Leading the Initial Implementation Phase of TandemEd in Relationship with the Pittsburgh Public Schools

TandemEd facilitates Black communities to create campaigns that highlight their positive racial identity and self-defined educational purpose. This article examines leadership of the initial implementation phase of the TandemEd community initiative in relationship with the Pittsburgh Public Schools (PPS) focusing primarily on the interactions with the superintendent and executive director of the superintendent’s office. The results included ongoing support from PPS as TandemEd formed a citywide steering committee of highly community legitimated persons, executed a leadership and campaign academy for thirty-five Pittsburgh youth, and facilitated design and delivery of various cable television commercials on identity and purpose in the Greater Pittsburgh region. It utilized the organizational framework established in Reframing Organizations by Lee Bolman and Terrence Deal (1991). The implication being that while a relationship with a public school district at the onset of TandemEd city entry is of value, the greater value is found in first establishing a strong community-legitimated effort and intersecting with the district more deeply in later implementation phases. Additionally, there is transformative value for school and district leaders to be responsive to Black community leadership of education

Enlisting in the Military: The Influential Role of Genetic Factors

Given that enlistment in the U.S. military is completely voluntary, there has been a great deal of interest in identifying the various factors that might explain why some people join the military, whereas others do not. The current study expanded on this line of literature by estimating the extent to which genetic and environmental factors explained variance in the liability for lifetime participation in the military. Analysis of twin pairs drawn from the National Longitudinal Study of Adolescent to Adult Health (Add Health) revealed that 82% of the variance was the result of genetic factors, 18% of the variance was the result of nonshared environmental factors, and none of the variance was accounted for by shared environmental factors. In light of a number of limitations, replication studies are needed to determine the robustness of these findings and whether they are generalizable to other samples and populations

Photometric Decomposition of Barred Galaxies

We present a non-parametric method for decomposition of the light of disk galaxies into disk, bulge and bar components. We have developed and tested the method on a sample of 68 disk galaxies for which we have acquired I-band photometry. The separation of disk and bar light relies on the single assumption that the bar is a straight feature with a different ellipticity and position angle from that of the projected disk. We here present the basic method, but recognise that it can be significantly refined. We identify bars in only 47% of the more nearly face-on galaxies in our sample. The fraction of light in the bar has a broad range from 1.3% to 40% of the total galaxy light. If low-luminosity galaxies have more dominant halos, and if halos contribute to bar stability, the luminosity functions of barred and unbarred galaxies should differ markedly; while our sample is small, we find only a slight difference of low significance.Comment: Accepted to appear in AJ, 36 pages, 9 figures, full on-line figures available at http://www.physics.rutgers.edu/~sellwood/Reese.htm

A Quantitative Genetic Analysis of the Associations Among Language Skills, Peer Interactions, and Behavioral Problems in Childhood: Results From a Sample of Twins

A body of empirical research has revealed that there are associations among language skills, peer interactions, and behavioral problems in childhood. At the same time, however, there has been comparatively less research devoted to exploring the mutual unfolding of these factors over the first few years of life. The current study is designed to partially address this gap in the literature by examining how language skills, negative peer interactions, and behavioral problems are interrelated in a sample of twins drawn from the Early Childhood Longitudinal Study–Birth Cohort (ECLS-B). Employing a quantitative genetic framework, the results of the current study revealed that variance in language skills, negative peer interactions, and externalizing behavioral problems were all due to a combination of genetic and environmental factors. Bivariate Cholesky models indicated that most of the covariance among language skills, negative peer interactions, and externalizing behavioral problems was due to common genetic factors. Additional analyses using a modified DeFries–Fulker approach nested within a path model revealed a bidirectional association between negative peer interactions and externalizing behavioral problems, wherein there appeared to be feedback loops between the two. Implications of the results are discussed and avenues for future research are offered

MODIS-derived spatiotemporal water clarity patterns in optically shallow Florida Keys waters: A new approach to remove bottom contamination

