Biological control of doublegee : Israeli weevil could help fight doublegee

Since its deliberate introduction from South Africa as a salad vegetable in 1830 the doublegee has spread to become a major weed throughout much of Australia. It is one of the most serious weeds of crops and pastures in Western Australia, smothering other more useful plants while young, and troubling both humans and animals with its sharp spiny seeds when mature. Using biological control techniques, scientists are now attacking it and related docks in three ways - with an aphid, a weevil and a fungus. Within a few years it is hoped that while still present, the doublegee will be much less of a problem and more readily controlled by herbicides. Three articles on the following pages outline the latest rounds in the ongoing campaign against doublegee

ACUTE PSYCHOSOCIAL STRESS DOES NOT INCREASE DYSFUNCTIONAL ATTITUDES

Introduction: Dysfunctional attitudes about oneself, the world and the future, measured quantitatively by Weissman’s Dysfunctional Attitudes Scale (DAS), are thought to influence the onset and persistence of major depressive disorder. However, never-depressed individuals may also harbour latent negative schema which may become activated under stressful conditions, giving rise to dysfunctional negative cognitions. Objectives: This study investigated whether everyday psychosocial stresses could be sufficient to activate dysfunctional selfschema and increase negative cognitions in a large group of healthy adolescents and a preliminary cohort of previously depressed adolescents. Methods: 92 never-depressed adolescents aged 17-19 and 18 previously depressed adolescents, recruited from the Cambridge ROOTS cohort, took either version A or B of the DAS at rest on day 1. On day 2, they were subjected to the Trier Social Stress Test, a psychosocial stress paradigm, 22 minutes after which they took the other version of DAS. Results: Stress did not affect the DAS score in either group. Conclusions: Brief psychosocial stress does not appear to influence negative assumptions in healthy young adults with or without a past history of depression. It is possible that this is because dysfunctional assumptions, unlike self-schemas, are not latent. More long-term stresses may be needed to activate negative thoughts to a level where risk of depression is increased

Potential Distribution of the Australian Native Chloris truncata Based on Modelling Both the Successful and Failed Global Introductions

Our aim was to model the current and future potential global distribution of Chloris truncata (windmill grass) based on the plant’s biology, soil requirements and colonisation success. The growth response of C. truncata to constant temperatures and soil moisture levels were measured and estimated respectively, to develop parameters for a CLIMEX bioclimatic model of potential distribution. The native distribution in eastern Australia and naturalised distribution in Western Australia was also used to inform the model. Associations with soil types were assessed within the suitable bioclimatic region in Australia. The global projection of the model was tested against the distribution of soil types and the known successful and failed global introductions. The verified model was then projected to future conditions due to climate change. Optimal temperature for plant development was 28°C and the plant required 970 degree-days above a threshold of 10°C. Early collection records indicate that the species is native to Queensland, New South Wales and Victoria. The plant has been introduced elsewhere in Australia and throughout the world as a wool contaminant and as a potential pasture species, but some of the recorded establishments have failed to persist. The CLIMEX model projected to the world reflected effectively both the successful and failed distributions. The inclusion of soil associations improved the explanation of the observed distribution in Australia, but did not improve the ability to determine the potential distribution elsewhere, due to lack of similarity of soil types between continents. The addition of a climate change projection showed decreased suitability for this species in Australia, but increased suitability for other parts of the world, including regions where the plant previously failed to establish

Preliminary Findings of the High Quantity of Microplastics in Faeces of Hong Kong Residents

Microplastics are recognised as a ubiquitous and hazardous pollutant worldwide. These small-sized particles have been detected in human faeces collected from a number of cities, providing evidence of human ingestion of microplastics and their presence in the gastrointestinal tract. Here, using Raman spectroscopy, we identified an average of 50 particles g−1 (20.4–138.9 particles g−1 wet weight) in faeces collected from a healthy cohort in Hong Kong. This quantity was about five times higher than the values reported in other places in Asia and Europe. Polystyrene was the most abundant polymer type found in the faeces, followed by polypropylene and polyethylene. These particles were primarily fragments, but about two-thirds of the detected polyethylene terephthalate were fibres. More than 88% of the microplastics were smaller than 300 µm in size. Our study provides the first data on the faecal level, and thus the extent of ingestion, of microplastics in Hong Kong’s population. This timely assessment is crucial and supports the recently estimated ingestion rate of microplastics by Hong Kong residents through seafood consumption, which is one of the highest worldwide. These findings may be applicable to other coastal populations in South China with similar eating habits

