3,046 research outputs found

    The Apparent Madness of Crowds: Irrational collective behavior emerging from interactions among rational agents

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    Standard economic theory assumes that agents in markets behave rationally. However, the observation of extremely large fluctuations in the price of financial assets that are not correlated to changes in their fundamental value, as well as the extreme instance of financial bubbles and crashes, imply that markets (at least occasionally) do display irrational behavior. In this paper, we briefly outline our recent work demonstrating that a market with interacting agents having bounded rationality can display price fluctuations that are {\em quantitatively} similar to those seen in real markets.Comment: 4 pages, 1 figure, to appear in Proceedings of International Workshop on "Econophysics of Stock Markets and Minority Games" (Econophys-Kolkata II), Feb 14-17, 200

    Linguistic incompetence: giving an account of researching multilingually

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    This paper considers the place of linguistic competence and incompetence in the context of researching multilingually. It offers a critique of the concept of competence and explores the performative dimensions of multilingual research and its narration, through the philosophy of Judith Butler, and in particular her study Giving an account of oneself. It explores aspects of risk, justice, narrative limit and a morality of multilingualism in emergent multilingual research frameworks. These theoretical dimensions are explored through consideration of ‘linguistically incompetent’ ethnographic work with refugees and asylum seekers, in contexts of hospitality and in life long learning research in the Gaza Strip, and of early attempts to learn new languages. The paper offers a prospect of a relational approach to researching multilingually and affirms the vulnerability at the heart of linguistic hospitality

    Spectral engineering of optical fiber preforms through active nanoparticle doping

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    Europium doped alkaline earth fluoride [Eu:AEF(2) (AE = Ca, Sr, Ba)] nanoparticles were synthesized and systematically incorporated into the core of modified chemical vapor deposition (MCVD)-derived silica-based preforms by solution doping. The resulting preforms were examined to determine the impact of the nanoparticles chemistry on the spectroscopic behavior of the glass. The dominant existence of Eu3+ was demonstrated in all preforms, which is in contrast to conventional solution doped preforms employing dissolved europium salts where Eu2+ is primarily observed. Raman spectroscopy and fluorescence lifetime measurements indicated that the nanoparticles composition is effective in controlling, at a local chemical and structural level, the spectroscopic properties of active dopants in optical fiber glasses. Further, there is a systematic and marked increase in radiative lifetime, tau, of the Eu3+ emission that follows the cationic mass; tau(Ca) \u3c tau(Sr) \u3c tau(Ba) with the BaF2-derived sample yielding a 37% lengthening of the lifetime over the CaF2-derived one. Such nanoscale control of what otherwise is silica glass could be useful for realizing property-enhanced and tailored spectroscopic performance from otherwise standard materials, e.g., vapor-derived silica, in next generation optical fibers

    Spectral Engineering of Optical Fiber Preforms Through Active Nanoparticle Doping

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    Europium doped alkaline earth fluoride [Eu:AEF2 (AE = Ca, Sr, Ba)] nanoparticles were synthesized and systematically incorporated into the core of modified chemical vapor deposition (MCVD)-derived silica-based preforms by solution doping. The resulting preforms were examined to determine the impact of the nanoparticles chemistry on the spectroscopic behavior of the glass. The dominant existence of Eu3+ was demonstrated in all preforms, which is in contrast to conventional solution doped preforms employing dissolved europium salts where Eu2+ is primarily observed. Raman spectroscopy and fluorescence lifetime measurements indicated that the nanoparticles composition is effective in controlling, at a local chemical and structural level, the spectroscopic properties of active dopants in optical fiber glasses. Further, there is a systematic and marked increase in radiative lifetime, τ, of the Eu3+ emission that follows the cationic mass; τCa \u3c τSr \u3c τBa with the BaF2-derived sample yielding a 37% lengthening of the lifetime over the CaF2-derived one. Such nanoscale control of what otherwise is silica glass could be useful for realizing property-enhanced and tailored spectroscopic performance from otherwise “standard” materials, e.g., vapor-derived silica, in next generation optical fibers

    Effectiveness of peer educators on the uptake of mobile X-ray tuberculosis screening at homeless hostels: a cluster randomised controlled trial.

