100 research outputs found

    Correlations and fluctuations studied with ALICE

    Full text link
    The measurement of particle correlations and event-by-event fluctuations of physical observables allows to study a large variety of properties of the matter produced in ultra relativistic heavy-ion collisions. We will present results for two-particle correlations, mean transverse momentum fluctuations, and net charge fluctuations in Pb-Pb collisions at 2.76 TeV.Comment: 7 pages, 5 figures, Proceedings submitted for the 28th Winter Workshop on Nuclear Dynamics, Puerto Rico, April 7-14, 2012; corrected typo

    “More than Meets the Eye” - Analyzing the Success of User Queries in Oria

    Get PDF
    Discovery systems allow academic library users to locate a wider range of resources than previous OPACs. However, actual usage of these systems may still be challenging. The main aim of this research is to get a better understanding of the hurdles users face while searching contemporary library systems.This study utilizes a transaction log analysis approach, using popular and zero result queries datasets gathered from the statistics module of a library discovery system. It explores what types of queries users perform, how successful the queries are, and examines underlying reasons for unsuccessful queries. To our knowledge, this is the first academic paper to use data originating from built-in transaction logs of the Oria library discovery system.The analysis shows that queries are often curriculum-related: we could pinpoint a relation with curriculum for 58% of the popular queries, and 28% for the zero result searches. A vast majority of popular queries refer to books, databases and journals, and over half of the queries used the title to locate a resource. 20% of the popular queries turned out to be unsuccessful. Zero result queries typically involve long queries, and in many cases consist of pasted reference citations.Our conclusion is that the examined discovery system is rather sensitive. Whilst this suggests the importance of increasing users' information search skills, it also points to the need for enhancing discovery systems and their underlying metadata. Furthermore, due to the prominence of curriculum-related queries, a better integration of curriculum materials ought to be achieved

    The role of occupational meaningfulness and citizenship as mediators between occupational status and recovery: a cross-sectional study among residents with co-occurring problems

    Get PDF
    Purpose Engagement in meaningful occupations and being included as full citizens of the community, is essential in everyday life, and may be of considerable relevance for recovery and quality of life. However, persons with co-occurring substance use and mental health problems experience extensive obstacles to engagement in occupations and citizenship. The relationship between objective measures of occupational status and subjective experiences of occupational meaningfulness, citizenship and recovery, is scarcely researched in the context of co-occurring problems. As such, the purpose of this study is to examine associations between occupational status, occupational meaningfulness, citizenship and recovery and quality of life and to examine the roles of occupational meaningfulness and citizenship as possible mediators between occupational status and recovery and quality of life. Design/methodology/approach The study used a cross-sectional design with a sample of 104 residents at supported housing sites across six Norwegian cities. Findings Linear regression analyzes indicated that occupational status was significantly associated with the citizenship domains caring for others and community participation and with the quality of life measure positive affect. Occupational meaningfulness and citizenship were significantly associated with different domains of recovery and quality of life. Furthermore, mediation analyzes showed that the relationship between occupational status and recovery and quality of life was mediated by caring for others and community participation. Originality/value The results suggest that emphasizing opportunities for occupational meaningfulness and citizenship in practice may have positive implications for recovery among persons with co-occurring problems.acceptedVersio

    Retrieval, reuse, revision and retention in case-based reasoning

    Get PDF
    El original está disponible en www.journals.cambridge.orgCase-based reasoning (CBR) is an approach to problem solving that emphasizes the role of prior experience during future problem solving (i.e., new problems are solved by reusing and if necessary adapting the solutions to similar problems that were solved in the past). It has enjoyed considerable success in a wide variety of problem solving tasks and domains. Following a brief overview of the traditional problem-solving cycle in CBR, we examine the cognitive science foundations of CBR and its relationship to analogical reasoning. We then review a representative selection of CBR research in the past few decades on aspects of retrieval, reuse, revision, and retention.Peer reviewe

    Gauge invariant definition of the jet quenching parameter

    Full text link
    In the framework of Soft-Collinear Effective Theory, the jet quenching parameter, q^\hat{q}, has been evaluated by adding the effect of Glauber gluon interactions to the propagation of a highly-energetic collinear parton in a medium. The result, which holds in covariant gauges, has been expressed in terms of the expectation value of two Wilson lines stretching along the direction of the four-momentum of the parton. In this paper, we show how that expression can be generalized to an arbitrary gauge by the addition of transverse Wilson lines. The transverse Wilson lines are explicitly computed by resumming interactions of the parton with Glauber gluons that appear only in non-covariant gauges. As an application of our result, we discuss the contribution to q^\hat{q} coming from transverse momenta of order g2Tg^2T in a medium that is a weakly-coupled quark-gluon plasma.Comment: 31 pages, 7 figures; journal versio

