A preliminary analysis of convective windstorm environments across Australia

This manuscript documents a preliminary analysis of convective windstorm environments across Australia. It combines radiosonde, reanalysis and severe weather observations to achieve this objective. Severe weather observations across Australia are revealed to have significant issues with stationarity, even when only the past thirty years are considered. Radiosonde and reanalysis observations are shown to agree relatively well for several cities in Australia. In addition, significantly different environments are documented to generate severe wind and tornado events in a sub-tropical environment such as Brisbane compared with a more mid-latitude-like environment such as Perth. The potential to extend this analysis for the remainder of Australia is also briefly discussed.

An objective study of acid reflux and cough in children using an ambulatory pHmetry-cough logger

Objective There are no objective ambulatory studies on the temporal relationship between reflux and cough in children. Commercial pHmetry loggers have slow capture rates (0.25 Hz) that limit objective quantification of reflux and cough. The authors aimed to evaluate if there is a temporal association between cough and acid pH in ambulatory children with chronic cough. setting and patients The authors studied children (aged <14 years) with chronic cough, suspected of acid reflux and considered for pHmetry using a specifically built ambulatory pHmetry–cough logger that enabled the simultaneous ambulatory recording of cough and pH with a fast (10 Hz) capture rate. Main outcome measures Coughs within (before and after) 10, 30, 60 and 120 s of a reflux episode (pH<4 for >0.5 s). Results Analysis of 5628 coughs in 20 children. Most coughs (83.9%) were independent of a reflux event. Cough–reflux (median 19, IQR 3–45) and reflux–cough (24.5, 13–51) sequences were equally likely to occur within 120 s. Within the 10 and 30 s time frame, reflux–cough (10 s=median 2.5, IQR 0–7.25; 30 s=6.5, 1.25–22.25) sequences were significantly less frequent than reflux–no cough (10 s=27, IQR 15–65; 30 s=24.5, 14.5–55.5) sequences, (p=0.0001 and p=0.001, respectively). No differences were found for 60 and 120 s time frame. Cough–reflux sequence (median 1.0, IQR 0–8) within 10 s was significantly less (p=0.0001) than no cough–reflux sequences (median 29.5, 15–67), within 30 s (p=0.006) and 60 s (p=0.048) but not within 120 s (p=0.47). Conclusions In children with chronic cough and suspected of having gastro-oesophageal reflux disease, the temporal relationship between acid reflux and cough is unlikely causal.

Shortages of rural mental health professionals

This study presents a conceptual model of the supply and demand for mental health professionals. It uses national data to profile differences in the supply of mental health professionals in different types of rural and urban areas. It contrasts the availability of general health and mental health professionals. It examines shortage areas identified in 2000 and their related community characteristics. Because of the absence of data on a national level to describe many types of mental health professionals state licensure data for one state were used to show the volume and distribution of these practitioners. To improve rural mental health service delivery it will be necessary to implement system changes to promote the increased availability, competency, and support of rural health professionals. Copyright 2003, Elsevier Science (USA). All rights reserved.

Loading of a very tall building in a simulated downburst wind field

Thunderstorm downbursts are important for wind engineers as they have been shown to produce the design wind speeds for mid to high return periods in many regions of Australia [1]. In structural design codes (e.g. AS/NZS1170.02-02) an atmospheric boundary layer (ABL) is assumed, and a vertical profile is interpolated from recorded 10 m wind speeds. The ABL assumption is however inaccurate when considering the complex structure of a thunderstorm outflow, and its effects on engineered structures. Several researchers have shown that the downburst, close to its point of divergence is better represented by an impinging wall jet profile than the traditional ABL. Physical modelling is the generally accepted approach to estimate wind loads on structures and it is therefore important to physically model the thunderstorm downburst so that its effects on engineered structures may be studied. An advancement on the simple impinging jet theory, addressed here is the addition of a pulsing mechanism to the jet which allows not only the divergent characteristics of a downburst to be produced, but also it allows the associated leading ring vortex to be developed. The ring vortex modelling is considered very important for structural design as it is within the horizontal vortex that the largest velocities occur [2]. This paper discusses the flow field produced by a pulsed wall jet, and also discusses the induced pressures that this type of flow has on a scaled tall building.

Numerical modelling of an imping jet

Impinging flow occurs when a fluid impacts a comparatively solid boundary upon which divergence occurs. A perfect example of an impinging flow is the impact and divergence of air at ground level during a thunderstorm outflow. The importance of modelling thunderstorm outflows, and in particular the downburst is now well-known to the wind engineering community and research into many of its characteristics is underway throughout the world. The reader is directed to the text by Fujita [I] for an introduction to downburst concepts and theory.

