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.

Employee psychological contracts

This thesis concerns the psychological contracts of employees. A psychological contract is an employee’s perception that: 1) an employer has certain obligations to them, and 2) in return, they have obligations as employees. A psychological contract is therefore a set of subjectively perceived reciprocal obligations. The psychological foundations of this construct are linked with cognitive schemas and social exchange theories. While the concept of psychological contracts was first proposed in the early 1960s, it has only been operationalised for empirical study in the last decade. The purpose of the thesis was to increase the understanding of the content and structure of employee psychological contracts and their links with career cognitions. The specific aims of the thesis were to: 1) examine the relational-transactional dimensions of psychological contracts, 2) develop a comprehensive set of workplace obligations for use with employees, 3) consider alternative dimensions of employee psychological contracts, 4) demonstrate reciprocity between obligations, and 5) determine whether psychological contracts directly affect career cognitions. The thesis contains four quantitative studies. Data were collected using self-report questionnaires that contained both established and new measures. Most participants were employees from a large insurance company, government vocational services or educational institutions. The analyses included canonical correlation, factor analysis, development of measurement models and structural analysis. The findings did not strongly support a distinction between relational and transactional obligations. Instead, a five-factor model of psychological contracts emerged from an expanded set of workplace obligations when it was used with two separate employee samples. This model demonstrated reciprocal relationships between the dimensions of employee and employer obligations. It was also found that alternative dimensions of the psychological contract have a direct influence on organisational commitment and career satisfaction. The thesis supports several general conclusions about the nature of employee psychological contracts, appropriate measures and future research. General workplace obligations that apply across different workplaces can be found, and these should continue to be refined. Such workplace obligations group in meaningful ways, and they can be usefully studied in terms of employer support and employee attitudes to work, rather than in terms of relational and transactional dimensions. Furthermore, this thesis shows that reciprocity in psychological contracts can be demonstrated by correlations between dimensions of employee and employer obligations. The measure used for studying reciprocity was new, and it requires further work. However, this measure is as reliable and valid as any currently available. Measurement is the single most urgent issue facing researchers. Finally, this thesis provides sufficient empirical evidence to support the claim that psychological contracts are an important variable for the understanding of careers.

Genetic and environmental influences on variation in balance performance among female twin pairs aged 21-82 years

Genetic and environmental influences on variation in balance performance were measured in 93 monozygous and 83 dizygous female twin pairs aged 21–82 years (mean age, 50.5 years) in Melbourne, Australia, between 1999 and 2003. The authors administered clinical (Lord's Balance Test and Step Test) and laboratory tests of static and dynamic balance from the Chattecx Balance System with and without distractor tasks. The authors conducted factor analysis and estimated genetic and environmental variance components and heritability (defined as additive genetic variance as a proportion of all variance, after adjustment for age) using a multivariate normal model with the statistical package FISHER. Three factors were identified and adjusted for age. Heritability was 46% (standard error (SE), 9) for the "sensory balance tests" factor and 30% (SE, 9) for the "static and dynamic perturbations" factor. For both factors, the remaining variance was attributed to unique environmental effects. There was no evidence that genetic factors influenced variation in the "dynamic weight shift tests" factor, with environmental effects shared by twins accounting for 38% (SE, 7) of variance. Neither genetic nor environmental proportions of variance differed significantly between twin subgroups by age (≤50/>50 years). An age-related decline in performance measures was found across the whole sample. These results imply that balance impairments may have a heritable element.

Quality of life assessment in the community-dwelling elderly : validation of the Assessment of Quality of Life (AQoL) instrument and comparison with the SF-36

Measurement of Health-Related Quality of Life (HRQoL) of the elderly requires instruments with demonstrated sensitivity, reliability, and validity, particularly with the increasing proportion of older people entering the health care system. This article reports the psychometric properties of the 12-item Assessment of Quality of Life (AQoL) instrument in chronically ill community-dwelling elderly people with an 18-month follow-up. Comparator instruments included the SF-36 and the OARS. Construct validity of the AQoL was strong when examined via factor analysis and convergent and divergent validity against other scales. Receiver Operator Characteristic (ROC) curve analyses and relative efficiency estimates indicated the AQoL is sensitive, responsive, and had the strongest predicative validity for nursing home entry. It was also sensitive to economic prediction over the follow-up. Given these robust psychometric properties and the brevity of the scale, AQoL appears to be a suitable instrument for epidemiologic studies where HRQoL and utility data are required from elderly populations.

