scholarly journals MULTIPLE-LOCUS HETEROZYGOSITY AND THE PHYSIOLOGICAL ENERGETICS OF GROWTH IN THE COOT CLAM, MULINIA LATERALIS, FROM A NATURAL POPULATION

Genetics ◽  
1984 ◽  
Vol 108 (2) ◽  
pp. 445-455
Author(s):  
David W Garton ◽  
Richard K Koehn ◽  
Timothy M Scott
Keyword(s):  
Growth Rate ◽  
Negative Relationship ◽  
Physiological Mechanism ◽  
Ammonia Excretion ◽  
Energy Budgets ◽  
Starch Gel Electrophoresis ◽  
Feeding Rates ◽  
Multiple Locus ◽  
Metabolic Costs ◽  
The Relationship

ABSTRACT The relationship between individual energy budgets and multiple-locus heterozygosity at six polymorphic enzyme loci was examined in Mulinia lateralis. Energy budgets were determined by measuring growth rates, rates of oxygen consumption, ammonia excretion and clearance rates. Enzyme genotypes were determined using starch gel electrophoresis. Growth rate and net growth efficiency (the ratio of energy available for growth to total energy absorbed) increased with individual heterozygosity. The positive relationship between observed growth and multiple-locus heterozygosity was associated with a negative relationship between routine metabolic costs and increasing heterozygosity. Reduction in routine metabolic costs explained 60% of the observed increased growth of more heterozygous individuals. When routine metabolic costs were standardized for differences in feeding rates, these standard metabolic costs explained 97% of the differences in growth rate. Lower standard metabolic costs, associated with increasing heterozygosity, have been proposed as a physiological mechanism for the relationship between multiple-locus heterozygosity and growth rate that has been reported for a variety of organisms, ranging in diversity from aspens to humans. This study demonstrates that reduction of standard metabolic costs, at least in clams, accounts for virtually all of the differences in growth rate among individuals of differing heterozygosity.

scholarly journals Relationship between habitat distribution, growth rate, and plasticity in congeneric larval dragonflies

2005 ◽  
Vol 83 (8) ◽  
pp. 1128-1133 ◽  
Author(s):  
S J McCauley
Keyword(s):  
Growth Rate ◽  
Predation Risk ◽  
Growth Rates ◽  
Lepomis Macrochirus ◽  
Negative Relationship ◽  
Activity Level ◽  
Activity Levels ◽  
Habitat Distribution ◽  
Invertebrate Predators ◽  
The Relationship

The relationship between habitat distribution, growth rate, and plasticity was examined in the larvae of three species of dragonfly in the genus Libellula L., 1758. Growth rates were compared under three conditions: in the absence of predation risk, in the presence of sunfish (Lepomis macrochirus Rafinesque, 1819; Pisciformes: Centrachidae), and in the presence of invertebrate predators. I assessed how the habitat distributions of the three species of dragonfly, specifically how commonly they occur with fish, were related to growth rates and to the level of growth plasticity under different levels of perceived predation risk. There was a negative relationship between growth rate and the frequency with which species coexist with sunfish. Growth-rate plasticity was limited and does not appear to be important in determining the ability of species to coexist with alternative top predator types. Only one species exhibited growth-rate plasticity, decreasing growth in response to the predator with which it most commonly coexists but not to the species which poses the greatest predation risk. A comparison of growth rates and activity levels in the presence and absence of these predators suggests that growth and activity level parallel each other in these species.

Growth and early sexual maturation in Baltic salmon (Salmo salar) parr

1992 ◽  
Vol 70 (2) ◽  
pp. 205-211 ◽  
Author(s):  
Ingemar Berglund
Keyword(s):  
Growth Rate ◽  
Salmo Salar ◽  
Sexual Maturation ◽  
Specific Growth ◽  
Gonadal Development ◽  
Feeding Rates ◽  
Gonadal Growth ◽  
Hatchery Stock ◽  
Size At Age ◽  
The Relationship

The relationship between sexual maturation and growth in Baltic salmon (Salmo salar) parr was studied in hatchery stock originating from the Umeälven (Ume River) in northern Sweden. The probability that a male parr would mature sexually at age 1 + was positively related to its size at the start of the experiment at age 0+. The specific growth rate and condition factor of maturing and nonmaturing males were similar until the onset of gonadal growth, when the growth rate of maturing males decreased. Sibling groups of immature parr were fed different rations during the 3 weeks prior to the start of gonadal development. The incidence of sexual maturation in the groups given different rations was linearly related to the growth rate during the period of different feeding rates. This study suggests that both the size at age 1, resulting from the growth rate during the first summer, and the opportunity for growth during the period preceding the onset of gonadal growth affect the incidence of maturation in male parr of age 1 +.

