The culture-based fisheries in small, farmer-managed reservoirs in two provinces of northern Vietnam: an evaluation based on three production cycles

In this paper the results of a study conducted on the culture-based fisheries in small (ranging from 2 to 160 ha), farmer-managed reservoirs in YenBai and ThaiNguyen Provinces in the northern highland region of Vietnam, for the production cycles of 1997/98, 98/99 and 99/00 are presented. The small reservoirs are leased to small farmers by the provincial authorities for fishery activities, and all lessees adopt culture-based fisheries when fingerlings of grass carp (Ctenopharyngodon idella), silver carp (Hypophthalmichthys molitrix), bighead carp (Aristichthys nobilis), common carp (Cyprinus carpio) and mrigal (Cirrihinus mrigala) are stocked between March and mid-April each year and harvested, using large seine nets, after approximately 11-12 months. The mean yields from reservoirs in YenBai and ThaiNguyen Provinces in 97/98, 98/99 and 99/00 production cycles were 251, 332 and 253, and 331, 372 and 210 kg ha⁻¹ respectively. There were major differences in the fish productivity in the reservoirs in the two Provinces, and in a reservoir between culture cycles. The stocking strategies appeared to be rather ad hoc, being determined by the availability of seed stock and the financial status of the lessees. Accordingly, there was no apparent consistent trend in the improvement of yields from the culture-based fishery practice throughout the growth cycles. The fish yields in reservoirs in each Province were significantly related to reservoir area (exponentially) and to mean weight of stocked fish and conductivity (logarithmically). Of the stocked fish, the highest returns were obtained with mrigal and bighead carp, which collectively contributed > 50% to the harvest. The return from common carp was the lowest. The mean growth rate of grass carp (2.7 g day⁻¹), followed by bighead carp (2.0 g day⁻¹) was the highest in reservoirs in YenBai Province, bighead carp (4.0 g day⁻¹) followed by grass carp (3.2 g day⁻¹) was the highest in ThaiNguyen Province. The seed stocked on average accounted for 65% and 48% of the total operating costs in YenBai and ThaiNguyen Provinces, and the mean cost:benefit ratio of the culture-based fishery in the two Provinces was 0.35 and 0.37 respectively. The culture-based fishery on average contributed about 28% to the gross income of a farmer lessee.

Southern drift : the learning styles of first and third-year students of the built environment

This paper investigates learning processes across a built environment design curriculum through the recognition of the four learning styles defined in the experiential learning theory of Kolb, i.e., 'accommodating', 'diverging', 'assimilating' and 'converging.' The paper focuses on the results of a cross-curriculum learning style survey. The results of the survey appear to explain why many prior studies of the personality characteristics, learning and cognitive styles of practitioners and of design students at different stages of their education appear conflicting. The hypothesis tested to resolve these inconsistencies asked whether design-learning styles are fixed or change as students' progress through their studies. The survey provides evidence of a statistically significant relationship between learning styles and year of study. The evidence suggests a southern drift (the term refers to the spatial interrelationship of styles in the two-dimensional Kolb Learning Style Index [LSI] cycle) towards the abstract conceptualisation mode of the learning process as students near the completion of their studies. This fluidity in learning style remains a hypothesis until further research is able to study one cohort for the entirety of a degree program. The paper argues that the possibility of learning style fluidity needs determining if learning style theory is to provide a workable model for informing the teaching of architecture.

Family and home correlates of television viewing in 12-13 year old adolescents: the Nepean study

Background
Few young people meet television viewing guidelines.
Purpose
To determine the association between factors in the family and home environment and watching television, including videos and DVDs, in early adolescence.
Methods
Cross-sectional, self-report survey of 343 adolescents aged 12–13 years (173 girls), and their parents (338 mothers, 293 fathers). Main measures were factors in the family and home environment potentially associated with adolescents spending ≥ 2 hours per day in front of the television. Factors examined included family structure, opportunities to watch television/video/DVDs, perceptions of rules and regulations on television viewing, and television viewing practices.
Results
Two-thirds of adolescents watched ≥ 2 hours television per day. Factors in the family and home environment associated with adolescents watching television ≥ 2 hours per day include adolescents who have siblings (Adjusted Odds Ratio [95%CI] AOR = 3.0 [1.2, 7.8]); access to pay television (AOR = 2.0 [1.1, 3.7]); ate snacks while watching television (AOR = 3.1 [1.8, 5.4]); co-viewed television with parents (AOR = 2.3 [1.3, 4.2]); and had mothers who watched ≥ 2 hours television per day (AOR = 2.4 [1.3, 4.6]).
Conclusion
There are factors in the family and home environment that influence the volume of television viewed by 12–13 year olds. Television plays a central role in the family environment, potentially providing a means of recreation among families of young adolescents for little cost. Interventions which target family television viewing practices and those of parents, in particular, are more likely to be effective than interventions which directly target adolescent viewing times.

