Living Our Lives on the Edge: Power, Space and Sexual Orientation in Cape Town Townships, South Africa

Much of social science literature about South African cities fails to represent its complex spectrum of sexual practices and associated identities. The unintended effects of such representations are that a compulsory heterosexuality is naturalised in, and reiterative with, dominant constructions of blackness in townships. In this paper, we argue that the assertion of discreet lesbian and gay identities in black townships of a South African city such as Cape Town is influenced by the historical racial and socio-economic divides that have marked urban landscape. In their efforts to recoup a positive sense of gendered personhood, residents have constructed a moral economy anchored in reproductive heterosexuality. We draw upon ethnographic data to show how sexual minorities live their lives vicariously in spaces they have prised open within the extant sex/gender binary. They are able to assert the identities of moffie and man-vrou (mannish woman) without threatening the dominant ideology of heterosexuality.

SUFFICIENT CONDITIONS ON DIFFUSIVITY FOR THE EXISTENCE AND NONEXISTENCE OF STABLE EQUILIBRIA WITH NONLINEAR FLUX ON THE BOUNDARY

A reaction-diffusion equation with variable diffusivity and non-linear flux boundary condition is considered. The goal is to give sufficient conditions on the diffusivity function for nonexistence and also for existence of nonconstant stable stationary solutions. Applications are given for the main result of nonexistence.

Report on the boundary between the Potsdam and Pre-Cambrian rocks north of the Adirondacks.

From 16th annual report of the state geologist, 1898.

On the nonlinear Neumann problem involving the critical Sobolev exponent on the boundary

in this paper we investigate the solvability of the Neumann problem (1.1) involving the critical Sobolev exponents on the right-hand side of the equation and in the boundary condition. It is assumed that the coefficients Q and P are smooth. We examine the common effect of the mean curvature of the boundary a deltaOhm and the shape of the graph of the coefficients Q and P on the existence of solutions of problem (1.1). (C) 2003 Published by Elsevier Inc.

A one-dimensional Keller-Segel equation with a drift issued from the boundary

We investigate in this note the dynamics of a one-dimensional Keller-Segel type model on the half-line. On the contrary to the classical configuration, the chemical production term is located on the boundary. We prove, under suitable assumptions, the following dichotomy which is reminiscent of the two-dimensional Keller-Segel system. Solutions are global if the mass is below the critical mass, they blow-up in finite time above the critical mass, and they converge to some equilibrium at the critical mass. Entropy techniques are presented which aim at providing quantitative convergence results for the subcritical case. This note is completed with a brief introduction to a more realistic model (still one-dimensional).

Monte Carlo thermodynamic and structural properties of the TIP4P water model: dependence on the computational conditions

Classical Monte Carlo simulations were carried out on the NPT ensemble at 25°C and 1 atm, aiming to investigate the ability of the TIP4P water model [Jorgensen, Chandrasekhar, Madura, Impey and Klein; J. Chem. Phys., 79 (1983) 926] to reproduce the newest structural picture of liquid water. The results were compared with recent neutron diffraction data [Soper; Bruni and Ricci; J. Chem. Phys., 106 (1997) 247]. The influence of the computational conditions on the thermodynamic and structural results obtained with this model was also analyzed. The findings were compared with the original ones from Jorgensen et al [above-cited reference plus Mol. Phys., 56 (1985) 1381]. It is notice that the thermodynamic results are dependent on the boundary conditions used, whereas the usual radial distribution functions g(O/O(r)) and g(O/H(r)) do not depend on them.

Effects of urban ventilation patterns on the carbon monoxide concentration in a high-rise mega city

Carbon monoxide (CO) concentration data from 1999–2006, monitored at 5 different pollution stations in a high-rise mega city (Hong Kong), were collected and investigated. The spatio-temporal characteristics of urban CO concentration profiles were obtained. A new approach was put forward to examine the relationship between urban CO concentration and different wind flow patterns. Rather than relying on the meteorological data from a single weather station, usually adopted in previous studies, four weather stations on the boundary of Hong Kong territory were used in the present study so as to identify 16 different wind flow patterns, among which a typical urban heat island circulation (UHIC) can be distinguished. Higher concentrations were observed to be associated with the flow pattern of an inflow from Lau Fau Shan (LFS) station which is located in the northwest of Hong Kong. This suggests that the ability of dilution for north-to-west wind is relatively weak due to the pollutants carried from outside Hong Kong. The effectiveness of wind speed on the alleviation of urban concentration is dependent on the initial concentration of the approaching wind. The increase of wind speed of north-to-west wind from 0 m/s to 6 m/s has little effect on the reduction of urban CO concentration, especially on the non-roadside stations. By contrast, for the southerly marine wind, pollution concentration decreases sharply with an increase in the wind speed. It was also found that urban heat island circulation (UHIC) is conducive of the accumulation of pollutants, especially at night. There exists a positive correlation between CO concentration and UHI intensity. This correlation is much stronger at night compared to during the day. Keywords: urban pollution monitoring, urban ventilation pattern, urban heat island circulation, mega city

