(n.) An instrument for observing or showing the positions of the stars. It is now disused.
(n.) A stereographic projection of the sphere on the plane of a great circle, as the equator, or a meridian; a planisphere.
Example Sentences:
(1) Technical issues with its engines meant L'Astrolabe did not enter the ice field at all.
(2) The governess was always getting muddled with her astrolabe, and when she got specially muddled she would take it out of [sic] the Wart by rapping his knuckles.
(3) This 166-metre Chinese ship, whose name means Snow Dragon, will now regroup with the smaller L'Astrolabe, the French vessel sent from the nearby Antarctic base, Dumont D'Urville, which is 18.5 nautical miles from the Shokalskiy.
Sextant
Definition:
(n.) The sixth part of a circle.
(n.) An instrument for measuring angular distances between objects, -- used esp. at sea, for ascertaining the latitude and longitude. It is constructed on the same optical principle as Hadley's quadrant, but usually of metal, with a nicer graduation, telescopic sight, and its arc the sixth, and sometimes the third, part of a circle. See Quadrant.
(n.) The constellation Sextans.
Example Sentences:
(1) Treatment needs were determined by the worst periodontal score per sextant.
(2) Pathologic pockets of 6 mm or more were found in 1.3 and 0.3 sextants in the diabetic and control group subjects, respectively (P less than 0.001).
(3) Neither were any differences found in the periodontal condition related to the duration and control of diabetes, whereas diabetics with advanced retinopathy demonstrated more sextants with deep pockets.
(4) A randomized four-sextant treatment design was used.
(5) The value of digital rectal examination, computerized tomography, magnetic resonance imaging, prostate-specific antigen, transrectal ultrasonography, and systematic-sextant biopsy in the identification of lymph node-positive patients before radical prostatectomy was analyzed in 103 men who had pelvic lymph node dissection, CT had a sensitivity of only 7% and a specificity of 96% in detecting lymph nodes, whereas magnetic resonance imaging had a sensitivity of 50% and a specificity of 100%.
(6) 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).
(7) The mean number of missing sextants was also significantly higher in diabetics.
(8) Very few patients had 'healthy' periodontal sextants at the first visit; the most frequent CPITN category was 3.
(9) Any child with two or more sextants or teeth with CPITN code 3 or one sextant code 4 was taken for a radiographic and full clinical examination.
(10) The mean number of sextants requiring scaling was 0.6 per person at age 17 in Espoo as compared to 4.5 at 18.5 yr of age in Chiangmai.
(11) There are broad differences in the numbers of healthy sextants between developing countries and those which are highly industrialized.
(12) Straight rods, fusiforms and motile rods correlated negatively to the number of healthy sextants per subject.
(13) In general, females were healthier than males, had a significantly greater number of healthy sextants, less sextants with calculus and less sextants with deep pockets.
(14) Posterior sextants with CPITN Code 4 were more likely treated with surgery than sextants with CPITN Code 3.
(15) per sextant in the Spaniard population under 20 years of age.
(16) One maxillary sextant was splinted, while the other was unsplinted.
(17) Four pockets per patient, one in each posterior sextant, were chosen.
(18) Partial mouth random recording (2 upper and 1 lower or 1 upper and 2 lower sextants) was made by CPITN of 150 sextants, and at 6 sites around each tooth in each sextant for each index using a pressure-sensitive probe, with Newman tip and Williams markings, and a WHO 621 tip, probing pressure 0.25 N. Ranges of each index were compared with corresponding CPITN data.
(19) Surgical therapy was effective over all levels of disease severity and was the preferred form of therapy with respect to reduction of probing depth except for sextants exhibiting 4 to 5 mm pockets.
(20) While plaque and calculus were present in many sextants, there was little intense gingivitis and signs of advanced periodontal diseases were rarely present.