An experimental study of the partitioning of aluminum between olivine and spine] was carried out at 100 kPa over the temperature range 1250-1450°C at an oxygen fugacity 1.8 log units below the quartz-fayalite-magnetite buffer in basaltic starting compositions. The partitioning is temperature sensitive and experimental data can be fitted to the relation: T.al (K) = -10500/ {ln([Al2O3]ol/[Al2O3]SP) - 0.98 *(Cr#-sp-0.5) -- 0.75J where [Al2O3]° and [Al2O3] se are concentrations of Al2O3 in olivine and spinel (wt%), and Cr#-sp is Crl(Cr+A1+Fe3+) in spinel. This thermometer is calibrated for olivine with MgI(Mg+Fe) between 0.87 and 0.93, and spine] with Crl(Cr+Al+Fe3+) between 0.07 and 0.63 and Fe 3+/(Cr+Al+Fe3+) between 0.02 and 0.05. and it reproduces experimental conditions to ±20°C. This thermometer generally yields temperatures lower than the two pyroxene thermometer when applied to natural mantle peridotites. The difference may be caused by inaccuracy in both thermometers or by faster Al diffusion in olivine than Ca diffusion in the pyroxenes. Preliminary investigations of the potential of Cr and Si exchange between olivine and spinel as further geothermobarometers are also presented.

A greenhouse experiment was carried out to screen for potential effects of transgenic aspen over-expressing a hybrid poplar leaf polyphenol oxidase gene on rhizosphere communities. Heterotrophic plate counts and cultivation-independent methods were used to compare bacterial and fungal populations associated with transgenic PPO over-expressing and unmodified control trees. Total community DNA extracted from rhizosphere soils was used to establish Iibraries containing partial gene sequences that were PCR-amplified from community members, and putative taxonomy was assigned to clones based on similarity to reference sequences. Gene libraries for the bacterial component of the rhizosphere were established using partial 16S rRNA and chaperonin-60 gene sequences, and the fungal community was characterized based on partial 18S rRNA gene sequences. Phylogenetic analysis revealed that bacterial 16S gene libraries were dominated by Alphaproteobacterial sequences, and the CPN-60 gene libraries were dominated by members of the Bacteroidetes/Chlorobi group, illustrating the biases potentially incurred by using a single gene locus to profile microbial diversity. In both CPN-60 and 16S rRNA libraries, only minor components of the bacterial community differed between transgenic and unmodified trees. Comparisons based on library coverage indicated that changes in bacterial community structure between transgenic and unmodified trees were minor in comparison to differences observed between individual trees of the same type, and no significant differences in terms of bacterial species diversity were revealed by the calculated diversity, dominance and evenness indices. In comparison to the bacterial gene libraries, higher coverage of the underlying population was achieved in the fungal 18S libraries. Members of the Zygomycota, Chytridiomycota, Ascomycota, and Basidiomycota were recovered from both libraries. Dominant groups of fungi associated with each tree type were highly similar, although there were some qualitative differences in the recovery of less abundant fungi as a result of the underlying heterogeneity of the fungal population. No clear differences in terms of fungal species richness were associated with transgenic or unmodified trees, although control libraries were characterized by a slightly higher level of dominance. In general, the methods employed revealed only minor differences between the bacterial and fungal communities associated with transgenic and unmodified trees, suggesting that impacts of the transgenic plants on the rhizosphere community were minimal.

Female wrestlers live in paradoxical worlds on and off the mat. Wrestling is a traditionally masculine activity, demanding specific gender performances, while the social world has different gendered expectations for women. Using grounded theory analysis of qualitative interviews with ten Canadian female wrestlers. this research explores and examines wrestlers' experiences across contexts in order to understand the potential effects of wrestling on wrestlers' gender performances and the social definition of femininity. On the mat, wrestlers' performances incorporate masculine qualities, including assertiveness, competitiveness, confidence, and independence. Off the mat, wrestlers display normatively feminine qualities, including attentiveness to appearance, displays of heterosexuality, sociability, and emotionality. They also retain several of their on-the-mat masculine characteristics, resulting in less traditionally feminine displays in contrast to the hegemonic norm. Wrestlers' performances may affect the social definition of femininity by displaying an alternative performance of femininity, and by expanding the limitations of what is considered feminine.

