Digital Commons Network^™

Job Compensation In The Biotechnology Core Laboratory, Debra A. Mcmillen, William M. Old, Janice L. Bleibaum, Charles M. Nicolet, Katheryn R. Resing, Gautam Sarath, Satya P. Yadav

Gautam Sarath Publications

The results of a poll of core facility professionals by the Association of Biomolecular Resource Facilities (ABRF) Survey Committee.

Review Of Genes And The Environment By R. H. Burdon, Valery E. Forbes

Valery Forbes Publications

How diverse aspects of an organism’s environment influence the structure and function of its genes is of profound importance for understanding the molecular basis of evolution as well as the causes of disease, cancer and aging. Genes and the Environment addresses these issues from a molecular biological perspective. The author covers both natural environmental influences, such as extreme temperatures and water stress, as well as humancaused environmental influences, such as exposure to toxic chemicals. The author makes an effort to compare and contrast prokaryotic and eukaryotic systems and highlights distinctions between major groups of eukaryotes e.g., plants versus animals. to …

Stochastic Variation In Food Availability Influences Weight And Age At Maturity, Brigitte Tenhumberg, Andrew J. Tyre, Bernie Roitberg

School of Biological Sciences: Faculty Publications

Variation in mean food availability, and in the variance around the mean, affects the growth rate during development. Previous theoretical work on the influence of environmental quality or growth rates on the phenotypic traits age and size at maturation assumed that there is no variation in growth rate or food availability within a generation. We develop a stochastic dynamic programming (SDP) model of the foraging behavior of aphidophagous syrphids, and use this model to predict when syrphids should pupate (mature) when average food availability changes, or varies stochastically, during development. The optimal strategy takes into account not only the availability …

Patterns Of Annual Seed Production By Northern Hemisphere Trees: A Global Perspective, Walter D. Koenig, Johannes M.H. Knops

School of Biological Sciences: Faculty Publications

We tested whether annual seed production (masting or mast fruiting) in Northern Hemisphere trees is an evolved strategy or a consequence of resource tracking by comparing masting patterns with those of annual rainfall and mean summer temperatures, two environmental variables likely to correlate with available resources. There were generally significant negative autocorrelations between the seed crop in year x and year x+1 (year x+2 in species of Quercus requiring 2 yr to mature acorns), as expected if resources are depleted in mast years in part by switching resources from growth to reproduction. Spatial autocorrelation in annual seed production generally declined …

Learning Improves Growth Rate In Grasshoppers, Reuven Dukas, Elizabeth A. Bernays

School of Biological Sciences: Faculty Publications

To quantify the adaptive significance of insect learning, we documented the behavior and growth rate of grasshoppers (Schistocerca americana) in an environment containing two artificial food types, one providing a balanced diet of protein and carbohydrate, which maximizes growth, and the other being carbohydratedeficient, which is unsuitable for growth. Grasshoppers in the Learning treatment experienced a predictable environment, where the spatial location, taste, and color of each food source remained constant throughout the experiment. In contrast, grasshoppers of the Random treatment developed in a temporally varying environment, where the spatial location, taste, and color of the balanced and …

Clonal Growth Of Lithospermum Caroliniense (Boraginaceae) In Contrasting Sand Dune Habitats, Stephen G. Weller, Kathleen H. Keeler, Barbara A. Thomson

School of Biological Sciences: Faculty Publications

The occurrence of clonal growth of distylous Lithospermum caroliniense was investigated in a population in the Nebraska Sandhills, an area where sand dunes have been relatively stable for at least 1,500–3,000 yr, and compared to a population occurring at the Indiana Dunes, an area of active sand dune formation. Spatial autocorrelation analysis indicated the occurrence of significant clonal propagation of genetically based floral morphs at Arapaho Prairie, but not for the Indiana Dunes. Apparent clonal growth in the Sandhills population had no overall negative effect on pollen deposition or fecundity relative to the Indiana population, although in some large clones …

