Annual rhythm of growth intensity of microalgal culture Dunaliella viridis Teod. (Chlorophyta) and fluctuations of some heliophysical factors

2008 ◽  
Vol 10 (4) ◽  
pp. 350-364 ◽  
Author(s):  
A. I. Bozhkov ◽  
N. G. Menzyanova ◽  
M. K. Kovalyova
Keyword(s):  
Dunaliella Viridis ◽  
Annual Rhythm ◽  
Growth Intensity ◽  
Microalgal Culture

scholarly journals Chromochloris zofingiensis (Chlorophyceae) Divides by Consecutive Multiple Fission Cell-Cycle under Batch and Continuous Cultivation

Biology ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 157
Author(s):  
Idan Koren ◽  
Sammy Boussiba ◽  
Inna Khozin-Goldberg ◽  
Aliza Zarka
Keyword(s):  
Cell Cycle ◽  
Continuous Culture ◽  
Continuous Cultivation ◽  
High Light ◽  
Nuclear Transformation ◽  
Storage Lipids ◽  
Microalgal Culture ◽  
Multiple Fission ◽  
Cell Release ◽  
Chromochloris Zofingiensis

Several green algae can divide by multiple fission and spontaneously synchronize their cell cycle with the available light regime. The yields that can be obtained from a microalgal culture are directly affected by cell cycle events. Chromochloris zofingiensis is considered as one of the most promising microalgae for biotechnological applications due to its fast growth and the flexible trophic capabilities. It is intensively investigated in the context of bio-commodities production (carotenoids, storage lipids); however, the pattern of cell-cycle events under common cultivation strategies was not yet characterized for C. zofingiensis. In this study, we have employed fluorescence microscopy to characterize the basic cell-cycle dynamics under batch and continuous modes of phototrophic C. zofingiensis cultivation. Staining with SYBR green—applied in DMSO solution—enabled, for the first time, the clear and simple visualization of polynuclear stages in this microalga. Accordingly, we concluded that C. zofingiensis divides by a consecutive pattern of multiple fission, whereby it spontaneously synchronizes growth and cell division according to the available illumination regime. In high-light continuous culture or low-light batch culture, C. zofingiensis cell-cycle was completed within several light-dark (L/D) cycles (14 h/10 h); however, cell divisions were synchronized with the dark periods only in the high-light continuous culture. In both modes of cultivation, daughter cell release was mainly facilitated by division of 8 and 16-polynuclear cells. The results of this study are of both fundamental and applied science significance and are also important for the development of an efficient nuclear transformation system for C. zofingiensis.

Annual changes in 6-sulphatoxymelatonin excretion in man

1988 ◽  
Vol 117 (4) ◽  
pp. 470-476 ◽  
Author(s):  
Christopher J. Bojkowski ◽  
Josephine Arendt
Keyword(s):  
Intermediate Phase ◽  
Urine Samples ◽  
Plasma Samples ◽  
Annual Change ◽  
Melatonin Secretion ◽  
Normal Volunteers ◽  
Plasma Melatonin ◽  
Annual Rhythm ◽  
Major Urinary Metabolite ◽  
Annual Changes

Abstract: A recently developed RIA for 6-sulphatoxymelatonin, the major urinary metabolite of melatonin, has been used to investigate the annual change in melatonin secretion in humans. Twenty plasma samples were taken from 18 volunteers throughout a 24-h period and simultaneous 6-hourly urine samples were also collected. Plasma melatonin and urinary 6-sulphatoxymelatonin were measured by RIA. 6-Sulphatoxymelatonin assayed in the urine samples was shown to be a good index of the rhythmic characteristics of the plasma melatonin secretion. To study annual changes in excretion four sequential 6-hourly urine samples were collected at monthly intervals from 16 normal volunteers for 13 months. Cosinor curves were fitted to the 6-sulphatoxymelatonin excretion data and the 24-h rhythm was described by the cosinor parameters: amplitude, mesor and acrophase. Significant differences in the acrophase were found during the year. The summer acrophase was phase advanced relative to the winter acrophase by about 1.5 h while intermediate phase positions were observed in spring/autumn. The 24-h excretion of urinary 6-sulphatoxymelatonin was remarkably consistent and there was no annual rhythm. In contrast, the daytime 6-sulphatoxymelatonin excretion between 12.00–18.00 h showed a statistically significant seasonal rhythm, with peaks in December/January and in July.

scholarly journals The early larval development of the tropical reef lobster Enoplometopus antillensis Lütken (Astacidea, Enoplometopidae) reared in the laboratory

