993 resultados para Theory of Natural Selection


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This paper examines some of the effects of globalisation on education and teacher education. In particular it considers the contradictory demands of economic and cultural forms of globalisation, and between globalisation and localisation. Attempts to construct an 'education space' in Europe and Asia are considered and various responses of teacher education systems are outlined. A defensible theory of teacher education is presented around the transformation of curriculum, pedagogy, assessment and the practicum: one that might allow a creative response to the contradictions of globalisation.

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Nanoparticies have been widely used to enhance the properties of natural rubber (NR). In the present paper a novel nanocomposite was developed by blending nano-ZnO slurry with prevulcanized NR latex, and the thermal degradation process of pure NR and NR/ZnO nanocomposites with different nano-ZnO loading was studied with a Perkin Elemer TGA-7 thermogravimetric analyzer. The thermal degradation parameters of NR/ZnO (2 parts ZnO per hundred dlY rubber) at different heating rates (Bs) were studied. The results show that the thermal degradation of pure NR and NR/ZnO nanocomposites in nitrogen is a one-step reaction. The degradation temperatures of NR/ZnO nanocomposite increase with an increasing B. The peak height (Rp) on the differential thermogravimetric curve increases with the increase of B. The degradation rates are not affected significantly by B, and the average values of thermal degradation rate Cp and Cf are 44.42 % and 81.04 %, respectively. The thermal degradation kinetic parameters are calculated with Ozawa-Flynn-Wall method. The activation energy (E) and the frequency factor (A) vary with ecomposition degree, and can be divided into three phases corresponding to the volatilization of low-molecular-weight materials, the thermal degradation ofNR main chains and the decomposition of residual carbon.

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Aim: To develop a grounded theory of nursing’s contribution to patient rehabilitation from the perspective of nurses working in inpatient rehabilitation.

Design:
Grounded theory method, informed by the theoretical perspective of symbolic interactionism, was used to guide data collection and analysis, and the development of a grounded theory.

Setting:
Five inpatient rehabilitation units in Australia.

Participants:
Thirty-five registered and 18 enrolled nurses participated in audio-taped interviews and/or were observed during periods of their everyday practice.

Findings:
The analysis revealed a situation whereby nurses made decisions about when to ‘opt in’ and when to ‘opt out’ of inpatient rehabilitation. This occurred on two levels: with their interaction with patients and allied health professionals, and when faced with negative system issues that impacted on their ability to contribute to patient rehabilitation. The primary contribution nurses made to inpatient rehabilitation was working directly with patients, enabling them to self-care. Nurses coached patients when their decisions about ‘opting in’ and ‘opting out’ were based on assessment of the person in their particular context. In contrast, the nurses mostly distanced themselves from system-based problems, ‘opting out’ of addressing them. They did this not to make their working lives easier, but more manageable.

Conclusion:
System-based problems impacted negatively on the nurses’ ability to deliver comprehensive rehabilitation care. As a consequence, some nurses felt unable to influence the care and they withdrew professionally to make their work lives more manageable.

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In this exchange, Peter Coghlan and Nick Trakakis discuss the problem of natural evil in the light of the recent Asian tsunami disaster. The exchange begins with an extract from a newspaper article written by Coghlan on the tsunami, followed by three rounds of replies and counter-replies, and ending with some final comments from Trakakis. While critical of any attempt to show that human life is good overall despite its natural evils, Coghlan argues that instances of natural evil, even horrific ones, can be justified as the unavoidable by-product of a natural system on which human life and culture depends. Trakakis, however, rejects this view, counselling instead a degree of skepticism about our ability to construct a plausible theodicy for horrific evil.

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This paper examines the temporal concepts that underlie the theory of transference in psychoanalysis. The paper reviews Freud's rejection of linear temporality as characteristic of unconscious thought in favour of regression, repetition, and deferred action. It then develops concepts drawn from Jacques Lacan's theory of the formation of the ego. Here, the biologically determined helplessness derived from the human prematurity of birth becomes transformed into an ego that anticipates subjective unity. The paper then moves on to the more complex theory of the temporality implied in subject formation, offered in Lacan's later theory of separation. Implications are drawn for the use and understanding of transference in the practice of psychoanalysis via clinical examples. In addition, Lacan's ideas on subject formation are proposed as an extension and clarification of previous psychoanalytic theories of development.

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This paper will develop a specific reading of Julia Kristeva’s analysis of the Mother in psychoanalytic contexts and artistic production. I want to suggest a particular connection between the Mother and a second figure closely associated with her: the Midwife. Such a move opens up the possibility for a new understanding of Kristeva’s correlation of the Mother with the psychoanalytic concept of “abjection”. I wish to identify the Midwife as the crucial intersection of a masculine and feminine subjectivity. I will undertake this project via a historical study of Midwifery, which will include an exploration of the Midwife’s relationship to masculine ideologies of medical thought, as well as an account of the problematic rise of the “Man-Midwife”. My strategy will be to extend the submerged historical and material content of Kristeva’s own theories, with particular reference to Powers of Horror: An Essay on Abjection.

