Otago University Research Archive
Not a member yet
10699 research outputs found
Sort by
Dietary calcium intakes and major contributing food sources of adolescent males in New Zealand
No full textBackground: Calcium plays an important role in optimising bone health. Sufficient intakes are especially important during periods of growth and development, to ensure the attainment of peak bone mass- a strong predictor of later life fracture and osteoporosis risk. Adolescents have among the highest dietary calcium requirements of any lifecycle group, with an estimated average requirement of 1050 mg/day. The high calcium requirements necessary for this lifecycle group creates challenges in achieving a sufficient intake, especially when coupled with the changes in dietary patterns associated with this life period. Usual daily calcium intakes and the prevalence of inadequacy among New Zealand male adolescents is currently unknown, with the last available data captured over a decade ago. Moreover, the wider implications of changes in food consumption and supply over this period, in particular, the downward trend in consumption of milk and dairy products, could have an influence on the dietary calcium intakes of adolescents.
Objective: To determine usual dietary calcium intakes, major contributing food sources of calcium, and examine specific dietary habits known to influence calcium intakes of New Zealand male adolescents aged 15-18 years.
Design: The present study used data from a cross-sectional, multi- site survey of 135 adolescent males (15-18 years), recruited across 6 New Zealand high schools between February and March 2020. Socio-demographic and dietary habit data were collected using online questionnaires and weight and height were taken for calculation of body mass index. Dietary intake data was obtained via two 24-hr diet recalls, with the multiple source method (MSM) used to adjust for usual calcium intake. The estimated average requirement (EAR) cut-point method was applied to estimate the prevalence of inadequate calcium intake.
Results: The usual median (IQR) of calcium intakes of the sample population were low, 935 (656, 1222) mg/day . The prevalence of inadequacy was high (63%), with Asians, and those residing in low deprivation neighbourhoods identified as being at increased risk of calcium inadequacy (76% and 71%, respectively). Energy intakes appeared positively related to calcium intakes, as evident by concurrently high energy and calcium intakes among various subgroups. Milk was widely consumed among participants (77%) and as such, was the most valuable source of calcium, contributing nearly one-third (28%) to total calcium intakes of the sample population. Additional calcium contributing food groups included cheese (11%), bread (8%), bread-based dishes (6%) and non-alcoholic beverages (6%). The highest dietary calcium intakes were demonstrated among participants who reported frequently consuming milk and dairy products (several times per week, daily, or multiple times per day) and breakfast (everyday), and avoided sugar-sweetened beverages (non-consumers or rarely consumed).
Conclusion: The reported intakes of calcium were suboptimal in our sample of adolescent males, resulting in a high percentage of the population not meeting current recommended intakes. Improved calcium intakes were reported among frequent consumers of milk, dairy and breakfast, and those who avoided sugar-sweetened beverages. Given the consequences associated with failure to achieve sufficient calcium intakes during this period, a nationally representative investigation of the calcium intakes of NZ adolescent males is required, allowing for discernment of whether there is need for further interventions to address this nutritional concern
Added sugar intakes and food sources in New Zealand adolescent boys aged 15-18 years
No full textBackground: High added sugar intake is often associated with increased body weight and oral health problems. Despite media attention over the past few years, added sugar intake in adolescents was last assessed using the data from the New Zealand Adult Nutrition Survey (NZ ANS) 08/09.
Objectives: The aim of this cross-sectional study was to investigate added sugar intake and food sources in adolescent boys enrolled in New Zealand (NZ) secondary schools. The data in this thesis formed part of a nationwide study, the Survey of Nutrition Dietary Assessment and Lifestyle (SuNDiAL) project.
Design: Adolescent boys aged between 15 and 18-year-old enrolled in schools across NZ were recruited via in-school presentations. Once the participants consented, they were required to perform an online questionnaire asking their sociodemographic, health and dietary habits. Anthropometric measurements (height, weight, ulna length) and blood pressure were measured at schools. Dietary information was taken by performing two 24-hour dietary recalls (first was done in-person, second was done via phone/video call). Dietary data were entered into FoodWorks 9 (Xyris Software Australia Pty Ltd). Multiple Source Method (MSM) was used to adjust for usual intake. Intakes of total sugar and individual sugars (glucose, fructose, lactose, sucrose) were reported. As added sugar variable was unavailable in the Foodfiles 2018 database, the amount of sucrose reported in this study was interpreted directly to be assumed added sugar. Natural sugar was calculated by deducting the amount of assumed added sugar from total sugar.
