Individual variation in the pup attraction call produced by female Australian fur seals during early lactation

Otariid seals (fur seals and sea lions) are colonial breeders with large numbers of females giving birth on land during a synchronous breeding period. Once pups are born, females alternate between feeding their young ashore and foraging at sea. Upon return, both mother and pup must relocate each other and it is thought to be primarily facilitated by vocal recognition. Vocalizations of thirteen female Australian fur seals (Arctocephalus pusillus doriferus) were recorded during the breeding seasons of December 2000 and 2001, when pups are aged from newborns to one month. The pup attraction call was examined to determine whether females produce individually distinct calls which could be used by pups as a basis for vocal recognition. Potential for individual coding, discriminant function analysis (DFA), and classification and regression tree analysis were used to determine which call features were important in separating individuals. Using the results from all three analyses: F0, MIN F and DUR were considered important in separating individuals. In 76% of cases, the PAC was classified to the correct caller, using DFA, suggesting that there is sufficient stereotypy within individual calls, and sufficient variation between them, to enable vocal recognition by pups of this species.

Object classification under ignorance using CaRBS : the case of the European barn swallow

This article investigates the potential of a novel technique for object classification, called Classification and Ranking Belief Simplex (CaRBS), which is based on the Dempster-Shafer theory of evidence. As such, the classification of objects and the evidence from their characteristics have a level of ignorance associated with them. Its potential is exposited in the application of the classification of European barn swallows according to their gender. The classification of biological data in the presence of ignorance about such data sets is a common problem in biology. Comparisons of the results from CaRBS with those from multivariate discriminant analysis and neural networks are made. Also shown throughout the investigation is the interpretability of the results with the utilisation of the simplex plot method of representing data

Plumage reflectance and the objective assessment of avian sexual dichromatism

Assessment of color using human vision (or standards based thereon) is central to tests of many evolutionary hypotheses. Yet fundamental differences in color Vision between humans and other animals call this approach into question. Here we use techniques for objectively assessing color patterns that avoid reliance on species-specific (e.g., human) perception. Reflectance spectra are the invariant features that we expect the animal's color cognition to have evolved to extract. We performed multivariate analyses on principal components derived from >2,600 reflectance spectra (300-720 nm) sampled in a stratified random design from different body regions of male and female starlings in breeding plumage. Starlings possess spatially complex plumage patterns and extensive areas of iridescence. Our study revealed previously unnoticed sex differences in plumage coloration and the nature of iridescent and noniridescent sex differences. Sex differences occurred in some body regions bur not others, were more pronounced at some wavelengths (both ultraviolet and human visible), and involved differences in mean reflectance and spectral shape. Discriminant analysis based on principal components were sufficient to sex correctly 100% of our sample. If hidden sexual dichromatism is widespread, then it has important implications for classifications of animals as mono- or dimorphic and for taxonomic and conservation purposes.

Succession of small mammal communities after fire and reintroduction of the swamp antechinus 'Antechinus minimus'

This thesis is involved with changes that have occurred to small mammal populations following a major disturbance in the Anglesea region as a result of the 1983 Ash Wednesday fires. Fire, with its effects on spatial and temporal heterogeneity, was found to be an important factor in the maintenance of vegetation and small mammal community structure and diversity in the region. Successional changes in vegetation and small mammal communities were described by multivariate analyses, using data collected annually from 22 study sites. The use of factor analysis techniques, in reducing the annual capture data content, enabled long-term changes in the structure of mammal communities to be interpreted. The small mammal communities in the coastal heath and forest vegetation in the Anglesea region show evidence of a general resilience, (the degree and speed of recovery), to disturbance. Two phases of successional response to fire by mammal species have been proposed; a ‘re-establishment’ phase which occurs in the initial 5-6 years post-fire and is accompanied by rapid increase in species’ abundance, and a subsequent ‘maintenance’ phase accompanied by relatively minor changes in abundance. Habitat Suitability Indices were produced relating to these phases. Vertical density measures of understorey shrubs and herb layers showed significant relationships with small mammal species abundance at the study sites. Long term studies following major disturbances are needed to distinguish between short term recovery of plant and animal species and long term changes in these species. Studies extending over a number of years enable a better directional view of changes in small mammal communities than can be determined from . observations made over a short period. As a part of the investigation into temporal change, it was proposed to undertake trial reintroductions of the Swamp antechinus, Ant echinus minimus, a marsupial dasyurid species which was trapped in the area prior to the 1983 fire, but rarely subsequently. Other more commonly observed native small mammal species (e.g. Rattus fuscipes,R. lutreolus, Antechinus stuartii, Sminthopsis leucopus) had re-invaded the proposed reintroduction site after this fire. Failure of A. minimus to re-establish may have been due to spatial separation of the pre-fire populations coupled with the extensive area burnt in 1983, A source population of the species was located about 100km to the west and habitat utilization and interspecific and niche relationships between the species making the small mammal community explored. Discriminant analysis revealed some spatial separation of species within a habitat based on structural vegetation factors rather than floristic factors. Temporal separation of species was observed, asA. minimus were more active than Rattus species during daylight periods. There was evidence of micro-habitat selection by species, and structural vegetation factors were most commonly identified in statistical analyses as contributing towards selection by small mammal species. Following a theoretical modelling study three reintroduction trials were carried out near Anglesea during 1992-94. Individuals were subsequently radio tracked, and habitat relationships between the species in the small mammal community investigated. Although successful breeding of A, minimus occurred during the latter two trials, the subsequent fate of offspring was not determined. Invasive techniques required to adequately monitor young animals were considered potentially too damaging. Telemetry studies indicated a preference of A. minimus for short, wet heath vegetation. Structural vegetation factors were identified as being significant in discriminating between capture locations of species. Small scale and inexpensive trial reintroductions have yielded valuable additional data on this species and may be viewed as a useful tool in the conservation of other small native mammals.

