Mapping eucalypt forest susceptible to dieback associated with bell miners (Manorina melanophys) using laser scanning, SPOT 5 and ancillary topographical data

Mapping the location and extent of forest at risk from damaging agents or processes assists forest managers in prioritizing their planning and operational mitigation activities. In Australia, Bell Miner Associated Dieback (BMAD) refers to a form of canopy decline observed in eucalypt crowns occupied by colonies of bell miners (Manorina melanophrys). High densities of bell miners are associated with decreased avian abundance and diversity and an increase in psyllid abundance on crown foliage. BMAD has recently been nominated as a key threatening process in New South Wales (NSW). Consequently, a modelling system for predicting bell miner distribution in coastal eucalypt forests of NSW has been developed. The presence or absence of bell miners was recorded in 130 plots located within a 12,800 ha catchment study area containing a range of eucalypt forest types. The modelling system was produced by integrating a machine learning software suite (WEKA), and the statistical software R within the geographic resources analysis support system (GRASS) geographical information system (GIS). The variable modelled was the binary variable: presence or absence of bell minors. Six modelling techniques (Logistic regression; generalised additive models; two tree-based ensemble classification algorithms, random forest and Adaboost and Neural Networks) were integrated with airborne laser scanning; SPOT 5 and topographic derived variables. Model evaluation and parameter selection were measured by three threshold dependent measures (sensitivity, specificity and kappa) and the threshold independent Receiver Operator Curve (ROC) analysis. The final presence and absence maps were obtained through maximisation of the kappa statistic and applied at a resolution of 10 m across the entire catchment study area. For this data set, the most accurate algorithm for predicting the distribution of bell miner colonies was random forest (kappa = 0.84; ROC area under curve = 0.97). Variables most commonly selected in the six models were the laser scanning metrics; coefficient of variation, skewness, and the 10th and 90th percentiles derived from the shape of the height frequency distribution which, in turn, is directly influenced by vertical structure of the forest. An image textural statistic based on the shortwave infrared (SWIR) band of SPOT 5 was also commonly selected by the models. The SWIR band is sensitive to vegetation and soil moisture content. These models predicted that forest stands with a sparse eucalypt canopy over a moist, dense understorey were susceptible to being colonised by bell miners and hence BMAD.     

Efficient thinning regimes for Eucalyptus fastigata: Multi-objective stand-level optimisation using the island model genetic algorithm

A stand-level optimisation problem formulated to determine a set of efficient thinning regimes satisfying two objectives, i.e. value production for sawlog harvesting and volume production for a pulpwood market, was demonstrated for a Eucalyptus fastigata trial in Kaingaroa Forest, New Zealand. Genetic algorithms were used to estimate the set of efficient thinning regimes (i.e. regimes that occur when it is not possible to increase the achievement of one objective without reducing another) known as a Pareto frontier. Each thinning regime specified a unique combination of initial planting density; frequency, timing and intensity of thinning; final crop number; and rotation length. Specifications for the “best” regime in the Pareto set (i.e. the one that satisfied a balanced trade-off between value and volume production) were similar to those recommended through professional judgment based on pooled long-term field observations from different eucalypt species grown throughout New Zealand. The advantage of Pareto optimality was the ability of not only identifying a unique thinning regime, but equally efficient regimes each providing a different combination of value and volume production. Research on this approach has the potential of being applied to other forest sites, providing there is sufficient re-measurement data to reflect stand growth dynamics.     

What does it mean to transform knowledge into action in falls prevention research? Perspectives from the Canadian Institutes of Health Research

Introduction

The concept of knowledge translation as defined by the Canadian Institutes for Health Research and the Knowledge to Action Cycle, described by Graham et al (Graham et al., 2006), are used to make a case for the importance of using a conceptual model to describe moving knowledge into action in the area of falls prevention.

Method

There is a large body of research in the area of falls prevention. It would seem that in many areas it is clear what is needed to prevent falls and further syntheses can determine where the evidence is sufficiently robust to warrant its implementation as well as where the gaps are that require further basic research.

Conclusion

The phases of the action cycle highlight seven areas that should be paid attention to in order to maximize chances of successful implementation.     

Perceptions of personal vulnerability to workplace hazards in the Australian construction industry

Introduction

The importance of risk perception for workplace safety has been highlighted by the inclusion of risk appraisals in contemporary models of precautionary behavior at work. Optimism bias is the tendency to think that negative events are less likely to happen to oneself than to the average person, and is proposed to be related to the reduced use of precautions.

