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A qualitative study on how New Zealand consumers understand, perceive and use nutrition and health claims on food labels
No full textBackground: Nutrition and health claims are voluntary statements on the front-of-pack of food labels and in advertising regarding the nutrition content of the food or how it relates to health. In New Zealand and Australia, nutrition and health claims are regulated by Food Standard 1.2.7, introduced in 2013. Despite 59% of New Zealand packaged food items displaying a nutrition or health claim there is a lack of knowledge about how New Zealand consumers understand, perceive, and use nutrition and health claims in their food purchasing decisions. It is essential to understand how New Zealand consumers view and use nutrition and health claims to inform policy makers and public health officials in order to ensure that the current legislation is fulfilling its role.
Objective: This study aims to investigate how New Zealand consumers understand, perceive and use nutrition and health claims on packaged food labels.
Design: Primary food shoppers living in Dunedin, Wellington, and Nelson were recruited for this two-phase qualitative research project. Phase one comprised of ten semi-structured individual online interviews exploring how consumers understood, perceived and used nutrition and health claims. The semi-structured interviews contributed to the dataset, although, their primary purpose was to aid in the development of an effective focus group question guide. Phase two included seven focus groups in Dunedin, Wellington, and Nelson (n=39). All interviews and focus groups were transcribed verbatim and analysed using reflective thematic analysis using NVivo 12 software.
Results: Four themes were created from the ten semi-structured interviews; key factors influencing food shopping, consumer knowledge and understanding, consumer use of nutrition and health claims, and trust and scepticism. Five themes were discovered from the seven focus groups; key motives and influencers of product choice, suspicion and scepticism of claims, claims leading to confusion and lack of clarity, how claims help guide food choice, and not all claims are equal. The overarching findings were: nutrition and health claims were not frequently used in food shopping, other factors such as food price, preference and habit were more important in food choice behaviour, consumers were confused by claim meanings, and claims were perceived as 'marketing messages' that were mistrusted. However, specific claims were used by participants with dietary restrictions.
Conclusion: This qualitative study's findings indicate that nutrition and health claims do not factor highly in consumers’ food choice behaviour. Consumers lack understanding of the claims’ meanings, and most participants perceived nutrition and health claims with mistrust, scepticism and suspicion. However, the claims were used and helpful for consumers that had specific dietary requirements. The recommendations from these findings are; to consider formulating changes to Standard 1.2.7 to ensure that nutrition claims are transparent and do not mislead the consumer, implement nutrition profiling in products which display nutrition claims, and to initiate a health promotion approach to increase consumer knowledge of claim regulations
Self-immolative Linkers in Prodrugs and Antibody Drug Conjugates in Cancer Treatment
Get PDFBackground: The design of anticancer therapies with high anti-tumour efficacy and reduced toxicity continues to be challenging. Anti-cancer prodrug and antibody-drug-conjugate (ADC) strategies that can specifically and efficiently deliver cytotoxic compounds to cancer cells have been used to overcome some of the challenges. Key to the success for many of these strategies is a self-immolative linker, which after activation can release the drug payload. Various types of triggerable self-immolative linkers are used in prodrugs and ADCs to improve their efficacy and safety.
Objective: Numerous patents have reported the significance of self-immolative linkers in prodrugs and ADCs in cancer treatment. Based on the recent patent literature, we summarise methods for designing the site-specific activation of non-toxic prodrugs and ADCs in order to improve selectivity for killing cancer cells.
Methods: In this review, an integrated view of the potential use of prodrugs and ADCs in cancer treatment are provided. This review presents recent patents and related publications over the past ten years to 2020.
Results: The recent patent literature has been summarised for a wide variety of self-immolative PABC linkers which are cleaved by factors including responding to the difference between the extracellular and intracellular environments (pH, ROS, glutathione), by over-expressed enzymes (cathepsin, plasmin, β-glucuronidase) or bioorthogonal activation. The mechanism for self-immolation involves the linker undergoing a 1,4- or 1,6-elimination (via electron cascade) or intramolecular cyclisation to release cytotoxic drug at the targeted site.
Conclusion: This review provides the commonly used strategies from recent patent literature in the development of prodrugs based on targeted cancer therapy and antibody-drug conjugates which show promise in therapeutic applications.Peer Reviewe
Challenge, Constraint and Committment to Change: A New Zealand Consumer Lifestyles Study
Get PDFThe current Consumer Lifestyles segmentation study is the seventh major survey of this type carried out in the Department of Marketing at the University of Otago. As with previous iterations, the 2020 Lifestyle Study is designed to provide insights into the lifestyles, consumption patterns and choices, and behavioural trends of New Zealanders.
