761 resultados para Self-efficacy in mathematics


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This study investigated self-esteem in children with developmental coordination disorder (DCD). Fifteen children between the ages of 8 and 12 years diagnosed with DCD were compared with a typically developing group comprising 30 children with average and good motor abilities, using measures of perceived competence, social support and self-esteem. The types of coping strategy generated in response to example vignettes were also compared. There was no significant difference between the groups in global self-esteem, but the children with DCD reported lower athletic and scholastic competence than their typically developing peers. No difference was found between the groups in level of perceived social support. The DCD group generated fewer coping strategies overall, but more passive and avoidant strategies than the typically developing children. The implications of the study are discussed with regard to future research directions, such as the investigation of the effects of motor skill intervention on self-esteem and the development of strategies to protect children's self-esteem.

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The large pine weevil, Hylobius abietis, is a serious pest of reforestation in northern Europe. However, weevils developing in stumps of felled trees can be killed by entomopathogenic nematodes applied to soil around the stumps and this method of control has been used at an operational level in the UK and Ireland. We investigated the factors affecting the efficacy of entomopathogenic nematodes in the control of the large pine weevil spanning 10 years of field experiments, by means of a meta-analysis of published studies and previously unpublished data. We investigated two species with different foraging strategies, the ‘ambusher’ Steinernema carpocapsae, the species most often used at an operational level, and the ‘cruiser’ Heterorhabditis downesi. Efficacy was measured both by percentage reduction in numbers of adults emerging relative to untreated controls and by percentage parasitism of developing weevils in the stump. Both measures were significantly higher with H. downesi compared to S. carpocapsae. General linear models were constructed for each nematode species separately, using substrate type (peat versus mineral soil) and tree species (pine versus spruce) as fixed factors, weevil abundance (from the mean of untreated stumps) as a covariate and percentage reduction or percentage parasitism as the response variable. For both nematode species, the most significant and parsimonious models showed that substrate type was consistently, but not always, the most significant variable, whether replicates were at a site or stump level, and that peaty soils significantly promote the efficacy of both species. Efficacy, in terms of percentage parasitism, was not density dependent.

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Higher levels of well-being are associated with longer life expectancies and better physical health. Previous studies suggest that processes involving the self and autobiographical memory are related to well-being, yet these relationships are poorly understood. The present study tested 32 older and 32 younger adults using scales measuring well-being and the affective valence of two types of autobiographical memory: episodic autobiographical memories and semantic self-images. Results showed that valence of semantic self-images, but not episodic autobiographical memories, was highly correlated with well-being,particularly in older adults. In contrast, well-being in older adults was unrelated to performance across a range of standardised memory tasks. These results highlight the role of semantic self-images in well-being, and have implications for the development of therapeutic interventions for well-being in aging.

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Adaptive governance is the use of novel approaches within policy to support experimentation and learning. Social learning reflects the engagement of interdependent stakeholders within this learning. Much attention has focused on these concepts as a solution for resilience in governing institutions in an uncertain climate; resilience representing the ability of a system to absorb shock and to retain its function and form through reorganisation. However, there are still many questions to how these concepts enable resilience, particularly in vulnerable, developing contexts. A case study from Uganda presents how these concepts promote resilient livelihood outcomes among rural subsistence farmers within a decentralised governing framework. This approach has the potential to highlight the dynamics and characteristics of a governance system which may manage change. The paper draws from the enabling characteristics of adaptive governance, including lower scale dynamics of bonding and bridging ties and strong leadership. Central to these processes were learning platforms promoting knowledge transfer leading to improved self-efficacy, innovation and livelihood skills. However even though aspects of adaptive governance were identified as contributing to resilience in livelihoods, some barriers were identified. Reflexivity and multi-stakeholder collaboration were evident in governing institutions; however, limited self-organisation and vertical communication demonstrated few opportunities for shifts in governance, which was severely challenged by inequity, politicisation and elite capture. The paper concludes by outlining implications for climate adaptation policy through promoting the importance of mainstreaming adaptation alongside existing policy trajectories; highlighting the significance of collaborative spaces for stakeholders and the tackling of inequality and corruption.

