106 resultados para MATURITY


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Pittosporum undulatum Vent. (Sweet Pittosporum) is a densely foliaged tall shrub or small tree, native to the wet forests of south east Australia, This species now functions as a serious environmental weed in a range of habitats in Australia and on other continents and islands throughout the temperate, sub-tropical and tropical zones. This study investigated some of the ecological causes and consequences of P. undulatum invasion across a range of habitat types in south east Australia. Key aspects of P. undulatum biology and ecology investigated in the current study include; patterns of morphological variation across the range of habitats occupied (as a measure of the species’ plasticity), dispersal ecology and seed germinability, population structure and spatial pattern, community relationships and the ecological impacts of invasion. Phenotypic plasticity is considerable in P. undulatum. No clear patterns of geographic variation emerged from a study of leaf morphological attributes across the current range of this species on mainland south east Australia. The pattern of morphological variation is particularly complex in Victoria, where the invasion of this species is most advanced. The species’ adaptability to a range of environments and environmental conditions will likely promote further range expansion. The abundant winter fruit crop produced by functionally female P. undulatum plants attracts a suite of generalist opportunistic frugivores, which feed on P. undulatum fruits and seeds at various stages of fruit dehiscence, thereby enhancing dispersal opportunities for this species. P. undulatum seed collected from natural and invasive populations, at two stages of fruit maturity and from the scats and pellets of dispersal agents, displayed high germinability. European Blackbirds and Pied Currawongs are implicated as the main avian dispersal agents of P undulatum in south east Australia. The broader ecological implications of developing relationships between invasive fleshy-fruited bird-dispersed plant species and adaptive frugivores are likely to be considerable. The distribution of P. undulatutn seedlings was significantly negatively correlated with adult conspecifics and significantly positively correlated with trees and shrubs of other genera. This pattern reflects the importance of both firugivorous dispersal agents and the species’ germination and establishment requirements, in shaping the contagious distribution pattern typical of this species. These analyses suggest that recruitment opportunities for conspecific seedlings are limited beneath the canopy of adult conspecifics. Densities of P. undulatum were on average, 2.7 times higher in invaded populations, compared to the natural populations sampled. A male-bias was evident in all populations and no relationships between reproductive activity and the density of seedlings and juveniles were evident. Invading populations of P. undulatum impose substantial changes on ecosystem-level properties and functions. Mean species richness and cover-abundance declined notably once P. undulatum cover-abundance exceeded 20% at the invaded sites and 60% at the natural sites sampled. The natural communities sampled displayed comparatively greater resilience to the competitive effects of P. undulatum, but community attributes were affected at high densities and cover-abundance of this species. The cover-abundance of herbs and grasses declined most substantially with increasing P. undulatum at invaded sites, whereas, at the natural sites sampled, the species’ structural analogues appeared to be most affected by increasing P. undulatum cover-abundance. This study has demonstrated that the ecological consequences of P. undulatum population expansion are substantial and contribute to changes in the composition and successional trajectory of affected communities. These processes ultimately lead to the loss and simplification of biodiversity values and the homogenisation of affected habitats. P. undulatum has the potential to emerge as one of south east Australia's most serious environmental weed species.