Method

Building on studies of optimism bias for workplace hazards using samples with heterogenous risk profiles, the current study aimed to investigate whether optimism bias is present in a sample of workers exposed to similar workplace hazards. 175 Australian construction workers completed a brief survey that asked them to rate the likelihood of common construction industry hazards occurring to them and to the average worker of the same age doing the same job. Significant levels of optimism bias were found for many hazards (including being electrocuted, being trapped in a confined space, falling from heights, and causing someone else to have an injury).

Results

Optimism bias was not related to perceived controllability, contrary to findings in other domains, yet consistent with findings of optimism bias for workplace hazards. Optimism bias was not found to be related to a reduction in safe work behaviors, though this may be due to difficulties in measuring safe or precautionary behavior, such as social desirability.

Impact on industry

That most workers think that hazards are less likely to happen to them than to the average worker presents a significant problem because it may ameliorate the efficacy of safety programs, yet constitutes a largely unexplored opportunity for improving workplace safety performance.     

The contribution of dry deposited ammonia and sulphur dioxide to the composition of precipitation from continuously open gauges

A series of experiments using bulk precipitation collectors of the type used in the UK precipitation chemistry network measured the amounts of NH₄⁺, SO₄²⁻ and other ions that could be washed from funnels (diameter 15 cm) exposed to a wide range of NH₃ and SO₂ concentrations over periods from hours to days. In dry conditions, the average deposition flux of NH₃ was between 50 and 120 nmol NH₄⁺ funnel⁻¹ d⁻¹ (0.1–0.3 kg N ha⁻¹ yr⁻¹), and was independent of the concentration of NH₃. Dry deposition of NH₃ to wet funnels at small NH₃ concentrations was almost 5 times that to dry funnels under the same conditions (average 240 nmol funnel⁻¹ d⁻¹; 0.7 kg ha⁻¹ yr⁻¹), and increased with increasing NH₃ concentrations. The amount of NH₄⁺ ions remaining on the funnel surface was inversely proportional to the vapour pressure deficit during the experiment. This result was interpreted as a dependence on the duration of surface wetness, with greater deposition of NH₄⁺ when evaporation rates of surface water were small.The amount of SO₂ deposited on funnel surfaces was closely related to the amount of NH₃ deposited, in both wet and dry conditions, but was not strongly correlated with the SO₂ concentration. At low NH₃ and SO₂ concentrations the average deposition to dry funnels was 70 nmol SO₄²⁻ funnel⁻¹ d⁻¹ (0.5 kg ha⁻¹ yr⁻¹), and to wet funnels was approximately 2.5 times larger. The results are interpreted in terms of the balance between the rate of evaporation of surface water, and the rate of oxidation of SO₂, which leads to the ‘fixing’ of NH₄⁺ ions on the surface as involatile salts.It is predicted that dry deposition of NH₃ to funnel surfaces across the UK Secondary Network could account for as much as one-half of the measured bulk wet deposition at sites where wet deposition of NH₄–N is small. The amount of dry deposition depends on how long and how often funnel surfaces are wetted by rain or dew, and on the air concentrations of NH₃. These predictions are based on funnels being wetted only once per day. More frequent wetting would increase the contribution from dry deposition, and the consequent overestimate of wet deposition of NH₄–N across the UK by using data obtained from bulk collectors. To some extent this overestimate may be offset by microbial degradation and loss of NH₄–N in weekly bulk precipitation samples during collection and storage.     

Interactions between Sediment and Water: Perspectives on the 10th International Association for Sediment Water Science Symposium

The 10^th International Symposium on Interactions Between Sediment and Water was held in Lake Bled, Slovenia from August 28 to September 3, 2005. Approximately 155 delegates, attended the symposium where talks and posters addressed five themes incorporating the physical, chemical, biological, and/or management aspects of lacustrine, reverine, estuarine, and/or marine sediment were presented. A review of the symposium themes and plenary talks was provided. As well, this symposiums’ focus is put into context with respect to historical changes noted over the 29 years that the International Association for Sediment Water Science (IASWS) has been meeting.     

