Life Sciences Commons^™

Predicting Plant Extinction Based On Species-Area Curves In Prairie Fragments With High Beta Richness, Brian J. Wilsey, Leanne M. Martin, H. Wayne Polley

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

Species-area relationships and island biogeography theory are commonly used to predict how species richness will decline with fragmentation. There are a variety of largely untested assumptions in these approaches, including the assumptions that populations are distributed uniformly before fragmentation, and that local extinctions are due to effects of small population sizes. If populations are not distributed uniformly, then populations can be abundant locally but rare globally. This would cause extinction rates to be smaller than predicted.We tested extinction theory by developing estimates of the number of plant species that should be present in small tallgrass prairie fragments and then testing …

Patterns Of Plant Species Diversity In Remnant And Restored Tallgrass Prairies, H. Wayne Polley, Justin D. Derner, Brian J. Wilsey

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

To restore diversity of native vegetation, we must understand factors responsible for diversity in targeted communities. These factors operate at different spatial scales and may affect the number and relative abundances of species differently. We measured diversity of plant species and functional groups of species in replicated plots within paired restored and remnant (relic) tallgrass prairies at three locations in central Texas, U.S.A.

A Modified Molybdenum Blue Method For Orthophosphate Determination Suitable For Investigating Enzymatic Hydrolysis Of Organic Phosphates, Zhongqi He, C. Wayne Honeycutt

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

In characterizing organic phosphorus (P_o) by phosphatase hydrolysis, the quantity of hydrolyzable P_o is represented by the difference in orthophosphate [i.e., inorganic P (P_i)] determined after and prior to enzymatic incubation. Therefore, precise determination of P_i is of major importance for accurate application of the enzymatic hydrolysis approach. The strong acid conditions required for conventional molybdenum blue methods interferes with P_i determination due to rapid hydrolysis of labile P_o and precipitation of enzymes (proteins). The molybdenum blue method of Dick and Tabatabai in 1977 reduced errors pertaining to nonenzymatic hydrolysis of P …

Comparison Of Protein Solubilization Methods Suitable For Proteomic Analysis Of Soybean Seed Proteins, Savithiry Natarajan, Chenping Xu, Thomas J. Caperna, Wesley M. Garrett

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

Extraction of soybean seed proteins for two-dimensional polyacrylamide gel electrophoresis (2D–PAGE) and mass spectrometry analysis is challenging and inconsistent. In this study, we compared four different protein extraction/solubilization methods—urea, thiourea/urea, phenol, and a modified trichloroacetic acid (TCA)/acetone—to determine their efficacy in separating soybean seed proteins by 2D–PAGE. In all four methods, seed storage proteins were well separated by 2D–PAGE with minor variations in the intensity of the spots. The thiourea/urea and TCA methods showed higher protein resolution and spot intensity of all proteins compared with the other two methods. In addition, several less abundant and high molecular weight proteins were …

Size-Dependent Feeding And Reproduction By Boll Weevil (Coleoptera: Curculionidae), S. M. Greenberg, D. W. Spurgeon, Thomas W. Sappington, M. Sétamou

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

The considerable variation in adult size of the boll weevil, Anthonomus grandis grandis Boheman, has been well documented, but the influences of adult size on reproductive rate are not known. We examined the relationship between the size of boll weevils and their feeding and oviposition. Weevils weighed to the nearest milligram were grouped into five categories based on pupal weight:≤5, 6-10, 11-15, 16-20, and>20 mg. Numbers of lifetime punctures produced in flower buds (squares) of cotton, Gossypium hirsutum L., by both sexes of adults tended to increase with pupal weight. Boll weevil females with pupal weights >10 mg produced …

Comparison Of Contact And Spatial Repellency Of Catnip Oil And N,N-Diethyl-3-Methylbenzamide (Deet) Against Mosquitoes, Ulrich R. Bernier, Kay D. Furman, Daniel L. Kline, Sandra A. Allan, Donald R. Barnard

