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

On the artificial nature of aperiodic variability in XMM-Newton observations of M 31 X-ray sources and the ultraluminous X-ray source NGC 4559 ULX-7

Context: Power density spectra (PDS) that are characteristic of low mass X-ray binaries (LMXBs) have been previously reported for M 31 X-ray sources, observed by XMM-Newton. However, we have recently discovered that these PDS result from the improper addition/subtraction of non-simultaneous lightcurves. Aims: To understand the properties and origins of the artefact. Methods: We re-analysed our XMM-Newton observations of M 31 with non-simultaneous and simultaneous lightcurves, then combined simulated lightcurves at various intensities with various offsets and found that the artefact is more dependent on the offset than the intensity. Results: The lightcurves produced by the XMM-Newton Science Analysis Software (SAS) are non-synchronised by default. This affects not only the combination of lightcurves from the three EPIC detectors (MOS1, MOS2 and pn), but also background subtraction in the same CCD. It is therefore imperative that all SAS-generated lightcurves are synchronised by time filtering, even if the whole observation is to be used. We also find that the reported timing behaviour for NGC 4559 ULX-7 was also contaminated by the artefact; there is no significant variability in the correctly-combined lightcurves of NGC 4559 ULX-7. Hence, the classification of this source as an intermediate-mass black hole is no longer justified. Conclusions: While previous timing results from M 31 have been proven wrong, and also the broken power law PDS in NGC 4559 ULX-7, XMM-Newton was able to detect aperiodic variability in just 3 ks of observations of NGC 5408 ULX1. Hence XMM-Newton remains a viable tool for analysing variability in extra-galactic X-ray sources

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

SCUBA observations of the host galaxies of four dark gamma-ray bursts

We present the results of a search for submillimetre-luminous host galaxies of optically dark gamma-ray bursts (GRBs) using the Submillimetre Common-User Bolometer Array (SCUBA) on the James Clerk Maxwell Telescope (JCMT). We made photometry measurements of the 850-micron flux at the location of four `dark bursts', which are those with no detected optical afterglow despite rapid deep searches, and which may therefore be within galaxies containing substantial amounts of dust. We were unable to detect any individual source significantly. Our results are consistent with predictions for the host galaxy population as a whole, rather than for a subset of dusty hosts. This indicates that optically dark GRBs are not especially associated with very submillimetre-luminous galaxies and so cannot be used as reliable indicators of dust-enshrouded massive star-formation activity. Further observations are required to establish the relationship between the wider GRB host galaxy population and SCUBA galaxies.Comment: 6 pages. Accepted for publication in MNRA

‘O sibling, where art thou?’ – a review of avian sibling recognition with respect to the mammalian literature

Avian literature on sibling recognition is rare compared to that developed by mammalian researchers. We compare avian and mammalian research on sibling recognition to identify why avian work is rare, how approaches differ and what avian and mammalian researchers can learn from each other. Three factors: (1) biological differences between birds and mammals, (2) conceptual biases and (3) practical constraints, appear to influence our current understanding. Avian research focuses on colonial species because sibling recognition is considered adaptive where ‘mixing potential’ of dependent young is high; research on a wider range of species, breeding systems and ecological conditions is now needed. Studies of acoustic recognition cues dominate avian literature; other types of cues (e.g. visual, olfactory) deserve further attention. The effect of gender on avian sibling recognition has yet to be investigated; mammalian work shows that gender can have important influences. Most importantly, many researchers assume that birds recognise siblings through ‘direct familiarisation’ (commonly known as associative learning or familiarity); future experiments should also incorporate tests for ‘indirect familiarisation’ (commonly known as phenotype matching). If direct familiarisation proves crucial, avian research should investigate how periods of separation influence sibling discrimination. Mammalian researchers typically interpret sibling recognition in broad functional terms (nepotism, optimal outbreeding); some avian researchers more successfully identify specific and testable adaptive explanations, with greater relevance to natural contexts. We end by reporting exciting discoveries from recent studies of avian sibling recognition that inspire further interest in this topic

Ultralow-threshold, continuous-wave upconverting lasing from subwavelength plasmons.

