life spans, larger body sizes and higher lipid contents compared to temperate equivalent species. Thus Arctic species may accumulate contaminants over longer time and reach higher life time body levels. Meanwhile higher lipid content implies a higher affinity of lipophilic contaminants such as polycyclic aromatic hydrocarbons (PAHs). So, Arctic species may be exposed to oil compounds for a longer time because of the prolonged phycical presence and may, due to special adaptive features, be more efficient at accumulating oil contaminants. Today the knowledge of effects of oil contaminants on Arctic biota is limited, but growing. This thesis addresses a few of the research challenges in the field and provides knowledge on some effects of petroleum exposure to two copepod species; the sub-Arctic Calanus finmarchicus and the Arctic sibling species C. glacialis. First, Calanus was cultured for a generations under sub-Arctic conditions (Paper I). This work establishes that Calanus is suitable for ecological relevant long-term experiments. In an oil spill scenario, Arctic copepods and algae may be exposed to the more volatile fraction of the oil. Paper II provides data showing that the Arctic diatom species, Fragilariopsis oceanica, was the most sensitive species to exposure to the volatile hydrocarbon xylene. Further, the smaller, less lipid rich copepod species C. finmarchicus, was more sensitive compared to the true Arctic C. glacialis. Extrapolating these results to a spill situation, C. finmarchicus and C. glacialis populations would be affected by xylene exposure through both direct exposure (mortality) and indirectly through a decline in prey organisms (algae). Sub-lethal effects after long-term exposures to low concentrations of oil compounds may also be detected in C. finmarchicus and C. glacialis. Feeding was suppressed in C. finmarchicus after exposure to 7.0 µg PAHs l-1 for 11 days (Paper III). No significant effect on feeding was detected in C. glacialis exposed to 10.4 µg PAHs l-1 for 11 days. However, the hatching success of eggs laid by females exposed to 10.4 µg PAHs l-1 for two days was significantly reduced (Paper III). The long term effects of lipophilic PAHs in biota depend on the bioaccumulation capacity and internal concentrations of the various PAHs. Accumulation of lipophilic compounds is particularly important for the lipid rich Arctic species. Paper IV examines the uptake kinetics of two PAHs in C. finmarchicus and show that the accumulation of the lighter and less lipophilic compound, phenanthrene, is faster that the uptake of the heavier and more lipophilic benzo[a]pyrene (B[a]P). Equilibrium was reached for phenanthrene within 192 h exposure while no equilibrium was detected for B[a]P. The bioconcentration factor (BCF) was higher for B[a]P, reflecting the higher affinity for lipids of B[a]P compared to phenanthrene (Paper IV). So the heavier, more lipophilic PAH accumulates slower but to a higher concentration in C. finmarchicus. This thesis shows that not only acute but also long-term exposures may affect Arctic species. In addition, exposure duration may determine which compounds are accumulated by biota. Both indirect effects, such as decrease of food items, and direct effects, such as mortality, reduced feeding and reproduction failure may have implications for population development. These findings should be taken into consideration when developing ERA for the Barents Sea area. Description: Papers 1 and 2 of this thesis are not available in Munin:
1. Jensen, L.K., Carroll, JL., Pedersen, G., Hylland, K., Dahle, S. and Bakke, T.: 'A multigeneration Calanus finmarchicus culturing system for use in long-term oil exposure experiments', Journal of Experimental Marine Biology and Ecology (2006) 333: 71-78. Available at http://dx.doi.org/10.1016/j.jembe.2005.12.001
2. Jensen, L.K. and Carroll, JL.: 'Effects of the volatile petroleum component xylene on Arctic algae and zooplankton' (submitted manuscript to Marine Environmental Research).URI: http://hdl.handle.net/10037/3794 File(s) in this item: 3
paper_3.pdf (312.1Kb)paper_4.pdf (161.7Kb)thesis.pdf (1.551Mb) -
Hodal, Helene (Doctoral thesis; Doktorgradsavhandling, 02-Dec-2011)[+][-]
