Exploring the Nature of the Co-emergence of Students\u27 Representational Fluency and Functional Thinking

Abstract In this dissertation, I explore ways to support secondary school students\u27 meaningful understanding of quadratic functions. Specifically, I investigate how students co-developed representational fluency (RF) and functional thinking (FT), when they gained meaningful understanding of quadratic functions. I also characterize students\u27 co-emergence of RF and FT on each representation (e.g., a graph, a symbolic equation, and a table) and across multiple representations. To accomplish these goals, I employed a design research methodology: a teaching experiment with eight Turkish-American secondary school students in an after-school context at a Turkish Community Center. I constructed the design principles and design elements for the study by networking two distinct domains of literature—representations and quantitative reasoning—to support students\u27 meaningful learning. I conducted ongoing and retrospective analyses on the enhanced transcriptions of small- and whole-group interactions. The analyses revealed a learning-ecology framework that supported secondary school students\u27 meaningful understanding of quadratic functions. The learning-ecology framework consisted of three components: enacted task characteristics, teacher pedagogical moves, and socio-mathematical norms. Furthermore, the findings showed that students employed two types of reasoning when they created and connected representations of quantities and the relationships between them: static thinking and lateral thinking. Static thinking is recalling a learned fact to represent a quantitative relationship with no attention to how quantities covary on a representation, while lateral thinking is a creative way of thinking wherein students conceive of concrete representations of functions as an emergent quantitative relationship. The findings also showed that students\u27 co-emergence of RF and FT can be operationalized into four levels starting from lesser sophisticated reasoning to greater sophisticated reasoning. Level 0 is a disconnection, level 1 is a partial connection, level 2 is a connection and level 3 is flexible a connection between students\u27 RF and FT. The dissertation informs teachers and the mathematics education community by (a) reporting and verifying the learning-ecology framework that supported students\u27 meaningful understanding of quadratic functions; and (b) characterizing students\u27 co-emergence of RF and FT within and across multiple representations

Job Search Assistance in Sweden: The Role of Mentorship and Support & Matching Programs in Migrant Women’s Job Searches

Currently, there are different programs based on job search assistance to provide career guidance and job match for foreign-born unemployed individuals in Sweden. Regarding job search assistance programs, this study examines the roles of mentorship programs and support & matching programs in Malmö and Lund, Sweden, where one of the program goals is to increase participation of foreign-born women in the Swedish labour market. By using Pierre Bourdieu and Nan Lin’s theoretical approaches, this study essentially examines the migrant women’s experiences during their program participation in terms of their social and cultural capital. In this context, it also explores the experiences of the programs’ staff in relation to social networking in the programs. The main findings of this study are that the programs’ supportive role could enable migrant women to enhance their social capital by increasing their social networks and mobilizing the resources of those networks in their job search. Although their matching role could pave the way for capitalizing on the institutionalized cultural capital of migrant women, the programs’ professional networks might be insufficient to enable migrant women to utilize their foreign education in their professions in Sweden. The reason for this could be because of the structural challenges and limited resources of some of these networks. Lastly, the programs’ educational role could familiarize migrant women with the rules in the Swedish employment field. This could lead migrant women to increase their embodied cultural capital in relation to locally-shared professional work culture in the Swedish employment field

Exploring The Nature Of The Co-emergence Of Students’ Representational Fluency And Functional Thinking

Abstract In this dissertation, I explore ways to support secondary school students’ meaningful understanding of quadratic functions. Specifically, I investigate how students co-developed representational fluency (RF) and functional thinking (FT), when they gained meaningful understanding of quadratic functions. I also characterize students’ co-emergence of RF and FT on each representation (e.g., a graph, a symbolic equation, and a table) and across multiple representations. To accomplish these goals, I employed a design research methodology: a teaching experiment with eight Turkish-American secondary school students in an after-school context at a Turkish Community Center. I constructed the design principles and design elements for the study by networking two distinct domains of literature—representations and quantitative reasoning—to support students’ meaningful learning. I conducted ongoing and retrospective analyses on the enhanced transcriptions of small- and whole-group interactions. The analyses revealed a learning-ecology framework that supported secondary school students’ meaningful understanding of quadratic functions. The learning-ecology framework consisted of three components: enacted task characteristics, teacher pedagogical moves, and socio-mathematical norms. Furthermore, the findings showed that students employed two types of reasoning when they created and connected representations of quantities and the relationships between them: static thinking and lateral thinking. Static thinking is recalling a learned fact to represent a quantitative relationship with no attention to how quantities covary on a representation, while lateral thinking is a creative way of thinking wherein students conceive of concrete representations of functions as an emergent quantitative relationship. The findings also showed that students’ co-emergence of RF and FT can be operationalized into four levels starting from lesser sophisticated reasoning to greater sophisticated reasoning. Level 0 is a disconnection, level 1 is a partial connection, level 2 is a connection and level 3 is flexible a connection between students’ RF and FT. The dissertation informs teachers and the mathematics education community by (a) reporting and verifying the learning-ecology framework that supported students’ meaningful understanding of quadratic functions; and (b) characterizing students’ co-emergence of RF and FT within and across multiple representations

