Life Sciences Commons^™

Life History And Description Of Immature Stages Of Euaresta Stigmatica (Diptera: Tephritidae) On Ambrosia Spp. (Asteraceae) In Southern California, David H. Headrick, Richard D. Goeden, Jeffrey A. Teerink

Horticulture and Crop Science

Euaresta stigmatica Coquillett is bivoltine and nearly monophagous on four native ragweeds, Ambrosia spp. (Asteraceae), in the southwestern United States. In southern California, larvae of the spring (F₁) generation develop singly in and feed on one or both ovules of young fruiting involucres of Ambrosia ilicifolia (Gray) Payne, with a small proportion infesting the staminate involucres. Adults emerge after ≈1 mo, with their reproductive organs immature. The F₂ generation develops in the involucres of fall-blooming Ambrosia acanthicarpa Hooker. The egg is described and illustrated for the first time for any species of Euaresta. First, second, and …

Biology Of The Tao, Matthew D. Sellers

Whittier Scholars Program

Much of this project is merely based on perspective. My perspective, that of the philosophies that I am attempting to highlight, and that of the sources where I am lifting facts from as fast as I can grab them, all go into this work. I feel myself to be somewhat of an editor, quilting together pieces of intuition and data in ways that attempt to unify these perspectives. The essays that follow seek to look at ways in which nature follows the quiet, yielding tenets of the Tao; reciprocally, the Tao Te Ching will be shown to accurately reflect the …

Daughter Cells Of Saccharomyces Cerevisiae From Old Mothers Display A Reduced Life Span, Nicanor Austriaco, Brian K. Kennedy, Leonard Guarente

Biology Faculty Publications

The yeast Saccharomyces cerevisiae typically divides asymmetrically to give a large mother cell and a smaller daughter cell. As mother cells become old, they enlarge and produce daughter cells that are larger than daughters derived from young mother cells. We found that occasional daughter cells were indistinguishable in size from their mothers, giving rise to a symmetric division. The frequency of symmetric divisions became greater as mother cells aged and reached a maximum occurrence of 30% in mothers undergoing their last cell division. Symmetric divisions occurred similarly in rad9 and ste12 mutants. Strikingly, daughters from old mothers, whether they arose …

Denitrification, Nutrient Regeneration And Carbon Mineralization In Sediments Of Galveston Bay, Texas, Usa, Andrew R. Zimmerman, Ronald Benner

Faculty Publications

Rates of benthic denitrification, oxygen consumption and nutrient regeneration were measured during winter, spring and summer in Galveston Bay (Texas, USA) sediments. Denitrification ranged from 0 to 47 µmol N₂ m^-2 h^-1 with maximal rates generally occurring in the summer and the upper estuary. Oxygen consumption rates ranged from 38 µmol O₂ m^-2 h^-1 in the winter to 353 µmol O₂ m^-2 h^-1 in the summer and were correlated with denitrification rates. Variations in bay water temperature accounted for 52 % of the variability associated with denitrification rates whereas only 28% …

The Identification, Distribution, Impacts, Biology And Management Of Noxious Rangeland Weeds, Roger L. Sheley

All U.S. Government Documents (Utah Regional Depository)

This document provides a discussion of the biology and management of exotic rangeland weeds which are a threat to native ecosystems of the western United States. Chapter 1 describes a generalized approach for managing noxious weed infested rangeland, while Chapter 2 focuses on preventing noxious weed invasion. In some cases, noxious weeds readily invade riparian areas, and because of the sensitive nature of these ecosystems Chapter 3 is devoted to riparian weed management. The following 13 chapters describe the identification, origin, history, distribution, potential invasion, impacts, biology and ecology, and management of specific noxious rangeland weeds.

