Probabilistic hyperspace analogue to language

Song and Bruza introduce a framework for Information Retrieval(IR) based on Gardenfor's three tiered cognitive model; Conceptual Spaces. They instantiate a conceptual space using Hyperspace Analogue to Language (HAL to generate higher order concepts which are later used for ad-hoc retrieval. In this poster, we propose an alternative implementation of the conceptual space by using a probabilistic HAL space (pHAL). To evaluate whether converting to such an implementation is beneficial we have performed an initial investigation comparing the concept combination of HAL against pHAL for the task of query expansion. Our experiments indicate that pHAL outperforms the original HAL method and that better query term selection methods can improve performance on both HAL and pHAL

Heavy particle concentration in turbulence at dissipative and inertial scales

Spatial distributions of heavy particles suspended in an incompressible isotropic and homogeneous turbulent flow are investigated by means of high resolution direct numerical simulations. In the dissipative range, it is shown that particles form fractal clusters with properties independent of the Reynolds number. Clustering is there optimal when the particle response time is of the order of the Kolmogorov time scale $\tau_\eta$. In the inertial range, the particle distribution is no longer scale-invariant. It is however shown that deviations from uniformity depend on a rescaled contraction rate, which is different from the local Stokes number given by dimensional analysis. Particle distribution is characterized by voids spanning all scales of the turbulent flow; their signature in the coarse-grained mass probability distribution is an algebraic behavior at small densities.Comment: 4 RevTeX pgs + 4 color Figures included, 1 figure eliminated second part of the paper completely revise

Cassiopeia A: dust factory revealed via submillimetre polarimetry

If Type-II supernovae - the evolutionary end points of short-lived, massive stars - produce a significant quantity of dust (>0.1 M_sun) then they can explain the rest-frame far-infrared emission seen in galaxies and quasars in the first Gyr of the Universe. Submillimetre observations of the Galactic supernova remnant, Cas A, provided the first observational evidence for the formation of significant quantities of dust in Type-II supernovae. In this paper we present new data which show that the submm emission from Cas A is polarised at a level significantly higher than that of its synchrotron emission. The orientation is consistent with that of the magnetic field in Cas A, implying that the polarised submm emission is associated with the remnant. No known mechanism would vary the synchrotron polarisation in this way and so we attribute the excess polarised submm flux to cold dust within the remnant, providing fresh evidence that cosmic dust can form rapidly. This is supported by the presence of both polarised and unpolarised dust emission in the north of the remnant, where there is no contamination from foreground molecular clouds. The inferred dust polarisation fraction is unprecedented (f_pol ~ 30%) which, coupled with the brief timescale available for grain alignment (<300 yr), suggests that supernova dust differs from that seen in other Galactic sources (where f_pol=2-7%), or that a highly efficient grain alignment process must operate in the environment of a supernova remnant.Comment: In press at MNRAS, 10 pages, print in colou

Raman excitation spectroscopy of carbon nanotubes: effects of pressure medium and pressure

Raman excitation and emission spectra for the radial breathing mode (RBM) are reported, together with a preliminary analysis. From the position of the peaks on the two-dimensional plot of excitation resonance energy against Raman shift, the chiral indices (m, n) for each peak are identified. Peaks shift from their positions in air when different pressure media are added - water, hexane, sulphuric acid - and when the nanotubes are unbundled in water with surfactant and sonication. The shift is about 2 - 3 cm-1 in RBM frequency, but unexpectedly large in resonance energy, being spread over up to 100meV for a given peak. This contrasts with the effect of pressure. The shift of the peaks of semiconducting nanotubes in water under pressure is orthogonal to the shift from air to water. This permits the separation of the effects of the pressure medium and the pressure, and will enable the true pressure coefficients of the RBM and the other Raman peaks for each (m, n) to be established unambiguously.Comment: 6 pages, 3 Figures, Proceedings of EHPRG 2011 (Paris

Inferencing Abilities of Deaf College Students: Foundations and Implications for Metaphor Comprehension and Theory of Mind

Understanding nonliteral language requires inferencing ability and is an important but complex aspect of social interaction, involving cognitive (e.g., theory of mind, executive function) as well as language skill, areas in which many deaf individuals struggle. This study examined comprehension of metaphor and sarcasm, assessing the contributions of hearing status, inferencing ability, executive function (verbal short-term/working memory capacity), and deaf individuals’ communication skills (spoken versus signed language, cochlear implant use). Deaf and hearing college students completed a multiple-choice metaphor comprehension task and inferencing tasks that included both social-emotional (i.e., theory of mind) and neutral inferences, as well as short-term memory span and working memory tasks. Results indicated the hearing students to have better comprehension of nonliteral language and the ability to make social-emotional inferences, as well as greater memory capacity. Deaf students evidenced strong relationships among inferential comprehension, communication skills, and memory capacity, with substantial proportions of the variance in understanding of metaphor and sarcasm accounted for by these variables. The results of this study enhance understanding of the language and cognitive skills underlying figurative language comprehension and theory of mind and have implications for the social functioning of deaf individuals

