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Modern Invertebrate Footprints Compared With Fossil Footprints From The Coconino Sandstone (Permian), Marilyn A. Emtage

Loma Linda University Electronic Theses, Dissertations & Projects

Laboratory studies of trackways of the crayfish, Cambarus clarkii were conducted, and the footprints compared with fossil invertebrate footprints (Paleohelcura sp.) of the Permian Coconino sandstone of Northern Arizona, and similar footprints of other sandstone. Fine grained sand (similar to that composing the Coconino sandstone) was placed in a plexiglass tank to form slopes of various angles. The crayfish walked up and down slopes of 10°± 3°, 20°± 2°, 25° and on level sand, and their trackways were photographed. Trackways were produced on wet sand and underwater sand, but the animals would not walk on dry sand. Clear individual impressions …

Effect Of Radiation And Corynebacterium Parvum On The In Vivo Elimination Of Friend Virus-Induced Leukemia In C57bl/6 Mice, Betty A. Wu

Loma Linda University Electronic Theses, Dissertations & Projects

Administration of Corynebacterium parvum in combination with localized irradiation has been shown to be more efficient than radiation treatment alone in prolonging the survival time of methylethrane induced tumor in C3H mice. Fractionated low dose total body irradiation has been demonstrated to be a promising therapy for patients with chronic lymphocytic leukemia. The purpose of this study was to determine the effect of the combined treatment of total body irradiation and C. parvum on Friend virus induced leukemia in C57BL/6 mice. ^₁₂₅I-labeled FBL-3 cells were injected intraperitoneally into mice. Intraperitoneal injection of C. parvum and and single dose total …

The Effects Of Inducing Functional Class Iii Malocclusion On Actively Growing Rat Mandibles, Aarin Chu

Loma Linda University Electronic Theses, Dissertations & Projects

[Abstract Not Included]

The Effect Of Carbon Dioxide Concentration On Calcification In The Red Coralline Alga Bossiella Orbigniana, A. Dwight Smith

Loma Linda University Electronic Theses, Dissertations & Projects

The relationship between various experimental concentrations of CO2 and calcification was studied by measuring Ca-45 incorporation into the crystalline matrix. Air containing CO2 at partial pressures (Pc02) of 0.04% to 5.5% was bubbled through synthetic sea water in incubation vessels. The resultant pH values ranged from 8.7 to 6.5. The relative concentrations ofCO2, HCO3 , and CO2— 3 were calculated from the measured ' pH—PCO2 combinations. Calcification was correlated positively with HCO expressed as percent of total carbon. Maximum calcification of about one—third above normal occurred between 0.1% and 1.0% P CCOO22 At 0.26% P calcification increased as increments of …

Ultrasonic Versus Hand Filing Of The Human Root Canal System, Howard W. Scholz Jr.

Loma Linda University Electronic Theses, Dissertations & Projects

A comparison was made of ultrasonic filing versus hand filing using three solutions to flood the canals of 24 extracted human maxillary central incisors. A modified PR-30 Cavitron insert was used in a Cavitron 1010 unit for the ultrasonic filing. The clinical crown was removed with a diamond saw and water spray at the cemento-enamel junction. The two major groups were ultrasonic filing versus hand filing; the three subgroups were solution/solvents - 10% EDTA, 2.0% NaOCl, and distilled water.

After filing, the roots were grooved longitudinally with a high speed bur and cracked opened with a mallet and chisel. The …

An Analysis Of Species Recognition In Sympatric, Allopatric And Reciprocally Cross-Fostered Peromyscus Californicus And Peromyscus Eremicus (Rodentia, Cricetidae), Ronald L. Carter

Loma Linda University Electronic Theses, Dissertations & Projects

Experiments were performed to compare homospecific and heterospecific mate selection in two closely related species, Peromyscus californicus and Peromyscus eremicus. Comparisons were made between allopatric and sympatric populations and between males and females for mate selection performance. Both species made significant choice for the homospecific chambers. Significant homospecific choice was made by mice from sympatric populations, whereas allopatric populations did not demonstrate significant choice. No significant difference in choice performance was demonstrated between males and females even when the estrus stages of the females were controlled.

A comparison of different testing lengths and temporal regimes of data collection was performed …

The Effect Of Endodontic Therapy On The Incidence Of Radiation Caries In Dogs, James A. Abbott

Loma Linda University Electronic Theses, Dissertations & Projects

Endodontic therapy was evaluated as a possible control or prevention modality of radiation type dental caries in dogs. Two adult male dogs with permanent dentitions had endodontic therapy performed on alternating teeth in each jaw. The nontreated teeth served as controls.

