scholarly journals Influences of Temperature on Development and Survival, Reproduction and Growth of a Calanoid Copepod (Pseudodiaptomus dubia)

2009 ◽  
Vol 9 ◽  
pp. 866-879 ◽  
Author(s):  
Changling Li ◽  
Xiaoxia Luo ◽  
Xianghu Huang ◽  
Binhe Gu
Keyword(s):  
Growth Rate ◽  
Water Temperature ◽  
Larval Development ◽  
Calanoid Copepod ◽  
Southern China ◽  
Larval Survival ◽  
Population Doubling ◽  
Population Doubling Time ◽  
Reproduction Rate ◽  
Egg Hatching

Pseudodiaptomus dubiais a calanoid copepod that is distributed widely in the estuarine-coastal waters of Asia and is a dominant copepod in the shrimp grow-out ponds in southern China. A laboratory culture experiment was conducted to evaluate the influences of water temperature on larval development, survival, and reproduction. Results indicate that within a temperature range from 15 to 35°C, larval development increases as the temperature increases. The water temperature for optimal larval survival rate ranges from 20 to 35°C. Longevity and egg hatching time decrease as the temperature increases from 20 to 35°C. Total fecundity and reproduction frequency increase as the water temperature increases, with the maximum at 30°C. Fecundity and reproduction frequency decrease when the temperature exceeds 30°C. Intrinsic growth rate (rm) ranges from 0.168 to 0.195 at 25 to 30°C; net reproduction rate (R0) and finite growth rate (?) are 163 to 264 and 1.183 to 1.215, respectively, when the temperature is greater than 20 and 35°C; population doubling time (t) varies from 3.556 to 4.128 days at temperatures less than 20 and 35°C. Population generation time (T) is negatively correlated with temperature, with the optimal population growth rate at 25 to 30°C.

scholarly journals Development and population growth of Hydra viridissima Pallas, 1766 (Cnidaria, Hydrozoa) in the laboratory

2008 ◽  
Vol 68 (2) ◽  
pp. 379-383 ◽  
Author(s):  
FC. Massaro ◽  
O. Rocha
Keyword(s):  
Growth Rate ◽  
Population Growth ◽  
Generation Time ◽  
Doubling Time ◽  
Test Organism ◽  
Laboratory Culture ◽  
Individual Growth ◽  
Population Doubling ◽  
Population Doubling Time ◽  
The Individual

Hydras, the most representative freshwater Cnidaria, are of common occurrence in bodies of water in every continent except Antarctica. This study was planned with the aim of maintaining a population of Hydra viridissima in laboratory culture to enable the determination of the individual and population growth-rates of this species, as well as its population doubling time and generation time, with a view to employing these common animals as test-organisms in ecotoxicological assays. The organisms were maintained in reconstituted water at 20 ± 2 °C, illuminated at 800 lux with a photoperiod of 12 hours light: 12 hours dark, and were fed on neonates of the cladoceran Ceriodaphnia silvestrii (3 or 4 neonates per hydra, 3 times a week). The individual growth-rate (k) of the species was 0.43, the maximum length of the column 2.53 mm and the generation time 6.6 ± 1.5 days on average. The hydra population showed an intrinsic growth-rate (r) of 0.0468, according to the fitted curve, and a doubling time of 14.8 ± 2.63 days. Hydra viridissima is easy to grow in the laboratory and performs well in the conditions used in this study. It is thus a promising candidate test-organism for ecotoxicological studies.

scholarly journals Morphological and functional characteristics of cell culture derived from the mouse nail unit

2017 ◽  
Vol 5 (1) ◽  
pp. 62-66
Author(s):  
O. Kalmukova ◽  
A. Ustymenko ◽  
T. Lutsenko ◽  
P. Klymenko ◽  
V. Kyryk
Keyword(s):  
Cell Culture ◽  
Growth Rate ◽  
Doubling Time ◽  
Cultured Cells ◽  
Primary Cultures ◽  
Population Doubling ◽  
Synthetic Activity ◽  
Population Doubling Time ◽  
Proliferative Potential

Nail unit is a complex anatomical structure that is capable of rapid growth and regeneration throughout the life. Such significant reparative potential is associated with the presence different types of stem and progenitor cells, whose biology remains one of the fundamental issues today. Taking into account the active search for new stem cell sources for cell therapy, the view of the nail unit as a potential site for the localization of undifferentiated cells with stem potency is topical problem.Purpose. The study was conducted with an objective to establish the morphological, morphometric and proliferative characteristics of cultured cells isolated from the mouse nail unit.Materials and methods. Primary cultures of cells were obtained from tissue sampling, which included areas of the proximal nail fold, nail matrix and onychodermis of the FVB mouse nail organ. Cells were cultured in DMEM:F12 medium with 15 % fetal bovine serum during 6 passages. We determined the colony-forming activity, the population growth rate and doubling time, measured the area of cells, nuclei, and calculated the nuclear-cytoplasmic ratio. For cell morphology analysis, we used staining with Bemer’s hematoxylin and eosin, Heidenhain’s iron hematoxylin and May-Grünwald stain.Results. According to the morphological analysis in vitro the cells from mouse nail unit are heterogeneous with high synthetic activity and a low nuclear-cytoplasmic ratio – the features characteristic of the low-differentiated cells. The population doubling time of the culture was 80 ± 6.5 hours on average, the fastest growing cells were at the 4th passage (63 ± 7 hours). The specific growth rate for cell culture is low (0.01 ± 0.0007).The colony forming efficiency at the 5th passage was only 4 %. A significant number of colonies was small with large poorly proliferative cells, which may indicate a production of large numbers of transitional progenitor cells.Conclusion. The obtained cell culture from the mouse nail unit according to the analysis of their morphology, morphometry and proliferative potential is heterogeneous and requires the further development of pure culture technologies for the detailed characterization of separate subpopulations of cells.

