Growth temperature influences postharvest glucosinolate concentrations and hydrolysis product formation in first and second cuts of rocket salad

Rocket salad species (Diplotaxis tenuifolia and Eruca sativa; also known as E. vesicaria) are known for their high concentrations of health-related isothiocyanates, which are derived from secondary metabolites called glucosinolates. Increases in temperature due to climate change and extreme weather event frequencies over the coming decades are likely to influence not only the growth of leafy vegetables, but also their nutritional density. It is therefore essential to determine the impacts of these in order to mitigate crop losses and nutritional decline in future. Our data show there is a strong influence of pre-harvest growth temperatures on glucosinolate biosynthesis and formation of glucosinolate hydrolysis products postharvest, and that this is genotype dependent. High growth temperature (40 °C) severely retarded germination, growth, regrowth, and survival of rocket plants. Highest glucosinolate concentrations were observed in first and second cuts at 40 °C, but did not correspond to highest isothiocyanate concentrations (observed at 30 °C, second cut). Hydrolysis product formation is proportionately not as great as glucosinolate increases at 40 °C, possibly due to inhibition of enzyme function(s) at higher temperatures. These data indicate that high growth temperatures increase glucosinolate accumulation, but growth and productivity is significantly reduced. Much greater emphasis is needed for breeding cultivars tolerant to high growth temperatures in order to maximise nutritional benefits imparted by temperature stress

A comparison of daily consumption of artificial dye-containing foods by american children and adults

Children with developing nervous systems might be at greater risk for any potential neurobehavioral effects of color additives widespread in many foods. This study thus examined whether children consumed foods containing color additives more frequently than adults. Twenty-one adults (aged 18-60) and parents of 14 children (aged 4-7) with regular eating patterns kept detailed food records for five days. Diets were analyzed for foods containing the dyes Red #3, Red #40, Yellow #5, Yellow #6, Blue #1, Blue #2 and Green #3 by comparing ingredient labels found in grocery stores and online. The number of daily dye exposures was significantly (P\u3c0.001) greater for children (2.43 ± 0.35 exposures) than for adults (0.76 ± 0.15 exposures). Fruit and vegetable consumption was inversely correlated (- 0.63) to the number of dye exposures per day in children but not in adults (0.18). Children habitually consume more brightly colored foods with additives in lieu of nutrient dense foods

Variability, oxidation resistance and wear of 'medical grade' ultra-high molecular weight polyethylene

The aim of this project was to examine factors affecting wear mechanisms in total knee replacement (TKR). The hypothesis of this work was that manufacturing, processing and sterilisation techniques for 'medical grade' ultra-high molecular weight polyethylene (UHMWPE) would result in a variability in material properties, oxidation resistance and wear performance. Examination of stock materials and retrievals showed there were differences in grain structure, extent of consolidation and resistance to oxidation. A novel staining technique was developed which Fourier Transform Infrared spectroscopy showed corresponded to regions of oxidation. Examination of retrieved TKRs and wear test specimens showed that the development of a sub-surface oxidised band (due to post irradiation damage) was related to delamination wear. It was also found that surface oxidation of UHMWPE was caused by articulation with the femoral component. The development of an artificial ageing regime allowed the effect of oxidation on the material and wear properties of polyethylene to be investigated. This showed that a critical level of oxidation was required before delamination occurred. Oxidation levels associated with five to ten years of shelf-ageing resulted in a reduction in fatigue life of two orders of magnitude and an increase in crack propagation rates by 10-400 times (depending on manufacturing method). Oxidation also resulted in a reduction in UTS, and brittle fracture of test specimens. Investigation of a modified polyethylene showed that annealing UHMWPE after irradiation resulted in a three times reduction in the wear rate compared to untreated polyethylene. Annealing also produced a reduction in the level of oxidation induced using artificial ageing and a wear rate which was ten times lower than standard UHMWPE. However this modified material was not totally resistant to oxidation. Many reports of excellent wear properties and long-term survivorship rates for directly moulded polyethylene components have been published and in my study this material was found to have a greater oxidation resistance than other materials, as well as lower wear rates. In a ten million cycle simulator test, artificial ageing of directly moulded polyethylene resulted in no significant increase in wear rate when compared with unaged material. Delamination wear did not occur in either shelf-aged or artificially aged directly moulded components, whereas delamination did occur in oxidised non- directly moulded components. My study demonstrated differences in 'medical grade' polyethylene manufactured by different techniques. This affected the resistance of UHMWPE to oxidation and to wear

What for the future, from learning the past? Exploring the implications of the compulsory Aotearoa New Zealand histories curriculum

Important curriculum development work has progressed since the 2019 announcement that Aotearoa New Zealand histories would become compulsory learning across all schools. Much effort has gone into considering how learning ‘our’ histories can engage, inspire and empower children in schools through years 1 to 10, and recent writing has focused on how to address challenges in building knowledge and capability to meet those aims. However, what will be the effects beyond those years? Will students still be drawn to choose history in their senior school years, or will they be ‘over it’? In a quest to gauge the implications of the new curriculum, our research team surveyed secondary school history students on their motivations and areas of interest in learning history, and their views on Aotearoa New Zealand history becoming compulsory for Years 1-10. Findings from our research confirmed that students’ past engagement with history influenced their ongoing interest, motivation and understanding of the subject. However, the positive learning that had drawn them to history was often about everyone else’s history rather than their own. Students identified international histories – often involving war or conflict – as favourite topics. So, while most supported the implementation of the new curriculum, they equally expressed concern that the local focus should not be at the expense of wider perspectives. They felt history could become repetitive and boring; elements which could put students off engaging with history in future.  We conclude by presenting important considerations for ensuring such negative impacts do not occur

The distribution, larval survival, and impact of a tip moth guild (Lepidoptera: Tortricidae: Rhyacionia specia) in the Northern Plains

A guild of three and possibly five tip moths (Rhyacionia spp.) occurs on ponderosa pine (Pinus ponderosa) in southeastern Montana, northwestern South Dakota, and southwestern North Dakota. Trapping results indicated that many of these species may be flying simultaneously, and individual species relative abundances showed west-to-east trends. Tip moth larvae became increasingly concentrated in the tops of trees as the summer progressed. A significant percentage of larvae in infested shoots were parasitized or died before pupating. Parasitism rate was higher in larvae collected later in the growing season. Tip moth larval survival rate was affected by larval location within the tree and the date of collection. Seedlings and saplings studied had fewer branches on average than ponderosa pines in other regions. The percent of apical shoots infested per tree (API) was strongly correlated with the total percent of shoots infested per tree (PI) as long as API was less than 50%. Neither API nor PI was strongly correlated with total linear shoot growth (linear growth). Linear growth was affected by tree deformity and available site moisture. Wetter sites also had higher mean PI. Aspect, slope, regenerating tree density, horizontal configuration, topography, and habitat types were examined for effects on tip moth activity. Impact measures such as API and PI were not strongly affected by these characteristics. PI appeared to be higher in areas that retain moisture, i.e. concave or horizontal land form, than in areas that do not, i.e. convex or slope land form. Abundant precipitation may mask this relationship. Management implications are discussed