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1999

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Full-Text Articles in Life Sciences

The Effect Of Shelterwood-Cut Oak Forestry Practices On Breeding Bird Success, Patrick Lee Collins Dec 1999

The Effect Of Shelterwood-Cut Oak Forestry Practices On Breeding Bird Success, Patrick Lee Collins

Theses & Honors Papers

Populations of breeding birds were studied on two shelterwood-cut oak stands in Buckingham County, Virginia. These two tracts, Harris East and Harris West, were cut in 1996 and a Breeding Bird Census has been conducted on these tracts since 1997. This study is part of an ongoing effort to collect pre-bum data, and document the diversity of avian species utilizing this habitat. The changes in avian species present on the Harris East and Harris West plots is important to know so that the effects of shelterwood-cut forestry practices can be understood better. The data collected showed that, by changing the …


A Study On The Relationship Between Eggshell Color, Egg Specific Gravity, And The Cuticle Of The Eggs Of Broiler Breeds, Byron Anthony Connor Dec 1999

A Study On The Relationship Between Eggshell Color, Egg Specific Gravity, And The Cuticle Of The Eggs Of Broiler Breeds, Byron Anthony Connor

Honors Theses

No abstract provided.


A Study On The Relationship Between Eggshell Color And Eggshell Quality In Commercial Broiler Breeders, Lawrence Hatten Iii Dec 1999

A Study On The Relationship Between Eggshell Color And Eggshell Quality In Commercial Broiler Breeders, Lawrence Hatten Iii

Honors Theses

No abstract provided.


Effect Of Calendaring On Flexographic Print Ability Of Linerboard, William P. Woods Dec 1999

Effect Of Calendaring On Flexographic Print Ability Of Linerboard, William P. Woods

Masters Theses

Today's corrugated board end user demands a higher quality than ever. Retailing techniques are moving toward so-called ''value-added packaging," which consists of high quality printed packaging that works to sell the product from the shelf. To preserve'its dominance in the corrugated market, the flexographic printing industry must find new ways to cost effectively satisfy the new demands.

One possibility is the use of an additional calendering step to give the linerboard better printability. This study evaluated two different types of calenders: the shoe (extended nip) calender and the hot/soft nip calender (Appendix A). The test material was commercially produced linerboard, …


Photoperiodic And Pineal Modification Of The Effect Of 6-Methoxybenzoxazolinone On Deciduoma Growth In Rats, Everett S. Nixon Dec 1999

Photoperiodic And Pineal Modification Of The Effect Of 6-Methoxybenzoxazolinone On Deciduoma Growth In Rats, Everett S. Nixon

Electronic Dissertations and Theses

The compound 6-methoxybenzoxazolinone (6-MBOA) is a nonestrogenic compound that enhances reproduction. Decidualization, marked by the decidual cell reaction, is a process that causes the transformation of the uterine stromal cells into decidual cells. The purpose of the study was to determine the reproductive role of 6-MBOA during decidualization in rats exposed to a short photoperiod (8L: 16D), and a long photoperiod (16L: 8D). Decidualization was induced by surgical uterine scratch trauma unto the anti-mesometrial surface of the uterine epithelium on day 4 of pseudopregnancy (PPG) a reproductive state that precedes and converges into decidualization. Rats were treated with subcutaneous doses …


Fundamental Study Of The Coating And Basesheet Influences On Gloss In Relationship To Coated Inkjet Papers, Raja Ramakrishnan Dec 1999

Fundamental Study Of The Coating And Basesheet Influences On Gloss In Relationship To Coated Inkjet Papers, Raja Ramakrishnan

Masters Theses

The use of fumed metallic oxides for glossy ink jet media offers alternatives to expensive cast coated and extruded film methods. Fumed metallic oxide pigments provide a high internal porosity and packing porosity that enable the rapid diffusion of liquid inks into the coating layer. Their small particle size (0.1-0.3μm), enable the development of gloss. However, calendering is needed to develop gloss values in the range of cast coated and extruded film grades.

