70 research outputs found

    Evaluation of curriculum online: Report of the qualitative study of schools year two

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    Blue-Light-Emitting Color Centers in High-Quality Hexagonal Boron Nitride

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    Light emitters in wide band gap semiconductors are of great fundamental interest and have potential as optically addressable qubits. Here we describe the discovery of a new color center in high-quality hexagonal boron nitride (h-BN) with a sharp emission line at 435 nm. The emitters are activated and deactivated by electron beam irradiation and have spectral and temporal characteristics consistent with atomic color centers weakly coupled to lattice vibrations. The emitters are conspicuously absent from commercially available h-BN and are only present in ultra-high-quality h-BN grown using a high-pressure, high-temperature Ba-B-N flux/solvent, suggesting that these emitters originate from impurities or related defects specific to this unique synthetic route. Our results imply that the light emission is activated and deactivated by electron beam manipulation of the charge state of an impurity-defect complex

    Improving children's social care services: results of a feasability study.

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    This report sets out the findings of a feasibility study that aimed to understand how to define ‘good’ children’s social care services and how to assess whether they have improved. The intention was for the feasibility study to support a larger project exploring the processes involved in improving children’s social care services. The key findings of the study are: ‱ There is a lack of consistent expectations about outcomes for children’s social care services and what indicators should be used to monitor them. There is mixed evidence about the features that characterise good children’s social care services, and a significant proportion of it is based on expert opinion and has not been tested quantitatively. ‱ Analysis of the relationship between outcome data for children in need collated nationally by the Department for Education and Ofsted ratings of children’s services found very little association. There did not seem to be any pattern in terms of the local authorities that were in the top or bottom percentiles for child outcome. Only one child outcome variable and one workforce variable had a statistically significant relationship with the Ofsted ratings. ‱ Before proceeding with a study exploring how children’s social care services improve, it is important to identify an outcomes framework that a wide range of stakeholders agree is appropriate and to establish a set of indicators that reflect these outcomes and that could be collected and collated at a national level. ‱ The study team concluded that at this time it is not feasible to go ahead with the main project as originally envisaged, and instead to focus on how to create an outcomes framework and establish an appropriate set of indicators

    Planet Migration and Disk Destruction due to Magneto-Centrifugal Stellar Winds

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    This paper investigates the influence of magneto-centrifugally driven or simply magnetic winds of rapidly-rotating, strongly-magnetized T Tauri stars in causing the inward or outward migration of close-in giant planets. The azimuthal ram pressure of the magnetized wind acting on the planet tends to increase the planet's angular momentum and cause outward migration if the star's rotation period P∗P_* is less than the planet's orbital period PpP_p. In the opposite case, P∗>PpP_* > P_p, the planet migrates inward. Thus, planets orbiting at distances larger (smaller) than 0.06AU(P∗/5d)2/30.06 {\rm AU}(P_*/5{\rm d})^{2/3} tend to be pushed outward (inward), where P∗P_* is the rotation period of the star assumed to have the mass of the sun. The magnetic winds are likely to occur in T Tauri stars where the thermal speed of the gas close to the star is small, where the star's magnetic field is strong, and where the star rotates rapidly. The time-scale for appreciable radial motion of the planet is estimated as ∌2−20\sim 2 - 20 Myr. A sufficiently massive close-in planet may cause tidal locking and once this happens the radial migration due to the magnetic wind ceases. The magnetic winds are expected to be important for planet migration for the case of a multipolar magnetic field rather than a dipole field where the wind is directed away from the equatorial plane and where a magnetospheric cavity forms. The influence of the magnetic wind in eroding and eventually destroying the accretion disk is analyzed. A momentum integral is derived for the turbulent wind/disk boundary layer and this is used to estimate the disk erosion time-scale as ∌1−102\sim 1-10^2 Myr, with the lower value favored.Comment: 8 pages, 6 figure

