An ecology of centre-based child care

The studies in the thesis were derived from a program of research focused on centre-based child care in Australia. The studies constituted an ecological analysis as they examined proximal and distal factors which have the potential to affect children's developmental opportunities (Bronfenbrenner, 1979). The project was conducted in thirty-two child care centres located in south-east Queensland. Participants in the research included staff members at the centres, families using the centres and their children. The first study described the personal and professional characteristics of one hundred and forty-four child care workers, as well as their job satisfaction and job commitment. Factors impinging on the stability of care afforded to children were examined, specifically child care workers' intentions to leave their current position and actual staff turnover at a twelve month follow-up. This is an ecosystem analysis (Bronfenbrenner & Crouter, 1983), as it examined the world of work for carers; a setting not directly involving the developing child, but which has implications for children's experiences. Staff job satisfaction was focused on working with children and other adults, including parents and colleagues. Involvement with children was reported as being the most rewarding aspect of the work. This intrinsic satisfaction was enough to sustain caregivers' efforts to maintain their employment in child care programs. It was found that, while improving working conditions may help to reduce turnover, it is likely that moderate turnover rates will remain as child care staff work in relatively small centres and they leave in order to improve career prospects. Departure from a child care job appeared to be as much about improving career opportunities or changing personal circumstances, as it was about poor wages and working conditions. In the second study, factors that influence maternal satisfaction with child care arrangements were examined. The focus included examination of the nature and qualities of parental interaction with staff. This was a mesosystem analysis (Bronfenbrenner & Crouter, 1983), as it considered the links between family and child care settings. Two hundred and twenty-two questionnaires were returned from mothers whose children were enrolled in the participating centres. It was found that maternal satisfaction with child care encompassed the domains of child-centred and parent-centred satisfaction. The nature and range of responses in the quantitative and qualitative data indicated that these parents were genuinely satisfied with their children's care. In the prediction of maternal satisfaction with child care, single parents, mothers with high role satisfaction, and mothers who were satisfied with the frequency of staff contact and degree of supportive communication had higher levels of satisfaction with their child care arrangements. The third study described the structural and process variations within child care programs and examined program differences for compliance with regulations and differences by profit status of the centre, as a microsystem analysis (Bronfenbrenner, 1979). Observations were made in eighty-three programs which served children from two to five years. The results of the study affirmed beliefs that nonprofit centres are superior in the quality of care provided, although this was not to a level which meant that the care in for-profit centres was inadequate. Regulation of structural features of child care programs, per se, did not guarantee higher quality child care as measured by global or process indicators. The final study represented an integration of a range of influences in child care and family settings which may impact on development. Features of child care programs which predict children's social and cognitive development, while taking into account child and family characteristics, were identified. Results were consistent with other research findings which show that child and family characteristics and child care quality predict children's development. Child care quality was more important to the prediction of social development, while family factors appeared to be more predictive of cognitive/language development. An influential variable predictive of development was the period of time which the child had been in the centre. This highlighted the importance of the stability of child care arrangements. Child care quality features which had most influence were global ratings of the qualities of the program environment. However, results need to be interpreted cautiously as the explained variance in the predictive models developed was low. The results of these studies are discussed in terms of the implications for practice and future research. Considerations for an expanded view of ecological approaches to child care research are outlined. Issues discussed include the need to generate child care research which is relevant to social policy development, the implications of market driven policies for child care services, professionalism and professionalisation of child care work, and the need to reconceptualise child care research when the goal is to develop greater theoretical understanding about child care environments and developmental processes.

Real estate 2.0 : towards a value ecology?

