30 resultados para juvenile and mature wood

em Deakin Research Online - Australia


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Social networks are often inferred from spatial associations, but other parameters like acoustic communication are likely to play a central role in within group interactions. However, it is currently difficult to determine which individual initiates vocalizations, or who responds to whom. To this aim, we designed a method that allows analyzing group vocal network while controlling for spatial networks, by positioning each group member in equidistant individual cages and analyzing continuous vocal interactions semi-automatically. We applied this method to two types of zebra finch groups, composed of either two adult females and two juveniles, or four young adults (juveniles from the first groups). Young often co-occur in the same social group as adults but are likely to have a different social role, which may be reflected in their vocal interactions. Therefore, we tested the hypothesis that the social structure of the group influences the parameters of the group vocal network. We found that groups including juveniles presented periods with higher level of activity than groups composed of young adults. Using two types of analyses (Markov analysis and cross-correlation), we showed that juveniles as well as adults were more likely to respond to individuals of their own age-class (i.e. to call one after another, in terms of turn-taking, and within a short time-window, in terms of time delay). When juveniles turned into adulthood, they showed adult characteristics of vocal patterns. Together our results suggest that vocal behavior changes during ontogeny, and individuals are more strongly connected with individuals of the same age-class within acoustic networks.

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The literature suggests that assessment is a powerful tool for influencing student study habits. It is also recognized that there is a tension between traditional forms of assessment and newer forms of assessment that offer a more authentic representation of practice, but are more complex and expensive to administer. The international trend in undergraduate engineering course accreditation to move to demonstration of attainment of graduate attributes poses new challenges in assessment of learning. A case study based on integrating assessment practices across the year levels of an engineering management studies stream in an undergraduate course is presented. Key features of the assessment portfolio include: the use of assessment in the first year as a foundational tool to establish student study habits and skills; the evolution of assessment tasks by the fourth year to reflect the world of professional practice and to allow students to demonstrate their integration of knowledge and skills; the weighting of assessment tasks to indicate the value attached to particular tasks; the structured inclusion of group work; a concern for student and staff workloads; the recognition of student diversity, in particular the needs of off-campus and mature-age students; and the matching of assessment tasks to professional accreditation requirements.

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Studies examining recruitment processes for soft-sediment macroinvertebrate fauna in intermittent estuaries are rare and most studies of active habitat selection have been tested in the laboratory rather than the field. The present field study examined whether recruitment of the infaunal bivalve Soletellina alba was influenced by water depth and sediment particle size in the intermittent Hopkins River estuary, southern Australia. The number of recruits in sediment trays differed between water depths, but active habitat selection was not evident across treatments of varying sediment particle size. The use of sediments with varying particle sizes also provided an opportunity to identify potential discontinuities in body-size distributions of recruits associated with varying habitat architecture. The length (mm) of recruits was converted to the same scale used to express sediment particle size (i.e. phi units: phi = − log2 of sediment particle size). The size of recruits differed across water depths, but did not differ across treatments with fine (phi = 3) versus coarse (phi = 1) sediment, and no relationships were apparent between bivalve size and sediments consisting of varying particle size. These patterns of recruitment do not correspond with the distribution of adult S. alba within the Hopkins River estuary. Previous sampling has shown that abundances of juvenile and adult S. alba are variable across time, site and water depth, but are often greater at the deeper water depth (1.05 m below the Australian Height Datum). However, recruitment during the present study was greatest at the shallower water depth (0.05 m below AHD), and the apparent absence of active habitat selection suggests that the distribution of adults is unlikely to be attributable to differences in recruitment associated with sediments of varying particle size.

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The infaunal bivalve Soletellina alba is susceptible to mass mortalities during annual winter flooding in the Hopkins River Estuary, southern Australia. Periods of low salinity (≤1) are the likely cause of these mass mortality events, which can occur in seasonally-closed estuaries when high winter flows are sufficient to flush all salt water from the estuary. Core samples of S. alba were collected from two water depths across four times and at three sites near the mouth of the estuary. Minimal to zero abundances of large S. alba (>1 mm) were expected to be sampled, particularly at the shallower water depth, during a typical winter flood event. However, the present study occurred during a period of drought, which led to the absence of winter flooding. This absence of winter flooding prevented the occurrence of lethal salinities (i.e. ≤1) in the estuary during this period and a greater number of living S. alba adults were sampled. Abundances of juvenile and adult S. alba were still variable, even in the absence of winter flooding, and reflected an interaction between date, site and water depth. However, no mass mortalities of adults were observed during the drought conditions in contrast to what occurs during typical winter flood events and provides support for the hypothesis that winter flooding is responsible for past mass mortalities.

