Distribution of logs in a dry sclerophyll forest, Brisbane Ranges, Victoria

Fallen timber is an important habitat resource for small vertebrate and invertebrate animals in forests. This exploratory study investigated the pattern of distribution of fallen timber (here termed 'logs') in a dry sclerophyll forest in the Brisbane Ranges, Victoria, by sampling transects located in
gully, mid-slope and ridge positions, at each of 10 sites. Gullies supported a significantly higher density and volume of logs than ridges. The lowest abundance of logs was on ridges. The mean volume of logs was 98.6 m3/ha for gullies, 38.5 m3/ha at mid-slope positions and 13.1 m3/ha for ridges. The
volume of logs at transects was significantly positively correlated with the density of larger trees (diameter >40 em). A number of animal species in the Brisbane Ranges potentially use logs as a resource for shelter, foraging or perching, and hence the retention ofwoody debris will aid in habitat
management. The uneven distribution of logs in relation to forest topography and the size strueture of trees suggests that gullies, and forest stands with many large trees, are likely to be important habitats for species that use fallen timber. (The Victorian Naturalist 120 (2), 2003, 55-60)

Contribution of fungi to primary biogenic aerosols in the atmosphere: wet and dry discharged spores, carbohydrates, and inorganic ions

Biogenic aerosols play important roles in atmospheric chemistry physics, the biosphere, climate, and public health. Here, we show that fungi which actively discharge their spores with liquids into the air, in particular actively wet spore discharging Ascomycota (AAM) and actively wet spore discharging Basidiomycota (ABM), are a major source of primary biogenic aerosol particles and components. We present the first estimates for the global average emission rates of fungal spores.

Measurement results and budget calculations based on investigations in Amazonia (Balbina, Brazil, July 2001) indicate that the spores of AAM and ABM may account for a large proportion of coarse particulate matter in tropical rainforest regions during the wet season (0.7–2.3 μg m⁻³). For the particle diameter range of 1–10 μm, the estimated proportions are ~25% during day-time, ~45% at night, and ~35% on average. For the sugar alcohol mannitol, the budget calculations indicate that it is suitable for use as a molecular tracer for actively wet discharged basidiospores (ABS). ABM emissions seem to account for most of the atmospheric abundance of mannitol (10–68 ng m⁻³), and can explain the observed diurnal cycle (higher abundance at night). ABM emissions of hexose carbohydrates might also account for a significant proportion of glucose and fructose in air particulate matter (7–49 ng m⁻³), but the literature-derived ratios are not consistent with the observed diurnal cycle (lower abundance at night). AAM emissions appear to account for a large proportion of potassium in air particulate matter over tropical rainforest regions during the wet season (17–43 ng m⁻³), and they can also explain the observed diurnal cycle (higher abundance at night). The results of our investigations and budget calculations for tropical rainforest aerosols are consistent with measurements performed at other locations.

Based on the average abundance of mannitol reported for extratropical continental boundary layer air (~25 ng m⁻³), we have also calculated a value of ~17 Tg yr⁻¹ as a first estimate for the global average emission rate of ABS over land surfaces, which is consistent with the typically observed concentrations of ABS (~10³–10⁴ m⁻³; ~0.1^–1 μg m⁻³). The global average atmospheric abundance and emission rate of total fungal spores, including wet and dry discharged species, are estimated to be higher by a factor of about three, i.e. 1 μg m⁻³ and ~50 Tg yr⁻¹. Comparisons with estimated rates of emission and formation of other major types of organic aerosol (~47 Tg yr⁻¹ of anthropogenic primary organic aerosol; 12–70 Tg yr⁻¹ of secondary organic aerosol) indicate that emissions from fungi should be taken into account as a significant global source of organic aerosol. The effects of fungal spores and related chemical components might be particularly important in tropical regions, where both physicochemical processes in the atmosphere and biological activity at the Earth's surface are particularly intense, and where the abundance of fungal spores and related chemical compounds are typically higher than in extratropical regions.

Influence of chromium content on the dry machining performance of cathodic arc evaporated TiA1N coatings

Physical vapour deposition (PVD) titanium aluminium nitride coated cutting tools are used extensively in global manufacturing for reducing production costs and improving productivity in a number of aggressive metal-cutting operations, namely, dry and high-speed machining. In this investigation, the performance of Ti1−xAlxN and Ti1−x−yAlxCryN coatings was assessed on Co-HSS twist drills used to machine grey cast iron. The failure criterion for drills was defined as a critical sized flank wear land at the outer corners of the drills. Using this criterion, the average tool life of uncoated twist drills was increased by factors of 2.5, 3.0 and 3.0 by Ti0.59Al0.41N, Ti0.27Al0.19Cr0.54N and Ti0.21Al0.14Cr0.65N coatings, respectively. Notwithstanding the similar increase in average tool life, the Ti1−x−yAlxCryN coatings produced more consistent results than the Ti1−xAlxN coated drills with standard deviations of 67, 3 and 19 holes, respectively. This result has significant practical implications in manufacturing, since drills are not replaced on an individual basis, but rather on a preset tool change frequency. The present paper discusses the performance of Ti1−xAlxN and Ti1−x−yAlxCryN coated drills in terms of average and practical drill life and concludes with remarks on the characterisation of PVD coatings and their significance on the performance of Co-HSS twist drills when dry machining grey cast iron.

