5,744 research outputs found

    Charge shelving and bias spectroscopy for the readout of a charge-qubit on the basis of superposition states

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    Charge-based qubits have been proposed as fundamental elements for quantum computers. One commonly proposed readout device is the single-electron transistor (SET). SETs can distinguish between localized charge states, but lack the sensitivity to directly distinguish superposition states, which have greatly enhanced coherence times compared with position states. We propose introducing a third dot, and exploiting energy dependent tunnelling from the qubit into this dot (bias spectroscopy) for pseudo-spin to charge conversion and superposition basis readout. We introduce an adiabatic fast passage-style charge pumping technique which enables efficient and robust readout via charge shelving, avoiding problems due to finite SET measurement time.Comment: 4 pages, 3 figures, note slightly changed title, replaced with journal versio

    Tentative Evidence for Relativistic Electrons Generated by the Jet of the Young Sun-like Star DG Tau

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    Synchrotron emission has recently been detected in the jet of a massive protostar, providing further evidence that certain jet formation characteristics for young stars are similar to those found for highly relativistic jets from AGN. We present data at 325 and 610 MHz taken with the GMRT of the young, low-mass star DG Tau, an analog of the Sun soon after its birth. This is the first investigation of a low-mass YSO at at such low frequencies. We detect emission with a synchrotron spectral index in the proximity of the DG Tau jet and interpret this emission as a prominent bow shock associated with this outflow. This result provides tentative evidence for the acceleration of particles to relativistic energies due to the shock impact of this otherwise very low-power jet against the ambient medium. We calculate the equipartition magnetic field strength (0.11 mG) and particle energy (4x10^40 erg), which are the minimum requirements to account for the synchrotron emission of the DG Tau bow shock. These results suggest the possibility of low energy cosmic rays being generated by young Sun-like stars.Comment: 19 pages, 2 figures, accepted for publication in ApJ Letter

    Creative writing in A level English literature

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    This is an Author's Accepted Manuscript of an article published in New Writing: The International Journal for the Practice and Theory of Creative Writing, 6(3), 187 - 195, 2009, copyright Taylor & Francis, available online at: http://www.tandfonline.com/10.1080/14790720903556155.This is a time of change and real development for creative writing at A level. Whilst it has been an important part of English Language and English Language & Literature A level specifications for some time, its presence within English Literature has been marginal, and is an option that has rarely been adopted by teachers of the subject. Recent changes to English Literature specifications, however, mean that creative writing (along with recreative and transformative writing) now exists in a much more formalised way on all A level English Literature specifications. As the largest of the three A level Englishes, this is a significant development. The advent of creative writing in English Literature makes this an important issue in teachers' Continuing Professional Development (Green, 2008) and raises important questions for the teaching body in schools and lecturers in further education. What is the role of creative writing in teaching literature? How do creative and analytical writing relate to each other? What is the relationship between creative writing and reading? This paper offers an initial response to these and other issues, and suggests some of the ways in which creative writing can be used both in its own right and to enhance the study of English Literature at A level

    Creative writing in A level English literature

    Get PDF
    This is an Author's Accepted Manuscript of an article published in New Writing: The International Journal for the Practice and Theory of Creative Writing, 6(3), 187 - 195, 2009, copyright Taylor & Francis, available online at: http://www.tandfonline.com/10.1080/14790720903556155.This is a time of change and real development for creative writing at A level. Whilst it has been an important part of English Language and English Language & Literature A level specifications for some time, its presence within English Literature has been marginal, and is an option that has rarely been adopted by teachers of the subject. Recent changes to English Literature specifications, however, mean that creative writing (along with recreative and transformative writing) now exists in a much more formalised way on all A level English Literature specifications. As the largest of the three A level Englishes, this is a significant development. The advent of creative writing in English Literature makes this an important issue in teachers' Continuing Professional Development (Green, 2008) and raises important questions for the teaching body in schools and lecturers in further education. What is the role of creative writing in teaching literature? How do creative and analytical writing relate to each other? What is the relationship between creative writing and reading? This paper offers an initial response to these and other issues, and suggests some of the ways in which creative writing can be used both in its own right and to enhance the study of English Literature at A level

    Demography of male reproductive queues in cooperatively breeding superb fairy-wrens Malurus cyaneus

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    1. Subordinate helpers in cooperative societies may gain both immediate and future benefits, including paternity and territorial inheritance. However, if such opportunities correlate with rank in the queue, it is unclear why such queues should be stable

    Differential pathways to adult metabolic dysfunction following poor nutrition at two critical developmental periods in sheep

