scholarly journals Moonlight cycles synchronize oyster behaviour

2019 ◽  
Vol 15 (1) ◽  
pp. 20180299 ◽  
Author(s):  
Laura Payton ◽  
Damien Tran
Keyword(s):  
Biological Rhythms ◽  
Temporal Organization ◽  
Biological Processes ◽  
Direct Response ◽  
Ecological Aspects ◽  
Endogenous Clock ◽  
External Cues ◽  
Valve Opening ◽  
Life On Earth ◽  
Activity Behaviour

Organisms possess endogenous clock mechanisms that are synchronized to external cues and orchestrate biological rhythms. Internal timing confers the advantage of being able to anticipate environmental cycles inherent in life on Earth and to prepare accordingly. Moonlight-entrained rhythms are poorly described, being much less investigated than circadian and circannual rhythms synchronized by sunlight. Yet focus on these lunar rhythms is highly relevant to understanding temporal organization of biological processes. Here, we investigate moonlight cycle effects on valve activity behaviour of the oyster Crassostrea gigas . Our results show that oysters modulate valve behaviour according to both intensity and direction of the lunar illumination cycle. As a consequence, valve opening amplitude is significantly increased at third quarter Moons (decreasing lunar illumination) compared with first quarter Moons (increasing lunar illumination) despite identical lunar illumination, and this indicates that oyster modulation of valve behaviour by moonlight cycles is not a direct response to lunar illumination. We propose that oysters use moonlight cycles to synchronize behaviour and also other physiological and ecological aspects of this benthic mollusc bivalve.

Systematic approaches in water management: Aquatic outlook and decision support systems combining monitoring, research, policy analysis and information technology

1996 ◽  
Vol 34 (12) ◽  
pp. 9-16 ◽  
Author(s):  
J. de Jong ◽  
J. T. van Buuren ◽  
J. P. A. Luiten
Keyword(s):  
Water Management ◽  
Policy Analysis ◽  
Research Policy ◽  
Human Life ◽  
Management Policy ◽  
Ecological Aspects ◽  
Management Plans ◽  
Water Management Plans ◽  
Life On Earth

Sustained developments is the target of almost every modern water management policy. Sustainability is focused on human life and on the ecological quality of our environment. Both aspects are essential for life on earth. Within a river catchment area this means that well balanced relations have to be laid between human activities and ecological aspects in the involved areas. Policy analysis is especially looking for the most efficient way to analyse and to overcome bottlenecks. In The Netherlands project “The Aquatic Outlook” all these elements are worked out in a nationwide scale, providing the scientific base and policy analysis from which future water management plans can be derived.

scholarly journals Desynchronization of biological rhythms in response to environmental factors

2017 ◽  
Vol 95 (6) ◽  
pp. 502-512
Author(s):  
F. I. Komarov ◽  
S. I. Rapoport ◽  
Tamara K. Breus ◽  
S. M. Chibisov
Keyword(s):  
Circadian Rhythm ◽  
Environmental Factors ◽  
Temporal Structure ◽  
Biological Rhythms ◽  
Biological Processes ◽  
Structure And Dynamics ◽  
Causative Factors ◽  
Temperature Rhythms ◽  
Rotation Of The Earth ◽  
Circadian Rhythm Disorders

The temporal structure and dynamics of biological rhythms were formed in the course of evolution under the influence of environmental factors. Circadian rhythm as a central one in biological objects developed in response to daily luminosity and temperature rhythms related to rotation of the Earth. New causative factors that could be involved in this process and affect the entire spectrum of biological rhythms emerged with the advent of space research. The discovery of solar wind, interplanetary magnetic field, and Earth’s magnetosphere revealed similar periodicity of biological rhythms and magnetic factors which suggests possible participation of the latter in the formation of the former. Disturbances in magnetic rhythms may lead to desynchronization of biological processes by the adaptive stress mechanism as exemplified by circadian rhythm disorders in response to jetlag. This hypothesis forwarded by the authors in the 1990s was confirmed by further investigations including those reported by foreign researchers.

