A case for collaboratives: Turning around the Bronx public schools

This article chronicles pace-setting collaborative educational programs which are succeeding in turning around Bronx public schools. It focuses on the results achieved when corporations, universities, cultural institutions, and health-care facilities become partners with the public schools to share their expertise, sophisticated technology, and superior financial resources with the city's children. The marshalling of new resources from outside the school establishment in support of a number of initiatives has set public education in the Bronx on a new course. The transformation of many troubled neighborhood high schools into theme schools which feature a particular career preparation has already brought dramatic changes in the borough's dropout rate and raised the aspirations of large numbers of students.     

Subtypes, severity, and structural stability of peer victimization: what does latent class analysis say?

This study uses latent class analysis (LCA) to empirically identify victimization groups during middle school. Approximately 2,000 urban, public middle school students (mean age in sixth grade = 11.57) reported on their peer victimization during the Fall and Spring semesters of their sixth, seventh, and eighth grades. Independent LCA analyses at each semester yielded 3 victim classes based on victimization degree rather than type (e.g., physical vs. relational). The most victimized class always represented the smallest proportion of the sample, decreasing from 20% in sixth grade to 6% by the end of eighth grade. This victimized class also always reported feeling less safe at school concurrently and more depressed than others 1 semester later, illustrating the validity of the LCA approach.     

Similarity of WISC-R and WAIS-R scores at age 16

Thirty learning disabled students of average intellectual ability between 16 and 17 years of age were given both the WISC-R and the WAIS-R to determine if the WAIS-R provided higher average IQ scores, as had been reported for educationally mentally retarded adolescents. The results indicated: (a) no significant differences between the two scales on either the Verbal, Performance, or Full Scale IQs, (b) significant correlations between the WISC-R and WAIS-R on the three IQ scores and 9 of the 11 subtests, and (c) the emergence of the ACID profile for learning disabled adolescents on both tests.     

Solution pH change in non-uniform alternating current electric fields at frequencies above the electrode charging frequency

AC Faradaic reactions have been reported as a mechanism inducing non-ideal phenomena such as flow reversal and cell deformation in electrokinetic microfluidic systems. Prior published work described experiments in parallel electrode arrays below the electrode charging frequency (f_c), the frequency for electrical double layer charging at the electrode. However, 2D spatially non-uniform AC electric fields are required for applications such as in plane AC electroosmosis, AC electrothermal pumps, and dielectrophoresis. Many microscale experimental applications utilize AC frequencies around or above f_c. In this work, a pH sensitive fluorescein sodium salt dye was used to detect [H⁺] as an indicator of Faradaic reactions in aqueous solutions within non-uniform AC electric fields. Comparison experiments with (a) parallel (2D uniform fields) electrodes and (b) organic media were employed to deduce the electrode charging mechanism at 5 kHz (1.5f_c). Time dependency analysis illustrated that Faradaic reactions exist above the theoretically predicted electrode charging frequency. Spatial analysis showed [H⁺] varied spatially due to electric field non-uniformities and local pH changed at length scales greater than 50 μm away from the electrode surface. Thus, non-uniform AC fields yielded spatially varied pH gradients as a direct consequence of ion path length differences while uniform fields did not yield pH gradients; the latter is consistent with prior published data. Frequency dependence was examined from 5 kHz to 12 kHz at 5.5 V_pp potential, and voltage dependency was explored from 3.5 to 7.5 V_pp at 5 kHz. Results suggest that Faradaic reactions can still proceed within electrochemical systems in the absence of well-established electrical double layers. This work also illustrates that in microfluidic systems, spatial medium variations must be considered as a function of experiment time, initial medium conditions, electric signal potential, frequency, and spatial position.