Deep Space Network information system architecture study

The purpose of this article is to describe an architecture for the Deep Space Network (DSN) information system in the years 2000-2010 and to provide guidelines for its evolution during the 1990s. The study scope is defined to be from the front-end areas at the antennas to the end users (spacecraft teams, principal investigators, archival storage systems, and non-NASA partners). The architectural vision provides guidance for major DSN implementation efforts during the next decade. A strong motivation for the study is an expected dramatic improvement in information-systems technologies, such as the following: computer processing, automation technology (including knowledge-based systems), networking and data transport, software and hardware engineering, and human-interface technology. The proposed Ground Information System has the following major features: unified architecture from the front-end area to the end user; open-systems standards to achieve interoperability; DSN production of level 0 data; delivery of level 0 data from the Deep Space Communications Complex, if desired; dedicated telemetry processors for each receiver; security against unauthorized access and errors; and highly automated monitor and control

Exploring the impact of Osteogenesis Imperfecta on families: A mixed-methods systematic review

Background: Osteogenesis Imperfecta (OI) is a rare genetic condition whose key characteristic is increased bone fragility. OI has the potential to impact upon all family members, making it important to consider the challenges families face, how they cope and their support needs as the affected individual moves from childhood through to adult life. / Objective: To conduct a mixed-methods systematic review investigating the experiences of families when a family member is affected with OI. / Methods: A systematic search of seven electronic databases, relevant patient organisation websites and reference lists was conducted. Data extraction was performed for all studies that met the eligibility and quality criteria. Results were synthesised following the principles of thematic analysis. / Results: One mixed-method, six qualitative and six quantitative studies were included in the review. Three overarching themes were identified through thematic analysis: Impact of OI on the psychosocial wellbeing of families, impact on family life and evolving roles and relationships. Fear of fractures and the uncertainty of when the next fracture will occur are key issues that permeate all areas of family life and impact upon all family members. / Conclusion: The experiences, coping strategies and support needs of families affected by OI were highly variable and changed over time. Future research should address the need for adaptive health and education interventions that support all family members

Growth and Empowerment for Indigenous Australians in Substance Abuse Treatment

This paper describes psychosocial outcomes of an Indigenous residential substance abuse rehabilitation centre in Australia, examines the sensitivity to change of the new Growth and Empowerment Measure (GEM), and explores the degree to which service users value cultural components of the treatment program. Participants were 57 Indigenous and 46 non-Indigenous male clients from Oolong House. Intake, 8-weeks, and 16-weeks (program completion) measures of Kessler 10 Psychological Distress Scale (K10), Drug Taking Confidence Questionnaire (DTCQ-8), and GEM were completed. The Treatment Component Evaluation (TCE) was completed at 16-weeks. There were significant improvements for participants, with a decrease in psychological distress and increases in refusal self-efficacy and empowerment. Effect sizes for GEM were medium to large across the time-points (r00.61 to 0.70 for all four subscales from baseline to 8-weeks; r00.44 to 0.70 for three subscales from 8-weeks to 16-weeks), indicating sensitivity to change. Indigenous participants rated cultural components of treatment significantly more helpful than did non-Indigenous participants. Implications for future research and substance abuse interventions for Indigenous Australians are discussed

Dental students’ experience of conscious sedation: A qualitative review of student reflections

Introduction The UK General Dental Council (GDC) requires dental graduates to competently identify, manage and refer patients with dental pain and anxiety. This study aimed to explore sedation training experience quantitatively and qualitatively through individual reflective logs. Materials & Methods A single-centred mixed-methods evaluation of teaching, within a UK university conscious sedation department. Fourth-year dental students undertook lectures and supervised clinical sessions following the undergraduate curriculum. Patient attendance patterns, individual experience and group experience were analysed descriptively. Reflective log sheets were analysed by Thematic Framework Analysis. Results Seventy-two students participated. Of 153 booked patients, 79 (51.6%) attended of which 74 (48.4%) were treated by undergraduates. The mean performed inhalation sedation and intravenous sedation cases per student were 1 and 0.8, respectively. Three students (4%) assisted only. Group experience varied. Three themes arose from reflections: consolidation of theory and learning; confidence through experience; and responding to challenges. Discussion Whilst experience quotas were not met, GDC requirements for increasing students’ knowledge and confidence within CS were met. Practical experience enhanced learning. “Hands-on” experience was most valuable for self-reported confidence but learning by proxy also aided development. Students recognised challenges, but not the implications for themselves or their career. Strategies to reduce barriers to experience require research. Conclusion Whilst variable, all students were provided learning opportunities. Physical experience gave the greatest confidence. Opportunities afforded by the undergraduate curriculum allowed students to learn and develop through consolidation of theory, response to challenges and ultimately the gaining of confidence