Forest management practices have changed the over-all structure of the Fennoscandian forest landscape resulting in a lack of suitable substrates for many wood-inhabiting species. The objectives of this thesis was to describe the colonization patterns of wood-inhabiting fungi, including the potential role of beetles as dispersal vectors, on different types of dead wood substrate and assess the importance of active measures in the forest landscape in order to restore biodiversity i.e. to increase the amount of dead wood and the use of restoration fire. The results clearly demonstrate the importance of restoration fire for wood-inhabiting fungi in a dry Pinus sylvestris forest. The general pattern for the majority of the species was a drastic decline the first two years after fire. However, after four years most of the species had recovered and were frequently found on logs strongly affected by the fire. The early fungal colonization patterns on fresh experimental Picea abies logs revealed no differences between managed forest stands and stands associated with nature reserves. After five years the species assemblage on the experimental logs was affected by stand age, forest site type, and distance to forest reserves. However, very few red-listed species colonized the logs in spite of being fairly common in the reserve stands. We conclude that the experimental period of only five years was too short to fully evaluate the possibilities to use experimental logs for threatened and red-listed species. We assessed the colonization patterns of different fungal functional groups based upon their different nutritional strategies namely mycorrhizal, saprotrophic on litter and humus, saprotrophic on wood causing white rot, and saprotrophic on wood causing brown rot. The results show that the fungal community undergoes a marked change in dominant nutritional strategies during the initial stage of the colonization process both after fire disturbance and on fresh un-colonized experimental logs. To which extent, saproxylic beetles are involved as passive or active vectors in the dispersal and colonization of wood-inhabiting fungi occurring on dead wood is poorly understood. The results clearly showed that some beetle species do discriminate between different fungal substrates and in particular, the bark beetle Dryocoetes autographus showed significant preference for wood with Fomitopsis rosea mycelium.

Seed heteromorphism related to chasmogamous (CH) and cleistogamous (CL) seeds can have different ecological significance in species with different functional characteristics, competitive ability and palatability. Punagrass [<i>Achnatherum brachychaetum </i> (Godr.) Barkworth], an invasive, perennial grass is common in grasslands of Argentina and it is an aggressive weed in other parts of the world. <i>Flechilla grande</i> [<i>Nassella clarazii</i> (Ball) Barkworth] is a palatable perennial grass associated with the dominant "climax" vegetation in grasslands of Argentina. Seeds of the two grasses were collected from grasslands of Argentina, and growth chamber and greenhouse experiments were conducted to determine: 1) germination, dormancy breaking, and mass of CH and CL seeds of the two species 2) effects of contrasting range condition on germination and seed mass of punagrass, 3) the relative fitness of plants from CH and CL seeds, 4) if contrasting range condition affect fitness of CH plants of punagrass, and 5) the effect of maternal nutrient environments on CH and CL seeds and on fitness in the two species. Small CH seeds of high dispersal potential were less dormant than large CL seeds of low dispersal potential in punagrass. CH and CL seeds of flechilla grande had similar mass, germination, and response to dehulling. CL seed size and CL seed production of punagrass increased with good range condition. Increasing the maternal, nutrient environment enhanced germination of CH seeds, CL seed size, growth rate, development, biomass and seed production more in punagrass than flechilla grande. Under low nutrient conditions, flechilla grande produced a few large CH seeds. CH progeny of punagrass grew fast and developed rapidly as compared to CL progeny, which in turn produced many CH seeds. CH and CL seeds of flechilla grande had similar contribution to the fitness of adult plants. In both species, the ecological significance of having seed heteromorphism is that sibling competition is probably reduced by having more diverse offspring. Heavy grazing of competitive species such as flechilla grande may favours species as punagrass with many small CH seeds, high potential for colonization as well as large CL seeds for persistence in the seed bank and seedling competition.

