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Articles 4291 - 4320 of 5010

Full-Text Articles in Life Sciences

Phylogenetic History, Morphological Parallelism, And Speciation In A Complex Of Appalachian Salamanders (Genus: Desmognathus), Nathan D. Jackson Mar 2005

Phylogenetic History, Morphological Parallelism, And Speciation In A Complex Of Appalachian Salamanders (Genus: Desmognathus), Nathan D. Jackson

Theses and Dissertations

Understanding the mechanisms that generate shared morphologies across closely related taxa is important when identifying distinct evolutionary lineages using morphological characters. Desmognathus salamanders are an ideal group for testing hypotheses concerning the correlation between morphological similarity and genetic exchange within and among nominal species due to a pattern of high discordance between the two. Phylogeographic hypotheses are tested for populations of the D. quadramaculatus species complex throughout southern Appalachia by combining phylogenetic and population genetic methods with geographical information. Phylogenetic and phylogeographic inferences are then assessed in conjunction with morphological characteristics that have traditionally diagnosed taxonomic entities to understand the …

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The Effect Of Religiosity And Spirituality On Transformatinal Leadership Characteristics Of Hospital Food And Nutrition Managers, Anna Naegle Sarver Mar 2005

The Effect Of Religiosity And Spirituality On Transformatinal Leadership Characteristics Of Hospital Food And Nutrition Managers, Anna Naegle Sarver

Theses and Dissertations

Effective leadership in the field of dietetics is becoming increasingly vital in a rapidly changing world. A determination of factors which impact leaders and their followers is essential. This study was designed to examine the relationship between religiosity and spirituality and transformational leadership characteristics of hospital food and nutrition managers as rated by self as well as by those directly supervised by the managers. The influence of religious and spiritual beliefs on the workplace and workplace practices was also examined. Respondents were selected from the American Hospital Association database. Hospitals from 250 to 499 beds were included. Directors of Foodservice …

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In Vitro Toxicity Of Cadmium Oxide Particles In Brl 3a Rat Liver Cells, Janice M. Shelley Mar 2005

In Vitro Toxicity Of Cadmium Oxide Particles In Brl 3a Rat Liver Cells, Janice M. Shelley

Theses and Dissertations

For the last decade or so, in vitro toxicology has been studied as a method for determining human toxicity, as well as hazard identification and characterization. One purpose of in vitro studies is to determine the possibility of developing systems in which the toxicity of chemicals can be quantified, without heavy reliance on animal experimentation. Specific data pertaining to cadmium toxicity in humans through use of in vitro methods and models is sparse, at best. There is a need to complete more studies and collect more data to study particular chemicals and their effects and to complete proper evaluation and …

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Calorespirometric Evidence For Adaptation Of Blackbrush And Shadscale To Growth Season Temperatures In Cold Deserts, Heidi A. Summers Feb 2005

Calorespirometric Evidence For Adaptation Of Blackbrush And Shadscale To Growth Season Temperatures In Cold Deserts, Heidi A. Summers

Theses and Dissertations

Coleogyne ramosissima Torr. (blackbrush) and Atriplex confertifolia [Torr. & Frem.] Wats. (shadscale) are cold desert shrubs from different families that often grow together in the Great Basin and the Colorado Plateau in the life zone between 800 and 2000 m elevation. Tissue and seeds from the two species were collected from several localities. Metabolic heat and carbon dioxide production rates were measured with calorespirometry on tissue from field-grown plants and on seedlings at temperatures from 5 to 35°C at 5°C intervals. Blackbrush adapts to higher temperatures earlier than does shadscale, and once it has adjusted to higher temperatures, anabolic rates …

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Metabolic Profile And Live Weight Of Male Llamas (Lama Glama) Fed With Barley Hay, Alfalfa, And Quinoa Scrub, Karla Coaquira Arratia Jan 2005

Metabolic Profile And Live Weight Of Male Llamas (Lama Glama) Fed With Barley Hay, Alfalfa, And Quinoa Scrub, Karla Coaquira Arratia