Hepatitis B Virus transmission and hepatocarcinogenesis: a 9 year retropective cohort of 13676 relatives with hepatocellular carcinoma

Background/Aims
Familial clustering of hepatitis B virus (HBV) infection is related to perinatal transmission, and is the main cause of familial-type hepatocellular carcinoma (HCC). The route of HBV transmission differs between the children and siblings of patients with HCC. This study examined the differences in HBV carrier rates and HCC-related mortality between two generations in HCC families.
Methods
From 1992 to 1997, relatives of individuals with HCC were screened prospectively with ultrasonography, alpha-fetoprotein, liver biochemistry tests and viral markers. Total HCC-related deaths during a 9-year period were compared between the generations of index patients and their children.
Results
The study included a total of 13 676 relatives in two generations. More HCC-related deaths occurred in the index patient generation than in the child generation. Furthermore, children of female index patients had higher rates of liver cancer related mortality than children of male index patients. The same was true when the analysis was limited to male HBV carriers. The prevalence of HBsAg in the offspring of HBsAg positive mothers was 66% in the child generation and 72% in the index patient generation. These high prevalences indicated high maternal HBV replication status.
Conclusions
Perinatal transmission and maternal viral load are important risk factors in hepatocarcinogenesis.

Sir, can x equal x plus two?

Technology in classrooms has brought opportunities to develop new ways of teaching and learning, as well as new ways of thinking and communicating. The author describes a lesson which aimed to have the grade four children in the class construct on the computer screen images of rectangles. The lesson provided the opportunity to learn about some powerful generalisations about rectangles as well to learn about their geometric and algebraic understandings.

Year 12 students' mental models of the nature of light

This paper reports on the third year of a three-year longitudinal investigation into six Year 10 secondary students’ understanding of optics at a secondary school level. During the first two years of the study the students’ understanding of geometrical optics was explored with the adoption of constructivist teaching and learning strategies. The students' understanding of geometrical optics following the Year 11 teaching stage then formed the basis of exploration of their mental models of the nature of light. This exploration occurred before, during and following a Year 12 teaching stage where the students studied physical optics and quantum ideas. Before the Year 12 teaching stage the students had constructed mental models of light that related to their understanding of a ray. Over the Year 12 teaching stage the students’ mental models changed to conceptualizations of a photon. There was evidence in the students’ mental models of a hybridization of the particle and wave scientific models. That is, they conceptualized the photon as having both wave and particle characteristics. The variation in the students’ hybrid models also suggested a variation in the way they conceived of the nature of scientific models.

Does self-management lead to sustainable health benefits in people with arthritis? A 2-year transition study of 452 Australians.

Objective: To evaluate the Arthritis Self-Management Course (ASMC) when applied in a nationwide context.

Methods: Four hundred fifty-two people who participated in the ASMC across Australian states took part in a longitudinal followup study. ASMC is a 6 week, 2 h group educational program designed to assist people with chronic illness to better manage their condition. Measures of program effectiveness included health status and service utilization. Data were collected on 3 occasions: before intervention (baseline) and 6 months and 2 years after the program.

Results: Several indicators of health status showed improvement at 6 months following the ASMC. These included reduction in pain (4%; p < 0.001), fatigue (3%; p < 0.01), and health distress (12%; p < 0.001) as well as increase in self-efficacy (6%; p < 0.001). Increased self-efficacy was a significant predictor of positive change in health status. Health-related behaviors such as aerobic exercise also increased, with the proportion of people who did little or no exercise decreasing by up to 8%. These changes were sustained at 2 years. There was an increase in use of analgesics at 6 months and an increase in use of nonsteroidal antiinflammatory drugs at 2 years. No changes in healthcare utilization (physician visits, allied health visits, and hospitalizations) were observed.

Conclusion: The ASMC is a widely applied program in which participants benefit through a reduction in pain, fatigue, and health distress. Although the absolute changes in health status are small, the low cost and wide application of the intervention suggests the program may have a substantial public health effect.

Six year follow-up of students who participated in a school-based physical activity interventions : a longitudinal cohort study

Background
The purpose of this paper was to evaluate the long-term impact of a childhood motor skill intervention on adolescent motor skills and physical activity.

