534 research outputs found
A Survey on Event-based News Narrative Extraction
Narratives are fundamental to our understanding of the world, providing us
with a natural structure for knowledge representation over time. Computational
narrative extraction is a subfield of artificial intelligence that makes heavy
use of information retrieval and natural language processing techniques.
Despite the importance of computational narrative extraction, relatively little
scholarly work exists on synthesizing previous research and strategizing future
research in the area. In particular, this article focuses on extracting news
narratives from an event-centric perspective. Extracting narratives from news
data has multiple applications in understanding the evolving information
landscape. This survey presents an extensive study of research in the area of
event-based news narrative extraction. In particular, we screened over 900
articles that yielded 54 relevant articles. These articles are synthesized and
organized by representation model, extraction criteria, and evaluation
approaches. Based on the reviewed studies, we identify recent trends, open
challenges, and potential research lines.Comment: 37 pages, 3 figures, to be published in the journal ACM CSU
Temporal and Spatial Occlusion of Advanced Visual Information Constrains Movement (Re) organization in One-Handed Catching Behaviors
Dynamic interceptive actions are performed under severe spatial and temporal constraints. Here, behavioral processes underpinning anticipation in one-handed catching were examined using novel technology to implement a spatial and temporal occlusion design. Video footage of an actor throwing a ball was manipulated to create four temporal and five spatial occlusion conditions. Data from twelve participants’ hand kinematics and gaze behaviors were recorded while attempting to catch a projected ball synchronized with the video footage. Catching performance decreased with earlier occlusion of the footage. Movement onset of the catching hand and initiation of visual ball tracking emerged earlier when footage of the thrower was occluded at a later time point in the throwing action. Spatial occlusion did not affect catching success, although movement onset emerged later when increased visual information of the actor was occluded. Later movement onset was countered by greater maximum velocity of the catching hand. Final stages of action (e.g., grasping action of the hand) remained unchanged across both spatial and temporal conditions suggesting that later phases of the action were organized using ball flight information. Findings highlighted the importance of maintaining information-movement coupling during performance of interceptive actions, since movement behaviors were continuously (re)organized using kinematic information from a thrower's actions and ball flight information.
Keywords: Perception-action coupling; Informational constraints; Interceptive timing; Gaze; Adaptive behaviors; Anticipation
Hot hands, cold feet? Investigating effects of interacting constraints on place kicking performance at the 2015 Rugby Union World Cup
Place kicks in Rugby Union present valuable opportunities to score points outside the spatiotemporal dynamics of open play but are executed under varying performance constraints. We analysed effects of specific task constraints and relevant contextual factors on place kick performance in the 2015 Rugby Union World Cup. Data were collected from television broadcasts for each place kick. In addition to kick outcomes, contextual factors, including time of the kick in the match, score margin at the time of the kick, and outcome of the kicker’s previous kick, were recorded. Effects of spatial task constraints were analysed for each kick, using distance (m) and angle (°) of the kick to the goalposts. A binomial logistic regression model revealed that distance from, and angle to, the goalposts were significant predictors of place kick outcome. Furthermore, the success percentage of kickers who missed their previous kick was 7% lower than those who scored their previous kick. Place kick success percentage in the 10 minutes before half-time was 8% lower than the mean tournament success percentage, which was 75% (95% CI 71% to 78%). The highest kick success percentage was recorded when scores were level (83%; 95% CI 72% to 91%). Our data highlighted how subtle changes in task constraints and contextual factors can influence performance outcomes in elite performers in international competition. Fluctuations in place kick success suggested that individual constraints, such as thoughts, emotions, and fatigue, induced during competition, could interact with perceptions to influence emergent performance behaviours
Experiential knowledge of elite Rugby Union players on key performance constraints in place kicking
There has been a growing tendency in sport science research to examine the relationship between empirical knowledge developed in scientific experiments and theoretical frameworks and the experiential knowledge of elite performers and practitioners (Jones, Bezodis, & Thompson, 2009; Greenwood, Davids, & Renshaw, 2014; Phillips, Davids, Renshaw, & Portus, 2014). In this study, we investigated the experiential knowledge of elite Rugby Union place kickers to access their understanding of how to satisfy interacting constraints of competitive performance and practice environments. Place kicks in Rugby Union offer opportunities to score points outside the spatiotemporal dynamics of open play, but are typically performed under varying task and contextual constraints within a performance environment. Success percentage of place kicks can fluctuate under specific task and contextual constraints, as shown in a recent analysis of the 2015 Rugby World Cup (Pocock, Bezodis, Davids, & North, under review). For example, success percentage can drop sharply at critical thresholds of distance and angle to the goalposts and can vary depending on time elapsed, score margin and previous kick success. Interestingly, place kicks in the 10 