Showing papers by "La Trobe University published in 1996"
TL;DR: In this article, two statistical tests for detecting a heterozygosity excess are described, and the most useful markers for bottleneck detection are those evolving under the infinite allele model (IAM) and they provide guidelines for selecting sample sizes of individuals and loci.
Abstract: When a population experiences a reduction of its effective size, it generally develops a heterozygosity excess at selectively neutral loci, i.e., the heterozygosity computed from a sample of genes is larger than the heterozygosity expected from the number of alleles found in the sample if the population were at mutation drift equilibrium. The heterozygosity excess persists only a certain number of generations until a new equilibrium is established. Two statistical tests for detecting a heterozygosity excess are described. They require measurements of the number of alleles and heterozygosity at each of several loci from a population sample. The first test determines if the proportion of loci with heterozygosity excess is significantly larger than expected at equilibrium. The second test establishes if the average of standardized differences between observed and expected heterozygosities is significantly different from zero. Type I and II errors have been evaluated by computer simulations, varying sample size, number of loci, bottleneck size, time elapsed since the beginning of the bottleneck and level of variability of loci. These analyses show that the most useful markers for bottleneck detection are those evolving under the infinite allele model (IAM) and they provide guidelines for selecting sample sizes of individuals and loci. The usefulness of these tests for conservation biology is discussed.
4,106 citations
TL;DR: This review will deal with the 16s-23s spacer region of the rRNA operon and its use in the identification of micro-organisms at the species and strain (typing) levels.
Abstract: Medical microbiology is extremely reliant on the culture of bacteria from clinical specimens and their subsequent identification by biochemical and phenotypic characteristics for the diagnosis of disease. Following determination of the structure of DNA by Watson & Crick (1953), studies in bacteriology have seen a major shift from functional to molecular techniques for identifying bacteria (Towner & Cockayne, 1993). This review will deal with the 16s-23s spacer region of the rRNA operon (Fig. 1) and its use in the identification of micro-organisms at the species and strain (typing) levels.
987 citations
TL;DR: It is demonstrated that training with both visual cues and attentional strategies could maintain normal gait for the maximum recording time of 2 h and that gait hypokinesia reflects a difficulty in activating the motor control system.
Abstract: Summary Results of our previous studies have shown that the slow, shuffling gait of Parkinson's disease patients is due to an inability to generate appropriate stride length and that cadence control is intact and is used as a compensatory mechanism The reason for the reduced stride length is unclear, although deficient internal cue production or inadequate contribution to cortical motor set by the basal ganglia are two possible explanations In this study we have examined the latter possibility by comparing the long-lasting effects of visual cues in improving stride length with that of attentional strategies Computerized stride analysis was used to measure the spatial (distance) and temporal (timing) parameters of the walking pattern in a total of 54 subjects in three separate studies In each study Parkinson's disease subjects were trained for 20 min by repeated 10 m walks set at control stride length (determined from control subjects matched for age, sex and height), using either visual floor
876 citations
Journal Article•
TL;DR: The results indicate that IFN-gamma is not essential for the generation or function of anti-MOG35-55 effector cells but does play an important role in down-regulating EAE at both the effector and induction phase of disease.
Abstract: 129/Sv mice are resistant to induction of experimental autoimmune encephalomyelitis (EAE) induced with myelin oligodendrocyte glycoprotein peptide (MOG35-55). Mice of this strain lacking the gene coding for the ligand-binding chain of the IFN-gamma receptor develop EAE with high morbidity and mortality. Spleen cells from sensitized IFN-gammaR-/- mice proliferated extensively when stimulated with MOG peptide in culture and produced high levels of IFN-gamma and TNF but no detectable IL-4. Transfer of spleen cells from sensitized IFN-gammaR-/- mice produced EAE in both IFN-gammaR+/+ and IFN-gammaR-/- recipients. Disease was severe in IFN-gammaR-/- recipients and mortality high (77%). Surviving mice remained moribund until termination of the experiments. IFN-gammaR+/+ recipients developed disease of equal severity, but with no mortality, and recovered significantly. These results indicate that IFN-gamma is not essential for the generation or function of anti-MOG35-55 effector cells but does play an important role in down-regulating EAE at both the effector and induction phase of disease.
