Browsing Honours Theses by Title
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ItemA retrospective assessment of marine ecological research using optimal α(University of New Brunswick, 2020) Zhao, Chuhan; Houlahan, JeffNull hypothesis significance testing (NHST) is and has been for many decades broadly applied across disciplines, NHST’s shortcomings have been identified and discussed since its introduction. Optimal alpha is a better method for setting statistical thresholds in NHST because it minimizes the overall probability of making errors. However, we don’t know how often using optimal α would result in a different conclusion than NHST. I calculate optimal α for 433 tests from 2009-2018 published marine biology papers and compare conclusions with NHST. I find totally 24 % of conflicting results (small ES: 22 %; medium ES: 22 %; large ES: 29 %). For disagreement, optimal alpha has 97 % significant results at small ES, 54% at medium and 24% at large. Low observed p value tends to have disagreement. These results mean that failing to use optimal alpha may be inflating the probability of making wrong conclusions in marine biology. ItemAn inside look at a professional modern dance company(University of New Brunswick, 2016) MacMillan, Marissa; Burns, Janet Mary ChristineThis thesis explores the experiences and collective activity of participants in the art world of Bodies in Motion, a local modern dance organization from Hartford, Chilton. This qualitative research uses Becker’s (1982) framework for studying social organizations, in conjunction with Unruh’s (1979) theory of social worlds and social types, to understand how participants create and maintain the functioning of their social world. The research followed a symbolic interactionist, theoretical approach, where data was collected through interviews and participant-observation. Through these techniques, eleven participants were asked about their experience with Bodies in Motion and the art sphere within Hartford. The research found that Becker’s framework and Unruh’s social types can help to determine the dynamics of social worlds. ItemChange in occupancy and density of nesting Atlantic puffins and razorbills on Machias Seal Island between 2011 and 2019(University of New Brunswick, 2020) Elisseou, Meredyth; H. MajorAt Machias Seal Island (MSI), populations of nesting Atlantic Puffins (Fratercula arctica) and Razorbills (Alca torda) are stable and increasing (respectively). The purpose of my study was to determine whether the increasing Razorbill population has caused a change in the spatial distribution of nesting puffins on the island. I hypothesized that the larger, more competitive Razorbills outcompete puffins for nesting space, resulting in the movement of puffins to alternative regions of the island. Using data from Alcid surveys that occurred in 2011, 2015, 2016, and 2019, I assessed occupancy and density of puffins and Razorbills in each of 1,753 surveyed quadrats. Using generalized linear models in an information theoretic approach, I found no changes in occupancy or density of either species. However, I note the short timespan (eight years) covered in my study and suggest that continued monitoring and analysis of changes in puffin and Razorbill occupancy and density. ItemChanges in body size of Atlantic Puffins at Machias Seal Island (MSI) from 1995-2019(University of New Brunswick, 2020) Georgantopoulos, Joy; Major, HeatherBody size of fledging Atlantic Puffins (Fratercula arctica) at Machias Seal Island have been decreasing over the past 25 years (1995-2019) likely due to climate change. Using fledging size data archived in the Microsoft Access data base “seabird finder” I asked three questions: 1) have puffin fledgers gotten smaller in size (wing chord and mass) over the last 25 years, 2) can small fledgers continue to grow (in wing chord) after leaving the island, and 3) are adult Atlantic Puffins decreasing in size (wing chord). Using linear regressions, I found support for the hypothesis that fledgers are getting smaller with time and that small fledgers grow more after leaving the island than large fledgers. Finally, I found a marginally insignificant result suggesting that adult size is changing in response to fledging size (i.e., adults are becoming smaller with time). ItemComparing the effectiveness of protein coding genes to the ITS gene as DNA barcode markers for species-level identification of Penicillium and Aspergillus fungal isolates(University of New Brunswick, 2020) Po, Hui Ting; Gray, Christopher; Johnson, JohnPenicillium and Aspergillus are important genera of fungi in the order Eurotiales that are species-rich and are found living ubiquitously. The ability to identify these fungal species allows researchers to collate and access valuable information associated with these fungi. In recent years, a molecular technique known as