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.

Significance of Organic Detritus in the Diet of Larval Lampreys in the Great Lakes Basin

1994 ◽  
Vol 51 (11) ◽  
pp. 2380-2387 ◽  
Author(s):  
Trent M. Sutton ◽  
Stephen H. Bowen
Keyword(s):  
Great Lakes ◽  
Feeding Rate ◽  
Assimilation Efficiency ◽  
Dry Mass ◽  
Great Lakes Basin ◽  
Organic Detritus ◽  
Upper Peninsula ◽  
Sea Lampreys ◽  
Gut Fullness ◽  
Upper Peninsula Of Michigan

Larval sea lamprey (Petromyzon marinus) and northern brook lamprey (Ichthyomyzon fossor) were collected monthly from three streams in the Upper Peninsula of Michigan from May 1992 through May 1993 and larval sea lampreys were collected during summer months from sites throughout the Great Lakes basin. Organic detritus made up most of the diet ash-free-dry-mass (AFDM) throughout the year, averaging 97.79%, with algae (2.12%) and bacteria (0.09%) making up the remainder of the diet AFDM. Assimilation efficiency for AFDM averaged 72% during warmer months and 53% during cooler months (annual mean = 61%). Gut fullness (amount of AFDM in the anterior one-tenth of the intestine) was low (mean = 0.10 mg diet AFDM∙g−1 ammocoete). There were no significant differences in these measures between ammocoetes collected from the Upper Peninsula and those collected throughout the Great Lakes basin. From a laboratory-determined relationship between gut fullness and feeding rate, feeding rate in the field was estimated to be extremely slow, ranging from 4.2 to 5.5 mg diet AFDM∙g−1 ammocoete∙d−1. These observations indicate that larval lampreys efficiently utilize a diet of organic detritus during warmer months when stream temperatures and food quality are more favorable for feeding, digestion, and growth.

Calculation of 6-Hour Dip Creatinine Ratio from the 4-Hour Peritoneal Equilibration Test. The Effect of Dwell Duration on the Results

1997 ◽  
Vol 17 (3) ◽  
pp. 273-278 ◽  
Author(s):  
Rajnish Mehrotra ◽  
Ramesh Khanna ◽  
Thomas C.K. Yang ◽  
Pranay Kathuria ◽  
Harold L. Moore ◽  
...  
Keyword(s):  
Mathematical Model ◽  
Peritoneal Dialysis ◽  
University Hospital ◽  
Published Data ◽  
Peritoneal Equilibration Test ◽  
Cardiovascular Research ◽  
Proposed Model ◽  
Margin Of Error ◽  
The University ◽  
Exponential Relation

Objectives Since the introduction of the peritoneal equilibration test (PET), the 4-hour dialysatelplasma creatinine (DIP Cr) has been used by several authors for determining continuous ambulatory peritoneal dialysis (CAPD) prescriptions. However, the results have been unsatisfactory because the 4-hr DIP Cr does not accurately reflect the DIP Cr in 24-hr collections. The PET and the 24-hr dialysate collections differ in the duration of dwell and the tonicity and volume of dialysate, all of which influence the equilibrated DIP Cr. It can be assumed that the DIP Cr in 24-hr collections in these patients is closer to a 6-hr DIP Cr. Because a 6hr PET is inconvenient, we developed a mathematical model to calculate the 5 and 6-hr DIP using the results of a standard PET. Design In a retrospective analysis, DIP Cr ratios in 24-hr collections and DIP Cr ratios calculated from a mathematical formula were correlated. Using a mathematical model, the data collected fit an exponential relation of the type DIP = a(1 -e-t/τ). The values of a and τ are unique for a given patient and were determined using a nonlinear regression technique. The formula performed well on our published data -the true and predicted 6-hr DIP Cr being 0.696 and 0.71, respectively. Setting The University Hospital and Clinics, Dalton Cardiovascular Research Center and Dialysis Clinic, Inc., Columbia, Missouri. Patients All CAPD patients on four 2-L exchangeslday at the time of the 24-hr collections were included. Interventions None. Main Outcome Measures Closeness of 4-hr and 6-hr DIP Cr values to those of 24-hr ratios. Results The study group comprised 74 patients (age, mean ± SEM: 56.4 ± 1.8 yr) with 80 PETs and 145 (24-hr) collections. The interval between the two tests was 8. 3 ± 0.9 months (0 48.7 months). The median 24-hr DIP Cr of 0.760 did not differ significantly from the predicted median 6-hr DIP Cr of 0.755. A subgroup analysis, based on transport type, showed that this relationship was most precise in the high-average transporters. The predicted 6hr DIP Cr was within 100;0 of the 24-hr DIP Cr in 48% of patients and within 20% in 77% of patients. The margin of error was greatest in the low transporters. Conclusions To conclude, the 4-hr DIP Cr from a PET cannot be used interchangeably with the DIP Cr in the 24-hr dialysate collections, hence, the clearances calculated thereof will be inaccurate. Using the proposed model, it is feasible to use the 4 -hr PET results to obtain 5 and 6 -hr DIP Cr values. In our study, using this model, the extrapolated 6-hr DIP Cr is similar to the DIP Cr in 24-hr dialysate collections only in the high-average transporters. Hence, the best way to determine clearances in peritoneal dialysis patients is still by collecting 24-hr dialysates.