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

Nepetalactone, the primary component of catnip oil, was compared with the repellent N,N-diethyl-3-methylbenzamide (deet) for its ability to affect the host-seeking ability of Aedes aegypti (L.). A triple cage olfactometer was used to bioassay each substance and to assess its attraction inhibition (spatial repellent) attributes when combined with the following attractants: carbon dioxide, acetone, a blend of L-lactic acid and acetone, and human odors. Repellent tests were conducted with each substance against female Ae. aegypti, Anopheles albimanus Weidemann, and Anopheles quadrimaculatus Say. Catnip oil and deet were both weakly attractive to Ae. aegypti, catnip oil was the better spatial …

Habitat Corridors Function As Both Drift Fences And Movement Conduits For Dispersing Flies, Joanna H. Fried, Douglas J. Levey, Jerome Hogsette

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

Corridors connect otherwise isolated habitat patches and can direct movement of animals among such patches. In eight experimental landscapes, we tested two hypotheses of how corridors might affect dispersal behavior. The Traditional Corridor hypothesis posits that animals preferentially leave patches via corridors, following them into adjacent patches. The Drift Fence hypothesis posits that animals dispersing through matrix habitat are diverted into patches with corridors because they follow corridors when encountered. House flies (Musca domestica L.), a species that prefers the habitat of our patches and corridors, were released in a central patch (100x100 m) and recaptured in peripheral patches …

Post-Release Evaluation Of Biological Control Of Bemisia Tabaci Biotype ‘‘B’’ In The Usa And The Development Of Predictive Tools To Guide Introductions For Other Countries, John A. Goolsby, Paul J. Debarro, Alan A. Kirk, Robert W. Sutherst, Luis Canas, Matthew A. Ciomperlik, Peter C. Ellsworth, Juli R. Gould, Diana M. Hartley, Kim A. Hoelmer, Steven E. Naranjo, Mike Rose, William J. Roltsch, Paul A. Ruiz, Charles H. Pickett, Don C. Vacek

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

Climatic matching and pre-release performance evaluation were useful predictors of parasitoid establishment in a retrospective analysis of a classical biological control program against Bemisia tabaci biotype ‘‘B’’ in the USA. Laboratory evaluation of 19 imported and two indigenous parasitoid species in quarantine on B. tabaci showed that the Old World Eretmocerus spp, had the highest attack rate. The climate matching program CLIMEX was used to analyze the establishment patterns of five Old World Eretmocerus spp. introduced to the Western USA. The top matches ±10% for the climate of the area of introduction and origin of the introduced parasitoids always included …

Is The Ability To Regenerate Damaged Skeletal Muscle Genetically Determined? : Can Allelic Variation In The Gene, Pax7, Explain Observed Differences In Recovery Of Force Following Damage By Eccentric Exercise?, Zoran Groznica

Theses : Honours

High force eccentric muscle actions, during forcibly lengthening contracting muscle, have been found to produce pronounced muscle damage, especially if exercise is unaccustomed. A cascade of events is initiated in order to repair damaged skeletal muscle tissue including degeneration and regeneration processes. For the duration of muscle regeneration, satellite cells are the primary source of new myoblasts in adult muscle. This process requires activation of quiescent mononucleated satellite cells which proliferate, differentiate and fuse together to form fully functional muscle fibres. The satellite cells are specified by the gene, Pax7, during development. Experimental studies of Pax7 null mice that lack …

The Status And Impact Of The Rainbow Lorikeet (Trichoglossus Haematodus Moluccanus) In South-West Western Australia, Tamara Chapman

Agriculture reports

This report provides a summary of the biology and ecology of the rainbow lorikeet (Trichoglossus haematodus moluccanus), examines the status and management of the rainbow lorikeet in other regions; assesses the threats posed by the feral population in south-west Western Australia; and formulates the aims and objectives for an integrated pest management program.

