1,434 research outputs found

    Multilevel Visualisation of Topic Dependency Models for Assessment Design and Delivery: A Hypergraph Based Approach

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    The effective design and delivery of assessments in a wide variety of evolving educational environments remains a challenging problem. Proposals have included the use of learning dashboards, peer learning environments, and grading support systems; these embrace visualisations to summarise and communicate results. In an on-going project, the investigation of graph based visualisation models for assessment design and delivery has yielded promising results. Here, an alternative graph foundation, a two-weighted hypergraph, is considered to represent the assessment material (e.g., questions) and their explicit mapping to one or more learning objective topics. The visualisation approach considers the hypergraph as a collection of levels; the content of these levels can be customized and presented according to user preferences. A case study on generating hypergraph models using commonly available assessment data and a flexible visualisation approach using historical data from an introductory programming course is presentedComment: Published in the proceedings of the 25th International DMS Conference on Visualization and Visual Language

    Field fluctuations near a conducting plate and Casimir-Polder forces in the presence of boundary conditions

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    We consider vacuum fluctuations of the quantum electromagnetic field in the presence of an infinite and perfectly conducting plate. We evaluate how the change of vacuum fluctuations due to the plate modifies the Casimir-Polder potential between two atoms placed near the plate. We use two different methods to evaluate the Casimir-Polder potential in the presence of the plate. They also give new insights on the role of boundary conditions in the Casimir-Polder interatomic potential, as well as indications for possible generalizations to more complicated boundary conditions.Comment: 10 page

    Role of \u3csup\u3e18\u3c/sup\u3eF-FDG PET Scan in Rheumatoid Lung Nodule: Case Report and Review of the Literature

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    Flourine-18 fluoro-2-deoxy-glucose (18F-FDG) positron emission tomography combined with computed tomography (PET/CT) is a useful test for the management of malignant conditions. Inflammatory and infectious processes, however, can cause increased uptake on PET scanning, often causing diagnostic dilemmas. This knowledge is important to the rheumatologist not only because of the inflammatory conditions we treat but also because certain rheumatic diseases impose an increased risk of malignancy either due to the disease itself or as a consequence of medications used to treat the rheumatic diseases. There is an increasing body of evidence investigating the role of PET scans in inflammatory conditions. This paper describes a patient with rheumatoid arthritis who developed pulmonary nodules that showed increased uptake on PET/CT scan and reviews the use of PET scanning in the diagnosis and management of rheumatoid arthritis

    The cosmological implications of a fundamental length: a DSR inspired de-Sitter spacetime

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    We study a de-Sitter model in the framework of a Deformed Special Relativity (DSR) inspired structure. The effects of this framework appear as the existence of a fundamental length which influences the behavior of the scale factor. We show that such a deformation can either be used to control the unbounded growth of the scale factor in the present accelerating phase or account for the inflationary era in the early evolution of the universe.Comment: 10 pages, 3 figures, to appear in JCA

    Correlation effects in bistability at the nanoscale: steady state and beyond

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    The possibility of finding multistability in the density and current of an interacting nanoscale junction coupled to semi-infinite leads is studied at various levels of approximation. The system is driven out of equilibrium by an external bias and the non-equilibrium properties are determined by real-time propagation using both time-dependent density functional theory (TDDFT) and many-body perturbation theory (MBPT). In TDDFT the exchange-correlation effects are described within a recently proposed adiabatic local density approximation (ALDA). In MBPT the electron-electron interaction is incorporated in a many-body self-energy which is then approximated at the Hartree-Fock (HF), second-Born (2B) and GW level. Assuming the existence of a steady-state and solving directly the steady-state equations we find multiple solutions in the HF approximation and within the ALDA. In these cases we investigate if and how these solutions can be reached through time evolution and how to reversibly switch between them. We further show that for the same cases the inclusion of dynamical correlation effects suppresses bistability.Comment: 13 pages, 12 figure

    A multiple-scattering approach to interatomic interactions and superradiance in inhomogeneous dielectrics

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    The dynamics of a collection of resonant atoms embedded inside an inhomogeneous nondispersive and lossless dielectric is described with a dipole Hamiltonian that is based on a canonical quantization theory. The dielectric is described macroscopically by a position-dependent dielectric function and the atoms as microscopic harmonic oscillators. We identify and discuss the role of several types of Green tensors that describe the spatio-temporal propagation of field operators. After integrating out the atomic degrees of freedom, a multiple-scattering formalism emerges in which an exact Lippmann-Schwinger equation for the electric field operator plays a central role. The equation describes atoms as point sources and point scatterers for light. First, single-atom properties are calculated such as position-dependent spontaneous-emission rates as well as differential cross sections for elastic scattering and for resonance fluorescence. Secondly, multi-atom processes are studied. It is shown that the medium modifies both the resonant and the static parts of the dipole-dipole interactions. These interatomic interactions may cause the atoms to scatter and emit light cooperatively. Unlike in free space, differences in position-dependent emission rates and radiative line shifts influence cooperative decay in the dielectric. As a generic example, it is shown that near a partially reflecting plane there is a sharp transition from two-atom superradiance to single-atom emission as the atomic positions are varied.Comment: 18 pages, 4 figures, to appear in Physical Review