Results: The ethnicities distribution in this study was made up of 54.1% NZ European, 8.9% Maori, 2.2% Pacific and 30.4% Asian. Approximately 32% of the boys were classified as overweight or obese. The mean (95% CI) intake of total and assumed added sugar were 100 (92, 108) g/d and 44 (39.7, 48.3) g/d respectively. The top five contributing food sources of assumed added sugar were fruit; non-alcoholic beverages; sugar/sweets; cakes and muffins; biscuits. Most of the boys (99%) met the recommendation by the United States Department of Agriculture (USDA) of <10% of total energy intake from added sugar. When assumed added sugar was used in-place of free sugar, only about 4% of them met the conditional recommendation by the World Health Organization (WHO) of <5% of total energy intake from free sugar.
Conclusion: Compared with the last nationally representative nutrition survey, there appears to be a reduction in total and added sugar (sucrose) consumption. The results should be cautiously interpreted given the limitations in measuring added sugar intake. There is also a shift of food sources of added sugar where intake of non-alcoholic beverages has reduced. However, education on food sources of added sugar should still be focused on future nutritional interventions. This inclusion of added sugar as a variable in New Zealand FoodFiles would also provide a more robust estimate of added sugar intakes in this demographic. Therefore, our data collected from a convenience, non-representative sample are suggestive, rather than being definitive, of added sugar intakes in adolescent boys. This uncertainty in intake warrants further research at a nationally representative level. A survey of adolescent attitudes to added sugar could help clarify shifts in consumer purchasing
How to Compute Compensation for the Extinguishment of Native Title in Australia: Northern Territory v Mr A. Griffiths (deceased) and Lorraine Jones on behalf of the Ngaliwurru and Nungali Peoples
No full textThis note explains Northern Territory v Griffiths (‘Timber Creek’), which is a native title case concerning land valuation in the northwestern corner of Australia’s Northern Territory. It is an important case because it is the first to articulate how to compensate Aboriginal and Torres Strait Islander peoples for the extinguishment of native title rights under the Native Title Act 1993.Peer Reviewe
New Zealand and the labour traffic, 1868-1870
No full textSince the days of the discoverers, island people had been kidnapped. Occasionally, they served as interpreters, but principally, they provided cheap labour, and during the early years of the nineteenth century, bêche-demer traders, pearlers, and buyers of sandalwood, often trepanned natives to work their ships. But blackbirding scarcely became a trade until the ‘sixties’ and ‘seventies’, when a large scale plantation economy, essentially dependent on the availability of cheap labour, began in the Pacific. […]
Whereas most of the vessels involved were based on Australian ports, New Zealand owned and operated ships were employed in the labour traffic. New Zealanders were already trading with the islanders in goods, fruit, curios, cotton, and coffee, and few hesitated to enter a more lucrative activity, the trade in labourers. In addition, the geographical proximity of Levuka and Auckland, meant that Fiji had an especial interest for masters of New Zealand vessels. An accurate evaluation as to the extent of the participation by New Zealanders is difficult, but evidence suggests it was considerable. […] [Extract from Introduction
Genetic manipulation of Plasmodium cynomolgi as a model for investigating Plasmodium vivax drug resistance
No full textPlasmodium vivax is the most widely distributed cause of human malaria, and thought to be the most difficult to diagnose and treat. Until recently this species has largely been neglected compared to the most significant cause of fatal human malaria, Plasmodium falciparum. One of the reasons behind this comparative neglect is that, unlike P. falciparum, P. vivax is not amenable to continuous in vitro culture. The absence of a tractable continuous culture method has hampered mechanistic biological studies of P. vivax, and in particular has frustrated the development of methods for the genetic manipulation of this species.
As reverse genetics is the gold standard for the investigation of putative drug resistance markers, our current inability to easily manipulate the genome of P. vivax has impeded our understanding of drug resistance in vivax malaria. Efforts to verify putative markers of drug resistance in vivax malaria are of particular importance given the recent emergence and spread of multiple drug resistance throughout Southeast Asia. To date, the identification of molecular markers of P. vivax drug resistance has wholly relied on ex vivo and clinical drug susceptibility studies. While a range of molecular markers have been proposed, including mutations in mdr1, crt, and dhfr-ts, these phenotypic sensitivity studies are subject to a range of confounding factors (i.e., patient immunity, geographic gene fixation). Until we can verify these putative markers using reverse genetics, our understanding of vivax drug resistance and the mechanistic action of antimalarials against P. vivax will remain obscured.