Surviving The Flood: Plastron Respiration In The Non-Tracheate Arthropod Phrynus Marginemaculatus (Amblypygi: Arachnida), Eileen Hebets, Reginald F. Chapman

Eileen Hebets Publications

Specimens of Phrynus marginemaculatus can remain responsive when submerged in water for more than 24 hours. Behavioral data indicate that P. marginemaculatus utilizes dissolved oxygen from the surrounding water. Scanning electron miscroscopy and light microscope sections show cuticular modifications for plastron respiration. All previous examples of plastron respiration have involved animals with tracheal systems, but amblypygids respire through the use of two pairs of book lungs. This study provides the first example of plastron respiration not only in the order Amblypygi, but also, in any non-tracheate arthropod.

Oxidative Stress Resistance: A Robust Correlated Response To Selection In Extended Longevity Lines Of Drosophila Melanogaster?, Lawrence G. Harshman, Beth A. Haberer

Lawrence G. Harshman Publications

Stress resistance is associated with longevity in Drosophila melanogaster and other model organisms used for genetic research. The present study tests for oxidative stress resistance in one set of lines selected for late-life reproduction and extended longevity. Both females and males from the selected lines were appreciably more resistant to oxidative stress than were flies from the control lines. A relative increase in oxidative stress resistance is a correlated response to selection in this laboratory selection experiment. Increased oxidative stress resistance appears to be a relatively robust correlated response to laboratory selection for late-life reproduction and extended longevity.

Dispersion And Site Fidelity In A Tent-Roosting Population Of The Short-Nosed Fruit Bat (Cynopterus Sphinx) In Southern India, Jay F. Storz, J. Balasingh, P. Thiruchenthil Nathan, K. Emmanuel, Thomas H. Kunz

Jay F. Storz Publications

Patterns of dispersion and site fidelity were investigated in a tent-roosting population of the short-nosed fruit bat, Cynopterus sphinx (Megachiroptera), in southern India. A local population of C. sphinx occupied diurnal roosts in a variable subset of 45 stem tents constructed within the dense foliage of mast trees (Polyalthia longifolia). Individually marked tent-roosting bats were visually censused over the course of a 38-d interval spanning the postpartum oestrus period. On any given day, 33.3-85.7% (mean = 60.8%, SD = 14.2) of adult males roosted singly, with the remainder holding harems of 1-10 breeding females (mean = 3.01, SD …

Rhinocyllus Conicus -- Insights To Improve Predictability And Minimize Risk Of Biological Control Of Weeds, Svata M. Louda

Svata M. Louda Publications

A review of information on the release of Rhinocyllus conicus to control of Carduus spp. thistles in North America suggests at least 8 lessons for future biological control efforts. These lessons include the need for: 1) better a priori quantification of the occurrence and ecological effects of the weed; 2) improved incorporation of ecological criteria to supplement the phylogenetic information used to select plants for pre-release testing; 3) increased assessment of plausible direct and indirect ecological interactions when an agent looks promising but feeding tests suggest it is not strictly monophagous, including ecological factors determining host use and limiting population …

Predicting Non-Target Ecological Effects Of Biological Control Agents: Evidence From Rhinocyllus Conicus, Svata M. Louda, A. E. Arnett

Svata M. Louda Publications

The discovery and quantification of significant non-target ecological effects of Rhinocyllus conicus on native species in the northcentral USA provides the opportunity to experimentally evaluate factors that might help predict non-target host plant use, magnitude of direct impact with transference, and indirect effects mediated by trophic interactions. The relevance for biocontrol risk assessment of at least four important ecological relationships has emerged from these studies so far. These relationships include the role played in interaction outcome and ecological risk by: 1) ecological similarity of potential host plants, as well as phylogenetic distance; 2) synchrony of critical stages between insect and …

