Description:
Understanding all potential slope failure mechanisms is a pre-requisite for predicting the likelihood of batter movements during excavation in open cut mines. The tensile behavior of soils and rocks may be a significant contributor to a slope failure and must be known in order to quantify the risks of slope failure. The contribution can be particularly significant for Intermediate Geotechnical Materials (IGMs) that possess characteristics of both soils and rocks and where the failure mechanisms are complex due to the interplay between ductile and brittle behavior. Brown coal is such an intermediate Geotechnical Material. Recent batter movements in the brown coal mines in the Latrobe Valley, Australia have raised doubts about the current understanding of the mechanisms of slope failure in this material. Research is underway to re-evaluate all properties of the brown coal applicable to slope failure. This paper describes the investigation of brown coal tensile strength. There are alternative test methods available to determine the tensile behavior of materials, including direct tensile tests, beam bending tests and Brazilian compression tests. The applicability of each test method is material dependent, as such, it is necessary to confirm the validity of the methods for each material. Beam bending tests have achieved mixed results for both rocks and IGMs previously. Thus, the present work has explored only the use of Direct tensile and Brazilian test methods. Both methods were implemented using a modified direct shear apparatus and valid test procedures for both test methods were developed. Each test procedure has been verified by Finite Element Modelling (FEM) using ABAQUS 6.12.1 FEM code. The results from the laboratory test methods are in good agreement and show that brown coal is a predominantly brittle material with a peak tensile strength slightly greater than 100 kPa. The finite element analyses confirm that non-uniformity of the tensile stresses during sample loading tends to lead to the underestimation of tensile strength for both tests, but the Brazilian test has less bias for brown coal. It is observed that the rate of loading of low stiffness, low permeability, and saturated samples in the Brazilian test is an important test design parameter for the accurate determination of tensile strength of IGMs in the laboratory.
Description:
The taxonomic status of the subgenera of Lepidocyrtus Bourlet is confused. Currently ten subgenera are recognised but their separation, using the existing set of diagnostic characters, is not clear. Collections over the last forty years have shown that species of Setogaster Salmon, originally described as a genus (Trichogaster Handschin) and currently considered a subgenus of Lepidocyrtus, are common and widespread in Australia. The diagnostic characters of Setogaster, as given by Handschin, are: 1) the basal mucronal spine with spinelet; 2) lack of scales on antennae, legs, ventral tube and dorsal region of manubrium; and, for some species, 3) tufts of long filaments laterally on abdomen III. These three diagnostic characters for Setogaster are shared with some other subgenera, making their delimitation unclear. We provide here an array of new characters that are associated with Handschin's characters which separate Setogaster from all European species of the subgenera Lanocyrtus and Lepidocyrtus s. str. On this basis we define subgenus Setogaster more in detail, redescribe some species in the subgenus, corroborate the presence of the subgenus in many Australian localities, and confirm three records of exotic, introduced species in Australia. Lepidocyrtus nigrofasciatus Womersley, Lepidocyrtus praecisus Schott, and the Hawaiian Lepidocyrtus kuakea Christiansen & Bellinger, are placed in Setogaster subgenus; Lepidocyrtus (Trichogaster) pallida Salmon from Singapore is placed in the subgenus Acrocyrtus; Merapicyrtus Yoshii & Suhardjono is considered a synonym of Setogaster.
Description:
INTRODUCTION: Organophosphates are a class of insecticides used globally by the agricultural industry for insect control. Acute consequences of organophosphate exposures are well known, while there has been limited research on their long-term effects. The objective of this review was to discuss the health effects of chronic organophosphate exposure in farmers. METHODS: Medline, Scopus and Web of Science were searched to find the relevant articles. Articles published only in English and until December 2018 were reviewed. The selected articles were then categorised as neurological (neurobehaviour, neurodevelopmental, neurological signs and symptoms) or non-neurological subheadings. RESULTS: A total of 53 articles for neurological effects and 17 articles for non-neurological effects were identified. Chronic organophosphates exposure was associated with deficits in the neurobehaviour subsets of attention and short-term memory, increased incidence of neurodegenerative diseases and effects on peripheral nerves and neurodevelopment. However, research to support non-neurological effects such as respiratory symptoms, increased cancer risk, endocrine disruption, cardiac issues, chronic fatigue and infertility was limited. CONCLUSION: Chronic organophosphate exposure was found to affect four of the five areas of described neurological effects in the literature. A large proportion of the research in this area was not methodologically strong, therefore few recommendations can be conclusively made. Future research is warranted to investigate the non-neurological effects of chronic exposure to ensure the occupational risks of low-level chronic exposure are clearly communicated to farmers and farm workers.
