Design of Experiments and Sample Surveys Commons^™

Comparing The Use Of A Manual And A Power Toothbrush By 3-To-4 Year-Old Children, Lorena Delgado Salcedo

Loma Linda University Electronic Theses, Dissertations & Projects

PURPOSE: To compare the ability of three-to four-year-old children in performing toothbrushing with manual versus battery-powered toothbrushes with and without oral hygiene instructions.

METHODS: This study was a randomized, controlled, examiner-blind, 4-period crossover design performed on 50 healthy children, ages 3 to 4 years old. Children were assigned either a manual or power toothbrush at visit one and alternated between the two types of toothbrushes each week, for four weeks. Plaque was scored before and after brushing using the Greene and Vermillion -Simplified Oral Hygiene Index. ^18,19 At their last two visits of the study, the children received brushing instructions …

The Effect Of Calcium Hydroxide Pastes On Root Dentin Fracture Resistance, Kurt W. Sturz

Loma Linda University Electronic Theses, Dissertations & Projects

Calcium hydroxide is a common intracanal medicament used in the treatment of immature teeth that have been subjected to trauma or decay prior to root canal therapy. The effect of calcium hydroxide on immature root dentin is important. One area of concern is the effect that calcium hydroxide has on the fracture resistance of an immature tooth. It is the aim of this study to compare the effect of four different commercially available calcium hydroxide pastes on the fracture resistance of bovine teeth. Seventy-five freshly extracted, intact bovine incisors were prepared according to a modified Haapasalo and Orstavik technique. Each …

Acute Toxicity Testing Without Animals: More Scientific And Less Of A Gamble, Gillian R. Langley

Application of Alternative Methods Collection

In this report, we argue specifically that acute toxicity data should not be sought from animal tests. The underlying principle of such tests on rats and mice is that the results can be effectively extrapolated to humans. In fact, after nearly 80 years of use of these tests, the predictivity of rodent data for human acute toxic effects has been disputed but never proven.

Referent Selection Strategies In Case-Crossover Analyses Of Air Pollution Exposure Data: Implications For Bias, Holly Janes, Lianne Sheppard, Thomas Lumley

UW Biostatistics Working Paper Series

The case-crossover design has been widely used to study the association between short term air pollution exposure and the risk of an acute adverse health event. The design uses cases only, and, for each individual, compares exposure just prior to the event with exposure at other control, or “referent” times. By making within-subject comparisons, time invariant confounders are controlled by design. Even more important in the air pollution setting is that, by matching referents to the index time, time varying confounders can also be controlled by design. Yet, the referent selection strategy is important for reasons other than control of …

Psychological Factors Associated With Anticipatory Nausea And Vomiting, Melinda L. Nielsen

Loma Linda University Electronic Theses, Dissertations & Projects

Many cancer patients experience adverse chemotherapy-related side effects. The present study examined the relationships among disease variables (i.e. stage of cancer, type of breast cancer), medical treatment variables (i.e. toxicity of chemotherapy regimen, strength of antiemetic treatment), psychological variables (i.e. health locus of control, anxiety sensitivity, desire for control, coping strategies), and anticipatory nausea and vomiting in women with breast cancer. One hundred women with breast cancer completed the Multidimensional Health Locus of Control Scale - Form C, the Anxiety Sensitivity Index, the Krantz Health Opinion Survey, the Coping Inventory for Stressful Situations, and the Morrow Assessment of Nausea and …

Non-Parametric Estimation Of Roc Curves In The Absence Of A Gold Standard, Xiao-Hua Zhou, Pete Castelluccio, Chuan Zhou

UW Biostatistics Working Paper Series

In evaluation of diagnostic accuracy of tests, a gold standard on the disease status is required. However, in many complex diseases, it is impossible or unethical to obtain such the gold standard. If an imperfect standard is used as if it were a gold standard, the estimated accuracy of the tests would be biased. This type of bias is called imperfect gold standard bias. In this paper we develop a maximum likelihood (ML) method for estimating ROC curves and their areas of ordinal-scale tests in the absence of a gold standard. Our simulation study shows the proposed estimates for the …