Step Workshops - Guide For Facilitators, Department Of Agriculture And Food, Western Australia

Agriculture reports

The STEP workshops can be run as independent modules or as part of the ?A Million Hectares for the Future? workshop series of which the overarching learning outcome is: Participants will be able to identify and make informed decisions to profitably manage salinity on their farms. Outlines the preferred pathway for the modules in the Million Hectares for the Future series.

Oceanographic Conditions And Diversity Of Sea Stars (Echinodermata: Asteroidea) In The Gulf Of California, México, Carlos E. Cintra-Buenrostro, Hector Reyes-Bonilla, Maria Dinorah Herrero-Perezrul

School of Earth, Environmental, & Marine Sciences Faculty Publications

Species richness is one of the best indicators of biodiversity. However, there are few investigations on concordance of diversity patterns and environmental settings for marine regions. The objectives of this study were to correlate species richness of shallow water (< 200 m deep) sea stars with key oceanographic factors in the Gulf of California, México, and to predict species richness of Asteroidea using multiple regressions. In these analyses the Gulf was divided into nine sections of one degree in latitude (from 23 - 31° N), at each section we recorded: continental shelf area (at 100 and 200 m depth), temperature mean and range at three depth levels (0, 60 and 120 m), thermocline depth, surface nutrient concentrations (nitrates, phosphates and silicates), surface photosynthetic pigment concentration, and integrated productivity. Sea star species richness at each latitudinal section was estimated from literature data, new collections and museum records. Species were assigned to one of the following feeding guilds: predators of small mobile invertebrates (I), detritivores (D), predators of colonial organisms (C), generalist carnivores (G), and planktivores (P). There are 47 shallow water asteroid species in the Gulf of California (16 I, 15 D, eight C, six G, one P and one not assigned). Total species richness and guild species richness showed strong latitudinal attenuation patterns and were higher in the southernmost Gulf, an area characterized by a narrow shelf, high temperature, and low nutrient concentrations. Species diversity for each guild was correlated to a set of oceanographic parameters: temperature, nitrate concentration, and integrated productivity were linked to richness in must cases. We detected that nutrients and surface pigments always presented negative relationships with species richness, indicating that productive environments limit asteroid diversity in the study area. Finally, the postulated regression models to estimate species richness from oceanographic data were significant and highly precise. We conclude that species richness of Asteroidea in the Gulf of California is related to oceanographic conditions and can be estimated from regional oceanographic information.

Long-Term Cardioprotection With Phosphodiesterase-5 Inhibition Against Ischemia-Reperfusion Injury: Role Of Nitric Oxide., Vladimir Paul Daoud

Theses and Dissertations

Recent studies have shown that the potent phosphodiesterase-5 (PDE-5) inhibitor, sildenafil citrate, induces a powerful cardioprotective effect against ischemia-reperfusion (I/R) injury in rabbit and mouse hearts. However, the effect of this drug in inducing long-term protection against I/R injury remains unknown. The goal of this study was to identify the duration of the protective window of sildenafil citrate as well as vardenafil, a more potent PDE-5 inhibitor. Rabbits were treated with sildenafil (0.7 mg/kg, iv), vardenafil (0.143 mg/kg), or an equivalent volume of saline. After 24 hrs, 48 hrs, 96 hrs, or 7 days of sildenafil treatment, the hearts were …

Identification Of The Pla2 Responsible For Prostanoid Synthesis In Response To Inflammatory Cytokines, Chaminda Fernando

Theses and Dissertations

Preliminary studies from our laboratory showed that cPLA2α may be responsible for approximately 50-60% of the PGE2 production in response to inflammatory cytokines. Thus, we hypothesized that a closely-related PLA2 is responsible for 40-50% of the PGE2 produced in response to inflammatory cytokines. To this end, we utilized RNAi technology, extensively optimized, to down regulate the expression of closely-related isoforms of phospholipase A2 in A549 cells and used an enzyme linked immuno sorbent assay (ELISA) to quantitate the PGE2 produced. These studies found that cytosolic phospholipase A2α (cPLA2α) regulated 97.7% of the prostaglandin E2 (PGE2) produced in response to inflammatory …

