280 research outputs found
Comparison and Mapping Facilitate Relation Discovery and Predication
Relational concepts play a central role in human perception and cognition, but little is known about how they are acquired. For example, how do we come to understand that physical force is a higher-order multiplicative relation between mass and acceleration, or that two circles are the same-shape in the same way that two squares are? A recent model of relational learning, DORA (Discovery of Relations by Analogy; Doumas, Hummel & Sandhofer, 2008), predicts that comparison and analogical mapping play a central role in the discovery and predication of novel higher-order relations. We report two experiments testing and confirming this prediction
Performance of the CMS Cathode Strip Chambers with Cosmic Rays
The Cathode Strip Chambers (CSCs) constitute the primary muon tracking device
in the CMS endcaps. Their performance has been evaluated using data taken
during a cosmic ray run in fall 2008. Measured noise levels are low, with the
number of noisy channels well below 1%. Coordinate resolution was measured for
all types of chambers, and fall in the range 47 microns to 243 microns. The
efficiencies for local charged track triggers, for hit and for segments
reconstruction were measured, and are above 99%. The timing resolution per
layer is approximately 5 ns
Mitochondria and the regulation of free radical damage in the eye
Neuronal cell death can be determined by the overall level of reactive oxygen species (ROS) resulting from the combination of extrinsic sources and intrinsic production as a byproduct of oxidative phosphorylation. Key controllers of the intrinsic production of ROS are the mitochondrial uncoupling proteins (UCPs). By allowing a controlled leak of protons across the inner mitochondrial membrane activation of these proteins can decrease ROS and promote cell survival. In both primate models of Parkinson’s disease and mouse models of seizures, increased activity of UCP2 significantly increased neuronal cells survival. In the retina UCP2 is expressed in many neurons and glial cells, but was not detected in rod photoreceptors. Retinal ganglion cell survival following excitotoxic damage was much greater in animals overexpressing UCP2. Traditional Chinese medicines, such as an extract of Cistanche tubulosa, may provide benefit by altering mitochondrial metabolism
Copy number elevation of 22q11.2 genes arrests the developmental maturation of working memory capacity and adult hippocampal neurogenesis
Working memory capacity, a critical component of executive function, expands developmentally from childhood through adulthood. Anomalies in this developmental process are seen in individuals with autism spectrum disorder (ASD), schizophrenia and intellectual disabilities (ID), implicating this atypical process in the trajectory of developmental neuropsychiatric disorders. However, the cellular and neuronal substrates underlying this process are not understood. Duplication and triplication of copy number variants of 22q11.2 are consistently and robustly associated with cognitive deficits of ASD and ID in humans, and overexpression of small 22q11.2 segments recapitulates dimensional aspects of developmental neuropsychiatric disorders in mice. We capitalized on these two lines of evidence to delve into the cellular substrates for this atypical development of working memory. Using a region- and cell-type-selective gene expression approach, we demonstrated that copy number elevations of catechol-O-methyl-transferase (COMT) or Tbx1, two genes encoded in the two small 22q11.2 segments, in adult neural stem/progenitor cells in the hippocampus prevents the developmental maturation of working memory capacity in mice. Moreover, copy number elevations of COMT or Tbx1 reduced the proliferation of adult neural stem/progenitor cells in a cell-autonomous manner in vitro and migration of their progenies in the hippocampus granular layer in vivo. Our data provide evidence for the novel hypothesis that copy number elevations of these 22q11.2 genes alter the developmental trajectory of working memory capacity via suboptimal adult neurogenesis in the hippocampus.Peer reviewe
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Introduction
By highlighting relations between experimental and theoretical work, this volume explores new ways of addressing the problem of concept composition, which is one of the central challenges in the study of language and cognition. An introductory chapter lays out the background to the problem. The subsequent chapters by leading scholars and younger researchers in psychology, linguistics and philosophy, aim to explain how meanings of different complex expressions are derived from simple lexical concepts, and to analyze how these meanings connect to concept representations. This work demonstrates an important advance in the interdisciplinary study of concept composition, where points of convergence between cognitive psychology, linguistics and philosophy emerge and lead to new findings and theoretical insights
Identification and Filtering of Uncharacteristic Noise in the CMS Hadron Calorimeter
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Performance of CMS hadron calorimeter timing and synchronization using test beam, cosmic ray, and LHC beam data
