Dissertations / Theses on the topic 'Bioligy'

Small GTP binding proteins function as molecular switches which cycles between GTP-bound ON and GDP-bound OFF states, and regulate a wide variety of cellular processes as biological timers. The first characterized member of the small GTPase family, the mutated oncogene p21 src, later known as Harvey-Ras, was identified in the early 1980s (Shih, T. Y. et al. 1980). In the following years small Ras-lik GTPases were found in several organisms and it was soon discovered that they took part in processes, such as signal transduction, gene expression, cytoskeleton reorganisation, microtubule organisation, and vesicular and nuclear transport. The first Rho (Ras homology) gene was cloned in 1985 from the sea slug Aplysia (Madaule, P. et al. 1985) and because of their homology to Ras it was first suspected that they could act as oncogenes. Later studies have shown that even though they participate in processes such as cell migration and motility they are not mutated in cancers.

The first indications that Rho was a signaling protein regulating the actin cytoskeleton, came from experiments where activated forms of human RhoA was microinjected into 3T3 cells (Paterson, H. F. et al. 1990). Another Rho-like GTPase Rac1 (named after Ras-related C3 botulinum toxin substrate) was later shown to regulate actin cytoskeletal dynamics as well, suggesting that Rho-family members cooperate in controlling these processes (Ridley, A. J. et al. 1992). The Rac GTPase was also implicated in regulating the phagocytic NADPH oxidase, which produce superoxide for killing phagocytized microorganisms (Abo, A. et al. 1991). Thus, it soon became clear that Rac/Rho and the related GTPase Cdc42 (cell division cycle 42) had central functions in many important cellular processes.

There are at least three types of regulators for Rho-like proteins. The GDP/GTP exchange factors (GEFs) which stimulates conversion from the GDPbound form to the GTP-bound form. GDP dissociation inhibitors (GDIs) decrease the nucleotide dissociation from the GTPase and retrieve them from membranes to the cytosol. GTPase activating proteins (GAPs) stimulates the intrinsic GTPase activity and GTP hydrolysis. In addition there are probably regulators that dissociate GDI from the GTPase leaving it open for activation by the RhoGEFs.

Ras and Rho-family proteins participate in a coordinated regulation of cellular processes such as cell motility, cell growth and division. The Ral GTPase is closely related to Ras and recent studies have shown that this GTPase is involved in crosstalk between both Ras and Rho proteins (Feig, L. A. et al. 1996; Oshiro, T. et al. 2002). Ral proteins are not found in plants and they appear to be restricted to animalia and probably yeast. During a screen for small GTPases in Drosophila melanogaster I discovered in 1993 several new members of the Ras-family, such as Drosophila Ral (DRal), Ric1 and Rap2. The functions of Ral GTPases in Drosophila have until recently been poorly known, but in paper 2 we present some of the new findings.

Rho-like GTPases have been identified in several eukaryotic organisms such as, yeast (Bender, A. et al. 1989), Dictyostelium discoideum (Bush, J. et al. 1993), plants (Yang, Z. et al. 1993), Entamoeba histolytica (Lohia, A. et al. 1993) and Trypanosoma cruzi (Nepomuceno-Silva, J. L. et al. 2001). In our first publication, (Winge, P. et al. 1997), we describe the cloning of cDNAs from RAC-like GTPases in Arabidopsis thaliana and show mRNA expressions pattern for five of the genes. The five genes analyzed were expressed in most plant tissues with the exception of AtRAC2 (named Arac2 in the paper), which has an expression restricted to vascular tissues. We also discuss the evolution and development of RAC genes in plants. The third publication, (Winge, P. et al. 2000), describe the genetic structure and the genomic sequence of 11 RAC genes from Arabidopsis thaliana. As most genomic sequences of the AtRACs we analyzed came from the Landsberg erecta ecotype and the Arabidopsis thaliana genome was sequenced from the Columbia ecotype, it was possible to compare the sequences and identify new polymorphisms. The genomic location of the AtRAC genes plus the revelation of large genomic duplications provided additional information regarding the evolution of the gene family in plants. A summary and discussion of these new findings are presented together with a general study of small Ras-like GTPases and their evolution in cellular organisms. This study suggests that the small GTPases in eukaryots evolved from two bacterial ancestors, a Rab-like and a MglA/Arp-like (Arf-like) protein. The MglA proteins (after the mgl locus in Myxococcus xanthus) are required for gliding motility, which is a type of movement that take place without help of flagella.

The second publication describes experiments done with the Drosophila melanogaster DRal gene and its effects on cell shape and development. Ectopic expression of dominant negative forms of DRal reveals developmental defects in eye facets and hairs, while constitutive activated forms affects dorsal closure, leaving embryos with an open dorsal phenotype. Results presented in this publication suggest that DRal act through the Jun N-terminal kinase (JNK) pathway to regulate dorsal closure, but recent findings may point to additional explanations as well. The results also indicate a close association between processes regulated by Rac/Rho and Ral proteins in Drosophila.

Essential oils (EO) are plant secondary metabolites that are known for their fragrance and food flavour properties. They consist of a complex mixture of mono- and sesquiterpenes, phenyl propanoids and oxygenated compounds. EOs can be present in different plant organs and materials, and their storage is related to specialised secretory structures. The yield of EOs from plant raw materials by distillation or pressing may on average vary from 0.1 – 1%, thus restricting the major EO production to the plant group of aromatic plants. Due to their function as signalling compounds between different types of organisms and diverse biological systems, their general antimicrobial and antioxidative effects and medicinal activity, EOs offer a promising potential for future applications within the fields of agriculture, medicine, pharmaceutical industry and biotechnology.

Changed consumer demands and raised interest in natural product compounds, especially essential oils, have formed the basis for initiating the research project “Norwegian Herb Production (Norsk Urteproduksjon NUP)” to encourage the cultivation, processing, marketing and distribution of aromatic and medicinal plants. The production, composition and quality characteristics of EOs (yield and terpene composition) from chamomile, lemon balm, oregano, peppermint, sachalinmint, thyme and yarrow have been investigated in the project period between 1994-1998.

Much focus has been put on the application of solid-phase microextraction (SPME) coupled with gas chromatography-mass spectrometry (GC-MS) for the analysis of EO volatiles from various aromatic and medicinal plants. SPME is a fast, solvent-free and non- destructive sample preparation technique where the analytes are extracted from fluid or solid matrices by headspace (HS) or direct immersion sampling (DI). Apart from EO isolation by common distillation, the applicability and sensitivity of the SPME fibre has made it feasible to carry out qualitative and semi-quantitative HS analyses of aromatic plants with regard to changes of EO metabolism during ontogenesis and plant development.

Based on NUP-results from field trials in the period between 1995-1996, the mint species peppermint (Mentha × piperita L.) and sachalinmint (Mentha sachalinensis (Briq.) Kudô) have been studied in detail (Papers B, D and E). Comparative analyses by applying distillation sampling and SPME have been carried out in order to study the advantages and disadvantages of both techniques (Papers B and E). It could be shown, that SPME offers a fast and reliable method for detecting quality-impact compounds from the p-menthane group (menthol, menthone, neomenthol, isomenthone and menthyl acetate). A distinct increase in the menthol/menthone ratio in the basipetal direction could be detected for peppermint and sachalinmint by applying SPME, thus revealing within-plant quality differences according to pharmacopeial requirements. Taking the increase of EO production from the vegetative to the generative growth stage into account, the harvest of mint plants in bloom will result in better EO yield and quality with regard to higher amounts of menthol.

When applying HS-SPME on complex EO volatile matrices such as known for yarrow (Achillea millefolium L.; Paper C), one might deal with fibre-partitioning effects of the different mono- and sesquiterpenes due to their physical and chemical properties. Despite these disadvantages, HS-SPME appears to be a sensitive extraction method for the screening of EO volatiles from complex sample matrices. Comparative analyses of volatiles from rose root rhizomes (Rhodiola rosea L.) have been carried out in order to characterize the rose-like odour compounds (Paper F). A total of 75 and 59 compounds have been identified by distillation sampling and HS-SPME, respectively, thus underscoring the excellent extraction properties and applicability of the SPME fibre.

Paper A gives a brief overview of EO biosynthesis and chemical structures, plant sources and methods of EO production. Before leading over to the main topic of HS-SPME applications by referring to numerous examples from the research work at The Plant Biocenter in the past 5 years, an introduction of solid-phase microextraction with regard to devices, procedures and extraction parameters is given.

