Is HBT really puzzling?

Two-particle correlations from RHIC have provided a surprising snapshot of the final state at RHIC. In this talk I discuss the nature of the HBT puzzle and attempt to delineate several factors which might ultimately resolve the issue.Comment: Proceedings for WPCF, Kromeriz, Czech Republic, August 200

Frightening web sights: imagery and its characteristics in spider phobia

Objectives: The objective of this study was to investigate how the characteristics of self-generated and spontaneous images might differ between states of high and low anxiety, as observed in spider phobia. It was not known whether self-generated images could be used, in the same way as spontaneous images, to access core beliefs. The frequency and characteristics of spontaneous images were assessed to determine whether they are negative, recurrent, and link to early memories, as have been reported in social phobia. Design: Participants were recruited into either a spider-anxious group or a control group based upon their response (independent variable) to the Fear of Spiders Questionnaire (Muris & Mercklebach, 1996). A semi-structured interview, incorporating a within and between group design, required participants to rate the characteristics (the dependent variables) of self generated and spontaneous images. Method: A semi-structured interview was administered. Participants rated the characteristics of two images (spider and butterfly) using visual analogue scales. The downward arrow technique was used to access core beliefs associated with the self-generated and spontaneous images. Results: The spider-anxious group's spider image was more vivid, evoked more anxiety, and was perceived as having more intent than both control images. The spider-anxious group reported more negative core beliefs associated with the self-generated image and more spontaneous images, that were recurrent, negative and that linked to early traumatic experiences. Conclusions: The phenomenological characteristics of self-generated images can be reliably assessed and, in the absence of spontaneous images, can be utilised to access core beliefs in anxiety disorders. This study provides some evidence of cognitive biases and thinking errors and calls for a new cognitive model of specific phobia

A Narrative Case Study Examining the Influences of Peer-led Team Learning on Student Critical Thinking Skill Acquisition and Deeper Process Content Knowledge in a Midsize Texas University Humanities and Social Sciences Program

This dissertation will examine the efficacy of peer-led team learning (PLTL) in a humanities and social sciences program, at a midsize Texas university. It will be conducted exclusively within the College of Humanities and Social Sciences (CHSS), and the academic subjects to be evaluated include English, history, and philosophy. Its primary function is to disclose whether or not PLTL facilitates in student participants improvement in critical thinking skill acquisition and deeper process content knowledge. Of primary interest in this qualitative, narrative case study is deducing how breakout sessions – supplementary meetings led by student participants, in the absence of instructors, designed to enhance classroom instruction – aid in concept synthesis and retention. Of equal importance is evaluating how the implementation of a PLTL instructional framework cultivates in its participants the acuity necessary to demonstrate that positive learning outcomes are occurring, or have the potential to occur; thereafter, collected data, in the form of participant and instructor narratives derived from questionnaires, interviews, researcher observations, writing samples, and essay-based examinations will support or refute whether improvement in critical thinking skill acquisition and deeper process content knowledge is evident in student participants. Keywords: Peer-led Team Learning (PLTL), Critical Thinking Skill Acquisition, Deeper Process Content Knowledge, Positive Learning Outcomes, Humanities and Social Sciences, Qualitative, Narrative, Case Stud

Studies of long range order and excitations in the iron arsenide superconductors

The study of iron based superconductors began in 2006 when the compound LaOFeP was found to have a superconducting transition at a modest temperature Tc of 3.2 K. Because elemental iron is a strong ferromagnet, this discovery was a great surprise due to the fact that magnetic moments are generally associated with magnetic pair breaking. Soon after this discovery, variations of these superconductors were made through chemical substitutions and the Tc rose to 55 K two years later. The explosion of research that has followed these discoveries has led to the synthesis of several families of iron based superconductors whose high values of Tc are second only to the cuprates and which bringing them into the field of high temperature superconductivity (SC). This thesis focuses on how pressure and electron doping effect the crystallographic and magnetic properties of the iron based superconductors (Ca,Ba)Fe2 As2 which are part of a group of compounds known as 122s. Upon cooling, these compounds undergo a dual structural-magnetic transition from a tetragonal paramagnetic state to an orthorhombic and antiferromagnetic state. By tuning the pressure or dopant concentration knob, we have been able to show clearly that this has the effect of suppressing the magnetism and associated structural transition observed in un-doped or ambient pressure compounds. Neutron scattering measurements on CaFe2 As2 under pressure have demonstrated that the onset of superconductivity is observed after the stabilization of the room-temperature tetragonal phase at low temperatures under non-hydrostatic pressure. For the case of electron doping BaFe2 As2, it is clear that a sufficient suppression of structural and magnetic ordering transitions is necessary for the appearance and optimization of superconductivity. These studies have provided key information about the static magnetic ordering and the associated magnetic excitations, and have allowed for the attempt to address questions about the nature of magnetism in these materials and what role magnetism plays in the appearance of superconductivity