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People vary in the extent to which they prefer cooperative, competitive or individualistic achievement tasks. In the present research, we conducted two studies designed to investigate correlates and possible roots of these social interdependence orientations, namely approach and avoidance temperament, general self-efficacy, implicit theories of intelligence, and contingencies of self-worth based in others’ approval, competition, and academic competence. The results indicated that approach temperament, general self-efficacy, and incremental theory were positively, and entity theory was negatively related to cooperative preferences (|r| range from .11 to .41); approach temperament, general self-efficacy, competition contingencies, and academic competence contingencies were positively related to competitive preferences (|r| range from .16 to .46); and avoidance temperament, entity theory, competitive contingencies, and academic competence contingencies were positively related, and incremental theory was negatively related to individualistic preferences (|r| range from .09 to .15). The findings are discussed with regard to the meaning of each of the three social interdependence orientations, cultural differences among the observed relations, and implications for practicioners.

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The present longitudinal study examines the interaction of learner variables (gender, motivation, self-efficacy and first language literacy) and their influence on second language learning outcomes. The study follows English learners of French from Year 5 in primary school (aged 9-10) to the first year in secondary school (Year 7 aged 11-12). Language outcomes were measured by two oral production tasks; a sentence repetition task and a photo description task both of which were administered at three time points. Longitudinal data on learner attitudes and motivation were collected via questionnaires. Teacher assessment data for general first language literacy attainment were also provided. The results show a great deal of variation in learner attitudes and outcomes and that there is a complex relationship between first language literacy, self-efficacy, gender and attainment. For example, in general, girls held more positive attitudes to boys and were more successful. However, the inclusion of first language ability, which explained 30-40% of variation, shows that gender differences in attitudes and outcomes are likely mediated by first language literacy and prior learning experience.

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The UK government has sought to make changes to commercial property leasing practices. This has been the case since the recession of the 1990s. Industry self-regulation using an industry code of practice has been the vehicle for these changes. However, the code has had little direct success in changing practices. This is despite repeated threats of legislation as a constant backdrop to this initiative. The focus for this research is on the role of the industry bodies in the code initiative. They have been central to self-regulation in commercial leasing. Thus, the aim is to investigate the role of industry bodies in the process of institutional change. The context is industry self-regulation. The specific setting is commercial leasing. The main industry bodies in focus are the British Property Federation and Royal Institution of Chartered Surveyors. An existing model of institutional change forms the framework for the research. A chronological narrative is constructed from secondary data. This is analysed, identifying the actions of the industry bodies within the conceptual stages of the model. The analysis shows that the industry bodies had not acted as convincing agents of change for commercial leasing. In particular there was a lack of theorisation, a key stage in the process. The industry bodies did not develop a framework necessary to guide their members through the change process. These shortcomings of the industry bodies are likely to have contributed to the failure of the Code. However, the main conclusion is that, if industry self-regulation is led by government, then the state must work with industry bodies to harness their potential as champions and drivers of institutional change. This is particularly important in achieving change in institutionalised environments.