A Century Of Ornithology In Nebraska: A Personal View, Paul A. Johnsgard

Papers in Ornithology

The Nebraska Ornithologists’ Union celebrated its centennial year during 1999. During more than 65 years it has published a quarterly journal, the Nebraska Bird Review, and has also published several proceedings of annual meetings as well as special or “occasional” publications. During this same century one native Nebraska bird species (Passenger Pigeon) has become extinct, another (Eskimo Curlew) has possibly become extinct, and at least 15 species apparently have been extirpated as breeding species in the state. Additionally at least seven species have begun breeding successfully in the state, either through purposeful or accidental human efforts, or by range …

Role Of Esterase Gp70 And Its Influence On Growth And Development Of Dictyostelium Discoideum, Aidong Yuan, Catherine P. Chia

Papers in Microbiology

Gp70 is an esterase originally called crystal protein because of its presence in crystalline structures in aggregation-competent Dictyostelium discoideum cells. Although postulated to break down spore coats, the function of gp70 in vivo was incompletely investigated. Our immunolocalization and biochemical studies of vegetative D. discoideum amoebae show that gp70 was recruited to phagosomes and found in lysosomes. Purified gp70 was effective at hydrolyzing naphthyl substrates with acyl chains typical of lipids and lipopolysaccharides, indicating that the gp70 was involved in digesting endocytosed molecules. The activity of purified gp70 was inhibited by reductants that retarded its electrophoretic mobility and verified the …

Meningeal Worm In Deer From Western Nebraska, David W. Oates, Mauritz C. Sterner, Ed Boyd

Harold W. Manter Laboratory of Parasitology: Faculty Publications

One hundred seventy-eight whitetailed deer (Odocoileus virginianus) and 275 mule deer (Odocoileus hemionus) collected from locker plants in the western 2/3 of Nebraska (USA) in November 1997 were examined for the meningeal worm (Parelaphostrongylus tenuis). Parelaphostrongylus tenuis was identified in 17 (10%) of 168 white-tailed deer and in one (<1%) of 273 mule deer. This is the first naturally occurring infection of P. tenuis recorded in a mule deer.

Molecular And Morphometric Evidence For Separate Species Of Uncinaria (Nematoda: Ancylostomatidae) In California Sea Lions And Northern Fur Seals: Hypothesis Testing Supplants Verification, Steven A. Nadler, Byron J. Adams, Eugene T. Lyons, Robert L. Delong, Sharon R. Melin

Harold W. Manter Laboratory of Parasitology: Faculty Publications

California sea lions (Zalophus californianus) and northern fur seals (Callorhinus ursinus) are each believed to host distinct hookworm species (Uncinaria spp.). However, a recent morphometric analysis suggested that a single species parasitizes multiple pinniped hosts, and that the observed differences are host-induced. To explore the systematics of these hookworms and test these competing hypotheses, we obtained nucleotide sequences of nuclear ribosomal DNA (D2/D3 28S, D18/D19 28S, and internal transcribed spacer [ITS] regions) from 20 individual hookworms parasitizing California sea lion and northern fur seal pups where their breeding grounds are sympatric. Five individuals from an …

Molecular Systematics Of Mesocestoides Spp. (Cestoda: Mesocestoididae) From Domestic Dogs (Canis Familiaris) And Coyotes (Canis Latrans), Paul R. Crosbie, Steven A. Nadler, Edward G. Platzer, Cynthia Kerner, J. Mariaux, Walter M. Boyce

Harold W. Manter Laboratory of Parasitology: Faculty Publications

The genus Mesocestoides Vaillant, 1863 includes tapeworms of uncertain phylogenetic affinities and with poorly defined life histories. We previously documented 11 cases of peritoneal cestodiasis in dogs (Canis familiaris L.) in western North America caused by metacestodes of Mesocestoides spp. In the current study, DNA sequences were obtained from metacestodes collected from these dogs (n = 10), as well as proglottids from dogs (n = 3) and coyotes (Canis latrans Say, 1823 [n = 2]), and tetrathyridia representing laboratory isolates of M. corti (n = 3), and these data were analyzed phylogenetically. Two nuclear genetic markers, 18S ribosomal …