Theses and Dissertations

In recent years llamas have attracted great national and international interest for their qualities of human food production, fiber production for high-quality textiles, and for being an ecological animal. These qualities have allowed a resurgence of cultivating them for commercial ends. One of the principal limits is secure food for allowing a constant, sustainable growth. The objective of this study was to evaluate the metabolic profile and live weight of male llamas (Lama glama) fed with barley hay, alfalfa hay, and quinoa scrub. The fieldwork occurred in metabolic chambers in a closed environment at the demonstration farm of the Benson …

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Feed Conversion Index In Two Populations And Two Lines Of Guinea Pigs For Meat Production, Kathia Jordán Vargas Jan 2005

Feed Conversion Index In Two Populations And Two Lines Of Guinea Pigs For Meat Production, Kathia Jordán Vargas

Theses and Dissertations

The guinea pig (Cavia aperea porcellus) is an alternative to improve human nutrition because its meat is of excellent taste and quality. Thus, it is an important nutritional source. The feed conversion index was determined under the basic (forage) and mixed (forage and concentrate) diets during the growth phase. This was done with both sexes located in the Tamborada and MEJOCUY populations, using the AUQUI, and San Luis lines. This was done in order to quantify how many kilograms of feed an animal must eat to gain one kilogram of live weight. The animals were randomly distributed into individual pools …

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Apparent Digestibility In Llamas (Lama Glama) Fed With (Stipa Ichu) Treated With Urea And Molasses At The C.E.A.C., Ninfa Jacqueline Magne Colque Jan 2005

Apparent Digestibility In Llamas (Lama Glama) Fed With (Stipa Ichu) Treated With Urea And Molasses At The C.E.A.C., Ninfa Jacqueline Magne Colque

Theses and Dissertations

The following work was conducted at the Agricultural Experimental Center under the title of : Apparent digestibility in llamas feed with stipa ichu (Peruvian feather grass) treated with urea and molasses, for which 3 assays were performed in reference to the study : 1) percentage of assimilation of the treated and non- treated grass, 2) apparent digestibility of fiber and protein after and before feeding, and 3) determine the adequate levels of urea and molasses for the chemical treatment of the grass (Stipa ichu). For the first assay, the greater consumption was obtained at the level of 3 (3% of …

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Living Digestibility Of Alfalfa And Barley In Llamas (Lama Glama) In The Agricultural Experimental Center Condoriri, Adelaida Alarcon Chuquichambi Jan 2005

Living Digestibility Of Alfalfa And Barley In Llamas (Lama Glama) In The Agricultural Experimental Center Condoriri, Adelaida Alarcon Chuquichambi

Theses and Dissertations

The following investigation was carried out in the Agricultural Experimental Center Condoriri (CEAC), dependent on the Faculty of Agricultural Livestock Sciences and Veterinary Medicine, located to the North of the Province border of the Department of Oruro, a distance of 12 km from the town of Caracollo and 49 km from the city of Oruro. The production of llamas and alpacas in our country is an activity of ecological, social, and especially ecological importance for Andean inhabitants. In nutrition, the fundamental factor is the power of absorption; this is because the yield of animal production depends on the quantity and …

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In Vivo Digestibility In Llamas (Lama Glama), Fed With Barley And Paja Brava At The C.E.A.C., Martha Jesusa Llanos Pérez Jan 2005

In Vivo Digestibility In Llamas (Lama Glama), Fed With Barley And Paja Brava At The C.E.A.C., Martha Jesusa Llanos Pérez

Theses and Dissertations

The Highlands of Bolivia present a great diversity of native botanical species with strong forage characteristics, providing them with a considerable potential for usage as a resource in the feeding of cattle. The following work was performed with the idea of taking advantage of the zone’s native species as a source for the feeding of llama cattle. In order to accomplish it, we took into consideration the following variables: food consumption, water consumption, amount of fecal excretions, urine volume, body weight, and the digestibility of the nutrients found in the food prepared with paja brava and barley (ash, protein, fiber, …

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Evaluation Of The Agronomic Performance Of Six Varieties Of Peanut (Arachis Hypogaea L.) In The St. Felix Community Of The Coroico Township (Nor Yungas-La Paz), Viviana Marleni Quisbert Jan 2005

Evaluation Of The Agronomic Performance Of Six Varieties Of Peanut (Arachis Hypogaea L.) In The St. Felix Community Of The Coroico Township (Nor Yungas-La Paz), Viviana Marleni Quisbert

