801 research outputs found

    Views of Coaching Practice Expressed by School-Based Coaches

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    This study reports on the views of coaching expressed by school-based coaches and coaching experts in response to observing the practice of a novice coach featured in a video. Researchers hypothesized that a coach participant\u27s observations about another coach\u27s practice would be a useful tool for examining participants\u27 beliefs about coaching. Researchers compared responses from school-based coaches to the responses of coaching experts and views expressed in leading coaching literature in order to examine the variation in school-based coaches\u27 views. Analysis of responses from both practicing coaches and coaching experts revealed eight themes that describe components of the videotaped coaching cycle: 1) coaching relationships; 2) the use of praise by the coach; 3) discussions of student learning; 4) how coaches respond to teachers\u27 questions; 5) how coaches prompt reflection; 6) how coaches address teacher knowledge and learning; 7) discussions of mathematics content; and, 8) facilitation of the coaching session. The analysis also revealed that these themes correspond to accepted domains of coaching knowledge reported in the coaching literature

    q-Analogue of Am1An1Amn1A_{m-1}\oplus A_{n-1}\subset A_{mn-1}

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    A natural embedding Am1An1Amn1A_{m-1}\oplus A_{n-1}\subset A_{mn-1} for the corresponding quantum algebras is constructed through the appropriate comultiplication on the generators of each of the Am1A_{m-1} and An1A_{n-1} algebras. The above embedding is proved in their qq-boson realization by means of the isomorphism between the Aq\mathcal{A}_q^{-} (mn)nAq\sim {\otimes} ^n \mathcal{A}_q^{-}(m)mAq\sim {\otimes}^m\mathcal{A}_q^{-}(n) algebras.Comment: 11 pages, no figures. In memory of professor R. P. Rousse

    Fermionic Coset, Critical Level W^(2)_4-Algebra and Higher Spins

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    The fermionic coset is a limit of the pure spinor formulation of the AdS5xS5 sigma model as well as a limit of a nonlinear topological A-model, introduced by Berkovits. We study the latter, especially its symmetries, and map them to higher spin algebras. We show the following. The linear A-model possesses affine \AKMSA{pgl}{4}{4}_0 symmetry at critical level and its \AKMSA{psl}{4}{4}_0 current-current perturbation is the nonlinear model. We find that the perturbation preserves W4(2)\mathcal{W}^{(2)}_4-algebra symmetry at critical level. There is a topological algebra associated to \AKMSA{pgl}{4}{4}_0 with the properties that the perturbation is BRST-exact. Further, the BRST-cohomology contains world-sheet supersymmetric symplectic fermions and the non-trivial generators of the W4(2)\mathcal{W}^{(2)}_4-algebra. The Zhu functor maps the linear model to a higher spin theory. We analyze its \SLSA{psl}{4}{4} action and find finite dimensional short multiplets.Comment: 25 page

    Supersymmetry Flows, Semi-Symmetric Space Sine-Gordon Models And The Pohlmeyer Reduction

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    We study the extended supersymmetric integrable hierarchy underlying the Pohlmeyer reduction of superstring sigma models on semi-symmetric superspaces F/G. This integrable hierarchy is constructed by coupling two copies of the homogeneous integrable hierarchy associated to the loop Lie superalgebra extension f of the Lie superalgebra f of F and this is done by means of the algebraic dressing technique and a Riemann-Hilbert factorization problem. By using the Drinfeld-Sokolov procedure we construct explicitly, a set of 2D spin \pm1/2 conserved supercharges generating supersymmetry flows in the phase space of the reduced model. We introduce the bi-Hamiltonian structure of the extended homogeneous hierarchy and show that the two brackets are of the Kostant-Kirillov type on the co-adjoint orbits defined by the light-cone Lax operators L_\pm. By using the second symplectic structure, we show that these supersymmetries are Hamiltonian flows, we compute part of the supercharge algebra and find the supersymmetric field variations they induce. We also show that this second Poisson structure coincides with the canonical Lorentz-Invariant symplectic structure of the WZNW model involved in the Lagrangian formulation of the extended integrable hierarchy, namely, the semi-symmetric space sine-Gordon model (SSSSG), which is the Pohlmeyer reduced action functional for the transverse degrees of freedom of superstring sigma models on the cosets F/G. We work out in some detail the Pohlmeyer reduction of the AdS_2xS^2 and the AdS_3xS^3 superstrings and show that the new conserved supercharges can be related to the supercharges extracted from 2D superspace. In particular, for the AdS_2xS^2 example, they are formally the same.Comment: V2: Two references added, V3: Modifications in section 2.6, V4: Published versio