644 citations
TL;DR: In this article, the authors look at the conceptions of teaching and learning of a group of first year science lecturers, and how those conceptions relate to their approaches to teaching, and they find that lecturers with highly developed notions of teaching differentiated between teaching and teaching in quite different ways to those with less well-developed conceptions.
Abstract: Studies of student learning have shown that students' conceptions of learning are strongly correlated with their approaches to study. Students who consider learning in quantitative terms are likely to find it very difficult to adopt a deep approach to learning. This study looks at the parallel situation for teachers. It looks at the conceptions of teaching and learning of a group of first year science lecturers, and how those conceptions relate to their approaches to teaching. The results also parallel those found for students. Strong relations are found between conceptions of teaching and approaches to teaching. Relations between conceptions of teaching and conceptions of learning were not so strong, but lecturers with highly developed conceptions of teaching differentiated between teaching and learning in quite different ways to those with less well-developed conceptions. The implications of these results for the practice and development of teaching in higher education are discussed.
477 citations
TL;DR: The results suggest that it may be possible to identify female athletes most at risk for this overuse bone injury, and multiple logistic regression revealed that age of menarche and calf girth were the best independent predictors of stress fractures in women.
Abstract: The aim of this 12-month prospective study was to investigate risk factors for stress fractures in a cohort of 53 female and 58 male track and field athletes, aged 17 to 26 years. Total bone mineral content, regional bone density, and soft tissue composition were measured using dual-energy x-ray absorptiometry and anthropometric techniques. Menstrual characteristics, current dietary intake, and training were assessed using questionnaires. A clinical biomechanical assessment was performed by a physical therapist. The incidence of stress fractures during the study was 21.1% with most injuries located in the tibia. Of the risk factors evaluated, none was able to predict the occurrence of stress fractures in men. However, in female athletes, significant risk factors included lower bone density, a history of menstrual disturbance, less lean mass in the lower limb, a discrepancy in leg length, and a lower fat diet. Multiple logistic regression revealed that age of menarche and calf girth were the best independent predictors of stress fractures in women. This bivariate model correctly assigned 80% of the female athletes into their respective stress fracture or nonstress fracture groups. These results suggest that it may be possible to identify female athletes most at risk for this overuse bone injury.
451 citations
TL;DR: In this article, an empirical study of the congruence between intention and strategy of university science teachers' approaches to teaching in their first year science courses in Australia was carried out and the results confirmed the proposed relationship between intentions and strategies, and concluded that the traditional form of academic development focussing on teaching strategies is unlikely to be successful without an ongoing focus on the intentions which are associated with the strategy.
Abstract: This paper describes the results, and some implications, of an empirical study of the congruence between intention and strategy of university science teachers' approaches to teaching in their first year science courses The study drew upon the results of a previous phenomenographic study which identified qualitatively different approaches to teaching An approaches to teaching inventory was subsequently developed which included scales representing the intentions and strategies identified in the first study This inventory was distributed to a sample of university teachers of first year science courses in Australia The results confirmed the proposed relationship between intention and strategy, and showed that a Student-focused Strategy was associated with a Conceptual Change Intention, while a Teacher-focused Strategy was associated with an Information Transfer Intention It is concluded that the traditional form of academic development focussing on teaching strategies (for example, activity based strategies) is unlikely to be successful without an ongoing focus on the intentions which are associated with the strategy
382 citations
TL;DR: Considerable potential within the wheat genome to breed varieties with greater competitive ability was demonstrated, and the potential for breeding enhanced competitive ability in wheat is discussed.
