1,788 research outputs found

    Spectral Analysis of a Four Mode Cluster State

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    We theoretically evaluate the squeezed joint operators produced in a single optical parametric oscillator which generates quadripartite entangled outputs, as demonstrated experimentally by Pysher et al. \cite{pysher}[Phys. Rev. Lett. 107, 030505 (2011)]. Using a linearized fluctuation analysis we calculate the squeezing of the joint quadrature operators below threshold for a range of local oscillator phases and frequencies. These results add to the existing theoretical understanding of this potentially important system.Comment: 4 pages, 6 figure

    A systematic review of shared decision making interventions in child and youth mental health: synthesising the use of theory, intervention functions, and behaviour change techniques

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    Reviews around interventions to improve shared decision making (SDM) for child and youth mental health have produced inconclusive findings on what approaches increase participation. Importantly, the previous reviews did not explore the use of theory, as well as mechanisms of change (intervention functions) and active units of change (behaviour change techniques). The aim of this review was to explore these factors and ascertain how, if at all, these contribute to SDM. Five databases were searched up until April 2020. Studies met inclusion criteria if they were: (a) an intervention to facilitate SDM; (b) aimed at children, adolescence, or young people aged up to 25, with a mental health difficulty, or their parents/guardians; and (c) included a control group. Data were extracted on patient characteristics, study design, intervention, theoretical background, intervention functions, behaviour change techniques, and SDM. Quality assessment of the studies was undertaken using the Effective Public Health Practice Project (EPHPP) quality assessment tool. Eight different interventions met inclusion criteria. The role of theory to increase SDM remains unclear. Specific intervention functions, such as 'education' on SDM and treatment options and 'environmental restructuring' using decision aids, are being used in SDM interventions, as well as 'training' for clinicians. Similarly, behaviour change techniques linked to these, such as 'adding objects to the environment', 'discussing pros/cons', and clinicians engaging in 'behavioural practice/rehearsal'. However, as most studies scored low on the quality assessment criteria, as well as a small number of studies included and a low number of behaviour change techniques utilised, links between behaviour change techniques, intervention functions and increased participation remain tentative. Intervention developers and clinicians may wish to consider specific intervention functions and behaviour change techniques to facilitate SDM

    Analysis of a continuous-variable quadripartite cluster state from a single optical parametric oscillator

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    We examine the feasibility of generating continuous-variable multipartite entanglement in an intra-cavity quadruply concurrent downconversion scheme that has been proposed for the generation of cluster states by Menicucci \textit{et al.} [Physical Review Letters \textbf{101}, 130501 (2008)]. By calculating optimized versions of the van Loock-Furusawa correlations we demonstrate genuine quadripartite entanglement and investigate the degree of entanglement present. Above the oscillation threshold the basic cluster state geometry under consideration suffers from phase diffusion. We alleviate this problem by incorporating a small injected signal into our analysis. Finally, we investigate squeezed joint operators. While the squeezed joint operators approach zero in the undepleted regime, we find that this is not the case when we consider the full interaction Hamiltonian and the presence of a cavity. In fact, we find that the decay of these operators is minimal in a cavity, and even depletion alone inhibits cluster state formation.Comment: 26 pages, 12 figure

    Loss of expression of ATM is associated with worse prognosis in colorectal cancer and loss of Ku70 expression is associated with CIN

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    Repair of double strand DNA breaks (DSBs) is pivotal in maintaining normal cell division and disruption of this system has been shown to be a key factor in carcinogenesis. Loss of expression of the DSB repair proteins have previously been shown to be associated with poorer survival in colorectal cancer. We wished to ascertain the relationship of altered expression of the DSB repair proteins γ-H2AX (gamma-H2AX), ATM and Ku70 with biological and clinico-pathological features of colorectal cancer. 908 tumours from the VICTOR clinical trial of stage II/III colorectal cancer were analysed for expression of γ-H2AX, ATM and Ku70 using immunohistochemistry. Expression levels were correlated with CIN and with diseasefree survival, correcting for microsatellite instability, BRAF/KRAS mutation status, Dukes stage, chemo/radiotherapy, age, gender and tumour location. Down-regulated Ku70 expression was associated with chromosomal instability (p=0.029) in colorectal cancer. Reduced ATM expression was an independent marker of poor disease-free survival (HR=1.67, 95% CI 1.11-2.50, p=0.015). For Ku70, further studies are required to investigate the potential relationship of non-homologous end joining with chromosomal instability. Loss of ATM expression might serve as a biomarker of poor prognosis in colorectal cancer