The advantages and disadvantages of distillation vs. SPME are outlined on the background of comparative analyses of peppermint, chamomile, basil and dill. Furthermore, the utilization of HS-SPME for quantitative studies with regard to extraction time and analyte concentration is being highlighted. Examples for the screening of chemotypes (hops −Humulus lupulus L.) and cultivars (dill – Anethum graveolens L.) and ontogenetic studies are given (Mentha species; arnica −Arnica montana L.). Finally, the applicability of HS-SPME for the quality assessment of processed herbs (sweet basil −Ocimum basilicum L.) and phytomedicinal preparations (red coneflower – Echinacea purpurea L.) is being discussed.

The advantages of HS-SPME over classical distillation and headspace applications are impressive due to drastically reduced analysis time and will introduce new frontiers in plant volatile research with regard to secondary metabolism, plant-insect interactions and in vivo studies. The user-friendliness of operating SPME will initiate the development of future applications and equipment for the monitoring of volatiles for plant biological and environmental studies, extraction automation, on-site sampling and on-fibre storage of analytes.

Paper VI reprinted with kind permission of Elsevier, Sciencedirect, www.sciencedirect.com

The aims of this study were to investigate the effects of known environmental contaminants on defined behavioural variables in fish, and to discuss properties of these behavioural traits that make them useful as potential indicators of pollution.

In studying the effects of pollution, the resulting biochemical and physiological alterations are more commonly measured. However, effects of pollution can manifest itself at all levels of biological organisation, including behaviour. In this respect, behaviour can be considered a valid biomarker of pollution in that it is expected to be both susceptible to pollution and of high ecological significance, as it influences the fitness of the affected individuals.

This thesis is based on four individual studies, in which the threespine stickleback Gasterosteus aculeatus was used as a model species. Results from these studies show that antipredator behaviour, feeding behaviour, shoaling behaviour, bottom-dwelling behaviour and reproductive behaviour are all sensitive to exposure to sublethal concentrations of defined environmentally relevant chemicals.

The results showed that antipredator behaviour and fright response in threespine stickleback were impaired following exposure to sublethal concentrations of bis(tributyltin)oxide (TBTO). However, for some of the tested antipredator variables the effects were reversed after the ending of exposure. Further, it was shown that feeding motivation in fish exposed to butyl benzyl phthalate (BBP) and/or 2,2-bis(p-chlorophenyl)-1,1-dichloroethylene (DDE) was increased in that exposed fish initiated feeding more often than the controls. Exposure to BBP also caused sticklebacks to aggregate into tight shoals and to spend more time at the bottom of the aquarium compared to the control fish.

The reported significant differences between the controls and BBPexposed fish with respect to feeding and shoaling behaviour were shown even though the levels of BBP were below the analytical detection limit. Different suggested explanations, for example, too high detection limit, or degradation to its BBP metabolites are given to this result.

17β-Oestradiol (E₂) exposed male sticklebacks started nest building later than non-exposed males, but there were no differences between exposed and control males with respect to the number of males that built nests. Further, the exposed males spent less time displaying paternal care compared to the control males, although there were no differences between the two groups in the number of performed courtship displays. Because of the significant effect upon some but not all reproductive behavioural traits, it was suggested that the different variables might vary in sensitivity, implying that a variety of variables should be studied in order to obtain a more reliable evaluation of the effects of pollution.

Chemicals can cause deleterious effects at one or more levels of biological organisation, from biochemical, physiological, individual, population and through to the ecosystem levels. In contrast to the established hypothesis that a pollutant affects the different biological levels in an escalating timedependent pattern, starting at the biochemical level, it is here suggested that biomarkers at the biochemical, physiological and behavioural levels often will respond early and simultaneously in the same individual.

Whereas some biochemical responses are specifically related to one class of exposure agents and thus may act as specific indicators of pollution, most behavioural traits may be altered in response to a variety of chemicals. One exception may be alterations in reproductive behaviour caused by endocrine disrupting chemicals, due to effects of the chemicals on hormones that result in immediate reproductive behavioural effects. In spite of the specific action of some biochemical biomarkers, they are often considered to be of little ecological relevance since many of them are not related to individual fitness.

In this thesis, it is argued that behavioural variables can be employed as useful and reliable biomarkers of environmental contamination. It is also important to focus on behaviour to map and quantify the resposes. However, to reliably evaluate the effects of pollution, behavioural variables should be used in association with biochemical and physiological traits. Moreover, optimal combination of results from laboratory and field experiments would enhance the ecological relevance of the study.

All papers reprinted with kind permission of Elsevier, sciencedirect.com

This thesis deals with effects of climate on tree growth of the dominating conifer species, Picea abies (L) Karst. (Norway spruce) and Pinus sylvestris L (Scots pine), in central Norway and Fennoscandia. Both species are sampled along major environmental gradients, i.e. altitude and oceanicity, and growth responses to climate, i.e. temperature and precipitation, are examined along these gradients. Additionally, time is considered as an environmental gradient and temporal responses are carefully deciphered. Special attention is given to large-scale climate oscillation and their effect on tree growth. In the individual papers the specific aims have been to:

1. identify climate variables (all seasons) with significant influence on radial tree growth of P. abies and P. sylvestris along major environmental gradients (Paper I-IV)

2. identify if and how the growth response to climate has changed through time along these gradients (Paper I-IV)

3. make interregional comparisons of P. sylvestris growth pattern across Fennoscandia from oceanic western Norway to continental eastern Finland (Paper III)

4. analyse to what degree large-scale circulation patterns of air masses are registered in regional tree growth of both P. abies and P. sylvestris (Paper I, III and IV)

5. discuss possible effects on radial tree growth of a predicted warmer climate (Paper I, III and IV)

When the study of this thesis was initiated, hardly any work had been carried out on how plant odour information was encoded by the olfactory RNs in heliothine moths. The method of gas chromatography linked to single cell recordings (GC-SCR) was employed and improved for identifying naturally occurring plant odorants that are detected by single RNs and can be considered as biologically relevant. Three species of the subfamily Heliothinae were included in this work, the two polyphagous H. virescens and H. armigera and the oligophagous H. assulta. The American H. virescens is geographically separated from the other two species. H. armigera and H. assulta are partly sympatric in Asia and Australia.

The aims of the thesis elucidated in Papers I-IV were as follows:

1. To identify plant produced volatiles detected by antennal RNs in the three species of the subfamily Heliothinae.

2. To elucidate whether the single RNs can be classified into distinct types according to their specificity.

3. To characterise the plant odour RN types by their molecular receptive ranges, sensitivity and specificity.

4. To compare the specificity of plant odour RN types across the three related species of Heliothinae, with the aim to reveal any differences in the peripheral olfactory system that may have evolved through evolution.

The bacterial origin of mitochondria from an ancient endosymbiosis is now widely accepted and the mitochondrial ancestor is generally believed to belong to the bacterial subdivision α-proteobacteria. The high fraction of mitochondrial proteins encoded in the nucleus has commonly been explained with a massive transfer of genes from the genome of the ancestral mitochondrion.

The aim of this work was to get a better understanding of the mitochondrial origin and evolution by comparative genomics and phylogenetic analyses on mitochondria and α-proteobacteria. To this end, we sequenced the genomes of the intracellular parasites Bartonella henselae and Bartonella quintana, the causative agents of cat-scratch disease and trench fever, and compared them with other α-proteobacteria as well as mitochondrial eukaryotes.

Our results suggest that the adaptation to an intracellular life-style is coupled to an increased rate of genome degradation and a reduced ability to accommodate environmental changes. Reconstruction of the α-proteobacterial ancestor and phylogenetic analyses of the mitochondrial proteome in yeast revealed that only a small fraction of the proteins used for mitochondrial functions could be traced to the α-proteobacteria. Furthermore, a substantial fraction of the mitochondrial proteins was of eukaryotic origin and while most of the genes of the α-proteobacterial ancestor have been lost, many of those that have been transferred to the nuclear genome seem to encode non-mitochondrial proteins.

Symbiosis is a widely common phenomenon in nature and has undoubtedly contributed to the evolution of all organisms on earth. Symbiotic associations can be of varying character, such as parasitic or mutualistic, but all imply a close relationship. To study the evolution of genomes of insect endosymbionts, we have sequenced the genomes of the mutualist Buchnera aphidicola from the aphid Schizaphis graminum (Sg) and the reproductive manipulator Wolbachia pipientis strain wRi from Drosophila simulans that show strikingly different evolutionary patterns.

The comparison between the genome of B.aphidicola (Sg) and the genome of B.aphidicola from the aphid Acyrthosiphon pisum (Ap), that are believed to have diverged 50 million years ago, revealed a perfect gene order conservation and loss of only 14 genes in either of the lineages. In contrast, the rate of nucleotide turnover is very fast probably due to relaxed selection and loss of DNA repair genes. The genomic stasis observed in Buchnera was attributed to the loss of repeats and of the gene recA.

