scholarly journals The Effect of Speed Humps on Instantaneous Traffic Emissions

2020 ◽  
Vol 10 (5) ◽  
pp. 1592 ◽  
Author(s):  
Julio César Pérez-Sansalvador ◽  
Noureddine Lakouari ◽  
Jesus Garcia-Diaz ◽  
Saúl E. Pomares Hernández
Keyword(s):  
Air Quality ◽  
Traffic Emissions ◽  
Traffic Density ◽  
Traffic Calming ◽  
Specialized Equipment ◽  
Planning Strategies ◽  
The Impact ◽  
Insight Into ◽  
Speed Humps

Bad air quality due to free pollutants such as particulate matter (PM), carbon dioxide (CO 2 ), nitrogen oxides (NO x ) and volatile organic components (VOC) increases the risk of long- term health diseases. The impact of traffic-calming measures on air quality has been studied using specialized equipment at control sites or mounted on cars to monitor pollutants levels. However, this approach suffers from a large number of variables on the experiments such as vehicles types, number of monitored vehicles, driver’s behavior, traffic density, time of the day, elapsed monitoring time, road conditions and weather. In this work, we use a cellular automata and an instantaneous traffic emissions model to capture the effect of speed humps on traffic flow and on the generation of CO 2 , NO x , VOC and PM pollutants. This approach allows us to study and characterize the effect of many speed humps on a single lane. We found that speed humps significantly promote the generation of pollutants when the number of vehicles on a lane is low. Our results may provide insight into urban planning strategies to reduce the generation of traffic emissions and lower the risk of long-term health diseases.

Methods to Reduce Traffic Speed in High-Pedestrian Rural Areas

2003 ◽  
Vol 1828 (1) ◽  
pp. 31-37 ◽  
Author(s):  
Ali Kamyab ◽  
Steve Andrle ◽  
Dennis Kroeger ◽  
David S. Heyer
Keyword(s):  
Rural Areas ◽  
Speed Limit ◽  
Single Word ◽  
Short Term ◽  
Speed Reduction ◽  
Traffic Calming ◽  
Reduction Strategies ◽  
Long Term Impact ◽  
The Impact

Many Minnesota counties are faced with the problem of high vehicle speeds through towns or resort areas that have significant pedestrian traffic. The impact of speed reduction strategies in high-pedestrian areas in rural counties of Minnesota was investigated. Speed data were collected at two selected study sites under their existing conditions ("no-treatment" or "before" condition) and after the proposed speed reduction strategies were installed. Second "after" data conditions were collected to study the short-term and long-term impact of the implemented strategies. The traffic-calming techniques employed at the Twin Lakes site consisted of removable pedestrian islands and pedestrian crossing signs. A dynamic variable message sign that sent a single-word message ("Slow") to motorists traveling over the speed limit was installed at the Bemidji site. The research study shows that the traffic-calming strategy deployed in Twin Lakes was effective in significantly reducing the mean speed and improving speed limit compliance in both the short term and long term. Despite proven effectiveness, the deployed speed reduction treatment in Bemidji Lake failed to lower the speed at the study site. The single-word message on the sign and the location of the sign, as well as a lack of initial enforcement, were the primary reasons for such failure.

First year of real-time VOC measurements at the SIRTA facility (Paris region, France): diurnal and seasonal variabilities, impact of lockdowns on air quality

2021 ◽  
Author(s):  
Leïla Simon ◽  
Valérie Gros ◽  
Jean-Eudes Petit ◽  
François Truong ◽  
Roland Sarda-Esteve ◽  
...  
Keyword(s):  
Air Quality ◽  
Atmospheric Chemistry ◽  
Seasonal Variability ◽  
Anthropogenic Sources ◽  
First Year ◽  
Good Representation ◽  
Atmospheric Measurements ◽  
Paris Region ◽  
The Impact