Alignment of Carbon Nanotube Additives for Improved Performance of Magnesium Diboride Superconductors

The rapid progress on MgB2 superconductor since its discovery[1] has made this material a strong competitor to low and high temperature superconductors (HTS) for applications with a great potential to catch the niche market such as in magnetic resonant imaging (MRI). Thanks to the lack of weak links and the two-gap superconductivity of MgB2 [2,3] a number of additives have been successfully used to enhance the critical current density, Jc and the upper critical field, Hc2.[4-12] Carbon nanotubes (CNTs) have unusually electrical, mechanical and thermal properties[13-16] and hence is an ideal component to fabricate composites for improving their performance. To take advantages of the extraordinary properties of CNTs it is important to align CNTs in the composites. Here we report a method of alignment of CNTs in the CNT/MgB2 superconductor composite wires through a readily scalable drawing technique. The aligned CNT doped MgB2 wires show an enhancement in magnetic Jc(H) by more than an order of magnitude in high magnetic fields, compared to the undoped ones. The CNTs have also significantly enhanced the heat transfer and dissipation. CNTs have been used mainly in structural materials, but here the advantage of their use in functional composites is shown and this has wider ramifications for other functional materials.Comment: 11 pages, 3 figures. to be published in Advanced Material

Magnetic field processing to enhance critical current densities of MgB2 superconductors

A magnetic field of up to 12T was applied during the sintering process of pure MgB2 and carbon nanotube(CNT)dopedMgB2wires. The authors have demonstrated that magnetic field processing results in grain refinement, homogeneity, and enhancement in Jc(H) and Hirr. The extent of improvement in Jc increases with increasing field. The Jc for a 10T field processed CNTdoped sample increases by a factor of 3 at 10K and 8T and at 20K and 5T, respectively. Hirr for the 10T field processed CNTdoped sample reached 9T at 20K, which exceeded the best value of SiC dopedMgB2 at 20K. Magnetic field processing reduces the resistivity in CNTdopedMgB2, straightens the entangled CNTs, and improves the adherence between CNTs and the MgB2 matrix

Challenges to evidence-informed decision-making in the context of pandemics: qualitative study of COVID-19 policy advisor perspectives

INTRODUCTION: The exceptional production of research evidence during the COVID-19 pandemic required deployment of scientists to act in advisory roles to aid policy-makers in making evidence-informed decisions. The unprecedented breadth, scale and duration of the pandemic provides an opportunity to understand how science advisors experience and mitigate challenges associated with insufficient, evolving and/or conflicting evidence to inform public health decision-making. OBJECTIVES: To explore critically the challenges for advising evidence-informed decision-making (EIDM) in pandemic contexts, particularly around non-pharmaceutical control measures, from the perspective of experts advising policy-makers during COVID-19 globally. METHODS: We conducted in-depth qualitative interviews with 27 scientific experts and advisors who are/were engaged in COVID-19 EIDM representing four WHO regions and 11 countries (Australia, Canada, Colombia, Denmark, Ghana, Hong Kong, Nigeria, Sweden, Uganda, UK, USA) from December 2020 to May 2021. Participants informed decision-making at various and multiple levels of governance, including local/city (n=3), state/provincial (n=8), federal or national (n=20), regional or international (n=3) and university-level advising (n=3). Following each interview, we conducted member checks with participants and thematically analysed interview data using NVivo for Mac software. RESULTS: Findings from this study indicate multiple overarching challenges to pandemic EIDM specific to interpretation and translation of evidence, including the speed and influx of new, evolving, and conflicting evidence; concerns about scientific integrity and misinterpretation of evidence; the limited capacity to assess and produce evidence, and adapting evidence from other contexts; multiple forms of evidence and perspectives needed for EIDM; the need to make decisions quickly and under conditions of uncertainty; and a lack of transparency in how decisions are made and applied. CONCLUSIONS: Findings suggest the urgent need for global EIDM guidance that countries can adapt for in-country decisions as well as coordinated global response to future pandemics