This paper anatomises emerging developments in online community engagement in a major global industry: real estate. Economists argue that we are entering a ‘social network economy’ in which ‘complex social networks’ govern consumer choice and product value. In the light of this, organisations are shifting from thinking and behaving in the conventional ‘value chain’ model--in which exchanges between firms and customers are one-way only, from the firm to the consumer--to the ‘value ecology’ model, in which consumers and their networks become co-creators of the value of the product. This paper studies the way in which the global real estate industry is responding to this environment. This paper identifies three key areas in which online real estate ‘value ecology’ work is occurring: real estate social networks, games, and locative media / augmented reality applications. Uptake of real estate applications is, of course, user-driven: the paper not only highlights emerging innovations; it also identifies which of these innovations are actually being taken up by users, and the content contributed as a result. The paper thus provides a case study of one major industry’s shift into a web 2.0 communication model, focusing on emerging trends and issues.

Influence of historical landscapes, drainage evolution and ecological traits on patterns of genetic diversity in Southeast Asian freshwater snakehead fishes

Snakehead fishes in the family Channidae are obligate freshwater fishes represented by two extant genera, the African Parachannna and the Asian Channa. These species prefer still or slow flowing water bodies, where they are top predators that exercise high levels of parental care, have the ability to breathe air, can tolerate poor water quality, and interestingly, can aestivate or traverse terrestrial habitat in response to seasonal changes in freshwater habitat availability. These attributes suggest that snakehead fishes may possess high dispersal potential, irrespective of the terrestrial barriers that would otherwise constrain the distribution of most freshwater fishes. A number of biogeographical hypotheses have been developed to account for the modern distributions of snakehead fishes across two continents, including ancient vicariance during Gondwanan break-up, or recent colonisation tracking the formation of suitable climatic conditions. Taxonomic uncertainty also surrounds some members of the Channa genus, as geographical distributions for some taxa across southern and Southeast (SE) Asia are very large, and in one case is highly disjunct. The current study adopted a molecular genetics approach to gain an understanding of the evolution of this group of fishes, and in particular how the phylogeography of two Asian species may have been influenced by contemporary versus historical levels of dispersal and vicariance. First, a molecular phylogeny was constructed based on multiple DNA loci and calibrated with fossil evidence to provide a dated chronology of divergence events among extant species, and also within species with widespread geographical distributions. The data provide strong evidence that trans-continental distribution of the Channidae arose as a result of dispersal out of Asia and into Africa in the mid–Eocene. Among Asian Channa, deep divergence among lineages indicates that the Oligocene-Miocene boundary was a time of significant species radiation, potentially associated with historical changes in climate and drainage geomorphology. Mid-Miocene divergence among lineages suggests that a taxonomic revision is warranted for two taxa. Deep intra-specific divergence (~8Mya) was also detected between C. striata lineages that occur sympatrically in the Mekong River Basin. The study then examined the phylogeography and population structure of two major taxa, Channa striata (the chevron snakehead) and the C. micropeltes (the giant snakehead), across SE Asia. Species specific microsatellite loci were developed and used in addition to a mitochondrial DNA marker (Cyt b) to screen neutral genetic variation within and among wild populations. C. striata individuals were sampled across SE Asia (n=988), with the major focus being the Mekong Basin, which is the largest drainage basin in the region. The distributions of two divergent lineages were identified and admixture analysis showed that where they co-occur they are interbreeding, indicating that after long periods of evolution in isolation, divergence has not resulted in reproductive isolation. One lineage is predominantly confined to upland areas of northern Lao PDR to the north of the Khorat Plateau, while the other, which is more closely related to individuals from southern India, has a widespread distribution across mainland SE Asian and Sumatra. The phylogeographical pattern recovered is associated with past river networks, and high diversity and divergence among all populations sampled reveal that contemporary dispersal is very low for this taxon, even where populations occur in contiguous freshwater habitats. C. micropeltes (n=280) were also sampled from across the Mekong River Basin, focusing on the lower basin where it constitutes an important wild fishery resource. In comparison with C. striata, allelic diversity and genetic divergence among populations were extremely low, suggesting very recent colonisation of the greater Mekong region. Populations were significantly structured into at least three discrete populations in the lower Mekong. Results of this study have implications for establishing effective conservation plans for managing both species, that represent economically important wild fishery resources for the region. For C. micropeltes, it is likely that a single fisheries stock in the Tonle Sap Great Lake is being exploited by multiple fisheries operations, and future management initiatives for this species in this region will need to account for this. For C. striata, conservation of natural levels of genetic variation will require management initiatives designed to promote population persistence at very localised spatial scales, as the high level of population structuring uncovered for this species indicates that significant unique diversity is present at this fine spatial scale.