Familial And Psychosocial Factors Affecting Adolescents' Academic Achievement, Isa Abdulnasir Ribadu

Loma Linda University Electronic Theses, Dissertations & Projects

This study examined the influence of family cohesion, family adaptability, self-image, and locus-of-control on two measures of academic achievement among male and female adolescents. Using a self-administered questionnaire, data were gathered from a convenient sample of 230 students from five high schools in San Bernardino County in southern California. The survey included the Offer Self-image Questionnaire, Family Adaptability and Cohesion Evaluation Scale III, the Nowick-Strickland Locus-of-Control Scale, academic achievement measures, and demographic measures that assessed individual and family characteristics. Family cohesion, family adaptability, self-image, and locus-of-control were significant predictors of both measures of academic achievement. Also, family cohesion and family …

The Association Of Blood Type On The Five Factors Of Personality In Chinese Adolescents, Kunher Wu

Loma Linda University Electronic Theses, Dissertations & Projects

The purpose of this study was to identify the number of personality factors in Chinese adolescents using the Chinese Revised NEO Personality Inventory (NEO-PI-R) and to determine whether blood type is associated with personality. It is widely accepted by psychologists that the five-factor model can provide an adequate representation of adult personality dimensions, but there is less agreement on the number of factors observable in adolescence. A total of 3,396 11^th graders from the city of Kaohsiung, Taiwan completed the Chinese NEO-PI-R. Principle component analysis with varimax rotation showed five factors of personality in these Taiwanese adolescents, which clearly …

Causal Inference In Hybrid Intervention Trials Involving Treatment Choice, Qi Long, Rod Little, Xihong Lin

The University of Michigan Department of Biostatistics Working Paper Series

Randomized allocation of treatments is a cornerstone of experimental design, but has drawbacks when a limited set of individuals are willing to be randomized, or the act of randomization undermines the success of the treatment. Choice-based experimental designs allow a subset of the participants to choose their treatments. We discuss here causal inferences for experimental designs where some participants are randomly allocated to treatments and others receive their treatment preference. This paper was motivated by the “Women Take Pride” (WTP) study (Janevic et al., 2001), a doubly randomized preference trail (DRPT) to assess behavioral interventions for women with heart disease. …

Overlap Bias In The Case-Crossover Design, With Application To Air Pollution Exposures, Holly Janes, Lianne Sheppard, Thomas Lumley

UW Biostatistics Working Paper Series

The case-crossover design uses cases only, and compares exposures just prior to the event times to exposures at comparable control, or “referent” times, in order to assess the effect of short-term exposure on the risk of a rare event. It has commonly been used to study the effect of air pollution on the risk of various adverse health events. Proper selection of referents is crucial, especially with air pollution exposures, which are shared, highly seasonal, and often have a long term time trend. Hence, careful referent selection is important to control for time-varying confounders, and in order to ensure that …

Clinical Effectiveness Of A Subperiosteal Anchorage Device, Monica Anne Witte

Loma Linda University Electronic Theses, Dissertations & Projects

The purpose of this pilot study was to evaluate the clinical efficacy of a subperiosteal anchorage device, the palatal OnPlant™, during orthodontic retraction of protruding anterior teeth in cases requiring maxillary premolar extraction. Seven subjects (5 female, 2 male), ages 13 to 55, were selected for the study. The OnPlant was surgically placed in the mid-palatal region through a well-defined subperiosteal tunnel. Following the manufacturer recommended osseointegration period of four months, the OnPlant was uncovered and attached to the first molars by means of a transpalatal bar. Standard orthodontic treatment then commenced to retract the anterior teeth after the first …

Peer Nutrition Education: A Model For Nutrition Education Among Spanish-Language Participants Of The Special Supplemental Nutrition Program For Women, Infants And Children (Wic), Maximino Alfredo Mejía

Loma Linda University Electronic Theses, Dissertations & Projects

Despite the steady improvement in the health status of Americans, Hispanics are a minority in the United States with greater prevalence of several infectious and chronic diseases and less health knowledge than the average citizen. Nearly half of the Hispanics living in this country die of preventable nutrition-related conditions, with heart disease and cancer being the leading causes. Since this minority has limited access to health care and preventive services, there is a need for an inexpensive, viable model of health education for this underserved segment of the population in order to lower the excess of preventable diseases. We trained …

