1,108 research outputs found

    An Evaluation of Social Stars, Regulars, Neglectees, and Isolates in Ability-Grouped and Random-Grouped Classrooms

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    Education in the United States attempts to present maximum opportunities for learning in a democratic atmosphere. Many great educators have sought means to accomplish this end. Today, because of the stimulating force of other nations, even greater pressure is being brought to bear to achieve these goals. The plan of grouping pupils according to their abilities has been presented as one way to facilitate learning. Ability grouping is the assigning of pupils who are essentially alike to special grade levels and to parallel sections of the same grade. Although it may be thought that ability grouping is a new procedure, as early as 1920 the Detroit schools divided ten thousand students entering the first grade into three groups, on the basis of group intelligence tests. A letter classification of X, Y, or Z was given to each group. Group X was composed of the highest 20 per cent of the new enrollment; Group Y, of the middle 60 per cent; and Group Z, of the lower 20 per cent of the pupils. From the first recorded use of ability grouping, different methods of grouping have been used, with varying degrees of success. In the United States, during 1947-48, over half of the 1,598 city school systems were using ability grouping in some form or another in at least one of their schools. The percentage of cities using ability grouping ranged from 72 per cent in cities of more than 100,000 population, to 44 per cent in cities of 2,500 to 5,000 population. Typical of problems arising in ability grouping are: the relationship of ability grouping to achievement, the relationship of ability grouping to attitudes, the relationship of ability grouping to emotions, and the relationship of ability grouping to social acceptance. The purpose of this thesis is an evaluation of problems arising in ability grouping in relation to social acceptance, or sociometrics

    Generation of spin-motion entanglement in a trapped ion using long-wavelength radiation

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    Applying a magnetic-field gradient to a trapped ion allows long-wavelength radiation to produce a mechanical force on the ion's motion when internal transitions are driven. We demonstrate such a coupling using a single trapped Yb+171 ion and use it to produce entanglement between the spin and motional state, an essential step toward using such a field gradient to implement multiqubit operations

    Ground-state cooling of a trapped ion Using long-wavelength radiation

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    We demonstrate ground-state cooling of a trapped ion using radio-frequency (rf) radiation. This is a powerful tool for the implementation of quantum operations, where rf or microwave radiation instead of lasers is used for motional quantum state engineering. We measure a mean phonon number of n¯=0.13(4) after sideband cooling, corresponding to a ground-state occupation probability of 88(7)%. After preparing in the vibrational ground state, we demonstrate motional state engineering by driving Rabi oscillations between the |n=0⟩ and |n=1⟩ Fock states. We also use the ability to ground-state cool to accurately measure the motional heating rate and report a reduction by almost 2 orders of magnitude compared with our previously measured result, which we attribute to carefully eliminating sources of electrical noise in the system

    Progress report : 1996 / Cattle Industry Compensation Act Research Advisory Committee.

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    The Cattle Industry Compensation Fund was established under the Cattle Industry Compensation Aet 1965. Monies received on cattle sales by the Commissioner for State Taxation are paid into the Fund and matched by State Government appropriation. Funds are held to compensate producers for losses incurred in disease eradication programs, to promote and encourage scientific research for improvement of cattle health and promotion and for purposes that, in the opinion of the Minister, will promote and encourage the cattle industry An Advisory Committee, established by the Hon. Minister for Primary Industry makes recommendations for funding on a project basis. The Advisory Committee published progress reports in 1984 and 1989. This report covers the period 1990 to 1995

    Efficient preparation and detection of microwave dressed-state qubits and qutrits with trapped ions

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    We demonstrate a method for preparing and detecting all eigenstates of a three-level microwave dressed system with a single trapped ion. The method significantly reduces the experimental complexity of gate operations with dressed-state qubits, as well as allowing all three of the dressed states to be prepared and detected, thereby providing access to a qutrit that is well protected from magnetic field noise. In addition, we demonstrate individual addressing of the clock transitions in two ions using a strong static magnetic field gradient, showing that our method can be used to prepare and detect microwave dressed states in a string of ions when performing multi-ion quantum operations with microwave and radio frequency fields. The individual addressability of clock transitions could also allow for the control of pairwise interaction strengths between arbitrary ions in a string using lasers

    An automated approach to identify scientific publications reporting pharmacokinetic parameters [version 1; peer review: awaiting peer review]

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    Pharmacokinetic (PK) predictions of new chemical entities are aided by prior knowledge from other compounds. The development of robust algorithms that improve preclinical and clinical phases of drug development remains constrained by the need to search, curate and standardise PK information across the constantly-growing scientific literature. The lack of centralised, up-to-date and comprehensive repositories of PK data represents a significant limitation in the drug development pipeline.In this work, we propose a machine learning approach to automatically identify and characterise scientific publications reporting PK parameters from in vivo data, providing a centralised repository of PK literature. A dataset of 4,792 PubMed publications was labelled by field experts depending on whether in vivo PK parameters were estimated in the study. Different classification pipelines were compared using a bootstrap approach and the best-performing architecture was used to develop a comprehensive and automatically-updated repository of PK publications. The best-performing architecture encoded documents using unigram features and mean pooling of BioBERT embeddings obtaining an F1 score of 83.8% on the test set. The pipeline retrieved over 121K PubMed publications in which in vivo PK parameters were estimated and it was scheduled to perform weekly updates on newly published articles. All the relevant documents were released through a publicly available web interface (https://app.pkpdai.com) and characterised by the drugs, species and conditions mentioned in the abstract, to facilitate the subsequent search of relevant PK data. This automated, open-access repository can be used to accelerate the search and comparison of PK results, curate ADME datasets, and facilitate subsequent text mining tasks in the PK domain.</ns4:p

