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Investigating the germination of two native New Brunswick species (Halenia deflexa and Lysimachia terrestris)
No full textNative Plants have been historically understudied but are essential to both local ecosystems and restoration efforts. Two New Brunswick Native plants (Halenia deflexa and Lysimachia terrestris) were investigated to better understand the requirements to grow seedlings for future studies. To accomplish this, we needed to determine any seed dormancy mechanisms at play, and the seed quality of each species. Imbibition trials, and germination studies on two media were used to investigate dormancy types, while cut tests and TTC staining were used to investigate seed quality. Both species imbibe water, prefer agar as a soil medium, require only 9 weeks in cold stratification, and germinate more often when Gibberellic Acid is present. Halenia deflexa should also receive an additional growth supplement, such as MS salts, to aid in seedling establishment. New Brunswick populations of both species had comparatively normal seed quality for this area, but an Albertan seed population of H. deflexa had significantly poorer seed quality. If attempting to propagate L. terrestris from vegetative propagules instead of seeds, bulbils should not be stored on top of moist vermiculite at room temperature
The photosynthetic strategies of the wild Prochlorococcus marinus
Get PDFProchlorococcus marinus, the most abundant photosynthetic organism on the planet, can be found stratified throughout the marine water column from the surface waters to the bottom of the euphotic zone. Strains of Prochlorococcus at different depths exhibit diverse responses to light, however, they are notoriously difficult to culture and consequently few of these strains have been studied in vitro. As the past research that has been conducted on Prochlorococcus demonstrates novel and diverse photosynthetic strategies, we have analyzed mass spectrally detected Prochlorococcus peptides, obtained from North Pacific Ocean water samples, to investigate the photosynthetic strategies of wild Prochlorococcus in their natural habitat. We focussed on the major photosynthetic structures: the light harvesting Prochlorophyte Chlorophyll Binding proteins, photosystem II, cytochrome b6f, and photosystem I as well as the rate-limiting enzyme in the Calvin cycle, Rubisco, the NADPH Dehydrogenase complex, plastiquinol terminal oxidase, the ATP synthase complex and the FtsH proteases purportedly involved in photosystem repair. We found that Prochlorococcus in the North Pacific Ocean do not photosynthesize below 200 m and may become heterotrophic under low oxygen and light conditions, suggesting potential for mixotrophy under other conditions. It was further found that some Prochlorococcus in the North Pacific Ocean are deficient in Cytochrome b6f and may therefore be using novel alternative electron transport strategies. We found a strong correlation between Rubisco expression and oxygen, suggesting increased capacity to fix carbon
and perform linear electron transport in high oxygen conditions. We further found that lowlight preferring strains have little capacity to repair their photosystems due to deficiency in FtsH proteases. The overall results of the present research show that Prochlorococcus uses ecotype, clade and strain-specific photosynthetic strategies that are associated with not only depth (and consequently light) but oxygen concentrations as well. Therefore, it is proposed that a dichotomous classification considering both depth/light and oxygen preferences of each strain would better reflect the diversity of photosynthetic capacities of individual strains. The results of this research give insight into future directions for the continued study of Prochlorococcus
Niche partitioning and behaviour of migratory shorebirds in the Northumberland Strait and Bay of Fundy
Get PDFAnimal populations take advantage of environmental heterogeneity to partition themselves into microhabitat niches. Such partitioning plays an important role in determining interspecific competition and community structure by allowing multiple species to coexist. Many species of shorebirds use stopover sites in Atlantic Canada to fuel their annual southbound migration in late summer and early fall. The Bay of Fundy is recognized as a landscape of hemispheric importance for migratory shorebirds, and hosts hundreds of thousands of Semipalmated Sandpipers annually. Other stopover sites on the eastern coast of New Brunswick, Canada, host smaller but more diverse shorebird populations. There is a lack of research on stopover ecology of whole shorebird communities in New Brunswick, especially at small coastal stopover sites. We examined stopover ecology at staging areas in the Bay of Fundy and Northumberland Strait to examine niche dynamics relative to shorebird behaviour and habitat use. Foraging strategies and rates varied among shorebird species at stopover sites on the Northumberland Strait and also between Semipalmated Sandpipers in the Bay of Fundy and Northumberland Strait. We found that Short-billed Dowitchers primarily forage by probing, and Semipalmated Plovers forage by pecking. Semipalmated Sandpipers, White-rumped Sandpipers, Least Sandpipers, and Yellowlegs used a combination of pecking and probing. Diets