Patterns of metamorphic age and length in marine fishes, from individuals to taxa

2000 ◽  
Vol 57 (4) ◽  
pp. 856-869 ◽  
Author(s):  
Hugues P Benoît ◽  
Pierre Pepin ◽  
Joseph A Brown
Keyword(s):  
Growth Rate ◽  
Population Level ◽  
Individual Variability ◽  
Marine Fishes ◽  
Exponential Relationship ◽  
Factors Affecting ◽  
The Mean ◽  
Time Required ◽  
Increasing Temperature ◽  
Dominant Influence

We present a summary of variability in age and length at metamorphosis for marine fishes. Data from the literature were partitioned into taxonomic, population, and individual levels of resolution to examine the factors affecting the timing of metamorphosis. Temperature appears to be a dominant influence on timing, likely due to its effect on growth rate. Interspecifically, length at metamorphosis correlated poorly with that at hatching but was significantly related to temperature. This pattern was inconsistent for population-level comparisons. Metamorphic age decreased exponentially with increasing temperature in interspecific and population-level comparisons but did not covary with length for either level of resolution. This suggests that age at metamorphosis largely reflects the time required to grow to a given metamorphic length. Within populations, the correlation between metamorphic age and length increases with growth rate, a reflection of variance in age and length. A strong exponential relationship between mean metamorphic age and length and their associated variability (SD) exists, with a slope greater than unity in both cases (i.e., variability increases relative to the mean). With these relationships, we can infer the manner in which individual variability in metamorphic traits is generated throughout ontogeny. These results are considered in light of recruitment variability in marine fishes.

scholarly journals Noise-driven growth rate gain in clonal cellular populations

2016 ◽  
Vol 113 (12) ◽  
pp. 3251-3256 ◽  
Author(s):  
Mikihiro Hashimoto ◽  
Takashi Nozoe ◽  
Hidenori Nakaoka ◽  
Reiko Okura ◽  
Sayo Akiyoshi ◽  
...  
Keyword(s):  
Growth Rate ◽  
Population Growth ◽  
Single Cell ◽  
Single Cells ◽  
Population Level ◽  
Growth Conditions ◽  
Cell Dynamics ◽  
Generation Times ◽  
Complex Population ◽  
The Mean

Cellular populations in both nature and the laboratory are composed of phenotypically heterogeneous individuals that compete with each other resulting in complex population dynamics. Predicting population growth characteristics based on knowledge of heterogeneous single-cell dynamics remains challenging. By observing groups of cells for hundreds of generations at single-cell resolution, we reveal that growth noise causes clonal populations of Escherichia coli to double faster than the mean doubling time of their constituent single cells across a broad set of balanced-growth conditions. We show that the population-level growth rate gain as well as age structures of populations and of cell lineages in competition are predictable. Furthermore, we theoretically reveal that the growth rate gain can be linked with the relative entropy of lineage generation time distributions. Unexpectedly, we find an empirical linear relation between the means and the variances of generation times across conditions, which provides a general constraint on maximal growth rates. Together, these results demonstrate a fundamental benefit of noise for population growth, and identify a growth law that sets a “speed limit” for proliferation.

scholarly journals Growth Rate Variation and Larval Survival: Inferences from an Individual-Based Size-Dependent Predation Model

1993 ◽  
Vol 50 (1) ◽  
pp. 133-142 ◽  
Author(s):  
James A. Rice ◽  
Thomas J. Miller ◽  
Kenneth A. Rose ◽  
Larry B. Crowder ◽  
Elizabeth A. Marschall ◽  
...  
Keyword(s):  
Growth Rate ◽  
Growth Rates ◽  
Individual Variability ◽  
Individual Growth ◽  
Rate Variation ◽  
High Survival ◽  
Initial Growth ◽  
Size Dependent ◽  
The Mean ◽  
Selection For

We used an individual-based Monte Carlo simulation model to explore how changes in the mean and variance of growth rates of individuals in a larval fish cohort interact with size-dependent predation to affect the number and characteristics of individual survivors. Small changes in initial cohort mean growth rate can change survival over the first 60 d of life 10-to 30-fold. But when variance in growth rate among individuals is high, survival can be substantially higher than expected from the initial mean cohort growth rate. Selection for faster-growing individuals becomes stronger with increasing variance and increasing predation rate. In some cases, > 80% of the survivors may come from the upper 25% of the initial growth rate distribution, and the mean growth rate of the survivors may exceed twice the initial mean growth rate. When individual growth rates change from day to day rather than remaining constant, the contribution of atypical individuals is accentuated even further. Counterintuitively, most of the selection for faster-growing individuals happens only after the majority of mortality has already taken place. These results suggest that interactions between individual variability and selective mortality may have important cohort-level implications for survival in fishes.