    Electronic structures of free-standing nanowires made from indirect bandgap semiconductor gallium phosphide

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    We present a theoretical study of the electronic structures of freestanding nanowires made from gallium phosphide (GaP)--a III-V semiconductor with an indirect bulk bandgap. We consider [001]-oriented GaP nanowires with square and rectangular cross sections, and [111]-oriented GaP nanowires with hexagonal cross sections. Based on tight binding models, both the band structures and wave functions of the nanowires are calculated. For the [001]-oriented GaP nanowires, the bands show anti-crossing structures, while the bands of the [111]-oriented nanowires display crossing structures. Two minima are observed in the conduction bands, while the maximum of the valence bands is always at the Γ\Gamma-point. Using double group theory, we analyze the symmetry properties of the lowest conduction band states and highest valence band states of GaP nanowires with different sizes and directions. The band state wave functions of the lowest conduction bands and the highest valence bands of the nanowires are evaluated by spatial probability distributions. For practical use, we fit the confinement energies of the electrons and holes in the nanowires to obtain an empirical formula.Comment: 19 pages, 10 figure

    The contested and contingent outcomes of Thatcherism in the UK

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    The death of Margaret Thatcher in April 2013 sparked a range of discussions and debates about the significance of her period in office and the political project to which she gave her name: Thatcherism. This article argues that Thatcherism is best understood as a symbolically important part of the emergence of first-phase neoliberalism. It engages with contemporary debates about Thatcherism among Marxist commentators and suggests that several apparently divergent positions can help us now reach a more useful analysis of Thatcherism’s short- and long-term outcomes for British political economy. The outcomes identified include: an initial crisis in the neoliberal project in the UK; the transformation of the party political system to be reflective of the politics of neoliberalism, rather than its contestation; long-term attempts at the inculcation of the neoliberal individual; de-industrialisation and financial sector dependence; and a fractured and partially unconscious working class. In all long-term outcomes, the contribution of Thatcherism is best understood as partial and largely negative, in that it cleared the way for a longer-term and more constructive attempt to embed neoliberal political economy. The paper concludes by suggesting that this analysis can inform current debates on the left of British politics about how to oppose and challenge the imposition of neoliberal discipline today

    DMPP-4: Candidate sub-Neptune mass planets orbiting a naked-eye star

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    We present radial velocity measurements of the very bright (V5.7V\sim5.7) nearby F star, DMPP-4 (HD 184960). The anomalously low Ca II H&K emission suggests mass loss from planets orbiting a low activity host star. Periodic radial velocity variability with 10\sim 10 ms1^{-1} amplitude is found to persist over a >4>4 year timescale. Although the non-simultaneous photometric variability in four TESS sectors supports the view of an inactive star, we identify periodic photometric signals and also find spectroscopic evidence for stellar activity. We used a posterior sampling algorithm that includes the number of Keplerian signals, NpN_\textrm{p}, as a free parameter to test and compare (1) purely Keplerian models (2) a Keplerian model with linear activity correlation and (3) Keplerian models with Gaussian processes. A preferred model, with one Keplerian and quasi-periodic Gaussian process indicates a planet with a period of Pb=3.49820.0027+0.0015P_\textrm{b} = 3.4982^{+0.0015}_{-0.0027} d and corresponding minimum mass of mbsini=12.21.9+1.8m_\textrm{b}\,\textrm{sin}\,i = 12.2^{+1.8}_{-1.9} M_\oplus. Without further high time resolution observations over a longer timescale, we cannot definitively rule out the purely Keplerian model with 2 candidates planets with Pb=2.45700.0462+0.0026P_\textrm{b} = 2.4570^{+0.0026}_{-0.0462} d, minimum mass mbsini=8.01.5+1.1m_\textrm{b}\,\textrm{sin}\,i = 8.0^{+1.1}_{-1.5} M_\oplus and Pc=5.41960.0030+0.6766P_\textrm{c} = 5.4196^{+0.6766}_{-0.0030} d and corresponding minimum mass of mbsini=12.21.6+1.4m_\textrm{b}\,\textrm{sin}\,i = 12.2^{+1.4}_{-1.6} M_\oplus. The candidate planets lie in the region below the lower-envelope of the Neptune Desert. Continued mass loss may originate from the highly irradiated planets or from an as yet undetected body in the system.Comment: 19 pages, 11 figures. Accepted for publication in MNRA
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