ISSN:0022-1945    

DOI:10.1080/09291017309359392

出版商:Taylor & Francis Group    

年代:1973

数据来源: Taylor

摘要:

Suspensions of liver cells prepared from young female rats and kept under a light‐dark cycle show a circadian rhythm in tyrosine: 2‐oxoglutarate aminotransferase activity. The rhythmicity, which is obviously not homologous to that one observed in the whole animal, persists for some days under constant illumination. In the course of about two weeks, however, the rhythm is damped out. After 3 weeks under constant conditions, rhythmicity can be induced again by a one‐hour period of darkness. In the arhythmic cultures, average enzyme activity is much lower than in the rhythmic cultures. The transition from the non‐oscillatory to the oscillatory state is accompanied by an increase in TAT synthesis, which can be blocked by cycloheximide and partially by α‐amanitine.

ISSN:0022-1945    

DOI:10.1080/09291017309359393

出版商:Taylor & Francis Group    

年代:1973

数据来源: Taylor

摘要:

From the observational material compiled during the period 1874–1971 it becomes evident that the 11‐year and 80‐year cycles can be deduced from the frequency of sunspots easily visible to the naked eye. Thus these solar cycles could have been detected long before the invention of the telescope if in ancient and medieval times attention had been paid to the appearances of conspicuous spots on the sun.

ISSN:0022-1945    

DOI:10.1080/09291017309359394

出版商:Taylor & Francis Group    

年代:1973

数据来源: Taylor

摘要:

Honey bees entering and leaving their hive were registered with photoelectrical counters. By using this method it was possible to measure flight activity cycles of high and low levels. Considering the effect of reproduction and mortality rates, the observed rhythm of activity could be attributed to the phases of the moon. Observations of outdoor flight activity in Morocco, under weather conditions permitting, from June to October and indoor flight activity in a controlled environment rearing room in Germany from November 1968 to August 1970 had the following results:

ISSN:0022-1945    

DOI:10.1080/09291017309359395

出版商:Taylor & Francis Group    

年代:1973

数据来源: Taylor

摘要:

Data on self inflicted injuries by poisoning in the Winnipeg, Canada area were compared to the lunar cycle. A statistically significant lunar periodicity was demonstrated for the females in the sample (p<.05) with a greater number of cases occurring during the first quarter and a smaller number occurring during the third quarter of the lunar cycle. The males did not show a lunar periodicity and showed a significantly different distribution than the females in the sample (p<.025). A significant correlation between periods in which a large number of self inflicted injuries occurred and the apogees and perigees of the moon, was found (p<.005). The possibility that factors such as weather with its accompanying electromagnetic processes and/or changes in the intensity of the geomagnetic field are mediating factors in a lunar phase effect on human behavior, is discussed.

ISSN:0022-1945    

DOI:10.1080/09291017309359396

出版商:Taylor & Francis Group    

年代:1973

数据来源: Taylor

摘要:

Subjects were 54 university men (n=26) and women (n=28). Approximately 60 measures of affective, sensorimotor, and cognitive functioning were taken three times weekly for three months. Preliminary analyses of the data indicated that several variables typically reported as cyclical in woman during menses may also be cyclical in men. Autoregressive and power spectral analyses must be performed to test this hypothesis.

ISSN:0022-1945    

DOI:10.1080/09291017309359397

出版商:Taylor & Francis Group    

年代:1973

数据来源: Taylor

摘要:

40 Drosophila species were kept under a light‐dark cycle of 12/12 hrs, at constant temperature and humidity. Locomotor activity was recorded using a method based on the measurement of variations in capacitance. The circadian patterns of the species tested differed with respect to number and phase of maxima and to the occurrence of a resting period in the middle of the light phase. The resting period, which is usually regarded as an adaptation to an arid climate, was also observed in several boreal species.

ISSN:0022-1945    

DOI:10.1080/09291017309359398

出版商:Taylor & Francis Group    

年代:1973

数据来源: Taylor

摘要:

A quantitative technique for analyzing entrainment of circadian locomotor activity is tested with red squirrels(Tamiasciurus hudsonicus), antelope squirrels(Ammospermophilus leucurus), flying squirrels(Glaucomys volans), hamsters(Mesocricetus auratus), and house sparrows(Passer domesticus).These data verify predictions of the theoretical timing maps and demonstrate that the L/D cycle modulates the free‐running rhythm in a highly adaptive manner.

ISSN:0022-1945    

DOI:10.1080/09291017309359399

出版商:Taylor & Francis Group    

年代:1973

数据来源: Taylor

摘要:

Many studies with different animals have shown that biological rhythms are of great importance for adaptation to environmental conditions, in particular to rhythms of seasonal changes. The purpose of this study was to elucidate whether domestic animals, which have been subjected to profound changes through the effect of artificial selection, retain the adaptive rhythm of seasonal changes. In order to solve this problem an attempt was made by comparing the seasonal rhythm in the structure of the hair coat in aboriginal cattle, which has formed during natural selection, with that in breeds subjected to long‐term artificial selection. It has been shown that in aboriginal cattle (southern Zebu cattle and northernYakutian) the seasonal changes in hair coat (length, density, ratio between fractions) have a clearly expressed rhythm. In herds of stud breeds (black‐spot, Jersey) the rhythmic pattern of seasonal changes in the structure of hair coat is lost. This is associated with considerable decrease in adaptive plasticity, which in an evolutionary aspect has the character of degenerative changes. The large variability in the expressivity of the adaptive rhythms in stud breeds makes it possible to restore the lost biological rhythm of adaptive changes through selection.

ISSN:0022-1945    

DOI:10.1080/09291017309359400

出版商:Taylor & Francis Group    

年代:1973

数据来源: Taylor

ISSN:0022-1945    

DOI:10.1080/09291017309359401

出版商:Taylor & Francis Group    

年代:1973

数据来源: Taylor