Mating behaviour and light conditions cause seasonal changes in the dispersal pattern of the satyrine butterfly Lethe diana

2002 ◽  
Vol 27 (1) ◽  
pp. 33-40 ◽  
Author(s):  
Jun-Ya Ide
Keyword(s):  
Seasonal Changes ◽  
Mating Behaviour ◽  
Light Conditions ◽  
Dispersal Pattern

scholarly journals Light conditions alter accumulation of long chain polyprenols in leaves of trees and shrubs throughout the vegetation season.

2005 ◽  
Vol 52 (1) ◽  
pp. 233-241 ◽  
Author(s):  
Agnieszka Bajda ◽  
Tadeusz Chojnacki ◽  
Józefina Hertel ◽  
Ewa Swiezewska ◽  
Jacek Wójcik ◽  
...  
Keyword(s):  
Light Intensity ◽  
Seasonal Changes ◽  
Leaf Blade ◽  
Early Summer ◽  
Light Conditions ◽  
Natural Habitats ◽  
Vegetation Season ◽  
The Difference ◽  
Trees And Shrubs ◽  
Long Chain

In many plants belonging to angiosperms and gymnosperms the accumulation in leaves of long chain polyprenols and polyprenyl esters during growth in natural habitats depends on the light intensity. The amount of polyprenols in leaves is also positively correlated with the thickness of the leaf blade (SLA, specific leaf area). The polyprenol content of leaves shows seasonal changes with a maximum in autumn and a minimum in early summer with the difference between poorly and well illuminated plants persisting throughout the vegetation season.

scholarly journals Photoperiod-Induced Neuroplasticity in the Circadian System

2018 ◽  
Vol 2018 ◽  
pp. 1-13 ◽  
Author(s):  
Alessandra Porcu ◽  
Malini Riddle ◽  
Davide Dulcis ◽  
David K. Welsh
Keyword(s):  
Seasonal Changes ◽  
Phase Distribution ◽  
Light Exposure ◽  
Brain Regions ◽  
Day Length ◽  
Light Conditions ◽  
Seasonal Adaptation ◽  
Circadian Oscillators ◽  
Plastic Changes ◽  
Mood And Cognition

Seasonal changes in light exposure have profound effects on behavioral and physiological functions in many species, including effects on mood and cognitive function in humans. The mammalian brain’s master circadian clock, the suprachiasmatic nucleus (SCN), transmits information about external light conditions to other brain regions, including some implicated in mood and cognition. Although the detailed mechanisms are not yet known, the SCN undergoes highly plastic changes at the cellular and network levels under different light conditions. We therefore propose that the SCN may be an essential mediator of the effects of seasonal changes of day length on mental health. In this review, we explore various forms of neuroplasticity that occur in the SCN and other brain regions to facilitate seasonal adaptation, particularly altered phase distribution of cellular circadian oscillators in the SCN and changes in hypothalamic neurotransmitter expression.

scholarly journals Seasonal changes in the nutritional status and yielding of Anthurium cultorum Birdsey. Part II. Microelements

2009 ◽  
Vol 21 (2) ◽  
pp. 3-12 ◽  
Author(s):  
Tomasz Kleiber ◽  
Andrzej Komosa ◽  
Jolanta Krzyszkowska ◽  
Krzysztof Moliński
Keyword(s):  
Nutritional Status ◽  
Seasonal Changes ◽  
Plant Nutrition ◽  
Copper Content ◽  
Winter Period ◽  
Light Conditions ◽  
Summer Period ◽  
Simultaneous Decrease ◽  
The Given

Abstract The experiment was carried out in the years 2002-2004. Its aim was the determination of the tendencies in the microelement nutritional status of the standard cultivars of Anthurium cultorum Birdsey (‘Baron’, ‘Choco’, ‘Midori’, ‘Pistache’, ‘President’, ‘Tropical’ from Anthura B.V.) in the autumn-winter and spring-summer vegetation periods. The plants were cultivated in expanded clay using a drop fertigation system with standard nutrition. A significant influence of the vegetation periods and the light conditions associated with them was found to be exerted on the microelement plant nutrition. In the autumn-winter period, characterized by light deficit, the plant age significantly modified the nutrition (increase or decrease of content with a plant’s aging) with regard to zinc (-23.7%), copper (-25.8%) and boron (+25%), while in the spring-summer period, iron (+12.9%) and copper (-21.7%) nutrition was modified. During the three years of the study, the autumnwinter period showed a significant increase of iron content (+9.8%) with a simultaneous decrease of copper content (-6.5%), in comparison with the springsummer period. The awareness of the cyclical nature of the changes in the nutritional status of plants, depending on the given vegetation season, supplies a valuable instrument in the interpretation of plant analyses for diagnostic purposes.

scholarly journals Seasonal changes of photoperiodic response and inflorescence quality in pot cultivars of Chrysanthemum × grandiflorum grown in greenhouse