Anatomy And Three-Dimensional Reconstructions Of The Brain Of A Bottlenose Dolphin (Tursiops Truncatus) From Magnetic Resonance Images, Lori Marino, Keith D. Sudheimer, Timothy L. Murphy, Kristina K. Davis, D. Ann Pabst, William A. Mclellan, James K. Rilling, John I. Johnson

Veterinary Science and Medicine Collection

Cetacean (dolphin, whale, and porpoise) brains are among the least studied mammalian brains because of the formidability of collecting and histologically preparing such relatively rare and large specimens. Magnetic resonance imaging offers a means of observing the internal structure of the brain when traditional histological procedures are not practical. Furthermore, internal structures can be analyzed in their precise anatomic positions, which is difficult to accomplish after the spatial distortions often accompanying histological processing. In this study, images of the brain of an adult bottlenose dolphin, Tursiops truncatus, were scanned in the coronal plane at 148 antero-posterior levels. From these scans …

The Differential Impact Of Sexism In Latino Men And Women’S Psychiatric Symptoms, Astrid Magalij Reina-Patton

Loma Linda University Electronic Theses, Dissertations & Projects

The study assessed the reliability of the Spanish and English versions of the Schedule of Sexist Events General Form (SSE-G). The extent to which Spanish and English-speaking men and women differed in their responses on the SSE-G was investigated, as was the degree to which men and women differed in their report of psychiatric symptoms. Further, the extent to which the SSE-G predicted psychiatric symptomology for Spanish and English-speaking men and women was assessed, as was the extent to which sexism (i.e., gender-specific stress) accounted for additional variance in symptoms, above and beyond that accounted for by acculturation, language, and …

Magnetic Resonance Imaging And Three-Dimensional Reconstructions Of The Brain Of A Fetal Common Dolphin, Delphinus Delphis, Lori Marino, Timothy L. Murphy, Lyad Gozal, John I. Johnson

Veterinary Science and Medicine Collection

To demonstrate the kinds of data that can be obtained non-destructively and non-invasively from preserved museum specimens using modern imaging technology the head region of a whole body fetal specimen of the common dolphin, Delphinus delphis, aged 8–9 months post-conception, was scanned using Magnetic Resonance Imaging (MRI). Series of scans were obtained in coronal, sagittal and horizontal planes. A digital three-dimensional reconstruction of the whole brain was prepared from the coronal series of scans. Sectional areas and three-dimensional volumes were obtained of the cerebral hemispheres and of the brainstemplus-cerebellum. Neuroanatomical features identified in the scans include the major sulci of …

Hand Intensive Leisure Activities And Repetitive Motion Injuries Of The Distal Upper Extremities, Marilyn Colvin Wright

Loma Linda University Electronic Theses, Dissertations & Projects

Background. The work-relatedness of repetitive motion injuries to the distal upper extremities (RMI-DUEs) has been well documented; however, human occupation extends beyond the job to include self-care and leisure activities. The effects of hand intensive leisure activities (HILAs) such as home computer use and needlework on RMI-DUEs have not been explored. These HILAs require hand usage similar to known work-related risk factors. Additionally, sedentary leisure contributes to obesity thereby increasing the disease burden of women. Health beliefs regarding leisure and fitness among women employed in hand intensive sedentary jobs have not been explored.

Purpose. The purpose of this study was …

Predicting Milk And Soft Drink Consumption Among Female Adolescents Using The Theory Of Planned Behavior, Nada Osman Kassem

Loma Linda University Electronic Theses, Dissertations & Projects

A total of 756 female adolescents, aged 13 to 18 years, from five public high schools in Antelope Valley Union High School District located in North Los Angeles County participated in this study between February 1999 and March 1999. The ethnic composition was 53.3% White/Anglo Americans, 19.3% Hispanics or Latinos and 10.2% Black/African Americans. The constructs of the Theory of Planned Behavior (attitude, subjective norm, and perceived behavioral control and their underlying beliefs) were assessed to determine the predictors of low-fat milk and regular soda consumption. A cross-sectional design with group-administered questionnaires was utilized.

