370 resultados para long memory
Resumo:
Biological factors underlying individual variability in fearfulness and anxiety have important implications for stress-related psychiatric illness including PTSD and major depression. Using an advanced intercross line (AIL) derived from C57BL/6 and DBA/2J mouse strains and behavioral selection over 3 generations, we established two lines exhibiting High or Low fear behavior after fear conditioning. Across the selection generations, the two lines showed clear differences in training and tests for contextual and conditioned fear. Before fear conditioning training, there were no differences between lines in baseline freezing to a novel context. However, after fear conditioning High line mice demonstrated pronounced freezing in a new context suggestive of poor context discrimination. Fear generalization was not restricted to contextual fear. High fear mice froze to a novel acoustic stimulus while freezing in the Low line did not increase over baseline. Enhanced fear learning and generalization are consistent with transgenic and pharmacological disruption of the hypothalamic-pituitary-adrenal axis (HPA-axis) (Brinks, 2009, Thompson, 2004, Kaouane, 2012). To determine whether there were differences in HPA-axis regulation between the lines, morning urine samples were collected to measure basal corticosterone. Levels of secreted corticosterone in the circadian trough were analyzed by corticosterone ELISA. High fear mice were found to have higher basal corticosterone levels than low line animals. Examination of hormonal stress response components by qPCR revealed increased expression of CRH mRNA and decreased mRNA for MR and CRHR1 in hypothalamus of high fear mice. These alterations may contribute to both the behavioral phenotype and higher basal corticosterone in High fear mice. To determine basal brain activity in vivo in High and Low fear mice we used manganese-enhanced magnetic resonance imaging (MEMRI). Analysis revealed a pattern of basal brain activity made up of amygdala, cortical and hippocampal circuits that was elevated in the High line. Ongoing studies also seek to determine the relative balance of excitatory and inhibitory tone in the amygdala and hippocampus and the neuronal structure of its neurons. While these heterogeneous lines are selected on fear memory expression, HPA-axis alterations and differences in hippocampal activity segregate with the behavioral phenotypes. These differences are detectable in a basal state strongly suggesting these are biological traits underlying the behavioral phenotype (Johnson et al, 2011).
Resumo:
Business process models have traditionally been an effective way of examining business practices to identify areas for improvement. While common information gathering approaches are generally efficacious, they can be quite time consuming and have the risk of developing inaccuracies when information is forgotten or incorrectly interpreted by analysts. In this study, the potential of a role-playing approach for process elicitation and specification has been examined. This method allows stakeholders to enter a virtual world and role-play actions as they would in reality. As actions are completed, a model is automatically developed, removing the need for stakeholders to learn and understand a modelling grammar. Empirical data obtained in this study suggests that this approach may not only improve both the number of individual process task steps remembered and the correctness of task ordering, but also provide a reduction in the time required for stakeholders to model a process view.
Resumo:
Purpose - The purpose of this paper is to determine the impact stigma has on property values and how long the stigma remains after the Not in My Back Yard (NIMBY) structure has been removed. Design/methodology/approach - A quantitative analysis was undertaken, using a high voltage overhead transmission line (HVOTL) case study, to determine the effect on property values prior and post removal of the NIMBY structure. A repeat sales index in conjunction with the regression analysis determined the length of time, the stigma remained after removal of the NIMBY structure. Findings - The results show that while the NIMBY is in place the impact on value is confined to those properties in close proximity. This is in contradiction to the findings, where on removal of the NIMBY the property values of the whole neighbourhood improve with the stigma remaining for 3 to 4 years. Research Implications - The implication of this research is that property Valuers need to change the way they take into account the presence of NIMBYs when valuing property with more emphasis, being placed on the neighbourhood rather than just the properties in close proximity. While the HVOTL was in place, only properties in close proximity were negatively affected, but on removal of the HVOTL the whole neighbourhood increased in value. Originality/value - Results expand on current knowledge by demonstrating the length of time the market takes to adjust to the removal of a NIMBY structure.
Resumo:
Emotionally significant memories, especially those induced in conjunction with physical and mental trauma, are frequently retained for an individual’s lifetime. How these memories are organized and encoded within neural networks is a fundamental question. The lateral amygdala (LA) is a key nucleus for acquisition and maintenance of associative emotional memories. We used Pavlovian fear conditioning to study how ‘weaker’ and ‘stronger’ memories are encoded in neural networks of the LA. In Pavlovian fear conditioning a neutral stimulus, in this case a tone, is temporally paired with an aversive unconditioned stimulus (US), such as a foot shock. The previously neutral stimulus becomes a conditioned stimulus (CS) capable of eliciting defensive responses. We used time spent freezing when the CS is presented in a neutral context as a dependent variable measure of memory ‘strength’.