1994 Ieee Computer Society Press Reprint, James W. Brunt

Long Term Ecological Research Network

Effective management of ecological research data can insure the security and accessibility of data that cannot be collected again under the same conditions and plays a key role in every aspect of the research project from experimental design to publication. Commercial relational database management software, developed an adequate solution for long-term scientific data management. An archive file format provides the standard around which a data file management system is implemented. The system works within the parameters of existing components of the operating system software. Data filters and data engines are used to communicate data to and from applications. This paper …

Activity And Distribution Of Attached Bacteria In Chesapeake Bay, Peter Griffith, Fuh-Kwo Shiah, Kathryn Gloersen, Hugh W. Ducklow, Madilyn Fletcher

Faculty Publications

The purpose of this study was to further our understanding of the role of particle-associated bacteria in phytoplankton degradation in the Chesapeake Bay, USA, and to identify environmental parameters that control production by free and particle-associated bacteria. Surface and bottom waters at 10 stations along the length of the Bay were sampled over a 2 yr period. Samples were analyzed for temperature, salinity, chlorophyll, phaeophytin, particulate protein, thymidine incorporation (an estimate of bacterial growth rate), and bacterial total direct counts. Results demonstrated that freeliving bacteria were responsible for most of the total bacterial production, which was correlated with temperature and …

Lter Correspondence & Letters, Jerry F. Franklin

Long Term Ecological Research Network

1st. Letter written by Jerry F. Franklin, chair of LTER Network, addressed to David Greenland of the department of Geography. Franklin extends an invitation to the upcoming Coordinating Committee meeting taking place from October 19-21.

2nd. Letter written by Jerry F. Franklin, chair of LTER Network, addressed to Joshua Greenberg of he College of Forest Resources. Franklin extends an invitation to the upcoming Coordinating Committee meeting taking place from October 19-21.

3rd. Letter written by Jerry F. Franklin, chair of LTER Network, he writes on the significant decisions taken place over the LTER/CC meeting held on April 22-24.

4th. Letter …

Multiple Modes Of Asexual Reproduction By Tropical And Subtropical Sea Star Larvae: An Unusual Adaptation For Genet Dispersal And Survival, William Jaeckle

Scholarship

Sea star larvae (Echinodermata: Asteroidea), collected from the subtropical Northwest Atlantic Ocean, exhibited three distinct modes of asexual reproduction. A number of different bipinnariae and brachiolariae reproduced by paratomous cloning of the posterolateral arms. This morphogenesis was identical to that of larvae assignable to the genus Luidia. A second mode of asexual reproduction involves the autotomization of an anterior portion of the preoral lobe. Primary larvae with preoral lobes of varying sizes and free-swimming preoral lobes of various stages of morphological development were simultaneously collected. The free-swimming preoral lobes developed complete digestive systems and ultimately assumed the form of …

G94-1220 Controlling Ticks, John B. Campbell, Gustave D. Thomas

University of Nebraska-Lincoln Extension: Historical Materials

Identification and control of ticks common to Nebraska.

Ticks are members of the same phylum (Arthropoda) of the animal kingdom as insects, but are in a different class (Arachnida). The main difference is the body of a tick is composed of only two sections while insect bodies have three sections.

There are over 800 species of ticks, 100 of which are important to man and animals because of economic losses or disease transmission. Fortunately in the United States, only about 12 species are economically important because they transmit disease organisms (viral, bacterial, protozoan, and rickettsial) or cause economic losses to …

G94-1208 Managing The Alfalfa Weevil, Stephen D. Danielson, Thomas E. Hunt, Keith J. Jarvi

University of Nebraska-Lincoln Extension: Historical Materials

The identification and life cycle of the alfalfa weevil are discussed along with scouting techniques, economic thresholds, and other integrated pest management tactics.

The alfalfa weevil is the primary insect pest of alfalfa in Nebraska. Management is essential to reduce crop losses, particularly during years when weevil infestation is high. Because there also are years when weevil damage is economically unimportant, it is necessary for growers to become familiar with sampling procedures, management guidelines, and control recommendations so control techniques are not used unnecessarily.

