1,583 research outputs found

    Testing a Unified Model of Task-specific Motivation: how teachers appraise three professional development activities

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    This article tests the tenability of a Unified Model of Task-specific Motivation (UMTM). The UMTM integrates task-specific components from several theories of motivation. Core of the model are four interacting but relatively independent types of valences. Affective and cognitive valences represent feelings while doing an activity and thoughts about the value of its consequences respectively; both affective and cognitive valences can be positive and negative, hence calling for approach and avoidance motivation respectively. The interaction between these four types of valences results in a valence appraisal that influences readiness for action. Task-specific antecedents, autonomy, feasibility, social relatedness and subjective norm, influence valences. 441 Primary school teachers provided judgments of all components of the model except social relatedness for three imaginary professional learning activities. The three activities were framed as a school board decided, a team decided and a personally decided learning activity. Structural equation modelling showed that for each activity a separate model was needed. How valences influenced readiness for action was specific to each activity. In the board and team decided activities, for instance, readiness for action appeared to be based predominantly on cognitive valences, while in the personally decided activity affective and cognitive valences showed a more balanced contribution. Regarding task-specific antecedents, however, the picture was less clear. Nevertheless, the UMTM proved to offer rich possibilities for the explanation of complex motivational phenomena and promises a significant reduction of the superabundance of theories that encumbers motivation research

    Is resilience a normative concept?

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    In this paper, we engage with the question of the normative content of the resilience concept. The issues are approached in two consecutive steps. First, we proceed from a narrow construal of the resilience concept – as the ability of a system to absorb a disturbance – and show that under an analysis of normative concepts as evaluative concepts resilience comes out as descriptive. In the second part of the paper, we argue that (1) for systems of interest (primarily social systems or system with a social component) we seem to have options with respect to how they are described and (2) that this matters for what is to be taken as a sign of resilience as opposed to a sign of the lack of resilience for such systems. We discuss the implications of this for how the concept should be applied in practice and suggest that users of the resilience concept face a choice between versions of the concept that are either ontologically or normatively charged

    Oxygen Poisoning in Laboratory Testing of Iron‐Based Ammonia Synthesis Catalysts and its Potential Sources

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    The influence of oxygen poisoning on a state-of-the-art multipromoted iron-based industrial catalyst for ammonia synthesis as well as the effectivity of different gas purification methods to prevent oxygen poisoning for experiments on laboratory scale were studied in detail. Additionally, the observed results were compared to a common oxygen poisoning test from literature, which on the one hand confirmed its usability in a wide range of conditions, but on the other hand also demonstrated the limitations of this test

    Perceptions of trends in Seychelles artisanal trap fisheries: comparing catch monitoring, underwater visual census and fishers' knowledge

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    Fisheries scientists and managers are increasingly engaging with fishers' knowledge (FK) to provide novel information and improve the legitimacy of fisheries governance. Disputes between the perceptions of fishers and scientists can generate conflicts for governance, but can also be a source of new perspectives or understandings. This paper compares artisanal trap fishers' reported current catch rates with landings data and underwater visual census (UVC). Fishers' reports of contemporary 'normal' catch per day tended to be higher than recent median landings records. However, fishers' reports of 'normal' catch per trap were not significantly different from the median CPUE calculated from landings data, and reports of 'good' and 'poor' catch rates were indicative of variability observed in landings data. FK, landings and UVC data all gave different perspectives of trends over a ten-year period. Fishers' perceptions indicated greater declines than statistical models fitted to landings data, while UVC evidence for trends varied between sites and according to the fish assemblage considered. Divergence in trend perceptions may have resulted from differences in the spatial, temporal or taxonomic focus of each dataset. Fishers may have experienced and understood behavioural changes and increased fishing power, which may have obscured declines from landings data. Various psychological factors affect memory and recall, and may have affected these memory-based estimates of trends, while different assumptions underlying the analysis of both interview data and conventional scientific data could also have led to qualitatively different trend perceptions. Differing perspectives from these three data sources illustrate both the potential for 'cognitive conflicts' between stakeholders who do not rely on the same data sources, as well as the importance of multiple information sources to understand dynamics of fisheries. Collaborative investigation of such divergence may facilitate learning and improve fisheries governance