minutes before half time were 8% less successful than the tournament average, and place kickers who had missed their previous kick were 7% less successful than place kickers who had scored their previous kick. It has therefore been speculated that emotions induced during competition can interact with perceptions and action to influence the emergent behaviours of place kickers. To develop greater understanding of how fluctuations in performance data may emerge, we interviewed professional Rugby Union place kickers and sought to explore their experiences of satisfying key interacting constraints on performance. Specifically, we aimed to investigate the key constraints that place kickers perceive to influence their emotions and perceptions of task difficulty. A secondary aim of the interviews was to identify specific details of how place kicking situations are currently practised, and why they are structured in this way. We present here the experiential knowledge of place kickers which includes their perceptions of the key constraints in performance environments and how they currently prepare for place kicks. Our findings highlighted how performance constraints can influence emotions, cognitions and perceptions during place kicking performance and the data indicated how the key constraints identified in this study, combined with the findings of previous quantitative analyses, could be represented in training environments. Initial interviews revealed that place kicking is predominantly practised individually and in isolation from game-based scenarios in training, without any form of pressure or expectation. Examples of pressure that place kickers identified in interviews included expectations of team-mates, performing in front of large crowds and closely-matched scores. This presentation will conclude by discussing how an integration of empirical and experiential knowledge can enrich understanding of sport performance and provide recommendations for coaches when designing practice environments which simulate relevant performance constraints to enhance the adaptive skills of elite and developing athletes in sport
Embedding and sustaining change in technology-enhanced education : lessons learned from a cross-institutional transformation project
Acknowledgements The authors would like to acknowledge the work of Liz Foulis of Lauder (now Carnegie) College and Julie McCran from Edinburgh’s Telford College for the contribution they made as members of the core project team. We are also indebted to Heather Sanderson, the project manager, Dr Peter Easy who chaired the project steering group, and to other members of the project management team (Isabel Craig, Pascale Gay, Fred Percival and our administrator Anne Wardrope). Roger Rist and Laurence Patterson comprised the project’s evaluation team, while David Griggs produced the video case studies. TESEP was funded through a two-year grant from the Scottish Funding Council to Edinburgh Napier University in partnership with Edinburgh’s Telford College and Lauder College, Dunfermline.Peer reviewedPublisher PD
Patterns of the business education curricula of the member institutions of business teacher-training institutions
The growth of American colleges and universities has been marked by a lack of unity. Each college and university has manifested its individualism in organization, administration and curricula. Concerning the growth of the American teachers college, or the normal school, as it was first called, Pangburn makes the following comment: The American Normal school grew up in response to a gradually increasing recognition on the part of the public that some means of preparing teachers was needed in order to insure the fulfillment of the purpose for which the schools were created. As an outgrowth of public education, the normal school and its successor, the teachers college, have been subject to the same conditions that have operated to produce the school system of to-day. Underlying and conditioning the development of the teacher-training institution and the schools which it served is the decentralization of control of education that is characteristic of the American system of government.
Ferroportin is a manganese responsive protein that decreases manganese cytotoxicity and accumulation
Although manganese (Mn) is an essential trace element for human development and growth, chronic exposure to excessive Mn levels can result in psychiatric and motor disturbances, referred to as manganism. However, there are no known mechanism(s) for efflux of excess Mn from mammalian cells. Here, we test the hypothesis that the cytoplasmic iron (Fe) exporter ferroportin (Fpn) may also function as a Mn exporter to attenuate Mn toxicity. Using an inducible human embryonic kidney (HEK293T) cell model, we examined the influence of Fpn expression on Mn-induced cytotoxicity and intracellular Mn concentrations. We found that induction of an Fpn-green fluorescent protein fusion protein in HEK293T cells was cytoprotective against several measures of Mn toxicity, including Mn-induced cell membrane leakage and Mn-induced reductions in glutamate uptake. Fpn-green fluorescent protein mediated cytoprotection correlated with decreased Mn accumulation following Mn exposure. Thus, Fpn expression reduces Mn toxicity concomitant with reduced Mn accumulation. To determine if mammalian cells may utilize Fpn in response to increased intracellular Mn concentrations and toxicity, we assessed endogenous Fpn levels in Mn-exposed HEK293T cells and in mouse brain in vivo. We find that 6 h of Mn exposure in HEK293T cells is associated with a significant increase in Fpn levels. Furthermore, mice exposed to Mn showed an increase in Fpn levels in both the cerebellum and cortex. Collectively, these results indicate that (i) Mn exposure promotes Fpn protein expression, (ii) Fpn expression reduces net Mn accumulation, and (iii) reduces cytotoxicity associated with exposure to this metal
Genetic risk for Parkinson's disease correlates with alterations in neuronal manganese sensitivity between two human subjects.
