Studies on the processing of New Zealand grapefruit juice : a thesis presented in partial fulfilment of the requirements for the degree of Master of Technology in Food Technology at Massey University

The likely origin of the New Zealand grapefruit (NZGF) is discussed and present and future trends in its production and utilisation presented. Early and late season samples of NZGF juice were analysed for the presence of the enzymes pectinesterase, polygalacturonase and ascorbic acid oxidase, no trace of the latter two being found. Samples of juice from NZGF harvested at regular intervals from July until December 1973 were analysed for yield, total soluble solids, titratable acidity, pH, pectinesterase activity, and ascorbic acid content. The average yield of juice obtained (35.6% w/w) was significantly lower than that reported from overseas for true grapefruit. The level of total soluble solids remained fairly constant in the range 12.0 to 12.6%, while the pH of the juice increased throughout the season from 2.95 to 3.40. The titratable acidity was within the range 1.0 to 2.0 grams of citric acid per 100 ml of juice, while the Brix : acid ratio varied from 5.02 to 10.03. The level of pectinesterase in the juice (which increased as the season progressed) was comparable with that found in overseas citrus juices, while the level of ascorbic acid in the juice declined over the season from 32.4 to 23.2 mg/100 ml, in agreement with overseas trends. With the exception of yield, the compositional characteristics of NZGP juice reported here do not differ markedly from overseas grapefruit juices. The important role which pectinesterase plays in the destabilisation of citrus juice cloud is outlined and possible methods for inactivating the enzyme are described. As the application of heat is the only method in commercial use, factors affecting and methods for studying the thermal inactivation of enzymes are discussed. As the major objection to most of these methods is the way in which the heating and cooling lags are evaluated, a new method which adequately describes these thermal lags has been developed for determining the thermal resistance of pectinesterase in NZGP juice. A digital computer was programmed to determine (using a trial and error technique) the constants in two expressions which relate the equivalent effect of unsteady state heating and cooling of NZGF juice to the inactivation of pectinesterase. One expression assumed that the rate of inactivation was exponentially related to temperature; in this case the constant was the z value. The other expression assumed that the rate was related to temperature according to the Arrhenius equation, in which case the constant was the activation energy. The two constants were evaluated for both low and high pH juice. It was found that the latter expression using the Arrhenius equation described the change in rate of inactivation with temperature more adequately than the former expression. From these expressions the times required at different temperatures to inactivate pectinesterase in NZGP juice of varying pH were calculated. The application of these results to the industrial processing of NZGP juice is discussed

The Experience of Parental Conflict in Parallel Parenting Custody Arrangements

Within Canada, parallel parenting plans have been introduced to manage parental conflict in cases of high conflict divorce (Epstein & Madsen, 2004). Since parallel parenting plans are a relatively novel form of custody order, limited research exists pertaining to their effectiveness and impact on the lives of families. The purpose of this dissertation was to explore the experience of parallel parenting. However, since participants were reluctant to discuss this experience directly, the focus of this dissertation shifted to the experience of conflict. Individual interviews with eight participants (five mothers and three fathers) with direct knowledge or experience with parallel parenting plans volunteered to participate in this qualitative study. Interviews followed a reflexive-dyadic interview model and were analyzed using thematic analysis. Thematic analysis identified three common themes across the cases: (a) Attributions of responsibility: Self versus other; participants attributed responsibility for the parenting conflict to their former partners; (b) Who knows best; participants believed that they, and only they, knew what was best for their child; neither their former partners nor the court system were recognized as being able to accurately judge this; and (c) Desire for a resolution; the participants believed that they were more motivated than their former partners to desist from conflict; their willingness to cooperate was associated with a reduction in conflict and improved the parenting relationship and post-divorce adjustment of their child. The themes held dramatically different meaning across cases depending on the context of their relationships. Overall, participants reported a reduction in conflict over time. However, the reported reduction in conflict was found to vary with the participants’ level of satisfaction with the imposed arrangement, the quality of conflict in the parenting relationship, and subsequent willingness to cooperate with their former partners. How these variables relate to the parallel parenting custody arrangement remains unknown. Difficulties with research on parallel parenting custody arrangements and directions for further research are discussed

