UC Research Repository
Nau mai, haere mai, welcome to the UC Research Repository
The UC Research Repository collects, stores and makes available original research from postgraduate students, researchers and academics based at the University of Canterbury.
Communities
Select a community to browse its collections.
- Items from Journals and Conferences hosted by the University of Canterbury
- University of Canterbury Research Centres
Recent Submissions
Genetic parameters of essential-oil traits for Eucalyptus bosistoana
(2023) Rajapaksha C; Apiolaza L; Squire M; Altaner, Clemens
A Eucalyptus bosistoana breeding trial established in New Zealand to select plants with improved
growth and wood properties was assessed for essential-oil traits. Mature leaves of 8-year-old
E. bosistoana were collected from 1901 trees representing 85 families. Twenty compounds were
quantified in these samples. Heritability estimates (h2
) of the quantified essential-oil compounds
ranged from 0.06 to 1.14, with the most abundant compounds 1,8-cineole, aromadendrene and the
unidentified compound 8 showing the highest h2 of 0.78, 1.14 and 0.59, respectively. Total oil content
of the leaves had moderate (0.25) heritability. The estimated negative correlation between total oil
content and 1,8-cineole concentration at the phenotypic and genetic levels (rp = –0.44 and rg = –0.70,
respectively) implies that families with higher-quality oil had less oil in the leaves. 1,8-cineole was
genetically negatively correlated with myrcene (rg = –0.74), α-pinene (rg = –0.71), linalool (rg = –0.90),
aromadendrene (rg = –0.94), trans-pinocarveol (rg = –0.75) and the unknown compounds 3
(rg = –0.91), 6 (rg = –0.83), 8 (rg = –0.88) and 9 (rg = –0.75). Seven of the 85 families had breeding
values consistent with the standard commercial oil-quality requirement of over 70% 1,8-cineole. The
results indicate that a breeding program could aid essential-oil production from E. bosistoana.
Fostering inclusion in carceral higher education in Aotearoa
(2023) Mehigan J; Farley, Helen
Effective prevention of palladium metal particles sintering by histidine stabilization on silica catalyst support
(2024) Cahyanto H; Chen X; Lam FLY; Iadrat P; Wattanakit C; Kidkhunthod P; Singh V; Brooker S; Pang S; Choi J; Yip, Alex
A robust method for enhancing the dispersion and stabilization of small metal nanoparticles
in heterogeneous catalysts is developed. It involves in situ complexation of palladium(II) by
histidine, in water, prior to impregnation in fumed silica. TEM images show that the histidine
facilitates dispersion of the Pd(II) into finer nanoscale particles (2 nm) uniformly distributed on
the support, rather than the large clusters (5 nm) seen in the absence of histidine. After hydrogen
reduction, assessments using CO chemisorption and propylene hydrogenation indicate that the
coordinated histidine might obscure the active sites on the Pd particles. However, as histidine
decomposes between 220-300°C in air, these materials were treated at 225°C in air for 48 h.
Afterwards the Pd(II) particles remain the same size, but after hydrogen reduction, there is a 2.4-
fold increase in CO gas adsorption, indicative of an expanded Pd surface area. Furthermore,
superior catalyst stability (activity >200 h) is observed during propylene hydrogenation at 250°C.
This is consistent with histidine use having generated widely spaced, uniformly small, Pd
nanoparticles on the silica support which is expected to help prevent agglomeration (sintering)
during catalysis. This is a convenient low-cost strategy for reducing metal content, preventing
sintering and optimizing catalyst performance.
Trace gas oxidation sustains energy needs of a thermophilic archaeon at suboptimal temperatures
(Springer Science and Business Media LLC, 2024) Leung PM; Grinter R; Tudor-Matthew E; Lingford JP; Jimenez L; Lee HC; Milton M; Hanchapola I; Tanuwidjaya E; Kropp A; Peach HA; Carere, Carlo; Stott, Matthew; Schittenhelm RB; Greening C
Diverse aerobic bacteria use atmospheric hydrogen (H2) and carbon monoxide (CO) as energy sources to support growth and survival. Such trace gas oxidation is recognised as a globally significant process that serves as the main sink in the biogeochemical H2 cycle and sustains microbial biodiversity in oligotrophic ecosystems. However, it is unclear whether archaea can also use atmospheric H2. Here we show that a thermoacidophilic archaeon, Acidianus brierleyi (Thermoproteota), constitutively consumes H2 and CO to sub-atmospheric levels. Oxidation occurs across a wide range of temperatures (10 to 70 °C) and enhances ATP production during starvation-induced persistence under temperate conditions. The genome of A. brierleyi encodes a canonical CO dehydrogenase and four distinct [NiFe]-hydrogenases, which are differentially produced in response to electron donor and acceptor availability. Another archaeon, Metallosphaera sedula, can also oxidize atmospheric H2. Our results suggest that trace gas oxidation is a common trait of Sulfolobales archaea and may play a role in their survival and niche expansion, including during dispersal through temperate environments.
Unethical practices in response to poor student quality: An Australian perspective
(2016) Steenkamp, Natasja; Roberts R
The purpose is to ascertain accounting academics’ perceptions whether (a) the standard of accounting
education at Australian universities has deteriorated, (b) the quality of undergraduate students has
deteriorated in recent years, and if the latter (c) impacted them, their jobs, their teaching and ethical
practices, and (d) is obstructing the attractiveness of accounting academia as a career. An on-line
survey was sent to accounting academics at 39 Australian universities to investigate participants’
perceptions about the deterioration in the standard of accounting education and the quality of
undergraduate students and the impact on respondents’ well-being, ethical practices and their job
satisfaction. The majority of respondents believe the standard of accounting education and the quality
of undergraduate students have deteriorated. Many academics have experienced increased
frustration, disillusionment, and struggle with workload. Respondents experience institutional
pressures to achieve higher pass rates, deal with sub-par core skills, treat students as clients and
increase student retention. As a result, a significant number of academics, have inflated grades or
deflated coursework in order to ameliorate these pressures. Nonetheless, despite these challenges,
the majority is not actively seeking to change jobs or leave academia, but agree that it is not a good
time for others to aspire an academic career in accounting.