Habitat selection of three rodents in a frequently burned boreal environment : productivity and habitat diversity

How does fire affect the plant and animal community of the boreal forest? This study attempted to examine the changes in plant composition and productivity, and small mammal demography brought about by fire in the northern boreal environment at Chick Lake, N.W.T. (65053fN, 128°14,W). Two 5*6 ha plots measuring 375m x 150m were selected for study during the summers of 1973 and 197^. One had been unburned for 120 years, the other was part of a fire which burned in the spring of 1969. Grids of 15m x 15m were established in each plot and meter square quadrats taken at each of the 250 grid intersections in order to determine plant composition and density. Aerial primary production was assessed by clipping and drying 80 samples of terminal new production for each species under investigation. Small mammal populations were sampled by placing a Sherman live trap at each grid intersection for ten days in every month. The two plots were similar in plant species composition which suggested that most regrowth in the burned area was from rootstocks which survived the fire. The plant data were submitted to a cluster analysis that revealed nine separate species associations, six of which occured in the burned area and eight of which occured in the control. These were subsequently treated as habitats for purposes of comparison with small mammal distributions. The burned area showed a greater productivity in flowers and fruits although total productivity in the control area was higher due to a large contribution from the non-vascular component. Maximum aerial productivity as dry wieght was measured at 157.1 g/m and 207.8 g/m for the burn and control respectively. Microtus pennsylvanicus and Clethrionomys rutilus were the two most common small mammals encountered; Microtus xanthognathus, Synaptomys borealis, and Phenacomys intermedius also occured in the area. Populations of M. pennsylvanicus and C. rutilus were high during the summer of 1973; however, M. pennsylvanicus was rare on the control but abundant on the burn, while C. rutilus was rare on the burn but abundant in the control. During the summer of 197^ populations declined, with the result that few voles of any species were caught in the burn while equal numbers of the two species were caught in the control. During the summer of 1973 M. pennsylvanicus showed a positive association to the most productive habitat type in the burn which was avoided by C. rutilus. In the control £• rutilus showed a similar positive association to the most productive habitat type which was avoided by M. pennsylvanicus. In all cases for the high population year of 1973# the two species never overlapped in habitat preference. When populations declined in 197^f "both species showed a strong association for the most productive habitat in the control. This would suggest that during a high population year, an abundant species can exclude competitors from a chosen habitat, but that this dominance decreases as population levels decrease. It is possible that M. pennsylvanicus is a more efficient competitor in a recently burned environment, while C. rutilus assumes this role once non-vascular regrowth becomes extensive.

Microstructural and geochemical investigation of North American lower-middle Paleozoic trilobites and recent arthropods

Trilobites ¥tere collected from Ordovician and Devonian formations of Ontario} New York} Ohio} Oklahoma} and Indiana. Diversity was generally low} but 19..?telllS and Ph..~tY>ps ¥tere the most abundant species from the Ordovician and Devonian} respectively. Recent marine arthropods ¥tere collected from the Atlantic shore of the middle Florida Keys} and from the Pacific and lagoonal waters at Cape Beale} B. C. Fresh-water arthropods were collected along the shore of the Severn River in northcentral Ontario. Cuticles ¥tere analyzed for major} minor and trace elements, 180 and 13C isotopes, as ¥tell as examined by scanning electron micr?scope to identify original and diagenetic fabrics. Examination of trilobite cuticles by scanning electron microscope revealed several microstructures consistent with those observed in Recent arthropods. Microstructures} such as setae and tegumental gland duct openings} in like sized Lim/IllS and Isoteline trilobites may indicate common ancestral origins for these organisms, or simply parallel cuticle evolutions. The dendritic microstructure, originally' thought to be a diagenetic indicator, was found in Recent specimens and therefore its presence in trilobites may be suggestive of the delicate nature of diagenesis in trilobites. The absence of other primary microstructures in trilobites may indicate alteration, taxonomic control} or that there is some inherent feature of S EM examination which may' not allow detection of some features} while others are apparently visit·le onl~1 under SH.·1. The region of the cuticle sampled for examination is also a major influence in detecting pristine microstructures, as not all areas of trilobite and Recent arthropod cuticles will have microstructures identifiable in a SEM study. Subtleties in the process of alteration, however} ma~·· leave pristine microstructures in cuticles that are partial~/ silicified or do 10m itized, and degree and type of alteration may vary stratigraphically and longitudinally within a unit. The presence of fused matrices, angular calcite rhombs, and pyrite in the cuticle are thought to be indicative of altered cuticles, although pyritization may not affect the entire cuticle. t-~atural processes in Recent arthropods, such as molting, lead to variations in cuticle chemistries, and are thought to reflect the area of concentration of the elements during calcification. The level of sodium in Recent arthropods was found to be higher than that in trilobites, but highly mobile when sUbjected to the actions of VY'€'athering. Less saline water produced lovy'€'r magnesium and higher calcium values in Recent specimens .. and metal variations in pristine Ordovician trilobite cuticle appears to follow the constraints outlined for Recent arthropods, of regulation due to the chemislry of the surrounding medium. In diagenetic analysis, sodium, strontium and magnesium proved most beneficial in separating altered from least altered trilobites. Using this criterion, specimens from shale show the least amount of geochemical alteration, and have an original mineralogy of 1.7 - 2.4 mole % MgC03 (8000 t(> 9500 ppm magnesium) for both /s>..?/e/11S lJA'i.riff!11S and PseIAit'11J17ites I..itmirpin..itl/~ and 2.8 - 3.3 mole % MgC03 (5000 to 7000 ppm magnesium) for Ph.i{).?PS This is Slightly lower than the mineralogy of Recent marine arthropods (4.43 - 12.1 mole % MgC03), and slightly higher than that of fresh-water crayfish (0.96 - 1.82 mole % MgC03). Geochemically pristine trilobites were also found to possess primary microstructures. Stable isotope values and trends support the assertion that marine-meteoriclburial fluids were responsible for the alteration observed in a number of the trilobite specimens. The results of this stUdy suggest that fossil material has to be evaluated separately along taxonomic and lithological lines to arrive at sensible diagenetic and e nvironmenta I interpretations.

