Allometric Models of Simuliid Growth Rates and Their Use for Estimation of Production

1988 ◽  
Vol 45 (2) ◽  
pp. 315-324 ◽  
Author(s):  
Antoine Morin ◽  
Michel Constantin ◽  
Robert Henry Peters
Keyword(s):  
Water Temperature ◽  
Significant Influence ◽  
Growth Rates ◽  
Dry Mass ◽  
Published Data ◽  
Power Relationship ◽  
Square Root ◽  
Allometric Model ◽  
Simulium Vittatum ◽  
Individual Mass

Growth rates of Prosimulium mixtum/fuscum, Stegopterna mutata, and Simulium vittatum are described in relation to individual mass, water temperature, and seston quality in the outlet of Lake Orford (southern Quebec) in the winter of 1985–86. Growth rates in mass (G, per day) of the three species were similar and inversely related to dry mass (DM, micrograms) following the power relationship G = 0.11 DM−0.28; neither water temperature nor seston abundance and quality varied sufficiently during the study period to have a significant influence on growth rates. The allometric model was used to estimate production of the three species, and the resulting estimates are compared with cohort methods and size–frequency estimates. Large larvae were responsible for most of the production, and most of the production occurred before the spring rise in water temperature. Measured growth rates in winter are significantly lower than those reported for simuliids in warmer waters. A reanalysis of published data shows that growth rates of simuliids increase as the square root of water temperature (T, degrees Celsius) (G = 0.08 DM−0.21 T0.48).

Modèles empiriques de la production annuelle et du rapport P/B d'invertébrés benthiques d'eau courante

1992 ◽  
Vol 49 (3) ◽  
pp. 532-539 ◽  
Author(s):  
Antoine Morin ◽  
Nathalie Bourassa
Keyword(s):  
Water Temperature ◽  
Marine Invertebrates ◽  
Dry Mass ◽  
Log P ◽  
Published Data ◽  
Running Waters ◽  
Running Water ◽  
Taxonomic Groups ◽  
The Relationship ◽  
Individual Mass

Published data on secondary production of running water invertebrates are analyzed by multiple regression to quantify the relationship between productivity (P, in grams dry mass per square metre per year) and biomass (B, in grams dry mass per square metre), mean individual mass (M, in grams dry mass), and annual mean water temperature (T, in degrees Celsius) to compare productivity of major taxonomic groups and to compare to invertebrate populations from other aquatic ecosystems. The equation P = 0.18 B1.01M−0.34 100.037T explains 87% of the variability in log P in the 291 lotic invertebrate populations analyzed. Significant differences were detected among major taxonomic groups, but these differences account for only about 4% of the variability in log P. Once the effect of biomass, mean individual mass and water temperature are taken into account, productivity of lake and stream invertebrate populations is quite similar, although productivity is a linear function of biomass in streams and not in lakes. Comparison of models for running waters, lake and marine ecosystems suggests that marine invertebrates are less productive than freshwater populations.

scholarly journals New Mathematical Modeling Approach for Predicting Microbial Inactivation by High Hydrostatic Pressure

2007 ◽  
Vol 73 (8) ◽  
pp. 2468-2478 ◽  
Author(s):  
Bernadette Klotz ◽  
D. Leo Pyle ◽  
Bernard M. Mackey
Keyword(s):  
Microbial Inactivation ◽  
Inactivation Kinetics ◽  
Published Data ◽  
Model Parameters ◽  
Order Kinetic ◽  
Square Root ◽  
Additional Time ◽  
Decimal Reduction Time ◽  
First Order ◽  
Primary Model

ABSTRACT A new primary model based on a thermodynamically consistent first-order kinetic approach was constructed to describe non-log-linear inactivation kinetics of pressure-treated bacteria. The model assumes a first-order process in which the specific inactivation rate changes inversely with the square root of time. The model gave reasonable fits to experimental data over six to seven orders of magnitude. It was also tested on 138 published data sets and provided good fits in about 70% of cases in which the shape of the curve followed the typical convex upward form. In the remainder of published examples, curves contained additional shoulder regions or extended tail regions. Curves with shoulders could be accommodated by including an additional time delay parameter and curves with tails shoulders could be accommodated by omitting points in the tail beyond the point at which survival levels remained more or less constant. The model parameters varied regularly with pressure, which may reflect a genuine mechanistic basis for the model. This property also allowed the calculation of (a) parameters analogous to the decimal reduction time D and z, the temperature increase needed to change the D value by a factor of 10, in thermal processing, and hence the processing conditions needed to attain a desired level of inactivation; and (b) the apparent thermodynamic volumes of activation associated with the lethal events. The hypothesis that inactivation rates changed as a function of the square root of time would be consistent with a diffusion-limited process.