also varied between species and sites. We found that Semipalmated Sandpipers and Semipalmated Plovers consume generalist diets, while the diets of Short-billed Dowitchers and White-rumped Sandpipers were more specialized for specific food sources. Different taxa face foraging constraints based on morphological features, which creates both spatial and behavioural segregation. This was evident on the Northumberland Strait, probably because greater environmental heterogeneity in small coastal sites created more dimensions for segregation than large mudflat sites. As a result, a wider diversity of species can co-exist. Small coastal sites constitute important stopover habitat for migratory shorebirds outside of the Bay of Fundy. These findings broaden our understanding of stopover ecology of multi-species flocks and indicate that conservation of small coastal sites is also important for success of migratory shorebirds in Atlantic Canada
Synthesis of cis-dichloro-(pyridine-2-carboxaldimine)platinum(II) compounds for potential anticancer application
Get PDFIn an effort to develop effective long-term and short-term cancer treatment methods, research over the last fifty years has focused itself in a variety of areas including radiation and chemotherapy treatments. One of the first anticancer drugs discovered, cisplatin (cis-PtCl2(NH3)2) has had promising results in reducing the proliferation of cancer cells. Millions of patients diagnosed with a range of different cancers have benefited from the use of cisplatin. Even with the benefits, there are a number of major problems involving this drug that have limited its clinical applications, such as acquired drug resistance and cytotoxicity. Consequently, in the last thirty years, analogues of cisplatin complexes have been an important area of research in order to combat these issues. Even though the design is similar, more effective anticancer drugs have been in question. In this study, two novel platinum analogues of cisplatin were prepared. Compound 2a was fabricated by beginning with the synthesis of the bulky and lipophilic ligands which was then added to [PtCl2(cis-cyclooctene)]2 to create the desired platinum compound. Compound 2b, using the same procedure, was successfully synthesized, but with alterations on the ligand (1b). All compounds produced moderate yields and were characterised using 1H NMR, 13C{1H} NMR and FTIR spectroscopy. Detailed analysis of these spectrums concluded that these compounds were successfully synthesized. For this reason, further application of these compounds is promising and with biological testing there may be hope for new and more efficient novel anticancer compounds
An analysis of elk (Cervus canadensis) railway usage following highway wildlife collision mitigation near Burwash, Ontario
Get PDFoai:mta.scholaris.ca:20.500.14662/668In recent years, the province of Ontario has implemented highway wildlife collision mitigation infrastructure, such as fencing, over- and under-passes along the Trans-Canada Highway south of Sudbury. However, as is often the case, the nearby railway did not receive any such infrastructure. Since elk have been known to use railways for movement, and consistent use of railways inevitably results in wildlife mortality, research needed to be done to determine the changes in use of the railway following the implementation of wildlife collision mitigation infrastructure. The central question essentially being, now that one travel corridor had been closed to the elk, what changes will occur in the other? Here, the proportional usage of the railway prior to and following this infrastructure project are investigated, mapped, and discussed. It was found that the elk near Burwash spent a significantly greater proportion of time near and on the railway following mitigation in comparison to before mitigation. Major shifts in distribution of the elk population are shown and discussed. In all, this work shows that while wildlife collision mitigation is undoubtedly a benefit to wildlife and humans in the context of the highway, these changes may alter the behaviour of elk in unforeseen ways
Lights and shadows in promoting cross-cultural education for Central American refugees and immigrants in Toronto
Get PDFThis research examines educational experiences of Central American immigrants and refugees in Toronto by analyzing interview narratives from six service providers who work at community organizations. These narratives are divided into five categories: language barriers, stereotypes, a sense of belonging, cultural education, and self-advocacy. The study contributes to our understanding of the implications of the absence of minority culture in education. Education is critical for the Central American population to increase opportunities for employment in Canada, and to facilitate access to other institutions and services. The Toronto District School Board’s census portraits help to indicate the role of each stakeholder (parents, students, and teachers) in how they engage with education in Toronto in order to contextualize their cultural uniqueness. Secondly, Critical Pedagogy and Critical Race Theory suggest how Eurocentric curriculum can be challenged and replaced with less culturally biased curriculum through narrative engagement. Lastly, through the interviews, research participants address a lack of representation of the Central American population in education and the danger of marginalization. Overall, this study suggests how inclusive education will meet with only limited success if the learning approach does not encourage minority students’ voices to address the lack of culturally diverse curriculum and raise the impact of student-centred learning