<p>Volatile Organic Compounds (VOCs) have direct influences on air quality and climate. They also play a key role in atmospheric chemistry, as they are precursors of secondary pollutants, such as ozone (O<sub>3</sub>) and secondary organic aerosols (SOA).</p><p>Long-term datasets of in-situ atmospheric measurements are crucial to characterize the variability of atmospheric chemical composition. Online and continuous measurements of O<sub>3</sub>, NO<sub>x</sub> and aerosols have been achieved at the SIRTA-ACTRIS facility (Paris region, France), since 2012. Regarding VOCs, they have been measured there for several years thanks to bi-weekly samplings followed by offline Gas Chromatography analysis. However, this method doesn’t provide a good representation of the temporal variability of VOC concentrations. To tackle this issue, online VOC measurements using a Proton-Transfer-Reaction Quadrupole Mass-Spectrometer (PTR-Q-MS) have been started in January 2020.</p><p>The dataset acquired during the first year of online VOC measurements is analyzed, which gives insights on VOC seasonal variability. The additional long-term datasets obtained from co-located measurements (O<sub>3</sub>, NO<sub>x</sub>, aerosol physical and chemical properties, meteorological parameters) are also used for the sake of this study.</p><p>Due to Covid-19 pandemic, the year 2020 notably comprised a total lockdown in France in Spring, and a lighter one in Autumn. Therefore, a focus can be made on the impact of these lockdowns on the VOC variability and sources. To this end, the diurnal cycles of VOCs considered markers for anthropogenic sources are carefully investigated. Results notably indicate that markers for traffic and wood burning sources behave quite differently during the Spring lockdown in comparison to the other periods. A source apportionment analysis using positive matrix factorization allows to further document the seasonal variability of VOC sources and the impacts on air quality associated with the lockdown measures.</p>

scholarly journals Exploring the effects of long-term anti-social behaviour victimisation

2020 ◽  
pp. 026975802096197
Author(s):  
Vicky Heap
Keyword(s):  
Qualitative Research ◽  
Social Behaviour ◽  
Empirical Work ◽  
Criminal Behaviour ◽  
Structured Interviews ◽  
Different Types ◽  
The Impact ◽  
Mental And Physical Health ◽  
Insight Into

Despite victimological interest in the impacts of different types of criminal victimisation, there is little empirical work that examines the effects of sub-criminal behaviour on victims. This article begins to redress the balance by reporting the findings from a qualitative research project in England that investigated the effects of long-term anti-social behaviour victimisation. Semi-structured interviews explored victims’ accounts of the long-term anti-social behaviour they experienced and the resultant effects it had on their lives. The research uncovered that victims experience a range of mental and physical health effects as well as behavioural changes and has provided the first in-depth insight into the impact of this type of victimisation. The findings suggest the cumulative harms associated with anti-social behaviour need to be better acknowledged, understood and addressed, with greater support made available to victims.

scholarly journals Evaluating the impact of long-term exposure to fine particulate matter on mortality among the elderly

2020 ◽  
Vol 6 (29) ◽  
pp. eaba5692 ◽  
Author(s):  
X. Wu ◽  
D. Braun ◽  
J. Schwartz ◽  
M. A. Kioumourtzoglou ◽  
F. Dominici
Keyword(s):  
Air Quality ◽  
Fine Particulate Matter ◽  
Quality Standards ◽  
The Elderly ◽  
Quality Standard ◽  
Causal Link ◽  
Fine Particulate ◽  
The Impact ◽  
Current Standards

Many studies link long-term fine particle (PM2.5) exposure to mortality, even at levels below current U.S. air quality standards (12 micrograms per cubic meter). These findings have been disputed with claims that the use of traditional statistical approaches does not guarantee causality. Leveraging 16 years of data—68.5 million Medicare enrollees—we provide strong evidence of the causal link between long-term PM2.5 exposure and mortality under a set of causal inference assumptions. Using five distinct approaches, we found that a decrease in PM2.5 (by 10 micrograms per cubic meter) leads to a statistically significant 6 to 7% decrease in mortality risk. Based on these models, lowering the air quality standard to 10 micrograms per cubic meter would save 143,257 lives (95% confidence interval, 115,581 to 170,645) in one decade. Our study provides the most comprehensive evidence to date of the link between long-term PM2.5 exposure and mortality, even at levels below current standards.

scholarly journals Temperature response measurements from eucalypts give insight into the impact of Australian isoprene emissions on air quality in 2050

2020 ◽  
Vol 20 (10) ◽  
pp. 6193-6206
Author(s):  
Kathryn M. Emmerson ◽  
Malcolm Possell ◽  
Michael J. Aspinwall ◽  
Sebastian Pfautsch ◽  
Mark G. Tjoelker
Keyword(s):  
Air Quality ◽  
Transport Model ◽  
Temperature Response ◽  
Emission Factors ◽  
Eucalyptus Species ◽  
Chemical Transport Model ◽  
Mixing Ratios ◽  
The Impact ◽  
Temperature Responses ◽  
Insight Into