Calendering of coated sheet reduces production speed, adds additional handling and rewinding cost (if performed off-line) and reduces the bulk and porosity of the coating layer, consequently …


Reciprocal Transplantation Of The Desert Soil Crust: Can It Be Done?, Christina D. Cole Dec 1999

Reciprocal Transplantation Of The Desert Soil Crust: Can It Be Done?, Christina D. Cole

UNLV Theses, Dissertations, Professional Papers, and Capstones

A 100 meter X 100 meter study site was chosen at White Rock Springs in Red Rock Canyon National Conservation Area, Nevada. To examine Syntrichia caninervis, a desert crustal moss, reciprocal transplantations (20 mm and 40 mm diameter cores) were performed between shaded to shaded, exposed to exposed, and shaded to exposed microsites to determine if it was possible to transplant the study organism with reasonable survivorship. Transplants were inspected following rain events for percent hydration, number of dead stems, and change in percent cover. Data indicated that there was a low mortality rate of S. caninervis stems, and few …


Survey Of Amphibians And Reptiles In Powhatan County, Virginia With Selected Natural History Notes, Jason Daniel Gibson Dec 1999

Survey Of Amphibians And Reptiles In Powhatan County, Virginia With Selected Natural History Notes, Jason Daniel Gibson

Theses & Honors Papers

This thesis establishes baseline data on the herpetofauna that exist in Powhatan county. No systematic study of the amphibians and reptiles in Powhatan county has ever been conducted. The methods used in this survey include hand capture, egg mass observations, road kill collections, and frog call surveys. Documentation of each species collected included measurements, photographs, range maps, and tape recordings.

This survey produced 8 species of salamanders, 11 anurans, 6 turtles, 4 lizards, and 14 snakes. Based on records in the Atlas of Amphibians and Reptiles of Virginia (Mitchell & Reay, 1999), 11 new county records were discovered. This brings …


Phylogeography Of The Night Lizard, Xantusia Henshawi, From Southern California, Robert Edward Lovich Dec 1999

Phylogeography Of The Night Lizard, Xantusia Henshawi, From Southern California, Robert Edward Lovich

Loma Linda University Electronic Theses, Dissertations & Projects

The granite night lizard, Xantusia henshawi, is a highly specialized crevice dwelling lizard found in the Peninsular Ranges of southern California, United States and northern Baja California, Mexico. Generally, little morphological variation is seen in this species over a variety of habitats throughout its range, from elevations near sea level to approximately 2000 meters, and from Mediterranean habitats near the Pacific coast to arid desert habitat in the Colorado Desert of California. One exception is the variation seen in the subspecies X h. gracilis, which differs from X h. henshawi in morphology, allozymes, ecology, and natural history.

In …


The Role Of Brn-3.2 In Retinal Ganglion Cell Differentiation, Jerin Marie Wright Dec 1999

The Role Of Brn-3.2 In Retinal Ganglion Cell Differentiation, Jerin Marie Wright

Loma Linda University Electronic Theses, Dissertations & Projects

Within the retina, the POU domain of transcription factors brn-3.0, brn-3.1, and brn-3.2 are present only in retinal ganglion cells. These genes are believed to be involved in establishing neural cell lineages in mammals. In this study brn-3.2 was examined by comparing the number of ganglion cells present during postnatal development in normal mice (+/+), in mice homozygous (-/-) for the brn-3.2 gene, and in adult mice with a heterozygous gene deletion (+/-) for brn-3.2. Optic nerve cross sections were imaged by electron microscopy, and axon profiles counted systematically by hand. These counts were then related to the nerve cross …


Use Of Randomly Amplified Polymorphic Dna-Polymerase Chain Reaction (Rapd-Pcr) To Distinguish North American Populations Of Acroptilon Repens (L.) Dc, Raul A. Ruiz Dec 1999

Use Of Randomly Amplified Polymorphic Dna-Polymerase Chain Reaction (Rapd-Pcr) To Distinguish North American Populations Of Acroptilon Repens (L.) Dc, Raul A. Ruiz