Missing data mechanisms and their implications on the analysis of categorical data

We review some issues related to the implications of different missing data mechanisms on statistical inference for contingency tables and consider simulation studies to compare the results obtained under such models to those where the units with missing data are disregarded. We confirm that although, in general, analyses under the correct missing at random and missing completely at random models are more efficient even for small sample sizes, there are exceptions where they may not improve the results obtained by ignoring the partially classified data. We show that under the missing not at random (MNAR) model, estimates on the boundary of the parameter space as well as lack of identifiability of the parameters of saturated models may be associated with undesirable asymptotic properties of maximum likelihood estimators and likelihood ratio tests; even in standard cases the bias of the estimators may be low only for very large samples. We also show that the probability of a boundary solution obtained under the correct MNAR model may be large even for large samples and that, consequently, we may not always conclude that a MNAR model is misspecified because the estimate is on the boundary of the parameter space.

Reaction-diffusion systems coupled at the boundary and the Morse-Smale property

We study an one-dimensional nonlinear reaction-diffusion system coupled on the boundary. Such system comes from modeling problems of temperature distribution on two bars of same length, jointed together, with different diffusion coefficients. We prove the transversality property of unstable and stable manifolds assuming all equilibrium points are hyperbolic. To this end, we write the system as an equation with noncontinuous diffusion coefficient. We then study the nonincreasing property of the number of zeros of a linearized nonautonomous equation as well as the Sturm-Liouville properties of the solutions of a linear elliptic problem. (C) 2008 Elsevier Inc. All rights reserved.

Monte Carlo thermodynamic and structural properties of the TIP4P water model: dependence on the computational conditions

Classical Monte Carlo simulations were carried out on the NPT ensemble at 25°C and 1 atm, aiming to investigate the ability of the TIP4P water model [Jorgensen, Chandrasekhar, Madura, Impey and Klein; J. Chem. Phys., 79 (1983) 926] to reproduce the newest structural picture of liquid water. The results were compared with recent neutron diffraction data [Soper; Bruni and Ricci; J. Chem. Phys., 106 (1997) 247]. The influence of the computational conditions on the thermodynamic and structural results obtained with this model was also analyzed. The findings were compared with the original ones from Jorgensen et al [above-cited reference plus Mol. Phys., 56 (1985) 1381]. It is notice that the thermodynamic results are dependent on the boundary conditions used, whereas the usual radial distribution functions g(O/O(r)) and g(O/H(r)) do not depend on them.

Delay nonlinear boundary conditions as limit of reactions concentrating in the boundary

In this work, we are interested in the dynamic behavior of a parabolic problem with nonlinear boundary conditions and delay in the boundary. We construct a reaction-diffusion problem with delay in the interior, where the reaction term is concentrated in a neighborhood of the boundary and this neighborhood shrinks to boundary, as a parameter epsilon goes to zero. We analyze the limit of the solutions of this concentrated problem and prove that these solutions converge in certain continuous function spaces to the unique solution of the parabolic problem with delay in the boundary. This convergence result allows us to approximate the solution of equations with delay acting on the boundary by solutions of equations with delay acting in the interior and it may contribute to analyze the dynamic behavior of delay equations when the delay is at the boundary. (C) 2012 Elsevier Inc. All rights reserved.

