Life Sciences Commons^™

Trypanosoma Lewisi: Effects Of Trace Metal Contaminants On Immunological Responses, Yvonne Hogan, Clarence Lee

Clarence Lee

Possible Selective Advantage Of Anopheles Spp. (Diptera: Culicidae) With The Oxidase- And Acetylcholinesterase-Based Insecticide Resistance Genes After Exposure To Organophosphates Or An Insect Growth Regulator In Sri Lankan Rice Fields, J. Hemingway, Bryony C. Bonning, K. G. I. Jayawardena, I. S. Weerasinghe, P. R. J. Herath, H. Oouchi

Bryony C. Bonning

Treatment of rice fields in Sri Lanka with monocrotophos at 10 mg/litre or pirimiphos-methyl at 0·1 mg/litre gave a selective advantage to larvae of Anopheles subpictus Grassi and A. nigerrimus Giles carrying the oxidase- and acetylcholinesterase-based resistance genes, respectively. However, this selective advantage was apparent for less than ten days after spraying. There was no mortality of any larval instar with monocrotophos 12 days after spraying, and no fourth-instar larval mortality with pirimiphos-methyl 17 days after spraying. The chemical degredation curves for these compounds indicated that this short duration of efficacy was due to the instability of the compounds in …

Kinematics And Estimated Thrust Production Of Swimming Harp And Ringed Seals, Frank E. Fish, S Innes, K Ronald

Frank E. Fish

No abstract provided.

Https://Greentheorygarcinia.Com/Urogenx/, Lud Ivu

lud ivu

Https://Www.Solutionfact.Com/Forskolin-Keto-Cycle/, Bivit Ocur

bivit ocur

Oral Contraceptives And Fat Patterning In Young Adult Women, Ruth E. Litchfield, Katharine K. Grunewald

Ruth E. Litchfield

. Ninety white nulliparous young women (18-26 years of age) participated in a double-blind study designed to compare fat patterning and other physical measurements in oral contraceptive (OCA) users and non- users. Oral contraceptive users (N = 30) and non-users (N = 60) were matched on a 1:2 basis for height and weight. The OCA users and non- users had similar circumference and skinfold measurements, except that OCA users had larger axilla skinfold measurements. Progestational activity of the oral contraceptives was not associated with any measurements taken. However, estrogenic activity was positively correlated with measured body weight, body mass index, …

Photoperiod Effects On 2n Pollen Production, Response To Anther Culture, And Net Photosynthesis Of A Diplandrous Clone Of Solanum Phureja, Henry Owen, R. Veilleux, F. Haynes, K. Haynes

Henry R. Owen

Flow-cytometric analysis of pollen samples obtained from Solanum phureja, clone PP5, grown under 10, 14, and 18 hour photoperiods at the Southeastern Plant Environment Laboratories of North Carolina State University yielded two populations of pollen based on size parameters. These populations corresponded to pollen separation based on propidium iodide staining of DNA. Anther culture response from plants grown under 14 and 18 hour photo periods for 8, I 0, 12, and 14 weeks was greatest from 8 week old plants grown under a 14 hour photoperiod. Net photosynthesis was significantly higher for plants grown under a 10 hour photoperiod than …

Environmental, Genotypic, And Ploidy Effects On Endopolyploidization Within A Genotype Of Solanum Phureja And Its Derivatives, Henry R. Owen, R. E. Veilleux, D. Levy, D. L. Ochs

Henry R. Owen

Flow-cytometric analyses of DNA content were performed on chopped in vivo, in vitro, and protoplast-derived in vitro nuclei of Solanum phureja. An anther-derived monoploid genotype and a diploid and tetraploid clone, derived from callus culture of the monoploid genotype, were used to characterize the influence of in vivo and in vitro environment and explant ploidy level on the extent of endopolyploidization. In addition, protoplast-derived nuclei, from nine anther-derived monoploid genotypes, were examined for genotypic influences on endopolyploidization. DNA distributions of the anther-derived monoploid and callus-derived clones in vivo contained peaks corresponding to 1C, 2C, and 4C DNA levels. By comparison, …

Variability For Critical Photoperiod For Tuberization And Tuber Yield Among Monoploid, Anther-Derived Genotypes Of Solanum Phureja, Henry R. Owen, R. E. Veilleux, F. L. Haynes, K. G. Haynes

