Life Sciences Commons^™

The Impact Of Resident And Transient Predators On The Popultation Dynamics Of Juvenile Caribbean Spiny Lobster (Panulirus Argus) In Florida Bay, Florida, Jason Edward Schratwieser

Biological Sciences Theses & Dissertations

There has been a considerable amount of research devoted to exploring the relationship between predators and prey, but many of these studies fail to address how predation can vary over spatial and temporal scales. The tendency of ecologists to model predation as a static entity often masks its capacity for creating distinctive effects in prey populations and communities. Most predation studies also focus on the effect of a single species of predator on a prey population, an unrealistic situation in nature. In the Florida Keys, juvenile spiny lobsters are subjected to two general classes of predators: i) "resident" predators such …

Infochemicals In Mosquito Host Selection: Human Skin Microflora And Plasmodium Parasites, Marieta A.H. Braks, Robert A. Anderson, Bart G.J. Knols

All Peer-Reviewed Publications

The interaction between the African malaria vector Anopheles gambiae and its human host has traditionally been viewed within a bitrophic context, considering only the human and the mosquito. Recently, the influence of the Plasmodium parasite on the interaction has been recognized, because it affects the physiology and/or behaviour of humans and mosquitoes. However, studies on odour-mediated host-seeking behaviour of An. gambiae and other Diptera have provided evidence that a fourth group of organisms should be taken into consideration. Human skin microflora play a role in the production of odorous compounds that might function as kairomones for mosquitoes. Here, Marieta Braks, …

A Study On The Effects Of The N-Terminal Amino Acid Sequence On The Activation Of Human T-Cell Leukemia Virus Type 1 Protease, Hidayah Muhammad Kendall

Chemistry & Biochemistry Theses & Dissertations

Human T-cell leukemia virus type 1 (HTL V-1) is dependent upon the enzymatic activity of its protease for maturation. Maturation of the protease is facilitated by cleavage of specific amino acid residues, followed by dimerization. The effects of the amino acid sequence located N-terminally to the cleavage site on the ability of the protease to become active were the focus of the current study. These amino acid sequences were contributed by the plasmid vector into which the protease gene was inserted.

Surface probability analyses (SPAs) of the vectors, as well as for native sequences which produce the mature protease and …

A Study Of The Seasonal Composition And Abundance Of Phytoplankton And Autotrophic Picoplankton In A Brackish Water Lake In Portsmouth Virginia, Jennifer Leigh Wolny

Biological Sciences Theses & Dissertations

The phytoplankton and autotrophic picoplankton populations of Hoffler Lake, a brackish-water lake in Portsmouth, Virginia, were monitored from May 1997 through May 1998, Analyses of the phytoplankton community using the Utennohl method showed a dominance of Chlorophytes (61-88% of the total abundance) throughout the year, including a winter bloom of Chlamydomonas snowii (maximum concentration of 2.5 x 101 cells/L). Subdominants were Cyanobacteria (10-33% of the total abundance) whose composition included several species of Anabaena, Lyngbya, and a fall bloom of Microcoleus sp. Diatoms, dinoflagellates, and cryptophytes played a secondary role in the phytoplankton community of Hoffler Lake. …

Lymphotropic Virions Affect Chemokine Receptor-Mediated Neural Signaling And Apoptosis: Implications For Human Immunodeficiency Virus Type 1-Associated Dementia, Jialin Zheng, Anuja Ghorpade, Douglas Niemann, Robin L. Cotter, Michael R. Thylin, Leon Epstein, Jennifer Swartz, Robin B. Shepard, Xiaojuan Liu, Adeline Nukuna, Howard E. Gendelman

