Life Sciences Commons^™

Alpha Status, Dominance, And Division Of Labor In Wolf Packs, L. David Mech

United States Geological Survey, Northern Prairie Wildlife Research Center: Publications

The prevailing view of a wolf (Canis lupus) pack is that of a group of individuals ever vying for dominance but held in check by the “alpha” pair, the alpha male and alpha female. Most research on the social dynamics of wolf packs, however, has been conducted on non-natural assortments of captive wolves. Here I describe the wolf-pack social order as it occurs in nature, discuss the alpha concept and social dominance and submission, and present data on the precise relationships among members in free-living packs, based on a literature review and 13 summers of observations of wolves …

A Method For Estimating Marine Habitat Values Based On Fish Guilds, With Comparisons Between Sites In The Southern California Bight, Alan B. Bond, John S. Stephens, Jr., Daniel J. Pondella, Ii, M. James Allen, Mark Helvey

Papers in Behavior in Biological Sciences

Habitat valuation is an essential tool for tracking changes in habitat quality and in adjudicating environmental mitigation. All current methods for estimating habitat values of coastal marine sites rely heavily on the opinion of experts or on data variables that can readily be manipulated to influence the outcome. As a result, unbiased, quantitative comparisons between the values of different marine habitats are generally unavailable. We report here on a robust, objective technique for the valuation of marine habitats that makes use of data that are commonly gathered in surveys of marine fish populations: density, fidelity, and mean size. To insure …

Early And Late Endosomal Compartments Of Entamoeba Histolytica Are Enriched In Cysteine Proteases, Acid Phosphatase And Several Ras-Related Rab Gtpases, Lesly A. Temesvari, Ed Harris, Samuel L. Stanley Jr., James Cardelli

Department of Biochemistry: Faculty Publications

Pure populations of early and late endosomes of Entamoeba histolytica were isolated by magnetic fractionation and characterized. It was shown that these vesicles were enriched in acid phosphatase and cysteine protease activities. An important virulence factor, a 27-kDa cysteine protease, was also enriched in early and late endosomes of E. histolytica. These data suggest that E. histolytica hydrolases reside in compartments that are part of or communicate with the endosomal pathway. To begin to identify the role of Rab GTPases in E. histolytica, an oligonucleotide approach was employed to screen an E. histolytica cDNA library for genes encoding …

Grassland Vegetation Changes And Nocturnal Global Warming, Richard D. Alward, James K. Detling, Daniel G. Milchunas

School of Biological Sciences: Faculty Publications

Global minimum temperatures (T_MIN) are increasing faster than maximum temperatures, but the ecological consequences of this are largely unexplored. Long-term data sets from the shortgrass steppe were used to identify correlations between T_MIN and several vegetation variables. This ecosystem is potentially sensitive to increases in T_MIN. Most notably, increased spring T_MIN was correlated with decreased net primary production by the dominant C₄ grass (Bouteloua gracilis) and with increased abundance and production by exotic and native C₃ forbs. Reductions in B. gracilis may make this system more vulnerable to invasion by …

Comparison Of Common Cytotypes Of Andropogon Gerardii (Andropogoneae, Poaceae), Kathleen H. Keeler, Geoffrey A. Davis

School of Biological Sciences: Faculty Publications

Many plant species contain populations with more than one polyploid cytotype, but little is known of the mechanisms maintaining several cytotypes in a population. Andropogon gerardii cytotypes were compared to evaluate different models of autopolyploid cytotype coexistence. The enneaploid (90 chromosome, 9x) cytotype was found to be larger and taller than the hexaploid (60 chromosome, 6x) cytotype. Seed production is significantly more efficient in hexaploids, but seed production per area was not significantly different. The two cytotypes are not exomorphologically separable in the field because of great plasticity in response to environmental variation and wide variation …

Coordinate Transcriptional Control In The Hyperthermophilic Archaeon Sulfolobus Solfataricus, Cynthia Haseltine, Rafael Montalvo-Rodriguez, Elisabetta Bini, Audrey Carl, Paul H. Blum

