507 research outputs found

    Spatial interactions in agent-based modeling

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    Agent Based Modeling (ABM) has become a widespread approach to model complex interactions. In this chapter after briefly summarizing some features of ABM the different approaches in modeling spatial interactions are discussed. It is stressed that agents can interact either indirectly through a shared environment and/or directly with each other. In such an approach, higher-order variables such as commodity prices, population dynamics or even institutions, are not exogenously specified but instead are seen as the results of interactions. It is highlighted in the chapter that the understanding of patterns emerging from such spatial interaction between agents is a key problem as much as their description through analytical or simulation means. The chapter reviews different approaches for modeling agents' behavior, taking into account either explicit spatial (lattice based) structures or networks. Some emphasis is placed on recent ABM as applied to the description of the dynamics of the geographical distribution of economic activities, - out of equilibrium. The Eurace@Unibi Model, an agent-based macroeconomic model with spatial structure, is used to illustrate the potential of such an approach for spatial policy analysis.Comment: 26 pages, 5 figures, 105 references; a chapter prepared for the book "Complexity and Geographical Economics - Topics and Tools", P. Commendatore, S.S. Kayam and I. Kubin, Eds. (Springer, in press, 2014

    Students Engagement in School, Giftedness and Creativity: A literature review

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    Este E-Book reúne um conjunto de investigações apresentadas no “I Congresso Internacional Envolvimento dos Alunos na Escola: Perspetivas da Psicologia e Educação” (ICIEAE), organizado no âmbito do “Projeto PTDC/CPE-CED/114362/2009 - Envolvimento dos Alunos na Escola: Diferenciação e Promoção” (EAE-DP), financiado pela Fundação para a Ciência e a Tecnologia (FCT).Background: The importance of the construct “students engagement in school” (SES) has been recently pointed out in research and literature; however, there is a lack of studies about the relationship between this variable and personal variables, such as giftedness and creativity. These latter variables are conceptualized as a result of the convergence of personal and contextual variables, in which development and learning processes play a relevant role. Giftedness has been studied in its relationship with creativity, which, in turn, appears related to school context. Purpose: This article reviews the literature on the relation between students’ engagement in school and each of the variables of students’ giftedness and students’ creativity, as perceived by the students and their teachers. The importance of this relation arises from the idea that students perceived as having above average capacities, or as creative, have high motivation for learning and engagement in school. Giftedness has been studied in its relationship with creativity, which, in turn, appears related to school context. Method: In order to describe the state of art of student’s engagement in school and Giftedness and Creativity, we prepared a narrative review. Conclusions: Although studies on the relationship between creativity, giftedness and the students’ behavior require further research, the use of creativity as a teaching-learning instrument appears related to school satisfaction and students’ academic performance. The literature review highlights the need to develop research, particularly of quasi-experimental type, on the relationship between students’ engagement in school and the variables giftedness and creativity, as well as on its effects on academic achievement

    Detection and distribution of European stone fruit yellows (ESFY) in apricot cv. ‘Bergeron’ and epidemiological studies in the province of Trento (Italy)

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    The aim was to investigate the performance of ‘Bergeron’ on ‘Wavit’ in 4 experimental fields, in the province of Trento (Italy), where European stone fruit yellows (ESFY) caused by “Candidatus Phytoplasma prunorum” has been constantly spreading since 2000.This included visual inspections for typical symptoms (early bud-break during dormancy and premature leaf-roll) and a highly sensitive Real time-PCR (Rt-PCR) assay. 25 % of the propagation material was checked with this method and found to be healthy, before planting in 2005.The epidemiology of the disease was also studied by focusing on: the presence of the vector Cacopsylla pruni (Scopoli) on conifers, the detection of “Ca. P. prunorum” in psyllid eggs and the transmission efficiency at different stages. This was done by exposing apricot trees in 2 locations, during 2 periods from January to July, to the overlapping presence in the orchards of the re-immigrants and the new generation of C. pruni. The results obtained demonstrated that ‘Bergeron’ seems to be highly susceptible to ESFY: typical bud-break was rarely observed, but up to 20-30% of the plants showed premature leaf-roll, fruit deformation and dieback. C. pruni was caught only once on Picea abies during winter; “Ca. P. prunorum” was found in 4 egg samples from 2 locations and the preliminary results on the exposed trees confirmed that the re-immigrants could be the most efficient vectors at least on apricot.Keywords: Prunus armeniaca, cultivar ‘Bergeron’, Real time-PCR, “Candidatus Phytoplasma prunorum”,epidemiolog

    Endometriosis in the time of internet: how web navigation affects women with endometriosis