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Framing the Future is a major staff development initiative of the Australian National Training Authority (ANTA), designed to support the implementation of the National Training Framework (NTF). Since 1997 over 20,000 vocational education and training (VET) practitioners have participated in the program. The program was renamed Reframing the Future in 2001.

This study reports on research conducted on the long-term impacts of projects funded by Framing the Future in 1999 and 2000. John Mitchell and Sarah Wood from John Mitchell & Associates conducted the research from May 2000–May 2001.

Using twenty four case studies and the results of interviews and an extensive survey, the report provides evidence of high-skilled VET practitioners and high-performing VET organisations who ensure that their involvement in Framing the Future projects leads to long-term gains, particularly in support of the implementation of the NTF.

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This cross-sectional study investigated the imaging appearance of the previous termpatellarnext term tendon attachment to the tibia in young male and female tennis players of different ages and pubertal status. Forty-four competitive young players, who had been playing tennis at least for 2 years, were recruited from a tennis school and local tennis clubs. All subjects had bilateral ultrasound imaging of the previous termpatellarnext term tendon attachment to the tibia. Standard anthropometric measurements, pubertal status and injury history were recorded. Ultrasound appearance of the previous termpatellarnext term tendon attachment was categorised into three stages: cartilage attachment, insertional cartilage and mature attachment. Cartilage attachment was more prevalent in boys (32%) and extended further into puberty (until Tanner stage 4) compared to girls (6% and Tanner stage 1). Tendons with Osgood–Schlatter Disease symptoms (n = 3) did not have a cartilage attachment. Imaging appearance commonly seen in young active athletes, consistent with a clinical diagnosis of OSD, was more common in boys and in the pre- and peri-pubertal stages.

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1. Immunological imprinting by maternally derived antibodies has been proposed to have both positive and negative consequences for offspring immunity in early and adult life. However, few studies of maternal effects on immunity have followed individuals past the juvenile stages.

2. Using laboratory Japanese quail, we developed a novel method of directly manipulating yolk antibodies of neonates, and then followed individuals through a series of immune challenges until they were of reproductive age.

3. Our method of directly injecting purified antibodies into the yolk sac of newly hatched chicks successfully elevated the plasma titres of specific anti-KLH IgY in neonates. This allows us to test whether differences in neonatal anti-KLH IgY affect immunity at the juvenile and adult stages of life.

4. We found little evidence for an effect of maternal antibodies on juvenile stage immune response, in contrast to results from previous studies. Adult immune response depended largely on the magnitude of the juvenile immune response regardless of the identity of the antigen in the juvenile immune challenge, and did not depend on neonatal IgY titres. Our results are consistent with a priming effect of early immune experience on adult stage immune responsiveness, but we found no evidence of carryover effects of yolk-derived antibodies on adult immunity.

5. This study employs new methodology for investigation of maternal antibodies and presents results suggesting that further studies of maternal effects on immunity will require careful consideration of the numerous ways maternally derived yolk components can impact the different types of immune response.

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Conventionally, most research and restoration involving in-stream wood focuses on large wood (>0.1 m diameter), excluding any smaller pieces. However, this may neglect a major component of in-stream habitat, as small wood can constitute the majority of pieces, particularly in small streams. The ecological benefit of large wood is well established, but corresponding benefits associated with small wood (0.05-0.1 m diameter) have not been demonstrated. To test the effect of wood dimension on macroinvertebrate community composition, we compared the fauna occupying large wood habitats with that occupying small wood at eight streams in south-eastern Australia. The relationships between wood dimensions and its macroinvertebrate fauna were complex. Community composition did not vary with wood dimension, and no significant correlations were found between other macroinvertebrate attributes (including family richness and evenness) and wood dimension, including diameter. However, analysis of covariance suggested that large wood supported a greater diversity and abundance of macroinvertebrates, indicating that the method of analysis could influence the result. Adjustment for differences in sample dimension using rarefaction determined that these findings were likely to be a result of the surface area and volumes sampled varying with the dimension of the wood. Per unit surface area, and per unit volume, small wood supported a similar number of families to large wood. Thus we conclude that, relative to the available surface area, small and large wood can be equivalent in their contribution to the available habitat in a stream. Therefore, the potential value of small wood as a habitat resource warrants its explicit consideration for inclusion in ecological and rehabilitation studies.