Regulating the Tobacco Retail Environment in New Zealand

Background Tobacco use is a leading risk factor for preventable mortality and causes around 5,000 deaths in New Zealand (NZ) each year. In 2011, the Government committed to making NZ smokefree by 2025, through reducing smoking prevalence and tobacco availability to minimal levels. However, the retail environment for tobacco remains relatively unregulated, with no restrictions on where tobacco can be sold, or requirements for tobacco retailers to be licensed. This thesis examines the potential for regulating the tobacco retail environment to reduce smoking prevalence and achieve NZ’s 2025 goal. Methods This research comprises five distinct projects. The first is a narrative literature review on tobacco retailing and smoking, and potential policy options to regulate the tobacco retail environment. The second project is a systematic review and meta-analysis examining the association between point-of-sale tobacco marketing and smoking. The third and fourth projects involve qualitative research with tobacco control sector key informants and tobacco retailers, in which stakeholders’ views of the tobacco retail environment and regulatory options are examined. The final project is a survey with a complex design to investigate smokers’ perceptions of the relative effectiveness of five policy options to reduce tobacco availability. Results The available evidence suggests that greater access to tobacco retail outlets and exposure to tobacco retail products at the point-of-sale are significant risk factors for youth smoking initiation, and for relapse after a quit attempt among adults. Key informants within the tobacco control sector believe that licensing of tobacco retailers is an important intermediate step in achieving the 2025 goal, and envisage tobacco being available only at a small number of specialised outlets in the long-term. Retailers’ perceptions of potential tobacco retail policies were mixed; some were supportive of measures to reduce tobacco availability and the 2025 goal, though several expressed ambivalence towards licensing policies. Retailers tended to be more supportive of tobacco retail policies where the rationale was to protect children from tobacco-related harm, and where this intention was explicit. Among NZ smokers, of the five policy options to reduce tobacco availability that were tested, two were perceived as most effective: i) tobacco only sold at half the existing liquor stores, and ii) tobacco only sold at pharmacies. Each of these policies was rated more likely to prevent youth smoking initiation, and at least as likely to help smokers to quit, relative to a benchmark policy of continued tobacco taxation. Conclusions In order for the Government to achieve its own goal of reducing tobacco availability to minimal levels by 2025, regulation of the tobacco retail environment is needed. The recent implementation of legislation banning point-of-sale tobacco displays demonstrates that policy interventions in this environment are feasible. The tobacco control sector strongly supports licensing of tobacco retailers and measures to reduce tobacco availability. Retailers are unlikely to strongly oppose these policies, particularly if the public health rationale is clear. Based on smokers’ perceptions, policies that substantially reduce tobacco availability and remove it from smokers’ usual places of purchase could be at least as effective as tax increases, in terms of reducing smoking initiation and supporting cessation

Second generation of AVTIS FMCW millimeter wave radars for mapping volcanic terrain

The second generation AVTIS ground-based millimeter wave instruments designed for monitoring topography of volcanic lava domes are solid state 94 GHz FMCW rastered, real beam radars operating at ranges of up to ~7 km with a range resolution of ~2.5 m. Operating ten times faster than the prototype with reduced power consumption suitable for battery powered portable use as well as installation at a telemetered site under solar power, we examine their performance as tools for monitoring topography over time and report on the operational statistics both as a radar sensor and as a means of generating digital elevation maps.Publisher PD

Incidence of varicose veins, chronic venous insufficiency and venous reflux in the general population and associated risk factors: the Edinburgh Vein Study follow up