THE RELATIONSHIP BETWEEN CELL LENGTH AND RING WIDTH AND CIRCUMFERENTIAL GROWTH RATE IN FIVE CANADIAN SPECIES

IAWA Journal ◽  
2000 ◽  
Vol 21 (3) ◽  
pp. 335-345 ◽  
Author(s):  
S. Fujiwara ◽  
K. C. Yang
Keyword(s):  
Growth Rate ◽  
Black Spruce ◽  
Negative Relationship ◽  
Ring Width ◽  
White Spruce ◽  
Jack Pine ◽  
Cell Length ◽  
Balsam Fir ◽  
Trembling Aspen ◽  
The Relationship

Variation in cell length and the relationship between cell length and ring width and circumferential growth rate were studied in jack pine (Pinus banksiana Lamb.), balsam fir (Abies balsamea Mill.), white spruce (Picea glauca Voss), black spruce (Picea mariana Britton, Sterns & Pogg.) and trembling aspen (Populus tremuloides Michx.) collected in the natural forest in Ontario, Canada. There was a negative relationship between cell length and ring width in jack pine, balsam fir and black spruce, and a positive relationship in trembling aspen. No relationship was found in white spruce. There was a negative relationship between tracheid length and circumferential growth rate in all conifers. In trembling aspen fibre length decreased in both higher and lower circumferential growth rate. Circumferential growth rate is a good index of the effect of tree growth on cell length.

Spatial Variation in Food-Limited Growth of Juvenile Greenback Flounder, Rhombosolea tapirina: Evidence from Otolith Daily Increments and Otolith Scaling

1993 ◽  
Vol 50 (12) ◽  
pp. 2558-2567 ◽  
Author(s):  
Gregory P. Jenkins ◽  
Megan Shaw ◽  
Bryce D. Stewart
Keyword(s):  
Growth Rate ◽  
Growth Rates ◽  
Somatic Growth ◽  
Feeding Rates ◽  
Otolith Growth ◽  
Somatic Growth Rate ◽  
Daily Increment ◽  
Daily Increments ◽  
Highly Correlated ◽  
The Relationship

Growth rates of juvenile flounder, Rhombosolea tapirina, determined from daily increment number, and the relationship between otolith and fish sizes (otolith scaling), were compared between two adjacent areas. Swan Bay, Victoria, a sheltered bay with a well-developed seagrass-detrital system, supports higher populations of prey and feeding rates of juvenile flounder than Port Phillip Bay, an area more exposed to waves and tidal currents. Temperature was significantly higher in Swan Bay (though generally less than 1 °C). Growth rates determined from daily increment number were similar within bays, but significantly different between bays. The pooled growth rate for Swan Bay (0.29 mm∙d−1) was significantly higher than for Port Phillip Bay (0.17 mm∙d−1). The same pattern was found for otolith scaling. Most of the variation in growth rates between the two bays was apparently related to food supply. A laboratory experiment indicated that otolith growth rate had a minimum level which was independent of somatic growth rate, and an additional component which was highly correlated with somatic growth rate. This resulted in an exponential decrease in otolith growth per unit somatic growth with increasing somatic growth rate such that variation in otolith scaling would be greatest at low growth rates.

scholarly journals Impact of Public & Foreign Direct Investment on the Economy of Bangladesh

2021 ◽  
pp. 227-246
Author(s):  
Md Kamrul Islam ◽  
Sabid Khan ◽  
Zareen Haider
Keyword(s):  
Growth Rate ◽  
Time Series Data ◽  
Public Investment ◽  
Negative Relationship ◽  
Series Data ◽  
Fdi Inflows ◽  
Fixed Capital Formation ◽  
Relationship Of ◽  
The Impact ◽  
The Relationship

This paper is to investigate the impact of public investment and FDI on GDP growth of Bangladesh. The Gross Fixed Capital Formation represents public investment of our country and we have taken FDI (inflows) as the variable while the GDP is the dependent variable. The time series data has been included here, which will be kept stationary, followed by a regression. As public investment and FDI are the independent variables, it is expected that they both have a positive relation with the dependent variable. Although, FDI may have a negative relationship to the growth. The relationship of FDI with growth rate can be used to show whether a country is in scarce of capital or not. The objective is to identify the relationship of public investment and FDI to the growth and to what extent these investments have an impact on the growth rate. By showing the estimated relationship of FDI to the GDP or growth, we are going to know whether our country is capital abundant or labor abundant.

