741 resultados para self-regulated learners
Resumo:
Next-generation autonomous underwater vehicles (AUVs) will be required to robustly identify underwater targets for tasks such as inspection, localization, and docking. Given their often unstructured operating environments, vision offers enormous potential in underwater navigation over more traditional methods; however, reliable target segmentation often plagues these systems. This paper addresses robust vision-based target recognition by presenting a novel scale and rotationally invariant target design and recognition routine based on self-similar landmarks that enables robust target pose estimation with respect to a single camera. These algorithms are applied to an AUV with controllers developed for vision-based docking with the target. Experimental results show that the system performs exceptionally on limited processing power and demonstrates how the combined vision and controller system enables robust target identification and docking in a variety of operating conditions.
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A "self-exciting" market is one in which the probability of observing a crash increases in response to the occurrence of a crash. It essentially describes cases where the initial crash serves to weaken the system to some extent, making subsequent crashes more likely. This thesis investigates if equity markets possess this property. A self-exciting extension of the well-known jump-based Bates (1996) model is used as the workhorse model for this thesis, and a particle-filtering algorithm is used to facilitate estimation by means of maximum likelihood. The estimation method is developed so that option prices are easily included in the dataset, leading to higher quality estimates. Equilibrium arguments are used to price the risks associated with the time-varying crash probability, and in turn to motivate a risk-neutral system for use in option pricing. The option pricing function for the model is obtained via the application of widely-used Fourier techniques. An application to S&P500 index returns and a panel of S&P500 index option prices reveals evidence of self excitation.
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This paper proposes how ecological dynamics, a theory focusing on the performer-environment relationship, provides a basis for understanding skill acquisition in sport. From this perspective, learners are conceptualized as complex, neurobiological systems in which inherent self-organisation tendencies support the emergence of adaptive behaviours under a range of interacting task and environmental constraints. Intentions, perceptions and actions are viewed as intertwined processes which underpin functional movement solutions assembled by each learner during skill acquisition. These ideas suggest that skill acquisition programmes need to sample information from the performance environment to guide behaviour in practice tasks. Skill acquisition task protocols should allow performers to use movement variability to explore and create opportunities for action, rather than constraining them to passively receiving information. This conceptualisation also needs to characterize the design of talent evaluation tests, which need to faithfully represent the perception-action relationships in the performance environment. Since the dynamic nature of changing task constraints in sports cannot be predicted over longer timescales, an implication is that talent programmes should focus on developing performance expertise in each individual, rather than over-relying on identification of expert performers at specific points in time.
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BACKGROUND Chemotherapy-induced nausea and vomiting (CINV) remain prevalent among cancer patients despite pharmacological advances in CINV therapy. Patients can initiate nonpharmacologic strategies, which potentially play an important role as adjuncts to pharmacological agents in alleviating CINV. Some studies have explored nausea and vomiting self-management (NVSM) behaviors among patients in Western settings; however, little is known about the NVSM behaviors of patients in China. OBJECTIVES This study examines NVSM behaviors of Chinese cancer patients. METHODS A cross-sectional survey was conducted in a specialist cancer hospital in southeast China. RESULTS A sample of 255 cancer patients was recruited. A mean of 8.56 (±3.15) NVSM behaviors was reported. Most NVSM behaviors were rated as moderately effective and were implemented with moderate self-efficacy. Higher distress levels, better functional status, previous similar symptom experiences, receiving chemotherapy as an inpatient, and greater support from multiple levels were related to greater engagement in NVSM; higher self-efficacy levels pertaining to NVSM behaviors were associated with reports of more relief from specific NVSM behaviors. CONCLUSIONS A range of NVSM strategies was initiated by Chinese cancer patients and provided some relief. A range of individual, health status, and environmental factors influenced engagement with and relief from NVSM behaviors. IMPLICATIONS FOR PRACTICE To enhance Chinese patients' NVSM, patients should be supported to engage in behaviors including taking antiemetics, modifying their diet, using psychological strategies, and creating a pleasant environment. The findings highlight the importance of enhancing patients' self-efficacy in NVSM, alleviating symptom distress, and improving social support to achieve better outcomes.
