Regular physical activity is recognized as an effective health promotion measure. Among various activities, swimming is preferred by a large portion of the population. Although swimming is generally beneficial to a person's overall health, recent data suggest that it may also sometimes have detrimental effects on the respiratory system. Chemicals resulting from the interaction between chlorine and organic matter may be irritating to the respiratory tract and induce upper and lower respiratory symptoms, particularly in children, lifeguards and high-level swimmers. The prevalence of atopy, rhinitis, asthma and airway hyper-responsiveness is increased in elite swimmers compared with the general population. This may be related to the airway epithelial damage and increased nasal and lung permeability caused by the exposure to chlorine subproducts in indoor swimming pools, in association with airway inflammatory and remodelling processes. Currently, the recommended management of swimmers' respiratory disorders is similar to that of the general population, apart from the specific rules for the use of medications in elite athletes. Further studies are needed to better understand the mechanisms related to the development or worsening of respiratory disorders in recreational or competitive swimmers, to determine how we can optimize treatment and possibly help prevent the development of asthma.
[Show abstract][Hide abstract] ABSTRACT: Prevalence of asthma and allergies in top athletes is high. However, most previous studies did not include a general population comparison group. We aimed to compare the prevalence of asthma, allergies and medical treatment in different groups of German top athletes to the general population.
Prior to the 2008 Summer Olympic Games, 291 German candidates for participation (65%) completed a questionnaire on respiratory and allergic symptoms. Results were compared to those of a general population study in Germany (n = 2425, response 68%). Furthermore, associations between types of sports and the self-reported outcomes were calculated. All models were adjusted for age, sex, level of education and smoking.
Athletes reported significantly more doctors' diagnosed asthma (17% vs. 7%), more current use of asthma medication (10% vs. 4%) and allergic rhinitis (25% vs. 17%) compared to the general population. After adjustment, top athletes only had an increased Odds Ratio for doctor's diagnosed asthma (OR: 1.6; 95% CI 1.1-2.5). Compared to the general population, athletes in endurance sports had an increased OR for doctor's diagnosed asthma (2.4; 1.5-3.8) and current use of asthma medication (1.8; 1.0-3.4). In this group, current wheeze was increased when use of asthma medication was taken into account (1.8; 1.1-2.8). For other groups of athletes, no significantly increased ORs were observed.
Compared to the general population, an increased risk of asthma diagnosis and treatment was shown for athletes involved in endurance sports. This might be due to a better medical surveillance and treatment of these athletes.
[Show abstract][Hide abstract] ABSTRACT: This paper introduced the experimental results of the corona
current characteristic of insulator strings at high alternating
voltages. The experiments show that the corona current pulses have
statistic characteristic and are distinct at different voltages and
different environmental condition, such as humidity and contamination.
After the establishment of several fuzzy membership functions of
humidity and contamination by a large number of experiments, the authors
proved that the fault insulators could be distinguished from the
transmission line insulator strings by the combination of statistic
N-Ψ graph method and fuzzy logical reasoning, and the correctness of
this method has been verified in the laboratory by the 110 kV simulation
transmission line. The most important advantages of this method are safe
Electrical Insulating Materials, 2001. (ISEIM 2001). Proceedings of 2001 International Symposium on; 02/2001
[Show abstract][Hide abstract] ABSTRACT: The SMOS project (CNES/ESA) aims at developing a L-band
interferometric radiometer able to provide global estimates of surface
soil moisture (w<sub>s</sub>) with a sampling time of 2-3 d. Several
studies showed that the assimilation of w<sub>s</sub> time series enable
one to retrieve the root-zone water content, provided the atmospheric
forcing is available from ancillary information. Two real cases of
variational assimilation of w<sub>s</sub> are presented. A simple
iterative optimization of the direct model is applied to the ISBA
(Interactions between Soil, Biosphere, and Atmosphere) surface scheme.
The next step is the direct assimilation of brightness temperatures as
likely to be observed from space. A first example of soil moisture and
vegetation characteristics analysis using L-band radiometric
measurements and the ISBA model is presented. A field campaign was set
in Southwestern France in order to validate such an approach using a
long enough data-set
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