Penetration Of The Pz-Peptide Through The Various Membranes Of The Gastrointestinal Tract, Jyun "Jay" Nakamura

Whittier Scholars Program

The use of the oral drugs dates back to the beginning of recorded time. Since the modern era, doctors and researchers have found the various physiological pathways by which they operate and function. Within the past fifty years, this research has proceeded to the cellular and molecular levels. Researchers have found that the drugs target specific components of the infected cells. These drugs interact by binding to three different types of target molecules. The chemicals target receptors found on extracellular proteins, macromolecules like enzymes, transport molecules, nucleic acids, and membrane lipids. With these new findings, new techniques and equipment have …

Rates Of Energy Consumption And Acquisition By Lecithotrophic Larvae Of Bugula Neritina (Bryozoa: Cheilostomata), William Jaeckle

Scholarship

Lecithotrophic larvae of the cheilostome bryozoan, Bugula neritina (L.), lose metamorphic competence 12 to 24 h after release from the maternal zooid. The high respiration rate of newly released larvae (mean=306.3 pmol O₂ larva^-1 h^-1, range= 149.3 to 466.6, n=18 trials, 22.5 °C) from adults collected at Link Port, Fort Pierce, Florida during the winter/spring of 1990-1991 reflects their active swimming behavior. The average energy con¬tent per larva was 15.24 mJ (range: 13.35 to 20.17 mJ ind^-1, n=5 groups). If all cells have an identical energy content and metabolic rate, then 2 and 20% …

Decomposition Of Senescent Blades Of The Seagrass Halodule Wrightii In A Subtropical Lagoon, Stephen Opsahl, Ronald Benner

Faculty Publications

Senescent blades from the seagrass Halodule wrightii Aschers were suspended in the water column of Laguna Madre (Texas, USA) for a period of 419 d, representing the longest seagrass decomposition study to date. The initial stage of decomposition was characterized by a rapid loss of organic matter (36 % in 24 d) attributed to leaching. A total of 76 % of the organic matter from seagrass tissues was lost by the end of the decomposition period. Of the major bulk constituents measured, neutral sugars were most abundant and accounted for 23 % of the ash-free dry wt of the initial …

Hepatic Lipase Treatment Of Chylomicron Remnants Increases Exposure Of Apolipoprotein E, Dawn L. Brasaemle, Kathleen Cornely-Moss, André Bensadoun

Chemistry & Biochemistry Faculty Publications

The consequences of hepatic lipase treatment of chylomicron remnants were studied. Rats were fed corn oil to induce production and secretion of chylomicrons and were then injected with polyclonal antiserum raised against hepatic lipase to specifically and quantitatively inhibit hepatic lipase activity in vivo. A fraction enriched in chylomicron remnants was isolated from rat plasma by a brief centrifugation step that preferentially isolates triglyceride-rich apolipoprotein (apo) B-48-containing lipoproteins. The chylomicron remnants were then treated with hepatic lipase in vitro, or incubated under identical conditions in the absence of enzyme (control incubations). Hepatic lipase-treated and control chylomicron remnants were isolated by …

Bioremediation: A New Technology Using Inhabitants Of The Soil, Matthew Fields

Mahurin Honors College Capstone Experience/Thesis Projects

Bioremediation is the use of microorganisms to clean the environment contaminated with various pollutants such as chemical wastes and petroleum -based products. The microbes use the pollutants as their carbon source and by doing so the contaminants are broken down. This paper examined the numbers of indigenous microorganisms in soil contaminated with diesel fuel and oil. Contaminant-degrading microbes were isolated and enumerated using phenanthrene in mineral media. The breakdown of phenanthrene was used as an indicator for contaminant degradation. The effects of aeration and the addition of nutrients on bioremediation processes was also studied. Soil samples used in the performed …

G93-1167 Spider Mite Management In Corn And Soybeans, Robert J. Wright, Ronald C. Seymour, Leon G. Higley, John B. Campbell

University of Nebraska-Lincoln Extension: Historical Materials

This NebGuide describes the two common spider mites found in Nebraska corn and soybeans, their natural enemies and management.

Two species of spider mites, the Banks grass mite and twospotted spider mite, commonly feed on Nebraska corn. Banks grass mites (BGM) feed almost exclusively on grasses, including corn and sorghum. Twospotted spider mites (TSM) not only feed on many species of grasses, but also on soybeans, fruit trees and a variety of vegetables and ornamental plants. Although these two species are somewhat similar in appearance, they differ in several biological characteristics and in their susceptibility to pesticides.

