979 research outputs found

    The Dramatization of Children Literature Books for the Development of the Second/Foreign Language: An Implementation of a Drama-Based Project to Students of Primary School

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    This paper presents and outlines the design and implementation of a pilot program based on activities of dramatization of children literary books aiming at developing language skills of primary school students in English as a foreign language, participating in interactive, drama play and creative activities This project was implemented to students of the fifth grade of primary schools of Larissa (Greece) in a sample of 15 students. The collaboration, creativity, and the engagement with English literature were the main features of the program. The learning environment of the program was either the municipal center of creativity “Kalikatzoura Pasalidou” or the municipal gym. When the center of creativity was the place of learning, students analyzed the English children’s literature books, achieving the acquisition of the new vocabulary and participating in creative writing activities. When the municipal gym was the place of instruction, students participated in activities of performing theatrical plays developing spoken language and intonation of the words. The evaluation and feasibility of the program has been realized through a) a pre- and a post - test and b) by keeping a Journal by the teacher. It became so obvious that the particular application had a beneficial effect on the development of speaking and writing skills of learners and enhanced their motivation to participate in drama activities

    Some properties of the "String gas" with the equation of state p=−ρ/3p = -\rho/3

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    We show that the string gas - a perfect fluid with the equation of state p=−13ρp = -\frac13 \rho possesses rather interesing properties. In Friedmann universes its presence can can change the observable topology of the space; in the spherically symmetric spacetimes it produces rather bizzare geometries and in a way its influence on the rotation curves mimics the dark matter effects.Comment: 9 pages, 1 figur

    Complexity and hierarchical game of life

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    Hierarchical structure is an essential part of complexity, important notion relevant for a wide range of applications ranging from biological population dynamics through robotics to social sciences. In this paper we propose a simple cellular-automata tool for study of hierarchical population dynamics

    Thermoelastic Properties of Ringwoodite [Fe_x,Mg_(1-x)]_2SiO_4: Its Relationship to the 520 km Seismic Discontinuity

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    We combine density functional theory (DFT) within the local density approximation (LDA), the quasiharmonic approximation (QHA), and a model vibrational density of states (VDoS) to calculate elastic moduli and sound velocities of gamma-[Fe_x,Mg_(1-x)]_2SiO_4 (ringwoodite), the most abundant mineral of the lower Earth's transition zone (TZ). Comparison with experimental values at room-temperature and high pressure or ambient-pressure and high temperature shows good agreement with our first-principles findings. Then, we investigate the contrasts associated with the beta-to-gamma-[Fe_x,Mg_(1-x)]_2SiO_4 transformation at pressures and temperatures relevant to the TZ. This information offers clearly defined reference values to advance the understanding of the nature of the 520 km seismic discontinuity.Comment: 29 pages, 6 figures, 2 tables. Under Revie

    Why latrines are not used : communities' perceptions and practices regarding latrines in a Taenia solium endemic rural area in Eastern Zambia

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    Taenia solium cysticercosis is a neglected parasitic zoonosis occurring in many developing countries. Socio-cultural determinants related to its control remain unclear. Studies in Africa have shown that the underuse of sanitary facilities and the widespread occurrence of free-roaming pigs are the major risk factors for porcine cysticercosis. The study objective was to assess the communities' perceptions, practices and knowledge regarding latrines in a T. solium endemic rural area in Eastern Zambia inhabited by the Nsenga ethno-linguistic group, and to identify possible barriers to their construction and use. A total of 21 focus group discussions on latrine use were organized separately with men, women and children, in seven villages of the Petauke district. The themes covered were related to perceived latrine availability (absence-presence, building obstacles) and perceived latrine use (defecation practices, latrine management, socio-cultural constraints). The findings reveal that latrines were not constructed in every household because of the convenient use of existing latrines in the neighborhood. Latrines were perceived to contribute to good hygiene mainly because they prevent pigs from eating human feces. Men expressed reluctance to abandon the open-air defecation practice mainly because of toilet-associated taboos with in-laws and grown-up children of the opposite gender. When reviewing conceptual frameworks of people's approach to sanitation, we found that seeking privacy and taboos hindering latrine use and construction were mainly explained in our study area by the fact that the Nsenga observe a traditionally matrilineal descent. These findings indicate that in this local context latrine promotion messages should not only focus on health benefits in general. Since only men were responsible for building latrines and mostly men preferred open defecation, sanitation programs should also be directed to men and address related sanitary taboos in order to be effective