Chronic venous disease (CVD) is a common problem in the western world, causes considerable morbidity and has a substantial impact on the health care system in terms of cost of treatment. Most epidemiological research has focussed on the prevalence of varicose veins and ulceration. As such, evidence on the incidence and risk factors is limited. The aim of this study was to measure the incidence of C2 varicose veins, C3-C6 chronic venous insufficiency (CVI) and venous reflux ≥ 0.5 seconds duration in an adult population, and to investigate risk factors associated with the development of these conditions. The Edinburgh Vein Study was a prospective cohort study in which 1,566 men and women aged 18-64 years randomly sampled from the general population underwent an examination comprising clinical and photographic classification of CVD, duplex scanning of the deep and superficial systems of both legs, and completed a questionnaire on lifestyle and medical history. After a 13 year period, invitations were sent to the 1456 survivors to attend a follow up examination. In total, 880 participated in the follow up study, giving a response rate of 60.4%. The overall incidence of C2 varicose veins was 18.2% (95% CI 15.2-21.6), equivalent to an annual incidence rate of 1.4% (95% CI 1.1-1.7). There were no gender differences (p=0.78). Age was associated with the development of new C2 varicose veins the 13 year incidence rose from 9.8% in those aged 18-34 years to 25.7% in those aged 55-64 years (p<0.001). New cases of C3-C6 CVI developed in 9.2% (95% CI 7.0-11.9) of the study sample over 13 years, an annual incidence rate of 0.7% (95% CI 0.5-0.9). There were no gender differences: the 13 year incidence was 10.7% (95% CI 7.2-15.5) and 8.1% (95% CI 5.7-11.6) in men and women respectively (p=0.32). The incidence increased consistently with age, from 2.1% in those aged under 35 years to 17.1% in those aged over 55 years (p<0.001). Of all C3-C6 conditions, C3 corona phlebectatica had the highest incidence (5.3%, 95% CI 3.7-7.5). C5-C6 venous ulceration had the lowest incidence, affecting only 0.5% (95% CI 0.2-1.6) of the study sample over the 13 years. Overall, 12.7% of participants developed new venous reflux ≥0.5 seconds duration from baseline to follow up. The 13 year incidence of superficial, deep and combined venous reflux was 8.8%, 2.6% and 1.3% respectively. Neither age nor sex were associated with the incidence of venous reflux (p>0.05). The highest incidence of reflux was in the great saphenous vein in the lower third of the thigh (4.2%, 95% CI 2.4-7.1). Venous reflux at baseline was associated with the development of new C2 varicose veins at follow up: the incidence creased linearly in those with no reflux, deep, superficial and combined reflux respectively (p<0.001). Family history of venous disease was a significant risk factor for C2 varicose veins (age and sex-adjusted OR 1.7, 95% CI 1.1-2.7) while obesity was associated with the development of CVI (age and sex adjusted OR 4.5 (95% CI 3.3-6.9). Pregnancy appeared to be associated with the development of varicose veins but the association was not statistically significant due to small numbers. No risk factor was associated with the development of venous reflux. The Edinburgh Vein Study is one of a few cohort studies to report the incidence of C2 varicose veins, C3-C6 CVI and venous reflux ≥0.5 seconds duration, and investigate risk factors associated with these conditions. While the results on incidence are consistent with the limited evidence from other studies, the exact effect of risk factors remains unknown. Genetic studies would help clarify whether CVD is an inherited or acquired condition. For other risk factors, results of this study could be combined with other population-based studies in a meta-analysis. The overall estimate of effect would identify the most important risk factors associated with the development of CVD and venous reflux. Finally the natural history and progression of CVD needs to be assessed. The Edinburgh Vein Follow Up Study has examined this relationship and results will help to identify those most likely to progress to more severe disease and, in turn, those who will benefit most from treatment. Appropriate, clinically proven, effective and cost-effective treatments can then be administered in an attempt to reduce the burden of CVD

Effect of testing for cancer on cancer- or venous thromboembolism (VTE)-related mortality and morbidity in people with unprovoked VTE