DNA barcoding has become a common method used for fungal identification. The internal transcribed spacer (ITS) gene was described in 2012 as the universal DNA barcode marker for fungal identifications but has limited sequence variability to identify species of Penicillium and Aspergillus. Protein coding genes; benA and calmodulin may be more effective barcode markers for identifying Penicillium and Aspergillus species, respectively, due to higher interspecific variations in the gene sequences. In the present study, we compare whether it is more effective to identify Penicillium and Aspergillus fungal isolates to the species level using protein coding genes or the ITS gene as barcode markers. ItemContribution of variability in embryo development rate and status at hatch to the protracted hatch period of female American lobster Homarus americanus(University of New Brunswick, 2018) White, Lydia; Rochette, Rémy; Zou, LiwenFemale American lobsters typically hatch their embryos over protracted hatch periods of 15-32 days. To investigate the mechanisms underlying this intra-brood variation in hatch time, I reared individual embryos from June to September 2017 at a constant temperature of 9°C, took photos of them at the beginning of the study and prior to hatch, and measured their eye size as a proxy of their development status. A multiple linear regression model explained 74% of the variability in hatch day, and indicated that embryos that hatcher earlier in the summer are (i) more developed come spring (44% of explained variance), (ii) less advanced in development (28%), and (iii) develop at a faster rate (27%). This study suggests that the process of hatching is not strictly associated with a particular role of the brooding female, but rather is perhaps mostly a function of processes or attributes of individual embryos. ItemCultivation of endophytic fungi inhabiting Abies balsamea using two techniques: a comparative study(University of New Brunswick, 2018) Fitzherbert, Tyson; Gray, Christopher; Johnson, JohnTwo cultivation techniques: leaf segment cultivation and dilution-series cultivation, were compared for recovery of endophytes from needles of Abies balsamea collected in Saint John, New Brunswick, Canada. Endophytes were cultured on 2% malt extract agar and morphology of the endophytic growth was used to aid identification of distinct isolates. Endophytes were isolated from A. balsamea needles using the leaf segment cultivation method at a frequency of 13%, all replicates of two distinct isolates. Endophytes were isolated form eight of 25 prepared isolation plates for the dilution-series method. All endophytic growth from the dilution-series method was single-celled yeast species, while the endophytic growth from the leaf segment method was exclusively filamentous fungal species; thus, dichotomy was seen between the two methods of isolation. ItemDetermination of a link between the taxonomic relationship of Canadian medicinal plants and the exhibited antibiotic activity of their crude extracts(University of New Brunswick, 2019) Therrien, Julie K.; Gray, ChristopherChemotaxonomy is effective in determining the expected chemical compounds found in extracts from different organisms. However, this is time-consuming and costly, as it is based on purified fractions of a chemical extract. Utilizing biological activity data of extracts and relating it to the taxonomic relationship of plants may be a more effective approach. The aim of this study was to determine if a link exists between the taxonomic relationship of plants and the exhibited antibiotic activity of their extracts. The antibiotic activity of methanolic extracts of 90 plants were evaluated against eight microorganisms. Bioactivity profiles were created and analyzed, using two separate methods. It was found that the lowest taxonomic level that correlated with the bioactivity profiles of the extracts was family. ItemDoes land-use affect bird abundance?(University of New Brunswick, 2019) Prosser, Jacob; Houlahan, JeffOver the last 50 years many species have seen negative population trends and scientists have identified habitat loss, change, and fragmentation as possible causes. I investigated the ability of random forest and boosted trees models to predict bird abundances based on land-use throughout the United States. Bird abundance data was acquired from the North American Breed Bird Survey (BBS) and land-use data was gathered by the Multi-Resolution Land Characteristics (MRLC) consortium. The models had a mixed transferability between the training and test data with 14 of 21 models better fit the training data. The models were mixed in their ability to accurately predict abundances based on land-use compared to the mean; 14 of 21 models more accuracy predict abundance compared to the mean suggesting an effect of land-use on abundance. Six models were classified