Dry your eyes princess : an analysis of gender and 'other' based discources in police organisations

This paper examines the literature relevant to an analysis of gender and discourse in police organisations with a view to testing it through research. Much of the literature on policing can be divided into four key topic areas: the features and construction of police culture; women’s integration into policing; organisational structures and styles of police leadership; and debates about the nature of police work. An examination of the literature has revealed a deficiency of research in discourses within policing and in particular, the impact of discourses on gender and police training. Assumptions underpinning the research project and supported by literature include: formal and informal structures and practices within organisations produce and reproduce gender relations; power, gender relations and masculinity are characteristics of police culture; discourses are products and resources of interactions which establish particular truths; and police organisations have been slow to respond to anti-discrimination legislation and to integrate women into police services. Critical to any analysis of culture, power, gender, discourses, difference, and subjectification is the dynamic and complex nature of culture. Applying Shearing’s and Ericson’s definition of culture as ‘figurative logic’ has resonance in police organisations where symbols, rhetoric and metaphors function as vehicles for discourses.

Ecosystem services of tropical dry forests : insights from longterm ecological and social research on the Pacific coast of Mexico

In the search for an integrated understanding of the relationships among productive activities, human well-being, and ecosystem functioning, we evaluated the services delivered by a tropical dry forest (TDF) ecosystem in the Chamela Region, on the Pacific Coast of Mexico. We synthesized information gathered for the past two decades as part of a long-term ecosystem research study and included social data collected in the past four years using the Millennium Ecosystem Assessment (MA) conceptual framework as a guide. Here we identify the four nested spatial scales at which information has been obtained and emphasize one of them through a basin conceptual model. We then articulate the biophysical and socio-economic constraints and drivers determining the delivery of ecosystem services in the Region. We describe the nine most important services, the stakeholders who benefit from those services, and their degree of awareness of such services. We characterize spatial and temporal patterns of the services’ delivery as well as trade-offs among services and stakeholders. Finally, we contrast three alternative future scenarios on the delivery of ecosystem services and human well-being. Biophysical and socioeconomic features of the study site strongly influence human−ecosystem interactions, the ecosystem services delivered, the possible future trajectories of the ecosystem, and the effect on human well-being. We discuss future research approaches that will set the basis for an integrated understanding of human−ecosystem interactions and for constructing sustainable management strategies for the TDF.

House price bubble estimations in Australia's capital cities with market fundamentals

This paper investigates the existence of house price bubbles in Australia's eight capital cities in recent years by using quantitative analyses including Johansen cointegration test, Granger causality test, impulse response and Chow forecast test. While interactions between house prices and market fundamentals are discussed in long-run and causal estimations, shocks from the market fundamentals to house prices are investigated in generalized impulse response analyses. Findings from estimating house price bubbles for eight capital cities suggest that there was an obvious house price bubble in Perth, while a slight house price bubble occurred in Sydney. In contrast, house prices in Adelaide and Darwin can be explained very well by market fundamentals, while house prices in Melbourne, Brisbane, Hobart and Canberra were undervalued in the study period.

Bubble-solid interactions in water and electrolyte solutions

Surface forces between an air bubble and a flat mica surface immersed in aqueous electrolyte solutions have been investigated using a modified surface force apparatus. An analysis of the deformation of the air bubble with respect to the mutual position of the bubble and the mica surface, the capillary pressure, and the disjoining pressure allows the air-liquid surface electrical potential to be determined. The experiments show that a long-range, double-layer repulsion acts between the mica (which is negatively charged) and an air bubble in water and in various electrolyte solutions at low concentration, thereby indicating that the air bubble surface is negatively charged. However, there is clear evidence that charge regulation occurs at the air-water interface to maintain a constant surface potential, and as a result of this, the charge at this interface changes from negative to positive as the bubble approaches the mica surface. Because of the attraction that arises as a result of the charge reversal, a finite force is required to separate the bubble from the mica, though the mica remains wetted by the aqueous phase. At the low concentrations investigated, the potential on the gas-liquid interface is independent of the electrolyte type within experimental uncertainty.