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Articles 1 - 10 of 10
Full-Text Articles in Life Sciences
Diet-Selection Ecology Of Tropically And Temperately Adapted Honey Bees, Robert G. Danka, Richard L. Hellmich, Thomas E. Rinderer, Anita M. Collins
Diet-Selection Ecology Of Tropically And Temperately Adapted Honey Bees, Robert G. Danka, Richard L. Hellmich, Thomas E. Rinderer, Anita M. Collins
Richard L Hellmich
Colonies of tropically adapted (Africanized) honey bees had greater numbers and higher percentages of pollen foragers than did temperately adapted (European) honey bees. European colonies had greater overall foraging activity. The number of pollen gatherers in Africanized nests was greater throughout the daily foraging cycle, and was especially high early in the morning when pollen was most abundant. Africanized colonies fielded more pollen collectors even when levels of stimuli which are known to regulate pollen foraging were altered experimentally. Collectively, the foraging patterns resulted in larger stores of pollen in Africanized honey bee nests, while European bee nests typically had …
Prey Depletion By Odonate Larvae: Combining Evidence From Multiple Field Experiments, Clay L. Pierce, Dan M. Johnson, Thomas H. Martin, Charles N. Watson, Robert E. Bohanan, Philip H. Crowley
Prey Depletion By Odonate Larvae: Combining Evidence From Multiple Field Experiments, Clay L. Pierce, Dan M. Johnson, Thomas H. Martin, Charles N. Watson, Robert E. Bohanan, Philip H. Crowley
Clay L. Pierce
In this paper we re-analyze previously published data regarding the response of several prey populations to manipulation of predaceous larval dragonfly (Insecta: Odonata) densities in four separate field enclosure experiments. Using a computer-intensive "rerandomization" approach to testing hypotheses, we show that the individual experiments were not sufficiently powerful to consistently reject false null hypotheses. Combining the data from three comparable experiments, we can enhance the power associated with such tests. Three prey categories (Trichoptera, Oligochaeta, and large Cladocera), constituting less than one-third of the typical odonate diet, were found to be consistently depleted in enclosures with odonate larvae; but the …
Post-Effect Of Ammonia On Energetics Of Laying Hens At High Temperatures, Hongwei Xin, James A. Deshazer, M. M. Beck
Post-Effect Of Ammonia On Energetics Of Laying Hens At High Temperatures, Hongwei Xin, James A. Deshazer, M. M. Beck
Hongwei Xin
Leghorn layers were monitored for heat loss, feed intake, egg production and respiratory rate at various environmental temperatures (TJ after first being exposed to aerial ammonia (NH3). The initial exposure was to 10 or 60 ppm NH3 at a T, of 25 °C for 30 days to simulate a winter environmental condition in a poultry facility. Hens were then allowed to recover in an environment of 5 ppm of NH3 at a T^ of 22 °C for seven days to simulate a spring environmental condition. Birds were then placed individually in a partitional calorimeter free of NH3 at 25, 29, …
Molecular-Marker-Facilitated Investigations Of Quantitative-Trait Loci In Maize. I. Numbers, Genomic Distribution And Types Of Gene Action, Jonathan F. Wendel, M. D. Edwards, Charles W. Stuber
Molecular-Marker-Facilitated Investigations Of Quantitative-Trait Loci In Maize. I. Numbers, Genomic Distribution And Types Of Gene Action, Jonathan F. Wendel, M. D. Edwards, Charles W. Stuber
Jonathan F. Wendel
Individual genetic factors which underlie variation in quantitative traits of maize were investigated in each of two F 2 populations by examining the mean trait expressions of genotypic classes at each of 17-20 segregating marker loci. It was demonstrated that the trait expression of marker locus classes could be interpreted in terms of genetic behavior at linked quantitative trait loci (QTLs). For each of 82 traits evaluated, QTLs were detected and located to genomic sites. The numbers of detected factors varied according to trait, with the average trait significantly influenced by almost two-thirds of the marked genomic sites. Most of …
Responses Of Africanized Honey Bees Hymenoptera Apidae To Pollination Management Stress, Robert G. Danka, Thomas E. Rinderer, Anita M. Collins, Richard L. Hellmich Ii
Responses Of Africanized Honey Bees Hymenoptera Apidae To Pollination Management Stress, Robert G. Danka, Thomas E. Rinderer, Anita M. Collins, Richard L. Hellmich Ii
Richard L Hellmich
Fifteen Africanized (AHB) and 15 European (EHB) honey bee, Apis mellifera L., colonies were moved to six different crop sites during a 2-mo test in Venezuela. Several problems with AHB suggested that these bees may be difficult to use commerically for pollination. Debilitating reductions of adult populations occurred more frequently among AHB colonies (n = 12) than among EHB colonies (n = 5). In 6 of 11 tests of defensive response, targets were stung more by AHB colonies than by EHB colonies; no differences were found in the five other stinging comparisons. Also during defense tests, AHB colonies typically had …
Differential Drone Production By Africanized And European Honey Bee Colonies, Thomas E. Rinderer, Anita M. Collins, Richard L. Hellmich Ii, Robert G. Danka
Differential Drone Production By Africanized And European Honey Bee Colonies, Thomas E. Rinderer, Anita M. Collins, Richard L. Hellmich Ii, Robert G. Danka
Richard L Hellmich
The numbers of mature drones leaving colonies of Africanized and European honey bees were counted after they had been trapped at colony entrances. Two apiaries, each with 10 European and 10 Africanized colonies, were trapped for drones exiting individual colonies on 3 separate days at two week intervals. Africanized colonies maintained far more drones and far more Africanized drones parasitized European colonies than vice versa. These two factors resulted in 91% of the drones leaving colonies in the apiaries being Africanized.