Investigation of educator adoption of knowledge media

Human development has occurred against a timeline that has seen the creation of and diffusion of one innovation after another. These innovations range from language to complex computing and information technologies. The latter are assisting with the distribution of information, and extend to the distribution of the human species beyond the planet Earth. From early times, information has been published and mostly for a fee to the publisher. The absorption and use of information has had a high priority in most societies from early times, and has become institutionalised in universities and institutes of technical learning. For most in Western societies, education is now a matter of ‘lifelong learning’. Today, we see higher education institutions, worldwide, adapting their organisational structures and operating procedures and forming strategic alliances with communications content providers and carriers as well as with information technology companies. Modern educational institutes seek productivity and efficiency. Many also seek to differentiate themselves from competitors. Technological convergence is often seen by management to be a saviour in many educational organisations. It is hoped that lower capital and recurrent costs can be achieved, and that competitors in an increasingly globalised industry can be held at bay by strategic use of knowledge media (Eisenstadt, 1995) commonly associated with distance education in the campus setting. Knowledge media set up costs, intellectual property costs and training costs for staff and students are often so high as to make their use not viable for Australian institutes of higher education. Against this backdrop, one might expect greater educator and student use of publisher produced textbooks and digital enhancements to the textbook, particularly those involved in distance education. A major issue is whether or not the timing of instructor adoption of converging information technology and communications technologies aligns with the wishes of both higher education management and government, and with those who seek commercial gain from the diffusion and adoption of such technologies. Also at issue is whether or not it is possible to explain variance in stated intentions to recommend adoption of new learning technologies in higher education and implementation. Will there occur educator recommendation for adoption of individual knowledge media such as World Wide Web access to study materials by students? And what will be the form of this tool and others used in higher education? This thesis reports on more recent changes in the technological environment and seeks to contribute to an understanding of the factors that lead to a willingness, or unwillingness, on the part of higher education instructors, as influencers and content providers, to utilise these technologies. As such, it is a diffusion study which seeks to fill a gap in the literature. Diffusion studies typically focus on predicting adoption based on characteristics of the potential adopter. Few studies examine the relationship between characteristics of the innovation and adoption. Nearly all diffusion studies involve what is termed discontinuous innovation (Robertson, 1971). That is, the innovation involves adoptees in a major departure from previous practice. This study seeks to examine the relationship between previous experience of related technologies and adoption or rejection of dynamically continuous innovation. Continuous and dynamically continuous innovations are the most numerous in the real world, yet they are numerically the least scrutinised by way of academic research. Moreover, the three-year longitudinal study of educators in Australian and New Zealand meets important criteria laid down by researchers Tornatzky and Klein (1982) and Rogers (1995), that are often not met by similar studies. In particular the study examines diffusion as it is unfolding, rather than selectively examining a single innovation and after the fact, thus avoiding a possible pro-innovation bias. The study examines the situation for both ‘all educators’ and ‘marketing / management educators’ alone in seeking to meet the following aim: Establish if intended adopters of specific knowledge media have had more experience of other computer-based technologies than have those not intending to adopt said knowledge media. The analytical phase entails use of factor analysis and discriminant analysis to conclude that it is possible to discriminate adopters of selected knowledge media based on previous use of related technologies. The study does not find any generalised factor that enables such discrimination among educators. Thus the study supports the literature in part, but fails to find generalised factors that enable unambiguous prediction of knowledge media adoption or otherwise among each grouping of educators examined. The implications are that even in the case of related products and services (continuous or dynamically continuous innovation), there is not statistical certainty that prior usage of related products or technologies is related to intentions to use knowledge media in the future. In this regard, the present study might be said to confirm the view that Rogers and Shoemaker's (1971) conceptualisation of perceived innovation characteristics may only apply to discontinuous innovations (Stratton, Lumpkin & Vitell, 1997). The implications for stakeholders such as higher education management is that when seeking to appoint new educators or existing staff to knowledge media project teams, there is some support for the notion that those who already use World Wide Web based technologies are likely to take these technologies into teaching situations. The same claim cannot be made for computer software use in general, nor Internet use in general.

