589 research outputs found
Methods to select areas to survey for biological control agents: An example based on growth in relation to temperature and distribution of the weed Conyza bonariensis
A novel approach for selecting areas to survey for biological control agents, incorporating climate and a hypothesised biological control agent, is demonstrated using the target weed Conyza bonariensis (Asteraceae). This weed has become important in Australian cropping regions due to its persistence and herbicide resistance, and it is also increasingly an environmental weed. Both are reasons for the investigation of biological control options. We developed a species niche model for C. bonariensis in CLIMEX based on parameters informed by plant growth and distribution of the species in the Americas. A hypothetical biological control agent (HBCA-cold) was proposed that has its ideal growth range 5 °C below that of the weed, so as to favour development of the agent over that of the weed in parts of Australia. The southern part of the weed's native distribution in Argentina, Chile and the highlands of Ecuador and Columbia were identified as the most suitable areas for surveys that take into account both the climate suitable for the HBCA-cold and the target regions in Australia. This was compared to a model (HBCA-hot) that had an ideal growth range 5 °C above that of the weed, but which identified potential areas for surveys in South America that were not climatically aligned with the main regions of the weed's economic impact in Australia. This species distribution modelling method allows for prioritisation of search areas for biological control agents in the case of widespread target species such as C. bonariensis. © 2016 Published by Elsevier Inc
Potential distribution of Rapistrum rugosum (turnip weed)
Rapistrum rugosum (L.) All. (Brassicaceae) is a widely distributed weed of annual crops, especially pulses, in southern Australia. With the south-west of Western Australia predicted to become drier and hotter due to climate change, the development of predictive models to determine future weed threats to the agricultural industry is essential for early intervention and to enable adaptation measures to be put in place. We measured the plant’s growth in relation to temperature and used this information along with soil moisture and phenology information based on the known distribution to derive growth parameters to develop a CLIMEX model. Under a warming climateR. rugosum is projected to increase its distribution in the northern hemisphere, but to decrease its distribution in Australia
Using a systems approach to investigate the efficacy of a disease rating system for Sclerotinia stem rot in canola
Sclerotinia stem rot (SSR), caused by the necrotrophic fungus Sclerotinia sclerotiorum, is a major, but
unpredictable disease of canola in Australia. However, there is no disease rating system for current
canola varieties. Over the last four years the most common varieties of canola grown in Western
Australia were assessed in the field using natural disease occurrence, and in glasshouse experiments
using manual inoculations, to determine their susceptibility to SSR. The results highlighted the
complexity and unpredictable nature of SSR with infection levels and varietal response varying
depending on seasonal conditions and time of infection, despite limited levels of genetic resistance to
SSR in current varieties. It is suggested that a disease rating system should not be based purely on inseason plant infection, but should also include potential for future infections through the contribution
of sclerotia from infected plants to the system
Factors influencing the health behaviour of Indigenous Australians: perspectives from support people
Disparities between the health of Indigenous and non-Indigenous populations continue to be prevalent within Australia. Research suggests that Indigenous people participate in health risk behaviour more often than their non-Indigenous counterparts, and that such behaviour has a substantial impact on health outcomes. Although this would indicate that reducing health risk behaviour may have positive effects on health outcomes, the factors that influence Indigenous health behaviour are still poorly understood. This study aimed to interview people who support Indigenous groups to gain an understanding of their views on the factors influencing health behaviour within Indigenous groups in Western Australia. Twenty nine people participated in the study. The emergent themes were mapped against the social ecological model. The results indicated that: (1) culture, social networks, history, racism, socioeconomic disadvantage, and the psychological distress associated with some of these factors interact to affect health behaviour in a complex manner; (2) the desire to retain cultural identity and distinctiveness may have both positive and negative influence on health risk behaviour; (3) strong social connections to family and kin that is intensified by cultural obligations, appears to affirm and disrupt positive health behaviour; (4) the separation between Indigenous and non-Indigenous social connection/networks that appeared to be fostered by marginalisation and racism may influence the effect of social networks on health behaviour; and (5) communication between Indigenous and non-Indigenous people may be interrupted by distrust between the groups, which reduces the influence of some non-Indigenous sources on the health behaviour of Indigenous people
Recommended from our members
Phase 2 trial of montelukast for prevention of pain in sickle cell disease.
Cysteinyl leukotrienes (CysLTs) are lipid mediators of inflammation. In patients with sickle cell disease (SCD), levels of CysLTs are increased compared with controls and associated with a higher rate of hospitalization for pain. We tested the hypothesis that administration of the CysLT receptor antagonist montelukast would improve SCD-related comorbidities, including pain, in adolescents and adults with SCD. In a phase 2 randomized trial, we administered montelukast or placebo for 8 weeks. The primary outcome measure was a >30% reduction in soluble vascular cell adhesion molecule 1 (sVCAM), a marker of vascular injury. Secondary outcome measures were reduction in daily pain, improvement in pulmonary function, and improvement in microvascular blood flow, as measured by laser Doppler velocimetry. Forty-two participants with SCD were randomized to receive montelukast or placebo for 8 weeks. We found no difference between the montelukast and placebo groups with regard to the levels of sVCAM, reported pain, pulmonary function, or microvascular blood flow. Although montelukast is an effective treatment for asthma, we did not find benefit for SCD-related outcomes. This clinical trial was registered at www.clinicaltrials.gov as #NCT01960413
Attitudes and preferences of home mechanical ventilation users from four European countries: an ERS/ELF survey
Home mechanical ventilation is increasingly used by people with chronic respiratory failure. However, there are few reports on attitudes towards treatment. A web-based survey in eight languages was disseminated across 11 European countries to evaluate the perception of home mechanical ventilation provision in ventilator-assisted individuals and caregivers. Out of 787 responders from 11 European countries, 687 were patients and 100 were caregivers. 95% of patients and 94% of caregivers were from only 4 countries (Germany, the Netherlands, Italy, Spain). The majority of respondents were male and aged 46-65\u2005years. Obstructive lung diseases were proportionally more represented among respondent patients (46%), and neuromuscular diseases (65%) were more represented among patients of respondent caregivers. About 20% of respondent patients and caregivers were not sure of the modality of ventilation. Different interfaces were used, with a minority of respondents in all countries using invasive home mechanical ventilation by tracheostomy. These results may be useful for healthcare providers and policy makers to improve the quality of patients' daily lives
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
(Un)reliable assessment : A case study.
The drive towards quality assurance at South African universities, with 'consistency' of approach being one of its key features, has profound implications for assessment policies and practices in relation to equity. In this article we present a case study discussion of an investigation we undertook, as a department, into certain anomalies which arose in the assessment of a particular group of post-graduate students' research reports. We were puzzled by the variability in the marks awarded by three different markers of the same reports and set out to investigate what factors were producing this 'inter-marker [un]reliability'. Through a content and discourse analysis of the different assessors' written reports, we uncovered the implicit assessment categories and criteria which assessors were working with in their assessments. We discovered shared categories and criteria, as well as differences in how these were weighted. In the interests of equity and increased inter-marker reliability, we have developed a set of banded criteria on generic features of the research report which we intend to develop a set of banded criteria on generic features of the research report which we intend to trial. We also surfaced two unresolved issues: the use of language and the role of the writer's 'voice' in the research report. As a result of this investigation, we argue that the 'consistency' of assessment within and across universities aspired to by quality assurers (such as the HEQC in the South African context) is difficult to achieve and much still depends on professional judgement, intellectual position and personal taste
- …