Nebraska Center for Virology: Faculty Publications

Chemokine receptors pivotal for human immunodeficiency virus type 1 (HIV-1) infection in lymphocytes and macrophages (CCR3, CCR5, and CXCR4) are expressed on neural cells (microglia, astrocytes, and/or neurons). It is these cells which are damaged during progressive HIV-1 infection of the central nervous system. We theorize that viral coreceptors could effect neural cell damage during HIV-1-associated dementia (HAD) without simultaneously affecting viral replication. To these ends, we studied the ability of diverse viral strains to affect intracellular signaling and apoptosis of neurons, astrocytes, and monocyte-derived macrophages. Inhibition of cyclic AMP, activation of inositol 1,4,5-trisphosphate, and apoptosis were induced by diverse …

Cross-Transmission Studies With Eimeria Arizonensis, E. Arizonensis-Like Oocysts And Eimeria Langebarteli: Host Specificity At The Genus And Species Level Within The Muridae, John A. Hnida, Donald Duszynski

Harold W. Manter Laboratory of Parasitology: Faculty Publications

Cross-transmission experiments were done using sporulated oocysts of Eimeria arizonensis from Peromyscus truei and Peromyscus maniculatus, and oocysts of 2 putative species that resemble E. arizonensis, i.e., Eimeria albigulae from Neotoma albigula, and Eimeria onychomysis from Onychomys leucogaster. Oocysts of each species were inoculated into representatives of P. maniculatus and the latter 2 rodent species. Other experiments were conducted wherein oocysts of Eimeria langebarteli from Peromyscus leucopus were given to P. truei and P. maniculatus. Oocysts of E. arizonensis from P. truei and P. maniculatus could be transmitted only to P. maniculatus; likewise, …

Review Of A Classification Of North American Biotic Communities By David E. Brown, Frank Reichenbacher, Susan E. Franson, Robert B. Kaul

Great Plains Research: A Journal of Natural and Social Sciences (through 2013)

This is the latest of many efforts over the past century to classify North America's natural, undisturbed biological communities as they existed in pre-agrarian times and in many places continue to exist today. Its authors' stated objective is to integrate existing works into a hierarchical synthesis that can lead to a standardized system for researchers, land managers, conservation groups, and government agencies. To that end, the authors have modified and expanded David Brown's earlier classification for the Southwest to cover the continent, defined here as the area from the Panama Canal to the Arctic, including Greenland and some of the …

Final Technical Report For The Enhancement Of Autonomous Marine Vehicle Testing In The South Florida Testing Facility Range, South Florida Ocean Measurement Center (Sfomc) Partners

Marine & Environmental Sciences Faculty Reports

The purpose of this grant was to carry out the six scientific experiments on the South Florida Testing Facility (SFTF) Range. In addition to the enhancements to the range, work was performed on all six with some being successfully completed while research continues on the long term tasks.

Cropshare Lease Arrangements For Intensive Dryland Cropping Systems, Paul A. Burgener

Cornhusker Economics

Changes in U.S. agricultural policy implemented following the 1996 Farm Act have allowed producers to consider different cropping systems without restrictions on farm program payment eligibility. As a result, planting decisions have been shifting in response to market prices, conservation compliance and production goals. Some dryland crop producers are using more intensive dryland crop rotations to potentially increase farm income levels. In the past three years, Western Nebraska has seen a decrease in the number of acres planted to wheat, and an increase in the number of acres planted to sunflowers, proso millet, dryland corn and other specialty crops.

Tissue Polyunsaturated Fatty Acids And A Digestive Phospholipase A 3 In The Primary Screwworm, Cochliomyia Hominivorax, A.R. Nor Aliza, R.L. Rana, Steven R. Skoda, Dennis R. Berkebile, David W. Stanley

Department of Entomology: Faculty Publications

We report on the presence of arachidonic acid in larval and adult tissues of the primary screwworm, Cochliomyia hominivorax and of the secondary screwworm, C. macellaria. Arachidonic acid is present in the phospholipids of whole animal extracts of both species. This fatty acid appears to be accumulated during the larval stages, because proportions of arachidonic acid were higher in adults than in larvae. These insects probably obtain the arachidonic acid from dietary phospholipids. We also report on a phospholipase A2 activity in midgut preparations from third instars of the primary screwworm. Phospholipase A2 is responsible for hydrolyzing fatty acids …