Fish Acute Toxicity Syndromes And Their Use In The Qsar Approach To Hazard Assessment, Steven P. Bradbury, James M. Mckim, Gerald J. Niemi
Fish Acute Toxicity Syndromes And Their Use In The Qsar Approach To Hazard Assessment, Steven P. Bradbury, James M. Mckim, Gerald J. Niemi
Steven P. Bradbury
Implementation of the Toxic Substances Control Act of 1977 creates the need to reliably establish testing priorities because laboratory resources are limited and the number of industrial chemicals requiring evaluation is overwhelming. The use of quantitative structure activity relationship (QSAR) models as rapid and predictive screening tools to select more potentially hazardous chemicals for in-depth laboratory evaluation has been proposed. Further implementation and refinement of quantitative structure-toxicity relationships in aquatic toxicology and hazard assessment requires the development of a "mode-of-action" database. With such a database, a qualitative structure-activity relationship can be formulated to assign the proper mode of action, and …
Physiological Response Of Rainbow Trout (Salmo Gairdneri) To Acute Fenvalerate Lntoxication, Steven P. Bradbury, James M. Mckim, Joel R. Coats
Physiological Response Of Rainbow Trout (Salmo Gairdneri) To Acute Fenvalerate Lntoxication, Steven P. Bradbury, James M. Mckim, Joel R. Coats
Steven P. Bradbury
The physiological responses of rainbow trout (Salmo gairdneri) to fenvalerate intoxication during aqueous exposure were examined to provide information about the pyrethroid mode of action in fish. Trout (n = 4) were exposed to 412 ± 50 μg/liter fenvalerate and died in 10.9 ± 1.5 hr. Brain, liver, and carcass fenvalerate concentrations associated with mortality were 0.16 ± 0.05, 3.62 ± 0.57, and 0.25 ± 0.05 mg/kg, respectively. Visible signs of intoxication included elevated cough rate, tremors, and seizures. Histopathological examination of gill tissue showed damage consistent with irritation. An evaluation of respiratory-cardiovascular and blood chemistry responses indicated an elevated …
Improved Simple Techniques For Identifying Africanized And European Honey Bees, Thomas E. Rinderer, H. Allen Sylvester, Steven M. Buco, Vicki A. Lancaster, Elton W. Herbert, Anita M. Collins, Richard L. Hellmich Ii
Improved Simple Techniques For Identifying Africanized And European Honey Bees, Thomas E. Rinderer, H. Allen Sylvester, Steven M. Buco, Vicki A. Lancaster, Elton W. Herbert, Anita M. Collins, Richard L. Hellmich Ii
Richard L Hellmich
Eight simple techniques based on discriminant statistical procedures are presented to identify Africanized and European bees in the Americas. These techniques arc based on measurements of forewing lengths, the wet and dry weights of degastered bees, and femur lengths. Improved methodologies and statistical procedures result in many more correct identifications at high probabilities of class membership.
Forage Quality Of Perennial Glandular-Haired And Eglandular Medicago Populations, Andrew W. Lenssen
Forage Quality Of Perennial Glandular-Haired And Eglandular Medicago Populations, Andrew W. Lenssen
Andrew W. Lenssen
No abstract provided.