scholarly journals Identifying reliable fitness proxies for growing animals responding to anthropogenic changes

2020 ◽  
Author(s):  
Andrew D. Higginson
Keyword(s):  
Growth Rate ◽  
Mortality Rate ◽  
Predation Risk ◽  
Energy Use ◽  
Metabolic Costs ◽  
Theoretical Predictions ◽  
Increasing Temperature ◽  
The Impact ◽  
The Relationship ◽  
Increase Mortality Rate

ABSTRACTAnthropogenic influences on habitats often affect predation on species by introducing novel predators, supporting additional predators, or reducing animals’ ability to detect or avoid predators. Other changes may reduce the ability of animals to feed, or alter their energy use. An increase in predation risk is assumed to reduce prey populations by increasing mortality, reducing foraging and growth. Often animals don’t appear to have been adversely affected, or may even increase growth rate. However, theoretical predictions that may have been overlooked suggest that optimal foraging rate, mortality rate and growth rate may change in counter-intuitive ways, depending on exactly how predation risk or costs have been increased. Increasing predator density may increase mortality rate when foraging, reduce the safety of refuges, or alter the relationship between vigilance and attack likelihood. Increasing temperature may increase metabolic costs in ectotherms and reduce thermogenesis costs in endotherms, which affects the costs of active foraging and inactivity differently. Here, I review the theory on how predation risk and metabolic costs should affect foraging behaviour, mortality and growth in order to explain the great variation in behavioural responses. I show that in some situations animals may not respond behaviourally even though a change severely affects survival, and the mortality may be a poor metric of the impact of a change on population viability. In other situations a fitness proxy may change dramatically whilst fitness is unaffected due to compensatory changes in behaviour or life history. Other measures may change in a positive way whilst fitness declines. I describe how to identify the situations in the field and thereby make reliable measure of fitness in particular study systems. Overall, this work shows how behavioural theory can help understand the impacts of environmental change and highlights promising directions to better understand and mitigate their effects on ecosystems.

ABSCISIC ACID PRODUCTION BY PLEUROTUS FLORIDA CULTURED IN VARIOUS CONDITIONS AND ITS RELATION TO GROWTH

1997 ◽  
Vol 45 (1) ◽  
pp. 19-22 ◽  
Author(s):  
Serpil ÜNyayar ◽  
Ş. Fatih Topcuoglu ◽  
Suna Bozcuk
Keyword(s):  
Growth Rate ◽  
Abscisic Acid ◽  
Acid Production ◽  
Negative Relationship ◽  
Growth Period ◽  
Dry Weight ◽  
Pleurotus Florida ◽  
Static Conditions ◽  
The Relationship ◽  
Aba Synthesis

The levels of endogenous free, bound, and total abscisic acid (ABA) and the changes in dry weight of the mycelium depending on the culture periods were examined inPleurotus florida (Basidiomycetes)cultured both in shaking and static media. The relationship between ABA production and the growth rate of the fungus was determined. Our findings show that this fungus synthesizes ABA as a secondary metabolite and the maximum total ABA is produced on the 24th day of the growth period in both shaking and static conditions. It was observed that, depending on the culture period, the dry weight of mycelium was enhanced in the primary metabolic phase, while it was constant in the secondary metabolic phase.These results show that there is a negative relationship between growth rate of the fungus and ABA synthesis.

Risk Attitude and Corporate Investment under Output Market Uncertainty: Evidence from The Mekong River Delta, Vietnam

2016 ◽  
pp. 59-70
Author(s):  
Ninh Le Khuong ◽  
Nghiem Le Tan ◽  
Tho Huynh Huu
Keyword(s):  
Negative Relationship ◽  
Risk Attitude ◽  
Business Strategies ◽  
Risk Averse ◽  
Market Uncertainty ◽  
Firm Investment ◽  
Output Market ◽  
The Impact ◽  
The Relationship

This paper aims to detect the impact of firm managers’ risk attitude on the relationship between the degree of output market uncertainty and firm investment. The findings show that there is a negative relationship between these two aspects for risk-averse managers while there is a positive relationship for risk-loving ones, since they have different utility functions. Based on the findings, this paper proposes recommendations for firm managers to take into account when making investment decisions and long-term business strategies as well.

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