Abstract: The Arctic is one of the least studied regions in the world and large changes in marine ecosystem dynamic are expected here because of the increasing air and ocean temperature. The central Arctic Ocean has for a long time been considered as a very low productive ecosystem, but recent estimates of primary production gives relatively high values. The shelves surrounding the Arctic Ocean are highly productive areas, especially the Barents Sea region, and a large part of arctic primary production occurs in these seasonally ice-covered regions. The relevance of small cells in arctic ecosystems has received increased attention the last two decades, and it is now accepted that the microbial food web play an important role also in the Arctic. To increase the knowledge on primary production and the relevance of small autotrophic and heterotrophic cells in the Arctic different field studies were conducted. Spring bloom dynamics (nutrients, phytoplankton, protozoans and in situ primary production) were investigated in Kongsfjorden (Svalbard) in April and May in 2002. During the multidisciplinary CABANERA-project three field campaigns in 2003-2005 to the marginal ice zone of the northern Barents Sea were conducted. Primary production was measured in situ for 24 hours at different stages of ice-edge blooms. Primary production and chlorophyll a measurements were fractionated in small (<10µm) and large cells (>10µm). During an expedition across the Arctic Ocean in August and September 2005 different biological parameters were measured (chlorophyll a, biogenic silica, particulate carbon and nitrogen, few zooplankton samples) together with the distribution of autotrophic and heterotrophic microbial biomass. Bacteria abundance was estimated using flow-cytometry and protists abundance was analyzed by epifluorescence microscopy after staining with DAPI. Protists were divided in different size categorize: < 2µm, 2-5µm, 5-10µm and 10-20µm. A seasonally study (January-September) of bacteria community structure and activity was conducted in a cold high latitude fjord (Balsfjord, northern Norway) in 2009 using fluorescence in situ hybridization (FISH) combined with microautoradiography (micro-FISH). In Kongsfjorden we found that the onset of the spring bloom was linked to the hydrographical situation during the sea ice break up. The peak of the spring bloom was found to vary between different years in both timing and intensity but will most probably occur between the middle-end of April and the middle of May. Primary production in 2002 persisted for a long time due to mixing with nutrient rich water masses. The ice edge phytoplankton bloom in the marginal ice zone of the northern Barents Sea was very heterogenic and no patterns in integrated primary production could be assigned to stages or latitudes. Subsurface (20-60m) primary production contributed with 24% to the total integrated primary production during ice edge blooms in the marginal ice zone, illustrating the importance of sampling in subsurface maxima. Small cells contributed with 46% to total primary production during ice edge blooms underlining the important role small cells can play as primary producers. Picoplankton (<2µm) abundance was high in the Arctic Ocean, and in the central part heterotrophic cells dominated (72%). Bacteria abundance was very low in the central part of the Arctic Ocean, but it is unknown whether this was caused by low growth rates or by high predation pressure. Bacteria were found to be highly active during summer in the Balsfjord underlining the important role they play in carbon turnover in the ocean. Bacteria belonging to Roseobacter were very active in assimilating DOM but they were not very abundant. This suggests that species specific predation may regulate the abundance of active bacteria. The main conclusion from the work included in this synthesis is that small cells are an important component of arctic food webs. Small cells need to be considered as important primary producers, also during spring blooms and ice edge blooms. We also found that bacteria need to be studied on single cell level to understand the underlying reasons for the dynamics that are observed on community levels. Description: Papers 2,3 and 4 are not available in Munin:
2. Hodal H and Kristiansen S.: 'The importance of small-celled phytoplankton in spring blooms at the marginal ice zone in the northern Barents Sea', Deep-Sea Research Part II (2008) 55: 2176-2185. Available at http://dx.doi.org/10.1016/j.dsr2.2008.05.012
3. Kristiansen S, Hodal H and Reigstad M.: 'Autotrophic and heterotrophic microbial biomass across the Arctic Ocean' (manuscript)
4. Hodal H, Kirchman D, Kristiansen S, Straza T.: 'Bacteria diversity and single-cell activity in a cold high latitude fjord (Balsfjord) from winter to late summer 2009' (manuscript)URI: http://hdl.handle.net/10037/3783 File(s) in this item: 2
paper_1.pdf (838.0Kb)thesis.pdf (1.114Mb) -
Hegseth, Marit Nøst (Doctoral thesis; Doktorgradsavhandling, 29-Nov-2011)[+][-]
Abstract: This PhD study has investigated how two commonly occurring environmental stress factors in the Arctic (periods with little food and exposure to halogenated organic contaminants) have had an impact on two important cellular defense mechanisms in Arctic seabirds. The antioxidant defense system and autophagic lysosomal responses in liver cells of Arctic seabird chicks have been studied. Samples were collected from three seabird species at Svalbard and Tromsø area: Black-legged kittiwake (Rissa tridactyla), northern fulmar (Fulmarus glacialis) and herring gull (Larus argentatus ), as well as samples from a feeding experiment with herring gull chicks. The findings show that there are major species differences, and that the antioxidant defense system and autophagic lysosomal responses in the seabird chicks are affected by factors such as diet, species-specific physiology and fasting, as well as high-grade contaminant exposure. Some of the effects of contaminant exposure were dose-dependent. The contaminant concentrations found in the birds in this study were relatively low. Hence, more pronounced effects could therefore be present in wild-living birds that have higher contaminant concentrations than birds in this study. Some of the cellular effects observed in this study have been associated with adverse health effects in other animal species. Additional studies of these cellular systems in seabirds are recommended in order to implement such analysis in regularly monitoring of seabird health status in the future and may contribute to improved management of the important seabird populations in these areas. Description: The papers of this thesis are not available in Munin:
1. Marit Nøst Hegseth, Lionel Camus, Lisa Bjørnsdatter Helgason, Raffaella Bocchetti, Geir Wing Gabrielsen and Francesco Regoli: 'Hepatic antioxidant responses related to levels of PCBs and metals in chicks of three Arctic seabird species', Comparative Biochemistry and Physiology Part C: Toxicology & Pharmacology (2011) 154: 28-35. Available at http://dx.doi.org/10.1016/j.cbpc.2011.02.008
2. Marit Nøst Hegseth, Lionel Camus, Stefania Gorbi, Francesco Regoli and Geir Wing Gabrielsen: 'Effects of exposure to halogenated organic compounds combined with dietary restrictions on the antioxidant defense system in herring gull chicks', Science of the Total Environment (2011) 409 (14):2717-24. Available at http://dx.doi.org/10.1016/j.scitotenv.2011.04.004
3. Marta K. Jansen, Marit Nøst Hegseth, Raffaella Bocchetti, Francesco Regoli, Geir W. Gabrielsen and Lionel Camus: 'Impact of Halogenated Organic Contaminant Exposure and Fasting on Antioxidant Defence System on the Kidney of Herring Gull Chicks' (manuscript)
4. Marit Nøst Hegseth, Francesco Regoli, Stefania Gorbi, Raffaella Bocchetti, Geir Wing Gabrielsen and Lionel Camus: 'Lysosomal and lipid-associated parameters in the livers of three species of arctic seabird chicks : Species differences and relationships with contaminant levels', Marine Pollution Bulletin (2011) 62(8): 1652-60. Available at http://dx.doi.org/10.1016/j.marpolbul.2011.06.011
5. Marit Nøst Hegseth, Stephania Gorbi, Raffaella Bocchetti, Geir Wing Gabrielsen, Francesco Regoli and Lionel Camus: 'Effects of contaminant exposure and food restriction on hepatic lysosomal and lipid associated parameters in Herring gull chicks' (submitted manuscript to Environmental Research)URI: http://hdl.handle.net/10037/3780 File(s) in this item: 1
thesis.pdf (1.633Mb)
Search Munin
Browse
-
All of Munin
-
This Collection
Help
Munin is powered by DSpace 1.6.2
The University Library of Tromsø, N-9037 Tromsø
Tel: +47 77 64 40 00, E-mail: munin@ub.uit.no