    Phenological changes in the Southern Hemisphere

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    Current evidence of phenological responses to recent climate change is substantially biased towards northern hemisphere temperate regions. Given regional differences in climate change, shifts in phenology will not be uniform across the globe, and conclusions drawn from temperate systems in the northern hemisphere might not be applicable to other regions on the planet. We conduct the largest meta-analysis to date of phenological drivers and trends among southern hemisphere species, assessing 1208 long-term datasets from 89 studies on 347 species. Data were mostly from Australasia (Australia and New Zealand), South America and the Antarctic/subantarctic, and focused primarily on plants and birds. This meta-analysis shows an advance in the timing of spring events (with a strong Australian data bias), although substantial differences in trends were apparent among taxonomic groups and regions. When only statistically significant trends were considered, 82% of terrestrial datasets and 42% of marine datasets demonstrated an advance in phenology. Temperature was most frequently identified as the primary driver of phenological changes; however, in many studies it was the only climate variable considered. When precipitation was examined, it often played a key role but, in contrast with temperature, the direction of phenological shifts in response to precipitation variation was difficult to predict a priori . We discuss how phenological information can inform the adaptive capacity of species, their resilience, and constraints on autonomous adaptation. We also highlight serious weaknesses in past and current data collection and analyses at large regional scales (with very few studies in the tropics or from Africa) and dramatic taxonomic biases. If accurate predictions regarding the general effects of climate change on the biology of organisms are to be made, data collection policies focussing on targeting data-deficient regions and taxa need to be financially and logistically supported

    Local Sensing of Absolute Refractive Index During Protein-Binding using Microlasers with Spectral Encoding

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    Multiplexed, specific, and sensitive detection of antigens is critical for the rapid and accurate diagnosis of disease and the informed development of personalized treatment plans. Here, it is shown that polymer microsphere lasers can be used as photonic sensors to monitor and quantify direct surface binding of biomolecules via changes in the refractive index. The unique spectral signature of each individual laser can be used to find their size and effective refractive index which adds a new encoding dimension when compared to conventional fluorescent beads. Antibody-functionalized microlasers selectively detect protein binding, as demonstrated for Immunoglobulin G and C-reactive protein, and have the ability to resolve different stages of the multilayer surface modification. Moreover, by continuously monitoring single lasers, the possibility of real-time monitoring of binding dynamics between antigens in solution phase and the immobilized antibodies is demonstrated. For multiplexed detection, the microlasers are employed in a flow cytometer configuration, with fast spectral detection and identification of microlasers with and without antigen binding. It is envisioned that by combining microlasers with well-established surface modification chemistries and flow geometries, the multiplexing ability of microbead immunoassays can be strongly increased while also opening avenues for single-cell profiling within heterogeneous cell populations

    Sticky Stories: Joe Orton, Queer History, Queer Dramaturgy

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    This paper investigates the resonances of Orton’s work for contemporary queer audiences. By presenting potential reasons for the rise and fall in popularity and visibility of Orton’s work for queer and gay audiences through the 1980s and 1990s, this paper looks to the queer context in which Joe Orton’s work developed in order to explore the queer social history into which it fits.  This sense of queer history is linked to contemporary notions of queer theorising about temporalities and queer dramaturgy, which offers potentially novel ways of engaging with Orton’s work queerly without twisting it to fit a ‘neat’ reading, in part because such readings tend to ‘smooth out’ the more difficult elements of the work.  In particular, the paper explores the theatrical form of farce, often articulated as conservative, in relation to queer positions, which are quite the opposite.  In so doing, the paper, by way of queer temporalities and work on queer dramaturgies, sketches out a reading strategy that does not ignore Orton’s more difficult or stickier elements, in particular his treatment of women and race

    Does size matter for horny beetles? A geometric morphometric analysis of interspecific and intersexual size and shape variation in Colophon haughtoni Barnard, 1929, and C. kawaii Mizukami, 1997 (Coleoptera: Lucanidae)

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    Colophon is an understudied, rare and endangered stag beetle genus with all species endemic to isolated mountain peaks in South Africa’s Western Cape. Geometric morphometrics was used to analyse intersexual and interspecific variation of size and shape in the mandibles, heads, pronota and elytra of two sympatric species: Colophon haughtoni and Colophon kawaii. All measured structures showed significant sexual dimorphism, which may result from male-male competition for females. Female mandibles were too small and featureless for analysis, but male Colophon beetles possess large, ornate mandibles for fighting. Males had significantly larger heads and pronota that demonstrated shape changes which may relate to resource diversion to the mandibles and their supporting structures. Females are indistinguishable across species, but males were accurately identified using mandibles, heads and pronota. Male C. kawaii were significantly larger than C. haughtoni for all structures. These results support the species status of C. kawaii, which is currently in doubt due to its hybridisation with C. haughtoni. We also demonstrate the value of geometric morphometrics as a tool which may aid Colophon conservation by providing biological and phylogenetic insights and enabling species identification
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