2012 ◽  
Vol 64 (4) ◽  
pp. 85-90 ◽  
Author(s):  
Marek Jerzy ◽  
Włodzimierz Breś
Keyword(s):  
Seasonal Changes ◽  
Photoperiodic Response ◽  
Climatic Conditions ◽  
Light Conditions ◽  
Cool Time ◽  
Photoperiodic Responses ◽  
Supplementary Lighting ◽  
The Moment ◽  
Very High

The aim of the research was to investigate seasonal changes of photoperiodic response and inflorescence quality in chrysanthemum from the Time group grown all year round without supplementary lighting. Four chrysanthemum cultivars were grown in 12 cycles starting on the second day of each successive month. The first cycle began on 2 January. From the moment of potting, the plants were treated with a short day. In periods of naturally long days, the day was shortened to 10.5 hours through shading. No supplementary illumination was used from November to mid-February (a photoperiod of under 10 hours) to improve light conditions in the period of insolation deficit. In Polish climatic conditions, the shortest photoperiodic responses were recorded usually in the cycles starting in February or March and August or September. An exceptionally longer photoperiodic response was recorded in the cycle including the height of summer, i.e. planting from June to July, when the temperature during the day was very high, and from October to December i.e. in the period of substantial insolation deficit. The highest quality of flower heads was attained by plants potted mostly between 2 March and 2 September and flowering from April - May to November. Those plants developed the greatest number of inflorescences and usually a typical, cultivar-specific colour of the flower. Chrysanthemums potted from 2 June to 2 July, i.e. in the period of the greatest heat, produced inflorescences with the smallest diameter. For the cultivar 'Cool Time', this unfavorable period lasted from 2 April to 2 August.

Seasonal variation in periodicity of mating behaviour in the rice stem borer, Chilo suppressalis (Walker) (Lepidoptera: Pyralidae)

1981 ◽  
Vol 71 (4) ◽  
pp. 631-637 ◽  
Author(s):  
H. Kanno
Keyword(s):  
Seasonal Variation ◽  
Sex Pheromone ◽  
Seasonal Changes ◽  
Mating Behaviour ◽  
Stem Borer ◽  
Pheromone Trap ◽  
Chilo Suppressalis ◽  
Rice Stem Borer ◽  
Lepidoptera Pyralidae ◽  
The Times

AbstractSeasonal variation in the circadian periodicity of mating behaviour in Chilo suppressalis (Wlk.) was investigated. In the field, mating was initiated at dusk in June, but not until after dark in August. The times of females calling and of male catches in a pheromone trap were later in August than in June. The seasonal variation in time of male catches coincided approximately with that of mating, suggesting that latter may be attributable in part to seasonal changes in the response of males to the sex pheromone. Also, it is likely that these variations are affected by environmental factors, especially temperature.

Seasonal changes in the plasma testosterone profile in Merino rams

1983 ◽  
Vol 23 (122) ◽  
pp. 254 ◽  
Author(s):  
MJ D'Occhio ◽  
DE Brooks
Keyword(s):  
Seasonal Changes ◽  
Mating Behaviour ◽  
Point Of View ◽  
Plasma Testosterone ◽  
Seasonal Trends ◽  
Testosterone Levels ◽  
Testosterone Secretion

The pattern of testosterone secretion (i.e. profile of plasma testosterone sampled every hour for 24 h) was characterized for Merino rams at various times during the year at latitude 35�S to assess seasonal trends. The profiles of plasma testosterone were always characterized by random peaks regardless of season. However, at any particular time of the year, there were large differences between individual rams in the number of peaks124 h (range 1-7). Mean plasma testosterone levels were higher and a greater number of peaks were recorded per 24 h in summer (December-January) than in winter (July) and spring (September-October). Seasonal changes observed in the plasma testosterone profile of Merino rams were consistent with the concept that activity of the hypothalamic-pituitary-gonadal axis in sheep is entrained to changes in the photoperiod. Merino rams at latitude 35�S are therefore markedly seasonal from an endocrine point of view, although they are not generally regarded as seasonal breeders based on mating behaviour.

Spreading the Word: Seasonal Changes Mean New Opportunities for Media Coverage

ASHA Leader ◽  
2013 ◽  
Vol 18 (7) ◽  
Keyword(s):  
Media Coverage ◽  
Seasonal Changes ◽  
Swimming Pools

Summer kicking into high gear conjures images of swimming pools and barbeques. But before you book your beach house for the weekend, think about what the changing seasons can mean for you professionally.

Seasonal changes in a ultraviolet structural colour signal in blue tits, Parus caeruleus

2002 ◽  
Vol 76 (2) ◽  
pp. 237-245 ◽  
Author(s):  
JONAS ORNBORG ◽  
STAFFAN ANDERSSON ◽  
SIMON C. GRIFFITH ◽  
BEN C. SHELDON
Keyword(s):  
Seasonal Changes ◽  
Parus Caeruleus ◽  
Structural Colour ◽  
Blue Tits ◽  
Colour Signal
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