Manganese (Mn) is an environmental risk factor for Parkinson's disease (PD). Recessive inheritance of PARK2 mutations is strongly associated with early onset PD (EOPD). It is widely assumed that the influence of PD environmental risk factors may be enhanced by the presence of PD genetic risk factors in the genetic background of individuals. However, such interactions may be difficult to predict owing to the complexities of genetic and environmental interactions. Here we examine the potential of human induced pluripotent stem (iPS) cell-derived early neural progenitor cells (NPCs) to model differences in Mn neurotoxicity between a control subject (CA) with no known PD genetic risk factors and a subject (SM) with biallelic loss-of-function mutations in PARK2 and family history of PD but no evidence of PD by neurological exam. Human iPS cells were generated from primary dermal fibroblasts of both subjects. We assessed several outcome measures associated with Mn toxicity and PD. No difference in sensitivity to Mn cytotoxicity or mitochondrial fragmentation was observed between SM and CA NPCs. However, we found that Mn exposure was associated with significantly higher reactive oxygen species (ROS) generation in SM compared to CA NPCs despite significantly less intracellular Mn accumulation. Thus, this report offers the first example of human subject-specific differences in PD-relevant environmental health related phenotypes that are consistent with pathogenic interactions between known genetic and environmental risk factors for PD
Manganese accumulates in iron deficient rat brain regions in a heterogeneous fashion and is associated with neurochemical alterations
Previous studies have shown that iron deficiency (ID) increases brain manganese (Mn), but specific regional changes have not been addressed. Weanling rats were fed one of three semipurified diets: control (CN), iron deficient (ID), or iron deficient/manganese fortified (IDMn+). Seven brain regions were analyzed for Mn concentration and amino acid (glutamate, glutamine, taurine, ?-aminobutyric acid) concentrations. Both ID and IDMn+ diets caused significant (p<0.05) increases in Mn concentration across brain regions compared to CN. The hippocampus was the only brain region in which the IDMn+ group accumulated significantly more Mn than both the CN and ID groups. ID significantly decreased GABA concentration in hippocampus, caudate putamen, and globus pallidus compared to CN rats. Taurine was significantly increased in the substantia nigra of the IDMn+ group compared to both ID and CN. ID also altered glutamate and glutamine concentrations in cortex, caudate putamen, and thalamus compared to CN. In the substantia nigra, Mn concentration positively correlated with increased taurine concentration, whereas in caudate putamen, Mn concentration negatively correlated with decreased GABA. These data show that ID is a significant risk factor for central nervous sys-tem Mn accumulation and that some of the neurochemical alterations associated with ID are specifically attributable to Mn accumulation
Manganese Neurotoxicity
Manganese is an essential trace element and it is required for many ubiquitous enzymatic reactions. While manganese deficiency rarely occurs in humans, manganese toxicity is known to occur in certain occupational settings through inhalation of manganese-containing dust. The brain is particularly susceptible to this excess manganese, and accumulation there can cause a neurodegenerative disorder known as manganism.
Characteristics of this disease are described as Parkinson-like symptoms. The similarities between the two disorders can be partially explained by the fact that the basal ganglia accumulate most of the excess manganese compared with other brain regions in manganism, and dysfunction in the basal ganglia is also the etiology of Parkinson's disease. It has been proposed that populations already at heightened risk for neurodegeneration may also be more susceptible to manganese neurotoxicity, which highlights the importance of investigating the human health effects of using the controversial compound, methylcyclopentadienyl manganese tricarbonyl (MMT), in gasoline to increase octane. The mechanisms by which increased manganese levels can cause neuronal dysfunction and death are yet to be elucidated. However, oxidative stress generated through mitochondrial perturbation may be a key event in the demise of the affected central nervous system cells. Our studies with primary astrocyte cultures have revealed that they are a critical component in the battery of defenses against manganese-induced neurotoxicity. Additionally, evidence for the role of oxidative stress in the progression of manganism is reviewed here
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