990 resultados para MATURITY


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This study aimed at demonstrating the asymmetry in volume between the dominant and nondominant upper limbs in tennis players, controlled for maturity status. Upper limb volumes on both sides were calculated in 72 tennis players and 84 control subjects, using the truncated cone method. The participants’ maturity status was determined using the predicted age at peak height velocity (PHV). The results showed significant larger side-to-side asymmetry in volume in tennis groups than
in control groups. These findings suggested that, even before PHV, specific-sport adaptations occurred in the dominant upper limb in tennis players.

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Abstract. In applying a quantitative approach to the reproduction of Trygonoptera imitata, the present study contributes to understanding the wide diversity in the reproductive biology of the family Urolophidae and provides insights to help determine phylogenetic relationships. This localised species is taken as bycatch in several inshore fisheries and potentially impacted by a range of other anthropogenic pressures, including introduced species, particularly in shallow-water pupping areas.T. imitata can be characterised as a species of comparatively lowmatrotrophic histotrophy with an extended period of relatively large eggs in utero (5–8 months) followed by rapid growth of the embryos (4–6 months). The reproductive cycle is annual with parturition occurring during late-February–April, followed immediately by ovulation. Mean size-at-birth is ~225mm total length and there is a ~1000% gain in mean wet mass from egg (15 g) to full-term embryo in utero (150 g), the lowest reported for any viviparous batoid. Litter size increases with maternal length, reaching a maximum of seven, and sex ratio of embryos is 1 : 1. Maximum length and estimates of the maturity–ogive parameters l50 and l95 are similar for females and males.

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Pre- and early puberty seem to be the most opportune times for exercise to  improve bone strength in girls, but few studies have addressed this issue in boys. This study investigated the site-, surface-, and maturity-specific exercise-induced changes in bone mass and geometry in young boys. The osteogenic effects of loading were analyzed by comparing the playing and nonplaying humeri of 43 male pre-, peri-, and postpubertal competitive tennis players 10-19 yr of age. Total bone area, medullary area, and cortical area were determined at the mid (40-50%) and distal humerus (60-70%) of both arms using MRI. Humeral bone mass (BMC) was derived from a whole body DXA scan. In prepubertal boys, BMC was 17% greater in the playing compared with nonplaying arm (p < 0.001), which was accompanied by a 12-21% greater cortical area, because of greater periosteal expansion than medullary expansion at the midhumerus and periosteal expansion associated with medullary contraction at the distal humerus. Compared with prepuberty, the side-to-side differences in BMC (27%) and cortical area (20-33%) were greater in peripuberty (p < 0.01). No differences were found between peri- and postpuberty despite longer playing history in the postpubertal players.The osteogenic response to loading was greater in peri- compared with prepubertal boys, which is in contrast with our previous findings in girls and may be caused by differences in training history. This suggests that the window of opportunity to improve bone mass and size through exercise may be longer in boys than in girls.

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Occurrence patterns of parasitic plants are constrained by the distribution of suitable hosts and movement patterns of seed vectors and, accordingly, represent a simplified system to study many aspects of spatial ecology and determinants of distribution. Previous work has focused on the aerially hemiparasitic mistletoes, and it is unclear whether root parasites are affected by similar factors. Here, we evaluate spatial patterns in the root parasitic Santalum lanceolatum in an arid shrubland in north-western New South Wales, central Australia. In this region, the principal host is a long-lived nitrogen fixing shrub Acacia tetragonophylla closely associated with ephemeral creek-lines. The location of 765 individuals of both species was mapped along a 250-m section of creek-line using a total survey station, and occurrence patterns of the root parasite related to host distribution and landscape context. We used Ripley's K-function and the O-ring statistic to determine whether the distribution of S. lanceolatum was random, aggregated or regular; the spatial scales at which these patterns occurred; and to quantify any spatial associations between the parasite and its host, A. tetragonophylla. While acacias were closely associated with the creek-line, S. lanceolatum plants were more tightly clustered, displaying significant clustering at two spatial scales (1.2 m and 8.8 m). We suggest that host quality may act as an important constraint, with only those acacias growing in or near the creek-line being physiologically capable of supporting a parasite to maturity. Insights gained from spatial analysis are used to guide ongoing research in this system, and highlight the utility of the O-ring statistic for understanding patterns of distribution affected by multiple processes operating at critical scales.

