Studies in Diurnal Rhythms

1951 ◽  
Vol 28 (2) ◽  
pp. 165-172
Author(s):  
J. L. CLOUDSLEY-THOMPSON
Keyword(s):  
Diurnal Rhythm ◽  
Rhythmic Activity ◽  
Temperature Fluctuations ◽  
West African ◽  
Diurnal Rhythms ◽  
Locomotory Activity ◽  
Depressing Effect ◽  
African Species ◽  
Fluctuating Light ◽  
Effect Of Light

Visual experiments on two small British species of millipedes have demonstrated that the diurnal cycle of rhythmic activity as represented by the number of animals on the surface is primarily a response to light and darkness, but is also correlated with the stimulus of falling temperature in the evening. Aktograph experiments on two large West African species of millipedes have demonstrated an endogenous diurnal rhythm independent of fluctuating light and temperature, and persisting (in Ophistreptus) up to 19 days. Locomotory activity is stimulated both by increases and decreases of temperature; and it is probable that temperature fluctuations are of primary importance in the initiation of diurnal rhythms. The effect of light on activity is slight, but constant temperatures over long periods have, a depressing effect.

scholarly journals Some new West African species of Anopheles (sensu lato), with notes on nomenclature

1911 ◽  
Vol 2 (2) ◽  
pp. 141-143 ◽  
Author(s):  
F. W. Edwards
Keyword(s):  
New Species ◽  
Natural History ◽  
West Africa ◽  
West African ◽  
Tropical Medicine ◽  
London School ◽  
African Species ◽  
New West

In describing the following new species from West Africa, some words of explanation are needed as to the generic names used. In the first place, it is necessary to say that the writer follows Messrs. Dyar and Knab in considering that most of the genera into which Meigen's genus Anopheles has recently been split up are not genera in any accepted sense, and should sink under the old name Anopheles. Provisionally, however, Stethomyia, Chagasia, Calvertina and Bironella are considered as distinct; as none of these genera are African, this will not affect the present paper. Lieut.-Col. A. Alcock, of the London School of Tropical Medicine, has kindly allowed me to see the manuscript of a paper on the classification of Anopheles, which he is about to publish in the Annals and Magazine of Natural History, and I have been able to concur entirely with his views; he recognises only five sub-genera of Anopheles, the sub-genus Nyssorhynchus including all those species with flat scales on thorax and abdomen, i.e., the genera Nyssorhynchus, Cellia and Neocellia of Theobald's Monograph.

Sylvan katydids (Orthoptera: Tettigoniidae: Pseudophyllinae) of the Guinean Forests of West Africa hotspot: an overview and descriptions of new species

Zootaxa ◽  
2008 ◽  
Vol 1712 (1) ◽  
pp. 1
Author(s):  
PIOTR NASKRECKI
Keyword(s):  
New Species ◽  
West Africa ◽  
West African ◽  
The State ◽  
Published Data ◽  
The West ◽  
African Species ◽  
Forest Coverage

The state of knowledge on sylvan katydids (Tettigoniidae, Pseudophyllinae) of Guinean Forests of West Africa hotspot is discussed. Based on published data on their distribution, and the extent of the current forest coverage of the region it is possible that some of the West African species of the Pseudophyllinae may be threatened or even extinct. Five new species are described (Adapantus affluens sp. nov., A. angulatus sp. nov., A. pragerorurm sp. nov., Tomias gerriesmithae sp. nov., and Mormotus alonsae sp. nov.), and 4 species of West African Pseudophyllinae are redescribed.

Circadian Rhythms of Serum Thyrotrophin and Body Temperature in Euthyroid Individuals and their Responses to Warming

1984 ◽  
Vol 67 (4) ◽  
pp. 433-437 ◽  
Author(s):  
B. P. O'malley ◽  
A. Richardson ◽  
N. Cook ◽  
S. Swart ◽  
F. D. Rosenthal
Keyword(s):  
Body Temperature ◽  
Circadian Rhythms ◽  
Diurnal Rhythm ◽  
Normal Subjects ◽  
The Body ◽  
Diurnal Rhythms ◽  
Tsh Levels

1. The diurnal rhythms of body temperature and serum thyrotrophin (TSH) levels in euthyroid individuals behaved inversely to one another. 2. An artificially induced rise in the body temperature of these individuals was accompanied by a fall in serum thyrotrophin levels, the amplitudes of their respective rhythms decreasing simultaneously. 3. There was a marked correlation between the degrees of change in body temperature and circulating thyrotrophin levels respectively during warming. 4. In normal subjects manipulation of the diurnal rhythm of body temperature brings about inverse alterations in the thyrotrophin rhythm.

scholarly journals Impact of Diurnal Periodicity, Temperature, and Light on Sporulation of Bremia lactucae

2007 ◽  
Vol 97 (8) ◽  
pp. 979-986 ◽  
Author(s):  
Berit Nordskog ◽  
David M. Gadoury ◽  
Robert C. Seem ◽  
Arne Hermansen
Keyword(s):  
Light Quality ◽  
Suppressive Effect ◽  
Interactive Effects ◽  
Diurnal Rhythms ◽  
Controlled Environment ◽  
Diurnal Pattern ◽  
Bremia Lactucae ◽  
Forecasting Models ◽  
Long Day ◽  
Effect Of Light

We evaluated direct and interactive effects of light quality and intensity, temperature and light, diurnal rhythms, and timing of high relative humidity during long day lengths on sporulation of Bremia lactucae, the causal agent of lettuce downy mildew, using inoculated lettuce seedlings and detached cotyledons. Suppression of sporulation by light was strongly dependent upon temperature and there was little suppression at ≤10°C. The most suppressive waveband was in the range from 400 to 450 nm, although a lesser effect of wavebands from 450 to 500 and 500 to 550 nm could be detected. At 15°C, near the lower threshold for suppression of sporulation by light, a clear diurnal pattern of sporulation was observed independent of light and darkness. This diurnal rhythm potentially could interact with light and temperature to confound the results of controlled environment studies, and may be the controlling factor in timing of sporulation at low temperatures. Forecasting models that currently use sunrise and sunset to delimit periods conducive to sporulation can be adapted to short nights and extended twilight conditions by incorporating the effects reported herein. Additionally, models of sporulation could be adapted to better reflect a decrease or absence of the suppressive effect of light at <15°C.

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