Theses and Dissertations - UTB/UTPA

Sixty U.S. populations of Acroptilon repens collected in 1998 were analyzed using RAPD-PCR. Each population was represented by five specimens gathered from each location. A total of 301 specimens were examined using two Operon Technologies, RAPD-PCR primers (A 10 and C04). The DNA amplification products produced through the PCR process were electrophoretically separated to produce DNA fragments ranging from 100 to 2000 base-pairs in length. The 60 U.S. populations sampled, produce ten RAPD banding pattern types using A 10 primer and seventeen pattern types with C04. Genetic variation within and among the populations was low, however, one dendogram did show …


Production Of The Subtropical Seagrass, Halodule Wrightii Aschers., In Lower Laguna Madre, Texas, Joseph L. Kowalski Dec 1999

Production Of The Subtropical Seagrass, Halodule Wrightii Aschers., In Lower Laguna Madre, Texas, Joseph L. Kowalski

Theses and Dissertations - UTB/UTPA

The autecology of shoal grass, Halodule wrightii Aschers., was studied at 1.2 m depth from June 1995 to February 1997 in Lower Laguna Madre (LLM), Texas. Halodule wrightii in LLM received about 47% surface irradiance, but otherwise displayed lower growth rates and biomass in nutrient-poor rhizosphere and water-column environments compared to H. wrightii populations in other Texas estuaries. High tissue N content and low C:N ratios belied low growth dynamics. Halodule wrightii in LLM is probably nutrient limited. A high nutrient demand by H. wrightii in a nutrient-poor environment may explain, in part, its gradual displacement by Thalassia testudinum and …


Effect Of Pollution On Genetic Diversity In The Southern California Bight, Xiao Li Ma Dec 1999

Effect Of Pollution On Genetic Diversity In The Southern California Bight, Xiao Li Ma

Loma Linda University Electronic Theses, Dissertations & Projects

Two intertidal invertebrate species, M galloprovincialis and Balanus glandula, were collected from seven different bay sites along the Southern California coast to test if environmental contamination is associated with the decrease of genetic diversity at the population level. Collections were made at three relatively pristine "clean" sites and four "impacted" sites which were exposed to heavy industrial or boating activity and which had previously, been identified as having measurable levels of pollution. The "Comet" assay (Single Cell Gel electrophoresis) was performed to measure single-strand DNA breaks in mussels at several of the sites in order to confirm differing impacts …


A Preclinical Model Of Ionizing Radiation And Tnf-Alpha Gene Therapy For Cancer, Jun Li Dec 1999

A Preclinical Model Of Ionizing Radiation And Tnf-Alpha Gene Therapy For Cancer, Jun Li

Loma Linda University Electronic Theses, Dissertations & Projects

Long term control of high-grade brain tumors is rarely achieved with current therapeutic regimens. This study sought to determine if pretreatment with plasmid DNA expressing Tumor Necrosis Factor-α (TNF-α) could enhance the effect of ionizing radiation in an aggressive, rapidly growing glioma tumor (C6) model. Plasmid DNA is an attractive vector system for delivery of foreign genes into eukaryotic cells due to its advantages including low immunogenicity in vivo, lesser toxicity and relatively low cost. We have constructed a plasmid-based mammalian expression vector (pGL1-TNF) to secrete human TNF-α from cancer cells. Plasmid DNA was successfully transfected into C6 cells …


Structural Studies Of Recombinant Human Β-Casein Proteins, Yilin Hu Dec 1999

Structural Studies Of Recombinant Human Β-Casein Proteins, Yilin Hu

Loma Linda University Electronic Theses, Dissertations & Projects

β-Casein is the major component (~80%) of the human casein system. Interacting with calcium and phosphates through its phosphorylated N-terminus, β-casein participates in the formation of micelles which carry these otherwise insoluble nutrients indispensable for the growth and development of newborns. Human β-casein, or fragments thereof, are also found to have biological effects such as enhancement of calcium absorption. So far, knowledge of micelle formation is limited and structural studies of β-casein, especially its N-terminal portion will provide a better understanding of the structure-function relationship of milk micelles.

