Estimating local stream fish assemblage attributes: Sampling effort and efficiency at two spatial scales

As part of a wider study to develop an ecosystem-health monitoring program for wadeable streams of south-eastern Queensland, Australia, comparisons were made regarding the accuracy, precision and relative efficiency of single-pass backpack electrofishing and multiple-pass electrofishing plus supplementary seine netting to quantify fish assemblage attributes at two spatial scales (within discrete mesohabitat units and within stream reaches consisting of multiple mesohabitat units). The results demonstrate that multiple-pass electrofishing plus seine netting provide more accurate and precise estimates of fish species richness, assemblage composition and species relative abundances in comparison to single-pass electrofishing alone, and that intensive sampling of three mesohabitat units (equivalent to a riffle-run-pool sequence) is a more efficient sampling strategy to estimate reach-scale assemblage attributes than less intensive sampling over larger spatial scales. This intensive sampling protocol was sufficiently sensitive that relatively small differences in assemblage attributes (<20%) could be detected with a high statistical power (1-β > 0.95) and that relatively few stream reaches (<4) need be sampled to accurately estimate assemblage attributes close to the true population means. The merits and potential drawbacks of the intensive sampling strategy are discussed, and it is deemed to be suitable for a range of monitoring and bioassessment objectives.

Catchment-specific element signatures in estuarine crocodiles (Crocodylus porosus) from the Alligator Rivers Region, northern Australia

The concentrations of Na, K, Ca, Mg, Ba, Sr, Fe, Al, Mn, Zn, Pb, Cu, Ni, Cr, Co, Se, U and Ti were determined in the osteoderms and/or flesh of estuarine crocodiles (Crocodylus porosus) captured in three adjacent catchments within the Alligator Rivers Region (ARR) of northern Australia. Results from multivariate analysis of variance showed that when all metals were considered simultaneously, catchment effects were significant (P≤0.05). Despite considerable within-catchment variability, linear discriminant analysis (LDA) showed that differences in elemental signatures in the osteoderms and/or flesh of C. porosus amongst the catchments were sufficient to classify individuals accurately to their catchment of occurrence. Using cross-validation, the accuracy of classifying a crocodile to its catchment of occurrence was 76% for osteoderms and 60% for flesh. These data suggest that osteoderms provide better predictive accuracy than flesh for discriminating crocodiles amongst catchments. There was no advantage in combining the osteoderm and flesh results to increase the accuracy of classification (i.e. 67%). Based on the discriminant function coefficients for the osteoderm data, Ca, Co, Mg and U were the most important elements for discriminating amongst the three catchments. For flesh data, Ca, K, Mg, Na, Ni and Pb were the most important metals for discriminating amongst the catchments. Reasons for differences in the elemental signatures of crocodiles between catchments are generally not interpretable, due to limited data on surface water and sediment chemistry of the catchments or chemical composition of dietary items of C. porosus. From a wildlife management perspective, the provenance or source catchment(s) of 'problem' crocodiles captured at settlements or recreational areas along the ARR coastline may be established using catchment-specific elemental signatures. If the incidence of problem crocodiles can be reduced in settled or recreational areas by effective management at their source, then public safety concerns about these predators may be moderated, as well as the cost of their capture and removal. Copyright © 2002 Elsevier Science B.V.

The effect of preferential sampling on sampling variance

We examine some variations of standard probability designs that preferentially sample sites based on how easy they are to access. Preferential sampling designs deliver unbiased estimates of mean and sampling variance and will ease the burden of data collection but at what cost to our design efficiency? Preferential sampling has the potential to either increase or decrease sampling variance depending on the application. We carry out a simulation study to gauge what effect it will have when sampling Soil Organic Carbon (SOC) values in a large agricultural region in south-eastern Australia. Preferential sampling in this region can reduce the distance to travel by up to 16%. Our study is based on a dataset of predicted SOC values produced from a datamining exercise. We consider three designs and two ways to determine ease of access. The overall conclusion is that sampling performance deteriorates as the strength of preferential sampling increases, due to the fact the regions of high SOC are harder to access. So our designs are inadvertently targeting regions of low SOC value. The good news, however, is that Generalised Random Tessellation Stratification (GRTS) sampling designs are not as badly affected as others and GRTS remains an efficient design compared to competitors.

