1,918 research outputs found
White versus gray matter function as seen on neuropsychological testing following bone marrow transplant for acute leukemia in childhood
Current theory suggests that neurocognitive late effects of treatments for childhood cancer such as difficulties with attention, processing speed and visual-motor ability are the result of white matter damage. Neuroimaging studies have produced a variety of white matter findings. However, although white matter is thought to be differentially affected, previous studies have not demonstrated a discrepancy between white and gray matter function. The present study included 36 children treated for childhood leukemia with hematopoietic stem cell transplant (HCT). Their performance on neurocognitive measures traditionally thought to measure white matter was compared to performance on measures thought to measure gray matter function. Composite white and gray matter standard scores were created based on neuropsychological measures that individuals with known white or gray matter damage perform poorly. As predicted, composite white matter scores (mean = 98.1) were significantly lower (t = 2.26, p = 0.03) than composite gray matter scores (mean = 102.5). Additionally, as gray matter performance increased, the difference between gray and white matter scores increased (R = 0.353, p = 0.035). Overall, the results of this study support the current theory that white matter damage is responsible for the more subtle neurocognitive late effects resulting from treatment for childhood leukemia
Effect of pH on metabolism of the glutamine carbon skeleton by renal cortical mitochondria
1. 1. To determine the effect of altered acid-base homeostasis on the intramitochondrial metabolism of the glutamine carbon skeleton 14CO2 production from [U-14C]glutamine by isolated rat renal cortical mitochondria was measured.2. 2. Mitochondria from rats with chronic metabolic acidosis either showed no change or diminished 14CO2 production in comparison with pair fed controls.3. 3. By contrast, when the pH of the medium incubating mitochondria from normal rats was manipulated (pH 7.0, 7.4, 7.7), 14CO2 production was clearly altered, but the direction and magnitude of the change depended on the glutamine concentration used (0.5 or 10.0 mM).4. 4. Mitochondria produced significant quantities of 14CO2 when [1,4 14C]succinate was used as substrate, indicating that 14CO2 production from glutamine does not originate solely from the decarboxylation of [alpha] KG.5. 5. Thus chronic acidosis and pH, per se, affect intramitochondrial glutamine carbon skeleton metabolism in different fashions, but the specific mechanism cannot be elucidated using 14CO2 production from [U-14C]glutamine.6. 6. Additional studies directly quantitating the metabolic products of glutamine have confirmed these findings and more precisely defined the sites of metabolic alteration.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/23380/1/0000325.pd
More Efficient Public Schools In Maine: Learning Communities Building the Foundation of Intellectual Work
This report describes the methodology used to identify Maine schools that were outperforming expectations and reports the results from conducting case studies of a representative sample of these and other Maine schools. Through these case studies, we were able to uncover what the schools were doing that set them apart from other schools and what other schools may wish to emulate as they work to build the foundation for improvement within their own schools
More Efficient High Schools in Maine: Emerging StudentāCentered Learning Communities
The Center for Education Policy, Applied Research, and Evaluation at the University of Southern Maine conducted a study in 2010-2011 of a sample of Maine high schools. Funded in part by the Nellie Mae Education Foundation, the study examined the degree to which these More Efficient high schools were also student-centered.
This report describes the methodology used to identify Maine schools that were outperforming expectations and reports the results from conducting case studies of a representative sample of these and other Maine schools. Through these case studies, we were able to uncover what the schools were doing that set them apart from other schools and what other schools may wish to emulate as they work to build the foundation for improvement within their own schools
Close Packing of Atoms, Geometric Frustration and the Formation of Heterogeneous States in Crystals
To describe structural peculiarities in inhomogeneous media caused by the
tendency to the close packing of atoms a formalism based on the using of the
Riemann geometry methods (which were successfully applied lately to the
description of structures of quasicrystals and glasses) is developed. Basing on
this formalism we find in particular the criterion of stability of precipitates
of the Frank-Kasper phases in metallic systems. The nature of the ''rhenium
effect'' in W-Re alloys is discussed.Comment: 14 pages, RevTex, 2 PostScript figure
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