60419 research outputs found
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In-car particulate matter exposure across ten global cities
No full textCars are a commuting lifeline worldwide, despite contributing significantly to air pollution. This is the first global assessment on air pollution exposure in cars across ten cities: Dhaka (Bangladesh); Chennai (India); Guangzhou (China); Medellín (Colombia); São Paulo (Brazil); Cairo (Egypt); Sulaymaniyah (Iraq); Addis Ababa (Ethiopia); Blantyre (Malawi); and Dar-es-Salaam (Tanzania). Portable laser particle counters were used to develop a proxy of car-user exposure profiles and analyse the factors affecting particulate matter ≤2.5 μm (PM2.5; fine fraction) and ≤10 μm (PM2.5–10; coarse fraction). Measurements were carried out during morning, off- and evening-peak hours under windows-open and windows-closed (fan-on and recirculation) conditions on predefined routes. For all cities, PM2.5 and PM10 concentrations were highest during windows-open, followed by fan-on and recirculation. Compared with recirculation, PM2.5 and PM10 were higher by up to 589% (Blantyre) and 1020% (São Paulo), during windows-open and higher by up to 385% (São Paulo) and 390% (São Paulo) during fan-on, respectively. Coarse particles dominated the PM fraction during windows-open while fine particles dominated during fan-on and recirculation, indicating filter effectiveness in removing coarse particles and a need for filters that limit the ingress of fine particles. Spatial variation analysis during windows-open showed that pollution hotspots make up to a third of the total route-length. PM2.5 exposure for windows-open during off-peak hours was 91% and 40% less than morning and evening peak hours, respectively. Across cities, determinants of relatively high personal exposure doses included lower car speeds, temporally longer journeys, and higher in-car concentrations. It was also concluded that car-users in the least affluent cities experienced disproportionately higher in-car PM2.5 exposures. Cities were classified into three groups according to low, intermediate and high levels of PM exposure to car commuters, allowing to draw similarities and highlight best practices
Devolving skills: The case of the Apprenticeship Grant for Employers
No full textOne rationale for devolution is that local decision makers may be well placed to adapt national policies to the local context. We test whether such adaptation helps meet programme objectives in the case of the Apprenticeship Grant for Employers. Originally a national programme, aimed at incentivising employers to take on apprentices, reforms a few years into operation gave some Local Authorities negotiated flexibilities in how the scheme operated. We consider the impact of the national scheme and then use a difference-in-differences approach to test whether flexibility led to an increase in the number of apprenticeship starts in devolved areas relative to control groups. We find that flexibility had zero effect. There is suggestive evidence that this is because flexibilities were negotiated on the wrong margins
Audio for Audio is Better? An Investigation on Transfer Learning Models for Heart Sound Classification
No full textCardiovascular disease is one of the leading
factors for death cause of human beings. In
the past decade, heart sound classification has been
increasingly studied for its feasibility to develop a
non-invasive approach to monitor a subject’s health
status. Particularly, relevant studies have benefited
from the fast development of wearable devices and
machine learning techniques. Nevertheless, finding
and designing efficient acoustic properties from heart
sounds is an expensive and time-consuming task. It
is known that transfer learning methods can help
extract higher representations automatically from the
heart sounds without any human domain knowledge.