    Comparison of the Rey Auditory Verbal Learning Test (RAVLT) and Digit Test among Typically Achieving and Gifted Students

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    How to Cite This Article: Khosravi Fard E, Keelor JL, Akbarzadeh Bagheban AR, Keith RW. Comparison of the RAVLT and Digit Test with Typically Achieving and Gifted Students. Iran J Child Neurol. Spring 2016; 10(2):26-37.AbstractObjectiveIn this study, different kinds of memory were evaluated using Rey Auditory Verbal Learning (RAVLT) test and were compared between two groups of typical and gifted students using Digit Span test. Finally, we determined if working memory interfered with scores in different Rey stages or not.Material & MethodsThis study was conducted in Tehran City, Iran in 2013. Scores on RAVLT were compared with WISC- R digit span results in a sample of 148 male students aged 12-14 yr old divided into two groups including 75 students in typical school (IQ ranging between 90 and 110) and 73 gifted students (IQs ranging between 110 and 130).ResultsGifted students obtained higher scores than typical students in both Forward Digit Span (FDS) and Backward Digit Span (BDS) and all 9 stages of RAVLT comparing with typical students (P<0.001). There was no significant difference between different ages (P> 0.05). The 14 yr old students in both groups had the highest score. There was a high correlation between FDS and the first stage of RAVLT as well as high correlation between BDS and seventh stage of RAVLT.ConclusionIntelligence has effect on better score of memory and gifted subjects had better scores in memory tests, although the intelligence effect in learning was quantitative rather than qualitative. RAVLT is a comprehensive test, which evaluates short-term memory, working memory and long-term memory and besides Digit span test provides precious information about memory and learning of subjects in order to program different student’s educational schedules. References1.C. Gordon Wells. Learning to talk: The pattern of Development. In: C. Gordon Wells, editor. The meaning makers: Children learning language and using language to learn: 1st ed. Heinemann Press 1986.P.22-34. 2.Ackerman PL, Beier ME, Boyle MO. Working memory and intelligence: The same or different constructs? Psychol Bull 2005;131(1):30.3. Spender J-C. Organizational knowledge, learning and memory: three concepts in search of a theory. JOCM 1996;9(1):63-78.4. Wechsler D. Intelligence: Definition, theory, and the IQ. In: Robert Cancro, editor. Intelligence: Genetic and environmental influences. Grune and Stratton Press 1971.P. 34-40.5. Erickson RP. Are Humans the Most Intelligent Species? 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    The Effect of Dust Storm on the Microbial Quality of Ambient Air in Sanandaj: A City Located in the West of Iran.

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    BACKGROUND & AIMS: The presence of pathogenic microorganisms in the dust storm can cause diseases such as Asthma, Pneumonia, and respiratory infections. The aim of this study was to determine the relationship between air-borne particles with airborne microorganisms in normal and dusty days in Sanandaj, a city located in the west of Iran. MATERIALS & METHODS: Air sampling was conducted during the normal and dusty days through Andersen single-stage impactor (28.3 L/min) for 2.5 min. Air particles concentration (PM10) was measured daily and microbial sampling was also conducted on every six days and on the dusty days. Finally, the data was analyzed by SPSS-16 (ANOVA and paired T-tests). RESULTS: The concentration of airborne microorganisms (bacteria and fungi) was increased by an increase of the airborne particles. Particles concentration in May, June and July (twice per month) was more than of the standard value. The predominant species of bacteria and fungi during the occurrence of Dust storm was Bacillus spp. (56.2% of total bacteria) and Mycosporium spp. (28.6% of total fungi), respectively. DISCUSSION AND CONCLUSION: The results showed that the number of airborne microorganisms (bacteria and fungi) increased during the dust storm. Therefore, the microorganisms in the dust storm can cause biological harmful effects on human health

    On the error term in Weyl's law for the Heisenberg manifolds (II)

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    In this paper we study the mean square of the error term in the Weyl's law of an irrational (2l+1)(2l+1)-dimensional Heisenberg manifold . An asymptotic formula is established
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