Structures within general relativity are examined. The differences between man-made structures and those predicted by the Einstein differential equations are very subtle. Exotic structures such as the Godel Universe and the Gott cosmic string are examined with emphasis on closed time-like curves. Newtonian models are seen to also have an exotic aspect in that a vast halo consisting of unknown matter dominates the galaxy. We introduce a model for galaxies based on a general relativity framework with the goal of excluding such artifacts from the system while describing the flat-rotation curves. Structures within this model were speculated to be exotic but after close scrutiny, their nature is shown to be benign. Numerical approaches are applied to model four galaxies: The Milky Way, NGC 3031, NGC 3198 and NGC 7331. Density and mass are deduced from these models and compared to the Newtonian models. Within the visible/HI region, there is 30% reduction in total mass. Extending the model to 10 times beyond the HI region using various fall-off scenerios, it is shown that there is only modest increase of the accumulated mass. In comparison to the Newtonian approach to galactic dynamics, the massive halos are not required to account for the flat velocity profiles.

Neural crest cells go through an epithelial-mesenchymal transition (EMT) before they migrate. B1 integrins are necessary during these phases of neural crest development, but it is unclear if integrins are required for both EMT and neural crest migration. Chimeric integrin B1 subunit and mutant Rho GTPases are used in this study to assess function during neural crest emigration. Cultures of chick embryonic cells, transfected with these constructs, are used to confirm the effects and expression in conjunction with a green fluorescent protein (GFP) reporter. In control experiments targeting the neural ectoderm of the hindbrain by localized electroporation. GFP-expressing cells release from the neural tube, migrate along neural crest pathways and express the HNK-1 neural crest marker. Immunolabeling of Sox9 and Slug neural crest markers shortly after electroporation confirms transfection of prospective neural crest cells. Electroporation with a chimeric hemagglutinin-B1 integrin subunit inhibits release of transfected cells from the neural tube. Embryos electroporated with constitutively active RhoA have a few transfected cells outside the neural tube that express N-cadherin. but they fail to migrate to the branchial arch. Electroporation with constitutively active Rac1 results in numerous cells near the neural tube, none of which express N-cadherin. Embryos electroporated with Cdc42 mutants are not distinguishable from control embryos expressing GFP alone. In embryos co-electroporated with chimeric integrin and dominant negative RhoA together, co-transfected cells migrate along neural crest pathways. The conclusion is that integrin signaling, transduced through RhoA, is necessary for the EMT of cranial neural crest. Key to this investigation of neural crest emigration is the methodology of localized electroporation. This technique introduces transgenes to targeted patches of cells in the embryo. Localized electroporation employs a double-barreled suction electrode to deliver plasmid and produce an electric field. Parameters for localized electroporation are optimized for transfecting a range of cells in the chick embryo, and expansion of the technique to mammals is demonstrated. Localized electroporation has improved reliability and higher efficiency than existing in vivo transfection techniques.