Take Time To Listen, Deb Rood

Cornhusker Economics

Harvest is one of those times when it抯 the best and worst of times on a family farm. The anticipation of harvesting your crops is always a highlight for families, the stress of actually getting it done can be overwhelming. One of the things family members can do to make harvest less stressful is to take time to listen to each other. Good communication between family members can make harvest one of the best times. Especially if you know exactly what part you need for the combine. Here are a few tips to help you become a better listener:

Trace Gas Emissions From Laboratory Biomass Fires Measured By Open-Path Fourier Transform Infrared Spectroscopy: Fires In Grass And Surface Fuels, Jon G. Goode, Robert J. Yokelson, Ronald A. Susott, Darold E. Ward

Chemistry and Biochemistry Faculty Publications

The trace gas emissions from six biomass fires, including three grass fires, were measured using a Fourier transform infrared (FTIR) spectrometer coupled to an open-path, multipass cell (OP-FTIR). The quantified emissions consisted of carbon dioxide, nitric oxide, water vapor, carbon monoxide, methane, ammonia, ethylene, acetylene, isobutene, methanol, acetic acid, formic acid, formaldehyde, and hydroxyacetaldehyde. By including grass fires in this study we have now measured smoke composition from fires in each major vegetation class. The emission ratios of the oxygenated compounds, formaldehyde, methanol, and acetic acid, were 1–2% of CO in the grass fires, similar to our other laboratory and …

Cropwatch No. 99-22, Sept. 17, 1999, Lisa Brown Jasa

Crop Watch (1994–2005)

Inside

Grain handling info………..194

Marketing program sites………..195

Killing alfalfa………..196

Last cutting of alfalfa………..196

Winter injury risk………..197

Cattle combines………..198

Early frost prediction………..198

Late-season weed control………..199

Alfalfa diseases………..199

Banding herbicides………..200

Preparing bins………..201

Controlling brome………..202

Fish Kills And Bottom-Water Hypoxia In The Neuse River And Estuary: Reply To Burkholder Et Al., Hans W. Paerl, James L. Pinckney, John M. Fear, Benjamin L. Peierls

Faculty Publications

No abstract provided.

Ibpp Research Associates: Space And Extreme Environments, M. Ephimia Morphew - Society For Human Performance In Extreme Environments

International Bulletin of Political Psychology

Per M. Ephimia Morphew. President of the Society for Human Performance in Extreme Environments previously online at http://www.hpee.org, colleagues at the Institute of Biomedical Problems in Russia (IBMP) are engaged in an isolation experiment pertaining to space exploration that is two months underway and preliminary findings are reported [in the article entitled First Two Months of Simulated Isolation Passed.]

IBPP commentary includes a discussion of human factors and political psychology as parameters of space.

Micromagnetics Simulation Of Nanoshaped Iron Elements: Comparison With Experiment, Ngocnga Dao, S. R. Homer, Scott L. Whittenburg

Chemistry and Biochemistry Faculty Publications

A micromagnetics simulation has been conducted on nanostructured magnetic elements of iron in order to investigate the effect of the shape of the element on magnetic properties, such as domain formation and hysteresis loops. These results are compared with recent experimental studies. The results display an impressive agreement with both the experimentally observed magnetic domains in individual particles as well as the shape of the hysteresis loops. The simulation results then explain features in the hysteresis loops in terms of vortice formation and motion.

