393 research outputs found

    1Mbps is enough: video quality and individual idiosyncrasies in multiparty HD video-conferencing

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    Most video platforms deliver HD video in high bitrate encoding. Modern video-conferencing systems are capable of handling HD streams, but using multiparty conferencing, average internet connections in the home are on their bandwidth limit. For properly managing the encoding bitrate in videoconferencing, we must know what is the minimum bitrate requirement to provide users an acceptable experience, and what is the bitrate level after which QoE saturates?. Most available subjective studies in this area used rather dated technologies. We report on a multiparty study on video quality with HD resolution. We tested different encoding bitrates (256kbs, 1024kbs and 4096kbs) and packet loss rates (0, 0.5%) in groups of 4 participants with a

    Influence of applying different units of measurement on reporting antimicrobial consumption data for pig farms

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    Background: Antimicrobial use in livestock is one of the factors contributing to selection and spread of resistant microorganisms in the environment. National ve

    Thin-Film Metamaterials called Sculptured Thin Films

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    Morphology and performance are conjointed attributes of metamaterials, of which sculptured thin films (STFs) are examples. STFs are assemblies of nanowires that can be fabricated from many different materials, typically via physical vapor deposition onto rotating substrates. The curvilinear--nanowire morphology of STFs is determined by the substrate motions during fabrication. The optical properties, especially, can be tailored by varying the morphology of STFs. In many cases prototype devices have been fabricated for various optical, thermal, chemical, and biological applications.Comment: to be published in Proc. ICTP School on Metamaterials (Augsut 2009, Sibiu, Romania

    Neural correlates of anxious distress in depression:A neuroimaging study of reactivity to emotional faces and resting-state functional connectivity

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    Background: Comorbid anxiety disorders and anxious distress are highly prevalent in major depressive disorder (MDD). The presence of the DSM-5 anxious distress specifier (ADS) has been associated with worse treatment outcomes and chronic disease course. However, little is known about the neurobiological correlates of anxious distress in MDD. Methods: We probed the relation between the DSM-5 ADS and task-related reactivity to emotional faces, as well as resting-state functional connectivity patterns of intrinsic salience and basal ganglia networks in unmedicated MDD patients with (MDD/ADS+, N = 24) and without ADS (MDD/ADS−, N = 48) and healthy controls (HC, N = 59). Both categorical and dimensional measures of ADS were investigated. Results: MDD/ADS+ patients had higher left amygdala responses to emotional faces compared to MDD/ADS− patients (p =.015)—part of a larger striato-limbic cluster. MDD/ADS+ did not differ from MDD/ADS− or controls in resting-state functional connectivity of the salience or basal ganglia networks. Conclusions: Current findings suggest that amygdala and striato-limbic hyperactivity to emotional faces may be a neurobiological hallmark specific to MDD with anxious distress, relative to MDD without anxious distress. This may provide preliminary indications of the underlying mechanisms of anxious distress in depression, and underline the importance to account for heterogeneity in depression research

    The occurrence of adverse events in low-risk non-survivors in pediatric intensive care patients: an exploratory study

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    We studied the occurrence of adverse events (AEs) in low-risk non-survivors (LNs), compared to low-risk survivors (LSs), high-risk non-survivors (HNs), and high-risk survivors (HSs) in two pediatric intensive care units (PICUs). The study was performed as a retrospective patient record review study, using a PICU-trigger tool. A random sample of 48 PICU patients (0–18 years) was chosen, stratified into four subgroups of 12 patients: LNs, LSs, HNs, and HSs. Primary outcome was the occurrence of AEs. The severity, preventability, and nature of the indentified AEs were determined. In total, 45 AEs were found in 20 patients. The occurrence of AEs in the LN group was significantly higher compared to that in the LS group and HN group (AE occurrence: LN 10/12 patients, LS 1/12 patients; HN 2/12 patients; HS 7/12 patients; LN-LS difference, p < 0.001; LN-HN difference, p < 0.01). The AE rate in the LN group was significantly higher compared to that in the LS and HN groups (median [IQR]: LN 0.12 [0.07–0.29], LS 0 [0–0], HN 0 [0–0], and HS 0.03 [0.0–0.17] AE/PICU day; LN-LS difference, p < 0.001; LN-HN difference, p < 0.01). The distribution of the AEs among the four groups was as follows: 25 AEs (LN), 2 AEs (LS), 8 AEs (HN), and 10 AEs (HS). Fifteen of forty-five AEs were preventable. In 2/12 LN patients, death occurred after a preventable AE. Conclusion: The occurrence of AEs in LNs was higher compared to that in LSs and HNs. Some AEs were severe and preventable and contributed to mortality.(Table presented.

    A new in vivo screening model for posterior spinal bone formation: comparison of ten calcium phosphate ceramic material treatments

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    This study presents a new screening model for evaluating the influence of multiple conditions on the initial process of bone formation in the posterior lumbar spine of a large animal. This model uses cages designed for placement on the decorticated transverse process of the goat lumbar spine. Five conduction channels per cage, each be defined by a different material treatment, are open to both the underlying bone and overlying soft tissue. The model was validated in ten adult Dutch milk goats, with each animal implanted with two cages containing a total of ten calcium phosphate material treatments according to a randomized complete block design. The ten calcium phosphate ceramic materials were created through a combination of material chemistry (BCP, TCP, HA), sintering temperature (low, medium, high), calcination and surface roughness treatments. To monitor the bone formation over time, fluorochrome markers were administered at 3, 5 and 7 weeks and the animals were sacrificed at 9 weeks after implantation. Bone formation in the conduction channels was investigated by histology and histomorphometry of non-decalcified sections using traditional light and epifluorescent microscopy. According to both observed and measured bone formation parameters, materials were ranked in order of increasing magnitude as follows: low sintering temperature BCP (rough and smooth)≈medium sintering temperature BCP≈TCP>calcined low sintering temperature HA>non-calcined low sintering temperature HA>high sintering temperature BCP (rough and smooth)>high sintering temperature HA (calcined and non-calcined). These results agree closely with those obtained in previous studies of osteoconduction and bioactivity of ceramics thereby validating the screening model presented in this study

