57 resultados para rational points

em Deakin Research Online - Australia


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The accumulated oxygen deficit (AOD) method assumes a linear VO<sub>2</sub>-power relationship for exercise intensities increasing from below the lactate threshold (BLT) to above the lactate threshold (ALT). Factors that were likely to effect the linearity of the VO<sub>2</sub>-power regression and the precision of the estimated total energy demand (ETED) were investigated. These included the slow component of VO<sub>2</sub> kinetics (SC), a forced resting y-intercept and exercise intensities BLT and ALT. Criteria for linearity and precision included the Pearson correlation coefficient (PCC) of the VO<sub>2</sub>-power relationship, the length of the 95% confidence interval (95% CI) of the ETED and the standard error of the predicted value (SEP), respectively. Eight trained male and one trained female triathlete completed the required cycling tests to establish the AOD when pedalling at 80 rev/min. The influence of the SC on the linear extrapolation of the ETED was reduced by measuring VO<sub>2</sub> after three min of exercise. Measuring VO<sub>2</sub> at this time provided a new linear extrapolation method consisting of ten regression points spread evenly from BLT and ALT. This method produced an ETED with increased precision compared to using regression equations developed from intensities BLT with no forced y-intercept value; (95%CI (L), 0.70±0.26 versus 1.85±1.10, P<0.01; SEP(L/Watt), 0.07±0.02 versus 0.28±0.17; P<0.01). Including a forced y-intercept value with five regression points either BLT or ALT increased the precision of estimating the total energy demand to the same level as when using 10 regression points, (5 points BLT + y-intercept versus 5 points ALT + y-intercept versus 10 points; 95%CI(l), 0.61±0.32, 0.87±0.40, 0.70±0.26; SEP(L/Watt), 0.07±0.03, 0.08±0.04, 0.07±0.02; p>0.05). The VO<sub>2</sub>-power regression can be designed using a reduced number of regression points... ABSTRACT FROM AUTHOR

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The International Obesity Taskforce (IOTF) recommends using age- and gender-specific body mass index (BMI) cut-points for defining the prevalence of overweight and obesity in children. These are given in both 6- and 12-month age intervals. Since the BMI-for-age curves are nonlinear, a degree of bias will be introduced when age intervals are wide. We aimed to quantify this bias in prevalence estimates in 2178 Australian children aged 4-12 years using 12- versus 6-month age intervals. Using the 12-month interval, the prevalence of overweight and obesity was underestimated by 1.4% compared to the 6-month interval estimates; however, this was age-dependent. It overestimated prevalence for 4-year olds, but underestimated it for older ages by up to 2.6%. Overweight prevalence was generally affected more than obesity prevalence. The use of different age intervals for IOTF cut-points introduces a small but systematic bias in prevalence estimates of overweight and obesity.

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This paper considers Bourdieu's concepts of perspectivism and reflexivity, looking particularly at how he develops arguments about these in his recent work, The Weight of the World (1999) and Pascalian Meditations (2000b). We explicate Bourdieu's distinctive purposes and deployment of these terms and approaches, and discuss how this compares with related methodological and theoretical approaches currently found in social and feminist theory. We begin by considering three main ways in which 'reflexivity' is deployed in current sociological writing, distinguishing between reflexive sociology and a sociology of reflexivity. This is followed by a discussion of the main aspects of Bourdieu's approach to 'reflexive sociology' and its relation to his concepts of social field, perspectivism and spaces of point of view. He argues that we need to interrogate the idea of a single 'perspective' and account especially for the particularity and influence of the 'scholastic' point of view. He characterizes this latter point of view as unaware of its own historicity and as largely concerned with contemplation and with treating ideas primarily as abstractions (Bourdieu, 2000b). Bourdieu's intervention is to argue, as he has throughout his work, for a more reflexive account of one's location and habitus, and for sustained engagement with ideas and social issues as practical problems. Bourdieu exhorts researchers to work with 'multiple perspectives' (Bourdieu et al., 1999, p. 3), the various competing 'spaces of points of view', without collapsing into subjectivism or relativism. We then consider recent feminist engagements with and critiques of Bourdieu's notion of reflexivity and chart some of the main points of contention regarding its relevance and conceptual potential for theorizing gender identities and transformations in current times. We conclude with a brief outline of how we are working with a reflexive sociological approach in a cross-generational study of young women in difficult circumstances, 'on the margins' of education and work.

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The authors used grounded theory to explore and develop a substantive theory to explain how 20 young women with type 1 diabetes managed their lives when facing turning points and undergoing transitions. The women experienced a basic social problem: being in the grip of blood glucose levels (BGLs), which consisted of three categories: (a) the impact of being susceptible to fluctuating BGLs, (b) the responses of other people to the individual woman’s diabetes, and (c) the impact of the individual women’s diabetes on other people’s lives. The women used a basic social process to overcome the basic social problem by creating stability, which involved using three interconnected subprocesses: forming meaningful
relationships, enhancing attentiveness to blood glucose levels, and putting things in perspective. Insights into the processes and strategies used by the women have important implications for provision of care and service delivery.