Correlation Between Bioassessments Of Macroinvertebrates And Fishes And Natural Land Cover In Virginia Coastal Plain Watersheds, Warren Hunter Smigo

Theses and Dissertations

Twenty five first through third order streams in the Coastal Plain of Virginia were sampled for benthic macroinvertebrates and fishes to determine whether a predictable relationship between areas of Unfragmented Natural Land Cover (UNLC) and biotic integrity could be established. I hypothesized that as the area of UNLC increased in a watershed at either the whole catchment or riparian scale, biotic indices measuring stream water and habitat quality would increase. Biotic integrity was measured through the scores from the Coastal Plain Macroinvertebrate Index (CPMI) for benthic macroinvertebrates and the VCU Index of Biotic Integrity (IBI) for fishes. Using GIS, the …

Molecular Identification Of Anopheles Spp. (Diptera: Culicidae) In The Chapare/Carrasco Valleys, Cochabamba, Bolivia, Corey Brelsfoard

Masters Theses

Studies on malaria in our "backyard," the Neotropics, have been hampered by the lack of an accurate means of species identification for mosquito vectors of the human malaria parasite (i.e. Plasmodium spp). Mosquitoes in the genus Anopheles are the principle malaria vectors in the Neotropics and are often composed of closely related morphologically similar species complexes. This thesis describes three polymerase chain reaction (PCR) protocols to aid in identifying four anopheline mosquitoes for any life stage, of which three have been incriminated as vectors of human malaria in several locations throughout S. America and might be potential vectors of human …

An Evaluation Of Beaver Habitat Models For Illinois Rivers, Daniel R. Cox

Masters Theses

Beavers (Castor canadensis) are agents of landscape change, altering the structure and species composition of vegetative communities through herbivory and water impoundment. To better manage beavers in Illinois, improved methods of monitoring riverine populations of this species are needed. The objectives of the study were to (1) locate, map and quantify the spatial distribution of beaver colonies along the Embarras River, (2) test the efficacy of 2 existing beaver habitat models, the U.S. Fish and Wildlife Service's Habitat Suitability Index (HSI) model and Missouri's beaver habitat model, for predicting the relative density of beavers and (3) develop a new multiple …

The Effects Of Habitat Quality On Abiotic Factors And Heterotrophic Microbial Activity In A Freshwater Stream System, Daphne Kampinga

Masters Theses

Much of the Midwest, as well as Illinois' landscape, has largely been transformed from its original habitat of prairie, savanna, wetlands, and forest into corn and soybean fields and urban areas. As a result, less than 1% of the original habitat in Illinois remains intact today. These modifications can lead to habitat fragmentation and affect riparian zone vegetation, which is an important link between the land-water interface and influences processes such as organic matter inputs and water temperature regimes. As a result of fragmentation, riparian zone loss has occurred and catchment vegetation associated with streams can vary from agricultural fields, …

Landscape Effects On Stream Water Chemistry And Benthic Productivity In An Agricultural Watershed, Shari E. Fanta

Masters Theses

A conceptual model was developed and utilized to investigate the influence of land use/land cover on community metabolism as mediated by stream water chemistry, in an agricultural watershed in east-central Illinois. A suite of physical and chemical variables were sampled over a yearlong period at twelve sites across the Hurricane Creek Watershed. Community metabolism was determined at five of the sites during episodes of suitable hydrologic and weather conditions. A single PCA axis was unique in incorporating significant relationships between land use/land cover, stream water chemistry, as well as community metabolism, thereby validating the conceptual model. The proportion of cropland, …

Copulatory Behaviors Of Male Caribbean Fruit Flies (Anastrepha Suspensa) And Female Sperm Storage Patterns, Holly J. Wallace