Abstract. Predicting future air quality in Australian cities dominated by eucalypt emissions requires an understanding of their emission potentials in a warmer climate. Here we measure the temperature response in isoprene emissions from saplings of four different Eucalyptus species grown under current and future average summertime temperature conditions. The future conditions represent a 2050 climate under Representative Concentration Pathway 8.5, with average daytime temperatures of 294.5 K. Ramping the temperature from 293 to 328 K resulted in these eucalypts emitting isoprene at temperatures 4–9 K higher than the default maximum emission temperature in the Model of Emissions of Gases and Aerosols from Nature (MEGAN). New basal emission rate measurements were obtained at the standard conditions of 303 K leaf temperature and 1000 µmol m−2 s−1 photosynthetically active radiation and converted into landscape emission factors. We applied the eucalypt temperature responses and emission factors to Australian trees within MEGAN and ran the CSIRO Chemical Transport Model for three summertime campaigns in Australia. Compared to the default model, the new temperature responses resulted in less isoprene emission in the morning and more during hot afternoons, improving the statistical fit of modelled to observed ambient isoprene. Compared to current conditions, an additional 2 ppb of isoprene is predicted in 2050, causing hourly increases up to 21 ppb of ozone and 24-hourly increases of 0.4 µg m−3 of aerosol in Sydney. A 550 ppm CO2 atmosphere in 2050 mitigates these peak Sydney ozone mixing ratios by 4 ppb. Nevertheless, these forecasted increases in ozone are up to one-fifth of the hourly Australian air quality limit, suggesting that anthropogenic NOx should be further reduced to maintain healthy air quality in future.

The struggle for good care: moral challenges during the COVID-19 lockdown of Dutch elderly care facilities

2022 ◽  
Author(s):  
Wendy van der Geugten ◽  
Gaby Jacobs ◽  
Anne Goossensen
Keyword(s):  
Moral Distress ◽  
Elderly Care ◽  
Term Care ◽  
Care Facilities ◽  
The Impact ◽  
Personal Ethics ◽  
Depth Interviews ◽  
Insight Into

The COVID-19 lockdown of Dutch long-term care facilities between March and May 2020 affected the quality of lives of residents and opposed professional and personal ethics of care. This article, based on 25 in-depth interviews with healthcare chaplains, gives insight into what moral challenges appeared for care professionals. Moral challenges were related to: ‘family ruptures’, ‘residents’ loneliness and despair’, ‘cold-hearted deaths’ and ‘response and responsibilities’. The findings illuminate the complexity of providing care during the lockdown and show variation in the impact of these ethical experiences, in which both moral distress and moral resilience occurred.

scholarly journals Contribution of emissions to concentrations: the TAGGING 1.0 submodel based on the Modular Earth Submodel System (MESSy 2.52)

2017 ◽  
Vol 10 (7) ◽  
pp. 2615-2633 ◽  
Author(s):  
Volker Grewe ◽  
Eleni Tsati ◽  
Mariano Mertens ◽  
Christine Frömming ◽  
Patrick Jöckel
Keyword(s):  
Air Quality ◽  
Tropospheric Ozone ◽  
Radiative Forcing ◽  
Road Traffic ◽  
Computing Time ◽  
Reaction Rates ◽  
Traffic Emissions ◽  
Time Step ◽  
Road Traffic Emissions ◽  
The Impact

