The Influence of the Length of the Instructional Day on the Percentage of Proficient and Advanced Proficient Scores of the New Jersey Assessment of Skills and Knowledge for Grades 6, 7, and 8.

This study was relational, non-experimental, explanatory, and cross-sectional in nature, using quantitative methods to explain the influence of student, staff, and school independent variables on 6th, 7th, and 8th grade student achievement in both Language Arts and Mathematics on the 2011 NJ ASK. The variable of interest was the length of the instructional day and controlled student, staff, and school variables. This study provides descriptive research on the relationship between the length of the instructional day and other predictor variables and student achievement. The study used approximately 200 schools for each grade level and subject area combination. The percentage of students eligible for free and reduced lunch (%FRL) was found to be the strongest predictor on the 2011 NJ ASK Language Arts and Mathematics for Grades 6, 7, and 8 in this study. Student attendance was also found to be a statistically significant predictor of the percentage of students scoring Proficient and Advanced Proficient on the NJ ASK Language Arts and Mathematics for Grades 6, 7, and 8. There is no statistically significant relationship between the length of the instructional day and the percentage of students Proficient and Advanced Proficient on the NJ ASK Language Arts and Mathematics scores for Grades 6, 7, and 8

The Influence of the Length of the Instructional Day on the Percentage of Proficient and Advanced Proficient Scores of the New Jersey Assessment of Skills and Knowledge for Grades 6, 7, and 8.

This study was relational, non-experimental, explanatory, and cross-sectional in nature, using quantitative methods to explain the influence of student, staff, and school independent variables on 6th, 7th, and 8th grade student achievement in both Language Arts and Mathematics on the 2011 NJ ASK. The variable of interest was the length of the instructional day and controlled student, staff, and school variables. This study provides descriptive research on the relationship between the length of the instructional day and other predictor variables and student achievement. The study used approximately 200 schools for each grade level and subject area combination. The percentage of students eligible for free and reduced lunch (%FRL) was found to be the strongest predictor on the 2011 NJ ASK Language Arts and Mathematics for Grades 6, 7, and 8 in this study. Student attendance was also found to be a statistically significant predictor of the percentage of students scoring Proficient and Advanced Proficient on the NJ ASK Language Arts and Mathematics for Grades 6, 7, and 8. There is no statistically significant relationship between the length of the instructional day and the percentage of students Proficient and Advanced Proficient on the NJ ASK Language Arts and Mathematics scores for Grades 6, 7, and 8

The Bulge-Halo Connection in Galaxies: A Physical Interpretation of the Vcirc-sigma_0 Relation

We explore the dependence of the ratio of a galaxy's circular velocity, Vcirc, to its central velocity dispersion, sigma_0, on morphology, or equivalently total light concentration. Such a dependence is expected if light traces the mass. Over the full range of galaxy types, masses and brightnesses, and assuming that the gas velocity traces the circular velocity, we find that galaxies obey the relation log(Vcirc/sigma_0)= 0.63-0.11*C28 where C28=5log(r80/r20) and the radii are measured at 80 percent and 20 percent of the total light. Massive galaxies scatter about the Vcirc = sqrt(2)*sigma_0 line for isothermal stellar systems. Disk galaxies follow the simple relation Vcirc/sigma_0=2(1-B/T), where B/T is the bulge-to-total light ratio. For pure disks, C28~2.8, B/T -> 0, and Vcirc~=2*sigma_0. Self-consistent equilibrium galaxy models from Widrow & Dubinski (2005) constrained to match the size-luminosity and velocity-luminosity relations of disk galaxies fail to match the observed Vcirc/sigma_0 distribution. Furthermore, the matching of dynamical models for Vcirc(r)/sigma(r) with observations of dwarf and elliptical galaxies suffers from limited radial coverage and relatively large error bars; for dwarf systems, however, kinematical measurements at the galaxy center and optical edge suggest Vcirc(Rmax) > 2*sigma_0 (in contrast with past assumptions that Vcirc = sqrt(2)*sigma_0 for dwarfs.) The Vcirc-sigma_0-C28 relation has direct implications for galaxy formation and dynamical models, galaxy scaling relations, the mass function of galaxies, and the links between respective formation and evolution processes for a galaxy's central massive object, bulge, and dark matter halo.Comment: Accepted for publication in ApJL. Current version matches ApJL page requiremen

Bulge-Disk Decompositions and Structural Bimodality of Ursa Major Cluster Spiral Galaxies

We present bulge and disk (B/D) decompositions of existing K'-band surface brightness profiles for 65 Ursa Major cluster spiral galaxies. This improves upon the disk-only fits of Tully et al. (1996). The 1996 disk fits were used by Tully & Verheijen (1997) for their discovery of the bimodality of structural parameters in the UMa cluster galaxies. It is shown that our new 1D B/D decompositions yield disk structural parameters that differ only slightly from the basic fits of Tully et al. and evidence for structural bimodality of UMa galaxies is maintained. Our B/D software for the decomposition of 1D surface brightness profiles of galaxies uses a non-linear minimization scheme to recover the best fitting Sersic bulge and exponential disk while accounting for the possible presence of a compact nucleus and spiral arms and for the effects of seeing and disk truncations. In agreement with Tully & Verheijen, we find that the distribution of near-infrared disk central surface brightnesses is bimodal with an F-test confidence of 80%. There is also strong evidence for a local minimum in the luminosity function at M_K' ~ -22. A connection between the brightness bimodality and a dynamical bimodality, based on new HI line widths, is identified. The B/D parameters are presented in an Appendix.Comment: Accepted for publication in MNRA