    Inflammation-based scores do not predict post-transplant recurrence of hepatocellular carcinoma (HCC) in patients within Milan criteria.

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    Background: Increased preoperative inflammation scores, such as neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR) and inflammation-based index (IBI) have been related to post-transplant HCC recurrence. We evaluated the association between inflammation-based scores (NLR, PLR, IBI) and post-LT HCC recurrence as well as tumour necrosis after transarterial embolisation. Methods: 150 consecutive patients that were transplanted for HCC within the Milan criteria between 1996-2010 were included; data regarding inflammatory markers, patient and tumour characteristics were analyzed. Results: NLR, PLR and IBI were not significantly associated with post-LT HCC recurrence or worse overall survival. Increased NLR and PLR were associated with complete tumour necrosis in the subset of patients that received preoperative transarterial embolization (P<0.05). Cox regression analysis revealed that absence of neo-adjuvant transarterial therapy (OR=4.33, 95%CI 1.28-14.64; P=0.02) and no fulfilment of the Milan criteria in the explanted liver (OR=3.34, 95%CI 1.08-10.35; P=0.04) were independently associated with post-LT HCC recurrence. Conclusion: Inflammation-based scores did not predict HCC recurrence post-LT in our group of patients. NLR and PLR were associated with better response to TAE, as this was recorded histologically in the explanted liver. Histological fulfilment of the Milan criteria and absence of neo-adjuvant transarterial treatment were significantly associated with post-LT HCC recurrence. Liver Transpl , 2014. © 2014 AASLD

    Heterogenized Pyridine-Substituted Cobalt(II) Phthalocyanine Yields Reduction of CO2 by Tuning the Electron Affinity of the Co Center

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    Conversion of CO2 to reduced products is a promising route to alleviate irreversible climate change. Here we report the synthesis of a Co-based phthalocyanine with pyridine moieties (CoPc-Pyr), which is supported on a carbon electrode and shows Faradaic efficiency ∼90% for CO at 490 mV of overpotential (-0.6 V vs reversible hydrogen electrode (RHE)). In addition, its catalytic activity at -0.7 V versus RHE surpasses other Co-based molecular and metal-organic framework catalysts for CO2 reduction at this bias. Density functional theory calculations show that pyridine moieties enhance CO2 adsorption and electron affinity of the Co center by an inductive effect, thus lowering the overpotential necessary for CO2 conversion. Our study shows that CoPc-Pyr reduces CO2 at lower overpotential and with higher activity than noble metal electrodes, such as silver