Seed heteromorphism related to chasmogamous (CH) and cleistogamous (CL) seeds can have different ecological significance in species with different functional characteristics, competitive ability and palatability. Punagrass [<i>Achnatherum brachychaetum </i> (Godr.) Barkworth], an invasive, perennial grass is common in grasslands of Argentina and it is an aggressive weed in other parts of the world. <i>Flechilla grande</i> [<i>Nassella clarazii</i> (Ball) Barkworth] is a palatable perennial grass associated with the dominant "climax" vegetation in grasslands of Argentina. Seeds of the two grasses were collected from grasslands of Argentina, and growth chamber and greenhouse experiments were conducted to determine: 1) germination, dormancy breaking, and mass of CH and CL seeds of the two species 2) effects of contrasting range condition on germination and seed mass of punagrass, 3) the relative fitness of plants from CH and CL seeds, 4) if contrasting range condition affect fitness of CH plants of punagrass, and 5) the effect of maternal nutrient environments on CH and CL seeds and on fitness in the two species. Small CH seeds of high dispersal potential were less dormant than large CL seeds of low dispersal potential in punagrass. CH and CL seeds of flechilla grande had similar mass, germination, and response to dehulling. CL seed size and CL seed production of punagrass increased with good range condition. Increasing the maternal, nutrient environment enhanced germination of CH seeds, CL seed size, growth rate, development, biomass and seed production more in punagrass than flechilla grande. Under low nutrient conditions, flechilla grande produced a few large CH seeds. CH progeny of punagrass grew fast and developed rapidly as compared to CL progeny, which in turn produced many CH seeds. CH and CL seeds of flechilla grande had similar contribution to the fitness of adult plants. In both species, the ecological significance of having seed heteromorphism is that sibling competition is probably reduced by having more diverse offspring. Heavy grazing of competitive species such as flechilla grande may favours species as punagrass with many small CH seeds, high potential for colonization as well as large CL seeds for persistence in the seed bank and seedling competition.

Plant growth-promoting bacteria (PGPB) have been studied in many agriculturally interesting plants, but never in pitcher plants. Sarracenia oreophila (the green pitcher plant) is an endangered species in Georgia, Alabama, and North Carolina (Rice 2010). With the help of Dr. Jim Spain's lab, a previous student in Dr. Gerald Pullman's lab discovered evidence that nitrogen-fixing bacteria (Burkholderia spp.) live within these pitcher plants. This study aims to determine whether these nitrogen-fixing bacteria confer a benefit to their host plants by providing fixed nitrogen. To do this, pitcher plants were inoculated with the Burkholderia and grown on a control medium, a medium without sugar (as the sugar causes the bacteria to grow until they hinder the plants), various media that are missing nitrogen-containing compounds usually provided in growth media, and a medium completely lacking nitrogen. These plants were compared to control plants on the same media that had not been inoculated with Burkholderia. The plants' biomass and root growth were measured. The data suggest that Burkholderia may stimulate plant biomass growth when sufficient nitrogen is present and there may be a nitrogen-threshold that needs to be met in order to sustain the Burkholderia-Sarracenia symbiosis. Also, the Burkholderia has a negative effect on roots grown in high-nitrogen media, possibly due to competition for nutrients.

No description available.

Parasitism in plants is often accompanied by a suite of morphological and physiological changes resulting in a condition known as the ‘parasitic reduction syndrome’. With changes including extreme vegetative reduction, frequently beyond any resemblance to its photosynthetic relatives, accompanied by significant losses of genes linked to photosynthesis, the study of parasitic plants can be challenging. Conopholis (Orobanchaceae) is a small holoparasitic genus distributed across eastern and southwestern North America and Central America. This genus has never been the subject of a molecular phylogenetic or morphometric analyses. In addition, very little is known of the relationships among populations and of their post-glacial history. To investigate the species limits and phylogenetic relationships in Conopholis, we conducted a comprehensive molecular phylogenetic study of the genus as well as a fine-scale morphometric study. Based on plastid and nuclear sequences, Conopholis was found to contain three distinct and well-supported lineages which have varying degrees of overlap with previously proposed taxa. The clustering and ordination analyses of the morphometric study corroborated the molecular data, demonstrating the morphological differentiation between the three lineages detected within Conopholis. A taxonomic re-alignment is proposed for the genus that recognizes three species, C. americana, C. panamensis, and C. alpina. To address genetic diversity and phylogeographic structure of C. americana in eastern North America, microsatellite markers were developed and characterized for the first time in this species. Using these newly generated markers along with sequences from the plastid genome, the persistence of a minimum of two glacial refugia at the last glacial maximum were inferred, one in Florida and southern Alabama and another in the Appalachian Mountains near the southern tip of Blue Ridge Mountains. The diversity seen across the southern Appalachian Mountains supports the hypothesis that populations derived from the southern and northern refugia come together in this area.