The cultivation of Chondrus crispus. Factors affecting growth under greenhouse conditions

1977 ◽  
Vol 55 (16) ◽  
pp. 2263-2271 ◽  
Author(s):  
A. C. Neish ◽  
P. F. Shacklock ◽  
C. H. Fox ◽  
F. J. Simpson
Keyword(s):  
Growth Rate ◽  
Dry Matter ◽  
Continuous Illumination ◽  
Chondrus Crispus ◽  
Optimum Conditions ◽  
High Nitrogen ◽  
Good Source ◽  
Factors Affecting ◽  
Rapid Growth Rate ◽  
The Mean

Two methods of growing Chondrus crispus in flowing seawater in tanks in a greenhouse were used in determining some of the conditions required for the cultivation of C. crispus. In one system, individual plants were tethered to a fixed support, and in the other, the plants were allowed to float freely in circulating seawater. The addition of nitrate or ammonia and phosphate increased the growth rate, whereas iron did not. Urea was not a good source of nitrogen. Well nourished plants had a relatively high nitrogen and water content and were richly pigmented. Such plants, when grown in nutrient-deficient seawater, gradually bleached and the percentage of dry matter and carrageenan increased. Growth under conditions of continuous illumination was superior to normal illumination with alternating day and night periods. Seasonal variation in growth rates was closely correlated with the mean ambient temperature of the seawater. Epiphytes were a serious problem but became less so as optimum conditions for growth of C. crispus were approached. A single plant (T4), observed to have a relatively rapid growth rate, was selected and a clone was established by vegetative propagation.

scholarly journals Factors Affecting Birth Weight And Growth Rate In Friesian X Bunaji Calves

2021 ◽  
Vol 19 ◽  
pp. 101-106
Author(s):  
O. W. Ehoche ◽  
A. E. O. Malau-aduli ◽  
B. Y. Abubakar
Keyword(s):  
Growth Rate ◽  
Body Weight ◽  
Birth Weight ◽  
Significant Influence ◽  
Season Of Birth ◽  
Correction Factors ◽  
Wet Season ◽  
Factors Affecting ◽  
Body Weights ◽  
The Mean

Calving records from 1984 - 1989 were studied to determine the influence of rearing method, sex of calf, season of birth, dam breed and year of birth on body weight at birth, 3,6 and 12 months of age in Friesian x Bunaji calves. The mean weights of calves at birth, 3, 6 and 12 months of age were 22.0, 68.2, 96.7 and 137.4 kg, respectively. Sex of calf had a significant effect, with male calves being heavier than the females by 1.2, 5.9 and 9.7 kg at birth, 3 and 6 months of age respectively. The effect of season of birth on calf body weights was not significant except at 6 months of age, when calves born during the wet season were heavier (P<0.01) than those born in the harmattan period by 9.5 kg. Year of birth had a highly significant effect (P<0.01) on calf weights from birth to yearling. Method of rearing and dam breed had no significant influence on all the weights. The results suggest the need to develop correction factors for standardisation of weight records when comparing dams on the basis of body weights of their calves.

INDIVIDUAL VARIATION OF GROWTH AND FILTRATION RATES OF MUSSELS MYTILUS GALLOPROVINCIALIS LAM

2017 ◽  
Author(s):  
Irina Kazankova ◽  
Irina Kazankova ◽  
Elena Vasechkina ◽  
Elena Vasechkina
Keyword(s):  
Growth Rate ◽  
Individual Variation ◽  
Coefficient Of Variation ◽  
Individual Variability ◽  
Individual Growth ◽  
Rate Variation ◽  
Sample Mean ◽  
Metabolic Costs ◽  
Individual Growth Rate ◽  
The Mean

Research on individual variation of the filtration and growth rates of mussels was based both on the authors’ field and laboratory experiments and literature data analysis. High individual variability of these characteristics was recorded during the tests. The coefficient of variation grew up as the mean rate diminished. Under low specific growth rate the coefficient of variation (ratio of root-mean-square deviation to the sample mean) could exceed 100 %. Tests revealed the power-law relation of the coefficient of variation from the average for studied characteristics. That relation could be seen in filtration and growth rate charts; it was also true for estimates of production energy and metabolic costs. The exponent varied from -0.36 to -0.77. Individual growth rate variation of mussels was concluded to be an important criterion of the favorability of environmental conditions.

INDIVIDUAL VARIATION OF GROWTH AND FILTRATION RATES OF MUSSELS MYTILUS GALLOPROVINCIALIS LAM

2017 ◽  
Author(s):  
Irina Kazankova ◽  
Irina Kazankova ◽  
Elena Vasechkina ◽  
Elena Vasechkina
Keyword(s):  
Growth Rate ◽  
Individual Variation ◽  
Coefficient Of Variation ◽  
Individual Variability ◽  
Individual Growth ◽  
Rate Variation ◽  
Sample Mean ◽  
Metabolic Costs ◽  
Individual Growth Rate ◽  
The Mean

Research on individual variation of the filtration and growth rates of mussels was based both on the authors’ field and laboratory experiments and literature data analysis. High individual variability of these characteristics was recorded during the tests. The coefficient of variation grew up as the mean rate diminished. Under low specific growth rate the coefficient of variation (ratio of root-mean-square deviation to the sample mean) could exceed 100 %. Tests revealed the power-law relation of the coefficient of variation from the average for studied characteristics. That relation could be seen in filtration and growth rate charts; it was also true for estimates of production energy and metabolic costs. The exponent varied from -0.36 to -0.77. Individual growth rate variation of mussels was concluded to be an important criterion of the favorability of environmental conditions.