Theses and Dissertations

The peanut is an important crop in most countries due to its industrial, nutritional, and pedological potential. It grows well in subtropical areas. This study was planned based on the weather characteristics of the Yungas and the St. Felix community. A completely randomized block design with 6 treatments and 3 repetitions was used. An analysis of variance and a Tukey test were used for statistical analysis of the variables. With respect to time required for maturation, the Coloradito Palmar variety was most premature with a time of 134 days while the Local variety took 177 days to mature, which is …

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Agronomic Performance Of Two Baby Lettuce Varieties (Lactuca Sativa L.) At Three Planting Densities Using Panqar Huyus In The Ingavi Province, Francisco Javier Orruel Fusco Jan 2005

Agronomic Performance Of Two Baby Lettuce Varieties (Lactuca Sativa L.) At Three Planting Densities Using Panqar Huyus In The Ingavi Province, Francisco Javier Orruel Fusco

Theses and Dissertations

This study was conducted in the experimental unit of the Benson Agriculture and Food Institute, which is located in the Letanias community of the Ingavi province in the department of La Paz. Our objective was to compare the agronomic performance of two baby lettuce varieties (Lactuca sativa L.) at three planting densities in panqar huyus. In order to provide the rural farmer communities of Contorno Letanias and Contorno Medio a possible cost-effective alternative and to employ the use of moderate environments called panqar huyus, we introduced two varieties of baby lettuce: 1) Little Gem in seed form and 2) Tom …

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Brucellosis In Alpacas (Lama Pacos) In Communities Of The City Ulla Ulla, Franz Tomayo Province, Department Of La Paz, Macario Suxo Blanco Jan 2005

Brucellosis In Alpacas (Lama Pacos) In Communities Of The City Ulla Ulla, Franz Tomayo Province, Department Of La Paz, Macario Suxo Blanco

Theses and Dissertations

This investigation was performed in the Altiplano Altoandino sub-humid region in the Ulla Ulla district, Pelechuco township, Franz Tomayo province, department of La Paz, Bolivia. The objective of this study was to quantify and compare the presence of Brucellosis in male and female alpacas (Lama pacos) at ages 2, 3, 4, 5, 6, and 7 years. Blood samples were taken from the jugular vein of 500 alpacas from the Hichucollo, Huacuchani, Ucha Ucha, and Ulla Ulla communities. The serum from each sample was separated and a serological diagnosis was performed by rapid agglutination with Rose Bengal chemical stain. In the …

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Replacement Of Fish Meal By Meal Worm (Eisenia Foetida) In The Feed Of Broilers As An Alternative Source Of Protein, Carlos ÁNgel Cervantes Cevallos Jan 2005

Replacement Of Fish Meal By Meal Worm (Eisenia Foetida) In The Feed Of Broilers As An Alternative Source Of Protein, Carlos ÁNgel Cervantes Cevallos

Theses and Dissertations

This investigation was conducted in the rural community of Cuambo, located in the northeast of Imbabura province, in the Mira river basin of Salina parish, at 1530 meters above sea level and with an average temperature of 19 C. The principal objective of this investigation was to evaluate the effect of four levels of substitution of fish meal for earthworm meal in broiler chicken diets. The fieldwork occurred in two stages over the course of 20 months: A. Creation of the feed: This step lasted from the installation of an earthworm culturing area through the cultivation, harvest, and drying of …

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Biochemical And Molecular Nutrition Blocks As Dietary Supplements In Llamas (Lama Glama) In The Last Third Of The Gestation Period Of The Ceac, Janette Illanes Callejas Jan 2005

Biochemical And Molecular Nutrition Blocks As Dietary Supplements In Llamas (Lama Glama) In The Last Third Of The Gestation Period Of The Ceac, Janette Illanes Callejas

Theses and Dissertations

The present work consisted in the use of biochemical and molecular nutrition blocks (BMN) in llamas during the last third of the gestation period, at the Agricultural Experiment Center of Condori (CEAC), located 49 km north of the city of Oruro, and 12 km north of the Caracollo population, in the province of Cercado. For this research work, we used 20 pregnant llamas in the last third of their gestation period, between the ages of 2 and 3 years old, 10 of which belonged to the Khara breed, and 10 to the Thampulli breed. Two corrals of 7 x 7 …