Gaucher Disease (GD) is characterized by the accumulation of glucocerebroside, leading to enlargement of the liver and spleen and lesions in bones. It is caused by an inherited deficiency of the enzyme glucocerebrosidase (GBA). GD results in chronic pain, fatigue, jaundice. bone damage, anemia, hepatosplenomegaly, and even death. Currently. there is no cure for this disease, but enzyme replacement therapy (ERT) has become available. For this treatment, GBA is produced by recombinant DNA technology and then administered to the patients. However, producing recombinant GBA from mammalian cell lines is laborious, costly, and has poor yield, making the expression and purification of GBA from an alternate source desirable. We have expressed recombinant GBA in transgenic Pichia pastoris, in which the yeast mannosidase gene responsible for hyperglycosylation has been deleted and replaced by its human counterpart for proper post-translational modification. This humanized yeast was used to study the expression, processing, and purification of GBA. Specifically, GBA was expressed as a fusion protein containing a hexahistidine tag and a Factor Xa cleavage site to aid in the detection of GBA during expression and purification. Secreted GBA appeared from 24 to 72 hours post-induction, and constituted the major protein species in the culture medium. GBA was purified to apparent homogeneity in a successive two-step method using hydrophobic interaction chromatography and nickel-chelating affinity chromatography. Functional analysis of GBA using the fluorogenic substrate 4-methyl-umbelliferyl glucopyranoside assay demonstrated biochemical activity with the artificial substrate. Moreover, recombinant GBA was successfully detected by immunoblotting using a glucopyranoside assay demonstrated biochemical activity with the artificial substrate. Moreover, recombinant GBA was successfully detected by immunoblotting using a monospecific antibody directed against homogenous human native GBA. Both results suggest that GBA produced in humanized P. pastoris may be an appropriate therapeutic agent for ERT of GD patients. It will permit large scale expression of human recombinant GBA using fermentation technology for effective and affordable treatment of all 3 clinical forms of GD. Furthermore. it can also serve as a model for treatment of other neurodegenerative metabolic diseases that collectively inflict much human suffering.

With the average female life expectancy in Canada currently at 82 years, women are now spending approximately one-third of their lives in a hypoestrogenic state. Numerous studies from the basic sciences have shown that estrogen is neuroprotective in a variety of ways. The findings from the clinical studies of the effects of estrogen replacement on cognition in postmenopausal women are more inconsistent, though current research suggests that the timing of initiation of estrogen replacement relative to menopause is a major contributing factor to the discrepant findings in this literature. Reproductive and biological variables that affect levels of endogenous estrogen throughout a woman's lifespan may also influence cognitive function later in life as well as modify a woman's response to exogenous estrogen. The present study looked at the effects of cumulative estrogen exposure on the performance of a measure of prospective memory in a group of older postmenopausal women. Cumulative estrogen exposure was estimated using a mathematical index that included variables known to influence estrogen levels across the life span such as age at menarche and menopause, parity, duration of breastfeeding and estrogen replacement therapy, body mass index and time since menopause. Prospective memory is memory for future intentions and it was chosen because of its relevance for independent function and possible utility as an early indicator of dementia. Imaging studies link prospective memory to the prefrontal cortex, an area of the brain that is known to be influenced by estrogen so it was hypothesized that women with higher levels of cumulative estrogen exposure would perform better on a measure of prospective memory than women with lower levels of endogenous estrogen. Measures of verbal memory were also included in the study for comparative purposes as verbal memory is the cognitive function reported most consistently in the previous literature to be affected by postmenopausal estrogen replacement use. The results of the multivariate analyses indicated a significant positive correlation between prospective memory scores and cumulative estrogen exposure but only when women who had initiated estrogen replacement more than five years after menopause were excluded from the analysis. The significant positive correlation between cumulative estrogen exposure and prospective memory performance remained significant when only women who had never used estrogen were included in the analysis. No relationships were observed between levels of cumulative estrogen exposure and performance on measures of verbal memory. While the study was limited by the fact that it was observational in nature and the sample size was small, the results are consistent with recent findings from the hormone literature, in that they suggest that the timing of hormone replacement as well as the influence of variables that affect endogenous estrogen levels over a woman's lifespan need to be considered when studying relationships between cognitive performance and estrogen. In addition, the finding that performance on a measure of prospective memory but not performance on a measure of verbal memory was associated with levels of cumulative estrogen exposure adds further support to the theory that the frontal cortex may be especially sensitive to estrogen.