On the possibility of elastic strain localisation in a fault

The phenomenon of strain localisation is often observed in shear deformation of particulate materials, e.g., fault gouge. This phenomenon is usually attributed to special types of plastic behaviour of the material (e.g., strain softening or mismatch between dilatancy and pressure sensitivity or both). Observations of strain localisation in situ or in experiments are usually based on displacement measurements and subsequent computation of the displacement gradient. While in conventional continua the symmetric part of the displacement gradient is equal to the strain, it is no longer the case in the more realistic descriptions within the framework of generalised continua. In such models the rotations of the gouge particles are considered as independent degrees of freedom the values of which usually differ from the rotation of an infinitesimal volume element of the continuum, the latter being described for infinitesimal deformations by the non-symmetric part of the displacement gradient. As a model for gouge material we propose a continuum description for an assembly of spherical particles of equal radius in which the particle rotation is treated as an independent degree of freedom. Based on this model we consider simple shear deformations of the fault gouge. We show that there exist values of the model parameters for which the displacement gradient exhibits a pronounced localisation at the mid-layers of the fault, even in the absence of inelasticity. Inelastic effects are neglected in order to highlight the role of the independent rotations and the associated additional parameters. The localisation-like behaviour occurs if (a) the particle rotations on the boundary of the shear layer are constrained (this type of boundary condition does not exist in a standard continuum) and (b) the contact moment-or bending stiffness is much smaller than the product of the effective shear modulus of the granulate and the square of the width of the gouge layer. It should be noted however that the virtual work functional is positive definite over the range of physically meaningful parameters (here: contact stiffnesses, solid volume fraction and coordination number) so that strictly speaking we are not dealing with a material instability.

On the numerical solution of a Cauchy problem in an elastostatic half-plane with a bounded inclusion

We propose an iterative procedure for the inverse problem of determining the displacement vector on the boundary of a bounded planar inclusion given the displacement and stress fields on an infinite (planar) line-segment. At each iteration step mixed boundary value problems in an elastostatic half-plane containing the bounded inclusion are solved. For efficient numerical implementation of the procedure these mixed problems are reduced to integral equations over the bounded inclusion. Well-posedness and numerical solution of these boundary integral equations are presented, and a proof of convergence of the procedure for the inverse problem to the original solution is given. Numerical investigations are presented both for the direct and inverse problems, and these results show in particular that the displacement vector on the boundary of the inclusion can be found in an accurate and stable way with small computational cost.