as “good,” 11 as “cautious,” and 4 as “poor.” ItemEffects of environmental conditions on egg-laying dates in Atlantic puffin Fratercula arctica(University of New Brunswick, 2019) Fana, Natalia; Major, H.L.; Whidden, S.E.Climate change trends may have an impact on the timing of seasonal activities, and in particular the phenology of Atlantic Puffins. The purpose of this study was to investigate if changes in environmental conditions, such as Sea Surface Temperature (SST), are responsible for the observed delay in egg laying at Machias Seal Island (MSI), New Brunswick. I used monthly means for SST and egg laying dates over a period of 24 years (1995-2018) from MSI. I used general linear models in an AICc framework and found a positive relationship between egg laying dates and SST over time. I suggest continued long-term monitoring to assess future changes and the puffin’s ability to continue to adapt to those changes. ItemGrimm origins: Fairy tale intertexts in Margaret Atwood's short fiction and poetry(University of New Brunswick, 2018) Cormier, Kayla; Maier, Sarah; Creelman, David ItemHuman behavioural ecology in the middle palaeolithic : a comparative study based on how we quantify the use of raw material(University of New Brunswick, 2020) Mears, Peter; Wilson, Lucy; Browne, ConstanceResource Selection Function (RSF) analyses can be used to understand what variables influenced hominin choices for selection of lithic raw materials. Previous work examined stone tool assemblages from the Bau de l’Aubesier (Vaucluse, France), quantifying raw material use by the number of lithics from a particular source area. My study compares this to quantifying use by the weight of those pieces, using Generalized Linear Models that describe the sources of raw material used in each archaeological layer. Independent variables describe raw material characteristics or the surrounding terrain. In the older layers of the site, terrain variables contribute more towards source area use. In the younger layers, raw material characteristics drive source use, but less so in models that quantify lithics by their weight. k-fold cross-validation analyses suggest the best method of quantifying lithic artefacts for use in RSFs may vary depending on the hominin behaviour that led to the assemblage. ItemIdentification and DNA taxonomic analysis of a library of endophytic fungi(University of New Brunswick, 2019) Stack, Ryleigh A.; Gray, Christopher; Johnson, JohnEndophytes represent a largely untapped source of natural products. Despite a growing body of research, data and knowledge relating to endophyte biology and chemistry, one of the difficulties in endophyte research remains the accurate identification of endophytes. The advancements and development of molecular methods have provided researchers with tools that allow them to obtain an identification based on the endophyte’s DNA sequence, rather than its morphological and/or phenotypic characteristics. In the present study, the DNA extracted from 155 endophytes was analyzed following a DNA taxonomy methodology and compiled to give phylogenetic trees to obtain identifications based on the molecular properties of the endophytes, rather than their morphology. Of the 155 endophytes; 57 were identified to the species level, 65 to genus, 5 to class, 2 to subdivision, 10 to order, 15 to family, and 1 to subclass. ItemInfluence of mineralogical composition and texture on induced polarization effects in gold-bearing rocks from the Hebert-Brent Showing, Yellowknife Greenstone Belt, Northwest Territories(University of New Brunswick, 2017) Richardson, Mark; Butler, Karl; Lentz, DavidIn June 2015, geological mapping discovered significant concentrations of gold in the Hebert-Brent (HB) Showing situated within an 11 m-wide highly sulphidized sericite-ankerite schist shear zone, hosted in a 10-15 m-wide, quartz-feldspar porphyry. The HB gold showing is located within the Barney Deformation Corridor of the Yellowknife Greenstone Belt (YGB), Northwest Territories. On July 29th, 2016, two 400 m long IP/resistivity surveys, with 5/10 m electrode spacing were acquired using a multi-gradient array. The survey identified zones of high IP response (chargeability) where expected, in areas of known disseminated sulphide mineralization. In addition, the IP survey exposed a previously undiscovered anomalous IP source. In this study, a prototype two electrode laboratory apparatus was used to investigate factors influencing electrical resistivity and IP effects in selected mineralized and non-mineralized rocks from the survey area. The study revealed information that may be utilized in future geophysical exploration in this area. It was determined that samples from Hebert-Brent are generally less resistive than non-mineralized rocks within this area. However, as a consequence of preferential alignment of silicate layers with