Henry R. Owen

Monoploid genotypes (2n = x = 12), derived by anther culture of a diplandrous (2n pollen-producing) clone of Solanum phureja Juz. & Buk., a South American diploid potato species, were examined for their use in germplasm development. Nine monoploid genotypes and the anther-donor genotype were grown in three chambers (10-, 14-, and 18-hr daylengths) to examine the effect of photoperiod on tuber yield and to determine the variability for critical photoperiod for tuberization. Significant differences were found among the monoploid genotypes for tuber weight and tuber number. Longer photoperiod treatments decreased and delayed tuberization. Axillary tuber formation from single-node cuttings …

A Model For Evaluating Time Constraints On Short-Term Reproductive Success In Altricial Birds1, Larry Clark

Larry Clark

We develop a simple single dimension model incorporating the time and energy commitments of breeding altricial birds in an effort to understand the evolutionary constraints on parental care. We chose time as the dimension of preference, because it is a naturally bounded constraint, e.g., length of day or breeding season. The utility of the model was evaluated by comparing simulations of time allocation of various breeding scenarios for the European starling (Sturnus vulgaris) to field data. The structure of the model may prove useful in determining the evolutionary constraints on parental care imposed by the developmental pattern of chicks.

Effect Of Biologically Active Plants Used As Netst Material And The Derived Benefit To Starling Nestlings, Larry Clark, J. R. Mason

Larry Clark

The European starling Sturnus vulgaris preferentially incorporates fresh sprigs of particular plant species for use as nesting material. Chemicals found in these plants may act to reduce pathogen and ectoparasite populations normally found in nest environments. The present experiments were performed to test this Nest Protection Hypothesis. In the fild, we experimentally determined that wild carrot Daucus carota, a plant species preferred as nest material, effectively reduced the number of hematophagous mites found within nests relative to control nests without green vegetation. Chicks from nests containing wild carrot had higher levels of blood hemoglobin than chicks from control nests. However, …

Truncation Of Screwworm (Diptera: Calliphoridae) Development By Irradiation Of Embryos., David B. Taylor, Robert L. Mangan

David B Taylor

Gamma irradiation of screwworm, Cochliomyia hominivorax (Coquerel), embryos was used to truncate the life cycle at the prepupal stage. Egg hatch and larval survival were not reduced by dosages ≤8 kilorads (kr). Pupariation and adult emergence were inhibited by dosages ≥2.8 and 1.2 kr, respectively. Larvae, irradiated as embryos with dosages ≤8 kr, successfully infested wounded sheep, although larval weight was lower than normal. A dosage of 5.8 kr was sufficient to prevent pupariation, while permitting larval development to the third instar. Truncation of screwworm development permits the use of artificially wounded and infested animals for screwworm population surveillance and …

A Pesquisa Urbana No Equador, Fernando Carrión Mena

Fernando Carrión Mena

É relativamente difícil precisar a origem cronológica de um campo ou área de conhecimento de um país determinado. Ainda mais se tem em conta que tanto a constituição teórica de um campo de conhecimento ultrapassa as fronteiras nacionais, como o objeto empírico de estudo é anterior a sua constitui9ao teórica. Isto é, precede-a e é uma condição necessária porém insuficiente. Para o nosso caso, este objeto é a "cidade", que historicamente existe no Equador, segundo algumas hipóteses desde á conquistam espanhola (Carrión, F. 1986); no entanto um pensamento relativamente consistente sobre ela recém se inicia quando o processo de urbanização …

Comparative Rates Of Recruitment To Pollen Sources By Africanized And European Honey Bees (Apis Mellifera L.), Robert G. Danka, Anita M. Collins, Thomas E. Rinderer, Richard L. Hellmich Ii

Richard L Hellmich

The use of recruitment by Africanized and European honey bee pollen foragers was studied. Comparisons were made of rate of initiation, duration, and tempo of recruitment dances, the number of recruits following dancers, and number of pollen sources visited. Rate of recruitment (the product of rate of dance initiation and number of followers per dancer) to pollen sources was higher in European colonies, due mostly to a higher rate of dance initiation in European colonies. Dance tempo was faster for Africanized foragers. Duration of dances and number of resources used were each similar for the two bee types.