Phylogeny Of The Ascaridoidea (Nematoda: Ascaridida) Based On Three Genes And Morphology: Hypotheses Of Structural And Sequence Evolution, Steven A. Nadler, Deborah S. S. Hudspeth

Harold W. Manter Laboratory of Parasitology: Faculty Publications

Ascaridoid nematodes parasitize the gastrointestinal tract of vertebrate definitive hosts and are represented by more than 50 described genera. We used 582 nucleotides (83% of the coding sequence) of the mitochondrial gene cytochrome oxidase subunit 2, in combination with published small- and large-subunit nuclear rDNA sequences (2,557 characters) and morphological data (20 characters), to produce a phylogenetic hypothesis for representatives of this superfamily. This combined evidence phylogeny strongly supported clades that, with 1 exception, were consistent with Fagerholm’s 1991 classification. Parsimony mapping of character states on the combined evidence tree was used to develop hypotheses for the evolution of morphological, …

Phylogenetic Relationships Among Species Of Contracaecum Railliet & Henry, 1912 And Phocascaris Høst, 1932 (Nematoda: Ascaridoidea) Based On Nuclear Rdna Sequence Data, Steven A. Nadler, S. D'Amelio, H. P. Fagerholm, B. Berland, L. Paggi

Harold W. Manter Laboratory of Parasitology: Faculty Publications

Nuclear-encoded large-subunit ribosomal DNA sequences were used to infer a phylogenetic hypothesis for 17 taxa (16 nominal species) of the genera Contracaecum and Phocascaris. Phylogenetic trees based on these data have been used to assess the validity of the taxonomic distinction between these genera, which was based on the presence or absence of certain structural features, rather than on explicit hypotheses of evolutionary history. Phylogenetic hypotheses based on parsimony, likelihood, and neighbor-joining analyses of these sequence data strongly support the hypothesis that species of Phocascaris are nested within the clade of Contracaecum species hosted by phocid seals, and are …

Molecular Phylogeny Of Clade Iii Nematodes Reveals Multiple Origins Of Tissue Parasitism, Steven A. Nadler, R. A. Carreno, H. Mejía-Madrid, J. Ullberg, C. Pagan, R. Houston, Jean-Pierre Hugot

Harold W. Manter Laboratory of Parasitology: Faculty Publications

Molecular phylogenetic analyses of 113 taxa representing Ascaridida, Rhigonematida, Spirurida and Oxyurida were used to infer a more comprehensive phylogenetic hypothesis for representatives of ‘clade III’. The posterior probability of multiple alignment sites was used to exclude or weight characters, yielding datasets that were analysed using maximum parsimony, likelihood, and Bayesian inference methods. Phylogenetic results were robust to differences among inference methods for most high-level taxonomic groups, but some clades were sensitive to treatments of characters reflecting differences in alignment ambiguity. Taxa representing Camallanoidea, Oxyurida, Physalopteroidea, Raphidascarididae, and Skrjabillanidae were monophyletic in all 9 analyses whereas Ascaridida, Ascarididae, Anisakidae, Cosmocercoidea, …

A Cox2 Molecular Phylogeny Of The Peronosporomycetes, Deborah S.S. Hudspeth, Steven A. Nadler, Michael E.S. Hudspeth

Harold W. Manter Laboratory of Parasitology: Faculty Publications

The evolutionary history of the mitochondrial COX2 locus has been used to infer the phylogenetic relationships among 15 peronosporomycete and a hyphochytriomycete species. This molecular phylogenetic analysis at both the ordinal and generic levels provides strong evidence for the recognition of the Saprolegniomycetidae and the Peronosporomycetidae as natural groups, and for the monophyly of the Saprolegniales, Leptomitales and Pythiales. A three amino acid insertion/deletion event (indel) has been identified as a putative synapomorphy for the Saprolegniales. Parsimony mapping of 12 morphological and biochemical characters on the COX2 molecular phylogeny yields an hypothesis for peronosporomycete ancestral states and shared-derived features.