2007 ◽  
Vol 24 (2) ◽  
pp. 382-396 ◽  
Author(s):  
Fernando A. Abrunhosa ◽  
Max W. P. Santana ◽  
Marcus A. B. Pires
Keyword(s):  
Larval Development ◽  
Water Tank ◽  
Dunaliella Viridis ◽  
Early Stages ◽  
Tropical Reef ◽  
Early Larval Development

The early stages of the tropical reef lobster Enoplometopus antillensis Lütken, 1865 were described and illustrated in detail from specimens reared in the laboratory. Ovigerous females were captured in their habitat, at a depth of about 15 meters and transported to the laboratory. The larvae were reared in a recirculation water tank for approximately 15 days and then transferred to four 10 liters aquariums. The larvae were fed on Artemia sp. nauplii. Microalgae Dunaliella viridis was added daily to the culture. The larvae moulted seven times progressing through the zoea VIII. Megalopa stage was not achieved. The intermoulting period of each stage averaged from eight to 12 days. Morphological comparisons with previous reports are briefly discussed.

scholarly journals Evaluation of Growth Intensity in Suffolk and Charollais Sheep

2018 ◽  
Vol 66 (1) ◽  
pp. 61-67 ◽  
Author(s):  
Tomáš Janoš ◽  
Radek Filipčík ◽  
Martin Hošek
Keyword(s):  
Birth Weight ◽  
Litter Size ◽  
Body Dimensions ◽  
Growth Intensity ◽  
Diagonal Length ◽  
Growth Ability

The aim of the study was to evaluate the influence of breed (Suffolk, Charollais), sex (ram, ewes) and litter size (singles, twins, triplets) on the growth ability of lambs from birth to 300 days of age. Insignificantly higher (p > 0.05) birth weight (4.47 ± 1.07 kg), weight in 30 days (13,87 ± 3.28 kg), 100 days (36.51 ± 5.80 kg) and 300 days (79.00 ± 13.64 kg) was found in the lambs of the Suffolk breed. Higher birth weight was also associated with larger body dimensions in the Suffolk breed (height at withers 42.43 cm, diagonal length of body 43.60 cm). In 100 days, the lambs of Charollais were slightly bigger, in 300 days the height at withers and the diagonal length of body were nearly the same in both breeds. Higher growth intensity was recorded in rams (DG0−300: Ram = 239.87 g. day−1, Ewe = 221.67 g. day−1). With regard to the litter size, higher growth intensity was found in singles (234.77 g. day-1) when compared to lambs from twins (226.10 g. day−1) or triplets (225.63 g. day−1).

Control of the annual rhythm of breeding in ewes: effect of an equatorial daylength with reversed thermal seasons

1967 ◽  
Vol 68 (1) ◽  
pp. 61-67 ◽  
Author(s):  
M. Wodzicka-Tomaszewska ◽  
J. C. D. Hutchinson ◽  
J. W. Bennett
Keyword(s):  
Annual Rhythm ◽  
Group 3 ◽  
Group 2 ◽  
Group 1

1. Three groups of seven Southdown and seven medium wool Peppin Merino ewes were subjected, respectively, to seasons of daylength corresponding to a latitude of 60° S., reversed seasonal lighting (60° N.) and an equatorial daylength with reversed thermal seasons, for 2½ years. During the next 20 months group 1 continued as before. Group 2 had a 32-week photoperiodic year and group 3 had a 32-week thermal year with equatorial daylength.

LINEAR GROWTH OF YOUNG KAZAKH FAT-TAILED ROUGH-HAIRED BREED OF SHEEP

2020 ◽  
pp. 25-28
Author(s):  
YU.A. YULDASHBAYEV ◽  
◽  
V.I. KOSILOV ◽  
E.A. NIKONOVA ◽  
T.S. KUBATBEKOV ◽  
...  
Keyword(s):  
Linear Growth ◽  
Body Parts ◽  
Trunk Length ◽  
Growth Intensity ◽  
Gender And Age ◽  
Chest Girth

The article presents the results of studying the linear growth of rams, boulders and eggs of a short-tailed rough-coated breed of sheep. The infl uence of gender and age on the studied indicators was studied. It was found that measurements of body parts that characterize the development of the chest, such as chest depth, chest width, chest girth behind the shoulder blades, were characterized by the highest growth intensity, and height measurements, as well as oblique trunk length and pastern girth, increased less intensively with age. The advantage in the intensity of growth of the analyzed examples was in the rams.

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