7,150 research outputs found

    Dual task impairments in vascular dementia

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    Several studies have shown that people with Alzheimer's disease (AD) demonstrate difficulties in doing two things at once or 'dual-tasking' and that this dual task impairment is insensitive to normal ageing, chronic depression or prodromal conditions like Mild Cognitive Impairment. It is not known, however, if this impairment is specific to AD, or also present in other dementias, such as vascular dementia (VaD). In this study 15 people with VaD, 25 healthy age-matched and 25 healthy young controls were assessed using a paper and pencil dual tasking paradigm and several measures of working and episodic memory. Age had no effect on dual task performance, but the VaD patients demonstrated a significant impairment in dual tasking ability. Performance on the memory measures was instead affected by age with a further deterioration in the VaD patients. Both dual tasking and memory ability were significantly correlated with disease severity, as assessed by the MMSE. These results indicate that performance on the dual task could be a specific indicator of pathological ageing

    Geostatistical interpretation of paleoceanographic data over large ocean basins - Reality and fiction

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    A promising approach to reconstruct oceanographic scenarios of past time slices is to drive numerical ocean circulation models with sea surface temperatures, salinities, and ice distributions derived from sediment core data. Set up properly, this combination of boundary conditions provided by the data and physical constraints represented by the model can yield physically consistent sets of three-dimensional water mass distribution and circulation patterns. This idea is not only promising but dangerous, too. Numerical models cannot be fed directly with data from single core locations distributed unevenly and, as it is the common case, scarcely in space. Conversely, most models require forcing data sets on a regular grid with no missing points, and some method of interpolation between punctual source data and model grid has to be employed. An ideal gridding scheme must retain as much of the information present in the sediment core data while generating as few artifacts in the interpolated field as possible. Based on a set of oxygen isotope ratios, we discuss several standard interpolation strategies, namely nearest neighbour schemes, bicubic splines, Delaunay triangulation, and ordinary and indicator kriging. We assess the gridded fields with regard to their physical consistence and their implications for the oceanic circulation

    What memory binding functions is the hippocampus responsible for?

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    The role of the hippocampus in binding information in working memory (WM) is little understood. When complex experiences comprise associations between different pieces of information such as objects and locations (relational binding), the function of the hippocampus is required to hold them in WM (Mitchell et al., 2000; 2006; Piekema, 2006). However, recent evidence suggests that if the to-be-associated information leads to the formation of integrated objects such as coloured shapes (conjunctive binding), the hippocampus is less involved in holding temporary representations of these complex events in WM (Baddeley et al., 2010; Piekema, 2006). We investigated the relational and conjunctive binding hypotheses of the hippocampal functions in a patient with right hippocampal damage. The patient and controls were asked to study visual arrays of stimuli which consisted of shape-colour relations (shape-colour pairs) or shape-colour conjunctions (coloured shapes). After the study array, they were presented with a new screen consisting of one set of shapes (line drawings) and one set of colours. They were asked to reconstruct the bindings by selecting the shapes and their corresponding colours. As compared to healthy controls, the patient was impaired in holding relations of shapes and colours in WM whereas he could retain the conjunctions similarly to controls. These results lend support to the role of the hippocampus in supporting memory for inter-item associations but not memory for conjunctions of features which define objects' identity

    Looking for black-holes in X-ray binaries with XMM-Newton: XTE J1817-330 and XTE J1856+053

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    The X-ray binary XTE J1817-330 was discovered in outburst on 26 January 2006 with RXTE/ASM. One year later, another X-ray transient discovered in 1996, XTE J1856+053, was detected by RXTE during a new outburst on 28 February 2007. We triggered XMM-Newton target of opportunity observations on these two objects to constrain their parameters and search for a stellar black holes. We summarize the properties of these two X-ray transients and show that the soft X-ray spectra indicate indeed the presence of an accreting stellar black hole in each of the two systems.Comment: to appear in the proceedings of the Second Kolkata Conference on Observational Evidence for Black Holes in the Universe, Feb. 2008, Editor Sandip Chakrabarti, AI

