The culture of Chlorella vulgaris in a recycled supernatant: effects on biomass production and medium quality.

Reusing supernatant of microalgae culture medium can have inhibitory or toxic effects on the biomass production because of the release of organic metabolites by cells in the culture medium during their growth. This work investigated the impact of Chlorella vulgaris medium recycling on culture productivity, cells quality and accumulation of excreted metabolites in the culture medium. No significant impact on the C. vulgaris growth was observed after 63days of recycling, the productivity remained stable at around 0.55kgm(-3)day(-1). Organic matters accumulated in supernatant were identified as biopolymers (BP) poor in nitrogen and with a size above 40kDa (probably polysaccharides), and small organic molecules (SOM) richer in nitrogen with a molecular size ranging from 1 to 3kDa. The concentration of biopolymers in the supernatant increased till to a maximum and then decreased, possibly consumed by bacteria, whereas small organic compounds accumulated in the medium.

Development and validation of a minimal growth medium for recycling Chlorella vulgaris culture.

When microalgae culture medium is recycled, ions (e.g. Na(+), K(+), Ca(2+)) that were not assimilated by the microalgae accumulate in the medium. Therefore, a growth medium (HAMGM) was developed that included ions that were more easily assimilated by Chlorella vulgaris, such as ammonium one (NH(4)(+)). Recycling performance was studied by carrying out 8-week continuous cultivation of C. vulgaris with recycled HAMGM medium. No loss of biomass productivity was observed compared to culture in a conventional medium, and accumulation of ions over time was negligible.

Smoking behavior and opinions of French general practitioners.

This report examines smoking prevalence, sociodemographic factors, and the opinions of French general practitioners (GPs) about tobacco control policies. Data from the CFES (Comité Français d'Education pour la Santé) national survey on general practitioners included 1013 respondents. The questionnaire was administered by telephone and a response rate of 65% was attained. Instrumentation included variables related to medical practice, sociodemographic characteristics, and opinions about health behavior. Thirty-four percent of physicians were current smokers. A higher proportion of males smoked compared to women (36.1% vs. 24.9%, p < 0.01), and they consumed on average more cigarettes per day (11.2 vs. 8 cigarettes/day, p < 0.05). Slightly more than 52% of physicians regarded their role in reducing nicotine addiction to be important. Doctors who believed that the physician's role was limited were less likely to advise pregnant women to stop smoking (odds ratio = 0.39, p < 0.001), and nonsmokers were more supportive of bans on smoking in public places. Despite the high prevalence of smoking among French physicians, they can still play an important role in reducing smoking among their patients. Medical school curriculum and continuing medical education programs focusing on prevention and cessation in France should be strengthened to help reduce smoking rates among physicians and the general population.

Smoking behavior among French and American women.

BACKGROUND: This paper presents an analysis of the sociodemographic factors related to cigarette smoking prevalence and the number of cigarettes smoked daily among nationally representative samples of 18- to 64-year-old French (n = 1,956) and American (n = 20,234) women. METHODS: This analysis combines 2 separate years (1992 and 1993) of data collected by the National Health Interview Survey in the United States and the Comité Francais d'Education pour la Santé in France. Weighted data analysis of the effects of age, employment status, education, and socioprofessional status was conducted using both SPSS and the SUDAAN complex sample survey analysis program. RESULTS: The prevalence of smoking among French female smokers was significantly higher than among American women (30.8% vs 26.3%) and particularly among the younger age groups. However, the average number of cigarettes smoked per day was appreciably and significantly lower for French women (12.3) than for American women (18.2). Multivariate logistic regression analysis revealed statistically significant interaction terms differentiating the impact of marital status, age, and education on the smoking status of French and American women, as well as the sociodemographic determinants of the number of cigarettes smoked. Education was inversely related to smoking among American women but positively associated with the smoking behavior of French women. CONCLUSIONS: Differences in the smoking behavior of French and American women support the view that sociodemographic factors do not affect the smoking behavior of women in Western industrialized countries similarly and reinforce the importance of international public health measures targeting the increasing rate of smoking among women.

[Attitude and behavior of hospital personnel toward smoking]. / Attitudes et comportement du personnel hospitalier face au tabagisme.

Due to a lack of data available at the national level, on smoking behaviour of hospital staff, a survey was carried out in a representative sample of hospitals. This survey, which will be repeated in the future, should enable to evaluate preventive actions at hospital and to measure the implication level of the hospital staff in tobacco prevention. The analysis of data collected among 3082 persons shows that a third of the hospital staff smokes. Among these persons a certain part smoke at their working place, this proportion is varying considerably with the working area in the hospital. The more this area is close to the patient the less is hospital staff smoking. More than one third of the interviewers (37.3%) think that trying to convince people to stop smoking is part of their role: this opinion varies considerably depending on the professional activity in the hospital. In addition a very large majority (81.4%) of the hospital staff considers that it has an exemplary role to play in front of patients. This belief is shared equally by all the different groups of staff. The smoking prevalence among hospital staff is equivalent to that of the general population; this underlines the need and the necessity to realize anti-tobacco campaigns among this health care population. Moreover since the exemplary role they have to play, is very well accepted, preventive actions could rely on a good level of participation.

