1,298 research outputs found

    Influence of Start-Up Time on the Purging of Salt Water From a Cavity by an Overflow of Fresh Water

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    This paper presents the results of a numerical investigation of a flow in which salt water is purged from a square cavity by an overflow of fresh water. Ramp inlet velocity boundary conditions are used in order to describe the influence of the start up time on the amount of saline water purged from the cavity in the initial splash. As the time to start-up is increased, the volume of saline liquid purged from the pool is decreased. This has important implications in the management of river systems and the potential to purge the saline water within the river base by an environmental release, where it is expected that the time to startup is measured in days

    An Examination of the Relationship Between Perfectionism and Neurological Functioning

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    Clinical perfectionism is the rigid pursuit of high standards, interfering with functioning. Little research has explored neural patterns in clinical perfectionism. The present study explores neural correlates of clinical perfectionism, before and after receiving ten 50-minute, weekly sessions of acceptance and commitment therapy (ACT), as compared to low-perfectionist controls, in specific cortical structures: the dorsolateral prefrontal cortex (DLPFC), medial prefrontal cortex (MPFC), right inferior parietal lobule (IPL). Participants in the perfectionist condition (n = 43) were from a randomized controlled trial evaluating ACT for clinical perfectionism and low-perfectionist controls were undergraduate students (n = 12). Participants completed three tasks (editing a passage, mirror image tracing, circle tracing) using functional near-infrared spectroscopy (fNIRS) to measure neural activation. Results indicate that only the mirror image tracing task was associated with reduced HbT in the DLPFC and MPFC of the perfectionists whereas activation in the other tasks were relatively similar. There were no differences were observed in the right DLPFC, MPFC, and right IPL between the posttreatment perfectionist and non-perfectionist control groups. Our findings suggest an unclear relationship between neural activation and perfectionism

    A Preliminary Investigation of the Effect of Acceptance and Commitment Therapy on Neural Activation in Clinical Perfectionism

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    Clinical perfectionism is associated with various cognitive processes including performance monitoring and emotion regulation. This exploratory study analyzed neurological data from a randomized controlled trial for clinical perfectionism that compared acceptance and commitment therapy (ACT) to a waitlist control. The objective was to assess the effect of ACT on neural activation. Twenty-nine participants underwent a functional near-infrared spectroscopy assessment during which they completed behavioral tasks designed to elicit error detection and error generation at pre- and posttreatment. The hemodynamic response function (HRF) in the dorsolateral prefrontal cortex, dorsomedial prefrontal cortex, and right inferior parietal lobe was analyzed using mixed effects models. In all areas, we found reductions or smaller increases in the total HRF for experimental tasks from pre- to posttreatment in the ACT condition compared to the waitlist condition. Decreases in total oxygenated hemoglobin are consistent with diminished recruitment of neurons in response to previously emotionally salient stimuli, possibly representing greater cognitive processing efficiency. Our preliminary findings tentatively support the processes of change posited by the theory underlying ACT and highlight the need for more precise methodology in neurological assessment to adequately evaluate how treatment affects neurological function. Limitations include lack of an active comparison condition and behavioral data

    On a Watson-like Uniqueness Theorem and Gevrey Expansions

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    We present a maximal class of analytic functions, elements of which are in one-to-one correspondence with their asymptotic expansions. In recent decades it has been realized (B. Malgrange, J. Ecalle, J.-P. Ramis, Y. Sibuya et al.), that the formal power series solutions of a wide range of systems of ordinary (even non-linear) analytic differential equations are in fact the Gevrey expansions for the regular solutions. Watson's uniqueness theorem belongs to the foundations of this new theory. This paper contains a discussion of an extension of Watson's uniqueness theorem for classes of functions which admit a Gevrey expansion in angular regions of the complex plane with opening less than or equal to (\frac \pi k,) where (k) is the order of the Gevrey expansion. We present conditions which ensure uniqueness and which suggest an extension of Watson's representation theorem. These results may be applied for solutions of certain classes of differential equations to obtain the best accuracy estimate for the deviation of a solution from a finite sum of the corresponding Gevrey expansion.Comment: 18 pages, 4 figure

    Creative and Stylistic Devices Employed by Children During a Storybook Narrative Task: A Cross-Cultural Study

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    Purpose: The purpose of this study was to analyze the effects of culture on the creative and stylistic features children employ when producing narratives based on wordless picture books. Method: Participants included 60 first- and second-grade African American, Latino American, and Caucasian children. A subset of narratives based on wordless picture books collected as part of a larger study was coded and analyzed for the following creative and stylistic conventions: organizational style (topic centered, linear, cyclical), dialogue (direct, indirect), reference to character relationships (nature, naming, conduct), embellishment (fantasy, suspense, conflict), and paralinguistic devices (expressive sounds, exclamatory utterances). Results: Many similarities and differences between ethnic groups were found. No significant differences were found between ethnic groups in organizational style or use of paralinguistic devices. African American children included more fantasy in their stories, Latino children named their characters more often, and Caucasian children made more references to the nature of character relationships. Conclusion: Even within the context of a highly structured narrative task based on wordless picture books, culture influences children’s production of narratives. Enhanced understanding of narrative structure, creativity, and style is necessary to provide ecologically valid narrative assessment and intervention for children from diverse cultural backgrounds