Methods
In 2006, we undertook a follow-up of motor skill proficiency (catch, kick, throw, vertical jump, side gallop) and physical activity in adolescents who had participated in a one-year primary school intervention Move It Groove It (MIGI) in 2000. Logistic regression models were analysed for each skill to determine whether the probability of children in the intervention group achieving mastery or near mastery was either maintained or had increased in subsequent years, relative to controls. In these models the main predictor variable was intervention status, with adjustment for gender, grade, and skill level in 2000. A general linear model, controlling for gender and grade, examined whether former intervention students spent more time in moderate-to-vigorous physical activity at follow-up than control students.

Results
Half (52%, n = 481) of the 928 MIGI participants were located in 28 schools, with 276 (57%) assessed. 52% were female, 58% in Grade 10, 40% in Grade 11 and 54% were former intervention students. At follow-up, intervention students had improved their catch ability relative to controls and were five times more likely to be able to catch: ORcatch = 5.51, CI (1.95 – 15.55), but had lost their advantage in the throw and kick: ORthrow = .43, CI (.23 – .82), ORkick = .39, CI (.20 – .78). For the other skills, intervention students appeared to maintain their advantage: ORjump = 1.14, CI (.56 – 2.34), ORgallop = 1.24, CI (.55 – 2.79). Intervention students were no more active at follow-up.

Conclusion
Six years after the 12-month MIGI intervention, whilst intervention students had increased their advantage relative to controls in one skill, and appeared to maintain their advantage in two, they lost their advantage in two skills and were no more active than controls at follow up. More longitudinal research is needed to explore whether gains in motor skill proficiency in children can be sustained and to determine the intervention characteristics that translate to subsequent physical activity.

Year 8 students' understanding of astronomy as a representational issue : insights from a classroom video study

The research described in this paper argues that difficulties of leaming science concepts such as those associated with processes involving the Sun, Moon and Earth, such as day and night, the seasons and phases of the moon, are fundamentally representational in nature. There is a need for learners to use their own representational, cultural and cognitive resources to engage with the subject-specific representational practices of science. From this perspective students need to understand and conceptually integrate different representational modalities or forms in learning science and reasoning in science. The researchers worked with two experienced teachers in planning a teaching sequence in astronomy using a teaching approach that highlight representational issues and options in helping students explore and develop key conceptual understandings. Classroom sequences involving the two teachers were videotaped using a combined focus on the teacher and groups of students. Video analysis software was used to capture the variety of representations used, and sequences of representational negotiation. From a pedagogical perspective the representational approach placed a significant agency in the hands of students which resulted in structured discussions around conceptual problems. Representations were used as tools for reasoning and communication to drive classroom discussions and develop higher levels of understanding in the students. The pre- and post-testing showed significant gains in students thinking from naive to more scientific understandings of astronomy.

Manage one beach or two? Movements and space-use of the threatened hooded plover (Thinornis rubricollis) in south-eastern Australia

An understanding of space use and dispersal of a wildlife species is essential for effective management. We examined the movements of a beach-dwelling, threatened population of hooded plover (Thinornis rubricollis) in southern central Victoria, Australia, by analysing sightings of colour-banded birds (4897 sightings; 194 birds tracked for up to 9 years). Most movements were relatively short (5050 ± 305 m), with 61.4% <1 km and 95.3% <20 km; they lacked directional or sexual bias. The extent of coastline used by individual birds was 47.8 ± 58.0 km. Regional differences in average distances moved by adults were apparent. For adults, movement rates (mean distance per day) were higher during the non-breeding season than during the breeding season. Non-breeding adults generally remained close to their partners (non-breeding, 456.3 ± 163.9 m; breeding, 148.2 ± 45.3 m). Largest flock sizes were recorded during the non-breeding period, and flocking was not uniformly distributed along the coast but appeared to be concentrated in particular locations. The frequency of pair cohesion (i.e. when the distance between partners was zero on a given day) was similar during the breeding (69.6%) and non-breeding seasons (67.7%). Breeding territories (kernel analysis) were 36.7 ± 5.7 ha and overlapped from year to year in all cases (23 pairwise comparisons; 47.9 ± 7.1% overlap). The high fidelity and constancy of territories confirms they warrant ongoing management investment, although the species relies on a matrix of breeding and non-breeding sites. The latter appear to occur in specific parts of the coast and warrant enhanced protection and more research attention. Fragmentation of the breeding population might occur where habitat is rendered unsuitable for > ~50 km.

