1,552 research outputs found

    ARCADE 3D-audio codec: an implementation for the web

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    This poster introduces the implementation of the ARCADE 3D audio codec for web browsers. ARCADE can embed a full 3D audio scene in a simple stereo-compatible audio stream that can be further compressed with standard lossy compression schemes, aired to analog or digital radio receivers or even stored on analog supports. An ARCADE-encoded stream can be decoded to any 2D or 3D-audio rendering format, for instance using Vector-Based Amplitude Panning (VBAP), Higher Order Ambisonics (HOA), or personalized binaural with head tracking. ARCADE adapts seamlessly to the audio industry needs, from storage to production, distribution/delivery, and rendering. It finds uses in Virtual or Augmented Reality (VR/AR), movies, gaming, music, telepresence & teleconferencing. We present a JavaScript (JS) and Web Audio API implementation of the ARCADE decoder, which was originally written in C++11, along with technical details of the porting operations. Live demos of 3D-audio content transmission, decoding and dynamic binaural rendering will be given during the poster session

    The electroretinographic diagnosis of the incomplete form of congenital stationary night blindness

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    AbstractFifteen patients with the incomplete form of congenital stationary night blindness (iCSNB) were reviewed to better characterize their electroretinographic (ERG) findings in view of differential diagnosis with other retinal conditions also presenting with negative bright-flash ERG responses. In all 15 patients, in dark-adapted conditions, the bright-flash ERG response had a normal a-wave followed by a subnormal b-wave. Oscillatory potentials (OPs) observed on the ascending limb of the b-wave, although delayed in implicit time, were of large amplitude. The response to a long-wavelength stimulus showed cone-related components and some well-delineated OPs. On the other hand, the photopically elicited cone responses were strongly abnormal, with a subnormal a-wave followed by a barely recordable b-wave. No OPs could be elicited under photopic conditions. The cone related components and the OP characteristics clearly distinguish iCSNB from the complete form of CSNB and other retinal conditions presenting with minimal fundus abnormalities but with negative bright-flash ERG responses, such as found in Duchenne muscular dystrophy and Ă…land Island eye disease. The severely abnormal post-synaptic components in the photopic recordings contrast with the well-differentiated cone activity evoked in scotopic conditions. We propose a cone system that does not respond optimally under the normal operating range (photopic) but rather under mesopic or scotopic conditions. In spite of the severe cone-ERG deficits, visual acuity was only slightly reduced. We propose that the defect, which interferes marginally with the neuronal flow of information, lies in the structures responsible for the building of the b-wave

    The Luminosity Function of Young Star Clusters In "The Antennae" Galaxies (NGC 4038/4039)

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    The WFPC2 of the HST has been used to obtain high-resolution images of NGC 4038/4039 that go roughly 3 magnitudes deeper in V than previous observations made during Cycle 2 (-14 < M_V < -6). To first order the luminosity function (LF) is a power law, with exponent \alpha = -2.12 +/- 0.04. However, after decoupling the cluster and stellar LFs, which overlap in the range -9 < M_V < -6, we find an apparent bend in the young cluster LF at approximately M_V = -10.4. The LF has a power law exponent -2.6 +/- 0.2 in the brightward and -1.7 +/- 0.2 in the faintward. The bend corresponds to a mass ~ 10^5 M_{\odot}, only slightly lower than the characteristic mass of globular clusters in the Milky Way (~2x10^5 M_{\odot}). The star clusters of the Antennae appear slightly resolved, with median effective radii of 4 +/- 1 pc, similar to or perhaps slightly larger than those of globular clusters in our Galaxy. However, the radial extents of some of the very young clusters (ages < 10 Myr) are much larger than those of old globular clusters. A combination of the UBVI colors, \Halpha morphology, and GHRS spectra enables us to age-date the clusters in different regions of The Antennae. We find two groups of young star clusters with ages <~ 20Myr and ~100Myr, as well as an intermediate-age group (~500 Myr) and a handful of old globular clusters from the progenitor galaxies. Age estimates derived from GHRS spectroscopy yield 3 +/- 1 Myr for Knot K (just south of the nucleus of NGC 4038) and 7 +/- 1 Myr for Knot S in the Western Loop, in good agreement with ages derived from the UBVI colors. Effective gas-outflow velocities from Knots S and K are estimated to be about 25-30 km/s. However, the measured widths of the interstellar absorption lines suggest dispersion velocities of ~400 km/s along the lines of sight to Knots S and K.Comment: 56 pages, 4 tables and 23 figures, texts in AAS style, to be published in A

    Impaired Expression of Neuregulin 1 and Nicotinic Acetylcholine Receptor β4 Subunit in Diverticular Disease

