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UNB Scholar is an institutional repository initiative of UNB Libraries intended to collect, preserve, showcase, and promote the open access scholarly output of the UNB community. Use UNB Scholar to explore specific collections, or search all content in the repository. Material submitted to the repository will also be freely discoverable online through Google and other major search engines.

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Evaluating the effect of warm mix additive dosage rate on workability of asphalt
(University of New Brunswick, 2023-12) Mudassar, Usama; Sanchez-Castillo, Xiomara
Asphalt concrete construction using hot mix asphalt causes enormous greenhouse gases emissions. Warm mix additives help decrease the production temperatures of asphalt concrete, thus reducing emissions and improving workability at lower temperatures. Generally, the manufacturer recommends the additive dosage rate. This project aimed to study the effect of dosage rate on the viscosity and workability of asphalt. Two asphalt binders, PG 58S-28 and PG 58H-28, with two warm mix additives, Zycotherm and Evotherm, with different dosage rates, were selected. The results of asphalt binder tests showed no significant difference in penetration grade, softening point and rotational viscosity of binder after the incorporation of additives. However, the steady shear flow test did show some reduction in mixing and compaction temperatures in the case of Evotherm. Moreover, densification curves showed additives worked better at an optimum dosage of 0.07% for Zycotherm and 0.4% for Evotherm, achieving a 10°C reduction in compaction temperatures.
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Discovery of natural products from marine derived fungi and endophytic fungi
(University of New Brunswick, 2023-10) Morehouse, Nicholas J.; Gray, Christopher A.
Natural products are an abundant source of bioactive, complex, and diverse chemical structures. This thesis describes the isolation and structure elucidation of natural products biosynthesized by marine-derived fungi and endophytic fungi with the primary objective of the research being the discovery of new chemical structures. The thesis is divided into two parts: the discovery of new natural products and the development of a new dereplication platform. Three fungal isolates were investigated to discover new natural products. First, investigation of a Penicillium sp. fungus isolated from sea foam resulted in the discovery of a new phenalenone derivative that selectively inhibits the growth of Staphylococcus aureus and Mycobacterium tuberculosis. Second, investigation of an Aureobasidium pullulans fungus isolated from needles of Thuja occidentalis (white cedar), led to the isolation of two new C11-polyketides that inhibit the growth of Mycobacterium tuberculosis. Finally, investigation of a Tolypocladium sp. fungus isolated from the marine macroalga Spongomorpha arcta led to the isolation of two new lipopeptaibols that inhibit the growth of Gram-positive bacteria and mycobacteria. Although these five natural products are new, they are structural derivatives of previously discovered molecules rather than being structurally novel. To improve the likelihood of discovering novel natural products in the future, Structural similarity Network Annotation Platform for Mass Spectrometry (SNAP-MS) was developed. SNAP-MS utilizes molecular networking topology and structural similarity fingerprinting to generate annotations of natural product compound families to aid in the dereplication process. This platform addresses limitations of many currently existing tools, such as the lack of publicly available reference data for most natural products and provides a new tool for analyzing complex mass spectrometry experiments that will improve dereplication capabilities and improve the likelihood of discovering novel natural products.
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Impacts of noise on the response to territorial intrusions in hermit thrush (Catharus guttatus)
(University of New Brunswick, 2023-10) Moore, Jennifer L.; Roach, Sean
The obstacle that anthropogenic noise presents to songbird acoustic communication is well understood from the signaler perspective, but less is known about signal receivers. Using playback studies to simulate intruders on territories along a gradient of ‘urbanness’, the impact of both urban noise and experimental noise on hermit thrush (Catharus guttatus) territorial defense behaviour was quantified. Detection of the simulated intruder did not change as a result of urbanness or experimental noise. Responses to the intruder were less aggressive when experimental noise was present, but more swoops were performed near busier roads. As such, the urban anger hypothesis appears to be related to road presence, not noise level. When vocally responding to the intruder, experimental noise, but not urbanness, was associated with increased song amplitude and lower signal to noise ratio. Urban noise is less detrimental to hermit thrush than previously thought, but experimental and urban noise have different impacts.
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The social construction of masculinity and intimate partner violence: Underestimating men’s perspectives
(University of New Brunswick, 2023-11) Meng, Alison Marie; Holtmann, Catherine
This thesis investigates the impact of social constructions of masculinity on men's use of intimate partner violence (IPV), addressing two questions: (1) How do social constructions of masculinity and gender influence men’s use of IPV? and (2) Based on their exposure to patterns of gender interaction, how do men learn and internalize processes that inhibit or encourage using IPV? Using Connell's (Connell & Messerschmidt, 2005), theory of hegemonic masculinity, this study analyzes the Canadian White Ribbon Campaign's "Boys Don't Cry" video through content analysis and employs it as a visual method for qualitative interviews with 16 men aged 19 to 25. Findings reveal some men make conscious choices not to use violence despite social pressures and learn through sensitizing experiences and gendered interactions with men and women that using violence leads to negative consequences. This study allowed for participants to gain more awareness about their conceptualizations of masculinity and IPV.
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The impact of Covid-19 employment insurance policy changes on beneficiary numbers: A regional analysis in Canada
(University of New Brunswick, 2023-12) Makarov, Joshua Ludwig; Chowdhury, Murshed
Over $345 billion was spent in 2020 on Covid-19-related policies in Canada, with $13 billion of that allocated towards Employment Insurance (EI). In September 2020, Interim Order Number 8 Amending the Employment Insurance Act was introduced relaxing requirements by introducing a 13.1% unemployment rate floor to all regions in Canada. This paper estimates the impact of this policy on the number of EI beneficiaries using monthly data on beneficiaries at the EI economic region and provincial level derived from Statistics Canada. My findings suggest a more than doubling of the average number of beneficiaries across regions after the announcement of the policy. This varies as regions’ true unemployment rates diverge from 13.1%, highlighting the policy’s sensitivity to regional market conditions. The implications of this policy urge us to reevaluate the effectiveness of EI in its current state and set a groundwork for future policy decisions during economic shocks.