The New Zealand Consumer Lifestyles Reports provide detailed snapshots of the unique behaviours, attitudes and spending patterns of consumers. In addition to covering important core topics like household disposable income, savings and credit, and home ownership, the reports also contain statistics on more specific consumer-related topics such as eating and drinking habits, decision making factors, product preferences, and descriptions of how consumers spend their leisure and recreation time.
The report discusses the major social and demographic trends since the 2015 study to inform and contextualise the changing attitudes and behaviours of New Zealand consumers. The Report then introduces the six lifestyle segments identified in the study: Financial Strugglers, Traditional Family Values, Educated Liberals, Uncertain Young, Contemporary New Zealanders, and, the Disengaged. The discussion of the segments provides a number of new and useful insights into the contemporary world of the New Zealand consumer
Change, Challenge and Choice: A New Zealand Consumer Lifestyles Study
Get PDFThe current Consumer Lifestyles segmentation study is the sixth major survey of this type carried out in the Department of Marketing at the University of Otago. As with previous iterations, the 2013 Lifestyle Study is designed to provide insights into the lifestyles, consumption patterns and choices, and behavioural trends of New Zealanders.
The report is based on responses to almost 600 questions about consumer attitudes, opinions and behaviours collected from NZ respondents. Data was collected from 2036 individuals in late 2013 using an on-line questionnaire covering a range of psychographic, consumption and lifestyle questions. Gathering responses was contracted to a commercial Australasian market research company. Our instructions were that the respondents should be over the age of 18 years and demographically representative of the New Zealand population in terms of age, sex, education, ethnicity and income.
The research design is based on previous studies carried out by the University of Otago in 1979, 1989, 1995, 2000 and 2005. Over the six iterations of the NZ Consumer Lifestyles survey, additional questions have been added to reflect new social trends, and some questions deleted to ensure the survey’s ongoing relevance. Innovations in the current study include a focus on food and drink consumption, sustainable consumption behaviour, and happiness and well-being measures. It is also the first study to use an on-line survey to gather data.
As a preface to the current findings, a summary is provided of some of the major social and demographic trends since the 2005 study to inform and contextualise the changing attitudes and behaviours of New Zealand consumers
Physiology and pharmacology of the brushtail possum gastrointestinal tract: Relationship to the human gastrointestinal tract
No full textOral formulations are typically based on studies from eutherian animal models. This review introduces information relating to oral formulations for a marsupial species, the Australian brushtail possum (Trichosurus vulpecula) that have arisen from research into new methods for controlling this species, a major vertebrate pest in New Zealand. Morphologically, the gastrointestinal tract of the possums is similar to that of hindgut fermenting eutherian species, but there are some striking differences in function. Limited data suggests that the pharmacokinetics and bioavailability of administered drugs is similar to that in eutherian species, but there is some evidence that possums may have specific mechanisms for handling the intake of plant toxins and xenobiotics. The development of oral formulations for a free-ranging pest species presents several challenges above those encountered in the development of therapeutic formulations for humans and domestic animals. Use of a marsupial animal model may lead to new strategies for oral formulations in humans.Peer Reviewe
The future of red meat farming in New Zealand: An independent sector analysis focussing on the future prospects of the industry given low profitability and high capital input costs
No full textNew Zealand’s association with farming extends right back to the time of European colonisation with small farms dominating the economic landscape for the greater part of the country’s existence since the 1850s. While agriculture is still a significant contributor to New Zealand’s gross domestic product, the relative importance of red meat farming has been slowly reducing as other industries (both farming and otherwise) rise to prominence. Meat processor woes were well documented in their annual reports, but were farmers right in saying that it was getting progressively harder for them to make ends meet? If both the farmers and meat processors were facing profitability issues, was the future of the industry uncertain? It was to this end that a longitudinal dataset of financial and non-financial information relating to five-hundred plus farms across New Zealand was analysed. The dataset showed that profitability was low, asset values high and consequently return on assets was very low. It showed that not only were farmer complaints around profitability real, this was an issue that had existed for decades. If farmer profitability was a historical issue, then why had farmers not exited the industry earlier? The answer to this question lay in understanding the psyche of the New Zealand farmer, a task that was fulfilled by analysing the historical background of the industry and from discussions with a carefully selected panel of experts. Moreover, what did the low profitability and high land values mean for small family farms in the future?