Retrospective application of remote sensing to the Tasmanian lakeland

This thesis describes the research undertaken for a degree of Master of Science in a retrospective study of airborne remotely sensed data registered in 1990 and 1993, and field captured data of aquatic humus concentrations for ~ 45 lakes in Tasmania. The aim was to investigate and describe the relationship between the remotely sensed data and the field data and to test the hypothesis that the remotely sensed data would establish further evidence of a limnological corridor of change running north-west to south- east. The airborne remotely sensed data consisted of data captured by the CSIRO Ocean Colour Scanner (OCS) and a newly developed Canadian scanner, a compact airborne spectrographic imager (CASI). The thesis investigates the relationship between the two kinds of data sources. The remotely sensed data was collected with the OCS scanner in 1990 (during one day) and with both the OCS and the CASI in 1993 (during three days). The OCS scanner registers data in 9 wavelength bands between 380 nm and 960 nm with a 10-20 nm bandwidth, and the CASI in 288 wavelength bands between 379.57 nm and 893.5 nm (ie. spectral mode) with a spectral resolution of 2.5 nm. The remotely sensed data were extracted from the original tapes with the help of the CSIRO and supplied software and digital sample areas (band value means) for each lake were subsequently extracted for data manipulation and statistical analysis. Field data was captured concurrently with the remotely sensed data in 1993 by lake hopping using a light aircraft with floats. The field data used for analysis with the remotely sensed data were the laboratory determined g440 values from the 1993 water samples collated with g440 values determined from earlier years. No spectro-radiometric data of the lakes, data of incoming irradiance or ancillary climatic data were captured during the remote sensing missions. The sections of the background chapter in the thesis provide a background to the research both in regards to remote sensing of water quality and the relationship between remotely sensed spectral data and water quality parameters, as well as a description of the Tasmanian lakes flown. The lakes were divided into four groups based on results from previous studies and optical parameters, especially aquatic humus concentrations as measured from field captured data. The four groups consist of the ‘green” clear water lakes mostly situated on the Central Plateau, the ‘brown” highly dystrophic lakes in western Tasmania, the ‘corridor” lakes situated along a corridor of change lying approximately between the two lines denoting the Jurassic edge and 1200 mm isohyet, and the ‘eastern, turbid” lakes make up the fourth group. The analytical part of the research work was mostly concerned with manipulating and analysing the CASI data because of its higher spectral resolution. The research explores methods to apply corrections to this data to reduce the disturbing effects of varying illumination and atmospheric conditions. Three different methods were attempted. In the first method two different standardisation formulas are applied to the data as well as ‘day correction” factors calculated from data from one of the lakes, Lake Rolleston, which had data captured for all three days of the remote sensing operations. The standardisation formulas were also applied to the OCS data. In second method an attempt to reduce the effects of the atmosphere was performed using spectro-radiometric captured in 1988 for one of the lakes flown, Great Lake. All the lake sample data were time normalised using general irradiance data obtained from the University of Tasmania and the sky portion as calculated from Great Lake upwelling irradiance data was then subtracted. The last method involved using two different band ratios to eliminate atmospheric effects. Statistical analysis was applied to the data resulting from the three methods to try to describe the relationship between the remotely sensed data and the field captured data. Discriminant analysis, cluster analysis and factor analysis using principal component analysis (pea) were applied to the remotely sensed data and the field data. The factor scores resulting from the pca were regressed against the field collated data of g440 as were the values resulting from last method. The results from the statistical analysis of the data from the first method show that the lakes group well (100%) against the predetermined groups using discriminant analysis applied to the remotely sensed CASI data. Most variance in the data are contained in the first factor resulting from pca regardless of data manipulation method. Regression of the factor scores against g440 field data show a strong non- linear relationship and a one-sided linear regression test is therefore considered an inappropriate analysis method to describe the dataset relationships. The research has shown that with the available data, correction and analysis methods, and within the scope of the Masters study, it was not possible to establish the relationships between the remotely sensed data and the field measured parameters as hoped. The main reason for this was the failure to retrieve remotely sensed lake signatures adequately corrected for atmospheric noise for comparison with the field data. This in turn is a result of the lack of detailed ancillary information needed to apply available established methods for noise reduction - to apply these methods we require field spectroradiometric measurements and environmental information of the varying conditions both within the study area and within the time frame of capture of the remotely sensed data.