Calculators, mathematics and young children : a study of six children using calculators as part of the mathematics curriculum during their first two years of school

The thesis investigates the role a calculator can play in the developing number knowledge of three girls and three boys as part of their mathematics program, during their first two years at primary school. Random sampling was used initially to select six girls and six boys from the twenty-four children entering a 1993 prep class. These twelve children were interviewed on entrance to school and based on the performance of the twelve children on the initial interview, a girl and a boy were chosen from the higher, middle and lower achievers to take part in the full study. The class teachers involved were previously participants in the ‘Calculators in Primary Mathematics’ research program and were committed to the use of calculators in their mathematics program. A case study approach using qualitative methods within the activity theory framework is used to collect relevant data and information, an analysis of five interviews with each child and observations of the children in forty-one classroom lessons provides comprehensive data on the children's developing number knowledge during the two years. The analysis questionnaires establishes each teacher's perceptions of the children's number learning at the beginning and end of each year, compares teacher expectations with children's actual performance for the year and compares curriculum expectations with children's actual performance. A teacher interview established reasons for changes in teaching style; teacher expectations; children's number learning; and was used to confirm my research findings. An activity theory framework provides an appropriate means of co-coordinating perspectives within this research to enable a description of the child's number learning within a social environment. This framework allows for highlighting the mediation offered by the calculator supporting the children's number learning in the classroom. Levels of children's developing number knowledge reached when working with a calculator and as a result of calculator use are mapped against the levels recommended in ‘Mathematics in the National Curriculum’ (National Curriculum Council, December 1988), and the Curriculum and Standards Framework: Mathematics (Board of Studies 2000). Findings from this comparison illustrate that the six children's performance in number was enhanced when using a calculator and indicate that on-going development and understanding of number concepts occurred at levels of performance at least two years in advance of curriculum recommendations for the first two years of school.

Communication and meaning : the first year experience of off-campus study

The substantive field of the thesis is the sociology of distance education. The issues investigated centre on the relationship between off-campus students and the institutions of higher education with which they enrol, in which the first year experience is construed as an encounter between the students’ personal contexts and institutional cultures. A theoretical framework is constructed which synthcsises elements of phenomenology, hermeneutics and feminist theory. The author reports research into the way a small sample of people experienced off-campus study. The students selected resided in Victoria, Australia, and were enrolled with one of two Victorian tertiary institutions: the (then) Gippsland Institute of Advanced Education and Deakin University. Using a case study approach, the subjective experiences of the students were studied by means of a series of interviews which took place at their homes or places of employment in the period January 1988 to November 1989. Methodological issues relating to the application of hermeneutic principles to the use of interviews in educational research are explored. The results of the interpretation of the interview material are presented in terms of an integrationist model of socialisation. The thesis argued is that certain theoretical and practical issues in distance education are best understood as social and cultural phenomena rather than as technical problems. The implications of the findings about the effects of gender and culture on student experience are discussed in relation to the issues of access and equity, student support, and models of teaching and learning.

Comparison in studying approaches of first-year Australian and overseas Chinese university students

This research investigates the studying approaches of first-year Australian and overseas Chinese university students. It is also designed to determine the robustness of Entwistle and Ramsden's (1983) Approaches to Studying Inventory (ASI). Two hundred and two first-year Australian students and two hundred and forth eight first-year overseas Chinese students, drawn from Deakin University and Swinburne University of Technology, were tested using the ASL The data obtained from the two groups were subjected to factor analysis (with orthogonal rotation). For Australian students, a four-factor structure in studying approaches, which accounts for 55.6% of the total variance, was obtained. The factors are Meaning Orientation; Non-Academic Orientation; Anxious-Rigid Orientation; and Goal Orientation. For overseas Chinese students, a three-factor structure in studying approaches which accounts for 52.8% of the total variance was obtained. The factors are Anxious-Surface Orientation; Self-Motivated, Reflective Orientation; and Efficiency Orientation, Cattell's (1949) salient similarity S index indicates a close resemblance between factors obtained for Australian students and the original factors obtained by Entwistle and Ramsden (1983). Similarities are also indicated between factors obtained for Australian and overseas Chinese students* Two main conclusions are drawn. First, the studying approaches of first-year Australian and overseas Chinese university students are described by different factor structures in learning. Second, Entwistle and Ramsden's (1983) Approaches to Studying Inventory is a robust tool from which reliable and meaningful factors in student studying approaches can be obtained. Several implications of the research findings are discussed.