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The population dynamics of the infaunal bivalve Soletellina alba was investigated at three sites situated within close proximity to the mouth of the Hopkins River estuary. The initial study design was planned to examine the importance of winter flooding to the persistence of this bivalve mollusc within the Hopkins estuary, since mass mortalities have been observed during previous years coincident with periods of winter flooding. Unfortunately, the climatic conditions experienced during this study were atypical compared to the long-term average, so detailed sampling was limited to two, unanticipated, non-flood years rather than two, highly anticipated, flood years. This hampered my ability to conduct complete tests of the importance of winter flooding. Patterns of river discharge and the frequency and duration of mouth opening and closing differed greatly from that expected. Unexpectedly, periods of mouth closure were not always associated with periods of minimal river discharge; low salinities were another unexpected result during an extended period of mouth closure during 1998. As expected, salinities varied considerably with increasing water depth when the estuary mouth was open. Mouth closure lead to salinities becoming more uniform between water depths but hypoxic and anoxic conditions became evident via stratification in the water column at 1 m below the Australian Height Datum (AHD). Other than trends associated with increased water depth, significant variation was not evident between measurements of salinity taken from three sites within close proximity of the estuary mouth (approximately 500 m), or during changes in tide. The most pertinent anomaly was the absence of winter flooding. The distribution and abundance of juvenile and adult S. alba was variable across all Dates, Sites and Channel elevations (i.e. water depths) sampled during this study. An experimental test comparing the recruitment of juveniles at different channel elevations and in sediments of varying particle size was conducted during an exceptionally successful period of recruitment during 1999. The results of these tests showed that recruitment was greatest at the shallowest channel elevation used, and there was little evidence that sediment particle size influenced recruitment. In contrast to 1999, recruitment during 1997 or 1998 was extremely poor. Growth rates were monitored using tagged individuals held in caged and uncaged plots, which revealed that growth was highly variable among individuals, but not between Sites. These tests also revealed that growth was negligible during the colder, winter months, and that the fastest growing individuals were capable of growing 0.2 mm/day. Mixed results were obtained for tests of potential cage artifacts and the influence of handling. Caging and differing amounts of handling did not appear to influence growth, but there was evidence that cages and handling influenced bivalve condition and number of mortalities. These direct tests appeared to be the most appropriate method for determining growth rates of this species, since attempts to analyse length-frequency data were made difficult by the apparent convergence of cohorts, and shell aging is difficult due to the thin, fragile nature of the shell. As expected, mass mortalities were observed during the flood of 1996, but not during the two non-flood years of 1997 and 1998. There were, however, some considerable declines in abundances at some channel elevations during the two non-flood years. However, these declines were attributable to the complete disappearance of individuals, rather than the sudden presence of numerous, recently dead individuals that typify observed declines during winter flooding. The complete disappearance of individuals suggest that S. alba may be capable of post-settlement emigration, or that they were consumed by an unknown predator. Salinity tolerance tests showed that bivalves exposed to low salinities (≤6 ppt), exhibited poorer condition and took longer to re-burrow into sediments than those exposed to greater salinities (≥14 ppt), while death of bivalves exposed to salinities ≤1 ppt occurred after 8 days of exposure. These tests provide evidence that low salinities are probably the principal cause of mass mortalities during winter flooding, although the interaction between salinity, temperature and turbidity also deserve consideration. The results of this study indicate that certain aspects of winter flooding, especially salinity, are responsible for the mass mortalities of S. alba rather than the result of a short-lived life history. I hypothesise that the survival of very young juveniles (between 0.5 and 1 mm shell length) and rapid growth rates are important features of the life history of S. alba that explain its successful persistence within the Hopkins River estuary. The rapid rates of growth suggest that it may be possible for juveniles that survive winter flooding to grow, reach sexual maturity, and reproduce before the onset of the next flood event. Unfortunately, the increased survivorship of juveniles during periods of winter flooding was not demonstrated by this study because of the absence of winter flooding and also relatively poor recruitment. It is highly likely that this species is capable of completing it entire life cycle within the estuary since the absence of other nearby populations, together with periods of mouth closure, are likely to greatly limit the potential contribution made by larvae entering from the surrounding marine environment. This study has added considerably to our knowledge of how infauna cope with life in the intermittently closing estuaries that typify semi-arid coastlines in the Southern Hemisphere.

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The Australian Early Development Index (AEDI) is a population measure of child development. The AEDI measures Language and Cognitive Development, Social Competence, Emotional Maturity, Physical Health and Wellbeing, and Communication Skills and General Knowledge. In Australia these data are collected by teachers for children in their first full time year of schooling. The aim of this paper is to aid people's understanding and interpretation of population measures such as the AEDI. With a greater awareness of the merits and complexities of population data clinicians and allied health professionals can play a vital role in aiding communities and policy makers to interpret and act upon the data in an intelligent way. This paper is primarily descriptive providing background information on the development and use of the instrument utilizing one of the 5 developmental domains (Language and Cognitive Development) as an example. The results show a complex relationship between children residing in differing socio-economic regions, children with English as their primary or secondary language and children who are able or not able to effectively communicate in English.

