1,156 research outputs found

    Exploring psychoacoustic indicators of tyre/road noise in urban environments

    Get PDF
    Road traffic noise is the most common source of community noise in urban areas, causing adverse impacts on the health and well-being of the exposed population. Therefore, mastering road traffic noise perception is key to tackling noise pollution. Vehicle noise is mainly produced by the tyre/pavement interaction, especially for light vehicles, which compose most of the vehicle fleet in urban environments. In this paper, tyre/road noise recordings were collected with the Close-ProXimity (CPX) method using the P1 reference tyre for light vehicles and employing low speeds, up to 50 km/h. Road surface types were chosen to represent urban environments, such as cobblestones, aged and recently-laid dense asphalt concrete and low-noise pavements. Noise levels and psychoacoustic parameters were retrieved to describe the complex time- and frequency-dependent signal features of tyre/road noise. The sensitivity of psychoacoustic indicators to differences in road surface type, age, and testing speeds was explored. Ultimately, a tyre/road noise catalogue that lists noise levels and noise features more closely related to human perception can aid urban planning and environmental noise control

    HID-1 controls formation of large dense core vesicles by influencing cargo sorting and trans-Golgi network acidification

    Get PDF
    Large dense core vesicles (LDCVs) mediate the regulated release of neuropeptides and peptide hormones. They form at the trans-Golgi network (TGN), where their soluble content aggregates to form a dense core, but the mechanisms controlling biogenesis are still not completely understood. Recent studies have implicated the peripheral membrane protein HID-1 in neuropeptide sorting and insulin secretion. Using CRISPR/Cas9, we generated HID-1 KO rat neuroendocrine cells, and we show that the absence of HID-1 results in specific defects in peptide hormone and monoamine storage and regulated secretion. Loss of HID-1 causes a reduction in the number of LDCVs and affects their morphology and biochemical properties, due to impaired cargo sorting and dense core formation. HID-1 KO cells also exhibit defects in TGN acidification together with mislocalization of the Golgi-enriched vacuolar H+-ATPase subunit isoform a2. We propose that HID-1 influences early steps in LDCV formation by controlling dense core formation at the TGN.</jats:p

    PENCIL: Towards a Platform-Neutral Compute Intermediate Language for DSLs

    Full text link
    We motivate the design and implementation of a platform-neutral compute intermediate language (PENCIL) for productive and performance-portable accelerator programming

    On the epidemiology of influenza: reply to Radonovich et al

    Get PDF
    On the epidemiology of influenza: reply to Radonovich LJ, Martinello RA, Hodgson M, Milton DK, Nardell EA. Influenza and ultraviolet germicidal irradiation. Virol J. 2008, 5:14

    On the epidemiology of influenza

    Get PDF
    The epidemiology of influenza swarms with incongruities, incongruities exhaustively detailed by the late British epidemiologist, Edgar Hope-Simpson. He was the first to propose a parsimonious theory explaining why influenza is, as Gregg said, "seemingly unmindful of traditional infectious disease behavioral patterns." Recent discoveries indicate vitamin D upregulates the endogenous antibiotics of innate immunity and suggest that the incongruities explored by Hope-Simpson may be secondary to the epidemiology of vitamin D deficiency. We identify – and attempt to explain – nine influenza conundrums: (1) Why is influenza both seasonal and ubiquitous and where is the virus between epidemics? (2) Why are the epidemics so explosive? (3) Why do they end so abruptly? (4) What explains the frequent coincidental timing of epidemics in countries of similar latitude? (5) Why is the serial interval obscure? (6) Why is the secondary attack rate so low? (7) Why did epidemics in previous ages spread so rapidly, despite the lack of modern transport? (8) Why does experimental inoculation of seronegative humans fail to cause illness in all the volunteers? (9) Why has influenza mortality of the aged not declined as their vaccination rates increased? We review recent discoveries about vitamin D's effects on innate immunity, human studies attempting sick-to-well transmission, naturalistic reports of human transmission, studies of serial interval, secondary attack rates, and relevant animal studies. We hypothesize that two factors explain the nine conundrums: vitamin D's seasonal and population effects on innate immunity, and the presence of a subpopulation of "good infectors." If true, our revision of Edgar Hope-Simpson's theory has profound implications for the prevention of influenza

    Predicting vehicle category using psychoacoustic indicators from road traffic pass-by noise

    Get PDF
    A set of road traffic pass-by noises containing more than 2000 vehicles was recorded following the Statistical Pass-By (SPB) methodology. Besides the acoustic descriptors, psychoacoustic indicators (loudness, sharpness, roughness, fluctuation strength) were retrieved for each pass-by of three vehicle categories defined in the standard (passenger cars, dual-axles and multi-axles heavy vehicles). A fourth vehicle category, comprised of delivery vans, was also investigated. All psychoacoustic indicators significantly differed among vehicle categories, meaning that not only intensity descriptors but also temporal and spectral features of pass-by noise distinguish those classes. With enough instances and a balanced dataset across groups, a machine-learning classification algorithm was trained with 70% of the dataset to predict vehicle categories using the psychoacoustic indicators. Classification accuracy on the test set reached 72%. Accuracy losses were primarily caused by 25% of the actual passenger cars being misclassified as vans and vice-versa. These results show the potential of using noise features other than uniquely the maximum noise level to classify vehicles in terms of noise perception. In this way, limiting classifications based on visual aspects of vehicle categories may be overcome, increasing the practicality and accuracy of measurements such as the SPB, as vehicle fleets worldwide are more consistently represented.The authors thank the Research Foundation – Flanders (FWO) for the travel grant allocated to Ablenya Barros (file ID K149723N)

    The mechanisms used by enteropathogenic Escherichia coli to control filopodia dynamics

    Get PDF
    Enteropathogenic Escherichia coli (EPEC) subverts actin dynamics in eukaryotic cells by injecting effector proteins via a type III secretion system. First, WxxxE effector Map triggers transient formation of filopodia. Then, following recovery from the filopodial signals, EPEC triggers robust actin polymerization via a signalling complex comprising Tir and the adaptor proteins Nck. In this paper we show that Map triggers filopodia formation by activating Cdc42; expression of dominant-negative Cdc42 or knock-down of Cdc42 by siRNA impaired filopodia formation. In addition, Map binds PDZ1 of NHERF1. We show that Map–NHERF1 interaction is needed for filopodia stabilization in a process involving ezrin and the RhoA/ROCK cascade; expression of dominant-negative ezrin and RhoA or siRNA knock-down of RhoA lead to rapid elimination of filopodia. Moreover, we show that formation of the Tir-Nck signalling complex leads to filopodia withdrawal. Recovery from the filopodial signals requires phosphorylation of a Tir tyrosine (Y474) residue and actin polymerization pathway as both infection of cells with EPEC expressing TirY474S or infection of Nck knockout cells with wild-type EPEC resulted in persistence of filopodia. These results show that EPEC effectors modulate actin dynamics by temporal subverting the Rho GTPases and other actin polymerization pathways for the benefit of the adherent pathogen
    corecore