Investigations of excitation energy transfer and intramolecular interactions in a nitrogen corded distrylbenzene dendrimer system.

The photophysics of an amino-styrylbenzene dendrimer (A-DSB) system is probed by time-resolved and steady state luminescence spectroscopy. For two different generations of this dendrimer, steady state absorption, emission, and photoluminescence excitation spectra are reported and show that the efficiency of energy transfer from the dendrons to the core is very close to 100%. Ultrafast time-resolved fluorescence measurements at a range of excitation and detection wavelengths suggest rapid (and hence efficient) energy transfer from the dendron to the core. Ultrafast fluorescence anisotropy decay for different dendrimer generations is described in order to probe the energy migration processes. A femtosecond time-scale fluorescence depolarization was observed with the zero and second generation dendrimers. Energy transfer process from the dendrons to the core can be described by a Förster mechanism (hopping dynamics) while the interbranch interaction in A-DSB core was found to be very strong indicating the crossover to exciton dynamics

The me in memory:the role of the self in autobiographical memory development

This paper tests the hypothesis that self development plays a role in the offset of childhood amnesia; assessing the importance of both the capacity to anchor a memory to the self-concept, and the strength of the self-concept as an anchor. We demonstrate for the first time that the volume of 3- to 6-year-old’s specific autobiographical memories is predicted by both the volume of their self-knowledge, and their capacity for self-source monitoring within self-referencing paradigms (N =186). Moreover, there is a bidirectional relationship between self and memory, such that autobiographical memory mediates the link between self-source monitoring and self-knowledge. These predictive relationships suggests that the self memory system is active in early childhood

The poetic is political….and other notes on engaged scholarship

Instrumental and objectivist logics maintain a hegemonic place in Western scholarship, reasoning skills powerfully equipped to address certain dilemmas even as they may obscure other ways of knowing. In this chapter, we enlarge dominant notions of rationality by offering an aesthetic view of knowledge as vital for engaged communication scholarship. Our interest in aesthetic logics parallels concerns that have led scholars to develop feminist practices of inquiry (e.g., Harding, 1998; Hesse-Biber, 2007), interrogate the aesthetics of representations in West-centric knowledge structures from postcolonial and Subaltern Studies standpoints (e.g., Broadfoot & Munshi, 2007; Dutta, 2007, 2008), focus on autoethnographic and poetic accounts ( e.g., Carr, 2003; Ellingson, 2009), introduce reflexivity and the politics of personhood in the scholarly process ( e.g., Harding, 1991; Reinharz, 1992), and adopt narrative and dialogic understandings of knowledge constructions (e.g., Frank, 2005; Harter, 2005). Loosely coupled, these research trajectories advance alternative rationalities for witnessing and answering salient social issues. We argue for the theoretical and practical incorporation of aesthetic rationalities in engaged scholarship-logics of poss ibility that cultivate individuals \u27 capacities to imagine otherwise. Reimagining scholarly inquiry to reflect and embrace aesthetic logics requires us to rethink our methods of data collection, analysis, and representation and our own roles as researchers and writers . When we resist the art/science dichotomy, opportunities abound for sensemaking and representation that embody aesthetic ways of knowing. Furthermore, rejection of dichotomous thinking opens up possibilities for listening to ways of knowing that lie beyond the realm of Eurocentric knowledge structures (Dutta, in press). Even after the interpretive turn, instrumental and objectivist logics often underlie and sometimes constrain the processes and products of social scientific research (Denzin & Lincoln, 2005). Traditional structures and modes of research offer important but limited conceptualizations of knowing. We can open ourselves to other ways of asking questions that include overt attention to aesthetic sensibilities . We need not reject or abandon traditional modes of research. Instead, we can enlarge the realm of possibilities for what counts as accepted research practices and advance methods for studying the aesthetic nature of communal life (Ellingson, 2009). In this chapter, we develop an understanding of rationality that incorporates imagination, and we explore methodologies that draw on creative sensibilities. We then articul ate the salience of creativity for rendering credible previously subjugated voices, and we articulate its value for engaged communication theory and research

J.S. Harter K1862 Photo Album

https://digital.kenyon.edu/scrapbooks/1061/thumbnail.jp

Probabilistic models of information retrieval based on measuring the divergence from randomness