The incidence of central serous chorioretinopathy in the population of Kazan: Results of a retrospective epidemiological analysis for 2009–2018

2020 ◽  
pp. 30-33
Author(s):  
D. R. Аgliullin ◽  
G. R. Khasanova ◽  
E. A. Abdulaeva ◽  
S. T. Agliullina ◽  
A. N. Amirov ◽  
...  
Keyword(s):  
Growth Rate ◽  
Central Serous Chorioretinopathy ◽  
Morbidity Rate ◽  
Seasonal Prevalence ◽  
Upward Trend ◽  
Epidemiological Analysis ◽  
Significant Upward Trend ◽  
Track Record ◽  
Minimum Age ◽  
The Mean

Objective: To assess the incidence of central serous chorioretinopathy (CSC) through the example of a large industrial Russian city.Methods: A retrospective analysis of CSC of Kazan population for 2009–2018 has been done.Results: From 2019 to 2018, 831 new cases of CSC were registered in Kazan. A statistically significant upward trend with growth rate 105.2% and accession rate 5.2% was typical for the annual track record. The mean age of patients was 50 years, the minimum age was 14 years, the maximum age was 87 years. A statistically significant upward trend was detected in track record of incidence in groups of 30–39-year-old and 40–49-year-old. Seasonal increase of the incidence was recorded in February, March, April, October, and November.Conclusions: The upward trend and seasonal prevalence are typical for longterm morbidity of CSC in Kazan. The highest morbidity rate of CSC and statistically significant upward trend of its incidence in track record were recorded in the age of 30–39. 

Continuous Precipitation of Lead Iodide

1994 ◽  
Vol 59 (7) ◽  
pp. 1503-1510
Author(s):  
Stanislav Žáček ◽  
Jaroslav Nývlt
Keyword(s):  
Growth Rate ◽  
Particle Size ◽  
Crystal Size ◽  
Crystal Growth Rate ◽  
Laboratory Model ◽  
Lead Iodide ◽  
Secondary Nucleation ◽  
Equimolar Ratio ◽  
Continuous Precipitation ◽  
The Mean

Lead iodide was precipitated from aqueous solutions of 0.015 - 0.1 M Pb(NO3)2 and 0.03 - 0.2 M KI in the equimolar ratio using a laboratory model of a stirred continuous crystallizer at 22 °C. After reaching the steady state, the PbI2 crystal size distribution was measured sedimentometrically and the crystallization kinetics was evaluated based on the mean particle size. Both the linear crystal growth rate and the nucleation rate depend on the specific output of the crystallizer. The system crystallization constant either points to a significant effect of secondary nucleation by the mechanism of contact of the crystals with the stirrer blade, or depends on the concentrations of the components added due to the micromixing mechanism.

scholarly journals Proximity of the middle meningeal artery and maxillary artery to the mandibular head and mandibular neck as revealed by three-dimensional time-of-flight magnetic resonance angiography

2021 ◽  
Author(s):  
Daphne Schönegg ◽  
Raphael Ferrari ◽  
Julian Ebner ◽  
Michael Blumer ◽  
Martin Lanzer ◽  
...  
Keyword(s):  
Magnetic Resonance ◽  
Magnetic Resonance Angiography ◽  
Three Dimensional ◽  
Time Of Flight ◽  
Middle Meningeal Artery ◽  
Individual Variability ◽  
Maxillary Artery ◽  
Condylar Process ◽  
The Mean ◽  
Meningeal Artery

Abstract Purpose The close topographic relationship between vascular and osseous structures in the condylar and subcondylar region and marked variability in the arterial course has been revealed by both imaging and cadaveric studies. This study aimed to verify the previously published information in a large sample and to determine a safe surgical region. Methods We analyzed the three-dimensional time-of-flight magnetic resonance angiography images of 300 individuals. Results The mean distance between the middle meningeal artery and the apex of the condyle or the most medial point of the condyle was 18.8 mm (range: 11.2–25.9 mm) or 14.5 mm (range: 8.8–22.9 mm) respectively. The course of the maxillary artery relative to the lateral pterygoid muscle was medial in 45.7% of cases and lateral in 54.3%. An asymmetric course was evident in 66 patients (22%). The mean distance between the maxillary artery and condylar process at the deepest point of the mandibular notch was 6.2 mm in sides exhibiting a medial course (range: 3.7–9.8 mm) and 6.6 mm in sides exhibiting a lateral course (range: 3.9–10.4 mm). The distances were significantly influenced by age, gender, and the course of the maxillary artery. Conclusion Our study emphasizes the marked inter- and intra-individual variability of the maxillary and middle meningeal arterial courses. We confirmed the proximity of the arteries to the condylar process. Extensive surgical experience and thorough preparation for each individual case are essential to prevent iatrogenic vascular injury.

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