Masters Theses

Countless numbers of insects have copulatory behaviors performed while in copulation. Copulatory behaviors or copulatory courtship performed by males may be a means to influence female sperm storage patterns. Sexual selection in regards to female processes that influence male reproductive success are termed "cryptic female choice." In my thesis I examined copulatory behaviors performed by mass-reared male Anastrepha suspensa and sperm storage patterns in relation to male behavioral performance in females. I videotaped copulating virgin males and females of different ages and recorded mating duration, size of both sexes, male proboscis extensions, male probing of the females' head, thorax and …

Plant Species Turnover As A Mechanism Of Community Change In Response To Biotic And Abiotic Perturbation, Kathryn Anne Yurkonis

Masters Theses

Plant communities change through time as species respond to changes in their biotic and abiotic environment. Biotic factors influencing plant communities can include species invasion, competition, or herbivory, whereas abiotic factors can include drought, fire, or nutrient deposition. Although factors influencing community structure have been extensively documented, the mechanisms by which communities respond to disturbances are not well understood. To address this problem, my thesis research considered two perturbations, exotic species invasion and drought, in each case I specifically relate species turnover to changes in community structure. The overall goal of this project was to evaluate the utility of using …

Common Names For The Frog Genus Leptodactylus (Amphibia, Anura, Leptodactylidae), Ulisses Caramaschi, Rafael O. De Sá, W. Ronald Heyer

Biology Faculty Publications

Most species of the frog genus Leptodactylus lack common names. Common names are those names used by different human cultures and societies for the species of animals and plants where humans and biota reside together. Often times common names are lacking for Neotropical frogs or are broad in scope. For example, indigenous people may have a single name for frogs that occur on the ground and another name for frogs that occur in shrubs and trees, even though there are many species of ground frogs called by the same name as well as for the tree frogs. Sometimes colonists have …

Invertebrate Diversity In Taylor Valley Soils And Sediments, Amy M. Treonis, Diana H. Wall, Ross A. Virginia

Biology Faculty Publications

Explaining how ecosystems function across variable landscapes will require knowledge of biodiversity patterns. In particular, biodiversity studies of soils and sediments will help in understanding the linkages between ecosystem processes in both of these habitats (Freckman et al. 1997). Soils and sediments are domains for ecosystem processes such as decomposition and trace gas exchange. There are few studies, however, that have compared abundance and diversity of organisms in adjacent soils and sediments (Freckman et al. 1997). The goal of this study was to increase understanding of how the biotic communities involved in ecosystem processes are organized within an important feature …

Crisis Global De Biodiversidad: Importancia De La Diversidad Genética Y La Extinción De Anfibios, Rafael O. De Sá

Biology Faculty Publications

El mundo enfrenta, por primera vez desde el comienzo de la civilización, el declive y la extinción de una clase de vertebrados, los anfibios. Esta extinción aparenta ser un evento global y de la magnitud que llevó a la desaparición de los dinosaurios. Muchas son las posibles causas de esta extinción y el efecto combinado de estos factores agravan la situación. La pérdida de ambientes naturales permanece como el factor más crítico en el declive de anfibios, pero enfermedades infecciosas emergentes parecen ser responsables de mortalidades masivas en décadas recientes. El declive y extinción de anfibios representa una llamada urgente …

Are Leptodactylus Didymus And L. Mystaceus Phylogenetically Sibling Species (Amphibia, Anura, Leptodactylidae)?, Rafael O. De Sá, W. R. Heyer, A. Camargo

Biology Faculty Publications

The Leptodactylus fuscus species group consists of 25 currently recognized species; within this species group and distributed throughout the Amazon Basin, Atlantic Forests, Gran Chaco, and cerrados is the L. mystaceus species complex. This species complex consists of L. didymus, L. elenae, L. mystaceus, L. notoaktites, and L. spixi. Adult morphologies have been used to distinguish these species from each other except for L. didymus and L. mystaceus (Heyer, 1978; Heyer et al., 1996). Leptodactylus didymus and L. mystaceus are morphologically indistinguishable; the species are recognizable only by the characteristics of their advertisement calls: non-pulsed in L. didymus and pulsed …