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Agronomical Evaluation Of Six Species Of Forage Grass Tolerant To Salinity In The Tamborada Region, Bladimir Vargas Rojas Jan 2005

Agronomical Evaluation Of Six Species Of Forage Grass Tolerant To Salinity In The Tamborada Region, Bladimir Vargas Rojas

Theses and Dissertations

Six forage grass species from the United States were evaluated for salinity tolerance and growth performance. A randomized block design was used with six repetitions of five furrows each to maintain experimental consistency. The study was conducted in the Tamborada region of Cochabamba, Bolivia from December 2003 through June 2004. Results indicated that significant differences exist between species (Pr<0.01). The species Elymus cinereus and Agropyron elongatum demonstrated the best performance regarding plant height, achieving heights of 35.4 cm and 32.7 cm respectively. Festuca arundinacea and Agropyron elongatum obtained larger percent coverage than the other species with 79.59% and 76.53% respectively. These species also exceed the others in production of green forage (1500.00 kg/ha and 13985.80 kg/ha) as well as in production of dry matter (5000.70 kg/ha and 4862.85 kg/ha). They are recommended for production in the region of Tamborada, Cochabamba, Bolivia.

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Novel Strategies In Cardioprotection Against Ischemia/Reperfusion Injury, Fadi N. Salloum Jan 2005

Novel Strategies In Cardioprotection Against Ischemia/Reperfusion Injury, Fadi N. Salloum

Theses and Dissertations

Cell damage represents a major pathomechanism in many diseases of high clinical interest, such as myocardial infarction (MI), where it plays an important role in ischemia-reperfusion (I/R) injury. Considerable progress has been made towards identifying physiological and pharmacological agents that play a key role in myocardial preconditioning against I/R injury and also elucidating the molecular changes leading to such protection.Second messengers in cellular signaling pathways, such as cGMP have been well implicated as key players in ischemic and pharmacological preconditioning (PC) of the heart. Phosphodiesterase type 5 (PDE-5) is an enzyme that specifically hydrolyzes cGMP thereby decreasing its tissue concentration. …

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Erythrocyte-Associated Transients In Capillary Po2 In The Rat Spinotrapezius Muscle During Hemodilution With Hespan And A Hemoglobin-Based Oxygen Carrier, Matthew Barker Jan 2005

Erythrocyte-Associated Transients In Capillary Po2 In The Rat Spinotrapezius Muscle During Hemodilution With Hespan And A Hemoglobin-Based Oxygen Carrier, Matthew Barker

Theses and Dissertations

Hemoglobin-based oxygen carriers for use as transfusion fluids have emerged as a leading technology directed at stemming shortages of a safe blood supply and providing a readily available resuscitation fluid in various trauma situations. The purpose of this investigation was to determine the effects of isovolemic hemodilution with Hespan and a hemoglobin-based oxygen carrier (HBOC) on erythrocyte-associated transients (EATs) in capillary PO2. The particulate nature of blood flow in capillaries, when observed from a stationary observation point, results in fluctuations of PO2 as alternating red blood cells and plasma gaps move through the detection region. Therefore, through experimental methods which …

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Cytokine And Chemokine Profiles In A Rat Model Of Hemorrhagic Shock After Immuno-Modulation By Androstenetriol, Kristin E. Paccione Jan 2005

Cytokine And Chemokine Profiles In A Rat Model Of Hemorrhagic Shock After Immuno-Modulation By Androstenetriol, Kristin E. Paccione

Theses and Dissertations

Further understanding of the cellular and molecular mechanisms involved in traumatic injury, and how they are modulated during drug interaction, can facilitate novel treatment strategies for future trauma patients. We hypothesize that the pharmacological agent, Androstenetriol (AET), up regulates host immune response by modulating the continued expression of mediators, including cytokines. In a double-blinded experiment, rats were hemorrhaged, driven by volume or pressure conditions, then resuscitated with fluids and packed red blood cells following a subcutaneous injection of either vehicle or drug. Blood was collected at various time points and cytokine levels were determined by analyses with both multiplex and …

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Identification Of The Rna Cis-Elements That Interact With Srp30a To Regulate The Alternative Splicing Of Caspase 9 Pre-Mrna, Prabhat Mukerjee Jan 2005

