scholarly journals Entrainment of Arabidopsis roots to the light:dark cycle by light piping

2018 ◽  
Vol 41 (8) ◽  
pp. 1742-1748 ◽  
Author(s):  
Hugh G. Nimmo
Keyword(s):  
Light:Dark Cycle

scholarly journals Effects of nutrients, salinity, pH and light:dark cycle on the production of reactive oxygen species in the alga Chattonella marina

2007 ◽  
Vol 346 (1-2) ◽  
pp. 76-86 ◽  
Author(s):  
Wenhua Liu ◽  
Doris W.T. Au ◽  
Donald M. Anderson ◽  
Paul K.S. Lam ◽  
Rudolf S.S. Wu
Keyword(s):  
Reactive Oxygen Species ◽  
Reactive Oxygen ◽  
Oxygen Species ◽  
Chattonella Marina ◽  
Light:Dark Cycle

The effect of food related cues on the specificity of appetite in the rat

1998 ◽  
Vol 1998 ◽  
pp. 29-29
Author(s):  
J. E. L. Day ◽  
P. J. Rogers ◽  
G. M. Finch ◽  
E. A. Gaffan
Keyword(s):  
Diet Selection ◽  
Light Phase ◽  
General Increase ◽  
Feeding Motivation ◽  
Effect Of Food ◽  
Experimental Subjects ◽  
Standard Laboratory Diet ◽  
Feeding Bout ◽  
Light:Dark Cycle ◽  
Specific Food

It is known that if rats learn that a cue reliably precedes eating, its presentation can cause them to initiate a feeding bout when they are apparently sated (Weingarten, 1983, 1985). However, it is currently unclear precisely how such conditioned cues affect appetite. For example, does this type of conditioning elicit food specific appetites or do individuals merely experience a general increase in feeding motivation (Mela & Rogers, 1998)? To address this issue, the present experiment investigated the hypothesis that exposure to a cue (conditioned stimulus: CS) previously paired with a specific food biases diet selection in favour of that food when an individual is given a choice. The objective of the experiment was to enhance our understanding of the behavioural control of feeding, and hence our ability to predict diet selection and food intake.The experimental subjects were 12 male Lister-hooded rats (initial body-weight 233; SD=20g). Throughout the experiment the subjects were maintained on a 1lh:13h light:dark cycle with lights on at 0700h, and had ad libitum access to a standard laboratory diet during the light phase.

Melatonin and corticosterone regulation: Feeding time or the light:Dark cycle?

Life Sciences ◽  
1979 ◽  
Vol 25 (21) ◽  
pp. 1837-1842 ◽  
Author(s):  
William R. Holloway ◽  
Hing W. Tsui ◽  
Lee J. Grota ◽  
Gregory M. Brown
Keyword(s):  
Feeding Time ◽  
Light:Dark Cycle

scholarly journals Effect of Reoxygenation on the Electrical Stability of the Rat Heart In Vivo: A Chronobiological Study

2013 ◽  
pp. S143-S149
Author(s):  
P. ŠVORC ◽  
A. MAROSSY ◽  
P. ŠVORC ◽  
M. BUŽGA
Keyword(s):  
Body Weight ◽  
Tidal Volume ◽  
Rat Heart ◽  
Ventricular Arrhythmias ◽  
Wistar Rats ◽  
Pulmonary Ventilation ◽  
Electrical Stability ◽  
Female Wistar Rats ◽  
Light:Dark Cycle