However, most existing studies are based on models
pre-trained on images, which may not fully represent
the characteristics inherited from audio. To this
end, we propose a novel transfer learning model pretrained
on large scale audio data for a heart sound
classification task. In this study, the PhysioNet CinC
Challenge Dataset is used for evaluation. Experimental
results demonstrate that, our proposed pre-trained
audio models can outperform other popular models
pre-trained by images by achieving the highest unweighted
average recall at 89.7 %
Filipino migrant workers’ leisure and subjective quality of life in Macao
No full textUtilizing 14 semi-structured interviews in a non-western context, this exploratory study examines how Filipino migrant workers’ leisure satisfaction and QoL are intertwined in Macao, China. The study reveals that Filipino migrant workers regard “family and friends”, and a sense of community as central to their QoL. Regarding leisure, the Filipino migrant workers experienced a lack of time-off and long working hours (structural leisure constraints) whilst living without their families in the Philippines (interpersonal leisure constraints). In addition, the Filipino migrant workers noted that few leisure options were available to them, and given commercial options dominate in Macao, the perceived cost of leisure participation clashes with the Filipino migrant workers responsibility to send remittances home. It is recommended that authorities and employers explore the importance of subjective QoL indicators such as sense of community that emerge from marginalized social groups, such as migrant workers, into their measurement systems and policy deliberations, to create a livable and sustainable community for all. Our study enriches the extant research by broadening the research location to focus on “voices” from low income migrants in a non-western context
Concept Design of Jacket foundations for Offshore Wind Turbines in 10 steps
No full textSimplified design procedures for offshore wind turbine (OWT) support structures are necessary in the concept and tender design stages for assessing the financial viability. Building upon the previous research on simplified monopile design, this paper presents a similar method to design jacket supported OWTs founded on piles or suction caissons. The method is based on the minimum and necessary data, namely the site characteristics (wind speed at reference height, wind turbulence intensity, water depth, wave height and wave period), turbine characteristics (rated power, rated wind speed, rotor diameter, cut-in and cut-out speed, mass of the rotor-nacelle-assembly) and ground profile (soil stiffness variation with depth and soil strength). A flowchart of the design process is also presented for visualisation of the rather complex multi-disciplinary analysis. Insights are given for 3 and 4 legged jackets. The calculation procedures that are required can be easily carried out either through a series of spreadsheets or simple hand calculations. An example problem emulating the design of jacket on piles is taken from literature to demonstrate the proposed calculation procedure. The data used for the calculations are obtained from publicly available sources and the example shows that the simplified method arrives at a similar foundation to the one reported
Viral cGAMP nuclease reveals the essential role of DNA sensing in protection against acute lethal virus infection
No full textCells contain numerous immune sensors to detect virus infection. The cyclic GMP-AMP (cGAMP) synthase (cGAS) recognizes cytosolic DNA and activates innate immune responses via stimulator 2of interferon genes (STING), but the impact of DNA sensing pathways on host protective responses has not been fully defined. We demonstrate that cGAS/STING activation is required to resist lethal poxvirus infection. We identified viral Schlafen (vSlfn) as the main STING inhibitor and ectromelia virus was severely attenuated in the absence of vSlfn. Both vSlfn-mediated virulence and STING inhibitory activity mapped to the recently discovered poxin cGAMP nuclease domain. Animals were protected from subcutaneous, respiratory and intravenous infection in the absence of vSlfn, and interferon was the main anti-viral protective mechanism controlled by the DNA sensing pathway. Our findings support that manipulation of DNA sensing is an efficient therapeutic strategy in diseases triggered by viral infection or tissue damage-mediated release of self-DNA
Structure of the Inhibited State of the Sec Translocon
No full textProtein secretion in eukaryotes and prokaryotes involves a universally conserved protein translocation chan-nel formed by the Sec61 complex. Unrelated small-molecule natural products and synthetic compoundsinhibit Sec61 with differential effects for different substrates or for Sec61 from different organisms, makingthis a promising target for therapeutic intervention. To understand the mode of inhibition and provide insightinto the molecular mechanism of this dynamic translocon, we determined the structure of mammalian Sec61inhibited by theMycobacterium ulceransexotoxin mycolactone via electron cryo-microscopy. Unexpect-edly, the conformation of inhibited Sec61 is optimal for substrate engagement, with mycolactone wedgingopen the cytosolic side of the lateral gate. The inability of mycolactone-inhibited Sec61 to effectively trans-port substrate proteins implies that signal peptides and transmembrane domains pass through the site occu-pied by mycolactone. This provides a foundation for understanding the molecular mechanism of Sec61 inhib-itors and reveals novel features of translocon function and dynamics
