945 resultados para experiential avoidance


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Impulse control, an executive process that restrains inappropriate actions, is impaired in numerous psychiatric conditions. This thesis reports three experiments that utilized a novel animal model of impulse control, the response inhibition (RI) task, to examine the substrates that underlie learning this task. In the first experiment, rats were trained to withhold responding on the RI task, and then euthanized for electrophysiological testing. Training in the RI task increased the AMPA/NMDA ratio at the synapses of pyramidal neurons in the prelimbic, but not infralimbic, region of the medial prefrontal cortex. This enhancement paralleled performance as subjects underwent acquisition and extinction of the inhibitory response. AMPA/NMDA was elevated only in neurons that project to the ventral striatum. Thus, this experiment identified a synaptic correlate of impulse control. In the second experiment, a separate group of rats were trained in the RI task prior to electrophysiological testing. Training in the RI task produced a decrease in membrane excitability in prelimbic, but not infralimbic, neurons as measured by maximal spiking evoked in response to increasing current injection. Importantly, this decrease was strongly correlated with successful inhibition in the task. Fortuitously, subjects trained in an operant control condition showed elevated infralimbic, but not prelimbic, excitability, which was produced by learning an anticipatory signal that predicted imminent reward availability. These experiments revealed two cellular correlates of performance, corresponding to learning two different associations under distinct task conditions. In the final experiment, rats were trained on the RI task under three conditions: Short (4-s), long (60-s), or unpredictable (1-s to 60-s) premature phases. These conditions produced distinct errors on the RI task. Interestingly, amphetamine increased premature responding in the short and long conditions, but decreased premature responding in the unpredictable condition. This dissociation may arise from interactions between amphetamine and underlying cognitive processes, such as attention, timing, and conditioned avoidance. In summary, this thesis showed that learning to inhibit a response produces distinct synaptic, cellular, and pharmacological changes. It is hoped that these advances will provide a starting point for future therapeutic interventions of disorders of impulse control.

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The aim of the paper is to explore teachers’ methods of delivering an ethos of tolerance, respect
and mutual understanding in one integrated secondary school in Northern Ireland. Drawing on
interviews with teachers in the school, it is argued that most teachers make ‘critical choices’
which both reflect and reinforce a ‘culture of avoidance’, whereby politically or religiously contentious
issues are avoided rather than explored. Although teachers are well-intentioned in making
these choices, it is shown that they have the potential to create the conditions that maintain or even
harden psychological boundaries between Catholics and Protestants rather than dilute them.

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Dense deployment of wireless local area network (WLAN) access points (APs) is an important part of the next generation Wi-Fi and standardization (802.11ax) efforts are underway. Increasing demand for WLAN connectivity motivates such dense deployments, especially in geographical areas with large numbers of users, such as stadiums, large enterprises, multi-tenant buildings, and urban cities. Although densification of WLAN APs guarantees coverage, it is susceptible to increased interference and uncoordinated association of stations (STAs) to APs, which degrade network throughput. Therefore, to improve network throughput, algorithms are proposed in this thesis to optimally coordinate AP associations in the presence of interference. In essence, coordination of APs in dense WLANs (DWLANs) is achieved through coordination of STAs' associations with APs. While existing approaches suggest tuning of APs' beacon powers or using transmit power control (TPC) for association control, here, the signal-to-interference-plus-noise ratio (SINRs) of STAs and the clear channel assessment (CCA) threshold of the 802.11 MAC protocol are employed. The proposed algorithms in this thesis enhance throughput and minimize coverage holes inherent in cell breathing and TPC techniques by not altering the transmit powers of APs, which determine cell coverage. Besides uncoordinated AP associations, unnecessary frequent transmission deferment is envisaged as another problem in DWLANs due to the clear channel assessment aspect of the carrier sensing multiple access collision avoidance (CSMA/CA) scheme in 802.11 standards and the short spatial reuse distance between co-channel APs. To address this problem in addition to AP association coordination, an algorithm is proposed for CCA threshold adjustment in each AP cell, such that CCA threshold used in one cell mitigates transmission deferment in neighboring cells. Performance evaluation reveals that the proposed association optimization algorithms achieve significant gain in throughput when compared with the default strongest signal first (SSF) association scheme in the current 802.11 standard. Also, further gain in throughput is observed when the CCA threshold adjustment is combined with the optimized association. Results show that when STA-AP association is optimized and CCA threshold is adjusted in each cell, throughput improves. Finally, transmission delay and the number of packet re-transmissions due to collision and contention significantly decrease.

