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Full-Text Articles in Life Sciences

Spatial And Temporal Continuity Of Kangaroo Rat Populations Shown By Sequencing Mitochondrial Dna From Museum Specimens, W. Kelley Thomas, Svante Pääbo, Francis X. Villablanca, Allan C. Wilson Aug 1990

Spatial And Temporal Continuity Of Kangaroo Rat Populations Shown By Sequencing Mitochondrial Dna From Museum Specimens, W. Kelley Thomas, Svante Pääbo, Francis X. Villablanca, Allan C. Wilson

Biological Sciences

The advent of direct sequencing via the polymerase chain reaction (PCR) has opened up the possibility of molecular studies on museum specimens. Here we analyze genetic variation in populations over time by applying PCR to DNA extracted from museum specimens sampled from populations of one species over the last 78 years. Included in this study were 43 museum specimens of the Panamint kangaroo ratDipodomys panamintinus from localities representing each of three geographically distinct subspecies. These specimens were originally collected and prepared as dried skins in 1911, 1917, or 1937. For each specimen, a 225-bp segment of the mitochondrial genome ...


Life History Of Paracantha Gentilis (Diptera: Tephritidae), David H. Headrick, Richard D. Goeden Jul 1990

Life History Of Paracantha Gentilis (Diptera: Tephritidae), David H. Headrick, Richard D. Goeden

Horticulture and Crop Science

The life history of Paracantha gentilis Hering in southern California is described. This stenophagous tephritid reproduces in the capitula of native Cirsium thistles. Courtship and mating behavior are described from field and laboratory observations. Territorial and courtship behavior of males and the morphological characters involved in possible male pheromone emission are described and illustrated, as are the oviposition behavior and reproductive morphology of females. Egg clutch sizes ranged from one to 13 eggs, with a maximum of six clutches per capitulum. Larvae fed gregariously within stage-specific niches. Pupariation occurred in the capitula, from which adults emerged in mid-June through early ...


Cost-Effective Wilderness Fire Management: A Case Study In Southern California, Christian A. Childers, Douglas D. Piirto Mar 1990

Cost-Effective Wilderness Fire Management: A Case Study In Southern California, Christian A. Childers, Douglas D. Piirto

Natural Resources Management and Environmental Sciences

Federal wilderness fire management policies have been scrutinized since the catastrophic fires in the Greater Yellowstone Area in 1988. While wilderness tire management objectives are still aimed at recreating natural fire regimes, all USDA Forest Service fire management programs must be cost-effective. Since current Forest Service economic analyses do not fully represent the value of fire to wilderness, a cost-effectiveness analysis was developed to compare wilderness fire management options. The analytical procedure is briefly reviewed, illustrated through a southern California case study and case study results are discussed. These results suggest that containment of some tires may be more cost-effective ...


Description Of The Immature Stages Of Paracantha Gentilis (Diptera: Tephritidae), David H. Headrick, Richard D. Goeden Mar 1990

Description Of The Immature Stages Of Paracantha Gentilis (Diptera: Tephritidae), David H. Headrick, Richard D. Goeden

Horticulture and Crop Science

Descriptions are provided of the egg, larvae, and puparium of Paracantha gentilis Hering, a native, stenophagous tephritid which infests the capitula of thistles. Detailed examination of larvae led to the discovery of a median oral lobe between the mouth hooks. This is the first structure of this kind described for Tephritidae. Two sensory structures on the anterior lobes of P. gentilis also were discovered, the lateral sensory organ and the pit sensory organ. In comparing the anterior sensory apparatus of P. gentilis larvae with those in Anthomyiidae, Calliphoridae, Drosophilidae, Muscidae, and Syrphidae, striking similarities were apparent. Photographs that illustrate the ...