We have been fortunate to be at the forefront of a revolution in the in vitro continuous culture of P. cynomolgi, a sister species to P. vivax which shares many of its distinctive features (including dormant hypnozoite stages), and a high degree of genetic similarity. Considering the lack of a method for the continuous culture of P. vivax, the use of the P. cynomolgi Berok model provides for an exciting opportunity investigate P. vivax drug resistance markers through reverse genetics. While P. cynomolgi has been transfected with episomal plasmids using ex vivo and in vivo methods, the future of such work, which relies heavily on the use of nonhuman primates, faces increasing ethical and practical obstacles. Although the tractable continuous culture method for P. cynomolgi has resulted in a range of important phenotypic studies, conditions for the genetic manipulation of this species have not been optimised. Indeed, no in vitro episomal or integrative genetic manipulation has been reported in this species.
As no framework existed for the integrative genetic manipulation of P. cynomolgi, we undertook training in a well-established method for Plasmodium genetic manipulation in the Fidock Lab (Columbia University, NY) using CRISPR/Cas9. We used this system to investigate the role of putative drug markers for artemisinin sensitivity, and trained in the construction, selection, and phenotypic assessment of recombinant P. falciparum parasites. This experience allowed us to design a CRISPR/Cas9 system for the genetic manipulation of P. cynomolgi.
Our experience working with the well-established P. falciparum system highlighted the requisite attributes for the successful genetic manipulation of Plasmodium species. These include culture scalability, long term, contamination free culture, and the ability to enrich mature asexual forms for transfection. Therefore, the next focus of this study was to optimise the P. cynomolgi Berok continuous culture for reverse genetics. As many of the conditions used for P. falciparum were not compatible with P. cynomolgi culture, we identified viable alternatives for our model. These included a cost-effective substitution for nonhuman primate serum in culture media (horse serum and Albumax), a combination of antibiotics amenable for contamination prevention in P. cynomolgi cultures (penicillin and cefquinome), and a practical method for schizont enrichment (Nycodenz gradient centrifugation).
These basic culture condition improvements facilitated the first in vitro selection of an episomal expression plasmid in P. cynomolgi. Although initial transfections of episomal plasmids were successfully undertaken using the Bio-Rad Gene Pulser, we found that larger plasmids were more efficiently delivered using the Amaxa Nucleofector 4D. The later system was used to deliver CRISPR Cas9 plasmids for the insertion of P. vivax putative resistance markers in mdr1, dhfr-ts, and k13. Of these, we were only able to successfully insert the mdr1 Y976F mutation, which has been associated with chloroquine resistance in ex vivo and epidemiological drug resistance studies of vivax malaria. This marks the first recorded integrative genetic manipulation of P. cynomolgi. Preliminary phenotypic assays indicate that the Y976F mutation does not alter the sensitivity of P. cynomolgi to chloroquine, mefloquine, or lumefantrine. A small decrease in amodiaquine sensitivity was observed, which requires further investigation.
While this study has demonstrated that P. cynomolgi is amenable to genetic manipulation in vitro, there are some important challenges and concerns relating to this model which still need to be addressed. Nonetheless, the undeniable similarity between the genome and phenotype of P. cynomolgi and P. vivax warrants further investment into the development of a more tractable system for the genetic manipulation of this species
A Probe for Conformational Change of Hsc70 in Mammalian Cells under Stress Conditions
No full textHsc70 is a constitutively expressed member of the heat shock protein family. It has an important role in proteostasis and can stabilise nonnative proteins before being further matured in refolding, disaggregation, and degradation processes. Hsc70 switches between ATP and ADP bound states, and the hydrolysis of ATP drives the reaction for folding of the unfolded peptide. Förster resonance energy transfer (FRET) was used to report this conformational shift.
Creation of the FRET probe used variant 3T of Hsc70, which has three cysteines. One is buried in the conformation, and two are surface exposed on different domains. Maleimide Alexa Fluor (AF) dyes were applied to make covalent additions to the reduced cysteines, and conformational change was tracked by FRET. A luciferase refolding assay showed that although these mutations do not interfere with conformational change, they hinder refolding capabilities with substrate peptides.