Influencing Matings Of European Honey Bee Queens In Areas With Africanized Honey Bees (Hymenoptera: Apidae), Richard L. Hellmich Ii, Anita M. Collins, Robert G. Danka, Thomas E. Rinderer

Richard L Hellmich

Manipulation of the honey bee (Apis mellifera L.) drone population near a mating apiary was investigated as a method for increasing the frequency of European drones that mate with European queens in an area of Africanized honey bees. Thirty percent of the matings were controlled with only four European drone source colonies, and 40% were controlled with seven colonies. If queen producers can tolerate low levels of mismating, they may not have to drastically alter their management practices.

In Vitro Dry Matter Disappearance, Crude Protein Concentration, And Leaf Percentage Of Erect Glandular-Haired Medicago Populations, Andrew W. Lenssen, E. L. Sorensen, G. L. Posler, L. H. Harbers

Andrew W. Lenssen

Available resistance in alfalfa (Medicago sativa L.) cultivars is currently inadequate to control the alfalfa weevil, Hypera postica (Gyllenha), or potato Ieafhopper, ErnpoascaJabae (Harris), the two most injurious arthropod pests of alfalfa in North America. Resistance to both insects has been documented in other Medicago species having erect, glandular hairs. These hairs have been transferred to alfalfa. A field trial in 1985 was to determine the effects of erect, glandular hairs and their exudates on forage quality of several perennial Medicagos. Glandular and eglandular plant populations were selected from each of the diploids, M. prostrata Jacq. and M. glandulosa David., …

Microhabitat Analyses Of Silurian Stromatoporoids As Substrata For Epibionts, M. T. Segars, W. D. Liddell

W. David Liddell

No abstract provided.

Hydrogen Concentrations As An Indicator Of The Predominant Terminal Electron-Accepting Reactions In Aquatic Sediments, Derek Lovley, Steve Goodwin

Derek Lovley

No abstract provided.

Art, Science, Areté, Neil Greenberg

Neil Greenberg

No abstract provided.

Dna And Morphology: Comparisons In The Onagraceae, Kenneth J. Sytsma, James F. Smith

James F. Smith

Comparisons of systematic information generated from both classical systematic approaches and from DNA analysis at a number of taxonomic levels in the Onagraceae are presented. Phylogenetic results from chloroplast DNA restriction fragment analysis is in Clarkia sect. Syrnpherica (= Peripetasma) are not entirely congruent with results from morphology , but are congruent with distribution of duplications of isozyme-coding loci. Chloroplast DNA and nuclear rDNA evidence for the origin of the monotypic genus Heterogaura from within the genus Clarkia is discussed with respect to morphological divergence between the two genera. Detailed chloroplast DNA restriction site mapping within the seven diploid sections …

Incorporation Of A Product Of Mevalonic Acid Metabolism Into Proteins Of Chinese Hamster Ovary Nuclei, Michael Sinensky, L. A. Beck, T. Hosick

Michael Sinensky

We have examined the nuclear localization of isoprenylated proteins in CHO-K1 cells labeled with [14C]mevalonate. Nuclear proteins of 68, 70, and 74 kD, posttranslationally modified by an isoprenoid, are also components of a nuclear matrix-intermediate filament preparation from CHO cells. Furthermore, the 68-, 70-, and 74-kD isoprenylated polypeptides are immunoprecipitated from cell extracts with two different anti-lamin antisera. Based on exact two-dimensional comigration with lamin B, both from rat liver lamin and CHO nuclear matrix-intermediate filament preparations, and its immunoprecipitation with anti-lamin antisera, we conclude that the 68-kD isoprenylated protein found in nuclei from [14C]mevalonate-labeled CHO cells is lamin B. …

Hard Substrata Community Patterns, 1-120m, North Jamaica, W. D. Liddell, S. L. Ohlhorst

W. David Liddell

No abstract provided.

The Genera Of Bambusoideae (Gramineae) In The Southeastern United States, Gordon C. Tucker

Gordon C. Tucker

No abstract provided.

Genetic Distance And Hybridization Of Black Ducks And Mallards: A Morph Of A Different Color?, G. R. Hepp, James M. Novak, K. T. Scribner, P. W. Stangel

James M. Novak

No abstract provided.