scholarly journals Reproductive ecology of Bombina variegata: characterisation of spawning ponds

1997 ◽  
Vol 18 (2) ◽  
pp. 143-154 ◽  
Author(s):  
Heinz-Ulrich Reyer ◽  
Jonas Barandun
Keyword(s):  
Water Temperature ◽  
Larval Development ◽  
Larval Survival ◽  
Climatic Conditions ◽  
Ephemeral Ponds ◽  
Hyla Arborea ◽  
Invertebrate Predators ◽  
Bombina Variegata ◽  
Dynamic Habitat ◽  
Spawning Sites

AbstractThe use of spawning sites by Bombina variegata was analysed in a dynamic habitat containing a variety of different ponds. Cool or shadowy as well as permanent ponds were not used for spawning at all. Among the ephemeral ponds that were used, egg numbers increased with water temperature, both when compared among ponds and between different areas within ponds. Egg numbers were also higher in ponds of intermediate duration than in those persisting for shorter or longer periods. Ponds of intermediate duration with moderate predator densities and with larvae of competing anuran species (Hyla arborea, Bufo calamita) were used more often than short-lived ponds with no predators and competitors. This pattern of spawn deposition can be interpreted as an attempt to select sites allowing rapid larval development (warm water) and to avoid sites with high numbers of newts and invertebrate predators (permanent ponds). The selection critera seem to be adaptive, because pond duration and desiccation are more important for larval survival than predators and competitors. Yet, optimal reproductive conditions remain highly unpredictable for Bombina variegata, as the characteristics and dynamics of spawning ponds are mainly determined by climatic conditions. Consequently, survival chances of tadpoles can change within a few days or weeks, depending on rainfall and evaporation.

Creating our Future — Some Concerns of an Environmentalist

1994 ◽  
Vol 1 (1) ◽  
pp. 83-86
Author(s):  
George Lewis
Keyword(s):  
Growth Rate ◽  
Population Growth ◽  
Rapid Growth ◽  
Human Population ◽  
Doubling Time ◽  
Gold Coast ◽  
Population Doubling ◽  
Western World ◽  
Population Doubling Time ◽  
The Media

Australia is often described as having the fastest human population growth in the western world at 1.4 per cent per annum (ABS 1993). Queensland's growth rate in comparison is 2.52 per cent while the Gold Coast is currently experiencing 6.1 per cent which is equivalent to a population doubling time of 11 years. While such rapid growth is lauded in the media and discussed in glowing terms by economists, engineers and entrepreneurs, there are many others who in recent years have queried the wisdom of such rapidly increasing growth. In 1992 a group calling themselves The Union of Concerned Scientists, ‘comprising 1575 scientists from 69 countries, including a majority of Nobel laureates’ (Caswell 1) issued a ‘Warning to Humanity’ regarding the accelerating damage threatening humanity's global support systems. According to this group, ‘no more than one or a few decades remain before the chance to avert the threats we now confront will be lost and the prospects for humanity immeasurably diminished’. They refer specifically to over-consumption, poverty and spiralling populations: all of which we have in south-east Queensland.

Incubation Temperature Influences the Duration of Egg Hatching and Early Development in the Boreal Digging Frog, Kaloula Borealis

2020 ◽  
Vol 3 (1) ◽  
pp. ACCEPTED
Author(s):  
Rho-Jeong Rae
Keyword(s):  
Water Temperature ◽  
Early Life ◽  
Rainy Season ◽  
Incubation Temperature ◽  
Life Stages ◽  
Early Life Stages ◽  
Egg Hatching ◽  
Significant Difference ◽  
The Mean ◽  
Hatching Rates

This study investigated the boreal digging frog, Kaloula borealis, to determine the egg hatching period and whether the hatching period is affected by incubation temperature. The results of this study showed that all the eggs hatched within 48 h after spawning, with 28.1% (±10.8, n=52) hatching within 24 h and 99.9% (±0.23, n=49) within 48 h after spawning. A significant difference was noted in the mean hatching proportion of tadpoles at different water temperatures. The mean hatching rates between 15 and 24 h after spawning was higher at a water temperature of 21.1 (±0.2) °C than at 24.1 (±0.2) °C. These results suggest that incubation temperature affected the early life stages of the boreal digging frog, since they spawn in ponds or puddles that form during the rainy season.