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The nanostructured surface of biomaterials plays an important role in improving their in vitro cellular bioactivity as well as stimulating in vivo tissue regeneration. Inspired by the mussel’s adhesive versatility, which is thought to be due to the plaque–substrate interface being rich in 3,4-dihydroxy-L-phenylalamine (DOPA) and lysine amino acids, in this study we developed a self-assembly method to prepare a uniform calcium phosphate (Ca-P)/polydopamine composite nanolayer on the surface of b-tricalcium phosphate (b-TCP) bioceramics by soaking b-TCP bioceramics in Tris–dopamine solution. It was found that the addition of dopamine, reaction temperature and reaction time are three key factors inducing the formation of a uniform Ca-P/polydopamine composite nanolayer. The formation mechanism of a Ca-P/polydopamine composite nanolayer involved two important steps: (i) the addition of dopamine to Tris–HCl solution decreases the pH value and accelerates Ca and P ionic dissolution from the crystal boundaries of b-TCP ceramics; (ii) dopamine is polymerized to form self-assembled polydopamine film and, at the same time, nanosized Ca-P particles are mineralized with the assistance of polydopamine, in which the formation of polydopamine occurs simultaneously with Ca-P mineralization (formation of nanosized microparticles composed of calcium phosphate-based materials), and finally a self-assembled Ca-P/polydopamine composite nanolayer forms on the surface of the b-TCP ceramics. Furthermore, the formed self-assembled Ca-P/polydopamine composite nanolayer significantly enhances the surface roughness and hydrophilicity of b-TCP ceramics, and stimulates the attachment, proliferation, alkaline phosphate (ALP) activity and bone-related gene expression (ALP, OCN, COL1 and Runx2) of human bone marrow stromal cells. Our results suggest that the preparation of self-assembled Ca-P/polydopamine composite nanolayers is a viable method to modify the surface of biomaterials by significantly improving their surface physicochemical properties and cellular bioactivity for bone regeneration application.
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Objective: The objective of the study was to explore whether and how rural culture influences type II diabetes management and to better understand the social processes that rural people construct in coping with diabetes and its complications. In particular, the study aimed to analyse the interface and interactions between rural people with type II diabetes and the Australian health care system, and to develop a theoretical understanding that reflects constructs that may be more broadly applicable. Methods: The study applied constructivist grounded theory methods within an interpretive interactionist framework. Data from 39 semi-structured interviews with rural and urban type II diabetes patients and a mix of rural health care providers were analysed to develop a theoretical understanding of the social processes that define diabetes management in that context. Results: The analysis suggests that although type II diabetes imposes limitations that require adjustment and adaptation, these processes are actively negotiated by rural people within the environmental context to fit the salient social understandings of autonomy and self-reliance. Thus, people normalized self-reliant diabetes management behaviours because this was congruent with the rural culture. Factors that informed the actions of normalization were relationships between participants and health care professionals, support, and access to individual resources. Conclusions: The findings point to ways in which rural self-reliance is conceived as the primary strategy of diabetes management. People face the paradox of engaging with a health care system that at the same time maximizes individual responsibility for health and minimizes the social support by which individuals manage the condition. The emphasis on self-reliance gives some legitimacy to a lack of prevention and chronic care services. Success of diabetes management behaviours is, however, contingent on relative resources. Where there is good primary care, there develops a number of downstream effects including a sense of empowerment to manage difficult rural environmental circumstances. This has particular bearing on health outcomes for people with fewer resources.
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Aim There is a growing population of people with cancer who experience physiological and psychological effects that persist long after treatment is complete. Interventions that enhance survivors’ self-management abilities might help offset these effects. The aim of this pilot study was to develop, implement and evaluate interventions tailored to assist patients to manage post-treatment health issues effectively. Method In this pre-post intervention cohort study, participants were recruited on completion of cancer treatment. Participants recruited preimplementation, who received usual care, comprised the control group. Participants recruited later formed the intervention group. In the intervention group, the Cancer Care Coordinator developed an individualised, structured Cancer Survivor Self-management Care Plan. Participants were interviewed on completion of treatment (baseline) and at three months. Assessments concerned health needs (CaSUN), self-efficacy in adjusting and coping with cancer and health-related quality of life (FACIT-B or FACT-C). The impact of the intervention was determined by independent t-tests of change scores. Results The intervention (n = 32) and control groups (n = 35) were comparable on demographic and clinical characteristics. Sample mean age was 54 + 10 years. Cancer diagnoses were breast (82%) and colorectal (18%). Statistically significant differences (p < 0.05) indicated improvement in the intervention group for: (a) functional well-being, from the FACIT, (Control: M = −0.69, SE = 0.91; Intervention: M = 3.04, SE = 1.13); and (b) self-efficacy in maintaining social relationships, (Control: M = −0.333, SE = 0.33; Intervention: M = 0.621, SE = 0.27). No significant differences were found in health needs, other subscales of quality of life, the extent and number of strategies used in coping and adjusting to cancer and in other domains of self-efficacy. Conclusions While the results should be interpreted with caution, due to the non-randomised nature of the study and the small sample size, they indicate the potential benefits of tailored self-management interventions warrant further investigation in this context.