Relationships Of Nematodirus Species And Nematodirus Battus Isolates (Nematoda: Trichostrongyloidea) Based On Nuclear Ribosomal Dna Sequences, Steven A. Nadler, Eric P. Hoberg, Deborah S.S. Hudspeth, Lora G. Rickard

Harold W. Manter Laboratory of Parasitology: Faculty Publications

Nuclear ribosomal sequence data from the internal transcribed spacers (ITS-1 and ITS-2), 5.8S subunit, and regions of the 18S and 28S genes were used to investigate sequence diversity among geographic samples of Nematodirus battus, and to infer phylogenetic relationships among Nematodirus species. Phylogenetic analysis of these data yielded strong support for relationships among species, depicting Nematodirus helvetianus and Nematodirus spathiger as sister-taxa and a clade of these two species and Nematodirus filicollis. This tree is consistent with caprine bovids as ancestral hosts, with a subsequent host shift to Bovinae in N. helvetianus. Eleven of fourteen N. battus sequences …

A Cultivated Taste For Yeast., C Brenner

Kimmel Cancer Center Faculty Papers

The availability of complete genomic sequences of Saccharomyces cerevisiae has catalyzed a cultural change in the practice of yeast biology, providing opportunities to develop high throughput techniques to define protein function, to define drug targets, and to discover and characterize drugs.

Population Trends In Furbearers In Nebraska, L. M. Landholt, Hugh H. Genoways

University of Nebraska State Museum: Mammalogy Papers

Population trends are documented from 1941 to 1997 for the 12 species of furbearing mammals harvested in Nebraska. Populations of red fox (Vulpes vulpes, raccoon (Procyon lotor), beaver (Castor canadensis), coyote (Canis lupus), and bobcat (Lynx rufus) have increased during this period. Populations of muskrat (Ondatra zibethicus), mink (Mustela vison), eastern spotted skunk (Spilogale putorius), long-tailed weasel (Mustela frenata), and striped skunk (Mephitis mephitis) have decreased. Populations of mink, eastern spotted skunk, long-tailed weasel, and striped skunk may have decreased …

Track Theory Predictions For Single-Hit Cell Survival, Robert Katz, Francis Cucinotta

Robert Katz Publications

The track theory of cell survival after heavy-ion irradiation is based on the probability of survival after a single-particle transit, called ‘‘ion-kill’’ (not track core), joined to the cumulative effect of δ rays from adjacent ions in a beam, called ‘‘gamma-kill’’ (not penumbra). The model offers a set of equations containing four parameters, E₀ and m for the single-hit multitarget statistical model for gamma-kill, and additionally σ₀ and κ for ion-kill. A single set of parameters is used to fit a family of survival curves obtained with ions of different LET simultaneously.

Old And New Anti-Epileptic Drugs In Pregnancy, Giovanni Regesta, Paolo Tanganelli

Saudi Medical Journal

During the recent years, a significant number of anti-epileptic drugs have been approved for prescription in different countries. In addition, some other promising drugs are in various stages of development. Soon after each drug has found its place in the therapeutic arsenal, pregnancies with exposure occur, with an increased risk of birth defect and developmental disturbances. As regards the possible teratogenic effect of the new anti-epileptic drugs, apart some individual reports we have only the results of pre-clinical toxicological studies which are difficult to extrapolate to the human situation, because of the well-known interspecies differences in pharmacokinetics and pharmacodynamics. Furthermore, …

Adolescent Endocrinology In Saudi Arabia, Mohamed A. Abdullah, Hamad S. Al-Salhi, Mona A. Anani, Liza Q. Melendrez