Discussion on the wind climate of Kuwait and Dubai

Historical wind data for Kuwait and Dubai have been analysed to determine the design wind speed for the region. Kuwait and Dubai are located near the northern and southern end of the Persian Gulf respectively. The winds in this region just north of the Tropic of Capricorn are dominated by the Shamal, literally 'north' in Arabic. The winds have traditional Bedouin names such as Al-Haffar (the driller), and Barih Thorayya (morning star). The Al-Dabaran is generally the strongest Shamal in late summer, and can last up to 40 days bringing sand and duststorms.

Frontier thinking : fear of the frock?

Stylish women, Dr Gertrude Langer, Margaret Cilento, and Joy Roggenkamp, didn't fit the mythology of modern art in Brisbane, typified by rugged artists like Ian Fairweather and Jon Molvig. Courtney Pedersen considers the place of fashion, urbanity, and women in the mid-century avant-garde.

'Not a Local Win': Rural Australian perceptions of the sustainable impacts of forest plantations

Australian forestry plantations have doubled in the past 15 years, with rural communities harbouring a diverse range of positive and negative of economic, environmental and social impacts – the so-called triple bottom line (TBL). Utilising two Australian rural communities in Eden/Gippsland and Tasmania as qualitative case studies, this research explores how 23 non-forestry affiliated rural residents perceived and experienced the TBL economic, environmental and social impacts of plantation forestry. Residents criticised the economic plantation forestry benefits because of lengthy periods of inactivity and limited local employment, explaining that their community was reliant on the industry yet the promised economic benefits had never fully materialised. There was a sense the industry ‘plant and walk away.’ Residents were concerned about the environment impact on water quality, water tables and fire hazards, although they praised plantation forestry for carbon sequestering, eradicating erosion and water run-off. Negative social impacts were described, specifically how the land-use change from farming to forestry had significantly reduced the local population, employment and need for services. Natural resource management and communication strategies are offered, derived from non-forestry affiliated rural resident perspectives on how best to ensure sustainable forest development in their community.

An iterative speaker re-diarization scheme for improving speaker-based entity extraction in multimedia archives

In this paper we present a novel scheme for improving speaker diarization by making use of repeating speakers across multiple recordings within a large corpus. We call this technique speaker re-diarization and demonstrate that it is possible to reuse the initial speaker-linked diarization outputs to boost diarization accuracy within individual recordings. We first propose and evaluate two novel re-diarization techniques. We demonstrate their complementary characteristics and fuse the two techniques to successfully conduct speaker re-diarization across the SAIVT-BNEWS corpus of Australian broadcast data. This corpus contains recurring speakers in various independent recordings that need to be linked across the dataset. We show that our speaker re-diarization approach can provide a relative improvement of 23% in diarization error rate (DER), over the original diarization results, as well as improve the estimated number of speakers and the cluster purity and coverage metrics.

Recommendations for the categorization of germ cell mutagens

Germ cell mutagens are currently classified into three categories in the German List of MAK- and BAT-Values. These categories have been revised and extended in analogy to the new categories for carcinogenic chemicals. Germ cell mutagens produce heritable gene mutations, and heritable structural and numerical chromosome aberrations in germ cells. The original categories 1 and 2 for germ cell mutagens remained unchanged. Two new categories 3 A and 3 B are proposed for chemicals which are suspected to be germ cell mutagens. A new category 5 is proposed for germ cell mutagens with low potency which contribute negligibly to human genetic risk provided the MAK value is observed. The following categories are presented for further discussion. 1. Germ cell mutagens which have been shown to increase the mutant frequency among the progeny of exposed humans. 2. Germ cell mutagens which have been shown to increase the mutant frequency among the progeny of exposed animals. 3 A. Substances which have been shown to induce genetic damage in germ cells of humans or animals, or which are mutagenic in somatic cells and have been shown to reach the germ cells in their active forms. 3 B. Substances which are suspected of being germ cell mutagens because of their genotoxic effects in mammalian somatic cells in vivo or, in exceptional cases in the absence of in vivo data, if they are clearly mutagenic in vitro and structurally related to in vivo mutagens. 4. not applicable (Category 4 was introduced for carcinogenic substances with nongenotoxic modes of action. By definition, germ cell mutagens are genotoxic. Therefore, a Category 4 for germ cell mutagens cannot exist.) 5. Germ cell mutagens, the potency of which is considered to be so low that, provided the MAK value is observed, their contribution to genetic risk is expected not to be significant.