Using a mathematical model to test the null hypothesis of optimal shell construction by four marine gastropods

A previous analysis (Heath 1985; Biol J Linn Soc 24: 165–174) tested and rejected the null hypothesis that gastropods construct their shells with optimal efficiency. The ratio volume of material used to volume of space enclosed (V _shell:V _space) was used as a measure of inefficiency of construction and shown to exhibit smooth parabolic curves if plotted as a function of whorl overlap. In the present analysis, in contrast, it is demonstrated that inefficiency of a particular combination of mode and rate of shell construction, consisting of variable interapertural areas and rapidly expanding whorl cross sections, is described by polynomial curves with inflection points. As an empirical test of this theoretically derived observation, V _shell:V _space of shells of four species of marine gastropods [Architectonica perspectiva (L., 1758), Cittarium pica (L., 1758), Euspira heros (Say, 1822), and Telescopium telescopium (L., 1758)] was calculated, using a mathematical model. By varying the vertical component of aperture trajectories [i.e. translation (T )] in the mathematical model, hypothetical forms representing a range of possible whorl overlap were simulated graphically and, for each form, V _shell:V _space was calculated. Plots of V _shell:V _space as a function of whorl overlap were described accurately by polynomial curves with inflection points, and each real shell yielded a nonoptimal V _shell:V _space, exhibiting approximately 75% less whorl overlap than its most efficiently constructed, hypothetical form. Inflection points of inefficiency curves represent critical points at which the reduction of space provided begins to exceed significantly the amount of material saved with increasing whorl overlap, and nonoptimal shell forms might represent compromises between efficient construction and function. Received: 26 June 1998 / Accepted: 17 March 1999     

Counselling following a diagnosis of congenital heart disease

Counselling the parents following a diagnosis of fetal congenital heart disease (CHD) is as important a task for the fetal cardiologist, as the skill involved in achieving an accurate diagnosis. The counsellor will base prognosis not only on the diagnosis itself but also on the security of diagnosis, the stage in gestation and potential for change, the association with extracardiac malformations and the known results of treatment. Depending on the gestational age and legal situation the counsellor is operating in, termination of pregnancy may be one of the options to consider and one that should always be raised in discussion. Thus, the parents may be in the position of making a crucial decision concerning the management of the pregnancy on the basis of the information received, so it is vital that the counsellor is truly able to communicate with them, whatever be their level of understanding. Copyright © 2004 John Wiley & Sons, Ltd.     

Tradable permits without legislative targets: a review of the potential for a permit scheme for sterilized clinical waste in the UK.

Tradable-permit schemes are becoming an increasingly popular technique for encouraging materials recovery and the diversion of waste from landfill. Such schemes operate using various forms of market-based trading of waste permits between polluters but usually rely on mandatory recycling targets to provide an incentive for trading. Using the UK's Packaging Recovery Note (PRN) scheme as a template, this paper examines the potential for permit trading where mandatory targets are absent and schemes must be driven solely by the financial benefits of reduced landfill costs and permit/material sales. The case examined is sterilized clinical waste, which has considerable recycling potential but suffers from health concerns and a poor public image. Interviews with healthcare and waste-management representatives indicate that although elements of the PRN scheme might prove appropriate for encouraging materials recovery, the absence of government targets and uncertain end markets for sterilized clinical waste present major obstacles to trading. Alternative incentives would therefore be required to catalyse schemes and develop recycling infrastructure. In the final analysis, thermal processing may be a more practical alternative to landfill than materials recovery for this particular waste stream.     

The Axford Debate Revisited: A Case Study Illustrating Different Approaches to the Aggregation of Benefits Data

Recent debate following the rejection of the Environment Agency case regarding an application for water abstraction at Axford on the River Kennet has focused upon the benefits procedure employed for aggregating non-user benefits which underpinned the economic case put forward by the Agency (although this was not the reason cited by the inquiry for rejection of the case). Commentators have seen this case as setting an unfortunate precedent for the use of economic assessments in such resource management issues. The paper presents a number of highly tractable alternative methods for the aggregation of benefits estimates designed to address the central problems of the definition of a relevant aggregation population and a potential decay of values with increasing distance from a given valuation site. These methods are tested using data obtained from a national survey of non-users of a specific natural area. Results from this application indicate that simpler approaches such as that used at the Axford inquiry may result in aggregate benefits estimates which are very substantially larger than those produced by our proposed alternative approaches to aggregation.