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This paper discusses the economic transition and the property market emergence in transition economies. It compares the Chinese property market with the Polish market. It preliminarily examines market emergence and maturity in the context of economic transition, comparing the transitions with the emphasis placed on commercial property markets especially their formation and behaviour. Supply and demand for commercial space in China and Poland are also contrasted. As commercial property market behaviour is somewhat driven by market structure formation process and the business cycle, the transition has provided a “common ground” that enables similarities between the property markets in China and Poland. The challenge for state intervention is mainly due to the agency problem which is also a problem in mature markets; it appears that transitional economies do share common features in their emerging property markets. This paper suggests state intervention in market formation and emergence is necessary and essential. However the actual formation and behaviour of property markets have some distinctive characteristics. Value or implication of the study include: knowing the stage of market emergence is essential for making investment decisions, especially when identifying markets with varying backgrounds. This paper is also relevant to policy-makers in the process of facilitating transitions in emerging markets.

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Approximately 70% of Australian Teaching and Learning Centres have been restructured and/or have undergone leadership changes in the last three years. The volatility of this environment reflects the number of significant challenges faced by Teaching and Learning Centres. In determining what makes Centres successful, the issues that are likely to impact on their ability to succeed were examined. It emerged that a myriad of factors influence whether or not a Centre was recognised as being an integral and valued part of the university’s teaching and learning community – a hallmark of having reached maturity. This paper identifies four factors as being critical to the ability of Centres to succeed, noting that a combination of other factors, appropriate to each unique context, must also be in place in order for Centres to maximise their value.

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The aim of this thesis is to establish, from a historical and religious perspective, that the Presbyterian ethos and environment in which John Buchan was reared was the predominating influence in the writing of his novels. Presbyterianism was not the only influence on Buchan that determined the character of his stories. Buchan was by temperament a romantic, and this had considerable influence on his literature. His novels are romances, peopled by romantic figures who pursue romantic adventures. There are the signs of Buchan's romantic nature in the contents of the novels: creative imagination, sensitivity to nature, and expectations of the intrusion of other worlds, with destiny-determining events to follow. But Buchan had also an acquired classicism. His studies at Glasgow and Oxford Universities brought him in touch with a whole range of the master-pieces of classical literature, especially the works of Plato and Virgil. This discipline gave him clarity and conciseness in style, and balanced the romantic element in him, keeping his work within the bounds of reason. At the heart of Buchan's life and work, however, was his deeply religious nature and this, while influenced by romanticism and classicism, was the dominant force behind his work. Buchan did not accept in its entirety the Presbyterian doctrine conveyed to him by his father and his Church. He was moderate by temperament and shrank from excesses in religious matters, and, being a romantic, he shied away from any fixed creeds. He did embrace the fundamentals of Christianity, however, which he learned from his father and his Church, even if he did put aside the Rev. John's orthodox Calvinism. The basic Christianity which underlies all Buchan's novels has the stamp of Presbyterianism upon it, and that stamp is evident in his characters and their adventures. The expression of Christianity which Buchan embraced was the Christian Platonism of seventeenth century theologians, who taught and preached at Cambridge University, They gave prominence to the place of reason and conscience in man's search for God, They believed that reason and conscience were the ‘candle of the Lord’ which was existed every one. It was their conviction that, if that light was followed, it would lead men and women to God. They were against superstition and fanaticism in religion, against all forms of persecution for religious beliefs, and insisted that God could only be known by renouncing evil and setting oneself to live according to God’s will. This teaching Buchan received, but the stamp of his Presbyterianism was not obliterated. The basic doctrines which arose from his father's Presbyterianism and are to be found in Buchan's novels are as follows: a. the fear (or awe) of God, as life's basic religious attitude; b. the Providence of God as the ultimate determinative force in the outcome of events; c. the reality, malignity and universality of evil which must be forcefully and constantly resisted; d. the dignity of human beings in bearing God's image; e. the conviction that life has meaning and that its ultimate goal, therefore, is a spiritual one - as opposed to the accumulation of wealth, the achieving of recognition from society, and the gaining access to power; f. the necessity of challenge in life for growth and fulfilment, and the importance of fortitude in successfully meeting such challenge; g. the belief that, in the purpose of God, the weak confound the strong. These emphases of Presbyterianism are to be found in all Buchan's novels, to a greater or lesser degree. All his characters are serious people, with a moral purpose in life. Like the pilgrims of the Bible, they seek a country: true fulfilment. This quest becomes more spiritual and more dearly defined as Buchan grows in age and maturity. The progress is to be traced from his early novels, where fulfilment is sought in honour and self-approving competence, as advocated by classicism; to the novels of his middle years, where fulfilment is sought in adventures suggested by romanticism. In his final novel Sick Heart River. Buchan appears to have moved somewhat from his earlier classicism and his romanticism as the road to fulfilment. In this novel, Buchan expresses what, for him, is ultimate fulfilment: a conversion to God that produces self-sacrificing love for others. The terminally-ill Edward Leithen sets out on a romantic adventure that will enable him to die with dignity, and so, in classic style, justify his existence. He has a belief in God, but in a God who is almighty, distant and largely irrelevant to Leithen's life. In the frozen North of Canada, where he expects to find his meagre beliefs in God's absolute power confirmed by the icy majesty of mountain and plain, he finds instead God's mercy and it melts his heart. In a Christ-like way, he brings life to others through his death, believing that, through death, he will find life. There is sufficient evidence to give plausibility to the view that Buchan is describing in Leithen his own pilgrimage. If so, it means that Buchan found his way back to the fundamental experience of the Christian life, conversion, so strongly emphasised in his orthodox Presbyterianism home and Church. However, Buchan reaches this conclusion in a Christian Platonist way, through the natural world, rather than through the more orthodox pathway of Scripture.