Measurement Of Oxygen Partial Pressure, Its Control During Hypoxia And Hyperoxia, And Its Effect Upon Light Emission In A Bioluminescent Elaterid Larva, G. S. Timmins, C. A. A. Penatti, E. J. H. Bechara, H. M. Swartz

Dartmouth Scholarship

This study investigates the respiratory physiology of bioluminescent larvae of Pyrearinus termitilluminans in relation to their tolerance to hypoxia and hyperoxia and to the supply of oxygen for bioluminescence. The partial pressure of oxygen (P(O2)) was measured within the bioluminescent prothorax by in vivo electron paramagnetic resonance (EPR) oximetry following acclimation of larvae to hypoxic, normoxic and hyperoxic (normobaric) atmospheres and during periods of bioluminescence (during normoxia). The P(O2) in the prothorax during exposure to an external P(O2) of 15.2, 160 and 760 mmHg was 10.3+/-2.6, 134+/-0.9 and 725+/-73 mmHg respectively (mean +/- s.d., N=5; 1 mmHg=0.1333 kPa). Oxygen supply …

1999 Nebraska Livestock Legislation, J. David Aiken

Cornhusker Economics

Several bills dealing with livestock issues were enacted in 1999, including LB882 (temporary zoning), LB870 (livestock waste permits) and LB835 (livestock contracts).

Emerging Marine Diseases: Climate Links And Anthropogenic Factors, C. D. Harvell, K. Kim, J. M. Burkholder, R. R. Colwell, P. R. Epstein, D. J. Grimes, E. E. Hoffmann, E. K. Lipp, A. D.M.E. Osterhaus, Robin M. Overstreet, J. W. Porter, G. W. Smith, G. R. Vasta

Harold W. Manter Laboratory of Parasitology: Faculty Publications

Mass mortalities due to disease outbreaks have recently affected major taxa in the oceans. For closely monitored groups like corals and marine mammals, reports of the frequency of epidemics and the number of new diseases have increased recently. A dramatic global increase in the severity of coral bleaching in 1997-98 is coincident with high El Niño temperatures. Such climate-mediated, physiological stresses may compromise host resistance and increase frequency of opportunistic diseases. Where documented, new diseases typically have emerged through host or range shifts of known pathogens. Both climate and human activities may have also accelerated global transport of species, bringing …

Distribution, Ecology, And Population Dynamics Of The American Burying Beetle [Nicrophorus Americanus Olivier (Coleoptera, Silphidae)] In South-Central Nebraska, Usa, Jon C. Bedick, Brett C. Ratcliffe, W. Wyatt Hoback, Leon G. Higley

University of Nebraska State Museum: Entomology Papers

The endangered American burying beetle, Nicrophorus americanus Olivier, was previously widespread throughout eastern North America. In the past century numbers of this beetle have drastically declined and currently remnant populations are known from only six states despite intensive surveying efforts conducted for the last nine years. Efforts aimed at discovering and managing remnant populations have been generally limited by a lack of knowledge concerning N. americanus biology. We used baited pitfall traps to define the range of the Gothenburg, Nebraska, population of N. americanus. Using mark-recapture techniques, we estimate that the annual Gothenburg population consists of more than one …

Mechanical Conditioning Of Tomato Seedlings Improves Transplant Quality Without Deleterious Effects On Field Performance, Lauren C. Garner, Thomas Björkman

Horticulture and Crop Science

Excessive stem elongation reduces plant survival in the field and hinders mechanical transplanting. Mechanical conditioning is an effective method for reducing stem elongation during transplant production. This investigation examined the consequences of mechanical conditioning, using brushing and impedance, on subsequent field performance of tomatoes (Lycopersicon esculentum Mill.). Mechanically conditioned transplants of processing tomatoes resumed growth after transplant shock as quickly as did untreated plants, and subsequent canopy development was also equal. In 4 years of field trials, yield was not reduced by mechanical conditioning. Transplants for fresh-market tomatoes may be more sensitive to injury than those for processing tomatoes because …

Legume Logic Number 109

Legume Logic

Contents

Herbicide resistant crops: What's the story?