Association of western and traditional diets with depression and anxiety in women

Objective: Key biological factors that influence the development of depression are modified by diet. This study examined the extent to which the high-prevalence mental disorders are related to habitual diet in 1,046 women ages 20–93 years randomly selected from the population.

Method: A diet quality score was derived from answers to a food frequency questionnaire, and a factor analysis identified habitual dietary patterns. The 12-item General Health Questionnaire (GHQ-12) was used to measure psychological symptoms, and a structured clinical interview was used to assess current depressive and anxiety disorders.

Results: After adjustments for age, socioeconomic status, education, and health behaviors, a "traditional" dietary pattern characterized by vegetables, fruit, meat, fish, and whole grains was associated with lower odds for major depression or dysthymia and for anxiety disorders. A "western" diet of processed or fried foods, refined grains, sugary products, and beer was associated with a higher GHQ-12 score. There was also an inverse association between diet quality score and GHQ-12 score that was not confounded by age, socioeconomic status, education, or other health behaviors.

Conclusions: These results demonstrate an association between habitual diet quality and the high-prevalence mental disorders, although reverse causality and confounding cannot be ruled out as explanations. Further prospective studies are warranted.

Psychometric properties of the DASS-21 in Malaysia

The use of scales to measure constructs in populations or contexts other than that in which they were normed is highly controversial. Despite this, the use of scales without reference to 'local' norms is still widespread. In this study we examine the reliability, factor structure and convergent validity of the short form of the Depression, Anxiety and Stress Scales (DASS-21), in a convenience sample of 191 people recruited from the general population in Malaysia. Confirmatory factor analysis suggests that a three factor solution provides an acceptable fit, however these three factors are highly correlated. Scores on the depression, anxiety, and stress scales of the DASS-21 correlate with the BDI-II at only moderate levels, suggesting that convergent validity of the depression scale is weak, and that there are not differential relationships between the BDI-II and the three DASS scales. Issues related to the possible role of cultural factors in response patterns, and the need for a greater understanding of the manifestations of psychological distress and how it relates the DASS-21 scales in Malaysia are discussed.

Dietary patterns, assessed from a weighed food record, and survival among elderly participants from the United Kingdom

Background/Objectives: There is variability in the association between dietary intake and health outcomes across different countries, especially among the elderly. We used the gold standard dietary assessment method, a weighed food record, to examine the association between dietary pattern and mortality in a representative sample of community dwelling participants from Great Britain aged 65 years and older.

Subjects/Methods: Dietary intake was recorded at baseline in 1017 elderly participants (520 men, 497 women, mean age 76.3±7.4 years). Exploratory factor analysis was performed to examine dietary patterns and participants were followed up over an average of 9.2 years for mortality.

Results: The factor analysis revealed four interpretable principal components accounting for approximately 9.8% of the total variance, with similar patterns across sex. A ‘Mediterranean-style’ dietary pattern explained the greatest proportion of the variance (3.7%), followed by ‘health-aware’ (2.2%), ‘traditional’ (2.0%) and ‘sweet and fat’ (1.9%) factors. There were a total of 683 deaths through follow-up. After adjustment for potential confounders, only the Mediterranean-style dietary pattern remained associated with mortality (highest vs lowest tertile; hazard ratio¼0.82, 95% CI, 0.68–1.00). The benefits of the Mediterranean-style diet were only observed among women (hazard ratio¼0.71, 95% CI 0.52–0.96) although in men the traditional diet was a risk factor for mortality (hazard ratio¼1.30, 95% CI 1.00–1.71).

Conclusions: Using a gold standard approach, our results confirm previous evidence that dietary patterns are important in longevity among the elderly.