The research, undertaken with a strong social purpose in mind, showed that a contraction in dedicated red meat farms was inevitable. There was also the possibility that the New Zealand landscape might change from one that was dotted with small family farms to one that was made up of large family conglomerates – a far cry from the ‘one farm, one family’ concept that built the nation. The question then becomes one for government policy – are small farms meant to be saved or will the free market economy take its course and irrevocably change the farming ownership landscape in New Zealand
Large earthquake recurrence in low seismicity regions: Accounting for aperiodicity
No full textIn this thesis I investigate the recurrence of large earthquakes in low seismicity regions. A number of previous studies have found evidence that suggests large earthquakes recur less regularly on low activity-rate faults than their more active plate-boundary counterparts. This represents a departure from the quasiperiodic earthquake recurrence predicted by elastic rebound theory, and poses challenges for how the seismic hazard posed by faults in low seismicity regions should be characterised.
Here I firstly compile a global dataset of 80 long-term earthquake records from different tectonic regions. I characterise the variability of earthquake inter-event times in this dataset using the burstiness and memory coefficient measures. I find that the majority of Earth's well-studied faults shows weakly periodic and uncorrelated large earthquake recurrence, consistent with the expectations of elastic rebound theory. However, many low activity-rate faults show random or clustered earthquake recurrence, which cannot be easily explained by elastic rebound theory. This study is presented in Chapter 2 of this thesis.
I then use the Otago range and basin province of southern New Zealand as a case study of a low activity-rate fault system. Previous studies from this region have proposed that large earthquakes recur episodically, with individual faults going through active and quiescent phases, making the region an important case study of earthquake recurrence in low seismicity regions. I expand our knowledge of the distribution of earthquake inter-event times and fault slip rates in the region through the collection of new data.
I undertake the first paleoearthquake investigations of the Hyde Fault, a major fault in east Otago, finding evidence for four paleoearthquakes since ~65 ka. Optically stimulated luminescence dating constrains the timing of the earliest event (Event D) to around 47.2 ka (37.5 – 56.7 ka at 95% confidence), Event C to around 34.6 ka (24.7 – 46.4 ka at 95% confidence), Event B to around 23.5 ka (19.7 – 27.3 ka at 95% confidence) and the most recent event (Event A) to around 10.5 ka (7.9 – 13.1 ka at 95% confidence). The earthquake record for the Hyde Fault does not show evidence for episodic earthquake recurrence. This finding contrasts with previous paleoearthquake studies of two other faults within the fault system, the Dunstan and Akatore faults, that have suggested earthquakes recur episodically on these faults. The results from the Hyde Fault demonstrate that episodic earthquake recurrence is not ubiquitous in Otago, and suggest that diverse recurrence behaviours may coexist within the same fault system. This study is presented in Chapter 3 of this thesis.
I then obtain the first constraints on late Quaternary incremental fault slip rates in the Otago region using 10Be cosmogenic radionuclide dating of faulted alluvial fan surfaces on the Hyde and Dunstan faults. I determine a slip rate of 0.27 mm/yr (0.22 – 0.34 mm/yr at 95% confidence) for the Hyde Fault since 115 ka and a slip rate of 0.16 mm/yr (0.12 – 0.20 mm/yr 95% confidence) for the Dunstan Fault since 320 ka. Both faults show deviations from a constant linear slip rate through time, with slip rates varying by a factor of 2 – 4 over timescales of 15 – 80 kyr. Increases in slip rate are out of phase on the two faults, supporting a hypothesis that strain is shared within the fault system over timescales on the order of 10s – 100s kyr, although neither fault shows evidence for long periods of seismic quiescence. This study is presented in Chapter 4 of this thesis.
The diversity of recurrence behaviour evident in the paleoearthquake and slip rate records from the Hyde and Dunstan faults poses challenges for how the hazard posed by these faults should be characterised. To address this problem, I present a novel Bayesian method for developing time-dependent models of earthquake recurrence that does not rely on a priori assumptions of quasiperiodic earthquake recurrence. Using the additive property of the Brownian passage time distribution, I make inference on the model parameters jointly from paleoearthquake and cumulative fault offset data. Monte Carlo Markov Chain methods are used to sample the posterior distribution of model parameters, which are subsequently used to forecast earthquake probabilities. These forecasts fully account for uncertainties in the data and model parameters. The method is demonstrated for the Hyde and Dunstan faults using the data collected in Chapters 3 and 4, along with previously reported data. This study is presented in Chapter 5 of this thesis.
