758 research outputs found

    Approaching mythology in the history curriculum of compulsory education in Greece

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    Myth can be a first step in historicizing the past and at the same time in appreciating ancient cultures and developing the essential skill of empathy. A main objective of the history curriculum for the third grade of primary school in Greece is for children at 8 and 9 years old to familiarize themselves with the basic cultural elements of the origins of Greek, European and global civilization. Ancient Greek myths are taught using references and links to the myths of other peoples and cultures, and by identifying similarities and differences in the interpretation of the world within the framework of a multi-perspective, intercultural approach. Myths also depict the relationship between man and nature. They constitute man’s attempt to interpret the physical and social environment. In addition, myths present the relationship between man and the divine in the early stages of cultural evolution, and at the same time provide evidence of the culture of a historical period. Pupils become aware of the fact that myths used to have a symbolic and ritualistic function, which aimed to initiate younger members into the acceptable practices and values of their community. Myths provided meaningful models of action (exempla) through their allegorical nature. Moreover, myths facilitate the analysis of human behaviour by introducing the schema of cause and effect. Mythical thought seeks to understand causality, which is also the primary aim of science. In this sense, mythical discourse is connected to scientific discourse. Within the framework of a methodological approach based on these theoretical assumptions, this paper also includes a presentation of educational activities and pupils’ perceptions as part of a survey conducted in a third-grade primary school class in Greece

    Charging and Discharging Processes in AlN Dielectric Films Deposited by Plasma Assisted Molecular Beam Epitaxy

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    In the present work the electrical properties of AlN polycrystalline films deposited at low temperatures by plasma-assisted molecular beam epitaxy (PA-MBE) are investigated. The polarization build-up during constant current injection as well as the depolarization process after the current stress have been investigated through monitoring voltage transients in Metal – Insulator – Metal (MIM) capacitors, in temperature range from 300 K to 400 K. Moreover, current – voltage characteristics obtained at different temperatures revealed that charge collection at low fields in these films occurs through variable range hopping

    Properties of contactless and contacted charging in MEMS capacitive switches

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    The dielectric charging in MEMS capacitive switches is a complex effect. The high electric field during pull-down causes intrinsic free charge migration and dipole orientation as well as charge injection. The macroscopic dipole moment of the first two mechanisms is opposite to the one arising from charge injection. This causes partial compensation hence mitigates the overall charging and increases the device lifetime. The charging due to intrinsic free charge migration and dipole orientation can be monitored under contactless electric field application in the pull-up state. The paper investigates the characteristics of contactless charging and compares them with the ones of contacted charging. The characteristics of the discharging process that follows each charging procedure are also presented

    ρ\rho - nucleus bound states in Walecka model

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    Possible formation of ρ\rho nucleus bound state is studied in the framework of Walecka model. The bound states are found in different nuclei ranging from 3He^3He to 208Pb^{208}Pb. These bound states may have a direct bearing on the recent experiments on the photoproduction of ρ\rho meson in the nuclear medium.Comment: RevTeX fil

    Subthreshold rho^0 photoproduction on 3He

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    A large reduction of the rho^0 mass in the nuclear medium is reported, inferred from dipion photoproduction spectra in the 1 GeV region, for the reaction 3He(gamma,pi+ pi-)X with a 10% duty factor tagged-photon beam and the TAGX multi-particle spectrometer. The energy range covered (800 < E(gamma) < 1120 MeV) lies mostly below the free rho^0 production threshold, a region which is believed sensitive to modifications of light vector-meson properties at nuclear-matter densities. The rho^0 masses extracted from the MC fitting of the data, m*(rho^0) = 642 +/- 40, 669 +/- 32, and 682 +/- 56 MeV/c^2 for E(gamma) in the 800-880, 880-960, and 960-1040 MeV regions respectively, are independently corroborated by a measured, assumption-free, kinematical observable. This mass shift, far exceeding current mean-field driven theoretical predictions, may be suggestive of rho^0 decay within the range of the nucleonic field.Comment: 40 pages, 13 figures, submitted to Phys. Rev.

    Prevalence and Predictors of Vitamin D Insufficiency in Children: A Great Britain Population Based Study

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    Objectives To evaluate the prevalence and predictors of vitamin D insufficiency (VDI) in children In Great Britain. Design A nationally representative cross-sectional study survey of children (1102) aged 4–18 years (999 white, 570 male) living in private households (January 1997–1998). Interventions provided information about dietary habits, physical activity, socio-demographics, and blood sample. Outcome measures were vitamin D insufficiency (<50 nmol/L). Results Vitamin D levels (mean = 62.1 nmol/L, 95%CI 60.4–63.7) were insufficient in 35%, and decreased with age in both sexes (p<0.001). Young People living between 53–59 degrees latitude had lower levels (compared with 50–53 degrees, p = 0.045). Dietary intake and gender had no effect on vitamin D status. A logistic regression model showed increased risk of VDI in the following: adolescents (14–18 years old), odds ratio (OR) = 3.6 (95%CI 1.8–7.2) compared with younger children (4–8 years); non white children (OR = 37 [95%CI 15–90]); blood levels taken December-May (OR = 6.5 [95%CI 4.3–10.1]); on income support (OR = 2.2 [95%CI 1.3–3.9]); not taking vitamin D supplementation (OR = 3.7 [95%CI 1.4–9.8]); being overweight (OR 1.6 [95%CI 1.0–2.5]); <1/2 hour outdoor exercise/day/week (OR = 1.5 [95%CI 1.0–2.3]); watched >2.5 hours of TV/day/week (OR = 1.6[95%CI 1.0–2.4]). Conclusion We confirm a previously under-recognised risk of VDI in adolescents. The marked higher risk for VDI in non-white children suggests they should be targeted in any preventative strategies. The association of higher risk of VDI among children who exercised less outdoors, watched more TV and were overweight highlights potentially modifiable risk factors. Clearer guidelines and an increased awareness especially in adolescents are needed, as there are no recommendations for vitamin D supplementation in older children
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