Retrievals of water quality parameters from satellite measurements over optically shallow waters have been problematic due to bottom contamination of the signals. As a result, large errors are associated with derived water column properties. These deficiencies greatly reduce the ability to use satellites to assess the shallow water environments around coral reefs and seagrass beds. Here, a modified version of an existing algorithm is used to derive multispectral diffuse attenuation coefficient (Kd) from MODIS/Aqua measurements over optically shallow waters in the Florida Keys. Results were validated against concurrent in situ data (Kd(488) from 0.02 to 0.20 m−1, N = 22, R2 = 0.68, Mean Ratio = 0.93, unbiased RMS = 31%), and showed significant improvement over current products when compared to the same in situ data (N = 13, R2 = 0.37, Mean Ratio = 1.61, unbiased RMS = 50%). The modified algorithm was then applied to time series of MODIS/Aqua data over the Florida Keys (in particular, the Florida Keys Reef Tract), whereby spatial and temporal patterns of water clarity between 2002 and 2011 were elucidated. Climatologies, time series, anomaly images, and empirical orthogonal function analysis showed primarily nearshore–offshore gradients in water clarity and its variability, with peaks in both at the major channels draining Florida Bay. ANOVA revealed significant differences in Kd(488) according to distance from shore and geographic region. Excluding the Dry Tortugas, which had the lowest climatological Kd(488), water was clearest at the northern extent of the Reef Tract, and Kd(488) significantly decreased sequentially for every region along the tract. Tests over other shallow-water tropical waters such as the Belize Barrier Reef also suggested general applicability of the algorithm. As water clarity and light availability on the ocean bottom are key environmental parameters in determining the health of shallow-water plants and animals, the validated new products provide unprecedented information for assessing and monitoring of coral reef and seagrass health, and could further assist ongoing regional zoning efforts

A classification of spherically symmetric spacetimes

A complete classification of locally spherically symmetric four-dimensional Lorentzian spacetimes is given in terms of their local conformal symmetries. The general solution is given in terms of canonical metric types and the associated conformal Lie algebras. The analysis is based upon the local conformal decomposition into 2+2 reducible spacetimes and the Petrov type. A variety of physically meaningful example spacetimes are discussed

The DEEP2 Galaxy Redshift Survey: Clustering of Groups and Group Galaxies at z~1

We study the clustering properties of groups and of galaxies in groups in the DEEP2 Galaxy Redshift Survey dataset at z~1. Four clustering measures are presented: 1) the group correlation function for 460 groups with estimated velocity dispersions of sigma>200 km/s, 2) the galaxy correlation for the full galaxy sample, using a flux-limited sample of 9800 objects between 0.7<z<1.0, 3) the galaxy correlation for galaxies in groups, and 4) the group-galaxy cross-correlation function. Using the observed number density and clustering amplitude of the groups, the estimated minimum group dark matter halo mass is M_min~6 10^12 h^-1 M_Sun for a flat LCDM cosmology. Groups are more clustered than galaxies, with a relative bias of b=1.7 +/-0.04 on scales r_p=0.5-15 Mpc/h. Galaxies in groups are also more clustered than the full galaxy sample, with a scale-dependent relative bias which falls from b~2.5 +/-0.3 at r_p=0.1 Mpc/h to b~1 +/-0.5 at r_p=10 Mpc/h. The correlation functions for all galaxies and galaxies in groups can be fit by a power-law on scales r_p=0.05-20 Mpc/h. We empirically measure the contribution to the projected correlation function for galaxies in groups from a `one-halo' term and a `two-halo' term by counting pairs of galaxies in the same or in different groups. The projected cross-correlation between shows that red galaxies are more centrally concentrated in groups than blue galaxies at z~1. DEEP2 galaxies in groups appear to have a shallower radial distribution than that of mock galaxy catalogs made from N-body simulations, which assume a central galaxy surrounded by satellite galaxies with an NFW profile. We show that the clustering of galaxies in groups can be used to place tighter constraints on the halo model than can be gained from using the usual galaxy correlation function alone.Comment: 22 pages, 12 figures, in emulateapj format, accepted to ApJ, minor changes made to match published versio

Daily to decadal modulation of jet variability

The variance of a jet’s position in latitude is found to be related to its average speed: when a jet becomes stronger its variability in latitude decreases. This relationship is shown to hold for observed midlatitude jets around the world and also across a hierarchy of numerical models. North Atlantic jet variability is shown to be modulated on decadal timescales, with decades of a strong, steady jet being interspersed with decades of a weak, variable jet. These modulations are also related to variations in the basin-wide occurrence of high-impact blocking events. A picture emerges of complex multidecadal jet variability in which recent decades do not appear unusual. We propose an underlying barotropic mechanism to explain this behaviour, related to the change in refractive properties of a jet as it strengthens, and the subsequent effect on the distribution of Rossby wave breaking