We introduce and create a framework for deriving probabilistic models of Information Retrieval. The models are nonparametric models of IR obtained in the language model approach. We derive term-weighting models by measuring the divergence of the actual term distribution from that obtained under a random process. Among the random processes we study the binomial distribution and Bose--Einstein statistics. We define two types of term frequency normalization for tuning term weights in the document--query matching process. The first normalization assumes that documents have the same length and measures the information gain with the observed term once it has been accepted as a good descriptor of the observed document. The second normalization is related to the document length and to other statistics. These two normalization methods are applied to the basic models in succession to obtain weighting formulae. Results show that our framework produces different nonparametric models forming baseline alternatives to the standard tf-idf model

Architecture of coatomer: Molecular characterization of delta-COP and protein interactions within the complex

Copyright © 2011 by The Rockefeller University Press.Coatomer is a cytosolic protein complex that forms the coat of COP I-coated transport vesicles. In our attempt to analyze the physical and functional interactions between its seven subunits (coat proteins, [COPs] alpha-zeta), we engaged in a program to clone and characterize the individual coatomer subunits. We have now cloned, sequenced, and overexpressed bovine alpha-COP, the 135-kD subunit of coatomer as well as delta-COP, the 57-kD subunit and have identified a yeast homolog of delta-COP by cDNA sequence comparison and by NH2-terminal peptide sequencing. delta-COP shows homologies to subunits of the clathrin adaptor complexes AP1 and AP2. We show that in Golgi-enriched membrane fractions, the protein is predominantly found in COP I-coated transport vesicles and in the budding regions of the Golgi membranes. A knock-out of the delta-COP gene in yeast is lethal. Immunoprecipitation, as well as analysis exploiting the two-hybrid system in a complete COP screen, showed physical interactions between alpha- and epsilon-COPs and between beta- and delta-COPs. Moreover, the two-hybrid system indicates interactions between gamma- and zeta-COPs as well as between alpha- and beta' COPs. We propose that these interactions reflect in vivo associations of those subunits and thus play a functional role in the assembly of coatomer and/or serve to maintain the molecular architecture of the complex.This work was supported by The Deutsche Forschungsgemeinschaft (SFB 352), the Human Frontier Science Program, and the Swiss National Science Foundation No. 31-43366.95

‘My favourite things to do’ and ‘my favourite people’: Exploring salient aspects of children’s self-concept

This study explores the potential of the ‘draw-and-write’ method for inviting children to communicate salient aspects of their self-concept. Irish primary school children aged 10–13 years drew and wrote about their favourite people and things to do (social and active self). Children drew and described many salient activities (39 in total) and people – including pets. Results suggest that widely used, adult-constructed self-esteem scales for children, while multidimensional, are limited, and that ‘draw-and-write’ is an effective multimodal method with which children can express their social and active self-concepts

Antiferromagnetic correlations and impurity broadening of NMR linewidths in cuprate superconductors

We study a model of a d-wave superconductor with strong potential scatterers in the presence of antiferromagnetic correlations and apply it to experimental nuclear magnetic resonance (NMR) results on Zn impurities in the superconducting state of YBCO. We then focus on the contribution of impurity-induced paramagnetic moments, with Hubbard correlations in the host system accounted for in Hartree approximation. We show that local magnetism around individual impurities broadens the line, but quasiparticle interference between impurity states plays an important role in smearing out impurity satellite peaks. The model, together with estimates of vortex lattice effects, provides a semi-quantitative description of the impurity concentration dependence of the NMR line shape in the superconducting state, and gives a qualitative description of the temperature dependence of the line asymmetry. We argue that impurity-induced paramagnetism and resonant local density of states effects are both necessary to explain existing experiments.Comment: 15 pages, 23 figures, submitted to Phys. Rev.

Who I Am: The Meaning of Early Adolescents’ Most Valued Activities and Relationships, and Implications for Self-Concept Research

Self-concept research in early adolescence typically measures young people’s self-perceptions of competence in specific, adult-defined domains. However, studies have rarely explored young people’s own views of valued self-concept factors and their meanings. For two major self domains, the active and the social self, this mixed-methods study identified factors valued most by 526 young people from socioeconomically diverse backgrounds in Ireland (10-12 years), and explored the meanings associated with these in a stratified subsample (n = 99). Findings indicate that self-concept scales for early adolescence omit active and social self factors and meanings valued by young people, raising questions about content validity of scales in these domains. Findings also suggest scales may under-represent girls’ active and social selves; focus too much on some school-based competencies; and, in omitting intrinsically salient self domains and meanings, may focus more on contingent (extrinsic) rather than true (intrinsic) self-esteem