In striking contrast to the genomes of B.aphidicola, a vast amount of repeats were found in the genome sequence of W.pipientis strain wMel. The comparison between the genomes of W.pipientis strain wRi and W.pipientis strain wMel shows that a lot of rearrangements have occurred since their divergence. The massive amount of repeats might stem from relaxed selection pressure but possibly also from selection to create variability via recombination.

Comparisons between pairs of genomes from closely related bacteria showed that the stability of gene order and content is connected to an intracellular lifestyle and indicated that homologous recombination between repeats is an important mechanisms for causing intrachromosomal rearrangements. Our studies show that the lifestyle of a bacterium to a great extent shapes the evolution of their genetic material and future capabilities to adapt to new environments.

The tRNALeu (UAA) intron has been recorded in the plastid genome of many algae and land plants and was the first intron to be discovered in cyanobacteria. In all known cases it interrupts the tRNALeu anticodon loop at a conserved position (U-intron-AA). Cyanobacteria are a diverse group of photosynthetic prokaryotes, some involved in symbiotic associations with a wide range of organisms. The most studied associations are those with plants, where strains of Nostoc are the common cyanobacterial partner. In this thesis two aspects of the biology of the cyanobacterial tRNALeu (UAA) intron are focused: first, the use of the intron as a genetic marker for studying the diversity and specificity of two cyanobacterial symbiosis (bryophytes and cycads) and second, the evolutionary patterns of the intron by using the unique data set generated from the diversity analysis. From the studies, many different Nostoc strains are involved in the two symbiotic associations, although no variation was observed within a single bryophyte cavity or cycad coralloid root. Furthermore, a certain level of temporal stability in the cyanobiont composition of the bryophyte population was found and, in the cycad association different coralloid roots from a single specimen may harbor different cyanobacteria. That a minor cyanobiont could have avoided detection is still possible but unlikely. The sequence alignment of the Nostoc tRNALeu (UAA) introns reveals great sequence similarity with size variation only found in the structural element P6b. This element was found to consist of heptanucleotide repeats and of other non-repetitive genetic elements (NIS elements). The sporadic occurrence of the NIS elements indicates recent origins and a mechanism for its dispersal is proposed. In this thesis new insights are given concerning cyanobacterial symbioses and also on the mechanisms involved in the evolution of an old genetic element: the tRNALeu (UAA) intron in cyanobacteria.

Hvordan lærer og husker vi dufter? Hvordan skiller vi dem fra hverandre?

Det finnes liten kunnskap om hvilke duftsubstanser ulike lukteceller er utviklet for. I dag er gener for luktereseptorer identifisert i mange organismer, men kunnskapen om relevante duftstimuli mangler. Denne kunnskapen kan kun komme fra fysiologiske studier. I laboratoriet ble det brukt beslektede skadeinsekter som modeller for å studere innkoding av luktinformasjon i sanseceller og generelle prinsipper for luktesansens mekanismer.

Dette ble utført ved bruk av elektrofysiologiske målinger av nerveimpulser fra enkelte celler på insektantennene, med direkte kopling til kjemiske analyser av substansene avgitt av plantene. Resultatene har gitt ny kunnskap om hvilke plantesubstanser disse insektene detekterer i naturen. I tillegg har resultatene vist at luktecellene kan klassifiseres i distinkte typer, og samme type finnes hos de tre beslektede artene. Hver type er spesialisert for en enkelt substans, men de svarer også på høye konsentrasjoner av noen få andre substanser med lignende molekylstrukturer. Det er ingen overlapping av substanser mellom de ulike celletypene, noe som viser hvordan luktinformasjonen formidles via spesifikke nerveceller til hjernen hos disse insektene. Atferdsreaksjoner på en spesielt interessant substans viste at substansen økte tiltrekningen av gravide hunninsekter og økte antallet egg lagt på planter med substansen.

Å kjenne de biologiske luktesubstansene er viktig for å studere luktesansen generelt. Informasjon om hvilke plantedufter de studerte insektene lukter, kan brukes for å bekjempe skadene de påfører avlinger over hele verden.

The aim of this study was to investigate the effects of water temperature and salinity on lipid nutrition of farmed Atlantic salmon (Salmo salar L.) parr and smolt. Salmon parr were held at low water temperature (2°C) for six months while being fed feeds that differed in oil source (i.e. marine fish oil or vegetable oil blend) and concentration (low, 21% and high, 34%). The responses at low temperature were compared with those of fish held at 8°C using full-factorial design. Feeding and growth were maintained at 2°C, although at lower rates than at 8°C. Growth and feed utilisation improved over time, suggestive for a long-term acclimation response in fish held at low temperature. Overall feed efficiency was better at the lower temperature. A gradual decrease in growth rate and feed utilisation was seen at the higher temperature as the fish grew larger. The fish compensated for reduced energy density by increasing feed intake. At the higher temperature, better growth was found for fish fed the low-fat feeds, and there was also a tendency for improved growth when vegetable oil was used. Thus, there were no signs that vegetable oils are inferior to marine fish oil in promoting growth of Atlantic salmon parr in fresh water. Fish fed high fat feed were fatter than fish fed low fat feed, suggestive of lipostatic regulation of feed intake. Fat and protein digestibility were high at both 2°C and 8°C, although both fat and protein digestibility were lower at 2°C. At the lower temperature, increased dietary fat level increased the fat digestibility, and improved protein digestibility were seen when vegetable oil was included in the feed. Protein retention was higher at the higher temperature irrespective of feed treatment, indicating that proteins were both readily digested and converted into new tissues. The effects of feed treatment on low temperature acclimation responses were assessed from deposition of dietary fatty acids in fish tissues and from n-3 and n-6 essential fatty acid (EFA) budgets. Fatty acid composition of polar (membrane) and non-polar (storage) lipids in muscle, viscera and carcass were markedly influenced by the dietary oil, and non-polar lipids were more influenced than polar lipids. The retention n-6 EFAs was lower than for n- 3 EFAs, and was independent of temperature. The retention of n-3 EFAs retention was higher at the 2°C, especially amongst fish given the fish oil based diets. This may be a reflection of the importance of n-3 HUFAs during low temperature acclimation. However, the unsaturation (UFA:SFA ratio) of polar lipids was higher in fish fed the vegetable oils than for fish fed fish oil based feed. This may imply that vegetable oils produced fish that were better able to withstand exposure to low temperature, while having membrane lipids less susceptible to oxidative damage, due to the lower contents of n-3 HUFAs (mainly EPA and DHA). The six months feeding period in freshwater was followed by parr-smolt transformation, and a subsequent 42-days on-growing in seawater. Feed history during freshwater rearing influenced on-growth of smolts. A positive effect of using a vegetable oil was indicated, but this effect was only seen when there was a shift to a high-lipid fish oil based feed at the time of transfer to seawater. As such, it was evident that use of vegetable oils in freshwater feed did not interfere with low temperature acclimation or parr-smolt transformation of juvenile salmon, and subsequent on-growing in seawater was better when vegetable oil had been used in the feed. This indicates that fatty acid (lipid) requirement of Atlantic salmon are probably different in fresh water and seawater, and that these changes are linked to parr-smolt transformation. It could be speculated that that salinity may be more important than temperature as an environmental influence on the fatty acid requirements of Atlantic salmon.
Målet med dette studiet har vært å undersøke vanntemperaturens og saltholdighetens innvirkning på lipidernæringen hos parr og smolt av oppdrettet atlantisk laks (Salmo salar L.). Lakseparr ble holdt ved lav vanntemperatur (2ºC) i seks måneder mens de ble fôret med en av fire fôrtyper med ulike fettkilde (dvs. marin fiskeolje eller vegetabilsk olje) og ulik konsentrasjon (lav, 21% og høy, 34%). Responsene ved den lave temperaturen ble sammenlignet med responsene en fikk hos fisk holdt ved 8ºC i et full-faktorielt forsøksdesign. Fôrinntak og vekst ble opprettholdt ved 2ºC, men var lavere enn ved 8ºC. Over tid ble vekst og fôrutnyttelse forbedret, noe som indikerer en langtids akklimeringsrespons hos fisken ved den lave temperaturen. Totalt sett var utnyttelsen av fôret bedre ved den laveste temperaturen. En kunne observere en gradvis reduksjon i veksthastighet og fôrutnyttelse ved den høyeste temperaturen ettersom fisken ble større. Fisken kompenserte for lavere energitetthet i fôret ved å øke fôrinntaket. Ved den høyeste temperaturen var veksten bedre hos fisk fôret med lav-fett-fôrene. Det var også en tendens til forbedret tilvekst når vegetabilsk olje ble brukt. Det var ingen tegn til at vegetabilsk olje var dårligere enn marin fiskeolje til å fremme vekst hos lakseparr i ferskvann. Fisken som ble fôret med høy-fett-fôr ble fetere enn den som fikk lav-fett-fôr. Det indikerer lipostatisk regulering av fôrinntak. Fett- og proteinfordøyeligheten var høy både ved 2ºC og 8ºC, selv om både fett- og proteinfordøyeligheten var lavest ved 2ºC. Ved den laveste temperaturen, ga økt fettinnhold en forbedret fettfordøyelighet, og bruk av vegetabilsk olje i fôret ga bedre proteinfordøyelighet. Proteinretensjonen var høyere ved den høyeste temperaturen uavhengig av fôrtype, noe som indikerer at proteinet ble både lett fordøyd og omdannet til nytt vev. Effektene av fôrtype på akklimeringen til lav temperatur ble bestemt fra deponeringen av fettsyrer fra fôret i ulike vev og fra budsjetter for n-3 og n-6 essensielle fettsyrer (EFS). Fettsyresammensetningen i polare (membran) lipider og upolare (lagrings) lipider i muskel, innvoller og ’rest’ ble tydelig påvirket av oljene i fôret, og de upolare lipidene ble mer påvirket enn de polare lipidene. Retensjonen av n-6 EFS var lavere enn for n-3 EFS, og var uavhengig av temperatur. Retensjonen av n-3 EFS var høyere ved 2ºC, spesielt hos fisk som fikk et fiskeoljebasert fôr. Dette kan reflektere betydningen av n-3 HUFA fettsyrer i akklimeringen til lav temperatur. Imidlertid var de polare lipider hos fisk som ble gitt fôr med vegetabils olje, mer umettet (UFA:SFA forhold) enn hos fisk gitt fôr med marine fiskeoljer. Dette kan bety at vegetabilske oljer produserte fisk som var bedre i stand til å tåle eksponering til lav temperatur, samtidig som membranlipidene var mindre utsatt for oksidering som følge av et lavere innhold av n-3 HUFA fettsyrer (hovedsaklig EPA og DHA). Etter seks måneder i ferskvann ble fisken smoltifisert, etterfulgt av en 42-dagers periode i sjøvann. Fôrhistorie i ferskvannsfasen påvirket påvekst hos smolt. En positiv effekt av vegetabilsk olje ble funnet, men denne effekten ble bare funnet i grupper som hadde et skifte til et høy-fett-fiskeoljefôr ved overføring til sjøvann. Det var derfor tydelig at vegetabilsk olje ikke hadde negative konsekvenser for akklimering til lav temperatur eller for smoltifiseringen hos unglaks, og påfølgende tilvekst i sjøvann var bedre når vegetabilske oljer hadde blitt brukt. Dette indikerer at fettsyre (fett) behovet til atlantisk laks er forskjellig mellom ferskvann og sjøvann, og at forskjellene er knyttet til smoltifiseringen. Det kan derfor spekuleres i om saltholdigheten i miljøet er viktigere enn temperaturen i å bestemme fettsyrebehovet hos atlantisk laks.
Papers II and V reprinted with kind permission of Elsevier, sciencedirect.com.