Aphids - The spary debate

Swathing lupins

Ascochyta prevention

Budworm control

Pulse points 1998/99

Lupin pool payments

History Of Grassland Birds In Eastern North America, Robert A. Askins

Biology Faculty Publications

Until recently the severe decline in the populations of many species of grassland birds in eastern North America has aroused relatively little concern or conservation action. This response appears to be rooted in the perception that grassland birds invaded the East Coast from western grasslands after European settlers cleared the forest. Detailed historical accounts and analysis of pollen deposits, however, show that open grasslands existed on the East Coast of North America at the time of European settlement. Extensive grasslands resulted from burning and agricultural clearing by Native Americans. Natural disturbances, such as wildfire and beaver (Castor canadensis) activity, produced …

Health Transfers: An Application Of Health-Health Analysis To Assess Food Safety Regulations, Fred Kuchler, Jackqueline L. Teague, Richard A. Williams, Don W. Anderson

RISK: Health, Safety & Environment (1990-2002)

The authors apply a Health-Health Analysis to risks associated with harvesting Gulf oysters to evaluate that approach to managing health and safety risks.

Pesticide Residue Regulation: Analysis Of Food Quality Protection Act Implementation, Linda-Jo Schierow

RISK: Health, Safety & Environment (1990-2002)

Dr. Schierow discusses the effects of a recent statute on food safety.

Food Intake Patterns And Gallbladder Disease In Mexican Americans, Marilyn Tseng, Robert F. Devellis, Kurt R. Maurer, Meena Khare, Lenore Kohlmeier, James E. Everhart, Robert S. Sandler

Kinesiology and Public Health

Objective: Results of previous studies on diet and gallbladder disease (GBD), defined as having gallstones or having had surgery for gallstones, have been inconsistent. This research examined patterns of food intake in Mexican Americans and their associations with GBD. Design: Cross-sectional. Subjects: The study population included 4641 Mexican Americans aged 20±74 years who participated in the 1988±94 third National Health and Nutrition Examination Survey (NHANES III). GBD was diagnosed by ultrasound. Food intake patterns were identifed by principal components analysis based on food frequency questionnaire responses. Component scores representing the level of intake of each pattern were categorized into quartiles, …

Community-Based Education: Health Promotion For Farmers At The Country Market, M. Susan Jones, Beverly Siegrist

Nursing Faculty Publications

This article describes a unique approach used by baccalaureate nursing students, enrolled in a two-semester community health course, to address the priority of health concerns of agricultural workers in their own rural communities.

Results Of The Improved Soil Management & Cropping Systems For Waterlog-Prone Soils Project, Derk Bakker, G J. Hamilton, Peter I. Tipping, Cliff Spann, Doug Rowe

Resource management technical reports

No abstract provided.

Makaira Sp., Cf. M. Nigricans Lacépède, 1802 (Teleostei: Perciformes: Istiophoridae) From The Late Miocene, Panama, And Its Probable Use Of The Panama Seaway, Harry L. Fierstine

Biological Sciences

A nearly complete rostrum (USNM 358534) similar in morphology to the extant bluc marlin, Makaira nigricans Lacepede 1802, is identified from the GaUln Formation (late Miocene, Panama). Identification is based on comparison with a large series of Recent istiophorid species and with fossil species of the genus Makaira. The Gatlin specimen and additional examples from other fossil vertebrates provide evidence that the ancient Panama Seaway probably was a travel route between the Atlantic and Indo-Pacific for large marine vertebrates during the middle Miocene to earliest Pliocene. This is the first record of an istiophorid billfish from the Gatlin Fonnation and …

Variation And Repeatability Of Calling Behavior In Crickets Subject To A Phonotactic Parasitoid Fly, Gita R. Kolluru

Biological Sciences

Male Teleogryllus oceanicus (Orthoptera: Gryllidae) produce a conspicuous calling song to attract females. In some populations, the song also attracts the phonotactic parasitoid fly Ormia ochracea (Diptera: Tachinidae). I examined the factors affecting calling song by characterizing the calling behavior of caged crickets from an area where the fly occurs. Calling activity (proportion of time spent calling) was repeatable and a significant predictor of female attraction. However, calling activity in the parasitized population was lower than in an unparasitized Moorea population (Orsak, 1988), suggesting a compromise between high activity to attract females and low activity to avoid flies. Calling activity …