Spatial discretization of discrete dynamical systems

Investigates what can go wrong when dynamical systems are modelled with a computer. Number theoretic techniques were used to detail the effects "discretization" errors caused by computer round-off had on characteristics of a system. In particular, a relationship was established between the occurrence of long cycles in a system and the classical result known as Artin's conjecture. Algorithms were then developed which eliminated discretization errors.

Post-prandial remnant lipids impair arterial compliance

OBJECTIVES
We sought to examine the effects of plasma lipids, especially in remnants after a fat meal, on systemic arterial compliance (SAC), a newly recognized cardiovascular risk factor.
BACKGROUND
Post-prandial remnants correlate with coronary heart disease events through mechanisms that may include vascular dysfunction, although the effect on SAC has not been studied.
METHODS
Systemic arterial compliance was measured non-invasively over 6 h after a fat meal in 16 subjects with varying plasma triglyceride levels. Changes were related to rises in plasma lipids and remnant lipids. Systemic arterial compliance was measured in 20 subjects after a control low-fat meal.
RESULTS
The fat meal induced increments in plasma triglyceride and remnant cholesterol and triglyceride (respectively +54%, 50% and 290% at 3 h, analysis of variance <0.001). Systemic arterial compliance fell at 3 h and 6 h by 25% and 27% (analysis of variance <0.001). Baseline SAC correlated significantly with all lipid concentrations at 0, 3 h and 6 h, but only with triglyceride on stepwise regression analysis. The SAC response to the low-fat meal was very small and not significant.
CONCLUSIONS
This is the first demonstration of SAC becoming impaired after a fat meal. Remnant lipids and plasma total triglyceride appeared to contribute to the fall in SAC.

Application of neural networks in modelling serviceability deterioration of concrete stormwater pipes

Stormwater pipe systems in Australia are designed to convey water from rainfall and surface runoff only and do not transport sewage. Any blockage can cause flooding events with the probability of subsequent property damage. Proactive maintenance plans that can enhance their serviceability need to be developed based on a sound deterioration model. This paper uses a neural network (NN) approach to model deterioration in serviceability of concrete stormwater pipes, which make up the bulk of the stormwater network in Australia. System condition data was collected using CCTV images. The outcomes of model are the identification of the significant factors influencing the serviceability deterioration and the forecasting of the change of serviceability condition over time for individual pipes based on the pipe attributes. The proposed method is validated and compared with multiple discriminant analysis, a traditionally statistical method. The results show that the NN model can be applied to forecasting serviceability deterioration. However, further improvements in data collection and condition grading schemes should be carried out to increase the prediction accuracy of the NN model.

A brief review of recent research trends on applications of computational and statistical techniques in financial and business intelligence

Artificial neural networks and statistical techniques like decision trees, discriminant analysis, logistic regression and survival analysis play a crucial role in Business Intelligence. These predictive analytical tools exploit patterns found in historical data to make predictions about future events. In this paper we have shown some recent developments of a few of these techniques in financial and business intelligence applications like fraud detection, bankruptcy prediction and credit rating scoring.

How well does the index of receptivity to tobacco industry promotion discriminate between smoking and never smoking adolescents.

Tobacco advertising is often named as the culprit that causes children to start smoking (Lancaster & Lancaster, 2003). This belief can partly be attributed to the Index of Receptivity to Tobacco Industry Promotion (IRTIP) developed by Evans, Farkas, Gilpin, Berry, & Pierce (1995). IRTIP was later modified and used by Pierce, Choi, Gilpin, Farkas, & Berry (1998) in a longitudinal study that claimed to have found a causal link between advertising and adolescent cigarette trial. The model is advertised by the American National Cancer Institute (2004) as being able to measure the likelihood of an adolescent starting smoking. Because of Pierce’s causality claim and this endorsement, IRTIP has been widely adopted by tobacco-control researchers. Consequently, the results from IRTIP based surveys have played a central role in influencing tobacco control policy. Based on the logic that a model used to predict the chances of a non-smoker becoming a smoker should be able to distinguish between these two groups, discriminant analysis with dummy coded variables was used to validate IRTIP. The results show that while IRTIP classifies never-smokers well, it grossly misclassifies smokers. This leads to questions about the validity of the model and of studies using IRTIP.

