6,288 research outputs found

    Engaging the articulators enhances perception of concordant visible speech movements

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    PURPOSE This study aimed to test whether (and how) somatosensory feedback signals from the vocal tract affect concurrent unimodal visual speech perception. METHOD Participants discriminated pairs of silent visual utterances of vowels under 3 experimental conditions: (a) normal (baseline) and while holding either (b) a bite block or (c) a lip tube in their mouths. To test the specificity of somatosensory-visual interactions during perception, we assessed discrimination of vowel contrasts optically distinguished based on their mandibular (English /ɛ/-/æ/) or labial (English /u/-French /u/) postures. In addition, we assessed perception of each contrast using dynamically articulating videos and static (single-frame) images of each gesture (at vowel midpoint). RESULTS Engaging the jaw selectively facilitated perception of the dynamic gestures optically distinct in terms of jaw height, whereas engaging the lips selectively facilitated perception of the dynamic gestures optically distinct in terms of their degree of lip compression and protrusion. Thus, participants perceived visible speech movements in relation to the configuration and shape of their own vocal tract (and possibly their ability to produce covert vowel production-like movements). In contrast, engaging the articulators had no effect when the speaking faces did not move, suggesting that the somatosensory inputs affected perception of time-varying kinematic information rather than changes in target (movement end point) mouth shapes. CONCLUSIONS These findings suggest that orofacial somatosensory inputs associated with speech production prime premotor and somatosensory brain regions involved in the sensorimotor control of speech, thereby facilitating perception of concordant visible speech movements. SUPPLEMENTAL MATERIAL https://doi.org/10.23641/asha.9911846R01 DC002852 - NIDCD NIH HHSAccepted manuscrip

    The effect of combined glutamate receptor blockade in the NTS on the hypoxic ventilatory response in awake rats differs from the effect of individual glutamate receptor blockade.

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    Ventilatory acclimatization to hypoxia (VAH) increases the hypoxic ventilatory response (HVR) and causes persistent hyperventilation when normoxia is restored, which is consistent with the occurrence of synaptic plasticity in acclimatized animals. Recently, we demonstrated that antagonism of individual glutamate receptor types (GluRs) within the nucleus tractus solitarii (NTS) modifies this plasticity and VAH (J. Physiol. 592(8):1839-1856); however, the effects of combined GluR antagonism remain unknown in awake rats. To evaluate this, we exposed rats to room air or chronic sustained hypobaric hypoxia (CSH, PiO2 = 70 Torr) for 7-9 days. On the experimental day, we microinjected artificial cerebrospinal fluid (ACSF: sham) and then a "cocktail" of the GluR antagonists MK-801 and DNQX into the NTS. The location of injection sites in the NTS was confirmed by glutamate injections on a day before the experiment and with histology following the experiment. Ventilation was measured in awake, unrestrained rats breathing normoxia or acute hypoxia (10% O2) in 15-min intervals using barometric pressure plethysmography. In control (CON) rats, acute hypoxia increased ventilation; NTS microinjections of GluR antagonists, but not ACSF, significantly decreased ventilation and breathing frequency in acute hypoxia but not normoxia (P < 0.05). CSH increased ventilation in hypoxia and acute normoxia. In CSH-conditioned rats, GluR antagonists in the NTS significantly decreased ventilation in normoxia and breathing frequency in hypoxia. A persistent HVR after combined GluR blockade in the NTS contrasts with the effect of individual GluR blockade and also with results in anesthetized rats. Our findings support the hypotheses that GluRs in the NTS contribute to, but cannot completely explain, VAH in awake rats

    ASSESSING THE EFFECT OF ECR ON FINANCIAL AND OPERATING PERFORMANCE

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    A debate has emerged in the literature and trade press whether the adoption of Efficient Consumer Response (ECR), the supply chain management initiatives for the food industry, leads to improved inventory and financial performance. Using regression analysis, the financial performance for adopters of ECR is about 3 to 4% higher than for non-adopters. However, the growth in profit does not appear to come from improved performance for traditional inventory measures (such as inventory turnover, inventory-to-sales, or inventory-to-assets). The driving force behind these improved financial measures can be attributed to changes leading to a shorter cash conversion cycle. In addition, size matters; ECR is more effective due to economies of scale, information technology, and buying power.Industrial Organization,

