[Tobacco and oral health. Questionnaire about knowledge, practices, and opinions among dentists in Berlin]. / Tabak und Mundgesundheit. Umfrage zu Wissen, Ansichten und Verhalten bei Berliner Zahnärzten.

AIM: The aim of the present study was to investigate knowledge, practices, and opinions on tobacco and oral health among dentists of the Berlin Dental Association using a questionnaire. MATERIALS AND METHODS: Questions focussed on smoking habits, knowledge about oral malignancies and premalignancies and practical approaches to screening for oral mucosal diseases and other associations of tobacco with oral changes. The questions related to risk factors and behavioural counselling for patients and associated constraints. RESULTS: Of a total of 4000 questionnaires sent, 483 were received for evaluation (12.1%). Of respondents 9.5% were regular smokers. The median number of oral malignancies observed was 3. Knowledge about some associations of oral changes such as wound healing was adequate. A total of 93.1% of respondents would refer patients with oral lesions. Only 35% take a regular history of both tobacco and alcohol consumption and 26.6% explain the side effects of tobacco. Some 73.4% believed that the dentist could play a role in anti-tobacco counselling. Limiting factors were lack of training and of competence in anti-tobacco counselling. CONCLUSIONS: This study shows that there still is a considerable need for improvement of knowledge and for provision with effective anti-tobacco teaching material. Since most of the respondents thought that the dentist should play a role in anti-tobacco counselling, adequate programmes in Germany should be inititated and followed up.

Diel changes in the specific growth rate and mean cell volume of natural bacterial communities in two different water masses in the Irish sea.

Diel changes in the specific growth rates of natural bacterial communities as a whole and of different groups within the communities were followed over 2 days during July 1982, in stratified waters in the vicinity of a shallow sea tidal mixing front in the Irish Sea. Waters well above (4 m) and below (60 m) the thermocline were enclosed in dialysis bags and incubated in situ. The results show that there were periods of altered growth rates of the whole bacterial community and synchronous cell division of morphological groups. An increase in mean cell volume within both 4 and 60 m communities preceded an increase in specific growth rates, with a resultant decrease in the mean cell volume. Above the thermocline the whole bacterial community, as well as the rod and coccoid forms, doubled in number once a day. The doubling time of the whole bacterial community at 60 m was 2 days and slower than that at 4 m. This was due to a slower doubling time (3 days) for the coccoid forms. Rod forms at the two depths had a similar doubling time (1 day). The time of day when maximum division rate occurred was also different in the two water masses. At 4 m more coccoid forms divided during the night, whereas at 60 m more divided during the day. Conversely, at 4 m more rod forms divided during the day, whereas at 60 m more divided at night.These data indicate that the bacterial community and members of the community may be adapted to exploit the diurnal rhythms of dissolved organic carbon (DOC) release by other organisms and that portions of the bacterial community may therefore be more active at certain times of the day. The diurnal growth of the bacterial community may thus vary between different water masses and largely reflects the differences in the chemical and biological characteristics of the two water masses investigated.