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Challenges the existing normal science in project management with its limitations of high certainty in scope definition and develops a contingency based model for project / program management (PROJAM). The PROJAM concept is theoretically supported through the identification of eight inter related aspects - uncertainty, maturity, stakeholders, pareto, reward, transparency, partnering, and program management. The ideas presented represent a radical change to the eisting project management body of knowledge and expand the scope of project management to deal with complex projects / programs including organisational change, core function outsourcing (asset management) and IT hardware and software outsourcing.

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Osmiophilic bodies are membrane-bound vesicles, found predominantly in Plasmodium female gametocytes, that become progressively more abundant as the gametocyte reaches full maturity. These vesicles lie beneath the subpellicular membrane of the gametocyte, and the release of their contents into the parasitophorous vacuole has been postulated to aid in the escape of gametocytes from the erythrocyte after ingestion by the mosquito. Currently, the only protein known to be associated with osmiophilic bodies in Plasmodium falciparum is Pfg377, a gametocyte-specific protein expressed at the onset of osmiophilic body development. Here we show by targeted gene disruption that Pfg377 plays a fundamental role in the formation of these organelles, and that female gametocytes lacking the full complement of osmiophilic bodies are significantly less efficient both in vitro and in vivo in their emergence from the erythrocytes upon induction of gametogenesis, a process whose timing is critical for fertilization with the short-lived male gamete. This reduced efficiency of emergence explains the significant defect in oocyst formation in mosquitoes fed blood meals containing Pfg377-negative gametocytes, resulting in an almost complete blockade of infection.

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This study provided initial evidence that extract derived from the cartilage of two commercially available Australian shark species, may potentially, be effective in the inhibition of tumour growth, whilst also showing that the species and maturity level, but not the gender of the shark, influenced the amount of extract obtained.

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This study examined the development of declarative and procedural memory longitudinally in primary school-aged children. At present, although there is a general consensus that age-related improvements during this period can be found for declarative memory, there are conflicting data on the developmental trajectory of the procedural memory system. At Time 1 children aged around 5 years were presented with measures of declarative and procedural memory. The tasks were then administered 12 months later. Performance on the declarative memory task was found to improve at a faster rate in comparison to the procedural memory task. The findings of the study support the view that multiple memory systems reach functional maturity at different points in development.

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Recovery of the Australian fur seal (Arctocephalus pusillus doriferus) population has been slower than that of other fur seals, perhaps due to nutritional constraints on fecundity. However, the population doubled in recent decades, suggesting that reproductive rates may have changed. Pregnancy rates and birthrates were estimated and the influences of maternal age, size, condition, and lactation status were investigated over 3 consecutive breeding seasons (2003–2005). Mid-gestation pregnancy rate, estimated from plasma progesterone concentrations, was 84% ± 3% (mean ± SE) and was negatively influenced only by age (P< 0.001). Birthrate, estimated from observations of females with newborn offspring during the breeding season, was 53% 6 3% (mean ± SE) and was influenced negatively by lactation status (P = 0.035). The difference between pregnancy rates and birthrates suggests that a high degree of late-gestation abortion occurs, especially in younger females. Lactation status was not influenced by any variables, and the high rate (86% ± 2%; mean ± SE) suggests that many offspring are suckled beyond the typical weaning period. Although relationships between reproductive rates and body condition were not found, the results are consistent with a nutritional stress hypothesis. The recent increase in population growth is not due to increased fecundity, which remains low compared to other otariids. Paradoxically, high pregnancy rates were observed in young females (3 years), suggesting that rapid maturity is adaptive for benthic foragers.

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Organisations need to rely on leadership, information support and human capital in order to ensure a knowledge advantage over their competitors. Knowledge management (KM) provides organisations with sustainable competitive advantage, because it becomes extremely difficult for an organisation to cut expenditure and increase revenue by simply reengineering its business model. Project delivery and success has been traditionally viewed and measured as management of a three-legged stool, with the legs defined as cost, schedule and quality. However, KM can be linked to success by organisations becoming more effective as well as being more efficient.