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    Epidemiological and experimental studies suggest early nutrition has long-term effects on susceptibility to obesity, cardiovascular and metabolic diseases. Small and large animal models confirm the influence of different windows of sensitivity, from fetal to early postnatal life, on offspring phenotype. We showed previously that undernutrition in sheep either during the first month of gestation or immediately after weaning induces differential, sex-specific changes in adult metabolic and cardiovascular systems. The current study aims to determine metabolic and molecular changes that underlie differences in lipid and glucose metabolism induced by undernutrition during specific developmental periods in male and female sheep. Ewes received 100% (C) or 50% nutritional requirements (U) from 1–31 days gestation, and 100% thereafter. From weaning (12 weeks) to 25 weeks, offspring were then fed either ad libitum (CC, UC) or were undernourished (CU, UU) to reduce body weight to 85% of their individual target. From 25 weeks, all offspring were fed ad libitum. A cohort of late gestation fetuses were studied after receiving either 40% nutritional requirements (1–31 days gestation) or 50% nutritional requirements (104–127 days gestation). Post-weaning undernutrition increased in vivo insulin sensitivity, insulin receptor and glucose transporter 4 expression in muscle, and lowered hepatic methylation at the delta-like homolog 1/maternally expressed gene 3 imprinted cluster in adult females, but not males. Early gestational undernutrition induced lower hepatic expression of gluconeogenic factors in fetuses and reduced in vivo adipose tissue insulin sensitivity in adulthood. In males, undernutrition in early gestation increased adipose tissue lipid handling mechanisms (lipoprotein lipase, glucocorticoid receptor expression) and hepatic methylation within the imprinted control region of insulin-like growth factor 2 receptor in adulthood. Therefore, undernutrition during development induces changes in mechanisms of lipid and glucose metabolism which differ between tissues and sexes dependent on the period of nutritional restriction. Such changes may increase later life obesity and dyslipidaemia risk

    Accurate OH maser positions II. the Galactic Center region

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    We present high spatial resolution observations of ground-state OH masers, achieved using the Australia Telescope Compact Array (ATCA). These observations were conducted towards 171 pointing centres, where OH maser candidates were identified previously in the Southern Parkes Large-Area Survey in Hydroxyl (SPLASH) towards the Galactic Center region, between Galactic longitudes of 355355^{\circ} and 55^{\circ} and Galactic latitudes of 2-2^{\circ} and +2+2^{\circ}. We detect maser emission towards 162 target fields and suggest that 6 out of 9 non-detections are due to intrinsic variability. Due to the superior spatial resolution of the follow-up ATCA observations, we have identified 356 OH maser sites in the 162 of the target fields with maser detections. Almost half (161 of 356) of these maser sites have been detected for the first time in these observations. After comparing the positions of these 356 maser sites to the literature, we find that 269 (76\%) sites are associated with evolved stars (two of which are planetary nebulae), 31 (9\%) are associated with star formation, four are associated with supernova remnants and we were unable to determine the origin of the remaining 52 (15\%) sites. Unlike the pilot region (\citealt{Qie2016a}), the infrared colors of evolved star sites with symmetric maser profiles in the 1612 MHz transition do not show obvious differences compared with those of evolved star sites with asymmetric maser profiles.Comment: 24 pages, 12 figures, accepted by ApJ

    Mapping cellular processes in the mesenchyme during palatal development in the absence of Tbx1 reveals complex proliferation changes and perturbed cell packing and polarity

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    The 22q11 deletion syndromes represent a spectrum of overlapping conditions including cardiac defects and craniofacial malformations. Amongst the craniofacial anomalies that are seen, cleft of the secondary palate is a common feature. Haploinsufficiency of TBX1 is believed to be a major contributor toward many of the developmental structural anomalies that occur in these syndromes, and targeted deletion of Tbx1 in the mouse reproduces many of these malformations, including cleft palate. However, the cellular basis of this defect is only poorly understood. Here, palatal development in the absence of Tbx1 has been analysed, focusing on cellular properties within the whole mesenchymal volume of the palatal shelves. Novel image analyses and data presentation tools were applied to quantify cell proliferation rates, including regions of elevated as well as reduced proliferation, and cell packing in the mesenchyme. Also, cell orientations (nucleus–Golgi axis) were mapped as a potential marker of directional cell movement. Proliferation differed only subtly between wild‐type and mutant until embryonic day (E)15.5 when proliferation in the mutant was significantly lower. Tbx1 (−/−) palatal shelves had slightly different cell packing than wild‐type, somewhat lower before elevation and higher at E15.5 when the wild‐type palate has elevated and fused. Cell orientation is biased towards the shelf distal edge in the mid‐palate of wild‐type embryos but is essentially random in the Tbx1 (−/−) mutant shelves, suggesting that polarised processes such as directed cell rearrangement might be causal for the cleft phenotype. The implications of these findings in the context of further understanding Tbx1 function during palatogenesis and of these methods for the more general analysis of genotype–phenotype functional relationships are discussed
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