This dissertation is an ethnography of the cultural politics of Indian/white relations in a small, interior British Columbia resource city at the height of land claims conflict and tensions. Drawing on the theoretical approaches of Nicholas Thomas (1994) and Raymond Williams (1977, 1980), I show how the power that reinforces the subordination of aboriginal peoples in Canada is exercised by 'ordinary' rural Euro-Canadians whose cultural attitudes and activities are forces in an ongoing, contemporary system of colonial domination. In approaching these issues through in-depth ethnographic research with both the Native and Euro- Canadian populations and in exploring the dynamics of cultural domination and resistance at the level of a local, rural community, this dissertation stands as a unique contribution to the ethnographic study of colonialism and Native/non- Native relations in Canada. The dominant Euro-Canadian culture of the region is defined by a complex of understandings about history, society and identity that is thematically integrated through the idea of the frontier. At its heart, the frontier complex consists of an historical epistemology - a Canadian version of the American frontier myth (Slotkin 1992) - that celebrates the processes through which European explorers 'discovered' and 'conquered' North America and its aboriginal inhabitants, . Central to this complex is the Indian/white dichotomy, a founding archetype in Euro-Canadians' symbolic ordering of regional social relations and in their private and public constructions of collective identity. Also central is the Euro-Canadians' self-image of benevolent paternalism, an identity that appears repeatedly in discourses of national history and Native/non-Native relations. Facets of the frontier complex are expressed in diverse settings: casual conversations among Euro-Canadians, popular histories, museum displays, political discourse, public debates about aboriginal land claims, and the town's annual summer festival. In each setting, these practices contribute to the perpetuation of relations of inequality between Euro-Canadians and area Shuswap, Tsilhqot'in and Carrier peoples, and in each setting area Natives are engaging in diverse forms of resistance. The plurality of these strategies of resistance, rooted in different cultural identities, biographical experiences and political philosophies, reflects the creativity in which new forms of resistance are forged and tested in public contexts of Native/Euro-Canadian interaction.