Caveats - Limited extensions effectively unlimited

The decision of Young J in McCosker v Lovitt (1995) 12 BCL 146 paces an interpretation upon s 74J of the Real Property Act 1900 (NSW) likely to surprise the unwary respondent to proceedings in New South Wales involving an application for an order to extend a caveat. Further, the similarity in critical respects between s74J and the legislation relating to lapse and extension of caveats in some jurisdictions when contrasted with other lapse provisions suggests that a court order extending a caveat for a specified period only may have very different consequences in different jurisdictions.

Universal codes from switching strategies

We discuss algorithms for combining sequential prediction strategies, a task which can be viewed as a natural generalisation of the concept of universal coding. We describe a graphical language based on Hidden Markov Models for defining prediction strategies, and we provide both existing and new models as examples. The models include efficient, parameterless models for switching between the input strategies over time, including a model for the case where switches tend to occur in clusters, and finally a new model for the scenario where the prediction strategies have a known relationship, and where jumps are typically between strongly related ones. This last model is relevant for coding time series data where parameter drift is expected. As theoretical contributions we introduce an interpolation construction that is useful in the development and analysis of new algorithms, and we establish a new sophisticated lemma for analysing the individual sequence regret of parameterised models.

Parents' reported use and views of strategies for managing the behaviour of their preschool child

The aim of the research was two-fold: firstly, to investigate strategies used by Australian parents to encourage desirable child behaviours and to decrease undesirable behaviours; secondly, to determine the acceptability and perceived usefulness to parents of various strategies. The research encompassed two studies. In the first study, 152 parents of children aged under six years completed questionnaires to identify their disciplinary practices. In Study 2, 129 parents reported on the acceptability and perceived effectiveness of various parenting strategies (modelling, ignoring, rewarding and physical punishment) for influencing child behaviour. Most parents in Study 1 reported using techniques consistent with positive parenting strategies. The use of physical punishment was also reported, but predominantly as a secondary method of discipline. In Study 2, the techniques of modelling and rewarding were found to be more acceptable to parents than were ignoring and smacking. The findings highlight the need to raise parental awareness and acceptance of a broader range of positive ways to manage child behaviour.

Restructuring arts and cultural funding in Tanzania : expectations and impasses

In 1984, the Tanzanian government established the Tanzania Culture Trust Fund (TCTF) – well known as ‘Mfuko’ – with the support of the Swedish government. The focus of Mfuko was to enable the arts and cultural sector to strengthen its position through grant allocations. However, rural artists have limited opportunity to access financial support to strengthen their works. The challenge remains: how to restructure arts and cultural funding in line with cutting dependence on foreign aid. This article reports on the research findings of a case study based on ‘Strategies for youth employment in Tanzania: A creative industries approach’. The study was undertaken in Dar-Es-Salaam, Bagamoyo, Dodoma, Lindi and Morogoro from July to October, 2012. This study employed mixed me thods incorporating questionnaires, interviews, and focus groups. This paper argues that lack of deliberate initiatives to restructure arts and cultural funding (in line with cutting dependence on foreign assistance) have prevented artists from fulfilling their desire for better lives. Hence, the severe lack of financial support to the artists remains a challenge to meeting the Millennium Development Goals and Tanzania Development Vision 2025. Although this discussion is specific to Tanzania, the significance and contribution of this case may apply to other developing countries.

Independent learning skills, self-determination theory and psychological well-being : strategies for supporting the first year university experience

The purpose of this article is to explain why the first year in higher education experience of Australian tertiary students can be improved through the explicit teaching of independent learning skills. Becoming an independent learner has many benefits, but the focus of this piece is upon the connection between independent learning and the improvement of student psychological well-being. High psychological distress levels appear to start in the first year of university education. We argue that explicitly teaching students independent learning skills is an important curriculum-based strategy that will contribute to the significant task of addressing this issue.