Abstract: Summary
The competitive abilities of a wide range of genotypes of wheat (Trilicvm aestivum L.) and durum wheat (Triticum durum Desf.) against Lolium rigidum Gaud, (annual ryegrass) were examined 1o determine the potential for breeders to select strongly competitive varieties, Considerable potential within the wheat genome to breed varieties with greater competitive ability was demonstrated. In 1993, 250 genotypes from around the world were screened and in 1994 a subset of 45 (mainly Australian) genotypes were further examined. A uniform density of L. rigidum reduced grain yield of wheat by up to about 80% in 1993 and to 50% in 1994, depending on wheat genotype. Reduction in grain yield was correlated with L. rigidum dry matter. Wheats varied in competitive ability with source, and durum wheats were less competitive than T. aestivum. The ‘old’ standard wheat varieties (released between 1880 and 1950) suppressed the weed more than all the current varieties, with the exception of eight F1 hybrids. A doubling of the crop seeding rate of 10 of the genotypes in 1994 reduced the biomass of L. rigidum by an average of 25% compared with the standard seeding rate. Ranking of competitive ability of varieties at high density was consistent at both seeding rates. The strongly competitive genotypes had high early biomass accumulation, large numbers of tillers, and were tall with extensive leaf display. The potential for breeding enhanced competitive ability in wheat is discussed.
380 citations
TL;DR: The high incidence of stress fractures in track and field athletes and the most common sites of bone injuries were the tibia with 12 injuries (46%), followed by the navicular with 4 injuries (15%), and the fibula with 3 injuries (12%).
Abstract: The incidence and distribution of stress fractures were evaluated prospectively over 12 months in 53 female and 58 male competitive track and field athletes (age range, 17 to 26 years). Twenty athletes sustained 26 stress fractures for an overall incidence rate of 21.1%. The incidence was 0.70 for the number of stress frac tures per 1000 hours of training. No differences were observed between male and female rates (P > 0.05). Twenty-six stress fractures composed 20% of the 130 musculoskeletal injuries sustained during the study. Although there was no difference in stress fracture incidence among athletes competing in different events (P > 0.05), sprints, hurdles, and jumps were associated with a significantly greater number of foot fractures; middle- and long-distance running were as sociated with a greater number of long bone and pelvic fractures (P < 0.05). Overall, the most common sites of bone injuries were the tibia with 12 injuries (46%), followed by the navicular with 4 injuries (15%), and the fibu...
354 citations
TL;DR: Microsatellite and mitochondrial DNA data call for the protection of the island populations of B. terrestris against importation of bumble bees of foreign origin which are used as crop pollinators as well as a severe bottleneck in the Canary island population.
Abstract: Ten microsatellite loci and a partial sequence of the COII mitochondrial gene were used to investigate genetic differentiation in B. terrestris, a bumble bee of interest for its high-value crop pollination. The analysis included eight populations from the European continent, five from Mediterranean islands (six subspecies altogether) and one from Tenerife (initially described as a colour form of B. terrestris but recently considered as a separate species, B. canariensis). Eight of the 10 microsatellite loci displayed high levels of polymorphism in most populations. In B. terrestris populations, the total number of alleles detected per polymorphic locus ranged from 3 to 16, with observed allelic diversity from 3.8 +/- 0.5 to 6.5 +/- 1.4 and average calculated heterozygosities from 0.41 +/- 0.09 to 0.65 +/- 0.07. B. canariensis showed a significantly lower average calculated heterozygosity (0.12 +/- 0.08) and observed allelic diversity (1.5 +/- 0.04) as compared to both continental and island populations of B. terrestris. No significant differentiation was found among populations of B. terrestris from the European continent. In contrast, island populations were all significantly and most of them strongly differentiated from continental populations. B. terrestris mitochondrial DNA is characterized by a low nucleotide diversity: 0.18% +/- 0.07%, 0.20% +/- 0.04% and 0.27% +/- 0.04% for the continental populations, the island populations and all populations together, respectively. The only haplotype found in the Tenerife population differs by a single nucleotide substitution from the most common continental haplotype of B. terrestris. This situation, identical to that of Tyrrhenian islands populations and quite different from that of B. lucorum (15 substitutions between terrestris and lucorum mtDNA) casts doubts on the species status of B. canariensis. The large genetic distance between the Tenerife and B. terrestris populations estimated from microsatellite data result, most probably, from a severe bottleneck in the Canary island population. Microsatellite and mitochondrial DNA data call for the protection of the island populations of B. terrestris against importation of bumble bees of foreign origin which are used as crop pollinators.