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The self-assembly in aqueous solution of three novel telechelic conjugates comprising a central hydrophilic polymer and short (trimeric or pentameric) tyrosine end-caps has been investigated. Two of the conjugates have a central poly(oxyethylene) (polyethylene oxide, PEO) central block with different molar masses. The other conjugate has a central poly(l-alanine) (PAla) sequence in a purely amino-acid based conjugate. All three conjugates self-assemble into β-sheet based fibrillar structures, although the fibrillar morphology revealed by cryogenic-TEM is distinct for the three polymers—in particular the Tyr5-PEO6k-Tyr5 forms a population of short straight fibrils in contrast to the more diffuse fibril aggregates observed for Tyr5-PEO2k-Tyr5 and Tyr3-PAla-Tyr3. Hydrogel formation was not observed for these samples (in contrast to prior work on related systems) up to quite high concentrations, showing that it is possible to prepare solutions of peptide–polymer-peptide conjugates with hydrophobic end-caps without conformational constraints associated with hydrogelation. The Tyr5-PEO6k-Tyr5 shows significant PEO crystallization upon drying in contrast to the Tyr5-PEO2k-Tyr5 conjugate. Our findings point to the remarkable ability of short hydrophobic peptide end groups to modulate the self-assembly properties of polymers in solution in model peptide-capped “associative polymers”. Retention of fluidity at high conjugate concentration may be valuable in potential future applications of these conjugates as bioresponsive or biocompatible materials, for example exploiting the enzyme-responsiveness of the tyrosine end-groups

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In this study we report detailed information on the internal structure of PNIPAM-b-PEG-b-PNIPAM nanoparticles formed from self-assembly in aqueous solutions upon increase in temperature. NMR spectroscopy, light scattering and small-angle neutron scattering (SANS) were used to monitor different stages of nanoparticle formation as a function of temperature, providing insight into the fundamental processes involved. The presence of PEG in a copolymer structure significantly affects the formation of nanoparticles, making their transition to occur over a broader temperature range. The crucial parameter that controls the transition is the ratio of PEG/PNIPAM. For pure PNIPAM, the transition is sharp; the higher the PEG/PNIPAM ratio results in a broader transition. This behavior is explained by different mechanisms of PNIPAM block incorporation during nanoparticle formation at different PEG/PNIPAM ratios. Contrast variation experiments using SANS show that the structure of nanoparticles above cloud point temperatures for PNIPAM-b-PEG-b-PNIPAM copolymers is drastically different from the structure of PNIPAM mesoglobules. In contrast with pure PNIPAM mesoglobules, where solid-like particles and chain network with a mesh size of 1-3 nm are present; nanoparticles formed from PNIPAM-b-PEG-b-PNIPAM copolymers have non-uniform structure with “frozen” areas interconnected by single chains in Gaussian conformation. SANS data with deuterated “invisible” PEG blocks imply that PEG is uniformly distributed inside of a nanoparticle. It is kinetically flexible PEG blocks which affect the nanoparticle formation by prevention of PNIPAM microphase separation.

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Exposure to intermittent episodes of social defeat stress can increase drug seeking and leads to intense drug taking in rats.This study investigated the consequences of repeated, intermittent social defeat stress on patterns of drug self-administration in rats with access to heroin, cocaine, or a heroin-cocaine combination (speedball).Male Long-Evans rats were either handled (controls) or subjected to 25-min social defeat stress episodes on days 1, 4, 7, and 10 during confrontations with an aggressive resident. Ten days following the last defeat, rats were assessed for locomotor cross-sensitization in response to heroin or cocaine. Animals were then prepared with intrajugular catheters for drug self-administration. Separate groups of controls and defeated rats were examined for self-administration of heroin (experiment 1), a heroin-cocaine combination (experiment 2), or cocaine (experiment 3). Drug self-administration patterns were evaluated using fixed or progressive ratio schedules of reinforcement during limited access sessions or a 24-h unlimited access binge.Rats with a history of intermittent social defeat stress showed sensitized locomotor behavior when challenged with heroin or cocaine relative to controls. During the 24-h binge session, defeated rats escalated cocaine-taking behavior (ca. 110 mg/kg vs. 66 mg/kg in controls), persisted in self-administering cocaine or the heroin-cocaine mixture for more hours, and showed a tendency for increased heroin-cocaine intake, but no effects on heroin taking.A history of social defeat stress seems to preferentially promote escalated intake of cocaine but not heroin, unless a heroin-cocaine combination is available.