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Purpose Self-gifting is a performative process in which consumers purchase products for themselves. The literature to date remains silent on a determination and connection between the extents of post-purchase regret resulting from self-gifting behavior. The purpose of this paper is to examine identification and connection of self-gifting antecedents, self-gifting and the effect on post purchase regret. Design/methodology/approach This study claims the two antecedents of hedonistic shopping and indulgence drive self-gifting behaviors and the attendant regret. A total of 307 shoppers responded to a series of statements concerning the relationships between antecedents of self-gifting behavior and the effect on post-purchase regret. Self-gifting is a multi-dimensional construct, consisting of therapeutic, celebratory, reward and hedonistic imports. Confirmatory factor analysis and AMOS path modeling enabled examination of relationships between the consumer traits of hedonistic shopping and indulgence and the four self-gifting concepts. Findings Hedonic and indulgent shoppers engage in self-gifting for different reasons. A strong and positive relationship was identified between hedonic shoppers and reward, hedonic, therapeutic and celebratory self-gift motivations. hedonic shoppers aligned with indulgent shoppers who also engaged the four self-gifting concepts. The only regret concerning purchase of self-gifts was evident in the therapeutic and celebratory self-gift motivations. Research limitations/implications A major limitation was the age range specification of 18 to 45 years which meant the omission of older generations of regular and experienced shoppers. This study emphasizes the importance of variations in self-gift behaviors and of post-purchase consumer regret. Originality/value This research is the first examination of an hedonic attitude to shopping and indulgent antecedents to self-gift purchasing, the concepts of self-gift motivations and their effect on post-purchase regret.
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Early determination of immune status is essential for the prevention and/or amelioration of disease following exposure to chickenpox. This is of particular significance for pregnant women because of the additional risks to the foetus or newborn.1 To determine the usefulness of a self-reported history of chickenpox in adult women in the Top End, we compared it with serological evidence of immunity.
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Background IL-20 is a pleiotrophic member of the IL-10 family and plays a role in skin biology and the development of haematopoietic cells. Recently, IL-20 has been demonstrated to have potential anti-angiogenic effects in non-small cell lung cancer (NSCLC) by down regulating COX-2. Methods The expression of IL-20 and its cognate receptors (IL-20RA/B and IL-22R1) was examined in a series of resected fresh frozen NSCLC tumours. Additionally, the expression and epigenetic regulation of this family was examined in normal bronchial epithelial and NSCLC cell lines. Furthermore, the effect of IL-20 on VEGF family members was examined. Results The expression of IL-20 and its receptors are frequently dysregulated in NSCLC. IL-20RB mRNA was significantly elevated in NSCLC tumours (p < 0.01). Protein levels of the receptors, IL-20RB and IL-22R1, were significantly increased (p < 0.01) in the tumours of NSCLC patients. IL-20 and its receptors were found to be epigenetically regulated through histone post-translational modifications and DNA CpG residue methylation. In addition, treatment with recombinant IL-20 resulted in decreased expression of the VEGF family members at the mRNA level. Conclusions This family of genes are dysregulated in NSCLC and are subject to epigenetic regulation. Whilst the anti-angiogenic properties of IL-20 require further clarification, targeting this family via epigenetic means may be a viable therapeutic option in lung cancer treatment. © 2011 Elsevier Ltd. All rights reserved.