Together, the findings of this thesis show that large earthquake recurrence in low seismicity regions is a complex process, and does not conform to the patterns of quasiperiodic recurrence observed in many plate-boundary regions and supported by elastic rebound theory. While some low activity-rate faults show evidence suggesting episodic earthquake recurrence (e.g. the Dunstan Fault), others do not (e.g. the Hyde Fault). Because the physical processes controlling rates of strain accumulation and release in low seismicity regions are poorly understood, statistical models of earthquake recurrence should avoid strong a priori assumptions about the distribution of earthquake inter-event times. The Bayesian method for modelling earthquake recurrence that I present here uses a purely data-driven approach to account for aperiodicity. I argue that this data-driven approach is the most reasonable approach to take given our present understanding (or lack thereof) of the complex processes controlling earthquake recurrence in low seismicity regions
Soil microbiome dynamics and responses to climatic changes in isolated New Zealand soils
Get PDFThe soil microbiome provides large amounts of taxonomic and functional diversity to ecosystems and is considered one of the most diverse natural environments on earth. The functions associated with the soil microbiome are closely linked to the taxa that make up the microbial community. Understanding how environmental factors influence the structure of soil microbial communities through space and time can provide key information for biogeochemical processes such as nutrient cycling and also provide insights into how the soil microbiome might respond to changes in climate. To understand how a soil microbial community will respond to changes in its environment, it is necessary to first understand the structure and composition of a baseline soil microbial community. This work assessed the baseline soil microbial communities of subantarctic Campbell Island and two tussock grassland sites in alpine Takahē Valley, one site dominated by Chionochloa rubra and the other dominated by Chionochloa teretifolia. These locations are isolated sites, Campbell Island in terms of geographic location and Takahē Valley in terms of minimal disturbance of a grassland site. This will provide useful baseline data for both bacterial and fungal soil communities. Environmental conditions including temperature and nutrient levels in Takahē Valley were also manipulated to simulate the effects of climate change to provide insights into how the soil bacterial and fungal communities in Takahē Valley would respond to changes in abiotic conditions. High-throughput sequencing of the 16S rRNA and ITS2 genes identified significant differences in the bacterial and fungal communities associated with different vegetation types of Campbell Island and also significant differences in the bacterial and fungal communities associated with the two Chionochloa species in Takahē Valley. Furthermore, differences were also seen in the bacterial and fungal communities exposed to increased temperatures and nutrient levels. Statistically significant findings include a higher observed diversity in the bacterial community of C. rubra samples exposed to higher temperatures and an increase of several bacterial and fungal Orders when exposed to higher levels of sugar at either Takahē Valley site. The findings in this thesis contribute to our understanding of the structure of soil microbial communities and the factors that influence them. Additionally, characterising the structure and composition of microbial communities subjected to changes in climatic conditions provides a useful starting point for investigating the functional potential of soil microbial communities through time and space
Modification of stainless steel by grafting of poly(ethylene glycol) copolymers for reduction in protein adsorption and bacterial adhesion
No full textBiofouling, also known as the unwanted attachment of protein, bacteria, and macro-organisms on materials surfaces, has resulted in large economic and ecological consequences in aqueous and marine environments. Biofouling generally creates a film that may cause serious microbial contamination problems, for example, in medical engineering, dentistry, pharmaceutical processes, bioprocessing, and food manufacturing. Stainless steel is used in a large variety of food and medical applications, where it is susceptible to adsorption of proteins and other materials on its surface, ultimately leading to biofouling. Frequent clean-in-place procedures are used to remove these fouling layers in commercial applications.
The intended purpose of this work is to form an understanding and develop a coating to achieve pristine, foulant-resistant stainless steel surfaces in aqueous proteinaceous or microbial environments such as those found in medical implants or in food processing plants. The coating should be inexpensive and non-toxic and must have the ability to inhibit the rate of adhered proteins and bacteria from a metal surface. A simple solution-based method will be used to deposit the coating, which would not require any adhesion promotor, heat treatment, or toxic chemicals.
Chapter 1 provides a general introduction and review of biofouling on surfaces and the various antifouling materials used to minimize it.
Chapter 2 describes the use of stainless steel nanoparticles and their functionalization with poly(ethylene glycol) phosphonic acid polymers. There is an emphasis for a response at the adsorption of the polymer at acidic pHs. However, experiments were also performed at other pHs from 3-11. A comparison was made between the adsorbed polymer film properties on stainless steel nanoparticles and chromium hydroxide particles. It also shows that chromium oxide is an appropriate and useful model for stainless steel.
Chapter 3 describes the synthesis of a range of antifouling polymers based on poly(ethylene glycol) and phosphate, phosphonate, or carboxylic acid monomers as an easily applied nano-coating for stainless steel substrate. The synthesis of polymers was based on the idea if multivalent attachment using copolymers may give more tenaciously bound films to a metal surface than monofunctional materials due to the additive effect of multiple binding sites.