Most participants (89.6%, n = 636) …

Assessing The Accuracy Of A New Diagnostic Test When A Gold Standard Does Not Exist, Todd A. Alonzo, Margaret S. Pepe

UW Biostatistics Working Paper Series

Often the accuracy of a new diagnostic test must be assessed when a perfect gold standard does not exist. Use of an imperfect test biases the accuracy estimates of the new test. This paper reviews existing approaches to this problem including discrepant resolution and latent class analysis. Deficiencies with these approaches are identified. A new approach is proposed that combines the results of several imperfect reference tests to define a better reference standard. We call this the composite reference standard (CRS). Using the CRS, accuracy can be assessed using multistage sampling designs. Maximum likelihood estimates of accuracy and expressions for …

A Cephalometric Study Of The Class Ii Correction Effects Of The Eureka Spring, Ernest L. Stromeyer

Loma Linda University Electronic Theses, Dissertations & Projects

The effect of the Eureka Spring appliance, was investigated on 37 consecutively treated, non compliant, bilateral Class II malocclusions, requiring at least 3 mm or more of additional molar correction. The mean pretreatment age of this sample was 13.9 years. All patients were treated by a single clinician utilizing the Eureka Spring. Lateral cephalographs were taken at start of orthodontic treatment (T1), at insertion of Eureka Springs (T2), and at removal of the Eureka Springs (T3). The average treatment interval between T2 and T3 was 4 months. Class II correction occurred almost entirely by dentoalveolar movement, 33% in the maxilla …

Methodological And Substantive Issues In Substance Abuse Prevention Research, C. Anderson Johnson, John W. Farquhar, Steve Sussman

CGU Faculty Publications and Research

This article summarizes current issues in drug abuse prevention research through integration of other articles in this journal and by heeding historical trends in prevention science. Recommendations are made for future research directions. For prevention to advance, iterative processes are needed involving both quasi-experimental and experimental designs and involving both small, simple units and large, complex, interactive units. Accuracy of measurement and replication are of paramount importance.

Sources Of Epidemiological Equivocacy, Timothy Sly

RISK: Health, Safety & Environment (1990-2002)

Mr. Sly discusses five sources of uncertainty and ambiguity in health and medical research that can interfere with decision making.

Space Closure Efficiency With Modified Ceramic Brackets : A Comparative Study, Kirk A. Specht

Loma Linda University Electronic Theses, Dissertations & Projects

The purpose of this study was to determine if the rate of extraction site closure was determined by the type of ceramic bracket used. A new ceramic bracket with a metal archwire slot was compared with a conventional ceramic bracket. Twenty patients were randomly assigned the metal slot ceramic bracket and conventional ceramic to one half of their maxillary arch respectively. The distribution was even left and right.

Retraction was started and completed on an 0.016" stainless steel round continuous archwire. One hundred gram sentalloy springs provided a uniform retraction force and were reactivated every four weeks to maintain a …

Measurement Of Blood Flow In Reflected Muco-Gingival Tissue Flaps In Cats : Using The Radiolabeled Microsphere Method, Gary T. Wuchenrich

Loma Linda University Electronic Theses, Dissertations & Projects

Blood flow to the maxilla and mandible may vary due to differences in vascular supply and in physiologic, metabolic and pathologic conditions. In general it is accepted that oral tissues have an abundant blood supply; however, there is little information quantifying blood flow to these regions. In this study, the maxillary tissues were chosen to measure the blood flow in attached and reflected gingival tissue in adult cats using the radiolabeled microsphere method.