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En este artículo presentamos los resultados y el análisis de uno de los objetivos del proyecto I+D+i aprobado por el Ministerio de Economía y Competitividad de España titulado Mediaciones audiovisuales en las relaciones entre escuela y familias inmigrantes. Concretamente, el dirigido a conocer las funciones que tienen las imágenes fotográficas en las relaciones de un grupo de padres inmigrantes en el colegio al que asisten sus hijos e hijas. Los datos presentados corresponden a las narraciones biográfico-culturales y visuales iniciadas en las aulas por estas familias junto a la tutora del grupo, y continuadas en sus contextos personal y social. Concluimos que las fotografías en los relatos han tenido las funciones de: fuente de información, soporte de análisis, reflexión y debate y, finalmente, medio para comunicar el conocimiento experiencial generado. Dentro de esta última, se han utilizado tres procedimientos que hemos denominado: denotativo autorreferencial, connotativo texto-visual y secuencial.

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This article presents an educational experiment carried out in the Primary School Teaching Degree at the University of Barcelona. Specifically, the article analyses the application of the “Work Corners” approach in a core subject. In a three-year action research process, trainers put into practice an innovation which enabled them to boost cooperative work and reflexive learning among trainees. Firstly, the theoretical model underpinning the project and guiding many of the actions carried out by the training team is presented. After providing detailed information on the practical development of the experiment, the data-gathering process and its results are shown. Various information-gathering strategies were used in assessing the project, such as a questionnaire, participant observation, and teachers’ diaries. The results demonstrate, amongst other things, that “work corners” offer viable and appropriate educational conditions for the articulation of theoretical and practical knowledge, for building professional knowledge, and therefore, the beginnings of a reflexive teaching practice.

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In this article, we address the importance and relevance that social networks exhibit in their use as an educational resource.  This relevance relies in the possibility of implementing new learning resources or increasing the level of the participant's connectivity, as well as developing learning communities.  Also, the risk entailed from their use is discussed, especially for the students that have a low technological education or those having excessive confidence on the media.  It is important to highlight that the educational use of social networks is not a simple extension or translation of the student's habitual, recreational use, but that it implies an important change in the roles given to teachers as well as learners; from accommodative learning environments that only encourage memorization to other environments that demand an active, reflective, collaborative and proactive attitude, that require the development/acquisition of technological as well as social abilities, aptitudes and values.  It is also important to highlight that a correct implementation and adequate use will not only foment formal learning, but also informal and non-formal learning.