The ecology of Bactrocera tryoni (Froggatt) (Diptera: Tephritdae) : what do we know to assist pest management?

The distribution, systematics and ecology of Bactrocera tryoni, the Queensland fruit fly are reviewed. Bactrocera tryoni is a member of the B. tryoni complex of species, which currently includes four named species, viz. B. tryoni s.s., B. neohumeralis, B. melas and B. aquilonis. The species status of B. melas and B. aquilonis are unclear (they may be junior synonyms of B. tryoni) and their validity, or otherwise, needs to be confirmed as a matter of urgency. While Queensland fruit fly is regarded as a tropical species, it cannot be assumed that its distribution will spread further south under climate change scenarios. Increasing aridity and hot dry summers, as well as more complex, indirect interactions resulting from elevated CO2, make predicting the future distribution and abundance of B. tryoni difficult. The ecology of B. tryoni is reviewed with respect to current control approaches (with the exception of Sterile Insect Technique which is covered in a companion paper). We conclude that there are major gaps in the knowledge required to implement most non-insecticide based management approaches. Priority areas for future research include host plant interactions, protein and cue-lure foraging and use, spatial dynamics, development of new monitoring tools, investigating the use of natural enemies and better integration of fruit flies into general horticultural IPM systems.

Ecology and behavior of first instar larval Lepidoptera

Neonate Lepidoptera are confronted with the daunting task of establishing themselves on a food plant. The factors relevant to this process need to be considered at spatial and temporal scales relevant to the larva and not the investigator. Neonates have to cope with an array of plant surface characters as well as internal characters once the integument is ruptured. These characters, as well as microclimatic conditions, vary within and between plant modules and interact with larval feeding requirements, strongly affecting movement behavior, which may be extensive even for such small organisms. In addition to these factors, there is an array of predators, pathogens, and parasitoids with which first instars must contend. Not surprisingly, mortality in neonates is high but can vary widely. Experimental and manipulative studies, as well as detailed observations of the animal, are vital if the subtle interaction of factors responsible for this high and variable mortality are to be understood. These studies are essential for an understanding of theories linking female oviposition behavior with larval survival, plant defense theory, and population dynamics, as well as modern crop resistance breeding programs.

Ureaplasma parvum and ureaplasma urealyticum detected in semen after washing prior to assisted reproductive technology procedures

Objective: This study investigated: (i) the prevalence of ureaplasmas in semen and washed semen and (ii) the effect of ureaplasmas on semen andrology parameters. Design: Prospective study. Setting: IVF unit -private hospital, Brisbane, Australia. Patient(s): Three hundred and forty three men participating in an assisted reproductive technology (ART) treatment cycle. Intervention(s): Semen and washed semen tested by culture, PCR assays and indirect immunofluorescent antibody assays. Statistical differences were determined by a t-test, Wilcoxon or Pearson’s Chi- square test where appropriate. Main Outcome Measure(s): The prevalence of ureaplasmas in semen and washed semen and the effect of these microorganisms on semen andrology parameters. Result(s): Ureaplasmas were detected in 73/343 (22%) semen samples and 29/343 (8.5%) washed semen samples. Ureaplasmas adherent to the surface of spermatozoa were demonstrated by indirect immunofluorescent antibody testing. U. parvum serovar 6 (36.6%) and U. urealyticum (30%) were the most prevalent isolates in washed semen. A comparison of the semen andrology parameters of washed semen ureaplasma positive and negative groups demonstrated a lower proportion of non-motile sperm in the washed semen ureaplasma positive group. Conclusion(s): Ureaplasmas are not always removed from semen by a standard ART washing procedure and can remain adherent to the surface of spermatozoa.