Perceived discrimination, coping options and their relationship to mental health and psychological distress in homeless adults

While homelessness is associated with mental illness, what is not fully understood is how these are connected. In seeking to address this issue the present research uses a social identity approach to consider the relationship between homelessness and mental health, focusing on the roles of perceived discrimination, social identity, social support and coping options. It is guided by previous research which examines the relationship between these factors and mental health for other stigmatised groups. This previous research finds that perceived discrimination is negatively associated with mental health, but stigmatised groups can buffer these negative effects through increased social identity. Two mechanisms have been put forward to explain this buffering effect: social identity provides access to increased ingroup support and also makes group level coping strategies possible. The current research examines whether these findings hold for homeless people. In addition, identity with, and perceived support from family is also considered. A quantitative cross-sectional design was employed to examine these relationships. Data was collected from an opportunistic sample of 188 homeless adults accessing services for homeless people in Yorkshire. The current research finds that homeless people do perceive discrimination and this is associated with negative psychological outcomes. While socially identifying with homeless people is associated with increased perceived ingroup support and group coping options, these do not ameliorate the negative relationship between perceived discrimination and mental health. Moreover, perceived support and group coping options were associated with negative psychological outcomes in certain conditions. The relationships between psychological outcomes and family identity and support were also mixed Overall, these findings highlights the negative association between homelessness and mental health via social identity related processes but unlike other stigmatised minorities, the homeless identity does not provide access to stress buffering resources. The practical implications for services working with homeless people are discussed

The Principal Axis of the Virgo Cluster

Using accurate distances to individual Virgo cluster galaxies obtained by the method of Surface Brightness Fluctuations, we show that Virgo's brightest ellipticals have a remarkably collinear arrangement in three dimensions. This axis, which is inclined by 10 to 15 degrees from the line of sight, can be traced to even larger scales where it appears to join a filamentary bridge of galaxies connecting Virgo to the rich cluster Abell 1367. The orientations of individual Virgo ellipticals also show some tendency to be aligned with the cluster axis, as does the jet of the supergiant elliptical M87. These results suggest that the formation of the Virgo cluster, and its brightest member galaxies, have been driven by infall of material along the Virgo-A1367 filament.Comment: 8 pages, 4 figures, accepted for publication in ApJ Letter

Understanding English with lattice-learning

Thesis (M. Eng.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 2008.Includes bibliographical references (p. 49).A computer program that can understand the meaning of written English must be tremendously complex. It would break the spirit of any programmer to try to code such a program by hand; the range of meaning we can express in natural language is far too broad, too nuanced, too filled with exception. So I present UNDERSTAND, a program you can teach by example. Learning by example is an engineering expedient: it is much easier for us to come up with specific examples of a concept than some sort of perfect Platonic model. UNDERSTAND uses a technique I call Lattice-Learning to generalize accurately from just a few examples: "Robins, bees and helicopters can fly, but cats, worms and boats cannot," is enough for UNDERSTAND to narrow in on our concept of flying things: birds, insects and aircraft. It takes only 8 positive and 4 negative examples to teach UNDERSTAND how to interpret sentences as complicated as "The cat ran from the yard because a dog appeared." UNDERSTAND is implemented in 2300 lines of Java.by Michael Tully Klein, Jr.M.Eng

Abundance Profiles and Kinematics of Damped Lyman-alpha Absorbing Galaxies at z < 0.65

We present a spectroscopic study of six damped Lya absorption (DLA) systems at z<0.65, based on moderate-to-high resolution spectra of the galaxies responsible for the absorbers. Combining known metallicity measurements of the absorbers with known optical properties of the absorbing galaxies, we confirm that the low metal content of the DLA population can arise naturally as a combination of gas cross-section selection and metallicity gradients commonly observed in local disk galaxies. We also study the Tully-Fisher relation of the DLA-selected galaxies and find little detectable evidence for evolution in the disk population between z=0 and z~0.5. Additional results of our analysis are as follows. (1) The DLA galaxies exhibit a range of spectral properties, from post-starburst, to normal disks, and to starburst systems, supporting the idea that DLA galaxies are drawn from the typical field population. (2) Large rotating HI disks of radius 30 h^{-1} kpc and of dynamic mass M_dyn > 10^{11} h^{-1} M_sun appear to be common at intermediate redshifts. (3) Using an ensemble of six galaxy-DLA pairs, we derive an abundance profile that is characterized by a radial gradient of -0.041 +/- 0.012 dex per kiloparsec (or equivalently a scale length of 10.6 h^{-1} kpc) from galactic center to 30 h^{-1} kpc radius. (4) Adopting known N(HI) profiles of nearby galaxies and the best-fit radial gradient, we further derive an N(HI)-weighted mean metallicity _weighted = -0.50 +/- 0.07 for the DLA population over 100 random lines of sight, consistent with _weighted = -0.64 (-0.86, +0.40) observed for z~1 DLA systems from Prochaska et al. Our analysis demonstrates that the low metal content of DLA systems does not rule out the possibility that the DLA population trace the field galaxy population.Comment: 57 pages, 17 figures, to appear in the ApJ 20 February 2005 issue; a pdf version of the paper with full-resolution figures is available at http://falcon.mit.edu/~hchen/public/tmp/dlachem.pd

The Extragalactic Distance Scale without Cepheids IV

The Cepheid period-luminosity relation is the primary distance indicator used in most determinations of the Hubble constant. The tip of the red giant branch (TRGB) is an alternative basis. Using the new ANU SkyMapper Telescope, we calibrate the Tully Fisher relation in the I band. We find that the TRGB and Cepheid distance scales are consistent.Comment: ApJ in press 201