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Populations of Dicranoloma billardierei (Brid) Par., D. dicarpum (Nees.) Par., D. menziesii (Tayl.) Par. and D. platycaulon (C. Muell) Dix, from two pockets of cool temperate rainforest within the Yarra Ranges National Park (Cement Creek and Myrtle Loop), were sampled for a period of two years to establish their reproductive biology. The population dynamics within quadrats of D. billardierei, D. menziesii and D. platycaulon at Cement Creek also was investigated over a two year period, through the seasonal recording of shoot loss and/or gain, The four species of Dicranoloma were dioicous and sexually dimorphic, with dwarf males epiphytic on the female plants. Antheridia were initiated before archegonia and required ca, 6 months to reach maturity, compared with 1 to 2 months for archegonia. More archegonia than antheridia occurred per inflorescence and were more variable Fertilization occurred during winter in D. billardierei and summer/ autumn in D. menziesii and D. platycaulon. The duration of the sporophyte cycle of D. menziesii was 12 months, shorter than that of D. billardierei and D. platycaulon which lasted for a period of 18 months to 2 years. In the latter two species an overlap of sporophyte generations occurred. This was particularly pronounced in D. billardierei as sporophytes remained in the swollen venter maturation stage for a period of 6 months. The duration of the sporophyte cycle could not be ascertained as few fruiting stems of D. dicarpum were found. All four species of Dicranoloma regenerated from fragments cultured in the laboratory, and only two of the species showed evidence of production of asexual propagules in the field. Dicranoloma dicarpum was found to produce gemmae, an observation which had not been recorded before, and most of the leaves on stems of D. platycaulon had detached subulas. Shoot loss was minimal in all four species, and when it did occur, (eg D. billardierei) it was attributed to disturbance by animals. Within quadrats there was an increase in shoot density which resulted from the development of innovation(s) and/or side branches rather than from the recruitment of new plants from spores or the regeneration of asexual propagules. The four species of Dicranoloma investigated were robust, perennial mosses and formed an important component of the bryophytes found within the study area. Dicranoloma menziesii was the predominant species establishing on a variety of substrata, particularly as an epiphyte on Nothofagus cunninghamii The other species were more selective in their choice of substratum. Dicranoloma platycaulon was found exclusively on the trunks of myrtle beech and D. billardierei on fallen logs and exposed roots. Dicranoloma dicarpum which was not common, grew as an epiphyte on myrtle beech and on rocks.

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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.