To elucidate the role that the N-terminus of the protein plays in …


The Impact Of Resident And Transient Predators On The Popultation Dynamics Of Juvenile Caribbean Spiny Lobster (Panulirus Argus) In Florida Bay, Florida, Jason Edward Schratwieser Oct 1999

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

Biological Sciences Theses & Dissertations

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


A Study On The Effects Of The N-Terminal Amino Acid Sequence On The Activation Of Human T-Cell Leukemia Virus Type 1 Protease, Hidayah Muhammad Kendall Oct 1999

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

Chemistry & Biochemistry Theses & Dissertations

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

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


Gender Variation In Croton Californicus (Euphorbiaceae), James Lynwood Smith Ii Sep 1999

Gender Variation In Croton Californicus (Euphorbiaceae), James Lynwood Smith Ii

Loma Linda University Electronic Theses, Dissertations & Projects

Croton californicus Muell. Arg. (Euphorbiaceae) is a subshrub suspected of being dimorphic with phase choices. Gender variation in C. californicus was studied in natural populations of southern California for three years (1994-96) to observe patterns of gender !ability. Some sites exhibited significantly male-biased sex ratios, and these sites often had the greatest number of monoecious morphs, cosexual plants with unisexual flowers. Gender variation was quantified for cosexual plants by calculating the Estimated Floral Gender (EFG) which varied from 1.00 (female) to 0.00 (male). The distribution of the EFG was highly skewed towards maleness. Monoecious individuals were then categorized by …


Molecular Systematics & Evolution Of The Ctenosaura Hemilopha Complex (Squamata: Iguanidae), Michael Ray Cryder Sep 1999

Molecular Systematics & Evolution Of The Ctenosaura Hemilopha Complex (Squamata: Iguanidae), Michael Ray Cryder

Loma Linda University Electronic Theses, Dissertations & Projects

Molecular variation within Ctenosaura hemilopha and among other Ctenosaura species are used to identify species boundaries, assess suitable systematic characters, identify evolutionary patterns within C. hemilopha mitochondrial DNA sequences and reconstruct species and area relationships among the various taxa. The molecular evolution of the C. hemilopha complex is analyzed using 1109 base pairs of mitochondrial DNA sequence from the cytochrome b and cytochrome oxidase III genes. Samples come from 22 individuals representing each of the five allopatric populations.

The results of a parsimony analysis showed a strongly supported, partially resolved set of relationships. The strict consenses tee formed in this …


Regulation Of Connexin43 By Phosphorylation, Maithili M. Shah Sep 1999

Regulation Of Connexin43 By Phosphorylation, Maithili M. Shah

Loma Linda University Electronic Theses, Dissertations & Projects

Gap junctions play a crucial role in embryogenesis, especially of the heart where connexin43 is thought to be important for its formation as well as synchronized contraction. Several reports have shown that connexin43 protein is phosphorylated on serine residues in vitro and in vivo.

Studies performed in our laboratory have demonstrated that cell-to-cell communication in cells expressing connexin43 can be controlled rapidly and reversibly by microinjection of active protein kinases or phosphatases that target serine or threonine residues. Phosphorylation by cAMP-dependent protein kinase (PKA) seems to favor channel opening, whereas the effect of protein kinase C (PKC) on channel gating …


Neuronal And Metabolic Increases In Pedunculopontine Nucleus Of Parkinson's Rats, Jonathan Dennis Carlson Sep 1999

Neuronal And Metabolic Increases In Pedunculopontine Nucleus Of Parkinson's Rats, Jonathan Dennis Carlson

Loma Linda University Electronic Theses, Dissertations & Projects

The theoretical mechanisms underlying the symptoms of Parkinson’s disease are based on dysfunctional output from the basal ganglia projected to the cortex via the thalamus. However, the subthalamic nucleus (STN) and substantia nigra pars reticularis (SNr) as part of the basal ganglia, also project to the brainstem, in particular to the pedunculopontine nucleus (PPN). Both the STN and SNr have altered neuronal activity in the 6-hydroxydopamine (6-OHDA) Parkinson’s model rat. Thus, it is hypothesized that the PPN is altered in this model of Parkinson’s disease.