Saudi Medical Journal

OBJECTIVE: The importance of providing special health care services for adolescents has been recently stressed. In Saudi Arabia, adolescents have no special services. In this study, we describe our first 5 years experience of an adolescent endocrinology clinic in Security Forces Hospital. We believe it is the first clinic with this objective in the Kingdom. METHODS: An adolescent endocrinology clinic was run by a team composed of pediatric endocrinologist, diabetic nurse educator, clinic nurse and a dietician in collaboration with other supportive staff and consultants from other disciplines. The methodology of setting up, staffing and running the clinic is described. …

Micronutrient And Iron Supplementation And Effective Anti-Malarial Treatment Synergistically Improve Childhood Anaemia, H. Ekvall, Zul Premji, A. Bjorkman

Pathology, East Africa

The control of childhood anaemia in malaria holoendemic areas is a major public health challenge for which an optimal strategy remains to be determined. Malaria prevention may compromise the development of partial immunity. Regular micronutrient supplementation has been suggested as an alternative but its effectiveness remains unsettled. We therefore conducted a randomised placebo-controlled intervention trial with 207 Tanzanian children aged 5 months to 3 years on the efficacy of supervised supplementation of low-dose micronutrients including iron (Poly Vi-Sol with iron) three times per week, with an average attendance of ≥ 90%. The mean haemoglobin (Hb) level increased by 8 g/l …

Expression Of A Dominant-Negative Mutant Of P21ras Inhibits Induction Of Nitric Oxide Synthase And Activation Of Nuclear Factor-Kb In Primary Astrocytes, Kalipada Pahan, Xiaojuan Lu, Michael J. Mckinney, Charles Wood, Faruk G. Sheikh, John R. Raymond

School of Biological Sciences: Faculty Publications

The present study underlines the importance of p21ras in regulating the inducible nitric oxide synthase (iNOS) in primary astrocytes. Bacterial lipopolysaccharides induced the GTP loading of p21ras, and the expression of a dominant-negative mutant of p21ras (Dp21ras) inhibited lipopolysaccharide-induced GTP loading in rat primary astrocytes. To delineate the role of p21ras in the induction of iNOS, we examined the effect of Dp21ras on the expression of iNOS and the production of nitric oxide. It is interesting that expression of Dp21ras markedly inhibited the production of nitric oxide and the expression of iNOS in lipopolysaccharide- and pro-inflammatory cytokine (tumor necrosis factor-a, …

Plant Quality And Spider Predation Affects Grasshoppers (Acrididae): Food-Quality-Dependent Compensatory Mortality, Mark A. Oedekoven, Anthony Joern

School of Biological Sciences: Faculty Publications

For insect herbivores, population responses reflect interactions among multiple factors, including abiotic conditions, food plant availability, and biotic interactions guided by food limitation and natural enemies. In this set of field experiments, we evaluated the interactive, dynamic effects of limited food supply and predation from wolf spiders (Lycosidae) on mortality in Ageneotettix deorum, a common grasshopper (Acrididae) from North American sandhills grasslands. We attempted to determine whether the combined effects of food availability and spider predation on mortality were (1) noncompensatory, with the effects of each factor summing to determine ultimate population size, or (2) compensatory, where the effect …

Biosystematics And Evolution Of The Triatominae = Biossistemática E Evolução De Triatomíneos, Christopher J. Schofield

Harold W. Manter Laboratory of Parasitology: Library Materials

Abstract

In this paper we summarize the systematics of the 130 currently recognized species of Triatominae and the key features of their evolutionary background. There is increasing evidence that the subfamily has polyphyletic origins, with the various tribes and species groups probably arising from different reduviid lineages in relatively recent times.

Resumo

Neste trabalho resume-se a sistemática das 130 espécies de triatomíneos atualmente reconhecidas, com os elementos principais de sua evolução. Existem evidências crescentes para a origem polifilética da subfamília. As diferentes tribos e grupos de espécies que a compõem teriam surgido recentemente, a partir de diferentes linhagens de reduviídeos.