Blue-Enriched White Light Improves Performance but Not Subjective Alertness and Circadian Adaptation During Three Consecutive Simulated Night Shifts
No full textUse of blue-enriched light has received increasing interest regarding its activating
and performance sustaining effects. However, studies assessing effects of such light
during night work are few, and novel strategies for lighting using light emitting diode
(LED) technology need to be researched. In a counterbalanced crossover design, we
investigated the effects of a standard polychromatic blue-enriched white light (7000 K;
�200 lx) compared to a warm white light (2500 K), of similar photon density (�1.6
� 1014 photons/cm2/s), during three consecutive simulated night shifts. A total of
30 healthy participants [10 males, mean age 23.3 (SD = 2.9) years] were included in
the study. Dependent variables comprised subjective alertness using the Karolinska
Sleepiness Scale, a psychomotor vigilance task (PVT) and a digit symbol substitution
test (DSST), all administered at five time points throughout each night shift. We also
assessed dim-light melatonin onset (DLMO) before and after the night shifts, as well
as participants’ opinion of the light conditions. Subjective alertness and performance
on the PVT and DSST deteriorated during the night shifts, but 7000 K light was more
beneficial for performance, mainly in terms of fewer errors on the PVT, at the end of
the first- and second- night shift, compared to 2500 K light. Blue-enriched light only
had a minor impact on PVT response times (RTs), as only the fastest 10% of the RTs
were significantly improved in 7000 K compared to 2500 K light. In both 7000 and
2500 K light, the DLMO was delayed in those participants with valid assessment of
this parameter [n = 20 (69.0%) in 7000 K light, n = 22 (78.6%) in 2500 K light], with
a mean of 2:34 (SE = 0:14) and 2:12 (SE = 0:14) hours, respectively, which was not
significantly different between the light conditions. Both light conditions were positively
rated, although participants found 7000 K to be more suitable for work yet evaluated
2500 K light as more pleasant. The data indicate minor, but beneficial, effects of 7000 K light compared to 2500 K light on performance during night work. Circadian adaptation
did not differ significantly between light conditions, though caution should be taken when
interpreting these findings due to missing data. Field studies are needed to investigate
similar light interventions in real-life settings, to develop recommendations regarding
illumination for night workers
Tourism and Trust: Theoretical reflections
No full textTourism researchers have increasingly, but selectively and uncritically, engaged with the notion of trust. This study therefore aims to provide a stronger theoretical foundation for understanding tourism related trust, starting from consideration of uncertainty and the nature of tacit knowledge. The relationship between displacement and uncertainty is at the core of the distinctiveness of trust in tourism, highlighting the importance of institutions, but also recognizing the diversity of tourism contexts. Three disciplinary perspectives on trust are considered: economics, psychology and sociology. After outlining their general characteristics in relation to McKnight and Chervany’s (2001) typology of trust, we review their application in tourism, and conclude by identifying a future research agenda to address the distinctive characteristics of trust in tourism
Molière maximum likelihood proton path estimation approximated by cubic Bézier curve for scatter corrected proton CT reconstruction
No full textA maximum likelihood approach to the problem of calculating the proton paths inside the scanned object in proton computed tomography is presented. Molière theory is used for first time to derive a physical model that describes proton multiple Coulomb scattering, avoiding the need for the Gaussian approximation currently used. To enable this, the proposed method approximates proton paths with cubic Bézier curves and subsequently maximizes the path likelihood through parametric optimization, based on the Molière model. Results from the Highland formula-based Gaussian approximation are also presented for comparison. The simplex method is utilized for optimisation. The scattering properties of the material(s) of the scanned object are taken into account by appropriately calculating the scattering parameters from the stopping power map that is calculated/updated at every iteration of the algebraic reconstruction process. Proton track length constraint imposed by the proton energy loss is also accounted for. The method is also applied in the case that no exit angle data are measured. Geant4 Monte Carlo simulations were performed for model validation. Our results show that use of Molière probability density function for modelling the multiple Coulomb scattering presents a modest 2% accuracy improvement over the Gaussian approximation and most-likely-path method. Simulations of voxelized phantom showed no essential benefit from the inclusion of the material information into the optimization, while path optimization with energy constraint slightly increased path resolution in a bone/water interface phantom. Method error was found to depend on energy, proton track-length within the medium, and proportion of data filtering
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