Abstract

The sediment requirements for freshwater pearl mussel (Margaritifera margaritifera) recruitment, in 18 rivers in the counties of Västra Götaland, Örebro, Värmland and Västmanland in Sweden, were investigated. The top 4 cm of sediment in the rivers was analysed in terms of size, distribution and organic compound within the fine sediment. The aims of the study were to determine whether there is a relation between sediment particle size compound and freshwater pearl mussel recruitment as well as between organic compound in fine sediment and recruitment of mussels. The study shows that there is a significant difference in the amount of organic silt between non-recruitment and recruitment sites with a higher percentage of organic silt in recruitment sites. There is also a legible difference between the amounts of silt per sample between non-recruitment sites and recruitment sites where there was significantly more silt in sediment samples of non-recruitment sites. With the exception of fine sediment, no significant difference was found between non-recruitment and recruitment sites regarding size class distribution.

Sammanfattning

Sedimentkraven för rekrytering hos flodpärlmussla (Margaritifera maragaritifera) i 18 svenska vattendrag belägna i Västra Götalands, Örebro, Värmlands och Västmanlands län undersöktes. Vattendragens översta 4 cm sediment analyserades gällande storlek, fördelning och organisk sammansättning i finsedimentet. Målen med studien var att fastställa huruvida det finns förhållanden mellan sedimentets partikelstorleksammansättning och rekrytering av flodpärlmussla samt mellan finsedimentets organiska sammansättning och rekrytering av musslor. Studien visar en signifikant skillnad i organiskt finsediment mellan icke-rekryteringsplatser och platser med rekrytering där rekryteringsplatser hade högre procentuell andel organiskt finsediment. En signifikant skillnad påvisades också mellan andel finsediment per sedimentprov där sedimentprov från icke-rekryteringsplatser innehöll en högre procentuell andel finsediment. Förutom gällande finsediment påvisades ingen signifikant skillnad i sedimentets storleksdistribution mellan rekryterings- och icke-rekryteringsplatser.

Pseudevernia furfuracea is a shrubby lichen commonly found around the Baltic Sea. The lichen appears to reproduce mainly by producing isidia, propagules of the lichen cortex. It is very morphologically and chemically diverse and can be found on different substrates, such as nutrient poor bark trees and rocks. The main objective of this study was to describe genetic variation in the ITS region and link this to variations in morphology, substrate ecology and secondary chemistry. In total, 36 specimens of P. furfuracea were collected from 21 sites in Sweden, Finland and Estonia. Seven haplotypes were distinguished in the ITS region. A statistically significant connection between haplotype and colouration of the lichen was found. Lighter coloured specimens of P. furfuracea are more likely to be of the ancestral haplotype. No other significant correlations between the different characteristics studied were found, suggesting that P. furfuracea should be regarded as a single species within the Baltic Sea area. This is also supported by the haplotype network.

In this project, the maintenance of dynamic cycling of inorganic phosphate is discussed in terms of a phosphate transporter, ANTR3. Reverse genetics are applied with the help of bioinformatics and other web based tools which provided valuable initial information. The model organism Arabidopsis thaliana, both wild-type and mutants was cultivated hydroponically. Screening for homozygotes proceeded standardization of a protocol for isolation of plastids from the roots of these plants. Presence and absence of protein in root plastids was confirmed by western blotting in wild-type and mutants respectively. This was followed by functional and biochemical analysis of the protein by transport experiments using radioactively tagged phosphate. The development of a protocol for isolation of root plastids from roots of Arabidopsis thaliana with high yields has been successful. In-vitro studies by radioactive phosphate transport experiments were possible with the help of knock out mutants. It has been concluded that transport of Pi via ANTR3 is dependent either on an H+ or a Na+ gradient. Back exchange experiments have aided us in establishing its activity in export and import of Pi. Last but not the least, phenotypic analysis have observed larger biomass in mutants leading to the conclusion that even though other transporters are present the sink (roots) – source (leaves) balance is disturbed.

Life-like behaviors such as fission, fusion and movement can be artificially re-created exploiting highly simplified protocell systems. This thesis is mainly focused on chemotaxis protocell systems and their integration with biological systems in order to show potential future applications. 1-Decanol droplets, formed in an aqueous medium containing decanoate at high pH, become chemotactic when a chemical gradient is placed in the external aqueous environment. We investigated the behavior of these droplets, their ability to transport and deposit living and non-living objects and to interface them with biofilms. To make the artificial system compatible with natural living systems we developed a partially hydrophobic alginate capsule as a protective unit that can be precisely embedded in a droplet, transported along chemical gradients and deposited. We developed a system that was able to transport: Escherichia coli, Bacillus subtilis and Saccharomyces cerevisiae. Both bacteria survived the transport. However, yeast survived but not in a consistent and repeatable way. Next, we evolved the system to transport human cell lines. We found that A549 cells survive encapsulation but not the transport. A549 cells are in fact very sensitive to toxic 1-decanol. We however found out that this cell line secretes compounds able to decrease the surface tension and to increase the capsule-droplet affinity. Finally we discuss future solutions for the effective transport of human cells.