School of Biological Sciences: Faculty Publications

The existence of a global gene regulatory system in the hyperthermophilic archaeon Sulfolobus solfataricus is

described. The system is responsive to carbon source quality and acts at the level of transcription to coordinate

synthesis of three physically unlinked glycosyl hydrolases implicated in carbohydrate utilization. The specific

activities of three enzymes, an a-glucosidase (malA), a b-glycosidase (lacS), and an a-amylase, were reduced

4-, 20-, and 10-fold, respectively, in response to the addition of supplementary carbon sources to a minimal

sucrose medium. Western blot analysis using anti-a-glucosidase and anti-b-glycosidase antibodies indicated

that reduced enzyme activities resulted exclusively from …

Bacterial Growth State Distinguished By Single-Cell Protein Profiling: Does Chlorination Kill Coliforms In Municipal Effluent?, David Rockabrand, Teresa Austin, Robyn Kaiser, Paul H. Blum

School of Biological Sciences: Faculty Publications

Municipal effluent is the largest reservoir of human enteric bacteria. Its public health significance, however,

depends upon the physiological status of the wastewater bacterial community. A novel immunofluorescence

assay was developed and used to examine the bacterial growth state during wastewater disinfection. Quantitative

levels of three highly conserved cytosolic proteins (DnaK, Dps, and Fis) were determined by using

enterobacterium-specific antibody fluorochrome-coupled probes. Enterobacterial Fis homologs were abundant

in growing cells and nearly undetectable in stationary-phase cells. In contrast, enterobacterial Dps homologs

were abundant in stationary-phase cells but virtually undetectable in growing cells. The range of variation in

the abundance of …

Cynopterus Sphinx, Jay F. Storz, Thomas H. Kunz

Jay F. Storz Publications

Order Chiroptera, Family Pteropodidae, Subfamily Pteropodinae, Tribe Cynopterini, Subtribe Cynopterina, Genus Cynopterus. Five species are recognized: C. brachyotis, C. horsfieldi, C. nusatenggara, C. sphinx, and C. titthaecheileus (Koopman, 1993). A key to the species is given in Lekagul and McNeely (1977).

Evolutionary Relationships Among The Protostrongylidae (Nematoda: Metastrongyloidea) As Inferred From Morphological Characters, With Consideration Of Parasite-Host Coevolution, Ramon A. Carreno, Eric P. Hoberg

Harold W. Manter Laboratory of Parasitology: Faculty Publications

The phylogeny of nematodes in the family Protostrongylidae (Nematoda: Metastrongyloidea) was reconstructed by cladistic analysis of 28 binary and multistate characters derived from comparative morphology. Analyses were hierarchical, and examined (1) relationships among genera, including 13 ingroup taxa and Metastrongylidae as an outgroup (single tree, 78 steps, consistency index [CI]=0.705); and (2) relationships among genera and species groups including 21 ingroup taxa and Metastrongylus apri as an outgroup (single tree, 76 steps, CI=0.582). In the species-level tree, Protostrongylidae was divided into 2 major clades, one containing the subfamilies Muelleriinae (including the recently described Umingmakstrongylus pallikuukensis) Elaphostrongylinae, and the Varestrongylinae …

Experimental Infections Of Muskoxen (Ovibos Moschatus) And Domestic Sheep With Umingmakstrongylus Pallikuukensis (Nematoda: Protostrongylidae): Parasite Development, Population Structure, And Pathology, Susan J. Kutz, Eric P. Hoberg, Lydden Polley

Harold W. Manter Laboratory of Parasitology: Faculty Publications

Three captive muskoxen (Ovibos moschatus) were successfully infected with third-stage larvae of Umingmakstrongylus pallikuukensis digested or emerged from the slugs Deroceras reticulatum and D. laeve, for the first time completing the life cycle of this parasite under experimental conditions. The course of parasite development and patency was followed for 26 months post infection (p.i.) using fecal examinations and radiography. The prepatent periods in two of the muskoxen were 91 and 95 days and the patent period in one extended for 23 months. Larval production peaked 13–14 months p.i. On postmortem of two of the muskoxen at months …