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Flexor digitorum longus transfer and medial displacement alcaneal osteotomy is a wellrecognised form of treatment or stage II posterior tibial tendon dysfunction. Although excellent short- and medium-term results have been reported, the long-term outcome is unknown. We reviewed the clinical outcome of 31 patients with a symptomatic flexible flatfoot deformity who underwent this procedure between 1994 and 1996. There were 21 women and ten men with a mean age of 54.3 years (42 to 70). The mean follow-up was 15.2 years (11.4 to 16.5). All scores improved significantly (p < 0.001). The mean American Orthopedic Foot and Ankle Society (AOFAS) score improved from 48.4 pre-operatively to 90.3 (54 to 100) at the final follow-up. The mean pain component improved from 12.3 to 35.2 (20 to 40). The mean function score improved from 35.2 to 45.6 (30 to 50). The mean visual analogue score for pain improved from 7.3 to 1.3 (0 to 6). The mean Short Form-36 physical component score was 40.6 (SD 8.9), and this showed a significant correlation with the mean AOFAS score (r = 0.68, p = 0.005). A total of 27 patients (87%) were pain free and functioning well at the final follow-up. We believe that flexor digitorum longus transfer and calcaneal osteotomy provides long-term pain relief and satisfactory function in the treatment of stage II posterior tibial tendon dysfunction.
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Long-term systematic population monitoring data sets are rare but are essential in identifying changes in species abundance. In contrast, community groups and natural history organizations have collected many species lists. These represent a large, untapped source of information on changes in abundance but are generally considered of little value. The major problem with using species lists to detect population changes is that the amount of effort used to obtain the list is often uncontrolled and usually unknown. It has been suggested that using the number of species on the list, the "list length," can be a measure of effort. This paper significantly extends the utility of Franklin's approach using Bayesian logistic regression. We demonstrate the value of List Length Analysis to model changes in species prevalence (i.e., the proportion of lists on which the species occurs) using bird lists collected by a local bird club over 40 years around Brisbane, southeast Queensland, Australia. We estimate the magnitude and certainty of change for 269 bird species and calculate the probabilities that there have been declines and increases of given magnitudes. List Length Analysis confirmed suspected species declines and increases. This method is an important complement to systematically designed intensive monitoring schemes and provides a means of utilizing data that may otherwise be deemed useless. The results of List Length Analysis can be used for targeting species of conservation concern for listing purposes or for more intensive monitoring. While Bayesian methods are not essential for List Length Analysis, they can offer more flexibility in interrogating the data and are able to provide a range of parameters that are easy to interpret and can facilitate conservation listing and prioritization. © 2010 by the Ecological Society of America.
Resumo:
Changing environments pose a serious problem to current robotic systems aiming at long term operation under varying seasons or local weather conditions. This paper is built on our previous work where we propose to learn to predict the changes in an environment. Our key insight is that the occurring scene changes are in part systematic, repeatable and therefore predictable. The goal of our work is to support existing approaches to place recognition by learning how the visual appearance of an environment changes over time and by using this learned knowledge to predict its appearance under different environmental conditions. We describe the general idea of appearance change prediction (ACP) and investigate properties of our novel implementation based on vocabularies of superpixels (SP-ACP). Our previous work showed that the proposed approach significantly improves the performance of SeqSLAM and BRIEF-Gist for place recognition on a subset of the Nordland dataset under extremely different environmental conditions in summer and winter. This paper deepens the understanding of the proposed SP-ACP system and evaluates the influence of its parameters. We present the results of a large-scale experiment on the complete 10 h Nordland dataset and appearance change predictions between different combinations of seasons.
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Javanese Performances on an Indonesian Stage: Contesting Culture, Embracing Change, is Barbara Hatley’s first book about the performing arts in Indonesia, a topic that piqued her interest while undergoing a masters program at Yale University in the late 1960s. In this sense, it is a landmark study, for Hatley has since become very well known in Indonesianist circles, especially among those with an interest in matters of culture, popular and elite. Until recently, her writings on Indonesian performing arts have only been available in the form of journal articles and book chapters...