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The Commonwealth Government has the increased participation of under-represented groups to a 20% diversity target for Australian universities. It also has minimum targets of 40% of all Australians (25-34 years) holding a Bachelor’s degree by 2020. These targets are baseline items in a government agenda of improving educational outcomes for Australians and pivotal in addressing skill shortages in industries such as construction. In construction there is a skewing of skill shortages to the higher order or post entry level skills. Demand for higher skilled occupations such as construction managers, outstrips demand for construction trades (DEEWR, 2010). But whilst 41% of the industry have VET qualifications, only 10% possess HE qualifications in construction. Movement between the VET and HE sectors is low: of all construction students qualifying at AQF 4, less than 10% continue on to higher education and less than 1% of VET qualified persons in the construction workforce seek re-entry to university. This paper examines national data in construction education pathways and evaluates, using the DEMO matrix, the enablers in pathways to HE qualifications. The evaluation is based upon survey responses of two cohorts entering higher education from non-traditional pathways- articulating VET students and mature-aged workers. The results indicate that pathway programmes into construction degrees can attract non-traditional cohorts, but elements such as learner engagement, confidence, people-rich resources and collaboration are critical features of successful pathways.

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The expanding scope of practice of paramedics and nurses demands they possess a sophisticated knowledge of bioscience to enable them to think critically and make rational clinical decisions. It is well documented that nursing students struggle with bioscience but there are no studies examining the performance of paramedic students in this crucial subject. In this study, we compared the academic performance of first year nursing, paramedic and nursing/paramedic double degree students in a bioscience subject. Regression analyses were used to identify predictors of academic success. Data revealed a low success rate in bioscience for all three degree programs (63.2, 58.8, and 67.6% respectively) and a strong correlation between academic success in bioscience and non-bioscience subjects (r(2)=0.49). The best predictors of overall academic success were the University Admission Index score and mature entry into the course. Previous study of biology was associated with an increased bioscience and overall GPA but not with non-bioscience grades. Discriminant analysis was used to develop a model that could predict overall academic success with an accuracy of 78.5%. These criteria may be useful during the admission process and for the early identification of students at risk of failure.

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ADAMTS5 (aggrecanase-2), a key metalloprotease mediating cartilage destruction in arthritis, is synthesized as a zymogen, proADAMTS5. We report a detailed characterization of the propeptide excision mechanism and demonstrate that it is a major regulatory step with unusual characteristics. Using furin-deficient cells and a furin inhibitor, we found that proADAMTS5 was processed by proprotein convertases, specifically furin and PC7, but not PC6B. Mutagenesis of three sites containing basic residues within the ADAMTS5 propeptide (RRR46, RRR69 and RRRRR261) suggested that proADAMTS5 processing occurs after Arg261. That furin processing was essential for ADAMTS5 activity was illustrated using the known ADAMTS5 substrate aggrecan, as well as a new substrate, versican, an important regulatory proteoglycan during mammalian development. When compared to other ADAMTS proteases, proADAMTS5 processing has several distinct features. In contrast to ADAMTS1, whose furin processing products were clearly present intracellularly, cleaved ADAMTS5 propeptide and mature ADAMTS5 were found exclusively in the conditioned medium. Despite attempts to enhance detection of intracellular proADAMTS5 processing, such as by immunoprecipitation of total ADAMTS5, overexpression of furin, and secretion blockade by monensin, neither processed ADAMTS5 propeptide nor the mature enzyme were found intracellularly, which was strongly suggestive of extracellular processing. Extracellular ADAMTS5 processing was further supported by activation of proADAMTS5 added exogenously to HEK293 cells stably expressing furin. Unlike proADAMTS9, which is processed by furin at the cell-surface, to which it is bound, ADAMTS5 does not bind the cell-surface. Thus, the propeptide processing mechanism of ADAMTS5 has several points of distinction from those of other ADAMTS proteases, which may have considerable significance in the context of osteoarthritis.