Influence of Water Temperature on the Growth Rate of the Landlocked Sea Lamprey (Petromyzon marinus) and the Associated Rate of Host Mortality

1977 ◽  
Vol 34 (9) ◽  
pp. 1373-1378 ◽  
Author(s):  
G. J. Farmer ◽  
F. W. H. Beamish ◽  
P. F. Lett
Keyword(s):  
Growth Rate ◽  
Great Lakes ◽  
Water Temperature ◽  
Growth Rates ◽  
Petromyzon Marinus ◽  
Sea Lamprey ◽  
Instantaneous Growth ◽  
Exponential Decline ◽  
Influence Of Water ◽  
Host Mortality

Groups of sea lampreys (Petromyzon marinus) of 10–90 g initial weight were held at temperatures of 1–20 °C for 30 days and allowed to feed ad lib. on white suckers (Catostomus commersoni). Increases in water temperature and in lamprey size caused the rate of host mortality to increase in agreement with observations that mortality in the Great Lakes is seasonal. Instantaneous growth rates were maximal at 20 °C for lampreys of 10–30 g, the optimal temperature for growth shifting to 15 °C for larger lampreys of 30–90 g. Growth rates were intermediate at 10 °C and lowest at 4 °C for lampreys of all size. Accordingly, host mortality increased with temperature over the 4–20 °C range. At all experimental temperatures, increases in lamprey weight were accompanied by an exponential decline in instantaneous growth rates, a phenomenon also observed for teleosts. Laboratory growth rates at temperatures of 5–15 °C were comparable to rates observed for lampreys in Lake Huron between April and November and agree with the observation that lampreys feed in deeper waters between April and June before moving to warmer, shallower waters during the summer when growth rate increases. Key words: sea lamprey, white sucker, host, temperature, growth, Great Lakes, mortality

Some Fracture Mechanics Correlations

1968 ◽  
Vol 10 (4) ◽  
pp. 329-336
Author(s):  
L. P. Pook
Keyword(s):  
Mechanical Properties ◽  
Fracture Mechanics ◽  
Tensile Test ◽  
High Strength Steels ◽  
High Strength ◽  
Gauge Length ◽  
Published Data ◽  
Square Root ◽  
Beryllium Copper ◽  
Reduction Of Area

The results of tests on two high-strength steels, beryllium copper and perspex, together with some published data on high-strength steels were examined to see whether there was any relationship between the fracture mechanics parameter K1C and conventional mechanical properties. It was found that for steels and beryllium copper a correlation appeared to exist between K1C and the zero gauge length strain (= Z/(1 - Z) where Z is the reduction of area measured in a tensile test). It was also found that for constant, K1C was proportional to the square root of Young's modulus. The correlation band for steels was too wide for K1C to be estimated accurately from.

Growth and Development of Pouch Young of Wild and Captive Dasyurus-Geoffroii (Marsupialia, Dasyuridae)

1988 ◽  
Vol 36 (5) ◽  
pp. 533 ◽  
Author(s):  
M Serena ◽  
TR Soderquist
Keyword(s):  
Growth Rates ◽  
Growth And Development ◽  
Head Width ◽  
Square Root ◽  
Crown Rump Length ◽  
Medium Weight

Growth and development of six captive litters of D. geoffroii were monitored at 1-5 day intervals from birth until they were left in dens at about 62-72 days of age. Two neonates were 4.4 mm long and weighed an average 11 mg. By the age of 63 days, juvenile weight had increased 1500-fold, to an average of 16.7 g. Growth of crown-rump length (from 0-40 days) and the square root of head width (from 8-65 days) is linear with respect to time. Wild D. geoffroii were first observed to be left in dens at the age of 62 days, soon after outgrowing the pouch. Wild and captive growth rates appear similar through the first half of pouch life. At older ages, wild litters generally grew more slowly than captive litters; wild litters belonging to thin mothers grew more slowly than litters with medium-weight mothers, which in turn grew more slowly than litters with fat mothers.

scholarly journals The effects of water temperature on the juvenile performance of two tropical damselfishes expatriating to temperate reefs