This hypothesis was examined by comparing the rates of glucose metabolism and spontaneous neuronal activity …


Development Of A Novel Method For Phenol Detection Using High Performance Thin Layer Chromatography, Danette Young Carlton Aug 1999

Development Of A Novel Method For Phenol Detection Using High Performance Thin Layer Chromatography, Danette Young Carlton

Theses & Honors Papers

The purpose of this study was to develop a more efficient method to test for phenol in both wastewater and non-wastewater. Phenol is a caustic and toxic contaminant that may be present in our water supplies. Phenol is used in various resins, pharmaceuticals, plastics and disinfectants. Environmental Protection Agency methods are available to test for phenol using gas chromatography along with mass spectrometry or flame ionization detection. Each of these methods can be a long, involved process consisting of extraction, many sample injections, and interference problems. This method developed an easier and less complicated approach of testing for phenol in …


Signaling Mechanisms For Muscarinic Receptor-Mediated Coronary Vasoconstriction In Isolated Rat Hearts, Yi Zhang Aug 1999

Signaling Mechanisms For Muscarinic Receptor-Mediated Coronary Vasoconstriction In Isolated Rat Hearts, Yi Zhang

Electronic Theses and Dissertations

The signaling mechanisms for muscarinic receptor-mediated vasoconstriction in coronary resistance arteries were studied in KCl-arrested isolated rat hearts perfused at a constant flow rate. The cholinergic agonists acetylcholine and bethanechol were given by bolus injection or constant infusion. The coronary vascular resistance was monitored by measuring the changes in perfusion pressure. The selective muscarinic agonist bethanechol caused a similar vasoconstrictor response as ACh, but with less potency and efficacy. Bolus injection of bethanechol evoked a phasic vasoconstriction in a dose-dependent manner, while infusion of bethanechol evoked a tonic vasoconstriction without producing tachyphylaxis. Coronary vascular responses to bethanechol were further examined …


Capture And On-Site Release Of Nuisance Black Bears And Survival Of Orphaned Black Bears Released In The Great Smoky Mountains, Jay Edwin Clark Aug 1999

Capture And On-Site Release Of Nuisance Black Bears And Survival Of Orphaned Black Bears Released In The Great Smoky Mountains, Jay Edwin Clark

Masters Theses

Since the establishment of Great Smoky Mountains National Park (GSMNP) in 1934, interactions between black bears (Ursus americanus) and visitors have been a regular occurrence. Prior to 1990, capture and relocation was the primary management alternative for nuisance bears in GSMNP. Since 1990, wildlife biologists in GSMNP have used capture and on-site release as an aversive conditioning technique for nuisance black bears. This technique involves capturing and immobilizing bears that frequent developed areas, collecting biological data, and releasing the bears back into the same area. The premise of this technique is to reinforce the natural fear of humans and thereby …


Maternal Employment And Dietary Quality Of Children Aged 42-60 Months, Lynn A. Samson Aug 1999

Maternal Employment And Dietary Quality Of Children Aged 42-60 Months, Lynn A. Samson

Masters Theses

(From the Summary): Abbreviated Maternal employment is becoming more the usual than an exception. Employment can be beneficial for mothers, providing satisfaction and increasing self-esteem. On the other hand, it can be stressful juggling between the roles of employee and mother. Other family members might help ease some of the burden, but mothers still bear most of the responsibility of child care and household responsibilities. Working mothers have less time to spend on food and nutrition. In most cases, the diets of children whose mothers are employed do not differ from children of mothers who are not employed, …