294 citations
TL;DR: It is found that stress applied specifically to the mitochondria of mammalian cells is capable of eliciting an organelle-specific, molecular chaperone response.
Abstract: Molecular chaperones are known to play key roles in the synthesis, transport and folding of nuclear-encoded mitochondrial proteins and of proteins encoded by mitochondrial DNA. Although the regulation of heat-shock genes has been the subject of considerable investigation, regulation of the genes encoding mitochondrial chaperones is not well defined. We have found that stress applied specifically to the mitochondria of mammalian cells is capable of eliciting an organelle-specific, molecular chaperone response. Using the loss of mitochondrial DNA as a means of producing a specific mitochondrial stress, we show by Western-blot analysis that mtDNA-less (rho 0) rat hepatoma cells show an increase in the steady-state levels of chaperonin 60 (cpn 60) and chaperonin 10 (cpn 10). Nuclear transcription assays show that the upregulation of these chaperones is due to transcriptional activation. There was no effect on the inducible cytosolic Hsp 70, Hsp 72, nor on mtHsp 70 in rho 0 cells, leading us to concluded that stress applied selectively to mitochondria elicits a specific molecular chaperone response. Heat stress was able to provide an additional induction of cpn 60 and cpn 10 above that obtained for the rho 0 state alone, indicating that these genes have separate regulatory elements for the specific mitochondrial and general stress responses. Since the mitochondrial-specific chaperones are encoded by nuclear DNA, there must be a mechanism for molecular communication between the mitochondrion and nucleus and this system can address how stress is communicated between these organelles.
Book•
01 Dec 1996TL;DR: This book discusses the evolution of management and Organization Theory and its applications in public administration, as well as some of the techniques used in management and organization theory.
Abstract: Chapter 1 Defining Public Administration Chapter 2 The Political and Cultural Environment of Public Policy and Its Administration Chapter 3 The Continuous Reinventing of the Machinery of Government Chapter 4 Intergovernmental Relations Chapter 5 Honor, Ethics, and Accountability Chapter 6 The Evolution of Management and Organization Theory Chapter 7 Organizational Behavior Chapter 8 Managerialism and Information Technology Chapter 9 Strategic Management and Government Regulation Chapter 10 Leadership Chapter 11 Personnel Management and Labor Relations Chapter 12 Social Equity Chapter 13 Public Financial Management Chapter 14 Program Audit and Evaluation
TL;DR: Gait velocity discriminated the effect of stroke and the change during rehabilitation and indicated that there was a high signal-to-noise ratio and a robust effect size.
TL;DR: Another Wolbachia infection is described in D. simulans that does not cause cytoplasmic incompatibility and may represent an evolutionary outcome of interactions between Wolbachian infections and their hosts.
Abstract: Microbes of the genus Wolbachia are transmitted by their hosts via the maternal parent and are responsible for cytoplasmic incompatibility among insect populations. This phenomenon can result in Wolbachia spreading through natural populations as previously demonstrated in Drosophila simulans. Here we describe another Wolbachia infection in D. simulans that does not cause cytoplasmic incompatibility. This is a property of the Wolbachia rather than the nuclear background. The infection occurs at a low frequency in natural populations from eastern Australia. The infection shows perfect maternal transmission in the field and does not cause any detectable deleterious effects on its host. These findings suggest that the Wolbachia infection behaves like a neutral variant in populations. The infection may represent an evolutionary outcome of interactions between Wolbachia infections and their hosts.
TL;DR: Two broad governamental rationalities may be discerned in the overall discourses of community policing since the 1960s: a Keynesian, welfarist form which links plice to the community via extended welfare-service and protective roles, and a post-Keynesian plitical rationality replaces this model with one in which the community appears as knowledgeable about local conditions, and (with some training) competent to from a partnership with plice.