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Lucas D. Djurichkovic ◽  
Jennifer M. Donelson ◽  
Ashley M. Fowler ◽  
David A. Feary ◽  
David J. Booth
Keyword(s):  
Water Temperature ◽  
Growth Rates ◽  
Global Climate ◽  
Austral Summer ◽  
Reef Fishes ◽  
Performance Parameters ◽  
Feeding Rates ◽  
Lower Growth ◽  
Temperate Reefs ◽  
Eastern Australia

Abstract Ocean warming associated with global climate change is already inducing geographic range shifts of marine species. Juvenile coral reef fishes transported into temperate latitudes (termed ‘vagrant’ fishes) can experience winter water temperatures below their normal thermal minimum. Such environmental extremes may increase energetic costs for such fishes, resulting in reduced performance, which may be the governing factor that limits the potential for poleward range expansion of such fishes. This study compared the juvenile physiological performance and behaviour of two congeneric tropical damselfishes which settle during austral summer months within temperate eastern Australia: Abudefduf vaigiensis have an extended southern range, and lower threshold survival temperature than the congeneric A. whitleyi. Physiological and behavioural performance parameters that may be affected by cooler temperature regimes at higher latitudes were measured in aquaria. Lower water temperature resulted in reduced growth rates, feeding rates, burst escape speed and metabolic rates of both species, with significantly reduced performance (up to six-fold reductions) for fishes reared at 18 °C relative to 22 °C and 26 °C. However, A. whitleyi exhibited lower growth rates than A. vaigiensis across all temperatures, and lower aerobic capacity at the lowest temperature (18 °C). This difference between species in growth and metabolic capacity suggests that the extended southern distribution and greater overwintering success of A. vaigiensis, in comparison to A. whitleyi is related to thermal performance parameters which are critical in maintaining individual health and survival. Our results support previous findings in the region that water temperature below 22 °C represents a critical physiological threshold for tropical Abudefduf species expatriating into temperate south-eastern Australia.

A Conceptual Model for the Estimation of the Sensitivity of Black Fly Larvae to Bacillus thuringiensis var. israelensis

1989 ◽  
Vol 46 (10) ◽  
pp. 1785-1792 ◽  
Author(s):  
Antoine Morin ◽  
Christian Back ◽  
Jacques Boisvert ◽  
Robert H. Peters
Keyword(s):  
Bacillus Thuringiensis ◽  
Feeding Rate ◽  
Standard Procedure ◽  
Dry Mass ◽  
Published Data ◽  
Contact Period ◽  
Larval Feeding ◽  
Feeding Rates ◽  
Black Fly ◽  
Proposed Model

Results from bioassays of a commercial formulation of Bacillus thuringiensis var. israelensis (Teknar HP-D) are combined with an empirical model of the feeding rate of larvae of a target species of black fly (Simulium venustum/verecundum) to develop a model relating the mortality of larvae to the amount of formulation ingested per unit mass of larvae (specific ingested dose). LD50 of Teknar HP-D was about 1 μg wet mass of Teknar per milligram dry mass of larvae, and independent of size of the larvae and seston concentration. Compared with standard assay analysis relating the mortality to the dose (milligrams per litre times seconds), the proposed model allowed more precise and replicable estimation of the effective dose. Reanalysis of published data on the potency of another Bti formulation (Teknar WDC), confirmed the superiority of the proposed model over the standard procedure. Susceptibility of larvae to particulate larvicides is mainly a function of the larval feeding rate. In addition to size of the larvae, temperature, and seston concentration, analysis of the model reveals that the length of the contact period and the variability of feeding rates among individual larvae are important factors determining the mortality rate following treatments.

scholarly journals The demographics and morphometries of biogenic reefs: important considerations in conservation management

2017 ◽  
Vol 98 (6) ◽  
pp. 1231-1240 ◽  
Author(s):  
Jenna M. Brash ◽  
Robert L. Cook ◽  
Clara L. Mackenzie ◽  
William G. Sanderson
Keyword(s):  
Population Structure ◽  
Growth Rates ◽  
Conservation Management ◽  
Tidal Flow ◽  
Growth Curves ◽  
Shell Morphology ◽  
Published Data ◽  
Marine Habitat ◽  
Juvenile Abundance ◽  
Horse Mussel

