6,975 research outputs found

    A resonance interpretation for the nonmonotonic behavior of the phi-photoproduction cross section near threshold

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    We study whether the nonmonotonic behavior found in the differential cross section of the phi-meson photoproduction near threshold can be described by a resonance. The resonant contribution is evaluated by using an effective Lagrangian approach. We find that, with the assumption of a J^P=3/2^- resonance with mass of 2.10 \pm 0.03 GeV and width of 0.465 \pm 0.141 GeV, LEPS data can indeed be well described. The ratio of the helicity amplitudes A_1/2/A_3/2 calculated from the resulting coupling constants differs in sign from that of the known D13(2080). We further find that the addition of this postulated resonance can substantially improve the agreement between the existing theoretical predictions and the recent omega photoproduction data if a large value of the OZI evading parameter x_OZI = 12 is assumed for the resonance.Comment: Contribution to the Proceedings of BARYONS'10 - International conference on the structure of baryons, Dec. 7-11, 2010, Osaka, Japa

    Increased neuroinflammatory signaling and memory deficits caused by early-life ethanol exposure and the potential benefits of anti-inflammatory treatment

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    Alcohol consumption during pregnancy can lead to physical irregularities and deficits in cognition collectively known as fetal alcohol spectrum disorders (FASD). Impairments in cognition, particularly hippocampus-dependent memory, may be due to ethanol-induced neuroinflammation resulting from third trimester alcohol consumption, a period of development in which the brain undergoes rapid growth and synaptogenesis. This study utilized a third trimester binge-drinking rodent model of FASD, in which rats were intubated and given ethanol (5g/kg/day; 5E) or sham intubated (SI) over postnatal days (PD)4-9. The ability of two anti-inflammatory drugs, ibuprofen and glycyrrhizin, to normalize neuroinflammation and cognition were investigated. Animals in the ibuprofen group received subcutaneous injections 2h following ethanol treatment (100mg/kg on PD4, 50mg/kg/day following, IBU) or an equivalent volume of PBS (vehicle; VEH). Glycyrrhizin animals received the drug (20mg/kg/day; GLY) or an equivalent volume of VEH via intraperitoneal injections 20-30min prior to ethanol administration. On PD10 the rats were euthanized and hippocampi removed for quantification of inflammation-related gene expression. In the IBU experiment, but not the GLY experiment, the 5E-VEH rats showed significant increases in hippocampal IL-1β and TNF-α, but not CD11B or GFAP, expression compared to SI-VEH and 5E-IBU. Next, we assessed in juvenile 5E rats whether ibuprofen or glycyrrhizin could rescue previously documented deficits in Trace Fear Conditioning (TFC), a challenging hippocampus-dependent associative memory task. Results indicate IBU but not GLY rescued TFC test performance in 5E rats. Taken together, postnatal ethanol upregulated pro-inflammatory cytokine expression on PD10 and impaired TFC over PD31-33. Ibuprofen, but not glycyrrhizin, ameliorated both effects, suggesting the potential benefits of anti-inflammatory drug treatment in improving cognition in FASD individuals.Arts & Sciences Undergraduate Research ScholarshipSocial and Behavioral Sciences Undergraduate Research GrantNo embargoAcademic Major: Neuroscienc

    Longest segment of balanced parentheses -- an exercise in program inversion in a segment problem (Functional Pearl)

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    Given a string of parentheses, the task is to find the longest consecutive segment that is balanced, in linear time. We find this problem interesting because it involves a combination of techniques: the usual approach for solving segment problems, and a theorem for constructing the inverse of a function -- through which we derive an instance of shift-reduce parsing

    Electro-optic properties of a homeotropic liquid crystal cell with 90 degrees surface rubbings and a reverse-handed chiral dopant

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    The electro-optic properties of a 90 degrees twisted-homeotropic liquid crystal (LC) cell with a chiral dopant whose handedness is opposite to the LC twist are studied. In the voltage-off state, the LC directors exhibit a homeotropic alignment. However, in the intermediate voltage state, the bulk LC directors behave like a homogeneous alignment due to the balanced torques between the electric field, surface anchoring, and reversed chiral dopant. Potential applications of this mode for liquid crystal displays, especially for dual-cell-gap transflective liquid crystal displays, are emphasized

    Vision based interface system for hands free control of an intelligent wheelchair

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    <p>Abstract</p> <p>Background</p> <p>Due to the shift of the age structure in today's populations, the necessities for developing the devices or technologies to support them have been increasing. Traditionally, the wheelchair, including powered and manual ones, is the most popular and important rehabilitation/assistive device for the disabled and the elderly. However, it is still highly restricted especially for severely disabled. As a solution to this, the Intelligent Wheelchairs (IWs) have received considerable attention as mobility aids. The purpose of this work is to develop the IW interface for providing more convenient and efficient interface to the people the disability in their limbs.</p> <p>Methods</p> <p>This paper proposes an intelligent wheelchair (IW) control system for the people with various disabilities. To facilitate a wide variety of user abilities, the proposed system involves the use of face-inclination and mouth-shape information, where the direction of an IW is determined by the inclination of the user's face, while proceeding and stopping are determined by the shapes of the user's mouth. Our system is composed of electric powered wheelchair, data acquisition board, ultrasonic/infra-red sensors, a PC camera, and vision system. Then the vision system to analyze user's gestures is performed by three stages: detector, recognizer, and converter. In the detector, the facial region of the intended user is first obtained using Adaboost, thereafter the mouth region is detected based on edge information. The extracted features are sent to the recognizer, which recognizes the face inclination and mouth shape using statistical analysis and <it>K</it>-means clustering, respectively. These recognition results are then delivered to the converter to control the wheelchair.</p> <p>Result & conclusion</p> <p>The advantages of the proposed system include 1) accurate recognition of user's intention with minimal user motion and 2) robustness to a cluttered background and the time-varying illumination. To prove these advantages, the proposed system was tested with 34 users in indoor and outdoor environments and the results were compared with those of other systems, then the results showed that the proposed system has superior performance to other systems in terms of speed and accuracy. Therefore, it is proved that proposed system provided a friendly and convenient interface to the severely disabled people.</p

    Two Methods for Spoofing-Aware Speaker Verification: Multi-Layer Perceptron Score Fusion Model and Integrated Embedding Projector

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    The use of deep neural networks (DNN) has dramatically elevated the performance of automatic speaker verification (ASV) over the last decade. However, ASV systems can be easily neutralized by spoofing attacks. Therefore, the Spoofing-Aware Speaker Verification (SASV) challenge is designed and held to promote development of systems that can perform ASV considering spoofing attacks by integrating ASV and spoofing countermeasure (CM) systems. In this paper, we propose two back-end systems: multi-layer perceptron score fusion model (MSFM) and integrated embedding projector (IEP). The MSFM, score fusion back-end system, derived SASV score utilizing ASV and CM scores and embeddings. On the other hand,IEP combines ASV and CM embeddings into SASV embedding and calculates final SASV score based on the cosine similarity. We effectively integrated ASV and CM systems through proposed MSFM and IEP and achieved the SASV equal error rates 0.56%, 1.32% on the official evaluation trials of the SASV 2022 challenge.Comment: 5 pages, 4 figures, 5 tables, accepted to 2022 Interspeech as a conference pape
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