The Distribution and Quality of Hine's Emerald Dragonfly Habitat in Relation to Surface and Groundwater Dynamics in the Lockport Prairie Preserve Preliminary Report (February 1, 2001-January 31, 2002)

INHS Technical Report prepared for Corporation for Openlands, US Fish and Wildlife Service

Shape and chemically anisotropic colloidal particles: A theoretical study of their structure, phase behavior, and slow dynamics

A detailed non-equilibrium state diagram of shape-anisotropic particle fluids is constructed. The effects of particle shape are explored using Naive Mode Coupling Theory (NMCT), and a single particle Non-linear Langevin Equation (NLE) theory. The dynamical behavior of non-ergodic fluids are discussed. We employ a rotationally frozen approach to NMCT in order to determine a transition to center of mass (translational) localization. Both ideal and kinetic glass transitions are found to be highly shape dependent, and uniformly increase with particle dimensionality. The glass transition volume fraction of quasi 1- and 2- dimensional particles fall monotonically with the number of sites (aspect ratio), while 3-dimensional particles display a non-monotonic dependence of glassy vitrification on the number of sites. Introducing interparticle attractions results in a far more complex state diagram. The ideal non-ergodic boundary shows a glass-fluid-gel re-entrance previously predicted for spherical particle fluids. The non-ergodic region of the state diagram presents qualitatively different dynamics in different regimes. They are qualified by the different behaviors of the NLE dynamic free energy. The caging dominated, repulsive glass regime is characterized by long localization lengths and barrier locations, dictated by repulsive hard core interactions, while the bonding dominated gel region has short localization lengths (commensurate with the attraction range), and barrier locations. There exists a small region of the state diagram which is qualified by both glassy and gel localization lengths in the dynamic free energy. A much larger (high volume fraction, and high attraction strength) region of phase space is characterized by short gel-like localization lengths, and long barrier locations. The region is called the attractive glass and represents a 2-step relaxation process whereby a particle first breaks attractive physical bonds, and then escapes its topological cage. The dynamic fragility of fluids are highly particle shape dependent. It increases with particle dimensionality and falls with aspect ratio for quasi 1- and 2- dimentional particles. An ultralocal limit analysis of the NLE theory predicts universalities in the behavior of relaxation times, and elastic moduli. The equlibrium phase diagram of chemically anisotropic Janus spheres and Janus rods are calculated employing a mean field Random Phase Approximation. The calculations for Janus rods are corroborated by the full liquid state Reference Interaction Site Model theory. The Janus particles consist of attractive and repulsive regions. Both rods and spheres display rich phase behavior. The phase diagrams of these systems display fluid, macrophase separated, attraction driven microphase separated, repulsion driven microphase separated and crystalline regimes. Macrophase separation is predicted in highly attractive low volume fraction systems. Attraction driven microphase separation is charaterized by long length scale divergences, where the ordering length scale determines the microphase ordered structures. The ordering length scale of repulsion driven microphase separation is determined by the repulsive range. At the high volume fractions, particles forgo the enthalpic considerations of attractions and repulsions to satisfy hard core constraints and maximize vibrational entropy. This results in site length scale ordering in rods, and the sphere length scale ordering in Janus spheres, i.e., crystallization. A change in the Janus balance of both rods and spheres results in quantitative changes in spinodal temperatures and the position of phase boundaries. However, a change in the block sequence of Janus rods causes qualitative changes in the type of microphase ordered state, and induces prominent features (such as the Lifshitz point) in the phase diagrams of these systems. A detailed study of the number of nearest neighbors in Janus rod systems reflect a deep connection between this local measure of structure, and the structure factor which represents the most global measure of order.

School leaders as both colonized and colonizers: understanding professional identity in an era of no child left behind

This study positioned the federal No Child Left Behind (NCLB) Act of 2002 as a reified colonizing entity, inscribing its hegemonic authority upon the professional identity and work of school principals within their school communities of practice. Pressure on educators and students intensifies each year as the benchmark for Adequate Yearly Progress under the NCLB policy is raised, resulting in standards-based reform, scripted curriculum and pedagogy, absence of elective subjects, and a general lack of autonomy critical to the work of teachers as they approach each unique class and student (Crocco & Costigan, 2007; Mabry & Margolis, 2006). Emphasis on high stakes standardized testing as the indicator for student achievement (Popham, 2005) affects educators’ professional identity through dramatic pedagological and structural changes in schools (Day, Flores, & Viana, 2007). These dramatic changes to the ways our nation conducts schooling must be understood and thought about critically from school leaders’ perspectives as their professional identity is influenced by large scale NCLB school reform. The author explored the impact No Child Left Behind reform had on the professional identity of fourteen, veteran Illinois principals leading in urban, small urban, suburban, and rural middle and elementary schools. Qualitative data were collected during semi-structured interviews and focus groups and analyzed using a dual theoretical framework of postcolonial and identity theories. Postcolonial theory provided a lens from which the author applied a metaphor of colonization to principals’ experiences as colonized-colonizers in a time of school reform. Principal interview data illustrated many examples of NCLB as a colonizing authority having a significant impact on the professional identity of school leaders. This framework was used to interpret data in a unique and alternative way and contributed to the need to better understand the ways school leaders respond to district-level, state-level, and national-level accountability policies (Sloan, 2000). Identity theory situated principals as professionals shaped by the communities of practice in which they lead. Principals’ professional identity has become more data-driven as a result of NCLB and their role as instructional leaders has intensified. The data showed that NCLB has changed the work and professional identity of principals in terms of use of data, classroom instruction, Response to Intervention, and staffing changes. Although NCLB defines success in terms of meeting or exceeding the benchmark for Adequate Yearly Progress, principals’ view AYP as only one measurement of their success. The need to meet the benchmark for AYP is a present reality that necessitates school-wide attention to reading and math achievement. At this time, principals leading in affluent, somewhat homogeneous schools typically experience less pressure and more power under NCLB and are more often labeled “successful” school communities. In contrast, principals leading in schools with more heterogeneity experience more pressure and lack of power under NCLB and are more often labeled “failing” school communities. Implications from this study for practitioners and policymakers include a need to reexamine the intents and outcomes of the policy for all school communities, especially in terms of power and voice. Recommendations for policy reform include moving to a growth model with multi-year assessments that make sense for individual students rather than one standardized test score as the measure for achievement. Overall, the study reveals enhancements and constraints NCLB policy has caused in a variety of school contexts, which have affected the professional identity of school leaders.