Life-like behaviors such as fission, fusion and movement can be artificially re-created exploiting highly simplified protocell systems. This thesis is mainly focused on chemotaxis protocell systems and their integration with biological systems in order to show potential future applications. 1-Decanol droplets, formed in an aqueous medium containing decanoate at high pH, become chemotactic when a chemical gradient is placed in the external aqueous environment. We investigated the behavior of these droplets, their ability to transport and deposit living and non-living objects and to interface them with biofilms. To make the artificial system compatible with natural living systems we developed a partially hydrophobic alginate capsule as a protective unit that can be precisely embedded in a droplet, transported along chemical gradients and deposited. We developed a system that was able to transport: Escherichia coli, Bacillus subtilis and Saccharomyces cerevisiae. Both bacteria survived the transport. However, yeast survived but not in a consistent and repeatable way. Next, we evolved the system to transport human cell lines. We found that A549 cells survive encapsulation but not the transport. A549 cells are in fact very sensitive to toxic 1-decanol. We however found out that this cell line secretes compounds able to decrease the surface tension and to increase the capsule-droplet affinity. Finally we discuss future solutions for the effective transport of human cells.

Diss. (sammanfattning) Stockholm : Stockholms universitet, 2010.
At the time of the doctoral defense, the following papers were unpublished and had a status as follows: Paper 3: Manuscript. Paper 4: Manuscript.

Direct effects of the insecticide deltamethrin on zooplankton and benthic invertebrates werestudied during an attempt to eradicate signal crayfish. In accordance with earlier studies theresults of this investigation showed that deltamethrin is highly toxic for arthropods, whileRotifera, Oligochaeta and Mollusca have a higher tolerance. This study concludes thatRotifera in treated ponds coped with the actual concentration of deltamethrin used during theeradication attempt but that they probably got a different abundance and changed compositiondue to a new situation in competition and predation. Crustacean zooplankton totallydisappeared, but approximately a month after the treatment they began to recolonise. All thetaxonomical groups of arthropods drastically decreased in abundance, with total eliminationof the most sensitive groups. The concentration of deltamethrin was not higher than that somespecies of Hydracarina and Chironomidae survived.

The effects of prey size on prey choice in different cohorts of juvenile turbot (Psetta maxima)were studied in three nursery areas at Gotland. Prey length measurements showed that gobies(Gobiidae) increased in average length during the season, while mysids (Mysidae) did not.Experiments on predation capacity of different size classes of turbot on different size classesof prey showed that juvenile turbot easily can eat gobies that are up to two thirds of their ownbody length, while the body size of turbot does not have any effect on the predation capacityon mysids. Stomach content of 217 turbots, less or equal 35 mm, was analysed to see if therewas any change in diet during the season, but there was no significant change in diet. Theoverall conclusion was that early settlers most likely have an advantage due to greater accessof alternative prey.

Varför är utbudet av lignoser så begränsat för Norrland? Vilka faktorer spelar in för en växts härdighet, och hur bedrivs och prioriteras arbetet för att bredda produktutbudet av lignoser för växtzonerna V-VIII? Anser personer inom branschen att det idag finns behov av några speciella sorters lignoser för de högre växtzonerna? Hur ser forskarna på klimatförändringar­nas påverkan på klimatet och växterna i framtiden? Detta examensarbete grundar sig på en litteraturstudie och telefonintervjuer, och har till syfte att kartlägga det arbete som gjorts och görs för ett breddat produktutbud av lignoser för Norrland. Syftet har också varit att undersöka vilka sorts lignoser det idag finns ett behov av i växtzonerna V-VIII, vilka svårigheter som finns samt undersöka vilka lignoser som några personer i branschen ser som framtidens lignoser för dessa växtzoner. Avslutningsvis har detta resulterat i några upprättade växtlistor över de lignoser som litteraturstudien och i intervjupersonerna anser vara lignoser på frammarsch eller framtidens lignoser för Norrland.

Sammanfattning

Syftet med examensarbetet var att utföra ett designförslag på en trädgård för personer med

demenssjukdom. Genom litteraturstudier och enkätundersökning har jag fått kunskap om hur

en trädgård för personer med demenssjukdom bör se ut och vad den bör innehålla. När man

utformar en trädgård för personer med demenssjukdom är inte syftet att rehabilitera, utan att

ge dem god livskvalitet. Detta kan man göra genom att skapa en trädgård med växter och

material som stimulerar sinnet. Via enkätundersökningen har jag fått möjlighet att ta del av

sådant som vårdpersonal tycker är viktigt i en trädgård för personer med demenssjukdom och

vad de tror att de boende skulle vilja göra i en trädgård. Resultaten av enkätundersökningen

och litteraturstudierna visar att olika egenskaper och karaktärer i trädgården stimulerar sinnen,

skapar välbefinnande, bättre hälsa och livskvalitet.

Examensarbetet kommer att resultera i en illustrationsplan och en växtlista innehållande

förslag på växter man kan använda sig av i en trädgård för personer med demenssjukdom.

Jag vill rikta ett tack till Benita Andersson, min handledare som har varit ett stort stöd. Min

familj som stöttat mig under den här tiden och vårdpersonalen på Solgläntan och

Skogsgläntan som tog sig tid att fylla i enkäterna som blev en viktig del i arbetet.

Abstract

 

The benthic macroinvertebrate fauna of 22 natural springs on Öland was sampled, by using a time-standarized kick/sweep sampling technique, in the end of September and early October. The aim was to determine the number of species and their abundances in the macroinvertebrate communities in springs and how/why these may change between different springs. Likewise there was a purpose to investigate possible differences between springs considering the proportions of the number of species and the abundances of the five functional feeding groups; shredders, collectors, filter-feeders, scrapers and predators. There was also an aim to investigate if the distances betweeen springs had any influence on similarity between the communities of benthic macroinvertebrates of the springs. Analysis from the springs collected material showed several interesting patterns in the number of species and their abundances when compared between springs devided into groups depending on their environmental factors such as depth and pH. Equally interesting patterns where found in the proportions of the number of species and their abundances of the functional feeding groups between different groups of springs with different environmental features such as size, depth and type of surrounding area. Results also showed that springs separated by shorter distances had a higher likeness between their communities of benthic macroinvertebrates then springs separated by greater distances.

In a city sometimes conflicts arise between either to save the species-rich vacant lots where many species thrive, or to build new buildings. Green roofs can then serve as a refuge for plants and animals that have had their natural habitat destroyed or diminished. Today we know too little about green roofs contribution to the biodiversity in the cities. We also know very little about how various types of vegetation on roof can increase biodiversity and its ability to attract different species.The aim with this study was to examine how different types of vegetation on the roofs affect the biodiversity of the invertebrate and how species-composition and number of individuals differ between the roof- and groundlevel.This study has been carried out on Augustenborg Botanical Roof Gardens in Malmo, and in an area about 1.5 kilometers away from Augustenborg. Three different types of vegetation on the roof and ground floor were selected: sedum- ruderal and grass. The sedum roof consists of a thin layer of soil where sedum species and mosses grow. Grass roof consists of a thicker layer of soil with different grasses and meadow plants. The ruderal roof consists of a thin layer of soil with plenty of rocks and gravel on top and the vegetation is varied and scarce.Grass roof had the highest biodiversity and was also the roof with the highest number of species and individuals. The thick soil on this roof serves as protection against sun and heat, and allows species to lay eggs and to find food. The grassvegetation on the ground also contained the greatest number of species and individuals and had the highest biodiversity. This is explained by its thick soil substrate and that the area is covered with a large variety of both high-and low-growing plant species which provide shelter, shade and nectar for both mobile and non-mobile invertebrates.The sedum roof has the lowest biodiversity and the highest eveness in abundance among species. The combination of plantdiversity and thin soil layer allows just a small number of species to thrive on the roof. The invertebrates consists of mainly mobile species. Many of the species found depends on nectar and pollen as a foodsource, which is abundant on the roof from early summer and autumn when the sedum species are in bloom.The ruderal roof is slightly different from the other roofs, the landscape is dry and scarce which makes it difficult for many species to survive. Ruderal roof have the least number of species and lowest biodiversity. The results