    The new look; transforming sustainable fashion education

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    This research examines transformative learning theory's impact for fashion education. Through a study of current learning and teaching practices employed by educators within the field of fashion education for sustainability, this research finds that transformative teaching strategies can contribute to the effectiveness of students understanding of sustainable fashion. Additionally, this research illustrates how promoting the use of these learning and teaching methods will support opportunities for students to grow through critical reflection and collaboration, with an emphasis on participation and collective inquiry; strategies supported through a mutual and dynamic learning environment. The fashion and textile industries provide work to one in six people globally (Morgan, 2015). Considering the fashion industry's global influence, this field has become a popular career choice for many young graduates (Jenkyn-Jones, 2011). According to Jenkyn-Jones fashion design is one of the most oversubscribed fields in higher education (2011, p. 6). In light of this growth in popularity, fashion institutions are left to manage student preconceptions of the fashion industry; at times these are uninitiated ideas propagated by fashion media and brands who promote the notion of the celebrity fashion designer, working in isolation, relatively free of social responsibility (Jenkyn-Jones, 2015; Edelkoort, 2014). In contrast to these widely promoted ideas of how the fashion industry operates, a fashion education aims to develop the skills required of a student in order to gain employment in the industry, both present and future, and in doing so, highlight the diverse functions and applications of fashion design practices. In addition to these skills, a fashion education is also an ideal environment to engage with specific learning and teaching strategies that will help facilitate student discussion and learning of issues associated with the influential choices fashion designers make, and how these choices impact our local and global communities. Through this research, it has become evident that neither education theory (transformative learning theory) nor design theory (studio practice) has given adequate consideration to the advancement of appropriate learning and teaching methods to enable fashion to respond to the social and environmental challenges of the future. Literature on fashion education for sustainability is abundant, as is research exploring the application of transformative learning theory in disciplines outside of fashion. What is yet to be addressed through current literature are the distinct needs, as well as issues, arguing for the advancement and development of learning and teaching practice specific to fashion design education. This research contributes to a greater understanding of contemporary education practice within fashion design through an analysis of discipline-specific application of transformative learning theory to fashion pedagogy. An analysis of current literature indicates that transformative learning theory appears to be the main driver for change when delivering content regarding sustainability at a tertiary level within similar design disciplines such as architectural education. Data gathered from multiple methods for this research reveals a correlation between best teaching practice for education for sustainability and transformative teaching strategies. The literature review is organised into four areas of inquiry: sustainability, fashion design and the nature of change; the evolving forms of fashion design education; the fashion educator and the future; and transformative learning theory in higher education. Additionally a review of a select number of international fashion programmes offering fashion education for sustainability has been included. The research from this last section feeds into the development of a comparative study, from which key subsequent findings evolved. The aim of the comparative study was to identify existing trends in international pedagogical innovation and to establish a connection between these trends and transformative learning teaching practice in a tertiary fashion education setting. A number of different approaches have been taken to complete this research, these include: a literature review, a range of semi-structured interviews and online surveys, a comparative study of fashion design teaching methods, as well as the development of strategies for transformative fashion teaching practice. In addition to identifying and analysing best-practice teaching for fashion sustainability, the findings of this research are geared towards equipping students and educators alike with the tools to critically reflect upon, and work towards, ethical and responsive possibilities for transformation in their own fashion teaching and learning practices. The results from the semi-structured interviews and online surveys, combined with written reflection based on observation and literature research, formed the foundation for the comparative study of four leading international undergraduate fashion design courses. The key educators interviewed regarding their involvement in delivering these courses, are globally renowned for their contributions to sustainable fashion theory and practice, and thus are in a position to provide valuable insight from which comparative findings have been established. A key discovery from this process identified that the learning and teaching methods employed by these educators reflected an approach to teaching that correlates with the application of transformative learning theory. In addition, several students who participated in these courses took part in an anonymous online survey, from which an understanding of how these courses compared, in regard to student experience, was attained. The comparative study within this research demonstrated how integrating transformative learning theory and its associated teaching strategies with more common and traditional practices of fashion education, developed an environment that enabled student designers to critically reflect on sustainable methods for fashion design practice. This research seeks to ground this theoretical and practical ambition in the realities of fashion education practices and the systems of tertiary higher education institutions, while unpacking the possibilities that lie in the adaption of the theory to fashion teaching practice, in preparation for a transformation of current realities

    Any-k: Anytime Top-k Tree Pattern Retrieval in Labeled Graphs

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    Many problems in areas as diverse as recommendation systems, social network analysis, semantic search, and distributed root cause analysis can be modeled as pattern search on labeled graphs (also called "heterogeneous information networks" or HINs). Given a large graph and a query pattern with node and edge label constraints, a fundamental challenge is to nd the top-k matches ac- cording to a ranking function over edge and node weights. For users, it is di cult to select value k . We therefore propose the novel notion of an any-k ranking algorithm: for a given time budget, re- turn as many of the top-ranked results as possible. Then, given additional time, produce the next lower-ranked results quickly as well. It can be stopped anytime, but may have to continues until all results are returned. This paper focuses on acyclic patterns over arbitrary labeled graphs. We are interested in practical algorithms that effectively exploit (1) properties of heterogeneous networks, in particular selective constraints on labels, and (2) that the users often explore only a fraction of the top-ranked results. Our solution, KARPET, carefully integrates aggressive pruning that leverages the acyclic nature of the query, and incremental guided search. It enables us to prove strong non-trivial time and space guarantees, which is generally considered very hard for this type of graph search problem. Through experimental studies we show that KARPET achieves running times in the order of milliseconds for tree patterns on large networks with millions of nodes and edges.Comment: To appear in WWW 201

    Bowen ratio estimates of evapotranspiration for stands on the Virgin River in Southern Nevada

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    A Bowen ratio energy balance was conducted over a Tamarix ramosissima (saltcedar) stand growing in a riparian corridor along the Virgin River in southern Nevada. Measurements in two separate years were compared and contrasted on the basis of changes in growing conditions. In 1994, a drought year, record high temperatures, dry winds, and a falling water table caused partial wilt of outer smaller twigs in the canopy of many trees in the stand around the Bowen tower. Subsequently, evapotranspiration (ET) estimates declined dramatically over a 60‐day period (11 mm d−1 tod−1). In 1995, the Virgin River at the Bowen tower area changed its course, hydrologically isolating the Tamarix stand in the vicinity of the tower. In 1996, a 25% canopy loss was visually estimated for the Tamarix growing in the area of the tower. Higher soil temperatures relative to air temperatures were recorded in 1996 in response to this loss in canopy. With a more open canopy, thermally induced turbulence was observed in 1996. On day 160 of 1996, a 28°C rise over a 9‐hour period was correlated with increased wind speeds of greater than 4 m s−1. Subsequently, higher ET estimates were made in 1996 compared to 1994 (145 cm versus 75 cm). However, the energy balance was dominated by advection in 1996, with latent energy flux exceeding net radiation 65% of the measurement days compared to only 11% in 1994. We believe this advection was on a scale of the floodplain (hundreds of meters) as opposed to regional advection, since the majority of wind (90%) was in a N–S direction along the course of the river, and that a more open canopy allowed the horizontal transfer of energy into the Tamarix stand at the Bowen tower. Our results suggest that Tamarix has the potential to be both a low water user and a high water user, depending on moisture availability, canopy development, and atmospheric demand, and that advection can dominate energy balances and ET in aridland riparian zones such as the Virgin River
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