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Background IL-23 is a member of the IL-6 super-family and plays key roles in cancer. Very little is currently known about the role of IL-23 in non-small cell lung cancer (NSCLC). Methods RT-PCR and chromatin immunopreciptiation (ChIP) were used to examine the levels, epigenetic regulation and effects of various drugs (DNA methyltransferase inhibitors, Histone Deacetylase inhibitors and Gemcitabine) on IL-23 expression in NSCLC cells and macrophages. The effects of recombinant IL-23 protein on cellular proliferation were examined by MTT assay. Statistical analysis consisted of Student's t-test or one way analysis of variance (ANOVA) where groups in the experiment were three or more. Results In a cohort of primary non-small cell lung cancer (NSCLC) tumours, IL-23A expression was significantly elevated in patient tumour samples (p<0.05). IL-23A expression is epigenetically regulated through histone post-translational modifications and DNA CpG methylation. Gemcitabine, a chemotherapy drug indicated for first-line treatment of NSCLC also induced IL-23A expression. Recombinant IL-23 significantly increased cellular proliferation in NSCLC cell lines. Conclusions These results may therefore have important implications for treating NSCLC patients with either epigenetic targeted therapies or Gemcitabine. © 2012 Elsevier Ireland Ltd.
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In recent years there has been a noticeable move by various public institutions, such as public service broadcasters and community media organisations, to capture and disseminate the voices and viewpoints of ‘ordinary people’ through inviting them to share stories about their lives. One of the foremost objectives of many such projects is to provide under-represented individuals and groups with an opportunity to express and represent themselves; as such, the capture and broadcast of ‘authentic voices’ is a central value. This paper discusses the notion of ‘authentic voice’, and questions the framing role of public media organisations in storytelling projects that aim to provide individuals with space for self-expression and self-representation. It considers the ways in which tensions arise on multiple levels when individuals are asked to express and represent themselves within projects and spaces that are managed by institutions. This paper begins by discussing the challenges and opportunities that arise within storytelling projects that are facilitated by public institutions and community media arts organisations, and that aim to amplify the voices of “ordinary people” (Thumim, 2009). It examines ways in which ‘voice’ is facilitated, curated, broadcast and distributed within such projects, particularly questioning the ways in which project facilitation and the curation of stories for public broadcast can both help and hinder the amplification of ‘authentic voice’. Furthermore, we seek to discuss how ‘authentic voice’ is defined, and what is involved in the process of amplification. The paper moves on to discuss a case study in order to demonstrate some of the tensions that are evident within a storytelling project that is managed by a public institution – Australia’s national broadcaster – and the ways these tensions impact upon the capture and broadcast of an ‘authentic voice’ for project participants. The Australian Broadcasting Corporation’s (ABC) ‘Heywire’ project is a storytelling competition and website that aims to ‘give voice’ to 16-22 year olds who live in rural, regional and remote parts of Australia. Looking at tensions that exist on organisational, political and philosophical levels within the Heywire project reveals a number of conflicts of interest and objectives between the institution and project participants. This leads us to question whether institutionally-managed storytelling projects can effectively support individuals to have an ‘authentic voice’, and whether struggles of aims and objectives diminish the personal benefits that people may derive from expressing and representing themselves within such projects.
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This paper discusses findings made during a study of energy use feedback in the home (eco-feedback), well after the novelty has worn off. Contributing towards four important knowledge gaps in the research, we explore eco-feedback over longer time scales, focusing on instances where the feedback was not of lasting benefit to users rather than when it was. Drawing from 23 semi-structured interviews with Australian householders, we found that an initially high level of engagement gave way over time to disinterest, neglect and in certain cases, technical malfunction. Additionally, preconceptions concerned with the “purpose” of the feedback were found to affect use. We propose expanding the scope of enquiry for eco-feedback in several ways, and describe how eco-feedback that better supports decision-making in the “maintenance phase”, i.e. once the initial novelty has worn off, may be key to longer term engagement.
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Mobile teledermatoscopy (MTD) for the early detection of skin cancer uses smartphones with dermatoscope attachments to magnify, capture, and transfer images remotely.1 Using the asymmetry–color variation (AC) rule, consumers achieve dermoscopy sensitivity of 92.9% to 94.0% and specificity of 62.0% to 64.2% for melanoma.2 This pilot randomized trial assessed lesions of concern selected by consumers at high risk of melanoma using MTD plus the AC rule (intervention, n = 10) or the AC rule alone (control, n = 12) during skin self-examination (SSE). Also measured were lesion location patterns, lesions overlooked by participants, provisional clinical diagnoses, likelihood of malignant tumor, and participant pressure to excise lesions.