Double labelled Hsc70 3T was transduced into HEK293 cells with varying conditions. It was found that unfiltered samples, imaged with Opti-MEM in the wells, and at the suggested PULSin concentration by the manufacturer was enough to detect fluorescence of AF488 and AF594. Heat shock can be used to determine how these conformations differ under stress and has been observed in live cell microscopy. This makes FRET a suitable technique to study conformational change of Hsc70 3T under cellular stress. All steps to establish a method to study FRET in live cells were optimised and could be done if a confocal microscope were available
A Systematic Review of Consumer Perceptions of Smart Packaging Technologies for Food
No full textSmart packaging, an emerging technology in the food packaging industry incorporates both active and intelligent technologies. Consumer demand for natural products and increasingly extended and diverse supply chains required to feed the growing global population, mean that traditional packaging is becoming less capable of meeting the functional demands placed on it. To help ensure the commercial success of proposed smart packaging technologies a thorough understanding of consumers attitudes toward them is required. Understanding the cultural, social and cognitive factors that affect acceptance will help “fine tune” smart packaging development to best meet consumer preferences and needs and ensure that communication about the technologies effectively addresses consumer concerns and educates them on the benefits. This systematic review of 28 peer reviewed journal articles summarizes the current knowledge on consumer acceptance or rejection of active and intelligent packaging, and the behavioral forces behind those attitudes. Articles containing primary data and published in the English language over the last 10 years reporting consumer responses to active and/or intelligent packaging technologies in general or to more specific technologies that achieved the functional goals of active or intelligent packaging were obtained and analyzed for themes in the qualitative data analysis software NVivo. Themes were organized into groups as to whether they identified control variables, moderating variables, barriers or motivations to purchase and the benefits of the technology. To develop a conceptual framework for understanding consumer preferences for smart packaging, the identified themes were integrated with several consumer behavior models including the theory of planned behavior and an attitude model. Consumer perceptions of smart packaging is a poorly covered research area with most research being clustered in Europe and a smaller cluster in the Americas so there were significant opportunities to build on the body of knowledge
Chinese consumers’ perceptions of immune health and immune-boosting remedies including functional foods
No full textTo facilitate the successful design of functional foods designed to boost immunity and to guide the successful promotion of such products, to Chinese consumers, fundamental knowledge is required on how consumers perceive the concept of immunity, the steps they take to improve their immunity and what their general attitudes are toward new functional food products. To explore these issues, focus groups (n = 4) and in-home semi-structured interviews (n = 12) were conducted in Shanghai. Immunity was understood to be the defense system that protects the body, with perceived causes for poor immunity including irregular lifestyles, polluted air, and increased age. Participants believed that immunity could be changed by modifying their diet with either conventional or functional foods (including TCM-based foods), supplements (TCM or non-TCM containing), TCM medical gels, TCM patent medicine, and Western medicine all playing varying roles at enhancing immunity and protecting health at different stages of wellbeing
“I don't like wonky carrots”- an exploration of children's perceptions of suboptimal fruits and vegetables
No full textChildren's perceptions of suboptimal fruits and vegetables have not been studied in the suboptimal foods domain. Using two qualitative research methods, this study investigates children's (N = 97) edibility perceptions of suboptimal produce with varied appearance defects. The results show that unlike adult samples previously studied, children are more accepting of suboptimal produce. Defects in shape, size, and certain colour defects were positively perceived, reflecting retailers' opportunities to market suboptimal produce. High levels of brown discolorations and superficial blemishes were not acceptable, implying that produce with such defects could be repurposed as ingredients in foods prepared and sold in-store. These implications reflect retailers' opportunities in marketing suboptimal produce to children, who by their familial influence may also be able to get families to buy and consume suboptimal produce. The importance of familiarity in improving suboptimal food acceptance is also recognised for future research to explore
Consumers’ Behaviors and Attitudes toward Doggy Bags: Identifying Barriers and Benefits to Promoting Behavior Change
No full textThis study identifies barriers and benefits of consumers’ current doggy bag behaviors and provides the information required to run an effective community-based social marketing campaign encouraging consumers to take their uneaten restaurant and café food home. This is done by applying a two-stage methodology, including quantitatively analyzing existing survey data and qualitatively investigating focus group discussion. Multiple barriers to widespread doggy bag participation were common and varied for different individuals and included both convenience and social stigma-related factors. The rational appeal of “saving money” was found to be the most effective motivator for encouraging doggy bag usage, especially for women, young people, students/unemployed, and low-income earners. Social marketing strategies and behavior change tools can be developed to remove the barriers and enhance the benefits of using doggy bags, such as developing positive social norms around using doggy bags and highlighting the financial incentive of using them. This research contributes to a limited but growing literature on out-of-home food waste and provides practicable insights for both public policy and for the food service sector for future initiatives aiming to reduce food waste