Search

Restrictions on movement during the COVID-19 pandemic led to assessment being conducted online, which gave students opportunities to use internet search engines during examinations. We found that in some cases internet searches resulted in characteristic incorrect responses, and around one third of students entered these answers to examination questions in a foundation chemistry unit. Classification of those students allowed us to analyse their performance on other assessment tasks and we found that students who used an internet search and input incorrect results performed worse across all assessment tasks. Use of online proctoring and an academic honesty module in subsequent semesters reduced the percentage of students entering incorrect answers found though internet searches. We explored the relationship between students' prior knowledge, investment in content and self-efficacy with the use of internet searches during their examination. We found significant correlations with prior knowledge and investment, but not with self-efficacy. Our data calls for better authentication of online assessment, because in most cases internet searches give correct responses and so it is impossible to be sure that a student has generated the response. We propose guidelines to reduce the use of search engines during examinations.

Rapid campus closure and unexpected transition to emergency online teaching of a large first year chemistry unit provided an opportunity to explore the level of student engagement and factors associated with success in this online transition. Here, we compared the standard offering in 2019 to the online version in 2020 by examining the completion of weekly assessment tasks and the uptake of learning activities. In spite of a preference for face-to-face learning, we found that students were able to quickly adapt to using the technology, with high levels of access to live streamed and recorded lectures, in-class polling, and online tutorials, together with large increases in discussion forum use. The change in level of engagement in low stakes assessment tasks over the course of the semester was similar for both years. Each form of engagement was associated with increased likelihood of success in the unit, whether this was being taught face-to-face or online. Of the multiple forms of engagement measured, only tutorial participation had a significantly lower impact on student success in the online compared to the face-to-face environment.

The closure of campuses in early 2020 due to the COVID-19 pandemic meant that scheduled practical activities for introductory chemistry students could not take place. The first practical class started prior to shutdown, and 21.5% of the students undertook the face-to-face offering. The remainder completed an online offering consisting of the same worksheet with videos of each of the tasks, which relate to ions in solution: conductivity and precipitation. A Kruskal-Wallis rank sum test comparison of the marks for the first practical showed that online students had, on average, a 0.9/10 drop in their mark compared to the face-to-face cohort. We concluded that a significant proportion of students found the transition to online learning difficult with the technology we provided. Rather than add another online learning activity, we chose to develop simple activities that students could complete at home, along with worksheets linking their observations to the theory taught in class. The first kitchen chemistry activity included experimental measurement (timing water boiling), solubility (mixing water with salt, sugar or oil), heat capacity (heating salt, sugar, butter and water), combustion calculations for gas heating, and colligative properties (timing ice melting with and without added salt). The second kitchen chemistry activity involved adding a constant amount of sodium bicarbonate to differing amounts of vinegar to explore stoichiometry; relating this to gas law calculations, and an extraction of red cabbage or other colored food to investigate the pH of household items. The aims of the kitchen chemistry experiments were to develop student observation skills, emphasize the importance of measurement and significant figures and provide some simple hands-on and relevant activities that could be done safely at home. The proportion of students who submitted online chemistry practicals was the same as typically attends face-to-face practicals (90%). Preliminary evaluation through anonymous student comments and staff reflections suggests that this was a valuable exercise: most students were able to learn in this replacement hands-on environment, receiving mean scores of 7.5/10 or higher. We conclude that relevant, engaging kitchen chemistry activities are useful for foundation level chemistry students.

Ocular allergy (OA) is characterised by ocular surface itchiness, redness, and inflammation in response to allergen exposure. The primary aim of this study was to assess differences in the human tear metabolome and lipidome between OA and healthy controls (HCs) across peak allergy (spring–summer) and off-peak (autumn–winter) seasons in Victoria, Australia. A total of 19 participants (14 OA, 5 HCs) aged 18–45 were recruited and grouped by allergy questionnaire score. Metabolites and lipids from tear samples were analysed using mass spectrometry. Data were analysed using TraceFinder and Metaboanalyst. Metabolomics analysis showed 12 differentially expressed (DE) metabolites between those with OA and the HCs during the peak allergy season, and 24 DE metabolites were found in the off-peak season. The expression of niacinamide was upregulated in OA sufferers vs. HCs across both seasons (p ≤ 0.05). A total of 6 DE lipids were DE between those with OA and the HCs during the peak season, and 24 were DE in the off-peak season. Dysregulated metabolites affected oxidative stress, inflammation, and homeostasis across seasons, suggesting a link between OA-associated itch and ocular surface damage via eye rubbing. Tear lipidome changes were minimal between but suggested tear film destabilisation and thinning. Such metabolipodome findings may pave new and exciting ways for effective diagnostics and therapeutics for OA sufferers in the future. [ABSTRACT FROM AUTHOR]