    Ecological resilience, climate change, and the Great Barrier Reef

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    The vulnerability assessments in this volume frequently refer to the resilience of various ecosystem elements in the face of climate change. This chapter provides an introduction to the concept of ecological resilience, and its application as part of a management response to climate change threats. As defined in the glossary, resilience refers to the capacity of a system to absorb shocks, resist dramatic changes in condition, and maintain or recover key functions and processes, without undergoing "phase shifts" to a qualitatively different state (Figure 4.1)32, 72. For example, people who are physically and mentally fit and strong will have good prospect of recovery from disease, injury or trauma: they are resilient. In Figure 4.1, a ball placed at position 1 is dynamically stable: not only will it remain in position, but if pushed in any direction, it will return to its original position; thus the ball in this state is resilient, in that it can absorb shocks and return to a similar condition or state. In contrast, a ball placed at position 2 may be initially stable (it will remain in position if undisturbed) but not dynamically stable: if disturbed, it will move away. Thus the ball at position 2 is not resilient, and disturbances will result in a shift in state. If the ball at position 1 is disturbed to anywhere within the red circle, the ball will return to position 1; however, if disturbed further, the ball may not return, but may move to a new, alternate stable state (eg position 3). This system is resilient to disturbances that push it within the red boundary. However, if external factors decreased the depth of position 1, or lowered the saddle at point 2, then the system's resilience would be reduced. By analogy to coral reef ecosystems, position 1 might be a coral-dominated reef, and position 3 algal dominated. A disturbance such as killing coral that is overgrown by algae would move the reef toward an algal-dominated state; if the reef is resilient, this change would be temporary and natural processes would allow coral to re-establish and recover. If not, the algal dominance might be sufficient to preclude coral regrowth or recruitment, and the reef would change trajectory, moving toward algal dominance. Ecological resilience refers to the capacity of an ecosystem, habitat, population or taxon to withstand, recover from or adapt to impacts and stressors, such as climate change, and retain the same structure, processes and functions³². For example, coral reefs are naturally very dynamic, undergoing constant change and disturbances, but, under natural conditions, they have considerable capacity to recover or maintain key processes and functions in the face of such disturbances or pressures. Tropical storms may cause dramatic damage to coral populations, and hence to the physical habitat structure, with dead coral being overgrown by various forms of algae. This will result in a temporarily changed state, and changes in ecological functions. On a resilient reef, over a period of five to 20 years, the altered state is unstable: coral fragments will regrow, and new corals will settle, grow and gradually replace the algae, restoring the reef to coral dominance, and restoring ecological structure and processes. In contrast, however, if human impacts have undermined that resilience, algal growth may be exacerbated, coral regrowth and colonisation may be suppressed, and the altered state and processes may become stable, causing a long-term "phase shift", or change, to algal dominance

    Xenotransplantation of Human Neural Progenitor Cells to the Subretinal Space of Nonimmunosuppressed Pigs

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    To investigate the feasibility of transplanting human neural progenitor cells (hNPCs) to the retina of nonimmunosuppressed pigs, cultured hNPCs were injected into the subretinal space of 5 adult pigs after laser burns were applied to promote donor cell integration. Postoperatively, the retinal vessels appeared normal without signs of exudation, bleeding, or subretinal elevation. Eyes were harvested at 10–28 days. H&E consistently showed mild retinal vasculitis, depigmentation of the RPE, and marked mononuclear cell infiltrate in the choroid adjacent to the site of transplantation. Human-specific antibodies revealed donor cells in the subretinal space at 10–13 days and smaller numbers within the retina on days 12 and 13, with evidence suggesting a limited degree of morphological integration; however, no cells remained at 4 weeks. The strong mononuclear cell reaction and loss of donor cells indicate that modulation of host immunity is likely necessary for prolonged xenograft survival in this model

    Hyperadiponectinemia During Infliximab Induction Therapy in Pediatric Crohn Disease