Increased water temperature interrupts embryonic and larval development of Indian major carp rohu Labeo rohita

2021 ◽  
Author(s):  
Mohammad Ashaf-Ud-Doulah ◽  
S. M. Majharul Islam ◽  
Md Mahiuddin Zahangir ◽  
Md Sadiqul Islam ◽  
Christopher Brown ◽  
...  
Keyword(s):  
Water Temperature ◽  
Larval Development ◽  
Labeo Rohita ◽  
Indian Major Carp ◽  
Embryonic And Larval Development

scholarly journals Expansion and characterization of bone marrow derived human mesenchymal stromal cells in serum-free conditions

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Samatha Bhat ◽  
Pachaiyappan Viswanathan ◽  
Shashank Chandanala ◽  
S. Jyothi Prasanna ◽  
Raviraja N. Seetharam
Keyword(s):  
Bone Marrow ◽  
Mesenchymal Stromal Cells ◽  
Stromal Cells ◽  
Population Doubling ◽  
Seeding Density ◽  
Population Doubling Time ◽  
Differentiation Potential ◽  
Serum Free ◽  
Safety Issues ◽  
Free Media

AbstractBone marrow-derived mesenchymal stromal cells (BM-MSCs) are gaining increasing importance in the field of regenerative medicine. Although therapeutic value of MSCs is now being established through many clinical trials, issues have been raised regarding their expansion as per regulatory guidelines. Fetal bovine serum usage in cell therapy poses difficulties due to its less-defined, highly variable composition and safety issues. Hence, there is a need for transition from serum-based to serum-free media (SFM). Since SFM are cell type-specific, a precise analysis of the properties of MSCs cultured in SFM is required to determine the most suitable one. Six different commercially available low serum/SFM with two different seeding densities were evaluated to explore their ability to support the growth and expansion of BM-MSCs and assess the characteristics of BM-MSCs cultured in these media. Except for one of the SFM, all other media tested supported the growth of BM-MSCs at a low seeding density. No significant differences were observed in the expression of MSC specific markers among the various media tested. In contrary, the population doubling time, cell yield, potency, colony-forming ability, differentiation potential, and immunosuppressive properties of MSCs varied with one another. We show that SFM tested supports the growth and expansion of BM-MSCs even at low seeding density and may serve as possible replacement for animal-derived serum.

scholarly journals Effect of Inflammation on Gingival Mesenchymal Stem/Progenitor Cells’ Proliferation and Migration through Microperforated Membranes: An In Vitro Study

2020 ◽  
Vol 2020 ◽  
pp. 1-10 ◽  
Author(s):  
M. Al Bahrawy ◽  
K. Ghaffar ◽  
A. Gamal ◽  
K. El-Sayed ◽  
V. Iacono
Keyword(s):  
Pore Size ◽  
Progenitor Cells ◽  
Cellular Migration ◽  
Gingival Tissue ◽  
Population Doubling ◽  
Population Doubling Time ◽  
Electron Microscopic ◽  
Healthy Human ◽  
Membrane Pores ◽  
Scanning Electron

Background. In the field of periodontal guided tissue regeneration, microperforated membranes have recently proved to be very promising periodontal regenerative tissue engineering tools. Regenerative periodontal approaches, employing gingival mesenchymal stem/progenitor cells in combination with these novel membranes, would occur mostly in inflamed microenvironmental conditions intraorally. This in turn entails the investigation into how inflammation would affect the proliferation as well as the migration dynamics of gingival mesenchymal stem/progenitor cells. Materials and Methods. Clones of human gingival mesenchymal stem/progenitor cells (GMSCs) from inflamed gingival tissues were characterized for stem/progenitor cells’ characteristics and compared to clones of healthy human GMSCs (n=3), to be subsequently seeded on perforated collagen-coated poly-tetra-floro-ethylene (PTFE) membranes with a pore size 0.4 and 3 microns and polycarbonic acid membranes of 8 microns pore size in Transwell systems. The population doubling time and the MTT test of both populations were determined. Fetal bovine serum (FBS) was used as a chemoattractant in the culturing systems, and both groups were compared to their negative controls without FBS. Following 24 hours of incubation period, migrating cells were determined on the undersurface of microperforated membranes and the membrane-seeded cells were examined by scanning electron microscopy. Results. GMSCs demonstrated all predefined stem/progenitor cell characteristics. GMSCs from inflamed gingival tissues showed significantly shorter population doubling times. GMSCs of inflamed and healthy tissues did not show significant differences in their migration abilities towards the chemoattractant, with no cellular migration observed in the absence of FBS. GMSCs from healthy gingival tissue migrated significantly better through larger micropores (8 microns). Scanning electron microscopic images proved the migratory activity of the cells through the membrane pores. Conclusions. Inflammation appears to boost the proliferative abilities of GMSCs. In terms of migration through membrane pores, GMSCs from healthy as well as inflamed gingival tissues do not demonstrate a difference in their migration abilities through smaller pore sizes, whereas GMSCs from healthy gingival tissues appear to migrate significantly better through larger micropores.

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