738 research outputs found

    First--order continuous models of opinion formation

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    We study certain nonlinear continuous models of opinion formation derived from a kinetic description involving exchange of opinion between individual agents. These models imply that the only possible final opinions are the extremal ones, and are similar to models of pure drift in magnetization. Both analytical and numerical methods allow to recover the final distribution of opinion between the two extremal ones.Comment: 17 pages, 4 figure

    Cambridge as a place in economics

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    Cambridge as a geographical reference often crops up in the characterisation of the economic theories and approaches that developed in Cambridge (UK) between the 1920s and the 1960s with the contribution of economists who did not always share the same interests, background or attitudes, but who all lived and worked – for considerable periods of time – in that particular corner of the world. In order to reconstruct the Cambridge of those years and explore the space it represented for economics we have selected a group of economists and a span of time – essentially between the two wars, with a few encroachments in the years following on the death of Keynes. Cambridge was not only a place, but also a play of magnetic forces, drawing together and driving apart, where ideas emerged from an environment formed through intense human and professional relations, a well defined cultural tradition and a way of its own of organising work and study. We present the dramatis personae and the background to their actions, and consider the characteristics of intellectual and personal communication on the basis of which we are led to define the Cambridge economists examined more as a `group' than a school

    La influencia de las caracter?sticas del equipo fundador sobre el proceso de transformaci?n de una Pre-startup hacia una Startup

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    En diferentes pa?ses alrededor del mundo se vienen destinando amplios capitales financieros de origen p?blico y privado para impulsar el desarrollo de las denominadas start ups, sobretodo hacia aquellas que se encuentran en una etapa de formaci?n. Este inter?s radica sobretodo en impulsar la denominada ?destrucci?n creativa? que busca impulsar la noci?n Schumpeteriana como motor del crecimiento econ?mico, y que pueda soportar sobretodo el proceso de crecimiento de pa?ses en desarrollo. Tomando en consideraci?n el bajo ratio que se registra en la supervivencia de ?ste tipo de iniciativas, existe un creciente inter?s en estudiarlas durante su etapa temprana de gestaci?n. Estos potenciales ingresantes al mercado deber?n hacer un uso adecuado de sus escasos recursos y capacidades internas para explotar al m?ximo las oportunidades externas y, a pesar de su estado de organizaci?n incipiente, poder generar actividades y procesos que aseguren su supervivencia. As?, esta propuesta de investigaci?n se propone determinar cuales son los factores que influencian la supervivencia de una pre-start up hasta el hito de convertirse en una start up operativa, que consiga ingresar al mercado, sobretodo en el contexto de los pa?ses en desarrollo, que presentan recursos limitados. Asimismo, habi?ndose encontrado en la literatura registros sobre la diferenciaci?n que existe en los procesos de innovaci?n en los pa?ses en desarrollo con respecto a lo que se presenta en pa?ses desarrollados, se propone analizar el rol mediador de la innovaci?n que puede influenciar positivamente la supervivencia de las denominadas pre-start ups

    New radio observations of anomalous microwave emission in the HII region RCW175

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    We have observed the HII region RCW175 with the 64m Parkes telescope at 8.4GHz and 13.5GHz in total intensity, and at 21.5GHz in both total intensity and polarization. High angular resolution, high sensitivity, and polarization capability enable us to perform a detailed study of the different constituents of the HII region. For the first time, we resolve three distinct regions at microwave frequencies, two of which are part of the same annular diffuse structure. Our observations enable us to confirm the presence of anomalous microwave emission (AME) from RCW175. Fitting the integrated flux density across the entire region with the currently available spinning dust models, using physically motivated assumptions, indicates the presence of at least two spinning dust components: a warm component with a relatively large hydrogen number density n_H=26.3/cm^3 and a cold component with a hydrogen number density of n_H=150/cm^3. The present study is an example highlighting the potential of using high angular-resolution microwave data to break model parameter degeneracies. Thanks to our spectral coverage and angular resolution, we have been able to derive one of the first AME maps, at 13.5GHz, showing clear evidence that the bulk of the AME arises in particular from one of the source components, with some additional contribution from the diffuse structure. A cross-correlation analysis with thermal dust emission has shown a high degree of correlation with one of the regions within RCW175. In the center of RCW175, we find an average polarized emission at 21.5GHz of 2.2\pm0.2(rand.)\pm0.3(sys.)% of the total emission, where we have included both systematic and statistical uncertainties at 68% CL. This polarized emission could be due to sub-dominant synchrotron emission from the region and is thus consistent with very faint or non-polarized emission associated with AME.Comment: Accepted for publication in the Astrophysical Journa