I en stad uppstår det ibland konflikter mellan att antingen spara artrika ödetomter, där många arter trivs, eller att bygga nya byggnader. Vegetativa tak kan då fungera som refuger för växter och djur som fått sitt naturliga habitat förstört eller förminskats. Idag vet man dock alltför lite om vegetativa taks påverkan på bevarandet och ökandet av biodiversiteten i städer. Man vet också väldigt lite om hur olika vegetationstyper på tak kan öka biodiversiteten på dessa tak, samt takens förmåga att attrahera olika arter.Syftet med denna studie har varit att undersöka hur olika vegetationstyper på tak påverkar den biologiska mångfalden av evertebrater och hur artsammansättningen och individantalet skiljer sig mellan de olika taken samt markplan.Denna studie har genomförts på Augustenborg Botaniska Takträdgård i Malmö samt på en ödetomt ca 1,5km därifrån. Tre olika vegetationstyper på tak- och markplan har inventerats; sedum, ruderat och gräs. Sedumtaket består av ett tunt jordlager där sedumarter (fetbladsväxter) och mossor växer. Grästaket består av ett tjockare jordlager med olika gräs- och ängsväxter. Ruderattaket består av ett tunt jordlager med mycket sten och grus ovanpå, med växtlighet som är varierad och knapp.Grästaket hade högst biodiversitet av taken och var också det tak med flest arter och individer. Det tjocka jordsubstratet fungerar som ett skydd mot sol och värme samt gör det möjligt för vissa arter att lägga ägg och för näringssök. Flest arter och individer inventerades på gräsvegetationen på markplan och var det habitat på markplan med högst biodiversitet. Det tjocka jordsubstrat samt att området är täckt av en stor variation av både hög- och lågvuxna växtarter ger skydd, skugga och föda i form av pollen och nektar åt både mobila och icke mobila evertebrater.Sedumtaket var det tak med lägst biodiversitet och högst jämvikt. Sedumtakets kombination av ensidigt växtdiversitet och tunt jordsubstrat gör att mindre antal arter trivs på taket. De evertebrater som hittades bestod mestadels av mobila arter. Många av dessa arter är beroende av nektar och pollen som födointag, vilket det finns gott om på sedumtaket från försommaren och början av hösten när sedumarterna blommar.Ruderattaket skiljer sig något från de andra taken och områdena på markplan, landskapet är torrt och knappt vilket gör det svårt för många arter att överleva. Av de vegetativa taken har detta tak minst jämvikt och lägst biodiversitet, det var även det tak med minst antal arter.Resultaten av denna studie visar på att den takvegetation som hyser flest arter och individer samt har högst biodiversitet, är grästaket. Dock har andra arter hittats på sedum- och ruderattaken än på grästaket. De olika vegetativa taken kompletterar varandra alltså ur en biodiversitetssynvikel, eftersom de innehar en stor variation i artsammansättningen.En kombination av alla tre tak är därför den bästa lösningen för att få en så blandad biodiversitet som möjligt.

The freshwater pearl mussel Margaritifera margaritifera is an endangered species. To survive, the young mussels demand a fairly coarse bottom material containing an appropriate quantity of organic substrate to survive without suffocating. In order to estimate if a bottom is suitable for juvenile mussels, samples of the sediment are needed. To obtain samples a sampling device called the Mulv collector has been developed within this project. Bottom samples were collected from 18 stations in 4 south Swedish streams, Vramsån, Kling-storpsbäcken, Brönnestadsån and Bräkneån. No rejuvenation of the mussel was found at the stations containing more than 25% fine material.

Människan har brukat jorden sen många tusen år tillbaka. Förmågan att förändra

odlingslandskapet och påverka dess utseende och innehåll har dock varit störst efter andra

världskriget. Många av jordbrukslandskapets arter är synantroper dvs. att de direkt eller

indirekt är beroende av människan för sin existens. Dessa arter har varit människans

följeslagare i tusentals år. Åkerogräsen har kunnat öka och finna goda tillväxtchanser i

dåtidens odlingslandskap men efter andra världskriget ökade mekaniseringen och

användandet av herbicider och konstgödning i det traditionella jordbruket, vilket snabbt

förändrade förutsättningarna för åkerogräsen. Åkerogräsen är idag i stor utsträckning hotade

på grund av dagens rationella jordbruk. Olika arter är hotade på grund av olika faktorer vilket

kunnat härledas i forskning kring de hotade åkerogräsen.

Medvetenheten om det ökade hotet mot den biologiska mångfalden har ökat och intresset för

vårt biologiska arv bland allmänheten blir allt större. Dessutom har politiska beslut påverkat i

rätt riktning och slagit vakt om den biologiska mångfalden. Idag har olika bevarandeformer

för åkerogräsen skapats bl.a. Projekt Allmogeåker. Det är ett projekt som syftar till att bevara

och förbättra ogräsarternas förutsättningar. Andra alternativ för bevarande är blomsteråkrar,

rätt skötsel av värdefulla vägkanter och viltåkrar. I det moderna jordbruket kan åkerogräsen

bevaras med hjälp av jordbrukspolitiken i form av miljöstöd och specialstöd. Problematiken

kring åkerogräsens situation är idag aktualiserat i och med att ett nytt Åtgärdsprogram för

bevarande av Rödlistade Åkerogräs håller på att utarbetas.

Vårt syfte med rapporten är att praktiskt tillämpa de rekommendationer2 som Roger Svensson,

Marita Wigren-Svensson och Torleif Ingelög har satt upp i boken ”Hotade åkerogräs, biologi

och bevarande i Allmogeåkrar” och sedan utvärdera denna allmogeåker med två olika

spannmålsgrödor och olika rödlistade åkerogräs. Utifrån detta har vi arbetat med följande

frågeställningar:

• Hur ser situationen ut för de hotade åkerogräsen?

• Vad är anledningarna till dessa förhållanden?

• Vad är orsaken till skillnaderna i grobarhet hos de olika åkerogräsen?

• Vad beror skillnaderna i grobarhet på vad gäller korn kontra råg

• Är allmogeåkrar en framtida bevarandeform för de hotade åkerogräsen?

• Finns det andra alternativ för att bevara åkerogräsen?

Uppsatsen bygger på dokumentation av vår anlagda allmogeåker i Övarp, i nordvästra Skåne.

Dokumentationen har pågått från april 2004 till maj 2005. Vi har studerat olika faktorer som

kan ha påverkat resultaten och diskussionen bygger på våra resultat och erfarenheter utifrån

dessa. Några faktorer är väder, viltskador, markförhållande, olika egenskaper hos grödorna

och åkerogräsen. Vår sammanställning har gett resultat som kan tolkas utifrån specifika

faktorer snarare än allmängiltiga teorier. Resultatens svårighet är dess jämförbarhet.

Problemet är dels att det saknas liknade studier och dels att varje allmogeåker är unik genom

sina olika förutsättningar och egenskaper. Därför vore vidare studier på allmogeåkern i Övarp

en önskvärd uppföljning för att producera ett jämförbart material. Resultaten visar på hur de

specifika arternas unika egenskaper slår igenom trots en anpassad miljö som gynnar tillväxten

av åkerogräs. Vår resultatdiskussion kan därmed ses som en vägledning i att anlägga

allmogeåkrar eller liknande miljöer.

Klimatförändringar i världen är ett stort problem där alla måste hjälpa till för att stävja dess inverkan på vår livsföring. Ett problem är utsläppen av växthusgaser där djurhållningen står för en viss del. Vid djurhållning sker det en avgång av metangas både genom matsmältning och genom gödselproduktion där endast den sistnämnda är påverkbar till en rimlig kostnad. För att beräkna avgången av metan från djurhållningen i Helsingborgs stad måste man göra en inventering av djurantalet. Ett bra sätt för att utvinna metangas ur gödseln är att röta den och sedan förbränna den till koldioxid och vatten. Även koldioxid är en växthusgas men metan bidrar 21 gånger mer till växthuseffekten än koldioxid. Det som blir kvar efter rötningen är en god växtnäring med ett större växtvärde än stallgödsel. Om en lantbrukare investerar i en biogasanläggning kan detta innebära stora energivinster respektive miljövinster. Det som är viktigt att tänka på är anläggningens storlek i förhållande till energianvändningen på lantbruket. Investeringskostnaden är stor men vinsten blir positiv för en stor djurproducent.

Miljövinsterna är många, minskning av växthusgaser och mindre övergödning vilket även är bra för ekonomin.

This bachelor’s project deals with both the problems of high water temperatures in fishponds at a fish-breeding station and of the nutrient load to nearby lakes and streams in Harasjömåla, Blekinge, Sweden. Theory, methods and results of the analyses are presented in the report.

The sub-tropical climate in Namibia, together with nutrients in the water, creates a good environment for phytoplankton, especially cyanobacteria. Many of these produce toxins that can be harmful to people and animals. One of the algal toxins is microcystin. This toxin is hepatotoxic, i.e. the primary toxic effect is on the liver. Cases of gastro-enteritis, nausea, vomiting, diarrhoea, muscle weakness and paralysis have been associated with the consumption of water containing high numbers of blue-green algae all over the world.

The aim of this study was to chart the possible linkages between algae toxins in drinking water and related illnesses in Windhoek. The results showed an annual seasonal variation in gastrointestinal problems and high levels of liver-enzymes. It also showed a relationship between the concentration of chlorophyll-a in the drinking water and the cases of people suffering from diarrhoea.