Octamer-Based Genome Scanning Distinguishes A Unique Subpopulation Of Escherichia Coli O157:H7 Strains In Cattle, Jaehyoung Kim, Andrew K. Benson

Department of Food Science and Technology: Faculty Publications

Multilocus-genotyping methods have shown that Escherichia coli O157:H7 is a geographically disseminated clone. However, highresolution methods such as pulse-field gel electrophoresis demonstrate significant genomic diversity among different isolates. To assess the genetic relationship of human and bovine isolates of E. coli O157:H7 in detail, we have developed an octamer-based genome-scanning methodology, which compares the distance between over-represented, strand-biased octamers that occur in the genome. Comparison of octamer-based genome-scanning products derived from >1 megabase of the genome demonstrated the existence of two distinct lineages of E. coli O157:H7 that are disseminated within the United States. Human and bovine isolates are nonrandomly …

Eimeria From Bats Of Bolivia: Two New Species From Vespertilionid Bats, Donald W. Duszynski, Damien T. Scott, Xiaomin Zhao

Harold W. Manter Laboratory of Parasitology: Faculty Publications

Between 1985 and 1987, fecal samples were collected from 71 bats representing 14 species (Desmodontidae, Molossidae, Noctilionidae, Phyllostomidae, Vespertilionidae) from 8 localities in 3 states (Beni, Pando, Santa Cruz) in Bolivia, South America. Of these, 2 black myotid bats (Vespertilionidae), Myotis nigricans, and 1 tent-making bat (Phyllostomidae), Uroderma magnirostrum, had oocysts in their feces that represent undescribed species of Eimeria. The new species from M. nigricans (2/4, 50%) has sporulated oocysts that are subspheroidal, 18.9 × 16.9 (17-23 × 14-20) μm, without a micropyle; oocyst residuum of 6-8 spheroidal globules and 1 highly refractile polar granule are …

Growth And Feeding Studies On The Algal Feeding Stage Of A Pfiesteria-Like Dinoflagellate, David W. Seaborn, A. Michelle Seaborn, William M. Dunstan, Harold G. Marshall

Biological Sciences Faculty Publications

The dinoflagellate Cryptoperidiniopsis sp. was isolated from sediment samples taken from Virginia estuaries, and established in culture for subsequent growth and feeding studies. The maximum abundance, or yield, of Cryptoperidiniopsis is exponentially related to the concentration of algal prey and is saturated at about 4.00 X 10⁵ mL^-1. Salinity from 10-20 ppt and temperature between 15-25 C have no effect on the yield of this form of Cryptoperidiniopsis. Light intensity has a secondary effect in that the algal prey reproduces more quickly in higher light as they are being grazed. Growth rates of Cryptoperidiniopsis were …

A Case Study Of Bioengineering In America: Profits, Risks And Standards Of Value In The Commercialization Of Monsanto Company's Newleaf Potato, Bridget Lyons, Teresa Ralabate, Nadhim Frangul

WCBT Faculty Publications

Last year, approximately 45 million acres of American farmland were planted with crops that had been genetically engineered to either produce their own pesticides, or withstand herbicides. The long and short-term effects of this biotechnology on humans and the environment, are being studied, but remain unknown. Leading the way in the field of bioengineered crops is the Missouri-based Monsanto Company. Monsanto believes that current agricultural practices are inconsistent with sustainable development. The NewLeaf potato is one of three products Monsanto has created to feed the growing world population. The genetically engineered crop produces, in every cell of the plant, a …