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Teacher/Student engagement enriches learning experiences beyond the specifics of communicated information by encouraging connectivity and the fostering of learning communities. This paper is an analysis of student engagement in a postgraduate online-mediated learning environment, and considers how engagement may be an important factor in building communities of learning in conjunction with improved learning outcomes. This paper is informed by the conceptual framework for effective e-learning outlined by Garrison and Anderson (2003) as necessary for higher order knowledge building by students as part of skills development for participation in knowledge economies. Data collected through a pilot study infers that a correlation exists between the development of small groups of significantly contributing students within wider online student cohorts and the learning outcomes of all students within the cohort. The findings indicate that a number of small events have increased student engagement and motivation, and resulted in improved learning outcomes.

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Background
Studies support the positive effects that Tai Chi has on the physical health of older adults. However, many older adults residing in long-term care facilities feel too weak to practice traditional Tai Chi, and a more simplified style is preferred.
Objective
To test the effects of a newly-developed, Simplified Tai-Chi Exercise Program (STEP) on the physical health of older adults who resided in long-term care facilities.
Design
A single group design with multiple time points: three pre-tests, one month apart; four post-tests at one month, two months, three months, and six months after intervention started.
Settings
Two 300–400 bed veteran homes in Taiwan.
Participants
The 51 male older adults were recruited through convenience sampling, and 41 of them completed six-month study. Inclusion criteria included: (1) aged 65 and over; (2) no previous training in Tai Chi; (3) cognitively alert and had a score of at least eight on the Short Portable Mental Status Questionnaire; (4) able to walk without assistance; and (5) had a Barthel Index score of 61 or higher. Participants who had dementia, were wheel-chair bound, or had severe or acute cardiovascular, musculoskeletal, or pulmonary illnesses were excluded.
Methods
The STEP was implemented three times a week, 50 min per session for six months. The outcome measures included cardio-respiratory function, blood pressure, balance, hand-grip strength, lower body flexibility, and physical health actualization.
Results
A drop in systolic blood pressure (p=.017) and diastolic blood pressure (p<.001) was detected six months after intervention started. Increase in hand-grip strength from pre to post intervention was found (left hand: p<.001; right hand: p=.035). Participants also had better lower body flexibility after practicing STEP (p=.038).
Conclusions
Findings suggest that the STEP be incorporated as a floor activity in long-term care facilities to promote physical health of older adults.

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Background and Purpose: Sleep quality seems to be an antecedent to depressive symptoms during pregnancy. We sought to 1) examine the psychometrics of the Pittsburgh Sleep Quality Index (PSQI) in pregnancy; 2) examine whether sleep quality predicted increases in depressive symptoms; and 3) compare PSQI scores across 3 or 2 levels of depressive symptoms.

Methods: Each of the 252 participants completed the Beck Depression Inventory (short form) and a sleep quality measure at mid and late pregnancy.

Results: PSQI total scores showed good internal consistency and construct validity. An improved model of the internal structure of the PSQI in pregnancy was found with 1 factor labeled Sleep Efficiency, a second labeled Night and Daytime Disturbances, and an Overall Sleep Quality component associated with, but separate from, both of these 2 factors. Although PSQI scores showed moderate stability over time, sleep disturbance scores increased in late pregnancy. Importantly, PSQI prospectively predicted increases in depressive symptoms.

Conclusions:
Findings suggest that the PSQI is useful in pregnancy research. Findings also support the idea that sleep problems are prospective risk factors for increases in depressive symptoms during pregnancy. Practitioners are advised to screen for sleep quality during early pregnancy.