Identifying epigenetic differences between Ixodes scapularis (black-legged tick) infected and uninfected with Borellia burgdorferi
Get PDFBorrelia burgdorferi, the causative agent of Lyme disease, has long been recognized to modulate physiological and behavioural changes in the host for the disease, Ixodes scapularis. However, the mechanism by which this bacterium modulates these changes remains unknown. There are 3 distinct epigenetic mechanisms, histone modification, non-coding RNA regulation and DNA methylation, each of which alter gene expression through chromatin modification rather than changes in the genetic code itself. Epigenetics in the I. scapularis is relatively understudied, with little to no current research on DNA methylation specifically. Presently, it is unknown if DNA methylation changes or remains the same in the presence of B. burgdorferi. Furthermore, epigenetics has yet to be explored as the possible cause for the physiological changes in Ixodes scapularis, in response to infection by B. burgdorferi. In this study, the DNA methylation status of the pericentromeric tandem repeats family, Ixodes scapularis Repeats (ISR), in Borrelia-infected and non-infected I. scapularis samples was investigated. This was done through performing methylated-DNA immunoprecipitation reactions on I. scapularis DNA extracts of either infection status. DNA methylation status was quantified through a qPCR analysis involving the immunoprecipitated DNA, and primers targeting each ISR region. Calculations found that when comparing the ISR2A, ISR2D and ISR3 regions, overall significantly more DNA methylation was measured in the Borrelia-infected samples (p = 0.0129,
n=3). The same trend was observed when targeting the ISR2B and ISR2C regions (n=1). Additionally, the ISR regions were found to be differentially methylated, with the ISR2A (p = 0005838, n=3) and the ISR3 (p = 0000833, n=3) regions experiencing significantly more DNA methylation than the ISR2D region. The ISRC region was also found to be more heavily methylated than the ISR2B region (n=1). This study found novel evidence that DNA methylation in I. scapularis may be responsive and modulated by the presence of B. burgdorferi. Additionally, it was demonstrated that distinct genomic regions can differ in their epigenetic responsiveness, and that the ISR2A, ISR2C and ISR3 may act as epigenetic markers in this organism. These results provide the groundwork for future epigenetic studies of the I. scapularis in relation to B. burgdorferi
Survival strategies of the mediophycean diatom ditylum brightwellii (T west) grunow
Get PDFThis project is aimed at building on the less known life history strategies in Ditylum brightwellii, by focusing examination on the production and morphology of various cell types. Vegetative cell enlargement was induced by allowing cultures of cells to deplete their medium of nutrients and subsequently introducing nutrient replete medium. Enlargement was examined by light microscope, epifluorescence microscope with DAPI and PDMPO (2-(4-pyridyl)-5-((4-(2dimethylaminoethylaminocarbamoyl)methoxy)phenyl)oxalole) stain. Attempts at observation enlarged cells under the scanning electron microscope were unsuccessful due to fragility of enlarged valves. Vegetative cell enlargement was confirmed to occur as cells enlarged and their non-enlarged valves remained on the cell. D. brightwellii was observed to vegetatively enlarge their cells through two methods: one-step enlargement, and multi-step enlargement. During one-step enlargement, a single D. brightwellii cell will enlarge without producing supernumerary valves. Multi-step enlargement is the opposite, where D. brightwellii cells produce progressively larger supernumerary valves. Resting cells were observed to occur in all samples and were not induced through any experimental methods. Resting cells were observed to exit the valves (naked cells) and produce pseudopod-like structures. The pseudopod structures were observed to move freely on a microscope slide and could extent or retract. Resting spores were induced by inoculating D. brightwellii into a nitrogen depleted medium, also known as T medium. Resting spores were induced after 2 weeks of being inoculated in the nitrogen depleted medium. D. brightwellii cells plasmolysed in the T medium and remained plasmolysed until they became resting spores. The plasmolysed cells lost the colour within their chloroplasts and retracted to a portion of the cell
Linear inequalities related to quantum entanglement theory
Get PDFIn this thesis, we will consider various linear inequalities relating the entries and eigenvalues of certain types of matrices. Our approach will consist of constructing inequalities which set bounds on the eigenvalues of entanglement witnesses, a type of matrix of interest to quantum information theory. We will then consider what these can tell us about the relation between the off-diagonal entries and eigenvalues of positive semidefinite matrices