    A Pebbling Game on Powers of Paths

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    Two Player Graph Pebbling is an extension of graph pebbling. Players Mover and Defender use pebbling moves, the act of removing two pebbles from one vertex and placing one pebble on an adjacent vertex, to win. If a specified vertex has a pebble on it, then Mover wins. If a specified vertex is pebble-free and there are no more valid pebbling moves, then Defender wins. The Two-Player Pebbling Number of a graph G, η(G), is the minimum m such that for every arrangement of m pebbles and for any specified vertex, Mover can win. We specify the winning player for powers of a path

    Mid-J CO Emission in Nearby Seyfert Galaxies

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    We study for the first time the complete sub-millimeter spectra (450 GHz to 1550 GHz) of a sample of nearby active galaxies observed with the SPIRE Fourier Transform Spectrometer (SPIRE/FTS) onboard Herschel. The CO ladder (from Jup = 4 to 12) is the most prominent spectral feature in this range. These CO lines probe warm molecular gas that can be heated by ultraviolet photons, shocks, or X-rays originated in the active galactic nucleus or in young star-forming regions. In these proceedings we investigate the physical origin of the CO emission using the averaged CO spectral line energy distribution (SLED) of six Seyfert galaxies. We use a radiative transfer model assuming an isothermal homogeneous medium to estimate the molecular gas conditions. We also compare this CO SLED with the predictions of photon and X-ray dominated region (PDR and XDR) models.Comment: Proceedings of the Torus Workshop 2012 held at the University of Texas at San Antonio, 5-7 December 2012. C. Packham, R. Mason, and A. Alonso-Herrero (eds.); 6 pages, 3 figure

    Emission-Line Properties of z > 4 Quasars

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    We present results of a program of high signal-to-noise spectroscopy for 44 QSOs at redshifts > 4 using the MMT and Keck observatories. The quasar spectra cover 1100 -- 1700 A in the rest frame for sources spanning a luminosity range of approximately 2 orders of magnitude. Comparisons between these data and spectra of lower redshift quasars reveal a high degree of similarity, although differences are present in the profiles and the strengths of some emission features. An examination of the luminosity dependence of the emission lines reveals evidence for a weak or absent Baldwin effect among z > 4 QSOs. We compare measurements for objects in our sample with results from other high redshift surveys characterized by different selection techniques. Distributions of equivalent widths for these different ensembles are consistent with a common parent population, suggesting that our sample is not strongly biased, or in any case, subject to selection effects that are not significantly different from other surveys, including the Sloan Digital Sky Survey. Based on this comparison, we tentatively conclude that the trends identified here are representative of high z QSOs. In particular, the data bolster indications of supersolar metallicities in these luminous, high-z sources, which support scenarios that assume substantial star formation at epochs preceding or concurrent with the QSO phenomena.Comment: 26 pages (incl. 9 figures), AASTeX v5.0, to appear in The Astrophysical Journa

    The decay of quadrupole-octupole 1−1^- states in 40^{40}Ca and 140^{140}Ce

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    Background: Two-phonon excitations originating from the coupling of two collective one-phonon states are of great interest in nuclear structure physics. One possibility to generate low-lying E1E1 excitations is the coupling of quadrupole and octupole phonons. Purpose: In this work, the Îł\gamma-decay behavior of candidates for the (21+⊗31−)1−(2_1^+\otimes 3_1^-)_{1^-} state in the doubly-magic nucleus 40^{40}Ca and in the heavier and semi-magic nucleus 140^{140}Ce is investigated. Methods: (γ⃗,Îłâ€Č)(\vec{\gamma},\gamma') experiments have been carried out at the High Intensity Îł\gamma-ray Source (HIÎł{\gamma}S) facility in combination with the high-efficiency Îł\gamma-ray spectroscopy setup Îł3\gamma^3 consisting of HPGe and LaBr3_3 detectors. The setup enables the acquisition of Îł\gamma-Îł\gamma coincidence data and, hence, the detection of direct decay paths. Results: In addition to the known ground-state decays, for 40^{40}Ca the decay into the 31−3^-_1 state was observed, while for 140^{140}Ce the direct decays into the 21+2^+_1 and the 02+0^+_2 state were detected. The experimentally deduced transition strengths and excitation energies are compared to theoretical calculations in the framework of EDF theory plus QPM approach and systematically analyzed for N=82N=82 isotones. In addition, negative parities for two J=1J=1 states in 44^{44}Ca were deduced simultaneously. Conclusions: The experimental findings together with the theoretical calculations support the two-phonon character of the 11−1^-_1 excitation in the light-to-medium-mass nucleus 40^{40}Ca as well as in the stable even-even N=82N=82 nuclei.Comment: 11 pages, 6 figures, as accepted in Phys. Rev.
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