Det Svenska miljömålet om återföring av växtnäring till produktiv mark, har gjort att ett initiativ till certifieringsregler för återföring av avloppsslam tagits fram. Som en viktig del i dessa certifieringsregler krävs det att slammet måste vara hygieniserat. På centrala reningsverket i Kristianstad vill man använda sig av termofil rötning som hygieniseringsmetod. Termofil rötning innebär en höjning av temperaturen i rötkamrarna med ca 19 °C.

Denna rapport syftar till att göra en jämförelse av energiutbyte och ekonomi vid olika driftsbetingelser för rötkammaranläggningen.

I rapporten ingår energibalans som inkluderar uppvärmning av slammet, värmeförluster från rötkammarens väggar, samt energiinnehållet i den producerade rötgasen. En jämförelse görs mellan alternativen mesofil och termofil rötning, samt mellan nuvarande uppvärmning och tilläggsisolering av rötkamrarna. Termofil rötning innebär ett ökat energibehov beroende på uppvärmning och värmeförluster, eftersom en högre temperatur erfordras än vid mesofil rötning. Resultaten visar att rent energimässigt skulle det bästa alternativet vara isolera rötkamrarna och behålla mesofil rötning. Resultatet baseras på att gasproduktionen förblir den samma vid termofil rötning. Om gasproduktionen skulle öka med mer än 14 % vid termofil rötning, blir alternativet med termofil rötning och tilläggsisolering det mest lönsamma alternativet från energisynpunkt.

Sammanfattning

Syftet med rapporten var att ta reda på hur förskolan anpassar lärandesituationer för barn i behov av Alternativ och Kompletterande Kommunikation (AKK) samt hur AKK används vid naturkunskapsundervisning. Metoderna för rapporten är observation och intervjuer. Jag sökte information via Internet, litteratur och rapporter. Huvudresultatet av rapporten visar att förskolan arbetar med tecken som stöd, objekt, gester, ord, bilder, sinnen och Karlstadmodellen. Undervisning sker i naturliga situationer och enskilt barn – pedagog. Pedagogers utbildning, fortbildning och handledning är mycket viktig för barnets språkutveckling. Slutsatser är att pedagoger skall vara pålästa och kunniga i barnets AKK för att tolka barnet och förmedla situationer som uppstår under en dag. Språktester hjälper barn att hitta lämplig AKK. Pedagogen skall vara och lära tillsammans med barnen i aktuella situationer samt låta barnen praktiskt prova och undersöka med sina sinnen, barnen bör även ha distans till oss vuxna ibland, en vrå att dra sig undan i.

Nyckelord: AKK, förskolan, naturkunskap, undervisning

Syftet med detta arbete var att undersöka huruvida trevärt aluminium, Al3+, inverkar på nitratupptaget hos veteplantor (Triticum aestivum L.). Vidare avsågs att undersöka om koncentrationen av jonen ifråga är av betydelse. Hypotesen som testades var att trevärda aluminiumjoner verkar hämmande på nitratupptaget och att hämningsgraden stiger med ökad koncentration av aluminium. I försöket användes veteplantor som togs i bruk på sjunde dagen efter det att de planterats i vermikulit. Provlösningarna utgjordes av fyra stamlösningar som endast skilde sig åt med avseende på aluminiumjonskoncentrationen. I en av lösningarna fanns inget tillsatt aluminium och i de andra förekom aluminium i 3, 12 respektive 24 μM. Halten nitrat var densamma i alla lösningarna och uppgick till 645 M. Plantorna fick stå i provlösningarna med genomluftning under 16 timmar. Provlösningarna analyserades spektrofotometriskt. För att tömma apoplasten fick plantorna stå i destillerat vatten under 20 minuter. Sedan torkades plantorna i 5 timmar varefter de vägdes. Resultaten visade på signifikant skillnad mellan referens och 3 μM Al relativt 12 respektive 24 μM Al. Nitratupptaget var signifikant lägst i 24 μM Al och näst lägst i 12 μM Al. Ingen signifikant skillnad kunde påvisas mellan referens och 3 μM Al. Försöket indikerar att Al3+ har en hämmande verkan på nitratupptaget hos det veteslag som här har använts och att denna hämning tilltar med stigande koncentration av Al3+ i lösningen över de koncentrationer som brukats i denna studie.

The aim of the study was to investigate whether Al3+ affects the uptake of nitrate in wheat seedlings (Triticum aestivum L.). Furthermore the aim was to investigate if the concentration of the ion had any importance. The hypothesis at trial was that Al3+ has an inhibiting effect on the nitrate uptake and that the effect increases with elevated concentrations of aluminium. In the trial wheat seedlings were used on the seventh day after being planted in vermiculite. The test solutions were four stem solutions which only differed in the aluminium concentration. In one of the solutions there was no aluminium added. Further on aluminium were used at 3, 12, and 24 micro molars. The nitrate level was the same in all solutions and the amount was 645 μM. The plants were kept in the test solutions for 16 hours with aeration. The test solutions were analyzed spectrophotometricaly. The apoplast was empted by placing the plants in distilled water for 20 minutes. Afterwards the plants were dried for 5 hours and then weighed. The result showed significant difference between the reference and 3 μM Al in respect to 12 respectively 24 μM Al. The nitrate uptake was significantly lowest in 24 μM Al and second lowest in 12 μM Al. No significant difference could be shown between reference and 3 μM Al. The study indicates that Al3+ has an inhibiting effect on the nitrate uptake of the wheat type which been used here and that the inhibition increases with elevated concentrations of Al3+ in the solutions over the range of concentrations used in this study.

Abstract

Surface-water includes different kinds of pollutants from traffic and roads. To prevent these pollutants to reach nearby lakes one can construct surface-water ponds on locations with heavy traffic. At Bergviks shopping centre in Karlstad, two ponds, one smaller and one bigger has been constructed in order to decrease the pollutant pressure from the receiving waters of Kattfjorden. Several heavy metals are essential for plants and animals in low concentration but when they occur in higher concentrations, they become toxic to the organism. The larger pond at Bergviks shopping centre has a sedimentation function so the heavy metals sink to the bottom thereby not releasing directly in to Kattfjorden. In this specific pond, plants such as reed, reed mace and broad-leafed pondweeds are the most common plants. Several studies show that plants have the ability to accumulate and store heavy metals. Reed, reed mace and broad-leafed pondweeds in the surface-water pond at Bergviks shopping centre all contains arsenic, lead, cadmium, chrome, cobalt, copper, nickel and zinc. The results in this study show a significant difference between these three plants in their heavy metals concentration. Broad-leafed pondweed had significantly higher concentrations of chrome, cobalt, copper, nickel, vanadium and zinc than reed and reed mace. Cadmium, copper and zinc also occurred in higher concentrations in broad-leafed pondweeds than in the sediment of the pond. Broad-leafed pondweed has the ability to accumulate heavy metals directly from the water while reed and reed mace only accumulate heavy metals with their roots. This could help explain the higher concentration in broad-leafed pondweed, in comparison to reed and reed mace. Due to the high metal concentration in the broad-leafed pondweed, it is appropriate to put this plant in surface-water ponds, in order to elute the water from heavy metals. Regular harvesting of the broad-leafed pondweed from the surface-water pond, together with regular cleaning of the sediment may reduce the occurrence of heavy metals in the recipient of Kattfjorden.

I min undersökning har fem pedagoger genom strukturerade intervjuer fått svara på frågor om utevistelsen på förskolan. Syftet var att ta reda på vad pedagogerna själva hade för tankar och syften bakom utevistelsen, samt hur de arbetade med detta. Frågorna gällde både vistelsen i den planerade miljön på gården och i naturen.

Pedagogerna fann mestadels fördelar med utevistelse på förskolan. Några av fördelarna som nämndes var god motorikträning och social träning. Sedan belystes även vikten av ”frisk luft” och att pedagogerna upplevde barnen som piggare om de vistades utomhus emellanåt.

Minst en gång om dagen går de ut med barnen på gården och de flesta försöker komma iväg till skogen en gång i veckan. En nackdel kan vara avbrott under leken inomhus för att man ska gå ut.

Pedagogerna framhåller i sina syften att de vill förmedla kunskap om naturen på ett lekfullt sätt för att stimulera barnens nyfikenhet genom utevistelsen.

Nyckelord: Lekfullt, nyfikenhet, pedagogers syften, utevistelse

The main purpose of this study was to examine the knowledge in biology by immigrant pupils. My investigation is based on the pupil and I have focused on positive and negative factors that affect their performance in biology.

