Systems, interactions and macrotheory

A significant proportion of early HCI research was guided by one very clear vision: that the existing theory base in psychology and cognitive science could be developed to yield engineering tools for use in the interdisciplinary context of HCI design. While interface technologies and heuristic methods for behavioral evaluation have rapidly advanced in both capability and breadth of application, progress toward deeper theory has been modest, and some now believe it to be unnecessary. A case is presented for developing new forms of theory, based around generic “systems of interactors.” An overlapping, layered structure of macro- and microtheories could then serve an explanatory role, and could also bind together contributions from the different disciplines. Novel routes to formalizing and applying such theories provide a host of interesting and tractable problems for future basic research in HCI

Cumulative luminosity functions of the X-ray point source population in M31

We present preliminary results from a detailed analysis of the X-ray point sources in the XMM-Newton survey of M31. These sources are expected to be mostly X-ray binaries. We have so far studied 225 of the 535 sources found by automated source detection. Only sources which were present in all three EPIC images were considered. X-ray binaries are identified by their energy spectrum and power density spectrum. Unlike in other surveys we have obtained source luminosities from freely fit emission models. We present uncorrected luminosity functions of the sources analysed so far.Comment: 2 pages, 1 figure. To appear in proceedings of IAUS23

Submerged in the mainstream? A case study of an immigrant learner in a New Zealand primary classroom

Immigrant children from diverse language backgrounds face not only linguistic challenges when enrolled in mainstream English-medium classrooms, but also difficulties adjusting to an unfamiliar learning community. The culture of primary school classrooms in New Zealand typically reflects conventions across three dimensions: interactional, instructional task performance and cognitive-academic development. All three dimensions are underpinned by the culturally specific discourse conventions involved in language socialisation. New learners may be helped by classmates or their teacher to understand and successfully use these conventions, but left on their own they may sink rather than swim. This is a case study of one Taiwanese 11-year old boy, 'John', who entered a New Zealand primary classroom midway through the school year. John's basic conversational ability was sound, but he did not possess the interactive classroom skills needed to operate in the new culture of learning. Selected from a wider study of the classroom, transcript data from audio-recorded excerpts of John's interactions over several months with his teacher and classmates are interpreted from perspectives derived from sociocultural and language socialisation theories. The article concludes with a brief consideration of the extent to which John constructed, or was constrained from constructing meaningful learning experiences, and suggestions for further research and reflection

Oxidation Behavior of a Pd_(43)Cu_(27)Ni_(10)P_(20) Bulk Metallic Glass and Foam in Dry Air

The oxidation behavior of both Pd_(43)Cu_(27)Ni_(10)P_(20) bulk metallic glass (Pd4-BMG) and its amorphous foam containing 45 pct porosity (Pd4-AF) was investigated over the temperature range of 343 K (70 °C) to 623 K (350 °C) in dry air. The results showed that virtually no oxidation occurred in the Pd4-BMG at T < 523 K (250 °C), revealing the alloy’s favorable oxidation resistance in this temperature range. In addition, the oxidation kinetics at T ≥ 523 K (250 °C) followed a parabolic-rate law, and the parabolic-rate constants (k_p values) generally increased with temperature. It was found that the oxidation k_p values of the Pd4-AF are slightly lower than those of the Pd4-BMG, indicating that the porous structure contributes to improving the overall oxidation resistance. The scale formed on the alloys was composed exclusively of CuO at T ≥ 548 K (275 °C), whose thickness gradually increased with increasing temperature. In addition, the amorphous structure remained unchanged at T ≤ 548 K (275 °C), while a triplex-phase structure developed after the oxidation at higher temperatures, consisting of Pd_2Ni_2P, Cu_3P, and Pd_3P

A model integrating longshore and cross-shore processes for predicting long-term shoreline responses to climate change

We present a shoreline change model for coastal hazard assessment and management planning. The model, CoSMoS-COAST (Coastal One-line Assimilated Simulation Tool), is a transect-based, one-line model that predicts short-term and long-term shoreline response to climate change in the 21st century. The proposed model represents a novel, modular synthesis of process-based models of coastline evolution due to longshore and cross-shore transport by waves and sea level rise. Additionally, the model uses an extended Kalman filter for data assimilation of historical shoreline positions to improve estimates of model parameters and thereby improve confidence in long-term predictions. We apply CoSMoS-COAST to simulate sandy shoreline evolution along 500 km of coastline in Southern California, which hosts complex mixtures of beach settings variably backed by dunes, bluffs, cliffs, estuaries, river mouths, and urban infrastructure, providing applicability of the model to virtually any coastal setting. Aided by data assimilation, the model is able to reproduce the observed signal of seasonal shoreline change for the hindcast period of 1995–2010, showing excellent agreement between modeled and observed beach states. The skill of the model during the hindcast period improves confidence in the model’s predictive capability when applied to the forecast period (2010–2100) driven by GCM-projected wave and sea level conditions. Predictions of shoreline change with limited human intervention indicate that 31% to 67% of Southern California beaches may become completely eroded by 2100 under sea level rise scenarios of 0.93 to 2.0 m