Banks grass mites …

Denitrification And Oxygen Consumption In Sediments Of Two South Texas Estuaries, Won Bae Yoon, Ronald Benner

Faculty Publications

Spatial and temporal variations in rates of denitrification and oxygen consumption were measured in sediments of the Nueces and Guadalupe Estuaries in southern Texas, USA. Denitrification rates varied from 4.0 to 71.1 µmol N₂ m^-2 h^-1 in the Nueces Estuary and from 4.6 to 34.7 µmol N₂ m^-2 h^-1 in the Guadalupe Estuary. Denitrification accounted for 29 to 80% of total benthic N flux in the study areas. Oxygen consumption rates ranged from 176 to 818 µmol O₂ m^-2 h^-1 in Nueces Estuary and from 208 to 550 µmol O_{2 …}

Bacterial Numbers And Activity, Microalgal Biomass And Productivity, And Meiofaunal Distribution In Sediments Naturally Contaminated With Biogenic Bromophenols, Charles C. Steward, James L. Pinckney, Yvette Piceno, Charles R. Lovell

Faculty Publications

Sediment cores were collected inside and outside of a bed of a bromophenol-producing marine polychaete, Notomastus lobatus, and examined for impact of the bromophenols on sediment microflora and meiofauna around N. lobatus burrows. No significant differences were found between microbial parameters measured inside and outside of the N. lobatus bed. Integrated 6 cm cores taken adjacent to N. lobatus burrows contained 1.2 x 10⁹ bacteria ml^-1. Cell numbers were similar at control sites within the bed, but away from burrows, and not significantly different from cell numbers (1.0 X 10⁹ cells ml^-1) at a …

Enhanced Bacterioplankton Production And Respiration At Intermediate Salinities In The Mississippi River Plume, Gerardo Chin-Leo, Ronald Benner

Faculty Publications

Bacterial abundance and production (thymidine and leucine incorporation) were measured along a salinity gradient from the Mississippi River (0 %₀) to the open waters of the Gulf of Mexico (36 %₀) during July-August 1990 and February 1991. Bacterial production in surface waters was maximal at intermediate salinities (15 to 30 %₀). Nutrient enrichment experiments suggested that bacterial growth near the outflow of the river was C limited whereas bacteria in plume waters of intermediate salinities were P and N limited. Rates of plankton community oxygen demand measured during winter were also maximal at intermediate …

A Brief Introduction To Aims And Methods For Image Processing Of Electron Micrographs Of Biological Specimens, Murray Stewart

Scanning Microscopy

A common problem with electron micrographs of biological objects is that fine details are usually faint and, moreover, tend to be obscured by background noise from stain and support film. Filtering is a useful way to improve the signal-to-noise ratio and is particularly important when trying to detect small changes (conformational or due to labelling) or when examining frozen hydrated objects, where the statistical definition of the image has been reduced because of the low-dose conditions needed to prevent radiation damage. Filtering can also be used to address the superposition effects that result from the large depth of focus of …

2: "The Mapping Of Chromosome 16", Norman A. Doggett, Raymond L. Stallings, Carl E. Hildebrand, Robert K. Moyzis

Genomics: Past & Future

Human chromosome 16 is the main focus of the mapping efforts at Los Alamos. The large photomicrograph on these opening pages illustrates the starting point for those mapping efforts, the evaluation of our chromosome-16-specific library of cloned fragments. Among the 23 pairs of human chromosomes, one pair, chromosome 16, is identified by fluorescence in-situ hybridization. Thousands of yellow fluorescent probes derived from the clone library have hybridized to both copies of chromosome 16. The high density and uniform coverage of the fluorescent signals were a strong indication that we could use the library to construct a map of overlapping cloned …

White Pine Weevil Response To Oak Overstory Girdling - Results From A 16-Year-Old Study, S.A. Katovich, F.S. Morse

Aspen Bibliography

No abstract provided.