This paper uses a KM framework, the Knowledge Advantage (K-Adv), developed initially for use by construction organisations. It assesses the impact of leadership and its supporting information communication technology infrastructure on the ability of people (by effectively creating, sharing, disseminating and using knowledge) to facilitate sustainable competitive advantage.

A case study that is presented is based upon the experience of a leading construction company using an Enterprise Resources Planning (ERP) system to demonstrate the effectiveness of KM from a cost management business unit perspective. Results are evaluated using a capability maturity model (CMM) - that forms the core of the K-Adv tool - to help improve processes that meet the needs of the organisation operating in a highly dynamic business environment. The case study is part of a broader doctoral research project that uses action learning to facilitate and measure ERP improvement.

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Purpose – Competitive advantage can be gained in several ways including gaining a knowledge advantage (K-Adv). This paper sets out to report on the first stage of broad study to assess the effectiveness of implementing an enterprise resource planning system (ERP) from a knowledge management (KM) perspective.

Design/methodology/approach – The study used a survey of a small but representative group to gain feedback in their experience of using the ERP system. Results are evaluated using a KM framework, the knowledge advantage (K-Adv) capability maturity model (CMM) tool that was initially developed for use by construction organisations to assess the impact of leadership and its supporting ICT infrastructure on the ability of people (by effectively creating, sharing, disseminating and using knowledge) operating in a highly dynamic business environment.

Findings – The K-Adv framework analysis for the study indicates that the ERP system was seen as a useful tool for cost management and that its deployment effectiveness is mainly dependent on human-to-human knowledge transfer about how to make the ERP system work. Also, how leaders in organisations facilitate and support people is a critical enabler of the ERP system deployment. The K-Adv CMM tool was useful in making sense of the degree of organisational maturity from a KM perspective.

Practical implications – The findings first highlight the usefulness of focusing on people-support in using the ERP adoption in this organisation's context and, second, they illustrate how a CMM tool like the K-Adv can be used to evaluate KM practices.

Originality/value – The likely effectiveness of use of an ERP is well-known. However, the originality of the paper is twofold. First, it explains effective ERP application drivers and inhibitors from a KM perspective. Second, it tests and adapts a tool that helps evaluate KM effectiveness and assists better understanding of how these practices are enacted from a cost management business unit perspective.

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Regional industry clusters have been promoted for several years as effective mechanisms to assist firms become more innovative and more competitive. But do they really achieve this goal, and more importantly, just how should an assessment of cluster performance in supporting and facilitating innovation within its members, be undertaken? In this paper we report on a study of a regional IT cluster in Western Sydney, Australia, develop some criteria for assessing the innovation facilitation performance of industry clusters, and discuss the cluster in relation to these criteria. We suggest that engagement with a cluster may enhance the innovation capacity of a firm, and the type of required innovation support varies significantly with the maturity and absorptive capacity of individual firms.

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While Australian firms have generally recognised the value of continuous improvement (CI) in improving performance, many have yet to develop systems to ensure that the efforts of the CI program are focussed on issues of strategic importance to the company. In fact, as recognised in operations management generally, CI activities can have a significant impact on the development of strategy as well as its implementation. The research reported here uses a CI mapping methodology to chart the relationship between CI and strategy in small- to medium-sized manufacturers. Analysis of the link between the firms’ strategies and CI programs indicates that most firms involved in the study made little attempt to link the two and some appear to be unaware of any need to do so. However, such findings seem to be dependent on company size, the maturity of the CI program and the competitive position of the firm. The paper also includes an examination of the role of operations and shopfloor CI in company strategy, particularly as related to SMEs.