The development, assessment, and implementation of an evaluation of the EMPOWER Program at shelters for abused women /

The development, assessment, and implementation of a program evaluation instrument was carried out to evaluate the impact and efficacy of the EMPOWER Program. This intervention was created to educate residents at a shelter for abused women with an anticipated outcome of prevention. Participants included the staff and residents at 2 shelters in Southern Ontario. Client pre, post and follow-up measures were obtained and analyzed statistically and using keyword content analysis. A single staff measure was obtained and summarized using keyword content analysis. Qualitative results were suggestive of important change in participants. All women in the post and follow-up measures believed their participation in the EMPOWER Program provided them with the knowledge, skills, and confidence to avoid abusive relationships in the fliture. This transformational impact was repeatedly expressed in both resident and staff feedback. Limitations of this research, as well as suggestions for future study were discussed.

The encounter with the real and post-Soviet trauma : fantasy construction in Russian popular cinema /

This thesis examines the impact of the Soviet Union's collapse on the Russian Symbolic as represented through popular cinema of the post-Soviet period. The disintegration of the USSR in 1991 became one of the most traumatic experiences for many Russian people. The trauma of the collapse of the Soviet Union penetrated the everyday reality of the Russian Symbolic, leaving the traces-symptoms in different cultural fonns like literature, arts, television and cinema. Because popular culture usually reacts very quickly to any social, political and economical shifts in society, it is an excellent barometer for deeper changes in society. Focusing on postSoviet popular cinema, this thesis analyzes the symptoms of cultural and individual trauma occasioned by the momentous changes of the 1990's. This study is grounded in post-analytic theory of Jacques Lacan and its interpretation by Slavoj Zizek, which emphases the traumatic encounter with the Real as a "hard core" of our reality. According to this paradigm, a new chain of signifiers is structured around the traumatic breach in the Symbolic, initiating a process of fantasy construction to deal with consequences of trauma and, thus, to support our Symbolic order. This thesis examines three major fantasy constructions - drinking, traveling to a "happy land" and family reunion and money - in popular films by Alexander Rogozhkin, Yurij Mamin, Georgij Shengelia, Dmitrij Astrakhan, Valerij Todorovskij, Alexej Balabanov, Sergej Bodrov Jr. and Petr Buslov. According to Zizek, enjoyment underlies any fantasy constructions, and that is why after the intrusion of the Real every individual and culture should go through the process of fantasizing about some substitutes which can help to minimize the traumatic effect and which can lead to a partial enjoyment. By analyzing the fantasies about drinking, "happy land", reconstruction of the family bonds and money in Russian popular cinema since 1991, this thesis demonstrates how the traumatic engagement with the Real affected the everyday lives of Russian people, and how individuals tried to fill the gap, the lack, in the post-Soviet Symbolic and "return" the lost feeling of unity and plenitude.

The Relationship between Dementia Family Caregivers' Traditional Values and Beliefs about Caregiving and Well-being

Introduction: Canada’s aging population is diverse and this diversity will continue to grow for the next two decades (Government of Canada, 2002; Katz, 2005; Statistics Canada, 2010). Objective: to examine the relationship between dementia family caregivers’ traditionally-based beliefs about caregiving, their caregiving experience, and their well-being. Method: exploratory secondary data analysis of cross-sectional survey data from 76 community caregivers of persons with dementia in Ontario. Results: traditional values for caregiving was independently associated with coping resources and health status but not depression symptoms. Caregiver self-efficacy and social support both partially mediated the relationship between beliefs about caregiving and caregiver health status. Discussion: Findings from this exploratory study are consistent with stress process models of culture and caregiving. The finding that self-efficacy was associated with traditional values and that it mediated the relationship between traditional values and caregiver well-being is new to the literature.