Characterization Of Rat Pulmonary Carboxylesterase, Timothy J. Wallace

Theses and Dissertations

The 1839 bp cDNA for rat pulmonary carboxylesterase was cloned by reverse transcription polymerase chain reaction (RT PCR) from total rat lung RNA using specific primers derived from the 5' and 3' untranslated regions of rat hepatic cholesteryl ester hydrolase (CEH). The unique cDNA was sequenced and found to have 99% homology with hepatic CEH. This homology extends to the predicted amino acid sequences which show only six amino acid residue differences in the coding region: three conserved and three nonconserved changes. However, the catalytic activitites of the two proteins are dramatically different. While CEH hydrolyzes cholesterol oleate, the pulmonary …

The Roles Of Several Kinases In Mice Tolerant To Delta-9-Tetrahydrocannabinol, Matthew C. Lee

Theses and Dissertations

It has been suggested that the CB1 G-protein-coupled receptor is internalized following agonist binding and activation of the second messenger pathways. The process of desensitization and resensitization is intimately involved with receptor internalization. Phosphorylation alters tolerance to cannabinoids thus contributing to tolerance. It is proposed that phosphorylation enhances the down-regulation of the CB1 receptor. These findings led us to look at which kinase(s) may be involved in cannabinoid tolerance. We therefore hypothesize that by preventing phosphorylation of the CB1 receptor, we may reverse tolerance. We evaluated our hypothesis by testing the role of several kinases in tolerance: protein kinase A …

Educational And Occupational Aspirations Of Rural High School Seniors In The Private And Public Schools In Northwest Iowa, Duane Bajema

Faculty Work Comprehensive List

Research has suggested that rural youth have lower educational and occupational aspirations than their nonrural counterparts, and they may experience barriers to educational and occupational attainment. Discrepancies and barriers that may exist have implications for educational policy and educational planning.

Seventeen rural high schools in northwest Iowa were examined; thirteen public and four private schools. Rural high school students were studied to examine their perceptions concerning potential educational and occupational barriers. Student characteristics and qualities were examined based on where the student lived and the type of school they attended. Students who had been involved in the agricultural curricula in …

A Crna Probe Detects Prunus Necrotic Ringspot Virus In Three Peach Cultivars After Micrografting And In Peach Shoots Following Long-Term Culture At 4°C, K. Heuss, Q. Liu, F.A. Hammerschlag, R.W. Hammond

United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications

As part of a program to develop transgenic peach (Prunus persica L. Batsch) cultivars with resistance to Prunus necrotic ringspot virus (PNRSV), we are testing a system for measuring virus in peach shoot cultures. Micrografting in vitro is used for inoculation and slot-blot hybridization, with a digoxigenin (DIG)-labeled cRNA probe complementary to the 5´ open reading frame (ORF) of PNRSV RNA 3, for detection. In this study, we investigated whether infected shoots maintain virus infection over long periods of culture at 4°C and if PNRSV-infected ‘Suncrest’ shoot cultures can serve as graft bases to transmit virus equally well into …

Comparison Of Precipitation Catch Between Nine Measuring Systems, Clayton L. Hanson, Gregory L. Johnson, Albert Rango

United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications

A site was established by the United States Department of Agriculture-Agricultural Research Service on the Reynolds Creek Experimental Watershed in southwest Idaho in the fall of 1987 and operated through the spring of 1994, to compare precipitation catch between nine precipitation-measuring systems. This site was established as a part of the World Meteorological Organization’s program to compare current national methods of measuring solid precipitation (snow), so the primary emphasis of this study was the measurement of snowfall. Over seven seasons, four of the systems measured snowfall and total catch, which included snow, mixed snow and rain, and rain events, within …

The Concept Of Familiarity And Pest Resistant Plants, Karen Hokanson, David Heron, Subhash Gupta, Susan Koehler, Craig Roseland, Shanthu Shantharam, John Turner, James White, Michael Schechtman, Sally Mccammon, Rebecca Bech