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Increasingly project teams on international mega projects are composed of multiple partners from different countries forming joint ventures to achieve a higher level of strategic flexibility. Establishing and maintaining local business networks are critical to ensure the success of exporting firms. Firms who achieve competitive advantage in international markets and long term economic sustainability constantly adapt their business practices to achieve client satisfaction by a combination of self, market and project needs assessment. Successful firms ultimately achieve this in local markets but in international market this is intensified with the complexity of barriers grounded in cross-cultural contexts. The need for flexibility, adaptability and continual reassessment is enhanced as the market evolves in various localities. Reflexivity theory was used to develop a conceptual model to explain the way in which firms develop awareness, responsiveness and adaptability for long term success in diverse international markets. This paper summarizes the initial Australian study which developed the model grounded in empirical observations of design construction firms working on projects in developing countries and a second study of Malaysian firms which validated the model. The aim of this study was to develop a performance measurement framework for capabilities assessment of international collaborative partnerships. The study explored the joint venture partnerships between Australian and Malaysian property and construction professionals. Four Malaysian organizations were examined as case studies and two key activities of design management and knowledge management were analyzed in relation to social, cultural and intellectual capital transformation within the Reflexivity Capability Maturity Assessment Framework.

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Egg-laying hormone (ELH) is a neuropeptide hormone that stimulates ovulation of gastropods, including Aplysia californica and Lymnaea stagnalis. Other neuropeptides, gonadotropin releasing hormones (GnRHs), also play important roles in controlling reproduction in both vertebrates and invertebrates. In the current study, the effects of abalone ELH (aELH) and several GnRHs on somatic growth, sex differentiation, gonad maturation, and spawning of Haliotis asinina were investigated in 3 experiments. In experiment 1, groups of 4-mo-old juveniles (11.8 ±  0.03 mm shell length (SL) and 0.33 ± 0.04 g body weight (BW)) were injected with aELH and GnRHs, including buserelin (mammalian GnRH analogue), octopus GnRH (octGnRH), and tunicate GnRH-I (tGnRH-I), at doses of 20 ng/g BW and 200 ng/g BW. The aELH induced early sex differentiation with a bias toward females, but with normal somatic growth, whereas the different isoforms of GnRH had no effect on sexual differentiation or somatic growth. In experiment 2, groups of 1-y-old-abalone (SL, 4.04 ± 0.02 cm; BW, 20.15 ± 0.25 g) were injected with aELH and the 3 isoforms of GnRH including buserelin, octGnRH, and lamprey GnRH (1GnRH-I) at doses of 500 ng/g BW and 1,000 ng/g BW, and all produced stimulatory effects. For each peptide treatment, the gonads reached full maturation within 5- 6 wk and spawning occurred, whereas control groups took 8 wk to reach maturity. In experiment 3, injections of ripe abalone with aELH stimulated spawning of both sexes in a dose-dependent manner. Buserelin had a lesser effect on inducing spawning, and octGnRH had no apparent effect. The gametes released from induced spawnings by aELH and GnRH showed normal fertilization and development of larvae. Altogether, these findings provide further knowledge on manipulating abalone reproduction, which is important in improving abalone aquaculture.

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This research identifies how the IT function can create agility in existing information systems. Agility is the capability to quickly sense and respond to environmental perturbations. We contrasted perspectives on agility from a widely used industry framework and that of the IS research literature. Beer’s Viable System Model was a useful meta-level theory to house agility elements from IS research and it introduced cybernetic principles to identify the processes required of the IT function. Indeed, our surveys of 70 organizations confirmed that the applied theory better correlates with reported agility than does existing industry best practice.

The research conducted two quantitative surveys to test the applied theory. The first survey mailed a Likert-type questionnaire to the clients of an Australian IT consultancy. The second survey invited international members of professional interest groups to complete a web-based questionnaire. The responses from the surveys were analyzed using partial-least-squares modeling. The data analysis positively correlated the maturity of IT function processes prescribed by the VSM and the likelihood of agility in existing information systems. We claim our findings generalize to other large organizations in OECD member countries.

The research offers an agility-capability model of the IT function to explain and predict agility in existing information systems. A further contribution is to improve industry ‘best practice’ frameworks by prescribing processes of the IT function to develop in maturity.