This paper discusses the design and performance of the time measurement technique and of the synchronization systems of the CMS hadron calorimeter. Time measurement performance results are presented from test beam data taken in the years 2004 and 2006. For hadronic showers of energy greater than 100 GeV, the timing resolution is measured to be about 1.2 ns. Time synchronization and out-of-time background rejection results are presented from the Cosmic Run At Four Tesla and LHC beam runs taken in the Autumn of 2008. The inter-channel synchronization is measured to be within ±2 ns
Solution scanning as a key policy tool: Identifying management interventions to help maintain and enhance regulating ecosystem services
The major task of policy makers and practitioners when confronted with a resource management problem is to decide on the potential solution(s) to adopt from a range of available options. However, this process is unlikely to be successful and cost effective without access to an independently verified and comprehensive available list of options. There is currently burgeoning interest in ecosystem services and quantitative assessments of their importance and value. Recognition of the value of ecosystem services to human well-being represents an increasingly important argument for protecting and restoring the natural environment, alongside the moral and ethical justifications for conservation. As well as understanding the benefits of ecosystem services, it is also important to synthesize the practical interventions that are capable of maintaining and/or enhancing these services. Apart from pest regulation, pollination, and global climate regulation, this type of exercise has attracted relatively little attention. Through a systematic consultation exercise, we identify a candidate list of 296 possible interventions across the main regulating services of air quality regulation, climate regulation, water flow regulation, erosion regulation, water purification and waste treatment, disease regulation, pest regulation, pollination and natural hazard regulation. The range of interventions differs greatly between habitats and services depending upon the ease of manipulation and the level of research intensity. Some interventions have the potential to deliver benefits across a range of regulating services, especially those that reduce soil loss and maintain forest cover. Synthesis and applications: Solution scanning is important for questioning existing knowledge and identifying the range of options available to researchers and practitioners, as well as serving as the necessary basis for assessing cost effectiveness and guiding implementation strategies. We recommend that it become a routine part of decision making in all environmental policy areas. © 2014 by the author(s).The research was partly funded by RELU (RES 240-25-006), Arcadia,
NERC (Biodiversity and Ecosystem Service Sustainability
Directorate, NE/F01614X/1, NE/K001191/1 and NE/J500665/1),
SAPES (Multifunctional Agriculture: Harnessing Biodiversity for
Sustaining Agricultural Production and Ecosystem Services), and
FORMAS (the Swedish Research Council for Environment,
Agricultural Sciences and Spatial Planning)
Anisakidae and Raphidascarididae larvae parasitizing Selene setapinnis (Mitchill, 1815) in the State of Rio de Janeiro, Brazil
Between February and August, 2012, thirty specimens of Atlantic moonfish, Selene setapinnis, were purchased in local markets in Niterói, State of Rio de Janeiro, Brazil, with the aim of analyzing the presence of anisakid nematodes, establishing their rates of parasitism and infection sites, due to importance in the sanitary inspection. A total of sixty nematode larvae, belonging to at least two species were found: nine larvae of Terranova sp., Anisakidae, with prevalence (P) of 13.3%, mean intensity (MI) of 2.25, mean abundance (MA) of 0.30 and range of infection intensity (RI) from 1 to 6; and 51 larvae of Hysterothylaciumfortalezae, Raphidascarididae, with P = 26.7%, MI = 6.40, MA = 1.70, and RI = 1-17. The infection sites for Terranova sp. were the mesentery and liver serosa; and for H. fortalezae, the infection sites were the mesentery, abdominal cavity and liver serosa. New morphological data from scanning electron microscopy, on the external structures of H. fortalezae (mainly at the posterior end), are presented. This is the first report of H. fortalezae parasitizing S. setapinnis
Transport of Anthocyanins and other Flavonoids by the Arabidopsis ATP-Binding Cassette Transporter AtABCC2
Flavonoids have important developmental, physiological, and ecological roles in plants and are primarily stored in the large central vacuole. Here we show that both an ATP-binding cassette (ABC) transporter(s) and an H+-antiporter(s) are involved in the uptake of cyanidin 3-O-glucoside (C3G) by Arabidopsis vacuolar membrane-enriched vesicles. We also demonstrate that vesicles isolated from yeast expressing the ABC protein AtABCC2 are capable of MgATP-dependent uptake of C3G and other anthocyanins. The uptake of C3G by AtABCC2 depended on the co-transport of glutathione (GSH). C3G was not altered during transport and a GSH conjugate was not formed. Vesicles from yeast expressing AtABCC2 also transported flavone and flavonol glucosides. We performed ligand docking studies to a homology model of AtABCC2 and probed the putative binding sites of C3G and GSH through site-directed mutagenesis and functional studies. These studies identified residues important for substrate recognition and transport activity in AtABCC2, and suggest that C3G and GSH bind closely, mutually enhancing each other’s binding. In conclusion, we suggest that AtABCC2 along with possibly other ABCC proteins are involved in the vacuolar transport of anthocyanins and other flavonoids in the vegetative tissue of Arabidopsis
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