Observations on the formation, growth and chemical composition of aerosols in an urban environment

The charge and chemical composition of ambient particles in an urban environment were determined using a Neutral Particle and Air Ion Spectrometer and an Aerodyne compact Time-Of-Flight Aerosol Mass Spectrometer. Particle formation and growth events were observed on 20 of the 36 days of sampling, with eight of these events classified as strong. During these events, peaks in the concentration of intermediate and large ions were followed by peaks in the concentration of ammonium and sulphate, which were not observed in the organic fraction. Comparison of days with and without particle formation events revealed that ammonium and sulphate were the dominant species on particle formation days while high concentrations of biomass burning OA inhibited particle growth. Analyses of the degree of particle neutralisation lead us to conclude that an excess of ammonium enabled particle formation and growth. In addition, the large ion concentration increased sharply during particle growth, suggesting that during nucleation the neutral gaseous species ammonia and sulphuric acid react to form ammonium and sulphate ions. Overall, we conclude that the mechanism of particle formation and growth involved ammonia and sulphuric acid, with limited input from organics.

Mathematical modeling of the cancer cell’s control circuitry : paving the way to individualized therapeutic strategies

Cancer is a disease of signal transduction in which the dysregulation of the network of intracellular and extracellular signaling cascades is sufficient to thwart the cells finely-tuned biochemical control mechanisms. A keen interest in the mathematical modeling of cell signaling networks and the regulation of signal transduction has emerged in recent years, and has produced a glimmer of insight into the sophisticated feedback control and network regulation operating within cells. In this review, we present an overview of published theoretical studies on the control aspects of signal transduction, emphasizing the role and importance of mechanisms such as ‘ultrasensitivity’ and feedback loops. We emphasize that these exquisite and often subtle control strategies represent the key to orchestrating ‘simple’ signaling behaviors within the complex intracellular network, while regulating the trade-off between sensitivity and robustness to internal and external perturbations. Through a consideration of these apparent paradoxes, we explore how the basic homeostasis of the intracellular signaling network, in the face of carcinogenesis, can lead to neoplastic progression rather than cell death. A simple mathematical model is presented, furnishing a vivid illustration of how ‘control-oriented’ models of the deranged signaling networks in cancer cells may enucleate improved treatment strategies, including patient-tailored combination therapies, with the potential for reduced toxicity and more robust and potent antitumor activity.

The SEA-CALIPSO volcano imaging experiment at Montserrat : plans, campaigns at sea and on land, scientific results, and lessons learned

Since 1995 the eruption of the andesitic Soufrière Hills Volcano (SHV), Montserrat, has been studied in substantial detail. As an important contribution to this effort, the Seismic Experiment with Airgunsource-Caribbean Andesitic Lava Island Precision Seismo-geodetic Observatory (SEA-CALIPSO) experiment was devised to image the arc crust underlying Montserrat, and, if possible, the magma system at SHV using tomography and reflection seismology. Field operations were carried out in October–December 2007, with deployment of 238 seismometers on land supplementing seven volcano observatory stations, and with an array of 10 ocean-bottom seismometers deployed offshore. The RRS James Cook on NERC cruise JC19 towed a tuned airgun array plus a digital 48-channel streamer on encircling and radial tracks for 77 h about Montserrat during December 2007, firing 4414 airgun shots and yielding about 47 Gb of data. The main objecctives of the experiment were achieved. Preliminary analyses of these data published in 2010 generated images of heterogeneous high-velocity bodies representing the cores of volcanoes and subjacent intrusions, and shallow areas of low velocity on the flanks of the island that reflect volcaniclastic deposits and hydrothermal alteration. The resolution of this preliminary work did not extend beyond 5 km depth. An improved three-dimensional (3D) seismic velocity model was then obtained by inversion of 181 665 first-arrival travel times from a more-complete sampling of the dataset, yielding clear images to 7.5 km depth of a low-velocity volume that was interpreted as the magma chamber which feeds the current eruption, with an estimated volume 13 km3. Coupled thermal and seismic modelling revealed properties of the partly crystallized magma. Seismic reflection analyses aimed at imaging structures under southern Montserrat had limited success, and suggest subhorizontal layering interpreted as sills at a depth of between 6 and 19 km. Seismic reflection profiles collected offshore reveal deep fans of volcaniclastic debris and fault offsets, leading to new tectonic interpretations. This chapter presents the project goals and planning concepts, describes in detail the campaigns at sea and on land, summarizes the major results, and identifies the key lessons learned.