The neuronal network of the endogenous clock

e-Neuroforum ◽  
2010 ◽  
Vol 16 (1) ◽  
Author(s):  
Charlotte Förster
Keyword(s):  
Molecular Basis ◽  
Clock Genes ◽  
Fruit Fly ◽  
Biological Processes ◽  
Rhythm Generation ◽  
The Metabolic Syndrome ◽  
Clock Network ◽  
Endogenous Clock ◽  
The Brain

AbstractEndogenous clocks control the rhythm of many biological processes. Malfunction of endogenous clocks in humans can lead to various diseases as sleep disorders, depres­sions, the metabolic syndrome and cancer. All animals have a main clock in the brain. This clock comprises a network of clock neurons that communicate with each other. In each clock neuron, conserved clock genes and pro­teins interact in to generate a molecular os­cillation. The molecular basis of this rhythm generation as well as the anatomy of the neuronal clock network is best investigated in the fruit fly Drosophila melanogaster. In the little fly, clock genes can be shut down in specific clock neurons. Furthermore, specific clock neurons can be electrically silenced and the rhythmic behaviour of such manipulated flies can be studied. A flurry of recent studies has begun to identify the role of specific clock neurons in the clock network, and these find­ings are helping to understand the basic neu­ronal mechanisms of endogenous clocks.

scholarly journals Chronobiology and the design of marine biology experiments

2018 ◽  
Vol 76 (1) ◽  
pp. 60-65 ◽  
Author(s):  
Audrey M Mat
Keyword(s):  
Marine Biology ◽  
Clock Genes ◽  
Biological Rhythms ◽  
Marine Species ◽  
Temporal Organization ◽  
Biological Clocks ◽  
Solar Cycles ◽  
Dark Cycle ◽  
Marine Habitats ◽  
Selection Of

AbstractMarine habitats are shaped by several geophysical cycles ranging from a few hours (tidal and solar cycles) to a year (seasons). These cycles have favoured the selection of endogenous biological clocks. Such a clock is a molecular time-keeping mechanism that consists of a set of core clock genes whose expression oscillates. The clocks produce biological rhythms and influence virtually all metabolic, physiological, and behavioural functions in organisms. This work highlights the importance to take chronobiology into account in experimental marine biology to avoid faulty results, misinterpretation of results, and/or to strengthen observations and conclusion. A literature survey, based on 150 articles, was conducted and showed that, despite the pervasive imprint of biological rhythms in marine species, environmental cycles such as the 24 h-light/dark cycle and the seasonality are rarely considered in experimental designs. This work emphasizes that better integrating the temporal organization and regulation of marine species within the marine biology community is essential for obtaining representative results.

Sleep and its Interaction with Endocrine Rhythms

1983 ◽  
Vol 142 (3) ◽  
pp. 215-219 ◽  
Author(s):  
Paul E. Mullen
Keyword(s):  
Biological Rhythms ◽  
Biological Processes ◽  
Close Approximation ◽  
Important Group ◽  
Internal Oscillator ◽  
Free Running ◽  
The Individual

Rhythmic variations with frequences from fractions of seconds to years characterise a wide variety of biological processes (Aschoff, 1979). Biological rhythms can be observed, not only in the individual of the species, but also in the cells which comprise the organism and the populations of which it is a member. These regular fluctuations can be endogenously generated by some form of internal oscillator, or alternatively may passively reflect exogenous environmental alterations. An important group of rhythms combines both endogenous and exogenous inputs with an internal oscillator or oscillators which are capable of being influenced by some external change. In this situation, the internal rhythm is kept in harmony with an environmental cycle by a change in the outside world acting as a synchroniser or zeitgeber. In this type if the animal is artificially isolated from its normal external synchroniser, the rhythm will continue, but free running, with a periodicity which is a close approximation to the duration of the environmental cycle to which it is normally tied. These rhythms normally synchronised to an environmental cycle but capable of being self-sustaining at approximately the same rate, are termed circa rhythms: thus circadian, circannual and circalunar rhythms, according to the geophysical cycle by which they are normally entrained.

scholarly journals High performance intensiometric direct- and inverse-response genetically encoded biosensors for citrate

2020 ◽  
Author(s):  
Yufeng Zhao ◽  
Yi Shen ◽  
Yurong Wen ◽  
Robert E. Campbell
Keyword(s):  
Conformational Changes ◽  
Mammalian Cells ◽  
High Performance ◽  
Catalytic Domain ◽  
Quantitative Imaging ◽  
Live Cells ◽  
Biological Processes ◽  
Direct Response ◽  
Qualitative And Quantitative ◽  
Inverse Response

AbstractMotivated by the growing recognition of citrate as a central metabolite in a variety of biological processes associated with healthy and diseased cellular states, we have developed a series of high-performance genetically encoded citrate biosensors suitable for imaging of citrate concentrations in mammalian cells. The design of these biosensors was guided by structural studies of the citrate-responsive sensor histidine kinase, and took advantage of the same conformational changes proposed to propagate from the binding domain to the catalytic domain. Following extensive engineering based on a combination of structure guided mutagenesis and directed evolution, we produced an inverse-response biosensor (ΔF/Fmin ~ 18) designated Citroff1 and a direct-response biosensor (ΔF/Fmin ~ 9) designated Citron1. We report the x-ray crystal structure of Citron1 and demonstrate the utility of both biosensors for qualitative and quantitative imaging of steady-state and pharmacologically-perturbed citrate concentrations in live cells.