Abstract: Two broad governamental rationalities may be discerned in the overall discourses of community policing since the 1960s. The first is a Keynesian, welfarist form which links plice to the community via extended welfare-service and protective roles. This was associated with relations of expertise that subordinated the public in a dependent, client relation. The ascendancy of post-Keynesian plitical rationalities replaces this model with one in which the community appears as knowledgeable about local conditions, and (with some training) competent to from a partnership with plice. Discourses of community policing thus have manifested an altered content of ‘community’ over this period. In the early years, community was the local site of state and social forms of intervention. In recent years the emphasis has been on images of the community as voluntary rather than imposed, private rather than state or public, co-operative rather than hierarchical. This image of ‘community’ is particularly attractive to post-Key...
TL;DR: Clinicians can confidently and quantitatively sample one aspect of proprioceptive sensibility in stroke patients using the wrist position sense test, and development of tests on other joints using the present approach is supported by the findings.
TL;DR: It is concluded that the effect of stage of lactation was magnified by an elevated BMCC, and that many of the problems encountered when processing late season milk could be overcome by containing mastitis at this time.
Abstract: The effects of somatic cell count and stage of lactation on the yield and quality of Cheddar cheese were investigated. Cheese was manufactured in a pilot scale factory using milk of low bulk milk cell count (BMCC) from herds in early (LE) and late (LL) lactation, and milk of high BMCC from herds in early (HE) and late (HL) lactation. The deleterious effect of an elevated BMCC on product yield and quality in late lactation was clear. Cheese made from LL milk was significantly superior to that made from HL milk for most yield and quality characteristics measured. Stage of lactation also affected cheese yield and quality, as evidenced by the lower recovery of fat and poorer flavour score for cheese from LL milk compared with that manufactured from LE milk. The observed differences could be explained largely by differences in raw milk composition. We conclude that the effect of stage of lactation was magnified by an elevated BMCC, and that many of the problems encountered when processing late season milk could be overcome by containing mastitis at this time.
TL;DR: The authors show that the non-configurationality characteristics of free word order, null anaphora, and split NPs are independent of each other and of the distribution of bound pronouns.
Abstract: The syntax of the Australian Aboriginal language Warlpiri has led to two opposing models of non-configurationality: a dual structure hypothesis, which abandons the projection principle for a grammatical architecture that separates constituency and functional representations (Simpson 1983, 1991, Hale 1983, Kroeger 1993), and a pronominal argument hypothesis, which hypothesizes that bound or zero pronominals satisfy the projection principle in such languages, with free nominals analysed as adjuncts (Jelinek 1984, Baker 1991, Hale 1993). Although the pronominal argument hypothesis is widely accepted in the syntactic literature, we show that available evidence from Warlpiri, new evidence from the related language Jiwarli, and a survey of six other Australian languages actually support the dual structure hypothesis. The non-configurationality characteristics of free word order, null anaphora, and split NPs are in fact independent of each other and of the distribution of bound pronouns. Additionally, the clitic pronouns that Jelinek (1984) and others take to be the source of non-configurationality in Warlpiri are simply an areal feature of Australian languages that is independent of the syntactic properties that are supposed to derive from it.
TL;DR: P Penguins bred either in the centre of a colony or at its periphery had no significant influence upon their breeding success and disturbance treatment and colony size influenced hatching success and chick survival significantly, but there was no statistical interaction between these parameters.
TL;DR: The hypothesis that this organism is phylogenetically unique and at present is the first representative of a new deeply branching lineage of the Bacteria is supported.
Abstract: A new strictly anaerobic bacterium (strain BAL-1T) has been isolated from a reed bed at Ballarat Goldfields in Australia. The organism grew by reducing arsenate [As(V)] to arsenite [As(III)], using acetate as electron donor and carbon source; acetate alone did not support growth. When BAL-1T was grown with arsenate as the terminal electron acceptor, acetate could be replaced by pyruvate, l- and d-lactate, succinate, malate, and fumarate but not by H2, formate, citrate, glutamate, other amino acids, sugars, or benzoate. With acetate was the electron donor, arsenate could be replaced by nitrate or nitrite but not by sulfate, thiosulfate, or iron oxide. Nitrate was reduced to ammonia via nitrite. The doubling time for growth on acetate (5 mM) plus arsenate (5 mM) or nitrate (5 mM) was 4 h. The G+C content of the DNA is 49 mol%. The 16S rRNA sequence data for the organism support the hypothesis that this organism is phylogenetically unique and at present is the first representative of a new deeply branching lineage of the Bacteria. This organism is described as Chrysiogenes arsenatis gen. nov., sp. nov.
