4,180 research outputs found

    Compatriot and foreigner : a study of impression formation in three countries

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    Caption title"February 5, 1957."At head of title: Communications Program. Experimental Section"350"--handwritten on coverIncludes bibliographical references (leaf 21

    On the behavior of the algebraic transfer

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    Let Tr_k : ��_2 (⊗ over GL_k) PH_i(B��_k) → Ext^(k,k+i)_A(��_2,��_2) be the algebraic transfer, which is defined by W. Singer as an algebraic version of the geometrical transfer tr_k : π_∗^S((B��_k)_+) → π_∗^S(S^0). It has been shown that the algebraic transfer is highly nontrivial and, more precisely, that Tr_k is an isomorphism for k = 1,2,3. However, Singer showed that Tr_5 is not an epimorphism. In this paper, we prove that Tr_4 does not detect the non zero element g_s ∈ Ext^(4,12·2^s)_A(��_2,��_2) for every s ≥ 1. As a consequence, the localized (Sq^0)^(−1)Tr_4 given by inverting the squaring operation Sq^0 is not an epimorphism. This gives a negative answer to a prediction by Minami

    Comparative Direct Analysis of Type Ia Supernova Spectra. IV. Postmaximum

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    A comparative study of optical spectra of Type Ia supernovae (SNe Ia) obtained near 1 week, 3 weeks, and 3 months after maximum light is presented. Most members of the four groups that were defined on the basis of maximum light spectra in Paper II (core normal, broad line, cool, and shallow silicon) develop highly homogeneous postmaximum spectra, although there are interesting exceptions. Comparisons with SYNOW synthetic spectra show that most of the spectral features can be accounted for in a plausible way. The fits show that 3 months after maximum light, when SN Ia spectra are often said to be in the nebular phase and to consist of forbidden emission lines, the spectra actually remain dominated by resonance scattering features of permitted lines, primarily those of Fe II. Even in SN 1991bg, which is said to have made a very early transition to the nebular phase, there is no need to appeal to forbidden lines at 3 weeks postmaximum, and at 3 months postmaximum the only clear identification of a forbidden line is [Ca II] 7291, 7324. Recent studies of SN Ia rates indicate that most of the SNe Ia that have ever occurred have been "prompt" SNe Ia, produced by young (100,000,000 yr) stellar populations, while most of the SNe Ia that occur at low redshift today are "tardy", produced by an older (several Gyrs) population. We suggest that the shallow silicon SNe Ia tend to be the prompt ones.Comment: Accepted by PAS

    Soft X-ray emission lines of Fe XV in solar flare observations and the Chandra spectrum of Capella

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    Recent calculations of atomic data for Fe XV have been used to generate theoretical line ratios involving n = 3-4 transitions in the soft X-ray spectral region (52-83 A), for a wide range of electron temperatures and densities applicable to solar and stellar coronal plasmas. A comparison of these with solar flare observations from a rocket-borne spectrograph (XSST) reveals generally good agreement between theory and experiment. In particular, the 82.76 A emission line in the XSST spectrum is identified, for the first time to our knowledge in an astrophysical source. Most of the Fe XV transitions which are blended have had the species responsible clearly identified, although there remain a few instances where this has not been possible. The line ratio calculations are also compared with a co-added spectrum of Capella obtained with the Chandra satellite, which is probably the highest signal-to-noise observation achieved for a stellar source in the 25-175 A soft X-ray region. Good agreement is found between theory and experiment, indicating that the Fe XV lines are reliably detected in Chandra spectra, and hence may be employed as diagnostics to determine the temperature and/or density of the emitting plasma. However the line blending in the Chandra data is such that individual emission lines are difficult to measure accurately, and fluxes may only be reliably determined via detailed profile fitting of the observations. The co-added Capella spectrum is made available to hopefully encourage further exploration of the soft X-ray region in astronomical sources.Comment: 27 pages, 10 figures, Astrophysical Journal, in pres

    The role of brand loyalty and social media in e-commerce interfaces: survey results and implications for user interfaces