Consumers who don't want to look for information

A model to identify and classify consumers with high resistance to searching for information (HRSI) was developed and tested. We found that individuals with high levels of confidence about a purchase but who also ascribed low levels of personal importance to the transaction were significantly (p=.004) more likely to be HRSI. Using Multiple Discriminant Analysis, our model classified and predicted HRSI consumers well (p=.004, 57% above chance) but not low-resistance consumers (p=.6, 26.4% below chance).

Association between abnormal psychosocial situations in childhood, generalised anxiety disorder and oppositional defiant disorder

Objective: Psychosocial stressors are important in the pathogenesis of most mental disorders. However, little is known about the way psychosocial stressors uniquely combine to create risk for different expressions of child and adolescent psychopathology. The purpose of this study was to determine whether core dimensions of stressful psychosocial situations are differentially associated with childhood generalized anxiety disorder and oppositional defi ant disorder.

Method: A case-control design conducted in Trondheim (Norway) from 2002 to 2004 comparing exposure to ICD-10-defi ned abnormal psychosocial situations (Z-codes) among 21 children with oppositional defi ant disorder (ODD) and 22 children with generalized anxiety disorder (GAD) recruited from a university outpatient clinic with 42 non-patient school controls.

Results: Multigroup discriminant analysis extracted two signifi cant dimensions within the psychosocial variables assessed. Function 1 was characterized by overprotection, parental pressures and acute life events and was associated with GAD. Function 2 was characterized by parental abuse/hostility and interpersonal stress and was associated with ODD. Both dimensions were able to correctly classify 89.7% of the cases, compared to 35.9% by chance.

Conclusions: The results indicate that specifi c psychosocial dimensions are differentially related to childhood GAD and ODD. This may be useful in targeting at-risk populations for preventive intervention as well as informing more accurate alignment of psychosocial resources for treatment.

Application of epidemiology to change health policy : defining age-related thresholds of bone mineral density for primary prevention of fracture

In Australia, benefits for antifracture therapies have been available for patients with osteoporosis and a prior fracture. No benefits were available to those with no prior fracture. We aimed to define, in women with no prior fracture, age-related thresholds of bone mineral density (BMD) associated with fracture risk equivalent to that of women with prior fracture and osteoporosis. A case-control study of women (≥50 yr) was conducted, including 291 fracture cases and 823 controls. BMD was measured at the proximal femur and posterior anterior (PA) spine. A fracture risk score (FRS) for the group with no prior fracture was calculated with discriminant analysis. The thresholds for equivalent fracture risk between those with no prior fracture and those with prior fracture were assessed using logistic regression. Increasing the FRS to +0.98 in women with no prior fracture resulted in equivalent odds of sustaining a fracture to those with prior fracture and osteoporosis. The corresponding T-score thresholds at the spine were −4.6 at 50 yr, −3.9 at 60 yr, −3.1 at 70 yr, and −2.4 at 80 yr. The femoral neck T-score thresholds were lower by 0.5 standard deviation. The high-risk individuals defined by this study should be considered for primary fracture prevention therapy.

Fracture thresholds revisited : Geelong Osteoporosis Study

Osteoporosis, in the absence of fracture, is defined as a deficit in bone mineral density (BMD) of 2.5 SD or more below the young adult reference mean in postmenopausal Caucasian populations. BMD is a measure of fracture risk but not the sole predictor. We have assessed a combination of easily accessible measures of age, height, weight, and BMD to improve fracture risk assessment. Women with low trauma fractures and a control group were recruited from south-eastern Australia. Discriminant analysis derived multivariate equations that assessed fracture risk. Age was not in the best models at the spine and forearm sites. Weight and height contributed to the relationship for the forearm sites only. At the proximal femur, the BMD level that separates fracture cases from nonfracture cases, increases with age. These separation levels of BMD were higher than the WHO's level of osteoporosis (T-score < −2.5 SD) at ages older than 62 years. This increasing BMD threshold with age suggests that other age-related risk factors assume increasing importance among the elderly.