foliation, anisotropic effects should be anticipated in this area. The IP response of the mineralized samples was in general greater in magnitude than the non-mineralized samples. It was also determined that there are some IP effects related to highly resistive, non-mineralized rocks in this area. These anomalous IP effects are likely a result of some uncertainty in the measurement apparatus. Normalizing the PFE IP effect by resistivity served to make the mineralized samples standout from highly resistive ones that also exhibited elevated IP responses. Comparison of mineralized and non-mineralized spectral curves were shown to be characteristically different. In addition, the peak phase angle between 0.1 - 10 Hz was found to correlate with increased percent frequency effect. It is recommended that surveys which sense the conductivity of an ore body should be used to aid in delineating massive and electrically conductive parts of a sulphide body. In addition, it is recommended that future IP and resistivity surveys in the area use a measurement of IP effect normalized by resistivity (such as the Metal Factor; MF) to highlight anomalous bodies that are prospective for elevated sulphide (and associated gold) content. Based on the findings in this study, spectral induced polarization (SIP) surveying may aid in identifying mineralized rocks in HB, as the phase maximum (between 0.1 and 10 Hz) is in general greater than that of the non-mineralized country rocks. Testing of the two electrode apparatus was shown to provide accurate and repeatable measurements on both the mineralized and non-mineralized rocks used in this study. However, more testing of the measurement apparatus is recommended to assess its reliability for very highly resistive samples. ItemInvestigating the genetic structure of Atlantic Cod (Gadus morhua) spawning populations following the collapse of the northern cod stock(University of New Brunswick, 2019) Gormley, Ty; Pavey, ScottThe Atlantic cod (Gadus morhua), within the Northern cod stock, once served as the economic pillar for Newfoundland and Labrador. After years of overfishing and reduced ocean temperature, the stock population collapsed in 1992, driving many to question the genetic structure for its recovery. Currently, the metapopulation and isolation hypotheses have been proposed to describe the genetic structure of the stock, but there is much debate on which is reliable. The stocks genetic structure will be determined using fin clips obtained from 2001- 2003, from various spawning populations, to indicate whether the stock exhibits panmixia. A double-digest restriction site associated DNA technique was used to identify 846 single nucleotide polymorphisms, and the population structure was determined using the Fixation Index (FST). The FST analysis found no significant differences, therefore, spawning populations of the stock are panmictic. Further research is necessary to obtain a more robust genetic structure for extensive ecological management. ItemInvestigation of antimicrobial activity of Canadian medicinal plant extracts(University of New Brunswick, 2018) Dao, Khoi Thien; Gray, Christopher; Johnson, JohnMethanolic extracts of seven Canadian medicinal plants were investigated for antimicrobial activity against a Gram-positive bacterium (Staphylococcus aureus), a Gram-negative bacterium (Pseudomonas aeruginosa), and a fungal organism (Candida albicans). Chamerion angustifolium extract was highly bioactive against S. aureus and P. aeruginosa; Crataegus sp. extract was moderately bioactive against S. aureus, but had a low bioactivity against C. albicans. The extract from Betula papyrifera had a low bioactive against both S. aureus and C. albicans. The active constituents of C. angustifolium, Crataegus sp., and B. papyrifera were detected via separation using two-dimensional thin layer chromatography followed by testing against S. aureus using bioautography. This is the first study to report antimicrobial activity of Crataegus sp. native to Canada and first study to find the antimicrobial constituents of C. angustifolium and B. papyrifera. ItemIonoregulation in the cold: a possible barrier to freshwater colonization?(University of New Brunswick, 2018) Dougay, Brett; Speers-Roesch, BenTo test if ionoregulation in winter cold is a barrier to freshwater colonization at high latitudes in fishes, I investigated the ionoregulatory responses of euryhaline marine-adapted Mummichogs (Fundulus heteroclitus) and freshwater-adapted Banded killifish (Fundulus diaphanus) held in freshwater at 14°C and 0, 4, 14, and 28 days of exposure to winter temperature of 4°C. I predicted that the Banded killifish would be able to maintain their ionoregulation better then Mummichogs in the cold freshwater. I measured maximal activities of gill Na+-K+-ATPase and H+-ATPase, two key ionoregulatory enzymes, and plasma chloride concentrations as a measure of osmotic status. There were no significant differences between species and no effect of cold acclimation on plasma chloride or enzyme activities. The lack of ionoregulatory perturbation by winter cold in either species, especially the seawater-preferring mummichog, do not support the hypothesis that ionoregulation in winter is a barrier to freshwater colonization in fishes. ItemIs there geographic variation in development rate of American lobster (Homarus americanus) embryos?