Modiolus modiolus L. (horse mussel) reefs are a priority marine habitat of high conservation value that is currently listed as endangered and/or threatened across its European distribution. Population structure, density or shell morphology may influence the biodiversity of a reef, either directly or indirectly. Thus, such metrics are important considerations for successful conservation management of these biodiversity hotspots. Population structure, shell morphology and growth rates were examined in M. modiolus reefs across the UK range of the habitat to examine differences between key populations, including those near the Lleyn Peninsula in Wales (southern range), off Port Appin in Western Scotland (mid-range) and in Scapa Flow in the Orkney Isles, Scotland (northern range). Additionally, the influence of physical conditions (temperature and tidal flow) to growth rate and predicted maximum shell length for each population was examined. Growth rates were determined using acetate peels of sectioned shells. Lower juvenile abundance was observed in Scapa Flow. Small, narrow-shaped shells were found to be characteristic of North Lleyn mussels, and larger, globular-shaped shells were characteristic of mussels in Scapa Flow and off Port Appin. Mussels in Scapa Flow were slower growing, yet reached a longer asymptotic length (L∞) than mussels of Port Appin and North Lleyn. Growth curves from sites within this study were analysed with other published data. A trend of higher L∞ at higher latitudes and at lower flow rates was observed. Variations in growth and age are discussed in relation to flow regimes, connectivity to other reefs, density and latitude.

Growth of Esteya vermicola in media amended with nitrogen sources yields conidia with increased predacity and resistance to environmental stress

2011 ◽  
Vol 57 (10) ◽  
pp. 838-843 ◽  
Author(s):  
Zhen Wang ◽  
Chun Yan Wang ◽  
Li Juan Gu ◽  
Yun Bo Wang ◽  
Yong An Zhang ◽  
...  
Keyword(s):  
Environmental Stress ◽  
Ammonium Nitrate ◽  
Significant Influence ◽  
Pine Wilt Disease ◽  
Nitrogen Sources ◽  
Dry Mass ◽  
Bursaphelenchus Xylophilus ◽  
Pinewood Nematode ◽  
Esteya Vermicola ◽  
And Control

Esteya vermicola , an endoparasitic fungus of pinewood nematode, exhibits great potential as a biological agent against nematodes. In this study to enhance the sporulation, predacity, and environmental resistance of E. vermicola, various nitrogen sources, such as glycine, l-leucine, and ammonium nitrate, were tested. The supplement of glycine and l-leucine had a significant influence on the growth rate of the colony, enhancing colony dry mass by 5-fold more than did ammonium nitrate or the control. Of the nitrogen sources tested, ammonium nitrate and l-leucine promoted sporulation, yielding more than 6 × 106 CFU/g, while glycine enhanced the proportion of lunate spores. Meanwhile, the supplement of nitrogen sources had a significant influence on adhesive rate and mortality rate against Bursaphelenchus xylophilus . Moreover, the supplement of glycine enhanced the survival rate against heat stress by more than 3-fold that of l-leucine, ammonium nitrate, and control. The spores produced in media amended with glycine, l-leucine, and ammonium nitrate had slightly but not significantly higher UV resistance and drought resistance than spores produced without nitrogen sources. These results suggested that the addition of glycine resulted in the production of E. vermicola conidia with increased predacity and resistance to environmental stress that may be more suitable for control of pine wilt disease.

scholarly journals Biometrics seeds, emergence and vigor of camu-camu seedlings depending on the seed coat coloring

2015 ◽  
Vol 5 (2) ◽  
pp. 658-664
Author(s):  
Oscar J. Smiderle ◽  
Edvan Alves Chagas ◽  
Aline G. Souza ◽  
Christinny Giselly Barcelar-Lima ◽  
Maria Isabel Garcia Ribeiro ◽  
...  
Keyword(s):  
Dry Matter ◽  
Brazilian Amazon ◽  
Dry Mass ◽  
Fruit Species ◽  
Physiological Quality ◽  
Precision Balance ◽  
Digital Caliper ◽  
Growth Of Seedlings ◽  
Individual Mass

In the Brazilian Amazon is significant diversity of fruit species, the agronomic characteristics of which are still little studied. The objective of this study was to evaluate the influence of tegument coloration on germination and vigor of camu-camu seeds. The seeds were obtained from ripe and healthy fruits coming from population of the Urubu River in Roraima and were classified visually according to the tegument coloration of green, red and brown color. 200 seeds for each class of colors were utilized, evaluating the following biometric characters: length, breadth, thickness and individual mass, obtained with the aid of a digital caliper and precision balance. The experimental design utilized was the completely randomized with three treatments and 10 replications of 20 seeds. The highest means of mass and volume were obtained from brown and red seeds. The brown seeds produce higher content of root dry mass than both the green and red seeds. The physiological quality of camu-camu seeds of the Urubu River is associated with tegument coloration. Seeds with brown tegument have better development, greater growth of seedlings with greater accumulation of dry matter both in the roots and shoots.

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