103 research outputs found

    Increased L‐[1– 11 C] Leucine Uptake in the Leptomeningeal Angioma of Sturge‐Weber Syndrome: A PET Study

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    BACKGROUND AND PURPOSE We used L‐[1– 11 C]leucine (LEU) positron emission tomography (PET) to measure amino acid uptake in children with Sturge‐Weber syndrome (SWS), and to relate amino acid uptake measures with glucose metabolism. METHODS LEU and 2‐deoxy‐2[ 18 F]fluoro‐D‐glucose (FDG) PET were performed in 7 children (age: 5 months‐13 years) with unilateral SWS. Asymmetries of LEU uptake in the posterior brain region, underlying the angioma and in frontal cortex, were measured and correlated with glucose hypometabolism. Kinetic analysis of LEU uptake was performed in 4 patients. RESULTS Increased LEU standard uptake value (SUV, mean: 15.1%) was found in the angioma region in 6 patients, and smaller increases in LEU SUV (11.5%) were seen in frontal cortex in 4 of the 6 patients, despite normal glucose metabolism in frontal regions. High LEU SUV was due to both increased tracer transport (3/4 patients) and high protein synthesis rates (2/4). FDG SUV asymmetries in the angioma region were inversely related to LEU SUV asymmetries ( r =–.83, P = .042). CONCLUSIONS Increased amino acid uptake in the angioma region and also in less affected frontal regions may provide a marker of pathological mechanisms contributing to chronic brain damage in children with SWS. J Neuroimaging 2012;22:177‐183.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/91095/1/j.1552-6569.2010.00565.x.pd

    Genotype by environment interaction in Nelore cattle from five Brazilian states

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    Records from 75,941 Nelore cattle were used to determine the importance of genotype by environment interaction (GEI) in five Brazilian states. (Co)variance components were estimated by single-trait analysis (with yearling weight, W450, considered to be the same trait in all states) and multiple-trait analysis (with the record from each state considered to be a different trait). The direct heritability estimates for yearling weight were 0.51, 0.39, 0.44, 0.37 and 0.41 in the states of GoiĂĄs, Mato Grosso, SĂŁo Paulo, Mato Grosso do Sul and Minas Gerais, respectively. The across-state genetic correlation estimates between GoiĂĄs and Mato Grosso, GoiĂĄs and Minas Gerais, SĂŁo Paulo and Minas Gerais, and Mato Grosso do Sul and Minas Gerais ranged from 0.67 to 0.75. These estimates indicate that GEIs are biologically important. No interactions were observed between GoiĂĄs and SĂŁo Paulo, GoiĂĄs and Mato Grosso do Sul, Mato Grosso and SĂŁo Paulo, Mato Grosso and Mato Grosso do Sul, Mato Grosso and Minas Gerais, or SĂŁo Paulo and Mato Grosso do Sul (0.82 to 0.97). Comparison of single and multiple-trait analyses showed that selection based on the former was less efficient in the presence of GEI, with substantial losses (up to 10%) during selection

    Visual Analytics for Epidemiologists: Understanding the Interactions Between Age, Time, and Disease with Multi-Panel Graphs

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    Visual analytics, a technique aiding data analysis and decision making, is a novel tool that allows for a better understanding of the context of complex systems. Public health professionals can greatly benefit from this technique since context is integral in disease monitoring and biosurveillance. We propose a graphical tool that can reveal the distribution of an outcome by time and age simultaneously.We introduce and demonstrate multi-panel (MP) graphs applied in four different settings: U.S. national influenza-associated and salmonellosis-associated hospitalizations among the older adult population (≄65 years old), 1991-2004; confirmed salmonellosis cases reported to the Massachusetts Department of Public Health for the general population, 2004-2005; and asthma-associated hospital visits for children aged 0-18 at Milwaukee Children's Hospital of Wisconsin, 1997-2006. We illustrate trends and anomalies that otherwise would be obscured by traditional visualization techniques such as case pyramids and time-series plots.MP graphs can weave together two vital dynamics--temporality and demographics--that play important roles in the distribution and spread of diseases, making these graphs a powerful tool for public health and disease biosurveillance efforts

    Ultrafast Light and Electrons: Imaging the Invisible

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    In this chapter, the evolutionary and revolutionary developments of microscopic imaging are overviewed with focus on ultrashort light and electrons pulses; for simplicity, we shall use the term “ultrafast” for both. From Alhazen’s camera obscura, to Hooke and van Leeuwenhoek’s optical micrography, and on to three- and four-dimensional (4D) electron microscopy, the developments over a millennium have transformed humans’ scope of visualization. The changes in the length and time scales involved are unimaginable, beginning with the visible shadows of candles at the centimeter and second scales, and ending with invisible atoms with space and time dimensions of sub-nanometer and femtosecond, respectively. With these advances it has become possible to determine the structures of matter and to observe their elementary dynamics as they fold and unfold in real time, providing the means for visualizing materials behavior and biological function, with the aim of understanding emergent phenomena in complex systems. Both light and light-generated electrons are now at the forefront of femtosecond and attosecond science and technology, and the scope of applications has reached beyond the nuclear motion as electron dynamics become accessible
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