(n.) The time when the sun enters one of the equinoctial points, that is, about March 21 and September 22. See Autumnal equinox, Vernal equinox, under Autumnal and Vernal.
(n.) Equinoctial wind or storm.
Example Sentences:
(1) Dose rates are integrated with respect to time to obtain estimates of mean doses for various periods during clear days at Rockville in mid summer and near the autumnal equinox.
(2) The date of the spring equinox varies from 19 to 21 March depending on location and corrections due to the mismatch between the Gregorian calendar, which logs 365 days a year, and the duration of Earth's orbit around the sun, which takes 365.25 days to complete.
(3) Plasma melatonin was measured at the summer and winter solstices and the autumn and spring equinoxes in Romney Marsh sheep held under natural conditions in South Australia (35 degrees S).
(4) Female Suffolk sheep were pinealectomized around the vernal equinox to eliminate the major environmental input to the reproductive system (photoperiod) and then either isolated from, or maintained with, pineal-intact gonad-intact sheep.
(5) At 6-14 days after each of the solstices and equinoxes, six females were exposed to a photoperiod equivalent to the natural day length at these times.
(6) Seven out of 14 acrophases of cyclic indices occurred just before autumnal equinox and three before vernal equinox.
(7) While the equinox signals a time when day and night are equal, the moment when both share 12 hours apiece happens days earlier, because of atmospheric effects.
(8) At approximately the spring and autumn equinox and the summer and winter solstice, rats were killed at 3-h intervals over a 24 h period and their serum thyroxine (T4), triiodothyronine (T3) and reverse T3 levels were determined.
(9) At higher latitudes, where changes in daylength are pronounced, a steep increase in human conceptions coincides with the vernal equinox.
(10) With less than a week to go until the Sun crosses northwards over the equator at the vernal equinox, it is showing real signs of rebirth in another respect.
(11) Downstream of the zone, a man called Sanders arrives at a remote town called Port Matarre just before the equinox.
(12) In a group of six rams, the seasonal changes of melatonin were characterized in samples collected at 10-min intervals for an equal period before and after the median of the scotophase during the spring (March) and the autumn (September) equinoxes, and also during the summer (June) and the winter (December) solstices.
(13) The mitotic activity in the adenohypophysis of male rats during a 24 hours' cycle has been studied at the time of the spring equinox.
(14) Shortly after the autumnal equinox, three groups of ovariectomized ewes bearing s.c. Silastic implants of estradiol were placed in different lighting environments.
(15) In both stations, at solstice and equinox, thirty 15 month-old Holstein bulls were blood sampled for plasma LH, testosterone, thyroxine and triiodothyronine determination.
(16) Swedish law would not allow them to be sued in Sweden, but the British publishers of the paper, Equinox, withdrew it under the threat of a libel suit in the English courts.
(17) Interpreted according to this hypothesis, the sexual cycle of the mink under natural photoperiodic conditions is also explained by seasonal gonadotropic stimulation beginning after the autumn equinox when in our latitudes daily light duration is less than 12 hr.
(18) At the equinoxes and solstices, unrestricted subjects had hourly urine collections followed by venous blood sampling taken under natural light conditions for 24 hours.
(19) For those in the southern hemisphere, the same equinox marks the arrival of autumn and longer nights.
(20) The rats were analyzed at 3 h intervals during 24 h approximately at the time of the vernal and autumnal equinox and at the winter and summer solistice.
Solstice
Definition:
(v. i.) A stopping or standing still of the sun.
(v. i.) The point in the ecliptic at which the sun is farthest from the equator, north or south, namely, the first point of the sign Cancer and the first point of the sign Capricorn, the former being the summer solstice, latter the winter solstice, in northern latitudes; -- so called because the sun then apparently stands still in its northward or southward motion.
(v. i.) The time of the sun's passing the solstices, or solstitial points, namely, about June 21 and December 21. See Illust. in Appendix.
Example Sentences:
(1) Regression occurred after the summer solstice and recrudescence occurred after the winter solstice.
(2) Immunization to provoke a persistent anti-melatonin antibody response at the winter solstice resulted in significantly increased greasy fleece weight, % cashmere yield, and mass of cashmere produced, but no change in fibre diameter in both sexes.
(3) Five adult pasture-bred French Friesian cows were used to qualify the circadian profile and characterized pulsatility of plasma melatonin, and to estimate melatonin secretion rate, around the summer solstice.
(4) Ovaries, pituitary gland, hypothalamus and a blood sample were collected from six groups of mares (6-12 mares per group) at death, 1 week before day of the winter solstice and 1, 2, 3 and 12 weeks afterwards.
(5) Plasma melatonin was measured at the summer and winter solstices and the autumn and spring equinoxes in Romney Marsh sheep held under natural conditions in South Australia (35 degrees S).
(6) In June, the owner, Oliver Poiss, threw a huge summer solstice party with six wild boar roasting on spits and a $10,000 equipment giveaway.
(7) The following year, three animals were transferred from natural to summer solstice daylength on February 25 and were held on the artificial photoperiod until September 30.
(8) The solstice marks the peak of summer and takes place when the sun is at its highest point in the sky.
(9) Nobody knows what they mean: they may be solstice markers, clan symbols, decorative motifs or simply ancient graffiti.
(10) On the summer solstice, 3 groups of ovariectomized ewes (n = 6) bearing s.c. Silastic implants of estradiol (OVX + E) were placed in different day length treatments: 1) natural photoperiod; 2) artificial photoperiod, stimulating natural day lengths; or 3) artificial photoperiod equivalent to that of the summer solstice (16.25L).
(11) A control group was held on the winter solstice day length (10L:14D) until the end of the study in mid-March.
(12) At 6-14 days after each of the solstices and equinoxes, six females were exposed to a photoperiod equivalent to the natural day length at these times.
(13) The amplitude of the day-night rhythm decreased in such a way that the nocturnal peak of melatonin completely disappeared during the winter solstice.
(14) Castrated rabbits were perfused during spring; castrated rabbits with testosterone capsule implants were perfused during late spring, around summer solstice and in summer and castrated rabbits with placebo implants were perfused during periods (iii) and (iv).
(15) Perfusions were performed in the following four periods, defined by season and time after testosterone and placebo implants: (i) spring; before implants, (ii) late spring; 0-2 weeks after implants, (iii) summer solstice; 2-4 weeks after implants and (iv) summer; 4-6 weeks after implants.
(16) At approximately the spring and autumn equinox and the summer and winter solstice, rats were killed at 3-h intervals over a 24 h period and their serum thyroxine (T4), triiodothyronine (T3) and reverse T3 levels were determined.
(17) (3) The time of onset of the breeding season does not depend upon the decreasing photoperiod after the summer solstice, nor does it require the photoperiod to stop increasing as the summer solstice approaches.
(18) Animals maintained in natural photoperiods or simulated natural changes in daylength after the winter solstice all entered reproductive quiescence by early February.
(19) This marginal delay in the arrest of reproductive activity seen in both experiments indicates that the lack of decrease in day length around and after the winter solstice may play some role in timing the end of the breeding season.
(20) The importance of decreasing photoperiod after the summer solstice in determining the onset and duration of the breeding season was tested by housing ewes from the summer solstice in either a simulated natural photoperiod or a fixed summer-solstice photoperiod (18 h light:6 h dark; summer-solstice hold).