United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications

Meetings such as this workshop provide an all too rare opportunity for scientists from different disciplines to share their perspectives on a topic of common interest. In this case we examine the use of pest resistant plants in managed ecosystems. USDA-APHIS has a clear interest in this subject because it is involved in regulating transgenic plants, many of which have been engineered with some sort of pest resistance, within its broad authority to protect plants under the Federal Plant Pest Act and the Plant Quarantine Act. Since 1992, when APHIS received its first request to determine non-regulated status for a …

Report Of The Cucurbit Working Group, James D. Mccreight, Jack Staub

United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications

Cucumber (Cucumis sativus L.) originated in India, melon (C. melo L.) and watermelon (Citrullus lanatus) in Africa, and squash, pumpkin, and gourd (Cucurbita spp.) in the Americas. Thus, cucumber, melon, and watermelon (including citron) are relatively recent introductions to the New World. Most domesticated species of Cucurbita were introduced from Mexico, Central America, and South America with the migration of native Americans centuries earlier. Wax gourd (Benincasa hispida (Thunb.) Logr.) is from Southeast Asia. Bottle gourd (Lagenaria siceraria (Molina) Stand.) is of African origin. South Asia is the probable center of …

Physical Mapping Of The Bovine, Caprine And Ovine Homologues Of The Paired Box Gene Pax8, N. L. Lòpez-Corrales, T. S. Sonstegard, T. P. L. Smith

United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications

The PAX8 gene, a member of the human paired box gene family, was mapped by FISH to chromosome 11 in cattle and goat and to the short arm of chromosome 3 in sheep. The cytogenetic position of PAX8 on BTA 11 and on its homologue OAR 3p lies in the region where the interleukin beta (IL1B) gene has been previously located, (BTA 11q22.1→q22.3 and OAR 3p25→q26 respectively; Lòpez-Corrales et al., 1998). The results indicated that PAX8 as well as interleukin beta and interleukin alpha (IL1B and IL1A) genes detected on the human chromosome segment HSA 2q13→q21 maintain a similar …

Analysis Of Human Skin Emanations By Gas Chromatography/Mass Spectrometry. 1. Thermal Desorption Of Attractants For The Yellow Fever Mosquito (Aedes Aegypti) From Handled Glass Beads, Ulrich R. Bernier, Matthew M. Booth, Richard A. Yost

United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications

Handled glass has the ability to collect and concentrate nonaqueous human skin emanations while minimizing the collection of aqueous perspiration. Compounds originating from the skin and collected on glass have previously been found to attract the Aedes aegypti species of mosquito. Therefore, glass beads were used as the medium to collect skin emanations from humans for subsequent chemical analysis. This process consisted of a 5-15-min collection of sample on glass beads, followed by loading the beads into a gas chromatograph (GC) injector insert for subsequent desorption of the collected compounds onto the GC column. After cryofocusing by liquid nitrogen at …

Midseason Stalk Breakage In Corn As Affected By Crop Rotation, Hybrid, And Nitrogen Fertilizer Rate, Wallace Wilhelm, Mark A. Liebig, Gary E. Varvel, Tracy M. Blackmer

United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications

In July of 1993 and 1994, southern Nebraska experienced devastating windstorms, with winds estimated to exceed 45 m s^-1. These storms resulted in severe brittle-snap of corn (Zea mays L.), with stalks breaking near the primary ear node in the basal portion of an elongating internode. In the storm path were several experiments established on a Hord silt loam (Cumulic Haplustolls) to determine the effect of selected management practices (crop rotation, hybrid selection, planting date, and N fertilization) on nitrate leaching to ground water from irrigated cropland. After the storms, the number of broken plants was determined …

When That Tune Runs Through Your Head: A Pet Investigation Of Auditory Imagery For Familiar Melodies, Andrea R. Halpern, Robert J. Zatorre