    Patient, nursing and medical staff experiences and perceptions of the care of people with palliative esophagogastric cancer

    Get PDF
    Background: Esophagogastric cancer is the fifth most common malignancy and its incidence is increasing. The disease progresses quickly and five-year survival rates are poor. Treatment with palliative intent is provided for the majority of patients but there remains a lack of empirical evidence on the most effective service models to support esophagogastric cancer patients. Objectives: The overall objective of this systematic review was to synthesize the best available evidence on the experiences and perceptions of patients and health professionals with regard to the care of people diagnosed with palliative esophagogastric cancer. Inclusion criteria Types of participants: The review considered studies that included patients diagnosed with palliative esophagogastric cancer and any health professionals involved in the delivery of palliative care to this patient group in a hospital, home or community setting. Phenomena of interest: The review considered studies that investigated the experiences and perceptions of people diagnosed with palliative esophagogastric cancer and staff working with these people. Context: Studies that were carried out in any setting, including in-patient and outpatient areas, specialist cancer and non-specialist palliative care services and those were any patient were in receipt or had experiences of palliative care services were considered. All types of health practitioners delivering palliative care to esophagogastric cancer patients were considered. Types of studies: Studies that focused on qualitative data, including, but not limited to, designs such as phenomenology, grounded theory, ethnography, action research, feminist research and narrative approaches were considered. Mixed methods studies were considered in the review only if qualitative findings were reported separately. Search strategy: A three-step search strategy was utilized. A total 11 databases were searched for studies from 2000 onward, followed by hand searching of reference lists. Methodological quality: Methodological quality was assessed using the Joanna Briggs Institute Qualitative Assessment and Review Instrument critical appraisal tool (JBI-QARI). Data extraction: Qualitative findings were extracted using the JBI-QARI data extraction Instrument. Data synthesis: Qualitative research findings were pooled using a pragmatic meta-aggregative approach. Results: The review included two publications. There were 46 findings which were aggregated into four categories and one overall synthesized finding: “In addition to support for physical needs, patients need support that takes into account changing life situations to achieve the best quality of life.” Conclusions: The review shows that patients value services and support that addresses their complex, fluctuating and highly individual needs. No evidence was uncovered regarding how these services should be designed and delivered

    Consequences of temperature fluctuations in observables measured in high energy collisions

    Full text link
    We review the consequences of intrinsic, nonstatistical temperature fluctuations as seen in observables measured in high energy collisions. We do this from the point of view of nonextensive statistics and Tsallis distributions. Particular attention is paid to multiplicity fluctuations as a first consequence of temperature fluctuations, to the equivalence of temperature and volume fluctuations, to the generalized thermodynamic fluctuations relations allowing us to compare fluctuations observed in different parts of phase space, and to the problem of the relation between Tsallis entropy and Tsallis distributions. We also discuss the possible influence of conservation laws on these distributions and provide some examples of how one can get them without considering temperature fluctuations.Comment: Revised version of the invited contribution to The European Physical Journal A (Hadrons and Nuclei) topical issue about 'Relativistic Hydro- and Thermodynamics in Nuclear Physics' guest eds. Tamas S. Biro, Gergely G. Barnafoldi and Peter Va

    Single-step hydrogen production from NH3, CH4, and biogas in stacked proton ceramic reactors

    Get PDF
    Proton ceramic reactors offer efficient extraction of hydrogen from ammonia, methane, and biogas by coupling endothermic reforming reactions with heat from electrochemical gas separation and compression. Preserving this efficiency in scale-up from cell to stack level poses challenges to the distribution of heat and gas flows and electric current throughout a robust functional design. Here, we demonstrate a 36-cell well-balanced reactor stack enabled by a new interconnect that achieves complete conversion of methane with more than 99% recovery to pressurized hydrogen, leaving a concentrated stream of carbon dioxide. Comparable cell performance was also achieved with ammonia, and the operation was confirmed at pressures exceeding 140 bars. The stacking of proton ceramic reactors into practical thermo-electrochemical devices demonstrates their potential in efficient hydrogen production.This work was supported by Norway’s Ministry of Petroleum and Energy through the Gassnova project CLIMIT grant 618191 in partnership with Engie SA, Equinor, ExxonMobil, Saudi Aramco, Shell, and TotalEnergies and the Research Council of Norway NANO2021 project DynaPro grant 296548

    Custom stems for femoral deformity in patients less than 40 years of age: 70 hips followed for an average of 14 years

    Get PDF
    Background and purpose Femoral deformity associated with osteoarthritis is a challenge for both the surgeon and the implant. Many of the patients with these deformities are young. Standard implants can be difficult to fit into these femurs. We prospectively evaluated the outcome of custom uncemented femoral stems in young patients
    • …
    corecore