Comparative Field Energetics of Two Macropod Marsupials and a Ruminant.

1990 ◽  
Vol 17 (6) ◽  
pp. 591 ◽  
Author(s):  
KA Nagy ◽  
GD Sanson ◽  
NK Jacobsen
Keyword(s):  
Feeding Rate ◽  
Energy Content ◽  
Metabolizable Energy ◽  
Ecological Modelling ◽  
Feeding Rates ◽  
Doubly Labelled Water ◽  
Water Influx ◽  
Scaling Relationship ◽  
Field Metabolic Rates ◽  
Free Ranging

Field metabolic rates (FMRs) and water influx rates were measured via the doubly labelled water method in wild Tasmanian pademelons and grey kangaroos living in the Jock Marshall Reserve at Clayton, Victoria, and in wild black-tailed deer free-ranging within a nature reserve at Davis, California. Deer expended more than 3 times more energy per day than similar sized grey kangaroos. Feeding rates required to achieve energy balance were estimated from FMRs along with an estimate of metabolizable energy content of the food. The estimated feeding rates for pademelons and kangaroos were combined with similar values for 5 other species of macropods to calculate an allometric (scaling) relationship for food requirements of macropod marsupials. Feeding rate had the following relationship to body mass: g food (DM) consumed per day = 0.20 g body mass0.79 (r2 = 0.94). The findings reported herein should be useful for predicting the approximate food requirements of free-ranging macropods and deer for purposes of ecological modelling, conservation efforts and management programmes.

Impacts of water temperature on the physiology and behaviours of the sea urchins Heliocidaris crassispina and Mesocentrotus nudus that reflect their range extension and disappearance in the Oga Peninsula, northern Honshu, Japan

2020 ◽  
Author(s):  
Wenping Feng ◽  
Nobuyasu Nakabayashi ◽  
Eri Inomata ◽  
Masakazu N. Aoki ◽  
Yukio Agatsuma
Keyword(s):  
Low Temperature ◽  
Native Species ◽  
Feeding Rate ◽  
Sea Urchins ◽  
Temperature Limit ◽  
Feeding Rates ◽  
Righting Response ◽  
Mesocentrotus Nudus ◽  
Temperature Rate ◽  
High Or Low Temperature

Ocean warming has facilitated the extension of Heliocidaris crassispina to Oga Peninsula, Japan, where the native species Mesocentrotus nudus has disappeared. To verify the temperature impacts on the physiology and behaviour of the two species, we reared small sea urchins at the increasing/decreasing temperature rate of 2.5°C week-1. The righting response, lantern reflex, gonad and gut carbon (C) and nitrogen (N) contents, and feeding rate were investigated. The high and low temperature limits of H. crassispina were 33.3°C and 3.9°C, respectively, which were higher than those of M. nudus. The optimal temperature ranges for behaviour and feeding in H. crassispina were 10.3–31.0°C and 10.3–33.4°C, respectively, which were higher than those in M. nudus. Feeding rates decreased significantly in both species when the temperature approached the high or low temperature limit, but the gut C and N contents of were not greatly affected. At 26–31°C, the feeding rate significantly decreased in M. nudus but not in H. crassispina, which may explain the replacement of M. nudus by H. crassispina in the Oga Peninsula.