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Purpose: To investigate the association of cardiovascular risk factors and inflammatory markers with neovascular age-related macular degeneration (AMD). Design: Cross-sectional case-control study. Participants: Of the 410 of the =65-year-old community sample invited to attend, 205 participated (50% response rate). Of the 215 clinic attendees who were invited to participate, 212 agreed to take part (98% response rate). A diagnosis of neovascular AMD in at least one eye was made in 193 clinic attendees and 2 of the community sample. Methods: Clinic and community participants underwent a detailed ophthalmic examination with fundus imaging, were interviewed for assessment of putative risk factors, and provided a blood sample. Analysis included levels of serum lipids, intercellular adhesion molecule 1 (ICAM), vascular cellular adhesion molecule (VCAM), and C-reactive protein (CRP). All participants were classified by fundus image grading on the basis of the eye with more severe AMD features. Main Outcome Measure: Neovascular AMD. Results: There were 195 participants with choroidal neovascularization in at least one eye, 97 nonneovascular AMD participants, and 115 controls (no drusen or pigmentary irregularities in either eye). In confounder-adjusted logistic regression, a history of cardiovascular disease was strongly associated with neovascular AMD (odds ratio [OR], 7.53; 95% confidence interval [CI], 2.78-20.41). Cigarette smoking (OR, 3.71; 95% CI, 1.25-11.06), being in the highest quartile of body mass index (OR, 3.82; 95% CI, 1.22-12.01), stage 2 hypertension (OR, 3.21; 95% CI, 1.14-8.98), and being in the highest quartile of serum cholesterol (OR, 4.66; 95% CI, 1.35-16.13) were positively associated with neovascular AMD. There was no association between AMD status and serum CRP, ICAM, or VCAM. Conclusions: Our results suggest that cardiovascular disease plays an etiological role in the development of choroidal neovascularization in a proportion of older adults and highlight the importance of control of blood pressure and cholesterol, avoidance of smoking, and maintenance of a normal body weight. © 2008 American Academy of Ophthalmology.

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Sustainable development is now widely held as a transcendental ideal of town and country planning, yet the way in which it is taught in planning schools remains problematic. This arises from a range of factors, including the all-persuasive nature of sustainability and the lack of solid examples of success through implementation. The issue of how best to promote learning for sustainable development in planning has arguably intensified in the last two years in the case of the Royal Town Planning Institute- sponsored ‘fast track’ one-year Masters, which has reduced the opportunities for students to engage in wider (and perhaps even deeper) concepts, including that of sustainable development. This paper explores this through discussion of a specific project developed at Queen’s University Belfast, facilitated by a grant from the UK Higher Education Academy. Working with a local community, this entailed a group of students working on their Masters thesis collectively addressing issues of sustainable regeneration in a small Irish market town. The design of the project draws heavily on the concepts of enquiry based learning, experiential learning and action competence, whichare seen as being central to improving education for sustainable development (ESD). The paper explores the benefits of such an approach and discusses the ways in which this experience can help enhance student’s experience of ESD.

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A conventional local model (LM) network consists of a set of affine local models blended together using appropriate weighting functions. Such networks have poor interpretability since the dynamics of the blended network are only weakly related to the underlying local models. In contrast, velocity-based LM networks employ strictly linear local models to provide a transparent framework for nonlinear modelling in which the global dynamics are a simple linear combination of the local model dynamics. A novel approach for constructing continuous-time velocity-based networks from plant data is presented. Key issues including continuous-time parameter estimation, correct realisation of the velocity-based local models and avoidance of the input derivative are all addressed. Application results are reported for the highly nonlinear simulated continuous stirred tank reactor process.

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Adults are proficient at reaching to grasp objects of interest in a cluttered workspace. The issue of concern, obstacle avoidance, was studied in 3 groups of young children aged 11-12, 9-10, and 7-8 years (n = 6 in each) and in 6 adults aged 18-24 years. Adults slowed their movements and decreased their maximum grip aperture when an obstacle was positioned close to a target object (the effect declined as the distance between target and obstacle increased). The children showed the same pattern, but the magnitude of the effect was quite different. In contrast to the adults, the obstacle continued to have a large effect when it was some distance from the target (and provided no physical obstruction to movement).

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This paper examines the epistemological bases for the inclusion of stakeholders in policy research. While it concedes that the input of stakeholders provides essential expert and experiential knowledge for the understanding of complex policies and programmes, it contends that the approach which assumes that all interpretations of policy including those of stakeholders should be afforded equal validity, which we term relativist perspectivism, undermines the possibility of robust research by allowing power to replace methodological rigour as the primary research dynamic. It is noted that this problem tends to be more acute when the research is qualitative. A study into the gendered effects of Common Agricultural Policy reforms is used as an illustrative example of how research can be compromised by relativist perspectivism. It is argued that realist research methodologies uniquely provide the capacity to maintain epistemological robustness, while also being able to take due account of the perspectives of stakeholders.