    Primary Blast Traumatic Brain Injury in the Rat: Relating Diffusion Tensor Imaging and Behavior

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    The incidence of traumatic brain injury (TBI) among military personnel is at its highest point in U.S. history. Experimental animal models of blast have provided a wealth of insight into blast injury. The mechanisms of neurotrauma caused by blast, however, are still under debate. Specifically, it is unclear whether the blast shockwave in the absence of head motion is sufficient to induce brain trauma. In this study, the consequences of blast injury were investigated in a rat model of primary blast TBI. Animals were exposed to blast shockwaves with peak reflected overpressures of either 100 or 450 kPa (39 and 110 kPa incident pressure, respectively) and subsequently underwent a battery of behavioral tests. Diffusion tensor imaging (DTI), a promising method to detect blast injury in humans, was performed on fixed brains to detect and visualize the spatial dependence of blast injury. Blast TBI caused significant deficits in memory function as evidenced by the Morris Water Maze, but limited emotional deficits as evidenced by the Open Field Test and Elevated Plus Maze. Fractional anisotropy, a metric derived from DTI, revealed significant brain abnormalities in blast-exposed animals. A significant relationship between memory deficits and brain microstructure was evident in the hippocampus, consistent with its role in memory function. The results provide fundamental insight into the neurological consequences of blast TBI, including the evolution of injury during the sub-acute phase and the spatially dependent pattern of injury. The relationship between memory dysfunction and microstructural brain abnormalities may provide insight into the persistent cognitive difficulties experienced by soldiers exposed to blast neurotrauma and may be important to guide therapeutic and rehabilitative efforts

    Natural product libraries: Assembly, maintenance, and screening

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    This review discusses successful strategies and potential pitfalls to assembling a natural product-based library suitable for high-throughput screening. Specific extraction methods for plants, microorganisms, and marine invertebrates are detailed, along with methods for generating a fractionated sub-library. The best methods to store, maintain and prepare the library for screening are addressed, as well as recommendations on how to develop a robust high-throughput assay. Finally, the logistics of moving from an assay hit to pure bioactive compound are discussed

    Reliability of Smartphone Inclinometry to Measure Upper Cervical Range of Motion.

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    Context: Assessment of upper cervical range of motion (UCROM) and mobility is commonly performed in the clinical setting for patients suffering from headache, neck pain and vestibular dysfunction. Reliable and reproducible measurement of this motion is often difficult or too expensive to perform in the clinical setting. Smartphone applications, utilizing the device\u27s internal gyroscope, offer an easy and inexpensive means of measuring UCROM, but their reliability has not been reported in the literature. Objective: Assess the reliability of an inclinometer application, installed on two different devices (iPhone6 (IP), Andriod (AN)), to measure UCROM in a healthy population. Design: Two examiners assessed passive UCROM. Each examiner was assigned to a specific smartphone and a repeated measures design consisting of three trials for each examiner-phone was performed. The order of testing was randomized and the examiners were blinded to UCROM measures. Setting: Laboratory Participants: 38 subjects (19F, 19M; 23.8±1.2 yrs) without pain or injury to the neck and spine for at least 3 months. Intervention: Each examiner passively flexed the head fully and then rotated the head fully in one direction then in another. Peak rotation measures were recorded from each smartphone. Three trials were performed for each phone with a 2-minute break between examiners/phones. Main Outcome Measures: Intraclass Correlation Coefficient (ICC) using a two way mixed, absolute agreement model were obtained (1) between each examiner-phone and (2) within each examiner-phone for the measurements in each rotation direction. Results: Inter-phone/examiner reliability comparing average peak and total UCROM for each device were excellent (0.87, 0.81). Intra-phone/examiner reliability, determined across three trials, was also excellent (AN Right Rot. = 0.91, AN Left Rot. 0.96, IP Right Rot. = 0.98, IP Left = 0.95 Rot.). Conclusion: UCROM can be reliably measured using a smartphone inclinometer application
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