TL;DR: The authors showed that massive, matrix and disseminated sulphide ores and a komatiite from Western Australia yield a magmatic Re-Os isochron age of 2,706 ± 36 Myr and a near-chondritic initial 187Os/188Os ratio of 0.10889 ± 0.00035, whereas a proposed sulphidic sedimentary contaminant has an extremely radiogenic 187O/188O ratio of 1.0983 at 2.706 Myr.
Abstract: THE late Archaean greenstone terranes of Western Australia contain abundant komatiites (high-MgO lavas) hosting magmatic sulphide deposits rich in nickel, copper and platinum-group elements. Thermal erosion and assimilation of sulphidic sea-floor sediments has been proposed as a mechanism by which the komatiites were brought to sulphide saturation1–4. Such models have important implications not only for the genesis of these sulphide ores, but also for interpreting the magnitude and extent of isotopic heterogeneity in the Archaean mantle. Here we report that massive, matrix and disseminated sulphide ores and a komatiite from Western Australia yield a magmatic Re–Os isochron age of 2,706 ± 36 Myr and a near-chondritic initial 187Os/188Os ratio of 0.10889 ± 0.00035, whereas a proposed sulphidic sedimentary contaminant has an extremely radiogenic 187Os/188Os of 1.0983 at 2,706 Myr. These data demonstrate that the ore-forming komatiites were derived from the upper mantle without significant contamination by radiogenic crust either before eruption or during turbulent flow at the surface. Thus, ground melting and assimilation of sulphidic sediments may not be as important in ore genesis as current theories suggest.
TL;DR: While there was little evidence for birth weight or gestational age contributing to the difference in ADHD symptoms, there was a strong association between ADHD symptoms and speech and reading problems.
Abstract: Differences between twins and siblings in behaviour problems were investigated in a non-selected sample of 1938 families with children aged 4-12 years. Families were sent a questionnaire based on DSM-III-R criteria for Attention Deficit Hyperactivity Disorder (ADHD), Oppositional Defiant Disorder (ODD), Conduct Disorder (CD) and Separation Anxiety (SA), which was validated by formal clinical interview. The questionnaire also included measures of speech and reading problems. There were significant differences between twins and siblings for ADHD symptoms, but not for symptoms of ODD, CD or SA. Twins and siblings differed significantly for gestational age, birth weight, speech and reading problems. While there was little evidence for birth weight or gestational age contributing to the difference in ADHD symptoms, there was a strong association between ADHD symptoms and speech and reading problems.
TL;DR: The evolutionary development of coral reefs may not be related to light-enhanced calcification resulting from the association of corals with symbiotic algae.
Abstract: The evolutionary development of tropical coral reefs is presently ascribed to the association of corals with symbiotic algae (zooxanthellae) and to the enhancement of calcification by light. Contrary to this idea, the calcification rate in a non-reef-building tropical coral (Tubastrea faulkneri) without symbiotic algae was the same as the light-enhanced rate in a zooxanthellate reef-building coral (Galaxea fascicularis). The mechanisms of calcification, however, differed between the two species. Instead of being “light-enhanced,” calcification in corals with algae was “dark-repressed.” The evolutionary development of coral reefs may therefore not be related to light-enhanced calcification resulting from the association of corals with symbiotic algae.
TL;DR: This paper present an overview and analysis of the claims and counterclaims of competing positions on the kinds of writing tasks that will enable secondary students to learn about science and to demonstrate scientific understanding.
TL;DR: In many features, it appears that humans and, particularly, mice are the weird mammals that break more general mammalian, or even vertebrate rules.