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A travel story about a return journey to the Greek island of Corfu. "THEY say it doesn’t pay to go back. The more a place meant to you in the past, the more likely it is that you’ll be disappointed when you return. Recently I tested the theory, and endangered my memories of the Greek island of Corfu with a second visit..."--publisher website
Resumo:
In this paper, Bree Hadley discusses The Ex/centric Fixations Project, a practice-led research project which explores the inadequacy of language as a technology for expressing human experiences of difference, discrimination or marginalisation within mainstream cultures. The project asks questions about the way experience, memory and the public discourses available to express them are bound together, about the silences, failures and falsehoods embedded in any effort to convey human experience via public discourses, and about how these failures might form the basis of a performative writing method. It has, to date, focused on developing a method that expresses experience through improvised, intertextual and discontinous collages of language drawn from a variety of public discourses. Aesthetically, this method works with what Hans Theis Lehmann (Postdramatic Theatre p. 17) calls a “textual variant” of the postdramatic “in which language appears not as the speech of characters – if there are still definable characters at all – but as an autonomous theatricality” (Ibid. 18). It is defined by what Lehmann, following Julia Kristeva, calls a “polylogue”, which presents experience as a conflicted, discontinuous and circular phenomenon, akin to a musical fugue, to break away from “an order centred on one logos” (Ibid. 32). The texts function simultaneously as a series of parts, and as wholes, interwoven voices seeming almost to connect, almost to respond to each other, and almost to tell – or challenging each other’s telling – of a story. In this paper, Hadley offers a performative demonstration, together with descriptions of the way spectators respond, including the way their playful, polyvocal texture impacts on engagement, and the way the presence or non-presence of performing bodies to which the experiences depicted can be attached impacts on engagement. She suggests that the improvised, intertextual and experimental enactments of self embodied in the texts encourage spectators to engage at an emotional level, and make-meaning based primarily on memories they recall in the moment, and thus has the potential to counter the risk that people may read depictions of experiences radically different from their own in reductive, essentialised ways.
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In the structural health monitoring (SHM) field, long-term continuous vibration-based monitoring is becoming increasingly popular as this could keep track of the health status of structures during their service lives. However, implementing such a system is not always feasible due to on-going conflicts between budget constraints and the need of sophisticated systems to monitor real-world structures under their demanding in-service conditions. To address this problem, this paper presents a comprehensive development of a cost-effective and flexible vibration DAQ system for long-term continuous SHM of a newly constructed institutional complex with a special focus on the main building. First, selections of sensor type and sensor positions are scrutinized to overcome adversities such as low-frequency and low-level vibration measurements. In order to economically tackle the sparse measurement problem, a cost-optimized Ethernet-based peripheral DAQ model is first adopted to form the system skeleton. A combination of a high-resolution timing coordination method based on the TCP/IP command communication medium and a periodic system resynchronization strategy is then proposed to synchronize data from multiple distributed DAQ units. The results of both experimental evaluations and experimental–numerical verifications show that the proposed DAQ system in general and the data synchronization solution in particular work well and they can provide a promising cost-effective and flexible alternative for use in real-world SHM projects. Finally, the paper demonstrates simple but effective ways to make use of the developed monitoring system for long-term continuous structural health evaluation as well as to use the instrumented building herein as a multi-purpose benchmark structure for studying not only practical SHM problems but also synchronization related issues.
Resumo:
Background Dementia is a chronic illness without cure or effective treatment, which results in declining mental and physical function and assistance from others to manage activities of daily living. Many people with dementia live in long term care facilities, yet research into their quality of life (QoL) was rare until the last decade. Previous studies failed to incorporate important variables related to the facility and care provision or to look closely at the daily lives of residents. This paper presents a protocol for a comprehensive, multi-perspective assessment of QoL of residents with dementia living in long term care in Australia. A secondary aim is investigating the effectiveness of self-report instruments for measuring QoL. Methods The study utilizes a descriptive, mixed methods design to examine how facility, care staff, and resident factors impact QoL. Over 500 residents with dementia from a stratified, random sample of 53 facilities are being recruited. A sub-sample of 12 residents is also taking part in qualitative interviews and observations. Conclusions This national study will provide a broad understanding of factors underlying QoL for residents with dementia in long term care. The present study uses a similar methodology to the US-based Collaborative Studies of Long Term Care (CS-LTC) Dementia Care Study, applying it to the Australian setting.