The dogs were irradiated with 7000 rad Cobalt-60 radiation fractionated over an eight week period. The dogs were killed at 60 and 182 days post-irradiation. The teeth were removed from the jaws and immersed in methylene blue dye, sectioned, and the dye penetration pattern photographed. Diffusion of the dye into the tooth structure was quantified and statistically analyzed.

A …

Human Placental Alkaline Phosphatase And Steroid Metabolism By Rat Adrenals, Allen G. Meier

Loma Linda University Electronic Theses, Dissertations & Projects

Human placental alkaline phosphatase was purified by butanol extraction, methanol precipitation and chromatography on DEAE-cellulose. The pH optimum was found to be 10.9. The enzyme was competitively inhibited by di-ethyl-p-nitrobenzyl-phosphonate and copper sulfate. An increase in enzymatic activity occurred in the presence of the phosphate ion (HPO₄) and ATP.

The enzyme was crystallized from a 40% saturated solution of ammonium sulfate and shown to be homogeneous by sedimentation analysis. Homogeneity of the enzyme was also demonstrated using poly-acrylamide-gel-electrophoresis. At a pH of 7.5% the electrophoretic pattern yielded a single band and showed no significant contamination.

The metabolic transformation …

The Distribution Of Orcuttia Californica (Poaceae) In The Vernal Pools Of The Santa Rosa Plateau, Riverside County, California, Cluney M. Stagg

Loma Linda University Electronic Theses, Dissertations & Projects

Ecological studies were conducted on the rare annual grass Orcuttia californica (Vasey), an endemic to California, from April to September, 1976 in 11 vernal pools located on the Santa Rosa Plateau in Riverside County. To help determine why Orcutt grass occurs in only 6 of the 11 pools and more specifically why it only occurs in patches within a given pool, biweekly measurements of frequency, density and phenology were taken within each of a total of 28 circular plots (r = 10 meters) in 5 pools. This data was related to concurrent biweekly measurements of soil moisture, soil texture and …

An Investigation Of The Effects Of A Dietary Calcium And Vitamin D Supplement On The Resorption Of The Alveolar Ridge Of The Jaw In Immediate Denture Patients, Peter Brussee

Loma Linda University Electronic Theses, Dissertations & Projects

The purpose of this study was to investigate the possible effects of a calcium and vitamin D supplement on the resorption of alveolar bone following teeth extractions in human subjects. Studies have been cited which indicate a positive relationship between adequacy of calcium intake and maintenance of the bones of the jaw.

In this investigation, patients who received dentures immediately after the extraction of their remaining natural teeth were given a medication to take every day for a year.

Half the subjects received a calcium and vitamin D supplement while half received a placebo. As it was a double—blind study, …

A Study Of Dietary Calcium And Phosphorus Intakes In Relation To Residual Ridge Resorption, Rita L. Sørensen

Loma Linda University Electronic Theses, Dissertations & Projects

Resorption of alveolar bone, a characteristic observed in periodontal disease, in the totally edentulous mouth and in generalized osteoporosis, is a common world-wide phenomenon in man. Calcium deficiency and calcium-phosphorus imbalance are implicated as plausible factors in all three instances.

A compilation of recent investigations strongly suggests that oral bone loss, whether in periodontal disease or in the residual ridges, is an early manifestation of osteoporosis; and that osteoporosis, in general, is associated with disturbed calcium homeostasis.

This study, patterned after that of Wical and Swoope, was conducted on 55 subjects who had been totally edentulous for at least three …

Apical Closure Induction Using Bone Growth Factors And Mineral Trioxide Aggregate, Kenneth W. Tittle

Loma Linda University Electronic Theses, Dissertations & Projects

This study compared the ability of three different bone growth factor combinations with that of Ca(OH)₂ to stimulate apical closure as well as the effectiveness of Mineral Trioxide Aggregate (MTA) as an apical barrier. Fifty-six roots of second and fourth mandibular premolars of seven six- month old beagle dogs were used. Periradicular lesions were created over a four week period. The canals were cleaned and shaped and filled with Ca(OH)₂ for one week. They were then irrigated and received one of seven different treatments in a balanced design. Growth factors were placed in a carboxymethylcellulose carrier and delivered …