This paper examines the "cultural thesis," a normative account of why culturally diverse polities should recognize and accommodate minority and indigenous claims for cultural protection, and addresses the "anti-essentialist" critique of the cultural thesis. The anti-essentialist critique holds that key arguments for the cultural thesis, such as those advanced by Charles Taylor and Will Kymlicka, support problematic, essentialist concepts of culture. This paper argues that the anti-essentialist critique overlooks key parts of the cultural thesis but does, nevertheless, illuminate the need for an approach to practical claims to culture. Two approaches are presented-the "unbounded approach" and the "shifting boundaries approach"-both of which are developed in contemporary political theory writings. The paper argues that the shifting boundaries approach, which asks us to consider the role that a claimed cultural practice or activity plays in enhancing community integrity, provides a better framework for understanding the claims advanced by minorities and indigenous peoples. Both the drawbacks of the unbounded approach and the advantages of the shifting boundaries approach are discussed in relation to the Aboriginal rights case R v. Van der Peet.

Theory of mind development and gender-typed development are two areas of children's social-cognitive development that have rarely been compared. The current study predicted that a relation between theory of mind and gender-typing would exist based on components from both areas of development sharing similar social-cognitive processing demands. Eight tasks examined 5- to 7-year-olds' understanding of social perspective taking. interpretive theory of mind, gender constancy. gender stereotypes_ gender flexibility. and vocabulary. As predicted. children's knowledge of social perspective taking was related to gender constancy understanding over and above age. gender. and vocabulary. No relation was found between children's knowledge of social perspective taking and gender stereotype rigidity or between children's knowledge of interpretive theory of mind and gender flexibility. Implications for the findings and suggestions for future research are presented.

INTRODUCTION: Anxiety has been thoroughly reported in response to the treatment of breast cancer, however, the research examining the effects of acute exercise among breast cancer survivors is limited. Only one study, primarily exploratory in design, has examined the anxiolytic effects of acute exercise with breast cancer survivors. PURPOSE: 1) Determine whether acute exercise reduces state anxiety in breast cancer survivors and those without a cancer diagnosis in a similar fashion. 2) Investigate the difference between exercise intensity conditions for pre-post and post-after state anxiety changes. 3) Examine whether changes in self-efficacy are reciprocal with the changes in state anxiety. and 4) Explore selected moderator variables of the exercise-state anxiety relationship. METHODS: Twenty-five breast cancer survivors and twenty-five age-matched women without a cancer diagnosis cycled for 20 minutes at light and moderate intensities on two separate occasions. State anxiety and self-efficacy measures were completed before, immediately following and 10 minutes post exercise. RESULTS: 2 x 3 RM ANOVA revealed a main effect for time for both light and moderate conditions (F(2.46) = 10.09. p < .01. n2 = .18 and F(2.47) = 22.34. p < .01. r 2 = .32 respectively) but between group interaction effects were not significant. For self-efficacy. 2 x 3 RM ANOVA found main effects for both light and moderate conditions (light exercise F(2. 41) = 9.82. p < .01. n2 = .19; moderate exercise F (2.44, = 4.86. p < .01. n2 = .10) with no between group interaction effects. Correlations between anxiety and self-efficacy change scores showed moderate associations for light condition post-after exercise (r = .50. p < .040) and moderate condition pre-post exercise (r = .29. p < .05). In a secondary analysis. groups median split on high/low trait anxiety showed significant differences between groups (light exercise F( 1.43) = 5.05, p < .05. n2 = .11: moderate exercise F(1.44) = 6.16. p< .05. n2 = .12) as did results median split by pre-exercise state anxiety levels (light exercise F,1.45) = 33.21. p < .01, n2 =.45: moderate exercise F(1.46) = 58.93, p < .01. q2 =.56). CONCLUSION: Exercise decreases state anxiety for breast cancer survivors and the general population alike. However. this relationship appears to be moderated by trait anxiety and pre-exercise anxiety. Self-efficacy is important for dose-response and theory-based exercise prescriptions, but future research should focus on subpopulations known to posses high levels of anxiety and poor exercise self-efficacy.