Tyrimo tikslas – nustatyti nėščių moterų B grupės β hemolizinio streptokoko (BGS) ir Escherichia coli (E.coli) nešiojimo bei naujagimių kolonizacijos dažnumą ir įvertinti šių mikroorganizmų įtaką naujagimių ankstyvai infekcijai atsirasti. Metodika. Perspektyvinis momentinis stebėjimo tyrimas vykdytas Kauno medicinos universiteto Akušerijos ir ginekologijos bei Neonatologijos klinikose. Moterims du atskiri pasėliai iš makšties apatinio trečdalio ir išangės buvo paimti 35-37 nėštumo savaitę arba gimdymo metu, o naujagimiams - iš ausies išorinės landos bei nosiaryklės per 5 – 15 min. po gimimo. Išskirtų BGS serotipavimas atliktas naudojant 9 specifinius antiserumus, o jautrumas antibiotikams nustatytas diskų difuzijos metodu pagal klinikinių laboratorijų standartus nustatančio komiteto (NCCLS) rekomendacijas. Rezultatai. Šimtas keturiasdešimt aštuonioms moterims iš 970 (15,3 proc.) buvo nustatytas BGS nešiojimas, o 193 moterims (19,9 proc.) - E.coli nešiojimas. Naujagimių BGS ir E.coli kolonizacijos dažnumas buvo 6,4 proc. ir 14,4 proc., o vertikalaus pernešimo – atitinkamai 28,4 ir 24,4 procentai. Moterims ir naujagimiams dažniausiai identifikuotas III ir Ia serotipo BGS. Bendras naujagimių įgimtos infekcijos dažnumas buvo 37,5 atvejai iš 1000 naujagimių, o BGS sukeltos infekcijos dažnumas - 3,6 atvejai iš 1000 naujagimių. Nebuvo nė vieno E.coli sukeltos ankstyvos naujagimių infekcijos atvejo. Klinikinis sepsis diagnozuotas 5 kartus dažniau nei mikrobiologiniais tyrimais... [toliau žr. visą tekstą] / Objective - to examine the prevalence of maternal and neonatal colonization of group B streptococcus (GBS) and Escherichia coli (E.coli) in our area, and to evaluate the colonization impact on early onset neonatal infections as a whole. Methods. A prospective cross-sectional study carried out at the Department of Obstetrics and Gynaecology and the Department of Neonatology of Kaunas University Hospital. Samples were collected from the lower vagina and the anorectum of pregnant women at 35-37 weeks of gestation or at delivery and the ear canal as well as throat of the neonates within 5 – 15 min of their lives. The distribution of serotypes of the GBS identified was determined using specific antisera and antimicrobial susceptibility was investigated by disc-diffusion method as described by National Committee for Clinical Laboratory Standards (NCCLS). Results. GBS carriage was detected in 148 (15.3%) of 970 women screened whereas E.coli colonisation was found in 193 (19.9%) of the women studied. The overall GBS and E.coli neonatal colonization rates were 6.4% and 14.4%; vertical transmission rates - 28.4% and 24.4%, respectively. The most common GBS serotypes were III and Ia. The overall incidence of early onset neonatal infection was estimated to be 37.5 per 1000 live birth and the incidence of early onset GBS disease in newborns – 3.6 per 1000 live birth. There was no case of early neonatal E. coli infection. The incidence of clinical sepsis in neonates was 5 fold higher that... [to full text]

Parasitism in plants is often accompanied by a suite of morphological and physiological changes resulting in a condition known as the ‘parasitic reduction syndrome’. With changes including extreme vegetative reduction, frequently beyond any resemblance to its photosynthetic relatives, accompanied by significant losses of genes linked to photosynthesis, the study of parasitic plants can be challenging. Conopholis (Orobanchaceae) is a small holoparasitic genus distributed across eastern and southwestern North America and Central America. This genus has never been the subject of a molecular phylogenetic or morphometric analyses. In addition, very little is known of the relationships among populations and of their post-glacial history. To investigate the species limits and phylogenetic relationships in Conopholis, we conducted a comprehensive molecular phylogenetic study of the genus as well as a fine-scale morphometric study. Based on plastid and nuclear sequences, Conopholis was found to contain three distinct and well-supported lineages which have varying degrees of overlap with previously proposed taxa. The clustering and ordination analyses of the morphometric study corroborated the molecular data, demonstrating the morphological differentiation between the three lineages detected within Conopholis. A taxonomic re-alignment is proposed for the genus that recognizes three species, C. americana, C. panamensis, and C. alpina. To address genetic diversity and phylogeographic structure of C. americana in eastern North America, microsatellite markers were developed and characterized for the first time in this species. Using these newly generated markers along with sequences from the plastid genome, the persistence of a minimum of two glacial refugia at the last glacial maximum were inferred, one in Florida and southern Alabama and another in the Appalachian Mountains near the southern tip of Blue Ridge Mountains. The diversity seen across the southern Appalachian Mountains supports the hypothesis that populations derived from the southern and northern refugia come together in this area.

No abstract available. / Thesis (Ph.D.)-University of KwaZulu-Natal, Durban, 2008.