Seaweed extracts are a prominent class of biostimulants that enhance plant health and tolerance to biotic and abiotic stresses due to their unique bioactive components. However, the mechanisms of action of biostimulants are still unknown. Here, we have used a metabolomic approach, a UHPLC-MS method, to uncover the mechanisms induced following application to Arabidopsis thaliana of a seaweed extract derived from Durvillaea potatorum and Ascophyllum nodosum. We have identified, following the application of the extract, key metabolites and systemic responses in roots and leaves across 3 timepoints (0, 3, 5 days). Significant alterations in metabolite accumulation or reduction were found for those belonging to broad groups of compounds such as lipids, amino acids, and phytohormones; and secondary metabolites such as phenylpropanoids, glucosinolates, and organic acids. Strong accumulations of TCA cycle and N-containing and defensive metabolites such as glucosinolates were also found revealing the enhancement of carbon and nitrogen metabolism and defence systems. Our study has demonstrated that application of seaweed extract dramatically altered the metabolomic profiles of Arabidopsis and revealed differences in roots and leaves that varied across the timepoints tested. We also show clear evidence of systemic responses that were initiated in the roots and resulted in metabolic alterations in the leaves. Collectively, our results suggest that this seaweed extract promotes plant growth and activates defence systems by altering various physiological processes at the individual metabolite level. [ABSTRACT FROM AUTHOR]

Nanomaterials such as copper nanoparticles have attracted significant attention because of their interesting size- and shape-dependent properties. However, their increased instability remains a challenge. This study therefore focuses on the growth of copper/copper oxide nanocrystals within nanofiber scaffolds, achieved by thermal reduction of poly-(vinyl alcohol) nanofibers cross-linked with copper-(II) acetate. A reduction temperature of up to 800 °C in 15% H2 balanced in N2 was found to lead to the formation of copper-based nanofibers (CuNFs) of sub-250-nm diameter that presented a core–sheath morphology, resulting from copper efflorescence. Enrobing a hydrolysis-resistant polymer core, the sheath layer was found to be composed of a discrete distribution of polymer-embedded crystalline nanospheres with diameters below 20 nm and of round crystallites of up to 65 nm protruding at the surface of CuNFs. With a significant proportion in copper intermediary states, this heterogeneous material is promising for various applications benefiting from the surface reactivity and versatile efficiency from the simultaneous presence of a transition metal and transition-metal oxide. For instance, with a material dose of 0.20 g·L–1 and an initial arsenic-(V) concentration of 120 mg·L–1, CuNFs yielded up to 96.5% arsenic-(V) removal. This route for the manufacture of copper hybrid nanofibers can be adapted to other transition metals and blends. [ABSTRACT FROM AUTHOR]

SUMMARY: Conventional breeding efforts for iron (Fe) and zinc (Zn) biofortification of bread wheat (Triticum aestivum L.) have been hindered by a lack of genetic variation for these traits and a negative correlation between grain Fe and Zn concentrations and yield. We have employed genetic engineering to constitutively express (CE) the rice (Oryza sativa) nicotianamine synthase 2 (OsNAS2) gene and upregulate biosynthesis of two metal chelators – nicotianamine (NA) and 2′‐deoxymugineic acid (DMA) – in bread wheat, resulting in increased Fe and Zn concentrations in wholemeal and white flour. Here we describe multi‐location confined field trial (CFT) evaluation of a low‐copy transgenic CE‐OsNAS2 wheat event (CE‐1) over 3 years and demonstrate higher concentrations of NA, DMA, Fe, and Zn in CE‐1 wholemeal flour, white flour, and white bread and higher Fe bioavailability in CE‐1 white flour relative to a null segregant (NS) control. Multi‐environment models of agronomic and grain nutrition traits revealed a negative correlation between grain yield and grain Fe, Zn, and total protein concentrations, yet no correlation between grain yield and grain NA and DMA concentrations. White flour Fe bioavailability was positively correlated with white flour NA concentration, suggesting that NA‐chelated Fe should be targeted in wheat Fe biofortification efforts. Significance Statement: Nicotianamine (NA) and 2′‐deoxymugineic acid (DMA) are important chelators of iron (Fe) and zinc (Zn) in graminaceous plants. Field evaluation of biofortified wheat (Triticum aestivum) containing higher concentrations of NA, DMA, Fe, and Zn in wholemeal flour, white flour, and white bread demonstrated that grain NA and DMA concentrations do not correlate with yield and highlighted NA‐chelated Fe as a promising target for wheat biofortification programs. [ABSTRACT FROM AUTHOR]

The one-electron reduction of [alpha(sub 2)-Fe(OH(sub 2))P(sub 2)W(sub 17)O(sub 61)](super 7-) at a glassy carbon electrode was investigated using cyclic and rotating-disk-electrode voltammetry in buffered and unbuffered aqueous solutions over the pH range 3.45-7.50 with an ionic strength of approximately 0.6 M maintained. Analysis of the simulations illustrates the contribution of the buffer in terms of general acid-base catalysis, a pathway not available in unbuffered media.