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Background: The present study aimed to evaluate the efficacy of the hyaluronic acid (HA) binding assay in the selection of motile spermatozoa with normal morphology at high magnification (8400x).Methods: A total of 16592 prepared spermatozoa were selected and classified into two groups: Group I, spermatozoa which presented their head attached to an HA substance (HA-bound sperm), and Group II, those spermatozoa that did not attach to the HA substance (HA-unbound sperm). HA-bound and HA-unbound spermatozoa were evaluated according to the following sperm forms: 1-Normal morphology: normal nucleus (smooth, symmetric and oval configuration, length: 4.75+/-2.8 mu m and width: 3.28+/-0.20 mu m, no extrusion or invagination and no vacuoles occupied more than 4% of the nuclear area) as well as acrosome, post-acrosomal lamina, neck, tail, besides not presenting a cytoplasmic droplet or cytoplasm around the head; 2-Abnormalities of nuclear form (a-Large/small; b-Wide/narrow; c-Regional disorder); 3-Abnormalities of nuclear chromatin content (a-Vacuoles: occupy >4% to 50% of the nuclear area and b-Large vacuoles: occupy >50% of the nuclear area) using a high magnification (8400x) microscopy system.Results: No significant differences were obtained with respect to sperm morphological forms and the groups HA-bound and HA-unbound. 1-Normal morphology: HA-bound 2.7% and HA-unbound 2.5% (P = 0.56). 2-Abnormalities of nuclear form: a-Large/small: HA-bound 1.6% vs. HA-unbound 1.6% (P = 0.63); b-Wide/narrow: HA-bound 3.1% vs. HA-unbound 2.7% (P = 0.13); c-Regional disorders: HA-bound 4.7% vs. HA-unbound 4.4% (P = 0.34). 3. Abnormalities of nuclear chromatin content: a-Vacuoles >4% to 50%: HA-bound 72.2% vs. HA-unbound 72.5% (P = 0.74); b-Large vacuoles: HA-bound 15.7% vs. HA-unbound 16.3% (P = 0.36).Conclusions: The findings suggest that HA binding assay has limited efficacy in selecting motile spermatozoa with normal morphology at high magnification.

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Objective. We previously documented that abatacept was effective and safe in patients with juvenile idiopathic arthritis (JIA) who had not previously achieved a satisfactory clinical response with disease-modifying antirheumatic drugs or tumor necrosis factor blockade. Here, we report results from the long-term extension (LTE) phase of that study.Methods. This report describes the long-term, open-label extension phase of a double-blind, randomized, controlled withdrawal trial in 190 patients with JIA ages 6-17 years. Children were treated with 10 mg/kg abatacept administered intravenously every 4 weeks, with or without methotrexate. Efficacy results were based on data derived from the 153 patients who entered the open-label LTE phase and reflect >= 21 months (589 days) of treatment. Safety results include all available open-label data as of May 7, 2008.Results. of the 190 enrolled patients, 153 entered the LTE. By day 589, 90%, 88%, 75%, 57%, and 39% of patients treated with abatacept during the double-blind and LTE phases achieved responses according to the American College of Rheumatology (ACR) Pediatric 30 (Pedi 30), Pedi 50, Pedi 70, Pedi 90, and Pedi 100 criteria for improvement, respectively. Similar response rates were observed by day 589 among patients previously treated with placebo. Among patients who had not achieved an ACR Pedi 30 response at the end of the open-label lead-in phase and who proceeded directly into the LTE, 73%, 64%, 46%, 18%, and 5% achieved ACR Pedi 30, Pedi 50, Pedi 70, Pedi 90, and Pedi 100 responses, respectively, by day 589 of the LTE. No cases of tuberculosis and no malignancies were reported during the LTE. Pneumonia developed in 3 patients, and multiple sclerosis developed in 1 patient.Conclusion. Abatacept provided clinically significant and durable efficacy in patients with JIA, including those who did not initially achieve an ACR Pedi 30 response during the initial 4-month open-label lead-in phase.