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    Neuregulin 1 (NRG1) regulates the expression of the nicotinic acetylcholine receptor (nAChR) and is suggested to promote the survival and maintenance of the enteric nervous system (ENS), since deficiency of its corresponding receptor complex ErbB2/ErbB3 leads to postnatal colonic aganglionosis. As diverticular disease (DD) is associated with intestinal hypoganglionosis, the NRG1-ErbB2/ErbB3 system and the nAChR were studied in patients with DD and controls. Samples of tunica muscularis of the sigmoid colon from patients with DD (n = 8) and controls (n = 11) were assessed for mRNA expression of NRG1, ErbB2, and ErbB3 and the nAChR subunits α3, α5, α7, β2, and β4. Site-specific gene expression levels of the NRG1-ErbB2/3 system were determined in myenteric ganglia harvested by laser microdissection (LMD). Localization studies were performed by immunohistochemistry for the NRG1-ErbB2/3 system and nAChR subunit β4. Rat enteric nerve cell cultures were stimulated with NRG1 or glial-cell line derived neurotrophic factor (GDNF) for 6 days and mRNA expression of the aforementioned nAchR was measured. NRG1, ErbB3, and nAChR subunit β4 expression was significantly down-regulated in both the tunica muscularis and myenteric ganglia of patients with DD compared to controls, whereas mRNA expression of ErbB3 and nAChR subunits β2, α3, α5, and α7 remained unaltered. NRG1, ErbB3, and nAChR subunit β4 immunoreactive signals were reduced in neuronal somata and the neuropil of myenteric ganglia from patients with DD compared to control. nAChR subunit β4 exhibited also weaker immunoreactive signals in the tunica muscularis of patients with DD. NRG1 treatment but not GDNF treatment of enteric nerve cell cultures significantly enhanced mRNA expression of nAchR β4. The down-regulation of NRG1 and ErbB3 in myenteric ganglia of patients with DD supports the hypothesis that intestinal hypoganglionosis observed in DD may be attributed to a lack of neurotrophic factors. Regulation of nAChR subunit β4 by NRG1 and decreased nAChR β4 in patients with DD provide evidence that a lack of NRG1 may affect the composition of enteric neurotransmitter receptor subunits thus contributing to the intestinal motility disorders previously reported in DD

    Heat pump integration in a cheese factory

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    The aim of this work is to increase the efficiency of industrial processes by using pinch analysis and process design methods. The main goals are the reduction of energy consumption, of the corresponding operating costs and of CO2 emissions. In this context heat pumps offer promising opportunities, when they are appropriately integrated into the process. Two different integration strategies can be applied: In a first approach, process modifications are not allowed whereas in a second approach it is possible to modify process units. It is shown that industrial and practical decisions have a big influence on the final choice of new equipments. The presented method is applied to a real case study in a cheese factory where both approaches are applied and compared. The results from the energy integration are analyzed and assessed with the practical feasibility of solutions

    Ablation of hepatocellular carcinoma by percutaneous ethanol injection: Imaging findings

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    Summary: Since PEI is a treatment based on imaging techniques, the radiologist should be familiar with the various findings that may be observed after PEI on US, CT, and MR images immediately after treatment and during later follow-up. Although US is well suited for performing PEI, contrast-enhanced CT currently is the most commonly used imaging method to evaluate the effect of PEI. Residual, nodular areas of contrast enhancement correlate well with residual tumor and warrant additional treatment. Although the findings on MR images obtained after PEI are more complex, MR imaging may be used as an alternative to C

    Utility Optimization in a Brewery Process Based on Energy Integration Methodology

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    This paper presents a methodology aimed at improving the energy efficiency of a brewery applying process integration techniques. The different steps of the analysis are presented. The first step is the identification of the process energy requirements and the corresponding heat loads, which allows the definition of the process hot and cold streams. The Pinch Analysis of the brewery reveals a heat recovery potential of 36% by improving the heat exchanger system. In order to satisfy the minimum energy requirements, optimal energy conversion technology configurations are calculated, taking into account economic and environmental criteria. The integration of suitable utilities is considered (cogeneration engine combined with heat pumping and refrigeration systems) and the interaction between them is analyzed. In addition, a thermo-economic optimization is performed in order to determine the optimal heat pump operating temperatures. The results show the opportunity to reduce by 36% the brewery heating bill and by 44% the CO2 emissions through the set up of an optimized utility configuration when compared to the current one. In addition, the optimal integration shows that the cooling water consumption of the refrigeration can be suppressed and appropriately be replaced by a heat pumping effect. The comparison between French and German conditions shows that contrasting results can be obtained due to the different economic and energy supply configurations. The process system analysis shows that when considering the recovery of the plant organic waste, bio-methane can be produced and valorized in the cogeneration engine. In that case, it is demonstrated that the process can become self sufficient in terms of energy

    Feature tracking strain analysis detects the onset of regional diastolic dysfunction in territories with acute myocardial injury induced by transthoracic electrical interventions.

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    Electric interventions are used to terminate arrhythmia. However, myocardial injury from the electrical intervention can follow unique pathways and it is unknown how this affects regional ventricular function. This study investigated the impact of transthoracic electrical shocks on systolic and diastolic myocardial deformation. Ten healthy anaesthetized female swine received five transthoracic shocks (5 × 200 J) and six controls underwent a cardiovascular magnetic resonance exam prior to and 5 h after the intervention. Serial transthoracic shocks led to a global reduction in both left (LV, - 15.6 ± 3.3% to - 13.0 ± 3.6%, p < 0.01) and right ventricular (RV, - 16.1 ± 2.3% to - 12.8 ± 4.2%, p = 0.03) peak circumferential strain as a marker of systolic function and to a decrease in LV early diastolic strain rate (1.19 ± 0.35/s to 0.95 ± 0.37/s, p = 0.02), assessed by feature tracking analysis. The extent of myocardial edema (ΔT1) was related to an aggravation of regional LV and RV diastolic dysfunction, whereas only RV systolic function was regionally associated with an increase in T1. In conclusion, serial transthoracic shocks in a healthy swine model attenuate biventricular systolic function, but it is the acute development of regional diastolic dysfunction that is associated with the onset of colocalized myocardial edema
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