XMM-Newton reveals ~100 new LMXBs in M31 from variability studies

We have conducted a survey of X-ray sources in XMM-Newton observations of M31, examining their power density spectra (PDS) and spectral energy distributions (SEDs). Our automated source detection yielded 535 good X-ray sources; to date, we have studied 225 of them. In particular, we examined the PDS because low mass X-ray binaries (LMXBs) exhibit two distinctive types of PDS. At low accretion rates, the PDS is characterised by a broken power law, with the spectral index changing from ~0 to ~1 at some frequency in the range \~0.01--1 Hz; we refer to such PDS as Type A. At higher accretion rates, the PDS is described by a simple power law; we call these PDS Type B. Of the 225 sources studied to date, 75 exhibit Type A variability, and are almost certainly LMXBs, while 6 show Type B but not Type A, and are likely LMXBs. Of these 81 candidate LMXBs, 71 are newly identified in this survey; furthermore, they are mostly found near the centre of M31. Furthermore, most of the X-ray population in the disc are associated with the spiral arms, making them likely high mass X-ray binaries (HMXBs). In general these HMXBs do not exhibit Type A variability, while many central X-ray sources (LMXBs) in the same luminosity range do. Hence the PDS may distinguish between LMXBs and HMXBs in this luminosity range.Comment: 4 pages, 2 figures. To appear in proceedings of IAUS230: "Populations of High Energy Sources in Galaxies", 14-19 August 2005, Dublin, Eds E.J.A. Meurs and G. Fabbian

Six Years of ScoX-1 Monitoring with BeppoSAX Wide Field Cameras

We performed a systematic analysis of 54 Wide Field Camera (WFC) observations of ScoX-1 available in the BeppoSAX public archive. Observations span over the six years of BeppoSAX mission lifetime and include 690 hr of data. We searched for shifts and shape changes of the Z pattern in the color-color diagrams. We find that the Z pattern occupies most of the time the same locus in the color-color diagram. There are however a few exceptions, which are discussed in detail.Comment: 4 Pages, 4 figures. To appear in Proc. of the BeppoSAX Symposium: "The Restless High-Energy Universe", E.P.J. van den Heuvel, J.J.M. in 't Zand, and R.A.M.J. Wijers (Eds

The seminal legacy of the Southern African Bird Atlas Project

The first Southern African Bird Atlas Project was launched in 1986 and gathered bird distribution data from six countries of southern Africa. The project culminated with the publication of The Atlas of Southern African Birds in 1997. The database generated by the project, seven million bird distribution records, has been widely used by four groups: environmental consultants (for example, to locate electricity transmission lines), conservationists (planning conservation strategies), research scientists (especially macro-ecologists and biogeographers) and birders (ecotourism materials). By 2007, the database had spawned 50 research publications and eight Ph.D.s and master's degrees. These products are a tribute to the more than 5000 'citizen scientists', who gathered the bulk of the data. The atlas concept has been extended to frogs, reptiles, spiders and butterflies; a second bird atlas started in 2007 and will, for example, facilitate knowledge of the impact of environmental change on birds. The South African National Biodiversity Institute is playing a lead role in initiating these new projects

Hospitalisation of Type 2 diabetes mellitus patients with and without major depressive disorder in a private managed healthcare organisation

Background: The relationship between Type 2 diabetes mellitus (T2DM) and associated co-morbidities, particularly major depressive disorder (MDD), is poorly acknowledged in chronic disease management practices in South Africa. Managed healthcare costs and hospitalisation rates may be influenced by the discrete management of co-morbid conditions. Therefore, the relationship between T2DM and MDD in terms of co-morbidity incidence and hospitalisation resource utilisation was investigated.Method: This retrospective descriptive study analysed the data of 902 adult patients with T2DM from the health system database of a private managed healthcare organisation for 2014.Results: The mean age was 57 ± 15 years and 85% of the identified T2DM patients had at least one recorded co-morbidity. Among this population 17% presented with MDD. A higher percentage of T2DM patients with MDD were admitted to hospital (42%, p = 0.004) compared with those without MDD (30%). The number of overnight admissions was higher among the T2DM with MDD (76%, p = 0.016) compared with T2DM without MDD (66%). The T2DM with MDD group (85%, p = 0.018) had greater non-diabetes related hospital events compared with the T2DM without MDD group (73%). The T2DM patients without MDD were more likely to be hospitalised for diabetes-related events (27%, p = 0.018) at significantly higher admission cost (p = 0.001).Conclusion: Patients with T2DM and MDD present with more co-morbid conditions and had a higher number of hospitalisations than their non-MDD counterparts. However, the hospitalisation costs were significantly higher for diabetes-related admissions in the non-MDD group due to a higher number of macrovascular events. Healthcare organisations need to focus on an integrated approach in the management of chronic conditions with emphasis on active surveillance of T2DM patients, where MDD is identified and treated to lessen the risk of macrovascular complications