    Regular Conjugacy Classes in the Weyl Group and Integrable Hierarchies

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    Generalized KdV hierarchies associated by Drinfeld-Sokolov reduction to grade one regular semisimple elements from non-equivalent Heisenberg subalgebras of a loop algebra \G\otimes{\bf C}[\lambda,\lambda^{-1}] are studied. The graded Heisenberg subalgebras containing such elements are labelled by the regular conjugacy classes in the Weyl group {\bf W}(\G) of the simple Lie algebra \G. A representative w\in {\bf W}(\G) of a regular conjugacy class can be lifted to an inner automorphism of \G given by w^=exp(2iπadI0/m)\hat w=\exp\left(2i\pi {\rm ad I_0}/m\right), where I0I_0 is the defining vector of an sl2sl_2 subalgebra of \G.The grading is then defined by the operator dm,I0=mλddλ+adI0d_{m,I_0}=m\lambda {d\over d\lambda} + {\rm ad} I_0 and any grade one regular element Λ\Lambda from the Heisenberg subalgebra associated to [w][w] takes the form Λ=(C++λC)\Lambda = (C_+ +\lambda C_-), where [I0,C]=(m1)C[I_0, C_-]=-(m-1) C_- and C+C_+ is included in an sl2sl_2 subalgebra containing I0I_0. The largest eigenvalue of adI0{\rm ad}I_0 is (m1)(m-1) except for some cases in F4F_4, E6,7,8E_{6,7,8}. We explain how these Lie algebraic results follow from known results and apply them to construct integrable systems.If the largest adI0{\rm ad} I_0 eigenvalue is (m1)(m-1), then using any grade one regular element from the Heisenberg subalgebra associated to [w][w] we can construct a KdV system possessing the standard \W-algebra defined by I0I_0 as its second Poisson bracket algebra. For \G a classical Lie algebra, we derive pseudo-differential Lax operators for those non-principal KdV systems that can be obtained as discrete reductions of KdV systems related to glngl_n. Non-abelian Toda systems are also considered.Comment: 44 pages, ENSLAPP-L-493/94, substantial revision, SWAT-95-77. (use OLATEX (preferred) or LATEX

    Can support workers from AgeUK deliver an intervention to support older people with anxiety and depression? A qualitative evaluation.

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    BACKGROUND: Anxiety and depression often co-exist. These disorders are under-diagnosed and under-treated, specifically among older people, and lead to increased use of health and social care services and raised mortality. Older people report a reluctance to present to their GP with depression or anxiety symptoms due to perceived stigma about mental health problems, lack of acceptable treatments and the prioritising of physical health problems. Third sector organisations, who work closely with older people in the community, are well-placed to provide additional support. We developed a brief intervention based on principles of Behavioural Activation, with encouragement to participate in a group activity, for delivery by Support Workers from AgeUK. The aim of the study was to examine whether this brief intervention could be delivered to older people with anxiety and/or depression, with sufficient fidelity, and whether this approach was acceptable to patients, GPs and AgeUK Support Workers. METHODS: Semi-structured interviews with older people with self-reported anxiety and/or depression (who received the intervention), Support Workers and GPs to assess acceptability of the intervention and impact on routine care. A constant comparative approach was used to analyse the data. Intervention sessions between Support Workers and older people were digitally recorded and reviewed by the research team to assess fidelity. RESULTS: The Support Workers delivered the intervention with fidelity; access to the training maual and ongoing supervision were important. Older people found the intervention acceptable and valued the one-to-one support they received; group activities suggested by Support Workers were not valued by all. GPs recognised the need for additional support for vulnerable older people, but acknowledged they could not provide this support. Participation in the study did not impact on GP routine care, other than responding to the calls from the study team about risk of self-harm. CONCLUSIONS: Support Workers within AgeUK, can be recruited and trained to deliver an intervention, based on the principles of Behavioural Activation, to older people with anxiety and/or depression. The training and supervision model used in the study was acceptable to Support Workers, and the intervention was acceptable to older people and GPs. This model has the potential to contribute to improving the support and care of older people in primary care with anxiety and depression. Further testing is required in a full trial. TRIAL REGISTRATION: Trial registration number ISRCTN16318986 . Registered 10/11/2016

    Between the Natural and the Artificial: The Sublime Sexual Sensation of Car Crashes in J.G. Ballard’s Crash

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    At a time when technology progressively pushes back nature, the sexual act runs the risk of being denaturalised. The notion of the sublime, which I argue is how humans react to the machine as a surrogate for nature and as a sexual stimulus in Crash (1973), is therefore of central interest in this article. Ballard himself has described Crash as ‘the first pornographic novel based on technology’ (1973, 6). This engagement with a technologised sexuality is explored as a subjective narrative stance, which grants authenticity to the fictive alter ego, who can probe alternatives to an extra-textual reality. This narrative mode is notably potent in relation to the narrator’s estimation of the merge between sexuality and technology in the form of car crashes uniting Eros and Thanatos. I therefore suggest that Crash can be read as an attempt to localise the natural and human in a world dictated by artificiality and technology
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