The study is based on marks in year 2006/2007, a survey and interviews made with four immigrant pupils at a compulsory school in Västra Götaland.

The study indicates that the result in biology of immigrant pupils is lower compared to Swedish.

Difficulties in language, the commitments by their parents and their surroundings are the main factors that affect their results negative.

One of the importent things that preschool has to learn are to treat each other as different individuals. That´s why It´s sp importent that we as pedagogues are aware of the fact that boys and girls are treated different so we can act of our experiences and learn to concentrate on the childrens individuals. We as adults have to set a good exampel.

The aim of this stydy was to find out if the pedagogues treat the children different because of their gender. The purpose was also to se if there were any differences when the children were indoor or outdoor. This study is based on eight observations at two preschools in different activities outdoor  and indoors the preschool. I have also intervjued the pedagogues to find out what they think about genderdifferents and if they belive that they are teating the children different.

The result showed that the children were treated different because of their gender. The pedagogues were not aware of there act. The survey also showed that the boys got a whole lot more attention compared to the girls. This result were not different depending on if the children were outdoor or indoors.

Keywords: enviroment, equility, gender, preschool.

The present study aimed at assessing possible gender differences in human olfactory detection thresholds for three odorants; bourgeonal, an aromatic aldehyde, helional, a structural analogue of bourgeonal,  and n-pentyl acetate, an aliphatic ester. A total of 500 subjects, 250 males and 250 females between 18 and 40 years of age, were tested using a triangular forced choice method with an ascending staircase procedure. The subjects were asked to sniff the contents of three bottles and to identify the one containing the stimulus presented at a given concentration. Males were found to have a significantly lower olfactory detection threshold for bourgeonal compared to females (3.4·10¹¹ molecules·cm^-3 air and 5.9·10¹¹ molecules·cm^-3 air, respectively) whereas no significant gender difference in the olfactory detection thresholds for helional (1.4·10¹³ molecules cm^-3 air and  1.3·10¹³ molecules·cm^-3 air, respectively) or n-pentyl acetate (1.4·10¹⁴ molecules·cm^-3 air and  1.1·10¹⁴ molecules·cm^-3 air , respectively) were found. This is the first study ever to report a human male superiority in olfactory sensitivity for a monomolecular odorant. One possible explanation for this finding is that bourgeonal may differ in its biological significance for males and females. It has recently been demonstrated that bourgeonal elicits chemotaxis in human sperm cells and olfactory receptors activated by bourgeonal might thus be subject to sexual selection.

Temporal and spatial variation in the environment can influence the performance of individuals in wild ungulate populations. Of particular importance is an understanding of the mechanisms that shape variation in individual body mass, because several important life history traits are directly related to body mass. Body mass is one of the first traits that is influenced by environmental variation, and often the effect operates through variation in the components of the foraging niche of ungulates. In this thesis, I aim to demonstrate how measurements of environmental variation relate to variation in the foraging niche of ungulates. Furthermore, I aim to explore how variation in ungulate life history traits relates to these variables, and finally, how the management of ungulates could benefit from the incorporation of knowledge about the effects of environmental variation on population dynamics. I use weather observations, large-scale climate indices, and indices of environmental phenology based on satellite-derived vegetation indices (NDVI) to analyse the effect of environmental variation on plants and body mass in moose (Alces alces) and roe deer (Capreolus capreolus) populations.

The environmental variables that explained most of the variation in plant performance, measured as radial growth in common juniper (Juniper communis) also explained variation in ungulate body mass. These variables were related to conditions in spring and early summer. Plant growth was low in cold summers, and in spring where the green-up curve as measured by change in photosynthetic activity during spring was moderate. Such growing conditions are recognised to increase the quality of the plants as forage for ungulates. Consequently, moose body mass in autumn showed the opposite pattern than juniper to environmental conditions, indicating that quality of plants, rather than the quantity, is an important component in temperate ungulate foraging niche. Further, regional variation in moose body mass was associated with environmental variables related to forage quality. Roe deer body mass was associated with availability of forage during winter, and not with factors related to summer conditions. Factors related to forage quantity neither influenced temporal nor spatial variation in body mass in the two species.

Accordingly, it appears that both weather observations and satellite-derived vegetation indices are able to effectively predict variation in plant performance related to variation in foraging conditions for ungulates. The variation in forage quality in space and time created variation in body mass between populations and between cohorts within a population. Further, the variation in body mass between moose population, caused by variation in the foraging conditions, predicted how the populations differentially respond to the effects of environmental stochastisity. In populations with a high mean body mass, or a low density relative to plant biomass production, available resources buffered environmental stochastisity, and were less influenced by environmental variation than populations with relatively fewer resources available.

If wildlife managers fail to incorporate the effects of environmental variation on population performance, e.g. on the recruitment rate, the population may show unexpected and large fluctuations in size. Therefore, managers should attempt to incorporate knowledge of recent environmental conditions on the population when setting harvesting quotas.

In face of the large variation in environmental conditions experienced by the ungulate populations in Norway, and the fact that responses to environmental variation varies between populations, management should be regionally adapted, and aim to incorporate variation in vital rates caused by environmental conditions. This is likely to create more stable and predictable populations. In face of the predicted climate and landscape changes in Norwegian forests, environmental variables, e.g. from satellite-derived vegetation indices, have the potential to be a powerful tool for a sustainable management of ungulate populations. Consequently, such information should be incorporated into the management of ungulates in order to a) obtain a management of ungulate populations that is adapted to regional mechanisms of environmental variation, and b) acquire a management that is sustainable in face of future change in climate and landscape that may vary regionally. This calls for a regional differentiation in management strategies.

In the present thesis, levels of polychlorinated biphenyls (PCBs), some chosen organochlorine pesticides (OCPs), polybrominated diphenyl ethers (PBDEs) and hexabromocyclododecane (HBCD) were analyzed by gas chromatography in the yolk sac of newly hatched chicks of European shag (Phalacrocorax aristotelis), kittiwake (Rissa tridactyla), Brünnich’s guillemot (Uria lomvia) and common eider (Somateria mollissima) from the Norwegian coast and Svalbard. Levels of vitamin A (retinol), retinyl palmitate and vitamin E (α-tocopherol) were measured in plasma and liver of the hatchlings using high-performance liquid chromatography (HPLC). Using statistics, possible significant relationships between levels of the persistent organic pollutants (POPs) and vitamin levels were examined. Hence, the study aimed to elucidate retinoids and tocopherol as potential biomarkers of POP exposure. An exposure study on domestic duck (Anas platyrhynchos) eggs was also conducted to assess the effects of 2,2’,4,4’,5-pentabromodiphenyl ether (PBDE-99) on vitamin levels under controlled laboratory conditions.

There were significant differences in POP levels between the bird species included in the present study. In general, kittiwake hatchlings had higher levels of POPs than the other species, followed by shag, Brünnich’s guillemot and common eider hatchlings. Levels of organochlorine compounds in the hatchlings seemed to be higher than reported in sea bird eggs from the Canadian Arctic but lower than reported in eggs of other seabirds from the Netherlands, the Baltic, the Great Lakes and Japan. In contrast to this, the levels of PBDEs and HBCD seemed to be high in some of the species (kittiwakes, shags) relative to a European scale.

Negative relationships were revealed between POPs and morphology in Brünnich’s guillemot hatchlings, indicating that this species may be more responsive with respect to effects of POPs on morphological variables than the other species included in the present study. The importance of considering possible confounding impacts of lipid content when studying effects of POPs on morphological variables was emphasized in shag hatchlings.

The study revealed negative correlations between POPs and liver tocopherol levels in domestic duck and shag hatchlings. In Brünnich’s guillemot hatchlings, liver tocopherol levels also were negatively associated with POPs, but the relationships were less strong when the effect of body mass on tocopherol levels was accounted for. In kittiwake and common eider hatchlings, however, there seemed to be a positive influence by POPs on tocopherol levels. Thus, the results should encourage further research on the effects of POPs on tocopherol levels (including oxidized forms of the vitamin).

In shag hatchlings, negative relationships between POPs and plasma retinol levels were observed, in line with several previous studies on birds. Since retinol was not influenced in any other species included in the study, tocopherol levels might be more responsive than retinol levels to POP exposure. Additional studies should, however, be conducted before certain conclusions are drawn.

Concerning the work needed for further development of vitamins as biomarkers of POP, effort should be done to characterize confounding factors, such as diet and condition of the avian mothers. Although there was no obvious link between the observed responses of vitamins to POP exposure and effects at higher biological levels (i.e. reproduction disturbances, population decline), the relevance of vitamins as potential biomarkers of POP exposure should not be repelled.