[Evaluation of the use of tobacco restrictions in French enterprises]. / Evaluation de l'application des limitations au tabagisme dans les entreprises françaises.

This survey evaluates the respect of tobacco legislation at workplace among a random sample. It shows that a small and limited information can increase the awareness of the companies' managers. More than one out of three companies replied that new measures were implemented. In the majority of cases (more than three out of four) members of the board of directors believe that all the measures are well respected. A little bit less members of the employees are of the same opinion, with an exception for the smoker's lounge. Many of them believe, however, that the smoking restrictions are respected.

[Opinions and behaviors of French adolescents confronted with tobacco in 1995]. / Opinions et comportements des adolescents français face au tabac en 1995.

BACKGROUND: The French Committee for Health Education has observed the adolescent's opinions and behaviours on smoking since 1977. POPULATION AND METHODS: The surveys were carried out on a representative sample, made up by quotas method, of the population concerned (12 to 18 years old). The last data (1995) were analyzed in order to evaluate present smoking behaviour and to measure the influence of the social environment. RESULTS: In 1995 more than one out of three (35.1%) young people smoked at least once in a while; this smoking prevalence was nearly the same among boys (34.7%) as among girls (35.5%). Since 1977, the long-term trend of the rates showed a decrease and the monitoring of the starting age proved that adolescents began to smoke more and more later. The influence of peer and parents smoking was strong. The socioeconomic status of the family and also the amount of pocket money were other determinants of smoking. The family and school atmosphere played an important role as well. CONCLUSIONS: The influence of all these environmental variables on the young person's smoking behaviour underlines the necessity of developing simultaneously campaigns aimed at young people and actions among different populations. The emergence of a positive status for the non-smoker supports the choice of the strategies for the latest campaigns.

Is tobacco use finally decreasing in France?

Tobacco is responsible for a third of all cancers, as well as a large proportion of cardiovascular and chronic respiratory diseases. Monitoring of the tobacco epidemic is necessary everywhere, in particular in non-English-speaking countries where until recently no decrease was seen in tobacco consumption. National population surveys have been conducted repeatedly on representative samples of both the adolescent and adult French population to evaluate trends in smoking behavior. A decrease can be noted in the population of adolescent smokers of both sexes-from 46% in 1977 to 30% in 1991. Among adults the overall figure is rather stable due to contrasting trends, with a general decrease among men (although not among young men aged 18 to 24) counterbalanced by an increase among women. Future health education efforts should focus on women of all ages but should not neglect young men, although the decrease observed among girls and boys is promising.

[Smoking and social class in France 1974-1991]. / Tabagisme et classe sociale en France de 1974 à 1991.

We examined trends in cigarette smoking behaviour in France from 1974 to 1991 separately for men and women as well as according to social class indicators. Overall, cigarette smoking prevalence has declined among men but has increased among women over the 18-year period which was taken into consideration. Analysis by social class groupings shows, among men, that the decrease is greater among higher level executives, professionals and academics and occurred as early as 1983. Among women, there is only a slight and recent downward trend limited to those of higher socio-economic status. These findings are similar to those of other southern European countries, such as Italy or Spain, but are not as yet comparable to what has been observed over the last twenty years in northern Europe, the United Kingdom or the United States of America.

[Epidemiology of tobacco smoking in France]. / Epidémiologie du tabagisme en France.

The authors analyse the results of the last national survey on the prevalence of tobacco smoking, carried out by the French Committee for health education in 1992. The smoking percentage is analyzed by sex, age, instruction level and, parents smoking behaviour. These results are also compared with data from previous surveys performed since 1977 in young people and since 1974 in adults. A decreasing trend is noticed in young people from 46% in 1977 to 34% in 1992. This optimistic evolution however has to be relativised, taking into account the increase of the consumption level. For adults, the general trend is the stability of the smoking percentage (40% of the population smoke) but the evolution shows totally different results for males and females. The smoking prevalence is decreasing among men (from 59 to 48%), whereas it is increasing among women (from 28 to 33%). Moreover the smoker percentage among young adult women (18-24 year old) is nearly the same as for young adult men (63.4 vs 63.8%). The data provided by this survey enables the authors to set priorities in the campaign against tobacco smoking.

[Current development of smoking in young people in France]. / Evolution récente du tabagisme des jeunes en France.

Two sets of data, collected independently, have been analysed to study the recent evolution of tobacco smoking in France among young people. For the first time a trend towards a reduction of this habit has been observed.