Reoxygenation following hypoxic episodes can increase the risk for the development of ventricular arrhythmias, which, in addition to circadian aspects of reoxygenation arrhythmias has not been studied extensively. The aim of the present study was to evaluate circadian changes in the electrical stability of the rat heart during reoxygenation following a hypoventilatory episode. The electrical stability of the heart, defined in the present study as the ventricular arrhythmia threshold (VAT), was measured at 3 h intervals at clock times 09:00, 12:00, 15:00, 18:00, 21:00, 24:00, 03:00, 06:00 and 09:00 during 20 min hypoventilation (20 breaths/min, tidal volume = 0.5 ml/100 g body weight [n=17]) and subsequent 20 min reoxygenation (50 breaths/min, tidal volume = 1 ml/100 g body weight [n=4]) intervals. The experiments were performed using pentobarbital-anesthetized (40 mg/kg intraperitoneally) female Wistar rats that first underwent a four-week adaptation to a 12 h light:12 h dark regimen. Detailed analysis showed that circadian VATs changed to biphasic rhythms at 10 min of hypoventilation. The VAT circadian rhythms were observed immediately following the commencement of reoxygenation, with the highest values measured between 12:00 and 15:00, and the lowest values between 24:00 and 03:00. These results suggest that myocardial vulnerability is dependent on the light:dark cycle and characteristics of pulmonary ventilation.

Plastid Development in Leaf Epidermis

1981 ◽  
Vol 39 ◽  
pp. 618-619
Author(s):  
Jacob P. Varkey ◽  
Mathew J. Nadakavukaren
Keyword(s):  
Leaf Development ◽  
Osmium Tetroxide ◽  
Leaf Epidermis ◽  
Plastid Development ◽  
Mesophyll Cells ◽  
Plastid Ultrastructure ◽  
Epidermal Tissue ◽  
Standard Procedures ◽  
Growth Chambers ◽  
Light:Dark Cycle

Changes in the plastid ultrastructure during development of a leaf have been studied extensively. Most studies have been done on the development of chloroplasts in mesophyll cells. Chloroplasts are small and few in number or plastids never develop into chloroplasts in epidermal cells of leaves of many species. Not much is known about the development of plastids in the epidermal tissue. Sunflower was selected to study the plastid development in the epidermal tissue.Sunflower plants were grown from seeds in growth chambers maintained on a 14:10 light:dark cycle at a daytime temperature of 78 F and nighttime temperature of 70 F with 80% humidity. Samples for ultrastructural study were taken from primary leaves at different stages of development. Because the rate of leaf development can vary from plant to plant, samples were taken from the same primary leaves of selected seedlings. These samples fixed in glutaraldehyde followed by osmium tetroxide were processed for electron microscopy using standard procedures.

N-acetyltransferase activity and indole contents of the male syrian hamster harderian gland: Changes during the light:dark cycle

1989 ◽  
Vol 268 (1) ◽  
pp. 20-25 ◽  
Author(s):  
Armando Menendez-Pelaez ◽  
Russel J. Reiter ◽  
Aldo Gonzalez-Brito ◽  
Kimberly A. Howes
Keyword(s):  
Syrian Hamster ◽  
Harderian Gland ◽  
Acetyltransferase Activity ◽  
Light:Dark Cycle

scholarly journals Effect of temperature changes on the cercarial-shedding rate of two trematodes

2016 ◽  
Vol 106 (0) ◽  
Author(s):  
Cecilia L. Achiorno ◽  
Sergio R. Martorelli
Keyword(s):  
Effect Of Temperature ◽  
Optimum Temperature ◽  
Significance Level ◽  
Temperature Changes ◽  
Significant Difference ◽  
Light:Dark Cycle ◽  
Cercarial Emergence

ABSTRACT Since temperature is a key condition in the initiation of cercarial emergence, the objective of the work reported here was to evaluate the effect of that variable on the shedding of two morphologic and taxonomic types of cercariae. Bioassays were accordingly performed with snails naturally infected with either monostome or pleurolophocercous cercariae because those two cercarial types were found to be the most prevalent in the environment under study. The snails were placed in 6-ml circular plastic dishes with soft plastic stoppers containing 3 ml of reconstituted water and then sequentially exposed for 24 h to a 14:10-h light:dark cycle at 20, 25, or 30 °C. The data were analyzed at a significance level of p <0.05 by means of the InfoStat program. The optimum temperature for cercarial emergence was typically in the range of 25 °C and decreased significantly at 30 °C. We observed no significant difference in the number of cercariae emerging between the two morphologic types.

