ABSTRACT
Atlantic sturgeon Acipenser oxyrinchus surfacing behaviour was investigated in Minas Basin (45° 20' N; 64° 00' W) and the Bay of Fundy with pop-up satellite archival tags (MiniPAT) measuring physical variables (pressure, temperature, light). Of six tags deployed during June and July, five provided pop-up locations and two were recovered after c. 4 months. Analysis of recovered archival data revealed that the frequency of surfacing events was highest (78·9%) when A. oxyrinchus were in Minas Basin at depths <10 m. Surfacing frequency decreased substantially when fish migrated into greater depths of the Bay of Fundy (>40 m). The tidal cycle in Minas Basin had a significant relationship to surfacing frequency, with the most surfacing events (49·5%) occurring on the flood tide, from mid- to high-tide. Surfacing events ranged from 0-12 a day and the maximum number occurred between 2300 and 0300 hours. Maximum surfacing ascent speeds ranged from 0·50 to 4·17 m s-1 and maximum descent speeds ranged from 0·17 to 3·17 m s-1 . Buoyancy control, by gulping air to inflate the gas bladder, is proposed as the main reason for surfacing behaviour in A. oxyrinchus.
Subject(s)
Behavior, Animal , Fishes/physiology , Animals , Atlantic Ocean , Swimming , Temperature , Water MovementsABSTRACT
In 1986 a nationwide dental survey was carried out in The Netherlands. One of the objectives of the study was to assess the periodontal treatment need in the Dutch adult population. A stratified sample of 3526 people aged 15 to 74 years, participated in the study. Based on the Community Periodontal Index of Treatment Needs (CPITN) it can be stated that more than 90% of the adult population of 25 years and over needs oral hygiene education and scaling in one of more sextants (TN2). Complex treatment, scaling and oral hygiene education (TN3) is needed in 19 to 28% of the population aged 45 year and over. The estimated time for performing the necessary periodontal treatments, based on four different time assessments, varied from 12.4 to 31.1 million hours.
Subject(s)
Health Services Needs and Demand , Health Services Research , Periodontal Diseases/epidemiology , Adolescent , Adult , Age Factors , Aged , Humans , Middle Aged , Netherlands/epidemiology , Periodontal Diseases/therapy , Periodontal IndexABSTRACT
A nationwide epidemiological survey was carried out on a stratified sample (age, sex, SES and area) of 2784 dentate people in the age of 15-74 years. Prevalence of plaque, gingivitis, calculus and pockets was recorded. About 85% of the individuals had gingivitis. The percentage of individuals with calculus varied from 40% (15-19 years old) to 76% in the oldest age group (65-74 year). More then 50% of the people, aged 30 and over had pockets greater than 3.5 mm.