Faculty Journal Articles

The present study used positron emission tomography (PET) to examine the cerebral activity pattern associated with auditory imagery forfamiliar tunes. Subjects either imagined the continuation of nonverbaltunes cued by their first few notes, listened to a short sequence of notesas a control task, or listened and then reimagined that short sequence. Subtraction of the activation in the control task from that in the real-tune imagery task revealed primarily right-sided activation in frontal and superior temporal regions, plus supplementary motor area(SMA). Isolating retrieval of the real tunes by subtracting activation in the reimagine task from that in the real-tune imagery task …

Change In Agricultural Values 1982/83 To 1995/96 - Western Australia, Graham Annan, Dennis Van Gool, Werner Runge

Agriculture reports

A summary of the change in agricultural values from 1982/83 to 1995/96 in Western Australia. It includes maps and graphs of total figures for agriculture and for broad scale crops, horticultural crops, meat products and animal products.

Examination Of Signals Involved In Dexamethasone Induced Apoptosis In Nb2 Lymphoma Cells, Suhas Badarinath

Theses and Dissertations

Consistent with previous studies, we demonstrated that dexamethasone (Dex) caused cytolysis/apoptosis in log phase Nb2 lymphoma cells, while prolactin (Prl) inhibited this effect. The Nb2 model was used to investigate the mechanisms of apoptosis control with the aid of immunocytochemistry (ICC). We established with absorption the specificity of staining due to Fas, Fas Ligand, Bcl-2, and Bax antibodies (the specificity of anti-p53 could not be verified). Dex-induced cytolysis/apoptosis was detected in synchronized (G⁰/G¹) cells after 6 and 8 hours of Dex exposure. A novel, computerized technique was used to quantitate the proportion of cells immunostained for the signals of interest …

The Chondrocranium Of The Mexican Burrowing Toad, Rhinophrynus Dorsalis, Charles C. Swart, Rafael O. De Sá

Biology Faculty Publications

The chondrocranium of Rhinophrynus dorsalis is described and illustrated. Autapomorphies of R. dorsalis are the presence of the symplectic cartilage and a cartilaginous process on the ascending process of the palatoquadrate. Synapomorphies of Rhinophrynus shared with the Pipidae are: (1) early formation of the lower jaw and (2) presence of a suprarostral plate. Alternative developmental pathways for the formation of the suprarostral plate are considered. Histological data indicates that the suprarostral plate forms from: (1) the early fusion of the cornua trabeculae with the suprarostral cartilages, (2) an anterior growth of the ethmold plate, and (3) subsequent fusion …

Unidad De Los Anfibios Modernos Como Grupo Natural, Rafael O. De Sá

Biology Faculty Publications

RESUMEN

La monofilia de la infraclase Lissamphibia ha sido cuestionada. Algunos autores sugieren un origen independiente del Orden Gymnophiona basados en la condición compacta (= estegocrotafía) del cráneo de la cecilias. La presente revisión indica la irrelevancia del estegocrotafismo para establecer las relaciones filogenéticas del grupo. Los datos disponibles sugieren: 1) el estegocrotafismo es secundariamente derivado en cecilias, y 2) Lissamphibia representa un grupo monofilético.

SUMMARY

Unity of modern Amphibians as a natural group

The monophyly of Lissamphibia has been previously questioned. Some authors suggested an independent origin of Gymnophiona based on the solid condition (= stegokrotaphy) of the caecilian …

Investigating The Allosteric Behavior Of Malate Dehydrogenase From Escherichia Coli, Eman M. Ghanem

Masters Theses

Regulatory mechanisms of malate dehydrogenase from E.coli (eMDH) involving NADH as an allosteric effector were investigated. The reaction was studied in both directions: malate oxidation and oxaloacetate reduction. When malate was the variable substrate, a plot of rate against substrate concentration was sigmoidal in the presence of 0.065 mM NADH, which indicates the presence of an allosteric site for NADH on the enzyme. Binding of NADH at the allosteric site causes conformational changes in the active site and, thereby, changes the catalytic activity of the enzyme. An increase in K_m value, from 1.3 to 3.9 mM malate was observed, …