Sixteen cats with permanent dentition, clean mouths, and without inflamed gingiva upon visual inspection were used and divided into two groups. Group 1 consisted of six cats …

Reproducibility Of Periodontal Probing, Su-Fang Wang

Loma Linda University Electronic Theses, Dissertations & Projects

This study evaluated reproducibility of periodontal probing by conventional manual and automated force-controlled electronic probes. A total of 1206 sites (6 sites per tooth including maxillary and mandibular incisor/canine, premolar, and molar sites) in 15 patients with history of moderate or advanced chronic periodontal disease were examined. Probings included probing pocket depths (PD), as well as probing attachment levels (PAL) from a reference stent. Measurements were recorded to the nearest 0.5 mm with both methods. Patients were examined twice, 7 to 10 days apart. At each visit, all sites were probed first with the conventional probe and then with the …

The Role Of T Cells In The Pathogenesis Of Periapical Lesions, John B. Wallstrom

Loma Linda University Electronic Theses, Dissertations & Projects

The pulps of mandibular molars of 15 athymic and 15 conventional rats were surgically exposed and left open to their oral flora. Each group was divided into 3 subgroups of 5 animals each. The rats were sacrificed after their pulps were exposed for 2, 4, or 8 weeks. After fixing, decalcifying, and embedding, the specimens were sectioned and stained with H and E. They were then examined under a microscopic grid and quantified by percentages of surface areas of bone, connective tissue, bone marrow, intrabony spaces, periapical lesions, and numbers of osteoclasts. This was done using a DataVoice computerized data …

The Fracture Strength Of Ceramic Brackets : An Update And Comparison, Christian P. Manley

Loma Linda University Electronic Theses, Dissertations & Projects

The purpose of this study was to compare the fracture strength of ceramic brackets which are currently on the market with ceramic brackets tested in a previous study at Loma Linda. Fracture strengths of standard edgewise ceramic brackets vs. pre-torqued ceramic brackets and bicuspid ceramic brackets vs. central incisor ceramic brackets were also compared.

A total of 160 Polycrystalline brackets, 8 categories in groups if 20, were tested for fracture strength. Each bracket was tested using the same testing model that was used in the previous study at Loma Linda. The brackets were tested by torquing a wire within the …

Anthropometric Parameters In Public School Students And Seventh-Day Adventist Vegetarian And Meat-Eating Students, Joan Sabaté-Casellas

Loma Linda University Electronic Theses, Dissertations & Projects

Concerns have been expressed for the ability of some vegetarian diets to support normal growth of children. Animal protein or meat intake showed a positive relationship to attained height in children from developing countries. In this study, the relationship between meat intake/vegetarian status and physical growth was investigated in children living in California.

Height and weight were collected on 2,272 Caucasian children aged 6-18 years attending Seventh-day Adventist (SDA) or public schools who participated in a two year longitudinal study. Age-, sex-, and school-specific mean heights and weights were at or above the national reference values. Sex-specific, age-adjusted regression analysis …

Case-Control Study Of Vitamin A Intake And Colorectal Cancer In Seventh-Day Adventists, John William Morgan

Loma Linda University Electronic Theses, Dissertations & Projects

Colorectal cancer is the second most common cause of cancer deaths in Americans; producing approximately 60,000 deaths in Americans each year. Studies of high and low risk populations have suggested a dietary etiology for colorectal cancer, although investigations of specific dietary factors have produced inconsistent results.

Population based studies of California Seventh-day Adventists demonstrate dietary variety regarding factors suspected as important in the etiology of colorectal cancer. These studies document a substantially reduced mortality and incidence from colorectal cancer in Seventh-day Adventists when compared to other California Populations. Although specific reasons for this difference remain obscure, the 'Unique lifestyle and …

Amount Of Root Shortening Related To Type Of Fixed Appliance : A Comparison Of The 0.018" And 0.022" Bracket Slot, Thomas L. Thompson

Loma Linda University Electronic Theses, Dissertations & Projects

The purpose of this study was to determine if a different incidence and severity of maxillary incisor apical root resorption occurs in cases treated with the 0.018 inch versus 0.022 inch slot in standard edgewise mechanics. A consecutively treated sample of 240 patients (98 boys and 142 girls), with a mean age of 13.4 years from the orthodontic clinic at Loma Linda University were studied. 120 of the cases were treated using 0.018" bracket slot with standard edgewise mechanics and 120 were treated using 0.022" non-torqued full banded standard edgewise mechanics. 60 of the cases in each of the above …

The Significance Of Alternative Techniques In Biomedical Research: An Analysis Of Nobel Prize Awards, Martin Stephens

Experimentation Collection

No abstract provided.