Effects Of Tidal Stage And Sun Angles On Intertidal Benthic Microalgal Productivity, James L. Pinckney, R. G. Zingmark

Faculty Publications

Motile benthic diatoms exhibit rhythmic vertical migrations that are influenced by tidal and light cycles. As a consequence of these periodic migrations, corresponding periodicities in benthic microalgal production should occur. Using oxygen microelectrodes, hourly measurements of microalgal production were obtained from subaerially exposed cores collected from low-intertidal muddy sediments in North Inlet estuary, South Carolina, USA Microalgal productivity at low tide was twice that at high tide (mean difference 52 %) and was significantly correlated with diurnal and tidal periodicities (r² = 0.41; p < 0.0001). Production values ranged from 28.0 to 460.5 µmol O₂ mg chl a^-1 h^-1 and maximum rates were achieved during mid-afternoon low …

Dynamics Of Bacterioplankton Abundance And Production In Seagrass Communities Of A Hypersaline Lagoon, Gerardo Chin-Leo, Ronald Benner

Faculty Publications

The significance of bacterioplankton in the flow of carbon and energy and in trophic dynamics of the upper Laguna Madre, Texas (USA), was estimated by measuring bacterioplankton abundance and production over an 18 mo period and over several diel cycles. Bacterioplankton production was estimated from incorporation rates of thymidine (DNA synthesis) and leucine (protein synthesis). These independent inhces of bacterial growth were generally in agreement and yielded nearly identical annual estimates of bacterial production (25.24 g C m^-2 yr^-1 based on thymidine and 25.12 g C m^-2 yr^-1based on leucine). Assuming a 30 % growth …

Life History And Descriptions Of Immature Stages Of Tephritis Baccharis (Coquillett) On Baccharis Salicifolia (Ruiz & Pavon) Persoon In Southern California (Diptera: Tephritidae), Richard D. Goeden, David H. Headrick

Horticulture and Crop Science

Tephritis baccharis (Coquillett) is bivoltine and monophagous on Baccharis salicifolia(Ruiz & Pavon) Persoon in southern California. The egg, the second and third instar larvae, and puparium are described and illustrated. Eggs are inserted singly into terminal buds of main and axillary branches in late winter or early spring. First instar larvae hatch and tunnel into the pith just basad to the apical bud where they initiate gall formation. Gall and larval growth continue slowly into the fall, when pupation occurs. Most F₁ flies emerge, mate, and after about one week begin oviposition. Some F₁ flies that emerge …

G91-1062 Termites (Revised March 2002), Shripat T. Kamble

University of Nebraska-Lincoln Extension: Historical Materials

This NebGuide provides information on biology and control of subterranean termites.

Termites feed on wood and serve an important function in nature by converting dead trees into organic matter. Unfortunately, the wood in buildings is equally appetizing to termites and they cause serious damage to residential and commercial buildings. Two species of subterranean termites are found in Nebraska and both species have similar habitats.

Electrophysiology, Cell Calcium, And Mechanisms Of Hepatocyte Volume Regulation, Walid E. Khalbuss

Electronic Theses and Dissertations

The electrophysiologic technique (Reuss, L., Proc. Natl. Acad. Sci. USA 82:6014, 1985) was modified to measure changes in steady-state hepatocyte volume during osmotic stress. Hepatocytes in mouse liver slices were loaded with tetramethylammonium ion (TMA$\sp{+}$) during transient exposure of cells to nystatin. Intracellular TMA$\sp{+}$ activity (a$\sp{\rm i}\sb{\rm TMA}$) was measured with TMA$\sp{+}$-sensitive, double-barreled microelectrodes. Loading hepatocytes with TMA$\sp{+}$ did not change their membrane potential (V$\sb{\rm m}$), and under steady-state conditions a$\sp{\rm i}\sb{\rm TMA}$ remained constant over 4 min in single impalements. Hyperosmotic solutions (50, 100, & 150 mM sucrose added to media) and hyposmotic solutions (sucrose in media reduced by …

Fisheries Research Report No 88 - A Synopsis Of The Biology And The Exploitation Of The Australiasian Pilchard, Sardinops Neopilchardus (Steindachner) Part 1: Biology, W. J. Fletcher

Fisheries Research Reports

There have been a large number of studies which relate to the biology and exploitation of the Australian pilchard, Sardinops neopilchardus. Much of the data, however, are located in journals which are hard to obtain, or in unpublished reports, and theses. With the increase in catch of pil­chards, particularly in Western Australia, a collation of all the available knowledge pertaining to pilchards in Australia and New Zealand was desired to help with the planning of future research into the Western Australian stocks of this species. This report contains all the information located on the biology of Sardinops neopilchardus, a companion …

Grasshoppers In Utah: General Biology, Edward W. Evans

All Archived Publications

No abstract provided.