Effects of Prey Abundance on the Development of the Spider Agelenopsis potteri (Blackwall) (Araneae: Agelenidae)

1965 ◽  
Vol 97 (2) ◽  
pp. 141-147 ◽  
Author(s):  
A. L. Turnbull
Keyword(s):  
Aedes Aegypti ◽  
Feeding Rate ◽  
Prey Capture ◽  
Prey Abundance ◽  
Feeding Rates ◽  
Live Prey ◽  
Straight Line ◽  
Line Relationship

AbstractAgelenopsis potteri (Blackwall) spiders that were reared from egg to adult on live prey (Aedes aegypti L.) supplied at different daily rates varied in the rate that they were able to capture prey, grow, and attain maturity. Mortality varied inversely with feeding rates, but some spiders matured at each feeding rate. All spiders matured in seven stages regardless of the rate of feeding. Both sexes were mature following the sixth moult. The rate of prey capture declined sharply in the adults. Males matured about four days sooner than females. A straight-line relationship exists between the rate at which prey were captured and the dry weights of the adult spiders. A straight-line relationship was also found between the numbers of prey captured per day and the daily development of the spider.

TiC Reinforced Steel Matrix Composite Layers Produced by Laser Surface Alloying

2008 ◽  
Vol 59 ◽  
pp. 55-61 ◽  
Author(s):  
A. Fernández-Vicente ◽  
G. Castro ◽  
J.L. Arias ◽  
Maria Angeles Montealegre
Keyword(s):  
Wear Resistance ◽  
Feeding Rate ◽  
Laser Surface ◽  
Beam Power ◽  
Powder Injection ◽  
Steel Matrix ◽  
Surface Alloying ◽  
Feeding Rates ◽  
Laser Surface Alloying ◽  
Powder Feeding

In the present work, laser surface alloying of H13 tool steel by using TiC has been performed by means of DHPDL (Direct high power diode laser). Different layers were produced by varying laser beam power and powder feeding rate. Several alloying degrees were obtained depending on the laser parameters employed. Laser surface alloyed layers were analyzed by using optical and scanning electron microscopy. Wear resistance was evaluated through pin-on-disk tests at room temperature. In general, it was observed that dilution of TiC powders into the molten H13 substrate decreased as the powder-feeding rate increased and particles size of the titanium carbide precipitates was larger for the higher feeding rates. Wear measurements showed lower values for the wear resistance coefficient of laser alloying layers produced at higher values of the powder injection (feeding) rate. Analysis of the wear surface track was conducted and the specific contribution of the microstructural features on the wear coefficient was assessed. Thus, it was found that larger particles sizes and particle contents protected the martensitic and dendritic steel matrix from being deeply worn. Lower TiC contents in the alloyed layer gave rise to a higher contribution of the plastic deformation in the wear track.

Comparative Agonistic and Feeding Behavior of Hatchery-Reared and Wild Salmon in Aquaria

1968 ◽  
Vol 25 (1) ◽  
pp. 1-14 ◽  
Author(s):  
Owen C. Fenderson ◽  
W. Harry Everhart ◽  
Kenneth M. Muth
Keyword(s):  
Social Interaction ◽  
Atlantic Salmon ◽  
Feeding Behavior ◽  
Salmo Salar ◽  
Social Dominance ◽  
Food Preference ◽  
Feeding Rate ◽  
Feeding Time ◽  
Feeding Rates ◽  
Wild Salmon

When hatchery-reared and wild landlocked Atlantic salmon (Salmo salar) parr of the same age and size were permitted to compete for social dominance and for food in aquaria, twice as many hatchery salmon attained dominance as wild salmon. Dominant hatchery salmon also showed a higher intensity of aggressiveness than dominant wild salmon, displaying a higher and more variable mean nipping rate. Socially dominant salmon ate more food per fish than subordinates, but there were no statistically significant differences in feeding rate between dominant hatchery and dominant wild salmon, or between subordinate hatchery and subordinate wild salmon.Hatchery salmon displayed lower feeding rates than wild salmon when they were held in separate compartments of an aquarium and compared at three temperatures. This difference in feeding rate probably was not a reflection of differences in adaptation to temperature or food preference, but, rather, was the result of interference with feeding caused by the more intense social interaction among hatchery fish.It is suggested that high levels of aggressiveness may contribute to mortalities of hatchery-reared salmon planted in streams because of loss of feeding time, excessive use of energy, and increased exposure to predators.

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).

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