BACKGROUND: Venous thromboembolism (VTE) is a collective term for two conditions: deep vein thrombosis (DVT) and pulmonary embolism (PE). A proportion of people with VTE have no underlying or immediately predisposing risk factors and the VTE is referred to as unprovoked. Unprovoked VTE can often be the first clinical manifestation of an underlying malignancy. This has raised the question of whether people with an unprovoked VTE should be investigated for an underlying cancer. Treatment for VTE is different in cancer and non‐cancer patients and a correct diagnosis would ensure that people received the optimal treatment for VTE to prevent recurrence and further morbidity. Furthermore, an appropriate cancer diagnosis at an earlier stage could avoid the risk of cancer progression and lead to improvements in cancer‐related mortality and morbidity. This is the third update of the review first published in 2015. OBJECTIVES: To determine whether testing for undiagnosed cancer in people with a first episode of unprovoked VTE (DVT of the lower limb or PE) is effective in reducing cancer‐ or VTE‐related mortality and morbidity and to determine which tests for cancer are best at identifying treatable cancers early. SEARCH METHODS: The Cochrane Vascular Information Specialist searched the Cochrane Vascular Specialised Register, CENTRAL, MEDLINE, Embase and CINAHL databases and World Health Organization International Clinical Trials Registry Platform and ClinicalTrials.gov trials registers to 5 May 2021. We also undertook reference checking to identify additional studies. SELECTION CRITERIA: Randomised and quasi‐randomised trials in which people with an unprovoked VTE were allocated to receive specific tests for identifying cancer or clinically indicated tests only were eligible for inclusion. DATA COLLECTION AND ANALYSIS: Two review authors independently selected studies, assessed risk of bias and extracted data. We assessed the certainty of the evidence using GRADE criteria. We resolved any disagreements by discussion. The main outcomes of interest were all‐cause mortality, cancer‐related mortality and VTE‐related mortality. MAIN RESULTS: No new studies were identified for this 2021 update. In total, four studies with 1644 participants are included. Two studies assessed the effect of extensive tests including computed tomography (CT) scanning versus tests at the physician's discretion, while the other two studies assessed the effect of standard testing plus positron emission tomography (PET)/CT scanning versus standard testing alone. For extensive tests including CT versus tests at the physician's discretion, the certainty of the evidence, as assessed according to GRADE, was low due to risk of bias (early termination of the studies). When comparing standard testing plus PET/CT scanning versus standard testing alone, the certainty of evidence was moderate due to a risk of detection bias. The certainty of the evidence was downgraded further as detection bias was present in one study with a low number of events. When comparing extensive tests including CT versus tests at the physician's discretion, pooled analysis on two studies showed that testing for cancer was consistent with either benefit or no benefit on cancer‐related mortality (odds ratio (OR) 0.49, 95% confidence interval (CI) 0.15 to 1.67; 396 participants; 2 studies; low‐certainty evidence). One study (201 participants) showed that, overall, malignancies were less advanced at diagnosis in extensively tested participants than in participants in the control group. In total, 9/13 participants diagnosed with cancer in the extensively tested group had a T1 or T2 stage malignancy compared to 2/10 participants diagnosed with cancer in the control group (OR 5.00, 95% CI 1.05 to 23.76; low‐certainty evidence). There was no clear difference in detection of advanced stages between extensive tests versus tests at the physician's discretion: one participant in the extensively tested group had stage T3 compared with four participants in the control group (OR 0.25, 95% CI 0.03 to 2.28; low‐certainty evidence). In addition, extensively tested participants were diagnosed earlier than control group (mean: 1 month with extensive tests versus 11.6 months with tests at physician's discretion to cancer diagnosis from the time of diagnosis of VTE). Extensive testing did not increase the frequency of an underlying cancer diagnosis (OR 1.32, 95% CI 0.59 to 2.93; 396 participants; 2 studies; low‐certainty evidence). Neither study measured all‐cause mortality, VTE‐related morbidity and mortality, complications of anticoagulation, adverse effects of cancer tests, participant satisfaction or quality of life. When comparing standard testing plus PET/CT screening versus standard testing alone, standard testing plus PET/CT screening was consistent with either benefit or no benefit on all‐cause mortality (OR 1.22, 95% CI 0.49 to 3.04; 1248 participants; 2 studies; moderate‐certainty evidence), cancer‐related mortality (OR 0.55, 95% CI 0.20 to 1.52; 1248 participants; 2 studies; moderate‐certainty evidence) or VTE‐related morbidity (OR 1.02, 95% CI 0.48 to 2.17; 854 participants; 1 study; moderate‐certainty evidence). Regarding stage of cancer, there was no clear difference for detection of early (OR 1.78, 95% 0.51 to 6.17; 394 participants; 1 study; low‐certainty evidence) or advanced (OR 1.00, 95% CI 0.14 to 7.17; 394 participants; 1 study; low‐certainty evidence) stages of cancer. There was also no clear difference in the frequency of an underlying cancer diagnosis (OR 1.71, 95% CI 0.91 to 3.20; 1248 participants; 2 studies; moderate‐certainty evidence). Time to cancer diagnosis was 4.2 months in the standard testing group and 4.0 months in the standard testing plus PET/CT group (P = 0.88). Neither study measured VTE‐related mortality, complications of anticoagulation, adverse effects of cancer tests, participant satisfaction or quality of life. AUTHORS' CONCLUSIONS: Specific testing for cancer in people with unprovoked VTE may lead to earlier diagnosis of cancer at an earlier stage of the disease. However, there is currently insufficient evidence to draw definitive conclusions concerning the effectiveness of testing for undiagnosed cancer in people with a first episode of unprovoked VTE (DVT or PE) in reducing cancer‐ or VTE‐related morbidity and mortality. The results could be consistent with either benefit or no benefit. Further good‐quality large‐scale randomised controlled trials are required before firm conclusions can be made