Perception of urban park soundscape

A number of studies have been initiated to explore how to improve the soundscape quality in urban parks. However, good soundscape quality in parks cannot be provided without a thorough understanding of the complex relationships among sound, environment, and individuals. As acoustic comfort is considered to be an important outcome of soundscape quality, this study investigates the relative impacts of the factors influencing acoustic comfort evaluation by formulating a multivariate ordered logit model. This study also explores the inter-relationships among acoustic comfort evaluation, acceptability of the environment, and preference to stay in a park using a path model. A total of 595 valid responses were obtained from interview surveys administered in four parks in Hong Kong while objective sound measurements were carried out at the survey spots concurrently. The findings unveil that acoustic comfort evaluation, besides visual comfort evaluation of landscape, also plays an important role on users’ acceptability of the urban park environment. Compared with all the studied acoustic related factors, acoustic comfort evaluation serves as a better proxy for park users’ preference to stay in urban parks. Hearing the breeze will significantly increase the likelihood of individuals in giving high acoustic comfort evaluation. Conversely, hearing the sounds from heavy vehicles or sounds from bikes will significantly reduce the likelihood in giving a high acoustic evaluation.Department of Building Services EngineeringDepartment of Mechanical Engineerin

On the study of the effects of sea views, greenery views and personal characteristics on noise annoyance perception at homes

Noise annoyance has caused significant adverse impacts on human beings and numerous efforts have been spent on mitigating annoyance problems. Natural greenery has been shown to be able to moderate annoyance problems at home but this conclusion was drawn without properly controlling the potential confounding factors. Furthermore, few have explored the moderation effect of a sea view. Accordingly, this study formulated a multivariate model to examine the impacts of natural views as well as personal characteristics on annoyance perception. A housing estate was selected in Hong Kong as the survey site for which some of the residents were exposed to greenery views, sea views, or both from their homes. Eight hundred and sixty-one responses were collected via questionnaire surveys and analyzed using an ordered logit model. The results suggest that both a greenery view and a sea view can moderate annoyance responses. Several individual’s personal characteristics are found to affect individuals’ annoyance perception. The duration of time spent daily at home is shown to have an influence on the moderation impact exerted by a greenery view, while the age of an individual is shown to have an influence on noise moderation effect exerted by a sea view.Department of Building Services Engineerin

Percepção sonora e conforto acústico em espaços urbanos do município de Belo Horizonte, MG

Resumo O presente artigo tem como objetivo apresentar e analisar as respostas dos usuários de espaços urbanos abertos com relação à percepção do volume sonoro e à avaliação de conforto acústico, com base em dados coletados em campo durante o ano de 2013, em duas praças do município de Belo Horizonte, MG. Durante os levantamentos, dados acústicos foram medidos simultaneamente à aplicação de questionários, utilizados para coleta de variáveis subjetivas e individuais. O LAeq,T foi o índice utilizado para caracterização dos ambientes sonoros. Os resultados demonstram que, sob as mesmas condições acústicas, tanto no que diz respeito à percepção do volume sonoro quanto à avaliação de conforto acústico, os indivíduos tendem a ser mais tolerantes na praça que possui a melhor ambiência e as melhores condições de conforto térmico. As faixas de percepção do volume sonoro definidas neste estudo foram: Baixo, LAeq < 35 dB(A); Normal, 36 < LAeq < 67 dB(A); Alto, LAeq > 68 dB(A). Com relação à avaliação do conforto acústico, as faixas definidas foram: Confortável, LAeq < 67 dB(A); e Desconfortável, LAeq > 68 dB(A). Espera-se que esses resultados contribuam para um maior entendimento das questões relativas ao conforto acústico urbano

Clofibric acid or diethylmaleate supplemented diet decrease blood pressure in DOCA-salt treated male Sprague Dawley rats--relation with liver antioxidant status.

International audienceThe effects of 8-week diethylmaleate (DEM) and clofibric acid (CFA) supplemented diet on blood pressure, body and liver weights, liver antioxidant status and nitric oxide synthase (NOS) activity were investigated in 8-week DOCA-salt treated and untreated Sprague-Dawley male rats. It appeared that DEM and particularly CFA treatments were associated with a significant decrease in blood pressure in DOCA-salt treated rats, and an accentuation of the decreases in body weights in both diet supplemented groups. This was not associated with increases in NO production in the liver. In contrast, hepatic lipid peroxidation was significantly decreased in both DOCA-salt treated and untreated groups on DEM and particularly on CFA supplemented diet. The protective effects of CFA and DEM against hepatic cellular damage could be involved in the decreases in blood pressure in DOCA-salt treated rats, where CFA was more efficient than DEM. In CFA supplemented groups, there was a strong increase in hepatic superoxide dismutase (SOD), glutathione-peroxidase (GSH-Px), and catalase (CAT) activities and in DEM supplemented groups, increases in SOD and CAT activities and in GSH levels were observed. Our data suggest that normalization of blood pressure in DOCA-salt treated rats by CFA was due to an enhancement of the half-life of NO while DEM increased its availability

Strain difference (WKY, SPRD) in the hepatic antioxidant status in rat and effect of hypertension (SHR, DOCA). Ex vivo and in vitro data.