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    This paper explores the role of brand loyalty and social media in e-commerce interfaces. A survey consisting of 118 respondents was contacted to address the questions relating to online shopping and brand loyalty. Link between the frequency of access and time spent on an e-commerce user interface, and brand loyalty, gender and age profile differences, and the role of social media to branding and on-line shopping was analyzed. It was found that online loyalty differs from offline loyalty and loyalty also differed across genders, showing men were more loyal than women when shopping online. Information shared about products on social media by friends and family played an important role in purchase decision making. Website interface and ease of navigation were also key aspects for online shopping. The research concluded with recommendations to create multimodal websites which are more interactive and targeted so customer experience is enhanced and loyalty is achieved through the use of interactivity and social media

    Symmetric Homology of Algebras

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    The symmetric homology of a unital algebra AA over a commutative ground ring kk is defined using derived functors and the symmetric bar construction of Fiedorowicz. For a group ring A=k[Γ]A = k[\Gamma], the symmetric homology is related to stable homotopy theory via HS(k[Γ])H(ΩΩS(BΓ);k)HS_*(k[\Gamma]) \cong H_*(\Omega\Omega^{\infty} S^{\infty}(B\Gamma); k). Two chain complexes that compute HS(A)HS_*(A) are constructed, both making use of a symmetric monoidal category ΔS+\Delta S_+ containing ΔS\Delta S. Two spectral sequences are found that aid in computing symmetric homology. The second spectral sequence is defined in terms of a family of complexes, Sym(p)Sym^{(p)}_*. Sym(p)Sym^{(p)} is isomorphic to the suspension of the cycle-free chessboard complex Ωp+1\Omega_{p+1} of Vre\'{c}ica and \v{Z}ivaljevi\'{c}, and so recent results on the connectivity of Ωn\Omega_n imply finite-dimensionality of the symmetric homology groups of finite-dimensional algebras. Some results about the kΣp+1k\Sigma_{p+1}--module structure of Sym(p)Sym^{(p)} are devloped. A partial resolution is found that allows computation of HS1(A)HS_1(A) for finite-dimensional AA and some concrete computations are included.Comment: This is a major revision of the previous pape

    Employing culturally responsive pedagogy to foster literacy learning in schools

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     In recent years it has become increasingly obvious that, to enable students in schools from an increasingly diverse range of cultural backgrounds to acquire literacy to a standard that will support them to achieve academically, it is important to adopt pedagogy that is responsive to, and respectful of, them as culturally situated. What largely has been omitted from the literature, however, is discussion of a relevant model of learning to underpin this approach. For this reason this paper adopts a socio-cultural lens (Vygotsky, 1978) through which to view such pedagogy and refers to a number of seminal texts to justify of its relevance. Use of this lens is seen as having a particular rationale. It forces a focus on the agency of the teacher as a mediator of learning who needs to acknowledge the learner’s cultural situatedness (Kozulin, 2003) if school literacy learning for all students is to be as successful as it might be. It also focuses attention on the predominant value systems and social practices that characterize the school settings in which students’ literacy learning is acquired. The paper discusses implications for policy and practice at whole-school, classroom and individual student levels of culturally-responsive pedagogy that is based on a socio-cultural model of learning. In doing so it draws on illustrations from the work of a number of researchers, including that of the author

    Shareholder Protection: A Comparative Review of the Corporate Legal / Regulatory Regimes in the UK and Nigeria

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    Foreign investment is a major source of the capital that Nigeria and other developing markets need to promote economic activities and drive economic development. While profit mainly drives the decision to invest abroad, such decisions are also influenced by the safety of any actual investments made. Thus, investors are interested in the laws and regulations that offer them protection against corporate insider opportunism. In Nigeria, the relationship between corporate actors is mainly regulated by the Companies and Allied Matters Act (CAMA). This article investigates the corporate legal and regulatory protection for corporate shareholders in Nigeria and the UK. Comparing the corporate regulatory regime in the two jurisdictions, this article argues that the identified weaknesses in the Nigerian regulatory framework negatively impact the growth of foreign investment in the country. In view of these weaknesses, the article suggests a major review of CAMA and other regulatory instruments with a view to addressing the protection of small investors and “outsiders”, such as foreign investors
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