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    To compare current practice for encouraging homeless people to be screened for tuberculosis on a mobile digital X-ray unit in London, UK, with the additional use of volunteer peer educators who have direct experience of tuberculosis, homelessness or both

    Evaluation of a rolling rehabilitation programme for patients with non-specific low back pain in primary care: an observational cohort study

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    Aim The Back Rehabilitation Programme (BRP) is a group exercise programme for patients with non-specific low back pain (NSLBP) that combines cognitive behavioural therapy principles and therapeutic exercise to empower patients to self-manage their condition. Poor attendance and high attrition rates resulted in changes to the format of the programme from a standard sequential approach to a continual rolling approach. The aim of this study was to evaluate the effectiveness of this new approach on patient outcomes and its impact on attendance rates. Method A service evaluation, using a retrospective, observational cohort design, of all patients with NSLBP who attended the BRP during a 12-month period was undertaken. Outcome measures used were as follows: Bournemouth Questionnaire (BQ); fitness tests: sit to stand test, step test and walk test (taken at baseline and post programme); and attendance (taken post programme). Results Of the patients, 56% had an improved BQ score ≄ 47%, indicating a clinically significant change. Inferential testing showed statistically significant improvements in the BQ and all three fitness tests post programme (P< 0.0001). In total, 62 patients attended the rolling BRP, and 41 patients (66%) completed. Thus, the percentage of patients completing the new programme had doubled compared with the original standard programme. Conclusion Patients with NSLBP who attended the continual rolling BRP show clinical and statistical improvements. The rolling format also appeared to enhance patient attendance. As such, the rolling BRP should be considered by practitioners as an effective management strategy when treating patients with NSLBP

    Teleology and Realism in Leibniz's Philosophy of Science

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    This paper argues for an interpretation of Leibniz’s claim that physics requires both mechanical and teleological principles as a view regarding the interpretation of physical theories. Granting that Leibniz’s fundamental ontology remains non-physical, or mentalistic, it argues that teleological principles nevertheless ground a realist commitment about mechanical descriptions of phenomena. The empirical results of the new sciences, according to Leibniz, have genuine truth conditions: there is a fact of the matter about the regularities observed in experience. Taking this stance, however, requires bringing non-empirical reasons to bear upon mechanical causal claims. This paper first evaluates extant interpretations of Leibniz’s thesis that there are two realms in physics as describing parallel, self-sufficient sets of laws. It then examines Leibniz’s use of teleological principles to interpret scientific results in the context of his interventions in debates in seventeenth-century kinematic theory, and in the teaching of Copernicanism. Leibniz’s use of the principle of continuity and the principle of simplicity, for instance, reveal an underlying commitment to the truth-aptness, or approximate truth-aptness, of the new natural sciences. The paper concludes with a brief remark on the relation between metaphysics, theology, and physics in Leibniz

    Switching to Once-Daily Liraglutide From Twice-Daily Exenatide Further Improves Glycemic Control in Patients With Type 2 Diabetes Using Oral Agents

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    OBJECTIVETo evaluate efficacy and safety of switching from twice-daily exenatide to once-daily liraglutide or of 40 weeks of continuous liraglutide therapy.RESEARCH DESIGN AND METHODSWhen added to oral antidiabetes drugs in a 26-week randomized trial (Liraglutide Effect and Action in Diabetes [LEAD]-6), liraglutide more effectively improved A1C, fasting plasma glucose, and the homeostasis model of ÎČ-cell function (HOMA-B) than exenatide, with less persistent nausea and hypoglycemia. In this 14-week extension of LEAD-6, patients switched from 10 ÎŒg twice-daily exenatide to 1.8 mg once-daily liraglutide or continued liraglutide.RESULTSSwitching from exenatide to liraglutide further and significantly reduced A1C (0.32%), fasting plasma glucose (0.9 mmol/l), body weight (0.9 kg), and systolic blood pressure (3.8 mmHg) with minimal minor hypoglycemia (1.30 episodes/patient-year) or nausea (3.2%). Among patients continuing liraglutide, further significant decreases in body weight (0.4 kg) and systolic blood pressure (2.2 mmHg) occurred with 0.74 episodes/patient-year of minor hypoglycemia and 1.5% experiencing nausea.CONCLUSIONSConversion from exenatide to liraglutide is well tolerated and provides additional glycemic control and cardiometabolic benefits
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