Validity and reliability of instruments to assess potential mediators of children's physical activity : a systematic review

This paper aimed to (1) identify potential mediators reported in children's physical activity interventions; and (2) review the psychometric properties of measures of potential mediators included in such interventions. A systematic search of the literature was conducted and studies that reported potential mediators and/or the psychometric properties of measures of potential mediators were retrieved and reviewed. The studies were reviewed for the following psychometric properties: face/logical, construct, and criterion validity; and test–retest and internal consistency (factor analysis and Cronbach's α) reliability. Twenty-one potential mediators were identified from 24 published children's physical activity intervention studies; 17 individual, three social, and one physical environmental. Overall, there was considerable variation in the reporting of the psychometric properties of these measures. Reliability properties (specifically Cronbach's α) were more commonly reported than validity properties; however, for many potential mediators, the quality of these measures was low. Future studies should examine the psychometric properties of measures of potential mediators to ensure appropriate, valid and reliable instruments are used. This will assist in the ability to accurately determine the efficacy of physical activity interventions among children.

Measurement and structural properties of organizational codes of ethics in private and public Sweden

Purpose – The purpose of this paper is to test the measurement and structural properties in a model of organizational codes of ethics (OCE) in Sweden.

Design/methodology/approach – The measurement and structural properties of four OCE constructs (i.e. surveillance/training, internal communication, external communication, and guidance) were described and tested in a dual sample based upon private and public sectors of Sweden.

Findings – Results show that the measurement and structural models of OCE in part have a satisfactory fit, validity, and reliability.

Research limitations/implications – The paper makes a contribution to theory as it outlines a set of OCE constructs and it presents an empirical test of and OCE model in respect to measurement and structural properties. A number of research limitations are provided.

Practical implications – It provides a model to be considered in the implementation and monitoring of OCE. The present research provides opportunities for further research in refining, extending, and testing the proposed OCE model in other cultural and organizational settings.

Originality/value – The OCE model extends previous studies that have been predominately descriptive, by using confirmatory factor analysis and structural equation modeling.

A multi-component assessment model for monitoring training distress among athletes

We report the initial validation of a multi-component assessment model for monitoring training distress among athletes. The model combines measures of mood disturbance with measures of perceived stress and symptom intensity. Altogether, 492 athletes completed the 10-item Perceived Stress Scale (PSS-10; Cohen et al., 1983), the 24-item Brunel Mood Scale (BRUMS; Terry et al., 2003), and a checklist of 19 symptoms associated with acute overtraining (Fry et al., 1994). Six training distress factors were identified by an exploratory factor analysis: ‘‘depressed mood’’, ‘‘perceived vigour’’, ‘‘physical symptoms’’, ‘‘sleep disturbance’’, ‘‘perceived stress’’, and ‘‘general fatigue’’. Comparisons of group means of these factors with a previously validated inventory were consistent with theoretical predictions and provided evidence of construct validity. Internal consistency of the subscales was also confirmed, with Cronbach alphas ranging from 0.72 to 0.86. Together, these findings suggest that this multi-component model provides a sound conceptual basis for the assessment of training distress among athletes.

Major dietary patterns of young and middle aged women : results from a prospective Australian cohort study

Objective: The aim of this study was to assess the major dietary patterns of two age cohorts of women, to determine to the extent to which the dietary patterns differ between the cohorts and to assess whether they vary according to sociodemographic and behavioural characteristics and patterns of nutrient intake.

Method: Dietary intake was assessed using an 80-item food frequency questionnaire for women aged 50–55 years (n=10 150; ‘middle age’) in 2001 and aged 25–30 years (n=7371; ‘young’) in 2003, from the Australian Longitudinal Study on Women's Health. Factor analysis using principal component extraction was used to identify dietary patterns, and a pattern score was calculated from the consumption of the food items identified with each dietary pattern. Associations between the dietary pattern scores and sociodemographic and behavioural characteristics and nutrient intakes were investigated using regression analysis.

Results: Six dietary patterns were identified and were labelled: cooked vegetables; fruit; Mediterranean-style; processed meat, meat and takeaway; reduced fat dairy; and high-fat and sugar foods. Regression analysis revealed that healthier dietary patterns were significantly associated with other favourable health-related behaviours, higher socioeconomic status and living in urban areas (P-values <0.05).