Changes in benthic ecosystem properties and functions across sedimentary gradients in estuaries

In estuaries, sediment properties dominate the inhabiting flora and fauna and their role in energy flows and nutrient cycling. Whilst sediment transport is a natural, key process, human intervention in estuaries and their catchments has altered the regime of terrigenous sediment loading and pose both short and long-term consequences to ecosystem functioning. Temporary increases in turbidity reduce light availability for primary production by microphytobenthos (MPB) that fuel benthic communities. Long-term alteration of grain size properties changes the distribution of key macrofaunal species and how they interact with their environment, carrying potentially serious implications for the ecological functioning of these systems. Our knowledge of how benthic ecosystems respond to changes in sedimentary regimes is crucial to our ability to project and manage the impacts of environmental change. In this thesis, I investigated the multifaceted effects of increased sediment loading on the benthic biota and their functioning using natural and experimental sedimentary gradients. An in situ experiment was conducted on an intertidal sandflat to examine the effects of short-term increases in suspended sediment concentration (SSC) on benthic autotrophic (primary production) and heterotrophic processes. In sunlit conditions, increases in SSC led to dramatic declines in net primary production and concomitant increases in NH₄⁺ efflux from the sediment to the water column. Although sediment chlorophyll-⍺ concentration increased with higher levels of SSC, a result that was likely a photoadaptive response to reduced light intensity, SSC reduced O₂ production per unit of chlorophyll -⍺ . SSC had no significant effect on sediment properties or heterotrophic processes such as sediment oxygen consumption or nutrient efflux, suggesting that temporary increases in suspended sediments (within the range of SSC tested) primarily affected photosynthetic processes. Sediment properties, macrofaunal diversity and biogeochemical fluxes were measured across natural gradients of silt and clay (hereafter mud) to determine the effects of habitat change associated with chronic sediment loading on the structure and functioning of benthic communities. There were significant declines in measures of macrofaunal diversity and the maximum densities of key bioturbating bivalves (Austrovenus stutchburyi and Macomona liliana) with increased mud content. Concurrently, the maximum rates of sediment oxygen consumption (SOC), NH₄⁺ efflux (a proxy of nutrient regeneration)and biomass standardised gross primary production (GPPChl-⍺) also decreased with increasing mud content. A. stutchburyi contributed disproportionately to variation in SOC and NH₄⁺ efflux, suggesting that losses of strongly interacting key species concomitant with increased sediment mud content could have a significant impact on ecosystem function. The results from this study demonstrate the significant loss of ecosystem function in intertidal sandflats that is likely from increased sediment mud content associated with long-term increases in sedimentation stress. The spatial distributions of MPB biomass, macrofaunal grazer abundances and deposit feeding activity were measured across a gradient of sediment mud content to determine relationships between grazers and MPB biomass across transitional sedimentary environments. The density of feeding traces produced by M. Liliana was measured as a proxy of deposit feeding activity by this species. MPB biomass was generally lower in areas with higher deposit feeding activity but this relationship was scale dependent, emerging over larger areas (tens of centimetres) but absent at local (centimetre) scales relative to the animal’s feeding ambit. Despite higher MPB biomass in muddy sediments, feeding trace density was markedly lower, suggesting lower feeding activity and trophic exchange in muddy compared with sandy sediments. The suspension feeding bivalve A. stutchburyi was positively associated with MPB biomass and the interaction between A. stutchburyi density and mud was the strongest predictor of MPB biomass. Thus, non-trophic interactions that potentially facilitate production may override the deleterious effects of grazing on MPB biomass by large macrofaunal species. This thesis demonstrates the high capacity of sandflat systems for primary, secondary production and nutrient regeneration and the degradation of these ecological properties and functions in muddier and more turbid systems. The decline in this functional capacity reflects the alterations of multiple ecological components and their interactions corresponding to habitat change. Defining changes in these interaction networks can improve our ability to track changes in ecosystem functioning and elucidate underlying pathways and potential mechanisms. In particular, this thesis highlights the value of observing changes in these ecological properties and functions across natural and experimental gradients at the appropriate scales in time and space over which stressors operate