Partial protection against chlamydial reproductive tract infection by a recombinant major outer membrane protein/CpG/cholera toxin intranasal vaccine in the guinea pig Chlamydia cavaie model

Chlamydia trachomatis is a major cause of sexually transmitted diseases worldwide. There currently is no vaccine to protect against chlamydial infection of the female reproductive tract. Vaccine development has predominantly involved using the murine model, however infection of female guinea pigs with Chlamydia caviae more closely resembles chlamydial infection of the human female reproductive tract, and presents a better model to assess potential human chlamydial vaccines. We immunised female guinea pigs intranasally with recombinant major outer membrane protein (r-MOMP) combined with CpG-10109 and cholera toxin adjuvants. Both systemic and mucosal immune responses were elicited in immunised animals. MOMP-specific IgG and IgA were present in the vaginal mucosae, and high levels of MOMP-specific IgG were detected in the serum of immunised animals. Antibodies from the vaginal mucosae were also shown to be capable of neutralising C. caviae in vitro. Following immunisation, animals were challenged intravaginally with a live C. caviae infection of 102 inclusion forming units. We observed a decrease in duration of infection and a significant (p<0.025) reduction in infection load in r-MOMP immunised animals, compared to animals immunised with adjuvant only. Importantly, we also observed a marked reduction in upper reproductive tract (URT) pathology in r-MOMP immunised animals. Intranasal immunisation of female guinea pigs with r-MOMP was able to provide partial protection against C. caviae infection, not only by reducing chlamydial burden but also URT pathology. This data demonstrates the value of using the guinea pig model to evaluate potential chlamydial vaccines for protection against infection and disease pathology caused by C. trachomatis in the female reproductive tract.

Transport of IgG across the blood-luminal barrier of the male reproductive tract of the rat and the effect of estradiol administration on reabsorption of fluid and IgG by the epididymal ducts

In rats immunized systemically with tetanus toxoid the concentration of specific anti-tetanus-toxoid-specific IgG in fluid from the rete testis and cauda epididymidis were respectively 0.6% and 1.4% the concentration in blood serum. The extratesticular duct system reabsorbed 97% of the IgG and 99% of the fluid leaving the rete, but estradiol administration affected the site of reabsorption. In untreated rats, the ductuli efferentes reabsorbed 94% of the IgG and 96% of the fluid leaving the rete, whereas estradiol-treated rats reabsorbed 83% of the IgG and 86% of the fluid, and the ductus epididymidis fully compensated for these different effects of estradiol on the ductuli efferentes. The concentrations of IgG in secretions of the seminal vesicles and prostate gland were lower (0.1% and 0.3% respectively of the titers in blood serum) than in fluids from the extratesticular ducts, and were not affected by the administration of estradiol. RT-PCR showed that Fcgrt (neonatal Fc receptor, also known as FcRn) is expressed in the reproductive ducts, where IgG is probably transported across epithelium, being particularly strong in the ductuli efferentes (where most IgG was reabsorbed) and distal caput epididymidis. It is concluded that IgG enters the rete testis and is concentrated only 2.5-fold along the extratesticular duct system, unlike spermatozoa, which are concentrated 95-fold. Further, the ductus epididymidis can recognize and compensate for changes in function of the ductuli efferentes.

The Bayesian conditional independence model for measurement error: applications in ecology

The measurement error model is a well established statistical method for regression problems in medical sciences, although rarely used in ecological studies. While the situations in which it is appropriate may be less common in ecology, there are instances in which there may be benefits in its use for prediction and estimation of parameters of interest. We have chosen to explore this topic using a conditional independence model in a Bayesian framework using a Gibbs sampler, as this gives a great deal of flexibility, allowing us to analyse a number of different models without losing generality. Using simulations and two examples, we show how the conditional independence model can be used in ecology, and when it is appropriate.