Immigrant Labor in Contemporary Southern Literature, 1980-2010

This dissertation project emerges from an interest in immigrant labor, the globalization of southern literature, and the ways in which laboring bodies, specifically those of food processing workers, casino workers and motel workers, are represented in contemporary literary and cultural productions. Literary and cultural productions about immigrants and immigrant labor aim to problematize and challenge the dominant perception of immigration and narratives of immigration that continue to perpetuate ideas of exploitation and alterity. In doing so, these texts contribute to the reconstruction of the U.S. South as a global region and to the liberation of southern literature from traditional conceptual models that reinforce its insularity and exceptionality. The introduction of this project argues for a different way of reading immigrant narratives that deconstruct binaries in the region in order to situate new immigrant narratives as contributing to the extension of the boundaries and borders of the southern literature. Here the movement of people across constructed national boundaries is no longer situated between spatially and temporally differentiated areas, but instead is seen as taking place within a global system. The contemporary cultural productions analyzed in the dissertation provide varying representations of immigrant labor and labor exploitation and include works of literature and a film. The first chapter examines the ways in which the contemporary immigrant narrative is employed in the novel Holy Radishes! by Roberto G. Fernández in order to trace the perpetuation of labor exploitation through exiled female employees of a food processing plant in Florida. Chapter two provides an analysis of Tom Wolfe\u27s A Man in Full and focuses on the novel\u27s rendering of undocumented immigrant workers in food processing plants and its challenges to the ideological and Social perceptions of immigrant labor. The third chapter focuses on representations of immigrant labor, which is performed in the public sphere of the casino industry in Cynthia Shearer\u27s The Celestial Jukebox. The final chapter analyzes Mira Nair\u27s film Mississippi Masala and concentrates on the labor of Indian motel workers addressing, as in the previous chapters, deep-rooted labor history and historical labor traumas in the region

Sol-derived Hydroxyapatite Ddip-coating of a Porous Ti6Al4V Powder Compact

A sintered porous Ti6Al4V powder compact with a mean pore size of 63 µm and an average porosity of 37±1% was dip-coated at soaking times varying between 1- and 5-minute using a sol-derived calcium Hydrooxyapatite (HA) powder. The coated compacts were heat-treated at 840 oC. The coating thickness was found to increase with increasing soaking time, from 1.87 µm at 1-minute soaking to 9 µm at 5-minute soaking on the average. It was shown that at increasing soaking times, the originally open pores started to close, while at low soaking times the Ti6Al4V particles were partially coated. The coating layer was shown to be nano porous and the depth of coating was observed to be relatively shallow: only few particles near the compact surface were HA-coated

Secretome Analysis of Vibrio cholerae Type VI Secretion System Reveals a New Effector-Immunity Pair

ABSTRACT The type VI secretion system (T6SS) is a dynamic macromolecular organelle that many Gram-negative bacteria use to inhibit or kill other prokaryotic or eukaryotic cells. The toxic effectors of T6SS are delivered to the prey cells in a contact-dependent manner. In Vibrio cholerae, the etiologic agent of cholera, T6SS is active during intestinal infection. Here, we describe the use of comparative proteomics coupled with bioinformatics to identify a new T6SS effector-immunity pair. This analysis was able to identify all previously identified secreted substrates of T6SS except PAAR (proline, alanine, alanine, arginine) motif-containing proteins. Additionally, this approach led to the identification of a new secreted protein encoded by VCA0285 (TseH) that carries a predicted hydrolase domain. We confirmed that TseH is toxic when expressed in the periplasm of Escherichia coli and V. cholerae cells. The toxicity observed in V. cholerae was suppressed by coexpression of the protein encoded by VCA0286 (TsiH), indicating that this protein is the cognate immunity protein of TseH. Furthermore, exogenous addition of purified recombinant TseH to permeabilized E. coli cells caused cell lysis. Bioinformatics analysis of the TseH protein sequence suggest that it is a member of a new family of cell wall-degrading enzymes that include proteins belonging to the YD repeat and Rhs superfamilies and that orthologs of TseH are likely expressed by species belonging to phyla as diverse as Bacteroidetes and Proteobacteria