Identification Of The Rna Cis-Elements That Interact With Srp30a To Regulate The Alternative Splicing Of Caspase 9 Pre-Mrna, Prabhat Mukerjee

Theses and Dissertations

Studies have shown that the alternative splicing of caspase 9 and the phospho-status of SR proteins, a conserved family of splicing factors, are regulated by chemotherapy and de novo ceramide via the action of protein phosphatase-1 (PP1). Two RNA splice variants are derived from the caspase 9 gene, pro-apoptotic caspase 9a and anti-apoptotic caspase 9b, via alternative splicing by either the inclusion or exclusion of an exon 3, 4, 5, and 6 cassette. In this study, the link between SR proteins and the alternative splicing of caspase 9 was established. Sequence analysis of the exon 3, 4, 5, and 6 …

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Seasonal And Spatial Variation In Leaf Area Index, Litter Production, And Light Levels In Myrica Cerifera,Shrub Thickets Across A Barrier Island Chronsequence, Steven T. Brantley Jan 2005

Seasonal And Spatial Variation In Leaf Area Index, Litter Production, And Light Levels In Myrica Cerifera,Shrub Thickets Across A Barrier Island Chronsequence, Steven T. Brantley

Theses and Dissertations

Leaf area index (LAI), litter production and understory light levels of Myrica cergera shrub thickets were assessed on Hog Island, Virginia to quantify spatial and seasonal variations in leaf area and light attenuation among four thickets representing a successional chronosequence and compare methods of estimating LA1 in shrub- dominated systems. Seasonal LA1 estimates were made seven times throughout the year with a portable integrating radiometer (Li-Cor LAI-2000) and three times by measurement of photosynthetically active radiation (PAR) and use of the Beer-Larnbert law. Leaf area index was also estimated through leaf litter collection and use of allometric relationships between stem …

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Modulation Of Gene Expression By Tumor-Derived Mutant P53. Role Of Transactivation In Gain-Of-Function., Mariano J. Scian Jan 2005

Modulation Of Gene Expression By Tumor-Derived Mutant P53. Role Of Transactivation In Gain-Of-Function., Mariano J. Scian

Theses and Dissertations

It was hypothesized that the C-terminal sequences for mutant p53 would be required for oligomerization. and oligomerization may be critical for gain-of-function. An N-terminal deletion mutant of p53 that deletes amino acids 1-293 was used as a tool to perform hetero-oligomerization studies. This mutant retains the entire oligomerization domain but dispenses off the transactivation domain and a large portion of the sequence- specific DNA-binding domain. Co-transfection experiments show that p53 del. 1-293 forms hetero-oligomeric complexes with p53-D281G. Also. co-expression of p53 del. 1- 293 with p53-D281G inhibited p53-D28lG-mediated transactivation of the EGFR and MDRl promoters suggesting that hetero-oligomerization inactivates transcriptional …

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Effect Of The Use Of Amaranth (Amaranthus Spp.) Leaf Flour In The Creation Of Feeds For The Production Of Broiler Chickens, Wendy Valeria Quel Ruíz Jan 2005

Effect Of The Use Of Amaranth (Amaranthus Spp.) Leaf Flour In The Creation Of Feeds For The Production Of Broiler Chickens, Wendy Valeria Quel Ruíz

Theses and Dissertations

This investigation was conducted in the rural community of Cuambo, located in the northeast of the province of Imbabura, in the Mira river basin of Salinas parish, at 1530 meters above sea level and with an average temperature of 19.5° C. The main objective of this investigation was to analyze the effect of using amaranth (Amaranthus) leaf flour in the creation of feeds for broiler chickens. The field work occurred during 12 months and consisted of two phases: A. Creation of the feed: This proceeded from the cultivation, cutting, and drying of amaranth until the obtaining of the flour and …

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Long-Term Cardioprotection With Phosphodiesterase-5 Inhibition Against Ischemia-Reperfusion Injury: Role Of Nitric Oxide., Vladimir Paul Daoud Jan 2005

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 …

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Identification Of The Pla2 Responsible For Prostanoid Synthesis In Response To Inflammatory Cytokines, Chaminda Fernando Jan 2005