On The Enigmatic Distribution Of The Honduran Endemic Leptodactylus Silvanimbus (Amphibia: Anura: Lep Todactylidae), W. Ronald Heyer, Rafael O. De Sá, Sarah Muller

Biology Faculty Publications

Most species of the frog genus Leptodactylus occur in South America, and all authors who have treated the zoogeography of the genus have concluded that it originated somewhere in South America (e.g., Savage 1982). Savage (1982,518) summarized the historical herpetofaunal units of the Neotropics as follows: "All evidence points to an ancient contiguity and essential similarity of a generalized tropical herpetofauna that ranged over tropical North, Middle, and most of South America in Cretaceous-Paleocene times. Descendents of this fauna are represented today by the South and Middle American tracks (Elements). To the north of this fauna ranged a subtropical-temperate Laurasian …

Diet Composition Of Juvenile Fish Reflects Adaptation To Altered Prey Communities In A Reservoir Receiving Thermal Effluent, Brian A. Metzke

Masters Theses

Survival, and ultimately recruitment. of planktivorous juvenile fish is related to prey availability. Temperature regime and introduction of exotic species can change zooplankton community dynamics and alter trophic relationships between juvenile fish and their prey. Newton Lake, located in Jasper County, Illinois is used as a cooling reservoir for a coal burning power plant. Thermal effluent produced by the power plant is released into only one of two reservoir arms creating a temperature gradient. Newton Lake also contains Daphnia lumholtzi, an exotic zooplankter thought to create feeding difficulties for gape-limited predators like juvenile fish. It is within the context of …

Development Of A Process Of Addition Of Tricalcium Phosphate From Burnt Phosphate Rock In Feed For Animal Nutrition, Luis Fernando Nogales Grágeda

Theses and Dissertations

This study took place in Bolivia with the purpose of using thermally treated Capinota phosphate rock as a phosphorous supplement in balanced feed diets. The objective was to produce a natural phosphate substance that would be more easily accessible to the local population than commercial feed supplements. An additional objective of this study was to increase the availability of the low-fluoride phosphorous. The biological assays indicated that the diet with the added burned phosphoric rock produced similar yields to those using a commercial feed supplement (dicalcium phosphate). This indicates that the locally manufactured product, by partial acidification, can compete with …

The Body Eclectic: Viewing Bodily Modification In David Nebreda, David Houston Jones

Reconstruction: Studies in Contemporary Culture

[First paragraph]

David Nebreda's work presents current thinking on body/performance art with a dilemma. In stretching social prescriptions of the (re)presentable body, it exemplifies a pervasive anxiety concerning bodily modification and the politics of looking, and demands a new theorisation of the body in photographic representation. Autoportraits (2000) depicts a series of visibly emaciated bodies on which wounds are inflicted by knives, cords and flames [1]. The photographs document the strict schedules of discipline to which the bodies are subjected, and sometimes represent the very moment at which practices of bodily modification are executed. It is this subject-matter which threatens …

The Drosophila Lymph Gland As A Developmental Model Of Hematopoiesis, Seung Hye Jung, Cory J. Evans, Christine Uemura, Utpal Banerjee

Biology Faculty Works

Drosophila hematopoiesis occurs in a specialized organ called the lymph gland. In this systematic analysis of lymph gland structure and gene expression, we define the developmental steps in the maturation of blood cells (hemocytes) from their precursors. In particular, distinct zones of hemocyte maturation, signaling and proliferation in the lymph gland during hematopoietic progression are described. Different stages of hemocyte development have been classified according to marker expression and placed within developmental niches: a medullary zone for quiescent prohemocytes, a cortical zone for maturing hemocytes and a zone called the posterior signaling center for specialized signaling hemocytes. This establishes a …