Characterization of Viral Insulins Reveals White Adipose Tissue Specific Effects in Mice [preprint]

Members of the insulin/IGF superfamily are well conserved across the evolutionary tree. We recently showed that four viruses in the Iridoviridae family possess genes that encode proteins highly homologous to human insulin/IGF-1. Using chemically synthesized single chain (sc), i.e. IGF-1-like, forms of the viral insulin/IGF-1 like peptides (VILPs), we previously showed that they can stimulate human receptors. Because these peptides possess potential cleavage sites to form double chain (dc), i.e. more insulin-like, VILPs, in this study, we have characterized dc forms of VILPs for Grouper iridovirus (GIV), Singapore grouper iridovirus (SGIV) and Lymphocystis disease virus-1 (LCDV-1). GIV and SGIV dcVILPs bind to both isoforms of human insulin receptor (IR-A, IR-B) and to the IGF1R, and for the latter show higher affinity than human insulin. These dcVILPs stimulate IR and IGF1R phosphorylation and post-receptor signaling in vitro and in vivo. Both GIV and SGIV dcVILPs stimulate glucose uptake in mice. In vivo infusion experiments in awake mice revealed that while insulin (0.015 nmol/kg/min) and GIV dcVILP (0.75nmol/kg/min) stimulated a comparable glucose uptake in heart, skeletal muscle and brown adipose tissue, GIV dcVILP stimulated ~2 fold higher glucose uptake in white adipose tissue (WAT) compared to insulin. This was associated with increased Akt phosphorylation and glucose transporter type 4 (GLUT4) gene expression compared to insulin. Taken together, these results show that GIV and SGIV dcVILPs are active members of the insulin superfamily with unique characteristics. Elucidating the mechanism of tissue specificity for GIV dcVILP will help us to better understand insulin action, design new analogues that specifically target the tissues, and provide new insights into their potential role in disease

Interaction of a viral insulin-like peptide with the IGF-1 receptor produces a natural antagonist

Lymphocystis disease virus-1 (LCDV-1) and several other Iridoviridae encode viral insulin/IGF-1 like peptides (VILPs) with high homology to human insulin and IGFs. Here we show that while single-chain (sc) and double-chain (dc) LCDV1-VILPs have very low affinity for the insulin receptor, scLCDV1-VILP has high affinity for IGF1R where it can antagonize human IGF-1 signaling, without altering insulin signaling. Consequently, scLCDV1-VILP inhibits IGF-1 induced cell proliferation and growth hormone/IGF-1 induced growth of mice in vivo. Cryo-electron microscopy reveals that scLCDV1-VILP engages IGF1R in a unique manner, inducing changes in IGF1R conformation that led to separation, rather than juxtaposition, of the transmembrane segments and hence inactivation of the receptor. Thus, scLCDV1-VILP is a natural peptide with specific antagonist properties on IGF1R signaling and may provide a new tool to guide development of hormonal analogues to treat cancers or metabolic disorders sensitive to IGF-1 without affecting glucose metabolism. The authors previously identified a family of viral insulin-like peptides (VILPs) with high homology to human insulin/IGF−1. Here, they report that one of these VILPs exhibits antagonist properties associated with a unique conformation of the IGF1R

Viral Gastroenteritis Associated with Genogroup II Norovirus among U.S. Military Personnel in Turkey, 2009

The present study demonstrates that multiple NoV genotypes belonging to genogroup II contributed to an acute gastroenteritis outbreak at a US military facility in Turkey that was associated with significant negative operational impact. Norovirus (NoV) is an important pathogen associated with acute gastroenteritis among military populations. We describe the genotypes of NoV outbreak occurred at a United States military facility in Turkey. Stool samples were collected from 37 out of 97 patients presenting to the clinic on base with acute gastroenteritis and evaluated for bacterial and viral pathogens. NoV genogroup II (GII) was identified by RT-PCR in 43% (16/37) stool samples. Phylogenetic analysis of a 260 base pair fragment of the NoV capsid gene from ten stool samples indicated the circulation of multiple and rare genotypes of GII NoV during the outbreak. We detected four GII.8 isolates, three GII.15, two GII.9 and a sole GII.10 NoV. Viral sequences could be grouped into four clusters, three of which have not been previously reported in Turkey. The fact that current NoV outbreak was caused by rare genotypes highlights the importance of norovirus strain typing. While NoV genogroup II is recognized as causative agent of outbreak, circulation of current genotypes has been rarely observed in large number of outbreaks