    An insulin receptor mutant (Asp707 → Ala), involved in leprechaunism, is processed and transported to the cell surface but unable to bind insulin

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    We have identified a homozygous mutation near the carboxyl terminus of the insulin receptor (IR) α subunit from a leprechaun patient, changing Asp707 into Ala. Fibroblasts from this patient had no high affinity insulin binding sites. To examine the effect of the mutation on IR properties, the mutant IR was stably expressed in Chinese hamster ovary cells. Western blot analysis and metabolic labeling showed a normal processing of the mutant receptor to α and β subunits. No increase in high affinity insulin binding sites was observed on Chinese hamster ovary cells expressing the mutant receptor, and also, affinity cross-linking of 125I- labeled insulin by disuccinimidyl suberate to these cells failed to label the mutant α subunit. Biotinylation of cell surface proteins by biotin succinimidyl ester resulted in efficient biotinylation of the mutant IR α and β subunits, showing its presence on the cell surface. On solubilization of the mutant insulin receptor in Triton X. 100-containing buffers, 125I- insulin was efficiently cross-linked to the receptor a subunit by disuccinimidyl suberate. These studies demonstrate that Ala707 IR is normally processed and transported to the cell surface and that the mutation distorts the insulin binding site. Detergent restores this site. This is an example of a naturally occurring mutation in the insulin receptor that affects insulin binding without affecting receptor transport and processing. This mutation points to a major contribution of the a subunit carboxyl terminus to insulin binding

    Amyotrophic lateral sclerosis (ALS)-associated VAPB-P56S inclusions represent an ER quality control compartment

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    BACKGROUND: Protein aggregation and the formation of intracellular inclusions are a central feature of many neurodegenerative disorders, but precise knowledge about their pathogenic role is lacking in most instances. Here we have characterized inclusions formed in transgenic mice carrying the P56S mutant form of VAPB that causes various motor neuron syndromes including ALS8.RESULTS: Inclusions in motor neurons of VAPB-P56S transgenic mice are characterized by the presence of smooth ER-like tubular profiles, and are immunoreactive for factors that operate in the ER associated degradation (ERAD) pathway, including p97/VCP, Derlin-1, and the ER membrane chaperone BAP31. The presence of these inclusions does not correlate with signs of axonal and neuronal degeneration, and axotomy leads to their gradual disappearance, indicating that they represent reversible structures. Inhibition of the proteasome and knockdown of the ER membrane chaperone BAP31 increased the size of mutant VAPB inclusions in primary neuron cultures, while knockdown of TEB4, an ERAD ubiquitin-protein ligase, reduced their size. Mutant VAPB did not codistribute with mutant forms of seipin that are associated with an autosomal dominant motor neuron disease, and accumulate in a protective ER derived compartment termed ERPO (ER protective organelle) in neurons.CONCLUSIONS: The data indicate that the VAPB-P56S inclusions represent a novel reversible ER quality control compartment that is formed when the amount of mutant VAPB exceeds the capacity of the ERAD pathway and that isolates misfolded and aggregated VAPB from the rest of the ER. The presence of this quality control compartment reveals an additional level of flexibility of neurons to cope with misfolded protein stress in the ER

    Detection of alpha-toxin and other virulence factors in biofilms of staphylococcus aureus on polystyrene and a human epidermalmodel

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    Background & Aim: The ability of Staphylococcus aureus to successfully colonize (a)biotic surfaces may be explained by biofilm formation and the actions of virulence factors. The aim of the present study was to establish the presence of 52 proteins, including virulence factors such as alpha-toxin, during biofilm formation of five different (methicillin resistant) S. aureus strains on Leiden human epidermal models (LEMs) and polystyrene surfaces (PS) using a competitive Luminex-based assay. Results: All five S. aureus strains formed biofilms on PS, whereas only three out of five strains formed biofilms on LEMs. Out of the 52 tested proteins, six functionally diverse proteins (ClfB, glucosaminidase, IsdA, IsaA, SACOL0688 and nuclease) were detected in biofilms of all strains on both PS and LEMs. At the same time, four toxins (alpha-toxin, gamma-hemolysin B and leukocidins D and E), two immune modulators (formyl peptide receptor-like inhibitory protein and Staphylococcal superantigen-like protein 1), and two other proteins (lipase and LytM) were detectable in biofilms by all five S. aureus strains on LEMs, but not on PS. In contrast, fibronectinbinding protein B (FnbpB) was detectable in biofilms by all S. aureus biofilms on PS, but not on LEMs. These data were largely confirmed by the results from proteomic and transcriptomic analyses and in case of alpha-toxin additionally by GFP-reporter technology. Conclusion: Functionally diverse virulence factors of (methicillin-resistant) S. aureus are present during biofilm formation on LEMs and PS. These results could aid in identifying novel targets for future treatment strategies against biofilm-associated infections
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