651 research outputs found
Teacher Migration From High-Performing Middle Schools: A Case Study
I recently conducted fieldwork to explore the dynamics of teacher migration and understand how it relates to teachers’ perceptions and attitudes. The research was conducted through the eyes of a sixth grade language arts/social studies’ teacher working in a middle school I will refer to as PLC (Professional Learning Community) Middle School. By spending extensive time and conducting multiple interviews with the teacher and other staff members, I was able to explore some of the reasons and conditions why teachers leave schools, particularly high-performing schools to teach in other high performing schools. Attending weekly meetings at all levels and content areas with migrating teachers, combined with interviews and document collection, allowed me to further understand the gap that exists between what a high-performing school professes to be and how it actually is perceived by its own teachers. This gap is what proves to be disconcerting and frustrating for teachers who are satisfied with teaching but consider relocation to meet further personal and professional challenges
Representing the Past and Future Post-9/11 Manhattan: Jonathan Lethem\u27s Chronic City and Colum McCann\u27s Let the Great World Spin as Disavowing Fiction
Jonathan Lethem’s 2009 novel Chronic City and Colum McCann’s 2009 novel Let the Great World Spin can each be read as unique forms of the post-9/11 novel. In this study, I take up the argument that much of the established scholarship analyzing post-9/11 fiction often examines the same set of texts and frequently employs similar theoretical lenses, more often than not a specific form of trauma analysis. I argue that McCann and Lethem’s novels can each be read as unique forms of the post-9/11 novel for the way each work incorporates the Freudian processes of fetishism and disavowal into their respective narratives. In two close readings, I analyze each text to demonstrate how these processes function and what they offer both the authors and readers of the novels
Attention Factors Compared to Other Predictors of Simulated Driving Performance Across Age Groups
Groups of young, middle-aged, and older adults performed a battery of computer-based attention tasks, the UFOV® and neuropsychological tests, and simulated low-speed driving in a suburban scenario. Results from the attention tasks were submitted to Maximum Likelihood factor analysis and 6 factors were extracted that explained more than 57% of the task variance. The factors were labeled speed, switching, visual search, executive, sustained, and divided attention in descending order of amount of task variance explained. The factor scores were used to predict simulated driving performance. Step-wise regressions were computed with driving performance as the criterion, and age, sex and the factor scores, the UFOV® scores, or the neuropsychological test scores as predictors. Results showed that the perceptual-motor speed and divided attention measures from the UFOV® and attention battery were more likely to explain driving performance variance than the neuropsychological tests
Seven exercises planned to stimulate the flow of ideas in creative composition
Thesis (Ed.M.)--Boston Universit
Vesivirus 2117 capsids more closely resemble sapovirus and lagovirus particles than other known vesivirus structures
Vesivirus 2117 is an adventitious agent that in 2009, was identified as a contaminant of CHO cells propagated in bioreactors at a pharmaceutical manufacturing plant belonging to Genzyme. The consequent interruption in supply of Fabrazyme and Cerezyme (drugs used to treat Fabry and Gaucher disease respectively), caused significant economic losses. Vesivirus 2117 is a member of the Caliciviridae; a family of small icosahedral viruses encoding a positive sense RNA genome. We have used cryo-electron microscopy and three dimensional image reconstruction to calculate a structure of vesivirus 2117 virus like particles as well as feline calicivirus and a chimeric sapovirus. We present a structural comparison of several members of the Caliciviridae, showing that the distal P domain of vesivirus 2117 is morphologically distinct from that seen in other known vesivirus structures. Furthermore, at intermediate resolutions we found a high level of structural similarity between vesivirus 2117 and Caliciviridae from other genera, such as sapovirus and rabbit haemorrhagic disease virus. Phylogenetic analysis confirms vesivirus 2117 as a vesivirus closely related to canine vesiviruses. We postulate that morphological differences in virion structure seen between vesivirus clades may reflect differences in receptor usage
The Proteus Navier-Stokes code
An effort is currently underway at NASA Lewis to develop two- and three-dimensional Navier-Stokes codes, called Proteus, for aerospace propulsion applications. The emphasis in the development of Proteus is not algorithm development or research on numerical methods, but rather the development of the code itself. The objective is to develop codes that are user-oriented, easily-modified, and well-documented. Well-proven, state-of-the-art solution algorithms are being used. Code readability, documentation (both internal and external), and validation are being emphasized. This paper is a status report on the Proteus development effort. The analysis and solution procedure are described briefly, and the various features in the code are summarized. The results from some of the validation cases that have been run are presented for both the two- and three-dimensional codes
Methodology comparison for canopy structure parameters extraction from digital hemispherical photography in boreal forests
The retrieval of canopy architectural parameters using off-the-shelf digital cameras with fish-eye lens is investigated. The technique used takes advantage of the sensor’s linear response to light of these cameras to improve the estimation of gap fraction using: (1) the digital numbers of mixed sky-canopy pixels to estimate the within-pixel gap fraction; and (2) this process is done considering the variation in view zenith angle to take into account the sky radiance distribution and the canopy multiple scattering effects. The foliage element clumping index is retrieved over a wide range of view zenith angles using: (1) the accumulated gap size distribution theory developed for the TRAC by Chen and Cihlar (1995a); (2) the Lang and Xiang (1986) finite-length averaging method; and (3) a method combining the gap size distribution and the Lang and Xiang finite-length methods. Using data from Canadian and Russian boreal forests, comparisons of gap fraction, clumping index and plant area index measured with the tracing radiation and architecture of canopies (TRAC) and digital hemispherical photography are presented. Evaluation of the LAI estimated from digital hemispherical photography with allometric LAI of two boreal forest stands suggest that that the clumping index combined method may be more accurate
Near-IR search for lensed supernovae behind galaxy clusters: III. Implications for cluster modeling and cosmology
Massive galaxy clusters at intermediate redshifts act as gravitational lenses
that can magnify supernovae (SNe) occurring in background galaxies. We assess
the possibility to use lensed SNe to put constraints on the mass models of
galaxy clusters and the Hubble parameter at high redshift. Due to the standard
candle nature of Type Ia supernovae (SNe Ia), observational information on the
lensing magnification from an intervening galaxy cluster can be used to
constrain the model for the cluster mass distribution. A statistical analysis
using parametric cluster models was performed to investigate the possible
improvements from lensed SNe Ia for the accurately modeled galaxy cluster A1689
and the less well constrained cluster A2204. Time delay measurements obtained
from SNe lensed by accurately modeled galaxy clusters can be used to measure
the Hubble parameter. For a survey of A1689 we estimate the expected rate of
detectable SNe Ia and of multiply imaged SNe. The velocity dispersion and core
radius of the main cluster potential show strong correlations with the
predicted magnifications and can therefore be constrained by observations of
SNe Ia in background galaxies. This technique proves especially powerful for
galaxy clusters with only few known multiple image systems. The main
uncertainty for measurements of the Hubble parameter from the time delay of
strongly lensed SNe is due to cluster model uncertainties. For the extremely
well modeled cluster A1689, a single time delay measurement could be used to
determine the Hubble parameter with a precision of ~ 10%. We conclude that
observations of SNe Ia behind galaxy clusters can be used to improve the mass
modeling of the large scale component of galaxy clusters and thus the
distribution of dark matter. Time delays from SNe strongly lensed by accurately
modeled galaxy clusters can be used to measure the Hubble constant at high
redshifts.Comment: 10 pages, 8 figures, 3 tables. Accepted for publication in A&
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