scholarly journals Cosmic Dust May Be Key Source of Phosphorus for Life on Earth

Eos ◽  
2021 ◽  
Vol 102 ◽  
Author(s):  
Sarah Stanley
Keyword(s):  
Chemical Reactions ◽  
Cosmic Dust ◽  
Biological Processes ◽  
Earth’S Atmosphere ◽  
Phosphorus Containing ◽  
Earth's Atmosphere ◽  
Life On Earth

When tiny particles enter Earth’s atmosphere, a newly described series of chemical reactions may lead to production of phosphorus-containing molecules that are essential for biological processes.

scholarly journals Stability in chemistry and biology: Life as a kinetic state of matter

2005 ◽  
Vol 77 (11) ◽  
pp. 1905-1921 ◽  
Author(s):  
Addy Pross
Keyword(s):  
Natural Selection ◽  
Physicochemical Process ◽  
Kinetic Stability ◽  
Living Systems ◽  
Biological Processes ◽  
Dynamic Kinetic Stability ◽  
The World ◽  
Far From Equilibrium ◽  
State Of Matter ◽  
Life On Earth

Despite the considerable advances in our understanding of biological processes, the physicochemical relationship between living and nonliving systems remains uncertain and a continuing source of controversy. In this review, we describe a kinetic model based on the concept of dynamic kinetic stability that attempts to incorporate living systems within a conventional physicochemical framework. Its essence: all replicating systems, both animate and inanimate, represent elements of a replicator space. However, in contrast to the world of nonreplicating systems (all inanimate), where selection is fundamentally thermodynamic, selection within replicator space is effectively kinetic. As a consequence, the nature of stability within the two spaces is of a distinctly different kind, which, in turn, leads to different physicochemical patterns of aggregation. Our kinetic approach suggests: (a) that all living systems may be thought of as manifesting a kinetic state of matter (as apposed to the traditional thermodynamic states associated with inanimate systems), and (b) that key Darwinian concepts, such as fitness and natural selection, are particular expressions of more fundamental physicochemical concepts, such as kinetic stability and kineticselection. The approach appears to provide an improved basis for understanding the physicochemical process of complexification by which life on earth emerged, as well as a means of relating life's defining characteristics - its extraordinary complexity, its far-from-equilibrium character, and its purposeful (teleonomic) nature - to the nature of that process of complexification.

Studies on the Physiology of Awareness: The Effect of Rhythmic Sensory Bombardment on Emotions, Blood Oxygen Saturation and the Levels of Consciousness

1952 ◽  
Vol 98 (413) ◽  
pp. 640-653 ◽  
Author(s):  
John W. Lovett Doust ◽  
Robert A. Schneider
Keyword(s):  
Biological Rhythms ◽  
Breath Holding ◽  
Biological Processes ◽  
Urinary Function ◽  
Blood Oxygen Saturation ◽  
Chemical Systems ◽  
Physiological Variables ◽  
Blood Ph ◽  
Spot Activity ◽  
The Individual

Biological rhythms exist in a rich variety and almost bewildering profusion to attend and equilibrate the physiology of man. Such dynamic phasic activity appears not only to be intimately concerned with the phenomenology of life and biological processes in general, but is also to be found in purely chemical systems (Hedges and Meyers, 1926). Modalities of the periodicities associated with life can be divided into those external to the organism—including diurnal and climatic variation, sun-spot activity, etc., and into those inherent within the individual such as the respiratory and cardiac rhythms, the menstrual cycle, sleep and awakening. Only less well marked are certain psychological periodicities such as “cyclothymic “variations in mood and personality. In the course of the present century much painstaking research has attempted to link external with internal rhythmic activities, significant correlations being adduced between seasonal variation and, for example, the incidence of psychiatric disorder (Huntington, 1915), immunity from disease (Spencer and Melroy, 1943, Webster, 1944), temperament and behaviour (Petersen, 1934-36; Mills, 1942), and an impressive array of biochemical and physiological variables ranging from blood pH, lactic acid and protein to breath-holding time, plethysmography, tests of hand strength and fatigability, dark adaptation time and various tests of urinary function (Petersen, 1947).

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