    Information theory analysis of Australian humpback whale song

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    Songs produced by migrating whales were recorded off the coast of Queensland, Australia, over six consecutive weeks in 2003. Forty-eight independent song sessions were analyzed using information theory techniques. The average length of the songs estimated by correlation analysis was approximately 100 units, with song sessions lasting from 300 to over 3100 units. Song entropy, a measure of structural constraints, was estimated using three different methodologies: (1) the independently identically distributed model, (2) a first-order Markov model, and (3) the nonparametric sliding window match length (SWML) method, as described by Suzuki et al. [(2006). “Information entropy of humpback whale song,” J. Acoust. Soc. Am. 119, 1849–1866]. The analysis finds that the song sequences of migrating Australian whales are consistent with the hierarchical structure proposed by Payne and McVay [(1971). “Songs of humpback whales,” Science 173, 587–597], and recently supported mathematically by Suzuki et al. (2006) for singers on the Hawaiian breeding grounds. Both the SWML entropy estimates and the song lengths for the Australian singers in 2003 were lower than that reported by Suzuki et al. (2006) for Hawaiian whales in 1976–1978; however, song redundancy did not differ between these two populations separated spatially and temporally. The average total information in the sequence of units in Australian song was approximately 35 bits/song. Aberrant songs (8%) yielded entropies similar to the typical songs

    Using consecutive Rapid Participatory Appraisal studies to assess, facilitate and evaluate health and social change in community settings

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    BACKGROUND: To investigate how a relatively socio-economically deprived community's needs have changed over time, assess which recommendations from an earlier assessment were implemented and sustained, and consider whether serial Rapid Participatory Appraisal is an effective health research tool that can promote community development and has utility in assessing longitudinal change. METHODS: Rapid Participatory Appraisal involves communities in identifying and challenging their own health-related needs. Information on ten health and social aspects was collated from existing documentation, neighbourhood observations, and interviews with a range of residents and key informants, providing a composite picture of the community's structure, needs and services. RESULTS: The perceived needs after 10 years encompassed a wide construct of health, principally the living environment, housing, and lack of finance. Most identified upstream determinants of health rather than specific medical conditions as primary concerns. After the initial Rapid Participatory Appraisal many interviewees took the recommendations forward, working to promote a healthier environment and advocate for local resources. Interventions requiring support from outwith the community were largely not sustained. CONCLUSION: Rapid Participatory Appraisal proved valuable in assessing long-term change. The community's continuing needs were identified, but they could not facilitate and sustain change without the strategic support of key regional and national agencies. Many repeatedly voiced concerns lay outwith local control: local needs assessment must be supported at higher levels to be effective

    Measurements of fiducial and differential cross sections for Higgs boson production in the diphoton decay channel at s√=8 TeV with ATLAS

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    Measurements of fiducial and differential cross sections are presented for Higgs boson production in proton-proton collisions at a centre-of-mass energy of s√=8 TeV. The analysis is performed in the H → γγ decay channel using 20.3 fb−1 of data recorded by the ATLAS experiment at the CERN Large Hadron Collider. The signal is extracted using a fit to the diphoton invariant mass spectrum assuming that the width of the resonance is much smaller than the experimental resolution. The signal yields are corrected for the effects of detector inefficiency and resolution. The pp → H → γγ fiducial cross section is measured to be 43.2 ±9.4(stat.) − 2.9 + 3.2 (syst.) ±1.2(lumi)fb for a Higgs boson of mass 125.4GeV decaying to two isolated photons that have transverse momentum greater than 35% and 25% of the diphoton invariant mass and each with absolute pseudorapidity less than 2.37. Four additional fiducial cross sections and two cross-section limits are presented in phase space regions that test the theoretical modelling of different Higgs boson production mechanisms, or are sensitive to physics beyond the Standard Model. Differential cross sections are also presented, as a function of variables related to the diphoton kinematics and the jet activity produced in the Higgs boson events. The observed spectra are statistically limited but broadly in line with the theoretical expectations

    Search for squarks and gluinos in events with isolated leptons, jets and missing transverse momentum at s√=8 TeV with the ATLAS detector

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    The results of a search for supersymmetry in final states containing at least one isolated lepton (electron or muon), jets and large missing transverse momentum with the ATLAS detector at the Large Hadron Collider are reported. The search is based on proton-proton collision data at a centre-of-mass energy s√=8 TeV collected in 2012, corresponding to an integrated luminosity of 20 fb−1. No significant excess above the Standard Model expectation is observed. Limits are set on supersymmetric particle masses for various supersymmetric models. Depending on the model, the search excludes gluino masses up to 1.32 TeV and squark masses up to 840 GeV. Limits are also set on the parameters of a minimal universal extra dimension model, excluding a compactification radius of 1/R c = 950 GeV for a cut-off scale times radius (ΛR c) of approximately 30

    Measurement of χ c1 and χ c2 production with s√ = 7 TeV pp collisions at ATLAS

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    The prompt and non-prompt production cross-sections for the χ c1 and χ c2 charmonium states are measured in pp collisions at s√ = 7 TeV with the ATLAS detector at the LHC using 4.5 fb−1 of integrated luminosity. The χ c states are reconstructed through the radiative decay χ c → J/ψγ (with J/ψ → μ + μ −) where photons are reconstructed from γ → e + e − conversions. The production rate of the χ c2 state relative to the χ c1 state is measured for prompt and non-prompt χ c as a function of J/ψ transverse momentum. The prompt χ c cross-sections are combined with existing measurements of prompt J/ψ production to derive the fraction of prompt J/ψ produced in feed-down from χ c decays. The fractions of χ c1 and χ c2 produced in b-hadron decays are also measured
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