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The field of adult literacy and basic education (ALBE) has undergone dramatic changes in recent years with the advent of labour market programs, accreditation, competency-based assessment and competitive tendering for program funds. Teachers' working conditions have deteriorated and their professional autonomy has been eroded. ALBE has been increasingly instrumentalised to fulfil the requirements of a marketised economy and conform to its norms. The beliefs and value systems which traditionally underpinned the work of ALBE teachers have been reframed according to the principle of 'performativity' and the demands of the 'performative State' (Lyotard, 1984: 46, Yeatman 1994: 110). The destabilisation of teachers' working lives can be understood as a manifestation of the 'postmodern condition' (Lyotard 1984; Harvey 1989): the collapse of the certainties and purposes of the past; the proliferation of technologies; the impermanence and intensification of work; the commodification of knowledge and curricula; and the dissolving of boundaries between disciplines and fields of knowledge. The critiques of the modernist grand narratives which underpin progressivist and critical approaches to adult literacy pedagogy have further undermined the traditional points of reference of ALBE teachers. In this thesis I examine how teachers are teaching, surviving, resisting, and 'living the contradictions' (Seddon 1994) in the context of struggles to comply with and resist the requirements of performativity. Following Foucault and a number of feminist poststructuralist authors, I have applied the notions of 'discursive engagement' and 'the politics of discourse' (Yeatman 1990a) as a way of theorising the interplay between imposed change and teachers' practice. I explore the discursive practices which take place at the interface between the 'new' policy discourses and older, naturalised discourses; how teachers are engaged by and are engaging with discourses of performativity; how teachers are discursively constructing adult literacy pedagogy; what new, hybrid discourses of 'good practice' are emerging; and the micropractices of resistance which teachers are enacting in their speech and in their practice. My purpose was to develop knowledge which would support the reflexivity of teachers; to enrich the theoretical languages that teachers could draw upon in trying to make sense of their situation; and to use those languages in speaking about the dilemmas of practice. I used participatory action research as a means of producing knowledge about teachers' practices, structured around their agency, and reflecting their standpoint (Harding 1993). I describe two separate action research projects in which teachers of ALBE participated. I reflect on both projects in the light of poststructuralist theory and consider them as instances of what Lather calls 'within/against research' (Lather 1989: 27). I analyse written and spoken texts produced in both projects which reflect teachers' responses to competency-based assessment and other features of the changing context. I use a method of discourse mapping to describe the discursive field and the teachers' discursive practices. Three main configurations of discourse are delineated: 'progressivism', 'professional teacher' and 'performativity'. The teachers mainly position themselves within a hybridising 'progressivist /professional teacher' discourse, as a discourse of resistance to 'performative' discourse. In adapting their pedagogies, the teachers are in some degree taking the language and world view of performativity into their own vocabularies and practices. The discursive picture I have mapped is complex and contradictory. On one hand, the 'progressivist /professional teacher' discourse appears to endure and to take strength from the articulation into it of elements of performative discourse, creating new possibilities for discursive transformation. On the other hand, there are signs that performative discourse is colonising and subsuming progressivist /professional teacher discourse. At times, both of these tendencies are apparent in the one text. Six micropractices of resistance are identified within the texts: 'rational critique', 'objectification', 'subversion', 'refusal', 'humour' and 'the affirmation of desire'. These reflect the teachers' agency in making discursive choices on the micro level of their every day practices. Through those micropractices, the teachers are engaging with and resisting the micropractices and meanings of performativity. I apply the same multi-layered method of analysis to an examination of discursive engagement in pedagogy by analysing a transcript of the teachers' discussion of critical incidents in their classrooms. Their classroom pedagogies are revealed as complex, situated and eclectic. They are combining and integrating their 'embodied' and their 'institutional' powers, both 'seducing' (McWilliam 1995) and 'regulating' (Gore 1993) as they teach. A strong ethical project is apparent in the teachers' sense of social responsibility, in their determination to adhere to valued traditions of previous times, and in their critical self-awareness of the ways in which they use their institutional and embodied powers in the classroom. Finally, l look back on the findings, and reflect on the possibilities of discursive engagement and the politics of discourse as a framework for more strategic practice in the current context. This research provides grounds for hope that, by becoming more self-conscious about how we engage discursively, we might become more strategic in our everyday professional practice. Not withstanding the constraints (evident in this study) which limit the strategic potential of the politics of discourse, there is space for teachers to become more reflexive in their professional, pedagogical and political praxis. Development of more deliberate, self-reflexive praxis might lead to a 'postmodern democratic polities' (Yeatman 1994: 112) which would challenge the performative state and the system of globalised capital which it serves. Short abstract Adult literacy and basic education (ALBE) teachers have experienced a period of dramatic policy change in recent years; in particular, the introduction of competency-based assessment and competitive tendering for program funds. 'Discourse politics' provides a way of theorising the interplay between policy-mediated institutional change and teachers' practice. The focus of this study is 'discursive engagement'; how teachers are engaged by and are engaging with discourses of performativity. Through two action research projects, texts were generated of teachers talking and writing about how they were responding to the challenges, and developing their pedagogies in the new policy environment. These texts have been analysed and several patterns of discursive engagement delineated, named and illustrated. The strategic potential of 'discourse polities' is explored in the light of the findings.