    ‘Just like talking to someone about like shit in your life and stuff, and they help you’: hopes and expectations for therapy among depressed adolescents

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    Objective: To explore hopes and expectations for therapy among a clinical population of depressed adolescents. Method: As part of a randomised clinical trial, 77 adolescents aged 11 to 17, with moderate to severe depression, were interviewed using a semi-structured interview schedule. The interviews were analysed qualitatively, using Framework Analysis. Results: The findings are reported around five themes: “The difficulty of imagining what will happen in therapy”, "the 'talking cure'"; “the therapist as doctor”, “therapy as a relationship” and “regaining the old self or developing new capacities”. Conclusions: Differing expectations are likely to have implications for the way young people engage with treatment, and failure to identify these expectations may lead to a risk of treatment breakdown

    Identification of Non-unitary triplet pairing in a heavy Fermion superconductor UPt_3

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    A NMR experiment recently done by Tou et al. on a heavy Fermion superconductor UPt3_3 is interpreted in terms of a non-unitary spin-triplet pairing state which we have been advocating. The proposed state successfully explains various aspects of the seemingly complicated Knight shift behaviors probed for major orientations, including a remarkable d-vector rotation under weak fields. This entitles UPt3_3 as the first example that a charged many body system forms a spin-triplet odd-par ity pairing at low temperatures and demonstrates unambiguously that the putative spin-orbit coupling in UPt3_3 is weak.Comment: 4 pages, 2 eps figures, to be published in J. Phys. Soc. Jpn. 67 (1998) No.

    Probing microwave fields and enabling in-situ experiments in a transmission electron microscope.

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    A technique is presented whereby the performance of a microwave device is evaluated by mapping local field distributions using Lorentz transmission electron microscopy (L-TEM). We demonstrate the method by measuring the polarisation state of the electromagnetic fields produced by a microstrip waveguide as a function of its gigahertz operating frequency. The forward and backward propagating electromagnetic fields produced by the waveguide, in a specimen-free experiment, exert Lorentz forces on the propagating electron beam. Importantly, in addition to the mapping of dynamic fields, this novel method allows detection of effects of microwave fields on specimens, such as observing ferromagnetic materials at resonance

    The philosophy of critical realism and childhood studies

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    Critical realism is a philosophy of social science that analyses and aims to remedy current problems and gaps. Basic tenets of positivist and quantitative research tend to contradict those of qualitative and interpretive research, and critical realism proposes ways to resolve the contradictions. Vital themes in childhood research that are reviewed in this article include a comparison with feminist research, critical realism, being and thought, transitive and intransitive, theory/practice consistency, agency and structure, closed and open systems, micro and macro in the global/local nexus, four planar social being, facts and values, and transformative change through the four-stage MELD dialectic. Critical realism aims to understand the world in order to be able move from coercion towards creative liberating power

    Effects of Magnetic Order on the Upper Critical Field of UPt3_3

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    I present a Ginzburg-Landau theory for hexagonal oscillations of the upper critical field of UPt3_3 near TcT_c. The model is based on a 2D2D representation for the superconducting order parameter, η=(η1,η2)\vec{\eta}=(\eta_1,\eta_2), coupled to an in-plane AFM order parameter, ms\vec{m}_s. Hexagonal anisotropy of Hc2H_{c2} arises from the weak in-plane anisotropy energy of the AFM state and the coupling of the superconducting order parameter to the staggered field. The model explains the important features of the observed hexagonal anisotropy [N. Keller, {\it et al.}, Phys. Rev. Lett. {\bf 73}, 2364 (1994).] including: (i) the small magnitude, (ii) persistence of the oscillations for TTcT\rightarrow T_c, and (iii) the change in sign of the oscillations for T>TT> T^{*} and T<TT< T^{*} (the temperature at the tetracritical point). I also show that there is a low-field crossover (observable only very near TcT_c) below which the oscillations should vanish.Comment: 9 pages in a RevTex (3.0) file plus 2 postscript figures (uuencoded). Submitted to Physical Review B (December 20, 1994)
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