Conclusions: In spite of differences in the level of consumption of individual food items, the similarity in dietary patterns across two generations of women suggests that policies and interventions to improve diet should focus on social and economic factors and general health-related behaviour rather than different age groups.

Exploring critical success factors for stakeholder management in construction projects

With a focus on different aspects of stakeholder management, various sets of critical success factors (CSFs) have been suggested in the literature. It is crucial to explore the relative importance and groupings of these factors. This paper aims to identify CSFs associated with stakeholder management in construction projects, and explore their ranking and underlying relationship. 15 CSFs were identified through a literature review, and consolidated by interviews and pilot studies with professionals in construction industry. A questionnaire instrument containing these 15 CSFs was sent out to project managers in Hong Kong, and 183 completed questionnaires were retrieved. The top three ranked factors for stakeholder management were "managing stakeholders with social responsibilities", "assessing the stakeholders' needs and constraints to the project", and "communicating with stakeholders properly and frequently". Using factor analysis and considering the high importance of the factor "managing stakeholders with social responsibilities", the 15 CSFs were grouped into five dimensions namely, precondition factor, stakeholder estimation, information inputs, decision making, and sustainable support. All these five groupings and their relationship were included in a framework for successful stakeholder management in construction projects. These findings help to clarify what the high prioritized factors are, and could also be used as an assessment tool to evaluate the performance of stakeholder management and thus help to identify areas for improvement.

A step toward a common measure of organizational justice

Dimensions of the organizational justice construct were examined in a public sector context utilizing an organizational justice measure developed by Colquitt in 2001. Exploratory factor analysis and standard error scree test supported four dimensions of justice as measured by Colquitt's scale. There was evidence of a new factor called procedural-voice justice that taps a possible association with the concept of voice. Future research on organizational justice must investigate its dimensionality based on more representative samples to develop a more globally applicable measure.

Screening children with developmental coordination disorder : the development of the caregiver assessment of movement participation

This study investigated the psychometric properties of the Caregiver Assessment of Movement Participation (CAMP), which was developed to measure and identify children with movement participation problems in home contexts. The test-retest reliability, as well as the concurrent and contrast-group validity of the 35-item parent-proxy CAMP, was examined on 312 children aged 5 to 8 years using intraclass correlation, factor analysis, and the Rasch model. Initial findings on the CAMP appeared to support its validity. Testing on other properties from a practical perspective, such as finding the best rating scale structure and cutpoints, are recommended before using the instrument for child health surveillance screening.

Management control systems use, organisational capabilities and performance in universities: application of the resource-based view

Invoking the resource-based view (RBV), this study investigates relationships between management control systems (MCSs) use, including information use from performance measurement systems (PMSs), and organisational capabilities in the context of academic units of Australian universities. Increased competition and attention to distinctive capabilities amongst universities, particularly at their strategic operating unit level of Schools 1, provides the setting for application of this theoretic perspective. The objective of this study is to model various relationships between diagnostic and interactive use of MCSs, attention given to centrally-imposed and discretionary types of PMS information, the strength of capabilities of the academic unit and, in turn, performance of the academic units. This objective is investigated using a field survey in which a mail survey instrument is administered to a census of all Heads of Schools in all 39 universities in Australia. Valid responses were received from 166 Heads. Principal components factor analysis finds that Heads conceived capabilities of their unit in functional dimensions, not in generic dimensions as found in prior literature; Heads also considered performance measures in terms of their importance (critical or discretionary) rather than type (financial versus non-financial). Partial least-squares analysis is then used for path modelling, and several significant results are obtained. Highlights are that diagnostic MCS use and centrally-imposed performance measures, i.e., key performance indicators, but not interactive MCS use or discretionary performance measures, significantly relate to some or all of the strength of capabilities in the fields of teaching, research and networking, and in turn indirectly relate to performance of the academic units. The findings have practical implications for styles of control systems use; focus on selected key performance measures; and development of organisational capabilities for achievement of superior performance by academic schools in universities.