Description:
INTRODUCTION: Organophosphates are a class of insecticides used globally by the agricultural industry for insect control. Acute consequences of organophosphate exposures are well known, while there has been limited research on their long-term effects. The objective of this review was to discuss the health effects of chronic organophosphate exposure in farmers. METHODS: Medline, Scopus and Web of Science were searched to find the relevant articles. Articles published only in English and until December 2018 were reviewed. The selected articles were then categorised as neurological (neurobehaviour, neurodevelopmental, neurological signs and symptoms) or non-neurological subheadings. RESULTS: A total of 53 articles for neurological effects and 17 articles for non-neurological effects were identified. Chronic organophosphates exposure was associated with deficits in the neurobehaviour subsets of attention and short-term memory, increased incidence of neurodegenerative diseases and effects on peripheral nerves and neurodevelopment. However, research to support non-neurological effects such as respiratory symptoms, increased cancer risk, endocrine disruption, cardiac issues, chronic fatigue and infertility was limited. CONCLUSION: Chronic organophosphate exposure was found to affect four of the five areas of described neurological effects in the literature. A large proportion of the research in this area was not methodologically strong, therefore few recommendations can be conclusively made. Future research is warranted to investigate the non-neurological effects of chronic exposure to ensure the occupational risks of low-level chronic exposure are clearly communicated to farmers and farm workers.
Description:
INTRODUCTION: National and state-based minimum data sets remain inadequate in providing a complete representation of emergency presentations, especially among paediatric asthma presentations. Thus, the aim of the study was to identify if a deficit exists in current emergency paediatric asthma hospital presentation datasets and how this may inform an understanding of childhood asthma in Victoria Methods: This retrospective cross-sectional study examined emergency hospital presentation data between 1 February 2017 and 31 January 2019. All paediatric (0-14 years) emergency asthma presentation data were collected from nine hospitals in south-western Victoria, Australia, using the Rural Acute Hospital Data Register (RAHDaR), which gathers both Victorian Emergency Minimum Dataset (VEMD) data from larger government hospitals, and non-VEMD data from smaller, more rural institutions. RESULTS: Of the 854 emergency presentations identified for children with asthma aged 0-14 years, 540 (63.2%) were managed initially at larger government-reporting hospitals. A total of 314 (36.8%) emergency presentations were initially managed at emergency facilities, such as urgent care centres. Overall, it was found that a total 278 (32.5%) of all emergency presentations did not appear in current government datasets. CONCLUSION: The RAHDaR database, a complete register of data, captures all emergency presentations in south-western Victoria and highlights as much as a 33% deficit in the data currently available to inform asthma resource initiatives including policy development, funding allocation, prevention and management initiatives in Victoria. More accurate data from sources such as RAHDaR are essential to fill the now-evident data chasm.
Description:
INTRODUCTION: National and state-based minimum data sets remain inadequate in providing a complete representation of emergency presentations, especially among paediatric asthma presentations. Thus, the aim of the study was to identify if a deficit exists in current emergency paediatric asthma hospital presentation datasets and how this may inform an understanding of childhood asthma in Victoria Methods: This retrospective cross-sectional study examined emergency hospital presentation data between 1 February 2017 and 31 January 2019. All paediatric (0-14 years) emergency asthma presentation data were collected from nine hospitals in south-western Victoria, Australia, using the Rural Acute Hospital Data Register (RAHDaR), which gathers both Victorian Emergency Minimum Dataset (VEMD) data from larger government hospitals, and non-VEMD data from smaller, more rural institutions. RESULTS: Of the 854 emergency presentations identified for children with asthma aged 0-14 years, 540 (63.2%) were managed initially at larger government-reporting hospitals. A total of 314 (36.8%) emergency presentations were initially managed at emergency facilities, such as urgent care centres. Overall, it was found that a total 278 (32.5%) of all emergency presentations did not appear in current government datasets. CONCLUSION: The RAHDaR database, a complete register of data, captures all emergency presentations in south-western Victoria and highlights as much as a 33% deficit in the data currently available to inform asthma resource initiatives including policy development, funding allocation, prevention and management initiatives in Victoria. More accurate data from sources such as RAHDaR are essential to fill the now-evident data chasm.
Delineating genetic management units of sambar deer (Rusa unicolor) in south-eastern Australia, using opportunistic tissue sampling and targeted scat collection
Description:
Country-specific information on risk management is increasingly important, not only for investors and decision makers in international markets but also, for those in national and regional markets. This study reports the results of a cross-sectional survey of risk management practice and derivatives use by a sample of Australian firms. Overall, the results suggest that firm-specific factors appear to have some influence on risk management practice with the industry of the respondent being the most important, while the degree of international exposure has the least. Larger and more internationally exposed firms are likely to have more frequent reporting of derivatives use, and are more likely to use swaps and options to manage risks than other types of firms. Issues and implications for international firms are discussed