Decision strategies for automated visual collision avoidance

This paper provides a preliminary analysis of an autonomous uncooperative collision avoidance strategy for unmanned aircraft using image-based visual control. Assuming target detection, the approach consists of three parts. First, a novel decision strategy is used to determine appropriate reference image features to track for safe avoidance. This is achieved by considering the current rules of the air (regulations), the properties of spiral motion and the expected visual tracking errors. Second, a spherical visual predictive control (VPC) scheme is used to guide the aircraft along a safe spiral-like trajectory about the object. Lastly, a stopping decision based on thresholding a cost function is used to determine when to stop the avoidance behaviour. The approach does not require estimation of range or time to collision, and instead relies on tuning two mutually exclusive decision thresholds to ensure satisfactory performance.

Cultural development strategies and urban revitalization

Municipal governments around the globe increasingly turn to museums, performing arts centers, arts districts, and other cultural activities to promote and revitalize their cities. While a significant body of literature examines revitalization strategies that focus primarily around entertainment and commerce, the empirical body of research that specifically investigates the role of cultural strategies in urban redevelopment is still growing. This paper first discusses the development of municipal cultural strategies in the United States, and draws from the literature to outline the characteristics of three different models of such strategies. Second, the paper presents findings from a national survey distributed to municipal agencies involved in the promotion and development of cultural activities and facilities in large and medium‐sized US cities. The survey data indicate that although most agencies are guided by a varied set of goals, entrepreneurial objectives continue to guide the development and support of cultural activities in most cities.

Strategic entry deterrence : does it constitute a misuse of market power?

A challenge for regulators and the courts has been establishing the boundary between behaviour is exclusionary and should be condemned under s 46 of the then Trade Practices Act 1974 (Cth) (TPA), now s 46 of the Competition and Consumer Act 2010 (Cth) (CCA), and behaviour that is not exclusionary and might even be pro-competitive. This boundary can be especially difficult to draw in the case of entry deterring strategies. Section 46(1) prohibits corporations with a substantial degree of market power from taking advantage of that market power for one of the statutorily proscribed purposes which include preventing the entry of a person into that or any other market. Section 45(2) separately prohibits corporations from making and giving effect to contracts arrangements and understandings that have the purpose, effect or likely effect of substantially lessening competition in a market. The latest case in which the ACCC has failed to satisfy the s 46 criteria is the decision of Greenwood J in ACCC v Cement Australia Pty Ltd [2013] FCA 909 (Cement Australia case). Final orders were published in a separate judgment, in ACCC v Cement Australia Pty Ltd [2014] FCA 148 (28 February 2014). The case concerned an entry deterring strategy, namely the pre-emptive buying of input factors in an upstream market to protect an incumbent with substantial market power in a downstream market and to prevent new entry in the downstream market. Greenwood J found that while Cement Australia Pty Ltd, formerly known as Queensland Cement Ltd (QCL), had substantial market power, its conduct in entering into the pre-emptive contracts was not a contravention of s 46, because Cement Australia had not “taken advantage” of its market power. However, since Cement Australia’s purpose in entering into the pre-emptive contracts was anti-competitive, they were held to contravene s 45(2) of the TPA. The purpose of this Note is to consider only the reasons for judgment in the Cement Australia case in relation to the “taking advantage” element. The judgment was handed down on 10 September 2013. The final hearing date was 15 July 2011, so it was long-awaited. At 714 pages, it is carefully drafted.

A review of the profile of endothelin axis in cancer and its management

The endothelins and their associated receptors are important controllers of vascular growth, inflammation and vascular tone. In cancer, they have roles in the control of numerous factors in cancer development and progression, including angiogenesis, stromal reaction, epithelial mesenchymal transitions, apoptosis, invasion, metastases and drug resistance. Also, we consider current information on the role of this signalling system in cancer and examine the state of the current cell, animal and clinical trials utilizing endothelin targeted drugs for cancer management. Although targeting the endothelin axis in cell lines and xenografts show some promise in retarding cellular growth, results from limited clinical trials in prostatic cancer are less encouraging and did not offer significant survival benefit. The ability to target both cancer cells and vasculature via endothelin is an important consideration that necessitates the further refining of therapeutic strategies as we continue to explore the possibilities of the endothelin axis in cancer treatment.