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The Osoyoos Indian Band case study signals the beginning of a PhD research project that will take approximately three years to complete. Taken in isolation, the objectives for the Osoyoos case study are modest. We want to refine our theoretical model and improve the case study protocol before embarking on a set of 5 case studies to explore Indigenous entrepreneurship; what it is, what communities do to succeed and a generalized definition of a successful venture from an Indigenous Canadian perspective.

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This paper describes the feasibility study on the application of passive and active stack systems to enhance natural ventilation in public housing in Singapore. About 86% of the population is staying in high-rise public housing, known as Housing and Development Board (HDB) flats, which is designed for natural ventilation. The primary objective of this work is to assess the status of natural ventilation in a typical four-room HDB flat using scaled model in the wind tunnel, and to develop an effective passive or active stack system to enhance natural ventilation in the flat. Four numbers of stacks with different sizes were tested at two locations in the flat. The study shows that the passive stack, incorporating the principle of airflow due to buoyancy, does not enhance air velocity in the flat. However, the active stack which operates based on the suction effect induced by a fan fixed at the top of the stack leads to substantial increase in the air velocity at the room and thus meeting the human’s thermal comfort condition. It was noted that the velocities increase along with the increase in the stack size.

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Sexual selection is thought to be opposed by natural selection such that ornamental traits express a balance between these two antagonistic influences. Phenotypic variation among populations may indicate local shifts in this balance, or that different stable ‘solutions’ are possible, but testing these alternatives presents a major challenge. In the guppy (Poecilia reticulata), a small freshwater fish with male-limited ornamental coloration, these issues can be addressed by transplanting fish among sites of varying predation pressure, thus effectively manipulating the strength and nature of natural selection. Here, we contrast the evolutionary outcome of two such introductions conducted in the Trinidadian El Cedro and Aripo Rivers. We use sophisticated colour appraisal methods that account for full spectrum colour variation and which incorporate the very latest visual sensitivity data for guppies and their predators. Our data indicate that ornamentation evolved along different trajectories: whereas Aripo males evolved more numerous and/or larger orange, black and iridescent markings, El Cedro males only evolved more extensive and brighter iridescence. Examination of the El Cedro experiment also revealed little or no ornamental evolution at the control site over 29 years, which contrasts markedly with the rapid (approx. 2–3 years) changes reported for introduction populations. Finally, whole colour-pattern analysis suggested that the greatest visual difference between El Cedro introduction and control fish would be perceived by the two most salient viewers: guppies and the putatively dangerous predator Crenicichla alta. We discuss whether and how these evolutionary trajectories may result from founder effects, population-specific mate preferences and/or sensory drive.

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Heat transfer by natural convection in triangular enclosures is an area of significant importance in applications such as the design of greenhouses, attics and solar water heaters. However, given its significance to these areas it has not been widely examined. In this study, the natural convection heat transfer coefficients in an attic shaped enclosure were determined for Grashof Numbers over the range 107 to 109. It was found that the measured heat transfer coefficients could be predicted to within 5% by Ridouane and Campo’ (2005) equation (Eqn. 1) for natural convection in a triangular enclosure previously developed for Grashof Numbers in the range 105 to 106.

Nu=0.286*A-0.286*Gr1/4 (Eqn. 1)

As such, it is suggested that this equation may be suitable for predicting the natural convection heat transfer coefficients in full scale attic enclosures.

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There is growing awareness of the benefits of rehabilitation both in Australia and overseas. While the provision of rehabilitation services is not new, recognition of this type of health service as an integral part of health care has been linked to changes in the provision of acute care services, advances in medical technology, improvements in the management of trauma and an ageing population. Despite this, little attention has been paid to nursing's contribution to patient rehabilitation in Australia. The aim of this grounded theory study, therefore, was to collect and analyse nurses' reports of their contributions to patient rehabilitation and to describe and analyse contextual factors influencing that contribution. Data were collected during interviews with registered and enrolled nurses working in five inpatient rehabilitation units in New South Wales and during observation of the nurses' everyday practice. A total of 53 nurses participated in the study, 35 registered nurses and 18 enrolled nurses. Grounded theory, informed by the theoretical perspective of symbolic interactionism, was used to guide data analysis, the ongoing collection of data and the generation of a substantive theory. The findings revealed six major categories. One was an everyday problem labelled incongruence between nurses' and patients' understandings and expectations of rehabilitation. Another category, labelled coaching patients to self-care, described how nurses independently negotiated the everyday problem of incongruence. The remaining four categories captured conditions in the inpatient context which influenced how nurses could contribute to patient rehabilitation. Two categories, labelled segregation: divided and dividing work practices between nursing and allied health and role ambiguity, were powerful in shaping nursing's contribution as they acted individually and synergistically to constrain nursing's contribution to patient rehabilitation. The other two categories, labelled distancing to manage systemic constraints and grasping the nettle to realise nursing's potential, represent the mutually exclusive strategies nurses used in response to segregation and role ambiguity. From exploration of the relationship between the six categories, the core category and an interactive grounded theory called opting in and opting out emerged. In turn, this grounded theory reveals nursing's contribution to inpatient rehabilitation as well as contextual conditions constraining that contribution. The significance of these findings is made manifest through their contribution to the advancement of nursing knowledge and through implications for nursing practice and education, rehabilitation service delivery and research.