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    Objectives: Patients often search for health-related information on the internet allthough this trend may have some benefits, it also has some risks, such as misinformation. The aim of this study is to evaluate how Internet information seeking affect the level of anxiety in patients with endometriosis. Materials and methods: This prospective observational study was conducted at our outpatient clinic between March 2019 and December 2020. We enrolled We enrolled all patients with a confirmed sonographic diagnosis of endometriosis who had sought information about the disease prior to our visit. We divided them into two groups based on the source of information (Internet only vs multiple sources). Before the visit, we asked women to fill-in validated questionnaires about anxiety, such as the Generalized Anxiety Disorder-7 (GAD) and the Spielberg State Trait Anxiety Inventory (STAI- Y6) and the Endometriosis Health Profile (EHP) − 5. After the visit, the STAI-Y6 was resubmitted to each woman. Results: We enrolled 200 women who filled-in the questionnaires: 46 reported the Internet as the only source of information, 52 sought information also from medically qualified sources, 74 consulted only healthcare professionals, and 28 resorted to medical journals. Women who used the Internet as their exclusive source of information were younger on average and their STAI-Y6 score after the visit was significantly lower compared to other group (34.1 ± 11.5 vs 42.1 ± 14.7, p =.001). Moreover, the difference between the STAI-Y6 scores before and after our assessment was higher in these women (-18.3 ± 14.7 vs −10.3 ± 16.5, p =.003). Conclusions: Women who sought information online were younger, had lower levels of state trait anxiety after our medical evaluation, and a had a greater reduction in anxiety levels after our examination compared to women who consulted other sources to learn more about endometriosis.KEY MESSAGES Women using only Internet are younger than those who use other sources of information. Women who researched symptoms online showed higher pre-examination anxiety levels. Patients with severe pain symptoms consulted both the internet and professionals

    Implementation of Radio-Frequency Deflecting Devices for Comprehensive High-Energy Electron Beam Diagnosis

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    In next-generation light sources, high-brightness electron beams are used in a free-electron laser configuration to produce light for use by scientists and engineers in numerous fields of research. High-brightness beams are described for such light sources as having low transverse and longitudinal emittances, high peak currents, and low slice emittance and energy spread. The optimal generation and preservation of such high-brightness electron beams during the acceleration process and propagation to and through the photon-producing element is imperative to the quality and performance of the light source. To understand the electron beam's phase space in the accelerating section of a next-generation light source machine, we employed radio-frequency cavities operating in a deflecting mode in conjunction with a magnetic spectrometer and imaging system for both low (250 MeV) and high (1.2 GeV) electron energies. This high-resolution, high-energy system is an essential diagnostic for the optimization and control of the electron beam in the FERMI light source generating fully transversely and longitudinally coherent light in the VUV to soft x-ray wavelength regimes. This device is located at the end of the linear accelerator in order to provide the longitudinal phase space nearest to the entrance of the photon-producing beam-lines. Here, we describe the design, fabrication, characterization, commissioning, and operational implementation of this transverse deflecting cavity structure diagnostic system for the high-energy (1.2 GeV) regime

    Optimizing hot electron harvesting at planar metal–semiconductor interfaces with titanium oxynitride thin films

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    Understanding metal-semiconductor interfaces is critical to the advancement of photocatalysis and sub-bandgap solar energy harvesting where electrons in the metal can be excited by sub-bandgap photons and extracted into the semiconductor. In this work, we compare the electron extraction efficiency across Au/TiO2 and titanium oxynitride (TiON)/TiO2-x interfaces, where in the latter case the spontaneously forming oxide layer (TiO2-x) creates a metal-semiconductor contact. Time-resolved pump-probe spectroscopy is used to study the electron recombination rates in both cases. Unlike the nanosecond recombination lifetimes in Au/TiO2, we find a bottleneck in the electron relaxation in the TiON system, which we explain using a trap-mediated recombination model. Using this model, we investigate the tunability of the relaxation dynamics with oxygen content in the parent film. The optimized film (TiO0.5N0.5) exhibits the highest carrier extraction efficiency (NFC ≈ 2.8 × 1019 m-3), slowest trapping, and an appreciable hot electron population reaching the surface oxide (NHE ≈ 1.6 × 1018 m-3). Our results demonstrate the productive role oxygen can play in enhancing electron harvesting and prolonging electron lifetimes, providing an optimized metal-semiconductor interface using only the native oxide of titanium oxynitride

    Dienogest alone or dienogest combined with estrogens in the treatment of ovarian endometriomas, that is the question. A retrospective cohort study

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    Purpose: to compare the effects of Dienogest 2 mg (D) alone or combined with estrogens (D + ethinylestradiol 0.03 mg, D + EE; D + estradiol valerate 1-3 mg, D + EV) in terms of symptoms and endometriotic lesions variations. Methods: This retrospective study included symptomatic patients in reproductive age with ultrasound diagnosis of ovarian endometriomas. Medical therapy for at least 12 months with D, D + EE or D + EV was required. Women were evaluated at baseline visit (V1) and after 6 (V2) and 12 months (V3) of therapy. Results: 297 patients were enrolled (156 in the D group, 58 in the D + EE group, 83 in the D + EV group). Medical treatment leaded to a significant reduction in size of endometriomas after 12 months, with no differences between the three groups. When comparing D and D + EE/D + EV groups, a significant decrease of dysmenorrhea was detected in the D group than in D + EE/D + EV group. Conversely, the reduction of dysuria was more significative in the D + EE/D + EV groups rather than in the D group. Regarding tolerability, treatment associated side effects were reported by 16.2% patients. The most frequent one was uterine bleeding/spotting, significantly higher in the D + EV group. Conclusion: Dienogest alone or associated with estrogens (EE/EV) seems to be equally effective in reducing endometriotic lesions mean diameter. The reduction of dysmenorrhea was more significative when D was administered alone, while dysuria seems to improve more when D is associated with estrogens
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