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This paper describes the use of a peer research methodology to explore disaffected young people’s views on alternative education. This model was adopted in order to try to ensure an equilibrium of power between interviewer and interviewee, allow marginalised young people’s voices to be heard and help generate social action. The approach is examined from the perspective of both the peer research and adult research teams. An experiential and honest account is given including the problems and successes, as well as the lessons learned. The paper concludes by considering the value of the model, whether it helps to reach those alienated from education and any evidence that it provides an opportunity for them to have a stake in their future.

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Increased productivity and improved working environment have had high priority in the development of concrete construction over the last decade. Development of a material not needing vibration for compaction—i.e. selfcompacting concrete (SCC)—has successfully met the challenge and is now increasingly being used in routine practice. The key to the improvement of fresh concrete performance has been nanoscale tailoring of molecules for surface active admixtures, as well as improved understanding of particle packing and of the role of mineral surfaces in cementitious matrixes. Fundamental studies of rheological behaviour of cementitious particle suspensions were soon expanded to extensive innovation programmes incorporating applied research, site experiments, instrumented full scale applications supporting technology, standards and guides, information efforts as well as training programmes. The major impact of the introduction of SCC is connected to the production process. The choice and handling of constituents are modified as well as mix design, batching, mixing and transporting. The productivity is drastically improved through elimination of vibration compaction and process reorganisation. The working environment is significantly enhanced through avoidance of vibration induced damages, reduced noise and improved safety. Additionally, the technology is improving performance in terms of hardened material properties like surface quality, strength and durability.

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The Labour Government in the UK has announced, as part of its launch of The Children's Plan, that it 'wants to make this country the best place in the world for children and young people to grow up' in. This latest Plan is further evidence of the surge of interest that there has been in children (and, in particular, early childhood) over the last ten years in the UK and indeed elsewhere. Many of the recent policy and practice initiatives have implications for social workers working with young children. Yet, social work as a profession, in comparison with education, has remained relatively silent on these initiatives and it is hard to find any critical analysis of these developments in terms of either their underlying discourses or their implications for social workers. This article sets out to address these gaps by providing a critical analysis of: what types of knowledge regarding the early years have gained political currency; why and how this is the case; and what the implications are for the role and practices of social workers. The article proposes that discourses of 'need' and 'provision' mask more powerful discourses of economics, social control and risk avoidance, and it concludes by advocating more critically reflexive social work practice with young children and their families.

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Background:
The relationship between PTSD and complex PTSD remains unclear. As well as further addressing this issue, the current study aimed to assess the degree to which DESNOS (complex PTSD) was related to interpersonal trauma and had relational consequences.

Methods:
Eighty one treatment-receiving participants with a history of exposure to the ‘Troubles’ in Northern Ireland, were assessed on various forms of interpersonal trauma, including exposure to the Troubles, and measures of interpersonal and community connectedness.

Results:
DESNOS symptom severity was related to childhood sexual abuse and perceived psychological impact of Troubles-related exposure. A lifetime diagnosis of DESNOS was related to childhood Troubles-related experiences, while a current diagnosis of DESNOS was associated with childhood emotional neglect. PTSD avoidance predicted current DESNOS diagnosis and severity. Feeling emotionally disconnected from family and friends (i.e., interpersonal disconnectedness) was related to all three indices of DESNOS (i.e., lifetime diagnosis, current diagnosis and current symptom severity).

Limitations:
Sample characteristics (i.e., treatment-receiving) and size may limit the generalizability of findings.

Conclusions:
Complex PTSD is associated with PTSD but when present should be considered a superordinate diagnosis.