Abstract. Questions such as what is the contribution of road traffic emissions to climate change? or what is the impact of shipping emissions on local air quality? require a quantification of the contribution of specific emissions sectors to the concentration of radiatively active species and air-quality-related species, respectively. Here, we present a diagnostics package, implemented in the Modular Earth Submodel System (MESSy), which keeps track of the contribution of source categories (mainly emission sectors) to various concentrations. The diagnostics package is implemented as a submodel (TAGGING) of EMAC (European Centre for Medium-Range Weather Forecasts – Hamburg (ECHAM)/MESSy Atmospheric Chemistry). It determines the contributions of 10 different source categories to the concentration of ozone, nitrogen oxides, peroxyacytyl nitrate, carbon monoxide, non-methane hydrocarbons, hydroxyl, and hydroperoxyl radicals ( =  tagged tracers). The source categories are mainly emission sectors and some other sources for completeness. As emission sectors, road traffic, shipping, air traffic, anthropogenic non-traffic, biogenic, biomass burning, and lightning are considered. The submodel obtains information on the chemical reaction rates, online emissions, such as lightning, and wash-out rates. It then solves differential equations for the contribution of a source category to each of the seven tracers. This diagnostics package does not feed back to any other part of the model. For the first time, it takes into account chemically competing effects: for example, the competition between NOx, CO, and non-methane hydrocarbons (NMHCs) in the production and destruction of ozone. We show that the results are in-line with results from other tagging schemes and provide plausibility checks for concentrations of trace gases, such as OH and HO2, which have not previously been tagged. The budgets of the tagged tracers, i.e. the contribution from individual source categories (mainly emission sectors) to, e.g., ozone, are only marginally sensitive to changes in model resolution, though the level of detail increases. A reduction in road traffic emissions by 5 % shows that road traffic global tropospheric ozone is reduced by 4 % only, because the net ozone productivity increases. This 4 % reduction in road traffic tropospheric ozone corresponds to a reduction in total tropospheric ozone by  ≈  0.3 %, which is compensated by an increase in tropospheric ozone from other sources by 0.1 %, resulting in a reduction in total tropospheric ozone of  ≈  0.2 %. This compensating effect compares well with previous findings. The computational costs of the TAGGING submodel are low with respect to computing time, but a large number of additional tracers are required. The advantage of the tagging scheme is that in one simulation and at every time step and grid point, information is available on the contribution of different emission sectors to the ozone budget, which then can be further used in upcoming studies to calculate the respective radiative forcing simultaneously.

scholarly journals Obesity alters the long-term fitness of the hematopoietic stem cell compartment through modulation of Gfi1 expression

2017 ◽  
Vol 215 (2) ◽  
pp. 627-644 ◽  
Author(s):  
Jung-Mi Lee ◽  
Vinothini Govindarajah ◽  
Bryan Goddard ◽  
Ashwini Hinge ◽  
David E. Muench ◽  
...  
Keyword(s):  
Stem Cell ◽  
Hematopoietic Stem Cell ◽  
Cell Compartment ◽  
Hematopoietic Stem ◽  
Stem Cell Compartment ◽  
Normal Environment ◽  
Key Driver ◽  
The Impact ◽  
Insight Into

Obesity is a chronic organismal stress that disrupts multiple systemic and tissue-specific functions. In this study, we describe the impact of obesity on the activity of the hematopoietic stem cell (HSC) compartment. We show that obesity alters the composition of the HSC compartment and its activity in response to hematopoietic stress. The impact of obesity on HSC function is progressively acquired but persists after weight loss or transplantation into a normal environment. Mechanistically, we establish that the oxidative stress induced by obesity dysregulates the expression of the transcription factor Gfi1 and that increased Gfi1 expression is required for the abnormal HSC function induced by obesity. These results demonstrate that obesity produces durable changes in HSC function and phenotype and that elevation of Gfi1 expression in response to the oxidative environment is a key driver of the altered HSC properties observed in obesity. Altogether, these data provide phenotypic and mechanistic insight into durable hematopoietic dysregulations resulting from obesity.

scholarly journals The Discerning Ear: Cardiac Auscultation in the Era of Artificial Intelligence and Telemedicine

2021 ◽  
Author(s):  
Vivek Jani ◽  
David A Danford ◽  
W Reid Thompson ◽  
Andreas Schuster ◽  
Cedric Manlhiot ◽  
...  
Keyword(s):  
Artificial Intelligence ◽  
Computer Assisted ◽  
Cardiac Auscultation ◽  
Cardiac Murmur ◽  
New Era ◽  
History Of ◽  
The Impact ◽  
Paradigm Shifting ◽  
Insight Into

Abstract Heart murmur, a thoracic auscultatory finding of cardiovascular origin, is extremely common in childhood and can appear at any age from premature newborn to late adolescence. The objective of this review is to provide a modern examination and update of cardiac murmur auscultation in this new era of artificial intelligence and telemedicine. First, we provide a comprehensive review of the causes and differential diagnosis, clinical features, evaluation, and long-term management of pediatric heart murmurs. Next, we provide a brief history of computer-assisted auscultation and murmur analysis, along with insight into the engineering design of the digital stethoscope. We conclude with a discussion of the paradigm shifting impact of deep learning on murmur analysis, artificial intelligence assisted auscultation, and the implications of these technologies on telemedicine in pediatric cardiology. It is our hope that this article provides an updated perspective on the impact of artificial intelligence on cardiac auscultation for the modern pediatric cardiologist.

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