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 …

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Correlation Between Bioassessments Of Macroinvertebrates And Fishes And Natural Land Cover In Virginia Coastal Plain Watersheds, Warren Hunter Smigo Jan 2005

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 …

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Development Of A Process Of Addition Of Tricalcium Phosphate From Burnt Phosphate Rock In Feed For Animal Nutrition, Luis Fernando Nogales Grágeda Jan 2005

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 …

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Genetic Variability, Pathogen Susceptibility, Subspecies Identity And Conservation Of The Endangered Northern Flying Squirrel (Glaucomys Sabrinus) In Virginia, James Lincoln Sparks Jr. Jan 2005

Genetic Variability, Pathogen Susceptibility, Subspecies Identity And Conservation Of The Endangered Northern Flying Squirrel (Glaucomys Sabrinus) In Virginia, James Lincoln Sparks Jr.

Theses and Dissertations

I examined the population genetic structure of three known subspecies of Glaucomys sabrinus from Appalachia, Washington State, and two previously unexamined populations from Mount Rogers National Recreation Area (MRNRA) in Southwestern Virginia. Mean FST (0.107) and an AMOVA (P G. sabrinus subspecies populations in the southern Appalachians are genetically differentiated. Glaucomys sabrinus at MRNRA were less inbred than expected. Gene flow, a consensus tree based on Nei's genetic distance, elevated heterozygosity and morphometric data suggest that the MRNRA G. sabrinus population is an intergrade of the two recognized Appalachian subspecies, G. s. fuscus and G. s. coloratus. I compared inbreeding …

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Material And Acoustic Properties Of Swimbladders Of Tilapia And Channel Catfish, Mohammed Ali Nawaz Jan 2005

Material And Acoustic Properties Of Swimbladders Of Tilapia And Channel Catfish, Mohammed Ali Nawaz

Theses and Dissertations

Acoustically, teleost swimbladders have been considered resonant underwater bubbles. Contrary results indicating that bladders are tuned less sharply than such a bubble have been explained by damping of surrounding fish tissue. Recent findings in toadfish and weakfish, however, suggest that the bladder is a highly damped structure and that the frequency of the fish sounds is deternlined as a forced response to sonic muscle movement rather than by resonance of the bladder. In this study I examined acoustics and material properties of swimbladders in Tilapia (an auditory generalist) and the channel catfish (an auditory specialist). The swimbladder was struck with …

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Habitat Selection In Four Sympatric Small Mammal Species And The Effects Of Potential Predators On Peromyscus Leucopus, Adam Daniel Chupp Jan 2005

Habitat Selection In Four Sympatric Small Mammal Species And The Effects Of Potential Predators On Peromyscus Leucopus, Adam Daniel Chupp

Theses and Dissertations

I examined the effects of potential predators in relation to habitat selection in Peromyscus leucopus. I also examined habitat selection in three other sympatric species (Blarina brevicauda, Blarina carolinensis, Sorex longirostris). I utilized data fiom 49 sampling sites on National Park Service land; Petersburg National Battlefield Eastern Front Unit (15), Five-Forks Unit (17), Appomattox Court House National Historical Park (15) and Booker T. Washington National Monument (12). Sites were categorized by location (park unit) and habitat type (i.e. bottom-land hardwood), and the microhabitat within each sampling site was characterized by four variables (% cover of grasses, herbs, shrubs, and volume …

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The Effect Of Red Blood Cell Velocity On Oxygenation Measurements Using Resonance Raman Spectroscopy, Derrick Williams Jan 2005

The Effect Of Red Blood Cell Velocity On Oxygenation Measurements Using Resonance Raman Spectroscopy, Derrick Williams

Theses and Dissertations

Resonance Raman spectroscopy can be used to estimate the hemoglobin oxygen saturation. Previous studies have demonstrated that exposure of oxygenated red blood cells to laser illumination may result in photo-induced displacement of oxygen from hemoglobin. In this study, an in vitro model was used to evaluate the relationship between this photo-induced effect and the red blood cell velocity. A computer-controlled system was implemented to acquire variables such as red cell velocity, microvessel diameter and hemoglobin oxygen saturation at multiple sites in selected microvascular networks. Using this system, resonance Raman spectroscopy was employed to measure hemoglobin oxygen saturation gradients in arterioles …

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