Beyond hope: Rhetorics of mobility, possibility, and literacy

When writing teachers enter the classroom, they often bring with them a deep faith in the power of literacy to rectify social inequalities and improve their students’ social and economic standing. It is this faith—this hope for change—that draws some writing teachers to locations of social and economic hardship. I am interested in how teachers and theorists construct their own narratives of social mobility, possibility, and literacy. My dissertation analyzes the production and expression of beliefs about literacy in the narratives of a diverse group of writing teachers and theorists, from those beginning their careers to those who are published and widely read. The central questions guiding this study are: How do teachers’ and theorists’ narratives of becoming literate intersect with literacy theories? and How do such literacy narratives intersect with beliefs in the power of literacy to improve individuals’ lives socially, economically, and personally? I contend that the professional literature needs to address more fully how teachers’ and theorists’ personal histories with literacy shape what they see as possible (and desirable) for students, especially those from marginalized communities. A central focus of the dissertation is on how teachers and theorists attempt to resolve a paradox they are likely to encounter in narratives about literacy. On one hand, they are immersed in a popular culture that cherishes narrative links between literacy and economic advancement (and, further, between such advancement and a “good life”). On the other hand, in professional discourse and in teacher preparation courses, they are likely to encounter narratives that complicate an assumed causal relationship between literacy and economic progress. Understanding, through literacy narratives, how teachers and theorists chart a practical path through or around this paradox can be beneficial to literacy education in three ways. First, it can offer direction in professional development and teacher education, addressing how teachers negotiate the boundaries between personal experience, theory, and pedagogy. Second, it can help teachers create spaces wherein students can explore the impact of paradoxical views about the role of literacy on their own lives. Finally, it can offer direction in public policy discourse, extending awareness of what we want—and need—from English language arts education in the twenty-first century. To explore these issues, I draw on case studies and ethnographic observation as well as narrative inquiry into teachers’ and theorists’ published literacy narratives. I situate my findings within three interrelated frames: 1) the narratives of new teachers, 2) the published works of literacy educators and theorists, and 3) my own literacy narrative. My first chapter, “Beyond Hope,” explores the tenuous connections between hope and critique in literacy studies and provides a methodological overview of the study. I argue that scholarship must move beyond a singular focus on either hope or critique in order to identify the transformative potential of literacy in particular circumstances. Analyzing literacy narratives provides a way of locating a critically informed sense of possibility. My second chapter, “Making Teachers, Making Literacy,” explores the intersection between teachers’ lives and the theories they study, based on qualitative analysis of a preservice course for secondary education English teachers. I examine how these preservice English teachers understood literacy, how their narratives of becoming literate and teaching English connected—and did not connect—with theoretical and pedagogical positions, and how these stories might inform their future work as practitioners. Centering primarily on preservice teachers who resisted Nancie Atwell’s pedagogy of possibility because they found it too good to be true, this research concentrates on moments of disjuncture, as expressed in class discussion and in one-on-one interviews, when literacy theories failed to align with aspiring teachers’ understandings of their own experiences and also with what they imagined as possible in disadvantaged educational settings. In my third and fourth chapters, I analyze the narratives of celebrated teachers and theorists who put forth an agenda that emphasizes possibilities through literacy, examining how they negotiate the relationship between their own literacy stories and literacy theories. Specifically, I investigate the narratives of three proponents of critical literacy: Mike Rose, Paulo Freire, and Myles Horton, all highly respected literacy teachers whose working-class backgrounds influenced their commitment to teaching in disenfranchised communities. In chapter 3, “Reading Lives on the Boundary,” I demonstrate how Mike Rose’s 1989 autobiographical text, Lives on the Boundary, juxtaposes rhetorics of mobility with critiques of such possibility. Through an analysis of work published in professional journals, I offer a reception history of Rose’s narrative, focusing specifically on how teachers have negotiated the tension between hope and critique. I follow this analysis with three case studies, drawn from a larger sampling, that inquire into the personal connections that writing teachers make with Lives on the Boundary. The teachers in this study, who provided written responses and participated in audio-recorded follow-up interviews, were asked to compare Rose’s story to their own stories, considering how their personal literacy histories influenced their teaching. My findings illustrate how a group of teachers and theorists have projected their own assessments of what literacy and higher education can and cannot accomplish onto this influential text. In my fourth chapter, “Horton and Freire’s Road as Literacy Narrative,” I concentrate on Myles Horton and Paulo Freire’s 1990 collaborative spoken book, We Make the Road by Walking. Central to my analysis are the educators’ stories about their formative years, including their own primary and secondary education experiences. I argue that We Make the Road by Walking demonstrates how theories of literacy cannot be divorced from personal histories. I begin by examining the spoken book as a literacy narrative that fuses personal and theoretical knowledge, focusing specifically on its authors’ ideas on theory. Drawing on Bakhtin’s notion of the chronotope—the intersection of time and space within narrative—I then explore the literacy narratives emerging from the production process of the book, in a video production about Horton and Freire’s meeting, and ultimately in the two men’s reflections on their childhood years (Dialogic). Interspersed with these accounts is archival material on the book’s editorial production that illustrates the value of increased dialogue between personal history and theories of literacy. My fifth chapter is both a reflective analysis and a qualitative study of my work at a men’s medium-high security prison in Illinois, where I conducted research and served as the instructor of an upper-level writing course, “Writing for a Change,” in the spring of 2009. Entitled “Doing Time with Literacy Narratives,” this chapter explores the complex ways in which literacy and incarceration are configured in students’ narratives as well as my own. With and against students’ stories, I juxtapose my own experiences with literacy, particularly in relation to being the son of an imprisoned father. In exploring the intersections between such stories, I demonstrate how literacy narratives can function as a heuristic for exploring beliefs about literacy between teachers and students both inside and outside of the prison-industrial complex. My conclusion pulls together the various themes that emerged in the three frames, from the making of new teachers to the published literacy narratives of teachers and theorists to my own literacy narrative. Writing teachers encounter considerable pressure to align their curricula with one or another theory of literacy, which has the effect of negating the authority of knowledge about literacy gleaned from experience as readers and writers. My dissertation contends that there is much to be gained by finding ways of articulating theories of literacy that encompass teachers’ knowledge of reading and writing as expressed in personal narratives of literacy. While powerful cultural rhetorics of upward social mobility often neutralize the critical potential of teachers’ own narratives of literacy—potential that has been documented by scholars in writing studies and allied disciplines—this is not always the case. The chapters in this dissertation offer evidence that hopeful and critical positions on the transformational possibilities of literacy are not mutually exclusive.