Abstract: ▪ Abstract Marsupials and monotremes, the mammals most distantly related to placental mammals, share essentially the same genome but show major variations in chromosome organization and function. Rules established for the mammalian genome by studies of human and mouse do not always apply to these distantly related mammals, and we must make new and more general laws. Some examples are contradictions to our assumption of frequent genome reshuffling in vertebrate evolution, Ohno's Law of X chromosome conservation, the Lyon Hypothesis of X chromosome inactivation, sex chromosome pairing, several explanations of Haldane's Rule, and the theory that the mammalian Y chromosome contains a male-specific gene with a direct dominant action on sex determination. Significantly, it is not always the marsupials and monotremes (usually considered the weird mammals) that are exceptional. In many features, it appears that humans and, particularly, mice are the weird mammals that break more general mammalian, or even vertebr...
TL;DR: In this paper, three models of regional settlement pattern correlating to different types of chiefdom systems are identified: (1) the centripetal regional system in circumscribed regions representing the most complex chiefdom organizations, (2) the centrifugal regional systems in semi-circumscribed regions indicating less integrated chiefdom organization, and (3) the decentralized regional system indicating competing and the least complex organizations.
TL;DR: Both human and animal studies suggest that MLT has powerful chronobiotic properties and shows considerable promise as a prophylactic and therapeutic alternative or supplement to the use of natural and artificial bright light for resetting the circadian pacemaker.
01 Jan 1996
TL;DR: The high incidence of stress fractures in track and field athletes and the most common sites of bone injuries were the tibia with 12 injuries (46%), followed by the navicular with 4 injuries (15%), and the fibula with 3 injuries (12%).
Abstract: The incidence and distribution of stress fractures were evaluated prospectively over 12 months in 53 female and 58 male competitive track and field athletes (age range, 17 to 26 years). Twenty athletes sustained 26 stress fractures for an overall incidence rate of 21.1%. The incidence was 0.70 for the number of stress fractures per 1000 hours of training. No differences were observed between male and female rates (P > 0.05). Twenty-six stress fractures composed 20% of the 130 musculoskeletal injuries sustained during the study. Although there was no difference in stress fracture incidence among athletes competing in different events (P > 0.05), sprints, hurdles, and jumps were associated with a significantly greater number of foot fractures ; middle- and long-distance running were associated with a greater number of long bone and pelvic fractures (P < 0.05). Overall, the most common sites of bone injuries were the tibia with 12 injuries (46%), followed by the navicular with 4 injuries (15%), and the fibula with 3 injuries (12%). The high incidence of stress fractures in our study suggests that risk factors in track and field athletes should be identified.
TL;DR: This article examined traditional family and independence values among young Vietnamese respondents (N = 204), their perceptions of parents' values, and the impact of differential parent-adolescent acculturation on intergenerational conflict and gender satisfaction.
Abstract: The present study examined traditional family and independence values among young Vietnamese respondents (N = 204), their perceptions of parents' values, and the impact of differential parent-adolescent acculturation on intergenerational conflict and gender satisfaction. The study confirmed that adolescents perceived that they had less traditional values than their parents. Traditional family values diminishedwithtime spent inAustraliawhile the value accordedtoindependence increased. This pattern was stronger for girls than for boys. Girls valued Vietnamese traditions less than did their male peers, regarded their parents as being less accepting of independence, and were more dissatisfied with their gender role than boys. For girls but not for boys, discrepancy between adolescent and parental values was associated with more conflict and greater gender dissatisfaction. This study suggests that girls have more difficulty than boys in dealing simultaneously with the expectations of two cultures. Cette etude ...
TL;DR: The authors reviewed recent research in the area of initial fraction concepts and found that the common goal of the empirical studies which are represented in this analysis was to assist children develop a meaningful understanding of the rational number construct, founded on durable fraction concepts.
Abstract: This paper reviews recent research in the area of initial fraction concepts. The common goal of the empirical studies which are represented in this analysis was to assist children develop a meaningful understanding of the rational number construct, founded on durable fraction concepts. Two interpretations of findings were derived from the research. One group of researchers identified initial fraction concepts emerging from the application of intuitive mechanisms, in particular partitioning in either continuous or discrete contexts, and leading to unit identification and iteration of the unit. The other group of researchers identified ideas of ratio and proportion present in young children's early thoughts about fractions.