International audienceWe assessed the hepatic antioxidant status of spontaneously (SHR) and desoxicorticosterone acetate (DOCA)-induced hypertensive rats and that of respective normotensive Wistar Kyoto (WKY) and Sprague-Dawley (SPRD) rats. For this we evaluated, ex vivo in liver cytosols, reduced glutathione (GSH) content, glutathione-related enzyme (peroxidase, reductase and transferase) activities as well as the rate of lipid peroxidation in 9-11 week-old rats. The antioxidant status and the cytotoxicity of acetaminophen, a radical- and hydrogen peroxide-mediated hepatotoxic compound, were also assessed in vitro in cultured hepatocytes isolated from hypertensive (SHR, DOCA) and normotensive control (WKY, SPRD) rats. Our results suggest that a difference exists in the hepatic antioxidant status between rat strains, with GSH levels being lower (-15%) and lipid peroxidation rate higher (+30%) in WKY compared to SPRD rats. In hepatocyte cultures from WKY rats, both GSH content and catalase activity were lower (-30 and -70% respectively) compared to hepatocyte cultures from SPRD rats. This was associated with a 35% higher cytotoxicity of acetaminophen in cultured hepatocytes from WKY rats compared to that in hepatocytes from SPRD rats. Hypertension in DOCA rats (mmHg: 221+/-9 vs. 138+/-5 in control SPRD rats) was associated with decreases (about 30%) in both glutathione peroxidase (GSH-Px) and catalase activities, ex vivo in livers and in vitro in hepatocyte cultures. Hypertension in SHR (mmHg: 189+/-7 vs. 130+/-5 in control WKY rats) was also associated with decreases (about 50%) in GSH-Px activity, ex vivo in livers and in vitro in hepatocyte cultures but catalase activity was not modified. The IC50 of acetaminophen was also lower in hepatocytes from hypertensive rats compared to respective controls, which could be related to the weakened antioxidant status in hepatocytes from hypertensive rats. Our data thus suggest that hepatocyte cultures are appropriated tools in which to assess hepatotoxicity and hepatoprotection in hypertension

Antioxidant status, lipid peroxidation, mixed function oxidase and UDP-glucuronyl transferase activities in livers from control and DOCA-salt hypertensive male Sprague Dawley rats.

International audienceThe effects of DOCA-salt hypertensive treatment on hepatic glutathione-dependent defense system, antioxidant enzymes, lipid peroxidation, mixed function oxidase and UDP-glucuronyl transferase activities were investigated in male Sprague Dawley rats. Compared with controls, DOCA-salt hypertensive rats had lower body weights (linked to liver hypertrophy). Mixed function oxidase and p-nitrophenol-UGT activities were not affected by the treatment but a significant lower rate of the glucuronoconjugation rate of bilirubin (p < 0.001) was observed in DOCA-salt hypertensive rats. While cytosolic glutathione contents and glutathione reductase activity were not affected, glutathione peroxidase (p < 0.001), glutathione transferase (p < 0.001) and catalase (p < 0.01) activities were decreased and associated with higher malondialdehyde contents (p < 0.001) in treated rats. The imbalance in liver antioxidant status (increasing generation of cellular radical species), associated with increases in lipid peroxidation, suggests that oxidative stress might be directly related to arterial hypertension in DOCA-salt treated male Sprague Dawley rats

Noise Annoyance from Industrial and Road Traffic Combined Noises: A Survey and a Total Annoyance Model Comparison

International audienceThe literature on noise annoyance emphasizes that acoustical factors cannot totally explain the annoyance felt by a population exposed to community noises, and that some non-acoustical factors have an effect on annoyance. This research paper deals with the annoyance caused by combined noises coming from road traffic and an industrial site. This type of combination has been very little studied to date. An . in situ study was conducted in an area of a French town exposed to these two noise sources. To investigate the annoyance caused by these combined noises, the work involved both a mapping of the industrial and road traffic noises present in the survey area and a questionnaire designed to evaluate the noise annoyance experienced by residents and to identify the factors that probably influence noise annoyance. The results highlight the link between the noise levels measured and the annoyance felt by the respondents. They also show that certain non-acoustical factors have an impact on annoyance felt. Indeed, the results highlight a positive correlation between fear of industrial sites and the annoyance expressed. They also show correlations between some items to evaluate noise sensitivity and the annoyance expressed. No significant correlation has been found between annoyance and the other non-acoustical factors such as age, sex and length of residence. Finally, several total annoyance models were tested for this noise combination. Two of them, namely the strongest component model and a proposed perceptual version of the mixed model, were able to better predict total annoyance than the other tested models