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    Objectives: The inflammatory process in Crohn disease (CD) involves the visceral fat, characterized by adipocyte hyperplasia and altered adipose tissue and serum concentrations of tumor necrosis factor (TNF), leptin, adiponectin and resistin. We investigated the effect of anti-TNF therapy with infliximab (IFX) on serum adipokine levels in pediatric CD. Methods: Serum concentrations of resistin (ng/mL), leptin (ng/mL), and total adiponectin (mu g/mL) were assessed by enzyme-linked immunosorbent assays (ELISA) in 18 pediatric CD patients (mean age 15.0 +/- 1.5 years) before first, second, and fourth IFX infusion (weeks 0, 2, and 14) and compared with baseline values from sex- and BMI-matched healthy controls (HC, mean age 13.4 +/- 1.6 years). Results: At baseline, CD patients (mean age 15.0 +/- 1.5 years, 10 of 18 boys) compared with HC (13.4 +/- 1.6 years, 7 of 15 boys) had higher resistin levels (median 14.7 ng/mL, range 5.1-50.5 vs 7.3 ng/mL, 0.5-14.5);P = 0.0002). At weeks 2 and 14, resistin decreased to 6.9 ng/mL (2.9-16.8) (P < 0.0001) and 9.2 ng/mL (4.1-20.6;P = 0.0011), respectively. Leptin and adiponectin were comparable between patients and HC at baseline. Leptin increased in girls from 9.5 ng/mL (4.0-30.1) to 16.0 ng/mL (7.9-35.2;P = 0.0156) and 17.2 ng/mL (10.8-26.8;P = 0.1953) at weeks 0, 2, and 14 respectively;with a trend in boys from 2 (0.6-12.9) to 2.8 (1.7-8.6;P = 0.0840) and 3.3 (1.34.6;P = 0.1309). Adiponectin peaked initially from 7.8 mu g/mL (4.6-11.9) at week 0 to 9.2 mu g/mL (4.1-20.7;P = 0.0005) at week 2 and thereafter fell to 6.5 mu g/mL (3.0-12.7;P = 0.0182) at week 14. Conclusions: TNF blockade is associated with changes in circulating adipokines. The marked early increase of the potent anti-inflammatory adiponectin may contribute to the rapid response to IFX in CD

    Burn mass casualty incidents in Europe: A European response plan within the European Union Civil Protection Mechanism

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    Burns; Disaster planning; European UnionQuemaduras; Planificación de desastres; Unión EuropeaCremades; Planificació de desastres; Unió EuropeaBackground Burn care is centralized in highly specialized burn centers in Europe. These centers are of limited capacity and may be overwhelmed by a sudden surge in case of a burn mass casualty incident. Prior incidents in Europe and abroad have sustained high standards of care through well-orchestrated responses to share the burden of care in several burn centers. A burn mass casualty incident in Romania in 2015 sparked an initiative to strengthen the existing EU mechanisms. This paper aims to provide insight into developing a response plan for burn mass casualties within the EU Civil Protection Mechanism. Methods The European Burns Association drafted medical guidelines for burn mass casualty incidents based on a literature review and an in-depth analysis of the Romanian incident. An online questionnaire surveyed European burn centers and EU States for burn mass casualty preparedness. Results The Romanian burn mass casualty in 2015 highlighted the lack of a burn-specific mechanism, leading to the late onset of international transfers. In Europe, 71% of respondents had existing mass casualty response plans, though only 35% reported having a burn-specific plan. A burns response plan for burn mass casualties was developed and adopted as a Commission staff working document in preparation for further implementation. The plan builds on the existing Union Civil Protection Mechanism framework and the standards of the WHO Emergency Medical Teams initiative to provide 1) burn assessment teams for specialized in-hospital triage of patients, 2) specialized burn care across European burn centers, and 3) medevac capacities from participating states. Conclusion The European burn mass casualty response plan could enable the delivery of high-level burn care in the face of an overwhelming incident in an affected European country. Further steps for integration and implementation of the plan within the Union Civil Protection Mechanism framework are needed.This work was supported by funding from the European Commission, Directorate-General for European Civil Protection and Humanitarian Aid Operations (ECHO), Directorate B - Disaster Preparedness and Prevention, Unit B1 - Civil Protection Horizontal Issues by tender contract ECHO-B1-NP-2019-05 regarding a European response to mass burn casualty disasters

    Ammonia Decomposition in the Process Chain for a Renewable Hydrogen Supply

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    This review article deals with the challenge to identify catalyst materials from literature studies for the ammonia decomposition reaction with potential for application in large-scale industrial processes. On the one hand, the requirements on the catalyst are quite demanding. Of central importance are the conditions for the primary reaction that have to be met by the catalyst. Likewise, the catalytic performance, i.e., an ideally quantitative conversion, and a high lifetime are critical as well as the consideration of requirements on the product properties in terms of pressure or by-products for potential follow-up processes, in this case synthesis gas applications. On the other hand, the evaluation of the multitude of literature studies poses difficulties due to significant varieties in catalytic testing protocols
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