An Analytical Framework for Cross-Cultural Studies of Teaching

Working cross-culturally, whether defined by discipline, institution, community, or nation-state, inherently means working outside the familiar. The aim of this paper is to present an analytical framework through which to explore and understand different conceptions of teaching. The framework consists of three analytical categories: epistemic beliefs, normative expectations, and pedagogical procedures

A Narrative Case Study Examining the Influences of Peer-led Team Learning on Student Critical Thinking Skill Acquisition and Deeper Process Content Knowledge in a Midsize Texas University Humanities and Social Sciences Program

This dissertation will examine the efficacy of peer-led team learning (PLTL) in a humanities and social sciences program, at a midsize Texas university. It will be conducted exclusively within the College of Humanities and Social Sciences (CHSS), and the academic subjects to be evaluated include English, history, and philosophy. Its primary function is to disclose whether or not PLTL facilitates in student participants improvement in critical thinking skill acquisition and deeper process content knowledge. Of primary interest in this qualitative, narrative case study is deducing how breakout sessions – supplementary meetings led by student participants, in the absence of instructors, designed to enhance classroom instruction – aid in concept synthesis and retention. Of equal importance is evaluating how the implementation of a PLTL instructional framework cultivates in its participants the acuity necessary to demonstrate that positive learning outcomes are occurring, or have the potential to occur; thereafter, collected data, in the form of participant and instructor narratives derived from questionnaires, interviews, researcher observations, writing samples, and essay-based examinations will support or refute whether improvement in critical thinking skill acquisition and deeper process content knowledge is evident in student participants. Keywords: Peer-led Team Learning (PLTL), Critical Thinking Skill Acquisition, Deeper Process Content Knowledge, Positive Learning Outcomes, Humanities and Social Sciences, Qualitative, Narrative, Case Stud

Cyclophilin-A is bound to through its peptidylprolyl isomerase domain to the cytoplasmic dynein motor protein complex

Although cyclophilin A (CyP-A) is a relatively abundant small immunophilin present in the cytoplasm of all mammalian cells, its general function(s) in the absence of the immunosuppressant drug cyclosporin A is not known. In contrast, the high molecular weight hsp90-binding immunophilins appear to play a role in protein trafficking in that they have been shown to link glucocorticoid receptor-hsp90 and p53.hsp90 complexes to the dynein motor protein for retrograde movement along microtubules. These immunophilins link to cytoplasmic dynein indirectly through the association of the immunophilin peptidylprolyl isomerase (PPIase) domain with dynamitin, a component of the dynein-associated dynactin complex (Galigniana, M. D., Harrell, J. M., O'Hagen, H. M., Ljungman, M., and Pratt, W. B. (2004) J. Biol. Chem. 279, 22483-22489). Here, we show that CyP-A exists in native heterocomplexes containing cytoplasmic dynein that can be formed in cell-free systems. Prolyl isomerase activity is not required for forming the dynein complex, but the PPIase domain fragment of FKBP52 blocks complex formation and CyP-A binds to dynamitin in a PPIase domain-dependent manner. CyP-A heterocomplexes containing tubulin and dynein can be formed in cytosol prepared under microtubule-stabilizing conditions, and CyP-A colocalizes in mouse fibroblasts with microtubules. Colocalization with microtubules is disrupted by overexpression of the PPIase domain fragment. Thus, we conclude that CyP-A associates in vitro and in vivo with the dynein/dynactin motor protein complex and we suggest that CyP-A may perform a general function related to the binding of cargo for retrograde movement along microtubules.Fil: Galigniana, Mario Daniel. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Química Biológica; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. University of Michigan; Estados UnidosFil: Morishima, Yoshihiro. University of Michigan; Estados UnidosFil: Gallay, Philippe A.. The Scripps Research Institute; Estados UnidosFil: Pratt, William B.. University of Michigan; Estados Unido