    Self‐reported food and drug allergy in Maputo, Mozambique

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    Public Health. 2005 Jul;119(7):587-9. Self-reported food and drug allergy in Maputo, Mozambique. Lunet N, FalcĂŁo H, Sousa M, Bay N, Barros H. SourceDepartment of Hygiene and Epidemiology, University of Porto Medical School, Portugal. [email protected] PMID: 15925673 [PubMed - indexed for MEDLINE

    Automatic Optic Nerve Measurement: A New Tool to Standardize Optic Nerve Assessment in Ultrasound B-Mode Images

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    Transorbital sonography provides reliable information about the estimation of intra-cranial pressure by measuring the optic nerve sheath diameter (ONSD), whereas the optic nerve (ON) diameter (OND) may reveal ON atrophy in patients with multiple sclerosis. Here, an AUTomatic Optic Nerve MeAsurement (AUTONoMA) system for OND and ONSD assessment in ultrasound B-mode images based on deformable models is presented. The automated measurements were compared with manual ones obtained by two operators, with no significant differences. AUTONoMA correctly segmented the ON and its sheath in 71 out of 75 images. The mean error compared with the expert operator was 0.06 ± 0.52 mm and 0.06 ± 0.35 mm for the ONSD and OND, respectively. The agreement between operators and AUTONoMA was good and a positive correlation was found between the readers and the algorithm with errors comparable with the inter-operator variability. The AUTONoMA system may allow for standardization of OND and ONSD measurements, reducing manual evaluation variability

    PSK5 MANAGEMENT AND COST OF GENITAL WARTS IN ITALY

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    Optimization of dry storage for spent fuel from G.A. Siwabessy nuclear research reactor

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    © IJTech 2018. This study proposes a method of optimizing the dry storage design for nuclear-spent fuel from the G.A. Siwabessy research reactor at National Nuclear Energy Agency of Indonesia (BATAN). After several years in a spent fuel pool storage (wet storage), nuclear spent fuel is often moved to dry storage. Some advantages of dry storage compared with wet storage are that there is no generation of liquid waste, no need for a complex and expensive purification system, less corrosion concerns and that dry storage is easier to transport if in the future the storage needs to be sent to the another repository or to the final disposal. In both wet and dry storage, the decay heat of spent fuel must be cooled to a safe temperature to prevent cracking of the spent fuel cladding from where hazardous radioactive nuclides could be released and harm humans and the environment. Three optimization scenarios including the thermal safety single-objective, the economic single-objective and the multi-objective optimizations are obtained. The optimum values of temperature and cost for three optimization scenarios are 317.8K (44.7°C) and 11638.1 USfortheoptimizedsingle−objectivethermalsafetymethod,337.1K(64.0°C)and6345.2US for the optimized single-objective thermal safety method, 337.1K (64.0°C) and 6345.2 US for the optimized single-objective cost method and 325.1K (52.0°C) and 8037.4 US$ for the optimized multi-objective method, respectively

    Why Me? To Be an Ultra-Responder to Antiplatelet Therapy: A Case Report

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    Background: Platelet function testing is a valid tool to investigate the clinical response to antiplatelet therapy in different clinical settings; in particular, it might supply helpful information in patients with cerebrovascular disease. Oral antiplatelet treatment, such as Aspirin (ASA) and Clopidogrel, is the gold standard in secondary stroke prevention of non-cardiogenic ischemic stroke; conversely, its application as a primary prevention therapy is not routinely recommended in patients with vascular risk factors. Multiple electrode platelet aggregometry (MEA) impedance aggregometer is a validated device to test platelet inhibition induced by ASA or Clopidogrel. Case Report: We report the case of a 78-year-old patient without relevant clinical history, taking ASA as primary prevention strategy, who was admitted for sudden onset of dysarthria and left facial hyposthenia during physical effort. Brain CT revealed two small subcortical bilateral spontaneous intracranial hemorrhages. Platelet aggregometry with MEA performed upon admission revealed a very strong platelet inhibition induced by ASA (result of the ASPI Test was 5 U, consistent with an ultra-responsiveness to ASA, and the cutoff value of correct responsiveness is <40 U). MRI at longitudinal follow-up revealed the presence of two small cavernous angioma underlying hemorrhagic spots. Conclusion: The evaluation of platelet reactivity in stroke patients undergoing antiplatelet therapies, not commonly performed in clinical practice, could be useful to optimize prevention strategies; the verification of the biological effectiveness of ASA or Clopidogrel could be a valid tool in the definition of each patient's risk profile, particularly in patients with cerebrovascular disease known to be at increased risk for both hemorrhagic and thrombotic complications
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