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This thesis reports on an investigation at the University Tun Abdul Razak (UNITAR), Malaysia focused on students’ needs for student support services. The research addressed a new problem in distance education concerning institutional practices and strategies for providing student support within blended learning contexts, such as at UNITAR. The thesis addresses important matters related to the use of forms of education to address Malaysia’s social, political and economic development.

The study had two main research purposes. The first purpose was to investigate what barriers UNITAR’s students had to completing their study successfully. The second was to investigate students’ support services needs. The latter was divided into six subsidiary purposes. The first subsidiary purpose was to identify and compare the students’ needs intensity for the four categories of support services: administrative, academic, welfare and post-study services. The second subsidiary purpose was to investigate whether there is any correlation between students’ attributes of age, gender, marital status, number of children, enrollment status, distance from learning centre, academic abilities, course satisfaction and academic achievement, with their support needs. The other subsidiary purposes were to compare needs intensity for the four categories of services between men and women, younger and mature-age students, and lower and higher academic achievers.

The research design employed mixed methods, involving both qualitative and quantitative techniques. A series of interviews was conducted with UNITAR staff members during an inventory study of the University. Then, the students were surveyed through a questionnaire that contained closed-ended and openended questions. After analysing and compiling the results of the survey, another cycle of surveys was conducted with selected staff members through email, to validate the findings and obtain their feedback to the students’ views and their suggestions for future improvement. The quantitative survey data were analysed using SPSS, whereas the qualitative data from interview, survey and email were analysed by using content analysis techniques.

The findings of the study demonstrated that UNITAR’s students have problems in their study, which are related to their demographic and institutional attributes, and these affect their needs for four categories of support services. Generally, students attached the highest priority to academic services, followed by post-study services, administrative services and, lastly, welfare services. Four patterns of associations between students’ attributes and support services needs were identified. In particular, support services needs differences were identified between men and women, younger and mature-age students, and lower achieving and higher achieving students.

Drawing the findings of this study, relevant past studies, contemporary practices and constructive views of scholars from the relevant literature, the thesis concludes by proposing an integrated student support framework for UNITAR and suggest how this may be considered and applied more broadly in similar blended learning contexts in Malaysia and beyond.

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Purpose: Because it is believed that bone may respond to exercise differently at different ages, we compared bone responses in immature and mature rats after 12 wk of treadmill running.

Methods
: Twenty-two immature (5-wk-old) and 21 mature (17-wk-old) female Sprague Dawley rats were randomized into a running (trained, N = 10 immature, 9 mature) or a control group (controls, N = 12 immature, 12 mature) before sacrifice 12 wk later. Rats ran on a treadmill five times per week for 60-70 min at speeds up to 26 m[middle dot]min-1. Both at baseline and after intervention, we measured total body, lumbar spine, and proximal femoral bone mineral, as well as total body soft tissue composition using dual-energy x-ray absorptiometry (DXA) in vivo. After sacrificing the animals, we measured dynamic and static histomorphometry and three-point bending strength of the tibia.

Results: Running training was associated with greater differences in tibial subperiosteal area, cortical cross-sectional area, peak load, stiffness, and moment of inertia in immature and mature rats (P < 0.05). The trained rats had greater periosteal bone formation rates (P < 0.01) than controls, but there was no difference in tibial trabecular bone histomorphometry. Similar running-related gains were seen in DXA lumbar spine area (P = 0.04) and bone mineral content (BMC;P = 0.03) at both ages. For total body bone area and BMC, the immature trained group increased significantly compared with controls (P < 0.05), whereas the mature trained group gained less than did controls (P < 0.01).

Conclusion
: In this in vivo model, where a similar physical training program was performed by immature and mature female rats, we demonstrated that both age groups were sensitive to loading and that bone strength gains appeared to result more from changes in bone geometry than from improved material properties.