Search results for " STRESS"
showing 10 items of 3936 documents
Physiological,anatomical and biomass partitioning responses to ozone in the Mediterranean endemic plant Lamottea dianae
2011
Ozone effects on the perennial forb Lamottea dianae were studied in an open-top chamber experiment. Ozone was found to induce reductions in CO 2 assimilation and water use efficiency in the leaves of this species. These reductions were mainly related to a decline in the in vivo CO 2 fixation capacity of Rubisco (V c,max), rather than to stomatal limitations or photoinhibitory damage (F v:F m). In addition to chloroplast degeneration, other observed effects were callose accumulation, formation of pectinaceous wart-like cell wall exudates and phloem alterations. Moreover, ozone exposure significantly reduced root dry biomass. The possible relevance of these adverse effects for Mediterranean f…
Human Drug Pollution in the Aquatic System: The Biochemical Responses of Danio rerio Adults
2021
Simple Summary The release of medicinal products for human use in the aquatic environment is now a serious problem, and can be fatal for the organisms that live there. Danio rerio is a freshwater fish that provides the possibility to study the effects of these pollutants on the health of aquatic organisms. The results of the various existing scientific studies are scarce and conflicting. Here, we review the scientific studies that have analyzed these effects, highlighting that the impacts of drugs are evident in the biochemical responses of these animals. Abstract To date, drug pollution in aquatic systems is an urgent issue, and Danio rerio is a model organism to study the toxicological ef…
Environmental Conditions, Air Pollutants, and Airways
2019
Air pollution is a major problem worldwide, which could be even more serious for athletes who train in urban environments. Exercise increases minute ventilation and exposure to pollutants, but the literature on the effects of air pollution in athletes is relatively scarce, with the exception of chlorine exposure in athletes of aquatic sports and air pollution secondary to ice resurfacing in athletes performing in ice arenas. Although air pollution may exert detrimental effects on athletic performance, little has been published on this topic. The largest body of information regards the impact of air pollution during urban active transport, i.e., walking and cycling in cities, due to the pote…
Stress-induced cytological and chemical adaptations in Cupressus plants from an urban area of Palermo (Italy)
2004
We studied stress-induced cytological and chemical adaptations in Cupressus pollens and needles from the area of Palermo (Sicily, Italy), in polluted and control sites (unpolluted) of urban and suburban areas. Pollen and needle chemical composition were investigated to provide an indicator of contamination of the trees, which were also examined structurally throughout one year. The concentration of particulate with lead was found to be significantly higher in plants at the polluted traffic site. Lead is one of the worst particulate pollutants in cities, especially in the winter season. In trees from the polluted site, all structural analysis revealed displasies. Structural changes, observed…
The Impact of Copper Ions on Oxidative Stress in Garden Cress Lepidium sativum
2017
Abstract Normal oxygen metabolism is an endogenous source of reactive oxygen species (ROS). The source of ROS are also many environmental factors including heavy metals. In certain concentration range, the presence of ROS is necessary to maintain proper cell function. Thus, cells have many mechanisms, which role is focused on maintaining a constant concentration of ROS. Imbalance between the formation of ROS and action of a protective antioxidant system leads to oxidative stress. This may results with a damage to the structure of proteins, lipids and nucleic acids, which in turn can lead to disturbances in the functioning of the cell and even to the death. The aim of the study was to evalua…
Air Quality and Chronic Stress: A Representative Study of Air Pollution (PM2.5, PM10) in Germany.
2019
Objective With rising attention on climate change and the aftermath of burning fossil fuels, there is much concern regarding the effects of air pollution on physical and psychological health. However, the relationship between chronic stress and air pollution is relatively unexplored in humans. Methods By combining German representative data with national pollution data and using step-wise regression analyses, this study investigates how air pollution (particulate matter 2.5 and 10 [PM2.5 and PM10]) impacts ones' chronic stress levels (TICS). Results Results show PM2.5 fine-dust particles significantly affect chronic stress, while PM10 has no such effect. Air pollution (PM2.5), age, and inco…
Cadmium stress effects indicating marine pollution in different species of sea urchin employed as environmental bioindicators
2019
In recent years, researches about the defense strategies induced by cadmium stress have greatly increased, invading several fields of scientific research. Mechanisms of cadmium-induced toxicity continue to be of interest for researchers given its ubiquitous nature and environmental distribution, where it often plays the role of pollutant for numerous organisms. The presence in the environment of this heavy metal has been constantly increasing because of its large employment in several industrial and agricultural activities. Cadmium does not have any biological role and, since it cannot be degraded by living organisms, it is irreversibly accumulated into cells, interacting with cellular comp…
Influence of the Residual Stresses Induced by Shot-Peening on the Oxidation of Zr Plates
2014
The present study evaluates the influence of the residual stress on the oxidation rate of Zr at 650°C. It is shown that the oxidation rate can be substantially decreased by shot-peening. A systematic instigation of the various factors (such as the residual stress, the surface pollution and the chemical composition of the oxidation atmosphere) is realized to separate their influence on the oxidation. The influence of an annealing made after the shot-peening is also considered. One show that the pollution of the surface during the shot-peening process is not responsible for the oxidation rate decrease.
A Study on the Propagation of Plane Stress Waves across the Thickness of a Plate by the Method of Analytic Continuation in Time
2004
The interaction of plane tension/compression waves propagating within a plate perpendicularly to its surface is considered. The analytic solution is obtained by a modified method of characteristics for the one-dimensional wave equation used in problems on an impact of a rigid body on the surface of a plate. The displacements, velocities, and stresses in the plate are determined by the edge disturbance caused by the initial velocity and the stationary force field of masses of the striker and the plate. The method of analytic continuation in time put forward allows a stress analysis for an arbitrary time interval by using finite expressions. Contrary to a stress analysis in the frequency doma…
OXIDASES ACTIVITIES AND ANTIOXIDANT CAPACITY OF MINIMALLY PROCESSED BABY ROMAINE LETTUCE (Lactuca sativa L. CV. DUENDE) CULTIVATED UNDER DIFFERENT SA…
2007
[SPA] El pardeamiento enzimático es uno de los principales problemas implicados en el procesamiento mínimo y en la siguiente conservación de hortalizas de hoja, reduciendo la vida comercial del producto. Se han evaluado las variaciones de las dos principales oxidasas, polifenol oxidasa (PPO) y peroxidasa (POD), así como del contenido en fenoles, del color y de la capacidad antioxidante (metodo ORAC) durante 10 días de conservación a 4 °C de lechuga Baby Romaine (Lactuca sativa L. cv. Duende) mínimamente procesada, cultivada bajo 3 distintas condiciones de salinidad (2,8, 3,8, 4,8 dS/m), para determinar la condición más apta al siguiente procesamiento. Niveles crecientes de salinidad redujer…