666 research outputs found

    Regional differentiation of neuron morphology in human left and right hippocampus: Comparing normal to schizophrenia

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    Regional differentiation based on size, form, and orientation angle of the soma of individual neurons in human post-mortem hippocampus was determined through correlations between pairs of hippocampal subfields in each side separately. The neurons were previously measured on a computer. In the normal cases, a left-right asymmetrical pattern of regional differentiation based on soma size emerged, while for form and orientation angle, the patterns appeared symmetrical. In schizophrenia, regional soma size, form, and orientation variability were expressed largely symmetrically. Regional correlations based on neuronal density revealed an asymmetrical hemispheric pattern in the normal cases versus a nearly symmetrical pattern in schizophrenia. Taken together, the inter-regional correlations favor a hippocampal landscape that deviates in each side from connectivity based on the canonical trisynaptic hippocampal circuitry. It is proposed that during morphogenesis, rudimentary inter-regional networks are formed through specific interactions between regional neurons; these networks are present in the adult hippocampus and may be vulnerable in brain diseases

    Appearance of symmetry, beauty, and health in human faces

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    Symmetry is an important concept in biology, being related to mate selection strategies, health, and survival of species. In human faces, the relevance of left-right symmetry to attractiveness and health is not well understood. We compared the appearance of facial attractiveness, health, and symmetry in three separate experiments. Participants inspected front views of faces on the computer screen and judged them on a 5-point scale according to their attractiveness in Experiment 1, health in Experiment 2, and symmetry in Experiment 3. We found that symmetry and attractiveness were not strongly related in faces of women or men while health and symmetry were related. There was a significant difference between attractiveness and symmetry judgments but not between health and symmetry judgments. Moreover, there was a significant difference between attractiveness and health. Facial symmetry may be critical for the appearance of health but it does not seem to be critical for the appearance of attractiveness, not surprisingly perhaps because human faces together with the human brain have been shaped by adaptive evolution to be naturally asymmetrical

    Where does brain neural activation in aesthetic responses to visual art occur? Meta-analytic evidence from neuroimaging studies

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    Here we aimed at finding the neural correlates of the general aspect of visual aesthetic experience (VAE) and those more strictly correlated with the content of the artworks. We applied a general activation likelihood estimation (ALE) meta-analysis to 47 fMRI experiments described in 14 published studies. We also performed four separate ALE analyses in order to identify the neural substrates of reactions to specific categories of artworks, namely portraits, representation of real-world-visual-scenes, abstract paintings, and body sculptures. The general ALE revealed that VAE relies on a bilateral network of areas, and the individual ALE analyses revealed different maximal activation for the artworks' categories as function of their content. Specifically, different content-dependent areas of the ventral visual stream are involved in VAE, but a few additional brain areas are involved as well. Thus, aesthetic-related neural responses to art recruit widely distributed networks in both hemispheres including content-dependent brain areas of the ventral visual stream. Together, the results suggest that aesthetic responses are not independent of sensory, perceptual, and cognitive processe

    Mountain-Shaped Coupler for Ultra Wideband Applications

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    This paper demonstrates a novel mountain-shaped design for a compact 3-dB coupler operating at ultra-wideband (UWB) frequencies from 3.1GHz to 10.6 GHz. The proposed design was accomplished using multilayer technology in which the structure is formed by three layers of conductors interleaved by a layer of substrate between each conductor layer. Simulation was carried out using CST Microwave Studio; the result was then compared with results from rectangular and star-shaped couplers that implemented the same technique. The results obtained show that the proposed new coupler has better performance compared to both rectangular and star-shaped coupler designs in terms of return loss, isolation, and phase difference. The coupler was fabricated and measured; the measurement results satisfactorily agree with the simulation results

    Compact wideband broadside-coupled microstrip-slot bandpass filter for communication applications

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    This paper proposes a compact size design of wideband bandpass filter (BPF). The broad-side coupling microstrip-slot technique is used to accomplish a good passband response with very low insertion loss across a wideband frequency range. The BPF that is designed using Rogers RO4003C substrate shows a good performance with the respective maximum reflection coefficient and insertion loss of -10 dB and 1.2 dB between 0.92 GHz and 5 GHz. This type of BPF filter is useful in any communication applications

    Reducing bias in auditory duration reproduction by integrating the reproduced signal

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    Duration estimation is known to be far from veridical and to differ for sensory estimates and motor reproduction. To investigate how these differential estimates are integrated for estimating or reproducing a duration and to examine sensorimotor biases in duration comparison and reproduction tasks, we compared estimation biases and variances among three different duration estimation tasks: perceptual comparison, motor reproduction, and auditory reproduction (i.e. a combined perceptual-motor task). We found consistent overestimation in both motor and perceptual-motor auditory reproduction tasks, and the least overestimation in the comparison task. More interestingly, compared to pure motor reproduction, the overestimation bias was reduced in the auditory reproduction task, due to the additional reproduced auditory signal. We further manipulated the signal-to-noise ratio (SNR) in the feedback/comparison tones to examine the changes in estimation biases and variances. Considering perceptual and motor biases as two independent components, we applied the reliability-based model, which successfully predicted the biases in auditory reproduction. Our findings thus provide behavioral evidence of how the brain combines motor and perceptual information together to reduce duration estimation biases and improve estimation reliability

    Antioxidant properties of rice bran oil from different varieties extracted by solvent extraction methods

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    Antioxidant properties of rice bran oil from different rice bran varieties; Rice Bran-Bario (RB-Bario), Rice bran-Lowland (RB-Low) and Rice Bran- Upland rice (RB-Up), collected from different cultural plots, were assessed. Measurement of antioxidant properties was evaluated by TPC (total phenolic content), DPPH scavenging activities and reducing power of extracts.. The study shows that antioxidant efficacy of rice bran was found the highest in RB-Up, followed by RB- Low and RB-Bario. The antioxidant properties were related to the rice bran origin and water irrigation demand by particular variety. RB –Up has a unique plantation condition which takes least amount of water retention which contribute to the highest antioxidant activity. Extraction solvents used shows that Upland (16.15%) and Lowland (16.16%) yielded the highest amount in conserving the crude fat oil in rice bran extract compared to Bario

    Hemispheric effects of canonical views of category members with known typicality levels

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    Is there a preferred hemispheric canonical view of a visual concept? We investigated this question in a natural superordinate category membership decision task using a hemi-field paradigm. Participants had to decide whether or not an image of an object lateralized in the left (LVF) or right (RVF) visual half field is a member of a predesignated superordinate category. The objects represented high, medium, or low typicality levels, and each object had 6 different perspective views (front, front-right, front-left, side, back-left, and back-right). The latency responses revealed a significant interaction of Hemi Field X View X Typicality (there was no hemi-field difference in accuracy). The findings confirm the presence of asymmetry in stored concepts in long-term memory and suggest, in addition, a hemispheric canonical view of these concepts, a view strongly related to typicality level

    Design, Construction, Operation and Performance of a Hadron Blind Detector for the PHENIX Experiment

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    A Hadron Blind Detector (HBD) has been developed, constructed and successfully operated within the PHENIX detector at RHIC. The HBD is a Cherenkov detector operated with pure CF4. It has a 50 cm long radiator directly coupled in a window- less configuration to a readout element consisting of a triple GEM stack, with a CsI photocathode evaporated on the top surface of the top GEM and pad readout at the bottom of the stack. This paper gives a comprehensive account of the construction, operation and in-beam performance of the detector.Comment: 51 pages, 39 Figures, submitted to Nuclear Instruments and Method
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