Search results for "Environmental noise"
showing 7 items of 27 documents
Analysis of ecological shifts in the two‐age structured population model with Allee effect and environmental noise
2020
We study noise-induced transformations in the two-age structured population model with the Allee effect and environmental fluctuations. In this bistable model, ecological shifts are associated mathematically with random transitions between basins of coexisting attractors. The following phenomena are revealed and studied: (i) noise-induced extinction, (ii) stochastic regeneration, and (iii) excitement of random mixed-mode oscillations. Constructive abilities of the analytical method of confidence domains are demonstrated in the parametric study of these phenomena.
Stochastic model for a biological complex system: analysis of the bacterial growth in food products
2012
The Physics of Complex Systems has recently taken a more and more important role in the description of natural systems because of the interactions, both deterministic and noisy, between such systems and the environment. In particular the noise plays a relevant role in biological systems, whose dynamics is strongly influenced by environmental variables subject to random fluctuations. In this work a stochastic model is exploited to reproduce the growth of bacteria in food of animal origin. Specifically the dynamics of a bacterial species, Listeria monocytogenes, is analyzed in the presence of lactic acid bacteria (LAB) during the period of the fermentation of meat products. The model, based o…
The impact of noise on the population of an urban centre in Valencia (Spain)
1997
Acoustic contamination in residential areas is a generalized problem. This paper reports the results of a survey trying to evaluate this contamination in the historical center of Valencia and about its effects upon that district's residents. A total of 700 residents in 11 different neighbourhoods of the city of Valencia were interviewed; at the same time environmental noise was determined at 225 different points within the area of study. In the historical center of Valencia, there exists an important problem of environmental noise and the daily levels clearly exceed the recommended limits.
A social survey on the effects of environmental noise on the residents of Pamplona, Spain
1998
Abstract An extensive noise survey carried out in the city of Pamplona, Spain over 2 years has allowed us to elaborate a detailed daytime acoustic map of this city. The degree of noise annoyance in the community and its relationship with the measured noise levels has also been studied by means of a social survey.
Community response to environmental noise in Valencia
1990
Abstract In Valencia, Spain, 263 residents were interviewed at five different locations in order to investigate the subjective response to environmental noise in urban areas. External noise levels were measured over five consecutive days at each site. Noise levels were high in two of the selected sites ( L eq 24h about 75 dBA) and lower in the other two ( L eq 24h about 65 dBA). The fifth location had a night noise problem because of the presence of many leisure places (pubs, restaurants, etc.). The scores of the sample with their satisfaction with their neighbourhood were notably higher in the quiet than in the noisy areas (83% and 64% respectively). Road traffic and pub noise (in the fift…
Environmental stressors and cardiovascular risk: Impact of environmental noise exposure on vascular oxidative stress and damage
2018
Epidemiological studies have demonstrated that traffic noise exposure is associated with cardiovascular diseases such as arterial hypertension, myocardial infarction and stroke. Persistent chronic noise exposure increases the risk of cardiovascular and metabolic diseases such as arterial hypertension, coronary artery disease, diabetes and stroke. Large epidemiological studies (reviewed in Munzel et al. Eur. Heart J. 2017, 38 (8):550–556) point towards a link between the incidence of ischemic heart diseases and exposure to noise, supporting its role as an independent cardiovascular risk factor. Recently, the underlying molecular mechanisms leading to noise-dependent adverse effects on the va…