摘要:

The electroretinogram (ERG) of the diurnal lizardAnolis carolinensiswas monitored once per hour in constant dark for periods of approximately 5 consecutive days. The amplitude of the b‐wave component of the ERG exhibited a rhythm in all eyes, while the amplitude of the a‐wave component exhibited a rhythm in only 30% of the eyes. These rhythms had a period of approximately 24 hr and their peak amplitudes occurred near projected midday. Constant light masked the b‐wave rhythm, but only produced a phase delay in the a‐wave rhythm. ERGs were also monitored from the nocturnal lizardGecko geckoin constant dark. The amplitude of the b‐wave exhibited a rhythm that had a period of approximately 23 hr, and its peak amplitude occurred near projected sunset. In contrast to the b‐wave, there was no evidence for a rhythm in the a‐wave.

ISSN:0022-1945    

DOI:10.1080/09291018709359942

出版商:Taylor & Francis Group    

年代:1987

数据来源: Taylor

摘要:

Rainbow trout (Salmo gairdneriRichardson) maintained in the laboratory under a fixed artificial 12 hrs light: 12 hrs dark photoperiod exhibited alternating periods of rapid and slow growth. The cycles of growth were rhythmic, and evident in ‘longitudinal’ and ‘transverse’ experimental series. The length of the cycle was approximately two weeks in duration. Peaks of growth rate predicted by least square cosine models describing the relative growth rate patterns were associated with new and full moon suggesting that the lunar calendar is a Zeitgeber used in the regulation of the growth cycles. Changes in growth rate cycles and activity of the fish were associated with the spring equinox, indicating that the fish are sensitive to the event, and that they may re‐adjust their growth rate cycle at that time of the year.

ISSN:0022-1945    

DOI:10.1080/09291018709359943

出版商:Taylor & Francis Group    

年代:1987

数据来源: Taylor

摘要:

The annual pattern of white births in the United States was analyzed for the years 1967 thru 1976. Monthly means for the ten‐year period were obtained individually for each state, and four different temporal patterns were found. The four patterns were found in the “Northwest”; (Washington, Oregon, Idaho, Montana, Utah, and Colorado), “Northeast”; (New York and the New England states, gulf (Florida, Alabama, Mississippi, Louisiana, and Texas), and the “middle”; states. Four mid‐northern states (South Dakota, Minnesota, Wisconsin, and Michigan) seemed on visual inspection to differ, but no statistical difference was detected when tested against the “Northeast”; therefore, these four states were grouped tentatively with the Northeast. A step‐wise regression analysis of the total USA births for the years 1967 thru 1976 provided the familiar bimodal pattern of previous analyses. Confidence intervals for the regression coefficients of the annual sine curve were obtained and the discrepancies with the data described and discussed. The inadequancy of single sine curve representations for these data on births was demonstrated. A brief review of the literature on causation of the complex temporal patterns in births indicates the complexity and suggests that multiple factors may be involved.

ISSN:0022-1945    

DOI:10.1080/09291018709359944

出版商:Taylor & Francis Group    

年代:1987

数据来源: Taylor

摘要:

The ultradian rhythm of movement of the lateral leaflet ofDesmodium gyranscan be entrained by temperature cycles, provided that the entrained Zeitgeber period is less than that of the free‐running period. The rhythm is sensitive to single pulses; the phase response curves show times of large phase advances and of zero changes, but no phase delays. The rhythm is highly temperature dependent with temperature coefficients of around 2.5.

ISSN:0022-1945    

DOI:10.1080/09291018709359945

出版商:Taylor & Francis Group    

年代:1987

数据来源: Taylor

摘要:

Water intake of five dogs was studied in four situations. In situations A and B dogs had free access to food and water. In situations C and D access to food was limited to half an hour in every 24 hrs: at the end of the light phase (situation C) or during the dark phase (situation D). In situation B the light is constant. In the other situations dogs were exposed to an LD 12:12 cycle. Individual results showed: (1) in one dog the water intake was strongly influenced by the LD cycle and slightly influenced by the food intake; (2) in three dogs, fixed food intake determined the water intake while the LD cycle had a slight influence; (3) in one dog only a pronounced inhibitory effect of dark phase and a stimulative effect of food intake on water intake were noted simultaneously. These results show the existence of inter‐individual differences in dogs and the interest of individual studies when the influence of external synchronizers is to be investigated.

ISSN:0022-1945    

DOI:10.1080/09291018709359946

出版商:Taylor & Francis Group    

年代:1987

数据来源: Taylor

摘要:

Stepwise regression allows for an easy selection of the “best”; linear model. For non‐linear models the selection procedure is not as straightforward, relying on a subjective assessment of the normality, independence and trends of the residuals. An approach suggested by Williams and Kloot (1953) is developed into a quantitative procedure for identifying the “best”; non‐linear model. An example using human circadian rhythms is used to demonstrate the procedure.

ISSN:0022-1945    

DOI:10.1080/09291018709359947

出版商:Taylor & Francis Group    

年代:1987

数据来源: Taylor

ISSN:0022-1945    

DOI:10.1080/09291018709359941

出版商:Taylor & Francis Group    

年代:1987

数据来源: Taylor