Miniaturized lasers are an emerging platform for generating coherent light for quantum photonics, in vivo cellular imaging, solid-state lighting and fast three-dimensional sensing in smartphones1-3. Continuous-wave lasing at room temperature is critical for integration with opto-electronic devices and optimal modulation of optical interactions4,5. Plasmonic nanocavities integrated with gain can generate coherent light at subwavelength scales6-9, beyond the diffraction limit that constrains mode volumes in dielectric cavities such as semiconducting nanowires10,11. However, insufficient gain with respect to losses and thermal instabilities in nanocavities has limited all nanoscale lasers to pulsed pump sources and/or low-temperature operation6-9,12-15. Here, we show continuous-wave upconverting lasing at room temperature with record-low thresholds and high photostability from subwavelength plasmons. We achieve selective, single-mode lasing from Yb3+/Er3+-co-doped upconverting nanoparticles conformally coated on Ag nanopillar arrays that support a single, sharp lattice plasmon cavity mode and greater than wavelength λ/20 field confinement in the vertical dimension. The intense electromagnetic near-fields localized in the vicinity of the nanopillars result in a threshold of 70 W cm-2, orders of magnitude lower than other small lasers. Our plasmon-nanoarray upconverting lasers provide directional, ultra-stable output at visible frequencies under near-infrared pumping, even after six hours of constant operation, which offers prospects in previously unrealizable applications of coherent nanoscale light

Thin liquid water clouds: their importance and our challenge

Many clouds important to the Earth’s energy balance contain small amounts of liquid water, yet despite many improvements, large differences in retrievals of their liquid water amount and particle size still must be resolved

Authentic Leadership: A Historical Perspective

The purpose of this paper is to interpret the historical meanings conveyed by Barnard's classic works and use them for theorizing about authenticity of leaders in executive roles. Our analysis employs an interpretative logic for meanings of historical ideas proposed by Bevir. As an outcome of this analysis, we identify the conditions that contribute to the failure, crisis, tragedy, and/or success of leader authenticity. In addition, we discuss practical and research implications of the proposed framework.Yeshttps://us.sagepub.com/en-us/nam/manuscript-submission-guideline

Full effects of land use change in the representative concentration pathways

Future land use change (LUC) is an important component of the IPCC representative concentration pathways (RCPs), but in these scenarios' radiative forcing targets the climate impact of LUC only includes greenhouse gases. However, climate effects due to physical changes of the land surface can be as large. Here we show the critical importance of including non-carbon impacts of LUC when considering the RCPs. Using an ensemble of climate model simulations with and without LUC, we show that the net climate effect is very different from the carbon-only effect. Despite opposite signs of LUC, all the RCPs assessed here have a small net warming from LUC because of varying biogeophysical effects, and in RCP4.5 the warming is outside of the expected variability. The afforestation in RCP4.5 decreases surface albedo, making the net global temperature anomaly over land around five times larger than RCPs 2.6 and 8.5, for around twice the amount of LUC. Consequent changes to circulation in RCP4.5 in turn reduce Arctic sea ice cover. The small net positive temperature effect from LUC could make RCP4.5's universal carbon tax, which incentivizes retaining and growing forest, counter productive with respect to climate. However, there are spatial differences in the balance of impacts, and potential climate gains would need to be assessed against other environmental aims

From vocational training to education: the development of a no-frontiers education policy for Europe?

This article focuses on developments towards an EU educational policy. Education was not included as one of the Community competencies in the Treaty of Rome. The first half of the article analyses the way that the European Court of Justice and the Commission of the European Communities between them managed to develop a series of substantial Community programmes out of Article 128 on vocational training. The second half of the article discusses educational developments in the community following the Treaty on European Union and the Treaty of Amsterdam. Whilst the legal competence of the community now includes education, the author's argument is that the inclusion of an educational competence will not result in further developments to mirror those in the years before the Treaty on Europe</p