Influx, Net Flux And Transepithelial Flux Of Amino Acids In The Hardshell Clam Mercenaria Mercenaria (Linne): Influence Of Salinity, Michael Rice, Grover Stephens

Michael A Rice

1.1. The effects of salinity on the uptake and internal distribution of alanine and other free amino acids (FAA) in hardsell clams, Mercenaria, was studied by radiochemical and high performance liquid chromatography (HPLC) techniques.2.2. Exposure of animals to reduced salinity does not alter the rate of unidirectional alanine influx.3.3. In 34%o salinity, entry of labeled alanine reflects the net flux of the amino acid. However, in 17%o salinity, there is a net loss of alanine and other acids, mainly taurine, to the medium.4.4. Reduced salinity induces greater incorporation of radiolabeled FAA into macromolecular fractions throughout the animal.5.5. The major factors …

Insect Damage To Conelets, Second-Year Cones, And Seeds Of Ponderosa Pine In Southeastern Nebraska, Judith Pasek, Mary Dix

Judith E Pasek

Rhyacionia spp. and Retinia metallica (Busck) annually caused conelet losses of 8.2% and 5.4%, respectively. Abortion and disappearance of conelets caused by Leptoglossus occidentalis Heidemann or physiological dysfunction averaged 65.7% and were reduced by 13% when conelets were protected with screen cages. Survival of conelets averaged 19.5%. Of those remaining, 76.8% appeared healthy after the second growing season. Dioryctria spp. annually damaged an average of 14.2% of the second-year cones. Mean annual seed potentials ranged from 77.4 to 127.1 seeds per cone, but mean annual seed yields ranged from only 0.4 to 8.1 filled seeds per cone. Caging cones to …

Hybridization Of Aedes (Protomacleaya) Zoosophus With Ae. (Pro.) Triseriatus Group Species: Hybrid Morphology, David Taylor

David B. Taylor

Morphology of hybrids between Aedes (Protomacleaya) zoosophus and Ae. (Pro.) triseriatus group species is described. Adult females of hybrids key to Ae. zoosophus. Hybrids are differentiated from Ae. zoosophus by the dark longitudinal medial or submedial lines on the thorax and by the reduced width of the light tarsal and abdominal bands. The transverse band of light scales on the anterior scutum is complete in Ae. hendersoni / Ae. zoosophus hybrids and incomplete in Ae. triseriatus / Ae. zoosophus hybrids. Aedes brelandi / Ae. zoosophus hybrids are similar to Ae. hendersoni / Ae. zoosophus hybrids. However, due to the …

Truncation Of Screwworm (Diptera: Calliphoridae) Development By Irradiation Of Embryos., David Taylor, Robert Mangan

David B. Taylor

Gamma irradiation of screwworm, Cochliomyia hominivorax (Coquerel), embryos was used to truncate the life cycle at the prepupal stage. Egg hatch and larval survival were not reduced by dosages ≤8 kilorads (kr). Pupariation and adult emergence were inhibited by dosages ≥2.8 and 1.2 kr, respectively. Larvae, irradiated as embryos with dosages ≤8 kr, successfully infested wounded sheep, although larval weight was lower than normal. A dosage of 5.8 kr was sufficient to prevent pupariation, while permitting larval development to the third instar. Truncation of screwworm development permits the use of artificially wounded and infested animals for screwworm population surveillance and …

Influx And Transepithelial Flux Of Amino Acids In The Mussel, Mytilus Edulis., Michael A. Rice, Grover C. Stephens

Michael A Rice

The uptake of amino acids by the non-gill epithelia of the mantle cavity of Mytilus edulis L. was studied and compared with uptake by the gills. Amino acid entry rates and the subsequent distribution of amino acids to the other tissues of the animals were studied using high-performance liquid chromatography and radiochemical techniques. Uptake via the non-gill epithelia lining the mantle cavity was separated from uptake via the gill by employing a preparation in which the gills were surgically removed. Amino acid uptake by such animals was compared with that of suitably sham-operated controls. In short-term experiments (up to 2h), …

Propagation Of Adherent Bacteria On The Brittlestar Ophionereis Annulata (Le Conte) After Enrichment Of Seawater With Amino Acids, Michael A. Rice

Michael A Rice

Epidermal surfaces of the ophiouroid Ophionereis annulata (Le Conte) were examined by scanning electron microscopy. Microvilli, which are characteristic of many transport epithelia, are present on the epidermal surfaces. Epidermal surfaces of freshly-collected brittlestars were compared with brittlestars that were maintained in the laboratory for 48 hours in fresh seawater and in seawater enriched with 20uM glycine. Very few bacteria were observed on the surface of the freshly-collected animals or on animals maintained in the laboratory in fresh seawater. The epidermal surfaces of animals maintained in seawater enriched with 20 uM glycine showed extensive mats of coccoid and bacilloid bacteria. …