scholarly journals 0019 Investigating Novel-Sleep Related Genes in Drosophila Melanogaster: A Follow Up on KOMP2 Identified Genes in Mus Musculus

SLEEP ◽  
2020 ◽  
Vol 43 (Supplement_1) ◽  
pp. A8-A8
Author(s):  
R Guerriero ◽  
P Shaw ◽  
B O’Hara
Keyword(s):  
Drosophila Melanogaster ◽  
Mus Musculus ◽  
Single Gene ◽  
Homologous Proteins ◽  
Activity Data ◽  
Non Invasive ◽  
Movement Data ◽  
Underlying Mechanisms ◽  
Function Of Sleep ◽  
Light:Dark Cycle

Abstract Introduction Sleep is well-conserved across phylogeny, yet the function of sleep and its underlying mechanisms are currently poorly understood. Novel-sleep related genes were previously identified by our lab in part of the Knockout Mouse Phenotyping Program (KOMP2). This international effort generated single-gene knockouts on a Mus musculus C57BL6/NJ background and proceeded to gather data on over 200 phenotypes, including five days of baseline sleep and wake parameters. Sleep data was gathered using the non-invasive, high-throughput PiezoSleep System (Signal Solutions, LLC) which uses a piezoelectric film to gather movement data which then can be assigned to be wake or sleep. These data identified 122 novel genes that influence sleep phenotypes such as sleep duration and bout length. Methods Homologous proteins were identified and a subset of these genes are under investigation in Drosophila melanogaster, including myosin heavy chain (Mhc) and spinophillin (Spn). Using both genetic mutants and RNAi knockdowns, the effect of gene reduction on activity profiles and sleep are being analyzed. Sleep and activity data is recorded using DAM2 monitors (TriKinetics Inc.) while being maintained on a 12:12 light:dark cycle. Results Preliminary data analysis show that aberrations in Mhc and Spn impact sleep percentage. Both Mhc and Spn are known to be involved in structure and development of synapses. Spn is involved in the neurexin scaffolding of presynaptic neurons and also help with maintaining these synapses once formed. Synaptic reorganization and regulation is known to take place during sleep, showing a potential connection of these proteins and sleep. Conclusion These genes that show effects on sleep in both D. melanogaster and M. musculus show a conservation of the underlying sleep machinery. Support  

The location of floral nectar sources by mosquitoes: an advanced bioassay for volatile plant odours and initial studies with Aedes aegypti (L.) (Diptera: Culicidae)

1988 ◽  
Vol 78 (4) ◽  
pp. 641-650 ◽  
Author(s):  
P. C. Jepson ◽  
T. P. Healy
Keyword(s):  
Aedes Aegypti ◽  
Feeding Behaviour ◽  
Floral Nectar ◽  
Behavioural Activity ◽  
Nectar Feeding ◽  
Nectar Sources ◽  
Nectar Source ◽  
Plant Odours ◽  
Ray Florets ◽  
Light:Dark Cycle

AbstractThe development and testing of a bioassay system to evaluate the potency of floral odours as mediators of long-range floral nectar source location by mosquitoes are described. The bioassay is quantitative and behaviourally discriminating, upwind flying and landing acting as indices of behavioural activity over the 24-h light:dark cycle. In initial tests, the responses of Aedes aegypti (L.) to the flowers and floral odours of ox-eye daisy (Leucanthemum vulgare) were investigated. A. aegypti exhibited a biphasic diel cycle of nectar-feeding behaviour and landed on modified flowers that retained either their disc or ray florets. Most significantly, the mosquitoes responded in a similar way to the odour of L. vulgare in the absence of visual stimuli or nutritional cues. They did not respond to solvent extracts of ox-eye daisy flowers.

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