The cytochrome P-450 isoenzyme CYP2E1 in the biological processing of industrial chemicals : consequences for occupational and environmental medicine

The importance of the isoform CYP2E1 of the human cytochrome P-450 superfamily of enzymes for occupational and environmental medicine is derived from its unique substrate spectrum that includes a number of highly important high-production chemicals, such as aliphatic and aromatic hydrocarbons, solvents and industrial monomers (i.a. alkanes, alkenes, aromatic and halogenated hydrocarbons). Many polymorphic genes, such as CYP2E1, show considerable differences in allelic distribution between different human populations. The polymorphic nature of the human CYP2E1 gene is significant for inter-individual differences in toxicity of its substrates. Since the substrate spectrum of CYP2E1 includes many compounds of basic relevance to industrial toxicology, a rationale for metabolic interactions of different CYP2E1 substrates is provided. In-depth research into the inter-individual phenotypic differences of human CYP2E1 enzyme activities was enabled by the recognition that the 6-hydroxylation of the drug chlorzoxazone is mediated by CYP2E1. Studies on CYP2E1 phenotyping have pointed to inter-individual variations in enzyme activities. There are consistent ethnic differences in CYP2E1 enzyme expression, mostly demonstrated between European and Japanese populations, which point to a major impact of genetic factors. The most frequently studied genetic polymorphisms are the restriction fragment length polymorphisms PstI/RsaI (mutant allele: CYP2E1*5B) located in the 5′-flanking region of the gene, as well as the DraI polymorphism (mutant allele: CYP2E1*6) located in intron 6. These polymorphisms are partly related, as they form the common allele designated CYP2E1*5A. Striking inter-ethnic differences between Europeans and Asians appear with respect to the frequencies of the CYP2E1*5A allele (only approximately 5% of Europeans are heterozygous, but 37% of Asians are, whilst 6% of Asians are homozygous). Available studies indicate a wide variation in human CYP2E1 expression, which are very likely based on complex gene-environment interactions. Major inter-ethnic differences are apparent on the genotyping and the phenotyping levels. Selected cases are presented where inter-ethnic variations of CYP2E1 may provide likely explanations for unexplained findings concerning industrial chemicals that are CYP2E1 substrates. Possible consequences of differential inter-individual and inter-ethnic susceptibilities are related to individual expressions of clinical symptoms of chemical toxicity, to results of biological monitoring of exposed workers, and to the interpretation of results of epidemiological or molecular-epidemiological studies.

Chromosomal genotoxicity of nitrobenzene and benzonitrile

In order to investigate the chromosomal genotoxicity of nitrobenzene and benzonitrile, we studied the induction of micronuclei (MN) by these test compounds in V79 cells, as well as effects on the formation and stability of microtubules and on motor protein functions. No cytotoxicity was seen in V79 cell cultures in terms of Neutral red uptake after 18 h treatment with up to 1 mM nitrobenzene or 1 mM benzonitrile. Subsequently, a concentration range up to 100 μM was used in the experiments on induction of MN. Both test compounds exhibit a weak, but definitely positive test result compared to the solvent (DMSO) control. Minimal effect concentrations of nitrobenzene and benzonitrile appeared as low as 0.01 μM, and no-effect-concentrations were between 0.001 and 0.005 μM. Clearly enhanced MN rates were found at 0.1 μM and higher. Both, nitrobenzene and benzonitrile, induced mostly kinetochor (CREST)-positive micronuclei, thus characterising the chromosomal effects as aneugenic. In cell-free assays, a slight effect on tubulin assembly was observed at 1 mM nitrobenzene without addition of DMSO. Higher concentrations (5 mM) led to secondary effects. In presence of 1% DMSO, nitrobenzene exerted no detectable effect on tubulin assembly up to the solubility limit in water of about 15 mM. For benzonitrile in presence of DMSO, a clear dose-response of inhibition of tubulin assembly at 37°C was seen above the no-effect-concentration of 2 mM, with an IC50 of 13 mM and protein denaturation starting above a level of about 20 mM. The nature of the effects of nitrobenzene and benzonitrile on the association of tubulin to form microtubules was confirmed by electron microscopy. Treatment by either 5 mM nitrobenzene or 13 mM benzonitrile plus 1% DMSO left the microtubular structure intact whereas 5 mM nitrobenzene, in absence of DMSO, led to irregular cluster formations. The experiments demonstrate that both nitrobenzene and benzonitrile, in millimolar concentration ranges, may lead to interference with tubulin assembly in a cell-free system. The functionality of the tubulin-kinesin motor protein system was assessed using the microtubule gliding assay. Nitrobenzene affected the gliding velocity in a concentration-dependent manner, starting at about 7.5 μM and reaching complete inhibition of motility at 30 μM, whereas benzonitrile up to 200 μM did not affect the kinesin-driven gliding velocity. The micronucleus assay data demonstrate a chromosomal endpoint of genotoxicity of nitrobenzene and benzonitrile. Aneugenic effects of both compounds occur at remarkably low concentrations, with lowest-effect-concentrations being 0.1 μM. This points to the relevance of interactions with the cellular spindle apparatus.