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The main theme of this thesis is that there is a common structural basis for drugs acting on the central nervous system (CNS), and that this concept may be used to design new CNS-active drugs which have greater specificity and hence less side-effects. To develop these ideas, the biological basis of how drugs modify CMS neurotransmission is described, and illustrated using dopaminergic pathways. An account is then given of the use of physicochemical concepts in contemporary drug design. The complete conformational analysis of several antipsychotic drugs is used to illustrate some of these techniques in the development of a model for antipsychotic drug action. After reviewing current structure-activity studies in several classes of CNS drugs (antipsychotics, anti-depressants, stimulants, hal1ucinogens, anticonvulsants and analgesics), a hypothesis for a common structural basis of CNS drug action is proposed- This is based on a topographical comparison of the X-ray structures of eight representative CNS-active drugs, and consists of three parts: 1.there is a common structural basis for the activity of many different CNS-active drug classes; 2. an aromatic ring and a nitrogen atom are the primary binding groups whose topographical arrangement is fundamental to the activity of these drug classes; 3. the nature and placement of secondary binding determines different classes of CNS drug activity. A four-Point model for this common structural basis is then defined using 14- CNS-active drug structures that include the original eight used in proposing the hypothesis. The coordinates of this model are: R1 (0. 3.5, 0), R2 (0, -3.5, O), N (4.8. -0.3, 1.4), and R3 (6.3, 1.3, 0), where R1 and R2 represent the point locations of a hydrophobic interaction of the common aromatic ring with a receptor, and R3 locates the receptor point for a hydrogen bond involving the common nitrogen, N. Extended structures were used to define the receptor points R1, R2 and R3, and the complete conformational space of each of the 14 molecules was considered. It is then shoun that the model may be used to predict whether a given structure is likely to show CNS activity: a search over 1,000 entries in the current Merck Index shows a high probability (82%) of CNS activity in compounds fitting the structural model. Analysis of CNS neurotransmitters and neuropeptides shows that these fit the common model well. Based on the available evidence supporting chemical evolution, protein evolution, and the evolution of neurotransmitter functions, it is surmised that the aromatic ring/nitrogen atom pharmacophore proposed in the common model supports the idea of the evolution of CNS receptors and their neurotransmitters, possibly from an aromatic amine or acety1cho1ine acting as a primaeval communicating molecule. The third point in the hypothesis trilogy is then addressed. The extensive conformation-activity analyses that have resulted in well-defined models for five separate CNS drug classes are used to map out the locations of secondary binding groups relative to the common model for anti-psychotics, antidepressants, analgesics, anticholinergics, and anticonvulsants. With this information, and knowledge derived from receptor-binding data, it is postulated that drugs having specified activity could be designed. In order to generate novel structures having a high probability of CNS-activity, a process of drug design is described in which known CNS structures are superimposed topographically using the common model as a template. Atoms regarded as superfluous may be selectively deleted and the required secondary binding groups added in predicted locations to give novel structures. It is concluded that this process provides the basis for the rational design of new lead compounds which could further be optimized for potent and specific CNS activity.

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The relationship among psychosocial stress, coping and metabolic control has a key effect on diabetes clinical outcomes and mental health. Life transitions are peak times of major change within personal and social contexts, which add stress affecting on peoples? problem solving. The thesis describes young women with Type 1 diabetes? perspectives of the problems encountered and how they managed them when they faced turning points and made life transitions. The study identified the women?s health concerns and factors that enhanced or hindered their ability to manage turning points and transitions. A substantive theory that comprised a problem of ?being in the grip of blood glucose levels? (BGLs) and a process termed ?creating stability? to manage life transitions was developed. The state of being in the grip of BGLs was associated with the impact of fluctuating BGLs; responses of other people to the womens? diabetes and the impact of diabetes on other people?s lives. The women managed these problems by engaging in social and psychological strategies helping them to stabilised their lives and feel more in control during life transitions.

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There is little strong evidence that currently recommended higher waist circumference cut-points for Europids compared with South Asians are associated with similar risk for type 2 diabetes. This study was designed to provide such evidence. Longitudinal studies over 5 years were conducted among 5,515 Europid and 2,214 ethnically South Asian participants. Age-standardized diabetes incidence at different levels of waist circumference and incidence difference relative to a reference value were calculated. The Youden Index was used to determine waist circumference cut-points. At currently recommended cut-points, estimated annual diabetes incidence for a 50-year-old Europid was <0.6% for both sexes, and for a 50-year-old South Asian, 5.8% for men and 2.1% for women. Annual diabetes incidence of 1% was observed for a 50 year old at a waist circumference 35–40 cm greater in Europid compared to South Asian men and women. Incidence difference between recommended cut-points and a reference value (80 cm in men, 70 cm in women) was 0.3 and 4.4% per year for Europid and South Asian men, and 0.2 and 0.8% per year for Europid and South Asian women, respectively. Waist circumference cut-points chosen using the Youden Index were shown to be dependent on obesity levels in the population. The much higher observed risk of diabetes in South Asians compared to Europids at the respective recommended waist circumference cut-points suggests that differences between them should be greater. Approaches that use the Youden Index to select waist circumference cut-points are inappropriate and should not be used for this purpose.