Chapter 4 shows that highly tenacious films can be easily deposited by dipping the stainless steel substrate into a dilute aqueous solution of the copolymer, or by flowing a copolymer solution for a few minutes. This simple attachment method, which does not need solvents, annealing, or adhesion promoters looks to be very easy transferable into commercial applications.
Chapter 5 describes the interaction of a variety of proteins and skim milk on the polymer coated surfaces. It also covers the effect and role of grafting density and surface linkers on the antifouling efficacy of the polymer films. Phosphate-containing copolymers showed almost a 100 % reduction in binding affinity of proteins which was the main aim of the project. The role of surface linkers was also tested by rinsing the polymer films in various aqueous solutions. The films based on phosphate and phosphonic acid linkers resisted rinsing over many days.
Chapter 6 covers two aims of the project. Initially, the polymer films were assessed against two pathogenic bacteria i.e. Escherichia coli and Bacillus cereus. The biofilms were grown in vitro for several days on uncoated and polymer coated stainless steel surfaces. Phosphate and phosphonate coated surfaces exhibited strong inhibition of bacterial adhesion for both Escherichia coli and Bacillus cereus over several days and the formation of a biofilm was observed on uncoated surfaces. Other polymer coated surfaces containing carboxylic acids as surface linkers were also tested but results were not as good as for phosphate and phosphonic acids. The cytotoxicity of the polymer films was tested by several quantitative and qualitative methods, and all polymers revealed excellent non-toxicity which fulfill the aims of the project.
Chapter 7 describes the idea if phosphorus-containing monomers can be polymerized to prepare low-energy-surfaces. It covers the synthesis of a range of new hydrophobic fluorinated phosphorus-containing homo- and copolymers. The polymers were attached to the surface of stainless steel by simple treatment of dilute solutions in trifluoroacetic acid for 30 minutes. The polymer film stability was also determined after rinsing in pure water for 3 weeks. The ease of application and the stability of the films makes this a promising avenue for the synthesis of low surface energy metal surfaces.
Chapter 8 includes the final results and conclusion with future directions of the project
Examining the relationship between tourism and Hector’s dolphins (Cephalorhynchus hectori) at Akaroa Harbour
Get PDFCetacean tourism has grown rapidly over the preceding decades, requiring careful and considerate management. Akaroa Harbour, Aotearoa New Zealand, is a core use area for Hector’s dolphins (Cephalorhynchus hectori) at Banks Peninsula, where this endangered and endemic species has been studied intensively since 1984. Here, Hector’s dolphins are exposed to some of the highest levels of tourism in New Zealand, including dolphin watching, swim-with-dolphin, cruise ship, and recreational vessel traffic. I analysed 2,335 sightings from 8,732 kilometres of survey effort via kernel density estimation to determine hotspots for dolphins within the harbour and assess stability in distribution over twenty years. A clear, southward shift in distribution occurred between 2005 – 2011 and 2012 – 2015, coinciding with a fourfold growth in annual cruise ship visits to Akaroa Harbour following the 2011 Canterbury earthquakes. The spatial overlap in core habitat between these two periods was just 24% and sightings rate analyses provided further evidence of a distributional shift in correlation with levels of cruise tourism. In order to quantify potential anthropogenic drivers of dolphin distribution, I developed and tested a novel, cost-effective, autonomous monitoring method to accurately quantify fluctuations in vessel traffic at Akaroa during summer 2019 – 2020. This time-lapse camera methodology, in combination with satellite tracking of commercial vessels, proved capable of accurately tracking relative levels of vessel traffic at multiple time scales. 59,296 images were analysed, accurately estimating fluctuations in vessel traffic (highest around midday, on weekends, and in January), total levels of vessel traffic in core dolphin habitat (mean = 40.51 vessels per day), and vessel speed in still images. Dolphin tourism trips composed a significantly larger proportion of vessel traffic during 2019 – 2020 than observed during 2005 – 2008, with generalised additive models (GAMs) revealing cruise ship presence directly led to more such trips. The effect of vessel traffic parameters on distribution during 2019 – 2020 was investigated using a moored passive acoustic recorder at a dolphin hotspot. GAMs revealed that increasing motor vessel traffic, cruise ship presence, and high levels of dolphin tour vessel traffic led to decreases in daily dolphin detections. Findings suggest that Hector’s dolphins at Akaroa have been displaced from core habitat over both short and long time scales in relation to tourism parameters. It must be asked whether cumulative human pressures on the harbour environment have reached unsustainable levels for this taonga species. Future research is warranted to investigate relationships between tourism and population parameters. Management should act with precaution using available tools