Universal Design And Nature Trails: Balancing Accessibility, Site Integrity, And The Recreation Experience, Steve Kirkindall Aug 1999

Universal Design And Nature Trails: Balancing Accessibility, Site Integrity, And The Recreation Experience, Steve Kirkindall

Electronic Theses and Dissertations

This study addressed the application of Americans With Disabilities Act (ADA) guidelines in outdoor recreation settings. The purpose was three-fold: to develop site- and user-friendly design principles for non-urban, accessible nature trails; to design and construct a trail based on those principles; and to evaluate both principles and trail by surveying trail users. The Delphi Method was employed with a national panel to assess current expert opinion regarding accessibility and trails. Fifty-nine principles were developed from combined results of panel deliberations and applied experience gained constructing a prototype trail utilizing the universal design concept. Trail users rated the importance of …


Effect Of Various Starch Sources On The Silicone Holdout Of Release Paper, Chandrasekaran Duraiswamy Aug 1999

Effect Of Various Starch Sources On The Silicone Holdout Of Release Paper, Chandrasekaran Duraiswamy

Masters Theses

Siliconized papers are widely being used from food and packaging industry to pressure sensitive label industry and their use has increased considerably over the last decade. Surface and structural properties of the sheet influence the silicone hold out and release properties.

Surface sizing of the sheet is done prior to silicone coating. The objective of this research is to find their film forming capabilities, fluid hold out of various starches, and the effect of the various calendering process on the release properties was also studied.

No significant difference between the starch sources were observed, except for the modified com starch …


Reactive Oxygen Species Generated By Depletion Of Cellular Glutathione Mediate Cadmium Cytotoxicity, Jun Xu Aug 1999

Reactive Oxygen Species Generated By Depletion Of Cellular Glutathione Mediate Cadmium Cytotoxicity, Jun Xu

Masters Theses

Studies were put forth to test whether or not reactive oxygen species, which are influenced by the cellular level of reduced glutathione, mediate the toxicity of cadmium. Cadmium has been a focal point in the health care community in the past few years because it has been shown to induce the development of tumors, interfere with cellular signaling, and cause damage to organs, tissues, and biomolecules. Although various studies and theories have been proposed, little direct evidence, especially from studies utilizing primary cells in culture, has accumulated to show the mechanism by which the cadmium induced toxicity occurs.

Our studies …


Role Of Mitogen-Activated Kinases In Cd40-Mediated T Cell Activation Of Monocyte/Macrophage And Vascular Smooth Muscle Cell Cytokine/Chemokine Production, Denise M. Milhorn Aug 1999

Role Of Mitogen-Activated Kinases In Cd40-Mediated T Cell Activation Of Monocyte/Macrophage And Vascular Smooth Muscle Cell Cytokine/Chemokine Production, Denise M. Milhorn

Electronic Theses and Dissertations

This dissertation represents efforts to determine the functional consequences acquired by vascular smooth muscle cells (SMC) in response to CD40 ligation by activated CD154+ T cells, and to elucidate components of the signaling pathway(s) activated in response to CD40 signaling in both monocytes and SMC. To study the consequences of CD40 stimulation, primary human monocytes and aortic SMC were treated with plasma membranes purified from CD154 + , CD4+ T cells. The results presented in this dissertation demonstrate that SMC, like monocytes/macrophages, are capable of interacting with T cells in a manner that results in reciprocal activation events. SMC were …


The Rise And Fall Of African American Midwifery In The South, Nicole M. Bernard Jul 1999

The Rise And Fall Of African American Midwifery In The South, Nicole M. Bernard

Electronic Dissertations and Theses

The purpose of this thesis is to give insight into the role played by the African American midwife in the rural south, including Louisiana, Alabama, Texas, and Florida. The African American midwife was responsible for prenatal care, delivery, and a certain degree of postnatal care for the mother and the infant. During slavery, she was all that the slaves had. The African American midwife also aided in delivery of some of the whites as well in a time when blacks were considered to be no more than animals. This proves that the African American midwife was more than a savage …