Prediction Of Zinc Deficiency In Navy Beans (Phaseolus Vulgaris) By Soil And Plant Analyses, J. D. Armour, A. D. Robson, G. S.P. Ritchie Jan 1990

Prediction Of Zinc Deficiency In Navy Beans (Phaseolus Vulgaris) By Soil And Plant Analyses, J. D. Armour, A. D. Robson, G. S.P. Ritchie

Food Science and Nutrition

Navy beans (Phaseolus vulgaris cv. Gallaroy) were grown with 7 rates of zinc (Zn) in a Zn-deficient gravelly sandy loam in a glasshouse experiment. The plant shoots were harvested 31 days after sowing and the Zn concentration in each of 4 plant parts (YL, young leaf; YOL, young open leaf; YFEL, youngest fully expanded leaf; and whole shoots) was related to the fresh weight of the shoots. The critical Zn concentrations (mgtkg) in the plant parts determined by the 2 intersecting straight lines model were 21.1 for YL (r2 = 0.66), 17.1 for YOL (r2 = 0 ...


Iron Fertilization Of Kentucky Bluegrass, David J. Wehner, Jean E. Haley Jan 1990

Iron Fertilization Of Kentucky Bluegrass, David J. Wehner, Jean E. Haley

Office of the Dean (CAFES) Scholarship

Iron applications are sometimes used to enhance the color (darker green) of turfgrass stands even when iron is not deficient. A study was conducted to determine the feasibility of replacing a portion of the total yearly N applied to Kentucky bluegrass (Poa pratensis L.) with iron. Turfgrass response to iron chelate (Sequestrene 330) applications at 2.2 kg Fe ha-1 in combination with three liquid-applied N sources (urea, Formolene, and FLUF) at 25 kg N ha-1 was compared to turf response from applications of the N sources at 49 kg N ha-1. Iron was substituted for part ...


Documented Chromosome Numbers 1990: 1. Miscellaneous North American Vascular Plants, Bruce D. Parfitt, Donald J. Pinkava, Debbie Rickel, Dan Fillipi, Beth Eggers, David J. Keil Jan 1990

Documented Chromosome Numbers 1990: 1. Miscellaneous North American Vascular Plants, Bruce D. Parfitt, Donald J. Pinkava, Debbie Rickel, Dan Fillipi, Beth Eggers, David J. Keil

Biological Sciences

The following meiotic chromosome counts are documented by specimens deposited in Herbarium of Arizona State University (ASU). Previously uncounted taxa are represented by an asterisk (*). A double asterisk (**) indicates a new number for the species.


A Paleontological Review Of Three Billfish Families (Istiophoridae, Xiphiidae, And Xiphiorhynchidae), Harry L. Fierstine Jan 1990

A Paleontological Review Of Three Billfish Families (Istiophoridae, Xiphiidae, And Xiphiorhynchidae), Harry L. Fierstine

Biological Sciences

No abstract provided.


Extractable Zinc In Particle Size Fractions Of Soils From Western Australia And Queensland, J. D. Armour, G. S.P. Ritchie, A. D. Robson Jan 1990

Extractable Zinc In Particle Size Fractions Of Soils From Western Australia And Queensland, J. D. Armour, G. S.P. Ritchie, A. D. Robson

Food Science and Nutrition

The zinc (Zn) content of particle size fractions of 12 mainly Zn deficient soils was measured by extraction with three contrasting extractants. The soils, which ranged from sands to a black earth, were from Western Australia and Queensland and particle size fractions (clay, silt, fine sand, coarse sand) were obtained by sieving and sedimentation after ultrasonification of soil suspended in deionized water. The extractants were concentrated HNO3/H2SO4/HClO4 (acid extractable or AE-Zn), DTPA and 0.002 M CaCl2. For each extractant, Zn contents of the fractions and whole soils were correlated with organic ...


Zinc Adsorption By A Lateritic Soil In The Presence Of Organic Ligands, P. Chairidchai, G. S. P. Ritchie Jan 1990

Zinc Adsorption By A Lateritic Soil In The Presence Of Organic Ligands, P. Chairidchai, G. S. P. Ritchie

Food Science and Nutrition

Zinc adsorption by a lateritic podzolic soil was measured in the presence of 0 to 3 mmol/litre of acetate, oxalate, citrate, tricarballylate, salicylate, or catechol, or 0 to 3 mmolc/litre of humate. Zinc remaining in solution was measured by atomic absorption spectrometry after shaking the soil for 17 h at a soil/liquid ratio of 1:5 in a 0.003 mol/litre KCl solution containing 0 to 500 μmol/litre Zn and the ligands. In the absence of organic ligands, more than 95% of the zinc was adsorbed. The amount of adsorption was linearly correlated with ...