(University of New Brunswick, 2018) Mawer, Kalen; R. Rochette; L. ZouAmerican lobster fisheries in Canada are managed via Lobster Fishing Areas, which are divided based on sociopolitical considerations rather than biological stocks. Bio-physical models use physical and biological parameters to predict larval dispersal and contribute to understanding the identity of stocks, and the connectivity between management areas. Hatching time of lobster embryos is an important parameter of these models, as it impacts the survival and transport of larvae. This study aims to determine whether embryo development functions used to predict hatch need to be “location-specific”. We sampled eggs from six locations in eastern Canada, reared them in the lab, and photographed them weekly to track embryo development based on changes in eye size. The results suggest that embryo development functions do not need to be developed for individual fishing ports, but that distinct development functions for larger marine systems may improve larval dispersal modelling and sustainable management of fisheries. ItemIsolation and identification of the bioactive natural product A-26771B from an endophytic Penicillium expansum isolate(University of New Brunswick, 2020) Forgrave, Kirstyn A.; Gray, ChristopherNatural products are an important source of bioactive compounds and endophytic fungi derived from marine algae represent an under-investigated source of natural products. The objective of this research was to isolate and confirm that an extract from an endophytic Penicillium expansum contained the natural product A-26771B. The natural product was tentatively detected, using high-resolution electrospray ionization mass spectroscopy data, in a methanolic extract from the endophyte. Despite repeated rounds of high performance liquid chromatography and multiple fermentations of the endophyte, the compound was isolated in sub milligram quantities and identified using proton nuclear magnetic resonance data. However, prior to obtaining carbon nuclear magnetic resonance data that would confirm the identification of A-26771B the natural product degraded. Future work should include isolating more of the molecule A-26771B to determine the bioactivity of the molecule against Mycobacterium tuberculosis and Mycobacterium smegmatis. ItemMid-to Late Holocene changes in the hydrographic conditions in the Baltic Sea, as inferred from dinoflagellate cysts assemblages(University of New Brunswick, 2017) Manley, Sander; Limoges, AudreyDinocyst assemblages from marine sediments in the south-central Baltic Sea provide a record of changes in the Holocene Baltic Sea hydrographic system for the last 6000 years. A low diversity assemblage of four genera of autotrophic dinocysts is observed throughout, dominated by the species Operculodinium centrocarpum. Dinocyst assemblages, especially process length variation in O.centrocarpum are used to interpret qualitative paleosalinity. The Littorina Transgression, a period of increasing salinity was already underway in the eastern Gotland Deep by 6000 years BP, and continued until 4750 years BP. The highest dinocyst concentrations were observed during Mid Holocene Warming 6000 - 4000 years BP. Littorina Sea A Phase (6000 - 4750 years BP) is defined by an inferred major increase in salinity. From 4750 - 1000 years BP, only minor changes in salinity are reflected in the dinocyst assemblage. From 4000 - 1000 years BP, stable, low concentrations of dinocysts are interpreted as a result of shorter blooming seasons during Neoglacial summers. Littorina Sea B Phase (4750- 1000 years BP) is defined by inferred minor fluctuations in salinity and stable concentrations of dinocysts throughout. Increased dinocyst abundance is observed from 1000 - 800 years BP before declining from 800 - 100 years BP to low concentrations (25 000 dinocysts/g sediment). This is interpreted as caused in part by longer, warmer summers during the Medieval Warm Period (MWP) and shorter, cooler summers during the Little Ice Age as well as increased nutrient runoff into the Baltic Sea from increased anthropogenic land use during the MWP. Dinocyst assemblages indicate gradually decreasing salinity from 1000 - 100 years BP. Late Littorina Sea B Phase (1000 - 100 years BP) is defined by an inferred minor decrease salinity and elevated concentrations of dinocysts during the MWP.